ACL repair with internal bracing effective option to ACL reconstruction for acute proximal tears

Anterior cruciate ligament (ACL) reconstruction is currently the gold standard surgical treatment for ACL tears but has variable success rates in term of patient satisfaction and revision rates of around 10-15%.

Primary repair of ACL ruptures has re-emerged as a treatment option for proximal tears, with internal brace augmentation often utilised. Theoretically, this technique could restore normal patient anatomy, retaining proprioceptive fibres, whilst not causing donor site morbidity.

Three main ACL repair techniques have been developed aiming to improve the mechanical environment - Bridge Enhanced ACL Repair (BEAR), Dynamic Intraligamentary Stabilisation (DIS) and internal brace ligament augmentation (IBLA).

BEAR is a biologically enhanced scaffold used to treat midsubstance tears. Internal bracing is the augmentation of a ligament repair with high strength suture tape, which reinforces the ligament and acts as a secondary stabiliser. This promotes natural healing of the repaired proximal ACL tear by protecting it from excessive elongation during the early healing stages.

A literature search was performed in accordance with Preferred Reporting Items for Systematic Reviews and Metaanalyses (PRISMA) guidelines. All studies reporting outcomes of arthroscopic primary repair of proximal ACL tears, augmented with internal bracing from 2014-2021 were included. Primary outcome was failure rate and secondary outcomes were subjective patient reported outcome measures (PROMs) and objective assessment of anteroposterior knee laxity.

Key findings of the study:

• Nine studies were included, consisting of 347 patients, mean age 32.5 years, mean minimum follow up 2 years.

• There were 36 failures (10.4%, CI 7.4% - 14.1%).

• PROMs reporting was variable across studies.

• KOOS, Lysholm and IKDC scores were most frequently used with mean scores > 87%.

• The mean Tegner and Marx scores at follow-up were 6.1 and 7.8 respectively.

• The mean side to side difference measured for anteroposterior knee laxity was 1.2mm.

The authors concluded that – “This systematic review with meta-analysis shows that ACL repair with internal bracing is a safe technique for treatment of proximal ruptures, with a failure rate of 10.4%. Subjective scores and clinical laxity testing also revealed satisfactory results. This suggests that ACL repair with internal bracing should be considered as an alternative to ACL reconstruction in suitable cases, with the potential benefits of retained proprioception, as well as negating the need for graft harvest.”

Further reading:

Anterior cruciate ligament repair with internal brace augmentation: A systematic review

W.T. Wilson, G.P. Hopper et al

The Knee 35 (2022) 192–200

https://doi.org/10.1016/j.knee.2022.03.009