Krych, Aaron J.

Background: Osteochondritis dissecans (OCD) of the knee is a focal idiopathic alteration of subchondral bone and/or its precursor with risk for instability and disruption of adjacent cartilage. Treatment options focused on preventing premature osteoarthritis vary depending on multiple patient and lesion characteristics, including lesion mobility. Purpose: To differentiate lesion mobility before arthroscopy using a multivariable model that includes patient demographic characteristics and physical examination findings. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: Demographic, preoperative physical examination, and radiographic data were collected from a multicenter national prospective cohort of patients with OCD of the knee. Inclusion criteria included patients <19 years of age and patients with arthroscopically confirmed mobility status based on the Research on Osteochondritis Dissecans of the Knee arthroscopy classification. Multivariable logistic regression analysis using stepwise model selection was used to determine factors associated with the likelihood of a mobile versus an immobile lesion. A 75% partition of the data was used for model training, and 25% was used as a validation cohort. Quantitative model fit statistics were computed using the holdout data, including sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC), along with the corresponding 95% CI. Results: A total of 407 patients in the prospective cohort met inclusion criteria, and 62% were male. The mean ± SD age was 13.7 ± 2.2 years, height 161.8 ± 5.3 cm, and weight 59.2 ± 42.2 kg. Arthroscopic evaluation yielded 235 immobile and 172 mobile lesions. Multivariable analysis determined that the best model to predict lesion mobility included chronologic age ≥14 years ( P < .001), effusion on physical examination ( P < .001), and any loss of range of motion on physical examination ( P = .07), while controlling for male sex ( P = .38) and weight >54.4 kg ( P = .12). In the 25% holdout validation sample (n = 102), a sensitivity of 83%, a specificity of 82%, and an AUC of 0.89 (95% CI, 0.82-0.95) were achieved with these predictive factors. Conclusion: Age, effusion, and loss of motion can predict knee OCD lesion mobility at the time of arthroscopy. Education about lesion mobility can help with surgical planning and patient and family counseling.

AimsDistal femoral osteotomies (DFOs) are commonly used for the correction of valgus deformities and lateral compartment osteoarthritis. However, the impact of a DFO on subsequent total knee arthroplasty (TKA) function remains a subject of debate. Therefore, the purpose of this study was to determine the effect of a unilateral DFO on subsequent TKA function in patients with bilateral TKAs, using the contralateral knee as a self-matched control group.MethodsThe inclusion criteria consisted of patients who underwent simultaneous or staged bilateral TKA after prior unilateral DFO between 1972 and 2023. The type of osteotomy performed, osteotomy hardware fixation, implanted TKA components, and revision rates were recorded. Postoperative outcomes including the Forgotten Joint Score-12 (FJS-12), Tegner Activity Scale score, and subjective knee preference were also obtained at final follow-up.ResultsA total of 21 patients underwent bilateral TKA following unilateral DFO and were followed for a mean of 31.5 years (SD 11.1; 20.2 to 74.2) after DFO. The mean time from DFO to TKA conversion was 13.1 years (SD 9.7) with 13 (61.9%) of DFO knees converting to TKA more than ten years after DFO. There was no difference in arthroplasty implant systems employed in both the DFO-TKA and TKA-only knees (p > 0.999). At final follow-up, the mean FJS-12 of the DFO-TKA knee was 62.7 (SD 36.6), while for the TKA-only knee it was 65.6 (SD 34.7) (p = 0.328). In all, 80% of patients had no subjective knee preference or preferred their DFO-TKA knee. Three DFO-TKA knees and two TKA-only knees underwent subsequent revision following index arthroplasty at a mean of 12.8 years (SD 6.9) and 8.5 years (SD 3.8), respectively (p > 0.999).ConclusionIn this self-matched study, DFOs did not affect subsequent TKA function as clinical outcomes, subjective knee preference, and revision rates were similar in both the DFO-TKA and TKA-only knees at mean 32-year follow-up.Cite this article: Bone Jt Open 2024;5(11):1013–1019.

Purpose To evaluate the available literature on the relationship between knee bony morphology and medial meniscus posterior root tears (MMPRTs) to determine which tibiofemoral morphologic risk factors may predispose the development of MMPRTs. Methods Embase, MEDLINE, and PubMed databases were searched to identify all relevant human clinical studies investigating knee morphologic features and MMPRTs. Shape features were compared between control groups and patients with MMPRTs. The methodological index for nonrandomized studies (MINORS) instrument was utilized to assess the methodological quality of included studies. Results Thirteen level III evidence studies and 1 level IV evidence study were included in this review (n = 2,181), with 895 patients in the MMPRT group and 1,286 in the control group. Tibial morphology features associated with an increased risk for MMPRTs included an increased medial tibial slope (6 studies), increased tibial torsion (1 study), increased medial meniscal slope (1 study), and shallower medial tibial plateau concavity (1 study). Varus mechanical alignment was found to increase the risk for MMPRTs (4 studies). Femoral morphology features associated with an increased risk for MMPRTs included an A‐type intercondylar notch (1 study), increased medial femoral condyle (MFC) angle (1 study), narrower intercondylar distance (1 study), narrower intercondylar notch width (1 study), shorter MFC distal offset distance (1 study), increased MFC width (1 study), increased MFC to medial tibial condyle width ratio (1 study), greater distance between the medial tibial eminence and MFC (1 study), and smaller femoral offset ratios of both the medial and lateral condyles (1 study). Conclusions Multiple tibiofemoral shape features, including a steeper slope of the medial tibial plateau, greater varus alignment, and a narrower intercondylar distance and notch width, were found to be predictive factors for MMPRTs. Level of Evidence Level IV, systematic review of Level III and IV studies.

Abstract Periprosthetic fractures of the lesser trochanter may migrate proximally and result in anterior mechanical irritation and impingement with hip flexion refractory to comprehensive conservative management. In such cases, patients may benefit from arthroscopic resection of the displaced lesser trochanteric fragment. We present a minimally invasive, arthroscopic approach with initial access through an air bursogram. This technique can be performed percutaneously, with standard access cannulas, without the need for additional disposable instrumentation or large cannulas. In such a way, reproducible arthroscopic instrumentation can be provided for safe and efficient fragment removal while remaining cognizant of the nearby medial neurovascular bundle. Technique Video video See video under supplementary data.

Background: Patients with persistent symptomatic iliopsoas tendonitis following total hip arthroplasty may benefit from iliopsoas fractional lengthening. We present an arthroscopic approach utilizing an air bursogram that provides safe and predictable access to the iliopsoas tendon for efficient tendon lengthening without violating the capsule or unintentional instrumentation of the nearby medial neurovascular bundle. Indications: Arthroscopic iliopsoas fractional lengthening is indicated for patients with clinical evidence of symptomatic iliopsoas tendonitis following total hip arthroplasty and have no radiographic evidence of frank acetabular malpositioning. A diagnosis of iliopsoas tendinitis amenable to surgical management can be established with substantial but nondurable relief following image-guided anesthetic injection to the iliopsoas bursa. Technique Description: Under fluoroscopic guidance, an air bursogram is employed in the anatomic plane of the iliopsoas tendon to accurately identify its course. This allows for hip portal placement with precise subsequent instrumentation. This technique is preferred in the setting of postarthroplasty anatomy because it avoids capsular violation and the challenge of working in an altered anatomic space with a nearby, medially based neurovascular bundle. Results: Arthroscopic and endoscopic approaches to iliopsoas release have been shown to provide excellent functional and patient-reported outcomes in >85% of patients, and several studies have shown that an arthroscopic approach not only provides a less invasive technique but also results in comparable or improved clinical outcomes with lower revision rates compared to open release or acetabular cup revision. Our technique for arthroscopic iliopsoas fractional lengthening using the air bursogram is both safe and reproducible and offers distinct advantages, including maintenance of an intact capsule, visual confirmation of the correct anatomic structure to be released, and percutaneous access with standard arthroscopic access cannulas without the need for hip distraction. Conclusions: Arthroscopic fractional iliopsoas lengthening is a minimally invasive and successful treatment option for patients with persistent groin pain after total hip arthroplasty, especially without substantial acetabular component malpositioning. This technique includes using an air bursogram to safely identify and navigate to the iliopsoas tendon without violating the hip capsule, thereby reducing the risk of inadvertent instrumentation of adjacent critical neurovascular structures. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Background: Anterior cruciate ligament (ACL) reconstruction (ACLR) can be successful in restoring knee stability. However, secondary ACL injury, either through graft failure or contralateral injury, is a known complication and can significantly impact the ability of a patient to return successfully to previous activities. Purpose: To develop and internally validate an interpretable machine learning model to quantify the risk of graft failure and contralateral ACL injury in a longitudinal cohort treated with ACLR. Study Design: Case-control study; Level of evidence, 3. Methods: An established geographic database of >600,000 patients was used to identify patients with a diagnosis of ACL rupture between 1990 and 2016 with a minimum 2-year follow-up. Medical records were reviewed for relevant patient information and 4 candidate machine learning algorithms were evaluated for prediction of graft failure and contralateral ACL injury in patients after ACLR as identified either on magnetic resonance imaging or via arthroscopy. Performance of the algorithms was assessed through discrimination, calibration, and decision curve analysis. Model interpretability was enhanced utilizing global variable importance plots and partial dependence curves. Results: A total of 1497 patients met inclusion criteria. Among them, 140 (9.4%) had graft failure and 128 (8.6%) had a contralateral ACL injury after index surgery at a median follow-up of 140.7 months (interquartile range, 77.2-219.2 months). The best performing models achieved an area under the receiver operating characteristics curve of 0.70 for prediction of graft failure and 0.67 for prediction of contralateral ACL injury, outperforming a logistic regression fitted on the identical feature set. Notable predictors for increased risk of graft failure included younger age at injury, body mass index (BMI) <30, return to sports <13 months, initial time to surgery >75 days, utilization of allograft, femoral/tibial fixation with suspension/expansion devices, concomitant collateral ligament injury, and active or former smoking history. Predictors of contralateral ACL injury included greater preoperative pain, younger age at initial injury, BMI <30, active smoking history, initial time to surgery >75 days, history of contralateral knee arthroscopies, and involvement in contact sports. Conclusion: Less than 18% of all patients who undergo ACLR should be expected to sustain either a graft failure or contralateral ACL injury. Machine learning models outperformed logistic regression and identified greater preoperative pain, younger age, BMI <30, earlier return to higher activity, and time to surgical intervention >75 days as common risk factors for both graft failure as well as contralateral ACL injury after ACLR. Surgeon-modifiable risk factors for graft failure included allograft and femoral/tibial fixation with a suspension/expansion combination.

Abstract Meniscal root tears have been shown to significantly impact tibiofemoral mechanics and contribute to accelerated development of osteoarthritis. A common finding in conjunction with a meniscal root tear is extrusion of the meniscus. Meniscal extrusion is an independent risk factor for tibiofemoral cartilage loss and the progression of osteoarthritis. Meniscus centralization was first introduced to directly address extrusion alongside root repair techniques. To date, reported techniques for meniscus centralization generally involve anchoring the meniscus directly to the tibia in some fashion, which can limit the normal anatomic motion of the meniscus. We present a technique for meniscus centralization that aims to maintain natural meniscal motion by utilizing the meniscotibial ligaments. Technique Video video See video under supplementary data.

Background: Value-based decision-making regarding nonoperative management versus early surgical stabilization for first-time anterior shoulder instability (ASI) events remains understudied. Purpose: To perform (1) a systematic review of the current literature and (2) a Markov model–based cost-effectiveness analysis comparing an initial trial of nonoperative management to arthroscopic Bankart repair (ABR) for first-time ASI. Study Design: Economic and decision analysis; Level of evidence, 3. Methods: A Markov chain Monte Carlo probabilistic model was developed to evaluate the outcomes and costs of 1000 simulated patients (mean age, 20 years; range, 12-26 years) with first-time ASI undergoing nonoperative management versus ABR. Utility values, recurrence rates, and transition probabilities were derived from the published literature. Costs were determined based on the typical patient undergoing each treatment strategy at the authors’ institution. Outcome measures included costs, quality-adjusted life-years (QALYs), and the incremental cost-effectiveness ratio (ICER). Results: The Markov model with Monte Carlo microsimulation demonstrated mean (± standard deviation) 10-year costs for nonoperative management and ABR of $38,649 ± $10,521 and $43,052 ± $9352, respectively. Total QALYs acquired over the 10-year time horizon were 7.67 ± 0.43 and 8.44 ± 0.46 for nonoperative management and ABR, respectively. The ICER comparing ABR with nonoperative management was found to be just $5725/QALY, which falls substantially below the $50,000 willingness-to-pay (WTP) threshold. The mean numbers of recurrences were 2.55 ± 0.31 and 1.17 ± 0.18 for patients initially assigned to the nonoperative and ABR treatment groups, respectively. Of 1000 samples run over 1000 trials, ABR was the optimal strategy in 98.7% of cases, with nonoperative management the optimal strategy in 1.3% of cases. Conclusion: ABR reduces the risk for recurrent dislocations and is more cost-effective despite higher upfront costs when compared with nonoperative management for first-time ASI in the young patient. While all these factors are important to consider in surgical decision-making, ultimate treatment decisions should be made on an individual basis and occur through a shared decision-making process.

Background: The number of hip arthroscopies performed in the United States has grown significantly over the past several decades, with evolving indications and emerging techniques. Purposes: To (1) examine the evolution of hip arthroscopy at 3 tertiary referral centers between 1988 and 2022 and (2) quantify trends in patient demographics and procedures performed. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was performed of all patients undergoing hip arthroscopy at 3 academic centers between 1988 and 2022. Demographic data were collected using standardized forms and operative notes, and intraoperative images were manually reviewed for each patient to determine the specific procedures performed at the time of the hip arthroscopy. Surgical procedures were plotted over time to evaluate trends. Patients were divided into 3 time periods for comparison: early hip arthroscopy from 1988 to 2008, 2009 (the time of the first labral repair in our cohort) to 2015, and 2016 to 2022. Results: A total of 3000 patients (age, 35.7 ± 13.8 years; age range, 10-89 years; female sex, 2109 (70.3%); body mass index, 27.4 ± 6.3 kg/m 2 ) underwent arthroscopic hip procedures between 1988 and 2022. The mean number of cases increased from a mean of 3.2 per year in 1988-2008 to 285.9 per year in 2016-2022 ( P < .001). Labral treatment at the time of primary hip arthroscopy evolved from 100% debridement and 0% repair in 1988-2008 to 5.0% debridement, 94.0% repair, and 1.0% labral reconstruction in 2016-2022 ( P < .001). Cam resection increased from 4.1% in 1988-2008 to 86.9% in 2016-2022 ( P < .001). By 2022, 45 out of 325 cases (13.8%) were revisions. The rate of capsular repair at the time of primary hip arthroscopy increased from 0.0% in 1988-2008 up to 81.0% in 2016-2022. Conclusion: There has been a significant growth of hip arthroscopy volumes as well as a significant transition from use as a tool for diagnosis and labral debridement to procedures restoring native anatomy including labral repair, cam resection, capsular repair, periacetabular osteotomy, and gluteal repair.

Objectives: Based in part on the results of randomized controlled trials (RCTs) that suggest a beneficial effect over alternative treatment options, the use of platelet-rich plasma (PRP) for the management of knee osteoarthritis (OA) is widespread and increasing. However, the extent to which these studies are vulnerable to slight variations in the outcomes of patients remains unknown. The purpose of this study is to evaluate the statistical fragility of conclusions from RCTs that reported outcomes of patients with knee OA who were treated with PRP versus alternative nonoperative management strategies. Methods: All RCTs comparing PRP to alternative nonoperative treatment options for knee OA were identified. The fragility index (FI) and reverse fragility index (RFI) were applied to assess the robustness of conclusions regarding the efficacy of PRP for knee OA. Meta-analyses were performed to determine the minimum number of patients from one or more trials included in the meta-analysis for which a modification on the event status would change the statistical significance of the pooled treatment effect. Results: In total, this analysis included outcomes from 1993 patients with a mean (± standard deviation) age of 58.0 ± 3.8 years. The mean number of events required to reverse significance (FI) was 4.57 ± 5.85. This corresponded to a fragility quotient of 0.060 ± 0.075, meaning the significance of the results was contingent on 6 events per 100 participants. For non-significant outcome events, the mean number of events required to reverse statistical nonsignificance (RFI) was 4.41 ± 2.22. This corresponded to a reverse fragility quotient of 0.065 ± 0.056, meaning the non-significance of the results was contingent on 6.5 events per 100 participants (Figure 1). Based on random-effects meta-analyses, PRP demonstrated a significantly higher rate of successful outcomes when compared to hyaluronic acid (p = 0.002, odds ratio 95% CI = 2.19 [1.33-3.62]) (Figure 2) as well as higher rates of patient-reported symptom relief (p = 0.019, odds ratio [95% CI] = 1.55 [1.07-2.24]) (Figure 3), not requiring a reintervention after the initial injection treatment (p = 0.002, odds ratio [95% CI] = 2.17 [1.33-3.53]) (Figure 4), and achieving the minimal clinically important difference (MCID) for pain improvement (p = 0.007, odds ratio [95% CI] = 6.19[1.63-23.42]) when compared to all alternative nonoperative treatments. Overall, the mean number of events per meta-analysis required to change the statistical significance of the pooled treatment effect was 8.67 ± 4.50. Conclusions: Individual RCTs evaluating PRP for knee OA possess slight robustness. Upon meta-analysis, PRP demonstrated a significant advantage over HA as well as improved symptom relief, lower rates of reintervention, and more frequent achievement of the MCID for pain improvement when compared to alternative, nonoperative treatment options. Statistically significant pooled treatment effects evaluating PRP for knee OA are more robust than approximately half of all comparable meta-analyses in medicine and healthcare. Future RCTs and meta-analyses should consider reporting fragility indices and quotients to facilitate interpretation of results in their proper context. In addition, the robustness of these findings suggests that reconsideration of the American Academy of Orthopaedic Surgeons clinical practice guidelines around the use of PRP for knee OA may be warranted.