Partial Knee Replacement (Unicompartmental Knee Arthroplasty)

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Partial Knee Replacement is an advanced, minimally invasive surgical option for patients with early-stage knee osteoarthritis affecting only one compartment of the knee—most commonly the inner (medial) compartment. In many individuals, arthritis begins as localized wear and tear rather than involving the entire knee joint. When pain cannot be controlled with conservative treatments such as medications, exercises, injections, or lifestyle modifications, partial knee replacement becomes an effective solution.

In this procedure, only the damaged portion of the knee joint is resurfaced using thin layers of specialized metal and polyethylene implants. These components prevent bone-on-bone contact, providing immediate pain relief, while the healthy parts of the knee—including ligaments and unaffected compartments—are preserved. Unlike total knee replacement, partial knee replacement maintains the knee’s natural movement and feel.

The surgery is performed through a small incision (approximately 5–6 cm) at the front of the knee. Since all major ligaments are preserved and less bone is removed, recovery is significantly faster. Most patients can walk on the same day of surgery and are usually discharged within 24 hours. This procedure is especially suitable for the Indian lifestyle, allowing activities such as sitting cross-legged and squatting, and many patients can return to low-impact sports.

Partial knee replacement is particularly beneficial for younger and active patients, typically between 45–65 years, whereas total knee replacement is more commonly recommended for older patients with widespread joint damage.

Benefits of Partial Knee Replacement

• Less bone and soft tissue removal
• Minimal blood loss
• Faster recovery and quicker return of knee movement
• Smaller scar and better cosmetic outcome
• Preservation of natural knee structure
• Less post-operative pain
• Reduced need for prolonged physiotherapy
• Quadriceps muscle sparing

Risks and Limitations

• Higher revision (redo surgery) rate compared to total knee replacement
• Arthritis may progress in the remaining compartments of the knee
• Long-term implant survival may be less than total knee replacement
• Not suitable if multiple compartments are damaged, ligaments are torn, or in inflammatory arthritis

Who Needs Partial Knee Replacement?

Patients who may benefit typically experience:

• Pain while standing or walking
• Pain during position changes (sitting to standing)
• Persistent knee swelling
• Knee locking or giving way
• Poor response to medications or injections
• Pain and stiffness interfering with daily activities

With modern implant designs, improved surgical techniques, and minimally invasive approaches, unicondylar (partial) knee replacement has become a highly successful and reliable procedure. It offers quick recovery, minimal pain, smaller scars, and preservation of the natural knee—making it an excellent option for carefully selected patients with localized knee arthritis.