Study of Subtalar Arthrodesis Using AlloStem® Versus Autologous Bone Graft

Inclusion Criteria:

1. Must be diagnosed with degenerative osteoarthritis, post-traumatic arthritis,
inflammatory arthritis (ie: rheumatoid arthritis) or other conditions of the hindfoot
requiring subtalar arthrodesis.

2. Patients must be able to attend follow-up examinations for the duration of the trial.

3. The patient is at least 18 years of age and skeletally mature, or less than 80 years
of age at the time of surgery.

4. Is willing and able to comply with the clinical trial plan and able to understand and
sign the Patient Informed Consent Form.

Exclusion Criteria:

1. Younger than 18 years old or older than 80 years old.

2. Has a condition that prevents ambulation or completion of any of the trial
measurements.

3. Requires fusion of additional hindfoot or ankle joints simultaneously (i.e. a
pantalar, tibiotalocalcaneal or triple arthrodesis). Concomitant midfoot or forefoot
procedures, such as osteotomies, tendon or metatarsal procedures are not exclusionary.

4. Has treatment planned for the arthrodesis which does not require the use of screws.

5. Has any active infection of the hindfoot, a systemic infection or bacteremia.

6. Has received any treatment within the past 12 months which may interfere with bone
metabolism [bisphosphonates (Fosamax, Actonel, Boniva, Reclast) and calcitonin
(Miacalcin)].

7. Is scheduled to have any surgical procedure on the contralateral foot within 6 weeks
before or after the study procedure.