Compression Treatment Effects on Complications and Healing of Achilles Tendon Rupture

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

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.

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.

Achilles Tendon, Immobilization, Wound Healing, Intermittent Pneumatic Compression, Ultrasonography, Microdialysis

Two weeks of postoperative conventional lower limb plaster cast immobilization in 30 degrees of plantarflexion

Two weeks of calf IPC by Aircast® VenaFlow® Elite System during immobilization in an orthosis Aicast® XP Walker.

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.

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.

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.

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.

The patients' symptoms will be assessed using the Achilles tendon Total Rupture Score (0-100, 100=best)

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.

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.

Prognostic factor: All patients are operated on according to a standardized surgical protocol. and the surgeon on duty will perform the surgical repair and no specific surgeon can be selected by the patients. Unknown sex of the operating surgeon will be included as an additional exclusion criterion in the study.

Prognostic factor: All patients are operated on according to a standardized surgical protocol. and the surgeon on duty will perform the surgical repair and no specific surgeon can be selected by the patients. The experienced group of surgeons will consist of specialists accredited with a specialist licence issued by The Swedish National Board of Health and Welfare. The less experienced group of surgeons will consist of residents.

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

Starting 12 months after publication the data will be available for 10 years after the study is published.

Domeij-Arverud E, Labruto F, Latifi A, Nilsson G, Edman G, Ackermann PW. 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. Bone Joint J. 2015 May;97-B(5):675-80. doi: 10.1302/0301-620X.97B5.34581.

Abdul Alim M, Domeij-Arverud E, Nilsson G, Edman G, Ackermann PW. Achilles tendon rupture healing is enhanced by intermittent pneumatic compression upregulating collagen type I synthesis. Knee Surg Sports Traumatol Arthrosc. 2018 Jul;26(7):2021-2029. doi: 10.1007/s00167-017-4621-8. Epub 2017 Jul 1.

Chen J, Wang J, Hart DA, Ahmed AS, Ackermann PW. Complement factor D as a predictor of Achilles tendon healing and long-term patient outcomes. FASEB J. 2022 Jun;36(6):e22365. doi: 10.1096/fj.202200200RR.

Svedman S, Juthberg R, Edman G, Ackermann PW. Reduced Time to Surgery Improves Patient-Reported Outcome After Achilles Tendon Rupture. Am J Sports Med. 2018 Oct;46(12):2929-2934. doi: 10.1177/0363546518793655. Epub 2018 Aug 31.

Alim MA, Svedman S, Edman G, Ackermann PW. Procollagen markers in microdialysate can predict patient outcome after Achilles tendon rupture. BMJ Open Sport Exerc Med. 2016 Jun 10;2(1):e000114. doi: 10.1136/bmjsem-2016-000114. eCollection 2016.