Faculty Bibliography

BACKGROUND/UNASSIGNED:Uniplanar coronal tibiofemoral subluxation (UCTFS) in the setting of multiple ligament knee injury (MLKI) or knee dislocation (KD) has rarely been discussed, and the potential for missed diagnosis may significantly impact long-term outcomes. PURPOSE/UNASSIGNED:To describe the presentation, injury patterns, possible mechanical barriers for reduction, and management for isolated UCTFS after MLKI/KD. STUDY DESIGN/UNASSIGNED:Case series; Level of evidence, 4. METHODS/UNASSIGNED:A retrospective chart review was conducted at 4 institutions to identify patients with KD or MLKI who were evaluated with or developed subsequent UCTFS from January 2001 to January 2024. UCTFS was defined as medial or lateral translation of the tibial plateau in reference to the femoral condyle as seen on coronal imaging (radiograph, computed tomography scan, or magnetic resonance imaging scan), with normal alignment seen on the sagittal imaging. Medical records were reviewed for demographic data, clinical presentation, physical examination, diagnostic imagining, examination under anesthesia, surgical finding, and procedures performed. RESULTS/UNASSIGNED:A total of 15 cases were included. Of these, 12 patients were subluxed laterally and 3 medially. UCTFS was diagnosed at different time points with 10 patients within 1 week, 2 patients between 1 and 6 weeks, and 3 patients after 6 weeks from injury. The most common mechanism of injury was a fall (33%), and the most common pattern of injury was a KD-3L (26.6%). A mechanical blockage to reduction was found in 9 (60%) cases. These included medial soft tissue sleeve incarceration (n = 4), bucket-handle meniscal tears (n = 3), concomitant patellar dislocation (n = 2), and a displaced tibial spine fracture (n = 1). Some patients experienced subluxation due to several sources of mechanical block. Uniplanar external fixation was utilized in 7 patients for management of their initial ligamentous injuries, coronal instability, or a traumatic vascular injury. Hinged external fixation was utilized in 2 patients who presented in a chronic fashion to counter the propensity to subluxation while allowing early motion. CONCLUSION/UNASSIGNED:UCTFS is a rare event that has several potential factors contributing to its cause, and ≥1 of these factors may need to be surgically addressed. Tibiofemoral subluxation can be found at various time points from injury, and awareness and monitoring for its development should be factored into the clinical decision-making. UCTFS is a challenging clinical dilemma that may require multiplanar or hinged external fixation to maintain reduction.

This review offers a comprehensive discussion of magnetic resonance imaging (MRI) for the assessment of rotator cuff tendon repair and joint-preserving surgical options for patients with irreparable rotator cuff tears. Deciding to proceed with arthroscopic repair of a rotator cuff tendon tear is impacted both by clinical factors and morphological imaging features. Preoperative clinical and imaging features also predict the likelihood of success of a rotator cuff tendon repair and are important to recognize. In patients with irreparable rotator cuff tears and relatively preserved glenohumeral cartilage, various joint-preserving surgical options are available and seen increasingly in clinical practice.The acceptable range of postoperative imaging findings correlating with a functionally intact rotator cuff repaired tendon, and MRI findings that are either suggestive of or definitive for rotator cuff tendon repair failure are discussed in detail, with attention to the Sugaya classification. Ancillary features, such as progressive retraction of the myotendinous junction and the degree of muscle fatty atrophy, can be used as problem-solving tools in cases equivocal for rotator cuff retear. Finally, this review discusses in detail the most common joint-preserving treatment options for patients with irreparable rotator cuff tears, including an in-depth focus on superior capsular reconstruction.

BACKGROUND/UNASSIGNED:Traditional freehand techniques in high tibial osteotomy (HTO) have been shown to lack precision and accuracy. Patient-specific instrumentation (PSI) and fixation created from cross-sectional imaging have recently been introduced to address this problem. PURPOSE/HYPOTHESIS/UNASSIGNED:The purpose of the study was to compare traditional freehand techniques versus PSI in a human cadaveric model of HTO. It was hypothesized that the osteotomies performed using PSI would require less radiation exposure for operating room staff and would reduce deviation from the planned correction in the coronal, sagittal, and axial planes. STUDY DESIGN/UNASSIGNED:Controlled laboratory study. METHODS/UNASSIGNED:Sixteen matched cadaveric knees underwent medial opening-wedge HTO via the freehand method (n = 8) or PSI technique (n = 8) with a predetermined planned opening-wedge size. Computed tomography was used to measure the achieved wedge size as well as alignment parameters in the coronal, sagittal, and axial planes. Radiation dose, number of fluoroscopic images taken, and total operative time were recorded. RESULTS/UNASSIGNED:= .62). CONCLUSION/UNASSIGNED:In cadaveric specimens, the PSI technique demonstrated superior accuracy and decreased radiation exposure for medical staff compared with the traditional freehand technique without compromising operative efficiency. CLINICAL RELEVANCE/UNASSIGNED:The use of PSI when HTO is performed can lead to more accurate operations and potentially improve outcomes.

BACKGROUND/UNASSIGNED:Mountain biking (MTB) is a quickly growing sport, with many athletes sustaining high-impact injuries. Current literature has not analyzed the most recent MTB-related national emergency department (ED) injury data. HYPOTHESIS/UNASSIGNED:It was hypothesized that (1) the total number of injuries presenting to US EDs would significantly increase over the study period, (2) male patients would experience higher rates of shoulder injuries and airborne injury mechanisms than female patients, and (3) youths would present more frequently with injuries of the head and face than adults. STUDY DESIGN/UNASSIGNED:Descriptive epidemiology study. METHODS/UNASSIGNED:All data were extracted from the National Electronic Injury Surveillance System (NEISS), a public database representing approximately 100 US EDs. The NEISS was queried for MTB-related injuries between January 1, 2013, and December 31, 2022. RESULTS/UNASSIGNED:< .001) than male patients. Children presented with higher rates of head/face injuries (34.1%), concussions (6.0%), and airborne mechanisms of injury (19.4%) than any other age group. CONCLUSION/UNASSIGNED:MTB injuries increased significantly between 2013 and 2022 likely because of the popularity of outdoor sports during COVID-19. The upper extremity was the most frequently injured body region, and falling off the bike was the most common mechanism. Leading injuries and mechanisms varied significantly by sex and age. This study recommends additional MTB safety measures such as shoulder support for male riders, better coaching on front brake control for youth riders, and an increased emphasis on concussion protocols for female riders.

PURPOSE/OBJECTIVE:To describe the medial-sided pathoanatomy and ligament injuries in acute MLKIs with medial-sided involvement andlook forassociated injury patterns based upon location of ligamentous injury. METHODS:Patients who underwent treatment for MLKI at two level-1 trauma centers were identified between January 2001 and May 2023. Only cases involvingcomplete disruption of the superficial medial collateral ligament (sMCL) were included. Zone of injury to the sMCL, the posterior oblique ligament (POL), the medial patellofemoral ligament (MPFL), the vastus medialis oblique (VMO) was recorded, as well as demographics,injury details, neurovascular status, and mechanism of injury.Data was summarized usingdescriptive statistics. RESULTS:A total of 92 patientswere included, with a mean age of 37.8 ± 12.7 years. Forty-four (47.8%) patients had a high velocity injury. Within sMCL tears, 39% were proximal avulsions, 29% were midsubstance tears, and 32% were distal avulsions. The medial-sided injury patterns were: 31 (33.7%) isolated sMCL tears, 24 (27.3%) combined sMCL, POL, and MPFL tears, 23 (25%) combined sMCL and MPFL tears, and 11 (12%) combined sMCL and POL tears. Most common location of sMCL injury varied based upon the number of associated medial knee ligaments injured: isolated sMCL (even distribution), sMCL & POL (distal), sMCL-MPFL (proximal), sMCL-POL-MPFL (proximal). CONCLUSION/CONCLUSIONS:Medial-sided ligament injuries seen MLKIs were found to occur in four injury patterns ranging from isolated sMCL or combined injury patterns of the adjacent medial structures. Additionally, location of sMCL injury varied based upon the number of medial-sided ligaments injured.

PURPOSE/OBJECTIVE:There is limited clinical outcome data comparing fixation methods for tenodesis of the long head of the biceps tendon (LHBT), particularly button fixation. The purpose of this study was to compare clinical outcomes, patient-reported outcomes, and return to sport (RTS) between patients undergoing LHBT with bicortical versus unicortical button technique. The authors hypothesized these fixation methods would be similar for all outcomes. METHODS:Patients who underwent LHBT using unicortical or bicortical button fixation with minimum 2-year follow-up were identified. Postoperative outcomes were evaluated using the American Shoulder and Elbow Surgeons (ASES) questionnaire and visual analogue scale (VAS) pain score. A sports activity survey was collected to assess baseline sport participation and ability to return to pre-injury activities. Continuous variables were analyzed using the Mann-Whitney-U test. Categorical variables were analyzed using Chi-squared tests. Multivariable logistic and linear regression were performed to determine predictors of RTS and time to RTS. RESULTS:Sixty-four subjects (19 unicortical and 45 bicortical button fixation) were included (average follow-up 3.5 (range: 2.0-7.8) years). There were no significant differences found between button groups for VAS pain score (1.5 vs. 1.2; p = 0.876), VAS pain during sport score (1.6 vs. 1.1, p = 0.398), and ASES score (66 vs. 71; p = 0.294). There were no significant differences in rate of RTS (75.0 vs. 77.4%; p = 0.885) or average time to return to sport (11.7 ± 7.3 vs. 7.0 ± 4.0 months; p = 0.081) between groups. CONCLUSION/CONCLUSIONS:There were no significant differences in clinical outcomes, pain, or return to sport between patients who underwent LHBT with unicortical or bicortical button fixation.

PURPOSE/OBJECTIVE:To evaluate long-term outcomes of patients treated with posterior medial meniscal root tear (PMMRT) repair through assessment of functional outcome scores and to identify patient surgical and magnetic resonance imaging (MRI) characteristics associated with improved outcomes. METHODS:This was a single-centre, retrospective study evaluating patients who had undergone a PMMR repair using a transtibial suture pullout technique with two locking cinch sutures. This was performed as a follow-up to previously published 2-year and 5-year outcome studies, using the same cohort. All patients from the prior short-term and midterm studies were invited to participate. Patient-reported outcome (PROs) scores, including the International Knee Documentation Committee (IKDC) and Lysholm scores, were collected. Previously collected demographic data were updated based on review of the electronic medical record. Patient outcomes were assessed preoperatively, as well as at 2-year, 5-year and 8-year postoperatively. MRI outcome measurements were assessed at 2-year and 5-year follow-ups. All statistical analysis was performed using SPSS version 26. RESULTS:Seventeen patients of the original 18 patients (94.4%) were included in the final analysis. Additionally, three patients who had additional ipsilateral surgery were excluded from the analysis of PROs. The IKDC score significantly increased from 44.7 ± 11.6 at preoperative baseline to 71.2 ± 21.3 at 8-year post-operation (p = 0.001). There were no significant differences in IKDC score between 2-year and 8-year follow-ups (p = n.s.) or 5-year and 8-year follow-ups (p = n.s.). The Lysholm score significantly increased from 49.6 ± 7.3 at preoperative baseline to 76.4 ± 17.2 at 8-year follow-up (p < 0.001). There was no significant difference in Lysholm scores between 2-year and 8-year follow-ups (p = n.s.) or 5-year and 8-year follow-ups (p = n.s.). A linear regression analysis found that 5-year IKDC scores were significantly correlated with 8-year IKDC scores (β = 0.681, p = 0.038). At 8-year follow-up, four (23.5%) patients required additional procedures on their operative knee (one total knee arthroplasty conversion). CONCLUSION/CONCLUSIONS:Patients treated with repair of PMMRT had maintenance of clinical outcome improvements at long-term follow-up despite worsening MRI outcomes at short-term and medium-term follow-ups. While a high proportion of patients required additional procedures on their operative knee at 8-year follow-up, few of these patient's additional procedures were related to failure of their primary surgery. Providers and patients may expect durable clinical outcomes following the repair of PMMRT, irrespective of radiographic appearance. LEVEL OF EVIDENCE/METHODS:Level IV.

In recent years, there has been a shift in healthcare away from the fee-for-service model to a value-based care model. Concomitantly, there have been changes in inflation-adjusted surgeon reimbursements for arthroscopic meniscectomies. Nationally, albeit at different rates, there has been a decrease in partial meniscectomy utilization. We feel that this is in part due to the change in healthcare economics and reimbursements as well as the growing evidence that partial meniscectomy may not be as efficacious in the treatment of degenerative meniscus tears as we once thought.

PURPOSE/UNASSIGNED:To systematically review the literature regarding machine learning in leg length discrepancy (LLD) and to provide insight into the most relevant manuscripts on this topic in order to highlight the importance and future clinical implications of machine learning in the diagnosis and treatment of LLD. METHODS/UNASSIGNED:A systematic electronic search was conducted using PubMed, OVID/Medline and Cochrane libraries in accordance with Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Two observers independently screened the abstracts and titles of potential articles. RESULTS/UNASSIGNED:A total of six studies were identified in the search. All measurements were calculated using standardized anterior-posterior long-leg radiographs. Five (83.3%) of the studies used measurements of the femoral length, tibial length and leg length to assess LLD, whereas one (16.6%) study used the iliac crest height difference to quantify LLD. The deep learning models showed excellent reliability in predicting all length measurements with intraclass correlation coefficients ranging from 0.98 to 1.0 and mean absolute error (MAE) values ranging from 0.11 to 0.45 cm. Three studies reported measurements of LLD, and the convolutional neural network model showed the lowest MAE of 0.13 cm in predicting LLD. CONCLUSIONS/UNASSIGNED:Machine learning models are effective and efficient in determining LLD. Implementation of these models may reduce cost, improve efficiency and lead to better overall patient outcomes. CLINICAL RELEVANCE/UNASSIGNED:This review highlights the potential of deep learning (DL) algorithms for accurate and reliable measurement of lower limb length and leg length discrepancy (LLD) on long-leg radiographs. The reported mean absolute error and intraclass correlation coefficient values indicate that the performance of the DL models was comparable to that of radiologists, suggesting that DL-based assessments could potentially be used to automate the measurement of lower limb length and LLD in clinical practice. LEVEL OF EVIDENCE/UNASSIGNED:Level IV.

PURPOSE/OBJECTIVE:The purpose of this study is to investigate the anatomic distribution of bone marrow edema on MRI among patients who sustained a Segond fracture compared to those with an isolated ACL tear. METHODS:A retrospective cohort study was performed of patients aged 18-40 years old who presented with an acute isolated ACL tear between January 2012 and May 2022. Two blinded readers reviewed all knee MRIs to assess bone marrow edema using the Whole-Organ Magnetic Resonance Imaging Score and the area of each sub-compartment was scored. RESULTS:There were 522 patients in the final analysis, of which 28 patients (5.4%) were identified to have a Segond fracture. The Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central lateral femoral condyle, as well as the anterior, central, and posterior lateral tibial plateau. Furthermore, the Segond group demonstrated significantly greater rates of WORMS grades 2 and 3 in the central medial femoral condyle and the anterior medial tibial plateau. Bone edema at the central lateral femoral condyle (R = 0.034, p = 0.019) and central tibial plateau (R = 0.093, p = 0.033) were significantly correlated with lateral meniscus tears, while the edema in the posterior medial femoral condyle was correlated with medial meniscus tears (R = 0.127, p = 0.004). CONCLUSION/CONCLUSIONS:Patients who present with ACL tear and a concomitant Segond fracture demonstrate significantly more extensive bone marrow edema in both the medial and lateral compartments of the knee compared to patients with an isolated ACL tear.