Emerging Insights On The First MPJ Arthrodesis
Arthrodesis of the first metatarsophalangeal joint (MPJ) was first advocated in 1894 by Clutton for severe, painful hallux valgus.1 McKeever refined the technique in 1952 using intramedullary screw fixation, which is currently the gold standard for treatment of advanced arthritis and/or significant deformities of the hallux.2 Common indications for arthrodesis include stage 3 hallux rigidus (osteoarthritis), rheumatoid arthritis, failed first MPJ implants, severe hallux valgus deformities and post-traumatic arthritis.3,4
Joint preparation, position, internal fixation and stabilization of the first MPJ are critical to the success of this procedure. While some fixation methods are favored over others, no consensus exists on the optimal technique. Fixation methods include Kirschner wires/Steinmann pins, two crossing screws, dorsal plates or memory staples.4-7 Union rates continue to increase as technique and fixation methods continue to improve. Current studies report fusion rates greater than 90 percent.3-5,7,8
In 2005, Gibson and Thomson performed a randomized control trial to compare the clinical outcomes of arthrodesis with total joint arthroplasty in 63 patients with first MPJ osteoarthritis.9 All patients who underwent arthrodesis fused with few complications while six of the 39 patients in the arthroplasty group required implant removal postoperatively.
At 24 months, there was a significantly greater reduction in pain in the arthrodesis group.9 Overall, only 3 percent of patients in the arthrodesis group said they would not have undergone the same surgery again in comparison to 40 percent of patients in the arthroplasty group.
Functionally, a big concern with patients is the maintenance of their activity level after surgery. In 2005, Brodsky and co-workers followed up with 53 patients 12 months after first MPJ arthrodesis with screw fixation.10 Ninety-eight percent of patients returned to their preoperative jobs/activities with no restrictions and 94 percent could kneel and squat without difficulty.
In another study by Van Doeselaar and colleagues, 62 patients with hallux rigidus underwent successful treatment with fusion of the first MPJ.8 After a median follow-up of 30 months, all patients received the Dutch Foot Function Index (FFI) questionnaire to measure foot function as well as a Visual Analogue Score (VAS) to evaluate pain and patient satisfaction. The FFI scores improved significantly from 38 to 8 and the median VAS pain and VAS satisfaction scores were 6.5 and 5.5 respectively.
According to these studies, first MPJ arthrodesis provides patients with the level of activity, relief of pain and postoperative satisfaction they desire.
Recent literature advocates the use of screw fixation with or without a dorsal plate. In 2008, Sharma and co-workers compared the use of a single interfragmental compression screw versus a screw supplemented with plate fixation in regard to clinical and radiologic fusion of the first MPJ.7
The authors found that the addition of the dorsal plate did not confer any increase in stability or shorten the time to fusion.7 They also noted no difference of statistical significance in patient satisfaction or complications between the two methods. Using a single screw alone provided a union rate of 100 percent in the study.