Background
To our knowledge, the medium to long-term outcome after revision knee arthroplasty with structural allograft augmentation for reconstruction of uncontained defects has not been determined. The purpose of the present study was to assess the outcome for patients managed with such a procedure.
Methods
- We prospectively followed 50 patients who had 52 revision knee replacements with 66 structural grafts performed at 3 institutions.
- 29 knees (27 patients) were independently evaluated at a mean of 96.9 months (range, 60 to 189 months) by an investigator who had not been involved in the index procedure.
- 12 knees (23%) had a repeat revision at a mean of 70.7 months (range, 26 to 157 months).
- The allograft was retained in 2 of these patients.
- 11 patients died at a mean of 93 months (range, 61 to 128 months) after the procedure; the structural allograft and implants were intact, and the patients were not awaiting revision at the time of death.
Results
- Clinical evaluation revealed that the mean modified Hospital for Special Surgery knee score had improved from 32.5 points preoperatively to 75.6 points at the time of the review and the mean range of motion had increased from 60.5 degrees preoperatively to 88.6 degrees.
- Failure was defined as an increase of less than 20 points in the modified Hospital for Special Surgery knee score at the time of the review or the need for an additional operation related to the allograft.
- 13 knee replacements failed, yielding a 75% success rate.
- 5 knees had graft resorption, resulting in implant loosening.
- 4 knee replacements failed because of infection, and 2 knees had nonunion between the host bone and the allograft.
- 2 knees (one patient) did not have a 20-point improvement in the knee score.
- The survival rate of the allografts was 72% (95% confidence interval, 69% to 75%) at 10 years.
- On radiographic analysis, none of the surviving grafts had severe resorption, one had moderate resorption, and 2 had mild resorption.
- One knee had a loose tibial component, and 3 knees had nonprogressive tibial radiolucent lines.
- All 4 knees were asymptomatic.
Conclusions
Our results demonstrate that allografts used in revision knee replacement in patients with the difficult problem of massive bone loss have an encouraging medium-term rate of survival.
Copyright remains with the authors and publisher.