Abstract
Achilles tendon (AT) rupture may lead to complaints of heel pain. In forefoot ulcer patients AT lengthening is used to transfer pressure from forefoot to the heel. The primary aim was to investigate if AT was longer or associated with changes in pedobaric measurements, in particular heel pressure, on the injured leg 4–5 years after the injury.
Methods
We invited all participants from an RCT (n=56) of conservatively treated AT Rupture (ATR) with or without early weight-bearing (early-WB, non-WB). 37 patients participated, 19 from early-WB (1 re-rupture (RR)), and 18 from non-WB (2 RR). Time from injury to follow up was 4,5 years (4,1 to 5,1). AT length was measured using ultrasound with a validated protocol. Foot pressure mapping (FPM) was measured barefoot, using an EMED platform (novel, Germany), with 5 trials for each foot.
Statistics
T-test for limb to limb comparisons and linear regression for correlations was applied.
Results
We found no differences in any of the variables between the early-WB and non-WB groups.
Compared to the uninjured limb, the Achilles tendon was an average of 1.8 (1.2–2.3) cm longer on the injured limb (p<0.001).
When comparing the ratio of the medial (1–2 ray) to lateral (3–5 ray) forefoot mean peak pressure, we found no difference between the injured and healthy limb (p=0.26)
Mean heel peak pressure was not different from the injured to the healthy leg (difference was 3,9 (−1,7 – 9,45) p=0,17)
Heel lift-off was delayed in the injured limb by 2% (0.4%–4.4%) of the total roll over process (ROP) (p= 0.02).
Achilles tendon length could not be linked to either heels lift-off or mean peak pressure of the heel using linear regression (p 0.27 to 0.78).
Conclusion
Conservatively treated Achilles tendon ruptures were approximately 1.8 cm longer. A subtle change in the time of heel rise could be detected on the injured limb, but contrary to our expectations AT length did not correlate to time of heel lift or mean heel peak pressure. This is in contrast to the common practice in diabetics, where the Achilles tendon is elongated to relieve pressure from the forefoot – a mechanism we cannot observe from elongation of the tendon after acute rupture, treated conservatively - though this study is underpowered.
