Volar fixed-angle plating of distal radius extension fractures: influence of plate position on secondary loss of reduction--a biomechanic study in a cadaveric model

Intraoperative assessment of the dorso-ulnar fragment stability with stress fluoroscopy: An observational study

This study aims to investigate the effectiveness of intraoperative stress radiographs in evaluating the stability and fixation adequacy of the dorso-ulnar fragment (DUF) after volar plate application. Sixty-four patients who underwent open reduction and internal fixation due to comminuted distal radius fracture accompanied by DUF between May 2020 and February 2022 were reviewed retrospectively. Two groups were compared, with and without stress radiographs used in addition to routine fluoroscopic imaging during the surgical treatment of distal radius fractures. DUF sizes and fracture classifications were made according to preoperative computed tomography. Displacement of the DUF, dorsal cortex screw penetration, and the number of screws inserted into the DUF were evaluated on immediate postoperative CT scans and direct radiographs. DUF displacement at the patients' last follow-up was significantly higher in the control group (1.62 mm) than in the additional stress fluoroscopy applied group (0.53 mm). It was observed that the amount of displacement increased as the dorso-volar size of the DUF decreased. No significant difference was observed in dorsal cortex screw penetrations between the 2 groups. In the additional stress fluoroscopy applied group, stabilization rates with at least 1 screw over volar-locking plate for DUF were significantly higher (P < .001). Compared to the stress fluoroscopy group, the change in ulnar variance (P < .001) and volar tilt (P < .001) was significantly higher in the control group in the last follow-up radiography. No significant difference was observed between the implant removal rates of both groups. Evaluation of the stability of the DUF with stress radiographs after fixation is an effective method to reveal the need for additional fixation. Dorsal stress radiographs allow dynamic evaluation of fixation strength.

Volar fixed plating of distal radius fractures: optimizing plate position for enhanced clinical outcomes

BACKGROUND

The precise influence of plate position on clinical outcomes in the context of volar fixed-angle plating for distal radius fractures is not fully understood. This article aims to investigate the influence of plate position on clinical results, and functional outcomes in patients treated with volar fixed plating for distal radius fractures.

METHODS

A total of 58 patients with 64 distal radius fractures were included in the study. Patient demographics, fracture characteristics, surgical details, and radiographic data were collected. Post-operative AP and Lat views of all patients taken on the first day after surgery were evaluated. Volar Tilt, Radial Inclination and Radial Height measurements were used as reduction criteria. In the follow-up, the patients were called for their last control, flexion and extension angles of the wrist and Mayo Wrist Scores, the distance of the plate to the joint line and the angle between the plate and the radial shaft were measured and recorded.

RESULTS

A total of 64 distal radius fractures, with a mean age of 46.9 years, and the mean follow-up period 24.9 months were included in this study. There was a significant relationship between the Radial Inclination and Plate-Shaft Angle variables and the Mayo Wrist Score at a 99% confidence interval. Additionally, a relationship was observed between the Radial Height variable and the Mayo Score at a 90% confidence interval. A significant positive association was observed between radial inclination and achieving a Good-to-Excellent Mayo score (OR = 1.28, 95% CI [1.08-1.51], p = 0.004). Plate distance to joint line demonstrated a marginally significant positive association with a Good-to-Excellent Mayo score (OR = 1.31, 95% CI [0.97-1.77], p = 0.077). Univariate analysis revealed a significant negative association between plate-shaft angle and achieving a Good-to-Excellent Mayo score (OR = 0.71, 95% CI [0.52-0.99], p = 0.045). This negative association remained statistically significant in the multivariate analysis (p = 0.016).

CONCLUSION

Radial inclination, plate distance to joint line, and angle between plate and radius shaft were identified as significant factors associated with improved Mayo Wrist Scores.

Volar Locking Plating of Extra-articular Distal Radius Fracture: A Retrospective Clinical Study Comparing Locking Screws versus Smooth Locking Pegs

Background  Open reduction and internal fixation of distal radius fractures is one of the most common procedures performed in wrist surgery. The use of volar locking plate has gained increasing interest in the past decade. Epiphyseal fixation can be done either with locking screws or smooth locking pegs, with no evidence supporting the use of one rather than the other. Purpose  The aim of this study is to compare the stability of distal radius fixation by volar locking plate using locking screws or smooth locking pegs. Methods  Adult patients with A2-A3 AO fractures treated with a volar plate with locking screws only or smooth locking pegs only were retrospectively included. Radiographic assessment was performed to evaluate extra-articular parameters in the intraoperative postreduction and fixation period and after bony healing. Forty-seven distal radius fractures were included. Results  Twenty-four fractures had fixation with locking screws and 23 had fixation with smooth locking pegs. For both groups, all radiographic parameters measured showed a statistically significant difference between the intraoperative postreduction and fixation period and the remote postoperative period after union of the fracture ( p  < 0.05) attesting a slight loss of reduction. Nevertheless, there were no significant differences between the groups in radiographic extra-articular parameters. Conclusion  This clinical study shows that there is no difference in stability fixation between locking screws or smooth locking pegs in A2-A3 distal radius fractures. Clinical Relevance  The use of smooth locking pegs only for epiphyseal fixation appears to be safe in volar plating of A2-A3 distal radius fractures in adult patients and could be an alternative to locking screws. More clinical data are needed to confirm these results. Level of Evidence  Level III; retrospective comparative study.

Teardrop Alignment Changes After Volar Locking Plate Fixation of Distal Radius Fractures With Volar Ulnar Fragments

BACKGROUND

We assessed factors associated with change in radiographic teardrop angle following volar locking plate (VLP) fixation of volarly displaced intra-articular distal radius fractures with volar ulnar fragments (VUF) within the ICUC database. The primary outcome was change in radiographic alignment on follow-up imaging, defined as a change in teardrop angle from intra-operative fluoroscopy greater than 5°.

METHODS

Patients with distal radius fractures treated with a VLP within the ICUC database, an international collaborative and publicly available dataset, were identified. The primary outcome was volar rim loss of reduction on follow-up imaging, defined as a change in radiographic alignment from intra-operative fluoroscopy, teardrop angle less than 50°, or loss of normal radiocarpal alignment. Secondary outcomes were final range of motion (ROM) of the affected extremity. Radiographic Soong classification was used to grade plate position. Descriptive statistics were used to assess variables' distributions. A Random Forest supervised machine learning algorithm was used to classify variable importance for predicting the primary outcome. Traditional descriptive statistics were used to compare patient, fracture, and treatment characteristics with volar rim loss of reduction. Volar rim loss of reduction and final ROM in degrees and as compared with contralateral unaffected limb were also assessed.

RESULTS

Fifty patients with volarly displaced, intra-articular distal radius fractures treated with a VLP were identified. Six patients were observed to have a volar rim loss of reduction, but none required reoperation. Volar ulnar fragment size, Soong grade 0, and postfixation axial plate position in relation to the sigmoid notch were significantly associated (P < .05) with volar rim loss of reduction. All cases of volar rim loss of reduction occurred when VUF was 10.8 mm or less.

CONCLUSIONS

The size of the VUF was the most important variable for predicting volar rim loss of reduction followed by postfixation plate position in an axial position to the sigmoid notch and the number of volar fragments in the Random Forest machine learning algorithm. There were no significant differences in ROM between patients with volar ulnar escape and those without.

Is a Novel Fluoroscopic Intraoperative Reference System Superior to Conventional Management for Distal Radius Fracture Reduction? A Propensity-matched Comparative Study

BACKGROUND

Preoperative planning is generally performed to simulate the process of reduction as well as to determine the size and placement of implants in patients undergoing distal radius fracture surgery. We previously described a three-dimensional (3D) digital preoperative planning system for the osteosynthesis of distal radius fractures, and we have developed a novel intraoperative referencing system that superimposes preoperative planning (such as plate position and length) onto fluoroscopic images during surgery; however, its efficacy has not been evaluated compared with conventional planning and surgery.

QUESTIONS/PURPOSES

Does use of a novel intraoperative referencing system result in (1) better Mayo wrist scores at 3 and 6 months after surgery and (2) less loss of reduction in terms of ulnar variance, palmar tilt, and radial inclination on plain radiographs taken 1 week, 3 months, and 6 months after surgery compared with conventional preoperative planning?

METHODS

Between April 2014 and October 2021, we treated 294 patients with open reduction and volar plate fixation for distal radius fractures. Of 294 patients, 65% (191) underwent surgery using either conventional preoperative planning or a novel intraoperative referencing system. The remaining patients were excluded because they were younger than 18 years, they had some missing medical records related to the clinical outcomes, or they had a previous history of upper extremity injuries. During that time, we generally treated fractures with volar plates when there was: more than 2 mm of stepoff/gap in the articular surface, a dorsal tilt more than 15°, radial inclination less than 15°, or radial shortening more than 5 mm. Generally, we used a flexor carpi radialis approach. In some patients who had dorsal fragments, we added a dorsal approach. At that time, we were developing the new intraoperative referencing system, so it was not used consistently. To arrive at a fair assessment, we opted to perform propensity matching based on age, gender, and AO fracture type. During the period in question, 36% (69 of 191) of patients with distal radius fractures who received a volar plate were treated using our novel intraoperative referencing system, and 64% (122 of 191) had surgery using conventional preoperative planning (control group). Of those, 91% (63 of 69) of patients who were treated with the intraoperative referencing system and 89% (108 of 122) of those in the control group were available for follow-up with all imaging and Mayo wrist scores at least 6 months after surgery. After propensity matching, that left us with two groups of 39 patients, who were well matched in terms of age and fracture type; these were the study groups. We also tried to match them according to gender, but there were fewer patients in the intraoperative referencing group, and the percentage of women for each group differed: 70% (44 of 63) in the intraoperative referencing group and 76% (82 of 108) in the control group. Also, there were fewer men with C3 fractures in the control group. Therefore, 64% (25 of 39) of patients in the intraoperative referencing group were women and 77% (30 of 39) of patients in the control group were women. In the intraoperative referencing group, our novel intraoperative referencing system was used in combination with the 3D digital preoperative planning system for preoperative planning. In the control group, preoperative planning was performed manually in a conventional manner using tracing paper and implant templates or using a digital template. We compared the groups in terms of operative duration, the radiation dose used in surgery, and Mayo wrist scores at 3 and 6 months after surgery. We also compared the groups in terms of loss of reduction on ulnar variance, palmar tilt, and radial inclination on plain radiographs taken 3 months and 6 months after surgery. We considered the plain radiograph taken 1 week after surgery as a baseline. Each item was compared between the image fusion and control groups using a Welch t - test.

RESULTS

Mayo wrist scores were no different between the intraoperative referencing system and the control group at 3 months (71 ± 7 versus 72 ± 11, mean difference 1 [95% CI -3.7 to 5.7]; p = 0.07) or at 6 months after surgery (76 ± 6 versus 79 ± 11, mean difference 3 [95% CI -3.5 to 7.9]; p = 0.12). There were no differences in surgical duration or radiation doses between the intraoperative referencing and control groups. We found only a small advantage in favor of the intraoperative referencing system in terms of loss of reduction on ulnar variance (3 months after surgery: 0.2 ± 0.4 mm versus 0.6 ± 0.7 mm, mean difference 0.4 mm [95% CI 0.15 to 0.69]; p = 0.003, 6 months after surgery: 0.4 ± 0.6 mm versus 0.8 ± 0.8 mm, mean difference 0.4 mm [95% CI 0.05 to 0.73]; p = 0.02 for the intraoperative referencing system and the control group, respectively). This difference in radial shortening was so small that it was not likely to have been clinically important.

CONCLUSION

We found no clinically important advantages from the use of our novel intraoperative referencing system except a slight improvement in ulnar variance. Therefore, we recommend against its use in everyday practice at this time. However, future improvements may lead to better clinical outcomes, so we plan further investigations.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Changes in Distance Between the Flexor Pollicis Longus Tendon and Volar Locking Plate: An Ultrasonographic Study

PURPOSE

Flexor pollicis longus rupture is a major complication after volar locking plate fixation of distal radius fractures. Although the distance between the flexor pollicis longus tendon and the plate (plate-tendon distance) measured by ultrasonography is used to predict tendon rupture risk, the timing of the ultrasonography can affect the measurements. Therefore, this study aimed to analyze the chronological change of the plate-tendon distance between the tendon and plate.

METHODS

A total of 166 wrists underwent the plate-tendon distance measurement twice or more times within 15 months after surgery. Longitudinal ultrasonography scans with the wrist in a neutral position and the thumb flexed were used to measure the plate-tendon distance. The plate-tendon distances at 0-5 months, 5-10 months, and 10-15 months after surgery were compared. A multiple linear regression analysis was performed to evaluate the influence of the interval between surgery and examination, Soong grade, and plate type on the plate-tendon distance.

RESULTS

The plate-tendon distance decreased as the interval between surgery and examination increased. The plate-tendon distance was an average of 2.0 ± 1.1 mm, 1.4 ± 0.9 mm, and 1.2 ± 0.9 mm at 0-5 months, 5-10 months, and 10-15 months after surgery, respectively. Significant differences were observed between 0-5 months and 5-10 months and between 5-10 months and 10-15 months after surgery. A multiple linear regression showed that significant predictors of the plate-tendon distance were the intervals between surgery and examination and Soong grade.

CONCLUSIONS

The plate-tendon distance decreased as the time since surgery increased. When ultrasonography is used for the assessment of tendon rupture risk, it should be considered that the plate-tendon distance decreases as the interval between the surgery and examination increases.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognosis IV.

Can we safely place the distal volar locking plate screws into the subchondral zone of a distal radius fracture using a 45° supination oblique view under fluoroscopic guidance?

INTRODUCTION

Careful distal locking screw insertion into the subchondral zone is necessary to obtain proper mechanical strength of unstable distal radius fractures using volar locking plating. However, subchondral zone screw insertion increases the risk of intra-articular screw penetration, which may remain unrecognized during surgery due to complex distal radial anatomy. The purpose of this study was to evaluate the role of fluoroscopic guidance with a 45° supination oblique view technique for placing distal screws into the subchondral zone during volar locking plating for unstable distal radius fractures and to explore the factors associated with poor screw placement.

METHODS

We retrospectively analyzed 171 wrists of 169 patients treated with variable-angle volar locking plates for unstable radius fractures. The subchondral zone was defined as the metaphyseal area within 4 mm of the articular margin of the distal radius. The location of the distal locking screws and radiographic parameters, including the teardrop angle, were measured using computed tomography scans and X-rays. Clinical and radiographic factors were examined to determine their possible associations with screw placement failure.

RESULTS

Of 581 distal screws inserted, 559 screws (96.2%) were inserted into the subchondral zone and 17 screws into the metaphyseal zone (2.9%). Five screws (0.7%) in three wrists showed intra-articular placement: four screws were placed into the lunate fossa and one into the scaphoid fossa. These three wrists also exhibited significantly reduced teardrop angles. The distal screws were significantly closer to the joint line in the lunate fossa than the scaphoid fossa (1.9 ± 0.9 mm vs. 2.8 ± 1 mm, P < 0.000).

CONCLUSION

The 45° supination oblique view technique is a useful fluoroscopic guiding technique for accurate and safe distal screw placement in the subchondral zone in volar locking plate fixation for distal radial fractures. However, a decreased teardrop angle or extended lunate fossa should be corrected before distal screw insertion to avoid intra-articular screw placement.

Three-dimensional imaging of the distal radius with reference to volar locking plate surgery

BACKGROUND

The watershed line is widely accepted as the distal limit of the volar locking plate (VLP); however, the VLP placement could vary depending on the plate contour and morphology of the distal radius. The aim of this study was to investigate the morphology of the distal radius and VLP fitting using 3D images.

HYPOTHESIS

We hypothesized that attachment of the VLP would affect the contour of the volar prominence of the distal radius.

PATIENTS AND METHODS

Variable-angle LCP two-column volar distal radius Plate 2.4 and 16 formalin-fixed cadavers were studied. The plate and forearm were scanned using a computed tomography scanner. The plate was fixed to the radial shaft in the most distal position without flexor pollicis longus tendon contact. Postero-antero and lateral radiographs were obtained using fluoroscopy. Postero-antero radiographs were superimposed on a 3D image of the distal radius. The virtual plate was attached to the distal radius in the computer simulations and the plate was adjusted in the sagittal plane. In the postero-antero radiographs, the distance between the plate and distal end of the radius (DPR) was measured. In the sagittal plane, the height of the volar lunate facet (VLF) and the plate-to-bone distance of each locking screw hole was measured. The volar cortical angle (VCA) was measured as the angle formed by a line drawn along the volar surface and a line drawn on the radial shaft on the sagittal plane at each locking screw plane.

RESULTS

A significant correlation was observed between the height of the VLF and the DPR and between the height of the VLF and the VCA. The plate-to-bone distance at the ulnar screw hole was significantly smaller than that of the other screw holes.

DISCUSSION

Our study revealed that the higher the VLF, the more proximal is the VLP. The plate fits on the bone surface at the ulnar side, whereas the radial side has more space between the plate and bone.

LEVEL OF EVIDENCE

III, diagnostic Level.

Systematic use of short unicortical epiphyseal locking screws versus full-length unicortical locking screws in distal radius fracture volar plating: A prospective and comparative study

PURPOSE

Volar locking plates, used in distal radius fracture (DRF), present a risk of injuring extensor tendons with screws penetrating the dorsal cortex of the radius. Actually, even when aiming to use maximum-length unicortical locking screws, some still could be bicortical. We hypothesize the use of only short unicortical screws would allow a proper stabilization of the radial epiphysis without the risk of dorsal cortex penetration.

MATERIALS AND METHODS

A prospective monocentric non-randomized study was conducted. Patients with DRF (excepted for partial dorsal joint fractures) were treated in group A with short locking epiphyseal screws (16 mm for females, 18 mm for males) and in group B with full-length unicortical locking screws. Ultrasound was done 3 months postoperatively to evaluate the number and length of prominent dorsal screws. X-rays were performed after 6 weeks to assess stability according to volar tilt and radial inclination variations.

RESULTS

There were 37 patients in group A and 39 in group B with 148 and 156 epiphyseal screws, respectively. In group A, there were 0% of dorsal penetrating screws against 6.5% (10 screws from 8 patients) in group B (p < 0.05). There was no significant difference for the stability between the groups: mean volar tilt variation ( - 0.6° vs. - 0.7°) and mean radial inclination variation ( - 0.4° vs. - 0.4°).

CONCLUSION

For a same stability with volar locking plates for DRF, short epiphyseal locking screws should be preferred to full-length unicortical screws in order to prevent extensor tendon injuries. Based on 75% of distal radial average anteroposterior width for each sex, screw lengths of 16 mm for females and 18 mm for males seem to be the length to use. LEVEL OF EVIDENCE 2: Prospective, Comparisons made, non-randomized.

Biomechanical evaluation of the stability of extra-articular distal radius fractures fixed with volar locking plates according to the length of the distal locking screw

Surgeons usually used short screws to avoid extensor tendon problems during volar locking plate fixation in distal radius fracture. However, the stability according to the length of distal locking screws have not been fully understood. We investigated this issue through finite element analysis and compression test using synthetic radius. Our results demonstrated that the bi-cortical full-length fixation does not contribute to the stiffness increase in the axial compression direction, and a reduction in length of up to more than 50% length can still provide similar stability to full-length screws. Our data can support that surgeon should undersize the distal screw.

Cartilage and subchondral bone distributions of the distal radius: a 3-dimensional analysis using cadavers

OBJECTIVE

To quantify the spatial distributions of cartilage and subchondral bone thickness of the distal radius.

DESIGN

Using 17 cadaveric wrists, three types of 3-dimensional models were created: a cartilage-bone model, obtained by laser scanning; a bone model, rescanned after dissolving the cartilage; and a subchondral bone model, obtained using computed tomography. By superimposing the bone model onto the cartilage-bone and the subchondral bone models, the cartilage and subchondral bone thickness were determined. Measurements along with the spatial distribution were made at fixed anatomic points including the scaphoid and lunate fossa, sigmoid notch and interfossal ridge, and compared at each of these four regions.

RESULTS

Cartilage thickness of the interfossal ridge (0.89 ± 0.23 mm) had a larger average thickness compared to that of the scaphoid fossa (0.70 ± 0.18 mm; p = 0.004), lunate fossa (0.75 ± 0.17 mm; p = 0.044) and sigmoid notch (0.64 ± 0.13 mm; p < 0.001). Subchondral bone was found to be thickest at the scaphoid (2.18 ± 0.72 mm) and lunate fossae (1.94 ± 0.93 mm), which were both thicker than that of sigmoid notch (1.63 ± 1.06 mm: vs scaphoid fossa, p = 0.020) or interfossal ridge (1.54 ± 0.84 mm: vs scaphoid fossa, p = 0.004; vs lunate fossa, p = 0.048). In the volar-ulnar sub-regions of the scaphoid and lunate fossa, the subchondral bone thickened.

CONCLUSIONS

Our data can be applied when treating distal radius fractures. Cartilage thickness was less than 1 mm across the articular surface, which may give an insight into threshold for an acceptable range of step-offs. The combined findings of subchondral bone appreciate the importance of the volar-ulnar corner of the distal radius in the volar locking plate fixation.

Volar Locking Plate Fixation for Distal Radius Fractures by Intraoperative Computed Tomographic–Guided Navigation

Purpose

Unstable distal radius intra-articular fractures require restoration of alignment. Exact fixation of intra-articular fragments is ideal. Here, we employed intraoperative computed tomography (CT) navigation to insert screws accurately in the intra-articular dorsal fragments during treatment with a volar locking plate for distal radius intra-articular fractures. The main purposes of this study were to evaluate the accuracy of this procedure and the postoperative stability of the articular fragments through CT findings, as well as to assess clinical outcomes.

Methods

This study included 26 patients with distal radius fractures, who were treated with a volar locking plate using intraoperative CT navigation with a minimum follow-up of 12 months. Mean patient age was 63 years and mean follow-up was 16 months. We examined the position of the inserted distal screws and articular displacement on preoperative, intraoperative, and post–bone union CT images. The 3 distal ulnar screw positions that influence the stability of the dorsoulnar articular fragment were evaluated. The Mayo wrist score and Disabilities of the Arm, Shoulder, and Hand score were also clinically evaluated.

Results

Computed tomography evaluation revealed that the distal locking screws were appropriately inserted at the subchondral position, with sufficient length to stabilize the dorsal fragments, and reduction and stability of the articular fragment were acceptable. At the final follow-up, mean Mayo wrist score was 90.8 and mean Disabilities of the Arm, Shoulder, and Hand score was 9.6.

Conclusions

Intraoperative CT navigation was successfully used for volar locking plate fixation of intra-articular distal radius fractures. Computed tomography evaluation revealed that the screws were precisely inserted for articular fragments and bone union was achieved, maintaining good intra-articular alignment. The findings demonstrate the accuracy of volar locking plate fixation assisted by intraoperative CT navigation and the good clinical outcomes of this procedure.

Type of study/level of evidence

Therapeutic IV.

Ulnar facet locking screw locations of volar locking plates placed without flexor pollicis longus tendon contact: A cadaver study

BACKGROUND

The volar locking plate (VLP) system provides stable fixation and is widely used for distal radius fractures. Studies have shown that irritation of the implant prominence is a risk factor for flexor tendon rupture, especially of the flexor pollicis longus (FPL). Contact between VLPs and flexor tendons should be avoided. We aimed to investigate the ulnar facet locking screw locations of various VLPs placed without FPL tendon contact in cadaver wrists.

HYPOTHESIS

We hypothesized that ulnar facet locking screws would be in the vicinity of the subchondral bone when the plate is placed in the most distal position without FPL tendon contact.

MATERIALS AND METHODS

The study assessed two variable-angles and four fixed locking plates. We placed each plate in six different cadavers, resulting in 36 different plate-cadaver combinations. Plates were placed in the most distal position without FPL tendon contact. We drilled the most ulnar hole (hole A) and the second ulnar hole (hole B) of the distal row. All drilling procedures were performed using a specific jig for each fixed locking plate. For variable-angle locking plates, we drilled with a fixed jig for each plate. We obtained lateral radiographs when the drill penetrated the dorsal cortex and measured the distance between the drill and the articular surface.

RESULTS

With regard to hole A, the mean distances between the drill and the center of the articular surface were 2.6-5.2mm for the four fixed locking plates and 4.9-5.6mm for the two variable-angle locking plates. With regard to hole B, the mean distances between the drill and the center of the articular surface were 3.8-5.9mm for the four fixed locking plates and 5.5-5.9mm for the two variable-angle locking plates.

DISCUSSION

When clinicians place a VLP without FPL tendon contact, the distance between the ulnar facet screws and the center of the articular surface is over 3mm in most cases. Surgeons should select variable-angle drilling for strong articular support when using variable-angle locking plates.

LEVEL OF EVIDENCE

III, diagnostic Level.

Evaluating the necessity of bone augmentation for distal radius fracture fixed with a volar locking plate: a retrospective study

Background

Multiple approaches for fixation of distal radius fractures exist; nonetheless, there is no consensus on the optimal treatment for these injuries. Although using volar locking plates has become increasingly common as a surgical intervention, the usefulness of bone augmentation remains debatable. Therefore, this study aimed to evaluate the necessity of bone augmentation for distal radius fractures fixed with a volar locking plate.

Methods

This retrospective study enrolled patients with a single distal radius fracture treated with a volar locking plate between January 2014 and December 2016. Overall, 105 fractures were included and divided into two groups (non-bone augmentation: group 1, n = 88; bone augmentation: group 2, n = 17). Images were reviewed, and dorsal cortex collapse, volar tilting, and radial height and inclination were measured immediately after surgery and at the 6-month follow-up.

Results

Both groups exhibited significant differences in dorsal collapse (p < 0.001 and p = 0.001, respectively) and radial height shortening (p < 0.001 and p = 0.039, respectively); volar tilting and radial inclination did not differ significantly. There was no difference in the degree of dorsal collapse (p = 0.715) and radial height shortening (p = 0.651) between the two groups. Of the 105 fractures, 54 were identified as comminuted type according to the AO classification (A3, C2, and C3), and similar radiographic outcomes were noted.

Conclusions

Volar locking plates for the treatment of distal radius fractures with or without bone augmentation do not affect the radiographic outcomes. In comminuted fractures, additional bone augmentation is unnecessary if intraoperative anatomical reduction and fixation are performed when possible.

Utility of an image fusion system for 3D preoperative planning and fluoroscopy in the osteosynthesis of distal radius fractures

Background

Recently, 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.

Methods

Forty-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.

Results

The 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).

Conclusions

The image fusion system was useful to reproduce the planned plate position and distal screw choices in the osteosynthesis of distal radius fractures.

Trial registration

ClinicalTrials.gov, NCT03764501

Emerging Technologies in Distal Radius Fracture Fixation

PURPOSE OF REVIEW

To provide an overview of emerging fixation constructs and materials used in the operative management of distal radius fractures.

RECENT FINDINGS

The indications, advantages, and disadvantages of relatively new implants and devices used to treat distal radius fractures are discussed. These include the intramedullary nail, intramedullary cage, radiolucent volar locking plate, distal radius hemiarthroplasty, and bone graft substitutes. The spectrum of distal radius fracture patterns may make it impossible to depend on a single device for fixation, and surgeons managing distal radius fractures should be adept at using various surgical approaches, techniques, and hardware systems. Additional studies demonstrating the cost-effectiveness, biomechanical properties, and clinical outcomes will be useful in determining the utility of the described techniques.

A technical note on the reduction of distal radius fractures with angular stable plates

Plating of distal radius fractures is a common procedure. Especially in busy practices the procedure is mostly performed by a single surgeon. By the use of a distance holder screw in the most proximal hole of the shaft of an angular stable distale radius plate a Lever arm can be created that allows indirect reduction of a dorsal ly displaced distal radius fracture. The method described here may facilitate the Operation in that the articular block can be securely fixed while the plate is stable centered on the shaft of the radius. Especially for single surgeon operations this may save time. In contrast the costs of an extra angular stable screw must be accepted.

What happens to the posterior comminution in extra-articular fractures of the distal radius treated with volar locking plates?

Extra-articular fractures of the distal radius with posterior displacement are typically treated with volar locking plates. However, this fixation method does not address the posterior comminution, which seems to have no impact on the final result. The purpose of this study was to determine the fate of the posterior comminution. This was a retrospective study of 22 patients over 50 years old with a distal radius fracture. A preoperative computed tomography (CT) scan was performed to evaluate the comminution. All fractures were fixed with a volar locking plate. All patients underwent a bone density scan. Patients were reviewed at 6 months post-operative to determine their clinical, radiological and functional outcomes. The CT scan was performed again to determine the fate of the comminution. At 6 months post-operative, 82% of patients had an oval metaphyseal defect. The mean volume of this defect was 1.86 mL. The contents of this defect most closely resembled fat. There was no statistical link between the defect's volume and the various parameters studied. On the other hand, the defect's density was positively related to the functional outcome and negatively related to the patients' body mass index. Because of the compression experienced by the cancellous bone, a distal metaphyseal defect often persists after consolidation in dorsally displaced distal radius fractures. The posterior comminution is ultimately of little consequence.

Screw placement is everything: Risk factors for loss of reduction with volar locking distal radius plates

AIM

To determine factors correlated with postoperative radial shortening in patients with distal radius fractures treated with volar locking distal radius plates.

METHODS

A total of 250 patients with a distal radius fracture stabilised with volar locking plates between January 2010 and December 2014 were included in a multicentre retrospective cohort study. We measured the distance of the distal locking screws to the joint line immediately postoperatively and then measured radial shortening after six to eight weeks using the change in ulnar variance.

RESULTS

Multivariate linear regression analysis showed that there was a significant linear association between the distance of the screws from the joint line and radial shortening. No other patient, injury, or treatment-related characteristic significantly influenced radial shortening in multivariate analysis.

CONCLUSION

Distal locking screws should be placed as close as possible to the subchondral joint line to prevent postoperative loss of reduction.

Volar Locking Plate Fixations for Displaced Distal Radius Fractures: An Evaluation of Complications and Radiographic Outcomes

BACKGROUND

A volar locking plate (VLP) is the most frequently used form of implant used for open reduction and internal fixation of distal radius fractures. They are known to have a complication rate of up to 27%. We hypothesized that plate design could influence complication rates.

METHODS

We performed a review of patients undergoing VLP fixation for distal radius fracture. A total of 228 patients underwent fixation with the Distal Volar Radial Anatomical (DVR) plate; 388 patients underwent fixation with the VariAx plate. Independent observers performed blinded case note and radiographic review, to assess for the quality of reduction, and complications for the inserted VLP.

RESULTS

Mean time to surgery was 6.0 days; mean follow-up was 17.5 weeks. Mean age was 56.5 years. The quality of reduction was classified as anatomical (46%), good (36.3%), moderate (13.0%), or poor (3.9%). Complications were identified in 109 patients (17%). Plate prominence was seen in 133 patients (21%). The DVR plate was less prominent ( P < .001) and had better overall radiographic appearances ( P = .025). Flexor tendon complications were related to plate prominence ( P = .005). Inferior reduction was associated with increased time to surgery ( P = .020).

CONCLUSIONS

This study highlights the importance of prompt surgery, effective fracture reduction, and careful plate positioning to avoid volar prominence.

[Biomechanics of distal radius fractures : Basics principles and GPS treatment strategy for locking plate osteosynthesis]

Fractures of the distal radius are most commonly caused by hyperextension injuries of the wrist. Tensile forces and force vectors, strength of impact, bone strength and soft tissue tension create individually different fracture patterns. Metaphyseal comminution, loss of cortical support, ligament avulsion and shear fragments are defining parameters for fracture instability. The dislocation of the articular fragment follows the force vectors of the extrinsic forearm muscles bridging the joint. The goal-plan-standardized (GPS) treatment strategy has proven to be helpful in choosing the ideal individual treatment. It is based on individual patient demands on wrist function and an analysis of fracture instability in computed tomography (CT) scans. The "goal" is a realistic expectation assessed by patient and surgeon. The "plan" includes a benefit-risk analysis and selection of an appropriate treatment modality. The "standardized treatment" of surgical and follow-up treatment is based on biomechanical knowledge. Locking plate osteosynthesis aims to neutralize dislocating force vectors and to allow early active mobility. Unidirectional instability can be indirectly neutralized by palmar locking plate systems. A multidirectional instability can be addressed by multiple plating following the column theory. Distal shear and avulsion fractures may require a fragment-specific osteosynthesis approach.

Flexor tendon complications in comminuted distal radius fractures treated with anatomic volar rim locking plates

OBJECTIVE

Anatomic volar rim locking plates are designed with the aim of treating intraarticular distal radius fractures. When used to treat comminuted distal radius fractures, these plates can damage the flexor tendons. In this study, we sought to determine the radiological and functional results and rate of complications of these plates.

METHODS

We retrospectively reviewed the records of 36 patients (28 males, 8 females; mean age: 46.4 years) with AO/OTA Type C2-C3 distal radius fractures treated with anatomic volar rim distal radius plates between January 2011 and December 2014. Radial length, radial inclination and palmar tilt were compared with the intact wrist. Results were evaluated with the Mayo wrist and Lidstrom scores. Complications were documented throughout the follow-up period of 23.8 (range: 12 to 48) months.

RESULTS

Postoperative measurements of the radial length, inclination and palmar tilt did not differ significantly. Mayo wrist and Lidstrom scores were good and excellent in 27 and 32 patients, respectively. Flexor tenosynovitis was symptomatic in 15 patients and asymptomatic (localized swelling only) in 21. Plates were removed from 15 patients due to symptomatic tenosynovitis and from six patients due to partial rupture of the flexor pollicis longus tendon. The flexor digitorum profundus tendon of the second finger was also partially ruptured in three patients.

CONCLUSION

Anatomic volar rim locking plates provide satisfying radiological and functional results in treating AO/OTA Type C2-C3 comminuted distal radius fractures. However, if these plates interfere with the union of the fracture, they should be removed to avoid potential tendon problems caused by their placement in the rim region.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.

Pearls and Pitfalls of the Volar Locking Plating for Distal Radius Fractures

Volar locking plate fixation has been widely accepted method for the treatment of unstable distal radius fractures. Although the results of volar locking plate fixation are encouraging, it may cause implant-related complications such as flexor or extensor tendon injuries. In depth understanding of anatomy of the distal radius is mandatory in order to obtain adequate fixation of the fracture fragments and to avoid these complications. This article will review the anatomic characteristics of the distal radius because selecting proper implant and positioning of the plate is closely related to the volar surface anatomy of the distal radius. The number and the length of distal locking screws are also important to provide adequate fixation strength to maintain fracture fixation. We will discuss the pros and cons of the variable-angle locking plate, which was introduced in an effort to provide surgeons with more freedom for fixation. Finally, we will discuss about correcting radial length and volar tilt by using eccentric drill holes and distal locking first technique.

Interindividual anatomical variations affect the plate-to-bone fit during osteosynthesis of distal radius fractures

We hypothesized that interindividual variations in the teardrop, which represents the volar projection of the lunate facet of the distal radius, cause unsatisfactory fitting of the volar locking plate to the bone. This can cause flexor tendon ruptures. Herein, we conducted a cross-sectional study and measured the ratio of teardrop height and the teardrop inclination angle as parameters of teardrop configuration for 200 standardized lateral radiographs (average age of the patients, 51 years). We also quantified the influence of the teardrop morphology by analyzing the fit of three locking plates to three radii with differing teardrop inclination angles using a three-dimensional computer-aided design system. The average ratios of the teardrop height and teardrop inclination angle were 0.42° (0.30-0.56°) and 28.8° (9.9-44.9°), respectively. The teardrop inclination angle was moderately correlated with age in men but not in women. In the plate-to-bone fit analyses, the fit of all the plates was significantly different between bones, with the configuration of the radius with the lowest teardrop inclination angle being the closest approximation to that of each plate. We demonstrated the interindividual variation in the shape of the teardrop and its influence on the fit of the volar plate, highlighting the importance of careful plate selection for achieving osteosynthesis of bones with a high teardrop inclination angle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:953-960, 2016.

Optimal Positioning for Volar Plate Fixation of a Distal Radius Fracture: Determining the Distal Dorsal Cortical Distance

Distal radius fractures are currently among the most common fractures of the musculoskeletal system. With a population that is living longer, being more active, and the increasing incidence of osteoporosis, these injuries will continue to become increasingly prevalent. When operative fixation is indicated, the volar locking plate has recently become the treatment of choice. However, despite its success, suboptimal position of the volar locking plate can still result in radiographic loss of reduction. The distal dorsal cortical distance is being introduced as an intraoperative radiographic tool to help optimize plate position and minimize late loss of fracture reduction.

Postsurgical complications following distal radius volar plating in a diabetic population at short-term follow-up

BACKGROUND

Diabetes mellitus increases the risk of complications following operative treatment of lower extremity fractures. There is little published data establishing the impact of diabetes following surgical treatment of upper extremity fractures. This investigation aimed to compare the incidence of short-term postsurgical complications following volar locked plating of distal radius fractures in patients with and without diabetes.

METHODS

A retrospective matched cohort investigation of 33 diabetics matched 1:2 to 66 non-diabetics was performed, accounting for age, gender, fracture type, and smoking status. Electronic medical records and radiographs were reviewed for all major and minor postsurgical complications. Demographic characteristics, postoperative radiographic parameters, and final range of motion were also compared. Mean follow-up was 5.3 ± 8.2 and 5.5 ± 7.8 months for diabetics and non-diabetics, respectively.

RESULTS

The diabetic cohort had a significantly higher overall complication rate with 24 postsurgical complications affecting 12 patients (36 %) compared to 16 complications affecting 12 patients (18 %) in the non-diabetic cohort. There was no difference in the incidence of major complications requiring operative intervention. Minor complications were significantly more common in the diabetic group and were largely accounted for by peripheral neuritis with an incidence of 30 %. Final radiographic outcomes and range of motion were similar.

CONCLUSIONS

Diabetics experienced a greater incidence of minor postsurgical complications following volar locked plating of distal radius fractures when compared to a matched, control population. The difference in outcomes is largely accounted for by the increased incidence of peripheral neuritis among diabetics. Diabetic patients should be counseled pre-operatively regarding their elevated risk profile.

Comparison of intraoperative flat panel imaging and postoperative plain radiography for the detection of intraarticular screw displacement in volar distal radius plate ostheosynthesis

OBJECTIVES

To investigate if intraoperative 3D flat panel imaging improves the detection of radiocarpal intraarticular screw misplacement (RCSM) in comparison to standard postoperative x-ray.

METHODS

In a study on cadaver specimens, we evaluated the sensitivity and specificity to detect RCSM using X-ray, intraoperative 3D-fluoroscopy as well as the digital volume tomography. The gold standard reference was computed tomography.

RESULTS

Sensitivity for the detection of RCSM for X-ray was 58% and specificity 88%. For DVT, the sensitivity to detect RCSM was 88% and the specificity 53%. For 3D-fluoroscopy, the sensitivity for RCSM was 68% and specificity 95%. When combining the methods, the best performance was found, when combining the two intraoperative imaging methods, with a resulting sensitivity of 88% and a specificity of 73%.

CONCLUSIONS

Intraoperative 3D fluoroscopy and digital volume tomography appear to be at least as sensitive and specific to detect RCSM than the regular postoperative radiography in two planes. However, especially discrete screw misplacements can be missed with either method.

LEVEL OF EVIDENCE

Level IV. Diagnostic device study.

Tangential View and Intraoperative Three-Dimensional Fluoroscopy for the Detection of Screw-Misplacements in Volar Plating of Distal Radius Fractures

Background:

Volar locking plate fixation has become the gold standard in the treatment of unstable distal radius fractures. Juxta-articular screws should be placed as close as possible to the subchondral zone, in an optimized length to buttress the articular surface and address the contralateral cortical bone. On the other hand, intra-articular screw misplacements will promote osteoarthritis, while the penetration of the contralateral bone surface may result in tendon irritations and ruptures. The intraoperative control of fracture reduction and implant positioning is limited in the common postero-anterior and true lateral two-dimensional (2D)-fluoroscopic views. Therefore, additional 2D-fluoroscopic views in different projections and intraoperative three-dimensional (3D) fluoroscopy were recently reported. Nevertheless, their utility has issued controversies.

Objectives:

The following questions should be answered in this study; 1) Are the additional tangential view and the intraoperative 3D fluoroscopy useful in the clinical routine to detect persistent fracture dislocations and screw misplacements, to prevent revision surgery? 2) Which is the most dangerous plate hole for screw misplacement?

Patients and Methods:

A total of 48 patients (36 females and 13 males) with 49 unstable distal radius fractures (22 x 23 A; 2 x 23 B, and 25 x 23 C) were treated with a 2.4 mm variable angle LCP Two-Column volar distal radius plate (Synthes GmbH, Oberdorf, Switzerland) during a 10-month period. After final fixation, according to the manufactures' technique guide and control of implant placement in the two common perpendicular 2D-fluoroscopic images (postero-anterior and true lateral), an additional tangential view and intraoperative 3D fluoroscopic scan were performed to control the anatomic fracture reduction and screw placements. Intraoperative revision rates due to screw misplacements (intra-articular or overlength) were evaluated. Additionally, the number of surgeons, time and radiation-exposure, for each step of the operating procedure, were recorded.

Results:

In the standard 2D-fluoroscopic views (postero-anterior and true lateral projection), 22 screw misplacements of 232 inserted screws were not detected. Based on the additional tangential view, 12 screws were exchanged, followed by further 10 screws after performing the 3D fluoroscopic scan. The most lateral screw position had the highest risk for screw misplacement (accounting for 45.5% of all exchanged screws). The mean number of images for the tangential view was 3 ± 2.5 images. The mean surgical time was extended by 10.02 ± 3.82 minutes for the 3D fluoroscopic scan. An additional radiation exposure of 4.4 ± 4.5seconds, with a dose area product of 39.2 ± 14.5 cGy/cm² were necessary for the tangential view and 54.4 ± 20.9 seconds with a dose area product of 2.1 ± 2.2 cGy/cm², for the 3D fluoroscopic scan.

Conclusions:

We recommend the additional 2D-fluoroscopic tangential view for detection of screw misplacements caused by overlength, with penetration on the dorsal cortical surface of the distal radius, predominantly observed for the most lateral screw position. The use of intraoperative 3D fluoroscopy did not become accepted in our clinical routine, due to the technical demanding and time consuming procedure, with a limited image quality so far.

Morphology of distal radius curvatures: a CT-based study on the Malaysian Malay population

INTRODUCTION

The purpose of this study was to examine the differing curves of the volar distal radius of healthy Malaysian Malays, so as to obtain detailed morphological information that will further the understanding of volar plate osteosynthesis in Malaysian Malays.

METHODS

Computed tomography with three-dimensional reconstruction was performed on the wrists of 16 healthy Malaysian Malay volunteers. Profile measurements were made using a software program. A novel parameter, the pronator quadratus curve angle, was explored and introduced in this study. Interclass correlation coefficients were calculated to assess the level of agreement between the data collected by the principal investigator and that collected by an independent radiologist.

RESULTS

The mean ± standard deviation of the arc radii on the radial aspect was 17.50° ± 5.40°, while the median (interquartile range [IQR]) of the arc radii on the ulnar aspect was 25.27° (IQR 5.80°). The mean ± standard deviation of the curvature of the pronator quadratus line was 40.52° ± 2.48°. The arc radii on the radial aspect was significantly lower than the arc radii on the ulnar aspect (p = 0.001). Different radial and ulnar arcs were observed in 56.25% of the radii; the arc was deeper on the ulnar aspect in 93.75% of the radii.

CONCLUSION

Based on the findings of this study, the likelihood of achieving anatomical reduction with uniformly curved, fixed-angle volar plates is questionable. Changes in the design of these implants may be needed to optimise their usage in the Malaysian Malay population.

[Intraoperative virtual implant planning for volar plate osteosynthesis of distal radius fractures]

BACKGROUND

Digital planning of implants is in most cases conducted prior to surgery. The virtual implant planning system (VIPS) is an application developed for mobile C-arms, which assists the virtual planning of screws close to the joint line during surgery for treatment of distal radius fractures with volar plate osteosynthesis. The aim of this prospective randomized study was to acquire initial clinical experiences and to compare the VIPS method with the conventional technique.

METHOD

The study included 10 patients for primary testing and 30 patients with distal radius fractures of types A3, C1 and C2, divided in 2 groups. In the VIPS group, after placement of the plate and fracture reduction, a virtual 3D model of the plate was matched with the image of the plate from the fluoroscopic acquisition. Next, the length and position of the screws close to the joint line were planned on the virtual plate. The control group was treated with the same implant in the conventional way. Data were collected regarding screw replacement, fluoroscopy and operating room (OR) times.

RESULTS

The VIPS group included six A3, one C1 and eight C2 fractures, while the control group consisted of six A3 and nine C2 fractures. Three screws were replaced in the VIPS group and two in the control group (p = 0.24). The mean intraoperative fluoroscopy time of the VIPS group amounted to 2.58 ± 1.38 min, whereas it was 2.12 ± 0.73 min in the control group (p = 0.26). The mean OR time in the VIPS group was 53.3 ± 34.5 minutes and 42.3 ± 8.8 min (p = 0.23) in the control group.

CONCLUSION

The VIPS enables a precise positioning of screws close to joint line in the treatment of distal radius fractures; however, for routine use, further development of the system is necessary.

Can the use of variable-angle volar locking plates compensate for suboptimal plate positioning in unstable distal radius fractures? A biomechanical study

OBJECTIVE

To compare the biomechanical stability under load-to-failure conditions of optimally placed fixed-angle volar locking plates versus suboptimally placed variable-angle volar locking plates in unstable, intraarticular distal radius fractures.

METHODS

A Melone type 1 (AO 23-C3) fracture was created in 25 sawbone radii and plated with either a fixed-angle or variable-angle Synthes plate with identical profile. Four plate positions were tested: distal ulnar (DU, positioned distally to obtain subchondral support and ulnar to hold the lunate facet fragments), distal radial (DR, 3 mm radial to DU), proximal ulnar (PU, 3 mm proximal to DU), and proximal radial (PR, 3 mm proximal and 3 mm radial to DU). The specimens were loaded until failure as defined by a 2-mm displacement of any fracture fragment. The fixed-angle plates were tested in the DU position, whereas the variable-angle plates were tested in all 4 positions.

RESULTS

The dorsal lunate fragment was the first to fail in every group followed by the radial styloid and volar lunate fragments, respectively. Load-to-failure, from greatest to least, occurred at the DR (278 ± 56 N), PR (277 ± 68 N), DU fixed-angle (277 ± 68 N), DU variable-angle (236 ± 31 N), and PU (202 ± 75 N) positions, respectively. Rigidity was calculated using the slope of the dorsal lunate force-displacement curve before failure (at loads 100-150 N). Rigidity was greatest at the PU position (126 ± 60 N/mm) followed by PR (125 ± 30 N/mm), DU fixed-angle (125 ± 25 N/mm), DR (122 ± 66 N/mm), and DU variable-angle (101 ± 35) positions, respectively. Univariate analysis of rigidity and load-to-failure was not significantly different between groups.

CONCLUSIONS

In this experimental model, variable-angle screws provided a leeway of 3 mm in both the sagittal and coronal directions without sacrificing construct strength, which may considerably facilitate fixation of these difficult fractures.

Distal radius fractures: Should we use supplemental bone grafts or substitutites in cases of severe osteoporotic or conminution?

OBJECTIVES

The purpose of this study was to assess the need of bone graft or bone substitutes in unstable distal radius fractures (DRF) treated with locking compression plates (LCP) PATIENTS AND METHODS: An observational and prospective study was conducted on 60 patients with DRF AO-type A3 and AO-type C3, treated surgically by LCP plates without bone grafts or substitutes. Ranges of motion in flexion (F), extension (E), pronation (P), and supination (S) were measured in the injured wrist and compared with the healthy contralateral wrist. X-ray parameters: palmar tilt (PT), radial inclination (RI), ulnar variance (UV), and radial height (RH) were calculated in the injured wrist one year after surgery and then compared, with those parameters in the healthy contralateral wrist and in the follow-up postoperative x-ray of the injured wrist. PRWE and DASH scores were used to evaluate patient satisfaction.

RESULTS

The range of motion loss was F 12° ± 16.1°, E 9° ± 13.1°, P 2.5° ± 7.5°, and S 5°±10°, but they remained within functional parameters. Good results were also obtained in the PRWE and DASH scores (DASH 12.6 ± 14.16 and PRWE 9.5 ± 9.5). All the fractures were healed without significant collapse (IP 0.55 ± 1.7°, IR 0.31 ± 1.5°, VC 0.25±0.8mm, and AR 0.1 ± 0.9 mm).

CONCLUSIONS

All fractures healed without problems or with significant loss of reduction. Bone graft and bone substitutes are not mandatory for treatment of unstable DRF with LCP plates. Their use increases the cost and is not exempt of morbidities. This study also reinforces the role of LCP plates in surgical treatment of unstable DRF.

Polyaxial versus uniaxial volar locking plate for distal radial fractures

PURPOSE

To compare the penetration of the distal screws in relation to the thickness of the distal metaphysis in the polyaxial versus uniaxial volar locking plates.

METHODS

Records of 78 patients aged 16 to 79 years who underwent open reduction and internal fixation for distal radial fractures (n=81) were reviewed. All fracture subtypes were included. 20 men and 22 women aged 18 to 79 (mean, 50) years were treated with the uniaxial locking plate, whereas 15 men and 21 women aged 16 to 79 (mean, 51) years were treated with the polyaxial locking plate. The choice of plate was determined by the operating surgeon based on familiarity and perceived advantages of the 2 plates. Penetration of the distal locking screws in relation to the volar-dorsal thickness of the distal radial metaphysis was measured, and the percentage of subchondral bone unsupported by the screws calculated.

RESULTS

The mean percentage of unsupported subchondral bone was significantly lower in the polyaxial than uniaxial volar locking plate group (12% vs. 23%, p<0.001). No patient had screw over-penetration.

CONCLUSION

The polyaxial volar locking plate system enabled deeper insertion of distal screws into the subchondral bone, and thus providing better buttress for the fracture fragments.

Operative treatment and outcome of unstable distal radial fractures using a palmar T-miniplate at a non-specialized institution

Treatment options for displaced distal radial fractures are still a controversial topic of discussion. Although good results for the palmar plating of high-volume centers have been published, evidence of its successful use in smaller institutions is still lacking. We report the clinical and radiological results of the treatment for 84 distal radial fractures with a single 2.4-mm T-miniplate in an institution performing <30 procedures per year. According to the AO classification system, there were 30 A, 5 B, and 49 C fractures with a patients mean age of 64 years. After a minimum of 12-month follow-up, we found very good and good results according to the Gardland and Sarmiento scores and a DASH of 5.6. Only five patients were classified as having a moderate outcome. A remaining intra-articular step-off of more than 1 mm was seen in 15 patients. In a comparison of grip strength between the injured and uninjured hands, we saw a difference of 6.8 % less on the injured side. We saw two instances of tendon rupture and one of tendon irritation due to prominent dorsal screws and necessitating revision surgery. Flexor tendon irritation was noted in one patient, requiring a second operation. Modern treatment for distal radial fractures can be performed successfully and with good clinical outcome in smaller institutions. Based on the high and increasing incidence of distal radial fractures, there is no need to transfer these patients into high-volume centers. Level of evidence Case study, Level IV.

Intraoperative C-arm CT imaging in angular stable plate 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.

Calcium phosphate cement augmentation after volar locking plating of distal radius fracture significantly increases stability

PURPOSE

Distal radius fractures represent the most common fractures in adults. Volar locking plating to correct unstable fractures has become increasingly popular. Although reasonable primary reduction is possible in most cases, maintenance of reduction until the fracture is healed is often problematic in osteoporotic bone. To our knowledge, no biomechanical studies have compared the effect of enhancement with biomaterial on two different volar fixed-angle plates.

METHODS

Human fresh-frozen cadaver pairs of radii were used to simulate an AO/OTA 23-A3 fracture. In a total of four groups (n = 7 for each group), two volar fixed-angle plates (Aptus 2.5 mm locking fracture plate, Medartis, Switzerland and VA-LCP two-column distal radius plate 2.4, volar, Synthes, Switzerland) with or without an additional injection of a biomaterial (Hydroset Injectable HA Bone Substitute, Stryker, Switzerland) into the dorsal comminution zone were used to fix the distal metaphyseal fragment. Each specimen was tested load-controlled under cyclic loading with a servo-hydraulic material testing machine. Displacement, stiffness, dissipated work and failure mode were recorded.

RESULTS

Improved mechanical properties (decreased displacement, increased stiffness, decreased dissipated work) were found in both plates if the biomaterial was additionally injected. Improvement of mechanical parameters after biomaterial injection was more evident in the Synthes plate compared to the Aptus plate. Pushing out of the screws was noticed as a failure mode only in samples lacking supplementary biomaterial.

CONCLUSIONS

Injection of a biomaterial into the dorsal comminution zone increases stability after volar locking plating of distal radius fractures in vitro.

The mechanical stability of extra-articular distal radius fractures with respect to the number of screws securing the distal fragment

PURPOSE

The treatment of distal radius fractures with volar locked plating (VLP) has gained popularity. Many different designs and sizes of plates afford a wide variety of configurations of locking screws that can be placed into the distal fracture fragment. The purpose of this study was to determine whether using half of the distal locking screws decreased stability when compared with using all possible distal locking screws with 4 different VLP systems.

METHODS

Twenty-four identical synthetic distal radius sawbone models were instrumented with 1 of 4 designs of VLP devices over a standardized dorsal wedge osteotomy to simulate a dorsally comminuted, extra-articular distal radius fracture. Distal locking screws were placed in varying configurations. Six radii per plate model with different screw configurations then underwent axial loading, volar bending, and dorsal bending using a servohydraulic machine. Distal fragment displacement was recorded using a differential variable reluctance transducer.

RESULTS

There was no significant difference in fracture fragment displacement when using half of the distal locking screw set compared with using the full screw set. Mean differences in displacement between half and full screws were less than 0.1 mm. All configurations had the greatest magnitude of displacement during axial loading. Mean displacement was less in plates containing 2 rows of distal locking screws (-0.4 mm) compared with plates containing 1 row (-0.6 mm).

CONCLUSIONS

Using half of the distal locking screws in VLP in an extra-articular, nonosteoporotic distal radial fracture model with noncyclical, nondestructive loading does not decrease construct stability compared with using all of the screws. Not filling all holes in VLP is more cost effective and does not sacrifice plate stiffness or construct stability. Plates with 2 rows of distal locking screws create more stable fixation than plates with 1 row of distal locking screws.

Fixation of distal radius fractures in adults: a review

In patients for whom function is a priority, anatomic reduction and stable fixation are prerequisites for good outcomes. Several therapeutic options exist, including orthopedic treatment and internal fixation with pins (intra- and extrafocal), external fixation which may or may not bridge the wrist, and different internal fixation techniques with dorsal or palmar plates using or not, locking screws. Arthroscopy may be necessary in case of articular fracture. In the presence of significant metaphyseal bone defects, filling of the comminution with phosphocalcic cements provides better graft stability. The level of evidence is too low to allow recommending one type of fixation for one type of fracture; and different fixation options to achieve stable reduction exist, each with its own specific complications. With the new generations of palmar plate, secondary displacement is becoming a thing of the past.

Accuracy of distal radius positioning using an anatomical plate

Over the past decade, several anatomical plates have been introduced to improve the result of open reduction and internal fixation of the distal radius. Using 3-dimensional imaging techniques, the authors studied the accuracy and reproducibility of distal radius positioning using anatomical plates.Distal radius fractures and the correction of these fractures were simulated with plastic bone models of radii. The authors simulated a defect by removing an arbitrary wedge shape from the artificial radii. Two surgeons corrected these fractures by placing 2 anatomical plate types according to the plate manufacturers' instructions. The residual positioning errors of the distal segment in relation to the unaffected radii were determined using 3-dimensional imaging and were compared with naturally occurring bilateral radius differences in healthy individuals. In many cases, positioning does not agree with differences based on bilateral asymmetry in healthy patients.This study indicated the accuracy of anatomical plates. Positioning an anatomical plate may lead to considerable residual errors in individual patients. Volar distal radius plate shapes differ among plate manufacturers. Therefore, one plate may perform better than another in an individual.

More is not necessarily better. A biomechanical study on distal screw numbers in volar locking distal radius plates

INTRODUCTION

Currently available volar locking plates for the treatment of distal radius fractures incorporate at least two distal screw rows for fixation of the metaphyseal fragment and have a variable-angle locking mechanism which allows placement of the screws in various directions There is, however no evidence that these plates translate into better outcomes or have superior biomechanical properties to first generation plates, which had a single distal screw row and fixed-angle locking. The aim of our biomechanical study was to compare fixed-angle single-row plates with variable-angle multi-row plates to clarify the optimal number of locking screws.

MATERIALS AND METHODS

Five different plate-screw combinations of three different manufacturers were tested, each group consisting of five synthetic fourth generation distal radius bones. An AO type C2 fracture was created and the fractures were plated according to each manufacturer's recommendations. The specimens then underwent cyclic and load-to-failure testing. An optical motion analysis system was used to detect displacement of fragments.

RESULTS

No significant differences were detected after cyclic loading as well as after load-to-failure testing, neither in regard to axial deformation, implant rigidity or maximum displacement. The fixed-angle single-row plate showed the highest pre-test rigidity, least increase in post-testing rigidity and highest load-to-failure rigidity and least radial shortening. The radial shortening of plates with two distal screw rows was 3.1 and 4.3 times higher, respectively, than that of the fixed-angle single-row plate.

CONCLUSION

The results of our study indicate that two distal screw rows do not add to construct rigidity and resistance against loss of reduction. Well conducted clinical studies based on the findings of biomechanical studies are necessary to determine the optimal number of screws necessary to achieve reproducibly good results in the treatment of distal radius fractures.

Volar long locking compression plate fixation for distal radius fractures with metaphyseal and diaphyseal extension

Comminuted distal radial fractures with metaphyseal and diaphyseal extension are uncommon and remain a challenge to treat. The purpose of this study was to assess the radiographic and functional outcomes of treatment with the volar long locking compression plate (LCP) system for distal radius fractures with metaphyseal and diaphyseal extension. This retrospective study was performed on 22 consecutive patients who were treated with open reduction and internal fixation with the application of a 2.4-mm-extra-long LCP volar distal radius plate. Patients were evaluated based on clinical signs and radiography studies. The average time to fracture union was 16 weeks. The volar tilt was restored to a mean of 10.1°. The radial length and radial inclination were restored to a mean of 12.8 mm and 23.6° at final follow-up, respectively. The mean loss of radial length was -1.0 mm at final follow-up as compared with the contralateral extremity. The average ulnar variance was positive 0.1 mm at final follow-up with a congruent distal radioulnar joint. The degree of collapse after fixation between immediate postoperative and final follow-up visit was -0.1 mm. Using the demerit-point system of the Gartland and Werley rating system, 14 results were rated as excellent, 5 as good and 1 as fair. DASH scores averaged 10.1 points. Based on our experience, the volar long LCP is useful in the management of comminuted fractures of the distal radius, in which there is proximal extension into the diaphysis and can avoid or minimize the complications of external fixation or dorsal bridging distraction plate.

Fragment-specific fixation for complex intra-articular fractures of the distal radius: results of a prospective single-centre trial

The goal was to evaluate the efficacy of 2.4 mm column-specific plating for intra-articular distal radius fractures. In total, 105 patients with AO type C distal radius fractures were operated on using the locking distal radius system, Synthes. Follow-up assessments including clinical (wrist and forearm range of motion, grip strength), radiological (articular step, radial length and inclination, volar tilt, and ulnar variance), and functional scores (Disabilities of the Arm, Shoulder, and Hand; Patient Rated Wrist Evaluation) were made at regular intervals until 1 year. Union was obtained in all patients. Articular surface was anatomically reconstructed in 74 patients (70.5%). Clinical and functional evaluation showed significant continuous improvements over the first year. C1 fractures had a better chance of anatomical reduction compared with C2 and C3 fractures. Fracture type, quality of reduction, and presence of degenerative changes did not show a significant effect on functional outcome scores. Column-specific fixation of the distal radius can achieve satisfactory results in complex intra-articular fractures.

Volar fixed-angle plating of distal radius fractures: screws versus pegs--a biomechanical study in a cadaveric model

OBJECTIVES

The purpose of this biomechanical study was to determine whether a multidirectional fixed-angle plate with locking screws or with locking pegs in the distal fragment would optimize fixation of Orthopaedic Trauma Association (OTA) type A3 distal radius fractures.

METHODS

Eight pairs of fresh-frozen human distal radii were used. Extra-articular distal radius fractures were created and stabilized with a multidirectional volar fixed-angle plate. The radii were randomized into 2 matched-paired groups. The distal fragment in Group I was stabilized with 7 locking screws. The distal fragment in Group II was fixed with 7 locking pegs. The proximal fragment in both groups was fixed with 3 screws. The specimens were tested under torsion and axial compression during static and cyclic tests. Finally, load-to-failure tests were performed under torsion.

RESULTS

After 1000 cycles, 99% of the median torsional stiffness remained in the group using screws, whereas only 76% of the median stiffness under torsion remained in the group using pegs (P = 0.018). Under axial compression, median stiffness remained at 93% in the group using screws after 1000 cycles compared with a median of 0% in the group using pegs (P = 0.018).

CONCLUSIONS

This biomechanical study showed a statistically significant difference between the locking screw and locking smooth peg configuration with regard to stiffness of the constructs after 1000 cycles. The use of locking screws as opposed to smooth locking pegs for OTA type A3 extra-articular distal radius fractures optimizes construct stability.

Optimal positioning of the DVR plate in distal radius fractures: a cadaveric examination of a referencing technique

INTRODUCTION

Volar locking plates have revolutionised the treatment of distal radius fractures but complications are not uncommon. We present a cadaveric study and a technical tip to assist in the accurate and reproducible placement of one such plate.

STUDY

We placed 25-g needles in the distal radioulnar joint and radiocarpal joint and measured the distance from these needles to a DVR plate in its optimal position. This distance measured 5mm, corresponding to the width of the depth gauge handle. Placing this next to needles in these joints can help pre-plan the most distal and ulnar extent of the plate allowing for reproducible optimal positioning of the DVR plate.

TECHNIQUE

The technique developed uses the existing kit and is simple and easy to build into one's existing fixation technique.