Magnification of anteroposterior radiographs of the pelvis is variable. To improve the accuracy of templating, reliable and radiographer-friendly methods of scaling are necessary. We assessed two methods of scaling digital radiographs of the pelvis: placing a coin of known diameter in the plane of interest between the patient’s thighs, and using a caliper to measure the bony width of the pelvis. A total of 39 patients who had recently undergone hemiarthroplasty of the hip or total hip replacement were enrolled in the study. The accuracy of the methods was assessed by comparing the actual diameter of the head of the prosthesis with the measured on-screen value. The coin method was within a mean of 1.12% (0% to 2.38%) of the actual measurement, the caliper group within 6.99% (0% to 16.67%). The coin method was significantly more accurate (p < 0.001). It was also reliable and radiographer friendly. We recommend it as the method of choice for scaling radiographs of the pelvis before hip surgery

Motorcycle accident-related traffic accidents contribute significantly to the burden of orthopaedic injuries seen in the South African Healthcare system. Subsequent to the Covid-19 pandemic, there has been an increase in the number of delivery drivers on the roads of South Africa. Many of these delivery drivers have no formal employment contracts. We aim to describe the demographics and injury patterns in motorcyclists involved in time dependent delivery work in South Africa; and to quantify the cost to the state of their orthopaedic surgeries. We performed a consecutive case series study at all of the hospitals draining the study region over the period of one year. Epidemiological, clinical and cost to hospital data was collected from medical records, digital radiographs, theatre invoices and a dedicated patient questionnaire. Provisional. So far 41 delivery drivers were captured by the study over a period of 11 months. All drivers were male and the vast majority foreign nationals. 11 patients were polytraumatised and 5 required admission to an intensive care unit. The most common injury patterns were closed femur fractures (17) followed by tibial shaft fractures (13). The average cost of surgery was R35 049 and average cost of ward stay R44 882 at an average of 10 days admission in a general ward. Overall, an estimated total of R 3.1 million rand was spent on these injuries. Informally employed “app users” performing delivery work on motorcycles in South Africa have added a significant burden to the cost of state healthcare since 2020. The vast majority of these patients are foreign nationals who do not hold South African licences or health insurance. They are sustaining high energy injuries typical of motorcycle-car accidents and many of them are left with lifelong loss of function

Objective. Several researchers have reported that imageless navigation is a reliable technique and results in more precise cup placement compared to conventional freehand techniques, however, few studies have been reported about the accuracy of the femoral stem placement. The primary aim of this study was to evaluate the precision of an imageless navigation system in measuring the limb length change. The secondary aim was to evaluate LLD following imageless navigation THA with modified registration technique in semilateral decubitus position. Methods. The authors reviewed 66 cases receiving cementless THA with imageless navigation from September 2013 to December 2014. The radiographic limb length change measured from pre-operative and post-operative digital x-ray was compared with the intraoperative calculation by the navigation system. Postoperative LLD in unilateral cases and second operation of staged bilateral cases were also recorded. Results. The mean radiographic limb length change measured on digital x-ray was 17.4 mm (5 to 29.3, SD 5.7). The mean limb length change calculated by navigation system was 16.8 mm (3 to 28, SD 5.9). The mean paired difference was 2.27 mm (−6 to 8, SD 0.9). This difference was significant (p=0.01). There was significant correlation between LL change measured on digital x-ray and which were calculated by navigation system (r=0.95, p<0.001). The navigation system had an accuracy of within 1 mm of the radiographic measurement in 7.6% of cases, within 2 mm in 39.4% of cases and within 5 mm in 93.9% of cases. The mean postoperative LLD was 2 mm (0 to 7, SD 1.9), 92% were within 5 mm. Conclusion. This study showed that the imageless navigation THA with modified registration technique in semilateral decubitus position offered a precise limb length measurement and the results were very encouraging for clinical use to minimize LLD in THA

Digital templating was used in 50 patients who underwent THA using Merge Ortho software, Cedara. Clinical examination was performed first, to measure leg lengths and account for pelvic obliquity and flexion deformity. Good quality digital radiographs were obtained with anteroposterior and lateral views extending beyond the tip of the femoral component and the cement restrictor. A coin was placed on the ASIS to help in determining radiological magnification. Digital radiographs were saved in DICOM format and imported to EndoMap software system. A 6-step technique was used for templating as follows:. Radiographic assessment; looking at the quality of bone, amount of bone stock, dysplasia, osteophytes, and other abnormalities. Correction of magnification; following the specific instructions of the software, by measuring the diameter of the coin on the digital radiograph. 3. Measuring leg length discrepancy; the software system automatically calculated the leg length discrepancy, even in the presence of pelvic obliquity (Figure1). 4. Templating acetabular component; the desired cup was selected from the implant library after identifying important landmarks. The size and position was modified to fit the acetabulum and to restore the center of rotation of the hip, considering minimal bone removal and sufficient bone coverage laterally. Templating femoral component; the size and position of the desired stem was adjusted to fit the femoral canal, different offsets were compared to find the best match for the patient's original offset. Correction of leg length discrepancy and measuring length of neck resection; the height of the femoral stem was adjusted to correct any leg length discrepancy by placing the center of the head above the center of the cup by the same length of discrepancy. Then the level of the neck resection was marked at the level of the stem collar and the femoral neck cut was measured by a digital ruler from the tip of the lesser trochanter to the mark of neck resection. In case of leg length discrepancy, the height of the femoral neck cut was adjusted accordingly to compensate for the leg length discrepancy. For example, if the affected leg is 20 mm short, place the centre of the head 20 mm above the centre of the cup. Intraoperatively, the surgeon performed the femoral neck osteotomy at the level determined by preoperative templating. Postoperatively, the leg length was measured and compared to the preoperative leg length. Preoperatively, the leg length discrepancy ranged from 5 to 30 mm. In all cases, the leg was short on the side of THR (ipsilateral). Leg length discrepancy was adjusted in all THR cases. Postoperatively, the accuracy of the correction was found to be within 5 millimeters i.e. less than 5mm of shortening or lengthening). Intraoperatively, the level of femoral neck cut ranged from 1 to 44 mm. Digital templating is useful in adjusting leg length discrepancy. In addition, there were other benefits such as predication of femoral and acetabular implant sizes, restoration of normal hip centre, and optimization of femoral offset

Introduction. Low dose technology of an EOS scanner allows mechanical axis radiographs to be produced using a continuously moving x-ray emitting a thin beam to form a single image which includes all three joints, without the need for stitching. The aim of this study was to identify necessary improvements to enable effective interpretation of the radiographs, and to assess whether the quality of the radiographs varied by production method compared to a previous audit of CR and DR radiographs. Materials and Methods. 8 domains were identified based on a previous audit using the acronym MECHANIC each defining the qualities required for a radiograph to meet the criteria. 100 mechanical axis radiographs produced using conventional and digital methods were analysed in the original study to assess how many radiographs met the described criteria. The same criteria were amended and used to assess 123 different mechanical axis radiographs in the follow up study following the introduction of the EOS scanner, in which 77 were produced using EOS and 46 were produced using conventional and digital methods. Results. The second study showed improvement in 2 of the 6 domains being assessed and the result remained the same in 1 domain, with a mean change of +2%. There was a large increase in the number of radiographs with impeccable stitching in the second study due to the use of the EOS scanner. When comparing the methods of production, there were a greater percentage of EOS radiographs meeting the criteria for each domain compared to conventional and digital radiographs. Those produced using the EOS scanner had a mean 0.83% more radiographs meeting the criteria per domain. Conclusions. The overall quality of mechanical axis radiographs being produced has increased, but varies largely between the 6 domains. The EOS produced radiographs overall were of a greater quality than those produced using conventional and digital methods, but still had areas which required significant improvement

Background. Using digital X-rays to plan a hip replacement can cause problems with sizing and templating the prosthesis. Using an AP view of both hips is desirable as this allows the use of the sometimes unaffected contralateral hip for templating. Method. We devised a method of using a 20mm ball bearing as a marker positioned at the same depth as the greater trochanter, but between the patient's legs. Placing the marker between the patient's legs avoids the problem of the marker disappearing off the side of the X-ray, as is seen when placing the marker at the side of the obese patient. The marker is then used to calibrate the size of the digital X-ray. We used a hundred consecutive post-operative X-rays, comparing the size of the head of the femoral prosthesis used at surgery with the size measured pre-operatively using the marker. Results. There was a mean difference of 0, 3 mm between the size predicted using the marker and the actual prosthetic head used. Conclusion. This is an accurate and repeatable method of calibrating a digital X-ray to measure the required size of a prosthesis. NO DISCLOSURES

Introduction. The application of digital radiography in orthopaedic settings has facilitated the improvement in the retention and utilization of these images in pre and post-operative assessments [1]. In addition to the cost-effectiveness of such technology the use of digital imaging combined with advanced computer image processing software such as TraumaCadTM software system (TraumaCad, BRAINLAB, Westchester, IL, USA) can provide more accurate details about patients in total hip replacement arthroplasty (THA), a process traditionally called preoperative templating [2] by which intraoperative complications are minimized and overall surgical time is reduced[3]. In a study of 486 patients we demonstrated that patients demographic had significant effect on the outcome of the measurement and utilizing them in a predictive model had helped with improving the results [4]. In this study, we aimed to improve and optimize the proposed algorithm by utilizing more patients’ information and improving the model by using a nonlinear relationship. Our main hypothesis in this study was that the model would significantly predict the actual implant size based on the preoperative assessments. Method. We analyzed the outcome of digital radiographs of 1018 patients who were treated with THA. Minimum. Maximum. Mean. Std. Deviation. Templated Acetabulum Size. 44.00. 64.00. 54.12. 4.05. Height (m). 147.32. 202.20. 172.02. 10.73. Weight (kg). 39.10. 139.10. 84.44. 19.67. BMI. 15.48. 43.06. 28.33. 5.18. Acetabular Size. 44.00. 64.00. 54.25. 3.75. Digital radiographs were acquired in the anteroposterior view of the pelvis centered over the pubic symphysis. The hip was internally rotated 10° to 15°. We evaluated multiple interactions and nonlinear models and developed the most significant model based on the available clinical data. Results. We derived the following equation based on the model presented by the multiple regression analysis. Act[estimated]=−9.0467–0.35*Act[temp]+34.79*Height−0.35*Weight+1.32*BMI+0.01* (Act[temp])∘2–3.56*Height∘2–0.01*BMI∘2. In which Act[estimated] is the estimated size of acetabulum cup, Act[temp] is the preoperative templated acetabulum size from digital radiography, Height was in m and Weight was in kg. Figure 1 and Figure 2 depicts the residual assessments of the model. Figure 3 depicts the range of effects by each factor. Discussion. Patients’ specific data would improve the preoperative accuracy by more than 5% within one size of the actual acetabular component size. This improvement in accuracy translates into significant cost saving in THA cases as the cost of implant inventory could be significantly minimized. In our practice based on these assessments we use customized patients trays to reduce intraoperative costs

Radiostereometric analysis (RSA) allows for precise measurement of interbody distances on X-ray images, such as movement between a joint replacement implant and the bone. The low radiation biplanar EOS imager (EOS imaging, France) scans patients in a weight-bearing position, provides calibrated three-dimensional information on bony anatomy, and could limit the radiation during serial RSA studies. Following the ISO-16087 standard, 15 double exams were conducted to determine the RSA precision of total knee arthroplasty (TKA) patients in the EOS imager, compared to the standard instantaneous, cone-beam, uniplanar digital X-ray set-up. At a mean of 5 years post-surgery, 15 TKA participants (mean 67 years, 12 female, 3 male) were imaged twice in the biplanar imager. To reduce motion during the scan, a support for the foot was added and the scan speed was increased. The voltage was also increased compared to standard settings for better marker visibility over the implant. A small calibration object was included to remove any remaining sway in post-processing. The 95% confidence interval precision was 0.11, 0.04, and 0.15 mm in the x, y, and z planes, respectively and 0.15, 0.20, and 0.14° in Rx, Ry, and Rz. Two participants had motion artifacts successfully removed during post-processing using the small calibration object. With faster speeds and stabilization support, this study found an in vivo RSA precision of ≤ 0.15 mm and ≤ 0.20° for TKA exams, which is within published uniplanar values for arthroplasty RSA. The biplanar imager also adds the benefits of weight bearing imaging, 3D alignment measurements, a lower radiation dose, and does not require a reference object due to known system geometry and automatic image registration

Background. Digital templating is a critical part of preoperative planning for total hip arthroplasty (THA) that is increasingly used by orthopaedic surgeons as part of their preoperative planning process. Digital templating has been used as a method of reducing hospital costs by eliminating the need for acetate films and providing an accurate method of preoperative planning. Pre-operative templating can help anticipate and predict appropriate component sizes to help avoid postoperative leg length discrepancy, failure to restore offset, femoral fracture, and instability. A preoperative plan using digital radiographs for surgical templating for component size can improve intraoperative accuracy and precision. While templating on conventional and digital radiographs is reliable and accurate, the accuracy of templating on digital images acquired with a novel biplanar imaging system (EOS Imaging Inc, Cambridge, MA, USA) remains unknown. EOS imaging captures whole body images of a standing patient without stitching or vertical distortion, less magnification error and exposes patients to less radiation than a pelvis AP radiograph. Therefore, the purpose of this study was to compare EOS imaging and conventional anteroposterior (AP) xrays for preoperative digital templating for THA, and compare the results to the implant sizes used intraoperatively. Methods. Forty primary unilateral THA patients had preoperative supine AP xrays and standing EOS imaging. The mean age for patients was 61 ± 8 years, the mean body mass index 29 ± 6 kg/m. 2. and 21 patients were female. All patients underwent a THA with the same THA system (R3 Acetabular System and Synergy Cementless Stem, Smith & Nephew, TN, USA) by a single surgeon. Two blinded observers preoperatively templated using both AP xray and EOS imaging for each patient to predict acetabular size, femoral component size, and stem offset. All templating was performed by two observers with standard software (Ortho Toolbox, Sectra AB, Linköping, Sweden) [Figure 1] one week prior to surgery, and were compared using the Cronbach's alpha (∝) coefficient of reliability. The accuracy of templating was reported as the average percent agreement between the implanted size and the templated size for each component. Results. For templating acetabular component size, the exact size was predicted for 48% using AP xrays and 70% using EOS imaging, and within 1 size for 88% using xrays and 98% using EOS imaging. For templating femoral component size, the exact size was predicted exactly for 33% using AP xrays and 60% using EOS imaging, and within 1 size for 85% using xrays and 98% using EOS imaging (Figure 2). Interobserver agreement was excellent for acetabular components (Cronbach's α = 0.94) and femoral components (Cronbach's α = 0.96) using EOS imaging. Conclusions. This study demonstrates that preoperative digital templating for THA using EOS imaging is accurate, with excellent interobserver agreement. EOS imaging has less magnification error, which may partially explain the accuracy of our templating method

Glenoid baseplate orientation in reverse shoulder arthroplasty (RSA) influences clinical outcomes, complications, and failure rates. Novel technologies have been produced to decrease performance heterogeneity of low and high-volume surgeons. This study aimed to determine novice and experienced shoulder surgeon's ability to accurately characterise glenoid component orientation in an intra-operative scenario. Glenoid baseplates were implanted in eight fresh frozen cadavers by novice surgical trainees. Glenoid baseplate version, inclination, augment rotation, and superior-inferior centre of rotation (COR) offset were then measured using in-person visual assessments by novice and experienced shoulder surgeons immediately after implantation. Glenoid orientation parameters were then measured using 3D CT scans with digitally reconstructed radiographs (DRRs) by two independent observers. Bland-Altman plots were produced to determine the accuracy of glenoid orientation using standard intraoperative assessment compared to postoperative 3D CT scan results. Visual assessment of glenoid baseplate orientation showed “poor” to “fair” correlation to 3D CT DRR measurements for both novice and experienced surgeon groups for all measured parameters. There was a clinically relevant, large discrepancy between intra-operative visual assessments and 3D CT DRR measurements for all parameters. Errors in visual assessment of up to 19.2 degrees of inclination and 8mm supero-inferior COR offset occurred. Experienced surgeons had greater measurement error than novices for all measured parameters. Intra-operative measurement errors in glenoid placement may reach unacceptable clinical limits. Kinesthetic input during implantation likely improves orientation understanding and has implications for hands-on learning

Femoral head diameters in THA have been increasing due to good long-term outcomes of 1. st. generation HXLP cups. Furthermore, some 2. nd. generation HXLP cups allow 36mm or larger heads. However, larger femoral head diameters increase the frictional torque and may lead to early cup migration and loosening. And there is a concern that larger head diameters and reduced liner thickness may increase polyethylene wear. In this study, we compared early acetabular component migration and wear rates between a group of larger heads using a 2. nd. generation HXLP and a group smaller heads using a 1. st. generation HXLP. The larger head group comprising 30 hips underwent THA between February 2010 and March 2011 with the use of a sequentially cross-linked polyethylene liner (X3). 30 patients were included in this study (30 women). Their mean age was 59.3years; mean weight was 53.6kg. Trident HA-coated cementless cups were used and the sizes ranged from 46mm to 56mm (mean 50.5mm). The head diameters were 36mm in 23hips, 40mm in 5 hips, and 44mm in 2hips. All X3 liners were 5.9mm or less in thickness. A control group was selected from a previous case series that had undergo THA between July 2007 and January 2008 using a 1st generation HXLP liner (Crossfire) by matching age and sex. Therefore 30 patients were included in this study (30 women) too. Their mean age was 60.0 years; mean weight was 55.5kg. The same Trident cups were used and the sizes ranged from 46mm to 56mm (mean 49.5mm). The head diameters were 26mm in 19hips and 32mm in 11hips. The liner thicknesses were 7.8mm or more. All hips had standardized anteroposterior pelvic digital radiographs performed postoperatively and cup migration was measured on digital radiographs at the immediate postoperative period and two year using EBRA-CUP software. We analyzed horizontal and vertical cup migration distance and the difference in cup anteversion and inclination angle at two years. Additionally, total head penetrarion and polyethylene liner volumetric wear rates were measured using a computer-assited method with PolyWear software. The larger head group revealed an average of 0.48mm of horizontal migration, 0.75mm of vertical migration, 0.19degree of inclination change, and 1.26 degrees of anteversion change. The control group showed an average of 0.63mm of horizontal migration, 0.36mm of vertical migration, 0.07 degree of inclination change, and 0.88 degree of anteversion change. Based on the EBRA-CUP measurements, there were no cases of significant early loosening which was indicated by more than 1mm of migration, more than 2.5 degree of inclination change, or more than 3.3 degree of anteversion change. The liner penetration rates were 0.388±0.192mm/yr in the large head group and 0.362±0.178mm/yr in the control group. The difference was not significant (p=0.64.) The volumetric wear rates were 42.8±27.9mm⁁3/yr in the large head group and 42.0±33.0mm⁁3/yr in the control group. Again, the difference was not significant (p=0.94). No significant early cup migration or increased wear rate were detected in THA with the sequentially cross-linked polyethylene liner and 36mm or large heads at two years

Advances in cancer therapy have prolonged patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in longer survival, preserved mobility, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The ideal clinical decision support tool will be of the highest sensitivity and specificity, non-invasive, generalizable to all patients, and not a burden on hospital resources or the patient's time. Our research uses novel machine learning techniques to develop a model to fill this considerable gap in the treatment pathway of MBD of the femur. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data of consecutive MBD patients presenting from 2009–2016. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 546 patients comprising 114 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray and clinical data including patient demographics, Mirel's criteria, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. We have trained a convolutional neural network (CNN) with AP X-ray images of 546 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. The model converges on two fully connected deep neural network layers that output the risk of fracture. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections, until overall prediction accuracy is optimized. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across five test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a model's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Our model achieved 88.2% accuracy in predicting fracture risk across five-fold cross validation testing. The F1 statistic is 0.87. This is the first reported application of convolutional neural networks, a machine learning algorithm, to this important Orthopaedic problem. Our neural network model was able to achieve reasonable accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to externally validate this algorithm on an international cohort

Advances in cancer therapy have prolonged cancer patient survival even in the presence of disseminated disease and an increasing number of cancer patients are living with metastatic bone disease (MBD). The proximal femur is the most common long bone involved in MBD and pathologic fractures of the femur are associated with significant morbidity, mortality and loss of quality of life (QoL). Successful prophylactic surgery for an impending fracture of the proximal femur has been shown in multiple cohort studies to result in patients more likely to walk after surgery, longer survival, lower transfusion rates and shorter post-operative hospital stays. However, there is currently no optimal method to predict a pathologic fracture. The most well-known tool is Mirel's criteria, established in 1989 and is limited from guiding clinical practice due to poor specificity and sensitivity. The goal of our study is to train a convolutional neural network (CNN) to predict fracture risk when metastatic bone disease is present in the proximal femur. Our fracture risk prediction tool was developed by analysis of prospectively collected data for MBD patients (2009–2016) in order to determine which features are most commonly associated with fracture. Patients with primary bone tumors, pathologic fractures at initial presentation, and hematologic malignancies were excluded. A total of 1146 patients comprising 224 pathologic fractures were included. Every patient had at least one Anterior-Posterior X-ray. The clinical data includes patient demographics, tumor biology, all previous radiation and chemotherapy received, multiple pain and function scores, medications and time to fracture or time to death. Each of Mirel's criteria has been further subdivided and recorded for each lesion. We have trained a convolutional neural network (CNN) with X-ray images of 1146 patients with metastatic bone disease of the proximal femur. The digital X-ray data is converted into a matrix representing the color information at each pixel. Our CNN contains five convolutional layers, a fully connected layers of 512 units and a final output layer. As the information passes through successive levels of the network, higher level features are abstracted from the data. This model converges on two fully connected deep neural network layers that output the fracture risk. This prediction is compared to the true outcome, and any errors are back-propagated through the network to accordingly adjust the weights between connections. Methods to improve learning included using stochastic gradient descent with a learning rate of 0.01 and a momentum rate of 0.9. We used average classification accuracy and the average F1 score across test sets to measure model performance. We compute F1 = 2 x (precision x recall)/(precision + recall). F1 is a measure of a test's accuracy in binary classification, in our case, whether a lesion would result in pathologic fracture or not. Five-fold cross validation testing of our fully trained model revealed accurate classification for 88.2% of patients with metastatic bone disease of the proximal femur. The F1 statistic is 0.87. This represents a 24% error reduction from using Mirel's criteria alone to classify the risk of fracture in this cohort. This is the first reported application of convolutional neural networks, a machine learning algorithm, to an important Orthopaedic problem. Our neural network model was able to achieve impressive accuracy in classifying fracture risk of metastatic proximal femur lesions from analysis of X-rays and clinical information. Our future work will aim to validate this algorithm on an external cohort

Introduction. Upright body posture is maintained with the alignment of the spine, pelvis, and lower extremities, and the muscle strength of the body trunk and lower extremities. Conversely, the posture is known to undergo changes with age, and muscle weakness of lower extremities and the restriction of knee extension in osteoarthritis of the knee (knee OA) have been considered to be associated with loss of natural lumbar lordosis and abnormal posture. As total knee arthroplasty (TKA) is aimed to correct malalignment of lower extremities and limited range of motion of knee, particularly in extension, we hypothesized that TKA positively affects the preoperative abnormal posture. To clarify this, the variation in the alignment of the spine, pelvis, and lower extremities before and after TKA was evaluated in this study. Patients and methods. Patients suffering from primary knee OA who were scheduled to receive primary TKA were enrolled in this study. However, patients with arthritis secondary to another etiology, i.e. rheumatoid arthritis, trauma, or previous surgical interventions to the knee, were excluded. Moreover, patients who suffered from hip and ankle OA, cranial nerve diseases, or severe spinal deformity were also excluded. The sagittal vertical axis (SVA), the horizontal distance between the posterosuperior aspect of the S1 endplate surface and a vertical plumb line drawn from the center of the C7 vertebral body, is an important index of sagittal balance of the trunk. Thus, patients were classified into two groups based on the preoperative SVA with preoperative standing lateral digital radiographs: normal (< 40mm) and abnormal (≥ 40mm) groups. The variations in the sagittal alignment of the spine, pelvis and lower extremities were evaluated preoperatively, and at 1 and 3 months postoperatively. This study was approved by an institutional review board, and informed consent for participation was obtained from the patients. Results. Forty-nine knees in 49 patients were enrolled. Three different patterns of postural changes as well as hip and knee angles following TKA were observed. After TKA, the preoperatively normal SVA patients (26.5%) showed extension of the hip and knee joints and decrease of lumbar lordosis, while the SVA remained almost within the normal range. In the preoperatively abnormal SVA group, 13 patients (26.5%) showed extension of the knee joint while the SVA remained abnormal, however, 23 of the preoperatively abnormal SVA group patients (47.0%) showed improvement of SVA into the normal range with the extension of the hip and knee joints. Discussion. As the spine, pelvis, and lower extremities together affect body alignment, once limitation of knee extension due to severe knee OA is corrected and lower extremity alignment is improved with TKA, the lumbar lordosis may increase, and SVA could decrease. Recently, the relationship between the imbalance of the sagittal plane of the body and the risk of falls was described. From this, it could be said that TKA not only helped in recovering knee function and lower extremity alignment in severe knee OA, but also helped to improve posture and to protect from falls

Introduction. Aseptic loosening is the main reason for total knee arthroplasty (TKA) failure, responsible for more than 25% of the revision procedures, with most of the problems occurring with the tibial component. While early loosening can be attributed to failure of primary fixation, late implant loosening is associated with loss of fixation secondary to bone resorption due to altered physiological load transfer to the tibial bone. Several attempts have been made to investigate these changes in bone load transfer in biomechanical simulations and bone remodeling analyses, which can be useful to provide information on the effect of patient, surgery, or design-related factors. On the other hand, these factors have also been investigated in clinical studies of radiographic changes of bone density following TKA. In this study we made an overview of the knowledge obtained from these clinical studies, which can be used to inform clinical decision making and implant design choices. Methods. A literature search was performed to identify clinical follow-up studies that monitored peri-prosthetic bone changes following TKA. Within these studies, effects of the following parameters on bone density changes were investigated: post-operative time, region of interest, alignment, body weight, systemic osteoporosis, implant design and cementation. Moreover, we investigated the effect of bone density loss on implant survival. Results. A total of 19 studies was included in this overview, with a number of included patients ranging from 12 to 7,760. Most studies used DEXA (n=16), while a few studies performed analyses on calibrated digital radiographs (n=2), or computed tomography (n=1). Postoperative follow-up varied from 9 months to 10 years. Studies consistently report the largest bone density reduction within the first postoperative year. Bone loss is mainly seen in the medial region. This has been attributed to the change in alignment following surgery, during which often the pre-operative varus knee is corrected to a more physiological alignment, resulting in a load shift towards the lateral compartment. Measurements in unoperated contralateral legs were performed in 3 cases, and two studies performed standardized DEXA measurements to provide information on systemic osteoporosis. While on the short term no changes were observed, significant negative correlations have been found between severity of osteoporosis and peri-prosthetic bone density. No clear effects of bodyweight and cementation on bone loss have been identified. Although some studies do find differences between implant types, the variation in the data makes it difficult to draw general conclusions from these findings. Several studies reported no effect of bone loss on implant migration. In another study, a medial collapse was associated with a medial increase in density, suggesting that altered loading and increased stresses are responsible for both bone formation and the overload leading to collapse. Discussion. There are important lessons to be learned from these clinical studies, although generally the large spread in the DEXA data restricts strong conclusions. There is a large variation in used ROI definitions, complicating direct comparisons. Finally, most studies report density changes of well-functioning reconstructions, since only very large studies are able to gather enough failed cases

Introduction. When total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA) was indicated for the patient, it is important to perform the exact preoperative planning. Conventionally we created the plan based on the Xp films and transparent acetate sheets. Recntly, the digital radiographs and templating systems were introduced in hospitals and utilized for the preoperative planning. The purpose of this study is to investigate the accuracy of the digital templating by comparing the size of the implants between those chosen by the planning and those actually selected during the operation. Materials and methods. We investigated the plans of 715 knees with TKAs and 238 knees with UKAs between 2010 and 2014. There were 89 men and 438 women with average age of 72.1. There were 867 osteoarthritis, 46 rheumatoid arthritis, 39 osteonecrosis and 1 revision TKA. We created the preoperative planning using Electronic Picture and Communication system (PACS) and templating system (Advanced Case Plan 2.2 / Stryker). [Fig. 1] During the operation we have checked the actual femoral and tibial sizes of the implants, and compared them with preoperative plannings. Results. The exact matching of the sizes of the implants between the planning and the operation with TKAs were 59.4% for the femoral components, 52.7% for the tibial components and 32.4% for both components. [Fig. 2] While those figures with UKAs were 88.7%, 67.6% and 63.0% respectively. [Fig. 3] The matching within 1 size difference of the size of the implants between the planning and the operation were 92.4% with TKAs and 95.8% with UKAs. Discussion. Our study suggested that the digital templating of the TKAs and UKAs had satisfactory accuracy to use as preoperative planning for the operation. The accuracy was better in femur than that of tibia. The difference of the accuracy indicate the probable presence of the hyperplasia of the medial tibial condyle that we cut off to get good ligamtnt balancing. The accuracy of the UKAs was better than that of TKAs. During UKAs, we initially chose the predicted size of the devise and cut the bone, and then finally select the size of the implant. While during TKAs, we measure the size of the bone and then cut the bone. This difference of the operative procedure may result in the higher accuracy of UKAs. We conclude that digital templating for preoperative planning of TKAs and UKAs had satisfactory accuracy

Introduction. Success of total hip replacement (THR) is closely linked to positioning of the acetabular component. Malalignment increases complication rates. Our aim was to describe the anteversion and inclination of the inherent acetabulum in arthritic hips and identify the number that fall out with the ‘safe zone’ of acetabular position described by Lewinnek et al. (anteversion 15±10 degrees; inclination 40±10 degrees). Materials/Methods. A series of 65 hips undergoing non-image based computer navigated THR for Osteoarthritis were investigated. Anteversion and inclination was measured with the help of cup trials fixed with computer trackers aligned in orientation of the natural acetabulum. The acetabular inclination in all hips was measured on pre-operative digital radiographs. Results. There were 29 males and 36 females with average age of 68 years. Anteversion of males was significantly lower than females with a mean difference of −5.5 degrees (95% CI-10.5–0.5 degrees) with p value of 0.033. There was no significant difference with respect to inclination. Overall 69 % of patients had a combined inclination and anteversion that fell outside the ‘safe zone’. Conclusion. Mean acetabular inclination falls outwith the ‘safe zone’ but mean anteversion falls within. The inherent acetabular anatomy of arthritic hips varies widely. Females have significantly more anteversion. Care should be taken when using inherent anatomy of acetabulum as a guide when doing a THR

Introduction. The application of digital radiography in clinical settings has provided the opportunity to obtain high quality images while reducing the overall cost of imaging, thus this technology is gaining more popularity in clinical settings specifically in orthopaedic clinics . 1. In addition, advanced computer software helps with quick and easy approach to perform preoperative measurements with high accuracy . 2. Preoperative templating has become one of the standard of care procedures that prepares the surgical team to lower surgical time and more efficiently face intraoperative complications . 3. Commonly, the acetabular cup size and femoral stem size are templated and used for estimation process . 4. However, the goal of this study was to investigate whether patients' demographics would play a role in increasing the accuracy of templating. We hypothesized that preoperative implant templating (acetabular and femoral components), gender, weight, height, and body mass index (BMI) would contribute to higher accuracy of templating in total hip arthroplasty (THA). Method. Digital radiographs of 468 patients treated with THA from August 2012 to December 2013 at a single institution were reviewed. They aged 59.96 ±12.50 years and 436 of them were diagnosed with osteoarthritis, 53 with avascular necrosis, 13 with failed THA, 2 with infection, 4 post trauma, and 13 with failed hemi arthroplasty. THA templating was conducted by assessing the anteroposterior view of the pelvis that was centered over the pubic symphysis, with the hips in 10° to 15° of internal rotation and we utilized a lateral frog-leg view of the affected hip. A backward stepwise multiple regression model was used to exclude the parameters that had no significant contribution to the accuracy of the measurement. Results. The outcome of the backward stepwise analysis indicated that in estimation of actual acetabular size, gender and body weight did not have a significant role however preoperative femoral and acetabular component size, BMI, and height were significant factors to predict the model. This model had an adjusted R2=0.795. The femoral component size was significantly predicted from preoperative femoral size and other parameters did not add significant accuracy to the model. The model reached an adjusted R2 = 0.723. Discussion. We explored the possibility of using other factors to improve the accuracy of preoperative templating. We were successful to predict the acetabular size with accuracy of 98.5% within two sizes and 100% femoral size in the same range. The additional accuracy may be translated in lower treatment costs by reducing expensive inventory fees

Introduction:. Patient-specific cutting guides (PSCG) built from imaging of the extremity can improve the accuracy of bone cuts during total knee replacement (TKR). Some reports have suggested that PSCG offer only marginal improvement in the accuracy of alignment and component positioning in TKA. We compared outcomes between TKRs done with PSCG versus standard, intramedullary-based instrumentation. Methods:. Blood loss, duration of surgery, alignment of the mechanical axis of the leg, and implant position on standing, long-leg, and standard lateral digital radiographs were compared between a CT-guided, custom-built TKA implant (n = 50; ConforMIS iTotal, Boston, MA) implanted with PSCG, versus an off-shelf posterior stabilized TKA implanted with standard instrumentation (n = 50; NKII total knee, Zimmer, Warsaw, IN). The fraction of outliers (>3 degrees) was calculated for the two groups. Results:. The mean mechanical axis of iTotal was 181 degrees with a fraction of outliers of 0.2, versus 178 degrees for NKII with fraction of outliers of 0.7. For frontal plane positioning of femoral components, fraction of outliers for iTotal was 0.04, versus 0.6 for NKII. For tibial components, corresponding values were 0.1 and 0.6, respectively. Sagittal plane outliers were 0.2 and 0.9, respectively, for femoral components; and 0.2 and 0.6 for tibial components. Surgery duration was 5 minutes less and blood loss was 100 mL less for iTotal than for intramedullary-aligned NKII. Conclusion:. Patient specific instrumentation and custom-built implants showed a trend toward improved accuracy of alignment, reduction in blood loss and operating time, when compared to standard, off-the-shelf TKA implants with intramedullary alignment, with fewer radiographic outliers. Larger, randomized trials are necessary to evaluate this technology further, but the initial outcomes appear favorable, with no cost disadvantage to the custom-built implant

Purpose. Recently many authors have questioned the role of tourniquets in primary knee arthroplasty (TKA). Meanwhile, whether the use of an intra-articular wound drainage is an advance over the lack of a drain in TKA is controversial in the literature. This study aimed to investigate the efficacy and safety of drainage or not in TKA without a tourniquet. Methods. Eighty participants who underwent primary unilateral TKA were prospectively enrolled and were randomized to one of two techniques during surgery without a tourniquet: drainage (Group A) or non-drainage (Group B). Blood loss was monitored perioperatively. The operating time, allogeneic blood transfusion rate, thigh pain, knee pain, limb swelling, clinical outcome as measured by the hospital for special surgery (HSS) score, the ability to straight-leg raise, visual analog scale (VAS) in pain, length of stay and knee active range of motion (ROM) were also recorded. The digital radiographs taken at 6 months postoperatively were assessed for cement mantle thickness and radiolucency using the Knee Society radiographic zones. Results. The mean Haemoglobin levels on day one and three postoperative were significantly higher in Group B (112.1±10.6 mg/dL, 99.5±9.6 mg/dL) than in Group A (106.1±12.4 mg/dL, 92.7±13.1 mg/dL) (P=0.026, P=0.011). Blood or blood product transfusion was necessary for thirteen patients in Group A (33.3%) whereas five patients of Group B (13.1%) were in need of blood products, the difference was significant (P=0.036). The total blood loss in Group A was significant more than Group B (597.7 ± 331.6ml vs. 496.1 ± 260.8ml, P=0.012). Among the patients in Group B, haemarthrosis developed in 3 knees (7.9%, P=0.23). Calf circumference measurements of both groups showed a significant difference at postoperative day one (3.2% vs. 5.6%, P = 0.012) as well as day two (4.9% vs. 7.1%, P = 0.07). A superficial wound infection was detected within 3 months after surgery in 3 knees (7.6%) in Group A, whereas no superficial wound infection was observed in Group B, the difference between groups did not reached statistical significance (P=0.248). The difference in VAS score of knee active pain between groups on postoperative day three, five and three weeks were statistically significant (P=0.012, P=0.003, P=0.008). There were no differences in terms of surgical time, thigh/knee rest pain scores, discharge/post-op three weeks HSS score, range of motion, ambulation time, straight-leg raising rate, knee/ thigh circumference, length of stay, cement mantle thickness, or the presence of radiolucency. Conclusions. Drainage does not exhibit substantial advantages in promoting post-operative rehabilitation after uncomplicated TKA, compared with non-drainage. On the other hand, it might increase blood loss and wound complication. Therefore, we believe that it is safe and beneficial for our patients to routinely perform uncomplicated TKA without a postoperative drain if the procedure is done without a tourniquet. On condition that prolonged operation time, multiple extra bone cutting, operative outside joint capsule, we still recommend placing a drainage tube