by Fredrick Wigley, M.D.
A seventy-one year old gentleman complained of weakness in his thighs, stiffness in his hip girdle and discomfort from his hips to his knees. The problem had progressively worsened over approximately seven years, reaching a zenith in the last six months. He was unable to stand up from a chair without pushing himself up with his arms and throwing his weight forward.
The patient also complained of general stiffness after resting for a short period. Hip and thigh pain on short-distance walks was profound. He found improvement in the hip girdle pain when lying flat or sitting. he had problems with decreased mobility of his back for years and was told he had “spondylosis” of his spine. He was otherwise in good health.
He denied paresthesias or numbness in any of the extremities, or bowel or bladder incontinence. There was no recent history of fever, chills, weight loss or decreased appetite. He had no upper extremity complaints. None of his joints had ever been swollen or red. He denied rashes.
His general examiniation was unremarkble. The musculoskeletal exam demonstrated mild limitation of motion of the cervical spine, and normal range of motion of the thoracic spine. His lumbar spine was remarkable for loss of the normal lordotic curve (flattening), and decreased range of motion in all planes. He had no pain or percussion over the spine or sacroiliac joints.
His peripheral joint examination was remarkable for marked reduction o both internal and external rotation of both hips. There was bony enlargement of the DIP joints of both hands consistent with Heberden’s nodes. Shoulders, elbows, wrists, MCPs, knees, ankles and small joints of the feet were normal. There was no evidence of swelling, warmth, erythema or deformity of any of these joint.
The neurological exam was also unremarkable including strength evaluations of all muscoe groups of the upper and lowere extremities.
Normal including erythrocyte sedimentation rate (ERS) and muscle enzymes.
X-rays of his hips and lumbar spine were ordered.
1. [ ]Parkinson’s disease
2. [ ]Polymyositis
3. [ ]Osteoarthritis of thehips, bilateral
4. [ ]Spinal stenosis
5. [ ]Diffuse idiopathic skeletal hyperostosis
6. [ ]Ankylosing spondylitis
7. [ ]More than one of the above
This patient presents with self-reported hip girdle weakness, exercise induced fatigue, and discomfort and stiffness, in the hip girdle and upper thighs. His presentation is a diagnostic challenge since his symptoms could result from a neurological, myopathic, or articular disorder. Distinguishing the source of his discomfort is critical for initiation of appropriate therapy.
Parkinson’s disease may present with a sensation of stiffness, imbalance and difficulty with initiation of gait, and can mimic musculoskeletal disease such as osteoarthritis of the hips or knees. This patient, however, did not have any of the typical features of Parkinson’s disease such as flat affect, cogwheel rigidity, or shuffling gait.
Polymyositis typically presents with proximal muscle weakness and, to a much lesser extent, proximal muscle pain. Although the patient subjectively felt weak in the lower extremities, his strength on physical examination was excellent. His difficulty rising from a chair was felt to be secondary to the loss of motion of both hips. Good proximal strength, normal CPK and low ESR effectively ruled out an inflammatory myopathy.
The severe loss of motion of the hips indicated that the patient had articular pathology in the hips. As shown in Figure 1, this was due to severe osteoarthritis as evidenced by severe loss of joint space bilaterally (primarily on the superior surfaces), sclerosis, and hypertrophic bone formation on both the femoral heads and acetabuli. Undoubtedly, severe osteoarthritis of the hips was contributing significantly to this patient’s thigh pain and sense of weakness, but it could not account for his decreased spinal range of motion, nor the exercise induced fatigue in his buttocks and thighs.
A primary disease of the spine complicated by spinal stenosis was the most likely explanation for these symptoms and findings. The dramatic loss of motion of the spine and history of “spondylosis” suggested two potential etiologies: 1) inflammatory spondyloarthropathy such as ankylosing spondylitis; or 2) exaggerated osteoarthritis of the spine known as “diffuse idiopathic skeletal hyperostosis” (DISH) or Forestier’s Disease. Both ankylosing spondylitis and DISH can cause limitation of lumbar motion, as well as decreased thoracic and cervical spine motion. Both can be associated with hip disease and both can cause spinal stenosis.
Ankylosing spondylitis (AS) often begins in young men with inflammation and tenderness of the sacroiliac joints. However, over time, the joints will fuse and become asymptomatic and nontender. The lack of sacroiliac tenderness in this elderly gentleman with longstanding symptoms, the normal sedimentation rate, and advanced age of onset of symptoms rendered AS an unlikely diagnosis. Furthermore, hip disease, when present in AS, results from ankylosis (similar to the spine) and not from osteoarthritis as in this gentleman. Clinically, DISH with spinal stenosis seemed a more likely etiology for his symptoms.
Spinal stenosis should be suspected in patients in whom low back pain is relieved by sitting or leaning forward and exaggerated by extension. [These symptoms are opposite of those of degenerative disc disease with nerve root impingement.] These patients will experience an uncomfortable feeling in the buttock and upper legs (rarely it can extend into the lower legs) that mimics vascular claudication and, therefore, is called “pseudoclaudication”. Narrowing of the spinal canal is caused by osteophytes at the facet joints, bulging of the disc centrally, and/or hypertrophy or calcification of the spinal ligaments.
Occasionally, as in this patient, both hip disease and spinal stenosis can coexist. In this situation, it is clinically difficult to determine which problem is causing the most disability. Local instillation of lidocaine into the hip joint can distinguish whether the hip is the source of the discomfort or pain. If spinal stenosis is the problem, then surgical decompression is usually successful and is the preferred approach.
Our patient’s symptoms were thought to be due to his hip disease because of the severe limitation of movement. However, an investigation to rule out spinal stenosis was undertaken. X-rays of the lumbar spine showed only minimal degenerative disc disease but large, coarse osteophytes that bridged the lower vertebral bodies (Figure 2). These findings are classic for DISH. Criteria for DISH require that new bone formation bridge four contiguous vertebral bodies in the absence of significant degenerative disk disese and in the absence of inflammatory sacroiliac or facet changes. DISH can occur in the absence of symptoms -e.g., in the thoracic spine. There is a tendency for DISH to involve the right side of the thoracic spine. There is often a gap between the new bone and the adjacent vertebrae or disc. In contrast, in AS, fusion of vertebral bodies occurs by delicate, vertical calcification of ligaments resulting in “syndesmophytes”. An example of this is shown below in (Figure 3) from a patient with ankylosing spondylitis. The calcification directly abuts the vertebral bodies and discs. Squaring of the vertebral bodies, as their corners are resorbed by an enthesitis (inflammation at the sites of ligamentous or tendinous insertion) occurs also. In addition to plain films of the lumbar spine, an MRI scan was also performed, and this did not show spinal stenosis (MRI not shown).
X-rays of the pelvis in this patient showed “whiskering” around the brim of the pelvis and a difficult-to-visualize right sacroiliac (SI) joint (Figure 1). “Whiskering” of bone can be seen in both DISH and AS as a consequence of enthesitis at ligamentous insertions around the pelvis. An x-ray of the SI joint was ordered to exclude evidence for inflammatory sacroiliac disease, and it was normal as would be expected with DISH (x-ray not shown). In contrast, in AS, the SI joint may exhibit ankylosis.
Distinguishing, AS from DISH can be a challenge since both can present with hip disease and decreased range of motion of the spine. DISH is found primarily in middle aged men and is associated with diabetes mellitus, while AS occurs in younger individuals and may be associated with arthritis of the peripheral joints and other extra-spinal manifestations such as uveitis, aortitis or pulmonary fibrosis. The back symptoms of AS often provide clues that suggest an inflammatory process such as stiffness in the morning and with prolonged sitting, nighttime pain, improvement with motion and with anti-inflammatory medications. DISH is often asymptomatic or associated with stiffness and loss of motion with minimal pain. Pain can occur if impingement or inflammatory reactions complicate the process. Multiple sites of hyperostosis can occur causing bony spurs (e.g. elbow, heel). DISH may co-exist with another inflammatory disease, including a spondyloarthropathy. There are several reports of cases with both AS and DISH in the same patient.
Both AS and DISH can be associated with hip disease. In DISH, the radiographic appearance is consistent with degenerative joint disease as in this patient. In AS, the hip disease can have different types of progression. One form, usually in younger individuals, is a non-destructive ankylosing with preservation of the joint space. This is usually bilateral and associated with severe loss of normal hip motion. The other form, more common in older individuals, is a destructive unilateral process with global loss of joint space and central migration of the femoral head typical of an inflammatory synovitis. Both DISH and AS have a tendency to form hypertrophic bone around the hip. This makes surgical intervention more complex in these patients. Studies indicate that there is approximately a 30% chance of clinical re-ankylosis, and 50-60% chance of radiological re-ankylosis, in AS patients followed for greater that 6 months after hip arthroplasties. It is presumed that the ankylosis is due to new bone formation at ligamentous and tendinous insertions around the hip. Attempts have been made to decrease hypertrophic bone formation by the use of non-steroidal anti-inflammatory medications the time of surgery or local low dose radiation to the hip girdle but results are controversial.
The decision to move to total hip replacement in these patients should be prompted by intractable pain and/or advanced disability with poor quality of life. Obviously, if range of motion is the sole problem, then surgical replacement that is complicated by re-ankylosing will not solve the problem. On the other hand if pain is the major clinical problem, then surgery can be most helpful even if some re-ankylosis occurs. Our patient had progressive restriction of hip function that had progressed over 6-7 years. He was limited to short distance walking and could not rise from a chair without great difficulty. Spinal stenosis was excluded and the SI joints were normal. It was thought that he had DISH with associated advanced degenerative hip disease. It was recommended that he have total hip replacement.
Final Diagnosis: DISH with associated severe bilateral degenerative disease of the hips.
Resnick D. Diagnosis of Bone and Joint Disorders (vol 4), 3rd ed., W. B. Saunders Co, 1994.
Lewallen DG. Heterotonic Ossification Following Total Hip Arthroplasty. Instr Course Lect 44:287-292, 1995.
Ramos-Remus C, et al. Radiologic Features of DISH May Mimic Ankylosing Spondylitis. Clin Exp Rheumatol 11:603-608, 1993.
Moreno A, etal. Sumultaneous occurrence of Diffuse Idiopathic Skeletal Hyperostosis and Ankylosing Spondylitis. Rev Rhum Engl Ed 63:292-295, 1996.