Hamstring Tendon Autograft Is Associated With Increased Knee Valgus Moment After Anterior Cruciate Ligament Reconstruction: A Biomechanical Analysis.

BACKGROUND: There is limited evidence related to the effects of autograft type on functional performance after anterior cruciate ligament reconstruction (ACLR). PURPOSE/HYPOTHESIS: This study aimed to compare biomechanical outcomes during a drop vertical jump (DVJ) between patients with a hamstring tendon (HT) autograft, quadriceps tendon (QT) autograft with bone block, QT autograft without bone block, and bone-patellar tendon-bone autograft at 6 months postoperatively in an adolescent population. The authors' hypothesized there would be differences in DVJ biomechanics between athletes depending on the type of autograft used. STUDY DESIGN: Controlled laboratory study. METHODS: Patients aged 8 to 18 years who underwent primary ACLR were included for analysis. Kinematic and kinetic data collected during a DVJ using a 3-dimensional computerized marker system were assessed at 6 months after ACLR and compared with the uninjured contralateral limb. RESULTS: A total of 155 participants were included. There were no significant differences in terms of age, sex, or affected leg (P≥ .1973) between groups. The HT group was significantly associated with a larger knee valgus moment at initial contact compared with the QT group (28 × 10-2 vs -35 × 10-2 N·m/kg, respectively; P = .0254) and a significantly larger maximum hip adduction moment compared with the QT with bone block group (30 × 10-2 vs -4 × 10-2 N·m/kg, respectively; P = .0426). Both the QT with bone block (-12 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0265) and QT (-13 × 10-2 vs -3 × 10-2 N·m/kg, respectively; P = .0459) groups demonstrated significantly decreased mean knee extension moments compared with the HT group. CONCLUSION: The findings of this study suggest that utilizing an HT autograft resulted in a significantly increased knee valgus moment at initial contact compared with a QT autograft without bone block at 6 months after ACLR in adolescent patients performing a DVJ. A QT autograft was found to be associated with significantly decreased extensor mechanism function compared with an HT autograft. CLINICAL RELEVANCE: This study adds unique kinematic and kinetic information regarding various ACLR autograft options and highlights the biomechanical deficits that should be taken into consideration in rehabilitation.

Biomechanical Gender Differences in the Uninjured Extremity After Anterior Cruciate Ligament Reconstruction in Adolescent Athletes: A Retrospective Motion Analysis Study.

Introduction Subsequent anterior cruciate ligament (ACL) injury is more common in the pediatric population and encompasses graft failure and subsequent contralateral tears. Females are at a higher risk. The purpose of the present study was to compare the knee valgus angles at initial contact, knee extension moments, anterior and lateral knee joint forces, hip flexion angles, hip adduction moments, and ankle inversion during the drop vertical test in the uninjured extremity between adolescent males and females who had previously undergone an anterior cruciate ligament reconstruction (ACLR). Methods This IRB-approved retrospective chart review included patients aged 8-18 years who were seen at the five to seven month postoperatively following ACL reconstruction. A total of 168 patients met our inclusion criteria (86 girls and 82 boys.) Using three-dimensional motion capture technology (CORTEX software, Motion Analysis Corp., Rohnert Park, CA), data were collected while the subject performed the drop vertical test over floor-mounted force plates (FP-Stairs, AMTI, Watertown, MA) under the direct supervision of a pediatric physical therapist. The Wilcoxon rank sum was used, and p < 0.05 was considered statistically significant. Results Females demonstrated a larger average knee joint extension moment (0.31 vs 0.28 N*m/kg, p = 0.0408), a larger anterior knee joint force at initial contact (3.51 vs. 2.79, N/kg, p = 0.0458), larger average hip flexion angle (41.50° vs. 35.99°, p = 0.0005), a smaller maximum hip adduction moment (0.92 vs. 1.16, N*m/kg, p = 0.0497), and a smaller average ankle inversion angle (5.08° vs. 6.41°, p = 0.03231). No significant differences were found regarding knee abduction angle or lateral knee joint force. Conclusions The biomechanical profile of the contralateral extremity varies significantly between the genders after ACLR. In the uninjured extremity, females may have larger hip flexion angles, smaller hip adduction moments, larger anterior knee joint forces, larger knee extension moments, and smaller ankle inversion angles as compared to males after ACLR. These findings may explain the higher incidence of subsequent contralateral injury in female adolescent athletes. Further work is required to develop a composite score that determines at-risk athletes.

There Is Substantial Variation in Rehabilitation Protocols Following Anterior Cruciate Ligament Reconstruction: A Survey of 46 American Orthopaedic Surgeons.

PURPOSE: To identify the clinical practice preferences of orthopaedic surgeons regarding anterior cruciate ligament reconstruction (ACLR) rehabilitation through a survey of members of the Arthroscopy Association of North American (AANA) and the American Orthopaedic Society for Sports Medicine (AOSSM). METHODS: An online survey was distributed to members of AANA and AOSSM between November 2020 and September 2021. Participants reported on their clinical preferences for ACLR protocol development and patient selection, use of technology in ACLR recovery and rehabilitation, and preferences for advancing through multiple phases of the rehabilitative process. RESULTS: Responses from 46 orthopaedic surgeons were analyzed. Patient-reported outcome measures were not found to be utilized often at various phases of the perioperative period. Thirty-eight (82.6%) participants reported utilization of postoperative bracing. There was no consensus on when participants allow their patients to advance through rehabilitation, but most report waiting 3 to 4 months for advancement to jogging/lateral movement, 6 to 8 months for return to noncontact sport, and 9 months of more for return to unrestricted sport. Many participants utilize functional and strength testing with associated limb symmetry indices to determine patient readiness to return to sport, with 18, 26, and 25 participants reporting use of functional testing and 28, 26, and 27 participants reporting use of strength testing at the return to jogging/lateral movements, noncontact return to sport, and unrestricted return-to-sport phases, respectively. CONCLUSIONS: This study provides an insight into the rehabilitative protocols and modalities utilized for ACLR by orthopaedic surgeons in practice across the United States. There is notably substantial variation in rehabilitative patterns and preferences, particularly with regards to what constitutes criteria for progressing patients through the phases of returning to unrestricted sport. Additionally, our findings show that while many surgeons believe that quantitative assessment technology could be beneficial in decision-making for returning patients to sport, there are still many barriers that stand in the way of its implementation into clinical practice. CLINICAL RELEVANCE: Postoperative rehabilitative protocols after ACLR vary by surgeon.

Femoral-Sided Avulsion Fracture of the Anterior Cruciate Ligament in a Skeletally Immature Patient: A Case Report.

CASE: A 10-year-old boy presented to the clinic with sharp left knee pain after sustaining an injury while hiking. The patient was unable to bear weight. Physical examination demonstrated a moderate effusion and lateral joint line tenderness. Imaging studies revealed a femoral-sided avulsion of the anterior cruciate ligament. Arthroscopic suture fixation of the avulsed fragment resulted in good radiographic and clinical results at the 13-month follow-up. CONCLUSION: Physeal-sparing suture-fixation of femoral-sided anterior cruciate ligament avulsion injuries can be performed using an all-arthroscopic approach and may be a viable treatment option.

Shoulder Synovial Chondromatosis in an Adolescent Athlete: A Case Report.

Introduction: Synovial chondromatosis refers to a benign proliferative disease of the synovium. Reports in children are rare and reports involving the pediatric shoulder are even more rare. In this review of the literature and case report, we provide a summary of all published cases in children and a report of a case of shoulder synovial chondromatosis in an adolescent female athlete. Case Presentation: A 15-year-old female cheerleader presented to the clinic with gradual onset right shoulder pain with a severity of 5/10. On physician examination, the patient had tenderness over the proximal humerus, limited abduction to 160°, limited forward flexion, and a total arc of motion of <180°. Radiograph of the shoulder demonstrated multiple calcific intra-articular loose bodies consistent with synovial chondromatosis. Arthroscopic removal resulted in resolution of symptoms at the 36-week follow-up. Conclusions: Our literature search revealed only eight case reports on shoulder synovial chondromatosis in children. The location of the chondromatosis within the shoulder joint can be intra-articular, extra-articular, within the biceps sheath, or combined. In general, for chondomatoses confined to the glenohumeral joint space, open surgery is not required. Bony erosions can occur in the setting of chondromatosis though may not need to be addressed surgically. Although rare, this diagnosis should be considered when confronted with shoulder pain that is exacerbated during long athletic events with limited range of motion on physical examination in the adolescent athlete. Arthroscopic treatment in conjunction with physical therapy and early mobilization can lead to a successful outcome.

Hip Arthroscopy in the High-Level Athlete: Does Capsular Closure Make a Difference?

BACKGROUND: Hip arthroscopy has been shown to be effective in athletes who have femoral acetabular impingement and labral tearing. The effect of complete capsular closure versus nonclosure on return to play is unknown. HYPOTHESIS: Complete capsular closure after hip arthroscopy would lead to a higher rate and faster return to sports in high-level athletes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A nonrandomized retrospective review was performed of high school, collegiate, and professional athletes undergoing hip arthroscopy by a single high-volume hip arthroscopic surgeon. Athletes were divided into those undergoing complete capsular closure (CC group) and non-capsular closure (NC group) after hip arthroscopy. Rate and time to return to play were determined between the 2 groups. Patient-reported outcomes including modified Harris Hip Score (mHHS), Hip Outcome Score Activities of Daily Living (HOS-ADL), and Hip Outcome Score Sport-Specific Subscale (HOS-SSS) were obtained at a minimum of 2 years. RESULTS: A total of 111 athletes with a minimum 2-year follow-up were included in the study. There were 62 in the CC group and 49 in the NC group. A higher percentage of athletes in the CC group returned to play compared with that in the NC group (90.3% vs 75.5%, respectively; P = .03). The CC group returned to play at a mean ± SD of 4.7 ± 1.9 months compared with 5.8 ± 2.6 months in the NC group (P < .001). Patients in the CC group met the minimal clinically important difference for the mHHS, HOS-ADL, and HOS-SSS patient-reported outcomes at higher percentages: mHHS, 98.3% vs 87.7% for CC vs NC, respectively (P = .02); HOS-ADL, 98.3% vs 87.7% (P = .02); and HOS-SSS, 96.7% vs 89.7% (P = .13). The difference between groups was statistically significant for mHHS and HOS-ADL. CONCLUSION: Complete capsular closure after hip arthroscopy was associated with faster return to play and a higher rate of return compared with that of nonclosure of the capsule in this sample population of high-level athletes. At a minimum 2-year follow-up, complete capsular closure was associated with significantly higher patient-reported outcomes compared with those of nonclosure in athletes who underwent hip arthroscopy.

A Biomechanical Comparison of the Arciero and LaPrade Reconstruction for Posterolateral Corner Knee Injuries.

BACKGROUND: Injury to the posterolateral corner (PLC) of the knee requires reconstruction to restore coronal and rotary stability. Two commonly used procedures are the Arciero reconstruction technique (ART) and the LaPrade reconstruction technique (LRT). To the authors' knowledge, these techniques have not been biomechanically compared against one another. PURPOSE: To identify if one of these reconstruction techniques better restores stability to a PLC-deficient knee and if concomitant injury to the proximal tibiofibular joint or anterior cruciate ligament affects these results. STUDY DESIGN: Controlled laboratory study. METHODS: Eight matched-paired cadaveric specimens from the midfemur to toes were used. Each specimen was tested in 4 phases: intact PLC (phase 1), PLC sectioned (phase 2), PLC reconstructed (ART or LRT) (phase 3), and tibiofibular (phase 4A) or anterior cruciate ligament (phase 4B) sectioning with PLC reconstructed. Varus angulation and external rotation at 0º, 20º, 30º, 60º, and 90º of knee flexion were quantified at each phase. RESULTS: In phase 3, both reconstructions were effective at restoring laxity back to the intact state. However, in phase 4A, both reconstructions were ineffective at stabilizing the joint owing to tibiofibular instability. In phase 4B, both reconstructions had the potential to restrict varus angulation motion. There were no statistically significant differences found between reconstruction techniques for varus angulation or external rotation at any degree of flexion in phase 3 or 4. CONCLUSION: The LRT and ART are equally effective at restoring stability to knees with PLC injuries. Neither reconstruction technique fully restores stability to knees with combined PLC and proximal tibiofibular joint injuries. CLINICAL RELEVANCE: Given these findings, surgeons may select their reconstruction technique based on their experience and training and the specific needs of their patients.

Patellar Instability: When is Trochleoplasty Necessary?

Trochleoplasty is a very effective procedure for correcting trochlear dysplasia and addressing instability of the patella. With an increasing knowledge about the anatomy and biomechanics of the anterior distal femur, a wider array of surgical techniques may be applied to address specific conditions. Patients must be carefully selected to undergo trochleoplasty by use of a thorough history and physical examination as well as basic and advanced imaging. The presence of a "J sign" on physical examination, a history of recurrent instability, patella alta, trochlear dysplasia, and elevated tibial tubercle to trochlear groove are signs and symptoms for which the patient should be evaluated. We attempt to elucidate when trochleoplasty is indicated by means of addressing all aspects of evaluation.

The Utility of Objective Strength and Functional Performance to Predict Subjective Outcomes After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Many clinicians release patients to return to activity after anterior cruciate ligament reconstruction (ACLR) based on time from surgery despite deficits in muscle strength and function. It is unclear whether symmetry or unilateral performance is the best predictor of subjective outcomes after ACLR. PURPOSE: To determine physical performance predictors of patient-reported outcomes after reconstruction. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A total of 88 participants (49 males, 39 females; mean ± SD height, 174.0 ± 9.6 cm; weight, 76.1 ± 18.5 kg; age, 19.4 ± 3.7 years) who underwent primary, unilateral ACLR volunteered for this study. Participants had undergone reconstruction a mean of 6.9 ± 1.8 months (range, 5.0-14.1 months) before the study. All participants underwent strength testing as well as hop testing and then completed the International Knee Documentation Committee (IKDC) and Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaires. Stepwise linear regression models were used for symmetry and unilateral performance to identify the proportion of variance explained in the IKDC score, KOOS total score, KOOS-sport subscale, and time from surgery, as well as receiver operating characteristic (ROC) curve analyses on those variables that explained the most variance in patient-reported outcomes to determine cutoff thresholds. RESULTS: No significant correlations were found between time from surgery and objective performance. The only significant predictors of IKDC score were single-hop limb symmetry index (LSI) and age (R2 = 0.177) and unilateral triple-hop performance and age (R2 = 0.228). The cutoff for single-hop symmetry was 0.92 (area under the curve [AUC], 0.703; P = .012), and the cutoff for normalized triple-hop distance was 3.93 (AUC, 0.726; P = .005). When stratified by age, the cutoff for single-hop symmetry was 0.81 (AUC, 0.721; P = .051) for younger patients (age <19.1 years) and was not significant for older patients (age ≥19.1 years). The cutoff for normalized triple-hop distance was 3.85 (AUC, 0.832; P = .005) in older patients and was not significant for younger patients. The only significant predictors of KOOS-sport subscale were single-hop LSI (R2 = 0.140) and normalized knee extensor power at 180 deg/s (R2 = 0.096). When subjective outcomes were predicted based on KOOS-sport subscale, the cutoff for single-hop symmetry was 0.85 (AUC, 0.692; P = .018). CONCLUSION: Hopping performance is the most predictive functional variable of subjective outcomes after reconstruction. Single-hop symmetry was most important for younger patients and unilateral triple-hop distance was most important for older patients. Clinicians should consider hopping performance when making return-to-activity decisions after ACLR.

Surgical treatment of medial instability of the knee.

Medial collateral ligament (MCL) injuries are commonly seen in orthopedic practice. Most MCL injuries are isolated and can be treated nonsurgically with focus on brace protection of the ligament, range of motion, gait training, and relatively quick return to full activity. A subset of MCL injuries, however, requires operative treatment. It is critical to identify patients with medial instability and develop an operative plan that will restore stability and function to the injured knee. Many MCL reconstruction and repair techniques have been described, and improvement in outcomes with improvement of technique remains an area of great interest. This review discusses several MCL reconstruction options and outlines the authors' preferred MCL reconstruction technique.

Thoracic spine sports-related injuries.

Although sports-related injuries to the thoracic spine are relatively uncommon, they are among the most feared due to the potential for catastrophic neurologic injury. The increased biomechanical support of the thoracic spine makes injuries in this region particularly rare compared with the cervical and lumbar spine. As a result, thoracic spine injuries can be missed easily, difficult to diagnose, and problematic to treat. Recognition of mechanism and awareness of injury patterns help physicians determine a diagnosis and create an index of suspicion for unstable thoracic spine injuries. Aggressive full-contact sports receive the most attention for spinal injury; however several sports with repetitive loading of the spine can cause severe injuries, including rowing, gymnastics, and golf. The goal of this article was to provide an overview of the unique anatomic and biomechanical features of the thoracic spine and to discuss some of the more common thoracic injuries that can affect athletes.

Dynamic versus static analyses of lifting a box from the floor.

Lifting objects from below knee height has been implicated as a source of low back pain and injury. Static models have often been used to assess forces produced in the lumbar region by lifting; however, inertial forces generated by acceleration may be significant. Therefore, the goal of this investigation was to assess differences between static and dynamic analysis methods. Sagittal plane kinematics were collected on 21 men and 22 women of college age while lifting a milk crate (men = 25 kg, women = 15 kg) from the floor to standing knuckle height on level as well as sloped (facing uphill and downhill at 10 degrees and 20 degrees) ground conditions. Both static and dynamic top-down inverse models were utilized to assess net muscular moments at L5/S1 as well as the posture of the person at the time of static max (TSM) and dynamic max (TDM) moments. The TDM moment was significantly later than the TSM in the level through uphill conditions (p < 0.001). The dynamic max moment was significantly greater than the static max moment in all conditions (p < 0.001). Torso angles at TSM exhibited a significantly greater forward lean (by < 2 degrees) in the level through uphill conditions (p < 0.001). Overall low-back curvature, hip angles, knee angles, and ankle angles were not affected by the type of model (p > 0.05), though several minor differences occurred at conditions other than the level (most dramatic in the downhill 20 degrees condition). Therefore, if moments are of interest, a dynamic model should be utilized. However, body position is very similar at TSM and TDM.