Analysis of fracture healing process by HR-pQCT in patients with distal radius fracture.

INTRODUCTION: High-resolution peripheral quantitative computed tomography (HR-pQCT) has enabled us to observe the changes in bone microarchitecture over time in vivo. In this study, the process of fracture healing was analyzed using HR-pQCT in patients with distal radius fracture who underwent osteosynthesis. MATERIALS AND METHODS: A total of 10 fracture sites identified from four patients with a distal radius fracture who underwent internal fixation with a volar locking plate (mean age 68.8 years, all women) were investigated. HR-pQCT was performed within a week (baseline) 4, 12, and 24 weeks after fracture. Rectangular region of interest (ROI) was established in the fracture site, inner callus, and external callus area, and the changes in bone mineral density (BMD) in each region were analyzed. RESULTS: From baseline to 24 weeks post-fracture, the BMD changed from 105.5 (95% CI 98.6-113) to 428.0 (331-554) mgHA/ccm at the fracture site, from 111.0 (104-119) to 375.3 (290-486) mgHA/ccm at the inner callus area, and from 98.5 (91.6-106) to 171.6 (132-222) mgHA/ccm at the external callus area. The BMD increased at the fracture site and inner callus area, but increased only slightly at the external callus area. At 24 weeks post-fracture, the BMD at the fracture site and inner callus area was significantly higher than the external callus area. CONCLUSION: In the healing process of postoperative distal radius fractures, increased BMD at the inner surface of the fracture site was confirmed in all fractures. Bone formation on the endosteal side may be a necessary condition for bone union of distal radius fractures.

Nanoscale perfluorocarbon expediates bone fracture healing through selectively activating osteoblastic differentiation and functions.

BACKGROUND AND RATIONALE: Fracture incidence increases with ageing and other contingencies. However, the strategy of accelerating fracture repair in clinical therapeutics remain a huge challenge due to its complexity and a long-lasting period. The emergence of nano-based drug delivery systems provides a highly efficient, targeted and controllable drug release at the diseased site. Thus far, fairly limited studies have been carried out using nanomedicines for the bone repair applications. Perfluorocarbon (PFC), FDA-approved clinical drug, is received increasing attention in nanomedicine due to its favorable chemical and biologic inertness, great biocompatibility, high oxygen affinity and serum-resistant capability. In the premise, the purpose of the current study is to prepare nano-sized PFC materials and to evaluate their advisable effects on promoting bone fracture repair. RESULTS: Our data unveiled that nano-PFC significantly enhanced the fracture repair in the rabbit model with radial fractures, as evidenced by increased soft callus formation, collagen synthesis and accumulation of beneficial cytokines (e.g., vascular endothelial growth factor (VEGF), matrix metalloprotein 9 (MMP-9) and osteocalcin). Mechanistic studies unraveled that nano-PFC functioned to target osteoblasts by stimulating their differentiation and activities in bone formation, leading to accelerated bone remodeling in the fractured zones. Otherwise, osteoclasts were not affected upon nano-PFC treatment, ruling out the potential target of nano-PFC on osteoclasts and their progenitors. CONCLUSIONS: These results suggest that nano-PFC provides a potential perspective for selectively targeting osteoblast cell and facilitating callus generation. This study opens up a new avenue for nano-PFC as a promising agent in therapeutics to shorten healing time in treating bone fracture.

Evaluation of Hip Geometry Parameters in Patients With a Distal Radius Fracture.

BACKGROUND: Patients with a distal radius fracture (DRF) have an increased risk of subsequent fractures including hip fractures. The purpose of this study was to evaluate whether women with a DRF have certain hip geometry parameters known to indicate susceptibility to hip fractures. METHODS: We compared bone mineral density (BMD) and hip geometry parameters (hip axis length, neck shaft angle, mean cortical thickness, femur neck width, cross-sectional area [CSA], cross-sectional moment of inertia, section modulus, and buckling ratio) in 181 women with a DRF (DRF group) and 362 propensity score-matched women without a fracture (control group). We evaluated the associations between DRF and hip geometry parameters using logistic regression analysis. RESULTS: The DRF group had lower hip BMD; lower cortical thickness, CSA, and section modulus; and higher buckling ratio than the control group (all p < 0.05). The occurrence of a DRF was significantly associated with decreases in neck shaft angle (odds ratio [OR], 1.047; 95% confidence interval [CI], 1.008-1.088) and CSA (OR, 3.114; 95% CI, 1.820-5.326) after adjusting for age, BMI, and total hip BMD. CONCLUSIONS: In this study, women with a DRF were more likely than women without a DRF to have hip geometry parameters known to indicate susceptibility to hip fractures. Our results suggest that not only low hip BMD but also a decreased CSA could account for the increased risk of subsequent hip fracture in patients with a DRF.

Do 3-D Printed Handheld Models Improve Surgeon Reliability for Recognition of Intraarticular Distal Radius Fracture Characteristics?

BACKGROUND: For fracture care, radiographs and two-dimensional (2-D) and three-dimensional (3-D) CT are primarily used for preoperative planning and postoperative evaluation. Intraarticular distal radius fractures are technically challenging to treat, and meticulous preoperative planning is paramount to improve the patient's outcome. Three-dimensionally printed handheld models might improve the surgeon's interpretation of specific fracture characteristics and patterns preoperatively and could therefore be clinically valuable; however, the additional value of 3-D printed handheld models for fractures of the distal radius, a high-volume and commonly complex fracture due to its intraarticular configuration, has yet to be determined. QUESTIONS/PURPOSES: (1) Does the reliability of assessing specific fracture characteristics that guide surgical decision-making for distal radius fractures improve with 3-D printed handheld models? (2) Does surgeon agreement on the overall fracture classification improve with 3-D printed handheld models? (3) Does the surgeon's confidence improve when assessing the overall fracture configuration with an additional 3-D model? METHODS: We consecutively included 20 intraarticular distal radius fractures treated at a Level 1 trauma center between May 2018 and November 2018. Ten surgeons evaluated the presence or absence of specific fracture characteristics (volar rim fracture, die punch, volar lunate facet, dorsal comminution, step-off > 2 mm, and gap > 2 mm), fracture classification according to the AO/Orthopaedic Trauma Association (OTA) classification scheme, and their confidence in assessing the overall fracture according to the classification scheme, rated on a scale from 0 to 10 (0 = not at all confident to 10 = very confident). Of 10 participants regularly treating distal radius fractures, seven were orthopaedic trauma surgeons and three upper limb surgeons with experience levels ranging from 1 to 25 years after completion of residency training. Fractures were assessed twice, with 1 month between each assessment. Initially, fractures were assessed using radiographs and 2-D and 3-D CT images (conventional assessment); the second time, the evaluation was based on radiographs and 2-D and 3-D CT images with an additional 3-D handheld model (3-D printed handheld model assessment). On both occasions, fracture characteristics were evaluated upon a surgeon's own interpretation, without specific instruction before assessment. We provided a sheet demonstrating the AO/OTA classification scheme before evaluation on each session. Multi-rater Fleiss's kappa was used to determine intersurgeon reliability for assessing fracture characteristics and classification. Confidence regarding assessment of the overall fracture classification was assessed using a paired t-test. RESULTS: We found that 3-D printed models of intraarticular distal radius fractures led to no change in kappa values for the reliability of all characteristics: volar rim (conventional kappa 0.19 [95% CI 0.06 to 0.32], kappa for 3-D handheld model 0.23 [95% CI 0.11 to 0.36], difference of kappas 0.04 [95% CI -0.14 to 0.22]; p = 0.66), die punch (conventional kappa 0.38 [95% CI 0.15 to 0.61], kappa for 3-D handheld model 0.50 [95% CI 0.23 to 0.78], difference of kappas 0.12 [95% CI -0.23 to 0.47]; p = 0.52), volar lunate facet (conventional kappa 0.31 [95% CI 0.14 to 0.49], kappa for 3-D handheld model 0.48 [95% CI 0.23 to 0.72], difference of kappas 0.17 [95% CI -0.12 to 0.46]; p = 0.26), dorsal comminution (conventional kappa 0.36 [95% CI 0.13 to 0.58], kappa for 3-D handheld model 0.31 [95% CI 0.11 to 0.51], difference of kappas -0.05 [95% CI -0.34 to 0.24]; p = 0.74), step-off > 2 mm (conventional kappa 0.55 [95% CI 0.29 to 0.82], kappa for 3-D handheld model 0.58 [95% CI 0.31 to 0.85], difference of kappas 0.03 [95% CI -0.34 to 0.40]; p = 0.87), gap > 2 mm (conventional kappa 0.59 [95% CI 0.39 to 0.79], kappa for 3-D handheld model 0.69 [95% CI 0.50 to 0.89], difference of kappas 0.10 [95% CI -0.17 to 0.37]; p = 0.48). Although there appeared to be categorical improvement in kappa values for some fracture characteristics, overlapping CIs indicated no change. Fracture classification did not improve (conventional diagnostics: kappa 0.27 [95% CI 0.14 to 0.39], conventional diagnostics with an additional 3-D handheld model: kappa 0.25 [95% CI 0.15 to 0.35], difference of kappas: -0.02 [95% CI -0.18 to 0.14]; p = 0.81). There was no improvement in self-assessed confidence in terms of assessment of overall fracture configuration when a 3-D model was added to the evaluation process (conventional diagnostics 7.8 [SD 0.79 {95% CI 7.2 to 8.3}], 3-D handheld model 8.5 [SD 0.71 {95% CI 8.0 to 9.0}], difference of score: 0.7 [95% CI -1.69 to 0.16], p = 0.09). CONCLUSIONS: Intersurgeon reliability for evaluating the characteristics of and classifying intraarticular distal radius fractures did not improve with an additional 3-D model. Further studies should evaluate the added value of 3-D printed handheld models for teaching surgical residents and medical trainees to define the future role of 3-D printing in caring for fractures of the distal radius. LEVEL OF EVIDENCE: Level II, diagnostic study.

Obese Children Have Different Forearm Fracture Characteristics Compared With Normal-weight Children.

BACKGROUND: Current estimates suggest that one third of children and adolescents are overweight and 1 in 5 are obese. Obese children are at increased risk of sustaining more complex fractures, failing nonoperative treatment, and experiencing more complications during treatment. The purpose of this study was to compare forearm fracture characteristics, treatment, and complications in grouped overweight and obese [OW+OB; body mass index-for-age percentile (BMI%) ≥85] pediatric patients compared with normal-weight (NW; BMI%≤84) patients. METHODS: This was a retrospective comparative study of patients aged 2 to 17 years old who presented with a forearm fracture resulting from low-energy trauma between January 2010 and September 2017. Patients with incomplete height and weight data; an underlying condition that predisposes to fractures or altered fracture healing; and torus, greenstick, pathologic, and high-energy fractures were excluded. Demographics, fracture characteristics, treatment, and complications were recorded. Descriptive and inferential analyses were conducted. RESULTS: A total of 565 patients (403 NW, 162 OW+OB) met the inclusion criteria. NW children sustained open fractures nearly twice as frequently as the OW+OB children but this was not statistically significant (9.7% vs. 4.9%; P=0.065). Subanalysis showed that NW children were 4.1 times more likely to sustain an open fracture compared with obese (BMI%≥95) children (9.7% vs. 2.4%; P=0.029). A significant relationship was found between BMI% and location of the fracture, the bones involved, and fracture type. The OW+OB children sustained more distal forearm fractures than midshaft and proximal forearm fractures. Isolated radial shaft fractures were more common in the OW+OB group, whereas isolated ulnar shaft fractures were more common in the NW group. There was no difference in associated neurovascular injury, initial nonoperative versus operative management, failure of nonoperative treatment, and treatment complications. CONCLUSIONS: OW+OB children have different forearm fracture characteristics compared with their NW peers. The thick soft tissue envelope in obese children may be protective against an open forearm fracture. In contrast to previous studies, obesity was not associated with failure of nonoperative treatment or a higher rate of complications. LEVEL OF EVIDENCE: Level III-prognostic.

Altered gene and protein expressions of vitamin D receptor in skeletal muscle in sarcopenic patients who sustained distal radius fractures.

Despite the presence of vitamin D receptor (VDR) in skeletal muscle cells, the relationship between VDR expressions and muscle mass or function has not been well studied. The purpose of this study was to compare VDR gene and protein expression in the forearm muscle between sarcopenic and non-sarcopenic individuals who have sustained distal radius fractures. Twenty samples of muscle tissue from sarcopenic patients (mean age 63.4 ± 8.1 years) and 20 age- and sex-matched control tissues (62.1 ± 7.9 years) were acquired from the edge of dissected pronator quadratus muscle during surgery for distal radius fractures. The mRNA expression levels of VDR as well as the myokines of interest that may be associated with muscle mass change (myogenin and myostatin) were analyzed with real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). In addition, Western blot assay and immunohistochemistry for VDR were performed. Sarcopenic patients showed a significantly lower level of gene expression for VDR and myogenin, but a greater level of gene expression for myostatin than the controls according to qRT-PCR analysis. The density of VDR protein expressions was 2.1 times greater, while that of myostatin was 2.6 times lower, in the control group than in the sarcopenic group according to Western blot analysis. On immunohistochemical analysis, the density of the cells expressing VDR was significantly decreased in the sarcopenic patients. Sarcopenic patients who sustained distal radius fractures presented lower vitamin D receptor gene and protein expression in skeletal muscles compared to non-sarcopenic individuals.

Characterization of trabecular bone microstructure in premenopausal women with distal radius fractures.

Individual trabecular segmentation was utilized to identify differences in trabecular bone structure in premenopausal women with wrist fractures and non-fracture controls. Fracture subjects had reduced trabecular plate volume, number, thickness, and connectivity. Identifying altered trabecular microarchitecture in young women offers opportunities for counseling and lifestyle modifications to reduce fracture risk. INTRODUCTION: Premenopausal women with distal radius fractures (DRF) have worse trabecular bone microarchitecture than non-fracture controls (CONT), yet the characteristics of their trabecular bone structure are unknown. METHODS: Premenopausal women with DRF (n = 40) and CONT (n = 80) were recruited. Primary outcome variables included trabecular structure at the distal radius and tibia, assessed by volumetric decomposition of individual trabecular plates and rods from high-resolution peripheral quantitative CT images. Trabecular morphology included plate and rod number, volume, thickness, and connectivity. Areal bone mineral density (aBMD) of the femoral neck (FN aBMD), and ultradistal radius (UDR aBMD) were measured by DXA. RESULTS: Trabecular morphology differed between DRF and CONT at the radius and tibia (OR per SD decline 1.58-2.7). At the radius, associations remained significant when adjusting for age and FN aBMD (ORs = 1.76-3.26) and age and UDR aBMD (ORs = 1.72-3.97). Plate volume fraction, number and axially aligned trabeculae remained associated with DRF after adjustment for trabecular density (ORs = 2.55-2.85). Area under the curve (AUC) for discriminating DRF was 0.74 for the proportion of axially aligned trabeculae, compared with 0.60 for FN aBMD, 0.65 for UDR aBMD, and 0.69 for trabecular density. Plate number, plate-plate junction, and axial bone volume fraction remained associated with DRF at the tibia (ORs = 2.14-2.77) after adjusting for age, FN aBMD, or UDR aBMD. AUCP.P.Junc.D was 0.72 versus 0.61 for FNaBMD, 0.66 for UDRaBMD, and 0.70 for trabecular density. CONCLUSION: Premenopausal women with DRF have lower trabecular plate volume, number, thickness, and connectivity than CONT. Identification of young women with altered microarchitecture offers opportunities for lifestyle modifications to reduce fracture risk.

The evaluation of the sensitivity and specificity of wrist examination findings for predicting fractures.

BACKGROUND: The aim of this study was to evaluate the sensitivity and specificity of physical examination findings and functional tests in adult acute wrist trauma patients who presented to the emergency department (ED) and to create a reliable and practical clinical decision rule for determining the necessity of radiography in wrist trauma. METHODS: This prospective observational study was conducted in a tertiary ED. Each patient was checked for 18 physical examination findings and functional tests. Patients with suspected fracture were enrolled consecutively. Antero-posterior and lateral wrist views were performed for each patient. All radiographical studies were interpreted by an orthopedic surgeon. The prevalence, sensitivity and specificity, negative and positive predictive values of each finding were calculated. A modeling for predicting fractures was created using computer. RESULTS: 207 patients were evaluated and 69 patients (33.3%) had fractures. The most common encounterd fracture site was distal radius (29.5%). The most sensitive examination finding was pain in dorsiflexion (95.7%) and the most specific finding was ecchymosis (97.8%). Wrist edema, deformity and pain aggravated by pronation were found to be strong predictors of fracture. The area under the receiver operating characteristic curve at internal validation for a prediction model based on these three predictors was 0.88 (95% CI: 0.83-0,93). The overall sensitivity and specificity of this model were 94% (95% CI: 85-98%) and 51% (95% CI 43-60%) respectively. According to the model created in this study, 34% of acute blunt wrist trauma patients do not require any X-ray imaging. CONCLUSIONS: This triple modeling may be used as an effective decision rule for predicting all wrist fractures in the ED and in the disaster setting.

The Sigmoid Notch View for Distal Radius Fractures.

PURPOSE: This study defines the sigmoid notch view of the distal radius. Specifically, we tested the null hypothesis that there is no relationship between the subchondral stripe of bone seen on a sigmoid notch view of the distal radius and the articular surface of the sigmoid notch. METHODS: We used 44 wrist specimens for anatomic and fluoroscopic analysis. We measured the articular depth of the sigmoid notch from its deepest point and classified the shape of the sigmoid notch. We then placed a radiopaque marker at the nadir of the articular surface and quantified the fluoroscopic depth of the sigmoid notch. A sigmoid notch view, which was a tangential fluoroscopic view of the volar and dorsal lips of the sigmoid notch, was obtained. The relationship of the articular surface to the stripe of subchondral bone seen on this view, called the sigmoid stripe, was determined. RESULTS: Anatomic analysis revealed sigmoid notch types with proportions similar to those in previous descriptions. The marker for the articular surface was superimposed or just ulnar to the sigmoid stripe in all specimens. In flat face and ski slope notches, this was coincident with the volar and dorsal lips of the sigmoid notch. In C- and S-type notches, there was a measurable distance from the articular surface marker to the edges of the bone of the volar and dorsal lips of the sigmoid. CONCLUSIONS: The articular surface marker at the nadir of the sigmoid notch is always coincident or ulnar to the sigmoid stripe in the sigmoid notch view. CLINICAL RELEVANCE: Surgeons can use the sigmoid notch view as a reliable method to (1) evaluate the integrity of the articular surface, (2) ensure hardware is not placed in the distal radioulnar joint, and (3) guide placement of volar locking plates in the coronal plane.

Evaluation of Bone Atrophy After Treatment of Forearm Fracture Using Nonlinear Finite Element Analysis: A Comparative Study of Locking Plates and Conventional Plates.

PURPOSE: Forearm diaphysis fractures are usually managed by open reduction internal fixation. Recently, locking plates have been used for treatment. In the long-term period after surgery, some patients present with bone atrophy adjacent to the plate. However, a comparison of locking and conventional plates as a cause of atrophy has not been reported. The aim of this study was to investigate long-term bone atrophy associated with use of locking and conventional plates for forearm fracture treatment. METHODS: In this study we included 15 patients with forearm fracture managed by either locking or conventional plates and with more than 5 years of follow-up. Computed tomographic imaging of both forearms was performed to assess bone thickness and local bone mineral density and to predict bone strength without plate reinforcement based on finite element analysis. RESULTS: Mean patient age at surgery was 48.0 years. Eight patients underwent reduction with fixed locking plates and were followed up for a mean of 79.5 months; the remaining 7 patients were treated with conventional plates and were followed up for a mean of 105.0 months. Compared with the conventional plate group, the locking plate group had the same fractured limb-contralateral limb ratio of cortex bone thickness, but had significantly lower ratios of mineral density adjacent to the plate and adjusted bone strength. CONCLUSIONS: This study demonstrated bone atrophy after locking plate fixation for forearm fractures. Treatment plans for forearm fracture should take into consideration the impact of bone atrophy long after plate fixation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Delayed Fracture Healing in Diabetics with Distal Radius Fractures.

PURPOSE OF THE STUDY Diabetics may have an increased fracture risk, depending on disease duration, quality of metabolic adjustment and extent of comorbidities, and on an increased tendency to fall. The aim of this retrospective one-centre study consisted in detecting differences in fracture healing between patients with and without diabetes mellitus. Data of patients with the most common fracture among older patients were analyzed. MATERIAL AND METHODS Classification of distal radius fractures was established according to the AO classification. Inital assessment and followup were made by conventional x-rays with radiological default settings. To evaluate fracture healing, formation of callus and sclerotic border, assessment of the fracture gap, and evidence of consolidation signs were used. RESULTS The authors demonstrated that fracture morphology does not influence fracture healing regarding time span, neither concerning consolidation signs nor in fracture gap behavior. However, tendency for bone remodeling is around 70% lower in investigated diabetics than in non-diabetics, while probability for a successful fracture consolidation is 60% lower. CONCLUSIONS To corroborate the authors hypothesis of delayed fracture healing in patients with diabetes mellitus, prospective studies incorporating influencing factors like duration of metabolic disease, quality of diabetes control, medical diabetes treatment, comorbidities and secondary diseaseas, like chronic nephropathy and osteoporosis, have to be carried out. Key words: diabetes, delayed fracture healing, distal radius fractures, callus formation, blood glucose level, osteoblasts.

Evaluation of trabecular bone score in patients with a distal radius fracture.

We compared bone mineral density (BMD) and trabecular bone score (TBS) in postmenopausal women with a distal radius fracture older than 50 years with controls. Total hip BMD was significantly different, but TBS was not different between two groups, suggesting TBS does not reflect microarchitectural changes of the distal radius. INTRODUCTION: The purpose of this study was to determine whether trabecular bone score (TBS) has additive value for discriminating distal radius fracture (DRF) independent of BMD. METHODS: We compared BMD and TBS in 258 postmenopausal women with a DRF older than 50 years of age with age- and body mass index (BMI)-matched controls who had no history of osteoporotic fracture. BMD was measured at the lumbar spine and hip using dual energy X-ray absorptiometry scans (GE Lunar Prodigy). TBS was calculated on the same spine image. A multivariate logistic regression analysis was used to analyze the odds ratio (OR) for the occurrence of DRF using age, BMI, lumbar spine BMD, total hip BMD, and TBS. RESULTS: Patients with a DRF had significantly lower BMDs at hip (neck, trochanter and total) than those of controls: 0.752 ± 0.097, 0.622 ± 0.089, and 0.801 ± 0.099 in patients and 0.779 ± 0.092, 0.648 ± 0.089, 0.826 ± 0.101 in controls. However, lumbar spine BMD and TBS were not significantly different between the groups (p = 0.400 and 0.864, respectively). The multivariate analysis indicated that only total hip BMD was significantly associated with the occurrence of DRF (OR, 10.231; 95 % confidence interval, 1.724-60.702; p = 0.010). CONCLUSIONS: TBS was not different between women with a DRF and those without a history of osteoporotic fracture, suggesting that TBS measured at the lumbar spine does not reflect early microarchitectural changes of the distal radius. Only total hip BMD is associated with the risk of DRF in Korean women.

Relationship Between Ulnar Variance, Cortical Bone Density, and Load to Failure in the Distal Radius at the Typical Site of Fracture Initiation.

PURPOSE: Increased ulnar variance has been shown to lead to diminished load borne by the distal radius. The purpose of this study was to determine the correlations among ulnar variance, bone mineral density, and load to failure at the distal radius. METHODS: Posteroanterior radiographs and computed tomographic scans were taken of 12 cadaveric forearms in neutral rotation. Ulnar variance was measured for each wrist by the method of perpendiculars. Measurements of cortical, trabecular, and combined bone density were made at the distal radius. We performed linear regression analysis and correlation analysis to determine the relationship between bone densities and ulnar variance measurements. Next, we loaded the 12 cadaveric radii to failure under axial compression. Linear regression analysis and correlation analysis were then performed to determine the relationship between load to failure and both ulnar variance and cortical density. RESULTS: Increased ulnar variance was significantly correlated with decreased cortical bone density at the distal radius and both were correlated with decreased load to failure. We found no correlation between ulnar variance and trabecular density or combined trabecular and cortical bone density at the distal radius. CONCLUSIONS: Our study found that increased ulnar variance and decreased cortical bone mineral density correlates with decreased load to failure under axial compression. CLINICAL RELEVANCE: Ulnar variance is linked to both bone quality and load to failure at the distal radius.

Clinical and radiologic factors affecting functional outcomes after volar locking plate fixation of dorsal angulated distal radius fractures.

BACKGROUND: The aim of the present study was to identify the clinical and radiologic factors affecting functional outcomes in patients with a distal radius fractures (DRFs) treated by volar locking plate fixation. PATIENTS AND METHODS: Prospective cohort of patients with dorsally angulated DRFs requiring the volar locking plate fixation were recruited during one year. We evaluated wrist motion, grip strength, and DASH score at 3, 6 and 12 months after surgery. The factors assessed for their influence on functional outcomes included clinical variables representing patients' characteristics (age, gender, whether the dominant hand was fractured, the fracture mechanism, fracture classification, complications after surgery, and diabetes mellitus) and radiologic variables representing amount of displacement and quality of reduction (volar tilt angle, radial height, radial inclination, and ulnar variance) at initial injury plain radiographs before manual reduction, and at the radiographs within 1 week of surgery. We conducted a simple and multiple linear regression analysis to identify the clinical and radiologic factors affecting functional outcomes. RESULTS: 89 patients were recruited at 1 year after surgery. In the multivariate linear regression analysis, the significant factor affecting DASH score was diabetes (p = 0.025) and the ulnar variance after surgery (p = 0.042) after adjusting for age. However, Age was the only statistically significant factor affected grip strength (p = 0.024) and wrist motion (p = 0.012). CONCLUSIONS: Because the ulnar variance after surgery is the modifiable factor in contrast with other factors such as diabetes and age, surgeons should pay attention to restore ulnar variance to improve functional outcomes during volar locking plate fixation in patients with distal radius fractures.

Bone strength and muscle properties in postmenopausal women with and without a recent distal radius fracture.

UNLABELLED: Distal radius (wrist) fracture (DRF) in women over age 50 years is an early sign of bone fragility. Women with a recent DRF compared to women without DRF demonstrated lower bone strength, muscle density, and strength, but no difference in dual-energy x-ray absorptiometry (DXA) measures, suggesting DXA alone may not be a sufficient predictor for DRF risk. INTRODUCTION: The objective of this study was to investigate differences in bone and muscle properties between women with and without a recent DRF. METHODS: One hundred sixty-six postmenopausal women (50-78 years) were recruited. Participants were excluded if they had taken bone-altering medications in the past 6 months or had medical conditions that severely affected daily living or the upper extremity. Seventy-seven age-matched women with a fracture in the past 6-24 months (Fx, n = 32) and without fracture (NFx, n = 45) were measured for bone and muscle properties using the nondominant (NFx) or non-fractured limb (Fx). Peripheral quantitative computed tomography (pQCT) was used to estimate bone strength in compression (BSIc) at the distal radius and tibia, bone strength in torsion (SSIp) at the shaft sites, muscle density, and area at the forearm and lower leg. Areal bone mineral density at the ultradistal forearm, spine, and femoral neck was measured by DXA. Grip strength and the 30-s chair stand test were used as estimates of upper and lower extremity muscle strength. Limb-specific between-group differences were compared using multivariate analysis of variance (MANOVA). RESULTS: There was a significant group difference (p < 0.05) for the forearm and lower leg, with the Fx group demonstrating 16 and 19% lower BSIc, 3 and 6% lower muscle density, and 20 and 21% lower muscle strength at the upper and lower extremities, respectively. There were no differences between groups for DXA measures. CONCLUSIONS: Women with recent DRF had lower pQCT-derived estimated bone strength at the distal radius and tibia and lower muscle density and strength at both extremities.

The effect of fracture comminution on the reliability and accuracy of radial head sizing.

BACKGROUND: Radial head implant sizing can be based on the maximum head diameter (D-MAX), the minimum head diameter (D-MIN), or the articular dish diameter (D-DISH). The purpose of this study was to assess the reliability of the different radial head sizing techniques and to investigate the effect of radial head fracture comminution on measurement accuracy. METHODS: Ten observers measured 11 cadaveric radial heads with 3 radial head features (D-MAX, D-MIN, and D-DISH diameter). Radial heads were then fractured into 2, 3, and 4 parts, and the measurements were repeated. Variability was assessed by intraclass correlation. The measurements were compared with the intact state to assess the effect of radial head fracture comminution on sizing accuracy. RESULTS: D-MAX and D-MIN measurements were the most reliable among all observers (intraclass correlation coefficients, 0.980, 0.973). The D-DISH measurement was less reliable (intraclass correlation coefficient, 0.643). Radial head comminution did not significantly affect the reliability of any measurement (P > .2). Fracture comminution, however, significantly affected measurement accuracy with D-MAX and D-DISH. With fracture comminution, D-MAX underestimated radial head diameter (-0.4 ± 0.3 mm; P < .001), whereas D-DISH overestimated diameter (+0.5 ± 0.4 mm; P < .001). Comminution did not significantly affect D-MIN (-0.1 ± 0.3 mm; P = .13). DISCUSSION: The D-MAX and D-MIN measurements were more reliable than D-DISH for diameter sizing of intact and comminuted radial heads. Overall, increasing comminution did not significantly affect measurement reliability. However, the accuracy of the D-MIN technique was least affected by comminution, suggesting that D-MIN should be used in selecting the diameter of a radial head implant.

Preparation of porous PLA/DBM composite biomaterials and experimental research of repair rabbit radius segmental bone defect.

Bone substitutes are used in wide range of orthopaedic application. An ideal bone substitute should exhibit superior osteoinductive and osteoconductive properties. Neither bio-derived materials nor synthetic materials can meet the needs of an ideal bone substitute. Preparation of composite materials is a promising way to improve properties of biomaterial. In this study, the porous poly lactic acid (PLA)/demineralized bone matrix (DBM) composite biomaterials prepared by supercritical CO2 technique were implanted to repair rabbit radius segmental bone defect. By comparing with PLA and bone autograft, the X-ray result and histological analysis showed the repair effect of PLA/DBM porous composite materials is significantly better than that of the PLA group and the blank control group, and is similar to autologous bone. The PLA/DBM can promote the healing of bone defects and can be used as a kind of ideal alternative materials to repair bone defects.

Complex proximal ulna fractures: outcomes of surgical treatment.

BACKGROUND: To review the results of plating of various fracture patterns of proximal ulna fractures including isolated olecranon fractures, olecranon fractures combined with a coronoid fracture, and olecranon fractures combined with a coronoid and radial head fracture. MATERIALS AND METHODS: The study included 38 patients with either an isolated olecranon fracture or combined injuries, all treated with open reduction and internal fixation of the olecranon. Other procedures were performed as needed, including radial head fixation or arthroplasty, fixation of the coronoid, and repair of the lateral collateral ligament complex. There were 27 men and 11 women with an average age of 49 years. Clinical and radiographic assessment was obtained at an average follow-up time of 15 and 8.4 months, respectively. RESULTS: All fractures healed within 5 months. The average arc of ulnohumeral motion was 91° (range 0°-140°); average pronation-supination arc was 128° (range 0°-180°). Subgroup analysis showed a statistically significant lower rotational motion arc in patients with associated radial head (73°) or coronoid fractures (68°) compared to isolated olecranon fractures. All other parameters including ulnohumeral motion, complication rate, and revision rate were similar among the groups. CONCLUSIONS: A stable, functional elbow can be restored in most patients with proximal ulna fractures treated with open reduction and internal fixation. Loss of full flexion is likely with high-energy trauma, complex fracture patterns, and concomitant injuries. Fracture patterns involving the coronoid and/or the radial head are associated with restricted forearm rotation. LEVEL OF EVIDENCE: III.

Successful human long-term application of in situ bone tissue engineering.

Tissue Engineering (TE) and Regenerative Medicine (RM) have gained much popularity because of the tremendous prospects for the care of patients with tissue and organ defects. To overcome the common problem of donor-site morbidity of standard autologous bone grafts, we successfully combined tissue engineering techniques for the first time with the arteriovenous loop model to generate vascularized large bone grafts. We present two cases of large bone defects after debridement of an osteomyelitis. One of the defects was localized in the radius and one in the tibia. For osseus reconstruction, arteriovenous loops were created as vascular axis, which were placed in the bony defects. In case 1, the bone generation was achieved using cancellous bone from the iliac crest and fibrin glue and in case 2 using a clinically approved ß-tricalciumphosphate/hydroxyapatite (HA), fibrin glue and directly auto-transplanted bone marrow aspirate from the iliac crest. The following post-operative courses were uneventful. The final examinations took place after 36 and 72 months after the initial operations. Computer tomogrphy (CT), membrane resonance imaging (MRI) and doppler ultrasound revealed patent arterio-venous (AV) loops in the bone grafts as well as completely healed bone defects. The patients were pain-free with normal ranges of motion. This is the first study demonstrating successfully axially vascularized in situ tissue engineered bone generation in large bone defects in a clinical scenario using the arteriovenous loop model without creation of a significant donor-site defect utilizing TE and RM techniques in human patients with long-term stability.

Novel microhydroxyapatite particles in a collagen scaffold: a bioactive bone void filler?

BACKGROUND: Treatment of segmental bone loss remains a major challenge in orthopaedic surgery. Traditional techniques (eg, autograft) and newer techniques (eg, recombinant human bone morphogenetic protein-2 [rhBMP-2]) have well-established performance limitations and safety concerns respectively. Consequently there is an unmet need for osteoinductive bone graft substitutes that may eliminate or reduce the use of rhBMP-2. QUESTIONS/PURPOSES: Using an established rabbit radius osteotomy defect model with positive (autogenous bone graft) and negative (empty sham) control groups, we asked: (1) whether a collagen-glycosaminoglycan scaffold alone can heal the defect, (2) whether the addition of hydroxyapatite particles to the collagen scaffold promote faster healing, and (3) whether the collagen-glycosaminoglycan and collagen-hydroxyapatite scaffolds are able to promote faster healing (by carrying a low dose rhBMP-2). METHODS: A 15-mm transosseous radius defect in 4-month-old skeletally mature New Zealand White rabbits were treated with either collagen-hydroxyapatite or collagen-glycosaminoglycan scaffolds with and without rhBMP-2. Autogenous bone graft served as a positive control. Time-series radiographs at four intervals and postmortem micro-CT and histological analysis at 16 weeks were performed. Qualitative histological analysis of postmortem explants, and qualitative and volumetric 3-D analysis of standard radiographs and micro-CT scans enabled direct comparison of healing between test groups. RESULTS: Six weeks after implantation the collagen-glycosaminoglycan group had callus occupying greater than ½ the defect, whereas the sham (empty) control defect was still empty and the autogenous bone graft defect was completely filled with unremodeled bone. At 6 weeks, the collagen-hydroxyapatite scaffold groups showed greater defect filling with dense callus compared with the collagen-glycosaminoglycan controls. At 16 weeks, the autogenous bone graft groups showed evidence of early-stage medullary canal formation beginning at the proximal and distal defect borders. The collagen-glycosaminoglycan and collagen-glycosaminoglycan-rhBMP-2 groups had nearly complete medullary canal formation and anatomic healing at 16 weeks. However, collagen-hydroxyapatite-rhBMP-2 scaffolds showed the best levels of healing, exhibiting a dense callus which completely filled the defect. CONCLUSIONS: The collagen-hydroxyapatite scaffold showed comparable healing to the current gold standard of autogenous bone graft. It also performed comparably to collagen-glycosaminoglycan-rhBMP-2, a representative commercial device in current clinical use, but without the cost and safety concerns. CLINICAL RELEVANCE: The collagen-glycosaminoglycan scaffold may be suitable for a low load-bearing defect. The collagen-hydroxyapatite scaffold may be suitable for a load-bearing defect. The rhBMP-2 containing collagen-glycosaminoglycan and collagen-hydroxyapatite scaffolds may be suitable for established nonunion defects.