POSTOPERATIVE REGIMEN AFTER CHEVRON (AUSTIN) OSTEOTOMY: A NEW APPROACH TO IMPROVE FUNCTIONAL OUTCOME

Abstract

Background: The chevron osteotomy is a widely accepted method for the correction of mild to moderate hallux valgus deformity that reveals good to excellent results in terms of radiographic correction of hallux valgus deformity as well as functional outcome scores. However, recent pedobarographic studies have shown that there is decreased load of the big toe region and the first metatarsal head region respectively at a short and intermediate-term follow-up Sufficient load of these structures is essential in order to provide physiological gait patterns. The purpose of the present study was to determine if a modification in the postoperative regimen improves the functional outcome of chevron osteotomy for correction of hallux valgus deformity.

Methods: 29 patients with an mean age of 58 years who suffered on mild to moderate Hallux valgus deformity without radiographic signs of osteoarthritis of the first MTP joint who underwent chevron osteotomy were included in this prospective study. Postoperatively patients were placed in a forefoot relief shoe for 4 weeks. After this period they received a multimodal rehabilitation program including kryotherapy, lymphatic drainage, mobilisation, manual therapy, strnthening exercises and gait training. The patients received a mean of 4.2 treatment sessions and the sessions took place one time a week for 3 to 6 weeks. Preoperatively and one year after surgery plantar pressure distribution parameters including maximum force, contact area and force-time integral were evaluated. Additionly the AOFAS score, ROM of the first MTP and plain radiographs were assessed. The results were compared using Student’s t-test and level of significane was set at p< 0.05.

Results: In the big toe region maximum force increased from 72.2 N presurgically to 106.8 N at one year after surgery, contact area increased from 7.6 cm2 preoperatively to 8.9 cm2 one year postsurgically and force-time integral increased from 20.8 N*sec to 30.5 N*sec. All changes were statistically significant.(p< 0.05) For the first metatarsal head region maximum force increased from 122.5 N presurgically to 144.7 N one year after surgery and force-time integral increased from 42.3 N*sec preoperatively to 52.6 N*sec one year postoperatively. However, those changes were not statistically significant. (p=0.068; p=0.055)The mean AOFAS score increased from 61 points preoperatively to 94 points at follow-up (p< 0.001). The average hallux valgus angle decreased from 31° to 9° and the average first intermetatarsal angle decreased from 14° to 6° respectively.(p< 0.001)

Conclusions: The results of the present study indicate that postoperative physical therapy and gait training help to improve weight-bearing of the big toe and first ray respectively. Therefore, there is a restoration of physiological gait patterns in patients who recieve this postoperative regimen.