• Title/Summary/Keyword: Failure of fixation

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Stabilization of Short Juxta-articular Fractures Using a Circular External Skeletal Fixator System in Dogs (개에서 원형외고정장치를 이용한 관절주위 골절의 안정화)

  • Cheong, Hye-Yeon;Kim, Joo-Ho;Cha, Jae-Gwan;Seol, Jae-Won;Kim, Min-Su;Lee, Hae-Beom
    • Journal of Veterinary Clinics
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    • v.31 no.6
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    • pp.523-526
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    • 2014
  • Three dogs were admitted for repair of bone fracture. Case 1 (Maltese, 1.8 kg, intact female, 5-month-old) and case 2 (poodle, 3.0 kg, intact female, 6-month-old) had non-weight bearing lameness in the left pelvic limb, and case 3 (mixed, 3.3 kg, intact female, age unknown) had non-weight-bearing lameness in the left thoracic limb. On orthopedic examination, there was pain, crepitus, palpable instability and substantial soft tissue swelling on the affected side. No neurological deficits were identified. Radiographs revealed left proximal metaphyseal tibial and fibular fractures in cases 1 and 2, and left proximal metaphyseal radial and ulnar fractures in case 3. All cases had closed long-bone fractures with short juxta-articular fracture segments. Under fluoroscopic guidance, proper placement of the ring fixation elements was confirmed during surgery. Two or three rings were used to stabilize fractures with traditional circular external skeletal fixators (CESF). Postoperative radiographs showed acceptable alignment and apposition of the previously identified fracture. Time to radiographic union ranged from 5 to 14 weeks and there were no signs of implant failure or pin tract infection. Functional outcomes were excellent in all cases. CESF can be successfully used to reduce short juxta-articular fractures in which bone plates or external skeletal fixation cannot be applied.

Operative Treatment of Displaced Proximal Humerus Fractures with the Angular Stable Locking Compression Plate (각안정 잠김 압박 금속판을 이용한 전위된 근위 상완골 골절에 대한 수술적 치료)

  • Kim, Dong-Wook;Kim, Chong-Kwan;Jung, Sung-Won;Kim, Hyeon-Soo
    • Clinics in Shoulder and Elbow
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    • v.14 no.1
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    • pp.27-34
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    • 2011
  • Purpose: We examined the clinical and radiological outcomes for displaced proximal humerus fractures that were treated with a PHILOS angular stable plate. Materials and Method: Forty four patients who underwent surgery between March 2007 and February 2010 were included in this study. All the cases were followed up for an average of 12 months. All the patients were examined and interviewed using the Visual Analog Scale (VAS) score, the Constant score and standardized X-rays to check the neck-shaft angle (NSA) and the presence of medial support. Results: The average Visual Analog Scale score was 2.8 points and the average Constant score was 70.5 points. The average neck shaft angle was $122.5^{\circ}$ and this was statistically significant between the good result group and the poor result group. There were 36 cases of the presence of medial support and 8 cases of the absence of medial support and the difference was statistically significant. Complications such as fixation failure happened in 12 cases. Conclusion: PHILOS angular stable plate fixation as an operative treatment for displaced proximal humerus fractures is a good and reliable treatment option.

Structural Performance of the Cast-in-place Anchor in Cracked Concrete used in Power Plant Facilities (균열 콘크리트에 매립된 발전설비 현장설치용 선 설치 앵커의 구조성능 평가)

  • Kim, Dong-Ik;Jung, Woo-young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.7
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    • pp.120-128
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    • 2019
  • It is very important to verify the seismic performance and stability of the power plant fixture in the domestic power plant, because earthquakes have increased in frequency around the world which resulted in the frequent occurrence of power plant damage caused by the failure of electric power facilities. In this study, through the on-site inspection of power plant fixation unit installed in domestic power plants, we carried out structural performance evaluation of the fixation unit anchor bolts installed on the concrete slabs. The field survey showed M12 J hook anchor bolts were used. Anchor bolt pullout and shear performance evaluation were performed based on ASTM E 488-96 standard. Moreover, artificial crack with the width of 0.5 mm was applied during the experiment based on ATM355.4 and ETAG 001. The comparison of M12 J hook anchor bolt pullout and shear test result to design value required in domestic and international design standard, show a satisfactory result. M12 J hook anchor pullout and shear performance was found to be about 35% and 7%, respectively, higher than the required design value.

Stress fracture in Vascularized fibular Grafts (혈관 부착 이식 비골에 발생한 피로골절)

  • Kim, Hyoung-Min;Kim, Youn-Soo;Lee, Kee-Haeng;Jeong, Chang-Hoon;Kim, Jun-Seok
    • Archives of Reconstructive Microsurgery
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    • v.10 no.1
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    • pp.18-22
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    • 2001
  • Purpose : The purpose of this study was to evaluate stress fracture of vascularized fibular grafts(VFG) by analyzing factors associated with stress fracture and the treatment results. Materials and Methods : From June 1985 to May 1998, 7 patients with stress fractures in the 38 patients with long bone defect who had vascularized fibular graft were evaluated with clinical and radiologic methods including grafted fibular length and hypertrophic index of de Boer. The average age of the patients was 35 years(range, $14{\sim}60$ years). The mean follow-up period was 20 months(range, $16{\sim}32$ months). Results: 7(18.4%) stress fractures occurred in 38 patients. Characteristics of the fractures were (1) all occurred at lower extremity of male patients treated with VFG for long bone defected caused by infected nonunion; (2) all occurred 10 months at the average(range, $4{\sim}17$ months) after VFG; and (3) the length and hypertrophic index of grafted fibula had no influence on the incidence of stress fracture. Union was obtained in 3 patients by conservative treatment. 4 patients obtained union by internal fixation; one at immediately onset of fracture; and three after failure of conservative treatment who had fracture around the knee joint. Conclusion : Stress fracture may occur during the first one year after vascularized fibular graft and more attention must be paid for prevention of it, especially in the cases of infected nonunion. Stress fracture around the knee joint was expected to lead to a good result of early union by operative treatment.

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Cross Leg Flap Using Septocutaneous Flap and Cast Immobilization (중격피부 피판과 석고붕대 고정을 이용한 하지 교차 피판술)

  • Choi, Soo-Joong;Yoon, Tae-Kyung;Lee, Young-Ho;Lee, Eung-Joo;Chang, Ho-Guen;Chang, Jun-Dong
    • Archives of Reconstructive Microsurgery
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    • v.7 no.2
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    • pp.165-174
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    • 1998
  • Large soft tissue defect of the ankle and foot can present a difficult reconstructive problem to the surgeon. Local musculocutaneous, local fasciocutaneous or free flap is usually the first choice for providing soft tissue coverage. However, in certain situations, local flaps from the same leg and free flap may not be suitable. These include extensive soft tissue injury, where no suitable recipient vessels can be found, previous local fasciocutaneous flap or free flap failure. In such cases, we have utilized the septocutaneous(fasciocutaneous) branch flap of posterior tibial artery from the opposite healthy limb. We present 5 cases of cross leg flaps, which have been modernized with current understanding of vascular anatomy and current fixation technology. All cross leg flaps were based on the axial blood supply of the fasciocutanous branch of the posterior tibial artery. Cross-clamping with bowel clamp was used to create intermittent periods of ischemia. Adjacent lower extremity joints were exercised during the periods of attachment. The results have been quite encouraging. We conclude that the cross leg flap using septocutaneous flap and cast immobilization can be successfully and expeditiously used to cover defects of the ante and foot.

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Surface Tribology of Total Ankle Joint Replacement (인공발목관절의 표면 마모 특성)

  • Jeong, Yong-Hoon;Jung, Tae-Gon;Yang, Jae-Woong;Park, Kwang-Min;Lee, Su-Won
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2016.11a
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    • pp.117-117
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    • 2016
  • Total ankle replacement (TAR) is a visible option in the surgical treatment of degenerative or inflammatory diseases of ankle joint. it is attributed to the current TAR which has improvements in surgical technique, uncemented implant fixation and minimally constrained articulation. In the clinical result, they can show promised surgical result when compared to earlier attempts in TAR. However, TAR is still not as successful as total knee replacement (TKR) or total hip replacement (THR), it needs to be note that there are limitations in concerning of long term performance of TAR, the high failure rate still associated with wear of the PE (polyethylene) component that has related with their material property and surface roughness. The aim of this study was to introduce the tribology characteristics of total ankle joint prosthesis with one of TDR model which was fabricated to try multi-axis wear test as a region of motion in ankle joint. The wear specimen of TDR was prepared with Ti-6Al-4V alloy and UHMWPE (ultra-high molecular weight polyethylene) for tibia-talus and bearing component, respectively. A wear test was carried out using a Force 5 (AMTI, Massachusetts, US) wear simulator which can be allowed to move in three axis to flexion-extension ($+3^{\circ}{\sim}-6^{\circ}$), internal-external axial rotation (${\pm}5^{\circ}$), as well as sinusoidal compressive load (1.6 kN, R=10). All tests were performed following standard ISO 14243, wear rate was calculated with weight loss of UHMWPE bearing while the specimen has tested at certain cycles. As based on the preliminary results, wear rate of UHMWPE bearing was $7.9{\times}10^{-6}mg/cycles$ ($R^2=0.86$), calculated loss weight until $10^7cycles$ was 79 mg, respectively.

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Tibiotalocalcaneal Arthrodesis Using Retrograde Compressive Intramedullary Nail (역행성 압박 골수내 금속정을 이용한 경골거골종골 관절 유합술)

  • Song, Moo Ho;Kim, Bu Hwan;Ahn, Seong Jun;Kang, Suk Woong;Kim, Young Jun;Kim, Dong Hwan;Yoo, Seong Ho
    • Journal of Korean Foot and Ankle Society
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    • v.18 no.4
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    • pp.202-207
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    • 2014
  • Purpose: The purpose of this study was to evaluate the radiological and clinical outcomes of tibiotalocalcaneal arthrodesis using retrograde compressive intramedullary nail for patients with complex hindfoot problems, including Charcot arthropathy, osteonecrosis of talus, combined arthritis of the ankle and subtalar joint, failure of previous ankle arthrodesis, and failed total ankle arthroplasty. Materials and Methods: Eighteen consecutive patients (10 men and 8 women) with an average age of 54 years (range, 42~72 years) underwent tibiotalocalcaneal arthrodesis using retrograde compressive intramedullary nail fixation. The mean duration of follow-up was 16 months (range, 12~23 months). Radiological evaluation included assessment of the union status of ankle and subtalar joints. Clinical evaluations included visual analogue scale (VAS) for pain and patient satisfaction, and postoperative complications were analyzed. Results: Radiological union was achieved in 14 ankle joints (77%) and 16 subtalar joints (88%) at an average of 16 weeks (range, 14~40 weeks) and 14 weeks (range, 12~24 weeks), respectively. The preoperative VAS were 4.6 (range, 4~8) at rest and 8.2 (range, 7~10) during walking, and the postoperative VAS were 2.2 (range, 0~3) and 4.6 (range, 4~6), respectively (p<0.05). There were 6 nonunions (4 ankle joints and 2 subtalar joints), 3 tibia fractures, 2 delayed union of ankle joints, and 2 breakage of the implant. Conclusion: Tibiotalocalcaneal arthrodesis using retrograde compressive intramedullary nail may be considered as a viable option in patients with complex hindfoot problems.

A Case of Pedicle Screw Loosening Treated by Modified Transpedicular Screw Augmentation with Polymethylmethacrylate

  • Kang, Suk-Hyung;Kim, Kyoung-Tae;Park, Seung-Won;Kim, Young-Baeg
    • Journal of Korean Neurosurgical Society
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    • v.49 no.1
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    • pp.75-78
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    • 2011
  • We report a case of pedicle screw loosening treated by modified transpedicular screw augmentation technique using polymethylmethacrylate(PMMA), which used the anchoring effect of hardened PMMA. A 56-year-old man who had an L3/4/5 fusion operation 3 years ago complained of continuous low back pain after this operation. The computerized tomography showed a radiolucent halo around the pedicle screw at L5. We augmented the L5 pedicle screw with modified pedicle screw augmentation technique using PMMA and performed an L3/4/5 pedicle screw fixation without hook or operation field extension. This modified technique is a kind of transpedicular stiffness augmentation using PMMA for the dead space around the loosed screw. After filling the dead space with 1-2 cc of PMMA, we inserted a small screw. Once the PMMA hardened, we removed the small screw and inserted a thicker screw along the existing screw threading to improve the pedicle screws' pullout strength. At 10 months' follow-up, x-ray showed strong fusion of L3/4/5. The visual analogue scale (VAS) of his back pain was improved from 9 to 5. This modified transpedicular screw augmentation with PMMA using anchoring effect is a Simple and effective surgical technique for pedicle screw loosening. However, clinical analyses of long-term follow-up and biomechanical studies are needed.

The Effect of Uncinate Process Resection on Subsidence Following Anterior Cervical Discectomy and Fusion

  • Lee, Su Hun;Lee, Jun Seok;Sung, Soon Ki;Son, Dong Wuk;Lee, Sang Weon;Song, Geun Sung
    • Journal of Korean Neurosurgical Society
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    • v.60 no.5
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    • pp.550-559
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    • 2017
  • Objective : Subsidence is a frequent complication of anterior cervical discectomy and fusion. Postoperative segmental micromotion, thought to be a causative factor of subsidence, has been speculated to increase with uncinate process resection area (UPR). To evaluate the effect of UPR on micro-motion, we designed a method to measure UPR area based on pre- and postoperative computed tomography images and analyzed the relationship between UPR and subsidence as a proxy of micro-motion. Methods : We retrospectively collected clinical and radiological data from January 2011 to June 2016. A total of 38 patients (53 segments) were included. All procedures included bilateral UPR and anterior plate fixation. UPR area was evaluated with reformatted coronal computer tomography images. To reduce level-related bias, we converted UPR area to the proportion of UPR to the pre-operative UP area (pUPR). Results : Subsidence occurred in 18 segments (34%) and positively correlated with right-side pUPR, left-side pUPR, and the sum of bilateral pUPR (sum pUPR) (R=0.310, 301, 364; p=0.024, 0.029, 0.007, respectively). Multiple linear regression analysis revealed that subsidence could be estimated with the following formula : $subsidence=1.522+2.7{\times}sum\;pUPR$($R^2=0.133$, p=0.007). Receiver-operating characteristic analysis determined that sum $pUPR{\geq}0.38$ could serve as a threshold for significantly increased risk of subsidence (p=0.005, area under curve=0.737, sensitivity=94%, specificity=51%). This threshold was confirmed by logistic regression analysis for subsidence (p=0.009, odds ratio=8.471). Conclusion : The UPR measurement method confirmed that UPR was correlated with subsidence. Particularly when the sum of pUPR is ${\geq}38%$, the possibility of subsidence increased.

Biomechanical analysis of pullout strength of the pedicle screws in relation to change bone mineral density (반복 하중 후 골밀도 감소에 따른 척추경 나사못의 고정력(Pullout Strength)감소 형태 분석)

  • Jung, D.Y.;Lee, S.J.;Kim, D.S.;Shin, J.W.;Kim, W.J.;Suk, S.I.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.155-156
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    • 1998
  • Screw loosening and subsequent pullout can be attributed to the reduction in bone mineral density in the vertebrae manifested by osteoporosis in which the decrease in fixation strength between the cancellous bone and screw threads are accelerated by repeated loads exerted by patients own weight and activities following the surgery. In this study, the change in pullout strength of the pedicle screws was investigated before and after repeated loads were imparted. For this purpose. Diapason pedicle screws $(6.7\times40mm)$ were inserted onto fresh porcine spine specimens (T1-L5) after bone mineral density was measured using a DEXA. With an MTS, an axial load was applied at a loading rate of 0.33mm/sec until failure to measure the maximum pullout strength. Flexion moment of 7.5N-m was then imparted at 0.5Hz for 2000 cycles. It was found that the maximum pullout strength was exponentially related to BMD regardless of load types ($107.71\;\times\;\exp^{(1.43{\times}BMD)}r^2=0.93$, P<0.0001 without repeated load; ($107.71\;\times\;\exp^{(2.19{\times}BMD)}r^2=0.78$, P<0.0001 with repeated load). The results suggest that the reduction in pullout strength for pedicle screws is far more prominent in osteoporotic spine than in normal spine especially as number of repeated load was increased. More importantly, it was demonstrated that the level of bone mineral density and the activity level of the patient should be evaluated in more detail for successful implementation of pedicle screw systems in spinal surgery.

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