Effects of heavy slow resistance training combined with corticosteroid injections or tendon needling in patients with lateral elbow tendinopathy: a 3-arm randomized double-blinded placebo-controlled study

Key points

1. 01All three groups improved equally at 12 weeks on pain, function, and grip strength with no between-group differences
2. 02Corticosteroid injection produced an 80% reduction in tendon hypervascularization at 12 weeks, yet this did not translate into better pain or function
3. 03At 52 weeks the corticosteroid group showed a clinically significant worsening on QuickDASH score (15 points higher than placebo, P = .0427)
4. 04Tendon needling offered no advantage over placebo needling at any time point
5. 05Training compliance was high across all groups (mean 83%), suggesting the HSR program is feasible at home with elastic bands

How it was conducted

Design

3-arm randomized double-blinded placebo-controlled trial (Level of evidence 1), conducted in Copenhagen, Denmark; registered NCT02521298

Participants

58 adults (mean age 47.3 years; 53.4% female) with chronic unilateral lateral elbow tendinopathy confirmed by clinical tests and ultrasonography, symptom duration > 3 months

Groups

All received 12 weeks of home-based heavy slow resistance training with elastic bands; combined with (1) ultrasound-guided corticosteroid injection (Depo-Medrol 40 mg/mL + lidocaine), (2) tendon needling with saline, or (3) placebo subcutaneous saline injection

Primary outcome

DASH score (Disabilities of the Arm, Shoulder and Hand; 0-100) at 52 weeks

Secondary outcomes

QuickDASH, NRS pain (0-10), pain-free grip strength, and power Doppler hypervascularization area at 12, 26, and 52 weeks

Follow-up

12, 26, and 52 weeks

What they found

• All groups improved by approximately 20 points on DASH and QuickDASH and 2.5 points on NRS at 12 weeks, with no significant between-group differences (DASH at 12 weeks: CSI vs PN delta -5.07, 95% CI -15.84 to 5.70, P = .3535)
• At 52 weeks, the CSI group tended toward worse DASH scores than the PN group (delta 14.24 points, 95% CI 2.52 to 25.95, P = .0176; overall group difference P = .0581)
• QuickDASH at 52 weeks was significantly worse in the CSI group versus PN group (delta 15.08 points, 95% CI 3.23 to 26.93, P = .0131; overall P = .0427)
• NRS pain at 52 weeks tended to be higher in the CSI group versus PN group (delta 1.79, 95% CI 0.22 to 3.36, P = .0259; overall P = .0784)
• Pain-free grip strength improved in all groups at 12 weeks (P < .0001 within groups); no significant between-group difference (CSI vs PN delta 10.03 kg, 95% CI 0.16 to 19.89, P = .0466; overall P = .1351)
• Hypervascularization (power Doppler area) decreased 80% in the CSI group vs 1% in the TN group and 24% in the PN group; CSI vs PN difference was significant at 12 weeks (delta -2251 pixels, 95% CI -4416 to -87, P = .0418)
• Area under the curve for DASH over all time points did not differ between groups (P = .2174)
• Mean training compliance was 83% (269 of 324 possible sets completed) with no difference between groups (P = .65)

Limitations

• No wait-and-see control group, so natural recovery cannot be ruled out as contributing to within-group improvements
• Study may have been underpowered to detect modest differences, as the actual SD of DASH scores was slightly higher than the assumed SD of 10 used in the power calculation
• The DASH questionnaire may be relatively insensitive for lateral elbow tendinopathy; the more specific Patient-Rated Tennis Elbow Evaluation was not available in a validated Danish translation
• Blinding was imperfect: 52% in the CSI arm and 58% in the PN arm correctly guessed their allocation (expected 33% with perfect blinding)

Why it matters

For patients

Patients with chronic tennis elbow can expect meaningful improvement in pain and function from a home-based elastic band exercise program, and adding a cortisone injection is unlikely to help and may lead to worse outcomes a year later.

For clinicians

Corticosteroid injection as an adjunct to a structured heavy slow resistance program does not enhance short-term outcomes and is associated with clinically significant worsening of patient-reported function at 52 weeks, supporting caution about routine CSI use in this population.

For readers

This well-designed RCT adds to the evidence that exercise is the active ingredient in lateral elbow tendinopathy rehabilitation and that corticosteroid injections may interfere with long-term recovery even when combined with a structured loading program.