Meniscal tearing after ACL reconstruction

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1 Journal of Orthopaedic Surgery 2000, 8(1): Meniscal tearing after ACL reconstruction S Ichinohe, M Yoshida, H Murakami, H Takayama, S Izumiyama and T Shimamura Department of Orthopaedics, Iwate Medical University, Morioka, Japan INTRODUCTION ABSTRACT The knees of 72 patients with unilateral anteriorcruciate-ligament (ACL) injury were analyzed before ACL reconstruction as well as by follow-up arthroscopy on the day of staple removal. At ACL reconstruction 31 lateral menisci and 40 medial menisci were found to be normal. 28 lateral menisci and 24 medial menisci were treated surgically, while 13 lateral menisci and 8 medial menisci with small or incomplete meniscal tearing were not treated. At follow-up arthroscopy there were 3 new cases of lateral meniscal tearing and 3 new cases of medial meniscal tearing in the groups diagnosed as normal prior to surgery. Two of the 13 cases with small or incomplete lateral meniscal tearing required resection, 8 healed and the other 3 demonstrated no progressive change. Four of the 8 cases with small or incomplete medial meniscal tears healed, 3 exhibited no progressive change and one required surgical treatment. There was no correlation between meniscal tearing and knee instability as indicated by a positive Lachman test or a positive pivot shift sign. The results of the present study indicate that ACL reconstruction prevents progressive changes in meniscal tears and will prevent secondary osteoarthritis, and that some small tears of the lateral meniscus require no surgical treatment. Key words: ACL reconstruction, Meniscal injury, Arthroscopic study The goals of ACL reconstruction are both to recover knee function and to prevent secondary osteoarthritic change, the early changes of which involve meniscal rupture or degeneration. The present study investigated whether ACL reconstruction actually prevents secondary osteoarthritic change of the knee. Meniscal condition was assessed prior to ACL reconstruction and was re-evaluated by follow-up arthroscopy performed on the day staples were removed. Materials and Methods We evaluated the knees of 72 patients with unilateral ACL injury. Patients with severe injury to other knee ligaments, revised cases, and those with suturing of the meniscus were excluded from the present study. ACL reconstruction was performed using the semitendinosus and gracilis with staple fixation over the top position of the femur. We employed an accelerated rehabilitation protocol whereby the patients were permitted to bear as much weight as tolerable on their injured legs the first day after surgery 11 (Table 1). The average period from ACL reconstruction to follow-up arthroscopy was 16 months. We assessed the location and the degree of meniscal lesion as well as the degree of articular cartilage lesion at ACL reconstruction and follow-up arthroscopy. Pivot shift signs and Lachman tests were also assessed at follow-up arthroscopy. Correlation was Address correspondence and reprint requests to: Dr S Ichinohe, Department of Orthopaedics, Iwate Medical University, 19 1 Uchimaru, Morioka, , Japan

2 54 S Ichinohe et al. Journal of Orthopaedic Surgery Table 1 Rehabilitation Program Day 1 Supporting as much weight as possible, Hamstrings exercise, Isometric quadriceps exercise Day 2 Full extension exercise Day 3 Full weight bearing, Isotonic exercise 3 Weeks Jogging, Cycling, Swimming 2 Months Golf 3 Months Tennis, Table tennis (with brace) 4 Months Handball, Volleyball, Basketball (with brace) 6 Months Brace off tested using the analysis of 2 x 2 contingency table. Both Pearson s statistics and Fisher s statistics were performed with a statistical significance level of 5% (p<0.05). Results At ACL reconstruction, 41 lateral and 32 medial meniscal injuries were observed in a total of 72 patients. Twenty-eight of the 41 injured lateral menisci and 24 of the 32 injured medial menisci were treated by partial meniscectomy, while 13 of the 41 lateral menisci and 8 of the 32 medial menisci did not receive any surgical treatment. The types of lacerations observed in the lateral menisci were complete or incomplete stable vertical longitudinal tears posterior to the popliteal tendon and stable vertical tears beginning in the posterior third of the lateral meniscus and extending anterior to the popliteal tendon. The types of lacerations observed in the medial menisci were small stable longitudinal tears in the posterior segment without degenerative changes and small transverse tears in the middle segment without degenerative changes. Three new lateral and 3 new medial meniscal tears were detected by follow-up arthroscopy in the 31 lateral and 40 medial menisci, respectively, which had not been present at ACL reconstruction. Partial meniscectomy was performed on 2 of the above lateral menisci and 2 of the medial menisci at follow-up arthroscopy. Eight of the 13 lateral menisci that were treated conservatively had healed by the follow-up arthroscopy, but 2 menisci required partial meniscectomy due to progressive changes in the tear. At ACL reconstruction, these two lateral meniscal tears were seen as stable vertical tears beginning in the posterior third of the lateral meniscus and extending anterior to the popliteal tendon. Four of the 8 medial menisci that were treated conservatively had healed by the follow-up arthroscopy, but one meniscus with progressive changes was found to require subsequent meniscectomy. In only one case partial medial meniscectomy was repeated at follow-up to remove the remaining medial meniscus (Table 2). Table 2 Meniscal Condition and Treatment Findings at ACL Reconstruction Results of follow-up Arthoroscopy Treatment# New Tear or Progressive Change Healed OA Change* Lateral Meniscus Normal 31 3/31 1/31* Observed 13 2/13 8/13 0/13 Resected 28 0/28 7/28* Medial Meniscus Normal 40 3/40 2/40* Observed 8 1/8 4/8 0/8 Resected 24 1/24 3/24* #Normal: No meniscal tearing at ACL reconstruction Observed: No treatment for small meniscal tear Resected: Meniscectomy was done at ACL reconstruction * 2 cases had both medial and lateral degenerative changes

3 Vol. 8 No. 1, June 2000 Meniscal tearing after ACL reconstruction 55 Eleven knees showed degenerative changes of the articular cartilage such as fibrillation or ulceration of the cartilage. Most of these cases showed osteoarthritic changes of the tibial joint surface following meniscectomy (Fig.1a, 1b). A positive pivot shift sign or positive Lachman test was detected in 8 knees. These 8 cases were classified as unstable and the other 64 were classified as stable. In the unstable group, one new case of medial meniscal tear and 3 menisci that were observed at ACL reconstruction (2 lateral menisci and one medial meniscus) did not show progressive changes. Of the 8 cases in the unstable group, 25% showed osteoarthritic changes. The stable group included 3 new lateral and 2 new medial meniscal tears and 18 cases of the meniscus that were observed at ACL reconstruction. Two of the observed lateral menisci and one of the observed medial meniscus showed progressive changes and required meniscectomy at follow-up arthroscopy. Of the 64 cases in the stable group, 14% showed osteoarthritic changes. However, there were no significant differences (p<0.05) between the 2 groups (Table 3) and no correlation was found between knee stability and meniscal tearing. ILLUSTRATIVE CASES Case 1 In March 1994, a sixteen-year-old high school student was referred to our hospital with a complaint of right knee pain. He had a history of judo injuries and in Table 3 Meniscal Status and Knee Instability Stable Unstable Total Number 64 8 New Meniscal tear 5/64 1/8 Observed Meniscus 18/64 3/8 Progressive Change of 3/64 0/8 Observed Meniscus Degenerative Joint Change 9/64 (14%) 2/8 (25%) June 1993 was diagnosed with right knee MCL injury. He was re-injured during judo in February The right knee showed positive pivot shift sign and a negative McMurray test and we diagnosed him with right knee ACL injury. Arthroscopy was performed in March 1994, and the final diagnosis was right knee ACL injury with tears in both lateral and medial menisci. The medial meniscus was partially resected while the lateral meniscus treated conservatively (Figure 2). The ACL was reconstructed using the semitendinosus and gracilis. After ACL reconstruction, the patient had no subjective complaints or objective problems with the treated joint. Follow-up arthroscopy and staple removal were performed in March Lateral meniscal injury had progressed from an incomplete tear to an unstable complete tear, and thus lateral meniscectomy was subsequently performed (Fig.3a, 3b). Figure 1 Postoperative degenerative articular cartilage change was seen in the area of medial meniscectomy. Cartilage ulcer was seen in the area of lateral meniscectomy.

4 56 S Ichinohe et al. Journal of Orthopaedic Surgery Figure 2 Case 1. Stable incomplete longitudinal tear of the lateral meniscus was observed at ACL reconstruction. Figure 3 Case 1. Lateral meniscus injury had progressed from an incomplete tear to unstable complete tear by the time of follow-up arthroscopy. An additional lateral meniscectomy was performed. Case 2 A 23 year-old male injured while playing soccer was referred to our hospital with a complaint of right knee pain and swelling. There was severe knee swelling, restricted motion, a negative McMurray test, and a positive Lachman test. He was diagnosed with right knee ACL injury. Arthroscopy was performed in November 1995, and the final diagnosis was right knee ACL injury with tears in both the lateral and medial menisci. ACL reconstruction with lateral meniscectomy was performed on the day of arthroscopy. A small transverse tear of the medial meniscus was treated conservatively (Fig.4a, 4b). After ACL reconstruction, he had no complaints or problems with the treated joint. Follow-up arthroscopy showed osteoarthritic changes in the articular surface of both the lateral and medial tibia condyle and progression of the transverse medial meniscal tear to the anterior segment. We performed medial meniscectomy at follow-up arthroscopy (Fig.5a, 5b).

5 Vol. 8 No. 1, June 2000 Meniscal tearing after ACL reconstruction 57 Figure 4 Case 2. An unstable longitudinal tear of the lateral meniscus was resected. A small transverse tear of medial meniscus was observed at ACL reconstruction. Figure 5 Case 2. Follow-up arthroscopy. Postoperative degenerative change was seen after lateral meniscectomy. Transverse medial meniscus tear progressed from the middle segment to the anterior segment. Degenerative change in the articular surface of the tibia was also seen. DISCUSSION Few reports have investigated meniscal tearing after ACL reconstruction. However, several reports have found similar patterns of meniscal injury in the anterior cruciate deficient knee. 2,3 In those reports, in acute cases of ACL injury the rates of meniscal injury were 28.5 to 44% for the medial meniscus and 56 to 61% for the lateral meniscus. In chronic cases the rate of the medial meniscal injury was 70% to 74.5% and that of the lateral meniscus was 30% to 41.6%. Cases involved various intervals from injury to surgery, with an average interval from injury to followup arthroscopy of over 2 years. If the patients in the

6 58 S Ichinohe et al. Journal of Orthopaedic Surgery present study had not had surgery, they would be classified as chronic cases and the rates of medial meniscal injury would likely be over 70%. In the present study the overall rate of medial meniscal tear was 49% (35/72) and the rate of increase in medial meniscal injury after ACL reconstruction was only 4% (3 new cases). This is a relatively low rate of medial meniscal injury compared to the rates reported elsewhere. The low rate of increase in medial meniscal injury suggests that ACL reconstruction prevents progressive changes in meniscal injury. Several reports about ACL deficient knee concluded that degenerative changes in the articular cartilage are related to meniscal injuries and changes following meniscectomy 7,12 From these findings, it is possible to conclude that prevention of meniscal injury will prevent secondary osteoarthritis. Thus we believe that ACL reconstruction will prevent secondary osteoarthritis. Previous reports on meniscal tearing have concluded that there is no correlation between meniscal rupture or failure of sutured meniscus and trauma or knee instability after ACL reconstruction 6,9,10 The present study as well found 3 new lateral and 3 new medial meniscal tears that did not correlate with knee instability after ACL reconstruction. However, the number of cases with new meniscal tearing after ACL reconstruction is currently too small to discuss. Observation of a greater number of cases is needed before any conclusion can be made about the relationship between knee instability and meniscal injury. Fitzgibbons and Shelbourne reported conservative treatment of lateral meniscal injury combined with ACL reconstruction in 207 cases involving lateral meniscal injury with stable incomplete posterior horn tear or tear without displacement extending to the popliteal tendon 5. This study found no new meniscal tearing on average 2.6 years after follow-up. However, follow-up arthroscopy was not performed, so thus it could not be determined whether the menisci had healed. It is possible that some of these cases had unsymptomatic torn lateral menisci such as the two cases presented in this paper. Healing of meniscus depends on the location of the tear, the type of tear, the blood supply, and the degree of meniscus degeneration. Arnoczkey and Warren reported that the anterior and posterior horns of human lateral meniscus are more vascularized than the middle segment of the meniscus 1.In contrast, a different report could not find any differences in vascularity between normal and abnormal meniscus 4. Other reports concluded that the posterior horn and posterior part of the lateral meniscus have strong repairing ability 8.At follow-up arthroscopy, we observed good repair of stable vertical lateral meniscal tears that were totally posterior to the popliteal tendon. The cases that needed lateral meniscectomy at followup arthroscopy had relatively long tears extending anterior to the popliteal tendon. We conclude that small lateral meniscus tears located totally posterior to the popliteal tendon do not need surgical treatment. CONCLUSION 1. ACL reconstruction prevents progressive changes of meniscal tears and will prevent secondary osteoarthritis. 2. Further observation is required to determine the correlation between meniscal tear and knee instability after ACL reconstruction. 3. Small lateral meniscal tears totally posterior to the popliteal tendon do not need surgical treatment. REFERENCES 1. Arnoczky SP, Warren RF. Microvasculature of the human meniscus: Am J Sports Med 1982; 10: Bellabarda C, Bush-Joseph CA, Bach Jr. BR. Patterns of meniscal injury in the anterior cruciate-deficient knee: a review of the literature: Am J Orthop : Cipolla M, Scala A, Gianni E, Puddu G. Different patterns of meniscal tears in acute anterior cruciate ligament (ACL) ruptures and in chronic ACL-deficient knees: Knee Surg, Sports Traumatol, Arthroscopy 1995; 3: Danzig L, Resnick D, Gonsalves M, Akeson WH. Blood supply to the normal and abnormal menisci of the human knee: Clin Orthop 1983; 172: Fitzgibbons RE, Shelbourne KD. Aggressive nontreatment of lateral meniscal tears seen during anterior cruciate ligament reconstruction: Am J Sports Med 1995; 23: Mariani PP, Santori N, Adriani E, Masutantuono M. Accelerated rehabilitation after arthroscopic meniscal repair: a clinical and magnetic resonance imaging evaluation: Arthroscopy 1996; 12: McDaniel WJ Jr., Dameron TB Jr. The untreated anterior cruciate ligament rupture: Clin Orthop 1983; 172: Nishida M, Kimura M, Hasegawa J, Terauchi M, Minami T, Udagawa E, Shirakura K, Kaneko T. Study on the arthroscopic findings after ligament reconstruction in case with meniscal injury complicated by anterior cruciate ligament injury: J Tokyo Knee Society 1991; 12:

7 Vol. 8 No. 1, June 2000 Meniscal tearing after ACL reconstruction Sekiya I, Niga S, Hoshino A, Ikeda H, Nagatsuka Y. An analysis of additional operations for the medial menisci after ACL reconstructions: The Japanese J Arthroscopy 1994; 19: Sekiya I, Niga S, Hoshino A, Ikeda H, Nagatsuka Y. An analysis of additional operations for the medial menisci after ACL reconstructions: J Tokyo Knee Society 1995; 16: Shelbourne DK, Nitz P. Accelerated rehabilitation after anterior cruciate ligament reconstruction. Am J Sports Med 1990; 18: Sherman MF, Warren RF, Marshall JL, Savatsky GJ. A clinical and radiographical analysis of 127 anterior cruciate insufficient knees. Clin Orthop 1988;227: