Dynamic Kinematic and Plantar Pressure Changes Following Cheilectomy for Hallux Rigidus: A Mid-Term Followup

Abstract

Background: Hallux rigidus leads to significant loss of first metatarsophalangeal (MTP) joint motion. Cheilectomy surgery aims to increase motion, decrease pain, and facilitate a return to activity. Limited data exist regarding restoration of dynamic kinematics and loading responses following cheilectomy. This prospective study assessed three-dimensional in vivo first MTP joint kinematics and loading characteristics following cheilectomy. Materials and Methods: Twenty patients were evaluated prior to undergoing cheilectomy for hallux rigidus. Fifteen subjects returned for mid-term followup at 1.7 years. Eleven subjects were surveyed at 6 years. Plantar pressure data were acquired during barefoot walking. Comparisons of average pressures were determined for 4 different regions of the foot. Pressure differences were compared within, and between symptomatic and asymptomatic feet. First MTP joint dorsiflexion and abduction were assessed during standing, active motion and gait. Results: Only four out of 15 patients showed increased lateral metatarsal loading preoperatively. Pressures shifted medially following surgery. Significant increases in dorsiflexion were found for active motion (pre-op = 13.3 ± 12.7 degrees; post-op = 21.7 ± 14.7 degrees, p = 0.005) and dorsiflexion during gait (pre-op = 19.3 ± 12 degrees; post-op = 30.8 ± 14.8 degrees, p = 0.01). Hallux abduction also increased. During standing, the hallux remained in plantarflexion relative to the first metatarsal. Conclusion: Cheilectomy was effective in maintaining balanced plantar loading. First MTP motion increased but dorsiflexion was still less than normative values. The magnitude of dorsiflexion relative to abduction favorably improved during gait. These findings suggest that kinematics continue to be altered and may lead to further degenerative joint changes. Exploration of alternative surgical techniques is warranted.