A Retrospective Analysis of Outcomes from Foot and Ankle Arthrodesis and Open Reduction and Internal Fixation using Cellular Bone Allograft Augmentation

Abstract

Category: Other; Ankle; Basic Sciences/Biologics; Hindfoot; Midfoot/Forefoot Introduction/Purpose: Surgical arthrodesis of joints in the foot and ankle is common in patients who have failed nonoperative management for a variety of conditions. ViviGen is an allogeneic cellular bone matrix product that contains lineage-committed bone cells, and can be used as an alternative to autograft bone or other augments in order to aid in arthrodesis or to enhance bony healing in open reduction and internal fixation (ORIF) procedures. However, compared with autograft bone, ViviGen does not introduce potential for donor site morbidity. Due to the lack of studies examining outcomes following foot and ankle surgeries in which ViviGen is utilized, further investigation is required to determine its efficacy and safety for use in foot and ankle joint arthrodesis and skeletal fracture fixation. Methods: This study included 153 consecutive patients undergoing ankle, midfoot or hindfoot arthrodesis or ORIF procedures in which ViviGen was used as an augment. Pediatric patients and cases involving structural allografts or metal wedges were excluded. Patients were not excluded based on the amount of ViviGen used, type of instrumentation or implants used, or due to comorbidity. This series included revision as well as primary arthrodesis procedures and included various fixation types. Retrospective chart review was used to identify patient demographic factors and medical comorbidities, as well as to evaluate clinical and radiographic data to determine outcome. Results: 135 patients were available for analysis at final evaluation. 113 patients underwent arthrodesis (mean age of 56.29 years, mean body mass index of 32.19). 22 patients underwent an ORIF procedure (mean age of 36.35 years, mean body mass index of 32.79). The fusion rate for the arthrodesis cohort was 97/113 (85.8%). Table 1 demonstrates the fusion rate stratified by region of the foot. Smokers had significantly lower rates of fusion compared to nonsmokers (p=0.01). There was not a statistically significant difference in the rate of fusion between primary and revision arthrodesis (p=0.8650). The rate of fusion was significantly lower in patients with Charcot foot in comparison to patients without Charcot foot (p=0.0076). The bony healing rate for the ORIF cohort was 19/22 (86.4%). Conclusion: This large case series of patients undergoing a wide variety of procedures about the ankle, hindfoot, and midfoot with ViviGen bone graft augmentation demonstrates satisfactory outcomes with regard to fusion rate and successful union, as well as minimal complications. To date, this is the largest case series in the literature of patients undergoing foot and ankle procedures with an allogenic cellular bone matrix product that contains lineage-committed bone cells. Our findings help to introduce ViviGen as a safe and efficacious alternative to other forms of augmentation for fusion and ORIF procedures about the foot and ankle.