Summary

ACLR with internal bracing may have its utility as a bailout when faced with <=8mm hamstring graft diameter

Abstract

Background

Anterior cruciate ligament reconstruction (ACLR) using hamstring autograft of <=8mm diameter is known to be associated with poor outcomes, instability, and graft rupture. In such circumstances, use of internal bracing may help as a bailout. We set out to study the survivorship and functional outcomes in patients managed with internal brace augmentation (IBA) of hamstring autograft using suture-tape for the construct diameter <=8mm. Any untoward outcome due to the presence of foreign material that could lead to failure of construct or joint damage was recorded.

Method

This ongoing prospective study was conducted in patients who underwent ACLR using IBA with hamstring autograft <=8 mm diameter between January 2019 & January 2024. Assessments were done pre-procedure and subsequently at 6 weeks, 3 months, 6 months, 1 year, 2 year and 5 year post-procedure. At each review, they underwent clinical examination (swelling, joint line tenderness, redness, deformity, Lachman test, anterior drawer test, pivot shift), objective functional assessment (single leg hop, triple leg hop, triple cross over hop, drop jump test), pain assessment using visual analogue scale (VAS) and assessment for any foreign body reaction. The functional recovery was evaluated by International Knee Documentation Committee (IKDC) score, Lysholm score (LS) & Tegner activity scale (TAS). Radiological imaging (X-ray and MRI) was performed annually.
RESULT
Twenty-five patients underwent ACLR with IBA. Average time between injury and surgery was 2.5 months. The femoral graft diameter was 6.5mm in 9 patients, 7mm in 9 patients, 7.5 mm in 4 patients and 8mm in 3 patients. Pre-operatively, all patients presented with complaints of instability and pain, along with positive clinical and objective functional tests. The pre-operative mean VAS (0-10), IKDC (0-100), LS (0-100) and TAS (0-10) were 5±2, 39±11, 52±18 and 1±1 respectively.
There were 20 patients who had completed one year assessment with negative clinical and objective functional tests. Their mean VAS, IKDC, LS and TAS were 0.8±0.6, 93±4.5, 96±3.7 and 5.6±1 respectively. This showed significant improvement from pre-operative state (p<0.001). Similarly, 13 patients had completed their second year follow-up assessment by June 2024, with negative clinical signs and objective functional tests. Their mean VAS, IKDC, LS and TAS were 0.5±0.5, 94±4, 99±2 and 5.9±1 reflecting maintained improvement compared to their 1 year follow-up (p>0.05).
Five-year follow-up was completed by one patient. He had negative clinical signs and objective functional tests. His functional recovery scores were 0, 94, 100 and 5 respectively. One patient underwent revision surgery after 6 months due to infection. No other patient reported any untoward incident. Annual radiological assessments showed intact graft with no foreign body reaction in any patient.

Conclusion

ACLR with IBA demonstrated good outcome with return to pre-injury activity with no re-rupture, foreign body reaction or untoward side effects on clinical, functional and radiological evaluations at all follow-ups. The technique may have its utility as a bailout solution when faced with <=8mm hamstring graft diameter.