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BACKGROUND:High ankle sprain is easily missed and leads to ankle dysfunction.Arthroscopy can detect hidden high ankle sprain.Suture-button elastic fixation can restore the biomechanical stability of the distal tibiofibular syndesmosis. OBJECTIVE:To explore the clinical efficacy of Suture-button elastic fixation for high ankle sprain under ankle arthroscopy. METHODS:A retrospective analysis was performed on 40 cases of high ankle sprain patients treated with Suture-button elastic fixation under ankle arthroscopy from August 2019 to August 2021 in the Department of Foot and Ankle Surgery,Wuhan Fourth Hospital.All patients underwent Suture-button elastic fixation.The American Orthopedic Foot and Ankle Society function score,Visual Analog Scale pain score,ankle range of motion,preoperative imaging data,and arthroscopic tibiofibular syndesmosis separation degree were recorded.Meislin criteria were used to evaluate the curative effect and postoperative complications were recorded. RESULTS AND CONCLUSION:(1)40 patients were followed up for 16-48 months after operation.(2)At the last follow-up,American Orthopedic Foot and Ankle Society score was(88.95±6.64 points).Visual Analog Scale score was(1.78±1.23 points).Ankle dorsiflexion range of motion was(33.50±5.79 degrees).Ankle plantarflexion range of motion was(34.50±5.97 degrees).There were statistically significant differences before and after surgery(P<0.05).(3)There was a low positive correlation between the radiographic separation index and the degree of arthroscopic separation(r=0.612,P<0.01).(4)The curative effect was evaluated by Meislin standard,with an excellent and good rate of 95%(38/40).Postoperative ankle joint pain was relieved,and ankle joint activities were significantly improved.(5)During the follow-up period,all patients had no nerve injury or incision infection.In 1 patient,the internal fixation was removed due to skin irritation and squatting sensation after operation.(6)It is concluded that Suture-button elastic fixation for high ankle sprain is effective under ankle arthroscopy in restoring ankle function and maintaining joint stability without the need for secondary removal,and it is worth clinical application.
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OBJECTIVE@#To investigate the correlation between glenohumeral joint congruence and stability in recurrent shoulder dislocations.@*METHODS@#Eighty-nine patients (89 sides) with recurrent shoulder dislocation admitted between June 2022 and June 2023 and met the selection criteria were included as study subjects. There were 36 males and 53 females with an average age of 44 years (range, 20-79 years). There were 40 cases of left shoulder and 49 cases of right shoulder. The shoulder joints dislocated 2-6 times, with an average of 3 times. The three-dimensional models of the humeral head and scapular glenoid were reconstructed using Mimics 20.0 software based on CT scanning images. The glenoid track (GT), inclusion index, chimerism index, fit index, and Hill-Sachs interval (HSI) were measured, and the degree of on/off track was judged (K value, the difference between HSI and GT). Multiple linear regression was used to analyze the correlation between the degree of on/off track (K value) and inclusion index, chimerism index, and fit index.@*RESULTS@#Multiple linear regression analysis showed that the K value had no correlation with the inclusion index ( P>0.05), and was positively correlated with the chimerism index and the fit index ( P<0.05). Regression equation was K=-24.898+35.982×inclusion index+8.280×fit index, R 2=0.084.@*CONCLUSION@#Humeral head and scapular glenoid bony area and curvature are associated with shoulder joint stability in recurrent shoulder dislocations. Increased humeral head bony area, decreased scapular glenoid bony area, increased humeral head curvature, and decreased scapular glenoid curvature are risk factors for glenohumeral joint stability.
Subject(s)
Female , Male , Humans , Adult , Shoulder Joint/diagnostic imaging , Shoulder Dislocation/diagnostic imaging , Joint Dislocations , Scapula/diagnostic imaging , ThoraxABSTRACT
The distal radioulnar joint is not only the main load-bearing joint in the wrist, but also the pivot of the rotation of the forearm. It is one of the most important and unique joints in the body. Maintaining the stability of the distal radioulnar joint is very important for our daily life. The tissue to stabilize the distal radioulnar joint includes bone structures and soft tissue structures. Although the contribution of soft tissue structures to its stability is far exceeding that of bone structures, the influence of abnormal bone structure on the distal radioulnar joint cannot be ignored. By reviewing the relevant literatures, this article divides the bone structural abnormalities into congenital and acquired bone structural abnormalities. The effects of congenital and acquiredbone structural abnormalities on the distal radioulnar joint stability are analysized and collated in this article, and its clinical symptoms, clinical grading, clinical treatments are also summerized. The problems of distal radioulnar joint instability in clinical practicing and its future researching directions are briefly described in order to provide some suggestions for future clinical applications.
Subject(s)
Humans , Forearm , Joint Instability , Rotation , Ulna , Wrist , Wrist JointABSTRACT
ABSTRACT BACKGROUND AND OBJECTIVES: Knee stability is critical for the execution of functional tasks, maintaining the joint within physiologic limits and preventing possible mechanical loads. A type of taping being increasingly used in recent years is Kinesio Taping, which is often used as resource to improve joint stability and decrease pain. This study aimed at evaluating the acute effect of Kinesio Taping on stability and pain in a patient with chronic knee instability. CASE REPORT: Male patient, 46 years old, with chronic knee instability due to late postoperative period of Anterior Cruciate Ligament injury, was evaluated during two functional activities (up/ down a stair and squat), before and immediately after Kinesio Taping. Evaluation tools were visual analog scale and videometry to evaluate knee varus angle peak during functional activities. There has been significant decrease (p<0.001) in mean knee varus angle peak during functional activities up/ down a stair (Pro-Kinesio: 189.4; Post-Kinesio: 186.2) and squat (Pre-Kinesio: 198.2; Post-Kinesio: 189.6). There has also been decrease in the visual analog scale for up/down a stair (Pre-Kinesio: 4; Post-Kinesio: 0) and squat (Pre-Kinesio: 3; Post-Kinesio: 0). CONCLUSION: Our results suggest that Kinesio Taping was effective to improve knee dynamic stability and decrease pain during functional activities of going up/down a stair and squat.
RESUMO JUSTIFICATIVA E OBJETIVOS: A estabilidade do joelho é fundamental para a execução de tarefas funcionais, mantendo a articulação dentro dos limites fisiológicos e evitando possíveis sobrecargas mecânicas. Um tipo de bandagem que vem ganhando destaque nos últimos anos é a Kinesio Taping, que é frequentemente usada como um recurso para melhorar a estabilidade articular e diminuir o quadro álgico. O objetivo deste estudo foi avaliar o efeito agudo do uso da Kinesio Taping na estabilidade e dor em paciente com instabilidade crônica de joelho. RELATO DO CASO: Paciente do sexo masculino, 46 anos, com instabilidade crônica de joelho, decorrente de pós-operatório tardio de lesão do ligamento cruzado anterior foi avaliado durante duas atividades funcionais (subida/descida no degrau e agachamento), antes e imediatamente após a Kinesio Taping. Os instrumentos de avaliação usados foram a escala analógica visual e a videometria para análise de pico do ângulo varo do joelho durante as atividades funcionais. Observou-se diminuição significativa (p<0,001) da média do pico de ângulo varo do joelho durante as atividades funcionais, subida/descida no degrau (Pré-Kinesio: 189,4; Pós-Kinesio: 186,2), e agachamento (Pré-Kinesio: 198,2; Pós-Kinesio: 189,6). Também houve diminuição da escala analógica visual, subida/descida no degrau (Pré-Kinesio: 4; Pós-Kinesio: 0) e agachamento (Pré-Kinesio: 3; Pós-Kinesio: 0). CONCLUSÃO: Os resultados do presente trabalho sugerem que a Kinesio Taping se mostrou eficaz na melhora da estabilidade dinâmica do joelho e diminuição da dor durante as atividades funcionais de subida/descida no degrau e agachamento.
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OBJECTIVE: To compare the clinical efficacy between medial collateral ligament (MCL) repair and MCL reconstruction in multi-ligament injury.
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PURPOSE: There remains uncertain whether to fix or not an ulnar styloid fracture acommpanied by distal radius fracture. Fixation might be required in cases of the fracture involving a fovea of ulnar head, an attachment site of deep triangular fibrocartilage, which is thought to be important to distal radioulnar joint stability. We analyzed a fovea involvement of an accompanied ulnar styloid fracture in patients with distal radius fracture by simple radiograph and three-dimensional computed tomography (3D CT). METHODS: We retrospectively reviewed 168 patients who underwent surgery with volar locking plate for distal radius fracture in our hospital from January 2005 to March 2015 and evaluated a fovea involvement of ulnar head by simple radiographs and 3D CT respectively, and compared. RESULTS: On simple X-ray, 64 cases (38%) were ulnar styloid fovea fractures; however, 21 cases of these revealed non-fovea fractures by 3D CT. And 7 out of 104 cases determined as non-fovea fracture by simple radiographs were diagnosed as fovea fractures by 3D CT. Sensitivity, specificity and accuracy of evaluation by simple radiograph were 86%, 82% and 83% respectively, when compared with those of 3D CT based evaluation. CONCLUSION: Accuracy of evaluating an accompanied ulnar styloid fovea fracture in patients with distal radius fracture by simple radiograph, when compared with 3D CT, was 83%; therefore, we recommend using the 3D CT based evaluation instead of simple radiograph based one for determination of fovea involvement of ulnar head.
Subject(s)
Humans , Head , Joints , Radiography , Radius Fractures , Retrospective Studies , Sensitivity and Specificity , Triangular FibrocartilageABSTRACT
PURPOSE: The purpose of this study was to investigate screw joint stability and sagittal fit between internal connection implant fixtures of two different manufacturers and customized abutments. MATERIALS AND METHODS: Internal connection implant systems from two different manufacturers (Biomet 3i system, Astra Tech system) were selected for this study (n=24 for each implant system, total n=48). For 3i implant system, half of the implants were connected with Ti ready-made abutments and the other half implants were connected with Ti CAD-CAM custom ones of domestic-make (Myplant, Raphabio Co., Seoul, Korea) and were classified into Group 1 and Group 2 respectively. Astra implants were divided into Group 3 and Group 4 in the same way. Micro-CT sagittal imaging was performed for fit analysis of interfaces and preloading reverse torque values (RTV) were measured. RESULTS: In the contact length of fixture-abutment interface, there were no significant differences not only between Group 1 and Group 2 but also between Group 3 and Group 4 (Mann-Whitney test, P>.05). However, Group 2 and Group 4 showed higher contact length significantly than Group 1 and Group 3 in abutmentscrew interface as well as fixture-screw one (Mann-Whitney test, P<.05). In addition, RTV was lower in CAD-CAM custom abutments compared to ready-made ones (Student t-test, P<.05). CONCLUSION: It is considered that domestically manufactured CAD-CAM custom abutments have similar fit at the fixture abutment interface and it could be used clinically. However, RTV of CAD-CAM custom abutments should be improved for the increase of clinical application.
Subject(s)
Computer-Aided Design , Joints , Seoul , TorqueABSTRACT
Introducción: El objetivo de este estudio retrospectivo fue observar el comportamiento de un tallo modular de fijación proximal y anclaje distal en revisiones de cadera con defectos femorales II y IIIA (Paprosky), evaluando la estabilidad protésica y articular, la restauración del offset y la diferencia de longitud. Materiales y Métodos: Se analizaron 22 revisiones de reemplazos totales de cadera. Doce mujeres y 10 hombres (edad promedio 62.38 años). El seguimiento promedio fue de 62 meses. El tallo femoral utilizado fue S-ROM® (Depuy, Johnson & Johnson). Los defectos óseos femorales fueron 15 de tipo II y 7 de tipo IIIA de Paprosky. Para la evaluación clínica se utilizó el puntaje de cadera de Harris. En las radiografías, se analizó el comportamiento del tallo, su integración, la diferencia de longitud y el offset femoral, y se consideró correcta una diferencia <5 mm. Resultados: El offset fue restaurado en 16 (72,3%) casos y la longitud de miembros se restauró en 15 (68,2%). Hubo un solo hundimiento del tallo, y de acuerdo con la clasificación de Engh, se observaron 17 (77,27%) uniones óseas. Se produjeron siete (31,8%) complicaciones, dos luxaciones que requirieron revisión, cuatro fracturas intraoperatorias y una paresia de ciático poplíteo externo. Conclusiones: Este tallo impresiona ser una alternativa válida para resolver un problema complejo. Por su versatilidad, permite resolver mecánicamente el defecto óseo, devuelve la longitud al miembro y el offset a la articulación, con un índice de complicaciones aceptables.
Background: The purpose of this retrospective analysis was to observe the outcomes of a modular hip system in revision total hip arthroplasty with Paprosky types II and IIIA femoral bone defects, evaluating their performance, offset restoration and leg length discrepancy correction. Methods: Twenty-two revision total hip arthroplasties were analyzed in 12 women and 10 men (average age 62.38 years). The average follow-up was 62 months. Femoral stems S-ROM® (Depuy, Johnson & Johnson) were used. Paprosky femoral bone deficit were 15 types II and 7 IIIA. Clinical evaluation was performed using the Harris Hip Score, while Engh lassification was used for stem fixation. Offset restoration, leg length discrepancy (a difference <5 mm was considered correct) and hip stability were evaluated radiographically. Results: Offset was properly restored in 16 (72.3%) cases and the leg length was matched in 15 (68.2%). There was a single stem subsidence and according to Engh classification, proximal bone ingrowth fixation was obtained in 17 (77.27%) patients. There were 7 (31.8%) complications: two dislocations that required revision, four intraoperative fractures and a lateral popliteal nerve paresis. Conclusions: S-ROM® modular system seems to be a valid alternative to solve a complex problem. Its versatility allows to optimize hip stability, leg length equalization and offset restoration in revision total hip arthroplasty, showing an acceptable complication rate.
Subject(s)
Adult , Middle Aged , Arthroplasty, Replacement, Hip/adverse effects , Leg Length Inequality , Retrospective Studies , Follow-Up Studies , ReoperationABSTRACT
Objective To investigate the effect of running exercise on cartilage in rats with an unstable knee joint.Methods Twenty 8-week-old Sprague-Dawley rats had their left anterior cruciate ligament cut to model an unstable knee.They were randomly divided into a control group and an experimental group,10 rats in each group.The control group was given no intervention,while the experimental group accepted running exercise training on na animal treadmill at a velocity of 15 m/min for an hour every day.After 3 and 6 weeks of training,5 rats were sacrificed and cartilage from the medial condyle of the femur was sampled,decalcificated,embedded and sliced on the sagittal plane.After hematoxylin-eosin staining,toluidine blue staining and immunohistochemical staining,the cartilage thickness,Mankin' score,the content of matrix collagen and the proteoglycan content of the cartilage matrix were assessed,and the shape and structure of the unstable knee joints were observed under a transmission electron microscope.Results The cartilage thicknesses and Mankin's scores at 6 weeks were significantly different from those at 3 weeks in both groups.In the experimental group the average thickness of cartilage was 154 ± 13 μm at 3 weeks and 131 ± 15 μm at 6 weeks.The corresponding Mankin's scores were 9.93 ± 1.36 and 11.23 ± 1.57,respectively.Both were significantly different from the control group averages at the same time points.There was also a significant difference in the positive rate of toluidine blue and collagen type Ⅱ staining between the experimental group and the control group at both time points,and in the experimental group between 3 and 6 weeks of training.After 3 weeks of training,fewer chondrocytes were observed under the transmission electron microscope in the experimental group,and fissures were seen on the surface of the cartilages.However,3 weeks later,quite a few ruptures and a lot of necrotic cells could be seen.Conclusions Running exercise can damage the cartilage of unstable knee joints and speed up the development of osteoarthritis.Even moderate exercise could aggravate damage to unstable joints and the cartilage matrix,and accelerate chondrocyte degeneration.
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PURPOSE: The purpose of this study was to investigate the fit and screw joint stability between Ready-made abutment and CAD-CAM custom-made abutment. MATERIALS AND METHODS: Osstem implant system was used. Ready-made abutment (Transfer abutment, Osstem Implant Co. Ltd, Busan, Korea), CAD-CAM custom-made abutment (CustomFit abutment, Osstem Implant Co. Ltd, Busan, Korea) and domestically manufactured CAD-CAM custom-made abutment (Myplant, Raphabio Co., Seoul, Korea) were fabricated five each and screws were provided by each company. Fixture and abutments were tightening with 30Ncm according to the manufacturer's instruction and then preloding reverse torque values were measured 3 times repeatedly. Kruskal-Wallis test was used for statistical analysis of the preloading reverse torque values (alpha=.05). After specimens were embedded into epoxy resin, wet cutting and polishing was performed and FE-SEM imaging was performed, on the contact interface. RESULTS: The pre-loading reverse torque values were 26.0 +/- 0.30 Ncm (ready-made abutment; Transfer abutment) and 26.3 +/- 0.32 Ncm (CAD-CAM custom-made abutment; CustomFit abutment) and 24.7 +/- 0.67 Ncm (CAD-CAM custom-made abutment; Myplant). The domestically manufactured CAD-CAM custom-made abutment (Myplant abutment) presented lower pre-loading reverse torque value with statistically significant difference than that of the ready-made abutment (Transfer abutment) and CAD-CAM custom-made abutment (CustomFit abutment) manufactured from the same company (P=.027) and showed marginal gap in the fixture-abutment interface. CONCLUSION: Within the limitation of the present in-vitro study, in domestically manufactured CAD-CAM custom-made abutment (Myplant abutment) showed lower screw joint stability and fitness between fixture and abutment.
Subject(s)
Computer-Aided Design , TorqueABSTRACT
PURPOSE: The purpose of this study was to evaluate the effect of abutment material on screw-loosening before and after cyclic loading. Among the different materials of abutments, zirconia and metal abutment were used. MATERIAL AND METHODS:: Two types of implant systems: external butt joint (US II, Osstem Implant, Korea) and internal conical joint (GS II, Osstem Implant, Korea) were used. In each type, specimens were divided into two different kinds of abutments: zirconia and metal (n = 5). The implant was rigidly held in a special holding to device ensure fixation. Abutment was connected to 30 Ncm with digital torque gauge, and was retightened in 30 Ncm after 10 minutes. The initial removal torque values were measured. The same specimens were tightened in 30 Ncm again and held in the cycling loading simulator (Instron, USA) according to ISO/FPIS 1480. Cycling loading tests were performed at loads 10 to 250 N, for 1 million cycles, at 14 Hz, (by subjecting sinusoidal wave from 10 to 250 N at a frequency of 14 Hz for 1 million cycles,) and then postload removal torque values were evaluated. RESULTS: 1. In all samples, the removal values of abutment screw were lower than tightening torque values (30 Ncm), but the phenomenon of the screw loosening was not observed. 2. In both of the implant systems, initial and postload removal torque of zirconia abutment were significantly higher than those of metal abutment (P .05). 4. In metal abutments, the removal torque ratio of GS II system (internal conical joint system) was lower than that of US II system (external butt joint system) (P .05). CONCLUSION: Zirconia abutment had a good screw joint stability in the condition of one million cycling loading.
Subject(s)
Dietary Sucrose , Joints , Torque , ZirconiumABSTRACT
STATEMENT OF PROBLEM: Loosening or fracture of the abutment screw is one of the common problems related to the dental implant. Generally, in order to make the screw joint stable, the preload generated by tightening torque needs to be increased within the elastic limit of the screw. However, additional tensile forces can produce the plastic deformation of abutment screw when functional loads are superimposed on preload stresses, and they can elicit loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum tightening torque that maximizes a fatigue life and simultaneously offer a reasonable degree of protection against loosening. PURPOSE: The purpose of this study was to present the influence of tightening torque on the implant-abutment screw joint stability with the 3 dimensional finite element analysis. MATERIAL AND METHODS: In this study, the finite element model of the implant system with external butt joint connection was designed and verified by comparison with additional theoretical and experimental results. Four different amount of tightening torques (10, 20, 30 and 40 Ncm) and the external loading (250 N, 30degrees C) were applied to the model, and the equivalent stress distributions and the gap distances were calculated according to each tightening torque and the result was analyzed. RESULTS: Within the limitation of this study, the following results were drawn; 1) There was the proportional relation between the tightening torque and the preload. 2) In case of applying only the tightening torque, the maximum stress was found at the screw neck. 3) The maximum stress was also shown at the screw neck under the external loading condition. However in case of applying 10 Ncm tightening torque, it was found at the undersurface of the screw head. 4) The joint opening was observed under the external loading in case of applying 10 Ncm and 20 Ncm of tightening torque. 5) When the tightening torque was applied at 40 Ncm, under the external loading the maximum stress exceeded the allowable stress value of the titanium alloy. CONCLUSION: Implant abutment screw must have a proper tightening torque that will be able to maintain joint stability of fixture and abutment.
Subject(s)
Alloys , Dental Implants , Fatigue , Finite Element Analysis , Head , Joints , Neck , Plastics , Titanium , TorqueABSTRACT
STATEMENT OF PROBLEM: Within the elastic limit of the screw, the greater the preload, the tighter and more secure the screw joint. However, additional tensile forces can incur plastic deformation of the abutment screw when functional loads are superimposed on preload stresses, and they can elicit the loosening or fracture of the abutment screw. Therefore, it is necessary to find the optimum preload that will maximize fatigue life and simultaneously offer a reasonable degree of protection against loosening. Another critical factor in addition to the applied torque which can affect the amount of preload is the joint connection type between implant and abutment. PURPOSE: The purpose of this study was to evaluate the influence of tightening torque on the implant-abutment screw joint stability. MATERIAL AND METHODS: Respectively, three different amount of tightening torque (20, 30, and 40 Ncm) were applied to implant systems with three different joint connections, one external butt joint and two internal cones. The initial removal torque value and the postload (cyclic loading up to 100,000 cycles) removal torque value of the abutment screw were measured with digital torque gauge. Then rate of the initial and the postload removal torque loss were calculated for the comparison of the effect of tightening torques and joint connection types between implant and abutment on the joint stability. Results and CONCLUSION: 1. Increase in tightening torque value resulted in significant increase in initial and postload removal torque value in all implant systems (P .05), however GS II and US II systems exhibited significantly lower loss rates with 40 Ncm torque value than with 20 Ncm (P .05).
Subject(s)
Fatigue , Joints , Plastics , TorqueABSTRACT
STATEMENT OF PROBLEM: A few dry lubricants were applied to abutment screws for the improvement of joint stability. PURPOSE: The purpose of this study was to evaluate the surface change and fit of TiNCoated abutment screw through the examination of tested screws in the field emission scanning electron microscope(FE-SEM;Netherland, Phillips co., model:XL 30 SFEG) after repeated closing and opening. MATERIALS AND METHOD: Titanium(3i/implant Innovations Inc, USA) and Gold-Tite abutment screws(3i/implant Innovations Inc, USA) were selected for Group A and C respectively. TiN coated titanium abutment screws were also divided into two groups, Group B and D. Abutment screws of each group and the fit of abutment screw/implant fixture/abutment were observed on FE-SEM after repeated closing and opening test respectively. RESULTS: 1. The abutment screws of TiN coated groups(Group B and D) showed more remarkable wear resistance in the threads of the screw than those of the other group(Group A and C). 2. There were more severe wear and defect of TiN coating in Group D tightened to 32 Ncm than Group B to 20 Ncm. 3. There was no difference in the fit of abutment screw/fixture/abutment among four groups, Group A, Group B, Group C and Group D. CONCLUSION: Under the conditions of this study, it is suggested that TiN coating of abutment screw be clinically acceptable and be expected to reduce the risk of abutment screw loosening. TiN coating of abutment screw showed good resistance against wear and the adequate fit of abutment screw/implant fixture/abutment.
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Joints , Lubricants , Tin , TitaniumABSTRACT
STATEMENT OF PROBLEM: Little is known about the effect of abutment preparation procedure on de-torque values in different implant platform and the relationship of final de-torque values with different implant platform size. PURPOSE: This study evaluated the effect of abutment preparation procedure on de-torque values in different implant platform and the relationship of final de-torque values with different implant platform size. MATERIAL AND METHOD: Six ITI implants (2 narrow-neck implants, 2 regular-neck implants, 2 wide-neck implants) and six Bra.nemark implants (2 narrow platforms, 2 regular platforms, 2 wide platforms) were embedded in each acrylic resin block with epoxy resin. Eighteen synOcta(R) abutments (6 narrow-neck implant-abutments, 6 regular-neck implant-abutments, 6 wide-neck implant-abutments) and eighteen esthetic abutments (6 narrow platform-abutments, 6 regular platform-abutments, 6 wide platform-abutments) were tightened to each implant with digital torque gauge. Initial de-torque values were measured using digital torque gauge. After preparation of abutments, Final de-torque values were measured with digital torque gauge. RESULTS AND CONCLUSION: 1. Screws loosening or abutments motion were not detected in all experimental group, but some scratches of implant-abutment joints were detected in all group. 2. Reduction ratios of final de-torque values were greater than initial de-torque values in all measured group, except in narrow-neck implant-abutment group (p<0.05). 3. Reduction ratios of final de-torque values in wide-neck implant-abutment group were greater than regular-neck implant-abutment group (p<0.01). 4. The greatest standard deviation value was detected in wide platform group in both implant systems.
Subject(s)
Joints , TorqueABSTRACT
STATEMENT OF PROBLEM: Repeated delivery and removal of abutment cause some changes such as wear, scratch or defect of hexagonal structure. It may increase the value of rotational freedom(RF) between hexagonal structures. PURPOSE: The purpose of this study was to evaluate surface changes and rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment after repeated delivery and removal under SEM and toolmaker's microscope. MATERIALS AND METHODS: Implant systems used for this study were 3i and Avana. Seven pairs of implant fixture, abutment and abutment screws for each system were selected and all fixtures were perpendicularly mounted in liquid unsaturated polyesther with dental surveyor. Each one was embedded beneath the platform of fixture. Surfaces of hexagonal structure before repeated closing and opening of abutment were observed using SEM and rotational freedom was measured by using toolmaker's microscope. Each abutment was secured to the implant fixture by each abutment screw with recommended torque value using a digital torque controller and was repeatedly delivered and removed by 20 times respectively. After experiment, evaluation for the change of hexagonal structures and measurement of rotational freedom were performed. RESULT: The results were as follows ; 1. Wear of contact area between implant fixture and abutment was considerable in both 3i and Avana system. Scratches and defects were frequently observed at the line-angle of hexagonal structures of implant fixture and abutment. 2. In the SEM view of the external hexagon of implant fixture, the point-angle areas at the corner edge of hexagon were severely worn out in both systems. It was more notable in the case of 3i systems than in that of Avana systems. 3. In the SEM view of the internal hexagon of abutment, Gingi-Hue abutment of 3i systems showed severe wear in micro-stop contacts that were machined into the corners to prevent rotation and cemented abutment of Avana systems showed wear in both surface area adjacent to the corner mating with external hexagon of implant fixture. 4. The mean values of rotational freedom between the external hexagon of the implant fixture and internal hexagon of abutment were 0.48+/-0.04 degrees in pre-tested 3i systems and 1.18+/-0.25 degrees after test, and 1.80+/-0.04 degrees in pre-tested Avana systems and 2.61+/-0.16 degrees after test. 5. Changes of rotational freedom after test showed statistically a significant increase in both 3i and Avana systems(p0.05, unpaired t-test). CONCLUSION: Conclusively, it was considered that repeated delivery and remove of abutment by 20 times would not have influence on screw joint stability. However, it caused statistically the significant change of rotational freedom in tested systems. Therefore, it is suggested that repeated delivery and remove of abutment should be minimal as possible as it could be and be done carefully. Additionally, it is suggested that the means or treatment to prevent the wear of mating components should be devised.
Subject(s)
Freedom , Joints , TorqueABSTRACT
Traditionally, evaluation after ACL reconstruction has been focused on physical characteristics and measures of knee stability. Recently, however, reliance on such criteria has been refuted based on the lack of a strong relationship between these measures and both the patient s perception of knee function and return to sports activity. In present study, preoperative and postoperative physical examinations, isokinetic dynamometer, arthrometer test and functional tests were performed on 17 patients with chronic anterior cruciate ligament tears treated by arthroscopic reconstruction using autogenous bone-patellar tendon-bone graft with at least 1 year of follow-up. Muscle power, joint stability and functional recovery were checked for functional evaluation by specific methods. Lysholm score rating scale and functional tests (single leg hop test, vertical jump test, timed single jump test) were performed preoperatively and 6, 12 months postoperatively. Pivot-shift test, Lachman test, anterior drawer test, thigh circumference index and Cybex II+ isokinetic dynamometer test were done preoperatively and at 3, 6, 12 months postoperatively. KT-2000 arthrometer test was done at last follow-up. Lysholm score has showed increasing tendency at 6, 12 months postoperatively (p < 0.01). In Cybex study, deficit percentage of peak torque and total work of the quadriceps and hamstrings was same or slightly decreased at 3, 6 months, but have decreased at 1 year follow-up (p < 0.01). Functional tests and physical examinations have also showed improving tendency at 12 months (p < 0.01). Arthrometer test revealed no significant laxity of the knee joint at last follow-up. In conclusion, muscle strengh and functional capacity in ACL reconstructed knee showed significant improvement at postoperative one year compared with preoperative status. It was considered that arthroscopic reconstruction using autogenous bone-patellar tendon-bone graft is one of the useful method for chronic anterior cruciate ligament injury.