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

Computed Tomography Scans and Fixation Rates for Trimalleolar Ankle Fractures Over 10 Years at a Level 1 Trauma Center

Background

The posterior malleolus component of the trimalleolar ankle fracture has posed a controversial topic for diagnostic imaging and surgical management. Preoperative computed tomography (CT) scans are used to better appreciate fracture morphology and may affect management techniques. No prior study has investigated the trend in preoperative CT scan use and the rates of posterior and syndesmotic fixation for trimalleolar injuries.

Methods

This retrospective cohort study evaluated the use of preoperative CT scans and the rates of posterior and syndesmotic fixation for trimalleolar ankle fractures over a 10-year period at an adult level 1 trauma center. Patients surgically managed for ankle fractures with OTA/AO classifications of 44B3, 44C3.3, 44C1.3, 44C2.3, and 44A3 were identified and included using Current Procedural Terminology codes and a prospectively collected fracture registry. Demographic information, comorbidities, fixation methods, and use of preoperative CT scan were recorded. Comparative analyses were performed to assess for yearly differences in demographic characteristics along with changes in trends of preoperative CT scans and posterior and syndesmotic fixation.

Results

A total of 1191 patients were included in the analyses. OTA/AO 44B3.2 fractures were the most common injuries (yearly range of 59.4%-80.1%). The rate of posterior fixation did not significantly increase during the study interval (1.4% growth per year [95% CI -0.27, 3.07]). However, the rate of preoperative CT scan use significantly increased by 2.76% (95% CI 1.99, 3.52) per year and the rate of syndesmotic fixation increased by 2.58% (95% CI 1.17, 3.99) per year. Fixation methods for both the syndesmosis and posterior malleolus changed during the study timeline.

Conclusion

Despite a relatively stable rate of posterior fixation, the frequency of preoperative CT scans and use of syndesmotic fixation increased significantly over a 10-year study period.

Level of Evidence

Level IV, descriptive pilot study.

Dry Wrist Arthroscopy for Radial-Sided Wrist Disorders

The development of wrist arthroscopy has been useful in diagnosis, prognosis, and treatment of both ligament and osseous injuries. As the treatment indications and techniques become more refined, this article explores the role of dry arthroscopy to treat radial-sided disorders of the wrist.

Fracture heuristics: surgical decision for approaches to distal radius fractures. A surgeon's perspective

Introduction: The aim of the present study is to develop a heuristic that could replace the surgeon’s analysis for the decision on the operative approach of distal radius fractures based on simple fracture characteristics.

Patients and methods: Five hundred distal radius fractures operated between 2011 and 2014 were analyzed for the surgeon’s decision on the approach used. The 500 distal radius fractures were treated with open reduction and internal fixation through palmar, dorsal, and dorsopalmar approaches with 2.4 mm locking plates or underwent percutaneous fixation. The parameters that should replace the surgeon’s analysis were the fractured palmar cortex, and the frontal and the sagittal split of the articular surface of the distal radius.

Results: The palmar approach was used for 422 (84.4%) fractures, the dorsal approach for 39 (7.8%), and the combined dorsopalmar approach for 30 (6.0%). Nine (1.8%) fractures were treated percutaneously. The correlation between the fractured palmar cortex and the used palmar approach was moderate (r=0.464; p<0.0001). The correlation between the frontal split and the dorsal approach, including the dorsopalmar approach, was strong (r=0.715; p<0.0001). The sagittal split had only a weak correlation for the dorsal and dorsopalmar approach (r=0.300; p<0.0001).

Discussion: The study shows that the surgical decision on the preferred approach is dictated through two simple factors, even in the case of complex fractures.

Conclusion: When the palmar cortex is displaced in distal radius fractures, a palmar approach should be used. When there is a displaced frontal split of the articular surface, a dorsal approach should be used. When both are present, a dorsopalmar approach should be used. These two simple parameters could replace the surgeon’s analysis for the surgical approach.

Can experienced surgeons predict the additional value of a CT scan in patients with displaced intra-articular distal radius fractures?

There are no clear guidelines when an additional CT scan should be obtained for the treatment of displaced intra-articular distal radius fractures (DRF). This study aimed to investigate whether surgeons can predict the usefulness of CT scans to facilitate choice of treatment plan and/or pre-operative planning for DRF. Four surgeons evaluated 51 patients with displaced DRF. The choice of treatment (operative or nonoperative) was based on conventional radiographs. Subsequently, the surgeons were asked whether they would have requested an additional CT scan to determine this treatment choice, and also whether they required a CT scan for pre-operative planning. After 4 weeks, the additional CT scan was provided and the cases were assessed again. Based on these data, we calculated the number needed to scan (NNS) and number needed to harm (NNH) for two decision models. Model 1: Only provide a CT scan if the surgeon requested one based on their judgment of the X-rays. Model 2: CT scans for all displaced intra-articular DRF. For choice of treatment, the NNS was lower for model 1 than for model 2 (2.6 vs. 4.3) and the NNH is higher for model 1 (3.1 vs. 1.3). For pre-operative planning, the NNS (1.3 vs. 1.4) and NNH (3.7 vs. 3.4) were comparable for both models. Surgeons are able to predict the usefulness of an additional CT scan for intra-articular displaced DRF for OR indication. However, for pre-operative planning the usefulness of a CT scan is much harder to predict.

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.