Outcomes of flexor digitorum longus (FDL) tendon transfer in the treatment of Achilles tendon disorders.

BACKGROUND: In patients with chronic Achilles tendon disorders, Achilles tendon debridement can be supplemented with a tendon transfer, with the flexor hallucis longus tendon (FHL) transfer representing the most common used technique. Our study describes clinical and functional results of patients treated with flexor digitorum longus (FDL) tendon transfer in the treatment of patients with chronic Achilles tendon disorders. METHODS: Retrospective study of prospectively collected data of thirteen patients (15 feet) that underwent FDL tendon transfer as part of the treatment of chronic Achilles tendon disorders. Preoperative and postoperative assessment included visual analogue score (VAS) for pain, SF-36 survey and lower extremity functional scale (LEFS). The average follow-up was 26.4 (range, 14-56) months. Patients were also assessed for ability to perform single leg heel rise test, muscle power for plantar flexion of the lesser toes, surgical scar condition and associated complications. RESULTS: At final follow-up, we found significant postoperative improvement in VAS score (6.6 ±â€¯2.99 vs 1.06 ±â€¯1.43; p < .0001), SF-36 physical component summary (PCS) (28.20 ±â€¯10.71 vs 45.04 ±â€¯11.19; p < .0001) and LEFS (36.13 ±â€¯20.49 vs 58.73 ±â€¯18.19; p < .0001). Twelve patients (92%) could perform a single leg heel rise test in the operated extremity, although there was significant difference when comparing operated and uninvolved sides (4.86 ±â€¯3.36 cm vs 7.18 ±â€¯3.40 cm; p = .0002). One patient reported weakness for plantar flexion of the lesser toes, without balance or gait disturbances. Two patients (2 feet, 13.3%) had superficial infections and one patient (one foot, 6.6%) needed operative debridement for a deep infection. CONCLUSIONS: FDL tendon transfer represent an operative alternative in the treatment of chronic Achilles tendon disorders. Our study showed good clinical outcomes with low complications and donor site morbidity. LEVEL OF EVIDENCE: Observational study, case series - level IV.

☆Diagnostic and therapeutic injections of the foot and ankle-An overview.

Foot and ankle injections are useful diagnostic and therapeutic tools, particularly when the pain etiology is uncertain. A variety of foot and ankle injuries and pathologies, including degenerative joint disease, plantar fasciitis and different tendinopathies are amenable to injections. Understanding the foot and ankle anatomical landmarks, a thorough physical exam and knowledge of the different injection techniques is key for a successful approach to different pathologies. The objective of this study is to review the use of foot and ankle injections in the orthopaedic literature, present the readers with the senior author's experience and provide a comprehensive clinical guideline to the most common foot and ankle diagnostic and therapeutic injections.

Novel animal model for Achilles tendinopathy: Controlled experimental study of serial injections of collagenase in rabbits.

Our goal was to develop a novel technique for inducing Achilles tendinopathy in animal models which more accurately represents the progressive histological and biomechanical characteristic of chronic Achilles tendinopathy in humans. In this animal research study, forty-five rabbits were randomly assigned to three groups and given bilateral Achilles injections. Low dose (LD group) (n = 18) underwent a novel technique with three low-dose (0.1mg) injections of collagenase that were separated by two weeks, the high dose group (HD) (n = 18) underwent traditional single high-dose (0.3mg) injections, and the third group were controls (n = 9). Six rabbits were sacrificed from each experimental group (LD and HD) at 10, 12 and 16 weeks. Control animals were sacrificed after 16 weeks. Histological and biomechanical properties were then compared in all three groups. At 10 weeks, Bonar score and tendon cross sectional area was highest in HD group, with impaired biomechanical properties compared to LD group. At 12 weeks, Bonar score was higher in LD group, with similar biomechanical findings when compared to HD group. After 16 weeks, Bonar score was significantly increased for both LD group (11,8±2,28) and HD group (5,6±2,51), when compared to controls (2±0,76). LD group showed more pronounced histological and biomechanical findings, including cross sectional area of the tendon, Young's modulus, yield stress and ultimate tensile strength. In conclusion, Achilles tendinopathy in animal models that were induced by serial injections of low-dose collagenase showed more pronounced histological and biomechanical findings after 16 weeks than traditional techniques, mimicking better the progressive and chronic characteristic of the tendinopathy in humans.