This study is a randomized controlled trial designed to evaluate the impact of considering spinopelvic mobility during preoperative planning on functional outcomes in patients with chronic low back pain who undergo total hip arthroplasty. Adult patients (aged 18 and above) with hip osteoarthritis and chronic low back ache will be recruited, subject to inclusion and exclusion criteria. After randomization, the intervention group will undergo a detailed spinopelvic assessment—both clinical and radiological—including standing and sitting spine-pelvis radiographs to measure pelvic incidence, pelvic tilt, sacral slope, and lumbar flexibility. Conventional preoperative assessment without targeted spinopelvic evaluation will be done in the control group. Surgery will follow standardized protocols, with implant positioning based on spinopelvic parameters in the intervention group and conventional alignment in controls. Outcomes including the Harris Hip Score, SF-36 for back pain, radiological cup placement parameters, and gait analysis will be assessed at baseline, 6 weeks, 3 months, and 6 months postoperatively. The study will be conducted at the Department of Orthopaedics, Jawaharlal Nehru Medical College & Acharya Vinoba Bhave Rural Hospital, Wardha, from October 2025 onwards, enrolling a minimum of 26 patients. Ethical approval has been obtained from the Institutional Ethics Committee, and informed consent will be secured from all participants.