• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1222-1227
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• 2003

Pitting wear is a dominant form of polyethylene surface damage in total knee replacements, and may originate from surface cracks that propagate under repeated tribological contact. In this study, stress intensity factors, $K_{I}$ and $K_{II}$, were calculated for a surface crack in a polyethylene - CoCr - bone system under the rolling and/or sliding contact pressures. Crack length and load location were considered in determination of probable crack propagation mechanisms and fracture modes. Positive $K_{I}$ values were obtained for shorter cracks in rolling contact and for all crack lengths when the sliding load was apart from the crack. $K_{II}$, was the greatest when the load was directly adjacent to the crack $(g/a={\pm}1)$. Sliding friction caused a substantial increase of both $K_{I}^{max}$ and $K_{II}^{max}$. The effective Mode I stress intensity factors, $K_{eff}$, were the greatest at $g/a={\pm}1$, showing the significance of high shear stresses generated by loads adjacent to surface cracks. Such behavior of $K_{eff}$ suggests mechanisms for surface pitting by which surface cracks may propagate along their original plane under repeated rolling or sliding contact.

• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.557-563
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• 2022

The cortical bone thickness of the tibia is related to fracture risk and overall bone status. The present study aims to investigate the feasibility of two different ultrasonic methods for measuring the cortical bone thickness in bovine tibia in vitro. In the reflection technique, the tibial cortical thickness was determined from ultrasonic reflections from the periosteum and the endosteum producing specific peaks in the signal envelope. In the axial transmission technique, the tibial cortical thickness was determined from ultrasonic guided wave velocities measured along the axial direction of the tibia. The cortical bone thickness determined by using the reflection technique correlated significantly with that measured by using a caliper, with a Pearson's correlation coefficient of r = 0.97 (p < 0.0001). In contrast, the correlation coefficients for the axial transmission technique were r = 0.92 (p < 0.0001) for the first arriving signal method and r = 0.89 (p < 0.0001) for the slow guided wave method. Clinical feasibility should be demonstrated with an in vivo application to address the question whether the ultrasonic methods presented here could be useful as a screening tool for osteoporosis and potentially could be applied to other skeletal sites such as the femur and the radius.

• Journal of Korean Foot and Ankle Society
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• v.27 no.3
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• pp.93-98
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• 2023

Purpose: This study compared the functional and cosmetic treatment outcomes of intramedullary nailing (IM nail) and minimally invasive plate osteosynthesis (MIPO) for distal tibia shaft fractures. Materials and Methods: Forty-eight patients with distal tibia shaft fractures (distal 1/3 of the diaphysis, AO/OTA [AO Foundation/Orthopaedic Trauma Association]) 43 managed by an IM nail (n=30) or MIPO (n=18) who had minimum one-year follow-up were enrolled in this study. The radiological, functional, and cosmetic outcomes in the two groups were compared retrospectively. Results: All patients achieved bone union. The mean bone union time of the IM nail and MIPO groups was 18.5 and 22.6 weeks, respectively (p=0.078). One patient in the MIPO group showed posterior angulation and valgus deformity of more than five degrees. The mean American Orthopaedic Foot and Ankle Society (AOFAS) functional scores were similar: 83.3 in the IM nail group and 84.6 in the MIPO group (p=0.289). The most salient difference was the cosmetic result of the surgical scar. The length of the scars around the ankle in the IM nail group was significantly smaller than the MIPO group (2.6 cm vs. 10.6 cm; p=0.035). The patient satisfaction survey of surgical scars revealed a significantly higher satisfaction rate in the IM nail group than in the MIPO group (93% vs. 44%; p<0.001). Conclusion: This study showed that both treatment methods for distal tibia shaft fractures have similar therapeutic efficacy regarding the radiological and functional outcomes. On the other hand, the IM nail technique showed superior cosmetic outcomes than the MIPO technique. IM nails may be more recommended in patients with high demand for cosmetic results.

• Journal of Korean Foot and Ankle Society
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• v.24 no.2
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• pp.81-86
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• 2020

Purpose: Ankle fractures with dislocations and pilon fractures at the distal tibia are usually associated with soft tissue damage caused by high-energy damage. Recently, a two-stage operation to perform internal fixation after the application of external fixation devices for stabilizing soft tissues has been accepted as the treatment of choice. This paper reports the clinical result of these injuries treated with threaded trans-calcaneal pin external fixation devices. Materials and Methods: Thirty-three patients diagnosed with ankle fractures with dislocations or tibial pilon fractures without open wounds. They underwent surgical treatment with threaded trans-calcaneal pin external fixation from January 2008 to February were enrolled in this study. This study evaluated the visual analogue scale (VAS), foot function index (FFI), and Olerud & Molander score as well as whether complications occurred. Results: The average VAS showed a meaningful decrease (p<0.001) from 7.4 before surgery to 2.6 after application of the external fixation device, and 1.4 at 12 months after surgery. The FFI also decreased significantly from 84.3 preoperatively to 20.3 at 12 months postoperatively (p<0.001). The Olerud & Molander score averaged 71.4 points, showing good clinical results. Complete bone union was observed in all patients. One patient each underwent debridement due to wound necrosis and infection in the pin insertion site. At the final follow-up, seven patients had posttraumatic ankle joint arthritis, according to a radiological examination. Conclusion: Manual reduction and external fixation using a threaded trans-calcaneal pin is a suitable surgical technique that is easy to perform and shows good clinical outcomes in stabilizing soft tissue damage in fractures and dislocations of ankle fracture or tibia pilon fractures in foot and ankle injury.

• Journal of Korean Foot and Ankle Society
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• v.15 no.2
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• pp.51-57
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• 2011

Pilon fractures involving distal tibia remain one of the most difficult therapeutic challenges that confront the orthopedic surgeons because of associated soft tissue injury is common. To introduce and describe the diagnosis, current treatment, results and complications of the pilon fractures. In initial assessment, the correct evaluation of the fracture type through radiographic checkup and examination of the soft tissue envelope is needed to decide appropriate treatment planning of pilon fractures. Even though Ruedi and Allgower reported 74% good and excellent results with primary open reduction and internal fixation, recently the second staged treatment of pilon fractures is preferred to orthopedic traumatologist because of the soft tissue problem is common after primary open reduction and internal fixation. The components of the first stage are focused primarily on stabilization of the soft tissue envelope. If fibula is fractured, fibular open reduction and internal fixation is integral part of initial management for reducing the majority of tibial deformities. Ankle-spanning temporary external fixator is used to restore limb alignment and displaced intraarticular fragments through ligamentotaxis and distraction. And the second stage, definitive open reduction and internal fixation of the tibial component, is undertaken when the soft tissue injury has resolved and no infection sign is seen on pin site of external fixator. The goals of definitive internal fixation should include absolute stability and interfragmentary compression of reduced articular segments, stable fixation of the articular segment to the tibial diaphysis, and restoration of coronal, transverse, and sagittal plane alignments. The location, rigidity, and kinds of the implants are based on each individual fractures. The conventional plate fixation has more advantages in anatomical reduction of intraarticular fractures than locking compression plate. But it has more complications as infection, delayed union and nonunion. The locking compression plate fixation provides greater stability and lesser wound problem than conventional implants. But the locking compression plate remains poorly defined for intraarticular fractures of the distal tibia. Active, active assisted, passive range of motion of the ankle is recommended when postoperative rehabilitation is started. Splinting with the foot in neutral is continued until suture is removed at the 2~3 weeks and weight bearing is delayed for approximately 12 weeks. The recognition of the soft tissue injury has evolved as a critical component of the management of pilon fractures. At this point, the second staged treatment of pilon fractures is good treatment option because of it is designed to promote recovery of the soft tissue envelope in first stage operation and get a good result in definitive reduction and stabilization of the articular surface and axial alignment in second stage operation.

• Journal of Trauma and Injury
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• v.26 no.3
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• pp.163-169
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• 2013

Purpose: This study was conducted to confirm the anatomic conformity of the new periarticular locking plates designed by Zimmer on Korean adult bones and to identify the structures at risk during the application of these implants. Methods: The study was performed on the humerus, radius, and tibia of 10 adult cadavers(6 males and 4 females) procured from the cadaveric lab of our hospital. Anteroposterior (AP) and lateral X-rays were taken to confirm that the cadavers were free of any unusual lesions or anatomic variations. We used the 3.5-mm proximal humerus plate, 2.7-mm distal radius plate, 3.5- and 5.0-mm proximal tibia plates, and 3.5-mm distal tibia plate developed by Zimmer, Inc. (Zimmer periarticular locking plate). The longest plate from each group was used to confirm anatomical conformity. Standard approaches were used for each area, and soft tissue was retracted in order to pass the plate beneath the muscle. The position of the plate was confirmed using standard AP and lateral view X-rays. After this procedure had been completed, the region was dissected along the length of the implant to determine the conformity of the implant to bone and the penetrations of screws into the articular surface or violations of any vital structures, such as nerves, blood vessels, or tendons. Results: Excellent anatomical conformity was observed with Zimmer periarticular locking plates for Korean adults. The tibial nerve and the posterior tibial artery were found to be structures at risk when applying a distal tibial plate. Conclusion: Additional posterolateral fixation is recommended when dealing with cases of tibial plateau fracture when the fracture line extends to the posterolateral cortex. We recommend taking proper views using 10~15 degrees of internal rotation to ensure correct screw length and, thus, avoid penetration of vital structures and tendons.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.331-372
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• 2003

The purpose of study was to evaluate effects of low-intensity ultrasound and laser on healing of bone fracture. Twenty fracture patient were selected for this study(fourteen males, six females. mean aged 44.8) fracture area was humerus, tibia, forearm bones. The obtain result are as follows. 1. The result of this study were following that pain score was significantly reduced pre intervention compared with post intervention in male(P<.001). 2. The result of this study were following that pain score was significantly reduced pre intervention compared with post intervention in female(P<.001). 1. The result of this study were following that pain score was not appeared reduced pre intervention compared with post intervention in male and female(P<.001). 4. The result of this study were following that pain score was not appeared pre intervention compared with post intervention in male between age(P<.001). 5. The result of this study were following that pain score was not appeared pre intervention compared with post intervention in female between age (P<.001). 6. The result of this study were following that radiologic score was significantly reduced pre intervention compared with post intervention in male(P<.001). 7. The result of this study were following that radiologic score was significantly reduced pre intervention compared with post intervention in female(P<.001). 8. The result of this study were following that radiologic score was not appeared reduced pre intervention compared with post intervention in male and female(P<.001). 9. The result of this study were following that radiologic score was not appeared pre intervention compared with post intervention in male between ages(P<.001). 10. The result of this study were following that radiologic score was not appeared pre intervention compared with post intervention in female between ages(P<.001). 11. The result of this study were following that healing on fracture area was observed that reduced pre intervention compared with post intervention

• Journal of Korean Foot and Ankle Society
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• v.19 no.1
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• pp.35-38
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• 2015

The checkrein deformity describes tethering of the flexor hallucis longus tendon, which mainly occurs after fracture of the distal tibia. The deformity increases with dorsiflexion of the ankle and decreases or disappears with plantarflexion of the ankle. In some cases, the deformity may occasionally include the second and third toes. In the current study, the authors experienced secondary checkrein deformity of all lesser toes after open reduction and plate fixation for comminuted fracture of the calcaneus. As a treatment, plate and screws were removed, followed by an additional medial incision which showed a partially ruptured flexor digitorum longus tendon with severe adhesion. Resection of the adhesed tendon and tenodesis of its distal portion to the flexor hallucis longus was performed for correction of the checkrein deformity. Then the lessor toe checkrein deformity recovered immediately. The authors report on this rare lessor toe checkrein deformity after calcaneal fracture fixation with a review of literature.

• The Korean Journal of Nuclear Medicine
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• v.24 no.1
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• pp.124-132
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• 1990

It has been reported that hematoma is one of the most crucial factors in fracture healing since callus formation is disturbed by washing out the hematoma near a fracture site. However, it is not clear why the hamatoma is important and how it plays a role during the fracture healing. In order to investigate the role of hematoma in the process of fracture healing, the osteogenic potential by subperiosteal transplantation have been studied. Experimental fractures by operation were made at the mid-shaft of the tibia in New Zealand white rabbits. Removal of hematoma at the fracture site was done after 2 and 3 days from experimental fracture, and the removed hematoma was transplanted into the subperiosteal area at the mid-shaft of the ulna of each rabbit. As control groups, we have performed 3 different procedures 1) the hematoma was transplanted into the muscular layers at the thigh and forearm; 2) autologous blood clots were transplanted into the subperiosteal area of the ulna; and 3) sham operation without a transplantation into the subperiosteal area. After transplantation, serial bone scintigraphy and simple radiography were performed at 4 days, 1 week, and 2 weeks to detect an abnormality. The results of bone scintigraphy were positive in 5 of 6 experimental group. However, all in three control groups were negative. Histological observation of the positive bone revealed new bone formation with trabeculation. These results suggest the hematoma in fracture site has osteogenic potential in the subperiosteal area which can be demonstrable by bone scintigraphy and histologic findings. Therefore, it is considered that hematoma of the fracture site plays an important role in the process of fracture healing. Further biochemical investigation using various experimental models is mandatory to apply this preliminary result to the treatment of clinical delayed union or nonunion.

• Journal of Trauma and Injury
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• v.31 no.2
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• pp.103-106
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• 2018

Fat embolism refers to the presence of fat droplets within the peripheral and lung microcirculation with or without clinical sequelae. However, early diagnosis of fat embolism is very difficult because the embolism usually does not show at the computed tomography as a large fat complex within vessels. Forty-eight-year-old male with pedestrian traffic accident ransferred from a local hospital by helicopter to the regional trauma center by two flight surgeons on board. At the rendezvous point, he had suffered with dyspnea without any airway obstruction sign with 90% of oxygen saturation from pulse oximetry with giving 15 L of oxygen by a reserve bag mask. The patient was intubated at the rendezvous point. The secondary survey of the patient revealed multiple pelvic bone fracture with sacrum fracture, right femur shaft fracture and right tibia head fracture. Abdominal computed tomography was performed in 191 minutes after the injury and fat embolism with Hounsfield unit of -86 in his right common iliac vein was identified. Here is a very rare case that mass of fat embolism was shown within common iliac vein detected in computed tomography. Early detection of the fat embolus and early stabilization of the fractures are essential to the prevention of sequelae such as cerebral fat embolism.