Conventional Instrumentation Systems Research Articles

Learning curve of the 67 steps of conventional total knee replacement: an experimental study.

Three trainees with different expertise performed the steps of TKR on bone models. One senior supervisor recorded the outcomes, including operative time and errors made during the experiment. Errors were further categorized into correctable and uncorrectable ones. Most of the errors were made by the trainee with the least experience during the stages of femoral cutting, sizing, and rotation. The first-year resident has taken 1.25 times longer than the fellow in preparing the femur and 1.11 times in preparing the tibia. The recorded mistakes were 28, 8, and 3 for the first-year resident, the second-year resident, and the fellow surgeon, respectively. Fifteen of the mistakes were uncorrectable, and none of them were from the senior surgeon. The results of this study highlight the type of errors made by different trainees. This shows the steep learning curve of conventional instrumentation systems for trainees. Increasing cognitive skills and applying computer-assisted technologies may help trainees overcome this steep learning curve.

Comparison of navigation systems for total knee arthroplasty: A systematic review and meta-analysis.

Component alignment is a crucial factor affecting the clinical outcome of total knee arthroplasty (TKA). Accelerometer-based navigation (ABN) systems were developed to improve the accuracy of alignment during surgery. This study aimed to compare differences in component alignment, clinical outcomes, and surgical duration when using conventional instrumentation (CONI), ABN, and computer navigation (CN) systems. A comprehensive literature search was carried out using the Web of Science, Embase, PubMed, and Cochrane databases. Articles that met the eligibility criteria were included in the study. Meta-analyses were performed using the Cochrane Collaboration Review Manager based on Cochrane Review Method. The variables used for the analyses were postoperative clinical outcome (PCO), surgical duration, and component alignment, including the hip-knee-ankle (HKA) angle, coronal femoral angle (CFA), coronal tibial angle (CTA), sagittal femoral angle (SFA), sagittal tibial angle (STA), and the outliers for the mentioned angles. The mean difference (MD) was calculated to determine the difference between the surgical techniques for continuous variables and the odds ratio (OR) was used for the dichotomous outcomes. The meta-analysis of the CONI and ABN system included 18 studies involving 2,070 TKA procedures, while the comparison of the ABN and CN systems included 5 studies involving 478 TKA procedures. The results showed that the ABN system provided more accurate component alignment for HKA, CFA, CTA, and SFA and produced fewer outliers for HKA, CFA, CTA, and STA. However, while the ABN system also required a significantly longer surgical time than the CONI approach, there was no statistical difference in PCO for the two systems. For the ABN and CN systems, there was no statistical difference in all variables except for the ABN system having a significantly shorter surgical duration. There was no significant difference in the accuracy of component alignment between the ABN and CN systems, but the ABN approach had a shorter surgical duration and at lower cost. The ABN system also significantly improved the accuracy of component alignment when compared to the CONI approach, although the surgery was longer. However, there was no significant difference in PCO between the CONI, ABN, and CN systems.

Comparison of the logistics between the conventional instruments and patient-specific templating in total knee replacement in the low-income setting

BackgroundTotal knee replacement (TKR) is a complex operation and its conventional instrumentation system has around 300 pieces to perform and more than 50 technical steps. New techniques were introduced, such as patient-specific instrumentation (PSI), robotics, and navigation to facilitate the TKR operation. This study aims to compare the logistics between conventional instrumentation and patient-specific templating (PST) in the low-income setting. MethodsWe compared the logistics for the conventional and the PST techniques while performing TKR. The comparison included the number of instruments and trays, equipment delivery, packaging, sterilization, intraoperative setup, and post-operative handling. ResultsThe surgical trays to complete one conventional TKR were 6–12 trays while for the PST, only one tray was needed. Conventional instruments can reach the hospital in 24 h while the delivery time of the PST may take from 3 to 5 days. The time needed to sterilize the conventional could be done overnight in the small hospitals as compared to a few hours in PST. In addition, PST has no special postoperative steps, unlike the conventional, which requires washing, delivery to a storage facility, re-washing, decontamination, packing, and storing till the next surgery. ConclusionThe logistics for conventional instruments are more complex. Although there was no cost-effectiveness analysis, it has been observed that the PST technique has a positive effect on rationalizing resources by consuming less time in the central sterilization unit and reducing the operating time.

La nouvelle instrumentation des prothèses unicompartimentales médiales Oxford® réduit-elle le risque de luxation des inserts en améliorant les rapports des pièces prothétiques ? Une étude cas contrôle

IntroductionThe recently introduced Microplasty® system is an upgrade of conventional phase III instrumentation. However, little is known of its impact on the position of the implant following the Oxford® mobile-bearing unicompartmental knee arthroplasty (UKA). This study investigated whether the Microplasty® instrumentation system can improve the positioning of the implant and reduce the rate of early failure. HypothesisMicroplasty® provides a better positioning and decreases the rate of dislocation. Materials and methodsThe medical records and radiographs of 82 consecutive Oxford® UKAs were reviewed retrospectively. The radiographic parameters and prevalence of early failure of 41 UKAs performed with the Microplasty® system and 41 UKAs using the conventional instrumentation system were compared. Both groups were comparable in terms of demographics and preoperative status. ResultsThe femoral components in the Microplasty® group were more contiguously placed and more convergent in relation to the tibial components compared to the conventional instrumentation system (P<0.01). The frequency of bearing dislocation was lower in the Microplasty® group (P=0.04). A wide gap and the angle between components were associated with an increased risk of bearing dislocation. ConclusionThe Microplasty® instrumentation system consistently placed the femoral and tibial components in more contiguous and convergent positions. Such changes in position decreased the risk of bearing dislocations by reducing the space available for bearing rotation. Level of evidenceLevel III, case control study.

Are the Oxford® medial unicompartmental knee arthroplasty new instruments reducing the bearing dislocation risk while improving components relationships? A case control study

IntroductionThe recently introduced Microplasty® system is an upgrade of conventional phase III instrumentation. However, little is known of its impact on the position of the implant following the Oxford® mobile-bearing unicompartmental knee arthroplasty (UKA). This study investigated whether the Microplasty® instrumentation system can improve the positioning of the implant and reduce the rate of early failure. HypothesisMicroplasty® provides a better positioning and decreases the rate of dislocation. Materials and methodsThe medical records and radiographs of 82 consecutive Oxford® UKAs were reviewed retrospectively. The radiographic parameters and prevalence of early failure of 41 UKAs performed with the Microplasty® system and 41 UKAs using the conventional instrumentation system were compared. Both groups were comparable in terms of demographics and preoperative status. ResultsThe femoral components in the Microplasty® group were more contiguously placed and more convergent in relation to the tibial components compared to the conventional instrumentation system (P<0.01). The frequency of bearing dislocation was lower in the Microplasty® group (P=0.04). A wide gap and the angle between components were associated with an increased risk of bearing dislocation. ConclusionThe Microplasty® instrumentation system consistently placed the femoral and tibial components in more contiguous and convergent positions. Such changes in position decreased the risk of bearing dislocations by reducing the space available for bearing rotation. Level of evidenceLevel III, case control study.

A wireless high-frequency anemometer instrumentation system for field measurements

Field measurement of wind characteristics is of great significance for the wind engineering community. High-frequency anemometers such as ultrasonic anemometers are widely used to obtain the high-frequency fluctuating wind speed time history. However, conventional instrumentation systems may suffer from low efficiency, non-real time transmission and higher maintenance cost, and thus are not very appropriate in the field measurement of strong winds in remote areas such as mountain valleys. In order to improve the field measurement performance in those remote areas, a wireless high-frequency anemometer instrumentation system for field measurement has been developed. In this paper, the architecture of the proposed instrumentation system, and measured data transmission and treatment will be presented firstly. Then a comparison among existing instrumentation systems and the proposed one is made. It shows that the newly-developed system has considerable advantages. Furthermore, the application of this system to the bridge site located in the mountain valley is discussed. Finally, typical samples of measured data from this area are presented. It can be expected that the proposed system has a great application potential in the wind field measurement for remote areas such as the mountainous or island or coastal area, and hazardous structures such as ultra-voltage transmission tower, due to its real-time transmission, low cost and no manual collection of data and convenience.

A Simple Instrumentation System for Large Structure Vibration Monitoring

A conventional instrumentation systems in monitoring vibration of large-scale infrastructure building such as bridges, railway, and others structural building, generally has a complex design. Makes it simple would be very useful both in terms of low-cost and easy maintenance. To make system become simple, low cost, and easy in maintenance, this paper proposes a distributed network for implementation system. The system consists of field bus topology, using single-master multi-slave architecture. Master is a control unit, built based on a PC equipped with RS-485 interface. Slave is a sensing unit; each slave is built by integrating a 3-axis vibration sensor within a microcontroller based data acquisition system. Vibration sensor is designed using the main components of a MEMS accelerometer. The software is developed for two functions; a control system hardware and a data processing. To verify performance of the developed instrumentation system, several laboratory tests have been performed. The result shows that the system has good performance.

Clinical and radiographic outcomes of Image-Based Computer-Assisted Total Knee Arthroplasty: An Evidence-based Evaluation

Conventional instrumentation systems have limited accuracy in determining the crucial landmarks needed for alignment in total knee arthroplasty (TKA). Given this, the image-based navigation system was introduced to improve the accuracy of implantation of components into the femur and tibia. PubMed, EMBASE, Web of Science, and Evidence-Based Medicine databases were electronically searched to identify eligible studies published until October 2008. A systematic review and meta-analysis of 6 randomized/quasi-randomized controlled trials that compared image-based navigation and conventional techniques was conducted. The operative time was longer in the navigation group in 3 studies. Moreover, there was a higher rate of achieving mechanical leg axis within the range of 3° deviation in patients undergoing navigated TKA. However, all studies between the 2 groups were similar in range of motion, knee scores, and postoperative complication rates at the last follow-up. Overall, these short-term follow-up trials show that there were similar early clinical outcomes between image-based navigation and conventional techniques.

Précision des coupes osseuses dans l’arthroplastie totale du genou à l’aide d’un ancillaire conventionnel: Trois cent poses consécutives de prothèses Innex ®

Purpose of the study Short-term functional results and long-term outcome in terms of stability and wear greatly depend on the precision of the bone cuts. We wanted to know whether conventional ancillaries are still competitive in terms of accuracy in comparison with computer-assisted navigation systems. A few comparative studies favor navigation, but have generally only included a small number of patients. We studied radiographically a prospective consecutive series of 300 total knee prostheses (Innex®, Zimmer) implanted with the conventional technique by the same operator. Material and methods A telegonometric view in the upright position and a short lateral view were obtained in all patients. In the AP view, implants were measured in comparison with the mechanical axis of the femur (F) and the tibia (T). On the lateral view, the prosthesis-tibial shaft angle (PT) was measured from the proximal portion of the tibial shaft and the prosthesis-femoral shaft angle (PF) from the distal portion of the femur. The same operator made all measurements using the same optimal conditions. The series included 178 women and 122 men, mean age 72 ± 8 years who presented genu varum (n = 248 knees) and genu valgum (n = 52 knees): degenerative disease (n = 238), polyarthritis (n = 4), hemophilic arthropathy (n = 3), necrosis (n = 3), revision of unicompartmental prosthesis (n = 8), and osteotomy (n = 44). Results The standard x-ray protocol was performed at two months in all patients. The mechanical axis (HKA) was 179.4 ± 2.4̊ (range 173-186̊) and was ± 3̊ in 87% of knees with no difference for varum and valgum. F was 90.1 ± 1.4̊ (87-95), with ± 3̊ for 98.7%. T was 89.3 ± 1.5̊ (85-94) with ± 3̊ for 95.6%. PF was 88.6 ± 1.6̊ (84-93) for 87%, PT was 87 ± 2̊ (81-93) with ± 3̊ for 94%. The four cuts were within ± 3̊ for 227 prostheses (77%), within ± 2̊ for 156 (52%) and within ± 1̊ for 56 (18%). Measurements made again one year after implantation for 203 knees gave the same results. Operative time for implantation was 68 ± 23 minutes for implantation and 85 ± 23 minutes including complete closure (less than 60 minutes for 68 knees). Discussion The accuracy of each cut was satisfactory on average with a small standard deviation. Recent data in the literature show that the accuracy in our series is comparable with that obtained currently with navigation systems. In light of this experience, it can be seen that better precision can be achieved for each of the cuts. Conclusion The accuracy of conventional instrumentation systems is still comparable with that obtained with computer-assisted surgery. The purpose of this study was not to question the benefit of navigation, but to establish a basis upon which progress can be measured. The results enabled a more realistic comparison of the precision of navigation systems and also can be comforting for operators still using conventional ancillaries.

Integrated Virtual Instrumentation and Wireless Monitoring for Infrastructure Diagnostics

This article presents the research, development, and field testing of a computer-controlled integrated instrumentation and monitoring system for rapid-response infrastructure testing and evaluation. The system eliminates both stand-alone laboratory benchtop equipment sets and cable-based, hard-wired, on-site networking for individual sensors. A software-based virtual instrumentation program package is developed to replace conventional data acquisition and monitoring equipment and control all system components through a user-friendly graphical user interface. In addition, a multiple-channel wireless site network throughout the structure is developed to substitute cable networking and integrated in the modular system. Concept and design characterizations, validation testing, and practical field use for experimental live-load bridge test monitoring are also presented. The tests verify the computer-controlled operation of the system integrating virtual instrumentation with multiple-channel wireless site network. The results are compared with conventional instrumentation system and found to be consistent.

Cotrel-Dubousset instrumentation in adults. A preliminary report.

In an attempt to assess the value of the Cotrel-Dubousset (CD) system for adult spinal disorders, the first 50 adult cases performed at Johns Hopkins were reviewed. Treatment of adult scoliosis with the CD system yielded results comparable to standard techniques. Curve correction was directly proportional to the preoperative flexibility with no loss of correction in any case. All patients went on to a solid arthrodesis, with only three patients requiring the use of postoperative orthoses. Operative time was initially prolonged during the phase of acquiring expertise with the system; however, blood loss and hospitalization were comparable. In both the scoliosis and kyphosis groups instrumentation and fusion incorporated the same number of levels as would have been required for conventional instrumentation systems. In the spondylolisthesis, tumor and trauma groups a total of 88 transpedicle screws was used in 18 patients without neurologic complications. Pedicle screws provided a fixation alternative in cases requiring laminectomies. In the 25 cases with tumors, spondylolisthesis, and trauma, CD instrumentation reduced the number of vertebral levels required for fixation. Compared to Harrington or Luque systems, the average number of motion segments spared per patient was 1.3 in the spondylolisthesis group, 2 in the tumor group and 2.1 in the trauma group. This study suggests that the CD system, although initially developed for idiopathic adolescent scoliosis, is versatile and can be safely and effectively applied to a variety of adult spinal conditions. In cases of spinal pathology due to neoplasm, spondylolisthesis, and trauma, CD instrumentation with the option of transpedicle fixation appeared to offer significant advantages over conventional methods, and an average of 1.6 lumbar motion segments could be preserved per case.