Comparison of intra-articular hyaluronic acid injections with transcutaneous electric nerve stimulation for the management of knee osteoarthritis: a randomized controlled trial.

OBJECTIVE

To compare the effects of intra-articular hyaluronic acid (HA; ARTZ) and transcutaneous electric nerve stimulation (TENS) in the treatment of patients with knee osteoarthritis.

DESIGN

A prospective, randomized controlled trial.

SETTING

Rehabilitation clinic of a teaching hospital.

PARTICIPANTS

Patients with knee osteoarthritis (N=50; aged 51-80y) were randomly assigned to the HA group (n=27) or the TENS group (n=23).

INTERVENTIONS

The HA group received intra-articular HA injection into the affected knee once a week for 5 consecutive weeks, and the TENS group received a 20- minute session of TENS 3 times a week for 4 consecutive weeks.

MAIN OUTCOME MEASURES

The primary outcome measures used were the visual analog scale (VAS) for pain and the Lequesne index. The secondary outcome measures were range of motion of the knee, walking time, pain threshold, patient global assessment, and disability in activities of daily living. All subjects were assessed at baseline, and at 2 weeks, 2 months, and 3 months after the treatments were completed.

RESULTS

The TENS group exhibited a significantly greater improvement in VAS than the HA group at 2 weeks' follow-up (4.17 ± 1.98 vs 5.31 ± 1.78, respectively; P=.03). In addition, the TENS group also exhibited a significantly greater improvement in the Lequesne index than the HA group at 2 weeks' follow-up (7.78 ± 2.08 vs 9.85 ± 3.54, respectively; P=.01) and at 3 months' follow-up (7.07 ± 2.85 vs 9.24 ± 4.04, respectively; P=.03).

CONCLUSIONS

TENS with silver spike point electrodes was observed to be more effective than intra-articular HA injection for patients with knee osteoarthritis in improving the VAS for pain at 2 weeks' follow-up as well as the Lequesne index at 2 weeks' and 3 months' follow-up.