The American Journal of Sports Medicine

Femoroacetabular impingement (FAI) is one of the most common causes of hip osteoarthritis, yet the factors controlling disease progression are poorly understood.

To investigate rates of initial and subsequent symptoms in the contralateral hip of patients with FAI, and identify predictors of disease progression (symptom development and surgical intervention) in the contralateral hip.

Cohort study; Level of evidence, 2.

This prospective study included a minimum 5-year follow-up of the contralateral hip in 179 patients undergoing FAI surgery. Symptoms (moderate pain) and surgical progression were monitored. Univariate and multivariate analyses compared patient-specific and imaging characteristics of symptomatic patients with those who remained asymptomatic to identify factors associated with disease progression.

A total of 150 patients (84% follow-up) were followed for a mean of 7.1 years (range, 5-11 years). Thirty-nine of these patients (26% [39/150]) had contralateral hip symptoms at initial evaluation. Of those without contralateral hip symptoms at initial evaluation, 32% (36/111) had developed contralateral hip symptoms by latest follow-up. Those who developed symptoms during the study period had a lower anteroposterior head-neck offset ratio (0.153 vs 0.165; P = .005), decreased total arc of rotation in 90° of flexion (39.9° vs 51.1°; P = .005), and decreased external rotation in 90° of flexion (28.6° vs 37.1°; P = .003) compared with those who never developed symptoms. Age, sex, body mass index, alpha angle, lateral center-edge angle, internal rotation in flexion, and University of California, Los Angeles (UCLA), activity score were similar between these groups. Those with contralateral symptoms at initial evaluation progressed to contralateral surgery at a rate of 41% (16/39) and those who developed contralateral symptoms during the study period progressed to contralateral surgery at a rate of 28% (10/36). Among those with contalateral hip symptoms (either present initially or developed during study period)), younger age (24.6 vs 34.1 years; P < .001) and baseline UCLA activity score ≥9 (P = .003) were associated with progression to surgery. By Kaplan-Meier analysis, 64%, 54%, and 48% of patients remained free of contralateral hip symptoms at 2, 5, and 10 years.

At a mean follow-up of 7.1 years, significant symptoms in the contralateral hip of patients with FAI were present in approximately 50% of patients. FAI disease progression (symptom development and surgical intervention) was associated with decreased hip rotation arc, decreased external rotation, and decreased head-neck offset ratio. In symptomatic patients, younger age and UCLA activity score ≥9 were associated with progression to surgery. These findings represent important factors for patient counseling and risk modeling in FAI.

Previous studies have demonstrated a clinically impactful change in patients between 1 and 2 years after hip arthroscopy. Assessment of differences in patient-specific factors between patients who remain the same and those who change (ie, either improve or decline) could provide valuable outcome information for orthopaedic surgeons treating those patients.

To identify patients who experienced change in functional status between 1 and 2 years after hip arthroscopy for femoroacetabular impingement syndrome and assess differences in patient-specific factors between those who improved, remained the same, or declined in functional status.

Cohort study; Level of evidence, 3.

Prospectively collected data for patients who underwent hip arthroscopy at 1 of 7 centers were analyzed retrospectively at 1 year and 2 years postoperatively. Patients were categorized as “improved,”“remained the same,” or “declined” between 1- and 2-year follow-up based on the 12-item International Hip Outcome Tool (iHOT-12) minimal clinically important difference (MCID) value. A 1-way analysis of variance was used to assess differences in iHOT-12 scores, age, body mass index (BMI), alpha angle, and center-edge angle (CEA) between groups. Chi-square analyses were used to assess differences in the proportions of male and female patients in the outcome groups.

The study included 753 patients (515 women and 238 men), whose mean ± SD age was 34.7 ± 12 years. Average 1-year (±1 month) and 2-year (±2 months) iHOT-12 scores for all patients were 73.7 and 74.9, respectively. Based on the calculated MCID of ±11.5 points, 162 (21.5%) patients improved, 451 (59.9%) remained the same, and 140 (18.6%) declined in status between 1- and 2-year follow-up. Those who improved between 1 and 2 years had lower 1-year iHOT-12 scores (P < .0005). We found no difference in age, BMI, alpha angle, CEA, or sex between groups (P > .05).

Between 1- and 2-year follow-up assessments, 21.5% of patients improved and 18.6% declined in self-reported functional status. Those with iHOT-12 scores indicating abnormal function at 1 year improved beyond the MCID at 2 years follow-up. Thus, any decisions about the failure or success of arthroscopic hip procedures should not be made until at least the 2-year follow-up. Failing to thrive at 1-year follow-up may not accurately predict outcomes at year 2 or beyond. This could potentially decrease the perceived need for revision surgery in patients who do not thrive before 2-year follow-up.

The use of patient-reported outcomes (PROs) is common practice in the treatment of patients undergoing hip arthroscopy. While the prospective collection of PROs is preferred, retrospective collection involving patient recall is not uncommon and may be subject to bias.

To assess the presence of recall bias between prospectively and retrospectively collected PRO scores in hip arthroscopy.

Cohort study; Level of evidence, 2.

Patients who underwent hip arthroscopy between 2015 and 2021 and provided preoperative baseline responses for the International Hip Outcome Tool–12 (iHOT-12), the Hip disability and Osteoarthritis Outcome Score–Physical Shortform (HOOS-PS), and the modified Harris Hip Score (mHHS) were eligible for recruitment. After surgery, participants were asked to complete a study-specific survey and the same preoperative PROs retrospectively. Agreements between the prospective and retrospective scores were assessed, and associations between score discrepancies and patient characteristics were identified.

A total of 94 patients (43.3% participation rate) completed study requirements and were included for analysis. The mean ± standard deviation duration of symptoms before surgery was 25.3 ± 32.8 months, and the mean duration to recall (from the day of surgery) for the PROs was 29.6 ± 22.2 months. The iHOT-12 (intraclass correlation coefficient [ICC], 0.409; P < .001) and HOOS-PS (ICC, 0.415; P < .001) scores had low agreement between prospectively and retrospectively collected scores. The mHHS showed moderate agreement (ICC, 0.598; P < .001). The mean scores for the iHOT-12 (41.4 ± 22.6 vs 34.6 ± 16.3; P < .01), HOOS-PS (29.7 ± 18.5 vs 40.9 ± 17.1; P < .001), and mHHS (62.7 ± 16.5 vs 54.5 ± 14.8; P < .001) were all significantly different prospectively versus retrospectively. The average changes in score for the iHOT-12, HOOS-PS, and mHHS were −6.8, 11.2, and −8.2, respectively. Duration to recall and female sex were predictors of the difference between prospectively and retrospectively collected iHOT-12 data, while no predictors were significant for the HOOS-PS or mHHS.

The retrospective collection of PROs for hip arthroscopy procedures is subject to bias. On average, retrospective (recalled) PROs reflected worse pain/function than their prospectively recorded counterpoints; therefore, retrospective patient recall is an unreliable source of clinical data, and the prospective collection of iHOT-12, mHHS, and HOOS-PS data should be prioritized.

Femoroacetabular impingement syndrome is characterized by chondrolabral damage and hip pain. The specific biomechanics used by people with femoroacetabular impingement syndrome during daily activities may exacerbate their symptoms. Femoroacetabular impingement syndrome can be treated nonoperatively or surgically; however, differential treatment effects on walking biomechanics have not been examined.

To compare the 12-month effects of physical therapist–led care or arthroscopy on trunk, pelvis, and hip kinematics as well as hip moments during walking.

Secondary analysis of multi-centre, pragmatic, two-arm superiority randomized controlled trial subsample; Level of evidence, 1.

A subsample of 43 participants from the Australian Full randomised controlled trial of Arthroscopic Surgery for Hip Impingement versus best cONventional (FASHIoN trial) underwent gait analysis and completed the International Hip Outcome Tool (iHOT-33) at both baseline and 12 months after random allocation to physical therapist–led care (personalized hip therapy; n = 22; mean age 35; 41% female) or arthroscopy (n = 21; mean age 36; 48% female). Changes in trunk, pelvis, and hip biomechanics were compared between treatment groups across the gait cycle using statistical parametric mapping. Associations between changes in iHOT-33 and changes in hip kinematics across 3 planes of motion were examined.

As compared with the arthroscopy group, the personalized hip therapy group increased its peak hip adduction moments (mean difference = 0.35 N·m/body weight·height [%] [95% CI, 0.05-0.65]; effect size = 0.72; P = .02). Hip adduction moments in the arthroscopy group were unchanged in response to treatment. No other between-group differences were detected. Improvements in iHOT-33 were not associated with changes in hip kinematics.

Peak hip adduction moments were increased in the personalized hip therapy group and unchanged in the arthroscopy group. No biomechanical changes favoring arthroscopy were detected, suggesting that personalized hip therapy elicits greater changes in hip moments during walking at 12-month follow-up. Twelve-month changes in hip-related quality of life were not associated with changes in hip kinematics.

While labral repair has been widely adopted as the first line treatment for labral injury during hip arthroscopy, there is no widespread consensus on the procedural technique, including the number of anchors that should be used to avoid recurrent instability and revision surgery.

To determine if anchor density can predict patient-reported outcomes after arthroscopic labral repair in the hip.

Cohort study; Level of evidence, 3.

Patients aged 18 to 50 years who underwent primary hip arthroscopic surgery with labral repair between January 2011 and December 2016 were identified from a prospectively collected database. Exclusion criteria consisted of previous ipsilateral surgery, osteoarthritis (Tönnis grade >1), and severe cartilage defects (Outerbridge grade III/IV) or concomitant labral reconstruction, capsular reconstruction, or microfracture. Minimum 2-year patient-reported outcomes (modified Harris Hip Score [mHHS], Hip Outcome Score [HOS]–Activities of Daily Living [ADL], HOS–Sport Specific Subscale [SSS], 12-Item Short Form Health Survey [SF-12]), rates of achieving the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) for each score, revision surgery rate, and rate of conversion to total hip arthroplasty (THA) were compared based on anchor density (number of anchors per millimeter of labral tear).

A total of 634 hips (575 patients) with a mean age of 30.4 ± 9.5 years (range, 18.0-49.9 years) met inclusion criteria. The mean labral tear size was 31 ± 11 mm (range, 2-70 mm) with a median number of anchors used for labral repair of 3 (range, 1-7) and mean anchor density of 0.11 ± 0.08 anchors (range, 0.03-1.33) per millimeter of labral tear. Hips with a minimum 2-year follow-up (451/634 [71.1%]) had significant improvements on the mHHS, HOS-ADL, HOS-SSS, and SF-12 Physical Component Summary (P < .001 for all). There was no significant correlation detected between anchor density or number of anchors used and postoperative scores (correlation coefficient range, –0.05 to 0.17; P > .05 for all). The rate of revision surgery was 6.4% (28 patients), with 8 hips found to have labral tears and/or deficiency on revision. Additionally, 6 hips (1.3%) had to undergo THA at a mean of 3.6 ± 2.1 years (range, 2.0-5.5 years).

Anchor density did not have a correlation with postoperative outcomes, achieving the MCID or PASS, revision hip arthroscopic surgery, complications, or conversion to THA.

Anterior cruciate ligament (ACL) injuries are among the most common knee injuries sustained in elite sport, and athletes generally undergo ACL reconstruction (ACLR) to facilitate their return to sport. ACL graft rupture is a career-threatening event for elite athletes.

The purpose of this study was to determine the risk factors for graft failure in professional athletes undergoing ACLR. It was hypothesized that athletes who underwent combined ACLR with a lateral extra-articular procedure (LEAP) would experience significantly lower rates of graft rupture in comparison with those who underwent isolated ACLR.

Cohort study; Level of evidence, 3.

Professional athletes who underwent primary ACLR with a minimum follow-up of 2 years were identified from the Santy database. Patients were excluded if they underwent major concomitant procedures, including multiligament reconstruction surgery or osteotomy. Further ipsilateral knee injury, contralateral knee injury, and any other reoperations or complications after the index procedure were identified by interrogation of the database and review of the medical notes.

A total of 342 athletes with a mean follow-up of 100.2 ± 51.9 months (range, 24-215 months) were analyzed. Graft failures totaling 31 (9.1%) were reported, requiring revision surgery because of symptomatic instability. The rate of graft failure was significantly higher when ACLR was not combined with a LEAP (15.5% vs 6.0%; P = .0105) and in athletes aged 21 years or younger (13.8% vs 6.6%; P = .0290). A multivariate analysis was performed using the Cox model and demonstrated that athletes undergoing an isolated ACLR were at >2-fold risk of ACL graft rupture (hazard ratio [HR], 2.678 [1.173; 4.837], P = .0164) when compared with those undergoing a combined ACLR with a LEAP. Additionally, athletes aged ≤21 years were also at >2-fold risk of graft failure (HR, 2.381 [1.313; 5.463]; P = .0068) than those aged >21 years. Sex, sport, and graft type were not found to be significant risk factors for graft failure.

Professional athletes undergoing isolated ACLR and aged ≤21 years are at >2-fold greater risk of graft failure. Orthopaedic surgeons treating elite athletes should combine an ACLR with a LEAP to improve ACL graft survivorship.

Although several factors are associated with anterior cruciate ligament (ACL) rerupture, the effect of anatomic factors associated with ACL rupture on ACL rerupture development has not been evaluated.

To determine individual anatomic parameters independently associated with ACL rerupture and the diagnostic values of these parameters.

Case-control study; Level of evidence, 3.

A total of 91 male patients with ACL rerupture and 182 age-, sex-, body mass index–, and side dominance–matched patients without rerupture who underwent ACL reconstruction with a 5-year follow-up were included. In all, 35 parameters that were previously defined as risk factors for primary ACL rupture were compared between the 2 groups. Uni- and multivariate logistic regression models were created to evaluate independently associated factors. Receiver operating characteristic curve analysis was performed for independently associated parameters to predict sensitivity, specificity, and cutoff values.

The mean ± standard deviation age of patients at the time of index surgery was 26.5 ± 6.7 years. Notch shape index (P = .014), tibial proximal anteroposterior (AP) distance (TPAPD) (P < .001), lateral femoral condylar AP distance (LCAPD)/TPAPD ratio (P < .001), medial meniscal cartilage bone height (P < .001), and lateral meniscal bone angle (P = .004) were found to be significantly different between the 2 groups. Only the LCAPD/TPAPD ratio (odds ratio, 2.713; 95% CI, 1.998-5.480; P < .001) was found to be independently associated with ACL rerupture development. The LCAPD/TPAPD ratio revealed 78.9% sensitivity and 75.5% specificity (area under the curve, 0.815; 95% CI, 0.760-0.870) for values above 1.52.

The LCAPD/TPAPD ratio can be used to distinguish patients who are at risk of developing ACL rerupture from patients who are not. In the clinical practice, findings of this study may help to develop surgical and nonsurgical preventive strategies in ACL rerupture development.

The optimum management strategy after failure of revision anterior cruciate ligament reconstruction (RACLR) is not clearly defined. The literature evaluating differences in outcomes between surgical and nonsurgical management is sparse.

The purpose was to evaluate the outcomes of surgical versus nonsurgical management of failed first RACLR. It was hypothesized that the long-term clinical outcomes of second RACLR would be superior with respect to knee stability, return to sport, and patient-reported outcome measures when compared with nonsurgical treatment.

Cohort study; Level of evidence, 3.

Patients who experienced failure of first RACLR were evaluated. All participants followed the same rehabilitation protocol regardless of whether they underwent nonsurgical treatment or a second RACLR. Follow-up comprised regular clinical review and a standardized telephone interview at the end of the study period. Patient-reported outcome measures were recorded at the final follow-up.

A total of 41 patients with a mean follow-up of 104 ± 52.7 months (range, 40-140 months) were evaluated. Of these, 31 underwent a second RACLR, and 10 patients chose nonsurgical treatment. There was a high rate of return to sport in both groups, but patients undergoing second RACLR had significantly better Tegner (6.35 vs 4.8; P = .012), Lysholm (88.5 vs 78.3; P = .0353), Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (72.6 vs 56.3; P = .0490), and KOOS Sport and Recreation scores (81.4 vs 62.5; P = .0033). Significantly more patients undergoing second RACLR achieved the Patient Acceptable Symptom State for KOOS Sport and Recreation than those who underwent nonsurgical management (74.2% vs 30%; P = .015). The most important predictor of failure to achieve a good/excellent Lysholm score in multivariate analysis was nonsurgical management (P = .0095).

Both second RACLR and nonsurgical management of failed first RACLR were associated with high rates of return to sport. However, second RACLR was associated with significantly better functional outcome scores with respect to Tegner, Lysholm, KOOS Quality of Life, and KOOS Sport and Recreation scores compared to nonsurgical management. In addition, nonsurgical treatment was the only significant predictor of failure to achieve a good/excellent Lysholm score at the final follow-up, and this was likely a function of inferior knee stability in that group.

Young patients undergoing anterior cruciate ligament (ACL) reconstruction (ACLR) are at a particularly high risk of graft ruptures compared with adults. Recent studies have demonstrated significant reductions in ACL graft rupture rates in high-risk adult populations when a lateral extra-articular procedure is performed, but comparative studies in pediatric and adolescent populations are currently lacking in the literature.

The purpose of this study was to compare the clinical outcomes of isolated ACLR versus combined ACLR and lateral extra-articular tenodesis (LET) when using the Arnold-Coker modification of the MacIntosh procedure in early adolescent patients. The hypothesis was that combined procedures would be associated with a significantly reduced risk of graft ruptures.

Cohort study; Level of evidence, 3.

A retrospective analysis of consecutive early adolescent patients who underwent ACLR using a hamstring tendon autograft with or without the Arnold-Coker modification of the MacIntosh procedure was conducted. Patients with ≥1 additional risk factors for a graft rupture were offered LET in addition to ACLR (pivot-shift grade 2 or 3, high level of sporting activity defined as Tegner activity score ≥7, participation in pivoting sports, and Segond fractures). Clinical outcomes including graft rupture rates, patient-reported outcome measure scores (Knee injury and Osteoarthritis Outcome Score and subjective International Knee Documentation Committee), knee stability, return-to-sports rates, reoperation rates, and complications were assessed. Comparisons between variables were assessed with the chi-square or Fisher exact test for categorical variables and the Student or Wilcoxon test for quantitative variables. Multivariate analyses were undertaken to evaluate risk factors for a graft rupture.

A total of 111 patients with a mean follow-up of 43.8 ± 17.6 months (range, 24-89 months) were included in the study; 40 patients underwent isolated ACLR, and 71 underwent ACLR + LET. The addition of LET to ACLR was associated with a significantly lower graft rupture rate compared with isolated ACLR (0.0% vs 15.0%, respectively; odds ratio, 15.91 [95% CI, 1.81-139.44]; P = .012). It was also associated with significantly better knee stability (pivot-shift grade 3: 0.0% vs 11.4%, respectively; P = .021) (side-to-side anteroposterior laxity difference >5 mm: 0.0% vs 17.1%, respectively; P = .003) and Tegner activity scores (7 vs 6, respectively; P = .010). There were no significant differences between the groups regarding the Patient Acceptable Symptom State for the patient-reported outcome measures, nor for any of the other outcome measures evaluated, and no differences in the rate of non–graft rupture related reoperations or complications. The ACLR + LET group exceeded the minimal clinically important difference with respect to the Tegner activity scale.

In a retrospective comparative cohort study of adolescents, combined ACLR and LET was associated with a significantly lower graft rupture rate and no difference in non–graft rupture related reoperations or complications compared with isolated ACLR.

Technical innovation has led to the renaissance of anterior cruciate ligament (ACL) repair in the past decade.

The present study aimed to compare instrumented knee joint laxity and patient-reported outcomes (PROs) after ACL repair with those after primary ACL reconstruction for acute isolated ACL tears. It was hypothesized that ACL repair would lead to comparable knee joint stability and PROs at 5 years postoperatively in comparison with ACL reconstruction.

Randomized controlled trial; Level of evidence, 1.

A total of 85 patients with acute ACL tears were randomized to undergo either ACL repair using dynamic intraligamentary stabilization (DIS) or primary ACL reconstruction with a semitendinosus tendon autograft. The primary outcome was the side-to-side difference in anterior tibial translation (ΔATT) assessed by Rolimeter testing at 5 years postoperatively. Follow-up examinations were performed at 1, 2, and 5 years. PROs were assessed using the Tegner activity scale, the International Knee Documentation Committee (IKDC) subjective score, and the Lysholm score. Furthermore, the rates of recurrent instability, other complications, and revision surgery were recorded. A power analysis was performed a priori, and the Friedman test, Mann-Whitney U test, and Bonferroni correction were applied for statistical comparisons with significance set at P < .05.

The mean age at inclusion was 28.3 ± 11.5 years in the ACL repair group and 27.1 ± 11.5 years in the ACL reconstruction group. At 5 years postoperatively, a total of 64 patients (ACL repair: n = 34 of 43 [79%]; ACL reconstruction: n = 30 of 42 [71%]) were available for follow-up. At 5 years, ΔATT was 1.7 ± 1.6 mm in the ACL repair group and 1.4 ± 1.3 mm in the ACL reconstruction group (P = .334). Preinjury PROs were restored as soon as 1 year after surgery and plateaued until 2 and 5 years postoperatively in both groups. At the 5-year follow-up, the mean Lysholm score was 97.0 ± 5.4 versus 94.5 ± 5.5 (P = .322), respectively, and the mean IKDC subjective score was 94.1 ± 9.9 versus 89.9 ± 7.8 (P = .047), respectively, in the ACL repair group versus ACL reconstruction group. At 5 years postoperatively, 12 patients in the ACL repair group (35%; age <25 years: n = 10/12; Tegner score ≥7: n = 10/12) had recurrent instability, of whom 10 underwent single-stage revision ACL reconstruction. In the ACL reconstruction group, there were 6 patients with recurrent instability (20%; age <25 years: n = 6/6; Tegner score ≥7: n = 5/6); however, in 5 patients, staged revision was required. Differences between both groups regarding recurrent instability (P = .09) or ACL revision surgery (P = .118) were not statistically significant. Recurrent instability was associated with age <25 years and Tegner score >7 in both groups.

At 5 years after ACL repair with DIS, instrumented knee joint laxity and PROs were comparable with those after ACL reconstruction. Although no significant difference was found between repair and reconstruction, a critical appraisal of the rates of recurrent instability (35% vs 20%, respectively) and revision surgery (38% vs 27%, respectively) is needed. Young age and a high preinjury activity level were the main risk factors for recurrent instability in both groups. However, single-stage revision ACL reconstruction was possible in each case in the ACL repair group. Although ACL reconstruction remains the gold standard in the treatment of ACL tears, the present study supports the use of ACL repair with DIS as a feasible option to treat acute ACL tears in patients aged ≥25 years with low to moderate activity levels (Tegner score <7).

DRKS00015466 (German Clinical Trials Register).

Biomechanical cadaveric studies have shown that Kaplan fibers (KFs) of the iliotibial band play a role in controlling anterolateral rotatory knee laxity in anterior cruciate ligament (ACL) injury. However, in the clinical setting, the contribution of injury to KFs on anterolateral rotatory laxity remains unclear.

To use magnetic resonance imaging (MRI) scans to detect concomitant KF injury in ACL-injured knees and to then examine the effect of KF injury on anterolateral rotatory laxity as measured by the pivot-shift test in a clinical setting.

Cross-sectional study; Level of evidence, 3.

The study enrolled 91 patients with primary ACL tears (mean age 25 ± 11 years; 46 male and 45 female) whose MRI was conducted within 90 days after injury. KF injury was assessed by MRI according to previously reported criteria, and the patients were allocated to a KF injury group and a no–KF injury group. At the time of ACL reconstruction, the pivot-shift test was performed with the patient under anesthesia and quantitatively evaluated by tibial acceleration using an electromagnetic measurement system. Manual grading of the pivot-shift test was assessed according to guidelines of the International Knee Documentation Committee. The data were statistically compared between the 2 groups using Mann-Whitney U test and Fisher exact test (P < .05).

KFs were identified in 85 patients (93.4%), and KF injury was detected in 20 of the 85 patients (23.5%). No significant differences were observed between the KF injury group (n = 20) and the no–KF injury group (n = 65) in demographic characteristics, the period from injury to MRI (8.0 ± 14.0 days vs 8.9 ± 12.1 days, respectively), the rate of meniscal injury (50.0% vs 53.8%), or the rate of anterolateral ligament injury (45.0% vs 44.6%). Regarding the pivot-shift test, no significant differences were observed in tibial acceleration (1.2 m/s² [interquartile range, 0.5-2.1 m/s²] vs 1.0 m/s² [interquartile range, 0.6-1.7 m/s²], respectively) or manual grading between the 2 groups.

Concomitant KF injury did not significantly affect the pivot-shift phenomenon in acute ACL-injured knees. The findings suggest that the contribution of KF injury to anterolateral rotatory knee laxity may be limited in the clinical setting.

There is a lack of consensus about whether stable ramp lesions associated with anterior cruciate ligament (ACL) injuries need to be repaired.

The purpose of this study was to evaluate how many stable ramp lesions left in situ during ACL reconstruction (ACLR) have subsequently failed after >20 years of follow-up. We hypothesized that ACL-reconstructed knees with ramp lesions left in situ without repair have a high risk of meniscal failure over the long term.

Case series; Level of evidence, 4.

All patients who underwent arthroscopic ACLR by a single experienced surgeon between January 1998 and December 2000 were evaluated retrospectively. Included were all cases of longitudinal tears in the meniscocapsular junction or the red zone of the posterior horn of the medial meniscus that were left in situ and identified through the anterior portals. Successful anterior probing confirmed a meniscal tear of the posterior segment. A lesion was considered stable if it was ≤2 cm and did not extend beyond the lower pole of the femoral condyle. The following data were collected preoperatively and at the last follow-up: demographics, time to surgery, side-to-side laxity, pivot shift, Lysholm score, subjective International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, Tegner activity scale, and meniscal failure rate. We defined 2 groups based on our findings: medial meniscal failure versus no medial meniscal failure.

A total of 716 knees underwent primary ACLR during this period. The 39 (5.4%) stable unrepaired ramp lesions identified were included in the case series. Mean ± standard deviation follow-up was 262.1 ± 10.5 months. Eleven patients (28%) were lost to follow-up. Of the remaining patients, 8 (28.6%) had a medial meniscal failure, of which 6 (21.4%) were bucket-handle tears. The average time elapsed before complications was 87.8 ± 52 months (range, 6-156 months). The medial meniscal survival rate was 93% at 5 years, 75% at 10 years, and 71% at 15 and 20 years. The failure event mainly happened between 96 and 120 months (8 and 10 years) after ACLR. No risk factors for failure were found, but some trends appeared, such as older age, higher body mass index, and preoperative rotational instability. All postoperative scores were significantly improved at the last follow-up (P < .0001); 16 patients (57%) returned to their sport of choice.

With nearly one-third of patients developing meniscal complications, including a large share of bucket-handle tears and mostly occurring 8 years after the ACLR, it may not be wise to leave stable ramp lesions unrepaired.

Despite knee extensor and flexor strength reportedly being associated with injury risk, including rupture of the anterior cruciate ligament in girls, there is limited evidence for the longitudinal changes in lower extremity strength.

To investigate the sex-specific relationship with longitudinal changes of knee extensor and flexor strength associated with maturation.

Cohort study; Level of evidence, 2.

Adolescent boys and girls (N = 257; 208 adolsecent girls) participating in high school basketball, volleyball, and soccer were assessed longitudinally in at least 2 different pubertal stages. Pubertal status (prepubertal, pubertal, and postpubertal) was determined with the modified Pubertal Maturation Observation Scale questionnaire. After a warm-up of 5 submaximal repetitions, participants were tested for concentric peak isokinetic strength for knee extension and flexion at 300 deg/s over 10 repetitions and normalized to body weight. Linear mixed models were used to test for the effect of pubertal stage, sex, and their interaction.

Significant interactions were identified that indicated different maturational trajectories for knee muscle strength for adolescent boys and girls, particularly between prepubertal and pubertal stages, in which boys demonstrated greater mass normalized knee extensor increases than girls (right, +12% vs +5%; left, +13% vs +7%; P < .001). For knee flexors, boys demonstrated increased strength, while girls demonstrated decreased relative knee flexor strength (right, +4% vs −1%, P = .03; left, +3 vs −3%, P = .009).

The findings of this study support a differential effect of sex and maturation on important knee strength outcomes that may have implications for knee injury reduction, particularly in adolescent girls as they mature.

Early tensile loading improves material properties of healing Achilles tendon ruptures in animal models and in surgically treated human ruptures. However, the effect of such rehabilitation in patients who are nonsurgically treated remains unknown.

In nonsurgically treated Achilles tendon ruptures, early tensile loading would lead to higher elastic modulus 19 weeks after the injury compared with controls.

Randomized controlled trial; Level of evidence, 2.

Between October 2015 and November 2018, a total of 40 nonsurgically treated patients with acute Achilles tendon rupture were randomized to an early tensile loading (loaded group) or control group. Tantalum bead markers were inserted percutaneously into the tendon stumps 2 weeks after the injury to allow high-precision measurements of callus deformation under mechanical testing. The loaded group used a training pedal twice daily to produce a gradual increase in tensile load during the following 5 weeks. Both groups were allowed full weightbearing in an ankle orthosis and unloaded range of motion exercises. Patients were followed clinically and via roentgen stereophotogrammetric analysis and computed tomography at 7, 19, and 52 weeks after the injury.

The mean ± standard deviation elastic modulus at 19 weeks was 95.6 ± 38.2 MPa in the loaded group and 108 ± 45.2 MPa in controls (P = .37). The elastic modulus increased in both groups, although it was lower in the loaded group at all time points. Tendon cross-sectional area increased from 7 weeks to 19 weeks, from 231 ± 99.5 to 388 ± 142 mm² in the loaded group and from 188 ± 65.4 to 335 ± 87.2 mm² in controls (P < .001 for the effect of time). Cross-sectional area for the loaded group versus controls at 52 weeks was 302 ± 62.4 mm² versus 252 ± 49.2 mm², respectively (P = .03). Gap elongation was 7.35 ± 13.9 mm in the loaded group versus 2.86 ± 5.52 mm in controls (P = .27).

Early tensile loading in nonsurgically treated Achilles tendon ruptures did not lead to higher elastic modulus in the healing tendon but altered the structural properties of the tendon via an increased tendon thickness.

NCT0280575 (ClinicalTrials.gov identifier).

The preferred method of fixation and surgical treatment for ligamentous Lisfranc injuries is controversial. Transarticular screws, bridge plating, fusion, and flexible fixation have been described, yet none have demonstrated superiority. Furthermore, screw fixation and plating often require secondary surgery to remove implants, leading surgeons to seek alternative fixation methods.

To compare transarticular screws and a fiber tape construct under a spectrum of biomechanical loads by evaluating the diastasis at 3 joints in the Lisfranc complex.

Controlled laboratory study.

Eight matched pairs of fresh, previously frozen lower extremity cadaveric specimens were fixed with either 2 cannulated transarticular crossed screws or a fiber tape construct with a supplemental intercuneiform limb. The diastasis between bones was measured at 3 midfoot joints in the Lisfranc complex: the Lisfranc articulation, the second tarsometatarsal joint, and the intercuneiform joint. Measurements were obtained for the preinjured, injured, and fixation conditions under static loading at 50% donor body weight. Specimens then underwent cyclic loading performed at 1 Hz and 100 cycles, based on 100-N stepwise increases in ground-reaction force from 100 to 2000 N, to simulate postoperative loading from the partial weightbearing stage to high-energy activities. Failure of fixation was defined as diastasis ≥2 mm at the Lisfranc articulation (second metatarsal–medial cuneiform joint).

There were no significant differences in diastasis detected at the Lisfranc articulation or the intercuneiform joint throughout all loading cycles between groups. All specimens endured loading up to 50% body weight + 1400 N. Up to and including this stage, there were 2 failures in the cannulated transarticular crossed-screw group and none in the fiber tape group.

The fiber tape construct with a supplemental intercuneiform limb, which does not require later removal, may provide comparable biomechanical stability to cannulated transarticular crossed screws, even at higher loads.

Ligamentous Lisfranc injuries are common among athletes. Therefore, biomechanical evaluations are necessary to determine stable constructs that can limit the time to return to play. This study compares the biomechanical stability of 2 methods of fixation for ligamentous injury through a wide spectrum of loading, including those experienced by athletes.

Patient Acceptable Symptom State (PASS), minimal clinically important difference (MCID), and substantial clinical benefit (SCB) have rarely been assessed after arthroscopic superior capsular reconstruction (ASCR) with fascia lata autograft.

(1) To investigate PASS, MCID, and SCB values for pain visual analog scale (pVAS), American Shoulder and Elbow Surgeons (ASES) score, Constant score, and Single Assessment Numeric Evaluation (SANE) after ASCR with fascia lata autograft, (2) to investigate factors for achieving PASS, MCID, and SCB.

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

We retrospectively collected data from patients who underwent ASCR between June 2013 and October 2020. A total of 88 patients were included, and anchor questions for deriving PASS, MCID, and SCB values were applied at a minimum 1-year follow-up postoperatively. PASS, MCID, and SCB were derived using sensitivity- and specificity-based approaches. Univariable and multivariable logistic regression analyses were performed to determine factors for achieving PASS, MCID, and SCB.

Based on receiver operating characteristic curves, all 4 scores had acceptable area under the curve values (>0.7) for PASS, MCID, and SCB values. The PASS, MCID, and SCB values were 1.5, 2.5, and 4.5 for pVAS; 81.0, 19.0, and 27.5 for the ASES score; 60.5, −0.5, and 5.5 for the Constant score; and 75.0, 27.5, and 32.5 for SANE, respectively. Poor preoperative scores were related to significantly higher odds ratios (ORs) for achieving MCID and SCB. Wide acromiohumeral distance and dominant side were related to higher ORs for achieving PASS for the ASES score, and subscapularis tear was related to lower ORs for achieving PASS for pVAS and SCB for the Constant score.

Reliable PASS, MCID, and SCB values were achieved for at least 1 year after ASCR surgery. Poor preoperative score, wide acromiohumeral distance, and dominant side all demonstrated higher ORs for at least one value, but a subscapularis tear demonstrated lower ORs for achieving PASS for pVAS and SCB for the Constant score.

Literature is scarce regarding the influence of psychological readiness on return to sports after shoulder instability surgery.

To evaluate the predictive ability of the Shoulder Instability–Return to Sport after Injury (SIRSI) score in measuring the effect of psychological readiness on return to sports and to compare it between athletes who returned to sports and athletes who did not return to sports.

Cohort study; Level of evidence, 2.

A prospective analysis was performed of patients who underwent an arthroscopic Bankart repair or a Latarjet procedure between January 2019 and September 2020. Psychological readiness to return to play was evaluated using the SIRSI instrument. Preoperative and postoperative functional outcomes were measured by the Rowe, Athletic Shoulder Outcome Scoring System, and Western Ontario Shoulder Instability Index scores. The predictive validity of the SIRSI was assessed by the use of receiver operating characteristic (ROC) curve statistics. The Youden index was calculated and used to determine a SIRSI score cutoff point that best discriminated psychological readiness to return to sports. A logistic regression analysis was performed to evaluate the effect of psychological readiness on return to sports and return to preinjury sports level.

A total of 104 patients were included in this study. Overall, 79% returned to sports. The SIRSI had excellent predictive ability for return-to-sport outcomes (return to sports: area under ROC curve, 0.87 [95% CI, 0.80-0.93]; return to preinjury sports level: area under ROC curve, 0.96; [95% CI, 0.8-0.9]). A cutoff level of ≥55 was used to determine whether an athlete was psychologically ready to return to sports and to return to preinjury sports level (Youden index, 0.7 and 0.9, respectively). Of those who returned to sports, 76.8% were psychologically ready to return to play, with a median SIRSI score of 65 (interquartile range, 57-80). In comparison, in the group that did not return to sports, only 4.5% achieved psychological readiness with a median SIRSI score of 38.5 (interquartile range, 35-41) (P < .001). Regression analysis for the effect of SIRSI score on return to sports was performed. For every 10-point increase in the SIRSI score, the odds of returning to sports increased by 2.9 times. Moreover, those who did not achieve their preinjury sports level showed poorer psychological readiness to return to play and SIRSI score results.

The SIRSI was a useful tool for predicting whether patients were psychologically ready to return to sports after glenohumeral stabilization surgery. Patients who returned to sports and those who returned to their preinjury sports level were significantly more psychologically ready than those who did not return. Therefore, we believe that the SIRSI score should be considered along with other criteria that are used to decide whether the patient is ready to return to sports.

The arthroscopic bone block procedure according to Latarjet remains a controversial subject, and few comparative studies have demonstrated the benefit of arthroscopy over open surgery.

The objective of this study was to compare both procedures by analyzing the short-term clinical results. The hypothesis was that the arthroscopic procedure is superior to the standard open procedure.

Cohort study; Level of evidence, 3.

This was a retrospective comparative study. Patients treated for chronic anterior instability by arthroscopic Latarjet with double cortical buttons (group A) or open Latarjet with screws (group O) with a minimum follow-up of 12 months were included. Intraoperative (duration, complications) and postoperative (complications, pain, mobility, functional scores, resumption of sport, Patient and Observer Scar Assessment Scale scar aesthetics, satisfaction) data were compared.

In total, 50 patients were included (n = 24 in group A, n = 26 in group O). Operating time was longer in group A (103 vs 61 min; P = .001). The average number of days on analgesics was higher in group A (8.9 vs 5.3 days; P = .04). The complication rate was similar for the 2 groups (12.5% vs 27%; P = .46). At 3 months, the loss of external rotation was greater in group A (–33° vs −18°; P = .01), and resumption of sports was less frequent (11% vs 48%; P = .01). At 12 months, the average scores were excellent, with no significants differences between the 2 groups: Walch-Duplay average, 90 points; Rowe, 94 points; Subjective Shoulder Value (SSV), 92.5%; sport SSV, 85%; and Patient and Observer Scar Assessment Scale score, 17.2 points.

Over the short term, this comparative study did not prove the superiority of the cortical-button arthroscopic Latarjet procedure over the open Latarjet procedure. A delay in the resumption of sports, longer time to recover range of motion, and no benefit regarding postoperative pain or the aesthetic aspect of the scar were observed in this study with the arthroscopic procedure.

Glenoid restoration techniques to address glenohumeral instability–induced anterior and posterior glenoid bone loss (AGBL and PGBL) often require reconstruction, but best-fit bone block (BFBB) modeling has not been developed.

To provide glenoid bony reconstruction models for anterior and posterior instability of the shoulder using a bone loss instability cohort with high-fidelity 3-dimensional (3D) imaging.

Cross-sectional study; Level of evidence, 3.

We reviewed consecutive patients indicated for operative stabilization who had posterior glenohumeral instability and suspected GBL who underwent 2-dimensional (2D) computed tomography (CT). Patients were matched by sex, laterality, and age to patients who underwent operative stabilization of anterior glenohumeral instability. Mimics software was used to convert all 2D CT scans into 3D models of the scapula. A BFBB model was designed to digitally reconstruct GBL and was used to predict the amount, anatomic configuration, and fixation configuration of bony reconstruction required in AGBL and PGBL.

The study included 30 patients with posterior instability and 30 patients with anterior instability; the participants’ mean ± SD age was 28.8 ± 8.15 years (range, 16.0-51.0 years). Mean surface area of AGBL was 24.9% ± 7.7% (range, 14.7%-39.1%). Mean BFBB dimensions to reconstruct the anterior glenoid were determined to be a superior-inferior length of 23.9 ± 4.2 mm, anterior-posterior width of 6.4 ± 2.4 mm, and height of 1 cm. Mean angle of AGBL bone block interface relative to glenoid to reconstruct the native concavity was 79.4°± 5.9°. For PGBL, the mean surface area was 9.2% ± 5.6% (range, 3.0%-26.3%). Mean BFBB dimensions to reconstruct the posterior glenoid were a superior-inferior length of 21.9 ± 3.4 mm, width of 4.5 ± 2.3 mm, and height of 1 cm. The mean angle of PGBL bone block interface relative to the glenoid to reconstruct the native concavity was 38.6°± 14.3°. Orientation relative to the vertical glenoid axis was 77.2°± 13.8° in anterior reconstructions versus 105.9°± 10.9° in posterior reconstructions.

Patients with anterior instability required a more rectangular BFBB with a bone block–glenoid interface angle of 79°, whereas patients with posterior instability required a more trapezoidal, obtusely oriented BFBB with a bone block–glenoid interface angle of 39°. BFBBs for either AGBL or PGBL can be effectively designed, and their size and/or shape can be predicted based on approximate percentage of GBL.

Platelet-rich fibrin (PRF) is a second-generation platelet concentrate. Although peripheral blood–derived PRF (P-PRF) is commonly applied in biological augmentation, there is no report about the therapeutic effect of bone marrow–derived PRF (BM-PRF) for degenerative rotator cuff tears (RCTs).

To examine the effects of platelet-rich plasma (PRP), P-PRF, and BM-PRF during rotator cuff repair (RCR) in degenerative RCTs in rabbits. We hypothesized that BM-PRF would accelerate the bone-tendon healing after RCR.

Controlled laboratory study.

Degenerative RCT models were created 2 weeks before beginning the study, and 68 juvenile rabbits were divided into 4 groups: the control, PRP, P-PRF, and BM-PRF groups. RCR without augmentation was done in the control group. PRP was prepared by centrifuging peripheral blood twice using a plastic tube. P-PRF and BM-PRF were prepared by centrifuging peripheral blood and bone marrow, respectively, using a glass tube. Rabbits from PRP, P-PRF, and BM-PRF groups were administered the augmentation in a similar fashion for RCR, between the rotator cuff and the footprint of the humerus. At 4, 8, and 12 weeks, rabbits were euthanized and histologically assessed using hematoxylin and eosin staining, Alcian blue staining, and immunohistochemical staining for type I and III collagen. The sections were also evaluated with immunofluorescence staining of vascular endothelial growth factor (VEGF) at 4 weeks.

The continuity was significantly better in the BM-PRF group at 4 weeks (P < .05). Immunofluorescence staining demonstrated that VEGF-positive stained cells were significantly greater in the BM-PRF group than in the control group (P < .01). The modified tendon maturing score was significantly greater in the BM-PRF group than in the control and PRP groups at 12 weeks (P < .05). There was no significant difference in the modified tendon maturing score of the P-PRF group compared with the control group.

The rabbit model of degenerative RCTs demonstrated that RCR combined with BM-PRF enhanced tendon-bone continuity and increased the VEGF-positive cells at 4 weeks and obtained preferable tendon-bone maturation at 12 weeks.

RCR augmented with BM-PRF has the potential to improve clinical outcomes for RCTs.

Zoledronic acid improves bone microarchitecture and biomechanical properties after chronic rotator cuff repair (RCR) in rats. Besides the positive effects of zoledronic acid on bone mineral density and bone microarchitecture, bisphosphonates have positive effects on skeletal muscle function.

The purposes of this study were to (1) longitudinally evaluate circulating bone- and muscle-specific serum micro-ribonucleic acids (miRNAs) and (2) investigate supraspinatus muscle tissue after tenotomy and delayed RCR in a rat model. It was hypothesized that zoledronic acid would improve muscle regeneration after chronic RCR in rats.

Controlled laboratory study.

A total of 34 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy (time point 1) with delayed transosseous RCR after 3 weeks (time point 2). All rats were sacrificed 8 weeks after RCR (time point 3). Animals were randomly assigned to 2 groups. One day after RCR, the control group was given 1 mL of subcutaneous saline solution, and the intervention group was treated with a subcutaneous single-dose of 100 µg/kg body weight of zoledronic acid. All 34 study animals underwent miRNA analysis at all 3 time points. In 4 animals of each group, histological analyses as well as gene expression analyses were conducted.

Circulating miRNAs showed significantly different expressions between both study groups. In the control group, a significant downregulation was observed for muscle-specific miR-1-3p (P = .004), miR-133a-3p (P < .001), and miR-133b (P < .001). Histological analyses showed significantly higher rates of regenerating myofibers on the operated side (left) of both study groups compared with the nonoperated side (right; P = .002). On the nonoperated side, significantly higher rates of regenerating myofibers were observed in the intervention group compared with the control group (P = .031). The myofiber cross-sectional area revealed significantly smaller myofibers on both sides within the intervention group compared with both sides of the control group (P < .001). Within the intervention group, significantly higher expression levels of muscle development/regeneration marker genes embryonal Myosin heavy chain (P = .017) and neonatal Myosin heavy chain (P = .016) were observed on the nonoperated side compared with the operated side.

An adjuvant single-dose of zoledronic acid after RCR in a chronic defect model in rats led to significant differences in bone- and muscle-specific miRNA levels. Therefore, miR-1-3p, miR-133a-3p, and miR-133b might be used as biomarkers for muscle regeneration after RCR.

Adjuvant treatment with zoledronic acid may improve muscle regeneration after chronic RCR in humans, thus counteracting fatty muscle infiltration and atrophy.

Ulnar collateral ligament (UCL) surgery continues to demonstrate excellent clinical outcomes and a high return-to-play (RTP) rate with a low complication rate. Recent studies have demonstrated similar clinical outcomes for baseball players who have undergone either UCL reconstruction or UCL repair. In comparison, few studies have assessed the clinical outcomes of UCL surgery for nonthrowing athletes.

The primary objective of this study is to provide clinical outcomes of UCL surgery performed in nonthrowing athletes at a single institution with a minimum 2-year follow-up. Our hypothesis was that these patients would have similar clinical outcomes, complication rates, and RTP rates when compared with throwing athletes.

Case series; Level of evidence, 4.

From our longitudinal elbow registry, 40 nonthrowing athletes were identified who underwent UCL surgery (repair or reconstruction) between 2011 and 2019. Participant characteristics were recorded: age, sex, laterality, arm dominance, sport, level of competition, and type of surgery (UCL repair or reconstruction). Outcomes included RTP rate and average time, American Shoulder and Elbow Surgeons (ASES) scores, and complications.

From the 40 patients eligible for inclusion in this study with a minimum 2-year follow-up, 37 (93%) were successfully contacted: 16 male (43%) and 21 female (57%). Mean ± standard deviation age at the time of surgery was 18.0 ± 3.7 years. From the 37 technical procedures, 28 (76%) were UCL repairs and 9 (24%) were UCL reconstructions. For these patients, 15 (41%) had partial tears, 20 (54%) had complete tears, 1 (3%) had a medial epicondyle avulsion, and 1 (3%) had an unspecified pathology. Sports included football (n = 11), gymnastics (11), cheerleading (7), wrestling (4), volleyball (2), basketball (1), and acrobatics (1). Quarterbacks were excluded from the football patients, as quarterbacks are throwing athletes. Level of competition included high school (n = 26), college (8), professional (2), and youth sports (1). The RTP rate was 93% (26/28) at a mean 7.4 months for UCL repair and 100% (9/9) at a mean 10.0 months for UCL reconstruction. Mean ASES scores were 94.4 and 98.7 for UCL repair and reconstruction, respectively. Complications were low, with 2 patients in the UCL repair group requiring ulnar nerve transposition for ulnar nerve paresthesia.

In nonthrowing athletes, patients undergoing UCL repair and UCL reconstruction show favorable outcomes at minimum 2-year follow-up. RTP and clinical outcomes are consistent with previous studies in baseball players as well as a parallel ongoing study conducted on non–baseball throwing athletes.

Biomechanical efficiency, defined as fastball velocity per unit of normalized elbow varus torque, is a relatively new metric applied to improving the performance and health of baseball pitching.

The purpose of this work was to evaluate kinematic parameters influencing biomechanical efficiency among professional and collegiate pitchers. Kinematic differences were compared between pitchers of high and low biomechanical efficiency. We hypothesized that professional pitchers would have greater biomechanical efficiency than collegiate pitchers.

Descriptive laboratory study.

A deidentified biomechanical database of 545 pitchers (447 professional, 98 collegiate) was analyzed. A multivariate linear regression model was used to evaluate significant findings a priori with α = .05. Additionally, biomechanical differences were identified between competition levels and between high and low biomechanical efficiency groups using Mann-Whitney U test (α = .05).

Competition level and 11 (of 21) kinematic variables explained 27% of the variance in biomechanical efficiency, with most of the predictors being throwing arm kinematics (elbow flexion at stride foot contact [SFC]: β, −1.47; SE, 0.26; shoulder abduction at SFC: β, −1.78; SE, 0.39; shoulder external rotation at SFC: β, 0.60; SE, 0.22; maximum external rotation [MER] angle: β, 1.82; SE, 0.42; shoulder horizontal adduction at MER: β, −3.42; SE, 0.71) (all P≤ .05). Professional pitchers had greater biomechanical efficiency than collegiate pitchers (711.0 ± 101.0 vs 657.0 ± 99.3, respectively; P < .001; d = 0.53). Compared with the low-efficiency group, the high-efficiency group had significantly lower normalized elbow varus torque with greater weight and height (high: 0.047 ± 0.004 %wt*ht vs. low: 0.063 ± 0.006 %wt*ht, P <.001; d = 3.20). At the instant of SFC, the high-efficiency group demonstrated greater shoulder external rotation and less elbow flexion, shoulder abduction, and pelvic rotation. The high-efficiency group also had greater MER and less shoulder horizontal adduction at MER, trunk side tilt at ball release, and knee excursion from foot contact to ball release.

Professional pitchers had greater biomechanical efficiency than collegiate pitchers. Biomechanical efficiency was also affected by 11 kinematic variables identified in this study. Pitchers with higher efficiency had distinct differences in arm position, trunk side tilt, and lead-knee extension range of motion in the delivery. Thus, pitchers and baseball organizations should focus on these factors to lower normalized elbow varus torque relative to ball velocity.

Bone stress injuries (BSIs) are common sports injuries that occur because of an imbalance between microdamage accumulation and removal through bone remodeling. The underlying bone phenotype has been assumed to be a contributing factor. However, the bone microarchitecture of athletes with BSI is not well characterized, and no study has investigated whether impaired bone microarchitecture is associated with bone composition or anatomic site of injury.

This cross-sectional study characterizes the bone microarchitecture at distal radial and tibial reference locations in athletes with BSI. Based on previous dual-energy X-ray absorptiometry (DXA) findings, the aim was to compare anatomic injury sites, hypothesizing that athletes with BSIs in bones with greater trabecular composition show impaired bone microarchitecture parameters compared with those with BSIs in bones with greater cortical composition.

Cohort study; Level of evidence, 3.

Athletes who had presented to our outpatient clinic because of a high-grade BSI (ie, stress fracture) were retrospectively included. Blood and urine samples were collected. Areal bone mineral density (aBMD) was assessed by DXA at the lumbar spine and both hips. Bone microarchitecture was analyzed by high-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and tibia. HR-pQCT parameters were expressed in relation to available sex-, age-, and device-adjusted reference values and compared with a cohort of 53 age- and sex-matched controls.

In total, 53 athletes had a BSI of the foot (n = 20), tibia/fibula (n = 18), pelvis (n = 9), femur (n = 5), or sternum (n = 1). Based on DXA measurements, a Z-score of −1.0 or lower was found in 32 of 53 (60.4%) of the athletes, of whom 16 of 53 (30.2%) had a Z score −2.0 or lower. While an impairment of cortical area (P = .034 and P = .001) and thickness (P = .029 and P < .001) was detected at the distal radius and tibia in the BSI cohort compared with controls, no differences in BMD or bone microarchitecture were observed between anatomic injury sites. Furthermore, no difference was revealed when BSIs were grouped into cortical- and trabecular-rich sites.

Reduced aBMD and impaired cortical bone microarchitecture were present in a considerable number of athletes with BSI. Neither aBMD nor bone microarchitecture was related to the injury site, highlighting the multifactorial etiology of BSI.

Owing to the disappointing regenerative ability of osteochondral tissue, without treatment an osteochondral defect would progress to osteoarthritis. This situation motivates the need for new strategies to enhance the regeneration of osteochondral defects.

To develop a tissue-engineering scaffold by tethering bone morphogenetic protein 2 (BMP2) and transforming growth factor beta 3 (TGFβ3) in a layer-specific manner on a slotted decellularized osteochondral matrix (SDOM) and to evaluate the efficacy of this scaffold for osteochondral regeneration.

Controlled laboratory study.

Normal osteochondral tissue from the rabbit patellofemoral groove was sectioned into a slot shape and decellularized for fabricating an SDOM. The collagen-binding domain (CBD) was fused into the N-terminus of BMP2 or TGFβ3 to synthesize 2 recombinant growth factors (GFs) (CBD-BMP2 or CBD-TGFβ3), which were tethered to the bone layer and cartilage layer, respectively, of the SDOM to prepare a tissue-engineering scaffold (namely, CBD-GFs/SDOM). After examining the influence of the CBD-GFs/SDOM on the viability and layer-specific differentiation of bone marrow mesenchymal stem cells in vitro, we determined the regeneration potential of the CBD-GFs/SDOM on osteochondral regeneration in a rabbit model. A total of 72 New Zealand White rabbits with a cylindrical osteochondral defect in the patellofemoral groove were randomly assigned to 3 groups: defect only (control [CTL] group), defect patched with an SDOM (SDOM group), and defect patched with the CBD-GFs/SDOM (CBD-GFs/SDOM group). At 6 or 12 weeks postoperatively, the rabbits were euthanized to harvest the knee joint, which was then evaluated via gross observation, micro–computed tomography, histological staining, and mechanical testing.

In vitro, the CBD-GFs/SDOM was noncytotoxic, showed high biomimetics with normal osteochondral tissue, was suitable for cell adhesion and growth, and had good layer-specific ability in inducing stem cell differentiation. Macroscopic images showed that the CBD-GFs/SDOM group had significantly better osteochondral regeneration than the CTL and SDOM groups had. Micro–computed tomography demonstrated that much more bony tissue was formed at the defect sites in the CBD-GFs/SDOM group compared with the defect sites in the CTL or SDOM group. Histological analysis showed that the CBD-GFs/SDOM group had a significant enhancement in osteochondral regeneration at 6 and 12 weeks postoperatively in comparison with the CTL or SDOM group. At 12 weeks postoperatively, the mechanical properties of reparative tissue were significantly better in the CBD-GFs/SDOM group than in the other groups.

The CBD-GFs/SDOM is a promising scaffold for osteochondral regeneration.

The findings of this study indicated that the CBD-GFs/SDOM is an excellent candidate for reconstructing osteochondral defects, which may be translated for clinical use in the future.

The prevalence of unreported concussions is high, and undiagnosed concussions can lead to worse postconcussion outcomes. It is not clear how those with a history of undiagnosed concussion perform on subsequent standard concussion baseline assessments.

To determine if previous concussion diagnosis status was associated with outcomes on the standard baseline concussion assessment battery.

Cross-sectional study; Level of evidence, 3.

Concussion Assessment, Research, and Education (CARE) Consortium participants (N = 29,934) self-reported concussion history with diagnosis status and completed standard baseline concussion assessments, including assessments for symptoms, mental status, balance, and neurocognition. Multiple linear regression models were used to estimate mean differences and 95% CIs among concussion history groups (no concussion history [n = 23,037; 77.0%], all previous concussions diagnosed [n = 5315; 17.8%], ≥1 previous concussions undiagnosed [n = 1582; 5.3%]) at baseline for all outcomes except symptom severity and Brief Symptom Inventory–18 (BSI-18) score, in which negative binomial models were used to calculate incidence rate ratios (IRRs). All models were adjusted for sex, race, ethnicity, sport contact level, and concussion count. Mean differences with 95% CIs excluding 0.00 and at least a small effect size (≥0.20), and those IRRs with 95% CIs excluding 1.00 and at least a small association (IRR, ≥1.10) were considered significant.

The ≥1 previous concussions undiagnosed group reported significantly greater symptom severity scores (IRR, ≥1.38) and BSI-18 (IRR, ≥1.31) scores relative to the no concussion history and all previous concussions diagnosed groups. The ≥1 previous concussions undiagnosed group performed significantly worse on 6 neurocognitive assessments while performing better on only 2 compared with the no concussion history and all previous concussions diagnosed groups. There were no between-group differences on mental status or balance assessments.

An undiagnosed concussion history was associated with worse clinical indicators at future baseline assessments. Individuals reporting ≥1 previous undiagnosed concussions exhibited worse baseline clinical indicators. This may suggest that concussion-related harm may be exacerbated when injuries are not diagnosed.

Femoroacetabular impingement (FAI) is a common pathology in athletes that often requires operative management in the form of hip arthroscopy.

To systematically review the rates and level of return to play (RTP) and the criteria used for RTP after hip arthroscopy for FAI in athletes.

Systematic review; Level of evidence, 4.

A systematic review of the literature, based on the PRISMA guidelines, was performed using PubMed, Embase, and Scopus databases. Studies reporting outcomes after the use of hip arthroscopy for FAI were included. Outcomes analyzed were RTP rate, RTP level, and criteria used for RTP. Statistical analysis was performed using SPSS software.

Our review found 130 studies, which included 14,069 patients (14,517 hips) and had a mean methodological quality of evidence (MQOE) of 40.4 (range, 5-67). The majority of patients were female (53.7%), the mean patient age was 30.4 years (range, 15-47 years), and the mean follow-up was 29.7 months (range, 6-75 months). A total of 81 studies reported RTP rates, with an overall RTP rate of 85.4% over a mean period of 6.6 months. Additionally, 49 studies reported the rate of RTP at preinjury level as 72.6%. Specific RTP criteria were reported in 97 studies (77.2%), with time being the most commonly reported item, which was reported in 80 studies (69.2%). A total of 45 studies (57.9%) advised RTP at 3 to 6 months after hip arthroscopy.

The overall rate of reported RTP was high after hip arthroscopy for FAI. However, more than one-fourth of athletes who returned to sports did not return at their preinjury level. Development of validated rehabilitation criteria for safe return to sports after hip arthroscopy for FAI could potentially improve clinical outcomes while also increasing rates of RTP at preinjury levels.

It is unclear whether the results of osteochondral transplant using autografts or allografts for talar osteochondral defect are equivalent.

A systematic review of the literature was conducted to compare allografts and autografts in terms of patient-reported outcome measures (PROMs), MRI findings, and complications.

Systematic review; Level of evidence, 4.

This study was conducted according to the PRISMA guidelines. The literature search was conducted in February 2021. All studies investigating the outcomes of allograft and/or autograft osteochondral transplant as management for osteochondral defects of the talus were accessed. The outcomes of interest were visual analog scale (VAS) score for pain, American Orthopaedic Foot and Ankle Society (AOFAS) score, and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score. Data concerning the rates of failure and revision surgery were also collected. Continuous data were analyzed using the mean difference (MD), whereas binary data were evaluated with the odds ratio (OR) effect measure.

Data from 40 studies (1174 procedures) with a mean follow-up of 46.5 ± 25 months were retrieved. There was comparability concerning the length of follow-up, male to female ratio, mean age, body mass index, defect size, VAS score, and AOFAS score (P > .1) between the groups at baseline. At the last follow-up, the MOCART (MD, 10.5; P = .04) and AOFAS (MD, 4.8; P = .04) scores were better in the autograft group. The VAS score was similar between the 2 groups (P = .4). At the last follow-up, autografts demonstrated lower rate of revision surgery (OR, 7.2; P < .0001) and failure (OR, 5.1; P < .0001).

Based on the main findings of the present systematic review, talar osteochondral transplant using allografts was associated with higher rates of failure and revision compared with autografts at midterm follow-up.