Brace-free rehabilitation after isolated anterior cruciate ligament reconstruction

Key points

1. 01Non-inferiority was confirmed on the primary outcome (subjective IKDC score) with a mixed-effects regression coefficient of 1.57 (95% CI -2.56 to 5.70, p < 0.0001 for non-inferiority)
2. 02Knee laxity, isokinetic muscle strength, Lysholm score, Tegner activity scale, and quality of life were all non-inferior in the brace-free group
3. 03Objective IKDC grades improved faster in the brace-free group in the early months
4. 04Both groups reported ACL-RSI scores above the 56-point readiness-to-return-to-sport threshold at 12 months (brace-free 70.4 +/- 23.3, brace-based 72.5 +/- 20.4)
5. 05Eliminating braces could save the German healthcare system up to 22.9 million EUR annually based on estimated ACL incidence rates

How it was conducted

Design

Single-centre prospective randomised controlled non-inferiority trial with parallel-group 1:1 allocation

Participants

114 adults (mean age 32.4 +/- 11.5 years, 35.1% women) with primary ACL rupture undergoing isolated ACLR with ipsilateral hamstring tendon autograft

Groups

Brace-based (n = 58): four-point hard-frame knee brace for 6 weeks postoperatively; Brace-free (n = 56): no external stabilizer

Primary outcome

Subjective IKDC score at 12 months postoperatively

Secondary outcomes

Objective IKDC, knee laxity (KLT), isokinetic strength, Lysholm score, Tegner activity scale, ACL-RSI, and SF-36 quality of life

Follow-up

Preoperative baseline, then 6 weeks, 4 months, 6 months, and 12 months

What they found

• Primary outcome: mixed-effects regression coefficient 1.57 (95% CI -2.56 to 5.70), p for non-inferiority < 0.0001; non-inferiority margin was 9.0 IKDC points
• Lysholm score at 12 months: brace-based 88 +/- 4.0, brace-free 85 +/- 3.9; non-inferiority coefficient 0.37 (95% CI -6.12 to 5.38, p < 0.0001)
• Knee laxity non-inferiority: mixed-effects regression coefficient 0.64 (95% CI -0.01 to 1.28, p < 0.0001)
• Tegner activity scale at 12 months: brace-based 5.5 +/- 0.5, brace-free 5.3 +/- 0.6; non-inferiority coefficient -0.055 (95% CI -0.59 to 0.70, p < 0.0001)
• SF-36 physical component non-inferiority coefficient -0.258 (95% CI -4.40 to 3.89, p < 0.0001); mental component coefficient 3.80 (95% CI -1.57 to 9.17, p < 0.0001)
• Isokinetic knee extension non-inferiority coefficient 0.0199 (95% CI -0.196 to 0.2361, p < 0.0001); knee flexion -0.0458 (95% CI -0.1505 to 0.059, p < 0.0001)
• ACL-RSI at 12 months: brace-free 70.4 +/- 23.3, brace-based 72.5 +/- 20.4; both above the 56-point return-to-sport threshold

Limitations

• Patients requiring meniscal repair or reconstruction were excluded, limiting applicability to combined ACLR procedures
• Follow-up was only 12 months, so long-term durability of outcomes cannot be assessed
• Single-centre design may limit generalisability
• Male predominance (approximately 64-66% per group) may not reflect ACL injury patterns in female athletes

Why it matters

For patients

Patients recovering from isolated ACL reconstruction with a hamstring graft can expect the same functional recovery and return to sport whether or not they wear a knee brace for the first 6 weeks after surgery.

For clinicians

This Level I RCT provides strong evidence to justify omitting rehabilitative knee bracing after isolated hamstring tendon ACLR, simplifying post-operative protocols and reducing costs without compromising objective or subjective outcomes.

For readers

The study fills an important evidence gap by being the first RCT to test truly brace-free (no alternative stabilizer) rehabilitation after hamstring tendon ACLR, confirming that bracing is not necessary in this specific surgical context.