ObjectiveTo investigate the correlation between fourth brachymetatarsia and hallux valgus, and to provide evidence-based support for clinical decision-making. Methods A retrospective analysis was conducted on 68 patients (89 feet) with congenital fourth brachymetatarsia treated between August 2021 and November 2025. All patients were female, aged 18-44 years (mean, 28.1 years). The hallux valgus angle (HVA), intermetatarsal angle (IMA), and shortening length of the fourth metatarsal were measured on standardized weight-bearing anteroposterior foot X-ray films. Hallux valgus-related complications were recorded. The prevalence of hallux valgus was compared with the reference value reported for the general adult female population in China (14.74%). Spearman rank correlation analysis was used to evaluate the correlations of HVA and IMA with age and metatarsal shortening length. Results In the entire cohort, HVA ranged from 5.65° to 44.95° (mean, 20.56°), IMA ranged from 6.46° to 20.45° (mean, 11.61°), and the shortening length of the fourth metatarsal ranged from 5.62 to 18.01 mm (mean, 12.05 mm). Hallux valgus was present in 55 feet, giving a prevalence of 61.80%, which was significantly higher than the reference value for the general adult female population in China (Z=12.523, P<0.001). Associated symptoms in feet with hallux valgus included bunion (31 feet, 56.36%), transfer metatarsalgia of the second metatarsal head (16 feet, 29.10%), transfer metatarsalgia of the third metatarsal head (10 feet, 18.18%), plantar callosity (8 feet, 14.55%), and dorsal callosity (4 feet, 7.27%). In patients with hallux valgus, HVA ranged from 15.83° to 44.95° (mean, 26.16°) and IMA ranged from 9.01° to 20.45° (mean, 13.35°). Correlation analysis showed that both HVA and IMA were positively correlated with the shortening length of the fourth metatarsal (r=0.290, P=0.016; r=0.420, P<0.001), whereas no correlation was found between HVA or IMA and age (r=–0.061, P=0.751; r=0.132, P=0.525). Conclusion Patients with fourth brachymetatarsia have a significantly higher prevalence of hallux valgus, which is positively correlated with the degree of metatarsal shortening but not with age, suggesting an anatomical rather than age-related etiology. The study redefines the clinical nature of fourth brachymetatarsia, promoting a paradigm shift from “cosmetic correction” to “functional reconstruction”. It is recommended that this deformity be included as a screening indicator for populations at high risk of hallux valgus.
ObjectiveTo evaluate the effectiveness and safety of Ilizarov technique combined with the “joystick technique” for the treatment of fourth brachymetatarsia. Methods A retrospective analysis was performed on 53 patients with fourth brachymetatarsia who met the selection criteria and were treated between August 2021 and January 2025. Patients were divided into two groups according to the surgical method: group A (Ilizarov combined with “joystick technique”, n=19) and group B (Ilizarov alone, n=34). There was no significant difference in baseline data between the two groups (P>0.05), including gender, age, side, preoperative fourth metatarsal length, preoperative shortening of the fourth metatarsal, and American Orthopaedic Foot and Ankle Society (AOFAS) score. The operation time, intraoperative fluoroscopy frequency, total hospitalization costs, and complications were recorded and compared between groups. Metatarsal length was measured preoperatively and at 3 months postoperatively to calculate the lengthening amount. Foot function was evaluated using the AOFAS score preoperatively and at 4 months postoperatively. Patient satisfaction was assessed using a self-designed scale at 4 months postoperatively. Results All surgeries were successfully completed. The operation time and intraoperative fluoroscopy frequency were significantly lower in group A than in group B (P<0.05), while total hospitalization costs showed no significant difference (P>0.05). All patients were followed up, with a follow-up of (6.26±1.52) months in group A and (6.70±1.55) months in group B (t=?0.978, P=0.333). At 3 months postoperatively, the metatarsal lengthening was comparable between the two groups, with no significant difference (P>0.05). At 4 months postoperatively, AOFAS scores improved in both groups when compared with preoperative values, and the change in AOFAS score was greater in group A than in group B, the differences were significant (P<0.05). There were 2 cases of metatarsophalangeal joint stiffness and 1 case of metatarsophalangeal joint dislocation in group A, and 2 cases of nonunion, 2 cases of metatarsophalangeal joint dislocation, 3 cases of metatarsophalangeal joint dislocation with metatarsophalangeal joint stiffness, and 8 cases of simple metatarsophalangeal joint stiffness in group B. No pin-tract infection occurred in either group. The overall incidences of complications were 15.8% in group A and 44.1% in group B, with a significant difference (P<0.05). At 4 months postoperatively, patient satisfaction in group A was significantly better than that in group B (P<0.05). ConclusionThe Ilizarov technique combined with the “joystick technique” can significantly optimize surgical efficiency, reduce intraoperative trauma and the risk of complications, and promote better functional recovery and patient satisfaction. It represents a favorable option for the treatment of fourth brachymetatarsia.
