ACL Surgical Options and Implications:
Allograft (Cadaver Graft):
Advantages: quicker rehab secondary to no precautions relating to hamstring activation and no pathology to the patella-femoral joint, as seen in a patellar tendon graft. Without the trauma to your tissue as seen in an autograft, cadaver grafts are an option in general for older patients looking for a less involved rehab who are looking to continue with cutting activities.
Disadvantages: Allografts have a much higher failure rate, reported as high as near 30%. This is the primary disadvantage, although a chance of infection and higher costs also may lead patients away from allografts.
Autograft (Hamstring): Usually hamstring grafts are quadruple bundled incorporating the semi-tendinosis and gracilis tendons.
– Increased tensile strength and loser failure rates versus allografts.
– Maintenance of the patella-femoral joint is especially important in females, who have a propensity for patella-femoral problems
– Long term quad weakness is significantly less than patellar tendon grafts
– Less anterior knee pain following surgery versus patellar tendon grafts
– No hamstring activation allowed for 4-6 weeks following surgery leads to a slower time to return to running and cutting
– Increased failure rate versus patellar tendon grafts (roughly 7% failure vs. 3%)
- possibly due to altered hamstring activation, as decreased hamstring activation has been shown to correlate with ACL tears
– weakness to hamstrings is present 5 years post reconstruction
– Increased graft strength versus allografts and autografts
- Results in the lowest incidence of failure rates amongst the graft options
- Increased healing as graft is bone-patellar tendon-bone, resulting in bone to bone healing which likely results in improved healing times
– Long-term hamstring weakness significantly less than hamstring grafts
– Can activate hamstrings immediately as well as quads
- Quicker return to running versus hamstring grafts
– Increased rate of anterior knee pain versus other graft types
– Alters patella-femoral mechanics as middle 1/3 of patellar tendon is used as a graft
– Increased quad weakness long term relative to other graft options
Autograft (contralateral): A less popular option, used most commonly in Indianapolis by Dr. Donald Shelbourne, a contralateral graft avoids the trauma and altered mechanics that coincide with a graft from the same limb.
– Do not have morbidity to the graft site on the reconstructed knee, allowing for a quicker rehab while maintaining improved graft strength and healing times versus allografts
- Strength maintained in hamstrings and quads versus other autograft options
– Few surgeons do this procedure
– No statistical difference in failure rates
– Have to rehab the donor knee (contralateral site) as the graft site morditity is on the opposite leg – PT will have precautions on the donor side as well as the reconstruction side
Conclusion: There are various options for reconstruction following an ACL tear. In general, younger more active patients are likely best off with an autograft, as the risk of graft failure is up to 4x less. Hmastring grafts may allow for decreased risk of patellar-femoral problems, but research seems to indicate that failure rates are higher than patellar grafts. Ultimately, the decision of graft choice should be chosen cooperatively with the patient and surgeon taking into effect age