Radiographic interpretation of distal radius fractures: visual estimations versus digital measuring techniques

Use of Plain Radiography of Uninjured Wrists as Patient-Specific Markers of Successful Reduction of Unilateral Distal Radius Fractures

BACKGROUND

The standard of care of distal radius fractures requiring operative intervention involves restoration of anatomical alignment radiologically by comparing preoperative films and intraoperative fluoroscopy with established values based on population norms. The objective of this study is to evaluate the use of plain radiographs obtained from the uninjured wrist of patients who present with unilateral displaced distal radius fractures as a measure of successful achievement of anatomical realignment.

METHODS

A retrospective review was performed on 133 consecutive patients who presented from August 2020 to August 2021 with a diagnosis of unilateral distal radius fracture as confirmed on 3-view plain radiography. Patients who had bilateral radiographs and underwent open reduction and internal fixation were included. The primary outcome measure was comparison of radial inclination, radial height, tilt, and ulnar variance measured by 3 observers on preoperative, 1-week postoperative, and uninjured contralateral wrist films.

RESULTS

Twenty-one patients were included for analysis. Comparison of postoperative radiologic parameters with the contralateral uninjured extremity revealed a mean radial inclination difference of 3.8°, radial height difference of 2.0 mm, volar tilt difference of 6.3°, and ulnar variance difference of 0.9 mm. The average postreduction radial height was found to deviate from contralateral radial height significantly more than from the historic radial height parameter (2.0 vs 0.6 mm, P < .001).

CONCLUSION

Attempts at achieving distal radius fracture reduction to within historical normal limits may result in an increased deviation from patient-specific anatomical parameters, especially with respect to radial height.

Treatment Patterns for Distal Radius Fractures Before and After Appropriate Use Criteria Adoption

BACKGROUND

The purpose of this study was to determine agreement with the American Academy of Orthopaedic Surgery Appropriate Use Criteria (AUC) for distal radius fractures (DRFs), before and after their adoption, and secondarily determine predictors of operative management.

METHODS

A single-institution retrospective cohort study comparing patients treated either nonoperatively (115 patients) or operatively (767 patients) for DRFs between May 1, 2008, and May 1, 2018, by 8 hand surgeons was performed. Data included demographics, injury characteristics, DRF radiographic measurements, treatment rendered, and their appropriateness according to the AUC. Statistical testing used the Fisher and χ2 tests, t test, and multiple variable logistic regression, with a significance level of .05.

RESULTS

Overall, there was a significant increase in AUC agreement for operatively treated DRFs (82.7%-89.3%, P = .01), but no difference in agreement for nonoperatively treated DRFs (12.5%-10.7%, P = .77). Age <80 years, AO classes other than B, intra-articular displacement >1 mm, radial inclination <18°, high-energy mechanism of injury, and greater than 1 week to treatment were independent predictors of operative treatment. The area under the curve for the validated regression model using the aforementioned predictors was 0.82.

CONCLUSION

Agreement with AUC for DRFs increased after its adoption for operatively treated, but not for nonoperatively treated, fractures. In addition, a predictive model for operative treatment was developed and validated. Future studies may benefit from further model refinement and testing in other patient cohorts.

Dorsally displaced distal radius fractures: introduction of Pacetti's line as radiological measurement to predict dorsal fracture displacement

BACKGROUND AND AIM OF THE WORK

In the best of our knowledge there is not yet in the literature a measurement able to assess post reduction stability of distal radius fractures.

AIM

to study the relationship between our newly introduced Pacetti's line, anatomical reduction of DRFs and post-reduction stability of fractures.

METHODS

Patients/Participants: 230 patients (122men, 108women) who sustained a dorsally displaced distal radius fracture. Close reduction procedures attempted; below elbow cast applied.

FOLLOW-UP

Pacetti's line used on true AP and lateral view xrays after reduction and casting (T0) and at 7-14 days (T1-T2).

MAIN OUTCOME MEASUREMENTS

Assessment and prediction of early displacement of DRFs.

RESULTS

The Pacetti's line intersected the lunate bone in 162 cases (70.4%) after anatomical reduction, of which 20.4% (N=33) lost anatomical reduction. Cramer's V test: significant relationship between transition of Pacetti's line through the semilunar bone and stability of anatomical reduction at T0 follow-up (p<0.001, Cramer's value=0.83). The Pacetti's line intersected the lunate bone in 119 cases (51.7%) at 7-14 days follow-up. None of patients lost anatomical reduction. Cramer's V test: significant relationship between transition of Pacetti's line through the semilunar bone and stability anatomical reduction at T1 and T2 follow-up (p<0.001, Cramer's value=0.73).

CONCLUSIONS

We strongly recommend the use of the Pacetti's line as it seems to provide reliable prediction of further fracture displacement and consequently of definitive management. The Pacetti's line seems to represent a very useful tool providing simple, feasible, efficient and reliable information on DRFs characteristics and natural course.

Radiographic measurements of the normal distal radius: reliability of computer-aided CT versus physicians' radiograph interpretation

We examined the reliability of a computer-aided cone-beam CT analysis of radiographic parameters of 50 normal distal radii and compared it with interobserver agreement of measurements made by three groups of physicians on two-dimensional plain radiographs. The intra-rater reliability of the computer-aided analysis was evaluated on 33 wrists imaged twice by cone-beam CT. The longitudinal axis, anterior tilt, radial inclination and ulnar variance were measured. The reliability of computer-aided analysis was excellent (intraclass correlation coefficient (ICC) 0.94-0.96) while the interobserver agreement of two-dimensional radiograph interpretation was good (ulnar variance, ICC 0.80-0.84) to poor (anterior tilt and radial inclination, ICC 0.20-0.42). We conclude that computer-aided cone-beam CT analysis was a reliable tool for radiographic parameter determination, whereas physicians demonstrated substantial variability especially in interpreting the angular parameters.

Assessing distal radius malrotation following fracture using computed tomography

HYPOTHESIS

When the distal fracture fragment in distal radius fractures displaces, it commonly rotates as well as shortens and angulates.

AIM

The aim of this study was to assess the frequency and magnitude of malrotation of the distal fracture fragment using computed tomography (CT).

METHODS

A retrospective radiological assessment of 85 CT scans of the distal radius, 35 following fracture and 50 normal radii, was carried out. We developed and applied a simple method for measuring rotation of the distal radius relative to the diaphysis using routine CT scans of the wrist. A Mann-Whitney analysis was used to identify differences in radial rotation between fractures and controls. Intra- and inter-observer reliability were analyzed using intra-class correlation coefficients (ICCs) and Bland-Altman plots.

RESULTS

The articular surface of the distal radius is normally rotated in the long axis of the forearm relative to the diaphysis, either into pronation or into supination. The median radial rotation angle of controls was 1° pronation (range -15° to 4°) compared to 3° pronation (range -24° to 31°) in the fracture group. The absolute rotation angle was significantly greater in the fracture group (median 10°, range 0-31° vs. 3°, range 0-15°; p < 0.001) and outside the "normal range" of controls in 26 cases indicating that 75% had rotated appreciably following injury. Intra- and inter-observer reliability of measurements were good with ICCs of 0.99 and 0.98, respectively.

CONCLUSIONS

Malrotation of the distal radius appears common following distal radius fracture. Malrotation of the distal fracture fragment has been shown to affect distal radio-ulnar joint function. Despite this, rotational deformity is rarely addressed in clinical practice as it is difficult to appreciate on simple radiographs. The simplified method described here is easy to use in routine clinical practice and also appears reliable. Measuring radial rotation may be an important consideration when planning both primary treatment and corrective osteotomy for patients with distal radial malunion.

Computer-aided 3D analysis of anatomy and radiographic parameters of the distal radius

INTRODUCTION

This study applied mathematical modeling to examine the anatomy of the distal radius; to define the radiographic parameters in a 3D imaging modality; and to report their normal ranges in the uninjured radius.

MATERIALS AND METHODS

A series of 50 cone-beam computed tomography (CBCT) scans of uninjured radii were analyzed using computer-aided image processing. The radius shape model was used to determine the optimal location for measuring the longitudinal axis. With the axis determined, the volar tilt and radial inclination angles and the areas of the articular facets and their reference points were analyzed.

RESULTS

The optimal location for determining the longitudinal axis was between 28.8 and 53.3 mm proximally from the articular surface. The mean radial inclination angle was 21.8°. The mean volar tilt angle via the most distal tips of the volar and dorsal rims was 13.0°; along the lunate and scaphoid facets it was 9.1° and 11.2°, respectively. The scaphoid facet was larger than the lunate facet and 25% of it was convex.

CONCLUSIONS

Computer-aided CBCT image processing offers an advanced tool to record 3D geometry and the radiographic parameters of the osseous structures of the wrist. Analysis of the distal radius' anatomy showed that the longitudinal axis was affected by its measurement location and subsequently also affected the determination of the angular parameters. We also report the variation of the volar tilt along the articular surface and the shapes and sizes of the articular facets.

Accuracy and Reliability of Radiographic Estimation of Volar Lip Fragment Size in PIP Dorsal Fracture-Dislocations

Background: A cadaveric study was performed to evaluate the accuracy and reliability of radiographic estimation of the volar lip fragment size in proximal interphalangeal joint fracture-dislocations. Methods: Middle phalangeal base volar lip fractures of varying size and morphology were simulated in 18 digits. Radiographs and digital photographs of the middle phalangeal joint surface were obtained pre- and postinjury. Ten orthopedic surgeons of varying levels of training estimated the fracture size based on radiographs. The estimated joint involvement on radiograph was compared with the digitally measured joint involvement. Results: Radiographic estimation underestimated the volar lip fragment size by 9.02%. Estimations possessed high intraobserver (0.76-0.98) and interobserver (0.88-0.97) reliabilities. No differences were detected between levels of surgeon training. Conclusions: The significant underestimation of the volar lip fragment size demonstrates the lack of radiographic estimation accuracy and suggests that surgeons should be mindful of these results when making treatment plans.

International Survey: Factors Associated With Operative Treatment of Distal Radius Fractures and Implications for the American Academy of Orthopaedic Surgeons' Appropriate Use Criteria

OBJECTIVES

Through an international survey, we assessed whether deciding to operatively treat an intra-articular distal radius fracture (DRF) is guided by identifiable patient and surgeon factors. In addition, we compared surgeons' treatment decisions with the American Academy of Orthopaedic Surgeons' Appropriate Use Criteria (AUC) treatment recommendations.

METHODS

This cross-sectional survey asked 224 surgeons to operatively or nonoperatively treat 28 hypothetical patients with radiographs of an intra-articular DRF. We randomized patient age (50/70 years), gender, mechanism of injury, activity level, and OTA/AO fracture type. We classified 6 fractures as "nonclinically significant displacement" and 22 as "potentially clinically significant displacement." Multilevel logistic regression analysis was performed. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported. Statistical significance was P < 0.05.

RESULTS

Patient factors independently associated with surgery included younger age (OR 6.7, P = 0.003), clinically significant fracture displacement (type B: OR 122, CI, 20-739, P < 0.001; type C: OR 59, CI, 12-300, P < 0.001), normal activity level (OR 5.0, P < 0.001), and high-energy mechanisms (OR 1.3, P = 0.002). Surgeon factors associated with recommending surgery included practicing outside the United States (Europe: OR 2.6, P < 0.001; "other": OR 4.8, P < 0.001). Hand surgeons most often selected surgery, as compared to orthopaedic trauma surgeons (OR 2.3, P = 0.001) and "other orthopaedists" (OR 2.2, P = 0.022). Thirty-seven percent of treatment decisions for patients with normal activity levels were rated by AUC recommendations as "rarely appropriate," which included 91% disagreement for 70-year-olds with nonclinically significant displacement.

CONCLUSIONS

Surgeons use patient age and fracture displacement to make treatment recommendations for intra-articular DRF. We recommend that the AUC be updated to include these clinical factors as essential components in its algorithm.

LEVEL OF EVIDENCE

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

Distal Radius Fractures: AAOS Appropriate Use Criteria Versus Actual Management at a Level I Trauma Center

BACKGROUND

The aim of this study is to determine whether the American Academy of Orthopaedic Surgeons' (AAOS) Appropriate Use Criteria (AUC) for distal radius fractures correlates with actual treatment by orthopedic hand surgeons at a level I trauma center.

METHODS

ICD-9 codes were used to retrospectively identify patients who presented with wrist fractures over 1 year. Patients with isolated distal radius fractures were evaluated using the AAOS AUC application for distal radius fractures. Actual treatment was then compared with treatment recommended by the AUC.

RESULTS

Of the 112 patients, 64 (57%) received treatment that matched the AAOS AUC recommendation as an "appropriate treatment." Actual management matched the AUC recommendation 100%, 7%, and 50% of the time, for Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) type A, B, and C fractures, respectively. Surgery was performed for type A, B, and C fractures 30%, 7%, and 50% of the time, respectively. For type B fractures, only the 2 cases that were managed operatively were in agreement with the AUC. For type C fractures, increased patient age (57 years and older) was significantly associated with nonoperative treatment decisions. Surgeon decisions for nonoperative treatment were in agreement with the AUC recommendations 40% of the time, whereas surgeon decisions for surgery matched the AUC recommendations 97% of the time.

CONCLUSIONS

We found low agreement between actual treatment decisions and the AUC-recommended "appropriate" treatments, especially for the type B and C fractures that were managed nonoperatively. The AUC favors surgery for all intra-articular fractures, while we emphasized age and fracture displacement in our decision-making process.

Anatomical Wrist Patterns on Plain Radiographs

BACKGROUND

Interpreting the structure in the wrist is complicated by the existence of multiple joints as well as variability in bone shapes and anatomical patterns. Previous studies have evaluated lunate and capitate shape in an attempt to understand functional anatomical patterns.

OBJECTIVE

The purpose of this study was to describe anatomical shapes and wrist patterns in normal wrist radiographs. We hypothesized that there is a significant relationship in the midcarpal joint with at least one consistent pattern of wrist anatomy.

METHODS

Seventy plain posteroanterior (PA) and lateral wrist radiographs were evaluated. These radiographs were part of a previously established normal database, had all been read by a radiologist as normal, and had undergone further examination by 2 hand surgeons for quality. Evaluation included: lunate and capitate shape (type 1 and 2 lunate shape according to the classification system by Viegas et al.), ulnar variance, radial inclination and height, and volar tilt.

RESULTS

A significant association was found between lunate and capitate shape using a dichotomal classification system for both lunate and capitate shapes (p=0.003). Type 1 wrists were defined as lunate type1and a spherical distal capitate. Type 2 wrists had a lunate type 2 and a flat distal capitate. No statistically significant associations were detected between these wrist types and measurements of the radiocarpal joint.

CONCLUSION

There was a significant relationship between the bone shapes within the midcarpal joint. These were not related to radiocarpal anatomical shape. Further study is necessary to better describe the two types of wrist patterns that were defined and to understand their influence on wrist biomechanics and pathology.

Are radiographic measurements of the displacement of a distal radial fracture reliable and reproducible?

AIMS

The degree of displacement of a fracture of the distal radius is an important factor which can be assessed using simple radiographic measurements. Our aim was to investigate the reliability and reproducibility of these measurements and to determine if they should be used clinically.

PATIENTS AND METHODS

A 10% sample was randomly generated from 3670 consecutive adult patients who had presented to University Hospitals of Leicester NHS Trust between 2007 and 2010 with a fracture of the distal radius. Radiographs of the 367 patients were assessed by two independent reviewers. Four measurements of displacement of the fracture were recorded and the inter-observer correlation assessed using the intra-class correlation coefficient.

RESULTS

Inter-observer correlation was high (> 0.8) for three of the four measurements. Repeat measurements of a further randomly generated 10% sample (37) were made four weeks later to assess intra-observer agreement, which was again high (> 0.8) for the same three parameters (radial height, radial inclination and dorsal/palmar tilt). Correlation was poor for articular step and gap.

CONCLUSION

Radiographic assessment of radial angle, radial inclination and dorsal/palmar tilt is a reliable method of determining the degree of displacement of a fracture of the distal radius. Cite this article: Bone Joint J 2016;98-B:1069-73.