Combined Medial Collateral Ligament Reconstruction and Polyethylene Exchange for Valgus Instability Following Total Knee Arthroplasty.

Valgus instability can occur after total knee arthroplasty (TKA) due to traumatic medial collateral ligament (MCL) injury, component malpositioning, or progressive ligamentous laxity. Although revision TKA with exchange of the polyethylene to a varus-valgus-constrained liner can reduce laxity due to MCL insufficiency, isolated liner exchange in the setting of collateral ligament insufficiency may lead to greater strain at the cement-bone or implant-cement interface and possibly a greater rate of aseptic loosening. Anatomic MCL reconstruction can be performed in conjunction with liner exchange to restore stability and reduce strain compared with liner exchange alone. The purpose of this Technical Note is to describe a technique for MCL reconstruction and liner exchange for treatment of valgus instability after TKA.

The Principles of Knee Joint Preservation.

The 3 primary factors involved with preservation of the knee joint include joint alignment, meniscal status, and ligament stability (in particular that of the anterior cruciate ligament [ACL]). These factors are interdependent and result in knee joint homeostasis when all factors are stable. When a deficiency exists in one of the factors, it will affect the others. For example, the ACL and posterior horn of the medial meniscus both act as restraints to anterior tibial translation. Thus, medial meniscal deficiency increases the risk for failure of ACL reconstruction, and chronic ACL insufficiency increases the risk for medial meniscus tears. Furthermore, all 3 of the factors of joint preservation have an impact on the articular cartilage status of the knee joint. Studies have shown that cartilage-preservation procedures do not result in optimal outcomes if there is joint malalignment, meniscal deficiency, or ligament deficiency. When evaluating patients with knee cartilage pathology, surgeons should be aware of the various factors involved in knee joint preservation and, if surgery is indicated, all factors should be addressed in order to support a successful result.

Meniscotibial Ligament Insufficiency Increases Force on the Posterior Medial Meniscus Root.

BACKGROUND: Posterior medial meniscus root (PMMR) tears are a challenge to assess and treat. However, the forces sustained at the PMMR are yet to be fully characterized. In addition, it has been shown that meniscotibial ligament (MTL) injuries happen before PMMR tears, suggesting that insufficiency of the MTL results in a change of forces acting on the PMMR. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the 3-dimensional forces acting on the PMMR in the intact, MTL cut, and MTL tenodesis states. It was hypothesized that the MTL cut state would increase medial shear forces seen at the PMMR, whereas the medial shear force in the MTL tenodesis state would return PMMR forces to that of the intact state. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen cadaveric knees were tested in 3 states (intact, MTL cut, and tenodesis). A 3-axis load cell was installed below the posterior tibial plateau and attached to the enthesis of the PMMR. The specimen was mounted to a load frame that applied an axial load, an internal torque, and an external torque. The amount of compression-tension, mediolateral shear force, and anteroposterior shear force acting on the PMMR was measured. RESULTS: When the joint was loaded in compression, the MTL cut state significantly increased compression of the PMMR (P = .0368). The tenodesis state did not significantly restore forces of the PMMR (P = .008). When the joint was loaded in external torque, the MTL cut state significantly increased compression (P < .0001) and significantly decreased anterior shear on the PMMR (P = .0003). The tenodesis state did not significantly restore forces on the PMMR to the intact state (P < .0001). Increased flexion angle significantly increased medial shear forces of the PMMR when the joint was loaded in compression (P < .007 at every angle). CONCLUSION: When evaluated biomechanically, MTL insufficiency resulted in increased compressive force at the PMMR. A single-anchor centralization procedure did not restore PMMR forces to that of the intact state. Increased knee flexion angle resulted in increased medial shear force on the PMMR. CLINICAL RELEVANCE: The findings in this study provide clinicians information on PMMR forces when the MTL is disrupted. These data can aid in the decision-making for adding an MTL repair to augment PMMR repairs.

The Principles of Knee Joint Preservation: Operative Treatment Strategies.

➤ Joint alignment, meniscal status, and ligament stability are codependent factors involved in knee joint preservation, and any injury or imbalance can impact the knee articular cartilage status and can result in adverse clinical outcomes.➤ Cartilage preservation procedures in the knee will not result in optimal outcomes if there is joint malalignment, meniscal deficiency, or ligamentous instability.➤ Lower-extremity varus or valgus malalignment is a risk factor for the failure of an anterior cruciate ligament (ACL) reconstruction. It represents an indication for a high tibial osteotomy or distal femoral osteotomy in the setting of failed ACL reconstruction, and may even be considered in patients who have an initial ACL injury and severe malalignment.➤ An elevated posterior tibial slope increases the risk of failure of ACL reconstruction, whereas a decreased posterior tibial slope increases the risk of failure of posterior cruciate ligament reconstruction.

Biomechanical Analysis of Tibial Motion and ACL Graft Forces After ACLR With and Without LET at Varying Tibial Slopes.

BACKGROUND: Lateral extra-articular tenodesis (LET) is being performed more frequently with anterior cruciate ligament (ACL) reconstruction (ACLR) to decrease graft failure rates. The posterior tibial slope (PTS) affects ACL graft failure rates. The effect of ACLR + LET on tibial motion and graft forces with increasing PTS has not been elucidated. HYPOTHESIS: LET would decrease anterior tibial translation (ATT), tibial rotation, and ACL graft force versus ACLR alone with increasing tibial slope throughout knee range of motion. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve fresh-frozen cadaveric knees (mean donor age, 40.5 years; all female) were tested in 4 conditions (intact, ACL cut, ACLR, and ACLR + LET) with varying PTSs (5°, 10°, 15°, and 20°) at 3 flexion angles (0°, 30°, and 60°). Specimens were mounted to a load frame that applied a 500-N axial load with 1 N·m of internal rotation (IR) torque. The amount of tibial translation, IR, and graft force was measured. RESULTS: Increasing PTS revealed a linear and significant increase in graft force at all flexion angles. LET reduced graft force by 8.3% (-5.8 N) compared with ACLR alone at 30° of flexion. At the same position, slope reduction resulted in reduced graft force by 17% to 22% (-12.3 to -15.2 N) per 5° of slope correction, with a 46% (-40.7 N) reduction seen from 20° to 5° of slope correction. For ATT, ACLR returned tibial translation to preinjury levels, as did ACLR + LET at all flexion angles, except full extension, where ACLR + LET reduced ATT by 2.5 mm compared with the intact state (P = .019). CONCLUSION: Increased PTS was confirmed to increase graft forces linearly. Although ACLR + LET reduced graft force compared with ACLR alone, slope reduction had a larger effect across all testing conditions. No other clinically significant differences were noted between ACLR with versus without LET in regard to graft force, ATT, or IR. CLINICAL RELEVANCE: Many authors have proposed LET in the setting of ACLR, revision surgery, hyperlaxity, high-grade pivot shift, and elevated PTS, but the indications remain unclear. The biomechanical performance of ACLR + LET at varying PTSs may affect daily practice and provide clarity on these indications.

Effects of Lateral Opening-Wedge Distal Femoral Osteotomy on Meniscal Allograft Transplantation: A Biomechanical Evaluation.

Background: Lateral meniscal deficiency with valgus malalignment increases the rate of lateral compartment osteoarthritis. Lateral meniscal allograft transplantation (LMAT) with a concomitant varus-producing opening-wedge distal femoral osteotomy (DFO) is an option yet to be evaluated biomechanically. Purpose/Hypothesis: The purpose of this study was to clarify the biomechanical effects of the realignment procedure in the setting of LMAT. We hypothesized that (1) given the dependence of the lateral compartment on the lateral meniscus, a DFO and increasing degrees of varus would be insufficient to restore lateral compartment pressures to normal from a lateral meniscus-deficient state, and that (2) LMAT would restore lateral compartment pressures to the intact state while DFO would decrease lateral compartment pressures for any given state of the meniscus. Study Design: Controlled laboratory study. Methods: Ten cadaveric knees underwent opening-wedge varus-producing DFO secured by an external fixator. Anatomic alignment was standardized to 6° of mechanical valgus, and each joint was tested in full extension. Submeniscal placement of thin film pressure sensors allowed for the recording of contact pressure, peak contact pressure, and contact area. The specimens were loaded on a biaxial dynamic testing machine with loading angles between 9° valgus and 6° varus of mechanical alignment. Conditions tested included intact meniscus, meniscal deficiency, and meniscal transplantation. Results: Isolated varus-producing DFO to 6° in the meniscus-deficient state failed to restore joint pressures and contact areas to the intact state, with significant changes in mean contact pressure (175%), mean peak contact pressure (135%), and contact area (-41%) (all P < .05 vs intact), while LMAT restored all outcome measures (all P > .05 compared with intact). After LMAT, every additional 1° of DFO correction contributed to a decrease in the mean contact pressure, peak pressure, and contact area of 5.6% (-0.0479 N/mm2), 5.9% (-0.154 N/mm2), and 1.4% (-6.99 mm2) for the lateral compartment and 7.3% (+0.034 N/mm2), 12.6% (+0.160 N/mm2), and 4.3% (+20.53 mm2) for the medial compartment, respectively. Conclusion: Isolated DFO was inadequate to restore load distribution in meniscus-deficient knees, while concomitant LMAT restored near normal forces and improved the lateral compartment biomechanical profile. Clinical Relevance: Our findings support the concomitant use of LMAT and varus-producing DFO in the setting of lateral meniscal deficiency with valgus malalignment. This study provides tools for the orthopaedic surgeon to individualize the correction for each patient.

Rate of Conversion to Matrix-Induced Autologous Chondrocyte Implantation After a Biopsy: A Multisurgeon Study.

Background: Autologous chondrocyte implantation (ACI) and matrix-induced autologous chondrocyte implantation (MACI) are performed to treat focal chondral defects (FCDs); both are 2-step procedures involving a biopsy, followed by transplantation. There is little published research evaluating ACI/MACI in patients who undergo a biopsy alone. Purpose: To determine (1) the value of ACI/MACI cartilage biopsies and concomitant procedures in patients with FCDs of the knee and (2) the conversion rate to cartilage transplantation as well as the rate of reoperation. Study Design: Case series; Level of evidence, 4. Methods: A retrospective review was performed of 46 patients (63% female) who underwent a MACI (or ACI) biopsy between January 2013 and January 2018. Preoperative data, intraoperative data, and postoperative outcomes were assessed at a minimum of 2 years after the biopsy. The conversion rate from a biopsy to transplantation and the reoperation rate were calculated and analyzed. Results: Among the 46 patients included, 17 (37.0%) underwent subsequent surgery, with only 12 undergoing cartilage restoration surgery, for an overall transplantation rate of 26.1%. Of these 12 patients, 9 underwent MACI/ACI, 2 underwent osteochondral allograft transplantation (OCA), and 1 underwent particulated juvenile articular cartilage implantation at 7.2 ± 7.5 months after the biopsy. The reoperation rate was 16.7% (1 patient after MACI/ACI and 1 patient after OCA) at 13.5 ± 2.3 months after transplantation. Conclusion: Arthroscopic surgery with debridement, chondroplasty, loose body removal, meniscectomy/meniscal repair, and other treatment approaches of knee compartment abnormalities at the time of a biopsy appeared to be sufficient in improving function and reducing pain in patients with knee FCDs.

Direct measurement of three-dimensional forces at the medial meniscal root: A validation study.

The posterior medial meniscal root (PMMR) experiences variable and multiaxial forces during loading. Current methods to measure these forces are limited and fail to adequately characterize the loads in all three dimensions at the root. Our novel technique resolved these limitations with the installation of a 3-axis sensing construct that we hypothesized would not affect contact mechanics, would not impart extraneous loads onto the PMMR, would accurately measure forces, and would not deflect under joint loads. Six cadaveric specimens were dissected to the joint capsule and a sagittal-plane, femoral condyle osteotomy was performed to gain access to the root. The load sensor was placed below the PMMR and was validated across four tests. The contact mechanics test demonstrated a contact area precision of 44 mm2 and a contact pressure precision of 5.0 MPa between the pre-installation and post-installation states. The tibial displacement test indicated an average bone plug displacement of < 1 mm in all directions. The load validation test exhibited average precision values of 0.7 N in compression, 0.5 N in tension, 0.3 N in anterior-posterior shear, and 0.3 N in medial-lateral shear load. The bone plug deflection test confirmed < 2 mm of displacement in any direction when placed under a load. This is the first study to successfully validate a technique for measuring both magnitude and direction of forces experienced at the PMMR. This validated method has applications for improving surgical repair techniques and developing safer rehabilitation and postoperative protocols that decrease root loads.

MR Imaging of Knee Cartilage Injury and Repair Surgeries.

Cartilage injuries are common and may predispose to early accelerated osteoarthritis. Magnetic resonance (MR) imaging is critical in the detection and characterization of acute and chronic cartilage injuries. Several surgical approaches including microfracture, osteochondral allografting, autologous osteochondral transfer system, and autologous chondrocyte implantation have been developed to treat cartilage lesions. The goals of these treatments include relief of symptoms, restoration of joint function, and delay of progression of osteoarthritis. Imaging evaluation by MR imaging plays a crucial role in diagnosis and surgical planning as well as monitoring for postoperative complications.

Meniscus Repair Part 1: Biology, Function, Tear Morphology, and Special Considerations.

Knowledge of anatomy and physiology of the meniscus is essential for appropriate treatment. The unique anatomy of the medial and lateral meniscus and blood supply play an important role in decision making. Controversy exists regarding the optimal treatment of meniscal tears including débridement, repair, root repair, and transplantation. The unique tear location and morphology thus plays an essential role in determination of appropriate treatment. Repair is generally advised in tear types with healing potential to preserve meniscal function and joint health.

Meniscus Repair Part 2: Technical Aspects, Biologic Augmentation, Rehabilitation, and Outcomes.

Multiple meniscal repair techniques exist, and successful healing and excellent patient outcomes have been reported with a variety of all-inside and open techniques. Increased awareness and recognition of root tears and meniscocapsular separations are topics of recent interest. The ideal treatment of these injuries remains uncertain, and definitive recommendations regarding their treatment are lacking. Postoperative protocols regarding weight bearing and range of motion are controversial and require future study. The role of biologics in the augmentation of meniscal repair remains unclear but promising. An evidence-based individualized approach for meniscal repair focusing on clinical outcomes and value is essential.

Minimum 2-Year Clinical Outcomes of Medial Meniscus Root Tears in Relation to Coronal Alignment.

BACKGROUND: The effect of coronal plane alignment on the outcomes of repairs of the medial meniscus root remains unclear. HYPOTHESIS: Increased preoperative varus alignment is associated with higher failure rates and lower patient-reported outcomes (PROs) after isolated repair of the medial meniscus root. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients aged 18 years or older who underwent arthroscopy-assisted repair of the medial posterior meniscus root over a 7-year period were included. The mechanical axis of the knee was measured preoperatively. Osteoarthritis was assessed radiographically preoperatively and at the final follow-up according to the Kellgren-Lawrence grading scale. Failure was defined as any patient having to undergo revision root repair, partial meniscectomy of the previously repaired meniscus, debridement, lysis of adhesions, or conversion to arthroplasty. RESULTS: A total of 53 patients (29 women, 24 men) with a mean age of 51.3 years were included in the follow-up analysis. The mean time of follow-up after surgery was 3.3 years (range, 22-77 months). Significant improvements were observed in all PROs analyzed. Decreased varus as measured by alignment percentage was correlated with baseline Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain (P = .023) and WOMAC Stiffness (P = .022). Alignment percentage was also significantly negatively correlated with postoperative WOMAC Stiffness (P = .005) and positively correlated with Lysholm (P = .003) and International Knee Documentation Committee (P = .009) scores. Higher baseline Kellgren-Lawrence grade was correlated with worse postoperative PROs (P < .05), except 12-Item Short Form Health Survey Mental Component Summary and satisfaction. Eight patients who underwent a concomitant high tibial osteotomy (HTO) achieved lower PROs in all scales analyzed, regardless of their alignment. When excluding patients who underwent HTO, postoperative Lysholm score (P = .004) and postoperative WOMAC Stiffness (p = 0.014) were inferior among the patients with >5° of varus. CONCLUSION: Lower extremity alignment closest to neutral correlated with improved PROs. Patients who underwent a concurrent HTO had worse PROs than those who did not undergo HTO.

Obesity and sex influence fatty infiltration of the rotator cuff: the Rotator Cuff Outcomes Workgroup (ROW) and Multicenter Orthopaedic Outcomes Network (MOON) cohorts.

BACKGROUND: Fatty infiltration (FI) is one of the most important prognostic factors for outcomes after rotator cuff surgery. Established risk factors include advancing age, larger tear size, and increased tear chronicity. A growing body of evidence suggests that sex and obesity are associated with FI; however, data are limited. METHODS: We recruited 2 well-characterized multicenter cohorts of patients with rotator cuff tears (Multicenter Orthopaedic Outcomes Network [MOON] cohort [n = 80] and Rotator Cuff Outcomes Workgroup [ROW] cohort [n = 158]). We used multivariable logistic regression to evaluate the relationship between body mass index (BMI) and the presence of FI while adjusting for the participant's age at magnetic resonance imaging, sex, and duration of shoulder symptoms, as well as the cross-sectional area of the tear. We analyzed the 2 cohorts separately and performed a meta-analysis to combine estimates. RESULTS: A total of 27 patients (33.8%) in the Multicenter Orthopaedic Outcomes Network (MOON) cohort and 57 patients (36.1%) in the Rotator Cuff Outcomes Workgroup (ROW) cohort had FI. When BMI < 25 kg/m2 was used as the reference category, being overweight was associated with a 2.37-fold (95% confidence interval [CI], 0.77-7.29) increased odds of FI and being obese was associated with a 3.28-fold (95% CI, 1.16-9.25) increased odds of FI. Women were 4.9 times (95% CI, 2.06-11.69) as likely to have FI as men. CONCLUSIONS: Among patients with rotator cuff tears, obese patients had a substantially higher likelihood of FI. Further research is needed to assess whether modifying BMI can alter FI in patients with rotator cuff tears. This may have significant clinical implications for presurgical surgical management of rotator cuff tears. Sex was also significantly associated with FI, with women having higher odds of FI than men. Higher odds of FI in female patients may also explain previously reported early suboptimal outcomes of rotator cuff surgery and higher pain levels in female patients as compared with male patients.

Shoulder Surgery as an Effective Treatment for Shoulder-Related Sleep Disturbance: A Systematic Review.

PURPOSE: The purpose of this systematic review is to evaluate the current literature in an effort to investigate sleep quality and disturbances and the association with clinical outcomes of patients undergoing shoulder surgery. METHODS: A systematic review of the PubMed, Embase, and Cochrane Library databases was performed according to PRISMA guidelines. All English-language literature reporting clinical outcomes and sleep quality and disturbance after shoulder surgery was reviewed by 2 independent reviewers. Outcomes assessed included patient-reported outcomes (PROs) and sleep quality. Specific PROs included the Pittsburgh Sleep Quality Index (PSQI), Visual Analog Scale (VAS) for pain, Simple Shoulder Test (SST), University of California Los Angeles (UCLA) Shoulder Rating Scale, and American Shoulder and Elbow Surgeons Score (ASES). Study methodology was assessed using the Modified Coleman Methodology Score. Descriptive statistics are presented. RESULTS: Sixteen studies (11 level IV, 2 level III, 3 level II) with a total of 2748 shoulders were included (age, 12-91 years; follow-up, 0.25-132 months). In total, 2198 shoulders underwent arthroscopic rotator cuff repair (RCR), 131 shoulders underwent arthroscopic capsular release, 372 shoulders underwent total shoulder arthroplasty (TSA), 18 shoulders underwent comprehensive arthroscopic management, and 29 shoulders underwent sternoclavicular joint procedures. All shoulder surgeries improved self-reported sleep and PROs from before to after surgery. In RCR patients, PSQI scores were significantly associated with VAS scores, SST scores (r = 0.453, r = -0.490, P < .05, respectively), but not significantly associated with UCLA Shoulder rating scale or the ASES scores (r = 0.04, r = 0.001, P > .05, respectively). In TSA patients, PSQI scores were significantly associated with ASES scores (r = -0.08, P < .05). All 4 RCR studies and 1 TSA study using PSQI found significant improvements in mean PSQI scores within 6 to 24 months (P < .05). CONCLUSIONS: Surgical intervention for rotator cuff tear and glenohumeral osteoarthritis significantly improves self-reported sleep in patients with shoulder pain. However, there remains a dearth of available studies assessing the effects of surgical intervention for adhesive capsulitis, sternoclavicular joint instability, and sternoclavicular osteoarthritis on sleep. Future studies should use sleep-specific PROs and quantitative measures of sleep to further elucidate the relationship between sleep and the effect of shoulder surgery. LEVEL OF EVIDENCE: Level IV, systematic review of Level II-IV studies.

Knotted Transosseous-Equivalent Technique for Rotator Cuff Repair Shows Superior Biomechanical Properties Compared With a Knotless Technique: A Systematic Review and Meta-analysis.

PURPOSE: To compare the biomechanical properties of the knotted versus knotless transosseous-equivalent (TOE) techniques for rotator cuff repair (RCR). METHODS: A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using PubMed, Embase, and the Cochrane Library to identify studies that compared the biomechanical properties of knotted and knotless TOE RCR techniques. The search phrase used was as follows: (Double Row) AND (rotator cuff) AND (repair) AND (biomechanical). Evaluated properties included ultimate load to failure, cyclic displacement, stiffness, footprint characteristics, and failure mode. RESULTS: Eight studies met the inclusion criteria, including a total of 67 specimens in each group. Of 6 studies reporting on ultimate load to failure, 4 found tendons repaired with the knotted TOE technique to experience significantly higher ultimate load to failure compared with knotless TOE repairs (knotted range, 323.5-549.0 N; knotless range, 166.0-416.8 N; P < .05). Of 6 studies reporting on failure stiffness, 2 found knotted TOE repairs to have significantly higher failure stiffness compared with knotless TOE repairs (knotted range, 30.0-241.8 N/mm; knotless range, 28.0-182.5 N/mm; P < .05), whereas 1 study found significantly higher failure stiffness in knotless TOE repairs compared with knotted TOE repairs (P = .039). Cyclic gap formation favored the knotted TOE group in 2 of 3 studies (knotted range, 0.6-5.2 mm; knotless range, 0.4-9.1 mm; P < .05). The most common mode of failure in both groups was suture tendon tear. CONCLUSIONS: On the basis of the included cadaveric studies, rotator cuff tendons repaired via the knotted TOE technique display superior time-zero biomechanical properties, including greater ultimate load to failure, compared with rotator cuffs repaired via the knotless TOE technique. Suture tearing through the tendon remains a common failure method for both techniques. CLINICAL RELEVANCE: The results of this systematic review provide helpful insight into the biomechanical differences between 2 popular techniques for RCR. Although these results should be carefully considered by surgeons who are using either of these techniques in the operating room, they should not be mistaken for direct clinical applicability because cadaveric studies may not directly correlate to clinical outcomes.

Arthroscopic Segmental Medial Meniscus Allograft Transplant Using Three Fixation Techniques.

Partial meniscectomy or failed meniscus repair can lead to pain, dysfunction, and cartilage degradation due to increased contact forces. Meniscus transplantation can lead to favorable outcomes and cartilage preservation with careful patient selection. Limited data exist on segmental meniscus allograft transplantation, with promising results using synthetic grafts and early animal and biomechanical studies on segmental allograft transplantation, showing similar results to full meniscus allograft transplantation. This article presents a technique for arthroscopic segmental medial meniscus allograft transplant and a brief review of the literature.

Effect of Passing Plays on Injury Rates in the National Football League.

ABSTRACT: Burke, J, Geller, JS, Perez, JR, Naik, K, Vidal, AF, Baraga, MG, and Kaplan, LD. The effect of passing plays on injury rates in the national football league. J Strength Cond Res 35(12S): S1-S4, 2021-The National Football League (NFL) has one of the highest all-cause injury rates in sports, yet our understanding of extrinsic injury risk factors is limited. The objective of this study was to assess the effect of play type on injury incidence in the NFL. We obtained data for every regular season game played during the 2013-2016 seasons from the official NFL game books. There were 2,721 in-game injuries during the 4 seasons examined, with an overall rate of 1.33 injuries per team per game. For statistical analysis, p < 0.05 was considered significant. Passing plays conferred significantly higher odds of injury than running plays (odds ratio [OR] 1.4, 95% confidence interval [CI]: 1.3-1.5, p < 0.0001). This primarily stems from increased risks in quarterbacks (OR 6.9, 95% CI: 3.6-13.3, p < 0.0001), receivers (OR 5.0, 95% CI: 3.7-6.6, p < 0.0001), and defensive backs (OR 2.3, 95% CI: 1.9-2.7, p < 0.0001). Our study suggests that passing plays confer a greater risk of overall injuries in the NFL when compared with running plays, specifically regarding concussions and core or trunk injuries.

Anterior Cruciate Ligament Reconstruction With Concomitant Meniscal Repair: Is Graft Choice Predictive of Meniscal Repair Success?

BACKGROUND: When meniscal repair is performed during anterior cruciate ligament (ACL) reconstruction (ACLR), the effect of ACL graft type on meniscal repair outcomes is unclear. HYPOTHESIS: The authors hypothesized that meniscal repairs would fail at the lowest rate when concomitant ACLR was performed with bone--patellar tendon--bone (BTB) autograft. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who underwent meniscal repair at primary ACLR were identified from a longitudinal, prospective cohort. Meniscal repair failures, defined as any subsequent surgical procedure addressing the meniscus, were identified. A logistic regression model was built to assess the association of graft type, patient-specific factors, baseline Marx activity rating score, and meniscal repair location (medial or lateral) with repair failure at 6-year follow-up. RESULTS: A total of 646 patients were included. Grafts used included BTB autograft (55.7%), soft tissue autograft (33.9%), and various allografts (10.4%). We identified 101 patients (15.6%) with a documented meniscal repair failure. Failure occurred in 74 of 420 (17.6%) isolated medial meniscal repairs, 15 of 187 (8%) isolated lateral meniscal repairs, and 12 of 39 (30.7%) of combined medial and lateral meniscal repairs. Meniscal repair failure occurred in 13.9% of patients with BTB autografts, 17.4% of patients with soft tissue autografts, and 19.4% of patients with allografts. The odds of failure within 6 years of index surgery were increased more than 2-fold with allograft versus BTB autograft (odds ratio = 2.34 [95% confidence interval, 1.12-4.92]; P = .02). There was a trend toward increased meniscal repair failures with soft tissue versus BTB autografts (odds ratio = 1.41 [95% confidence interval, 0.87-2.30]; P = .17). The odds of failure were 68% higher with medial versus lateral repairs (P < .001). There was a significant relationship between baseline Marx activity level and the risk of subsequent meniscal repair failure; patients with either very low (0-1 points) or very high (15-16 points) baseline activity levels were at the highest risk (P = .004). CONCLUSION: Meniscal repair location (medial vs lateral) and baseline activity level were the main drivers of meniscal repair outcomes. Graft type was ranked third, demonstrating that meniscal repairs performed with allograft were 2.3 times more likely to fail compared with BTB autograft. There was no significant difference in failure rates between BTB versus soft tissue autografts. REGISTRATION: NCT00463099 (ClinicalTrials.gov identifier).

Biomechanical Analysis of Segmental Medial Meniscal Transplantation in a Human Cadaveric Model.

BACKGROUND: Meniscal deficiency has been reported to increase contact pressures in the affected tibiofemoral joint, possibly leading to degenerative changes. Current surgical options include meniscal allograft transplantation and insertion of segmental meniscal scaffolds. Little is known about segmental meniscal allograft transplantation. PURPOSE: To evaluate the effectiveness of segmental medial meniscal allograft transplantation in the setting of partial medial meniscectomy in restoring native knee loading characteristics. STUDY DESIGN: Controlled laboratory study. METHODS: Ten fresh-frozen human cadaveric knees underwent central midbody medial meniscectomy and subsequent segmental medial meniscal allograft transplantation. Knees were loaded in a dynamic tensile testing machine to 1000 N for 20 seconds at 0°, 30°, 60°, and 90° of flexion. Four conditions were tested: (1) intact medial meniscus, (2) deficient medial meniscus, (3) segmental medial meniscal transplant fixed with 7 meniscocapsular sutures, and (4) segmental medial meniscal transplant fixed with 7 meniscocapsular sutures and 1 suture fixed through 2 bone tunnels. Submeniscal medial and lateral pressure-mapping sensors assessed mean contact pressure, peak contact pressure, mean contact area, and pressure mapping. Two-factor random-intercepts linear mixed effects models compared pressure and contact area measurements among experimental conditions. RESULTS: The meniscal-deficient state demonstrated a significantly higher mean contact pressure than all other testing conditions (mean difference, ≥0.35 MPa; P < .001 for all comparisons) and a significantly smaller total contact area as compared with all other testing conditions (mean difference, ≤140 mm2; P < .001 for all comparisons). There were no significant differences in mean contact pressure or total contact area among the intact, transplant, or transplant-with-tunnel groups or in any outcome measure across all comparisons in the lateral compartment. No significant differences existed in center of pressure and relative pressure distribution across testing conditions. CONCLUSION: Segmental medial meniscal allograft transplantation restored the medial compartment mean contact pressure and mean contact area to values measured in the intact medial compartment. CLINICAL RELEVANCE: Segmental medial meniscal transplantation may provide an alternative to full meniscal transplantation by addressing only the deficient portion of the meniscus with transplanted tissue. Additional work is required to validate long-term fixation strength and biologic integration.

Bilateral total shoulder arthroplasty: A systematic review of clinical outcomes.

BACKGROUND: The purpose of this study was to describe the clinical outcomes following bilateral total shoulder arthroplasty (TSA). METHODS: A systematic search of the PubMed, Embase, and Cochrane Library databases following PRISMA guidelines was performed. English-language literature published from 2010 to 2018 analyzing bilateral TSA (anatomic and/or reverse) with a minimum one-year follow-up was reviewed by two independent reviewers. Study quality was evaluated with the Modified Coleman Methodology Score and the methodological index for non-randomized studies score. RESULTS: Eleven studies (1 Level II, 3 Level III, 7 Level IV) with 292 patients were included. Two studies reported on bilateral anatomic TSA (n = 54), six reported on bilateral reverse TSA (RTSA; n = 168), two reported on anatomic TSA with contralateral RTSA (TSA/RTSA; n = 31), and one compared bilateral anatomic TSA (n = 26) and bilateral RTSA (n = 13). Among studies, mean revision rate ranged from 0% to 10.53% and mean complication rate ranged from 4.9% to 31.3%. At final follow-up, patients experienced significant overall improvements in range of motion and patient-reported outcome score measurements. However, bilateral anatomic TSA resulted in greater improvements in external rotation compared to bilateral RTSA. Overall patient satisfaction was 91.0%. CONCLUSION: The available data indicate that bilateral TSA allows for functional and pain improvements and result in high patient satisfaction. LEVEL OF EVIDENCE: IV.