Causal relationships between pain, medical treatments, and knee osteoarthritis: A graphical causal model to guide analyses.

OBJECTIVE: Randomized controlled trials (RCTs) are a gold standard for estimating the benefits of clinical interventions, but their decision-making utility can be limited by relatively short follow-up time. Longer-term follow-up of RCT participants is essential to support treatment decisions. However, as time from randomization accrues, loss to follow-up and competing events can introduce biases and require covariate adjustment even for intention-to-treat effects. We describe a process for synthesizing expert knowledge and apply this to long-term follow-up of an RCT of treatments for meniscal tears in patients with knee osteoarthritis (OA). METHODS: We identified 2 post-randomization events likely to impact accurate assessment of pain outcomes beyond 5 years in trial participants: loss to follow-up and total knee replacement (TKR). We conducted literature searches for covariates related to pain and TKR in individuals with knee OA and combined these with expert input. We synthesized the evidence into graphical models. RESULTS: We identified 94 potential covariates potentially related to pain and/or TKR among individuals with knee OA. Of these, 46 were identified in the literature review and 48 by expert panelists. We determined that adjustment for 50 covariates may be required to estimate the long-term effects of knee OA treatments on pain. CONCLUSION: We present a process for combining literature reviews with expert input to synthesize existing knowledge and improve covariate selection. We apply this process to the long-term follow-up of a randomized trial and show that expert input provides additional information not obtainable from literature reviews alone.

The Effect of Aspiration and Corticosteroid Injection After ACL Injury on Postoperative Infection Rate.

BACKGROUND: Injecting bioactive substances into the knee is common in orthopaedic practice, and recently it has been shown to mitigate risk factors for posttraumatic osteoarthritis. Therefore, understanding the influence of these injections on postoperative infection rate is imperative. HYPOTHESIS: Postinjury aspiration and corticosteroid injection (CSI) of the knee before anterior cruciate ligament (ACL) reconstruction (ACLR) would not increase the risk of postoperative infection. STUDY DESIGN: Cohort Study; Level of evidence, 3. METHODS: All patients between the ages of 10 and 65 years who underwent primary bone-patellar tendon-bone ACLR by 1 fellowship-trained sports medicine orthopaedic surgeon between January 1, 2011, and September 8, 2020, at 1 of 2 major academic centers were evaluated for inclusion. A total of 693 patients were included, with 273 patients receiving postinjury and preoperative aspiration and CSI. A postoperative infection was defined as a patient returning to the operating room for an intra-articular washout. The intervals-measured in days-between the CSI and ACLR and between ACLR and the final follow-up were recorded. To further evaluate the infection risk in each cohort (total cohort; aspiration and injection cohort; no aspiration and injection cohort), the upper 95% confidence bound for the infection risk was calculated for each cohort. RESULTS: There were no postoperative infections in the 693 patients included in this study. The upper 95% confidence bounds were 0.4%, 1.1%, and 0.7% for the total cohort, the cohort that underwent aspiration and injection, and the cohort that did not, respectively. The median number of days between the surgical date and that of the aspiration and injection was 34 days, and the mean follow-up for the entire cohort was 337.4 days (95% CI, 307.6-367.3). CONCLUSION: Postinjury and preoperative aspiration and CSI is a safe intervention that can be used before ACLR. Future studies with larger sample sizes, longer patient follow-ups, and multiple surgeons would be helpful to both better understand infection risk and better identify the influence of CSI on preventing posttraumatic osteoarthritis.

Factors Associated With Humeral Avulsion of Glenohumeral Ligament Lesions in Patients With Anterior Shoulder Instability: An Analysis of the MOON Shoulder Instability Cohort.

Background: Humeral avulsion of the glenohumeral ligament (HAGL) lesions are an uncommon cause of anterior glenohumeral instability and may occur in isolation or combination with other pathologies. As HAGL lesions are difficult to detect via magnetic resonance imaging (MRI) and arthroscopy, they can remain unrecognized and result in continued glenohumeral instability. Purpose: To compare patients with anterior shoulder instability from a large multicenter cohort with and without a diagnosis of a HAGL lesion and identify preoperative physical examination findings, patient-reported outcomes, imaging findings, and surgical management trends associated with HAGL lesions. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Patients with anterior glenohumeral instability who underwent surgical management between 2012 and 2020 at 11 orthopaedic centers were enrolled. Patients with HAGL lesions identified intraoperatively were compared with patients without HAGL lesions. Preoperative characteristics, physical examinations, imaging findings, intraoperative findings, and surgical procedures were collected. The Student t test, Kruskal-Wallis H test, Fisher exact test, and chi-square test were used to compare groups. Results: A total of 21 HAGL lesions were identified in 915 (2.3%) patients; approximately one-third (28.6%) of all lesions were visualized intraoperatively but not identified on preoperative MRI. Baseline characteristics did not differ between study cohorts. Compared with non-HAGL patients, HAGL patients were less likely to have a Hill-Sachs lesion (54.7% vs 28.6%; P = .03) or an anterior labral tear (87.2% vs 66.7%; P = .01) on preoperative MRI and demonstrated increased external rotation when their affected arm was positioned at 90° of abduction (85° vs 90°; P = .03). Additionally, HAGL lesions were independently associated with an increased risk of undergoing an open stabilization surgery (odds ratio, 74.6 [95% CI, 25.2-221.1]; P < .001). Conclusion: Approximately one-third of HAGL lesions were missed on preoperative MRI. HAGL patients were less likely to exhibit preoperative imaging findings associated with anterior shoulder instability, such as Hill-Sachs lesions or anterior labral pathology. These patients underwent open procedures more frequently than patients without HAGL lesions.

Predictors of Return to Activity at 2 Years After Anterior Cruciate Ligament Reconstruction Among Patients With High Preinjury Marx Activity Scores: A MOON Prospective Cohort Study.

BACKGROUND: Predictors of return to activity after anterior cruciate ligament reconstruction (ACLR) among patients with relatively high preinjury activity levels remain poorly understood. PURPOSE/HYPOTHESIS: The purpose of this study was to identify predictors of return to preinjury levels of activity after ACLR, defined as achieving a Marx activity score within 2 points of the preinjury value, among patients with Marx activity scores of 12 to 16 who had been prospectively enrolled in the Multicenter Orthopaedic Outcomes Network (MOON) cohort. We hypothesized that age, sex, preinjury activity level, meniscal injuries and/or procedures, and concurrent articular cartilage injuries would predict return to preinjury activity levels at 2 years after ACLR. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: All unilateral ACLR procedures from 2002 to 2008 performed in patients enrolled in the MOON, with preinjury Marx activity scores ranging from 12 to 16, were evaluated with a specific focus on return to preinjury activity levels at 2 years postoperatively. Return to activity was defined as a Marx activity score within 2 points of the preinjury value. The proportion of patients able to return to preinjury activity levels was calculated, and multivariable modeling was performed to identify risk factors for patients' inability to return to preinjury activity levels. RESULTS: A total of 1188 patients were included in the final analysis. The median preinjury Marx activity score was 16 (interquartile range, 12-16). Overall, 466 patients (39.2%) were able to return to preinjury levels of activity, and 722 patients (60.8%) were not able to return to preinjury levels of activity. Female sex, smoking at the time of ACLR, fewer years of education, lower 36-Item Short Form Health Survey Mental Component Summary scores, and higher preinjury Marx activity scores were predictive of patients' inability to return to preinjury activity levels. Graft type, revision ACLR, the presence of medial and/or lateral meniscal injuries, a history of meniscal surgery, the presence of articular cartilage injuries, a history of articular cartilage treatment, and the presence of high-grade knee laxity were not predictive of a patient's ability to return to preinjury activity level. CONCLUSION: At 2 years after ACLR, most patients with high preinjury Marx activity scores did not return to their preinjury level of activity. The higher the preinjury Marx activity score that a patient reported at the time of enrollment, the less likely he/she was able to return to preinjury activity level. Smoking and lower mental health at the time of ACLR were the only modifiable risk factors in this cohort that predicted an inability to return to preinjury activity levels. Continued effort and investigation are required to maximize functional recovery after ACLR in patients with high preinjury levels of activity.

Radiographic Changes Five Years After Treatment of Meniscal Tear and Osteoarthritic Changes.

OBJECTIVE: Meniscal tear in persons aged ≥45 years is typically managed with physical therapy (PT), and arthroscopic partial meniscectomy (APM) is offered to those who do not respond. Prior studies suggest APM may be associated with greater progression of radiographic changes. METHODS: We assessed changes between baseline and 60 months in the Kellgren-Lawrence (KL) grade and OARSI radiographic score (including subscores for joint space narrowing and osteophytes) in subjects aged 45-85 years enrolled into a seven-center randomized trial comparing outcomes of APM with PT for meniscal tear, osteoarthritis changes, and knee pain. The primary analysis classified subjects according to treatment received. To balance APM and PT groups, we developed a propensity score and used inverse probability weighting (IPW). We imputed a 60-month change in the OARSI score for subjects who underwent total knee replacement (TKR). In a sensitivity analysis, we classified subjects by randomization group. RESULTS: We analyzed data from 142 subjects (100 APM, 42 PT). The mean ± SD weighted baseline OARSI radiographic score was 3.8 ± 3.5 in the APM group and 4.0 ± 4.9 in the PT group. OARSI scores increased by a mean of 4.1 (95% confidence interval [95% CI] 3.5-4.7) in the APM group and 2.4 (95% CI 1.7-3.2) in the PT group (P < 0.001) due to changes in the osteophyte component. We did not observe statistically significant differences in the KL grade. Sensitivity analyses yielded similar findings to the primary analysis. CONCLUSION: Subjects treated with APM had greater progression in the OARSI score because of osteophyte progression but not in the KL grade. The clinical implications of these findings require investigation.

Structural and functional changes of deep layer pyramidal neurons surrounding microelectrode arrays implanted in rat motor cortex.

Devices capable of recording or stimulating neuronal signals have created new opportunities to understand normal physiology and treat sources of pathology in the brain. However, it is possible that the tissue response to implanted electrodes may influence the nature of the signals detected or stimulated. In this study, we characterized structural and functional changes in deep layer pyramidal neurons surrounding silicon or polyimide-based electrodes implanted in the motor cortex of rats. Devices were captured in 300 µm-thick tissue slices collected at the 1 or 6 week time point post-implantation, and individual neurons were assessed using a combination of whole-cell electrophysiology and 2-photon imaging. We observed disrupted dendritic arbors and a significant reduction in spine densities in neurons surrounding devices. These effects were accompanied by a decrease in the frequency of spontaneous excitatory post-synaptic currents, a reduction in sag amplitude, an increase in spike frequency adaptation, and an increase in filopodia density. We hypothesize that the effects observed in this study may contribute to the signal loss and instability that often accompany chronically implanted electrodes. STATEMENT OF SIGNIFICANCE: Implanted electrodes in the brain can be used to treat sources of pathology and understand normal physiology by recording or stimulating electrical signals generated by local neurons. However, a foreign body response following implantation undermines the performance of these devices. While several studies have investigated the biological mechanisms of device-tissue interactions through histology, transcriptomics, and imaging, our study is the first to directly interrogate effects on the function of neurons surrounding electrodes using single-cell electrophysiology. Additionally, we provide new, detailed assessments of the impacts of electrodes on the dendritic structure and spine morphology of neurons, and we assess effects for both traditional (silicon) and newer polymer electrode materials. These results reveal new potential mechanisms of electrode-tissue interactions.

The Corticosteroid Meniscectomy Trial of Extended-Release Triamcinolone Injection After Arthroscopic Partial Meniscectomy: Protocol for a Double-Blind Randomized Controlled Trial.

Background: Meniscal tear in older adults often accompanies knee osteoarthritis and is commonly treated with arthroscopic partial meniscectomy (APM) when patients have persistent pain after a trial of physical therapy. Cross-sectional evidence suggests that synovitis is associated with baseline pain in this patient population, but little is known about the relationship between synovitis and postoperative recovery or progression of knee osteoarthritis. Purpose/Hypothesis: Intra-articular extended-release triamcinolone may reduce inflammation and thereby improve outcomes and slow disease progression. This article presents the rationale behind the Corticosteroid Meniscectomy Trial (CoMeT) and describes its study design and implementation strategies. Study Design: Randomized controlled trial. Methods: CoMeT is a 2-arm, 3-center, randomized placebo-controlled trial designed to establish the clinical efficacy of extended-release triamcinolone administered via intra-articular injection immediately after APM. The primary outcome is change in Knee injury and Osteoarthritis Outcome Score Pain subscore at 3-month follow-up. Synovial biopsy, joint fluid aspirate, and urine and blood sample analyses will examine the associations between various objective measures of baseline inflammation and pre- and postoperative outcome measures and clinical responses to triamcinolone intervention. Quantitative 3-T magnetic resonance imaging will evaluate cartilage and meniscal composition and 3-dimensional bone shape to detect early joint degeneration. Results: We discuss methodologic innovations and challenges. Conclusion: To our knowledge, this is the first randomized double-blind clinical trial that will analyze the effect of extended-release triamcinolone acetonide on pain, magnetic resonance imaging measures of structural change and effusion/synovitis, soluble biomarkers, and synovial tissue transcriptomics after APM.

Meniscal and Articular Cartilage Predictors of Outcome After Revision ACL Reconstruction: A 6-Year Follow-up Cohort Study.

BACKGROUND: Meniscal and chondral damage is common in the patient undergoing revision anterior cruciate ligament (ACL) reconstruction. PURPOSE: To determine if meniscal and/or articular cartilage pathology at the time of revision ACL surgery significantly influences a patient's outcome at 6-year follow-up. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients undergoing revision ACL reconstruction were prospectively enrolled between 2006 and 2011. Data collection included baseline demographics, surgical technique, pathology, treatment, and scores from 4 validated patient-reported outcome instruments: International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Marx Activity Rating Scale. Patients were followed up at 6 years and asked to complete the identical set of outcome instruments. Regression analysis assessed the meniscal and articular cartilage pathology risk factors for clinical outcomes 6 years after revision ACL reconstruction. RESULTS: An overall 1234 patients were enrolled (716 males, 58%; median age, 26 years). Surgeons reported the pathology at the time of revision surgery in the medial meniscus (45%), lateral meniscus (36%), medial femoral condyle (43%), lateral femoral condyle (29%), medial tibial plateau (11%), lateral tibial plateau (17%), patella (30%), and trochlea (21%). Six-year follow-up was obtained on 79% of the sample (980/1234). Meniscal pathology and articular cartilage pathology (medial femoral condyle, lateral femoral condyle, lateral tibial plateau, trochlea, and patella) were significant drivers of poorer patient-reported outcomes at 6 years (IKDC, KOOS, WOMAC, and Marx). The most consistent factors driving outcomes were having a medial meniscal excision (either before or at the time of revision surgery) and patellofemoral articular cartilage pathology. Six-year Marx activity levels were negatively affected by having either a repair/excision of the medial meniscus (odds ratio range, 1.45-1.72; P≤ .04) or grade 3-4 patellar chondrosis (odds ratio, 1.72; P = .04). Meniscal pathology occurring before the index revision surgery negatively affected scores on all KOOS subscales except for sports/recreation (P < .05). Articular cartilage pathology significantly impaired all KOOS subscale scores (P < .05). Lower baseline outcome scores, higher body mass index, being a smoker, and incurring subsequent surgery all significantly increased the odds of reporting poorer clinical outcomes at 6 years. CONCLUSION: Meniscal and chondral pathology at the time of revision ACL reconstruction has continued significant detrimental effects on patient-reported outcomes at 6 years after revision surgery.

A Review of Evidence for Infection Reduction With Vancomycin-treated Anterior Cruciate Ligament Grafts.

Septic arthritis after anterior cruciate ligament (ACL) reconstruction is a rare but devastating complication. Several risk factors and known sources of infection have been identified in the literature. There is growing interest and supportive evidence for a targeted invention aimed at graft decontamination, which has led some surgeons to adopt the use of antibiotic solution soaks and/or wraps applied to ACL grafts before graft implantation in an attempt to reduce the risk of postoperative infection. Despite this, adoption of this technique remains relatively low among surgeons because of a variety of factors: (1) lack of awareness, (2) confusion over optimal protocols, (3) concern for graft viability and clinical outcomes, and (4) efforts to minimize the cost of surgery. However, recently published literature demonstrates notable risk reduction for infection, acceptable safety, no detrimental effect on clinical outcomes, and overall cost-effectiveness with the use of vancomycin graft soaks and wraps. Currently, there is a lack of consensus for clinical protocols, and the protocol that is most efficacious remains unclear. The purpose of this review article was to present the current evidence for ACL graft treatment with vancomycin for the prevention of postoperative infection.

Descriptive Characteristics and Outcomes of Patients Undergoing Revision Anterior Cruciate Ligament Reconstruction With and Without Tunnel Bone Grafting.

BACKGROUND: Lytic or malpositioned tunnels may require bone grafting during revision anterior cruciate ligament reconstruction (rACLR) surgery. Patient characteristics and effects of grafting on outcomes after rACLR are not well described. PURPOSE: To describe preoperative characteristics, intraoperative findings, and 2-year outcomes for patients with rACLR undergoing bone grafting procedures compared with patients with rACLR without grafting. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A total of 1234 patients who underwent rACLR were prospectively enrolled between 2006 and 2011. Baseline revision and 2-year characteristics, surgical technique, pathology, treatment, and patient-reported outcome instruments (International Knee Documentation Committee [IKDC], Knee injury and Osteoarthritis Outcome Score [KOOS], Western Ontario and McMaster Universities Osteoarthritis Index, and Marx Activity Rating Scale [Marx]) were collected, as well as subsequent surgery information, if applicable. The chi-square and analysis of variance tests were used to compare group characteristics. RESULTS: A total of 159 patients (13%) underwent tunnel grafting-64 (5%) patients underwent 1-stage and 95 (8%) underwent 2-stage grafting. Grafting was isolated to the femur in 31 (2.5%) patients, the tibia in 40 (3%) patients, and combined in 88 patients (7%). Baseline KOOS Quality of Life (QoL) and Marx activity scores were significantly lower in the 2-stage group compared with the no bone grafting group (P≤ .001). Patients who required 2-stage grafting had more previous ACLRs (P < .001) and were less likely to have received a bone-patellar tendon-bone or a soft tissue autograft at primary ACLR procedure (P≤ .021) compared with the no bone grafting group. For current rACLR, patients undergoing either 1-stage or 2-stage bone grafting were more likely to receive a bone-patellar tendon-bone allograft (P≤ .008) and less likely to receive a soft tissue autograft (P≤ .003) compared with the no bone grafting group. At 2-year follow-up of 1052 (85%) patients, we found inferior outcomes in the 2-stage bone grafting group (IKDC score = 68; KOOS QoL score = 44; KOOS Sport/Recreation score = 65; and Marx activity score = 3) compared with the no bone grafting group (IKDC score = 77; KOOS QoL score = 63; KOOS Sport/Recreation score = 75; and Marx activity score = 7) (P≤ .01). The 1-stage bone graft group did not significantly differ compared with the no bone grafting group. CONCLUSION: Tunnel bone grafting was performed in 13% of our rACLR cohort, with 8% undergoing 2-stage surgery. Patients treated with 2-stage grafting had inferior baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting. Patients treated with 1-stage grafting had similar baseline and 2-year patient-reported outcomes and activity levels compared with patients not undergoing bone grafting.

Returning to Activity After Anterior Cruciate Ligament Revision Surgery: An Analysis of the Multicenter Anterior Cruciate Ligament Revision Study (MARS) Cohort at 2 Years Postoperative.

BACKGROUND: Patients with anterior cruciate ligament (ACL) revision report lower outcome scores on validated knee questionnaires postoperatively compared to cohorts with primary ACL reconstruction. In a previously active population, it is unclear if patient-reported outcomes (PROs) are associated with a return to activity (RTA) or vary by sports participation level (higher level vs. recreational athletes). HYPOTHESES: Individual RTA would be associated with improved outcomes (ie, decreased knee symptoms, pain, function) as measured using validated PROs. Recreational participants would report lower PROs compared with higher level athletes and be less likely to RTA. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: There were 862 patients who underwent a revision ACL reconstruction (rACLR) and self-reported physical activity at any level preoperatively. Those who did not RTA reported no activity 2 years after revision. Baseline data included patient characteristics, surgical history and characteristics, and PROs: International Knee Documentation Committee questionnaire, Marx Activity Rating Scale, Knee injury and Osteoarthritis Outcome Score, and the Western Ontario and McMaster Universities Osteoarthritis Index. A binary indicator was used to identify patients with same/better PROs versus worse outcomes compared with baseline, quantifying the magnitude of change in each direction, respectively. Multivariable regression models were used to evaluate risk factors for not returning to activity, the association of 2-year PROs after rACLR surgery by RTA status, and whether each PRO and RTA status differed by participation level. RESULTS: At 2 years postoperatively, approximately 15% did not RTA, with current smokers (adjusted odds ratio [aOR] = 3.3; P = .001), female patients (aOR = 2.9; P < .001), recreational participants (aOR = 2.0; P = .016), and those with a previous medial meniscal excision (aOR = 1.9; P = .013) having higher odds of not returning. In multivariate models, not returning to activity was significantly associated with having worse PROs at 2 years; however, no clinically meaningful differences in PROs at 2 years were seen between participation levels. CONCLUSION: Recreational-level participants were twice as likely to not RTA compared with those participating at higher levels. Within a previously active cohort, no RTA was a significant predictor of lower PROs after rACLR. However, among patients who did RTA after rACLR, approximately 20% reported lower outcome scores. Most patients with rACLR who were active at baseline improved over time; however, patients who reported worse outcomes at 2 years had a clinically meaningful decline across all PROs.

Return to Sports After Anterior Cruciate Ligament Reconstruction: Validity and Reliability of the SPORTS Score at 6 and 12 Months.

Background: The Subjective Patient Outcome for Return to Sports (SPORTS) score is a single-item scale that measures athletes' ability to return to their preinjury sport based on effort and performance. Purpose/Hypothesis: The purpose of this study was to examine the psychometric properties of the SPORTS score and a modified score within the first year after anterior cruciate ligament reconstruction (ACLR). The modified version replaced "same sport" with "any sport" in the answer choices. It was hypothesized that both versions of the SPORTS score would have acceptable floor and ceiling effects and internal responsiveness, moderate convergent validity, and excellent test-retest reliability. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Patients were recruited preoperatively from 2 academic medical centers. The authors collected responses to the 1-item SPORTS scores at 6 and 12 months after ACLR and the Tegner activity scale, Lysholm knee score, Knee injury and Osteoarthritis Outcome Score (KOOS)-sport/recreation subscale, and Marx activity rating scale preoperatively and 6 and 12 months after ACLR. Ceiling and floor effects and responsiveness were assessed using descriptive statistics and cross-tabulations, respectively, at both follow-up time points. Spearman correlations and intraclass correlation coefficients were used to examine convergent validity and test-retest reliability, respectively. Results: Follow-up rates at 6 and 12 months were 100% and 99%, respectively. Test-retest follow-up was 77%. Floor effects for the SPORTS scores were not observed, while ceiling effects at 12 months ranged from 38% to 40%. Cross-tabulation of the SPORTS scores showed that 64% to 66% of patients reported a change in their score from 6 to 12 months, with significant differences noted between the proportions that improved versus worsened for return to any sport. Convergent validity was observed at 6 and 12 months via moderate correlations with the Tegner, Lysholm, KOOS-sport/recreation, and Marx scores (r = 0.31 to 0.47). Fair to good test-retest reliability (intraclass correlation coefficient, 0.58 and 0.60) was found at 12 months after ACLR. Conclusion: The SPORTS score appears to be a reliable, responsive, and valid 1-item scale that can be used during the first year after ACLR. No differences in psychometric properties were found between the SPORTS score and the modified version.

Design Features and Rationale of the BEAR-MOON (Bridge-Enhanced ACL Restoration Multicenter Orthopaedic Outcomes Network) Randomized Clinical Trial.

BACKGROUND: BEAR (bridge-enhanced anterior cruciate ligament [ACL] restoration), a paradigm-shifting technology to heal midsubstance ACL tears, has been demonstrated to be effective in a single-center 2:1 randomized controlled trial (RCT) versus hamstring ACL reconstruction. Widespread dissemination of BEAR into clinical practice should also be informed by a multicenter RCT to demonstrate exportability and compare efficacy with bone--patellar tendon-bone (BPTB) ACL reconstruction, another clinically standard treatment. PURPOSE: To present the design and initial preparation of a multicenter RCT of BEAR versus BPTB ACL reconstruction (the BEAR: Multicenter Orthopaedic Outcomes Network [BEAR-MOON] trial). Design and analytic issues in planning the complex BEAR-MOON trial, involving the US National Institute of Arthritis and Musculoskeletal and Skin Diseases, the US Food and Drug Administration, the BEAR implant manufacturer, a data and safety monitoring board, and institutional review boards, can usefully inform both clinicians on the trial's strengths and limitations and future investigators on planning of complex orthopaedic studies. STUDY DESIGN: Clinical trial. METHODS: We describe the distinctive clinical, methodological, and operational challenges of comparing the innovative BEAR procedure with the well-established BPTB operation, and we outline the clinical motivation, experimental setting, study design, surgical challenges, rehabilitation, outcome measures, and planned analysis of the BEAR-MOON trial. RESULTS: BEAR-MOON is a 6-center, 12-surgeon, 200-patient randomized, partially blinded, noninferiority RCT comparing BEAR with BPTB ACL reconstruction for treating first-time midsubstance ACL tears. Noninferiority of BEAR relative to BPTB will be claimed if the total score on the International Knee Documentation Committee (IKDC) subjective knee evaluation form and the knee arthrometer 30-lb (13.61-kg) side-to-side laxity difference are both within respective margins of 16 points for the IKDC and 2.5 mm for knee laxity. CONCLUSION: Major issues include patient selection, need for intraoperative randomization and treatment-specific postoperative physical therapy regimens (because of fundamental differences in surgical technique, initial stability construct, and healing), and choice of noninferiority margins for short-term efficacy outcomes of a novel intervention with evident short-term advantages and theoretical, but unverified, long-term benefits on other dimensions.

Neither Residual Anterior Knee Laxity Up to 6 mm nor a Pivot Glide Predict Patient-Reported Outcome Scores or Subsequent Knee Surgery Between 2 and 6 Years After ACL Reconstruction.

BACKGROUND: A primary goal of anterior cruciate ligament reconstruction (ACLR) is to reduce pathologically increased anterior and rotational laxity of the knee, but the effects of residual laxity on patient-reported outcomes (PROs) after ACLR remain unclear. HYPOTHESIS: Increased residual laxity at 2 years postoperatively is predictive of a higher risk of subsequent ipsilateral knee surgery and decreases in PRO scores from 2 to 6 years after surgery. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: From a prospective multicenter cohort, 433 patients aged <36 years were identified at a minimum 2 years after primary ACLR. These patients underwent a KT-1000 arthrometer assessment and pivot-shift test and completed PRO assessments with the Knee injury and Osteoarthritis Outcome Score and International Knee Documentation Committee (IKDC) scores. Patients completed the same PROs at 6 years postoperatively, and any subsequent ipsilateral knee procedures during this period were recorded. Subsequent surgery risk and change in PROs from 2 to 6 years postoperatively were compared based on residual side-to-side KT-1000 arthrometer differences (<-1 mm, -1 to 2 mm, 2 to 6 mm, and >6 mm) in laxity at 2 years postoperatively. Multiple linear regression models were built to determine the relationship between 2-year postoperative knee laxity and 2- to 6-year change in PROs while controlling for age, sex, body mass index, smoking status, meniscal and cartilage status, and graft type. RESULTS: A total of 381 patients (87.9%) were available for follow-up 6 years postoperatively. There were no significant differences in risk of subsequent knee surgery based on residual knee laxity. Patients with a difference >6 mm in side-to-side anterior laxity at 2 years postoperatively were noted to have a larger decrease in PROs from 2 to 6 years postoperatively (P < .05). No significant differences in any PROs were noted among patients with a difference <6 mm in side-to-side anterior laxity or those with pivot glide (IKDC B) versus no pivot shift (IKDC A). CONCLUSION: The presence of a residual side-to-side KT-1000 arthrometer difference <6 mm or pivot glide at 2 years after ACLR is not associated with an increased risk of subsequent ipsilateral knee surgery or decreased PROs up to 6 years after ACLR. Conversely, patients exhibiting a difference >6 mm in side-to-side anterior laxity were noted to have significantly decreased PROs at 6 years after ACLR.

Association Between Graft Choice and 6-Year Outcomes of Revision Anterior Cruciate Ligament Reconstruction in the MARS Cohort.

BACKGROUND: Although graft choice may be limited in the revision setting based on previously used grafts, most surgeons believe that graft choice for anterior cruciate ligament (ACL) reconstruction is an important factor related to outcome. HYPOTHESIS: In the ACL revision setting, there would be no difference between autograft and allograft in rerupture rate and patient-reported outcomes (PROs) at 6-year follow-up. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Patients who had revision surgery were identified and prospectively enrolled in this cohort study by 83 surgeons over 52 sites. Data collected included baseline characteristics, surgical technique and pathology, and a series of validated PRO measures. Patients were followed up at 6 years and asked to complete the identical set of PRO instruments. Incidence of additional surgery and reoperation because of graft failure were also recorded. Multivariable regression models were used to determine the predictors (risk factors) of PROs, graft rerupture, and reoperation at 6 years after revision surgery. RESULTS: A total of 1234 patients including 716 (58%) men were enrolled. A total of 325 (26%) underwent revision using a bone-patellar tendon-bone (BTB) autograft; 251 (20%), soft tissue autograft; 289 (23%), BTB allograft; 302 (25%), soft tissue allograft; and 67 (5%), other graft. Questionnaires and telephone follow-up for subsequent surgery information were obtained for 809 (66%) patients, while telephone follow-up was only obtained for an additional 128 patients for the total follow-up on 949 (77%) patients. Graft choice was a significant predictor of 6-year Marx Activity Rating Scale scores (P = .024). Specifically, patients who received a BTB autograft for revision reconstruction had higher activity levels than did patients who received a BTB allograft (odds ratio [OR], 1.92; 95% CI, 1.25-2.94). Graft rerupture was reported in 5.8% (55/949) of patients by their 6-year follow-up: 3.5% (16/455) of patients with autografts and 8.4% (37/441) of patients with allografts. Use of a BTB autograft for revision resulted in patients being 4.2 times less likely to sustain a subsequent graft rupture than if a BTB allograft were utilized (P = .011; 95% CI, 1.56-11.27). No significant differences were found in graft rerupture rates between BTB autograft and soft tissue autografts (P = .87) or between BTB autografts and soft tissue allografts (P = .36). Use of an autograft was found to be a significant predictor of having fewer reoperations within 6 years compared with using an allograft (P = .010; OR, 0.56; 95% CI, 0.36-0.87). CONCLUSION: BTB and soft tissue autografts had a decreased risk in graft rerupture compared with BTB allografts. BTB autografts were associated with higher activity level than were BTB allografts at 6 years after revision reconstruction. Surgeons and patients should consider this information when choosing a graft for revision ACL reconstruction.

Articular Cartilage and Meniscus Predictors of Patient-Reported Outcomes 10 Years After Anterior Cruciate Ligament Reconstruction: A Multicenter Cohort Study.

BACKGROUND: Articular cartilage and meniscal damage are commonly encountered and often treated at the time of anterior cruciate ligament reconstruction (ACLR). Our understanding of how these injuries and their treatment relate to outcomes of ACLR is still evolving. HYPOTHESIS/PURPOSE: The purpose of this study was to assess whether articular cartilage and meniscal variables are predictive of 10-year outcomes after ACLR. We hypothesized that articular cartilage lesions and meniscal tears and treatment would be predictors of the International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS) (all 5 subscales), and Marx activity level outcomes at 10-year follow-up after ACLR. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 1. METHODS: Between 2002 and 2008, individuals with ACLR were prospectively enrolled and followed longitudinally using the IKDC, KOOS, and Marx activity score completed at entry, 2, 6, and 10 years. A proportional odds logistic regression model was built incorporating variables from patient characteristics, surgical technique, articular cartilage injuries, and meniscal tears and treatment to determine the predictors (risk factors) of IKDC, KOOS, and Marx outcomes at 10 years. RESULTS: A total of 3273 patients were enrolled (56% male; median age, 23 years at time of enrollment). Ten-year follow-up was obtained on 79% (2575/3273) of the cohort. Incidence of concomitant pathology at the time of surgery consisted of the following: articular cartilage (medial femoral condyle [MFC], 22%; lateral femoral condyle [LFC], 15%; medial tibial plateau [MTP], 4%; lateral tibial plateau [LTP], 11%; patella, 18%; trochlea, 8%) and meniscal pathology (medial, 37%; lateral, 46%). Variables that were predictive of poorer 10-year outcomes included articular cartilage damage in the patellofemoral (P < .01) and medial (P < .05) compartments and previous medial meniscal surgery (7% of knees; P < .04). Compared with no meniscal tear, a meniscal injury was not associated with 10-year outcomes. Medial meniscal repair at the time of ACLR was associated with worse 10-year outcomes for 2 of 5 KOOS subscales, while a medial meniscal repair in knees with grade 2 MFC chondrosis was associated with better outcomes on 2 KOOS subscales. CONCLUSION: Articular cartilage injury in the patellofemoral and medial compartments at the time of ACLR and a history of medial meniscal surgery before ACLR were associated with poorer 10-year ACLR patient-reported outcomes, but meniscal injury present at the time of ACLR was not. There was limited and conflicting association of medial meniscal repair with these outcomes.

Composite psychosocial risk based on the fear avoidance model in patients undergoing anterior cruciate ligament reconstruction: Cluster-based analysis.

OBJECTIVES: To examine associations between preoperative fear-avoidance model (FAM) risk subgroup status and patient expectation of surgical success with postoperative outcomes at 6 and 12 months after anterior cruciate ligament reconstruction (ACLR). DESIGN: Cohort study. SETTING: Academic medical center. PARTICIPANTS: 54 patients (25 females) undergoing unilateral ACLR. MAIN OUTCOME MEASURES: Cluster analysis distinguished FAM risk subgroups based on preoperative fear of movement/reinjury, self-efficacy, and pain catastrophizing. Preoperative expectation for surgical success was assessed with a numeric rating scale. Six and 12-month outcomes included Subjective Patient Outcomes for Return to Sport, Knee Injury and Osteoarthritis Outcome Score (KOOS) sports/recreation and quality of life, and International Knee Documentation Committee (IKDC) Subjective Knee Form. RESULTS: Thirteen (24%) patients were "moderate-to-high FAM risk." Moderate-to-high FAM risk patients had lower odds of return to sport at 12 months (OR = 0.3, p = .05) and lower KOOS sports/recreation at 6 months (st. beta = -0.27, p = .05), KOOS quality of life at 12 months (st. beta = -0.42, p = .007), and IKDC at 6 (st. beta = -0.29, p = .04) and 12 months (st. beta = -0.47, p = .001). Higher expectation was associated with lower 6-month IKDC (st. beta = -0.36, p = .008) and 12-month KOOS quality of life (st. beta = -0.29, p = .05). CONCLUSIONS: Preoperative FAM risk influences patient-reported outcomes and return to sport at 6 and 12 months.

Beach Chair Versus Lateral Decubitus Position: Differences in Suture Anchor Position and Number During Arthroscopic Anterior Shoulder Stabilization.

BACKGROUND: Arthroscopic shoulder capsulolabral repair using glenoid-based suture anchor fixation provides consistently favorable outcomes for patients with anterior glenohumeral instability. To optimize outcomes, inferior anchor position, especially at the 6-o'clock position, has been emphasized. Proponents of both the beach-chair (BC) and lateral decubitus (LD) positions advocate that this anchor location can be consistently achieved in both positions. HYPOTHESIS: Patient positioning would be associated with the surgeon-reported labral tear length, total number of anchors used, number of anchors in the inferior glenoid, and placement of an anchor at the 6-o'clock position. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: This study was a cross-sectional analysis of a prospective multicenter cohort of patients undergoing primary arthroscopic anterior capsulolabral repair. Patient positioning in the BC versus LD position was determined by the operating surgeon and was not randomized. At the time of operative intervention, surgeon-reported labral tear length, total anchor number, anchor number in the inferior glenoid, and anchor placement at the 6-o'clock position were evaluated between BC and LD cohorts. Descriptive statistics and between-group differences (continuous: t test [normal distributions], Wilcoxon rank sum test [nonnormal distributions], and chi-square test [categorical]) were assessed. RESULTS: In total, 714 patients underwent arthroscopic anterior capsulolabral repair (BC vs LD, 406 [56.9%] vs 308 [43.1%]). The surgeon-reported labral tear length was greater for patients having surgery in the LD position (BC vs LD [mean ± SD], 123.5°± 49° vs 132.3°± 44°; P = .012). The LD position was associated with more anchors placed in the inferior glenoid and more frequent placement of anchors at the 6-o'clock (BC vs LD, 22.4% vs 51.6%; P < .001). The LD position was more frequently associated with utilization of ≥4 total anchors (BC vs LD, 33.5% vs 46.1%; P < .001). CONCLUSION: Surgeons utilizing the LD position for arthroscopic capsulolabral repair in patients with anterior shoulder instability more frequently placed anchors in the inferior glenoid and at the 6-o'clock position. Additionally, surgeon-reported labral tear length was longer when utilizing the LD position. These results suggest that patient positioning may influence the total number of anchors used, the number of anchors used in the inferior glenoid, and the frequency of anchor placement at the 6 o'clock position during arthroscopic capsulolabral repair for anterior shoulder instability. How these findings affect clinical outcomes warrants further study. REGISTRATION: NCT02075775 (ClinicalTrials.gov identifier).

The Clinical Radiographic Incidence of Posttraumatic Osteoarthritis 10 Years After Anterior Cruciate Ligament Reconstruction: Data From the MOON Nested Cohort.

BACKGROUND: The incidence of posttraumatic osteoarthritis (PTOA) based on clinical radiographic grading criteria at 10 years after anterior cruciate ligament (ACL) reconstruction (ACLR) has not been well-defined in a prospective cohort of young athletic patients. HYPOTHESIS: Among young athletic patients, there is a high incidence of clinical radiographic PTOA at 10 years after ACLR. Additionally, there is a significant difference in clinical radiographic osteoarthritis (OA) changes (joint space narrowing and osteophyte formation) between ACL-reconstructed and contralateral knees at 10 years. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: The first 146 patients in an ongoing nested cohort study of the Multicenter Orthopaedic Outcomes Network (MOON) prospective cohort presented for a minimum 10-year follow-up. Included patients had a sports-related ACL injury, were aged <33 years at the time of ACLR, had no history of ipsilateral or contralateral knee surgery, and did not undergo revision ACLR before follow-up. Bilateral knee metatarsophalangeal view radiographs were obtained and graded according to International Knee Documentation Committee (IKDC), Osteoarthritis Research Society International (OARSI), and modified Kellgren-Lawrence (KL) criteria by 2 blinded reviewers. The incidence and severity of ipsilateral and contralateral radiographic OA were determined among patients without a contralateral ACL injury before 10-year follow-up (N = 133). RESULTS: Interrater reliability was substantial for the IKDC (Gwet Agreement Coefficient [AC] 1 = 0.71), moderate for the KL (0.48), and almost perfect for the OARSI (0.84) grading systems. Among patients with a contralateral radiographically normal knee, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The maximum side-to-side difference in the OARSI osteophyte grade in the medial or lateral compartment was 0 in 65% of patients, 1 in 20%, and ≥2 in 15%. The maximum side-to-side difference in the OARSI joint space narrowing grade was 0 in 77% of patients, 1 in 19%, and ≥2 in 4%. CONCLUSION: In young active patients, the 10-year incidence of clinical radiographic PTOA after ACLR was 37% as defined by osteophytes and 23% as defined by joint space narrowing. The mean difference in the degree of osteophyte formation (≤1 grade in 85%) and joint space narrowing (≤1 grade in 96%) between the ACL-reconstructed and contralateral knees was small. REGISTRATION: NCT02717559 (ClinicalTrials.gov identifier).

Male Sex, Western Ontario Shoulder Instability Index Score, and Sport as Predictors of Large Labral Tears of the Shoulder: A Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability Cohort Study.

PURPOSE: To identify factors predictive of a large labral tear at the time of shoulder instability surgery. METHODS: As part of the Multicenter Orthopaedic Outcomes Network (MOON) Shoulder Instability cohort, patients undergoing open or arthroscopic shoulder instability surgery for a labral tear were evaluated. Patients with >270° tears were defined as having large labral tears. To build a predictive logistic regression model for large tears, the Feasible Solutions Algorithm was used to add significant interaction effects. RESULTS: After applying exclusion criteria, 1235 patients were available for analysis. There were 222 females (18.0%) and 1013 males (82.0%) in the cohort, with an average age of 24.7 years (range 12 to 66). The prevalence of large tears was 4.6% (n = 57), with the average tear size being 141.9°. Males accounted for significantly more of the large tears seen in the cohort (94.7%, P = .01). Racquet sports (P = .01), swimming (P = .02), softball (P = .05), skiing (P = .04), and golf (P = .04) were all associated with large labral tears, as was a higher Western Ontario Shoulder Instability Index (WOSI; P = .01). Age, race, history of dislocation, and injury during sport were not associated with having a larger tear. Using our predictive logistic regression model for large tears, patients with a larger body mass index (BMI) who played contact sports were also more likely to have large tears (P = .007). CONCLUSIONS: Multiple factors were identified as being associated with large labral tears at the time of surgery, including male sex, preoperative WOSI score, and participation in certain sports including racquet sports, softball, skiing, swimming, and golf. LEVEL OF EVIDENCE: I, prognostic study.