Minimal Influence on Muscle Strength and Patient Reported Outcome Measures by Conjoined Tendon Detachment in Anterolateral Muscle-Sparing Total Hip Arthroplasty

Hidetatsu Tanaka; Norikazu Yamada; Hiroaki Kurishima; Yu Mori; Toshimi Aizawa

doi:10.1007/s43465-023-01080-5

Minimal Influence on Muscle Strength and Patient Reported Outcome Measures by Conjoined Tendon Detachment in Anterolateral Muscle-Sparing Total Hip Arthroplasty

Indian J Orthop. 2024 Jan 5;58(2):127-134. doi: 10.1007/s43465-023-01080-5. eCollection 2024 Feb.

Authors

Hidetatsu Tanaka^{1

2}, Norikazu Yamada², Hiroaki Kurishima², Yu Mori¹, Toshimi Aizawa¹

Affiliations

¹ Department of Orthopaedic Surgery, Tohoku University Graduate School of Medicine, 1-1 Seiryo-Machi, Aoba-ku, Sendai, 980-8574 Japan.
² Department of Orthopaedic Surgery, Japanese Recross Sendai Hospital, 43-3, 2 Cho-me, Yagiyama Hon-cho, Taihaku-ku, Sendai, 982-8501 Japan.

Abstract

Purpose: The conjoined external rotator tendon (CERT), composed of the tendons of the gemellus superior, obturator internus (OI), and gemellus inferior muscles, stabilizes the hip joint. The study investigates the clinical and radiological effects of the CERT release during anterolateral-supine approach (ALSA) total hip arthroplasty (THA).

Methods: A cohort of 60 patients who underwent ALSA THA was examined. Pre- and post-operative muscle width, muscle strength, and radiological data were compared between the CERT-detached and preserved groups. In addition, Clinical assessments were performed using the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire and the short-form 36 questionnaires.

Results: 58.3% had CERT detached, resulting in radiological atrophy of the OI muscle. Despite this, hip flexion, extension, and abduction muscle strength significantly improved at 6 months post-surgery. The detached CERT did not substantially affect patient-reported outcome measures, including pain and daily activities, within the 6-month follow-up.

Discussion: The study suggests that while CERT detachment can lead to muscle atrophy, it has a limited impact on muscle strength and patient-reported outcome measures, indicating the muscle's potential redundancy. Preserving the CERT might enhance stability and prevent atrophy but could increase the risk of complications. CERT release is recommended when femur exposure is inadequate.

Keywords: Anterolateral-supine approach; Biodex system; Conjoined external rotator tendon; Minimum invasive surgery; Muscle atrophy; Muscle strength; Obturator internus; Osteoarthritis of the hip; Patient-reported outcome measures; Total hip arthroplasty.

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