Tendinopathy: Tendinosis, Paratenonitis
There is pain along an involved tendon, often poorly localized, that worsens with motion, resisted contraction, or passive stretching. A vibratory crepitus may be felt on palpation during tendon movement. Common sites include the posterior heel, the inferior aspect of the patella, the greater tuberosity of the shoulder, the thumb side of the wrist (de Quervain disease, see Chapter 107) and the lateral elbow (tennis elbow, see Chapter 116). There may be a history of repetitive overuse of the tendon or of a single sudden pull. Older patients participating in occasional sports are particularly prone to tendon injuries.
What To Do:
Obtain a history that includes details of pain onset and potential precipitating factors. Include questions about general health that may reveal sources of a secondary tendinopathy, such as psoriasis, a sexually transmitted disease, a puncture wound, gout, or the use of a fluoroquinolone within the past 3 months.
Perform a physical examination that includes inspection and careful palpation while gently putting the tendon through its range of motion (as much as comfort allows). Palpation should reveal focal tenderness that essentially reproduces the patient’s pain. At the Achilles tendon, this may be 3 to 5 cm above the calcaneal insertion (classic midportion tendinopathy) or, less commonly, at the insertion (insertional tendinopathy) itself. The tenderness of patellar tendinopathy (jumper’s knee) is generally found on the inferior patellar pole of the proximal attachment of the patellar tendon and is best palpated when the knee is in about 30 degrees of flexion and the quadriceps muscle is totally relaxed. Calcific tendinitis in or around the rotator cuff tendons of the shoulder usually exhibits specific tenderness over the greater tuberosity of the proximal humerus. This tendinopathy usually has an abrupt onset of pain and can severely limit shoulder movement secondary to the severe pain. The cardinal signs of lateral and medial elbow tendinopathy are tenderness at the origins of the elbow extensors and flexors, respectively. To help rule out cervical disorders, the neck should be examined carefully in all cases of shoulder and elbow tendinopathy.
If there is swelling, erythema, fever, puncture of the skin, gonorrhea, or marked pain, you must first rule out infection. Send blood for complete blood count (CBC) and erythrocyte sedimentation rate (ESR) and request consultation. Consider gonococcal tenosynovitis and obtain a sexual history, recognizing that females can often have nonsymptomatic infections. If this is being considered in sexually active women, obtain appropriate cervical cultures (see Chapter 83).
Radiographs are usually of little diagnostic value. They may reveal calcifications, osteochondritis, or osteophytes that suggest chronic inflammation but do not necessarily correlate with symptoms. However, radiographic evidence of calcification within the shoulder, along with the clinical history and physical examination, can help to make the diagnosis of calcific tendinitis. The most common site of calcium deposition is within the supraspinatus tendon.
In most other cases of tendinopathy, many expert clinicians believe that a confident diagnosis can be made clinically, thus obviating the need for any imaging studies. In cases in which the history and examination may not be typical, both ultrasonography and magnetic resonance imaging provide additional information that may be helpful. The clinician must bear in mind that there are many cases in which abnormal tendon morphology does not parallel pain when interpreting imaging findings.
Instruct the patient to avoid the precipitating activity, and prescribe a nonsteroidal anti-inflammatory drug (NSAID) unless it is contraindicated by allergy, bleeding, gastritis, or renal insufficiency. The role of anti-inflammatory therapy, such as oral NSAIDs or steroids, remains controversial. Although no inflammatory infiltrates have been documented in histologic analyses of tendinopathic samples, anti-inflammatory medications do help to diminish pain and facilitate rehabilitation in cases of chronic tendinopathy and most certainly have a place in the management of insertional tendinitis and calcific tendinitis of the shoulder. One recent trial suggests that a 7-day treatment course with a once-daily dose of a 100-mg ketoprofen topical patch can provide pain relief without the adverse events associated with systemic delivery of a NSAID. (Keep in mind that this is more expensive than oral NSAIDs.)
Cryotherapy (ice) has also been shown to be useful to help facilitate therapy in tendinopathy.
With overuse injuries, occasionally complete rest or cessation of the training that caused the symptoms may be required for a short time to settle severe symptoms. Even splinting with use of a sling or providing crutches may help to prevent or minimize painful motion.
Because repair and remodelling of collagen fibers are stimulated by loading of the tendon, only very short courses of complete rest should be prescribed.
The AirCast AirHeel (DJO Global, Vista, Calif.) pneumatic compression dressing for the foot and ankle can provide pain relief with Achilles tendinopathy.
A patellofemoral brace with a patellar cutout and lateral stabilizer may improve patellar tracking and help in the recovery of jumper’s knee.
More time than expected is required for collagen turnover, repair, and remodelling; therefore patients and clinicians must understand that these conditions may take months, rather than weeks, to resolve.
Appropriate and progressive exercises represent the gold standard for tendon rehabilitation.
Operative treatment is recommended for patients who do not respond adequately to an extended trial of conservative treatment. Surgery for overuse tendinopathies usually involves excision of fibrotic adhesions and degenerated nodules, or decompression of the tendon by longitudinal tenotomies.
Do not inject corticosteroids directly into the tendon or provide repeat steroid injections, which may potentiate infection, lead to tendon atrophy, weaken the tendon, or cause it to rupture. Repeated subfascial or subcutaneous injections can result in atrophy of the skin and subcutaneous tissue and loss of pigmentation. Because overuse tendinosis is not an inflammatory condition, the rationale for using corticosteroids may need reassessment. Corticosteroids, however, provide short-term pain reduction by mechanisms that are poorly understood.
Do not confuse the Haglund deformity (pump bump), a superficial bursitis that forms a bony enlargement of the calcaneus where a low-cut shoe rubs over the heel, with Achilles tendinopathy. This is most often seen in adolescent females and is treated with changes in footwear, shoe padding, or, when necessary, orthotics.
Under the light microscope, normal tendon consists of dense, clearly defined, parallel, and slightly wavy collagen bundles. Histopathologic examination of symptomatic Achilles tendons reveals degeneration and disordered arrangement of collagen fibers.
Until recently, if a patient presented with a history of exercise-related pain and tenderness at one of the common sites of tendinopathy (the Achilles, patellar, rotator cuff, or elbow tendons), and if history and examination features suggested that pain was emanating from the tendon, the patient would most likely have been diagnosed as having “tendinitis,” an inflammatory condition of the tendon. Most of these conditions are truly tendinoses.
As long ago as 1976, Giancarlo Puddu of Rome examined the Achilles tendons of symptomatic runners and showed that inflammatory cells are absent. Others have shown that the major lesion in chronic Achilles tendinopathy “is a degenerative process characterized by a curious absence of inflammatory cells and a poor healing response.”
New nomenclature is reflective of the underlying histopathologic changes in patients with overuse tendon disorders and favors use of the term “tendinopathy” as a generic descriptor of clinical conditions. These include tendinosis (chronic degeneration), tendinitis (acute inflammation of the tendon), paratenonitis (inflammation of the outer layer of the tendon [paratenon] alone, whether or not the paratenon is lined by synovium), tenosynovitis (inflammation of the synovial tendon sheath), and partial and complete tendon ruptures (see Chapter 122).
Tendinosis can be associated with paratenonitis. The majority of overuse tendinopathies in athletes are the result of tendinosis, with collagen degeneration and fiber disorientation, increased mucoid ground substance, and an absence of inflammatory cells.
The etiology of Achilles tendon overuse injuries is multifactorial. Excessive repetitive overload of the tendon is, however, regarded as the main pathologic stimulus that leads to its tendinopathy. Whereas paratenonitis is characterized by “squeaky” crepitus, exquisite tenderness, and swelling that does not move with tendon action, chronic Achilles tendinopathy is notable for absence of crepitation and swelling, with focal tender nodules that move as the ankle is dorsiflexed and plantarflexed.
Another cause of posterior heel pain in the setting of overuse injury is retrocalcaneal bursitis, in which there is inflammation of the commonly afflicted bursa anterior to the insertion of the Achilles tendon on the calcaneus.
Achilles tendon disorders occur most often in athletes involved in running sports.
Patients suffering from jumper’s knee are usually tall athletes.
In children and adolescents, tendons are relatively stronger than the bones into which they insert. Osgood-Schlatter lesions are traction apophysitis of the tibial tubercle. The condition presents as localized tenderness and radiographic fragmentation in athletic adolescents between the ages of 8 to 13 (in girls) and 10 to 15 (in boys). These lesions are typically self-limiting.
It is thought that calcific tendinitis of the shoulder becomes acutely painful only when the calcium is undergoing resorption. This is one form of tendinopathy for which steroid injection may be beneficial. Gentle exercises with a physical therapist can help maintain range of motion.
Fluoroquinolone-induced tendinopathy can occur weeks to months following completion of a course of these antibiotics. This tendinitis is similar to the overuse injuries described. The Achilles tendon is most frequently affected, but any tendon complaint warrants inquiry regarding recent or distant fluoroquinolone use. Treatment is the same as it is for overuse tendinopathy, but subsequent fluoroquinolone use should be avoided. When any patient has tenosynovitis of more than one tendon, consider quinolone tendinopathy as well as gonococcal infection as possible causes.