1.1 Orthopedic Pain Management

As such, it deals with the diseases and injuries found in bones, ligaments, muscles, and joints at every stage of life. Orthopedics is described more precisely in the German Medical Association’s specimen advanced training ordinance for orthopedic and trauma surgery specialists in the version dated June 25, 2010:

“Orthopedics and trauma surgery comprises the prevention, recognition, surgical and conservative treatment, follow-up care, and rehabilitation of injuries and their consequences, as well as congenital and acquired changes, malformations, functional disorders, and diseases of the musculoskeletal organs, taking age-related differences into account.”

“Spinal and joint injection and puncture techniques” are officially defined diagnostic and treatment methods in this area.

The spectrum of orthopedic medicine ranges from malformations of the spine and limbs to inflammatory bone and joint diseases, pediatric orthopedics, musculoskeletal oncology, rehabilitative medicine, and technical orthopedics. It also includes injuries and damage to the musculoskeletal organs caused by wear and tear, as well as the pain states associated with these injuries.

The essential components of conservative orthopedics include not only the treatment of pain but also recovery from musculoskeletal disorders that affect function and form. This includes the use of bandaging, physical agents and electrotherapy, manual therapy, systemic pharmaceutical therapy, local injections, physiotherapy, and orthopedic devices (Orthopädie Memorandum 1998).

The International Association for the Study of Pain has agreed on a more extensive definition of pain: “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage” (IASP 1986). This definition distinguishes pain from other unpleasant sensations by relating it to physical damage. The second part of the definition acknowledges that pain may be experienced even when no tissue damage can be demonstrated at that instant. This extension of the definition is especially important for pain that is described as chronic.

Further sensory disorders within the musculoskeletal system that possess possible warning functions include the following disorders based on the definitions of Merskey and Bogduk (1994):

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  Hypoesthesia: reduced sensation to touch.

  
  
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  Anesthesia: loss of sensation.

  
  
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  Anesthesia dolorosa: pain in a numb area.

  
  
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  Paresthesia: abnormal sensation that is either spontaneous or provoked; described as being like ants crawling, pins and needles, or a furry feeling.

  
  
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  Dysesthesia: in contrast to paresthesia, the abnormal spontaneous or provoked sensation is distinctly unpleasant.

  
  
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  Hyperesthesia: increased sensitivity to touch stimuli.

  
  
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  Hyperalgesia: increased sensitivity to pain.

  
  
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  Allodynia: pain that results from a stimulus that is not normally painful.

These sensory disturbances occur in the musculoskeletal system with or without pain, e.g., with nerve root syndromes, with peripheral nerve lesions, and in the area surrounding surgical wounds. Neuropathic pain can also occur here that is triggered by a primary lesion or nervous system dysfunction. Local numbness and sensory disorders often remain as residual symptoms after a subsided nerve compression. They can function as an alarm, e.g., saddle anesthesia caused by cauda equina syndrome.

Acute and chronic pain are not differentiated solely by the duration of the pain. Acute pain in the musculoskeletal system is felt following acute events, e.g., stretching of the joint capsule, muscle tears, or disk prolapse.

A chronic pain syndrome or pain chronification in the musculoskeletal system is described as pain that is constantly or intermittently present over a period of at least 3 months. The most common causes are relapsing spinal syndromes with or without radiation into the extremities. The progression from acute to chronic pain is fluid and is referred to as chronification.

Within the musculoskeletal system, the chronification of pain is defined as the transition from acute to chronic pain, where pain is present for more than 3 months and has lost its warning function. The patient exhibits an increase in secondary psychological symptoms, with a change in the perception and processing of pain signals. The relationship between the intensity of the pain stimuli (e.g., tissue damage) and the pain reaction is lost.

The degree of chronification is dependent on the following:

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  The duration of pain.

  
  
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  Pain dispersion.

  
  
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  Response to medication.

  
  
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  The doctor–patient relationship.

  
  
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  Changes in experience and behavior.

  
  
  
  

  Example

  
  

  Symptoms of lumboischialgia persist for several months during the chronification process. The radiating pain and the area of radiation into the leg change constantly. The patient requires stronger medication to deal with the pain, and ends up by changing doctors.

The pain chronification score proposed by Gerbershagen provides a valuable framework for pain classification (Gerbershagen 1986). The Graded Chronic Pain Scale (GCPS) developed by Von Korff records the pain intensity in the past 3 to 6 months using numeric rating scales from 0 (no pain) to 10 (worst imaginable pain). It records limitation of activities of daily living, leisure time, and work on a scale of 0 (no interference) to 10 (extreme interference) while quantitatively recording the “days in pain” (Von Korff et al 1992).

Concomitant symptoms, such as increased muscle tension, abnormal posture, and psychogenic reactions, become more important. These symptoms may even become a disease in their own right, even when the cause of pain is no longer present.

The impact of chronic pain on the patient is significant. In 2006, Tang and Crane demonstrated that for chronic pain patients the risk of death by suicide was more than twice that of patients with chronic emphysema, heart failure, or depression.

Treating chronic pain is highly significant in terms of health economics. According to a study by Eriksen et al (2003), pain is the reason for 20% of all doctor’s visits. Ten percent of the sales of drugs in industrialized countries involve pain medication. And the costs of treating pain amount to USD 1 trillion annually.

Chronic pain syndrome is also referred to as “pain disease” (e.g., Adler et al 1989; Eggle and Hoffmann 1993) to emphasize that it is the pain itself that has become a disease. One disadvantage of this terminology is that patients are given the impression that because they have a “disease” there is nothing they can do about the pain. It is exactly this interpretation that is detrimental in chronic pain syndrome. In fact, the opposite is true, and patients should be educated in how to actively manage their pain.

Orthopedists use a variety of methods to treat pain. Aside from the administration of common analgesics in general pain therapy, other methods specifically related to orthopedics include:

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  Physical therapy.

  
  
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  Physical agents and electrotherapy.

  
  
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  Manual therapy.

  
  
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  Local injections.

  
  
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  Orthopedic technical aids.

  
  
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  Exercise programs.

  
  
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  Surgery.

Following injury, orthopedic pain therapy is applied directly or indirectly to the somatic source of pain, and is intended to prevent the chronification of pain. The cascade of acute pain to chronic pain and subsequently to a chronic pain syndrome should be halted right from the start. When the initial intervention is unsuccessful, or too late, treatment must increasingly take psychological aspects into consideration. Psychosomatics, psychology, and orthopedics are of equal importance in the treatment of chronic pain, chronic pain syndromes, and somatic psychogenic disorders. Purely psychogenic disorders primarily require the input of a psychologist. At the same time, orthopedic surgeons must rule out primary organic disorders and keep a lookout for secondary functional disorders as required. Chronic pain also has a high socioeconomic relevance and also poses a challenge for the orthopedists in their function as experts (in disability-benefit cases).

1.2 Epidemiology

▶ Most common initial disease. The first serious illness of adulthood requiring medical attention generally affects the musculoskeletal system. This includes conditions such as herniated disk, sciatica, and injury-related sequelae, especially involving the knee and foot, as well as first-time symptoms of incipient osteoarthritis (Orthopädie Memorandum 1998).

In Germany, 1.3 million sports-related accidents requiring medical attention occur each year (Gläser and Henke 2014). Among these first-time orthopedic disorders, the spine and knee joint are most frequently involved. The average age of patients with these first-time disorders is 22.8 years (Ludwig et al 1998). The acute initial disorder often develops into chronic pain if the chronification process is not interrupted consequently.

Hospital and pension fund operators’ statistics demonstrate the economic significance of orthopedic disorders as manifested by the relative prevalence and constant increase in spinal and joint disorders, sports injuries, and cases of osteoarthritis and rheumatic diseases (Orthopädie Memorandum 1998).

The high prevalence of orthopedic ailments is also reflected in the statistics of days missed from work due to illness. In 2008, one-quarter of all days missed due to illness in Germany were caused by musculoskeletal disorders, one of the main causes, along with respiratory disorders and injuries/poisoning. The diagnosis of “dorsalgia” (ICD-10 M.54) is particularly relevant (SuGA 2008). The average age of patients with the highest number of days missed from work due to illness of the musculoskeletal system is 41 years.

According to the Statistical Yearbook published by the German Federal Statistical Office, painful orthopedic disorders are the most common reason for granting disability benefits and early retirement. The telephone health survey conducted by the Robert Koch Institute in 2004 on behalf of the German government showed a 12-month prevalence of back pain of more than 60% for both men and women, with women affected more frequently than men. According to the last large-scale health survey conducted in Germany in 1998, the annual incidence of back pain even among men under the age of 30 years is 55.4%, while it is 61.3% for women in the same age group. These figures remain constant into old age with only slight deviations (Fig. 1‑1).

Among the chronic pain disorders, degenerative spinal and joint disorders are not only the most frequent but also increasing at a disproportionate rate. As humans age, the resilience of their musculoskeletal organs decreases. This limits their capacity to walk and stand, culminating in decompensation leading to the need for a wheelchair or to being bedridden. Musculoskeletal pain disorders are contributory cause for activity limitation and the need for nursing care (Orthopädie Memorandum 1998).

Chronic musculoskeletal pain heads the list of disorders and disabilities recognized in Germany to determine the need for nursing care in accordance with the new long-term care insurance (Section 14 (2) of the Social Code).

▶ Prevalence of chronic pain. When patients with musculoskeletal problems first seek medical attention, are temporarily unable to work, or submit a premature application for a pension, chronic pain is often the motivating factor. Functional impairment, deformity, and impaired performance are secondary. When the spine is involved, the problem tends to be low back pain rather than a lack of flexibility. In patients with osteoarthritis of the hip, it is the pain rather than immobility that causes them to seek out a physician.

During our survey, 75.8% of the patients at orthopedic practices reported that they had consulted a physician primarily due to pain. A similar survey of patients at practices of other specialists showed that a much smaller percentage of the patients were primary pain patients (Krämer 1996).

The patient mix at outpatient pain clinics is similar (Hildebrandt 1993; Fig. 1‑2).

▶ The spine is the most frequently involved. Painful spinal syndrome affects nearly everyone at some point in their lives.

In early adulthood, this tends to be acute low back and/or shoulder and neck pain that persists for only a matter of days. In most cases, the patient does not consult a doctor or specialist immediately.

One out of three patients develops chronic recurrent pain that requires medical attention (Krämer 1997).

Only 0.25% of all patients with low back and leg pain caused by nerve root compression require surgery in the end (Frymoyer 1992).

The high percentage of spinal disorders in the statistics on disability, pension, hospital treatments, and treatment by physicians reimbursed by statutory insurance providers in Germany has also been reported in the literature (Berger-Schmitt et al 1996; Raspe 1993). In 2006, the cost of treating “dorsopathies” (ICD-10 M45-M54) was EUR 8.3 billion and has shown an increase in recent years (Statistisches Bundesamt 2008).

Statistical surveys conducted at general practitioners’ and orthopedists’ practices as well as at orthopedic outpatient clinics show that spinal pain syndrome is the leading complaint in all areas (Krämer 1997). According to the findings, 1 in 10 patients seeing a general practitioner presents for treatment of spinal pain syndrome. At orthopedic outpatient clinics, the ratio is 1:3, while at orthopedists’ private practices, one in two patients presents with spinal pain syndrome. Among the orthopedic complaints treated on an outpatient basis, spinal pain disorders play a dominant role, accounting for 37.8% of the complaints. Fig. 1‑3 shows the frequency with which the individual parts of the extremities are treated by orthopedic specialists.

Pain syndromes affect individual spinal segments to various extents. The most frequently involved segment is the lumbar spine, at 61.94%, ahead of the cervical spine, at 36.1%. Thoracic spine syndrome, manifesting as intercostal neuralgia, is rare, at only 1.96% (Fig. 1‑4). Men (47.2%) are affected by spinal syndromes almost as often as women (52.8%). Women (60.6%) are affected by cervical syndrome more often than men, while men (51.3%) are affected by lumbar syndrome slightly more often than women. Men are more frequently affected than women by severe lumbar syndrome with radicular deficits requiring hospitalization.

In terms of age, 68% of the patients are between 30 and 60 years, with prevalence peaking among patients between the ages of 40 and 50 years. The frequency and intensity of spinal pain syndrome increase from the age of 50 onwards (Krämer 1997).

Chronic pain involved with painful degenerative disorders affecting the joints of the extremities tends to begin between the ages of 50 and 60 years and then steadily increases thereafter.