Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for this purpose to guide clinicians in order to treat PFI. There are also concerns about validity of the Dejour classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol classification (OBC) is a recently proposed system of classification of TD and the authors report a fair-to-good interobserver agreement and good-to-excellent intra-observer agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications. 6 assessors (4 consultants and 2 registrars) independently evaluated 100 magnetic resonance axial images of the patella-femoral joint for TD and classified them according to OBC and DJC. These assessments were again repeated by all raters after 4 weeks. The inter and intra-observer reliability scores were calculated using Cohen's kappa and Cronbach's alpha. Both classifications showed good to excellent interobserver reliability with high alpha scores. The OBC classification showed a substantial intra-observer agreement (mean kappa 0.628)[p<0.005] whereas the DJC showed a moderate agreement (mean kappa 0.572) [p<0.005]. There was no significant difference in the kappa values when comparing the assessments by consultants to those by registrars, in either classification systems. This large study from a non-founding institute shows both classification systems to be reliable for classifying TD based on magnetic resonance axial images of the patella-femoral joint, with the simple to use OBC having a higher intra-observer reliability score compared to the DJC.
Abstract. Purpose. Intracanal rib head penetration is a well-known entity in dystrophic scoliotic curves in neurofibromatosis type 1. There is potential for spinal cord injury if this is not recognised and managed appropriately. No current CT-based classification system is currently in use to quantify rib head penetration. This study aims to propose and evaluate a novel CT-based classification for rib head penetration primarily for neurofibromatosis but which can also be utilised in other conditions of rib head penetration. Materials and methods. The grading was developed as four grades: normal rib head (RH) position—Grade 0, subluxed ext-racanal RH position—Grade 1, RH at pedicle—Grade 2, intracanal RH—Grade 3. Grade 3 was further classified depending on the head position in the canal divided into thirds. Rib head penetration into proximal third (from ipsilateral side)—Grade 3A, into the middle third—Grade 3B and into the distal third—Grade 3C. Seventy-five axial CT images of Neurofibromatosis Type 1 patients in the paediatric age group were reviewed by a radiologist and a spinal surgeon independently to assess interobserver and
Abstract. Purpose. No clinical CT based classification system is currently in use for Lumbar Foraminal Stenosis. MRI scanners are not easily available, are expensive and may be contraindicated in an increasing number of patients. This study aims to propose and evaluate the reproducibility of a novel CT based classification for lumbar foraminal stenosis. Materials and Methods. The grading was developed as 4 grades. Normal foramen – Grade 0, Anteroposterior(AP)/Superoinferior (SI)(single plane) fat compression – Grade 1, Both AP/SI compression (two planes) – Grade 2 (both AP and SI) without distortion of nerve root, Grade 2 with distortion of nerve root – Grade 3. 800 lumbar foramen of a cohort of 100 random patients over the age of 60 who had undergone both CT and MRI scans were reviewed by two radiologists independently to assess agreement of the novel CT classification against the MRI based grading system of Lee et al. Interobserver(n=400) and
The Gartland extension-type supracondylar humerus fracture is the most common elbow fracture in the paediatric population. Depending on fracture classification, treatment options range from nonoperative treatment such as taping, splinting or casting to operative treatments such as closed reduction and percutaneous pinning or open reduction. Classification variability between surgeons is a potential contributing factor to existing controversy over nonoperative versus operative treatment for Type II supracondylar fractures. The purpose of this study was to investigate levels of agreement in classification of extension-type supracondylar humerus fractures using the Gartland classification system. A retrospective chart review was conducted on patients aged 2–12 years who had sustained an extension-type supracondylar fracture and received either operative or nonoperative treatment at a tertiary children's hospital. De-identified baseline anteroposterior (AP) and lateral plain elbow radiographs were provided along with a brief summary of the modified Gartland classification system to surgeons across Canada, United States, Australia, United Kingdom and India. Each surgeon was blinded to patient treatment and asked to classify the fractures as Type I, IIA, IIB or III according to the classification system provided. A total of 21 paediatric orthopaedic surgeons completed one round of classification, of these, 15 completed a second round using the same radiographs in a reshuffled order. Kappa values using pre-determined weighted kappa coefficients were calculated to assess interobserver and
We present an analysis of manual and computer-assisted preoperative pedicle screw placement planning. Preoperative planning of 256 pedicle screws was performed manually twice by two experienced spine surgeons (M1 and M2) and automatically once by a computer-assisted method (C) on three-dimensional computed tomography images of 17 patients with thoracic spinal deformities. Statistical analysis was performed to obtain the
Introduction. Patient-specific cutting guides entered into clinical practice few years ago, first introduced in total knee replacement and recently also for other joint replacements. Advantages claimed are improving accuracy and repeatability in implant placement. New patient-specific guides to perform an accurate femoral neck resection and provide a precise alignment reference for acetabular reaming in total hip arthroplasty (THA) were recently developed by Medacta International: MyHip Technology. To date femoral guides can be designed for both anterior and posterior approaches, whereas acetabular guides are available only for posterior approach. Evaluation of the repeatability and reproducibility of MyHip guides placement on cadavers is performed using a navigation system. Accuracy of femoral MyHip guides is evaluated also through one author's clinical experience (RP). Materials and Methods. During each cadaveric session one body (2 hips) was available. A pre-operative CT scan has been obtained and used in order to create the 3D bone model of the pelvis and proximal femurs. Afterwards, a surgical planning for THA has been performed for each case, and, once it was approved by the surgeons, the designed patient-specific blocks were made.
Restoration of ankle alignment is thought to be critical in total ankle arthroplasty (TAA) outcomes, but previous research is primarily focused on coronal alignment. The purpose of this study was to investigate the sagittal alignment of the talar component. The talar component inclination, measured by the previously-described gamma angle, was hypothesized to be predictive of TAA outcomes. A retrospective review of the Canadian Orthopaedic Foot and Ankle Society (COFAS) database of ankle arthritis was performed on all TAA cases at a single center over a 11-year period utilizing one of two modern implant designs. Cases without postoperative x-rays taken between 6 and 12 weeks were excluded. The gamma angle was measured by two independent orthopaedic surgeons twice each and standard descriptive statistics was done in addition to a survival analysis. The postoperative gamma angles were analyzed against several definitions of TAA failure and patient-reported outcome measures from the COFAS database by an expert biostatistician. 109 TAA cases satisfied inclusion and exclusion criteria. An elevated postoperative gamma angle higher than 22 degrees was associated with talar component subsidence, defined as a change in gamma angle of 5 degrees or more between postoperative and last available followup radiographs. This finding was true when adjusting for age, gender, body mass index (BMI), and inflammatory arthritis status. All measured angles were found to have good inter- and
In the vast majority of patients, the anatomical and mechanical axes of the tibia in the coronal plane are widely accepted to be equivalent. This philosophy guides the design and placement of orthopaedic implants within the tibia and in both the knee and ankle joints. However, the presence of coronal tibial bowing may result in a difference between these two axes and hence cause suboptimal placement of implanted prostheses. Although the prevalence of tibial bowing in adults has been reported in Asian populations, to date no exploration of this phenomenon in a Western population has been conducted. The aim of this study was to quantify the prevalence of coronal tibial bowing in a Western population. This was an observational retrospective cohort study using anteroposterior long leg radiographs collected prior to total knee arthroplasty in our high volume arthroplasty unit. Radiographs were reviewed using a Picture Archiving and Communication System. Using a technique previously described in the literature for assessment of tibial bowing, two lines were drawn, each one third of the length of the tibia. The first line was drawn between the tibial spines and the centre of the proximal third of the tibial medullary canal. The second was drawn from the midpoint of the talar dome to the centre of the distal third of the tibial medullary canal. The angle subtended by these two lines was used to determine the presence of bowing. Bowing was deemed significant if more than two degrees. The position of the apex of the bow determined whether it was medial or lateral. Measurements were conducted by a single observer and 10% of measurements were repeated by the same observer and also by two separate observers to allow calculation of intraclass correlation coefficients (ICCs). A total of 975 radiographs consecutively performed in the calendar years 2015–16 were reviewed, 485 of the left leg and 490 of the right. In total 399 (40.9%) tibiae were deemed to have bowing more than two degrees. 232 (23.8%) tibiae were bowed medially and 167 (17.1%) were bowed laterally. The mean bowing angle was 3.51° (s.d. 1.24°) medially and 3.52° (s.d. 1.33°) laterally. Twenty-three patients in each group (9.9% medial/13.7% lateral) were bowed more than five degrees. The distribution of bowing angles followed a normal distribution, with the maximal angle observed 10.45° medially and 9.74° laterally. An
Background. Accurate and reproducible radiological assessment of shoulder replacement prostheses over time is important for identifying failure or to provide reassurance. A number of clearly defined radiological parameters have been described to help standardise the radiological assessment of prostheses. To our knowledge, this is the first study conducted to test the reproducibility and reliability of these measurements. Aim. The aim of this work was to test
Manual postoperative CT calculation of anteversion and inclination of the acetabular cup can be inaccurate and depends on the observer's experience. The aim of this study is to describe and present a validation of a new CT-image-based dedicate software (EGIT) for calculation of the acetabular component placement. The software principle is based on a three-dimensional reconstruction of a patient's bones from anatomical data collected postoperatively on the patient's CT scan. 15 Patient to be operated for THR were enrolled in this study. All patients were evaluated with post operative CT-scan. Measurement of Cup positioning were performed with two different methods: a manual method, performed by an expert radiologist, and a software CT image based method. Statistical analysis was performed with Intraclass Correlation Coefficent to asses interobserver and
Background. This is an epidemiological study of patients with middle third clavicle fractures presenting to a tertiary hospital. The data is used to formulate a classification system for middle third clavicle fractures based on fracture configuration and displacement. Description of methods. Patients presenting primarily to a referral hospital with middle third clavicle fractures were identified using the PACS radiology system. The radiographs were reviewed to determine the fracture type, displacement, shortening and amount of comminution. The clinical notes of each patient were reviewed to determine the mechanism of injury, soft tissue status, neurovascular status and treatment rendered. A novel classification system was developed to describe the different fracture configurations seen in the group. The interobserver and
The transtibial approach is widely used for femoral tunnel positioning in ACL reconstruction. Controversy exists over the superiority of this approach over others. Few studies reflected on the reproducibility rates of the femoral tunnel position in relation to the approach used. We reviewed AP and Lat X-ray radiographs post isolated ACL reconstruction for 180 patients for femoral tunnel position, tibial tunnel position and graft inclination angle. All patients had their operations performed by one surgeon in one hospital between March 2006 and Sep 2010. All operations were performed using one standard technique using transtibial approach for femoral tunnel positioning. Two orthopaedic fellows, with similar experiences, reviewed blinded radiographs. A second reading was done 8 weeks later. Pearson inter-observer, intra-observer correlation and Bland-Altman agreements plots statistical analyses were done. Mean age was 29 years (range 16–54), Pearson intra-observer correlation shows substantial to perfect agreement while Pearson's inter-observer correlation shows moderate to substantial agreement. Previous literature proved that optimal femoral tunnel position for the best clinical and biomechanical outcome is for the centre of the tunnel to be at 43% from the lateral end of the width of the femoral condyles on the AP view and at 86% from the anterior end of the Blumensaat's line on the lateral view. In our study 85% of the femoral tunnels were within +/− 5% of the optimal tunnel position on the AP views, and more than 70% of the femoral tunnels were within +/−5% of the optimal tunnel position on the Lateral view. Interobserver and
Introduction. Periprosthetic osteolysis following total hip arthroplasty is caused mainly by polyethylene wear particles and necessitates revision surgery at some stage even in the presence of well-fixed implants. Therefore, methods to estimate the polyethylene wear become important, with manual wear measurement methods as the main outcome measurement even in the presence of computer-assisted measurement methods on account of easy availability and simplicity in their use with reasonable accuracy. The purposes of this study were to quantify the accuracy and reproducibility of the slide presentation software method on clinical radiographs and to compare it with that of the previously described Livermore's method, and to determine the usefulness of the slide presentation software methods for highly cross linked polyethylene wear measurement. Materials and Methods. 81 hips out of 61 patients who underwent primary total hip arthroplasty between October 2000 and January 2006 were retrospectively evaluated for polyethylene wear by two independent observers using the Livermore's and the slide presentation software methods. All the hips were implanted with highly cross linked polyethylene acetabular liners with cementless acetabular components. The 28 mm sized cobalt chrome alloy femoral heads were used in all cases. The mean age of the patients was 50.8 years(range, 27–73 years), and the mean follow-up period was 6.6 years (range, 2–11 years). Paired radiographs were analyzed using the Livermore's and the slide presentation software method. For the Livermore's methods, radiographs were magnified to 200%, printed, and readings taken with digital calipers with an accuracy of 0.01 mm(Figure 1). For the slide presentation software method, we used Microsoft Office PowerPoint software(Microsoft Corp., Redmond, WA, USA) as described in a previous our study(Figure 2). Results. The mean polyethylene wear rate in 81 hips measured by the Livermore's method was found to be 0.071±0.12 and 0.081±0.09 mm/year by observer 1 and 2 respectively. The mean polyethyelene wear rate measured by slide presentation software method was found to be equally 0.069±0.07 mm/year by observer 1 and 2. Interobserver and
Background. Humeral retroversion is variable among individuals, and there are several measurement methods. This study was conducted to compare the concordance and reliability between the standard method and 5 other measurement methods on Twodimensional (2D) computed tomography (CT) scans. Methods. CT scans from 21 patients who underwent shoulder arthroplasty (19 women and 2 men; mean age, 70.1 years [range, 42 to 81 years]) were analyzed. The elbow transepicondylar axis was used as a distal reference. Proximal reference points included the central humeral head axis (standard method), the axis of the humeral center to 9 mm posterior to the posterior margin of the bicipital groove (method 1), the central axis of the bicipital groove –30° (method 2), the base axis of the triangular shaped metaphysis +2.5° (method 3), the distal humeral head central axis +2.4° (method 4), and contralateral humeral head retroversion (method 5). Measurements were conducted independently by two orthopedic surgeons. Results. The mean humeral retroversion was 31.42° ± 12.10° using the standard method, and 29.70° ± 11.66° (method 1), 30.64°± 11.24° (method 2), 30.41° ± 11.17° (method 3), 32.14° ± 11.70° (method 4), and 34.15° ± 11.47° (method 5) for the other methods. Interobserver reliability and
Inter- and intra-observer variation has been noted in the analysis of radiographic examinations with regard to experience of surgeons, and the monitors used for conducting the evaluations. The aim of this study is to evaluate inter/intra observer variation in the measurement of mechanical alignment from long-leg radiographs. 40 patients from the elective waiting list for TKA underwent long leg radiographs pre-operatively and 6 months post-operatively (total of 80 radiographs). The x-rays were analysed by 5 observers ranging in experience from medical student to head orthopaedic surgeon. Two observers re-analysed their results 6 months later to determine
Purpose. It is generally accepted that the cement mantle surrounding the femoral component of a cemented total hip arthroplasty (THA) should be complete without any defects, and of at least 2 mm in thickness. Radiographic evaluation is the basis for assessment of the cement mantle. The adequacy of radiographic interpretation is subject to debate. Poor interobserver and
Background. The use of Computed Tomography (CT) as a medical imaging tool has widespread applications in the field of knee surgery. Surgeons use a CT scan in a conventional way during the pre-operative stage, to plan the position of the femoral component in the horizontal plane. In the post-operative stage, the use of a CT scan is a routine tool in the evaluation of failed TKA as rotational malalignment of the femoral component has been determined as a cause of poor clinical outcome after TKA. Aim. How accurately can we measure the different angles with importance for alignment on a 3D-image in comparison to a standard CT, 2D, image. Material and methods. This study includes patients above 55 years of age who were scheduled for a TKA at our centre and who had a pre- and postoperative full-leg length computed tomography (CT). These images were analysed using Mimics V 16.0 ® and 3-matic V 8.0 ® (Materialise, Haasrode, Belgium) to create the surface reconstruction and perform the 3D-measurements. Different angles were measured pre- and post-operatively on these images both in 2D as in 3D: condylar twist angle (CTA), posterior condylar angle (PCA), hip-knee-ankle angle (HKA), tibiofemoral rotation angle (TFRA), posterior tilt of the tibial implant (STPA) and the frontal plane angle of the tibial implant (FTPA). A power analysis showed a needed sample size of 18 patients. Pre-operatively 21 patients were included, 18 of them also received a post-operative full-leg CT. Three observers participated in the study and they all performed all analyses twice with a minimum interval of one week for obtaining intra-observer repeatability. Statistical analysis was performed to obtain the intra- and interobserver variability. Results. The intra-and interobserver intra-class coefficients (ICC) were evaluated using the classification of Landis&Koch (see table). Preoperative results: Rotation of femoral component in 3D: ICC CTA=0,73; ICC PCA=0,66. Rotation in 2D: ICC PCA=0,75, ICC CTA=0,84. The highest ICC was found for the HKA: ICC>0,98 both 2D and 3D. Postoperative results. All ICC's are in the highest category (‘almost perfect’) except for the
Introduction. Total hip arthroplasty is considered to be one of the most successful orthopaedic interventions. Acetabular component positioning has been shown to affect dislocation rates, component impingement, bearing surface wear rates, and need for revision surgery. The safe zones of acetabular component positioning have previously been described by Lewinnek et al. as 5 to 25 degrees of cup version and 30 to 50 degrees of inclination. Callanan et al. later modified the inclination to 30 to 45 degrees. Our aim was to assess whether THA via robotic assisted posterior approach (PA) improves acetabular component positioning compared to fluoroscopic guided anterior approach THA (AA). Methods. Subjects. This study is a matched-pair case-control study using prospectively collected data from THAs done between January 2012 and December 2013. Patients who underwent primary THA using the PA or AA by the senior surgeons (MH and JAR) were included in the study. Ninety-six patients (of 176; 55%) underwent AA and 80 (of 176; 45%) underwent PA THAs. The matching process was performed by an observer blinded to the radiographic outcomes (EK). Patients were matched for sex and BMI +− 8 units. Seventy-nine patients who had AAs were manually matched to 79 patients who had PAs. Surgical Techniques. For the AA THAs, the patient is supine and the approach is performed through a modified smith Peterson approach. Acetabular cup positioning is assessed intraoperatively with fluoroscopy. For the PA THAs, the patient in the lateral position using the posterior approach. Acetabular cup positioning was guided by the MAKO robotic hip system using preoperative CT scans of the involved hip. Radiographic Measurements. The radiographic measurements were done manually using a standardized technique by two observers blinded to the type of arthroplasty performed. Spearman's rank correlation coefficient was used to test user dependent variability. Means were used for final calculations. Statistical Analysis. The average cup inclination and anteversion angles were calculated. Calculation of the number of hips that were in the safe zones of Lewinnek (inclination, 30°–50°; anteversion, 5°–25°) and Callanan (inclination, 30°–45°; anteversion, 5°–25°) regarding inclination, anteversion, and a combination of both were done for both groups. Independent t-tests were performed to compare both groups for sex, BMI, and inclination and anteversion angles. Fisher's exact test was used to compare both groups regarding the number of hips in the safe zones of Lewinnek and Callanan. Relative risk and absolute risk reduction were calculated. Results. There was no significant difference in BMI between the two groups.
Background:. The balance between the subscapularis muscle and the infraspinatus/teres minor muscles, often referred to as the rotator cuff ‘force couple’, has been proposed to be critical component for glenohumeral stability. Function of these muscles can be estimated with the evaluation of muscle atrophy. In clinical practice, muscle cross-sectional area (CSA) rather than 3D muscle volume measurement have been used because it is less time consuming. Because combined anthropometric measures of length and width more accurately define the muscular volume it seems logical to study the transversal rotator cuff force couple in the transversal plane an not in the sagittal plane of the body because both parameters can be included. But is it not clear which transversal CSA has the best correlation with muscle volume. Purpose:. To determine the optimal transversal CSA that has the best correlation with muscle volume. Material and Methods:. A total of 30 CT images containing the full scapula were used. Using Mimics® and 3-Matic® the correlation between CSA's and volume has been evaluated. Two methods have been evaluated. The first method was the CSA measured on transversal plane without 3D editing. The second method is a CSA measured on a new defined transversal plane using 3D reconstruction and reslice editing techniques. Results. Both techniques showed a very high inter and
A functional total knee replacement has to be well aligned, which implies that it should lie along the mechanical axis and in the correct axial and rotational planes. Incorrect alignment will lead to abnormal wear, early mechanical loosening, and patellofemoral problems. There has been increased interest of late in total knee arthroplasty with robot assistance. This study was conducted to determine if robot-assisted total knee arthroplasty is superior to the conventional surgical method with regard to the precision of implant positioning. Twenty knee replacements of ten robot-assisted and another ten conventional operations were performed on ten cadavers. Two experienced surgeons performed the surgery. Both procedures were undertaken by one surgeon on each cadaver. The choice of which was to be done first was randomized. After the implantation of the prosthesis, the mechanical-axis deviation, femoral coronal angle, tibial coronal angle, femoral sagittal angle, tibial sagittal angle, and femoral rotational alignment were measured via three-dimensional CT scanning. These variants were then compared with the preoperative planned values. In the robot-assisted surgery, the mechanical-axis deviation ranged from −1.94 to 2.13° (mean: −0.21°), the femoral coronal angle ranged from 88.08 to 90.99° (mean: 89.81°), the tibial coronal angle ranged from 89.01 to 92.36° (mean: 90.42°), the tibial sagittal angle ranged from 81.72 to 86.24° (mean: 83.20°), and the femoral rotational alignment ranged from 0.02 to 1.15° (mean: 0.52°) in relation to the transepicondylar axis. In the conventional surgery, the mechanical-axis deviation ranged from −3.19 to 3.84°(mean: −0.48°), the femoral coronal angle ranged from 88.36 to 92.29° (mean: 90.50°), the tibial coronal angle ranged from 88.15 to 91.51° (mean: 89.83°), the tibial sagittal angle ranged from 80.06 to 87.34° (mean: 84.50°), and the femoral rotational alignment ranged from 0.32 to 4.13° (mean: 2.76°) in relation to the transepicondylar axis. In the conventional surgery, there were two cases of outlier outside the range of 3° varus or valgus of the mechanical-axis deviation. The robot-assisted surgery showed significantly superior femoral-rotational-alignment results compared with the conventional surgery (p=0.006). There was no statistically significant difference between robot-assisted and conventional total knee arthroplasty in the other variants. All the variants were measured with high
