The hip joint capsule is an important stabilising structure of the joint. The iliofemoral ligament in particular provides considerable stability. At hip arthroscopy, entry into the joint requires a capsulotomy, that is, an iatrogenic division of the capsule. How this iatrogenic tear is managed depends on many factors, including individual anatomical characteristics, one of which is the thickness of the joint capsule.
A new study examined the possible correlation between the femoral neck-shaft angle, measured on CT, and the thickness of the anterior capsule. In this retrospective study, hips were collected from patients who had undergone hip arthroscopy, aged 15 to 55 years. The femoral neck-shaft angle was measured on CT, and the thickness of the anterior capsule on MRI. The results were then analysed statistically, and other parameters were assessed in parallel, such as age, sex, body mass index, the lateral center-edge angle, the alpha angle, the Beighton Score and the femoral neck-shaft angle.
In total, data from 150 patients were included, with a mean age of 35.8 ± 11.2 years, and 56.7% were women.
The researchers confirmed that the femoral neck-shaft angle can predict the thickness of the anterior joint capsule, and indeed found that a reduction of 1° in the femoral neck-shaft angle increases the thickness of the joint capsule by 0.24mm.
Source: “Knee Surgery Sports Traumatology, Arthroscopy”, July 2023