Randomised three-armed trial investigation of the Copenhagen Achilles tendon Rupture Treatment Algorithm (CARTA) for individualised treatment of acute Achilles tendon rupture

Clinical Snapshot

Key Findings

• P Value: p=0.03 for rerupture comparison, p=0.02 for ATRS improvement

• Effect Size: Rerupture rate reduction: 73% (CARTA vs non-operative)

• Primary Outcome: No significant difference in Heel-Rise Work Test (HRWT) at 12 months between groups

• Nnt Or Sensitivity: Number needed to treat to prevent one rerupture: approximately 13 patients (based on 8% absolute risk reduction)

• Confidence Interval: CARTA rerupture: 3% (1-8%) vs non-operative: 11% (6-19%)

Clinical Application

Requires access to musculoskeletal ultrasound and trained operators. Algorithm-based decision making is straightforward to implement. Highly applicable to Australian practice. Ultrasound widely available through Medicare. Could reduce surgical waiting lists while maintaining outcomes. Aligns with value-based healthcare initiatives. Adults presenting with acute Achilles tendon rupture suitable for either operative or non-operative management

Abstract

OBJECTIVE: To evaluate whether individualised treatment using the Copenhagen Achilles Rupture Treatment Algorithm (CARTA) is superior to default operative or non-operative strategies. METHODS: We conducted a multicentre, three-arm, randomised controlled trial. Adults with acute Achilles tendon rupture were randomised (1:1:1) to individualised CARTA, non-operative or operative treatment. In the CARTA arm, surgery was indicated if ultrasound showed<25% tendon overlap or ≥7% elongation. The primary outcome was the Heel-Rise Work Test (HRWT) at 12 months. Secondary outcomes included HRWT at 6 months, and at both 6 and 12 months, the Heel-Rise Height, Achilles tendon Total Rupture Score (ATRS), Tegner activity scale, Copenhagen Achilles tendon Length Measure, Achilles Tendon Resting Angle (ATRA) and complication recordings. RESULTS: Between May 2018 and June 2023, 970 patients were screened; 300 were randomised (male/female 76%/24%, mean age 41 (SD 1)). At 12 months, data were available for 98 CARTA (64% operated), 100 non-operative and 97 operative patients. There were no significant between-group differences in HRWT at 12 months. However, CARTA significantly reduced rerupture rates by 73% compared with non-operative treatment (3% (95% CI) (1 to 8) vs 11% (6 to 19), p=0.03), improved ATRS by 8 points (1 to 15, p=0.02) and improved ATRA by -2° (-4 to -1), p=0.01). No difference between CARTA and operative treatment was found except 36% less underwent surgery. CONCLUSION: Individualised CARTA did not improve functional outcomes based on the HRWT at 12 months, but among secondary outcomes, it reduced rerupture rates and improved patient-reported outcomes compared with non-operative treatment and with fewer surgeries than routine operative care. TRIAL REGISTRATION NUMBER: NCT03525964.

References

1. 1.Toft, M., Hansen, M. S., Vestergaard, J. D., Jenlar, J., Pramming, A. K., Møller, S., Nedergaard, B. S. K., Kristensen, M. T., Simonsen, L. L., Viberg, B., Hölmich, P., & Barfod, K. W. (2026). Randomised three-armed trial investigation of the Copenhagen Achilles tendon Rupture Treatment Algorithm (CARTA) for individualised treatment of acute Achilles tendon rupture. British Journal of Sports Medicine. https://doi.org/10.1136/bjsports-2025-110210