Hallux rigidus: demographics, etiology, and radiographic assessment.

PURPOSE: The purpose of the study was to evaluate the demographics, etiology, and radiographic findings associated with hallux rigidus in patients treated surgically over a 19-year period in a single surgeon's practice.
METHODS: Patients treated for hallux rigidus by cheilectomy and metatarsophalangeal joint fusion were identified from 1981 to 1999. Patients who had diabetes, inflammatory arthritis, infectious arthritis, crystalline arthritis, multiple forefoot deformities, neuromuscular disorders, or had died were excluded. A chart review and evaluation of preoperative radiographs were completed on all eligible patients. All identified patients were invited for a follow-up examination that included standard and stress radiographs, range-of-motion testing, Harris mat study, gait analysis, first ray mobility measurement, and standardized questionnaire assessment.
RESULTS: One hundred ten of 114 (96.5%) patients with a diagnosis of hallux rigidus returned for the final evaluation. Eighty cheilectomy patients (93 feet) and 30 arthrodesis patients (34 feet) were evaluated. The mean age at onset in the current study was 43 years (13-70 years) and only six patients developed symptoms at an age of less than 20 years. Hallux rigidus was graded based on a five-grade clinical-radiographic system. The mean follow-up was 8.9 years. Ninety-five percent of patients with a positive family history had bilateral disease at the final follow-up. At the initial examination in the current study, 81% of patients had radiographic and clinical evidence of unilateral disease, but at the final follow-up 79% of patients had radiographic and clinical evidence of bilateral disease. Eleven percent of patients in the present series had pes planus based on either a positive Harris mat study and/or heel valgus. There was no evidence of an Achilles or gastrocnemius tendon contracture. Radiographic analysis found that the concurrent presentation of hallux valgus and hallux rigidus was not common. Ninety-three of 127 feet (73%) had a chevron or flat metatarsophalangeal joint. Thirty-five feet were noted to have mild or moderate metatarsus adductus. A long first metatarsal was no more common in patients with hallux rigidus than in the general population. The mean first ray elevatus was 5.5 mm and was well within acceptable limits of normal. The mean first ray mobility was 5 mm in arthrodesis patients and 5.8 mm in cheilectomy patients.
CONCLUSION: Hallux rigidus was not associated with elevatus, first ray hypermobility, a long first metatarsal, Achilles or gastrocnemius tendon tightness, abnormal foot posture, symptomatic hallux valgus, adolescent onset, shoewear, or occupation. Hallux rigidus was associated with hallux valgus interphalangeus, bilateral involvement in those with a familial history, unilateral involvement in those with a history of trauma, and female gender. Metatarsus adductus was more common in patients with hallux rigidus than in the general population but a clear correlation was not found. Additionally, a flat or chevron-shaped metatarsophalangeal joint was more common in hallux rigidus patients.