Chronic Achilles Tendon Rupture - Perspectives on outcomes after surgical treatment and rehabilitation

Abstract

Chronic Achilles tendon rupture (CATR) is a rupture of the Achilles tendon for which adequate diagnosis and treatment has been delayed after index injury. In this thesis defined as 4 weeks or more. The delay is commonly due to a misdiagnosis by the assessing healthcare professional or because of patient delay. Compared with acute Achilles tendon ruptures (ATR), which have been extensively studied in the recent years, CATRs are to date significantly less researched. Moreover, there is a widespread use of non-validated outcome measurements in the existing literature.

The purpose of this thesis was to determine the outcomes of surgical treatment and postoperative rehabilitation in patients with a CATR from a broad perspective, including several validated outcome measurements. The thesis includes both quantitative and qualitative research methods, and comprises 5 studies evaluating objective and subjective foot and ankle related function, patient experiences, and economic cost.

Study I, a case series, evaluated the 1-year postoperative outcomes and found that the level of recovery varies greatly between individuals. Persistent limitations in subjective foot and ankle function were found and the majority of patients had returned to a light to moderate physical activity level. In terms of calf muscle endurance, some patients recovered well while others had deficits up to 30% to 50% compared with the healthy side. Moreover, an elongation of the injured tendon was found compared with the healthy tendon.

In Study II, gait biomechanics were evaluated preoperatively and 1-year postoperatively. Postoperative gait biomechanics was then compared with a healthy control group. Power development in the ankle and knee joint during gait was significantly improved at the 1-year follow-up compared with the preoperative gait. There were persistent impairments in gait biomechanics compared with healthy controls.

Study III investigated the relationship between calf muscle endurance, gait biomechanics and tendon elongation at 1 year postoperatively. Greater calf muscle endurance was found to be related to better gait biomechanics, especially to power development in the ankle joint. Moreover, the results indicated that less tendon elongation may be related to greater calf muscle endurance.

Study IV, a qualitative interview study, investigated patient experiences related to sustaining, undergoing treatment for and recovering from a CATR, at 4-6 years after surgical treatment. The patients described a traumatic or non-traumatic injury mechanism that resulted in persistent weakness in the foot/ankle that did not improve over time. Receiving the correct diagnosis was a relief, but realizing that the treatment had been delayed due to themself or a healthcare professional initially misinterpreting the injury was frustrating. The patients expressed an overall satisfaction with outcomes, however, some had adjusted their physical activities due to a fear of re-rupture.

In Study V, the healthcare costs and production loss costs of patients surgically treated for CATR were evaluated and compared with the costs of patients treated non-operatively or operatively for an ATR. Furthermore, the study evaluated the preoperative and 1-year postoperative patient-reported foot and ankle function. The study concluded that the healthcare costs were significantly higher for patients treated for a CATR compared with patients treated for an acute ATR, irrespective of treatment. In terms of total costs, surgical treatment of patients with a CATR was more expensive compared with non-surgical treatment of patients with an acute ATR. Patient-reported function was significantly increased postoperatively compared to the preoperative scores.

Taken together, at 1 year postoperatively, significant deficits in subjective and objective function are found in patients with a CATR. Gait biomechanics can be significantly improved compared with the preoperative gait, however not necessarily normalized. Delay of treatment can be a negative experience for the patient and leads to greater healthcare costs compared with an early treatment. This thesis contributes with valuable new findings to the currently very limited state of knowledge in the field. To be able to answer more specific research questions on patients with a CATR, such as predictors of outcome, there is a need for further studies with larger sample sizes that uses validated outcome measurements.