Are radiographic indices reliable indicators for quantitative bone mineral density and vitamin D status after femoral neck fractures? A retrospective study in 112 elderly patients

For older women, the majority of hip fragility fractures and radiographic vertebral fragility fractures occur among the densitometrically osteoporotic population: a literature analysis

It has been frequently cited that 'the majority of fragility fractures (FF) occur at non-osteoporotic bone mineral density (BMD)'. For the reports with T-score measured around the time of a hip fracture, we conducted a systematic literature search in December 2022, and resulted in 10 studies with five for Caucasian women and five for East Asian women. Femoral neck (FN) T-score was reported in five Caucasian studies and three East Asian studies, three of five Caucasian studies had a mean T-score ≤-2.5, and one study had the majority of their patients measuring a mean T-score ≤-2.5. All three East Asian studies reported a mean FN T-score ≤-2.7. Total hip T-score was reported in two Caucasian studies and three East Asian studies, the two Caucasian studies both had a mean T-score ≤-2.5, and all three East Asian studies had a mean T-score ≤-2.6. A new literature search conducted in April 2024 results in additional three studies, with results being consistent with the data described above. A trend was noted that 'younger' patients suffer from hip fractures at a 'higher' T-score. For the highly cited articles where the notion the majority of FF occur at non-osteoporotic BMD was derived from, authors reported prospective epidemiological studies where BMD was not measured at the timepoint of hip fracture, instead, BMD was measured at the study baseline. These epidemiological studies suggest that >50% of hip fractures likely occur in women with an osteoporotic FN or hip T-score. However, a pattern was seen that older men suffer from hip fracture at a notably higher T-score than older women. For the cases of radiographic vertebral FF, despite varying criteria being used to classify these FFs, the majority of female patients had spine densitometric osteoporosis. Literature shows, compared with the cases of hip fracture, distal forearm fracture occurs at a 'younger' age and 'higher' BMD, suggesting distal forearm fracture is more likely associated with a 'higher' trauma energy level.

Diagnostic Value of Radiographic Singh Index Compared to Dual-Energy X-Ray Absorptiometry Scan in Diagnosing Osteoporosis: A Systematic Review

Objectives

Since various medications can control the rate of fractures and subsequent complications of osteoporosis, the early detection of the disease is crucial. This systematic study aimed to compare the diagnostic accuracy of Singh index (SI) with dual-energy X-ray absorptiometry (DEXA) as a benchmark standard for diagnosing osteoporosis.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) were utilized in the current study. A detailed search was carried out using PubMed and Scopus from inception to 30 May 2022. Examining quality of the studies was performed by the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2).

Results

A total of 22 studies were included. In general, 50% of the studies considered SI a poor screening tool for detecting osteoporosis due to a negligible inter-observer agreement between SI and DEXA or a poor correlation of SI with the bone mineral density (BMD) category or DEXA T-score. A moderate inter-observer agreement was reported for SI in 5 (55.6%) studies. Among the studies assessing the sensitivity and specificity of SI compared to DEXA (n=13), six studies estimated a low sensitivity for SI.

Conclusion

While there is supporting evidence indicating the potential usefulness of SI for predicting femoral neck fractures in individuals with suspected osteoporosis, numerous studies challenge its reliability and diagnostic value as a screening tool for identifying femoral neck osteoporosis. Further primary studies are required to verify the effectiveness of the SI index in identifying populations at risk of osteoporosis.

Plain radiographic indices are reliable indicators for quantitative bone mineral density in male and female patients before total hip arthroplasty

Osteoporosis is underdiagnosed in patients undergoing total hip arthroplasty (THA). Bone mineral density measurement by dual-energy X-ray absorptiometry (DXA) is the gold standard, but indices on plain hip radiographs also seemed to be reliable screening tools in female or Asian ethnicities in previous studies. Given the lack of knowledge about male patients and Caucasian ethnicities, this study was conducted to evaluate plane hip radiographic indices as a screening tool for osteopenia and osteoporosis in Caucasian female and also male patients before undergoing THA. A retrospective analysis of 216 elderly patients with pre-existing DXA before hip arthroplasty was performed and four indices were calculated on plain hip radiographs: Canal-Flare-Index (CFI), Canal-Calcar-Ratio (CCR), Canal-Bone-Ratio (CBR) 7 and 10 cm below the lesser trochanter. They were correlated with femoral neck DXA T-scores by Pearson's correlation and intraclass correlation coefficient, and a ROC analysis was performed. A total of 216 patients (49.5% male) were included. CBR-7 and -10 were highly correlated (p < 0.001) with femoral neck T-score in males (Pearson's correlation CBR-7 r = - 0.60, CBR-10 r = - 0.55) and females (r = - 0.74, r = - 0.77). CBR-7 and -10 also showed good diagnostic accuracy for osteoporosis in the ROC analysis in males (CBR-7: AUC = 0.75, threshold = 0.51; CBR-10: 0.63; 0.50) and females (CBR-7: AUC = 0.87, threshold = 0.55; CBR-10: 0.90; 0.54). Indices such as the Canal Bone Ratio (CBR) 7 or 10 cm below the lesser trochanter on plain hip radiographs are a good screening tool for osteopenia and osteoporosis on plain hip radiographs and can be used to initiate further diagnostics like the gold standard DXA. They differ between male and female patients.

Use of Bone Health Evaluation in Orthopedic Surgery: 2019 ISCD Official Position

This position development conference (PDC) Task Force examined the assessment of bone status in orthopedic surgery patients. Key questions included which orthopedic surgery patients should be evaluated for poor bone health prior to surgery and which subsets of patients are at high risk for poor bone health and adverse outcomes. Second, the reliability and validity of using bone densitometry techniques and measurement of specific geometries around the hip and knee before and after arthroplasty was determined. Finally, the use of computed tomography (CT) attenuation coefficients (Hounsfield units) to estimate bone quality at anatomic locations where orthopedic surgery is performed including femur, tibia, shoulder, wrist, and ankle were reviewed. The literature review identified 665 articles of which 198 met inclusion exclusion criteria and were selected based on reporting of methodology, reliability, or validity results. We recommend that the orthopedic surgeon be aware of established ISCD guidelines for determining who should have additional screening for osteoporosis. Patients with inflammatory arthritis, chronic corticosteroid use, chronic renal disease, and those with history of fracture after age 50 are at high risk of osteoporosis and adverse events from surgery and should have dual energy X-ray absorptiometry (DXA) screening before surgery. In addition to standard DXA, bone mineral density (BMD) measurement along the femur and proximal tibia is reliable and valid around implants and can provide valuable information regarding bone remodeling and identification of loosening. Attention to positioning, selection of regions of interest, and use of special techniques and software is required. Plain radiographs and CT provide simple, reliable methods to classify the shape of the proximal femur and to predict osteoporosis; these include the Dorr Classification, Cortical Index, and critical thickness. Correlation of these indices to central BMD is moderate to good. Many patients undergoing orthopedic surgery have had preoperative CT which can be utilized to assess regional quality of bone. The simplest method available on most picture archiving and communications systems is to simply measure a regions of interest and determine the mean Hounsfield units. This method has excellent reliability throughout the skeleton and has moderate correlation to DXA based on BMD. The prediction of outcome and correlation to mechanical strength of fixation of a screw or implant is unknown.

Ultimate fracture load of cadaver proximal humeri correlates more strongly with mean combined cortical thickness than with areal cortical index, DEXA density, or canal-to-calcar ratio

Objectives

This investigation sought to advance the work published in our prior biomechanical study (Journal of Orthopaedic Research, 2016). We specifically sought to determine whether there are additional easy-to-measure parameters on plain radiographs of the proximal humerus that correlate more strongly with ultimate fracture load, and whether a parameter resembling the Dorr strength/quality characterisation of proximal femurs can be applied to humeri.

Materials and Methods

A total of 33 adult humeri were used from a previous study where we quantified bone mineral density of the proximal humerus using radiographs and dual-energy x-ray absorptiometry (DEXA), and regional mean cortical thickness and cortical index using radiographs. The bones were fractured in a simulated backwards fall with the humeral head loaded at 2 mm/second via a frustum angled at 30° from the long axis of the bone. Correlations were assessed with ultimate fracture load and these new parameters: cortical index expressed in areas (“areal cortical index”) of larger regions of the diaphysis; the canal-to-calcar ratio used analogous to its application in proximal femurs; and the recently described medial cortical ratio.

Results

The three new parameters showed the following correlations with ultimate fracture load: areal cortical index (r = 0.56, p < 0.001); canal-to-calcar ratio (r = 0.38, p = 0.03); and medial cortical ratio (r = 0.49, p < 0.005). These correlations were weaker when compared with those that we previously reported: mean cortical thickness of the proximal diaphysis versus ultimate fracture load (r = 0.71; p < 0.001); and mean density in the central humeral head versus ultimate fracture load (r = 0.70; p < 0.001).

Conclusion

Simple-to-measure radiographic parameters of the proximal humerus reported previously are more useful in predicting ultimate fracture load than are areal cortical index, canal-to-calcar ratio, and medial cortical ratio.

Cite this article: J. G. Skedros, C. S. Mears, W. Z. Burkhead. Ultimate fracture load of cadaver proximal humeri correlates more strongly with mean combined cortical thickness than with areal cortical index, DEXA density, or canal-to-calcar ratio. Bone Joint Res 2017;6:1–7. DOI: 10.1302/2046-3758.61.BJR-2016-0145.R1