The Young Orthopod

An osteoclast is a type of bone cell that resorbs bone tissue . This function is critical in the maintenance and repair of compact bones in the mammalian skeleton. Kolliker discovered osteoclasts in 1873 . An osteoclast is a large multinucleated cell and human osteoclasts on bone typically have five  nuclei and are about 15 0-200 μm in diameter. In bone, osteoclasts are found in pits in the bone surface, which are called resorption bays, or  Howship's Lacunae. Osteoclasts are characterized by a cytoplasm with a homogeneous, "foamy" appearance. This appearance is due to a high concentration of vesicles and vacuoles. These vacuoles include lysosomes filled with acid phophatase. This permits characterization of Osteoclasts by their staining for high expression of tartrate resistant acid phosphatase (TRAP) and cathepsin K . Osteoclast rough endoplasmic reticulum is sparse, and the Golgi complex is extensive. Osteoclasts, ...

The pelvic support osteotomy is a useful surgical procedure for the salvage of damaged hips of patients in whom arthrodesis or hip arthroplasty are not appropriate. ✫ The surgery is a double-level osteotomy of the femur : (a) The more proximal valgus-extension osteotomy is performed with the femur in maximum  adduction and at a level where the femoral shaft is seen to abut the pelvis. (b) The second, more distal , osteotomy restores the orientation of the knee and ankle joint lines in the coronal plane and also provides a focus for femoral lengthening if warranted. ✫The proximal osteotomy lateralizes and distally displaces the greater trochanter and in doing so  increases the action of the abductor muscles . ✫To this is added the elimination of any further adduction between femur and pelvis which then prevents pelvic drop during the single stance phase of gait. ✫ A successful pelvic support osteotomy Reduces limp throug...

Pavlik harness is a dynamic flexion abduction orthosis used to treat DDH ( Reduction & Maintenance ) in infants up to 6 months of age. Developed by Dr. Arnold Pavlik (C zechoslovakian Orthopaedic Surgeon) in 1944. Spontaneous reduction of dislocated hip is promoted by positioning the hip in flexion while allowing free abduction. (i.e Prevents hip Adduction and Extension ) Parts of Pavlik Harness An adjustable band encircling the lower chest ( Halter - Chest Strap ). To this band are attached pair of shoulder straps which cross posteriorly and  A pair of stirrups which embrace the legs down to the heels.  The stirrups are suspended from the encircling chest band by two adjustable straps - one passing anterior to and the other posterior to the lower limb. Indications:   Infants with DDH & who are younger than six months . Contra-Indications:  Infants with a " hip-click " but a normal physical exa...