Femoroacetabular impingement

Arthroscopic Repair of Acetabular Cartilage Delamination Using Chondral Nail Fixation in Patients With Femoroacetabular Impingement

Acetabular cartilage delamination is commonly seen in patients with femoroacetabular impingement (FAI), especially ones with the cam deformity. However, the definition and classification of acetabular cartilage injuries caused by FAI to guide clinical treatment remain controversial. Moreover, treatment of acetabular cartilage damage always causes a dilemma for surgeon during surgery. We believe a reliable repair of the acetabular cartilage delamination will lead to a better long-term outcome for patients with FAI. In this Technical Note, we introduce the chondral nail fixation under hip arthroscopy for treating acetabular cartilage delamination in patients with FAI. This technique contributes to eliminating intra-articular unstable factors, preserving native cartilage as much as possible, and restoring cartilage surface intact at best.

Retroversion of the hemipelvis rather than hypoplastic posterior wall decreases acetabular anteversion in hips affected by Perthes disease

The acetabular retroversion has a moderate incidence of 31-60% in all patients of the Perthes disease. It might be caused by posterior wall dysplasia based on recent animal researches. However, some studies support that hemipelvic retroversion is the main factor for the acetabular retroversion. The primary pathological factor of increasing retroversion angle is still controversial anatomically. This study aimed to identify whether there is acetabular retroversion in children with Perthes disease,and to find a method to distinguish version types. Forty children with unilateral Perthes disease who were admitted to our hospital from January 1, 2012 to December 31, 2018 were enrolled, and 40 controls were matched based on sex and age. The acetabular anteversion angle (AAA), internal wall anteversion angle (IWAA), anterior wall height of the acetabulum (A), acetabular posterior wall height (P), and acetabular width (W) were assessed on computed tomography (CT) at the level of the femoral head center. The acetabular wall difference index (AWDI; AWDI = P-A)/W*100) was calculated. The mean AAA was significantly lower in Perthes disease hips (10.59 (8.05-12.46)) than in contralateral hips (12.04 (9.02-13.33)) (p = 0.002) but did not differ from control hips (9.68 ± 3.76) (p = 0.465). The mean IWAA was significantly lower in Perthes hips (9.16 ± 3.89) than in contralateral hips (11.31 ± 4.04) (p = 0.000) but did not differ from control hips (9.43 ± 3.82) (p = 0.753). The mean AWDI did not differ between Perthes hips (0.41 ± 4.94) and contralateral hips (- 1.12 (- 4.50, 2.17)) (p = 0.06) or control hips (- 0.49 ± 5.46) (p = 0.437). The mean W was significantly higher in Perthes hips (44.61 ± 5.06) than in contralateral hips (43.36 ± 4.38) (p = 0.000) but did not differ from control hips (45.02 ± 5.01) (p = 0.719). The mean A and P did not differ between Perthes hips and contralateral hips or control hips. Correlation analysis of all hip joints revealed a significant correlation between AAAs and IWAAs (r = 0.772; r = 0.643; r = 0.608; and r = 0.540). Linear regression analysis revealed that AAAs increased with IWAAs. Multiple linear regression showed that IWAAs and AWDIs have good predictive value for AAAs in both Perthes and control hips (R² = 0.842, R² = 0.869). In patients with unilateral Perthes disease, the affected acetabulum is more retroverted than that on the contralateral side, which may be caused by hemipelvic retroversion. The measurements in this study could distinguish the form of acetabular retroversion. IWAAs and AWDIs can be used as new observations in future studies of acetabular version.

Prevalence of Radiographic Signs of Femoroacetabular Impingement in Asymptomatic Patients and Non-Athletes

Objective

Femoroacetabular impingement has been described as an anatomical variation of the proximal femur and/or acetabular rim, impinging the hip joint. A portion of the population asymptomatic in the hip may present radiographic changes from femoroacetabular impingement. The aim of the present study was to evaluate the prevalence of these signs in asymptomatic and sedentary males.

Methods

This was a clinical, observational, primary, cross-sectional, controlled study. A total of 32 male volunteers aged between 18 and 40 years, asymptomatic in the hip and sedentary, were selected from a university hospital orthopedic emergency room. All patients underwent standard anteroposterior pelvic radiographs. The measurements of the alpha angle, the retroversion index, the ischial spine signal, and the posterior wall sign were analyzed.

Results

The mean age was 29 years (18-40 years old). The prevalence of radiographic signs of femoroacetabular impingement using an alpha angle of 67 ^o was of 53.1%; with an alpha angle of 82 ^o , it was of 31.2%. The mean alpha angle was 67 ^o (52.4-88.2 ^o ), with 35.9% of the hips classified as borderline and 6.3% as pathological. The mean alpha angle for the right side was 67.5 ^o (52.5-88.2 ^o ), and, for the left, it was 66.6 ^o (53.1-86.9 ^o ). The mean retroversion index was 0.048 (right side: 0.044; left side: 0.052). The spine signal was positive in 15.6%, and the posterior wall sign, in 20.3% of the cases.

Conclusion

This study showed that the prevalence of radiographic signs in a population of asymptomatic and sedentary adult men was high (31.2%). New studies are required to explian the actual clinical significance of this finding.