What did the study look at?
The authors note that ACL injuries, reconstructions and re-ruptures have increased rapidly, and that outcomes after a failed ACL reconstruction have been reported to be far worse than after a primary reconstruction. Revision can be done in one stage or two; a two-stage approach is preferred when there is significant bone loss, previously malpositioned tunnels or unacceptable tunnel widening.
The article sets out to show how the authors perform the first stage of this approach, tunnel debridement and bone grafting, augmented with bone marrow aspirate concentrate (BMAC). They state that BMAC contains a high concentration of mesenchymal stem cells, progenitor cells and growth factors, and that recent literature has shown it may improve clinical outcomes and graft integration.
How was it done?
The article is a video technique presentation built around a single patient: an active 46-year-old man. Four years earlier he had a primary ACL reconstruction of the right knee using an allograft (donor tissue); after that graft re-ruptured, he had a revision with his own tissue (autograft) one year before presentation. After a squat during an intense strength-training session, his pain, swelling and sense of instability returned.
Computed tomography showed marked tunnel enlargement, with a maximum diameter of 18 mm in the shin bone (tibia) and 21 mm in the thigh bone (femur). MRI confirmed that the graft had torn again. Given the extent of tunnel widening, the team chose a two-stage revision. The main steps of the first stage were:
- Bone marrow aspiration from the upper tibia.
- Removal of the old screws, the torn graft remnants, and fibrous tissue and sclerotic bone from the tunnels.
- Mixing demineralised bone matrix with the prepared BMAC and injecting it into the femoral tunnel.
- Placing a 12-mm cannulated allograft bone dowel in the tibial tunnel and filling the remaining gap with the same mixture.
What did it find?
After surgery, weight-bearing was restricted for 6 weeks. Graft incorporation is followed with serial X-rays, and a CT scan may be obtained before proceeding to the second stage at roughly 4 to 6 months. The initial postoperative X-rays were reported to show good tunnel fill with no lucency or complication.
The abstract adds, based on the literature, that patients are expected to have better knee-specific quality of life, less pain and a return to activities within 2 years, and that no differences in outcomes have been reported between one-stage and two-stage revisions. These are general expectations cited by the authors, not long-term results for this patient.
The authors' conclusion
The authors conclude that recent advances in understanding the effects of BMAC in ACL reconstruction should prompt surgeons to consider such treatment in suitable patients.
Limitations
The authors state that the decision to perform a staged revision remains controversial and that there is no consensus on the best bone graft source for tunnel grafting. In addition, this publication is a technique description based on a single case and does not report the outcome of the second stage or longer-term results.
Reference
Vadhera AS, Wolfson TS, Lee JS, Singh H, Gürsoy S, Verma NN, Chahla J. (2023). Bone Marrow Aspirate Concentrate With Two-Staged-Revision ACL Reconstruction. Video Journal of Sports Medicine, 3(2), 26350254221149451. Licence: CC BY-NC-ND 4.0.
DOI: 10.1177/26350254221149451
Free full text: PMC11931519
This article summarises a published scientific paper for general information; it does not replace an examination or a personal medical assessment. Please consult your doctor about your symptoms.
