Reliability and Validity of the Femorotibial Mechanical Axis Angle in Primary Total Knee Arthroplasty: Navigation versus Weight Bearing or Supine Whole Leg Radiographs

PURPOSE: To evaluate the reliability and validity of the femorotibial mechanical axis angle from radiographs in the weight bearing (WB) and supine positions compared with navigation-measured values. MATERIALS AND METHODS: Sixty-eight cases of navigation-assisted total knee arthroplasty (TKA) were included. The pre- and postoperative whole leg radiographs (WLRs) in WB and supine positions were compared with the initial and final navigation values. RESULTS: The mean mechanical axis angle from the preoperative WBWLR and navigation were not statistically different (p=0.079) and were correlated strongly with each other (intraclass correlation [ICC], 0.818). However, on postoperative measurements, although the WBWLR and navigation values were not different (p=0.098), they were not correlated with each other (ICC, 0.093). The standard error of measurement was 1.8°±3.6° for the preoperative WBWLR and 2.5°±4.8° for the postoperative WBWLR. The validity that was determined by the Bland-Altman plot was not acceptable for both pre- and postoperative measurements. CONCLUSIONS: The preoperative WBWLR could provide accurate but not precise measurement value of the femorotibial mechanical axis angle for navigation-assisted TKA, and postoperative measurements in navigation were not comparable with radiographic measurements. The lack of agreement was found between the radiographic and navigation measurements of the coronal alignment regardless of pre- or postoperative evaluation although the accuracy was found acceptable. LEVEL OF EVIDENCE: Level 4

Erratum to: Vitamin D Deficiency Is Highly Concomitant but Not Strong Risk Factor for Mortality in Patients Aged 50 Year and Older with Hip Fracture

In this article, The author's name and Table 1 should be corrected.

Vitamin D Deficiency Is Highly Concomitant but Not Strong Risk Factor for Mortality in Patients Aged 50 Year and Older with Hip Fracture

BACKGROUND: The purpose of this study was to ascertain the prevalence of vitamin D deficiency and risk factors associated with mortality in patients > or =50-year-of-age with hip fractures. METHODS: A total of 489 patients > or =50-year-of-age who sustained a hip fracture from January 2010 to October 2014 were followed-up for a minimum of 1 year. Clinical and radiological outcomes were evaluated including prevalence of vitamin D deficiency. Crude mortality rates were calculated, and the effects of different risk factors on mortality were assessed. RESULTS: Vitamin D deficiency was present in 76.5% of cases (n=237). The prevalence of vitamin D insufficiency was 12.3%, and only 11.2% of patients had normal vitamin D levels. Accumulated mortality was 11% (54 patients) at 1 year. A univariate analysis showed that vitamin D deficiency (P=0.012), age (P<0.001), BMI (P<0.001), type of management (P<0.001), American Society of Anesthesiologists (ASA) score (P=0.009), pre-fracture ambulatory status (P<0.001), and osteoporosis (P<0.001) were associated with mortality. A multivariate analysis performed using a Cox proportional hazards model demonstrated that ASA score (P=0.001) and pre-fracture ambulatory status (P=0.011) were independently associated with mortality after hip fracture. CONCLUSIONS: We did not find a relationship between serum 25-hydroxy-vitamin D levels and mortality after hip fracture, although we observed a high prevalence of vitamin D deficiency and a significant association with mortality in the univariate analysis.