Assessment of the healing of conservatively-treated scaphoid fractures using HR-pQCT.

Improving the clinical outcome of scaphoid fractures may benefit from adequate monitoring of their healing in order to for example identify complications such as scaphoid nonunion at an early stage and to adjust the treatment strategy accordingly. However, quantitative assessment of the healing process is limited with current imaging modalities. In this study, high-resolution peripheral quantitative computed tomography (HR-pQCT) was used for the first time to assess the changes in bone density, microarchitecture, and strength during the healing of conservatively-treated scaphoid fractures. Thirteen patients with a scaphoid fracture (all confirmed on HR-pQCT and eleven on CT) received an HR-pQCT scan at baseline and three, six, twelve, and 26 weeks after first presentation at the emergency department. Bone mineral density (BMD) and trabecular microarchitecture of the scaphoid bone were quantified, and failure load (FL) was estimated using micro-finite element analysis. Longitudinal changes were evaluated with linear mixed-effects models. Data of two patients were excluded due to surgical intervention after the twelve-week follow-up visit. In the eleven fully evaluable patients, the fracture line became more apparent at 3 weeks. At 6 weeks, individual trabeculae at the fracture region became more difficult to identify and distinguish from neighboring trabeculae, and this phenomenon concerned a larger region around the fracture line at 12 weeks. Quantitative assessment showed that BMD and FL were significantly lower than baseline at all follow-up visits with the largest change from baseline at 6 weeks (-13.6% and - 23.7%, respectively). BMD remained unchanged thereafter, while FL increased. Trabecular thickness decreased significantly from baseline at three (-3.9%), six (-6.7%), and twelve (-4.4%) weeks and trabecular number at six (-4.5%), twelve (-7.3%), and 26 (-7.9%) weeks. Trabecular separation was significantly higher than baseline at six (+13.3%), twelve (+19.7%), and 26 (+16.3%) weeks. To conclude, this explorative HR-pQCT study showed a substantial decrease in scaphoid BMD, Tb.Th, and FL during the first 6 weeks of healing of conservatively-treated scaphoid fractures, followed by stabilization or increase in these parameters. At 26 weeks, BMD, trabecular microarchitecture, and FL were not returned to baseline values.

Association of secondary displacement of distal radius fractures with cortical bone quality at the distal radius.

INTRODUCTION: The aim of this study was to investigate the associations of patient characteristics, bone mineral density (BMD), bone microarchitecture and calculated bone strength with secondary displacement of a DRF based on radiographic alignment parameters. MATERIALS AND METHODS: Dorsal angulation, radial inclination and ulnar variance were assessed on conventional radiographs of a cohort of 251 patients, 38 men and 213 women, to determine the anatomic position of the DRF at presentation (primary position) and during follow-up. Secondary fracture displacement was assessed in the non-operatively treated patients (N = 154) with an acceptable position, preceded (N = 97) or not preceded (N = 57) by primary reduction (baseline position). Additionally, bone microarchitecture and calculated bone strength at the contralateral distal radius and tibia were assessed by HR-pQCT in a subset of, respectively, 63 and 71 patients. OUTCOME: Characteristics of patients with and without secondary fracture displacement did not differ. In the model with adjustment for primary reduction [OR 22.00 (2.27-212.86), p = 0.008], total [OR 0.16 (95% CI 0.04-0.68), p = 0.013] and cortical [OR 0.19 (95% CI 0.05-0.80], p = 0.024] volumetric BMD (vBMD) and cortical thickness [OR 0.13 (95% CI 0.02-0.74), p = 0.021] at the distal radius were associated with secondary DRF displacement. No associations were found for other patient characteristics, such as age gender, BMD or prevalent vertebral fractures. CONCLUSIONS: In conclusion, our study indicates that besides primary reduction, cortical bone quality may be important for the risk of secondary displacement of DRFs.

Improved Detection of Scaphoid Fractures with High-Resolution Peripheral Quantitative CT Compared with Conventional CT.

BACKGROUND: Computed tomography (CT), magnetic resonance imaging, and bone scintigraphy are second-line imaging techniques that are frequently used for the evaluation of patients with a clinically suspected scaphoid fracture. However, as a result of varying diagnostic performance results, no true reference standard exists for scaphoid fracture diagnosis. We hypothesized that the use of high-resolution peripheral quantitative CT (HR-pQCT) in patients with a clinically suspected scaphoid fracture could improve scaphoid fracture detection compared with conventional CT in the clinical setting. METHODS: The present study included 91 consecutive patients (≥18 years of age) who presented to the emergency department with a clinically suspected scaphoid fracture between December 2017 and October 2018. All patients were clinically reassessed within 14 days after first presentation, followed by CT and HR-pQCT. If a scaphoid fracture was present, the fracture type was determined according to the Herbert classification system and correlation between CT and HR-pQCT was estimated with use of the Kendall W statistic or coefficient of concordance (W) (the closer to 1, the higher the correlation). RESULTS: The cohort included 45 men and 46 women with a median age of 52 years (interquartile range, 29 to 67 years). HR-pQCT revealed a scaphoid fracture in 24 patients (26%), whereas CT revealed a scaphoid fracture in 15 patients (16%). Patients with a scaphoid fracture were younger and more often male. The correlation between CT and HR-pQCT was high for scaphoid fracture type according to the Herbert classification system (W = 0.793; 95% confidence interval [CI], 0.57 to 0.91; p < 0.001) and very high for scaphoid fracture location (W = 0.955; 95%, CI 0.90 to 0.98; p < 0.001). CONCLUSIONS: In the present study, the number of patients diagnosed with a scaphoid fracture was 60% higher when using HR-pQCT as compared with CT. These findings imply that a substantial proportion of fractures-in this study, more than one-third-will be missed by the current application of CT scanning in patients with a clinically suspected scaphoid fracture. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Feasibility of High-Resolution Peripheral Quantitative Computed Tomography (HR-pQCT) in Patients with Suspected Scaphoid Fractures.

INTRODUCTION: Diagnosing scaphoid fractures remains challenging. High-resolution peripheral quantitative computed tomography (HR-pQCT) might be a potential imaging technique, but no data are available on its feasibility to scan the scaphoid bone in vivo. METHODOLOGY: Patients (≥18 years) with a clinically suspected scaphoid fracture received an HR-pQCT scan of the scaphoid bone (three 10.2-mm stacks, 61-µm voxel size) with their wrist immobilized with a cast. Scan quality assessment and bone contouring were performed using methods originally developed for HR-pQCT scans of radius and tibia. The contouring algorithm was applied on coarse hand-drawn pre-contours of the scaphoid bone, and the resulting contours (AUTO) were manually corrected (sAUTO) when visually deviating from bone margins. Standard morphologic analyses were performed on the AUTO- and sAUTO-contoured bones. RESULTS: Ninety-one patients were scanned. Two out of the first five scans were repeated due to poor scan quality (40%) based on standard quality assessment during scanning, which decreased to three out of the next 86 scans (3.5%) when using an additional thumb cast. Nevertheless, after excluding one scan with an incompletely scanned scaphoid bone, post hoc grading revealed a poor quality in 14.9% of the stacks and 32.9% of the scans in the remaining 85 patients. After excluding two scans with contouring problems due to scan quality, bone indices obtained by AUTO- and sAUTO-contouring were compared in 83 scans. All AUTO-contours were manually corrected, resulting in significant but small differences in densitometric and trabecular indices (<1.0%). CONCLUSIONS: In vivo HR-pQCT scanning of the scaphoid bone is feasible in patients with a clinically suspected scaphoid fracture when using a cast with thumb part. The proportion of poor-quality stacks is similar to radius scans, and AUTO-contouring appears appropriate in good- and poor-quality scans . Thus, HR-pQCT may be promising for diagnosis of and microarchitectural evaluations in suspected scaphoid fractures.

Comorbidities and medication use in patients with a recent clinical fracture at the Fracture Liaison Service.

In this cross-sectional study, two-thirds of Fracture Liaison Service (FLS) patients had comorbidities and medications associated with increased bone- or fall-related fracture risk. Bone-related and fall-related fracture risk (BRR and FRR) were associated with age and fracture type, but not with gender or BMD. Systematic evaluation of these factors leads to a more profound assessment in FLS care. INTRODUCTION: This study is a systematic evaluation of comorbidities and medications associated with increased fracture risk in patients aged 50-90 years with a recent fracture visiting the FLS. METHODS: In this cross-sectional cohort study, comorbidities were classified according to ICD-10 and medications according to the Anatomic Therapeutic Chemical (ATC) classification and further categorized into those associated BRR and FRR. RESULTS: Of 1282 patients (72% women; 65 ± 9 years), 53% had at least one BRR, 46% had at least one FRR, and 66% at least one BRR and/or FRR. At least one BRR, as well as at least one FRR were associated with age, BMI, and fracture type, but not with gender or BMD. The proportion of patients with only BRR (± 20%) or only FRR (± 10%) was similar among ages, gender, BMI, fracture type, and BMD. The combination of at least one BRR and at least one FRR was significantly associated with age, BMI, and major fractures, but not with gender or BMD. CONCLUSION: Comorbidities and medications associated with increased fracture risk are present in two-thirds of patients visiting the FLS. In addition, the proportion of patients having a combination of BRR and FRR increased significantly with age, BMI, and fracture severity. This indicates that systematic evaluation of these factors is important for a more profound assessment of subsequent fracture risk in FLS care.

[Diagnostic image (259). A man with knee pain]. / Diagnose in beeld (259). Een man met een pijnlijke knie.

In a 23-year-old man with knee pain a symptomatic bipartite patella was diagnosed; the small lateral fragment was surgically removed.

New model for chronic osteomyelitis with Staphylococcus aureus in sheep.

The purpose of this study was to develop a large animal model for chronic osteomyelitis, suitable for toxicologic research and therapeutic intervention studies. Osteomyelitis was induced in 52 healthy adult Texel sheep by injecting a sclerosing agent and a hemolytic strain of Staphylococcus aureus into the proximal tibial marrow cavity. Evaluation was done by clinical, radiologic, bacteriologic, and histologic parameters for 3 months. Clinical signs of infection consisted of localized soft tissue swelling, pain during the acute phase, and limping in all sheep. Radiologic features were moderate to extensive periosteal reaction, cortical lysis, mild to extensive new bone formation, and frequent development of sequestra limited to the proximal part of the tibia. Cultures were positive for the same strain of Staphylococcus aureus in all but one sheep. Histology showed chronic active inflammation, osteolysis, new woven bone formation, debris, clusters of bacteria, and surrounding granulation tissue. It was necessary to administer a single prophylactic dose of antibiotics 1 hour after surgery to prevent fatal sepsis. It was concluded that sheep are a suitable model for chronic osteomyelitis.