Biomechanics and biology of plate fixation of distal radius fractures

Enhanced Approaches to the Treatment of Distal Radius Fractures

Distal radius fractures are among the most common fractures treated by orthopedic surgeons. Various classification systems have been described which can help in deciding the approach for fixation. In some cases, a computed tomography scan can provide better understanding of the fracture fragments and displacement for surgical planning. Plating through the volar approach is the most common approach for fractures meeting operative criteria. Several additional approaches can be used for specific fracture patterns. These approaches can be used in isolation or in conjunction with other approaches to aid in visualization and fixation.

Biomechanics of Subcutaneous Locked Plating Versus Burke Plate and External Fixator for Comminuted Distal Radius Fractures

Background External fixators that span the wrist have been the historical norm in treating distal radius fractures. We have modified a dorsal distraction approach by using a subcutaneously applied locked bridge plate through two small incisions superficial to the extensor tendons and outside the extensor compartment. The purpose of this study was to biomechanically evaluate this modified method of fixation for comminuted distal radius fractures in comparison with two established constructs. Methods Matched cadaver specimens were used to model an AO Type 23-C3 distal radius fracture. Biochemical testing for stiffness during axial compressive loading was done on three constructs: a conventional Burke distraction plate, the subcutaneous internal fixation plating technique, and an external fixator. All specimens were cyclically loaded for 3000 cycles and then retested. Results The modified construct was found to be stiffer than the external fixator (p=0.013). When compared to the Burke plate, the modified construct was significantly less stiff before axial cycling (p=0.025). However, the difference was not maintained after cycling, and the post-axial loading stiffness difference was non-significant (p=0.456). Conclusion Our data demonstrate the biomechanical integrity of the subcutaneous plating technique for the fixation of comminuted distal radius fractures. It is stiffer than an external fixator and has the theoretical advantage of avoiding pin-tract infections. In addition, it is subcutaneous and not a cumbersome external construct. Our construct is minimally invasive, and it does not violate the dorsal extensor compartments. This allows for finger movement even while the construct is in place.

Effect of Time-To-Surgery on Distal Radius Fracture Outcomes: A Systematic Review

PURPOSE

It remains unclear whether time-to-surgery for distal radius fractures affects clinical, functional, or radiographic outcomes or health care costs/use. This systematic review investigated the outcomes of early versus delayed surgery for closed, isolated distal radius fractures in adult patients.

METHODS

A comprehensive search of MEDLINE, Embase, and CINAHL databases was completed for all original case series, observational studies, and randomized controlled trials reporting clinical outcomes of both early and delayed surgically-treated distal radius fractures from database inception to July 01, 2022. A consistent threshold of two weeks was used to define early versus delayed treatment arms.

RESULTS

Nine studies, including 16 intervention arms and 1,189 patients (858 early, 331 delayed), were included. Mean age was 58 years (range, 33-76). At more than one year, the frequency-weighted mean Disabilities of the Arm, Shoulder, and Hand score was 4 in the early group (n = 208; range, 1-17) and 21 in the delayed group (n = 181; range, 4-27). Range of motion, grip strength, and radiographic outcomes were comparable. The pooled mean complication rate (7% vs 5%) and revision rate (3.6% vs 1%) were very low in both groups.

CONCLUSIONS

A delay in time-to-surgery greater than two weeks for distal radius fractures may be associated with inferior patient-reported outcomes. Early surgery was associated with improved long-term Disabilities of the Arm, Shoulder, and Hand scores. On the basis of the available evidence, range of motion, grip strength, and radiographic outcomes are similar. The complication and revision rates were very low in both groups and comparable.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Impact of virtual embodiment and exercises on functional ability and range of motion in orthopedic rehabilitation

Recent evidence supports the use of immersive virtual reality (immersive VR) as a means of applying visual feedback techniques in neurorehabilitation. In this study, we investigated the benefits of an embodiment-based immersive VR training program for orthopedic upper limb rehabilitation, with the aim of improving the motor functional ability of the arm and accelerating the rehabilitation process in patients with a conservatively managed distal radius fracture. We designed a rehabilitation program based on developing ownership over a virtual arm and then exercising it in immersive VR. We carried out a between 3-group controlled trial with 54 patients (mean age = 61.80 ± 14.18): 20 patients were assigned to the experimental training group (immersive VR), 20 to the conventional digit mobilization (CDM) training control group, and 14 to a non-immersive (non-immersive VR) training control group. We found that functional recovery of the arm in the immersive VR group was correlated with the ownership and agency scores over the virtual arm. We also found larger range of joint movements and lower disability of the fractured arm compared with patients in the Non-immersive VR and CDM groups. Feeling embodied in a virtual body can be used as a rehabilitation tool to speed up and improve motor functional recovery of a fractured arm after the immobilization period.

Comparative study between fixed-angle and polyaxial screws in distal radius fixation with two volar locking plates

INTRODUCTION

When treating a distal radius fracture with a volar locking plate (VLP), numerous plate-screw designs are available. To date, there is not a screw fastening system with a clear superiority among the others.

HYPOTESIS

Fixed-angle screws are superior to polyaxial screws in distal radius VLP fixation with respect to screw protrusion and reduction preservation.

MATERIAL AND METHODS

A prospective cohort study based on eighty patients was performed. The first forty patients were treated by polyaxial VLP (PA group) were the next forty by a fixed-angle VLP (FA group). Fixation was performed by the flexor carpi radialis approach. Screws were placed 2mm shorter than actual measurement and intraoperative AP, lateral and tilt wrist views were done routinely. A computed tomography (CT) was conducted searching for screw protrusion. Loss of reduction was calculated from the difference between post-operative x-rays values and those at the 6-month follow-up. The total follow-up was 12 months with no losses.

RESULTS

Postoperative CT detected dorsal screw protrusion in 17 patients in PA group and 16 patients in FA group that intraoperative radiographs were assumed as correct (p=0.48). The mean invasion of dorsal cortex was of 2.2mm (1-7mm) for PA group and 2.6mm (1-5mm) for FA group (p=0.70). As from those protruding screws, the mean size was registered founding that fixed-angle screws had protrusions with shorter screws 20 vs. 22mm (p<0.05). Intraarticular screw protrusion was registered in 3 and 2 patients respectively (p>1.0). Experienced loss of reduction in volar tilt (p=0.42), radial inclination (p=0.75) and ulnar variance (p=0.83) were equivalent in both groups while a better preservation of the radial height in the PA group was observed (p<0.05).

DISCUSSIONS

In terms of screw protrusion rate, both fastening systems where similar. However, fixed-angle group invaded the dorsal cortex with shorter screws. Polyaxial screws were associated with a better preservation of the radial height. Finally, this study reinforces the idea that dorsal and articular screw protrusion is more frequent than we expected.

LEVEL OF EVIDENCE

II; therapeutic, prospective cohort study.

Determining the potential sites of neural adaptation to cross-education: implications for the cross-education of muscle strength

Cross-education describes the strength gain in the opposite, untrained limb following a unilateral strength training program. Since its discovery in 1894, several studies now confirm the existence of cross-education in contexts that involve voluntary dynamic contractions, eccentric contraction, electrical stimulation, whole-body vibration and, more recently, following mirror feedback training. Although many aspects of cross-education have been established, the mediating neural mechanisms remain unclear. Overall, the findings of this review show that the neural adaptations to cross-education of muscle strength most likely represent a continuum of change within the central nervous system that involves both structural and functional changes within cortical motor and non-motor regions. Such changes are likely to be the result of more subtle changes along the entire neuroaxis which include, increased corticospinal excitability, reduced cortical inhibition, reduced interhemispheric inhibition, changes in voluntary activation and new regions of cortical activation. However, there is a need to widen the breadth of research by employing several neurophysiological techniques (together) to better understand the potential mechanisms mediating cross-education. This fundamental step is required in order to better prescribe targeted and effective guidelines for the clinical practice of cross-education. There is a need to determine whether similar cortical responses also occur in clinical populations where, perhaps, the benefits of cross-education could be best observed.

Fragment-Specific Fixation for Fractures of the Distal Radius

This article summarizes the management of distal fractures utilizing Acumed fragment-specific family of plates. No single plate option can address every fracture pattern of the distal radius. These fragment-specific plates are usually adjuncts to allow the surgeon to expand the armamentarium in the management of complex volar and dorsal comminuted distal radius fracture patterns.

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.

Treatment strategy for distal radius fractures with ipsilateral arteriovenous shunts

PURPOSE

To describe our management of 3 patients with chronic renal failure who sustained distal radius fractures in limbs containing dialysis shunts.

METHODS

The 3 patients were 48-61 years old, and 2 of them were men. Because the injured limbs contained arteriovenous shunts, tourniquets were not used. Volar locking plate fixation was applied via the Henry approach. The patients' grip strength; visual analog scale scores; Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores; modified Mayo scores; and their range of wrist joint motion were assessed during the final follow-up examination. In addition, complications and the presence/absence of dysfunction of the forearm shunt were also investigated.

RESULTS

The mean duration of the postoperative follow-up period was 9 months (range, 7-10 mo), and the subjects' mean wrist motion values were 75°, 79°, 78°, and 87° during flexion, extension, pronation, and supination, respectively. Grip strength on the affected side as a percentage of that seen on the healthy side ranged from 71% to 90%. The patients' visual analog scale; QuickDASH; and modified Mayo scores were all excellent, and bone union was achieved in all 3 cases. No shunt dysfunction or skin soft tissue complications were noted.

CONCLUSIONS

Volar locking plate fixation via the Henry approach might be useful for treating distal radius fractures in cases in which an arteriovenous shunt is present in the same limb. Shunt dysfunction and hemorrhaging are of concern during open surgery, but these were not issues in our patients.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Fractures of the distal radius: postmanagement radiographic characterization

OBJECTIVE

The purpose of this article is to describe the management options available for the treatment of the distal radius fracture as well as potential associated complications.

CONCLUSION

There are a wide variety of currently accepted and used treatment options for fractures of the distal radius, ranging from closed reduction with casting to various forms of invasive surgical management. The radiologist must be familiar with these various forms of management to recognize complications when present on follow-up radiographs.

Preventing functional loss during immobilization after osteoporotic wrist fractures in elderly patients: a randomized clinical trial

BACKGROUND

Distal radius fractures are among the most common fractures and account for approximately one-sixth of all fractures diagnosed. Therapy results after distal radius fracture, especially of elderly patients, are often suboptimal. The inevitable immobilization for several weeks leads to reduction in range of motion, deterioration of muscle strength, malfunction of fine motor skills as well as changes of motor and sensory representations in the brain. Currently, there are no strategies to counteract these immobilization problems. The overall aim of the study is to investigate the therapeutic potential of motor-cognitive approaches (mental practice or mirror therapy) on hand function after wrist fracture.

METHODS/DESIGN

This study is a controlled, randomized, longitudinal intervention study with three intervention groups. One experimental group imagines movements of the fractured upper extremity without executing them (mental practice). The second experimental group receives a mirror therapy program consisting of the performance of functional movement synergies using the unaffected forearm, wrist, and hand. The control group completes a relaxation training regime. Additionally, all patients receive usual care by the general practitioner. We include women aged 60 years and older having a distal radius fracture and sufficient cognitive function. All groups are visited at home for therapy sessions 5 times per week for the first 3 weeks and 3 times per week for weeks 4 to 6. Measurements are taken at therapy onset, and after 3, 6 and 12 weeks. The primary outcome measure will assess upper extremity functioning (Patient-Rated Wrist Evaluation [PRWE]), while secondary outcome measures cover subjective wrist function (Disabilities of the Arm and Shoulder; [DASH], objective impairment (range of motion, grip force) and quality of life (EuroQol-5D, [EQ5D]).

DISCUSSION

Results from this trial will contribute to the evidence on motor-cognitive approaches in the early therapy of distal radius fractures.

TRIAL REGISTRATION

The trial is registered at ClinicalTrials.gov with registration number NCT01394809 and was granted permission by the Medical Ethical Review Committee of the University of Tübingen in June 2011.

Distal radius fractures and the volar lunate facet fragment: Kirschner wire fixation in addition to volar-locked plating

BACKGROUND

The volar lunate facet fragment of a distal radius fracture may not be stabilized with volar-locked plating alone due to the small size and distal location of the fragment. Identification and stabilization of this small fragment is critical as unstable fixation may result in radiocarpal and radioulnar joint subluxation. The addition of spring wire fixation with volar plating can provide stable internal fixation of this critical fracture fragment.

METHODS

A retrospective review (2006-2011) identified nine patients with distal radius fractures with an associated volar lunate facet fragment that were treated with volar-locked plating and spring wire fixation of the volar lunate facet fragment. Radiographic indices, range of motion, grip strength, and postoperative Patient-related wrist evaluation (PRWE) scores were obtained to assess pain and function.

RESULTS

All distal radius fractures healed, and the volar lunate facet fragment reduction was maintained. The mean follow-up was 54 weeks. Mean active range of motion was 46° wrist flexion, 51° wrist extension, 80° pronation, and 68° supination. The mean grip strength was 21 Kg, achieving 66 % of the uninjured limb. The average PRWE score was 17. No patient required removal of hardware or had evidence of tendon irritation.

CONCLUSIONS

The addition of spring wire fixation to volar-locked plating provided stable fixation of the volar lunate facet fragment of distal radius fractures without complication. This technique addresses a limitation of volar-locked plating to control the small volar lunate facet fragment in distal radius fractures otherwise amenable to volar plating.

LEVEL OF EVIDENCE

A retrospective case series, Level IV.

Effect of early administration of alendronate after surgery for distal radial fragility fracture on radiological fracture healing time

This multicentre prospective clinical trial aimed to determine whether early administration of alendronate (ALN) delays fracture healing after surgical treatment of fractures of the distal radius. The study population comprised 80 patients (four men and 76 women) with a mean age of 70 years (52 to 86) with acute fragility fractures of the distal radius requiring open reduction and internal fixation with a volar locking plate and screws. Two groups of 40 patients each were randomly allocated either to receive once weekly oral ALN administration (35 mg) within a few days after surgery and continued for six months, or oral ALN administration delayed until four months after surgery. Postero-anterior and lateral radiographs of the affected wrist were taken monthly for six months after surgery. No differences between groups was observed with regard to gender (p = 1.0), age (p = 0.916), fracture classification (p = 0.274) or bone mineral density measured at the spine (p = 0.714). The radiographs were assessed by three independent assessors. There were no significant differences in the mean time to complete cortical bridging observed between the ALN group (3.5 months (SE 0.16)) and the no-ALN group (3.1 months (SE 0.15)) (p = 0.068). All the fractures healed in the both groups by the last follow-up. Improvement of the Quick-Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, grip strength, wrist range of movement, and tenderness over the fracture site did not differ between the groups over the six-month period. Based on our results, early administration of ALN after surgery for distal radius fracture did not appear to delay fracture healing times either radiologically or clinically.

FLEXOR POLLICIS LONGUS TENDON ENTRAPMENT AFTER PERFORMING MINIMALLY INVASIVE PLATE OSTEOSYNTHESIS OF A DISTAL RADIUS FRACTURE: A CASE REPORT

In this study, we report a case of a 60-year-old woman with diabetes mellitus, who had a left distal radius fracture and could not flex the interphalangeal joint of her left thumb after we performed an open reduction and internal fixation procedure using minimally invasive plate osteosynthesis. Nine days after the first operation, we explored her wrist. We observed that the flexor pollicis longus tendon was compressed by the inserted plate. Then revision surgery and tendon repair were performed. Three months later, the fracture was healed and flexor pollicis longus function recovered well without sequelae. Approach through the interval between flexor carpi radialis and radial artery is preferred to prevent tendon entrapement.

Volar versus dorsal latest-generation variable-angle locking plates for the fixation of AO type 23C 2.1 distal radius fractures: a biomechanical study in cadavers

INTRODUCTION

Anatomicaly preformed variable-angle locking plates are technologically mature and appear to be optimal for the fixation of distal radius fractures. However, there is still much argument about whether volar plating is equivalent to dorsal (buttressing) plating, especially in the management of intra-articular extension fractures. This biomechanical study was performed to determine, in a simple intra-articular fracture model, whether dorsal or volar plate constructs would be more stable.

MATERIALS AND METHODS

Six pairs of fresh frozen radii were examined with dual-energy absorptiometry (DXA) to determine their bone mineral density (BMD). An AO type 23 C2.1 fracture was created. Volar fixation was with a 2.4mm Variable-Angle LCP Two-Column Volar Distal Radius Plate; dorsal fixation was with two orthogonal 2.4 mm Variable-Angle LCP Dorsal Distal Radius Plates (both devices: Synthes, Oberdorf, Switzerland). Biomechanical testing used a proven protocol involving static tests of stiffness, and a cyclic test to obtain range of motion (ROM), maximum deformation, and subsidence data.

RESULTS

None of the constructs failed during biomechanical testing. The two groups (volar and dorsal plating, respectively) did not differ significantly in terms of initial (pre-cyclic-testing) and final (post-cyclic-testing) stiffness. Equally, there was no significant difference between the subsidence values in the two groups. The post-cyclic-testing ROM was significantly greater in the dorsal-plate group as compared with the volar-plate group. The volar constructs showed a significant decrease in the ROM between pre- and post-cyclic testing.

CONCLUSION

Biomechanically, volar plating with a modern variable-angle locking plate is equivalent to dorsal plating with two modern variable-angle locking plates.

Outcomes of pin and plaster versus locking plate in distal radius intraarticular fractures

Background

Distal radius fractures are among the most prevalent fractures predictive of probable occurrence of other osteoporotic fractures. They are treated via a variety of methods, but the best treatment has not been defined yet.

Objectives

This study was performed to compare the results of open reduction and internal fixation with locking plates versus the pin and plaster method.

Materials and Methods

In this prospective study, 114 patients aged 40 to 60 years with Fernandez type III fracture referring to Imam-Reza and Mehr hospitals of Mashhad from 2009 to 2011, were selected randomly; after obtaining informed consent, they were treated with pin and plaster fixation (n = 57) or internal fixation with the volar locking plate (n = 57). They were compared at the one year follow up. Demographic features and standard radiographic indices were recorded and MAYO, DASH and SF - 36 tests were performed. Data was analyzed by SPSS software version 13, with descriptive indices, Mann-Whitney and Chi-square tests.

Results

SF-36 test demonstrated a better general health (P < 0.001), mental health (P = 0.006), physical functioning (P < 0.001), social functioning (P < 0.001) and energy/fatigue (P < 0.001) in LCP group. However, pain (P = 0.647) was not significantly different between the groups. Physical limitation (P < 0.001) and emotional limitation (P < 0.001) were greater in the pin and plaster group. Also, in the LCP group mean MAYO score (P < 0.001) was more than pin and plaster group. Mean DASH score was not different between the groups (P = 0.218). The rate of acceptable results of radiographic indices (P < 0.001), grip strength (P < 0.001) and range of motion in supination-pronation (P < 0.001) in LCP method were better than the pin and plaster method.

Conclusions

In treatment of intra-articular distal radius fractures in middle-aged patients internal fixation with locking plates may be prefered to pin and plaster as the treatment of choice.

Prospective continuous study comparing intrafocal cross-pinning HK2(®) with a locking plate in distal radius fracture fixation

The fixation of distal radius fractures by pinning or locking plates remains controversial. The aim of this prospective continuous study was to compare the results of 28 anterior locking plates with 23 intrafocal cross-pinning HK2(®) systems. The mean age of group I (SVP(®), SBI™ plate) was 61 years. There were 15 extra-articular and 13 articular fractures. The mean age of group II (HK2(®), Arex™) was 63 years, with 13 extra-articular and 10 articular fractures. Twelve clinical variables were measured: pain, wrist strength, supination strength, pronation strength, quick DASH score, range of wrist motion in flexion, extension, pronation, and supination, ulnar variance, radial slope, and radial volar tilt. At 40 weeks follow-up, there was no difference between the two groups for 10 variables; two variables showed differences between the two groups: mean quick DASH score was 10.7 for group I, 19.7 for group II, and mean ulnar variance was -0.95 mm for group I, and 1.16 mm for group II. Six transient complications were noted for group I: five tenosynovitis, and one carpal tunnel syndrome. We noted 12 complications in group II: four superficial infections, two secondary displacements, one pin migration, two CRPS type II, two tendon ruptures and one nerve irritation. Generally, plates provided a more stable fixation associated with less complications while the HK2(®) system was quicker and less costly. The indications for its use need to be refined with a larger series and longer follow-up.

Outcome of dorsally comminuted versus intact distal radial fracture fixed with volar locking plates

OBJECTIVE

Distal radial fractures are common. Modern trends favour operative treatment in many instances, providing stable fixation and early functional recovery. Recent biomechanical evidence suggests that volar locking plates (VLPs) enable adequate stability for dorsally displaced fractures, both in dorsally intact (DI) and in dorsally comminuted (DC) fractures. The aim of the study was to compare the clinical outcome of these two fracture groups treated with a VLP.

METHODS

Retrospective case-control analysis of 91 distal radial fractures treated surgically using VLP by a single surgeon between the years 2006 and 2008 was carried out. Fractures were classified according to the Arbeitsgemeinschaft für Osteosynthes/Orthopaedic Trauma Association (AO/OTA) classification. Based on initial pre-reduction X-rays and computed tomography (CT) scans, fractures were classified into two groups of DI and DC fractures. The patients were re-evaluated at 2 and 6 weeks, 3 and 6 months and 1 year.

RESULTS

Forty-one fractures (45%) were dorsally comminuted. Patients in the DC group were significantly older (mean 59 vs. 46 years, p<0.01) and included more female patients, as well as significantly more C3 type fractures than the DI group (p<0.04). The mean Disabilities of the Arm, Shoulder and Hand (DASH) score at 1 year postoperatively was 6.3±2.3 for the DC group, as compared with 6.6±2.02 for the DI group (p=0.64). Average time to return to work was longer in the DC group (81.2 vs. 63.6 days, p=0.05). Range of motion, volar tilt, and radial inclination were within clinically acceptable values and did not differ significantly among the two groups.

CONCLUSIONS

VLP fixation of DC distal radial fractures results in the maintenance of reduction and comparable functional and radiographical outcome with respect to DI fractures.

Should unstable extra-articular distal radial fractures be treated with fixed-angle volar-locked plates or percutaneous Kirschner wires? A prospective randomised controlled trial

Fractures of the distal radius are commonly treated with cast immobilisation; however, those potentially unstable injuries with dorsal comminution may need operative intervention. This intervention is usually with manipulation and Kirschner wires but advances in locking-plate technology have enabled surgeons to achieve anatomical reconstruction of complex fracture patterns, even in poor-quality osteoporotic bone.To ascertain if fixed-angle volar-locked plates confer a significant benefit over manipulation and Kirschner-wire stabilisation, we prospectively randomised 56 adult patients with isolated, closed,unilateral, unstable extra-articular fractures into two treatment groups, one fixed with K-wires and the other fixed with a volar locking plate.Functional outcomes were assessed using Gartland and Werley and Disabilities of the Arm, Shoulder and Hand (DASH) scores. These were statistically better in the plate group at 3 and 6 months.Radiological assessment showed statistically better results at 6 weeks, 3 months and 6 months, postoperatively.In the plate group, there was no significant loss of fracture reduction.

Efficacy of radial styloid targeting screws in volar plate fixation of intra-articular distal radial fractures: a biomechanical study in a cadaver fracture model

Background

The locking screws target the radial styloid, theoretically provide greater stability against radial styloid fragment. However, it is unknown whether the radial styloid locking screws increased the stability of the volar plating system fixation along the entire distal radius or not. In this study, we evaluated the stability of the volar plating system fixation with or without the radial styloid screws using a biomechanical study in a cadaver fracture model.

Methods

Six matched pairs of fresh-frozen human cadaver wrists complete from the proximal forearm to the metacarpal bones were prepared to simulate standardized 3-part intra-articular and severe comminuted fractures. Specimens were fixed using the volar plating system with or without 2 radial styloid screws. Each specimen was loaded at a constant rate of 20 mm/min to failure. Load data was recorded and, ultimate strength and change in gap between distal and proximal fragments were measured. Data for ultimate strength and screw failure after failure loading were compared between the 2 groups.

Results

The average ultimate strength at failure of the volar plate fixation with radial styloid screws (913.5 ± 157.1 N) was significantly higher than that without them (682.2 ± 118.6 N). After failure loading, the average change in gap between the ulnar and proximal fragment was greater than that between the radial and proximal fragment. The number of bent or broken screws in ulnar fragment was higher than that in radial fragment. The number of specimens with bent or broken screws in cases with radial styloid screws was fewer than that in the fixation without radial styloid screws group.

Conclusion

The ulnar fragment is more intensively stressed than the radial fragment under axial loading of distal radius at full wrist extension. The radial styloid screws were effective in stable volar plate fixation of distal radial fractures.

Failure of volar locking plate fixation of an extraarticular distal radius fracture: A case report

BACKGROUND

Volar locking plates provide significant structural stability to the distal radius. Failure of a volar locked plating is a rarely reported complication in the literature.

CASE PRESENTATION

A 40 year-old, obese female patient who presented with a displaced extraarticular distal radius fracture, underwent open reduction and internal fixation of the fracture using a volar locking plate. Radiographs taken at 10 weeks postoperatively showed failure of fixation with breakage of the four distal locking screws. A hardware removal was performed at 6 months, and the patient was then lost to follow-up. She presented again at 18 months after the first surgery, with significant pain, and radiographic signs of a radial collapse and a fracture-nonunion. A total wrist fusion was performed as the method of choice at that point in time.

CONCLUSION

Volar locked plating represents the new "gold standard" of distal radius fracture fixation. However, despite the stability provided by locking plates, hardware failure may occur and lead to a cascade of complications which will ultimately require a wrist fusion, as outlined in this case report. Additional structural support by bone grafting may be needed in selected cases of volar locked plating, particularly in patients with a high risk of developing a fracture-nonunion.

Biomechanical comparison of double-row locking plates versus single- and double-row non-locking plates in a comminuted metacarpal fracture model

PURPOSE

Open or unstable metacarpal fractures frequently require open reduction and internal fixation. Locking plate technology has improved fixation of unstable fractures in certain settings. In this study, we hypothesized that there would be a difference in strength of fixation using double-row locking plates compared with single- and double-row non-locking plates in comminuted metacarpal fractures.

METHODS

We tested our hypothesis in a gap metacarpal fracture model simulating comminution using fourth-generation, biomechanical testing-grade composite sawbones. The metacarpals were divided into 6 groups of 15 bones each. Groups 1 and 4 were plated with a standard 6-hole, 2.3-mm plate in AO fashion. Groups 2 and 5 were plated with a 6-hole double-row 3-dimensional non-locking plate with bicortical screws aimed for convergence. Groups 3 and 6 were plated with a 6-hole double-row 3-dimensional locking plate with unicortical screws. The plated metacarpals were then tested to failure against cantilever apex dorsal bending (groups 1-3) and torsion (groups 4-6).

RESULTS

The loads to failure in groups 1 to 3 were 198 +/- 18, 223 +/- 29, and 203 +/- 19 N, respectively. The torques to failure in groups 4 to 6 were 2,033 +/- 155, 3,190 +/- 235, and 3,161 +/- 268 N mm, respectively. Group 2 had the highest load to failure, whereas groups 5 and 6 shared the highest torques to failure (p < .05). Locking and non-locking double-row plates had equivalent bending and torsional stiffness, significantly higher than observed for the single-row non-locking plate. No other statistical differences were noted between groups.

CONCLUSIONS

When subjected to the physiologically relevant forces of apex dorsal bending and torsion in a comminuted metacarpal fracture model, double-row 3-dimensional non-locking plates provided superior stability in bending and equivalent stability in torsion compared with double-row 3-dimensional locking plates, whereas single-row non-locking plates provided the least stability.

A comparative study of fragment-specific versus volar plate fixation of distal radius fractures

BACKGROUND

There are many plating systems available for treating distal radius fractures, and deciding which to use can be difficult. This prospective cohort study compared outcomes of two commonly used fixation systems: fragment-specific fixation and a fixed-angle volar locking plate system.

METHODS

Consecutive distal radius fractures were prospectively evaluated in a fragment-specific fixation cohort and a volar locking plate system cohort. Radiographic, functional, and patient-rated outcomes were collected immediately postoperatively and at 6 and 12 months postoperatively. Complications were recorded and graded by severity.

RESULTS

Fourteen distal radius fractures treated with fragment-specific fixation and 85 treated with the volar locking plate system were enrolled. Radial inclination was similar in both cohorts (23 degrees versus 25 degrees); however, volar tilt was worse in the fragment-specific fixation cohort (-10 degrees versus 10 degrees, p < 0.05). The majority (63 percent) of the fragment-specific fixation cohort demonstrated a loss of relative radial length. Grip strength, pinch strength, Michigan Hand Outcomes Questionnaire scores, and most range of motion measurements were superior in the volar locking plate system cohort at 6 months, although not all differences were statistically significant. By 12 months the differences in functional and patient-rated outcomes were smaller, suggesting that the fragment-specific fixation cohort tended to reach the outcomes of the volar locking plate system cohort over time. Complications requiring reoperation were higher in the fragment-specific fixation cohort (p < 0.05).

CONCLUSIONS

The volar locking plate system results in more stable fixation and better objective and subjective outcomes early in the postoperative period. It has fewer complications requiring reoperation than fragment-specific fixation.

Does a volar locking plate provide equivalent stability as a dorsal nonlocking plate in a dorsally comminuted distal radius fracture?: a biomechanical study

OBJECTIVES

The purpose of this study was to compare the fixation afforded by a dorsal nonlocking plate with a volar locking plate in a fracture model simulating an extra-articular distal radius fracture with dorsal comminution (OTA [Orthopaedic Trauma Association] type 23-A3.2).

METHODS

In 10 matched pairs of fresh-frozen cadaveric arms, a comminuted extra-articular dorsally unstable distal radius fracture (OTA type 23-A3.2) was created. The fractures were fixed with either dorsally placed nonlocking T-plate or volarly placed locking plate within matched pairs. The precycling stiffness with axial and torsional loading of the specimens was determined. The specimens were then loaded axially for 5000 cycles, and postcycling axial and torsional stiffness and load to failure were determined.

RESULTS

The mean axial and torsional stiffness before and after cyclic loading of fractures stabilized with dorsal nonlocking plate was not significantly different than fractures fixed with volar locking plate. Although the mean load to failure was greater for the volar locking plate group than dorsal nonlocking plate group, the difference was not significant.

CONCLUSIONS

This study suggests that the fixation obtained with volar locking plates is as stable as fixation with a dorsal plate in acute healing period and can withstand the functional demands of the immediate postoperative period in dorsally comminuted unstable extra-articular distal radius fractures. Elimination of dorsal tendinopathy by using volar locking plates may lead to fewer long-term complications. Locking plates provided better stability in specimens with osteoporosis.

A representative case of osteoporotic distal radius fracture

We present a case with nonsimultaneous bilateral dorsally displaced unstable osteoporotic distal radius fractures treated by open reduction and internal fixation using a volar and dorsal locking-plate system in a 69-year-old man. On the left side the patient had a loss of reduction as a result of plate bending 1 week after palmar plating. Correction of the dorsopalmar tilt was achieved through additional dorsal plating. Three months later the same patient sustained a distal radius fracture on his right forearm. Open anatomic reduction could only be achieved using palmar and dorsal locking plates, and the large metaphyseal defect was filled with resorbable bone substitute. Six weeks after surgery the patient reported persisting wrist pain. The x-rays showed loss of reduction. Because of flexor tendon irritation, the plate had to be removed after healing malunited. At the final follow-up at 18 months, the patient showed good subjective results according to the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire results. Active wrist motion was 60 degrees extension on the left and 55 degrees extension on the right. The active range of flexion was 50 degrees for left and right wrist, and active pronation and supination were unrestricted for both forearms. Grip strength was 50 kg on either side. Although recently good and excellent results have been reported treating distal radius fractures using volar locking plates in elderly individuals, we believe these implants still have their limits depending on local bone quality and fracture pattern. Decisionmaking for surgery versus conservative treatment should balance the risks and advantages for each patient accurately.

Innovations in osteosynthesis and fracture care

Over the years giant steps have been made in the evolution of fracture fixation and the overall clinical care of patients. Better understanding of the physiological response to injury, bone biology, biomechanics and implants has led to early mobilisation of patients. A significant reduction in complications during the pre-operative and post-operative phases has also been observed, producing better functional results. A number of innovations have contributed to these improved outcomes and this article reports on the advances made in osteosynthesis and fracture care.

Treatment of intra-articular fractures of the distal radius

In a randomised prospective study, 20 patients with intra-articular fractures of the distal radius underwent arthroscopically- and fluoroscopically-assisted reduction and external fixation plus percutaneous pinning. Another group of 20 patients with the same fracture characteristics underwent fluoroscopically-assisted reduction alone and external fixation plus percutaneous pinning. The patients were evaluated clinically and radiologically at follow-up of 24 months. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and modified Mayo wrist score were used at 3, 9, 12 and 24 months postoperatively. In the arthroscopically- and fluoroscopically-assisted group, triangular fibrocartilage complex tears were found in 12 patients (60%), complete or incomplete scapholunate ligament tears in nine (45%), and lunotriquetral ligament tears in four (20%). They were treated either arthroscopically or by open operation. Patients who underwent arthroscopically- and fluoroscopically-assisted treatment had significantly better supination, extension and flexion at all time points than those who had fluoroscopically-assisted surgery. The mean DASH scores were similar for both groups at 24 months, whereas the difference in the mean modified Mayo wrist scores remained statistically significant.

Although the groups are small, it is clear that the addition of arthroscopy to the fluoroscopically-assisted treatment of intra-articular distal radius fractures improves the outcome. Better treatment of associated intra-articular injuries might also have been a reason for the improved outcome.

Fragment-specific fracture fixation and double-column plating of unstable distal radial fractures using AO mini-fragment implants and Kirschner wires

OBJECTIVE

To evaluate the efficacy of AO mini-fragment implants and 1.25-mm Kirschner wires using fragment-specific fracture fixation and double-column plating for displaced or unstable distal radial fractures.

DESIGN

prospective and consecutive.

SETTING

level II trauma hospital.

PARTICIPANTS

28 people with 30 fractures and an average follow-up of 21.1 (range 12-41) months, treated with fragment-specific fracture fixation.

OUTCOME MEASUREMENTS

anatomical assessment using anteroposterior and lateral radiographs, graded according to Sarmiento's modification of Lidstrom's scoring system. CLINICAL OUTCOME ASSESSMENT: DASH and Modified Gartland and Werley scores.

RESULTS

There were 24 excellent and 6 good radiological results. Final mean grip strength was 83% of uninjured side, and mean wrist range of motion was 61 degrees dorsiflexion, 54 degrees palmar flexion, 85 degrees supination and 83 degrees pronation. Gartland and Werley's demerit point system revealed 13 (43%) excellent, 12 (40%) good, 5 (17%) fair and no poor results. The mean DASH score was 18, with a standard deviation of +/-18.

CONCLUSION

This fixation method is a reliable and low-cost alternative with good clinical and anatomical results, particularly useful in open reduction and internal fixation of comminuted intra-articular distal radial fractures.

Locking plate technology and its applications in upper extremity fracture care

Locking plate technology has been a major advance in fracture care. These plates afford a stronger construct and have been useful in cases where the bone is osteoporotic and unicortical fixation or distal periarticular fracture fixation is necessary. Disadvantages include fixed angle screw fixation and inability to compress at the fracture site; however, the use of a combination of compression and locking screws allows for both fracture compression with cortical screws and stronger fixation with locking screws. Future studies will refine the indications and overall efficacy in the use of this technology.

The outcome of intra-articular distal radius fractures treated with fragment-specific fixation

PURPOSE

To assess the clinical, radiographic, and functional outcome of treating intra-articular distal radius fractures with fragment-specific fixation.

METHODS

A retrospective review of 81 patients with 85 intra-articular distal radius fractures who were treated with fragment-specific fixation was performed. Minimum time to follow-up evaluation was 1 year, with a mean time of 32 months. The immediate postoperative films were compared with those taken at the final follow-up evaluation. Radiographs of the uninjured wrist were also obtained at the final follow-up evaluation for comparison. Patients were examined for wrist and finger range of motion, deformity, and grip strength, and they completed a standard Disabilities of the Arm, Shoulder, and Hand outcome survey.

RESULTS

According to Gartland and Werley scoring there were 61 excellent and 24 good results. Flexion and extension of the surgically treated wrist at the final follow-up evaluation averaged 85% and 91%, respectively, of the uninjured wrist; grip strength averaged 92% compared with the uninjured side. The average Disabilities of the Arm, Shoulder, and Hand outcome score for the injured wrist was 9. Sixty-two percent of patients achieved a 100 degrees arc of flexion and extension and normal forearm rotation by postoperative week 6. Radiographic alignment was maintained between immediate postoperative and final follow-up films, and there were no cases of symptomatic arthritis at the final follow-up evaluation.

CONCLUSIONS

Fragment-specific fixation is a reasonable alternative for treating intra-articular fractures of the distal radius. At final follow-up evaluations, patients had good to excellent results with respect to range of motion, grip strength, radiographic alignment, and satisfaction scores. Stable fixation allowed starting active and passive motion of the wrist without compromising postoperative alignment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.