Elbow Stiffness
Normal Elbow and Forearm Anatomy
The elbow and forearm form a functional unit whose primary role is to accurately position the hand in space. The elbow has a long lever arm and moves the forearm and hand 130 degrees covering much of the functional space used in our activities of daily living and in this sense the elbow is considered the most important single joint of the upper limb, second only to the thumb carpometacarpal joint. The functional space is defined as the space directly in front of a person’s body that lies below eye level and above the belly button. Because the elbow joint covers the entire functional space by virtue of its arc of motion, there has never been a satisfactory position to fuse an elbow joint if it were ever destroyed by injury or disease.
The elbow anatomy is best understood by thinking of it in three layers. The first layer is the bony layer, the second layer is the ligament layer and the third layer is the muscular layer within which the arteries and nerves travel.
Elbow & Forearm Elbow Joint Front View & Side View
The first layer is comprised of three bones that unite to form the elbow joint. The elbow joint is located at the lower end of the arm bone (humerus), and the proximal end (towards the shoulder) of the radius and ulna which are the two forearm bones. These three bones allow the elbow to bend (Flex) and straighten (Extend) in a hinged type motion and the forearm to rotate the hand in a palm up (supination) and palm down position (pronation). The joint surfaces of the elbow are covered by hyaline cartilage which forms a cushioned layer that allows for smooth gliding and painless elbow motion.
Elbow & Forearm Ligament LayerElbow Joint Ligament Layer
Lateral Elbow Ligament View Medial Elbow Ligament View
The second layer in the elbow and forearm is the capsular ligament layer made up of collagen tissue. The ligament layer in the forearm is called the interosseous membrane. The collagen tissue forming the elbow joint capsule is normally very thin except on the inside (medial) and outside (Lateral) sides of the elbow where thickenings in the collagen substance form the ligaments of the elbow. These ligaments provide passive stability to the elbow joint keeping the humerus, radius and ulna together, allowing them to function as a unit.
Foerarm Flexor CompartmentForearm Flexor & Mobile Wad Compartments
Elbow Flexor Muscles Elbow Extensor Muscles
The third layer of the elbow and forearm is the muscle layer and is formed by the various muscle groups that pass through the elbow and forearm either originating (beginning) or ending in the elbow and forearm. The muscles of the arm that pass through the elbow include the triceps muscle in the back of the arm and the brachialis and biceps muscles in the front of the arm. The forearm muscles that cross the elbow joint are divided into three compartments with each compartment containing several muscles that work to move the elbow, forearm, wrist and hand in specific directions. The three compartments are: 1. the extensor compartment 2. the flexor compartment and 3. the mobile wad of Henry compartment. The median, ulnar, and radial nerves pass through the elbow and forearm within the muscle layers and innervate the muscles within these compartments as well as, the muscles of the hand.
Pathology
The cause of a stiff elbow is either at the bony level or the collagen capsule/ligament level or both. The two most common cause of a stiff elbow is following a major trauma secondary to a fracture, fracture-dislocation or from repetitive microtrauma as occurs in pitchers that later develop arthritic spurs about the elbow from excessive forces generated during a normal pitch. When elbow trauma is associated with a close head injury, a buildup of abnormal bone can develop in locations where it is not normally found and this is called heterotopic ossification. If the bone develops in muscle, it is called myositis ossificans. When bone forms in the elbow, it can bind the humerus to the radius or ulna affecting flexion, extension and forearm rotation. If heterotopic bone forms between the radius and ulnaor radius and humerus,forearm rotation will be affected in the former and forearm rotation and elbow flexion and extension both affected in the later. To make the diagnosis, the physical exam and a plain x-rays are all that is required prior to proceeding with surgery.
Treatment
The Treatment of a stiff elbow depends on the cause of the stiff joint which can be a soft tissue contracture involving the elbow capsule and ligaments or heterotypic bone formation that binds the elbow joint rigidly preventing motion in flexion, extension or forearm rotation depending which of the three elbow bones are involved. When the problem is the joint capsule and only minor spurs are present in the elbow, the contracture can be removed arthroscopically through small incisions. If there is heterotopic bone, the procedure involves an open incision and within 24 hours of surgery, it is common to use a small dose of radiation to limit the recurrence rate of the heterotopic bone. Aggressive therapy to maintain the motion obtained during surgery is critical to ensure a lasting result. The use of splints to assist in the maintenance of the motion is also common. The time to maximum improvement varies depending on the cause. Arthroscopic soft tissue procedures are at maximum improvement within 2 months but open procedures involving bone removal may take as much as 4-6 months to reach maximum medical improvement.