Archive for category: Uncategorized

Core topics in orthopaedics

Unicameral Bone Cyst (UBC)

– solitary, fluid-filled cystic lesions located in metaphysis of long bones near physis in kids & adolescents
– predominantly proximal femur & proximal humerus

Signs & Symptoms:
– usu asymptomatic
– pathologic # associated with minimal trauma

Xrays:
– radiolucent, trabeculated lesion with well-defined borders surrounding by sclerotic margin
– ‘fallen leaf’ sign in pathologic #

Histology:
– lined with loose connective tissue membrane containing small numbers of fibroblasts, giant cells & hemosiderin-laden macrophages

Treatment:
– 15% will heal after # with observation alone
– treat # as you would for most #s of that region
– once # healed, aspiration & steroid injections (x 3)
– curettage & bone grafting improves healing rate & provides mechanical support

Aneurysmal Bone Cyst (ABC)

– solitary expansile lesion located in metaphysis of long bones, flat bones & vertebrae
– presents in 2nd decade
– cysts filled with blood

Signs & Symptoms:
– pain with tenderness & swelling at the site of the lesion

Xrays:
– expansile eccentric lesion surrounded by a thinned cortex with periosteal new bone formation
– CT/MRI – characteristic ‘fluid-fluid’ level
– beware of telangiectatic osteosarcoma – has fluid-fluid levels but far more aggressive looking

Histology:
– blood spaces separated by cellular septa lacking an endothelial cell lining & containing a variety of cells such as fibroblasts, multinucleated giant cells & histiocytes & metaplastic bone
– large solid cellular areas may be seen

Treatment:
– excision, curettage & bone grafting
– cryosurgery or chemical ablation may be used

Elbow Dislocations

(Jupiter)
Posterior-(80% post./posterolat.)
-CR with sedation +/- intra-articular local-test stability-splint 1-2 weeks
Anterior-rare; risk of NV injury
Lateral
Divergent

MCQs-hip 3
adduction deformity of the hip, postural scoliosis, and a valgus deformity of the knee may develop.

– the following are blocks to reduction of CDH: inverted labrum, pulvinar, capsule (hour glass constriction), ligamentum teres, psoas tendon (causes the hourglass constriction); acetabular version does not influence reduction.

– in a 4 year old with CDH, doing a closed reduction will be very hazardous for creating AVN.

– extreme abduction will cause AVN in CDH. Extreme hyperflexion may force the heads inferiorly within the acetabulum.

– a truly congenital dislocation of the hip (present at birth) is uncommon. It is more common on the left.

– indications for Chiari include coxa magna with subluxation laterally.

– in a child with CP, innominate osteotomy is inappropriate because acetabular deficiency is not the problem, at least not initially – this is a paralytic problem. Later on, there may be acetabular deficiency more POSTERIORLY – treat with Dega osteotomy.

– the following portends a worse prognosis in Perthes: whole head involvement, females (tend to get more head involvement), loss of containment, and the presence of metaphyseal cysts.

– the Caterrall “Head at Risk” signs for Perthes include: Gage’s sign, metaphyseal cysts, horizontal physis, lateral epiphyseal calcification, lateral subluxation. In the final analysis, age of onset beyond 8, and involvement of the lateral pillar may be the worst.

– for the older DDH kid with trochanteric overgrowth because of AVN, surgical alternatives to deal with the limp and trendelenberg include either a growth arrest of the GT if young, and if older, a distal transfer of the GT.

– the classic age for Perthes is 4-9, although it can appear in kids as young as 2, and as old as 12.

– Coxa breva secondary to Perthes is a result of AVN – the neck is short, and often in varus with trochanteric overgrowth. Do no treat this with a varus osteotomy. Abductor strengthening, and distal/lateral transfer of the GT may be helpful.

– the worst of the femoral neck fractures is the transepiphyseal (Delbert I). With dislocation of the head, the AVN rate approaches 100%. Rates for the remaining probably depend mostly on displacement, although the interesting thing is that the basicervical fractures (III) have an AVN rate of nearly 25%, which is very different than in the adults.