A simple technique to perform total knee replacement without violating the femoral canal: early clinical results on a cohort of 303 patients.

BACKGROUND It is becoming increasingly common to find patients candidate for total knee replacement with inaccessible femoral canal due to long femoral hip stems, osteo-synthetic hardware or diaphyseal mal-unions. To treat those patients avoiding complex and expensive procedures, we developed an innovative surgical technique based on a novel device called extra-medullary alignment system. We initially employed this technique in 18 cases with inaccessible femoral canal. Early results were so encouraging that we adopted this technique also for our standard cases. MATERIALS AND METHODS We report here our findings with a first series of 303 consecutive patients performed employing this technique. All patients received a cemented cruciate-retaining mobile-bearing total knee. Patients were followed for a minimum of 2 years and evaluated employing the Knee Society Score and the Oxford questionnaire. We also recorded the surgical time and any complication occurred intra-operatively and postoperatively. Patients' X-rays were as well evaluated. RESULTS No patient was lost to follow-up. Patients group average Knee Society and Oxford scores improved, respectively, from 45 and 16 pre-op to 92 and 45 at 2-year follow-up. Those results were compared and found aligned to those reported by similar historic control groups. Prosthetic implant alignment and surgical time demonstrated to be similar the one obtained using endo-medullary-referenced instruments. In this series, we did not observe any meaningful complication. CONCLUSIONS The extra-medullary alignment system seems to be a simple and reliable technique enabling to perform total knee replacement in a truly minimal invasive manner avoiding femoral canal violation. LEVEL OF EVIDENCE IV.