Subtalar distraction arthrodesis using interpositional frozen structural allograft.
BACKGROUND
Subtalar bone-block distraction arthrodesis using structural autograft carries the risk of donor site morbidity. Recent reports suggest that structural allograft may be an attractive alternative to structural autograft in subtalar arthrodesis. This prospective study analyzes subtalar distraction arthrodesis using interpositional structural allograft.


METHODS
Between 2000 and 2006, 22 patients (24 feet; mean age, 45.6 years) underwent subtalar arthrodesis with interpositional fresh-frozen femoral head structural allograft. Indications included subtalar arthrosis, loss of heel height, and anterior ankle impingement. Clinical outcome was assessed using the AOFAS ankle-hindfoot scoring system. Time to union was determined by previously reported clinical findings and radiographic evidence for bridging trabeculation between host bone and structural allograft.


RESULTS
Mean followup was 35.8 months for 20 patients (21 feet) available for followup evaluation. Union was achieved in 19 of 21 patients (90%) at a mean of 15.5 (range, 11 to 19) weeks. Mean AOFAS hindfoot score improved from 21 to 71 points (p < 0.05). Radiographic analysis suggested significant (p < 0.05) improvement in all measurements. Complications included nonunion (2), varus malalignment (1), persistent subfibular impingement (1), sural neuralgia (1), and prominent hardware (2). Both patients with nonunions had avascular bone at the arthrodesis site and used tobacco products.


CONCLUSIONS
This study supports recent publications that subtalar arthrodesis using interpositional structural allograft can have a favorable outcome. Our clinical and radiographic results suggest that restoration of hindfoot function and dimensions with structural allograft are comparable to results reported for the same procedure using structural autograft.


METHODS
Level IV, prospective case series.
Duke Health Center, 3116 N Duke Street, Durham, NC 27704, USA.
David N
DN
Garras
James R
JR
Santangelo
David W
DW
Wang
Mark E
ME
Easley
D000328:Adult; D000368:Aged; D001174:Arthrodesis / Q000379:methods*; D015925:Cryopreservation; D005260:Female; D005269:Femur / Q000637:transplantation*; D005500:Follow-Up Studies; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019857:Osteogenesis, Distraction; D011446:Prospective Studies; D013380:Subtalar Joint; D014182:Transplantation, Autologous; D016896:Treatment Outcome