Hip Stability May Influence the Development of Greater Trochanteric Pain Syndrome: A Case-Control Study of Consecutive Patients

Background: Greater trochanteric pain syndrome (GTPS) is thought to relate primarily to tendinosis/tendinopathy of the hip abductors. Previous studies have suggested that certain anatomic factors may predispose one to development of the condition. Hypothesis: It was hypothesized that intrinsic acetabular bony stability of the hip is related to the development of GTPS. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 198 consecutive patients diagnosed with GTPS were compared with 198 consecutive patients without clinical evidence of GTPS. Electronic health records of the included patients were examined; data recorded included patient age, sex, race, and body mass index (BMI). Standing anteroposterior radiographs were evaluated by 2 blinded examiners who measured the Tönnis angle, lateral center-edge angle (LCEA), and acetabular depth/width ratio (ADW) and assessed for the presence of a posterior wall sign. The number of dysplastic measures was recorded for each patient based on published norms. Associations between radiographic and patient variables versus the presence or absence of GTPS were determined. Factors with univariate associations where P < .20 were included in a binary logistic regression model to identify independent predictors of the presence of GTPS. Results: There was no difference between groups in terms of age, BMI, or race. There were significantly more women than men in the GTPS group (71% vs 30%; P < .001). Intraclass correlation coefficients were good for the LCEA (0.82) and Tönnis angle (0.82) and poor (0.08) for the ADW. Kappa was moderate for the presence of a posterior wall sign (0.51). An increased Tönnis angle, decreased ADW, and ADW <0.25 were significantly associated with the presence of GTPS. The binary logistic regression model identified an increased Tönnis angle ( P < .010) and female sex ( P < .001) as independent risk factors for GTPS. Conclusion: Based on this preliminary retrospective study, decreased intrinsic acetabular bony stability of the hip may be associated with an increased risk of GTPS.

The Ischial Spine in Developmental Hip Dysplasia: Unraveling the Role of Acetabular Retroversion in Periacetabular Osteotomy

Purpose. Radiological diagnosis of acetabular retroversion (AR) is based on the presence of the crossover sign (COS), the posterior wall sign (PWS), and the prominence of the ischial spine sign (PRISS). The primary purpose of the study is to analyze the clinical significance of the PRISS in a sample of dysplastic hips requiring periacetabular osteotomy (PAO) and evaluate retroversion in symptomatic hip dysplasia. Methods. In a previous paper, we reported the classic coxometric measurements of 178 patients with symptomatic hip dysplasia undergoing PAO where retroversion was noted in 42% of the cases and was not found to be a major factor in the appearance of symptoms. In the current study, we have added the retroversion signs PRISS and PWS to our analysis. Among the retroverted dysplastic hips, we studied the association of the PRISS with the hips requiring PAO. We also defined the ischial spine index (ISI) and studied its relationship to the coxometric measurements and AR. Results. In hips with AR, the operated hips were significantly associated with the PRISS compared to the nonoperated ones (χ2 = 4.847). Additionally, the ISI was able to classify acetabular version (anteverted, neutral, and retroverted acetabula). A direct correlation between the ISI and the retroversion index (RI) was found, and the highest degree of retroversion was found when the 3 signs of acetabular retroversion were concomitantly present (RI = 33.6%). Conclusion. The PRISS, a radiographic sign reflecting AR, was found to be significantly associated with dysplastic hips requiring PAO where AR was previously not considered a factor in the manifestation of symptoms and subsequent requirement for surgery. Moreover, the PRISS can also serve as an adequate radiographic sign for estimating acetabular version on pelvic radiographs.

DIFFERENCES IN RADIOGRAPHIC MEASUREMENTS ON STANDING VERSUS SUPINE PELVIC RADIOGRAPHS

Background: Accurate pelvic radiographic measurements is of clear clinical importance, as these measurements can drive the indications for surgery, the surgical approach utilized, and/or the degree of correction during hip preservation surgery. Currently, there are a large number of measurements available and reported on the literature when referencing anterior-posterior (AP) pelvic radiographs. However, there is no standardization of whether these pelvic radiographs are obtained in the standing or supine position. Hypothesis/Purpose: Standing vs. Supine radiographs, obtained in the same patient, will result in different value for standard radiographic measurements used in making hip pathology diagnoses. Methods: All new patients who presented for evaluation of hip pain between September 2016 and July 2018 were retrospectively reviewed. Inclusion criteria included age 18-50, no prior hip surgery/injury, and both standing and supine AP pelvis radiographs dated within 2 years of each other. Measurements were obtained on 26 radiographs (52 hips), blinded to patient demographics and standing versus supine radiograph. Measurements included minimum joint space, lateral center edge angle (LCEA), acetabular depth, acetabular inclination, Tönnis Grade, crossover sign, posterior wall sign, ischial spine sign. Results: Standing films resulted in significantly lower LCEA and acetabular depth measurements, and higher acetabular inclination. Supine measurements for crossover sign were 5.69 times more likely to be positive than standing measurements. Similarly, supine measurements for ischial spine were 7.93 times more likely to be positive (see Table 1). Conclusion: Based on our study, supine films are almost 6 times more likely to give a positive crossover sign and almost 8 times more likely to give a positive ischial spine sign than a standing film in the same patient. Additionally, LCEA, acetabular depth will be lower and acetabular inclination will be higher on standing films. As such, our recommendation is to obtain standing AP pelvis radiographs to obtain the most accurate pelvic radiographic measurements in hip preservation patients. Tables: [Table: see text]

Radiographic Hip Anatomy Correlates With Range of Motion and Symptoms in National Hockey League Players

Background: Hip disorders in athletes have been increasingly recognized. Purpose: To characterize radiographic hip anatomy for National Hockey League (NHL) players and correlate it with hip range of motion and hip symptoms and/or surgery. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Fifty-nine professional hockey players (118 hips) with 1 NHL organization (mean age, 24.2 years; range, 18-36) prospectively underwent history and physician examination by 2 independent orthopaedic surgeons. Current or previous groin and/or hip pain or surgery was noted. Anteroposterior (AP) pelvis and bilateral Dunn lateral radiographs were obtained for all players with assessment of hip morphology by 2 blinded independent orthopaedic surgeons. Results: Good to very good reliability of radiographic assessments was noted (intraclass correlation coefficients = 0.749-0.958). Sixty-four percent of athletes had a positive crossover sign, while 86% and 60% had a positive posterior wall sign and a prominent ischial spine sign, respectively. Twenty-one percent of hips demonstrated dysplastic acetabular features (lateral center edge angle <25°). Eighty-five percent and 89% of hips demonstrated cam-type morphology based on alpha angle (>50° Dunn lateral) and head-neck offset, respectively. Good to very good reliability was noted for ROM assessments (intraclass correlation coefficient >0.69). Mean hip flexion was 107.4º ± 6.7º, and mean hip internal rotation was 26.1º ± 6.6º. Thirty-one percent of hips had a history of hip-related pain and/or surgery. Higher AP, Dunn lateral, and maximal alpha angles correlated with decreased hip internal rotation ( P = .004). Greater AP alpha angle correlated with decreased hip extension/abduction ( P = .025), and greater Dunn lateral and maximal alpha angle correlated with decreased hip flexion/abduction ( P = .001). A positive posterior wall sign correlated with increased straight hip abduction, while other radiographic acetabular parameters were not predictive of range of motion. Only decreased hip external rotation and total arc of motion correlated with an increased risk for current or prior hip symptoms or surgery ( P < .001). Conclusion: Hip anatomy in NHL players is characterized by highly prevalent cam-type morphology (>85%) and acetabular retroversion (>60%). In addition, acetabular dysplasia (21%) was relatively common. Greater cam-type morphology correlated with decreased hip range of motion, and a positive crossover sign correlated with increased hip abduction. Decreased hip external rotation and total arc of motion were predictive of hip-related pain and/or surgery.

Treatment Algorithm for Patients with Non-arthritic Hip Pain, Suspect for an Intraarticular Pathology

Background: The amount of patients referred with longstanding, non-arthritic hip pain is increasing, as are the treatment options. Left untreated hip dysplasia, acetabular retroversion and femoroacetabular impingement (FAI) may lead to osteoarthritis (OA). Finding the right treatment option for the right patient can be challenging in patients with non-arthritic hip pain. Purpose: The purpose of this study was to categorize the radiographic findings seen in patients with longstanding hip pain, suspect for an intraarticular pathology, and provide a treatment algorithm allocating a specific treatment option for each clinical condition. Material and Methods: A review of the literature was performed using Public Medline searches of MeSH terms combined with synonyms for femoroacetabular impingement, acetabular retroversion, periacetabular osteotomy and hip arthroscopy. Results: Radiographic findings associated with acetabular retroversion described in the literature were the crossover sign, the posterior wall sign and the ischial spine sign, while Wiberg’s lateral center-edge angle (CE-angle) together with Leqeusne’s acetabular index indicate hip dysplasia. A Tönnis index >2 indicates osteoarthritis, however unsatisfying results are documented following joint preserving surgery with a Tönnis index >1. Furthermore, ischial spine sign in combination with the posterior wall sign indicates total acetabular retroversion prone to periacetabular osteotomy in contrast to focal retroversion prone to hip arthroscopy. These findings were used creating a treatment algorithm for intraarticular pathologies in patients with longstanding hip pain. Conclusion: Based on the radiographic findings, the algorithm presented in this study can be a helpful tool in the decision-making for the treatment of patients with non-arthritic hip pain, suspect for intraarticular pathologies.