Sports Medicine Research: In the Lab & In the Field: Patellar Autograft May be Better to Avoid Revision (Sports Med Res)


Wednesday, November 12, 2014

Patellar Autograft May be Better to Avoid Revision

Lower Risk of Revision With Patellar Tendon Autografts Compared to Hamstring Autografts

Gifstad T, Foss OA, Engebretsen L, Lind M, Forssblad M, Albrektsen G, Drogset JO. American Journal of Sports Medicine. 2014. 42(10):2319-2328. doi: 10.1177/03635465148164

Take Home Message:  A patient with a patellar autograft for anterior cruciate ligament (ACL) reconstruction has less of a chance of a need for ACL revision surgery than patients receiving a hamstring autograft. 

Despite extensive research, debate continues regarding the influence of primary ACL reconstruction graft choice on patient outcomes.  Current AAOS guidelines indicate that selection of either a hamstring or a patellar autograft yields similar enough results that either could be considered.  Many smaller caveats may need to be individually considered. For instance, in a recent study reviewed by Sports Med Res, patients with patellar tendon autografts may be more likely to have a positive pivot-shift, knee osteoarthritis, and lower functional outcome scores than those with a hamstring autograft but they may also have a lower risk of infection. We also recently reported on two studies that indicated that patients with patellar tendon autografts are less likely to require a revision surgery than those with a hamstring autograft but given the relatively uncommon need for revision surgery, it would be helpful to see more studies confirm or refute these findings.  The authors of this Scandinavian registry study aimed to determine whether graft choice effects revision risk. From 2004 to 2011, nearly 46,000 ACL reconstructions were performed in Sweden, Denmark, and Norway. Hamstring autograft was the most common graft choice (84%) and about 14% of the reconstructions were done utilizing a patellar tendon autograft. Approximately 1200 revisions were necessary (156 in patellar tendon group, 1042 in hamstring group) and the patellar tendon group had a lower risk of revision than the hamstring group.  The authors estimate that 2.8% of patellar tendon and 4.2% of hamstring autograft ACL reconstructions would have had ACL revision five years post primary ACL reconstruction.  Due to the very large sample size, the authors were able to conduct subanalyses to further investigate the influence of graft selection within different aged groups, sport type, and coexisting injuries.  In all of these subsets the authors confirmed that individuals with a patellar tendon autograft had a reduced risk for revision compared with those who had a hamstring autograft. 

This study supports the two prior studies that indicated that a patient with a patellar tendon autograft seems to have a lower risk for ACL revision.  Interestingly, the hamstring autograft was the overwhelming choice (84%) by surgeons in Scandinavia and from 2004 to 2011, and there was an even greater shift towards the selection of hamstring autograft as the study progressed.  Within different areas of the world, graft selection varies.  For example, the authors report the following from previous research: US study where there were 25% patellar tendon autografts, 31% hamstring autografts, & 42% allografts; a Canadian study where there were 90% autografts and 5% allografts; and a UK study where 58% were patellar tendon autograft, 37% were hamstring autograft, & less than 1% were allograft.  As a medical community there appears to be surgical technique decisions made based more on tradition and availability of materials as opposed to outcomes evidence that exists.  ACL revision risk is extremely low, but still present in both the hamstring and patellar autograft groups.  While patellar autografts seem to have a lower revision risk, there are still other functional issues to consider as well as the higher rate of osteoarthritis.  Patients within this registry are followed up with at 1, 3, and 5 years post surgery; it would be of further interest to continue to follow these patients out longer to determine if there are any disparities in their long-term outcomes.  It may be that ACL graft selection needs to be determined on an individual basis.  Future research should focus on identifying variables to help predict both short-term and long-term success of graft selection within patient cohorts. In the meantime, this study provides us with more evidence to discuss with our patients when we discuss graft options.       

Questions for Discussion:  What types of grafts are you seeing used the most?  Anecdotally, are there any grafts that you feel work better for short-term or long-term outcomes?

Written by: Nicole Cattano
Reviewed by: Jeffrey Driban

Related Post:
ACL Autograft Selection Revisited

Gifstad, T., Foss, O., Engebretsen, L., Lind, M., Forssblad, M., Albrektsen, G., & Drogset, J. (2014). Lower Risk of Revision With Patellar Tendon Autografts Compared With Hamstring Autografts: A Registry Study Based on 45,998 Primary ACL Reconstructions in Scandinavia The American Journal of Sports Medicine, 42 (10), 2319-2328 DOI: 10.1177/0363546514548164


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