Adding supervised eccentric quadriceps training after knee replacement improved function scores

Design

Randomised controlled trial, intention-to-treat

Population

44 patients having primary total knee arthroplasty

Primary outcome

WOMAC total and Knee Society functional scores over 8 weeks

Effect

Group-by-time interaction P < 0.001 for both, favouring eccentric training; VAS difference at 8 weeks -0.30 (95% CI -0.69 to 0.08)

In this randomised trial, 44 patients having primary total knee arthroplasty were assigned to supervised eccentric-concentric quadriceps training on an isokinetic dynamometer or to closed-chain functional exercises without it. Both ran for 8 weeks, five sessions weekly from one week after surgery, with matched session time.

The eccentric group improved more on the Knee Society functional score and WOMAC total score (group-by-time interaction P < 0.001 for each), and on active extension (P = 0.006). Pain showed a different trajectory (P = 0.011), but the difference in VAS at 8 weeks was -0.30 (95% CI -0.69 to 0.08), not significant. Knee Society joint score, passive motion and flexion did not differ.

The sample is small, an isokinetic dynamometer is not available everywhere, and the follow-up ended at 8 weeks. Where equipment exists, adding eccentric work is reasonable. It should not displace standard rehabilitation.

• Consider adding supervised eccentric quadriceps work to standard rehabilitation after knee replacement where a physiotherapist can deliver it.
• Expect gains in function scores and active extension, not necessarily in pain at 8 weeks.
• Start from about one week after surgery, as in the trial, within your surgeon's protocol.
• Without an isokinetic machine, ask your physiotherapist about eccentric loading with available equipment; the trial did not test that.
• Measure WOMAC or KSS before and after so you can see the effect in your own patients.

Why it matters

Rehabilitation content after arthroplasty is often generic, and this points to a specific component worth testing.

Don't overread it

A 44-patient trial with 8 weeks of follow-up does not show lasting benefit or that the gains are large enough to matter to patients.

The statistics, in plain English

A significant group-by-time interaction means the groups' scores changed differently over the 8 weeks, which does not tell you the size of the gap at the end. For pain, the end-of-trial gap included zero (-0.69 to 0.08), so the pain benefit is not established.

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