Hallux metatarsophalangeal joint arthrodesis using dome-shaped reamers and dorsal plate fixation: a prospective study.

BACKGROUND: Many techniques exist for arthrodesis of the first metatarsophalangeal (MTP) joint, as well as, indications for each method. The purpose of this study was to determine the results of one method using dome-shaped reamers to prepare the joint surfaces and a low-profile dorsal titanium plate for internal fixation. To date, no prospective studies have reported patient outcomes of arthrodesis of the first MTP joint using this technique.

METHODS: Fifty patients (54 feet) had first MTP joint arthrodesis from January, 2004, through January, 2005. All patients were evaluated preoperatively for underlying pathology, pain, function, and radiographic findings. First MTP joint arthrodesis was fixed with a dorsal titanium plate with preset valgus and dorsiflexion after the joint surfaces were prepared with matching male and female dome-shaped power reamers to achieve congruous cancellous bone surfaces. At a minimum of 1-year followup, patients returned for postoperative evaluation. In addition to evaluation of pain, function, and radiographic findings, patients were asked how long they remained off work, how long swelling persisted, and whether the hardware caused symptoms.

RESULTS: Forty-nine of 53 patients returned for followup at an average of 16 months after surgery. American Orthopaedic Foot and Ankle Society (AOFAS) scores improved significantly (z = -6.301, p > 0.01) from an average of 51 points preoperatively (range 24 to 97) to 82 points postoperatively (range 47 to 90). Pain scores at final followup demonstrated a significant improvement (z = -6.154, p > 0.01) from a mean of 6.3 to a mean of less than 1 point on the visual analog pain scale. Time off work averaged 3 weeks, while swelling persisted for an average of 11 weeks. Thirty-five feet in 32 patients (66%) were rated as excellent, 16 feet in 16 patients (30%) were rated as good, and two feet (4%) in one patient were rated as fair, with none reporting a poor result. There were four nonunions (8%), with one being a fibrous union having no progression of deformity. Three of four patients with a nonunion reported a good result subjectively with the fourth reporting a fair result.

CONCLUSIONS: The 96% satisfaction rate in 49 patients indicates that first MTP joint arthrodesis with a low-profile contoured dorsal titanium plate and crossed lag screws after joint preparation with dome-shaped reamers is both reliable and reproducible. The union rate was high (92%), and the revision rate was low (4%).