The epidemiology of fractures of the scaphoid

In vivo non-contact regions of proximal scaphoid in six extreme wrist positions

INTRODUCTION

Fractures of the scaphoid are the most common carpal injuries, account for 80-90% of all carpal fractures. 5-15% nonunion of scaphoid fractures were reported even with adequate primary treatment, which probably progresses to osteoarthritic changes several decades later. Researches regarding to scaphoid physiological characteristic in vitro and in vivo and kinds of trials in clinical practice are being kept on going, which contribute much to our clinical practice. With the advancing wrist arthroscopy, 3D-print patient-specific drill guide, and intraoperative fluoroscopic guidance, dorsal approach (mini-invasive and percutaneous technique) is being popular, through which we can implant the screw in good coincidence with biomechanics and with less disturbing tenuous blood supply of the scaphoid. Investigating the noncontact area of the dorsal proximal scaphoid in different wrist positions can facilitate preoperatively estimating insert point of the screw.

MATERIALS AND METHODS

Eight volunteers were recruited to accept CT scans in six extreme wrist positions. The images of DICOM mode were imput into the Mimics analytical system, the segmented scaphoid, lunate and radius were exported in mode of ASCII STL and were opened in the software of Geomagic studio. We created four planes based on anatomic markers on the surface of the radius and scaphoid to confine the proximal scaphoid to form the so-called non-contact regions. We measured and compared the areas in six targeted positions.

RESULTS

Amidst six extreme wrist positions, area of the non-contact region in extreme dorsal extension (59.81 ± 26.46 mm2) was significantly the smallest, and it in extreme palmar flexion significantly was largest (170.51 ± 30.44 mm2). The non-contact regions increased in order of dorsal extension, supination, ulnar deviation, radial deviation, pronation and palmar flexion. As for two-group comparison, the non-contact region showed significantly larger (p < 0.05) in palmar flexion than the others except for in pronation individually, and in radial deviation (p < 0.05) than in dorsal extension.

CONCLUSIONS

Sufficient space was available for the screw started from the dorsal approach despite the wrist positions.

Arthroscopic surgery for scaphoid nonunion: a 10-year systematic literature review

The purpose of the study was to investigate whether arthroscopic treatment of carpal scaphoid nonunions by osteosynthesis with bone grafting represents a successful surgical technique. This systematic literature review, conducted following the PRISMA guidelines, explores the past 10 years of clinical studies concerning the arthroscopic treatment of scaphoid nonunions. The most relevant keywords were used to search the databases, and the Downs and Black 27-item checklist has been used as quality assessment tool. Twelve papers that meet the premised eligibility criteria have been identified. These studies demonstrate the efficacy of this surgical solution, achieving a postoperative union rate of 96% in the average time of 13.5 weeks. Regardless of the method of synthesis and the origin of the graft used, excellent results were obtained. Patients who underwent this procedure reported a pain reduction of almost 80% compared to the preoperative level, improvement in grip strength close to 40%, and recovery in wrist function during daily activities. Arthroscopy has numerous advantages compared to the open approach. These are technically recognized by the surgeon and by the patient. Some disadvantages include a longer intraoperative time and considerable significant technical difficulty. Arthroscopic treatment of scaphoid nonunion by osteosynthesis with bone graft achieves a 96% union rate of the treated scaphoid with satisfying clinical results.

Carpal fractures: epidemiology, classification and treatment of 6542 fractures from the Swedish Fracture Registry

This study describes the age and sex distribution, trauma mechanism, treatment and influence of patient-reported outcomes of 6542 carpal fractures from the Swedish Fracture Registry (SFR). The most commonly fractured carpal bone was the scaphoid (60%), followed by the triquetrum (25%), hamate (5%) and trapezium (4%). The mean age at injury was 41 years, and 69% of patients were male. The age and sex distribution of carpal fractures differed substantially between the different carpal bones. Men were more likely to sustain a carpal fracture after high-energy trauma and were more likely to be treated surgically. Carpal fractures had a small negative effect on the Short Musculoskeletal Function Assessment Hand/Arm Index and EQ-5D scores 1 year after the injury.Level of evidence: IV.

Reasons for scaphoid non-union: Analysis of behavior of health care providers and patients

To assess factors related to health-system and patient behavior in scaphoid fracture non-union, a retrospective analysis of 134 patients treated by scaphoid reconstruction was performed. Mean age at the accident was 26 years (range, 9-75 years), and the mean age at surgery was 28 years (range, 13-75 years). Mean time to first consultation was 233 days (range, 0-12,136 days), and time to surgery 740 days (range, 19-12,362 days). The physician was mainly a general practitioner (52.2%), or an orthopedist/traumatologist (17.9%), general surgeon (12.7%), or hand surgeon (17.2%). The initial diagnostic procedure was X-ray in 76.9% of cases, computed tomography (CT) in 20.9%, magnetic resonance imaging (MRI) in 13.4%, and none in 11.2%. A fracture was diagnosed in 32.8% of cases, and non-union in 14.9%. Patients mainly presented late: 63% within 3 weeks, and a minority on the day of the accident (39%). In 11% of cases, healthcare providers performed either no or inadequate imaging (77%) and missed correct diagnosis in 52% of cases. 128 patients had a second consultation, and 77 a third, with the same or different physicians, before surgery, leading to increased healthcare costs due to delayed diagnosis and treatment. Delayed presentation and lack of suspicion by attending physicians were the main reasons. Speeding up diagnosis and improving physician training are vital and could significantly reduce health care costs. CT or MRI should be performed if scaphoid fracture is suspected.

Nonunion scaphoid bone shape prediction using iterative kernel principal polynomial shape analysis

BACKGROUND

The scaphoid is an important mechanical stabilizer for both the proximal and distal carpal columns. The precise estimation of the complete scaphoid bone based on partial bone geometric information is a crucial factor in the effective management of scaphoid nonunion. Statistical shape model (SSM) could be utilized to predict the complete scaphoid shape based on the defective scaphoid. However, traditional principal component analysis (PCA) based SSM is limited by its linearity and the inability to adjust the number of modes used for prediction.

PURPOSE

This study proposes an iterative kernel principal polynomial shape analysis (iKPPSA)-based SSM to predict the pre-morbid shape of the scaphoid, aiming at enhancing the accuracy as well as the robustness of the model.

METHODS

Sixty-five sets of scaphoid images were used to train SSM and nine sets of scaphoid images were used for validation. For each validation image set, three defect types (tubercle, proximal pole, and avascular necrosis) were virtually created. The predicted shapes of the scaphoid by PCA, PPSA, KPCA, and iKPPSA-based SSM were evaluated against the original shape in terms of mean error, Hausdorff distance error, and Dice coefficient.

RESULTS

The proposed iKPPSA-based scaphoid SSM demonstrates significant robustness, with a generality of 0.264 mm and a specificity of 0.260 mm. It accounts for 99% of variability with the first seven principal modes of variation. Compared to the traditional PCA-based model, the iKPPSA-based scaphoid model prediction demonstrated superior performance for the proximal pole type fracture, with significant reductions of 25.2%, 24.7%, and 24.6% in mean error, Hausdorff distance, and root mean square error (RMSE), respectively, and a 0.35% improvement in Dice coefficient.

CONCLUSION

This study showed that the iKPPSA-based SSM exploits the nonlinearity of data features and delivers high reconstruction accuracy. It can be effectively integrated into preoperative planning for scaphoid fracture management or morphology-based biomechanical modeling of the scaphoid.

A comparative cadaveric study for percutaneous scaphoid fixation: robotic vs freehand

PURPOSES

To compare the robotic-assisted and the traditional freehand percutaneous scaphoid fixation in number of guidewire attempts, duration of fluoroscopy time, amount of radiation dose, and screw centrality.

METHODS

Twenty cadaveric specimens were randomized into either the robotic or freehand group. The scaphoids in both groups were fixed by either the same attending or resident from our hand surgery department. The operation duration, amount of radiation from intraoperative fluoroscopy, total fluoroscopy time, and the number of guidewire attempts were documented and compared. Postoperatively, all the specimens had a computed tomography (CT) scan performed, and the difference in the final position of the screw and the central axis of the scaphoid was examined.

RESULTS

In the robotic group, all the guide wires were satisfactorily positioned within a single attempt, while the median number of attempts in the traditional freehand group was 18 (quaternion 14-65). This also meant that the surgeon in the robotic group experienced significantly lower radiation exposure dose and time as compared to the freehand group. There were no significant differences in the final screw position as compared to the central axis of the scaphoid in both groups. Although there was no difference in surgeon performance in the robotic group, the operative time for the attending was significantly lower as compared to the resident in the freehand group.

CONCLUSION

Robotic-assisted surgery for scaphoid fracture fixation is superior to the traditional freehand method as it facilitates accurate screw placement with lower radiation exposure and fewer guide wire attempts.

The "Standing Peanut" Scaphoid View: A Semi-supinated Radiographic View for Intraoperative Evaluation of Screw Placement in Scaphoid Waist Fractures

Scaphoid waist fractures are the most common fracture of the scaphoid. Operative management is indicated with unstable fractures and often for nondisplaced waist fractures to decrease time to union and return to work/sport. Screw placement within the central axis of the scaphoid is paramount and correlates with outcomes. Assessment of intrascaphoid screw placement is classically done via intraoperative fluoroscopy. An additional fluoroscopic view is presented to assist in confirming implant positioning. Along with the standard anterioposterior, lateral, pronated oblique, and "scaphoid" view we obtain a "standing peanut" view for assessment of central screw placement. This view also allows for further evaluation of center/center positioning and better assessment of fixation crossing the fracture into the proximal pole. The "standing peanut" view is best obtained in a sequential manner beginning with the forearm in neutral rotation. First, the forearm is then supinated 30 degrees; next, the wrist is placed at 45 degrees of ulnar deviation. Then finally, 10 degrees of wrist extension. We utilize this additional intraoperative view in conjunction with the standard fluoroscopic views for assessing and ensuring center-center implant positioning, particularly within the proximal pole. When ensuring center-center positioning, we prefer this view as an adjunct view to the standard fluoroscopic views intraoperatively. It provides a beneficial view of the proximal pole delineating the number of screw threads that have obtained proximal pole purchase. We have found it particularly useful in the setting of scaphoid waist fracture nonunion with the classic 'humpback' deformity after correction with volar interposition grafting. Standard radiographic views may be misinterpreted regarding implant positioning if there remains any residual flexion. The view requires little in the way of training to obtain once appreciated and exposes the patient to minimal additional radiation.

Rethinking Scaphoid Fixation

Scaphoid fixation, whether for acute injuries or nonunion, is made challenging by the small and intra-articular nature of the most commonly fractured carpal bone. The purpose of this article is to review the techniques to simplify scaphoid fixation and to optimize healing and early return to activity.

[Scaphoid fractures : Current diagnostic and treatment concepts]

Scaphoid fractures are by far the most frequent fractures of the carpal bones of the hand and often lead to problematic healing processes if the diagnostics and treatment are inadequate. The main complication of a scaphoid fracture is pseudarthrosis, which leads to carpal collapse and degenerative arthritis of the wrist if left untreated. Early diagnosis and individualized differentiated treatment aim to achieve bony healing with restoration of the scaphoid shape and preservation of the function of the wrist. The anatomical and biomechanical characteristics of the scaphoid can impede bony healing after a fracture and, in contrast to the diagnostics and treatment, cannot be influenced. A history of trauma and typical clinical signs of a scaphoid fracture should lead to systematic imaging diagnostics with obligatory computed tomography. Only by determining the exact fracture morphology can an appropriate treatment concept be established. Conservative treatment should be restricted to stable fractures without relevant displacement. Fractures of the proximal scaphoid pole are considered unstable even if they are not displaced. Operative treatment is indicated for all unstable fractures. The favored surgical procedure is osteosynthesis with a cannulated double-threaded screw, which can be used in a retrograde or antegrade manner and in a minimally invasive or open technique, depending on the fracture type. Surgical treatment results in earlier bony healing and quicker restoration of function but can be associated with a higher complication rate. Posttraumatic osteoarthritis after healing in malalignment is usually asymptomatic.

Assessing the risk of re-fracture related to the percentage of partial union in scaphoid waist fractures

Aims

There is ambiguity surrounding the degree of scaphoid union required to safely allow mobilization following scaphoid waist fracture. Premature mobilization could lead to refracture, but late mobilization may cause stiffness and delay return to normal function. This study aims to explore the risk of refracture at different stages of scaphoid waist fracture union in three common fracture patterns, using a novel finite element method.

Methods

The most common anatomical variant of the scaphoid was modelled from a CT scan of a healthy hand and wrist using 3D Slicer freeware. This model was uploaded into COMSOL Multiphysics software to enable the application of physiological enhancements. Three common waist fracture patterns were produced following the Russe classification. Each fracture had differing stages of healing, ranging from 10% to 90% partial union, with increments of 10% union assessed. A physiological force of 100 N acting on the distal pole was applied, with the risk of refracture assessed using the Von Mises stress.

Results

Overall, 90% to 30% fracture unions demonstrated a small, gradual increase in the Von Mises stress of all fracture patterns (16.0 MPa to 240.5 MPa). All fracture patterns showed a greater increase in Von Mises stress from 30% to 10% partial union (680.8 MPa to 6,288.6 MPa).

Conclusion

Previous studies have suggested 25%, 50%, and 75% partial union as sufficient for resuming hand and wrist mobilization. This study shows that 30% union is sufficient to return to normal hand and wrist function in all three fracture patterns. Both 50% and 75% union are unnecessary and increase the risk of post-fracture stiffness. This study has also demonstrated the feasibility of finite element analysis (FEA) in scaphoid waist fracture research. FEA is a sustainable method which does not require the use of finite scaphoid cadavers, hence increasing accessibility into future scaphoid waist fracture-related research.

Fixation Techniques for Scaphoid Nonunion

Scaphoid fractures are common injuries with high risk of nonunion. Various fixation techniques exist for managing scaphoid nonunions, including Kirschner wires, single or dual headless compression screws, combination fixation techniques, volar plating, and compressive staple fixation. The indication for each fixation technique varies depending on the patient, type of nonunion, and clinical scenario.

Early MRI for Pediatric Wrist Injuries-Prospective Case Series of 150 Cases

Background  Pediatric carpal injuries are a clinical challenge due to their non-specific clinical features and occult nature on plain radiography. We hypothesized that early magnetic resonance imaging (MRI) will allow prompt diagnosis and treatment stratification, and that distal pole fracture of the scaphoid requires a shorter duration of immobilization. This study aims to assess the injury pattern and clinical outcomes of under-16-year-olds treated with acute post-traumatic wrist injuries in accordance with the unit's protocol. Methods  All patients under the age of 16 years treated for suspected pediatric wrist injuries in our tertiary pediatric hand and upper limb service were included. Prospectively collected data included patient demographics, radiological findings, treatment and adherence to the unit's protocol. Results  There were 151 patients with a mean age of 12 years. The majority (72%) had occult bony injury with radiological evidence of fracture on MRI. The sensitivity and specificity of plain film radiography were 42.7% and 71.4%, respectively. Almost one in four patients benefitted from early MRI demonstrating no injuries, permitting early mobilization and discharge. The scaphoid was the most commonly injured carpal bone. Non-displaced fractures of the distal pole of the scaphoid in patients over 10 years old were treated with 4 weeks' immobilization with no adverse outcome. Conclusion  Standardized care in our unit has yielded good results with low complication rate and fewer hospital appointments. Our results support the routine early use of MRI and a shorter duration of immobilization in fracture of the distal pole of the scaphoid at 4 weeks. Level of Evidence  This is a level IV, case series study.

Scaphoid Bone Nonunions: Clinical and Functional Outcomes of Collagen/PGA Scaffolds and Cell-Based Therapy

In this study, the procedure for treating the nonunion complication of scaphoid fractures using collagen/poly glycolic acid (CPGA) scaffolds with bone marrow mesenchymal stem cell (BM-MSC) therapy was adopted and compared with the commonly employed autologous bone tissue graft. With conducting a two-armed clinical trial, 10 patients with scaphoid nonunions were enrolled in this investigation. Patients were randomly assigned to two groups treated with (1) CPGA + cell therapy and (2) autologous iliac crest bone graft standard therapy. Treatment outcomes were evaluated three months after surgery, measuring the grip and pinch strengths and wrist range of motion, with two questionnaires: Patient-Rated Wrist Evaluation (PRWE) and Quick form of Disabilities of the Arm, Shoulder, and Hand (QDASH). We have also assessed the union rate using clinical and radiologic healing criteria one and three months post-operatively. Restorative effects of CPGA + cell therapy were similar to those of the autologous bone graft standard therapy, except for the grip strength (P = 0.048) and QDASH score (P = 0.044) changes, which were higher in the CPGA + cell therapy group. Three months following the surgery, radiographic images and computed tomography (CT) scans also demonstrated that the scaphoid union rate in the test group was comparable to that of scaphoids treated with the standard autograft method. Our findings demonstrate that the CPGA + cell therapy is a potential alternative for bone grafting in the treatment of bone nonunions.

Comparison of Conservative Treatment and Surgery Treatment for Acute Scaphoid Fracture: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

This meta-analysis aimed to investigate the effectiveness of conservative and surgical treatments of scaphoid fracture.

METHODS

The literature databases of Pubmed, Cochrane library, and Embase were searched in March 2022. This work extracted the data based on healing time, grip strength, range of wrist motion, nonunion, time before returning to work, and complications (including persistent pain, malunion of the fracture, wound infection, scar sensitivity, hypertrophic scar, and implant-related complications). Stata 14.0 software was used for statistical analysis.

RESULTS

Twelve RCTs studies met our inclusion criteria. The surgical group had a shorter healing-time and time before returning to work than the conservative group. In addition, the surgical group had significantly better grip strength and range of wrist motion than the conservative group (P < 0.01). However, there was no significant difference between nonunion (P = 0.538) and complications (P = 0.661) between the two groups.

CONCLUSION

This meta-analysis showed that surgical treatment of scaphoid fracture achieved better grip strength and range of wrist motion, and had a lower healing time and time before returning to work than the conservative treatment. The two treatments had similar results in nonunion and complications. Further RCTs were required for the research.

How Is Scaphoid Malunion Defined: A Systematic Review

BACKGROUND

Abnormal scaphoid alignment after fracture is used as an indication for fixation. Acceptable alignment after reduction and fixation of scaphoid fractures is not well defined. We systematically reviewed the literature to identify how scaphoid malunion is currently defined and by what parameters.

METHODS

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Multiple databases were searched for studies published in the English language that reported on outcomes after scaphoid malunion and included measurements to define malunions. Radiographic scaphoid measurement parameters were collected. Clinical outcome measures recorded included grip strength, wrist range of motion, and patient-reported outcome measures. Study quality was analyzed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. Descriptive summaries of the studies are presented.

RESULTS

The initial search yielded 1600 articles. Ten articles (161 participants, 93% males, mean age = 28.3 + 6.3 years, mean MINORS score = 10.2 + 1.6) were included and analyzed. Scaphoid malunion was defined if the lateral intrascaphoid angle (LISA) was >45° (3 articles), LISA >35° (1 article), and height to length ratio >0.6 (3 articles). Four out of 5 studies found no significant associations between patient outcomes and degree of scaphoid malunion measured on imaging.

CONCLUSIONS

There is a lack of consensus for defining scaphoid malunion on imaging and absence of correlation between findings on imaging and patient outcomes. Future studies defining scaphoid malunion should be appropriately powered, incorporate measures of intrarater and interrater reliabilities for all reported imaging measurements, and utilize validated patient-reported outcome measures to reflect that malunion is associated with inferior outcomes meaningful to patients.

Hand Surgeons Are Tackling Tougher Scaphoids: A Study of ABOS Candidate Data

BACKGROUND

This study will evaluate whether those who have completed a hand fellowship treat a disproportionate number of scaphoid fractures based on recent American Board of Orthopaedic Surgery (ABOS) data. We hypothesize that surgeons who have completed a fellowship in hand surgery will address most surgically treated scaphoid fractures, particularly those with fracture nonunions or requiring graft.

METHODS

We queried the ABOS database for case log information submitted for part II of the ABOS examination. This search included all cases with Current Procedural Terminology codes for procedures related to scaphoid fixation. Demographic information, case volume, type of case, and complication rate were compared for hand fellowship-trained surgeons and those who had completed other fellowships as well as non-fellowship-trained surgeons.

RESULTS

During the study period, 1686 surgeons reported treating 4244 scaphoid fractures. Of these surgeons, 1180 had completed a hand surgery fellowship. Hand fellowship-trained surgeons were shown to have operatively treated more scaphoid fractures both in total volume and on a per-surgeon basis. Hand fellowship-trained surgeons were also found to have performed a significantly higher proportion of difficult cases, which were those listed as being a malunion/nonunion or those incorporating a pedicle graft. There was no difference in the complication rate between the 2 groups.

CONCLUSION

Among those orthopedic surgeons reporting case information for part II of the ABOS certification examination, statistically significant differences exist in case volume and case difficulty among surgeons with different areas of fellowship training. Complication rates increase with patient age and examination year.

The influence of partial union on the mechanical strength of scaphoid fractures: a finite element study

Assessment of scaphoid fracture union on computed tomography scans is not currently standardized. We investigated the extent of scaphoid waist fracture union required to withstand physiological loads in a finite element model, based on a high-resolution CT scan of a cadaveric forearm. For simulations, the scaphoid waist was partially fused at the radial and ulnar sides. A physiological load of 100 N was transmitted to the scaphoid and the minimal amount of union to maintain biomechanical stability was recorded. The orientation of the fracture plane was varied to analyse the effect on biomechanical stability. The results indicate that the scaphoid is more prone to re-fracture when healing occurs on the ulnar side, where at least 60% union is required. Union occurring from the radial side can withstand loads with as little as 25% union. In fractures more parallel to the radial axis, the scaphoid seems less resistant on the radial side, as at least 50% union is required. A quantitative CT scan analysis with the proposed cut-off values and a consistently applied clinical examination will guide the clinician as to whether mid-waist scaphoid fractures can be considered as truly united.

Arthroscopic treatment of unstable scaphoid fracture and nonunion with two headless compression screws and distal radius bone graft

BACKGROUND

The treatment of unstable scaphoid fracture and nonunion remains a challenging problem for hand surgeons. Minimally invasive treatment has become the preferred method of treatment.

PURPOSE

This study introduces the arthroscopic technique with two headless compression screws (HCS) fixation and distal radius bone grafting for the treatment of unstable scaphoid fracture and nonunion, aiming to evaluate its clinical and radiological outcomes.

METHODS

It was a retrospective study. From January 2019 to February 2021, a total of 23 patients were included in the current study. Among them, 13 patients with unstable scaphoid fracture underwent arthroscopic treatment with two HCS; 10 patients with scaphoid nonunion underwent arthroscopic treatment with two HCS and a distal radius bone graft. The range of motion of the wrist, visual analog scale (VAS), grip strength, the Modified Mayo Wrist Score (MMWS), the Patient-Rated Wrist Evaluation (PRWE) score, and the Disability of the Arm, Shoulder and Hand (DASH) score were collected at preoperatively and the final follow-up. A computed tomography scan of the wrist was performed on each patient to analyze for union and postoperative osteoarthritis during the follow-up period.

RESULTS

Significant improvement was only observed in wrist extension. Clinical outcomes including grip strength, VAS pain score, MMWS, PRWE score, and DASH score were significantly improved at the final follow-up. In the subgroup analysis, both patients stabilized with either two HCS or a distal radius bone graft and two HCS have improved clinical outcomes after surgery, respectively. All patients achieved union. No screw fixation failure occurred, and no other postoperative complication was observed in any of the patients.

CONCLUSIONS

The arthroscopic technique with two-HCS fixation and distal radius bone grafting is a reliable and effective technique for the treatment of unstable scaphoid fracture and nonunion, providing satisfactory union rates and clinical outcomes.

Residual flexion deformity after scaphoid nonunion surgery: 7-year follow-up study

The clinical implication of a residual flexion deformity following surgery for scaphoid nonunion is unclear. Sixty-three patients who underwent scaphoid nonunion surgery were assessed after a mean of 7 years (range 5-10) to analyse the outcomes based on the presence of residual scaphoid deformity. Primary outcome was Disabilities of the Arm, Shoulder and Hand score. Secondary outcomes were Patient-Rated Wrist Evaluation score, wrist range of motion and strength. Patients were dichotomized to residual deformity or no deformity. Scaphoid deformity was calculated from CT scans based on the median difference between the height-length ratio of the operated versus the uninjured scaphoid. There were no differences between residual deformity (n = 33) and no deformity (n = 30) in any outcome variables, except for wrist extension which was slightly worse in the deformity group. The deformity group had a greater number of radiographic osteoarthritis, but all cases were mild, and osteoarthritis did not correlate to a worse outcome. We conclude that residual scaphoid deformity has no relevant negative impact on mid-term wrist function.Level of evidence: IV.

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.

The incidence of musculoskeletal injuries: a systematic review and meta-analysis

Aims

The aim of this systematic review and meta-analysis was to gather epidemiological information on selected musculoskeletal injuries and to provide pooled injury-specific incidence rates.

Methods

PubMed (National Library of Medicine) and Scopus (Elsevier) databases were searched. Articles were eligible for inclusion if they reported incidence rate (or count with population at risk), contained data on adult population, and were written in English language. The number of cases and population at risk were collected, and the pooled incidence rates (per 100,000 person-years) with 95% confidence intervals (CIs) were calculated by using either a fixed or random effects model.

Results

The screening of titles yielded 206 articles eligible for inclusion in the study. Of these, 173 (84%) articles provided sufficient information to be included in the pooled incidence rates. Incidences of fractures were investigated in 154 studies, and the most common fractures in the whole adult population based on the pooled incidence rates were distal radius fractures (212.0, 95% CI 178.1 to 252.4 per 100,000 person-years), finger fractures (117.1, 95% CI 105.3 to 130.2 per 100,000 person-years), and hip fractures (112.9, 95% CI 82.2 to 154.9 per 100,000 person-years). The most common sprains and dislocations were ankle sprains (429.4, 95% CI 243.0 to 759.0 per 100,000 person-years) and first-time patellar dislocations (32.8, 95% CI 21.6 to 49.7 per 100,000 person-years). The most common injuries were anterior cruciate ligament (17.5, 95% CI 6.0 to 50.2 per 100,000 person-years) and Achilles (13.7, 95% CI 9.6 to 19.5 per 100,000 person-years) ruptures.

Conclusion

The presented pooled incidence estimates serve as important references in assessing the global economic and social burden of musculoskeletal injuries. Cite this article: Bone Joint Res 2022;11(11):814–825.

Wrist angle measurements in predicting the presence of a displaced scaphoid fracture

PURPOSE

Early diagnosis and treatment of scaphoid fractures is critical to achieve union and prevent wrist degenerative arthritis. Plain radiographic measurements can guide the early approach to suspected fractures. Specifically, the ability to predict fracture or fracture stability from plain radiographs may allow the traumatologist to expand initial referral to three-dimensional imaging. We evaluated the ability of four measured angles to predict presence of a scaphoid fracture and stability.

METHODS

Fifty patients with a scaphoid fracture and 50 patients without fracture were evaluated for the cortical ring sign, scapho-lunate gapping, lateral scapholunate (SL), radio-scaphoid (RS), radio-lunate (RL), and radio-capitate (RC) angles by two-blinded observers.

RESULTS

Measurement of an increased SL interval was associated with the presence of a scaphoid fracture as diagnosed on three-dimensional imaging [odds ratio (OR) 3.0, confidence interval (CI) 1.53-5.87, p =  < 0.01]. The measured RL angle was associated with fracture displacement (OR 1.13, 95% CI 1.02-1.25, p = 0.02).

CONCLUSIONS

Scapholunate gapping on plain radiographs in the context of a clinically suspected scaphoid fracture should increase suspicion for a fracture and may prompt earlier 3-dimensional imaging, while the presence of an abnormal radiolunate angle should increase wariness for instability and can be used in preoperative planning.

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.

Virtual management of clinically suspected scaphoid fractures

AIMS

The aim of this study was to describe the introduction of a virtual pathway for the management of patients with a suspected fracture of the scaphoid, and to report patient-reported outcome measures (PROMs) and satisfaction following treatment using this service.

METHODS

All adult patients who presented with a clinically suspected scaphoid fracture that was not visible on radiographs at the time of presentation during a one-year period were eligible for inclusion in the pathway. Demographic details, findings on examination, and routine four-view radiographs at the time of presentation were collected. All radiographs were reviewed virtually by a single consultant hand surgeon, with patient-initiated follow-up on request. PROMs were assessed at a minimum of one year after presentation and included the abbreviated version of the Disabilities of the Arm, Shoulder and Hand Score (QuickDASH), the EuroQol five-dimension five-level health questionnaire (EQ-5D-5L), the Net Promoter Score (NPS), and return to work.

RESULTS

A total of 221 patients were referred to the virtual pathway. Their mean age was 41 years (range 16 to 87) and there were 99 male patients (45%). A total of 189 patients (86%) were discharged with advice and 19 (9%) were recalled for clinical review: seven with an undisplaced scaphoid fracture, six with another fracture of the hand or wrist, two with a scapholunate ligament injury, and four in whom no abnormality was detected. A total of 13 patients (6%) initiated follow-up with the hand service: no fracture or ligament injury was identified in this group. PROMs were available for 179 patients (81%) at a mean follow-up of 19 months (range 13 to 33). The median QuickDASH score was 2.3 (interquartile range (IQR) 0 to 15.9), the median EQ-5D-5L was 0.85 (IQR 0.73 to 1.00), the NPS was 76, and 173 patients (97%) were satisfied with their treatment. There were no documented cases of symptomatic nonunion one year following injury.

CONCLUSION

We describe the introduction of a virtual pathway for the management of patients with a suspected scaphoid fracture. We found high levels of patient satisfaction, excellent PROMs, and no detrimental effects in the vast majority of cases. Cite this article: Bone Joint J 2022;104-B(6):709-714.

Locking plate osteosynthesis of scaphoid nonunion with severe bone defects: a case series

The treatment of scaphoid nonunion can be challenging with increasing defect size. We evaluated the outcome of scaphoid nonunion with a substantial bone defect treated with a multidirectional locking plate combined with cancellous bone grafting only. Thirteen patients with significant osseous defects measuring 6 mm or more suffering from primary nonunion without treatment (n = 6) or recalcitrant nonunion following Herbert screw osteosynthesis (n = 7) were treated and reviewed retrospectively. The stabilization was performed after debridement, autologous cancellous bone grafting and volar locking plate osteosynthesis. After a mean follow-up period of 12 months, 12 of the 13 patients achieved successful unions with a free range of motion and complete remittance of pain in everyday activity. The mean scapholunate angle decreased from 59.7° ± 11 to 43.9° ± 5 (effect strength d:1.7, p < 0.00001), scaphoid humpback deformity angle from 58.9° ± 8 to 45.1° ± 8 (d:1.8, p < 0.0001), whereas strength of the injured hand increased from 36.4 kg ± 10 to 42.4 kg ± 9 (d:1.4, p < 0.0001). One nonunion persisted without fragment dislocation receiving revision after 1 year. Thus, locking plate osteosynthesis with cancellous bone grafting is a valid alternative in scaphoid nonunions with extensive bone defects. Additionally, stable retention of the fragments prevents dislocation even in delayed or persistent nonunion. Further prospective studies are required to confirm these findings.

Non-Displaced Scaphoid Waist Fractures: Percutaneous Screw Fixation Versus Cast Immobilization

Background

Scaphoid waist fractures make up 66% of scaphoid fractures and are mostly non-displaced. The purpose of this study was to demonstrate that percutaneous screw fixation is preferable to cast immobilization in the treatment of non-displaced or minimally displaced scaphoid waist fractures.

Methodology

Between 2017 and 2019, we conducted a retrospective review of patients aged 17-65 years who underwent treatment for acute non-displaced scaphoid waist fractures. In total, 52 patients with scaphoid waist fractures were included in the analysis, 25 of whom underwent percutaneous screw treatment and 27 were treated with a short plaster cast. Patient satisfaction, pain, range of motion, and grip strength were evaluated using the Mayo Modified Wrist Score (MMWS). In addition, the time to return to work/sports, union time, complications, and non-union status were evaluated.

Results

A total of 52 (35 male, 15 female) patients were enrolled in this study. The average follow-up time was 24.9 months (range, 24-29 months). The mean age was 28.12 years (range, 17-45 months). Group 1 consisted of 25 patients who underwent percutaneous screw fixation, and group 2 consisted of 27 patients who were treated with a short plaster cast. There were significant differences in return to work, return to sports, and union time between the two groups (p < 0.001). The sixth-month MMWS was significantly different between the two groups (p < 0.001), but the first-year MMWS was not significantly different between the two groups (p = 0.864). There were no complications in both groups.

Conclusions

With percutaneous screw fixation, acute non-displaced or minimally displaced scaphoid waist fractures demonstrated a high rate of union and early return to work/sports.

Cannulated compression screw with versus without two K-wire fixation for treatment of scaphoid waist fracture nonunion

Purpose

This study aims to introduce the “tripod” technique using cannulated compression screw and two anti-rotational K-wires for treatment of unstable scaphoid waist fracture nonunion, and to compare it with the single cannulated screw fixation technique in term of scaphoid union and surgical outcomes.

Methods

It was a retrospective study. From January 2014 to March 2020, 103 consecutive patients with scaphoid waist fracture nonunion treated with the tripod fixation and bone grafting (n = 45) or with single cannulated compression screw and bone grafting (n = 58) were included. All the procedures were performed by the same hand surgery team, and autologous cortico-cancellous radius bone graft was used for bony reconstruction. The minimal follow-up period was 12 months. The union rate and the time to union, range of motion (ROM), grip strength, Visual Analogue Scale (VAS), Quick Disabilities of the Arm, Shoulder and Hand (DASH) score and modified Mayo Scores at the last visit were compared.

Results

In tripod fixation group, bony union was achieved in all patients at the mean of 14.8 ± 3.8 weeks, while in the single cannulated screw fixation group the bony union rate was 94.8% (55/58) and the time to union was 17.6 ± 3.6 weeks. The difference of time to union was statistically significant (p = 0.027), but not for bony union rate (p = 0.122). At the last visit, no significant difference was found with respect to any clinical and radiographic outcome measures (all p > 0.05). The overall rate of complications was not significantly different between two groups (15.6% vs 10.3%, p = 0.430).

Conclusions

Tripod fixation technique with headless compression screw and two K-wires is a safe and effective technique for treatment of scaphoid nonunion fixation and can be considered to use in practice, especially for those potentially rotationally unstable cases.

Diagnosis of Suspected Scaphoid Fractures

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Suspected scaphoid fractures are a diagnostic and therapeutic challenge despite the advances in knowledge regarding these injuries and imaging techniques. The risks and restrictions of routine immobilization as well as the restriction of activities in a young and active population must be weighed against the risks of nonunion that are associated with a missed fracture.

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The prevalence of true fractures among suspected fractures is low. This greatly reduces the statistical probability that a positive diagnostic test will correspond with a true fracture, reducing the positive predictive value of an investigation.

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There is no consensus reference standard for a true fracture; therefore, alternative statistical methods for calculating sensitivity, specificity, and positive and negative predictive values are required.

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Clinical prediction rules that incorporate a set of demographic and clinical factors may allow stratification of secondary imaging, which, in turn, could increase the pretest probability of a scaphoid fracture and improve the diagnostic performance of the sophisticated radiographic investigations that are available.

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Machine-learning-derived probability calculators may augment risk stratification and can improve through retraining, although these theoretical benefits need further prospective evaluation.

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Convolutional neural networks (CNNs) are a form of artificial intelligence that have demonstrated great promise in the recognition of scaphoid fractures on radiographs. However, in the more challenging diagnostic scenario of a suspected or so-called "clinical" scaphoid fracture, CNNs have not yet proven superior to a diagnosis that has been made by an experienced surgeon.

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.

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.

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.

How to manage scaphoid waist fractures? Introduction of pragmatic imaging efficient pathway and literature review of the recent evidence

INTRODUCTION AND OBJECTIVE

The scaphoid bone sustains about 90 % of carpal bone fractures and is the second-highest bone at risk of post-traumatic osteonecrosis. Delayed diagnosis and treatment could lead to non-union and advanced carpal bones collapse. This study aimed to introduce an imaging efficient and practical scaphoid waist fracture management pathway (SWFMP) and measure its efficacy in clinical practice.

MATERIALS AND METHODS

The SWFMP was introduced in January 2020. Suspected occult fractures were approached by early orthopaedic clinical assessment and subsequent urgent MRI scan without repeating scaphoid X-rays. Scaphoid waist fractures displaced < 2 mm were treated with 8 weeks below elbow cast immobilization followed by CT scan if delayed union was suspected. Waist fractures displaced > 2 mm were managed with surgical fixation. Adult patients referred from the emergency department (ED) to the Virtual Fracture Clinic (VFC) with acute scaphoid injury from January 2019 to October 2019 (Pre SWFMP, n = 29), were identified and compared to those managed from January 2020 to October 2020 (Post SWFMP, n = 33).

RESULTS

Mean age was 37.9 (SD = 20.61) and 36.2 (SD = 17.06) years in the pre-SWFMP and post-SWFMP cohorts respectively. Fiften patients (51.7%) had the right side affected in the pre-SWFMP cohort and twenty-three patients (69.7%) in the post-SWFMP cohort. Scaphoid X-rays requested by ED have increased from 19 (65.5%) to 31 (94%) and repeated X-rays reduced from 17 (58.6%) to 10 (30.3%) after the introduction of the SWFMP. Mean wrist cast immobilization for patients without scaphoid fractures dropped from 16.9 days (SD = 5.57) to 3.6 days (SD = 6.24) after the SWFMP (p = 0.001). In the pre-SWFMP cohort, 24 patients had no fracture, 4 achieved full healing and 1 developed non-union. In the post-SWFMP cohort, 29 patients had no fracture, 1 achieved full union and delayed union was detected in 3 patients at 8 weeks.

CONCLUSIONS

The SWFMP has improved the clinical practice by reducing unnecessary ionizing radiation, unnecessary cast immobilization, and by using a timely fracture fixation intervention.

Radiographic characterization of acute scaphoid fractures in children under 11 years of age

BACKGROUND

Delayed diagnosis of scaphoid fractures can lead to long-term morbidity. While radiography is the preferred screening examination, there is a relative paucity of literature that examines fracture visibility in younger children, who have smaller ossification centers, an abundance of unossified cartilage and fractures that preferentially involve the distal scaphoid.

OBJECTIVE

To characterize acute scaphoid fractures in younger children on radiographs with observer agreement and with respect to fracture location.

MATERIALS AND METHODS

This institutional review board (IRB)-approved and Health Insurance Portability and Accountability Act (HIPAA)-compliant cross-sectional study included children (≤10 years of age) with acute scaphoid fractures (≤7 days), who underwent radiographic examinations at a tertiary children's hospital between December 2008 and June 2019. Three readers (two pediatric radiologists and one orthopedic surgeon) reviewed each examination to determine fracture visibility on each radiographic view and fracture location. Kruskal-Wallis, Fisher exact and Cochran-Armitage tests were used to compare fracture visibility and location, and Kappa tests were used to calculate observer agreement.

RESULTS

Twenty-eight children (15 boys, 13 girls; mean age: 9.5±0.6 years) with 10 (36%) distal corner, 11 (39%) distal body and 7 (25%) mid-body fractures, underwent 7 (25%) 4-view, 18 (64%) 3-view and 3 (11%) 2-view examinations. Twenty-six (93%) fractures were visible on at least one view with six (21%) fractures visible on all available views. No significant association was found between fracture visibility and fracture location (P=0.32). Observer agreement was substantial to almost perfect.

CONCLUSION

Only 7% of these acute scaphoid fractures in younger children are inconspicuous on the initial radiographic examination.

Cost-effectiveness of surgery versus cast immobilization for adults with a bicortical fracture of the scaphoid waist : an economic evaluation of the SWIFFT trial

AIMS

The aim of the Scaphoid Waist Internal Fixation for Fractures Trial (SWIFFT) was to determine the optimal treatment for adults with a bicortical undisplaced or minimally displaced fracture of the waist of the scaphoid, comparing early surgical fixation with initial cast immobilization, with immediate fixation being offered to patients with nonunion.

METHODS

A cost-effectiveness analysis was conducted to assess the relative merits of these forms of treatment. The differences in costs to the healthcare system and quality-adjusted life years (QALYs) of the patients over the one-year follow-up of the trial in the two treatment arms were estimated using regression analysis.

RESULTS

Our base case analysis found that patients randomized to early surgical fixation had statistically significantly higher mean costs to the NHS of £1,295 more than for the cast immobilization arm (p < 0.001), primarily due to the cost of surgery. They also had a marginally better quality of life, over the period, of 0.0158 QALYs; however, this was not statistically significant (p = 0.379). The mean combined cost per additional QALY was £81,962, well above the accepted threshold for cost-effectiveness used in the UK and internationally. The probability of early surgery being cost-effective in this setting was only 5.6%.

CONCLUSION

Consistent with the clinical findings of SWIFFT, these results indicate that initial cast immobilization of minimally displaced scaphoid fractures, with immediate fixation only offered to patients with nonunion, is the optimal form of treatment, resulting in comparable outcomes with less cost to the healthcare system. Cite this article: Bone Joint J 2021;103-B(7):1277-1283.

Cone-beam computed tomography for primary investigation of wrist trauma provides a new map of fractures of carpal bones

In 2016, our primary modality for radiological examination of wrist trauma, was changed from radiography to cone-beam computed tomography (CBCT). This is a retrospective survey of carpal bone fractures detected by CBCT during 6 months in 2016/2017, compared with those found on conventional radiographs during 6 months in 2013/2014. The incidence of carpal fractures was three times higher during the CBCT period (92/100,000 per year) compared with the radiography period (29/100,000 per year) and the spectrum of anatomical locations was different between the two periods, with fractures of the lunate (n = 6), trapezium (n = 9), trapezoid (n = 4) and capitate (n = 1) detected by CBCT, in contrast to no fractures of these bones diagnosed during the 6 months radiography period. We suggest a more liberal use of CBCT for examination of wrist trauma considering the benefits of being able to give patients a correct primary diagnosis, treatment and prognosis.Level of evidence: III.

Scaphoid plating for recalcitrant scaphoid fractures: a systematic review

We conducted a systematic review of scaphoid plating for recalcitrant scaphoid fractures using EMBASE, Pubmed, Cochrane and MEDLINE. Thirteen studies were included. Ninety-three per cent of cases reported were male with a mean age of 27 years. Bony union was reported in eleven studies and achieved in 72% to 100% of cases. Scaphoid plates showed no significant difference in union incidence compared with headless compression screws. Mean removal incidence of plates was 21%. Postoperative flexion-extension arc was 119°. Grip strength improved by 14% postoperatively over that before surgery. There was a general improvement in patient-reported outcome measures. Eighty-six per cent of reported participants returned to their previous work. In these clinical reports, plates frequently required removal more frequently than headless compression screws.

Reliability of clinical tests for prediction of occult scaphoid fractures and cost benefit analysis of a dedicated scaphoid pathway

We reviewed the outcomes of our dedicated clinic for suspected scaphoid fractures. The primary outcome measure was to test the reliability of accurately diagnosing an occult scaphoid fracture with a combination of anatomical snuff box, scaphoid tubercle, longitudinal compression tenderness, ulnar deviation and the pinch test. Cost savings of the new patient pathway was our secondary outcome measure. Between December 2016 and March 2020, 922 patients were recruited at a mean of 12 days post-injury. Sixty-five per cent (n = 602) with a low clinical suspicion were discharged and 35% (n = 320) with a high clinical suspicion had same day MRI scan. Fifty-eight scaphoid fractures were diagnosed and treated with no nonunions reported. Anatomical snuff box tenderness was the most sensitive test (90%). A combination of five tests better excluded an occult fracture (80% accuracy). The dedicated scaphoid clinic pathway resulted in 350 fewer follow-up visits and an overall saving of £59,666.Level of evidence: III.

[Osteophyte-induced impingement reduces range of motion in humpback deformity of incorrectly healed scaphoid reconstruction]

BACKGROUND

The gold standard in the treatment of scaphoid pseudarthrosis is reduction, interposition of an iliac crest graft and stabilization with a headless bone (Herbert) screw, aiming to reduce the frequently observed humpback deformity. This study correlated the extent of humpback deformity after scaphoid reconstruction to clinical and radiological postoperative parameters.

MATERIAL AND METHODS

Between 2008 and 2010 a total of 56 patients with scaphoid pseudarthrosis were surgically treated. Of the patients 34 could be included in this retrospective study. The average follow-up period was 7.3 months. The humpback deformity was evaluated by computed tomography (CT) scan performed along the long axis of the scaphoid. The disability of the arm, shoulder and hand (DASH) score, grip strength (Jamar), range of motion (RoM), Mayo wrist score (MWS) and other parameters were used to determine the clinical outcome. The patients were divided into two groups: 1) no or only slight humpback deformity (<25°), 2) severe humpback deformity (>45°).

RESULTS

The RoM and DASH scores were slightly better for the first group. The second group had a significantly increased incidence of osteophyte formation (p < 0.05) and decreased RoM (-16°).

CONCLUSION

It is postulated that the main disadvantage of an nonreduced humpback deformity is the increased occurrence of osteophyte formation in the dorsal aspect of the scaphoid. This can cause an impingement during extension and leads to a significant restriction of movement of the wrist.

LEVEL OF EVIDENCE

III.

Mid-term follow-up of surgically treated and healed scaphoid fractures

The aim of this study was to evaluate the mid-term results of surgically treated scaphoid fractures since we were concerned that good results might deteriorate over time due to osteoarthritis or functional impairment. Thirty-three out of 121 surgically treated patients (isolated scaphoid fractures n = 23; scaphoid fractures with concomitant injuries n = 10) were evaluated retrospectively (47-138 months). Five patients (4%) had a non-union after internal fixation and were excluded because of additional treatment. The remaining 83 patients were not available for a follow-up examination. Patients with an isolated scaphoid fracture had a mean extension-flexion of 68°-0°-64°, a radial-ulnar deviation of 27°-0°-41° and a grip strength of 39 kg (corresponding to 87-98% of the uninjured contralateral wrist), while patients with concomitant injuries had a mean extension-flexion of 60°-0°-44°, radial-ulnar deviation of 22°-0°-38° and a grip strength of 42 kg (corresponding to 73-98% of the uninjured contralateral wrist). The Michigan Hand Questionnaire score was 85 and 75 and the Patient-Rated Wrist Evaluation score was 8 and 21, respectively. Fifteen patients had radiological signs of radiocarpal osteoarthritis with a significantly higher occurrence in those who had concomitant injuries compared to those with isolated scaphoid fractures (p < 0.01). There was no significant group difference in scaphotrapeziotrapezoid (STT) osteoarthritis (p = 0.968). One STT osteoarthritis case occurred after plate fixation, one after antegrade screw fixation and 10 after retrograde screw fixation. Surgical treatment of an acute isolated scaphoid fracture has excellent clinical, functional, and radiologic mid-term results, while scaphoid fractures with concomitant wrist injuries have slightly inferior results.

Percutaneous Scaphoid Fixation: Experience Value among Different Approaches

Background  Percutaneous scaphoid osteosynthesis is an attractive and increasingly popular option, as a treatment for acute scaphoid fractures in selected cases, and as an alternative to conservative treatment. The purpose of this study is to assess the radiographic positioning of the screw in percutaneous scaphoid fixation, taking into consideration the surgeons' experience, and the difference between volar and dorsal approaches. Methods  We retrospectively assessed patients undergoing percutaneous scaphoid fixation from 2013 to 2019. Inclusion criteria are as follows: (1) scaphoid waist fractures (Herbert's B2), (2) a minimum of 18 years of age and a maximum of 55 years of age, (3) dominant hand, (4) manual work, (5) minimum follow-up time of 6 months, and (6) without associated lesions. Criteria for correct positioning are as follows: (1) on the axis or parallel to the scaphoid axis with a maximum deviation of 1.5 mm volar/dorsal, (2) without proximal/dorsal prominence, (3) correct scaphoid alignment/reduction, and (4) absence of threads in the fracture site. Radiographs were evaluated separately by a hand surgeon, a general orthopaedic surgeon, and an orthopaedic resident. Results  With a total of 39 patients, a dorsal approach was performed in 10 patients and a palmar approach in 29 patients. We verified a very good interobserver reliability. The hand surgeon's team correctly positioned 15 (83.3%, 15/18), while the other team did 9 correctly (42.9%, 9/21). Comparing teams according to the approach used, the dorsal approach did not show a statistical difference, while the same was not true for the volar approach ( p  < 0.05). Conclusion  This points to a positive impact on the team's experience in the positioning of the screws, and therefore in the benefit of treatment by teams dedicated to the area, while daring to suggest that less-experienced surgeons should utilize the dorsal approach.

Diagnostic performance of cone-beam computed tomography for scaphoid fractures: a systematic review and diagnostic meta-analysis

Scaphoid fractures are the most common carpal fractures. Diagnosing scaphoid fractures is challenging. Recently, cone-beam computed tomography (CBCT) has been shown to be a promising strategy for diagnosing scaphoid fractures. The diagnostic performance of CBCT remains inconclusive in the literature. Through a systematic review and meta-analysis, our study aims to determine the diagnostic performance of CBCT for diagnosing scaphoid fractures. Five databases were searched up to March 25, 2020. We included prospective and retrospective studies describing the diagnostic accuracy of CBCT for scaphoid fractures in adult patients. QUADAS-2 tool was used to assess the quality of the included studies. Four studies (n = 350) were included in the meta-analysis. Three of the four studies had high bias risk. The result showed that CBCT had a pooled sensitivity of 0.88 and a pooled specificity of 0.99 for scaphoid fracture diagnosis. The heterogeneities of sensitivity and specificity were substantial. The area under the summary receiver operating characteristic curve was 0.98. No significant publication bias was observed. The result suggested that the diagnostic performance of CBCT for scaphoid fracture was excellent. The certainty of current evidence is low. Further well-designed studies with large sample sizes are warranted to confirm this finding.

Age-dependent changes in pediatric scaphoid fracture pattern on radiographs

OBJECTIVE

To systematically investigate age-dependent changes in scaphoid fracture prevalence and fracture patterns on radiographs in children under 15 years of age.

METHODS AND MATERIALS

This retrospective study included children with scaphoid fractures, who underwent radiographic examinations between May 1, 2009, and August 31, 2019. Blinded to outcome, all radiographs were reviewed to determine fracture visibility on initial radiographs; to characterize fracture location (distal corner, distal, mid, and proximal body) and orientation (horizontal oblique, transverse, and vertical oblique); and to identify the presence or absence of gap, displacement, and concomitant fractures. Demographic information and information on weight and height were collected. Mann-Whitney U, Kruskal-Wallis rank sum, chi-square, and post hoc tests were used to investigate associations between age, fracture characteristics, and BMI percentile.

RESULTS

The study included 180 children (134 boys and 46 girls; 12.3 ± 1.4 years) with 59 (33%) distal corner, 42 (23%) distal, 76 (42%) mid, and 3 (2%) proximal body fractures. Younger children were more likely to present with distal corner and distal body fractures while older children with mid and proximal body fractures (p = 0.035). No association was found between age and fracture visibility (p = 0.246), fracture orientation (p = 0.752), presence of gap (p = 0.130), displacement (p = 0.403), or concomitant fractures (p = 0.588). Younger children with scaphoid fractures were more likely to be obese (n = 117; p = 0.038).

CONCLUSION

Scaphoid fractures of the distal corner and distal body were significantly more common in younger children, who are more likely to be obese.

Measurement of Scaphoid Bone Microarchitecture: A Computed Tomography Imaging Study and Implications for Screw Placement

PURPOSE

High bone density and quality is associated with improved screw fixation in fracture fixation. The objective of this study was to assess bone density and quality in the proximal and distal scaphoid to determine optimum sites for placement of 2 screws in scaphoid fracture fixation.

METHODS

Twenty-nine cadaveric human scaphoid specimens were harvested and scanned using micro-computed tomography. Bone density (bone volume fraction) and bone quality (relative bone surface area, trabecular number, and trabecular thickness) were evaluated in 4 quadrants within each of the proximal and distal scaphoid.

RESULTS

The proximal radial quadrant of the scaphoid had significantly greater bone volume than the distal ulnar (mean difference, 33.2%) and distal volar quadrants (mean difference, 32.3%). There was a significantly greater trabecular number in the proximal radial quadrant than in the distal ulnar (mean difference, 16.7%) and in the distal volar quadrants (mean difference, 15.9%) and between the proximal ulnar and the distal ulnar quadrants (mean difference, 12%). There was a significantly greater bone surface area in the proximal radial and distal radial quadrants than in the distal ulnar and distal volar quadrants. There were no significant differences in trabecular thickness between the 8 analyzed quadrants CONCLUSIONS: Although there are differences in bone volume, trabecular number, and bone surface area between the proximal pole of the scaphoid and that of the distal pole, there were no significant differences in the bone quality (trabecular thickness, trabecular number, and relative bone surface area) and density (bone volume fraction) between the 4 quadrants of the proximal or distal pole of the cadaveric scaphoids studied.

CLINICAL RELEVANCE

Insertion of 2 headless compression screws can be determined by ease of surgical access and ease of screw positioning and not by differences in bone quality or density of the proximal or distal scaphoid.

The Effect of Intra-carpal Kirschner Wire Augmentation in Screw Fixation of Scaphoid - A Retrospective Cohort Study

Introduction:

Scaphoid fractures are most often treated with a single headless compression screw. However, intercarpal Kirschner wire (K-wire) might be added to improve stability and fracture outcomes. This study will determine if there is a difference in treatment outcome (union rate and time to union) between scaphoid fracture fixations using a single headless compression screw with and without augmentation using a intracarpal intramedullary K-wire.

Material and Methods:

We conducted a retrospective review of patients who underwent surgery for isolated scaphoid fractures over a 15 years period from December 2000 to December 2015. Only patients who underwent open surgery with bone grafting were included. They were divided into a group treated with a single screw fixation, and another group treated with screw and K-wire fixations.

Results:

Forty-four (58.7%) patients had single screw fixation and 31 (41.3%) had screw augmented with K-wire fixation. The overall union rate was 88.0%, with an overall mean time to union of 5.3 months. There was no difference in union rate (p=0.84) and time to union (p=0.66) between the single screw group and combined screw and K-wire group. Univariate analysis found that older age (t=-2.11, p=0.04) had a significant effect on union rate. Regression model showed that age had a significant effect on months to union.

Conclusion:

In open fixation of scaphoid fractures with compression screw and bone grafting, union rate and time to union is comparable whether or not screw fixation was augmented with an intracarpal K-wire. There was no increased risk of complications associated with augmented screw. Age of patient affected time to union and union rate.

Has NICE guidance changed the management of the suspected scaphoid fracture: A survey of UK practice

INTRODUCTION

Despite scaphoid fractures being relatively uncommon pro-active treatment of suspected fractures has been seen as a risk management strategy. The poor positive predictive value of X-rays has led to published guidelines advocating MRI as a first-line or early imaging tool. It is unclear whether UK hospitals have been able to introduce early scanning and this national survey sought to establish the current management strategies for patients with a suspected scaphoid fracture.

METHOD

An electronic survey of UK emergency departments (ED) was conducted to establish the initial and follow up strategies for patients with negative imaging. Comparison of first and second-line imaging modalities was undertaken together with review of the clinical speciality responsible for ongoing management.

RESULTS

166 UK NHS Trusts were identified with emergency department facilities of which 66 (39.8%) responded. All sites perform an X-ray as the initial examination. For those with a negative examination ED follow up was the most common approach (54.6%), although many sites refer patients to other specialities including orthopaedics (39.4%) for follow up. The data demonstrated inconsistencies in the number of follow-up episodes and the different imaging investigations utilised. Frustration with the challenges presented by this patient cohort was evident.

CONCLUSION

The suspected scaphoid fracture represents an ongoing challenge to the NHS with many resource intensive pathways reliant on access to complex imaging investigations.

IMPLICATIONS FOR PRACTICE

Our study identified that UK Emergency Departments have limited early access to complex imaging for scanning of the scaphoid. A range of strategies are used for follow up of suspected scaphoid fractures and these are resource intensive. Overtreatment of patients with suspected scaphoid fracture is used as a risk management approach.

Epidemiology of scaphoid fractures and non-unions: A systematic review

BACKGROUND

The scaphoid is the most commonly fractured carpal bone in adults as well as in children. Previous studies have reported a wide range of fracture incidences. Scaphoid fractures and non-unions in children have been sparsely investigated.

AIM

To perform a systematic review of the current literature on epidemiology of scaphoid fractures and non-unions in adults and children.

METHODS

An electronic literature search was conducted investigating all studies in the literature published between January 1989 and June 23 2020. The systematic review following the PRISMA guidelines and searching in PubMed, Embase, Web of Science and Cochrane library databases was done in June 2020.

RESULTS

42 studies met our inclusion criteria, 6 studies were prospective, 32 were retrospective and 4 were register studies. The majority of studies relied on conventional radiographs for diagnosis. Scaphoid fractures in adults are predominately found in males with a peak incidence in the age group from 20 to 29 years. Incidence rates in males are reported from 107 to 151/100 000. Females have an earlier peak, in the age group 10 to 19 years, with an incidence from 14 to 46/100 000. Most fractures occur in the middle third of the scaphoid representing 60-69 % of cases. Scaphoid fractures in children are predominately found in boys age 12 and above, while it seldomly occur for children younger than 9 years. In adults the risk for developing a scaphoid non-union is between 2 % and 5 %, the majority affecting males and predominately located at the middle third of the scaphoid. Non-unions among children are rare and mainly due to missed or delayed diagnosis of a fracture in the middle third of the scaphoid.

CONCLUSION

This review revealed a substantial heterogeneity among studies concerning study population, diagnosis criterial and outcome measures. Currently, evidence on epidemiology for scaphoid fractures and non-unions are low.

Determining diagnosis of scaphoid healing: Comparison of cone beam CT and X-ray after six weeks of immobilization

PURPOSE

To assess the accuracy and reliability of using cone beam computed tomography (CBCT) compared to X-ray six weeks after injury for predicting scaphoid union.

MATERIALS AND METHODS

Overall; 52 patients with scaphoid fractures between April 2018 and March 2019 were prospectively included in this study. The mean age was 34.52 (13-88) years, and the gender ratio male/female 43/9. Of the fractures, 26 had occurred on the right side, and 26 on the left side. In total, 28 % of patients were manual workers. All patients underwent X-ray and CBCT six weeks after injury. Four readers, two radiologists, and two hand surgeons analyzed the findings using double-blinded X-ray and CBCT and categorized fractures as consolidated based on a 50 % visibility threshold concerning trabecular bridges. Proximal pole sclerosis, communition, cyst formation, and humpback deformity were similarly analyzed for all cases. Agreement between readers was calculated using Kappa, and sensitivity, specificity, and accuracy using RStudio software. The gold standard was the radiologic and clinical follow-up for all patients at two months.

RESULTS

Inter-reader agreement between the four readers was moderate concerning X-ray (0.543) but substantial concerning CBCT (0.641). It was almost perfect between seniors regarding CBCT (Kappa = 0.862). Sensitivity, specificity, and accuracy were 0.75-0.78, 0.4, and 0.61-0.64, respectively, for two readers regarding CBCT. The X-ray values were 0.65-0.71, 0.35-0.4, and 0.53-0.59, respectively.

CONCLUSION

CBCT proves more accurate and reliable than X-ray for diagnosing scaphoid union at an early follow-up and prevents longer immobilization and interruption of activity or work.

Costo-osteochondral graft (rib graft) reconstruction of the irreparable proximal scaphoid

We present our series of 21 cases in which proximal scaphoid nonunions with fragmentation were treated with costo-osteochondral graft reconstruction (rib graft). The median follow-up was 29 months. Union was achieved in all 21 patients. There were significant improvements in subjective and objective outcome measurements and carpal alignment was well maintained in all patients, as shown by normal postoperative capitolunate angle measurements. No donor site complications were encountered. Rib graft reconstruction offers a reliable and straightforward option for the difficult problem of the irreparable proximal pole of the scaphoid.Level of evidence: IV.

Scaphoid Malunion Clinical and Radiographic Outcomes at a Minimum of 4 Years Follow-Up

PURPOSE

To evaluate the radiographic and clinical outcomes of patients with scaphoid malunion after acute fracture at a mean of 7 years after injury.

METHODS

Patients with scaphoid malunion were identified from a departmental database of acute scaphoid fractures. Patients with a scaphoid height-to-length ratio greater than 0.6 on final follow-up computed tomography (CT) scan were considered malunited. These patients were contacted to return for CT imaging and clinical assessment. A total of 22 patients were included (4 females and 18 males). Average age of the group was 41 years (range, 16-64 years) and average length of follow-up was 7.4 years (range, 4.4-11.8 years) after injury.

RESULTS

Ten patients who underwent CT imaging demonstrated arthritic changes at the radial styloid, scaphoid fossa, or scaphotrapeziotrapezoid joint(s). Despite this, patients had good clinical function that was not significantly different compared with the uninjured side. Patients reported minimal pain and disability based on patient-reported outcome measures, and there was a moderate correlation between passive range of motion and height-to-length ratio.

CONCLUSIONS

Nearly half of all patients with malunited acute scaphoid fractures demonstrated radiographic findings of early arthritis on CT imaging but overall good clinical results on midterm follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.