Alternative Management Of Bone Defect In Primary Total Knee Replacement
Authors: Abdullah M.A , Selvanathan N , Kassim S , Kassim A.F , Chopra S 
Published: May 2020

Introduction:

Bone defects are not common in primary total knee arthroplasty (TKA) contrary to a revision setting. The surgeon must assess the degree of complexity preoperatively and intraoperatively and have a broad armamentarium available during surgery. Multiple surgical options are available to repair or reconstruct the loss of bone, these include: bone cement, bone grafts, metal augments and custom-made implants. Principles to consider in bone loss management are knee and patient-related. Bone defects in primary TKA are usually associated malalignment of the limb combined with severe destruction of the articular cartilage. The treatment options for bone defects in primary TKA should be focus on preserving of the host bone, joint line restoration, balancing the flexion /extension stability and stabilizing the prosthesis.

Materials/Methods:

We are presenting a 65 years old lady with severe osteoarthritis bilateral varus deformity with severe bone loss over the posterior tibia condyle. Pre operatively multiple radiographs AP, lateral, patella skyline and oblique view are taken. For this patien we taken CT scan for assessment of the bone defect particularly on the tabia side. The pre operative templating of the radiographs is fundamental important in this patient in planning for primary complex TKA . This patient underwent bilateral total knee replacement with semiconstraint implant with mesh and impaction bone grafting over the posterior apesct of proximal tibia.

Result:

This patient was susseccfully operated with no immediate and post operative complication. Patient which unable to walk because of severe deformity able to gain confidence level to walk and back to her daily living activity

Discussion:

Primary and revision TKA will continue to increase, proper management of femoral and tibia bone loss represents a common situation that have to be faced by the orthopaedic surgeon. Whatever technique is used in management of bone loss during knee arthroplasty, certain fundamentals must be applied and the remaining bone structure will guide treatment. For this case the bone defect was severe uncontained less than 50% of the posterior proximal was lost. Impaction grafting with mesh was performed to create back the proximal tibia. It’s give a new solid platform for the tibia tray to be inserted and this may allow the patient to weight bear immediately post operatively. This will avoid from using fully constrain implant which put more stress on the joint. Periarticular defect requiring more than a minimal prosthetic augment, it is imperative to use stemmed components to transfer stress away from join. Reestablishment of well-aligned and stable implants is necessary, but this can’t be accomplished without a sufficient restoration of an eventual bone loss

Conclusion:

There are several treatment options to deal with a specific bone defect in the primary TKA and these options will be dictated by the patient’s factors, the defect factors and surgeon experience. Careful preoperative planning is essential to ensure successful reconstruction with all the appropriate armamentarium prepared.

References:

Pagano MW, Trousdale RT Tibial Wedge augmentation for Bone deficiency in TKA. Clin Orthop Relats Res. 1995;321:151-5