Faculty Bibliography

There are multiple etiologies for revision anterior cruciate ligament reconstruction (ACLR), including but not limited to infection, arthrofibrosis, and graft failure, which should be distinguished before revision ACLR. Graft failure occurs when the reconstructed ligament does not restore knee stability, and it includes both graft rupture and functional failure in the setting of an intact graft. The causes of graft failure following ACLR can be divided into surgeon-controllable factors (ie, tunnel position, graft choice, alignment) and patient-centric factors (ie, patient age, tissue quality from systemic disease or smoking, compliance/traumatic reruptures). The purpose of this review is to propose an organized, easy-to-remember algorithm for the workup of surgeon-controlled ACLR graft failure etiologies, represented by the acronym "FATAL Graft."

INTRODUCTION/BACKGROUND:Operative management of multi-ligament knee injuries (MLKI) is technically challenging, with high complication rates. However, the impact of surgeon experience on surgical outcomes remains underreported. This purpose of this study was to examine how surgeon experience impacts operative time and complication rates. It was hypothesized that increased surgeon experience in MLKI correlates with reduced surgical duration and postoperative complications. METHODS:A retrospective review of MLKI patients who underwent reconstruction from 2011 to 2024 by fellowship-trained sports medicine surgeons at two high-volume level 1 trauma centers was conducted. Patient demographics, surgical procedure characteristics, complications, and surgeon experience (defined by years in practice postfellowship) were analyzed. Correlations were examined using linear regression for continuous variables and binary logistic regression for binary variables. RESULTS:There were 191 MLKI patients meeting inclusion criteria, with a 25.7% overall complication rate. Arthrofibrosis (16.2%) was most common, followed by recurrent instability (3.7%), infection (3.7%), revision surgery (2.7%), and hardware removal (1.0%). Controlling for age, sex, BMI, and number of ligaments reconstructed, we found a significant negative correlation between surgeon experience and both surgical duration (ß =  - 0.28, p < .001) and complication risk (OR 0.92, p = 0.024). CONCLUSION/CONCLUSIONS:This study demonstrates that increased surgeon experience in operative management of MLKI is associated with decreased complication rates and shorter procedure duration. Additional risk factors for complications included the number of ligaments injured and concomitant knee dislocation.

RATIONALE AND OBJECTIVES/OBJECTIVE:Multiple modalities exist for diagnosing ulnar neuropathy at the elbow (UNE), including electrodiagnostic testing (EDX), ultrasound (US), and magnetic resonance imaging (MRI), with no consensus on the optimal strategy. This study's objective was to determine the most cost-effective diagnostic strategy in patients with suspected UNE. MATERIALS AND METHODS/METHODS:We developed a decision analytic model from the U.S. healthcare perspective over a 1-year time horizon. Our hypothetical population comprised 56-year-old males with medial elbow pain and/or paresthesias radiating to the hand, without weakness. We compared incremental cost-effectiveness and total net monetary benefit (NMB) of single-modality strategies (EDX, US, MRI) and multimodality strategies (combinations of US/MRI, EDX/US, EDX/MRI). Input probabilities and utility values were obtained from the literature, and costs from Centers for Medicaid & Medicare Services and institutional data. The primary outcome was quality-adjusted life years (QALYs). Willingness-to-pay threshold was $100,000. RESULTS:The diagnostic strategy utilizing US first, followed by MRI, was favored with the highest total QALYs, .935, and total NMB, $92,667. EDX and US single-modality strategies were less favorable, with lower total QALYs, .894 and .906, respectively, and lower total NMB, $88,866 and $90,022. Other diagnostic strategies were excluded by absolute or extended dominance. One-way sensitivity analyses found model results sensitive to the utility of UNE recovery, but otherwise robust over a range of costs/probabilities. CONCLUSION/CONCLUSIONS:Our cost-effectiveness analysis suggests an initial US, then MRI is the most cost-effective strategy in the workup of patients with suspected UNE.

INTRODUCTION/BACKGROUND:Bone Marrow Lesions (BMLs) have a strong correlation to patient reported pain, functional limitations, joint deterioration, and rapid progression to total knee arthroplasty. The Subchondroplasty® (SCP) Procedure uses AccuFill®, a calcium phosphate bone substitute material (BSM), to treat bone defects such as microtrabecular fractures and BML. METHODS:This observational, prospective, multicenter, cohort study evaluated the effect of the SCP Procedure at two-year follow-up for 70 patients with knee BML. Under arthroscopic and fluoroscopic guidance, the BML was injected with AccuFill®. Patient reported outcomes, including Visual Analog Scale (VAS) pain, Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC), and modified Knee Society Score (mKSS) were collected through 24 months postoperatively. Radiographs and magnetic resonance images (MRI) were performed at baseline and up to 24 months post-operatively. Patient selection was not limited based on degree of osteoarthritis (OA) as determined radiologically by Kellgren-Lawrence (K-L) grade. For a subset of subjects, patient reported outcomes were collected up to five years including pain evaluation, patient knee global assessment, and satisfaction with the procedure. RESULTS:Pre-operative radiographs indicated moderate to severe osteoarthritis (K-L grades 2-4) in 65 subjects (92.8%). Significant improvements (p<0.0001) in mean VAS Pain, IKDC, mKSS and KOOS scores were observed compared with baseline. Kaplan-Meier survivorship free from conversion to knee arthroplasty was 76.2% at two years. The subset of subjects followed for five years demonstrated low pain scores and high procedure satisfaction. CONCLUSION/CONCLUSIONS:This study presents statistically significant and clinically meaningful evidence of improvement in clinical outcomes following SCP for BMLs of the knee after two years. The survivorship rate from arthroplasty at two years was 76.2%. SCP for BMLs can relieve pain with a minimally invasive procedure and may delay the need for knee arthroplasty.

PURPOSE/OBJECTIVE:The purpose of this study is to assess the association between sagittal tibial tuberosity-trochlear groove (sTT-TG) distance and patellofemoral chondral lesion size in patients undergoing cartilage restoration procedures. METHODS:A retrospective cohort analysis of patients who underwent an osteochondral allograft transplantation or matrix-induced autologous chondrocyte implantation in the patellofemoral compartment, from 2010 to 2020, were included if they had patellofemoral high-grade lesions, magnetic resonance imaging (MRI) and minimum 2-year follow-up. The preoperative sTT-TG distance was measured independently on axial T2-weighted MRI sequences by two authors, each at least two weeks apart. Intraoperative lesion size was reported according to operative report measurements by the attending surgeon. An interclass correlation coefficient (ICC) was calculated to assess intra- and inter-rater reliability, and categorical data analysis and linear regression models were used to assess the relationship between sTT-TG and lesion size. RESULTS:. Intra- (ICC: 0.99,0.98) and inter-rater reliability (ICC: 0.96) were excellent for both MRI defect size and sTT-TG measurements. The mean sTT-TG was -4.8 ± 4.9 mm and was significantly inversely related to MRI defect size (-0.45, p < 0.01), intraoperative patellar lesion size (-0.32, p = 0.01), total lesion area (-0.22, p = 0.04), but not trochlear lesion size (-0.09, p = 0.56). Multivariable regression demonstrated a more negative sTT-TG remained an independent variable correlated with larger MRI-measured patellofemoral defect sizes and intraoperative patellar lesions. CONCLUSION/CONCLUSIONS:A more negative sTT-TG was an independent variable correlated with larger patellofemoral lesions in patients undergoing patellofemoral cartilage restoration. LEVEL OF EVIDENCE/METHODS:Level III, Diagnostic.

PURPOSE/OBJECTIVE:To establish consensus statements on the diagnosis, nonoperative management, and labral repair for posterior shoulder instability. METHODS:A consensus process on the treatment of posterior shoulder instability was conducted, with 71 shoulder/sports surgeons from 12 countries participating on the basis of their level of expertise in the field. Experts were assigned to 1 of 6 working groups defined by specific subtopics within posterior shoulder instability. Consensus was defined as achieving 80% to 89% agreement, whereas strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS:Unanimous agreement was reached on the indications for nonoperative management and labral repair, which include whether patients had primary or recurrent instability, with symptoms/functional limitations, and whether there was other underlying pathology, or patient's preference to avoid or delay surgery. In addition, there was unanimous agreement that recurrence rates can be diminished by attention to detail, appropriate indication and assessment of risk factors, recognition of abnormalities in glenohumeral morphology, careful capsulolabral debridement and reattachment, small anchors with inferior placement and multiple fixation points that create a bumper with the labrum, treatment of concomitant pathologies, and a well-defined rehabilitation protocol with strict postoperative immobilization. CONCLUSIONS:The study group achieved strong or unanimous consensus on 63% of statements related to the diagnosis, nonoperative treatment, and labrum repair for posterior shoulder instability. The statements that achieved unanimous consensus were the relative indications for nonoperative management, and the relative indications for labral repair, as well as the steps to minimize complications for labral repair. There was no consensus on whether an arthrogram is needed when performing advanced imaging, the role of corticosteroids/orthobiologics in nonoperative management, whether a posteroinferior portal is required. LEVEL OF EVIDENCE/METHODS:Level V, expert opinion.

PURPOSE/OBJECTIVE:To assess clinical outcomes and return to sport (RTS) rates among patients that undergo osteochondral allograft (OCA) transplantation and autologous chondrocyte implantation (ACI) or matrix-induced autologous chondrocyte implantation (MACI), for patellofemoral articular cartilage defects. METHODS:A retrospective review of patients who underwent an OCA or ACI/MACI from 2010-2020 was conducted. Patient-reported outcomes (PROs) collected included: Visual Analog Scale for pain/satisfaction, Knee Injury and Osteoarthritis Outcome Score (KOOS), and RTS. The percentage of patients that met the Patient Acceptable Symptom State (PASS) for KOOS was recorded. Logistic regression was used to identify predictors of worse outcomes. RESULTS:A total of 95 patients were included (78% follow-up) with ACI or MACI performed in 55 cases (57.9%) and OCA in 40 (42.1%). A tibial tubercle osteotomy was the most common concomitant procedure for OCA (66%) and ACI/MACI (98%). Overall, KOOS pain was significantly poorer in OCA than ACI/MACI (74.7, 95% CI [68.1, 81.1] vs 83.6, 95% CI [81.3, 88.4], p= 0.012), while the remaining KOOS subscores were non-significantly different (all p>0.05). Overall, RTS rate was 54%, with no significant difference in return between OCA or ACI/MACI (52% vs 58%, p= 0.738). There were 26 (27%) reoperations and 5 (5%) graft failures in the entire group. Increasing age was associated with lower satisfaction in OCA and poorer outcomes in ACI/MACI, while larger lesion area was associated with lower satisfaction and poorer outcomes in ACI/MACI. CONCLUSION/CONCLUSIONS:Clinical and functional outcomes were similar in patients that underwent OCA or ACI/MACI for patellofemoral articular cartilage defects at a mean follow-up of 5 years. Patients who received OCA had a higher proportion of degenerative cartilage lesions and, among those with trochlear lesions, reported higher pain at final follow-up than their ACI/MACI counterparts. Overall, increasing age and a larger lesion size were associated with worse patient-reported outcomes.

An important domain of artificial intelligence is deep learning, which comprises computed vision tasks used for recognizing complex patterns in orthopaedic imaging, thus automating the identification of pathology. Purported benefits include an expedited clinical workflow; improved performance and consistency in diagnostic tasks; decreased time allocation burden; augmentation of diagnostic performance, decreased inter-reader discrepancies in measurements and diagnosis as a function of reducing subjectivity in the setting of differences in imaging quality, resolution, penetrance, or orientation; and the ability to function autonomously without rest (unlike human observers). Detection may include the presence or absence of an entity or identification of a specific landmark. Within the field of musculoskeletal health, such capabilities have been shown across a wide range of tasks such as detecting the presence or absence of a rotator cuff tear or automatically identifying the center of the hip joint. The clinical relevance and success of these research endeavors have led to a plethora of novel algorithms. However, few of these algorithms have been externally validated, and evidence remains inconclusive as to whether they provide a diagnostic benefit when compared with the current, human gold standard.

PURPOSE/OBJECTIVE:The purpose of the current study was to define the incidence of minor and major complications following TTO at a tertiary-care institution, with determination of predictive factors related to the occurrence of a major complication. STUDY DESIGN/METHODS:Retrospective case series. METHODS:Patients who underwent TTO from 2011 to 2023 were retrospectively identified. Patients who did not have at least 30 days of follow-up and revision cases were excluded. Complications classified as "major" included intraoperative fracture, postoperative fracture, loss of fixation, delayed union, non-union, pulmonary embolism (PE), patella tendon rupture, deep infection, painful hardware requiring removal, arthrofibrosis requiring reoperation, recurrent patellar instability, reoperation for other indications, readmission, and revision. Complications classified as minor included superficial infection, deep venous thrombosis, wound dehiscence, and postoperative neuropraxia. Chi-square tests were used for categorical variables, t-tests for continuous variables. RESULTS:Four hundred and seventy-six TTOs in 436 patients were included in the final cohort with a mean follow-up of 1.9 years (range 1 month-10 years). Patients were 68.5% female with average age 28.3 years (range 13-57 years). The overall complication rate was 27.5 percent. Major complications were recorded in 23.7% of TTOs, and minor complications in 8.4% of TTOs. Reoperation was required in 16.6% of TTOs at a mean of 14 months following the index procedure. The most common complications were painful hardware requiring removal (6.5%), superficial infection (5.7%), and arthrofibrosis requiring return to the operating room (OR) (5.0%). Prior ipsilateral surgery was identified as a significant independent predictor of major complication by regression analysis. Hardware removal was more common with headed screws. Arthrofibrosis requiring reoperation was more common in patients who underwent a concomitant cartilage restoration/repair procedure. CONCLUSION/CONCLUSIONS:The overall complication rate following tibial tubercle osteotomy was 27.5%, with painful hardware requiring removal (6.5%) as the most common complication, and an overall reoperation rate of 16.6%. TTOs with major complications were performed at earlier years, in patients who were older, had a previous ipsilateral arthroscopic knee surgery, had an indication of cartilage lesion/arthritis, and had a steeper osteotomy cut angle. Hardware removal was found to be more common in patients with headed as compared to headless screws. Complications also varied based on timing after surgery.

BACKGROUND/UNASSIGNED:As machine learning becomes increasingly utilized in orthopaedic clinical research, the application of machine learning methodology to cohort data from the Multicenter ACL Revision Study (MARS) presents a valuable opportunity to translate data into patient-specific insights. PURPOSE/UNASSIGNED:To apply novel machine learning methodology to MARS cohort data to determine a predictive model of revision anterior cruciate ligament reconstruction (rACLR) graft failure and features most predictive of failure. STUDY DESIGN/UNASSIGNED:Cohort study; Level of evidence, 3. METHODS/UNASSIGNED:The authors prospectively recruited patients undergoing rACLR from the MARS cohort and obtained preoperative radiographs, surgeon-reported intraoperative findings, and 2- and 6-year follow-up data on patient-reported outcomes, additional surgeries, and graft failure. Machine learning models including logistic regression (LR), XGBoost, gradient boosting (GB), random forest (RF), and a validated ensemble algorithm (AutoPrognosis) were built to predict graft failure by 6 years postoperatively. Validated performance metrics and feature importance measures were used to evaluate model performance. RESULTS/UNASSIGNED:The cohort included 960 patients who completed 6-year follow-up, with 5.7% (n = 55) experiencing graft failure. AutoPrognosis demonstrated the highest discriminative power (model area under the receiver operating characteristic curve: AutoPrognosis, 0.703; RF, 0.618; GB, 0.660; XGBoost, 0.680; LR, 0.592), with well-calibrated scores (model Brier score: AutoPrognosis, 0.053; RF, 0.054; GB, 0.057; XGBoost, 0.058; LR, 0.111). The most important features for AutoPrognosis model performance were prior compromised femoral and tibial tunnels (placement and size) and allograft graft type used in current rACLR. CONCLUSION/UNASSIGNED:The present study demonstrated the ability of the novel AutoPrognosis machine learning model to best predict the risk of graft failure in patients undergoing rACLR at 6 years postoperatively with moderate predictive ability. Femoral and tibial tunnel size and position in prior ACLR and allograft use in current rACLR were all risk factors for rACLR failure in the context of the AutoPrognosis model. This study describes a unique model that can be externally validated with larger data sets and contribute toward the creation of a robust rACLR bedside risk calculator in future studies. REGISTRATION/UNASSIGNED:NCT00625885 (ClinicalTrials.gov identifier).