Total Ankle Arthroplasty : Short Term follow up Results of Semiconstrained Type and Unconstrained Type

Kang, Kyu Bok; Choi, Jae Hyuck; Kim, Taik Sun; Kim, Hak Jun; Kwon, Jae Ho

Abstract

PURPOSE: The purpose of this study is to compare the two prosthesis that used for total ankle arthroplasty.
MATERIALS AND METHODS
From Sept. 2003 to Jun 2006, 13 patients and 14 ankles that could be follow up more than 1 months. Semiconstrained type (Group I, 7 cases) and Unconstrained type (Group II, 7 cases) were used for total ankle arthroplasty. Mean age was 63.2 year-old, 12 ankles are men and 2 ankles were women. Mean follow up periods were 29 months. The criteria to compare the clinical result were postoperative range of motion, AOFAS score and residual bone stock of medial malleolus.
RESULTS
Postoperative range of motion of group I was 43.6+/-9.4 degrees and of group II was 50.7+/-7.3 degrees (p=0.115). Postoperative AOFAS score of group I was 77.1+/-13.0 points and of group II was 86.0+/-5.7 points (p=0.094). Resected bone stock in medial malleolus of group I was 10.7+/-2.5 mm and of group II was 5.1+/-1.2 mm (p=0.003). Total number of complication in our study was 9 cases. 3 cases were a malleolar fracture, two occurred at intra-operation, the other at follow-up period. Re-operation was done in 6 cases, 3 cases were calcaneal corrective osteotomy, 2 cases were resection of a heterotopic bone and one case was pedicular flap operation for skin problem.
CONCLUSION
In our hospital, mobile bearing type prosthesis shows good result than a semiconstrained type in respect of residual bone stock in medial malleolus. Postoperative range of motion and AOFAS score between two groups shows no significant difference. But small number of patients and short term follow up period is a defect in our study, afterward more population and long term follow up period are needed.