When a Partial Knee Replacement Needs a Full Revision: Understanding Revision TKR after Unicondylar Knee Replacement, By Dr. Kashyap Solanki – Orthopaedic Surgeon, Andheri - Mumbai

Partial knee replacement, also known as Unicondylar Knee Replacement (UKR), is often an excellent option for patients with arthritis restricted to one compartment of the knee. It allows for a quicker recovery, preserves native ligaments, and often feels more "natural" to the patient.

But this approach isn’t suitable for every case — especially when the overall biomechanics and alignment of the limb aren’t carefully addressed.

Let me share the story of one such patient where a well-intentioned partial knee surgery led to unexpected complications.

Patient Story: When a Partial Knee Replacement Didn’t Go as Planned

A 77-year-old female came to my clinic with severe pain in her left knee, just 2 months after undergoing a Unicondylar Knee Replacement elsewhere. Initially reassured that some discomfort was normal, she grew increasingly concerned when the pain worsened instead of improving, especially while standing or walking.

She was unable to bear weight comfortably and was now completely dependent on a walker.

What We Found: A Hidden Complication

On evaluation, her X-rays revealed a proximal tibial stress fracture below the implant. This type of fracture is rare but serious, particularly in elderly patients with osteoporotic bone.

Critically, her mechanical axis had not been corrected during the UKR. The implant had addressed only the diseased medial compartment but had left the overall limb alignment unchanged — continuing to overload the same part of the tibia.

In essence, the forces that caused her arthritis were still acting on the joint, now amplified through the implant — leading to a stress fracture.

The Next Step: Revision to Total Knee Replacement (TKR)

After discussing the risks and benefits, we proceeded with a Revision Total Knee Replacement. This involved:

• Removing the partial implant

• Addressing the tibial fracture with fixation support

• Inserting a long-stemmed revision TKR implant that bypassed the fracture and redistributed joint forces

• Restoring correct mechanical alignment to prevent future complications

Why Alignment Matters — Especially in the Elderly

UKR is alignment-sensitive. If the mechanical axis isn’t addressed and continues to pass through the degenerated compartment, problems like:

• Fractures

• Implant loosening

• Persistent pain

• Early failure...can occur, particularly in elderly patients with compromised bone strength.

***In many such cases, Primary Total Knee Replacement (TKR) — done correctly the first time — can offer better long-term outcomes and avoid the need for revision surgery.***

Her Recovery: A New Beginning

Postoperatively, we started her on protected weight-bearing with a walker and personalized physiotherapy. Over the following weeks, her pain decreased dramatically. She began walking with improved confidence, and most importantly — without fear.

Final Thoughts

Partial knee replacement can be a game-changer — when done in the right patient, with correct alignment, and sound surgical judgment.

This case is a reminder that sometimes, especially in older patients with complex biomechanics, a full knee replacement from the outset may be the more durable and reliable choice.

Dr. Kashyap Solanki – Specialist in Complex and Revision Hip & Knee Surgeries🔹 Ethical, Evidence-Based Care | 🔹 Advanced Implants & Techniques | 🔹 Andheri East, Mumbai

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