Level IV, retrospective case series.

Between 1993 and 1998, 26 patients underwent flexor digitorum longus transfer and medial displacement calcaneal osteotomy performed by the senior author. Sixteen returned for the study and were seen for physical exams. Three were included on the basis of chart review including one who was deceased and two who could not be contacted. Five further patients included on the basis of chart review were also contacted for telephone interviews. For the survival analysis, however, their last physical examination was used as the follow-up date. Two patients who had early technical failures were not interviewed but were counted as early failures of the procedure in the survival analysis. Functionally, all patients except three could perform a single-leg toe rise at follow-up, a maneuver none could perform preoperatively. Of these three, two cases were technical failures with loss of fixation of the FDL transfer early in the postoperative course, ultimately requiring revision procedures including one subtalar fusion. Another patient was a late failure after developing increasing pain and weakness during a pregnancy 69 months after the procedure. Clinically assessed subtalar motion remained 81 +/- 15% of the contralateral side in those patients with unilateral disease. Although improvement in the radiographic alignment of the foot was commonly noted, only 50% of patients felt the conformation of their foot had noticeably changed, and only one (4%) felt the improvement to be significant. Pain relief was rated excellent by 75% and good by 16%; the average AOFAS Hindfoot pain subscale score was 35.2 (out of 40 possible). Function was felt to be markedly improved by all patients except the three who were unable to perform a single-leg toe rise. The average score for the four functional symptom categories of the AOFAS score was 26.8 (out of 28 possible). Most patients noted that although they were able to perform daily activities after their postoperative immobilization was liberalized, there was a prolonged period of steady improvement in symptoms and function after surgery. The median length of time to self-rated maximal medical improvement was 10 months.

This prospective study demonstrated a statistically significant relative hypermobility of the subtalar and medial column joints following ankle arthrodesis, and may account for the functional gait which can be achieved following ankle arthrodesis. The significantly increased subtalar range of movement appeared to cause impingement of the posterior part of the posterior facet of the subtalar joint which may account for the increased incidence of subtalar arthritis following arthrodesis. Preoperative arch height can be used to predict both residual motion and function after ankle arthrodesis.

This is the largest series of osteochondral total ankle allograft transplants reported in the literature to date. There is an extremely high rate of failure associated with this procedure, and we currently consider it only rarely in patients who are too young for ankle replacement, have excellent range of motion, low body mass index, normal radiographic alignment, and who refuse arthrodesis.

MIDLR/triple is a new treatment option that requires significant care in patient selection and surgical execution. It is a choice that allows for preservation of ankle motion in patients diagnosed with Stage IV-A AAFD who have less than 10 degrees of valgus tibiotalar tilt on preoperative standing ankle radiographs.