Total Hip Arthroplasty Leads to Better Results After Low-Energy Displaced Femoral Neck Fracture in Patients Aged 55 to 70 Years: A Randomized Controlled Multicenter Trial Comparing Internal Fixation and Total Hip Arthroplasty.

BACKGROUND: The optimal treatment of displaced femoral neck fractures in patients 55 to 70 years old remains controversial. The aim of the present study was to assess the effect of closed reduction and internal fixation with cannulated screws (IF) compared with total hip arthroplasty (THA) on hip pain and function, with use of data for outcome measures, complications, and reoperations. METHODS: This multicenter randomized controlled trial included all patients 55 to 70 years old who presented with a low-energy displaced femoral neck fracture between December 2013 and December 2018. Patients were randomly allocated to undergo either IF or THA. The primary outcome was the Harris Hip Score (HHS) at 12 months postoperatively. Secondary outcomes were the HHS at 4 and 24 months postoperatively, Oxford Hip Score (OHS), Hip Disability and Osteoarthritis Outcome Score (HOOS), health-related quality of life (EQ-5D-3L [EuroQol 5 Dimensions 3 Levels] index score and EQ-VAS [visual analogue scale]), VAS for pain, and VAS for patient satisfaction at 4, 12, and 24 months postoperatively. Complications and reoperations were continuously monitored. The primary analyses were performed according to the intention-to-treat principle. RESULTS: A total of 102 patients with a mean (± standard deviation) age of 63.7 ± 4.2 years were allocated to IF (n = 51) or THA (n = 51). The mean difference in the primary outcome, the HHS at 12 months postoperatively (5.3; 95% confidence interval, 0.9 to 9.7; p = 0.017), was below the predefined minimal clinically important difference of 10 points. However, patients who underwent THA had a significantly higher HHS at 4 and 12 months, better OHS at 4 and 12 months, and better HOOS at 4, 12, and 24 months postoperatively. Patients who underwent THA also reported better health-related quality of life at 4 months postoperatively and reported greater satisfaction and less pain at 4 and 12 months postoperatively. A total of 26 patients in the IF group (51%; 95% confidence interval, 37% to 65%) and 2 patients in the THA group (4%; 95% confidence interval, 0.5% to 13%) underwent a major reoperation. CONCLUSIONS: In this randomized controlled trial, we showed that patients between 55 and 70 years old who underwent THA for a low-energy displaced femoral neck fracture experienced better outcomes than those who underwent closed reduction and internal fixation. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Functional outcome 3-6 years after operative treatment of closed Weber B ankle fractures with or without syndesmotic fixation.

BACKGROUND: To compare the long-term functional outcomes of patients surgically treated for Weber B ankle fractures with or without syndesmotic fixation. METHODS: In total, 959 adult patients with previous treatment with open reduction and internal fixation (ORIF) for closed ankle fractures were eligible for inclusion in a cross-sectional postal survey 3-6 years after surgery; 645 had Weber B fractures. The survey assessed functional outcomes with three validated ankle questionnaires. RESULTS: In total 365 (57%) patients responded at a median of 4.2 years after the trauma. After adjusting for age, sex, education, smoking status, body mass index, diabetes, physical status before surgery, fracture classification, and duration of surgery, patients with a syndesmotic fixation had no different OMAS score (p = 0.98), LEFS score (p = 0.61), and SEFAS score (p = 0.98) than those without a syndesmotic fixation. Trimalleolar fracture was associated with worse functional outcomes than unimalleolar on two of the scales, the OMAS (p = 0.028) and LEFS (p = 0.046). CONCLUSIONS: In multivariable analysis, patients with a syndesmotic fixation had no worse long-term functional outcomes than those without syndesmotic fixation.

Risk factors for symptomatic venous thromboembolism following surgery for closed ankle fractures: A case-control study.

BACKGROUND: We analyzed risk factors for venous thromboembolism (VTE) within 6 months after surgery for closed ankle fractures. METHODS: This was a case-control study based on data from chart review in a cohort of patients having open reduction and internal fixation (ORIF) for closed ankle fractures in two large general hospitals 2009-2011. Cases with symptomatic VTE (pulmonary embolism or deep venous thrombosis) were identified in the cohort, and additional cases of VTE were identified by computerized search of discharge diagnoses in the same hospitals in 2004-2008 and 2012-2016. In total, we identified 60 cases with VTE and compared with 240 randomly selected controls among 998 patients without VTE in the cohort. Risk factors were assessed using logistic regression analysis. RESULTS: Among cases, 27 (45%) had pulmonary embolism, 33 (55%) deep venous thrombosis. Those with VTE were older, had higher BMI, had more often a family history of VTE, and more often had antibiotic prophylaxis during surgery than controls. In multivariable logistic regression analysis age/10 (OR 25.75, 95%CI 3.52-188.44, p=0.001), (age/10)2 (OR 0.77, 95%CI 0.65-0.93, p=0.005), BMI (1.15 per kg/m2, 95%CI 1.07-1.24, p<0.001) and Charlson comorbidity index ≥2 vs.0 (OR 0.27, 95%CI 0.08-0.92, p=0.036) and 1 vs. 0 (OR 0.27, 95%CI 0.09-0.86, p=0.026) were associated with VTE within 6 months of surgery. CONCLUSIONS: The odds of symptomatic VTE within 6 months of ORIF increased with increasing age and BMI, but were lower with increasing comorbidity.

Low bone density and high morbidity in patients between 55 and 70 years with displaced femoral neck fractures: a case-control study of 50 patients vs 150 normal controls.

BACKGROUND: A displaced femoral neck fracture (FNF) in patients 55-70 years is a serious injury with a high risk of treatment failure and the optimal surgical treatment remains unclear. We aimed to describe characteristics of fracture patients compared to a sample from the normal population. METHODS: Fifty patients aged 55-70 years with a displaced FNF were gender- and age- matched with a control group of 150 persons without a hip fracture using computergenerated randomization and the Norwegian National Population Register. To reduce the risk of spurious selection bias, the sample size of the control group was trebled compared to the fracture group. Dual-energy x-ray absorptiometry (DXA) was performed. Demographics and hip function (Harris Hip Score, Oxford Hip Score, and Hip Dysfunction and Osteoarthritis Outcome Score) were collected. RESULTS: There were more than 75% women in both groups. The mean age was 64.5 years in the fracture group and 65.1 in the control group. Results for DXA measured for lumbar spine, total hip and the femoral neck showed that patients with displaced FNF were significantly more osteoporotic. Fracture patients had significantly lower body mass index, higher Charlson comorbidity index (CCI), and higher ASA (American Society of Anesthesiologists) score than the control group. No clinically relevant differences in hip function were found. There were 48% smokers in the fracture group compared to 10% in the control group. The odds ratio for obtaining a displaced FNF was high if the patients suffered from osteoporosis, smoked or had several comorbidities. CONCLUSIONS: This study showed that patients aged 55-70 years with a displaced femoral neck fracture had lower bone density and higher comorbidity compared with a gender- and age-matched population without femoral neck fractures. This suggests that this patient group is epidemiologically similar to older patients with femoral neck fractures.

Cross-Table Lateral Radiographs Accurately Predict Displacement in Valgus-Impacted Femoral Neck Fractures.

BACKGROUND: Femoral neck fractures are classified as nondisplaced (Garden types I and II) or displaced (Garden types III and IV) on the basis of anteroposterior radiographs. Cross-table lateral radiographs are important in the assessment of Garden type-I and II fractures as posterior tilt of the femoral head may influence treatment results. A posterior tilt of >20° has been associated with an increased risk of treatment failure after internal fixation, although the precision of these measurements has not been validated. Therefore, the purpose of the present study was to compare cross-table lateral radiographs with 3-dimensional computed tomographic (3D-CT) reconstructions of Garden type-I and II femoral neck fractures. METHODS: Twenty-three patients presenting with Garden type-I and II femoral neck fractures that were verified on anteroposterior radiographs underwent CT scanning immediately after radiographic examination. 3D models of the fractured and uninjured femora were reconstructed from the CT images, and displacement of the 3D models was determined by superimposing the fractured and uninjured femora. We defined a coordinate system with its origin at the center of the uninjured femoral head with the x axis oriented medially; the y axis, posteriorly; and the z axis, cranially. Correlations between lateral radiographs and 3D models were assessed with the Spearman rank coefficient, mean difference, and limits of agreement. RESULTS: Posterior tilt of the femoral head on lateral radiographs was strongly correlated with displacement of the femoral head along the y axis of the 3D models, with a correlation coefficient of 0.86 (p < 0.001). Correlations between the findings on lateral radiographs and displacements along the x or z axis were weak, with coefficients of -0.30 (p = 0.18) and 0.21 (p = 0.34), respectively. The mean difference between displacement on lateral radiographs and displacement along the y axis of the 3D models was smaller, and demonstrated a smaller limits-of-agreement interval, compared with the x or z axis. CONCLUSIONS: Our results demonstrated a strong correlation between posterior displacement of the femoral head on lateral radiographs and displacement along the y axis in 3D models of Garden type-I and II femoral neck fractures. This finding indicates that lateral radiographs provide an accurate assessment of posterior tilt.

Screw Fixation Versus Hemiarthroplasty for Nondisplaced Femoral Neck Fractures in Elderly Patients: A Multicenter Randomized Controlled Trial.

BACKGROUND: Elderly patients with a displaced femoral neck fracture treated with hip arthroplasty may have better function than those treated with internal fixation. We hypothesized that hemiarthroplasty would be superior to screw fixation with regard to hip function, mobility, pain, quality of life, and the risk of a reoperation in elderly patients with a nondisplaced femoral neck fracture. METHODS: In a multicenter randomized controlled trial (RCT), Norwegian patients ≥70 years of age with a nondisplaced (valgus impacted or truly nondisplaced) femoral neck fracture were allocated to screw fixation or hemiarthroplasty. Assessors blinded to the type of treatment evaluated hip function with the Harris hip score (HHS) as the primary outcome as well as on the basis of mobility assessed with the timed "Up & Go" (TUG) test, pain as assessed on a numerical rating scale, and quality of life as assessed with the EuroQol-5 Dimension-3 Level (EQ-5D) at 3, 12, and 24 months postsurgery. Results, including reoperations, were assessed with intention-to-treat analysis. RESULTS: Between February 6, 2012, and February 6, 2015, 111 patients were allocated to screw fixation and 108, to hemiarthroplasty. At the time of follow-up, there was no significant difference in hip function between the screw fixation and hemiarthroplasty groups, with a 24-month HHS (and standard deviation) of 74 ± 19 and 76 ± 17, respectively, and an adjusted mean difference of -2 (95% confidence interval [CI] = -6 to 3; p = 0.499). Patients allocated to hemiarthroplasty were more mobile than those allocated to screw fixation (24-month TUG = 16.6 ± 9.5 versus 20.4 ± 12.8 seconds; adjusted mean difference = 6.2 seconds [95% CI = 1.9 to 10.5 seconds]; p = 0.004). Furthermore, screw fixation was a risk factor for a major reoperation, which was performed in 20% (22) of 110 patients who underwent screw fixation versus 5% (5) of 108 who underwent hemiarthroplasty (relative risk reduction [RRR] = 3.3 [95% CI = 0.7 to 10.0]; number needed to harm [NNH] = 6.5; p = 0.002). The 24-month mortality rate was 36% (40 of 111) for patients allocated to internal fixation and 26% (28 of 108) for those allocated to hemiarthroplasty (RRR = 0.4 [95% CI = -0.1 to 1.1]; p = 0.11). Two patients were lost to follow-up. CONCLUSIONS: In this multicenter RCT, hemiarthroplasty was not found to be superior to screw fixation in reestablishing hip function as measured by the HHS (the primary outcome). However, hemiarthroplasty led to improved mobility and fewer major reoperations. The findings suggest that certain elderly patients with a nondisplaced femoral neck fracture may benefit from being treated with a latest-generation hemiarthroplasty rather than screw fixation. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Evaluation of three patient reported outcome measures following operative fixation of closed ankle fractures.

BACKGROUND: Several patient reported outcome measures (PROMs) are available for assessing the outcomes of ankle fracture but few have been compared for recommended measurement properties. This study compares the measurement properties of the Lower Extremity Function Scale (LEFS), Olerud Molander Ankle Score (OMAS) and Self-Reported Foot and Ankle Score (SEFAS) following ankle surgery. METHODS: The retrospective cohort study included 959 patients aged 18 years and over who underwent surgical treatment (ORIF) for unstable and closed ankle fractures in SE Norway. The PROMs were included in a postal questionnaire sent to patients' homes in 2015, three years after surgery. Missing data, structural validity, internal consistency, test-retest reliability and validity were assessed. RESULTS: Confirmatory factor analysis results showed model fit for the SEFAS and a bi-dimensional LEFS with scales of easy and difficult items. The OMAS performed less satisfactorily. Cronbach's alpha and test-retest correlations ranged from 0.82 to 0.96 and 0.91 to 0.93 respectively. The smallest detectable differences for group and individual comparisons were 14.1 to 20.6 and 0.93 to 1.55; SEFAS performed best. As hypothesised, instrument scores were highly correlated and with those for the EQ-5D and SF-36 physical functioning. Mean imputation where half or more items are completed increased usable scores by 1.4-15.7% without affecting measurement properties. CONCLUSIONS: The three instruments largely performed satisfactorily in relation to important measurement properties but the LEFS had evidence for two dimensions relating to easier and more difficult aspects of function. Mean imputation where half or more items are completed increased the number of usable responses for all three instruments. The three instruments represent different approaches to measuring outcomes and their content should be considered carefully when choosing between them. The SEFAS is designed for a range of foot disorders including ankle fractures and has the best measurement properties in this population.

High failure rate after internal fixation and beneficial outcome after arthroplasty in treatment of displaced femoral neck fractures in patients between 55 and 70 years.

Background and purpose - The treatment of patients between 55 and 70 years with displaced intracapsular femoral neck fracture remains controversial. We compared internal fixation (IF), bipolar hemiarthroplasty (HA) and total hip arthroplasty (THA) in terms of mortality, reoperations and patient-reported outcome by using data from the Norwegian Hip Fracture Register. Patients and methods - We included 2,713 patients treated between 2005 and 2012. 1,111 patients were treated with IF, 1,030 with HA and 572 patients with THA. Major reoperations (defined as re-osteosynthesis, secondary arthroplasty, exchange, or removal of prosthesis components and Girdlestone procedure), patient-reported outcome measures (satisfaction, pain, and health-related quality of life (EQ5D) after 4 and 12 months), 1-year mortality, and change in treatment methods over the study period were investigated. Results - Major reoperations occurred in 27% after IF, 3.8% after HA and 2.8% after THA. 549 patients (20% of total study population) answered both questionnaires. Compared with IF, patients treated with THA were more satisfied after 4 and 12 months, reported less pain after 4 months and 12 months, had a higher EQ5D-index score after 4 months and 12 months, and EQ-VAS score after 4 months. Compared with IF, patients treated with HA were more satisfied and reported less pain after 4 months. EQ5D-index and EQ-VAS were similar. Patients treated with HA had higher 1-year mortality and had more comorbidities than both the THA and IF group. All these differences were statistically and clinically significant. Interpretation - This study showed high reoperation rate after IF and better patient-reported outcome after both THA and HA with medium follow-up. Patients selected for HA represented a frailer group than patients treated with THA or IF.

Five-Year Follow-up Results of a Randomized Controlled Study Comparing Intramedullary Nailing with Plate Fixation of Completely Displaced Midshaft Fractures of the Clavicle in Adults.

BACKGROUND: Surgical management of completely displaced midshaft fractures of the clavicle is becoming more frequent, although long-term follow-up with Level-I evidence is scarce. Plate fixation (PF) of comminuted fractures provides faster functional recovery than elastic stable intramedullary nailing (ESIN). The 12-month follow-up of this randomized controlled trial, published previously, found no clinical differences at that time on the group level, but subtle differences on the subgroup level indicated that the results after closed ESIN were better than those after open ESIN. The primary aim of the study reported here was to compare the long-term clinical outcomes and sequelae after open reduction with those after closed reduction and to help surgeons develop a treatment strategy of either PF or ESIN for selected patients. METHODS: At a median follow-up of 66 months (range, 49 to 89 months), the 123 patients in the original study were invited to an online secure survey. We used the survey results to compare the PF and ESIN treatment arms and to perform predetermined subgroup analyses of closed compared with open ESIN in relation to Disabilities of the Arm, Shoulder and Hand (DASH) score, pain assessment, and implant removal. RESULTS: The questionnaire was completed by 114 (93%) of the 123 patients. There were no differences between the 2 treatment arms with regard to the DASH score (ESIN, 3.1 ± 7.0 and PF, 3.7 ± 7.5; p = 0.9). The 27 patients who had been treated with closed ESIN had a significantly superior DASH score compared with the 27 patients who had been treated with open ESIN (closed, 0.7 ± 1.4 and open, 5.2 ± 8.9; p = 0.015) and compared with the patients who had been treated with PF (closed ESIN, 0.7 ± 1.4 and PF, 3.9 ± 7.5; p = 0.002). Patients who had been treated with closed ESIN also reported fewer sequelae than patients who had been treated with open ESIN or PF. CONCLUSIONS: The results of this study, combined with those of our prior 1-year follow-up of the same patients, indicate that it seems to be advantageous to perform closed ESIN. The long-term results after PF were similar to those after open ESIN, but PF resulted in faster functional recovery and fewer patients needing to have the implant removed. Therefore, if open reduction is necessary for a comminuted fracture, it seems that the advantages of the minimally invasive ESIN procedure are lost, and the surgeon should consider conversion to PF. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Functional outcomes following surgical-site infections after operative fixation of closed ankle fractures.

BACKGROUND: To compare the functional outcomes between patients with and without postoperative surgical-site infection (SSI) after surgical treatment in closed ankle fractures. METHODS: Retrospective cohort study with prospective follow-up. Of 1011 treated patients, 959 were eligible for inclusion in a postal survey. Functional outcomes were assessed using three self-reported questionnaires. RESULTS: In total 567 patients responded a median of 4.3 years (range 3.1-6.2 years) after surgery. In total 29/567 had an SSI. The mean Olerud and Molander Ankle Score was 19.8 points lower for patients with a deep SSI (p=0.02), the Lower Extremity Functional Scale score was 10.2 points lower (p<0.01) and the Self-Reported Foot & Ankle Questionnaire score was 5.0 points higher (p=0.10) than for those without an SSI, after adjusting for age, sex, smoking status, diabetes, physical status, fracture classification and duration of surgery. CONCLUSIONS: Patients with a deep SSI had worse long-term functional outcomes than those without an SSI.

Association of Body Mass Index With the Pattern of Surgically Treated Ankle Fractures Using Two Different Classification Systems.

The present retrospective cohort study assessed the association of body mass index (BMI) with the pattern of ankle fractures using 2 classifications systems. Of the 1011 consecutive patients who underwent surgery for ankle fractures in 2 hospitals from January 2009 to December 2011, 837 had a classifiable fracture according to 1 of 2 classification systems and complete information available for covariates. The association of BMI, adjusted for age, sex, corticosteroid use, diabetes, and smoking status with having a more proximal fibula fracture (Weber class A to C) and an increasing number of malleoli involved (uni-, bi-, or trimalleolar) was assessed using multivariable ordered logistic regression analysis. The mean age of the patients was 50.9 ± 16.9 years, and 461 (55%) were female. On multivariable analysis, BMI and male sex were associated with having a more proximal fibula fracture using the Weber classification, with an odds ratio (OR) of 1.07 (95% confidence interval [CI] 1.04 to 1.11; p < .001) per 1 kg/m2 increase and OR of 2.96 (95% CI 2.13 to 4.11; p < .001) compared with female sex, respectively. Age was not associated with this fracture classification. In an analysis of uni-, bi-, and trimalleolar fractures, age per 10 years showed higher odds (OR 1.24, 95% CI 1.14 to 1.36; p < .001) and male sex lower odds compared with female sex (OR 0.36, 95% CI 0.27 to 0.48; p < .001) of having trimalleolar fractures than uni- or bimalleolar fractures. An increasing BMI did not seem to be a risk factor, although an inverse U-shaped relationship was seen between quintiles of BMI and the OR of having trimalleolar versus uni- or bimalleolar fractures. Corticosteroid use, diabetes, and smoking status were not significantly associated with the pattern of the ankle fractures using either classification system. In conclusion, an increasing BMI and male sex were risk factors for proximal fibula fractures, and female sex and age were risk factors for bi- and trimalleolar fractures.

Determinants of Health Status Three to Six Years After Surgical Treatment of Closed Ankle Fracture and Comparison with the General Population: A Historical Cohort Study.

BACKGROUND: The purposes of the present study were to identify the determinants of health status 3 to 6 years after open reduction and internal fixation (ORIF) for the treatment of closed ankle fracture and to compare the health status of patients who had undergone this procedure with that in the general population after adjusting for sociodemographic variables, body mass index (BMI), and smoking status. METHODS: The present study was a historical cohort study combined with a postal survey. In total, 1,149 patients who underwent ORIF for the treatment of closed ankle fractures at 2 hospitals were eligible for chart review; 959 with low-energy fractures were eligible for a postal survey, and 471 (49%) responded to the Short Form Health Survey-36 (SF-36) health status questionnaire and provided data on BMI. Determinants of the physical functioning (PF), physical component summary (PCS), and mental component summary (MCS) scores of the SF-36 were analyzed by means of multivariable linear regression analysis. The health status of patients with an ankle fracture (n = 471) was compared with that in a sample of the general population (n = 5,396) by means of multivariable regression. RESULTS: Age, American Society of Anesthesiologists (ASA) class III, and complications following surgery were associated with PF and PCS scores, and a BMI of ≥30 kg/m2 and current smoking status was associated with PF and MCS scores. However, the PF, PCS, and MCS scores of patients with ankle fractures did not differ from those of the general population, with unstandardized regression coefficients of 0.25 (95% confidence interval [CI], -1.67 to 2.16; p = 0.80), 0.67 (95% CI, -0.35 to 1.70; p = 0.199), and -0.57 (95% CI, -1.63 to 0.49; p = 0.29), respectively. CONCLUSIONS: Age, ASA class III, and complications following surgery were associated with PF and PCS scores at 3 to 6 years after surgery for the treatment of closed ankle fractures. However, the health status of patients with ankle fractures did not differ from that in the general population after adjusting for differences in demographic variables, BMI, and smoking status. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Correlations between strength and quantitative computed tomography measurement of callus mineralization in experimental tibial fractures.

BACKGROUND: the evaluation of fracture healing in the clinic has not changed significantly during the past few decades, despite the development of modern tissue-imaging tools. Recent publications have reported significant and interesting associations between biomechanical properties and quantitative computed tomography data of fractures and grafts. We therefore studied the correlations between the strength and segmented quantitative computed tomography data of tibial diaphyseal fractures. METHODS: forty male rats received a tibial-shaft osteotomy that was initially stabilized with either intramedullary nailing or external fixation. Evaluation at 30 and 60 days post-osteotomy included X-ray, quantitative computed tomography and bending testing. Quantitative computed tomography data were segmented by voxel density into soft callus (171-539 mg/cm(3)), hard callus (540-1199 mg/cm(3)) and cortical bone (≥ 1200mg/cm(3)), and volumetric bone mineral density was calculated. FINDINGS: all fractures demonstrated pronounced formation of soft and hard callus tissues at 30 days post-osteotomy, and at 60 days the cortical bone volume was significantly increased with callus resorption. Bending strength correlated significantly and positively with fracture-site cortical bone volume and volumetric bone mineral density in the intramedullary nailed group in the early phase of healing. INTERPRETATION: quantitative computed tomography was used to quantify characteristic secondary healing. The observed correlations indicate that biomechanically important mineralization can be measured by quantitative computed tomography in the early phase of healing in flexibly fixed fractures.

The influence of compression on the healing of experimental tibial fractures.

PURPOSE: Experimental studies of the effects of various mechanical conditions and stimuli on bone healing have disclosed an improvement potential in bone fracture mineralization and biomechanical properties. We therefore evaluated the effect of a clinically practicable application of a mechanical compressive interfragmentary stimulus on the healing of experimental tibial diaphyseal fractures. METHODS: Sixty Male rats received a standardized tibial shaft osteotomy stabilized with a unilateral external fixator with a zero interfragmentary distance, and then randomly assigned to the compression (N=20), control (N=20) or distraction (N=20) group. From days 4 to day 14, the external fixator was either tightened (compression group) or loosened (distraction group) once daily to gradually induce a total axial displacement of the external fixator pin clamps of 1.25 mm. Evaluation at 30 and 60 days post-osteotomy included radiography, dual-energy X-ray absorptiometry (DXA), quantitative CT and mechanical testing. RESULTS: All fractures healed radiographically with sparse callus. At 60 days, the compression and control groups exhibited significantly less amount of mineralized callus in terms of DXA measured callus area and bone mineral content (BMC) compared to the distraction group. These groups also demonstrated a smaller volume of low-mineralized bone tissue (callus) and a larger volume of highly mineralized bone tissue (cortical bone) measured by QCT than in the distraction group. Both mechanical strength and stiffness was significantly higher in the compression and control groups than in the distraction group at 60 days. DISCUSSION: Compression did not enhance fracture healing in terms of mineralization, bending strength, or stiffness at the time of union, compared with the control condition. The compression and control groups exhibited improved healing in terms of mechanical strength and stiffness and a more mature callus mineralization compared with the distraction group.

The Effect of timing of conversion from external fixation to secondary intramedullary nailing in experimental tibial fractures.

Diaphyseal tibial fractures with initial temporary external fixation (EF) are usually converted to intramedullary nailing (IMN) within 2 weeks, and no consensus on the optimal conversion time point exists. Current clinical practice is mainly based on estimation of the risk of postoperative infection. This is the first investigation of the effect of timing of such conversion on fracture healing. Forty male rats received a standardized tibial shaft osteotomy and EF. The animals were then randomly assigned to conversion to IMN at either 7 (group A, N = 10), 14 (group B, N = 10), or 30 (group C, N = 10) days after initial fixation. Group D (N = 10) served as a control group without conversion. Evaluation at 60 days included X-ray, DXA, and mechanical testing. Group A had significantly increased bone mineral content and callus area compared to the control group. Groups B and C showed significantly inferior mechanical bending strength and rigidity compared to both group A and the control group (D). The timing of the conversion procedure has a significant effect on fracture healing. Early conversion procedure did not improve healing compared to control, but was advantageous compared to late conversion (at 2 or 4 weeks) with higher mineralization and superior biomechanical properties.

Short-term treatment with COX-2 inhibitors does not impair fracture healing.

BACKGROUND: The effects of cyclooxygenase (COX) inhibition on fracture healing are insufficiently documented, and the aim of this study was to evaluate the effects of nonspecific and specific COX-2 inhibition in the early phase of fracture healing. METHODS: Thirty rats were randomized in three groups. A diaphyseal fracture was performed and stabilized by intramedullary nailing. In group A parecoxib in a dose of 1 mg/kg body weight/day was given prior to surgery and daily for seven days; in group B diclofenac 2 mg/kg body weight/day was given; and in group C the same amount of saline was given. Blood samples were harvested at 7 and 30 days postoperatively and analyzed for active medications. At 30 days the rats were sacrificed, and the fractures were examined for bone mineralization and tested mechanically. RESULTS: The fractures healed by the production of callus. Plasma concentrations at seven days of medication revealed therapeutic levels of parecoxib, valdecoxib, and diclofenac. There were no significant differences in bone mineralization or mechanical characteristics between the three groups at 30 days postfracture. CONCLUSION: This study indicates that nonspecific or specific COX-2 inhibitors in therapeutic doses during seven days after fracture do not significantly influence bone healing.

Conversion of external fixation to definitive intramedullary nailing in experimental tibial fractures.

BACKGROUND AND PURPOSE: Initial treatment with external fixation of tibial fractures is indicated in severely injuried multitrauma patients. A conversion procedure to secondary nailing is often performed later to enhance fracture repair. The aim of the study was to compare definitive treatment of experimental tibial fractures with external fixation to an early conversion to secondary intramedullary nailing with large and small diameter nails. METHODS: Thirty male rats were subject to a standardized tibial shaft osteotomy initially stabilized with external fixation. On day 7, they were assigned to either the control group (group A, N = 10) or conversion to secondary nailing with a small (group B, N = 10) or large diameter nails (group C, N = 10). Evaluation at 60 days included radiography, dual energy radiographic absorptiometry (DXA), and mechanical bending testing. RESULTS: All fractures healed radiographically with bridging of the fracture line and more or less visible periosteal callus formation. Group B demonstrated significantly increased mineralization and callus formation measured as DXA parameters, bone mineral content (BMC), and callus area (CA) compared to both the other two groups. This group also tended to have mechanically stronger bones with higher fracture energy compared to both the other two groups, but no significant difference in mechanical prioperties between the groups was found in our study. INTERPRETATION: In conclusion, we found that conversion from external fixation of leg fractures in rats to intramedullary nailing did not improve bone healing significantly supporting external fixation as definitive fracture management.

External fixation compared to intramedullary nailing of tibial fractures in the rat.

BACKGROUND AND PURPOSE: It is not known whether there is a difference in bone healing after external fixation and after intramedullary nailing. We therefore compared fracture healing in rats after these two procedures. METHODS: 40 male rats were subjected to a standardized tibial shaft osteotomy and were randomly assigned to 2 treatment groups: external fixation or intramedullary nailing. Evaluation of half of each treatment group at 30 days and the remaining half at 60 days included radiography, dual energy radiographic absorbtiometry, and mechanical testing. RESULTS: Radiographically, both treatment groups showed sign of fracture healing with gradual bridging of the fracture line, while with intramedullary nailing the visible collar of callus was increased peripherally, indicative of periosteal healing. At 30 days, densitometric and mechanical properties were similar in the 2 groups. At 60 days, however, the intramedullary nailed bones had more strength, greater callus area, and higher bone mineral content in the callus segment compared to externally fixated fractures. INTERPRETATION: Tibial shaft fractures in the rat treated with external fixation and intramedullary nailing show a similar healing pattern in the early phase of fracture healing, while at the time of healing intramedullary nailing provides improved densitometric properties and superior mechanical properties compared to external fixation. Clinical findings indicate that intramedullary nailing in human tibial fractures may be more advantageous for bone healing than external fixation, in a similar way.

Documentation of hip prostheses used in Norway: a critical review of the literature from 1996--2000.

We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of prostheses used for primary total hip replacement (THR) in Norway. The study is based on two Health Technology Assessment reports from the UK (Faulkner et al. 1998, Fitzpatrick et al. 1998), reviewing the literature from 1980 to 1995. Using a similar search strategy, we have evaluated the literature from 1996 through 2000. We included 129 scientific and medical publications which were assessed according to a specific appraisal protocol. The majority (72%) were observational studies, whereas only 9% were randomized studies. We could not retrieve any peer-reviewed documentation for one third of the implants. The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90% implant survival after about 10 years. Survival of the Charnley prosthesis declines by about 10% during each of the two following decades. Except for the Charnley and Lubinus IP, no other prosthesis on the market in Norway has given long-term results (> 15 years). 5 other cemented implants have given comparable results at about 10 years of follow-up. Some uncemented stems have shown promising medium-term outcome, but no combination of uncemented cup and stem fulfilled the benchmark criterion of > or = 90% implant survival at 10 years, which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR. New or undocumented implants should be introduced through a four-step model including preclinical testing, small series evaluated by radiosterometry, randomized clinical trial involving comparison with a well-documented prosthesis, and finally, surveillance of clinical use through registers.