Outcome of distal metaphyseal metatarsal osteotomy (DMMO) for lesser toe metatarsalgia in a teaching hospital

Introduction: The surgical treatment of intractable metatarsalgia has been traditionally been an intra-articular Weil9s type of metatarsal osteotomy. In such cases, we adopted the option of performing a minimally invasive distal metaphyseal metatarsal ostetomy (DMMO) to decompress the affected ray. The meta-tarsophalangeal joint was not jeopardised. We present our outcomes of Minimally Invasive Surgery for metatarsalgia performed at our teaching hospital. Material and methods: This is a multi-surgeon consecutive series of all the thirty patients who underwent DMMO. The sex ratio was M: F- 13:17. Average age of patients was 60 yrs. More than one metatarsal osteotomy was done in all cases. The aim was to try and decompress the affected rays but at the same time, restore the metatarsal parabola. It was performed under image-intensifier guidance, using burrs inserted via stab incisions. Patients were encouraged to walk on operated foot straight after the operation; the rationale being that the metatarsal length sets automatically upon weight bearing on the foot. Outcome was measured with Manchester-Oxford Foot Questionnaire9s (MOXFQ9s) and visual analogue pain score (VAS). Minimum follow up was for six months. Results: The average MOXFQ score was 26. Average improvement in the visual analogue pain score was 3.5. VAS deteriorated in three patients9 whose pain got worse after surgery. Among these three, two had a further procedure on their toes. All of the patients experience prolonged forefoot swelling for at least 3 months. Discussion: The most common complication after intra-articular ostetomy of the metatarsal head is stiffness of the metatarsophalangeal joint. We believe that using minimally invasive surgery with an extra-articular osteotomy, reduces the soft tissue injury to the joint, and therefore the amount of post-operative stiffness. In our cohort of patients, DMMO is associated with good patient satisfaction and low complication rates in the vast majority of cases.