Recombinant bone morphogenetic protein-2 (rhBMP-2) in high-risk ankle and hindfoot fusions.
BACKGROUND
The purpose of this study was to evaluate the effect of rhBMP-2 on bone healing in patients who undergo high-risk ankle & hindfoot fusions.


METHODS
Patients who underwent high-risk, elective ankle and hindfoot fusions treated with rhBMP-2 augmentation were reviewed for clinical outcomes and complications. A total of 112 fusion sites (69 patients) were reviewed for analysis. The mean age of the patients was 52 years (range, 21 to 84 years). There were 37 males (53%) and 32 females (47%). Forty-four patients (64%) were smokers and 13 patients (19%) were diabetic. A history of high-energy trauma was present in 47 (68%) patients and avascular necrosis of the talus was present in 22 patients (32%). Forty-five patients (65%) had multiple risk-factors. The exclusion criteria were peripheral vascular disease, infection, and patients who were not available for the usual follow-up protocol. Internal and/or external fixation was utilized for ankle and hindfoot fusions. Bone graft was used only for patients who had defects or malalignment. Postoperatively, nonweightbearing radiographs were taken every 2 to 4 weeks (3 views per site). When plain radiographic union was evident, a confirmatory CT scan was obtained.


RESULTS
Overall, 108 fusion sites went on to union (96% union rate) at a mean time of 11 weeks (as assessed by a CT scan) [ankle joint at 10 weeks; subtalar joint at 12.3 weeks; talonavicular joint at 12.7 weeks and calcaneocuboid joint at 10.9 weeks]. Different union times between ankle, subtalar, talonavicular, and calcaneocuboid joint were not significant (p = 0.2571, Kruskal-Wallis Test Nonparametric ANOVA). All sites: [No graft] vs. [Autograft] vs. [Allograft]: p = 0.2421 (Kruskal-Wallis Test Nonparametric ANOVA), were not statistically significant. Complications included nonunion in 5 of 112 joints in 3 patients (4% joint nonunion rate; 4% patient nonunion rate) [subtalar joint, n = 2; talonavicular joint, n = 1; and calcaneocuboid joint, n = 1]. Two patients had wound complications and one other patient had a deep infection; all were successfully treated with local wound care, negative-pressure dressings and antibiotics.


CONCLUSIONS
We believe rhBMP-2 is an effective adjunct for bone healing in patients who undergo high-risk ankle and hindfoot fusions. Low complication rates were observed in this study.
Bibbo
Christopher
C
Department of Surgery, University of Wisconsin School of Medicine and Public Healt, Marshfield Clinic, Marshfield, WI 54449, USA. cbibbo@charter.net
Patel
Dipak V
DV
Haskell
Michelle D
MD
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016512:Ankle Injuries / Q000601:surgery*; D000843:Ankle Joint; D001174:Arthrodesis; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use*; D015331:Cohort Studies; D005260:Female; D017102:Fracture Healing; D006801:Humans; D008297:Male; D008875:Middle Aged; D010020:Osteonecrosis / Q000601:surgery*; D011994:Recombinant Proteins / Q000627:therapeutic use*; D012189:Retrospective Studies; D013640:Tarsal Joints; D016212:Transforming Growth Factor beta / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2