Hip Replacement — How It Works, Benefits & Recovery — Procedure Guide, Recovery & Risks | MyMedicPlus

Total hip arthroplasty (THA) is an orthopaedic surgical procedure that replaces a diseased or damaged hip joint — consisting of the femoral head (ball) and acetabulum (socket) — with precisely engineered prosthetic components that replicate normal hip anatomy and biomechanics. The implant system comprises a metallic stem inserted and fixed into the femoral canal, a ceramic or metal femoral head attached to the stem neck, and a metal-backed acetabular cup press-fit into the reamed acetabulum, lined with ultra-high-molecular-weight polyethylene (UHMWPE), ceramic, or metal articulating against the femoral head. Modern bearing couples include ceramic-on-ceramic and ceramic-on-polyethylene, which significantly reduce wear particle generation compared with metal-on-metal designs. Fixation is either cemented (acrylic bone cement locks the components), cementless (porous ingrowth surfaces allow bone ongrowth), or hybrid (cementless cup, cemented stem). THA is one of the most successful and cost-effective elective operations in medicine, transforming quality of life in patients disabled by end-stage hip arthritis. Over 1 million THA procedures are performed annually worldwide, with 100,000+ in the UK and over 400,000 in the United States.

This treatment represents an important component of modern medical management, supported by clinical evidence from multiple randomised controlled trials and systematic reviews. Treatment protocols are continually refined based on emerging evidence to optimise patient outcomes while minimising treatment burden.

Patient suitability is assessed through a structured multidisciplinary evaluation incorporating clinical history, physical examination findings, and results of relevant investigations. Treatment planning considers the full clinical context including disease characteristics, patient comorbidities, functional status, and individual treatment goals to ensure the most appropriate therapeutic approach is selected for each patient.

Hip replacement is indicated when hip joint disease causes persistent, severe pain and functional limitation that significantly impairs quality of life despite maximum non-operative management. The decision is based on symptoms and functional limitation rather than radiological findings or patient age. Primary indications include end-stage hip osteoarthritis (the most common cause — progressive destruction of articular cartilage), rheumatoid and inflammatory arthritis, avascular necrosis (osteonecrosis) of the femoral head from corticosteroid use, alcoholism, sickle cell disease, or idiopathic causes, post-traumatic arthritis following acetabular or femoral neck fractures, displaced femoral neck fractures in elderly patients (hemiarthroplasty or THA), ankylosing spondylitis, hip dysplasia causing premature arthritis, and Paget's disease affecting the hip joint. Surgery is considered when pain severely limits walking distance, disturbs sleep, prevents basic activities of daily living, and has not responded adequately to analgesics (NSAIDs, opioids), physiotherapy, weight loss, walking aids, and intra-articular corticosteroid injections over 3–6 months.

Under spinal (preferred for haemodynamic stability and reduced blood loss) or general anaesthesia, the patient is positioned lateral decubitus or supine (anterior approach). Standard surgical approaches include the posterior approach (most common globally, 80% of procedures — good acetabular exposure, slightly higher early dislocation risk without posterior capsule repair), the anterolateral (modified Hardinge — less dislocation risk but risk of abductor weakness), and the anterior approach (tissue-sparing, lower dislocation risk, faster rehabilitation but technically demanding). The hip is dislocated, the femoral head resected at the planned level, and the acetabulum reamed to the appropriate diameter. The acetabular cup is impacted into place at 45° inclination and 15° anteversion; screws may supplement fixation. The femoral canal is broached sequentially, and a trial stem and head of appropriate size inserted to assess leg length, offset, and stability. The final implant is then fixed. The joint is reduced, stability tested through full range, and fluoroscopic images confirm implant position. The wound is closed in layers and dressings applied. Robotic-assisted THA (MAKO system) improves cup positioning accuracy. Total operative time is 60–90 minutes in experienced hands.

The procedure is performed in an appropriately equipped facility by experienced specialist clinicians. Prior to commencement, the patient undergoes pre-procedural assessment including vital signs measurement, review of relevant investigations, and confirmation of informed consent. Intravenous access is established and monitoring equipment including ECG, pulse oximetry, and blood pressure monitoring is applied.

The procedural site is prepared according to aseptic technique standards. Anaesthesia or analgesia is administered as appropriate for the specific procedure and patient needs, ranging from local anaesthesia for minor procedures to regional or general anaesthesia for more complex interventions.

The procedure is performed under direct visualisation or image guidance as appropriate. Key technical steps are executed with attention to anatomical landmarks and patient safety parameters. Haemostasis is achieved and confirmed before completion. Post-procedural assessment includes clinical evaluation of the immediate result, complication surveillance, and documentation of the procedure.

Recovery room monitoring continues until the patient meets defined discharge criteria. Written post-procedural instructions covering activity restrictions, wound care, medication management, and symptoms requiring urgent review are provided before discharge.

Total hip arthroplasty achieves 90–95% implant survival at 10 years and approximately 80–85% at 20 years, based on national joint registry data from 30+ countries. Pain relief is dramatic — over 95% of patients report significant or complete pain relief. Most patients walk unaided within 6–12 weeks. Oxford Hip Score (OHS) and Harris Hip Score (HHS) improve by 20–30 points on average after THA. Patient satisfaction exceeds 90% at 1 year. Functional capacity improvements are sustained at 10-year follow-up in the majority of patients. Quality-adjusted life year (QALY) analysis demonstrates THA to be one of the most cost-effective interventions in healthcare, with a cost per QALY below that of dialysis, coronary artery bypass surgery, and many pharmaceutical treatments. Modern cementless stems show equivalent long-term outcomes to cemented fixation, with superior results in younger, more active patients. Computer-assisted and robotic THA improves implant positioning accuracy to within 1–2 degrees of the planned target, potentially reducing dislocation risk and wear rates.

DVT and pulmonary embolism are the most common serious early complications — prevented by extended anticoagulation with low-molecular-weight heparin or direct oral anticoagulants (rivaroxaban, apixaban) for 35 days post-operatively plus mechanical compression stockings. Prosthetic joint infection (PJI) occurs in 1–2% of primary THA, is among the most devastating complications, and may require two-stage revision surgery (implant removal, 6 weeks of antibiotic spacer, reimplantation). Risk factors include diabetes, obesity, immunosuppression, and prior wound problems. Dislocation occurs in 1–3% of primary THA (higher in the first 3 months); most reduce with closed manipulation under sedation. Leg length discrepancy of more than 10 mm is clinically significant and occurs in approximately 1–2%. Sciatic nerve injury (posterior approach) causes foot drop in under 1%; peroneal nerve injury is rare but a recognised complication. Aseptic loosening — implant–bone interface failure without infection — is the leading cause of late failure, occurring in 5–10% at 15–20 years, requiring revision THA. Periprosthetic fracture around the implant occurs in 0.5–1% of primary THA. Trunnion corrosion and adverse local tissue reactions (ALTR) are concerns with metal-on-metal implants.

Weight-bearing as tolerated with a walking frame begins within hours of surgery on the day of the procedure, facilitated by the enhanced recovery after surgery (ERAS) protocol. Hip precautions (no crossing legs, no bending hip beyond 90°, no internal rotation) are applied for 6–12 weeks for posterior approach surgery — anterior approach patients have fewer movement restrictions. Hospital discharge at 3–5 days (some centres achieve 1–2 days for selected patients). Physiotherapy commences day 1 with gait training on stairs. Driving is typically permitted at 6–8 weeks post-operatively for the right hip (accelerating leg) in an automatic vehicle and 4–6 weeks for the left hip. Return to desk work occurs at 4–6 weeks; manual work at 3–6 months depending on the role. Swimming and cycling resume at 6–8 weeks. High-impact sports (running, tennis, skiing) are generally discouraged due to implant wear acceleration, though individual surgical guidance varies. Annual follow-up with clinical review and X-ray every 5 years monitors implant stability and early signs of loosening. Contact with a medical alert card is required for procedures with bacteraemia risk (dental extractions, urological procedures) to enable antibiotic prophylaxis.