Unstable Extra-articular Distal Radius Fractures Research Articles

Comparison of five percutaneous pinning methods for unstable extra-articular distal radius fractures: A mechanical study using sawbones.

Objectives This study aims to mechanically compare five different extra-focal bi-cortical pin configurations (using two and three pins) employed for fixation of a simulated unstable extra-articular distal radius fracture with dorsal comminution using a sawbone model.Materials and methods This in vitro mechanical study was conducted between June 2019 and July 2019. A standard fracture model (Arbeitsgemeinschaft für Osteosynthesefragen [AO] type 23-A3.3) was created using a fourth generation composite artificial radius bone. Five groups with two- and three-pin configurations were tested under axial, volar, and dorsal loading with a universal test device. Mean stiffness values were compared statistically.Results Comparison of stiffness values from axial and volar loading tests between groups in paired comparison showed no statistically significant difference (p=0.194 and p=0.086, respectively). Dorsal loading tests showed statistically significant difference between the groups in pairwise comparison (p=0.002). Three-pin groups (Groups 3, 4, and 5) had higher stiffness values compared to two-pin groups (Groups 1 and 2) in dorsal loading tests (p=0.001). Three-pin configuration test groups with two divergent or convergent pins from the radial styloid performed better compared to both two-pin groups (p=0.01, p=0.002) in dorsal loading tests.Conclusion Our data demonstrated that the three-pin configuration with two divergent or convergent Kirschner wires from the styloid and a third wire from the dorsal/ulnar cortex had higher stiffness values compared to two-pin configurations in dorsal loading tests. When indicated, we suggest the use of a three-pin construct. Particularly in cases with a risk of volar angulation, we recommend a three-pin configuration with two divergent or convergent bi-cortical Kirschner wires.

Percutaneous Threaded Pin Fixation of Distal Radius Fracture in the Athlete.

The purpose of this study was to examine the outcomes and return to play with early rehabilitation in athletes who sustained unstable extra-articular distal radius fractures treated with a purpose-designed threaded pin technique. This prospective study examined athletes with displaced and unstable distal radius fractures treated surgically with purpose-designed threaded pins. Patients were enrolled in an early rehabilitation protocol, with formal therapy initiated on postoperative days 1 to 3. Range of motion and strength measurements were documented throughout the postoperative period, noting the time until return to athletic competition. These results were compared with historical values using other forms of fixation. Nineteen athletes, average age of 35 years, were treated with threaded pin technique with early rehabilitation; all had complete healing and maintained alignment based on radiographic evaluation. The average time span between surgery and release to competition was 8 weeks, with all but 1 patient returning to sport within 12 weeks of injury. Average postoperative flexion measured 58°, extension was 57°, pronation was 81°, and supination was 74°. JAMAR grip strength in position 3 measured 25.22 kg, which equated to 73% of the uninjured side's grip strength at the time of release to play. Surgical fixation using a purpose-designed threaded pin is a useful alternative to volar plating for isolated radial styloid and extra-articular distal radius fractures in athletes. The purpose-designed threaded pin may afford athletes rapid recovery during the early postoperative period, preserving strength and dexterity and minimizing time lost before return to play.

Minimally invasive internal fixation for extra-articular distal radius fracture: Comparison between volar plate and intramedullary nail

IntroductionThere are numerous internal fixation techniques for distal radius fracture, using pins, plates or nails. Some authors have developed minimally invasive procedures. The aim of the present study was to compare two minimally invasive internal fixation techniques for unstable extra-articular distal radius fracture in women over 50 years of age: volar plate (minimally invasive plate osteosynthesis: MIPO), and intramedullary nail. HypothesesThe main study hypothesis was that the incision scar left by minimally invasive internal fixation is smaller using MIPO than an intramedullary nail. The secondary hypotheses were that the two techniques do not differ in terms of pain, functional score, strength, range of motion and radiologic indices. Material and methodThe series comprised nineteen A2.2 and one A2.1 fractures in 20 female patients with a mean age of 72 years. The first 10 (group 1) received minimally invasive internal fixation of the distal radius by MIPO, and the other 10 (group 2) by intramedullary nail locked onto the distal radius epiphysis and diaphysis. ResultsThe main study hypothesis was confirmed: the incision scar left by minimally invasive internal fixation was smaller using MIPO than an intramedullary nail (mean, 14.3mm vs. 32.8mm). Some of the secondary hypotheses were also confirmed: there were no differences between the two techniques in terms of pain at 6 months, QuickDASH, PRWE (Patient-Reported Wrist Evaluation), range of motion or ulnar variance; two were not confirmed: pain at 6 weeks was less with intramedullary nails, and palmar slope was better with MIPO. Discussion and conclusionThe main study hypothesis was confirmed: the incision scar left by minimally invasive internal fixation was smaller using MIPO than an intramedullary nail. In conclusion, the present findings showed that internal fixation of unstable extra-articular fracture in over 50-year-olds gave better clinical results at 6 weeks using an intramedullary nail, while MIPO required smaller incision. Level of evidenceIII, retrospective study.

Cannulated Self-Drilling, Self-Tapping Pins for Displaced Extra-articular Distal Radius Fractures.

Displaced unstable extra-articular radius fractures are common and frequently treated with open reduction and internal fixation with a fixed-angle volar plate. Although this treatment yields good results, it might be more invasive than necessary for management of this often relatively simple fracture. In this article, we present the technique of using a cannulated self-drilling, self-tapping (CSDT) construct that can be employed in a minimally invasive fashion. The CSDT offers a minimally invasive alternative to volar fixed-angle plating for unstable extra-articular distal radius fractures. It also can be useful in isolated displaced radial styloid fractures. Placed appropriately, implants rarely have to be removed. The CSDT also allows for early motion and rapid return to activities with anticipated satisfactory range of motion andfunction.

Functional and Anatomical Outcome of Unstable Extra-Articular Distal Radius Fracture Managed with Plaster Immobilization and with External Fixation

Functional and Anatomical Outcome of Unstable Extra-Articular Distal Radius Fracture Managed with Plaster Immobilization and with External Fixation

Volar, Intramedullary, and Percutaneous Fixation of Distal Radius Fractures.

Background The management of extra-articular distal radius fractures is highly variable, with no clear consensus regarding their optimal management. Purpose To assess comparatively the biomechanical stability of Kirschner wire (K-wire) fixation, volar plating, and intramedullary nailing for unstable, extra-articular distal radius fractures with both (1) constant and (2) cyclical axial compression, simulating forces experienced during early postoperative rehabilitation. Methods Twenty-six volar locking plate, intramedullary nail, and K-wire bone-implant constructs were biomechanically assessed using an unstable extra-articular distal radius bone model. Bone implant models were created for each type of construct. Three samples from each construct underwent compressive axial loading until fixation failure. The remaining samples from each construct underwent fatigue testing with a 50-N force for 2,000 cycles followed by repeat compressive axial loading until fixation failure. Results Axial loading revealed the volar plate was significantly stiffer than the intramedullary nail and K-wire constructs. Both the volar plate and intramedullary nail required greater than 300 N of force for fixation failure, while the K-wire construct failed at less than 150 N. Both the volar plate and intramedullary nail demonstrated less than 1 mm of displacement during cyclic loading, while the K-wire construct displaced greater than 3 mm. Postfatigue testing demonstrated the volar plate was stiffer than the intramedullary nail and K-wire constructs, and both the volar plate and intramedullary nail required greater than 300 N of force for fixation failure while the K-wire construct failed at less than 150 N. Conclusions Volar plating of unstable extra-articular distal radius fractures is biomechanically stiffer than K-wire and intramedullary fixation. Both the volar plate and intramedullary nail demonstrated the necessary stability and stiffness to maintain anatomic reduction during the postoperative rehabilitation period. Clinical Relevance Both the volar plate and intramedullary nail demonstrated the necessary biomechanical stability to maintain postoperative reduction in extra-articular distal radius fractures, warranting further clinical comparison.

Intramedullary repair device against volar plating in the reconstruction of extra-articular and simple articular distal radius fractures; a randomized pilot study.

This prospective randomized pilot study reports our institutional experience and early results using Sonoma Wrx (Sonoma Orthopedic Products, Santa Rosa, CA) in the treatment of extra-articular and simple intra-articular distal radius fractures. A total of 64 patients, were enrolled in the study. They were considered eligible if they had; unstable extra-articular distal radius fractures and simple intra-articular distal radius fractures suitable for closed reduction (AO types; A2.2, A2.3, A3.1 C2.1, C2.2). Patients in group I received intramedullary fixation using the Sonoma Wrx device and patients in group II received standard volar locking plate fixation. Radiographic criteria of acceptable healing were used for evaluation. Two groups were similar in terms of baseline characteristics. Mean time of operation was significantly shorter in Group 1 vs. in group 2 (36.81 ± 7.11 vs. 48.97 ± 5.9 minutes, p = 0.001). Time to healing of the fracture was not different between two groups (5.45 ± 1.09 vs. 5.70 ± 1.04 weeks for Group 1 vs. 2, respectively p = 0.36). Overall complications occurred in 9 patients in group 1 and in 15 patients in group 2 (p = 0.17). Follow-up was completed in all patients with a median time of 12 months and 13 months in group 1 and 2, respectively. On radiographic evaluation radial inclination, radial height and volar tilt were not significantly different between group 1 and 2, respectively. There were no significant differences between two groups in regard to wrist rotational degrees measured in last follow-up visit. Sonoma Wrx Device is reliable and effective in terms of achieving satisfactory outcomes in treatment of distal radius fractures. It may be reasonable to use this device to prevent complications that are related to extensive soft tissue dissection.

Does a Volar Locking Plate Provide Equivalent Stability as a Dorsal Nonlocking Plate in a Dorsally Comminuted Distal Radius Fracture?

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). 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. 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. 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.

Biomechanical Evaluation of Volar Locking Plates for Distal Radius Fractures

Fixed-angle devices have been a major advancement in orthopedic fracture care and have become an attractive option for fixation of distal radius fractures. Several volar locking plates exist, but there is insufficient literature comparing the strengths of these plates. This study compares the biomechanical strength of two popular volar locking plate systems (Synthes LCP and Hand Innovations DVR-A) along with a nonlocking volar T-plate (Synthes). Twenty-three formalin-fixed cadaveric forearms were divided into three groups with similar ages and bone densities. An unstable extra-articular fracture was created using a standardized osteotomy. Each group was fixed with one of the three plates. Each specimen was loaded in axial compression for 2000 cycles at a force of 400 N. Each specimen that completed cyclic testing was loaded to failure. Stiffness, yield point, and ultimate strength were recorded for each construct. Each fixed-angle construct completed all 2000 cycles. The nonlocking plates failed at an average of 560 cycles. The mean stiffness of the DVR-A, LCP, and the volar T-plates were 277.00, 343.17, and 175.67 N/mm, respectively. There was a statistically significant difference between both fixed-angle plates and the nonlocking plate (p < 0.05). The difference between each fixed-angle construct did not reach significance. Yield point and ultimate strength could only be determined for the two fixed-angle devices. There was no statistically significant difference between the constructs for both yield point (DVR-A = 855.56 N, LCP = 894.15 N) and ultimate strength (DVR-A = 1,021.97 N, LCP = 1,114.87 N). Given our data, fixed-angle constructs withstand cyclical loading representing normal physiologic forces encountered during post-operative rehabilitation. There was no significant biomechanical difference between the two fixed-angle constructs. Our results support that volar fixed-angle locking plates are an effective treatment for unstable extra-articular distal radius fractures, allowing early postoperative rehabilitation to safely be initiated.

Volar Versus Dorsal Fixed-Angle Fixation of Dorsally Unstable Extra-Articular Distal Radius Fractures: A Biomechanic Study

To evaluate and compare the biomechanic rigidity and strength of 3 fixed-angle plates used to treat extra-articular distal radius fractures that are dorsally unstable. Volar fixed-angle plates were compared with a dorsal fixed-angle nail plate. Three plate constructs were tested: the dorsal nail plate (DNP), distal volar radius (DVR) plate, and locking compression plate (LCP) volar distal radius plate. With anatomic, third-generation, artificial composite radii, dorsally unstable extra-articular distal radius fracture models were made by cutting a wedge osteotomy with an 8-mm dorsal gap 1 cm from the articular surface. These models were then fixed with the 3 implants by the method recommended by the manufacturer. The proximal radii of each specimen were attached to the base of a materials testing machine with a probe centered at the radial side of the lunate fossa. The specimens were loaded at a constant rate to failure under axial compression. Load and displacement were plotted graphically, and the resulting rigidities and strengths of each plate were assessed statistically. The DVR group had significantly greater stiffness than the LCP group. The DVR group had significantly higher maximum loads than both the DNP and LCP groups. There were no significant differences in yield loads. Both the DNP and DVR groups had significantly less displacement at yield than the LCP group. These 3 groups had similar yield loads. However, the LCP was less stiff than the DVR and had more displacement at yield than both the DVR and DNP. The yield load of all 3 implants was much higher than previously described loads for active wrist and finger motion.

Treatment of Unstable Extra-Articular Distal Radius Fractures by Modified Intrafocal Kapandji Method

The authors prospectively assess the results of surgically treated, unstable extra-articular distal radius fractures from 29 patients with good bone quality. Mean age was 49 years, ranging from 22 to 69 years; the female gender was the most frequently affected (58.6% of the cases). Surgical fixation was indicated for fractures presenting an angulation above 20 degrees , marked dorsal comminution, and radius shortening in excess of 10 mm on initial x-rays (anteroposterior and lateral views). The Kapandji technique, with intrafocal, nonthreaded Kirschner wires, was employed. Clinical data assessed anatomic aspects according to Scheck, functional aspect after Gartland and Werley, strength by Scheck's methods, and esthetic by Frykman's criteria. Functional assessment, according to Gartland and Werley, revealed 72.1% of excellent and good results at 3 months; 89.7% at 6 months; and 96.6% at 12 months. Immediate postoperative reduction was not maintained at the final follow-up at 12 months; however, that loss was not severe, and the anatomic outcome was good and excellent in 96.6% of the cases. Six patients presented complications. Four patients presented reflex sympathetic dystrophy; 1 patient had a superficial Kirschner wire infection, and another patient had radial nerve superficial branch paresthesia. The employed technique showed to be effective in the treatment of unstable, extra-articular fractures of the distal radius. It is easy to learn and to perform. The device employed has a low cost and is widely available in operation rooms.

A Biomechanical Comparison of a Dorsal 3.5-mm T-Plate and a Volar Fixed-Angle Plate in a Model of Dorsally Unstable Distal Radius Fractures

To compare the biomechanical stability of internal fixation of extra-articular, dorsally unstable distal radius fractures fixed by 1 of 2 methods, either a standard dorsal nonlocked T-plate or a volar locked fixed-angle plate. Biomechanical cadaveric study. Biomechanical testing laboratory. In 6 matched pairs of fresh-frozen cadaveric specimens, a simulated unstable extra-articular distal radius fracture was created. The fractures were stabilized with either a dorsal 3.5-mm stainless steel T-plate or a titanium locked volar fixed-angle plate. Specimens were axially loaded at 5 points (centrally, volarly, dorsally, radially, and ulnarly) and then cyclically loaded for 5000 cycles with an 80 N central load. Postcyclical loading, specimens were once again axially loaded at the 5 points. Initial fixation stiffness and stiffness after midaxial cyclical loading was compared at the 5 points. With the volar locked fixed-angle plate, fixation was significantly stiffer than with the dorsal nonlocked T-plate for ulnar and volar loading in single-cycle testing. After cyclic loading, the locked volar fixed-angle plate maintained more of its initial stiffness than the dorsal nonlocked T-plate. The dorsal 3.5-mm stainless steel T-plate's stiffness when dorsally loaded significantly decreased after cyclical loading. The volar locked fixed-angle plate maintained a greater percentage of its initial stiffness after cyclic loading compared to the dorsal nonlocked plate. Also, the volar locked plate was stiffer than the dorsal nonlocked plate for all loading configurations tested except when subjected to a dorsally applied eccentric load.

Biomechanics in uniaxial compression of three distal radius volar plates

Purpose A new fixed-angle volar plate for a dorsally displaced distal radius fracture was designed with the aim of avoiding soft tissue problems due to dorsal plating. The purpose of this study was to compare the biomechanical properties of this new plate with 2 existing volar plates in a cadaver model. Methods Three different plates were applied on surgically simulated unstable extra-articular distal radius fractures in formalin-fixed cadaver radiuses. Group 1 (volarly placed AO titanium Distal Radius plates [Synthes Ltd, Paoli, PA]; n = 6), group 2 (volarly placed titanium Symmetry plates [DePuy ACE Co, El Segundo, CA]; n = 6), and group 3 (volarly placed newly designed titanium plates; n = 6) were tested to failure under axial compression with a materials testing machine. Specimens of all 3 groups had similar bone mineral density. Results Group 3 specimens had significantly greater elastic limit and ultimate strength than the other 2 groups. Specimens of group 3 had the greatest rigidity, although this was statistically insignificant compared with the other 2 groups. All plates (groups 1, 2, 3) failed in apex volar angulation. Conclusions The newly designed plate fixation system is the strongest of the systems tested and may offer adequate stability for the treatment of a distal radius fracture in which the dorsal and/or volar metaphyseal cortex is comminuted severely.

An analysis of bone stresses and fixation stability using a finite element model of simulated distal radius fractures

A 3-dimensional finite element model was used to study pin fixation in simulated unstable extra-articular distal radius fractures. Bone geometry and material properties were generated from computed tomography. The model was validated in cadaver testing. The model is robust and an accurate predictor of bone stresses and fracture stability under pure axial load. Three different pinning configurations and 3 different pin materials were evaluated. Crossed pinning provided greater fracture stability and a broader distribution of bone stresses than pinning through the radius styloid alone. Steel pins provided greater fracture stability; however, bioabsorbable pins produced lower stress concentration in the bone near the pins. A finite element model is useful in showing differences between various pin constructs in the treatment of distal radius fractures.

Supplemental pinning improves the stability of external fixation in distal radius fractures during simulated finger and forearm motion.

External fixation is commonly used in the treatment of distal radius fractures. In this in vitro study, we investigated changes in fracture stability when using supplemental radial styloid pinning in combination with external fixation. Eight previously frozen cadaveric upper extremities were mounted in a computer-controlled wrist-loading apparatus. This device was used to generate finger and forearm motions through loading relevant tendons. An unstable extra-articular distal radius fracture was simulated by removing a dorsal wedge from the distal radius metaphysis. An electromagnetic tracking system measured fragment motion following randomized application of a Hoffman external fixator, a Hoffman external fixator with 2 supplemental radial styloid pins, and a dorsal 3.5-mm AO plate. Regardless of the fixation technique used in this unstable fracture model, fragment motion occurred when postoperative finger and forearm motions were simulated. The addition of radial styloid pins to a construct stabilized by an external fixator significantly improved fragment stability, approaching that achieved with the dorsal AO plate.

Augmented external fixation of distal radius fractures: A biomechanical analysis

An in vitro model of an unstable extra-articular distal radius fracture was created in 8 fresh-frozen cadaveric specimens and stabilized with an external fixator. Rotation and translation kinematics of the distal radial fracture fragment were measured in relation to the proximal radius during physiologic loading, using infrared light-emitting diodes and a 3-dimensional motion-sensing device. The effect of supplemental single and combination Kirschner wire (K-wire) fixation on fracture fragment stability was assessed. Fixation of supplemental K-wires to the fixator frame via a custom-developed outrigger assembly was also analyzed. Significant reductions in sagittal plane (flexion/extension) rotation and neutral zone were recorded when the fracture fragment was stabilized with a single styloid or dorsal transfixion K-wire. Equivalent stability was afforded by attachment of a nontransfixion K-wire to the fixator frame via the outrigger assembly. The dorsal constructs compared favorably to the styloid constructs in reduction of the sagittal plane neutral zone and coronal (radioulnar) rotation. These data lend biomechanical support to the concept of augmentation of distal radius external fixation and provide a physiologic model to test fixation methods for other fracture patterns.