The knee is one of the largest joints in the body, and one of the most easily injured. Anterior Cruciate Ligament (ACL) tears and meniscal tears are among the most common knee injuries.
The ACL is one of the four major ligaments of the knee that connect the thigh bone (femur) to the lower leg bone (tibia). It stabilizes the knee and minimizes stress across the knee joint. Nearly 400,000 ACL repair procedures are performed each year in the U.S.1 Though ACL tears are more common in males, young female athletes are up to eight times more likely to tear their ACLs.2
The meniscus is two wedge-shaped pieces of cartilage in the knee that act as “shock absorbers” between the thighbone (femur) and shinbone (tibia). Meniscal tears, also referred to as cartilage tears, and there are more than 300,000 meniscal repairs performed each year in the U.S.
The shoulder is made up of three main bones: the arm bone (humerus), the collarbone (clavicle) and the shoulder blade (scapula). The shoulder blade has a shallow socket (glenoid) surrounded by a ring of cartilage, called the labrum. The labrum deepens the glenoid socket so that the head of the upper arm bone fits better. This is commonly called a ball-and-socket joint. The rotator cuff is made up of four muscles that come together as tendons to stabilize the shoulder joint by keeping the head of the arm bone seated in the glenoid socket.
One of the most common injuries to affect the shoulder is rotator cuff tears.3 Most rotator cuff tears are degenerative. When one or more of these tendons tear, it is referred to as a rotator cuff tear since at least one tendon is no longer fully attached to the humeral head.
Glenoid labrum tears are commonly referred to by the location on the labrum that the tear occurs. A SLAP tear is an injury to the top (superior) of the labrum and can occur both in front (anterior) and back (posterior) of the attachment. SLAP stands for Superior Labrum Anterior and Posterior. A Bankart tear is a tear to the anterior inferior glenoid labrum that causes the shoulder to dislocate.4
1. Millennium Research, Data on File at Cayenne Medical
2. American Academy of Orthopedic Surgeons (AAOS) and National Athletic Trainers Association
3.Williams GR, Rockwood CA, Bigliani LU, Iannotti JP, Stanwood W (December 2004).”Rotator cuff tears: why do we repair them?”. The Journal of Bone and Joint Surgery American Volume 86-A (12): 2764–76. PMID 15590865.
4. Widjaja A, Tran A, Bailey M, Proper S (2006). “Correlation between Bankart and Hill-Sachs lesions in anterior shoulder dislocation”. ANZ J Surg 76 (6): 436–8. DOI:10.1111/j.1445-2197.2006.03760.x. PMID 16768763.