Faculty Bibliography

PURPOSE/OBJECTIVE:To determine the mHHS and NAHS at 2 year follow up in patients that underwent staged bilateral hip arthroscopy versus age, sex, and Body Mass Index (BMI) matched patients that underwent unilateral hip arthroscopy. METHODS:Patients that underwent staged bilateral primary hip arthroscopy between January 2007 to December 2017 for the indication of Femoroacetabular Impingement (FAI) with a minimum 2 year follow-up were identified. The control group was comprised of patients that underwent a unilateral hip arthroscopy for FAI. The modified Harris Hip Score (mHHS) and the Non-Arthritic Hip Score (NAHS) were analyzed. RESULTS:Forty-two patients (84 hips) in the bilateral group were matched with 84 patients (84 hips) in the unilateral group. Both groups had significantly improved mHHS and NAHS when comparing preoperative scores to postoperative scores (bilateral group mHHS: 45.5 ± 15.1 to 81.7 ± 17.6, p <0.0001, bilateral group NAHS: 49.5 ± 13.8 to 83.6 ± 20.0, p <0.0001, unilateral group mHHS 48.5 ± 13.8 to 83.6 ± 15.9, p <0.0001, unilateral group NAHS 48.8 ± 12.0 to 85.0 ± 16.6, p <0.0001). The patient acceptable symptomatic state (PASS) was achieved in 57 hips (68%) in the bilateral group vs 62 hips (74%) in the unilateral group, p =0.4. Patients with bilateral hip arthroscopy that had < 17 months between index procedure and contralateral hip arthroscopy had significantly better mHHS and NAHS (85.5 ± 18.4 vs 75.71 ± 14.4, p = 0.013 for mHHS and 88.1 ± 17.1 vs 76.2 ± 22.4, p = 0.0074 for NAHS). CONCLUSIONS:Bilateral hip arthroscopy for the indication of FAI has improved mHHS and NAHS at 2 years of follow up compared to baseline. There was no difference in 2 year mHHS and NAHS in patients that underwent bilateral hip arthroscopy and unilateral hip arthroscopy. Patients in the bilateral hip arthroscopy group that had the contralateral surgery longer than 17 months from index procedure had lower 2 year follow up mHHS and NAHS scores than those that underwent the second surgery within 17 months of the index procedure.

BACKGROUND/UNASSIGNED:Iliopsoas tendinitis is a known source of extra-articular hip pain and it has been shown to be a common cause of continued hip pain following total hip arthroplasty. While iliopsoas tendinitis after hip arthroscopy is a well-known phenomenon amongst hip arthroscopists, its presentation, course, and treatment has yet to be elucidated. METHODS/UNASSIGNED:An IRB-approved chart review was performed of patients undergoing hip arthroscopy for femoroacetabular impingement (FAI) between March 2015 and July 2017. No cases of dysplasia were included. All patients had combined cam/pincer impingement as well as labral pathology. Tendinitis patients were identified. Patient demographics, surgical data, time to onset/diagnosis of iliopsoas tendinitis, treatment (oral anti-inflammatories, corticosteroid injection, physical therapy), and resolution of symptoms were recorded. These cases were age- and sex-matched to a control group that did not develop postoperative iliopsoas tendinitis for comparison. Patient outcomes were measured with the modified Harris Hip Score (mHHS) and Nonarthritic Hip Score (NAHS) recorded from the preoperative and 1-year postoperative visits. RESULTS/UNASSIGNED: = 0.09) scores at their 1-year postoperative visits. CONCLUSIONS/UNASSIGNED:Iliopsoas tendinitis is a common source of pain following arthroscopic hip surgery and can be effectively diagnosed and treated with ultrasound-guided injection. Therefore, surgeons performing arthroscopic procedures of the hip must remain aware of and include it in their differential when encountering patients with hip flexion pain after surgery. Research should be continued to further evaluate the long-term outcomes and return to sport rates of these patients.

PURPOSE/OBJECTIVE:To evaluate post-operative outcomes and pre-operative risk factors for patients with underlying systemic inflammatory disorders (SID) after hip arthroscopy. METHODS:A retrospective analysis of patients that had undergone hip arthroscopy, with a history of systemic inflammatory disease. This included patients with a diagnosis of lupus, positive ANA, rheumatoid arthritis, psoriatic arthritis, sarcoidosis, inflammatory bowel disease, Reiter Syndrome, mixed connective tissue disease (MCTD). These cases were 1:2 matched to a control group of patients with no history of systemic inflammatory disease based on age and sex. An a-priori power analysis was conducted and A 1:2 case-control ratio was selected in order to increase study power. Inclusion criteria included all skeletally-mature patients with hip pain refractory to non-operative management who underwent hip arthroscopy for labral tears and femoroacetabular impingement (FAI). Skeletally immature patients, those with Tonnis grades of 2 or more (less than 2mm of joint space), hip dysplasia, patients undergoing revision hip arthroscopy, and patients whose pain failed to improve after intra-articular injection were excluded. The primary outcome was rate of revision hip arthroscopy or total hip arthroplasty 24 months after surgery. Secondary outcomes included two patient-reported outcome (PRO) scores, modified Harris Hip Scores (mHHS) and Non-Arthritic Hip Scores (NAHS). RESULTS:Twenty patients (21 hip arthroscopy procedures) and 42 controls were included. There was no significant difference in proportion of patients who met failure criteria (28.6% vs 16.7%,p=0.271) or two-year survivorship (76.2% vs 83.3%, p=0.496) between the SID and control groups, respectively. Both groups had a significant improvement in modified Harris Hip Scores (mHHS) and Non-Arthritic Hip Scores (NAHS) at 24-months compared to baseline, however, there was no significant difference in mHHS (p=0.28) or NAHS (p=0.22) at 24-months between the two groups. CONCLUSION/CONCLUSIONS:Patients with underlying inflammatory conditions have similar 2-year outcomes after hip arthroscopy for intra-articular pathology compared to patients with no history of inflammatory disease. LEVEL OF EVIDENCE/METHODS:This is a retrospective comparative study, Level of Evidence III.

PURPOSE/OBJECTIVE:To determine if magnetic resonance angiography (MRA) and/or magnetic resonance imaging (MRI) could accurately determine the width of the labrum. METHODS:Consecutively enrolled patients between the ages of 18 and 65 indicated for hip arthroscopy for femoroacetabular impingement were included between December 2017 and June 2018. Inclusion criteria for preoperative MRIs included: MRI availability in picture archiving and communication system; performance on a 1.5T or 3T MRI or 3T MRA; and adequate quality and lack of labrum ossification. Intraoperative labral width measurements were taken at standardized locations using an established acetabular "clockface" paradigm. Measurement was performed using a calibrated probe. The labral width was defined as the distance from the labrum extended laterally from the acetabular rim. MRI measurements were taken by 2 blinded musculoskeletal fellowship-trained radiologists at the same positions. Measurements were made at the 11:30 o'clock position (indirect rectus) on coronal proton density (PD) sequence, at 3 o'clock position (psoas-U) on axial oblique PD sequence, and at 1:30 (a point halfway between the 2) on sagittal fat-suppressed PD. The surgeons were blinded to the radiologists' measurements and vice versa. Intraoperative and radiographic labral width measurements were compared using an intraclass correlation coefficients (ICC), absolute agreement, and 2-way random effects model. The 2 radiologists' measurements were compared for interrater reliability using the same ICC model. RESULTS:Fifty-one patients were included (30 females, 26 right hips). Average labrum width at the 3:00, 11:30, and 1:30 o'clock positions by arthroscopic measurement were 5.8 mm (range; standard deviation, 2-8; ±1.4), 6.3 mm (2-10; ±1.5) and 6.0 mm (2-9; ±1.5), and by MRI were 6.3 mm (2-10; ±1.5), 6.7 mm (3-10; ±1.4), and 6.1 mm (2-9; ±1.6), respectively. When including all MRI modalities, ICC agreement between intraoperative assessment, and radiologist assessment at the 3:00 o'clock, 11:30, and point halfway between was 0.82 (P < .001), 0.78 (P < .001), 0.84 (P < .001), respectively. Radiologist interrater ICC agreement at the same points was 0.88 (P < .001), 0.93 (P < .001), and 0.88 (P < .001). CONCLUSIONS:Strong agreement was found between radiologic and arthroscopic measurement of labrum width when using MRI, suggesting MRI is an accurate way to measure labral width. There was not a significant difference between different MRI modalities. Accurately measuring labral width preoperatively with MRI may aid in surgical decision making. LEVEL OF EVIDENCE/METHODS:Level II, diagnostic study.

PURPOSE/OBJECTIVE:To determine whether patients who reported a discrete traumatic event precipitating the onset of femoroacetabular impingement syndrome (FAIS) reported similar patient-reported outcomes for the modified Harris Hip Score (mHHS) and the Non-Arthritic Hip Score (NAHS) following hip arthroscopy as patients with atraumatic hip pain associated with FAIS alone. METHODS:A retrospective comparative therapeutic investigation of a prospectively collected database of cases performed by a single surgeon from 2010 to 2015 identified a group of patients who developed FAIS after a discrete traumatic event. This group was compared 1:2 with a body mass index and age-matched group of primary hip arthroscopies with atraumatic hip pain attributed to FAIS. Preoperative mHHS and NAHS were obtained and compared with those at 2-year follow-up. Clinical failure at 2 years was defined as any further ipsilateral hip surgery including revision arthroscopy and conversion to arthroplasty. RESULTS:In the traumatic etiology group, the mean mHHS and NAHS improved from 49.6 to 82.7 (P < .001) and from 46.9 to 84.0 (P < .001), respectively. The mean mHHS and NAHS in the atraumatic group improved from 51.5 to 85.82 (P < .001) and from 49.3 to 85.2 (P < .001), respectively. Survivorship at 2 years was 81.1% for traumatic etiology and 88.3% for atraumatic etiology; adjusted proportional hazards regression analysis demonstrated a difference in survivorship that was not statistically significant between the traumatic and atraumatic cohorts (hazard ratio 1.8, 95% confidence interval 0.8-4.0). CONCLUSIONS:The findings of this study demonstrate that patients presenting with FAIS and history of a traumatic hip injury can expect to experience similar good outcomes at 2 years following primary hip arthroscopy as compared with patients with atraumatic FAIS. LEVEL OF EVIDENCE/METHODS:Level III (Therapeutic) retrospective comparative study.

PURPOSE/OBJECTIVE:To determine when patients reach critical thresholds of clinical improvement after hip arthroscopy for femoroacetabular impingement (FAI) using previously defined cutoffs for the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) and to identify risk factors for prolonged recovery. METHODS:Consecutive patients with a diagnosis of FAI who underwent unilateral hip arthroscopy between January 2010 and January 2015 with at least 2 years of clinical follow-up were studied. The modified Harris Hip Score was collected prospectively at 6 consecutive time points. The number of patients reaching the MCID and PASS at each time point was determined. RESULTS:During the study period, 340 consecutive hip arthroscopies were performed in 316 patients with a mean final follow-up period of 50 months (range, 29-84 months). The mean modified Harris Hip Score and percentage of patients reaching the MCID and PASS increased at each time point. At 2 years, 271 patients (93%) surpassed the MCID and 212 patients (73%) achieved the PASS. Female sex, age of 40 years or older, and body mass index of 30 or greater were associated with lower rates of achieving the MCID and PASS at set time points. Patients undergoing labral repair had superior PASS rates at 3 months and beyond than patients undergoing labral debridement alone. Patients who did not achieve the PASS by 3 months were more likely to require reoperation. CONCLUSIONS:Hip arthroscopy for FAI results in increased patient-reported outcome measures at interval follow-up. Most patients reach critical thresholds of minimal and satisfactory clinical improvement. Patients who are female, older, or obese or who undergo labral debridement alone are less likely to reach these milestones at major time intervals. Patients who do not reach the PASS by 3 months are more likely to require reoperation. LEVEL OF EVIDENCE/METHODS:Level IV, therapeutic case series.

BACKGROUND/UNASSIGNED:Patients with symptomatic femoroacetabular impingement (FAI) typically have anterior groin pain. However, a subset of these patients may have pain located laterally, posteriorly, or in a combination of locations around the hip. PURPOSE/UNASSIGNED:To report and compare outcomes of hip arthroscopy for patients with FAI and atypical hip pain versus classic anterior groin pain. STUDY DESIGN/UNASSIGNED:Cohort study; Level of evidence, 2. METHODS/UNASSIGNED:Consecutive patients undergoing hip arthroscopy for FAI between August 2011 and March 2013 were identified. A total of 258 patients were identified as having symptomatic FAI based on clinical, radiographic, and advanced imaging diagnosis of FAI. Exclusion criteria included isolated thigh, knee, or low back pain. We also excluded patients with hip abductor pathology and trochanteric bursitis. Of the 226 patients ultimately included, 159 (70.4%) reported anterior groin pain, while 67 (29.6%) reported isolated lateral or posterior hip pain or a combination of locations. Patients were categorized into 4 groups: isolated anterior groin pain, lateral hip pain, posterior hip pain, and multiple primary hip pain locations (combined). These patients were followed prospectively with a minimum follow-up of 2 years. Patient characteristics, surgical characteristics, modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), revision hip arthroscopy, and conversions to total hip arthroplasty (THA) were recorded. RESULTS/UNASSIGNED:All 226 patients were included at final follow-up. Hip arthroscopy was performed by a single sports medicine fellowship-trained orthopaedic surgeon. Preoperative patient characteristics and baseline functional outcome scores did not significantly differ among groups. All 4 groups showed statistically significant improvements in mHHS and NAHS from baseline to final follow-up of a mean 2.63 years (range, 2.01-3.23 years). Functional outcome scores and rates of revision hip arthroscopy or conversion to THA did not significantly differ between groups. CONCLUSION/UNASSIGNED:Hip arthroscopy can effectively improve patient outcomes in atypical hip pain. A careful history and physical examination should identify this clinically meaningful subset of patients with FAI who can benefit from surgical intervention while identifying patients with concomitant posterior extra-articular hip or spine pathology that should be addressed appropriately.

Background The MRI manifestations of subspine impingement (SSI) other than morphologic features of anterior inferior iliac spine (AIIS) have not been extensively explored and validated. Purpose To determine the MRI findings associated with SSI, including AIIS morphologic features, femoral distal cam, and associated soft-tissue injuries. Materials and Methods This is a retrospective study of symptomatic patients who underwent arthroscopic treatment for femoroacetabular impingement between December 2014 and March 2017, with preoperative MRI within 6 months before surgery. The SSI group included patients with clinical and intraoperative findings of SSI; the remaining patients comprised the non-SSI group. Preoperative MRI findings were independently assessed by two radiologists who were blinded to clinical information. Interreader agreement was assessed, and multivariable logistic regression was also used. Results A total of 62 patients (mean age ± standard deviation, 42.1 years ± 11.9; 38 women) were included. SSI was diagnosed in 20 of the 62 patients (32%) (mean age, 43 years ± 12); 42 patients (68%) did not have SSI (mean age, 41 years ± 10). Reader 1 detected distal cam in 16 of the 20 patients with SSI (80%) and eight of the 42 patients without SSI (19%), and reader 2 detected distal cam in 15 of the 20 patients with SSI (75%) and eight of the 42 patients without SSI (19%) (P < .001 for both). Reader 1 detected signs of impingement on the distal femoral neck (IDFN) in 18 of the 20 patients with SSI (90%) and seven of the 42 patients without SSI (16%), and reader 2 detected signs of IDFN in 13 of the 20 patients with SSI (65%) and nine of the 42 patients without SSI (21%) (P < .001 and P = .001, respectively). Reader 1 detected superior capsular edema in 15 of 20 patients with SSI (75%) and three of 42 patients without SSI (7%), and reader 2 detected superior capsular edema in 17 of 20 patients with SSI (85%) and 22 of 42 patients without SSI (52%) (P < .001 and P = .02, respectively). Distal cam was a predictor of SSI after adjustment for IDFN. Interreader agreement was substantial for distal cam (κ = 0.80) and moderate for IDFN (κ = 0.50). Conclusion Soft-tissue injuries and osseous findings other than morphologic features of the anterior inferior iliac spine were associated with subspine impingement. © RSNA, 2019 See also the editorial by Guermazi in this issue.

Objectives: Bone Marrow Lesions (BML) are a common finding on knee MRI. In the knee, BML have a strong correlation to patient-reported pain, function, joint deterioration and rapid progression to TKR. Histologic analyses of BML have demonstrated findings consistent with fracture and bony remodeling of the trabeculae. The Subchondroplasty (SCP) Procedure aims to treat the bone defects present in the BML by percutaneously filling them with a bone substitute material, designed to flow through intact bone, harden at body temperature and then heal through natural bone turnover. Previous retrospective, single-center case series have demonstrated improvements in patient-reported outcomes. The purpose of this prospective, multi-center study is to evaluate the 2- year clinical and radiographic outcomes of patients with BML of the knee treated with the Subchondroplasty Procedure.
Method(s): Seventy patients were treated between 2012 and 2017 for BML of the tibial plateau and/or femoral condyle. Self-drilling cannulas were inserted into the BML using arthroscopic and fluoroscopic guidance, then injected with AccuFill Bone Substitute Material. All patients also underwent arthroscopy to aid in targeting the underlying bony lesion and address intra-articular pathology. MRIs and radiographs were obtained pre-operatively, at 6, 12 and 24 months, with additional radiographs collected at 6 weeks and 3 months. Patient-reported outcomes, including VAS pain, IKDC and KOOS were collected pre-operatively, 2 and 6 weeks, and 3, 6, 12 and 24 months post-operatively.
Result(s): Seventy patients (36 males and 34 females), average age 57 were consented and enrolled in the study. Preoperative K-L grade included 1.4% Grade 0, 2.9% Grade 1, 27.1% Grade 2, 55.7% Grade 3 and 7.1% Grade 4. Fifty eight tibial plateaus and 41 femoral condyles were treated (29 bipolar lesions treated). VAS Pain scores improved from a mean of 6.2/10 pre-op to 2.9/10 at 1 year. IKDC scores improved from mean 33.9 pre-op to 61.3 at 1 year. KOOS scores improved from baseline to 1 year (Fig. 1) with mean KOOS Pain from 45.8 to 73.9, ADL 52.9 to 79.2, Symptoms 49.7 to 71.9, Sports 21.2 to 49.9 and Quality of Life 18.1 to 52.3. All patient-reported outcomes showed statistically significant improvement at one year. Two year outcomes collected to date appear to follow the same trend. The last study subject is due to return in January 2019 at which point the final 2 year analysis will be completed. Six patients (8.6%) converted to arthroplasty (1 UKA and 5 TKA) at one year. To date, the 24 month conversion rate is 16.1% out of 62 subjects. The final conversion rate for 24 months will be calculated after the final subject returns. Radiographs and MRIs demonstrated good incorporation of the AccuFill material through 12 months with evidence of early remodeling and a lack of OA progression in the majority of subjects. Twenty-four month MRIs demonstrate continued remodeling of the AccuFill material.
Conclusion(s): This study presents statistically and clinically-meaningful evidence of improvements in clinical outcomes following Subchondroplasty procedure for BML of the knee. The low conversion rate suggests this lessinvasive procedure may delay the need for knee arthroplasty. MR imaging demonstrates good incorporation of the BSM and evidence of remodeling and reduction in material volume over time

OBJECTIVE:The outcome of arthroscopic treatment for femoroacetabular impingement (FAI) depends on the preoperative status of the hip cartilage. Quantitative T2 can detect early biochemical cartilage changes, but its routine implementation is challenging. Furthermore, intrinsic T2 variability between patients makes it difficult to define a threshold to identify cartilage lesions. To address this, we propose a normalized T2-index as a new method to evaluate cartilage in FAI. DESIGN/METHODS:We retrospectively analyzed magnetic resonance imaging (MRI) data of 18 FAI patients with arthroscopically confirmed cartilage defects. Cartilage T2 maps were reconstructed from multi-spin-echo 3-T data using the echo-modulation-curve (EMC) model-based technique. The central femoral cartilage, assumed healthy in early-stage FAI, was used as the normalization reference to define a T2-index. We investigated the ability of the T2-index to detect surgically confirmed cartilage lesions. RESULTS:The average T2-index was 1.14 ± 0.1 and 1.13 ± 0.1 for 2 separated segmentations. Using T2-index >1 as the threshold for damaged cartilage, accuracy was 88% and 100% for the 2 segmentations. We found moderate intraobserver repeatability, although separate segmentations yielded comparable accuracy. Damaged cartilage could not be identified using nonnormalized average T2 values. CONCLUSIONS:This preliminary study confirms the importance of normalizing T2 values to account for interpatient variability and suggests that the T2-index is a promising biomarker for the detection of cartilage lesions in FAI. Future work is needed to confirm that combining T2-index with morphologic MRI and other quantitative biomarkers could improve cartilage assessment in FAI.