Cost-Effective Analysis of Dual-Energy Computed Tomography for the Diagnosis of Occult Hip Fractures Among Older Adults.

OBJECTIVE: Early and accurate diagnosis of hip fractures minimizes morbidity and mortality. Although current guidelines favor magnetic resonance imaging (MRI) for the diagnosis of occult hip fractures, a new technology called dual-energy computed tomography (DECT) seems an effective alternative. This article investigates a potentially cost-effective strategy for the diagnosis of occult hip fractures in older adults in Singapore. METHODS: A decision tree model was developed to compare costs from a payer's perspective and outcomes in terms of quality-adjusted life-years (QALYs) of different imaging strategies for diagnosing occult hip fracture, comparing MRI with DECT supplementing single-energy computed tomography (SECT) and SECT alone. Model inputs were obtained from local sources where available. Sensitivity analyses are performed to test the robustness of the results. RESULTS: The MRI strategy was dominated by the DECT strategy, whereas DECT supplementing SECT provided 0.30 more QALYs at an incremental cost of SGD106.41 with an incremental cost-effectiveness ratio of SGD352.52 per QALY relative to SECT alone. DECT seemed a cost-effective strategy at a willingness-to-pay threshold of SGD50 000 per QALY. CONCLUSION: DECT supplementing SECT is a cost-effective imaging strategy to diagnose occult hip fractures among older adults in Singapore and should be included in clinical pathways to expedite timely treatment and considered for reimbursement schemes.

Diagnostic value of cone beam computed tomography (CBCT) in occult scaphoid and wrist fractures.

OBJECTIVE: Evaluate the diagnostic value of cone beam computed tomography (CBCT) for scaphoid and wrist fractures that are missed on standard radiographs. MATERIALS AND METHODS: Between September 2014 and October 2015, we prospectively enrolled 49 patients with a clinically suspected scaphoid fracture following an acute injury but had normal radiographs. Each patients underwent radiographs, CBCT and (magnetic resonance imaging) MRI within 7days of the initial injury event. Both exam were evaluated independently by two radiologists. RESULTS: For scaphoid cortical fractures CBCT sensitivity is 100% (95% CI: 75%-100%), specificity 97% (95% CI: 83%-100%). CBCT diagnosed all 24 corticals wrist fractures, corresponding to a sensitivity of 100% (95% CI: 83%-100%), specificity of 95% (95% CI: 75%-100%). Kappa agreement rate between the two radiologists was K=0.95 (95% CI: 0.85-1) for scaphoid fractures and K=0.87 (95% CI: 0.73-1) for wrist fractures. CONCLUSIONS: CBCT is superior to radiographs for diagnosing occult cortical fractures. Because of its low radiation dose, we believe that CBCT can be used in current practice as a replacement or supplement to radiographs to detect these fractures and optimize the cost-effectiveness ratio by limiting the number of needless immobilizations.

Diagnostic value of ultrasonography in elbow trauma in children: Prospective study of 34 cases.

INTRODUCTION: Among the various elbow injuries in children that initially have normal radiographs, a certain number of occult fractures are only diagnosed correctly after the fact, during a follow-up visit. PURPOSE: This study evaluated the diagnostic contribution of ultrasonography in the treatment of acute elbow injuries in children and the strategic and economic impact of using this tool alongside radiography. MATERIALS AND METHODS: During this prospective study performed between January 1 and April 1 2014, elbow ultrasonography was performed within 6 days in all children under 15 years of age with a suspected occult fracture. The ultrasonography exam looked for lipohemarthrosis, the posterior fat pad sign and cortical disruption. If no fracture was visible on ultrasonography, a removable splint was given to the patient to relieve pain, and no radiological or clinical follow-up was scheduled. The patients were contacted again at least 15 days later to determine whether an undetected fracture was present. Lastly, we evaluated the cost of treatment with and without ultrasonography in the cases where no fracture was diagnosed. RESULTS: In 13 cases, ultrasonography revealed lipohemarthrosis and a fat pat sign, with cortical disruption also present in 11 of these cases. In two cases, the diagnosis was made based solely on the presence of lipohemarthrosis and a fat pat sign. There were seven lateral condyle fractures, two medial epicondyle fractures and two supracondylar fractures. Among the 21 patients with normal ultrasonography, no fracture was diagnosed later on. In patients without a fracture, using ultrasonography resulted in a cost savings of €29.10 per patient versus not using it. CONCLUSION: In our study, ultrasonography is a sensitive examination for the diagnosis of occult elbow fractures in children. When the radiography and ultrasonography are both normal, the possibility of fracture can be rule out definitively, which reduces the need for immobilization, follow-up and treatment costs. The findings of this preliminary study should be validated with a larger prospective study.

Early MRI versus conventional management in the detection of occult scaphoid fractures: what does it really cost? A rural pilot study.

INTRODUCTION: To compare the cost-effectiveness and patient impact between acute magnetic resonance imaging (MRI) management and conventional management in the diagnosis of occult scaphoid fractures in a rural setting. METHODS: Consecutive patients presenting to a rural emergency department (ED) with a suspected scaphoid fracture were randomly assigned to either conventional management (6) or acute MRI management (10) (3 patients were excluded from the study analysis). All healthcare costs were compared between the two management groups and potential impacts on the patients' pain, mobility and lifestyle were also measured. RESULTS: There were no significant differences between the two groups at baseline. There was one (10%) scaphoid fracture in the MRI group and none in the conventional group (P = 0.42). A larger proportion of other fractures were diagnosed in the MRI group (20% (2) vs. 16.7% (1), P = 0.87), as well as less clinic attendances (1 (0-2.25) vs. 4 (2.25-5)) and diagnostic services (1 (1-1.25) vs. 2 (1-3)). Median management costs were $485.05 (AUD) (MRI) and $486.90 (AUD) (conventional). The MRI group had better pain and satisfaction scores as well as less time of immobilisation, treatment and time off work. CONCLUSION: MRI dramatically reduces the amount of unnecessary immobilisation, time of treatment and healthcare usage in a rural setting. The two protocols are suggested to be equivalent financially. When potential societal costs, the amount of unnecessary immobilisation, low prevalence of true fractures and patient satisfaction are considered, acute MRI should be the management technique of choice. Further studies are still required to assess the best method for managing bone bruise within the scaphoid.

Diagnosis of occult radial head and neck fracture in adults.

The purpose of this study was to compare imaging modalities in the diagnosis of occult radial head and neck fractures and to assess the diagnostic value of ultrasound in diagnosing occult fractures of the radial head and neck. The study included 193 patients (101 male, 92 female) who were referred by trauma surgeons from January 2011 to July 2014 and presented with history of acute elbow trauma. The mean age of the patients was 37 years (range 15-82 years); 95 right and 98 left elbows were included in the study. Clinical examinations and standard radiograms were conducted. The anteroposterior radiographic view revealed no visible signs of fracture. The lateral radiographic view showed displacement of the anterior and posterior fat pads (fat pad sign) due to joint effusion, which is an indirect sign of fracture. In all 193 cases, ultrasound examination showed intraarticular effusion. In 176 cases (91%), there was effusion in both the olecranon bursa and the elbow joint. In 10 patients (5%), there was effusion only inside the elbow joint and in seven cases (4%) there was effusion only in the olecranon bursa. Cortical discontinuity (a direct sign of fracture) was clearly visualised in 157 cases (82%), in the radial neck in 108 cases and in the radial head in 49 cases. Ultrasound findings of fracture were questionable in 36 cases (18%). Step-off deformities, tiny avulsed bone fragments, double-line appearance of cortical margins, and diffuse irregularity of the bone surfaces were identified as auxiliary ultrasound findings (indirect signs of fracture). Standard radiograms were repeated after 7-10 days. In 184 cases (95%), there was a clearly visible fracture: a fracture of the radial neck in 111 cases (58%) and a fracture of non-displaced radial head in 73 cases (37%). In nine cases (5%), radial fracture was not confirmed on radiogram and MRI was performed in these patients. In conclusion, ultrasound imaging proved to be an effective method for diagnosing occult fractures of the radial head or neck when initial radiograms showed only intraarticular effusion. Ultrasound imaging is a cost-effective, easy-to-use and radiation-free method. For these reasons we recommend it for early detection of occult fracture in the emergency room.

Detection of occult vertebral fractures by quantitative assessment of bone marrow attenuation values at MDCT.

OBJECTIVES: To determine a cut-off value of Hounsfield attenuation units (HU) at multidetector computed tomography (MDCT) for valid and reliable detection of bone marrow oedema (BME) related to occult vertebral fractures. METHODS: 36 patients underwent both MDCT and Magnetic Resonance Imaging (MRI) for evaluation of vertebral fractures of the thoracolumbar spine and were included in this retrospective study. Two readers independently assessed HU values at MDCT in a total of 196 vertebrae. Reliability was assessed by intraclass correlation coefficient and Bland-Altman analysis. For each patient we determined the vertebra with the lowest HU value and calculated the HU-difference to each other vertebral body. HU-differences were subjected to receiver operating characteristic (ROC) curve analysis to determine the diagnostic accuracy for detection of BME as determined by MRI, which served as the reference standard. Results of HU-measurements were compared with standard visual evaluation of MDCT. RESULTS: HU measurements demonstrated a high interrater reliability (ICC=0.984). ROC curve analysis (AUC=0.978) exhibited an ideal cut-off value of 29.6 HU for detection of BME associated with vertebral fractures with an accuracy of 97.4% as compared to 93.4% accuracy of visual evaluation. Particularly, HU-measurements increased the sensitivity for detection of vertebral fractures from 78.0% to 92.7% due to the detection of 7 of 9 occult fractures that were missed by visual evaluation alone. CONCLUSIONS: Assessing bone marrow density by HU measurements using the cut-off of 29.6 HU is a valid and reliable tool for detection of BME related to occult vertebral fractures in MDCT. The introduced technique may allow more accurate treatment decisions and may make further diagnostic work-up with MRI unnecessary.

Reliability and validity of a mobile phone for radiographic assessment of ankle injuries: a randomized inter- and intraobserver agreement study.

BACKGROUND: Current mobile phone technology may allow orthopaedic surgeons to make clinical decisions using radiographs viewed on a small mobile device screen. The purpose of this study was to examine the reliability and validity of interpreting ankle fracture images viewed on a mobile device and a computer monitor, with a hypothesis that the agreement in clinical decision making between the mobile device and computer monitor would be high. METHODS: A randomized interobserver and intraobserver reliability study was conducted in which 16 mortise and lateral ankle images representing a severity spectrum of malleolar ankle, plafond, and extra-articular tibial fractures were shown to volunteer orthopaedic surgeons on both an Apple fourth-generation iPod Touch and a 23-inch liquid crystal display (LCD) computer monitor. Participants answered a multiple-choice questionnaire for each image regarding diagnosis, severity, need for higher level imaging, need for acute inpatient versus outpatient management, and plan of treatment. Inter- and intraobserver reliability was assessed by kappa (κ), multirater kappa statistics, and intraclass correlation coefficient (ICC). RESULTS: Ninety-three orthopaedic surgeon volunteers completed the study. Excellent intraobserver agreement (κ ≥ 0.8) was found for all variables measured, including diagnosis (median κ = 0.84), need for computed tomography scan (κ = 0.86), need for reduction (κ = 0.82), treatment setting (κ = 0.82), and treatment type (κ = 0.87). Interobserver agreement was consistent between the mobile device and computer screen. Interobserver agreement for the severity assessment had a slightly higher ICC for the mobile device compared with the computer monitor (ICC = 0.83 vs 0.79). Sixty-seven percent (62/93) said at the completion of the study they were "completely" or "very" comfortable using a mobile device as a primary viewing device for new emergency room, inpatient, or transfer request consults. CONCLUSIONS: Strong reliability for radiographic assessment of ankle injuries existed between a 23-inch computer monitor and a handheld mobile device. Further study is warranted to validate the technology to apply to other anatomic locations and imaging modalities. LEVEL OF EVIDENCE: Level II, diagnostic study.

Quantitative assessment of bone marrow attenuation values at MDCT: an objective tool for the detection of bone bruise related to occult sacral insufficiency fractures.

OBJECTIVES: To prove the feasibility of using Hounsfield attenuation values at MDCT to detect bone bruises related to sacral insufficiency fractures. METHODS: Twenty-two patients with acute sacrum trauma and no fracture findings at MDCT were included in our prospective study. Two observers independently reviewed CTs regarding visual signs of bone bruises in 132 defined regions of the sacral alae. Interobserver agreement was tested by κ statistics. Subsequently, HU values were obtained in the same regions, and attenuation differences between the two sides were calculated. Validity and reliability were assessed by intraclass correlation coefficient and Bland-Altman analysis. HU differences were subjected to ROC curve analysis to determine sensitivity, specificity, PPV and NPV. MRI served as standard reference. RESULTS: MRI revealed 19 regions with bone bruises and associated sacral insufficiency fractures. HU measurements demonstrated good validity and reliability (r = 0.989). ROC curve analysis exhibited an ideal cutoff value of 35.7 HU density difference between affected and non-affected regions. Visual evaluation revealed moderate agreement (κ = 0.48); diagnostic accuracy was inferior to objective evaluation. CONCLUSIONS: Assessment of differences in bone marrow density by HU measurements is an objective and reliable tool for detection of bone bruises associated with occult sacral insufficiency fractures. KEY POINTS : • Bone bruising is associated with occult sacral insufficiency fractures. • Assessment of differences in bone marrow CT attenuation appears valid and reliable. • Comparative HU measurements of bone marrow allow detection of bone bruises. • Comparative HU measurements have high specificity and negative predictive values. • Comparative HU measurements may make further diagnostic workup with MRI unnecessary.

Management of occult fractures in the skeletally immature patient: cost analysis of implementing a limited trauma magnetic resonance imaging protocol.

STUDY OBJECTIVE: Fractures in children may not be visible in the result of initial radiography, and undertreatment and overtreatment of such fractures routinely occur. The purpose of this study was to evaluate the potential cost of implementing limited magnetic resonance imaging (MRI) at initial encounter, when radiographs are unrevealing. METHODS: This was a retrospective review of 204 emergency department pediatric patients presenting between January 1, 2005 and February 28, 2006 with appendicular trauma, with initially negative radiographic result and follow-up. Emergency department treatment categorization of (1) no treatment, (2) ACE wrap, (3) brace, (4) splint, or (5) casting was evaluated. Final determination of presence or absence of fracture was based on follow-up. Patients with fractures were considered undertreated when they received categories 1 to 3 care; patients without fractures were considered overtreated when they received categories 4 and 5 care. The percentage of patients undertreated or overtreated and direct and total costs were determined and analyzed in conjunction with the cost of a limited MRI at initial encounter. Total costs include direct and indirect costs (lost wages for each day off work for the parent). Cost estimates assume patients determined to be without fractures at follow-up will not return for follow-up clinical care or obtain additional imaging after MRI at initial encounter. RESULTS: Twenty-eight (13.7%) of the 204 patients had fractures at follow-up. Fifty one percent of patients without fractures were overtreated; 29% with fractures were undertreated. Mean direct cost for all patients and cost estimation with limited MRI protocol were $843.81 and $891.79, respectively (P = 0.365). However, mean total cost for all patients and cost estimation with limited MRI protocol was $1059.49 and $929.10, respectively (P = 0.02). CONCLUSIONS: Based on clinical grounds and initially negative radiographic results, slightly more than half of patients without fractures can be overtreated, and nearly one third of patients with fractures can be undertreated. Instituting a protocol that includes limited trauma MRI lowers the total cost of care without increasing direct cost, and appropriate care may be instituted at the outset.

An economic analysis of management strategies for closed and open grade I tibial shaft fractures.

BACKGROUND: Closed and open grade I (low-energy) tibial shaft fractures are a common and costly event, and the optimal management for such injuries remains uncertain. METHODS: We explored costs associated with treatment of low-energy tibial fractures with either casting, casting with therapeutic ultrasound, or intramedullary nailing (with and without reaming) by use of a decision tree. RESULTS: From a governmental perspective, the mean associated costs were USD 3,400 for operative management by reamed intramedullary nailing, USD 5,000 for operative management by non-reamed intramedullary nailing, USD 5,000 for casting, and USD 5,300 for casting with therapeutic ultrasound. With respect to the financial burden to society, the mean associated costs were USD 12,500 for reamed intramedullary nailing, USD 13,300 for casting with therapeutic ultrasound, USD 15,600 for operative management by non-reamed intramedullary nailing, and USD 17,300 for casting alone. INTERPRETATION: Our analysis suggests that, from an economic standpoint, reamed intramedullary nailing is the treatment of choice for closed and open grade I tibial shaft fractures. Considering financial burden to society, there is preliminary evidence that treatment of low-energy tibial fractures with therapeutic ultrasound and casting may also be an economically sound intervention.

Quantitative and qualitative assessment of closed fracture healing using computed tomography and conventional radiography.

RATIONALE AND OBJECTIVES: Development of new agents to induce fracture healing requires more sensitive methods to detect early changes in fracture repair. The aims of this study were to determine quantitative and qualitative features of fracture healing using volumetric computed tomography (CT) and to compare them with conventional radiography during the weeks following uncomplicated fractures of the appendicular skeleton. MATERIALS AND METHODS: 39 otherwise healthy men and women with acute, closed fractures of the distal radius, tibial and/or fibular malleoli, or tibial shaft, were enrolled and underwent CT and X-ray imaging at 1, 2, 4, 8, 12, and 16 (tibial shaft only) weeks post fracture. Qualitative assessment included fracture line/margins, fracture gap, external callus appearance, callus-to-cortex ratio, bridging, and radiologic union. Quantitative assessment of CT density changes (Hounsfield units [HU]) in the fracture gap was performed in a subset of 8 fracture patients using MEDx multimodality image analysis software (Sterling,VA). The analysis was performed by drawing free form regions of interest (ROI) covering the fracture gap on baseline (week 1) images and by automated registration of the follow-up images to the baseline co-ordinate system. RESULTS: The mean time to achieve radiologic union on CT was slightly shorter than on X-rays for radial and tibial shaft fractures (7.3 vs. 8.0 weeks, P = .1). Blurring of the fracture margins and reactive sclerosis were the earliest signs of healing in both modalities. External callus formation was evident in 11 cases and was detected earlier with CT technique. Overall, CT images allowed for more complete and detailed visualization of healing compared with conventional X-rays, which were limited by cast and fixation hardware superimposition, especially in subjects with malleolar and distal radial fractures. Quantitative evaluation showed good intraobserver and interobserver reproducibility and a statistically significant correlation to qualitative changes. CONCLUSION: Our methods of fracture healing assessment are reliable tools that are able to detect early changes in normal bone healing and may serve as useful additions to subjective image analysis in monitoring fracture healing in clinical trials. CT shows some advantages over conventional X-rays in evaluation of early fracture healing.

[Occult fractures of the carpal navicular. Detection by quantitative radioscintigraphy. Social and medico-legal repercussions]. / Les fractures occultes du scaphoïde carpien Détection par la radioscintigraphie quantitative. Incidences sociales et médico-légales.

Fractures of the scaphoid of the wrist are not easily diagnosed and when they are eventually recognized due to late complications, the prognosis is much poorer than it would have been at injury. Medical negligence and poorly-performed or interpreted x-rays are frequently cited as reasons for non-diagnosis. Often these fractures are trabecular, so-called occult, and they cannot be seen on a conventional exam, even if well-performed. Tomography and tomodensitometry have yielded poor results. Quantitative radioscintigraphy (QRS), the exam we are proposing, is a modification of scintigraphy, which is a very sensitive exam (100%) but has little specificity. The first step in QRS is to quantify the fixation of the tracer on the injured side and compare it to that of the uninjured side. If the injured side fixation is double that of the uninjured side, a fracture (often scaphoid) is present. MRI is our reference. In the second step in QRS, a computer-assisted fusion is made of the scintigraphic image and the x-ray (quantitative scintigraphy has the same diagnostic value as MRI). The center of the fracture is localized, thus yielding a specificity of nearly 100% for this exam. Out of a prospective series of 154 patients who had a conventional examination: 41% were diagnosed to have a scaphoid fracture using QSR, therefore a number higher than supposed. Rare carpal fractures were also detected. The cost of this exam is low. The exam climinates non-diagnosed fractures which can lead to non-union and arthrosis. Due to the frequency of carpal trauma, this exam should have a significant effect on the individual, on social security costs and litigations.

Isolated closed diaphyseal fractures of the femur in children: comparison of effectiveness and cost of several treatment methods.

The effectiveness of several treatment modalities for isolated closed femur fractures in children ages 4 through 16 years is compared based on outcome (clinical results, morbidity, and parents' satisfaction) and cost. Between 1986 and 1993, 30 patients were treated. Treatment methods included immediate hip spica cast application, distal femoral skeletal traction pin to align the fracture followed by early hip spica cast incorporating the pin (6th day), in-hospital traction, primary external fixation, and primary intramedullary nailing. Average follow up was 4.1 years. Overall results were excellent with minimal morbidity for all treatment methods. Early application of hip spica cast with or without incorporation of the distal femoral traction pin required the fewest hospital days, the shortest time to union, and had the lowest overall cost. Complications, mainly malunion and femoral length discrepancy, however, were greater. Skeletal traction resulted in the longest hospital stay and was equal in cost to external fixation and intramedullary nailing. Primary external fixation appears most applicable in patients who are unlikely to tolerate early casting and who are at increased risk of avascular necrosis with femoral nailing. Patients treated with an intramedullary nail had the fewest complications. Age, size, and gender of patient, location and type of fracture, as well as social circumstances are all significant factors in choosing the optimal method of treatment.

[Bone callus: possible assessment with color Doppler ultrasonography. Normal bone healing process]. / Il callo osseo: possibilità di valutazione mediante eco color Doppler. Processo osteoriparativo normale.

Conventional US demonstrates bone callus dimensions and structure, which permits to monitor the bone healing process. January, 1993, through May, 1995, we examined 108 patients with simple fractures of humerus, femur and tibia; all the fractures had been treated with an external or intramedullary metallic fixator. All the patients were submitted to conventional and color-Doppler US of the fracture focus on all possible scanning planes. We considered morphological parameters (the presence/absence of vessels, their number and shape) and functional parameters (the resistive index and the presence of a telesystolic notch). Color-Doppler US and the spectral analysis allowed us to add functional data, on bone callus and newly formed bone vascularization, to morphological studies. In the patients with positive fracture evolution, the caliber of afferent vessels progressively increased, their number decreased and branches appeared. The RI progressively increased, up to similar values to those of nutrient vessels (.36 to .90). Within the second month of fracture, a telesystolic notch appears: this indicates a muscular tunic in the vessel wall, meaning a mature, and no longer a newly formed, vessel. The normal evolution of bone healing may be interrupted by several mechanical and biohumoral factors which reportedly act in a similar way by reducing the number of vessels and increasing peripheral resistance in residual vessels because of fibrosclerotic involution of bone healing. Color-Doppler US permits noninvasive, repeatable and nearly real-time monitoring of bone fracture healing, which suggests this technique could be used: -to assess the results of treatment changes (e.g., loading, external fixator adjustments); -to study the definitive callus; -for the medicolegal assessment of delayed bone healing and of pseudoarthrosis; -for real-time treatment planning, according to color-Doppler findings, and to monitor treatment results.

Diagnostic value of ultrasonography and conventional radiography for the assessment of sternal fractures.

This study compares the sonographic and conventional radiographic examination of sternal fractures. Forty-five patients with a suspected sternal fracture were examined radiographically and sonographically. Sixteen had a sternal fracture which could be identified sonographically. In 15 of the 16 cases an equivalent diagnosis could be made radiologically. In one case no definite statement could be made radiologically but the sonographic finding together with the clinical aspect of the patient proved the diagnosis of a fracture. In four sternal fractures displaced by more than one anteroposterior thickness, the fracture itself was shown by sonography whereas the extent of the injury could not be displayed. Ultrasonic investigation of the sternum is a useful way to demonstrate fractures that provides a similar sensitivity to conventional radiography. In contrast sonography is not suited for portraying the grade of displacement. In case of doubt after radiological examination the ultrasonic examination serves as a valuable tool but conventional plain radiography remains the standard means of documenting a sternal fracture.

Tibial shaft fractures: assessment of fracture healing with computed tomography.

OBJECTIVE: To assess the capability of CT in assessing stability of tibial shaft fractures with planimetry. MATERIALS AND METHODS: Eighteen patients with fracture of the tibial shaft were treated by external fixator. All patients underwent CT 1, 6, 12, and 18 weeks postoperatively to assess the fracture healing. The callus formation and compacta were determined with planimetry. Fractometry, a noninvasive method to measure stability, was used as the gold standard to determine the stability of the fracture. RESULTS: The patients were divided into three groups according to different periods of time for removal of external fixation. Twelve patients with stable fractures showed a steady increase of callus, which was 50% higher after 12 weeks. Three patients with delayed fracture healing demonstrated an increase of callus of > 50% after 18 weeks. Three patients with unstable fractures obtained only callus formation of < 20% after 15-18 weeks. The external fixator was removed and endomedullary nails were used for stabilization. CONCLUSION: The CT data allow quantification of callus and compacta formation and are able to determine the stability of tibial shaft fractures.

Adolescent femoral shaft fractures: rigid versus flexible nails.

Twenty-one skeletally immature patients between 11 and 16 years of age were treated operatively for a unilateral femoral shaft fracture. Eleven patients underwent fixation with flexible nails and 10 with rigid nails. The patients were studied retrospectively to determine the similarity of the groups. Each method of fixation was then compared to determine the technical ease and final outcome. Both methods gave excellent final radiographic alignment with minimal complications. Flexible nailing required much less operative time and less fluoroscopy time. Estimated cost of using Ender nails is much less than using Russell-Taylor interlocking nails.

Prediction of fracture in patients with acute musculoskeletal ankle trauma.

X-rays taken for ankle trauma contribute significantly to the cost of health care in this country. In an attempt to find clinical correlates of ankle fracture 36 detailed historical and physical examination variables were collected from 587 consecutive patients with ankle trauma, and ankle x-rays were taken of all patients. The association of each variable with the final diagnosis of fracture, rupture, or sprain was tested; 21 variables were significant predictors of fracture (vs. sprain and rupture) and 15 were not significantly associated with final diagnosis. The variables were used in a linear discriminant analysis to develop a rule which would predict the final diagnosis. If only those patients predicted by the rule to have fractures had been x-rayed, all patients with fracture would have been identified but more than a fourth of all ankle trauma patients would have been spared x-rays. This compares favorably with a recently published rule that did not assess sensitivity. A simulated prospective evaluation suggests that these results are stable, but that up to 10% of the fractures could be missed on the first visit. Although current practice is not well documented, it appears that use of this rule could yield substantial cost savings.