Arthroscopic Treatment and Outcomes of Borderline Dysplasia With Acetabular Retroversion: A Matched-Control Study From the MASH Study Group

Background: Although acetabular retroversion (AR) occurs in dysplasia, management of the crossover sign (COS) or outcomes in borderline dysplasia (BD) with AR have not been reported. Purpose: To report any differences in the management of the COS in BD and nondysplastic hips and to report comparative outcomes of BD with AR with matched controls with BD or AR (ie, focal pincer femoroacetabular impingement [FAI]). Study design: Cohort study; Level of evidence, 3. Methods: A multicenter matched-pair study was performed with data from a large prospectively collected database. Inclusion criteria were patients who had undergone primary unilateral hip arthroscopy including labral repair for FAI and/or chondral pathology without significant osteoarthritis (ie, Tönnis grade 0 or 1). The study group (BD+AR) was defined radiographically by lateral center-edge angle (LCEA) on standing anteroposterior pelvis of 18° to 25° and positive COS. A 1:1:1 matching on age, sex, and body mass index was performed with a control group with BD and another control group with AR (LCEA, >25°+COS). Acetabuloplasty rates were determined for each group. Mean 2-year outcomes including the 12-Item International Hip Outcome Tool (iHOT-12), minimally clinical important difference (MCID), substantial clinical benefit (SCB), and Patient Acceptable Symptom State (PASS) scores were compared. Subanalysis of the study group both with and without acetabuloplasty was performed. Results: There were 69 patients, with 23 in the study group and 23 in each control group. The effect of dysplasia with or without the presence of the COS resulted in changes in acetabuloplasty rates, with 0% performed in the BD group, 35% in the BD+AR study group, and 91% in the AR group ( P = .001). Arthroscopic outcomes demonstrated similar and significant mean 2-year improvement of iHOT-12 patient-reported outcomes, MCID, SCB, and PASS scores in the study and both control groups. There was a trend within the study group toward greater postoperative iHOT-12 scores in patients who received anterior-based acetabuloplasty than those who did not receive acetabuloplasty (81.7 and 70.4, respectively; P = .11). Conclusion: Acetabular coverage influences the management of the COS, with significantly lower acetabuloplasty rates in BD with AR compared with AR without BD (focal pincer impingement). Symptomatic patients with combined BD and AR had similar significant successful outcomes to those of patients with BD and those with AR (focal pincer impingement), whether treated without acetabuloplasty or, less frequently, with limited anterior-based acetabuloplasty.

Acetabular Cartilage Thickness Differs Among Cam, Pincer, or Mixed-Type Femoroacetabular Impingement: A Descriptive Study Using In Vivo Ultrasonic Measurements During Surgical Hip Dislocation

Objective To investigate acetabular cartilage thickness among (1) 8 measurement locations on the lunate surface and (2) different types of femoroacetabular impingement (FAI). Design Prospective descriptive study comparing in vivo measured acetabular cartilage thickness using a validated ultrasonic device during surgical hip dislocation in 50 hips. Measurement locations included the anterior/posterior horn and 3 locations on each peripheral and central aspect of the acetabulum. The clock system was used for orientation. Thickness was compared among cam (11 hips), pincer (8 hips), and mixed-type (31 hips) of FAI. Mean age was 31 ± 8 (range, 18-49) years. Hips with no degenerative changes were included (Tönnis stage = 0). Results Acetabular cartilage thickness ranged from 1.7 mm to 2.7 mm and differed among the 8 locations ( P < 0.001). Thicker cartilage was found on the peripheral aspect at 11 and 1 o’clock positions (mean of 2.4 mm and 2.7 mm, respectively). At 5 out of 8 locations of measurement (anterior and posterior horn, 1 o’clock peripheral, 12 and 2 o’clock central), cartilage thickness was thinner in hips with pincer impingement compared to cam and/or mixed-type of FAI ( P ranging from <0.001 to 0.031). No difference in thickness existed between cam and mixed-type of impingement ( P = 0.751). Conclusion Acetabular cartilage thickness varied topographically and among FAI types. This study provides first baseline information about topographical cartilage thickness in FAI measured in vivo. Thinner cartilage thickness in pincer deformities could be misinterpreted as joint degeneration and could therefore have an impact on indication for hip preserving surgery.

The incidence and pattern of iliopsoas tendinitis following hip arthroscopy

Background: 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: 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: Of 258 hip arthroscopy cases, 18 cases (7.0%) of postoperative iliopsoas tendinitis were diagnosed under high resolution ultrasound. On average, iliopsoas tendinitis was diagnosed 2.8 ± 1.8 months after surgery. There were no significant differences in age, sex, and BMI between patients that developed IP tendinitis compared to those that did not. No specific procedures were found to be significantly associated with incidence of postoperative IP tendinitis, including capsular closure. 18 patients were treated with corticosteroid injection, which provided mild to moderate improvement for 5 (27.8%) patients and completely resolved symptoms for 13 patients (72.2%). Of all 18 patients with postoperative iliopsoas tendinitis confirmed by response to a diagnostic injection, 10 (55.6%) had symptoms improve within 3 months of diagnosis, 2 (11.1%) between 3 and 6 months, 4 (22.2%) between 6 and 12 months, and 2 (11.1%) after 1 year. No patients went on to have surgery for this problem. Patients with iliopsoas tendinitis had lower MHHS ( p = 0.04) and NAHS ( p = 0.09) scores at their 1-year postoperative visits. Conclusions: 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.

FEMOROACETABULAR IMPINGEMENT INSURANCE COVERAGE TRENDS IN RECENT YEARS: A COHORT BASED ANALYSIS

Background: The diagnostic criteria for surgical indication of femoroacetabular impingement (FAI) remain controversial. With a growing body of literature investigating the quality of these criteria, little is known about the direction that these have had on changes of third-party policies. The purpose of this study was to measure how these changes in policy would affect the exclusion of a cohort of previously identified FAI patients who were treated operatively. Methods: Four insurance companies’ coverage policies with specific criteria for the surgical treatment of FAI were applied to this population at two time points, 2012 and 2018, to determine whether these third-party payer criteria for FAI surgery were met. The insurance criteria were assessed in a prospective multicenter cohort of 712 patients undergoing primary FAI surgery. The policies listed various combinations of age, symptom duration, positive impingement test, radiographic osteoarthritis, radiographic sign of CAM and/or pincer impingement, and physical exam findings. Results: The cohort of 712 hips included 324 men [45.5%] and 388 females [54.5] with a mean age of 28.7 years. Overall, insurance criteria were not met in: Insurance #1 old 30.1%, new 25.7%; Insurance #2 old and new 17.8%, Insurance #3 old 21.9%, new 21.1%; and Insurance #4 old 17.8%, new 14.9%-20.6%. In 2012, the average percent exclusion of the four companies was 21.9%, this number decreased slightly to 20.6% overall in 2018. The most likely reason to be excluded was found to be failure to meet imaging criteria. The second most likely failed characteristic was a negative impingement test (65 patients excluded). Several insurance companies continue to utilize Outerbridge criteria for cartilage lesions which cannot be assessed preoperatively. Discussion and Conclusion: The diagnosis of FAI and its surgical indications have no definitive set criteria. Our study shows that with a six-year span of growing literature and updated policies, nearly 1 in 5 patients deemed to need surgical intervention by experienced hip preservation surgeons would still be denied coverage. There is a need for continued improvement of consensus regarding the diagnosis of FAI and appropriate indications for surgical intervention based on the available literature.