168260 20260130124312.0 doi 10.32598/RJ.25.4.3883.1 sideral 147758 ART-2025-147758 eng Gallego-Pen~alver, Francisco José Unilateral Psoas Muscle Atrophy as a Possible Risk Factor for Low Back Pain After Total Hip Arthroplasty: A Case Report 2025 Introduction The psoas muscle plays an essential role in the hip and lumbar spine. Total hip arthroplasty surgery can change the ipsilateral psoas muscle, which may affect lumbar biomechanics and accelerate disk degeneration. We present a clinical study that suggests a potential association between unilateral psoas muscle atrophy after hip replacement surgery and subsequent low back pain Case description A 53-year-old man with a history of right total hip arthroplasty for osteoarthritis presented with left lumbosciatalgia 6 years after surgery. In the physical examination, the patient exhibited weakness 2/5 in Kendall’s muscle grading system in the right hip flexion and left extensor hallucis longus and triceps surae. Magnetic resonance imaging revealed a degenerative disk L5-S1 and severe unilateral atrophy of the right psoas muscle. Conservative treatment through physiotherapy was initiated, but persistent pain ultimately necessitated microdiscectomy at the L5–S1 level. Conclusion Total hip arthroplasty surgery may lead to long-term unilateral atrophy of the ipsilateral psoas muscle and alter lumbar biomechanics, potentially accelerating the disk degeneration and subsequent low back pain. Investigating this possible correlation may offer greater clarity regarding low back pain after total hip arthroplasty. In our case, conservative treatment through 15 sessions of physical therapy resulted in very limited improvement, and advanced diskopathy required surgical intervention to decompress the affected lumbar root. Access copy available to the general public Unrestricted info:eu-repo/semantics/openAccess by-nc https://creativecommons.org/licenses/by-nc/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Cía-Blasco, Pedro Gómez-Trullén, Eva María Universidad de Zaragoza (orcid)0000-0002-7876-4735 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 25, 4 (2025), 890-905 Archives of Rehabilitation 2538-6247 2284467 http://zaguan.unizar.es/record/168260/files/texto_completo.pdf Versión publicada 1807309 http://zaguan.unizar.es/record/168260/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:168260 articulos driver 2026-01-30-12:20:59 ARTICLE