Arthroscopic meniscectomy in the anterior cruciate ligament—deficient knee

Arthroscopy: TheJournalof Arthroscopicand RelatedSurgery3(1):59-65

Published by RavenPress © 1987ArthroscopyAssociationof North America

Arthroscopic Meniscectomy in the Anterior Cruciate Ligament-Deficient Knee Sean T. Hanley and Russell E Warren

Abstract: Patients with injury to the anterior cruciate ligament (ACL) frequently develop tears of the menisci. Removal of the meniscus, while relieving some complaints, may increase the patient's instability. To evaluate our success and quantify the reasons for failure, we evaluated 48 patients who underwent arthroscopic partial meniscectomy from 1979 to 1982. Patients were evaluated as to their subjective complaints, scored on a 100-point knee evaluation, and evaluated with standing x-rays. In addition, measurement using the KT-1000 knee arthrometer was made to assess the degree of tibial translation. Follow-up averaged 32 months, with a range of 24-50. At followup, 29 patients (60%) were judged to be clinical successes with resolution of their complaints and no aggravation of their instability. Nineteen patients (40%) were judged to be clinical failures in that their complaints persisted (14 patients) or ACL reconstruction was required (5 patients). Eight patients noted some increase in their instability, and three required a repeat meniscectomy. Arthroscopic partial meniscectomy can be a useful procedure in some patients with injury to the ACL. Patients more likely to do well are those with a torn medial meniscus with a chief complaint of locking. Examination would demonstrate a mild pivot shift, absence of generalized ligamentous laxity, and an anterior tibial translation difference of less than 5 ram. Key Words: ACL insufficiency-Laxity--Pivot shift--KT 1000.

Meniscus damage has frequently been associated w i t h r u p t u r e o f the a n t e r i o r c r u c i a t e l i g a m e n t (ACL). In a study of 113 patients with acute hemarthrosis of the knee, D e H a v e n reported that 65% of patients with an A C L injury also had a torn meniscus (1). W a r r e n and M a r s h a l l r e p o r t e d that c h r o n i c r u p t u r e o f the A C L is a s s o c i a t e d with damage to the menisci in 90% of cases at the Hospital for Special Surgery (HSS) (2). In both acute and chronic rupture of the A C L , the physician is faced with a difficult decision regarding the advisability and type of surgery. At the Sports Medicine Clinic of the HSS, we have observed that in many patients, total medial menisc e c t o m y in the ACL-deficient knee appears to increase the symptoms of instability. L e v y et al., in an anatomic selective cutting series, showed the medial meniscus to be an important secondary restraint to anterior tibial displacement in the A C L deficient knee (3). Paterson and Trickey recently

Editor's comments: Considering the morbidity of

cruciate reconstruction and the unpredictable results, this paper should be very helpful in providing information to orthopedic surgeons regarding who should have ACL reconstruction and who should have simple partial meniscectomy. Unfortunately, in this paper, no information is provided on the state of the articular cartilage at the time of surgery, which is what, in large measure, will determine the ultimate outcome of the surgery. Patients in whom there is simultaneous injury to the meniscus, cruciate ligament, and the articular cartilage have a worse prognosis than those in whom the articular cartilage is spared initially.

From the Hospital for Special Surgery, New York, New York, U.S.A. Address correspondence and reprint requests to Dr. S. T. Hanley, 48 Gilman Street, Portland, ME 04102, U.S.A.

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S. T. H A N L E Y A N D R. F. W A R R E N

reported on a group of 40 patients with unstable knees due to a combination of meniscal tear and rupture of the ACL. They found that symptoms of "instability" were cured by meniscectomy alone in over 50% of the patients (4). The goal of this study was to determine ways of distinguishing between those patients who are likely to obtain relief of symptoms after partial arthroscopic meniscectomy and those patients who would be better served by ACL repair and/or reconstruction in combination with meniscus surgery. MATERIAL AND METHODS A retrospective study was undertaken to evaluate patients with an ACL-deficient knee who underwent arthroscopic partial meniscectomy. There were 13 female and 15 male patients in the study group. The ages ranged from 19 to 58, with a mean of 30.4 years. There were 20 right knees and 25 left knees. Twenty-seven patients underwent partial medial meniscectomy, 13 underwent partial lateral meniscectomy, and 8 underwent both medial and lateral meniscectomy. The distribution of meniscus pathology is shown in Table 1. The interval from original injury to surgery ranged from 1 month to 13 years, With an average of 41 months. Twenty-seven patients had an interval from injury to surgery of less than 12 months. Follow-up was from 24 to 50 months, with a mean of 32 months. The requirements for inclusion in the study were arthroscopic verification of an absent ACL, no prior operative ACL treatment, and no significant other ligamentous injury or instability to the involved knee. During the period of 1979-1982, patients were selected for meniscectomy alone if their symptoms of instability were mild :with infrequent episodes of giving way. In particular, the pivot shift was utilized to exclude patients in whom the shift mimicked their complaints. Also included were those patients who for personal reasons refused ACL reconstruction. Arthroscopic meniscus repair during this period was combined with open ACL reconstruction; patients treated with this approach were excluded from this study. In general, the patients selected tended to be slightly older and were willing to modify their athletic activity. From 1979 to 1982, 62 patients met these criteria, and 48 patients were contacted and seen in followup by the authors. All patients completed a detailed questionnaire involving symptomatology and acArthroscopy, Vol. 3, No. 1, 1987

T A B L E 1. M e n i s c a l p a t h o l o g y

B u c k e t handle Anterior third Middle third Posterior horn Total

Medial

Lateral

26 0 1 8 35

3 7 5 6 21

tivity level, with emphasis on their subjective knee rating. All patients underwent a thorough physical examination including KT-1000 testing (5) and submitted to anterior-posterior standing radiographs of both knees. In an attempt to objectively rate results, all knees were tested and scored on the HSS 100-point normal knee diagnostic score sheet (see Appendix). Twenty-five points were awarded for a symptomfree knee with deductions for those problems causing pain, swelling, locking, or giving way. Twenty points were awarded for function including sports activity. Forty-five points were awarded for normal physical examination including ligamentous stability. Ten points were awarded for a functional examination. A special attempt was made to grade ligamentous instability using a 3 + system. Side-to-side differences were estimated, with 1 + representing a 1-5mm difference, 2 + representing a 5-10-mm difference, and 3 + representing a 10-15-ram difference. The pivot shift was also evaluated on a 3 + scale. A symptomatic grinding sensation without a definite slip was awarded 0.5 points, a definite but small slip 1 + , a moderate slip 2 + , and a large slip with actual transient locking 3 +. Generalized ligamentous laxity was estimated by testing for elbow hyperextension, metacarpo-phalangeal joint hyperextension, and the ability to touch the thumb to the forearm passively. One point was awarded for elbow h y p e r e x t e n s i o n greater than 0°, one point for MP hyperextension of 80 ° or greater, and one point for the ability to touch the thumb to the forearm passively. Standing AP roentgenograms were evaluated and compared at followup for changes as described by Fairbank (6). These changes included marginal osteophyte formation, generalized flattening of the marginal half of the femoral condyle, and joint space narrowing. Patients were graded and grouped from 0 (normal roentgenogram) to 4 (frank osteoarthritis) based on the severity of these roentgenographic changes.

M E N I S C E C T O M Y I N THE A C L - D E F I C I E N T K N E E

Clinically, rupture of the ACL, as well as a meniscal tear, was suspected preoperatively in all patients. The possibility of ACL reconstruction was discussed with all patients and, for medical or personal reasons, a decision was made to proceed with arthroscopic meniscectomy alone. All patients were admitted to the hospital on the day prior to surgery. Surgery was performed under general anesthesia. A tourniquet was utilized for hemostasis. Average tourniquet time was 68 rain. Standard arthroscopic portals were utilized. There were no major p o s t o p e r a t i v e complications. Average hospital stay was 2.5 days. All patients were begun on vigorous quadriceps and hamstring rehabilitation postoperatively. RESULTS Twenty-nine patients (60%) rated their involved knee at follow-up as normal or improved and were subjectively satisfied with their knee function. They were designated a clinical success (Group I). Their average age was 32. Their knee diagnostic scores (KDSs) ranged from 92 to 60 with an average of 82. Five patients considered their knees to be normal. Nineteen patients were judged to be clinical failures (Group II). Fourteen patients in Group II described their knee as " w o r s e " or "unchanged" following meniscectomy. Five patients required ACL reconstruction during the follow-up period b e c a u s e of increased s y m p t o m s of instability. Three patients in Group II underwent repeat lateral meniscectomy because of persistent symptoms of pain and/or locking. One patient underwent a high tibial osteotomy because of increased pain and progressive varus deformity. The average age of the failure group was 31, and the average postoperative KDS was 52. Sixteen of 19 patients in this group complained of troublesome giving way of their knee, while eight patients felt both the severity and frequency of their symptoms of giving way had increased postmeniscectomy. The distribution of meniscal pathology within the two groups is shown in Table 2. An attempt was made to correlate preoperative symptomatology with postoperative results. Each patient was asked to designate his or her major preoperative complaint as locking, giving way, or generalized pain and to rate the severity. In Group I, 79% complained of locking preoperatively, while only 44% specifically complained of giving way. In

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T A B L E 2. Distribution o f meniscal pathology in

Groups 1 and H Medial

Bucket handle Anterior third Middle third Posterior horn Total

Lateral

I

II

I

II

18 0 t 5 24

8 0 0 3 11

3 1 2 3 9

0 6 3 3 12

contrast, of those patients judged to be a clinical failure, only 27% complained of locking preoperatively, while 45% preoperatively complained of troublesome giving way, and 36% complained of pain. In an attempt to identify features in common that could permit prediction of the likely response to meniscectomy alone, a further analysis of each group was made with regards to generalized ligamentous laxity, pivot shift, pre- and postoperative activity level, postoperative radiographic changes, and, finally, tibial translation as measured with the KT-1000 knee arthrometer (5). The distribution of generalized laxity in the two clinical groups is shown in Table 3. Thirty-six patients were found to have a laxity rating of 0 or 1. Their average age was 32, their postoperative KDS average was 74, and their average pivot shift was 1.2. Twelve patients had a laxity rating of 2 or 3. Their average age was 26, average KDS was 59, and pivot shift was 2.0. The distribution of preoperative pivot shift for the two groups is shown in Table 4. Seven patients were noted to have a preoperative pivot shift of 3 +. Six of seven were judged to be clinical failures while the remaining patient was not athletically active at follow-up. Postoperative radiographs revealed a significant progression of degenerative changes in both clinical groups. The distribution of these changes is shown

T A B L E 3. Distribution o f generalized laxity Laxity grade

Clinical success

Failure

0 1 2 3

13 13 3 0

3 7 8 1

Data: laxity Groups 0 and I: average KDS, 73.72; laxity Groups II and III: average KDS, 59.33; T value, 2.780; number of patients, 48; p < 0.01.

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S. T. H A N L E Y A N D R. F. W A R R E N T A B L E 4. Distribution o f preoperative pivot shift

Pivot shift

Number of patients in Group I

Number of patients in Group II

Grind 1+ 2+ 3+

3 13 12 1

1 5 7 6

Data: subjective Groups I and II: average preoperative pivot shift, t.43; subjective Groups III and IV: average preoperative pivot shift, 1.82; T value, !.801; number of patients, 48; p < 0.1.

T A B L E 6. Stress levels of various sports categories

A

B

C

D

Basketball Volleyball Gymnastics

Professional dance Football Rugby Squash Handball Tennis (singles) Downhill skiing Soccer

Cross-country skiing Jogging Tennis (doubles) Swimming Bicycling Fencing Boxing Golf

No sports

Key: A, very stressful; B, moderately stressful; C, mildly stressful; D, no sports activities.

in Table 5. There was not a strict correlation between subjective result and radiographic grade. However, those patients with Grade III and IV changes had a significantly lower KDS (56 versus 73) and tended to be less active. All patients were involved in recreational athletic activity preoperatively. At follow-up, five patients were no longer involved in any form of athletic activity. An attempt was made to rate the degree of stress placed on the knee in various recreational sports, using as a criterion the demands for sudden changes in momentum and direction, which place the ACL-deficient knee at risk. The various sports categories and their stress rating are shown in Table 6. The distribution of patients within these groups both preinjury and postmeniscectomy is shown in Table 7. Although no correlation between preinjury activity level and subjective or objective result could be found, there did appear to be a strong correlation between postmeniscectomy activity and both subjective and objective assessment. Anterior tibial translation was measured at follow-up using the KT-1000 knee ligament arthrometer in all patients with the exception of the five patients who had undergone ACL reconstructive surgery. Comparing side-to-side differences at the 20-1b level, there was a direct correlation between subjective results and the magnitude of the difference. The average side-to-side difference in the clinical success group was 4.9 mm compared

with an average difference of 7.2 mm in the clinical failure group. Statistical analysis revealed this to be significant (p < 0.01). Interestingly, the maximal excursion of the uninjured knee demonstrated a significant increase in anterior tibial translation in the failure group; the average excursion of the uninjured knee in Group I was 5.5 compared with an average excursion of 6.9 for the uninjured knee in Group II. These results were found to be statistically significant (p < 0.01). DISCUSSION Sixty percent of patients in our study group were subjectively improved by partial meniscectomy at an average follow-up of 32 months. Only 8 of 48 patients felt the frequency and/or severity of their s y m p t o m s of giving way had increased in the follow-up period. Paterson and Trickey (4) related subjective poor results in their study to posterior horn tears and subjective good results to buckethandle tears. In contrast, we were unable to correlate meniscal pathology with the subjective results when a partial arthroscopic meniscectomy was perT A B L E 7. Activity levels pre- and postmeniscectomy Activity level A

B

C

D

Premeniscectomy Number of patients Average subjective score Average KDS

23 76 72

20 78 71

5 67 62

0

Postmeniscectomy Number of patients Average subjective score Average KDS

8 88 84

17 75 78

18 58 63

6 40 48

T A B L E 5. Distribution of degenerative changes

Radiographic grade 0 I II III IV

Arthroscopy, Vol. 3, No, 1, 1987

Number of patients in Group I

Number of patients in Group II

4 13 10 2

2 8 3 4 2

See Table 6 for explanation of activity levels.

M E N I S C E C T O M Y I N THE ACL-DEFICIENT K N E E formed. It is our feeling that a partial meniscectomy is a more selective procedure that may reduce a patient's complaints without increasing instability (7). It is i m p o r t a n t w h e n evaluating patients with chronic A C L insufficiency to attempt to judge the relative roles of the menisci and the cruciate ligament in producing symptoms. In our study, those patients with clear symptoms o f locking tended to do significantly better. P h y s i c a l e x a m i n a t i o n also aids in identifying those patients at risk for developing progressive instability. If the pivot shift test mimics the patient's complaints or if the patient d e m o n s t r a t e s a 3 + pivot shift, meniscectomy alone probably will not significantly i m p r o v e the p a t i e n t ' s c o m p l a i n t s . Generalized ligamentous laxity seems to be associated with an increased pivot shift and progression of instability. The KT-1000 knee ligament arthrometer aids in quantitating instability and may prove helpful in identifying those patients at risk for developing progressive symptomatic instability. CONCLUSION Over the past 4 years, we have altered our approach to meniscus repair in the ACL-insufficient knee and have been willing to perform meniscus repair without reconstruction at times, depending on the patient's symptoms and activity demands. It is

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our hope that use o f these meniscectomy data will improve our results in patient selection for meniscus repair. Arthroscopic partial m e n i s c e c t o m y relieved the major clinical complaints in approximately 60% of patients with an ACL-deficient knee. Careful attention to preoperative symptoms and physical examination will help identify those patients who will be best served by A C L reconstruction rather than meniscal excision. In the majority of patients, partial arthroscopic m e n i s c e c t o m y did not increase the symptoms of instability. REFERENCES 1. Dehaven KE. Diagnosis of acute knee injuries with hemarthrosis. A m J Sports M e d 1980;8:9. 2. Warren RF, Marshall JL. Injuries of the anterior cruciate and medial collateral ligaments of the knee. Clin Orthop 1918;136:191. 3. Levy M, Torzilli P, Warren R E The effect of medial meniscectomy on anterior posterior knee motion. J Bone Joint Surg 1982;64A:883. 4. Paterson RWN, Trickey EL. Meniscectomy for tears of the meniscus combined with rupture of the anterior cruciate ligament. J Bone Joint Surg 1983;65B:388-90. 5. Malcolm LL, Daniel DM, Stone ML, Sachs R. The measurement of anterior knee laxity after ACL reconstructive surgery. Ctin Orthop t985;196:35. 6. FairbankTJ. Knee joint changes after meniscectomy. J Bone Joint Surg 1948;30B:664. 7. Dandy DJ, Flanagan JE Arthroscopy and the management of the ruptured anterior cruciate ligament, Clin Orthop 1982;167:43.

APPENDIX: NORMAL K N E E DIAGNOSTIC SCORE S H E E T Age

Name Score Symptoms (5) ~n pts. Swelling: No ........................ 2 Yes ........................ 0 Locking: No ........................ 3 Yes ........................ 0 Giving Way (20) Severity: None ..................... 10 Transient ................ 8 Recovery lday ......... 6 Recovery lwk ......... 2 Recovery lwk ......... 0 Frequency: None ..................... 10 1 per yr .................. 8 2-6 per yr .............. 6 1 per month ............ 4 1 per week .............. 2 Daily ..................... 0

pre

6mo

Left lyr 2yr

3yr

4yr

pre

Sex: 6mo

Right lyr 2yr

M 3yr

F 4yr

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S. T. H A N L E Y

Score in p t s . F u n c t i o n (20)

Adl: Full r e t u r n .............. R e t u r n w / l i m i t a t i o n ... Different job ........... U n a b l e d u e to k n e e ..

6 4 2 0

Sports or Strenuous Work: F u l l r u n & c u t . . . . . . . . . 14 L e s s s t r e s s f u l . . . . . . . . . . 10 Partial r e t u r n ........... 6 No return ............... 0 E x a m i n a t i o n (45)

ROM: Normal .................. Limited flexion or ext .................. Both ......................

3

0

Effusion: N o ........................

4

Yes ........................

0

1

Thigh Circumference: Equal to 1 cm difference ............ t cm difference ........ Lachman: ( n o t e e n d p t ) Neg ....................... 1 + (0-5mm) ........... 2+ (5-10ram) ......... 3+ (10-15mm) ........

2 0 4 3 2 0

Ant. Drawer: Neg ....................... 1 + (l-5mm) ........... 2+ (5-10ram) ......... 3+ (10-15mm) ........

2 2 0 0

Post. Drawer: Neg ....................... 1 + (0-5mm) ........... 2+ (5-10mm) ......... 3+ (10-15mm) ........

5 3 2 0

Pivot Shift: Neg. (or equal to u n a f f e c t e d side) .... 10 Grind ..................... 8 1+ ........................ 4 2+ ........................ 0

MCL: Normal .................. 1+ ........................ 2+ ........................ 3+ ........................

5 3 2 0

LCL: Normal .................. 1+ ........................ 2+ ........................ 3+ ........................

5 3 2 0

Reverse Pivot Shift: Neg ....................... Pos ........................

Arthroscopy, Vol. 3, No. 1, 1987

5 0

pre

6mo

A N D R . F. W A R R E N

Left lyr 2yr

3yr

4yr

pre

6mo

Right lyr 2yr

3yr

4yr

MENISCECTOMY IN THE ACL-DEFICIENT KNEE

Score in pts.

pre

6too

Left lyr 2yr

65

Right 3yr

4yr

pre

6mo

lyr

2yr

3yr

4yr

Functional E x a m (10)

Standing Forward Jump % Diff. Between Legs: 90 - 100% . . . . . . . . . . . . . . . . 75-90% .................. 50-75% .................. 50% . . . . . . . . . . . . . . . . . . . . . . .

10 7 5 0

Score:

Deductions Derotation Brace: S e c u r i t y o f mind ...... Due to instability .....

2 4

Pain: None ..................... O c c a s i o n a l aching .... After stressful sports ................. A f t e r daily activities Continuous .............

0 2 5 8 10

rlbtal Score: (lO0 = Normal)

Arthroscopy, Vot. 3, No. 1, 1987