Prevalence of thoracic scoliosis in adults 25 to 64 years of age detected during routine chest radiographs.

PURPOSE: To investigate the prevalence of thoracic scoliosis and determine the effect of both age and gender on coronal curve magnitude among asymptomatic adults aged 25-64 years old, using standing posterior-anterior chest radiographs. METHODS: This was a retrospective, cross-sectional study evaluating 500 randomly selected digital posterior-anterior chest radiographs taken at a single institution on an outpatient basis between January 2010 and December 2011. Males (n = 184) and females (n = 316) ranged in age from 25 to 64 years. Patients with symptoms of back pain; including a history of back pain, spinal instrumentation, or known pre-existing spinal disease were excluded. Radiographs were evaluated using Centricity PACS Web Diagnostic 2.1 system (General Electric Co. Fairfield, CT). Coronal Cobb angle measurements of the thoracic spine were quantified by the authors, with scoliosis defined as coronal curves greater than 10°. Curvatures were subdivided into groups: a control group with coronal curves less than 10°, curves measuring 10° to 19°, 20° to 29°, and greater than 30°. The effect of age and gender on curve magnitude was examined using Pearson correlation analysis and linear regression analysis. RESULTS: There was a 13.4 % (67 patients) prevalence of thoracic scoliosis. The prevalence among asymptomatic males was 10.9 %, while the prevalence among asymptomatic females was 14.9 %. 11.6 % demonstrated a coronal curvature between 10° and 19° (58 patients), 1.6 % between 20° and 29° (8 patients), and 0.2 % greater than 30° (1 patient). Age and gender were not found to be significant independent predictors of curve severity. CONCLUSIONS: We found a 13.4 % prevalence of thoracic scoliosis among asymptomatic adults aged 25-64 years on routine outpatient chest radiographs. 11.6 % of patients demonstrated a coronal curvature between 10° and 19°. Unlike prior studies evaluating asymptomatic thoracic curves in elderly patients, age and gender did not significantly affect curve magnitude in our younger cohort. These data may provide a reference point to help clinicians counsel asymptomatic patients diagnosed with thoracic scoliosis on routine chest radiographs.

Can the Visibility of Both Prosthetic Posterior Femoral Condyles on a Postoperative Radiograph Assure that Limb Rotation Is Appropriate to Allow Accurate Measurement of the Anatomic Knee Axis?

BACKGROUND: To better define radiographic parameters for a true anterior-posterior (AP) knee radiograph after total knee arthroplasty, we cataloged the radiographic appearance of 7 different designs of commercially available femoral components at various points of rotation to correlate the visibility of the prosthetic posterior femoral condyles (PPFCs) with the amount of rotation of the femoral component, and hence, the limb. METHODS: AP radiographs of 7 left-sided, cruciate-retaining femoral trial components were obtained at 5° increments of rotation from 20° internal rotation (IR) to 20° external rotation (ER). Rotational profiles were cataloged based on the visibility of either or both of the PPFCs. RESULTS: Three categories of femoral component rotation profiles were noted, based on the visibility of the PPFC: overt ER with only the medial PFC visible at greater than 10° ER, overt IR with only the lateral PFC visible at greater than 20° IR, and near-neutral rotation with both medial and lateral PPFCs visible between 5° ER and 15° IR. CONCLUSION: An acceptable AP radiograph to measure the anatomic knee axis after total knee arthroplasty is one where both the medial and lateral PPFCs are visible on either side of the trochlear flange.

The Effect of Patellar Thickness on Intraoperative Knee Flexion and Patellar Tracking in Patients With Arthrofibrosis Undergoing Total Knee Arthroplasty.

BACKGROUND: We evaluated the intraoperative effect of patellar thickness on intraoperative passive knee flexion and patellar tracking during total knee arthroplasty (TKA) in patients with preoperative arthrofibrosis and compared them to patients with normal preoperative range of motion (ROM) documented in a prior study. METHODS: Routine posterior cruciate ligament-retaining TKA was performed in a total of 34 knees, 23 with normal ROM and 11 with arthrofibrosis, defined as ≤100° of passive knee flexion against gravity under anesthesia. Once clinical balance and congruent patellar tracking were established, custom trial patellar components thicker than the standard trial by 2-mm increments (2-8 mm) were sequentially placed and trialed. Passive flexion against gravity was recorded using digital photograph goniometry. Gross mechanics of patellofemoral tracking were visually assessed. RESULTS: On average, passive knee flexion decreased 2° for every 2-mm increment of patellar thickness (P < .0001), which was similar to patients with normal preoperative ROM. In addition, increased patellar thickness had no gross effect on patellar subluxation and tilt in patients with arthrofibrosis as well as those with normal ROM. CONCLUSIONS: Patellar thickness had a modest effect on intraoperative passive flexion and no effect on patellar tracking in patients with arthrofibrosis undergoing TKA. There was no marked difference in intraoperative flexion and patellar tracking between patients with arthrofibrosis and patients with normal preoperative ROM.

Patient education before hip or knee arthroplasty lowers length of stay.

From April 2006 to May 2007, 261 patients undergoing primary unilateral total hip arthroplasty or total knee arthroplasty were offered voluntary participation in a one-on-one preoperative educational program. Length of stay (LOS) and inpatient data were monitored and recorded, prospectively. Education participants enjoyed a significantly shorter LOS than nonparticipants for both total hip arthroplasty (3.1 +/- 0.8 days vs 3.9 +/- 1.4 days; P = .0001) and total knee arthroplasty (3.1 +/- 0.9 days vs 4.1 +/- 1.9 days; P = .001).

ERK signaling regulates macrophage colony-stimulating factor expression induced by titanium particles in MC3T3.E1 murine calvarial preosteoblastic cells.

Periprosthetic osteolysis poses a significant clinical problem for patients who have undergone total joint arthroplastic surgeries. It has been widely recognized that there is a strong correlation between wear particles from orthopedic implants and osteolysis. However, the molecular mechanism underlying osteolysis still remains unclear. Although wear particles interact with a mixed cellular environment, namely macrophages and immune cells, osteoblasts compose the majority of the cell population surrounding orthopedic implants. Osteoblasts are also one of the major sources of receptor activator of nuclear factor-kappa beta (NF-kappaB) ligand (RANKL), a factor necessary for osteoclastogenesis. However, macrophage colony-stimulating factor (M-CSF), another cytokine responsible for preosteoclast proliferation, must also be present with RANKL for osteoclastogenesis to occur. The purpose of our study is to determine the signal transduction pathway by which titanium (Ti) particles, a metallic component of many orthopedic implants, induce M-CSF expression in MC3T3.E1 murine calvarial preosteoblastic cells. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme- linked immunosorbent assay (ELISA), our study demonstrated that submicron-sized Ti particles induce M-CSF expression via the extracellular signal-regulated kinase (ERK) pathway in a dose-dependent manner. Moreover, inhibition studies showed that a specific ERK inhibitor, PD98059, significantly downregulated M-CSF production. Our results support the hypothesis that submicron-sized Ti particles can induce M-CSF expression in osteoblasts and thus may have a significant role in contributing to the onset of periprosthetic osteolysis.

Hypovitaminosis D in patients scheduled to undergo orthopaedic surgery: a single-center analysis.

BACKGROUND: Vitamin D is essential for optimal bone health and muscle function. An alarmingly high rate of vitamin-D deficiency in the general population has been reported recently. The purpose of the present study was to characterize the extent of low serum levels of vitamin D among orthopaedic surgery patients. METHODS: We performed a retrospective chart review of 723 patients who were scheduled for orthopaedic surgery between January 2007 and March 2008. Preoperative serum 25-hydroxyvitamin D (25[OH]D) levels were measured. The prevalence of normal (≥32 ng/mL), insufficient (<32 ng/mL), and deficient (<20 ng/mL) vitamin-D levels was determined. Logistic regression was used to assess risk factors for insufficient (<32 ng/mL) 25(OH)D levels. RESULTS: Overall, 43% of all patients had insufficient serum vitamin-D levels, and, of these, 40% had deficient levels. Among the orthopaedic services, the highest rates of low serum vitamin-D levels were seen in the trauma and sports services, in which the rates of abnormal (insufficient and deficient) vitamin-D levels were 66% and 52%, respectively. The lowest rate of abnormal vitamin-D levels was seen in the metabolic bone disease service. Patients between the ages of fifty-one and seventy years were 35% less likely to have low vitamin-D levels than patients between the ages of eighteen and fifty years (p = 0.018). The prevalence of low vitamin-D levels was significantly higher in men (p = 0.006). Individuals with darker skin tones (blacks and Hispanics) were 5.5 times more likely to have low vitamin-D levels when compared with those with lighter skin tones (whites and Asians) (p < 0.001). CONCLUSIONS: The prevalence of low serum levels of vitamin D among patients undergoing orthopaedic surgery is very common. Given the importance of vitamin D in musculoskeletal health, such low levels may negatively impact patient outcomes.

Targeting extracellular signal-regulated kinase (ERK) signaling has therapeutic implications for inflammatory osteolysis.

The extracellular signal-regulated kinase 1/2 (ERK) pathway, part of the mitogen-activated protein kinase (MAPK) family, is well-known for its role in cell differentiation and proliferation. In the context of osteoclastogenesis, macrophage colony stimulating factor (M-CSF) is an upstream activator of ERK signals for the survival of osteoclast precursors prior to their differentiation into multinucleated osteoclasts. In this study, we demonstrate by using both in vivo and in vitro models that the ERK signaling pathway involves an inflammatory response of various cells mediating osteolysis. Osteoblasts exhibit innate immune response by expressing M-CSF in response to lipopolysaccharide (LPS). LPS induced M-CSF expression is mediated by ERK. The inhibition of ERK signaling attenuated the inflammatory response to LPS both in vivo and in vitro. Thus, the ERK pathway may be a potentially important therapeutic target in the treatment of inflammatory osteolysis.

Selection and development of preclinical models in fracture-healing research.

Animal fracture models have been extensively applied to preclinical research as a platform to identify and characterize normal and abnormal physiological processes and to develop specific maneuvers that alter the biology and biomechanics being examined. The choice of animal model employed in a study bears a direct relationship to the specific intervention being analyzed. The animal models employed should be described clearly, control-group data should be established, and reproducibility should be defined from experiment to experiment and from institution to institution so that quantitative and qualitative outcomes can be reliably compared and contrasted to other related studies.