31 July 2026 | Select Doctor

The knee joint is one of the most mechanically demanding in the body, bearing a load equivalent to four to six times body weight during walking. Articular cartilage covers the ends of the femur, tibia, and patella, providing a smooth, low-friction surface for movement.

In osteoarthritis, this cartilage progressively degenerates, thinning, cracking, and eventually wearing away completely in the most advanced cases, leaving bone to articulate directly against bone. The process is driven by age, prior injury, obesity, joint malalignment, and genetic predisposition. As cartilage loss progresses, pain worsens, range of motion decreases, the joint may deform into varus or valgus alignment, and conservative management provides diminishing relief.

Signs That Knee Replacement May Be Needed

Conservative management physiotherapy, anti-inflammatory medication, weight loss, and intra-articular injections should always be exhausted before surgery is considered. These signs indicate that the point has been reached.

●      Pain that persists despite regular medication and physiotherapy, and that is present at rest and at night, not only with activity

●      Significant functional limitation, inability to walk beyond a short distance, climb stairs, or stand for meaningful periods

●      Visible joint deformity, a bow-legged or knock-kneed appearance caused by cartilage loss and bone changes

●      Sleep disruption from joint pain a major contributor to fatigue and quality of life reduction in this patient group

●       X-ray evidence of bone-on-bone arthritis with loss of joint space confirming that there is no cartilage left to preserve

●      Failed intra-articular cortisone or hyaluronic acid injections indicating the joint has progressed beyond the benefit of these interventions

What Is the Right Age for Knee Replacement?

There is no fixed answer. The right time is when the following criteria are met: pain is severe and persistent despite adequate conservative management, functional limitation is significantly affecting quality of life, X-rays confirm advanced arthritis, and the patient is medically fit for surgery. Patients who meet these criteria at 55 should not wait until 65. Patients at 75 who meet these criteria and are physiologically well should not be told they are too old.

Is Knee Replacement Safe at 70 and Beyond?

The clinical evidence is consistent: for appropriately selected patients, knee replacement in old age produces excellent outcomes. Multiple large registry studies show that patients over 70 and over 80 in selected cases achieve comparable pain relief, functional improvement, and implant survival to those of younger patients.

Is knee replacement safe at 70? Yes, when the pre-operative evaluation has identified and optimised the relevant cardiovascular, pulmonary, metabolic, and haematological factors. The assessment is thorough, not to find reasons to refuse surgery, but to ensure the patient enters the operating theatre in the safest possible state.

•   Cardiac evaluation with ECG and echocardiography where indicated, any significant cardiac condition is managed or stabilised pre-operatively

•   Diabetes control HbA1c below 8 per cent is the standard target before elective orthopaedic surgery, as poor glycaemic control increases infection and healing risk

•   Haemoglobin optimisation anaemia increases perioperative risk and is corrected with iron supplementation pre-operatively, where possible

•  Bone density assessment DEXA scans identifies osteoporosis that may affect implant fixation and guides pre-operative management

•  Medication review, anticoagulants, steroids, and certain diabetes medications need adjustment around surgery

If you or a family member has severe knee arthritis that has not responded adequately to conservative treatment, consult a knee replacement surgeon near you at Santosh Hospitals, Ghaziabad's leading knee replacement hospital, for a full evaluation and an honest conversation about what surgery can and cannot achieve.

Frequently Asked Questions

Q1. Does having other conditions like diabetes or heart disease automatically rule out knee replacement in older patients?
 No. These conditions need to be optimised beforehand, not treated as automatic disqualifiers, which is why pre-operative evaluation focuses on stabilising them rather than refusing surgery outright.

Q2. How long does recovery typically take for someone over 70 compared to a younger patient?
 Older patients often take somewhat longer to regain full strength and confidence, but pain relief and functional improvement are comparable to younger patients when pre-surgical fitness has been properly optimised.

Q3. Is it better to wait as long as possible before getting a knee replacement?
 Not necessarily. Waiting well past the point where conservative treatment stops helping can mean months of avoidable pain and muscle weakening, which can actually slow post-surgical recovery.

Q4. Can both knees be replaced in the same surgery if both are severely affected?
 This is possible in select, medically fit patients, though staging the two surgeries separately is more common in older adults to reduce combined surgical and anaesthetic risk.

Q5. Do knee replacement implants wear out, and does that mean revision surgery is likely in old age?
 Modern implants are designed to last many years, and for most older patients the implant is expected to outlast their remaining lifetime, making revision surgery uncommon in this age group.