Aims. Occult (clinical) injuries represent 15% of all scaphoid fractures, posing significant challenges to the clinician. MRI has been suggested as the gold standard for diagnosis, but remains expensive, time-consuming, and is in high demand. Conventional management with immobilization and serial radiography typically results in multiple follow-up attendances to clinic, radiation exposure, and delays return to work. Suboptimal management can result in significant disability and, frequently, litigation. Methods. We present a service evaluation report following the introduction of a quality-improvement themed, streamlined, clinical scaphoid pathway. Patients are offered a removable wrist splint with verbal and written instructions to remove it two weeks following injury, for self-assessment. The persistence of pain is the patient’s guide to ‘opt-in’ and to self-refer for a follow-up appointment with a senior emergency physician. On confirmation of ongoing signs of clinical scaphoid injury, an urgent outpatient ‘fast’-wrist protocol MRI scan is ordered, with instructions to maintain wrist immobilization. Patients with positive scan results are referred for specialist orthopaedic assessment via a virtual fracture clinic. Results. From February 2018 to January 2019, there were 442 patients diagnosed as clinical scaphoid fractures. 122 patients (28%) self-referred back to the emergency department at two weeks. Following clinical review, 53 patients were discharged; MRI was booked for 69 patients (16%). Overall, six patients (< 2% of total; 10% of those scanned) had positive scans for a scaphoid fracture. There were no known missed fractures, long-term non-unions or malunions resulting from this pathway. Costs were saved by avoiding face-to-face clinical review and MRI scanning. Conclusion. A patient-focused opt-in approach is safe and effective to managing the suspected occult (clinical) scaphoid fracture. Cite this article: Bone Jt Open 2024;5(2):117–122

Aims. Current National Institute for Health and Clinical Excellence (NICE) guidance advises that MRI direct from the emergency department (ED) should be considered for suspected scaphoid fractures. This study reports the current management of suspected scaphoid fractures in the UK and assesses adherence with NICE guidance. Methods. This national cross-sectional study was carried out at 87 NHS centres in the UK involving 122 EDs and 184 minor injuries units (MIUs). The primary outcome was availability of MRI imaging direct from the ED. We also report the specifics of patient management pathways for suspected scaphoid fractures in EDs, MIUs, and orthopaedic services. Overall, 62 of 87 centres (71%) had a guideline for the management of suspected scaphoid fractures. Results. A total of 11 of 87 centres (13%) had MRI directly available from the ED. Overall, 14 centres (17%) used cross-sectional imaging direct from the ED: MRI in 11 (13%), CT in three (3%), and a mixture of MRI/CT in one (1%). Four centres (6%) used cross-sectional imaging direct from the MIU: MRI in three (4%) and CT in two (2%). Of 87 centres’ orthopaedic specialist services, 74 (85%) obtained repeat radiographs, while the most common form of definitive imaging used was MRI in 55 (63%), CT in 16 (19%), mixture of MRI/CT in three (3%), and radiographs in 11 (13%). Conclusion. Only a small minority of centres currently offer MRI directly from the ED for patients with a suspected scaphoid fracture. Further research is needed to investigate the facilitators and barriers to the implementation of NICE guidance. Cite this article: Bone Jt Open 2021;2(11):997–1003

Aims. The underlying natural history of suspected scaphoid fractures (SSFs) is unclear and assumed poor. There is an urgent requirement to develop the literature around SSFs to quantify the actual prevalence of intervention following SSF. Defining the risk of intervention following SSF may influence the need for widespread surveillance and screening of SSF injuries, and could influence medicolegal actions around missed scaphoid fractures. Methods. Data on SSF were retrospectively gathered from virtual fracture clinics (VFCs) across a large Scottish Health Board over a four-year period, from 1 January 2018 to 31 December 2021. The Bluespier Electronic Patient Record System identified any surgical procedure being undertaken in relation to a scaphoid injury over the same time period. Isolating patients who underwent surgical intervention for SSF was performed by cross-referencing the unique patient Community Health Index number for patients who underwent these scaphoid procedures with those seen at VFCs for SSF over this four-year period. Results. In total, 1,739 patients were identified as having had a SSF. Five patients (0.28%) underwent early open reduction and internal fixation (ORIF). One patient (0.06%) developed a nonunion and underwent ORIF with bone grafting. All six patients undergoing surgery were male (p = 0.005). The overall rate of intervention following a SSF was 0.35%. The early intervention rate in those undergoing primary MRI was one (0.36%), compared with three in those without (0.27%) (p > 0.576). Conclusion. Surgical intervention was rare following a SSF and was not required in females. A primary MRI policy did not appear to be associated with any change in primary or secondary intervention. These data are the first and largest in recent literature to quantify the prevalence of surgical intervention following a SSF, and may be used to guide surveillance and screening pathways as well as define medicolegal risk involved in missing a true fracture in SSFs. Cite this article: Bone Jt Open 2024;5(4):312–316

Aims. To explore individuals’ experience of a scaphoid waist fracture and its subsequent treatment. Methods. A purposive sample was created, consisting of 49 participants in the Scaphoid Waist Internal Fixation for Fractures Trial of initial surgery compared with plaster cast treatment for fractures of the scaphoid waist. The majority of participants were male (35/49) and more younger participants (28/49 aged under 30 years) were included. Participants were interviewed six weeks or 52 weeks post-recruitment to the trial, or at both timepoints. Interviews were semistructured and analyzed inductively to generate cross-cutting themes that typify experience of the injury and views upon the treatment options. Results. Data show that individual circumstances might exaggerate or mitigate the limitations associated with a scaphoid fracture, and that an individual’s sense of recovery is subjective and more closely aligned with perceived functional abilities than it is with bone union. Misconceptions that surgery promises a speedier and more secure form of recovery means that some individuals, whose circumstances prescribe a need for quick return to function, express a preference for this treatment modality. Clinical consultations need to negotiate the imperfect relationship between bone union, normal function, and an individual’s sense of recovery. Enhancing patients’ perceptions of regaining function, with removable splints and encouraging home exercise, will support satisfaction with care and discourage premature risk-taking. Conclusion. Clinical decision-making in the management of scaphoid fractures should recognize that personal circumstances will influence how functional limitations are experienced. It should also recognize that function overrides a concern for bone union, and that the consequences of fractures are poorly understood. Where possible, clinicians should reinforce in individuals a sense that they are making progress in their recovery. Cite this article: Bone Jt Open 2022;3(8):641–647

The primary aim of this study was to identify the rate of osteoarthritis in scaphoid fracture non-union. We also aimed to investigate whether the incidence of osteoarthritis correlates with the duration of non-union(interval), and to identify the variables that influence the outcome. We retrospectively reviewed 273 scaphoid fracture non-union presented between 2007 and 2016. Data included patient demographics, interval, fracture morphology, grade of osteoarthritis (Kellgren-Lawrence) and scaphoid non-union advanced collapse (SNAC), and overall health-related quality of life. Patients were divided into two groups (SNAC and Non-SNAC). Group differences were analysed using Mann-Whitney U test and association with Pearson's correlations. A two-sided p-value of <0.05 was considered significant. The scaphoid fracture non-union were confirmed on CT scans (n=243) and plain radiographs (n=35). The subjects were 32 females and 260 males with the mean age of 33.8 years (SD, 13.2). The average interval was 3.1 years (range, 0–45 years). Osteoarthritis occurred in 58% (n=161) of non-unions, and 42% (n=117) had no osteoarthritis. In overall, 38.5% (n=107) had SNAC-1, 9% (n=25) with SNAC-2, and 10.4% (n=29) presented with SNAC-3. The mean interval in the non-SNAC group was 1.2 years, and in SNAC 1,2, and 3 were 2.6, 6.8, and 11.1 years, respectively. The average summary index in SNAC and non- SNAC groups was 0.803 and 0.819, respectively. Our results also showed a significant correlation between advanced osteoarthritis and proximal fracture non-unions(P<0.05). We concluded that there is no clear correlation between the interval and the progression of osteoarthritis. SNAC was more likely to occur in fractures aged 2 years or older

Background. Scaphoid fracture malunion with flexion and shortening results in the ‘humpback deformity’. This is thought to be associated with poor clinical results when assessed with the lateral intra-scaphoid angle and the Green and O'Brien wrist evaluation scale. This method of deformity measurement is now considered unreliable and the functional score has not been validated in the setting of scaphoid fractures. Aims & objectives. To assess the outcome of scaphoid malunion at one year using the height to length ratio, a reliable measure of deformity, and the Patient Evaluation Measure (PEM), a functional assessment validated specifically for scaphoid fracture outcome. Material & methods. Forty-two consecutive patients with a united scaphoid fracture were prospectively evaluated one year following injury. All had been treated in a below elbow colles plaster for up to 12 weeks. Fracture union was confirmed at 12-18 weeks post-injury with longitudinal CT scans. Scaphoid malunion was quantified with the height to length ratio measured on CT images by two observers. A blind clinical assessment was made and all patients completed the PEM questionnaire. The group consisted of 38 males and 4 females with a mean age of 31 years at the time of injury. Results. 23 out of 42 patients were judged to have scaphoid malunion. Grip strength, range of motion and PEM scores were not significantly different between the malunited fractures and those fractures that united without deformity (Grip Strength: 95% vs. 100% of the normal side; ROM: 98% vs. 99% and PEM: 7% vs. 10% respectively, p>0.066). Conclusions. We found scaphoid fractures that had united with a humpback deformity resulted in a 5% reduction in hand grip strength, but no significant reduction in range of motion or functional impairment using the validated PEM

Purpose. Knowing the morphology of any fracture, including scaphoid fractures, is important in order to determine the fracture stability and the appropriate fixation technique. Scaphoid fractures are classified according to their radiographic appearance, and simple transverse waist fractures are considered the most common. There is no description in the literature of the 3-dimensional morphology of scaphoid fractures. Our hypothesis was that most scaphoid fractures are not perpendicular to its long axis, i.e. they are not simple transverse fractures. Methods. A 3-dimensional analysis was performed of CT scans of acute scaphoid fractures, conducted at two medical centres during a period of 6 years. A total of 124 scans were analysed (Amira Dev 5.3, Visage Imaging Inc). Thirty of the fractures were displaced and virtually reduced. Anatomical landmarks were marked on the distal radius articular surface in order to orient the scaphoid in the wrist. Shape analysis of the scaphoids and a calculation of the best fitted planes to the fractures were carried out implementing principal component analysis. The angles between the scaphoid's first principal axis to the fracture plane, articular plane and to the palmar-dorsal direction were measured. The fractures were analysed both for location (proximal, waist and distal) and for displacement. Results. There were 86 fractures of the waist (76 percent), 13 of the distal third and 25 of the proximal third. The average angle between the first principal axis of the scaphoid and the fracture plane was 52.6 degrees (SD 17) for all fractures, 55.6 degrees (SD 17.2) for the waist fractures, both differing significantly from a right angle (p<0.001). The majority of fractures were found to be horizontal oblique. We found no difference between the angles of the waist fractures which were displaced and those that were not displaced. In contrast, a significant difference was found between the displaced and non-displaced fractures when evaluating the orientation of the scaphoid long axis in relation to the articular plane (139.8 degrees with reduction versus 148.2 without; p=0.036). Conclusions. Most waist fractures were found to be horizontal oblique in relation to the long axis of the scaphoid and not transverse. Although the fracture angle could not explain displacement of the fracture, we found that the orientation of the scaphoid's long axis in relation to the radial articular surface was correlated with fracture displacement. According to these findings, fixation of all fractures along the long axis of the scaphoid should not be the optimal mode of fixation. Optimal fixation of acute scaphoid fractures may call for better analysis of each fracture configuration and the fixation should be guided by this analysis

Purpose. Knowing the morphology of any fracture, including scaphoid fractures, is important in order to determine the fracture stability and the appropriate fixation technique. Scaphoid fractures are classified according to their radiographic appearance, and simple transverse waist fractures are considered the most common. There is no description in the literature of the 3-dimensional morphology of scaphoid fractures. Our hypothesis was that most scaphoid fractures are not perpendicular to its long axis, i.e. they are not simple transverse fractures. Methods. A 3-dimensional analysis was performed of CT scans of acute scaphoid fractures, conducted at two medical centers during a period of 6 years. A total of 124 scans were analysed (Amira Dev 5.3, Visage Imaging Inc). Thirty of the fractures were displaced and virtually reduced. Anatomical landmarks were marked on the distal radius articular surface in order to orient the scaphoid in the wrist. Shape analysis of the scaphoids and a calculation of the best fitted planes to the fractures were carried out implementing principal component analysis. The angles between the scaphoid's first principal axis to the fracture plane, articular plane and to the palmar-dorsal direction were measured. The fractures were analysed both for location (proximal, waist and distal) and for displacement. Results. There were 86 fractures of the waist (76 percent), 13 of the distal third and 25 of the proximal third. The average angle between the first principal axis of the scaphoid and the fracture plane was 52.6 degrees (SD 17) for all fractures, 55.6 degrees (SD 17.2) for the waist fractures, both differing significantly from a right angle (p<0.001). The majority of fractures were found to be horizontal oblique. We found no difference between the angles of the waist fractures which were displaced and those that were not displaced. In contrast, a significant difference was found between the displaced and non-displaced fractures when evaluating the orientation of the scaphoid long axis in relation to the articular plane (139.8 degrees with reduction versus 148.2 without; p=0.036). Conclusions. Most waist fractures were found to be horizontal oblique in relation to the long axis of the scaphoid and not transverse. Although the fracture angle could not explain displacement of the fracture, we found that the orientation of the scaphoid's long axis in relation to the radial articular surface was correlated with fracture displacement. According to these findings, fixation of all fractures along the long axis of the scaphoid should not be the optimal mode of fixation. Optimal fixation of acute scaphoid fractures may call for better analysis of each fracture configuration and the fixation should be guided by this analysis

Background. In suspected scaphoid fracture the initial scaphoid series plain radiographs are 84-94% sensitive for scaphoid fractures. Patients are immobilised awaiting diagnosis. Unnecessary lengthy immobilisation leads to lost productivity and may leave the wrist stiff. Early accurate diagnosis would improve patient management. Although Magnetic Resonance Imaging (MRI) has come to be regarded as the gold standard in identifying occult scaphoid injury, recent evidence suggests Computer Tomography (CT) to be more accurate in identifying scaphoid cortical fracture. Additionally CT and USS are frequently a more available resource than MRI. We hypothesised that 16 slice CT is superior to high spatial resolution Ultrasonography (USS) in the diagnosis of radiograph negative suspected cortical scaphoid fracture and that a 5 point clinical examination will help to identify patients most likely to have sustained a fracture within this group. Methods. 100 patients with two negative scaphoid series and at least two out of five established clinical signs of scaphoid injury (anatomical snuffbox tenderness (AST), scaphoid tubercle tenderness (STT), effusion, pain on circumduction and pain on axial loading) were prospectively investigated with CT and USS. MRI was arranged for patient with persistent symptoms but negative CT/USS. Results. CT demonstrated 8 scaphoid fractures. 17 other fractures (1st metacarpal, trapezium, trapezoid, distal radius, hook of hammate and triquetral) were also found. USS diagnosed 2/8 scaphoid fractures, raised suspicion in 5/8 and completely missed 1/8. Combining AST, STT with pain on circumduction improved accuracy (sensitivity 87.5% and Specificity 36%). No further fractures were identified on MRI. Conclusions. - CT remains superior to USS for the exclusion of cortical scaphoid fracture. There remains a role for USS if resources are limited. - Combining signs of ASB and tubercle tenderness with pain on circumduction assists in the identification of a ‘fracture likely’ subgroup

Introduction. Up to 16% of scaphoid fractures are radiologically occult; failure to diagnose scaphoid fractures may lead to delayed union, nonunion or avascular necrosis. Fractures may take weeks to be excluded and many patients are unnecessarily immobilised increasing work absence, clinical reviews and cost. The use of CT early in the management of suspected occult scaphoid fractures has been evaluated. Methods. The radiology and clinical notes of all patients that had scaphoid CT scans over the preceding 3 years were retrospectively reviewed. 84 patients that had CT scans within 14 days from injury were identified. Results. 64% of CTs excluded fracture (N=54) and these patients were mobilised promptly and reviewed within six weeks. No patients returned with any complications, such as carpal instability, from this management strategy. Mean number of clinic appointments for this group was 2.34 (range 2–6). 36% of CTs were abnormal (N=30). 7% revealed occult scaphoid fractures; 18% revealed occult carpal fractures of the triquetrum, capitate and lunate respectively and 5% distal radius fractures. All patients diagnosed with fractures were successfully managed with plaster immobilisation, with one case of regional pain syndrome. Conclusions. Early CT immediately alters therapeutic decision making in suspected occult fractures preventing unnecessary immobilisation. Early CT also reduces clinic attendances for clinical and radiological review without increase in cost

The aim of the study was to investigate, firstly, the force distribution between scaphoid/radius and lunate/radius in the normal wrist and in the presence of a scaphoid fracture, secondly, how stresses and strains at the fractured area change during the healing process and thirdly, how the direction of the applied forces affects load transmission. A 3D finite element model of the normal wrist was initially developed. Two typical scaphoid fractures B2 and B3 according to Herbert’s classification, were investigated. The fractured areas were modeled with a range of modulus of elasticity to resemble the various stages of the healing process. Furthermore, three different directions of the externally applied loads were examined. The applied compressive vertical load in the normal joint was transmitted to the radius through the radioscaphoid and the radiolunate articular surfaces at a ratio equal to 56:46 respectively. The ratio was equal to 54:48 and 53:49 for the B2 and the B3 fracture respectively. The load direction resembling an ulnary deviated wrist caused the appearance of a significantly higher strain field at the fractured area. The maximum developed stresses at the fractured area for scaphoid fracture B2 were approximately 37%–58% higher than those of B3, for all three loading directions. Based on our results, the onset of osteoarthritic changes in a wrist with a scaphoid fracture is due to carpal collapse and scaphoid deformity. The recorded maximum developed strains for both B2 and B3 scaphoid fractures suggested intense bone remodeling activity. Among the examined three different load directions, the one simulating an ulnary deviated wrist corresponded to the most severe effects

Introduction. Scaphoid fracture is the most common undiagnosed fracture. Occult scaphoid fractures occur in 20-25 percent of cases where the initial X-rays are negative. Currently, there is no consensus as to the most appropriate investigation to diagnose these occult frctures. At our institution MRI has been used for this purpose for over 3 years. We report on our experience and discuss the results. Materials and methods. All patients with occult scaphoid fractures who underwent MRI scans over a 3 year period were included in the study. There was a total of 619 patients. From the original cohort 611 (98.7%) agreed to have a scan, 6 (0.97%) were claustrophobic and did not undergo the investigation and 2 (0.34%) refused an examination. 86 percent of the cases were less than 30 years of age. Imaging was performed on a one Tiesla Siemen's scanner using a dedicated wrist coil. Coronal 3mm T1 and STIR images were obtained using a 12cm field of view as standard. Average scanning time was 7 minutes. Results. The majority of the scans were performed within 2 weeks of the request. The breakdown of results is as follows: Normal 45%; Scaphoid bruise 10%; Scaphoid fracture 9%; Distal radius fracture 8%; Distal radius bruise 7%; TFCC tear 4%; Wrist ganglion 3%; Basal thumb arthritis 3%; Miscellaneous 12%. We did not have any missed scaphoid fractures during this period. Conclusions. Patients with a clinically suspected scaphoid fracture could have a wide range of possible diagnoses. Almost half the patients had a negative scan and therefore did not require further immobilisation/activity restriction. It is possible to perform MRIs within a reasonable timeframe in a DGH setting. Patient acceptance was very high (99%). There were no missed diagnoses. Scaphoid bruising could be picked up and consequently unnecessary immobilisation avoided. In patients with other diagnoses a reliable prognosis could be given

Percutaneous fixation of scaphoid fractures has become popular in recent years, mainly due to its reduced complexity compared to open surgical approaches. Fluoroscopy is currently used as guidance for this percutaneous approach, however, as a projective imaging modality, it provides only a 2D view of the complex 3D anatomy of the wrist during surgery, and exposes both patient and physician to harmful X-ray radiation. To avoid these drawbacks, 3D ultrasound has been suggested to provide imaging for guidance as a widely available, real-time, radiation-free and low-cost modality. However, the blurred, disconnected, weak and noisy bone responses render interpretation of the US data difficult so far. In this work, we present the integration of 3D ultrasound with a statistical wrist model to allow development of an improved ultrasound-based guidance procedure. For enhancement of bone responses in ultrasound, a phase symmetry based approach is used to exploit the symmetry of the ultrasound signal around the expected bone location. We propose an improved estimation of the local phase symmetry by using the local spectrum variation of the ultrasound image. The statistical wrist model is developed through a group-wise registration based framework in order to capture the major modes of shape and pose variations across 30 subjects at different wrist positions. Finally, the statistical wrist model is registered to the enhanced ultrasound bone surfaces using a probabilistic registration approach. Feasibility experiments are performed using two volunteer wrists, and the results are promising and warrant further development and validation to enable ultrasound guided percutaneous scaphoid fracture reduction

We describe a new technique for fixing the proximal pole scaphoid fractures both in acute and chronic setting and present our preliminary results. We prospectively studied fixation of 25 proximal pole scaphoid fractures (1 acute displaced and 24 non unions) with this technique between 1999 and 2007. Mean age of patients was 25 years and mean time to the operation was 6 months. The technique involves making a transverse dorsal incision over the radius along the radio-carpal junction. The retinaculum is split in line with its fibres. Access to the radio-carpal joint is achieved through the third extensor compartment. The ligament attachment to the scaphoid is preserved by using a modified Mayo approach. A window is created initially at the proximal end of the dorsal ridge. The fracture is reduced and stabilised with an appropriate length Herbert screw. The fracture site is curetted through this window and cancellous bone graft from the distal radius is packed into the fracture site. The capsule and extensor retinaculum is then closed in layers. Radiological union was achieved in 23 cases, one case required refixation and one case was lost to follow up. Our technique is tendon sparing, capsule retaining, and ensures maintenance of articular surface congruity. So far this technique has led to excellent results

Introduction. Scaphoid fractures are commonly treated with a single headless screw. There are different recommendations regarding the optimal location of this screw. The purpose of this study was to compare the location of screws placed for the treatment of acute scaphoid fractures with theoretical and virtual screw locations. Materials and Methods. 10 patients with acute scaphoid fractures treated surgically and with available pre- and postoperative CT scans were included. The scans were analysed using a 3D software model (Amira Dev 5.3, Mercury Computer Systems, Chelmsford, MA). On the preoperative CTs the displaced fractures were virtually reduced. Possible screw locations for fracture fixation were examined including one along the central third of the proximal fragment (central base screw), the scaphoid longitudinal axis calculated mathematically (PCA screw) and a screw placed perpendicular to the fracture plane (90 degree screw). The angle between the axes and fracture plains were measured. The angle and distance between the actual screw on the postoperative CT and the different virtual screw locations were measured as well. Results. The angles between the actual and virtual screws to the fracture plane were between a mean of 67 to 69 degrees. The angle between the axes was greatest between the 90 degree screws to the PCA and actual screws (mean 23 degrees both; p=0.034) and smallest between the central base screws and PCA to the actual screws (mean of 12.1 and 12.5 degrees, respectively; p=0.034). The difference between the entrance and exit points between the axes was between 3.1 to 4.8 mm other than the 90 degree screws which were 5.3 to 7.1 mm to the other axes (p=0.002). The PCA (mean 28.3 mm) were found to be longer than the actual screws (mean 25.4) or the 90 degree screws (mean 23.5) (p=0.034 and p=0.008 respectively). The 90 degree screws were shorter than the PCA or central base screws (p=0.008, p=0.034 respectively), but not the actual screws. Discussion. There were no significant differences in the angles between actual and virtual optimal screws other than the 90 degree screws. The PCA was found to be the longest screw and at a similar angle to the fractures as the other virtual screw options, other than the shorter 90 degree screw. Virtual reduction and preplanning of the screw location, using standard software, may enable the surgeon to place the longest screw along the PCA longitudinal axis. If placing a 90 degree screw is considered, this may be technically difficult or may necessitate a trans-trapezial approach

The purpose of this study is to introduce our technique of free hand screw insertion for scaphoid fractures and clarify the indications of this procedure. From 1988 to date, we performed this method in 86 cases (75 males and 11 females). Ages ranged from 11 to 73 years (av.: 29). There were 24 cases of acute stable type, 46 of acute unstable and 16 of delayed fibrous union. Screws used were original Herbert screws in 48, other cannulated type screws in 38. Using an image intensifier, from a small skin incision over the scaphotrapezium joint, a Kirschner wire is inserted to stabilize the fracture temporarily. The wire is pulled volarward to rotate the scaphoid and a second wire is inserted along the intended line of the screw. With the original Herbert screw, after removing the wire, the screw is inserted free-hand. With the other cannulated screws, the second wire is used as guide pin. Results of 82 cases with follow-up times over 6 months were reviewed. In one case, bony fusion was achieved but revealed symptomatic malunion. In two cases, bony fusion was not achieved. In one of them, an additional bone graft was performed, and good bony union was achieved. In the remaining 79 cases, good bony fusion and good clinical results were achieved. The best indication for this method is an acute unstable fracture. For acute stable fractures, we recommend this method for three types of patients: those who cannot accept long term immobilization, those who desire to return to athletic activities as soon as possible, and those who also have another fracture in the forearm. It can also be used in cases of delayed fibrous union when good alignment can be achieved and a bone graft is unnecessary

Aims

The evidence demonstrating the superiority of early MRI has led to increased use of MRI in clinical pathways for acute wrist trauma. The aim of this study was to describe the radiological characteristics and the inter-observer reliability of a new MRI based classification system for scaphoid injuries in a consecutive series of patients.

Objective. To compare the ability of a new composite bio-absorbable screw and two conventional metal screws to maintain fixation of scaphoid waist-fractures under dynamic loading conditions. Methods. Fifteen porcine radial carpi, with morphology comparable to human scaphoids, were osteotomised at the waist. Specimens were randomised in three groups: Group I were fixed with a headed metal screw, group II with a headless tapered metal screw and group III with a bio-absorbable composite screw. Each specimen was oriented at 45° and cyclically loaded using four blocks of 1000 cycles, with peak loads of 40, 60 (normal load), 80 and 100 N (severe load) respectively. Permanent displacement and translation (step-off) at the fracture site was measured after each loading block from a standardised high-magnification photograph using image analysis software (Roman v1.70, Institute of Orthopaedics, Oswestry). Statistical analysis was by ANOVA and tolerance limits. Results. No gross failure or fracture gap displacement occurred. Average translations (step-off) at the fracture site after 4000 cycles up to 100N were 0.05mm±0.02SD (headed metal), 0.14mm±0.14SD (headless metal) and 0.29mm±0.11SD (composite) and differed significantly (p<0.01). Using tolerance limits, the data allowed us to predict that, with 95% certainty, the maximum average translation (step-off) following severe loading in 95% of any sample fixed with a headed metal screw will be below 0.17mm, headless metal screw below 0.74mm, and composite screw below 0.76mm. Conclusion. We observed only small average translations (step-off) for all three screws. Moreover, translations of more than 1mm that would predispose to non-union were highly unlikely for any of the screws, even after severe cyclic loading. We therefore conclude that a new bio-absorbable composite screw can serve as an alternative to conventional screws when fixing scaphoid fractures

Objective: To compare the ability of a new composite bio-absorbable screw and two conventional metal screws to maintain fixation of scaphoid waist-fractures under dynamic loading conditions. Methods: Fifteen porcine radial carpi, whose morphology is comparable to that of human scaphoids, were osteotomized at the waist. Specimens were randomized in three groups: those in group I were fixed with a headed metal screw, in group II with a headless tapered metal screw, and in group III with a bio-absorbable composite screw. Each specimen was oriented at 45° and cyclically loaded using four blocks of 1000 cycles, with peak loads of 40, 60, 80 and 100 N, respectively. In case of gross failure the number of cycles to failure was determined. Otherwise, permanent displacement at the fracture site was measured after each loading block from a standardized high-magnification photograph using image analysis software (Roman v1.70, Institute of Orthopaedics, Oswestry). Statistical analysis was by ANOVA and tolerance limits. Results: Nogross failure occurred. Average displacements after 4000 cycles up to 100N were 0.05mm±0.03SD (headed metal), 0.15mm±0.16SD (headless metal) and 0.29mm±0.11SD (composite) and differed significantly (p< 0.02). Using tolerance limits, the data allowed us to predict that with 95% certainty, displacement in 95% of any sample fixed with a headed metal screw will be below 0.17mm, headless metal screw below 0.84mm, and composite screw below 0.76mm. Conclusion: Comparing two types of conventional metal screws and a new composite bio-absorbable screw to maintain scaphoid fixation under cyclic loading conditions, we found small average fracture displacements for all three screws. Moreover, even following severe cyclic loading conditions, clinically meaningful displacements of more than 1 mm are highly unlikely for any of the three screws. We therefore conclude that a new bio-absorbable composite screw can serve as an alternative to conventional screws when fixing scaphoid fractures