Introduction

Osteoporosis is a skeletal disease characterized by decreased bone mass and alteration in bone structure, which increases fracture risk. The World Health Organization defines osteoporosis as bone mineral density (BMD) T score less than −2.5, and low bone mass as T score between −1.0 and −2.5. The prevalence for osteoporosis is estimated at approximately 11% for adults aged 50 years or older overall (16.5% prevalence in woman and 5.1% in men). The elderly population accounts for most of the disease burden, with 70% of all fractures sustained by those aged at least 65 years. The prevalence of osteoporosis is increasing as the number of elderly patients continues to increase. Cost of care for osteoporosis has increased more than 118% over 15 years, nearly $50 billion over more than a decade.

Risk Factors

The pathogenesis of osteoporosis is multimodal, involving various factors such as demographics, nutrition, social factors, genetics, and physical and hormonal changes. Table 1 summarizes the risk factors discussed in the following.

Demographics

Some nonmodifiable risk factors include older age, gender, ethnic background, and prior fractures. ^, The prevalence of osteoporosis in men older than 60 was 3 times higher than those aged 50 to 59. Certain populations have an increased rate of osteoporosis. Hispanic individuals have a higher rate of fracture at the spine, and Caucasian individuals have an increased rate at the femoral neck. ^,

Presentation

Osteoporosis is considered a “silent disease,” and is often missed in elderly individuals. Osteoporosis screening is therefore essential and recommended for women 65 years and older and women younger than 65 who are postmenopausal with risk factors. Screening includes yearly dual energy x-ray absorptiometry scans to measure BMD at the hip and lumbar spine. The National Osteoporosis Foundation guidelines recommend BMD measurement for women aged 65 and older and men aged 70 and older, regardless of risk factors. If risk factors are present, screening is recommended for younger postmenopausal women, women in menopausal transition, and men aged 50 to 59.

Fragility fracture refers to a break in the bone in a low-impact trauma setting that would typically not cause a fracture. As patients age, studies have found that osteoporotic women suffer more than 3 times more nonvertebral fractures than those with normal BMD. Most nonvertebral fractures are related to falls, whereas most vertebral compression fractures occur in the absence of a fall. Previous studies suggest that a fragility fracture occurs with increased load on the spine, and can even occur during trivial events such as sneezing or lying in bed. The most common locations of vertebral fractures are at the T12 and L2 segments, both which include transitions from rigid thoracic vertebrae to mobile lumbar vertebrae.

The classic description of a vertebral fragility fracture is an osteoporotic individual experiencing severe back pain while bending forward. Nevertheless, in an aging athlete, compression fracture can present similar to a muscle strain. This variation in presentation of spinal compression fractures can result in inaccuracy. Vertebral fractures are often the most common complication but remain undiagnosed because they are mostly asymptomatic. ^,

Often, the only symptom of vertebral compression fracture is low back pain. However, due to prolonged activity, there are increased risks of deep vein thrombosis and pulmonary embolism. Multiple vertebral fractures can cause fatigued muscles and pain, causing difficulty in maintaining posture. Continued loss of vertebral body height can eventually result in deformities such as thoracic kyphosis and lumbar lordosis, impairing gait and balance. In severe cases, vertebral fractures can impair pulmonary function and cause early satiety, weight loss, and morbidity and mortality. ^,

Assessment for Fracture Risk

One of the most commonly used algorithms to assess BMD and its risk factors for fracture risk is FRAX or a variation called DeFRA, which uses continuous variables and is considered to be more detailed. The risk factors for the World Health Organization Fracture Risk Assessment Model include age, gender, body mass index, prior osteoporotic fracture, femoral neck BMD, rheumatoid arthritis, secondary causes of osteoporosis, parental history of hip fracture, current smoking, alcohol intake, and oral glucocorticoids. ^,

Osteoporosis Prevention and Nonpharmacologic Management

Overview

Degenerative disk disease (DDD) refers to degeneration of the intervertebral disk characterized by disk dehydration, annular tear, and loss of disk height. Intervertebral disks are cartilaginous structures that lie between vertebral bodies connecting them. They consist of 2 rings, annulus fibrosis, a thick outer ring of fibrous cartilage, and the nucleus pulposus, a gelatinous core. ^, Disruption of these disks can cause herniation of the nucleus pulposus. DDD specifically refers to disk degeneration that causes pain and/or neurologic symptoms.

This is a common phenomenon in elderly individuals, as more than 90% of adults by the age of 60 will show a small amount of disk degeneration. A high number of elite athletes had significant spinal degeneration at the 2016 Olympics. Almost 52% showed severe spinal disease, with the highest level of degeneration indicating potential association with cyclic overloading speeding up cell death within cells. The most frequent site is the thoracolumbar junction due to flexion, extension, and rotation loads that increase disk strain and stress. Football, wrestling, hockey, dance, gymnastics, tennis, and golf are individual sports in which this injury mechanism commonly occurs, whereas runners were not affected by DDD.

Risk Factors

• a.
  

  Aging and genetics (most important)

  
  
• b.
  

  Excessive strain on the disk, such as sports, heavy lifting, and labor-intensive jobs; type of sport and intensity has shown acceleration of disk degeneration (75% of elite gymnasts show DDD)

  
  
• c.
  

  Sedentary lifestyle: prolonged sitting can strain the back and cause excessive gravitational load on the spine

  
  
• d.
  

  Trauma on the disk: surgery or fracture slowing blood supply

  
  
• e.
  

  Smoking

Presentation

The patient’s history, physical examination, and events before presentation of symptoms should be recounted. MRI should not be ordered unless red flags, such as cauda equina, infection, suspected tumor, or trauma (fall, collision), are present. Radiation of back pain associated with disk disease is thought to be due to the compression of nerve roots in the spinal canal from either disk herniation or hypertrophy of the degenerative tissues. The nucleus pulposus is resorbed over time. Other times, the ligamentum flavum and the facet joints can compromise the surrounding nerve roots. Acute sciatica often remains undiagnosed due to its increased variation in its presentation: people report only 8% acute sciatica after heavy lifting or physical trauma.

Diagnosis

The initial study of choice is an upright radiograph to rule out deformity, fractures, and neoplastic causes of low back pain. MRI is the more sensitive imaging modality to assess disk disease, like disk space narrowing, decreased signal intensity in the disk, and vertebral endplate changes. T2-weighted MRI can be used to assess for any compression of neurologic structures.

Management

Initial management includes physical therapy and the use of nonsteroidal anti-inflammatory drugs or epidural infections. Epidural injections may provide short-term relief but long-term relief has not been shown. ^, The nonconservative approach does not work for many people and discectomy is typically offered. According to the SPORT trial, patients electing for surgery had better outcomes both at 3 months and 4 years. Data are not available regarding elderly athletes, but younger athletes return 5 months after operation. Postoperative rehabilitation with intensive exercise programs showed considerable improvement and return to function than mild intensity programs. High-intensity programs were not associated with reherniation or reoperation. It is important to keep in mind that surgery is not a cure-all for disk degeneration and will not reverse the damage. Weight loss, an exercise program, and a healthy diet are essential, and positive changes in lifestyle have shown significant improvement in symptoms. Mature athletes must also be cognizant of their limitations. They might have to alter exercise and activity levels with the help of physical therapy to reduce pain in the lower back and stress on the disk.

Overview

Spinal stenosis is characterized as compression of the nerve roots and spinal cord, causing symptoms including pain, numbness, or weakness. There are 3 main mechanisms that spinal stenosis can affect the aging spine. First, narrowing of the central canal, which contains the spinal cord, can cause reduction of blood supply and compression of neural structures. Second, compression of the neural foramen, opening where nerve roots exit the spinal cord, can occur. Finally, the lateral recess in the lumbar spine, where the nerve root enters before it exits the neural foramen, can be compressed by facet joint hypertrophy.

The prevalence of spinal stenosis increases by age and is predicted to be 19.4% for people aged 60 to 69. Lumbar spinal surgery (LSS) remains the most common reason for the elderly to undergo spinal surgery and in 2009, the hospital costs for LSS was $1.6 billion.

There are limited studies analyzing the prevalence of spinal stenosis in athletes. As opposed to solely being caused by a degenerative process, lumbar stenosis in athletes can be caused by scoliosis, spondylolisthesis, or lumbar disk herniation. Athletes in contact sports, like football players, can experience neuropraxia with a severe hyperextension injury. This cohort was found to have an increased prevalence of cervical spine stenosis. Meanwhile, masters athletes do not typically participate in contact sports ; yet, weight-lifting and swimming competitions have been shown to involve extensive extension forces that could potentially cause symptomatic stenosis seen in contact sports.

Presentation

Pain in spinal stenosis often originates as lumbar pain that progressively worsens and causes numbness. Neurogenic claudication remains the most common symptom and can lead to positional pain and weakness that is worse while walking, but improves as one bends forward or sits. Symptoms are often more acute as the disease progresses.

Diagnosis

Lumbar MRI is the gold standard to visualize the greatest change associated with spinal stenosis. T1-weighted and T2-weighted images are obtained in sagittal and transverse planes. Radiographs may be useful to see degenerative changes; computed tomography (CT) scans help assess bone condition and diagnose osteoporosis. Other diagnostic evaluations to rule in or out other differentials include ankle brachial index, laboratory tests such as HbA1c, C-reactive protein, complete blood count, and further neurology workup if there is suspicion of polyneuropathy.

Management

According to Johnsson and colleagues, 70% of patients remain stable for a 4-year period, 15% improve, and 15% become worse. Pharmacologic management includes muscle relaxants and painkillers as required, but care must be taken when managing pain in elderly individuals. Opioids, such as gabapentin, must be balanced with cognitive side effects, but they have therapeutic effects associated with neurologic damage. Nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen have renal and hepatic side effects, respectively, and can predispose to gastric ulcers, so must be used with caution. Physiotherapy, including massage, exercises, and manipulation, pain management, and lifestyle modification are essential to recovery. Although existing reports suggest that exercise may lead to exacerbation of symptoms, exercise is important in conditioning and strengthening the back or lumbar muscles, avoiding weakening or further impairment. No evidence exists to suggest that one type of therapy is superior. Wearing braces such as corsets has shown no improvement. Stationary bikes have been well tolerated by athletes as they prepare to return from injury.

Epidural injections have been shown to reduce inflammation and provide pain relief. Epidural injections with anesthetic properties and steroids have shown no benefit compared with the anesthetic alone. ^, The procedure itself can be difficult to perform in adults with degenerative changes. In terms of long-term pain relief and function, epidural injections do not have an effect. ^,

Surgery is the ultimate option for management in patients who have severe limitations of function. In patients older than 65 who are undergoing spine surgery, lumbar spinal stenosis is the most common preoperative diagnosis. There are many procedural techniques and minimal guidelines on which treatment to use. Without spondylolisthesis, laminectomy and fusion were found to be superior to nonoperative approaches. Decompression with fusion leads to high intraoperative blood loss and does not improve postoperative complications compared with decompression alone. Recently, minimally invasive decompression procedures or surgeries have become more common and studies demonstrate an association with higher patient satisfaction with similar complication rates. Another minimally invasive technique that uses interspinous processes can reduce operative time, but has not shown much improvement to current standard, and in fact, has been associated with higher rates of reoperation. ^,

Prevention

Currently, athletes are cross-training and strengthening their muscles to maintain balance between lower extremity and trunk flexors and extensors. This can reduce the hyperextension loads that exacerbate the symptoms of lumbar stenosis. For example, weight lifters focus on full-body conditioning, flexibility, aerobic conditioning, speed, and cross-training. Although running solely does not predispose to lumbar stenosis, runners with risk factors or prior history can focus on improving flexibility and strengthening the abdominal and spinal stabilizing musculature.

Facet Joint Arthritis

Facet joint pain is present between 15% and 52% of the average population, with an increased percentage in elderly athletes due to degenerative arthritis. ^, Each vertebra is composed of a 3-joint complex that comprises 2 paired facet joints and the intervertebral disk. Each joint is composed of cartilage and synovial fluid to maintain mobility of joints. Facet joint (FJ) arthritis is a degenerative change between joints that can break down cartilage and form bone spurs. This is typically caused by aging, but can be heightened by repetitive extension, flexion, and torsion of the lumbar spine. There is a significant association with age, as 89% of people aged 65 and older are noted to have FJ arthritis on CT imaging. However, athletes can accelerate the degeneration process by using more repetitive extension motions, which is often seen in golfers, throwers, or gymnastics.

Presentation

The symptoms of FJ arthritis can range from being asymptomatic to pseudo-radicular lumbar pain. Although referral patterns of FJ are varied, the pain can be referred distally to the lower limbs causing a pseudo-radicular syndrome. The pain typically ends above the knee, but extends to the feet if complicated by osteophytes. Moreover, FJ arthritis can have claudication-type sensations, with pain worsening in the mornings and during periods of inactivity. The pain can be elicited at times during lumbar extension or FJ palpation.

Diagnosis

After eliminating disk herniation, spinal stenosis, and other immediate neurologic causes, FJ osteoarthritis can be higher on the differential. It is considered a rule-out diagnosis, as it does not produce consistent, specific symptoms. There are no physical examination maneuvers that can diagnose FJ arthritis. CT is the most sensitive technique, although MRI can be used to visualize surrounding soft tissues. Some studies have shown that MRI and other imaging modalities have not been reliable in diagnosing FJ osteoarthritis. ^, The most common features found on imaging include narrowing of the facet joint space, subarticular bone erosion, subchondral cyst, and osteophyte formation. Other invasive procedures like facet blocks have been used to identify and confirm the diagnosis, but can be associated with false positive rates. ^,

Management

Conservative management is considered first-line treatment in many cases. It is important to properly teach the patient about daily posture and exercise. Physical therapy can similarly be useful to restore posture and strengthen abdominal and neck flexor muscles to balance the extensors. Multimodal pain management consisting of NSAIDs, muscle relaxants, and acetaminophen can be used during acute flares.

There are more invasive techniques like ultrasound-guided facet blocks, which demonstrate 82% effectiveness for approximately 6 months. Steroid injections, however, have inconsistent data, suggesting they might be less beneficial in the management of chronic lower back pain. ^, Neurolysis, denervation of nerve fibers resulting in regeneration, is another technique reporting promising results. Neurolysis does not provide a permanent solution, but studies indicate that almost 60% of patients can expect 90% of pain reduction and 87% can expect 60% reduction lasting 12 months. No guidelines exist for surgical management. If complicated by spondylolisthesis or severe pain, lumbar decompressive laminectomy can provide relief occasionally.

Spondylolysis/Spondylolisthesis

Spondylolysis is a defect of the pars interarticularis, which can be induced by trauma, stress fracture, or recurrent microtrauma. Spondylolisthesis refers to the slipping of a vertebral body with respect to the adjacent body. The most common sites of injury are L5-S1 vertebrae followed by L4-L5. The main cause of spondylolisthesis is degenerative but athletes are at a higher risk. It is postulated that there could be microtrauma caused by repetitive lumbar extension from various activities like gymnastics, football, and wrestling. It is estimated that spondylolisthesis causes 70% to 80% of low back pain in adolescent athletes. Previous studies estimate that the prevalence of spondylolysis in wrestlers and weight lifters is 30% and 23%, respectively, compared with 6% to 18% of the US population. ^{, ,} Other risk factors for spondylolisthesis include anatomic variations such as spina bifida or scoliosis.

Presentation

Spondylolisthesis has an asymptomatic nature and often recognized incidentally. The pain is usually exacerbating with flexion and extension at the site of slippage. Direct pressure may also cause pain. Lying supine diminishes the pain by opening up the spinal canal and relieving pressure on the bony elements. A radiculopathy component can be identified, as nerve roots can be compressed, leading to narrowing of the nerve.

Diagnosis

Radiography is necessary for initial management and diagnosis of spondylolisthesis. It is possible to see abnormal alignment of the vertebral body or a pars defect, which can indicate ischemic spondylolisthesis. CT scan has the highest sensitivity and specificity. MRI can identify small tissues, but does not aid in visualization of the pars defect.

Management

Conservative management is considered first-line treatment. Orthoses are external devices that are flexible or rigid. There are 2 main types: thoracolumbosacral and lumbosacral orthoses. Flexible versions are used to decrease activity of paraspinal muscles and increase abdominal pressure. Rigid orthoses are effective in limited sagittal plane motion, but have limited control over rotation and lateral bending. Some studies have demonstrated little to no immobilization effect from wearing orthoses.

North American Spine Society spondylolisthesis guidelines suggest that surgical decompression may be considered for patients with low-grade degenerative spondylolisthesis that is refractory to conservative management. Many studies have also shown that fusion may have improved long-term outcomes compared with surgical decompression alone, but with increased surgical morbidity.