Gluteal Sling Release on Gluteal Dysfunction After in Primary Total Hip Arthroplasty

Not Applicable

Completed

• Conditions: Hip Osteoarthritis; Osteoarthritis, Hip; Gluteus Maximus Muscle Atrophy; Muscle Weakness Condition; Fatty Degeneration

• Registration Number: NCT06850155
• Lead Sponsor: Ankara City Hospital Bilkent

Brief Summary

This study investigates the effects of gluteal sling release during total hip arthroplasty (THA) on gluteal muscle function and hip joint performance. The gluteal sling release technique is used to improve surgical visualization and reduce the risk of sciatic nerve compression, but its impact on postoperative muscle function remains unclear. A prospective randomized controlled trial was conducted on 144 patients with unilateral coxarthrosis undergoing THA, divided into three groups: gluteal sling preserved, released, and released with repair. Clinical outcomes were assessed preoperatively and at six months postoperatively using VAS, HHS, and WOMAC scores, alongside hip CT scans and isokinetic strength testing. While all groups showed significant functional improvement, muscle density in the released gluteal sling group decreased significantly, suggesting potential fatty degeneration. However, no significant differences were found in gluteus maximus surface area or hip extensor strength between the groups. The findings suggest that while gluteal sling release enhances intraoperative visualization and may reduce sciatic nerve injury risk, it could contribute to muscle degeneration. Therefore, preserving or repairing the sling when possible and implementing structured rehabilitation may optimize postoperative outcomes.

Detailed Description

This study aimed to assess the impact of gluteal sling release during total hip arthroplasty (THA) on gluteal muscle function and hip joint outcomes. A prospective randomized controlled trial was conducted between September 2023 and August 2024, including 144 patients diagnosed with unilateral coxarthrosis who underwent THA. Patients were divided into three groups: gluteal sling preserved (n=47), released (n=52), and released and repaired (n=45). Preoperative and postoperative evaluations at six months included clinical scoring (VAS, HHS, and WOMAC), hip computed tomography (CT) scans for muscle cross-sectional area and density, and isokinetic testing to measure hip extensor strength. Surgical and rehabilitative procedures were standardized across all groups, with a focus on evaluating the functional and radiological effects of gluteal sling release.

The results demonstrated that all groups experienced significant postoperative improvements in pain scores (VAS), hip function (HHS), and joint-related disability (WOMAC) (p\<0.001). No significant differences were observed between the groups in terms of gluteus maximus muscle cross-sectional area (p\>0.05). However, muscle density significantly decreased in the gluteal sling release group (p=0.022), suggesting fatty degeneration, while no significant changes were observed in the other groups. Hip extensor strength showed a decline in the gluteal sling release group and an increase in the other groups, but these differences were not statistically significant (p\>0.05). Sciatic nerve injury was recorded in one patient (2.1%) from the preserved group but was absent in the other groups. No significant differences were found in sciatic nerve injury rates across the groups.

In conclusion, the gluteal sling release technique provides better intraoperative visualization and may reduce the risk of iatrogenic sciatic nerve injury by alleviating nerve compression. However, while it does not significantly affect hip extensor strength, it may contribute to muscle fatty degeneration. Given these findings, preserving or repairing the gluteal sling whenever feasible is recommended. Additionally, a well-structured rehabilitation program following surgery is crucial to optimize patient recovery and functional outcomes.

Study Timeline

• Study Start: 2023-09-01
• Primary Completion: 2024-08-01
• Status Verified: 2025-02
• Study Completion: 2025-02-04
• Study First Submitted: 2025-02-23
• Study First Submitted QC: 2025-02-23
• Last Update Submitted: 2025-02-26
• Study First Posted: 2025-02-27
• Last Update Posted: 2025-02-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 144

Inclusion Criteria

• Patients diagnosed with unilateral coxarthrosis
• Scheduled for primary total hip arthroplasty (THA)
• Age between 18 and 90 years

Exclusion Criteria

• Coxarthrosis secondary to:

  • Developmental hip dysplasia
  • Fracture-related pathology

• Conditions requiring revision surgery, including:

  • Periprosthetic fractures
  • Current or previous hip joint infections
  • Rotational or malalignment issues requiring revision

• Neuromuscular diseases

• History of prior hip surgeries, such as:

  • Hip arthroscopy
  • Core decompression

• Mobility-limiting conditions in the contralateral hip (e.g., osteoarthritis)

• Patients lost to follow-up or with incomplete data

• Patients who developed complications (e.g., infection, dislocation) within six months of follow-up

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Muscle atrophy	Preoperative & Postoperative 6th month	Muscle atrophy through cross-sectional area measurement on CT scans (number, cm\^2)
Muscle density	Preoperative & Postoperative 6th month	Muscle density measurements on CT scans (Hounsfield units - HU)
Kinematic assesment	Postoperative 6th month	Muscle strength through kinematic assesment (Nm)

Secondary Outcome Measures

Name	Time	Method
Visual Analog Scale (VAS)	Preoperative & Postoperative 6th month	minimum value:0, maximum value 10, higher values mean worse outcome
Harris Hip Score (HHS)	Preoperative & Postoperative 6th month	minimum value:0, maximum value 100, higher values mean better outcome
Western Ontario and McMaster Universities Arthritis Index (WOMAC)	Preoperative & Postoperative 6th month	minimum value:0, maximum value 100, higher values mean worse outcome

Trial Locations

Locations (1)

Ankara Bilkent City Hospital; 🇹🇷 Ankara, Turkey