LEGG-CALVE-PERTHES’ DISEASE (Coxa plana, Pseudocoxalgia)

Explanation:

Shallow acetabulum

A shallow acetabulum correlates poorly with outcome in congenital dislocation of hip. In addition to a, band d other ‘Head at Risk’ signs are diffuse metaphyseal reaction and horizontal physis.

Explanation:

Ans.D

It is also known as the Pars Plana and Pseudo Coxalgia. It is an osteochondritis of the femoral head. The femoral head becomes partly or wholly avascular and deformed.
Etiology is not definitely known. It is supposed to be due to recurrent episodes of ischemia of the femoral head in the susceptible age group, probably precipitated by episodes of synovitis.
Pathology: the disease progresses in three ill-defined stages:

• Stage of synovitis
• Stage of trabecular necrosis
• Stage of healing

Clinical features:
Commonly seen in the age group of 5 to 10 years. Child present with pain in the hip which often radiates to the knee or may also present with limp or hip stiffness. On examination, the finding is minimal. sometimes the only finding being limitation of abduction and internal rotation and shortening.

X-ray shows collapse and sclerosis of the epiphysis of the femoral head. hip joint space is increased. A bone scan may show a decreased uptake by the head of the femur.
Treatment: The primary aim is to prevent the head from ill shaping while the bone is in the softening phase. The head is required to be kept inside the acetabulum while the revascularization takes place (i.e. containment). This may be achieved by corrective methods (plaster, splint etc.) or by operation (containment osteotomy).

Explanation:

Bone scan and MRI are investigations to establish a diagnosis earlier. Diagnostic accuracy of 97-99% for MRI compared to 88-93% for radiography.

Ref: Diagnostic Imaging of Musculoskeletal Diseases: A Systematic Approach By Akbar Bonakdarpour, William R. Reinus, Jasvir S. Khurana, 2009, Page 112; Tachdjian’s Paediatric Orthopaedics, 3rd Edition, Page 680; Campbell’s Operative Orthopaedics, 10th Edition, Page 1155

Explanation:

Ans. C i.e. Femoral head

Osteochondritis

Perthes disease:

– Osteochondritis of femoral head

– Adduction is unaffected

– IOC for Perthes disease: MRI

• Osteochondritis of lunate: Kienbock’s disease
• Osteochondritis of tibial tubercle: OschGood’s Schlatter’s disease
• Osteochondritis of calcaneum: Sever’s disease

Explanation:

Ans. is ‘d’ i.e., Unknown

PERTHE’S DISEASE (LEGG-CALVE PERTHE’S DISEASE)

• Perthe’s disease is also known as osteochondritis deformans juvenilis or Coxa piano or Pseudocoxalgia.
• Perthe’s disease is an osteochondritis of the epiphysis of the femoral head (capital femoral epiphysis). In the disease, the femoral head becomes partly or wholly avascular and deformed. The disease occurs commonly in males in the age group of 5-10 years.

Etiology of Perthe’s disease

• Perthe’s disease is the most common form of osteochondroses (osteochondroses are characterized by avascular necrosis (AVN) and defective endochondral ossification of primary or secondary ossification centers).
• The etiology remains unknown, but is currently accepted that the disorder is caused by an interruption of the blood supply to the capital femoral epiphysis, causing avascular necrosis.

Clinical features of Perthes disease

• Perthes disease is common in male of age group 5-10 years.
• Pain in the hip, often radiating to knee.
• Limp (antalgic limp).
• Limitation of movement :- Abduction, internal rotation and extension are limited, therefore there is adduction, external rotation, and flexion deformity.
• Shortening of limb.
• Positive trendelenburg test.
• During the disease process, bone age is 1-3 years lower than the normal. After healing, bone age returns to normal.

Radiological investigations for Perthe’s disease

• Following radiological investigations are used :

1) X-ray hip

• Findings are :-

1. Increased medial joint space
2. Widening of femoral neck
3. Lateral extrusion (lateral subluxation)
4. Metaphyseal cysts and rarefaction of metaphysis
5. Horizontal physis with speckled calcification lateral to it
6. Fragmentation of femoral head with increased density (irregular densities in the epiphysis)

2) Bone scan

• May show a decrease uptake by femoral head.

3) MRI

• It is the investigation of choice as it can diagnose Perthes disease in early stages when X-ray is normal.
• MRI tells about :-

1. Extent of area involved
2. Sphericity of the head
3. Subluxation of the head

• Thus MRI helps better in planning for management.

Explanation:Ans. is ‘b’ i.e., Organized calcification

Seronegative spondvloarthropathies

• The seronegative spondyloarthropathies are a group of disorders that share certain clinical features and genetic associations. The word seronegative referes to the absence of rheumatoid factor in this group of disorders. The seronegative spondyloarthropathies include ‑

1. Ankylosing spondylitis
2. Reactive arthritis —› Reiter syndrome and enteritis associated arthritis
3. Psoriatic arthritis
4. Arthritis associated with inflammatory bowel disease, i.e. enteropathic arthritis

Features of seronegative spondyloarthropathies

• o Onset usually before 40 years
• Absence of RA factor
• HLA – B27 positive
• Presence of uveitis

Explanation:Ans. is.’d’ i.e., Abduction & internal rotation

Clinical features of Perthes disease

• Perthes disease is common in male of age group 5-10 years.
• Pain in the hip, often radiating to knee.
• Limp (antalgic limp)
• Limitation of movement :- Abduction, internal rotation and extension are limited, therefore there is adduction, external rotation, and flexion deformity.
• Shortening of limb.
• Positive trendelenburg test.
• During the disease process, bone age is 1-3 years lower than the normal. After healing, bone age returns to normal.