Revision anterior cruciate ligamentsurgery: A historical perspective

REVISION ANTERIOR CRUCIATE LIGAMENT SURGERY: A HISTORICAL PERSPECTIVE ROBERT E. LEACH, MD

Anterior cruciate ligament reconstruction surgery has become a common operation performed on athletic patients. Despite the high success rate, a significant number require revision, which is a more difficult operation. This article reviews many of the reasons for ACL reconstruction failure and suggests that there are many options for revision that should work. KEY WORDS: ACL reconstruction, ACL revision, historical perspective

The history of anterior cruciate ligament (ACL) repairs and reconstructions is replete with significant advances that lead to clinical successes, and equally significant errors in technique and rehabilitation. Despite the obvious progress that we have made with regard to this modern reconstructive surgery, which dates to the 1960s, there have been so many problems in the evolution of surgical technique and rehabilation that the apparent successes of the 1980s and 1990s may deteriorate with time. Certainly at this point in time, there seems to be a belief on the part of most orthopaedic surgeons that we have found sound surgical techniques that can restore anteroposterior stability to the ACL-deficient knee. However, even the most ardent advocates of the present techniques will admit that we do not know exactly what the final patient results will be 20 years after reconstruction of these knees. Before 1960 there were orthopedists 1,2who wrote articles that clearly showed they recognized the problems of the anterior cruciate-deficient knee. They were able to make the diagnosis, and some even suggested surgical techniques to remedy the problem. However, I would date the modern history of ACL reconstruction to the early 1960s when Dr Kenneth Jones 3 published the results of surgery in which he used the central one third of the patellar ligament as a replacement for a torn ACL. I do recognize the earlier work of Hey-Groves 2 and O'Donoghue, 4 but their attempts at ACL reconstruction have not had long-standing benefits or effects. It is interesting to refer to the article that Jones published in The Journal of Bone and Joint Surgery in 1963 because this method of reconstruction is not too dissimilar from that which we n o w consider to be the standard reconstruction, ie, bone-patellar tendon-bone. The Jones article is only seven pages long and is followed by an article by O'Donoghue in which he describes his surgical technique for replacement of the ACL. This latter article is 20 pages

From the Department of Orthopedic Surgery, Boston University Medical Center, and the American Journal of Sports Medicine. Address reprint requests to Robert E. Leach, MD, 230 Calvary Street, Waltham, MA 02154. Copyright © 1998 by W.B. Saunders Company 1060-1872/98/0602-0001 $8.00/0

6{)

long, but the procedure, which uses the iliotibial track, has not withstood the test of time. Even though I believe that Jones deserves much credit for being one of the people who started us off on the right foot, it is interesting to consider several statements that he makes in that article. For instance he writes that, "Early suture of recent ACL tears gives us excellent results." Clearly, this optimistic consideration of early surgical repair of a torn ACL has not proven to be correct. Secondly, he placed his patient's reconstructed knees in a cast for 4 weeks. This is not too bad considering that many of his colleagues went 6 weeks and even longer. What I find particularly interesting about the article is that even though Jones reported on 11 patients, all of whom were doing well at the time of follow up, this particular surgical procedure then fell out of favor completely. For the rest of the decade more attention was paid to finding extra-articular methods of reconstructions than were devoted to intra-articular operations. The history of revision ACL surgery parallels that of primary ACL surgery. Once we decided that primary repair was not feasible, we began to look for materials that could be used for reconstruction of the ACL. These fall into three basic groups: autogenous tissue, allograft tissue, and synthetics. In the autogenous tissue we have at various times seen the use of the iliotibial band, the central quadriceps tendon, hamstring tendons (usually the semitendinosis and the gracilis) and the central third of the patellar tendon, which is the bone-tendon-bone reconstruction most commonly used, particularly in the United States. The bone-tendon-bone reconstruction has also used the medial third of the patellar tendon instead of the central third. At various times each of these tissues has had advocates 5-8 and detractors, but during the late 1980s and early 1990s the central third of the patellar ligament was by far the most popular tissue. In fact, it had seemed as if the arguments for other reconstructions were moot until a number of articles were published that espoused the use of hamstring tendons. 9,~° Surgeons who use the hamstrings believe that this operation is technically easier and fewer complications occur than result from using the central third of the patellar tendon. Allografts are an attractive alternative to any autograft material. Allografts reduce considerably the operative time Operative Techniques in Sports Medicine, Vol 6, No 2 (April), 1998: pp 60-63

because the graft does not have to be taken. There is the considerable worry concerning the possibility of infection, particularly from human immunodeficiency virus, but this is an exceedingly minimal risk. Perhaps the biggest problem with allografts presently is that although they have been performed by a number of surgeons, the long-term results are not as well known. We do not know whether allografts will produce long-term stability and still allow for early mobilization as well as autografts have. For years it has been hoped that some synthetic substance could be found that could replace the torn anterior cruciate. Synthetics come in two different categories. One category would be a synthetic that would physically replace the anterior cruciate. There are two substances that have been tested extensively. Dacron (Strybe Corporation, Kalamazoo, MI) has been tried by a number of surgeons, n and it has not been a successful long-term replacement. The other material used is Gore-Tex (W.L. Gore and Associates, Flagstaff, AZ). 12'1gThis seemed to be an excellent early replacement in certain cases, but the long-term results have not proven to be good. Gore-Tex could not be recommended for reconstruction of the anterior cruciate if there were other tissues available. There are other possibilities for using a synthetic to replace the ACL. The synthetic material may be used as a scaffold into which tissue grows and forms a new ACL. Carbon fiber has been used for this, and although it showed early promise in animals, it has not proven to be feasible in humans. Roth et a114have used a polypropylene stent called a ligament augmentation device (LAD) that is wrapped with other tissues such as a hamstring tendon or iliotibial band. The polypropylene lends stability during the early phase while the autogenous tissue is undergoing revascularization. This LAD and its accompanying tissue seem to be quite successful, but not more successful than the use of autogenous tissue alone. Although the LAD is not a common method for revision surgery at this point, it would present a possibility if hamstrings or patellar tendon were not available because the iliotibial band and the LAD have proven successful in previous revisions. Variations in material used to reconstruct the anterior cruciate have been paralleled by variations in the operative techniques. Fixation of the reconstructed tissue was always viewed as a problem, but the Kurosaka screw seems to be an excellent answer as to h o w to fix soft tissue within bony tunnels. When this screw cannot be used, as for instance with hamstrings that are attached outside the tunnel, the use of endobuttons or bicortical screws and washers seems to work well. Isometry and its attendant technical problem, tunnel placement, has always been viewed as a major problem. It seems to be much better handled than previously and bony tunnels in both the tibia and the femur are the usual methods of reconstructing knees with only an occasional surgeon using an over-the-top placement combined with a small notch in the lateral femoral condyle. Notchplasty, particularly in primary reconstructions of the ACL, continues to be much debated, ranging from orthopedists who feel that it should be used in virtually all, to those who use it only when they feel that the notch is too small or that osteophytes might jeopardize the graft. This is much more of a problem in revisions. FinallN the question of tensioning the graft materials is REVISION ACL SURGERY: A HISTORICAL PERSPECTIVE

still in a state of debate. There does not seem to be any difference in whether a revision ACL or a primary ACL reconstruction is being performed as to the tension that should be used, but there is still no real consensus as to exactly what tension should be used and how to achieve this. Tensions of up to 80 N have been used and this tension may be applied in different degrees of knee flexion depending on whether hamstring or patella tendon grafts are being used. is While the materials used to reconstruct the ACL ligament and the operative techniques used have gradually changed over the past several decades, there have been even more dramatic changes in the postoperative rehabilitative programs. Initiall)~ as with virtually all repairs and reconstruction of ligaments, knees were put into casts with the hope that the tissue would heal and the knee be protected while the reconstructed ligament was becoming viable. The knees were protected, but they were also becoming stiff. Following cast removal therapists and patients had to work assiduously to unstiffen the knee. In some instances it seems likely that the process of soft-tissue contracture that occurred actually contributed to the overall stability of the knee and that the mobilization process in some instances came at the expense of some stability. With more ACL reconstructions being performed, it became apparent that the lack of even small amounts of extension and flexion, which occurred following ACL reconstruction without early mobilization, was a significant detriment to many athletic patients. That realization plus problems with patellar mobilization led many surgeons to look at early mobilization in these patients. Casting was initially replaced by braces, which were locked in some flexion but allowed early weight-bearing and further flexion to 90o.16Then the move came to lock the knees in full extension because that seemed to be more important functionally. Eventually knees were allowed to go into full extension and started on early motion exercises including the use of continuous passive motion machines. ~7 Most of what I have written has applied equally to primary reconstruction ACL surgery as well as to revision surgery. Now, to deal specifically with revision surgery, the first question which must be answered by the surgeon is whether a particular patient is a good candidate for revision surgery after having experienced a primary failure. Was the initial surgery a reasonable procedure to perform? Could this patient have been rehabilitated by a program with or without the use of an ACL brace? 18-2° Having had one failure does the patient want to invest the time and energy into a second procedure, or have factors changed in his or her life that make revision surgery unreasonable? The fact that another physician or the first physician decided that a patient needed a reconstruction the first time does not mean, ipso facto, that a revision must be performed after the failure of the first one. The older and less active the patient, the less likely it is that he or she will need revision surgery. Lifestyles change, and patients may find ways to adjust to the lack of an anterior cruciate ligament. If both the surgeon and the patient decide that a second try is reasonable, then the surgeon must decide why the 61

original reconstruction or repair failed. Are there factors presently in play that may be detrimental to the revision surgery? If there was a primary infection then this seriously affects the thinking about performing revision surgery, although it certainly does not rule it out. What was the original tissue that was used for the reconstruction, and what is available now? H o w was the reconstructive tissue anchored? Were the tunnels in the tibia and femur put in proper position, or if not, would they be difficult to rechannel? Are the tunnels too large for the usual methods of anchoring soft tissue? Was a notchplasty performed previously, or is it obvious that a major notchplasty needs to be performed now? Is the patient lacking significantly in extension or flexion? Has the patellar been pulled inferiorly? If motion is lacking, should a rehabilitation program be started to see if motion can be increased; or, does the patient need to have an intraoperative arthroscopic debridement to restore full motion of the knee before revision surgery is attempted? What is the state of the patient's musculature? Are the thigh muscles strong enough so that a successful revision is likely to be helpful to the patient, or are the muscles so weak that the patient needs to be put on a strengthening program before any other procedure is considered? Most surgeons performing revision ACL surgery will likely choose to do the revision surgery in a manner similar to that which they would use for a primary construction. Bone-patellar tendon-bone is the most common method used in the United States. A critical question is if the central third of the patellar tendon has previously been used should the same tissue be reharvested in the operated knee or tissue harvested from elsewhere. There is some evidence that this regrown tissue is not of the same quality as the original tissue. Thus, other possibilities that would include the ipsilateral hamstrings, an allograft, or taking the mid third of the patellar tendon from the opposite uninjured knee would require thought. There is always the possibility when taking a graft from the other knee that the patient could end up with a problem on that knee, and for that reason the ipsilateral hamstrings seem to be a good choice. However, many surgeons do not have a problem with taking the central quadriceps tendon from the other knee, and it remains a choice. If over the next 5 years there are more long-term reports 21 showing good results with allografts, this could be a reasonable alternative in revision surgery. Why are there increasing numbers of revision ACLs being performed? The obvious reason would be that there are more primary operations and that a percentage of these fail. Public expectations are much higher than several decades ago and patients expect to go back to increased activities that will demand more from their knees and put the knee more at risk. Most patients who have had an operation to correct a particular deficit feel that if that deficit has not been corrected that they should have a second corrective operation. This means that there is a larger pool of patients wanting potential revisions. It would be nice if we thought that the majority of the patients who need revision surgery following reconstruction were patients who had gone back to highly competitive athletics and that major trauma had ruptured a well-functioning reconstructed ACL. This is probably a

62

lesser cause of secondary revisions having to be performed. The majority of revisions are performed because of technical errors during the primary operation. Most are probably related to placement of the graft in the femur or tibia. It seems likely that anterior placement of these grafts has been the major cause of patient symptomatology necessitating consideration of a secondary operation. Loss of fixation from inappropriate or poorly applied devices is another obvious problem. A good fixation device does not guarantee that fixation will be adequate. It must be used correctly. Incorrectly placed tunnels or tunnels that become enlarged are not only a cause for lack of stability or isometry but are a major problem in the considerations for revision surgery. If resorption of bone occurs, large tunnels may literally have to be refilled by bone graft before the revision surgery is performed. If that is not true, at least a large bone-patellar tendon-bone graft will have to be taken to adequately fill the tunnel. Sometimes not all pathology is corrected at the first operation and this may lead to failure. What can we expect from revision surgery in a previously failed ACL reconstruction? Some surgeons believe that we should have the same expectations as for primary surgery, and that the results will be roughly the same. Most surgeons would disagree. At the April 1997 Panther Sports Medicine Symposium in Pittsburgh, PA, there were a number of surgeons from around the world who had performed revision ACL surgery. The general feeling was that patients were very satisfied 50% to 6(}% of the time and partially satisfied 3(}% to 35% of the time with revision ACL surgery. This puts a remainder of from 5% to 2(}% of patients who are distinctly unhappy. There are some obvious possible reasons for this. Many patients having revision surgery may have already had some damage to the meniscus or to the articular surface, which is going to mitigate against a good overall result no matter how well performed the ACL revision is. It is this damaged articular cartilage that is likely to be the major determinant in the success or failure of the knee surgery. The longer a patient goes with an unstable knee combined with activity, the more likely that patient is to have damage to either the meniscus or the articular cartilage. Other factors that can cause lesser results would be if the patient has lost some range of motion either in flexion or extension. This may be difficult to regain, particularly after revision surgery. Secondary restraints that were not corrected in the first instance would probably be looser at the time of the second surgery. This may lead to having to perform more extensive surgery. There may even be the factor of the patient who may find it more difficult to rehabilitate from the same type of surgery the second time around, which could factor in the final result. In the 1990s it is obvious that primary reconstructions of the ACL can be performed with the expectation of regaining a stable knee in more than 90% of cases. It is also apparent that revision surgery can be performed with expectations that are somewhat lower. What we still do not know is what the condition of these knees will be in 20 years. Will stabilizing the knee and allowing and encouraging people to go back to athletic pursuits cause damage that would be significant in 20 years? We do know that ROBERT E. LEACH

ACL-deficient knees in active people lead to significant articular cartilage problems, so it seems logical that these knees should be stabilized in active patients. What is equally obvious is that any patient who is a candidate for revision ACL surgery must be considered de novo by the surgeon. The fact that the patient has had failed primary reconstruction of the ACL, even if by the same surgeon, does not mean that the patient must have a revision. It does mean that all factors must be reconsidered by patient and surgeon alike.

REFERENCES 1. Palmer I: On the injuries to the ligaments of the knee joint. Acta Chir Scand 153:665-667, 1938 2. Hey-Groves EW: Operation for the repair of the crucial ligaments. The crueiate ligaments of the knee joints. Br J Surg 7:505-515, 1920 3. Jones KG: Reconstruction of the anterior cruciate ligament: A technique using the central one-third of the patellar ligament. J Bone Joint Surg Am 45:925-932, 1963 4. O'Donoghue DH: A method for replacement of the anterior cruciate ligament of the knee. J Bone Joint Surg Am 45:905-924, 1963 5. Noyes FR, Barber SD, Mangine RE: Bone-patellar ligament-bone and fascia lata allografts for reconstruction of the anterior cruciate ligament. J Bone Joint Surg Am 72:1125-1136, 1990 6. O'Brien SJ, Warren RF, Pavlov H, et al: Reconstruction of the chronically insufficient anterior cruciate ligament with the central third of the patellar ligament. J Bone Joint Surg Am 73:278-286, 1991 7. Fulkerson JE Langeland R: An alternative cruciate reconstruction graft: The central quadriceps tendon. Arthroscopy 11:252-254, 1995 8. Lipscomb AB, Johnston RK, Snyder RB, et al: Secondary reconstruction of anterior cruciate ligament in athletes by using the semitendinosus tendon. Preliminary report of 78 cases. Am J Sports Med 7:81-84, 1979 9. Brown CH Jr, Steiner ME, Carson EW: The use of hamstring tendons for anterior cruciate ligament reconstruction. Technique and results. Clin Sports Med 12:723-756, 1993

REVISION ACL SURGERY: A HISTORICAL PERSPECTIVE

10~ Yasuda K, Tsujino J, Ohkoshi Y, et al: Graft site morbidity with autogenous semitendinosus and gracilis tendons. Am J Sports Med 23:706-714, 1995 11. Maletius W, Gillquist J: Long-term results of anterior cruciate ligament reconstruction with a Dacron prosthesis. The frequency of osteoarthritis after seven to eleven years. Am J Sports Med 25:288-293, 1997 12. Paulos LE, Rosenberg TD, Grewe SR, et al: The Gore-Tex anterior cruciate ligament prosthesis. A long-term follow-up. Am J Sports Med 20:246-252, 1992 13. Woods GA, Indelicato PA, Prevot TJ: The Gore-Tex anterior cruciate ligament prosthesis. Two versus three year results. Am J Sports Med 19:48-55, 199l 14. Roth JH, Kennedy JC, Lockstadt H, et al: Polypropylene braid augmented and nonaugmented intraarticular anterior cruciate ligament reconstruction. Am J Sports Med 13:321-336, 1985 15. Yasuda K, Tsujino J, Tanabe Y, et al: Effects of initial graft tension on clinical outcome after anterior cruciate ligament reconstruction. Autogenous doubled hamstring tendons connected in series with polyester tapes. Am J Sport Med 25:99-105, 1997 16. Paulos L, Noyes FR, Grood E, et al: Knee rehabilitation after anterior cruciate ligament reconstruction and repair. Am J Sports Med 9:140149,1981 17. Shelbourne KD, Klootwyk TE, DeCarlo M: Update on accelerated rehabilitation after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 15:303-308, 1992 18. Kannus E Jarvinen M: Conservatively treated tears of the anterior cruciate ligaments. Long term results. J Bone Joint Surg Am 69:10071012, 1987 19. Ciccotti MG, Lombardo SJ, Nonweiler B, et al: Non-operative treatmerit of ruptures of the anterior cruciate ligament in middle-aged patients. Results after long-term follow-up. J Bone Joint Surg Am 76:1315-1321, 1994 20. Daniel DM, Stone ML, Dobson BE, et al: Fate of the ACL-injured patient: A prospective outcome study. Am J Sports Med 22:632-644, 1994 21. Indelicato PA, Linton RC, Huegel M: The results of fresh-frozen patellar tendon allografts for chronic anterior cruciate ligament deficiency of the knee. Am J Sport Med 20:118-121, 1992

63