First MPJ Arthrodesis: What The Evidence Reveals
First metatarsophalangeal joint (MPJ) arthrodesis has shown effective results for stages III and IV hallux rigidus as it can help restore normal foot function and has high patient satisfaction. Accordingly, these authors offer a guide to surgical technique, compare literature results of arthrodesis with those of implants, and present a couple of enlightening case studies.
Arthrodesis of the first metatarsophalangeal joint (MPJ) has been considered the “gold standard” for advanced hallux rigidus. The procedure also has served as the workhorse for revision and salvage of conditions associated with deformity, bone loss and destabilization.
While Clutton originally described the procedure as hallux arthrodesis in 1894, Thompson and McElvenny first popularized MPJ arthrodesis.1,2 They used this surgical approach in patients with poliomyelitis, tuberculosis, hallux valgus and rigidus.2 The two major indications for first MPJ arthrodesis are stage III and IV hallux limitus/rigidus as well as revision and salvage.
There have been many proposed systems to classify hallux limitus/rigidus and the most commonly used systems are the grading systems described by Erdil, Coughlin, Oloff, Drago and their respective co-authors.3-6
The options for surgical management of stage III and IV joints include resection arthroplasty, interpositional arthroplasty, metatarsal head resurfacing, hemi-arthroplasty, total joint arthroplasty, arthrodiastasis and arthrodesis.4,7-19 Each of these procedures has its own advantages and disadvantages. However, in regard to postoperative complications and procedural consequences, the resection interposition arthroplasty remains the treatment to which surgeons compare all other surgical methods. Various authors have compared the outcomes of these other procedures to resection interposition arthroplasty in regard to instability, weakness at push off and first ray shortening.3,10,15
Implant Versus Arthrodesis For Stage III And IV Hallux Limitus/Rigidus
Controversy exists in the podiatric and orthopedic communities as to the best approach for the treatment of stage III and IV hallux limitus/rigidus. The dilemma is whether to fuse the first MPJ or use a joint replacement. Even though the podiatric community has had more than 30 years of experience with the use of joint replacements, these procedures have not had the best long-term results in comparison to the larger joint hip and knee replacement procedures.20,21
A recent multicenter retrospective review of outcomes by Kim and colleagues compared arthrodesis, hemi-metallic joint implant and resectional arthroplasty.22 The article noted AOFAS scores of 90/100 for arthrodesis, 80/100 for hemi-implant and 92/100 for the resection arthroplasty group. These subjective results were not statistically significant. However, patient postoperative complaints were more numerous in the hemi-implant and resectional arthroplasty groups.
The mobility of the first MPJ allows a normal gait pattern and action of the windlass mechanism, which assists in balance, impact reduction and normal stance. It also allows the patient a choice in fashionable footwear.6 These are a few of the reasons it may be preferable for a surgeon and patient to choose implant over arthrodesis.
Silastic implants were developed to achieve these goals. However, the major problem with MPJ implant arthroplasty stems from the frequent need to revise or replace the endoprosthesis. The first-generation Silastic implants have had high failure rates due to the high shear forces on the prosthetic’s hinge.3,23