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Objectives and questions: Sesamoid disorders, including metatarsal sesamoid arthrosis, sesamoid necrosis, sesamoiditis, and sesamoid pseudarthrosis, contribute to 9% of foot and ankle injuries and 1.2% of running-related injuries. When conservative treatments fail to alleviate symptoms, sesamoidectomy (SE) is often considered the final therapeutic option. While previous studies suggest that SE leads to favorable clinical outcomes and enables a swift return to sports, complications such as malalignment, and transfer metatarsalgia have been reported due to altered biomechanical forces in the forefoot. The present study aims to evaluate the clinical outcomes and complication rates following SE.

Material and methods: This single-centre, observational, controlled cohort study investigated patients undergoing SE using retrospective routine data and a prospectively planned follow-up visit (Evidence grade B). The control group comprised matched patients (for sex, age, and follow-up time) treated surgically for Morton Neuroma excision, and was used to account for natural changes in the hallux valgus angle (HVA) over time. The primary endpoint was change in HVA, defined as the difference between follow-up and preoperative measurements; changes greater than 5° were considered clinically relevant. Further, a linear regression model was used to assess the effects of pre-operative HVA, group (removal of the medial, lateral, or both sesamoids vs. control), and their interaction on HVA change. Secondary endpoints in the SE group were the change in intermetatarsal angle (IMA), AOFAS Hallux score, Foot Function Index (FFI), local pain (NRS 0 – 10), satisfaction and adverse events, evaluated at follow-up visit (range 3.9 to 13.8 years).

Results: A total of 26 (9 male) patients undergoing SE (10 medial, 12 lateral, and 4 both) and 26 controls were included. Median follow-up time was 7.8 years (interquartile range, IQR: 5.6 – 10.8). At baseline, the sesamoid group comprised 24 patients with physiological HVA and 2 with mild (>15°) to moderately (>20°) malaligned HVA, compared with 19 and 7 patients in the control group, respectively.We observed one patient (SE medial) and one control with clinically relevant HVA change into valgus direction; other three patients (one of each SE removal type) and four controls had a change of HVA into a better alignment. HVA did not differ significantly between baseline and follow-up. Linear regression revealed, that there was no effect of group, pre-operative HVA, or their interaction on HVA change. There was no change in IMA as well. Follow-up visit after SE showed mean (SD) AOFAS score of 92.8 (9.2), pain of 0.6 (0.8). FFI scores were 11.9 (17.6) for pain and 13.1 (19.7) for disability. Overall, 72% (18 of 26) of patients stated they would undergo SE again.

Discussion and conclusions: Our findings suggest that postoperative HVA malalignment is unlikely when pre-operative HVA is physiological.