Compression Treatment Effects on Complications and Healing of Achilles Tendon Rupture

Study Overview
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Brief Summary
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This prospective randomized study aims to determine whether intermittent pneumatic compression (IPC), 75 patients, beneath functional bracing compared to treatment-as-usual in plaster cast, 75 patients, can reduce the Venous Thromboembolism (VTE) incidence and promote healing of sutured acute Achilles tendon ruptures. At two weeks post surgery, the IPC intervention will be ended and both patient groups will be immobilized in an orthosis until follow-up at six weeks. The endpoint of the first part of the study is VTE events. The primary outcome will be the DVT-incidence at two weeks, assessed using screening compression duplex ultrasound (CDU) by two ultrasonographers masked to the treatment allocation. Secondary outcome will be the DVT-incidence at 6 weeks. 1) Deep Vein Thrombosis (DVT) detected by CDU , 2) isolated calf muscle vein thrombosis (ICMVT) detected by CDU, 3) symptomatic DVT or ICMVT detected by CDU, 4) symptomatic pulmonary embolism detected by computer tomography. The endpoint of the second part of the study is tendon healing quantified at 2 weeks by microdialysis followed by quantification of markers for tendon repair. The endpoint of the third part of the study is the functional outcome of the patients at one year post-operatively using four reliable and valid scores, i.e. the Achilles tendon Total Rupture Score (ATRS), Physical Activity scale (PAS), Foot and Ankle Outcome Score (FAOS) and EuroQol Group's questionnaire (EQ-5D) as well as the validated heel-rise test.

Detailed Description
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The incidence of DVT after Achilles tendon rupture is as high as 30-40% and patients exhibit a prolonged healing process with variable outcome. Moreover, it has been demonstrated that low molecular weight heparin had no effect on preventing DVT after Achilles tendon surgery. Whether intermittent pneumatic compression (IPC) can prevent DVTs and improve healing after Achilles tendon rupture has to our knowledge not been tested before.

Official Title
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Intermittent Pneumatic Compression Effects on Venous Thromboembolism Incidence and Healing of Achilles Tendon Rupture

Conditions
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Rupture, Venous Thromboembolism, Venous Thrombosis, Surgical Wound Infection

Intervention / Treatment
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* Device: Intermittent pneumatic compression (IPC)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Achilles tendon rupture operated on within 96 hours of diagnose. Exclusion Criteria: Inability or refusal to give informed consent for participation in the study Ongoing treatment with anticoagulant therapy Inability to comply with the study instructions Known kidney disorder Heart failure with pitting oedema Thrombophlebitis Recent thromboembolic event (during the preceding 3 months) Recent surgery (during the preceding month) Presence of known malignancy Current bleeding disorder Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Routine care: Plaster Cast Treatment<br>Two weeks of postoperative conventional lower limb plaster cast immobilization in 30 degrees of plantarflexion | |
| Experimental: Intermittent pneumatic compression (IPC)<br>Two weeks of calf IPC by Aircast® VenaFlow® Elite System during immobilization in an orthosis Aicast® XP Walker. | Device: Intermittent pneumatic compression (IPC)<br>* 6 hours IPC, daily, applied to both calves during two weeks post-operatively. The VenaFlow Elite system (Aircast, Vista, California) uses calf cuffs containing two overlapping air chambers located posteriorly on the leg. As the device cycles, the distal chamber inflates to 52 mm Hg over half a second. During the last 0.2 second of this period, the proximal chamber inflates and reaches 45 mm Hg. After six seconds of inflation the cuff deflates, and the cycle is repeated every minute.<br>* Other names: VenaFlow® System;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Venous Thromboembolic Events (VTE) | At 2 weeks postoperatively the number of participants with VTE events will be assessed by: 1) DVT detected by compression duplex ultrasound (CDU) , 2) isolated calf muscle vein thrombosis (ICMVT) detected by CDU, 3) symptomatic DVT or ICMVT detected by CDU, 4) symptomatic pulmonary embolism detected by computer tomography. | 2 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional Outcome - Muscular Endurance Tests (Heel-rise) | The functional outcome was assessed at 1year post-operatively by the validated calf muscle endurance test, i.e. heel rise test (Silbernagel KG et al. A new measurement of heel-rise endurance with the ability to detect functional deficits in patients with Achilles tendon rupture. Knee Surg Sports Traumatol Arthrosc. 2010). The Muscle lab linear encoder (Ergotest Technology, Oslo, Norway), was used for data collection. Standardized footwear was used. Patients warmed up before testing. During the heel-rise test, verbal encouragement was used. The patient was instructed to go as high as possible on each heel-rise with a straight knee. A metronome was used for standardized frequency of 30 heel-rises per minute. The test was terminated when the patient stopped or could not maintain frequency. For analysis, the limb symmetry index (LSI, percentage of injured vs. uninjured side) values were used. | one year | 
| Venous Thromboembolic Events (VTE) | At 6 weeks postoperatively the number of participants with VTE events will be assessed by: 1) DVT detected by compression duplex ultrasound (CDU) , 2) isolated calf muscle vein thrombosis (ICMVT) detected by CDU, 3) symptomatic DVT or ICMVT detected by CDU, 4) symptomatic pulmonary embolism detected by computer tomography. | 6 weeks | 
| Patient-reported Outcome | The patients' symptoms will be assessed using the Achilles tendon Total Rupture Score (0-100, 100=best) | One year | 
| Microdialysis | At 2 weeks postoperatively in-vivo microdialysis will be performed on as described by Greve et al 2012 (DOI: 10.1111/j.1600-0838.2012.01475.x). In the microdialysate substances will be assessed, eg. markers of tendon callus production, procollagen type I (PINP), by enzymatic quantification. | 2 weeks | 
| Time From Injury to Surgery | Prognostic factor: Time to surgery , i.e. the time from ATR injury to start of the surgical procedure, will be calculated by using the time-point at which the patient sustained the injury as described in the patient journal, as well as the starting time point of the surgery as registered in the computerized operation report. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Achilles Tendon, Immobilization, Wound Healing, Intermittent Pneumatic Compression, Ultrasonography, Microdialysis