External rotation strength deficit after hip resurfacing surgery

Surgical injury and repair of hip external rotators in THA via posterior approach: a three-dimensional MRI-evident quantitative prospective study

BACKGROUND

As one of the classical total hip arthroplasty (THA) approaches, the posterior approach is widely used. However, there is a lack of in-depth quantitative researches on the surgical-related injury to the hip external rotators. The purpose of this study is to quantificationally analyse the surgical injury of hip external rotators after posterior THA and explore the effect of the muscle repair on the muscle recovery using the MRI three-dimensional reconstruction technique combined with the clinical assessment.

METHODS

Sixty five patients were eligible to receive a unilateral cementless THA via the posterior approach. During operation, the piriformis tendon was reattached but it was not applicable for the internal obturator muscle. We performed three-dimensional MRI reconstruction of bilateral piriformis and internal obturator muscle along with clinical assessment preoperatively, 6, 12 and 52 weeks postoperatively.

RESULTS

Bilateral piriformis and internal obturator muscle were homogeneous preoperatively. Compared with the contralateral side, the volume atrophy and fat-muscle ratio of the piriformis on the operated side increased inconspicuously by 1.64%, 0.26% (p = 0.062, p = 0.071) at 6 weeks and 1.33%, 0.20% (p = 0.057, p = 0.058) at 12 weeks, while 7.28%, 2.09% and 15.71%, 5.14% for the internal obturator muscle (p < 0.01). Up to 52 weeks, the pirformis also showed significant muscle atrophy as well as fatty infiltration (increased by 7.79%, 4.21%; p < 0.01), and 24.18%, 11.91% for the internal obturator muscle (p < 0.01).

CONCLUSION

The THA via posterior approach significantly harms the hip external rotators and the early hip external rotation function. The effective repair could be conducive to the early postoperative recovery of the hip external rotators.

TRAIL REGISTRATION

The study has been registered in Chinese Clinical Trial Registry (ChiCTR) before the clical trial started, the Clinical Trial Registry Number is ChiCTR-IOR-17013007 . Registered 17 October 2017. The Trial registration is prospective registration.

Similar improvement in gait parameters following direct anterior & posterior approach total hip arthroplasty

We compared gait parameters prior to, at 6 months and 1 year following total hip arthroplasty (THA) performed via direct anterior approach (DAA) and posterior approach (PA) by a single surgeon in 22 patients. A gait analysis system involving reflective markers, infrared cameras and a multicomponent force plate was utilized. Postoperatively, the study cohort demonstrated improvement in flexion/extension range of motion (ROM) (P = 0.001), peak flexion (P = 0.005) and extension (P = 0.002) moments with no differences between groups. Internal/external ROM improved significantly in the DAA group (P = 0.04) with no change in the PA group. THA performed via DAA and PA offers similar improvement in gait parameters with the exception of internal/external ROM which might be related to the release and repair of external rotators during PA THA.

Outcomes of hip resurfacing in a professional dancer: a case report

A new surgical option (hip resurfacing arthroplasty) is now available for younger patients with hip osteoarthritis. A more aggressive rehabilitation program than the typical total hip arthroplasty protocol is needed for active individuals. This case report describes interventions used to maximize function in a 46-year-old professional dancer after hip resurfacing with a progressive therapeutic exercise program. Exercise choices were selected to address dance-specific requirements while respecting healing of the posterior capsular incision. Strengthening focused on hip abduction, extension, and external rotation. Precautions included avoiding gluteal stretching until 6 months. Pelvic alignment and weight-bearing distribution were emphasized. The patient was able to return to rehearsal by 7 months, at which time strength was equivalent to the unaffected leg. Range of motion reached unaffected side values at week 8 for internal rotation, week 11 for extension, week 13 for adduction, and week 28 for flexion. External rotation and abduction were still limited at 1 year, which influenced pelvic alignment with resultant pain on the unaffected side. Functional and impairment outcomes are presented with timelines to provide a basis for postoperative benchmarks for active clients after hip resurfacing. Although this case report presents a dance-specific program, exercise progressions for other active individuals may benefit from similar exercise intensity and sports-specific focus. Future rehabilitation programs should take into account possible flexion and external rotation range limitations and the need for gluteal muscle strengthening along with symmetry and pelvic alignment correction. Long-term studies investigating intensity of rehabilitation are warranted for patients intending to participate in higher level athletic activity.