Impaction bone grafting for tibial defects in knee replacement surgery. Results at two years.

Bone loss with large defects poses a complex and challenging problem in primary and revision knee arthroplasty. The defects are often irregular and difficult to quantify. One of the techniques available to restore bone in such cases is Knee Impaction Bone Grafting (KIBG); however, the clinical literature to support this technique is weak. Since 2006 we have used impaction bone grafting for contained and uncontained large tibial defects in primary and revision total knee arthroplasty. We have prospectively studied 11 patients with large tibial defects treated at the Exeter Knee Reconstruction Unit with KIBG using a short cemented stem following the Slooff-Ling philosophy. Average age was 66 years (41-86 years). Minimum follow-up was 2 years. The Knee Society Scores improved from 27.4 to 89.2 on average, with Knee Society Function score and WOMAC increasing by 263 and 23.2 points respectively. The mean post-operative flexion was 112 degrees. The average gain in motion over preoperative value was 20 degrees. At two years there were no mechanical failures. None of the patients have required secondary procedures or further revisions. All radiographs showed incorporation and remodelling of the graft. The only complication was a superficial dysaesthesia around the operative scar. Although being time consuming and technically demanding, KIBG for substantial tibial bone loss has shown excellent versatility and good short term results, providing a stable construct with immediate weight bearing post operatively. In view of previous concerns regarding early incorporation and stability of impaction bone grafting in the tibia, we present our early results at 2 years. This technique has become our preferred technique for treating substantial bone loss in tibial defects seen in primary and revision knee arthroplasty surgery.