Editorial Commentary: ACL Reconstruction: Single-Bundle Versus Double-Bundle
Abstract: Double-bundle ACL reconstruction results in statistically significant, but not clinically significant improvement in knee anteroposterior stability, and improved rotational stability, according to the pivot-shift test, which is subjective. However, double-bundle does not improve clinical outcomes, does not reduce graft failure rates, and is more complex, more expensive, takes longer, and is harder to revise. As a result, for now, we prefer single-bundle ACL reconstruction.
See related article on page 1185
M
ascarenhas, Cvetanovich, Sayegh, Verma, Cole, Bush-Joseph, and Bach ask a controversial question in their article “Does double-bundle anterior cruciate ligament reconstruction improve postoperative knee stability compared to single-bundle techniques? A systematic review of overlapping meta-analyses.”1 And, Mascarenhas et al. conclude that the answer is yes, double-bundle (DB) does improve knee postoperative stability compared with single-bundle (SB). However, the authors also conclude that while DB improves stability to a greater extent than SB, their results also reveal that there is no significant effect of DB compared with SB “on clinical outcomes and risk of graft failure.” And clinical outcome and graft failure are the variables that matter to patients. Moreover, the authors observe that, while the stability differences measured using KT arthrometry are statistically different in favor of DB, “it is unlikely that less than a 1-mm difference is a clinically meaningful result.” In other words, statistical significance does not equal clinical significance,2 and for the record, the actual differences reported ranged “from 0.56 to 0.74 mm,” i.e., less than 1 mm. In addition to anterior translation, examined using the Lachman test and quantitated using KT arthrometry, as above, rotational stability was evaluated using the pivotshift physical examination maneuver. Again, DB improved stability to a greater extent than SB, but this also requires clarification. The pivot-shift is well known to “demonstrate some user subjectivity in grading, interexaminer variability, and dependence on patient Ó 2015 by the Arthroscopy Association of North America 0749-8063/15347/$36.00 http://dx.doi.org/10.1016/j.arthro.2015.04.078
cooperation.”1 We agree with Mascarenhas et al. that the pivot-shift test is subjective and difficult to perform, particularly on an awake patient. In addition, as observed by Mascarenhas et al., a vertically oriented SB graft results in an increase in the pivot shift, and therefore agree when they remark, “Of interest would be the comparison of a single-bundle graft placed centrally within the femoral footprint compared with a doublebundle graft that fills more of the femoral footprint.” The take home message is that SB and DB have equal “clinical outcomes and risk of graft failure,”1 and no clinically significant differences in AP translation, but DB results in improved stability as measured by the pivot-shift test. In addition, Mascarenhas et al. note in favor of SB that:
DB DB DB DB
ACL reconstruction is more complex than SB, takes longer, is harder to revise, is more expensive.
And, Mascarenhas et al. also note in favor of DB that “DB ACL reconstruction may lead to a lower incidence of osteoarthritis.” So should we perform SB or DB ACL reconstruction? Based on Mascarenhas et al., both techniques have advantages and disadvantages, and risks and benefits. So, since the jury is still out, we can editorialize3-6 and share our personal experience based on 21 years of clinical practice, with a specific clinical and research interest in the ACL, and a reasonably high clinical volume. Our experience is that the most troublesome dilemma patients experience after ACL reconstruction is graft failure; we also do encounter patients with symptomatic osteoarthritis, but even over the long-term, symptomatic osteoarthritis seems significantly less problematic than graft
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 6 (June), 2015: pp 1197-1198
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EDITORIAL COMMENTARY
rerupture. And rarely do patients complain of recurrent instability absent graft failure, even if their knees feel lax on physical examination. As a result, for now, in consideration of the disadvantages of DB noted above, and in the context of equal clinical outcomes and equal rates of graft failure, we prefer SB reconstruction. Those who disagree are strongly encouraged to send in letters to the editor. James H. Lubowitz, M.D. Editor-in-Chief
References 1. Mascarenhas R, Cvetanovich GL, Sayegh ET, et al. Does double-bundle anterior cruciate ligament reconstruction improve postoperative knee stability compared with singlebundle techniques? A systematic review of overlapping meta-analyses. Arthroscopy 2015;31:1185-1196.
2. Rossi MJ, Lubowitz JH, Provencher MT, Poehling GG. Precision versus accuracy: A case for common sense. Arthroscopy 2012;28:1043-1044. 3. Richmond JC, Lubowitz JH, Poehling GG. Prompt operative intervention reduces long-term osteoarthritis after knee anterior cruciate ligament tear. Arthroscopy 2011;27: 149-152. 4. D’Agostino RB Jr, Lubowitz JH, Provencher MT, Poehling GG. A modest proposal for a clinical trial on single-bundle versus double-bundle anterior cruciate ligament reconstruction. Arthroscopy 2012;28:301-304. 5. Lubowitz JH, Provencher MT, Poehling GG. Do largediameter hamstring grafts in young patients prevent knee osteoarthritis after ACL reconstruction? Arthroscopy 2012;28:447-448. 6. Lubowitz JH, Provencher MT, Poehling GG. Climbing the level of evidence ladder: Prospective, comparativeeffectiveness knee ACL and PCL research. Arthroscopy 2013;29:399-400.
Abstract: Double-bundle ACL reconstruction results in statistically significant, but not clinically significant improvement in knee anteroposterior stability, and improved rotational stability, according to the pivot-shift test, which is subjective. However, double-bundle does not improve clinical outcomes, does not reduce graft failure rates, and is more complex, more expensive, takes longer, and is harder to revise. As a result, for now, we prefer single-bundle ACL reconstruction.
See related article on page 1185
M
ascarenhas, Cvetanovich, Sayegh, Verma, Cole, Bush-Joseph, and Bach ask a controversial question in their article “Does double-bundle anterior cruciate ligament reconstruction improve postoperative knee stability compared to single-bundle techniques? A systematic review of overlapping meta-analyses.”1 And, Mascarenhas et al. conclude that the answer is yes, double-bundle (DB) does improve knee postoperative stability compared with single-bundle (SB). However, the authors also conclude that while DB improves stability to a greater extent than SB, their results also reveal that there is no significant effect of DB compared with SB “on clinical outcomes and risk of graft failure.” And clinical outcome and graft failure are the variables that matter to patients. Moreover, the authors observe that, while the stability differences measured using KT arthrometry are statistically different in favor of DB, “it is unlikely that less than a 1-mm difference is a clinically meaningful result.” In other words, statistical significance does not equal clinical significance,2 and for the record, the actual differences reported ranged “from 0.56 to 0.74 mm,” i.e., less than 1 mm. In addition to anterior translation, examined using the Lachman test and quantitated using KT arthrometry, as above, rotational stability was evaluated using the pivotshift physical examination maneuver. Again, DB improved stability to a greater extent than SB, but this also requires clarification. The pivot-shift is well known to “demonstrate some user subjectivity in grading, interexaminer variability, and dependence on patient Ó 2015 by the Arthroscopy Association of North America 0749-8063/15347/$36.00 http://dx.doi.org/10.1016/j.arthro.2015.04.078
cooperation.”1 We agree with Mascarenhas et al. that the pivot-shift test is subjective and difficult to perform, particularly on an awake patient. In addition, as observed by Mascarenhas et al., a vertically oriented SB graft results in an increase in the pivot shift, and therefore agree when they remark, “Of interest would be the comparison of a single-bundle graft placed centrally within the femoral footprint compared with a doublebundle graft that fills more of the femoral footprint.” The take home message is that SB and DB have equal “clinical outcomes and risk of graft failure,”1 and no clinically significant differences in AP translation, but DB results in improved stability as measured by the pivot-shift test. In addition, Mascarenhas et al. note in favor of SB that:
DB DB DB DB
ACL reconstruction is more complex than SB, takes longer, is harder to revise, is more expensive.
And, Mascarenhas et al. also note in favor of DB that “DB ACL reconstruction may lead to a lower incidence of osteoarthritis.” So should we perform SB or DB ACL reconstruction? Based on Mascarenhas et al., both techniques have advantages and disadvantages, and risks and benefits. So, since the jury is still out, we can editorialize3-6 and share our personal experience based on 21 years of clinical practice, with a specific clinical and research interest in the ACL, and a reasonably high clinical volume. Our experience is that the most troublesome dilemma patients experience after ACL reconstruction is graft failure; we also do encounter patients with symptomatic osteoarthritis, but even over the long-term, symptomatic osteoarthritis seems significantly less problematic than graft
Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 31, No 6 (June), 2015: pp 1197-1198
1197
1198
EDITORIAL COMMENTARY
rerupture. And rarely do patients complain of recurrent instability absent graft failure, even if their knees feel lax on physical examination. As a result, for now, in consideration of the disadvantages of DB noted above, and in the context of equal clinical outcomes and equal rates of graft failure, we prefer SB reconstruction. Those who disagree are strongly encouraged to send in letters to the editor. James H. Lubowitz, M.D. Editor-in-Chief
References 1. Mascarenhas R, Cvetanovich GL, Sayegh ET, et al. Does double-bundle anterior cruciate ligament reconstruction improve postoperative knee stability compared with singlebundle techniques? A systematic review of overlapping meta-analyses. Arthroscopy 2015;31:1185-1196.
2. Rossi MJ, Lubowitz JH, Provencher MT, Poehling GG. Precision versus accuracy: A case for common sense. Arthroscopy 2012;28:1043-1044. 3. Richmond JC, Lubowitz JH, Poehling GG. Prompt operative intervention reduces long-term osteoarthritis after knee anterior cruciate ligament tear. Arthroscopy 2011;27: 149-152. 4. D’Agostino RB Jr, Lubowitz JH, Provencher MT, Poehling GG. A modest proposal for a clinical trial on single-bundle versus double-bundle anterior cruciate ligament reconstruction. Arthroscopy 2012;28:301-304. 5. Lubowitz JH, Provencher MT, Poehling GG. Do largediameter hamstring grafts in young patients prevent knee osteoarthritis after ACL reconstruction? Arthroscopy 2012;28:447-448. 6. Lubowitz JH, Provencher MT, Poehling GG. Climbing the level of evidence ladder: Prospective, comparativeeffectiveness knee ACL and PCL research. Arthroscopy 2013;29:399-400.
