Medio-plantar forefoot approach for distal flexor hallucis longus exposure in checkrein syndrome: Case experience and literature review

Background:Checkrein syndrome is a rare condition characterized by dynamic flexion contracture of the hallux interphalangeal joint (IPJ) and extension contracture of the metatarsophalangeal joint (MTPJ) during ankle dorsiflexion.It most often arises secondary to trauma or iatrogenic injury along the course of the flexor hallucis longus (FHL) tendon.Multiple surgical approaches have been described but no consensus exists regarding the optimal technique Methods:We report the case of a 36-year-old male who developed a painful Checkrein deformity of the hallux following fibular free flap harvest.Conservative measures were unsuccessful.Surgical management consisted of FHL tendon lengthening performed via a medio-plantar forefoot approach.A review of the literature was also performed to summarize available surgical strategies, approaches, and outcomes. Results:The medio-plantar forefoot approach provided direct access to the FHL tendon proximal to the sesamoid sulcus, enabling precise Z-lengthening under intraoperative dynamic assessment.Postoperative recovery was uneventful, with resolution of big toe deformity and motion.Review of published cases demonstrated that Checkrein deformity most frequently follows post-traumatic and iatrogenic causes involving the leg, ankle, or hindfoot.The predominant surgical technique was FHL Z-lengthening, most often performed through a retro-malleolar approach, followed by midfoot and fracture-site-specific exposures.Overall, outcomes across all techniques were favorable, with high rates of deformity correction, motion restoration, and low recurrence. Conclusion:The medio-plantar forefoot approach is a safe and effective surgical option in the management of Checkrein deformity.Its advantage is the targeted exposure and avoidance of extensive dissection but does limit associated lesser toe correction.A review of reported cases indicates that favorable outcomes can be achieved across all surgical techniques when appropriately selected.