Faculty Bibliography

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.

Compared with total hip arthroplasty, hip arthroscopy is a relatively new procedure and, as such, hip-spine syndrome in young adults is an emerging topic of research. In the past decade, our understanding of spinopelvic alignment has improved the stability and survivorship of hip replacements in patients with prior lumbar fusions. Obviously, the hip affects the spine and the spine affects the hip. In terms of hip arthroscopy, just as older patients and patients with cartilage damage have inferior outcome, patients with spine pathology are at risk for post-operative worsening spinal symptoms, including sciatica. In addition, back and radicular pain may limit post-operative hip rehabilitation. Yet, other patients show resolution of back symptoms after hip arthroscopy. Today, surgeons indicating hip arthroscopy must first investigate patient sagittal balance which includes pelvis tilt, pelvic incidence and sacral slope. When properly indicated, hip-spine pain patients show greater percentage improvement with no increased failure risk compared to patients with isolated FAIS. Exceptions include patients with concomitant lumbar stenosis or lumbar fusion. rate of revision hip arthroscopy and conversion for total hip replacement is two-fold compared to controls if patients had prior 1-2 level fusion and three-fold if 3 or more levels are fused. Our understanding of hip-spine patients with regard to arthroscopy outcomes continues to develop. In addition to a comprehensive spine exam, the patient's spine surgical history and current spine symptoms must be investigated in order to predit the efficacy of hip arthroscopy. If patients have both hip and spine symptoms, a diagnostic hip injection to determine the prime pain generator is essential. If the hip is the source of pain, patients should be counseled that back symptoms will likely improve after hip arthroscopy but not in all cases. EOS imaging to measure sagittal balance may allow the surgeon to predict if impingement measurements on hip x-rays may be underestimated in the setting of a stiff spine. If the patient has multiple risk factors for poor outcomes such as advancing age, articular cartilage damage, borderline dysplasia, hypermobility, on top of a history of multilevel lumbar fusion or spinal deformity, hip arthroscopy may not be ideal and hip arthroplasty should be considered. Clearly, the spine may not be ignored in patients with FAIS.

PURPOSE/OBJECTIVE:The aim of this study was to assess the inter-rater reproducibility and inter-method comparability of hip alpha angle measurements on magnetic resonance imaging (MRI)/magnetic resonance arthrography (MRA) and plain radiographs in patients with femoroacetabular impingement syndrome (FAIS). METHODS:A cross-sectional study of patients who were diagnosed with symptomatic FAIS underwent preoperative MRI/MRA with axial oblique and/or radial plane imaging and had preoperative radiographs with anterior-posterior (AP), 45° Dunn and 90° Dunn views. Alpha angle measurements were performed independently by two musculoskeletal radiologists. Inter-rater reproducibility and inter-method comparability between MRI/MRA images and radiographic views were assessed using the intraclass correlation coefficient (ICC) with 95% confidence interval (CI). RESULTS:Ninety-seven patients were included of whom 93 (95.8%) received axial oblique plane images and 54 (55.6%) had radial plane MRI/MRA images. Inter-rater reproducibility was excellent (ICC > 0.9) for all planes on MRI/MRA and radiographs. MRI/MRA axial oblique images had poor (ICC 0.39, 95% CI [0.09, 0.59]), moderate (ICC 0.57, 95% CI [0.18, 0.75]) and moderate (ICC 0.64, 95% CI [0.20, 0.81]) comparability with AP, 45° Dunn and 90° Dunn, respectively. MRI/MRA radial plane images had equivocal (0 included in all CIs) comparability with AP (ICC 0.66), 45° Dunn (ICC 0.35) and 90° Dunn (ICC 0.14) radiographs. On average, alpha angle measurements were significantly higher with radial images and lower with axial oblique images, when compared to all radiographic views (p < 0.05), except axial oblique versus 45° Dunn views, where angles measured on axial oblique were significantly larger. CONCLUSION/CONCLUSIONS:Alpha angle measurements taken on axial oblique MRI/MRA images show moderate comparability to radiographic 45° Dunn and 90° Dunn views despite negative bias to measurements taken on radiographic AP and 45° Dunn view. Larger alpha angles were appreciated on MRI/MRA radial and axial oblique views compared to radiographic views supporting the inclusion of MRI/MRA alpha angle measurements to properly identify deformity. LEVEL OF EVIDENCE/METHODS:Level II.

PURPOSE/OBJECTIVE:Proximal hamstring tears may present with neurological dysfunction due to compression or stretching of the sciatic nerve. The purpose of this study was to evaluate the effectiveness of hamstring repair with concurrent sciatic nerve neurolysis for clinical outcomes and patient symptoms. METHODS:A retrospective chart review of patients who were diagnosed with hamstring injury at a large tertiary care institution was conducted. Patients with chronic tears (> 6 weeks from injury to surgery) who underwent hamstring repair were reviewed for demographics, clinical variables including symptoms of sciatic neuritis, sciatic nerve abnormalities on MRI, and postoperative outcomes. Chi-square tests were used for categorical variables, t test for continuous variables. Pairwise t tests were used to compare average pre- and postoperative strength for patients with and without symptoms of sciatic neuritis. RESULTS:Thirty-two patients with chronic hamstring tears were included in the analysis. Patients were 59.4% female with an average age of 51.4 years (SD 13.1). Preoperatively, 27 patients (84.4%) were noted to have symptoms of sciatic neuritis. These patients did not differ in age (p = .677) or sex (p = .374) from patients without preoperative symptoms. Sciatic nerve abnormalities were noted on MRI report in 7 patients who had sciatic nerve symptoms and 0 patients who did not have sciatic nerve symptoms. Symptomatic improvement was seen in 21/26 (81%) of patients who had preoperative neurological symptoms, and in 6/7 (86%) of patients with MRI findings. All patients had equivalent or improved strength postoperatively. CONCLUSION/CONCLUSIONS:A sciatic nerve neurolysis is a safe and effective procedure to perform on patients with preoperative sciatic nerve symptoms and chronic hamstring tears that leads to improvement in neurological symptoms and strength. In neurologically asymptomatic patients with chronic hamstring injuries and MRI findings indicating possible nerve damage, a discussion should be held about the risks and benefits of performing a sciatic nerve neurolysis.

Different pathologies of the hip are characterized by the abnormal shape of the bony structures of the joint, namely the femur and the acetabulum. Three-dimensional (3D) models of the hip can be used for diagnosis, biomechanical simulation, and planning of surgical treatments. These models can be generated by building 3D surfaces of the joint's structures segmented on magnetic resonance (MR) images. Deep learning can avoid time-consuming manual segmentations, but its performance depends on the amount and quality of the available training data. Data augmentation and transfer learning are two approaches used when there is only a limited number of datasets. In particular, data augmentation can be used to artificially increase the size and diversity of the training datasets, whereas transfer learning can be used to build the desired model on top of a model previously trained with similar data. This study investigates the effect of data augmentation and transfer learning on the performance of deep learning for the automatic segmentation of the femur and acetabulum on 3D MR images of patients diagnosed with femoroacetabular impingement. Transfer learning was applied starting from a model trained for the segmentation of the bony structures of the shoulder joint, which bears some resemblance to the hip joint. Our results suggest that data augmentation is more effective than transfer learning, yielding a Dice similarity coefficient compared to ground-truth manual segmentations of 0.84 and 0.89 for the acetabulum and femur, respectively, whereas the Dice coefficient was 0.78 and 0.88 for the model based on transfer learning. The Accuracy for the two anatomical regions was 0.95 and 0.97 when using data augmentation, and 0.87 and 0.96 when using transfer learning. Data augmentation can improve the performance of deep learning models by increasing the diversity of the training dataset and making the models more robust to noise and variations in image quality. The proposed segmentation model could be combined with radiomic analysis for the automatic evaluation of hip pathologies.

PURPOSE OF REVIEW/OBJECTIVE:Gluteus medius and minimus tears, or hip abductor tendon tears, are increasingly identified as a source of lateral hip pain. Once underappreciated and undertreated, they are now recognized as a cause of greater trochanteric pain syndrome and a pathology amenable to both nonoperative and operative modalities. This review summarizes relevant anatomy, clinical presentation, and treatment options for gluteus medius tears, focusing on surgical options. RECENT FINDINGS/RESULTS:When surgical intervention is indicated, repair, reconstruction, or tendon transfer may be considered. Open and endoscopic repair techniques demonstrate similar outcomes with improvements in patient-reported outcomes and low complication and retear rates for both partial and full thickness tears. Variations in fixation construct and graft augmentations have been described, though clinical evidence remains limited to support specific techniques. Gluteus maximus transfer via open approach is a salvage option for the severely atrophied, retracted, or revision gluteus tendon; however, persistent limitations in abduction strength and gait abnormalities are common. Emerging evidence continues to evolve our understanding of surgical decision-making for gluteus tendon tears. The current literature supports either open or endoscopic repair techniques and open tendon transfer as a salvAage option. Further study is needed to determine the optimal fixation construct, the role of graft augmentation, and patient-related factors that influence postoperative outcomes.

Femoroacetabular impingement (FAI) is a cause of hip pain and can lead to hip osteoarthritis. Radiological measurements obtained from radiographs or magnetic resonance imaging (MRI) are normally used for FAI diagnosis, but they require time-consuming manual interaction, which limits accuracy and reproducibility. This study compares standard radiologic measurements against radiomics features automatically extracted from MRI for the identification of FAI patients versus healthy subjects. Three-dimensional Dixon MRI of the pelvis were retrospectively collected for 10 patients with confirmed FAI and acquired for 10 healthy subjects. The femur and acetabulum were segmented bilaterally and associated radiomics features were extracted from the four MRI contrasts of the Dixon sequence (water-only, fat-only, in-phase, and out-of-phase). A radiologist collected 21 radiological measurements typically used in FAI. The Gini importance was used to define 9 subsets with the most predictive radiomics features and one subset for the most diagnostically relevant radiological measurements. For each subset, 100 Random Forest machine learning models were trained with different data splits and fivefold cross-validation to classify healthy subjects versus FAI patients. The average performance among the 100 models was computed for each subset and compared against the performance of the radiological measurements. One model trained using the radiomics features datasets yielded 100% accuracy in the detection of FAI, whereas all other radiomics features exceeded 80% accuracy. Radiological measurements yielded 74% accuracy, consistent with previous work. The results of this preliminary work highlight for the first time the potential of radiomics for fully automated FAI diagnosis.

PURPOSE/OBJECTIVE:The volume of arthroscopic hip surgery has increased dramatically in recent years with iliopsoas tendinitis (IPT) being one of the most common complications of this procedure. The purpose of this study is to investigate the prevalence of post-operative IPT in patients who undergo arthroscopic hip surgery with capsular closure using absorbable versus non-absorbable suture. METHODS:, Johnson and Johnson, New Brunswick, NJ) suture and those who underwent capsular closure with non-absorbable suture (Suturetape, Arthrex, Naples FL). All patients who underwent primary or revision hip arthroscopy and were at least 2 months post-operation were initially included in the study. RESULTS:Between August 2007 and May 2023 a total of 1513 hip arthroscopy surgeries were performed. Within this cohort, 1421 hips underwent hip arthroscopy with non-absorbable suture and 64 hips underwent surgery with absorbable suture. There was no significant difference between the proportion of IPT in the non-absorbable cohort (2.3%) versus the absorbable cohort (1.6%) (P = 0.669). CONCLUSION/CONCLUSIONS:Capsular closure with Absorbable sutures was non-inferior to capsular closure with non-absorbable sutures with respect to the proportion of post-operative IPT following hip arthroscopy for FAI. Additionally, the proportion of post-operative IPT was found to be significantly higher in patients undergoing revision versus primary hip arthroscopy, regardless of capsular closure suture type. LEVEL OF EVIDENCE/METHODS:IV.