Faculty Bibliography

BACKGROUND:The minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) are valuable clinical thresholds used to provide clinical relevance to patient outcome scores. In hip arthroscopy (HA) for femoroacetabular impingement (FAI) syndrome, these values have been defined for the short- and midterm postoperative period, but meaningful long-term thresholds have not been established. PURPOSE/OBJECTIVE:To define the MCID, PASS, and SCB for the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) at a minimum follow-up of 10 years for patients who underwent HA for FAI syndrome. STUDY DESIGN/METHODS:Case series; Level of evidence, 4. METHODS:A retrospective cohort study including all patients who underwent primary HA for FAI with a single surgeon from February 2010 to December 2013 was performed. Patient outcomes were assessed with an anchor question, mHHS, and NAHS at baseline and at 1, 5, and 10 years of follow-up. MCID was calculated using the distribution-based method at all time points, using 0.5 standard deviations as the threshold. The anchor-based MCID, PASS, and SCB were calculated at 10 years using thresholds representing the optimal cutoff on a receiver operating characteristic curve. Correlations between baseline characteristics and achievement of the MCID, PASS, and SCB were assessed with binomial logistic regressions. RESULTS:= .01). CONCLUSION/CONCLUSIONS:The establishment of the MCID, SCB, and PASS for the NAHS and mHHS provides a valuable clinical context for improvements in outcome scores after HA. Anchor-based calculations were consistently higher than distribution-based calculations.

Acetabular cartilage delamination (ACD) can result in focal chondral defects, increasing contact stresses and contributing to osteoarthritis. This is commonly associated with femoroacetabular impingement, particularly with cam deformities due to shearing of the cam on the acetabulum. Additionally, ACD associated with labral tears or chondrolabral separation, when untreated, can compromise labral repair outcomes. ACD is often missed on preoperative magnetic resonance imaging and magnetic resonance arthrography, which show a sensitivity of <80%. Thus, given the ubiquity of ACD in patients undergoing femoroacetabular impingement surgery, a single-stage treatment option is essential. Acetabular shape, depth, and constraint, coupled with the thinness of acetabular cartilage, make treatment technically difficult, particularly arthroscopically. Treatment generally falls within 3 categories: repair, repair with augmentation, or cell-based cartilage transplantation. Currently, we most commonly employ primary repair and incorporate the cartilage flap into the labral repair. The chondral nail described by Zhu et al. is an intriguing off-the-shelf, single-stage technique that merits further investigation.

BACKGROUND:While both short- and long-term outcomes after hip arthroscopy for femoroacetabular impingement syndrome (FAIS) have been reported, the predictive relationship between the two has yet to be established. PURPOSE/OBJECTIVE:To determine whether the degree of improvement in patient-reported outcomes observed at 1 year postoperatively predicts long-term outcomes at 10 years after primary hip arthroscopy for FAIS. STUDY DESIGN/METHODS:Cohort study; Level of evidence, 3Methods:Patients who underwent primary hip arthroscopy for FAIS by a single surgeon at a single institution with 10-year follow-up were identified. Outcomes were assessed using the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) at baseline and 1, 2, 5, and 10 years postoperatively. Patients were classified as either high improvement (HI) or low improvement (LI) based on if they achieved the median 1-year change in mHHS from baseline. Chart review was performed to collect surgical details such as operative procedures, complications, and revision surgery. Outcomes were compared between groups over time using repeated-measures analysis of variance. Failure rates were determined using Kaplan-Meier and Mantel-Cox log-rank analyses. RESULTS:= .002). CONCLUSION/CONCLUSIONS:Patients who experienced greater improvement in the first year after hip arthroscopy had superior 10-year outcome scores, fewer complications, and lower rates of reoperation compared with those who experienced minimal improvement in the same period.

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.

Previous studies suggest a relationship between femoroacetabular impingement (FAI) and femoral neck stress fractures (FNSF), due to pathologic biomechanics in the setting of femoral head abutment (cam morphology) and/or acetabular overcoverage (pincer morphology). The purpose of this study is to evaluate the association between cam or pincer morphology and FNSF, compared to a control group of patients without hip pain. A retrospective review of the electronic medical record at a single institution was queried for patients with FNSF over a 10-year time period from January 2011-2021. These patients were compared to a control group with diagnostic radiographs and a chief complaint that was not hip pain presenting to the institution's emergency department. Hip morphology was evaluated radiographically. A multivariate logistic regression was used to investigate an association between FNSF and cam or pincer morphology. Eighty-three patients with FNSF and a mean age of 38.6 years were compared to 55 healthy controls with a mean age of 35.8 years. Patients in the FNSF group were more often female, white, and had lower BMI. These patients were also more likely to have associated cam morphology (p = 0.010). Binary logistic regression demonstrated a statistically significant independent association between both cam (OR 5.2, p = 0.01) and pincer (OR 4.6, p = 0.022) morphology with FNSF when controlling for demographic variables. Black race and higher BMI were protective factors for FNSF (OR 0.09, OR 0.84, p < 0.01). In summary, radiographic cam morphology, superolateral acetabular overcoverage, female sex, and lower BMI are risk factors for sustaining FNSF, while the black race was found to be protective.

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:The aim of this study is to assess agreement between retrospectively and prospectively collected patient-reported outcome measures (PROMs) following hip arthroscopy for femoroacetabular impingement syndrome (FAIS). METHODS:Patients undergoing hip arthroscopy from 2021 to 2023 for FAIS completed preoperative PROMs, including the modified Harris Hip Score (mHHS) and the Non-Arthritic Hip Score (NAHS). Post-operatively, patients were surveyed and asked to recall their preoperative hip function. Paired two-sample t tests were used to compare baseline and recalled baseline PROMs and the difference between scores was compared to previously published minimally clinically important difference (MCID) values. Intraclass correlation coefficients (ICCs) were calculated to test the reliability between scores based on a single-rater, two-way mixed-effects model. Multivariable regression, accounting for age, sex and preoperative baseline scores, was used to evaluate the relationship of time elapsed since surgery with recall accuracy. RESULTS:A total of 116 patients (age: 37.6 ± 11.8 years; 61.2% female) were included. The mean time elapsed for recalled data was 13.1 months (range: 1-27 months). Overall, patients' recalled scores were significantly lower than those prospectively collected (mHHS: 52.9 ± 20.1 vs. 61.5 ± 18.5, p < 0.0001; NAHS: 54.7 ± 20.0 vs. 58.8 ± 19.1, p < 0.0001). Frequency distribution found 68.1% of recalled mHHS and 61.2% of NAHS scores to have a greater difference (between baseline and recalled scores) than the MCID. The ICC was moderate for both mHHS (ICC = 0.559, 95% confidence interval [CI] = [0.420-0.672], p < 0.001) and NAHS (ICC = 0.612, 95% CI = [0.484-0.714], p < 0.001). Multivariate regression analysis did not find time elapsed since surgery to be associated with the difference between baseline and recalled mHHS (n.s.) or NAHS (n.s.). CONCLUSION/CONCLUSIONS:There are significant differences between retrospective and prospectively collected PROMs in patients undergoing hip arthroscopy that are not predicted by time to recall. These findings should impact the interpretation of the existing literature, support the routine collection of prospective data and inform patient counsel regarding their perceived post-operative outcomes. LEVEL OF EVIDENCE/METHODS:Level IV.

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.

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: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.