INTRAOPERATIVE COMPUTED TOMOGRAPHY: AN ADVANCED APPROACH FOR VISUALIZATION OF FIXATION MATERIAL IN DISTAL RADIUS FRACTURES

ObjectivesTo compare intraoperative 3D fluoroscopy with a ceiling-mounted flat panel detector in plate osteosynthesis of distal radius fractures (AO/OTA 2R3C1.2) with volar locking plate systems to conventional 2D fluoroscopy for detection of insufficient fracture reduction, plate misplacement and protruding screws.MethodsUsing a common volar approach on 12 cadaver forearms, total intraarticular distal radius fractures were induced, manually reduced and internally fixated with a 2.4 distal radius locking compression plate. 2D (anterior-posterior and lateral) and 3D (rotational) fluoroscopic images were taken as well as computed tomographies. Fluoroscopic images, Cone Beam CT (CBCT), 360° rotating sequences (so called “Movies”) and CT scans were co-evaluated by a specialist orthopedic surgeon and a specialist radiologist regarding quality of fracture reduction, position of plate, position of the three distal locking screws and position of the three diaphyseal screws. In reference to gold standard CT, sensitivity and specifity were analyzed.Results“Movie” showed highest sensitivity for detection of insufficient fracture reduction (88%). Sensitivity for detection of incorrect position of plate was 100% for CBCT and 90% for “Movie.” For intraarticular position of screws, 2D fluoroscopy and CBCT showed highest sensitivity and specifity (100 and 91%, respectively). Regarding detection of only marginal intraarticular position of screws, sensitivity and specifity of 2D fluoroscopy reached 100% (CBCT: 100 and 83%). “Movie” showed highest sensitivity for detection of overlapping position of screws (100%). When it comes to specifity, CBCT achieved 100%. Regarding detection of only marginal overlapping position of screws, 2D fluoroscopy and “Movie” showed highest sensitivity (100%). CBCT achieved highest specifity (100%).ConclusionAs for assessment of quality of fracture reduction and detection of incorrect position of plate as well as overlapping position of the three diaphyseal screws CBCT and “Movie” are comparable to CT – especially when combined. Particularly sensitivity is high compared to standard 2D fluoroscopy.

Background/Objectives: Dorsal screw protrusion or intra-articular screw penetration at the distal radius can cause extensor tendon injuries or articular surface damage. Despite the use of various views, the detection of screw misplacement remains limited in 2D fluoroscopy. This study compares the sensitivity of 2D and 3D fluoroscopy for detecting screw misplacement at the distal radius. Methods: Volar locking plates were placed in six cadaveric forearms, and dorsal or intra-articular screw misplacement was induced. For each screw position, images were acquired by 2D and 3D fluoroscopy and assessed by three blinded observers. Sensitivity and specificity, inter-rater agreement, and observer confidence were evaluated. The dose area product (DAP) was measured separately for 2D and 3D fluoroscopy. Results: Three-dimensional fluoroscopy showed higher sensitivities for detecting dorsal (97.22%) and intra-articular (95.83%) screw misplacements than two-dimensional fluoroscopy. In 2D fluoroscopy, sensitivity for detecting dorsal screw protrusions improved from 63.89 to 75.00-77.78% with the inclusion of tangential views. For intra-articular penetrations, sensitivity in 2D fluoroscopy increased from 79.17 to 83.33% with the addition of oblique views. Observer confidence was higher in 3D fluoroscopy. DAP was significantly higher in 3D (42.4 ± 0.4 cGycm2) compared to 2D fluoroscopy (14.2 ± 3.7 cGycm2) (p < 0.0001). Conclusions: Compared to 2D fluoroscopy, 3D fluoroscopy improves the detection of screw misplacement at the distal radius. However, its routine use is constrained by increased radiation exposure and limited availability. If 3D fluoroscopy is not accessible, the addition of dorsal tangential and oblique views may improve the sensitivity of 2D fluoroscopy.

The utility of routine x-rays after the osteosynthesis of distal radius fractures and ankle fractures is questionable. We performed a trial to determine whether such x-rays are justified in patients who have undergone standardized imaging with C-arm fluoroscopy during surgery. Patients requiring surgery for a distal radius fracture or an ankle fracture were candidates for inclusion in this prospective, randomized, controlled, non-blinded trial. Standardized intraoperative images were obtained with C-arm fluoroscopy and stored at the end of the operation. The next day, patients in the control group underwent imaging with a standard postoperative x-ray, while those in the intervention group did not. The primary endpoint was a change in the treatment plan, defined as additional imaging or a second operation. The secondary endpoints included the range of motion, pain as rated on the Visual Analog Scale, and a functional outcome analysis (PRWE/FAOS). 316 patients were included in the trial (163 in the control group, 153 in the intervention group), of whom 202 (64%) had radius fractures and 114 (36%) had ankle fractures. The treatment plan changed in twelve patients (3.8%; four in the control group and eight in the intervention group), seven of whom (2.2%; three in the control group and four in the intervention group) underwent a second operation. The frequency of changes in the treatment plan and of reoperations was comparable in the two groups (p = 0.36). On follow-up at six weeks and one year, the results with respect to functional outcomes and pain were comparable. In this trial, routine postoperative x-rays after the osteosynthesis of distal radial fractures and ankle fractures did not improve the care of patients who had undergone standardized intraoperative imaging.

BackgroundRecently, computerized virtual surgery planning has been increasingly applied in various orthopedic procedures. In this study, we developed an image fusion system for 3D preoperative planning and fluoroscopy for the osteosynthesis. To assess the utility of image fusion system, we evaluated the reproducibility of preoperative planning in the osteosynthesis of distal radius fractures with using the image fusion system, and compared with the reproducibility of the patients without using the image fusion system.MethodsForty-two wrists of 42 distal radius fracture patients who underwent osteosynthesis using volar locking plates were evaluated. The patients were divided into two groups. Image fusion group utilized three-dimensional (3D) preoperative planning and image fusion system. Control group utilized only 3D preoperative planning. In both groups, 3D preoperative planning was performed in order to determine reduction, placement, and choice of implants. In the image fusion group, the outline of planned image was displayed on a monitor overlapping with fluoroscopy images during surgery. Reductions were evaluated by volar tilt and radial inclination of 3D images. Plate positions were evaluated with distance to joint surface, plate center axis position, and inclination relative to the radius axis. Screw choices were recorded for the plan and actual choices for each screw hole. Differences in the parameters between pre- and postoperative images were evaluated. Differences in reduction shape, plate positions, and screw choices were compared between groups.ResultsThe differences in the distance from plate to joint surface were significantly smaller in the image fusion group compared to the control group (P < 0.01). The differences in the distal screw choices were significantly smaller in the image fusion group compared to the control group (P < 0.01).ConclusionsThe image fusion system was useful to reproduce the planned plate position and distal screw choices in the osteosynthesis of distal radius fractures.Trial registrationClinicalTrials.gov, NCT03764501

BackgroundThree-dimensional preoperative planning was applied for the osteosynthesis of distal radius fractures. The objective of this study was to evaluate the reproducibility of three-dimensional preoperative planning for the osteosynthesis of distal radius fractures with three-dimensional reference points.MethodsSixty-three wrists of 63 distal radius fracture patients who underwent osteosynthesis with three-dimensional preoperative planning were evaluated. After taking preoperative CT scans of the injured wrists, 3D images of the distal radius were created. Fracture reduction, implants choices, and placements simulation were performed based on the 3D images. One month after the surgery, postoperative CT images were taken. The reproducibility was evaluated with preoperative plan and postoperative 3D images. The images were compared with the three-dimensional coordinates of radial styloid process, volar and dorsal edges of sigmoid notch, and the barycentric coordinates of the three reference points. The reproducibility of the preoperative plan was evaluated by the distance of the coordinates between the plan and postoperative images for the reference points. The reproducibility of radial inclination and volar tilt on three-dimensional images were evaluated by intra-class correlation coefficient (ICC).ResultsThe distances between the preoperative plan and the postoperative reduction for each reference point were (1) 2.1±1.3 mm, (2) 1.9±1.2 mm, and (3) 1.9±1.2 mm, respectively. The distance between the preoperative plan and postoperative reduction for the barycentric coordinate was 1.3±0.8 mm. ICCs were 0.54 and 0.54 for the volar tilt and radial inclination, respectively (P<0.01).ConclusionsThree-dimensional preoperative planning for the osteosynthesis of distal radius fracture was reproducible with an error of about 2 mm for each reference point and the correlations of reduction shapes were moderate. The analysis method and reference points may be helpful to understand the accuracy of reductions for the three-dimensional preoperative planning in the osteosynthesis of distal radius fractures.Trial registrationRegistered as NCT02909647 at ClinicalTrials.gov

The Dorsal Horizon View: Detecting Screw Protrusion at the Distal Radius

Background: To assess the usefulness of three-dimensional (3D) digital pre-operative planning, we compared the radiographic parameters of the distal radius from 3D planning and conventional planning after osteosynthesis of distal radius fractures. We hypothesized that the use of 3D digital planning may improve radiographic outcomes for reduction and decrease the risk of correction loss. Methods: Sixty wrists of 60 distal radius fracture patients were randomly divided into two groups according to the order of hospital visits. Thirty wrists were treated with 3D preoperative planning as the plan group. Another thirty wrists were treated with conventional preoperative planning as the control group. Both groups were treated with volar locking plates. In the plan group, 3D digital preoperative planning and a surgical simulation were performed in order to determine the reduction and placement of the implants in addition to the plate/screw size prior to surgery. In the control group, conventional preoperative planning was performed. Ulnar variance, volar tilt, and radial inclination were measured at one week, three and six months after surgery. Difference of the measurement of radiographic parameters between operated and healthy side wrists were compared between plan and control groups at one week after surgery. Loss of corrections for radiographic parameters were compared between plan and control groups. Results: The differences between the operated and healthy side wrists were significantly smaller in the plan group compared to the control group for the volar tilt and radial inclination (p < 0.05).The loss of corrections for ulnar variance and volar tilt were significantly smaller in the plan group compared to the control group at six months after surgery (p < 0.05). Conclusions: 3D preoperative planning offers better reduction accuracy and reduces correction loss in the osteosynthesis of distal radius fractures.

The purpose of this study was to analyze the practicability and benefit of intraoperative C-arm computed tomography (CT) imaging in volar plate osteosynthesis of unstable distal radius fractures. During a 1 year period, intraoperative three dimensional (3D) imaging with the ARCADIS Orbic 3D was performed in addition to standard fluoroscopy in 51 cases. The volar angular stable plate oesteosyntheses were analyzed intraoperatively and, if necessary, improved immediately. The duration of the scan and radiation exposure dose were measured. On average, performance of the scan and analysis of the CT dataset took 6.7 minutes. In 31.3% of the surgeries a misplacement of screws was detected and correction was done immediately. C-arm CT imaging can easily be integrated in the normal course of surgery. As a complement to the standard 2D-fluoroscopy, the C-arm CT is a useful tool to evaluate the quality of osteosynthesis.

A three-dimensional (3D) digital pre-operative planning system for the osteosynthesis of distal radius fracture was developed. The objective of this study was to evaluate screw choices for three-dimensional (3D) digital pre-operative planning of osteosynthesis of distal radius fractures and to compare with the screw choices for the conventional method. Distal radius fracture patients who underwent osteosynthesis using volar locking plates were evaluated. Thirty wrists in the plan group utilized 3D preoperative planning, and nineteen wrists in the control group utilized conventional preoperative assessment. In the plan group, the 3D preoperative planning was performed prior to surgery. The reduction was simulated with 3D image, and the implant choice/placement also simulated on the 3D image. In the control group, standard preoperative planning was performed using posterior-anterior and lateral view radiographs, and CT scan. After the planning, osteosynthesis was performed. During the surgery, the operator performed the reduction and the placement of the plate while comparing images between the pre-operative plan and fluoroscopy. The distal screw lengths and the anteroposterior diameter of the radius along the axis of the distal screws were measured. The ratios of the screw length and radius diameter were evaluated. The screw/radius ratios within the range of 0.75-1.00 were considered appropriate. The screw choices less than 0.75, or greater than 1.00 were considered inappropriate. The rate of appropriate screw choices were compared between plan and control groups. The results of appropriate screw choices were 86.1% and 74.8% in the plan group and the control group, respectively. The inappropriate screw choices were 14.0% and 25.2% in the plan group and the control group, respectively. The three-dimensional planning significantly increased appropriate screw choices compared to the conventional planning (p < 0.05). Three-dimensional digital preoperative planning is useful for the optimization of screw lengths in osteosynthesis of distal radius fractures.

Background The aim of this study was to determine whether the duration of the approach (PII) and closure (PV) phases for minimally invasive plate osteosynthesis (MIPO) of distal radius fractures varied according to the surgeon's level of expertise. The main hypothesis was that the PII or PV duration was inversely proportional to the level of expertise. Materials and Methods The method measured the duration of PII and PV for 50 videos of MIPO operated by one surgeon with level 3E expertise, three with level 4E, and one with level 5E. The videos were viewed to identify any technical errors. Results The average PII duration was 3 minutes 8 seconds for level 5E, 4 minutes 7 seconds for 4E, and 6 minutes 19 seconds for 3E. Average PV duration was 2 minutes 12 seconds for level 5E, 2 minutes 36 seconds for 4E, and 2 minutes 41 seconds for 3E. The average duration of PII + PV was 5 minutes 20 seconds for level 5E, 6 minutes 37 seconds for 4E, and 9 minutes for 3E. These findings indicate that both PII and PV duration was the longest in the level 3E surgeons' practice. Six technical errors were identified for levels 3E and 4E during PII (hemostasis control, multiple incisions, instrument handling, improper use of the fluoroscope, time-outs) and PV (intradermal reattachment). Clinical Relevance The main hypothesis was verified since the duration of PII or PV was inversely proportional to the surgeon's level of expertise. This study identified technical errors in hand surgery practices of new surgeons. By early identification and correcting these minor errors, it would be possible to speed up the learning curve. We recommend surgical videos to be systematically recorded and analyzed to improve hand surgery practices. Type of Study/Level of Evidence Therapeutic/Level IIIa.

Purpose to evaluate and to compare radiological and functional outcomes of the volar locking plate fixation using pronator-sparing approach and K-wire fixation of distal radius fractures. Materials and Methods. We retrospectively analyzed 41 patients with distal radius fractures (27 female and 14 male) treated in the period from 2016 to 2020 using minimally invasive osteosynthesis via pronator-sparing approach. The mean age was 51 years (31-74 years). The control group consists of 37 patients (19 female and 18 male, mean age 61 years (29-76 years)), who underwent minimally invasive percutaneous K-wire fixation of distal radius fractures during the same period of time. Comparative analysis of radiographic and functional outcomes in both groups of minimally invasive osteosynthesis of distal radius fractures was carried out in the period from 1 to 6 months after the surgery. Results. Primary union of distal radius fractures was confirmed in X-rays in all patients within 6 weeks after the surgery. There were no complications in patients treated by pronator-sparing volar locking plate fixation, whereas in K-wire group we had 6 patients with complications: 4 cases (11%) superficial infection around K-wires and 2 cases (5,4%) intraoperative damage of sensitive branch of radial nerve. There were statistically significant differences in radiographic results (volar tilt, radial inclination, and radial height) between two groups: they all were better in patients treated by pronator-sparing volar locking plate fixation during the whole follow-up period (р0,01). Minimally invasive volar locking plate fixation via pronator-sparing approach also provided significantly better grip strength and range of wrist motion and forearm rotation in the early 6-month postoperative period, compared with percutaneous K-wire fixation (р0,001). Conclusion. Our study demonstrates that both techniques of minimally invasive osteosynthesis of distal radius fractures are effective and relatively safe methods of surgical treatment, but volar plating via pronator-sparing approach leads to a better reconstruction of the distal radius and better functional outcomes compared to percutaneous K-wiring.

Distal radius fractures are the most commonly reported fractures in adults. Treatment has changed in recent years to open reduction and palmar plate fixation. Penetration of the dorsal screw, however, is a well-known complication. Intraoperative anteroposterior and lateral radiographs lack the exact assessment of dorsal screw length and intraoperative measurement is therefore very likely to be inaccurate in a comminuted dorsal radial cortex. Secondary extensor tendon ruptures are reported in up to 6% following palmar plate fixation of distal radius fracture. A prospective randomized trial was performed to assess the value of the dorsal horizon view. The hypothesis was that the traditional anteroposterior and lateral fluoroscopic views aided by an axial view of the dorsal part of the radius, named dorsal horizon view, could prevent dorsal screw penetration. A total of 40 patients, 6 male and 34 female, were included in the study. Standardized anteroposterior and lateral radiographs were performed intraoperatively in 18 patients (standard group = control group). In 22 patients, intraoperative axial fluoroscopic views (dorsal horizon view) were added to anteroposterior and lateral images (horizon group). Numbers of intraoperative screw changes due to the two different radiological examinations were analyzed as well as exact postoperative CT guided measurement of screw length. The total numbers of intraoperative screw changes were significantly higher in the horizon group. Forty-two screws were changed in 15 patients in the horizon group while only 8 screws were changed in 3 patients in the standard group. Postoperative computed tomography scans showed significantly lower total numbers of perforating screws in the horizon group with 11 screws in 22 patients compared to 20 screws in 18 patients in the standard group (p = 0.02). Based on the results of this study, the dorsal horizon view improves the assessment of the correct screw length and should routinely be used in palmar plate osteosynthesis of distal radius fractures. Since screw protrusion cannot be absolutely ruled out using the dorsal horizon view, monocortical drilling or screw downsizing is still mandatory. This clinical trial was not registered because it was a clinical examination without any experimental techniques.

BackgroundSymptomatic extensor tendon irritation is a frequent complication in volar plate osteosynthesis of distal radius fractures. It is typically caused by dorsal screw protrusion and overdrilling of the dorsal cortex. The use of self-drilling locking screws (SDLS) could overcome both causes. The practical applicability of SDLS depends on two prerequisites: (1) the feasibility of preoperative distal screw length determination, and (2) sufficient primary biomechanical stability of SDLS compared to standard locking screws (SLS).MethodsWe first assessed the feasibility of preoperative screw length determination (1): Distal radius width, depth and distal screw lengths were measured in 38 human radii. Correlations between distal radius width and depth were assessed, a cluster analysis (Ward’s method and squared Euclidean distance) for distal radius width conducted, and intra-cluster screw lengths analyzed (ANOVA). The biomechanical performance of SDLS (2) was assessed by comparison to SLS in a distal radius fracture model (AO-23 A3). 75 % distal screw length was chosen for both groups to simulate a worst-case scenario. Uniaxial compression tests were conducted to measure stiffness, elastic limit, maximum force and residual tilt. Statistics comprised of independent sample t-tests and a Bonferroni correction (p < 0.0125).Results(1) Distal radius width and depth showed a high correlation (R2 = 0.79; p < 0.001). Three distal radius width clusters could be identified: small <34 mm; medium 34–36.9 mm; large >36.9 mm. ANOVA and Tukey post-hoc analysis revealed significantly different volar-dorsal depths (p < 0.05) for nearly all screws. (2) To assess biomechanical stability nine specimens were tested each; no significant differences were found between the SDLS and SLS groups.ConclusionsThis feasibility study demonstrates that (1) distal radius width can be used as a predictor for distal screw length and (2) that SDLS provides mechanical stability equivalent to SLS. These results highlight the feasibility of applying SDLS screws in volar plate osteosynthesis at least in extraarticular fractures.

Major surgical approaches for volar plating of the distal radius include the standard flexor carpi radialis (FCR) approach, the extended FCR (eFCR) approach, and the extended FCR approach combined with radial-sided carpal tunnel release (eFCR+CTR). The purpose of this study was to determine which of these three surgical approaches offers the greatest exposure and visualization of the distal radius. Sequential dissections were performed on each of 30 fresh frozen below elbow cadaveric samples in order to simulate the three surgical approaches for distal radius volar plating, starting with the standard FCR approach, advancing to eFCR, and finishing with eFCR+CTR. Prior to the initial dissection of each cadaveric sample, radiographs were taken in order to calculate the total area of the distal radius. Then, following each sequential dissection, photographs were taken of each specimen and analyzed with an image measuring software in order to obtain the area of distal radius exposed. The percentage of total distal radius exposure was then calculated for each of the three surgical approaches. The eFCR+CTR approach offered the greatest average distal radius exposure at 87% of total distal radius visualized. The eFCR approach provided the next greatest exposure with an average of 73% visualized, followed by the standard FCR approach with an average of 61% visualized. The extended FCR approach with radial-sided carpal tunnel release is both safe and efficacious for osteosynthesis of distal radius fractures in the setting of concomitant carpal tunnel syndrome. This study demonstrates that an additional advantage of this approach includes improved surgical exposure and visualization of the distal radius. This surgical approach is a valuable addition to any upper extremity surgeon's armamentarium and should be considered when treating difficult distal radius fractures.

Reproducibility of three dimensional digital preoperative planning for the osteosynthesis of distal radius fractures.