A i.e. Excessive - History of twisting strain (flexion, abduction/ valgus and medial rotation of femur on fixed tibia Q/ lateral rotation of tibia on fixed femur) followed by locking of knee pintQ is diagnostic of medial meniscus tear. - Mc Murray's test, Apley grinding test and Squat tests are done to diagnose meniscus (medial & lateral) injuryQ. - Excessive forward glide is d/t anterior cruciate ligament tear (not meniscus injury)Q. Meniscal tear is the commonest knee injury that require surgery. Medial meniscal tears are 3 times more common than lateral meniscus tears . Paial meniscetomy is done for tears not amenable to repair eg. cornpex, degenerative and central/ radical tearsQ. Meniscal repair should be done for all acute lateral/ peripheral tears especially in young patient undergoing concurrent ACL reconstructionQ. Meniscal Injury *Meniscus or semilunar cailage are relatively avascular structure with poor healing potentialQ. *Medial meniscus is larger and more oval than its fellow Medial meniscus is more frequently torn than the lateral because it is securely attached and less mobileQ where as lateral meniscus is more mobile and protected by action of popliteus muscle At bih entire meniscus is vascular; by age a months, the inner one third has become avascular. This decrease in vascularity continues by age 9 years, when the meniscus closely resembles the adult meniscus. In adults , only 10- 25% of lateral meniscus and 10- 30% of medial meniscus is vascular. Because of the avascular nature of inner two thirds of the meniscusQ; cell nutrition is believed to occur mainly through diffusion or mechanical pumping. So inner avascular meniscus once torn does not healQ. *The commonest type of medial meniscal injury in a young adult is the bucket handle tearQ (i.e. complete longitudinal tear). Other types are - flap tears, radial tears, complex tears etc *Ceain active spos- such as soccer, hockey, tennis, badminton, squash and skiing are commonly associated with meniscus injuries, paiculary when pivoting with all the weight on one leg with the knee flexed (i.e. twisting in flexed knee)Q. It used to be common in coal miners who had to stoop or squat in narrow seams with the knee joints flexed. *A common history is as follows: whilst involved in violent spoing activity or work with the knee in a position of flexion the patient suddenly sustains an outward twist of the foot or an inward twist of femur on the fixed foot. He immediately feels acute pain on anteromedial aspect of joint along with feeling of a tearing sensation and displacement of an internal structure. On attempting to rise, straightening of the knee is usually not possible (locking)Q *The meniscus may become completely displaced and locked between the femur and tibia, preventing full extension of the knee. More frequently the torn meniscus will cause pain, intermittent catching and occasionly locking as it flips into and out of the region of contact between the femur & the tibia. *In meniscal injury due to development of effusion (not hemahrosis) with in a few hours (not immediately) joint swells. It is impoant to note that swelling occuring immediately after injury, is d/t hemahrosis; which may be caused by an injury to cruciate or collateral ligaments or by an osteochondral fracture. The doughy feel of haemahrosis distinguishes ligment injuries from the fluctuant feel of the synol effusion of a meniscus injuryQ. *Symptoms include- joint line pain, catching, popping and lockingQ, usually and weakness & giving wayQ (instability) sometimes. Deep squatting and duck walking are usually painful. Joint line tendernessQ, pain with squatting, a positive flexion Mc Murry testQ. and positive Apley's compression-distraction testQ are all indicaive of meniscal injury. *Before the impoance of meniscus was understood and ahroscopy was available the meniscus was often removed entirely. But now attempts are made to remove only the torn poion of meniscus (if tear is in avascular poion), or repair the meniscus (in vascular peripheral poions if possible). Ahroscopy is the gold standard for making diagnosisQ and ahroscopic repair or removal is the treatment of choice. *Tears in the peripheral third of the meniscus, if small (< 15 mm), may heal spontaneously because this poion in adults has good blood supply. Larger tears require repair. Diagnostic Tests For Meniscal Injury - MC- Murray, Apley and Squat tests are useful tests to diagnose meniscal injury. All of them basically involve attempts to locate and reproduce crepitations, snaps or catches, either audible or detected by palpation that result as the knee is manipulated during flexion, extension and rotator motions of joint. Mn-" MAS Tests" -If these noises can be localized to the joint line (confirmed by palpation of posteromedial / posterolateral margin of joint), the meniscus most likely contains a tear. Whereas similar sounds from quadriceps mechanism, patella and patella femoral grove must be differentiated. Tears of one meniscus can produce pain in opposite compament of knee. This is most commonly seen with the posterior tears of lateral meniscus. Therefore these tests are valuable diagnostically but not diagnostic (confirmatory) and MRI or ahroscopy is needed for confirmation. Negative MAS tests do not rule of meniscal injury. Management of Meniscal Injury - Nonoperative management consists of groin to ankle cylinder cast or knee immobilizer worn for 4-6 weeks with crutch walking and toe touch down weight bearing. If symptoms recur after this, surgical repair or removal of damaged meniscus may be necessary and more specific diagnostic procedures (MRI, ahroscopy) are indicated. - Complete removal of meniscus is only justifiable when it is irreparably torn, and the meniscus rim should be preserved if at all possible. Total meniscetomy is better avoided in young athletes or people whose daily activity requires vigorous use of knee. Excision of only torn poion (paial, sub total meniscetomy) are better procedures. - Ideal indication for meniscal repair is an acute, 1 to 2 cm, longitudinal, peripheral tear that is repaired in conjunction with anterior cruciate ligament reconstruction in a young individual. Peripheral 1/3rd to 1/4th meniscus is vascular enough to provide vascular granulation tissue that results in healing of meniscal tears in this zone. Miller-Warner & Harrier categorized tears a/ t there location in 3 zones of vascularity : red - red, fully within peripheral vascular zone; red-white, at the border of vascular area; and white -white, within the central avascular area. They recommended repair of red-red and red white tears. Likelihood of healing or reparability, depends on several other factors in addition to vascularity specifically type of tear, chronicity and size (in same order), Longitudinal -acute and small tears heal better than radial/ flap type - chronic and large tears. In cruciate ligament injury the findings can be somewhate perverse i.e. with a complete tear the patients may have little or no pain, whereas with a paial tear the knee is painful. Swelling also is worse with paial tears, because haemorrhage remains confined with in the joint; with complete tears ruptured capsule permits leakage and diflusion. Paial tears permit no abnormal movement, but the attempt cause pain. Complete tears permit abnormal movement which sometimes is painless.