Abstract
The objective of this study was to consider whether an impaction bone graft (IBG) with their own bone tips surrounded with an X-changed rim mesh was useful when en bloc bone inplantation was not possible for a total knee replacement with large bone defect.
Materials and Method
4 cases and 5 knees (OA: 2 cases 3 knees, RA: 2 cases 2 knees) more than 2 years after the IBG procedure was done using X-changed rim mesh for the large medial tibial defect. All 4 cases were ladies, with the average age being 66.2 years old at that point of the procedure. A medial and posterior release for the connective tissues of knee was performed. The post and pre radiographic evaluations were done by knee society score and JOA score. All the defect or abrasion of the weighted surface was more than 5 mm from the last stage of osteoarthritis. We used a posterior-stabilized type of TKA (Zimmer nexgen), then took radiographs at pre and post operation periods and evaluated the knee scores, FTA, radiolucent line, range of motion and more than 2 years after the operation.
Result
The graft bones were not depressed after more than 2 years and all the patients were satisfied the condition of their knees and made no mention of any knee pain. The average range of motion of their knee joint was: Pre-operation, passive flexion 133°, passive extension -21°; Post-operation, passive flexion 149°, passive extension -3°. All of the patients did not complain during movement and their walking ability including going up and down stairs was not reduced more than 2 years later. The component placement angle was not changed. The radiolucent line of the femur and tibiae did not appear.
The average femoro-tibial angle improved from 197° to 173° over the course of two years. The femoral/tibial component setting angle was not changed more than 2 years after the TKA operation procedure. Radiolucent zone and component sinking was not seen on both side of femur and tibiae.
Conclusion
After this survey we've found that an IBG procedure with an X-changed rim mesh is a good treatment for large bone defect of the tibiae. We can use this technique if we are not able to take out en bloc bone from their own tibiae or if their en bloc bone is crushed into pieces when trying to fix the bone to their tibiae because of bone fragility.
