Ten-Year Follow-Up of Metatarsal Head Resurfacing Implants for Treatment of Hallux Rigidus

Controversy remains regarding the use of arthroplasty versus arthrodesis in the surgical treatment of late-stage hallux rigidus. The purpose of our retrospective study was to report the long-term follow-up results of the metatarsal head resurfacing implant used for hemiarthroplasty. The patient assessments were conducted using the American Orthopaedic Foot and Ankle Society (AOFAS) metatarsophalangeal clinical rating system and a satisfaction questionnaire. A total of 59 consecutive implantations were performed from January 2005 to December 2009 at our institution. Of the 59 patients, 2 had died and 12 were lost to follow-up, for a 76.3% follow-up rate (45 of 59 procedures) at a mean of 117.67 (range 96 to 143) months. The mean overall AOFAS scale score was 90.6 ± 7.6. The AOFAS pain scale score was 37.78 ± 4.71. One implant was removed, and all remaining patients were happy with their outcome and would repeat the procedure on their other foot, if needed. A subset of patients from a previous mid-term study at our institution showed no significant change in the AOFAS scale scores. Of these 32 patients, 30 (93.75%) were available for follow-up examination at a mean of 122.62 (range 96 to 143) months. We were able to obtain long-term results for 32 implants (30 patients), resulting in a 10-year follow-up rate of 93.7%. With the minimal resection required for this implant, salvage arthrodesis remains a viable option if revision is needed. The surgical treatment of late-stage hallux rigidus with metatarsal head resurfacing allows for low-risk and excellent outcomes at long-term follow-up point.     

Mechanical Comparison of the Youngswick, Sagittal V, and Modified Weil Osteotomies for Hallux Rigidus in a Sawbone Model

The purpose of this study was to compare the mechanical properties of 3 osteotomies often used for hallux rigidus. Maximum load, failure energy, stiffness, and fracture pattern were determined for 3 different test models as well as a control group. Twenty-eight first metatarsal polyurethane sawbone models were equally divided into 4 groups. The osteotomy groups tested consisted of a Youngswick, sagittal V, and modified Weil-type osteotomy of the first metatarsal. Each osteotomy was fixated with a 2.7-mm cortical screw, all 16 mm in length, and a small diameter smooth wire, both placed perpendicular to the osteotomy. Each model was then loaded to failure in a servo-hydraulic material testing machine. Results for maximum load to failure for all 4 constructs showed a mean range of 15.1 to 33.7 N, a mean energy to failure ranging from 0.04 to 0.8 J, and stiffness from 1.5 to 3.4 N/mm. Significant differences in peak load and stiffness (P = .015 for peak load, P = .025 for stiffness) were found between the sagittal V group versus the control and between the modified Weil and sagittal V group (P = .037 for peak load, P = .017 for stiffness). There were no significant differences in the energy to failure between the 4 groups (P > .083). These findings suggest that the sagittal V osteotomy construct was significantly weaker and less stiff than the modified Weil.