Does two dimensional templating allow for the use of reduced-size ancillaries in total hip arthroplasty?

PURPOSE: Rising costs in healthcare for total hip arthroplasty (THA) mean that new solutions must be considered, such as the use of single-use ancillaries (SUA). The goal of this study was to assess the accuracy of 2D templating in primary THA for the use of reduced-size SUA. Our hypothesis was that the accuracy of 2D templating in primary THA would be higher than 95%, give or take two sizes. METHOD: This single-centre prospective study included all primary THAs performed over two years. Templating was carried out using 2D templating on anteroposterior pelvic X-rays. The template sizes were compared to the implant sizes. The primary endpoint was the rate of coincidence between digitally templated estimates and the actual implant sizes. The secondary endpoint was the difference of accuracy based on patient parameters. RESULTS: We analysed 512 cases of THA. Accuracy within two sizes was 96.9% for acetabular implants and 98.5% for femoral implants. Accuracy was below the 95% threshold only in patients under 55 and over 85 years old. A BMI above 30.0 kg/m2 significantly reduced accuracy but did not fall below the 95% threshold. The operated hip, the type of implant, and the operative indication did not significantly influence templating accuracy. CONCLUSION: Using reduced-size SUA with five rasps and five reamers depending on template sizes means that THA can be performed in more than 95% of cases allowing the use of compact single use ancillaries.

[Fillet flap transfer as alternative to conventional lower limb amputation]. / Filetlappentransfer als Alternative zu konventionellen Amputationen der unteren Extremität.

BACKGROUND: The fitting of a prosthesis after lower limb amputation is associated with several challenges. Skeletal stump-prosthesis interfaces and selective nerve transfer can partially overcome these but are also associated with new impairments that emphasize the necessity of innovative approaches. The concept of so-called spare part surgery with the use of fillet flaps could play an important role in this respect. OBJECTIVE: An overview of the classical prosthesis-associated discomforts, advantages and disadvantages of treatment strategies and presentation of alternative surgical concepts. MATERIAL AND METHODS: A selective literature search was carried out considering the experiences of the authors and perspectives with respect to the advantages and disadvantages of the surgical treatment options. Furthermore, a clinical case is presented. RESULTS AND CONCLUSION: The transfer of the sole of the foot as a fillet flap to the weight-bearing region of the amputation stump offers a number of benefits, such as creating a fully weight-bearing stump, prevention of neuralgia, preserved sensation and conservation of the body image. As long as the calcaneal region is not impaired, this technique can be performed in amputations below as well as above the knee. The question of whether parts of the bone should be included in the transfer must be individually evaluated for each patient. This approach enables optimization of the residual limb stump for the subsequent fitting of a prosthesis for the patient.

Comparing Self-Fitting Strategies for Over-the-Counter Hearing Aids: A Crossover Clinical Trial.

Importance: Fewer than 20% of US adults with hearing loss use hearing aids due to barriers like high cost. Over-the-counter (OTC) hearing aids offer a potential solution, incorporating self-fitting strategies via smartphone apps. Self-fitting strategies have been validated for Food and Drug Administration (FDA)-approved OTC hearing aids compared with prescription-based approaches. However, no direct comparative analysis exists between in situ audiometry and self-adjustment strategies using self-fitting OTC (OTC-SF) hearing aids. Objective: To compare self-adjustment and in situ audiometry self-fitting strategies in OTC-SF hearing aids for adults with mild to moderate hearing difficulties. Design Settings and Participants: A crossover, within-participant pseudorandomized clinical trial was conducted between July and November 2023. Twenty-eight participants were pseudo-randomly assigned to 1 of the 2 self-fitting strategies, and they experienced both interventions for 4 consecutive weeks. Interventions: The self-adjustment group manually adjusted settings, including overall gain and spectral tilt, using Lexie B2 hearing aids, while the in situ audiometry group used Lexie B2 Plus hearing aids (Lexie Hearing by hearX Group), with an automated fitting based on in situ tests conducted through the app. Main Outcomes and Measures: The primary outcome was Abbreviated Profile of Hearing Aid Benefit (APHAB). Secondary outcomes were International Outcome Inventory for Hearing Aids (IOI-HA), speech-in-noise tests (DIN and QuickSIN), and real-ear measurements (REMs). Measures were completed at baseline and after the 4-week field trial using each strategy. Results: Twenty-eight participants (mean [SD] age, 60.2 [12.0] years) were included; 14 men and 14 women. Self-adjustment and in situ audiometry strategies produced no clinically meaningful differences across various outcome measures, including overall APHAB benefit (Cohen d = 0.2; 95% CI, -0.2 to 0.6) and overall IOI-HA satisfaction (Rosenthal r = 0.0; 95% CI, -0.3 to 0.2). Self-adjustment users reported higher satisfaction (Rosenthal r = -0.4; 95% CI, -0.6 to -0.1) and longer daily use (Rosenthal r = -0.3; 95% CI, -0.5 to 0.0) compared with those using in situ audiometry. No clinically meaningful differences were observed in speech-in-noise benefit and real-ear measurements. Conclusion and Relevance: In this clinical trial of OTC-SF hearing aids, self-adjustment and in situ audiometry strategies resulted in similar outcomes. However, self-adjustment may produce higher satisfaction and longer daily use, highlighting the potential advantages of active user involvement in the fitting process. Further investigation is needed for long-term outcomes. Trial registration: ClinicalTrials.gov Identifier: NCT05782153.

Correlation between neural response telemetry measurements and fitting levels.

INTRODUCTION: The neural response telemetry (NRT) is a standard procedure in cochlear implantation mostly used to determine the functionality of implanted device and to check auditory nerve responds to the stimulus. Correlation between NRT measurements and subjective threshold (T) and maximum comfort (C) levels has been reported but results are inconsistent, and it is still not clear which of the NRT measurements could be the most useful in predicting fitting levels. PURPOSE: In our study we aimed to investigate which NRT measurement corresponds better to fitting levels. Impedance (IMP), Evoked Action Potential (ECAP) threshold and amplitude growth function (AGF) slope values were included in the study. Also, we tried to identify cochlear area at which the connection between NRT measurements and fitting levels would be the most pronounced. MATERIALS AND METHODS: Thirty-one children implanted with Cochlear device were included in this retrospective study. IMP, ECAP thresholds and AGF were obtained intra-operatively and 12 months after surgery at electrodes 5, 11 and 19 as representative for each part of cochlea. Subjective T and C levels were obtained 12 months after the surgery during cochlear fitting. RESULTS: ECAP thresholds obtained 12 months after surgery showed statistically significant correlation to both T and C levels at all 3 selected electrodes. IMP correlated with C levels while AGF showed tendency to correlate with T levels. However, these correlations were not statistically significant for all electrodes. CONCLUSION: ECAP threshold measurements correlated to T and C values better than AGF slope and IMP. Measurements obtained twelve months after surgery seems to be more predictive of T and C values compared to intra-operative measurements. The best correlation between ECAP threshold and T and C values was found at electrode 11 suggesting NRT measurements at mid-portion cochlear region to be the most useful in predicting fitting levels.

Intraoperative live measurement of femoral head size for acetabular cup sizing: simple, accurate, and green!

PURPOSE: Templating is the first step in achieving a successful total hip arthroplasty. We hypothesize that native head size is highly correlated with implanted cup size. Therefore, the purpose of this study is to look for a correlation between sizes of the intra-operative measurement of the femoral head and the implanted cup. METHODS: This is a monocentric observational study conducted from December 2018 till January 2023. All patients admitted for a primary total hip arthroplasty were included and retrospectively reviewed. Intra-operative femoral head measurement, radiographic femoral head diameter, templated (planned) cup size, and definitive implanted cup size were recorded. RESULTS: The sample included 154 patients (85 female and 69 males) with a mean age of 66.2 ± 10.4 years. There were 157 THA cases; 82 on the right side and 75 on the left side. The native head size and acetate template on digital radiographs were the most significantly positively correlated with cup size (P < 0.0001) while the radiological head size was significantly negatively correlated with cup size (P = 0.009). The implanted cup was on average 2 ± 2 mm bigger than the native head size measured intra-operatively. CONCLUSION: The native femoral head diameter measured intra-operatively is a simple and reliable tool to help the surgeons choose the proper size of the acetabular cup, preventing complications during surgery hence optimizing results post operatively. This technique would contribute to a more ecofriendly orthopaedic reconstructive surgery.

Prediction of Cochlear Implant Fitting by Machine Learning Techniques.

OBJECTIVE: This study aimed to evaluate the differences in electrically evoked compound action potential (ECAP) thresholds and postoperative mapping current (T) levels between electrode types after cochlear implantation, the correlation between ECAP thresholds and T levels, and the performance of machine learning techniques in predicting postoperative T levels. STUDY DESIGN: Retrospective case review. SETTING: Tertiary hospital. PATIENTS: We reviewed the charts of 124 ears of children with severe-to-profound hearing loss who had undergone cochlear implantation. INTERVENTIONS: We compared ECAP thresholds and T levels from different electrodes, calculated correlations between ECAP thresholds and T levels, and created five prediction models of T levels at switch-on and 6 months after surgery. MAIN OUTCOME MEASURES: The accuracy of prediction in postoperative mapping current (T) levels. RESULTS: The ECAP thresholds of the slim modiolar electrodes were significantly lower than those of the straight electrodes on the apical side. However, there was no significant difference in the neural response telemetry thresholds between the two electrodes on the basal side. Lasso regression achieved the most accurate prediction of T levels at switch-on, and the random forest algorithm achieved the most accurate prediction of T levels 6 months after surgery in this dataset. CONCLUSION: Machine learning techniques could be useful for accurately predicting postoperative T levels after cochlear implantation in children.

The accuracy of digital templating in the preoperative planning of total knee arthroplasties: A systematic review and meta-analysis.

AIMS: Accurately predicting the implant size in total knee arthroplasties could increase the efficiency of the operation, decrease the costs associated with the procedure and result in improved patient outcomes. To substantiate its continued use, digital templating must demonstrate itself to be an accurate tool in predicting component size in order for surgeons to confidently use it to optimize the procedure. METHODS: A systematic literature review was performed and identified 16 studies within the Pubmed, Ebsco and Ovid-Embase databases, with 1189 TKR prostheses included for analysis. A quality of evidence assessment was performed on each study depending on the study design. A random effects meta-analysis model was used to pool overall implant accuracy and the reported inter-rater agreement when performing digital templating and displayed in a forest plot. Meta-regression was used analyze potential factors that may affect the accuracy of digital templating. RESULTS: The pooled proportion of accurate templates with 0 margin of error was found to be 56% (52-61, 95CI), which increases to 96% (0.94-0.98, 95CI) when allowing for a 1 size margin of error. Subgroup analysis between femoral and tibial components concluded no statistically significant difference. CONCLUSIONS: This study supports the continued use of digital templating for planning total knee arthroplasties and recommends further subgroup analysis of patient age, body mass index and sex against accuracy. This review was registered in the International Prospective Register of Systematic Reviews Database under ID: CRD420222367461. No funding was provided for the completion of this systematic review. BACKGROUND: Templating in the preoperative planning of total knee arthroplasties is a vital step in ensuring maximum operative efficiency. A method that can accurately predict the required implant size within 1 size could improve theatre turnover, decrease costs and benefit patient outcomes. The current literature on the accuracy of digital templating in total knee arthroplasties lacks a systematic review calculating the overall accuracy of the process, this study aims to address this gap.

Estudio in vitro del ajuste de supraestructuras pasivadas sobre implantes múltiples / In vitro study of the adjustment of passivated suprastructures on multiple implants

Objetivo: Comparar dos procedimientos de soldadura convencionales empleando una aleación de Cr-Co, para co- nectar barras coladas seccionadas a ser fijadas sobre implantes. Materiales y métodos: A partir de un modelo maes- tro que representa un maxilar desdentado con cuatro implan- tes, se confeccionaron veinte (n=20) probetas seccionadas en tres partes. Se conformaron dos grupos, cada uno con diez (n=10) ejemplares. Una vez acondicionadas, fueron atornilla- das al modelo maestro. Su desajuste inicial se analizó utili- zando una lupa estereoscópica, con una cámara incorporada y un software. Las partes fueron soldadas empleando un pro- cedimiento diferente para cada grupo. Las correspondientes al Grupo I se invistieron en un block refractario a base de sílico-fosfato. Las del Grupo II se montaron en una estructu- ra metálica Clever Spider. El desajuste fue mensurado y los resultados procesados estadísticamente. El nivel de significa- ción fue establecido en p<0,05. Resultados: El Grupo I tuvo un desajuste inicial de 97,30±13,81µm y el Grupo II de 98,53±11,24µm. Luego de la soldadura, el Grupo I registró 98,53±17,17µm, 1,23µm mayor respecto al inicial. En el Grupo II se observó 103,13±17,61µm, 4,60µm por encima del original. Se analizaron mediante prue- ba t de Student; en ambos casos el resultado fue de p>0,05. Al comparar entre sí los grupos I y II, por medio de la prueba t y de comprobación no paramétrica de Mann-Whitney, se ob- servaron diferencias no significativas, p=0,41 y p=0,38 res- pectivamente (AU)

Aim: Compare two conventional welding procedures us- ing a Cr-Co alloy, to connect sectioned cast bars to be fixed on implants. Materials and methods: From a master model representing a toothless jaw with four implants, twenty (n=20) specimens sectioned into three parts were made. Two groups were formed, each with ten (n=10) specimens. Once conditioned, they were screwed to the master mod- el. Its initial mismatch was analyzed using a stereoscop- ic magnifier, with a built-in camera and a software. The parts were welded using a different procedure for each group. Those corresponding to Group I were invested in a refractory block based on silyl-phosphate. Those of Group II were mounted on a Clever Spider metal structure. The mismatch was measured, and the results processed statisti- cally. The level of significance was established at p<0.05. Results: Group I had an initial mismatch of 97.30 ±13.81µm, and Group II of 98.53±11.24µm. After welding, Group I registered 98.53±17.17µm, 1.23µm higher than the initial one. In Group II, 103.13±17.61µm was observed, 4.60µm above the original. They were analyzed using Stu- dent's t test; in both cases the result was p>0.05. When com- paring groups I and II, using the t-test and the Mann-Whitney nonparametric verification, non-significant differences were observed, p=0.41 and p=0.38 respectively. Conclusions: Under the conditions of this study, it was ob- served that the two welding methods analyzed were reliable for joining metallic superstructures without affecting their final fit (AU)

Management of Keratoconus With Corneal Rigid Gas-Permeable Contact Lenses.

ABSTRACT: Vision correction using a corneal rigid gas-permeable contact lens, which is relatively safe, easy to replace, and economical, is still the basis of the management for keratoconus. For eyes with keratoconus, two fitting strategies have traditionally been used in Japan: apical touch fitting with spherical lenses and parallel fitting with multicurve lenses. These two techniques have different success rates depending on the type and severity of keratoconus. Therefore, it is important to classify eyes with keratoconus into four types according to the shape of the cornea and select the prescription techniques according to this classification. If the corneal GPs prescribed by these fitting methods cannot be used because of mechanical irritation to the corneal epithelium, the "piggyback lens system" is an effective option. Furthermore, proper lens care must be instructed to patients to prevent contact lens-related complications and maintain visual function. If these fittings and introductions can be performed properly, corneal GPs can safely provide effective and comfortable vision for many patients with keratoconus, even for those with severe keratoconus.

Echocardiography-guided Cardiac Implantable Electronic Device Implantation to Reduce Device Related Tricuspid Regurgitation: A Prospective Controlled Study.

BACKGROUND: Endocardial leads of permanent pacemakers (PPM) and implantable defibrillators (ICD) across the tricuspid valve (TV) can lead to tricuspid regurgitation (TR) or can worsen existing TR with subsequent severe morbidity and mortality. OBJECTIVES: To evaluate prospectively the efficacy of intraprocedural 2-dimentional-transthoracic echocardiography (2DTTE) in reducing/preventing lead-associated TR. METHODS: We conducted a prospective randomized controlled study comparing echocardiographic results in patients undergoing de-novo PPM/ICD implantation with intraprocedural echo-guided right ventricular (RV) lead placement (Group 1, n=56) versus non-echo guided implantation (Group 2, n=55). Lead position was changed if TR grade was more than baseline in Group 1. Cohort patients underwent 2DTTE at baseline and 3 and/or 6 months after implantation. Excluded were patients with baseline TR > moderate or baseline ≥ moderate RV dysfunction. RESULTS: The study comprised 111 patients (74.14 ± 11 years of age, 58.6% male, 19% ICD, 42% active leads). In 98 patients there was at least one follow-up echo. Two patients from Group 1 (3.6%) needed intraprocedural RV electrode repositioning. Four patients (3.5%, 2 from each group, all dual chamber PPM, 3 atrial fibrillation, 2 RV pacing > 40%, none with intraprocedural reposition) had TR deterioration during 6 months follow-up. One patient from Group 2 with baseline mild-moderate aortic regurgitation (AR) had worsening TR and AR within 3 months and underwent aortic valve replacement and TV repair. CONCLUSIONS: The rate of mechanically induced lead-associated TR is low; thus, a routine intraprocedural 2DTTE does not have a significant role in reducing/preventing it.

Comparison of Cup Setting Angle Accuracy between Computed Tomography-Based and Computed Tomography-Free Navigation in the Same Patients with Crowe's Classification I or II Hip Dysplasia.

BACKGROUD: In total hip arthroplasty, the cup setting angle may affect the postoperative results. In recent years, both computed tomography-based navigation and computed tomography-free (imageless) navigation have been reported to produce high accuracy in cup installation; however, no direct comparison between these two methods has been performed. The present study aimed to directly compare the cup installation angle accuracy between computed tomography-based navigation and computed tomography-free navigation in patients with Crowe's classification stage I or II dysplastic osteoarthritis and to examine the factors affecting the cup installation accuracy. METHODS: Using both navigation systems for the same technique, primary total hip arthroplasty was performed by the same surgeon in 36 patients. A cup was installed using computed tomography-based navigation, and the installed cup was measured again using computed tomography-free navigation. We compared the error between the target angle and the intraoperative installation angle for each navigation method by performing statistical analyses. RESULTS: For computed tomography-based navigation, errors in the inclination and the anteversion angles compared to the target angle were 3.14° ± 1.55° and 1.47° ± 0.99°, respectively. For computed tomography-free navigation, the inclination and anteversion angle errors were significantly larger, i.e., 6.84° ± 4.78° and 5.43° ± 5.22°, respectively (p < 0.01). The inclination and anteversion angles of computed tomography-free navigation were correlated, and there were no significant factors influencing the error. CONCLUSIONS: Computed tomography-based navigation is more accurate for cup installation than computed tomography-free navigation. When using computed tomography-free navigation, it is necessary to add technical schemes before and during surgery to improve the cup installation accuracy.

Impact of Tibial Component Coronal Alignment on Knee Joint Biomechanics Following Fixed-bearing Unicompartmental Knee Arthroplasty: A Finite Element Analysis.

OBJECTIVE: Unicompartmental knee arthroplasty (UKA) has indicated a higher rate of revision than total knee arthroplasty (TKA). The success of UKA depends on UKA component alignment, fixation, and soft tissue integrity. The purpose of this study was to investigate the effects of different tibial component alignments in the coronal plane on the stress distribution in UKA. It was hypothesized that the stress distribution would approach native knee when the tibial component was neutrally positioned. METHODS: The left legs from two healthy volunteers were considered to represent the geometric native knee models. All bones within the knee joint were extracted from the three-dimensional (3D) computed tomography (CT). MRI was used to generate cartilage, menisci, and four major ligaments. The UKA components were virtually implanted in the medial compartment of the knee model using MIMICS. A total of five different configurations of UKA tibial obliquity in the coronal plane (neutral, 3° varus, 6° varus, 3° valgus, and 6° valgus) were adopted and investigated. Subject-specific inhomogeneous material properties of bones were used in the finite element analysis (FEA) model. The von Mises stress in the tibia platform and proximal tibia, and the load distribution between the medial and lateral compartments were extracted and compared among the five different configurations. RESULTS: The inhomogeneous material properties of the trabecular bone were closer to real physics than traditional homogeneous methods. Neutral and 3° varus alignments of the tibial component in the coronal plane have better stress distribution between medial and lateral compartment as healthy knee models, and less stress-shielding effects than other UKA configurations. The stress pathway under the medial tibia platform in neutral and 3° varus UKA configurations was similar and more obvious than the other three UKA configurations. Notably, the stress of the medial tibia platform in the 3° varus UKA models was more homogenous than the neutral UKA configuration. The 6° varus, 3° valgus, and 6° valgus UKA models had higher stress at the location of anterolateral and posterolateral tibia platform than other UKA configurations. CONCLUSION: Neutral or 3° varus positioned in the coronal plane for the tibial component could be the optimal alignment for UKA. Excessive varus or valgus obliquity in the coronal plane lead to significant differences in bone stress transfer and load distribution in the knee, and increase the risk of UKA failure.

Improved sizing with image-based robotic-assisted system compared to image-free and conventional techniques in medial unicompartmental knee arthroplasty.

AIMS: Ideal component sizing may be difficult to achieve in unicompartmental knee arthroplasty (UKA). Anatomical variants, incremental implant size, and a reduced surgical exposure may lead to over- or under-sizing of the components. The purpose of this study was to compare the accuracy of UKA sizing with robotic-assisted techniques versus a conventional surgical technique. METHODS: Three groups of 93 medial UKAs were assessed. The first group was performed by a conventional technique, the second group with an image-free robotic-assisted system (Image-Free group), and the last group with an image-based robotic arm-assisted system, using a preoperative CT scan (Image-Based group). There were no demographic differences between groups. We compared six parameters on postoperative radiographs to assess UKA sizing. Incorrect sizing was defined by an over- or under-sizing greater than 3 mm. RESULTS: There was a higher rate of tibial under-sizing posteriorly in the conventional group compared to robotic-assisted groups (47.3% (n = 44) in conventional group, 29% (n = 27) in Image-Free group, 6.5% (n = 6) in Image-Based group; p < 0.001), as well as a higher rate of femoral under-sizing posteriorly (30.1% (n = 28) in conventional group, 7.5% (n = 7) in Image-Free group, 12.9% (n = 12) in Image-Based group; p < 0.001). The posterior femoral offset was more often increased in the conventional group, especially in comparison to the Image-Based group (43% (n = 40) in conventional group, 30.1% (n = 28) in Image-Free group, 8.6% (n = 8) in Image-Based group; p < 0.001). There was no significant overhang of the femoral or tibial implant in any groups. CONCLUSION: Robotic-assisted surgical techniques for medial UKA decrease the risk of tibial and femoral under-sizing, particularly with an image-based system using a preoperative CT scan. Cite this article: Bone Joint J 2021;103-B(4):610-618.

A new technique for determining the rotational alignment of the tibial component during total knee arthroplasty.

BACKGROUND: We evaluated the effectiveness of our new technique "Range of motion-anatomical (ROM-A) technique" which is the combination of the self-positioning technique "Range of motion (ROM) technique" and the anatomical landmarks technique in determining the tibial component (TC) rotation alignment in total knee arthroplasty (TKA) using a navigation system. METHODS: This retrospective study included 103 knees who underwent TKA. The ROM-A technique was consisted of two steps. First, the TC was set and marked by the ROM technique in knee extension. Second, the TC was set according to the marking in the knee flexion and the component rotational angle relative to the anatomical tibial anteroposterior (AP) axis was adjusted between 0° and 10° external rotation using the navigation system. The rotational angle of TC relative to the anatomical AP axis was measured using postoperative computed tomography. Moreover, the hypothetical rotational angle of the TC in the ROM technique was calculated only from the intraoperative difference between the two techniques. RESULTS: The actual rotational angle by the ROM-A technique was externally rotated 3.0°, and the rotational outlier occurred in 3.0%. A significant difference in outlier rate was observed between the two techniques (p = 0.03). The hypothetical rotational angle of TC determined by the ROM technique (the first step only in the ROM-A technique) was externally rotated 4.6° and the TC rotational outlier (difference to AP axis: >10°) occurred in 11.7%. CONCLUSION: Using the ROM-A technique, the TC was finally fixed in almost all targeted rotational positions, and this technique could reduce the anatomical rotational outlier compared with the ROM technique.

Contemporary Robotic Systems in Total Knee Arthroplasty: A Review of Accuracy and Outcomes.

The success of total knee arthroplasty (TKA) depends on restoration of the stability and biomechanical efficiency of the native knee. The emergence of robotic surgical technologies has greatly increased the precision and reproducibility. We discuss contemporary robotic TKA systems by reviewing the features of the individual platforms, their accuracy, and the clinical outcomes. While early results suggest significant gains in patient outcomes, long-term evidence is still awaited from multicenter prospective clinical trials. Moreover, advances in this technology are needed to address knee laxity while individualizing the functional performance of each patient's new joint.

Knee Prosthesis in the Computer Era.

Over the past two decades, computer assistance has revolutionalized surgery and has enabled enormous advancements in knee prosthesis surgery. Total knee arthroplasty (TKA) is a hot topic of orthopaedic research. Reflecting population dynamics, its use continues to increase, especially in high demand populations. Therefore, efforts to achieve the best fit and precise alignment in TKA continue. Computer assistance is valuable for knee prosthesis surgeons in this regard. This manuscript investigated the use of computer assistance in knee prosthesis surgery. The effects of computer use on important facets of knee prosthesis surgery, such as precision, clinical aspects, and costs, were examined. Moreover, an overall review of the recent literature on the navigation and personalized cutting guides was conducted.

Accuracy of intraoperative estimation of femoral stem anteversion in cementless total hip arthroplasty by using a digital protractor and a spirit level.

BACKGROUND: The femoral component anteversion during surgery is traditionally assessed by a visual assessment of the surgeon and has proven to be imprecise. We sought to determine the accuracy of a digital protractor and a spirit level to measure the stem anteversion during cementless THA. METHODS: A prospective study was conducted among 107 patients (114 hips) who underwent primary cementless THA via posterolateral approach. A pipe with a spirit level was attached to the tibial tubercle and intermalleolar midpoint. While the leg was held perpendicularly to the floor, stem anteversion was estimated by 3 methods: method A by visual assessment; method B by a digital protractor alone; and method C by a digital protractor combined with a spirit level. The angles were compared with the true anteversion measured by postoperative CT scan. RESULTS: The average anteversion by method C (22.8° ± 6.9°, range -2° to 40°) was significantly lower than method A (24.6° ± 5.2°, range 0° to 30°) (p=0.033), but not different from the true anteversion (22.1° ± 8.2°, range -5.4° to 43.1°) (p=0.445). There were no significant differences between method B (23.2° ± 8.2°, range -4° to 45°) and method A, C or the true anteversion. The mean deviation of the intraoperative estimation from the true anteversion was 0.8° ± 3.7° (range -7.1° to 8.0°) by method C; 1.2° ± 5.1° (range -8.8° to 14.3°) by method B; and 2.5° ± 7.4° (range -19.0° to 16.0°) by method A. Estimation error within 5° was found in 107 hips (93.9%) with method C; 86 hips (75.4%) with method B; and 59 hips (51.8%) with method A. CONCLUSION: Accurate estimation of stem anteversion during cementless THA can be determined intraoperatively by the use of a digital protractor and a spirit level. TRIAL REGISTRATION: Thai Clinical Trials Registry ( TCTR 20180326003 ). Registered on 20 March 2018. Retrospectively registered.

Mid-term results of Biological Bentall using a larger valve implantation technique.

The present study evaluated our modified technique for placing a valve one size larger for Biological Bentall (Bio-Bentall) with a stented valve using a double sawing ring technique with a comparison to classical Bio-Bentall with a stent-less valve. Between December 2001 and July 2017, 44 patients (10 stent-less and 34 stented) with Bio-Bentall were included in this study. The early and mid-term surgical outcomes and re-operation free rates, including the structural valve deterioration (SVD) rate, were investigated. The mean follow-up duration was 69 months. There were two in-hospital mortalities in the stent-less group and one in the stented group, showing no significant difference. The survival at 1, 5 and 10 years was 80%, 50% and 30% in the stent-less group and 85%, 77% and 71% in the stented group, respectively, with a significant difference. There were no cases of SVD occurrence in either group. Freedom from re-operation at 1, 5 and 10 years was 100% at all points in the stent-less group and 100%, 96% and 96% in the stented group, respectively, without significance. The mean pressure gradient through the aortic valve according to the most recent echocardiogram was 8.1 mmHg in the stent-less group and 15.8 mmHg in the stented group, without significance. Our modified technique for Bio-Bentall showed a feasible short- and mid-term survival compared to classical stent-less Bio-Bentall. Both techniques had a good outcome concerning SVD occurrence and the re-operation-free rate with a low-pressure gradient in the aortic position.