Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Decision Making and Classification

The primary decision that a sports physician must make when confronted with a thoracolumbar condition is whether the athlete has a significant mechanical and/or neurological instability requiring urgent or emergent stabilization.

The spinal problem can be categorized initially as a high-energy injury, a low-energy injury, or even a no-injury situation. In turn, high-energy injuries to the spine may be classified as spinal traumatic conditions, whereas low-energy injuries and no-injury situations may be classified as nontraumatic back pain.

The athlete presenting with major neurological deficits but with no history, or a very minor history, of trauma must raise a red flag the sports physician’s mind. The suspicion of an underlying pathology, such as neoplasia, demyelinating disease, infection, or a peripheral neuropathy, must be investigated promptly.

High-energy injuries are more prevalent in sporting activities such as horseback riding, parachuting, motor sports, downhill skiing, and the recent popular extreme sports, such as skateboarding, snowboarding, freestyle skiing, and BMX cycling.

Spinal fractures must be suspected when a first responder attends these fallen athletes, especially if the athlete has a depressed level of consciousness or other major distracting injury . Life-threatening injuries are dealt with first, and precautions to minimize movement of the spinal column are taken.

Plain-film radiographs are obtained, and focused CT is performed on areas of clinical suspicion. Fractures are classified to assist with the treatment and prognostication and to help standardize research into therapeutic options. Ideally, the classification system should be simple yet precise as well as logical yet comprehensive.

The Denis classification system was based on the analysis of plain-film radiographs and CT scans of spinal fractures. This system uses the concept of dividing the spine into three columns. The anterior column includes the anterior longitudinal ligament and the anterior half of both the vertebral body and the intervertebral disc.

The middle column includes the posterior longitudinal ligament and the posterior half of both the vertebral body and the intervertebral disc. The posterior column comprises the elements of the posterior bony arch and the attached ligamentous structures.

Denis classifies the types of injuries as compression fractures, burst fractures, seatbelt-type injuries, and fracture dislocations. The subgroups are based on the mechanism of injuries.

Another recent classification is the modified AO/ASIF classification of thoracolumbar injuries. This system describes three main types of fractures: compression, distractions, and multidirectional with translation.

Follow up examinations for comparison with the baseline neurological assessment are done to ensure detection of any neurological deterioration. Consultation and transfer to a spinal surgery center for definitive care is carried out properly if the clinical examination and investigations reveal any significant fractures or neurological deficits.

The differentiation by a sports physician between a burst fracture and a fracture dislocation is not as crucial to the patient as ensuring that the spinal fracture is promptly recognized and appropriately referred for definitive management.

If the injury has a relatively low-energy etiology or is recurrent in nature, the detailed history and physical examination will determine if any significant neurological instability exists. If a cauda equina syndrome or myelopathy is found, prompt referral for decompression management is required after appropriate emergent imaging.

The majority of low-energy injuries are classified as soft-tissue injuries requiring no further investigation but, rather, prompt rehabilitation after a short period of rest to minimize the deconditioning and stiffening that occurs with inactivity. The soft tissues involved are the musculotendinous strains or ligamentous sprains with associated contusions, spasms, and inflammation.

The pain usually is nonradiating, and the exact etiology generally is not identified. Predisposing factors include inadequate conditioning, poor posture, overuse activity, and improper mechanics for lifting or performing the sport.

The classification of these acute nontraumatic back pains developed by Dr. Hamilton Hall is based on the clinical presentation of the pain and has been very useful in planning initial treatment . The classification does not focus on the exact pathology of the pain generator but, rather, on the history and concordant physical examination.

Hall’s classification system involves four different patterns, and the nomenclature specifically does not assign blame to any one anatomical structure as the pain generator.

Pattern 1 pain is a back-dominant pain, usually in the low back or buttock, which is aggravated by activities that flex the thoracolumbar spine, such as bending forward or prolonged sitting.

The physical examination reproduces the pain with forward flexion, and two pattern 1 subsets exist based on the physical examination. Pattern 1 fast responders have alleviation of the pain with spinal extension, whereas pattern 1 slow responders either have no change in the pain or have equal or more pain with spinal extension.

The neurological exam is normal for pattern 1. This pain likely originates from the outer aspect of the annulus fibrosis or the adjacent ligaments or end plates, but the exact pathology is not required to start treatment.

Pattern 2 pain also is a back-dominant pain that is worsened with extension but not with flexion activities. On physical examination, the pain is reproduced with extension but is either improved or not affected by flexion. The neurological examination of pattern 2 pain also is normal. The pain generators likely are in the ligaments and joints of the posterior neural arch complex.

Pattern 3 pain is a leg-dominant pain that is aggravated by spinal movement. Patients also may report pain in the back. As with pattern 1 pain, pattern 3 patients fall into two subsets, as determined by the physical examination.

Pattern 3 fast responders will have some reduction of their leg symptoms by specific postures. Pattern 3 slow responders will have no change in pain with some postures and will have aggravation of pain with other postures; no pain-alleviating postures found.

The neurological examination will be positive for signs of nerve root irritation, such as straight-leg raising or the femoral nerve stretch test. Reproduction of the patient’s pain will occur with testing for signs of nerve root irritation. The most common pain generator for pattern 3 patients is an acute herniated disc.

Pattern 4 pain is a leg-dominant pain that is intermittent and brought on by activities or postures that maintain spinal extension. Relief occurs soon after the patient changes his or her posture to a flexed position. The physical examination usually is negative for neurological deficits or signs of nerve root irritation.

Classically, pattern 4 pain is a neurogenic claudication type of pain. The cause of this neurogenic claudication usually is spinal stenosis, but not all patients with spinal stenosis depicted on their radiographs will have neurogenic claudication. In athletes with pattern 4 pain, the neurological claudication may have been associated with developmentally short pedicles, leading to a smaller, trefoil-shaped spinal canal.

Recurrent or persistent mechanical back pain in an athlete without signs of nerve root irritation should signal the possibility of a spondylolysis, which is considered to be a type of stress fracture of the pars interarticularis. Forward subluxation of the vertebral body over another vertebrae is termed a spondylolisthesis.

A spondylolisthesis can occur without a pars defect in which the facets are severely degenerated, fractured, or surgically removed, resulting in segmental instability. The pars defect is the radiolucent “collar” on the “Scottie dog” that is seen on plain oblique radiographs of the lumbar spine . The incidence of spondylolytic spondylolisthesis varies in different sporting activities

The grading of the degree of spondylolisthesis is based on the percentage of the AP diameter of the vertebral body that has slipped forward. Grade 1 slips are up to 25%, grade 2 spondylolisthesis are between 26% and 50%, and so on.

The clinical presentation usually is a pattern 2 type of pain; however, a pattern 3 nerve root irritation may develop because of compression of the nerve root exiting beneath the pseudoarthrosis of the pars defect. Imaging with CT delineates the defect well.

If the injury was a high-energy hyperextension force, an acute fracture of the pars interarticularis may occur. The CT scan will show an acute fracture without sclerosis at the fracture site, and a bone scan will show increased uptake 2 to 3 days after the injury and lasting for 6 to 9 months. The defect may be unilateral on both the CT and the bone scan.

A consultation with a sports medicine physician may take place several weeks to months after the initial onset, and by this time, the CT and bone scans may show sclerotic healing or pseudoarthrosis and the bone scan still shows some increased activity at the defect site.

If the bone scan is normal, then the defect or sclerotic area is an old lesion. Patient compliance with the rehabilitation scheme is the key to conservative treatment, and reassurance that the painful back can be controlled is paramount in obtaining compliance.

The knowledge that these athletes cannot only perform with these defects but also excel usually provides a vote of confidence in the rehabilitation program. Surgery may be required if neurological signs develop or the pain becomes unremitting.

Nonpainful back conditions, such as scoliosis or kyphosis, can be followed by three foot-standing AP and lateral radiographs using the Cobb technique of measuring the deformity. Most scoliotic deformities will not require surgical correction.

Standard back-conditioning exercises specific to the sport in which athlete is participating will help to minimize the usual incidence of back pain that similar athletes with normal-contoured spines will experience. In adolescents, the deformity should be followed every 6 to 12 months clinically, with radiographs being obtained if the structural curve is increasing on the physical examination.

Bracing may be recommended for moderate-sized curves if the adolescent athlete is still in the growth spurt. For curves that are rapidly progressing past 45° of scoliosis in a skeletally immature adolescent, surgical treatment to stabilize the curve may be warranted.

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