Nonarticular Disorders (bursitis, tendinitis, enthesitis)Dz

Synonyms: Soft tissue rheumatism, overuse syndrome, bursitis; tendinitis, enthesitis.

ICD-9 Codes: Bursitis, 727.3; tendinitis, 726.9; enthesitis, 726.9.
ICD-10 Codes: bursitis M70; tendinitis M75/M76; enthesitis M77 (all with subheadings/specificities)

Definition: The term nonarticular disorders refers to pain and dysfunction attributed to structures that surround and support joints. By their proximity, pain related to nonarticular structures are not uncommonly mistaken for arthritis. Pain originating in nonarticular structures is perhaps the most frequent musculoskeletal complaint seen in general practice. Nonarticular structures include the numerous bursae, tendons, and ligaments present throughout the body. In many cases, injury secondary to repetitive overuse or trauma may cause inflammation and pain. However, some of these structures can become inflamed secondary to a systemic condition such as SpA or gout.

—Bursae: Numerous bursae (>150) are present throughout the body. They are typically located between muscles or between muscle and bone and contain scant amounts of synovium-like fluid. Their function is to allow smooth gliding between adjacent surfaces and to provide some buffer against injury. Inflammation of a bursa, or bursitis, usually results from trauma (particularly, repetitive trauma), overuse, or other types of direct injury. Bursitis may also be associated with systemic diseases (e.g., gout, pseudogout, RA). An inflamed or injured bursa often enlarges with fluid and can become a source of pain. Bursae can also become infected, usually with organisms (e.g., S. aureus) introduced from overlying skin.
—Tendons: Tendons can be a source of pain typically related to such biomechanical causes as overuse or repetitive injury. As is true for bursae, when tendinitis is the origin of pain, tenderness can usually be elicited by palpation and specific range-of-motion testing on physical examination. A number of tendons travel through a fibrous tube or sheath. Inflammation of the lining of this sheath is known as tenosynovitis. Tenosynovitis may result from direct trauma, repetitive-use injury, systemic inflammatory diseases, or infection. Stenosis and/or inflammation of a tendon sheath may interfere with smooth movement of the tendon. A “trigger finger” occurs when the flexor tendons of the hand cannot pass smoothly through the fibrous tunnels of the fingers and become caught. Other conditions of pain and entrapment related to tenosynovial involvement include de Quervain’s tenosynovitis, carpal and tarsal tunnel syndrome. When tendon injury or inflammation becomes chronic, rupture of the tendon may result. The insertion of the tendon into bone – the enthesis – is also a common site of pain.
—Ligaments: Ligaments attach one bone to another and thereby provide structural integrity to the skeleton. Injury to ligaments usually results from excessive force being applied. Excess force applied may cause an avulsion fracture although more commonly the ligament will tear; this is commonly called a sprain. Sprains range in severity from mild partial tears (grade I) to more severe tears where a sound (a “pop”) might be heard, to complete disruption of the ligament with resultant laxity.
—Entheses: The place where ligaments and tendons and synovial capsules insert into bone (the enthesis) may also be the site of inflammation. Enthesitis may result from trauma but may also be associated with systemic inflammatory diseases such as the seronegative spondyloarthropathies.

Etiology: Most forms of nonarticular pain are caused by direct trauma, repetitive-use injury, systemic inflammatory or crystal-induced diseases, or infection.

Demographics: Tendinitis, bursitis, and overuse syndromes are very common, affecting young, middle-aged, and older adults. Traumatic conditions are more common in young adults. Males are slightly more often affected than females. The prevalence of bursitis is estimated to be 2%.

Cardinal Findings: Often, a focused history and physical examination can readily pinpoint the specific cause of the patient’s complaint. However, it may sometimes be difficult to differentiate these soft tissue syndromes from arthritis or other processes. Often tendinitis, bursitis, or enthesitis can be identified as producing “point tenderness” and may exhibit pain on active, but not passive, motion. Examples of nonarticular pain are presented below.

—Subacromial (subdeltoid) bursitis: The subacromial bursa, the largest bursa in the body, lies between the deltoid muscle and the rotator cuff musculature of the shoulder. It may become inflamed in association with rotator cuff dysfunction or independently. Diagnosis of subacromial bursitis is usually made by demonstration of tenderness on direct palpation (the bursa lies immediately below the acromion).
—Bicipital tendinitis: Bicipital tendinitis often presents with pain localized to the anterior aspect of the shoulder. Pain often derives from the proximal end of the long head of the biceps, which runs through a tendon sheath in the bicipital groove of the humerus at the shoulder (see Arthrocentesis & Injections: Shoulder). Direct palpation of an inflamed tendon often generates pain. Pain may also be elicited by forced supination and flexion of the forearm against resistance. Rupture of the tendon of the long head of the biceps results in appearance of a bulge in the upper arm.
—Olecranon bursitis: The olecranon bursa lies directly over the olecranon process at the elbow. Olecranon bursitis is a common condition, particularly among older persons. Although it may be associated with conditions such as RA, gout, pseudogout, and infection with S. aureus (septic bursitis), most cases are idiopathic or result from minor repetitive trauma to the area. Tenderness on palpation and swelling owing to effusion are the key findings on physical examination. A useful clue to help differentiate olecranon bursitis from elbow synovitis is that pain related to olecranon bursitis increases as the forearm is fully flexed against the upper arm (which stretches the bursa) and diminishes with the elbow in full extension. By contrast, with true elbow synovitis, patients often hold the elbow in the neutral position (i.e., ~30 degrees of flexion); full flexion or full extension both increase pressure within the synovium and cause pain.
—Tennis elbow: Inflammation of the common tendon of the extensor muscles of the forearm as it inserts on the lateral epicondyle of the humerus is known as “tennis elbow.” Lateral epicondylitis often results from over-use (e.g., repetitive pronating of the wrist, in extension, against force. Physical examination often revels tenderness over the lateral epicondyle.
—Medial epicondylitis: Sometimes referred to as golfer ’s elbow, medial epicondylitis is less common than lateral epicondylitis. Pain over the insertion of the common flexor tendon at the medial epicondyle is the key to diagnosis. Medial epicondylitis often results from over-use (e.g., repetitive supination of the wrist against force)

In addition to these conditions, other causes of elbow pain include synovitis of the elbow joint and ulnar nerve entrapment (with tenderness on palpation of the ulnar nerve groove and signs of ulnar neuropathy).

—Wrist tenosynovitis: Common in patients with RA, wrist tenosynovitis may be difficult to distinguish from synovitis of the underlying radiocarpal joint. Unilateral tenosynovitis may be seen in patients with disseminated gonococcal infection or gout.
—de Quervain tenosynovitis: Inflammation of the abductor pollicis longus or extensor pollicis brevis on the radial aspect of the wrist is referred to as de Quervain tenosynovitis.
—Trochanteric bursitis: There are several bursae in the area of the greater trochanter of the femur. These bursae are positioned between the trochanter (the bony prominence felt on the lateral aspect of the upper thigh), the gluteus medius and minimus muscles, and the fascia lata. Trochanteric bursitis is a common cause of pain in the region of the hip (see Hip Pain). It occurs mostly among older persons and is more common in women. It may be associated with other conditions that can affect gait, such as OA of the hip, knee, or lumbar spine; leg length discrepancy; and obesity. The typical presentation is chronic, intermittent pain over the lateral aspect of the hip. The pain may radiate inferiorly or superiorly and may be confused with hip pain of other causes. The diagnosis is usually established by demonstration of excessive tenderness on palpation over the trochanter. In addition to NSAIDs and local corticosteroid injections, therapy directed at correcting associated conditions may provide relief.
—Ischial bursitis: Inflammation of the ischial bursa presents as pain over the ischial tuberosity (the bony prominences beneath the gluteal muscles) that is exacerbated by prolonged sitting on hard surfaces (see p. 208). Ischial bursitis was previously referred to as “weaver ’s bottom.” Iliopsoas bursitis presents with groin pain just anterior to the hip joint and lateral to the femoral vessels.
—Meralgia paresthetica: Compression neuropathy of the lateral femoral cutaneous nerve commonly presents with burning pain in the anterolateral aspect of the hip and thigh. It is commonly seen in patients who are pregnant, diabetic, or obese.
—Anserine bursitis: The anserine bursa is located just inferior and medial to the knee (see Knee Arthrocentesis, Figure 1). Anserine bursitis is common, particularly among overweight women. Pain can be elicited by palpation directly over the bursa and is often exacerbated by stair climbing. Other bursae are located below the medial and lateral collateral ligaments and may be a source of pain.
—Prepatellar bursitis: Often manifesting as swelling and tenderness superficial to the patella, prepatellar bursitis (known previously as “housemaid’s knee”) is associated with trauma to the front of the knee, as with kneeling. Tendinitis of the patellar tendon may also produce anterior knee pain. It is typically aggravated by athletic activities and has been referred to as “jumper ’s knee.” In children, particularly 10- to 16-year-old boys, pain over the insertion of the patellar tendon into the tibia may indicate Osgood-Schlatter disease (avulsion of the tibial tubercle).
—Chondromalacia patellae: Characterized by knee pain, crepitus, and degenerative cartilage changes on the underside of the patella, chondromalacia patellae occurs primarily in young adults, particularly women. The pain of chondromalacia patella is exacerbated by knee flexion against force, for example with stair climbing. Such movements pull the patella close against the femoral condyles. In addition, patients may complain of pain and stiffness with prolonged inactivity that is relieved with motion. Pain attributable to chondromalacia patella can often be elicited by pushing the patella against the femur, particularly at the lateral aspect. This condition is also known as patellofemoral pain syndrome and patellofemoral tracking abnormality. Relative weakness of the medial thigh muscles that allows lateral drift of the patella and abnormal tracking movements may contribute to the pathophysiology. Furthermore, in addition to NSAIDs and avoidance of overuse, exercises aimed at strengthening the medial thigh muscles (e.g., bicycling) may be a useful therapeutic intervention. In more severe or refractory cases, surgical intervention (e.g., release of the lateral retinaculum, realignment of the vastus medialis oblique muscle) may be indicated in some patients.
—Adams-Baker’s cyst: Patients with synovitis of the knee may develop Adams-Baker cysts (also known as Baker’s cysts or popliteal cysts). In this condition, fluid accumulates within the posterior compartment of the knee. Although effusion and swelling may be asymptomatic initially, continued accumulation often causes pain. In addition, the fluid may dissect inferiorly, between the muscles of the calf. This may result in a clinical presentation resembling deep venous thrombosis, and ultrasonography may be necessary to differentiate the two. Various conditions (RA, OA, mechanical derangement of knee) are associated with popliteal cysts. Synovial fluid accumulation in the cyst is caused by a ball-valve mechanism, whereby synovial fluid is forced from the anterior to the posterior aspect of the knee and cannot freely flow back. This may be the result of proliferative synovium (e.g., in RA or other forms of inflammatory arthritis), a torn meniscus, or a fold of synovium (known as a plica). Therapy is directed at the appropriate underlying condition. Inflammatory conditions can sometimes be treated, and the cyst resolved, by local injection of corticosteroids into the joint rather than the cyst.
—Achilles tendinitis: The Achilles tendon may become painful from a variety of causes, including direct trauma (e.g., with improper footwear), repetitive overuse (e.g., with athletic activity), and systemic inflammatory diseases (e.g., AS, PsA, other SpA). Pain on palpation is often appreciated at the bony insertion of the tendon. With chronicity, the tendon can become “bumpy” with irregular swellings and have crepitus with motion. There are also bursae superficial to and deep to the Achilles tendon that can become inflamed and be a source of pain. Although not typically associated with pain, xanthomas or rheumatoid nodules along the Achilles tendon can be seen in patients with hypercholesterolemia or RA, respectively.
—Plantar fasciitis: Plantar fascia can be a source of substantial pain. Plantar fasciitis may be associated with trauma, and some patients have an associated spur on x-ray. This condition is also associated with SpA.
—Costochondritis: Pain may arise from the costochondral junctions. The term Tietze’s syndrome is commonly used to describe cases of costochondritis in which there is not only substantial tenderness on examination but also swelling. The first and second costochondral junctions are most commonly affected.

Diagnostic Tests: Laboratory tests are seldom useful because these are clinical diagnoses.

Imaging: In general, radiographs are of limited value in patients with tendinitis and bursitis. As these soft tissue injuries become chronic, they may be associated with local deposition of calcium, resulting in conditions such as calcific tendinitis and periarthritis. Ultrasound and MRI can image tendons and tendon sheaths well, and can assess the presence of inflammation. MRI can also assess most ligaments and tendons clearly; ultrasound can be used in certain situations depending on anatomic location.

Keys to Diagnosis: Nonarticular pain should be suspected when there is a history of trauma or repetitive movement associated with the onset of symptoms. “Joint” pain without abnormalities localized to the joint on examination should lead the clinician to search for nonarticular (periarticular) sources of joint pain.

Differential Diagnosis: The site of involvement determines the differential diagnosis. In general, a careful history and physical examination are necessary to distinguish true arthritis from tendinitis, bursitis, and enthesitis. Whenever inflammatory findings exist, infectious, crystal-induced, and inflammatory conditions should be considered.

Therapy: Therapy for local soft tissue injuries typically involves several modalities. NSAIDs are commonly used, either at their lower analgesic doses or at higher anti-inflammatory doses. Topical therapies (e.g., local heat and/or cold) may offer some benefit. Physiotherapy is an important part of the treatment of these conditions. Because many relate to overuse, rest and protection of the affected area are often beneficial acutely. Subsequently, physiotherapy is aimed at preventing recurrence of the condition by optimizing range of motion, improving flexibility, and maximizing the strength of the surrounding musculature. In some cases, local injection of corticosteroids can effectively ameliorate the inflammation and thus decrease pain.

BIBLIOGRAPHY

Biundo JJ, Mipro RC, Fahey P. Sports-related and other soft-tissue injuries, tendinitis, bursitis and occupation related syndromes. Curr Opin Rheumatol 1997;9:151–154. PMID: 9135920