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1.
Artigo em Inglês | MEDLINE | ID: mdl-34200143

RESUMO

The aim of this human cadaver study was to assess the accuracy of zygomatic/pterygoid implant placement using custom-made bone-supported laser sintered titanium templates. For this purpose, pre-surgical planning was done on computed tomography scans of each cadaver. Surgical guides were printed using direct metal laser sintering technology. Four zygomatic and two pterygoid implants were inserted in each case using the guided protocol and related tools. Post-operative computed tomography (CT) scans were obtained to evaluate deviations between the planned and inserted implants. Accuracy was measured by overlaying the real position in the post-operative CT on the virtual presurgical placement of the implant in a CT image. Descriptive and bivariate analyses of the data were performed. As a result, a total of 40 zygomatic and 20 pterygoid implants were inserted in 10 cadavers. The mean deviations between the planned and the placed zygomatic and pterygoid implants were respectively (mean ± SD): 1.69° ± 1.12° and 4.15° ± 3.53° for angular deviation. Linear distance deviations: 0.93 mm ± 1.23 mm and 1.35 mm ± 1.45 mm at platform depth, 1.35 mm ± 0.78 mm and 1.81 mm ± 1.47 mm at apical plane, 1.07 mm ± 1.47 mm and 1.22 mm ± 1.44 mm for apical depth. In conclusion, the surgical guide system showed accuracy for all the variables studied and allowed acceptable and accurate implant placement regardless of the case complexity.


Assuntos
Cirurgia Assistida por Computador , Cadáver , Desenho Assistido por Computador , Humanos , Próteses e Implantes , Tomografia Computadorizada por Raios X
2.
Sud Med Ekspert ; 64(4): 25-29, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34264577

RESUMO

OBJECTIVE: Determination of the personality factors influence (gender, age, death category) on the numerical indicators of electrical characteristics during biophysical objectification of soft tissue injuries in a putrefactive corpse. The study was carried out based on Bureau of Forensic Medicine of the Bashkortostan Republic. The instrumental method examined 177 putrefactive corpses; 78 are female and 99 are male. Measurement of electrical characteristics (electrical capacity, electrical resistance) was carried out by an invasive method using a submersible sensor. It was established a significant effect of a person's age, gender and death category on the results of instrumental measurements. These individual characteristics can be recognized as factors that determine the electrical resistance and electrical capacity of biological tissues.


Assuntos
Mudanças Depois da Morte , Lesões dos Tecidos Moles , Cadáver , Feminino , Medicina Legal , Humanos , Masculino , Personalidade
3.
Sud Med Ekspert ; 64(4): 30-36, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34264578

RESUMO

According to specialized literature and the results of our own experiments to carry out a comprehensive study to find criteria for determining the time of death in the late postmortem period. It turned out that a combined assessment of microbiological, entomological and biophysical data obtained in the study of a corpse is advisable for medical diagnostics of the duration of the postmortem interval, which does not exclude the need to compare them with the results obtained by traditional morphological methods. From an applied point of view, it is very important to «standardize¼ the conditions of such studies. For an in-depth study of the nature of cause-and-effect relationships of phenomena occurring in biological tissues in the late postmortem period, it is very interesting to perform microbiological, entomological and biophysical studies under different environmental conditions, but according to a single program and on a single methodological basis.


Assuntos
Medicina Legal , Mudanças Depois da Morte , Autopsia , Cadáver , Entomologia , Humanos
4.
Sud Med Ekspert ; 64(4): 42-46, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34264580

RESUMO

OBJECTIVE: The aim of the study was to statistically study the age-related microstructure of the fifth metatarsal bone (VPC) and to develop the diagnostic models using step-by-step discriminant and regression analyses. The primary materials of Yu.V. Zazulin on the microstructure of the VPC of the left foot from the corpses of both sexes persons (male - 60, female - 40) aged from 18 to 90 years from the archive of the RCSE were used. The individual data is compiled in the form of a computer database and analyzed using the software package Statistica 10. According to the discriminant analysis the diagnostic models were calculated that distinguish between age groups: 18-49 years and 50-90 years with an accuracy 90.43% of correct classification; 18-35 and 36-49 years with 94.12% accuracy; 50-61 and 62-90 years with 80.96% accuracy. Using regression analysis the diagnostic models were calculated in the range: 18-90 years, 18-49 years, 50-90 years with diagnostic accuracy from ±9.47 years to ±3.40 years. Based on the results of verification the models dedicated for isolated and complex usage in forensic practice.


Assuntos
Ossos do Metatarso , Adolescente , Adulto , Cadáver , Feminino , , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
J Korean Med Sci ; 36(26): e188, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34227264

RESUMO

The rapid increase of the coronavirus disease 2019 pandemic from mid-February 2020 has led the anatomy department of the Korea University College of Medicine to cease the dissection laboratory. However, the hands-on anatomy laboratory experience is paramount to maximizing learning outcomes. In this paper, we share the experiences and lessons learned through the face-to-face cadaveric dissection experience during this disruptive situation. To minimize infection risks, the following strategies were applied: first, students' on-campus attendance was reduced; second, body temperatures and symptoms were checked before entering the laboratory, and personal protective equipment was provided to all participants; and third, a negative pressure air circulation system was used in the dissection room. We suggest that conducting face-to-face cadaveric anatomy dissection is feasible when the daily count of newly infected cases stabilizes, and there is ample provision of safety measures to facilitate hands-on education.


Assuntos
Anatomia/educação , COVID-19/patologia , COVID-19/prevenção & controle , Dissecação/métodos , Equipamento de Proteção Individual , Cadáver , Educação à Distância/métodos , Humanos , República da Coreia , SARS-CoV-2 , Faculdades de Medicina , Estudantes de Medicina
6.
J Spec Oper Med ; 21(2): 98-99, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34105131

RESUMO

Human brucellosis can be caused by different Brucella spp. When conducting operations in a country with high rates of brucellosis, extra precautions should be taken. Appropriate personal protective measures should be used in situations when close contact with animal carcasses cannot be avoided. Clinical diagnosis, treatment, and prevention are discussed.


Assuntos
Brucella , Brucelose , Animais , Brucelose/diagnóstico , Brucelose/terapia , Cadáver , Humanos
8.
BMC Musculoskelet Disord ; 22(1): 558, 2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34144675

RESUMO

BACKGROUND: Inversion ankle sprains, or lateral ankle sprains, often result in symptomatic lateral ankle instability, and some patients need lateral ankle ligament reconstruction to reduce pain, improve function, and prevent subsequent injuries. Although anatomically reconstructed ligaments should behave in a biomechanically normal manner, previous studies have not measured the strain patterns of the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) after anatomical reconstruction. This study aimed to measure the strain patterns of normal and reconstructed ATFL and CFLs using the miniaturization ligament performance probe (MLPP) system. METHODS: The MLPP was sutured into the ligamentous bands of the ATFLs and CTLs of three freshly frozen cadaveric lower-extremity specimens. Each ankle was manually moved from 15° dorsiflexion to 30° plantar flexion, and a 1.2-N m force was applied to the ankle and subtalar joint complex. RESULTS: The normal and reconstructed ATFLs exhibited maximal strain (100) during supination in three-dimensional motion. Although the normal ATFLs were not strained during pronation, the reconstructed ATFLs demonstrated relative strain values of 16-36. During the axial motion, the normal ATFLs started to gradually tense at 0° plantar flexion, with the strain increasing as the plantar flexion angle increased, to a maximal value (100) at 30° plantar flexion; the reconstructed ATFLs showed similar strain patterns. Further, the normal CFLs exhibited maximal strain (100) during plantar flexion-abduction and relative strain values of 30-52 during dorsiflexion in three-dimensional motion. The reconstructed CFLs exhibited the most strain during dorsiflexion-adduction and demonstrated relative strain values of 29-62 during plantar flexion-abduction. During the axial motion, the normal CFLs started to gradually tense at 20° plantar flexion and 5° dorsiflexion. CONCLUSION: Our results showed that the strain patterns of reconstructed ATFLs and CFLs are not similar to those of normal ATFLs and CFLs.


Assuntos
Instabilidade Articular , Ligamentos Laterais do Tornozelo , Articulação do Tornozelo/cirurgia , Fenômenos Biomecânicos , Cadáver , Humanos , Ligamentos Laterais do Tornozelo/cirurgia , Tendões/cirurgia
9.
BMC Musculoskelet Disord ; 22(1): 590, 2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34174846

RESUMO

AIM: The treatment of tibial fractures with an intramedullary nail is an established procedure. However, torsional control remains challenging using intraoperatively diagnostic tools. Radiographic tools such as the Cortical Step Sign (CSS) and the Diameter Difference Sign (DDS) may serve as tools for diagnosing a relevant malrotation. The aim of this study was to investigate the effect of torsional malalignment on CSS and DDS parameters and to construct a prognostic model to detect malalignment. METHODS: A proximal tibial shaft fracture was set in human tibiae. Torsion was set stepwise from 0° to 30° in external and internal torsion. Images were obtained with a C-arm and transferred to a PC for measuring the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD) in AP and the anterior cortical thickness (ACT) as well as the posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and the distal main fragment. RESULTS: There were significant differences between the various degrees of torsion for each of the absolute values of the examined variables. The parameters with the highest correlation were TD, LCT and ACT. A model combining ACT, LCT, PCT and TD lateral was most suitable model in identifying torsional malalignment. The best prediction of clinically relevant torsional malalignment, namely 15°, was obtained with the TD and the ACT. CONCLUSION: This study shows that the CSS and DDS are useful tools for the intraoperative detection of torsional malalignment in proximal tibial shaft fractures and should be used to prevent maltorsion.


Assuntos
Mau Alinhamento Ósseo , Fixação Intramedular de Fraturas , Fraturas da Tíbia , Pinos Ortopédicos , Cadáver , Diáfises , Humanos
10.
J Surg Orthop Adv ; 30(2): 78-81, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34181521

RESUMO

The purpose of this study was to identify the ideal start site for a retrograde intramedullary fibular cortical screw based on its relationship to the surrounding soft tissue structures and to assess for damage to the surrounding soft tissue structures caused during placement of the screw. Four fresh frozen cadavers underwent fluoroscopic placement of a 3.5 mm cortical screw utilizing a standardized protocol. No damage to the peroneal tendons were noted in any cadaver with the foot in an inverted and plantarflexed position. The closest structure to the center of the screw head was the anterior talofibular ligament anteriorly (3.33 mm range: 3-4 mm) and the calcaneofibular ligament posteriorly (2.66 mm, range: 2-3 mm). Two screws violated the malleolar fossa medially and were noted to impinge on the lateral process of the talus. The ideal start site for a 3.5 mm intramedullary fibular screw is at the midline on the lateral radiograph and 3.0 mm lateral to the malleolar fossa on the AP radiograph. This avoids damage to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) and prevents impingement on the lateral process of the talus. (Journal of Surgical Orthopaedic Advances 30(2):078-081, 2021).


Assuntos
Instabilidade Articular , Ligamentos Laterais do Tornozelo , Tálus , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Parafusos Ósseos , Cadáver , Fíbula/cirurgia , Humanos , Tálus/diagnóstico por imagem , Tálus/cirurgia
11.
J Surg Orthop Adv ; 30(2): 112-115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34181529

RESUMO

Physical examination education begins early for medical learners. A hindrance to physical exam competency is lack of exposure to pathology in standardized patient settings. This research focuses on improving medical education through the utilization of cadavers that have undergone a soft-embalming technique: the Thiel method. Three scenarios were created in four Thiel cadavers: anterior cruciate ligament (ACL) tear, posterior cruciate ligament (PCL) tear, and sham incision. Students were asked to diagnose ACL tears using the Lachman exam. A total of 54 learners participated in the study. Post-surveys indicated most learners: (1) prefer to use standardized patients (SPs) and soft-embalmed cadavers in their physical examination courses, (2) increased their confidence in performing the Lachman exam on real patients, and (3) enhanced their Lachman technique. SPs ultimately cannot volitionally reproduce the physical exam findings of ACL deficiency. Consequently, learners cannot accurately identify positive versus negative examination findings. Thiel-embalmed cadavers are a valuable resource for physical examination education. (Journal of Surgical Orthopaedic Advances 30(2):112-115, 2021).


Assuntos
Lesões do Ligamento Cruzado Anterior , Embalsamamento , Lesões do Ligamento Cruzado Anterior/diagnóstico , Cadáver , Humanos , Exame Físico , Inquéritos e Questionários
13.
Acta Cir Bras ; 36(5): e360506, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161433

RESUMO

PURPOSE: To evaluate the biomechanical properties of a novel total hip replacement femoral stem. METHODS: Eight pairs of femurs from dog cadavers were used. The femurs were separated into different groups. A novel femoral stem with a convex proximal portion (Stem B) was biomechanically evaluated and compared to awell-known veterinary collared stem (Stem A). Femoral stems were inserted into the contralateral femurs from the same dog, forming 16 constructs. A flexo-compression load was applied on the axial axis of each sample. Maximum strength, deflection, stiffness, and energy absorption were analysed. RESULTS: Group B constructs showed significantly higher values (p ? 0.05) for the variables, except stiffness. The mean maximum strength was 1,347 ± 357 N for Group A and 1,805 ± 123 N for Group B (p ? 0.0069). The mean deflection was5.54 ± 2.63 mm for Group A and 10.03 ± 3.99 mm for Group B (p ? 0.0056). For the energy variable, the force was 6,203 ± 3,488 N/mm for Group A and 12,885 ± 5,056 N/mm for Group B (p ? 0.0054). Stem B had greater maximum strength, deflection, and energy. CONCLUSIONS: The new stem was effective in neutralizing the impact of axial flexion-compression stresses during biomechanical tests in cadaveric models.


Assuntos
Artroplastia de Quadril , Animais , Fenômenos Biomecânicos , Cadáver , Cães , Fêmur/cirurgia , Pressão
14.
J Clin Neurosci ; 89: 226-231, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34119272

RESUMO

We describe the anatomical landmarks and surgical feasibility of a novel 'safe' brainstem entry zone to approach ventrally placed intra-axial midbrain tumors. The anatomy of the brainstem was specifically studied to evaluate safe surgical entry zone in the midbrain on two formalin fixed silicon injected cadaver head specimens. A novel entry point through the lateral one - fifth of the cerebral peduncle was identified to be 'safe' to approach lesions of the ventral midbrain. Three patients, having oculomotor schwannoma, peduncular glioma and a peduncular cavernoma were operated using this safe entry zone. To approach the midbrain, retrosigmoid lateral supracerebellar route was used in two patients and a basal subtemporal avenue was deployed in one patient. On the basis of fine microanatomical dissection on cadavers, a novel entry point through the lateral one-fifth of the cerebral peduncle, 5 mm anterior to the lateral mesencephalic sulcus and approximately 5 mm superior to the fourth nerve was identified. The proposed brainstem entry point traverses the parieto-temporo-occipital pontine fibers and the trajectory is between the corticospinal tracts ventrally and the substantia nigra dorsally. Three patients were operated successfully using the approach. There were no post-operative motor, sensory or extra-pyramidal deficits. The corridor through the lateral one-fifth of the cerebral peduncle presents a safe and relative 'easy' surgical route to approach ventrally placed intra-axial midbrain tumors.


Assuntos
Neoplasias do Tronco Encefálico/diagnóstico por imagem , Neoplasias do Tronco Encefálico/cirurgia , Pedúnculo Cerebral/diagnóstico por imagem , Pedúnculo Cerebral/cirurgia , Craniotomia/métodos , Microcirurgia/métodos , Adulto , Cadáver , Feminino , Humanos , Masculino , Adulto Jovem
15.
Rev Esp Patol ; 54(3): 165-168, 2021.
Artigo em Espanhol | MEDLINE | ID: mdl-34175027

RESUMO

The difficulties involved in performing autopsies of patients who had died due to COVID-19 required the use of alternative methods in order to obtain tissue samples of affected organs. We describe the technique of core needle aspiration, without ultrasonographic guidance, which we used in 19 cadavers and which produced a high yield in lungs, heart (>94%) and liver (>89%), thus enabling the study of the morphological changes produced by SARS-CoV-2.


Assuntos
Biópsia com Agulha de Grande Calibre/métodos , COVID-19/patologia , Biópsia com Agulha de Grande Calibre/instrumentação , Encéfalo/patologia , COVID-19/prevenção & controle , Cadáver , Humanos , Rim/patologia , Fígado/patologia , Pulmão/patologia , Miocárdio/patologia , Baço/patologia
16.
Injury ; 52 Suppl 3: S84-S88, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34088466

RESUMO

INTRODUCTION: In surgically treated rotational malleolar fractures, residual syndesmotic instability is typically assessed following fixation with the widely used intraoperative Cotton test. However, due to its dynamic nature, there are inconsistencies of the magnitude and direction of the distraction force when attempting to pull the fibula away from the tibia using a bone hook. The novel Tap test advances a cortical tap through a drilled hole in the fibula with a stable, unidirectional distraction force applied to the tibia. The objective of this cadaveric study was to compare the Cotton and Tap tests as diagnostic tools for coronal plane syndesmotic instability. METHODS: Tibiofibular Clear Space (TFCS) of 10 cadaveric specimens was measured for: intact, non-stressed; intact, stressed; injured, non-stressed; and injured, stressed (Tap and Cotton tests). In injured conditions, the syndesmotic ligamentous complex was sectioned using an anterolateral longitudinal approach. Perfect fluoroscopic Mortise images were acquired for all conditions. Two independent and blinded Orthopaedic Foot and Ankle Surgeons measured TFCS 1 cm proximal to the ankle joint line. Intra and interobserver reliabilities were assessed by Intraclass Correlation Coefficient. Syndesmotic TFCS values for all conditions were compared by paired Wilcoxon. Diagnostic performance of the Cotton and Tap tests was assessed using a relative increase of TFCS > 2 mm when comparing intact stressed and injured stressed conditions. P-values <0.05 were considered significant. RESULTS: The intraclass correlation coefficient for intraobserver and interobserver reliability was respectively 0.96 and 0.79. TFCS measurements were similar in intact non-stressed, intact stressed (both Cotton and Tap tests) and injured non-stressed conditions, with mean values and 95% Confidence Intervals of: intact non-stressed, 3.5 mm; intact stressed, 3.6 mm (Cotton test) and 4.0 mm (Tap test); injured non-stressed, 3.8 mm. The Cotton test and Tap test had, respectively, 73.3% and 70% sensitivity, 100% and 90% specificity, 86.7% and 80% diagnostic accuracy. CONCLUSIONS: Our cadaveric study compared the Cotton and Tap tests for detection of coronal plane syndesmotic instability. Both tests demonstrated similar increases in the TFCS measurements in stressed injured conditions when compared to intact non-stressed and stressed conditions, as well as injured non-stressed conditions.


Assuntos
Traumatismos do Tornozelo , Instabilidade Articular , Traumatismos do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/diagnóstico por imagem , Cadáver , Humanos , Reprodutibilidade dos Testes
17.
Zhongguo Gu Shang ; 34(6): 544-9, 2021 Jun 25.
Artigo em Chinês | MEDLINE | ID: mdl-34180175

RESUMO

OBJECTIVE: To compare and analyze the mechanical differences between single-row suture anchor fixation for repairing rotator cuff injuries and double-row suture bridges for repairing rotator cuff injuries from a biomechanical perspective. METHODS: The CT scan data of healthy adult shoulder joint were imported into Mimics, Geomagics and Hypermesh to carry out reverse reconstruction of two repair models, material assignment and mesh division, and the tearing of supraspinatus muscle was designed. After treatments, the load and boundary conditions were applied to the shoulder joint in ABAQUS software. The shoulder joint was fixed with four working conditions including flexion 15 °, flexion 30 °, internal rotation 15 ° and internal rotation 30 ° after anchor fixationand repair. The stress changes of the upper rotator cuff muscle and the anchor with thread were compared under these four conditions. RESULTS: Under the two flexion conditions, the stress of the supraspinatus in the double row suture bridge fixation model was 8.3% and 12% less than that in the single-row suture anchor fixation, respectively. Under the two internal rotation conditions, the stress of supraspinatus in the double row suture bridge fixation model was 47% and 48% less than that in the single row fixation repair model, respectively. CONCLUSION: The "load sharing" effect between the two rows of four anchors makes the stress distribution more dispersed, increases the contact area between the supraspinatus muscle and the humerus, reduces the stress of the anchor, avoids the serious stress concentration phenomenon, and explains the advantages of the fixation method of the double row suture bridge from the biomechanical angle.


Assuntos
Lesões do Manguito Rotador , Adulto , Fenômenos Biomecânicos , Cadáver , Humanos , Lesões do Manguito Rotador/cirurgia , Âncoras de Sutura , Técnicas de Sutura , Suturas
18.
Bull Tokyo Dent Coll ; 62(2): 99-106, 2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-33994425

RESUMO

The objective of this study was to analyze the distribution and morphology of the valves in the human retromandibular vein. The retromandibular, internal thoracic, azygos, femoral, and brachial veins were harvested from 46 cadavers donated to the Department of Anatomy at Tokyo Dental College for dissection. The frequency of the valves in each vein, the length of the cusps, and the thickness of the vein itself were measured. Valves were present at high frequency (92.1%) in the veins of the limbs and had cusps at least twice as long as the internal diameter of the vein. Veins in the trunk contained a lower frequency of valves, with cusps that tended to be shorter (1.60±0.77) than those of the venous valves in the limbs (2.12±0.60). The valves of the retromandibular vein tended to resemble venous valves in the trunk in terms of both frequency and morphology. The main function of venous valves in the limbs is to prevent retrograde flow. Conversely, valves in the veins of the trunk and retromandibular vein play a role in retaining blood in the veins, and their relationship to other veins means that they can cause major hemorrhage.


Assuntos
Veias , Cadáver , Humanos , Tóquio
19.
Bone Joint J ; 103-B(6 Supple A): 81-86, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34053279

RESUMO

AIMS: The objective of this study is to assess the use of ultrasound (US) as a radiation-free imaging modality to reconstruct 3D anatomy of the knee for use in preoperative templating in knee arthroplasty. METHODS: Using an US system, which is fitted with an electromagnetic (EM) tracker that is integrated into the US probe, allows 3D tracking of the probe, femur, and tibia. The raw US radiofrequency (RF) signals are acquired and, using real-time signal processing, bone boundaries are extracted. Bone boundaries and the tracking information are fused in a 3D point cloud for the femur and tibia. Using a statistical shaping model, the patient-specific surface is reconstructed by optimizing bone geometry to match the point clouds. An accuracy analysis was conducted for 17 cadavers by comparing the 3D US models with those created using CT. US scans from 15 users were compared in order to examine the effect of operator variability on the output. RESULTS: The results revealed that the US bone models were accurate compared with the CT models (root mean squared error (RM)S: femur, 1.07 mm (SD 0.15); tibia, 1.02 mm (SD 0.13). Additionally, femoral landmarking proved to be accurate (transepicondylar axis: 1.07° (SD 0.65°); posterior condylar axis: 0.73° (SD 0.41°); distal condylar axis: 0.96° (SD 0.89°); medial anteroposterior (AP): 1.22 mm (SD 0.69); lateral AP: 1.21 mm (SD 1.02)). Tibial landmarking errors were slightly higher (posterior slope axis: 1.92° (SD 1.31°); and tubercle axis: 1.91° (SD 1.24°)). For implant sizing, 90% of the femora and 60% of the tibiae were sized correctly, while the remainder were only one size different from the required implant size. No difference was observed between moderate and skilled users. CONCLUSION: The 3D US bone models were proven to be closely matched compared with CT and suitable for preoperative planning. The 3D US is radiation-free and offers numerous clinical opportunities for bone visualization rapidly during clinic visits, to enable preoperative planning with implant sizing. There is potential to extend its application to 3D dynamic ligament balancing, and intraoperative registration for use with robots and navigation systems. Cite this article: Bone Joint J 2021;103-B(6 Supple A):81-86.


Assuntos
Artroplastia do Joelho , Imageamento Tridimensional , Articulação do Joelho/anatomia & histologia , Modelagem Computacional Específica para o Paciente , Ultrassonografia/métodos , Pontos de Referência Anatômicos , Cadáver , Humanos , Ondas de Rádio , Tomografia Computadorizada por Raios X
20.
Bone Joint J ; 103-B(6 Supple A): 87-93, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34053287

RESUMO

AIMS: Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture, which leads to femoral joint line elevation. There is a paucity of data describing the effect of joint line elevation on mid-flexion stability and knee kinematics. Thus, the goal of this study was to quantify the effect of joint line elevation on mid-flexion laxity. METHODS: Six computational knee models with cadaver-specific capsular and collateral ligament properties were implanted with a posterior-stabilized (PS) TKA. A 10° flexion contracture was created in each model to simulate a capsular contracture. Distal femoral resections of + 2 mm and + 4 mm were then simulated for each knee. The knee models were then extended under a standard moment. Subsequently, varus and valgus moments of 10 Nm were applied as the knee was flexed from 0° to 90° at baseline and repeated after each of the two distal resections. Coronal laxity (the sum of varus and valgus angulation with respective maximum moments) was measured throughout flexion. RESULTS: With + 2 mm resection at 30° and 45° of flexion, mean coronal laxity increased by a mean of 3.1° (SD 0.18°) (p < 0.001) and 2.7° (SD 0.30°) (p < 0.001), respectively. With + 4 mm resection at 30° and 45° of flexion, mean coronal laxity increased by 6.5° (SD 0.56°) (p < 0.001) and 5.5° (SD 0.72°) (p < 0.001), respectively. Maximum increased coronal laxity for a + 4 mm resection occurred at a mean 15.7° (11° to 33°) of flexion with a mean increase of 7.8° (SD 0.2°) from baseline. CONCLUSION: With joint line elevation in primary PS TKA, coronal laxity peaks early (about 16°) with a maximum laxity of 8°. Surgeons should restore the joint line if possible; however, if joint line elevation is necessary, we recommend assessment of coronal laxity at 15° to 30° of knee flexion to assess for mid-flexion instability. Further in vivo studies are warranted to understand if this mid-flexion coronal laxity has negative clinical implications. Cite this article: Bone Joint J 2021;103-B(6 Supple A):87-93.


Assuntos
Artroplastia do Joelho/métodos , Contratura/etiologia , Fêmur/cirurgia , Instabilidade Articular/etiologia , Modelagem Computacional Específica para o Paciente , Adulto , Fenômenos Biomecânicos , Cadáver , Contratura/prevenção & controle , Humanos , Instabilidade Articular/prevenção & controle , Masculino , Amplitude de Movimento Articular
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