Recent Advances in Joint Replacement

The recent advances in joint replacement fall into five areas: longer-lasting implants, partial replacements for younger patients, robotic implantation for precision, better revision surgery, and pain and rehabilitation protocols that let patients move almost without restriction. Dr. Subhash Jangid, then Senior Director, Orthopaedics & Joint Reconstruction at Fortis Memorial Research Institute, Gurgaon, India, set out each of these for international doctors in April 2025.

Dr. Subhash Jangid, currently Principal Director & Unit Head Orthopaedics at the same institute, framed the session around a single proposition: arthroplasty is not just a successful orthopaedic operation, it is one of the most successful procedures in the whole of medicine. Everything else in his talk, from implant chemistry to robotic planning, was about protecting that success for each individual patient. His full profile is on the Dr. Subhash Jangid doctor page.

Joint replacement success rate and implant survival

Arthroplasty, the surgical replacement of a damaged joint, is in Dr. Jangid's view one of the most successful procedures in the whole of medical science. Dr. Jangid cited success rates of 95% and above, with implant survival of 15 to 20 years, and stressed that these are older figures. Pooled national registry data now show about 90% of knee replacements still in place at 20 years and about 82% at 25 years; whether computer navigation and robotic surgery extend this further is not yet established by long-term data.

Demand is rising in step. Dr. Jangid put the growth in procedure numbers at about 10% a year, driven by two forces arriving together: greater awareness among patients, and the procedure's track record. People increasingly expect to keep walking for their entire lives, and they now know an operation exists that allows it. His standing advice to patients is consequently direct: do not wait, because this is an operation from which a patient can recover completely.

The functional ceiling is high. Dr. Jangid showed patients whose replaced knees bend fully, who sit cross-legged and who kneel for prayer.

A victim of its own success

Dr. Jangid described arthroplasty as "a victim of its own success". Because the operation works so reliably in experienced hands, patients and referring doctors come to assume it will work anywhere. When it is performed without proper training, technique or environment, complications follow, and in joint replacement those complications can turn an extremely successful operation into a disaster for the patient.

His conclusion for referring doctors is that the reliability of the procedure is conditional. Good outcomes depend on the centre, the surgeon and the technique together. He framed the clinical goal in operational terms: minimise complications, use resources cost-effectively, and achieve consistent, reproducible results, so that every patient receives the same outcome and the same implant longevity rather than a good result for some and a poor one for others.

What a knee or hip replacement actually replaces

A knee replacement is a surface replacement, not the removal of the whole joint. The operation resurfaces the worn cartilage on the end of the thigh bone (femur) and the top of the shin bone (tibia) with thin metal components. Between the two metal surfaces sits a liner of highly cross-linked, medical-grade polyethylene, a plastic engineered to wear very slowly, and that slow wear is what extends the life of the joint.

A hip replacement follows the same logic with different geometry. A metal stem sits inside the thigh bone, a ball (the femoral head) is fixed on top of it, and a new socket is fitted into the pelvis, with a plastic bearing between the head and the socket. In both joints the principle is the same: a hard, smooth bearing surface against a low-wear liner.

The aims of modern joint replacement

Dr. Jangid set out four aims that define a successful replacement today:

1. Recovery: the patient recovers well and returns to near-normal activity.
2. Function: full mobility of the joint.
3. Stability: the joint feels stable, and the patient does not feel insecure while walking.
4. Survivorship: the implant lasts 25 years or more.

The fourth aim has become more pressing because the patient population has changed. Patients presenting for replacement today are younger, more active and more demanding. They want a joint that feels natural, and because they are young the implant has to last as long as possible. Pooled registry data put survival at about 90% at 20 years and 82% at 25 years for knee replacements, and about 70% at 20 years and 58% at 25 years for hip replacements, and current materials are expected to improve on those figures. The reason this matters is that a revision is not as good as the primary operation: the first operation is the patient's best chance of a durable, normal-feeling joint.

The five recent advances in joint replacement

Dr. Jangid organised the recent advances in joint replacement into five areas of work.

1. Implant durability

Modern implants are designed to outlast earlier generations, although follow-up beyond 25 years is not yet available for current designs. The gains come from bearing materials and surface engineering, described in the next section.

2. Partial replacements for younger patients

Many younger patients have a joint that is only partly worn, with the other half still normal. For them, Dr. Jangid replaces only the damaged half, so that a total knee replacement, if it is ever needed, can be deferred until the patient is past 70. Pooled registry data put survival of partial knee replacements at about 70% at 25 years, below that of total knees. Who qualifies, and at what age, is covered in the age limit for joint replacement and who qualifies.

3. Implantation technique

How an implant is placed matters as much as what it is made of. Robotic implantation places components with more precision. Its early advantages were faster recovery, less pain and a smaller incision. Dr. Jangid expects the biggest advantage to be a longer implant life, which would be decisive for younger patients, although long-term data confirming that robotic placement extends implant survival are not yet available.

4. Revision joint replacement

Revision surgery, the replacement of a failed implant, is a growing part of practice, because implants placed many years ago with older designs are now failing.

5. Pain management and rehabilitation

Post-operative care has been rethought, with rehabilitation that is largely unrestricted and pain relief that avoids drugs harmful to the stomach and kidneys. Both are described below.

Joint replacement implant materials and coatings

On the hip side, Dr. Jangid described bearings of highly cross-linked polyethylene with ceramic components and large femoral heads. Larger heads give a wider range of movement and improve stability, lowering the risk of dislocation.

On the knee side, the metal components can now carry advanced surface coatings, such as oxidised zirconium and titanium niobium nitride, which present a hard, low-friction, ceramic-like surface to the polyethylene. The polyethylene itself is highly cross-linked, and the tibial component is polished so that the wear rate falls further. This is the principle of low-friction arthroplasty: with friction minimised, wear becomes so slow that Dr. Jangid expects implant life of more than 25 to 30 years.

Robotic joint replacement: precision as the route to longevity

The robotic system Dr. Jangid uses is CT-based. A CT scan of the patient's joint creates a three-dimensional model in the robot's software, so the implant can be positioned for that individual's anatomy before the first cut. During surgery, the robotic arm guides the saw within a defined boundary, and the blade cannot travel beyond it into the surrounding soft tissue. The result, in his account, is precise component positioning, a hip, knee and ankle brought into one straight line, quicker recovery and less pain, with a longer implant life the expected but not yet proven long-term benefit.

The full robotic workflow, including the CT mapping accuracy threshold, the planning of deformity correction and his case results, is set out in severe knee deformity correction with robotic surgery.

Pain management and rehabilitation after joint replacement

Dr. Jangid's rehabilitation protocol has become, in his words, more or less unrestrictive. Patients are not told to avoid particular movements. They can do whatever they want except running and jumping, which are impact activities that load the implant heavily.

Pain management follows one principle: avoid medication that harms the stomach or kidneys. Opioids are used at a very low dose, not intravenously but through a transdermal skin patch that releases the drug slowly, or as a nasal spray. Dr. Jangid reported that this gives good pain control without sedation, headache or nausea. The only tablet added is paracetamol, which does not affect the stomach or the kidneys. Paracetamol is safe for the liver at recommended doses but toxic in overdose, so the daily dose needs to stay within standard limits.

The effect is visible on the ward. Dr. Jangid showed a patient walking without any support on the second day after surgery.

Joint replacement for patients from developing countries

Dr. Jangid opened by arguing that the volume and variety of cases treated in India give its surgeons experience with cases that colleagues in the United States, Europe and Australia rarely deal with, because the problems of developing countries differ from those of developed ones. Because many African countries face similar challenges, he suggested, Indian surgeons are well placed to manage the cases African doctors refer. He noted, for example, that knock-knee deformity is the pattern he sees most often in patients from Africa, rather than bow legs.

For complex cases, such as joints with significant bone loss, customised implants are available in India at what he described as a very reasonable cost, with quick recovery. Indicative prices for the most common operations are on the total knee replacement cost page and the total hip replacement cost page.

Joint replacement fellowship for African surgeons

Dr. Jangid also described a one-year fellowship that surgeons from Africa can apply for to learn joint replacement surgery with his team. Applicants write to the team and must register with India's National Medical Commission before joining for the year.

Questions from the session

The questions raised by doctors on the call, on age limits, very elderly patients and post-operative painkillers, are answered in the Live Discussion for this masterclass. Other orthopaedic masterclasses are collected under the orthopaedics specialty, including Dr. Ramkinkar Jha's guide to hip and knee replacement surgery and Dr. Rakesh Mahajan's guide to robotic knee replacement.