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Intervertebral discs are fibrocartilage structures, which play a role in buffering the compression applied to the vertebral bodies evenly while permitting limited movements. According to several previous studies, degenerative changes in the intervertebral disc could be accelerated by factors, such as aging, the female sex, obesity, and smoking. As degenerative change progresses, the disc height could be reduced due to the dehydration of the nucleus pulposus. This study aimed to quantitatively analyze the pressure that each structure of the spine receives according to the change in the disc height and predict the physiological effect of disc height on the spine. We analyzed the biomechanical effect on spinal structures when the disc height was decreased using a finite-element method investigation of the lumbar spine. Using a 3D FE model, the degree and distribution of von-Mises stress according to the disc height change were measured by applying the load of four different motions to the lumbar spine. The height was changed by dividing the anterior and posterior parts of the disc, and analysis was performed in the following four motions: flexion, extension, lateral bending, and axial rotation. Except for a few circumstances, the stress applied to the structure generally increased as the disc height decreased. Such a phenomenon was more pronounced when the direction in which the force was concentrated coincided with the portion where the disc height decreased. This study demonstrated that the degree of stress applied to the spinal structure generally increases as the disc height decreases. The increase in stress was more prominent when the part where the disc height was decreased and the part where the moment was additionally applied coincided. Disc height reduction could accelerate degenerative changes in the spine. Therefore, eliminating the controllable risk factors that cause disc height reduction may be beneficial for spinal health.

Kyphoplasty (KP) is a surgery used to reduce pain and increase stability by injecting medical bone cement into broken vertebrae. The purpose of this study was to determine the ideal amount of cement and injection site by analyzing forces with the finite element method.We modeled the anatomical structure of the vertebra and injected the cement at T12. By increasing the amount of cement from 1 cc to 22 cc, stress applied to T11 and L1 cortical was calculated. In addition, stress applied to the adjacent KP level was calculated with different injection sites (medial, anterosuperior, posterosuperior, anteroinferior, and posteroinferior). After 5 cc cement was inserted, adjacent end plate stress was analyzed.In this study, break point adjacent bone stress according to the capacity of cement was bimodal. Flexion/extension and lateral bending conditions showed similar break points (11.5-11.7 cc and 18.5-18.6 cc, respectively). When cement injection was changed, front under and back under had the highest stress values among various parts, whereas the center position showed the lowest stress value.With increasing amount of bone cement, stress on the upper and lower end plates of the cemented segment increased significantly. Thus, increasing cement amount to be more than 11.5 cc has a potential risk of adjacent fracture. Centrally injected bone cement can lower the risk of adjacent fracture after percutaneous KP.

Background Despite widely use of femoral neck system system (FNS®), there is little evidence for mechanical property according to type of femoral neck fracture. This study is to assess the structural/mechanical stability of fixation constructs with a femur neck system by using the finite-element (FE) analysis after simulating the femur neck fractures and to introduce the clinical implications. Methods We simulated the fracture models of subcapital, transcervical, basicervical, and vertical types by using the right femur model (SAWBONES®) and imported the implant model of FNS® to ANSYS® to place the implant in the optimal position. The distal end of the femur model was completely fixed and was abducted 7°. The force vector was set laterally at an angle of 3° and posteriorly 15° in the vertical ground. We did the analysis using Ansys® software with the von Mises stress (VMS) in megapascal (MPa). Results The max VMS of the fracture site was 67.01 MPa for a subcapital fracture, 68.56 MPa for a transcervical fracture, 344.54 MPa for a basicervical fracture, and 130.59 MPa for a vertical fracture. The max VMS of FNS® was 840.34 MPa for a subcapital fracture, 637.37 MPa for a transcervical fracture, 464.07 MPa for a basicervical fracture, and 421.01 MPa for a vertical fracture. The max VMS of the implant corresponded to the value of the entire fixation construct and thus, FNS® mainly functions as a load-bearing implant. When we compared the basicervical and vertical fractures, the stress distribution between the implant and the fracture sites differed significantly, and the basicervical fracture had higher VMS in the bone, implant, and fracture sites. Conclusion Considering the stress distribution of the assembly model, FNS® fixation should consider the osseous anchorage between the proximal bolt and cancellous bone of femoral head and might be appropriate for vertical fractures. Regarding the VMS of fracture site, FNS® might be applied cautiously just in the basicervical fracture of anatomical reduction without gap and comminution.

PURPOSE To assess the conformity of PFNA-II® and introduce clinical implications of new cephalomedullary nail (CMN) by analyzing three-dimensional (3D) modeling with virtual implantation at the actual size. MATERIALS AND METHODS Thirty-four patients (average age; 79 years, range 68-94 years) who sustained the intertrochanteric fracture of the femur were enrolled in the present study. After importing into Mimics® software, the intact femurs on the opposite side were selected as cropping areas to reconstruct the 3D femur model with the medullary canal. PFNA-II® and new CMNs (lateral angle 0° and 2°, CCD angle 130°; CMN0° and CMN2°) were processed at the actual size and ideally placed in the proximal femur using Mimics® software. The virtual entry point (EP), nail conformity, and anatomical relationships with the adjacent structures were assessed. RESULTS The virtual EP of PFNA-II® was placed along the cervico-trochanteric (CT) junction in the posterior half around trochanteric fossa and always medial to the tip of greater trochanter (GT). There were six abutments in PFNA-II® models, one impingement in CMN 0°, and no impingement in CMN 2°. All the models with cortical abutment showed increased anterior and lateral bowing of the proximal shaft owing to age-dependent changes. Compared with PFNA-II®, with a decreasing tendency on the mediolateral angle of new CMNs, the virtual EP shifted to the medial and anterior side towards the CT junction. By simulating the intentional positioning in the media-to-lateral direction, the abutments in the PFNA-II® model could not be avoided. Furthermore, the lag screw of CMN 0° was placed ideally at the center or inferior side of the femoral head < 10 mm in any direction without a cortical abutment. CONCLUSION To avoid cortical abutment of CMN in the Asian geriatric femur, the virtual EP would be technically placed in the medial to the GT tip, and the implant design should be changed to decrease the mediolateral angle.

This present study was conducted to determine the structural-mechanical stability of various fixation constructs through finite element (FE) analysis following simulation of a basicervical fracture and to introduce the clinical implications.We simulated fracture models by using a right synthetic femur (SAWBONES®). We imported the implant models into ANSYS® for placement in an optimal position. Five assembly models were constructed: (1) multiple cancellous screws (MCS), (2) FNS (femoral neck system®), (3) dynamic hip screw (DHS), (4) DHS with anti-rotation 7.0 screw (DHS + screw), and PFNA-II (Proximal Femoral Nail Antirotation-II®). The femur model's distal end was completely fixed and 7° abducted. We set the force vector at a 3° angle laterally and 15° posteriorly from the vertical ground. Analysis was done using Ansys® software with von Mises stress (VMS) in megapascals (MPa) and displacement (mm) RESULTS: The displacements of the proximal femur were 10.25 mm for MCS, 9.66 mm for DHS, 9.44 mm for DHS + screw, 9.86 mm for FNS, and 9.31 mm for PFNA-II. The maximum implant VMS was 148.94 MPa for MCS, 414.66 MPa for DHS, 385.59 MPa for DSH + screw, 464.07 MPa for FNS, and 505.07 MPa for PFNA-II. The maximum VMS at the fracture site was 621.13 MPa for MCS, 464.14 MPa for DHS, 64.51 MPa for DHS + screw, 344.54 MPa for FNS, and 647.49 MPa for PFNA-II. The maximum VMS at the fracture site was in the superior area with the high point around the posterior screw in the MCS, anterosuperior corner in the DHS, the posteroinferior site of the FNS, and posterosuperior site around the entry point in the PFNA-II. In the DHS + screw, the stresses were distributed evenly and disappeared at the maximum VMS fracture site.Based on the fracture site and implant's stress distribution, the model receiving the optimal load was a DHS + screw construct, and the FNS implant could be applied to anatomically reduced fractures without comminution. Considering the high-stress concentration around the entry point, a PFNA-II fixation has a high probability of head-neck fragment rotational instability.

Background: To determine the optimal direction of the syndesmotic screw and introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation.Methods: A total of 102 cadaveric lower legs (50 males and 55 females, average height of 160.6 ± 7.1cm) were used to reconstruct a 3D model by using the Mimics® software and the joint morphology was evaluated. Syndesmotic cylinders (Ø3.5 mm/Length 100 mm) were transversely placed in the proximal end of the incisura fibularis for simulating screw fixation. The tibial proximal cylinder, which was tangent to the posterior tibial condyles, was traced and the angle between the two cylinders was measured as the tibial torsion angle (TTA). After rotating the syndesmotic cylinder parallel to the ground, the overlapping degree between the proximal fibula and tibia were assessed as a radiologic indicator. Results: Concerning tibial torsion, the TTA was an average of 36.7° (range, 17.2°–54.4°, SD 8.78) When the syndesmotic cylinder was rotated to be parallel to the ground, the proximal fibula had non- or linear overlap with the lateral border of the tibia, regardless of the joint morphology. In this nonoverlapping view, compared to the mortise view, the three criteria for normal fibular length could be better visualized. Conclusion: The syndesmotic cylinder in the proximal end of the incisura fibularis could be consistently placed parallel to the ground by internally rotating the tibia until there was a non- or linear overlap between the proximal fibula and the tibia, regardless of the joint morphology.

(1) To analyze three-dimensional (3D) morphologic features of atypical femur fracture at actual size without projection error; and (2) to provide clinical implications of cephalomedullary nail (CMN) fixation by separating the medullary canal and the cortex.Fifty-nine atypical femurs (opposite non-fractured femurs) were reconstructed as 3D models with medullary canal by importing CT data into Mimics® software. A reference line was drawn from the tip of the greater trochanter to the center of the intercondylar notch and used for classifying bowing grade according to the centerline of medulla. Proximal and distal straight lines (length of 60 mm, diameter of 1 mm) were placed in the centerline of medulla. Acute angles between the two straight lines were measured as lateral and anterior bowing. The acute angle by straight line and reference line was measured as proximal and distal bowing in both AP and lateral view. The diameter of curve (DOC) of medulla along the posterior border was measured.The anterior bowing of all femur on lateral view was an average of 13.82° (range, 6.2°-31.1°, SD 3.91), and the values of proximal and distal anterior bowing were an average of 7.82° (range, 2.7°-14.3°, SD 2.23) and 6.0° (range, 2.2°-16.8°, SD 2.31), respectively. The lateral bowing of all femur on AP view was an average of 5.49° (range, 0.1°-17.3°, SD 4.48), and the values of proximal and distal anterior bowing were an average of 3.64° (range, 0.1°-11.3°, SD 2.70) and 2.48° (range, 0-7.4°, SD 1.98), respectively. The medullary canal was changed to be straightened and more bowed anteriorly. Concerning the lateral bowing grade of entire diaphysis, it was grade -I for 15 femurs, grade 0 for 21 femurs, grade I for nine femurs, grade II for five femurs, and grade III for nine femurs. Regarding anterior bowing grade, it was grade II for 14 femurs and grade III for 45 femurs. The average diameter of medullary canal was 1276.3 ± 232.25 mm.Asian atypical femur had three morphologic features: (1) straightened medullary canal, (2) positive values of lateral bowing, and (3) significantly increased ante-curvature of medullary canal. Considering that conventional CMN had about 4° of mediolateral angle, the disparity between implant and medullary canal might be clear. Thus, new nail design for Asian atypical femur that could increase the radius of curve (ROC) but decrease the mediolateral angle needs to be introduced.

Background Transiliac–transsacral (TITS) screw fixation might be necessary in some cases involving the vertical shearing injuries with transforaminal fracture and bilateral posterior ring injuries. However, the possibility of S1 TITS screw should be preoperatively assessed because the pelvic ring injuries with sacral dysmorphism had the insufficient osseous corridors. Hypothesis AxWS2 may predict the possibility of TITS screw fixation and be used as the new indicator to discriminate the sacral dysmorphism. Materials & methods The conventional CT images of eighty-two cadaveric pelvis imported into Mimics® software to reconstruct three-dimensional (3D) models. A 7.0 mm-sized screw was processed into a 3D model using a 3D-sensor at actual size and virtually implanted as S1 and S2 TITS screw using Mimics® software. The cortical violation around screw path was evaluated using 3D biplanar and conventional CT images. The osseous corridor widths around TITS screws were measured in the axial plane images and defined as AxWS1 and AxWS2, respectively. Results Despite no cortical violation in S2 of all models, cortical violation of S1 TITS screw was found in 20 models. Of them, 14 models (impossible models) were identified in the 3D biplanar images, and all 20 models (CT-violation models) were identified only in CT axial plane images. AxWS1 was Discussion By using AxWS2, the possibility of S1 TITS screw fixation could be predicted and safely placed without cortical violation, if AxWS2 was less than 13 mm. Considering the negative relationship with AxWS1, AxWS2 should be used as a new indicator to predict safe S1 TITS screw fixation. Level of evidence III, controlled laboratory study.

Introduction To determine the optimal entry point (EP) of intramedullary nail (IMN) fixation and introduce a consistent landmark for practical application by analyzing three-dimensional (3D) modeling and virtual implantation. Materials and methods A total of 104 cadaveric femurs (50 males and 54 females) underwent continuous 1.0 mm slice computed tomography (CT) scans. CT images were imported into Mimics® software to reconstruct 3D model of tibiofibular bone with medullary canal. Expert Tibial Nail (ETN®, O12mm/Length 315 mm) was processed into a 3D model at the actual size and optimally implanted in the tibia. After IMN was aligned in a neutral position, it was defined as a true AP projection. In the true AP projection, optimal EP and relationship with adjacent structures were assessed based on the degree of tibial rotation. Results EP was placed eccentrically around the lateral tibial spine in cephalad view and in true AP projection in all models. In true AP projection, the overlapping point between fibular tip and cortical margin of lateral condyle was placed lateral to the fibular tip in 62 models, and exactly matched with fibular tip in 42 models. As tibia rotates, the position of EP in the AP view changes. When tibia was externally rotated, EP was located to the lateral, not the medial side of the lateraltibialspine. The obliquity of guide wire also changed withtibialrotation; the obliquity of guide wire aligned in a straight in true AP projection. Conclusion Optimal determination of EP and guide wire direction should be performed by considering the overlapping point that should be placed to just or lateral side of fibular tip in AP projection. Compared with fibular bisector line, the overlapping point is also useful as a practical landmark for making true AP projection and determining optimal EP.

Introduction Ilio-sacral screw fixation has been used for sacral fractures and sacroiliac joint dislocations. However, it is associated with significant complications including screw loosening with backing-out and loss of reduction. Trans-sacral screw fixation is indicated for rigid fixation in specific circumstances including bilateral posterior ring injuries, osteoporotic bone, or to supplement other types of posterior ring fixation. Hypothesis The reformatting the CT scanning plane may distinguish sacral dysmorphism and predict the possibility of trans-sacral screw fixation by introducing the new indicator. Material and methods The CT data of 112 adult cadavers (61 males and 51 females) were imported into Mimics® software and a 7.0 mm-sized trans-sacral screw was virtually placed in the ideal position of S1. The osseous widths around screw in the axial images (AxWS1) were measured. By reformatting the CT scanning plane parallel to the superior endplate of S1, the AxWRS1 was measured and the height of elevated segment in the upper sacrum (elevated height) was assessed as a new preoperative indicator. Results Cortical violation around screw was detected in 26 models and was considered as sacral dysmorphism. The average AxWS1 was measured as 13.70 ± 2.76 mm in the non-dysmorphism group, and 5.81 ± 2.19 mm in the dysmorphism group, with statistical difference (p Discussion By reformatting the CT scanning plane, the osseous width around screw was widened, and the new preoperative indicator of elevated height could be introduced to predict the possibility of trans-sacral screw fixation into S1. If the elevated height exceeded 13 mm, the pelvis was assigned to sacral dysmorphism and thus, could not apply the trans-sacral screw fixation into S1. Level of evidence III, controlled laboratory study.

Purpose: This study aims to investigate the difference in physiological loading on the spine in three different motions (flexion-extension, lateral bending, and axial rotation) between osteoporotic and normal spines, using finite element modelling.Methods: A three-dimensional finite element (FE) model centered on the lumbar spine was constructed. We applied two different material properties of osteoporotic and normal spines. For the FE analysis, three loading conditions (flexion-extension, lateral bending, and axial rotation) were applied.Results: The load was higher on the nucleus pulposus at all vertebral levels in all movements, in the osteoporosis group than in the normal group. On the annulus fibrosus, the load increased at the level of L3-L4, L4-L5, and L5-S in the flexion-extension group and at L4-L5 and L5-S levels in the lateral bending group. The values of flexion-extension and lateral bending increased in two motions in the L4 and L5 cortical bones and in axial rotation at the level of L5. Additionally, the load increased in the lower endplate of L5-S and L4-L5 in all movements, especially lateral bending. Even in the group with no increase, there was a part that received increased load locally for each element in the three-dimensional reconstructed view of the pressure distribution in color.Conclusion: The load on the lumbar region in the three loading conditions, was greater in most components of osteoporotic vertebrae than in normal vertebrae and the value was highest in the nucleus pulposus. Considering the increase in the measured load and the local increase in the pressure distribution, we believe that these results can contribute to explaining discogenic pain and degeneration.

Purpose: The objective of this study was to improve the three-dimensional (3D) understanding of optimal lateral cortical hinge in medial open-wedge high tibial osteotomy (MOWHTO) via a computational cadaveric simulation of actual size. Methods: The computed tomography data of 117 adult cadavers were imported into Mimics® software to design 3D models of tibia and fibula. To simulate the MOWTHO, a virtual cutting plane was developed inside the safe zone based on established landmarks. After splitting and distracting through the cutting plane, the 10-mm cylinder (Ø 30 mm; height 10 mm) was placed vertically to be occupied properly in the nonosteotomized lateral cortex. The cross points between the round cylinder and cutting plane represented the anterior and posterior hinge points, which were used to validate the 3D position and direction of cortical hinge. Results: A 10-mm cylinder did not violate the proximal tibiofibular joint (PTFJ) and the protruding segment of the condylar area was less than 2 mm in 115 models. The connecting line between anterior and posterior hinge points was an average of 12.1° (range 0–24.1°, SD 4.64) to the lateral side. In the nonoverlapping anteroposterior projection between proximal fibula and tibia, the posterior hinge point was laid over the PTFJ as close as possible. Based on free 360° rotation and magnification without any tilt, no posterior cortical disruption of PTFJ was observed while securing a minimum width of 10 mm. Conclusion: If the posterior hinge point was placed immediately above the PTFJ without involvement, the nonosteotomized portion carried sufficient width greater than 10 mm, despite lateral rotation at an average hinge direction of 12.1°.

Purpose The aim of this study is to conduct clinical and radiographic evaluations of the use of percutaneous bridge plating for distal fibular fractures combined with distal tibia type III open fractures. Methods Thirty-four patients with acute distal third fibular shaft fractures (4F2A(c) and 4F2B(c) according to the AO/OTA classification) combined with distal tibia type III open fractures were enrolled. Concurrent fibular fractures were fixed with the percutaneous bridge plating simultaneously, while distal tibia open fractures were temporally stabilized with a spanning external fixator. Clinical and radiographic outcomes were evaluated using the Lower Extremity Functional Scale (LEFS), the proportional length difference of the fibula, the talocrural angle, the union rate of the fibula and tibia, the operation time, and complications at the final follow-up. Results All fibular fractures healed with an average bone healing time of 20.7 ± 6.3 weeks (range, 16–35). The mean proportional length difference was 0.492 ± 0.732% compared with that in the uninjured fibula. The functional assessment result according to the LEFS was 74.0 ± 3.70 points (range, 57–80). No cases of fibula fracture infection developed throughout the follow-up period in any of the patients. Iatrogenic postoperative superficial peroneal nerve injury was not found in any of the patients. Conclusion With the perspective of minimizing soft tissue problems due to high-energy trauma, the application of percutaneous bridge plating for the treatment of distal fibular fractures can be an alternative to conventional treatment methods.

Purpose We introduced the intraoperative radiological indicator to assess the reduction adequacy without additional procedure or instrument, and propose the optimal syndesmotic screw trajectory. Methods Thirty adult cadavers (15 males and 15 females) without ankle problems were enrolled and subjected to continuous 0.75 mm-slice computed tomography (CT) scans. CT images were imported into Mimics® software to reconstruct three-dimensional (3D) model of ankle. Using free 360° rotations with magnification, the 3D mutual relationships of ankle syndesmosis were assessed, and the fibular congruency of incisura was evaluated to determine the optimal screw trajectory. By reformatting the CT scanning plane along the screw direction, the coronal relation of ankle syndesmosis was evaluated to verify the distance between the adjacent bones. Results The fibula was placed in the concentric position of fibular incisura in the 20 models (concentric group) and 40 models, in an eccentric position (eccentric group). Despite this variant, all fibulas were changed into the concentric position in the proximal part of syndesmotic footprint, which might be the ideal height for syndesmotic screw in our study. The fibular bisecting screw trajectory associated with the ideal height of screw was parallel to the ground if the tibial tubercle was directed to the superior and nearly vertical to the ground floor (TT view). Through the reformatted scanning plane parallel to the screw, the lateral border of talus was always placed more medial than the lateral border of distal tibia in the coronal image. All models had a perfectly equidistant and parallel joint space except the medial aspect. Conclusion The lateral border of talus in the TT view was intraoperatively used as the radiological indicator for ankle syndesmosis widening because it was always placed more medial than the lateral border of distal tibia. The optimal syndesmotic screw trajectory was placed around the proximal syndesmotic footprint and parallel to the ground via the TT view.

Objective The fluoroscopically-guided procedure of antegrade posterior lag screw in posterior column fixation through anterior approach is technique-dependent and requires an experienced surgeon. The purpose of this study was to establish the safe zone for the antegrade posterior lag screw by using computational analysis. Method The virtual three-dimensional model of 178 hemi-pelvises was created from the CT data (DICOM format) by using Mimics® program, and were used to measure the safe zone of antegrade lag screw fixation on the inner table of the iliac wing, and the largest diameter of cylindrical implant inside safe zone. The central point (point A) of the cylinder was assessed and was compared with the intersection point (point B) between the linea terminalis and the anterior border of the sacroiliac articulation. Results The safe zone was triangular with an average area of 670.4 mm2 (range, 374.8–1084.5 mm2). The largest diameter of the cylinder was a mean 7.4 mm (range, 5.0–10.0 mm). When height was under 156.3 cm, the diameter of the cylindrical implant was smaller than 7.0 mm (p

Objectives The aim for the present study was to determine whether projection error of measuring Pauwels’ angle in young femur neck fracture could be eliminated by CT plane manipulation. Methods Clinical data of displaced femur neck fractures in young adults aged 20 to 64 years old (13 females and 17 males) were retrospectively analyzed. Their average age was 47.9 years (range: 22–64 years; SD: 11.3). Using modified measurement method for Pauwels’ angle using central line of the shaft as a guideline, the angle of a conventional coronal CT image was measured. CT images were imported into Mimics® software. The scanning plane was then reformatted parallel to the neck axis to eliminate projection error of injured limb. Measured angles were classified into three types (I 50°) and differences were analyzed. Results Average Pauwels’ angle was 52.9° (range: 28.6–68.3°; SD: 9.9; type II, 17 cases; type III, 13 cases) for conventional CT images and 68.7° (range: 29.8–91.2°; SD: 13.4; type II, 1 cases; type III, 29 cases) for reformatted CT images. Difference between these two measurements on average was 15.7° (range: 1.2–34.9°; SD: 7.3). Conclusions Reformatting CT scanning plane by manipulating the proximal fragment to be parallel with the neck axis of the distal neck-shaft fragment is a convenient and reliable technique for eliminating the projection error of measuring Pauwels’ angle in the femur neck fractures. Level of evidence IV, cohort study.

This study aimed to investigate the association between osteoporosis and comorbidity, which are very common in Korea, and develop a treatment strategy to improve bone health based on the findings of the Korean National Health and Nutritional Examination Surveys (KNHANES). This study was based on data obtained from 4060 subjects (1755 males, 2305 females) aged above 60 years in the KNHANES (2016&ndash, 2017). Well-trained medical staff performed the standard procedures and measured several variables including height, weight, and waist circumference. Interviews and laboratory tests were based on the diagnosis of hyperuricemia, dyslipidemia, type 2 diabetes mellitus (T2DM), osteoporosis, and depression. Comorbidities were defined as a self-reported physician diagnosis. The association of osteoporosis with depression and metabolic disease was assessed statistically using the complex sample analysis method of SPSS. The presence of osteoporosis, dyslipidemia, T2DM, hyperuricemia, obesity, abdominal obesity, and depression was 6.1 &plusmn, 0.5%, 15.2 &plusmn, 0.7%, 6.5 &plusmn, 0.4%, 13.4 &plusmn, 0.7%, 30.8 &plusmn, 0.8%, 19.4 &plusmn, 0.9%, 4.0 &plusmn, 0.2%, respectively. After adjusted by age, osteoporotic subjects were significance in the presence of abdominal obesity (p = 0.024, OR 0.80), hyperuricemia (p = 0.013, OR 0.68), dyslipidemia (p &lt, 0.001, OR 1.84), and depression (p &lt, 0.001, OR 2.56), respectively. Subgroup analyses showed dyslipidemia (female subjects, p &lt, 0.001, OR 1.04, male subjects, p = 0.94, OR 1.09) and depression (female subjects, p &lt, 0.001, OR 1.76, male subjects, p = 0.51, OR 0.62) were associated with osteoporotic female subjects but not in male subjects. The comorbidity of dyslipidemia and depression in female subjects was associated with osteoporosis and an odds ratio was 13.33 (95% CI: 8.58&ndash, 20.71) (p &lt, 0.001). The comorbidity of abdominal obesity (female subjects, p = 0.75, OR 0.97, male subjects, p = 0.94, OR 1.02) and hyperuricemia (female subjects, p = 0.27, OR 0.81, male subjects p = 0.07, OR 0.35) was not associated with osteoporosis in both Subgroup. The result of this study shows a strong dependency of comorbidity with dyslipidemia and depression in elderly women with osteoporosis. Therefore, efforts to improve dyslipidemia and depression might prevent compromised bone health.

Background: The management of lateral clavicle fractures is often challenging because of difficulties in identifying displacement patterns that indicate an unstable fracture. Hypothesis: The aim of this study was to evaluate displacement patterns through analysis using 3-dimensional (3D) rendering software for displaced lateral clavicle fractures. We hypothesized that most displaced lateral clavicle fractures would have posterior displacement and angulation as well as superior displacement of the medial fragment. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Radiographs of 37 displaced lateral clavicle fractures were imported into the 3D rendering software to reconstruct the fracture model. For the computational simulation of fracture reduction, the medial fragment was manipulated and returned into place using the software’s moving tools. Two corresponding points were marked between the medial and lateral fragments to measure 3D spatial location in the x-axis (shortening), y-axis (horizontal displacement), and z-axis (vertical displacement). The displacement angle on the cranial view was also measured based on the medial end of the clavicle. Results: There were 32 cases (86.5%) of superior displacement of the medial fragment (mean, 5.8 mm; range, –6.5 to 19.0 mm), 35 cases (94.6%) of posterior displacement of the medial fracture fragment (mean, 8.8 mm; range, –3.2 to 18.3 mm), and 23 cases (62.2%) of distraction of the fracture site (mean, 2.1 mm; range, –9.2 to 12.2 mm). All 37 patients revealed posterior angulation of the fracture site (mean, 8.9°; range, 2.2°-39.4°). Conclusion: Most displaced lateral clavicle fractures have posterior displacement and angulation as well as superior displacement of the medial fragment. Our results revealed that 3D evaluation of lateral clavicle fracture displacement patterns is useful for assessing fracture stability and making treatment decisions.

The purpose of this study was to identify the optimal position for a precontoured-locking plating (PHILOS®) of the proximal humerus in Asians in terms of conformity and to determine the prevalence of screw exits in the position of the highest conformity. Twenty adult humeri and 14 cadaveric shoulders were included in this study. After placing the precontoured plate in the well-fitted position on the humerus, we measured the distance between the upper margin of the plate and the tip of greater tuberosity (GT) (distance A) and the distance between the anterior margin of the plate and lateral border of the bicipital groove (BG) (distance B). The prevalence of K-wire exits was assessed. In the 14 cadaver shoulders, the mutual relation between the most inferior locking sleeve of the optimally positioned plate and the axillary nerve was evaluated to assess the potential for axillary nerve injury. The precontoured plate was well-fitted and remained in a relatively constant position in all specimens. Distance A was an average of 3.6 mm (range 1.4–5.5 mm), and distance B was an average of 2.5 mm (range 0–4.6 mm). The K wire closest to the BG pierced it in four cases (20 %), and most inferior K wires exited at an average distance of 3.8 mm (range 1.6–9.0 mm) from the inferior articular margin of the humeral head. Regarding involvement of the BG, articular width was the only significant variable in the logistic regression model, with an odds’ ratio of 0.610. The axillary nerve was located at an average vertical distance of 59.7 mm (range 51.8–66.9 mm) from the tip of the GT in a vertically neutral position. The results did not differ between the left and right sides (t = 0.326, p = 0.755). Although the axillary nerve was slightly inferior to the most inferior locking holes of the proximal humerus, it was located in the path of their locking sleeves on the deltoid muscle. The optimal position for the highest conformity led to ideal fixation of the proximal humerus and inferomedial support screw in Asians. However, the precontoured plate sometimes had screw exits that involved the BG, and articular width had a large impact on involvement of the BG. If locking sleeves for the most inferior holes were introduced on the deltoid muscle in a neutral position, there was high potential for injury to the axillary nerve in Koreans.

Background Transiliac-transsacral (TITS) screw fixation might be necessary in some cases involving the vertical shearing injuries with transforaminal fracture and bilateral posterior ring injuries. However, the possibility of S1 TITS screw should be preoperatively assessed because the pelvic ring injuries with sacral dysmorphism had the insufficient osseous corridors. Hypothesis AxWS2 may predict the possibility of TITS screw fixation and be used as the new indicator to discriminate the sacral dysmorphism. Materials and methods The conventional CT images of Eighty-two cadaveric pelvis imported into Mimics® software to reconstruct three-dimensional (3D) models. A 7.0-mm-sized screw was processed into a 3D model using a 3D-sensor at actual size and virtually implanted as S1 and S2 TITS screw using Mimics® software. The cortical violation around screw path was evaluated using 3D biplanar and conventional CT images. The osseous corridor widths around TITS screws were measured in the axial plane images and defined as AxWS1 and AxWS2, respectively. Results Despite no cortical violation in S2 of all models, cortical violation of S1 TITS screw was found in 20 models. Of them, 14 models (impossible models) were identified in the 3D biplanar images, and all 20 models (CT-violation models) were identified only in CT axial plane images. AxWS1 was Discussion By using AxWS2, The possibility of S1 TITS screw fixation could be predicted and safely placed without cortical violation, if AxWS2 was less than 13 mm. Considering the negative relationship with AxWS1, AxWS2 should be used as new indicator to predict safe S1 TITS screw fixation. Level of evidence III, controlled laboratory study.

Objectives The aim for the present study was to determine whether projection error of measuring Pauwels’ angle in young femur neck fracture could be eliminated by CT plane manipulation. Methods Clinical data of displaced femur neck fractures in young adults aged 20 to 64 years old (13 females and 17 males) were retrospectively analyzed. Their average age was 47.9 years (range, 22–64 years; SD, 11.3). Using modified measurement method for Pauwels’ angle using central line of the shaft as a guideline, the angle of a conventional coronal CT image was measured. CT images were imported into Mimics® software. The scanning plane was then reformatted parallel to the neck axis to eliminate projection error of injured limb. Measured angles were classified into three types (I 50°) and differences were analyzed. Results Average Pauwels’ angle was 52.9° (range, 28.6–68.3°; SD, 9.9; type II, 17 cases; type III, 13 cases) for conventional CT images and 68.7° (range, 29.8–91.2°; SD, 13.4; type II, 1 cases; type III, 29 cases) for reformatted CT images. Difference between these two measurements on average was 15.7° (range, 1.2–34.9°; SD, 7.3) Conclusions Reformatting CT scanning plane by manipulating the proximal fragment to be parallel with the neck axis of the distal neck-shaft fragment is a convenient and reliable technique for eliminating the projection error of measuring Pauwels’ angle in the femur neck fractures. Level of evidence IV, cohort study.

Introduction Ilio-sacral screw fixation has been used for sacral fractures and sacroiliac joint dislocations. However, it is associated with significant complications including screw loosening with backing-out and loss of reduction. Trans-sacral screw fixation is indicated for rigid fixation in specific circumstances including bilateral posterior ring injuries, osteoporotic bone, or to supplement other types of posterior ring fixation. Hypothesis The reformatting the CT scanning plane may distinguish sacral dysmorphism and predict the possibility of trans-sacral screw fixation by introducing the new indicator. Material and methods The CT data of 112 adult cadavers (61 males and 51 females) were imported into Mimics® software and a 7.0 mm-sized trans-sacral screw was virtually placed in the ideal position of S1. The osseous widths around screw in the axial images (AxWS1) were measured. By reformatting the CT scanning plane parallel to the superior endplate of S1, the AxWRS1 was measured and the height of elevated segment in the upper sacrum (elevated height) was assessed as a new preoperative indicator. Results Cortical violation around screw was detected in 26 models and was considered as sacral dysmorphism. The average AxWS1 was measured as 13.70 ± 2.76 mm in the non-dysmorphism group, and 5.81 ± 2.19 mm in the dysmorphism group, with statistical difference (p Discussion By reformatting the CT scanning plane, the osseous width around screw was widened, and the new preoperative indicator of elevated height could be introduced to predict the possibility of trans-sacral screw fixation into S1. If the elevated height exceeded 13 mm, the pelvis was assigned to sacral dysmorphism and thus, could not apply the trans-sacral screw fixation into S1. Level of evidence III, controlled laboratory study.

Purpose: The purpose of this study was to introduce practical landmarks for the successful use of the fluoroscopic inlet and outlet views to verify safe screw trajectories when placing percutaneous iliosacral (IS) screws. Materials and Methods: A total of 10 sacra (19 hemi-sacra) from cadavers without gross deformity or previous injury were included in this study. The upper boundaries and S1 were marked with 1 mm lead wire. The marked sacra were positioned on a radiolucent operative table similar to the operative supine position and projected into the pelvic inlet and outlet views and the true lateral view of the pelvis via an image intensifier. Using image editing software, fluoroscopic images were analyzed to identify the fluoroscopic landmarks and ideal entry points. Results: The posterior-superior corner of the lateral articular surface was constantly projected as a curve point in the pelvic inlet view, and the imaginary connecting line between two points did not violate the posterior walls of S1 in any of the sacra with a little space. Based on the curve points, screws had to be directed either straight or anteriorly (range: 18.3°-29.6°) on inlet view. On outlet view, the ideal screw trajectory was the imaginary oblique line from the height of the S1 foramen to the opposite upper corner of S1 (range: 15.5°-24.4°) and the sacral ala was not violated. Conclusion: For successful fluoroscopy, two simple landmarks could be utilized, the imaginary connecting line between the two curve points in the pelvic inlet view and the oblique screw trajectory toward the opposite corner of S1 in the pelvic outlet view, using the standard technique and irrespective of sacral dysplasia.

Background Open total extrusion of the talus without concomitant fracture is an extremely rare injury. We present 6-year follow-up data of a patient treated using a temporary spanning external fixator and less invasive single K-wire fixation. Case presentation A 55-year-old Asian man who had a totally extruded talus without fracture underwent immediate reimplantation surgery. A spanning external fixator with single antegrade K-wire fixation was applied to maintain the reimplanted talus. During 6 years of follow-up, he could walk without aids and could squat, corresponding to an American Orthopaedic Foot and Ankle Society score of 85. We found that the suspect lesion that was evident at 6 months after surgery had disappeared at 12 months postoperatively on the basis of sequential follow-up magnetic resonance imaging. There was no evidence of osteonecrosis of the dislocated talus at the final follow-up. Conclusions In patients with a totally extruded talus, a surgical strategy including immediate reimplantation of the talus and a temporary spanning fixator with single K-wire fixation might be useful to allow early mobilization around the ankle joint and to prevent additional damage of the foot without significant complications.

Background: As there is substantial variation in the classification and diagnosis of lateral clavicle fractures, proper management can be challenging. Although the Neer classification system modified by Craig has been widely used, no study has assessed its validity through inter- and intrarater agreement. Purpose: To determine the inter- and intrarater agreement of the modified Neer classification system and associated treatment choice for lateral clavicle fractures and to assess whether 3-dimensional computed tomography (3D CT) improves the level of agreement. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Nine experienced shoulder specialists and 9 orthopaedic fellows evaluated 52 patients with lateral clavicle fractures, completing fracture typing according to the modified Neer classification system and selecting a treatment choice for each case. Web-based assessment was performed using plain radiographs only, followed by the addition of 3D CT images 2 weeks later. This procedure was repeated 4 weeks later. Fleiss κ values were calculated to estimate the inter- and intrarater agreement. Results: Based on plain radiographs only, the inter- and intrarater agreement of the modified Neer classification system was regarded as fair (κ = 0.344) and moderate (κ = 0.496), respectively; the inter- and intrarater agreement of treatment choice was both regarded as moderate (κ = 0.465 and 0.555, respectively). Based on the plain radiographs and 3D CT images, the inter- and intrarater agreement of the classification system was regarded as fair (κ = 0.317) and moderate (κ = 0.508), respectively; the inter- and intrarater agreement of treatment choice was regarded as moderate (κ = 0.463) and substantial (κ = 0.623), respectively. There were no significant differences in the level of agreement between the plain radiographs only and plain radiographs plus 3D CT images for any κ values (all P > .05). Conclusion: The level of interrater agreement of the modified Neer classification system for lateral clavicle fractures was fair. Additional 3D CT did not improve the overall level of interrater or intrarater agreement of the modified Neer classification system or associated treatment choice. To eliminate a common source of disagreement among surgeons, a new classification system to focus on unclassifiable fracture types is needed.

Despite a high possibility of technique-related complications, ilio-sacral (IS) screw fixation is the mainstay of operative management in posterior pelvic ring injuries. We aimed to make IS screw trajectory with fully intraosseous path that was optimal and consistent, and confirm the possibility of transiliac–transsacral (TITS) screw fixation in Asian sacrum. Eighty-two cadaveric sacra (42 males and 40 females) were enrolled and underwent continuous 1.0-mm slice computed tomography (CT) scans. CT images were imported into Mimics® software to reconstruct three-dimensional model of the pelvis. To simulate IS screws, we inserted 7.0-mm-sized TITS cylinder for first (S1) and second (S2) sacral segment and 7.0-mm oblique cylinder for S1. TITS cylinder could not be inserted into S1 of 14 models (sacral variation models) but could be inserted into the S2 of all models. The actual length of virtual IS screws was measured, and anatomic features of safe zone (SZS2) including the area, horizontal distance (HDS2), and vertical distance (VDS2) were evaluated by the possibility of TITS screw fixation in the S1. When the oblique cylinder was directed toward the opposite upper corner of S1 at the level of the first foramen, there was no cortical violation regardless of sacral variation. The average length of TITS cylinder was 152.3 mm (range 127.9–178.2 mm) in S1 and 136.0 mm (range 97.8–164.1 mm) in S2, and for oblique cylinder it was 99.2 mm (range 82.4–132.2 mm). The average VDS2, HDS2, and the area of SZS2 were 15.5 mm (range 8.7–24.4 mm), 18.3 mm (range 12.7–26.6 mm), and 221.1 mm2 (range 91.1–386.7 mm2), respectively. The VDS2 and SZS2 of sacral variation were significantly higher than those of normal (both p = 0.001). Considering the high variability of the S1, it is better to direct the IS screw trajectory toward the opposite upper corner of the S1 at the level of first sacral foramen. If a TITS screw is needed, the transverse fixation for the S2 could be performed alternatively due to its sufficient osseous site even in Asian sacrum.

Objectives The purpose of this study was to predict the possibility of transverse iliosacral (TIS) screw fixation into the first sacral segment (S1) and introduce practical anatomical variables using conventional computed tomography (CT) scans. Materials and methods A total of 82 cadaveric sacra (42 males and 40 females) were used for continuous 1.0-mm slice CT scans, which were imported into Mimics® software to produce a three-dimensional pelvis model. The anterior height (BH) and superior width (BW) of the elevated sacral segment was measured, followed by verification of the safe zone (SZS1 and SZS2) in a true lateral view. Their vertical (VDS1 and VDS2) and horizontal (HDS1 and HDS2) distances were measured. VDS1 less than 7 mm was classified as impossible sacrum, since the transverse fixation of 7.0 mm-sized IS screw could not be done safely. Results Fourteen models (16.7%; six females, eight males) were assigned as the impossible sacrum. There was no statistical significance regarding gender (p = 0.626) and height (p = 0.419). The average values were as follows: BW, 31.4 mm (SD 2.9); BH, 16.7 mm (SD 6.8); VDS1, 13.4 mm (SD 6.1); HDS1, 22.5 mm (SD 4.5); SZS1, 239.5 mm2 (SD 137.1); VDS2, 15.5 mm (SD 3.0); HDS2, 18.3 mm (SD 2.9); and SZS2, 221.1 mm2 (SD 68.5). Logistic regression analysis identified BH (p = 0.001) and HDS1 (p = 0.02) as the only statistically significant variables to predict the possibility. Receiver operating characteristic curve analysis established a cut-off value for BH and HDS1 of impossible sacrum of 20.6 mm and 18.6 mm, respectively. Conclusion BH and HDS1 could be used to predict the possibility of TIS screw fixation. If the BH exceeds 20.6 mm or HDS1 is less than 18.6 mm, TIS screw fixation for S1 should not be undertaken because of narrowed SZ.

Purpose To determine the variability in the ideal entry point of cephalomedullary (CM) nail around the greater trochanter (GT) and the consequent conformity with the proximal femur by analyzing three-dimensional (3D) modeling and virtual implantation Materials and methods A total of 105 cadaveric femurs (50 males and 55 females) underwent continuous 1.0 mm slice computed tomography (CT) scans. CT images imported into Mimics ® software to reconstruct the 3D model of the proximal femur and medullary canal. PFNA-II ® was processed into a 3D model using a 3D-sensor at the actual size and optimally implanted in the proximal femur model using Mimics ® software. The ideal entry point, nail conformity with the proximal femur, and the relationship between the entry point and adjacent structures were assessed. Results The ideal entry point was located a mean of 2.38 mm (SD, 3.53 mm) medial to the tip of GT. No lateral cortex impingement of the proximal femur occurred in the coronal plane based on the recommended point. However, a disparity in the sagittal plane between the proximal shaft and nail curvature was found in 47 models (44.8%). Rotation and magnification of the 3D model exposed all nails above the surface of the medial side of the GT. The proximal nail end was contained entirely within bone and circumferential endosteal cortical contact was present at the nail-bone interface.

Benign bone tumor is a typical disease encountered in the field of orthopedic surgery. As one of the palliative treatments, invasive curettage of the lesion has been widely used.1) It is unavoidable, however, that palliative curettage is extremely invasive to soft tissue and the cortical bone in the lesions depending on the size of lesions. It is thus disadvantageous in that it may lead to various complications such as delayed union or bleeding, postoperative fracture due to a loss of the cortical bone and delayed wound healing and recovery at the operated sites.2-4) To reduce these undesirable side effects, Stricker5) first reported on endoscopic curettage in 1995. In 1999, Bonnel et al.6) reported that endoscopic curettage and bone graft were performed for simple bone cyst of the calcaneus. Thereafter, several authors have confirmed an excellent profile of efficacy for endoscopic curettage. In Korea, however, there is a dearth of studies evaluating the treatment. Most reports have been made regarding clinical cases (case studies). A comparative analysis of other types of bone tumor has been performed only in a limited scope. Based on the above background, we examined the clinical usefulness of endoscopic curettage, one of the non-invasive treatment modalities, and assessed which benign bone tumors could be effectively treated with endoscopic curettage.

As a treatment method of degenerative arthritis of knee, this study evaluated the clinical efficacy of the intra-articular injection of autologous bone marrow aspirates concentrate (BMAC) with adipose tissue.Between April 2011 and May 2012, 41 patients (75 knees) who were diagnosed as a degenerative knee arthritis and underwent the BMAC injection with adipose tissue were included in this study. Mean age was 60.7 years old (ranged 53-80). Kellgren-Lawrence grade was used for assessing radiologic degree of osteoarthritis; there were each 12, 24, 33, and 6 cases of grade I, II, III, and IV. At preoperative and postoperative 3, 6, and 12 months, pain score using visual analogue scale (VAS) and functional scales were used for evaluation.After the procedure, mean VAS score was decreased from 7.0 preoperatively to 4.1, 3.5, and 3.3 postoperatively 3, 6, and 12 months. And functional scores were also improved; International Knee Documentation Committee score (from 37.7 preoperatively to 59.3, 66.3, 69.3 postoperatively), SF-36 health score (from 31.5 to 43.5, 45.6, 47.7), knee and osteoarthritis outcome score (from 43.1 to 64.9, 68.5, 70.6), Lysholm Knee Questionnaire (from 37.3 to 65.4, 68.6, 71.0) were all increased after the procedure. When classified according to K-L grade, the improvement of VAS score in grade IV group was 8.2 preoperatively to 5.5, 5.3, and 5.7 postoperatively, which was significantly poorer than those of grade I-III groups. In the knee functional scales, similar pattern was checked.BMAC injection significantly improved both knee pain and functions in the patients with degenerative arthritis of knee. Also, the injection would be more effective in early to moderate phases.

The purpose of this study was to compare the outcomes of volar plating using two different implants for distal radius fractures. Fifty-two patients with AO type C fractures were placed in either of two groups: the AO LDRS group (26 patients) or the Acu-Loc group (26 patients). Radiological parameters including radial length, radial inclination, volar tilt, and intra-articular step-off were significantly improved after surgery. The mean Mayo Wrist Performance Score was 84.6 in the AO LDRS group and 81.1 in the Acu-Loc group. The mean Subjective Wrist Value was 86.7% in the AO LDRS group and 86.3% in the Acu-Loc group. There were no significant differences between the two groups with respect to both radiological and clinical outcomes at the final follow-up evaluation. Volar fixed-angle plating for unstable distal radius fractures had satisfactory radiological and clinical outcomes. The difference of implant design did not influence overall final outcomes.