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.
Re-injury 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 Harris
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