A huge commitment is required from patients and families who undergo a limb reconstruction procedure using the hexapod frame. This includes turning the struts on the frame, pin site care and intensive rehabilitation. Montpetit et al (2009) discovered that function, participation, engagement in regular activities of daily living is severely impacted during the hexapod lengthening period. Due to the long duration and burden for families, it is imperative that healthcare professionals understand the impact that the hexapod frame has on functional abilities and health related quality of life (HRQL). This project involved a retrospective review of prospectively collected data on function and HRQL during two periods of time: (1) when the hexapod frame is applied on the child's lower extremity and (2) when the lengthening phase is completed, and the hexapod frame is removed. Data from 38 children (mean age: 12 years SD 3.8) who completed lower extremity reconstruction using the hexapod frame and completed either or both the Pediatric Quality of Life Inventory 4.0 Generic Core Scale (PedsQL) and Pediatric Outcomes data Collection Instrument (PODCI) was included. Analysis included, standardized response means, the non-parametric
INTRODUCTION. Measurement of range of motion is a critical item of any knee scoring system. Conventional measurements used in the clinical settings are not as precise as required. Smartphone technology using either inclinometer application or photographic technology may be more precise with virtually no additional cost when compared to more sophisticated techniques such as gait analysis or image analysis. No comparative analysis between these two techniques has been previously performed. The goal of the study was to compare these two technologies to the navigated measurement considered as the gold standard. MATERIAL. Ten patients were consecutively included. Inclusion criterion was implantation of a TKA with a navigation system. METHODS. Two free angle measurement applications were downloaded to the Smartphone: one using inclinometer technology, the other using camera technology. After navigation assisted TKA and just before wound closure, the operated knee was positioned at full extension, 30±2°, 60±2°, 90±2° and 120±2° according to the navigated measurement. At each step, the knee flexion angle was measured with both Smartphone applications: inclinometer application (figure 1) and camera application (figure 2). For each of the ten patients, 5 navigated, 5 inclinometer and 5 camera measurements were obtained for each patient, giving three sets of 50 repeat measurements. The sample size was calculated to get a significance level of 0.05 and a power of 0.8 to detect a 10° difference. The difference between the three sets of measurements was analyzed with an ANOVA test for repeat measurements, with post-hoc comparisons with a paired
The treatment of medial knee osteoarthritis (OA) in conjunction with anterior knee laxity is an issue of debate. Current treatment options include knee joint distraction, unicompartmental knee replacement (UKR) or high tibial osteotomy with anterior cruciate ligament (ACL) reconstruction or total knee replacement. Bone-conserving options are preferred for younger and active patients with intact lateral and patello-femoral compartment. However, still limited experience exists in the field of combining medial UKR and ACL reconstruction. The aim of this study is to retrospectively evaluate the results of combined fixed-bearing UKR and ACL reconstruction, specifically with regard to patient satisfaction, activity level, and postoperative functional outcomes. The hypothesis was that this represents a safe and viable procedure leading to improved stability and functional outcome in patients affected by isolated unicompartmental OA and concomitant ACL deficiency. Fourteen patients with ACL deficiency and concomitant medial compartment symptomatic osteoarthritis were treated from 2006 to 2010. Twelve of them were followed up for an average time of 7.8 year (range 6–10 years). Assessment included Knee Osteoarthritis Outcome Score (KOOS), Oxford Knee score (OKS), American Knee Society scores (AKSS), WOMAC index of osteoarthritis, Tegner activity level, objective examination including instrumented laxity test with KT-1000 arthrometer and standard X-rays.
Introduction. Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes. Robotic-assisted (RA) total knee arthroplasty has demonstrated improved accuracy to plan in cadaver studies compared to conventionally instrumented (manual) TKA, but less clinical evidence has been reported. The objective of this study was to compare the three-dimensional accuracy to plan of RATKA with manual TKA for overall limb alignment and component position. Methods. A non-randomized, prospective multi-center clinical study was conducted to compare RATKA and manual TKA at 4 U.S. centers between July 2016 and August 2018. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons’ operative plan for overall limb, femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. We tested the differences of absolute deviation from plan between manual and RATKA groups using stratified
Introduction. A careful evaluation of new technologies such as robotic-arm assisted total knee arthroplasty (RATKA) is important to understand the reduction in variability among users. While there is data reviewing the use of RATKA, the data is typically presented for experienced TKA surgeons. Therefore, the purpose of this cadaveric study was to compare the variability for several surgical factors between RATKA and manual TKA (MTKA) for surgeons undergoing orthopaedic fellowship training. Methods. Two operating surgeons undergoing orthopaedic fellowship training, each prepared six cadaveric legs for cruciate retaining TKA, with MTKA on one side (3 knees) and RATKA on the other (3 knees). These surgeons were instructed to execute a full RATKA or MTKA procedure through trialing and achieve a balanced knee. The number of recuts and final poly thickness was intra-operatively recorded. After completion of bone cuts, the operating surgeons were asked if they would perform a cementless knee based on their perception of final bone cut quality as well as rank the amount of mental effort exerted for required surgical tasks. Two additional fellowship trained orthopaedic assessment surgeons, blinded to the method of preparation, each post-operatively graded the resultant bone cuts of the tibia and femur according to the perceived percentage of cut planarity (grade 1, <25%; grade 2, 25–50%; grade 3, 51–75%; and grade 4, >76%). The grade for medial and lateral tibial bone cuts was averaged and a
Introduction. Trabecular Titanium is a biomaterial characterized by a regular three-dimensional hexagonal cell structure imitating trabecular bone morphology. Components are built via Electron Beam Melting technology in aone- step additive manufacturing process. This biomaterial combines the proven mechanical properties of Titanium with the elastic modulus provided by its cellular solid structure (Regis 2015 MRS Bulletin). Several in vitro studies reported promising outcomes on its osteoinductive and osteoconductive properties: Trabecular Titanium showed to significantly affect osteoblast attachment and proliferation while inhibiting osteoclastogenesis (Gastaldi 2010 J Biomed Mater Res A, Sollazzo 2011 ISRN Mater Sci); human adipose stem cells were able to adhere, proliferate and differentiate into an osteoblast-like phenotype in absence of osteogenic factors (Benazzo 2014 J Biomed Mater Res A). Furthermore, in vivo histological and histomorphometric analysis in a sheep model indicated that it provided bone in-growth in cancellous (+68%) and cortical bone (+87%) (Devine 2012 JBJS). A multicentre prospective study was performed to assess mid-term outcomes of acetabular cups in Trabecular Titanium after Total Hip Arthroplasty (THA). Methods. 89 patients (91 hips) underwent primary cementless THA. There were 46 (52%) men and 43 (48%) women, with a median (IQR) age and BMI of 67 (57–70) years and 26 (24–29) kg/m2, respectively. Diagnosis was mostly primary osteoarthritis in 80 (88%) cases. Radiographic and clinical evaluations (Harris Hip Score [HHS], SF-36) were performed preoperatively and at 7 days, 3, 6, 12, 24 and 60 months. Bone Mineral Density (BMD) was determined by dual-emission X-ray absorptiometry (DEXA) according to DeLee &Charnley 3 Regions of Interest (ROI) postoperatively at the same time-points using as baseline the measureat 1 week. Statistical analysis was carried out using
INTRODUCTION. Navigation systems have proved allowing performing measurement of the lower limb axis with a good accuracy, but the mandatory use of reference pins or screws limit their use to the operating room. The use of non-invasive navigation systems has been suggested to overcome this limitation. We conducted a prospective study to assess the validity of such a measurement system with non-invasive fixation of the reference arrays. The main goal was to compare this method with a standard, invasive navigation system requiring bony fixation of the arrays. The following hypothesis was tested: there will be a significant difference between the simultaneous measurement of the mechanical femoro-tibial angle by a standard navigation system and by the non-invasive navigation system. MATERIAL AND METHODS. 20 patients scheduled for total or partial knee arthroplasty were included after giving their informed consent. There were 7 men and 13 women with a median age of 65 years (range, 55 to 90). The median coronal deformation measured by X-rays was 8° of varus (range, 5° valgus to 22 ° varus). The same navigation system was used for both invasive and non-invasive measurements, but the basic algorithms were adapted for the non-invasive technique. For the non-invasive technique, metallic plates were strapped on the thigh and the calf to allow arrays fixation (fig. 1). Coronal femoro-tibial mechanical angle (CMFA) in maximal extension without stress was recorded by the non invasive system. This non-invasive analysis was immediately followed by surgery, and the same angle was measured intra-operatively with the invasive system. Comparisons between non-invasive and invasive measurements were performed using a
Introduction. Revision Total Hip Arthroplasties (THA) have a significantly higher failure rate than primary THA's and the most common cause is aseptic loosening of the cup. To reduce this incidence of loosening various porous metal implants with a rough surface and a porous architecture have been developed which are said to increase early osteointegration. However, for successful osteointegration a minimal micromotion between the implant and the host bone (primary stability) is beneficial. It has not been previously determined if the primary stability for the new Gription® titanium cup differs from that of the old Porocoat® titanium cup. Material and Methods. In 10 cadaveric pelvises, divided into 20 hemipelvises, bilateral THA's were performed by an experienced surgeon (RGB) following the implant manufacturer's instructions and with the original surgical instruments provided by the company. In randomized fashion the well established Porocoat® titanium implant was implanted on one side of each each hemipelvis whereas on the corresponding opposite side the modified implant with a Gription® coating was inserted. Radiographs were taken to confirm satisfactory operative results. Subsequently, the hemipelvis and cups were placed in a biomechanical testing machine and subjected to physiological cyclic loading. Three-dimensonal loading corresponded to 30% of the load experienced in normal gait was imposed reflecting the limited weight bearing generally prescribed postoperatively. The dynamic testing took place in a multi-axial testing machine for 1000 cycles. Relative motion and micromotion were quantified using an optical measurement device (Pontos, GOM mbh, Braunschweig, Germany). Statistical evaluation was performed using the Wilcoxon signed-rank test. Results and conclusion. The standard Porocoat® titanium cups showed a mean relative motion with respect to the host bone of 54.74µm (Range 26.04 – 127.06µm), while the porous Gription® titanium cup displayed a relative motion with respect to the host bone of 49.77µm (Range 24.69 – 128.37µm). The
Introduction. Patients with hip osteoarthritis have a substantial loss of muscular strength in the affected limb compared to the healthy limb preoperatively, but there is very little quantitative information available on preoperative muscle atrophy and degeneration and their influence on postoperative quality of life (QOL) and the risk of falls. The purpose of the present study were two folds; to assess muscle atrophy and degeneration of pelvis and thigh of patients with unilateral hip osteoarthritis using computed tomography (CT) and to evaluate their impacts on postoperative QOL and the risk of falls. Methods. We used preoperative CT data of 20 patients who underwent primary total hip arthroplasty. The following 17 muscles were segmented with our developed semi-automated segmentation method: iliacus, gluteus maximus, gluteus medius, gluteus minimus, rectus femoris, tensor facia lata, adductors, pectinus, piriformis, obturator externus, obturator internus, semimenbranosus, semitendinosus, vastus medialis and vastus lateralis/intermedius (Fig. 1). Volume and radiological density of each muscle were measured. The ratio of those of affected limb to healthy limb was calculated. At the latest follow-up, the WOMAC score was collected and a history of falls after surgery was asked. The average follow- up period was 6 years. Comparison of the volume and radiological density of each muscle between affected and healthy limbs was performed using the
Introduction. Acetabular cup deformation is an important topic in today's THA and was investigated for a variety of metal cup designs (e.g. 1,2,3). Cup deformation caused by press-fit forces can have negative effects on the performance of such systems (e.g. high friction, metal ion release). When considering new materials for monolithic acetabular cups - such as ceramics - detailed knowledge about the deformation behaviour is essential to ensure successful performance. Therefore, the deformation behaviour of monolithic ceramic cups was investigated. Materials and Methods. Testing was conducted with monolithic ceramic cups (under development, not approved) of size 46mm and 64mm. One cup design of each size had a constant wall thickness of 3.0mm and an offset of 0.0mm (center of rotation on front face level), the other design was lateralized with an offset of 3.5mm (46mm) or 5.0mm (64mm), leading to an increased wall thickness. First, 3 cups of each design were impacted into 1.0mm underreamed Sawbones® blocks (pcf 30, geometry: see (2)). Second, all cups were quasi-statically assembled into the Sawbones® blocks of the same design using a material testing machine. Third, the cups were placed in a two-point-loading frame (acc. to ISO/DIS 7206–12:2014(E)) and a load of up to 1kN was applied. The inner diameter of all cups was measured under unloaded and loaded conditions for all scenarios using a coordinate measurement machine at 9 locations of each cup, 1.5mm below the front face (Fig.1). As the diametrical deformation (unloaded inner diameter – loaded inner diameter) was not normally distributed a
Introduction. Recent literature demonstrates that the assembly load to connect ball head and femoral stem affects the taper junction fretting wear evolution in THR [1]. During assembly the surface profile peaks of the mostly threaded tapers are deformed. This contributes to the taper locking effect. Very little is known about this deformation process and its role in the evolution of fretting and wear. Therefore, this study aimed to experimentally determine the deformation of the profile peaks after the initial assembly process. Materials and Methods. 36 tapers of three different stem materials acc. to ISO5832-3 (titanium), ISO5832-9 (steel), ISO5832-12 (cobalt chromium) and 36 ceramic ball heads were tested under quasi-static (4kN) and dynamic (impaction) (3.7±0.3kN) axial assembly. Before and after loading 4 surface profiles in 90° offset were measured on each taper. Height differences of profile peaks and areas under profile curves were calculated and compared. Both parameters provide insights into the deformation behavior of the surface structure. Additionally, subsidence of tapers into ball heads was measured and subsidence rates were calculated with regard to varying impaction forces. Due to different thermal expansion coefficients tapers could be disconnected from ball heads by utilizing liquid nitrogen. Thus, further surface damage due to disassembly was avoided. Statistical analysis was performed using a
An accurate evaluation of the mechanical properties of human tissue is key to understanding and successfully simulating (parts of) human joints. Due to the rapid post-mortem decay, however, the cadavers are usually frozen or embalmed. The main aim of this paper is to quantitatively compare the impact of both techniques on the biomechanical properties. To that extent, the Achilles tendons of seven cadavers have been tested. For each cadaver, one of the Achilles tendons was tested after being frozen for at maximum two weeks, whilst the other tendon was tested following a Thiel embalming process. All specimens were gripped in custom made clamps and subjected to uniaxial tensile loading. The specimens were scanned using a micro-CT to determine their cross-sectional area, which allowed transferring the applied forces to stresses. During the tensile tests, the specimens’ elongation was measured both using the digital image correlation (DIC) technique and using linear variable displacement transducers (LVDT's) mounted across the grips. The former allowed to assess the severity of slip in the grips. As is well described in literature, the obtained stress-strain relationship is not linear (Figure 1). Accordingly, the following bilinear relationship was fitted through the data points using a least squares fit:. s = E. 0. e e <= ê. s = E0 ê + E (e - ê) e > ê. As a result, the stress-strain response is sub-divided in two regions: a toe-region (e <= ê) with a low slope and stiffness (E. 0. ) and a linear elastic region (e > ê) with a higher stiffness (E). Both stiffness values were subsequently compared between the fresh frozen and Thiel embalmed group. Given the non-normal distribution of the test data, the non-parametric
Background:. To evaluate causes and results of revision arthroplasties in unstable total knee arthroplasties. Methods:. We retrospectively reviewed 24 knees that underwent revision arthroplasty for unstable total knee arthroplasty from December 2004 to December 2010. The mean age was 71.0(range, 54–85) years and the average follow-up period was 33.8 months (range, 6–70). The mean interval between the primary TKA and revision TKA was 82.5 months (range, 14–228). We classified the instability and analyzed the treatment according to its cases. Stress radiographs, postoperative component position and joint level were measured. Joint line position was measured using the fibular head as the reference point. Clinical outcomes were assessed using the Hospital for Special Surgery (HSS) score and range of motion.
Introduction. Postoperative knee flexion is an important indicator of success in total knee arthroplasty (TKA). Factors influencing the postoperative range of motion (ROM) were reported to be preoperative ROM, primary indication, height of postoperative joint line, patellar thickness, postoperative pain and rehabilitation. In this study, we aimed to identify the relationship between preoperative hip ROMs and postoperative knee flexion through reviewing the TKA results in Japanese patients. Patients & Methods. We retrospectively reviewed primary TKAs 55 knees in 55 patients (33 left and 22 right) between April 2012 and March 2013 inclusive. The patients were 11 men and 44 women, with a mean age of 76.7 years. Preoperative hip ROMs and perioperative knee flexion were measured by using goniometer. Hip ROMs were flexion, extension, abduction, adduction, external rotation; ER, internal rotation; IR and total rotation; TR (The total rotation added up ER and IR.). Hip ROMs were measured passively, with the pelvis was fixed manually. Postoperative knee flexion was measured in the fourth week. The patients were classified according to the good group (28 knees), the postoperative knee flexion was more than 125 degrees; and the poor group (27 knees), less than 120 degrees. We compared preoperative hip ROMs in each groups. Multiple regression analysis and Single regression analysis were used for comparison between preoperative hip ROMs and postoperative knee flexion. For comparisons between paired groups we used
The time at which patients should drive following total hip replacement (THR) is dependant upon recovery and the advice they are given. The Driver Vehicle and Licensing Agency (DVLA) in the United Kingdom does not publish recommendations following THR and insurance companies usually rely on medical instruction. Few studies have been performed previously and have reached different conclusions. Brake reaction times for patients undergoing primary THR were measured pre-operatively and at four, six and eight weeks after surgery using a vehicle driving simulator at a dedicated testing centre. Patients were prospectively recruited. Ethical approval was granted. Participants included eleven males and nine females, mean age 69 years. Side of surgery, frequency of driving and type of car (automatic or manual) were documented. Patients with postoperative complications were excluded. No adverse events occurred during the study. Statistical analysis using Friedman's test demonstrated a statistically significant difference (P=0.015) in reaction times across the four time periods.
INTRODUCTION. The magnitude of knee flexion angle is a relevant information during clinical examination of the knee, and this item is a significant part of every knee scoring system. It is generally performed by visual analysis or with manual goniometers, but these techniques may be neither precise nor accurate. More sophisticated techniques are only possible in experimental studies. Smartphone technology might offer a new way to perform this measurement with increased accuracy. MATERIAL. 20 patients operated on for unicompartmental or total knee replacement with help of a navigation system participated to the study. There were 13 women and 7 men with a mean age of 72.1 years. METHODS. All patients were operated on for unicompartmental or total knee replacement. All patients were operated on with help of a non-image based navigation system. The navigation system is able to measure very accurately the knee flexion angle. The Smartphone application allows measuring this angle in two steps 1) recording the reference position by putting the Smartphone on the operating table, 2) recording the knee flexion angle by putting the Smartphone against the tibial crest. Two observers participated to the study. The first observer performed three independent navigated measurements followed by three independent Smartphone measurements while positioning the knee under visual control in full extension, at 0°, 30°, 60°, 90° of knee flexion and at maximal flexion; the second observer performed only one set of measurements. The intra- and inter-observer variability was assessed by calculation of the intra-class correlation coefficient. Navigated and Smartphone data were compared by a paired
Introduction. Health Economists in Denmark have recently reported low and delayed return to work for patients treated for Sub-Acromial Impingement syndrome (SAIS) by Arthroscopic Sub-Acromial Decompression (ASAD). Surgeons however are reporting that patients achieve good pain relief and a high standard of activities of daily living (ADL) after surgery. Aim. To evaluate the effectiveness of ASAD for patients with SAIS and correlate clinical outcome with rate of return to work. Methods. Prospective cohort study and retrospective review of data from the Nottingham Shoulder database (presentation: 01/04/2008–30/06/2011). Inclusion criteria: Patients diagnosed clinically with SAIS by an experienced shoulder surgeon, who have failed conservative treatment (physiotherapy and sub-acromial injection), undergoing ASAD. Pre-operative and 6-month follow-up Oxford Shoulder Score (OSS) and Constant Score (CS) were compared. The rates of return to pre-operative level of work were also analysed. Statistical analysis:
Combined acetabular and femoral anteversion (CA) of the hip following total hip arthroplasty (THA) is critical to the hip function and longevity of the components. However, no study has been reported on the accuracy in restoration of CA of the hip after operation using robotic assistance and conventional free-hand techniques. The purpose of this study was to evaluate if using robotic assistance in THA can better restore native CA than a free-hand technique. Twenty three unilateral THA patients participated in this study. Twelve of them underwent a robotic-arm assisted THA (RIO® Robotic Arm Interactive Orthopedic System, Stryker Mako., Fort Lauderdale, FL, USA) and eleven received a free-hand THA. Subject specific 3D models of both implanted and non-implanted hips were reconstructed using post-operative CT scans. The anteversion and inclination of the native acetabulum and implanted cup were measured and compared. To determine the differences of the femoral anteversion between sides, the non-implanted native femur was mirrored and aligned with the remaining femur of the implanted side using an iterative closest point algorithm. The angle between the native femoral neck axis and the prosthesis neck axis in transverse plane was measured as the change in femoral anteversion following THA. The sum of the changes of the acetabular and femoral anteversion was defined as the change of CA after THA. A
Introduction. Leg length discrepancy is a significant concern after total hip replacement (THR). We hypothesised that the intra-operative use of a navigation system was able to accurately control the leg length during THR. Material. 50 cases have been prospectively analysed. There were 29 men and 21 women, with a mean age of 66.1 years (range, 50 to 80 years), all operated on for THR for end-stage hip osteoarthritis. Methods. All procedures were performed with a non-image based navigation system. The expected correction of the leg length was defined prior to the procedure. The leg length was recorded before any bone resection by the 3D-distance between the pelvic and the femoral navigation trackers when placing the operated leg in a position near the anatomic one. The THR was performed according to the indication of the navigation system. The vertical positioning of the femoral component and the length of the prosthetic neck were defined to achieve the expected planning; however a correction was allowed to compensate for excessive muscular tension or risk of prosthetic instability according to the surgeon's judgment. The final leg length was recorded with the same technique as previously, with an accurate control of the repositioning of the limb in the 3D space by the navigation system. The length variation before and after THR measured by the navigation system was compared to the planning and to a conventional radiographic measurement on plain, standing pelvic X-rays with a
Different femoral designs in TKA have shown multiple effects on the conformity of the patella-femoral joint. Historically, this anatomical relationship may interfere with clinical results. The objective of this study was to compare the reproducibility of a correct patello-femoral conformity in patients underwent TKA utilizing modern femoral implants. MATERIALS AND METHODS. We performed 50 consecutives TKA in fifty patients affected by knee arthritis utilizing the PFC Sigma System (De Puy, Warsaw, USA) with a new femoral design, having a prolonged anterior flange and a “smoother” throclea. The surgical procedure was performed utilizing the Sigma HP instrumentation to allow 3 degrees of external rotation of the femoral component and the “balanced gaps technique” was chosen. All patellae were replaced. All patients were evaluated preoperatively and at six months follow-up both clinically with the Knee society Score as well as radiografically: standing 30x90 cm. view, Merchant view, standard lateral view and a CT-scan with two millimeters cuts (Berger Protocol) at 20 degrees of flexion were all done. Particular attention was paid to the following CT measurements: patellar tilt, patellar conformity angle, patellar lateralization, femoral component external-rotation in relation to the patellar sitting. Statistical analysis was performed utilizing the t-test e the
