Lumbar Spine Disorders in Aging Athletes

Gordon R. Bell, MD

Dr. Bell or an immediate family member serves as a paid consultant to American Medical Foundation for Peer review & Education and Pfizer; and has received nonincome support (such as equipment or services), commercially derived honoraria, or other non-research–related funding (such as paid travel) from Saunders/Mosby-Elsevier.

Although physical decline is part of the aging process, the rate of decline varies and may be adversely affected by long-standing disuse and a sedentary lifestyle.¹ Between 1900 and 1988, the average life expectancy in industrialized Western countries increased by more than 60%, from 47 years to 75 years. Furthermore, the percentage of older individuals has accelerated more rapidly than other segments of the population, with those 85 years of age and older increasing 232% between 1960 and 1990 compared with a 39% overall growth in population during that 30-year period.² Currently, more than 25% of the population is older than 55 years.

There are many physiologic musculoskeletal manifestations of aging (Table 21-1). With muscle strength, for example, peak muscle strength occurs at 30 years of age and decreases by approximately 15% per decade between ages 50 and 70 years, such that by age 70 years, it is reduced by 30%. The spine contains all of the musculoskeletal anatomic structures listed in Table 21-1 and is therefore subject to a host of potential abnormalities as it ages.

Anatomically, spinal degenerative changes begin anteriorly in the disk (annulus fibrosus and nucleus pulposus) and secondarily involve the posterior elements (facet joints). As the annulus develops fissures and the nucleus pulposus undergoes reduction of its proteoglycan content, the disk space narrows. The ligamentum flavum is then under less tension and buckles, and secondary degenerative changes occur in the facet joints. The net effect of these changes is that the spinal canal undergoes progressive narrowing as a result of the infolding and thickening of ligamentum flavum anteriorly and facet arthropathy posteriorly.

The narrowing of the canal may or may not be accompanied by symptoms. When symptoms do occur, they can manifest as low back pain, radiculopathy, or both. The radicular symptoms are partially mechanical as a result of neural compression from the circumferential degenerative changes that narrow the spinal canal. Although symptoms from aging with degeneration of the lumbar spine can have a significant effect on everyone, they can have a profound effect on those accustomed to a very active lifestyle, such as former athletes.

Discussion of lumbar spine disorders in aging athletes comprises a myriad of potential concepts and issues. First, there is the gamut of conditions that may be included under lumbar spine disorders. These include intrinsic low back pain, low back pain from other nonspinal causes (e.g., hip disease and other organ causes), radicular syndromes (e.g., disk herniation and spinal stenosis), and vertebral compression fractures (VCFs).

Second, there is a whole separate discussion regarding the definition of aging. It is known, for example, that aging is associated with reduced activity and sarcopenia, particularly a reduction in type II (fast-twitch) muscle fibers.³ Muscle mass has been shown to decrease by approximately 1.25% per year after age 35 years, with further acceleration after age 70 years.⁴ In addition, women tend to deteriorate with age more than men. With regard to the spine, spinal disorders are generally more common as individuals age, regardless of whether or not they are athletes, former athletes, or nonathletes. This is due to both development of degenerative changes and a reduction in bone mass.

Third, there is the concept of what is meant by the term athlete. Does this mean those actively involved with athletics or merely former athletes? Does the term aging athlete, therefore, refer to an active professional athlete entering
the twilight of his or her career? Or does it refer to a still athletically active individual who is either a “weekend warrior” or is a physically active septuagenarian engaging in moderate aerobic activities? The term master is commonly used to designate athletes older than 35 years of age and typically older than 50 years.⁴ In addition, there is a wide variety of sports, and it may not be reasonable to assume that spine disorders encountered later in life in a former professional hockey player are the same as those encountered by a former long-distance runner. Furthermore, weight training is a common part of conditioning and training for many sports. It can be difficult, if not impossible, to determine if clinical symptoms or radiographic changes are due to the effect of such weight training for a sport or are due to the actual sport itself.

TABLE 21-1 Musculoskeletal manifestations of aging

Area	Effects of Aging	Protective Modifications or Treatments
Bone	Progressive loss of mineral density “Tubularization” of diaphyseal bone	Regular exercise Well-balanced diet Vitamin D and calcium supplementation Hormone therapy (women) Medical therapy (e.g., bisphosphonates)
Ligaments and tendons	Decreased fiber compliance Stiffness of ligaments and tendons Increased susceptibility to catastrophic failure Decreased glycosaminoglycan concentration Decreased collagen fiber bundle thickness Decreased vascularity	Regular exercise Preexercise stretching
Meniscus	Intrasubstance degeneration Loss of ability to dissipate stress Increased propensity to degenerative tears	Débridement of unstable degenerative tears^*
Articular cartilage	Decreased concentration of chondroitin sulfate; relative increase in keratan sulfate (nonosteoarthritic) Relative increase in chondroitin sulfate (osteoarthritic) Chondromalacia (cumulative damage)	Microfracture for selected full-thickness chondral lesions Débridement of unstable chondral lesions^* Glucosamine and chondroitin sulfate^* Hyaluronate viscosupplementation^*
Skeletal muscle	Sarcopenia Decreased type I and II muscle fiber loss Volumetric loss of individual fiber size Progressive muscle denervation Decreased mitochondrial volume Increased collagen content Degenerative ultrastructural changes Decreased muscle flexibility	Regular exercise, muscle training Preexercise stretching Hormonal supplementation^* Nutritional supplementation^*
^Routinely used with anecdotal success, but long-term benefits have not been clearly established. Reproduced from: Chen AL, Mears SC, Hawkins RJ: Orthopaedic Care of the aging athlete. JAAOS* 2005;13(6):407–416.

Finally, one must make a distinction between radiographic evidence of spinal degeneration and clinical symptomatology. Degenerative changes in the lumbar spine are ubiquitous with aging, regardless of the presence or absence of symptoms and regardless of whether or not the individual is or was athletic. In the general population, there is little, if any, correlation between such radiographic findings and symptoms because such findings relate more to age than to the presence or absence of symptoms. Although some data suggest that athletes in some sports have more degenerative changes and back pain than the general population, such information is hard to obtain in former and aging athletes. In addition to the issue of radiographic degenerative changes in the spines of athletes, there is also the issue of spinal bone mineral density (BMD) and whether or not BMD values correlate with risk of VCF in aging athletes.

Finally, no discussion of back pain and spinal disorders would be complete without consideration of other, nonspinal, conditions that can mimic back pain. This is particularly true of older individuals, including aging athletes, in whom other musculoskeletal conditions, such as hip arthritis, may mimic back pain (Table 21-2).⁵ It
should be noted that not all of the diagnoses listed in Table 21-2 are universally accepted as causing symptoms, such as a lumbar transitional vertebra causing midline low back pain.

TABLE 21-2 Differential diagnosis of low back pain in athletes

Diagnosis	Presentation
Low back strain	Belt-line or paravertebral pain with motion
Degenerative disk disease	Midline pain with sitting or loading
Lumbar transitional vertebra	Midline low back pain
Facet mediated pain	Midline and paramedian pain with extension
Spondylolisthesis	Mechanical midline and paramedian pain
Traumatic fracture	Midline pain at the level of injury
Disk herniation	Pain, numbness and weakness radiating into the leg
Lumbar spinal stenosis	Low back, buttock, and leg pain, improved with flexion
Cauda equina syndrome	Radicular symptoms with bowel and bladder dysfunction and saddle anesthesia
Spinal infection	Constant low back pain with fevers, chills, night sweats, recent infection or dental procedure
Tumor	Night pain, fever, older age (>60 years), weight loss
Intraabdominal or intrapelvic processes	Boring nonmechanical pain, GI disturbance
Renal disease or stones	Colicky pain, GI disturbance
Hip pathology	Groin pain, pain with rotation or weight bearing
Sacroiliac pathology	Buttock and posterior superior iliac spine area pain, pain with loading
Abdominal aortic aneurysm	Constant boring front to back pain
GI = gastrointestinal. Reproduced from Truumees E: Low back pain in the aging athlete. Semin Spine Surg 2010;22(4):222–233.

Epidemiology of Low Back Pain in Athletes

It is important to remember that low back pain is a symptom and not a diagnosis. In many cases, the actual pathology responsible for back pain is unknown, and no specific diagnosis can be discerned.⁶ This is generally of little consequence because back pain is often a self-limited condition. In Western civilizations, low back pain occurs in approximately 80% to 90% of the adult population. An association has been shown between heavy physical loading and back symptoms and degenerative changes, although most studies have focused on occupational loading rather than that associated with athletics. There are many obvious differences between occupational loading and athletic loading of the spine, and one significant factor may be the duration and frequency of loading between the two types of activities. As noted by Lundin et al, comparisons between back pain in athletes and back pain in the general population are difficult for many reasons.⁷ These include differences in motivation, pain perception, susceptibility, and physical activity between the two groups. In addition, relatively minor pain might be significantly more important in an athlete than a nonathlete because an athlete’s performance could be hampered by even a small degree of pain. Conversely, some athletes might be able to ignore some pain that would otherwise hamper daily activities in a nonathlete.⁸ In general, there are conflicting reports on the association between athletics and low back pain.⁹

The protective effect of strenuous physical activity in seniors was demonstrated in a population-based study of Danish twins 70 years of age and older.¹⁰ Although this study did not look specifically at senior athletes, it found that more frequent and strenuous physical activity, defined as more than 30 minutes of walks or bike rides, sports, or dancing, was associated with a significantly lower risk of developing back pain than no physical activity or less strenuous activity. In athletes, the data on back pain are inconclusive, with some studies reporting increased rates of low back pain ranging up to 75% in young athletes.¹¹^,¹²^,¹³^,¹⁴^,¹⁵^,¹⁶^,¹⁷ The risk of developing low back pain is influenced by gender, age, type of sport, type and intensity of training techniques, and other factors. For example, low back pain has been reported to be more common
in certain sports than others, particularly in sports associated with heavier loads, such as wrestling and gymnastics. Swärd et al reported that radiographic abnormalities in the thoracolumbar spine occurred in 36% to 55% of a group of 142 elite athletes representing gymnastics, wrestling, soccer, and tennis.¹² When compared with control participants, wrestlers and elite gymnasts were found in one study to have back pain at frequencies of 69% and 85%, respectively.¹²^,¹⁸ Other studies have also reported an increased incidence of low back pain ranging from 25% to 75% in gymnastics¹³^,¹⁵ and in other sports, such as football¹⁶^,¹⁷ and wrestling.⁷ These studies generally represented findings of active athletes, and whether or not they would hold true for aging athletes is unknown.

Only gold members can continue reading. Log In or Register to continue