High Plantar Force Loading After Achilles Tendon Rupture Repair With Early Functional Mobilization

Abstract

Background: Mechanical loading is essential for tendon healing and may explain variability in patient outcomes after Achilles tendon rupture (ATR) repair. However, there is no consensus regarding the optimal postoperative regimen, and the actual amount of loading during orthosis immobilization is unknown. Purpose: The primary aim of this study was to assess the number of steps and the amount of loading in a weightbearing orthosis during the first 6 weeks after surgical ATR repair. A secondary purpose was to investigate if the amount of loading was correlated to fear of movement and/or experience of pain. Study Design: Case series; Level of evidence, 4. Methods: Thirty-four patients (mean ± SD age, 38.8 ± 8.7 years) with ATR repair were included. Early functional mobilization was allowed postoperatively in an orthosis with adjustable ankle range of motion. During the first postoperative 2 weeks, patient-reported loading and pain were assessed with a visual analog scale and step counts with a pedometer. At the 2- and 6-week follow-up, a mobile force sensor was used for measuring plantar force loading, and the Tampa Scale for Kinesiophobia was used to examine fear of movement. Results: Between the first and second weeks, there was a significant increase in the mean number of daily steps taken (from 2025 to 2753, P < .001) as well as an increase in self-reported loading (from 20% to 53%, P < .001). Patient self-reported loading was significantly associated with the plantar force measurement (rho = 0.719, P < .001). At 6 weeks, loading was 88.2% on the injured limb versus the uninjured limb. Fear of movement was not correlated with pedometer data, subjective loading, pain, or force data. Patients with less pain during activity, however, reported significantly higher subjective load and took more steps (P < .05). Conclusion: This is the first study to demonstrate the actual loading patterns during postoperative functional mobilization among patients with surgically repaired ATR. The quick improvements in loading magnitude and frequency observed may reflect improved tendon loading essential for healing. Pain, rather than fear of movement, was associated with the high variability in loading parameters. The data of this study may be used to improve ATR rehabilitation protocols for future studies. Registration: NCT02318472 (ClinicalTrials.gov).

Does Early Functional Mobilization Affect Long-Term Outcomes After an Achilles Tendon Rupture? A Randomized Clinical Trial

“…The strength of this study is that the EFM protocol used has been assessed in detail when it comes to weightbearing and the number of daily steps taken during the first 2 postoperative weeks. 4 The potential limitations of this study are that there were several orthopaedic surgeons involved in the surgical treatment of the patients and that the physical therapist performing the outcome tests was not blinded to the treatment regimen. Another limitation of the study was that the rehabilitation protocol was not standardized after week 6.…”

“…The number of daily steps taken has been shown to be critical for overall health 1 and is known to be positively correlated with increased loading. 4 Thus, further studies need to assess whether it is the actual amount of loading or the number of steps taken that relates to improved health and vitality.…”

“…The strength of this study is that the EFM protocol used has been assessed in detail when it comes to weightbearing and the number of daily steps taken during the first 2 postoperative weeks. 4…”

Instrumented immobilizing boot quantifies reduced Achilles tendon loading during gait

“…Monitoring patient loading provides clinicians and researchers critical new data to understand the mechanical mechanisms that govern muscle remodeling and tendon healing following Achilles tendon rupture. This approach will also add quantitative data to accelerated rehabilitation paradigms, which is currently limited by a disconnect between actual patient loading and perceived patient loading (Aufwerber et al, 2019).…”

Novel instrumented insole algorithm accurately approximates plantar flexor loading

“…Our findings demonstrate the utility and fidelity of a new method for measuring plantar flexor loading using a commercially available instrumented insole. Quantifying plantar flexor loading is critical for understanding athletic performance [1], mobility constraints in the elderly [2], and treating Achilles tendon injuries [15]. By leveraging this new methodology, it is now feasible to prospectively track and eventually prescribe plantar flexor loading outside of the clinic to improve patient outcomes.…”