Flexor digitorum longus transfer and medial displacement calcaneal osteotomy for posterior tibial tendon dysfunction: A middle-term clinical follow-up

Hypotheses/Purpose: The medial displacement calcaneal osteotomy has recentl y become a popular addition to flexor digitorum longus transfer for stage 1 1 posterior tibial tendon dysfunction. We reviewed the results of 26 patien ts who had undergone the procedure at an average of 32 months prior to foll ow-up (range 12 to 70 months) with particular attention to objective functi onal parameters. Conclusions/Significance; FDL transfer and medial displacement calcaneal os teotomy provides good functional and symptomatic results in the middle-term . The operation preserves the majority of subtalar motion and is objectivel y durable as assessed by the continued ability to perform a single-leg toe rise. Although moderate radiographic improvement in the arch is frequent, o ften patients fail to notice this clinically. A prolonged period of steady improvement in symptoms after surgery is common. Summary of Methods/Results: Between 1993 and 1998, 26 patients underwent fl exor digitorum longus transfer and medial displacement calcaneal osteotomy performed by the senior author. Sixteen returned for the study and were see n for physical exams. Three were included on the basis of chart review incl uding 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 tel ephone interviews. For the survival analysis, however, their last physical examination was used as the follow-up date. Two patients who had early tech nical failures were not interviewed but were counted as early failures of t he 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 transf er early in the postoperative course, ultimately requiring revision procedu res 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 notice ably changed, and only one (4%) felt the improvement to be significant. Pai n relief was rated excellent by 75% and good by 16%; the average AOFAS Hind foot pain subscale score was 35.2 (out of 40 possible). Function was felt t o 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 sy mptom categories of the AOFAS score was 26.8 (out of 28 possible). Most patients noted that although they were able to perform daily activitie s after their postoperative immobilization was liberalized, there was a pro longed period of steady improvement in symptoms and function after surgery. The median length of time to self-rated maximal medical improvement was 10 months.