[Patellar reconstruction during total knee arthroplasty after previous patellectomy]

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Reconstructive surgery

Background:

• Prior total patellectomy can negatively impact knee function after total knee arthroplasty.
• Reconstructing the quadriceps lever arm is crucial for optimal outcomes.
• Limited options exist for restoring extensor mechanism function post-patellectomy.

Purpose of the Study:

• To describe an original technique using an en bloc patellar graft for quadriceps lever arm reconstruction.
• To present preliminary outcomes of this technique in patients undergoing total knee arthroplasty after patellectomy.
• To evaluate the functional improvement and graft viability.

Main Methods:

• Seven patients with prior patellectomy underwent total knee arthroplasty with en bloc patellar graft reconstruction.
• Grafts were fashioned from autologous tibial plateau (6 cases) or homologous femoral head (1 case).
• Transosseous sutures were used for fixation, with polyethylene buttons in five cases.

Main Results:

• Active extension improved significantly post-grafting (1/5 defective knees vs. 5/5 pre-grafting).
• IKS knee and function scores showed substantial improvement (knee: 41 to 78; function: 35 to 72).
• Four of seven grafts were removed due to fixation failure; however, grafts in place showed viability up to 6 years.

Conclusions:

• Patellar autografting can enhance total knee arthroplasty performance in patellectomized knees.
• Improved fixation techniques are necessary to prevent graft migration.
• The technique is a viable option for patellectomized knees, especially with impaired active extension.