Incidence and Outcome after Revision
Anterior Cruciate Ligament Reconstruction: Results from the Danish Registry for
Knee Ligament Reconstruction.

Lind M,
Menhert F, and Redersen AB. Am J Sports Med. 2012;40:1551-57.

following anterior cruciate ligament (ACL) reconstruction is becoming
increasingly prevalent, especially in the physically active population. Unfortunately,
it is unclear how common ACL revision (ACL-rev) surgeries are, how patients
perform after an ACL-rev, and what patient characteristics are related to an
increase risk of ACL-rev. Therefore, Lind and colleagues utilized the Danish national
ACL reconstruction registry to identify: (a) the epidemiology and risk factors
for ACL-rev surgery after primary ACL reconstruction, (b) the rate of
re-revision ACL reconstruction after ACL-rev, and (c) patient characteristics
and clinical outcomes after ACL-rev reconstruction compared to clinical
outcomes after primary ACL reconstruction. The Danish national ACL
reconstruction registry is a nationwide, prospective web-based registry
containing data on primary and ACL-rev reconstructions from 51 hospitals. The
registry includes preoperative and operative objective data recorded by the physician
and in some cases 1-year follow-up data with both subjective and objective
measurements. A cohort of 1099 ACL-rev cases were identified from initial
12,193 primary ACL reconstruction procedures performed between July 1, 2005 and
December 31, 2010. The authors extracted the patient’s age, gender, and cause
of injury, as well as Knee Injury and
Osteoarthritis Outcome Score (KOOS)
, and Tegner
functional score
at 1 year post-reconstruction. Overall, more male patients
had ACL-rev surgeries (54%) compared to female patients (46%; a
recent study based on this registry suggested that males have a higher
incidence of cruciate injuries
). Furthermore, primary ACL reconstruction
occurred most frequently in the 30+ age group, however of that group, the
majority of ACL-rev occurred in a younger age group (15-20 years olds). Overall,
4.7% of ACL reconstructions were later followed up by an ACL-rev which
typically occurred 1.8 years after the primary reconstruction. The most common
cause for graft failure was “new trauma” (n = 419, 38%). Of that group, 83% of
“new trauma” was caused by participation in sports. Subjectively, KOOS and
Tegner scores were significantly lower 1 year after ACL-rev than after primary
ACL reconstruction. Furthermore, there was weak evidence that side-to-side
laxity measurements were greater (1.9 mm) in ACL-rev patients than primary
reconstruction patients (1.5 mm). Overall, patient sex and cause of the primary
ACL rupture were not significant factors in reinjury. Finally, the 5-year
re-revision rate was 5.4% and allograft tissue used in an ACL-rev had twice the
risk of requiring a re-revision compared to autograft tissues.

These data are
an interesting look at the risk of reinjury after primary ACL reconstruction. The
authors reported that neither sex nor primary cause of rupture is an indicator
of potential re-injury in the future. Instead, clinicians should be aware that
the patients, who have the greatest risk of reinjury, are patients between 1
and 2 year after primary ACL reconstruction. Furthermore, in this time period,
special care should be paid to those participating in sporting activities.
While this information may be helpful in understanding the risks of reinjury,
caution should be exercised when interpreting some of this data. Of all 1099 patients
with ACL-rev included in this study, none underwent a double-bundle graft procedure.
This fact questions how valuable this information may be. Is there a gold-standard
ACL-rev technique? It would be interesting to see more detailed information
regarding common techniques or complications of ACL-rev surgery. Tell us what
you think. How would you find this data useful in your everyday practice? What
are your experiences with patients who undergo ACL-rev surgery?

Written by: Kyle
Reviewed by: Jeffrey Driban

Lind M, Menhert F, & Pedersen AB (2012). Incidence and outcome after revision anterior cruciate ligament reconstruction: results from the danish registry for knee ligament reconstructions. The American Journal of Sports Medicine, 40 (7), 1551-7 PMID: 22562791