A 20 year Old Man With Chronic Back Pain Thinks He Is too Young For This Pain

A 20 year old man who is a college student presents to an orthopedic spine specialist with the complaint of chronic back pain that has lasted for the past few years. He denies any history of back trauma and says that the pain began insidiously about 3 years ago. He says that the pain is in located in the mid and lower back and is more upon waking and he feels stiff. The pain and stiffness improve after he is out of bed for a few hours. The pain worsens after prolonged sitting while he is taking his classes. He is physically active and runs three times per week and he feels hi back pain gets better after the exercise. He denies any numbness, weakness or incontinence.

Physical Examination:

• Well appearing young man in no acute distress.
• Palpation of back reveals mild tenderness only at his sacroilliac joints..
• he has difficult bending forward and laterally because of stiffness in his lower back.
• There is no asymmetry or lateral curvature of the spine.
• Neurological examination is normal
• All other organ systems are unremarkable.

On workup he has an ESR of 55 which is increased and the X ray of the spine is shown below:

 

This patient was diagnosed to have Ankylosing Spondylitis. 

Case Discussion:

Ankylosing spondylitis

Ankylosing spondylitis is a chronic inflammatory disease of the spine and pelvis that results in the eventual fusion of adjacent vertebrae, It is more common in males and patients present with complains of hip and low back pain that is worse in the morning and following periods of inactivity. The pain improves over the course of the day and with exercise. On examination there is limited range of motion in the spine and chest wall. Some patients may have associated peripheral arthritis, anterior uveitis and /or cardiac arrhythmias.

Radiographic features

Features predominantly affect the axial skeleton although can involve the peripheral joints in ≈20% of cases.

Plain film

Sacroiliac joints

• Sacroillitis is usually the first manifestation and is symmetrical and bilateral
• joints widen before they narrow
• subchondral erosions, sclerosis and proliferation on the iliac side of SI joints
• at endstage, the SI joint may be a thin line or not visible 

Spine

• early spondylitis is characterized by small erosions at the corners of vertebral bodies with reactive sclerosis (Romanus lesions of the spine: shiny corner sign)
• vertebral body squaring
• diffuse syndesmophyitic ankylosis can give a "bamboo spine" appearance
• interspinous ligament calcification can give a "dagger spine" appearance
• ossification of spinal ligaments, joints and discs (with fatty marrow within ossified disc, best seen on MRI)
• pseudoarthroses may form at fracture sites
• enthesophyte formation from enthesopathy
• non-infectious spondylodiscitis: Andersson lesion

Hips

Hip involvement is generally bilateral and symmetric, with uniform joint space narrowing, axial migration of the femoral head, and a collar of osteophytes at the femoral head-neck junction.

MRI

• may have a role in early diagnosis of sacroiliitis
• synovial enhancement on MR correlates with disease activity measured by inflammatory mediators
• enhancement of the interspinuous ligamants is indicative of an enthesitis
• increased T2 signal correlates with edema or vascularized fibrous tissue
• superior to CT in detection of cartilage, bone erosions, and subchondral bone changes
• useful in following treatment results in patients with active ankylosing spondylitis.