Abstract
Abstract
Introduction
The impact of a capsular sparing periportal approach on how partial and complete capsular repair impact stability of the hip is unknown. Therefore, our purpose was to determine how the capsulotomy affects native hip distractibility following the creation and repair of a periportal capsulotomy.
Methods
Nine cadaveric hemi-pelvises (7M, 2F) were included and mounted on an axial traction table. Fluoroscopic shots were taken at 12.5 pound (lbf) intervals from 0 up to 200 lbf in the following stages: (1) prior to any instrumentation or venting (native), (2) after the anterolateral (ALP) and mid-anterior portal (MAP) have been created (open), (3) after repair of the MAP only (partial), and (4) after closure of the ALP and MAP (complete). Joint space was calculated in millimeters using the shortest distance from the lateral edge of the sourcil to the femoral head. Comparisons were made via paired T-tests and Bonferroni corrected p-values were used to account for multiple comparisons.
Results
No differences in joint space at 0 lbf between the various capsular states and the native state were appreciated. The open capsule joint space was significantly larger at 50 (12.1 ± 3.32 mm vs 8.09 ± 3.14 mm; P=0.002), 100 (13.7 ± 2.80 vs 11.1 ± 2.70; P=<0.001), and 200 lbf (15.2 ± 2.76 vs 13.3 ± 2.65; P=<0.001) compared to the native capsule at the same traction intervals. At 100 lbf, there was significantly greater joint space in the partial versus native capsular state (12.5 ± 2.48 vs 11.1 ± 2.70; P=0.004), however, no difference was appreciated between native and partial closure at 50 or 200 lbf. Additionally, no differences were appreciated in joint space at 50 (8.09 ± 3.14 vs 9.96 ± 3.36; p=0.037), 100 (11.1 ± 2.70 vs 11.8 ± 2.79; P=0.045), and 200 lbf (13.3 ± 2.65 vs 13.5 ± 2.74; P=0.474) when both portals were closed compared to the native capsular state.
Conclusions
Closure of both the ALP and MAP best approximates resistance to axial traction seen in the native capsular state when compared to an open and single portal closure approach at low and high distractive forces.