Abstract: BACKGROUND: Bunion is mainly treated by osteotomy and orthopedic surgery, but there is a risk of recurrence and deformity in the postoperative period, so postoperative evaluation of deformity is of great importance. 
OBJECTIVE: To analyze the correlation of the changes in the three-dimensional deformity indicators of the first metatarsal bone after conventional osteotomy for correction of hallux valgus deformity with postoperative functional prognosis, and their guiding significance for clinical treatment. 
METHODS: One hundred patients (feet) with hallux valgus deformity in Department of Hand and Foot Surgery, Hengshui People’s Hospital were selected from January to December 2022, and all of them underwent Scarf osteotomy and orthopedic surgery. Preoperative and 6-month postoperative orthopedic X-rays of the foot in weight-bearing position and simulated weight-bearing position CT films were taken to observe and measure the intermetatarsal angle of the first and second metatarsal bones, tibial lateral sesamoid bone position on orthopedic X-rays of the foot, first metatarsal rotational α-angle, distal articular facet fixation angle, and the angle of the hallux valgus. The correlation of deformity quantifiers at the three-dimensional level of the first metatarsal bone was analyzed, and deformity quantifiers and American Orthopaedic Foot & Ankle Society scores were compared preoperatively and at 6 months postoperatively. The correlation between the quantitative index of deformity at the three-dimensional level of the first metatarsal bone and the American Orthopaedic Foot & Ankle Society score 6 months after treatment was analyzed to evaluate the efficacy of the quantitative indicators of the deformity in predicting functional prognosis.
RESULTS AND CONCLUSION: (1) Before treatment, the hallux valgus angle had no correlation with the first metatarsal rotational α-angle (P > 0.05), but was positively correlated with distal articular facet fixation angle, intermetatarsal angle of the first and second metatarsal bones, and tibial lateral sesamoid bone position on orthopedic X-ray films of the foot (P < 0.05). Distal articular facet fixation angle, intermetatarsal angle of the first and second metatarsal bones, first metatarsal rotational α-angle, and tibial lateral sesamoid bone position on orthopedic X-rays of the foot were all positively correlated (P < 0.05). (2) American Orthopaedic Foot & Ankle Society scores were significantly higher at 6 months postoperatively compared with preoperatively (P < 0.05), and the deformity quantifiers were all lower (P < 0.05). (3) There was a negative correlation of the deformity quantifiers at 6 months postoperatively with the American Orthopaedic Foot & Ankle Society score function, pain, force line, and total score (P < 0.05). (4) The quantitative deformity index of the first metatarsal bone in three dimensions is of high value for the preoperative evaluation, which provides a reference basis for clinical preoperative evaluation and assessment of the efficacy of the treatment, in order to carry out the follow-up treatment, reduce the risk of postoperative recurrence, and improve the prognosis.

Key words: ">hallux valgus deformity, osteotomy and orthopedics, X-ray film, CT, first metatarsal bone, functional prognosis