Coach Bob Huggins initially indicated that Butler had sprained his left MCL (medial collateral ligament). However, West Virginia’s Sports Information Director later announced that an MRI performed on Sunday revealed an ACL (Anterior Cruciate Ligament) tear as well as two bone bruises in addition to the MCL sprain. It seemed apparent from the moment Butler planted his left foot and his knee gave way that this was more than a mild sprain.

What is the ACL?
The Anterior Cruciate Ligament is the primary stabilizer of the knee. It is located between (and attaches) the rear outer base of the femur (thigh bone) and the top of the front inner tibia (the larger of the two bones in the lower leg). It is called the anterior (front) cruciate because it crosses another ligament (the posterior cruciate) that is located behind it, with the two ligaments essentially forming an “X”. The role of the ACL is to prevent the top of the tibia from gliding forward. When torn, this motion is not checked and the knee becomes unstable, often buckling.

What is the MCL?
The Medial Collateral Ligament also connects the femur to the tibia but at the inner, or medial compartment of the knee joint. When Butler went down it appeared that his knee buckled inward, permitting excess motion at the inner joint (the foot and lower leg angled outward). This would be indicative of an MCL injury.

What is a bone bruise?
Muscles, nerves and bones can all suffer bruises, which are also known as contusions. Contusions occur because of trauma associated with impact, and the severity of that impact is one important determinant of the degree of injury and rate of recovery. Simple muscle contusions generally resolve in a matter of weeks, and the healing process involves muscle repair, regeneration and scar-tissue formation. All contusions result in localized inflammation as well as pain and they may also inhibit muscle strength. Nerve contusions can precipitate neuralgic symptoms, while bone bruises can be particularly debilitating as well and some studies indicate their relationship to arthritic changes over time.

The specific location and type of bone bruises suffered by Butler were not clarified in reports of the injury. Though they may have resulted because of the impact against Zoubek (in this case they would likely be more superficial) they may also have occurred at the bony surfaces of the knee joint in the course of tearing his ACL. When an ACL injury occurs, excess or abnormal motion (of one bone on the other) is permitted, allowing the bones to bump into each other, resulting in a contusion. The MRI was an important diagnostic tool used to identify the nature and extent of Butler’s injuries, and if he suffered this type of contusion, it likely demonstrated abnormalities in the bone deep to the smooth cartilage that lines the joint.

Da’Sean Butler will have surgery soon and has a long road of aggressive rehab ahead. Therapy will focus on controlling any inflammation and swelling, restoring range of motion, muscle strength and flexibility, balance, and ultimately on movement, agility and plyometrics (jumping, etc). At the same time he will work to maintain his cardiovascular endurance. According to NBADraft.net, Butler is ranked as the 21^st-best prospect in the 2010 NBA Draft, while DraftExpress.com has him as 44^th in line. In a mock draft that was updated after the injury, DraftExpress had Butler as the 14^th pick in the second round. He was interviewed during the championship game yesterday and expressed confidence that he will play in the NBA next season. With a great attitude and work ethic, the advances in surgery and rehab today, and with youth on his side, it is very likely that Da’Sean Butler will achieve his dream.

Wait a minute, isn’t the UCL at the elbow?
Recent columns on this site have discussed UCL injuries to pitchers’ elbows resulting in the need for Tommy John surgery as well as the implications of ankle ligament tears.  First let’s quickly review the basics to help you understand the nature of Shaq’s injury.

A ligament is the connective tissue connecting one bone to another to provide stability at a joint.  Each joint has at least one ligament on each side.  In the hand or elbow, the inner (medial) side, or side of the ulna bone in the forearm, is called the ulnar side and the outer (lateral) side is called the radial side because of its relationship to the radius (the outer bone in the forearm). Hence, at the base of the thumb, just as at the elbow, the ligament stabilizing the innermost part of the joint is called the ulnar collateral (UCL).

Injury to a ligament diminishes stability at the joint it protects, and may do so even on a permanent basis, so Shaq’s prior injury may have predisposed him to re-injury. 

Other names for the UCL tear of the thumb
Most often called “Skiers’ Thumb” these days because of its prevalence on the slopes, this injury used to be known as “Gamekeepers Thumb” because it was commonly found amongst Scottish Gamekeepers (wildlife managers) as a result of a repetitive stress and stretch to the ligament that they suffered when doing their work. 

How does this injury occur?
A force that pulls the thumb away from the hand places stress on the UCL at the joint where the thumb meets the palm.  If the force at this joint (also called the MCP, or metacarpophalangeal joint) is traumatic and causes the joint to exceed its normal limit of movement, the UCL is sprained. And, as for any ligament, a Grade III Sprain is really a complete tear.

A skier who falls while holding the pole, or anyone who tries to break a fall by reaching out with his hand to absorb the impact may suffer a Skiers’ Thumb injury.  If the thumb is bent backwards and a ligament tears, it is unlikely to be able to heal in the anatomical position because of the resultant instability of the joint.  That is why Shaq is having surgery.  Occasionally, just as was previously discussed with regard to ligament injuries at the inner aspect of the ankle, the UCL ligament may not tear but instead might pull off a chip of bone at its point of attachment (at the base of the thumb).  This injury is called an avulsion fracture and it too can result in instability at the joint if not corrected surgically.

So, what did Shaq’s thumb probably feel like after the injury?
Just as after any partial or complete ligament tear, fluid builds up causing swelling.  Visible discoloration is an indication that a ligament (or other vascularized structure like muscle or tendon) was torn.  Naturally, pain is a factor and it will hurt to use the thumb (to grip or squeeze) or to bend it backward.  Reports are that Shaq will be out for six to nine weeks to heal and rehab following today’s surgery.  The Cavs or course, are hoping to have him back in the line-up to help them in the later rounds of the playoffs.