Distalization of hinge site with use of hinge wire reduces hinge fracture rates in closing wedge distal femoral osteotomy.

PURPOSE: Closing wedge distal femoral osteotomies (CWDFO) are attractive treatment options for unicompartmental knee osteoarthritis with coronal plane deformity. However, it has been traditionally associated with high rates of hinge fracture that can adversely impact recovery and patient outcomes. Appropriate siting of hinge point can be an effective method of reducing the incidence of hinge fractures. This study aims to illustrate a case series of CWDFO with low rates of hinge fracture utilising our preferred hinge point site. METHODS: A retrospective study of a cohort of 39 CWDFO was performed between May 2019 and May 2022. Both medial and lateral CWDFO were included. The hinge point in all cases was placed at the level of the inferior margin of the metaphyseal flare, and inferior to the gastrocnemius origin, with a hinge thickness of 10 mm. Post-operative radiographs were obtained at 2, 4 and 8 weeks after surgery to assess for hinge fracture and union. RESULTS: Thirty-nine cases of CWDFO were performed, consisting of eighteen cases of valgus malalignment that underwent medial CWDFO and twenty-one cases of varus malalignment that underwent lateral CWDFO. At surgery, the mean age was 47.6 (± 13.9) years and mean BMI was 29.4 (± 4.9). There were 23 men and 16 women. Three cases of hinge fractures occurred intraoperatively, translating into a hinge fracture rate of 7.69%. However, union was achieved in all three cases and all patients in this case series were able to progress to weight bear as tolerated at 2 months post-osteotomy. CONCLUSION: Distal placement of the hinge at the level of the inferior metaphyseal flare margin with the use of a hinge wire can greatly reduce the rates of hinge fracture in CWDFO. LEVEL OF EVIDENCE: Level III.

Low Infection Rates in Total Knee Arthroplasty in End Stage Renal Failure Patients.

End stage renal failure is considered a risk factor for postoperative infection and many surgeons are cautious in offering this group of patients total knee arthroplasty for symptomatic osteoarthritis. In this retrospective study, 16 total knee arthroplasties were performed in 13 patients and each case was followed up for an average of 5.1 years. We report no cases of infection and also an overall improvement in multiple validated outcome measures. There were, however, 2 cases of periprosthetic loosening. As the patients in our series were generally younger and none was diagnosed with stroke or peripheral vascular disease at the time of surgery, we believe that careful patient selection is key to reducing infection rates in this challenging group of patients.