Effects of a tendo-achilles lengthening procedure on muscle function and gait characteristics in a patient with diabetes mellitus

Study Design: Case report with repeated measures. Objectives: To describe the effects of a tendo-Achilles lengthening (TAL) and total contact casting (TCC) on wound healing, motion, plantar pressure, and function in a patient with diabetes mellitus, peripheral neuropathy, neuropathic ulcer, and limited dorsiflexion range of motion (DFROM). Background: Limited DFROM has been associated with increased forefoot pressures and skin breakdown. A TAL was expected to increase DFROM and reduce forefoot pressures during walking, but the influence on muscle performance and function was unknown. Methods and Measures: The patient was a 42-year-old man with a 20-year history of type 1 diabetes (NIDDM) and a recurrent neuropathic plantar ulcer. Outcome measures were DFROM, isokinetic plantar flexor muscle peak torque, in-shoe and barefoot peak plantar pressure, physical performance test (PPT) score, and peak ankle and hip moments during walking obtained from an automated gait analysis. All tests were completed pre-TAL, 8 weeks post-TAL (after immobilization in a TCC), and 7 months post-TAL. Results: The wound healed in 40 days. The TAL resulted in a sustained increase in DFROM (0 to 18°). Plantar flexor peak torque was reduced by 21% 8 weeks after the TAL compared with the torque before surgery but recovered fully at 7 months. Seven months following TAL, in-shoe forefoot peak plantar pressure was reduced by 55%, barefoot pressure decreased by 14%, PPT score increased by 24%, peak ankle plantar flexor moment remained decreased by 30%, and the peak hip flexor moment increased by 41% during walking. Conclusion: For this patient, a TAL resulted in short-term deficits in peak plantar flexor torque, but a 7-month follow-up showed improvements in ankle DFROM, walking ability, and a decrease in forefoot in-shoe peak plantar pressure.