Faculty Bibliography

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: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: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/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.

It is important to highlight the use of patient-specific cutting guides for knee joint osteotomies. Rationale, pitfalls, and planning of conventional osteotomy techniques are examined. The benefits of using patient-specific guides focusing on the potential for improved accuracy, efficiency, and safety are reviewed. The versatility of guides to manipulate the slope in both the coronal and sagittal planes, as well as its ability to accommodate concomitant procedures, is discussed. The time and cost differentials between standard cutting guides and three-dimensional-guided templating are also discussed.

PURPOSE/UNASSIGNED:To compare psychological readiness to return to sport (RTS), RTS rate, level of return, and time to return between patients who underwent bilateral anterior cruciate ligament reconstruction (ACLR) and those who underwent unilateral ACLR. METHODS/UNASSIGNED:The electronic medical record at a single academic medical center was queried for patients who underwent ACLR from January 2012 to May 2020. The inclusion criteria were skeletally mature patients who underwent either single or sequential bilateral ACLR and who had undergone either the primary ACLR or second contralateral ACLR at least 2 years earlier. Bilateral ACLRs were matched 1:3 to unilateral reconstructions based on age, sex, and body mass index. Psychological readiness to RTS was assessed using the validated ACL Return to Sport After Injury (ACL-RSI) scale. This, along with time to return and level of RTS, was compared between the 2 cohorts. RESULTS/UNASSIGNED: = .31) between the 2 cohorts. CONCLUSIONS/UNASSIGNED:Compared with patients who undergo unilateral ACLR, patients who undergo bilateral ACLR are equally as psychologically ready to RTS, showing equal rates of RTS, time to return, and level of return. LEVEL OF EVIDENCE/UNASSIGNED:Level III, retrospective cohort study.

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.

OBJECTIVES/OBJECTIVE:The purpose of this study was to compare clinical outcomes of medial quadriceps tendon-femoral ligament reconstruction (MQTFLR) and medial patellofemoral ligament reconstruction (MPFLR) among patients with recurrent lateral patellar instability. METHODS:A retrospective matched-cohort study was conducted involving patients who underwent MQTFLR or MPFLR with or without tibial tubercle osteotomy (TTO) from 2019 to 2021. Subjects were matched 1:1 on age, concomitant osteochondral allograft (OCA), concomitant TTO, and follow-up time. Measured outcomes included 90-day complications, Visual Analog Scale (VAS) knee pain, return to sport/work, Kujala score, Tegner score, and MPFL-Return to Sport after Injury (MPFL-RSI) score. Outcomes were compared between groups using Mann-Whitney U-test for continuous variables and Fisher's exact test for categorical variables. P-values <0.05 were considered significant. RESULTS:Ten MQTFLR patients (mean age 28.7 years, 80% female, mean follow-up 19.7 months) and ten MPFLR patients (mean age 29.1 years, 90% female, mean follow-up 28.3 months) were included in the study. One MQTFLR patient (10%) and three MPFLR patients (30%) underwent reoperation for postoperative arthrofibrosis. Postoperative VAS resting pain was not significantly different between the groups (MQTFLR mean 1.1, MPFLR mean 0.6, p ​= ​0.31). There were no significant differences in rates of recurrent subluxations (MQTFLR 20%, MPFLR 0%, p ​= ​0.47), return to sport (MQTFLR 50%, MPFLR 75%, p ​= ​0.61), return to work (MQTFLR 100%, MPFLR 88%, p ​= ​1.00), or MPFL-RSI pass rate (MQTFLR 75% vs. MPFLR 38%, p ​= ​0.31). CONCLUSION/CONCLUSIONS:There were no significant differences in knee pain and function, return to work, and rates of recurrent patellar instability between patients who underwent MQTFLR versus MPFLR, though these results should be interpreted with caution given the small sample size and potential selection bias. LEVEL OF EVIDENCE/METHODS:III.

BACKGROUND/UNASSIGNED:There has been a marked increase in the number of Schenck knee dislocation (KD) I injuries reported in the multiligament knee (MLK) injury (MLKI) and KD literature. PURPOSE/UNASSIGNED:To examine the heterogeneity of the Schenck KD I classification in the MLKI and KD literature. STUDY DESIGN/UNASSIGNED:Systematic review; Level of evidence, 4. METHODS/UNASSIGNED:A systematic literature search of PubMed, CINAHL, Scopus, Web of Science, EMBASE, and Cochrane Library was conducted for all studies that investigated KDs and/or MLKIs, utilized the Schenck or an MLKI classification system, and included patients with KD I or MLK 1 injuries. Pooled analysis determined the total number of KD I or MLK 1 injuries and the specific ligamentous tear patterns. Binary meta-analyses of the studies that reported neurovascular injury within each Schenck KD class compared the pooled odds ratio (OR) of vascular and neurological injury in unicruciate (KD I) and bicruciate (KD II-IV) injuries. RESULTS/UNASSIGNED:< .00001). CONCLUSION/UNASSIGNED:The number of true, clinically and/or radiographically confirmed unicruciate KDs was extremely rare, representing <1% of all reported Schenck KD I injuries. A misappropriation of these injury patterns as true KDs may be taking place, affecting outcome studies and potentially biasing published clinical results. An MLKI classification system must document whether a confirmed KD has occurred.

Tibial-sided posterior cruciate ligament avulsion fractures are challenging injuries that often occur concomitantly in the setting of multiligament knee and other soft-tissue injuries. There is no consensus on the optimal surgical approach or timing of treatment for these injuries. This Technical Note describes the fixation of a displaced posterior cruciate ligament avulsion fracture with concomitant grade 3 medial collateral ligament injuries and bucket-handle lateral meniscus tears using open and arthroscopic techniques. This method allows the surgeon to address multiple pathologies in a single stage, although it requires strategic planning and rehabilitation considerations.