Quantitative evaluation of capsular and labral resistances in the hip joint using a probing device

BACKGROUND: Probing to assess conditions of hip capsule and acetabular labrum is performed by "surgeons' feeling". OBJECTIVE: We investigated the resistance of the labrum and the hip capsule quantitatively while they were pulled with a probing device. METHODS: With the probing device in which a strain gauge was embedded, ten fresh frozen specimens of the pelvis and proximal femur were measured in each three surgical steps, (1) closed, (2) open, (3) closured for the capsule, and (1) intact, (2) cut, (3) repaired for the labrum. RESULTS: The mean highest resistance levels for the capsule were 9.8 N at the closed capsule, 4.1 N at the open capsule, and 8.5 N at the closured capsule. The values at the three phases were statistically significant. The mean highest resistance levels for the hip labrum were 8.2 N at the labrum intact, 4.0 N at the labrum cut, and 7.9 N at the labrum repair. The values at the three phases were also statistically significant. CONCLUSIONS: Since the quantitatively measured values in each three steps were significantly different, the values with the probing device might be useful to evaluate whether the lesion of the soft tissue exists and whether some surgical intervention works well.