The American Journal of Sports Medicine

Although cam-type femoroacetabular impingement is commonly associated with labral chondral damage and hip pain, a large proportion of asymptomatic individuals will have this deformity.

To determine the incidence of hip pain in a prospective cohort of volunteers who had undergone magnetic resonance imaging (MRI) of their hips.

Case control study; Level of evidence, 3.

A total of 200 asymptomatic volunteers who underwent an MRI of both hips were followed for a mean time of 4.4 years (range, 4.01-4.95 years). Thirty were lost to follow-up, leaving 170 individuals (77 males, 93 females) with a mean age of 29.5 years (range, 25.7-54.5 years). All patients were blinded to the results of their MRI. All completed a follow-up questionnaire inquiring about the presence of hip pain or a history of hip pain lasting longer than 6 weeks since the original MRI. Each patient was asked to draw where the pain was on a body diagram.

Eleven patients (5 males, 6 females; 6.5% of sample; mean age, 29.9 years; range, 25.7-45.6 years) reported hip pain, of which 3 (1 male, 2 females) had bilateral pain for a total of 14 hips. Seven of the 14 painful hips had a cam-type deformity at the time of the initial MRI versus 37 of the 318 nonpainful hips (P = .0002). This gave a relative risk of 4.3 (95% confidence interval [CI], 2.3-7.8) of developing hip pain if cam deformity was present. Those 14 painful hips had a significantly greater alpha angle at the radial 1:30 clock position than did those who did not develop pain with a cam deformity: 61.5° (range, 57.3°-65.7°) versus 57.9° (range, 56.9°-59.1°), respectively (P = .05). A significantly greater proportion of patients (12%) with limited internal rotation ≤20° (versus 2.7% with internal rotation >20°) went on to develop hip pain (P = .009; relative risk = 3.1 [95% CI, 1.6-6.0]).

The presence of a cam deformity represents a significant risk factor for the development of hip pain. An elevated alpha angle at the 1:30 clock position and decreased internal rotation are associated with an increased risk of developing hip pain. However, not all patients with a cam deformity develop hip pain, and further research is needed to better define those at greater risk of developing degenerative symptoms.

A cam deformity is a major risk factor for hip osteoarthritis, and its formation is thought to be influenced by high-impact sporting activities during growth.

To (1) prospectively study whether a cam deformity can evolve over time in adolescents and whether its formation only occurs during skeletal maturation and (2) examine whether clinical or radiographic features can predict the formation of a cam deformity.

Cohort study (prognosis); Level of evidence, 2.

Preprofessional soccer players (N = 63; mean age, 14.43 years; range, 12-19 years) participated both at baseline and follow-up (mean follow-up, 2.4 ± 0.06 years). At both time points, standardized anteroposterior and frog-leg lateral radiographs were obtained. For each hip, the α angle was measured, and the anterosuperior head-neck junction was classified by a 3-point visual system as normal, flattened, or having a prominence. Differences between baseline and follow-up values for the α angle and the prevalence of each visual hip classification were calculated. Additionally, the amount of internal hip rotation, growth plate extension into the neck, and neck shaft angle were determined.

Overall, there was a significant increase in the prevalence of a cam deformity during follow-up. In boys aged 12 and 13 years at baseline, the prevalence of a flattened head-neck junction increased significantly during follow-up (13.6% to 50.0%; P = .002). In all hips with an open growth plate at baseline, the prevalence of a prominence increased from 2.1% to 17.7% (P = .002). After closure of the proximal femoral growth plate, there was no significant increase in the prevalence or increase in severity of a cam deformity. The α angle increased significantly from 59.4° at baseline to 61.3° at follow-up (P = .018). The amount of growth plate extension was significantly associated with the α angle and hip classification (P = .001). A small neck shaft angle and limited internal rotation were associated with cam deformities and could also significantly predict the formation of cam deformities (α angle >60°) at follow-up.

In youth soccer players, cam deformities gradually develop during skeletal maturation and are probably stable from the time of growth plate closure. The formation of a cam deformity might be prevented by adjusting athletic activities during a small period of skeletal growth, which will have a major effect on the prevalence of hip osteoarthritis.

The iliopsoas tendon has been implicated as a generator of hip pain and a cause of labral injury due to impingement. Arthroscopic release of the iliopsoas tendon has become a preferred treatment for internal snapping hips. Traditionally, the iliopsoas tendon has been considered the conjoint tendon of the psoas major and iliacus muscles, although anatomic variance has been reported.

The iliopsoas tendon consists of 2 discrete tendons in the majority of cases, arising from both the psoas major and iliacus muscles.

Descriptive laboratory study.

Fifty-three nonmatched, fresh-frozen, cadaveric hemipelvis specimens (average age, 62 years; range, 47-70 years; 29 male and 24 female) were used in this study. The iliopsoas muscle was exposed via a Smith-Petersen approach. A transverse incision across the entire iliopsoas musculotendinous unit was made at the level of the hip joint. Each distinctly identifiable tendon was recorded, and the distance from the lesser trochanter was recorded.

The prevalence of a single-, double-, and triple-banded iliopsoas tendon was 28.3%, 64.2%, and 7.5%, respectively. The psoas major tendon was consistently the most medial tendinous structure, and the primary iliacus tendon was found immediately lateral to the psoas major tendon within the belly of the iliacus muscle. When present, an accessory iliacus tendon was located adjacent to the primary iliacus tendon, lateral to the primary iliacus tendon.

Once considered a rare anatomic variant, the finding of ≥2 distinct tendinous components to the iliacus and psoas major muscle groups is an important discovery. It is essential to be cognizant of the possibility that more than 1 tendon may exist to ensure complete release during endoscopy.

Arthroscopic release of the iliopsoas tendon is a well-accepted surgical treatment for iliopsoas impingement. The most widely used site for tendon release is at the level of the anterior hip joint. The findings of this novel cadaveric anatomy study suggest that surgeons should be mindful that more than 1 tendon may be present and require release for curative treatment.

An assessment of the effect of surgical repair or reconstruction on the function of the hip labrum is critical to the advancement of hip preservation surgery; however, validated models of the hip that allow the quantification of labral function in functional joint positions have yet to be developed.

To evaluate (1) whether intra-articular pressures within the hip are regulated by fluid transport between the labrum and femoral head and (2) whether the sealing capacity of the labrum varies with joint posture.

Descriptive laboratory study.

The sealing ability of the hip labrum was measured during fluid infusion into the central compartments of 8 cadaveric specimens. Additionally, the pathway of fluid transfer from the central to the peripheral compartment was assessed via direct visualization in 3 specimens. The effect of joint posture on the sealing capacity of the labrum was determined by placing all 8 specimens in 10 functional postures. The relationship between pressure resistance and 3-dimensional motion of the femoral head within the acetabulum was quantified using motion analysis and computer modeling.

Resistance to fluid transport from the central compartment of the hip was directly controlled by the labrum during loading. Maximum pressure resistance was affected by joint posture (P = .001). Specifically, positions that increased external rotation of the joint (pivoting) provided an improved seal, while positions that increased flexion combined with internal rotation (stooping) augmented the ease of fluid transport from the central to the peripheral compartment. Maximum pressure resistance was associated with the distance between the labrum and femoral head during pivoting.

This study demonstrated that the transfer of fluid from the central compartment of the hip occurs at the junction of the labrum and femoral head. Joint position was shown to strongly affect the sealing function of the labrum and was attributable to the distance between the labrum and femoral head in certain positions.

Altering the relationship between the labrum and femoral head may disrupt the sealing ability of the labrum, potentially leaving the joint at risk for pathological changes with time.

The incidence and arthroscopic treatment of superior labral anterior posterior (SLAP) tears have increased over the past decade. Recent evidence has identified factors associated with poor outcomes, including age, overhead activity, and concomitant rotator cuff tears. Biceps tenodesis has also been suggested as an alternative treatment to repair. Moreover, there are no studies demonstrating effective treatment strategies for failed type II SLAP repairs.

To prospectively evaluate the surgical outcomes of biceps tenodesis for patients who undergo elected revision surgery after an arthroscopically repaired type II SLAP tear.

Case series; Level of evidence, 4.

After institutional review board approval, 46 patients who met failure criteria for an arthroscopically repaired type II SLAP tear elected to undergo open subpectoral tenodesis by 2 fellowship-trained surgeons from 2006 to 2010 at a tertiary care military treatment facility. Objective outcomes were preoperative and postoperative assessments with the American Shoulder and Elbow Surgeons (ASES), Single Assessment Numeric Evaluation (SANE), and Western Ontario Shoulder Instability Index (WOSI) scores and an independent physical examination. Statistical analysis was performed via analysis of variance.

Of the 46 patients, 42 completed the study (91% follow-up rate). The mean age of the patients was 39.2 years, 85% were male, and the mean follow-up period was 3.5 years (range, 2.0-6.0 years). The rate of return to active duty and sports was 81%. There was a clinically and statistically significant improvement across all outcome assessments after revision surgery (preoperative mean scores: ASES = 68, SANE = 64, WOSI = 65; postoperative mean scores: ASES = 89, SANE = 84, WOSI = 81) (P < .0001) and shoulder range of motion (preoperative mean values: forward flexion = 135°, abduction = 125°; postoperative mean values: forward flexion = 155°, abduction = 155°) (P < .0001). There was 1 case of transient musculocutaneous nerve neurapraxia.

Biceps tenodesis is a predictable, safe, and effective treatment for failed arthroscopic SLAP tears at a minimum 2-year follow-up. The majority of patients obtained good to excellent outcomes using validated measures with a significant improvement in range of motion.

Rotator cuff tears are a common cause of pain and disability of the shoulder. Information on the prevalence and identification of potential risk factors could help in early detection of rotator cuff tears and improve treatment outcome.

Patients treated for a symptomatic rotator cuff tear on one side have a higher prevalence of rotator cuff tears and decreased shoulder function on the contralateral side compared with an age- and sex-matched group of healthy individuals.

Case control study; Level of evidence, 3.

One group consisted of 55 patients who had been arthroscopically treated on one shoulder for rotator cuff tear (tear group). In this group, the nonoperated contralateral shoulder was examined. For comparison, the matching shoulder in a control group consisting of 55 subjectively healthy individuals matched by age (±1 year) and sex to the tear group was included. Diagnosis of a rotator cuff tear was made by ultrasound. Outcomes were measured using the Constant score.

The prevalence of supraspinatus tears was significantly higher (P < .0001) in the tear group (67.3%) compared with the control group (11.0%). The Constant score for the activities of daily living subscale, however, was significantly lower (18.4) in the tear group compared with the control group (19.9; P = .012). No other subcategory score nor the overall score showed a significant difference. There was a significantly higher tear prevalence in the tear group of patients aged between 50 and 59 years (P < .001) and 60 and 69 years (P = .004). No tear was diagnosed in the control group in individuals younger than 60 years.

Patients treated for partial and full-thickness rotator cuff tears have a significantly higher risk of having a tear on the contralateral side and have noticeable deficits in their shoulder function regarding activities of daily living even if the tear is otherwise asymptomatic.

The healing rate and clinical outcomes of glenoid bone grafting with nonrigid fixation for patients with recurrent anterior shoulder instability are unknown.

Glenoid bone grafting with nonrigid fixation can yield satisfactory results for patients with recurrent anterior shoulder instability with regard to graft healing and the restoration of shoulder stability.

Case series; Level of evidence, 4.

A total of 52 patients with recurrent anterior shoulder instability underwent Bankart or bony Bankart repair as well as arthroscopic glenoid bone grafting. Allogenic bicortical iliac grafts were used. Instead of firm fixation, the grafts were tethered to the glenoid by sutures from anchors placed in the glenoid surface. Follow-up occurred at 3, 6, 12, and 24 months. Computed tomography and magnetic resonance imaging examinations were performed immediately after surgery and at each follow-up visit to evaluate the healing of the graft and the changes in the repaired capsule-labrum structure. Functional evaluations were taken at 24 months with the Oxford Shoulder Instability Score and the Rowe Score for Shoulder Instability. For the patients who underwent surgery 2.5 years earlier, an additional review was conducted to evaluate the latest stability status of the shoulder. Failure was defined as recurrence of dislocation or instability.

The mean follow-up time was 39 months (range, 24-64 months). In all cases, the grafts healed to the glenoid at 3 or 6 months, and glenoid remodeling was complete within 12 months; in most cases, a robust bone-capsule structure formed on the anterior side of the glenoid. The glenoid defect area changed from 32.7% ± 8.7% (range, 10.7% to 53.9%) to −16.3% ± 3.3% (range, −26.7% to 5.9%), and the glenoid defect width changed from 28.3% ± 8.7% (range, 10.4% to 54.5%) to −16.9% ± 7.3% (range, −33.4% to 2.8%). Compared with the presumed normal glenoid, the final glenoid surface area increased in 94.2% of patients and final glenoid width increased in 96.2% of patients. One patient experienced redislocation and 2 experienced a sense of instability without dislocation, which resulted in a failure rate of 5.8%. Six patients exhibited slight pain. The Oxford score improved from 29.7 ± 5.6 preoperatively to 42.4 ± 3.3 at 2 years postoperatively, and the Rowe score improved from 34.7 ± 6.1 preoperatively to 91.8 ± 2.8 at 2 years postoperatively.

In this study, arthroscopic glenoid bone grafting with nonrigid fixation in combination with Bankart repair resulted in 100% graft healing and the satisfactory restoration of shoulder stability.

In spite of the high prevalence of shoulder stiffness during rotator cuff repair, optimal management remains unclear.

To identify the effect of capsular release during rotator cuff repair on the outcomes of patients with both shoulder stiffness and a rotator cuff tear, based on subgroup analyses.

Cohort study; Level of evidence, 3.

Forty-nine consecutive patients (mean age, 61.5 ± 8.3 years) were enrolled who underwent arthroscopic repair of a small- to large-sized full-thickness rotator cuff tear and manipulation for concomitant shoulder stiffness (passive forward flexion ≤120°, external rotation at the side ≤45°). The first 21 consecutive patients underwent manipulation alone to treat stiffness; the second 28 consecutive patients underwent capsular release with manipulation. Among the 49 patients, 25 showed severe stiffness (forward flexion ≤100°, external rotation at the side ≤30°; 11 in the first series and 14 in the second series), and 15 had diabetes mellitus (30.6%; 6 in the first series and 9 in the second series). Shoulder range of motion was measured 6 weeks, 3 months, 6 months, and 1 year postoperatively and at final follow-up visit. Simultaneously, functional outcome was evaluated by visual analog scale for pain, American Shoulder and Elbow Surgeons score, Constant score, and muscle strength ratio (involved/uninvolved), and cuff integrity was assessed ultrasonographically at least 1 year postoperatively.

All range of motion measurements, functional scores, and muscle strength ratios significantly improved postoperatively regardless of the treatment method of stiffness. No outcome measure differed significantly between patients who did and did not undergo capsular release, regardless of the severity of stiffness, except for a temporary improvement in external rotation at side 3 months postoperatively in favor of those who underwent capsular release in cases with severe stiffness. Among patients with diabetes mellitus however, those who underwent capsular release showed greater improvement in forward flexion after 3 months and 1 year and in external rotation at the side for all time points (all P < .05), except for 6 weeks postoperatively; these patients also had a significantly higher final American Shoulder and Elbow Surgeons score (P = .03). Of 21 patients who underwent manipulation alone and of 28 who underwent capsular release and manipulation, 2 and 1 developed retears, respectively.

Both manipulation and capsular release with manipulation significantly improved range of motion and produced satisfactory functional outcomes. The outcomes did not differ between treatment methods for stiffness regardless of the severity of stiffness. In patients with diabetes mellitus however, capsular release at the time of rotator cuff repair seems to be beneficial, especially for external rotation and final postoperative function.

Glenohumeral internal rotation deficit (GIRD) is the difference in internal rotation range of motion (IRROM) between the dominant and nondominant limbs. Pathological GIRD of greater than 15° to 25° has previously been linked to shoulder and elbow injuries in baseball players. Because of its relationship to shoulder and elbow disorders, research has focused on understanding the underlying factors that contribute to changes in IRROM and ultimately GIRD. The rotation deficit reportedly increases during adolescence, but it remains unclear whether this change is caused by changes in osseous properties or soft tissue tightness.

To evaluate the influence of age group on GIRD, humeral retrotorsion, retrotorsion-adjusted GIRD, and total range of motion (TROM) in healthy baseball players.

Cross-sectional study; Level of evidence, 3.

Four groups of healthy baseball players participated in the study: 52 youth (aged 6-10 years), 52 junior high school (JH) (aged 11-13 years), 70 junior varsity (JV) (aged 14-15 years), and 113 varsity (aged 16-18 years) players. Internal rotation range of motion, external rotation range of motion (ERROM), and humeral retrotorsion were measured bilaterally using a digital inclinometer and diagnostic ultrasound. Retrotorsion-adjusted IRROM was calculated as the available IRROM from the humeral retrotorsion position; TROM was calculated as the sum of IRROM and ERROM; and GIRD, the difference in humeral retrotorsion between limbs, adjusted GIRD, and the difference in TROM between limbs were calculated as the difference between the dominant and nondominant sides. Four separate analyses of variance were used to compare these variables between age groups.

There was a significant group difference in GIRD (F_3,284 = 8.957; P < .001) and a difference in humeral retrotorsion between limbs (F_3,284 = 9.688; P < .001). Also, GIRD was greater in varsity participants compared with youth (mean difference [MD], 5.05°) and JH (MD, 4.95°) participants and in JV participants compared with JH (MD, 5.36°) and youth (MD, 5.47°) participants. The difference in humeral retrotorsion between limbs was greater in varsity participants compared with youth (MD, 8.79°) and JH (MD, 5.52°) participants and in JV participants compared with youth participants (MD, 7.88°). There were no significant differences in adjusted GIRD (F_3,284 = 1.136; P = .335) or TROM (F_3,284 = 1.214; P = .305).

Glenohumeral internal rotation deficit and humeral retrotorsion increased with age in youth/adolescent baseball players, while retrotorsion-adjusted GIRD and TROM remained unchanged. An age-related increase in GIRD is primarily attributed to humeral retrotorsion rather than soft tissue tightness.

While there was an increase in GIRD from youth league to high school participants, TROM and retrotorsion-adjusted GIRD remained constant across the age groups, indicating that this increase between the age groups is not pathological GIRD and may not contribute to an increased injury risk.

Advanced patient age is associated with recurrent tearing and failure of rotator cuff repairs clinically; however, basic science studies have not evaluated the influence of aging on tendon-to-bone healing after rotator cuff repair in an animal model.

This study examined the effect of aging on tendon-to-bone healing in an established rat model of rotator cuff repair using the aged animal colony from the National Institute on Aging of the National Institutes of Health. The authors hypothesized that normal aging decreases biomechanical strength and histologic organization at the tendon-to-bone junction after acute repair.

Controlled laboratory study.

In 56 F344xBN rats, 28 old and 28 young (24 and 8 months of age, respectively), the supraspinatus tendon was transected and repaired. At 2 or 8 weeks after surgery, shoulder specimens underwent biomechanical testing to compare load-to-failure and load-relaxation response between age groups. Histologic sections of the tendon-to-bone interface were assessed with hematoxylin and eosin staining, and collagen fiber organization was assessed by semiquantitative analysis of picrosirius red birefringence under polarized light.

Peak failure load was similar between young and old animals at 2 weeks after repair (31% vs 26% of age-matched uninjured controls, respectively; P > .05) but significantly higher in young animals compared with old animals 8 weeks after repair (86% vs 65% of age-matched uninjured controls, respectively; P < .01). Eight weeks after repair, fibroblasts appeared more organized and uniformly aligned in young animals on hematoxylin and eosin slides compared with old animals. Collagen birefringence analysis of the tendon-to-bone junction demonstrated that young animals had increased collagen fiber organization and similar histologic structure compared with age-matched controls (53.7 ± 2.4 gray scales; P > .05). In contrast, old animals had decreased collagen fiber organization and altered structure compared with age-matched controls (49.8 ± 3.1 gray scales; P < .01).

In a rat model of aging, old animals demonstrated diminished tendon-to-bone healing after rotator cuff injury and repair. Old animals had significantly decreased failure strength and collagen fiber organization at the tendon-to-bone junction compared with young animals. This study implies that animal age may need to be considered in future studies of rotator cuff repair in animal models.

With increasing age and activity level of the population, the incidence of rotator cuff tears is predicted to rise. Despite advances in rotator cuff repair technique, the retear rate remains specifically high in elderly patients. The findings of this research suggest that aging negatively influences tendon-to-bone healing after rotator cuff repair in a validated animal model.

One of the goals of rotator cuff repair is to restore the torn tendon to its original insertion anatomically. However, it is sometimes difficult to restore the entire footprint.

This study was undertaken to evaluate the variables affecting this repair coverage and to discern the differences in retear rate and clinical results between complete and incomplete footprint coverage in rotator cuff surgery.

Case series; Level of evidence, 4.

From 2007 to 2009, a total of 85 consecutive repairs for medium-to-large rotator cuff tears were identified as having complete or incomplete coverage of their original footprints. We defined the complete footprint coverage (CC) group as patients who had >50% of their footprint covered during repair and the incomplete (IC) group as <50% of their footprint. Factors affecting the amount of footprint coverage were evaluated, and multivariable analysis was conducted to identify independent factors. To assess the final outcome according to the amount of footprint coverage, retear and clinical outcomes were compared between the CC and IC groups.

Fifty-seven repairs were defined in the CC group and 28 repairs in the IC group. Preoperatively, age, tear size in coronal oblique and sagittal oblique planes, Goutallier fatty infiltration, and atrophy of the supraspinatus affected the amount of footprint coverage in univariate analysis. In multivariable analysis, however, tear size in the coronal plane was the only independent factor affecting footprint coverage in rotator cuff repair. On postoperative MRI, 45.6% of the CC group had an intact tendon, 45.6% had a delaminated partial retear, and 8.8% had a full-thickness retear; in the IC group, 17.9% had an intact tendon, 60.7% had a delaminated partial retear, and 21.4% had a full-thickness retear. There was a statistically significant difference in the proportion of tendon integrity between groups (P = .028). Clinical scores and range of motion at final follow-up showed no difference between the 2 groups.

Tear size in the coronal plane was the only independent factor affecting the amount of footprint coverage. Repair quality based on retear classification was different between the 2 groups. However, both complete and incomplete footprint coverage in rotator cuff repair showed no differences in clinical scores and range of motion at short-term follow-up.

Ulnar collateral ligament (UCL) reconstructions are relatively common among professional pitchers in Major League Baseball (MLB). To the authors’ knowledge, there has not been a study specifically analyzing pitching velocity after UCL surgery. These measurements were examined in a cohort of MLB pitchers before and after UCL reconstruction.

There is no significant loss in pitch velocity after UCL reconstruction in MLB pitchers.

Cohort study; Level of evidence, 3.

Between the years 2008 to 2010, a total of 41 MLB pitchers were identified as players who underwent UCL reconstruction. Inclusion criteria for this study consisted of a minimum of 1 year of preinjury and 2 years of postinjury pitch velocity data. After implementing exclusion criteria, performance data were analyzed from 28 of the 41 pitchers over a minimum of 4 MLB seasons for each player. A pair-matched control group of pitchers who did not have a known UCL injury were analyzed for comparison.

Of the initial 41 players, 3 were excluded for revision UCL reconstruction. Eight of the 38 players who underwent primary UCL reconstruction did not return to pitching at the major league level, and 2 players who met the exclusion criteria were omitted, leaving data on 28 players available for final velocity analysis. The mean percentage change in the velocity of pitches thrown by players who underwent UCL reconstruction was not significantly different compared with that of players in the control group. The mean innings pitched was statistically different only for the year of injury and the first postinjury year. There were also no statistically significant differences between the 2 groups with regard to commonly used statistical performance measurements, including earned run average, batting average against, walks per 9 innings, strikeouts per 9 innings, and walks plus hits per inning pitched.

There were no significant differences in pitch velocity and common performance measurements between players who returned to MLB after UCL reconstruction and pair-matched controls.

Osteochondral allografting, a restorative treatment option for articular cartilage lesions in the knee, involves transplantation of fresh osteochondral tissue with no tissue matching. Although retrieval studies have not consistently shown evidence of immunologic response, development of anti–human leukocyte antigen class I cytotoxic antibodies has been observed in allograft recipients.

Postallograft antibody formation is related to graft size and may affect clinical outcome.

Case-control study; Level of evidence, 3.

This study retrospectively compared 42 antibody-positive postallograft patients with 42 antibody-negative patients. Groups were matched for age, sex, and body mass index but not intra-articular disease severity. Seventeen patients (20%) were lost to follow-up. Of the remaining 67 patients (33 antibody-positive and 34 antibody-negative), average follow-up time was 50.3 months (range, 24-165 months). Mean age was 38.1 years (range, 15-68 years) with 58% being male. Graft area was categorized as small (<5 cm²), medium (5-10 cm²), or large (>10 cm²). Graft survival and Knee Society function scores were used to measure clinical outcome.

Of the 84 patients, 80 had graft area data. Of 27 patients with large graft area, 19 (70%) had positive postoperative antibody screens, compared with 1 of 16 (6%) with small graft area (P < .001). Graft survival rates in the antibody-positive and antibody-negative groups were 64% and 79%, respectively (P = .152). Mean postoperative Knee Society function scores in surviving antibody-positive and antibody-negative groups were 88.3 and 84.6 points, respectively (P = .482).

Antibody development after fresh, non-tissue-matched osteochondral allograft transplants in the knee appears related to graft size. No difference was observed in clinical outcome between groups. Graft survival is multifactorial, and the effect that the immunologic response has on clinical outcome merits further investigation.

Meniscal allograft transplantation (MAT) is a treatment option for knee pain in young patients with meniscal deficiency in the setting of intact articular surfaces, ligamentous stability, and normal alignment. It is being performed with increasing frequency, and the need for reoperations is not uncommon. A mean survival rate of allografts and indications for reoperations would be helpful information when counseling patients regarding the procedure.

The purpose of this study was to quantify survival for MAT and report findings at reoperation. The hypothesis was that the reoperation rate would be frequent and that the most common secondary surgery would be arthroscopic debridement.

Case series; Level of evidence, 4.

A retrospective review of a prospectively collected database of patients who underwent MAT from 2003 to 2011 was conducted; all surgeries were performed by a single surgeon. The reoperation rate, timing of reoperation, procedure performed at reoperation, and findings at surgery, including the status of the meniscal and articular cartilage, were reviewed. Survival was defined as a lack of revision MAT or knee arthroplasty. Descriptive statistics, log-rank testing, cross-tabulation, and χ² testing were analyzed, with an α value of .05 set as significant.

Of 200 patients who underwent MAT during the study period, 172 patients (86%; mean age, 34.3 ± 10.3 years) were evaluated at a mean of 59 months (range, 24-118 months) with a minimum 2-year follow-up. Forty-one percent of MATs were isolated, while 60% were performed with concomitant procedures. Sixty-four patients (32%) returned to the operating room after their index procedure. Arthroscopic debridement was performed in 59% (38/64) of these patients. The mean time to subsequent surgery was 21 months (range, 2-107 months), with 73% occurring within 2 years. Eight of 172 patients (4.7%) went on to require revision MAT or total knee replacement. Patients requiring secondary surgery within 2 years had an odds ratio of 8.4 (95% CI, 1.6-43.4) for future arthroplasty or MAT revision (P = .007).

In this series, there was a 32% reoperation rate for MAT, with simple arthroscopic debridement being the most common surgical treatment (59%), and a 95% allograft survival rate at a mean of 5 years. Those requiring additional surgery still benefited, having an 88% allograft survival rate, but were at an increased risk of failure. Patients requiring secondary surgery within 2 years had an odds ratio of 8.4 for future arthroplasty or MAT revision.

Matrix-assisted autologous chondrocyte transplantation (MACT) was developed to overcome the limitations of first-generation autologous chondrocyte implantation. Although short-term/midterm results are now available for a small series of patients, the literature still lacks studies on large cohorts of patients evaluated at midterm/long-term follow-up.

Not all patients can have the same benefit from this procedure. The aim of this study is to analyze a large cohort of patients treated with hyaluronan-based MACT to perform clinical profiling and to highlight the patient- and lesion-specific aspects that play a key role in determining the prognosis.

Case series; Level of evidence, 4.

A total of 142 patients were treated for lesions involving the femoral condyles and trochleae; 133 knees were followed up yearly for 7 years. The average size of the defects was 2.3 ± 1.0 cm². The origin was traumatic in 44 cases and degenerative in 57 cases, and 32 knees were affected by osteochondritis dissecans (OCD). The clinical outcome was analyzed using the International Knee Documentation Committee (IKDC), EuroQol visual analog scale, and Tegner scores. The influence of the following factors was analyzed: sex, age, body mass index, site, lesion origin, lesion size, previous or combined surgery, and symptom duration.

A marked improvement in all scores was found: the IKDC subjective score increased from the basal level of 39.6 ± 14.4 to 71.9 ± 19.8 (P < .0005) at 12 months; a further improvement was observed at 24 months (77.0 ± 20.5; P < .0005). The results were stable over time up to the 7-year evaluation (77.4 ± 22.1). The failure rate was 10.7%. Better results were seen in the trochleae, and among femoral condyles, the following factors were found to influence the clinical outcome positively: traumatic and OCD origin, male sex, short symptom duration (for traumatic lesions), small lesion size (for OCD), young age, and no previous surgery.

Treatment with MACT provides good and stable clinical results. Injury origin, sex, symptom duration, lesion size, lesion site, age, and previous surgery might determine the final outcome and can be used as a sort of clinical profiling to guide the surgeon in the choice of this procedure and in giving realistic expectations to patients requiring cartilage treatment.

Chronic patellar tendinopathy (PT) is one of the most common overuse knee disorders. Platelet-rich plasma (PRP) appears to be a reliable nonoperative therapy for chronic PT.

To evaluate clinical and radiological outcomes of 3 consecutive ultrasound (US)–guided PRP injections for the treatment of chronic PT in athletes.

Case series; Level of evidence, 4.

A total of 28 athletes (17 professional, 11 semiprofessional) with chronic PT refractory to nonoperative management were prospectively included for US-guided pure PRP injections into the site of the tendinopathy. The same treating physician at a single institution performed 3 consecutive injections 1 week apart, with the same PRP preparation used. All patients underwent clinical evaluation, including the Victorian Institute of Sport Assessment–Patella (VISA-P) score, visual analog scales (VAS) for pain, and Lysholm knee scale before surgery and after return to practice sports. Tendon healing was assessed with MRI at 1 and 3 months after the procedure.

The VISA-P, VAS, and Lysholm scores all significantly improved at the 2-year follow-up. The average preprocedure VISA-P, VAS, and Lysholm scores improved from 39 to 94 (P < .001), 7 to 0.8 (P < .0001), and 60 to 96 (P < .001), respectively, at the 2-year follow-up. Twenty-one of the 28 athletes returned to their presymptom sporting level at 3 months (range, 2-6 months) after the procedure. Follow-up MRI assessment showed improved structural integrity of the tendon at 3 months after the procedure and complete return to normal structural integrity of the tendon in 16 patients (57%). Seven patients did not recover their presymptom sporting level (among them, 6 were considered treatment failures): 3 patients returned to sport at a lesser level, 1 patient changed his sport activity (for other reasons), and 3 needed surgical intervention.

In this study, application of 3 consecutive US-guided PRP injections significantly improved symptoms and function in athletes with chronic PT and allowed fast recovery to their presymptom sporting level. The PRP treatment permitted a return to a normal architecture of the tendon as assessed by MRI.

Isolated chondral lesions of the patella are particularly challenging to treat, and long-term studies of treated isolated patellar lesions are limited. Previous short-term studies have reported favorable outcomes of autologous chondrocyte implantation (ACI) of the patella and/or trochlea, with a trend toward improvement when anteromedialization (AMZ) of the tibial tubercle was performed with the procedure.

Autologous chondrocyte implantation with concomitant AMZ for symptomatic isolated patellar lesions provides functional and symptomatic improvement in patients at a minimum 5-year follow-up.

Case series; Level of evidence, 4.

Patients with failed primary treatment of isolated patellar full-thickness articular cartilage defects and patellofemoral malalignment who were treated with ACI and AMZ of the tibial tubercle at least 5 years prior were contacted for final postoperative outcome scores. Outcome scales including the International Knee Documentation Committee (IKDC), Lysholm, modified Cincinnati Knee Rating System, and 12-item Short Form Health Survey (SF-12) scores were assessed at baseline and final follow-up.

Of 27 eligible patients, 23 (25 knees) were available for assessment at a mean follow-up of 7.6 years (range, 5.1-11.4 years). Significant improvements from baseline to final follow-up were observed in the IKDC score (from 42.5 to 75.7; P < .0001), modified Cincinnati Knee Rating System score (from 3.0 to 7.0; P < .0001), Lysholm score (from 40.2 to 79.3; P < .0001), and SF-12 score (physical component score: from 41.2 to 47.6; P = .002; mental component score: from 48.1 to 60.7; P = .0001). Most patients (83%; 19/23) rated their surgery as good or excellent. The overall reoperation rate was 40% (10/25) largely because of periosteal hypertrophy (33%). One patient failed at 5.9 years postoperatively and underwent patellofemoral arthroplasty.

Combined ACI and AMZ resulted in significant improvements in symptoms and function with a low incidence of adverse events in patients with isolated symptomatic patellar chondral defects after a mean follow-up of more than 7 years.

Anterior cruciate ligament (ACL) tears are frequently associated with meniscal lesions. Despite improvements in meniscal repair techniques, failure rates remain significant, especially for the posterior horn of the medial meniscus.

To determine whether a systematic arthroscopic exploration of the posterior horn of the medial meniscus with an additional posteromedial portal is useful to identify otherwise unrecognized lesions.

Case series; Level of evidence, 4.

In a consecutive series of 302 ACL reconstructions, a systematic arthroscopic exploration of the posterior horn of the medial meniscus was performed. The first stage of the exploration was achieved through anterior visualization via a standard anterolateral portal. In the second stage, the posterior horn of the medial meniscus was visualized posteriorly via the anterolateral portal with the scope positioned deep in the notch. In the third stage, the posterior horn was probed through an additional posteromedial portal. A χ² test and logistic regression analysis were performed to determine if the time from injury to surgery was associated with the meniscal tear pattern.

A medial meniscal tear was diagnosed in 125 of the 302 patients (41.4%). Seventy-five lesions (60%) located in the meniscal body were diagnosed at the first stage of the arthroscopic exploration. Fifty lesions located in the ramp area were diagnosed: 29 (23.2%) at the second stage and 21 lesions (16.8%) at the third stage after minimal debridement of the superficial soft tissue layer. The latter type of lesion is called a “hidden lesion.” Altogether, the prevalence of ramp lesions in this population was 40%. Meniscal body lesions (odds ratio, 2.6; 95% confidence interval, 1.18-5.18; P < .02) were found to be significantly correlated with a longer delay between injury and surgery.

Posterior visualization and posteromedial probing of the posterior horn of the medial meniscus can help in discovering a higher rate of lesions that could be easily missed through a standard anterior exploration. In numerous cases, these lesions were “hidden” under a membrane-like tissue and were discovered after minimal debridement through a posteromedial portal.

Posterior tibial slope (PTS) has recently been identified as a risk factor for anterior cruciate ligament (ACL) injuries because of an associated increase in anterior tibial translation (ATT) and ACL loading. However, few studies concerning the correlation between PTS and postoperative ATT have been published.

To analyze the relationship between PTS and postoperative ATT in ACL reconstruction (ACLR).

Case control study; Level of evidence, 3.

Included in this retrospective study were 40 consecutive patients who underwent ACLR (28 male, 12 female; median age, 22 years; range, 14-44 years) from October 2010 to June 2011. The patients were divided into 3 groups based on medial and lateral PTS values as measured on MRI. Demographic data and results of the manual maximum side-to-side difference with a KT-1000 arthrometer at 30° of knee flexion before ACLR and at final follow-up were collected; results were divided into ATT ≤2 mm, 2 mm < ATT < 5 mm, and ATT ≥5 mm. First, the distribution of ATT in the 3 groups was compared, and then correlation analysis and logistic regression were conducted to determine the correlation between PTS and ATT. Finally, the thresholds of medial and lateral PTS were calculated.

Results of the ATT measurements were collected at a mean of 27.5 months (range, 24.0-37.0 months) after ACLR. The group with a PTS ≥5° had significantly more cases of ATT ≥5 mm than the group with a PTS <3° (medial PTS: P = .005; lateral PTS: P = .016). There were statistically significant correlations with ATT for both medial (r = 0.43, P = .005) and lateral (r = 0.36, P = .02) PTS. Medial or lateral PTS resulted in the increased probability of ATT ≥5 mm, with an odds ratio of 1.76 (P = .011) and 1.68 (P = .008), respectively. The threshold of an increased risk of ATT ≥5 mm was a medial PTS >5.6° (P = .003) or a lateral PTS >3.8° (P = .002).

There was a significant correlation between PTS and postoperative anterior knee static stability in this study. Patients with a steeper medial or lateral PTS showed a higher risk of ATT ≥5 mm at thresholds of 5.6° and 3.8°, respectively.

There are limited empirical data available regarding the relationship between concussion history and neurocognitive functioning in active National Football League (NFL) players in general and NFL draft picks in particular. Potential NFL draft picks undergo 2 neurocognitive tests at the National Invitational Camp (Scouting Combine) every year: the Wonderlic and, since 2011, the Immediate Post-concussion Assessment and Cognitive Testing (ImPACT). After conclusion of the combine and before the draft, NFL teams invite potential draft picks to their headquarters for individual visits where further assessment may occur.

To examine the relationship between concussion history and neurocognitive performance (ImPACT and Wonderlic) in a sample of elite NFL draft picks.

Cohort study; Level of evidence, 3.

Over 7 years, 226 potential draft picks were invited to visit a specific NFL team’s headquarters after the combine. The athletes were divided into 3 groups based on self-reported concussion history: no prior concussions, 1 prior concussion, and 2 or more prior concussions. Neurocognitive measures of interest included Wonderlic scores (provided by the NFL team) and ImPACT composite scores (administered either at the combine or during a visit to the team headquarters). The relationship between concussion history and neurocognitive scores was assessed, as were the relationships among the 2 neurocognitive tests.

Concussion history had no relationship to neurocognitive performance on either the Wonderlic or ImPACT.

Concussion history did not affect performance on either neurocognitive test, suggesting that for this cohort, a history of concussion may not have adverse effects on neurocognitive functioning as measured by these 2 tests. This study reveals no correlation between concussion history and neurocognitive test scores (ImPACT, Wonderlic) in soon-to-be active NFL athletes.

The incidence of lower extremity injuries in female soccer players is high, but the risk factors for injuries are unknown.

To investigate risk factors for lower extremity injuries in elite female soccer players.

Cohort study; Level of evidence, 3.

Players in the Norwegian elite female soccer league (N = 12 teams) participated in baseline screening tests before the 2009 competitive soccer season. The screening included tests assessing maximal lower extremity strength, dynamic balance, knee valgus angles in a drop-jump landing, knee joint laxity, generalized joint laxity, and foot pronation. Also included was a questionnaire to collect information on demographic data, elite-level experience, and injury history. Time-loss injuries and exposure in training and matches were recorded prospectively in the subsequent soccer season using weekly text messaging. Players reporting an injury were contacted to collect data regarding injury circumstances. Univariate and multivariate regression analyses were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for ±1 standard deviation of change.

In total, 173 players underwent complete screening tests and registration of injuries and exposure throughout the season. A total of 171 injuries in 107 players (62%) were recorded; ligament and muscle injuries were the most frequent. Multivariate analyses showed that a greater body mass index (BMI) (OR, 1.51; 95% CI, 1.21-1.90; P = .001) was the only factor significantly associated with new lower extremity injuries. A greater BMI was associated with new thigh injuries (OR, 1.51; 95% CI, 1.08-2.11; P = .01), a lower knee valgus angle in a drop-jump landing was associated with new ankle injuries (OR, 0.64; 95% CI, 0.41-1.00; P = .04), and a previous knee injury was associated with new lower leg and foot injuries (OR, 3.57; 95% CI, 1.27-9.99; P = .02), whereas none of the factors investigated influenced the risk of new knee injuries.

A greater BMI was associated with lower extremity injuries in elite female soccer players.

Increased knowledge on risk factors for lower extremity injuries enables more targeted prevention strategies with the aim of reducing injury rates in female soccer players.

Identifying the risk factors associated with a bone stress injury (BSI), including stress reactions and stress fractures, may aid in targeting those at increased risk and in formulating prevention guidelines for exercising girls and women.

To evaluate the effect of single or combined risk factors as defined by the female athlete triad—a syndrome involving 3 interrelated spectrums consisting of energy availability, menstrual function, and bone mass—with the incidence of BSIs in a multicenter prospective sample of 4 cohorts of physically active girls and women.

Cohort study; Level of evidence, 3.

At baseline, participants’ (N = 259; mean age, 18.1 ± 0.3 years) anthropometric characteristics, eating attitudes and behaviors, menstrual function, sports participation or exercise activity, and pathological weight control behaviors were assessed. Dual-energy x-ray absorptiometry (DXA) measured the bone mass of the whole body, total hip, femoral neck, lumbar spine, and body composition. Participants were followed prospectively for the occurrence of injuries; those injuries confirmed by a physician were recorded.

Twenty-eight participants (10.8%) incurred a BSI. Forty-six percent of those who had ≥12 h/wk of purposeful exercise, a bone mineral density (BMD) Z score <–1.0, and who exhibited 3 to 4 of the following: BMI <21.0 kg/m², oligo- or amenorrhea, elevated dietary restraint, and/or participation in a leanness sport exercise/activity at baseline, incurred a BSI during the prospective study period. Single factors significantly (P < .05) associated with the development of a BSI included ≥12 h/wk of purposeful exercise (14.7%), BMI <21.0 kg/m² (15.3%), and low bone mass (BMD Z score <–1.0; 21.0%). The strongest 2- and 3-variable combined risk factors were low BMD (Z score <–1.0) + ≥12 h/wk of exercise, with 29.7% incurring a BSI (odds ratio [OR], 5.1; 95% CI, 2.2-12.1), and ≥12 h/wk of exercise + leanness sport/activity + dietary restraint, with 46.2% incurring a BSI (OR, 8.7; 95% CI, 2.7-28.3).

In the sample, which included female adolescents and young adults participating in competitive or recreational exercise activities, the risk of BSIs increased from approximately 15% to 20% for significant single risk factors to 30% to 50% for significant combined female athlete triad–related risk factor variables. These data support the notion that the cumulative risk for BSIs increases as the number of Triad-related risk factors accumulates.

High school and professional athletes with a history of orthopaedic surgery have decreased career lengths and are at a greater risk for reinjury compared with their peers. It is unknown whether the same risk applies to intercollegiate athletes.

To determine the effect of prior knee surgery in National Collegiate Athletic Association (NCAA) Division I athletes in the United States.

Cohort study; Level of evidence, 3.

Division I athletes who began participation in collegiate athletics at a single institution from fall 2003 to spring 2008 were identified. Athletes with a history of orthopaedic surgery were identified through preparticipation evaluation forms. Data on the number of seasons and games played, number of days missed, diagnostic imaging, athletic injuries sustained, and surgical operations during college were collected through medical records and the Sports Injury Monitoring System (SIMS).

During the 5-year study period, 456 athletes completed preparticipation evaluation forms. Of these, 104 athletes (22.8%) had a history of orthopaedic surgery (Ortho group). Forty-eight (10.5% of all athletes) had a history of knee surgery (Knee group), 16 (3.5%) had a history of anterior cruciate ligament reconstruction (ACL group), and 28 (6.1%) had a history of multiple surgeries (Multiple group). Days missed per season due to any injury and due to knee injury were increased for all surgical groups compared with controls (P < .016). The rate of knee injury and knee surgery while in college was significantly increased for all surgery groups. Athletes in the Knee and ACL groups were 6.8- and 19.6-fold more likely to sustain a knee injury and 14.4- and 892.9-fold more likely to undergo a knee surgery during their collegiate careers compared with controls (P < .001). The number of MRIs per season were 0.83 for the Knee group (P < .001), 1.29 for the ACL (P = .009), and 0.97 for the Multiple group (P < .001), compared with 0.37 for controls. Average career length and percentage of games played were not significantly different between any of the surgery groups compared with controls.

Athletes who had a history of knee surgery before participation in collegiate athletics miss more days due to injury, have increased rates of knee injury and knee surgery, and require more MRIs during their collegiate careers than their peers.

There is still much that we do not know about differences in sports injuries between young male and female athletes and the factors that may increase the risk for injuries in this regard.

To describe and compare differences between males and females in pediatric sports-related injuries.

Cross-sectional study; Level of evidence, 3.

A retrospective chart review was performed using a 5% random sampling (N = 2133) of medical records of children aged 5 to 17 years seen over 10 years in a sports medicine clinic at a large academic pediatric hospital. Information was collected and analyzed on age, sex, height, weight, injury type (overuse vs acute/traumatic), location of injury, and sports involvement.

Overall, female athletes had a higher percentage of overuse injuries (62.5%) compared with traumatic injuries (37.5%); the opposite was seen in male athletes (41.9% vs 58.2%, respectively; P < .001). Looking at specific areas of injury, female athletes sustained more injuries to the lower extremity (65.8%) and spine (11.3%) as compared with male athletes (53.7% and 8.2%, respectively). Male patients had a greater percentage of injuries to the upper extremity (29.8%) as compared with female patients (15.1%). The type of hip/pelvis injuries differed greatly by sex, with females sustaining more overuse (90.9%) and soft tissue injuries (75.3%) versus males, who suffered injuries that tended to be traumatic (58.3%) and bony (55.6%) in nature. Males were more likely than females to participate in team and contact/collision sports. The percentage of females with patellofemoral knee pain was approximately 3 times greater than that of males (14.3% vs 4.0%, respectively; P < .001). Males were twice as likely as females to be diagnosed with osteochondritis dissecans (8.6% vs 4.3%, respectively; P < .001) and fractures (19.5% vs 8.2%, respectively; P < .001). The percentage of males and females who sustained an anterior cruciate ligament injury was almost equal (10.0% and 8.9%, respectively; P = .369).

Sports injuries in young males and females differed by injury type, diagnosis, and body area. These results may be related to the referral patterns unique to the division of the hospital, including a high number of female dancers. Further investigation is required to better understand the injury risk in pediatric male and female athletes.

Because chondrocyte viability is imperative for successful osteochondral allograft transplantation, sterilization techniques must provide antimicrobial effects with minimal cartilage toxicity. Chlorhexidine gluconate (CHG) is an effective disinfectant; however, its use with human articular cartilage requires further investigation.

To determine the maximal chlorhexidine concentration that does not affect chondrocyte viability in allografts and to determine whether this concentration effectively sterilizes contaminated osteoarticular grafts.

Controlled laboratory study.

Osteochondral plugs were subjected to pulse lavage with 1-L solutions of 0.002%, 0.01%, 0.05%, and 0.25% CHG and cultured for 0, 1, 2, and 7 days in media of 10% fetal bovine serum and antibiotics. Chondrocyte viability was determined via LIVE/DEAD Viability Assay. Plugs were contaminated with Staphylococcus aureus and randomized to 4 treatment groups. One group was not contaminated; the 3 others were contaminated and received no treatment, saline pulse lavage, or saline pulse lavage with 0.002% CHG. Serial dilutions were plated and colony-forming units assessed.

The control group and the 0.002% CHG group showed similar cell viability, ranging from 67% ± 4% to 81% ± 22% (mean ± SD) at all time points. In the 0.01% CHG group, cell viability was reduced in comparison with control by 2-fold at day 2 and remained until day 7 (P < .01). The 0.05% and 0.25% CHG groups showed a 2-fold reduction in cell viability at day 1 (P < .01). At day 7, cell viability was reduced to 15% ± 18% (4-fold decrease) for the 0.05% CHG group and 10% ± 19% (6-fold decrease) for the 0.25% CHG group (P < .01). Contaminated grafts treated with 0.002% CHG demonstrated no colony-forming units.

Pulse lavage with 0.002% CHG does not cause significant cell death within 7 days after exposure, while CHG at concentrations >0.002% significantly decreases chondrocyte viability within 1 to 2 days after exposure and should therefore not be used for disinfection of osteochondral allograft. Pulse lavage does not affect chondrocyte viability but cannot be used in isolation to sterilize contaminated fragments. Overall, 0.002% CHG was shown to effectively decontaminate osteoarticular fragments.

This study offers a scientific protocol for sterilizing osteochondral fragments that does not adversely affect cartilage viability.

Low compliance with training programs is likely to be one of the major reasons for inconsistency of the data regarding the effectiveness of current anterior cruciate ligament (ACL) injury prevention programs. Training methods that reduce training time and cost could favorably influence the effectiveness of ACL injury prevention programs. A newly designed knee extension constraint training device may serve this purpose.

(1) Knee extension constraint training for 4 weeks would significantly increase the knee flexion angle at the time of peak impact posterior ground-reaction force and decrease peak impact ground-reaction forces during landing of a stop-jump task and a side-cutting task, and (2) the training effects would be retained 4 weeks after completion of the training program.

Controlled laboratory study.

Twenty-four recreational athletes were randomly assigned to group A or B. Participants in group A played sports without wearing a knee extension constraint device for 4 weeks and then played sports while wearing the device for 4 weeks, while participants in group B underwent a reversed protocol. Both groups were tested at the beginning of week 1 and at the ends of weeks 4 and 8 without wearing the device. Knee joint angles were obtained from 3-dimensional videographic data, while ground-reaction forces were measured simultaneously using force plates. Analyses of variance were performed to determine the training effects and the retention of training effects.

Participants in group A significantly increased knee flexion angles and decreased ground-reaction forces at the end of week 8 (P ≤ .012). Participants in group B significantly increased knee flexion angles and decreased ground-reaction forces at the ends of weeks 4 and 8 (P ≤ .007). However, participants in group B decreased knee flexion angles and increased ground-reaction forces at the end of week 8 in comparison with the end of week 4 (P ≤ .009).

Knee extension constraint training for 4 weeks significantly altered lower extremity movement patterns and transferred these changes in lower extremity movement patterns to stop-jump and side-cutting tasks in which ACL injuries frequently occur. Training effects were retained 4 weeks after the training was completed but were diminished in magnitude.

A knee extension constraint device may be a useful training tool in future ACL injury prevention programs to alter movement patterns without extra training time.

Injuries to the sternoclavicular (SC) joint typically occur with high-energy mechanisms such as those obtained in automobile accidents or contact sports. Many disorders of the SC joint can be treated nonoperatively. However, surgical treatment may be indicated for locked posterior dislocations; symptomatic, chronic instability; or persistent, painful osteoarthritis that fails nonoperative therapy.

To provide an updated review on the current diagnosis and management of instability and degenerative arthritis of the SC joint.

Current concepts review.

A preliminary PubMed database search using the terms sternoclavicular instability, dislocation, arthritis, resection, and stabilization was performed in August 2012. All anatomic and biomechanical studies, review articles, case reports, case series, and technique papers that were relevant to the topic were included.

The search identified 929 articles, 321 of which, after screening of the titles and abstracts, were considered potentially relevant to this study. Of the 321 articles, 30 were anatomic or imaging studies, 2 were biomechanical studies, 69 were review papers, 189 were case series or reports, and 31 were technique papers. The majority of these studies were classified as evidence level 4, with a few scattered level 3 studies. Because the level of evidence obtained from this search was not adequate for systematic review (or meta-analysis), a current concepts review of the diagnosis and management of SC joint instability and degenerative arthritis is presented.

Injuries to the SC joint are uncommon. Recognition and classification of these injuries are critical to proper management, thus minimizing potential long-term sequelae such as posttraumatic arthritis and recurrent instability. Although nonoperative therapy is the modality of choice in anterior dislocations, posterior dislocations require special attention because of the presence of vulnerable posterior hilar structures. Surgical management of chronic instability and degenerative arthritis of the SC joint includes resection arthroplasty of the medial clavicle with or without reconstruction of the sternoclavicular ligaments with graft material. Although resection is typically performed open, an arthroscopic technique is described that theoretically decreases operating and recovery times while also decreasing the risk of iatrogenic injury. Currently, when reconstruction is needed for stability, a figure-of-8 graft reconstruction is the recommended method based on biomechanical data and small clinical series.