Joint Replacement — Total Hip and Knee Arthroplasty for End-Stage Arthritis

Patient selection and preoperative optimization

Joint replacement is indicated for end-stage arthritis (Kellgren-Lawrence Grade III–IV) with persistent pain, functional limitation, and failed conservative management (analgesia, physiotherapy, weight management, intra-articular injections). Preoperative optimization improves outcomes: BMI >40 increases complication risk, poorly controlled diabetes (HbA1c >8.5%) increases infection risk, active smoking doubles wound complications, and preoperative anemia increases transfusion requirements. Patient expectations must be aligned with evidence — joint replacement reliably reduces pain and improves function but does not restore athletic capability.

• Indication: Kellgren-Lawrence Grade III–IV with persistent pain despite 3–6 months of conservative care
• Preoperative checklist: BMI optimization, HbA1c <8.0%, smoking cessation ≥4 weeks, dental clearance
• Preoperative anemia: iron supplementation if ferritin <30 — reduces transfusion and infection risk
• Patient expectations: pain relief and walking function are reliably improved; running and high-impact activities are not restored
• Informed consent: discuss risks of infection (1–2%), DVT/PE, stiffness, leg-length discrepancy, revision surgery

Surgical principles and postoperative care

Modern joint replacement uses cemented or uncemented fixation depending on bone quality, bearing surface selection (highly cross-linked polyethylene, ceramic, or metal), and surgical approach (posterior, lateral, or anterior for hip; medial parapatellar for knee). Enhanced recovery after surgery (ERAS) protocols include spinal anaesthesia, multimodal analgesia (nerve blocks, acetaminophen, NSAIDs), early mobilization (same day or day 1), and DVT prophylaxis (LMWH or DOAC for 2–4 weeks). Follow-up includes wound assessment, X-rays, functional scoring (Oxford Hip/Knee Score), and long-term surveillance for wear, loosening, and periprosthetic infection.

• Cemented fixation: preferred in elderly osteoporotic bone; uncemented for good bone quality
• Highly cross-linked polyethylene: standard bearing surface — <0.1 mm/year wear rate
• ERAS protocol: spinal anaesthesia, multimodal analgesia, same-day mobilization, early discharge
• DVT prophylaxis: LMWH or DOAC for 2–4 weeks postoperatively; compression stockings
• Wound care: staples or sutures removed at 10–14 days; shower at 48 hours if wound dry
• Functional milestones: walking with frame at day 1, stair practice at day 2–3, discharge at day 3–5

Guidelines referenced:

• NICE guideline NG157 — Joint replacement (primary): hip, knee and shoulder
• AAOS Clinical Practice Guideline: Management of Osteoarthritis of the Hip
• ERAS Society guidelines for total hip and knee arthroplasty