Injuries of the elbow may be divided into three categories; single event macrotrauma, single event trauma superimposed upon the tissue vulnerability of multiple overuse, and multiple repetition overuse. To the sideline observer, single event macrotrauma is the most visible cause of injury. Since the skeletal anatomy of the elbow is quite stable, single event injury to normal tissue generally requires the substantial violence of collision. For this reason, direct trauma to the elbow is necessary to cause fracture or dislocation of the joint. An exception may be ulnar collateral ligament (UCL) rupture which may occur in the act of throwing without collision. This type of injury is, however, more commonly noted in a ligament previously weakened by repetitive overuse. Thus, perceived single event tendon rupture may also represent a combined etiology. Repetitive overuse represents the most common form of injury about the elbow seen in the outpatient office setting, with examples being tennis elbow tendinosis and chondromalacia of the olecranon compartment. This paper will focus on the authors observations concerning the injury problems most likely to confront the physicians, physical therapists, and athletic trainers treating an athletic population.
ANATOMY AND BIOMECHANICS
The elbow is made of three bones with three articulations The trochlea of the humerus, which articulates with the olecranon process of the ulna, defines the plane of flexion and extension. The depth and congruence of the medial side of the elbow limits the function of the elbow to that of a true hinge joint, stable to all motions except in the medial - lateral plane, encountered during varus and valgus stresses. The radiocapitellar joint provides some stability to valgus stresses by acting as a pivot for axial load. However, without a strong ulnar collateral ligament on the medial side of the joint, the forearm would dislocate laterally during valgus stress. The anterior oblique portion of the UCL is the primary stabilizing ligament of the elbow joint, an advantageous development for daily life activities, since the elbow is more commonly subjected to valgus than varus stresses such as for picking up large objects. In contrast, the lateral ligamentous constraints of the elbow are not as well developed. The tendons of the wrist extensor mechanism, originating on the lateral intermuscular septum of the arm and the lateral epicondyle, are required to help stabilize the elbow against varus stress. Commonly this musculotendinous complex must act against eccentric load, a biomechanically harmful situation. Pronation and supination are forearm motions facilitated by the elbow. The radial head and neck are contained by a capsuloligamentous complex which includes the annular ligament. Although rarely exposed to acute traumatic pronation and supination, the elbow commonly sees repetitive overuse in these planes of motion, resulting in injury to soft tissues, such as tendinosis or nerve entrapment syndromes.
MECHANISM OF INJURY
Single event injuries are most often the result of collision of an outstretched hand with the ground. If the elbow is somewhat flexed, posterolateral dislocation may occur. If the elbow is fully extended, transmission of force up the radius may result in a fracture of the radial head or capitellum. Varus / valgus shear forces at the time of impact may result in fracture of condylar and supracondylar structures (more common in children). Direct impact of the elbow, another mechanism of injury, may result in fractures about the elbow, most likely the olecranon. Entrapment of the elbow between players (as in football tackling) can also result in fracture or more likely, dislocation. In multiple repetition overuse, the most common etiologies include eccentric overuse of the forearm extensors (e.g., tennis backhand results in lateral tennis elbow), and valgus stress in throwing (e.g., ulnar collateral ligament attrition and rupture, common flexor tendon overuse, and or olecranon compartment chondromalacia and loose bodies secondary to the friction forces of valgus instability).
PATIENT HISTORY Components of the patient history which help differentiate which of the three categories of injury has occurred are found in the patient's description of the quality, intensity, and onset of pain they feel. The exact location(s) of symptoms and their effect on function are important details. Neurovascular elements in the history, and episodes of swelling indicate extra- and intraarticular pathology.
Intense pain of a sudden onset after a known stress (such as a collision) suggests an acute process. If the injured region has had any associated symptoms in the past, one must consider an underlying chronic component. If pain has been recurrent, in a similar intensity and location, then chronic repetitive overuse is suspected.
Acute traumatic injuries may cause disruption of many tissues, so the pain may be regionally diffuse. An isolated fracture of the radial head may be more localized, mimicking lateral epicondyle pain, but the mode of onset for this injury is more acute, and due to axial load on an extended elbow or valgus stress. Conversely, the location of pain from repetitive overuse injuries tends to reflect specifically the anatomic course of the damaged tissues. Acute - on - chronic injuries may have both localized and generalized pain.
In the acute setting functional loss may be caused by gross structural disruption or solely by pain. To differentiate mechanical blockade from protective splinting, a careful physical examination is required (see below). In the repetitive overuse setting, loss of function is usually less dramatic, but long-standing limitation of motion may result in fibrous ankylosis of the elbow joint or even osteophyte build-up in the joint, so a patient may present with loss of motion from repetitive overuse.
Neurologic and vascular symptoms such as parasthesias, coolness, numbness, or clumsiness are of vital importance because the brachial artery and the ulnar, median, and radial nerves traverse the elbow. Peripheral nerve dysfunction may reflect neuropathy, radiculopathy, or local nerve compression. If an acute trauma is associated with neurologic complaints, nerve entrapment or neurapraxia are considered. In repetitive overuse injuries, pronator syndrome (median nerve) or cubital tunnel syndrome (ulnar nerve) present with painful neurologic complaints, but Posterior Interosseous Nerve (PIN) syndrome generally does not, because the PIN is primarily a motor nerve, with resultant weakness rather than pain . Vascular injury, which is usually limited to acute trauma situations such as fracture or dislocation, should be aggressively investigated.
When a patient reports episodes of swelling and complaints of clicking or grinding sensations, intraarticular pathology of synovium, cartilage, and bone are suspected. Acute onset of these symptoms after a traumatic event in a previously normal elbow suggests that a hemarthrosis due to fracture or dislocation has occurred. Reports of recurrence and remission of these symptoms, with unknown origin of onset indicate repetitive overuse pathology. Lateral tendinosis may cause localized swelling over the origin of the wrist extensor tendons. Whenever painful swelling occurs near a joint, inflammatory conditions and septic arthritis are part of the differential diagnosis.
Visual inspection for anatomic distortion is the first step in assessment. Alteration of skeletal alignment in the presence of pain and tenderness is indicative of acute fracture or dislocation. Distortion without acute signs may indicate prior skeletal injury with malunion or malformation. The soft tissues may be distorted due to localized hematoma, edema, effusion, or muscle/tendon rupture.
The next assessment steps include palpation for tenderness, crepitus, and swelling, followed by evaluation of motion. Restriction of motion because of pain is much different than restriction because of tendon scar, adhesive capsulitis, or bony blockade (e.g., loose bodies, bony exostosis, fracture, or dislocation). Painful immobility tends to have a softer endpoint and associated guarding, whereas purely mechanical limitation has a firmer endpoint, less guarding, and possibly some associated crepitus. It is important to assess not only flexion and extension but also pronation and supination.
In the overuse injury group, lateral and medial tennis elbow tendinosis are most common. Location of palpable tenderness over the origin of the origin of the extensor carpi radialis brevis (approximately one centimeter medial and distal to the lateral epicondyle) and the tip of the medial epicondyle extending distally one to two centimeters along the track of the flexor carpi radialis and pronator teres are indicative of lateral and medial tennis elbow, respectively. Manual provocative resistance stress testing confirms the diagnosis. To check for lateral tennis elbow tendinosis (lateral epicondylitis), use resisted wrist extension and resisted grasping with the elbow extended. For medial tennis elbow tendinosis, use resisted wrist flexion and pronation as provocative tests. The ulnar nerve is commonly associated with medial tennis elbow. Tenderness and a positive Tinel's sign over the Nirschl zone 3 of the medial epicondylar groove are indicative of ulnar nerve problems. (Nirschl zone 1: proximal to medial epicondyle, Zone 2: at level of epicondyle, Zone 3: distal to medial epicondyle).
Finally, in collision and throwing sport etiologies a check for stability is indicated. Valgus instability is checked by applying a valgus stress with the elbow flexed 20 degrees (to release the olecranon). Laxity which exceeds the non-injured elbow indicates ulnar collateral ligament rupture. Look for chondromalacia in the olecranon fossa in this circumstance. Tenderness distal and just under the medial epicondyle confirms ulnar collateral ligament injury. For posterolateral instability, provocative forced elbow extension, axial loading, and forearm supination will cause the posterolateral subluxation associated with a rupture of the collateral ligament (elbow pivot shift test).
In the collision group, the major diagnostic issues are to rule out fracture and or dislocation. The most common athletically induced fractures about the elbow include the radial head, olecranon, and capitellum, but any fractures can of course occur. In adolescents avulsion of the medial epicondylar apophysis (little league elbow) can occur either by throwing or collision. A common companion to little league elbow may be osteochondritis dessicans of the capitellum. Dislocation is most commonly posterolateral, and may be accompanied by a fracture of the coronoid process, where the brachialis muscle inserts. This type of dislocation always has major disruption of the ulnar collateral ligament and often has associated rupture of the lateral collateral ligament. With collision injuries always keep in mind the possibility of neurovascular injury, especially the brachial artery.
In the overuse group, lateral and medial tennis elbow tendinosis are by far the most common. A common companion to medial tennis elbow is neurapraxia of the ulnar nerve via compression in the Nirschl zone 3 area of the medial epicondylar groove. Although often cited as the cause for lateral tennis elbow, radial nerve dysfunction has been rarely noted by the authors. A positive Tinel's sign over the radial nerve, suggesting nerve compression, would occur more distal and radial (under the brachioradialis) than the site of lateral epicondylar pain. It should be noted that lateral and medial tennis elbow are often associated with other upper extremity tendinosis. Related problems including shoulder tendinosis, upper back and scapular weakness, and carpal tunnel syndrome should be anticipated and sought out. Assess these associated problems by carefully examining for tenderness and weakness in the rotator cuff, scapular stabilizers, and wrist, respectively. This combination of problems is often bilateral, and has been termed "Mesenchymal Syndrome." The message of the "Mesenchymal Syndrome" is that the differential must be cognizant of pathoanatomical issues beyond the focus of the elbow. In patients older than the fourth decade, cervical osteoarthritis may be present but not directly etiologically related to the elbow.
On field treatment of overuse injuries is not a pressing issue. Comfort and anti-inflammatory measures (e.g., ice application) are the key along with advice as to continue or withdraw from competition. As a general rule in overuse treatment, withdrawal from participation is indicated when the presence of pain associated with the sport technique causes an alteration of the technique (e.g., the character or intensity of the sport technique is altered to control pain).
Collision injuries require careful review of neurovascular compromise. Application of anti-inflammatory measures (e.g., ice if no vascular alteration, and protective splinting) are indicated. With dislocation, gentle elbow flexion with forearm rotation to neutral may result in spontaneous reduction. If neurovascular injury occurs directly as a result of a fracture or dislocation, prior to a reduction attempt, and no medical facility is nearby, an immediate reduction maneuver is considered, depending partly on the experience of the treating physician. But if a medical facility is nearby and no nerve or vessel is damaged , it is best to splint in situ, transport, and obtain radiographs first, then to perform reduction in a controlled environment, such as the emergency room or operating room. Collision injuries in general warrant prompt objective imaging (e.g., x-ray, etc.) and treatment whereas overuse injuries may benefit from the luxury of a more leisurely definitive diagnostic and treatment protocol.
WHAT TEST TO ORDER
Collision injuries with resultant fracture or dislocation require accuracy not only for diagnosis but treatment planning. Regular x-rays (e.g., A.P., lateral, and olecranon views) may suffice but on occasion oblique views, tomograms, or stress views are needed. A CAT scan may be needed to enhance bony detail and MRI is useful for soft tissue detail although in the acute setting, MRI is rarely necessary. Vascular compromise is of course an emergency and requires immediate vascular consultation and testing as indicated.
Chronic overuse injuries should have routine x-rays (helpful to rule out other maladies as chronic pain may be reflective of systemic disease). Loose bodies may require arthrogram or tomogram. Suspected ulnar collateral ligament damage may require an MRI for diagnostic confirmation. In exotic and non-responsive pain situations, a bone scan may define a stress fracture or some elusive systemic disease. Diagnostic issues concerning peripheral nerve dysfunction may be aided by EMG and nerve conduction studies.
Collision injuries with acute skeletal distortion require reduction followed by protective stabilization including the potential for surgical stabilization. Immediate treatment should include a careful neurovascular assessment and coverage of wounds. It is best to have radiographs before attempting reductions, whenever possible. Splinting to include the wrist, elbow, and upper arm may be needed. Avoid wrapping bandages tightly, as a tourniquet effect can occur. Even after reduction, elbow dislocation may require operative intervention to repair ligamentous disruption particularly if a bone fragment (such as the medial epicondyle attached to the UCL) becomes entrapped. The distinction between dislocation and subluxation becomes unclear when a dislocation spontaneously reduces, but the more important issue is whether lasting instability requiring surgery remains. In general, dislocations do not, however, require surgical intervention as closed reduction generally places the ligaments in a continuity adequate for quality healing. Conversely, the magnitude of soft tissue damage associated with dislocation and the usually abundant reparative process often results in scar adhesions and contractures. Early mobilization (usually within a few days after a stable reduction) is often the best treatment. A removable pouch sling will suffice in most cases. With varus / valgus instability after trauma, a hinge brace allowing flexion and extension may be used. A posterior splint is reserved for only the most unstable circumstances or in the immediate postoperative period. The authors use an elbow immobilizer with Velcro closures which has struts like a knee immobilizer. (fig.4a, see enclosed photograph) If adhesive capsulitis does eventually occur it may be usually resolved by operative release utilizing the less morbid and more predictable approach as recently described by Cox and Nirschl.
The overuse group of injuries as noted are somewhat diverse including tendinosis, ulnar nerve neurapraxia, UCL ligament attrition and rupture, loose bodies and chondromalacia of the olecranon fossa, capitellum, and posterolateral compartment. The most common problem is lateral and medial tennis elbow tendinosis. For the tendinosis group, the curative goals include neovascularization of the injured tissue, with collagen production and maturation in association with an overall restoration of strength, endurance, and flexibility via rehabilitative exercise. It should be noted that the strength deficiencies associated with tennis elbow extend far beyond the elbow and also include the arm, shoulder, scapular, thoracic, and cervical muscles. The traditional comfort roles of rest and anti-inflammatory medicines (including cortisone injections) have no curative potential and are utilized only as an adjunct to allow efficient and comfortable rehabilitative exercise. Additionally, the use of counterforce braces, designed specifically for medial or lateral epicondylitis appears to provide comfort by dispersing forces seen by underlying damaged tissues. Braces are not a substitute for rehabilitative exercises.
The remaining overuse problems of 'ulnar nerve neurapraxia', 'ulnar collateral ligament attrition', chondromalacia, and loose bodies may be aided by rehabilitative exercise but often require surgical intervention. Failed rehabilitation in the tendinosis group may also require surgical intervention. It should be noted that failed comfort treatment (rest and anti-inflammatory medication) without appropriate curative treatment (e.g., rehabilitative exercises) is not an indication for surgery.
WHEN TO REFER
The issue of referral is subject to many variables. The basic principles, however, are dual; namely, the expertise of the physician and the complexity of the problem. In general the care of elbow problems is quite complex and a variety of patho-anatomical presentations is often the norm. Accurate and precise patho-anatomical diagnosis are of course critical. Any confusion concerning the diagnosis is a fundamental reason to refer.
Since the overuse group of injuries are not of an emergency room nature, delivery of some care might be considered by the non-orthopedic team physician. Conversely, since the definitive care of this group of injuries is largely based in quality rehabilitation, it is axiomatic that the treating physician have a true and thorough understanding of rehabilitation and the means to implement it. Note that dependence upon physical therapy treatments dedicated to comfort alone is not an adequate rehabilitative effort. Deficiency in the ability to provide quality rehabilitation is therefore an indication for referral. Stabilization, protection, and pain control in the collision group of injuries are best followed by referral.
WHEN TO OPERATE
Some basic concepts of operative intervention have been touched upon in the sections on definitive treatment and referral. In general, fracture and or dislocation requires reduction either by closed or open means. If the reduction is in appropriate position and stable, external protection will suffice. Unstable or unacceptable alignment situations require surgical intervention.
Tendinosis problems which fail to respond to rehabilitation may be candidates for surgery, particularly if the activities of daily living are disrupted but also if sports potential is compromised. Similar considerations may be appropriate for UCL rupture, ulnar nerve neurapraxia, intraarticular chondromalacia, and loose body formation, adhesive capsulitis, and osteochondritis dissecans or continuing posterolateral instability.
APPROPRIATE TIME COURSE FOR RESOLUTION
The diversity of problems addressed in this paper makes the anticipated time of resolution difficult to discuss. Dislocations because of soft tissue damage often take months. Similar situations may occur with fractures although a non-displaced fracture of the radial head treated with appropriately aggressive rehabilitation should perform well at six to eight weeks except in elbow loading sports such as gymnastics.
The conservative treatment of tennis elbow tendinosis usually shows results within weeks, but full return to sport often takes three to four months. Similar time frames are noted with UCL attrition. Full rupture of the UCL, however, as determined by clinical exam and MRI may prove unresponsive to return to the throwing sports even after six to nine months. Appropriate care may thus require surgical intervention.
Chondromalacia and synovitis of the posterior olecranon fossa and lateral compartments may show some response within weeks. Loose bodies and intra-articular osteophytes will in general be unresponsive to non-surgical treatment.
PRINCIPLES OF REHABILITATION The basic principles of musculoskeletal rehabilitation including the elbow as practiced in our clinic are as follows:
I. Relieve pain and inflammation:
The pneumonic PRICEMM standing for protection, rest, ice, compression, elevation, medications, and modalities works well. The most effective modalities are heat, cold (ice), and high voltage electrical stimulation. Analgesics, anti-inflammatory medicines, and cortisone injections are used selectively and sparingly for comfort to aid in allowing an appropriate progression for the rehabilitative and fitness exercise programs.
Start fitness programs to all uninjured areas immediately.
The biological goals are to encourage neovascularization, collagen production and collagen maturation, as well as restoring overall strength, endurance, and flexibility.
- proper technique
- proper intensity and duration
- proper equipment
- protective counter-force bracing These concepts are utilized during the rehabilitative and fitness programs as well as with return to performance exercise (e.g., sport, performing arts, and occupational).
The criteria for return to play concerning the elbow are similar to other musculoskeletal regions. The ideal criteria include a restoration of normal strength, as well as endurance and flexibility associated with performance capacity specific for the selected sport. It should be noted that two basic principles must be included in the return criteria; namely, the risk of reinjury and the ability to perform at a satisfactory level. In general the medical focus is on injury potential whereas the sports community tends to focus performance. It is clear, however, that both factors are often intertwined. An important variable concerning the medical issues is not only the potential for re-injury but the potential for expanded or permanent damage.
In general elbow problems are not life threatening or major deterrents to the activities of daily living. A certain latitude, therefore, may be entertained regarding return criteria. Thus, it is not uncommon for a gradual return to sport with less than normal physical capacity. Examples of this happenstance include up to ten degrees loss of extension or painless ulnar nerve motor dysfunction in throwers. With specific reference to the tendinosis group, a gradual return to racquet and throwing sports proceeds when 90% of grip strength is achieved (in comparison to the non-dominant uninjured arm). For full competitive play the dominant arm grip strength should exceed the non-dominant by a minimum of 10%. It again should be noted that normal strength return should also include the arm (biceps, triceps) as well as the entire shoulder girdle, upper back, and neck.
Final important principles must also be discussed regarding the return criteria. These include transitional performance exercise, protective sport technique, and bracing. It must be appreciated that the power, speed, and angles at which sport is played far exceeds the criteria for success of completion of rehabilitation exercise. (e.g., the resistance systems of isometrics, isotonics, isoflex, and isokinetics). Transitional exercises including both eccentric and concentric load, plyometrics, and specific performance sport drills are, therefore, critical to the successful return process. Careful analysis of the sport activity or technique which caused the initial injury must also be undertaken. Once the injurious activity is identified, avoidance is to be implemented. Avoidance techniques may include alteration of sports technique, training habits, equipment, and the utilization of elbow counter-force bracing.
A review of the common injury problems to which the elbow is subjected has been discussed. The etiological issue of single event macro-trauma versus multiple repetition micro-trauma are reviewed. In the treatment protocols, the clear distinctions between comfort versus curative treatment are made.
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