Faculty Bibliography

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).

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.

BACKGROUND:Increased Posterior Tibial Slope (PTS) angle has been reported to be a risk factor for primary anterior cruciate ligament (ACL) tears. However, it is unknown whether increased PTS has an associated increased risk for non-contact versus contact ACL injury. PURPOSE/OBJECTIVE:The purpose of this study is to determine whether patients with non-contact ACL injury have a higher PTS angle than those with contact ACL injury. METHODS:A total of 1700 patients who underwent primary ACL reconstruction between January 2011 and June 2023 at a single academic institution were initially included. Electronic medical records were reviewed for demographic information as well as evidence that the patient sustained a contact or non-contact ACL injury. Patients in the contact cohort were propensity score matched to patients in the non-contact cohort by age, sex and BMI. Additionally, patients in the contact cohort were then propensity score matched to a control group of patients with intact ACLs also by age, sex and BMI. RESULTS:One hundred and two patients with contact injury were initially identified and 1598 patients with non-contact injuries were identified. Of the 102, 67 had knee X-rays that were suitable for measurement. These 67 contact injury patients were propensity score matched to 67 noncontact patient and 67 patients with intact ACLs based on age, sex and BMI. There were no significant differences between contact and non-contact cohorts in age (28.7±6.3 vs. 27.1±6.5, p = 0.147), sex (Female: 36.0% vs. 34.3%, p = 0.858), or BMI (26.7±5.6 vs 26.1±3.4, p = 0.475). There was no significant difference in PTS angle between contact versus non-contact ACL injury patients (11.6±3.0 vs.11.6±2.8, p = 0.894). There was a significant difference in PTS between the contact ACL injury and the intact cohort (11.6±3.0 vs. 10.0±3.9, p = 0.010) and the non-contact ACL injury and the intact cohort (11.6±2.8 vs. 10.0±3.9, p = 0.010). CONCLUSION/CONCLUSIONS:There was no significant difference in the degree of PTS between patients who sustained contact versus non-contact ACL injuries. Additionally, there was a significantly increased PTS in both the contact and non-contact ACL injury cohorts compared to patients with intact ACLs.

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.

BACKGROUND/UNASSIGNED:Operative treatment of chronic exertional compartment syndrome (CECS) with fasciotomy is effective for symptomatic resolution, but outcomes at medium- to long-term follow-up are unclear. HYPOTHESIS/UNASSIGNED:Patients will have favorable satisfaction at medium- to long-term follow-up and a high return to sport (RTS) rate after fasciotomy for treatment of CECS. STUDY DESIGN/UNASSIGNED:Cross-sectional. LEVEL OF EVIDENCE/UNASSIGNED:Level 3. METHODS/UNASSIGNED:Retrospective review of patients who underwent fasciotomy for treatment of CECS from 2010 to 2021. Outcomes were assessed using Tegner Activity Scale, symptom resolution, patient satisfaction, return to activities, and EQ-5D-5L survey. RESULTS/UNASSIGNED:= 0.02) than those who had fasciotomy of >3 compartments; 19 (38.0%) patients reported experiencing paresthesia after their operation. No patients experienced major complications. CONCLUSION/UNASSIGNED:Medium- to long-term outcomes of patients with CECS treated with fasciotomy demonstrated high satisfaction levels and high RTS rate. However, rate of minor complications including paresthesia, swelling, and cramping was high.

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/UNASSIGNED:To analyze the effects of 1 or more patient-reported allergies on clinical outcomes, in particular graft failure rate, and patient-reported outcomes (PROs) following osteochondral allograft transplantation (OCA) of the knee. METHODS/UNASSIGNED:Retrospective review of patients who underwent knee OCA from August 2010 to May 2021 with a minimum of 2-year follow-up. Patients were initially divided into 2 cohorts: those with at least 1 allergy and those without any allergies. Clinical outcomes assessed included graft failure, reoperation rates, deep vein thrombosis/pulmonary embolism, and manipulation under anesthesia/lysis of adhesions (MUA/LOA). PROs assessed, including the visual analog scale (VAS) for pain and satisfaction, the Knee injury and Osteoarthritis Outcome Score (KOOS), and return to sport rates, were compared. RESULTS/UNASSIGNED: = .022). There was no difference in rate of reoperation, complications, infection, and MUA/LOA. Of the 100 patients who completed PROs, there was no difference in VAS satisfaction, pain, and any of the KOOS outcome scores or return to sport. CONCLUSIONS/UNASSIGNED:The presence of 1 or more patient-reported allergies was shown to be significantly associated with OCA graft failure. Furthermore, an increasing number of patient-reported allergies were associated with a higher rate of graft failure. However, there were no significant differences in VAS satisfaction or pain, KOOS symptom, quality of life, pain, or return to sport in patients with at least 1 patient-reported allergy and those without allergies. LEVEL OF EVIDENCE/UNASSIGNED:Level III, retrospective cohort study.

PURPOSE/OBJECTIVE:The purpose of this study was to identify sex differences in postoperative outcomes and return-to-sport rates after fasciotomy for treatment of chronic exertional compartment syndrome (CECS) of the lower leg. It was hypothesised that male CECS patients would have a higher rate of return to sport than female CECS patients. METHODS:A retrospective cohort study was conducted involving patients who underwent primary fasciotomy of one to four leg compartments for treatment of CECS at a single centre from 2010 to 2020. Each affected leg was treated as a separate subject. Postoperative outcomes included CECS pain frequency and severity, return to sport and Tegner activity level. Multivariable regression was used to determine if sex was an independent predictor of outcomes after adjusting for demographic and clinical covariates. p < 0.05 were considered significant. RESULTS:Eighty-one legs (44 M, 37 F) of 47 unique patients (34 of whom had bilateral symptoms) were included with a mean follow-up time of 51.5 ± 31.4 months. Male subjects were older (p < 0.001) and had higher body mass index (p < 0.001) compared to female subjects. Most subjects (84.0%) underwent two- or four-compartment fasciotomies. Female sex was found to be predictive of lower overall postoperative pain severity (p = 0.007), higher odds of return to sport (p = 0.04) and higher postoperative Tegner score (p = 0.005). However, female sex was not predictive of postoperative pain frequency, odds of reoperation or odds of return to sport to at least the presymptomatic level (all p < 0.05). CONCLUSION/CONCLUSIONS:Female sex is independently predictive of reduced overall pain severity, higher odds of return to sport and higher postoperative improvement in Tegner score following fasciotomy for treatment of lower-limb CECS. LEVEL OF EVIDENCE/METHODS:III.

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.