Miguel Cabrera Suffers A Season Ending Biceps tendon Rupture
Miguel Cabrera, all-star first baseman for the Detroit Tigers, sustained a biceps tendon rupture against the Twins on June 12th. The injury occurred while at bat, when he swung and missed an off-speed pitch. Injuries happen in sports, but this one is unusual in baseball and very unusual to occur while swinging the bat. From a medical standpoint, this injury and how it occurred, leaves several questions unanswered. Let's break this injury down a bit further.
Cabrera's Swing and A MISS
Miguel Cabrera is a right handed batter that sustained a biceps tendon rupture to his left arm. Physiologically the injury doesn't quite make sense. The biceps muscle is primarily responsible for flexion (bending) of the elbow and supination (turning the arm palm up); neither of which would be occurring in the left arm of a right-handed batter. Secondly, 80-90% of distal biceps tendon tears occur in the dominant arm, but Cabrera is right-handed. Lastly, distal biceps tendon injuries rarely occur in overhead athletes, yet are common in weightlifters. Most commonly, the injury occurs when an athlete has a sustained contraction of the biceps with the palms facing upwards, such as when doing a biceps curl or lifting a heavy object.
Evaluation OF Distal Biceps Tendon
Athletes will usually have notable swelling and bruising within the bend of the elbow. Additionally, there may be a palpable mass just above the elbow, which represents the retracted muscle and tendon after the rupture. This exam finding is typically referred to as a "Popeye deformity" as it resembles the bicep of the cartoon character Popeye. A hook test can be performed to check the integrity of the distal biceps tendon (pictured below). Weakness will also be reported with flexion and supination of the elbow. Tip: The biceps plays a large role in supination and less so flexion of the elbow, which is done by the brachialis muscle. Therefore testing flexion alone may not give the full extent of the injury
Hook Test
With elbow flexed to 90 degrees the finger is hooked around the distal biceps tendon to check its integrity.
Treatment and Return to Play
In general, a distal biceps tendon rupture is a dramatic and serious injury. Nonoperative treatment is not typically a reasonable option for athletes to return back to sports at their pre-injury levels. Research has shown that nonoperative treatment may lead to significant loss of strength with supination, flexion and grip. On the other hand, patients with partial tears can be treated with physical therapy to improve strength and regain full range of motion. Operative management is focused on reattaching the distal biceps tendon back to the bone, which can be done through several different methods. Post-surgical care may consist of splinting the arm at 90 degrees and supinated for about a week and progressing back to gentle range of motion. Progressive strengthening usually will occur 6-8 weeks after surgery and return at 4-6 months based on strength and ROM.
The Question Still Remains
The question that we are stuck with is the following: Why did a rare injury (biceps tendon rupture) happen in an unlikely sport (baseball) on the improbable arm (non-dominant) with an implausible mechanism (swinging a bat)? Obviously we won't know for sure, but it is suspicious and intriguing.