Natural experiments for orthopaedic trauma research: An introduction

Let Us Agree to Disagree on Operative Versus Nonoperative Treatment for Proximal Humerus Fractures: A Multicenter International Prospective Cohort Study of Gray-Zone, Clinical Equipoise Fractures

Background

Internationally, the optimal treatment strategy of proximal humerus fractures remains much debated.

Methods

To investigate whether operative treatment of displaced proximal humerus fractures is superior to nonoperative treatment, this international multicenter prospective natural experiment based on clinical equipoise was performed. Two hundred twenty-six patients with acute proximal humerus fractures presenting from July 2020 to March 2022 were included after expert panel evaluation, consisting of Dutch and Swiss surgeons with diverse ideas on optimal treatment. Patients were included when no consensus on optimal treatment was reached i.e., clinical equipoise. Follow-up was completed after 1 year (n = 191 [84%]). The primary outcome was Quick Disability of the Arm, Shoulder, and Hand (QuickDASH) after 1 year. Secondary outcomes included QuickDASH at 6 weeks and EQ5D, Subjective Shoulder Value (SSV), Numeric Rating Scale (NRS) for pain at 6 weeks and 1 year.

Results

No difference in QuickDASH score after 1 year (12.8 vs. 16.2, p = 0.73) was found. At 6 weeks, operative treatment resulted in lower NRS (4.3 vs. 3.0, p < 0.001), higher EQ5D (0.59 vs. 0.67, p = 0.011), and higher SSV (40.9 vs. 51.4, p = 0.005). At 1 year, operative treatment resulted in higher SSV (72.1 vs. 83.7, p = 0.002), while EQ5D was comparable (0.87 vs. 0.85, p = 0.95).

Conclusion

No difference between treatments was observed in the primary outcome. Patient-tailored care may still include counseling operative treatment to patients to reduce short-term pain and/or facilitate early return to sport/work in young active patients.

Level of Evidence

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

Preventing confounding in observational studies in orthopedic trauma surgery through expert panels: a systematic review

PURPOSE

Confounding in observational studies can be mitigated by selecting only those patients, in whom equipoise of both treatments is secured by experts' disagreement over optimal therapy.

METHODS

We conducted a systematic review to identify observational studies in the field of orthopedic trauma surgery that utilized expert panels for patient inclusion in order to limit the potential for confounding.

RESULTS

Four studies were identified that used expert panels to select participants based on expert disagreement. Derived from these studies and our own experience, recommendations were made regarding reporting of the size and composition of the expert panel, the information the expert panel receives, criteria for disagreement, selection of patients, and statistical analysis.

CONCLUSION

With this review we aim to provide insight into this study design and to stimulate discussions about the potential of expert panels to control for confounding in studies of medical treatments.

[Surgical access route and choice of implant in the region of the clavicle shaft]

BACKGROUND

Clavicle fractures are among the most frequent injuries of the shoulder girdle. Nondisplaced fractures are generally treated conservatively, whereas dislocated fractures require surgical reduction and stabilization. A variety of implants and surgical techniques with reliable results are available. While all techniques provide similar healing rates, they share a common disadvantage with the high incidence of implant irritation and correspondingly high rates of second interventions for material removal.

OBJECTIVE

The various surgical techniques for clavicle shaft fractures with their specific areas of application as well as advantages and disadvantages are presented. This review also provides an aid for deciding which surgical technique is most appropriate based on the fracture morphology. Furthermore, an overview of current research activities is presented, with a specific focus on new implants which could help to reduce implant irritation.

RESULTS AND CONCLUSION

Open superior and anteroinferior plate osteosyntheses each show similar reliable results. The minimally invasive plate osteosynthesis (MIPO) technique offers an alternative for multifragmented fractures as it has a lower complication rate compared to the open procedure. Double plate osteosynthesis using minifragment plates shows promising results with respect to the incidence of implant-related irritation. Larger prospective studies are still pending. Intramedullary nailing offers a good alternative, especially if material removal is planned anyway, e.g., in the pediatric setting.

Routine 6-Week Outpatient Radiography and Visit in Patients with Conservatively Treated Multiple Rib Fractures: Valuable or a Waste of Resources?

Background

This study investigated the incidence and clinical consequences of abnormal radiological and clinical findings during routinely performed 6-week outpatient visits in patients treated conservatively for multiple (3 or more) rib fractures.

Methods

A retrospective analysis was conducted among patients with multiple rib fractures treated conservatively between 2018 and 2021 (Opvent database). The primary outcome was the incidence of abnormalities on chest X-ray (CXR) and their clinical consequences, which were categorized as requiring intervention or additional clinical/radiological examination. The secondary focus was the incidence of deviation from standard treatment in response to the findings (clinical or radiological) at the routine 6-week outpatient visit.

Results

In total, 364 patients were included, of whom 246 had a 6-week visit with CXR. The median age was 57 years (interquartile range, 46-70 years) and the median Injury Severity Score was 17 (interquartile range, 13-22). Forty-six abnormalities (18.7%) were found on CXR. These abnormalities resulted in additional outpatient visits in 4 patients (1.5%) and in chest drain insertion in 2 (0.8%). Only 2 patients (0.8%) with an abnormality on CXR presented without symptoms. None of the 118 patients who had visits without CXR experienced problems.

Conclusion

Routine 6-week outpatient visits for patients with conservatively treated multiple rib fractures infrequently revealed abnormalities requiring treatment modifications. It may be questioned whether the 6-week outpatient visit is even necessary. Instead, a more targeted approach could be adopted, providing follow-up to high-risk or high-demand patients only, or offering guidance on recognizing warning signs and providing aftercare through a smartphone application.

Natural Experiments as a Study Method in Spinal Trauma Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

To determine if the natural experiment design is a useful research methodology concept in spinal trauma care, and to determine if this methodology can be a viable alternative when randomized controlled trials are either infeasible or unethical.

METHODS

A Medline, Embase and Cochrane database search was performed between 2004 and 2023 for studies comparing different treatment modalities of spinal trauma. All observational studies with a natural experiment design comparing different treatment modalities of spinal trauma were included. Data extraction and quality assessment with the MINORS criteria was performed.

RESULTS

Four studies with a natural experiment design regarding patients with traumatic spinal fractures were included. All studies were retrospective, one study collected follow-up data prospectively. Three studies compared different operative treatment modalities, whereas one study compared different antibiotic treatment strategies. Two studies compared preferred treatment modalities between expertise centers, one study between departments (neuro- and orthopedic surgery) and one amongst surgeons. For the included retrospective studies, MINORS scores (maximum score 18) were high ranging from 12-17 and with a mean (SD) of 14.6 (1.63).

CONCLUSIONS

Since 2004 only four studies using a natural experiment design have been conducted in spinal trauma. In the included studies, comparability of patient groups was high emphasizing the potential of natural experiments in spinal trauma research. Natural experiments design should be considered more frequently in future research in spinal trauma as they may help to address difficult clinical problems when RCT's are infeasible or unethical.

Does plate position influence the outcome in midshaft clavicular fractures? A multicenter analysis

PURPOSE

To date, it remains unclear whether superior or anterior plating is the best option for treating midshaft clavicular fractures. The aim of this study was to compare both techniques with regard to the incidence of implant removal due to implant irritation, risk of complications, time to union, and function.

METHODS

In this retrospective cohort study, all midshaft clavicular fractures treated operatively between 2017 and 2020 in two hospitals in Switzerland were analyzed. The participating hospitals differed with regard to their standard practice; one offered superior plating only, while the other predominantly employed an anterior plate. The primary outcome was the incidence of implant removal for irritation. Secondary outcomes were time to union, complications, re-interventions, and range of motion during the follow-up period of at least 6 months.

RESULTS

In total, 168 patients were included in the study of which 81 (48%) received anterior plating and 87 (52%) superior plating. The overall mean age was 45 years (SD 16). There was no significant difference between anterior and superior plating with regard to implant removal (58.5% versus 57.1%, p = 0.887), infection (5.7% versus 1.8%, p = 0.071), and time to union (median 48 weeks versus 52 weeks, p = 0.643). Data on range of motion were available in 71 patients. There was no significant difference in anteflexion (median 180 degrees anterior versus 180 degrees superior) and abduction (median 180 degrees anterior versus 180 degrees superior) between the two groups.

CONCLUSION

This retrospective cohort study did not find sufficient evidence to recommend one implant position over the other for midshaft clavicular fractures with regard to removal due to irritation. Time to union was similar and Infections were equally rare in both groups. Notably, a considerable number of patients in both groups had their implants removed due to irritation. Larger prospective studies are needed to determine how much plate position contributes to the occurrence of irritation and whether other patient or implant-related factors might play a role. Until this is clarified, implant position should be based on surgeons preference and experience.

Let's Agree to Disagree on Operative Versus Nonoperative Treatment for Distal Radius Fractures in Older People: Protocol for a Prospective International Multicenter Cohort Study

BACKGROUND

Distal radius fractures are the most frequently encountered fractures in Western societies, typically affecting patients aged 50 years and older. Although this is a common injury, the best treatment for these fractures in older patients is still under debate.

OBJECTIVE

This prospective study aims to compare the outcome of operatively and nonoperatively treated distal radius fractures in the older population. Only patients with distal radius fractures for which equipoise regarding the optimal treatment exists will be included.

METHODS

This prospective international multicenter observational cohort study will be designed as a natural experiment. Natural experiments are observational studies in which treatment allocation is determined by factors outside the control of the investigators but also (largely) independent of patient characteristics. Patients aged 65 years and older with an acute distal radius fracture will be considered for inclusion. Treatment allocation (operative vs nonoperative) will be based on the local preferences of the treating hospital either in Switzerland or the Netherlands. Hence, the process governing treatment allocation resembles that of randomization. Patients will be identified after treatment has been initiated. Based on the radiographs and baseline information of the patient, an expert panel of 6 certified trauma surgeons from 2 regions will provide their treatment recommendation. Only patients for whom the experts disagree on treatment recommendations will ultimately be included in the study (ie, for whom there is a clinical equipoise). For these patients, both operative and nonoperative treatment of distal radius fractures are viable, and treatment choice is predominantly determined by personal or local preference. The primary outcome will be the Patient-Rated Wrist Evaluation score at 12 weeks. Secondary outcomes will include the Physical Activity Score for the Elderly, the EQ questionnaire, pain, the living situation, range of motion, complications, and radiological outcomes. By including outcomes such as living situation and the Physical Activity Score for the Elderly, which are not relevant for younger cohorts, valuable information to tailor treatment to the needs of the older population can be gained. According to the sample size collection, which was based on the minimal important clinical difference of the Patient-Rated Wrist Evaluation, 92 patients will have to be included, with at least 46 patients in each treatment group.

RESULTS

Enrollment began in July 2023 and is expected to continue until summer 2024. The final follow-up will be 2 years after the last patient is included.

CONCLUSIONS

Although many trials on this topic have previously been published, there remains an ongoing debate regarding the optimal treatment for distal radius fractures in older patients. This observational study, which will use a fairly new methodological study design, will provide further information on treatment outcomes for older patients with distal radius fractures for which to date equipoise exists regarding the optimal treatment.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/52917.

A natural experiment study: Low-profile double plating versus single plating techniques in midshaft clavicle fractures-Study protocol

BACKGROUND

Single plate osteosynthesis is commonly employed when performing surgical stabilization of midshaft clavicle fractures. In recent years, a smaller structural low-profile double plating technique has been described as a possible solution for the high removal rates associated with single plating. A previous meta-analysis has demonstrated that low-profile double plating attains the same healing rates as single plating without a higher chance of fracture-related infections. This meta-analysis, however, was based on relatively small studies. Therefore, a multicentre prospective natural experiment was designed using natural variation in treatment regimens and geographical location of the trauma as treatment allocation mechanism to compare both treatments on a larger scale. This manuscript describes its protocol.

MATERIAL & METHODS

Patients (≥16 years) with primary midshaft clavicle fractures that are eligible for operative treatment will be included. Treatment allocation will be determined by the geographical location of the accident and local hospital providing treatment. In two centres, single plating is the treatment of choice for these patients. In two others, low-profile double plating has become the standard treatment. For the low-profile double plating group, one superiorly positioned VariAx 2.0mm and one anterior VariAx 2.4mm or 2.7mm plate will be used. For the single plating group, the standard locally available implant will be used. A total of 336 patients will be included. The primary outcome of interest is re-intervention. Secondary outcomes include complications, operative time, length of incision, functional scores (DASH, EQ-5D-DL, VAS-Pain/Satisfaction) and cost-effectiveness.

DISCUSSION

This study will determine whether low-profile double plating has significant clinical and cost-effective benefits over single plating techniques in midshaft clavicle fractures. The study will also give insight in the performance of a natural experiment study design for orthopedic trauma research.

TRIAL REGISTRATION

This study has been registered on ClincialTrials.gov, identifier NCT05579873.