What is Tommy John Surgery?

by Bob Tallitsch | November 4, 2019

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I recently returned from guest lecturing in a colleague’s anatomy class at a small liberal-arts college similar to Augustana College, my home institution. My colleague asked me to come and observe his class and then, during the subsequent class session, teach forearm anatomy so that he could see how I typically engage students and get them interested in more than just the “facts” of anatomy.

I learned that most of the students in the lecture session were interested in health professions so, as we walked into lecture the next day, I asked my colleague the following question; “What could be a better real-world connection for these students than to get them to think and talk about injuries that are common in the sports world?” The baseball postseason was still in progress, and one baseball injury and surgical repair procedure often mentioned in conjunction with some major league baseball pitchers is “Tommy John Surgery”.

I asked the students in the lecture the following question: “What is this injury, what anatomical structure or structures does it involve, and how is it surgically repaired?” The quiet classroom was quickly filled with questions that transitioned into a short discussion about what the students thought the anatomical injury and repair procedure was. Following this discussion I told them that, in order to understand this injury and its reparative orthopedic surgery, we first needed to understand the anatomy and function of the elbow joint and the joints of the forearm.

Anatomy and Function of the Elbow and Forearm Joints 

The elbow joint is actually composed of two joints: the joint between the humerus and the radius, and the joint between the humerus and the ulna. In the lateral humeroradial joint, the capitulum of the humerus articulates with the head of the radius. The larger, and more medial humeroulnar joint is where the trochlea of the humerus articulates with the trochlear notch of the ulnar. The elbow joint is quite stable, due to three factors:

  1. The interlocking of the bony surfaces of the humerus and ulnar, which prevents lateral movement at the elbow;
  2. the thick capsule of the elbow joint; and,
  3. the ulnar (medial) collateral ligament, radial (lateral) collateral ligament, and annular ligament, all of which reinforce the joint capsule.

The forearm has two joints: the proximal and distal radio-ulnar joints. At the proximal radio-ulnar joint the head of the radius forms a joint with the radial notch of the ulna. The annular ligament and the quadrate ligament hold the head of the radius in place. The distal radio-ulnar joint is comprised of the ulnar notch of the radius, the radial notch of the ulna, and the articular disc. The antebrachial interosseous membrane and a series of radio-ulnar ligaments hold the distal radio-ulnar joint together.

These joints enable a wide range of movements in the forearm. The joint between the ulna and the humerus allows flexion and extension of the forearm at the elbow, while the joint between the radius and the humerus, combined with the proximal and distal radio-ulnar joints, allows for medial and lateral rotation of the radius around the ulna (also termed pronation and supination).

Even though the elbow and radio-ulnar joints are quite strong, repetitive, high-velocity stress, such as that encountered by major league pitchers, can damage the elbow joint. That type of damage typically involves the ulnar collateral ligament, also termed the medial collateral ligament. This triangular ligament extends from the medial epicondyle of the humerus to the coronoid process and olecranon of the ulna. This ligament is composed of three thick bands of connective tissue. The anterior band is the thickest, is triangular in shape, and connects the medial epicondyle of the humerus to medial margin of the coronoid of the ulna. The posterior band is also triangular in shape and connects the medial condyle of the humerus to the olecranon of the ulna. The third, inferior band (or inferior oblique band) is the weakest and connects the olecranon and the coronoid process, deepening the trochlear notch. The function of the ulnar collateral ligament is to stabilize the elbow against valgus forces, which are forces pushing the forearm and hand toward the lateral side of the elbow.

Throwing at high velocity places a high level of valgus force on the elbow joint, which may lead to cartilage injuries, inflammation, bone spurs, or even a tear in the ulnar collateral ligament. If an individual tears the ulnar collateral ligament he or she will still have full range of movement at the elbow, but they will not be able to throw at a high velocity. Hence the need for orthopedic surgical repair for a major league baseball player with this type of injury.

Surgical repair of the ulnar collateral ligament is often termed “Tommy John surgery” because Tommy John — a pitcher for the Los Angeles Dodgers — was the first recipient for this type of orthopedic surgery in 1974. This form of orthopedic surgery typically involves reattaching the torn part of the ulnar collateral tendon and then taking a tendon graft from another part of the body (either the tendon of the palmaris longus muscle of the forearm or a segment of a hamstring) and threading it through holes that were drilled in the ulna and humerus. The tendon graft is then sutured in place in order to stabilize the elbow joint. Following appropriate physical therapy the repaired elbow joint may function perfectly, thereby allowing the athlete to resume throwing at a high-velocity.

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Following the lecture session my colleague and I talked for quite a while and as I drove home, I was convinced that he understood the importance of engaging students and getting them interested in more than just the “facts” of anatomy. If you're interested in learning more about some of the different ways you can engage your anatomy students, download  my eBook - Breathing Life Back into Your Anatomy Classroom and check out some of my other blogs below.

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