Changes in the ankle muscles co-activation pattern after 5 years following total ankle joint replacement.

BACKGROUND: The Hintegra® arthroplasty provides inversion-eversion stability, permits axial rotation, ankle flexion-extension, and improvements of the gait patterns are expected up to 12 months of rehabilitation. However, sensorimotor impairments are observed in ankle flexors/extensors muscles after rehabilitation, with potential negative effects on locomotion. Here we determined the timing and amplitude of co-activation of the tibialis anterior and medial gastrocnemius muscles during gait by assessing non-operated and operated legs of patients with total ankle replacement, 5 years after surgery. METHODS: Twenty-nine patients (age: 58 [5.5] years, height: 156.4 [6.5] cm, body mass: 72.9 [6.5] kg, 10 men, and 19 women) that underwent Hintegra® ankle arthroplasty were included. Inclusion criteria included 5 years prosthesis survivorship. The onset and offset of muscle activation (timing), as well as the amplitude of activation, were determined during barefoot walking at self-selected speed by surface electromyography. The timing, percentage, and index of co-activation between the tibialis anterior and medial gastrocnemius were quantified and compared between non-operated and operated legs. FINDINGS: The operated leg showed higher co-activation index and temporal overlapping between tibialis anterior and medial gastrocnemius during gait (p < 0.001). INTERPRETATION: The neuromuscular changes developed during the process of degeneration do not appear to be restored 5 years following arthroplasty. The insertion of an ankle implant may restore anatomy and alignment but neuromuscular adaptations to degeneration are not corrected by 5 years following joint replacement.

Prospective randomized clinical trial of aggressive rehabilitation after acute Achilles tendon ruptures repaired with Dresden technique.

BACKGROUND: Rupture of the Achilles tendon is a common injury during working years. Aggressive rehabilitation may provide better outcomes, but also a greater chance of re-rupture. OBJECTIVE: To determine if aggressive rehabilitation has better clinical outcomes for Achilles tendon function, Triceps surae function, one-leg heel rise capacity and lower complication rate during twelve weeks after percutaneous Achilles tendon repair compared to conventional rehabilitation. DESIGN: Randomized controlled trial. METHOD: Thirty-nine patients were prospectively randomized. The aggressive group (n=20, 41.4 ± 8.3 years) received rehabilitation from the first day after surgery. The conventional group (n=19, 41.7 ± 10.7 years) rested for 28 days, before rehabilitation started. The statistical parameters were the Achilles tendon rupture score (ATRS), verbal pain scale, time to return to work, pain medication consumption, Achilles tendon strength, dorsiflexion range of motion (RoM), injured-leg calf circumference, calf circumference difference, one-leg heel rise repetition and difference, re-rupture rate, strength deficit rate, and other complication rates. Mixed-ANOVA and Bonferroni's post hoc test were performed for multiple comparisons. Student's t-test was performed for parameters measured on the 12th week. RESULTS: The aggressive group with respect to the conventional group had a higher ATRS; lower verbal pain score; lower pain medication consumption; early return to work; higher Achilles tendon strength; higher one-leg heel rise repetitions; and lower one-leg heel rise difference. The re-rupture rate was 5% and 5%, the strength deficit rate was 42% and 5%, and other complications rate was 11% and 15% in the conventional and aggressive group, respectively. CONCLUSION: Patients with Dresden repair and aggressive rehabilitation have better clinical outcomes, Achilles tendon function and one-leg heel rise capacity without increasing the postoperative complications rate after 12 weeks compared to rehabilitation with immobilization and non-weight-bearing during the first 28 days after surgery.