Stage 4 Osteoarthritis Treatment: Replacement and Revision

The treatment for stage 4 osteoarthritis (Kellgren-Lawrence grade 4), in which the whole joint has lost its cartilage, is joint replacement once medicines, injections and joint-preserving surgery no longer help. For the knee, that means total knee replacement, increasingly with robotic assistance. Severe deformity, bone loss, infection and failed earlier operations call for revision surgery with special implants, and the same principles extend to the hip, shoulder and elbow.

Dr. Ishwar Bohra, Senior Director - Joint Replacement Programme, BLK-Max Super Speciality Hospital, New Delhi, India, devoted the second half of his masterclass on degenerative joint disease to this end of the spectrum. He explained when total replacement becomes the only option, why robotics was developed to fix a problem that conventional surgery left behind, and then walked international doctors through a series of complex knee, hip, shoulder and elbow cases from his own practice. The earlier stages of the disease, from diagnosis to partial knee replacement and high tibial osteotomy, are covered in the complete guide to degenerative joint disease.

Stage 4 osteoarthritis treatment: when total knee replacement is the only option

Total knee replacement is the treatment once stage 4 arthritis involves the whole knee and causes severe pain and loss of function. Dr. Bohra frames total knee replacement as the answer to a specific situation, not a default. The patient has advanced, stage 4 arthritis; medical management has failed; and the time-buying options, alignment surgery, minimally invasive procedures and injections among them, are out of scope. On the X-ray, the arthritis is global: the whole architecture of the knee is involved rather than one compartment.

He named three factors that, together, compel a patient towards total knee replacement:

1. Diffuse arthritis across the joint on X-ray.
2. Severe pain.
3. Functional impairment, a joint that no longer lets the patient walk and live normally.

In a total knee replacement, the worn surfaces of the thigh bone and shin bone, and often the back of the kneecap, are removed and replaced with metal components and a polyethylene (medical-grade plastic) bearing between them. For a patient with stage 4 disease, Dr. Bohra described it as life-transforming surgery.

How long does a knee replacement last?

Modern knee replacements last well. A pooled analysis of national joint registries, published in The Lancet in 2019, put the survival of total knee replacements at about 93% at 15 years, 90% at 20 years and 82% at 25 years, so most patients will not need a second operation on the same knee.

Dissatisfaction after knee replacement: the unhappy patient

Around 15 to 25% of patients remain dissatisfied after conventional total knee replacement, and robotic assistance was introduced partly to close that gap. Dr. Bohra described robotics as the latest advance in joint surgery, and he explained it by starting with the problem it was built to solve.

Conventional knee replacement, guided by the surgeon's hand and experience, produced good results. Yet a group of patients remained dissatisfied. The operation had technically succeeded and they walked well, but they lived with persistent mild pain, stiffness, or a knee that did not feel natural. Dr. Bohra called them the unhappy patients, and he put particular weight on the natural feel of the joint.

He also named three problems that followed manual surgery: early loosening of the implant, wear of the polyethylene bearing, and pain. Robotic assistance was introduced to address them.

Robotic assistance in four steps: map, plan, balance, cut

Dr. Bohra's robotic-assisted knee replacement follows four steps in theatre:

1. Mapping the patient's own joint. Sensors attached to the bones and an infrared camera feed real-time information to the robotic screen, which shows exactly what the patient's joint looks like.
2. Planning. The surgeon plans the implant position on the screen to recreate that individual joint, the patient's own pre-arthritic knee rather than an average one.
3. Balancing. The system balances the joint along every axis and plane of movement it naturally has, so that it is equally balanced in all of them.
4. Cutting. Once he is satisfied with the plan, the robotic arm comes into action and makes all the bone cuts. In his words, his interference at that stage is zero.

The result he described is a joint that feels natural: better gait, better movement and a better sense of the joint for the patient. He reported that robotic surgery has made operations quicker, improved surgical and functional outcomes and reduced patient suffering, which is why it is gaining popularity and acceptance. The evidence is clearest for the precision of implant positioning; long-term comparative data on implant survival and function against conventional surgery are still accumulating.

Robotic knee replacement is covered in depth by other Jivo Healthcare masterclasses, including Dr. Rakesh Mahajan's guide to robotic knee replacement.

Complex knee replacement: deformity, old fractures, neglect and high body weight

Stage 4 knees that are deformed, neglected or carrying high body weight can still be replaced; the most neglected need special implants. The knee cases Dr. Bohra presented ranged from deformity after old fractures to neglected joints and very heavy patients.

• Arthritis after a malunited fracture. A man whose leg fracture had healed in the wrong position developed arthritis because the axis of his leg no longer matched normal anatomy. Before surgery he walked with a painful lateral thrust. Dr. Bohra noted that such cases are very challenging and that robotics gives an extra edge on the results. Ten days after surgery the patient was pain-free and walking without a limp.
• Severe deformity. Videos of another patient showed laboured walking before surgery and, afterwards, a patient smiling and walking without pain or effort.
• Very advanced arthritis with no movement. A woman who could not walk regained mobility with this kind of advanced surgery.
• Neglected disease. Patients who do not take treatment on time can reach the point where the knee is almost subluxed (partly dislocated). They barely walk, often remain in a wheelchair, and their bones become osteoporotic. These knees need special implants with extension rods and a hinged joint.
• High body weight. His heaviest patient weighed 142 kg and was barely able to walk before surgery.

Infected knee replacement: two-stage revision surgery

An infected joint replacement can be salvaged, usually by removing the implants, treating the infection and then rebuilding the joint in a second operation. Infection is the complication Dr. Bohra described as the big challenge in joint replacement. Handling an infected replacement is very complex and needs a lot of patience from both doctor and patient. The infected revision cases he showed had been operated on elsewhere and came to him after they became infected.

His view is that doing the surgery is not the hard part. The hard part is the culture of the operating theatre: a stable surgical environment, consistently good results, and an infection rate driven as close to zero as possible. That, he argued, is why patients need a good centre.

One case illustrated the full process. A patient had both knees replaced elsewhere, and both became infected, a very rare and very challenging situation. The treatment ran in stages:

1. Identify the organism. The bacteria were identified before any definitive surgery.
2. Remove everything. All the implants were taken out.
3. Treat the infection. Special intravenous antibiotics were given for many weeks.
4. Rebuild. Only then was the final reconstruction performed.

Recovery took around six months, and the patient is now well. This staged approach, known as two-stage revision, is the most widely used treatment for chronic infection around a joint replacement. Dr. Bohra's message to referring doctors was reassuring but conditional: an infected joint can be salvaged, provided the patient is referred to a centre whose surgeons are experienced in these cases.

Periprosthetic fractures: breaks around an implant

A fall or accident after joint replacement can break the bone around the implant, a periprosthetic fracture. Dr. Bohra showed examples at both the knee and the hip. These are complex situations: around the knee he treats them with a further prosthetic replacement, and around the hip he showed a fracture fixed to restore a stable joint.

Hip replacement and revision for degenerative and failed hips

Advanced hip arthritis, avascular necrosis and failed earlier hip operations are treated with primary or revision hip replacement. The hip cases covered a wide range of problems:

• Avascular necrosis after COVID-19. Avascular necrosis (AVN) is the death of bone in the femoral head after its blood supply is lost; the head collapses and secondary osteoarthritis follows. Dr. Bohra noted that many younger people developed hip arthritis from AVN after COVID-19, a pattern widely associated with the corticosteroids used in treating the infection. He showed a bilateral hip replacement for AVN with secondary osteoarthritis.
• Revision of a failed hip replacement. A woman from East Africa had a primary hip replacement elsewhere that became loose. He revised the failed hip with a new reconstruction.
• Bone loss. In revision cases, he uses supplementary components (augments) on the socket side and the femoral side. Where the bone is weak, special implants with a long stem anchored inside the bone provide the support.
• Childhood infection. A patient whose hip was damaged by infection in childhood, and who could not walk, needed a very complex operation with a special implant designed for dysplastic hips.
• Severe bilateral arthritis with major bone loss. The bone was reconstructed to form a shell for the socket before the stem was placed, reproducing the original joint.
• Arthritis after a failed fracture fixation. Malalignment from a failed fixation led to degenerative disease of the hip; he removed the old implants and replaced the hip.

The outcomes he showed were functional as much as radiological: one woman whose hip he had reconstructed was later filmed dancing.

Shoulder and elbow replacement for end-stage arthritis

In the cases Dr. Bohra showed, joint replacement also restored function to badly damaged shoulders and elbows.

Reverse shoulder arthroplasty. In one patient with degenerative shoulder disease, the articular cartilage and the muscle around the shoulder had both been lost. The shoulder was very painful and had no function. A reverse shoulder replacement swaps the normal ball-and-socket arrangement, placing the ball on the shoulder blade and the socket on the arm bone, so that the deltoid muscle can power the arm when the rotator cuff muscles no longer work. With this special implant, function returned.

Elbow replacement. Dr. Bohra noted that elbow arthritis is seen mainly in patients with rheumatoid arthritis, who can be crippled by a stiff elbow that does not move. Elbow replacement lets them feed themselves and carry out their daily activities again.

Total knee replacement cost in India

Asked about the cost of a total knee replacement, Dr. Bohra put the approximate figure in his own practice at around 7,000 to 7,500 US dollars. The final cost depends on the patient's choice of room and other options. He described this as not very costly compared with the Western world and the rest of Asia. Jivo Healthcare's total knee replacement cost page sets out typical price ranges from hospital quotations for international patients, and separate pages cover revision and deformity correction surgery, total hip replacement and elbow replacement.

Doctors' other questions from the session, on vitamin D, juvenile idiopathic arthritis and old fractures, are answered on the Live Discussion page.