Medial-lateral Diameter Research Articles

CT measurements of the proximal femoral medullary cavity in healthy adults: a cross-sectional study

Objective: To analyse the proximal femoral morphology on three-dimensional reconstructed imagery to explore the factors influencing the relevant parameters. Method: The cross-sectional study was conducted at Peking University Third Hospital in northern China from January 2019 to August 2020, and comprised healthy adults who underwent computed tomography scanning. Three-dimensional computed tomography reconstruction of the proximal femoral medullary cavity was performed using Mimics 22. The anatomical parameters related to total hip arthroplasty were measured to examine the relationship among gender, age and femoral length. Data was analysed using SPSS 20. Results: Of the 63 adults, meaning 126 hips, 21(33.3%) were males, meaning 42(33.3%) hips, and 42(66.6%) were females, meaning 84(66.6%) hips. The overall mean age was 51.5±23.1 years (range: 23-68 years). The inflection point of the medullary cavity curved at 5-10mm distal to the lesser trochanteric line. Most horizontal plane parameters significantly differed between men and women (p<0.05), with the mean medullary cavity being wider in men than women. There was a significant difference between the genders in the sagittal anterior-posterior diameter of the canal flare index (p<0.05). Age was negatively correlated with the coronal medial-lateral diameter and coronal lateral diameter of canal flare index. In the coronal and sagittal planes, there was a positive correlation between the metaphysis and diaphysis, and the coronal and sagittal planes were positively correlated with the orthogonal plane. Conclusions: Femoral morphology could be influenced by gender and age. Morphological changes of the proximal femoral medullary cavity were not present in a single plane, but were affected by multiple planes. When the diameter of one plane became larger, its orthogonal plane concomitantly increased. Key Words: Proximal femoral, Morphology, CT measurement, Correlation.

Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for lateral osteochondral lesions of the talus: operative technique.

To provide anatural scaffold, good quality cells, and growth factors to facilitate replacement of the complete osteochondral unit with matching talar curvature for large osteochondral lesions of the lateral talar dome. Symptomatic primary and non-primary lateral osteochondral lesions of the talus not responding to conservative treatment. The anterior-posterior or medial-lateral diameter should exceed 10 mm on computed tomography (CT) for primary lesions; for secondary lesions, there are no size limitations. Tibiotalar osteoarthritis gradeIII, malignancy, active infectious ankle joint pathology, and hemophilic or other diffuse arthropathy. Anterolateral arthrotomy is performed after which the Anterior TaloFibular Ligament (ATFL) is disinserted from the fibula. Additional exposure is achieved by placing aHintermann distractor subluxating the talus ventrally. Thereafter, the osteochondral lesion is excised in toto from the talar dome. The recipient site is micro-drilled in order to disrupt subchondral bone vessels. Thereafter, the autograft is harvested from the ipsilateral iliac crest with an oscillating saw, after which the graft is adjusted to an exactly fitting shape to match the extracted lateral osteochondral defect and the talar morphology as well as curvature. The graft is implanted with apress-fit technique after which the ATFL is re-inserted followed by potential augmentation with an InternalBrace™ (Arthrex, Naples, FL, USA). Non-weightbearing cast for 6weeks, followed by another 6weeks with awalking boot. After 12weeks, acomputed tomography (CT) scan is performed to assess consolidation of the inserted autograft. The patient is referred to aphysiotherapist.

Manual Compression of External Iliac Vein to Increase the Size of Femoral Vein for Femoral Central Venous Catheter Insertion in Small Children: Pilot Experimental Study and Randomized Trial

Highlights Abstract Aim: Pediatric femoral central venous catheter insertion is sometimes difficult due to small vein size. External iliac vein (EIV) compression may provide a tourniquet effect to the femoral vein (FV) and may facilitate catheterization. This study was conducted to determine the effect of EIV compression on FV size and femoral venous catheterization success rates. Methods: This study had 2 parts. The first part was a single-arm experimental study. The second part was a randomized controlled trial. Children weighing 2.5–15.0 kg were included. First part: All patients received the same intervention and measurements. FV anteroposterior and medial-lateral diameters were measured by ultrasound without EIV compression, after which EIV was compressed using the assistant’s finger, and FV diameters were measured. Second part: Patients were randomized into compression and control groups. The compression group received EIV compression during femoral venous catheterization. The control group did not receive the compression. Results: A total of 30 patients (15 in each group) participated. EIV compression significantly increased FV anteroposterior diameter (3.36 ± 1.01 mm with compression, 2.39 ± 0.76 mm without compression, mean difference = 0.97 mm, 95% CI = 0.73, 1.21, P < 0.001) and medial-lateral diameter (4.58 ± 1.40 mm with compression, 3.86 ± 1.32 mm without compression, mean difference = 0.72 mm, 95% CI = 0.43, 1.01, P < 0.001). Catheterization success rates were not different between groups. Conclusions: EIV compression increased FV size, but the effect on femoral venous catheterization success rates was inconclusive due to a small sample size.

Research on the correlation between the size of condyle and occlusion plane in skeletal Class II malocclusions.

This study was designed to investigate the relationship between the morphological structure of condyle and occlusal plane in skeletal Class II malocclusions by imaging measurement. This study included 65 skeletal Class II adult patients (18-35 years old) who met the criteria, and all were taken with cone beam computed tomography (CBCT) images (skeletal Class II high angle 38 cases, average angle 18 cases, and low angle nine cases). The statistical methods of mean standard deviation, Pearson correlation, and analysis of variance were used to study the correlation between the size of the condyle and occlusal plane in skeletal Class II malocclusion. The FMA and SN-OP between the groups in skeletal Class II malocclusion are considered statistically significant, p < .05 high angle group > average angle group > low angle group, whereas there are significant correlations between FMA, FH-OP, SN-OP, and the medial-lateral diameter (MLD) of the condyle, p < .05, showing a negative correlation. The anteroposterior diameter of the condyle has no significant correlation with these angles, and the high-angle group size is smaller than the other groups. In patients with skeletal Class II high angle malocclusion, the MLD and anteroposterior diameters of condyle were smaller than those of average angle and low angle groups, and negatively correlated with the FMA and SN-OP. That is the steeper occlusal plane, the smaller MLD of the condyle. It suggests whether orthodontists can promote the stability of the morphological structure of the condyle by changing the inclination of the occlusal plane during the orthodontic process.

Triangular Mechanical Structure of the Proximal Femur.

The mechanical high modulus structure of the proximal femur could guide clinical surgical treatment and instrument design of proximal femoral fractures. The purpose of this study is to analyze and verify the mechanical structure of the proximal femur. A total of 375 patients with intertrochanteric fractures were imaged using computed tomography (CT) scans. Patients were grouped according to age and sex. Cortical and medullary cavity parameters (cortical thickness [CTh], cortical mean density [CM], upper-lower diameter length [ULL], and medial-lateral diameter length [MLL]) were measured at eight planes. Six proximal femoral finite element models of different sexes and ages were constructed. To verify the measurement results, Abaqus was used to implement the force load to describe the von Mises stress distribution, and the maximum von Mises stress values of each wall of the proximal femur were compared. The CTh values of the lower and upper walls were higher than those of the anterior and posterior walls of the femoral neck (p < 0.05). The CM values of the lower and upper walls were higher than those of the anterior and posterior walls of the subcephalic and middle femoral neck (p < 0.05). The ULL value gradually increased from the subcephalic region to the bottom (p < 0.05). The CTh and CM values of the medial and lateral walls were higher than those of the anterior and posterior walls in the femoral trochanteric region (p < 0.05). The MLL value decreased gradually from the plane 20 mm above the upper edge to that 20 mm below the vertex of the femoral lesser trochanter (p < 0.05). The von Mises stress was concentrated on the upper and lower walls of the femoral neck and on the medial and lateral walls of the femoral trochanteric region. The maximum von Mises stress values of the upper and lower walls were higher than those of the anterior and posterior walls of the femoral neck. The maximum von Mises stress values of the medial and lateral walls were higher than those of the anterior and posterior walls in the femoral trochanteric region, except for the plane 20 mm above the upper edge of the femoral lesser trochanter. The bone mass of the proximal femur presented a triangular high-modulus distribution, which bore the main stress of the proximal femur. The triangular mechanical structure provides a guideline for the surgical strategy and instrument design of the proximal femur.

Estimating Tibia Length: An Anatomical Landmarks Evaluation of Bones and X-ray Radiographs

The ability to estimate the length of the bone is a major step towards estimating the stature of an individual in forensic investigation of mass fatalities where body parts are dismembered, scattered and mixed up. This is so because researchers have established that long bone length correlates with stature. Nine parameters of the tibia bone were measured using anthropometric board, anthropometric tape and digital caliper. Five of the nine parameters that could be read on anterior-posterior x-ray radiograph of the tibia measured using a transparent meter rule were used in this study. A total of 600 sample of N = 600, (300 right and 300 left bones) and (320 males: right = 160; left = 160; 280 females: right = 140; left 140 radiographs) obtained from Anatomy museums and hospitals in the six geo-political zones of Nigeria were used in this study. No significant difference (p &lt; 0.05) in the mean value was found between measurements from the bones and those from the anteroposterior x-ray radiographs. The difference in mean for all variables were seen to be significantly (p &lt; 0.05) higher for males compared to females. Results show that the tibia proximal breadth (TPB), medial-lateral diameter at mid-shaft (MLDM) and tibia distal breadth (TDB) were the best predictors of the length of tibia. Thus, in cases of mass fatalities as could happen in a plane crash or bomb blast, the estimate of the fragmented remains of the tibia, when compared with the estimate from an anti-mortem x-ray radiograph, may reveal the identity of the missing individual.

Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for large medial talar osteochondral defects : Operative technique.

ObjectiveProvision of a natural scaffold, good quality cells, and growth factors in order to facilitate the replacement of the complete osteochondral unit with matching talar curvature for large medial primary and secondary osteochondral defects of the talus.IndicationsSymptomatic primary and secondary medial osteochondral defects of the talus not responding to conservative treatment; anterior–posterior or medial–lateral diameter >10 mm on computed tomography (CT); closed distal tibial physis in young patients.ContraindicationsTibiotalar osteoarthritis grade III; multiple osteochondral defects on the medial, central, and lateral talar dome; malignancy; active infectious ankle joint pathology.Surgical techniqueA medial distal tibial osteotomy is performed, after which the osteochondral defect is excised in toto from the talar dome. The recipient site is microdrilled in order to disrupt subchondral bone vessels. Then, the autograft is harvested from the ipsilateral iliac crest with an oscillating saw, after which the graft is adjusted to an exact fitting shape to match the extracted osteochondral defect and the talar morphology as well as curvature. The graft is implanted with a press-fit technique after which the osteotomy is reduced with two 3.5 mm lag screws and the incision layers are closed. In cases of a large osteotomy, an additional third tubular buttress plate is added, or a third screw at the apex of the osteotomy.Postoperative managementNon-weight bearing cast for 6 weeks, followed by another 6 weeks with a walking boot. After 12 weeks, a CT scan is performed to assess consolidation of the osteotomy and the inserted autograft. The patient is referred to a physiotherapist.ResultsTen cases underwent the TOPIC procedure, and at 1 year follow-up all clinical scores improved. Radiological outcomes showed consolidation of all osteotomies and all inserted grafts showed consolidation. Complications included one spina iliaca anterior avulsion and one hypaesthesia of the saphenous nerve; in two patients the fixation screws of the medial malleolar osteotomy were removed.

The quantitative correlation between condylar resorption and skeletal relapse following mandibular advancement in skeletal class II malocclusion patients

ObjectiveThe purpose of this study was to analyze the quantitative correlation between condylar resorption and skeletal relapse after mandibular advancement surgery. Materials and methodsSkeletal Class II malocclusion patients who underwent bilateral sagittal split ramus osteotomy (BSSRO) were included. Three-dimensional reconstruction was based on one-week and one-year post-operative CT scans. The condylar morphological alterations were assessed by anterior-posterior, medial-lateral diameter and condylar height. The mandibular relapse was calculated by the positional changes of pogonion, menton, gonions, gnathion and mental foramens. All data were measured by MIMICS and analyzed by SPSS software; significance was set at p<0.05. Results31 patients (62 condyles) were enrolled into this study. 28 of 62 condyles showed resorption beyond 1 mm on condylar height and 15 were beyond 2 mm. Positional changes of chin, mental foramens and gonion were respectively 1.57 ± 2.36 mm, 1.31 ± 1.23 mm and 1.42 ± 1.02 mm. 21 of 31 patients experienced mandibular relapse less than 1 mm but additional 4 patients showing relapse more than 2 mm. Correlation with moderate intensity could be observed between condylar height alteration and post-operative mandibular displacement more than 1 mm (p = 0.035). ConclusionThe resorption degree of condylar height can be regarded as a useful parameter for evaluating post-operative skeletal relapse.

Bayesian modeling predicts age and sex are not required for accurate stature estimation from femoral length

Despite the recognized flaws in applying traditional stature estimation equations such as those of Trotter and Gleser (1952) [5] to a contemporary population, there are currently no available alternatives for stature estimation in Australia that address these limitations. Post mortem computed tomography (PMCT) DICOM scans of the left and right femora were acquired from 76 Australian deceased individuals aged 17–76 years for metric analysis. Femoral bicondylar length, femoral epicondylar breadth and anterior–posterior (AP) diameter, medial-lateral (ML) diameter, circumference and cortical area at the femoral midshaft were measured on three-dimensional (3D) models to build statistical models for estimating stature. In addition, Australian individuals aged 16–63 years (n=111) were measured in standing and supine positions to aid in the adjustment of supine stature of deceased individuals utilized in this study to standing stature. The results of this preliminary evaluation strongly indicate that the optimal model for estimating stature includes bicondylar femoral length and epicondylar breadth, that the effect of sex as an independent variable is very low, and there is limited practical benefit in including age in the estimation of stature. Our study indicates that the Australian population sampled represents a small yet significant shift in stature from the original Trotter and Gleser sample. Additionally, in the case of fragmentary remains, it was found that epicondylar breadth and AP diameter had the highest probability of accurate stature estimation in the absence of bicondylar femoral length. As stature forms a significant component of a biological profile and therefore aids in the personal identification of human remains, it is important that forensic anthropologists utilize the most accurate methodologies available. Stature estimation of Australian individuals is therefore achieved with higher accuracy through utilizing the femoral equations proposed in this study.

Changes in the Internal Size of the Jugular Vein in Adult Patients with Hypovolemia.

The present study is aimed at establishing the values of internal jugular vein (IJV) anterior-posterior and medial-lateral sizes in patients with hypovolemia. A total of 25 adult Intensive Care Unit patients with hypovolemia were studied. It was found that the anterior-posterior vein size in patients with hypovolemia was significantly less than medial-lateral size during inhalation and during exhalation as well (P < 0.05). Besides, the value of the anterior-posterior size (Dmin) <7 mm was recorded in 20 from 25 patients (80%). At the same time, the medial-lateral size (Dmin) <7 mm was recorded only in six patients (24%). In patients with hypovolemia, the medial-lateral diameter of IJV is more than its anterior-posterior diameter. These data might be useful for justifying the benefits of using lateral access for IJV catheterization under ultrasound imaging in patients with hypovolemia.

Standardized anthropological measurement of postcranial bones using three-dimensional models in CAD software

This study introduces a standardized protocol for conducting linear measurements of postcranial skeletal elements using three-dimensional (3D) models constructed from post-mortem computed tomography (PMCT) scans. Using femoral DICOM datasets, reference planes were generated and plane-to-plane measurements were conducted on 3D surface rendered models. Bicondylar length, epicondylar breadth, anterior-posterior (AP) diameter, medial-lateral (ML) diameter and cortical area at the midshaft were measured by four observers to test the measurement error variance and observer agreement of the protocol (n=6). Intra-observer error resulted in a mean relative technical error of measurement (%TEM) of 0.11 and an intraclass correlation coefficient (ICC) of 0.999 (CI=0.998–1.000); inter-observer error resulted in a mean %TEM of 0.54 and ICC of 0.996 (CI=0.979–1.000) for bicondylar length. Epicondylar breadth, AP diameter, ML diameter and cortical area also yielded minimal error. Precision testing demonstrated that the approach is highly repeatable and is recommended for implementation in anthropological investigation and research. This study exploits the benefits of virtual anthropology, introducing an innovative, standardized alternative to dry bone osteometric measurements.

The development of a quantitative scoring system to predict whether a large-to-massive rotator cuff tear can be arthroscopically repaired.

The aim of the study was to develop a quantitative scoring system to predict whether a large-to-massive rotator cuff tear was arthroscopically reparable prior to surgery. We conducted a retrospective review of the pre-operative MR imaging and surgical records of 87 patients (87 shoulders) who underwent arthroscopic repair of a large-to-massive rotator cuff tear. Patients were divided into two groups, based on the surgical outcome of the repair. Of the 87 patients, 53 underwent complete repair (Group I) and 34 an incomplete repair (Group II). Pre-operative MR images were reviewed to quantify several variables. Between-group differences were evaluated and multiple logistic regression analysis was used to calculate the predictive value of significant variables. The reparability index (RI) was constructed using the odds ratios of significant variables and a receiver operating characteristic curve analysis performed to identify the optimal RI cutoff to differentiate between the two groups. The following variables were identified as independent predictors of arthroscopic reparability: the size of the defect with medial-lateral diameter (cutoff, 4.2 cm) and anterior-posterior diameter (cutoff, 3.7cm); Patte's grade of muscle atrophy (cutoff, grade 3) and Goutallier grade of fatty degeneration (cutoff, grade 3). An RI cutoff value of 2.5 provided the highest differentiation between groups I and II, with an area under the curve of 0.964, and a sensitivity of 73.5% and specificity of 96.2%. The RI developed in our study may prove to be an efficient clinical scoring system to predict whether a large-to-massive rotator cuff tear is arthroscopically reparable. Cite this article: Bone Joint J 2016;98-B:1656-61.

Femoral head reduction osteoplasty for fracture dislocation: A surgical technique

BackgroundFemoral head fractures with subchondral impaction and cartilage loss are difficult to treat successfully. Although multiple surgical management options have been described, no one technique has proven superior, particularly in the young high-demand population. TechniqueA femoral head reduction osteoplasty was performed following a surgical dislocation of the hip. A peripherally based wedge of bone was resected off the damaged central third of the head followed by reduction and fixation of the remaining fragments. This technique resulted in a smaller yet congruent femoral head. MethodsA healthy 40-year old labourer sustained a traumatic crush injury while at work, resulting in a left femoral head fracture dislocation with an associated posterior wall acetabular fracture. Significant femoral head impaction and cartilage loss limited the treatment options. ResultsIntraoperative reduction and postoperative imaging demonstrated near anatomic reconstruction of femoral head with a congruent hip joint. Superiorly at the level of resection, the medial–lateral diameter was reduced by 5–6mm (approximately 12–15% the diameter of the original head) by the osteoplasty. At five years, Harris Hip Score was 86, Oxford Hip Score 36, and UCLA score 89. Hip abductor strength was full, range of motion near normal, and the patient ambulated without antalgia. Radiographs demonstrate a congruent joint and patchy avascular necrosis without collapse. The patient maintained full employment as a labourer. ConclusionsFemoral head reduction osteoplasty is a viable option that may produce durable intermediate-term results for complex femoral head fracture with superior impaction and chondral damage.Level of Evidence: Level V.

A comparison of computed tomography measures for diagnosing cervical spinal stenosis associated with myelopathy: a case-control study.

Study DesignRetrospective comparative study.PurposeTo assess differences in computed tomography (CT) imaging parameters between patients with cervical myelopathy and controls.Overview of LiteratureThere is a lack of information regarding the best predictor of symptomatic stenosis based on osseous canal dimensions. We postulate that smaller osseous canal dimensions increase the risk of symptomatic central stenosis.MethodsCT images and medical records of patients with cervical myelopathy (19 patients, 8 males; average age, 64.4±13.4 years) and controls (18 patients, 14 males; average age, 60.4±11.0 years) were collected. A new measure called the laminar roof pitch angle (=angle between the lamina) was conducted along with linear measures, ratios and surrogates of canal perimeter and area at each level C2-C7 (222 levels). Receiver-operator curves were used to assess the diagnostic value of each. Rater reliability was assessed for the measures.ResultsThe medial-lateral (ML) diameter (at mid-pedicle level) and calculated canal area (=anterior-posterior.×ML diameters) were the most accurate and highly reliable. ML diameter below 23.5 mm and calculated canal area below 300 mm2 generated 82% to 84% sensitivity and 67% to 68% sensitivity. No significant correlations were identified between age, height, weight, body mass in dex and gender for each of the CT measures.ConclusionsCT measures including ML dimensions were most predictive. This study is the first to identify an important role for the ML dimension in cases of slowly progressive compressive myelopathy. A ML reserve may be protective when the canal is progressively compromised in the anterior-posterior dimension.

Odd-impact loading results in increased cortical area and moments of inertia in collegiate athletes

The purpose of this study was to investigate tibial changes in volumetric bone mineral density and geometry that take place in athletes from pre- to post-season. Female college athletes (n=36) and ten controls recruited from the student population were included in the study. Participants had their left tibia scanned by pQCT at 4, 20, and 66% of the overall length from the distal end before and after their competitive seasons. Subjects were divided into four groups: non-athlete (controls, n=10), moderate-impact (cross-country runners, n=13), high-impact (volleyball and basketball, n=11), and odd-impact (soccer, n=12). Anterior-posterior and medial-lateral diameter increased at the 4% site in control subjects. In the moderate-impact group, medial-lateral moment of inertia (MOI) increased by 1.2±1.8 (mean±SD) percent at the 20% site. In high-impact group, anterior-posterior MOI increased by 1.6±2.0 percent at the 66% site. In odd-impact group, cortical area (1.4±2.3%) and cortical thickness (1.8±2.8%) increased at the 20% site increased, as did the polar MOI (1.8±2.2%) at the 66% site. Load-specific changes resulting in improved measures of bone strength take place in athletes during a competitive season. These changes may result in improved resistance to fractures and stress fractures.

Magnetic resonance imaging-based treatment planning for prostate brachytherapy.

Transrectal ultrasound (TRUS) is the standard imaging modality for planning prostate brachytherapy. However, magnetic resonance imaging (MRI) provides greater anatomic detail than TRUS. We compared treatment plans generated using TRUS, endorectal coil MRI (erMRI), and standard body array coil MRI (sMRI). Treatment plans were used from patients treated with permanent, stranded-seed (125)I brachytherapy in a prospective trial. All men underwent pretreatment planning based on TRUS, and all underwent erMRI before treatment and sMRI 30 days after the implant. Treatments for 20 consecutive patients were replanned on sMRI and erMRI images by investigators blinded to TRUS-based plans. Prostate volume/dimensions, radioactivity-to-prostate-volume ratio, and dosimetric parameters were compared. Compared with TRUS, mean prostate volume measured by erMRI was smaller, medial-lateral diameter was larger, and anterior-posterior diameter was smaller, suggesting that the endorectal coil produced anatomic distortions. Craniocaudal prostate length was smaller on both types of MRI thanon TRUS, suggesting that TRUS overestimates prostate length. Activity per volume was 7.5% lower for plans based on sMRI than on TRUS (0.901 vs. 0.974mCi/cm(3), p<0.001). sMRI plans had similar coverage of the planning target volume (PTV) (dose to 90% of the prostate [D(90)] 116.6% sMRI vs. 117.5% TRUS, p=0.526) and improved dose homogeneity (percentage of PTV receiving 150% of the prescription dose [V(150)] 47.4% sMRI vs. 53.8% TRUS, p=0.001 and percentage of PTV receiving 200% of the prescription dose [V(200)] 16.6% sMRI vs. 19.2% TRUS, p<0.001). Staging erMRI should not be routinely used for treatment planning because it produces anatomic distortion. sMRI may have treatment planning advantages over TRUS because of superior soft-tissue delineation of the prostate and adjacent normal tissue structures.

Relationship between the hip joint capsule and piriformis tendon in a simulation of the modified Watson‐Jones anterolateral approach in THA cadaver study

Fifteen fresh frozen cadavers were used for a simulation of the modified Watson-Jones anterolateral approach in an anatomical study. Several parameters were measured to evaluate the relation between the piriformis tendon insertion and hip joint capsule insertion. The anteroposterior diameter of the piriformis tendon was found to be greater than the medial-lateral diameter, and that the posterior part of the incised hip joint capsule is distant from the piriformis tendon as the piriformis is inserted into the extra-articular portion. We also found that it was important not to dissect the anteroproximal portion of the greater trochanter to prevent rupture of the piriformis tendon, whereas the posterior portion was relatively safe.

CT evaluation of upper thoracic spine for surgical application of transarticular screw placement

Although pedicle screw fixation has been increasingly used in the upper thoracic spine in recent years, controversies exist about the safety and complications such as nerve or vascular intrusion associated with the technique. In this study, an alternative method of transarticular screw fixation was validated. Morphometric analysis was performed on computed tomography (CT) scans of the upper thoracic zygapophysial joints of C7, T1, T2 and T3 in 20 male and 20 female patients in the axial and sagittal planes. The degree of screw angulation was recorded in the sagittal and axial planes and the screw length was measured at the spinal level from C7 to T3. The smallest medial-lateral diameter and anterior-posterior diameter of IAP was found at T3 in the female patients and C7 in the male patients. The screw trajectory length ranged from 14.9 to 20.5mm in all patients. All the above measurements were significantly different between male and female patients at all levels (P<0.05). The mean value of screw trajectory angle was 19.3°-20.1° in the axial plane and 44.3°-45.7° in the sagittal plane. There was no statistically significant difference (P>0.05) between male and female patients in the axial and sagittal angles. The morphometric data of C7-T3 zygapophysial joints indicate the suitable screw diameter and screw length for this technique. Transarticular screw fixation proved to be a potentially safe alternative to pedicle screw fixation in this region.

The influence of bony morphology on the magnitude of the pivot shift

The purpose of this study was to correlate clinical pivot shift grading with femoral condyle size as measured on pre-operative magnet resonance imaging (MRI) of patients with anterior cruciate ligament (ACL) injury. Forty-nine consecutive patients for anterior cruciate ligament (ACL) surgery were examined under anesthesia. The pivot shift was graded according to Galway et al. and MacIntosh et al. by a single observer. The grade of pivot shift, Lachman, and collateral laxity was recorded. Intraoperative findings of injury patterns to the ACL and other soft tissue structures were recorded. The anterior-posterior (AP) and medial-lateral (ML) diameter of femoral condyles and tibial plateaus were measured on pre-operative MRI. Patients were grouped into a grade 1 pivot shift group and a grade 2 pivot shift group. ANOVA and independent t tests were used to compare bony dimensions between grade 1 and 2 pivot shifts and by sex. Significance was set at P < 0.05. Twenty-seven patients had a grade 1 pivot shift and 22 a grade 2 pivot shift. Associated pathology was present in 11/27 patients (41%) with a grade 1 pivot shift and 21/22 patients (95%) with a grade 2 pivot shift. The ML diameter of the lateral tibial plateau was significantly smaller in patients with a grade 2 pivot shift (35.5 +/- 3.7 mm) compared to patients with a grade 1 pivot shift (30.3 +/- 3.2 mm; P < 0.05). No difference was detected for any of the other measurements taken (NS). When analyzed by sex this difference existed in women (group I: 31.1 +/- 3.2, group II: 28.8 +/- 2.0; P < 0.05) but not in men (group I: 34.1 +/- 3.7, group II: 33.1 +/- 3.1; NS). All morphologic measurements were larger in men (P < 0.05). A smaller (ML) lateral tibial plateau diameter may contribute to a patient's higher-grade pivot shift. When analyzed by sex this was true for women but not for men. There are other factors contributing to the magnitude of the pivot shift, such as concomitant generalized laxity, injury to the knee joint capsule, and size/or injury of other soft tissue structures that were not analyzed in this study.

Anatomical localization of submandibular gland for botulinum toxin injection

The aim of this study was to document the anatomical landmarks of the submandibular gland (SMG) for a botulinum toxin injection. Thirty-four SMGs from 20 cadavers were examined. The mean length of a reference line between the angle of the mandible and the gnathion was 94.8±5.9mm, the proximal and distal point of the SMG from the angle of the mandible was 10.6% (11.5±3.5mm) and 41.8% (40.9±5.2mm), respectively. The facial artery came out of the SMG at 11.6% (14.6±3.4mm) and the position of the intersection of the facial artery with the inferior border of the mandible was located at 24.4% (28.0±5.5mm) from the angle of the mandible. The shape of the SMG was generally triangular or irregular round on the anatomical position. The mean superior-inferior diameter, anterior-posterior diameter and medial-lateral diameter of the gland was 28.8±4.1, 30.0±6.1 and 15.1±3.5mm, respectively. The safety zone for the injection was 20-35% from the mandible angle on the inferior view and 1.5cm below the inferior line of the mandible on the lateral view. In addition, the needle should be inserted to a depth of 2.0cm from the skin surface on the inferior view. These results may assist in determining a accurate localization of injection sites for the SMG, particularly for injections without ultrasound guidance.