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.

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.

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.

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.

Tibial Slope Can Be Maintained During Medial Opening-Wedge Proximal Tibial Osteotomy With Sagittally Oriented Hinge, Posterior Plate Position, and Knee Hyperextension: A Cadaveric Study.

PURPOSE: The purpose of this study is (1) to determine if, when optimizing modern techniques, medial opening-wedge osteotomies can effectively maintain tibial slope and (2) to determine how different magnitude coronal plane corrections affect tibial slope. METHODS: Proximal tibial osteotomies (PTOs) were performed on 10 fresh-frozen cadaveric knees leaving a consistent lateral hinge, using either a 5-mm or a 10-mm trapezoidal wedged osteotomy plate. Techniques including posterior plate placement; a trapezoidal, sloped plate; and knee hyperextension were used during plate fixation to help close the anterior osteotomy gap. Medial coronal proximal tibia angle and posterior tibial slope were measured preosteotomy, after a 5-mm implant, and after a 10-mm implant using true anteroposterior and lateral fluoroscopic images. Three independent observers performed all radiographic measurements, and intraclass correlation coefficients were calculated. RESULTS: The 5-mm and 10-mm osteotomy plates increased the coronal medial proximal tibia angle by a mean of 3.4° (range, 3.0°-3.7°) and 7.3° (range, 6.7°-7.7°), respectively. The 5-mm and 10-mm trapezoidal wedged osteotomy plates decreased the posterior tibial slope by a mean of 0.9° (range, 0.5°-1.2°) and 0.3° (range, 0°-0.6°), respectively. Intraobserver reliability was found to be high for both the coronal medial proximal tibia angle (intraclass correlation coefficient [ICC] = 0.897 [0.821-0.946]) and the tibial slope measurements (ICC = 0.761 [0.672-0.826]). CONCLUSIONS: When optimizing the medial opening-wedge proximal tibial osteotomy, including utilization of a sagittally oriented hinge, placement of a trapezoidal plate posteriorly, and fixation with knee hyperextension, posterior tibial slope can be maintained regardless of the degree of coronal correction. CLINICAL RELEVANCE: Tibial slope has a significant effect on cruciate ligament stress and a better understanding of coronal plane correction, and its effect on tibial slope is critical when performing proximal tibia osteotomies.

Joint Preservation Techniques for the Knee in 2020: The Utility of Biologics, Osteotomies, and Cartilage Restoration Procedures.

Joint preservation strategies in young, active patients are a challenge, particularly in those with combined cartilage and meniscal deficiency. Concomitant malalignment and/or ligamentous insufficiency are not uncommon and further add to the complex nature of these patients. In patients who require surgery, a complete treatment strategy must be developed and implemented because unaddressed pathology typically leads to poor outcomes over time. In addition to reconstructive procedures, biologic therapies both as nonsurgical treatments and surgical augments offer promise, but their indications and place in orthopaedics continue to evolve. A comprehensive approach to this difficult patient population, including understanding all underlying pathologies, the natural history of each condition, and the appropriate treatment for each pathology, is necessary for successful joint preservation treatment in the young and active population.

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 Injury at the Time of Anterior Tibial Spine Fracture in Young Patients: An Observational Cohort Study.

BACKGROUND: Anterior tibial spine fractures (ATSF) in the skeletally immature parallel anterior cruciate ligament (ACL) tears in adult patients, yet these injuries are generally regarded as mutually exclusive. Biomechanical analysis suggests that intrinsic ACL damage occurs during ATSF, and long-term clinical studies demonstrate residual anteroposterior knee laxity following ATSF. We aim to describe prevalence, demographics, and characteristics of pediatric patients who sustained ATSF with concomitant ACL injury. METHODS: We included 129 patients with ATSF over a 16-year period. Age, sex, injury mechanism, ATSF type, magnetic resonance imaging (MRI) evaluation, treatment modality, ACL injury, and concomitant meniscal/chondral injuries were analyzed. Concurrent ACL injury was confirmed either from MRI or intraoperatively. RESULTS: Nineteen percent (n=25) of ATSF patients had concomitant ACL injury, with ACL injury significantly more likely in type II or type III ATSF compared with type I ATSF (P=0.03). Patients with combined ATSF/ACL injury were significantly older (P=0.02) and more likely to be male (P=0.01). Mechanism of ATSF injury was not associated with ACL injury (P=0.83). Preoperative MRI had low sensitivity (0.09) for recognizing ACL injury at the time of ATSF relative to intraoperative assessment. Half of ATSF/ACL-injured patients had additional meniscal or chondral injury, with meniscal repair or debridement required in 37.5% of the type II ATSF/ACL injury. CONCLUSIONS: There are demographic characteristics, such as age (older) and sex (male), associated with a higher risk of concomitant ACL injury at the time of ATSF. Type II and type III ATSF patterns had a higher prevalence of ACL injury. MRI failed to correctly identify ACL injury at the time of ATSF. Concomitant ACL injury at the time of ATSF is highly prevalent in the skeletally immature, occurring in 19.4% of patients with ATSF. LEVEL OF EVIDENCE: Level IV-case series.

Epidemiology of Anterior Tibial Spine Fractures in Young Patients: A Retrospective Cohort Study of 122 Cases.

BACKGROUND: Historically, bicycle accidents were described as the most common mechanism for pediatric anterior tibial spine fractures (ATSFs). There is a paucity of current literature examining the demographic factors associated with these injuries. The purpose of this cohort study was to characterize the epidemiology of ATSFs presenting to a single tertiary referral pediatric hospital. METHODS: A consecutive cohort of 122 pediatric patients with ATSFs between 1996 and 2014 were reviewed. Radiographic variables, classification of fractures (Meyers and McKeever type), age, sex, height, weight, body mass index, and mechanism of injury were retrieved. Categories of mechanism of injury included organized sports (football, soccer, basketball, lacrosse, wrestling, and gymnastics), bicycling, outdoor sports (skiing, skateboarding, and sledding), fall, motor vehicle collision/pedestrian versus motor vehicle, and trampoline. RESULTS: Organized sports-related injuries represented the most common cause of ATSFs (36%). Other common mechanisms of injury included bicycle accidents (25%), outdoor sports (18%), and falls (11%). There was a higher proportion of males (69%) compared with females (31%). Males (mean age, 11.6 y) were significantly older than females (mean age, 9.8 y) (P=0.004). Younger patients (aged 11.5 y and below) were more likely to have displaced fractures (type III), whereas type I and type II were more common in patients above 11.5 years (P=0.02). Patients with fracture type I were significantly taller than patients with fracture type III. No other variables were found to differ significantly according to fracture severity, including sex, weight, and body mass index. CONCLUSIONS: To our knowledge, our study represents both the largest (n=122) and most up-to-date epidemiological ATSF study in pediatric patients. A higher rate of ATSF occurs due to organized sports rather than bicycling or motor vehicle collision. This 18-year data collection represents a change in the paradigm, and is likely multifactorial, including increased participation in youth sports and early sport specialization. LEVEL OF EVIDENCE: Level IV-retrospective, cohort study.

Current pain prescribing habits for common shoulder operations: a survey of the American Shoulder and Elbow Surgeons membership.

BACKGROUND: Orthopedic surgeons are among the highest prescribers of narcotic pills, and no guidelines currently exist for appropriate management of postoperative pain within this field. The purpose of this study was to gain understanding of the current pain management strategies used perioperatively and postoperatively among orthopedic shoulder surgeons. METHODS: Members of the American Shoulder and Elbow Surgeons were e-mailed an online survey regarding methods for managing pain in the perioperative and postoperative setting for total shoulder arthroplasty, labral and capsular stabilization procedures, and rotator cuff repair. Postoperative narcotic prescribing amounts were converted into oral morphine equivalents. RESULTS: The survey response rate was 25.8% (170/658), with >90% of surgeons reporting use of a standard pain management regimen in the perioperative and postoperative periods. A regional nerve block was used on the operative day by >80% of surgeons for all 3 procedures. Short-acting narcotics are prescribed for postoperative pain control by >85% of surgeons, with long-acting narcotics provided by <14%. More than 400 oral morphine equivalents of short-acting narcotic are prescribed by shoulder surgeons. Referral to a pain specialist or primary care physician is made after 12 weeks by 92.3% of surgeons if patients continue to require narcotic painkillers. CONCLUSION: The majority of shoulder surgeons use a standard pain management protocol in perioperative and postoperative settings. Regimens frequently include a regional nerve block, nonsteroidal anti-inflammatory drugs, and short-acting oral narcotics. Findings from this study provide guidelines on standard pain management strategies for common shoulder operations based on expert opinion.

2013 Neer Award: predictors of failure of nonoperative treatment of chronic, symptomatic, full-thickness rotator cuff tears.

BACKGROUND: The purpose of this study is to help define the indications for rotator cuff repair by identifying predictors of failure of nonoperative treatment. METHODS: A prospective, multicenter, cohort study design was used. All patients with full-thickness rotator cuff tears on magnetic resonance imaging were offered participation. Baseline data from this cohort were used to examine risk factors for failing a standard rehabilitation protocol. Patients who underwent surgery were defined as failing nonoperative treatment. A Cox proportional hazards model was fit to determinethe baseline factors that predicted failure. The dependent variable was time to surgery. The independent variables were tear severity and baseline patient factors: age, activity level, body mass index, sex, Single Assessment Numeric Evaluation score, visual analog scale score for pain, education, handedness, comorbidities, duration of symptoms, strength, employment, smoking status, and patient expectations. RESULTS: Of the 433 subjects in this study, 87 underwent surgery with 93% follow-up at 1 year and 88% follow-up at 2 years. The median age was 62 years, and 49% were female patients. Multivariate modeling, adjusted for the covariates listed previously, identified patient expectations regarding physical therapy (P < .0001) as the strongest predictor of surgery. Higher activity level (P = .011) and not smoking (P = .023) were also significant predictors of surgery. CONCLUSION: A patient's decision to undergo surgery is influenced more by low expectations regarding the effectiveness of physical therapy than by patient symptoms or anatomic features of the rotator cuff tear. As such, patient symptoms and anatomic features of the chronic rotator cuff tear may not be the best features to use when deciding on surgical intervention.

Incidence of meniscal injury and chondral pathology in anterior tibial spine fractures of children.

BACKGROUND: Pediatric avulsion fractures of the anterior tibial spine are injuries similar to anterior cruciate ligament injuries in adults. Sparse data exists on the association between anterior tibial spine fractures (ATSFs) and injury to the meniscus or cartilage of the knee joint in children. This research presents a retrospective review of clinical records, imaging, and operative reports to characterize the incidence of concomitant injury in cases of ATSFs in children. The purpose of this study was to better delineate the incidence of associated injuries in fractures of the anterior tibial spine in the pediatric population. METHODS: We identified 58 patients who sustained an ATSF and met inclusion criteria for this study between 1996 and 2011. The subjects were separated by the Myers and McKeever classification into type I, II, and III fractures, and each of these were subclassified by associated injury pattern. RESULTS: 59% of children with an ATSF had an associated soft tissue or other bony injury diagnosed by magnetic resonance imaging or arthroscopy. The most prevalent associated injuries were meniscal entrapment, meniscal tears, and chondral injury. We found no meniscal or chondral injury associated with type I fractures. Twenty-nine percent of type II injuries demonstrated meniscal entrapment, 33% showing meniscal tears. Seven percent demonstrated chondral injury. Forty-eight percent of type III fractures had entrapment, whereas 12% showed meniscal tears. Eight percent had a chondral injury. CONCLUSIONS: A majority (59%) of displaced ATSF had either concomitant meniscal, ligamentous, or chondral injury. This finding suggests that magnetic resonance imaging evaluation is an important aspect of the evaluation of these injuries, particularly in type II and type III patterns. To date, this study reports the largest number of patients to evaluate the specific question of concomitant injuries in ATSFs in the pediatric population. LEVEL OF EVIDENCE: Level IV.

The duration of symptoms does not correlate with rotator cuff tear severity or other patient-related features: a cross-sectional study of patients with atraumatic, full-thickness rotator cuff tears.

HYPOTHESIS: The purpose of this cross-sectional study is to determine whether the duration of symptoms influences the features seen in patients with atraumatic, full-thickness rotator cuff tears. Our hypothesis is that an increasing duration of symptoms will correlate with more advanced findings of rotator cuff tear severity on magnetic resonance imaging, worse shoulder outcome scores, more pain, decreased range of motion, and less strength. METHODS: We enrolled 450 patients with full-thickness rotator cuff tears in a prospective cohort study to assess the effectiveness of nonoperative treatment and factors predictive of success. The duration of patient symptoms was divided into 4 groups: 3 months or less, 4 to 6 months, 7 to 12 months, and greater than 12 months. Data collected at patient entry into the study included (1) demographic data, (2) history and physical examination data, (3) radiographic imaging data, and (4) validated patient-reported measures of shoulder status. Statistical analysis included a univariate analysis with the Kruskal-Wallis test and Pearson test to identify statistically significant differences in these features for different durations of symptoms. RESULTS: A longer duration of symptoms does not correlate with more severe rotator cuff disease. The duration of symptoms was not related to weakness, limited range of motion, tear size, fatty atrophy, or validated patient-reported outcome measures. CONCLUSIONS: There is only a weak relationship between the duration of symptoms and features associated with rotator cuff disease.

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.

Obesity is associated with muscle atrophy in rotator cuff tear.

Objective: The primary goal of this study is to evaluate the relationship between Body Mass Index (BMI) and muscle atrophy in individuals with rotator cuff tears. Methods: This study consists of patients with rotator cuff tears identified by MRI from two independent cohorts, the Rotator Cuff Outcomes Workgroup (ROW) and the Multicenter Orthopaedic Outcomes Network (MOON). Presence of atrophy (yes/no) and severity of atrophy (as an ordinal variable) were assessed on MRI by expert physicians. We used multivariable regression models to evaluate the relationship between BMI and muscle atrophy while adjusting for age and sex in each study, conducted sensitivity analyses for full-thickness tear and combined results using inverse variance-weighted meta-analysis. Results: A total of 539 patients (MOON=395, ROW=144) from the combined cohorts had MRI data available on muscle atrophy. Among these patients, 246 (46%) had atrophy of at least one of the muscles of the rotator cuff and 282 (52%) had full-thickness tears. In meta-analysis across both cohorts, each 5 kg/m2 increase in BMI was associated with a 21% (aOR=1.21, 95% CI=1.02, 1.43) increased odds of having muscle atrophy among individuals with any tear size, and 36% (aOR=1.36, 95% CI=1.01-1.81) increased odds among individuals with full-thickness tear. Conclusions: Higher BMI was associated with significantly higher odds of muscle atrophy in patiens with rotator cuff tears. More study is needed to unders1tand why and how this relationship exists, as well as whether interventions to reduce BMI may help improve outcomes for these patients. Level of Evidence: III.

Effectiveness of physical therapy in treating atraumatic full-thickness rotator cuff tears: a multicenter prospective cohort study.

PURPOSE: To assess the effectiveness of a specific nonoperative physical therapy program in treating atraumatic full-thickness rotator cuff tears using a multicenter prospective cohort study design. MATERIALS AND METHODS: Patients with atraumatic full-thickness rotator cuff tears who consented to enroll provided data via questionnaire on demographics, symptom characteristics, comorbidities, willingness to undergo surgery, and patient-related outcome assessments (Short Form 12 score, American Shoulder and Elbow Surgeons score, Western Ontario Rotator Cuff score, Single Assessment Numeric Evaluation score, and Shoulder Activity Scale). Physicians recorded physical examination and imaging data. Patients began a physical therapy program developed from a systematic review of the literature and returned for evaluation at 6 and 12 weeks. At those visits, patients could choose 1 of 3 courses: (1) cured (no formal follow-up scheduled), (2) improved (continue therapy with scheduled reassessment in 6 weeks), or (3) no better (surgery offered). Patients were contacted by telephone at 1 and 2 years to determine whether they had undergone surgery since their last visit. A Wilcoxon signed rank test with continuity correction was used to compare initial, 6-week, and 12-week outcome scores. RESULTS: The cohort consists of 452 patients. Patient-reported outcomes improved significantly at 6 and 12 weeks. Patients elected to undergo surgery less than 25% of the time. Patients who decided to have surgery generally did so between 6 and 12 weeks, and few had surgery between 3 and 24 months. CONCLUSION: Nonoperative treatment using this physical therapy protocol is effective for treating atraumatic full-thickness rotator cuff tears in approximately 75% of patients followed up for 2 years.

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.

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.

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.

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.