First described by Kavanaugh et al in 1978, intramedullary screw fixation is still indicated for proximal fifth metatarsal fractures.1 The simple percutaneous technique allows stable fracture fixation and thus early postoperative weight-bearing and rapid return to preinjury level of competitive sport.
2However, in terms of prognosis, tuberosity avulsion fractures (►Fig. 1; zone 1) must be distinguished from both traumatic fractures at the metaphyseal-diaphyseal junction (true Jones fracture; ►Fig. 1; zone 2) as well as proximal diaphyseal stress fractures (►Fig. 1; zone 3). The latter are a result of repetitive loading leading to failure of the skeletal structure and are associated with longer consolidation times and complications.3 Pes cavus and hindfoot varus foot alignment has been identified to potentiate cyclic loading onto the fifth metatarsal, which favors the incidence of a stress fracture. What is more, diaphyseal blood supply of the fifth metatarsal is ensured solely by the nutrient artery and may therefore be compromised when a diaphyseal fracture occurs, which may subsequently impede fracture healing. 4 In spite of excellent results regarding intramedullary screw fixation for proximal fifth metatarsal fractures, screw breakage or bending has been reported and seems to be related to postoperative early weight-bearing, high patient body mass index (BMI), and the use of undersized screws. 5-7 An intramedullary screw fitting tightly may be of paramount importance.
Case ReportA 19-year-old male professional basketball player presents with pain to the lateral border of his left foot. The symptoms commence immediately after perceiving a snap to the left foot while attempting to jump. Forced inversion or flexion of the foot during injury is denied. Radiographs confirm a transverse stress fracture of the fifth metatarsal (►Fig. 2). Upon clinical examination, bilateral pes cavus and hindfoot varus alignment including peek-a-boo heel sign is observed (►Fig. 3A, B). The patient is scheduled for intramedullary screw fixation with a 4.5-mm cannulated screw.
Surgical TechniqueThe surgical procedure was performed in regional anesthesia. The fracture was identified using a fluoroscan C-arm, and a small incision was made proximal to the base of the fifth metatarsal. An intramedullary guidewire was inserted into the fifth metatarsal and placed across the fracture site. The guidewire was then overdrilled protecting the soft tissue and tendon attachment with a drill sleeve. Counterpressure was placed along the longitudinal axis of the fifth metatarsal, and a correct length screw was inserted and tightened. All threads were placed distal to the fracture site. The screw head was embedded into the cortical part of the styloid Keywords ► intramedullary screw fixation ► proximal fifth metatarsal fracture ► pes cavus ► hindfoot varus
AbstractIntramedullary screw fixation of proximal fifth metatarsal fractures is a simple surgical procedure, enabling early postoperative weight-bearing and subsequently rapid return to competitiv...