Making minimally invasive THR safe: conclusions from biomechanical simulation and analysis.
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ABSTRACT:
SUBMITTER: Noble PC
PROVIDER: S-EPMC2267523 | biostudies-other | 2007 Aug
REPOSITORIES: biostudies-other
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Project description:BackgroundThe purpose of this study was to determine the accuracy of used and new reamer systems for both hemispherical and minimally invasive (MIS) acetabular reamers.MethodsNew and used hemispherical and MIS acetabular reamers were tested on a computer numerical control machine to ream holes in special machinable wax blocks. Each reamer was tested 3 times in sizes 48 mm through 55 mm.ResultsThe used reamers significantly underreamed by an average of 1.33 vs 0.28 mm compared to new reamers. Hemispherical reamers underreamed significantly more than MIS reamers, with a mean difference of 0.99 vs 0.63 mm, respectively. Used hemispherical reamers showed an average ream undersize of 1.61 vs 0.37 mm, compared to new hemispherical reamers. Used MIS reamers showed an average ream undersize of 1.06 vs 0.20 mm for the new MIS reamers.ConclusionsFor a manufacturer-specified reamer size, both hemispherical and MIS reamers underream. Newer reamers cut truer to expected values than used ones. MIS reamers performed more accurately than hemispherical reamers. Used acetabular reamer systems may negatively affect the sizing of prepared acetabular beds; therefore, awareness of this potential inaccuracy should be considered when performing total hip arthroplasty.
| S-EPMC5485232 | biostudies-literature
Project description:The clinical benefits of totally minimal invasive esophagectomy (TIME) compared to open esophagectomy are documented and include reduced morbidity like pulmonary infections, shorter hospital stay and an increase in short-term quality of life. However, transition to TIME can be associated with a learning curve associated increased morbidity. We report our implementation of TIME using a 2-step approach, where the thoracoscopic part was added to the laparoscopic part in carefully selected patients. The hypothesis was that the 2-step implementation provides a safe and efficient implementation without compromising the outcomes for the patients. The aim of this study was to evaluation the implementation of minimal invasive esophagectomy at Aarhus University Hospital, where a 2-step implementation strategy has been used. In this retrospective observational cohort study a total of 369 patients with esophagus or gastroesophageal cancers underwent esophagectomy from September 1st, 2016 to July 31st, 2021 in a single high-volume tertiary institution. Totally minimally invasive Ivor Lewis esophagectomy was performed by experienced minimal invasive surgeons in 120 of the cases. The study presents the complication rates of the TIME patients in the implementation phase. Anastomotic leakage occurred in 7.5% of the cases and pneumonia occurred in 5.8% of the cases. The lymph node count reached 16 or more in 94.3% of the cases and R0-resection was performed in 98.3% of the cases. Textbook outcome for esophageal cancer surgery was achieved in 45.8% of the patients. Hybrid minimal invasive esophagectomy can serve as a step towards totally minimally invasive esophagectomy. In our institution, major learning curve associated complications was avoided and a high level of cancer control was achieved by a 2-step implementation strategy in carefully selected patients.
| S-EPMC10636444 | biostudies-literature
Project description:Minimally invasive pancreatoduodenectomy (MIS PD) is a well reported technique with several advantages over conventional open pancreatoduodenectomy. In comparison to distal pancreatectomy, the adoption of MIS PD has been slow due to the technical challenges involved, particularly in the reconstruction phase of the pancreatojejunostomy (PJ) anastomosis. Hence, we introduce a low-cost model for PJ anastomosis simulation in MIS PD. We fashioned a model of a cut pancreas and limb of jejunum using economical and easily accessible materials comprising felt fabric and the modelling compound, Play-Doh. Surgeons can practice MIS PJ suturing using this model to help mount their individual learning curve for PJ creation. Our video demonstrates that this model can be utilized in simulation practice mimicking steps during live surgery. Our model is a cost-effective and easily replicable tool for surgeons looking to simulate MIS PJ creation in preparation for MIS PD.
| S-EPMC10700946 | biostudies-literature
Project description:The aim of the present study was to investigate the biomechanical effects of varying the length of a limited contact-dynamic compression plate (LC-DCP) and the number and position of screws on middle tibial fractures, and to provide biomechanical evidence regarding minimally invasive plate osteosynthesis (MIPO). For biomechanical testing, 60 tibias from cadavers (age at mortality, 20-40 years) were used to create middle and diagonal fracture models without defects. Tibias were randomly grouped and analyzed by biomechanic and three-dimensional (3D) finite element analysis. The differences among LC-DCPs of different lengths (6-, 10- and 14-hole) with 6 screws, 14-hole LC-DCPs with different numbers of screws (6, 10 and 14), and 14-hole LC-DCPs with 6 screws at different positions with regard to mechanical characteristics, including compressing, torsion and bending, were examined. The 6-hole LC-DCP had greater vertical compression strain compared with the 10- and 14-hole LC-DCPs (P<0.01), and the 14-hole LC-DCP had greater lateral strain than the 6- and 10-hole LC-DCPs (P<0.01). Furthermore, significant differences in torque were observed among the LC-DPs of different lengths (P<0.01). For 14-hole LC-DCPs with different numbers of screws, no significant differences in vertical strain, lateral strain or torque were detected (P>0.05). However, plates with 14 screws had greater vertical strain compared with those fixed with 6 or 10 screws (P<0.01). For 4-hole LC-DCPs with screws at different positions, vertical compression strain values were lowest for plates with screws at positions 1, 4, 7, 8, 11 and 14 (P<0.01). The lateral strain values and vertical strain values for plates with screws at positions 1, 3, 6, 9, 12 and 14 were significantly lower compared with those at the other positions (P<0.01), and torque values were also low. Thus, the 14-hole LC-DCP was the most stable against vertical compression, torsion and bending, and the 6-hole LC-DCP was the least stable. However, the use of 14 screws with a 14-hole LC-DCP provided less stability against bending than did 6 or 10 screws. Furthermore, fixation with distributed screws, in which some screws were close to the fracture line, provided good stability against compression and torsion, while fixation with screws at the ends of the LC-DCP provided poor stability against bending, compressing and torsion.
| S-EPMC5526180 | biostudies-other
Project description:Minimally invasive esophagectomy is increasingly performed for the treatment of esophageal cancer, but it is unclear whether hybrid minimally invasive esophagectomy (HMIE) or totally minimally invasive esophagectomy (TMIE) should be preferred. The objective of this study was to perform a meta-analysis of studies comparing HMIE with TMIE. A systematic literature search was performed in MEDLINE, Embase, and the Cochrane Library. Articles comparing HMIE and TMIE were included. The Newcastle-Ottawa scale was used for critical appraisal of methodological quality. The primary outcome was pneumonia. Sensitivity analysis was performed by analyzing outcome for open chest hybrid MIE versus total TMIE and open abdomen MIE versus TMIE separately. Therefore, subgroup analysis was performed for laparoscopy-assisted HMIE versus TMIE, thoracoscopy-assisted HMIE versus TMIE, Ivor Lewis HMIE versus Ivor Lewis TMIE, and McKeown HMIE versus McKeown TMIE. There were no randomized controlled trials. Twenty-nine studies with a total of 3732 patients were included. Studies had a low to moderate risk of bias. In the main analysis, the pooled incidence of pneumonia was 19.0% after HMIE and 9.8% after TMIE which was not significantly different between the groups (RR: 1.46, 95% CI: 0.97-2.20). TMIE was associated with a lower incidence of wound infections (RR: 1.81, 95% CI: 1.13-2.90) and less blood loss (SMD: 0.78, 95% CI: 0.34-1.22) but with longer operative time (SMD:-0.33, 95% CI: -0.59--0.08). In subgroup analysis, laparoscopy-assisted HMIE was associated with a higher lymph node count than TMIE, and Ivor Lewis HMIE was associated with a lower anastomotic leakage rate than Ivor Lewis TMIE. In general, TMIE was associated with moderately lower morbidity compared to HMIE, but randomized controlled evidence is lacking. The higher leakage rate and lower lymph node count that was found after TMIE in sensitivity analysis indicate that TMIE can also have disadvantages. The findings of this meta-analysis should be considered carefully by surgeons when moving from HMIE to TMIE.
| S-EPMC7455468 | biostudies-literature
Project description:Melatonin is a key hormone in the regulation of circadian rhythms of vertebrates, including songbirds. Understanding diurnal melatonin fluctuations and being able to reverse or simulate natural melatonin levels are critical to investigating the influence of melatonin on various behaviors such as singing in birds. Here we give a detailed overview of natural fluctuations in plasma melatonin concentration throughout the night in the zebra finch. As shown in previous studies, we confirm that "lights off" initiates melatonin production at night in a natural situation. Notably, we find that melatonin levels return to daytime levels as early as two hours prior to the end of the dark-phase in some individuals and 30 min before "lights on" in all animals, suggesting that the presence of light in the morning is not essential for cessation of melatonin production in zebra finches. Thus, the duration of melatonin production seems not to be specified by the length of night and might therefore be less likely to directly couple circadian and annual rhythms. Additionally, we show that natural melatonin levels can be successfully simulated through a combination of light-treatment (daytime levels during subjective night) and the application of melatonin containing skin-cream (nighttime levels during subjective day). Moreover, natural levels and their fluctuation in the transition from day to night can be imitated, enabling the decoupling of the effects of melatonin, for example on neuronal activity, from sleep and circadian rhythmicity. Taken together, our high-resolution profile of natural melatonin levels and manipulation techniques open up new possibilities to answer various melatonin related questions in songbirds.
| S-EPMC4846806 | biostudies-literature
Project description:BackgroundLearning curves are inevitably encountered when first implementing an innovative and complex surgical technique. Nevertheless, a cluster of failures or complications should be detected early, but not deter learning, to ensure safe implementation. Here, we aimed to examine the presence and impact of learning curves on outcome after robotic-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB).MethodsA retrospective analysis of the first 300 RA-MIDCAB surgeries between July 2015 and December 2020 was performed. Learning curves were obtained via logarithmic regression for surgical time. Cumulative sum (CUSUM) analysis was performed for (I) major complications including MI, stroke, repeat revascularization, and mortality, and (II) other complications, including prolonged ventilation, pneumonia, pleura puncture, lung herniation, pericarditis, pleuritis, arrhythmia, wound complications, and delirium. Expected and unacceptable rates were set at 12% and 20%, respectively, for major complications, and at 40% and 60% for other complications, based on historical data in conventional coronary artery bypass grafting (CABG).ResultsDemographic characteristics did not differ between terciles, except for more smokers in the first tercile, and less hypercholesterolemia and more complex procedures in the third tercile. The mean surgical time for all operations was 258±81 minutes, ranging from 127 to 821 minutes. A learning curve was only observed in the first tercile. Subgroup analysis revealed that this learning curve was only observed for procedures consisting of single internal mammary artery (SIMA) with 1 or 2 distal anastomoses but not with bilateral internal mammary arteries (BIMA) or more than 2 distal anastomoses. CUSUM analysis showed that the cumulative rate of major and other complications never crossed the lines for unacceptable rates. Rather, the lower 95% confidence boundary was crossed after 50 cases, indicating improvement in safety.ConclusionsThese results suggest that integration of RA-MIDCAB in the surgical landscape can be safely achieved and complication rates can quickly be reduced below those expected in traditional CABG. Collective experience plays a key role in overcoming the learning curve when more complex procedures and cases are introduced.
| S-EPMC8339757 | biostudies-literature
Project description:Spine metastases affect more than 70% of terminal cancer patients that eventually suffer from severe pain and neurological symptoms. Nevertheless, in the overwhelming majority of the cases, a spinal metastasis represents just one location of a diffuse systemic disease. Therefore, the best practice for treatment of spinal metastases depends on many different aspects of an oncological disease, including the assessment of neurological status, pain, location, and dissemination of the disease as well as the ability to predict the risk of disease progression with neurological worsening, benefits and risks associated to treatment and, eventually, expected survival. To address this need for a framework and algorithm that takes all aspects of care into consideration, we reviewed available evidence on the multidisciplinary management of spinal metastases. According to the latest evidence, the use of stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT) for spinal metastatic disease is rapidly increasing. Indeed, aggressive surgical resection may provide the best results in terms of local control, but carries a significant rate of post-surgical morbidity whose incidence and severity appears to be correlated to the extent of resection. The multidisciplinary management represents, according to current evidence, the best option for the treatment of spinal metastases. Noteworthy, according to the recent literature evidence, cases that once required radical surgical resection followed by low-dose conventional radiotherapy, can now be more effectively treated by minimally invasive spinal surgery (MISS) followed by spine SRS with decreased morbidity, improved local control, and more durable pain control. This combination allows also extending this standard of care to patients that would be too sick for an aggressive surgical treatment.
| S-EPMC6761912 | biostudies-literature
Project description:ObjectiveTo evaluate oncologic outcomes of minimally invasive radical hysterectomy (RH) in early cervical cancer before and after the application of parametrial invasion (PMI) criterion on magnetic resonance imaging (MRI) and vaginal colpotomy (VC).MethodsA total of 216 International Federation of Gynecology and Obstetrics stage IB-IIA cervical cancer patients who underwent minimally invasive RH was identified between April 2006 and October 2018. Patients were classified into the pre-PMI intracorporeal or VC (IVC) (n=117) and post-PMI VC groups (n=99). In the pre-PMI IVC group, PMI criterion (intact stromal ring) on MRI was not applied and the patients received IVC. In the post-PMI VC group, surgical candidates were selected using the PMI criterion on MRI and all patients received VC only. Oncologic outcomes and prognostic factors associated with disease recurrence were analyzed.ResultsThe rate of positive vaginal cuff margins in the pre-PMI IVC group was higher than that in the post-PMI VC group (11.1% vs. 1.0%, p=0.003). Two-year disease-free survival was different between the 2 groups (84.5% in pre-PMI IVC vs. 98.0% in post-PMI VC groups, p=0.005). Disrupted stromal ring on MRI (hazard ratio [HR]=20.321; 95% confidence interval [CI]=4.903-84.218; p<0.001) and intracorporeal colpotomy (HR=3.059; 95% CI=1.176-7.958; p=0.022) were associated with recurrence.ConclusionThe intact cervical stromal ring on MRI might identify the low-risk group of patients in terms of PMI and lymphovascular/stromal invasion in early cervical cancer. Minimally invasive RH should be performed in optimal candidates with an intact stromal ring on MRI, using VC.
| S-EPMC6918891 | biostudies-literature
Project description:A modification of range of motion of the knee can significantly change a patient's quality of life. In general, range of motion of 0° to 125° is adequate for most activities of daily life. The rate of knee arthrofibrosis after ligament reconstruction is reported to be between 0% and 4%; after tibial fracture due to high-energy trauma, the rate is about 7%, with an undetermined incidence after limb lengthening. The purpose of this study was to describe a modification of the operative technique of Judet. We describe minimally invasive quadricepsplasty in 4 steps, aiming to obtain an end result with an arc of movement of at least 120° to 130°. We believe that our technique is a good option for the treatment of the stiff knee, having low morbidity and being an easy method to perform.
| S-EPMC6472174 | biostudies-literature