Il trattamento delle fratture metatarsali e delle metatarsalgie inveterate mediante l’uso di impianti bioriassorbibili: risultati di nuove tecniche chirurgiche

Pathology of the metatarsal region represents one of the most common problem in foot. The treatment of displaced metatarsal fractures and inveterate lesser metatarsalgia remains controversial. Few options exist to treat them and different are the results reported. On the other hand the clinical use of bioabsorbable fixation devices has been fully evaluated in orthopaedic surgery and is becoming preponderant in podiatric literature. Advantages of these implants include: - the lack of necessity for removal at a later date, which results in financial benefits, psychological advantages and decreases the morbidity correlated to a secondary operation. - gradual stress transferring to healing bone during the degradation process which prevents corrosion and stress-shielding phenomenon . Nevertheless one of the complications of their use includes the possibility to develop a late inflammatory soft tissues reaction. With the introduction of SR-PLLA (self-reinforced polylevolactic acid) some of the soft tissues reaction observed to the older polyglycolic implants seem to be reduced and it has been possible to expander their applications. Aims Aware of good results recently obtained with SR-PLLA, in order to reduce complications and patient rest after metatarsal fractures treatment or after metatarsal neck osteotomies for metatarsalgia, we adopted an intramedullary absorbable poly-l-lactic acid pins fixation proposing a new surgical technique. This paper reports on results we have obtained Methods Sixteen patients underwent open reduction and internal fixation of displaced neck metatarsal fractures using biodegradable pins (SR-PLLA) of the following sizes: diameter 3.2 millimetre x length 5.0-6.0-7.0 millimetre. Eight patients underwent circular metatarsal neck osteotomy with absorbable pins of the same sizes. Ankle block anaesthesia was administered for all cases and all procedures were performed under tourniquet control applied at the ankle with the patient in the supine position. Clinical examination and X-ray controls were done three, six, twelve weeks and one year after surgery. In addition all patients were followed up with magnetic resonance imaging (MRI) at one and five years after surgery for metatarsal fractures and 1 year for metatarsalgia. The American Orthopaedic Foot and Ankle Society (AOFAS) lesser metatarsophalangeal-interphalangeal 100-point scale concurrently with the MODEMS TM, (Muscoloskeletal Outcomes Data Evaluation and Management System) Foot and Ankle Booklet were administered to the patients. The results were analysed through widely statistical analysis Results All patients operated healed in about 2 months without prolonged rest or cast immobilization. Serial radiographs showed good alignment of the bone and solid union both at osteotomy site and at the fracture site. Only one case of a foreign body reaction was observed 18 months after a fifth metatarsal fracture fixation. In this case a complete healing without specific treatment was observed two months later.