Reliability of Bone Scintigraphy for Suspected Scaphoid Fractures

The interobserver reliability of the diagnosis and classification of scaphoid fractures using high-resolution peripheral quantitative CT

Aims

Besides conventional radiographs, the use of MRI, CT, and bone scintigraphy is frequent in the diagnosis of a fracture of the scaphoid. However, which techniques give the best results remain unknown. The investigation of a new imaging technique initially requires an analysis of its precision. The primary aim of this study was to investigate the interobserver agreement of high-resolution peripheral quantitative CT (HR-pQCT) in the diagnosis of a scaphoid fracture. A secondary aim was to investigate the interobserver agreement for the presence of other fractures and for the classification of scaphoid fracture.

Methods

Two radiologists and two orthopaedic trauma surgeons evaluated HR-pQCT scans of 31 patients with a clinically-suspected scaphoid fracture. The observers were asked to determine the presence of a scaphoid or other fracture and to classify the scaphoid fracture based on the Herbert classification system. Fleiss kappa statistics were used to calculate the interobserver agreement for the diagnosis of a fracture. Intraclass correlation coefficients (ICCs) were used to assess the agreement for the classification of scaphoid fracture.

Results

A total of nine (29%) scaphoid fractures and 12 (39%) other fractures were diagnosed in 20 patients (65%) using HR-pQCT across the four observers. The interobserver agreement was 91% for the identification of a scaphoid fracture (95% confidence interval (CI) 0.76 to 1.00) and 80% for other fractures (95% CI 0.72 to 0.87). The mean ICC for the classification of a scaphoid fracture in the seven patients diagnosed with scaphoid fracture by all four observers was 73% (95% CI 0.42 to 0.94).

Conclusion

We conclude that the diagnosis of scaphoid and other fractures is reliable when using HR-pQCT in patients with a clinically-suspected fracture. Cite this article: Bone Joint J 2020;102-B(4):478–484.

A Scoring System to Demonstrate the Risk for Bone Injury in Patients with Clinically Suspected or Occult Scaphoid Fracture

BACKGROUND

It is important to diagnose a scaphoid fracture accurately and start the correct treatment in the shortest time possible. However, the fracture of bone may not be visible on x-ray. In such cases, patients are clinically diagnosed with suspected or occult scaphoid fractures. The aim of this study was to define a scoring system based on physical examination to demonstrate the risk for bone injury in patients with clinically suspected and occult scaphoid fractures with negative radiographs and anatomical snuff box tenderness and to decrease the costs and workforce loss due to unnecessary treatment and magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Patients were initially evaluated by the attendant orthopedic physician in the emergency service with X-ray of the wrist, and ten wrist physical examination techniques were used. The X-rays of patients were evaluated by three orthopedic surgeons. Finally sixty patients, who were diagnosed as having no fracture by all three orthopedic surgeon, were included in the study. The wrists of these patients were evaluated with MRI.

RESULTS

There were 46 male (77%) and 14 female (23%) patients with a mean age of 21.5 years (range 7-61 years). About 3.3% had triquetrum fracture, 15% had bone edema in the scaphoid and radius, 18.3% had distal radius fracture, 31.6% had scaphoid fracture, and 31.8% had no bone injury. A scoring system was also proposed. It can be predicted that in the physical examination of the wrist if the total score is higher than 6.5, the probability of fracture is 2.87 (positive likelihood ratio) fold compared to scores below 6.5.

CONCLUSIONS

Proposal of this new scoring system was thought to be useful for predicting the risk for bone injury in patients with clinically suspected scaphoid fractures and making decision regarding therapeutic options.

Interobserver variability among radiologists for diagnosis of scaphoid fractures by computed tomography

PURPOSE

To determine the interobserver variability among radiologists for computed tomography (CT) diagnosis of scaphoid fractures.

METHODS

Four specialized musculoskeletal radiologists evaluated the CT scans of 150 consecutive patients who were clinically suspected of having sustained a scaphoid fracture but whose scaphoid-specific radiographs were normal. The radiologists were asked to determine the presence or absence of a scaphoid fracture and to localize the fracture. Interobserver agreement was calculated using the kappa statistic.

RESULTS

The radiologists diagnosed between 11 (7%) and 22 (15%) scaphoid fractures; the kappa value was 0.51.

CONCLUSION

Agreement on the presence of a scaphoid fracture and its location on a CT scan was moderate among the 4 radiologists. This finding raises the question as to whether scaphoid fractures could be under- or overdiagnosed in daily practice when CT is used to exclude or confirm a fracture. This should be kept in mind when interpreting clinical and radiological results in patients with suspected scaphoid fractures.

Clinical prediction rule for suspected scaphoid fractures: A prospective cohort study

BACKGROUND

The low prevalence of true fractures amongst suspected fractures magnifies the shortcomings of the diagnostic tests used to triage suspected scaphoid fractures.

PURPOSE

The objective was to develop a clinical prediction rule that would yield a subset of patients who were more likely to have a scaphoid fracture than others who lacked the subset criteria.

METHODS

Seventy-eight consecutive patients diagnosed with a suspected scaphoid fracture were included. Standardised patient history, physical examination, range of motion (ROM) and strength measurements were studied. The reference standard for a true fracture was based on the results of magnetic resonance imaging, bone scintigraphy, follow-up radiographs and examination.

RESULTS

Analysis revealed three significant independent predictors: extension <50%, supination strength ≤ 10% and the presence of a previous fracture.

CONCLUSION

Clinical prediction rules have the potential to increase the prevalence of true fractures amongst patients with suspected scaphoid fractures, which can increase the diagnostic performance characteristics of radiological diagnostic tests used for triage.