Abstract
Introduction
Scaphoid fractures are uncommon in the pediatric population, representing only 3% of hand and carpal fractures. 1 They can be initially radiographically occult in 12.5% to 37% of cases2,3 and can take up to 5 weeks to be visible on radiographs. 4 Missed scaphoid fractures can lead to significant complications such as nonunion, avascular necrosis (AVN), or osteoarthritis from scaphoid nonunion advanced collapse (SNAC).5,6 When a child presents with a wrist injury suspicious for a scaphoid fracture but negative radiographs, the common practice is to immobilize the wrist and repeat radiographs and clinical exam in 10 to 14 days.7,8 If the child returns at the follow-up visit with normal or equivocal radiographs but has persistent clinical tenderness in the anatomic snuffbox or over the scaphoid tubercle, this is considered a clinical scaphoid fracture, 9 and the optimal management of this injury is unclear.
The classical strategy for these patients has been to conduct serial radiographs and clinical exams every 2 weeks until: (1) a fracture is visible; or (2) the symptoms resolve.7,10 However, this can lead to unnecessary imaging, unwarranted immobilization, and multiple clinical visits, incurring costs to the healthcare system and to families.9,11-14 Furthermore, immobilization in children may have a negative impact on family and school life. 10 Pillai and Jain 11 suggest a variation to this strategy and believe that symptomatic treatment is sufficient without continuous radiographic evidence. Another option in the management of clinical scaphoid fractures is to conduct early advanced imaging, such as magnetic resonance imaging (MRI) or computed tomography (CT), to confirm or rule out injury. Evenski et al 15 suggested that early advanced imaging should be considered in children where suspicion for a scaphoid fracture persists 2 weeks from injury despite normal radiographs. Several studies in adults have suggested that the use of early MRI is cost-effective in identifying and managing these fractures,16-19 but similar studies have not been conducted in the pediatric population.
There is a paucity of literature regarding the pediatric population, and there are no clear evidence-based guidelines for the management of pediatric patients with clinical scaphoid fractures. Most scaphoid fractures in children are nondisplaced, and cast immobilization may be sufficient for these fractures. 7 At our institution, it was hypothesized that there is significant variability in the treatment of these patients. Given that there are differences in the recommendations from the literature, and that the treatment and outcomes at our institution are not well elucidated, the purpose of this study was to identify the treatment and outcomes of children presenting with a clinical scaphoid fracture at our institution.
Materials and Methods
An institutional research ethics board-approved retrospective review of patients presenting to the orthopedic or plastic surgery clinic at a pediatric tertiary care center over a 2-year period (July 2015 to July 2017) was performed. Patients with a diagnosis of an acute scaphoid fracture, wrist pain, or hand pain were identified using the International Classification of Diseases, 10th Revision (ICD-10-CA) codes (Appendix A). Patients under 18 years of age were included if there was clinical suspicion of a scaphoid fracture and 2 sets of serial x-rays 7 to 14 days apart where no obvious scaphoid fracture was apparent. Clinical suspicion was defined as physician suspicion of a scaphoid fracture based on history and physical exam with pain in the anatomic snuffbox or at the scaphoid tubercle. Patients were excluded if they presented to the emergency department >10 days after injury, if a scaphoid fracture was identified on either of the 2 sets of initial x-rays, if their wrist pain resolved by their second radiograph, or if they had a concomitant fracture.
Information was extracted by review of all records including emergency department (ED), clinic, surgical, and radiologic reports. Demographic data as well as location of fracture, final diagnosis, mechanism of injury, treatment, outcomes, and complications were recorded. Management (immobilization, need for surgery, or advanced imaging) was made on an individual patient basis by one of the 7 treating staff surgeons.
Given the poor inter-observer reliability in diagnosing scaphoid fractures by radiograph,20-22 we did not rely on only a single physician’s interpretation of a radiograph to diagnose a fracture. A patient was considered to have a fracture if both the radiologist and surgeon identified a fracture on imaging, or if one physician reported a fracture and the other reported a suspected fracture. If both the radiologist and surgeon reported the radiograph as suspicious, but no obvious fracture was seen, it was not considered a scaphoid fracture in our data. If either the radiologist or surgeon reported a fracture and the other reported no fracture, it was not considered a true scaphoid fracture.
Results
Six hundred twenty patients were identified with a diagnostic code for scaphoid fracture, hand, or wrist pain. After reviewing the medical records, 91 patients met the inclusion and exclusion criteria and had clinical suspicion of a scaphoid fracture with 2 sets of negative radiographs (Figure 1). Relevant reasons for exclusion were no wrist pain at the first clinic visit (n = 116), wrist pain not suspicious for scaphoid fracture (n = 69), or scaphoid fracture evident on first or second radiograph (n = 57). The remaining 287 patients were excluded for injuries or pain not related to the scaphoid or radial aspect of the wrist.
Inclusion of patients in study.
The mean age of patients was 13.2 years old (SD = 2.2, range: 7.8-17.7), with 35 (38.5%) males (Table 1). The most common mechanism of injury was falling from standing height (35.2%) or during sports (30.8%).
Demographics and Injury Characteristics.
At their first follow-up visit in the plastic surgery or orthopedic surgery clinic, 86 patients (95%) were immobilized for a mean duration of 5.4 weeks (SD = 3.7, range: 1-24) (Table 2). The most common immobilization was thumb spica cast used in 67 patients (78%), followed by thumb spica splint used in 8 patients (9%) (Table 2). Sixteen patients (17.5%) had advanced imaging, either CT or MRI, ordered by 6 of the 7 treating surgeons. Twelve patients (13.2%) received CT imaging at a mean duration of 8.9 weeks postinjury (SD = 6.6, range: 2-22), 2 of which were done at 3 or less weeks post-injury. Of the CTs, 10 were normal, 1 revealed a scaphoid fracture, and 1 revealed a trapezium fracture. Four patients (4.4%) received MRI at a mean duration of 6.9 weeks postinjury (SD = 2.7 range: 4-11), none of which were done at 3 or less weeks postinjury. Of the MRIs, none of the 4 patients had a true fracture: 2 were normal, 1 revealed a partial scapholunate (SL) ligament tear, and 1 revealed extensor tendinopathy.
Management of Patients.
Note. CT = computed tomography; MRI = magnetic resonance imaging; SL = scapholunate.
In total, 11 fractures (12%) of any type in and around the wrist were identified (Table 3), though only 5 patients (5.5%) were found to have a true scaphoid fracture. True scaphoid fractures were diagnosed by radiograph (4 patients) and by CT (1 patient) at a mean time of 4.5 weeks postinjury (range: 3-6). Three fractures were at the waist of the scaphoid, 1 at distal scaphoid, and 1 was at the junction of the proximal pole and the waist. The mean age of patients with a scaphoid fracture was 12.2 years (range: 11-14). Six patients were found to have other fractures, consisting of 4 distal radius fractures, 1 trapezium fracture, and 1 trapezoid fracture, diagnosed at a mean time of 3.1 weeks postinjury (range: 3-6.5). Soft tissue thumb injuries were identified in 4 (4.4%) patients and included clinical diagnoses such as UCL injuries, “thumb sprains,” or “unspecified thumb injuries.”
Final Diagnoses of Patients.
Note. CT = computed tomography.
The clinical outcomes for patients at their final visit were evaluated (Table 4). Forty-one patients (45.1%) were noted by the surgeon to be fully healed. Thirty-two (35.2%) patients still had some pain and were instructed to return as needed. Twelve patients (13.2%) still had pain at their last visit and were lost to follow-up, and 5 patients (5.5%) planned to be followed elsewhere. No patient underwent surgery.
Clinical Outcomes of Patients at Last Visit.
There were 195 sets of radiographs in total; the surgeon and radiologist disagreed on 59 (30.2%) of these images (Table 5). Forty-seven (80%) of these disagreements were regarding the first or second set of radiographs. Forty-nine (83%) of these disagreements were due to only the surgeon reporting a fracture, and 10 (17%) of these disagreements were due to only the radiologist reporting a fracture. The discordant radiographic diagnoses involved 30 patients, whose final diagnoses are reported in Table 6. Twenty-one (70%) of these patients had a final diagnosis of clinical scaphoid fracture, and the other 9 (30%) were found to have fractures: 4 (13.3%) scaphoid fractures, 4 (13.3%) radius fractures, and 1 (3.3%) trapezium fracture.
Radiograph Reporting by Surgeons and Radiologists.
Final Diagnoses of Patients (n = 30) Who Had Disagreement in Radiograph Diagnosis by Surgeon and Radiologist.
Discussion
Clinical scaphoid fractures in children present a challenge for the treating clinician. Immobilization, serial examinations, and multiple radiographs must be tempered against the reality that few may have a true scaphoid fracture. Use of limited healthcare resources and direct and indirect costs to patients and families must also be considered. Much of the current literature on clinical scaphoid fractures is based on adult populations, which is not surprising, given that scaphoid fractures represent a higher proportion of all fractures in adults (5%) 23 compared to children (0.34%). 8 As a result, there is a paucity of literature on the management of children with suspected scaphoid fractures. Our study revealed a true scaphoid fracture rate of 5.5% following 2 negative radiographs in the 2 weeks following injury.
There have been 4 previous studies on pediatric clinical scaphoid fractures that reported rates of occult scaphoid fractures rates ranging from 1.4% to 37%.2,3,15,24 These studies, however, examined patients with only 1 negative x-ray, while our study examined patients with 2 negative x-rays. Thus, our fracture rate may not be directly comparable with previous published results; however, our results are plausible. Given that the likelihood of a fracture presenting after 2 negative radiographs would presumably be lower than after only 1 negative radiograph, we hypothesize that the rate of true fracture following only 1 x-ray may be, in fact, greater than 5.5%.
In our study, 95% of patients were immobilized for a mean of 5.4 weeks. Porter et al 24 and Evenski et al 15 reported immobilization rates of 63% and 100%, respectively. These results contribute to the dilemma of how to manage pediatric patients with a clinical scaphoid fracture: there is no clear consensus on whether we should continue with immobilization and serial radiographs or obtain early advanced imaging. Performing early advanced imaging such as MRI or CT scan may help to rule out a diagnosis of scaphoid fracture, thus obviating the need for unnecessary immobilization and multiple visits. Multiple studies in adults have suggested that early MRI is cost-effective when compared to traditional follow-up and radiographs; however, cost-effectiveness of early MRI has not yet been demonstrated in children.16-19 Alternatively, while it may seem unnecessary, costly, and inconvenient to the majority of patients who do not end up having a fracture, routine immobilization seems to be the most risk-averse option. In our study, all scaphoid fractures presented within 6 weeks, which could strengthen the possibility of terminating immobilization if a fracture does not become radiographically visible within a certain time frame. Additionally, the clinical significance of these nondisplaced occult scaphoid fractures is unclear: it is unknown if the risk of nonunion and AVN is similar to the risk of scaphoid fractures that are readily apparent on initial x-rays.
Management at our institution was relatively uniform, contrary to the initial hypothesis that there was significant practice variation among the treating surgeons. Nearly all patients were immobilized. Advanced imaging at our center was used infrequently compared to previous reports: Nguyen et al 25 reported that 83% of their adult patients with suspected scaphoid fractures received a CT scan within 2 weeks of injury, and other authors have suggested pursuing advanced imaging after 2 weeks of immobilization if the diagnosis is still unclear. 15 The various results in the literature further support that there may be significant institutional practice variation in the management of these patients.
The retrospective nature of this study limits the opportunity for standardization of clinical assessments, objective outcome measures, and appropriate long-term follow-up. In addition, few patients received advanced imaging. As a result, we may be underestimating the true incidence of scaphoid fractures. The diagnosis of a scaphoid fracture, however, lacks a reference standard. 26 MRI and CT may overestimate the incidence of fractures, 27 while radiographs at 6 weeks postinjury demonstrate poor inter-rater reliability. 28 Assessment of healing was quite variable, which also reflects the variability in final diagnoses. Lack of follow-up of patients that had incomplete resolution of symptoms, furthermore, could have resulted in additional missed injuries.
Understanding the true rate of scaphoid fracture in patients with persistent signs and symptoms but normal radiographs will help direct the management of these patients. If this rate is low and there are few adverse sequelae, the need for prolonged immobilization or advanced imaging may be questioned. Patient, institution, and economic factors must be considered in order to guide decision-making for these cases.
Conclusion
The optimal management and treatment of clinical scaphoid fractures in the pediatric patient remains unknown. We found occult scaphoid fractures in 5.5% among patients with 2 consecutive negative x-rays despite clinical signs for a clinical scaphoid fracture. Our findings of a low, but not zero, true scaphoid fracture rate, radiologic interpretation disagreements, and lack of advanced imaging provide an avenue for future studies to explore these issues further. Prospective studies with larger sample sizes are necessary in order to clarify the incidence of true fracture within the pediatric clinical scaphoid population, and advanced imaging should be considered for such a study in order to better address diagnostic accuracy and inherent challenges with radiographic interpretation of the scaphoid.
Footnotes
Appendix A
ICD-10-CA Diagnosis codes: “M25.53,” “M25.54,” “M25.64,” “S60.2,” “S60.7,” “S60.8,” “S60.9,” “S62.000,” “S62.001,” “S62.18,” “S62.19,” “S62.800,” “S62.801,” “S63.000” to “S63.091,” “S63.50” to “S63.59,” “S63.70” to “S63.79,” “S69.7” to “S69.9”
Ethical Approval
This study was approved by our institutional review board.
Statement of Human and Animal Rights
No human or animal experimentation was done as part of the study.
Statement of Informed Consent
Not required given the nature of the study design.
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
Previous Presentations
The findings of this study were presented in part at the Canadian Society of Plastic Surgeons 72nd Annual Meeting, in Jasper, Alberta, June 19 through 23, 2018, and Canadian Orthopedic Association Annual Meeting in Montreal, Quebec, June 19 through 22, 2019.
