Background

TRAUMATIC INJURIES, IN THE CONTEXT OF musculoskeletal medicine, can be classified as being either acute or chronic. Acute trauma entails a single, sudden traumatic event, whereas chronic trauma pertains to a series of traumatic events stemming from overuse of a certain joint or muscle group. Soft tissue injury resulting from acute trauma implicates many different supporting structures of the musculoskeletal system, which may include muscle, ligament, tendon, cartilage, or even fascia.

Epidemiology

Acute muscle trauma has been reported as the most common injury in athletes, with contusions and strain injuries accounting for about 90% of sports-related injuries.¹ Internal joint derangement and joint dislocations are also common injuries to soft tissue resulting from acute trauma. At the knee, injury to the anterior cruciate ligament (ACL) is estimated to have an annual incidence of about 1 in 3,500 people.² Shoulder dislocations have an estimated incidence rate of 23.9 per 100,000 person-years, with about 49% of the injuries occurring during a sport or recreational activity.³

Physiology

Muscular contusions result from direct, blunt trauma to the muscle, which causes micro-hemorrhaging and swelling within the belly of the muscle.⁴ In more severe contusions there is an increased risk for hematoma formation.⁴ Complications from muscular contusions can include acute compartment syndrome, myositis ossificans, and myonecrosis, depending on the severity of the injury.⁵ Joint dislocations and derangement are injuries that commonly occur when a force is directed through the joint, causing failure of the supporting soft tissue structures. For example, the “unhappy triad” of the knee describes the frequently combined injuries to the medial collateral ligament (MCL), medial meniscus, and ACL.⁶

Diagnosis

Diagnosis of muscular contusion is usually made based on the history, usually insidious onset, and physical examination; however, imaging of the site may be warranted if the healing process fails to proceed as expected. Patients will commonly present with pain at the site of trauma, limiting their range of motion in the affected limb. Plain radiographs are helpful to rule out an underlying fracture but are not as effective as magnetic resonance imaging (MRI) in assessing injury to the soft tissue. Acute compartment syndrome should be suspected when the soft tissue is firm or hard to palpation on physical examination. Diagnosis of derangement at a joint is suspected with pain and joint laxity on exam but is confirmed with MRI. Diagnosis of dislocation is made based on physical exam and plain radiographs. Table 32–1 describes different imaging modalities for various injuries associated with acute trauma.

Management Options, Medication, Therapies/Interventions/Alternatives, and Conclusions

Treatment for muscular contusions is typically focused on conservative measures that include rest, ice, compression, and nonsteroidal anti-inflammatory drugs (NSAIDs) during the acute phase. In a study of West Point cadets, Ryan et al found contusions of the quadriceps muscle group are effectively treated with early immobilization of the hip and knee in flexed positions, followed with tolerable passive range of motion and re-strengthening.⁷ Suspicion for acute compartment syndrome should be emergently addressed with decompression methods, which may require surgical fasciotomy. Treatment of internal derangement consists of conservative measures that include rest, ice, compression, and elevation (“RICE” protocol). Depending on the severity of the injury, surgical options may be warranted for the high-grade sprains and complete tears. Eventual range-of-motion and strengthening exercises become an integral part of the patient’s rehabilitation and overall recovery. Joint dislocations are properly addressed with prompt, closed reduction of the joint in the absence of contraindications to the procedure. Surgical intervention is undertaken with complex dislocations and those that are irreducible. The joint is commonly immobilized for several weeks following successful reduction, with gradual introduction of range-of-motion exercises.⁸

Background

Chronic trauma, or cumulative trauma disorders (CTDs), is described as tissue damage to the nervous and/or musculoskeletal system that results from repetitive demand over the course of time.⁹ The term refers to a wide variety of diagnoses, including occupational, recreational, and habitual activities (Table 32–2).

Physiology

The pathophysiology of overuse injuries is based on the idea that cumulative biomechanical stresses can result in tissue alteration in tendons, ligaments, neural tissue, and other soft tissues over time.⁹ These stresses include shear, tension, compression, impingement, vibration, and contraction. Mechanical fatigue results in characteristic changes depending on the individual property of the tissue. In soft tissues, damage is marked by inflammation, collagen deposition, and tissue contraction, which can in turn lead to pain or loss of motion.¹⁰

Epidemiology

The incidence of overuse injuries as a whole in the United States is nearly impossible to estimate, given the sheer volume of included diagnoses, as well as the difficulty in establishing clear diagnostic criteria.¹¹ Several diagnoses are due to cumulative trauma, with the most common being low back pain (LBP), carpal tunnel syndrome, and neck/shoulder pain.⁹

Diagnosis

Diagnosis of these conditions is typically made primarily based upon clinical history and exam, with supportive studies such as imaging or electrodiagnosis used in equivocal cases. Hallmark symptoms may include a history of popping, clicking, rubbing, erythema, or vascular phenomena.¹²

Management Options, Medication, Therapies/Interventions/Alternatives, and Conclusions

Management begins with relative rest and workplace modification, including ergonomic interventions. Conservative treatments include NSAIDs, therapeutic heat/cold, and physiotherapy consisting of stretching and strengthening of relevant muscle groups. Other modalities such as myofascial release, deep friction massage, transcutaneous electrical nerve stimulation (TENS), acupuncture, ultrasound, and iontophoresis are well described in the literature. Steroid injections can be utilized in some conditions when these treatments fail. Finally, surgery can be performed in refractory cases.⁹

Background/Physiology

Spinal disorders encompass a broad range of pain syndromes and injuries that commonly involve the vertebrae, the joints of the spine, and the intervertebral discs. Please see Chapter 35 for further details.

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  Vertebrae – Defects in the architecture of the vertebrae tend to occur most frequently at the vertebral body and the pars interarticularis. At the vertebral body, compression fractures result in wedge-shaped deformities and have been reported as the most common osteoporotic fracture.¹³ Fractures of the pars interarticularis are referred to as spondylolysis, whereas spondylolisthesis refers to displacement of one vertebral segment over another as a result of bilateral defects in the pars interarticularis. Scoliosis is another spine disorder that involves the vertebral segments, which is characterized by the misalignment of vertebrae in the coronal plane, causing an abnormal lateral curvature in the spine with associated rotation of the vertebral segments.

  
  
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  Joints – Of the various joints in the spine, the two most common culprits for spinal disorders are the zygapophyseal and sacroiliac (SI) joints. Zygapophyseal joints, or Z-joints, are classified as true synovial joints with articulation and can become subjected to arthritic, degenerative changes. The term “facet syndrome” has been used to refer to the degeneration at the Z-joints, which may lead to hypertrophy of the joints and cause referral pain patterns in the back.¹⁴ Similarly, the SI joint is also a diarthrodial joint susceptible to degenerative changes.

  
  
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  Discs – Intervertebral discs are composed of a centralized nucleus pulposus and the outer annulus fibrosus. The discs are susceptible to several types of injury, which can include general degenerative changes, disc herniation, or disc disruption.

Epidemiology

According to the National Ambulatory Medical Care Survey, about 3% of the diagnoses made in the outpatient setting involve spinal disorders.¹⁵ The financial burden of low back pain alone in the United States has been reported at over $100 billion per year, with a lifetime prevalence of about 14%.^16,17 Similarly, neck pain has been reported as having an annual prevalence rate of over 30%.¹⁸

Diagnosis

Spondylosis is best evaluated using oblique x-rays of the spine, with visualization of the “Scotty dog” view.¹⁹ Plain x-rays of the spine can assess for spondylolisthesis and scoliosis, with flexion and extension views demonstrating possible instability at the segments¹⁹ (Fig. 32–1). The Cobb angle configured on the lateral standing x-ray view assesses the severity of scoliosis (Fig. 32–2). Physical exam and imaging have not been shown to consistently and accurately diagnose pain syndromes generated from the Z or SI joints.^20,21 Imaging of the spine may reveal degenerative changes or hypertrophy at the respective joints. Diagnosis of disc disease is commonly made on MRI of the spine. Electromyography and nerve conduction studies are beneficial in assessing nerve involvement and prognosis.

Management Options, Medication, Therapies/Interventions/Alternatives, and Conclusions

Treatment for both spondylosis and spondylolisthesis is generally conservative with the option of bracing but may require surgery for higher, more severe, grades of spondylolisthesis accompanied with neurologic decline. Bracing has been found to be beneficial for patients with scoliosis that have a Cobb angle between 20 and 39 degrees.²² Surgery is generally reserved for patients with a Cobb angle greater than 40 degrees to help prevent the progression of the curve. Treatment for degenerative joint disease of the spine tends to be conservative, relying heavily on a rehabilitation program using lumbar stabilization techniques. Fluoroscopically guided pain interventions (radiofrequency ablation of the medial branch nerves or intra-articular facet steroid injections) may be useful in both the diagnosis and management of facet pain syndromes. Management of disc disease is dependent on the specific type and severity. First-line treatment consists of conservative methods with rehabilitation and oral medications for pain control. Epidural steroid injections may be indicated if conservative treatment fails. In more severe persistent cases, surgical intervention may be warranted. Table 32–3 describes several common spinal disorders and treatments.²²

Background/Physiology

Osteoporosis is a metabolic bone disease that is characterized by a low bone mass that results from an imbalance in bone remodeling. Risk factors for osteoporosis can be divided between modifiable and nonmodifiable risk factors. Nonmodifiable risk factors include advanced age, family history, white race, endocrine abnormalities, and female gender. Modifiable risk factors include smoking, excessive alcohol intake, malnutrition, inactivity, and low body mass index (BMI). Although the pathogenesis of osteoporosis is a complex process that includes many factors, the end result is bone loss at an increased rate compared to healthy individuals. The mechanism for bone remodeling is based primarily on the activity of osteoclasts and osteoblasts, which regulate bone resorption and formation, respectively. An imbalance in the coupling between the two processes results in an increased rate of bone breakdown, leading to a reduction in bone mass.

Epidemiology

Osteoporosis is a condition that most commonly affects postmenopausal women, affecting about 10% of women in the United States over the age of 50, compared to 2% of men for the same age population.²³ In 2010, an estimated 306,000 hospital visits contained hip fracture as the first listed diagnosis, with an average length of stay of 5.8 days.²³

Diagnosis

Fracture is oftentimes the first presenting symptom of osteoporosis lacking preceding clinical evidence. Screening measures therefore should be implemented at the age of 65 in women and 70 in men, regardless of risk factors.^24,25 Dual energy x-ray absorptiometry (DEXA) is currently the gold standard for screening and diagnosis of osteoporosis through quantification of bone mineral density.²⁶ The diagnosis of osteoporosis is based on a T-score less than −2.5 on DEXA scan, which represents 2.5 standard deviations below a young, healthy adult. Osteopenia is defined as a T-score between −1 and −2.5, and normal bone density includes T-scores between −1 and +1 (Fig. 32–3).

Management Options, Medication, Therapies/Interventions/Alternatives, and Conclusions

There is a steep increase in fracture risk with T-scores -2.0; the risk is heavily influenced by age (Fig. 32–4).

Treatment for osteoporosis includes dietary, pharmacologic, and lifestyle strategies. In patients with osteoporosis, adequate amounts of vitamin D and calcium are an essential component to the treatment plan. For women over the age of 50, the American Association of Clinical Endocrinologists (AACE) recommends 1200 mg of calcium per day.²⁷ In patients with established osteoporosis, the Institute of Medicine has recommended 800 IU of vitamin D daily.²⁸ Pharmacologic therapy of osteoporosis includes bisphosphonates, hormonal medications, and selective estrogen receptor modulators (SERMs). Bisphosphonates are a class of medications that inhibit osteoclast activity, and are considered first-line agents in the treatment of osteoporosis.²⁷ Hormones commonly used are estrogen and calcitonin, which help decrease bone resorption via inhibition of osteoclasts. Teriparatide, or Forteo, is a recombinant form of human parathyroid hormone that increases bone formation. Safe physical activity is another key factor in both the treatment and prevention of osteoporosis. Specifically, weight-bearing exercise and resistance training have been shown to preserve and improve bone mineral density in postmenopausal women (Fig. 32–5).²⁹

Background/Physiology

Tendinopathy is a term that is used to describe localized pain at the site of a tendon, commonly resulting from overuse. It is a syndrome that is characterized by thickening of the tendon and loss of mechanical properties, which is associated with pain.³⁰ Tendinitis has been commonly used to describe the acute, inflammatory state, although growing histological evidence does not support this notion.³¹