AOFAS Functional Scoring After Antegrade K Wires Fixation of Multiple Metatarsal Neck Fracture: A Case Report
Authors: Santoso Adantio Rashid , Gunawan Hendra 
Published: November 2019

Introduction & Objectives: Metatarsal Bone fractures contribute 3-7% of all fractures of the body, 35% of all fractures from the foot and also contribute 75 new cases per 10.000 persons per year. Another study evaluated the incidence involvement of multiple metatarsal fractures is higher than isolated metatarsal fractures. Metatarsal bone fractures mostly caused by low energy trauma, and also high energy trauma makes the incidence higher. The previous study said, that 43% of metatarsal fractures are the neck of the second and third metatarsal bones. Intramedullary fixation using Kirschner (K) wires has been chosen as a method of operative treatment for metatarsal bone. There are several outcome evaluation instruments for those who sustained a complex ankle or hindfoot injury. Among them, The American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score is commonly chosen by orthopedics for a quantitative and objective measurement. This study wants to evaluate the results obtained through AOFAS Scoring for fractures of the metatarsal neck, represent the clinical and functional results after K-wire management in surgery.

Case Report: A 35-year-old man has admitted to the ER with a chief complain of a painful right hindfoot. Previously, a brick fell upon his hind foot while he was working to repair a wall with nothing to protect his hind foot. In our case, direct trauma due to falling object upon of his dorsal hindfoot caused neck fractures of 2nd - 4thmetatarsal bones, which had confirmed by X-Ray photos. His hind foot had been swelling and his fingers were barely able to do flexion and extension. We waited until the edema regresses for the surgery, in order to reduce the risk of developing compartment syndrome. In our case, we delayed surgery for 2 days. An antegrade K wires fixation is achieved by using antegrade wire insertion at the fracture site followed by retrograde fixation of the proximal fragment with the same wire. We have been following the patient from the beginning until 6 months after the K Wires fixation surgery in an outpatient clinic, and also the patient was kept no-weight-bearing within 2 months.

Results & Discussion: In 2 months after the surgery, we did the X-Ray and it showed a callus formation. Then we expelled the K wires. We prospectively evaluated the outcome trough the AOFAS score and the score was 95 in the 6th month of the evaluation. We chose antegrade introduction of the K Wires for the best outcome, prevent a high rate of complications related to this type of treatment, minimize soft tissue insult to avoid the unsatisfactory outcome. When metatarsal bone fracture happened and did more than 10 degrees of angulation, it could make a disturbance of load distribution under metatarsal head that leads to mechanical metatarsalgia. Besides, it can also produce painful calluses and traumatic neuroma formation lead to painful trauma and then disturb a function of the lower limb. The antegrade approach prevents plantar displacement of the distal metatarsal fragment during K-wire insertion continues with an exteriorization by the retrograde manner of the wire in the plantar region. The study said that no complications were identified related to using the type of treatment. Another study said that a patient treated by a percutaneous antegrade surgical approach, had higher AOFAS scores, averaging more than 95 points within the 6th-month postoperative period. Inadequate fracture reduction, failure of fixation and pin-site infection could lower the AOFAS Score.

Thus Percutaneous antegrade surgical treatment is an effective treatment for metatarsal fractures, with a lower incidence of complications.

Conclusions: A metatarsal bone fracture that not treated properly can lead to changes in gait and foot load distribution, as it would decrease the point of AOFAS Score evaluation. We expect that the AOFAS Ankle-Hindfoot Score could give an objective quantitative scoring for the patients’ foot function, not only after the trauma but also after the surgery. A proper diagnosis and management of this fracture result in a good prognosis and low complication rates, presented by higher AOFAS Score.