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1.
Arch Orthop Trauma Surg ; 144(6): 2631-2639, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38703213

RESUMO

INTRODUCTION: Preoperative planning is a critical step in the success of any complex surgery. The pur-pose of this study is to evaluate the advantage of VR glasses in surgical planning of complex tibial plateau fractures compared to CT planning. MATERIALS AND METHODS: Five orthopedic surgeons performed preoperative planning for 30 fractures using either conventional CT slices or VR visualization with a VR headset. Planning was performed in a randomized order with a 3-month interval between planning sessions. A standardized questionnaire assessed planned operative time, planning time, fracture classification and understanding, and surgeons' subjective confidence in surgical planning. RESULTS: The mean planned operative time of 156 (SD 47) minutes was significantly lower (p < 0.001) in the VR group than in the CT group (172 min; SD 44). The mean planning time in the VR group was 3.48 min (SD 2.4), 17% longer than in the CT group (2.98 min, SD 1.9; p = 0.027). Relevant parameters influencing planning time were surgeon experience (-0.61 min) and estimated complexity of fracture treatment (+ 0.65 min). CONCLUSION: The use of virtual reality for surgical planning of complex tibial plateau fractures resulted in significantly shorter planned operative time, while planning time was longer compared to CT planning. After VR planning, more surgeons felt (very) well prepared for surgery.


Assuntos
Fraturas da Tíbia , Tomografia Computadorizada por Raios X , Realidade Virtual , Humanos , Fraturas da Tíbia/cirurgia , Fraturas da Tíbia/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Feminino , Masculino , Duração da Cirurgia , Adulto , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Fraturas do Planalto Tibial
2.
Arch Orthop Trauma Surg ; 142(6): 1055-1061, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33590315

RESUMO

INTRODUCTION: The aim of this investigation was to better understand the differences in local bone quality at the distal femur and their correlation with biomechanical construct failure, with the intention to identify regions of importance to optimize implant anchorage. MATERIALS AND METHODS: Seven fresh-frozen female femurs underwent high-resolution peripheral quantitative computed tomography (HR-pQCT) to determine bone mineral density (BMD) within three different regions of interest (distal, intermedium, and proximal) at the distal femur. In addition, local bone quality was assessed by measuring the peak torque necessary to break out the trabecular bone along each separate hole of a locking compression plate (LCP) during its instrumentation. Finally, biomechanical testing was performed using cyclic axial loading until failure in an AO/OTA 33 A3 fracture model. RESULTS: Local BMD was highest in the distal region. This was confirmed by the measurement of local bone quality using DensiProbe™. The most distal holes represented locations with the highest breakaway torque resistance, with the holes on the posterior side of the plate indicating higher values than those on its anterior side. We demonstrated strong correlation between the cycles to failure and local bone strength (measured with DensiProbe™) in the most distal posterior screw hole, having the highest peak torque. CONCLUSION: The local bone quality at the distal femur indicates that in plated distal femur fractures the distal posterior screw holes seem to be the key ones and should be occupied. Measurement of the local bone strength with DensiProbe™ is one possibility to determine the risk of construct failure, therefore, thresholds need to be defined.


Assuntos
Fraturas do Fêmur , Fixação Interna de Fraturas , Fenômenos Biomecânicos , Placas Ósseas , Cadáver , Feminino , Fraturas do Fêmur/diagnóstico por imagem , Fraturas do Fêmur/cirurgia , Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Humanos , Indicadores de Qualidade em Assistência à Saúde
3.
Unfallchirurg ; 125(2): 165-172, 2022 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-34755211

RESUMO

The v. Bodelschwingh Foundation Bethel can look back on a tradition of more than 150 years in the treatment of people with disabilities. The trauma patient collective is regularly characterized by the most severe mental and physical developmental disorders and (multiple) disabilities, with and without behavioral disorders and concomitant internal diseases. This special combination requires treatment and indication assessment both medically and in nursing, which must be specifically weighed up and adapted in all treatment steps. Treatment guidelines or recommendations for this patient group do not exist in the literature. Furthermore, the treatment of fractures in people with disabilities cannot always follow established concepts. Due to a high postoperative complication rate, conservative treatment plays a crucial role. The decision for surgical treatment must be made on an interdisciplinary and individual basis, taking all factors into account. Special attention must be paid to the procedure to be chosen (stability, functional needs).


Assuntos
Pessoas com Deficiência , Transtornos Mentais , Extremidades , Humanos
4.
BMC Musculoskelet Disord ; 22(1): 841, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592967

RESUMO

BACKGROUND: The implantation of screws is a standard procedure in musculoskeletal surgery. Heat can induce thermal osteonecrosis, damage the bone and lead to secondary problems like implant loosening and secondary fractures. The aim of this study was to investigate whether screw insertion generates temperatures that can cause osteonecrosis. METHODS: We measured the temperature of twenty human femur diaphysis in a total of 120 measurements, while screws of different material (stainless steel and titanium alloy) and different design (locking and cortex screw) were inserted in three different screwing modes (manual vs. machine screwing at full and reduced rotational speed) with 6 thermocouples (3 cis and 3 trans cortex). Each was placed at a depth of 2 mm with a distance of 1.5 mm from the outer surface of the screw. RESULTS: The screw design (cortical > locking), the site of measurement (trans-cortex > cis-cortex) and the type of screw insertion (hand insertion > machine insertion) have an influence on the increase in bone temperature. The screw material (steel > titanium), the site of measurement (trans-cortex > cis-cortex) and the type of screw insertion (machine insertion > hand insertion) have an influence on the time needed to cool below critical temperature values. The combination of the two parameters (maximum temperature and cooling time), which is particularly critical for osteonecrosis, is found only at the trans-cortex. CONCLUSION: Inserting a screw hast the potential to increase the temperature of the surrounding bone tissue above critical values and therefore can induce osteonecrosis. The trans-cortex is the critical area for the development of temperatures above the osteonecrosis threshold, making effective cooling by irrigation difficult. It would be conceivable to cool the borehole with cold saline solution before inserting the screw or to cool the screw in cold saline solution. If possible, insertion by hand should be considered.


Assuntos
Diáfises , Temperatura Alta , Fenômenos Biomecânicos , Parafusos Ósseos/efeitos adversos , Osso e Ossos , Diáfises/diagnóstico por imagem , Diáfises/cirurgia , Humanos , Aço Inoxidável
5.
BMC Musculoskelet Disord ; 22(1): 709, 2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34407777

RESUMO

BACKGROUND: The prediction of the stability of bones is becoming increasingly important. Especially osteoporotic vertebral body fractures are a growing problem and an increasing burden on the health system. Therefore, the aim of this study was to provide the best possible description of the relationship between the material properties of human vertebral trabecular bone measured under the most physiological conditions possible and the bone mineral density (BMD) determined by clinical quantitative computed tomography (QCT). METHODS: Forty eight cylindric cancellous bone samples with a diameter of 7.2 mm obtained from 13 human fresh-frozen lumbar vertebrae from 5 donors (3 men, 2 women) have been used for this study. After the specimens were temporarily reinserted into the vertebral body, the QCT was performed. For mechanical testing, the samples were embedded in a load-free manner using polymethylmetacrylate (PMMA). The surrounding test chamber was filled with phosphate buffered saline (PBS) and heated to 37 °C during the test. After 10 preconditioning load cycles, destructive testing was performed under axial compression. After determining the fracture site, BMD has been evaluated in this region only. Regression analyses have been performed. RESULTS: Fracture site had an average length of 2.4 (±1.4) mm and a position of 43.9 (±10.9) percent of the measurement length from the cranial end. No fracture reached the embedding. The average BMD at the fracture site was 80.2 (±28.7 | min. 14.5 | max. 137.8) mgCaHA/ml. In summary the results of the regression analyses showed for all three parameters a very good quality of fit by a power regression. CONCLUSION: The results of this study show that QCT-based bone density measurements have a good predictive power for the material properties of the vertebral cancellous bone measured under near to physiological conditions. The mechanical bone properties of vertebral cancellous bone could be modelled with high accuracy in the investigated bone density range.


Assuntos
Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Densidade Óssea , Osso Esponjoso/diagnóstico por imagem , Feminino , Humanos , Vértebras Lombares/diagnóstico por imagem , Masculino , Fraturas por Osteoporose/diagnóstico por imagem , Fraturas da Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X
6.
J Orthop Traumatol ; 22(1): 5, 2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33638741

RESUMO

BACKGROUND: Given the increasing number of osteoporotic fractures of the distal femur, screw augmentation with bone cement is an option to enhance implant anchorage. However, in implant removal or revision surgeries, the cement cannot be removed from the distal femur without an extended surgical procedure. Therefore, the aims of this study were to investigate (1) whether cement augmentation has any influence on screw removal and removal torque, and (2) whether the implantation of a femoral component of a knee arthroplasty and its initial interface stability are affected by the remaining screws/cement. MATERIAL AND METHODS: Eight pairs of fresh-frozen human female cadaveric distal femurs (mean age, 86 years) with a simulated AO/OTA 33 A3 fracture were randomized in paired fashion to two groups and fixed with a distal femoral locking plate using cannulated perforated locking screws. Screw augmentation with bone cement was performed in one of the groups, while the other group received no screw augmentation. Following biomechanical testing until failure (results published separately), the screws were removed and the removal torque was measured. A femoral component of a knee arthroplasty was then implanted, and pull-out tests were performed after cement curing. Interference from broken screws/cement was assessed, and the maximum pull-out force was measured. RESULTS: The mean screw removal torque was not significantly different between the augmented (4.9 Nm, SD 0.9) and nonaugmented (4.6 Nm, SD 1.3, p = 0.65) screw groups. However, there were significantly more broken screws in in the augmented screw group (17 versus 9; p < 0.001). There was no significant difference in the pull-out force of the femoral component between the augmented (2625 N, SD 603) and nonaugmented (2653 N, SD 542, p = 0.94) screw groups. CONCLUSION: The screw removal torque during implant removal surgery does not significantly differ between augmented and nonaugmented screws. In the augmented screw group, significantly more screws failed. To overcome this, the use of solid screws in holes B, C, and G can be considered. Additionally, it is possible to implant a femoral component for knee arthroplasty that retains the initial anchorage and does not suffer from interference with broken screws and/or residual cement. LEVEL OF EVIDENCE: 5.


Assuntos
Artroplastia do Joelho/métodos , Cimentos Ósseos , Parafusos Ósseos , Remoção de Dispositivo/métodos , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/métodos , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos , Placas Ósseas , Cadáver , Feminino , Fraturas do Fêmur/fisiopatologia , Humanos , Reoperação
7.
BMC Musculoskelet Disord ; 21(1): 806, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33272239

RESUMO

BACKGROUND: A new locking screw technology, named variable fixation, has been developed aiming at promoting bone callus formation providing initial rigid fixation followed by progressive fracture gap dynamisation. In this study, we compared bone callus formation in osteotomies stabilized with standard locking fixation against that of osteotomies stabilized with variable fixation in an established tibia ovine model. METHODS: A 3 mm tibial transverse osteotomy gap was stabilized in three groups of six female sheep each with a locking plate and either 1) standard fixation in both segments (group LS) or 2) variable fixation in the proximal and standard fixation in the distal bone segment (group VFLS3) or 3) variable fixation in both segments (group VFLS6). The implantation site and fracture healing were compared between groups by means of radiologic, micro tomographic, biomechanical, and histological investigations. RESULTS: Compared to LS callus, VFLS3 callus was 40% larger and about 3% denser, while VFLS6 callus was 93% larger and its density about 7.2% lower. VFLS3 showed 65% and VFLS6 163% larger amount of callus at the cis-cortex. There wasn't a significant difference in the amount of callus at the cis and trans-cortex in groups featuring variable fixation only. Investigated biomechanical variables were not significantly different among groups and histology showed comparable good healing in all groups. Tissues adjacent to the implants did not show any alteration of the normal structure in all groups. CONCLUSIONS: Variable fixation promoted the formation of a larger amount of bone callus, equally distributed at the cis and trans cortices. The histological and biomechanical properties of the variable fixation callus were equivalent to those of the standard fixation callus. The magnitude of variable fixation had a biological effect on the formation of bone callus. At the implantation site, the usage of variable fixation did not raise additional concerns with respect to standard fixation. The formation of a larger amount of mature callus suggests that fractures treated with variable fixation might have a higher probability to bridge the fracture gap. The conditions where its usage can be most beneficial for patients needs to be clinically defined.


Assuntos
Fixação Interna de Fraturas , Fraturas da Tíbia , Animais , Fenômenos Biomecânicos , Placas Ósseas , Parafusos Ósseos , Calo Ósseo/diagnóstico por imagem , Feminino , Consolidação da Fratura , Humanos , Osteotomia , Ovinos
8.
Arch Orthop Trauma Surg ; 140(3): 441, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31897592

RESUMO

The original version of this article unfortunately contained a mistake.

9.
Arch Orthop Trauma Surg ; 139(12): 1723-1729, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31385021

RESUMO

INTRODUCTION: Complex radial head fractures are difficult to treat. In cases where stable fixation cannot be achieved, radial head resection or primary arthroplasty are frequently performed. Ex situ reconstruction of comminuted fractures may also be an option. This technique has widely been neglected in the literature, and only two small case series report satisfactory results. The aim of the present case series was to determine the functional and radiological outcomes of ex situ reconstructed Mason III and Mason IV fractures. We expect that the on-table reconstruction of comminuted radial head fractures will lead to bony union with no avascular necrosis in the postoperative course, which will demonstrate that this operative procedure is a reasonable option. PATIENTS AND METHODS: Two Mason type III and seven Mason type IV fractures (including four Monteggia-like lesions) were reconstructed ex situ. The mean age of the patients was 47 years (range 22-64). The clinical examination included RoM tests, elbow stability tests, and a neurological examination. The functional outcome was assessed with the MEPS and DASH score. The radiographic examination included a.p. and lateral views of the elbow to detect non-unions, inadequacy or loss of reduction, radial head necrosis, heterotopic ossifications and signs of posttraumatic arthritis. RESULTS: The mean follow-up time was 39 months (range 11-64). The mean MEPS was 82 points (range 15-100), and the mean DASH score was 20 points (range 0-85). All ex situ-reconstructed radial heads survived, and no signs of avascular necrosis were observed. Bony union was achieved in all but one patient who presented with an asymptomatic non-union. Signs of posttraumatic arthritis were found in all patients. With regard to the radial head, neither secondary resection nor arthroplasty had to be performed. All patients returned to their pre-injury occupations. CONCLUSION: Ex situ radial head reconstruction can be a reliable option in the surgical treatment of complex radial head fractures associated with severe elbow trauma. Even in the midterm follow-up, no signs of avascular necrosis were observed. Modern implants may even extend the indications for reconstruction in such cases. LEVEL OF EVIDENCE: Level IV-retrospective cohort study.


Assuntos
Fraturas Cominutivas/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Fraturas do Rádio/cirurgia , Adulto , Artroplastia de Substituição/métodos , Articulação do Cotovelo/cirurgia , Epífises/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ossificação Heterotópica/cirurgia , Próteses e Implantes , Rádio (Anatomia)/cirurgia , Estudos Retrospectivos , Adulto Jovem
10.
Eur Spine J ; 27(4): 789-796, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29417323

RESUMO

INTRODUCTION: A balanced ratio of the main parameters of lumbar lordosis (LL) and pelvic incidence (PI) has high clinical relevance. A postoperative mismatch of LL and PI has been described in the literature to be associated with an inferior clinical outcome and higher postoperative revision rates. The aim of this retrospective, radiological study is to evaluate the magnitude of relordosing in mono-/bisegmental TLIF spondylodesis affecting the spino-pelvic alignment and the main contributing factors. MATERIALS AND METHODS: 164 patients (pat.) underwent monosegmental (n = 115, G1) and bisegmental (n = 49, G2) TLIF spondylodesis, respectively, for different indications in 2016 in our hospital. Pelvic incidence, lumbar lordosis (preop., postop., 3 months postop.), implanted cage sizes, and the use of additional Smith-Petersen osteotomies were analysed retrospectively. Patients were divided into three groups depending on match of LL/PI (PI-LL < 10° green, PI-LL = 10-20° yellow, PI-LL > 20° red). Furthermore, a differentiation was made between surgeons with more than or less than 10 years of spinal surgery experience, respectively. RESULTS: 29.6% of pat. in G1 and 16.3% in G2 showed a highly pronounced preoperative spino-pelvic mismatch (red). A high grade of mismatch (yellow) between LL/PI was seen in 29.6% in G1 and in 38.8% in G2. The remaining patients already had a balanced ratio of LL/PI (green). Through relordosing TLIF the LL could be corrected significantly (p < 0.05). Therefore, the number of patients with a balanced sagittal alignment (green) increased from 40.9% preop. to 70.4% postoperative in G1 and from 44.9 to 85.7% in G2 (p < 0.05). The number of pat. with highly pronounced preoperative mismatch (red) could be lowered in G1 from 29.6 to 13.9% and in G2 from 16.3 to 2% postoperative (p < 0.05). In G1, the preoperative LL could be corrected from 46.3° to 53.8° (yellow) and 35.7° to 45.8° (red), while in G2, a correction was possible from 43.4° to 51.5° (yellow) and 36.6° to 50.1° (red) (p < 0.05). No significant difference of segmental/complete LL was found between radiologic measurement immediately postoperative and at the 3-month follow-up. In monosegmental fusion higher cages sizes lead to a better match of LL/PI (p < 0.05). The specific cage lordosis (5° vs. 10°) had no influence on the extent of relordosing. Experienced surgeons had significant higher postoperative matches of LL/PI (p < 0.05) and accomplished more osteotomies (p < 0.05). DISCUSSION: This retrospective study demonstrates that significant relordosing and, therefore, correction of the spino-pelvic alignment are possible with mono-/bisegmental TLIF spondylodesis. Positive influence of higher cage sizes and surgeon's experience was shown. We conclude that the ratio of LL/PI should be taken into account preoperatively in lumbar fusion surgery when planning mono-/bisegmental TLIF spondylodesis to optimize spino-pelvic alignment. These slides can be retrieved under Electronic Supplementary Material.


Assuntos
Lordose/cirurgia , Vértebras Lombares/cirurgia , Pelve/cirurgia , Fusão Vertebral/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Distinções e Prêmios , Feminino , Alemanha , Humanos , Lordose/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Osteotomia/estatística & dados numéricos , Pelve/diagnóstico por imagem , Período Pós-Operatório , Estudos Retrospectivos , Sociedades Médicas , Fusão Vertebral/efeitos adversos , Adulto Jovem
11.
Knee Surg Sports Traumatol Arthrosc ; 25(4): 1184-1190, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26239862

RESUMO

PURPOSE: Dynamic intraligamentary stabilization (DIS) has been introduced for the repair of acute anterior cruciate ligament (ACL) tears as an alternative to delayed reconstruction. The aim of the present study was to compare knee joint kinematics after DIS to those of the ACL-intact and ACL-deficient knee under simulated Lachman/KT-1000 and pivot-shift tests. We hypothesized that DIS provides knee joint kinematics equivalent to an intact ACL. METHODS: With the use of a robotic knee simulator, knee kinematics were determined in simulated Lachman/KT-1000 and pivot-shift tests at 0°, 15°, 30°, 60°, and 90° of flexion in eight cadaveric knees under the following conditions: (1) intact ACL, (2) ACL deficiency, (3) DIS with a preload of 60 N, and (4) DIS with a preload of 80 N. Statistical analyses were performed using two-factor repeated-measures analysis of variance. The significance level was set at a p value of <0.05. RESULTS: After DIS with a preload of either 60 N or 80 N, the anterior translation was significantly reduced in the simulated Lachman/KT-1000 and pivot-shift tests when compared to the ACL-deficient knee (p < 0.05). No significant differences were observed between the DIS reconstruction with a preload of 80 N and the intact ACL with regard to anterior laxity in either test. However, DIS with a preload of only 60 N was not able to restore knee joint kinematics to that of an intact knee in all degrees of flexion. CONCLUSION: DIS with a preload of 80 N restores knee joint kinematics comparable to that of an ACL-intact knee and is therefore capable of providing knee joint stability during ACL healing. DIS therefore provides a new technique for primary ACL repair with superior biomechanical properties in comparison with other techniques that have been described previously, although further clinical studies are required to determine its usefulness in clinical settings.


Assuntos
Reconstrução do Ligamento Cruzado Anterior/métodos , Articulação do Joelho/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Fenômenos Biomecânicos/fisiologia , Cadáver , Humanos , Instabilidade Articular/fisiopatologia , Instabilidade Articular/cirurgia , Articulação do Joelho/cirurgia , Pessoa de Meia-Idade , Exame Físico/métodos
12.
Arch Orthop Trauma Surg ; 137(1): 63-71, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28005168

RESUMO

INTRODUCTION: The high rigidity of metal implants may be a cause of failure after fixation of proximal humerus fractures. Carbon fiber-reinforced polyetheretherketone (PEEK) plates with a modulus similar to human cortical bone may help to overcome this problem. The present study assesses the biomechanical behavior of a PEEK plate compared with a titanium locking plate. MATERIALS AND METHODS: Unstable two- and three-part fractures were simulated in 12 pairs of cadaveric humeri and were fixed with either a PEEK or a titanium locking plate using a pairwise comparison. With an optical motion capture system, the stiffness, failure load, plate bending, and the relative motion at the bone-implant interface and at the fracture site were evaluated. RESULTS: The mean load to failure for two- and three-part fracture fixations was, respectively, 191 N (range 102-356 N) and 142 N (range 102-169 N) in the PEEK plate group compared with 286 N (range 191-395 N) and 258 N (range 155-366 N) in the titanium locking plate group. The PEEK plate showed significantly more bending in both the two- and three-part fractures (p < 0.05), an increased relative motion at the bone-implant interface and lower stiffness values (p < 0.05). CONCLUSION: In this biomechanical study on unstable proximal humerus fractures, fixation with a PEEK plate showed lower fixation strength and increased motion at the bone-implant interface compared with a titanium locking plate.


Assuntos
Materiais Biocompatíveis , Placas Ósseas , Fixação Interna de Fraturas/instrumentação , Cetonas , Polietilenoglicóis , Fraturas do Ombro/cirurgia , Titânio , Idoso , Idoso de 80 Anos ou mais , Benzofenonas , Fenômenos Biomecânicos , Cadáver , Carbono , Fibra de Carbono , Feminino , Humanos , Masculino , Polímeros , Estresse Mecânico
13.
BMC Musculoskelet Disord ; 17: 318, 2016 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-27472925

RESUMO

BACKGROUND: Tibiotalocalcaneal arthrodesis (TTCA) using intramedullary nails is a salvage procedure for many diseases in the ankle and subtalar joint. Despite "newly described intramedullary nails" with specific anatomical shapes there still remain major complications regarding this procedure. The following study presents a modified biomechanical test setup for investigations of the hindfoot. METHODS: Nine fresh-frozen specimens from below the human knee were anaysed using the Hindfoot Arthrodesis Nail (Synthes) instrument. Quasi-static biomechanical testing was performed for internal/external rotation, varus/valgus and dorsal/plantar flexion using a modified established setup (physiological load entrance point, sledge at lever arm to apply pure moments). Additionally, a 3D optical measurement system was added to allow determination of interbony movements. RESULTS: The mean torsional range of motion (ROM) calculated from the actuator data of a material testing machine was 10.12° (SD 0.6) compared to 10° (SD 2.83) as measured with the Optotrak® system (between tibia and calcaneus). The Optotrak showed 40 % more rotation in the talocrural joint. Mean varus/valgus ROM from the material testing flexion machine was seen to be 5.65° (SD 1.84) in comparison to 2.82° (SD 0.46) measured with the Optotrak. The subtalar joint showed a 70 % higher movement when compared to the talocrural joint. Mean ROM in the flexion test was 5.3° (SD 1.45) for the material testing machine and 2.1° (SD 0.39) for the Optotrak. The movement in the talocrural joint was 3 times higher compared to the subtalar joint. CONCLUSION: The modified test setup presented here for the hindfoot allows a physiological biomechanical loading. Moreover, a detailed characterisation of the bone-implant constructs is possible.


Assuntos
Articulação do Tornozelo/fisiopatologia , Artrodese/instrumentação , Pinos Ortopédicos , Teste de Materiais/métodos , Amplitude de Movimento Articular , Articulação Talocalcânea/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Articulação do Tornozelo/cirurgia , Artrodese/efeitos adversos , Artrodese/métodos , Fenômenos Biomecânicos , Calcâneo/cirurgia , Feminino , Pé/cirurgia , Humanos , Imageamento Tridimensional , Masculino , Teste de Materiais/instrumentação , Rotação , Articulação Talocalcânea/cirurgia , Tálus/cirurgia , Tíbia/cirurgia
14.
J Shoulder Elbow Surg ; 24(12): 1968-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26255200

RESUMO

BACKGROUND: Shear forces at the bone-implant interface lead to a loss of reduction after locking plate fixation of proximal humeral fractures. The aim of the study was to analyze the roles of medial support screws and screw augmentation in failure loads and motion at the bone-implant interface after locking plate fixation of proximal humeral fractures. METHODS: Unstable 3-part fractures were simulated in 6 pairs of cadaveric humeri and were fixed with a DiPhos-H locking plate (Lima Corporate, Udine, Italy). An additional medial support screw was implanted in 1 humerus of every donor. The opposite humerus was stabilized with a medial support screw and additional bone cement augmentation of the 2 anteriorly directed head screws. Specimens were loaded in the varus bending position. Stiffness, failure loads, plate bending, and the motion at the bone-implant interface were evaluated using an optical motion capture system. RESULTS: The mean load to failure was 669 N (standard deviation [SD], 117 N) after fixation with medial support screws alone and 706 N (SD, 153 N) after additional head screw augmentation (P = .646). The initial stiffness was 453 N/mm (SD, 4.16 N/mm) and 461 N/mm (SD, 64.3 N/mm), respectively (P = .594). Plate bending did not differ between the 2 groups. However, motion at the bone-implant interface was significantly reduced after head screw augmentation (P < .05). CONCLUSION: The addition of bone cement to augment anteriorly directed head screws does not increase stiffness and failure loads but reduces motion at the bone-implant interface. Thus, the risk of secondary dislocation of the head fragment may be reduced.


Assuntos
Placas Ósseas , Parafusos Ósseos , Interface Osso-Implante/fisiopatologia , Fixação Interna de Fraturas/instrumentação , Fraturas do Ombro/cirurgia , Idoso , Fenômenos Biomecânicos , Cimentos Ósseos , Interface Osso-Implante/diagnóstico por imagem , Cadáver , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas do Ombro/diagnóstico por imagem , Fraturas do Ombro/fisiopatologia , Tomografia Computadorizada por Raios X
15.
Int Orthop ; 38(1): 47-53, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24114243

RESUMO

PURPOSE: Fractures of the femur associated with total hip arthroplasty are a significant concern in orthopaedic and trauma surgery. However, little is known about the different biomechanical properties of internal fixation systems in combination with periprosthetic fractures. In this study two new internal fixation systems for periprosthetic fractures are investigated using a cadaver fracture model simulating a Vancouver B1 periprosthetic femur fracture. METHODS: Nine pairs of fresh-frozen cadaver femurs were scanned by dual X-ray absorptiometry. Cementless total hip prostheses were implanted and a periprosthetic femur fracture was simulated. Fractures were randomly fixed either with the fixed angle locking attachment plate (LAP®, Depuy Synthes®, Solothurn, Switzerland) or the variable angle non-contact bridging plate (NCB®, Zimmer GmbH, Winterthur, Switzerland). Each construct was cyclically loaded to failure in axial compression. RESULTS: Axial stiffness and cycles to failure were significantly higher in the NCB group. Both systems were able to be fixed well around the femoral stem. CONCLUSION: The two different internal fixation systems for periprosthetic fractures differed significantly in our setup. The non-contact bridging plate system revealed significantly higher failure load and may be the preferred option where high stability and load capacity is needed right after operation.


Assuntos
Artroplastia de Quadril , Placas Ósseas/classificação , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas/instrumentação , Prótese de Quadril , Fraturas Periprotéticas/cirurgia , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Fenômenos Biomecânicos , Densidade Óssea , Cadáver , Feminino , Fraturas do Fêmur/etiologia , Fixação Interna de Fraturas/métodos , Prótese de Quadril/efeitos adversos , Humanos , Masculino , Teste de Materiais , Fraturas Periprotéticas/etiologia
16.
Acta Orthop Belg ; 80(1): 106-11, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24873093

RESUMO

Aim of the present study was to compare the clinical and radiographic outcome of tension band wiring and precontoured locking compression plate fixation in patients treated surgically for an isolated olecranon fractures type IIA according to the Mayo classification. Of 26 patients presenting with an isolated Mayo type IIA olecranon fracture, 13 underwent fixation with a precontoured locking compression plate (group A), 13 patients were treated with tension band wiring (group B). At a mean follow-up of 43 months, patients were clinically and radiographically re-examined using the DASH score, the Mayo Elbow Performance score (MEPS) and anteroposterior and lateral radiographs. The mean DASH score was 14 points in group A and 12.5 points in group B. Regarding the MEPS, 92% of the patients in group A achieved a good to excellent results in comparison to 77% in group B. No significant differences between the two groups could be detected regarding the clinical and radiographic outcome. Implant-related irritations requiring hardware removal occurred more frequently in group B (12 vs. 7). Procedure and implant related costs were significantly higher in group A. Tension band wiring is still a preferable surgical method to treat simple isolated olecranon fractures. The patient must be informed that in all likelihood implant removal will be required once the fracture has healed. Fixation with precontoured locking compression plates does not provide better functional and radiographic outcome but is more expensive than tension band wiring.


Assuntos
Placas Ósseas , Fios Ortopédicos , Olécrano/lesões , Fraturas da Ulna/cirurgia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Olécrano/diagnóstico por imagem , Complicações Pós-Operatórias , Radiografia , Reoperação , Fraturas da Ulna/diagnóstico por imagem
17.
Orthopadie (Heidelb) ; 53(6): 393-403, 2024 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-38787408

RESUMO

BACKGROUND: Despite the high incidence of ankle sprains, the ideal treatment is controversial and a significant percentage of patients who have suffered an ankle sprain never fully recover. Even professional athletes are affected by this post-traumatic complication. There is strong evidence that permanent impairment after an ankle injury is often due to an inadequate rehabilitation and training program and too early return to sport. THERAPY AND REHABILITATION: Therefore, athletes should start a criteria-based rehabilitation after ankle sprain and gradually progress through the programmed activities, including e.g. cryotherapy, edema reduction, optimal load management, range of motion exercises to improve ankle dorsiflexion and digital guidance, stretching of the triceps surae with isometric exercises and strengthening of the peroneus muscles, balance and proprioception training, and bracing/taping. The fact that this is professional sport does not exempt it from consistent, stage-appropriate treatment and a cautious increase in load. However, there are a number of measures and tools that can be used in the intensive care of athletes to improve treatment and results.


Assuntos
Traumatismos do Tornozelo , Humanos , Traumatismos do Tornozelo/terapia , Traumatismos do Tornozelo/reabilitação , Traumatismos em Atletas/terapia , Traumatismos em Atletas/reabilitação , Crioterapia/métodos , Terapia por Exercício/métodos , Futebol , Entorses e Distensões/terapia , Entorses e Distensões/reabilitação , Resultado do Tratamento
18.
J Clin Med ; 13(11)2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38892743

RESUMO

(1) Background: Osteoarthritis (OA) is the most common joint disease in the world. It is chronic, systemic, progressive and disabling. Orthobiologics have the potential to positively alter the course of this disease. Therefore, the aim of this study is to evaluate the efficacy of SVF/ACP in the treatment of advanced osteoarthritis of the knee in an unfiltered patient population. We hypothesize that this therapy can improve the symptoms associated with osteoarthritis of the knee. We also hypothesize that there are patient-related factors that influence the efficacy of therapy. (2) Methods: Two hundred and thirteen patients with moderate to severe OA of the knee and SVF/ACP injection were recruited for this study. Patients were excluded if they did not provide informed consent or were not receiving SVF/ACP therapy. Pain, function, symptoms and quality of life were assessed using standardized scores (KOOS, WOMAC) before and after treatment. (3) Results: The VAS pain score was significantly reduced by at least 30% (p < 0.001). Knee function, as measured by the KOOS daily activity and sport scores, showed significant increases of 21% and 45%, respectively, at 6 months (p < 0.04). (4) Conclusions: Treatment of knee OA with SVF/ACP injection positively modifies the disease by significantly reducing pain and improving function.

19.
Front Surg ; 11: 1376441, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38756355

RESUMO

Delayed union and non-union of fractures continue to be a major problem in trauma and orthopedic surgery. These cases are challenging for the surgeon. In addition, these patients suffer from multiple surgeries, pain and disability. Furthermore, these cases are a major burden on healthcare systems. The scientific community widely agrees that the stability of fixation plays a crucial role in determining the outcome of osteosynthesis. The extent of stabilization affects factors like fracture gap strain and fluid flow, which, in turn, influence the regenerative processes positively or negatively. Nonetheless, a growing body of literature suggests that during the fracture healing process, there exists a critical time frame where intervention can stimulate the bone's return to its original form and function. This article provides a summary of existing evidence in the literature regarding the impact of different levels of fixation stability on the strain experienced by newly forming tissues. We will also discuss the timing and nature of this "window of opportunity" and explore how current knowledge is driving the development of new technologies with design enhancements rooted in mechanobiological principles.

20.
BMC Musculoskelet Disord ; 14: 111, 2013 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-23530869

RESUMO

BACKGROUND: The acute ankle sprain is one of the most common injuries seen in trauma departments. Ankle sprains have an incidence of about one injury per 10 000 people a day. In contrast tarsal coalition is a rare condition occurring in not more than one percent of the population. CASE PRESENTATION: We present the case of a 23 year old male patient with pain and local swelling after an acute ankle sprain. Initial clinical and radiological examination showed no pathologies. Due to prolonged pain, swelling and the inability of the patient to weight bear one week after trauma further diagnostics was performed. Imaging studies (MRI and CT) revealed a fracture of a talocalcaneal coalition. To the knowledge of the authors no fracture of a coalition was reported so far. CONCLUSION: This report highlights the presentation of symptomatic coalitions following trauma and furthermore, it points out the difficulties in the diagnosis and treatment of a rare entity after a common injury. A diagnostic algorithm has been developed to ensure not to miss a severe injury.


Assuntos
Traumatismos do Tornozelo/diagnóstico , Dor/diagnóstico , Entorses e Distensões/diagnóstico , Articulação Talocalcânea/lesões , Traumatismos do Tornozelo/complicações , Diagnóstico Diferencial , Humanos , Masculino , Dor/etiologia , Entorses e Distensões/complicações , Articulação Talocalcânea/patologia , Adulto Jovem
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