Combined Injuries of the Anterior Cruciate and Medial Collateral Ligaments of the Knee

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1 Copyright 1996 by The Journal of Bone and Joint Surgery, Incorporated Combined Injuries of the Anterior Cruciate and Medial Collateral Ligaments of the Knee EFFECT OF TREATMENT ON STABILITY AND FUNCTION OF THE JOINT* BY DIANE HILLARD-SEMBELL, M.D.T, DALE M. DANIEL, M.D.FC MARY LOU STONE, R.P.T., BARBARA E. DOBSON, L.V.N.8, AND DONALD C. FITHIAN, M.D., SAN DIEGO, CALIFORNIA Investigation performed at the San Diego Kaiser Medical Center, San Diego ABSTRACT: We performed a retrospective study of sixty-six patients (forty-one male and twenty-five female) who had a combined injury of the anterior cruciate and medial collateral ligaments. Our purpose was to determine the prevalence of late valgus instability of the knee. The mean age of the patients was thirtyfive years (range, sixteen to sixty-three years). The mean follow-up interval was forty-five months (range, twenty-one to 108 months). Twenty patients had been injured while snow-skiing; twenty-four, during other sports activities; seven, in a motor-vehicle accident; and the remaining fifteen, during activities of daily living. Eleven patients had reconstruction of the anterior cruciate ligament and repair of the medial collateral ligament, thirty-three had reconstruction of only the anterior cruciate ligament, and twenty-two were managed non-operatively. There was no evidence of valgus instability on clinical examination at the most recent follow-up visit. However, there was evidence of instability on stress roentgenograms of the knee in eight (13 per cent) of sixty patients. With the numbers available, we could detect no relationship between the presence of valgus instability and the method of treatment of the ligamentous tears (p > 0.4). We also compared the results for twenty-one of the thirty-three patients who had a combined ligamentous injury and reconstruction of only the anterior cruciate ligament with those for thirty-seven patients who had reconstruction of an isolated tear of the anterior cruciate ligament. After a mean follow-up interval of thirty-five months (range, twenty-one to sixty-six months), there was no difference in the anterior dis- *One or more of the authors has received or will receive benefits for personal or professional use from a commercial party related directly or indirectly to the subject of this article. Funds were received in total or partial support of the research or clinical study presented in this article. The funding source was the Southern California Kaiser Permanente Research Foundation. tspringfield Clinic, 1025 South Seventh Street, Springfield, Illinois ^Deceased. Southern California Permanente Medical Group, 4647 Zion Avenue, San Diego, California placement, impairment of function, level of participation in sports activities, results of the one-leg-hop for distance test, or strength as determined by testing on a Cybex machine. On the basis of the findings in this study, we believe that, when there is mild or moderate valgus instability, an injury of the medial collateral ligament does not need to be repaired when the anterior cruciate ligament is repaired after a combined ligamentous injury. There is general agreement that an isolated injury of the medial collateral ligament heals satisfactorily without operative intervention" 12 ' 25. Injury of the anterior cruciate ligament may result in anterior instability, which may prevent the patient from participating in sports activities involving jumping, abrupt lateral movements, and cutting (planting a foot, while running, in order to change direction); therefore, some authors have recommended reconstruction of the anterior cruciate ligament for those who participate in such sports activities 23. However, there has been little consensus as to the best treatment for combined injuries of the medial collateral and anterior cruciate ligaments We performed this retrospective review of patients who had a combined ligamentous injury to determine the prevalence of late valgus instability. Some authors have reported an increased prevalence of instability of the knee in patients who have an injury of the anterior cruciate and medial collateral ligaments, but valgus instability was not mentioned as a separate entity 14 ' Warren and Marshall 4445 noted that the giving-way in these patients probably represented anterior instability; they stated that isolated valgus instability does not produce giving-way. We also tried to determine whether operative treatment of a tear of the medial collateral ligament decreased the prevalence of valgus instability. Numerous authors have recommended operative treatment of both ligaments. However, we know of no studies that have supported the thesis that repair of the medial collateral ligament decreases late valgus instability or symptoms associated with the knee. In contrast, stiffness of the knee has been reported after operative VOL. 78-A, NO. 2, FEBRUARY

2 170 DIANE HILLARD-SEMBELL, D. M. DANIEL, M. L. STONE, B. E. DOBSON, AND D. C. FITHIAN repair of the medial collateral ligament 13<i. To answer the question of whether an injury of the medial collateral ligament alters the results of reconstruction of the anterior cruciate ligament, we compared the results of reconstruction of only the anterior cruciate ligament in patients who had a combined ligamentous injury with the results in patients who had reconstruction of an isolated injury of the anterior cruciate ligament. Materials and Methods We reviewed the medical records of eighty-six patients who had an injury of the anterior cruciate and medial collateral ligaments. Fifty-one patients had had an operation performed by one of three staff orthopaedic surgeons, including one of us (D. M. D.), between December 1981 and July 1990, and thirty-five patients had been managed non-operatively between March 1987 and July Sixty-six patients returned for the follow-up evaluation. Eleven patients could not be located, five patients lived too far away to return, and four patients in the San Diego area declined to come in for an evaluation. The mean follow-up interval was fortyfive months (range, twenty-one to 108 months). Twenty patients had been injured while snow-skiing; seven, playing soccer; five, playing baseball; four, playing basketball; three, playing football; five, during other sports activities; seven, in a motor-vehicle accident; and the remaining fifteen, during activities of daily living. Eleven patients (ten male and one female), who were a mean of thirty-three years old (range, nineteen to forty-nine years old), had reconstruction of the anterior cruciate ligament and repair of the medial collateral ligament within two weeks after the injury. Thirtythree patients (twenty-one male and twelve female), who were a mean of thirty-one years old (range, sixteen to fifty-nine years old), had reconstruction of only the anterior cruciate ligament. The operation was performed within two weeks after the injury in twenty-one patients, three to eight weeks after the injury in eight, and more than eight weeks after the injury in four. Twenty-two patients (ten male and twelve female), who were a mean of forty-two years old (range, twentyseven to sixty-three years old), were managed nonoperatively. To be included in the study, the patients had to have been evaluated within fourteen days after the injury. The injury of the medial collateral ligament had to be grade II or III that is, valgus instability as determined on the abduction stress test with the knee in 20 degrees of flexion 6. A grade-ii injury was defined as opening of the joint space that was three to five millimeters greater in the injured knee than in the contralateral (uninjured) knee, with a firm end point. A grade-ill injury was characterized by opening of the joint space that was more than five millimeters greater in the injured knee, with no detectable end point. Disruption of the anterior cruciate ligament was diagnosed if an arthrometer (KT-1000; MedMetric, San Diego, California) showed a difference in displacement of more than 2.5 millimeters between the injured and uninjured knees on the manual maximum test 8. Patients were excluded if they had had a previous injury or operative intervention in either knee, a fracture around the knee (with the exception of an avulsion fracture), or varus or posterior instability. Operative treatment was recommended for patients who were less than thirty years old and involved in sports activities on a regular basis. Non-operative treatment consisted of immobilization in a cast or brace for two to four weeks followed by the use of a brace that permitted a range of motion for two to four weeks. The patients then followed a home exercise program. They were advised not to participate in sports involving running or cutting for a minimum of three months after the injury and to return to their previous level of activity only when they had a full range of motion of the knee and there was no effusion. Before 1987, nine patients who had a combined ligamentous injury with a grade-ill injury of the medial collateral ligament had repair of both ligaments and twelve patients who had a combined injury with a grade- II injury of the medial collateral ligament had reconstruction of only the anterior cruciate ligament. Since 1987, one of us (D. M. D.) reconstructed the anterior cruciate ligament only in thirteen patients who had a FIG. 1-A FIG. 1-B Figs. 1-A and 1-B: Varus/valgus device used to determine the amount of opening of the medial joint space (Stress-Ray; MedMetric, San Diego, California). The knees are positioned in 20 degrees of flexion (Fig. 1-A), a strap holds the thighs together, and a foot support cradles the foot to resist axial rotation of the limb (Fig. 1-B) while an abduction moment is applied to both limbs. THE JOURNAL OF BONE AND JOINT SURGERY

3 COMBINED INJURIES OF THE ANTERIOR CRUCIATE AND MEDIAL COLLATERAL LIGAMENTS OF THE KNEE 171 FIG. 2 Anteroposterior roentgenogram of the injured and contralateral knees, made while an abduction moment of 25.8 newton-meters was applied. Lines were drawn tangential to the femoral condyles and tibial plateaus. The distance between the tangential lines on the medial and lateral aspects of the knee was measured. In this patient, the medial joint space was eight millimeters in the uninjured knee and twelve millimeters in the injured knee. combined injury, and two other surgeons reconstructed the anterior cruciate ligament and repaired the medial collateral ligament in two patients who had a combined injury and reconstructed the anterior cruciate ligament only in eight. Since 1987, the technique of reconstruction of the anterior cruciate ligament with use of a patellar-ligament autogenous graft was the same for patients with or without an injury of the medial collateral ligament 7. To determine if an injury of the medial collateral ligament alters the results of reconstruction of the anterior cruciate ligament, we compared two groups of patients who had reconstruction of only the anterior cruciate ligament with a patellar-ligament graft within ninety days after the injury. One group consisted of twenty-one of the thirty-three patients who had a combined ligamentous injury, and the other group included thirty-seven patients who had an isolated tear of the anterior cruciate ligament. We had identified fifty-four patients who had an isolated tear, but seventeen chose not to return for evaluation. Both groups had reconstruction within the same time-period, and both followed the same rehabilitation program postoperatively. The evaluations were performed by three of us (D. H.-S., M. L. S., and B. E. D.), who were not the operating surgeons. The evaluation included a questionnaire to assess symptoms such as pain, swelling, and giving-way of the extremity and to elicit information regarding the level of impairment during walking, climbing stairs, kneeling, squatting, running, jumping, cutting, and lateral motion. The total number of hours spent each year in sports activities was determined with the aid of a questionnaire 913. Sports were classified according to the description by the International Knee Documentation Committee 913. A level-i sport involves jumping and cutting (for example, basketball), a level-ii sport involves lateral motion (for example, racquet sports), and a level-ill sport does not involve jumping, cutting, or lateral motion (for example, jogging or swimming). Functional tests consisted of the one-leg-hop for distance test 9 " and strength-testing with the Cybex machine 9 (Lumex, Bayshore, New York). The hop index represents the distance that the patient could hop with the limb that had the injury compared with that for the contralateral limb; 90 per cent or more represented full function of the knee. Strength was tested at 60 degrees per second in both knees; 80 per cent or more represented full function of the knee. The range of motion and stability of the joint were determined clinically. Anteroposterior instability was measured with the KT-1000 arthrometer (MedMetric). The amount of opening of the medial joint space was determined clinically by the application of a valgus stress to the knee in 20 degrees of flexion. Roentgenograms were made with both extremities held in a device (Stress-Ray; MedMetric) that positions the knee in 20 degrees of flexion and applies an abduction moment of 25.8 newton-meters (Figs. 1-A and 1-B). The opening of the joint space on the roentgenogram was measured in a manner similar to that described by Kennedy and Fowler 27 (Fig. 2). Lines were drawn tangential to the femoral condyles and tibial plateaus, and the distance between the tangential lines on the medial and lateral aspects of the knee was measured. The stress roentgenograms were made for sixty of the sixty-six patients. The data were analyzed with use of statistical software (Minitab; State College, Pennsylvania). For contin- VOL. 78-A, NO. 2, FEBRUARY 1996

4 172 DIANE H1LLARD-SEMBELL, D. M. DANIEL, M. L. STONE, B. E. DOBSON, AND D. C. FITHIAN TABLE I RESULTS OF RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT WITHIN NINETY DAYS AFTER THE INJURY Duration of follow-up (mos.)* Age (yrs.)* Time spent in sports (hrs. per yr.)* Before injury After injury Participation in a level-i or II sportt Before injury After injury Joint-space opening determined with arthrometer 89-N test Mean difference (mm) >2.5-mm difference! 134-N test Mean difference (mm) >2.5-mm difference! >5.0-mm difference! Manual maximum test Mean difference (mm) >5.0-mm difference! Difference in joint flexion (degrees)* Flexion contracture (degrees)* One-leg-hop test (per cent of uninjured)* Strength of quadriceps (per cent of uninjured)* Strength of hamstrings (per cent of uninjured)* No difficulty climbing! No difficulty kneeling! No difficulty running! No difficulty cutting! Isolated Injury (N = 37) 36 (23 to 66) 28 (1.5 to 46) 355 (0 to 1040) 258 (0 to 1250) 32 (86) 19 (51) 1.5 9(24) (38) (8) 3 (0 to 20) 2 (0 to +9) 92 (71 to 114) 86 (55 to 125) 98 (87 to 136) 31 (84) 15 (41) 25 (68) 29 (78) *The value is given as the mean, with the range in parentheses.!the value is given as the number of patients, with the percentage in parentheses. Combined Injury (N = 21) 31 (21 to 53) 29 (16 to 43) 329 (50 to 955) 202 (0 to 660) 15(71) 9(43) 1.0 4(19) 1.5 7(33) (14) 2 (o to: 15) 2 (-4 to i+6) 89 (80 to 107) 88 (55 to 105) 98 (82 to 120) 17 (81) 10(48) 13 (62) 16 (76) uous variables, one-way analysis of variance was used to compare the groups. For categorical variables, chisquare analysis was used to compare the groups. Results Valgus Instability At the initial examination, the injury of the medial collateral ligament was grade II in thirty-seven patients and grade III in twenty-nine. In four patients who had a grade-ill injury, the opening of the joint space was estimated to be more than ten millimeters (range, eleven to fifteen millimeters) greater in the injured knee. In ten patients, the opening of the joint space was three to nine millimeters (mean, 4.5 millimeters) greater in the injured knee, according to roentgenograms that were made with the patient under anesthesia and the knee subjected to a valgus stress with use of an abduction moment of 12.9 newton-meters. At the follow-up clinical examination, the mean opening of the medial joint space was 0.6 millimeter (range, -1 to +2 millimeters) greater in the injured knee. On stress roentgenograms (made for sixty patients), the mean medial joint space was 7.0 millimeters (range, two to twelve millimeters) in the uninjured knee and 8.3 millimeters (range, four to fourteen millimeters) in the injured knee, a difference of 1.3 millimeters (range, -3 to +6 millimeters). Eight patients (one with a grade-ii injury and seven with a grade-ill injury of the medial collateral ligament) had an opening of the medial joint space that was more than 2.5 millimeters greater in the injured knee: four of these patients had not had an operation, two had had reconstruction of only the anterior cruciate ligament, and two had had reconstruction of the anterior cruciate ligament and repair of the medial collateral ligament. With the numbers available, we could not detect a significant effect of the method of treatment of the combined ligamentous injury on late valgus instability (p > 0.4). Complications There were no infections. Four patients needed manipulation of the knee under anesthesia to regain motion of the joint: two had had repair of the medial collateral ligament, one had had reconstruction of the anterior cruciate ligament only, and one had been managed non-operatively. The mean flexion deficit at the time of follow-up was 6 degrees (range, 0 to 20 degrees) in the eleven patients who had had both ligaments repaired, 2 degrees (range, 0 to 15 degrees) in the thirty-three patients who had had reconstruction of the anterior cruciate ligament only, and 0 degrees in the twenty-two patients who had been managed non-operatively (p < THE JOURNAL OF BONE AND JOINT SURGERY

5 COMBINED INJURIES OF THE ANTERIOR CRUCIATE AND MEDIAL COLLATERAL LIGAMENTS OF THE KNEE ). The mean flexion contracture for all patients was 1 degree, with no difference among the groups. Function At the time of follow-up, the number of hours of participation in sports activities each year (mean, 192) had decreased in all groups compared with the number before the injury (mean, 293). The number of patients who participated in a level-i or II sport for fifty hours or more each year decreased from forty-six to twenty-six. There was no significant difference among the treatment groups. The patients were asked about disability with walking, climbing, squatting, running, jumping, and cutting. The only difference between the operatively treated groups and the non-operatively treated group was with cutting; twelve (55 per cent) of the twenty-two patients who had been managed nonoperatively had difficulty cutting, compared with twelve (27 per cent) of the forty-four patients who had been managed operatively. Reconstruction of the Anterior Cruciate Ligament for a Combined Injury Compared with Such Reconstruction for an Isolated Tear For the thirty-seven patients who had an isolated tear of the anterior cruciate ligament, the mean followup interval was thirty-six months (range, twenty-three to sixty-six months) and the mean age was twenty-eight years (range, fifteen to forty-six years). The patients participated in sports activities for a mean of 355 hours (range, zero to 1040 hours) each year before the injury and 258 hours (range, zero to 1250 hours) each year after the injury. Eighty-six per cent (thirty-two) of the patients participated in a level-i or II sport before the injury, and 51 per cent (nineteen) did so after the injury. For the twenty-one patients who had a combined ligamentous injury, the mean follow-up interval was thirty-one months (range, twenty-one to fiftythree months) and the mean age was twenty-nine years (range, sixteen to forty-three years). The patients participated in sports activities for a mean of 329 hours (range, fifty to 955 hours) each year before the injury and 202 hours (range, zero to 660 hours) each year after the injury. Seventy-one per cent (fifteen) of the patients participated in a level-i or II sport before the injury, and 43 per cent (nine) did so after the injury (Table I). The mean difference in flexion of the joint between the injured and contralateral knees was 3 degrees (range, 0 to 20 degrees) in the patients who had an isolated tear and 2 degrees (range, 0 to 15 degrees) in those who had a combined injury. The mean flexion contracture was 2 degrees in both groups. The mean one-leg-hop index was 92 per cent (range, 71 to 114 per cent) of the value for the uninjured limb for the patients who had an isolated tear and 89 per cent (range, 80 to 107 per cent) for the patients who had a combined injury. The mean strength of the hamstrings was 98 per cent (range, 87 to 136 per cent) of the value for the uninjured limb for the patients who had an isolated tear and 98 per cent (range, 82 to 120 per cent) for the patients who had a combined injury. The mean strength of the quadriceps was 86 per cent (range, 55 to 125 per cent) of the value for the uninjured limb for the patients who had an isolated tear and 88 per cent (range, 55 to 105 per cent) for the patients who had a combined injury (Table I). Eighty-four per cent (thirty-one) of the thirty-seven patients who had an isolated tear had no difficulty climbing, 41 per cent (fifteen) had no difficulty kneeling, 68 per cent (twenty-five) had no difficulty running, and 78 per cent (twenty-nine) had no difficulty cutting. Eighty-one per cent (seventeen) of the twenty-one patients who had a combined injury had no difficulty climbing, 48 per cent (ten) had no difficulty kneeling, 62 per cent (thirteen) had no difficulty running, and 76 per cent (sixteen) had no difficulty cutting (Table I). With the numbers available, none of the differences in stability or function were shown to be significant (p > 0.5). Discussion Studies of cadavera have shown that the primary restraint to anterior displacement is the anterior cruciate ligament ' 34. Sectioning of the medial ligamentous complex (the medial collateral ligament, medial capsular ligament, and posterior oblique ligament), with the anterior cruciate ligament left intact, does not result in an increase in anterior displacement; however, anterior displacement increases when the anterior cruciate ligament is also sectioned 42. The primary restraint to valgus instability is the medial collateral ligament 161 " 8, with the cruciate ligaments acting as secondary stabilizers of the knee"'. Therefore, sectioning of both structures increases anterior and valgus instability 42. It is believed that instability secondary to disruption of the anterior cruciate ligament may reduce the quality of healing of the medial collateral ligament, further increasing valgus instability 46. In studies of cadavera by Warren et al. 43, application of valgus stress to the knee in 30 degrees of flexion after sectioning of the superficial medial collateral ligament increased the distance between tibial and femoral reference points by three millimeters. When the entire medial ligamentous complex was cut, the distance increased by seven millimeters. Hughston et al. 20 recommended that the instability detected on the valgus stress test be considered mild when displacement was three to five millimeters, moderate when it was six to ten millimeters, and severe if it was more than ten millimeters. Those authors noted that the actual separation was not more than ten millimeters at the time of the operation in many knees, despite a preoperative rating of severe instability. Hughston 19 reported the results of repair in forty-one patients who had a disruption of the medial VOL. 78-A, NO. 2, FEBRUARY 1996

6 174 DIANE HILLARD-SEMBELL, D. M. DANIEL, M. L. STONE, B. E. DOBSON, AND D. C. FITHIAN collateral ligament and more than ten millimeters of valgus instability. He suggested non-operative treatment for mild or moderate valgus instability and repair for severe instability. In our study, we estimated the amount of opening of the medial joint space and compared this with the amount in the uninjured knee. Only four patients had a difference of more than ten millimeters of opening. The remaining patients had only mild or moderate instability. On the basis of the criterion that a difference of less than three millimeters represents stability, none of our patients had clinical evidence of valgus instability at the time of follow-up. Jokl et al. 24 evaluated twenty-eight patients who had been managed non-operatively for a combined tear of the anterior cruciate and medial collateral ligaments. Twenty patients had a good or excellent result (normal or nearly normal function of the knee with few if any symptoms) as determined with The Hospital for Special Surgery assessment form; roentgenograms or instrumented tests were not used to evaluate instability. Although it has been widely accepted that an isolated injury of the medial collateral ligament will heal satisfactorily without treatment ' 25, many believe that a combined injury is best treated with operative intervention and repair of all damaged structures ' ' 45. Ballmer et al. 4 and Shelbourne and Porter 40 reported good results after reconstruction of the anterior cruciate ligament and non-operative treatment of a tear of the medial collateral ligament. Ballmer et al. documented joint instability with roentgenograms. Shelbourne and Porter documented anterior instability with the KT-1000 arthrometer but did not document valgus instability. In an earlier study, we showed that 188 of 190 patients in whom displacement was more than 2.5 millimeters greater in the injured knee were found to have a tear of the anterior cruciate ligament arthroscopically 8. Noyes et al. 31 utilized measurements of anteriorposterior displacement with the KT-1000 arthrometer to classify function of the anterior cruciate ligament after revision procedures. Both knees were measured at an eighty-nine and 134-newton total anterior-posterior displacement force. The authors did not state whether the classification was made on the basis of the measurements obtained with the eighty-nine or 134-newton test. Greater displacement loads result in greater knee displacements, as has been seen in studies performed with eighty-nine and 200-newton loads 10, eighty-nine and 134-newton loads 35, and eighty-nine-newton and maximum displacement loads 135. When function of the anterior cruciate ligament is classified, the testing load should be identified 2-12 ' 27 ' 35 ' 41. Because the medial collateral ligament heals without treatment 32122, some authors have suggested that, when both ligaments are injured, reconstruction of the anterior cruciate ligament alone is sufficient, as the medial collateral ligament will heal spontaneously 4-39 ' 40. If reconstruction of the anterior cruciate ligament is to affect healing of the medial collateral ligament, presumably the repair needs to be performed within one to two weeks after the injury; however, the risk of postoperative stiffness when the anterior cruciate ligament is reconstructed within two to four weeks after the injury is well documented" Thus, the risk of postoperative stiffness must be weighed against the possible benefit from early correction of anterior instability. We know of no comparative clinical studies that have demonstrated that reconstruction of the anterior cruciate ligament improves healing of the medial collateral ligament. In an earlier study, we used roentgenograms to document valgus instability in twenty-four patients who had had repair of an isolated tear of the medial collateral ligament and in forty-one patients who had had repair of a combined ligamentous injury 10. The opening of the joint space was more than three millimeters greater in the injured knee in seven patients who had had repair of an isolated injury of the medial collateral ligament and in five patients in whom both ligaments had been repaired. Ballmer and Jakob 3 reported instability of three millimeters or more on roentgenograms of twelve of twenty patients who had been managed nonoperatively for an isolated injury of the medial collateral ligament. The subjective rating for all patients was good or excellent. Ballmer et al. 4 evaluated fourteen patients who had had a combined ligamentous injury and reconstruction of the anterior cruciate ligament. At the time of follow-up, twelve of the knees were stable and two had valgus instability of three to five millimeters. In the present study, only eight (13 per cent) of sixty patients had valgus instability according to roentgenograms. Operative treatment of both ligaments or of only the anterior cruciate ligament in a combined ligamentous injury did not alter the prevalence of late valgus instability. In addition, an injury of the medial collateral ligament did not alter the results of reconstruction of the anterior cruciate ligament performed within ninety days after the injury. NOTE: The authors thank Raymond Sachs, M.D., and John Murphy, M.D., for allowing us to evaluate their patients. References 1. 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