Management of displaced fractures of the waist of the scaphoid: meta-analyses of comparative studies

What Is the Optimal Method of Fixation for Scaphoid Nonunion Relative to the Location of the Lesion?

INTRODUCTION

Scaphoid nonunion is a typical complication of scaphoid fractures, with the nonunion rate varying by the location of the scaphoid. The current widely used method for treating scaphoid nonunion, which is challenging for surgeons, is the headless compression screw (HCS). Various surgical approaches, such as the scaphoid plate, have been proposed to address the problem of screw fixation; however, no consensus exists regarding the optimal treatment method. This study focused on analyzing appropriate treatment methods based on the anatomical location of the scaphoid nonunion.

METHODS

Ninety-seven patients with scaphoid nonunion were treated between 2008 and 2023. All patients underwent treatment using 1 HCS or scaphoid volar locking plate with nonvascularized bone graft from the distal radius depending on the scaphoid's location. The scaphoid angle and bone union were confirmed using radiological examinations. The clinical evaluations included range of motion, pain, grip strength, and functional wrist scores.

RESULTS

Fifty-seven patients were included in the final analysis. In the screw group, 26 patients (26/42 [62%]) obtained a bone union, and all 15 patients (15/15 [100%]) in the plate group obtained a union ( P = 0.005). In the waist group, 16 patients with screw (16/25 [64%]) and 8 using a plate (8/8 [100%]) showed bony healing. In the proximal group, 3 patients with HCS (3/9 [33%]) and 4 using plate (4/4 [100%]) showed bone union. In the distal group, 7 patients with a screw (7/8 [87%]) and 3 with the plate (3/3 [100%]) showed bone union. Significant differences were found in the waist ( P = 0.047) and proximal groups ( P = 0.026), but not in the distal group ( P = 0.521). All groups showed improved radiological angles associated with the scaphoid and better clinical outcomes postoperatively.

CONCLUSIONS

Plate fixation was overall superior to screw fixation for scaphoid nonunion, especially in the waist and proximal poles, providing better union rates and stability. For the distal group, both methods are effective, with the choice depending on the surgeon's expertise and patient factors. The results highlight the importance of the lesion's anatomical location in selecting the appropriate fixation method.

Functional and radiologic outcomes of non-displaced scaphoid waist fractures in adolescents approaching skeletal maturity: Comparison between conservative treatment and percutaneous screw fixation

BACKGROUND

Treatment of scaphoid waist fractures is generally conservative in children but surgical in adults, given the relatively high risk of non-union in adults. In adolescents, the required therapeutic strategy is less well defined. The objective of this study was to compare the radiographic and clinical parameters, and the rate of complications, between non-surgical orthopedic treatment (OT) and surgical treatment (ST) by percutaneous screw fixation of these fractures in adolescents approaching skeletal maturity.

HYPOTHESIS

ST of non-displaced scaphoid waist fractures in adolescents allows radiographic union, a functional result and a complication rate comparable to that of ST.

METHODS

This single-center retrospective study included patients who presented with a non-displaced scaphoid waist fracture, with a chronological age (CA) and a bone age (BA) between 14 and 18 years. Clinical and radiographic parameters and complications were analyzed during the trauma and at one year, including functional scores, between two groups of patients; OT and ST.

RESULTS

Thirty-seven patients had OT (63.8%) and 21 had ST (36.2%). The median CA was 16 years [14.25-16]. The median BA was 16 years [15;17] according to the Greulich and Pyle method and corresponded to R9 [R7-R10] and U7 [U7;U8] according to the Distal Radius and Ulnar (DRU) classification system. All non-unions were found in the OT group (23.4% vs. 0%, p=0.019). The duration of immobilization (8 weeks) and the number of consultations were higher after OT than ST. Functional scores were lower in patients with non-union after OT (p≤0.002) CONCLUSION: OT of scaphoid waist fractures in adolescents results in a higher rate of non-union than ST, similar to the rate found in adults. Findings from this study recommend a surgical approach by percutaneous screw fixation.

LEVEL OF EVIDENCE

III; comparative retrospective study.

Surgical Treatment of Scaphoid Fractures: Recommendations for Management

Background: Several operative treatments exist for scaphoid fractures, varying by approach (e.g., ercutaneous, volar, or dorsal), implant type (e.g., screw or Kirschner wire), and bone raft choice (e.g., none, nonvascularized, or vascularized). Many previous systematic eviews and meta-analyses have investigated outcomes following different surgicalÚpproaches, the use of vascularized versus nonvascularized bone graft for scaphoidßracture nonunions, and treatment for specific fracture patterns. However, given the advancements n scaphoid fracture treatment in recent years, there is a need for updated treatment recommendations hat would be beneficial to hand surgeons. Purpose: We present a comprehensive review of the operative treatment of scaphoid fractures based on recent literature and propose a unified treatment algorithm for managing these fractures. Methods: The English-language literature was searched from 2002 to 2023 for high evidence level (e.g., randomized trials), review, and meta-analysis articles with the following search terms: "scaphoid, "u8220"scaphoid" AND "nonunion, " and "scaphoid" AND "malunion. " Each article was creened by the authors to determine the scaphoid fracture scenario addressed and ubsequent treatment recommendations. The findings from article reviews were then rganized by scaphoid fracture types in this manuscript. Results: A total of 95 pertinent articles were ultimately selected and used as the basis for reviewing different scaphoid fracture scenarios. A treatment algorithm was then proposed based on literature review. Conclusion: This summary of the recent literature can guide hand surgeons in addressing scaphoidßractures. Future research in scaphoid fracture treatment, particularly for nonunions, would be most beneficial n the form of systematic review, meta-analysis, or multicenter prospective randomized clinical trials. Level of Evidence: IV.

Fracture Gap Closure and Reduction Are Affected by the Orientation of the Headless Compression Screw

BACKGROUND

We evaluated the impact of a variable-pitch headless screw's angle of insertion relative to the fracture plane on fracture gap closure and reduction.

METHODS

Variable-pitch, fully threaded headless screws were inserted into polyurethane blocks of "normal" bone model density using a custom jig. Separate trials were completed with a 28-mm screw placed perpendicular and oblique/longitudinal to varying fracture planes (0°, 15°, 30°, 45°, and 60°). Fluoroscopic images were taken after each turn during screw insertion and analyzed. Initial screw push-off, residual fracture gap at optimal fracture gap reduction, and malreduction were determined in each trial. Statistical analysis was performed via a 1-way analysis of variance followed by Student t tests.

RESULTS

Malreduction was found to be significantly different between the perpendicular (1.88 mm ± 1.38) and the oblique/longitudinal (0.58 mm ± 0.23) screws. The malreduction increased for the perpendicular screw as the fracture angle increased (60° > 45°=30° > 15° > 0°). Residual fracture gap at optimal fracture gap reduction was also found to be significantly different between the perpendicular (0.97 ± 0.42) and oblique/longitudinal (1.43 ± 1.14) screws. The residual fracture gap increased for the oblique/longitudinal screw as the fracture angle increased, although the oblique/longitudinal screw with a 60° fracture angle was the only configuration significantly larger than all the other configurations. Screw push-off was not found to be significantly different between the oblique/longitudinal screw and perpendicular screw trials.

CONCLUSIONS

The perpendicular screw had a larger malreduction that increased with fracture angle, whereas the oblique/longitudinal screw had a larger residual fracture gap that increased with fracture angle.

Cancellous compression bone grafting using headless screw as a strut in scaphoid nonunion by a single volar approach

PURPOSE

An array of fixation and grafting techniques for scaphoid nonunion have been described over time, achieving varied results pertaining to union and scaphoid alignment. The aim of this study was to check for union rates and correction of scaphoid parameters achieved by our technique of using screw as a strut and cancellous compression grafting harvested from the distal radius by a single volar approach.

METHODS

Retrospective analysis of all patients operated by the said technique was done from 2013 to 2019. Thirty-eight patients including 36 males and two females in the age range of 20-56 years were analyzed. Union rates, change in scaphoid alignment parameters and graft site characteristics were documented.

RESULTS

Of the patients analyzed, 5/38 were nonunions of proximal pole, 19/38 of waist and 14/38 were of distal pole which included nonunions of cystic type or with humpback deformity. Patients were followed up for an average of 22.2 months and union was achieved in all cases with a mean period of 15.7 ± 3.7 weeks. There was significant improvement in the scaphoid alignment postoperatively. One case of implant migration and one case of scaphoid nonunion advanced collapse were noted. The mean duration of donor site healing was noted to be 16.9 ± 2.5 weeks except two outliers which took longer time. There were no cases of donor site fracture or other complications.

CONCLUSION

Union rates, correction of scaphoid parameters and minimal complications justifies this technique as a novel one in the management of scaphoid nonunion at all levels, with minimal donor site morbidity and attained by the single volar approach.

Postoperative Immobilization of Scaphoid Fractures: A Comprehensive Review of the Literature

The optimal protocol for postoperative immobilization following operative treatment of scaphoid fractures remains controversial. Reports of successful management with brief postoperative immobilization suggest that earlier restoration of function may be achieved by limiting the duration of immobilization. However, the risk of nonunion and its associated complications suggest that a more conservative approach with extended immobilization could optimize fracture healing. This paper presents a thorough review of the relevant literature and summarizes the myriad postoperative immobilization protocols and their reported outcomes. Postoperative immobilization protocols and reported outcomes for displaced, comminuted, and proximal pole fractures are discussed separately. The literature is reviewed following different operative techniques, including open reduction internal fixation and percutaneous screw fixation. Vigilant postoperative care of scaphoid fractures managed surgically is warranted to monitor for signs of nonunion while attempting to regain motion and strength to the injured wrist.

Resource Utilization and the Use of Bone Stimulators among Operatively and Nonoperatively Managed Scaphoid Nonunion Patients

The prevalence of bone stimulator use among nonoperatively and operatively managed scaphoid nonunion patients is unknown. We hypothesize that bone stimulators are a relatively underutilized treatment for scaphoid nonunion patients.

Methods

We used the 2009-2017 Truven Marketscan Research Databases to identify patients with closed scaphoid fractures and performed an analysis of variance test to determine resource utilization and bone stimulator use among these patients.

Results

A total of 36,611 patients with scaphoid fractures were identified: 30,143 were managed nonoperatively and 6468 were managed operatively. Nonunion was diagnosed in 500 (1.66%) nonoperatively and in 1211 (19%) operatively managed patients. Bone stimulators were used in less than 2% of nonoperatively and operatively managed scaphoid nonunion patients.

Conclusion

Lack of trust in the technology and heterogenous (and occasionally burdensome) requirements for insurance approval are barriers to bone stimulator use; however, surgeons should examine how this technology may fit into the treatment algorithm for these difficult cases.

The Effect of Derotational Kirschner Wires on Fracture Gap Reduction With Variable-Pitch Headless Screws

PURPOSE

We evaluated the impact of angled derotational Kirschner wires (K-wires) on fracture gap reduction with variable-pitch headless screws.

METHODS

Fully threaded variable-pitch headless screws (20 and 28 mm) were inserted into "normal" bone models of polyurethane blocks. In separate trials, derotational K-wires were inserted at predetermined angles of 0°, 15°, 30°, and 40° and compared with each other, with no K-wire as a control. Fluoroscopic images taken after each screw turn were analyzed. The optimal fracture gap closure, initial screw push-off, and screw back-out gap creation were determined and compared at various derotational K-wire angles.

RESULTS

Initial screw push-off due to screw insertion and screw back-out gap creation were not significantly affected by the angle of the derotational K-wire. With a 20-mm screw, only a 40° derotational K-wire led to significantly less gap closure compared with control and with 0°, 15°, and 30° derotational K-wires. It led to an approximately 60% decrease in gap closure compared with no K-wire. With the 28-mm screw, compared with no K-wire, 15° and 30° derotational K-wires led to statistically significant decreases in gap closure (approximately 25%), whereas a 40° derotational K-wire led to an approximately 60% decrease. With the 28-mm screw, the 40° derotational K-wire also led to a statistically significant smaller gap closure when compared with 0°, 15°, and 30° derotational K-wires.

CONCLUSIONS

A derotational K-wire placed in parallel to the planned trajectory of a headless compression screw does not affect fracture gap closure. With greater angulation of the derotational K-wire, the fracture gap is still closed, but less tightly.

CLINICAL RELEVANCE

Derotational K-wires can help prevent fracture fragment rotation during headless compression screw insertion. At small deviations from parallel (≤30°), fracture gap closure achieved by the screw is minimally affected. At greater angles (ie, 40°), fracture gap closure may be substantially reduced, preventing fracture compression.

Double-Screw Osteosynthesis in an Unstable Scaphoid Fracture Model: A Biomechanical Comparison of Two Screw Configurations

PURPOSE

Although there is evidence that a single headless compression screw is sufficient for fixation of most scaphoid fractures, double-screw osteosynthesis has been shown to result in higher failure strength and stiffness than a single screw. However, the biomechanical effect of different screw configurations has not been determined.

METHODS

A standardized unstable fracture model was produced in 28 cadaveric scaphoids. Specimens were randomly allocated to 1 of 2 fixation groups using 2 internal compression screws positioned in either the sagittal or coronal plane. A specimen-specific 3-dimensionally-printed customized screw placement and osteotomy device was developed using computer-aided design-generated models derived from computed tomography scan data of each individual scaphoid. Load to failure and stiffness of the repair constructs were evaluated using a mechanical testing system.

RESULTS

There were no significant differences in size, weight, and density between the scaphoid specimens. The average distance between screws was significantly greater in the sagittal group than in the coronal group. There were no significant differences between the coronal and sagittal aligned double screws in load to 2 mm displacement (mean coronal 180.9 ± 109.7 N; mean sagittal 156.0 ± 85.8 N), load to failure (mean coronal 275.9 ± 150.6 N; mean sagittal 248.0 ± 109.5 N), stiffness (mean coronal 111.7 ± 67.3 N/mm; mean sagittal 101.2 ± 45.1 N/mm), and energy absorption (mean coronal 472.6 ± 261.4 mJ; mean sagittal 443.5 ± 272.7 mJ).

CONCLUSIONS

There are no significant biomechanical differences between the sagittal or coronal aligned double headless compression screws in a scaphoid fracture model with bone loss.

CLINICAL RELEVANCE

In cases where double-screw fixation of the scaphoid is being considered, the placement of double screws can be at the discretion of the surgeon, and can be dictated by ease of access, surgical preference, and fracture orientation.

Comparison of Two Different Percutaneous Screw Fixations for Treating Herbert B2-Type Acute Scaphoid Fractures

OBJECTIVE

Scaphoid fracture was the most common carpal fracture and the most challenging. The purpose of this study was to investigate and compare the clinical effects of closed reduction and percutaneous cannulated screw internal fixation under fluoroscopy and arthroscopy-assisted percutaneous cannulated screw internal fixation in the treatment of Herbert B2-type of acute scaphoid fractures.

METHODS

A retrospective controlled study was conducted on 29 patients with Herbert B2-type acute scaphoid fracture with a displacement of >1 mm admitted to our hospital from January 2017 to June 2021. Patients were divided into two groups, 11 patients were treated with closed reduction percutaneous cannulated screw internal fixation under fluoroscopy and 18 patients were treated with percutaneous cannulated screw internal fixation assisted by arthroscopy. The operative time, intraoperative fluoroscopy times, fracture healing time, complications, and postoperative wrist function score of the two groups were compared.

RESULTS

All patients were followed up for 6-18 months (mean follow-up duration: 10.38 ± 2.69 months). The respective operation times in the arthroscopy group and fluoroscopy group was 51.50 ± 6.69 min and 56.73 ± 11.48 min, respectively (p > 0.05). The number of fluoroscopies performed in the arthroscopy group was (6.83 ± 1.30), which was less than that in the fluoroscopy group (10.91 ± 2.62) (p < 0.05). All fractures in the arthroscopy group healed after the operation, and the fracture healing time was 11.44 ± 1.25W. Ten patients in the fluoroscopy group healed. The fracture healing time was 13.60 ± 2.32 W. The fracture healing time in arthroscopy group was less than that in the fluoroscopy group (p < 0.05). One patient in the fluoroscopy group had nonunion and healed after bone grafting and internal fixation. At the postoperative 6-month follow-up, the modified Mayo wrist function score was used to evaluate the clinical results. The wrist function score of patients in the arthroscopy group was 90 (85, 95), which was >80 (80, 90) in the fluoroscopy group (z = 2.74, p < 0.05).

CONCLUSION

For Herbert B2-type acute scaphoid fracture with fracture displacement > 1 mm, the arthroscopy-assisted percutaneous cannulated screw internal fixation has less fluoroscopy times, short fracture healing time, and good recovery effect of wrist function compared to the fluoroscopy.

Clinical and Epidemiological Features of Scaphoid Fracture Nonunion: A Hospital-Based Study in Beijing, China

Objective

Studies exploring the epidemiological characteristics of scaphoid fracture nonunion are important to understand the causes and lead to effective prevention strategy. However, such knowledge is limited especially in China. This study aims to reveal the clinical and epidemiological features of scaphoid fracture nonunion in Chinese patients.

Methods

This was a retrospective study, which was based on patients with scaphoid fracture nonunion treated in a Chinese national orthopedic referral center from 1 August 2009 to 1 August 2020. The basic demographic and clinical characteristics, including gender, age at diagnosis of scaphoid fracture nonunion, dominant hand, the location of fracture, the side, the causes of the injury, age of the injury, age of the treatment for scaphoid fracture nonunion, and the delay period, were retrieved from the medical records. The patients were divided into a non‐delay group and a delay group based on whether they had visited the doctor within 1 month after the injury. Scaphoid fracture was classified into the proximal, waist, and distal fractures according to the location. The t‐test or Mann–Whitney U test was used to compare the difference between groups when the dependent variable is continuous, while a chi‐square test was used when the dependent variable is categorical.

Results

A total of 363 patients were included in this study. The mean age at the diagnosis of scaphoid fracture nonunion was 32 (ranging from 14 to 78). Waist fracture nonunion (76.5%) was most common. Among the 169 patients who sought medical care within 1 month after the injury (non‐delay group), more than half (90 cases) were misdiagnosed. 23 cases could not recall the injury, so the time of delay could not be determined. Among the 171 patients who did not seek medical care for acute injury (delay group), the average time was 52 months between the initial injury and the treatment. The proportion of waist nonunions was higher among patients in the delay group than that in the non‐delay group.

Conclusions

Nonunion of scaphoid fracture is caused mainly by delayed treatment and misdiagnosis in China, suggesting that timely treatment and improved diagnosis could lower the prevalence. The fracture location may be a factor contributing to the delaying of seeking medical care.

Acute scaphoid fractures: making decisions for treating a troublesome bone

Seven aspects of the management of acute scaphoid fractures are open to debate: Diagnosis of true fractures among suspected fractures, assessment of fracture displacement, cast immobilization strategies, the role of surgical fixation, proximal pole fractures, assessment of union, and the underlying objective of treatment. We reviewed current evidence, and our varied interpretations of it, to highlight areas of uncertainty where more evidence might be helpful.

The influence of fracture location and comminution on acute scaphoid fracture displacement: three-dimensional CT analysis

We aimed to assess the influence of fracture location and comminution on acute scaphoid fracture displacement using three-dimensional CT. CT scans of 51 adults with an acute scaphoid fracture were included. Three-dimensional CT was used to assess fracture location, comminution and displacement. Fracture location was expressed as the height of the cortical breach on the volar and dorsal side of the scaphoid relative to total scaphoid length (%), corresponding to the fracture's entry and exit point, respectively. We found a near-linear relation between dorsal fracture location and displacement. As dorsal fracture location became more distal, translation (ulnar, proximal, volar) and angulation (flexion, pronation) of the distal fragment relative to the proximal fragment increased. Comminuted fractures had more displacement. Dorsal fracture location predictably dictates the direction of translation and angulation in displaced scaphoid fractures. Surgeon attention to dorsal fracture location can help identify displacement patterns and provide guidance in adequately reducing a displaced scaphoid fracture.Level of evidence: III.

A meta-analysis of union rate after proximal scaphoid fractures: terminology matters

Heterogeneity in the anatomical definition of 'proximal' affects the comparison of outcomes of these scaphoid fractures. This study aims to review published outcomes of all variants to determine both, differences in terminology, and union rate based upon definition. A literature search was conducted to identify articles that reported descriptions and union rate of all acute (<8 weeks of injury) proximal scaphoid fractures in adult patients (>16 years old). Proximal fractures were grouped as reported ('third', 'pole', 'fifth' or 'undefined'). The data were pooled using a fixed-effects method, and a meta-analysis was conducted to compare relative risk (RR) of non-union against non-proximal fractures. Qualitative analysis of 12 articles included three main definitions: 'proximal' (1 article), 'proximal third' (3 articles), and 'proximal pole' (8 articles). Only 6 articles adopted a specific anatomical or ratio description. In a pooled meta-analysis of union rates (15 articles), 'proximal third' and 'proximal pole' fractures demonstrated a relative risk (RR) of non-union of 2.3 and 3.4 in comparison to non-proximal fractures, respectively. Operative management yielded lower non-union rates than non-operative for all fracture types (6% vs. 18%). In conclusion, non-union risk varies depending on definition, with non-standardised classifications adding heterogeneity to reported outcomes. We recommend an approach utilizing fixed anatomical landmarks on plain radiographs (referencing scaphoid length and scapho-capitate joint) to standardise reporting of proximal fracture union in future studies. Abbreviations: CI: confidence intervals; CT: computer tomography; Df: degrees of freedom; DL: dersimonian and laird estimator; MRI: magnetic resonance imaging; NICE: national institute for health and care excellence; OTA: orthopaedic trauma association; PA: posterior-anterior; PRISMA: preferred reporting items for systematic reviews and meta analyses; RCT: randomised controlled trial; RR: relative risk; SNAC: scaphoid non-union advanced collapse; UK: United Kingdom.

Management of acute scaphoid fractures: a pragmatic approach for the non-specialist

Scaphoid fractures are common and can cause significant morbidity if treated incorrectly. Thus, a working knowledge of the initial assessment and management of scaphoid fractures by non-specialists is crucial to allow quick diagnosis and avoid potentially catastrophic complications of scaphoid fracture. This article summarises the anatomy of the scaphoid, discusses methods to assess for scaphoid fractures and delineates management plans (conservative or operative) for fractures of the scaphoid based on location of vascular compromise. This article can also help the clinician predict which fractures may not unite with conservative management and therefore need referral to a specialist orthopaedic surgeon for possible surgery.

Percutaneous fixation of acute scaphoid waist fractures: Long-term patient-reported functional outcomes and satisfaction at a mean of 11 years following surgery

The aim of this study was to report the long-term functional outcomes and complication rates following early percutaneous fixation of acute fractures of the scaphoid. A trauma database was searched to identify all skeletally-mature patients with an undisplaced or minimally-displaced scaphoid waist fracture managed with early percutaneous retrograde screw fixation over a thirteen-year period from 1997-2010. Medical records were retrospectively reviewed, and complications documented. Long-term follow-up was by a questionnaire-based review. The Patient-Rated Wrist Evaluation (PRWE) was the primary outcome measure. Secondary outcomes included the Quick version of the Disability of the Arm, Shoulder and Hand score (QuickDASH), the EuroQol 5-dimensions score (EQ-5D-5L), and complications. During the study period 114 patients underwent this procedure. The mean age was 28 years (range 17-62) and 97 patients (85%) were male. The median time from injury to surgery was nine days (range 1-27). Twelve patients (11%) reported a complication, all of whom required repeat surgical intervention (six revision ORIF for non-union, five elective removal of hardware, one early revision fixation due to screw impingement). Long-term outcome data was available for 77 patients (68%) at mean follow-up of 11.4 years (range 6.4-19.8). The median PRWE was 0 (IQR 0-7.5), median QuickDASH 0 (IQR 0-4.5) and median EQ-5D-5L 1.0 (IQR 0.837-1.0). There were 97% (n = 74) patients satisfied with their outcome. Early percutaneous fixation of acute non-displaced or minimally displaced scaphoid fractures results in good long-term patient reported outcomes and health-related quality of life. Although comparable with previous studies, the overall surgical reintervention rate is notable and can result in inferior outcomes. LEVEL OF EVIDENCE: Therapeutic level III (Retrospective Cohort Study).

Surgical fixation compared with cast immobilisation for adults with a bicortical fracture of the scaphoid waist: the SWIFFT RCT

BACKGROUND

Scaphoid fractures account for 90% of carpal fractures and occur predominantly in young men. Immediate surgical fixation of this fracture has increased.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of surgical fixation with cast treatment and early fixation in adults with scaphoid waist fractures that fail to unite.

DESIGN

Multicentre, pragmatic, open-label, parallel two-arm randomised controlled trial with an economic evaluation and a nested qualitative study.

SETTING

Orthopaedic departments of 31 hospitals in England and Wales recruited from July 2013, with final follow-up in September 2017.

PARTICIPANTS

Adults (aged ≥ 16 years) presenting within 2 weeks of injury with a clear, bicortical fracture of the scaphoid waist on plain radiographs.

INTERVENTIONS

Early surgical fixation using Conformité Européenne-marked headless compression screws. Below-elbow cast immobilisation for 6-10 weeks and urgent fixation of confirmed non-union.

MAIN OUTCOME MEASURES

The primary outcome and end point was the Patient-Rated Wrist Evaluation total score at 52 weeks, with a clinically relevant difference of 6 points. Secondary outcomes included Patient-Rated Wrist Evaluation pain and function subscales, Short Form questionnaire 12-items, bone union, range of movement, grip strength, complications and return to work.

RESULTS

The mean age of 439 participants was 33 years; 363 participants were male (83%) and 269 participants had an undisplaced fracture (61%). The primary analysis was on 408 participants with valid Patient-Rated Wrist Evaluation outcome data for at least one post-randomisation time point (surgery, n = 203 of 219; cast, n = 205 of 220). There was no clinically relevant difference in the Patient-Rated Wrist Evaluation total score at 52 weeks: the mean score in the cast group was 14.0 (95% confidence interval 11.3 to 16.6) and in the surgery group was 11.9 (95% confidence interval 9.2 to 14.5), with an adjusted mean difference of -2.1 in favour of surgery (95% confidence interval -5.8 to 1.6; p = 0.27). The non-union rate was low (surgery group, n = 1; cast group, n = 4). Eight participants in the surgery group had a total of 11 reoperations and one participant in the cast group required a reoperation for non-union. The base-case economic analysis at 52 weeks found that surgery cost £1295 per patient more (95% confidence interval £1084 to £1504) than cast treatment. The base-case analysis of a lifetime-extrapolated model confirmed that the cast treatment pathway was more cost-effective. The nested qualitative study identified patients' desire to have a 'sense of recovering', which surgeons should address at the outset.

LIMITATION

There were 17 participants who had initial cast treatment and surgery for confirmed non-union, which in 14 cases was within 6 months from randomisation and in three cases was after 6 months. Three of the four participants in the cast group who had a non-union at 52 weeks were not offered surgery.

CONCLUSIONS

Adult patients with an undisplaced or minimally displaced scaphoid waist fracture should have cast immobilisation and suspected non-unions immediately confirmed and urgently fixed. Patients should be followed up at 5 years to investigate the effect of partial union, degenerative arthritis, malunion and screw problems on their quality of life.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN67901257.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 52. See the NIHR Journals Library website for further project information.

Conservative treatment for fractures of the scaphoid

This review article aims to discuss the indications, techniques, outcomes, and complications of non-operative management of scaphoid fractures.

Which Headless Compression Screw Produces the Highest Interfragmentary Compression Force in Scaphoid Fracture?

BACKGROUND

Interfragmentary compression at the fracture site facilitates healing. Headless compression screws used to treat scaphoid fractures can be grouped as shank screws, conical tapered screws and double component screws. There has been no meta-analysis of biomechanical studies to compare interfragmentary compression produced by the above screws.

METHODS

A computerised search of Pubmed, Embase and OVID database was undertaken to identify the studies. We estimated the weighted mean difference of interfragmentary compression (in Newton) with 95% confidence intervals. Random effects model was selected for meta-analysis.

RESULTS

The pooled estimate of nine studies demonstrated that conical tapered screw produced significantly higher interfragmentary compression force compared to the shank screw (WMD 19.96, 95% CI 11.2-28.8, p < 0.0001, I ² = 99%). The pooled estimate of four studies demonstrated that dual component screw produced significantly higher interfragmentary compression force compared to the shank screw (WMD 16.93, 95% CI 12.3-21.6, p < 0.0001, I ² = 97.7%). The pooled estimate of four studies showed that there was no significant difference in the interfragmentary compression force generated by either conical tapered screw or dual component screw (WMD 3.93, 95% CI - 8.3 to 16.2, p = 0.53, I ² = 99.7%). There was evidence of minimal publication bias.

CONCLUSION

Conical tapered screws and dual component screws produced statistically significant higher interfragmentary compression force at the scaphoid fracture site compared to shank screws. There was no difference in the compression force generated by either conical tapered screw or dual component screw.

Acute scaphoid fractures: guidelines for diagnosis and treatment

In cases of suspected scaphoid fracture where the initial radiographs are negative, a supplementary MRI, or alternatively CT, should be carried out within three to five days.

Fracture classification, assessment of dislocation as well as evaluation of fracture healing is best done on CT with reconstructions in the coronal and sagittal planes, following the longitudinal axis of the scaphoid.

After adequate conservative management, union is achieved at six weeks for approximately 90% of non-displaced or minimally displaced (≤ 0.5 mm) scaphoid waist fractures.

Scaphoid waist fractures with moderate displacement (0.5–1.5 mm) can be treated conservatively, but require prolonged cast immobilization for approximately eight to ten weeks.

Internal fixation is recommended for all scaphoid waist fractures with dislocation ≥ 1.5 mm.

Distal scaphoid fractures can be treated conservatively. The majority heal uneventfully after four to six weeks of immobilization, depending on fracture type.

In general, proximal scaphoid fractures should be treated with internal fixation.

Cite this article: EFORT Open Rev 2020;5:96-103. DOI: 10.1302/2058-5241.5.190025

The epidemiology of scaphoid fractures in Sweden: a nationwide registry study

The epidemiology of scaphoid fractures has been described in limited populations, and incidence reports have been inconsistent. We investigated the nationwide incidence of scaphoid fractures by evaluating data on 34,377 patients in the Swedish National Patient Register for the years 2006-2015 regarding diagnosis, age, sex and treatment. The data were validated in 300 random patients, and incidence rates were adjusted accordingly. Forty-one per cent of the initially diagnosed fractures were false positives. The adjusted true fracture incidence rate was 22 per 100,000 person-years. During the decade studied incidence rates decreased in younger men and increased in middle-aged women. The incidence of surgical treatment vs. non-operative treatment did not change over time. Men were treated surgically more often than women (6% vs. 3%) and had a greater risk for nonunion (3% vs. 1%).

Managing the Athlete with a Scaphoid Fracture

Most minimally displaced scaphoid fractures and all displaced scaphoid fractures in elite athletes are treated with early fixation to maximally expedite the return to full function. Computed tomographic (CT) scans are recommended in all scaphoid fractures to facilitate a complete understanding of fracture anatomy and to allow for optimal screw placement. Screw placement is important to maximize healing capacity of the fracture and allow for return to sport. Postoperative CT scans can be helpful to evaluate the extent of healing and may allow patients to return to play sooner.

Outcomes of Unstable Scaphoid Nonunion With Segmental Defect Treated With Plate Fixation and Autogenous Cancellous Graft

PURPOSE

Treatment of scaphoid nonunion with a segmental defect presents a challenging clinical problem. Various techniques have been proposed, often involving structural grafting with vascularized and nonvascularized bone. The authors hypothesize that satisfactory clinical and radiographic outcomes are possible with a relatively simplified technique of volar plate fixation with autogenous, purely cancellous graft.

METHODS

The authors performed a retrospective review of 34 patients with scaphoid nonunions with segmental defects, treated with plate fixation and purely cancellous bone grafting. Cases with avascular necrosis were excluded. Surgical management included a volar incision, reduction, bone grafting from the ipsilateral distal radius and/or olecranon, and application of a volar locking plate. Postoperative outcome measures included time to union based on computed tomography, return to work and sports, patient-reported pain and disability scores, grip strength, and range of motion.

RESULTS

Thirty-four patients with an average age of 31 years (range, 16-55 years) were treated with volar plate fixation and cancellous grafting, an average of 34 months after initial injury. Twenty-six patients (76%) were treated for nonunion at the scaphoid waist, 7 (21%) at the proximal pole, and 1 (3%) at the distal pole. Mean final follow-up was 18.7 months (range, 12-34 months). When union was defined by computed tomography evidence of healing, 2 (6%) scaphoids healed by 6 weeks after surgery, 28 (82%) healed by 12 weeks, and 100% healed by 18 weeks. Mean Disabilities of the Arm, Shoulder, and Hand score improved from 27.1 ± 7.3 before surgery to 11.8 ± 5.8 after surgery. Grip strength, corrected for hand dominance, improved from 77.5% of the nonsurgical side before surgery to 90.5% after surgery. All employed patients returned to work, although 3 (9%) did not return to full capacity.

CONCLUSIONS

The combination of scaphoid plate fixation and pure cancellous bone grafting for scaphoid nonunion with segmental defects yields reliable union rates and good patient outcomes. Autogenous cancellous grafting may be an alternative to more technically demanding or morbid grafting procedures for the treatment of scaphoid nonunion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

HOW SCAPHOID FRACTURES ARE TREATED IN BRAZIL

OBJECTIVE

To verify how hand surgeons manage scaphoid fractures and their complications.

METHODS

Two hundred questionnaires were distributed during the 36^th Brazilian Hand Surgery Congress (2016).

RESULTS

On suspicion of fracture without radiographic confirmation, 57% of surgeons request a CT or MRI scan, while 43% opt for immobilization and consecutive radiographs. In stable fractures the preference was for treatment with plaster cast. In fractures with no scaphoid waist displacement, 33% opt for percutaneous fixation. In displaced waist or proximal pole fractures, 66% and 99.4%, respectively, opted for surgical treatment. Most surgeons treat waist nonunion with a nonvascularized bone graft. When absorption at the site of nonunion is greater than 4 mm, 50% prefer to use iliac graft and screw fixation. In proximal pole nonunion, the Zaidemberg technique is preferred by 64%. More experienced surgeons are more likely to request tests in occult fractures (63.9% versus 47.6%; p=0.04), and tend to recommend surgery for distal third fractures more frequently (16.4% versus 4.7%; p=0.02).

CONCLUSIONS

We have provided an overview of treatment preferences for scaphoid fractures. It should be noted that more experienced surgeons are more likely to request additional tests for occult fractures and to recommend surgical treatment of distal third fractures. Level of Evidence IV, Cross-sectional survey.

Interobserver Variability of the Diagnosis of Scaphoid Proximal Pole Fractures

Purpose  Fractures of the proximal pole of the scaphoid are prone to adverse outcomes such as nonunion and avascular necrosis. Distinction of scaphoid proximal pole fractures from waist fractures is important for management but it is unclear if the distinction is reliable. Methods  A consecutive series of 29 scaphoid fractures from one tertiary hospital was collected consisting of 5 scaphoid proximal pole and 24 scaphoid waist fractures. Fifty-seven members of the Science of Variation Group (SOVG) were randomized to diagnose fracture location and displacement by using radiographs alone or radiographs and a computed tomography (CT) scan. Results  Observers reviewing radiographs alone and observers reviewing radiographs and CT scans both had substantial agreement on fracture location (κ = 0.82 and κ = 0.80, respectively; p  = 0.54). Both groups had only fair agreement on fracture displacement (κ = 0.28 and κ = 0.35, respectively; p  = 0.029). Conclusion  Proximal pole fractures are sufficiently distinct from proximal waist fractures that CT does not improve reliability of diagnosis. Level of Evidence  Level IV interobserver reliability case-control study.

Importance of Computed Tomography in Determining Displacement in Scaphoid Fractures

Background  Displaced scaphoid fractures have a relatively high rate of nonunion. Detection of displacement is vital in limiting the risk of nonunion when treating scaphoid fractures. Questions/Purpose  We evaluated the ability to diagnose displacement on radiographs and computed tomography (CT), hypothesizing that displacement is underestimated in assessing scaphoid fracture by radiograph compared with CT. Materials and Methods  Thirty-five preoperative radiographs and CT scans of acute scaphoid fractures were evaluated by two blinded observers. Displacement and angular deformity were measured, and the fracture was judged as displaced or nondisplaced. Scapholunate, radiolunate, and intrascaphoid angles were measured. Radiograph and CT measurements between nondisplaced and displaced fractures were compared. Intraobserver reliability was measured. Results   Reader 1 identified 12 fractures as nondisplaced on radiograph, but displaced on CT (34%). Reader 2 identified 9 fractures as nondisplaced on radiograph, but displaced on CT (26%). For displaced fractures, the mean intrascaphoid angle was over three times greater when measured on CT than on radiograph (56 vs. 16 degrees). Scapholunate angle >65 degrees and radiolunate angle >16 degrees were significantly associated with displacement on CT. Interobserver reliability for diagnosing displacement was perfect on CT but less reliable on radiograph. Conclusion  Scaphoid fracture displacement on CT was identified in 26 to 34% of fractures that were nondisplaced on radiograph, confirming that radiographic evaluation alone underestimates displacement. These results underscore the importance of CT scan in determining displacement and angular deformity when evaluating scaphoid fractures, as it may alter the decision on treatment and surgical approach to the fracture. We recommend considering CT scan to evaluate all scaphoid fractures. Level of Evidence  Level III.

Angular Stable Miniplate Fixation of Chronic Unstable Scaphoid Nonunion

Background  Around 5 to 15% of all scaphoid fractures result in nonunion. Treatment of long-lasting scaphoid nonunion remains a challenge for the treating surgeon. Healing of scaphoid nonunion is essential for prevention of scaphoid nonunion advanced collapse and the subsequent predictable pattern of radiocarpal osteoarthritis. Purpose  The purpose of this study was to investigate the feasibility of fixation of the scaphoid nonunion with a volar angular stable miniplate and cancellous bone grafting. We hypothesized that this technique could be successful, even in patients with previous surgery for nonunion and in patients with a long duration of nonunion. Patients and Methods  A total of 21 patients enrolled in a single-center prospective cohort study. Healing of nonunion was assessed on multiplanar computed tomography scan of the wrist at a 3-month interval. Functional outcome was assessed by measuring grip strength, range of motion, and by means of the patient-rated wrist and hand evaluation (PRWHE) questionnaire. Results  During follow-up, 19 out of 21 patients (90%) showed radiological healing of the nonunion. The range of motion did not improve significantly. Postoperative PRWHE scores decreased by 34 points. Healing occurred regardless of the length of time of the nonunion (range: 6-183 months) and regardless of previous surgery (38% of patients). Conclusion  Volar angular stable miniplate fixation with autologous cancellous bone grafting is a successful technique for the treatment of chronic unstable scaphoid nonunion, even in patients with long-lasting nonunion and in patients who underwent previous surgery for a scaphoid fracture. Rotational interfragmentary stability might be an important determining factor for the successful treatment of unstable scaphoid nonunion. Level of Evidence  Level IV.

A novel percutaneous achievement and maintenance of reduction and screw fixation for acute displaced scaphoid fractures: minimum two-year follow-up

PURPOSE

The purpose of this study was to introduce a novel method of percutaneous achievement and maintenance of reduction for acute displaced scaphoid fractures and evaluate the feasibility of this method in treating acute displaced scaphoid fractures as well as explore its indications.

METHODS

From February 2012 to March 2014, 15 patients with acute displaced scaphoid fractures were treated with our technique. Two Kirschner wires were used to achieve and maintain the reduction of the scaphoid fractures throughout the entire process of the traditional percutaneous screw fixation process. The following parameters including function scores according to modified Mayo wrist scoring system, range of motion (ROM) of the wrist, grip strength, pinch strength, healing time, time to return to work, and final outcomes were recorded.

RESULT

All patients were followed up with a mean period of 2.5 years (range, 2-3.5 years). All fractures healed with a mean of 9.3 weeks (range, 7-11.5 weeks). All patients returned to pre-injury level of activity within six weeks. The functional scores averaged 90.3 (range, 80-100). ROM of the wrist was equal to that of the contralateral side at three months postoperatively. Grip strength and pinch strength compared with contralateral were 98% and 92%, respectively. All were satisfied with the final outcomes.

CONCLUSIONS

Our technique is successfully performed in acute displaced scaphoid fractures resulting in shortened immobilization and prompt functional recovery. It broadens the indications of the percutaneous method, which means the advantages of the percutaneous method are maximally reserved whilst the drawbacks of open reduction were avoided.

Clinical and Radiologic Outcomes After Scaphoid Fracture: Injury and Treatment Patterns in National Football League Combine Athletes Between 2009 and 2014

PURPOSE

To report on the clinical and radiologic outcomes and complications after surgical treatment in National Football League (NFL) Combine athletes with a history of a scaphoid fracture.

METHODS

The medical records of 2,285 athletes participating in the NFL Combine from 2009 to 2015 were evaluated for a history of scaphoid, hand, or wrist injury. Clinical outcomes, including grip strength, pinch test, range of motion, and presence of pain and stiffness, were recorded. Imaging studies were evaluated for the percentage of healing, fixation treatment type, hardware complications, radiographic deformity, and presence of osteoarthritis.

RESULTS

Of the 2,285 athletes evaluated, 56 presented with a history of a scaphoid fracture. Most fractures were in the middle and proximal aspects of the scaphoid. Of the scaphoid fractures, 76% (43 players) were treated with screw fixation. Of the athletes, 36 (72%) had normal range of motion of the affected wrist, 52 (93%) reported no pain, and 44 (83%) reported no stiffness in the affected wrist. The grip strength and pinch strength were 91% and 96%, respectively, of the uninjured side. The fracture was healed in 75% of the cases; however, 34% had degenerative changes. Hardware complications were found in 15% of the athletes.

CONCLUSIONS

Good clinical outcomes can be achieved after scaphoid fractures in prospective NFL athletes. However, the rates of nonunion (25%), degenerative changes (34%), and hardware complications (15%) in this study suggest the need for close postoperative radiographic follow-up in this population of patients because their athletic demands may lead to higher rates of the aforementioned complications.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Treatment of Scaphoid Fractures: European Approaches

Scaphoid fractures account for 2% of all fractures. In Europe, the incidence is 12.4/100,000/y. This article focuses on the European perspective on understanding and management of these injuries. These fractures occur in young, active patients. The aim of treatment is union. Osteoarthritis is almost inevitable if the fracture does not unite. Cast immobilization is the treatment of choice in occult or stable fractures with 90% to 95% healing. Acute/primary surgery may be considered in some patients. The European literature stresses the importance of taking the patient's wishes into consideration after careful counseling about alternative treatment methods.

Percutaneous Treatment of Unstable Scaphoid Waist Fractures

BACKGROUND

Percutaneous techniques have been described for the treatment of nondisplaced scaphoid fractures, although less information has been reported about outcomes for unstable, displaced fractures. The aim of this study was to evaluate the union and complication rates following manual closed reduction and percutaneous screw placement for a consecutive series of unstable, displaced scaphoid fractures.

METHODS

A total of 28 patients (average age, 27 years; 22 male/6 female) were treated for isolated unstable displaced scaphoid waist fractures. Closed reduction and percutaneous headless, compression screw fixation was successfully performed in 14 patients (average age, 32 years; 10 male/4 female), and the remaining 14 patients required open reduction. Patients who underwent percutaneous treatment were followed for radiographic fracture union and clinical outcomes.

RESULTS

Thirteen of 14 fractures (93%) had clinical and radiographic evidence of bone union at an average of 2.8 months postoperatively. Average visual analog pain score at the time of union was 0.9. The average Quick Disability of the Arm, Shoulder, and Hand score at 2.5 years follow-up (range, 1.5-8.3 years) was 9.6 (range, 0.0-27.3). Complications included 1 case of nonunion and 1 case of intraoperative Kirschner wire breakage.

CONCLUSIONS

Manual closed reduction followed by percutaneous headless, compression screw fixation was possible in 50% of patients who presented with acute unstable, displaced scaphoid fractures. This technique appears to be a safe and effective method when a manual reduction is possible, and it may offer a less invasive option when compared with a standard open technique.

Expediting Professional Athletes' Return to Competition

Return-to-play (RTP) decisions often represent a challenge to physicians caring for athletes. The multifaceted and unique nature of each RTP decision makes standardization of the decision-making process impossible and demands of the physician thoughtful consideration of all competing interests and variables. Such difficult medical decisions are further complicated by unique ethical and legal considerations. Although no concrete RTP recommendations are available, the consensus of experienced team physicians and knowledge of the rules and regulations that apply to RTP are helpful guides to treating the various upper extremity injuries that occur in elite athletes.

Scaphoid fracture: Bone marrow edema detected with dual-energy CT virtual non-calcium images and confirmed with MRI

We aimed to determine whether bone marrow edema (BME) in acute traumatic scaphoid fracture could be demonstrated with dual-energy CT (DECT) using MRI as the gold standard. In recent years, virtual non-calcium (VNCa) images have been used to demonstrate BME in trauma cases, for example, in vertebral compression fractures, hip trauma to detect occult fractures and knee fractures. We present three cases of acute scaphoid trauma. Two patients had subtle or invisible fractures on x-ray and conventional CT images, while DECT VNCa images clearly visualized the BME, which was confirmed by MRI. One patient had negative findings on both VNCa and MRI images. The DECT VNCa algorithm is a promising technique to demonstrate BME in scaphoid fractures, with potential for increasing the diagnostic value of CT in this type of injury.

Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) protocol: a pragmatic multi-centre randomised controlled trial of cast treatment versus surgical fixation for the treatment of bi-cortical, minimally displaced fractures of the scaphoid waist in adults

Background

A scaphoid fracture is the most common type of carpal fracture affecting young active people. The optimal management of this fracture is uncertain. When treated with a cast, 88 to 90 % of these fractures unite; however, for the remaining 10-12 % the non-union almost invariably leads to arthritis. The alternative is surgery to fix the scaphoid with a screw at the outset.

Methods/Design

We will conduct a randomised controlled trial (RCT) of 438 adult patients with a “clear” and “bicortical” scaphoid waist fracture on plain radiographs to evaluate the clinical effectiveness and cost-effectiveness of plaster cast treatment (with fixation of those that fail to unite) versus early surgical fixation. The plaster cast treatment will be immobilisation in a below elbow cast for 6 to 10 weeks followed by mobilisation. If non-union is confirmed on plain radiographs and/or Computerised Tomogram at 6 to 12 weeks, then urgent surgical fixation will be performed. This is being compared with immediate surgical fixation with surgeons using their preferred technique and implant. These treatments will be undertaken in trauma units across the United Kingdom. The primary outcome and end-point will be the Patient Rated Wrist Evaluation (a patient self-reported assessment of wrist pain and function) at 52 weeks and also measured at 6, 12, 26 weeks and 5 years. Secondary outcomes include an assessment of radiological union of the fracture; quality of life; recovery of wrist range and strength; and complications. We will also qualitatively investigate patient experiences of their treatment.

Discussion

Scaphoid fractures are an important public health problem as they predominantly affect young active individuals in the more productive working years of their lives. Non-union, if untreated, can lead to arthritis which can disable patients at a very young age. There is a rapidly increasing trend for immediate surgical fixation of these fractures but there is insufficient evidence from existing RCTs to support this. The SWIFFT Trial is a rigorously designed and adequately powered study which aims to contribute to the evidence-base to inform clinical decisions for the treatment of this common fracture in adults.

Trial registration

The trial is registered with the International Standard Randomised Controlled Trial Register (ISRCTN67901257). Date registration assigned was 13/02/2013.

Usefulness of dynamic contrast-enhanced MRI in the evaluation of the viability of acute scaphoid fracture

OBJECTIVE

To evaluate the usefulness of dynamic gadolinium-enhanced magnetic resonance imaging (MRI) for assessing the viability of the proximal pole of the scaphoid in patients with acute scaphoid fractures.

METHODS

Eighteen consecutive patients with acute scaphoid fracture who underwent dynamic gadolinium-enhanced MRI 7 days or less before surgery were prospectively included between August 2011 and December 2012. All patients underwent MR imaging with unenhanced images, enhanced images, and dynamic enhanced images. A radiologist first classified the MRI results as necrotic or viable based on T1- and T2-weighted images only, followed by a second blinded interpretation, this time including analysis of pre- and post-gadolinium administration images and a third blinded interpretation based on the time-intensity curve of the dynamic enhanced study. The standard of reference was the histologic assessment of a cylindrical specimen of the proximal pole obtained during surgery in all patients. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for unenhanced, enhanced, and dynamic gadolinium-enhanced MRI studies.

RESULTS

The sensitivity, specificity, PPV, and NPV were 67, 67, 50, and 80 % for unenhanced images, 83, 100, 100, and 92 for enhanced images, and 83, 92, 83, and 92 for dynamic contrast-enhanced images.

CONCLUSIONS

Our data are consistent with previously reported data supporting contrast-enhanced MRI for assessment of viability, and showing that dynamic imaging with time-intensity curve analysis does not provide additional predictive value over standard delayed enhanced imaging for acute scaphoid fracture.

Scaphoid interfragmentary motions due to simulated transverse fracture and volar wedge osteotomy

BACKGROUND

Our goal was to determine 3-dimensional interfragmentary motions due to simulated transverse fracture and volar wedge osteotomy of the scaphoid during physiologic flexion-extension of a cadaveric wrist model.

METHODS

The model consisted of a cadaveric wrist (n = 8) from the metacarpals through the distal radius and ulna with load applied through the major flexor-extensor tendons. Flexibility tests in flexion-extension were performed in the following 3 test conditions: intact and following transverse fracture and wedge osteotomy of the scaphoid. Scaphoid interfragmentary motions were measured using optoelectronic motion tracking markers. Average peak scaphoid interfragmentary motions due to transverse fracture and wedge osteotomy were statistically compared (P<0.05) to intact.

FINDINGS

The accuracy of our computed interfragmentary motions was ± 0.24 mm for translation and ± 0.54° for rotation. Average peak interfragmentary motions due to fracture ranged between 0.9 mm to 1.9 mm for translation and 5.3° to 10.8° for rotation. Significant increases in interfragmentary motions were observed in volar/dorsal translations and flexion/extension due to transverse fracture and in separation and rotations in all 3 motion planes due to wedge osteotomy.

INTERPRETATION

Comparison of our results with data from previous in vitro and in vivo biomechanical studies indicates a wide range of peak interfragmentary rotations due to scaphoid fracture, from 4.6° up to 30°, with peak interfragmentary translations on the order of several millimeters. Significant interfragmentary motions, indicating clinical instability, likely occur due to physiologic flexion-extension of the wrist in those with transverse scaphoid fracture with or without volar bone loss.