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We assessed the sex difference in the volume and surface area of the bone using three-dimensional bone models generated from computer tomography images of axial skeletal elements from 110 Korean cadavers. The volume and surface area of all bones were significantly different between females and males. The accuracy of sex determination ranged from 55.6%-93.7% in univariate discriminant function analysis, with the second thoracic vertebra showing the highest accuracy. In discriminant analysis using paired bone combinations, 22 combinations of bone volume and surface area yielded90% accuracy in sex determination. The highest accuracy in the stepwise analysis was 94.7% when using the surface area of the ribs, sternum, and vertebrae for determining sex. This result shows a higher or similar accuracy than previous metric and non-metric studies using the axial skeleton, however, it shows lower accuracy than previous study which used volume and surface area of the appendicular skeleton. Nevertheless, this method might have advantage that is possible to determine sex quickly due to base on the computation with medical images.

Kinematically aligned total knee arthroplasty (KA TKA) targets restoration of patient-specific alignment and soft tissue laxity. However, whether KA TKA reproduces native soft tissue strain remains unclear. This cadaveric study tested the hypothesis that KA TKA would better restore the quantitative strain and strain distribution of medial collateral ligament (MCL) to the native healthy knee compared to mechanically aligned (MA) TKA. Twenty-four fresh-frozen cadaver knees (12 pairs) were mounted on a customized knee squatting simulator to measure MCL strain during flexion. For each pair, one knee was assigned to KA TKA and the other to MA TKA. During KA TKA, the amount of femur and tibia resected was equivalent to implant thickness without MCL release using the calipered measuring technique. MA TKA was performed using conventional measured resection techniques. MCL strain was measured using a video extensometer (Mercury® RT RealTime tracking system, Sobriety s.r.o, Czech Republic). MCL strain and strain distribution during knee flexion were measured, and the measurements compared between native and post-TKA conditions. Mean and peak MCL strain were similar between KA TKA and native knees at all flexion angles (p > 0.1 at all flexion angles) while mean strain at all flexion angles and peak strain at ≥ 60o of MA TKA were approximately twice those of the native knees (p

To elucidate the effect of medial meniscus posterior root (MMPR) repair during opening-wedge high tibial osteotomy (OWHTO) in terms of contact pressure (CP) and contact area (CA).Nine fresh-frozen human cadaveric knee specimens were included. Each specimen was tested under 9 conditions comprising 3 different degrees of correction during OWHTO (neutral, 5° of valgus, and 10° of valgus) and 3 different types of MMPR conditions (intact, torn, and repaired). The prepared specimens were attached to a customized tibiofemoral jig in a fully extended state. The CP and CA generated by a tibiofemoral axial load of 650 N was recorded using the Tekscan sensor's pressure mapping software. Statistical analysis was performed using a repeated measures analysis of variance.The increased CP and decreased CA in torn MMPR was decreased and increased, respectively, to the intact MMPR after repairing, irrespective of whether OWHTO was performed. The mean CP at a correction angle of 5° of valgus was 0.4067 ± 0.0768 MPa for intact MMPR, which increased to 0.7340 ± 0.1593 MPa for the torn MMPR and decreased to 0.3614 ± 0.0639 MPa for the repaired MMPR. In addition, the proportion of decrease in CP and increase in CA after MMPR repair was constant, compared with the torn MMPR, irrespective of the degree of correction during OWHTO.MMPR repair decreases CP and increases CA, irrespective of whether OWHTO is performed. The biomechanical advantage of repairing torn MMPR is maintained, regardless of the degree of correction during OWHTO.Both OWHTO and MMPR repair are known to protect the medial compartment of the knee. However, there are concerns in performing 2 procedures simultaneously. Results of our study showed that concurrent repair of the MMPR during OWHTO is useful for protecting the medial compartment of the knee with respect to tibiofemoral contact biomechanics.

Objectives To investigate the effect of screw length, lateral hinge fracture, and gap filling on stability after medial opening wedge high tibial osteotomy (MOW HTO) using a locking plate. Methods Forty tibiae from fresh-frozen cadavers were randomly allocated into five groups. Group A was bicortically fixated, while Group B and Group C were unicortically fixated: 90% and 55% of drilled tunnel length, respectively. Group D was fixated using 90% length screws with a fractured lateral hinge. Group E was fixated using 90% length screws with gap filling using a bone substitute. Operated tibiae were tested under axial compressive load using a material testing machine. The medial gap changes under the serial axial load of 100–600 N and ultimate failure load were measured. Results Group D showed the biggest medial gap change and lowest failure load, while Group E presented the smallest gap change and highest failure load. The medial gap changes tended to increase with shorter screw length, but the difference was not significant between Groups A, B, and C. Group C and Group D showed greater medial gap change and lower failure load compared with Group E, while not differing from Group A and Group B. Conclusions Unicortical fixation in proximal screw holes of a locking plate was not inferior to bicortical fixation regarding axial stability in MOW HTO, although proximal screws that are too short should be avoided. Lateral hinge fracture decreased, while gap filling with bone substitute increased axial stability.

Objective Posterior subaxial cervical screw fixation is commonly performed using the cervical pedicle screws (CPS) and lateral mass screws (LMS); however, their compatibility is low. Modified lateral mass screws (mLMS, also called paravertebral foramen screw) fixation was introduced as a salvage technique for LMS fixation and has features of both LMS and CPS techniques. In the present study, the use of mLMS as an alternative to CPS was analyzed based on clinical results. Methods Seventy-eight screws (38 CPSs and 40 mLMSs) were inserted into 12 patients. The misplacement of the screws was evaluated by computed tomography (CT). The failure of instrumentation and instability were evaluated using plain radiographs. Results The total number of CPS misplacements was 3 (10.5%); however, neurologic complications were not observed. mLMSs were used in the middle segments of the fusion in 10 patients and 2 patients had mLMS fixation for single-level fusion. An additional bridging implant was not required for connecting both CPSs and mLMSs. Instability was not observed during the observation period (4–51 months). Complete fusion was seen in 10 patients. Conclusions The alternative mLMS fixation can decrease the risk of screw misplacement compared with CPS fixation alone and achieves adequate stability leading to fusion.

We analyzed tunnel length, graft bending angle, and stress of the graft according to tunnel entry position and aspect ratio (ASR: ratio of anteroposterior depth to mediolateral width) of the articular surface for the distal femur during single-bundle outside-in anterior cruciate ligament reconstruction (ACLR) surgery. We performed multiflexible body dynamic analyses with four ASR (98, 105, 111, and 117%) knee models. The various ASRs were associated with approximately 1 mm changes in tunnel length. The graft bending angle increased when the entry point was far from the lateral epicondyle and was larger when the ASR was smaller. The graft was at maximum stress, 117% ASR, when the tunnel entry point was near the lateral epicondyle. The maximum stress value at a 5 mm distance from the lateral epicondyle was 3.5 times higher than the 15 mm entry position, and the cases set to 111% and 105% ASR showed 1.9 times higher stress values when at a 5 mm distance compared with a 15 mm distance. In the case set at 98% ASR, the low-stress value showed a without-distance difference from the lateral epicondyle. Our results suggest that there is no relationship between the ASR and femoral tunnel length. A smaller ASR causes a higher graft bending angle, and a larger ASR causes greater stress in the graft.

Computer-assisted orthopedic surgery and patient-specific instruments are widely used in orthopedic fields that utilize contralateral side bone data as a template to restore the affected side bone. The essential precondition for these techniques is that the left and right bone features are similar. Although proximal humerus fracture accounts for 4% to 8% of all fractures, the bilateral asymmetry of the proximal humerus is not fully understood. The aim of this study is to investigate anthropometric differences of the bilateral proximal humerus. One hundred one pairs of Korean humerus CT data from 51 females and 50 males were selected for this research. To investigate bilateral shape differences, we divided the proximal humerus into three regions and the proximal humerus further into five sections in each region. The distance from the centroid to the cortical outline at every 10 degrees was measured in each section. Differences were detected in all regions of the left and right proximal humerus, however, males had a larger number of significant differences than females. Large bilateral differences were measured in the greater tubercle. Nevertheless, using contralateral data as a template for repairing an affected proximal humerus might be possible.

Four pairs of fresh-frozen cadaver knees (eight knees, four male knees) with a mean age of 72 ± 7 years were used for tests involving a customized simulator capable of controlling quadriceps loading conditions. The muscle force distribution of the quadriceps for the normal loading condition was applied on the basis of muscle cross-sectional area data, as previously reported (VM: 31 N, RF/VI: 49 N, VL: 45 N). To simulate vastus medialis (VM) impairment, we set the muscle force for VM in the muscle force distribution of the quadriceps at zero (VM: 0 N, VL: 45 N). The joint reaction forces and moments on knee joints that underwent total knee arthroplasty (TKA) did not differ significantly according to VM impairment status for all flexion angles (p &gt, 0.05). Nevertheless, the vectors of internal–external moments mostly showed a tendency for alteration from external to internal due to VM impairment. This tendency was evident in 9 cases in 12 total test pairs (with and without VM impairment). Furthermore, the vectors of the anterior–posterior reaction forces mostly showed a tendency to increase anteriorly due to VM impairment. This tendency was also evident in 9 cases in 12 total test pairs (with and without VM impairment). These results indicate that posterior dislocation of the tibia may be induced if VM impairment occurs after TKA. In conclusion, VM impairment in knee joints undergoing TKA may contribute to posterior dislocation of the tibia by a paradoxical roll-back with enhancements of the anterior joint reaction force and external moment during knee-joint flexion. Our findings may be valuable for understanding the mechanism of potential instability and malfunction due to VM impairment in knee joints after TKA, and may help to optimize clinical/rehabilitation training plans to improve the prognosis (stability and function) of knee joints undergoing TKA.

A metatarsal osteotomy is known to have the effect of reduction of the sesamoid. However, the reduction of the sesamoid is not always completed by a metatarsal osteotomy alone. The purpose of this cadaver study was to show that the improved technique of a modified Akin proximal phalanx osteotomy (MPO) could be helpful for the reduction of the sesamoids in hallux valgus surgery. Ten feet of cadavers were used; the cadavers had hallux valgus on both feet. The first trial of two feet underwent only the MPO. The other eight feet underwent a proximal metatarsal chevron osteotomy and MPO simultaneously. The hallux valgus angle, intermetatarsal angle, Hardy’s grade, and Smith’s grade were measured. To predict possible complications, cadavers were dissected after surgery. In the feet that underwent an MPO only, the hallux valgus angle and sesamoid position were improved. In the feet that underwent an MPO and metatarsal osteotomy, the hallux valgus deformity was completely corrected, and the sesamoid position was improved. Overall, the hallux valgus angle and intermetatarsal angle improved from 30.6 to 8.4 degrees and from 11.2 to 4.1 degrees, respectively. The sesamoid position was reduced from 5.3 to 2.5 (Hardy) and from 1.7 to 0.7 (Smith). The MPO combined with the metatarsal osteotomy were helpful for reducing the sesamoids compared to the metatarsal osteotomy only.

Ulnolunate abutment has been thought to be aggravated by pronation because of an increase in ulnar variance. We hypothesized that the ulnolunate distance might be greater in pronation because the ulnar head is dorsally translated. Twenty-one three-dimensional reconstructions of computed tomographic scans of wrists taken in supination and pronation were investigated. The ulnolunate distance was measured in each position, and the change in ulnolunate distance from supination to pronation was calculated. The changes in ulnar variance from supination to pronation and the amount of translation of the ulnar head were measured directly by superimposing three-dimensional reconstructions. The mean ulnolunate distance in pronation was significantly greater than in supination. There was no significant correlation between the changes in ulnolunate distance and in the ulnar variance. The change in ulnolunate distance had a significant positive linear relationship with the amount of translation of the ulnar head. The change in ulnolunate distance during forearm rotation is determined by the amount of translation of the ulnar head rather than by change in ulnar variance.Level of evidence: IV

Preoperative skin sterilization, disinfection, and fracture reduction are all necessary for surgeries of the fractured lower extremity. This procedure requires several medical personnel, even though its tasks are relatively simple. Therefore, development of an assistant device for the preoperative disinfection and the simple fracture reduction is required as an alternative. To obtain the design specifications of the equipment, we evaluated lifting and traction forces using the lower extremities of Korean fresh cadavers. The lifting force was measured when each leg was lifted from the table using 39 Korean fresh cadavers. The same method was applied to measure the traction force on a femoral fracture model using 22 Korean fresh cadavers. The mean lifting force was 36.8 ± 11.8 N, and the mean traction force was 116.8 ± 37.9 N. Regression analysis yielded the following equations: lifting force = 0.6724*(body weight) - 0.8068, R2 = 0.71; traction force = 1.6880*(body weight) + 18.1495, R2 = 0.57. This study determined the lifting and traction forces, not just the body segment weights. These results will be helpful for developing medical assistant devices.

To observe changes of spinopelvic parameters and the presence of pelvic incidence (PI) variation in different positions, and the accuracy of PI compared with CT scan. Patients with standing whole-spine radiograph, CT scan of the pelvic bone, and MRI of the lumbar spine done within a few days were included. The pelvic [pelvic tilt (PT), sacral slope (SS), and PI] and spinal [lumbar lordosis (LL)] parameters were measured by two different observers. The PIs from radiograph were significantly greater than those from CT in both observers. By adopting the upper limit of the confidence interval and the agreement of two observers on grouping, patients were categorized into two subgroups (SG1, with less PI change; SG2, with higher PI change). The PT and LL values decreased, whereas SS increased significantly from standing to supine positions in SG1. Significantly decreased PT and PI from standing to supine were observed in SG2. All pelvic parameters and the sagittal vertical axis on radiograph, and the LL amount on MRI were significantly greater in SG2 than in SG1. Majority of patients demonstrated alignment changes of unchanged PI with decreased PT and LL, and increased SS from standing to supine; however, decreased PT and PI and fixed SS and LL were also demonstrated. Patients with higher PI change have high values in three pelvic parameters and sagittal vertical axis, and fixed LL.

Background This study evaluated the technical adequacy of trans-articular sacroiliac joint (SIJ) fusion using three screws for non-traumatic SIJ pain, considering different grades of sacral dysplasia. Methods Cadaveric CT data of unilateral sacropelvic complexes for 72 individuals (53.4 ± 8.4 years) were selected. A 3D model was reformatted into the plain lateral radiograph to mark the articular surface of the SIJ. Subjects were classified into dysplastic (DYS) and non-dysplastic sacrum (NDS) groups. Proximal (PS), middle (MS), and distal screws (DS) with 10-mm diameter were virtually introduced to the iliac bone and the SIJ on the lateral image with a 5-mm safety margin. On a corresponding axial image, each screw was advanced vertically to the sagittal plane with the same safety margin. The entry points for each screw to the endplate of S1 (S2) and to the corresponding anterior sacral margin on the lateral image were measured, along with the maximal screw lengths on the axial image. Whether each screw passed through the SIJ was determined. Different types of sacral dysplasia and screws were compared statistically. Results Thirty-eight (26.4%) cases were DYS, and 106 (73.6%) were NDS. The entry points of all screws were significantly more distal in DYS than in NDS groups. The PS and MS screw lengths differed significantly between the 2 groups. Incidences of short sacral fixation (

Many researchers have studied the structures of the anterolateral part of the knee. Several researchers have investigated the existence of the anterolateral ligament (ALL) and its frequency has been inconsistently reported. Therefore, we assessed whether the ALL is the anatomical true ligament and studied the morphological variations of this structure. Sixty-four Korean adult cadavers (120 knees, mean age: 79.1 years) were used for this study. The lateral part of the knee joint was carefully dissected with internal rotation of the tibia. We checked the existence and morphological features and measured the dimensions (length, width, and thickness) of the ALL. The ALL was clearly distinguished from the capsulo-osseous layer of the iliotibial tract and runs obliquely from the lateral femoral epicondyle to the tibial plateau. The ALL was found in 42.5% of the samples, and 15 cadavers had ALLs in both knees. There was no prevalence difference between females and males. Most of the anterior border of the ALL was blended with the knee capsule. Therefore, we concluded that this structure is a local thickening of the capsule in the anterolateral region of the knee, where it possibly developed against some external physical stress. Therefore, the ALLs in this present study can be defined as a capsular ligament of the knee and, as per the nomenclature of the capsular ligament, can be also called the ‘anterolateral (capsular) ligament’.

The purpose of this study was to measure the volar cortical angles of the commercially available volar locking plates and evaluate how well they fit the distal radius. We measured the volar cortical angles of the radial and intermediate columns of eight volar locking plates and compared them with the volar cortical angles of 90 cadaver distal radii. The mean radial and intermediate column volar cortical angles of the wider plates were significantly larger than those of narrower plates. The mean radial and intermediate column volar cortical angles were significantly larger in wider radii than narrower radii. The width of the distal radius did not correlate well with the mean volar cortical angles of the radial and intermediate columns. Level of Evidence: IV

The aim of this study was to clarify the morphological patterns and proportions of the components of the nasal septum. Anatomical examinations were performed on 70 nasal septums of embalmed Korean adult cadavers. The septal deviation was checked before cutting the nasal cavity midsagittally with the aid of a laryngoscope. The shape of each component of the nasal septum was identified, and photographs were taken from a midline sagittal view. A line was drawn on each photograph between the septal components, and then the area of each septal component was measured using software. The mean area proportions of the septal cartilage (SC), the perpendicular plate of the ethmoid bone (PPE), the vomer, and the nasal crest of the maxilla relative to the total area of the nasal septum were 25.6%, 43.0%, 25.8%, and 5.6%, respectively. The morphology of the nasal septum was classified into 3 main patterns according to the proportion of each septal component. The proportions of the SC, the PPE, the vomer, and the nasal crest of the maxilla were similar to the mean values of the present study in 45.7%. The proportions of the SC, the PPE, and the vomer were similar to each other (with a difference of

Body mass (BM) estimation could facilitate the interpretation of skeletal materials in terms of the individual's body size and physique in forensic anthropology. However, few metric studies have tried to estimate BM by focusing on prominent biomechanical properties of the calcaneus. The purpose of this study was to prepare best-fit models for estimating BM from the 3D human calcaneus by two major linear regression analysis (the heuristic statistical and all-possible-regressions techniques) and validate the models through predicted residual sum of squares (PRESS) statistics. A metric analysis was conducted based on 70 human calcaneus samples (29 males and 41 females) taken from 3D models in the Digital Korean Database and 10 variables were measured for each sample. Three best-fit models were postulated by F-statistics, Mallows' Cp, and Akaike information criterion (AIC) and Bayes information criterion (BIC) for each available candidate models. Finally, the most accurate regression model yields lowest %SEE and 0.843 of R(2). Through the application of leave-one-out cross validation, the predictive power was indicated a high level of validation accuracy. This study also confirms that the equations for estimating BM using 3D models of human calcaneus will be helpful to establish identification in forensic cases with consistent reliability.

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint's contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p

Background and Study Aim Cortical screws were proposed as an alternative to the traditional pedicle screws. Diverse experimental results support the biomechanical superiority of cortical screws compared to pedicle screws. Laminectomy is often part of multilevel lumbar surgeries. Laminectomy might weaken the medial bony edge at the entry of the divergently oriented screw and, thereby, the screw purchase. This study investigated the biomechanical strength of lumbar cortical screw after laminectomy. Objective To compare the fixation strength of cortical screws and traditional pedicle screws after lumbar laminectomy. Material and Methods A total of 120 pedicles from 60 lumbar vertebrae of 12 cadavers (8 men, 4 women) were assessed. The mean age of the cadavers was 73.4 ± 6.2 years (range: 62–82 years). Using a posterior midline approach, we inserted the traditional pedicle screws into one and the cortical screws into the other side of each vertebra. Laminectomy was performed after screw insertion. Vertical pullout strength and toggle strength testing were performed to compare the fixation strength between the two sides. Results After laminectomy, the pullout strength of the cortical screws was 718.92 ± 340.76 N, and that of the pedicle screws was 625.78 ± 287.10 N (p = 0.183). The toggle strength of the cortical screws was 544.83 ± 329.97 N; that of the pedicle screws was 613.17 ± 311.70 N (p = 0.145). No significant difference was found in biomechanical strength between the two types of screws. Conclusion Despite laminectomy, lumbar cortical screws offers comparable pullout and toggle biomechanical strength as traditional pedicle screws.

Cadaver study and clinical application; a pilot study.To minimize muscle dissection and enhance accuracy of cervical pedicle screw (CPS) placement by using a percutaneous cannula system.Many studies have reported that the most frequent misplacement of CPSs is breach of the lateral wall; thus, an easy technique for securing medial convergence is required. We developed a percutaneous cannula system for this purpose and report the results of a cadaver study and its clinical application.A cadaver study was conducted to confirm the possibility of this percutaneous technique in 5 specimens (50 CPSs, C3-C7). Then, the technique was applied in 8 patients (40 CPSs, C3-C7). The surgical technique was a hybrid of miniopen surgery and the use of percutaneous cannula system under lateral fluoroscopic guidance. Entry holes were made in the open field and a cannula was used for tapping and insertion of CPSs. A stiff pedicle probe through the cannula was used to locate the pedicle in the lateral mass.In the cadaver study, there were 12 (24%) misplacements among 50 CPSs used. The hybrid technique was applied clinically in 4 traumatic, 2 degenerative, and 2 failed back surgery lesions. Thirty CPSs were inserted using the percutaneous cannula system and 10 were inserted using a cannula as a retractor. Misplacement occurred in 6.7% (n = 2) and 20% (n = 2) pedicles, respectively, and there were no symptomatic complications (total incidence, 10%). An additional incision for the cannula system can be made for 2-level CPS insertions.Use of the percutaneous cannula system facilitated a secure convergence angle for CPS insertion without extending muscle dissection or shifting cervical alignment because of muscle retraction. Moreover, this system can be used for CPS insertion in bull-necked patients.3.

We investigated the quantitative effect and risk factors for over-release during multiple needle puncturing (MNP) for medial gap balancing in varus total knee arthroplasty (TKA). Of the ten pairs of cadaveric knees, one knee from each pair was randomly assigned to undergo MNP in extension (E group), while the other knee underwent MNP in flexion (F group). The increased extension and 90° flexion gaps after every five needle punctures were measured until over-release occurred. The extension gap (4mm) and the 90° flexion gap (6mm) gradually increased in both groups. The 90° flexion gaps increased more selectively than did the extension gaps. MNP in the flexed knee, a narrow MCL, and severe osteoarthritis were associated with a smaller number of MNPs required to over-release.

This study aimed to report the mechanical strength and characteristics of the lateral mass and pedicle considering BMD for the safe insertion of pedicle screws in the subaxial cervical level. We evaluated BMD and Hounsfield unit (HU) values of cortical bones at the lateral mass and pedicle of C3-7 from CT images in 99 patients. Patients were divided into three groups (Group A, T-score ≥-1; Group B, −2.5

A new device (T-anchor) was developed for ACL reconstruction and is implanted via the outside-in technique using hamstring grafts. The purpose of this study was to compare the T-anchor with the EndoButton Direct.This study was conducted on 30 cadaveric knees (15 matched pairs). There were two groups of 15 each in the T-anchor and EndoButton Direct groups. After the harvest of grafts, fixation site profile and graft length were measured by loading the grafts onto both devices. They were then tested on a universal testing machine to assess elongation after cyclic loading, load to failure, ultimate load, and mode of failure.The fixation site profile was lower in the T-anchor group than in the EndoButton Direct group (2.3±0.4mm vs. 4.7±1.0mm, P0.001). The length of the graft-device complex of the T-anchor specimens was longer than that of the EndoButton Direct specimens (125.0±8.9mm vs. 115.0±8.7mm, P0.001). The mean cyclic elongation was lower for the T-anchor group when compared with the EndoButton Direct group (2.4±0.6mm vs. 3.9±2.6mm, P=0.015). There was no statistically significant difference in ultimate load and load to failure between the T-anchor and EndoButton Direct groups. For mode of failure, the T-anchor fared better (P=0.013) with all failures attributed to specimens.In this cadaveric study, the new device, T-anchor, performed better than the EndoButton Direct with respect to the above-mentioned study parameters except for ultimate load and load to failure.

The shape of the anterior surface of the distal radius is important for designing a distal radius plate for wrist fracture surgery. The aim of this study was to describe the shape of the anterior surface of the distal radius and to compare the results between female and male. We used 90 sides from three-dimensional radial models based on computer tomography images from Korean adult cadavers for this study. The anterior surface was measured in two dimensions in the coronal view, and we sectioned the anterior surface of the models to obtain intermediate and radial sections to measure the curved shape of the anterior surface in sagittal view. Several parameters were statistically different between females and males; however, there were no differences between the right and left sides for any parameters. The width of the anterior surface in the coronal view was larger in males than females, and the curved part of the anterior surface of the males was longer and more concave than that of females. In both the female and male specimens, the intermediate section was longer and more concave than the radial section. Our results are useful for anthropological studies and for designing distal radial plates.

A thorough understanding of the morphology of the lamina of the second cervical vertebra (C2) is important for safe C2 translaminar screw placement. Although anatomical characteristics of the C2 lamina have been widely documented, individual differences in morphology have not been addressed. The aim of this study was to morphometrically analyze the cross-sectional shape of the C2 lamina and classify the shape to describe individual differences. Morphometric analysis was conducted on 145 three-dimensional C2 models based on computerized tomography images from Korean adult cadavers. Several parameters were measured on a cross-section image of the lamina model. Based on numerical criteria, all of the C2 lamina’s cross-sectional shapes could be categorized into three distinctive morphological types: pyriform, ellipse, and obpyriform shapes. We confirmed that most Koreans can accommodate C2 translaminar screw placement with a lower limit of the 95% confidence interval of thickness measured at 6.26 mm. Morphometric analysis suggested that the obpyriform-shaped lamina (4.48%) is likely to require screw trajectory adjustment to avoid cortical breakout of the screw. Our results will enhance current anatomical understanding of the C2 lamina and thus facilitate safer C2 translaminar screw placement.

Despite the documented clinical efficacy of the pie-crusting technique for medial collateral ligament (MCL) release in varus total knee arthroplasty, its quantitative effects on medial gaps and safety remain unclear. This study was undertaken to determine the efficacy (quantitative effect and consistency of the number of punctures) and the safety (frequency of early over-release) of the pie-crusting technique for MCL release.From ten pairs of cadaveric knees, one knee from each pair was randomly assigned to undergo pie crusting in extension (group E) or in flexion (group F). Pie crusting was performed in the superficial MCL using a blade until over-release occurred. After every puncture, the incremental medial gap increase was recorded, and the number of punctures required for 2- or 4-mm gap increases was assessed.In group E, the extension gap increased from 0.8 to 5.0 mm and the flexion gap increased from 0.8 to 3.0 mm. In group F, the extension gap increased from 1.0 to 3.0 mm and the flexion gap increased from 2.6 to 6.0 mm. However, the gap increments were inconsistent with those that followed the preceding blade punctures, and the number of punctures required to increase the gaps by 2 or 4 mm was variable. The number of punctures leading to over-release in group E and group F was 6 ± 1 and 3 ± 1 punctures, respectively. Overall, 70% of over-release occurred earlier than the average number of punctures leading to over-release.Pie crusting led to unpredictable gap increments and to frequent early over-release. Surgeons should decide carefully before using the pie-crusting technique for MCL release and should be cautious of performing throughout the procedure, especially when performing in a flexed knee.Therapeutic study, Level I.

Background Anatomic footprint restoration of anterior cruciate ligament (ACL) is recommended during reconstruction surgery. The purpose of this study was to compare and analyze the femoral and tibial tunnel positions of transtibial single bundle (SB) and transportal double bundle (DB) ACL reconstruction using three-dimensional computed tomography (3D-CT). Methods In this study, 26 patients who underwent transtibial SB ACL reconstruction and 27 patients with transportal DB ACL reconstruction using hamstring autograft. 3D-CTs were taken within 1 week after the operation. The obtained digital images were then imported into the commercial package Geomagic Studio v10.0. The femoral tunnel positions were evaluated using the quadrant method. The mean, standard deviation, standard error, minimum, maximum, and 95% confidence interval values were determined for each measurement. Results The femoral tunnel for the SB technique was located 35.07% ± 5.33% in depth and 16.62% ± 4.99% in height. The anteromedial (AM) and posterolateral (PL) tunnel of DB technique was located 30.48% ± 5.02% in depth, 17.12% ± 5.84% in height and 34.76% ± 5.87% in depth, 45.55% ± 6.88% in height, respectively. The tibial tunnel with the SB technique was located 45.43% ± 4.81% from the anterior margin and 47.62% ± 2.51% from the medial tibial articular margin. The AM and PL tunnel of the DB technique was located 33.76% ± 7.83% from the anterior margin, 45.56% ± 2.71% from the medial tibial articular margin and 53.19% ± 3.74% from the anterior margin, 46.00% ± 2.48% from the medial tibial articular margin, respectively. The tibial tunnel position with the transtibial SB technique was located between the AM and PL tunnel positions formed with the transportal DB technique. Conclusions Using the 3D-CT measuring method, the location of the tibia tunnel was between the AM and PL footprints, but the center of the femoral tunnel was at more shallow position from the AM bundle footprint when ACL reconstruction was performed by the transtibial SB technique.

Thus far, anatomical studies have reported data on the cervical pedicle, with the focus remaining on the pedicle itself. It was necessary to obtain more comprehensive data about the relationships between the lateral mass, pedicle, and transverse foramen for cervical pedicle screwing (CPS) and paravertebral foramen screwing (PVFS), a new technique. The purpose of this study was to describe the relationships between the lateral mass, pedicle, and transverse foramen. This study analyzed computed tomography images from 77 patients (42 female, 35 male; mean age: 63.95 years). The anatomical pedicle transverse angle (PTA) and linear parameters of the lateral mass were measured, and the relationship between the calculated angles and the anatomical PTA was investigated. θp was defined as the convergence angle from the posterolateral edge of the lateral mass to the pedicle, and θc was defined as the convergence angle from the posterolateral edge of the lateral mass to the anterolateral corner of the vertebral foramen. The thickness of the cortical bone of the medial wall of the lateral mass (cT) and the medial (mT) and lateral (lT) walls of the pedicle at C3–7 were also measured. The PTA was similar to θp and θc at C3–6, but different at C7. In all cases, the transverse foramen was located more anterior to the posterior wall of the cervical body at C3–6, but not at C7. mT and cT were significantly thicker than lT at all levels. Lateral fluoroscopic images show that when the probe is inserted along θc, it meets the counter corner of the lateral mass at C3–6 without invasion of the transverse foramen if it does not cross the posterior wall of the vertebral body. This can be significant when performing CPS and PVFS.

The aim of this study was to clarify the morphological characteristics of the intermuscular aponeurosis between the flexor carpi ulnaris (FCU) and flexor digitorum superficialis (FDS; IMAS), and that between the FCU and flexor digitorum profundus (FDP; IMAP), and their topographic relationships with the ulnar nerve. Fifty limbs of 38 adult cadavers were studied. The IMAS extended along the deep surface of the FCU adjoining the FDS, having the appearance of a ladder, giving off “steps” that decreased in width from superficial to deep around the middle of the forearm. Its proximal part divided into two bands connected by a thin membrane, and was attached to the medial epicondyle and the tubercle (the most medial prominent part of the coronoid process of the ulna), respectively. The IMAP extended deep between the FCU and FDP from the antebrachial fascia, and its distal end was located on the posterior border of the FCU. The IMAP became broader toward its proximal part, and its proximal end was attached anterior and posterior to the tubercle and the olecranon, respectively. The ulnar nerve passed posterior to the medial epicondyle and then medial to the tubercle, and was crossed by the deep border of the IMAS at 58.3 ± 14.1 mm below the medial epicondyle. The deep border of the IMAS and aberrant tendinous structure passing across the ulnar nerve, or the parts of the IMAS and IMAP passing posterior to the ulnar nerve are potential causes of ulnar nerve compression.

Knee joint implants developed by western companies have been imported to Korea and used for Korean patients. However, many clinical problems occur in knee joints of Korean patients after total knee joint replacement owing to the geometric mismatch between the western implants and Korean knee joint structures. To solve these problems, a method to determine the representative dimension parameter values of Korean knee joints is introduced to aid in the design of knee joint implants appropriate for Korean patients. Measurements of the dimension parameters of 88 male Korean knee joint subjects were carried out. The distribution of the subjects versus each measured parameter value was investigated. The measured dimension parameter values of each parameter were grouped by suitable intervals called the “size group,” and average values of the size groups were calculated. The knee joint subjects were grouped as the “patient group” based on “size group numbers” of each parameter. From the iterative calculations to decrease the errors between the average dimension parameter values of each “patient group” and the dimension parameter values of the subjects, the average dimension parameter values that give less than the error criterion were determined to be the representative dimension parameter values for designing knee joint implants for Korean patients.

The Korean spine geometry and property data for researchers were made by KISTI and Catholic Institute for Applied Anatomy. We took whole spine CT, X-Ray, BMD scan for making high resolution cross-sectional spine images using more 20 donated cadavers(60 - 80 years). Then we constructed 3-dimensional volume model using serial CT images by Mimics software. The major morphometric parameters of vertebrae were measured. Mechanical motion and property data were obtained by the same cadavers using the DEXA for BMD and the spine simulator. The Korean spine geometry and property data could be used for research and development of medical device.

To investigate the effects of meniscectomy on degenerative osteoarthritis, a three-dimensional (3D) finite element (FE) model of the human lower limb is constructed from a combination of magnetic resonance (MR) images and computed tomographic (CT) images that can provide anatomically suitable boundary conditions for a knee joint. Four cases, i.e., the intact meniscus, and the partial, sub-total, and total meniscectomy of the medial meniscus are modeled and simulated. We consider that the cartilage-to-cartilage contact area and the peak contact pressure in the meniscus may be significant parameters in evaluating degenerative osteoarthritis. Partial meniscectomy can be regarded as a better treatment than sub-total/total meniscectomy, and a high possibility of degenerative osteoarthritis is anticipated after total meniscectomy. Moreover, medial meniscectomy has the potential to bring about degenerative osteoarthritis in both the medial compartment and the lateral compartment of a knee joint.

STUDY DESIGN A descriptive cadaveric study measuring arterial tension. OBJECTIVE Anterior lumbar surgery is technically challenging due to perioperative vascular complications. Many studies suggest approaches based on the anatomy of the abdominal vessel for safe vascular mobilization. However, the tension in the vascular structure is also important for adequate exposure of the target lesion. It has been established that the tension in the lumbar nerve at the root level can be changed by a straight leg raise test and that the structure of the vascular connection is similar to that of the neural connection. Consequently, a change in leg position could affect the tension of lumbosacral vessels. The purpose of this study was to evaluate the effect of leg position on the tension of lumbosacral vessels. METHODS We dissected 10 unembalmed cadavers using the method described by Gumbs et al, using the Synframe system to expose the abdominal artery and vein. The left iliac artery and the distal abdominal aorta were retracted to the right side at the L4-L5 disc level by a measuring retractor to which a strain gauge was attached. The tension was checked at various angles of the hip joint and the motions of the abdominal arteries were monitored in 4 unembalmed cadavers using a C-arm fluoroscope. RESULTS The tension in the abdominal aorta at L4-L5 level was decreased by 2.9% to 21.8% in the hip-flexion position, and the motion of the arteries showed proximal displacement of the external iliac artery and the common iliac artery during the hip-flexed position and veins also showed the same pattern of displacement as artery. CONCLUSION The results of this study would be useful for not only spinal surgery but also other vascular surgeries, particularly, in cases where patients with conditions such as atherosclerosis or stenosis.

We measured 28 parameters of 202 femurs from Koreans by an automated geometric computation program using 3D models generated from computed tomography images. The measurement parameters were selected with reference to physical and forensic anthropology studies as well as orthopedic implant design studies. All measurements were calculated using 3D reconstructions on a computer using scientific computation language. We also analyzed sex and population differences by comparison with data from previous studies. Most parameters were larger in males than in females. The height, head diameter, head center offset, and chord length of the diaphysis, most parameters in the distal femur, and the isthmic width of the medullary canal were smaller in Koreans than in other populations. However, the neck-shaft angle, subtense, and width of the intercondylar notch in the distal femur were larger than those in other populations. The results of this study will be useful as a reference for physical and forensic anthropology as well as the design of medical devices suitable for Koreans.

To evaluate the entry zone of iliac screw fixation to maintain proper entry width and screw length. Computed tomography images of pelvic bones from 90 human cadavers were reconstructed into 3-dimensional models. In each model, a sectional image crossing the posterior superior iliac spine (PSIS) and anterior inferior iliac spine (AIIS) and consecutive sectional images up to 20 mm superiorly and inferiorly from the PSIS with 1-mm intervals aiming the AIIS were obtained. One virtual iliac screw with 10-mm diameter was introduced onto the PSIS at the middle and at the lateral and medial 1/4 points on the prominence of the posterior iliac spine. The entry width of the bony prominence and the corresponding maximal screw length available were evaluated for each entry point. The entry width was smallest on the inferior 20 mm (4.7 ± 3.0 mm) and gradually increased up to the superior 10 mm (19.1 ± 3.9 mm) sectional images. The maximal screw length was smallest on the superior 20 mm (76.7 ± 39.7 mm) and gradually increased down to the inferior 10 mm (112.3 ± 15.1 mm) sectional images. The maximal screw lengths were significantly greatest at the most medial point and smallest at the most lateral point on the superior 20- and 10-mm sectional images and at the PSIS. The iliac screw fixation entry zone to maintain proper screw length and entry width is outlined from 20 mm superiorly to 10 mm inferiorly from the PSIS and is located more medially from the prominence of the posterior iliac spine.

Unicondylar knee arthroplasty (UKA) has gained popularity in the recent years for treating medial compartment osteoarthritis of the knee joint in the Asian population. There is little information about the anthropometry of the resected bony surfaces of the knee joint in these population groups for designing the appropriate size-matched UKA components. We studied the anthropometry of the resected medial tibial condyles in 50 male and 50 female Korean cadavers by using three-dimensional computer tomography. We measured the anteroposterior dimension, the mediolateral dimension at defined points and the condylar aspect ratio. These measurements were compared with similar dimensions of the tibial components from five conventionally used UKA designs. Statistical analysis was performed using Student's t-test, Paired t-test and Pearson's correlation coefficient. We found that three of the tibial component designs showed mediolateral overhang for the whole range of measured anteroposterior dimensions of the resected medial tibial condyles, whereas one of the designs (DePuy) showed mediolateral undersizing for the smaller AP dimensions and overhang for the larger AP dimensions of the resected medial tibial condyles. Another design (Smith and Nephew) showed mediolateral undersizing for the whole range of measured anteroposterior dimensions of the resected medial tibial condyle. We found a decrease in the condylar aspect ratio with increasing AP dimension for our cadaver population data. However, the majority of the conventional tibial prosthesis showed either a constant condylar aspect ratio or an increasing aspect ratio (DePuy) with the increasing AP dimension of the resected medial tibial condyle. Our study may provide guidelines for designing appropriate tibial UKA components for a majority of Asian sub-populations and encourage similar studies in other population groups.