[The significance of displacement in dorsally angled distal radial fractures]. / Betydningen av feilstilling etter dorsalt vinklet distal radiusfraktur.

BACKGROUND: Distal radial fractures occur very frequently. Most are dorsally displaced (Colles' fracture). In contrast to previously, approximately a quarter of these patients now undergo surgery. This is more than the number that is reduced and immobilised in a plaster cast. Volar plate osteosynthesis is now the most common type of surgery. There is great uncertainty regarding indications for surgery. METHOD: The article is based on own research, a search in PubMed and a review of reference lists to identify articles that compare radiological and clinical outcomes after Colles' fractures. RESULTS: A number of national orthopaedic associations have reviewed the literature in an attempt to draw up guidelines for indications for performing surgery on distal radial fractures, without being able to arrive at definite recommendations based on randomised studies. Our review of the literature indicates a very uncertain correlation between radiological displacement and the final clinical outcome. This applies particularly to elderly patients (over 55-65), where by far the majority of the studies do not find any such correlation. Complications and reoperation are common among patients who have undergone volar plate surgery. INTERPRETATION: There is surprisingly little correlation between the radiological and clinical outcome after Colles' fractures. A practice where a large proportion of patients undergo surgery is probably not justified. Elderly patients will very seldom benefit from surgery in the longer term.

A comparative study of Colles' fractures in patients between fifty and seventy years of age: percutaneous K-wiring versus volar locking plating.

PURPOSE: This retrospective study was to compare the clinical outcomes of volar locking plating (VLP) and percutaneous Kirschner wiring (PKW) for the management of displaced Colles type distal radius fractures in patients between 50 and 70 years old. METHODS: There were 31 elderly patients with displaced Colles' fractures treated by VLP. We compared them to 31 match-paired patients treated by PKW. The patients were matched according to age (within five years) and sex. All patients were followed up retrospectively for at least 12 months. The functional outcomes and radiological results were compared between the two groups. RESULTS: All fractures healed within three months. There were two complications (6.5%) in the PKW group and one complication (3.2%) in the VLP group. At final follow-up, wrist flexion, extension, and ulnar deviation were significantly better in the VLP group compared with the PKW group (all p values<0.05). According to modified Green and O'Brien criteria, the VLP group showed a trend towards increased rate of satisfactory outcome compared with the PKW group (p = 0.09). CONCLUSION: For the treatment of displaced Colles' fractures in patients between 50 and 70 years old, both groups had high union rate and low complication rate. However, better functional results can be expected in association with open reduction and volar locking plating.

Percutaneous K-wire fixation versus palmar plating with locking screws for Colles' fractures.

Different methods exist to treat distal radius fractures. A prospective randomized study was conducted to establish whether palmar plate fixation with locking screws gave better results than percutaneous K-wire fixation in patients over 50 years of age. Only fractures with dorsal displacement after a simple fall were included in the study. Twenty wrists were treated with K-wires and 20 with a plate. Radiological parameters were measured on preoperative radiographs and at five weeks postoperatively. Clinical results and DASH scores were determined at three months postoperatively and at more than one year. No significant difference in radial inclination, palmar tilt, clinical outcome and DASH score was found between plating and K-wires, but the mean difference in ulnar variance between pre- and postoperative radiographs was significantly better with plates. It can be concluded that plates were superior to K-wires in restoring ulnar variance, but functional outcome was similar with both techniques.

The Influence of Ibuprofen on the Healing of Nonsurgically Treated Colles' Fractures.

Nonsteroidal anti-inflammatory drugs can delay bone healing. This knowledge is mainly derived from retrospective and animal studies. The authors therefore conducted a human study to investigate whether ibuprofen affects radiological, functional, densitometrical, and biochemical outcomes following a Colles' fracture, as well as the analgesic effect of ibuprofen. This was a single-center, triple-blinded, randomized, placebo-controlled clinical trial with a total of 96 patients. All of the patients received basic treatment with 1000 mg of acetaminophen 4 times daily. The placebo group received a placebo for 7 days. The 3-day ibuprofen group received 600 mg of ibuprofen 3 times daily for the first 3 days and a placebo for the following 4 days. The 7-day ibuprofen group received ibuprofen 3 times daily for 7 days. The primary outcome was the fragment migration for a period of 5 weeks. The secondary outcomes were changes in the wrist's range of motion; Disabilities of the Arm, Shoulder and Hand score; bone mineral density of the injured wrist; changes in serum CrossLaps (Roche Diagnostics) and osteocalcin; and analgesic effects. Analyses were performed according to an intention-to-treat approach. No significant differences in radiological migration or functional, densitometrical, and biochemical effects were established among the treatment groups (.06≤P≤.9). During the first 3 days, the pain score was lower (P=.02) in the ibuprofen groups than in the placebo group. The findings of this study offer an indication for ibuprofen as a bone-safe analgesic treatment after Colles' fracture and may be translated into other fields of cancellous bone fracture treatment. [Orthopedics. 2021;44(2):105-110.].

Global and Spatial Compartmental Interrelationships of Bone Density, Microstructure, Geometry and Biomechanics in the Distal Radius in a Colles' Fracture Study Using HR-pQCT.

Background: Bone parameters derived from HR-pQCT have been investigated on a parameter-by-parameter basis for different clinical conditions. However, little is known regarding the interrelationships of bone parameters and the spatial distribution of these interrelationships. In this work: 1) we investigate compartmental interrelationships of bone parameters; 2) assess the spatial distribution of interrelationships of bone parameters; and 3) compare interrelationships of bone parameters between postmenopausal women with and without a recent Colles' fracture. Methods: Images from the unaffected radius in fracture cases (n=84), and from the non-dominant radius of controls (n=98) were obtained using HR-pQCT. Trabecular voxel-based maps of local bone volume fraction (L.Tb.BV/TV), homogenized volumetric bone mineral density (H.Tb.BMD), homogenized µFEA-derived strain energy density (H.Tb.SED), and homogenized inter-trabecular distances (H.Tb.1/N) were generated; as well as surface-based maps of apparent cortical bone thickness (Surf.app.Ct.Th), porosity-weighted cortical bone thickness (Surf.Ct.SIT), mean cortical BMD (Surf.Ct.BMD), and mean cortical SED (Surf.Ct.SED). Anatomical correspondences across the parametric maps in the study were established via spatial normalization to a common template. Mean values of the parametric maps before spatial normalization were used to assess compartmental Spearman's rank partial correlations of bone parameters (e.g., between H.Tb.BMD and L.Tb.BV/TV or between Surf.Ct.BMD and Surf.app.Ct.Th). Spearman's rank partial correlations were also assessed for each voxel and vertex of the spatially normalized parametric maps, thus generating maps of Spearman's rank partial correlation coefficients. Correlations were performed independently within each group, and compared between groups using the Fisher's Z transformation. Results: All within-group global trabecular and cortical Spearman's rank partial correlations were significant; and the correlations of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, Surf.Ct.BMD-Surf.Ct.SED and Surf.Ct.SIT-Surf.Ct.SED were significantly different between controls and fracture cases. The spatial analyses revealed significant heterogeneous voxel- and surface-based correlation coefficient maps across the distal radius for both groups; and the correlation maps of H.Tb.BMD-L.Tb.BV/TV, H.Tb.BMD-H.Tb.1/N, L.Tb.BV/TV-H.Tb.1/N, H.Tb.1/N-H.Tb.SED and Surf.app.Ct.Th - Surf.Ct.SIT yielded small clusters of significant correlation differences between groups. Discussion: The heterogeneous spatial distribution of interrelationships of bone parameters assessing density, microstructure, geometry and biomechanics, along with their global and local differences between controls and fracture cases, may help us further understand different bone mechanisms of bone fracture.

Assessing forearm fracture risk in postmenopausal women.

UNLABELLED: A diverse array of bone density, structure, and strength parameters were significantly associated with distal forearm fractures in postmenopausal women, but most of them were also correlated with femoral neck areal bone mineral density (aBMD), which provides an adequate measure of bone fragility at the wrist for routine clinical purposes. INTRODUCTION: This study seeks to test the clinical utility of approaches for assessing forearm fracture risk. METHODS: Among 100 postmenopausal women with a distal forearm fracture (cases) and 105 with no osteoporotic fracture (controls), we measured aBMD and assessed radius volumetric bone mineral density, geometry, and microstructure; ultradistal radius failure load was evaluated in microfinite element (microFE) models. RESULTS: Fracture cases had inferior bone density, geometry, microstructure, and strength. The most significant determinant of fracture in five categories were bone density (femoral neck aBMD; odds ratio (OR) per standard deviation (SD), 2.0; 95% confidence interval (CI), 1.4-2.8), geometry (cortical thickness; OR, 1.5; 95% CI, 1.1-2.1), microstructure (structure model index (SMI); OR, 0.5; 95% CI, 0.4-0.7), and strength (microFE failure load; OR, 1.8; 95% CI, 1.3-2.5); the factor-of-risk (applied load in a forward fall / microFE failure load) was 15% worse in cases (OR, 1.9; 95% CI, 1.4-2.6). Areas under receiver operating characteristic curves (AUC) ranged from 0.62 to 0.68. The predictors of forearm fracture risk that entered a multivariable model were femoral neck aBMD and SMI (combined AUC, 0.71). CONCLUSIONS: Detailed bone structure and strength measurements provide insight into forearm fracture pathogenesis, but femoral neck aBMD performs adequately for routine clinical risk assessment.

Finite element modeling of the influence of hand position and bone properties on the Colles' fracture load during a fall.

Distal forearm fracture is one of the most frequently observed osteoporotic fractures, which may occur as a result of low energy falls such as falls from a standing height and may be linked to the osteoporotic nature of the bone, especially in the elderly. In order to prevent the occurrence of radius fractures and their adverse outcomes, understanding the effect of both extrinsic and intrinsic contributors to fracture risk is essential. In this study, a nonlinear fracture mechanics-based finite element model is applied to human radius to assess the influence of extrinsic factors (load orientation and load distribution between scaphoid and lunate) and intrinsic bone properties (age-related changes in fracture properties and bone geometry) on the Colles' fracture load. Seven three-dimensional finite element models of radius were created, and the fracture loads were determined by using cohesive finite element modeling, which explicitly represented the crack and the fracture process zone behavior. The simulation results showed that the load direction with respect to the longitudinal and dorsal axes of the radius influenced the fracture load. The fracture load increased with larger angles between the resultant load and the dorsal axis, and with smaller angles between the resultant load and longitudinal axis. The fracture load also varied as a function of the load ratio between the lunate and scaphoid, however, not as drastically as with the load orientation. The fracture load decreased as the load ratio (lunate/scaphoid) increased. Multiple regression analysis showed that the bone geometry and the load orientation are the most important variables that contribute to the prediction of the fracture load. The findings in this study establish a robust computational fracture risk assessment method that combines the effects of intrinsic properties of bone with extrinsic factors associated with a fall, and may be elemental in the identification of high fracture risk individuals as well as in the development of fracture prevention methods including protective falling techniques. The additional information that this study brings to fracture identification and prevention highlights the promise of fracture mechanics-based finite element modeling in fracture risk assessment.

Prediction of Colles' fracture load in human radius using cohesive finite element modeling.

Osteoporotic and age-related fractures are a significant public health problem. One of the most common osteoporotic fracture sites in the aging population is distal radius. There is evidence in the literature that distal radius fractures (Colles' fracture) are an indicative of increased risk of future spine and hip fractures. In this study, a nonlinear fracture mechanics-based finite element method is applied to human radius to assess its fracture load as a function of cortical bone geometry and material properties. Seven three-dimensional finite element models of radius were created and the fracture loads were determined by using cohesive finite element modeling which explicitly represents the crack and the fracture process zone behavior. The fracture loads found in the simulations (731-6793 N) were in the range of experimental values reported in the literature. The fracture loads predicted by the simulations decreased by 4-5% per decade based only on material level changes and by 6-20% per decade when geometrical changes were also included. Cortical polar moment of inertia at 15% distal radius showed the highest correlation to fracture load (r(2)=0.97). These findings demonstrate the strength of fracture mechanics-based finite element modeling and show that combining geometrical and material properties provides a better assessment of fracture risk in human radius.

Comparison of external fixation, locking and non-locking palmar plating for unstable distal radius fractures in the elderly.

This study compares the effectiveness of locking and non-locking palmar plating and external fixation for unstable distal radius fractures in the elderly. In a retrospective match-paired study, 45 patients aged 50 to 70 years who underwent surgery for C1/C2 distal radius fractures were evaluated. The surgical procedures were external fixation or plating with locking or non-locking palmar plates. Radiological and functional outcomes were assessed. Outcomes according to Gartland and Werley, Martini and the Disability of the Arm, Shoulder and Hand (DASH) questionnaire were compared. The locking palmar plate fixation method demonstrated significantly better radiological and functional results in comparison to external fixation and the non-locking palmar plating methods. The subjective assessment of plate fixation proved to be better than that of external fixation. Complications and reoperations were fewer for both plate fixation groups. Our data indicates that most displaced intra-articular distal radius fractures can be treated successfully with the locking palmar plate.

Association of bone mineral density with deformity of the distal radius in low-energy Colles' fractures in Japanese women above 50 years of age.

PURPOSE: To investigate whether the degree of radiographically observed pretreatment radius deformity of low-energy Colles' type distal radius fractures resulting from falls is associated with the degree of bone fragility as measured by bone mineral density (BMD) of the lumbar spine in Japanese women above 50 years of age. METHODS: The study subjects were 125 consecutive Japanese women older than 50 years of age with Colles' type (AO type A and C) dorsally angulated distal radius fractures caused by falls. Fractures due to high-energy injuries such as traffic accidents were excluded. Radius deformity was assessed on anteroposterior and lateral radiographs by measuring ulnar variance, radial inclination, and dorsal angulation at initial examination before manual repositioning of the bone. Bone mineral density of the lumbar spine was also measured by dual energy x-ray absorptiometry at the follow-up visit. RESULTS: There were significant differences in the respective values of ulnar variance, radial inclination, and dorsal angulation between patients with BMD values < 70% of the mean value of young adults and those with BMD values > or = 70%. Radius deformity was significantly greater for all parameters in the former group relative to the latter. The respective values of increased ulnar variance, decreased radial inclination, and increased dorsal angulation significantly correlated with lower BMD. Stepwise regression analysis of data of all subjects identified that ulnar variance was significantly associated with dorsal angulation, BMD, and radial inclination. The addition of body height, body weight, body mass index, and urinary type I collagen cross-linked N-telopeptides (bone resorption marker) to the regression analysis of data of a subset of patients confirmed that ulnar variance was significantly associated with BMD and radial inclination. CONCLUSIONS: There is a significant association between BMD of the lumbar spine and radiographic radius deformity seen in low-energy Colles' type distal radius fractures resulting from falls in Japanese women above 50 years of age. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic I.

Fast estimation of Colles' fracture load of the distal section of the radius by homogenized finite element analysis based on HR-pQCT.

Fractures of the distal section of the radius (Colles' fractures) occur earlier in life than other osteoporotic fractures. Therefore, they can be interpreted as a warning signal for later, more deleterious fractures of vertebral bodies or the femoral neck. In the past decade, the advent of HR-pQCT allowed a detailed architectural analysis of the distal radius and an automated but time-consuming estimation of its strength with linear micro-finite element (µFE) analysis. Recently, a second generation of HR-pQCT scanner (XtremeCT II, SCANCO Medical, Switzerland) with a resolution beyond 61 µm became available for even more refined biomechanical investigations in vivo. This raises the question how biomechanical outcome variables compare between the original (LR) and the new (HR) scanner resolution. Accordingly, the aim of this work was to validate experimentally a patient-specific homogenized finite element (hFE) analysis of the distal section of the human radius for the fast prediction of Colles' fracture load based on the last generation HR-pQCT. Fourteen pairs of fresh frozen forearms (mean age = 77.5±9) were scanned intact using the high (61 µm) and the low (82 µm) resolution protocols that correspond to the new and original HR-pQCT systems. From each forearm, the 20mm most distal section of the radius were dissected out, scanned with µCT at 16.4 µm and tested experimentally under compression up to failure for assessment of stiffness and ultimate load. Linear and nonlinear hFE models together with linear micro finite element (µFE) models were then generated based on the µCT and HR-pQCT reconstructions to predict the aforementioned mechanical properties of 24 sections. Precision errors of the short term reproducibility of the FE analyses were measured based on the repeated scans of 12 sections. The calculated failure loads correlated strongly with those measured in the experiments: accounting for donor as a random factor, the nonlinear hFE provided a marginal coefficient of determination (Rm2) of 0.957 for the high resolution (HR) and 0.948 for the low resolution (LR) protocols, the linear hFE with Rm2 of 0.957 for the HR and 0.947 for the LR protocols. Linear µFE predictions of the ultimate load were similar with an Rm2 of 0.950 for the HR and 0.954 for the LR protocols, respectively. Nonlinear hFE strength computation led to precision errors of 2.2 and 2.3% which were higher than the ones calculated based on the linear hFE (1.6 and 1.9%) and linear µFE (1.2 and 1.6%) for the HR and LR protocols respectively. Computation of the fracture load with nonlinear hFE demanded in average 6h of CPU time which was 3 times faster than with linear µFE, while computation with linear hFE took only a few minutes. This study delivers an extensive experimental and numerical validation for the application of an accurate and fast hFE diagnostic tool to help in identifying individuals who may be at risk of an osteoporotic wrist fracture and to follow up pharmacological and other treatments in such patients.

Re-engineering Colles: form, function and fragility fractures.

Of the twenty nine anatomy professors in the Royal College of Surgeons in Ireland, primus inter pares is Abraham Colles. In his 1811 book A Treatise on Surgical Anatomy he revolutionised the subject by teaching it topographically, seeking "to describe the relative position of the parts and to point out the subservience of anatomical knowledge to surgical practice". Today we have extended this to 'clinical practice' and, in the Anatomy Room, students are guided through each region by clinically trained staff, from surface anatomy via three-dimensional dissection to radiological images. This is augmented by online histology and radiology courses and DVDs in which dissection footage, edited by a content analysis engine, is used to preview and review practical classes. In the same book, Colles also wrote that 'the fixed and immutable laws of mathematics are little applicable to the science of medicine'. Computer-aided learning argues against this. So does research which links fatigue microdamage to bone remodelling and the development of algorithms to predict, and thus prevent, osteoporotic fractures. Mechanical principles are being used to develop scaffolds for tissue engineering and to optimise the mechanical environment of seeded mesenchymal stem cells. While Colles' teaching approach holds true, in biomechanics, tissue engineering and computing, mathematical laws are now being successfully applied to medical science.

Sagittal wrist motion of carpal bones following intraarticular fractures of the distal radius.

Forty patients (mean age, 37 years) with intraarticular C2 and C3 Colles fractures were treated by open reduction, internal fixation and bone grafting. At a mean follow-up of 8 years radiocarpal and midcarpal motion was evaluated, the depth of the articular surface of the distal radius in the sagittal plane was measured and the presence of arthritis was noted. The fractures healed with a mean palmar tilt of 6 degrees , a mean ulnar tilt of 18 degrees and ulna variance within 1 mm of the contralateral side. The depth of the articular surface of the distal radius was 1.3 mm greater than the uninvolved side. Measurement of carpal bone angles relative to the radius in maximum flexion and extension revealed lunate extension of 23 degrees , lunate flexion of 15 degrees , capitate extension of 62 degrees , capitate flexion of 40 degrees . There was a significant correlation between articular surface depth and radiocarpal motion.

Forearm fracture.

Bone mineral density of the distal forearm decreases with age in women, and this results in an increased risk of forearm fractures. Men have no increase in risk of forearm fractures with age because they have a higher peak bone mass at this site and less of a decrease in bone mineral density with ageing. Bone loss from the forearm slows in women after the age of 65 years in women and this may account for the plateau in forearm fracture rate after this age. Women with forearm fractures have twice the expected risk of vertebral and hip fractures. Forearm fractures before the age of 60 years are associated with an increase in the risk of vertebral fractures. Forearm fractures after the age of 70 years are associated with an increased risk of hip fractures. Thus, women presenting with forearm fractures are a good target population for the prevention of osteoporosis.

Carboxylation of osteocalcin in post-menopausal osteoporotic women following vitamin K and D supplementation.

The effect of vitamin supplements on bone metabolism indices in patients with osteoporosis has received scant attention in the literature. Over a 2-week period, vitamin supplements of K and K+D were given to 20 post-menopausal osteoporotic women with previous Colles fractures. Osteoporosis was confirmed by bone mass measurements that demonstrated that broadband ultrasound attenuation (os calcis) was almost as discriminatory as dual energy X-ray absorptiometry (spine and hip) in Colles fracture patients compared with matched controls. Vitamin K corrected the carboxylation defect in osteocalcin and while less marked 4 weeks later, the improvement was still detectable. The result after K+D was similar. The level of carboxylation became the same as in premenopausal women. Total osteocalcin level (bound) osteocalcin. While there was vitamin K correctable undercarboxylation of osteocalcin, simultaneously there was no evidence of undercarboxylation of prothrombin.

Update on the use of distal radial bone density measurements in prediction of hip and Colles' fracture risk.

A controversy has developed around the question as to whether bone density values from the distal radius can be used to accurately predict risk of future fractures. To address this question, two separate studies were undertaken: (a) Bone density was measured in 460 healthy ambulatory women living in retirement centers in the state of North Carolina; 83% of these women were followed for up to 60 months for occurrence of minimal trauma hip and wrist fractures. Thirty-one minimal trauma fractures were reported in our study population, representing 8% of those followed. The fracture incidence density rate showed a close inverse relationship with incremental changes in bone density at the distal site. Twenty-eight of the 31 fractures were reported in women with bone density values below the 325-mg/cm2 "at risk" value. (b) Bone density values of the distal radius and the lumbar spine from 360 women (aged 18-85 years) from the Chapel Hill area were used to analyze the error in predicting individual spinal density from the distal radial density. Although the overall correlation was high (r = 0.67) and the confidence intervals were narrow, the prediction intervals were quite wide. Thus, prediction of an individual value of spine density from the distal radius density would result in a value with a range too wide to be clinically useful. We conclude that single-photon absorptiometry appears to be a useful tool for screening normal populations of asymptomatic women for prediction of hip or Colles' fracture risk even though it has limited usefulness in prediction of spinal fracture risk or individual values for spinal density.

Closed reduction of colles fractures: comparison of manual manipulation and finger-trap traction: a prospective, randomized study.

BACKGROUND: An optimal outcome of closed treatment of a Colles fracture may depend on accurate reduction and adequate immobilization. It has been suggested that the use of finger-trap traction results in a better reduction and a lower rate of redisplacement than manual manipulation does, but to our knowledge these concepts have never been evaluated scientifically. We compared these two methods in a prospective, randomized controlled trial. METHODS: Two hundred and twenty-three patients with 225 displaced Colles-type fractures were randomized to treatment with closed reduction with either finger-trap traction (112 patients) or manual manipulation (111 patients). The fractures were assessed radiographically by measurement of the radial angle, dorsal tilt, and radial shortening before reduction, immediately after reduction, and at one and five weeks after reduction. RESULTS: The groups were comparable with regard to age, sex, side of injury, fracture grade, and amount of displacement at presentation. No significant differences were found between the alignment of the fractures in the two treatment groups at any time. With dorsal tilt of <10 degrees and radial shortening of <5 mm considered acceptable, the two techniques both produced an 87% rate of satisfactory reductions. However, the percentages of fractures in an acceptable alignment were only 57% and 50% at one week after finger-trap traction and manual manipulation, respectively, and only 27% and 32% at five weeks. The failure rates did not differ significantly between the two groups. CONCLUSIONS: The two methods of fracture reduction did not differ with regard to the eventual position of the fracture or the rate of failure. Although closed reduction was successful for the majority of fractures, most redisplaced substantially during the period of cast immobilization.

Biomechanical evaluation of fixation of intra-articular fractures of the distal part of the radius in cadavera: Kirschner wires compared with calcium-phosphate bone cement.

BACKGROUND: The purpose of this study was to compare the biomechanical efficacy of an injectable calcium-phosphate bone cement (Skeletal Repair System [SRS]) with that of Kirschner wires for the fixation of intraarticular fractures of the distal part of the radius. METHODS: Colles fractures (AO pattern, C2.1) were produced in ten pairs of fresh-frozen human cadaveric radii. One radius from each pair was randomly chosen for stabilization with SRS bone cement. These ten radii were treated with open incision, impaction of loose cancellous bone with use of a Freer elevator, and placement of the SRS bone cement by injection. In the ten control specimens, the fracture was stabilized with use of two horizontal and two oblique Kirschner wires. The specimens were cyclically loaded to a peak load of 200 newtons for 2000 cycles to evaluate the amount of settling, or radial shortening, under conditions simulating postoperative loading with the limb in a cast. Each specimen then was loaded to failure to determine its ultimate strength. RESULTS: The amount of radial shortening was highly variable among the specimens, but it was consistently higher in the Kirschner-wire constructs than in the bone fixed with SRS bone cement within each pair of radii. The range of shortening for all twenty specimens was 0.18 to 4.51 millimeters. The average amount of shortening in the SRS constructs was 50 percent of that in the Kirschner-wire constructs (0.51+/-0.34 compared with 1.01+/-1.23 millimeters; p = 0.015). With the numbers available, no significant difference in ultimate strength was detected between the two fixation groups. CONCLUSIONS: This study showed that fixation of an intra-articular fracture of the distal part of a cadaveric radius with biocompatible calcium-phosphate bone cement produced results that were biomechanically comparable with those produced by fixation with Kirschner wires. However, the constructs that were fixed with calcium-phosphate bone cement demonstrated less shortening under simulated cyclic load-bearing.