The influence of soft tissue release on the tension around hip joint through posterolateral hip approach / 中华骨科杂志

ABSTRACT

ObjectiveTo investigate the influence of selective soft tissue release on the tension around hip joint through posterolateral approach, and to ascertain the sequence of soft tissue release in total hip arthroplasty. MethodsFive fresh frozen cadavers with ten intact lower extremities were used in the study. All the pelves of cadavers were fixed on the operating table by a special designed fixer on a lateral position. Femoral supracondylar bone traction was employed for axial traction. The force for traction was 15 kg. Posterolateral approach was used for exposure and two sequences for soft tissue release were studied. One Kirschner wire was fixed at the bone near the anterior superior iliac spine, and the wire was perpendicu-lar to the operating table. Another Kirschner wire was fixed into the bone at lateral femoral shaft. The two Kirschner wires were parallel to each other. The distance between the two Kirschner wires was measured be-fore and after each soft tissue structure release. ResultsThere were no significant changes of the distance measured before and after applying traction alone, releasing external rotation muscles, opening the posterior capsule and releasing the gluteus maximus insertion. There were significant changes of distance measured before and after resection of femoral head, release of tensor fasciae latae and/or iliotibial band, excision of anterior capsule, and release of iliopsoas tendon had. The average lengthened distance was 1.5 mm (range, 1-3 mm) after resection of femoral head, and 8.0 mm (range, 2-19 mm) after release of tensor fasciae latae and/or iliotibial band, 5.5 mm (range, 1-13 mm) after excision of anterior capsule, and 1.8 mm (range, 1-3 mm) after release of iliopsoas tendon respectively. The distance lengthened after both release of tensor fasci-ae latae (and/or iliotibial band) and excision of anterior capsule was the most significant, average 13.5 mm (range, 11-20 mm). ConclusionRelease of anterior capsule, tensor fasciae latae and/or iliotibial band, and iliopsoas tendon will decrease the soft tissue tension around hip joint. Among all the soft tissue structures we investigated, the anterior capsule and tensor fasciae latae (iliotibial band) make the most effective result. To maintain the soft tissue tension around hip joint depends on different structures working together, releasing one structure alone may not obtain the optimal result. Careful evaluation of tension of tensor fasciae latae and iliotibial band can help avoiding the limb length discrepancy during hip arthroplasty surgery.