Regional Pain Dr. B. G. Dharmanand M.D., D.M. (Rheumatology) Rheumatologist, Manipal Hospital ChanRe Rheumatology and Immunology Center, Bengaluru Dharmanand B.G. Regional Pain In Wagh S. (Ed). Rheumatology in Primary Care 1 st Edition KYA Foundation 2012; pp 91-102 Regional pain may be defined as pain and dysfunction arising from a single musculoskeletal region (e.g. shoulder pain, heel pain etc.). Regional pain syndromes excluding neck and back pain have a prevalence of 2-5%.These conditions, also known as soft tissue rheumatism, arise from soft tissues around the joints. Their classification is based on the anatomical region from which the pain arises. Though the precise cause for the regional pain cannot be ascertained most of the time, the following are considered to facilitate the development of regional pain syndromes : 1. Over work/ unaccustomed activities 2. Repetitive strain 3. Poor posture 4. Sports related injuries 5. Trauma/Surgery 6. Obesity 7. Benign joint hypermobility syndrome 8. Systemic rheumatic diseases 9. Infections and malignancy Approach to patient with regional pain When one is evaluating a regional pain, for example shoulder pain, it is prudent to consider the problem as shoulder regional pain rather than as shoulder joint pain. The pain may arise from shoulder joint itself or from adjoining structures such as ligaments, tendons and bursae. The pain may also be referred from a proximal joint or the myofascial structures around the joint (Table 1). 1
Table 1 Sources of regional pain Joint pain/arthritis Periarticular structures- ligaments, tendons, bursae Neurogenic pain Referred pain including myofascial pain syndrome Clinical history should include the site, nature and rhythm of pain and factors that aggravate or relieve pain. History of recent trauma or surgery and unaccustomed activity is important. Occupational history may help understanding the patient's symptoms. Poor job satisfaction is also associated with persistent regional pain syndromes like backache. Thus, some regional pain syndromes may be a surrogate for distress and predicaments of life. Physical examination should include musculoskeletal and neurological examination. Observation of skin color changes along with allodynia (painful response to non-noxious stimuli) and hyperesthesia point toward complex regional pain syndrome (CRPS), a condition previously known as reflex sympathetic dystrophy. Passive and active movements should be checked along with resisted active movements. Pain arising mainly on resisted movements suggests enthesial or tendon pathology. In diseases like carpal tunnel syndrome, the neuropathic quality of the symptoms (paraesthesia and tingling) helps us to suspect entrapment neuropathy. If the regional examination is normal, one should examine the immediate proximal joint since pain may be referred from the region above. Osteoarthritis of hip, for example, can present with knee pain. If the palpation of painful region does not elicit a nociceptive response, one needs to consider either a neuropathic or referred pain. Checking for generalized and localized hypermobility of the joints is important as it may predispose to soft tissue rheumatism. Since regional pains can be part of a systemic disease, a quick review of all the systems is also essential. Red flag symptoms which should alert one to do further evaluation or referrals are given in Table 2. Table 2 'Red Flags' in regional pain Fever Weight loss Night sweats Major trauma Unrelenting pains/ nocturnal pains Infection Present or past cancer Radiotherapy Immunosuppression Widespread neurological signs Few common regional pains are discussed in this chapter. 2
Shoulder pain Pain in the shoulder region is common. It can result in considerable difficulty in self care activities like dressing, washing and hygiene. Acute subacromial bursitis and shoulder capsulitis can disturb sleep due to difficulty in lying on the affected side. Usually, the patient would point to midlateral arm as the site of pain when there is shoulder pathology. History of diabetes mellitus, recent stroke and myocardial infarction are common in those presenting with frozen shoulder. In frozen shoulder (pericapsulitis) and arthritis, both active and passive movements are equally restricted, whereas in rotator cuff tendonitis, active movements are more restricted than passive movements. A painful arc seen on abduction indicates an impingement syndrome where supraspinatus tendon gets impinged between lower aspect of acromion and the humerus. Pain reproduced on resisted movements of shoulder help to identify the tendon which could be affected. For example, anterior shoulder pain on resisted elbow flexion would suggest biceps tendonitis. Pain arising from lesions in sternoclavicular joint and cervical spine can be referred to shoulder region. If the shoulder examination is normal, surrounding muscles should be examined for trigger points. Common causes of shoulder region pain include: Joint pathology Periarticular causes Referred pain Frozen shoulder Rotator cuff tendonitis Cervical radiculitis Arthritis (many causes) Subacromial bursitis Cardiac pain Acromioclavicular arthritis Myofascial pain syndrome Sub-diaphragmatic pathology Frozen shoulder (Adhesive capsulitis) is usually self limiting but recovery may be incomplete. It usually takes between 6 months to 2 years to regain meaningful recovery of shoulder movements. Non-steroidal anti-inflammatory drugs (NSAIDs) relieve pain. They should be used with caution in diabetics. Physiotherapy with local heat and mobilization exercises remains the cornerstone of the treatment. Intra-articular steroid injections are shown to reduce the pain in short term and thus help faster rehabilitation. Acromioclavicular pain, subacromial bursitis and rotator cuff tendonitis also respond to local steroid injections. Myofascial pain syndrome (MFPS) is usually treated with massage and stretch technique. Dry needling or injection of local anesthetic of the trigger points producing MFPS also help to deactivate the trigger points. Correcting the posture, advice on correct sleeping techniques and preventive exercises also are part of MFPS management. 3
Elbow pain Elbow is another region, where soft tissue pains occur commonly. In most of the cases, the cause cannot be made out. Though commonly called tennis elbow, lateral epicondylitis does not occur exclusively in those who play tennis! Occupational and recreational history is important to ascertain the etiology. Causes of elbow pain are as follows: Elbow arthritis Lateral epicondylitis (Tennis elbow) Medial epicondylitis (Golfer's elbow) Referred pain from shoulder / neck Triceps enthesitis Olecranon bursitis Myofascial trigger points around extensor muscles Lateral epicondylitis (Tennis elbow) is an enthesitis of the common origin of extensor tendons of the wrist. The pain is usually felt on the lateral part of elbow, mainly on gripping an object and lifting weight. Sports activity may become progressively difficult, as also household activities. Lateral epicondyle is tender on palpation. Resisted wrist extension and passive wrist flexion may elicit pain in the lateral epicondyle. Acute pain may be managed by local ice application, rest and NSAIDs. Chronic pain may respond to activity modification, local deep friction massage, elbow support and taping. Stretching exercises and eccentric loading exercises for the extensor muscles help healing and may prevent recurrences. Local glucocorticoid injection into the common extensor origin may be needed for symptomatic relief. Recurrences are treated similarly. In refractory cases, it is prudent to look for trigger points in the muscle belly. These may respond to massage and stretching or trigger point needling. Medial epicondylitis (Golfer's elbow) is a similar enthesitis affecting common origin of flexor muscles of the wrist. Pain is felt in the medial part of elbow and medial epicondyle is tender to palpation. Resisted wrist flexion and passive wrist extension may reproduce the symptoms. This condition is treated on the similar lines as those of lateral epicondylitis. Wrist and hand pain Common causes of wrist and hand pain are as follows: de Quervain's tenosynovitis Intersection syndrome Tenosynovitis of common digital extensors Carpal tunnel syndrome Trigger fingers/ Trigger thumb Ganglion 4
de Quervain's tenosynovitis involves the common tendon sheath of extensor pollicis brevis and abductor pollicis longus. This leads to pain and swelling along base of the thumb. Pain may radiate along involved muscles to the arm. This condition is usually associated with overuse and pregnancy. Mild cases respond to local heat, ultrasound massage and splinting. Steroid injection into common tendon sheath is remarkably effective. Surgery is rarely required. Intersection syndrome is an inflammatory condition occurring at the intersection of radial wrist extensors and the tendons of first dorsal compartment muscles. Pain and swelling are noticed on the radiodorsal aspect of distal forearm. Pain and crepitus during active as well as passive wrist movements is typical. It is usually secondary to sports and work related activities. Conservative treatment with ice application, splint and steroid injection helps in reducing the symptoms. Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Pain and paresthesia involving the lateral 2/3 rd of the hand is common. Activities like using computer keyboard, musical instruments, talking on a phone and writing could be very symptomatic. Pain may radiate to forearm. Nocturnal awakening due to pain is also typical of CTS. Phalen's sign (flexion of wrist for a minute elicits numbness in area of median nerve) and Tinel's sign (tapping on volar surface of wrist causes shooting pain in index finger) are usually positive. Nerve conduction study is confirmatory. CTS could be the first manifestation of rheumatoid arthritis and hypothyroidism. It also occurs more often in pregnancy. Activity modification, splints to keep the wrist in neutral or slightly extended position helps to relieve symptoms. Drugs like gabapentin, pregabalin and tricyclic antidepressants reduce the symptoms and improve sleep. Intralesional glucocorticoid injection is usually very effective. Late and refractory cases require surgery to relieve nerve compression. Trigger fingers (locking when flexed followed by release like a trigger) are treated with local steroid injections or surgery. They are sometimes associated with diabetes, hypothyroidism and rheumatoid arthritis. Ganglions are benign cystic swellings and require no treatment. Local injection and surgery would help painful cases. Recurrences are not uncommon. Knee pain Ligament injuries are common during sports. Pain starts immediately after injury and may be difficult to localize during initial stages. Collateral ligament pain is felt on either side of the knee whereas cruciate ligament is felt deep inside. Pain is present at rest and worsened by activities. Knee may be swollen and warm in cruciate ligament injuries. Meniscal tears, common in sports activities and in the elderly, can occur due to sudden twisting of knee 5
while bearing weight. Mechanical symptoms such as locking and buckling are common in meniscal tears. Baker's cyst in the posterior fossa can be large enough to cause discomfort and restricted movements. The cyst usually resolves on its own though it may rupture leading to severe pain and diffuse swelling of calf. Ultrasound examination is useful to differentiate this condition from venous occlusion. Large cysts may require needle aspiration. Bursitis is common around knee. Suprapatellar bursa is in direct communication with knee and swells in knee effusion. Prepatellar bursitis (housemaid's knee) causes pain and swelling over patella but does not restrict knee movements. Infrapatellar bursitis (jumper's knee) and anserine bursitis (over upper medial surface of tibial shaft) are also common. Bursitis is treated with rest, ice compresses, NSAIDs and local glucocorticoid injections. Septic bursitis warrants suitable antibiotic and surgical excision. Chondromalacia patellae is a condition of softening and fibrillation of patellar cartilage. Malalignment of knee or ankle-foot complex predispose to this condition. Anterior knee pain is aggravated by climbing or descending stairs, prolonged sitting, squatting, running and jumping. The condition is managed by rest, icepacks, NSAIDs and physical therapy. Ankle and foot pain Ankle and foot pains are common and cause considerable problems for ambulation. Important causes of ankle and foot pain are as follows: Hind foot pain Mid foot pain Fore foot pain Achilles tendonitis/ Osteoarthritis Hallus valgus/varus enthesitis Retrocalcaneal bursitis Ganglion Metatarsalgia Plantar fasciitis Tarsal tunnel syndrome Sinus tarsi syndrome Calcaneal fracture Morton's neuroma Corns and callosities Plantar fasciitis and Achilles tendonitis are the most common causes of ankle and heel pain. The severity may range from mild pain after prolonged rest and after getting up in the morning to severe difficulty in ambulation. The cause is usually unknown. Recent increase in activity like walking long distances, walking on uneven surfaces, ill-fitting shoes, recent gain in weight and sports related injuries can precipitate these enthesitic disorders. Rarely, these may be the presenting features of ankylosing spondylitis and related spondyloarthritides. Flat feet and tight Achilles tendon and calf muscles may contribute to the development of these disorders. Plantar fasciitis usually causes medial heel pain, worst 6
in the morning and after rest. Prolonged standing may worsen the symptoms. Achilles tendonitis causes posterior heel pain with similar characteristics as plantar fascia pain. These are treated with rest, activity modification and foot wear prescription. Foot wear with microcellular rubber soles is commonly prescribed. Silicon heel cushions and insoles and medial longitudinal arch support are commonly advised in correctable flat feet. High heel footwear needs to be avoided. They are associated with fore foot pain. Raising the heel by an inch may reduce the strain on Achilles insertion on walking. NSAIDs provide symptom relief but are not suitable for long term use. Local heat and exercises for the small muscles of feet may help plantar fasciitis. Stretching the tight Achilles tendon may help heal plantar fasciitis. An intralesional glucocorticoid injection gives short term symptom relief in plantar fasciitis. Glucocorticoid injections should be avoided close to Achilles insertion or tendon for fear of causing tendon rupture. Eccentric loading exercises for Achilles tendon are shown to accelerate healing of Achilles tendonitis. When local examination is unremarkable, one needs to look for trigger points in calf muscles. Management of trigger points will reduce symptoms in these cases. General principles of management of regional pain 1. Correct diagnosis usually leads to appropriate management strategies. 2. Most soft tissue rheumatisms are self limiting. 3. Some can become chronic and may cause significant functional limitations. 4. Regional pains which are part of a systemic illness require appropriate therapy. 5. Particular attention should be paid to correctable or modifiable etiological factors. 6. Ergonomic advice and correct sports technique may prevent recurrences. 7. Acute pains respond to rest, ice application, elevation and splinting/taping. Short term NSAIDs are also useful. 8. Physiotherapy is main treatment strategy. Local heat, exercise prescriptions, therapeutic massage and stretching are some of the modalities used by physiotherapists. 9. Local glucocorticoid injection promptly provides short term relief. Its long term benefits are uncertain. Not more than 3 injections to the same site and at intervals of not less than 3 months between injections are generally recommended. 10. Trigger point injections with local anesthetics and sometimes dry needling of trigger points are effective treatments for MFPS. **** 7