Volar Locking Plates (VLP) have revolutionised the treatment of distal radius fractures allowing the anatomic reduction and stable fixation of the more comminuted and unstable of fractures. The benefits of this in terms of range of movement (ROM), pain and earlier return to work and daily activities is documented. However we were interested in was what improvements in wrist function patients made from 6 to 12 months after injury?

Distal radius fractures have an incidence rate of 17.5% among all fractures. Their treatment in case of comminution, commonly managed by volar locking plates, is still challenging. Variable-angle screw technology could counteract these challenges. Additionally, combined volar and dorsal plate fixation is valuable for treatment of complex fractures at the distal radius. Currently, biomechanical investigation of the competency of supplemental dorsal plating is scant. The aim of this study was to investigate the biomechanical competency of double-plated distal radius fractures in comparison to volar locking plate fixation. Complex intra-articular distal radius fractures AO/OTA 23-C 2.1 and C 3.1 were created by means of osteotomies, simulating dorsal defect with comminution of the lunate facet in 30 artificial radii, assigned to 3 study groups with 10 specimens in each. The styloid process of each radius was separated from the shaft and the other articular fragments. In group 1, the lunate facet was divided to 3 equally-sized fragments. In contrast, the lunate in group 2 was split in a smaller dorsal and a larger volar fragment, whereas in group 3 was divided in 2 equal fragments. Following fracture reduction, each specimen was first instrumented with a volar locking plate and non-destructive quasi-static biomechanical testing under axial loading was performed in specimen's inclination of 40° flexion, 40° extension and 0° neutral position. Mediolateral radiographs were taken under 100 N loads in flexion and extension, as well as under 150 N loads in neutral position. Subsequently, all biomechanical tests were repeated after supplemental dorsal locking plate fixation of all specimens. Based on machine and radiographic data, stiffness and angular displacement between the shaft and lunate facet were determined. Stiffness in neutral position (N/mm) without/with dorsal plating was on average 164.3/166, 158.5/222.5 and 181.5/207.6 in groups 1–3. It increased significantly after supplementary dorsal plating in groups 2 and 3. Predominantly, from biomechanical perspective supplemental dorsal locked plating increases fixation stability of unstable distal radius fractures after volar locked plating. However, its effect depends on the fracture pattern at the distal radius

Distal radius fractures are the most common upper extremity injury, and are increasingly being treated surgically with pre-contoured volar-locking plates. These plates are favored for their low-profile template while allowing for rigid anatomic fixation of distal radius fractures. The geometry of the distal radius is extremely complex, and little evidence within the medical literature suggests that current implant designs are anatomically accurate. The main objective of this study is to determine if anatomic alignment of the distal radii corresponds accurately with modern volar-locking plate designs. Additionally, this study will examine sex-linked differences in morphology of the distal radius. Segmented CT models of ten female cadaver (mean age, 88.7 ± 4.57 years, range, 82 – 97) arms, and ten male cadaver (mean age, 86 ± 3.59 years, range, 81 – 91) arms were created. Micro CT models were obtained for the DePuy Synthes 2.4mm Extra-articular (EA) Volar Distal Radius Plate (4-hole and 5-hole head), and 2.4mm LCP Volar Column (VC) Distal Radius Plate (8-hole and 9-hole head). Plates were placed onto the distal radii models in a 3D visualization software by a fellowship-trained orthopaedic hand surgeon. The percent contact, volar cortical angle (VCA), border and overlap of the watershed line (WSL) were measured. Both sexes showed an increase in the average VCA measure from medial to lateral columns which was statistically significant. Female VCA ranged from 28 – 36 degrees, and 38 – 45 degrees for males. WSL overlap ranged from 0 – 34.7629% for all specimens without any statistical significance. The average border distance for females was 2.58571 mm, compared to 3.52411 mm for males, with EA plates having a larger border than VC plates. The border distances had statistically significant differences between the plate types, and was approaching significance between sexes. Lastly, a maximum percent contact of 21.966 % was observed in specimen F4 at a 0.3 mm threshold. No statistical significance between plate or sex populations was observed. This study investigated the incoherency between the volar cortical angle of the distal radius, and the pre-contoured angle of volar locking plates. It was hypothesized that if the VCA measures between plate and bone were unequal then there would be an increase in watershed line overlap, and decrease in percent contact between the surfaces. Our results agreed with literature, indicating that the VCA of bone was larger than that of the EA and VC pre-contoured plates examined in this study. With distal radius fracture incidences and prevalence on the rise for elderly female patients, it is a necessity that volar locking plates be re-designed to factor in anatomical features of individual patients with a particular focus on sex differences. New designs should focus on providing smaller head sizes that are more accurately tailored to the natural contours of the volar distal radius. It is recommended that future studies incorporate expertise from multiple surgeons to diversify and further understand plate placement strategies

Distal radial volar locking plating systems (DRVLP) are increasingly used for complex fractures of the distal radius. There have been limited studies on volar locking plating systems focusing on functional outcome and complications data. The aim of this study is to assess whether the surgeon can predict which fractures will have a good or poor outcome in terms of clinical, radiological and functional outcome assessment. Patients who sustained a distal radial fracture managed with a radial volar locking plate were identified from hospital audit data systems. Data was collected on all patients from patient notes including radiographs performed pre- and post-operatively and functional scores using the Patient Rated Wrist Evaluation score (PRWE). The study was approved by the Barwon Health Research and Ethics Advisory Committee. In total, there were 153 patients (105 female, 48 male) from all 11 surgeons in the unit. Patients ranged in age from 17 to 91 years, average age of 53.7 years at time of injury (IQR 41-70yr). A quarter had concomitant other injuries, and 60% had type C1-C3 fractures. Most of the patients (n = 147) had the AO Synthes DRVLP, six patients had other volar locking plate systems. Twenty-seven percent of patients (n = 42) had exogenous bone graft insertion for more unstable fracture patterns. The major complication rate was 12% (18/153) with 17 cases requiring further surgery. Post-operative radiographs demonstrated no increase in ulnar variance (median 0.0mm IQR 2.0 to1.0 mm) but an increase in radial inclination by 5 deg (IQR 0-12 deg), radial length by 3.5 mm (IQR 1.0-6.3 mm) and radial tilt by 17 deg (IQR 3-32 deg) (volar angulation) compared to pre-operative radiographs, which was statistically significant (all p<0.001). Ninety percent of patients returned a PRWE form with an average follow-up of 1.16 years (IQR 0.46-2.16yr). Median score for those aged less than 50 years was 14.00 (IQR 6.00-41.50) and did not differ from those greater than 50 years (median 16.00 IQR 4.50-36.00) (p = 1.00). PRWE score across groups categorised by classification of fracture showed large variance within each category and were not significantly different: Class A median 8.00 (IQR 3.50-26.25), Class B 13.00 (IQR 6.75-34.00) and Class C 17 (IQR 5.00-38.50) (p = 0.65). The majority of patients were female and had a type C fracture. Post-operative x-rays displayed an increase in radial inclination, length and tilt, and restoration of radial antatomy. PRWE scores were not different across age groups or classification of the fracture. This demonstrates that predictable outcomes can be achieved with volar locking plates despite fracture complexity if attention is paid to anatomical restoration of the radius, and in more unstable patterns with void support using injectable graft. Quadratus can act as an effective barrier to prominent hardware and superficial infection. Supination range may be reduced by this approach due to a tight repair, though a palmar DRUJ capsule contracture may also be an explanation

Distal radius fractures are very common and they often require surgical intervention to prevent long-term complications. We noticed that several patients were being managed non-operatively for prolonged periods of time, when ultimately surgical fixation was inevitable. Delayed fixation of these injuries results in prolonged immobilisation, repeat fracture clinic attendances, callous formation, poor soft tissues, stiffness and union. Our aim was to analyse the time to fixation of distal radius fractures at our hospital using a standard volar locking plate. Between December 2010 and September 2011, our study population included all patients who underwent surgical fixation for a distal radius fracture at Royal Derby Hospital. All fractures were fixed using a volar locking plate. Data collected included date of injury, fracture clinic attendances, date listed for surgery and date of surgery. There were 100 patients who underwent surgical fixation, with a mean age of 63.6 years (17 to 91). The mean date from injury to fixation was 7.7 days (range 0 to 23). 82% of fractures were operated on within 14 days, and 98% were fixed within 21 days. We accept that our study does have some limitations; this includes patients who are unwilling to accept surgery at their initial consultation. Distal radius fractures have a strong tendency to revert back to their original configuration; hence we suggest that a decision to operate should ideally be made at the one-week fracture clinic appointment. This avoids the difficulties and complications associated with delayed surgical intervention. Stability, displacement, reduction and patient factors should all be taken into account

Despite the variety of implants or techniques that exist to treat displaced distal radial fractures, the majority fail to provide sufficient stability to permit early functional recovery. However, locking plates have the advantage over other implants in that locking screws add considerably to the overall stability. The aim of this study was to assess the functional outcome of patients with displaced distal radial fractures treated with a volar distal radial locking plate (Synthes). During a two year period, details of 98 patients admitted to our unit with inherently unstable dorsally displaced distal radial fractures treated with volar locking plates were collected prospectively. For the purpose of this analysis, only those patients (55) with unilateral fracture, able to attend the study clinic at 6 months post-injury were considered. Patients were immobilised in wool and crepe for a 2 week period. The group consisted of 15 males and 40 females with an average age of 54 (28 to 83). At 6 months, patients' perceived functional recovery averaged 80%. Objective assessment was considered in relation to the uninjured side: grip strength 73%; pinch strength 83%; palmarflexion 77%, dorsiflexion 80%; radial deviation 74%; ulnar deviation 74%; pronation 93%, and supination 92%. Seven patients complained of symptoms relating to prominent metalwork. Good/excellent early subjective and objective functional recovery was made following open reduction and internal fixation using volar locking plates of dorsally displaced distal radial fractures. We suggest that objective assessment of grip strength and dorsiflexion can be used as a measure of patient perception of function

Distal radius fracture is one of the most common fractures in older women (∼70,000 cases annually in Canada). Treatment of this fracture has been shifting toward surgery (mainly volar locking plate (VLP) technology), which significantly enhances surgeon's ability to maintain correction. However, current surgical outcomes are far from perfect. There is a need for an implant which maintains the corrected position (reduction), minimizes soft tissue disruption, and is technically easy to perform. A novel internal, composite-based implant was designed to achieve these ends. It is unclear, however, whether this novel implant offers similar fracture fixation as the VLP. As such, the objective of this research was to evaluate the fracture stability (assessed by calculating change in fracture length) of the novel implant and VLP under cyclic fatigue loading. Specimens: Seven radius specimens derived from older female cadavers (mean = 82.3 years, SD = 11.3 years) were used for the experiment. Preparation: A standardized dorsal wedge was removed from the cortex. The distance from the proximal and distal transverse osteotomies was 10 mm and was positioned 20 mm proximal to the tip of the radial styloid. The osteotomy removed all load-bearing capabilities of bone, equivalent to a worst-case-scenario for DRF fixation. Simulated Loading: The proximal end of the radii was potted (fixed) and positioned in a material testing system. To mimic natural loading conditions, hands were cycled between −30°/30° flexion/extension, at 0.5 Hz, for 2000 cycles, while tension load was applied to the tendons (25-N constant force per tendon, 100-N in total). Mechanical testing outcomes: A position tracking sensor used to measure change in fracture length. This change, as a function of number of cycles, was used to assess implant resistance to fatigue loading. Statistical Analysis: A paired student t-test was used to compare the change in fracture length. Level of significance was determined as 5% (p < 0.05). Changes in fracture fracture-length for both the novel implant and plate is shown in Table 1. The paired t-test indicated significant differences between the two groups in terms of change in fracture length (p = 0.026). The outcome of the novel implant ranged from very stable (change in fracture-length = 0.01 mm) to highly un-stable (2.88 mm). We believe the reason for this variance, at least in part, originates from the surgical procedures. Presumably, given that one very strong stabilization (0.01 mm) and one acceptable stabilization (0.37 mm) was obtained, future research directed towards surgical procedures may improve fracture stability. For any figures or tables, please contact authors directly

Distal radius fractures are the most common osteoporotic fractures among women. The treatment of these fractures has been shifting from a traditional non-operative approach to surgery, using volar locking plate (VLP) technology. Surgery, however, is not without risk, complications including failure to restore an anatomic reduction, fracture re-displacement, and tendon rupture. The VLP implant is also marked by bone loss due to stress-shielding related to its high stiffness relative to adjacent bone. Recently, a novel internal, composite-based implant, with a stiffness less than the VLP, was designed to eradicate the shortcomings associated with the VLP implant. It is unclear, however, what effect this less-stiff implant will have upon adjacent bone density distributions long-term. The objective of this study was to evaluate the long-term effects of the two implants (the novel surgical implant and the gold-standard VLP) by using subject-specific finite element (FE) models integrated with an adaptive bone formation/resorption algorithm. Specimen: One fresh-frozen human forearm specimen (female, age = 84 years old) was imaged using CT and was used to create a subject-specific FE model of the radius. Finite element modeling: In order to simulate a clinically relevant (unstable) fracture of the distal radius, a wedge of bone was removed from the model, which was approximately 10 mm wide and centered 20 mm proximal to the tip of the radial styloid. Bone remodeling algorithm: A strain-energy density (SED) based bone remodeling theory was used to account for bone remodeling. With this approach, bone density decreased linearly when SED per bone density was less than 67.5 µJ/g and increased when it was more than 232.5 µJ/g. When it was in the lazy zone (67.5 to 232.5 µJ/g), no changes in density occurred. Boundary conditions: A 180 N quasi-static force representing the scaphoid, and a 120 N quasi-static force representing the lunate was applied to the radius. The midshaft of the radius was constrained. FE outcomes: To examine the effects of stress shielding associated with each implant, the long-term changes of bone density within proximal transverse cross-sections of radius were inspected. The regional density analysis focused on three transverse cross-sections. The transverse cross-sections were positioned proximal to the subchondral plate, and were distanced 50 (cross-section A), 57 (cross-section B), and 64 mm (cross-section C) from the subchondral endplate. For both implants in all three cross-sections, cortical bone was reserved completely at the volar side. On the dorsal side, the cortical bone was completely resorbed in the VLP model. In all cross-sections, the averaged resultant density was higher for the “novel implant”. The difference ranged from 33% (cross-section A) to 36% (cross-section C) in favor of the “novel implant”. On average, the density values of the novel implant were 34% higher in transverse cross-sections (A, B, and C). This study showed that the novel implant offered higher density distributions compared to the VLP, which suggests that the novel implant may be superior to the VLP in terms of avoiding stress shielding

Distal radius fractures are the most common upper extremity fracture. The incidence is significantly higher in elderly females with osteoporotic bone. When surgery is indicated, volar locking plates (VLPs) allow for rigid fixation particularly in comminuted fractures with poor bone quality. Although numerous studies have shown the importance of plate placement to avoid soft tissue complications associated with volar plate fixation, there has been little evidence on the anatomic fit of current VLPs. Moreover, the effect of gender differences in distal radius morphology on anatomic fitting of VLPs has not been studied. The aim of this study was to evaluate the gender difference in distal radius morphology and the accuracy of the fit of a current VLP to CT-based distal radius models. Segmented CT models of ten female (mean age, 89 ± 5 years), and ten male (mean age, 86 ± 4 years) cadaveric wrists were obtained. Micro-CT models of the DePuy-Synthes 4-hole extra-articular (EA) and 8-hole volar column (VC) distal radius VLPs were created. A 3D visualization software was used to simulate appropriate plate placement on to the distal radius models by a fellowship-trained hand surgeon. Volar cortical angles (VCA) of the medial, middle and lateral portion of the distal radius were measured and compared between genders. The accuracy of the fit of the two VLP designs were quantified using the percentage of the watershed line (WSL) overlapped by the plate (WSL overlap), the distance between the WSL and the most distal aspect of the posterior plate (prominence distance) and the percentage of contact between the plate and bone. There were statistically significant gender differences in medial, middle and lateral VCAs (p=.003 medial, p=.0001 middle, p=.002 lateral). VCA ranged from 28° to 36° in females and from 38° to 45° in males. The WSL overlap did not show statistically significant gender differences (male: 5.9%, female: 13.6%, p=.174). However, the difference in prominence distance between different genders approached statistical significance (male: 3.5mm, female: 2.6mm, p=.087). Contact mapping between the plate and bone did not demonstrate a perfect contact in any of our specimens. Thus, contact measurements were categorized into 0.1mm, 0.2mm, and 0.3mm threshold contacts. There were no statistically significant gender differences in any of the threshold categories (0.1mm: p=.84, 0.2mm: p=.97, 0.3mm: p=.99). Our results confirm that there are gender differences in distal radius morphology. Current plate designs incorporate a VCA of 25° which does not match the native VCA of the distal radius in males or females. Although the difference in prominence distance approached statistical significance, there were no statistically significant gender differences in the WSL overlap or the contact threshold values. This lack of statistical significance may be related to the small sample size. This study proposes novel methods of assessing the anatomic fit of current VLPs in a 3D CT-based model that may be used in future studies with a larger sample size. Moreover, this study demonstrated the importance of considering gender differences in distal radius morphology in the design of future generations of implants

Aims of study. To assess and compare the functional, radiological and cosmetic results as well as patient satisfaction in patients treated with the IMN Device Vs Volar Locking Plate. Method. All patients who presented to our institution with extra articular distal radius fractures and met the inclusion criteria were invited to take part in the study. The patients were randomly allocated to two groups, those who underwent intramedullary (IMN) distal radius fixation using the Sanoma Wrx Distal radius nail and those who underwent fixation using a volar locking plate. The patients were then followed up at 2 weeks, 6 weeks, 3 months, 6 months and 1 year. The radiological parameters, ie radial height, inclination and tilt were compared as well as the functional outcomes by means of DASH score. The range of motion of the wrist was compared as well as the scar size. Complications were reviewed. Results. We present our early results. Currently we have included 9 patients in the IMN group and 7 patients in the volar plate group with follow-ups longer than 3 months. Results show smaller scars (2.5 vs 6.7cm), comparable flexion and extension (40 vs 40 and 45 vs 40), slight improvements in pronation and supination (80 vs 75 and 85 vs 80) in the IMN compared to the volar plate. Radial and ulnar deviation is comparable. The radiological parameters showed slight improvements in the radial height (2.5 vs 2.2 mm), inclination (3.6 vs 3.2 degrees) and tilt 13,7 vs 12 degrees) with the IMN. Dash scores will be compared at 6 months. Conclusion. Intra medullary nailing of the distal radius seems to compare to volar plating in terms of radiological parameters and rotational stability but has the added benefit of early range of motion, minimal invasive technique, less post op pain and less complications such as tendon irritation. NO DISCLOSURES

Aim. With the current wave of enthusiasm for internal fixation with volar locking plates in the treatment of distal radial fractures, radiology of the wrist needs review. With current standardised x-rays of the wrist there is often an appearance of intra-articular screws. This is on account of the objective of getting very distal subchondral fixation and fixation into the radial styloid. As a consequence, due to the volar tilt and radial inclination of the ‘anatomic’ wrist, fixation is often perceived and reported to be intra-articular. It is proposed in this study that ‘standard’ wrist x-rays post-internal fixation be taken with 20° elbow flexion on the lateral view to counteract radial inclination. The postero-anterior view should be angled 10° to view the joint without the effect of normal radial tilt. Method and Materials. 30 consecutive wrists treated by fixed angled volar fixation were analysed. In each case standard x-rays and the proposed ‘20, 10’ radiographs were obtained. The ‘20, 10’ x-rays were taken with a custom-made set of bolsters set at 20° and 10° for the Lateral and PA views. Each set of x-rays (a standard PA and lateral and the so called ‘20, 10’ proposed radiographs) were commented on by 2 Radiologists and 2 Orthopaedic Surgeons. Results. It would appear that in both the Radiologists' and Orthopaedic surgeons' reports there was a higher degree of confidence in reporting on the 20, 10 views than on the standard views. In just over 50% of cases standard views had the appearance of intra-articular fixation while this perception was disproven with the newly proposed 20, 10 views. The correlation between Radiologist and Orthopaedic Surgeon reports was almost 100%. Conclusion. With the current trend to volar wrist fixation we should adapt our radiology protocols. We propose 20, 10 angled x-rays as standard for post-operative wrist radiology

Introduction. Getting the distal locking screw lengths right in volar locking plate fixation of distal radius is crucial. Long screws can lead to extensor tendon ruptures whereas short screws can lead to failure of fixation, especially if there is dorsal comminution of the fracture. The aim of our study was to determine the distal radius anatomy in relation to sagittal lengths and distance between dorsal bone edge and extensor tendons based on MRI scan. Method. One hundred consecutive MRI scans of wrist were reviewed by two of the authors on two occasions. All MRI scans were performed for different wrist pathologies except distal radius fractures or tumours. An axial image, two cuts proximal to the last visible articular surface, was selected. Sagittal length at 5 different widths, maximum volar width, radial overhang over distal radio-ulnar joint and the distance between dorsal bone edge and extensor tendons were measured. Results. A total of 120 MRI scans were included of which 74 were women and 46 were men. Mean volar width was 32mm and longest sagittal length was 22 mm (at Lister's tubercle). Length radial to Lister's tubercle was the shortest (17mm) and ulnar sides were 21mm and 29mm. Male measurements were mean 3mm longer than females. Mean radial overhang over DRUJ was 4mm. Distance from bone to tendons was within 2mm of dorsal radius edge. Conclusion. The study provides a reference guide to average screw lengths at different widths of distal radius in males and females. EPL tendon is closest to bone although all the extensor tendons are within 2mm of bone edge and carry a risk of injury from drill and screw placement. DRUJ is also at risk of injury if screws are placed within 4mm of ulnar edge of distal radius

Background. Angular stable volar locking plates have become increasingly popular for more comminuted fractures of the distal radius. Newer designs of plates have been thicker in profile and incorporate more options for distal fragment fixation. Although they have been shown to be successful at maintaining reduction to allow early mobilisation the main drawback is from screw cut-out. In our practice we have noticed that the newer style of plates that offer more rigid fixation has lead to more instances of screw cut-out. We aimed to quantify the minimum number of locking pegs and or screws need to maintain the operative reduction. Method. We retrospectively looked at a series of 46 patients that had undergone volar plating. We assessed the fracture severity on pre-operative films (according to AO classification) and compared radiographic parameters (volar tilt VT, radial inclination RI and radial height RH) on post-operative films. We calculated the amount of reduction lost from initial post operative x-rays to radiographs taken when union was confirmed. We compared this to the number of locking units used to fix the distal radius and also the configuration they were inserted, i.e. the number in the radial and middle columns. Results. The mean loss of reduction in all plates was 0.9mm of RH, 2.2degs of RI and 2.8degs of VT. There was no difference in mean ‘reduction lost’ between plates that had a total of 2 or 3 locking units (RH 1mm and 1mm, RI 2.0deg and 2.7deg and VT 2.9deg and 3.2 deg respectively). This was also case when sub-analysing more severe OTA Type C fractures. Conclusion. Only one locking peg is needed under each column for adequate stability (i.e. a total of two distal locking units). Any more than this confers no additional benefit in maintaining reduction, ever in more severe fractures. The extra rigidity provided by more locking screws/pegs and also thicker plates: as provided by newer designs of plates, may make them more prone to cut out

BACKGROUND. In our institution we use the Winklestabile volar locking plate for operative fixation of distal radius fractures. This study aims to assess subjective and objective outcomes using this method of treatment. METHODS. A total of 21 patients who underwent ORIF of distal radius fractures with the Winklestable plate in 2005 with a minimum follow up of 12 months were assessed using the Patient Rated Wrist Evaluation (PRWE) questionnaire and the Disabilities of the Arm Shoulder and Hand (DASH) score. Range of wrist movement (ROM), grip strength and pinchgrip strength were assessed by comparison with the unaffected wrist. RESULTS. Mean age was 64.34yrs (median 65.74, interquartile range (IQR) 59.11 – 71.80). The mean time from presentation to surgery was 2.0 days (median 1.0, IQR 1.0 - 2.0). Radiological union was confirmed after a mean of 83.3 days (median 83.0, IQR 83.0 – 90.0). Twenty fractures followed low energy trauma and 19 were closed. Eleven fractures were extra-articular. None, minimal or mild PRWE scores were achieved in 18 (86%) patients for pain, 15 (71%) for specific functions and 19 (90%) for usual functions. Six patients scored zero on the DASH score (mean 17.0, median 4.0, IQR 0.0-23.0). There was no difference in grip strength (pounds) in two patients (mean 10.6, median 6.0, IQR 4.0-15.0) and no difference in pinchgrip strength in nine patients (mean 1.0, median 0.5, IQR 0.0-1.5). Sixteen patients (76%) reported no complications. Two patients required extra postoperative physiotherapy. One suffered extensor polis longus rupture. One reported generalised wrist pain. One reported difficulty pushing down with affected hand. One reported pain on movement. No patients required revision surgery. CONCLUSION. In our institution, we believe that ORIF for distal radius fractures using the Winklestabile distal radius locking plate achieves satisfactory subjective and objective results with an acceptable rate of complications

Background. The distal part of the radius is the most common localisation of fractures of the human body. Dislocated intraarticular fractures of the distal radius (FDR) are frequently treated by open reduction and internal fixation with a volar locking plate (VLP) under fluoroscopic guidance. Typically the locking screws are placed subchondral near the joint line to achieve maximum stability of the osteosynthesis. To avoid intraarticular screw placement an intraoperative virtual implant planning system (VIPS) as an application for mobile C-arms was established. The aim of the study was the validation of the implemented VIPS comparing the intraoperative planning with the actual placement of the screws. The study was conducted as a single-centre randomised controlled trial in a primary care institution. The hypothesis of the study was that there is conformity between the virtual implant position and the real implant placement. Patients/Material and Methods. 30 patients with FDR type A3, C1 and C2 according to the AO-classification were randomised in two treatment groups and allocated either in the conventional or in the VIPS group in which the patients underwent an intraoperative planning before screw placement. The randomisation was performed on the basis of a computer-generated code. After fracture reduction an initial diaphyseal fixation of the plate was done. Then the matching of the three-dimensional virtual plate with the image of the real plate in the fluoroscopy shots in two planes was performed automatically. The implant placement was planned intraoperatively in terms of orientation, angulation and length of the screws. After the placement of four or five locking screws the implant position was verified with an intraoperative three-dimensional mobile C-arm scan. The locking screws near the joint line were examined and compared in relation to the actual and the planned inclination angle, the azimuth angle which is determined analogue to a compass rose and the screw-tip distance. The planned and actual parameters of the locking screws were then statistically analysed applying the Shapiro-Wilk - and the Students t-test. Results. 15 patients with FDR were treated in the VIPS arm. In the VIPS group six fractures type A3 one type C1 and eight type C2 were included. The control group showed a similar fracture distribution with six type A3 and nine type C2 fractures. The discrepancy between the actual and the planned screw-tip distance was 2,24 ± 0,97 mm and did not differ significantly (p>0,05). The angle of the planned and actual screw placement also did not vary significantly (p>0,05). The difference of the actual to the planned azimut angle accounted for 18,69°± 29,84. The planned and real inclination of the screws differed by 1,66° ± 4,46. Conclusion. The analysis shows that the screws were almost placed as planned. Differences between actual and planned placement of the screws were observed but were not statistically significant. Therefore the hypothesis of the study can be accepted. We assume, that the precise planning of the screw placement in FDR with VIPS can be transported into the surgical treatment