Ageing, deep vein thrombosis and male gender predict poor outcome after acute Achilles tendon rupture.

AIMS: Patients with an acute Achilles tendon rupture (ATR) take a long time to heal, have a high incidence of deep vein thrombosis (DVT) and widely variable functional outcomes. This variation in outcome may be explained by a lack of knowledge of adverse factors, and a subsequent shortage of appropriate interventions. PATIENTS AND METHODS: A total of 111 patients (95 men, 16 women; mean age 40.3, standard deviation 8.4) with an acute total ATR were prospectively assessed. At one year post-operatively a uniform outcome score, Achilles Combined Outcome Score (ACOS), was obtained by combining three validated, independent, outcome measures: Achilles tendon Total Rupture Score, heel-rise height test, and limb symmetry heel-rise height. Predictors of ACOS included treatment; gender; age; smoking; body mass index; time to surgery; physical activity level pre- and post-injury; symptoms; quality of life and incidence of DVT. RESULTS: There were three independent variables that correlated significantly with the dichotomised outcome score (ACOS), while there was no correlation with other factors. An age of less than 40 years old was the strongest independent predictor of a good outcome one year after ATR (odds ratio (OR) 0.20, 95% confidence interval (CI) 0.08 to 0.51), followed by female gender (OR) 4.18, 95% CI 1.01 to 17.24). Notably, patients who did not have a DVT while immobilised post-operatively had a better outcome (OR 0.31, 95% CI 0.12 to 0.80). CONCLUSION: Over the age of 40 years, male gender and having a DVT while immobilised are independent negative predictors of outcome in patients with an acute ATR. Cite this article: Bone Joint J 2016;98-B:1635-41.

Intermittent pneumatic compression reduces the risk of deep vein thrombosis during post-operative lower limb immobilisation: a prospective randomised trial of acute ruptures of the Achilles tendon.

Deep vein thrombosis is a common complication of immobilising the lower limb after surgery. We hypothesised that intermittent pneumatic compression (IPC) therapy in outpatients who had undergone surgical repair of acute ruptures of the Achilles tendon could reduce the incidence of this problem. A total of 150 patients who had undergone surgical repair of the Achilles tendon were randomised to either treatment with IPC for six hours per day (n = 74) under an orthosis or treatment as usual (n = 74) in a plaster cast without IPC. At two weeks post-operatively, the incidence of deep vein thrombosis was assessed using blinded, double-reported compression duplex ultrasound. At this point, IPC was discontinued and all patients were immobilised in an orthosis for a further four weeks. At six weeks post-operatively, a second compression duplex ultrasound scan was performed. At two weeks, the incidence of deep vein thrombosis was 21% in the treated group and 37% in the control group (p = 0.042). Age over 39 years was found to be a strong risk factor for deep vein thrombosis (odds ratio (OR) = 4.84, 95% confidence interval (CI) 2.14 to 10.96). Treatment with IPC, corrected for age differences between groups, reduced the risk of deep vein thrombosis at the two-week point (OR = 2.60; 95% CI 1.15 to 5.91; p =0.022). At six weeks, the incidence of deep vein thrombosis was 52% in the treated group and 48% in the control group (OR 0.94, 95% CI 0.49 to 1.83). IPC appears to be an effective method of reducing the risk of deep vein thrombosis in the early stages of post-operative immobilisation of outpatients. Further research is necessary to elucidate whether it can confer similar benefits over longer periods of immobilisation and in a more heterogeneous group of patients.

Can foot compression under a plaster cast prevent deep-vein thrombosis during lower limb immobilisation?

We hypothesised that adjuvant intermittent pneumatic compression (IPC) beneath a plaster cast would reduce the risk of deep-vein thrombosis (DVT) during post-operative immobilisation of the lower limb. Of 87 patients with acute tendo Achillis (TA) rupture, 26 were prospectively randomised post-operatively after open TA repair. The treatment group (n = 14) received two weeks of IPC of the foot for at least six hours daily under a plaster cast. The control group (n = 12) had no additional treatment. At two weeks post-operatively all patients received an orthosis until follow-up at six weeks. At two and six weeks the incidence of DVT was assessed using colour duplex sonography by two ultrasonographers blinded to the treatment. Two patients withdrew from the study due to inability to tolerate IPC treatment. An interim analysis demonstrated a high incidence of DVT in both the IPC group (9 of 12, 75%) and the controls (6 of 12, 50%) (p = 0.18). No significant differences in incidence were detected at two (p = 0.33) or six weeks (p = 0.08) post-operatively. Malfunction of the IPC leading to a second plaster cast was found to correlate with an increased DVT risk at two weeks (ϕ = 0.71; p = 0.019), leading to a premature abandonment of the study. We cannot recommend adjuvant treatment with foot IPC under a plaster cast for outpatient DVT prevention during post-operative immobilisation, owing to a high incidence of DVT related to malfunctioning of this type of IPC application.

Metabolic activity in early tendon repair can be enhanced by intermittent pneumatic compression.

Since Achilles tendon healing is protracted, more knowledge of metabolites known to meet the demands for biosynthesis and proliferation is needed. We hypothesized that essential metabolites, glutamate, glucose, lactate, pyruvate and glycerol, are present and upregulated in healing Achilles tendons. We moreover hypothesized that adjuvant intermittent pneumatic compression (IPC), which increases blood flow, upregulates metabolite concentrations. Twenty patients with acute Achilles tendon rupture were recruited, operated, and included. The control group, 15 patients, received plaster cast immobilization, while five patients received adjuvant foot IPC beneath the plaster cast. At 2 weeks postoperatively, microdialysis of the healing and contralateral intact Achilles tendons was followed by quantification of metabolites. Healing compared to intact tendons of the controls exhibited significantly increased concentrations (mM) of glutamate (60 ± 14 vs 20 ± 11), lactate (1.15 ± 0.60 vs 0.64 ± 0.35), and pyruvate (81 ± 29 vs 35 ± 25, µM). Healing tendons of the IPC vs control group displayed higher levels of glutamate (84 ± 15 vs 62 ± 16) and glucose (3.44 ± 0.62 vs 2.62 ± 0.72); (P < 0.05) and trends toward higher concentrations of pyruvate, lactate, and glycerol (P < 0.10). The present study demonstrates that early Achilles tendon repair entails and upregulates local essential metabolites. This metabolic response can, during tendon healing with plaster cast immobilization, be promoted by adjuvant IPC.

Deep venous thrombosis of the lower limb: no difference in duration of symptoms between proximal and distal disease.

In deep vein thrombosis (DVT) of the lower limb, the location of the thrombosis determines how great the risk of pulmonary embolism is. We set out to determine whether the duration of lower limb DVT symptoms could be a predictive factor for the location of the thrombosis. We retrospectively collected a series of 100 lower limb phlebography examinations that were positive for DVT and divided the group into 2 subgroups proximal disease (ie, above the knee) or distal disease (ie, below the knee). The subgroups were then plotted against the individual duration of the symptoms. Of the 100 DVTs, 58% were proximal, while 42% were distal. The average duration of the symptoms was 6.3 days for patients with proximal disease and 6.2 days for patients with distal disease. We, therefore, found no difference in symptom duration between patients with proximal and distal lower limb DVT. This may imply that the duration of the DVT symptoms does not represent a predictive factor for DVT-caused pulmonary embolism.

Biomechanical rupture risk assessment of abdominal aortic aneurysms: model complexity versus predictability of finite element simulations.

OBJECTIVE: Investigation of the predictability of finite element (FE) models regarding rupture risk assessment of abdominal aortic aneurysms (AAAs). MATERIALS AND MATERIALS: Peak wall stress (PWS) and peak wall rupture risk (PWRR) of ruptured (n = 20) and non-ruptured (n = 30) AAAs were predicted by four FE models of different complexities derived from computed tomography (CT) data. Two matching sub-groups of ruptured and non-ruptured aneurysms were used to investigate the usability of different FE models to discriminate amongst them. RESULTS: All FE models exhibited a strong positive correlation between PWS and PWRR with the maximum diameter. FE models, which excluded the intra-luminal thrombus (ILT) failed to discriminate between ruptured and non-ruptured aneurysms. The predictability of all applied FE models was strengthened by including wall strength data, that is, computing the PWRR. The most sophisticated FE model applied in this study predicted PWS and PWRR 1.17 (p = 0.021) and 1.43 (p = 0.016) times higher in ruptured than diameter-matched non-ruptured aneurysms, respectively. CONCLUSIONS: PWRR reinforces PWS as a biomechanical rupture risk index. The ILT has a major impact on AAA biomechanics and rupture risk, and hence, needs to be considered in meaningful FE simulations. The applied FE models, however, could not explain rupture in all analysed aneurysms.