Elbow Overview
Elbow Anatomy
The elbow is a hinge joint, similar to the knee. However, the anatomy of the elbow allows for rotational movement in the forearm. The elbow connects the humerus (upper arm bone) to the radius and ulna (forearm bones). Like the other joints in the body, the elbow is supported by strong ligaments, tendons and cartilage that all aid in the strength and movement of the elbow. Elbow injuries can be extremely painful and, if severe, can cause the loss of range of motion, strength and use of the elbow. Orthopedic Surgeon and Sports Medicine specialist, Dr. Jonathan Koscso, successfully diagnoses and treats patients in Sarasota, FL and the surrounding Gulf Coast region who have experienced an elbow injury.
Bony Anatomy of the Elbow
Three major bones meet to form the elbow joint, each playing a critical role in the function of the elbow:
Humerus: The upper arm bone which connects at the elbow with the radius and ulna. The distal humerus has a complex anatomy with important muscle and ligament attachments that are critical to normal elbow function.
Ulna: One of the two forearm bones (along with the radius) that articulates with the trochlea (a part of the distal humerus at the elbow joint). The ulna is located on the medial (inner) side of the elbow.
Radius: One of the two forearm nones (along with the ulna) that articulates with the capitellum (a part of the distal humerus at the elbow joint). The radius is located on the lateral (outer) side of the elbow.
Soft Tissue Anatomy of the Elbow
The elbow cannot offer mobility and strength without other supporting structures that help it move and keep it functioning properly. Elbow stability is achieved with the help of muscles, tendons, ligaments and cartilage. These important structures include:
Cartilage: Often called articular cartilage, this slippery tissue covers both the ends of the bones and allows them to glide together easily. In the elbow joint, cartilage covers the distal humerus as well as the proximal radius and ulna. The breakdown of this cartilage can cause elbow arthritis. Sometimes, young athletes (commonly baseball players and gymnasts) can develop focal disruptions in this cartilage near the lateral (outer) part of the elbow, a condition know as osteochondritis dissecans of the capitellum.
Ligaments: There is a complex network of ligaments around the elbow that function to stabilize the joint during daily activity and sporting endeavors. On the medial side, the medial ulnar collateral ligament (mUCL) stabilizes the medial (inner) part of the elbow. This ligament is most notably injured in baseball players and can necessitate the popularized “Tommy John surgery.” On the lateral (outer) side of the elbow, the lateral ulnar collateral ligament stabilizes the lateral aspect of the elbow joint and can be damaged in traumatic injuries.
Muscles / Tendons: Several important muscles have attachments near the elbow. The biceps attaches to the radius via its tendon and contributes to elbow flexion (think of a bicep curl). Injury here can lead to a distal biceps tear and necessitate surgery to reattach the tendon. The muscles that allow for wrist extension and flexion also attach to the lateral (outer) and medial (inner) sides of the elbow, respectively. Chronic inflammation in these tendon attachments can lead to lateral epicondylitis (“tennis elbow”) or medial epicondylitis (“golfer’s elbow”).
Nerves: several important nerves that allow for normal hand and forearm function cross the elbow joint and may be compressed by other tissues. Most notably, the ulnar nerve passes along the medial (inner) part of the elbow, and compression here can lead to cubital tunnel syndrome- a condition often leading to sensory changes and ultimately muscle weakness in the hand.
About the Author
Dr. Jonathan Koscso is an orthopedic surgeon and sports medicine specialist at Kennedy-White Orthopaedic Center in Sarasota, FL. Dr. Koscso treats a vast spectrum of sports conditions, including shoulder, elbow, knee, and ankle disorders. Dr. Koscso was educated at the University of South Florida and the USF Morsani College of Medicine, followed by orthopedic surgery residency at Washington University in St. Louis/Barnes-Jewish Hospital and sports medicine & shoulder surgery fellowship at the Hospital for Special Surgery in New York City, the consistent #1 orthopaedic hospital as ranked by U.S. News & World Report. He has been a team physician for the New York Mets, Iona College Athletics, and NYC’s PSAL.
Disclaimer: All materials presented on this website are the opinions of Dr. Jonathan Koscso and any guest writers, and should not be construed as medical advice. Each patient’s specific condition is different, and a comprehensive medical assessment requires a full medical history, physical exam, and review of diagnostic imaging. If you would like to seek the opinion of Dr. Jonathan Koscso for your specific case, we recommend contacting our office to make an appointment.