A Comparison of Neuromuscular Electrical Stimulation Parameters for Postoperative Quadriceps Strength in Patients After Knee Surgery: A Systematic Review

Conley CEW, Mattacola CG, Jochimsen KN, Dressler EV, Lattermann C, Howard JS · Sports Health

Effects on quadriceps strength ranged from Hedge's g of -0.37 (95% CI -1.00 to 0.25) to 1.13 (95% CI 0.49 to 1.77) — that is, from slightly against stimulation to strongly for it. The authors grade the evidence B and recommend, from the parameters used by the trials that worked, stimulation in the first two postoperative weeks at 50 Hz or above, maximum tolerable intensity, biphasic current, large electrodes and a 1:2 to 1:3 duty cycle with a two- to three-second ramp.

Population

Eight randomised trials of neuromuscular electrical stimulation after knee surgery — ligament reconstruction, knee replacement and meniscectomy — with a mean PEDro score of 5 out of 10

Intervention

Neuromuscular electrical stimulation, compared across the treatment parameters each trial used

Comparator

Rehabilitation without stimulation

Limitations

The parameter recommendation is drawn from which trials happened to show the largest effects, not from any trial that randomised a parameter, so it is a description of the successful protocols rather than evidence that those settings caused the success. Trials applying stimulation alongside another modality were excluded. Searched only to December 2018 and the included trials are mostly low quality. Two authors declare conflicts: an institutional grant from the International Cartilage Regeneration and Joint Preservation Society registry, and a paid consultancy with Joint Restoration Foundation, Samumed and Vericel.