Neck Axis Research Articles

Actual methods of carotid body tumor diagnosis

The aim — to improve the carotid body tumors (CBT) diagnosis.Materials and methods. The article presents with the analysis of the structure and the results of the diagnosis and surgical treatment of 65 patients who were hospitalized in the department of vascular surgery Lviv Regional Clinical Hospital for the period 1995 to 2016. There were 36 cases of carotid body tumor and 29 cases other tumors of the neck, which were directed from other medical institutions with a diagnosis of «carotid body tumor». The examination of patients included physical examination, ultrasonography, computer tomography, MRI. Final diagnosis verification was confirmed with pathological and histological clinical report.Results and discussion. At the initial examination of patients the symptom «plus» tissue was identified palpatory on the neck: left or right side in the projection of the bifurcation of the common carotid artery in 36 patients. In 5 (14 % of the CBT) patients synchronous lesions were found on both sides of the neck in the projection of the bifurcation of the common carotid artery. On palpation the carotid body tumor was of stiffly — elastic consistency, painless, not soldered to surrounding tissues and slightly shifted transverse axis of the neck, pulsing in sync with carotid artery. All patients underwent carotid ultrasonographic examination with the calculated diagnostic sensitivity of ultrasound to detect tumors, that was 93 %, specificity — 92 %, accuracy — 92 %/In the study patients’ ultrasonography was complemented with contrast computer tomography in 14 (22 %) cases and MRI in 2 (3 %). Biopsy of the tumor and sentinel node was performed in 2 (3 %) patients with CBT and 5 (8 %) patients with tumors of different origin. However, biopsy was not informative because received histological material was without specific changes and prevented from identification of tumor genesis pre surgery stage.Conclusions. Ultrasound is a highly informative and specific method for diagnosis of carotid body tumor. USG can be used for differential diagnosis of the neck carotid body tumor from other tumors on pre surgey stage.

The anteroposterior axis of the tibia is adjusted to approximately a right angle to the anterior pelvic plane in the standing position in patients with hip dysplasia similar to normal subjects: a cross-sectional study

BackgroundWe previously described that the anteroposterior (AP) axis of the tibia is approximately perpendicular to the transverse axis of the anterior pelvic plane (APP) in the standing position in healthy subjects. The purpose of this study was to investigate the rotational alignment between the APP and clinical epicondylar axis and the AP axis of the tibia relative to pelvic coordination in the standing position in normal subjects and in women with developmental dysplasia of the hip (DDH) to aid decision making for surgeons in the alignment of implants in total hip or knee arthroplasty.MethodsThis study included 77 Japanese women. Twenty-nine in the DDH group underwent curved periacetabular osteotomy; 48 women without lumbago and knee pain were included in the normal group. Femoral neck anteversion (FNA), condylar twist angle, and knee rotation angle were measured in femoral coordination. The angle between the femoral neck axis and clinical epicondylar axis (CEA) was measured, the transverse axis of the APP was also measured, and the angle between the AP axis of the tibia and transverse axis of the APP was calculated.ResultsThere was a moderate negative correlation between FNA and CEA relative to the APP. This finding indicated a trend towards greater FNA leading to more internal rotation. Knee rotation angle (KRA) relative to the APP was 1.65° ± 5.58° in the normal group and − 2.65° ± 7.57° in the DDH group. This finding indicated that the tibia AP axis was approximately perpendicular to the APP in the standing position both in the normal and DDH groups.ConclusionWe found that the tibia AP axis was at approximately a right angle to the transverse axis of the APP in the standing position in both the normal and DDH groups, while the KRA was different in the normal and DDH groups. These findings may prove helpful for positional alignment investigations needed for implantation in total hip or knee arthroplasty and gait analysis.

The distribution of bone mineral density in the femoral heads of unstable intertrochanteric fractures.

Intertrochanteric fractures are usually treated with open reduction and internal fixation, but controversy still remains regarding the proper placement of the lag screw on the anteroposterior view. The stability of the lag screw has been shown to correlate with the bone quality around the screw, but the three-dimensional distribution of the bone mineral density (BMD) in the femoral head has not been studied in detail. Herein, the BMD along the femoral neck axis was measured to clarify the recommended position of the lag screw. Ten femoral heads acquired from intertrochanteric fractures were evaluated in this study. Each femoral head was scanned with micro computed tomography and the BMD along the femoral neck axis was measured in five regions: center, anterior, posterior, superior, and inferior. The BMD on the anteroposterior view (superior, center, and inferior) and the BMD on the lateral view (anterior, center, and posterior) were compared. The BMD of the center region (173.0 ± 50.6 mg/cm3) was significantly higher than that of the inferior region (139.7 ± 50.1 mg/cm3) on the anteroposterior view ( p < 0.01). On the lateral view, the BMD was lower than the center region in the anterior region (165.7 ± 52.8 mg/cm3) and in the posterior region (157.5 ± 42.3 mg/cm3), but the difference was not significant. The BMD was higher in the center region of the femoral head than in the inferior region. Therefore, lag screws are recommended to be inserted into the center of the femoral head.

Imaging appearance and distribution of intra-articular adhesions following open FAI surgery

ObjectivesTo evaluate the appearance and distribution of intra-articular adhesions on direct MR arthrograms (MRA) in symptomatic patients after surgical hip dislocation (SHD) for the treatment of femoroacetabular impingement (FAI). MethodsAll 18 patients (19 hips) who underwent arthroscopic debridement for treatment of symptomatic adhesions after open surgery of FAI between 2003 and 2012 and that had a complete set of pre- and postoperative direct MRA were evaluated. On radial PD-w images, pre- and postoperative osseous alpha angles were measured. Signal intensity and degree of obliteration of the peripheral compartment of the hip joint were assessed circumferentially at each ‘half-hour’ position and quantified with the adhesion alpha angle (measured between a line connecting the most proximal appearance of adhesions on the femoral neck with the femoral head center and the femoral neck axis). Linear regression analysis was performed between the site of correction and adhesions. As a control group, all patients (9; 9 hips) that underwent revision surgery during the same time period in which adhesions were not the primary cause for revision were evaluated. ResultsFemoral adhesions primarily (47%) appeared as intermediate, complete obliterations correlating with the site of offset correction (R = 0.883, p < 0.001). Adhesion alpha angles were comparable to the pre-operative osseous alpha angles (21/24 positions, p > 0.05) and were greater than the postoperative osseous alpha angles (11/24 positions, p < 0.05). Most labral adhesions (83.2%) appeared as adjacent and correlated with the site of rim trimming (R = 0.777, p < 0.001). In the control group, the most common reason for revision surgery was persisting cam deformity (67%). The radiographic findings were confirmed intra-operatively. ConclusionIntra-articular adhesions most commonly appear at the site of primary offset correction. Recurrent impingement due to scar tissue may be quantified with the adhesion alpha angle. MRA of the hip are suitable to distinguish between postoperative adhesions and other known causes for persisting symptoms.

Surgical therapy of ischiofemoral impingement by lateralizing intertrochanteric osteotomy

Lateralizing, derotating intertrochanteric varus osteotomy to increase the ischiofemoral space to counter painful impingement of the lesser trochanter and the os ischium with resulting entrapment of quadratus femoris muscle. Symptomatic ischiofemoral impingement (IFI) caused by Coxa valga et antetorta, Coxa valga or Coxa antetorta, or ashort femoral neck. Anatomic configuration suggestive of IFI in asymptomatic patients. Symptomatic IFI caused by another underlying pathology. Valgus deformity of the knee. Measurement of femoral antetorsion. Planning of the osteotomy, lateralization, varus angle for correction, rotation and offset correction, leg length change, and osteosynthesis plate. General or spinal anesthesia in supine or lateral position. Skin incision (15 cm) beginning lateral of the greater trochanter tip, distally along the axis of the femur. Preparation onto the femur by L‑shaped dissection of the vastus lateralis from the bone. AKirschner(K-)wire is then positioned along the anterior femoral neck to designate the femoral neck antetorsion. Atriangle set on the lateral femoral cortexis is used to determine the osteotomy angle. In the thus determined angle, asecond K‑wire is shot centrally along the femoral neck axis just inferior to its cranial cortex. About 5 mm distal to the second wire, the entry for the blade is prepared using adrill. Using the blade setting instrument, the blade is introduced into the femoral neck, then slightly pulled back. The rotation is then marked on the anterior femoral cortex proximal and distal to the planned osteotomy and the osteotomy is performed. Ablade plate without displacement is impacted. The osteotomy is then reduced, the distal fragment pulled laterally onto the plate, and the screws inserted after compression of the osteotomy with atension device. Touch-toe bearing for 6weeks, then radiological assessment of osteotomy healing before an increase in weight bearing (15 kg/week). Hip flexion limited to90° for 6weeks. Elective implant removal after 12-18months. Studies of this lateralizing varus osteotomy have not been published. The 25-year results of the conventional derotating intertrochanteric varus osteotomy technique show good functional results and low complication rates, with non-union being the most common. Arthroscopic resection of the lesser trochanter has been reported as asurgical alternative in the treatment of IFI in case reports and small series. Advantages of the osteotomy are the restoration of biomechanics and preservation of iliopsoas tendon insertion.

Ideal screw positions for multiple screw fixation in femoral neck fractures - Study of proximal femur morphology in a Japanese population.

Despite the fact that multiple screw fixation is a common option of surgical treatment for femoral neck fractures, there is a paucity of precise morphological study of the femoral neck. To identify appropriate positions and spacing of hip screws for multiple-screw femoral neck fracture fixation, proximal femur morphology in Japanese patients was studied. One hundred hips in fifty knee arthroplasty candidates were studied. Following full limb CT, defined slices were created and anatomical variables measured. The average neck-shaft angle was 126.5° and the distance from the subcapital line to the subchondral bone on a line parallel to the femoral neck axis (FNA) was approximately 25mm at the superior and inferior; borders of the femoral neck. The FNA was shown to run anterior to the femoral axis (FA). The cross section of the femoral neck forms a reverse right triangle. The height and width of the neck medullary canal were equal (approximately 25mm), with the posterior wall closer to the femoral axis than the anterior wall. Based on these data, the anterior screw positioned just above the calcar femorale, 16mm proximal and 27° anterior to the FA, and the posterior screw positioned 12mm proximal and 5mm posterior to the FA is recommended. For screws inserted with a fixed angle side-plate, ≤130° is recommended.

Folded Radiolarite Unit as a Kinematic Indicator of the Zagros Collision Processes, Southwestern Iran

Radiolarites have an important role in the reconstruction of the paleogeography, bathymetry and their coexistence with ophiolites gives an opportunity to determine the tectonic history of collisional zones. The radiolarite units of the southwestern Neyriz are part of the Zagros accretionary prism and positioned beneath the thick bedded carbonate sediments of Tarbur Formation. The existing various structural elements within this unit give a unique fortunate for investigation on the deformation history and studying of the kinematics of the Zagros collision zone. The numerous evidence show that this unit has experienced different deformation conditions during ongoing evolution, including ductile, brittle-ductile and brittle deformation conditions. The main strike of E-W for axial planes of folds, eastward trend and plunge of fold axes, boudins’ neck axes and Type III of the fold interference patterns are indicators of formation and evolution of folds during transpressional deformation. Structural evolution of the study area has been affected by an NE-dipping subduction zone of Neo-Tethyan oceanic lithosphere below the Iranian microcontinents. These structural elements suggest that high mechanical anisotropy and two successive generations of folding simultaneously with thrusting and extrusion of this unit had led to formation and evolution of this highly asymmetrical folded unit on top of the subducted oceanic crust.

BIOMECHANICAL ANALYSIS OF FEMORAL NECK FRACTURE FIXATION IN SYNTHETIC BONE.

ABSTRACTObjectives To analyze the results of biomechanical assays of the fixation of Pauwels type II femoral neck fractures in synthetic bones, using two parallel cannulated screws or three cannulated screws in an inverted pyramid formation.Methods Ten Brazilian-made synthetic bones were divided into 2 groups. Groups A and B utilized three and two cannulated screws, respectively, after osteotomy in the middle third of the femur, perpendicular to the axis of the femoral neck, simulating a Pauwels type II femoral neck fracture. The resistance of these fixations was analyzed by compression on the axis of the force resulting from hip compression, simulated with a manual hydraulic press. The T-test and post hoc analysis were used to compare the groups, and the significance criterion adopted was p < 0.05.Results In group A, which used fixation with three screws, synthesis failure was seen at a mean force of 526 N. In group B, which used two screws, the mean force was 466 N. The results presented a statistically significant difference (p = 0.02).Conclusion The osteosynthesis of femoral neck fractures in synthetic bone fixated with two screws presented inferior results to fixation with three screws. Level of Evidence III; Case-control study.

Femoral Neck Axis Drawing with Two Parallel Lines in Asymptomatic Adults

Femoral Neck Axis Drawing with Two Parallel Lines in Asymptomatic Adults

Implant Orientation Measurement After THA Using the EOS X-Ray Image Acquisition System.

We investigated the accuracy of measuring implant orientation after THA in standing position using EOS system (EOS Imaging Inc., Paris, France). Ninety patients who underwent THA were subjected to this study by comparing angles measured by EOS system and those measured from CT scans using 3D image analyzing software, ZedHip (LEXI, Tokyo, Japan). The radiographic cup inclination and anatomical cup anteversion were measured with respect to the anterior pelvic plane (APP) coordinate. The femoral stem antetorsion was analyzed by measuring the angles between the stem neck axis and the post-condylar axis in the femoral functional axis coordinate.The differences (mean ± SD) (range of 95%CI) between angles measured by EOS system and those from CT scans in the cup inclination, cup anteversion, and stem antetorsion were - 2.3° ± 2.7° (-2.8°∼ - 1.7°), -0.1° ± 5.0° (-1.2°∼0.9°), and - 1.3° ± 6.5° (-2.7°∼0.1°), respectively. Cup inclination measured on 14 hips, cup anteversion measured on 28 hips, and stem antetorsion measured on 27 hips were classified as outliers whose differences were over 5°. Difficulties in defining the reference points for APP correlated with the incidences of the outliers in cup orientation measurements.We could not set new reference points on the 3D bone surface models reconstructed by EOS system, so we have to use reference points defined on 2D images. In addition, the APP coordinate in EOS system was not the same as the standard definition. EOS system may not be used to measure the implant positions after THA until these problems will be improved.

Influence de l’antéversion fémorale pré-opératoire et de l’orientation du plan d’ostéotomie intertrochantérien sur la morphologie du fémur proximal après ostéotomie intertrochantérienne de rotation : une étude simulée en scanner 3D

BackgroundTranstrochanteric anterior rotational osteotomy (ARO) is joint-preserving surgery for patients with osteonecrosis of the femoral head (ONFH). During ARO, femoral neck-shaft varus angulation by changing intertrochanteric osteotomy plane is often designed to obtain a sufficient post-operative intact ratio. However, the effect of intertrochanteric osteotomy plane on post-operative femoral anteversion has not been well examined. Therefore we performed a simulation study of ARO to determine how intertrochanteric osteotomy plane and pre-operative femoral anteversion affect both femoral neck-shaft varus angle and post-operative femoral anteversion. HypothesisBoth femoral neck-shaft varus angle and post-operative femoral anteversionare predicted by intertrochanteric osteotomy plane and pre-operative femoral anteversion in ARO. Materials and methodsUsing CT-data obtained from 10 hips in 10 patients with ONFH, ARO was simulated. On anteroposterior view, basic intertrochanteric osteotomy line (AP-view line) was defined as the perpendicular line to the femoral neck axis. On lateral view, basic intertrochanteric osteotomy line (lateral-view line) made through the cut surface of greater trochanter was defined as the perpendicular line to the lateral axis of the femur. By changing either AP-view or lateral-view line, 49 ARO models/hip were produced, in which femoral neck-shaft varus angle and post-operative femoral anteversion were assessed. ResultsWith increase in the vertically-inclined degree of AP-view line, both neck-shaft varus angle and post-operative femoral anteversion increased. With increase in the posteriorly-tilted degree of lateral-view line, neck-shaft varus angle increased, whereas post-operative femoral anteversion decreased. The approximation equations based on the multiple regression analyses were as follows: neck-shaft varus angle≈vertically-inclined degree of AP-view line×0.9+posteriorly-tilted degree of lateral-view line×0.8+pre-operative femoral anteversion×0.7; post-operative femoral anteversion≈vertically-inclined degree of AP-view line×1.1–posteriorly-tilted degree of lateral-view line×0.8. DiscussionThe post-operative morphology of proximal femur was nearly defined by intertrochanteric osteotomy plane with pre-operative femoral anteversion, which is useful for pre-operative planning in terms of both achieving asufficient post-operative intact ratio and maintaining femoral anteversion. Level of evidenceLevel IV case series without control group.

The anteroposterior axis of the tibia is approximately perpendicular to the anterior pelvic plane in the standing position in healthy Japanese subjects

BackgroundWe previously reported that the clinical epicondylar axis (CEA) was approximately parallel to the transverse axis of the anterior pelvic plane (APP) in the standing position in normal subjects. The purpose of this study was to investigate the rotational alignment between APP in the standing position and the anteroposterior (AP) axis of the tibia relative to pelvic coordination in normal subjects.MethodsThis study included 68 healthy Japanese, 24 males and 44 females, without lumbago and knee pain. Femoral neck anteversion (FNA), condylar twist angle, and knee rotation angle were measured in femoral coordination. The angle between the femoral neck axis and CEA transverse axis of APP was also measured, and the angle between the AP axis of the tibia and the transverse axis of APP was calculated. The mean value of knee rotation angle was 0.23° and 2.06° in male and female subjects, respectively.ResultsThere was a moderate positive correlation between FNA and the femoral axis angle relative to the transverse axis of APP. The knee rotation angle relative to APP was 0.33° and 1.56° in male and female subjects, respectively, and the tibia AP axis was approximately perpendicular to the transverse axis of APP in the standing position. Regarding validation, we obtained high interclass correlation coefficients for both intraobserver and interobserver reliability.ConclusionWe found that the knee rotation angle was almost 0° and that the tibia AP axis was approximately perpendicular to the CEA. The tibia AP axis was also approximately perpendicular to the transverse axis of the APP in standing position.

Comparative Study of Angle of Inclination and Neck Length of Dry Femur

Background : The angle of inclination of the femur is the angle formed between long axis of neck of femur and long axis of the shaft of femur. The average angle of inclination (neck–shaft angle) is 126°, ranging from 115° to 140° in the adult population. As with the angle of inclination of the humerus, the angle of inclination of the femur varies among individuals and also from side to side. The aim of this study was to determine the Angle of inclination and neck length of Femur.Material &amp; Methods: A total of 50 dry femora (25right and 25 left) of nobel medical college was cross sectionally studied with random sampling without knowing the sex &amp; age of bone. The angle formed between long axis of neck and long axis of the shaft of femur was measured with the help of goniometer. The neck length was measured with the help of sliding calliper.Results: The mean angle of inclination was 128.98±4.55 degrees, on the right side was129.84±5.22 degrees and on the left side was 128.12±3.66degrees. The difference in the mean angle of inclination of right and the left side was found to be statistically insignificant (p value&gt; 0.05). The mean neck length femur was 2.93 ±0.24cm, right femur was 3.06±0.19cm and left femur was 2.80±0.21cm. The difference in the mean neck neck length of the right and the left side was found to be statistically insignificant (p value&gt; 0.05).Conclusion: The Angle of Inclination of Femur and neck length of femur in present study had no remarkable dissimilarity with the results observed in the studies conducted in Nepal and neighbouring countries. In the study there was no statistical significant difference between the neck-shaft angle and neck length of femur of right and left side of the femur but there was positive correlation between angle of inclination and neck length of femur.Journal of Nobel Medical CollegeVolume 6, Number 1, Issue 10 (January-June, 2017), Page: 44-47

Effects of intertrochanteric osteotomy plane and preoperative femoral anteversion on the postoperative morphology of the proximal femur in transtrochanteric anterior rotational osteotomy: 3D CT-based simulation study

BackgroundTranstrochanteric anterior rotational osteotomy (ARO) is joint-preserving surgery for patients with osteonecrosis of the femoral head (ONFH). During ARO, femoral neck-shaft varus angulation by changing intertrochanteric osteotomy plane is often designed to obtain a sufficient postoperative intact ratio. However, the effect of intertrochanteric osteotomy plane on postoperative femoral anteversion has not been well examined. Therefore, we performed a simulation study of ARO to determine how intertrochanteric osteotomy plane and preoperative femoral anteversion affect both femoral neck-shaft varus angle and postoperative femoral anteversion. HypothesisBoth femoral neck-shaft varus angle and postoperative femoral anteversion are predicted by intertrochanteric osteotomy plane and preoperative femoral anteversion in ARO. Materials and methodsUsing CT-data obtained from 10 hips in 10 patients with ONFH, ARO was simulated. On anteroposterior view, basic intertrochanteric osteotomy line (AP-view line) was defined as the perpendicular line to the femoral neck axis. On lateral view, basic intertrochanteric osteotomy line (lateral-view line) made through the cut surface of greater trochanter was defined as the perpendicular line to the lateral axis of the femur. By changing either AP-view or lateral-view line, 49 ARO models/hip were produced, in which femoral neck-shaft varus angle and postoperative femoral anteversion were assessed. ResultsWith increase in the vertically-inclined degree of AP-view line, both neck-shaft varus angle and postoperative femoral anteversion increased. With increase in the posteriorly-tilted degree of lateral-view line, neck-shaft varus angle increased, whereas postoperative femoral anteversion decreased. The approximation equations based on the multiple regression analyses were as follows: neck-shaft varus angle≈vertically-inclined degree of AP-view line×0.9+posteriorly-tilted degree of lateral-view line×0.8+preoperative femoral anteversion×0.7; postoperative femoral anteversion≈vertically-inclined degree of AP-view line×1.1−posteriorly-tilted degree of lateral-view line×0.8. DiscussionThe postoperative morphology of proximal femur was nearly defined by intertrochanteric osteotomy plane with preoperative femoral anteversion, which is useful for preoperative planning in terms of both achieving a sufficient postoperative intact ratio and maintaining femoral anteversion. Level of evidenceLevel IV case series without control group.

Femoral neck shortening in adult patients under the age of 55 years is associated with worse functional outcomes: Analysis of the prospective multi-center study of hip fracture outcomes in China (SHOC)

IntroductionYoung femoral neck fracture patients require surgical fixation to preserve the native hip joint and accommodate increased functional demands. Recent reports have identified a high incidence of fracture shortening and this may have negative functional consequences. We sought to determine if fracture shortening is associated with poor functional outcome in young femoral neck fracture patients. Patients and methodsOne hundred and forty-two patients with femoral neck fractures age 18–55 were recruited in this prospective cohort study across three Level 1 trauma hospitals in Mainland China. Patient-reported and objective functional outcomes were measured with the Harris Hip Score (HHS), Timed Up and Go (TUG), and SF-36 Physical Component Summary (SF-36 PCS) at 12 months. Radiographic fracture shortening was measured along the long axis of the femoral neck and corrected for magnification. Severe shortening was defined as ≥10mm. The primary analysis measured associations between severe radiographic shortening and HHS at one-year post-fixation. ResultsOne hundred and two patients had complete radiographic and functional outcomes available for analysis at one year. The mean age of participants was 43.7±10.8years and 53% were male. Fifty-five percent of fractures were displaced and 37% were vertically orientated (Pauwels Type 3). The mean functional outcome scores were: HHS 90.0±10.8, TUG 12.0±5.1s, and PCS 48.5±8.6. Severe shortening occurred in 13% of patients and was associated with worse functional outcome scores: HHS mean difference 9.9 (p=0.025), TUG mean difference 3.2s (p=0.082), and PCS mean difference 5.4 (p=0.055). ConclusionsSevere shortening is associated with clinically important decreases in functional outcome as measured by HHS following fixation of young femoral neck fractures, occurring in 13% of patients in this population. The principle of fracture site compression utilized by modern constructs may promote healing; however, excessive shortening is associated with worse patient-reported outcomes and objective functional measures.

Structural Parameters of the Proximal Femur by 3-Dimensional Dual-Energy X-ray Absorptiometry Software: Comparison With Quantitative Computed Tomography

Structural parameters of the proximal femur evaluate the strength of the bone and its susceptibility to fracture. These parameters are computed from dual-energy X-ray absorptiometry (DXA) or from quantitative computed tomography (QCT). The 3-dimensional (3D)-DXA software solution provides 3D models of the proximal femur shape and bone density from anteroposterior DXA scans. In this paper, we present and evaluate a new approach to compute structural parameters using 3D-DXA software. A cohort of 60 study subjects (60.9 ± 14.7 yr) with DXA and QCT examinations was collected. 3D femoral models obtained by QCT and 3D-DXA software were aligned using rigid registration techniques for comparison purposes. Geometric, cross-sectional, and volumetric structural parameters were computed at the narrow neck, intertrochanteric, and lower shaft regions for both QCT and 3D-DXA models. The accuracy of 3D-DXA structural parameters was evaluated in comparison with QCT. Correlation coefficients (r) between geometric parameters computed by QCT and 3D-DXA software were 0.86 for the femoral neck axis length and 0.71 for the femoral neck shaft angle. Correlation coefficients ranged from 0.86 to 0.96 for the cross-sectional parameters and from 0.84 to 0.97 for the volumetric structural parameters. Our study demonstrated that accurate estimates of structural parameters for the femur can be obtained from 3D-DXA models. This provides clinicians with 3D indexes related to the femoral strength from routine anteroposterior DXA scans, which could potentially improve osteoporosis management and fracture prevention.

Türk Toplumunda Proksimal Femurun Geometrik Özelliklerinin Radyolojik Değerlendirilmesi

Objective : The aim of this study is to assess different features of the proximal femoral geometry of the Turkish population to build a database for surgeons and implant manufacturers. Methods : 380 (190 male, 190 female) antero-posterior direct radiography of pelvis of 40-80 years old patients were reviewed retrospectively. The femoral head diameter, horizontal offset, neck shaft angle, femoral neck width, femoral neck length and the femoral axis length were measured. Results : In both genders, there was statistically significant difference between right and left hips at femoral head diameters and horizontal offset of hip. No significant difference was detected at the measurements of neck-shaft angle, femoral neck width, femoral neck length and femoral neck axis length. Conclusion : Male population most of the time present higher average values than the female population. This study may offer a data base for surgeons and manufacturers who deal with proximal femoral bone surgery.

Virtual Experimental Validation of Dynamic Osteosynthesis in the Treatment of Fractures of the Proximal Femur.

Volume model of transtrochanteric fracture of the femoral bone fixed by Targon PF dynamic fixator was studied by the finite element analysis. The following parameters were measured: magnitude and direction of displacement of system elements, pressure between fragments, and von Mises stress distribution in the fixator depending on support screw plunging into the sleeve. The results indicate that stability of the bone-nail system increases during fracture union and 10-mm shortening of the femoral neck axis, which is seen from a decrease in system deformation under load by 16.8%, stress in the implant by 20.2%, and pressure in the zone of fragments contact by 19.8%.

Bi-planar robot navigation for cannulated screw fixation in the treatment of femoral neck fractures

Objective To investigate the clinical results of Bi-plane robot navigation for cannulated screw fixation in the treatment of femoral neck fractures. Methods Between May 2011 and May 2015, 86 patients with femoral neck fracture who were fixed with cannulated screws were retrospectively analyzed. The patients were divided into navigation group and non-navigation group according to whether the Bi-planar robot used for navigation or not. The patients were matched concerning gender, age and Garden classification. A total of 64 patients were included in the study. In navigation group, there were 32 cases, including 10 males and 22 females. The average age was 59.4±5.6 yr (range, 51-68 yr). According to Garden classification, there were 1 case of type I, 7 cases of type II, 14 cases of type III and 10 cases of type IV. In non-navigation group, there were 32 cases, including 12 males and 20 females. The average age was 59.1±4.9 yr (range, 53-70 yr). According to Garden classification, there were 1 case of type I, 5 cases of type II, 18 cases of type III and 8 cases of type IV. Sixty-four cases were all fixed with cannulated screws. The fluoroscopy time, fluoroscopy times, drilling times, times of cannulated screw replacement, cannulated screw insertion time, blood loss, relative position between any two cannulated screws in postoperative AP view and lateral view, the angle between each cannulated screw and the femoral neck axis, fracture healing time and functional score were recorded. Results The parameters in navigation group versus non-navigation group were as follows: the average fluoroscopy time was 10.1±2.9 s vs 36.8±7.5 s, the average fluoroscopy times was 11.4±3.2 vs 43.9±11.0, the average drilling times was 3.9±1.1 vs 18.5±3.2, the average times of cannulated screw replacement was 0.4±0.6 vs 1.0±0.7; the average blood loss was 29.4±14.7 ml vs 50.2±17.1 ml, cannulated screws placement time averaged 28.8±7.3 min vs 43.8±7.9 min. The angle between any of two cannulated screws averaged 3.1°±1.1° vs 7.3°±1.2° in AP view and 2.9°±1.0° vs 4.4°±2.3° in lateral view, the angle between the cannulated screw and the femoral neck axis averaged 4.4°±1.6° vs 7.5°±1.7° in AP view and 4.9°±1.6° vs 8.0°±1.3° in lateral view. Significant differences were found concerning all above parameters between the two groups. Conclusion Bi-plane robot navigation technique helps more accurate cannulated screw fixation in the treatment of femoral neck fracture. This technique is less invasive. It decreases the time of screw insertion and reduces the radiation exposure. Key words: Robotics; Surgery, computer-assisted; Femoral neck fractures; Internal fixators

CUSTOMIZED GUIDE FOR FEMORAL COMPONENT POSITIONING IN HIP RESURFACING ARTHROPLASTY.

ABSTRACTObjective: To prove the accuracy of a customized guide developed according to our method. Methods:This customized guide was developed from a three-dimensional model of proximal femur reconstructed using computed tomography data. Based on the new technique, the position of the guide pin insertion was selected and adjusted using the reference of the anatomical femoral neck axis. The customized guide consists of a hemispheric covering designed to fit the posterior part of the femoral neck. The performance of the customized guide was tested in eight patients scheduled for total hip arthroplasty. The stability of the customized guide was assessed by orthopedic surgeons. An intraoperative image intensifier was used to assess the accuracy. Results: The customized guide was stabilized with full contact and was fixed in place in all patients. The mean angular deviations in relation to the what was planned in anteroposterior and lateral hip radiographs were 0.5º ± 1.8º in valgus and 1.0º ± 2.4º in retroversion, respectively. Conclusion: From this pilot test, the authors suggest that the proposed technique could be applied as a customized guide to the positioning device for hip resurfacing arthroplasty with acceptable accuracy and user-friendly interface. Level of Evidence IV, Cases Series.