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