Endoscopic Tendon Release for Iliopsoas Impingement After Total Hip Arthroplasty-Excellent Clinical Outcomes and Low Failure Rates at Short-Term Follow-Up.

PURPOSE: To investigate the clinical effectiveness of endoscopic iliopsoas tendon release (IPR) at the lesser trochanter (LT) in patients with iliopsoas impingement (IPI) after total hip arthroplasty (THA). METHODS: Between November 2017 and March 2021, a consecutive series of 36 patients were treated with endoscopic IPR for diagnosed IPI. Patients included had acetabular cup position confirmed by functional imaging (OPS, Corin, Pymble, NSW), typical clinical symptoms of IPI, and a positive response to diagnostic injection. Clinical assessment included validated patient-reported outcome measures (PROMs) along with hip flexion strength and active range of motion at different time marks up to 2-year follow-up, as well as surgical complications. RESULTS: Overall, 36 consecutive patients (11 males) with a mean age of 62 ± 12 years were included. All patients had failed nonoperative management. Dynamic computed tomography assessment was available in 89% of the patients, edge loading was reported in 10%, and variable cup overhang was reported in 50%. Clinically, PROMs were significantly improved at every time mark when compared with preoperative values (P < .001), showing the biggest improvement within the first 4 weeks after surgery. At the 6-month follow-up, peak isometric hip flexion strength on the operated side was 20% lower than the contralateral side (P < .001). Failure rate of the procedure was 2.8% (1 case). Linear regression showed no association between cup overhang and clinical outcomes. CONCLUSIONS: Endoscopic IPR at the LT is a safe and reproducible technique associated with significant and immediate improvement in pain, functional outcomes, and high patient satisfaction. With minimal short-term weakness, no complications, and only a single revision, even in cases with cup malposition and/or edge loading, we believe that endoscopic IPR can be considered as one of the first-line operative options in patients with symptomatic IPI, irrespective of component position. LEVEL OF EVIDENCE: Level IV, case series.

Functional assessment of component positioning in patients with groin pain after total hip arthroplasty as a tool to guide management.

BACKGROUND: Persisting groin pain post total hip arthroplasty (THA) is a common and complex issue that can be difficult to diagnose and manage. Acetabular component positioning is often implicated. AIMS AND METHODS: We used a previously well described and validated functional positioning protocol to determine if functional acetabular malpositioning was a factor in groin pain post THA and hence to determine if acetabular revision would be indicated. We compared patient-specific functional acetabular positioning to traditional CT evaluation of cup position and assessment of anterior cup overhang. RESULTS: 39 patients with groin pain post-THA were investigated. Functional acetabular malpositioning was diagnosed in 31% (12/39). Revision THA was performed in those 12 patients, resulting in resolution of functional malpositioning (100%), with an overall accuracy of 5.6° (range 1-12), and resolution of groin pain in 67% (8/12). 33% (4/12) of the revised implants had functional positioning located outside the traditional "40/20 zone". Comparison with CT indicated that 40% (4/10) of implants with anterior overhang were well positioned, however only 50% (6/12) of functionally malpositioned implants had CT evidence of anterior cup prominence. Of the 8/12 revision patients who had resolution of their groin pain, only 1 had cup prominence. CONCLUSIONS: This study suggests that the utilisation of a patient specific functional positioning algorithm in the analysis of persistent groin pain following THA can assist in identifying the underlying cause of pain and help to guide treatment. For a functionally malpositioned acetabulum, revision surgery offers a potential resolution of groin pain.

Functional navigation in hip resurfacing.

BACKGROUND: Acetabular malpositioning in total hip arthroplasty (THA) can result in edge loading, leading to increased wear, pseudotumours and bearing failure. Historically Lewinnek's safe zone has been the goal for optimal THA cup positioning; however, research indicates that one generic safe zone is not ideal. In hip resurfacing (HR) there is a lack of data regarding optimal position, and studies indicate that edge loading is related to increased inclination. METHODS: We used a functional positioning protocol to produce patient-specific (PS) dynamic analyses, identifying individual functional ideal acetabular zones. We hypothesized that identifying and implanting into PS functional ideal zones would result in decreased edge loading and improved clinical outcomes. Fifteen adept HRs were implanted using a PS functional positioning protocol. As plans were created for standard THA acetabular position, adjustments were made intra-operatively. RESULTS: Dynamic post-operative analyses showed 80% of implants were appropriately positioned. The remaining 20% had edge loading, where implants had inclination ≤5° of planned positioning and 10° of planned anteversion. 60% were ≤10° of planned inclination and anteversion. No pre-operative planned positions were within 'Lewinneks's zone', indicating its questionable relevance, especially in HR. A total of 20% of patients developed pain; however, at 1 year post-operatively all patients recorded improved Oxford hip scores. CONCLUSION: This study confirms that functional positioning in HR consistently results in improved precision and accuracy in achieving the functional acetabular ideal zone, leading to improved clinical outcomes and prevention of edge loading.