The American Journal of Sports Medicine

Football helmets used by high school athletes in the United States should meet the National Operating Committee on Standards for Athletic Equipment performance standards. Despite differences in interior padding and exterior shells, all football helmets should provide comparable protection against concussions. Yet, debate continues on whether differences in the rates or severity of concussions exist based on helmet age/recondition status, manufacturer, or model.

To investigate whether high school football concussion characteristics varied by helmet age/recondition status, manufacturer, and model.

Descriptive epidemiological study.

High school football concussion and helmet data were collected from academic years 2008-2009 through 2012-2013 as part of the National High School Sports-Related Injury Surveillance Study. The certified athletic trainers of participating schools submitted athlete-exposure (AE) and injury information weekly.

Participating schools reported 2900 football concussions during 3,528,790 AEs for an overall rate of 8.2 concussions per 10,000 AEs. Concussion rates significantly increased from 2008-2009 through 2012-2013 overall (P = .006) as well as in competition (P = .027) and practice (P = .023). Characteristics of concussed football players (ie, mean number of symptoms, specific concussion symptoms, symptom resolution time, and time until return to play) were similar among players wearing new helmets when compared with reconditioned helmets. Fewer players wearing an old/not reconditioned helmet had concussion symptoms resolve within 1 day compared with players wearing a new helmet. Despite differences in the manufacturers and models of helmets worn by all high school football players compared with players who sustained a concussion, the mean number of concussion symptoms, specific concussion symptoms, symptom resolution time, and time until return to play were similar for concussions sustained by football players wearing the most common helmet manufacturers and models.

Overall, for new and reconditioned football helmets, the most common helmet manufacturers and models on the market today appear to provide high school football players with similar protection against concussions.

Concussions can have serious acute and long-term effects. An understanding of concussion patterns in high school athletes can drive targeted preventive measures, including improvements to and/or better use of protective equipment, to reduce the incidence and/or severity of sports-related concussions.

In recent years, sports leagues and sports medicine experts have developed guidelines for concussion management. The extent to which current clinical practice is consistent with guideline recommendations is unclear. At the collegiate level, there have been few examinations of concussion management practices and the extent to which meaningful differences across divisions of competition exist.

The purposes of this study were to (1) examine current practices in concussion diagnosis and management at National Collegiate Athletic Association (NCAA) member colleges, (2) explore the extent to which current practices reflect current recommendations for concussion diagnosis and management, and (3) determine whether there are differences in management patterns across divisions of competition.

Descriptive epidemiology study.

An electronic questionnaire was sent to sports medicine clinicians at all NCAA member colleges during September and October 2013. Clinicians were asked about baseline assessments, diagnosis and management practices, return-to-play protocols, the perceived prevalence of underdiagnosis, and basic demographic information.

Approximately 30% (n = 866) of contacted clinicians, representing nearly 50% (n = 527) of NCAA member colleges, responded to the questionnaire. Preparticipation baseline examinations were administered at the majority of schools (95%), but most (87.5%) administered baseline assessments only to selected high-risk athletes. Computerized neurocognitive testing and balance assessments were most commonly used as preseason baseline and postinjury assessments. Multimodal examination in line with NCAA and other guidance was used only at a minority of institutions. Athletic trainers most commonly administered and interpreted the preseason baseline examination. Most clinicians reported that their institutions’ practices were in line with NCAA guidelines during the first 24 hours of an athlete’s concussion diagnosis, with exact percentages varying across measures. Differences across divisions of competition included shorter return-to-play time at Division I schools than Division III schools (9.13 vs 10.31 days, respectively) and more frequently referring concussed athletes to a physician within 24 hours of diagnosis at Division I schools.

Concussion management at many colleges in the United States incorporates elements recommended by current guidelines; however, there is room to improve. Increasing the use of a multimodal baseline and postinjury examination will elevate the concussion care provided to college athletes and better align with best practice guidance.

The Vestibular/Ocular Motor Screening (VOMS) is a newly developed screening tool that evaluates vestibular and ocular motor symptom (eg, headache, dizziness, nausea, fogginess) provocation after a sport-related concussion. Baseline data on the VOMS are needed to extend the application of this measure to broad age groups and to document normal variations in performance.

The primary purpose of this study was to examine the internal consistency of the VOMS in a large sample of healthy, nonconcussed collegiate athletes. The secondary purpose was to investigate the effects of patient sex and history of motion sickness, migraines, and concussions on baseline VOMS scores.

Cohort study; Level of evidence, 2.

A total of 263 National Collegiate Athletic Association Division I athletes (mean ± SD age, 19.85 ± 1.35 years) completed self-reported demographic and medical history at preseason physical examinations and baseline screening. Internal consistency of the VOMS was assessed with Cronbach α. A series of univariate nonparametric tests (χ² with odds ratios [ORs] and 95% CIs) were used to examine the associations among medical history risk factors and VOMS clinical cutoff scores (score of ≥2 for any individual VOMS symptom, near point of convergence [NPC] distance of ≥5 cm), with higher scores representing greater symptom provocation.

Internal consistency of the VOMS was high (Cronbach α = .97), and 89% of athletes scored below cutoff levels (ie, 11% false-positive rate). Female athletes (OR, 2.99 [95% CI, 1.34-6.70]; P = .006) and those with a personal history of motion sickness (OR, 7.73 [95% CI, 1.94-30.75]; P = .009) were more likely to have ≥1 VOMS scores above cutoff levels. No risk factors were associated with increased odds of an abnormal NPC distance.

The VOMS possesses internal consistency and an acceptable false-positive rate among healthy Division I collegiate student-athletes. Female sex and a history of motion sickness were risk factors for VOMS scores above clinical cutoff levels among healthy collegiate student-athletes. Results support a comprehensive baseline evaluation approach that includes an assessment of premorbid vestibular and oculomotor symptoms.

The Latarjet procedure for the treatment of recurrent anterior shoulder instability is highly successful, but reasons for failure are often unclear. Measurements of the “glenoid track” have not previously been evaluated as potential predictors of postoperative stability.

There are clinical and anatomic characteristics, including the glenoid track, that are predictive of outcomes after the Latarjet procedure.

Case series; Level of evidence, 4.

Patients who underwent the Latarjet procedure for anterior shoulder instability with glenoid bone loss before October 2012 were assessed for eligibility. Patient-reported subjective data that were prospectively collected and retrospectively reviewed included demographic information, patient satisfaction, pain measured on a visual analog scale (VAS), questions regarding instability, Single Assessment Numeric Evaluation (SANE) scores, American Shoulder and Elbow Surgeons (ASES) scores, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores, and Short Form–12 Physical Component Summary (SF-12 PCS) scores. Anatomic measurements were performed of the coracoid size (surface area and width), width of the conjoined tendon and subscapularis tendon, estimated glenoid defect surface area, Hill-Sachs interval (HSI), and projected postoperative glenoid track engagement. Failure was defined as the necessity for revision stabilization or continued instability (dislocation or subjective subluxation) at a minimum of 2 years postoperatively.

A total of 38 shoulders in 38 patients (33 men, 5 women) with a mean age of 26 years (range, 16-43 years) were included. The mean follow-up for 35 of 38 patients (92%) was 3.2 years (range, 2.0-7.9 years); 25 of 38 had undergone prior stabilization surgery, and 6 had workers’ compensation claims. All mean subjective outcome scores significantly improved (P < .05), with a high median satisfaction score of 9 of 10. Eight patients had failures because of continued instability. Patients with moderate or higher preoperative pain scores (VAS ≥3) had a negative correlation with postoperative SF-12 PCS scores (ρ = 0.474, P = .022). Patients with outside-and-engaged (Out-E) or “off-track” lesions were 4.0 times more likely to experience postoperative instability (relative risk, 4.0; 95% CI, 1.32-12.2; P = .33). The width of patients’ coracoid processes was also directly associated with postoperative stability (P = .014). Moreover, 50% (4/8) of failures demonstrated Out-E glenoid tracks (off-track lesions) versus 16% (4/25) of those without recurrent instability (P = .033). Five of 8 failures were considered as such because of subjective subluxation events, not frank dislocations. Four of the 6 patients with workers’ compensation claims had failed results (P = .016).

Workers’ compensation claims were associated with continued instability, and patients with higher preoperative pain levels demonstrated lower SF-12 PCS scores postoperatively. The concept of the glenoid track may be predictive of stability after the Latarjet procedure and may be helpful in surgical decision making regarding the treatment of Hill-Sachs lesions at risk for persistent engagement. Although stability and patient satisfaction are high after the Latarjet procedure, subjective complaints of subluxation may be more common than previously estimated.

Return to activity is a commonly used indication for shoulder hemiarthroplasty (HA) compared with total shoulder arthroplasty (TSA). Despite clinical studies demonstrating better functional outcomes after TSA, the literature has failed to show a difference in return to sports.

To compare rates of return to sports in a matched cohort of TSA and HA patients with a preoperative diagnosis of glenohumeral osteoarthritis (OA).

Cohort study; Level of evidence, 3.

A prospectively collected registry was queried retrospectively for consecutive patients who underwent HA. Inclusion criteria were preoperative diagnosis of OA and more than 2 years of follow-up. After meeting the inclusion criteria, all HA patients were statistically matched to a TSA patient. All patients had end-stage OA with significant glenohumeral joint space narrowing.

At final follow-up, 40 HA patients and 40 TSA patients were available. The average (±SD) age at surgery was 65.7 ± 10.5 years and 66.2 ± 9.6 years for the HA and TSA groups, respectively (P = .06). Average follow-up was 62.0 months and 61.1 months for the HA and TSA groups, respectively (P = .52). Average American Shoulder and Elbow Surgeons scores improved from 36.3 to 70.2 for HA patients and from 34.0 to 78.5 for TSA patients (P < .001 for both); final scores were not significantly different between groups (P = .21). Average visual analog scale pain scores improved from 6.3 to 2.2 for HA patients and from 6.1 to 0.6 for TSA patients (P < .001 for both). HA patients had significantly worse final visual analog scale scores compared with the TSA group (P = .002). Significantly more TSA patients were satisfied with their surgery compared with HA patients (100% vs 70%) (P = .01). Of both groups, 65.5% of HA patients (19 of 29) returned to at least 1 sport postoperatively compared with 97.3% of TSA patients (36 of 37) (P < .001). Average timing for return to full sports was 5.5 ± 4.2 months and 5.4 ± 3.1 months for the HA and TSA groups, respectively (P = .92). Significantly more TSA patients returned to higher upper extremity use sports (P = .01).

In patients with OA, rate of return to sports was significantly better after TSA compared with HA. HA patients had significantly more pain, worse surgical satisfaction, and decreased ability to return to high upper extremity use sports. For patients with OA who wish to return to sporting activities, these results help manage expectations.

Patients with irreparable rotator cuff tears have a defect of the superior capsule, which creates discontinuity of the shoulder capsule in the transverse direction (anterior-posterior direction). This effect is one of the causes underlying shoulder instability after rotator cuff tears.

The purpose of this study was to assess the effects of anterior and posterior continuity on shoulder biomechanics after superior capsule reconstruction (SCR). The hypothesis was that capsular continuity in the transverse direction would improve glenohumeral stability after SCR.

Controlled laboratory study.

Seven fresh-frozen cadaveric shoulders were tested by using a custom shoulder testing system. Subacromial peak contact pressure, glenohumeral superior translation, glenohumeral compression force, and glenohumeral range of motion (ROM) were compared among 5 conditions: (1) intact shoulder, (2) simulated irreparable supraspinatus tendon tear, (3) SCR without side-to-side suturing, (4) SCR with posterior side-to-side suturing, and (5) SCR with both anterior and posterior side-to-side suturing.

The creation of an irreparable supraspinatus tear significantly increased glenohumeral superior translation (0° of abduction: 254% of intact [P = .04]; 30° of abduction: 200% of intact [P = .04]) and subacromial peak contact pressure (0° of abduction: 302% of intact [P = .0001]; 30° of abduction: 239% of intact [P = .0006]), decreased glenohumeral compression force (0° of abduction: 85% of intact [P = .004]; 30° of abduction: 87% of intact [P = .0002]; 60° of abduction: 88% of intact [P = .0001]), and increased total ROM (0° of abduction: 16° increase [P = .008]). SCR without side-to-side suturing significantly decreased subacromial peak contact pressure (0° of abduction: 79% of intact [P = .0001]; 30° of abduction: 91% of intact [P = .001]; 60° of abduction: 55% of intact [P = .04]) but did not inhibit glenohumeral superior translation. By adding posterior side-to-side sutures, both glenohumeral superior translation (0° of abduction: 93% of intact [P = .02]; 30° of abduction: 110% of intact [P = .04]) and subacromial peak contact pressure decreased significantly (0° of abduction: 56% of intact [P = .0001]; 30° of abduction: 83% of intact [P = .0003]; 60° of abduction: 46% of intact [P = .04]). Neither SCR with nor SCR without side-to-side suturing ameliorated the tear-associated decrease in glenohumeral compression force and increase in total ROM. Adding anterior side-to-side sutures did not change any measurements compared with SCR with posterior side-to-side suturing.

SCR with side-to-side suturing completely restored the superior stability of the shoulder joint by establishing posterior continuity between the graft, residual infraspinatus tendon, and underlying shoulder capsule.

Side-to-side suturing between the graft, residual infraspinatus tendon, and underlying shoulder capsule is recommended for SCR in patients with irreparable supraspinatus tendon tears to restore superior stability after surgery.

With rising participation in youth sports such as baseball, proximal humeral epiphysiolysis, or Little League shoulder (LLS), is being seen with increasing frequency. However, there remains a paucity of literature regarding the causes, natural history, or treatment outcomes of LLS.

To analyze the demographic, clinical, and diagnostic features of a population of LLS patients, with an emphasis on identifying underlying risk factors for the development and recurrence of LLS after nonoperative treatment.

Case series; Level of evidence, 4.

A departmental database at a high-volume regional children’s hospital was queried to identify cases of LLS between 1999 and 2013. Medical records were reviewed to allow for analysis of age, sex, athletic information, physical examination and radiologic findings, treatment details, clinical course, and rates of recurrence.

Ninety-five patients (93 males, 2 females; mean age, 13.1 years; range, 8-16 years) were diagnosed with LLS. The number of diagnosed cases increased annually over the study period. All patients had shoulder pain with overhead athletics; secondary symptoms included elbow pain in 13%, shoulder fatigue or weakness in 10%, and mechanical symptoms in 8%. While the majority of patients (97%) were baseball players (86% pitchers, 8% catchers, 7% other positions), a small subset (3%) were tennis players. On physical examination, 30% were reported to have glenohumeral internal rotation deficit (GIRD), defined as a decreased arc of rotational range of motion of the shoulder. Treatment recommendations included rest in 99% of cases, physical therapy in 79% (including 100% of patients with GIRD), and position change upon return to play in 26%. Average time to full resolution of symptoms was 2.6 months, while average time to return to competition was 4.2 months. Recurrent symptoms were reported in 7% of the overall cohort at a mean of 7.6 months after initial diagnosis. The odds of recurrence in the group with diagnosed GIRD (14%) were 3.6 times greater than those without GIRD (5%; 95% CI: 0.7-17.1), but this difference was not statistically significant (P = .11).

Little League shoulder is being diagnosed with increasing frequency. While most common in male baseball pitchers, the condition can occur in females, youth catchers, other baseball positions players, and tennis players. Concomitant elbow pain may be seen in up to 13%. After rest and physical therapy, recurrent symptoms may occur in a small subset of patients (7%), generally 3 to 6 months after return to sports. Almost one-third of LLS patients had GIRD, and this group had approximately three times higher probability of recurrence compared with those without GIRD.

Minimalist running shoes (MRS) are lightweight, are extremely flexible, and have little to no cushioning. It has been thought that MRS will enhance running performance and decrease injury risk.

To compare physical characteristics, fitness performance, and injury risks associated with soldiers wearing MRS and those wearing traditional running shoes (TRS).

Case series; Level of evidence, 4.

Participants were men in a United States Army brigade (N = 1332). Physical characteristics and Army Physical Fitness Test data were obtained by survey. Fitness performance testing was administered at the brigade, and the types of footwear worn were identified by visual inspection. Shoe types were categorized into 2 groups: TRS (stability, cushioning, and motion control) and MRS. Injuries from the previous 12 months were obtained from the Defense Medical Surveillance System. A t test was used to determine mean differences between personal characteristics, training, and fitness performance metrics by shoe type. Hazard ratios and 95% CIs were calculated to determine injury risk by shoe type, controlling for other risk factors.

A majority of soldiers wore cushioning shoes (57%), followed by stability shoes (24%), MRS (17%), and motion control shoes (2%). Soldiers wearing MRS were slightly younger than those wearing TRS (P < .01); performed more push-ups, sit-ups, and pull-ups (P < .01); and ran faster during the 2-mile run (P = .01). When other risk factors were controlled, there was no difference in injury risk for running shoe type between soldiers wearing MRS compared with TRS.

Soldiers who chose to wear MRS were younger and had higher physical performance scores compared with soldiers wearing TRS. When these differences are controlled, use of MRS does not appear to be associated with higher or lower injury risk in this population.

Although knee injuries in professional soccer (football) have been extensively studied, the prevalence of knee osteoarthritis (OA) in veteran players is not well documented.

To investigate the prevalence of knee OA in retired professional soccer players in comparison with a group of athletically active military personnel.

Cross-sectional study; Level of evidence, 3.

A group of 100 veteran Greek soccer players aged 35 to 55 years (mean [±SD] age, 46.90 ± 5.9 years) were examined for knee OA and were administered the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire. A matched group of 100 athletically active military personnel served as a comparison group.

The sonographic prevalence of OA was significantly higher in the veteran soccer group (52%) than in the military group (33%) (n = 200; P = .010). This difference remained significant even after excluding participants with a history of knee surgery (44.1% vs 25.3%, respectively) (n = 151; P = .010). Femoral cartilage thickness was similar between the 2 groups (P = .473), while altered knee alignment had no effect on the prevalence of OA (P = .740). With the exception of perceived pain being more prevalent in the military group, there were no other statistically significant differences between the 2 groups in KOOS values.

Veteran soccer players had a higher sonographic prevalence of knee OA but better pain scores than a matched group of athletically active military personnel.

The incidence rates (IRs) and factors associated with injuries in the sport of Paralympic athletics (track and field) have not been comprehensively and prospectively studied.

To determine injury IRs, characteristics of injuries, and associated factors in the sport of athletics at the London 2012 Paralympic Games.

Cohort study; Level of evidence, 2.

A total of 977 athletes competing in the sport of athletics were followed over a total 10-day competition period of the Paralympic Games. Daily injury data were obtained via 2 databases: (1) a custom-built, web-based injury and illness surveillance system (WEB-IISS), maintained by team medical personnel; and (2) the organizing committee database, maintained by medical providers in the medical stations operated by the London Organising Committee of the Olympic and Paralympic Games. Athlete impairment and event discipline were obtained via the International Paralympic Committee athlete database. IRs (injuries per 1000 athlete-days) by impairment, event discipline, sex, and age were examined.

The overall IR was 22.1 injuries per 1000 athlete-days (95% CI, 19.5-24.7). In track disciplines, ambulant athletes with cerebral palsy experienced a lower incidence of injuries (IR, 10.2; 95% CI, 4.2-16.2) when compared with ambulant athletes from other impairment categories. Athletes in seated throwing experienced a higher incidence of injuries (IR, 23.7; 95% CI, 17.5-30.0) when compared with athletes in wheelchair racing (IR, 10.6; 95% CI, 5.5-15.6). In both track and field disciplines, the majority of injuries did not result in time loss from competition or training. Ambulant athletes experienced the greatest proportion of injuries to the thigh (16.4% of all injuries; IR, 4.0), observed predominantly in track athletes. Wheelchair or seated athletes experienced the greatest proportion of injuries to the shoulder/clavicle (19.3% of all injuries; IR, 3.4), observed predominantly in field athletes.

This is the first prospective cohort study examining injury IRs and associated factors in the sport of athletics at the Paralympic Games. Injury patterns were specific to the event discipline and athlete impairment. The majority of injuries occurred to the thigh (ambulant athletes) or shoulder/clavicle (wheelchair or seated athletes) and did not result in time loss.

Track and field is one of the most popular high school sports among boys and girls, but epidemiological research on the sport and its individual events has been limited.

To describe injury rates and patterns in boys’ and girls’ high school track and field.

Descriptive epidemiology study.

A retrospective epidemiological analysis of injury and exposure data from a longitudinal national high school sports injury surveillance system was conducted.

From 2008-2009 through 2013-2014, 2485 track and field injuries occurred during 2,962,308 athlete exposures (0.84 injuries per 1000 athlete exposures). Injury rates were higher in competition versus practice for both sexes. Girls had higher injury rates than boys overall (rate ratio, 1.37; 95% CI, 1.27-1.48) and in practice (rate ratio, 1.60; 95% CI, 1.46-1.76), but competition injury rates did not differ. Overuse/chronic injuries accounted for 27.5% and 36.2% of boys’ and girls’ track and field injuries, respectively. The majority of injuries were to the lower extremity. Sprints, distance running, and jumps accounted for over 65% of all track injuries. Boys sustained a greater proportion of injuries in relay events (injury proportion ratio, 2.02; 95% CI, 1.69-2.36) but fewer in hurdle events (injury proportion ratio, 0.51; 95% CI, 0.23-0.78).

Injury rates varied by event, sex, and competition versus practice exposure. To increase effectiveness, targeted strategies for injury prevention should be driven by an understanding of such differences. Because many track and field injuries are overuse/chronic across sexes and for both competitions and practices, coaches and athletic trainers should be adept at recognizing early injury symptoms, intervene to treat minor injuries in order to prevent severe injuries, and ensure the prompt diagnosis and management of all injuries.

The prevalence of sport specialization in high school athletes is unknown. This information is needed to determine the scope of this issue in an active population.

To determine the prevalence of sport specialization in high school athletes and to determine if specialization is influenced by classification method, year in school, sex, and school size. A secondary purpose was to determine if highly specialized athletes would be more likely to report a history of lower extremity injuries.

Cross-sectional study; Level of evidence, 3.

High school athletes between the ages of 13 and 18 years from 2 local high schools completed both a sport specialization survey and an injury history survey. Athletes were classified into low, moderate, or high specialization groups using a recently developed 3-point system and were also classified using a self-classification method.

A total of 302 athletes completed the surveys and were classified as low specialization (n = 105, 34.8%), moderate specialization (n = 87, 28.8%), or high specialization (n = 110, 36.4%). Athletes from the small school were more likely to be classified in the low specialization group (low, 43%; moderate, 32%; high, 25%) compared with those from the large school (low, 26%; moderate, 26%; high, 48%) (P < .001). Athletes in the high specialization group were more likely to report a history of overuse knee injuries (n = 18) compared with moderate (n = 8) or low specialization (n = 7) athletes (P = .048). Athletes who trained in one sport for more than 8 months out of the year were more likely to report a history of knee injuries (odds ratio [OR], 2.32; 95% CI, 1.22-4.44; P = .009), overuse knee injuries (OR, 2.93; 95% CI, 1.16-7.36; P = .018), and hip injuries (OR, 2.74; 95% CI, 1.09-6.86; P = .026). Using the self-classification method, more participants self-classified as multisport (n = 213, 70.5%) than single sport (n = 89, 29.5%). Athletes from the small school were more likely to classify themselves as multisport (n = 128, 86%) (P < .001) than those from the large school (n = 85, 56%). There were no differences in the history of hip, knee, or ankle injuries between athletes who self-classified as single sport (hip: n = 10, 3%; knee: n = 19, 6%; ankle: n = 35, 12%) versus those who self-classified as multisport (hip: n = 45, 8%; knee: n = 23, 15%; ankle: n = 98, 33%) (P > .370).

Classification method and school size influenced the prevalence of specialization in high school athletes. Highly specialized athletes were more likely to report a history of overuse knee or hip injuries. Participating in a single sport for more than 8 months per year appeared to be an important factor in the increased injury risk observed in highly specialized athletes.

Hamstring autografts for anterior cruciate ligament (ACL) reconstruction (ACLR) have become popular in the past 2 decades; however, it is difficult to predict the diameter of the harvested tendons before surgery. Previous biomechanical studies have suggested that a smaller graft diameter leads to a lower load to failure, but clinical studies looking at various predictors for failure, including graft size, have been inconclusive.

To evaluate the relationship of hamstring graft diameter to ACL revision within a large cohort of patients, while controlling for sex, age, body mass index (BMI), and femoral and tibial fixation type.

Case-control study; Level of evidence, 3.

A case-control study using patients registered in an ACLR registry was conducted. Revision was used as a marker for graft failure. A case was defined as a patient who underwent primary ACLR with a hamstring autograft that was revised during the study period (April 2006 to September 2012). Three controls, defined as patients who underwent primary ACLR with a hamstring autograft that was not revised, were matched to each of the cases according to age, sex, BMI, and femoral and tibial fixation type. Descriptive characteristics were employed, and conditional logistic regression was conducted to produce estimates of odds ratios and 95% CIs.

A total of 124 cases and 367 controls were identified. There were no significant differences between cases and controls in the distribution of sex (52.4% male vs 52.9% male, respectively; P = .932), median age (17.6 years [interquartile range (IQR), 15.9-20.4] vs 17.6 years [IQR, 15.9-20.4], respectively; P = .999), median BMI (23.4 kg/m² [IQR, 21.5-26.4] vs 23.4 kg/m² [IQR, 21.6-25.8], respectively; P = .954), femoral fixation (P = .459), and tibial fixation (P = .766). The mean (±SD) graft diameter was 7.9 ± 0.75 mm in the cases and 8.1 ± 0.73 mm in the controls. The likelihood of a patient needing revision ACLR in the study cohort was 0.82 times lower (95% CI, 0.68-0.98) for every 0.5-mm increase in the graft diameter from 7.0 to 9.0 mm.

In this study, within the range of 7.0 to 9.0 mm, there was a 0.82 times lower likelihood of being a revision case with every 0.5-mm incremental increase in graft diameter.

Soft tissue grafts are commonly used in surgical reconstruction of the anterior cruciate ligament (ACL). Applying the appropriate tension to the final graft reconstruction has traditionally been performed by the surgeon and is based on the surgeon’s experience and perception of applied tension. Problems with manual application of tension to the ACL reconstruction include under- or overtightening the reconstruction, inconsistent tension application among subjects, and variable load application to each strand.

To assess whether measured tensioning of hamstring ACL grafts during fixation improves clinical outcome or knee laxity postoperatively when compared with conventional tensioning maneuvers.

Randomized controlled trial; Level of evidence, 1.

This was a prospective randomized controlled trial of consecutive primary ACL patients. The device group included patients in whom a measured tensioning device was used for graft tensioning (80 N), and the physician group did not use a tensioning device. The primary outcome was KT-1000 arthrometer side-to-side laxity differences between knees at 6, 12, and 18 months postoperatively. Secondary outcomes included the International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form and Anterior Cruciate Ligament Quality of Life Questionnaire (ACL-QoL) at those intervals. Chi-square and t tests were used for analysis. The study had 90% power to detect a difference of 2 mm between groups.

A sample of 127 patients was randomized. Of those, 14 did not have follow-up data and were excluded from this analysis, resulting in a final sample of 113 (55 patients in the device group and 58 in the physician group). No significant differences were found in baseline demographics or comorbidities. There were no significant differences between the groups (physician vs device) at baseline and at 6, 12, and 18 months in side-to-side laxity (4.6 vs 4.7 mm, 1.6 vs 1.3 mm, 1.5 vs 1.3 mm, and 1.1 vs 1.0 mm, respectively), IKDC score (58.2 vs 56.4, 72.0 vs 67.9, 79.9 vs 76.0, and 81.3 vs 78.5, respectively), or ACL-QoL score (998.2 vs 901.2, 1846.4 vs 1647.5, 2150.4 vs 2268.3, and 2436.9 vs 2231.8, respectively).

Measured tensioning of hamstring ACL grafts during fixation does not improve clinical outcome or knee laxity postoperatively when compared with conventional tensioning maneuvers.

There is a need for successful screening methods to identify athletes at increased risk of anterior cruciate ligament (ACL) injury. Previous research showed that collegiate athletes with ACL tears demonstrated slower time to stabilization during jump landing after reconstruction.

Collegiate athletes with baseline deficiencies in time to stabilization are at increased risk of subsequent ACL rupture.

Case-control study; Level of evidence, 3.

A total of 278 National Collegiate Athletic Association Division I college athletes (166 men, 112 women; mean age, 18.5 years; height, 178.8 cm; mass, 79.9 kg) in the high-risk sports of men’s football; women’s volleyball and field hockey; and men’s and women’s lacrosse, basketball, and soccer were measured to obtain baseline time to stabilization for backward, forward, medial, and lateral single-legged jump landing tasks. Athletes were followed for ACL rupture over a 4-year period. Independent t tests were used to evaluate differences in time to stabilization for each jump landing task between athletes with subsequent ACL rupture and uninjured athletes. Logistic regression models were used to assess time to stabilization as a predictor for ACL rupture.

Nine athletes sustained noncontact ACL ruptures (5 men, 4 women). These 9 athletes took significantly longer to stabilize compared with uninjured athletes during baseline backward jump landing (1.58 ± 0.39 and 1.09 ± 0.52 seconds, respectively; P = .0052). The odds of ACL rupture increased 3-fold (odds ratio, 2.95; 95% CI, 1.28-6.77) for every second increase in backward time to stabilization observed between injured and uninjured athletes.

Collegiate athletes with slower baseline backward time to stabilization were at increased risk of ACL rupture.

Multivariate analysis that identifies the combination of risk factors associated with anterior cruciate ligament (ACL) trauma is important because it provides insight into whether a variable has a direct causal effect on risk or an indirect effect that is mediated by other variables. It can also reveal risk factors that might not be evident in univariate analyses; if a variable’s effect is moderated by other variables, its association with risk may be apparent only after adjustment for the other variables. Most important, multivariate analyses can identify combinations of risk factors that are more predictive of risk than individual risk factors.

A diverse combination of risk factors predispose athletes to first-time noncontact ACL injury, and these relationships are different for male and female athletes.

Case-control study; Level of evidence, 3.

Athletes competing in organized sports at the high school and college levels participated in this study. Data from injured subjects (109 suffering an ACL injury) and matched controls (227 subjects) from the same athletic team were analyzed with multivariate conditional logistic regression to examine the effects of combinations of variables (demographic characteristics, joint laxity, lower extremity alignment, strength, and personality traits) on the risk of suffering their first ACL injury and to construct risk models.

For male athletes, increases in anterior-posterior displacement of the tibia relative to the femur (knee laxity), posterior knee stiffness, navicular drop, and a decrease in standing quadriceps angle were jointly predictive of suffering an ACL injury. For female athletes the combined effects of having a parent who had suffered an ACL injury and increases in anterior-posterior knee laxity and body mass index were predictive of ACL injury.

Multivariate models provided more information about ACL injury risk than individual risk factors. Both male and female risk models included increased anterior-posterior knee laxity as a predictor of ACL injury but were otherwise dissimilar.

The incidence of isolated anterior cruciate ligament (ACL) tears in the general population is not well defined.

The purpose of this study was to define the population-based incidence of ACL tears, describe trends in ACL injuries over time, and evaluate changes in the rate of surgical management. The hypothesis was that the incidence of ACL injury and the rate of subsequent ACL reconstruction increase over time.

Cohort study; Level of evidence, 3.

The study population included 1841 individuals who were diagnosed with new-onset, isolated ACL tears (without concomitant ligament injury that required surgery) between January 1, 1990, and December 31, 2010. The complete medical records were reviewed to confirm diagnosis and to extract injury and treatment details. Age- and sex-specific incidence rates were calculated and adjusted to the 2010 US population. Poisson regression analyses were performed to examine incidence trends by age, sex, and calendar period.

The overall age- and sex-adjusted annual incidence of ACL tears was 68.6 per 100,000 person-years. Incidence was significantly higher in male patients than in females (81.7 vs 55.3 per 100,000, P < .001). The incidence of isolated ACL tears decreased significantly over time in males (P < .001) but remained relatively stable in females. Age-specific patterns differed in male and female patients, with a peak in incidence (241.0 per 100,000) between 19 and 25 years in males and a peak in incidence (227.6 per 100,000) between 14 and 18 years in females. The rate of ACL reconstruction increased significantly over time in all age groups (P < .001).

With an annual incidence of 68.6 per 100,000 person-years, isolated ACL tears remain a common orthopaedic injury. Differences in age-specific incidence trends in male and female patients may potentially reflect differences in sports participation patterns through the high school and college years. The significant increase in the rate of ACL reconstruction over time may reflect changing surgical indications or an increasing desire among patients to return to high levels of activity after ACL injury.

Anatomic features of the tibial plateau (ie, posterior slope and medial concavity) have been associated with an increased risk of anterior cruciate ligament (ACL) injuries. However, it remains unclear whether these findings translate to ACL injuries sustained during recreational alpine skiing.

To investigate the association in recreational alpine skiers between prominent morphological features of the tibial plateau (slope and concavity) and the risk of sustaining an ACL injury during a noncontact incident.

Case-control study; Level of evidence, 3.

Magnetic resonance imaging data of 121 recreational alpine skiers (74 female, 47 male) after a noncontact knee injury were used for this study. Of these patients, 80 (71% female [n = 57]) had a complete unilateral ACL tear (rupture group), and 41 (41% female [n = 17]) had no indications of an ACL injury (intact group). Two blinded independent examiners measured the slopes of the tibial plateau in the sagittal and coronal planes along with the maximum depth of the medial tibial plateau. Measurements were compared between sexes and between groups using t tests. Logistic regression was used to assess the associations between quantified anatomic indices and the risk of ACL injuries.

Within 121 study patients, female skiers had greater odds of an ACL tear compared with male skiers (odds ratio, 3.5; 95% CI, 1.6-7.8; P < .001). Female skiers were more likely to have a greater lateral tibial slope (LTS) (P = .02) and medial tibial slope (MTS) (P = .02) with a shallower medial tibial depth (MTD) (P = .02) compared with male skiers. No differences between sexes were observed in the coronal tibial slope (CTS) (P = .97). Male and female skiers as a combined group showed no associations between quantified anatomic indices and the risk of sustaining an ACL tear (P > .10). Likewise, no significant differences were observed between the intact versus rupture group in any of the quantified anatomic indices (P > .10). Similar findings were observed when the analyses were repeated on male and female skiers separately.

Despite differences between sexes in knee anatomy and the injury risk, the sagittal and coronal slopes (LTS, MTS, CTS), as well as the concavity of the medial tibial plateau (MTD), were not associated with the risk of an ACL tear during a noncontact injury among recreational alpine skiers.

Trochlear dysplasia is a well-described risk factor for patellofemoral instability. Despite its clear association with the incidence of patellar instability, it is unclear whether the presence of high-grade trochlear dysplasia influences clinical outcome after patellofemoral stabilization.

To determine whether isolated proximal soft tissue stabilization for patellofemoral instability is as successful in patients with high-grade dysplasia compared with low-grade or no dysplasia, as measured by disease-specific quality-of-life and pain scores.

Case series; Level of evidence, 4.

A total of 277 patellofemoral stabilization procedures were performed during the study period. An isolated stabilization was performed in 233 patients, and 203 of these patients (87%) had adequate lateral radiographs and complete Banff Patella Instability Instrument (BPII) scores available for assessment. Of these, 152 patients underwent a medial patellofemoral ligament reconstruction (MPFL-R) and 51 patients received a medial patellofemoral ligament imbrication (MPFL-I). There were 21 patients with no trochlear dysplasia, 89 patients with low-grade dysplasia (Dejour type A), and 93 patients with high-grade dysplasia (Dejour types B-D). An independent-samples t test was used to determine the difference between the pre- and postoperative BPII scores. A Spearman rho correlation was calculated between 3 trochlear dysplasia groups and the BPII scores at a mean 24 months after patellofemoral stabilization. An independent-samples t test was used to assess the influence of trochlear bump size on outcomes by stratifying data and assessing for a relationship to BPII scores.

The independent-samples t test demonstrated statistically significant improvements in pre- to postoperative BPII scores for both groups. The MPFL-R group improved from a mean BPII score of 24.36 to 65.16 (P < .001), and the MPFL-I group improved from a mean of 28.92 to 73.45 (P < .01). For the MPFL-R patient cohort, the Spearman rho correlation demonstrated a significant relationship between postoperative BPII scores and presence of a trochlear bump and degree of dysplasia (P ≤ .05). Overall, a trochlear bump of ≥5 mm was associated with lower postoperative BPII scores (t₍₁₉₃₎ = 2.65, η² = 0.04).

This research has established a statistically significant correlation between trochlear dysplasia and disease-specific outcomes after MPFL-R surgery. Overall, there was evidence of significant improvement in disease-specific quality-of-life scores after patellofemoral stabilization surgery. This study is the largest cohort reported to date and therefore adds substantially to the evidence that trochlear dysplasia is a significant risk factor for and predictor of outcome among patients with patellofemoral instability.

Anterior cruciate ligament (ACL) rupture is a well-known risk factor for development of knee osteoarthritis. Early identification of those patients at risk and early identification of the process of ACL rupture leading to osteoarthritis may aid in preventing the onset or progression of osteoarthritis.

To identify early degenerative changes as assessed on magnetic resonance imaging (MRI) after 2-year follow-up in patients with a recent ACL rupture and to evaluate which determinants are related to these changes.

Cohort study; Level of evidence, 2.

Included in this study were 154 adults aged between 18 and 45 years with acute ACL rupture diagnosed by physical examination and MRI, without previous knee trauma or surgery, and without osteoarthritic changes on radiographs. A total of 143 patients completed the 2-year follow-up, and the results in this study apply to these 143 patients. All patients were treated according to the Dutch guideline on ACL injury. Of the 143 patients, 50 patients were treated nonoperatively during the 2-year follow-up period. Main outcome was early degenerative changes assessed on MRI defined as progression of cartilage defects and osteophytes in tibiofemoral and patellofemoral compartments. Patient characteristics, activity level, functional instability, treatment type, and trauma-related variables were evaluated as determinants.

The median time between MRI at baseline and MRI at 2-year follow-up was 25.9 months (interquartile range, 24.7-26.9 months). Progression of cartilage defects in the medial and lateral tibiofemoral compartments was present in 12% and 27% of patients, and progression of osteophytes in tibiofemoral and patellofemoral compartments was present in 10% and 8% of patients, respectively. The following determinants were positively significantly associated with early degenerative changes: male sex (odds ratio [OR], 4.43; 95% CI, 1.43-13.66; P = .010), cartilage defect in the medial tibiofemoral compartment at baseline (OR, 3.66; 95% CI, 1.04-12.95; P = .044), presence of bone marrow lesions in the medial tibiofemoral compartment 1 year after trauma (OR, 5.19; 95% CI, 1.56-17.25; P = .007), joint effusion 1 year after trauma (OR, 4.19; 95% CI, 1.05-16.72; P = .042), and presence of meniscal tears (OR, 6.37; 95% CI, 1.94-20.88; P = .002). When the patients were categorized into 3 treatment groups (nonoperative, reconstruction <6 months after ACL rupture, and reconstruction ≥6 months after ACL rupture), there was no significant relationship between the treatment options and the development of early degenerative changes.

Two years after ACL rupture, early degenerative changes were assessed on MRI. Concomitant medial cartilage defect and meniscal injury, male sex, persistent bone marrow lesions in the medial tibiofemoral compartment, and joint effusion are risk factors for degenerative changes.

A flipped, or inverted, meniscus segment is easily visualized in the normal meniscus. However, an inverted discoid meniscus segment may be difficult to appreciate because the tear occurs more centrally and leaves more meniscal rim; thus, it may be undertreated if not addressed during arthroscopy.

To describe findings on clinical history, radiographs, MRI, and arthroscopy of a lateral discoid meniscus with an inverted segment and compare them with characteristics of a lateral discoid meniscus without an inverted segment.

Case-control study; Level of evidence, 3.

Between 2009 and 2012, a retrospective series of 121 consecutive knee arthroscopies for symptomatic lateral discoid meniscus were reviewed for the presence of an inverted fragment. Chart review of clinical presentation, operative reports, radiographic images, and arthroscopic images was performed. Comparative analysis of the clinical presentation between lateral discoid menisci with an inverted segment and noninverted lateral discoid menisci was performed by use of Fisher exact test and Mann-Whitney test.

Nineteen patients with an inverted discoid meniscus segment (14 males, 5 females; average age, 15.0 years; range, 9.5-17.0 years) were compared with 102 patients with a noninverted discoid meniscus (53 males, 49 females; average age, 12.3 years; range, 5-17.0 years) (P = .011 for sex and P < .001 for age). All 19 discoid meniscus patients with an inverted segment had activity-related knee pain. Only 4 patients (21.0%) reported mechanical symptoms. Patients with an inverted discoid segment, compared with patients with discoid menisci without inverted segments, were more likely to have instability and effusion (P = .012 and P < .001, respectively). Eighteen discoid meniscus patients with an inverted segment (94.7%) had an injury, while only 41.2% of patients with noninverted symptomatic discoid menisci had an injury (P < .001). On MRI, an inverted discoid segment was seen as a horizontal longitudinal tear, a free fragment, or a double meniscus. During arthroscopy, the inverted discoid segment appeared normal, without a tear; upon probing, however, the inverted segment could be exposed.

An inverted discoid segment occurs during adolescence, and it is more likely to occur in male patients and more likely to be associated with activity-related pain and injury compared with a noninverted symptomatic discoid meniscus. A discoid meniscus with an inverted segment does not have the standard radiographic and arthroscopic features normally associated with a discoid meniscus.

The incidence of anterior cruciate ligament (ACL) injuries may be decreased through the use of intervention programs that focus on increasing the knee flexion angle during jump landing, which decreases strain on the ACL.

To investigate whether intervention training designed to change the knee flexion angle during landing causes secondary changes in other known measures associated with the risk of ACL injuries and to examine the time points when these secondary measures change.

Controlled laboratory study.

A total of 39 healthy recreational athletes performed a volleyball block jump task in an instrumented gait laboratory. The participants first completed the jumps without any modification to their normal landing technique. They were then given oral instruction to land softly and to increase their knee flexion angle during landing. Lower body kinematics and kinetics were measured before and after the modification using an optoelectronic motion capture system.

The knee flexion angle after the modification significantly increased from 11.2° to 15.2° at initial contact and from 67.8° to 100.7° at maximum flexion, and the time between initial contact and maximum flexion increased from 177.4 to 399.4 milliseconds. The flexion modification produced a substantial reduction in vertical ground-reaction force (243.1 to 187.8 %BW) with a concomitant reduction in the maximum flexion moment. Interestingly, the flexion modification only affected the abduction angle and abduction moment for the group of participants that landed in an initial adducted position before the modification and had no significant effect on the group that landed in an abducted position.

Increasing the knee flexion angle during jump landing may be an effective intervention to improve knee biomechanical risk factors associated with an ACL injury. However, the fact that the flexion modification only influenced critical risk factors (the abduction angle and abduction moment) in participants who initially landed in an adducted position suggests that the selection of interventions to prevent ACL injuries should account for patient-specific characteristics.

The study helps elucidate how increasing the knee flexion angle affects lower body biomechanics and provided evidence for the need to introduce patient-specific strategies for preventing ACL injuries.

Because of ongoing problems with anterior cruciate ligament (ACL) reconstruction, new approaches in the treatment of ACL injuries, particularly strategies based on tissue engineering, have gained increasing research interest. To allow for ACL regeneration, a structured scaffold that provides a mechanical basis, has cells from different sources, and comprises mechanical as well as biological factors is needed. Biological materials, biodegradable polymers, and composite materials are being used and tested as scaffolds. The optimal scaffold for ACL regeneration should be biocompatible and biodegradable to allow tissue ingrowth but also needs to have the right mechanical properties to provide immediate mechanical stability.

The study hypotheses were that (1) a novel degradable silk fiber–based scaffold with mechanical properties similar to the native ACL will be able to initiate ligament regeneration after ACL resection and reconstruction under in vivo conditions and (2) additional cell seeding of the scaffold with autologous stromal vascular fraction–containing adipose-derived stem cells will increase regenerative activity.

Controlled laboratory study.

A total of 33 mountain sheep underwent ACL resection and randomization to 2 experimental groups: (1) ACL reconstruction with a scaffold alone and (2) ACL reconstruction with a cell-seeded scaffold. Histological evaluation of the intra-articular portion of the reconstructed/regenerated ligament was performed after 6 and 12 months.

After 6 months, connective tissue surrounded the silk scaffold with ingrowth in some areas. The cell-seeded scaffolds had a significant lower silk content compared with the unseeded scaffolds and demonstrated a higher content of newly formed tissue. After 12 months, the density of the silk fibers decreased significantly, and the ingrowth of newly formed tissue increased in both groups. No differences between the 2 groups regarding silk fiber degradation and regenerated tissue were detected at 12 months.

The novel silk fiber–based scaffold was able to stimulate ACL regeneration under in vivo conditions. Additional cell seeding led to increased tissue regeneration and decreased silk fiber content at 6 months, whereas these differences were not present at 12 months.

ACL regeneration using a silk fiber–based scaffold with and without additional cell seeding may provide a new treatment option after joint injuries.

Among patients treated nonoperatively for 1 year after anterior cruciate ligament (ACL) disruption, little is known about the frequency of ACL reconstruction within the first year of injury and the effect of age range, sex, and meniscal tears on the incidence of ACL reconstruction between 1 and 10 years after injury.

To (1) define the rate of delayed ACL reconstruction (between 1 and 10 years after injury) in a population-based cohort of isolated ACL tears and (2) evaluate predictive factors associated with delayed reconstruction.

Case-control study; Level of evidence, 3.

The study included a population-based cohort of 1841 patients with new-onset, isolated ACL tears that occurred between January 1, 1990, and December 31, 2010. The complete medical records were reviewed to confirm diagnosis and collect data on clinical characteristics and details of subsequent ACL surgery. To evaluate the incidence of ACL reconstruction between 1 and 10 years after injury, landmark survival analysis was performed with a landmark set at 1 year after injury. Early and late predictors of ACL reconstruction were analyzed using Cox proportional hazards regression.

A total of 661 patients were treated nonoperatively for the first year after ACL tears. Over a mean 10 years of follow-up, 213 patients (32%) underwent ACL reconstruction between 1 and 10 years after injury. Young age (hazard ratio [HR], 0.55 per decade increase in age; 95% CI, 0.48-0.62) and meniscal tear at injury (HR, 1.48; 95% CI, 1.12-1.95) were significant predictors of undergoing delayed reconstruction. The rate of delayed ACL reconstruction decreased significantly over the study period (P < .03). There was no association between sex (HR, 0.89; 95% CI, 0.67-1.16) and delayed ACL reconstruction. Among patients who had delayed ACL reconstruction, 40% experienced a secondary meniscal tear before surgery.

In this study population of 1841 patients, 62% of patients received ACL reconstruction within 1 year of injury. Of patients treated nonoperatively for 1 year after ACL tears, 32% underwent delayed ACL reconstruction. Predictors of reconstruction beyond 1 year were young age (50% reduction in reconstruction per decade increased age) and baseline meniscal tear. Sex was not predictive for reconstruction beyond 1 year from injury.

Previous research has noted sex-based differences in anterior cruciate ligament (ACL) injury rates in young athletes, while little is known about medial collateral ligament (MCL) and meniscal injury rates in this population. The objective of this study was to compare injury rates for traumatic knee injuries (ie, ACL, MCL, and meniscal injuries) in collegiate and high school (HS) varsity student-athletes across multiple sports.

Knee injury rates vary by sex and across different sports and levels of competition.

Descriptive epidemiology study.

Injury and athlete-exposure data were utilized from the National Athletic Treatment, Injury and Outcomes Network (NATION) and National Collegiate Athletic Association (NCAA) Injury Surveillance Program (ISP) during the 2009-2010 to 2013-2014 academic years. Analyses focused on ACL, MCL, and meniscal injuries. Injury rates and injury rate ratios (IRRs) with 95% CIs were calculated for basketball, ice hockey, lacrosse, soccer, and baseball/softball.

The ACL injury rate was higher for female than male athletes at the collegiate (IRR, 2.49; 95% CI, 1.81-3.41) and HS (IRR, 2.30; 95% CI, 1.67-3.18) levels. At the collegiate level, the highest ACL IRR comparing female to male athletes was reported in softball/baseball (IRR, 6.61; 95% CI, 1.48-29.55). At the HS level, the highest ACL IRR was reported in basketball (IRR, 3.68; 95% CI, 1.91-7.10). The MCL injury rate was higher for female than male athletes at the HS level (IRR, 2.11; 95% CI, 1.25-3.56) but lower for female than male athletes at the collegiate level (IRR, 0.73; 95% CI, 0.59-0.92). The meniscal injury rate was lower for female than male athletes at the HS level (IRR, 0.47; 95% CI, 0.31-0.71), while no differences by sex were seen at the collegiate level (IRR, 1.35; 95% CI, 0.90-2.02).

Knee injury rates varied by sex across 5 different sports in the HS and collegiate settings. Female athletes sustained ACL injuries at a higher rate than male athletes at both the HS and collegiate levels in these 5 sports; however, there was not a distinct sex disparity in MCL and meniscal injuries. Future studies should examine the rates of concomitant and recurrent injuries to inform injury prevention and rehabilitation programs.

The Bernese periacetabular osteotomy (PAO) is an effective surgical treatment option for symptomatic acetabular dysplasia. Little evidence exists regarding the results of PAO and rates of return to play (RTP) in an athletic population.

The majority of athletes will demonstrate improvements in functional outcome measures, such as the modified Harris Hip Score and Hip Disability and Osteoarthritis Outcome Score, and will be able to return to sports after PAO.

Case series; Level of evidence, 4.

A comprehensive surgical hip database at an academic referral center was used to identify a subpopulation of athletes on whom PAO was performed. Data analyzed included preceding surgeries, reoperations, and RTP timing and features. Standard pre- and postoperative radiologic parameters and validated functional outcome measures were assessed, and a regression model assessed risk factors for prolonged time to RTP.

Of 245 PAOs performed over the 5-year study period, 46 were performed in 41 patients who met inclusion criteria for being an athlete (mean age, 26.2 years; range, 13-41 years; 36 females; 19% of all PAOs), representing a variety of sports. Prior surgery had been performed on 9 hips (20%). Only 1 post-PAO procedure (2%), excision of heterotopic ossification, was performed during the study period. At final follow-up (median, 3.1 years; range, 1.2-4.4 years), significant mean improvements were observed in modified Harris Hip Score (from 71 to 90; P < .001) and Hip Disability and Osteoarthritis Outcome Score (from 64 to 89; P < .001). The University of California–Los Angeles Activity Scale scores were maintained at a high level (range, 8.0-8.2; P = .28). RTP was reported in 80% of patients (37 of 46) at a median of 9 months postoperatively, with increased postoperative pain as the only independent predictor of longer time to RTP. Of these 37 athletes, 27 (73%) returned to the same level, although this was significantly less common (P = .06) in competitive athletes (11 of 19; 58%) than in recreational athletes (16 of 18; 89%). Among those who did return at the same level, 23 of 27 (85%) were able to maintain this level over time, but this was not significantly different between competitive (8 of 11; 73%) and recreational (15 of 16; 94%) athletes (P = .27).

Most athletic patients undergoing PAO are female patients and show postoperative improvements in function and return to athletic play. However, although there was no decline in overall activity level at a mean of 3 years, self-assessed athletic performance was attained and maintained in approximately one-half of the study population.

Bony morphological abnormalities of the hip joint are often accompanied by adaptive soft tissue changes. These adaptive changes, if better understood and characterized, may serve to inform clinical decision making.

To investigate the correlation between the size of the hip labrum and lateral acetabular coverage in patients at our hip preservation clinic.

Cross-sectional study; Level of evidence, 3.

A cohort of 236 patients seen at a dedicated hip preservation service between June 2013 and June 2015 were retrospectively analyzed. Patients were grouped according to the degree of acetabular coverage, as measured by the lateral center-edge angle (LCEA): normal acetabular coverage (25°-39.9°), acetabular overcoverage (≥40°), borderline dysplasia (20°-24.9°), and frank dysplasia (<20°). Preoperative magnetic resonance imaging was utilized to measure the length of the labrum at 3 locations: laterally, anteriorly, and anteroinferiorly.

Frankly dysplastic and borderline dysplastic hips exhibited larger values of labral length at all locations when compared with hips with normal acetabular coverage (P < .001) or acetabular overcoverage (P < .001). Interestingly, mean labral length values in frank dysplasia were statistically similar to corresponding measurements in borderline dysplasia. In hips with frank dysplasia, borderline dysplasia, or normal acetabular coverage, labral length was consistently greatest at the lateral labrum and correspondingly lowest at the anteroinferior labrum (P < .001). In hips with acetabular overcoverage, labral length did not vary significantly between the lateral, anterior, and anteroinferior locations. Multivariate analyses confirmed LCEA to be the strongest predictor of labral length, irrespective of measurement location.

Patients with borderline dysplasia and frank dysplasia exhibited increased values of labral length in the weightbearing zone, potentially indicating a compensatory reaction to the lack of bony coverage. Labral length may serve as an instability marker and inform clinical decision making for patients with borderline dysplasia.

Anterior midtibial stress fractures are an important clinical problem for patients engaged in high-intensity military activities or athletic training activities. When nonoperative treatment has failed, intramedullary (IM) nail and plate fixation are 2 surgical options used to arrest the progression of a fatigue fracture and allow bone healing.

A plate will be more effective than an IM nail in preventing the opening of a simulated anterior midtibial stress fracture from tibial bending.

Controlled laboratory study.

Fresh-frozen human tibias were loaded by applying a pure bending moment in the sagittal plane. Thin transverse saw cuts, 50% and 75% of the depth of the anterior tibial cortex, were created at the midtibia to simulate a fatigue fracture. An extensometer spanning the defect was used to measure the fracture opening displacement (FOD) before and after the application of IM nail and plate fixation constructs. IM nails were tested without locking screws, with a proximal screw only, and with proximal and distal screws. Plates were tested with unlocked bicortical screws (standard compression plate) and locked bicortical screws; both plate constructs were tested with the plate edge placed 1 mm from the anterior tibial crest (anterior location) and 5 mm posterior to the crest.

For the 75% saw cut depth, the mean FOD values for all IM nail constructs were 13% to 17% less than those for the saw cut alone; the use of locking screws had no significant effect on the FOD. The mean FOD values for all plate constructs were significantly less than those for all IM nail constructs. The mean FOD values for all plates were 28% to 46% less than those for the saw cut alone. Anterior plate placement significantly decreased mean FOD values for both compression and locked plate constructs, but the mean percentage reductions for locked and unlocked plates were not significantly different from each other for either plate placement. The percentage FOD reductions for all plate constructs and the unlocked IM nail were significantly less with a 50% saw cut depth.

Plate fixation was superior to IM nail fixation in limiting the opening of a simulated midtibial stress fracture, and anterior-posterior placement of the plate was an important variable for this construct.

Results from these tests can help guide the selection of fixation hardware for patients requiring surgical treatment for a midtibial stress fracture.

Osteochondral injuries have poor endogenous healing potential, and no standard treatment has been established. The use of combined layered autologous bone and cartilage chips for treatment of osteochondral defects has shown promising short-term clinical results.

This study aimed to investigate the role of cartilage chips by comparing combined layered autologous bone and cartilage chips with autologous bone implantation alone in a Göttingen minipig model. The hypothesis was that the presence of cartilage chips would improve the quality of the repair tissue.

Controlled laboratory study.

Twelve Göttingen minipigs received 2 osteochondral defects in each knee. The defects were randomized to autologous bone graft (ABG) combined with autologous cartilage chips (autologous dual-tissue transplantation [ADTT]) or ABG alone. Six animals were euthanized at 6 months and 6 animals were euthanized at 12 months. Follow-up evaluation consisted of histomorphometry, immunohistochemistry, semiquantitative scoring (International Cartilage Repair Society II), and computed tomography.

There was significantly more hyaline cartilage in the ADTT group (25.8%) compared with the ABG group (12.8%) at 6 months after treatment. At 12 months, the fraction of hyaline cartilage in the ABG group had significantly decreased to 4.8%, whereas the fraction of hyaline cartilage in the ADTT group was unchanged (20.1%). At 6 and 12 months, there was significantly more fibrocartilage in the ADTT group (44% and 60.8%) compared with the ABG group (24.5% and 41%). The fraction of fibrous tissue was significantly lower in the ADTT group compared with the ABG group at both 6 and 12 months. The implanted cartilage chips stained >75% positive for collagen type 4 and laminin at both 6 and 12 months. Significant differences were found in a number of International Cartilage Repair Society II subcategories. The volume of the remaining bone defect significantly decreased from 6 to 12 months in both treatment groups; however, no difference in volume was found between the groups at either 6 or 12 months.

The presence of cartilage chips in an osteochondral defect facilitated the formation of fibrocartilage as opposed to fibrous tissue at both 6 and 12 months posttreatment. The implanted chips were present in the defect and viable after 12 months.

This study substantiates the chondrogenic role of cartilage chips in osteochondral defects.

There are a variety of reported surgical techniques outcomes of chronic grade III posterolateral corner (PLC) knee injuries. It is unknown if outcomes differ among the various surgical treatments.

To systematically review the literature and report subjective and objective outcomes for surgical treatment strategies for chronic grade III PLC injuries to determine the optimal surgical technique.

Systematic review; Level of evidence, 4.

A systematic review of the literature including Cochrane, PubMed, Medline, and Embase was performed. The following search terms were used: posterolateral corner knee, posterolateral knee, posterolateral instability, multiligament knee, and knee dislocation. Inclusion criteria were outcome studies of surgical treatment for chronic PLC knee injuries with a minimum 2-year follow-up, subjective outcomes, objective outcomes including varus stability, and subgroup data on PLC injuries. Two investigators independently reviewed all abstracts. Accepted definitions of varus stability on examination or stress radiographs, and the need for revision surgery, were used to categorically define success and failure.

Fifteen studies with a total of 456 patients were included in this study. The 15 studies included 5 with level 3 evidence and 10 with level 4 evidence. The mean age of the patients in each study ranged from 25.2 to 40 years, the reported mean time to surgery ranged from 5.5 to 52.8 months, and the mean follow-up duration ranged from 2 to 16.3 years. Mean postoperative Lysholm scores ranged from 65.5 to 91.8; mean postoperative International Knee Documentation Committee (IKDC) scores ranged from 62.6 to 86.0. Based on objective stability, there was an overall success rate of 90% and a 10% failure rate of PLC reconstruction. A variety of surgical techniques were reported.

Chronic PLC injuries were reconstructed in all studies, and while techniques varied, the surgical management of chronic PLC injuries had a 90% success rate and a 10% failure rate according to the individual investigators’ examination or stress radiographic assessment of objective outcomes. More than half of the 456 patients had a combined posterior cruciate ligament–PLC injury. Surgical techniques included variations of fibular slings, capsular shifts, and anatomic-based techniques (fibular tunnel and tibial tunnel). Further research is needed to determine the optimal surgical technique for treating chronic grade III PLC injuries.