A Randomised Controlled Study Protocol on the Maxm Skate; A Lower Limb Rehabilitation Device for use following Total Knee Arthroplasty

BACKGROUND: Following Total Knee Arthroplasty (TKA) patients experience lower extremity muscle weakness and commonly require physical rehabilitation to enhance functional outcomes and overall recovery.(1) In Australia, there are recognised variations in rehabilitative care following TKA, however rehabilitation most commonly provided is in an outpatient setting, on a one-to-one treatment basis.(2) Outpatient physiotherapy is beneficial as the physiotherapist can monitor progress and modify therapy, however such methods are resource- intensive and impose a significant cost burden.(1) The number of TKA procedures is rising, bringing concern of the sustainability and economic impact of one-to-one rehabilitation. Further research is needed to determine whether outpatient physiotherapy yields superior outcomes compared to less-costly alternatives such as group or home-based rehabilitation. The Maxm skate is a portable, lower limb post-operative and post-injury rehabilitation exercise device for individual use in a hospital or home-based setting. The Skate intends to facilitate rehabilitation and conditioning through graded therapeutic exercises and minimal joint loading. Study investigators aim to conduct a randomised controlled trial (RCT) to compare the safety, efficacy and cost-effectiveness of the Maxm Skate rehabilitation device to standard rehabilitative care. The primary outcome is to assess the range of motion (ROM) achieved by patients whom received the Maxm Skate device compared with standard care, 3 months postoperatively. METHODS: This is a study protocol for an open-label RCT, in which 116 participants will be randomly allocated to an interventional or control group. A total of 58 participants per group will provide 90.0% power (α=0.05) to detect 10 degrees of difference (SD=16) in ROM, at 3 months post TKA. Participants assigned to the interventional group will receive the Maxm Skate in addition to standard care in the in-patient setting. Following discharge, participants will be asked to limit physiotherapy to Skate use only, and compliance will be documented. Outcomes will be compared to those receiving standard rehabilitative care. A blinded physiotherapist will evaluate functional outcomes preoperatively and at 2, 4, 6, 12, 26 and 52 weeks post TKA. The functional assessment will include measures of knee ROM, pain, isometric knee strength, balance, and knee/thigh circumference. Limited measures will also be assessed at Day 2 postoperatively by an alternate, un-blinded physiotherapist. Clinical and patient-reported outcome measures will be administered preoperatively, and at 6, 12 and 52 weeks postoperatively. An economic evaluation assessing the relative cost-effectiveness of the Maxm Skate rehabilitation device, compared to standard care, will be conducted. Patients will also be screened for adverse event occurrences and complications from the time of consent to 1 year postoperatively. DISCUSSION: This clinical trial is the first developed to assess the efficacy of the Maxm Skate on patient’s rehabilitation following TKA. TRIAL REGISTRATION: ACTRN: ACTRN12616001081404p REFERENCES: (1) Pozzi F, Snyder-Mackler L, Zeni J. Physical exercise after knee arthroplasty: a systematic review of controlled trials. Euro J Phys Rehabil Med. 2013;49(6):877-92. (2) Naylor J, Harmer A, Fransen M, Crosbie J, Innes L. Status of physiotherapy rehabilitation after total knee replacement in Australia. Physiother Res Int. 2006;11(1):35-47.