Sports Medicine Research: In the Lab & In the Field: Limited Effectiveness of ACL Reconstruction with Remnant Preservation (Sports Med Res)


Thursday, January 3, 2013

Limited Effectiveness of ACL Reconstruction with Remnant Preservation

Anterior cruciate ligament reconstruction with remnant preservation: a prospective, randomized controlled study.

Hong L, Li X, Zhang H, Liu X, Zhang J, Wei Shen J, and Feng H. Am J Sports Med. 2012;40:2747-2755.

Recent claims suggest that a surgical procedure, which uses the remnant of the ruptured anterior cruciate ligament (ACL), would be beneficial to the long-term outcome of patients with an ACL rupture. Therefore, Hong and colleagues completed a randomized controlled trial to compare the short-term clinical outcome of remnant-preservingACL reconstruction (ACLR) to the standard ACLR. Patients were included if (a) there was a complete ACL injury, (b) the tibial insertion of the ACL remnant was intact, and (c) arthroscopy confirmed that the remaining ACL length and diameter were adequate to perform the remnant-preserving procedure. Patients were excluded if (a) a bilateral knee injury was sustained; (b) there was a concurrent posterior cruciate ligament injury, posterolateral corner injury, or grade III medial collateral ligament injury; (c) total meniscectomy, and (d) history of knee surgery. From 525 consecutive patients, the authors excluded 435 patients. The remaining patients were randomly assigned to either the remnant-preserving ACLR group (45 patients) or the standard ACLR group (45 patients). Both groups underwent testing (Lachman test, pivot-shift test, and KT-1000 arthrometer) under anesthesia, as well as a single-bundle ACLR technique with 4-strand allografts. Patients in the remnant-preserving group had the allograft sutured to the remnant of the native ACL (moredetailed description available in Ahn JH et al 2009). Following surgery, all patients followed the same rehabilitation protocol and were reevaluated using Lysholm and International Knee Documentation Committee grading systems at 3, 6, 9, 12, 18, and 24 month post-surgery. Clinical evaluations were completed preoperatively and at least 2 years post-surgery. The authors used a Biodex detector to assess knee proprioception (specifically, passive angle reproduction test with a target angle of 15 degrees). Final analysis showed that ACLR with remnant-preservation was not superior to ACLR without remnant-preservation with respect to all variables. While there were no differences in clinical scores, physical examination, or proprioception the ACLR with remnant-preservation required a longer tourniquet time (~90 minutes vs ~75 minutes) compared to the standard ACLR.

Overall, this study provides some interesting data indicating that ACLR with remnant-preservation is not superior to a single-bundle ACLR without remnant preservation. While this data can be applied clinically, one must be careful when attempting to identify a “gold standard” of ACLR.  In this study both groups underwent a single-bundle ACLR procedure but research has suggested that the double-bundle ACLR technique is superior to the single-bundle procedure in terms of patient’s outcome. Therefore, it would be beneficial to compare the remnant-preserving technique to a double-bundle technique to truly assess patient outcomes. Further, one should be cautious when evaluating the applicability to a certain population. In this study over 80% of initially considered patients were not eligible. The sample they included should represent an optimal population for the procedure but they still found no differences between groups. It should also be noted that the remnant -preserving technique has not been studied with regards to early onset osteoarthritis. While the data should be interpreted cautiously, the applicability of the study is admirable. These findings, despite the limitations noted above, suggest that the overall outcomes are not affected by the status of the ACL remnant; therefore, clinicians can consider this in terms of return to play in the short-term. If a patient is considering finishing a season with an ACL deficient knee then clinicians can rest assured that the remnant of the injured ACL is of no concern to the overall outcome following surgery. Tell us what you think. Have you had patients who have undergone this ACLR with remnant preservation? If so, what was your experience with the procedure?

Written by: Kyle Harris
Hong L, Li X, Zhang H, Liu X, Zhang J, Shen JW, & Feng H (2012). Anterior cruciate ligament reconstruction with remnant preservation: a prospective, randomized controlled study. The American Journal of Sports Medicine, 40 (12), 2747-55 PMID: 23075805


John Kelly said...

Kyle Harris makes some great poits. I would like to add that this study used irradiated allografts which are clearly inferior to fresh frozen. Furthermore, there was no MRI follow up to demonstrate any difference in graft incorportation. Lastly both groups did well clinically so it is hard to discern a difference in two cohorts who are doing rather well.
We have been performing remnant sparing 'holistic' anatomic ACL reconstruction for several years with superb results. There is no cogent data that a double bundle ACL is superior to an ANATOMIC single bundle reconstruction.Early studies compare doubel bundle to a single bundle with non anatomic femoral placement. We ascribe to Dr Ahn's teachings that preservation of native tissue helps graft incorporation. Also as Dr Johnson of Univ of Kentucky has indicated, remant preservation prevents fluid extravasation into the tibial tunnel and perhaps prevents tunnel expansion.
Our early results are encouraging as Dr Makani here at Penn has shown an approximately 1.3% failure rate one year follow up for active patients undergoing Holistic non irradiated allograft reconstruction.

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