Cheilectomy with or without Cryopreserved Amniotic Membrane-Umbilical Cord Allograft for Hallux Rigidus: A Prospective Randomized Controlled Trial

Abstract

Category: Basic Sciences/Biologics; Other Introduction/Purpose: Arthritis of the first MTP joint (hallux rigidus) is the most common form of osteoarthritis affecting the foot. Even with advances in interpositional techniques and devices, dorsal cheilectomy remains part of the treatment algorithm after failed conservative treatment of hallux rigidus. Cheilectomy aims to alleviate dorsal impingement and improve pain and function as well as range of motion. However, prospective data on outcomes following this procedure is lacking.Cryopreserved amniotic membrane-umbilical cord (AM-UC) allograft has been shown to mitigate inflammation and decrease scar formation. This has theoretical benefit for improving outcomes following cheilectomy. In the first prospective randomized and blinded cheilectomy study reported, we aimed to compare outcomes between patients undergoing cheilectomy alone and cheilectomy with cryopreserved amniotic membrane-umbilical cord allograft. Methods: After obtaining institutional board review approval, patients were randomized to cheilectomy alone (CA) or cheilectomy with cryopreserved amniotic membrane-umbilical cord (AM-UC). Surgeries were performed by fellowship trained surgeons. Cheilectomy was performed utilizing fluoroscopy to remove ˜25% dorsal articular surface. Cryopreserved AM-UC was applied to cheilectomy site and secured inside capsule with absorbable ‘stay-stitch.’Patients were followed with AOFAS MTP- IP, Foot Function Index (FFI), and VAS-pain (walking, waking, and end of day) outcomes collected preoperatively and at 6 months and 1 year postoperatively. In addition, radiographic range of motion data was collected (maximal dorsiflexion and plantarflexion) utilizing stress radiographs. Power analysis determined 27 patients per group was needed to detect a difference between AOFAS scores of 95 (AM-UC) and 85 (CA). Data was analyzed utilizing statistical analysis software (SAS v9.4). AOFAS, FFI, and VAS scores were analyzed using Wilcoxon signed-rank test. Range of motion data was analyzed using two-way ANOVA with Tukey adjusted least square means test. Results: 51 patients (26 AM-UC, 25 CA) completed the study. There were 5 bilateral surgeries in AM-UC group and 2 in CA group, totaling 31 and 27 feet respectively. Postoperatively, the AM-UC group had improved AOFAS and FFI scores at 1 year compared to CA group but there was no difference at 6 months. There was no difference between groups for VAS-pain scores (walking, waking, or end of day) at any time point, but overall VAS-pain improved in both groups from preoperative values. There was no difference seen in range of motion (total arc) between groups. In addition, changes in range of motion (total arc) in both groups from preoperative to 1 year postoperative were small. Conclusion: We present the results of the first randomized and blinded prospective study of cheilectomy surgery patients. There was improvement in pain, AOFAS MTP-IP, and FFI scores in all patients with statistically significant improvement at 1 year in AOFAS and FFI scores in the cryopreserved amniotic membrane-umbilical cord group compared to cheilectomy alone group. This was despite minimal change in range of motion in both groups. When appropriately selected, cheilectomy remains a good option for patients with symptomatic hallux rigidus. Cryopreserved amniotic membrane-umbilical cord is a potential adjuvant to cheilectomy to modulate inflammation and scarring with 1 year results showing improvements in functional outcome scores.