Michael W Bowman M.D. FACS
The elbow is an amazingly complex anatomical structure and allows us to position our hand in space. It is actually made of 3 joints that allow us to both flex the arm up and down and rotate the forearm. The anatomy of the elbow joint is both intricate and sometimes delicate, which makes fractures of the elbow difficult to assess and repair. As seen in figure 1, the elbow is formed by the end of the Humerus or arm bone. It is also made up of the proximal end of the Radius and Ulna bones of the forearm. There is flexion and extension between the Humerus and the combined Radius and Ulna. There is also rotation (pronation and supination) between the Radius and Ulna so that you may turn your hand. On the end of the humerus there are two thickened parts called the lateral epicondyle and medial epicondyle, where muscles attach. In between is a thin area called a fossa, which is vulnerable to injury.
The proximal end of the ulna is shaped like a claw with two beaks called the olecranon process and coronoid process. Muscles attach to both these processes. In between them is the round circular joint surface that articulates or moves with the humerus. With flexion up and down, the olecranon process and coronoid process move into the thin fossa. The end of the Radius (Radial head) is rounded like a disk, allowing it to flex up and down on the humerus and also rotate against the ulna so that the forearm may pronate and supinate.
Most commonly fractures of the elbow are caused by a fall, either directly on the elbow or on an outstretched hand. Fractures of the elbow can either be simple or comminuted with many pieces. They may be closed or open, with bone sticking out or exposed. The fracture may involve the elbow joint (intra-articular) or be outside the joint (extra-articular). Fractures usually describe the parts that are involved. For instance a supracondylar fracture is located above the thickened condyles of the humerus. An intracondylar fracture is split between the condyles through that weak fossa. Fractures of the proximal Ulna may involve the olecranon process, the joint surface or the coronoid process. Fractures of the Radius may involve the Radial Head, or the thinner Radial Neck just past that. Because of the complex bony anatomy of the elbow, the 3 joints involved and the multiple muscle attachments, surgical treatment of elbow fractures is very difficult.
Physical examination of the elbow after a fracture is usually difficult due to the enormous swelling that is usually present. Multiple x-rays and a CT scan are often necessary to adequately assess the location and nature of the fracture. Each fracture is very unique, although there are some common patterns of fracture. A treatment plan for the elbow fracture must incorporate the location and nature of the fracture as well as the patient's age, general health, bone density and healing issues such as smoking or malnutrition.
In general broad terms, nondisplaced, stable, extra-articular elbow fractures may be treated conservatively with a long-arm splint or cast extending above the elbow to the wrist. Several x-ray examinations in the splint/cast may be necessary to check for displacement of the fracture that may occur even in the cast/ splint. For elbow fractures that are displaced, unstable or have disrupted one of the joints, open reduction and internal fixation (ORIF) may be necessary. In this surgery one or more incisions are made at the elbow to open and expose the fracture sites. After reducing or aligning the fracture pieces, surgical fixation may be accomplished with smooth pins, screws or small specialized plates. The surgical ideal is to achieve rigid fixation of the fracture so that early elbow range of motion may be started at therapy. This helps to avoid the very common stiffness that develops after an elbow fracture. The surgery is usually performed as an outpatient, under general anesthesia. Afterwards a protective long-arm splint is applied. If the bone quality and surgical fixation are adequate, a protective but removable plastic long-arm splint will be used. Occupational therapy and early gentle range of motion exercises for the elbow will be initiated shortly after surgery. Once the fracture is healed, more aggressive exercises and strengthening will begin. In cases where the bone quality is poor or rigid fixation cannot be accomplished, the splint will be maintained until sufficient healing is accomplished to allow motion. Risks with elbow fractures and treatment are anesthesia related problems, infection or wound healing problems, stiffness of the elbow, irritation or injury to the Ulnar Nerve. The Ulnar Nerve may be affected by the original fracture process, scar tissue or a bony spur that develops after the fracture heals and may be irritated from retracting it during surgery. It should be noted that stiffness is a frequent and significant complication from having an elbow fracture. Usually there is loss of extension or straightening. This holds true for both fractures treated operatively and nonoperatively.