Anterior cruciate

ligament reconstruction using quadriceps patellar tendon graft

Part I.

Long-term followup

JAMES G.

HOWE,*† MD,

ROBERT J. JOHNSON,* MD, MICHAEL J. KAPLAN,* MD, BRADEN FLEMING,* MS, AND MARKKU JARVINEN,‡ MD

From the *Department of Orthopaedics & Rehabilitation, McClure Musculoskeletal Research Center, University of Vermont College of Medicine, Burlington, Vermont and the ‡Department of

Surgery, Tampere University Hospital, Tampere, ABSTRACT

Finland

widely accepted as the therapy of choice for the young and active patient. Proponents of various grafts and techniques agree that the ACL serves as the primary restraint of anterior displacement and that its replacement is essential to restore knee joint stability. The evolution of autogenous, autologous, and synthetic graft materials continues in an effort to create a compatible material positioned and tensioned so as to mimic the complex orientation and configu-

Eighty-three patients with ACL reconstructions using quadriceps patellar tendon graft were evaluated in a 10 year (mean, 5.5 years) follow-up study. A five-part analysis, consisting of physical examination, questionnaire, Genucom analysis, operative note review, and radiographs, was performed. Seventy-six percent were categorized as satisfactory. Ninety-two percent were content with their results, while only 4% were unsatisfied. Ninety-three percent of the patients had no significant pain and 95% had no giving way postreconstruction. Ninety-two percent had no more than a mild functional deficit. Eighty-seven percent and 90% of the patients had no significant Lachman or pivot shift by examination, respectively. Our results showed no increase in failure over time (1 to 10 years), although those operated on during the initial 5 years showed more radiographic degenerative changes. Plotting our results in classification systems of other authors yielded success rates as good as or better than those using our own criteria. An objective means by which to quantify laxity did not reliably correlate with the quantifying of laxity made by physical examination. Only the lack of a formal rehabilitation program greater than 4 months postoperatively and repaired tears of the medial or lateral collateral ligaments proved to be significant risk the

ration of the normal ACL. 3,5, 8,12, 21, 30, 32, 35, 37, 59, 70, 73, 77, 80, 84 Recent advances in instrumentation and fixation have facilitated more accurate placement of the graft material.’, 11 35, 53, 63 75, 77, 83 Many orthopaedists believe that the advent of arthroscopically assisted reconstructions has lessened the morbidity and rehabilitation time, making operative treatment less formidable for the patient and more attractive to the surgeon. 38,42,75 Finally, the trend toward more aggressive physical therapy, consisting of muscle training and range of motion exercises, has accelerated the re-

habilitation regimen.&dquo;, 66,72,73,74 Butler et al. 13,14 and various other authors IS, 54 are proponents of the patellar tendon graft, citing it as the superior substitute from a biomechanical standpoint. Its tensile strength and durability as a scaffold allow for adequate revascularization and subsequent proliferation of a new ligamentous structure.3, 4, s, s,14,18, s5, 71 Numerous clinical followup studies document the success of ACL reconstructions using one-third of the patellar tendon as graft.2, 9, ls,19, 45, 48 Nevertheless, many reports on techniques for ACL reconstruction describe the use of alternative graft substitutes. Transplantation of tendon (gracilis, semitendinosus, quadriceps), facia lata, and even menisci have been used as intraarticular and extraarticular stabilizers of the knee joint.1419,30,65 Follow-up results document success rates of 50% to 90% depending on the duration of the study and the

factors for poor recovery.

Reconstruction of the anterior cruciate deficient knee is now t Address correspondence and repnnt requests to James G Howe, MD, Department of Orthopaedics and Rehabilitation, University of Vermont, College of Medicine, Given Building, Burlington, VT 05405 447

448 86

graft chosen,10 12, 17, 20, 23, 27 30, 34, 45, 52, 61, 78, 81, 85 Autologous materials, including frozen cadaveric allograft and synthetic materials, such as GORE-TEX, Dacron, and polypropylene, continue to be investigated both clinically and in vitro.8 ’J’J. 82, 83 The success of these techniques remains indeterminate and the subject of ongoing studies. Kannus and Jarvinen 5’ reviewed the current literature of ACL follow-up studies, including conservative 26 33, 36, 47, 62, 67 69 and operative treatments. They concluded that third-degree ruptures do poorly with nonoperative treatment and rehabilitation and that posttraumatic arthritis is a common sequela. This suggests that stabilization of an ACL deficient knee may retard the degenerative process. Yet, a prospective study comparing the articular cartilage damage in patients reconstructed with those treated nonoperatively remains to be done. The treatment of ACL ruptures has made a full circle from the original description of reconstruction by Campbel115 in 1939, using the patellar tendon as a graft. For years primary repair with or without augmentation for complete ACL ruptures was considered the treatment of choice. Later, a trend toward a nonoperative muscle strengthening program with an option for later reconstruction developed. 10,12,33, ’34, 40, 41, 44 In 1963, Jones49 described the procedure using the central third of the patellar tendon in a manner much like that described by Clancy et al.l9 in 1982. Current investigations center on material analysis, intraarticular placement, and fixation. Nevertheless, as recently as 1983, Johnson44 presented 58 orthopaedic surgeons with a hypothetical case of a 20-year-old healthy, active male with an isolated complete ACL injury. Of this group of surgeons, 60.5% opted for repair with or without augmentation, 8.5% suggested immediate grafting, and 31% favored a nonoperative approach of rehabilitation. Kannus and Jarvinen5o attributed this variability to four biases that cloud the ACL literature: 1. Susceptibility bias arises from comparing the results of treatments for groups that have different original prognoses. Specifically, ACL deficient knees must be stratified according to concomitant knee injuries that alter the kinematics and function of the joint. Age, activity level, and rehabilitation must be accounted for. 2. Performance bias refers to the variability of surgical techniques. Different surgeons, using different procedures and postoperative regimens, can surely affect results. Reinjury, duration of followup, and patient motivation may also be significant factors. 3. Detection bias, or the means of qualifying results, remains a fundamental problem in ACL followups. At least 10 different rating systems exist, each with its own particular emphasis on objective and subjective functional criteria. Reliable comparisons between treatments can only be made with a comprehensive rating system that employs the criteria of previously developed evaluation systems. 4. Finally, transfer bias refers to the actual percentage of patient followup. Rudicel and Esdaile76 point out that the

credence of a study is patients that are lost to

directly related followup.

to the number of

Our study is designed to overcome these four biases within the confines of a retrospective long-term followup. The quadriceps patellar tendon technique, as described by Marshall, is no longer widely used. Nevertheless, this review has merit as a complete and long-term followup of a single operative procedure from which information for current operative methods can be inferred and compared.

MATERIALS AND METHODS One hundred twelve

were operated on by a single (RJJ) between 1977 and 1985 at the Medical Center Hospital of Vermont in Burlington. The patients were young and active with chronically ACL deficient knees and had failed previous conservative therapy and/or operative treatment. All patients underwent an ACL reconstruction according to the technique described by Marshall et a1.6° The middle one-third of the patellar tendon and its extension into the quadriceps tendon was used as a graft. Our physical therapy regimen has changed significantly from the protocol used with those patients in the late 1970s. Initially we casted patients for 6 weeks and began range of motion exercises with restrictions on quadriceps training until 6 months postoperatively. There was a period of transition where we used a splint for 2 weeks and began passive

orthopaedic

patients

surgeon

range of motion from 0° to 20°, but again did not allow weightbearing for at least 8 weeks and did not start full quadriceps training until 6 months. Attempts were made to contact all 112 patients by two

mailings and follow-up telephone calls. Eighty-nine patients contacted and 23 were lost to followup. Of the 23 patients lost to followup, 2 had died and 1 refused to participate. Three of the patients contacted gave only a cursory were

response as to their functional status and were therefore eliminated from the study. Thirteen patients could only participate by phone questionnaire because of distance barriers and were included in the study, but not in those

portions concerning follow-up examination. Seventy-three patients, with 74 reconstructed knees, were fully evaluated. Three of these 73 patients were eliminated from the study because they lacked a normal contralateral knee: 2 had a contralateral ACL deficient knee and 1 had bilateral reconstructions. Therefore, 83 patients participated in the study, of which 70 were fully evaluated. Of the 83 patients participating in the follow-up study, additional procedures other than the ACL reconstruction included: meniscectomy (34 patients), pes anserinus transfer (34 patients), and medial collateral and posterior oblique ligament reconstruction (1 patient). All patients underwent the same postoperative rehabilitation program. The patients returning for followup were evaluated by a physical examination, a questionnaire, Genucom (FARO, Montreal, Canada) measurements, and radiographs. The clinical examinations were performed independently by two examiners. A four-point scale (0 to 3) was used in analyzing

449

both knees with reference to anterior-posterior laxity at 30° and 90° of flexion, varus and valgus laxity at 0° and 20° of flexion, and anteromedial, anterolateral, and posterolateral laxity at 90° of flexion. Grade 0 refers to no discernible laxity. Grade 1 represents a minimal excursion with a hard end point. Grade 2 refers to a pronounced excursion with a solid end point. Grade 3 laxity refers to pronounced excursion with a soft or absent end point. The pivot shift phenomenon was graded with: 0, no shift; 1, a slight shift or pivot glide; 2, a substantial shift with moderate subluxation; or 3, a marked subluxation. Joint line tenderness and crepitus were recorded. Patients then responded to a questionnaire to determine the subjective and functional status of the individual before injury, after injury but before reconstruction, and after reconstruction. Our questionnaire was devised after careful consideration of previous rating systems used by Marshall et ale Clancy et al.,19 Larson,56 Lysholm and Gillquist, 57 Hughston et al.,J9 Jensen et al.,41 Johnson et a1.,45 Noyes et al.,68 and Simonet and Sim.’9 This composite questionnaire documented the mechanism of injury, initial treatment, operative procedures before and after reconstruction, rehabilitation before and after reconstruction, brace use, compliance with medical directives, and the frequency and severity of reinjury events before and since reconstruction. A specific, six-point, subjective grading scale for both before and after reconstruction was made to rate symptoms including pain, effusion, and giving way. A four-point scale was likewise used for stiffness, locking, and grinding (Table 1). Overall function was also rated subjectively by the patient before and after reconstruction with an eight-point scale (Table 2). The functional analysis evaluated specific sport function,64 stair-climbing, and walking capacity before injury, after injury but before reconstruction, and after reconstruction (Fig. 1). An objective appraisal of the knee’s ligamentous status was performed with the Genucom Knee Evaluation System. The Genucom consists of three primary components: an electrogoniometer, a dynamometer, and a data acquisition computer. The electrogoniometer straps to the distal tibia and measures motion of the tibia relative to the femur with six degrees of freedom. The Genucom seat floats on a dynamometer capable of measuring the loads and moments applied to the knee by the examiner. All studies were done by a single machine operator so as to avoid interexaminer variability.&dquo; Genucom measurements included bilateral documentation of anterior-posterior excursion of the tibia relative to the femur at 30° (Lachman test) and 90° (drawer test) of flexion. Anterior-posterior and lateral weightbearing radiographs of the patients’ knees were evaluated. Sixty-seven patients had current films taken at followup. Forty-five patients had preoperative films that were available for comparison. Independent readings by two orthopaedists were made according to the criteria of Ahlback’ and Fairbank.24 A specific score, a modification from the scale of Kannus et a1.51 grading the degree of severity from 0 to 4 (0 being normal

TABLE 1

Symptoms rating scale

TABLE 2

Overall function

score

severe), was made for joint space narrowing, ligament calcification, varus-valgus angulation, osteophytes, sclerosis, cyst formation, and condyle flattening. Any rating change of two or greater between preoperative and postoperative films was considered significant (Fig. 2). Chi square analysis was used for statistical evaluation of all comparisons. The Spearman’s rank correlation was used

to 4 most

450

Figure

1. The

sports performance questionnaire.

to determine the correlation between the results of the

Genucom and clinical examination for anteroposterior displacement of the knees tested at 30° and 90° of flexion. All patients were categorized as either a satisfactory or unsatisfactory result (Table 3). To be considered satisfactory the patient had to have: 1) a negative Lachman test (i.e., less than Grade 2 on our clinical scale or a difference by Genucom analysis between control and affected leg less than 4 mm anterior excursion of tibia relative to the femur); 2) no pivot sign by clinical examination (i.e., Grade 2 or greater); 3) no pain or only occasional pain with strenuous

activities such as jogging, tennis, or hiking (Table 1, Grade 3 or greater); 4) no frank subluxation or no more than two episodes of &dquo;giving way&dquo; per year (Table 1, Grade 2 or greater); and 5) overall function of Grade 3 or greater (Table 2), that is, patient is still physically active in those sports in

which

he/she chooses

to

participate.

RESULTS of 83 patients (76%) qualified as satisfactory (Table 3). A failure analysis of patients categorized as un-

Sixty-three

451

Figure 2. The radiologic

knee

scoring

scale.

satisfactory is listed in Table 4. Two of those who were rated unsatisfactory were clinically and objectively acceptable, that is, their graft was found to be intact, but these patients indicated that they had significant pain. One patient (No. 13) who had undergone more than two operative procedures on her knee prior to the reconstruction, had advanced degenerative changes by radiographic analysis even before the reconstructive procedure. Another patient (No. 5) had a positive pivot shift, but no other clinical or symptomatic ratings consistent with failure. Nonetheless, he is considered unsatisfactory because of his positive pivot sign. Of the 13 patients who only had a questionnaire evaluation and no

clinical or Genucom examination, four were rated as unsuccessful secondary to symptoms (Table 4). A chi square test was used to determine the trend of failures over time (Fig. 3). The incidence of failures did not increase as a function of time postoperatively (P 0.098). However, patients operated in the initial 5 years demonstrated more radiographic evidence of degeneration than those who underwent surgery during the last 5 years. Eighty-three patients completed all of the questionnaire. Seventy-six patients (92%) were satisfied with their result. Four patients (5%) were somewhat disappointed, and three (3%) were unsatisfied with their results. The seven patients =

452

Qualifiers

TABLE 3 of rating systems designatmg patients successful or unsuccessful results

not failures and their decrease in activity was secondary to lifestyle changes rather than a functional deficit. Overall, 76 patients (92%) had no more than a mild functional deficit were

as

havmg

(Table 2). The functional sports performance analysis is given in Part II. The functional analysis showed the percentage of patients able to climb stairs without symptoms increased from 43% to 81% (P < 0.001, Table 5). After reconstruction, the number of patients who could walk more than 1 mile without mild pain increased from 45% to 82% (P < 0.001, Table 5).

Clinical examination

There

less than content had residual pain and/or stiffand four (5%) of these patients qualified as failures. Six patients (7%) had significant pain at followup whereas 35 patients (42%) had significant pain before reconstruction (P < 0.001). After reconstruction, four patients (5%) had frank episodes of giving way, compared to 93% of patients before reconstruction (P > 0.001, Table 5). Although 91% of patients regarded the condition of their knees to be worse than preinjury, 82% had increased their level of activity relative to their prereconstruction/postinjury state. Fifteen percent of the patients did not or could not increase their activity after reconstruction, although the majority had fewer symptoms. Two patients stated they were less active following reconstruction. These two patients who

were

ness

TABLE 4 Failure analysis

&dquo;

Patients evaluated

by questionnaire alone.

were no

statistically significant differences between

the two clinical examiners’ results for any of the physical examination tests. In cases where there was a discrepancy, the less satisfactory result was accepted. Of the 70 patients fully evaluated, 16 were unsuccessful due to a positive pivot or Lachman examination. Ninety percent (N = 63) of the reconstructed patients did not have a pivot shift, but 33 (47%) did show a pivot glide. Sixty-two of the patients (88%) had less than a 10° decrease in the range of motion (either flexion or extension) of their reconstructed knees as compared to the unoperated (normal) knees. Two patients lost greater than 5° of extension. A positive Lachman test measured by the Genucom was considered to be a difference of greater than 4 mm of anterior excursion between the control and affected knee. Sixty-two patients (89%) had a negative Lachman test by this criterion. The Lachman test results by manual and Genucom testing gave similar numbers of graft failure (nine and eight patients, respectively). Only four patients demonstrated anteroposterior excursions of the tibia indicative of graft failure by both physical examination and Genucom. Therefore,

453

Figure 3. Failures versus year. Bars represent the total number of patients operated on and the total number of failures for a given year. The number listed for each year represents the failure rate. TABLE 5 Functional evaluation

4. Genucom versus Lachman examination. Genucom laxity values between -90 and 90 N of posterior/anterior shear force applied to the proximal tibia with the knee joint at 30° of flexion. Clinical assessment is subjective clinical grade level for Lachman test. Bars represent ±2 SD.

Figure

measurements are

lateral femoral condyle. Ligament calcification was substantial near the medial femoral condyle in three patients (5%) and near the lateral tibial condylar spine (as seen on the anteroposterior view) in two patients (3%). There were no significant cysts seen. Angle deformation, condylar flattening, and subchondral sclerosis were not found. Although there was an increase in degenerative change at the time of followup, there is no significant correlation between the degree of radiographic change and a satisfactory or unsat-

isfactory rating.

13 patients had unacceptable laxity determined by either physical examination and/or Genucom measurements, and there was an overall 19% failure rate (13/70 clinically tested). We investigated the degree to which our clinical assessment of anterior excursion correlated with actual Genucom measurements in millimeters. Mean Genucom measurements did differ significantly for different clinical grades (P

0.02 for both affected and nonaffected knees). However, while the correlation between the physical examination and the Genucom was significant, it is not possible to accurately predict one clinical grade of laxity from another in actual millimeters of displacement (Figure 4). Of the 65 patients who had roentgenograms at followup, 45 had preoperative films available for comparison. Roentgenograms showing changes of 2 points or more for any of the observed findings shown in Figure 2 were classified as significant. Forty-three (66%) of the patients imaged at followup had at least one such significant change. Twentyfour patients (37%) had medial space narrowing. Osteophytes rating changes of 2 or greater were found in 20 patients (31%) at the medial femoral condyle, in 14 (22%) at the medial tibial plateau, and in 5 patients (8%) at the
4 medial and lateral collateral repair or reconstruction (5/80 patients) significantly affected the results (Table 7). Other procedures done at the time of reconstruction are listed in Table 8. DISCUSSION This study illustrates that the use of quadriceps patellar tendon graft for ACL reconstruction can yield a high pro-

454

portion of satisfactory results that do not deteriorate over a 10 year period. The results are better than those treated solely by conservative and rehabilitative measures.2613,36,47,62,67,69 A 76% satisfactory rate supports the efficacy of this procedure for the appropriate patient population. Follow-up studies of bone-patellar tendon-bone grafts reveal comparable or superior results, but the studies are of shorter follow-up duration.9,16,30 Our classification for a satisfactory result is predicated on

TABLE 6

Grading classifications

grading systems of six other authors and thus it is possible to evaluate patients by their criteria and determine how our population fared (Table 6). When our patients were analyzed using the grading systems of Noyes et al., Lysholm,Clancy and Gillquist, Clancy et al., and Hughston et al., the success rates were all higher than our own 76% figure. One needs to keep in mind that Clancy et al. and Hughston et al. placed more emphasis on the patient’s subjective appraisal of functions. The scale developed by Marshall et al. shows a slightly higher proportion of fair ratings representing a notable but not significant increase of failures. Their grading system relies heavily on multidirectional joint stability, with less emphasis on functional results. There are many therapeutic choices for the patient presenting with a third-degree ACL tear. Repair, reconstructhe

°

Significantly different. TABLE 7 Risk factor analysis

or conservative rehabilitative measures represent the three main alternatives. Traditionally, the choice has depended on acuteness of the insult, the degree of structural and functional damage, the experience of the surgeon, and the particular character and circumstance of the patient. Age, athletic interest, motivation, and reliability, must also be taken into consideration. The physician must realize that patients regard their surgery as worthwhile if they have an improved lifestyle, meaning greater function. Pain, swelling, and giving way are the manifestations limiting such function and must be correlated with a specific activity and intensity level to understand their true implications. The particular mechanisms of injury and mode of treatment from the initial medical consult was not shown to

tion,

affect patient prognosis. &dquo;

Concomitant

&dquo;

contributing

Significant. TABLE 8 done at time of reconstruction&dquo;

procedures

a

MCL, medial collateral ligament; LCL, lateral collateral liga-

ment.

to

Meniscectomy is well recognized as degenerative changes, however those pa-

tients who had meniscectomies prior to or with their reconstruction had no worse results than those without meniscectomy.46 It is possible that with longer followup the results of patients who had a meniscectomy as well as a reconstruction will deteriorate. Compliance with medical directives and frequency of reinjury before and after reconstruction were likewise not significantly associated with a poorer knee prognosis. There was no correlation between a loss of motion and those knees graded satisfactory or unsatisfactory. An increase in incidence and severity of radiographic changes over time, however, was not accompanied by an increase in the incidence of unsatisfactory results. Of the risk factors examined (operative procedures before reconstruction, rehabilitation, bracing, compliance with medical directives, and reinjury and associated operative procedures), only the lack of an organized postreconstruc-

455

tion rehabilitation program lasting longer than 4 months and an associated medial and lateral collateral ligament reconstruction adversely affected the results. Kornblatt et al. 52 noted a high incidence of pivot glide in their follow-up study. Although a pivot glide did exist in many of our patients (47%), we found no evidence that this phenomenon influenced our results and thus we feel it is not a contraindication to the procedure. Using two examiners who were adept at both clinical and Genucom knee evaluation, we were still unable to accurately correlate a specific grade of ACL laxity with actual anterior/ posterior displacement (in millimeters). At best, one can

Seventy-six percent of the patients had a satisfactory result. Ninety-two percent of the patients were content with their outcome. Successful patients are likely to perform at 75% and 92% of their original level in the most strenuous and least strenuous sport groups, respectively. Averaging all patients and sports groups, a 77% return to preinjury performance level can be expected. Eighty-seven percent of the grafts were intact by clinical examination, while 89% were intact by Genucom evaluation. A formal rehabilitation program greater than 4 months increases the rate of satisfactory results. The examiner can distinguish with repeated accuracy those knees with gross ACL laxity from those with stable ligamentous structures. More specific clinical gradations of laxity are nonreproducible.

~

~

~

~

expect to reliably diagnose only gross laxity clinically. Herein lies the value of

rately

measure

an objective device that can accuACL laxity for optimal therapy and follow-

~

up reference.

It is difficult to interpret what, if any, effect the changes postoperative rehabilitation has on patient performance and knee function. Our experience has led us to be more aggressive in early knee therapy. Currently, our ACL reconstructions are done with bone-patellar tendon-bone or hamstring grafts, using an arthroscopically assisted technique. The postoperative regimen begins with passive range of motion from 0° to 40° while in the hospital. Quadriceps sets assisted by the contralateral leg are used and patients are allowed immediate weightbearing as tolerated. At 7 to 10 days, range of motion in a rehabilitative knee brace is increased to 0° to 70°. Quadricep extension exercises with active range of motion from 70° to 45° without weights and isometric hamstring exercises are instituted. At 21 to 24 days, range of motion is increased from 0° to 90° and a brace is worn for all activities except range of motion exercises. We strive for full extension with daily physical therapy if this is not present. Quadricep muscle sets are increased to 5 pounds maximum resistance for 90° to 45° with weightbearing to tolerance. At 5 weeks, the brace is off except during activities that put the patient at risk of injury. Quadricep sets from 45° to 90° with up to 15 pounds of resistance and full weightbearing is allowed in addition to swimming and stationary bicycle exercises. At 8 weeks, range of motion is full with no brace being worn. Unilateral quadricep exercises 90° to 45° with a stationary bike are used. At 12 weeks, full isotonic exercises with a quadriceps program, cycling, and half-speed jogging, are allowed, At 4 months, running in a straight line is allowed and the first Cybex examination is performed. Finally, at 8 months we allow a return to sports if Cybex testing shows 90% of normal strength is restored. This study serves as a long-term and complete evaluation of a relatively uniform population having undergone a specific reconstruction procedure. It offers the orthopaedist data and an experimental protocol to compare with other treatment modalities for the ACL deficient knee. Finally, the clinician may predict how an individual will fair with similar autogenous reconstructions. in

CONCLUSIONS · ACL reconstruction with the patellar tendon graft can result in a clinically stable and functional knee. Moreover, the result does not deteriorate with time.

ACKNOWLEDGMENT The authors appreciate the statistical assistance of Bryan Slinker, DVM, PhD.

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