The elbow is the load-bearing joint during arm swing

Background@#Arm swing plays a role in gait by accommodating forward movement through trunk balance. This study evaluates the biomechanical characteristics of arm swing during gait. @*Methods@#The study performed computational musculoskeletal modeling based on motion tracking in 15 participants without musculoskeletal or gait disorder. A three-dimensional (3D) motion tracking system using three Azure Kinect (Microsoft) modules was used to obtain information in the 3D location of shoulder and elbow joints. Computational modeling using AnyBody Modeling System was performed to calculate the joint moment and range of motion (ROM) during arm swing. @*Results@#The mean ROM of the dominant elbow was 29.7°±10.2° and 14.2°±3.2° in flexion–extension and pronation–supination, respectively. The mean joint moment of the dominant elbow was 56.4±12.7 Nm, 25.6±5.2 Nm, and 19.8±4.6 Nm in flexion–extension, rotation, and abduction–adduction, respectively. @*Conclusions@#The elbow bears the load created by gravity and muscle contracture in dynamic arm swing movement.

Differences in Pilon Fractures According to Ipsilateral Fibular Injury Patterns: A Clinical Computed Tomography-Based Mapping Study

Background@#Preoperative verification of fracture morphology is essential for determining the definitive fixation strategy in the management of a pilon fracture. This study aimed to determine the correlation between fibular injury patterns and fracture morphologies and introduce clinical implications. @*Methods@#Computed tomography scans of 96 pilon fractures were retrospectively analyzed and divided into three types: intact fibula, simple fracture, and multifragment fracture. The principal fracture line and comminution zones were illustrated on a plafond template and diagrammatized on a 6 × 6 grid using PowerPoint software as fracture mapping. Correlations between fibular injury patterns and fracture morphologies, including comminution zones and principal fracture lines, were analyzed. @*Results@#The thickest comminution zone was most often located in the anterolateral quadrant. According to fibular injury patterns, the comminution zone of the multifragment group was placed two grids more lateral than that of other groups. Lateral exits of the principal fracture line in the multifragment group were much more concentrated within the fibular incisura. @*Conclusions@#In pilon fractures, a more complex fibular fracture pattern was related to the valgus position. Moreover, the articular fracture pattern of pilon fractures differed according to coronal angulation and fibular fracture pattern. These differences should influence the operative approach and placement of the plate.

Three-Dimensional Analysis of the Morphological Features in the Femur of Atypical Fracture and Practical Implications of Intramedullary Nailing

Purpose@#This study analyzed the morphological features of the contralateral femur without an atypical fracture by constructing a three-dimensional model with an actual size medullary canal. @*Materials and Methods@#Lateral and anterior bowing of the shaft were measured for 21 models, and the shape of the medullary canal was analyzed. To eliminate the projection error, the anteroposterior (AP) femur was rotated internally to the extent that the centerline of the head and neck, which is the ideal position of cephalomedullary nail screw, was neutral, and the lateral femur matched the medial and lateral condyle exactly. @*Results@#The lateral bowing and anterior bowing was an average of 5.5° (range, 2.8°-10.7°; standard deviation [SD], 2.4°) and 13.1° (range, 6.2°-21.4°; SD, 3.2°), respectively. In the area where lateral bowing increased, the lateral cortex became thicker, and the medullary canal was straightened. On the lateral femur, the anterior angle was increased significantly, and the diameter of curvature averaged 1,370.2 mm (range, 896-1,996 mm; SD, 249.5 mm). @*Conclusion@#Even if the anterolateral bowing increases in the atypical femur, the medullary canal tends to be straightened in the AP direction. So, it might be considered as a reference to the modification of an intramedullary nail to increase the conformity.

Fixation Options of Unstable Posterior Pelvic Ring Disruption: Ilio-Sacral Screw Fixation, S2AI Fixation, Posterior Tension Band Plate Fixation, and Spino-Pelvic Fixation

The fixation methods that can be used for unstable posterior pelvic ring injuries have undergone many innovative changes due to the recent development of surgical and imaging techniques. After understanding the appropriate indications of first and second sacroiliac screw fixation and spinopelvic fixation, innovative methods, including the trans-sacral screw fixation, posterior tension-band plate fixation, and the S2AI screw, would be chosen and applied. Considering the anatomical complexity and proximity to the surrounding vessels and nerves in the posterior fixation, the safe zone according to the fixation options should be well understood in preoperative planning. Moreover, the functional reduction of the posterior pelvic ring through the reduction and fixation of the anterior lesion should be achieved before placing the implant to reduce the number of malposition-related complications.

Computational Simulation of Multiple Cannulated Screw Fixation for Femoral Neck Fractures and the Anatomic Features for Clinical Applications

PURPOSE: To identify the anatomic features for clinical applications through a computational simulation of the fixation of three cannulated screws for a femoral neck fracture. MATERIALS AND METHODS: Thirty cadaveric femurs underwent computed tomography and the images were transferred to the Mimics® program, resulting in three-dimensional proximal femur models. A three-dimensional scan of the 7.0 mm cannulated screw was performed to enable computerized virtual fixation of multiple cannulated screws for femoral neck fractures. After positioning the screws definitively for cortical support, the intraosseous position of the cannulated screws was evaluated in the anteroposterior image and axial image direction. RESULTS: Three cannulated screws located at the each ideal site showed an array of tilted triangles with anterior screw attachment and the shortest spacing between posterior and central screws. The central screw located at the lower side was placed in the mid-height of the lesser trochanter and slightly posterior, and directed toward the junction of femoral head and neck to achieve medial cortical support. All the posterior screws were limited in height by the trochanteric fossa and were located below the vastus ridge, but the anterior screws were located higher than the vastus ridge in 10 cases. To obtain the maximum spacing of the anterior and posterior screws on the axial plane, they should be positioned parallel to the cervical region nearest the cortical bone at a height not exceeding the vastus ridge. CONCLUSION: The position of cannulated screws for cortical support were irregular triangular arrangements with the anterosuperior apex. The position of the ideal central screw in the anteroposterior view was at the mid-height of the lesser trochanter toward the junction of the femoral head and neck, and the anterior and posterior screws were parallel to the neck with a maximal spread just inferior to the vastus ridge.

The Determination of Optimal Entry Point for Proximal Femoral Nail Antirotation-II by Fluoroscopic Simulation: A Cadaveric Study

PURPOSE: This study seeks to determine the anatomically optimal entry point of proximal femoral nail antirotation-II (PFNA-II®) according to geographic features of Korean cadaveric femoral trochanters for successful reduction of osteoporotic proximal femoral fractures. MATERIALS AND METHODS: Forty-three adult cadaveric femurs without previous fractures or surgeries were included. Anteroposterior (AP) and lateral images of all femurs and PFNA-II® were taken with an image intensifier. Using the image synthesis process via the image editing program (Adobe Photoshop CS6), the optimal entry point was verified and compared with the tip of the greater trochanter (GT) and the cervicotro-chanteric junction on AP images, as well as the width of the trochanter and the neck on lateral images. RESULTS: The optimal entry point of PFNA-II® was an average distance of 9.1 mm (range, 7–15 mm) medially from the tip of GT on AP images. The center of the nail was located at an average of 30% (range, 21%–44%) area from the posterior margin of the middle neck, which is an average area of 38% (range, 26%–48%) from the posterior cortex of the trochanter on lateral images. Furthermore, the ideal entry point was at the extended line of the cervico-trochanteric junction. CONCLUSION: The optimal entry point, which was found to be medial to the tip of the GT and posterior to the center of the middle femoral neck and the trochanter, was at on the extended line of the cervicotrochanteric junction.

Analysis of Low-Energy Trochanter Fracture Using the Multiplanar Computed Tomography Image: Application for Intramedullary Nail Fixation

PURPOSE: The purpose of this radiologic study was to evaluate the geographic patterns of low-energy trochanteric fractures using multiplanar computed tomography (CT) images for application of intramedullary nailing. MATERIALS AND METHODS: In this study, 117 trochanteric fractures (stable fracture, 39 cases, unstable fractures, 78 cases) sustained from simple slip-down were assessed. The mean age was 78.4 years (range, 60-96 years). Multiplanar CT images were assessed for evaluation of geographic features of trochanteric fracture, and the fracture exit and geographic patterns were analyzed. RESULTS: The medial and lateral exit of the trochanteric fracture showed no statistical difference by age, bone density, and comorbid disease. The exit was located at an average distance of 10.2 mm (range, 1.0-22.2 mm) from the tip of the greater trochanter (GT), and the medial exit, average distance of 8.1 mm (range, 0.0-18.3 mm) from the tip of the lesser trochanter. It was also found that there was no comminution around the anteromedial cortex of the fracture, and its contact loss was from fracture deformity. CONCLUSION: Because of no comminution, the contact restoration of the anteromedial cortex resulted in correction of fracture deformity and reduction. Trochanteric nailing by GT tip could be fixed through the proximal fragment of the fracture because the lateral exit is placed at an average distance of 10.2 mm from the GT tip.

Conformity of Proximal Humerus Internal Locking Plate System (PHILOS) and Anatomic Features of Proximal Locking Screws: Cadaveric Study / 대한정형외과학회잡지

PURPOSE: The purpose of this cadaveric study was to evaluate the conformity of the anatomically preshaped proximal humerus internal locking plate system (PHILOS) to the humeri of the Korean and anatomical features of nine locking screws for the proximal humerus. MATERIALS AND METHODS: This study included 20 adult humeri (average length 30.2 mm) with no deformity or previous surgery. PHILOS was applied to the lateral surface of the proximal humerus according to the contour. Then, the distance from the outer surface of the plate to the greater tuberosity and bicipital groove was measured. After K-wires were passed through the proximal locking guide, the intra-osseous length of K-wire and the configuration of the K-wire exit were evaluated. RESULTS: The overall conformity of PHILOS was excellent at the lateral aspect of the proximal humerus. The tip of the plate had an average distance of 3.6 mm (range, 1.4-6.6 mm; standard deviation [SD], 1.27) from the greater tuberosity and 2.5 mm (range, 0.0-4.6 mm; SD, 1.24) at the bicipital groove and the average intra-osseous length of K-wire through the locking guide was 41.1 mm (range, 23.5-53.7 mm). K-wires were evenly penetrated through the humeral head. On H8 and H9, the bottom hole of PHILOS is closely located at the most inferior area of the humeral articular surface. The bicipital groove was pierced by K-wires of H5, which was the middle hole of PHILOS in four cases (20%). CONCLUSION: PHILOS had excellent conformity with the proximal humerus and K-wires through the locking guide were evenly penetrated through the humeral head. However, much care should be taken in piercing of the bicipital groove in H5.

Surgical Fitness for Trochanteric Fracture in Elderly: Prospective Study

PURPOSE: The purpose of this study was to evaluate the risks of undergoing intramedullary nailing with minimum surgical optimization (fast-track) for geriatric trochanter fracture due to fall from a standing height. MATERIALS AND METHODS: From May 2006 to August 2013, 48 fractures were enrolled in fast-track, and were an average age of patients was 77.6 years (range, 62-97 years). They underwent primary testing for anesthesia, including basic body fluid test, arterial blood, electrocardiography, and chest radiographs. The time from visit to surgery was 28.9 hours (range, 1-96 hours). RESULTS: During hospitalization, there was one case of stress-induced cardiac arrest; however, other complications, infection, and 30-day mortality did not occur. According to preoperative classic test, the average albumin was 3.45 g/dl, blood sugar, 169 mg/dl, blood urea nitrogen, 20.5 mg/dl, Cr, 1.5 mg/dl, Na, 135.3 mEq/L, and K, 4.21 mEq/L. The average PaCO2 of arterial blood was 37.6 mmHg. CONCLUSION: We found that the fast-track for trochanteric fracture due to slip-down was relatively safe, and could be considered as a therapeutic approach.

Granulation Tissue Formed by Stimulating K-Wire Mimicking Tuberculous Cervical Lymphadenopathy: A Case Report

Pins and wires are still used frequently in surgeries of the shoulder; however, these can cause breakage or migration to surrounding tissues, leading to complications. We report on case of a patient with a neck mass who had a past history of pulmonary tuberculosis and distal clavicle fracture with internally fixated state. She was misdiagnosed as tuberculous cervical lymphadenopathy and treated for approximately one year, but was finally revealed as granulation tissue around the internally fixated distal clavicle fracture site, thus, mass excision and metal removal was performed. This case shows the importance of a proper selection device, internal fixation technique, duration, and close follow-up after the operation.

Tumor Treated by Endoscopy

BACKGROUND: This study was conducted to examine the clinical usefulness and efficacy of endoscopic curettage on benign bone tumor. METHODS: Thirty-two patients (20 men and 12 women) with benign bone tumor were included in the study. The patients were aged between five and 76 years; the mean follow-up period was 27.05 months (range, 9.6 to 39.9 months). The primary sites include simple bone cyst (9 cases), fibrous dysplasia (6 cases), enchondroma (5 cases), non-ossifying fibroma (4 cases), bone infarct (3 cases), aneurysmal bone cyst (1 case), chondroblastoma (1 case), osteoblastoma (1 case), intraosseous lipoma (1 case), and Brodie abscess (1 case). A plain radiography was performed to assess the radiological recovery. Radiological outcomes, including local recurrence and bone union, were evaluated as excellent, good, poor, and recurred. RESULTS: In our series, there were 27 cases (84.4%) of good or better outcomes, six cases (18.8%) of complications (4 local recurrence, 1 wound infection, and 1 pathologic fracture). CONCLUSIONS: Our results showed that endoscopic curettage and bone graft had a lower rate of recurrence and a higher cure rate in cases of benign bone tumor. It can, therefore, be concluded that endoscopic curettage and bone graft might be good treatment modalities for benign bone tumors.

Biologic Fixation through Bridge Plating for Comminuted Shaft Fracture of the Clavicle: Technical Aspects and Prospective Clinical Experience with a Minimum of 12-Month Follow-up

For comminuted shaft fracture of clavicle, the operative goal, aside from sound bone healing without complications of direct reduction, is maintenance of the original length in order to maintain the normal biomechanics of adjacent joint. Our bridge plating technique utilizing distraction through a lumbar spreader was expected to be effective for restoring clavicular length with soft tissue preservation. However, there are two disadvantages. First, there is more exposure to radiation compared to conventional plating; and second, it is difficult to control the rotational alignment. Despite these disadvantages, our technique has important benefits, in particular, the ability to preserve clavicular length without soft tissue injury around the fracture site.

Anatomical Study of the Pronator Quadratus Muscle and Comparison to Fracture Sites of the Distal Radius / 대한정형외과학회잡지

PURPOSE: To collect data regarding the pronator-sparing approach using an anatomical study, which compared the fractures of the distal radius and pronator quadratus (PQ) muscle of an adult cadaveric radius. MATERIALS AND METHODS: Fourteen adult cadaver wrists that did not have previous fractures or previous surgery and computed tomography data 32 fractures of the distal radius, were obtained. The size of the distal fracture fragment was measured using the picture archiving and communication system. The distance between the distal margin of the PQ muscles and the articular margin was measured using a caliper. RESULTS: The PQ muscles had an average distance of 10.9 mm (range, 8-13 mm) from the radial styloid process and 10 mm (range, 8-12 mm) from the distal radioulnar joint (DRUJ). The fracture sites were located an average of 21.8 mm (range, 10-39 mm) from the radial styloid process and an average of 14.4 mm (range, 10-28 mm) from the DRUJ. Distal radial fractures overlapped an average of 11.8 mm from the radial styloid process and an average of 3.5 mm from the DRUJ. CONCLUSION: The pronator-sparing approach could be applied to a functionally reduced fracture because the non-overlapping area of the distal fracture fragment was > or =10 mm and it is possible to repair the anatomic plate without detaching the PQ muscle.

Radiation Exposure Over the Course of a Year from an Image Intensifier in the Orthopaedic Operating Room

PURPOSE: To measure the annual radiation exposure of staff in the orthopaedic surgical room. MATERIALS AND METHODS: From January 2010 to December 2010, we measured the radiation exposure of a tumor surgeon, spine surgeon, trauma surgeon, six residents, and six scrub nurses. Radiation was monitored with the use of thermoluminescent dosimeters placed on the chest under the lead apron. The annual dose of radiation exposure was compared to the maximum yearly permissible dose (20 mSv). During the study period, the trauma surgeon made a deliberate effort to minimize the radiation time and maintain a distance of 1 m from the image intensifier. RESULTS: The annual exposure levels were 0.04 mSv (radiation time, 34 min 50 s), 0.08 mSv (151 min 46 s), and 0.12 mSv (135 min 27 s) for the tumor surgeon, trauma surgeon, and spine surgeon, respectively. The mean exposure was 0.0146 mSv (range, 0.4~0.39 mSv) for the residents and 0.06 mSv (range, 0.04~0.13 mSv) for the scrub nurses. Overall, the annual radiation exposure was 0.2~1.95% of the maximal yearly permissible dose. Despite the longer period of radiation exposure, the trauma surgeon was exposed to a lower dose of radiation than the spine surgeon. CONCLUSION: The annual radiation exposure of a trauma surgeon can be reduced by a deliberate effort to decrease exposure time and maintain a distance of at least 1 m from the image intensifier.

Minimally Invasive Plate Osteosynthesis for the Upper Extremity Fracture Using a Lumbar Spreader: Surgical Technique

The minimally invasive plate osteosynthesis (MIPO) which is extensively performed, is very dependent on the indirect reduction technique to prevent the exposure of fracture sites. Indirect reduction with the use of the femoral distractor is a much more efficient technique to restore the length in the fracture of lower limbs. However, the femoral distractor cannot be used for fracture of upper limbs, and other instruments for indirect reduction have not yet been reported. Therefore, we introduce the novel indirect reduction technique with the use of the lumbar spreader for the MIPO of upper limbs.

Axial Malalignment after Minimally Invasive Plate Osteosynthesis in Distal Femur Fractures with Metaphyseal Comminution / 대한정형외과학회잡지

PURPOSE: We wanted to report on the functional results and the presence of axial malalignment after performing minimally invasive plate osteosynthesis in distal femur fractures with metaphyseal comminution. MATERIALS AND METHODS: Between March 2007 and June 2009, fifteen patients with distal femur fractures and metaphyseal comminution were treated with minimally invasive plate osteosynthesis, and they were followed for a mean of 17.0 months (range: 12-40 months). The fractures according to the AO/OTA classification were two cases of 33A and thirteen cases of 33C, and seven cases were open fracture. We analyzed the axial malalignment and functional results according to bone union and Sanders' score. RESULTS: All the fractures were united without a bone graft after a mean of 20.4 weeks (range: 16-26 weeks) after the definitive plate fixation. One case had superficial infection and a stiff knee. The average ROM of the knee was 123.6degrees. The average Sanders' score was 33.0, and the results were five cases of excellent results, eight cases of good results and two cases of fair results. There was axial malalignment such as varus malunion in 3 cases and valgus malunion in 2 cases and the average shortening of the limb length was 7.9 mm (range: 0.3-21.9 mm). CONCLUSION: Minimally invasive plate osteosynthesis in a distal femur fracture with metaphyseal comminution provides satisfactory outcomes. However, this should be approached with caution because of the possibility of axial malalignment.

Treatment of the Intertrochanteric Femoral Fracture with Proximal Femoral Nail: Nailing Using the Provisional K-wire Fixation

PURPOSE: To evaluate the efficiency of provisional K-wire fixation in intertrochanteric fractures treated with proximal femoral nail (PFN). MATERIALS AND METHODS: Twenty seven patients (by AO/OTA classification, A1 8 cases, A2 19 cases) were treated with PFN with percutaneous reduction and provisional K-wire fixation, and followed a mean 24.5 months. The adequacy of fracture reduction was assessed by Fogagnolo's classification and reestablishment of bone-to-bone contact with the medial anatomy. Functional results were evaluated by postoperative complications, Jensen's method and Harris hip score (HHS). RESULTS: In all cases, the bone-to-bone contact with the medial anatomy was reestablished by percutaneous reduction and examination of Fogagnolo's classification showed a good reduction. The technical complications and error of starting point were not occurred. The mean HHS was 76.5 and means Jensen's grade was 2.1 grades. Complications included excessive sliding in 1 case and early cutting-out of screw in 1 case. CONCLUSION: The provisional K-wire fixation in trochanteric fracture treated with PFN had an advantage in preventing technical complications because it facilitates a nail insertion in ideal position.

Intramedullary Nailing for Complex Fractures of the Proximal and Midshaft of the Humerus

PURPOSE: To evaluate the results of antegrade interlocking intramedullary nailing for complex fractures of the proximal and midshaft of the humerus. MATERIALS AND METHODS: We retrospectively analyzed the clinical and radiologic results in 11 cases, which were treated by antegrade interlocking intramedullary nail. We assessed clinical outcomes according to ASES scoring system and radiological result. RESULTS: All cases had bony union and the mean union period was 14.7 weeks. Postoperative complications were 1 loss of fixation, 2 proximal protrusion of nail and 2 temporary shoulder pain. A case with loss of fixation was treated open reduction and refixation and had union at 14 weeks postoperatively. The mean ASES score was 85.9 and the clinical outcomes were 4 excellent, 5 good, 1 fair and 1 poor. CONCLUSION: Intramedullary nailing for complex fractures of the proximal and midshaft of the humerus can offer a reliable treatment option.

Long-Term Survivals of Stage IIB Osteosarcoma: A 20-Year Experience in a Single Institution

BACKGROUND: The purpose of this study is to evaluate the disease-free survival (DFS) and overall survival (OS) of patients with stage IIB osteosarcoma at a single institution for 20 years and to compare the results according to the chemotherapy protocols. METHODS: From Jan 1988 to Nov 2008, 167 patients with osteosarcoma were treated at our hospital and among them, 117 patients (67 males and 50 females) with stage IIB osteosarcoma were evaluable. Their mean age was 22.6 years (range, 8 months to 71 years). Seventy-eight cases underwent the modified T10 (M-T10) protocol (group 1), 23 cases underwent the T20 protocol (group 2) and 16 cases underwent the T12 protocol (group 3). The DFS and OS were calculated and compared according to the chemotherapy protocols. RESULTS: At a mean follow-up of 78.9 months, 63 patients were continuously disease-free (63/117), 6 patients were alive after having metastatic lesions, 7 patients died of other cause and 41 patients died of their disease. The 5- and 10-year OS rates were 60.2% and 44.8%, respectively and the 5- and 10-year DFS rates were 53.5% and 41.4%, respectively. There was no significant difference of the OS and DFS between the chemotherapy protocols (p = 0.692, p = 0.113). CONCLUSIONS: At present, we achieved success rates close to the internationally accepted DFS and OS. We were able to achieve the higher survival rates using the M-T10 protocol over the 20 years. However, there was no significant difference of results between the chemotherapy protocols. We think the M-T10 protocol will achieve more favorable results in the near future.

Management of Fractures of Distal Tibia by Minimally Invasive Plate Osteosynthesis through an Anterior Approach / 대한정형외과학회잡지

PURPOSE: To evaluate functional results and complications after minimally invasive plate osteosynthesis through an anterior approach for distal tibial fractures, including pilon fracture. MATERIALS AND METHODS: Between March 2007 and December 2008, thirteen patients with fractures of the distal tibia were treated with minimally invasive plate osteosynthesis through an anterior approach, and were followed for a mean of 16.2 months (range, 12-30 months). Fractures according to the AO/OTA classification were six 43A, four 43B and three 43C. We analyzed functional results by bone union, postoperative complications, and the Olerud and Molander ankle scoring system. RESULTS: All fractures were united after a mean of 15.7 weeks (range, 12 to 24 weeks) except one case. There were 2 cases of superficial wound infection, one case of fibular shortening and metal failure, and two cases of tibialis anterior tendon adhesion. The average functional score was 79 points (range, 35-95 points) and results were four excellent, six good and three fair. CONCLUSION: Minimally invasive plate osteosynthesis through an anterior approach may be used for distal tibial fracture with medial soft tissue injury, and has an advantage in that the metaphyseal and distal articular fracture are fixed at the same time through a single incision However, it should be approached with caution because of the risk of complications due to the anterior approach, such as iatrogenic injury of the tibialis anterior tendon.