Knee & Shoulder Surgeon - Orthopedic Specialist
Knee & Shoulder Surgeon - Dr. Amyn Rajani
M.S Orth (Gold Medallist), D-Orth, MBBS
Knee and Shoulder Surgeon
(Arthroscopy & Joint Reconstruction)
Orthopaedic Arthroscopy Knee & Shoulder Clinic (OAKS)

Fractures After TKR

Introduction :
Fracture occurring around a knee which has undergone total knee replacement are called peri-prosthetic fractures. Although not very commonly seen, fractures in a prosthetic knee have been reported in international literature. Fractures of Femur, Tibia and Patella can all occur following injury to the prostheically replaced knee.

Peri-prosthetic fracture involving femur :
Risk Factors :
» Femoral notching done during the total knee replacement
» Osteoporosis
» Osteonecrosis of femur

Investigations :
X-Rays:
Anterior-posterior views, lateral views and oblique views are all required.

Conservative Management :
Non operative treatment is avoided, except in patients with excessive co-morbidity.This may include traction or plaster cast.

Surgical Management :
The fractures can be fixed by retrogade nailing of the femur fracture or by fixation with a plate and screws.

Peri-prosthetic fracture involving the tibia :
These fracture usually involve the medial or lateral condyle of the tibia.

Risk factor :
Osteoporosis

Investigations :
X-rays: Anterior posterior views and lateral views

Conservative Management :
» No role of conservative management

Surgical Management :
» Removal of the original tibia tray,
» Fixing a fracture with screws and using bone graft if required.
» If the fragment cannot be fixed then a step cut is done for the tibia and the step is replaced by metal wedge on the tibial tray.

Peri-prosthetic fracture involving the patella :
Risk Factors :
» Not leaving adequate patella after shaving (Patella left behind is less than 12mm)
» Use of central pegged implant
» Devascularisation of patella after a lateral retinacular release
» Excessively thick patella
» Component malalignment

Investigations :
Lateral X-Rays :
Fracture may be missed if undisplaced
Bone scan :
If strongly suspected fracture due to anterior knee pain and not visible on x-ray.

Conservative management : Indicated in the following
» intact extensor mechanism,
» patellar component is in place,
» no comminution,
» displacement is < 2 cm

Conservative management involves immobilization in a plaster cast from groin to ankle for a period of 6 weeks, after which knee is mobilized with the help of continuous passive movement machine.

Surgical Management :
This involves partial or complete patellectomy depending upon whether the component is in place.
Partial Patellectomy : if component is in place.
Complete Patellectomy : if component is loose.

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