ACL Injuries and Meniscal Lesion: Hand in Hand?

Objective: To assess the incidence, nature and pattern of meniscal tear in ACL injury. Methodology: A retrospective study was conducted among the patients who were admitted and treated for ACL tear in Saveetha Medical And College And Hospital over a 2-year period from August 2019-August 2021. There were 52 patients admitted and treated for the same. The case records of each of the patients were reviewed to find the incidence of meniscal lesion in ACL tear and were then analyzed using appropriate statistical tests. Results: 52 patients with ACL tear were reviewed in this study. ACL tear was most commonly reported in younger age group of 20-29 (46.15%). Out of which, 19(36.54%) patients had meniscal tears. About 9(47.37%) patients had lateral meniscus tear, 6(31.58%) had medial meniscus tear and 4(21.05%) had bilateral meniscal tear. It was seen that bucket handle injury (n=12) was the most common meniscus tear overall. Radial tear was most specifically common in bilateral meniscus injury (N=4). Conclusion: Meniscal tears are the most common intra articular lesions associated with ACL tear. It was most commonly reported in the age group of 20-29. We found that the incidence of lateral meniscal tear was significantly higher in the patients rather than medial meniscal tear. Bucket handle injury was the most commonly reported tear in meniscal injury. Therefore, the surgeon needs to equip himself with the necessary meniscal repair instruments in his armamentarium


INTRODUCTION
The main role of meniscus is to evenly distribute impact forces through the knee and to maintain joint stability. A meniscus tear is usually caused by twisting or turning quickly. These tears can occur commonly while playing sports or lifting heavy weights and is common in young, active adults [1,2]. Degenerative tears commonly occur in patients with osteoarthritis. Initially meniscus tear was described as functionless remain of a leg [3] extensive scientific studies have described meniscus as one of the most important structure of the knee [4].
Meniscus tear can occur along-side with other ligamentous injury and it is commonly associated with ACL tear because of its anatomic and functional relationships to these structures. Isolated ACL tears are not common [5].
For maintaining long term joint function, especially in active patients, meniscal tissue function should be preserved. However concomitant meniscal surgery has no significant effect on patient outcome on strength and jump metrics post-operatively [5]. Early repair of posterior horn of lateral meniscus has significant improvement in loading profile in lateral compartment and may help in prevention of damage of cartilage and osteoarthritis associated with partial menisectomy [5,6].
The purpose of this study is to document the frequency, morphology and commonest meniscal injuries accompanying anterior cruciate ligament tear

METHODOLOGY
A retrospective study was conducted among the patients over a period of August 2019-August 2021.The data was collected from the database of the Orthopaedics department of Saveetha Medical College And Hospital. The site and type of meniscus repair was recorded.

Inclusion criteria
During the study period, 52 patients met the inclusion/ exclusion criteria which included 45 male patients and 7 female patients.

Meniscal Tear Classification
In all patients, diagnostic arthroscopy was done to confirm the meniscal lesions. Tears were documented as lateral and medial meniscal tear which was further subdivided into anterior horn, posterior horn and body involvement. Types of meniscal tears were further classified as longitudinal tear, radial tear, horizontal tear, bucket handle tear and flap tear, complex tear

RESULTS
Out of 52 patients reviewed in this study, it was found that about 19(36.54%)patients had meniscal injury along with ACL tear whereas 33(63.46%) patients had isolated ACL tear alone. The ACL tear was most commonly reported in the right knee in 38(73.07%) patients.
13(25%) patients had ACL tear in left knee and about 1(1.93%) had bilateral knee involvement. Table 2 shows the site of the meniscal tear. The most commonly reported injury was located in the lateral meniscus which was seen in 9(47.37%) patients. In 6 (31.58%) patients it was located in the medial meniscus and in 4(21.05%) patients both lateral and medial meniscus were involved. Table 3 shows the morphology of meniscal tears associated with ACL injury. The most commonly reported tear was the bucket handle tear. It was seen in about 12 patients commonly reported in bilateral meniscal tear(4) and about 1 patient in lateral meniscal tear and 1 patient in medial meniscal tear. Flap tear was reported only in one patient with lateral meniscal tear.
The patients with medial meniscal tear (6) underwent partial medial meniscectomy and bilateral meniscal tear patients (4) had underwent bilateral partial meniscectomy along with ACL reconstruction.

DISCUSSION
ACL is a band of connective tissue that courses from femur to tibia. It helps to keep the knee stable [7]. About 50% of ACL tears are most commonly associated with meniscal tears [8,9]. ACL tear is a common tear with an annual incidence ranging between 68.610000 person years in the population. ACL is an important stabilizer of the knee joint, most commonly occurs with twisting of knee whilst weight bearing. An ACL tear typically will present with rapid joint swelling and significant pain.  [16,17] as well as bilateral meniscal tears [17,18]. In our study, radial tears were seen in both medial and lateral meniscal tears.
Diagnostic arthroscopy was done to confirm the ACL tear and concomitant meniscal injuries. As Arthroscopy is the gold standard diagnostic method for diagnosis of meniscal tears than MRI [19,20].

CONCLUSION
Meniscal tears are often missed injuries in the pre operative phase. The association between ACL injuries and Meniscal tears needs to be establishes to enhance the surgeons preparedness to address the meniscal problem. In concomitant ACL and meniscal injuries, the symptoms of instability can supersede the symptom of pain thereby masking the meniscal lesion. Hence it is imperative for the treating physician to be well aware of the expected meniscal injuries so that treatment is effective.

CONSENT
As per international standard or university standard, patients' written consent has been collected and preserved by the author(s).

ETHICAL APPROVAL
As per international standard or university standard written ethical approval has been collected and preserved by the author(s).