A T-capsulotomy provides increased hip joint visualization compared with an extended interportal capsulotomy

Abstract

The purpose of this study was to compare the cross-sectional area (CSA) of joint visualization between extended interportal and T-capsulotomies. Twenty fresh-frozen cadaveric hips were dissected to their capsuloligamentous complexes and fixed in a custom apparatus in neutral hip position. Ten hips underwent sequential interportal capsulotomies at lengths of 2, 4, 6, and 8 cm. Ten hips underwent sequential T-capsulotomies starting from a 4 cm interportal capsulotomy, creating a 2 cm T-capsulotomy (Half-T), and finally a 4 cm T-capsulotomy (Full-T). Following each sequential capsule change in both groups, a high-resolution digital photograph was taken to measure the visualized intra-articular cross-sectional area (CSA). Independent t-test was used to compare CSA interportal and T-capsulotomy groups. Analysis demonstrated a statistically significant increase in CSA visualization with each sequential increase in interportal capsulotomy length up to 6 cm (2cm: 0.6 ± 0.2 cm2; 4cm: 2.1 ± 0.5 cm2 (p<0.001); 6cm: 3.6 ± 1.0 cm2 (p=0.001)), and no difference at 8cm (4.2 ± 1.2 cm2 (p=0.20)). For the T-capsulotomy group the average CSA visualization significantly increased from 3.2 ± 0.9 cm2 for the Half-T to 7.1 ± 1.0 cm2 for the Full-T (p<0.001). The Half-T CSA visualization was not statistically different from the 6 cm capsulotomy (p=0.4) and the 8cm capsulotomy (p=0.05). The Full-T had significantly superior CSA visualization area as compared to the 6 cm and 8 cm interportal capsulotomies (p<0.001 for both). In conclusion, T-capsulotomy resulted in improved cross-sectional area of joint visualization compared to an extended (8cm) interportal capsulotomy in a cadaveric model. Surgeons must weigh the benefits of greater visualization from T-capsulotomy that may help to avoid residual FAI while ensuring to completely repair the capsulotomy to avoid iatrogenic instability.