Bone Marrow Aspirate Concentrate Augmentation May Accelerate Allograft Ligamentization in Anterior Cruciate Ligament Reconstruction: A Double-Blinded Randomized Controlled Trial.

PURPOSE: To assess the effect of bone marrow aspiration concentrate (BMAC) augmentation on clinical outcomes and magnetic resonance imaging (MRI) findings in anterior cruciate ligament (ACL) reconstruction (ACLR) with bone-patellar tendon-bone (BTB) allografts. METHODS: A double-blinded, randomized controlled trial was conducted on 80 patients undergoing ACL reconstruction using BTB allografts. Patients were randomized to 2 groups: (1) bone marrow aspirate was collected from the iliac crest, concentrated, and approximately 2.5 mL was injected into the BTB allograft, or (2) a small sham incision was made at the iliac crest (control). MRI was performed at 3 months and 9 months postoperatively to determine the signal intensity ratio of the ACL graft. RESULTS: Seventy-three patients were available for follow-up at 1-year postoperatively (36 BMAC, 37 control). International Knee Documentation Committee (IKDC) scores were significantly greater in the BMAC group versus the control at the 9-month postoperative period (81.6 ± 10.5 vs 74.6 ± 14.2, P = .048). There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months (89% vs 85%; P = .7). Three months postoperatively, signal intensity ratio of the inferior third of the ACL graft was significantly greater in the BMAC group versus the control group (3.2 ± 2.2 vs 2.1 ± 1.5; P = .02). CONCLUSIONS: Patients who received BMAC augmentation of the BTB allograft during ACL reconstruction demonstrated greater signal intensity scores on MRI at 3 months, suggesting increased metabolic activity and remodeling, and potentially accelerated ligamentization. Additionally, patients in the BMAC group had greater patient-reported outcomes (IKDC) at 9 months postoperatively when compared with those who underwent a standard surgical procedure. There was no significant difference in the proportion of patients who met the minimal clinically important difference for IKDC between the BMAC and control groups at 9 months, suggesting limited clinical significance at this time point. LEVEL OF EVIDENCE: I, randomized control trial.

Patients Follow 3 Different Rate-of-Recovery Patterns After Anterior Cruciate Ligament Reconstruction Based on International Knee Documentation Committee Score.

PURPOSE: To determine whether subgroups of patients exist based on the rate-of-recovery pattern of International Knee Documentation Committee (IKDC) scores after anterior cruciate ligament reconstruction (ACLR) and to determine clinical predictors for these subgroups. METHODS: Patients who underwent primary or revision ACLR at a single institution from January 2014 to January 2019 were identified. Latent class growth analyses and growth mixture models (GMMs) with 1 to 6 classes were used to identify subgroups of patients based on functional rate-of-recovery patterns by use of preoperative, 1-year postoperative, and 2-year postoperative IKDC scores. RESULTS: A total of 245 patients who underwent ACLR were included in the analysis. A 3-class GMM was chosen as the final model after 6 different models were run. Class 1, showing improvement from preoperatively to 1-year follow-up, with sustained improvement from 1 to 2 years postoperatively, constituted 77.1% of the study population (n = 189), whereas class 2, showing functional improvement between 1- and 2-year follow-up, was the smallest class, constituting 10.2% of the study population (n = 25), and class 3, showing slight improvement at 1-year follow-up, with a subsequent decline in IKDC scores between 1- and 2-year follow-up, constituted 12.7% of the study population (n = 31). Revision surgery (P = .005), a psychiatric history (P = .025), preoperative chronic knee pain (P = .024), and a subsequent knee injury within the follow-up period (P = .011) were the predictors of class 2 and class 3 rate-of-recovery patterns. Patient demographic characteristics, graft type, and concomitant ligament, meniscus, or cartilage injury at the time of surgery were not associated with the different recovery patterns described in this study. CONCLUSIONS: Patients may follow different rate-of-recovery patterns after ACLR. By use of the GMMs, 3 different rate-of-recovery patterns based on IKDC scores were identified. Although most patients follow a more ideal rate-of-recovery pattern, fewer patients may follow less favorable patterns. Revision surgery, a history of psychiatric illness, preoperative chronic knee pain, and a subsequent knee injury within the follow-up period were predictive of less favorable rate-of-recovery patterns. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Establishing Clinically Significant Outcomes After Anterior Cruciate Ligament Reconstruction in Pediatric Patients.

PURPOSE: The purpose of this study was to establish clinically significant outcome values for the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) after anterior cruciate ligament reconstruction (ACLR) in the pediatric and adolescent populations and to assess factors that were associated with achieving these outcomes. METHODS: Patients between the age of 10 to 21 who underwent ACLR between 2016 and 2018 were identified and patient-reported outcomes (PROs) were collected preoperatively and postoperatively. Intraoperative variables collected included graft choice, graft size (diameter), graft fixation method, and concomitant procedures. PROs collected for analysis were the International Knee Documentation Committee Score (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS). MCID and PASS were calculated using receiver operating characteristic with area under the curve analyses for delta (ie, baseline-to-postoperative change) and absolute postoperative PRO scores, respectively. RESULTS: A total of 59 patients were included in the analysis. Of the entire study population, 53 (89.8%) reported satisfaction with their surgical outcome. The established MCID threshold values based on the study population were 33.3 for IKDC, 28.6 for (KOOS) Symptoms, 19.4 for Pain, 2.9 for activities of daily living (ADL), 45.0 for Sport, and 25.0 for Quality of Life (QoL). Postoperative scores greater than the following values corresponded to the PASS: 80.5 for IKDC, 75.0 (KOOS) Symptoms, 88.9 for Pain, 98.5 for ADL, 75.0 for Sport, and 68.8 for QoL. CONCLUSION: Clinically meaningful outcomes including MCID and PASS were established for pediatric ACLR surgery using selected PRO measures, IKDC, and KOOS. Patient age, sex, graft type, and graft size were not associated with greater achievement of these outcomes. In contrast, collision sports, fixed-object high-impact rotational landing sports, and concomitant meniscectomy surgery were associated with a decreased likelihood of achieving clinically significant improvement. However, findings must be interpreted with caution due to limitations in follow-up and sample size. LEVEL OF EVIDENCE: Level IV: case series.

Establishing the Minimal Clinically Important Difference and Patient-Acceptable Symptomatic State After Arthroscopic Meniscal Repair and Associated Variables for Achievement.

PURPOSE: To establish the minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) after arthroscopic meniscal repair and identify the factors associated with achieving these outcomes. METHODS: This is a retrospective study with prospectively collected data. Patient-reported outcome measures (PROMs) were collected from April 2017 to March 2020. All patients who underwent arthroscopic meniscal repair and completed both preoperative and postoperative PROMs were included in the analysis. MCID and PASS were calculated via half the standard deviation of the delta PRO change from baseline (for International Knee Documentation Committee Score [IKDC]) and via anchor-based methodology (Knee Injury and Osteoarthritis Outcome Score [KOOS] subscales). RESULTS: Sixty patients were included in the final analysis. The established MCID threshold values were 10.9 for IKDC, 12.3 for KOOS Symptoms, 11.8 for KOOS Pain, 11.4 for KOOS Activities of Daily Living (ADL), 16.7 for KOOS Sport, and 16.9 for KOOS Quality of Life (QoL). Postoperative scores greater than the following values corresponded to the PASS: 69.0 for IKDC, 75.0 for KOOS Symptoms, 80.6 for KOOS Pain, 92.7 for KOOS ADL, 80.0 for KOOS Sport, and 56.3 for KOOS QoL. Higher preoperative PRO scores were associated with lower likelihood of achieving MCID. Concomitant ligament procedures were associated with a higher likelihood of achieving PASS. Tears to both menisci were associated with decreased likelihood of achieving MCID and PASS for IKDC. Horizontal tears were associated with decreased likelihood of achieving PASS for IKDC and KOOS. Complex tears were associated with decreased likelihood of achieving MCID for KOOS. CONCLUSION: Clinically meaningful outcomes such as MCID and PASS were established for meniscal repair surgery using selected PROMs for IKDC and KOOS subscales. Variables more likely to be associated with achieving these outcomes include lower preoperative PRO score and concomitant ligament procedure, whereas higher preoperative PRO score, tearing of both medial and lateral menisci, and horizontal and complex tear classifications were associated with decreased likelihood of achieving these outcomes. LEVEL OF EVIDENCE: IV, retrospective case series.

Randomized Trial of Arthroscopic Rotator Cuff With or Without Acromioplasty: No Difference in Patient-Reported Outcomes at Long-Term Follow-Up.

PURPOSE: To evaluate long-term patient-reported outcomes and revision surgery after arthroscopic rotator cuff repair with or without acromioplasty. METHODS: Between 2007 and 2011, prospectively enrolled patients undergoing arthroscopic repair for full-thickness rotator cuff tears, with any acromial morphology, were randomized into either acromioplasty or nonacromioplasty groups. Patients with revision surgery, subscapularis involvement, advanced neurologic conditions, or death were excluded. Baseline and long-term follow-up questionnaires, including the American Shoulder and Elbow Surgeons (ASES), Simple Shoulder Test (SST), University of California-Los Angeles (UCLA), Visual Analog Scale (VAS) for pain, and Constant scores were obtained. Rates of symptomatic retear, revision rotator cuff surgery, or secondary reoperation were recorded. Averages with standard deviation were calculated, and t-tests were used to compare outcomes of interest between cohorts. RESULTS: In total, 69 of 90 patients (76.7%) were available at 92.4 months (± 10.5). There were 23 of 32 patients in the acromioplasty cohort and 24 of 37 patients in the nonacromioplasty cohort. Mean age for the nonacromioplasty cohort was 56.9 (± 7.6) years, whereas acromioplasty was 59.6 (± 6.8) years. Comparison of baseline demographics and intraoperative information revealed no significant differences, including age, sex, Workers' Compensation, acute mechanism of injury, tear size, degree of retraction, and surgical technique (e.g., single- vs. double-row). At final follow-up, there were no statistically significant differences according to ASES (P = .33), VAS pain (P = 0.79), Constant (P = .17), SST (P = .05), UCLA (P = .19), and Short Form-12 (SF-12) (P = .79) in patients with and without acromioplasty. Two patients with acromioplasty (5.6%) and 3 patients without acromioplasty (9.1%) sustained atraumatic recurrent rotator cuff tear with secondary repair (P = .99), and there was no significant difference in retear rates or patient-reported outcome measures by acromial morphology. CONCLUSIONS: This randomized trial, with mean 7.5-year follow-up, found no difference in validated patient-reported outcomes, retear rate, or revision surgery rate between patients undergoing rotator cuff repair with or without acromioplasty. LEVEL OF EVIDENCE: II, prospective randomized controlled trial.

Does Bone Plug and Graft Orientation (Inferior Versus Posterior) Alter Native Femoral Footprint Coverage in Bone Patellar Tendon Bone Anterior Cruciate Ligament Reconstruction?

PURPOSE: The purpose of this study was to compare the percentage of native femoral anterior cruciate ligament (ACL) footprint covered by the 2 most clinically relevant bone plug/graft orientations used with interference screw fixation in ACL reconstruction. A secondary purpose was to assess whether a transtibial or tibia-independent drilling technique would affect this outcome. METHODS: Five matched pairs of cadaver knees were used. Each matched pair had 1 knee assigned to a 10-mm femoral socket prepared via a transtibial (TT) drilling technique and the other via an anteromedial (AM) drilling technique. The bone plug of each graft was press-fitted into the femoral socket with the graft collagen in 2 distinct clinically relevant orientations (collagen inferior or posterior). The digitized graft collagen cross-sectional area (CSA) in each orientation was overlaid onto the native femoral ACL footprint CSA to generate a percentage of native ACL footprint covered by graft collagen. RESULTS: The average native ACL femoral footprint CSA was 110.5 ± 9.1 mm2, with no difference between knees assigned to TT or AM drilling (112.6 ± 2.7 vs 108.4 ± 13.0 mm2, P = .49). The average femoral socket CSA was 95.4 ± 8.7 mm2, with no difference between TT and AM tunnels (95.5 ± 9.9 vs 95.3 ± 8.4 mm2, P = .96). There was no difference between the percentage of native footprint covered between TT and AM sockets (76.8% ± 7.8% vs 82.2% ± 13.7%, P = .47). Irrespective of drilling technique, there was significantly greater native ACL footprint covered by graft collagen when the bone plug was oriented with graft collagen inferior rather than posterior (75.6% ± 6.3% vs 65.4% ± 11.4%, P = .02). CONCLUSION: Orienting the femoral bone plug such that the graft collagen is inferior rather than posterior significantly increases native ACL femoral footprint coverage in bone-patellar tendon-bone ACL reconstruction. This effect is consistent across AM and TT drilling techniques. CLINICAL RELEVANCE: Surgeons attempting to restore an anatomic ACL footprint should consider bone plug-graft orientation when performing ACL reconstruction. STUDY DESIGN: Controlled laboratory study.

Degenerative Meniscus Lesions: An Expert Consensus Statement Using the Modified Delphi Technique.

PURPOSE: The purpose of this study was to perform an evidence-based, expert consensus survey using the Delphi panel methodology to develop recommendations for the treatment of degenerative meniscus tears. METHODS: Twenty panel members were asked to respond to 10 open-ended questions in rounds 1 and 2. The results of the first 2 rounds served to develop a Likert-style questionnaire for round 3. In round 4, the panel members outside consensus were contacted and asked to either change their score in view of the group's response or argue their case. The level of agreement for round 4 was defined as 80%. RESULTS: There was 100% agreement on the following items: insidious onset, physiological part of aging, tears often multiplanar, not all tears cause symptoms, outcomes depend on degree of osteoarthritis, obesity is a predictor of poor outcome, and younger patients (<50 years) have better outcomes. There was between 90% and 100% agreement on the following items: tears are nontraumatic, radiographs should be weightbearing, initial treatment should be conservative, platelet-rich plasma is not a good option, repairable and peripheral tears should be repaired, microfracture is not a good option for chondral defects, the majority of patients obtain significant improvement and decrease in pain with surgery but results are variable, short-term symptoms have better outcomes, and malalignment and root tears have poor outcomes. CONCLUSIONS: This consensus statement agreed that degenerative meniscus tears are a normal part of aging. Not all tears cause symptoms and, when symptomatic, they should initially be treated nonoperatively. Repairable tears should be repaired. The outcome of arthroscopic partial meniscectomy depends on the degree of osteoarthritis, the character of the meniscus lesion, the degree of loss of joint space, the amount of malalignment, and obesity. The majority of patients had significant improvement, but younger patients and patients with short-term symptoms have better outcomes. LEVEL OF EVIDENCE: Level V - expert opinion.

Automated 3-Dimensional Magnetic Resonance Imaging Allows for Accurate Evaluation of Glenoid Bone Loss Compared With 3-Dimensional Computed Tomography.

PURPOSE: To evaluate clinical measurements of glenoid bone loss based on 3-dimensional (3D) computed tomography (CT) and automatically segmented 3D reconstructions from Dixon fat-water magnetic resonance (MR) imaging. METHODS: Available CT and MR studies from 16 patients with recurrent anterior shoulder instability were retrospectively reviewed. Three-dimensional reconstructions were formed independently by 2 observers using freely available software and a simple threshold-based segmentation (3D Slicer, version 4.8.0; http://www.slicer.org). Bone loss was estimated with the perfect-circle method. Intra-user and interuser reproducibility was determined with intraclass correlation coefficients. Bland-Altman plots were used to evaluate the similarity between imaging modalities. RESULTS: Differences between MR and CT estimates of bone loss ranged from 0% to 6%. The individual intraclass correlation coefficients showed good to excellent reliability, with intraobserver comparisons between MR- and CT-based bone loss estimates ranging from 0.94 to 0.99. Bland-Altman plots showed 95% confidence intervals from -5% to 6% for differences between MR and CT estimates, with 88% of all measurements (42 of 48) showing a less than 2% difference between MR and CT estimates. CONCLUSIONS: The described methodology for obtaining an MR-based 3D reconstruction of the glenoid can evaluate glenoid bone loss similarly to the performance of a 3D CT reconstruction. The results may allow surgeons to simplify the preoperative imaging protocol for patients with recurrent shoulder stabilization and limit the number of shoulder CT scans. LEVEL OF EVIDENCE: Level III, retrospective therapeutic trial.

Length of Time Between Anterior Cruciate Ligament Reconstruction and Return to Sport Does Not Predict Need for Revision Surgery in National Football League Players.

PURPOSE: To determine whether the length of time between primary anterior cruciate ligament reconstruction (ACLR) and return to sport (RTS) predicted the need for revision ACLR in National Football League (NFL) athletes. METHODS: All NFL players who underwent ACLR from 2009 to 2015 were identified. The date of index ACLR and date of return to NFL regular-season game play after surgery were recorded. The length of time between ACLR and RTS was compared between players who required revision ACLR and those who did not. Correlation coefficients were used to assess whether players who RTS sooner sustained recurrent anterior cruciate ligament injury at an earlier date. RESULTS: A total of 130 NFL players (average age, 25.3 ± 3.2 years) who underwent ACLR and returned to sport were identified. The average time to RTS after ACLR was 49.7 weeks after surgery. Of the players, 23 (18%) required revision ACLR. There was no significant difference in the length of time between ACLR and RTS in players who did not require revision ACLR (50.2 ± 10.1 weeks) and those who did (48.3 ± 11.0 weeks, P = .40). Time to RTS was not found to correlate with time to reinjury in athletes requiring revision ACLR (R = 0.21; 95% confidence interval, -0.18 to 0.54). A large proportion of players (56%) sustained a reinjury within the first 10 weeks of returning to NFL game play. CONCLUSIONS: Our study found that timing of RTS after ACLR was not a significant risk factor for revision surgery in NFL athletes. Time to RTS was also not shown to correlate with time to reinjury. LEVEL OF EVIDENCE: Level III, case-control study.

Biceps Tenodesis Is a Viable Option for Management of Proximal Biceps Injuries in Patients Less Than 25 Years of Age.

PURPOSE: To evaluate outcomes after biceps tenodesis performed in patients younger than 25 years, to evaluate reoperations and complications in this population, and to critically appraise return to preinjury level of play for this population. METHODS: Forty-five consecutive patients younger than 25 years underwent subpectoral biceps tenodesis for biceps tendinopathy or biceps-labral complex injuries including SLAP tears. Biceps tenodesis was performed using an interference screw technique. Patients with a minimum 2-year follow-up were analyzed. Functional outcomes were assessed with the visual analog scale score, American Shoulder and Elbow Surgeons (ASES) score, ASES functional score, Simple Shoulder Test score, and range of motion. Activity level and return to sport were followed postoperatively. RESULTS: Of the 45 patients younger than 25 years who underwent biceps tenodesis, 36 (80%) were available for follow-up at a minimum of 2 years, with a mean age of 19.8 years and mean follow-up period of 38.6 months. Of these 36 patients, 34 (94%) were athletes, with 20 patients playing at collegiate level. All clinical outcome scores improved, with the ASES score improving from 54.7 to 81.7, the ASES functional score improving from 17.5 to 25.1, and the Simple Shoulder Test score improving from 7.4 to 10.1 (P < .001). At the time of follow-up, 4 patients (11%) had undergone revision surgery for other injuries. Of the 34 athletes, 25 (73%) returned to sports, with 19 returning at the same level and 6 returning at a lower level of play; 77% of overhead athletes returned to sports. CONCLUSIONS: When indicated, biceps tenodesis offers an alternative to SLAP repair in young patients. Biceps tenodesis in patients younger than 25 years yields satisfactory outcomes, with two-thirds of patients returning to sport and a low revision rate. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Proximal fixation anterior to the lateral femoral epicondyle optimizes isometry in anterolateral ligament reconstruction.

PURPOSE: Concomitant anterolateral ligament (ALL) injury is often observed in patients with an anterior cruciate ligament injury leading some to recommend concurrent ALL reconstruction. In ligament reconstruction, it is imperative to restore desirable ligament length changes to prevent stress on the graft. The purpose of this investigation is to identify the optimal femoral and tibial locations for fixation in ALL reconstruction. METHODS: 3D computerized tomography (CT) knee models were obtained from six fresh-frozen, unpaired, cadaveric human knees at 0°, 10°, 20°, 30°, 40°, 90°, 110°, and 125°of knee flexion. Planar grids were projected onto the lateral knee. Isometry between each tibial and femoral grid point was calculated at each angle of flexion by the length change in reference to the length at 0° of knee flexion. The mean normalized length change over the range of motion was calculated for each combination of points at all angles of flexion were calculated. RESULTS: Fixation of the ALL to the lateral femoral epicondyle or 5 mm anterior to the epicondyle with tibial fixation on the posteroinferior aspect of the tibial condyle (14-21 mm posterior to Gerdy's tubercle and 13-20 mm below the joint line) provided the lowest average length change for all possible ALL tibial insertion points. Minimal length change for all femoral fixation locations occurred from 20° to 40° of flexion, which identifies the angle of flexion where graft tensioning should occur intraoperatively. CONCLUSION: With the use of 3D reconstructed models of knee-CT scans, we observed that there was no ALL fixation point that was truly isometric throughout range of motion. Fixation of the anterolateral ligament on the lateral femoral epicondyle or anterior to the lateral femoral epicondyle and on the inferoposterior aspect of the tibial condyle restores isometry. Additionally, minimal length change was observed between 20° and 40° of flexion, which is the most appropriate range of knee flexion to tension the graft. Reproducing isometry reduces stress on the graft, which minimizes the risk of graft failure.

Dynamic 3-Dimensional Mapping of Isometric Anterior Cruciate Ligament Attachment Sites on the Tibia and Femur: Is Anatomic Also Isometric?

PURPOSE: The purpose of this study was to (1) map the length changes of the medial wall of the lateral femoral condyle (MWLFC) with respect to various points about the tibial anterior cruciate ligament (ACL) footprint to determine the area that demonstrates the least amount of length change through full range of motion and (2) to identify a range of flexion that would be favorable for graft tensioning. METHODS: Six fresh-frozen cadaveric knees were obtained from screened individuals with no prior history of arthritis, cancer, surgery, or any ligamentous knee injury. For each knee, 3-dimensional computed tomography point-cloud models were obtained in succession from 0° to 135°. A point grid was placed on the MWLFC and the tibia. Intra-articular length was calculated for each point on the femur to the tibia at all flexion angles and grouped to represent areas for bone tunnels. Normalized length changes were compared. RESULTS: Areas anterior/distal on the MWLFC increased with increasing flexion, and areas proximal/posterior decreased with increasing flexion. The area about the intersection of the lateral intercondylar ridge and the bifurcate ridge was most isometric throughout flexion as no significant change in ligament length was found throughout flexion. The normalized length changes from the central position of the tibia showed no significant difference compared with the anterior or posterior tibial position. CONCLUSIONS: No area of the MWLFC is truly isometric through flexion. Femoral tunnel placement slightly anterior to the center of the anteromedial and posterolateral bundles was most isometric. Minimal length change occurs between 10° and 40°, which reflects the range where graft tensioning was most often performed. The results of this study provide further support for an anatomic ACL reconstruction. CLINICAL RELEVANCE: The femoral tunnel location for ACL reconstruction with the least amount of length change through range of motion should encompass the direct fibers of the ACL.

Utility of Modern Arthroscopic Simulator Training Models: A Meta-analysis and Updated Systematic Review.

PURPOSE: To determine the utility of modern arthroscopic simulators in transferring skills learned on the model to the operating room. METHODS: A meta-analysis and systematic review of all English-language studies relevant to validated arthroscopic simulation models using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) guidelines from 1999 to 2016 was performed. Data collected included the specific simulator model, the joint used, participant demographic characteristics, participant level of training, training session information, type and number of tasks, pre- and post-training assessments, and overall outcomes of simulator performance. Three independent reviewers analyzed all studies. RESULTS: Fifty-seven studies with 1,698 participants met the study criteria and were included. Of the studies, 25 (44%) incorporated an arthroscopic training program into the study methods whereas 32 (56%) did not. In 46 studies (81%), the studies' respective simulator models were used to assess arthroscopic performance, whereas 9 studies (16%) used Sawbones models, 8 (14%) used cadaveric models, and 4 (7%) evaluated subject performance on a live patient in the operating room. In 21 studies (37%), simulator performance was compared with experience level, with 20 of these (95%) showing that clinical experience correlated with simulator performance. In 25 studies (44%), task performance was evaluated before and after simulator training, with 24 of these (96%) showing improvement after training. All 4 studies that included live-patient arthroscopy reported improved operating room performance after simulator training compared with the performance of subjects not participating in a training program. CONCLUSIONS: This review suggests that (1) training on arthroscopic simulators improves performance on arthroscopic simulators and (2) performance on simulators for basic diagnostic arthroscopy correlates with experience level. Limited data suggest that simulator training can improve basic diagnostic arthroscopy skills in vivo. LEVEL OF EVIDENCE: Level IV, systematic review of Level I through IV studies.

The Influence of Bone Loss on Glenoid Version Measurement: A Computer-Modeled Cadaveric Analysis.

PURPOSE: To characterize how increasing computed tomography (CT)-quantified glenoid bone loss influences measured version. METHODS: Six embalmed cadaveric shoulders were used for this study. Glenoid bone defects were computer modeled in cadaveric shoulders; CT images were obtained and segmented using OsiriX software, creating 3-dimensional en face glenoids. Glenoid defects were made on CT images of intact glenoids superimposed with a glenoid clock face viewed en face to simulate anterior and posterior bone loss. Bony defects in various positions comprising 3%, 9.5%, and 19.5% were created posteriorly. Best-fit circles were superimposed to represent 10% and 25% defects anteriorly. Version was measured using the Friedman method. RESULTS: The average glenoid version measured 4° of retroversion, 2° after 10% anterior bone loss, and neutral version in the 25% bone loss group. Version was significantly altered when we compared intact glenoids versus 10% and 25% anterior glenoid bone loss (P < .001). Increasing from 10% to 25% bone loss showed a significant difference in measured version (P = .025). Posterior defects from the 6:30 to 8:30 clock-face position averaged 4.6° of retroversion; from the 6:30 to 9:30 clock-face position, 6.2° of retroversion; and from the 6:30 to 10:30 clock-face position, 8.7° of retroversion. When comparing glenoid defects at the 6:30 to 8:30 clock-face position with those involving the 6:30 to 9:30 and 6:30 to 10:30 clock-face positions (P < .001), a 1° correction may be used for every 5% of bone loss to account for version changes seen with bone loss. CONCLUSIONS: In this cadaveric analysis, glenoid version was altered in the setting of increasing posterior and anterior bone loss. A correction factor may be considered to account for this. When comparing glenoid defects at the 6:30 to 8:30 clock-face position with those involving the 6:30 to 9:30 and 6:30 to 10:30 clock-face positions (P < .001), a 1° correction may be used for every 5% of bone loss to account for version changes seen with bone loss. CLINICAL RELEVANCE: This cadaveric study shows that glenoid bone loss alters glenoid version, as measured by CT, in a meaningful way. This information is important in managing anterior and posterior shoulder instability, and correction of measured version should be considered in this setting to provide an accurate and comprehensive evaluation.

The lack of standardized outcome measures following lower extremity injury in elite soccer: a systematic review.

PURPOSE: Sport-specific, performance-based outcomes are increasingly used to improve evaluation of treatment efficacy in elite athletes; however, its usage in elite soccer may be limited. The purpose of this investigation is to (1) assess current outcome reporting in elite soccer; (2) identify any variability in reporting of outcomes; and (3) determine how sport-specific performance-based outcomes are utilized to assess treatment efficacy in elite soccer. METHODS: A systematic review of the Pubmed, MEDLINE, and Embase, Scopus, SportDiscus, CINAHL and HealthSource: Nursing databases was performed without limitation on publication year. Inclusion criteria were (1) reporting of outcomes after a (2) lower extremity injury in (3) elite soccer players. The study's population, type of injury, return to play, as well as functional, objective, and sport-specific performance-based outcomes were extracted from each article. The methodological index for nonrandomized studies was used for quality assessment. RESULTS: Twenty-one studies were selected after application of the inclusion and exclusion criteria. Objective outcomes were reported by 6 (29%) studies, and 6 (29%) employed patient-reported outcomes. The visual analog scale, Lysholm, and Tegner scores were the most common patient-reported outcomes (PROs). Return to play was reported by 18 (86%) studies, and only 2 (10%) utilized sport-specific performance-based outcomes. Despite the majority of studies reporting return to play, variation was seen in the definitions, and 15 (71%) studies reported the activity level of the players at final follow-up. CONCLUSION: Assessment of treatment efficacy is limited in elite athletes, and PROs lack the sensitivity to identify residual performance deficits after an injury. Although performance-based measures are available at the elite level, these outcomes were seldom used for evaluation of treatment efficacy. CLINICAL RELEVANCE: When treating elite soccer players, patient-reported outcome measures lack the sensitivity to detect changes in patient function, thus performance-based metrics may be more efficacious in assessing return from injury in these patients. LEVEL OF EVIDENCE: IV.

What Factors Influence the Biomechanical Properties of Allograft Tissue for ACL Reconstruction? A Systematic Review.

BACKGROUND: Allograft tissue is used in 22% to 42% of anterior cruciate ligament (ACL) reconstructions. Clinical outcomes have been inconsistent with allograft tissue, with some series reporting no differences in outcomes and others reporting increased risk of failure. There are numerous variations in processing and preparation that may influence the eventual performance of allograft tissue in ACL reconstruction. We sought to perform a systematic review to summarize the factors that affect the biomechanical properties of allograft tissue for use in ACL reconstruction. Many factors might impact the biomechanical properties of allograft tissue, and these should be understood when considering using allograft tissue or when reporting outcomes from allograft reconstruction. QUESTIONS/PURPOSES: What factors affect the biomechanical properties of allograft tissue used for ACL reconstruction? METHODS: We performed a systematic review to identify studies on factors that influence the biomechanical properties of allograft tissue through PubMed and SCOPUS databases. We included cadaveric and animal studies that reported on results of biomechanical testing, whereas studies on fixation, histologic evaluation, and clinical outcomes were excluded. There were 319 unique publications identified through the search with 48 identified as relevant to answering the study question. For each study, we recorded the type of tissue tested, parameters investigated, and the effects on biomechanical behavior, including load to failure and stiffness. Primary factors identified to influence allograft tissue properties were graft tissue type, sterilization methods (irradiation and chemical processing), graft preparation, donor parameters, and biologic adjuncts. RESULTS: Load to failure and graft stiffness varied across different tissue types, with nonlooped tibialis grafts exhibiting the lowest values. Studies on low-dose irradiation showed variable effects, whereas high-dose irradiation consistently produced decreased load to failure and stiffness values. Various chemical sterilization measures were also associated with negative effects on biomechanical properties. Prolonged freezing decreased load to failure, ultimate stress, and ultimate strain. Up to eight freeze-thaw cycles did not lead to differences in biomechanical properties of cadaveric grafts. Regional differences were noted in patellar tendon grafts, with the central third showing the highest load to failure and stiffness. Graft diameter strongly contributed to load-to-failure measurements. Age older than 40 years, and especially older than 65 years, negatively impacted biomechanical properties, whereas gender had minimal effect on the properties of allograft tissue. Biologic adjuncts show potential for improving in vivo properties of allograft tissue. CONCLUSIONS: Future clinical studies on allograft ACL reconstruction should investigate in vivo graft performance with standardized allograft processing and preparation methods that limit the negative effects on the biomechanical properties of tissue. Additionally, biologic adjuncts may improve the biomechanical properties of allograft tissue, although future preclinical and clinical studies are necessary to clarify the role of these treatments. CLINICAL RELEVANCE: Based on the findings of this systematic review that emphasize biomechanical properties of ACL allografts, surgeons should favor the use of central third patellar tendon or looped soft tissue grafts, maximize graft cross-sectional area, and favor grafts from donors younger than 40 years of age while avoiding grafts subjected to radiation doses > 20 kGy, chemical processing, or greater than eight freeze-thaw cycles.

Optimization of Anteromedial Portal Femoral Tunnel Drilling With Flexible and Straight Reamers in Anterior Cruciate Ligament Reconstruction: A Cadaveric 3-Dimensional Computed Tomography Analysis.

PURPOSE: To use 3-dimensional custom CAD technology to evaluate how knee flexion angle affects femoral tunnel length and distance to the posterior wall when using curved and straight guides for drilling through the anteromedial portal (AMP). METHODS: Six cadaveric knees were placed in an external fixator at various degrees of flexion (90°, 110°, 125°, and maximum 135° to 140°). Computed tomography scans were obtained at all flexion points for 3-dimensional point-cloud models. Using custom CAD software, surgical guides through the AMP were replicated along with virtual tunnels at each flexion angle. Distance from the posterior cortex and tunnel dimensions were collected after 8-mm and 10-mm tunnel creation. RESULTS: At 90° of flexion, the average tunnel length down the posterior aspect of 8-mm tunnel was 25.0 mm (95% confidence interval [CI] 16.2-33.8) and 12.0 mm (95% CI 7.3-16.7) for curved and straight guides, respectively; 31.0 mm (95% CI 26.8-35.2) and 28.6 mm (95% CI 24.8-32.4) at 110°; 33.8 mm (95% CI 30.1-37.5) and 31.1 mm (95% CI 26.8-35.4) at 125°; and 35.0 mm (95% CI 34.1-35.9) and 35.5 mm (95% CI 34.2-36.8) with maximal flexion. Values between curved and straight guides are significantly different (P < .001), with straight guides breaching the posterior wall at 90° and 110° of flexion in some specimens. The average distance to the posterior wall cortex was 0.9 mm (95% CI -1.5 to 3.3) and -0.6 mm (95% CI -2.3 to 1.1) for curved and straight guides, respectively, at 90° of flexion (P = .014); 2.3 mm (95% CI -0.2 to 4.8) and -0.1 mm (95% CI -2.4 to 2.2) at 110° (P = .001); 4.4 mm (95% CI 2.8-6.0) and 3.9 mm (95% CI 1.9-5.9) at 125° (P = .299); and 6.7 mm (95% CI 6.2-7.2) and 8.3 mm (95% CI 6.1-10.5) at maximal flexion (P = .184). Posterior wall blowout was noted when using 10-mm straight guides at both 90° (2 specimens) and 110° (3 specimens). Using 10-mm curved guides posterior blowout was noted in 1 specimen at 90°. Maximum footprint coverage occurred at 110° for straight guides and 90° for curved guides. CONCLUSIONS: When using the AMP, flexible guides and reamers result in a greater distance of the tunnel to the femoral cortex while preserving adequate tunnel length at lower knee flexion angles. To create long femoral tunnels without breaching the posterior cortex, the knee should be flexed to at least 110° for curved reamers and 125° for straight. CLINICAL RELEVANCE: Femoral tunnel drilling through the AMP using curved and straight reamers requires different degrees of knee flexion to achieve optimal tunnel dimensions.

Three-Dimensional Magnetic Resonance Imaging Quantification of Glenoid Bone Loss Is Equivalent to 3-Dimensional Computed Tomography Quantification: Cadaveric Study.

PURPOSE: To assess the ability of 3-dimensional (3D) magnetic resonance imaging (MRI, 1.5 and 3 tesla [T]) to quantify glenoid bone loss in a cadaveric model compared with the current gold standard, 3D computed tomography (CT). METHODS: Six cadaveric shoulders were used to create a bone loss model, leaving the surrounding soft tissues intact. The anteroposterior (AP) dimension of the glenoid was measured at the glenoid equator and after soft tissue layer closure the specimen underwent scanning (CT, 1.5-T MRI, and 3-T MRI) with the following methods (0%, 10%, and 25% defect by area). Raw axial data from the scans were segmented using manual mask manipulation for bone and reconstructed using Mimics software to obtain a 3D en face glenoid view. Using calibrated Digital Imaging and Communications in Medicine images, the diameter of the glenoid at the equator and the area of the glenoid defect was measured on all imaging modalities. RESULTS: In specimens with 10% or 25% defects, no difference was detected between imaging modalities when comparing the measured defect size (10% defect P = .27, 25% defect P = .73). All 3 modalities demonstrated a strong correlation with the actual defect size (CT, ρ = .97; 1.5-T MRI, ρ = .93; 3-T MRI, ρ = .92, P < .0001). When looking at the absolute difference between the actual and measured defect area, no significance was noted between imaging modalities (10% defect P = .34, 25% defect P = .47). The error of 3-T 3D MRI increased with increasing defect size (P = .02). CONCLUSIONS: Both 1.5- and 3-T-based 3D MRI reconstructions of glenoid bone loss correlate with measurements from 3D CT scan data and actual defect size in a cadaveric model. Regardless of imaging modality, the error in bone loss measurement tends to increase with increased defect size. Use of 3D MRI in the setting of shoulder instability could obviate the need for CT scans. CLINICAL RELEVANCE: The goal of our work was to develop a reproducible method of determining glenoid bone loss from 3D MRI data and hence eliminate the need for CT scans in this setting. This will lead to decreased cost of care as well as decreased radiation exposure to patients. The long-term goal is a fully automated system that is as approachable for clinicians as current 3D CT technology.

Dial Test: Unrecognized Predictor of Anterior Cruciate Ligament Deficiency.

PURPOSE: To evaluate the effect of isolated anterior cruciate ligament (ACL) injury on tibial external rotation as measured by the dial test. METHODS: Twenty-seven consecutive patients scheduled to undergo a primary ACL reconstruction were prospectively evaluated. Physical examination and magnetic resonance imaging findings were analyzed to exclude multiligamentous injury. The dial test was performed with the patient under anesthesia with a goniometer on both the affected and unaffected knees at 30° and 90°. Intraoperatively, the arthroscopic posterolateral corner gaps before reconstruction and after reconstruction were documented. Postoperatively, the dial test was again performed on both knees at 30° and 90°. RESULTS: At 30°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.0°, P < .0001) and compared with the unaffected knee (27.6° vs 20.5°, P < .0001), but this difference was eliminated after reconstruction (21.0° vs 20.5°, P = .5089). At 90°, there was a significantly larger dial test result in the affected knee before ACL reconstruction compared with after ACL reconstruction (27.6° vs 21.1°, P < .0001) and compared with the unaffected knee (27.6° vs 20.9°, P < .0001), with this difference was eliminated after reconstruction (21.1° vs 20.9°, P = .7831). CONCLUSIONS: Incompetence of the ACL accounts for nearly 7° of tibial external rotation found by the dial test. During examination of an injured knee, if the dial test is positive, an isolated ACL injury should not be excluded. Findings of the dial test should thus be interpreted with caution in the setting of ACL injury. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Length of time between surgery and return to sport after ulnar collateral ligament reconstruction in Major League Baseball pitchers does not predict need for revision surgery.

HYPOTHESIS: Pitchers who return to sport (RTS) sooner will have a higher risk of revision ulnar collateral ligament reconstruction (UCLR) than those who return later. METHODS: All professional (major and minor league) baseball pitchers who underwent UCLR between 1974 and 2016 were identified. Date of the index UCLR was recorded. The date of the first game back at any professional level after surgery and the date the pitcher returned to the same level of play (if applicable) were recorded. Length of time between these dates was compared for pitchers who required a revision UCLR and those who did not. RESULTS: Overall, 569 pitchers (average age, 24.8 ± 4.1 years) underwent UCLR and had reliable game logs after surgery. No statistically significant difference existed in the length of time to RTS at any professional level or at the same professional level between those pitchers who did not require a revision UCLR and those who did (P = .442, P = .238). Pitchers who required revision UCLR returned to any level of play almost 2 months earlier (14.7 vs. 16.5 months) and returned to the same level of play >2 months earlier (15.2 vs. 17.7 months) than matched controls who did not require revision UCLR, although this was not statistically significant (P = .179, P = .204). CONCLUSION: No statistically significant difference existed in the length of time to RTS after UCLR in professional baseball players who required a revision UCLR and those who did not.