Sliding Oblique Metatarsal Osteotomy Fixated With K-Wires Without Cheilectomy for All Grades of Hallux Rigidus: A Case Series of 76 Patients

BACKGROUND: Studies on decompression metatarsal osteotomy without cheilectomy for hallux rigidus are limited. This study aimed to review the data of patients who underwent this surgery for all grades of hallux rigidus. METHODS: The medical records of patients who underwent this surgery between August 2017 and January 2021 were retrospectively reviewed. The outcomes were assessed using the visual analog scale (VAS), the Japanese Society for Surgery of the Foot (JSSF) score, and the hallux dorsiflexion angle. Patients who were followed up for more than 2 years were included. The plantar shift of the first metatarsal head (PS) and the shortening of the first metatarsal (SH) were measured to supplementally investigate the associations with other measurements. RESULTS: A total of 76 patients (female, 42; male, 34; mean age, 60.3 years; mean body mass index, 23.1) with 80 feet were enrolled. Six patients (7.5%) were grade 1, 20 (25.0%) were grade 2, 30 (37.5%) were grade 3, and 24 (30.0%) were grade 4. The mean follow-up duration was 3.5 years. Overall, the mean VAS score improved from 63.2 to 6.2, the mean JSSF score from 59.0 to 82.6, and the mean dorsiflexion angle from 37.3 to 56.3 degrees. These measures improved for all grades, but the dorsiflexion angles and JSSF scores decreased as the grade advanced. No clear associations were found between the postoperative VAS and the PS and SH. Eight patients (10.5%) had complications: 4 (5.2%) had occasional plantar discomfort under the metatarsal head, 2 (2.6%) required shoe modification, 1 (1.3%) had wound pain, and 1 (1.3%) experienced breakage of a K-wire. CONCLUSION: The VAS scores, dorsiflexion angles, and JSSF scores improved for all grades of hallux rigidus within a relatively short period of follow-up; however, the dorsiflexion angles and JSSF scores decreased as the grade advanced. LEVEL OF EVIDENCE: Level IV, retrospective case series.