Patellofemoral Replacement Surgery

. Only when the non-operative treatment options like medication and physiotherapy sessions have eased to provide benefit to the patient, the orthopaedic surgeon recommends this replacement surgery in order to restore basic daily activity without any pain and improve the quality of life. Patient complaints of severe pain impacting basic activities like –

• Sitting with flexed knees for a longer time
• Pain while walking on uneven surfaces
• Staircases climbing
• Getting up from the chair

Some of the common knee joint conditions considered for patella femoral replacement surgery are –

• Degenerative osteoarthritis
• Post-traumatic osteoarthritis
• Extensive Grade 3 chondrosis
• Patellofemoral malalignment/dysplasia-induced degeneration
• Severe symptoms affecting the daily activities

. Radiological imaging like X-ray and MRI scans are prescribed for a better understanding of the extent of damage and planning the treatment plan – surgery in step-by-step manner. 

This replacement surgery is done under general anaesthesia along with a Pain buster and nerve block for optimal pain management. The replacement surgery can be understood as 3 steps –

• Bone preparation for implantation: The incision is done on the front of the knee and special tools are used to open up the patellofemoral compartment of the knee joint to reach to the patella and trochlear groove.
• Implant placement: The damaged part of the patella and trochlear groove (distal end of femur bone) – cartilage and bone, is shaved off or removed with the help of special tools. A metal implant is cemented on the prepared surface of the trochlear groove while a plastic button-like cover is resurfaced on the distal end of the averted patella.
• Closure with suturing: The positioning and movement of the implants are checked by moving the knee along the range of motions and then the wound is closed with sutures.

The patella femoral replacement surgery is shorter surgery compared to the complete knee replacement which lasts approximately for 45-60 minutes. The patient will be shifted to ICU for recovery.

. The patient experiences the following advantages-

• Less surgical trauma and shorter surgery time compared to complete knee replacement surgery and
• Less blood loss and smaller incision size
• Preservation of the natural healthy part of the knee joint (other two healthy compartments of the knee joint like bone, cartilage, and ligaments are maintained)
• Resumption of knee movements and daily chore activities at the earliest
• Shorter hospital stays

The possibility of risk may be –

• Infection/swelling/pain
• Bleeding/blood clot
• Anaesthesia-related complications
• Possibility of early wear & tear of implant and need for complete knee replacement surgery

Following the surgery, the patient is given a step-down approach before discharge from the hospital with aim of regaining independence in doing most of the daily activities by themselves.

• Immediately after the surgery, the patient is shifted to the ICU ward where every parameter of health is monitored closely by the nursing staff
• Patient is shifted recovery room and then to a normal ward.
• The patient is encouraged for knee joint-related movements in spite of pain and many physiotherapy exercises are practiced with specific counts and duration in order to bring back the natural movements and activity.
• The patient is discharged with details on exercises to follow, medication, and a review visit in 4-6 days after surgery.

Post-surgery, physical therapy is started for strengthening the muscle that supports the knee joint. Other therapies that reduce pain and swelling are also followed. Some of the physical exercises are –

• Knee flexion seated
• Straight leg raise
• Knee extensor quadriceps
• Knee flexion lying

The patient progresses from walking with frames to crutches to walking sticks to independent solo walking where weight-bearing capacity is increased with the strengthening of muscle

Post-surgery patient is encouraged for being active with leg and knee joint movements followed by walking with support. The strengthening of the muscles is directly correlated with the resumption of independent active life; faster strengthening of muscles sooner will be the recovery