Treatment of Hallux Rigidus With Synthetic Hemiarthroplasty Versus Cheilectomy: A Randomized Controlled Trial

Hallux Rigidus is a common disorder that affects an estimated 1 in 40 people over the age of 50.4 While debate remains about the primary cause of this disorder, it is likely multifactorial with contributing factors including previous trauma, malalignment and underlying genetic influences.5 Regardless of the cause, the disorder can become progressive and significantly impact a patient's quality of life. Common symptoms include pain, swelling and limited range of motion. Patients often present with pain dorsally over the first metatarsophalangeal (MTP) joint secondary to osteophyte formation and swelling. This can restrict range of motion at this joint, as well as make daily activities, such as wearing closed-toed shoes, quite difficult.6 Furthermore, continued pain can lead to gait abnormalities with more weight bearing through the lateral aspect of the foot and potential transfer metatarsalgia.7

Along with physical exam to identify first MTP range of motion, joint swelling, erythema and palpable osteophyte formation, radiographic evaluation is part of the standard of care in hallux rigidus evaluation. Coughlin and Shurnas proposed a grading system that has become widely used, based on the radiographic findings and range of motion at the MTP joint.8 The grading system allowed clinicians to characterize patients from grade 0-4, helping guide treatment decisions.

Initial treatment is centered on pain relief with non-operative modalities. Modified shoe wear, custom orthotics with a Morton extension and activity modifications have all been shown to improve symptoms in some patients.7 For patients that fail non-operative therapies, a wide array of surgical options exist. For patients with Grade 1 and 2 hallux rigidus, joint sparing procedures have been primarily used, with the most common procedure being Cheilectomy. The Cheilectomy procedure involves removal of the dorsal osteophytes and 20-30% of the dorsal metatarsal head.3 The benefits of this procedure include the ability to improve joint mobility, while still leaving the potential for future fusion. Success rates have been reported between 72% and 100% in patients with grade 1 and 2 hallux rigidus.7 Controversy remains regarding cheilectomy in patients with grade 3 hallux rigidus however. Nicolosi et al found an average satisfaction rate of 85% in patients with grade 3 disease undergoing cheilectomy3. Additional studies, however have suggested high failure and revision rates in patients with grade 3 hallux rigidus.3

Joint fusion has become common place in the treatment of advanced stage hallux rigidus, including grade 3 and 4. High fusion rates and patient satisfaction has been proven with fusion procedures in the first MTP joint.7 However, the loss of motion at the first MTP joint associated with the fusion procedure can interfere with activities such as running and jumping, and can make shoe wear choices difficult2. These limitations led to the push for development of a joint replacement procedure, allowing for pain control and continued motion.

The use of silicone-based joint replacement has been met with mixed results, however concerns over the durability leading to implant fracture, osteolysis and difficulty of revision procedures has ultimately limited its use.9 Ceramic implants were found to have good short-term results, however concerns remain regarding the large amount of subsidence seen in follow up, as well as potential osteolysis10. Furthermore, the amount of bone stock remaining following this procedure could make revision procedures quite challenging. Given these mixed results, there remained a significant drive to identify a joint replacement-type procedure with a device that could maintain adequate bone stock, preserve motion and withstand the daily stresses the first MTP joint faces.