Orthopedic aspects of metabolic bone disease

Skeletal Changes in Hypoparathyroidism: X-ray to Bone Scintigraphy

Parathyroid hormone (PTH) is a key in maintaining calcium homeostasis. Decreased PTH will result in decreased bone remodeling and increased bone density. The major cause is iatrogenic injury to parathyroid gland. X-ray and dual-energy X-ray absorptiometry are used to identify the skeletal changes. Typical skeletal changes are metaphyseal sclerosis in long bones and sclerosis of vertebrae and pelvic bones. ^99mTc methylene diphosphonate scintigraphy is used to identify metabolic bone diseases. There are no typical scan findings in case of hypoparathyroidism. We like to report an interesting image of skeletal scintigraphy in case of hypoparathyroidism.

Risk factors for early revision after total hip arthroplasty

OBJECTIVE

Revision total hip arthroplasty (THA) is associated with increased cost, morbidity, and technical challenge compared to primary THA. A better understanding of the risk factors for early revision is needed to inform strategies to optimize patient outcomes.

METHODS

A total of 207,256 patients who underwent primary THA between 1997-2005 in California and New York were identified from statewide databases. Unique patient identifiers were used to identify early revision THA (<10 years from index procedure). Patient characteristics (demographics, comorbidities, insurance type, and preoperative diagnosis), community characteristics (education level, poverty, and population density), and hospital characteristics (annual THA volume, bed size, and teaching status) were evaluated using multivariable regression to determine risk factors for early revision.

RESULTS

The probabilities of undergoing early aseptic revision and early septic revision were 4% and <1% at 5 years, respectively. Women were 29% less likely than men to undergo early septic revision (P < 0.001). Patients with Medicaid and Medicare were 91% and 24%, respectively, more likely to undergo early septic revision than privately insured patients (P = 0.01 and P < 0.001, respectively). Hospitals performing <200 THAs annually had a 34% increased risk of early aseptic revision compared to hospitals performing >400 THAs annually (P < 0.001).

CONCLUSION

A number of identifiable factors, including younger age, Medicaid, and low hospital volume, increase the risk of undergoing early revision THA. Patient-level characteristics distinctly affect the risk of revision within 10 years, particularly if due to infection. Our findings reinforce the need for continued investigation of the predictors of early failure following THA.

Primary hyperparathyroidism: what every orthopedic surgeon should know

The diagnosis of hyperparathyroidism should rarely by missed by the orthopedic surgeon. When a patient presents with a pathologic fracture, routine serum calcium should be obtained. If there is evidence of elevated serum calcium or any of the pathognomonic findings of primary hyperparathyroidism on plain radiographs, total and ionized calcium and an intact parathyroid hormone levels should be obtained to make the diagnosis (Figure 5). When patients require surgical treatment for an orthopedic condition and also need surgery for hyperparathyroidism, the procedures can be safely performed simultaneously. Simultaneous parathyroidectomy corrects the underlying endocrinopathy, thereby improving the outcome of the orthopedic procedure. In addition, these procedures can easily be performed simultaneously under one anesthetic and thereby minimize cost and length of hospitalization.