Instructional Course 102
Revision Anterior Cruciate Ligament Surgery
Bernard R. Bach, Jr, M.D.
nterior cruciate ligament (ACL) reconstructionsurgery is one of the most frequently performed
perative procedures in orthopaedic surgery. Therere estimates that 100,000 new ACL injuries occurnnually. Marked improvements have occurred in theast 15 years with regard to graft selection, tunnellacement, graft fixation, and rehabilitation that haveesulted in predictable outcomes for ACL surgerysing patellar tendon, hamstring, quadriceps tendon,utograft, and allograft tissues. Nevertheless, mosttudies report a clinical failure rate of between 10%nd 15% at short- and intermediate-term follow-ps.1-3 Increasing numbers of ACL reconstructionailures are being seen.4-11 The purpose of this articles to discuss the etiology of failure, approaches to theailed ACL patient, surgical technique issues, andesults of revision ACL surgery.7
The author has been in practice since 1986 and haserformed nearly 1,200 ACL reconstructive surgeries.atellar tendon autograft has been the predominantraft source in over 90% of the primary ACL surger-es, and between 75 and 100 ACL reconstructions areerformed annually. Of note is that my personal revi-ion rate has been less than 1%, although our clinicalollow-up studies would suggest a 10% failure rate.urrently, between 5 and 10 ACL failures are revisednnually; the majority of these patients are referred tour center. Nonirradiated patellar tendon allografts arehe primary graft choice in the majority of these pa-ients.
My revision experience is reflective of the matura-ion of my practice. In the first 5 years of, between986 and 1991, I had minimal experience (n 2) with
Address correspondence to Bernard R. Bach, Jr., M.D., 1725 W.arrison St, Suite 1063, Chicago, IL 60612, U.S.A. E-mail:[email protected] 2003 by the Arthroscopy Association of North America0749-8063/03/1910-0103$30.00/0
4 Arthroscopy: The Journal of Arthroscopic and Related Surger
evision surgery. In the second 5 years, between 1991nd 1996, 19 patients underwent revision reconstruc-ion. In the third 5-year period, 34 patients were re-erred for revision surgery. Over the last 2 years2001-2003) 26 revisions were performed. Througheptember 2003, the author has performed 81 revisionCL reconstructions, 71 of whom were referred to ourractice. More than 80% of these patients underwentonirradiated patellar tendon allograft revision sur-ery (Fig 1), 15% underwent patellar tendon autograftevision, and in 5% of the patients other tissues weresed. The majority of patients referred to our practicead failed patellar tendon autograft surgery. Thirty-hree of 34 of these individuals underwent revisionndoscopically; 19 were initially reconstructed endo-copically and 14 were performed using a 2-incisionrthroscopic technique. This is reflective of the patel-ar tendon being the predominant graft choice in thehicago area. Eight patients had a primary allograft
econstruction, 2 of whom were revised with a patellarendon autograft and 6 were revised with a nonirradi-ted patellar tendon allograft performed endoscopi-ally. Six patients had a primary hamstring recon-truction, 4 of whom were revised with a patellarendon autograft, and 2 with a patellar tendon allo-raft. One individual reconstructed with a patellarendon autograft was revised as a hamstring 2-incisionechnique. Failed extra-articular primary reconstruc-ions and primary repairs with augmentation werexcluded. This underscores the need to have a varietyf options available with regards to revision recon-truction.
ETIOLOGY OF FAILURE
It is well documented in the literature that the ma-ority of patients, when carefully analyzed, have aechnical component that may contribute to graft fail-
re. If a reconstruction fails within the first 6 months,
y, Vol 19, No 10 (December, Suppl 1), 2003: pp 14-29
a technical component usually plays a role (C. Harner,personal communication, May 2, 2003). This is gen-erally related to tunnel placement. Common technicalerrors include an anteriorized femoral tunnel (Fig 2), a
vertically oriented femoral tunnel (Fig 3), anteriorizedtibial tunnel (Fig 4), a posteriorized tibial tunnel (Fig5) and, less frequently, a posterior cortical blow out(Fig 6). Inadequate graft fixation may play a role infailure with marked femoral screw divergence, os-teopenic bone, or graft construct mismatch resulting in
FIGURE 1. A nonirradiated whole patellar tendon allograft withquadriceps tendon.
FIGURE 2. This lateral view shows the concept of a nonanatomicinitial femoral tunnel with a nonoverlapping secondary tunnel. Thissituation generally will not require hardware removal or primarygrafting. (Reprinted with permission from Bach BR Jr, MazzoccaA, Fox JA. Revision anterior cruciate ligament surgery. In: GranaWA, ed. Orthopaedic knowledge online. Rosemont, IL: AmericanAcademy of Orthopaedic Surgeons, 2003. Available at www.aaos.org/oko. Accessed May 15, 2003.7)
FIGURE 3. Anteroposterior view of right knee shows the conceptof a vertically oriented femoral tunnel (1). The initial tibial tunnelwas been placed in a sagittal plane, thus impacting femoral socketcreation and reorientation of tunnels using the divergent tunnelconcept. Note that there is minimal overlap on the femoral tunnelsand there should be an adequate femoral tube to allow unstagedgrafting. The initial femoral screw (1) can be advanced to precludethe possibility of having to bone graft this defect. On the tibial side,the reoriented tibial tunnel provides adequate intact tube to allowfor fixation. If there is significant overlap with these tunnels, it maynecessitate using a stacked screw fixation to provide distal fixation.(Reprinted with permission from Bach BR Jr, Mazzocca A, FoxJA. Revision anterior cruciate ligament surgery. In: Grana WA, ed.Orthopaedic knowledge online. Rosemont, IL: American Academyof Orthopaedic Surgeons, 2003. Available at www.aaos.org/oko.Accessed May 15, 2003.7)
15REVISION ACL SURGERY
inadequate tibial fixation.12,13 Several patients havepresented to our office with loss of fixation on thefemoral side with intra-articular migration of the fem-oral bone plug (Fig 7).14 Inadequate primary graftsource may be a contributing factor either with anarrow patellar tendon autograft or inadequate con-struct. Recent biomechanical testing has demonstratedthat hamstring autograft tissue with multiple loop con-structs provide excellent strength but fixation, incor-
poration and creep may play factors in potential fail-ure.15-21 Biological issues with regard to hyper-elasticindividuals and graft incorporation failure may con-tribute to failures. Medialization of the tibial tunnelmay result in graft abrasion occurring secondary toimpingement on the posterior cruciate ligament. Lat-eral wall abrasion, roof impingement, or interferencescrew abrasion may contribute to failure. Finally, un-recognized or unaddressed patholaxities may contrib-ute to primary graft failure. These include loss of asecondary restraint, such as a medial meniscectomy,chronic medial collateral ligament laxity, or unrecog-nized posterolateral laxity.22 Finally, the internal bio-logic milieu in an individual with early degenerativejoint disease may create a hostile environment forgraft incorporation and maturation.
FIGURE 4. Lateral view shows a nonoverlapped femoral tunneland an overlapped tibial tunnel. In this situation, to provide ananterior tunnel buttress, stacked screw fixation may be necessary toprovide adequate fixation at the time of revision. (Reprinted withpermission from Bach BR Jr, Mazzocca A, Fox JA. Revisionanterior cruciate ligament surgery. In: Grana WA, ed. Orthopaedicknowledge online. Rosemont, IL: American Academy of Ortho-paedic Surgeons, 2003. Available at www.aaos.org/oko. AccessedMay 15, 2003.7)
FIGURE 5. This lateral view shows the problem of an excessivelyposteriorized tibial tunnel. It is less problematic when a bone-tendon-bone graft has been used but can be a significant problemwhen soft tissue grafts are used. The revision tibial tunnel has beenanteriorized and has minimal overlap. Primary or staged bonegrafting may be necessary in situations where a soft tissue graft hasbeen used at the time of the initial reconstruction. (Reprinted withpermission from Bach BR Jr, Mazzocca A, Fox JA. Revisionanterior cruciate ligament surgery. In: Grana WA, ed. Orthopaedicknowledge online. Rosemont, IL: American Academy of Ortho-paedic Surgeons, 2003. Available at www.aaos.org/oko. AccessedMay 15, 2003.7)
16 B. R. BACH, JR.
It is critical when assessing patients in the office toattempt to determine the cause of failure. Radiograph-ically, one should be able to determine whether thefemoral or tibial tunnels are inadequately positioned.We have noted a transition from anteriorized femoraltunnels to vertically oriented femoral tunnels as acontributing technical cause of failure (Fig 3). Assurgeons have made a transition to an endoscopictechnique, many have not recognized the importanceof tibial tunnel orientation and how it impacts on
femoral tunnel placement. Although radiographicallysurgeons are much more consistent about placing thefemoral tunnel posterior in contrast to the 2-incisiontechnique, the anteroposterior radiographs frequentlydemonstrate a vertically oriented graft. This may re-sult in what is interpreted as a near normal Lachmantest with a firm endpoint, but unfortunately does notcontrol rotation. Therefore, patients may have lowKT-1000 side-to-side differences, clinical complaintsof instability and demonstrable low-grade pivot-shifttests.23,24 The other technical error that appears to