Gait keepers

Made-to-order knee implants can bring back the spring in your step. Sanchita Sharma reports.

It's now easier to get a pair of perfectly fitted knee joints than a pair of blue denims. All you have to do is ask, says Dr Ashok Rajgopal,chairman, Medanta Bone & Joint Institute, who implanted India's first custom-made knee joints in a woman at Medanta-The Medicity on Friday.

Within 24 hours, she was on her feet resting her 91 kg frame on her made-to-order knees, albeit with support.

When degenerative arthritis (osteoarthritis) fuelled by obesity wrecked her knee joints, Suniti Prasad (name changed), 53, was advised knee-replacement surgery.

Degenerative arthritis is the most common type of arthritis caused by the wear-and-tear of the cartilage in your knee. It develops gradually and causes pain and swelling while standing or walking, stiffness, especially in the morning, and loss of flexibility of the knee joint.

Degenerative arthritis is the leading cause of knee replacement surgery in India, with 60,000 cases performed every year. With rising obesity and falling activity levels, these numbers keep rising each year.

"Prasad's was a typical case of degenerative disease of the knee joints fuelled by obesity and a complete absence pf physical activity. She had no other problems associated with patients that age, such as diabetes or thyroid disorders,” says Dr Rajgopal.

When told about the option of customised joints, she jumped for it. "Nothing beats a perfect fit as the blocks are created to compensate for the degeneration of the bones and cartilage of her knees,” said Dr Rajgopal, who performed the total knee replacement surgery on both knees on December 17. It took him in a little over an hour and a half.

Traditionally, knee replacement is done using artificial joints that fit the patient from a dozen sizes available. Customised knee joints score because they offer perfect alignment to the normal axis of the lower leg, which adds to the functioning and longevity of the replaced joint.

Pre-operatively, an MRI (magnetic resonance imaging) is done to assess the state of the cartilage and any existing deformity in the affected knee. "Next comes virtual surgery using a 360 degree view to assess the fixation to zero error. This helps the surgeon confirm or modify the actual size and fit of the final implant,” he says.

The implant also accommodates anatomical abnormalities of the bones, leading to less damage to the limb and soft tissue and lower use of filler components. A more even stress distribution on the bone-implant interface reduces premature loosening of the joint over time.

"Since the final outcome depends on the fit between the bone surface and the implant, the pre-operative assessments and the quality of fabrication of the custom-designed components is crucial in such cases,” said Dr Yash Gulati, senior ortthopaedic surgeon, Indraprastha Apollo Hospitals.

"Compared to conventional implants that have a life of around 20-25 years, the customised ones are expected to last for 30-35 years, which makes them a good option for young patients with a more active lifestyle,” said Dr Rajgopal, who has three surgeries using customised implants fixed for next week and another 10 over the month. The cost of surgery for both knees is R 85,000 more than conventional knee replacement, which is priced at around R 3.5 lakh in private hospitals.

The price is steeper, but for those who can afford it, there's nothing like a made-to-order knee to replace a damaged one.