Comparative evaluation of postreduction intra-articular distal radial fractures by radiographs and multidetector computed tomography

Comparison of Low-Dose Computed Tomography Versus Conventional-Dose Computed Tomography in the Evaluation of Distal Radius Fractures

BACKGROUND

Distal radius fractures (DRFs) are common upper extremity fractures and often require surgical fixation when they are intraarticular. Preoperative computed tomography (CT) has emerged as a surgical planning tool to evaluate intraarticular DRFs. Although CT affords additional details, patients receive higher radiation doses than standard radiographs. We aim to develop a low-dose CT (LDCT) protocol, relative to the institutional standard-dose CT wrist for intraarticular DRFs although providing adequate detail for surgical decision-making.

METHODS

A single-institution prospective study was conducted on patients with intraarticular DRFs who underwent closed reduction and below-elbow splinting who otherwise would undergo wrist CT. Observations were defined as total measurements taken, with each view undergoing 44 measurements. Patients underwent 2 scans with a standard dose and a 10× dose reduction. Articular step and gap measurements were recorded in the sagittal and coronal images.

RESULTS

A total of 11 patients were enrolled (7 women and 4 men). The mean age was 55 years (SD = 20.1). There were a total of 4 reviewers: 1 attending surgeon, 2 resident physicians, and 1 student. When comparing LDCT and conventional-dose CT (CDCT), there were no significant differences in step and gap measurements across all reviewers.

CONCLUSION

This study demonstrated that LDCT provides comparable imaging quality for surgical planning as a CDCT without significant diagnostic decay in the setting of DRFs. This comes with the added benefit of a 10-fold reduction in radiation exposure. These results suggest that LDCT is an opportunity to reduce effective radiation in patients although providing beneficial preoperative imaging.

Methods of assessing intra-articular distal radial fractures

We systematically reviewed current measurement methods and the imaging modality of choice for intra-articular distal radial fractures. There is no current reference standard measurement method and a lack of evidence comparing them. Radiographs underestimate displacement, with most papers favouring CT.

MDCT evaluation of distal radius fractures and their association with carpal and distal ulnar fractures

PURPOSE

The purpose of this study was to evaluate the characteristics of distal radius fractures (DRFs) in patients undergoing multi-detector computed tomography (MDCT) and their association with carpal and distal ulnar fractures.

METHODS

This retrospective study analyzed 120 patients, who underwent MDCT for evaluation of DRFs. Two radiologists independently evaluated the data for various fracture characteristics and for associated carpal and distal ulnar fractures.

RESULTS

Out of 120 DRFs, 74 were complete articular, 40 were partial articular and only 6 were extra-articular. Displacement was present in 99 fractures and intra-articular step off was present in 73 fractures. A total of 81 carpal bone fractures were identified in 46 (38.3%) patients, with more than one carpal bone fracture in 21 patients. Distal ulnar fractures were detected in 79 patients (65.8%), out of which 67 involved the ulnar styloid. DRFs with intra-articular step off were more frequently associated with carpal bone fracture (p value: 0.021), while displaced DRFs were more frequently associated with distal ulnar fracture (p value <0.001). Interobserver agreement for detection of carpal bone fractures (κ = 0.807) and distal ulnar fractures (κ = 0.923) was excellent.

CONCLUSION

Majority of DRFs in patients referred for MDCT were complete articular with high incidence of displacement and intra-articular step off. Associated carpal bone and distal ulna fractures were not uncommon.

Comparison of cone beam computed tomography and plane radiographs of radial fractures as a basis for radiographical measurements

BACKGROUND

The purpose of this study was to determine whether radiological measurements of radial fracture position made in cone beam computed tomography (CBCT) projection images are comparable to those made on traditional radiographs and could potentially substitute them.

METHODS

Sixteen patients with fractures of the distal radius referred for radiographs were recruited for an additional CBCT scan which was performed immediately afterwards. Projection images and volumetric data were saved from the CBCT scans. Measurements of ulnar variance, radial inclination and volar tilt were made from all three sets of images.

RESULTS

Agreement of projection image based measurements with radiographs was nearly as good as as the agreement of cross sectional image measurements with radiographs. The average difference between the results for projection images and radiographs were -1.2 mm (SD 1.9 mm), for radial inclination 0.7° (SD 2.9°) and for volar tilt 1.9° (SD 5.6°).

CONCLUSION

Differences between radiological measurements between the modalities studied are small and projection images could be used for the assessment of distal radial fractures.

Computed Tomography Evaluation of Distal Screw Penetration in Volar Locking Plate Fixation for Intra-Articular Distal Radius Fractures

PURPOSE

Volar locking plate fixation for distal radius fractures (DRFs) is a technically demanding procedure with a risk of distal screw penetration through the dorsal cortex or the articular surface. This study aimed to investigate the incidence and details of distal screw penetration after volar locking plate fixation for intra-articular DRFs using a CT scan and to evaluate the relationship between the incidence of screw penetration and fracture comminution severity and the clinical complications of screw penetration.

METHODS

This was a retrospective case series of 91 adult patients (mean age, 63 years; 27 men) who underwent volar locking plate fixation for intra-articular DRFs from 2015 to 2018. The positioning of the distal screws was evaluated using a postoperative CT scan, and radiological outcomes were compared between the AO C1 and C3 groups. At the final follow-up, tendon rupture and arthritis severity were assessed as clinical complications of dorsal and intra-articular screw penetration.

RESULTS

Distal screw penetration was observed in 44 wrists (48%), dorsal cortex screw penetration in 34, intra-articular screw penetration in 13, and both dorsal cortex and intra-articular screw penetration in three. The incidence of intra-articular screw penetration was significantly higher in the C3 group than in the C1 group. No tendon rupture was observed. Multivariable analysis revealed that intra-articular screw penetration was significantly related to high severity of arthritis.

CONCLUSIONS

Approximately half of the study patients with intra-articular DRFs had distal screw penetration. The incidence of intra-articular screw penetration was associated with the severity of fracture comminution, and the intra-articular screw penetration was associated with the incidence of early radiocarpal arthritis. Intra-articularly penetrating screws should be replaced as soon as they are discovered, regardless of the length of penetrated screw or absence of patients' subjective symptoms.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Cone-beam computed tomography in the treatment of distal radius fractures

Cone-beam computed tomography (CBCT) is a relatively new imaging technique in hand surgery. Being the most common fractures in adults, distal radius fractures are of special importance not only to hand surgeons. The quantity alone calls for fast, efficient and reliable diagnostic procedures. Surgical techniques and possibilities are progressing, especially regarding intra-articular fracture patterns. The demand for exact anatomic reduction is high. There is an overall consensus regarding the indication for preoperative three-dimensional imaging and it is frequently used. Typically, it is obtained by multi-detector computed tomography (MDCT). Postoperative diagnostic procedures are usually limited to plain x-rays. Commonly accepted recommendations regarding postoperative 3D imaging are not yet established. There is a lack of relevant literature. In case of an indication for a postoperative CT scan, it is generally also obtained by MDCT. CBCT for the wrist is not widely used as yet. This review focuses on the potential role of CBCT in the perioperative management of distal radius fractures. CBCT allows for high-resolution imaging with a potentially lower radiation dose compared with MDCT, both with and without implants. It is easily available and can be operated independently, thus being time-efficient and making daily practice easier. Due to its many advantages, CBCT is a recommendable alternative to MDCT in the perioperative management of distal radius fractures.

Are Radiographic Characteristics Associated With Outcome in Surgically Treated Distal Radius Fractures?

PURPOSE

Evidence to date shows that distal radius fracture displacement measured on radiographs does not correlate with patient-reported outcomes. Quantitative 3-dimensional computed tomography (CT) (Q3DCT) potentially captures fracture displacement more accurately. We aimed to assess the independent association between radiographic, CT, and Q3DCT measures of residual displacement and change in disability, quality of life, range of motion (ROM), and grip strength 12 weeks and 1 year after volar plating of intra-articular distal radius fractures.

METHODS

We performed a secondary analysis of data from a prospective multicenter trial. Seventy-one patients underwent volar plating of their AO Foundation/Orthopaedic Trauma Association type B or C distal radius fracture and were available at 12 weeks; 67 (94%) were available at 1 year. We recorded demographics, postoperative periapical radiographs (radial height, ulnarward inclination, ulnar variance, gap, and step off), lateral radiographs (palmar tilt, scapholunate angle, teardrop angle, and anteroposterior distance), postoperative CT scans (gap [coronal, sagittal and axial]) and step off [sagittal and coronal]), and in 3-dimensional models (number of articular fragments, mean fragment articular surface area, 3-dimensional fragment displacement, and gap surface area). Radiographs and CT scans were obtained within 10 working days after fracture fixation. Outcome measures were change in Patient-Rated Wrist Evaluation (PRWE) scores, EuroQol Group 5-Dimension questionnaire (EQ5D) results, grip strength, and composite wrist ROM at 12 weeks and 1 year compared to preinjury level.

RESULTS

At 1 year, greater recovery in PRWE scores was independently associated with older age. Greater recovery in composite ROM at 1 year was associated with injury to the dominant side and less step-off on posteroanterior radiographs.

CONCLUSIONS

Less posteroanterior step-off was associated with a small improvement in composite wrist ROM at 1 year. This should be considered when counseling patients on the risks and benefits of surgical treatment when radiographic and CT measures of displacement fall within the range found in this study, and in older, low-demand patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

How Reliable Are Digital Radiographs for Evaluating Intra-articular Displacement in Ankle Epiphyseal Fractures: Can Computed Tomography Be Eliminated?

BACKGROUND

The amount of intra-articular displacement of the fracture is the main issue when deciding the treatment method between conservative or surgical means in intra-articular fractures. In this study, we aimed to determine the intraobserver and interobserver reliability of measuring intra-articular displacement and to compare the digital radiographic and computed tomographic (CT) evaluations in distal tibia intra-articular epiphyseal fractures.

METHODS

Thirty-seven patients with digital radiography and CT scans were included in the study. Four sets were prepared with these images. Two of four sets were prepared as ankle radiographs, and the other two sets were prepared with CT scan views. Five observers were asked to measure the intra-articular displacement of the fractures in millimeters and also to make a decision between displacement amounts over or under 2 mm. Intraclass correlation coefficient scores were calculated for evaluation of intraobserver reliability, and Fleiss kappa values were calculated for interobserver reliability evaluations. A value greater than 0.75 was accepted as excellent agreement; 0.75 to 0.40 as intermediate to good agreement; and below 0.40 as poor agreement.

RESULTS

There were 15 Salter-Harris type 3, 13 Salter-Harris type 4, seven triplanar, and two Tillaux-Chaput fractures. Both intraobserver and interobserver reliabilities were slightly higher for CT scan evaluations. Amounts of displacement were found to be measured higher after CT scan evaluations other than radiographs. After the measurement of joint displacements on CT scans, it was observed that the measurements found below 2 mm on the digital radiograph measurement changed to greater than or equal to 2 mm in 16.4% of the patients.

CONCLUSIONS

This study confirmed that digital radiographs cannot replace CT scans for the measurement of intra-articular displacement in ankle epiphyseal fractures.

Gantry-Free High-Resolution Cone-Beam CT: Efficacy for Distal Radius and Scaphoid Fracture Detection and Characterization

OBJECTIVES

Gantry-free cone-beam CT (CBCT) allows for comfortable patient positioning due to an open scanner architecture. Since CBCT without gantry is not yet established for clinical wrist trauma imaging, this study's aim was to investigate its diagnostic value in the preoperative workup of patients with distal radius and scaphoid fractures.

METHODS

Within a 12-month period, 113 patients with severe wrist trauma underwent both radiography and CBCT with the same gantry-free multi-use scanner before surgery. Two radiologists retrospectively analyzed all datasets for the morphology of distal radius (n = 95) and scaphoid fractures (n = 20). In all 115 wrists (two bilateral injuries), surgical reports served as the standard of reference.

RESULTS

While accuracy for distal radius fractures was comparable among CBCT and radiographs, the former was superior with regard to scaphoid fractures (Reader 1: 100.0% vs. 75.0%; Reader 2: 100.0% vs. 65.0%). Accuracy for multi-fragmentary radius injuries (100.0% vs. 90.5%; 100.0% vs. 93.7%), and articular affliction (99.0% vs. 84.2%; 100.0% vs. 83.2%) was also higher in CBCT. Regarding scaphoid fractures, CBCT proved superior for diagnosis of proximal pole or waist involvement (100.0% vs. 70.0%; 100.0% vs. 65.0%) and comminuted patterns (100.0% vs. 70.0%; 100.0% vs. 75.0%). Median effective dose of CBCT was as low as 3.65 µSv compared with 0.16 µSv for standard radiography.

CONCLUSION

Gantry-free CBCT allows for excellent diagnostic accuracy in the assessment of distal radius and scaphoid fracture morphology. Even in patients with limited mobility, very low radiation dose is sufficient to maintain high image quality.

Impacted intraarticular fragments of distal radius fractures: A radiographic characterization and analysis of reliability and diagnostic accuracy

BACKGROUND

Reduction using ligamentotaxis may not be effective enough to treat impacted intraarticular fragments of distal radius fractures. Articular incongruence resulting from the loss of reduction is a risk factor for postoperative osteoarthritis and worse clinical outcome. This study aimed to analyze the radiographic characterization of the impacted intraarticular fragments of distal radius fractures using two/three-dimensional computed tomography (CT). Further, we assessed the reliability and diagnostic accuracy in detecting the fragments using plain radiographs.

METHODS

We analyzed 167 three-dimensional CT images of the intraarticular distal radius fractures and selected 12 fractures with impacted intraarticular fragments. We recorded the location, size, and displacement of the fragment using CT images. In addition, six examiners evaluated 25 fractures including those 12 fractures having the fragments using plain radiographs for detecting the fragments and their displacements. Further, we evaluated the reliability and diagnostic accuracy of the plain radiographs in the detection of the fragment.

RESULTS

Fifteen impacted intraarticular fragments were found in 12 wrists. The displacement of the scaphoid facet fragment was significantly larger than that of the lunate facet fragment in CT measurement (7.0 mm and 3.6 mm). Inter and intraobserver reliability of the diagnosis for the fragment in plain radiographs were poor and fair (κ: 0.14 and κ:0.27). Diagnostic accuracy in detecting the fragment in plain radiographs generated mean sensitivity: 0.4, mean specificity: 0.73, and mean accuracy: 0.58. The mean sensitivity in detecting a lunate facet fragment was lower than that of a scaphoid facet fragment in plain radiographs (0.24 and 0.44).

CONCLUSION

Impacted intraarticular fragments were found in 7% of intraarticular distal radius fractures. We observed low reliability and sensitivity in detecting the fragment using plain radiographs. Preoperative recognition of the fragments using plain radiograph were difficult, even though the magnitude of step-off of the scaphoid facet fragment was large.

The effect of tin prefiltration on extremity cone-beam CT imaging with a twin robotic X-ray system

INTRODUCTION

While tin prefiltration is established in various CT applications, its value in extremity cone-beam CT relative to optimized spectra has not been thoroughly assessed thus far. This study aims to investigate the effect of tin filters in extremity cone-beam CT with a twin-robotic X-ray system.

METHODS

Wrist, elbow and ankle joints of two cadaveric specimens were examined in a laboratory setup with different combinations of prefiltration (copper, tin), tube voltage and current-time product. Image quality was assessed subjectively by five radiologists with Fleiss' kappa being computed to measure interrater agreement. To provide a semiquantitative criterion for image quality, contrast-to-noise ratios (CNR) were compared for standardized regions of interest. Volume CT dose indices were calculated for a 16 cm polymethylmethacrylate phantom.

RESULTS

Radiation dose ranged from 17.4 mGy in the clinical standard protocol without tin filter to as low as 0.7 mGy with tin prefiltration. Image quality ratings and CNR for tin-filtered scans with 100 kV were lower than for 80 kV studies with copper prefiltration despite higher dose (11.2 and 5.6 vs. 4.5 mGy; p < 0.001). No difference was ascertained between 100 kV scans with tin filtration and 60 kV copper-filtered scans with 75% dose reduction (subjective: p = 0.101; CNR: p = 0.706). Fleiss' kappa of 0.597 (95% confidence interval 0.567-0.626; p < 0.001) indicated moderate interrater agreement.

CONCLUSION

Considerable dose reduction is feasible with tin prefiltration, however, the twin-robotic X-ray system's low-dose potential for extremity 3D imaging is maximized with a dedicated low-kilovolt scan protocol in situations without extensive beam-hardening artifacts.

IMPLICATIONS FOR PRACTICE

Low-kilovolt imaging with copper prefiltration provides a superior trade-off between dose reduction and image quality compared to tin-filtered cone-beam CT scan protocols with higher tube voltage.

Radiography of the Distal Radius

Imaging of the distal radius is of paramount importance in diagnosing injuries, indicating patients for operative or nonoperative treatment, and appropriately following patients for associated injuries and complications. Plain radiographs and fluoroscopy are the dominant imaging modalities in all settings because they are readily available and provide valuable information about the osseous structures and any instrumentation. Computed tomography can offer more information about implant placement and the level of comminution of the articular surfaces but is more expensive and exposes patients to higher doses of radiation. Magnetic resonance imaging is less commonly used but is useful for occult fractures and other associated injuries. Ultrasonography is gaining popularity in evaluating implant placement, especially regarding tendon impingement and subsequent tendon injury.

Clinical impact of intraoperative cone beam tomography and navigation for displaced acetabular fractures: a comparative study at medium-term follow-up

INTRODUCTION

The use of per-operative cone beam tomography imaging for displaced acetabular fractures yields increased post-operative articular reduction accuracy. This study evaluates the need for total hip replacement (THR) and hip-related functional outcomes in patients with displaced acetabular fractures treated with O-ARM guidance compared to those treated under C-ARM guidance.

MATERIALS AND METHODS

This is a prospective matched cohort study. Adult patients (35) with acetabular fractures operated under O-ARM guidance were included. These were matched (age, fracture type) to classically treated patients (35) from our data base. The primary outcome was the need for THR during three year follow-up period. Secondary outcomes were functional scores [Harris Hip score (HHS), Postel-Merle d'Aubigné (PMA)] and hip osteoarthritis grade at three year follow-up. Correlation between reduction gap and THR was evaluated.

RESULTS

At three years, five patients were lost to follow-up in O-ARM group and four in control group. Two patients (6.66%) in the O-ARM group needed THR compared to eight patients in controls (25.80%) (p = 0.046). Hip X-ray osteoarthritis grade averaged 0.00 in patients without THR in O-ARM group compared to 0.22 in patients without THR in controls (p = 0.008). HHS averaged 95.79 in patients without THR in O-ARM group, compared to 93.82 in patients without THR in the control group (p = 0.41%). PMA averaged 17.25 in patients without THR in the O-ARM group compared to 17.04 in patients without THR in group 2 (p = 0.37). Evaluation of correlation between reduction gap and THR rate yielded OR = 1.22 (1.06-1.45).

DISCUSSION

Increased accuracy in articular reduction, with per-operative three-dimensional control of impaction, in acetabular fractures led to significantly less need for THR in patients treated under O-ARM. Patients in both groups are comparable for functional outcomes because those with the lowest scores were offered THR. Per-operative cone beam guidance and navigation use are recommended in tertiary referral centres for acetabular trauma.

Computer-Aided Assessment of Displacement and Reduction of Distal Radius Fractures

This study aims to investigate displacements and reductions of distal radius fractures using measurement indices based on the computer-aided three-dimensional (3D) radius shape model. Fifty-two distal radius fracture patients who underwent osteosynthesis were evaluated with pre- and post-operative distal radius 3D images. In the 3D images, three reference points, i.e., the radial styloid process (1), sigmoid notch volar, and dorsal edge (2) (3) were marked. The three-dimensional coordinates of each reference point and the barycentric coordinates of the plane connecting the three reference points were evaluated. The distance and direction moved, due to the reductions for each reference point, were (1) 12.1 ± 8.1 mm in the ulnar-palmar-distal direction, (2) 7.5 ± 4.1 mm in the ulnar-palmar-proximal direction, and (3) 8.2 ± 4.7 mm in the ulnar-palmar-distal direction relative to the preoperative position. The barycentric coordinate moved 8.4 ± 5.3 mm in the ulnar-palmar-distal direction compared to the preoperative position. This analyzing method will be helpful to understand the three-dimensional direction and the extent of displacements in distal radius fractures.

Three-dimensional evaluations of preoperative planning reproducibility for the osteosynthesis of distal radius fractures

BACKGROUND

Three-dimensional preoperative planning was applied for the osteosynthesis of distal radius fractures. The objective of this study was to evaluate the reproducibility of three-dimensional preoperative planning for the osteosynthesis of distal radius fractures with three-dimensional reference points.

METHODS

Sixty-three wrists of 63 distal radius fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. After taking preoperative CT scans of the injured wrists, 3D images of the distal radius were created. Fracture reduction, implants choices, and placements simulation were performed based on the 3D images. One month after the surgery, postoperative CT images were taken. The reproducibility was evaluated with preoperative plan and postoperative 3D images. The images were compared with the three-dimensional coordinates of radial styloid process, volar and dorsal edges of sigmoid notch, and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. The reproducibility of radial inclination and volar tilt on three-dimensional images were evaluated by intra-class correlation coefficient (ICC).

RESULTS

The distances between the preoperative plan and the postoperative reduction for each reference point were (1) 2.1±1.3 mm, (2) 1.9±1.2 mm, and (3) 1.9±1.2 mm, respectively. The distance between the preoperative plan and postoperative reduction for the barycentric coordinate was 1.3±0.8 mm. ICCs were 0.54 and 0.54 for the volar tilt and radial inclination, respectively (P<0.01).

CONCLUSIONS

Three-dimensional preoperative planning for the osteosynthesis of distal radius fracture was reproducible with an error of about 2 mm for each reference point and the correlations of reduction shapes were moderate. The analysis method and reference points may be helpful to understand the accuracy of reductions for the three-dimensional preoperative planning in the osteosynthesis of distal radius fractures.

TRIAL REGISTRATION

Registered as NCT02909647 at ClinicalTrials.gov.

Intraoperative computed tomography with an integrated navigation system versus freehand technique under fluoroscopy in the treatment of intra-articular distal radius fractures

Volar locking plate (VLP) fixation for distal radius fractures (DRF) is a technically demanding procedure, where accurate placement of the distal screws for subchondral articular support is essential. The purpose of this retrospective, case-control study was to compare a computed tomography (CT) navigation system for VLP fixation of intra-articular DRF with conventional freehand fluoroscopy guided surgery. Twelve consecutive patients with DRF, AO type C3.1, underwent VLP fixation using intraoperative CT navigation (navigated group) and 16 consecutive patients had conventional freehand fluoroscopy guided surgery (non-navigated group). Follow-up was done mean 12 (range, 4-18) months after surgery. Radiological outcomes included evaluation of placement for the distal fixation screws and radiological parameters such as; radial inclination, palmar tilt, ulnar variance, fracture-gap, and step-off. Clinical outcomes included grip strength, wrist range of motion, Mayo wrist score, and the Disabilities of the arm, shoulder and hand (DASH) questionnaire. Dorsal cortical and articular screw penetrations were significantly more common in the non-navigated group compared with the navigated group. At the final follow-up, a significantly larger intra-articular fracture gap was observed in the non-navigated group compared to the navigated group. There were no significant differences in clinical outcomes between the two treatment groups. Our results suggest that CT navigation guided surgery for VLP fixation of type C3 DRF, compared with conventional freehand fluoroscopy guided surgery, provides a more accurate placement of the distal screws which minimize the risk for intra-articular and dorsal cortical screw penetration.

Single-shot CT after wrist trauma: impact on detection accuracy and treatment of fractures

OBJECTIVE

To evaluate accuracy of fracture detection and therapeutic impact of a single-shot CT protocol as a primary imaging tool in all patients with clinical suspicion of wrist injury, and evaluate the resulting impact on therapy.

MATERIALS AND METHODS

We performed a single-institution study on all patients with suspicion of fractures of the wrist and carpus. All patients underwent conventional radiography, thereafter single-shot wrist CT, and then 1-year follow-up. Physicians and radiologists prospectively scored likelihood of fracture presence on a five-point scale before and after CT. Three surgeons proposed a treatment regimen (functional, cast, reduction, or operative) based on clinical and radiological data, first with knowledge of conventional radiography, and then with knowledge of CT. The reference standard for fracture presence was based on all data. We performed receiver operating characteristic (ROC) analyses and calculated proportion of wrists with treatment changes due to CT imaging.

RESULTS

Ninety-eight patients participated (63% female, mean age 53, range, 18-87 years old) with 100 wrist CTs. Conventional radiography detected true-positive fractures in 45, and CT in 61 wrists. The areas under the curve for fracture detection were 0.85 (95% CI 0.77-0.93) for conventional radiography and 0.97 (95% CI 0.93-1.00) for CT. Treatment changed in 24 (24%, 95% CI 16-33%) - 31 (31%, 95% CI 23-41%) wrists, mostly involving a decrease in the rate of cast immobilization.

CONCLUSIONS

Single-shot CT in patients with clinical suspicion of wrist injury increases accuracy of fracture detection. This has a significant impact therapy in this population, mainly on cast immobilization.

TRIAL REGISTRATION

We registered the study at www.clinicaltrials.gov , NL43482.091.13.

Intraoperative Cone Beam Tomography and Navigation for Displaced Acetabular Fractures: A Comparative Study

OBJECTIVES

To evaluate the accuracy of reduction of the acetabular articular surface using an intraoperative computed tomography scanner (O-Arm) and screw navigation compared with a classical open technique.

DESIGN

Prospective matched cohort study.

SETTING

Tertiary referral center.

PATIENTS/PARTICIPANTS

Adult patients with acute acetabular fractures were included in the study. All patients were treated by 2 senior surgeons using intraoperative imaging and screw navigation.

MAIN OUTCOME MEASUREMENTS

The primary outcome measure was articular reduction. Secondary outcomes were radiation dosage, operative variables [operative time, time for image acquisition, intraoperative bleeding (cell saver), number of surgical plates, and number of screws], and postoperative variables (first postoperative day pain on the visual analog scale, postoperative transfusion, and hemoglobin change). P < 0.05 was considered statistically significant.

RESULTS

Thirty-five patients were treated in the inclusion period (2016-2017) and were matched to 35 cases in our database (2013-2016). Mean age was 43 years, and the most common fracture type was a both-column fracture (OTA/AO type C). Postoperative image analysis showed that reduction was achieved in 87.1% of the cases in the O-Arm group versus 64.7% in the control group (P < 0.05). Mean gap of the articular fragments was 3.6 mm in the O-Arm group compared with 5.6 mm (P = 0.01) in the control group. There was no significant difference between the 2 groups in regards to all other studied variables except a decrease in intraoperative blood loss and transfusions and an increase in surgical time with the O-Arm group. Finally, the total radiation dose was decreased using the intraoperative O-Arm compared with a routine postoperative computed tomography scan (dose length product in O-Arm: 498 mGy.cm; dose length product in historical group: 715 mGy.cm).

CONCLUSIONS

Using intraoperative imaging and screw navigation for displaced acetabular fractures allow screw navigation with increasing articular surface reduction accuracy. Operative and anesthesia times were not increased, whereas radiation exposure to the patient was significantly decreased. We recommend the use of intraoperative imaging for the treatment of displaced acetabular fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Secondary Abutment Syndromes of the Wrist in Trauma: A Pictorial Essay

Traumatic lesions of the wrist occur frequently and may give rise to underdiagnosed secondary abutment syndromes. The latter are a common cause of incapacitating pain and limited range of motion, despite minimal or even absent alterations on radiographs. Moreover, the complex wrist anatomy often results in ignorance or underappreciation of these syndromes.

This paper presents a pictorial review of frequent and rare secondary abutment syndromes at the wrist joint, which – in contrast to primary abutment syndromes – are not based on anatomical variants or congenital deformations. The merit of each imaging modality is briefly mentioned.

Evidence-Based Review of Distal Radius Fractures

Distal radius fractures are one of the most commonly treated fractures in the United States. The highest rates are seen among the elderly, second only to hip fractures. With the increasing aging population these numbers are projected to continue to increase. Distal radius fractures include a spectrum of injury patterns encountered by general practitioners and orthopedists alike. This evidence-based review of distal radius fractures incorporates current and available literature on the diagnosis, management, and treatment of fractures of the distal radius.

Effective Radiation Dose in the Wrist Resulting from a Radiographic Device, Two CBCT Devices and One MSCT Device: A Comparative Study

The objective of the present study was to assess and compare the effective doses in the wrist region resulting from conventional radiography device, multislice computed tomography (MSCT) device and two cone beam computed tomography (CBCT) devices using MOSFET dosemeters and a custom made anthropomorphic RANDO phantom according to the ICRP 103 recommendation. The effective dose for the conventional radiography was 1.0 μSv. The effective doses for the NewTom 5 G CBCT ranged between 0.7 μSv and 1.6 μSv, for the Planmed Verity CBCT 2.4 μSv and for the MSCT 8.6 μSv. When compared with the effective dose for AP- and LAT projections of a conventional radiographic device, this study showed an 8.6-fold effective dose for standard MSCT protocol and between 0.7 and 2.4-fold effective dose for standard CBCT protocols. When compared to the MSCT device, the CBCT devices offer a 3D view of the wrist at significantly lower effective doses.

Use of Computed Tomography in Determining the Occurrence of Dorsal and Intra-articular Screw Penetration in Volar Locking Plate Osteosynthesis of Distal Radius Fracture

Background: The use of volar locking plate in distal radius fracture can lead to extensor tendon rupture due to dorsal screw penetration. The aim of our study was to investigate the occurrence of dorsal and intra-articular screw penetration using CT scan after volar distal radius osteosynthesis for distal radius fractures.

Methods: Thirty patients who underwent distal volar locking plate for distal radius fracture were included in a retrospective study. In all 30 patients no dorsal and intra-articular screw penetration were detected on standard AP and lateral views of a plain radiograph. CT scan of the operated wrist was performed to determine the number of intra-articular and dorsal screw penetrations. Clinical examination was performed to determine the wrist functions in comparison to the normal wrist.

Results: Nineteen wrists were noted to have screw penetration either dorsally or intraarticularly. The highest incidence is in the 2nd extensor compartment where 13 screws had penetrated with a mean of 2.46 mm. Six screws penetrated into the distal radial ulnar joint and five screws into the wrist joint with a mean of 2.83 mm and 2.6 mm, respectively. However, there was no incidence of tendon irritation or rupture.

Conclusions: This study demonstrated a high incidence of dorsal and intra-articular screw penetration detected by CT scan which was not apparent in plain radiograph. We recommend that surgeons adhere to the principle of only near cortex fixation and downsizing the locking screw length by 2 mm.

Evaluation of radiographic fracture position 1 year after variable angle locking volar distal radius plating: a prospective multicentre case series

Treatment with a variable angle locking plate can, in theory, maintain near anatomic reduction of intra-articular distal radius fractures, but it is unknown to what extent reduction is maintained as measured by computed tomography. We assessed changes in radiographic fracture position 1 year post-operatively. We included 73 patients of whom 66 patients (90%) had radiographs available for review at 1 year post-operatively. We found a small (less than 2 mm or 2°) but statistically significant change in several measures. Accounting for inter-observer variability, this is probably within measurement error. We found no difference in change in fracture position or range of motion, grip strength or patient-reported outcome between the use of one or two distal rows of screws. Our results show that minimal changes in reduction can be expected after volar plate fixation in most patients. We recommend using only one screw row routinely, limiting costs, surgical time and the risk of misplacement of screws.

LEVEL OF EVIDENCE

IV.

Spectrum bias, a common unrecognised issue in orthopaedic agreement studies: do CT scans really influence the agreement on treatment plans in fractures of the distal radius?

Objectives

Current studies on the additional benefit of using computed tomography (CT) in order to evaluate the surgeons’ agreement on treatment plans for fracture are inconsistent. This inconsistency can be explained by a methodological phenomenon called ‘spectrum bias’, defined as the bias inherent when investigators choose a population lacking therapeutic uncertainty for evaluation. The aim of the study is to determine the influence of spectrum bias on the intra-observer agreement of treatment plans for fractures of the distal radius.

Methods

Four surgeons evaluated 51 patients with displaced fractures of the distal radius at four time points: T1 and T2: conventional radiographs; T3 and T4: radiographs and additional CT scan (radiograph and CT). Choice of treatment plan (operative or non-operative) and therapeutic certainty (five-point scale: very uncertain to very certain) were rated. To determine the influence of spectrum bias, the intra-observer agreement was analysed, using Kappa statistics, for each degree of therapeutic certainty.

Results

In cases with high therapeutic certainty, intra-observer agreement based on radiograph was almost perfect (0.86 to 0.90), but decreased to moderate based on a radiograph and CT (0.47 to 0.60). In cases with high therapeutic uncertainty, intra-observer agreement was slight at best (-0.12 to 0.19), but increased to moderate based on the radiograph and CT (0.56 to 0.57).

Conclusion

Spectrum bias influenced the outcome of this agreement study on treatment plans. An additional CT scan improves the intra-observer agreement on treatment plans for a fracture of the distal radius only when there is therapeutic uncertainty. Reporting and analysing intra-observer agreement based on the surgeon’s level of certainty is an appropriate method to minimise spectrum bias.

Cite this article: Bone Joint Res 2015;4:190–194.

Radiographical measurements for distal intra-articular fractures of the radius using plain radiographs and cone beam computed tomography images

OBJECTIVE

Operative treatment of an intra-articular distal radius fracture is one of the most common procedures in orthopedic and hand surgery. The intra- and interobserver agreement of common radiographical measurements of these fractures using cone beam computed tomography (CBCT) and plain radiographs were evaluated.

MATERIALS AND METHODS

Thirty-seven patients undergoing open reduction and volar fixation for a distal radius fracture were studied. Two radiologists analyzed the preoperative radiographs and CBCT images. Agreement of the measurements was subjected to intra-class correlation coefficient and the Bland-Altman analyses.

RESULTS

Plain radiographs provided a slightly poorer level of agreement. For fracture diastasis, excellent intraobserver agreement was achieved for radiographs and good or excellent agreement for CBCT, compared to poor interobserver agreement (ICC 0.334) for radiographs and good interobserver agreement (ICC 0.621) for CBCT images. The Bland-Altman analyses indicated a small mean difference between the measurements but rather large variation using both imaging methods, especially in angular measurements.

CONCLUSIONS

For most of the measurements, radiographs do well, and may be used in clinical practice. Two different measurements by the same reader or by two different readers can lead to different decisions, and therefore a standardization of the measurements is imperative. More detailed analysis of articular surface needs cross-sectional imaging modalities.

Computed tomography's influence on the classifications and treatment of the distal radius fractures

INTRODUCTION

Distal radius fractures are common in emergency centers. The radiographic routine includes at least two radiographic projections used for diagnosing most of these fractures. Computed tomography (CT) is indicated for evaluating complex fractures that affect the articular surface, as well as the fragments' size and position. There are not enough comparative studies on choosing classification and treatment by means of the four radiographic projections and computed tomography (CT) and the association of these with the levels of expertise.

METHODS

We conducted a randomized cross-sectional study by observing images from 61 patients with distal radius fractures organized in two phases: the first phase comprising radiographic images alone and the second one with those same images associated with tomograms. Seventeen evaluators with different levels of training and expertise classified the fractures according to the AO and Universal classification systems and proposed treatment guidelines.

RESULTS

The agreement between the AO and Universal classification ratings was poor (worse for the former), with smaller Fleiss' kappa resulting from data obtained by orthopedics residents and non-specialist orthopedists. CT influenced the classification choice, with a higher change frequency for more complex patterns in the AO classification system and intra-articular and irreducible fractures in the Universal classification system, especially in the group comprised of orthopedic residents and orthopedic physicians. CT did not influence the treatment choice made by the group comprised of hand surgery residents and hand surgeons.

CONCLUSION

The less experienced in hand surgery the observer was, the more important computed tomography was for determining the fracture pattern.

AO type-C distal radius fractures: the influence of computed tomography on surgeon's decision-making

BACKGROUND

Computed tomography (CT) has become a widely accepted adjunct imaging tool in the preoperative evaluation of complex intra-articular distal radius fractures. The aim of this study was to evaluate the impact of CT scanning compared with plain X-rays on the choice of intervention in complex distal radius fractures.

METHODS

Five orthopaedic surgeons were given the de-identified plain films (AP, lateral and oblique) of 20 closed complex intra-articular distal radius fractures (AO23-C), randomly selected from our institution's prospectively maintained fracture database. Each surgeon individually selected a management option for each patient from a series of five interventions, ranked in increasing level of invasiveness. The same patients' CT scans (in randomized order) were blindly reviewed after a 1-week interval by the same clinicians with the same management options again offered. Kappa statistic was used to measure the intra-observer agreement between X-ray and CT decisions, and inter-observer agreement within each modality.

RESULTS

The intra-observer agreement on management between X-rays alone versus CT scan was poor, with an average kappa score of 0.038. Inter-observer agreement based on X-ray alone was higher than that based on CT alone. Regression analysis indicated a trend towards a slightly higher level of invasiveness when the management decision was based on the CT compared with plain X-rays.

CONCLUSION

There is a very poor intra- and inter-rater agreement between decision-making based on X-ray and on CT. Decision-making based on CT could increase the level of invasiveness in the surgical management of complex distal radius fractures.