Anterior cruciate ligament (ACL) tear is common. It accounts for over 50% of all knee injuries. Anterior cruciate ligament reconstruction (ACLR) with hamstring tendon (HT) autograft is the common graft choice for ACLR. However, the outcomes of donor site healing and recovery of muscle strength of HT are not satisfactory, resulting in hamstring muscle weakness and hamstring strength deficit during deep knee flexion, which may lead to hamstring strain after ACLR. Moreover, activation of the hamstring muscle is vital for maintaining dynamic knee joint stability and preventing excessive ACL shear forces. The presence of hamstring muscle deficits after surgery therefore affects the function of the reconstruction ACL. A previous study has reported that the hamstring muscle showed nearly 20% strength deficit at 4 months after ACLR with hamstring autograft
Pulsed electromagnetic field (PEMF) treatment is a non-invasive therapy that has been shown to enhance muscle cell activity and accelerate tissue repair. In clinic, PEMF treatment has been reported to be safe.
This study aims to conduct a double-blinded, placebo-controlled randomised clinical trial to investigate the effects of PEMF therapy for improving the tissue regeneration and strength of the HT donor site in ACLR patients with HT autograft.
Male and female with age ≥ 18 years at the time of surgery
First ACLR with HT autograft
Both knees without a history of injury/prior surgery
LSI for hamstring strength <85% of contralateral leg at 4-month isokinetic assessment (70)
Any concomitant bone fracture, major meniscus injury or full-thickness chondral injuries requiring altered rehabilitation program post-op
Preoperative radiographic signs of arthritis
Other associated injuries (fractures and other ligament involvement such as neurovascular bundles injury)
Patient with a pacemaker, an implantable defibrillator, neurosurgical clips, a neurostimulator, cochlear implant, a stent, an insulin pump
Parallel
PEMF treatment
DevicePulsed electromagnetic field (PEMF) therapy is an emerging modality for the treatment of musculoskeletal disorders. Time-varying magnetic pulses are generated by passing an electrical current through a coil. PEMF has been shown to be effective in vitro and in vivo studies for tissue repair and accelerating muscle regeneration. In each treatment, you need to put the reconstructed limb into the machine for 10 minutes.
Placebo treatment
DeviceIn this study the placebo group uses the same PEMF machine, but it does not generate any electrical current that have treatment effect. As the active PEMF device does not produce heat or cause any sensation to the tissue, participants are blinded to the treatment. In each treatment, you need to put the reconstructed limb into the machine for 10 minutes.
Isokinetic Test
The Cybex dynamometer will be used to test the hamstring muscle strength.
Isokinetic Test
The Cybex dynamometer will be used to test the hamstring muscle strength.
Isokinetic Test
The Cybex dynamometer will be used to test the hamstring muscle strength.
Click on the lead sponsor to view all of their trials.
