Cross-Calibrated Dual-Energy X-Ray Absorptiometry Scanners Demonstrate Systematic Bias in Pediatric and Young Adult Females

Consistency of dual-energy X-ray absorptiometry (DXA) scan results is critical for data integrity. For pediatric subjects, the extent to which cross-calibration of DXA scanners alleviates model-to-model scanner differences is unclear. In the current study, DXA bone outcomes were compared for same-day measurements performed using different scanners, cross-calibrated to alleviate discrepancies (Hologic; Discovery A [DISCO] and QDR 4500W [QDR]). Interscanner differences were evaluated in approximately 130 females aged 8-24 yr. Scans were performed in a single session on both QDR and DISCO scanners to compare projected area, bone mineral content, and areal bone mineral density (BMD) outputs for the whole body (total, subhead, head, arm, and leg), forearm (1/3 and ultradistal radius), lumbar spine (vertebra L3 and L1-L4), and proximal femur (femoral neck). Paired t tests evaluated interscanner differences; concordance correlation coefficients (CCCs) evaluated interscanner correlations. Root mean square error coefficients of variation were compared to same-day duplicate DISCO scan root mean square error coefficients of variation for approximately 30 adult females. Deming regression equations were generated for conversion of QDR to DISCO results and vice versa. Interscanner correlations were very high (95% confidence interval for CCC > 0.90), for all outcomes except for femoral neck area and subhead area (95% confidence interval for CCC = 0.83-0.94, 0.57-073). However, QDR values were systematically lower than Discovery values (p < 0.05), except for head area, head bone mineral content, head BMD, ultradistal BMD (QDR > Discovery, p ≤ 0.05) and L1-L4 area, L3 area, and femoral neck BMD (no differences). Most Bland-Altman and Deming regression plots indicated good interscanner agreement, with little systematic variation based on bone or body size. In pediatric and young adult females, subtle but systematic differences were noted between scans obtained on DISCO and QDR scanners, despite cross-calibration, such that most outcomes are systematically higher for DISCO than for QDR. The use of conversion equations is warranted.

A rig for acquisition of standardized trabecular bone radiographs

To assess osteoarthritic changes in knee joints a radiography rig for acquisition of standardized radiographs of trabecular bone has been developed. The rig contains a steel frame on castors, a turntable, a cassette holder frame, calibration Plexiglas sheets, body supports and points. It is used to lock the patient in a standardized position. A film cassette holder frame was also developed to reduce scattering of X-rays, and consequently the amount of noise in the radiographs. Calibration Plexiglas sheets were mounted on ball bearing slides to obtain radiographs without a calibration pattern (suitable for the analysis of trabecular bone texture) and radiographs containing a calibration pattern (suitable for the measurement of leg alignment).

A method for estimating gestational age of fetal remains based on long bone lengths

The estimation of gestational age (GA) in fetal human remains is important in forensic settings, particularly to assess fetal viability, in addition to often being the only biological profile parameter that can be assessed with some accuracy for non-adults. The length of long bone diaphysis is one of the most frequently used methods for fetal age estimation. The main objective of this study was to present a simple and objective method for estimating GA based on the measurements of the diaphysis of the femur, tibia, fibula, humerus, ulna, and radius. Conventional least squares regression equations (classical and inverse calibration approaches) and quick reference tables were generated. A supplementary objective was to compare the performance of the new formulae against previously published models. The sample comprised 257 fetuses (136 females and 121 males) with known GA (between 12 and 40 weeks) and was selected based on clinical and pathological information. All measurements were performed on radiographic images acquired in anonymous clinical autopsy records from spontaneous and therapeutic abortions in two Portuguese hospitals. The proposed technique is straightforward and reproducible. The models for the GA estimation are exceedingly accurate and unbiased. Comparisons between inverse and classical calibration show that both perform exceptionally well, with high accuracy and low bias. Also, the newly developed equations generally outperform earlier methods of GA estimation in forensic contexts. Quick reference tables for each long bone are now available. The obtained models for the estimation of gestational age are of great applicability in forensic contexts.

Isometric Scaling in Developing Long Bones Is Achieved by an Optimal Epiphyseal Growth Balance

One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Although organ scaling is fundamental for development and function, little is known about the mechanisms that regulate it. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation and, therefore, their position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations. Here, we document the process of longitudinal scaling in developing mouse long bones and uncover the mechanism that regulates it. To that end, we performed a computational analysis of hundreds of three-dimensional micro-CT images, using a newly developed method for recovering the morphogenetic sequence of developing bones. Strikingly, analysis revealed that the relative position of all superstructures along the bone is highly preserved during more than a 5-fold increase in length, indicating isometric scaling. It has been suggested that during development, bone superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. Surprisingly, our results showed that most superstructures did not drift at all. Instead, we identified a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between proximal and distal growth rates, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process. Our study reveals a general mechanism for the scaling of developing bones. More broadly, these findings suggest an evolutionary mechanism that facilitates variability in bone morphology by controlling the activity of individual epiphyseal plates.

A novel computational approach for studying bone morphogenesis reveals that the longitudinal proportions of developing long bones are accurately maintained throughout elongation by the balance between proximal and distal growth rates.

One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation. Therefore, superstructure position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations.

Here, by analyzing a massive database of micro-CT images of developing mouse long bones, we show that all superstructures maintain their relative positions throughout development. It has been suggested that during development, superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. However, our analysis reveals that most superstructures did not drift at all, implying the involvement of another mechanism. Indeed, we identify a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between the growth rates from its two ends, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process.

Automatic segmentation of leg bones by using active contours

In this paper, we present a new active contours model to segment human leg bones in computed tomography images that is based on a variable-weighted combination of local and global intensity. This model can split an object surrounded by both weak and strong boundaries, and also distinguish very adjacent objects with those boundaries. The ability of this model is required for segmentation in medical images, e.g., human leg bones, which are usually composed of highly inhomogeneous objects and where the distances among organs are very close. We developed an evolution equation of a level set function whose zero level set represents a contour. An initial contour is automatically obtained by applying a histogram based multiphase segmentation method. We experimented with computed tomography images from three patients, and demonstrate the efficiency of the proposed method in experimental results.

Erdheim-Chester disease with rare radiological features in a 14-year old girl with pre-B Acute Lymphocytic Leukemia and Diabetes Mellitus

We report a case of a 14 year-old girl with Diabetes Mellitus who was in remission with pre-B cell Acute Lymphoblastic Leukemia and subsequently diagnosed with Erdheim-Chester disease. Erdheim-Chester disease is a non-Langerhans cell histiocytosis and is very rare in children. In addition, the radiological features of the lesions are atypical and have not been reported in children. There is no known association between the three conditions and this is the first reported case in the literature. A literature review of Erdheim-Chester disease will be performed.

Do long leg supine CT scanograms correlate with weight-bearing full-length radiographs to measure lower limb coronal alignment?

INTRODUCTION

The gold standard for measuring knee alignment is the lower limb mechanical axis (MA) using weight-bearing lower limb full-length x-ray (FLX). However, CT scanograms (CTS) are becoming increasingly popular in view of lower radiation exposure, speed of data acquisition and supine positioning. We compared the correlation and degree of agreement of knee joint coronal alignment using these two imaging modalities.

METHOD

From our series of complex primary and revision knee arthroplasty patients, we selected those with both FLX and CTS recorded onto digital PACS. The coronal alignments were assessed in 24 knees and the valgus/varus angles relative to the MA were measured. Results were analysed statistically using the paired samples t-test, Pearson's correlation coefficient, intra-class correlation coefficient, Cohen's kappa and Passing and Bablok regression to assess potential equality of methods.

RESULTS

The mean MA was 180.5° (165°-200°) for the CTS and 181° (164°-202°) for the FLX. The CTS MA angle data between the assessors were highly correlated (r=0.971, p <0.001) as were FLX MA angle measurements (r=0.988, p <0.001). 41.7% of the CTS and 37.5% of the FLX were in varus alignment, while 50% of the CTS and 43.8% of the FLX were in valgus alignment. Malalignment >5° was revealed by 18.8% of the CTS and 35.4% of the FLX.

CONCLUSION

Overall, good agreement was observed in MA angle data between the two imaging modalities, but reproducibility may be problematic. In the malaligned limb, weight-bearing FLX still remains a vital imaging modality. CTS should be used with caution in view of the under-detection of malalignment.

Treatment of long bone nonunions: factors affecting healing

PURPOSE

Nonunions of the upper and lower extremity have been associated with pain and functional deficits. Recent studies have demonstrated that healing of these nonunions is associated with pain relief and both subjective and objective functional improvement. The purpose of this study was to determine which patient and surgical factors correlated with successful healing of a nonunion following surgical intervention.

METHODS

Between September 2004 and February 2008, all patients with a "long bone nonunion" presenting to our academic trauma service were enrolled in a prospective data base. Baseline functional, demographic and pain status was obtained. Follow-up was obtained at 3, 6, and 12 months following surgical intervention, with longer follow-up as possible. One hundred and thirty-four patients with a variety of fracture nonunions were operated on by four different fellowship trained trauma surgeons with experience ranging from 2 to 15 years and variable nonunion surgery loads. Patients were stratified into one of three groups: 1. Patients who healed following one surgical intervention, 2. those who healed following multiple surgical intervention, and 3. those who failed to heal (remain ununited or underwent amputation). Healing was determined radiographically and clinically. Complications were recorded. Logistic regression analysis was performed to assess the cor-relation between specific baseline and surgical characteristics and healing.

RESULTS

A minimum of 1 year follow-up was available for all 134 patients. One hundred and one patients (76%) with a mean age of 50 years healed at a mean of 6 months (range, 3 to 16) after one surgery. Twenty-two patients (16%) with a mean age of 47 years, who required more than one intervention, healed their nonunions at a mean of 11 months (range, 4 to 23). Eleven patients (8%) with a mean age of 50 years failed to heal at an average of 12 months follow-up. Complication rates were 11%, 68%, and 100% respectively for those who healed following one procedure, multiple procedures, and those who never healed. Higher surgeon volume (greater than 10 cases per year) was associated with 85% increased healing rates (OR = 0.15, 0.05-0.47 CI). The presence of a postoperative complication was associated with a 9 times lower likelihood of successful union as well (OR = 9.0, 2.6-31.7 CI). Patient age, sex, BMI, initial injury mechanism, tobacco use, and initial injury characteristics did not correlate with failure to heal.

CONCLUSION

Our data is similar to other studies assessing outcomes following other complex reconstructive procedures. It appears that more experienced (higher volume) reconstructive surgeons and the development of fewer postoperative complications is associated with greater success following repair of a long bone nonunion. Infection at any point during treatment is associated with failure to achieve successful union.

Differences in leg bone geometry in young, old and very old women

Bone geometry is an important measure of bone strength and is known to be affected by weight-bearing and adult ageing. Engagement in weight-bearing activity decreases with age, thus in this study we compared bone geometry changes between weight-bearing (tibia) and non-weight-bearing (fibula) leg bones in three different age groups of women. Magnetic resonance images of the right leg were acquired in 9 young (20-27 years), 7 old (61-69 years) and 7 very old (71-80 years) women. Total and cortical bone volumes and medullary cavity volumes (mm(3)) were calculated at proximal and distal sites for both bones. Tibial cortical bone volume was significantly less at the proximal site in old (17%) and very old (24%) groups versus young subjects. Cortical bone volume in the proximal fibula was also significantly reduced in the older groups (7 and 12%), but to a substantially lesser extent than in the tibia. In contrast, distal bone geometry appeared largely to be conserved in both tibia and fibula. Proximally, medullary cavity volume was greater in the older groups in the tibia but not the fibula. Distally, the only difference found in either bone was a significantly greater fibular medullary cavity in the very old group. These findings suggest weight-bearing bones in women are more susceptible than non-weight-bearing bones to age-related changes in bone geometry likely due to decreases in weight-bearing activities. Also, weight-bearing activity appears to provide a greater osteogenic stimulus at the distal portions of the leg bones.

[Stature estimation of teenagers by limb long bones with computerized radiography]

OBJECTIVE

Relative parameters of upper limb bones, tibia and fibula were measured with computed radiography and used to establish the mathematical models for stature estimation of teenagers (from 14 to 18 years old) of Han population in Sichuan Province.

METHODS

The upper limb bones, tibia and fibula of 194 subjects were taken computerized radiography on normal position and were measured the lengths between relative landmarks. The body height of each subject was recorded. Linear regression equations for stature estimation between body height and the lengths of upper limb bones, tibia and fibula were established.

RESULTS

Forty-two single linear regression equations and 4 multiple regression equations were obtained. The coefficients of correlation(r) were 0.689-0.917 and the standard errors of estimate(SE) were between 3.075 and 5.485 cm. All of the equations were statistically tested and diagnosed with good applicability.

CONCLUSION

These equations could be used to estimate the body height of Sichuan Han population aged from 14 to 18. The lengths of the upper limb bones, tibia and fibula measured on the CR films could be useful to stature estimation of the adolescence and the forensic personal identification.

Camptomelia in a rhesus macaque (Macaca mulatta)

An 8.5-mo-old female rhesus macaque was examined for an apparent lump on the right arm, below the elbow. The macaque showed no signs of pain or discomfort. Examination revealed that the lump was actually a bend in the forearm. Radiography demonstrated that some of the long bones of the animal were bowed. Differential diagnoses included rickets, hyperparathyroidism, pseudohyperparathyroidism, and a growth dysplasia. No other similar abnormalities in animals from that cage or any other enclosure in our large colony were observed. Blood chemistries and a complete hemogram were within normal limits for a macaque of this age. Serum was submitted for a vitamin D profile that included assays for parathyroid hormone, 25-hydroxyvitamin D, and ionized calcium. Serum samples from sex- and age-matched normal controls were sent for comparison and to establish a baseline profile. The affected animal had vitamin D levels comparable to unaffected controls. Bone biopsies appeared normal for a macaque of this age. Fluorine levels in the drinking water supply were within acceptable limits. Consistent with the information available, a diagnosis of idiopathic camptomelia, or bowing of the long bones, was made. In humans, developmental camptomelia is associated with several bone dysplasias in infants and children. These conditions are thought to be caused by genetic mutations in enzymes or transcription factors that control development of the epiphyses and are almost always associated with other lethal and nonlethal developmental abnormalities.

[Prognosis of long tubular bone strength changes in surgery of chronic osteomyelitis]

Mineral bone density (MBD) in osteomyelitic focus and symmetric intact tubular bone was compared in 54 patients. Changes of MBD values were also measured after surgical treatment (bone trepanation or osteonecroectomy with bone plasty). Thus, MBD, and, therefore, bone strength, was mostly higher in pathologic focus then in the healthy bone. Operative treatment showed no negative influence on MBD.

Age, gender, and race/ethnic differences in total body and subregional bone density

SUMMARY

Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing.

INTRODUCTION

Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton.

METHODS

The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing.

RESULTS

Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm.

CONCLUSION

This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.

Postarthroplasty examination using X-ray images

Arthroplasty, the implantation of prostheses into joints, is a surgical procedure that is affecting a larger and larger number of patients over time. As a result, it is increasingly important to develop imaging techniques to noninvasively examine joints with prostheses after surgery, both statically and dynamically in 3-D. The static problem is considered here, with the aim to create a 3-D shape model of the bone as well as the prosthesis using a set of 2-D X-rays from various viewpoints. The most important challenge to be addressed is the lack of texture, the most common feature to recover shape from multiple views. In order to overcome this limitation, we reformulate the problem using a novel multiview segmentation approach where an active contours 3-D surface evolution with level-set implementation is used to recover the shape of bones and prostheses in postoperative joints. The recovered shape may then be used to track 3-D motions in dynamic X-ray sequences to obtain kinematic information.

Bone mineral density in children with neurofibromatosis 1

AIM

Our aim was to detect the status of bone mineral density (BMD) in children with NF1, and thus to help the management of the skeletal complications of NF1.

METHODS

Dual-energy X-ray absorptiometry (DEXA) was performed in lumbar spine, total body, proximal femur and forearm in 31 children (3.1-18 years) with NF1. Correlations among the BMD values of four regions were calculated statistically. Z-scores of lumbar- and total body-BMD were also evaluated in 24 patients at and older than 5 years.

RESULTS

Eleven children had skeletal findings, including mild scoliosis in 5 patients. No case with total body-Z score <-2 was detected. Lumbar-Z score was lower than -2 in 3 out of 24 cases. Patients with any skeletal involvement of NF1 were likely to have a lumbar-BMD lower than -2 in comparison with patients with no skeletal finding (odds ratio 4; 95% CI 0.01-4.62). Proximal femur-BMD values (g/cm(2)), yet forearm-BMDs, were correlated with both lumbar- and total body-BMD, regardless of skeletal involvements of NF1.

CONCLUSIONS

Our findings suggest that lumbar- or proximal femur-DEXA, rather than forearm- or total body-DEXA, could reveal significantly decreased BMD in children with NF1, especially in those with skeletal involvement of NF1.

Imaging of pseudoneoplastic masses associated with allografts

OBJECTIVE

The objective of this study is to describe the imaging features of non-neoplastic masses suspected of being tumor recurrences adjacent to allografts. The allografts were utilized for the treatment of various musculoskeletal tumors.

MATERIALS AND METHODS

We reviewed the medical records and imaging studies of 56 patients who were suspected of having recurrent tumors following surgical resection and allograft replacement treatment for a variety of musculoskeletal neoplasms. The imaging modalities included radiographs, CT, and MRI.

RESULTS

There were 47 cases of recurrent tumors. All tumor recurrences were in the soft tissues of the surgical bed (41 patients), or in the native bone adjacent to the host/allograft junction (6 patients). None of the recurrences originated in the allografts. Nine patients suspected of having recurrences were discovered to have non-neoplastic masses. Five of these were very closely related to the allograft, wrapping around parts of the allograft, and the other 4 were in the surgical bed, 2 of which were abscesses and two were seromas.

CONCLUSION

Most masses arising in the vicinity of allografts implanted following resection of musculoskeletal tumors represent recurrent neoplasms. A minority are reactive processes or abscesses or fluid collections. These "pseudoneoplasms," specifically those closely related to the allografts, have specific imaging characteristics that help distinguish them from recurrent tumors.

Full-limb and knee radiography assessments of varus-valgus alignment and their relationship to osteoarthritis disease features by magnetic resonance imaging

OBJECTIVE

To examine the correlation between hip-knee-ankle and femur-tibia radiograph angles, calculate the offset of the femur-tibia angle with respect to the hip-knee-ankle angle, calculate the sensitivity and specificity and area under the receiver operating characteristic (ROC) curve of the femur-tibia angle, and examine the relationship of malalignment by each approach with osteoarthritis (OA) tissue pathology in the mechanically stressed compartment using magnetic resonance imaging (MRI).

METHODS

Individuals with knee OA underwent full-limb and knee radiographs and knee MRI. Linear regression was used to determine if the 2 angles differed systematically and to identify the cutoff. Alignment means for MRI grades were compared using Dunnett's t-test.

RESULTS

In the 146 participants (109 women, mean age 70 years, body mass index 30.6 kg/m(2)), femur-tibia and hip-knee-ankle angles correlated (r = 0.86; 95% confidence interval [95% CI] 0.81, 0.90). On average, the femur-tibia angle was 3.4 degrees more valgus (3.0 degrees in women and 4.7 degrees in men); after correction, its sensitivity and specificity (to predict the hip-knee-ankle angle) were 0.84 and 0.84 for identifying varus and 0.98 and 0.73 for valgus, respectively. The area under the ROC curve (95% CI) was 0.91 (0.86, 0.96) for varus and 0.94 (0.89, 0.99) for valgus. Varus severity worsened comparably with each alignment measure as medial lesion score on MRI worsened. Laterally, as lesion score worsened, comparably worse valgus was seen with either assessment approach.

CONCLUSION

In knee OA, the knee radiograph femur-tibia and full-limb radiograph hip-knee-ankle angles were correlated. The femur-tibia angle, corrected for mean offset, was sensitive, specific, and had excellent discriminative ability for identifying varus and valgus alignment evidenced by area under the ROC curve. The relationship between alignment and specific OA MRI features was comparable with the 2 approaches. Use of the femur-tibia angle, corrected for offset, should be considered in research and clinical settings.

Preoperative and postoperative limb alignment after Oxford unicompartmental knee arthroplasty

From a series of 64 sequential Oxford (Biomet Orthopedics, Inc, Warsaw, phase 3 implants, two study groups were selected: 23 knees with unilateral surgery and a normal opposite side, and 21 knees with bilateral simultaneous surgery. Standing 3-foot radiographs were taken pre- and postoperatively to assess the femorotibial angle and the location of the mechanical axis of the limb in relation to the knee. Results in the unilateral group showed an average postoperative femorotibial angle of 4.50 was compared to a 3.40 angle for the normal side, (not significantly different; P=.09). Results for the bilateral group were an average postoperative femorotibial angle of 3.40 for the right and 3.50 for the left, (not significantly different; P=.7). The location of the mechanical axis was similar between the knees in both groups. The study concludes that the Oxford soft-tissue balancing technique restores alignment, which is on average similar to the opposite side, and therefore presumably normal for that knee. Restoration of normal alignment should not put excess stress onto the lateral compartment.

Prediction of Stature Based on Radiographic Measurements of Cadaver Long Bones: A Study of the Croatian Population

We tested a new approach to the stature prediction that could be used in the identification process of human skeletal remains of unknown identity. The stature of 19 female and 21 male adult cadavers was measured within 24 h after death and considered to be equal to the living stature. The antero-posterior radiographs of all limbs were taken, and the maximum length of the six long bones was measured from radiographs. There was a significant difference in the stature and maximum length of long bones between female and male cadavers (p<0.001 for all). The correlation between the stature and long bone length was the best for the humerus in females (r=0.792) and the tibia in males (r=0.891). Regression equations specific to the Croatian population were computed separately for each long bone in males and females and proven to be reliable in predicting the living stature of the individual.

Terminal hemimelia of the lower extremity: absent lateral ray and a normal fibula

Congenital lateral ray deficiency is considered to be a manifestation of fibular hemimelia. However, we have noted patients with absent lateral ray but stable knee and ankle joints, and named this condition terminal hemimelia of the lower extremity. This study was undertaken to further define this group of patients and to compare these patients with fibular hemimelia patients. Four boys and one girl of mean age six years two months were in the terminal hemimelic group and four boys and three girls of mean age eight years seven months in the fibular hemimelic group at the final evaluation. Clinical features commonly observed in the fibular hemimelia such as knee valgus, knee instability, tibial bowing, ball and socket ankle, ankle instability, tarsal coalition, leg length inequality were compared between both groups. Terminal hemimelia of the lower extremity was the same as fibular hemimelia in clinical features below the ankle joint. However, terminal hemimela was found to be milder than fibular hemimelia in terms of limb shortening. The clinical features above the ankle joint were different between both groups. Knees and ankles were stable, and gait disturbance were rarely noticed in patients with terminal hemimelia of the lower extremity.

Exchange nailing of ununited fractures

Exchange nailing is most appropriate for a nonunion without substantial bone loss. There is no clear consensus regarding the use of exchange nailing in the presence of active, purulent infection. The exchange nail should be at least 1 mm larger in diameter than the nail being removed, and it has been recommended that it be up to 4 mm larger when the nail being removed was greatly undersized. Canal reaming should progress until osseous tissue is observed in the reaming flutes. Exchange nailing is an excellent choice for aseptic nonunions of noncomminuted diaphyseal femoral fractures, with union rates reported to range from 72% to 100%. On the basis of the available literature, exchange nailing cannot be recommended for distal femoral nonunions at this time. Exchange nailing is an excellent choice for aseptic nonunions of noncomminuted diaphyseal tibial fractures, with union rates reported to range from 76% to 96%. On the basis of the available literature, exchange nailing is generally not indicated for humeral nonunions.

Klinische Erfahrungen mit Bone Morphogenetic Protein 7 (BMP 7) bei Pseudarthrosen langer Röhrenknochen

BACKGROUND

Nonunions of long bone fractures are considerable therapeutic and economic problems with increasing tendency. Basic surgical options are autogenous cancellous bone grafting, rod dynamization, reamed nailing, plate fixation with compression, and bone transport techniques. If these methods fail to work, alternative treatment options are needed.

MATERIAL AND METHODS

Since May 2001 treatment with recombinant human (rh) bone morphogenic protein 7 [BMP-7 or osteogenic protein 1 (OP-1)] in combination with a type one collagen carrier has gained interest. BMP 7 induces the formation of new bone by differentiation of stem cells, thereby initiating the reaction cascade of osteogenesis. Nonunions over 9 months and unsuccessful bone grafting delineate the indication.

RESULTS

We report our experience with 21 patients and nonunion of long bone fractures. Between July 2002 and June 2004, 23 units of BMP 7 were implanted. The implantation sites were 7 femora, 12 tibias, 2 humeri, and 2 forearms. In ten cases BMP 7 was combined with a new osteosynthesis and bone grafting and in five patients with bone grafting alone. In contrast in eight patients BMP 7 was applied as a single procedure without any bone grafting or any change of the osteosynthesis.

CONCLUSION

There were no peri- or postoperative complications. Follow-up was obtained for a minimum of 6 months. Of 23 implantations, 22 were successful with bony healing revealed by clinical and radiological evaluation. In one patient no bony consolidation of the nonunion has been seen so far. In summary, based on our results we propose BMP 7 as an additional innovative therapy of long bone nonunions.

Computer-assisted optimization of correction osteotomies on lower extremities

Automated methods are presented for the planning of correction osteotomies and osteosynthesis on lower extremities. Intraoperative calibrated X-ray images and kinematic measurements using optical tracking systems are the basis for the identification of the individual anatomy of the patient. The correction input of the surgeon, together with optimization algorithms, allows the calculation of the position and orientation of the osteotomies and the repositioning of the bone fragments. A navigation module supports the surgeon during the execution of osteotomies and repositioning, as well as osteosynthesis. So far, the approach has been evaluated in laboratory trials and ex vivo tests.

Is there an alternative to the full-leg radiograph for determining knee joint alignment in osteoarthritis?

OBJECTIVE

To assess the concurrent validity of alternative measures of frontal plane knee alignment, namely the radiographic anatomic axis and 5 clinical measures, in medial compartment knee osteoarthritis (OA) as compared with the mechanical axis on radiograph.

METHODS

Forty individuals (mean +/- SD age 64.7 +/- 9.4 years) with symptomatic medial knee OA participated. Knee alignment was measured according to the following methods: lower-limb mechanical axis on radiograph, lower-limb anatomic axis on radiograph, visual observation, distance between medial knee joint lines or medial malleoli using a caliper, distance between a plumb line and medial knee joint line or malleolus using a caliper, tibial alignment using a gravity inclinometer, and lower-limb alignment using a goniometer. Data were analyzed using Pearson's correlation coefficient or Spearman's rho correlation coefficient and simple linear regression.

RESULTS

The anatomic axis best correlated with the mechanical axis (r = 0.88), followed closely by the inclinometer method (r = 0.80). Other clinical measures of alignment that were significantly associated with the mechanical axis were the caliper method, the plumb-line method, and visual observation (r = 0.76, 0.71, and -0.52, respectively). However, the goniometer method failed to correlate.

CONCLUSION

The anatomic axis on radiograph and the inclinometer method appear to be valid alternatives to the mechanical axis on full-leg radiograph for determining frontal plane knee alignment in medial knee OA. These alternative methods of measuring knee alignment may increase the assessment of this parameter by clinicians and researchers alike, given that malalignment is an important indicator of disease progression and treatment outcome.

Improvement in bone homeostasis following autologous chondrocyte implantation of the knee

This retrospective review and clinical follow-up demonstrates the effectiveness of autologous chondrocyte implantation of the knee. From September 1995 to June 2001, 24 patients with average follow-up of 26.5 months were evaluated. The mean Lysholm score improved from 43.58 before surgery to 71.42 at most recent follow-up, the modified Cincinnati knee score for overall clinician evaluation improved from 2.96 to 6.92, and the mean modified Cincinnati knee score for overall patient evaluation improved from 3.21 to 6.13 at P <.05. Seventy-nine percent of patients responded that they would have the same knee surgery again and 83% rated the results of their knee surgery as good to excellent. Limited radionuclide bone scans with single photon emission computed tomography were completed in 11 of the patients to assess the physiology and homeostasis of subchondral bone adjacent to treated articular cartilage defects. A trend was identified suggesting improvement in subchondral bone scores at a mean of 29.6-months follow-up compared to preoperative bone scan assessment. There also was a trend towards greatest improvement correlating with the patients with the best clinical scores. The results of this study suggest that autologous chondrocyte implantation of the knee can be successful in improving pain and function in patients with articular cartilage defects.

MMP13 mutation causes spondyloepimetaphyseal dysplasia, Missouri type (SEMD(MO)

MMPs, which degrade components of the ECM, have roles in embryonic development, tissue repair, cancer, arthritis, and cardiovascular disease. We show that a missense mutation of MMP13 causes the Missouri type of human spondyloepimetaphyseal dysplasia (SEMD(MO)), an autosomal dominant disorder characterized by defective growth and modeling of vertebrae and long bones. Genome-wide linkage analysis mapped SEMD(MO) to a 17-cM region on chromosome 11q14.3-23.2 that contains a cluster of 9 MMP genes. Among these, MMP13 represented the best candidate for SEMD(MO), since it preferentially degrades collagen type II, abnormalities of which cause skeletal dysplasias that include Strudwick type SEMD. DNA sequence analysis revealed a missense mutation, F56S, that substituted an evolutionarily conserved phenylalanine residue for a serine in the proregion domain of MMP13. We predicted, by modeling MMP13 structure, that this F56S mutation would result in a hydrophobic cavity with misfolding, autoactivation, and degradation of mutant protein intracellularly. Expression of wild-type and mutant MMP13s in human embryonic kidney cells confirmed abnormal intracellular autoactivation and autodegradation of F56S MMP13 such that only enzymatically inactive, small fragments were secreted. Thus, the F56S mutation results in deficiency of MMP13, which leads to the human skeletal developmental anomaly of SEMD(MO).

Radiographic correlation in orthopedic pathology

Radiographic correlation is an essential adjunct for the accurate diagnosis of orthopedic lesions, yet it is a skill neglected by pathologists. The purpose of this review is to demonstrate why performing this correlation is an essential part of the diagnostic process and not merely an interesting adjunct to the surgical pathology of orthopedic lesions. The relationships between x-rays and tissues are explored with an emphasis on bone and soft tissue composition and structure. In addition, the rudiments of complementary imaging studies and how to incorporate their data into diagnoses are examined.

Spondylometaphyseal dysplasia with cone-rod dystrophy

The co-occurrence of ophthalmologic abnormality and intrinsic skeletal dysplasia is uncommon. We describe eight instances of a unique form of spondylometaphyseal dysplasia (SMD) associated with cone-rod dystrophy (although documentation is insufficient to be certain of that diagnosis in some). This is a new, syndromic form of SMD for which there is evidence for autosomal recessive transmission. Recognition of the specific bony features described here should precipitate comprehensive ophthalmologic assessment, since vision impairment becomes significantly disabling with age.

Marked phenotypic variability in progressive diaphyseal dysplasia (Camurati-Engelmann disease): report of a four-generation pedigree, identification of a mutation in TGFB1, and review

Progressive diaphyseal dysplasia (PDD) (Camurati-Engelmann disease) is an autosomal dominant craniotubular dysplasia characterized by hyperostosis and sclerosis of the diaphyses of the long bones and the skull. Mutations in transforming growth factor beta-1 (TGFB1) were recently found in patients with PDD. We report on a four-generation pedigree with seven individuals affected by PDD, linkage and mutational analysis results, and review the literature. This pedigree demonstrates the autosomal dominant inheritance pattern, remarkable variation in expressivity, and reduced penetrance. The most severely affected individual had progression of mild skull hyperostosis to severe skull thickening and cranial nerve compression over 30 years. His carrier father remained asymptomatic into his ninth decade and had no radiographic hyperostosis or sclerosis of the bones. Symptomatic relatives presented with lower limb pain and weakness. They were initially diagnosed with a variety of other conditions. Two of the symptomatic individuals were treated successfully with prednisone. We genotyped 7 markers from chromosome region 19q13.1-13.3 in 15 relatives and confirmed linkage to this region in this family. We screened the TGFB1 gene for mutations and identified a missense mutation resulting in an R218H substitution in the affected individuals, the asymptomatic obligate carrier, and another unaffected relative. We genotyped the family for seven known TGFB1 polymorphisms and a novel TAAA tetranucleotide repeat in intron 1. These polymorphisms did not appear to account for the variability in disease severity in this family. Our review illustrates how the disorder can significantly compromise health. Cranial involvement, which occurs in 61% of patients, can be severe, entrapping cranial nerves or causing increased intracranial pressure. Therapy with corticosteroids should be attempted in all symptomatic patients.

Fundamental subchondral bone changes in spontaneous knee osteoarthritis

Osteoarthritis has an unknown aetiology, and tissue samples from early stage human osteoarthritis tissue cannot be reliably obtained. Therefore understanding the development of OA relies on using animal models: such as the spontaneous changes seen in the Dunkin-Hartley guinea pig strain, which are biochemically, histologically and radiologically similar to human OA. We investigated the role of bone change in early OA development using the non-OA developing Bristol strain-2 as control from 3 to 36 weeks by standard microfocal X-ray imaging and histological techniques. The patella, tibia and femur epiphyseal region and immediate subchondral area were analysed for bone density at all ages. We found that both radiological and histological osteoarthritis scores increased progressively for the Dunkin-Hartley, but not for the BS2 demonstrating its value as a control. The Dunkin-Hartley had a higher bone density and greater subchondral bone thickness from 24 weeks of age. We conclude that prior to any gross osteoarthritis pathology the Dunkin-Hartley are undergoing subchondral bone remodelling, thus demonstrating the fundamental role of early bone remodelling in the development of osteoarthritis.

Percutaneous Ultrasound-guided Biopsy in the Definitive Diagnosis of Osteosarcoma

Thirty-three patients with 35 bone lesions suspicious for osteosarcoma underwent image-guided biopsy. Of those 35 biopsies, 12 were performed with use of fluoroscopy or computed tomography (CT) guidance to target the osseous abnormality. Diagnostic magnetic resonance imaging revealed a soft tissue component in 23 cases; in these cases, biopsies were performed with use of ultrasonography (US) to target the soft tissue component of the tumor. Of the 35 tumors in which biopsy was performed, 33 (94%) were definitively diagnosed as osteosarcoma by image-guided biopsy. All 23 US-guided biopsies resulted in definitive diagnosis. Two of the 12 fluoroscopy- or CT-guided biopsies (17%) were inconclusive.

Inferior vena cava filters prevent pulmonary emboli in patients with metastatic pathologic fractures of the lower extremity

The records of 47 consecutive patients with metastatic pathologic fractures of the lower extremity were analyzed with respect to thromboembolic complications. All patients were unable to receive pharmacologic deep venous thrombosis prophylaxis, and were stratified into two groups, based on use of an inferior vena cava filter. Group I (n = 24) consisted of patients who had an inferior vena cava filter plus mechanical deep venous thrombosis prophylaxis (compression stockings and sequential compression boots); Group II (n = 23) consisted of a group of patients receiving only mechanical deep venous thrombosis prophylaxis. All patients had routine lower extremity venous duplex imaging preoperatively, postoperatively, and before hospital discharge. At final followup, patients were examined for deep venous thrombosis and reviewed for thromboembolic events. At a mean followup of 11.5 months, Group I had two detectable deep venous thromboses and no pulmonary emboli; Group II had one detectable deep venous thrombosis and five pulmonary embolisms. In Group II, 40% (two of five) of pulmonary embolisms were fatal, yielding an 8.7% (two of 23) group mortality rate. Overall, the entire group had an approximately 17% deep venous thrombosis rate. Only 6.4% (three of 47) of deep venous thromboses were detectable by standard duplex imaging. The majority of deep venous thromboses (five of eight, 62.5%) were nondetectable by duplex imaging. Overall, a 4.3% (two of 47) death rate was attributable to pulmonary embolism. In contrast, an 8.6% (four of 47) mortality rate occurred in Group II alone. All pulmonary embolisms occurred in patients who did not receive an inferior vena cava filter. The majority of venous thromboses (62.5%) were not detectable on duplex scanning, therefore were thought to arise from the pelvic venous system. Complications related to inferior vena cava filter insertion were minimal. For patients with metastatic pathologic fractures of the lower extremities who are unable to receive pharmacologic deep venous thrombosis prophylaxis, the use of inferior vena cava filters, in conjunction with standard mechanical deep venous thrombosis prophylaxis, is a procedure that has a low risk and is useful adjunct to prevent fatal pulmonary embolisms.

Amorphous Silicon, Flat-Panel, X-ray Detector

RATIONALE AND OBJECTIVES

To evaluate composed long-leg images acquired with a large-area, flat-panel x-ray detector with regard to angle and distance measurements.

METHODS

Radiographs of a long-leg phantom were acquired at 13 different angle settings with a 43-cm x 43-cm digital x-ray detector based on cesium iodide (CsI) and amorphous silicon (a-Si) technology. Three overlapping single images of the phantom were reconstructed at a workstation using a generalized correlation method. Four blinded observers were instructed to determine the angle of the axis of the long-legs as well as the length of "femur" and "tibia" on soft-copy displays. For that, the angle and distance measurement software integrated in the workstation was used. The images were analyzed with and without prior manual fine tuning of the primary composition result according to a mapped scale. Standard of reference was angle and distance determination at the phantom.

RESULTS

On average, the difference between the observers' angle measurements and the standard of reference was 0.4 degrees for both images with and without prior manual correction. Regarding distance measurements, the average discrepancies to the standard were 0.2 cm (femur) and 0.1 cm (tibia) when analyzing images that had undergone manual fine tuning and 0.5 cm and 0.7 cm, respectively, for images without manual correction.

CONCLUSIONS

The evaluated image fusion algorithm in conjunction with a 43-cm x 43-cm flat-panel detector is feasible regarding angle and distance measurements on long-leg images. In the case of inaccurate primary composition, results can be corrected easily by manual fine tuning.

Mulibrey nanism: clinical features and diagnostic criteria

Mulibrey nanism (MUL) is an autosomal recessive disease caused by mutations in the TRIM37 gene encoding the peroxisomal TRIM37 protein of unknown function. In this work, we analysed the clinical characteristics of 85 Finnish patients with MUL, most of whom were homozygous for the Finn major mutation of TRIM37. The patients' hospital records from birth to the time of the diagnosis at age 0.02-52 years (median 2.1 years) were retrospectively analysed. All except four of the patients (95%) had a prenatal onset growth failure without postnatal catch up growth. The mean length standard deviation score (SDS) was -3.1 and -4.0 at birth and at diagnosis, respectively. In infancy, feeding difficulties, and respiratory tract infections were the most common problems. Congestive heart failure and pericardial constriction were diagnosed during infancy in 12% and 6% of the patients, respectively. At the time of the diagnosis, characteristic craniofacial features of scaphocephaly, facial triangularity, high and broad forehead, and low nasal bridge were evident in over 90% of the patients. In addition, practically all patients were gracile and had thin extremities. Other findings included a peculiar high-pitched voice (96%), yellowish dots in ocular fundi (79%), cutaneous naevi flammei (65%), hepatomegaly (45%), and fibrous dysplasia of long bones (25%). Mild muscular hypotonicity (68%) was the only neurological abnormality. The clinical features of the Finnish patients with MUL formed a distinct entity. The most consistent findings were growth failure and characteristic craniofacial features. However, organ manifestations varied considerably in early childhood. Based on these findings, we propose new diagnostic criteria for MUL.

Digital image composition in long-leg radiography with a flat-panel detector: first clinical experiences

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the image quality of composed long-leg examinations with a large-area, flat-panel x-ray detector.

METHODS

Thirty-five consecutive patients were included in this study. All images were obtained with a kilovoltage setting identical with conventional radiographies of speed class 400; amperage values were reduced by 50% compared with standard dose. After acquisition, the images were transferred to a workstation where the whole image was reconstructed using a generalized correlation method. Images were presented to 3 observers. Examination quality was ranked on a 3-point scale: 1 = no manual adjustment necessary; 2 = composition required manual correction; 3 = no composition possible.

RESULTS

Patient rankings were 31/35 (88.6%) in category 1, 3/35 (8.6%) in category 2, and 1/35 (2.8%) in category 3 (primarily due to an application error).

CONCLUSIONS

The analysis of the first clinical examinations of long-leg radiographies with a 43 cm x 43 cm flat-panel detector demonstrates very good reliability of the digital image composition.

Approaches for ultrasonographic evaluation of long bones in the dog

The objective of this study was to identify access portals for ultrasonographic evaluation of canine long bones (humerus, radius, ulna, femur, and tibia). A 7.5 MHz linear transducer was used in five medium-sized dogs (range of 25-35 kg body weight). Good approaches could be identified for all long bones. For the proximal humerus, a cranial portal, and the distal humerus, a lateral portal is suggested. For the radius and ulna, a craniolateral approach seemed to be the best. In the hindlimb, a medial approach for the femur and a craniolateral approach for the tibia were the most effective approaches.

Two probable cases of treponemal disease of Medieval date from England

Two British Medieval skeletons are described. Paleopathological examination suggests that treponemal disease was present in each case. Radiocarbon dating indicates that one is firmly pre-Columbian, and the other of likely pre-Columbian date. The implications for our understanding of the history and geographic spread of the treponemal diseases, particularly venereal syphilis, are discussed.

Preoperative hip to ankle radiographs in total knee arthroplasty

Whether a preoperative long leg radiograph taken with the patient standing helps the surgeon reproduce a normal mechanical axis after total knee arthroplasty is unknown. The purpose of the current study was to evaluate whether a preoperative long leg radiograph helps to restore normal limb alignment after total knee arthroplasty. Ninety-four patients (124 primary total knee arthroplasties) were randomized to either receive or not receive a preoperative long leg standing radiograph. Patients with previous hip or ankle surgery, femoral or tibial fracture, deformity of 15 degrees or greater, or those who were obese (body weight index > 40 kg/m2) were excluded. All arthroplasties were done by one surgeon. The angle of distal femoral resection varied between 5 degrees and 8 degrees (mean, 6.2 degrees) among patients with long leg radiographs. In patients without long leg radiographs, the distal femur was cut at 5 degrees. Long leg radiographs were obtained postoperatively in all patients and the mechanical axis was assessed, first by whether the mechanical axis fell within the central third of the knee, and second by the distance in millimeters that the mechanical axis fell from the knee center. No significant difference in the postoperative mechanical axis was detected between the two groups. Eighty-six percent of the patients with long leg preoperative radiographs and 92% of the patients without long leg preoperative radiographs had the mechanical axis pass through the central (1/3) of the knee. Preoperative hip to ankle long leg radiographs taken with the patient standing did not significantly help to obtain a neutral mechanical axis during routine total knee arthroplasty.

Neonatal ablation of the nigrostriatal dopamine pathway does not influence limb development in rats

Hemiparkinson-hemiatrophy syndrome (HP-HA) is associated with skeletal hemiatrophy and the later development of parkinsonism. It is generally assumed that this phenotype is due to the combination of dysfunction of the basal ganglia (e.g., substantia nigra compacta and/or other related structures), causing parkinsonism, and of other areas (e.g., cerebral cortex), causing hemiatrophy. The occurrence of asymmetry of limb size in a patient with very asymmetric involvement of dopa-responsive dystonia encouraged Greene et al. (2000, Mov. Disord. 15: 537-541) to propose that lifelong deficits in nigrostriatal dopamine could account for limb asymmetry in HP-HA. The purpose of this study was to determine whether skeletal hemiatrophy could be produced in rats by unilateral, neonatal ablation of the nigrostriatal dopamine pathway. Infusion of 6-hydroxydopamine into the striatum of rat neonates resulted in loss of dopamine neurons in the ipsilateral substantia nigra, reduced striatal dopamine levels, and stimulant-induced motor asymmetry. Saline infusions neither altered the number of dopamine neurons nor produced behavioral changes. Both groups incurred discrete lesions of the ipsilateral motor cortex surrounding the infusion site and atrophy of the corresponding cerebral peduncle. Cortical, but not nigrostriatal, lesions were associated with significant atrophy of ipsilateral femora, humeri, and innominate bones, as assessed radiographically. Skeletal hemiatrophy was not observed in naive animals or in experimental animals that did not exhibit corticospinal abnormalities. The results of this study indicate that early skeletal development in rats is not affected by loss of nigrostriatal dopamine per se, but is markedly attenuated by corticospinal lesions sustained during the neonatal period.

[Use of the elastic stable intramedullary nailing technique in non-typical pediatric fractures]

PURPOSE OF THE STUDY

The "Elastic Stable Intramedullary Nailing" (E.S.I.N.) of French authors as a method of treatment of children's diaphyseal long bone fractures is well known from nineties of the last century. After we got familiar with the technique we wanted to introduce it in other indications, especially some metaphyseal long bone fractures and injuries of metacarpals, meta-tarsals and phalangeal bones in the growing skeleton.

MATERIAL

During two last years, i.e. 1999-2000, ESIN procedure in 97 children was performed in our Regional Pediatric Trauma Centre. That was 39% of all osteosyntheses and 3.05% of all children's fractures treated during this period. Children treated by ESIN procedure were divided into three groups (see in Methods), 52 being in group one, 28 in group two and 17 in group three.

METHODS

In our series of patients managed with the use of ESIN procedure according to the type of fractured bone and physical behavior of the implants three groups were formed. In the first group called "Classic ESIN Procedure" were children with diaphyseal long bone fracture (femur, tibia, humerus and forearm bones), in the second group "Non-typical ESIN Procedure" metaphyseal long bone fractures (humerus, radius, tibia) and in the third group, "ESIN-like Procedure" patients with metacarpal and phalangeal digital fractures were included. In all children the technique was very similar to original French (Nancy) description. Supraphyseal trepanation of the bone and introduction of usually two prebent elastic nails intramedullary.

RESULTS

All 97 children healed good. In four children we saw little problems. In one patient it was necessary to change the ESIN osteosynthesis of open tibia fracture to external fixation. In the other boy we saw delayed union of forearm bones and in the third a 2 centimeter overgrowth of the affected tibia was recorded. In the last boy where non-typical ESIN procedure was performed for proximal radial fracture separation the angulation of radial head, overgrowth and subluxation occurred. However, we were surprised by simplicity, short time of the procedure and good results in two new groups of patients with metaphyseal and metacarpal resp. phalangeal fractures.

DISCUSSION

Though in metaphyseal long-bone fractures (Non-typical ESIN Procedure) and metacarpal and phalangeal digital fractures (ESIN-like Procedure) the technique does not respect original physical suggestions of three point fragment fixation it works very well. Already the French authors from Nancy mention the indication of the ESIN technique for some metaphyseal fractures (supracondylar humeral and proximal radial). We do not use the method in supracondylar fractures but found it excellent in earlier problematic proximal humeral and radial fractures and especially phalangeal digital fractures. Also we were able to establish three main indication groups for this procedure.

CONCLUSIONS

The ESIN technique can be used in three groups of children's fractures. "Classic ESIN Procedure" in diaphyseal long bone fractures, "Non-typical ESIN Procedure" in metaphyseal long bone fractures and "ESIN-like Procedure" in metacarpal and phalangeal digital fractures.

The decision to salvage or amputate a severely injured limb

The decision to salvage or amputate a severely injured limb is one of the most difficult an orthopaedic surgeon may face. The inclination to undertake heroic measures to save the limb should be tempered by the realization that doing so may lead to repeated hospitalizations, extensive complications, and a poor functional outcome. Several factors must be considered, including objective elements related to the patient's injury and physical condition and subjective considerations related to the patient's psychologic, social, and economic status. We present a framework, in the context of a case study, which may be used in deciding which patients can benefit from early amputation and review five predictive indices for limb salvage.

Hereditary multiple exostoses: one center's experience and review of etiology

Hereditary multiple exostosis is a genetic disorder characterized by multiple osteochondromas that can cause pain, deformity, and potential malignant degeneration. Linkage analysis has identified a family of EXT genes which, if mutated, can lose heterozygosity and potentially cause osteochondromas. A database was established of 43 patients with hereditary multiple exostoses treated at a tertiary pediatric healthcare system. Twenty patients had a known family history of the disorder. All patients were diagnosed between birth and 13 years. Symptoms or deformity were observed in the forearms of 29 patients, the knees of 37 patients, and the ankles of 28 patients. Valgus knee deformity related to hereditary multiple exostoses, previously reported to be attributable to proximal tibial changes alone, resulted from proximal tibial or distal femoral valgus deformities in this series. Twenty-seven patients required between one and five surgeries to address their lesions. No patient had malignant degeneration of an osteochondroma; however, three patients had first-degree relatives with transformation of an osteochondroma to chondrosarcoma. This database now may be a resource for additional analysis. By correlating specific genetic mutations with clinical manifestations, it may be possible to stratify patients into subtypes of hereditary multiple exostoses and identify genetic markers associated with malignant degeneration.

Tc-99m sestamibi bone marrow scintigraphy in Gaucher disease

PURPOSE

No imaging technique has been found to be adequate to assess the severity and extent of bone involvement in patients with Gaucher disease. Marrow involvement, as determined by Tc-99m sulfur colloid, correlated well with the clinical and radiologic changes of the skeleton, but a normal pattern was found in the early stages of the disease. Subsequently, Tc-99m sestamibi (MIBI) has been suggested for direct visualization of glycolipid deposits in the bone marrow. This study was initiated as a pilot using MIBI to detect various forms of bone disease in patients with Gaucher disease of varying severity.

MATERIALS AND METHODS

Eleven patients (9 men; median age, 39.9; age range, 21 to 61 years) were evaluated. The clinical severity of disease was scored at presentation, and four patients with moderate to severe disease were treated with enzyme replacement therapy. Each patient underwent a radiographic skeletal survey, bone densitometry, and MIBI scintigraphy. The scan included static images of the lower limbs, with a whole-body scan acquired between the early and late acquisition. Tracer uptake in the bone marrow was graded and correlated with clinical and objective variables.

RESULTS

All but one patient had increased MIBI uptake in the bone marrow. No correlation was noted between MIBI uptake and severity score, radiographic changes, densitometry z score, or treatment status.

CONCLUSIONS

MIBI scanning is a sensitive technique for detecting bone marrow deposits in Gaucher disease, but it is inadequate for early identification of patients at high risk for skeletal complications or for the follow-up of patients treated with enzyme replacement.