Comparative study of medial opening wedge high tibial osteotomy using fixator-cum-distractor device or locking plate in medial unicompartmental osteoarthritis of knee.

OBJECTIVE

The aim of our study was to evaluate the role of medial opening wedge high tibial osteotomy (MOWHTO) in medial unicompartmental osteoarthritis of the knee and compare two different fixation devices for stability, duration, outcome, and complications.

METHODS

Fifty-seven patients (60 knees) of age < 60 yrs and either sex with medial unicompartmental osteoarthritis of the knee were divided into 2 groups. Twenty-four patients (25 knees) in Group I underwent MOWHTO using fixator-cum-distractor and 33 patients (35 knees) in Group II underwent MOWHTO using locking plate osteosynthesis. The results were assessed by VAS, KOOS and WOMAC score.

RESULTS

Mean age of the patients in Group I was 53.13 ± 5.20 years and 51.32 ± 6.91 years in Group II. Mean preoperative varus deviation was 11.97 ± 3.34° in Group I and 11.78 ± 3.05° in Group II which was corrected to 3.27 ± 1.75° and 3.56 ± 1.47° valgus respectively. All the patients achieved full weight bearing by 35th day postoperatively in Group I with the mean of 30.27 ± 2.71 days and 38th day in Group II with the mean of 30.32 ± 3.08. The VAS, KOOS, and WOMAC score improved significantly postoperatively in both the groups.

CONCLUSION

The difference between the two methods of fixation was statistically insignificant. Fixator-cum-distractor is minimally invasive giving good control over the final limb alignment; however, it is cumbersome with less patient compliance and has complications like pin tract infection. Locking plate provides better fixation stability than fixator-cum-distractor even without bone grafting; however, it is an invasive procedure requiring more soft tissue exposure and precise amount of wedge removal.