Degenerative orthopedic disorders

Degenerative orthopedic disorders

OSTEOARTHRITIS (Osteoarthrosis)

Osteoarthritis (OA) is a degenerative joint disease. Aetiology is multifactorial, and still not understood. Commonly it is thought to be wear and tear of joints as one ages. Two types of OA are recognised – primary and secondary.

  • Primary OA: This occurs in a joint de novo. It occurs

in old age, mainly in the weight bearing joints (knee and hip). In a generalised variety, the trapezio-metacarpal joint of the thumb and the distal inter-phalangeal joints of the fingers are also affected. Primary OA is commoner than secondary OA.

  • Secondary OA: In this type, there is an underlying primary disease of the joint which leads to degeneration of the joint, often many years later. It may occur at any age after adolescence, and occurs commonly at the hip

Causes of secondary OA of the hip

Avascular necrosis

  • Idiopathic
  • Post-traumatic e.g., fracture of femoral neck
  • Alcoholism
  • Post-partum osteonecrosis
  • Chronic liver failure
  • Patient on steroids
  • Patient on dialysis
  • Sickle cell anaemia

Coxa vara

Congenital dislocation of hip (CDH) Old septic arthritis of the hip Malunited fractures

Fractures of the acetabulum

 

Predisposing factors are: (i) congenital mal- development of a joint; (ii) irregularity of the joint surfaces from previous trauma; (iii) previous disease producing a damaged articular surface; (iv) internal derangement of the knee, such as a loose body; (v) mal-alignment (bow legs etc.); and (vi) obesity and excessive weight.

PATHOLOGY

Osteoarthritis is a degenerative condition primarily affecting the articular cartilage. The first change observed is an increase in water content and depletion of the proteoglycans from the cartilage matrix. Repeated weight bearing on such a cartilage leads to its fibrillation. The cartilage gets abraded by the grinding mechanism at work at the points of contact between the apposing articular surfaces, until eventually the underlying bone is exposed. With further ‘rubbing’, the subchondral bone becomes hard and glossy (eburnated). Meanwhile, the bone at the margins of the joint hypertrophies to form a rim of projecting spurs known as osteophytes. A similar mechanism results in the formation of subchondral cysts and sclerosis.

The loose flakes of cartilage incite synovial inflammation and thickening of the capsule, leading to deformity and stiffness of the joint. Often one compartment of a joint is affected more than the other. For example, in the knee joint, the medial compartment is affected more than the lateral, leading to a varus deformity (genu varum).

 

CLINICAL FEATURES

The disease occurs in elderly people, mostly in the major joints of the lower limb, frequently bilaterally. There is a geographical variation in the joints involved, depending probably upon the daily activities of a population. The hip joint is commonly affected in a population with western living habits, while the knee is involved more commonly in a population with Asian living habits i.e., the habit of squatting and sitting cross legged.

Pain is the earliest symptom. It occurs intermittently in the beginning, but becomes constant over months or years. Initially, it is dull pain and comes on starting an activity after a period of rest; but later it becomes worse and cramp-like, and comes after activity. A coarse crepitus may be complained of by some patients. Swelling of the joint is usually a late feature, and is due to the effusion caused by inflam- mation of the synovial tissues. Stiffness is initially due to pain and muscle spasm; but later, capsular contracture and incongruity of the joint surface contribute to it. Other symptoms are: a feeling of ‘instability’ of the joint, and ‘locking’ resulting from loose bodies and frayed menisci.

EXAMINATION

Following findings may be present:

  • Tenderness on the joint line
  • Crepitus on moving the joint
  • Irregular and enlarged-looking joint due to formation of peripheral osteophytes
  • Deformity – varus of the knee, flexion-adduction-external rotation of the hip
  • Effusion – rare and transient
  • Terminal limitation of joint movement
  • Subluxation detected on ligament testing
  • Wasting of quadriceps femoris muscle
INVESTIGATIONS

Radiological examination: The diagnosis of osteoarthritis is mainly radiological. The following are some of the radiological features:

  • Narrowing of joint space, often limited to a part of the joint e.g., may be limited to medial compartment of tibio-femoral joint of the knee.
  • Subchondral sclerosis – dense bone under the articular surface
  • Subchondral cysts
  • Osteophyte formation
  • Loose bodies
  • Deformity of the joint

Other investigations are made primarily to detect an underlying cause. These consist of the following:

  • Serological tests and ESR to rule out rheumatoid arthritis
  • Serum uric acid to rule out gout 
  • Arthroscopy, if a loose body or frayed meniscus is suspected

 

TREATMENT

Principles of treatment: Once the disease starts, it progresses gradually, and there is no way to stop it. Hence efforts are directed, wherever possible, to the following:

  1. To delay the occurrence of the disease, if the disease has not begun
  2. To stall progress of the disease and relieve symptoms, if the disease is in early stages.
  3. To rehabilitate the patient, with or without surgery, if his disabilities can be partially or completely alleviated.

Methods of treatment: To achieve the above objectives, the following therapeutic measures may be undertaken:

  1. Drugs: Analgesics are used mainly to suppress pain. A trial of different drugs is carried out to find a suitable drug for a particular patient. Long-acting formulations are
  2. Chondroprotective agents: Agents such as Glucosamine and Chondroitin sulphate have been introduced, claiming to be the agents which result in repair of the damaged Their role as disease modifying agents has yet not been established, but these could be tried in some early cases.
  3. Viscosuplementation: Sodium Hylarunon has been introduced. It is injected in the joint 3-5 times at weekly interval. It is supposed to im- prove cartilage functions, and is claimed to be chondroprotective.
  4. Supportive therapy: This is a useful and harmless method of treatment and often gives gratifying results. It consists of the following:
    • Weight reduction, in an obese
    • Avoidance of stress and strain to the affected joint in day-to-day activities. For example, a patient with OA of the knee is advised to avoid standing or running whenever Sitting cross legged and squatting is harmful for OA of the knee.
    • Local heat provides relief of pain and
    • Exercises for building up the muscles controlling the joint help in providing stability to the
    • The local application of counter-irritants and liniments sometimes provide dramatic relief.
  5. Surgical treatment: In selected cases, surgery can provide significant Following are some of the surgical procedures performed for OA:
    • Osteotomy: Osteotomy near a joint has been known to bring about relief in symptoms, especially in arthritic joints with deformities. A high tibial osteotomy for OA of the knee with genu varum , and inter-trochanteric osteotomy for OA of the hip have been shown to be useful for pain
    • Joint replacement: For cases crippled with advanced damage to the joint, total joint replacement operation has provided remarkable rehabilitation. These are now commonly performed for the hip and An artificial joint serves for about 10-15 years.
    • Joint debridement: This operation is  not so popular In this, the affected joint  is opened, degenerated cartilage smoothened, and osteophytes and the hypertrophied synovium excised. The results are unpredictable.
    • Arthroscopic procedures: Arthroscopic removal of loose bodies, degenerated menis- cal tears and other such procedures have become popular because of their less invasive nature. In arthroscopic chondroplasty, the degenerated, fibrillated cartilage is excised using a power-driven shaver under arthroscopic vision. Results are unpredictable

CERVICAL SPONDYLOSIS

This is a degenerative condition of the cervical spine found almost universally in persons over 50 years of age. It occurs early in persons pursuing ‘white collar jobs’ or those susceptible to neck strain because of keeping the neck constantly in one position while reading, writing etc.

PATHOLOGY

The pathology begins in the intervertebral discs. Degeneration of disc results in reduction of disc space and peripheral osteophyte formation. The posterior intervertebral joints get secondarily involved and generate pain in the neck. The osteophytes impinging on the nerve roots give rise to radicular pain in the upper limb. Exceptionally, the osteophytes may press on the spinal cord, giving rise to signs of cord compression. Cervical spondylosis occurs most commonly in the lowest three cervical intervertebral joints (the commonest is at C5-C6).

CLINICAL FEATURES

Complaints are often vague. Following are the common presentations:

  • High tibial osteotomy
  • Total knee replacement
    • Osteophytes at the vertebral margins, anteriorly Narrowing of intervertebral disc spaces (most Radiating pain: Patient may present with pain radiating to the shoulder or downwards on the outer aspect of the forearm and hand. There may be paraesthesia in the region of a nerve root, commonly over the base of the thumb (along the C6 nerve root). Muscle weakness is pain and stiffness: This is the commonest presenting symptom, initially intermittent but later persistent. Occipital headache may occur if the upper-half of the cervical spine is affected.
        • Giddiness: Patient may present with an episode of giddiness because of vertebro-basilar syndrome.
        EXAMINATION

        There is loss of normal cervical lordosis and limitation in neck movements. There may be tenderness over the lower cervical spine or in the muscles of the para-vertebral region (myalgia). The upper limb may have signs suggestive of nerve root compression – usually that of C6 root involvement. Motor weakness is uncommon. The lower limbs must be examined for signs of early cord compression (e.g. a positive Babinski reflex etc.).

DIFFERENTIAL DIAGNOSIS

The diseases to be considered in differential diagnosis of cervical spondylosis are: (i) other causes of neck pain such as infection, tumours and cervical disc prolapse; and (ii) other causes of upper limb pain like Pancoast tumour, cervical rib, spinal cord tumours, carpal tunnel syndrome etc.

TREATMENT

Principles of treatment: The symptoms of cervical spondylosis undergo spontaneous remissions and exacerbations. Treatment is aimed at assisting the natural resolution of the temporarily inflamed soft tissues. During the period of remission, the prevention of any further attacks is of utmost importance, and is done by advising the patient regarding the following:

  1. Proper neck posture: Patient must avoid situations where he has to keep his neck in one position for a long time. Only a thin pillow should be used at
  2. Neck muscle exercises: These help in improving the neck

During an episode of acute exacerbation, the following treatment is required:

  • Analgesics
  • Hot fomentation
  • Rest to the neck in a cervical collar
  • Traction to the neck if there is stiffness
  • Anti-emetics, if there is giddiness

In an exceptional case, where  the  spinal cord  is compressed by osteophytes, surgical decompression may be necessary.

LUMBAR SPONDYLOSIS

This is a degenerative disorder of the lumbar spine characterised clinically by an insidious onset of pain and stiffness and radiologically by osteophyte formation.

CAUSE

Bad posture and chronic back strain is the commonest cause. Other causes are, previous injury to the spine, previous disease of the spine, birth defects and old intervertebral disc prolapse.

PATHOLOGY

Primarily, degeneration begins in the intervertebral joints. This is followed by a reduction in the disc space and marginal osteophyte formation. Degenerative changes develop in the posterior facet joints. Osteophytes around the intervertebral foramen may encroach upon the nerve root canal, and thus interfere with the functioning of the emerging nerve.

 

DIAGNOSIS

Clinical features: Symptoms begin as low backache, initially worst during activity, but later present almost all the time. There may be    a feeling of ‘a catch’ while getting up from a sitting position, which improves as one walks a few steps. Pain may radiate down the limb up   to the calf (sciatica) because of irritation of one  of the nerve root. There may be  complaints  of transient numbness and paraesthesia in the dermatome of a nerve root, commonly on the lateral side of leg or foot (L5, S1 roots) respectively.

EXAMINATION

The spinal movements are limited terminally, but there is little muscle spasm. The straight leg raising test (SLRT) may be positive if the nerve root compression is present.

RADIOLOGICAL FINDINGS

Good AP and lateral views of the lumbo-sacral spine (Fig-35.4) should be done after preparing the bowel with a mild laxative and gas adsorbent like charcoal tablets. It is particularly difficult in obese patients, the ones usually suffering from this disease. Following signs may be present:

  • Reduction of disc space
  • Osteophyte formation
    • Narrowing of joint space of the facet joints
    • Subluxation of one vertebra over another

     

    TREATMENT

    Principles of treatment: Like cervical spondylosis, lumbar spondylosis also undergoes spontaneous remissions and exacerbations. Treatment is essentially similar to cervical spondylosis. In the acute stage, bed rest, hot fomentation and analgesics are advised. As the symptoms subside, spinal exercises are advised. In some resistant cases, a lumbar corset may have to be used at all times. Spinal fusion may occasionally be necessary.

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