Torn Ligament Sidelines Angels Mike Trout for Much of Summer

Two-time AL MVP comes up with “skier’s thumb” sliding into 2nd base

One of baseball’s biggest stars will miss the beginning of the summer, as Mike Trout of the Los Angeles Angels underwent surgery on Wednesday, May 31, 2017, to repair a torn ligament, the ulnar collateral ligament (UCL) in his left thumb. Trout injured his thumb in Sunday’s game against the Miami Marlins while sliding into 2nd base. The injury is expected to sideline the American League All-Star vote leader for 6-8 weeks.

The ulnar collateral ligament stabilizes the medial side of the joint between the proximal phalanx of the thumb and the first metacarpal. The ligament helps to prevent hyperextension and excessive abduction of the thumb and plays an important role in stabilizing the thumb during gripping.

Most commonly, the ligament is sprained or torn by events that cause a rapid hyperextension of the joint. The injury has been nicknamed “skier’s thumb,” due to its prevalence in skiers who land on an outstretched hand with their thumb extended. In baseball, the injury occurs most commonly in the way Trout’s did: sliding into a base, and catching the thumb on the bag.

Mike Trout’s severe torn ligament may affect his hitting upon return

Much like other ligament injuries throughout the body, mild UCL sprains can be treated non-operatively, while a full rupture of the ligament will require surgical stabilization. Most commonly, the ligament tears from its distal attachment on the proximal phalanx, and in some cases can tear a chip of bone in an avulsion injury. In this case, surgery is usually required to return adequate stability.

Surgery usually involves using sutures to stitch the torn area of the ligament back to the bone. In the case of a fracture being involved, a small screw may be used to fixate the bone chip. Either way, the thumb is usually casted for a period of 4-6 weeks after surgery, allowing adequate time for the ligament to heal back to the bone.

Rehabilitation after this period of immobilization focuses on regaining dexterity of the thumb after being immobilized, and a gradual return to activity. Trout’s largest rehabilitation focus will be on hitting, as the thumb is very important in providing the grip strength needed to swing a bat. Given the injury is to his left thumb, and he is a right-handed thrower, he will not have significant issues returning to throwing.

But the injury involves his glove hand, meaning that he will need to demonstrate sufficient stability and grip strength in order to return to the field. For this, it is likely that he will continue to wear a removable thumb splint when he returns to play, in order to stabilize the joint further inside his glove.

Trout’s injury is one that could affect his play as he returns to the field late in the season. He may struggle to hit consistently as he regains grip strength, and it’s likely we will see him play some designated hitter as he returns in order to avoid potential re-injury in the field. However, there should be no long-term complications for him from this surgery, meaning that the two-time AL MVP should easily return to being one of the best two-way players in baseball.