Tenosynovitis and Peritendinitis

Wrist and finger extensors and flexors

In the wrist and hand the tendons are surrounded by tendon sheaths, which are tubular structures containing fluid to provide lubrication and protection for the tendon. An inflammation of the tendon sheath is called tenosynovitis. Inflammation of the site where the muscle meets the tendon is called peritendinitis The location of wrist tenosynovitis is at the tendon sheath area in the wrist, and the location of peritendinitis is above the tendon sheath area in the forearm. Insertion tendinitis denotes an inflammation of the tendon at the site where it meets the bone (figure 1).

Figure 1. The muscle-tendon unit.

The terminology for the diseases of the tendon and its adjacent structures is often used loosely, and sometimes “tendinitis” has been used for all painful conditions in the forearm-wrist-hand region, regardless of the type of clinical appearance. In North America an umbrella diagnosis “cumulative trauma disorder” (CTD) has been used for all upper extremity soft tissue disorders believed to be caused, precipitated or aggravated by repetitive exertions of the hand. In Australia and some other countries, the diagnosis of “repetitive strain injury” (RSI) or “overuse injury” has been used, while in Japan the concept of “occupational cervicobrachial disorder” (OCD) has covered soft-tissue disorders of the upper limb. The two latter diagnoses include also shoulder and neck disorders.

The occurrence of tenosynovitis or peritendinitis varies widely according to the type of work. High incidences have been reported typically among manufacturing workers, such as food-processing workers, butchers, packers and assemblers. Some recent studies show that high incidence rates exist even in modern industries, as shown in table 1. Tendon disorders are more common on the back side than on the flexor side of the wrist. Upper extremity pain and other symptoms are prevalent also in other types of tasks, such as modern keyboard work. The clinical signs that keyboard workers present are, however, rarely compatible with tenosynovitis or peritendinitis.

Table 1. Incidence of tenosynovitis/peritendinitis in various populations.

Frequent repetition of work movements and high force demands on the hand are powerful risk factors, especially when they occur together (Silverstein, Fine and Armstrong 1986). Generally accepted values for acceptable repetitiveness and use of force do not, however, yet exist (Hagberg et al. 1995). Being unaccustomed to hand-intensive work, either as a new worker or after an absence from work, increases the risk. Deviated or bent postures of the wrist at work and low environmental temperature have also been considered as risk factors, although the epidemiological evidence to support this is weak. Tenosynovitis and peritendinitis occur at all ages. Some evidence exists that women might be more susceptible than men (Silverstein, Fine and Armstrong 1986). This has, however, been difficult to investigate, because in many industries the tasks differ so widely between women and men. Tenosynovitis may be due to bacterial infection, and some systemic diseases such as rheumatoid arthritis and gout are often associated with tenosynovitis. Little is known about other individual risk factors.

In tenosynovitis the tendon sheath area is painful, especially at the ends of the tendon sheath. The movements of the tendon are restricted or locked, and there is weakness in gripping. The symptoms are often worst in the morning, and functional ability improves after some activity. The tendon sheath area is tender on palpation, and tender nodes may be found. Bending of the wrist increases pain. The tendon sheath area may also be swollen, and bending the wrist back and forth may produce crepitation or crackling. In peritendinitis, a typical fusiform swelling is often visible on the backside of the forearm.

Tenosynovitis of the flexor tendons at the palmar aspect of the wrist may cause entrapment of the median nerve as it runs through the wrist, resulting in carpal tunnel syndrome.

The pathology at an acute stage of the disease is characterized by the accumulation of fluid and a substance called fibrin in the tendon sheath in tenosynovitis, and in the paratenon and between the muscle cells in peritendinitis. Later, cell growth is noticed (Moore 1992).

It should be emphasized that tenosynovitis or peritendinitis that is clinically identifiable as occupational is found in only a minor proportion of cases of wrist and forearm pain among working populations. The majority of workers first seek medical attention with the symptom of tenderness to palpation as the sole clinical finding. It is not fully known whether the pathology in such conditions is similar to that in tenosynovitis or peritendinitis.

In the prevention of tenosynovitis and peritendinitis, highly repetitive and forceful work movements should be avoided. In addition to attention to work methods, work organizational factors (the quantity and pace of work, pauses and work rotation) also determine the local load imposed on the upper limb, and the possibility of introducing variability to work by affecting these factors should be considered as well. New workers and workers returning from a leave or changing tasks should be gradually accustomed to repetitive work.

For industrial workers with hand-intensive tasks, the typical length of sick leave due to tenosynovitis or peritendinitis has been about ten days. The prognosis of tenosynovitis and peritendinitis is usually good, and most workers are able to resume their previous work tasks.

De Quervain’s tenosynovitis

De Quervain’s tenosynovitis is a stenosing (or constricting) tenosynovitis of the tendon sheaths of the muscles that extend and abduct the thumb at the outer aspect of the wrist. The condition occurs in early childhood and at any age later. It may be more common among women than among men. Prolonged repetitive movements of the wrist and blunt trauma have been suggested as causative factors, but this has not been epidemiologically investigated.

The symptoms include local pain at the wrist and weakness of grip. The pain may sometimes extend into the thumb or up into the forearm. There is tenderness and eventual thickening on palpation at the constriction site. Sometimes nodular thickening may be visible. Bending the wrist towards the little finger with the thumb flexed in the palm (Finkelstein’s test) typically exacerbates the symptoms. Some cases show triggering or snapping upon moving the thumb.

The pathological changes include thickened outer layers of the tendon sheaths. The tendon may be constricted and show enlargement beyond the site of constriction.

Stenosing tenosynovitis of the fingers

The tendon sheaths of the flexor tendons of the fingers are held close to the joint axes by tight bands, called pulleys . The pulleys may thicken and the tendon may show nodular swelling beyond the pulley, resulting in stenosing tenosynovitis often accompanied by painful locking or triggering of the finger. Trigger finger or trigger thumb have been used to denote such conditions.

The causes of trigger finger are largely unknown. Some cases that occur in early childhood are likely to be congenital, and some seem to appear after trauma. Trigger finger has been postulated to be caused by repetitive movements, but no epidemiological studies to test this have been carried out.

The diagnosis is based on local swelling, eventual nodular thickening, and snapping or locking. The condition is often encountered in the palm at the level of the metacarpal heads (the knuckles), but may occur also elsewhere and in multiple sites.

Osteoarthrosis

The prevalence of radiographically detectable osteoarthrosis in the wrist and hand is rare in the normal population under the age of 40, and is more common among men than women (Kärkkäinen 1985). After the age of 50, hand arthrosis is more prevalent among women than among men. Heavy manual labour with and without exposure to low-frequency (below 40 Hz) vibration have been associated, although not consistently, with excess prevalence of osteoarthrosis in the wrist and hand. For higher frequencies of vibration, no excess joint pathology has been reported (Gemne and Saraste 1987).

Osteoarthrosis of the first joint between the base of the thumb and the wrist (carpometacarpal joint) occurs fairly commonly among the general population and is more common among women than men. Osteoarthrosis is less common in the knuckles (metacarpo-phalangeal joints), with the exception of the meta- carpophalangeal joint of the thumb. Aetiology of these disorders is not well known.

Osteoarthrotic changes are common in the joints closest to the fingertip (distal interphalangeal joints of fingers), in which the age-adjusted prevalence of radiographically detectable changes (mild to severe) in different fingers varies between 9 and 16% among the men and 13 and 22% among the women of a normal population. Distal interphalangeal osteoarthrosis can be detected by clinical examination as nodular outgrowths on the joints, called Heberden’s nodes. In a Swedish population study among 55-year-old women and men, Heberden’s nodes were detected in 5% of men and 28% of women. Most subjects showed changes in both hands. The presence of Heberden’s nodes showed a correlation with heavy manual labour (Bergenudd, Lindgärde and Nilsson 1989).

Joint load associated with the manipulation of tools, repetitive movements of the hand and arm possibly together with minor traumatization, loading of the joint surfaces in extreme postures, and static work have been considered as possible causative factors for wrist and hand osteoarthrosis. Although osteoarthrosis has not been considered specific to low-frequency vibration, the following factors might play a role as well: damage of the joint cartilage from shocks from the tool, additional joint load associated with a vibration- induced increase in the need for joint stabilization, the tonic vibration reflex and a stronger grip on the tool handle induced when sensitivity to touch is diminished by vibration (Gemne and Saraste 1987).

The symptoms of osteoarthrosis include pain during movement in the initial stages, later also during rest. Limitation of motion in the wrist does not markedly interfere with work activities or other activities of daily living, whereas osteoarthrosis of the finger joints may interfere with gripping.

To avoid osteoarthrosis, tools should be developed that help to minimize heavy manual labour. Vibration from tools should be minimized as well.

Compartment Syndrome

The muscles, nerves and blood vessels in the forearm and hand are located in specific compartments limited by bones, membranes and other connective tissues. Compartment syndrome denotes a condition in which the intracompartmental pressure is constantly or repeatedly increased to a level at which the compartmental structures may be injured (Mubarak 1981). This may occur after trauma, such as fracture or crush injury to the arm. Compartment syndrome after strenuous exertion of the muscles is a well-known disease in the lower extremity. Some cases of exertional compartment syndrome in the forearm and hand have also been described, although the cause of these conditions is not known. Neither have generally accepted diagnostic criteria nor indications for treatment been defined. The afflicted workers have usually had hand-intensive work, although no epidemiological studies on the association between work and these diseases have been published.

The symptoms of compartment syndrome include tenseness of the fascial boundaries of the compartment, pain during muscle contraction and later also during rest, and muscle weakness. In clinical examination, the compartment area is tender, painful on passive stretching, and there may be diminished sensitivity in the distribution of the nerves running through the compartment. Intracompartmental pressure measurements during rest and activity, and after activity, have been used to confirm the diagnosis, but full agreement on normal values does not exist.

Intracompartmental pressure increases when the volume of the contents increases in the rigid compartment. This is followed by an increase in venous blood pressure, a decrease in the arterial and venous blood pressure difference which in turn affects blood supply of the muscle. This is followed by anaerobic energy production and muscle injury.

The prevention of exertional compartment syndrome includes avoiding or restricting the activity causing the symptoms to a level that can be tolerated.

Ulnar Artery Thrombosis(Hypothenar Hammer Syndrome)

The ulnar artery may undergo damage and subsequent thrombosis and occlusion of the vessel in the Guyon’s canal on the inner (ulnar) aspect of the palm. A history of repeated trauma to the ulnar side of the palm (hypothenar eminence), such as intensive hammering or using the hypothenar eminence as a hammer, has often preceded the disease (Jupiter and Kleinert 1988).

The symptoms include pain and cramping and cold intolerance of the fourth and fifth fingers. Neurological complaints may also be present, such as aching, numbness and tingling, but the performance of the muscles is usually normal. On clinical examination, coolness and blanching of the fourth and fifth fingers may be observed, as well as nutritional changes of the skin. The Allen’s test is usually positive, indicating that after compressing the radial artery, no blood flows to the palm via the ulnar artery. A palpable tender mass may be found in the hypothenar region.

Dupuytren’s Contracture

Dupuytren’s contracture is a progressive shortening (fibrosis) of the palmar fascia (connective tissue joining the flexor tendons of the fingers) of the hand, leading to permanent contracture of the fingers in a flexion posture. It is a common condition in people of North-European origin, affecting about 3% of the general population. The prevalence of the disease among the men is twice that among the women, and may be as high as 20% among males aged over 60. Dupuytren’s contracture is associated with epilepsy, type 1 diabetes, alcohol consumption and smoking. There is evidence for an association between vibration exposure from hand-held tools and Dupuytren’s contracture. The presence of the disease has been associated also with single injury and heavy manual labour. Some evidence exists to support an association between heavy manual work and Dupuytren’s contracture, whereas the role of single injury has not been adequately addressed (Liss and Stock 1996).

The fibrotic change appears first as a node. Later the fascia thickens and shortens, forming a chordlike attachment to the digit. As the process progresses, the fingers turn to permanent flexion. The fifth and fourth fingers are usually affected first, but other fingers also may be involved. Knuckle pads may be seen on the back side of the digits.

Wrist and Hand Ganglia

A ganglion is a soft, liquid-filled small sac; ganglia represent the majority of all soft tissue tumours of the hand. Ganglia are common, although the prevalence in populations is not known. In clinical populations, women have shown a higher prevalence than men, and both children and adults have been represented. Controversy exists on the causes of ganglia. Some consider them inborn while others believe that acute or repeated trauma play a role in their development. Different opinions exist also on the development process (Angelides 1982).

The most typical location of the ganglion is at the outer aspect of the back of the wrist (dorsoradial ganglion), where it can present as a soft, clearly visible formation. A smaller dorsal ganglion may not be noticeable without flexing the wrist markedly. The volar wrist ganglion (at the palmar aspect of the wrist) is typically located on the outer side of the tendon of the radial flexor of the wrist. The third commonly occurring ganglion is located at the pulley of the finger flexor tendon sheath at the level of the knuckles. A volar wrist ganglion may cause entrapment of the median nerve in the wrist, resulting in carpal tunnel syndrome. In rare cases a ganglion may be located in the ulnar canal (Guyon’s canal) in the inner palm and cause entrapment of the ulnar nerve.

The symptoms of wrist ganglia include local pain typically during exertion and deviated postures of the wrist. The ganglia in the palm and fingers are usually painful during gripping.

Disorders of Motor Control of the Hand(Writer’s Cramp)

Tremor and other uncontrolled movements may disturb hand functions which demand high precision and control, such as writing, assembly of small parts and playing musical instruments. The classical form of the disorder is writer’s cramp . The occurrence rate of writer’s cramp is not known. It affects both sexes and seems to be common in the third, fourth and fifth decades.

The causes of writer’s cramp and the related disorders are not fully understood. A hereditary predisposition has been suggested. The conditions are nowadays considered as a form of task-specific dystonia. (Dystonias are a group of disorders characterized by involuntary sustained muscle contractions, causing twisting and repetitive movements, or abnormal postures.) Pathological evidence of brain disease has not been reported for patients with writer’s cramp. Electrophysiological investigations have revealed abnormally prolonged activation of muscles involved in writing, and excess activation of those muscles that are not directly involved with the task (Marsden and Sheehy 1990).

In writer’s cramp, usually painless muscle spasm appears immediately or shortly after starting to write. The fingers, wrist and hand may assume abnormal postures, and the pen is often gripped with excessive force. The neurological status may be normal. In some cases an increased tension or tremor of the affected arm is observed.

Some of the subjects with writer’s cramp learn to write with the non-dominant hand, and a small proportion of these do develop cramp in the non-dominant hand as well. Spontaneous healing of writer’s cramp is rare.

Back

The hip joint is a ball-and-socket joint surrounded by ligaments, strong muscles and bursae. The joint is weight bearing and has both high intrinsic stability and a wide range of motion. In young people pain in the hip region usually originates in the muscles, tendon insertions or bursae, while in older people, osteoarthrosis is the predominant disorder causing hip pain.

The knee is a weight-bearing joint that is important for walking, standing, bending, stooping and squatting. The knee is rather unstable and depends for support on ligaments and strong muscles as shown in figure 1. There are two joints in the knee, the femorotibial and the femoropatellar. On both inner and outer side of the joint there are strong ligaments, and in the centre of the femorotibial joint are the cruciate ligaments, which give stability and assist in the normal mechanical function of the knee. The menisci are curved, fibrocartilaginous structures that lie between the femoral (femoral condyles) and the tibial bones (tibial plateau). The knee joint is both stabilized and empowered by muscles that originate above the hip joint and at the shaft of the femur and are inserted upon bony structures below the knee joint. Around the knee joint there is a synovial capsule, and the joint is protected by several bursae.

Figure 1. The knee.

All these structures are easily hurt by trauma and overuse, and medical treatment for knee pain is rather common. Osteoarthrosis of the knee is a common disorder among the elderly, leading to pain and disability. In younger people, patellar bursitis and patellofemoral pain syndromes like a painful pes anserinus are rather common.

Osteoarthrosis

Osteoarthrosis (OA) is a common degenerative joint disorder in which the cartilage is more or less destroyed and the structure of the underlying bone is affected. Sometimes it is accompanied by few symptoms, but usually OA causes suffering, changes in ability to work and a decreased quality of life. Changes in the joint can be seen on x ray, and an OA sufferer usually seeks medical care because of pain, which is present even at rest, and a diminished range of motion. In severe cases, the joint may become totally stiff, and even destroyed. Surgery to replace a destroyed joint and replace it with a prosthesis is well developed today.

Studying the causes of osteoarthrosis of the hip is difficult. The onset of the disorder is usually hard to pinpoint; the development is usually slow and insidious (that is, one doesn’t necessarily know it is happening). The end point, for research purposes, can be different things, varying from slight changes in x rays to symptomatic disorders that require surgery. Indeed the end points used to identify the condition may differ because of different traditions in different countries, and even between different clinics in the same town. These factors cause problems in the interpretation of research studies.

Epidemiological research tries to identify associations between exposures such as physical load, and outcomes, such as osteo-arthrosis. When combined with other knowledge, it is possible to find associations that could be considered causal, but the cause-effect chain is complicated. Osteoarthrosis is common in every population, and one must remember that the disorder exists among persons with no known hazardous exposure, while there are healthy subjects in the group with high and well-known harmful exposure. Unknown paths between exposure and disorder, unknown health factors, genetics and selection forces may be a few of the contributors to that.

Individual risk factors

Age: The occurrence of arthrosis increases with age. X-ray investigations of osteoarthrosis of different joints, mainly the hip and the knee, have been made in different populations and the prevalences found to vary. The explanation might be ethnic differences or variations in investigation techniques and diagnostic criteria.

Congenital and developmental diseases and changes: Early changes in the joint, such as congenital malformations, those caused by infections and so on, lead to an earlier and faster progression of osteoarthrosis of the hip. Knock-knees (varus) and bandy-legs (valgus) put an uneven distribution of forces on the knee joint, for example, which can have some importance for arthrosis development.

Heredity: Hereditary factors are present for osteoarthrosis. For example, osteoarthrosis of the hip is a rare disease among people of Asian origin but more common among Caucasians, which suggests a hereditary factor. Osteoarthrosis in three or more joints is called generalized osteoarthrosis and has a hereditary pattern. The hereditary pathway for osteoarthrosis of the knee is not very well known.

Overweight: Overweight can probably cause osteoarthrosis of the knee and hip. The relationship between overweight and knee osteoarthrosis has been shown in large epidemiological studies of the general population, such as the National Health and Nutrition Examination Survey (NHANES) and Framingham study in the United States. The association was strongest for women but existed even for men (Anderson and Felson 1988; Felson et al. 1988).

Trauma: Accidents or causes of trauma or injury, especially those that interfere with the mechanics and circulation of the joint and ligament, can give rise to an early osteoarthrosis.

Sex and oestrogen use: Osteoarthrosis of the hip and knee seems to be equally distributed among men and women. From a study on female participants in the Framingham study, it was concluded that oestrogen use in women is associated with a modest but insignificant protective effect against osteoarthrosis of the knee (Hannan et al. 1990).

Mechanical load

Experimental studies in monkeys, rabbits, dogs and sheep have shown that compression forces on a joint, especially when it is held in an extreme position, with or without simultaneous shifting loads, can lead to changes in the cartilage and bone similar to those of osteoarthrosis in human beings.

Sports activities: Participation in sports can increase the load on different joints. The risk of trauma is also increased. On the other hand, however, good muscle function and coordination are developed at the same time. Few data are available as to whether participating in sports prevents trauma or is harmful to the joints. Data drawn from good scientific studies are very limited, and some are described here. Several studies of soccer players have shown that both professionals and amateurs have more osteoarthrosis of the hip and knee than the general male population. For example, one Swedish study of 50- to 70-year-old men with a severe osteoarthrosis who were compared with healthy men in the same age group, showed that the men with osteoarthrosis had been more heavily involved in sports activities in their youth. Track and field, racket sports, and soccer seemed to be most harmful (Vingård et al. 1993). In the scientific literature there are other studies that have not shown any differences between athletes and those who do not participate in sports. However most of them are performed on still active athletes and are thus not conclusive.

Workload factors

The aetiology of osteoarthrosis of the knee and hip is, as for all diseases, complex and multifactorial. Recent well-performed studies have shown that physical load on the joint from occupational exposures will play a role as a contributing cause for the development of premature osteoarthrosis.

Most epidemiological studies concerning physical workload are cross-sectional and carried out on occupational groups without making individual exposure assessments. These serious methodological problems make generalizing the results of such studies extremely difficult. Farmers have been found to have more osteoarthrosis of the hip than other occupational groups in several studies. In a Swedish study of 15,000 farmers, farmers’ wives and other farm workers were asked about past x-ray examinations in which the hip joint could be seen. Among the 565 men and 151 women who had been examined, hip joints were studied using the same criteria and the same investigator as in a population study from Sweden 1984. The distribution of osteoarthrosis of the hip among male farmers and the male population of Malmö is shown in table 1 (Axmacher and Lindberg 1993).

Table 1. Prevalence of primary osteoarthrosis of the hip among male farmers and population of different age groups in the city of Malmö.

N = Number of men studied; cases = men with osteoarthrosis of the hip.
Source: Axmacher and Lindberg 1993.

In addition to farmers, construction workers, food-processing workers (grain-mill workers, butchers and meat preparers), firefighters, mail carriers, shipyard workers and professional ballet dancers have all been found to be at an increased risk of hip osteoarthrosis. It is important to realize that an occupational title alone does not adequately describe the stress on a joint—the same job type can mean different loads for different workers. Further, the load of interest in a study is the exact pressure placed on a joint. In a study from Sweden, physical workload has been quantified retrospectively through individual interviews (Vingård et al. 1991). Men with high physical load exposures due to their occupations up to the age of 49 had more than double the risk for developing osteoarthrosis of the hip compared to those with low exposure. Both dynamic exposures, such as heavy lifting, and static exposure, such as prolonged sitting in a twisted position, seemed to be equally harmful to the joint.

The risk of knee osteoarthrosis has been found to be increased in coal miners, dockers, shipyard workers, carpet and floor layers and other construction workers, firefighters, farmers and cleaners. Moderate to heavy physical demands at work, knee bending and traumatic injury increase the risk.

In another English study from 1968, dockers were found to have more osteoarthrosis of the knee than civil servants in sedentary occupations (Partridge and Duthie 1968).

In Sweden, Lindberg and Montgomery investigated workers in a shipyard and compared them to office workers and teachers (Lindberg and Montgomery 1987). Among shipyard workers 3.9% had gonarthrosis, compared to 1.5% among office workers and teachers.

In Finland, Wickström compared concrete reinforcement workers with painters, but no differences in disability from the knees were found (Wickström et al. 1983). In a later Finnish study, knee disorders in carpet and floor layers and painters were compared (Kivimäki, Riihimäki and Hänninen 1992). Knee pain, knee accidents, and treatment regimes for the knees, as well as osteophytes around the patella, were more common among carpet and floor layers than among the painters. The authors suggest that kneeling work increases the risk of knee disorders and that the changes observed in x rays might be an initial sign of knee degeneration.

In the United States, factors associated with osteoarthrosis of the knee in the first National Health and Nutrition Examination Survey (NHANES 1) were examined for a total of 5,193 men and women aged 35 to 74 years, 315 of whom had x-ray-diagnosed osteoarthrosis of the knee (Anderson 1988). In investigating occupational load the authors characterized the physical demands and knee-bending stress from occupational titles in US Department of Labor Dictionary of Occupational Titles. For both men and women, for those whose jobs were described as involving a lot of knee-bending, the risk for developing an osteoarthrosis of the knee was more than double that for those without such jobs. When controlling for age and weight in the statistical analysis, they found that 32% of the osteoarthrosis of the knee occurring in these workers was attributable to occupation.

In the Framingham study in the United States, subjects from Framingham, a town outside Boston, have been followed in an epidemiological study for more than 40 years (Felson 1990). Occupational status was reported for the years 1948–51 and 1958–61 and the results of x rays looking for radiographic osteo- arthrosis of the knee during the years 1983–85. Each subject’s job was characterized by its level of physical demand and whether the job was associated with knee-bending. This study also found that the risk for developing osteoarthrosis of the knee was doubled for those with a lot of knee bending and at least medium physical demands in their occupation.

In a study from California the roles of physical activity, obesity and knee injury on the development of severe osteoarthrosis of the knee was evaluated (Kohatsu and Schurman 1990). Forty-six people with gonarthrosis and 46 healthy people from the same community were studied. The persons with osteoarthrosis were two to three times more likely than the controls to have performed moderate to heavy work earlier in life and 3.5 times more likely to have been obese at the age of 20. They were almost five times more likely to have had a knee injury. There was no difference in the leisure time activities reported in the two groups.

In a register-based cohort study from Sweden (Vingärd et al. 1991) subjects born between 1905 and 1945, living in 13 of the 24 counties in Sweden in 1980 and reporting that they held the same blue-collar occupation in the censuses of 1960 and of 1970, were studied. The blue-collar occupations reported were then classified as to whether they were associated with high (more than average) or low (less than average) load on the lower extremity. During 1981, 1982 and 1983 it was determined whether the study population sought hospital care for osteoarthrosis of the knee. Firefighters, farmers and construction workers had an elevated relative risk among men to develop osteoarthrosis of the knee. Among women, cleaners were found to be at greater risk.

Chondromalacia patellae

A special case of osteoarthrosis is chondromalacia patellae, which often starts in the young. It is a degenerative change in the cartilage on the back of the patella bone. The symptom is pain in the knee, especially while bending it. Among sufferers, the patella is very tender when tapped, and especially if pressure is put on it. The treatment is quadriceps muscle training and, in severe cases, surgery. The connection to occupational activity is unclear.

Patellar bursitis

In the knee, there is a bursa between the skin and the patella. The bursa, which is a sac containing fluid, can be subject to mechanical pressure during kneeling and thus become inflamed. Symptoms are pain and swelling. A substantial amount of serous fluid can be aspirated from the bursa. This disorder is rather common among occupational groups that do a lot of kneeling. Kivimäki (1992) has investigated soft-tissue changes in the front of the knee using ultrasonography in two occupational groups. Among carpet and floor layers 49% had thickening of the prepatellar or superficial infrapatellar bursa, compared to 7% among painters.

Pes anserinus bursitis

The pes anserinus consists of the tendons of the sartorius, semimembranous and gracilis muscles at the inner aspect of the knee joint. Under the insertion point of these tendons, there is a bursa that can be inflamed. Pain is increased by forceful extension of the knee.

Trochanter bursitis

The hip has many bursae that surround it. The trochanteric bursa lies between the tendon of the gluteus maximus muscle and the posterolateral prominence of the greater trochanter (the other side of the hip). Pain in this area is usually called trochanter bursitis. Sometimes it is a true bursitis. The pain can radiate down the thigh and may simulate sciatic pain.

Theoretically it is possible that a special occupational posture can cause the disorder, but there are no scientific investigations.

Meralgia paresthetica

Meralgia paresthetica belongs to the entrapment disorders, and the cause is probably an entrapment of the nervus cutaneus femoris lateralis where the nerve comes out between muscles and fasciae above the edge of the pelvis (spina iliaca anterior superior). The sufferer will have pain along the front and lateral side of the thigh. The disorder can be rather tricky to cure. Different remedies, from pain killers to surgery, have been used with varying success. Since there are occupational exposures which cause pressure against the nerve, so this condition may be an occupational disorder. Anecdotal accounts of this exist, but there are no epidemiological investigations available that verify it.

Back

In general, pain is the main symptom of disorders of the leg, ankle and foot. It often follows exercise and may be aggravated by exercise. Muscle weakness, neurological deficiency, problems with fitting shoes, instability or stiffness of joints, and difficulties in walking and running are common problems in these disorders.

The causes of problems are usually multifactorial, but most often they arise from biomechanical factors, infections and/or systemic diseases. Foot, knee and leg deformities, bone and/or soft-tissue changes that follow an injury, excessive stress such as repetitive use, instability or stiffness and improper shoes are common causes of these symptoms. Infections may occur in the bony or soft tissues. Diabetes, rheumatic diseases, psoriasis, gout and blood circulation disturbances often lead to such symptoms in the lower limb.

Besides the history, a proper clinical examination is always necessary. Deformities, function disturbances, the blood circulation and the neurological state should be carefully examined. Analysis of gait may be indicated. Plain radiographs, CT, MRI, sonography, ENMG, vascular imaging and blood tests may contribute to the pathological and aetiological diagnosis and treatment.

Principles of treatment . The treatment should always be directed towards eliminating the cause. Except in traumas, the main treatment is usually conservative. The deformity will be, if possible, corrected by proper shoes and/or orthosis. Good ergonomic advice, including correction of wrong walking and running behaviour, is often beneficial. Diminishing of excessive loading, physiotherapy, anti-inflammatory drugs and in rare cases a short immobilization may be indicated. Redesign of work may be indicated.

Surgery may also be recommended in some acute traumas, especially for some persistent symptoms which have not benefited from conservative therapy, but specific medical advice is needed for each case.

Achilles Tendinitis

The disorder is usually due to overuse of the Achilles tendon, which is the strongest tendon in the human organism and is found in the lower leg/ankle. The tendon is exposed to excessive loading, especially in sports, resulting in pathological inflammatory and degenerative changes in the tendon and its surrounding tissues, bursae and paratenon. In severe cases a complete rupture may follow. Predisposing factors are improper shoes, malalignment and deformities of the foot, weakness or stiffness of the calf muscles, running on hard and uneven surfaces and intensive training. Achilles tendinitis occasionally occurs in some rheumatic diseases, after fractures of the crus or foot, in some metabolic diseases and following renal transplantation.

Pain and swelling in the region of the calcaneal tendon, the Achilles tendon, are rather common symptoms, especially in sportsmen. The pain is located in the tendon or its attachment to the calcaneum.

More men than women develop Achilles tendinitis. The symptoms are more frequent in recreational sports than in professional athletics. Running and jumping sports may especially lead to Achilles tendinitis.

The tendon is tender, often nodular, with swelling, and the tendon is fibrotic. Microruptures may be present. A clinical examination can be supported mainly by MRI and ultrasonography (US). MRI and US are superior to CT for demonstration of the region and quality of the soft-tissue changes.

Proper shoes in misalignment, orthotics, and advice in correct biomechanical training may prevent the development of Achilles tendinitis. When symptoms are present a conservative treatment is often successful: prevention of excessive training, proper shoes with heal lifts and shock absorption, physiotherapy, anti-inflammatory drugs, stretching and strengthening of the calf muscles.

Calcaneal Bursitis

Pain behind the heel, usually aggravated by walking, is often caused by a calcaneal bursitis, which frequently is associated with Achilles tendinitis. The disorder may be found in both heels and can occur at any age. In children, calcaneal bursitis is often combined with an exostosis or osteochondritis of the calcaneum.

In most cases improper footwear with narrow and hard back of the shoe is the cause of this disorder. In athletics excessive loading of the heel region, as in running, may provoke Achilles tendinitis and retrocalcaneal bursitis. A deformity of the back of the foot is a predisposing factor. There is usually no infection involved.

Upon examination, the tender heel is thickened and the skin may be red. There is often an inward bending of the hind part of the foot. Especially for differential diagnosis, radiographs are important and may reveal changes in the calcaneum (e.g., Sever’s disease, osteochondral fractures, osteophytes, bone tumours and osteitis). In most cases the history and the clinical examination will be supported by MRI or sonography. A retrocalcaneal bursogram can provide further insight into chronic cases.

The symptoms may subside without any treatment. In mild cases conservative treatment is usually successful. The painful heel should be protected with strapping and proper shoes with soft backs. An orthosis correcting the wrong position of the hind part of the foot may be valuable. A correction of the walking and running behaviour is often successful.

Surgical excision of the bursa and the impinging part of the calcaneum is indicated only when conservative treatment has failed.

Morton’s Metatarsalgia

Metatarsalgia is pain in the forefoot. It may be due to a neuroma of the plantar digital nerve, Morton’s neuroma. The typical pain is in the forefoot, usually radiating in the third and fourth toes, rarely in the second and third toes. The pain occurs on standing or walking at any age but is most frequent in middle-aged women. At rest the pain disappears.

The condition is often connected with flat forefoot and callosities. Compression of the metatarsal heads from side to side and of the space between the metatarsal heads may elicit pain. In plain radiographs the neuroma is not seen but other changes (e.g., bony deformities causing metatarsalgia) may be visible. MRI may reveal the neuroma.

Conservative treatment—proper shoes and pads—to support the anterior arch is often successful.

Tarsal Tunnel Syndrome

Burning pain along the sole of the foot and in all toes which may be due to compression of the posterior tibial nerve within the fibro-osseous tunnel under the flexor retinacle of the ankle, are all symptoms of tarsal tunnel syndrome. There are many conditions leading to compression of the nerve. The most common causes are bone irregularities, ankle fractures or dislocations, local ganglia or tumours, or bad footwear.

There may be loss of feeling in the areas where the medial and lateral plantar nerves lie, weakness and paralysis of foot muscles, especially the toe flexors, a positive Tinel’s sign and tenderness in the region of the nerve course.

A proper clinical examination of the function and the neurological and vascular state is essential. The syndrome may also be diagnosed by electrophysiological tests.

Compartment Syndromes of the Lower Limb

A compartmental syndrome is a result of prolonged high pressure of a closed intrafascial muscle space leading to markedly reduced blood circulation in the tissues. The high intracompartmental pressure is usually due to trauma (crush injuries, fractures and dislocations), but it will also result from overuse, from tumours and from infections. A tight cast may lead to a compartmental syndrome, as may diabetes and blood vessel disorders. The first symptoms are tense swelling, pain and curtailment of function which are not relieved when the leg is elevated, immobilized or treated with common drugs. Later on there will be paresthesia, numbness and paresis. In growing persons, a compartment syndrome may result in growth disturbances and deformities in the affected region.

If a compartment syndrome is suspected, a good clinical examination should be performed including that of the vascular, the neurological and the muscular state, the active and passive mobility of the joint and so on. Measurement of the pressure by multi-stick catheterization of the compartments should be performed. MRI, Doppler investigation and sonography may be helpful in the diagnosis.

Foot and Ankle Region Tenosynovitises

Of many symptoms in the foot, pain following tenosynovitis is rather common, especially in the ankle region and the longitudinal arch. The cause of the synovitis may be deformities of the foot, such as planovalgus, excessive stress, improper shoe fit, or sequelae to fractures and other injuries, rheumatological disorders, diabetes, psoriasis and gout. Synovitis may occur in many tendons, but the Achilles tendon is most often affected. Only rarely does tendinitis involve infection. A medical history and clinical examination are essential in the diagnosis of synovitis. Local pain, tenderness and painful movement are the main symptoms. Plain radiographs that show the bone changes and MRI, especially for changes in the soft tissues, are needed.

Ergonomic advice is needed. Proper shoes, correction of the walking and running habits and prevention of excessive stress situations on the job are usually beneficial. A short period of rest, immobilization in a cast and anti-inflammatory drugs are often indicated.

Hallux Valgus

Hallux valgus consists of extreme deviation of the first joint of the great toe towards the midline of the foot. It is often associated with other foot disorders (varus of the first metatarsal; flat foot, pes planotransversus or planovalgus). Hallux valgus may occur at any age, and it is seen more commonly in women than in men. The condition is in most cases familial, and it is often due to the wearing of improperly fitted shoes, such as ones with high heels and narrow pointed toe boxes.

The metatarsal joint is prominent, the first metatarsal head is enlarged, and there may be a (often inflamed) bursa bunion over the medial aspect of the joint in this condition. The great toe frequently overrides the second toe. The soft tissues of the toe are often changed due to the deformity. The range of extension and flexion of the metatarsophalangeal joint is usually normal, but it may be stiff due to osteoarthritis (hallux rigidus). In the vast majority of cases the hallux valgus is painless and requires no treatment. In some cases, however, hallux valgus causes shoe fitting problems and pain.

The treatment should be individualized according to the age of the patient, the degree of the deformity and the symptoms. Especially with adolescents and cases with mild symptoms, conservative treatment is recommended—proper shoes, insoles, pads to protect the bunion and so on.

Surgery is reserved especially for adult patients with severe shoe-fitting problems and pain, whose symptoms are not relieved by conservative treatment. The surgical procedures are not always successful, and therefore mere cosmetic factors should not be a real indication for surgery; but there is a great range of opinions regarding the usefulness of the approximately 150 different surgical procedures for hallux valgus.

Fascitis Plantaris

The sufferer feels pain under the heel, especially on long standing and walking. The pain radiates frequently to the sole of the foot. Plantar fascitis may occur at any age, but it is most frequent in middle-aged persons. The patients are often obese. It is also a rather common disorder in people who engage in sports. Often the foot has a flattened longitudinal arch.

There is local tenderness especially beneath the calcaneum at the attachment of the plantar fascia. All the fascia may be tender. On x ray a bony spur is seen in the calcaneum in about 50% of the patients, but it is also present in 10 to 15% of symptomless feet.

The causes of fascitis plantaris are not always clear. An infection, particularly gonorrhaea, rheumatoid arthritis and gout may cause the symptoms. Most frequently no specific diseases are connected to the condition. Increased pressure and tension of the fascia may be the main cause of the tenderness. The calcaneal spur may be a result of overusing of the fascia plantaris. It is probably not the primary cause of the calcaneal tenderness, because so many patients with those symptoms have no calcaneal spur and many with calcaneal spur are symptomless.

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Primary Fibromyalgia

The cause of fibromyalgia is not known. Some patients associate trauma and infections with the development of symptoms, but there is no hard evidence in favour of such triggering events. However, many factors are known to aggravate the existing symptoms. Cold, damp weather, mental disturbance, physical or mental stress, and also physical inactivity have all been associated with fibromyalgia (Wolfe 1986).

A major feature is patients waking up in the morning feeling tired. Abnormal serotonin metabolism is associated with both the sleep disturbance and decreased pain threshold typical in these patients (Goldberg 1987).

The symptoms of fibromyalgia start insidiously with persisting widespread musculoskeletal pains, multiple general symptoms such as fatigue, stiffness, subjective swelling of the fingers not observed by the examining physician, non-refreshing sleep and muscular pain after exertion. About one-third of the patients have additional symptoms, such as irritable bowel syndrome, tension headaches, premenstrual syndrome, numbness and tingling in the extremities, dryness of mouth and eyes and constriction of the blood vessels in the fingers when exposed to cold (Raynaud’s phenomenon).

Typically, a patient with fibromyalgia has a large variety of symptoms, which, with the exception of tender points, have no objective counterparts. Fibromyalgia runs a chronic course. Most of the patients continue to have symptoms with varying intensity. Complete remission is an exception. In primary fibromyalgia, no laboratory signs referring to inflammatory arthritis are present. Patients with inflammatory arthritis (e.g. rheumatoid arthritis) can also have fibromyalgic symptoms, in which case the term secondary fibromyalgia is applied.

There is no one test for fibromyalgia. The diagnosis of fibro- myalgia is based on the history of the patient and on the clinical observation of tender points (figure 1). The prevalence of fibro-myalgia in the general population is 0.5 to 1%. Most (75 to 90%) of the patients are women, usually between 25 and 45 years of age; children are rarely affected.

Figure 1. Tender point sites in fibromyalgia.

The American College of Rheumatology has set criteria for the classification of fibromyalgia (figure 2).

Figure 2. The American College of Rheumatology 1990 criteria for the diagnosis of fibromyalgia.

Diagnosis

Other ailments with similar symptoms must be excluded. Widespread pain must be present for at least three months. In addition there must be pain in 11 of the 18 tender point sites shown in figure 1 when pressed by an examiner’s finger.

Rheumatoid Arthritis

About 1% of the adult population has rheumatoid arthritis. The onset of the disease is usually at 30 to 50 years of age, with females having a threefold higher risk than males. The prevalence of the disease increases in older populations.

The cause of rheumatoid arthritis is not known. It is not inherited, but genetic factors increase the risk for the development of the disease. In addition to one or multiple genetic factors, some environmental triggering factors are thought to play a role in its pathogenesis, and viral or bacterial infections are heavily suspected.

Rheumatoid arthritis usually starts gradually. Typically, the patient has mild swelling of the small joints of fingers, and tenderness of the feet that manifests in a symmetrical fashion. If joints on one hand, for example, are involved it is likely that the same joints on the other hand will be affected. Stiffness of hands and feet in the morning is a major symptom. The patient often has fatigue and can have mild fever. Laboratory features include evidence of inflammation (elevated erythrocyte sedimentation rate and C-reactive protein level) and often mild anaemia. About 70% of the patients have circulating rheumatoid factor (autoantibody against IgG-class immunoglobulin). In early cases, radiological examination of hands and feet is often normal, but later on, most patients develop radiological evidence of joint destruction (erosions). The diagnosis of rheumatoid arthritis is based on a mixture of clinical, laboratory and radiological findings (see figure 3).

Figure 3. Criteris for the diagnosis of rheumatoid arthritis.

The diseases which most often cause differential diagnostic problems are degenerative joint diseases of the hands, arthritis following infections, spondylarthropathies, and some rare connective tissue diseases (Guidelines 1992).

Patient education to diminish the work-load of the joints, use of ergonomic appliances, good footwear, and proper treatment of infections form the basis of preventive measures. Treatment guidelines are given in table 1.

Table 1. Guidelines for the treatment of rheumatoid arthritis

Spondylarthropathies

Epidemiology and aetiology

Spondylarthropathies include typical clinical entities such as ankylosing spondylitis and some forms of arthritides associated with psoriasis, with chronic inflammatory bowel diseases, or with bacterial infections in the urogenital tract or in the gut (so called reactive arthritis). The diseases are common. The prevalence of the most chronic form, ankylosing spondylitis, in Western populations varies between 0.1 and 1.8% (Gran and Husby 1993). Three new cases of transient arthritis such as reactive arthritis compared to one patient with ankylosing spondylitis are estimated to occur annually in a population of 10,000. Most of the patients who develop spondylarthropathy are young adults, between 20 and 40 years of age. There is evidence that the mean onset of symptoms for patients with ankylosing spondylitis is increasing (Calin et al. 1988).

Spondylarthropathies have a strong genetic component since a majority of the patients have an inherited genetic marker, HLA-B27. The frequency of this marker is about 7 to 15% in Western populations; 90 to 100% of patients with ankylosing spondylitis and 70 to 90% of patients with reactive arthritis are HLA-B27 positive. However, at population levels, most of the subjects with this marker are healthy. Therefore, it is thought that exogenous factors, in addition to the genetic susceptibility, are needed for the development of the disease. Such triggering factors include bacterial infections in the urogenital tract or in the gut (table 2) skin lesions, and chronic inflammatory bowel diseases. The evidence in favour of infections is most direct in the case of reactive arthritis. Salmonella infections are widely increasing, as a sequel of which an increase in the cases with joint complications can be expected. Agriculture and poultry can be the sources of these infections. As to yersinia infections, pigs harbour yersinia bacteria in their tonsils. Slaughtering followed by storage of the meat products in the cold has been suggested to contribute to the dispersion of infections in humans. In patients with ankylosing spondylitis, however, usually no preceding infections can be traced as an initiating event. Recent results have, however, focused on the finding that patients with ankylosing spondylitis often have asymptomatic chronic gut inflammation, which could serve as a triggering factor or as a contributing inflammatory focus in the chronicity of the disease.

Table 2. Infections known to trigger reactive arthritis

Signs and symptoms

Peripheral arthritis is asymmetric, affects large joints, and has a predilection to low extremities. The patients often also have inflammatory low back pain, worse by night and relieved by movement, not by rest. A typical feature is a tendency to inflammation of the junction between tendons and bones (enthesopathy), which can manifest itself as pain under the heel or in calcaneus at the insertion of Achilles tendon. In addition to inflammation in the joints and at ligamentous insertions, patients also can have inflammatory symptoms in eyes (iritis or conjunctivitis), skin (psoriasis, skin lesions in palms, soles, or leg induration) and sometimes in the heart.

The following are the diagnostic criteria for spondylarthro- pathy (Dougados et al. 1991).

Inflammatory low back pain

or

Joint inflammation (synovitis):

• asymmetric
• predilection to low extremities

and

at least one of the following:

• positive family history for spondylarthropathy
• psoriasis
• inflammatory bowel disease
• buttock pain changing from side to side
• pain at the junction between tendon and bone (enthesopathy).

Patients with ankylosing spondylitis have low-back pain, worse by night, and tenderness between the spine and the pelvis at the sacroiliac joints. They can have limited mobility of the spine with chest tenderness. A third of the patients have peripheral arthritis and enthesopathy. The cornerstone of the diagnosis of ankylosing spondylitis is the presence of radiological changes in the sacroiliac joints; there is a loss of space between the joints, and bony outgrowths. Such changes add to the diagnostic accuracy of patients with spondylarthropathy but are necessary only in the case of ankylosing spondylitis.

Gout

Epidemiology and aetiology

Gout is a metabolic disorder that is the most common cause of inflammatory arthritis in men. Its prevalence among adults varies from 0.2 to 0.3 per 1000, and is 1.5% in adult males. The prevalence of gout increases with age and with increasing serum urate levels.

Hyperuricemia (high level of uric acid in serum) is a risk factor. Contributing factors are chronic kidney diseases which lead to renal insufficiency, hypertension, use of diuretic drugs, high alcohol intake, lead exposure and obesity. Gouty attacks are precipitated by hypersaturation of joint fluid with uric acid; the precipitated crystals irritate the joint, with the development of acute arthritis.

Signs and symptoms

The natural course of gout runs through several stages from a- symptomatic hyperuricemia to acute gouty arthritis, asymptomatic periods, and to chronic tophaceous gout (gout with nodules).

Acute gouty arthritis often manifests itself as an acute inflammation in one joint, usually at the base of the big toe. The joint is very tender, swollen and highly painful; it is often red. The acute attack can subside spontaneously within days. If untreated, repeated attacks can occur, and in some patients these continue (during the subsequent years) so that the patient develops chronic arthritis. In these patients, urate deposits can be observed in the ear helices, at the elbows, or at the Achilles tendons, where they form non-tender subcutaneous palpable masses (tophi).

Infectious Arthritis

Epidemiology and aetiology

In children, infectious arthritis often develops in a previously healthy child, but adults often have some predisposing factor, such as diabetes, chronic arthritis, use of glucocorticosteroid or immunosuppressive therapy, previous injections or trauma in the joint. Patients with endoprosthesis are also susceptible to infections in the operated joint.

Bacteria are most often the cause of infectious arthritis. In immunosuppressed patients, fungi can be found. Although bacterial infection in the joint is rare, it is very important to recognize, because, if untreated, the infection rapidly destroys the joint. The microbes can reach the joint by circulation (septic infection), by direct penetrating wound or during a joint injection, or from an adjacent infectious focus.

Signs and symptoms

In a typical case, a patient has acute joint inflammation, usually in one single joint, which is painful, hot, red and tender to movement. There are general symptoms of infection (fever, chills) and laboratory evidence of acute inflammation. The joint aspiration is turbid, and in microscopic examination a high number of white blood cells are seen, with positive stain and cultures for bacteria. The patient can have signs of a focus of infection elsewhere, such as pneumonia.

Osteoporosis

Epidemiology and aetiology

Bone mass increases from childhood until adolescence. Women gain 15% less bone density than men. It is at its highest between 20 and 40 years, after which there is a constant decrease. Osteoporosis is a condition in which bone mass decreases and bones become susceptible to fracture. Osteoporosis is a major cause of morbidity in the elderly. The most important manifestation is lumbar and hip fractures. About 40% of women who have reached 70 years have suffered from fractures.

Peak bone mass is influenced by genetic factors. In women, bone mass decreases after menopause. The decrease of bone mass in men is less distinct than in women. In addition to lack of oestrogen, other factors influence the rate of bone loss and the development of osteoporosis. These include physical inactivity, low amount of calcium in the diet, smoking, coffee consumption and low body weight. Use of systemic corticosteroid therapy is also associated with enhanced risk for osteoporosis.

Signs and symptoms

Osteoporosis can be asymptomatic. On the other hand, the most distinct manifestation of osteoporosis is bone fracture, typically that of the hip, vertebrae (spine) and wrist. Hip and wrist fractures usually are a result of falling, but vertebral fractures can develop insidiously after a trivial trauma. The patient has back pain, kyphosis and loss of height.

Bone Cancer

Epidemiology and aetiology

Primary malignant bone tumours are uncommon. They occur most often in children and young adults. Osteosarcoma is the most frequent of the malignant bone tumours. It is most frequently observed in the second decade of life, and in older adults it can result secondary to a bone disease (Paget’s disease). Ewing’s sarcoma is also mostly observed in children, who present with destructive changes in the pelvis or in the long bones. Malignant tumours originating from the cartilage (chondrosarcoma) can occur in many cartilage areas. In adults, malignant bone lesions are often metastatic (i.e., the primary malignant disease is somewhere else in the body).

Most malignant primary tumours have no known aetiology. However, Paget’s disease of bone, osteomyelitis, osteonecrosis and radiation injury have been associated with malignant transformation. Bone metastases are frequent in primary cancers of the breast, lung, prostate, kidney or thyroid gland.

Signs and symptoms

Pain, limitation of movement and swelling are present in patients with osteosarcoma. In addition to bone pain, patients with Ewing’s sarcoma often have systemic symptoms such as fever, malaise and chills. Chondrosarcomas can cause varying symptoms depending on the site of the tumour and its histologic details.

Osteomyelitis

Epidemiology and aetiology

Osteomyelitis is a bone infection that is usually bacterial, but can be fungal or viral. In an otherwise healthy person, osteomyelitis is a rare event, but in patients with chronic diseases such as diabetes or rheumatoid arthritis, infection in the body can spread by the bloodstream or by direct invasion to bones. In children, the most favoured site for the spreading is the shaft of long bone, but in adults the infection is often in the spine. A focal point from which an infection can spread by bloodstream or by direct invasion, penetrating or blunt trauma, prior orthopaedic surgery (insertion of prosthesis) can all be complicated by osteomyelitis.

Signs and symptoms

Acute bone infection of the long bones is associated with fever, chills and bone pain. Spinal osteomyelitis can cause more vague symptoms with progressive pain and low-grade fever. Infections around a prosthesis cause pain and tenderness when moving the operated joint.

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