Aims

Optimal glenoid positioning in reverse shoulder arthroplasty (RSA) is crucial to provide impingement-free range of motion (ROM). Lateralization and inclination correction are not yet systematically used. Using planning software, we simulated the most used glenoid implant positions. The primary goal was to determine the configuration that delivers the best theoretical impingement-free ROM.

Shoulder septic arthritis is uncommon and frequently misdiagnosed, resulting in severe consequences. This study evaluated the demographics, bacteriological profile, antibiotic susceptibility, treatment regimens, and clinical outcomes. This is a 10-year retrospective observational analysis of 30 patients (20 males and 10 females) who were treated for septic arthritis of the shoulder. The data collecting process utilised clinical records, laboratory archives, and x-ray archives. We gathered demographic information, pre- and post-intervention clinical data, serum biochemical markers, and the results of imaging examinations. All patients had a surgical arthrotomy and joint debridement in the operating room, and specimens were taken for culture and sensitivity testing. The specimens were cultivated for at least seventy-two hours. Shoulder joint ranges of motion, comorbidities, and the presence of osteomyelitis were assessed clinically to determine the outcome. All statistical analyses were conducted using the STATA 17 statistical software. Analysis of correlation between categorical variables was performed using the chi-squared test. The majority of the study patients were black Africans (97%). The age range of the group was from 8 days to 17 years. At presentation, 33% of patients had a low-grade fever, whereas the majority (60%) had normal body temperature. The average length of symptoms was 3.9 days (ranged from 1 day to 15 days), and the majority of patients had an increased white cell count (83%) and C-reactive protein (98%). There was accumulation of fluid in the joint of all individuals who received shoulder ultrasound imaging. We noted a significant incidence of gram-positive cocci, which were mostly susceptible to first-line antibiotics. Shoulder stiffness affected 63% of patients and chronic osteomyelitis affected 50% of individuals. Neither the severity nor the duration of the symptoms was related to an increased risk of osteomyelitis. The results of this study revealed that the clinical characteristics and bacterial profile of septic arthritis of the shoulder conform to typical patterns. The likelihood of osteomyelitis and an unfavourable prognosis is considerable

Aims

Femoroacetabular impingement (FAI) patients report exacerbation of hip pain in deep flexion. However, the exact impingement location in deep flexion is unknown. The aim was to investigate impingement-free maximal flexion, impingement location, and if cam deformity causes hip impingement in flexion in FAI patients.

Introduction. Accurate acetabular position is an important goal during THA. It is also well known that accurate acetabular positioning is very frequently not achieved, even by experienced, high volume surgeons. Problems associated with cup malposition are: dislocation, accelerated poly wear, impingement, ceramic squeaking, metalosis. Murray et al described 3 methods of measurement and assessment of acetabular inclination and anteversion (I&A): anatomic, radiographic and operative. It is the hypothesis of the authors, that the differences and details of these 3 methods are poorly understood by many surgeons and this is contributory to inconsistent cup positioning. Additionally, the radiographic method, which is most commonly used for post op assessment and academic studies, contributes to misunderstanding and error. Modern computer guidance and software assessment of radiographs allows us to easily measure anatomic I&A which should be thought of as “true” I&A. Methods. The mathematical criteria for radiographic measurement of anatomic I&A are defined as well as the mathematical relationships and discrepancies between anatomic and radiographic I&A for any given cup. A. =. A. n. g. l. e.  . o. f.  . a. n. t. e. v. e. r. s. i. o. n.  . o. f.  . c. u. p. I. =. A. n. g. l. e.  . o. f.  . i. n. c. l. i. n. a. t. i. o. n.  . o. f.  . c. u. p. E = Angle of ellipse major diameter to horizontal. E = Radiographic inclination. Sin.  . A. =. H. o. r. i. z. o. n. t. a. l.  . w. i. d. t. h.  . o. f.  . e. l. l. i. p. s. e. L. e. n. g. t. h.  . o. f.  . e. l. l. i. p. s. e.  . m. a. j. o. r.  . d. i. a. m. e. t. e. r. Sin.  . I. =. V. e. r. t. i. c. a. l.  . h. e. i. g. h. t.  . o. f.  . e. l. l. i. p. s. e. L. e. n. g. t. h.  . o. f.  . e. l. l. i. p. s. e.  . m. a. j. o. r.  . d. i. a. m. e. t. e. r. Tan I = Tan E / Cos A. Tan E = (Tan I) x (Cos A). Results. Numerical values for radiographic I&A and anatomic I&A coincide for cups placed at 0 degrees anteversion. However, as cup anteversion increases, there is an exponentially increasing discrepancy between anatomic and radiographic inclination values with I always having a higher value than E. Commonly used radiographic inclination values (E) therefore always underestimate anatomic (true) inclination. Additionally, radiographic anteversion, except for 0 degrees anteversion, always underestimates anatomic (true) anteversion. Wear testing of cups by manufacturers and associated recommendations for cup positioning are based on anatomic measurement of inclination while surgeons now use a different method (radiographic) for measuring position. Axial CT analysis of cup anteversion agrees mathematically with anatomic anteversion and does not mathematically agree with the Murray radiographic criteria. Conclusions. Surgeons can intuitively understand that accurate radiographic measurement of femoral neck-shaft angle can only be done if the proximal femur is correctly rotated in relation to the x-ray beam, specifically the x-ray beam must be perpendicular to the plane determined by the intersection of the center lines of the neck and shaft. Any other femoral rotation will show a false increase in the neck shaft angle. Though less intuitive, true cup I is only represented by the angle seen on x-ray at only one A value, 0 degrees. Anteverting the cup as is desirable for THA stability creates a discrepancy between the apparent cup angle (E) and true inclination. Since the principles of solid geometry are widely adopted and accepted, the above results and conclusions are based on mathematical proof, not experimental findings. Erroneous conclusions such as “the cup position is good but the hip still dislocates” can be associated with a surgeon's lack of understanding of true I&A. Surgeons need to understand the differences between what they believe to be represented by x-rays and anatomic or true I&A as represented by the cup's position in relation to the body's transverse, coronal, and sagittal planes and x, y, and z axes. The authors believe that a surgeon's continued lack of understanding of the mathematics can be compensated for by the technologies of computer guidance and/or software analysis of cup x-rays

Background: Postural re-training is one element used in the physiotherapeutic management of spinal disorders. Clinicians need outcome measures that are accurate, reliable and easy to use to monitor effects of treatment and to provide justification for the management of these conditions. This study aimed to assess the reliability of digital video analysis of thoracic, neck and head tilt angles using one measurer within one day. Methods: Twenty healthy subjects were recruited. L4, C7 spinous processes and tragus were marked on the skin and identified with reflective markers. The subject sat in a relaxed comfortable position in a chair and was video recorded from a lateral view for one minute. The markers were removed and the subject rested, in a chair, for a few minutes. Two further recordings were taken in the same day. Still images were taken at 30seconds of the recording and were analysed using a bespoke programme within MATLAB software. Analysis included Intraclass Correlation Coefficients (ICCs) and Bland Altman plots. Results: Excellent reliability was ascertained for thoracic, neck and head tilt angles identified by ICC of 0.94 (mean difference 0.34° ±4.7°), 0.91 (mean difference 1.1°±3.7°) 0.84 (mean difference 0.9°±4.9) respectively. All points, except one for neck angle and head tilt angle and two for thoracic angles, were within 95% limits of agreement. Conclusion: Digital video analysis using MATLAB is a reliable way to measure thoracic, neck and head tilt angles. This is an inexpensive method for measuring posture that could be used in the management of people with spinal disorders. Conflict of Interest: None. Source of Funding: This study has been financially supported by the Physiotherapy Research Foundation, UK and Research Collaboration Building Capacity Wales (rcbc Wales)

Aims

Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone.

The pattern of injury to the carpal ligaments following wrist trauma is unclear. Different imaging techniques often prove inconclusive rendering the diagnosis difficult and hence the treatment controversial. This study aimed to observe and evaluate the differences in scapholunate kinematics before and after sectioning the scapholunate interosseous ligament (SLIL) and radioscaphocapitate ligament (RSC). Twenty two embalmed cadaveric wrists were used. There were four males and seven females with an average age of 84 years. Their medical records confirmed the absence of previous history of wrist diseases or injuries. The extensor and flexors tendons of the wrist were removed leaving the capsule intact. Two drill bits (1.5 mm) were used to make a hole each in scaphoid and lunate, one centimeter apart. The drill bits were left in the bones to act as metal wires for calibration. Each wrist was moved through a set of motions and each movement was performed thrice; first one with the ligaments intact, second with SLIL sectioned and the last one with RSC excised. Digital photographs were taken and angles measured with MB Ruler software. Analysis of variance was done using SPSS 12. There was no angle between the metal pointers when the ligaments were intact. There was movement and change in angle detected when SLIL and RSC were sectioned. The sectioning of the SLIL lead to a significant increase in the angle between the pointers in all the movements recorded (p value < 0.001). Subsequent sectioning of the RSC further increased this angle but this increase was much smaller compared to that after sectioning SLIL. On completion of the measurements the wrist capsule was opened to reveal that both the ligaments had been successfully sectioned and there were no degenerative changes in the bones or ligaments in any wrist. This first cadaveric evaluation of alterations in scapholunate motion with sectioning of SLIL and RSC revealed that SLIL has a significant influence on the scapholunate kinematics, where as sectioning of the RSC has little additional effect. This in-vivo finding might have implications of importance of preserving SLIL during wrist surgeries and its role in management of carpal instabilities

The management of proximal humeral fractures is determined by fragment displacement. Intra-operative and radiological classification systems have been proposed, namely AO and the Neer classifications to assess therapeutic options. This study evaluates the usefulness of these classification systems by the creation of physical 3D models using a rapid prototyping technique avoiding the problems associated with 3D illusions on a 2D screen. Seven consecutive patients with complex fractures of the proximal humerus were investigated using the data from multi-sliced spiral CT scans. Fractures associated with dislocation were excluded. The data from these CTs was segmented to reveal the anatomy of interest and converted to a stereolithographic format from which the physical models could be made of the proximal humerus via a laser guided filament deposition process. Further manipulation with software allowed angulation and displacements of fragments to be measured. Inter-observer agreement: All models were assessed by three surgeons. A consultant with a special interest in shoulder surgery, a fellowship trained surgeon and a senior house officer in basic surgical training. Independent assessment of the fractures from the models was made using the Neer and AO classifications. In only 1 incidence did all 3 observers agree on the classification, in 5 incidences only two observers agreed and on 8 occasions none of the observers agreed. Indeed there were 9 occasions that at least one observer thought the fracture pattern could not be applied to a classification. Fracture Patterns: Observation of the individual models together with measurements of angulation and displacement by further software analysis, demonstrated major subtypes namely valgus and varus angulation with minimal displacement of the greater tuberosity. Appreciation of the integrity of the medial hinge and buckling could be made in relation to the different fracture patterns. This study highlights concerns on the validity of current classification systems. It also questions whether the existing systems reflect the pathophysiological subtypes of these fractures allowing comparison of surgical results in order to evaluate treatment options

Since cementless stem fixation in hip arthroplasty is becoming more and more common, the overall incidence of intraoperative femoral fractures has risen considerably. Depending on primary or revision arthroplasty, literature reports fracture rates between a few percent up to one third of the cases. In this study, methods commonly applied in the field of structural testing were customized for this specified interference fit situation. A cementless hip system (ABG II, Stryker) was used on animal bones and biomechanical bones. Transient excitation in the form of regular hammer strokes and sinusoidal excitation using a shaker served as an input. The output of the system under test was measured on the greater trochanter using a piezoelectric accelerometer. The signals were digitized with a high-speed data acquisition system and analyzed in real-time with spectrum analysis software. Analysis included threshold detection in the time domain to determine the time delay between the input and output transducer. Spectrum analysis in the frequency domain included FFT analysis and frequency response function analysis to identify shifts of fundamental frequencies and harmonics to describe the vibrational changes with increasing stability. A digital imaging system was set up to take pictures of the metal-bone site to measure inducible displacement with each hammer impact and correlate it with the vibrometry results. Furthermore a strain gauge circularly mounted around the proximal femur monitored accurately any hairline fracture. This study shows that changes of the vibrational spectrum are directly related to implant fit. The range of interest is well in the sonic range, which apparently is the reason for many surgeons to listen and ‘feel’ carefully during advancing the broach or the final implant into the femur. The study is trying to extract critical vibrational parameters correlated with stability and femoral integrity. Due to the different dimensions of the tested animal bones and lack of soft tissue damping, further experiments on cadavers need to be carried out. Vibrational spectrum analysis could prove to be a useful tool to readily assess implant stability and femoral integrity. It seems to be most beneficial in revision surgery or minimally invasive hip replacement, where the risk of femoral fractures is increased or fissures could easily be missed

This study aims to evaluate the development of deformity in patients with hypophosphataemic rickets and the evolution of the orthopaedic management thereof. Fifty-four patients had undergone treatment for hypophosphataemic rickets at our institution since 1995. Clinical records for all patients were obtained. Forty-one patients had long leg radiographs available that were analysed using Traumacad™ software. Statistical analysis was performed using SPSS 23 (SPSS Inc., Chicago, Illinois, USA). Of the 41 patients, 18 (43%) had no radiographic deformity. 20 have undergone bilateral lower limb surgery for persistent deformity (Mechanical Axis ≥ Zone 2). A further 3 patients are awaiting surgery. Six patients (12 limbs, 14 segments) had osteotomies and internal fixation as primary intervention: only one limb developed recurrent deformity. There were no major complications. Fourteen patients (28 limbs) had 8-plates (Orthofix, Verona) applied. In 5 limbs correction is on-going. Neutral alignment (central Zone 1) was achieved in 14/20 (70%) patients. Two patients required osteotomy and external fixation for resistant deformity. The mean rate of angular correction following 8-plate application was 0.3 and 0.7 degrees/month for the tibia and femur respectively. The mean age at 8-plate insertion was 10.25y (5–15y). Patients with more than 3 years of growth remaining responded significantly better than older patients (Fisher Exact Test, p=0.024). Guided growth was more successful in correcting valgus deformity than varus deformity (Fisher Exact Test, p=0.04). In the younger patients, diaphyseal deformity corrected as the mechanical axis improved at the rate of 0.2 and 0.7 degrees /month for the tibial and femoral shafts. Serum phosphate and alkaline phosphatase levels did not affect response to surgery or complication rate. Guided growth by means of 8-plates is a successful in addressing deformity in hypophosphataemic rickets. Surgery is best performed in patients with more than 3 years of growth remaining

Aims

The study aimed to determine whether the microRNA miR21-5p (MiR21) mediates temporomandibular joint osteoarthritis (TMJ-OA) by targeting growth differentiation factor 5 (Gdf5).

Spinal Biomechanics Lab, Baylor College of Medicine, Houston, Texas, USA. Documenting the patterns and frequency of collapse in non-operatively managed spine fractures, using a motion analysis software. Retrospective analysis of prospective case series. 105 patients with thoracic or lumbar fractures, were neurologically intact, and treated non-operatively for the ‘stable’ injury at our unit between June 2003 and May 2006. The mean age of the cohort was 46.9 yrs. Serial radiographs (mean 4 radiographs/patient; range 2 – 9) were analysed using motion analysis software for collapse at the fracture site. We defined collapse as a reduction of anterior or posterior vertebral body height greater than 15% of the endplate AP width, or a change in the angle between the inferior and superior endplates > 5°. The changes were assessed on serial radiographs performed at a mean of 5.6 mo (95% CI 4.1 – 7.1 mo) after the initial injury. 11% showed anterior collapse, 7.6% had posterior collapse, 14% had collapse apparent as vertebral body wedging, and 17% had any form of collapse. ODI scores were obtained in 35 patients at the time of the last available radiograph. There were no significant differences in ODI scores that could be associated with the presence of any form of collapse (p > 0.8 for anterior collapse; and p = 0.18 for posterior collapse). This pilot study with the motion analysis software demonstrates that some fractures are more likely to collapse with time. We hope to carry this work forward by way of a prospective study with a control on other variables that are likely to affect the pattern and probability of post-fracture collapse, including age, bone density, vertebral level, activity level, fracture type

Clinical proteomics is an exciting new sub-discipline of proteomics that involves the application of proteomic technologies at the bedside to identify new biomarkers, associated with specific diseases. In this study to compare serum protein profiles between identical age-matched groups of fracture and non-fracture controls, we looked at the initial proteomic profile of 10 patients who had fractures and compared them to age-matched controls to see if there was any specific difference indicative of fracture. Materials and Methods. 10 patients with single fractures of the long bones, wrist or ankle gave a blood sample upon presentation at the fracture clinic. 10 healthy, age-matched, non-fracture volunteers also donated blood. Plasma was isolated and the albumin and IgG fractions removed before loading equal amounts of each sample onto 2 dimensional polyacrylamide gels for analysis by isoelectric point in the first dimension and molecular mass in the second dimension. Protein profiles between fracture patients and non-fracture controls were contrasted using Phoretix 2D analysis software. Data analysis differentiated between the average gel of the patient group and the average gel of the control group. More than 300 protein spots were observed in both the control and patient group. Seven protein spots were identified which showed a statistically significant (p<0.05) difference between the control and patient samples. Of these, three spots (X, Y, Z) were clear, distinct and present in at least 80% of these gels. All the three spots were up regulated in the patient group as opposed to the control group. These proteins are currently being investigated further by MALDI-TOF TOF for specific protein identification. Discussion. Proteomic analysis is already a powerful tool in the identification of disease markers. We aim to show here that there are differences seen in blood plasma profiles in fracture patients compared to non-fracture healthy controls. The differences seen may help us to understand the fracture repair process better

Purpose of the study: The purpose of this prospective randomised study was to evaluate the wear of cemented polyethylene cups as a function of the material of the femoral head: oxinium versus metal. Material and methods: This series included 50 primary arthroplasties implanted from January 2006 to May 2006 in 50 patients (27 women and 23 men), mean age 60.6±11.4 years (21–75). The same femoral piece made of highly polished M30NW stainless steel with a quadrangular section was used for all implants. Similarly, all patients had a polyethylene cup sterilised with ethylene oxide (CMK21, Smith and Nephew). The femoral head was made of stainless steel for 25 hips and oxinium for 25 hips. The major outcome was penetration of femoral head into the cup (associated with true wear and creep) measured at minimum two years follow-up using the Martell method modified according to the recommendations of the author for an all-polyethylene cup. Patient-related and technique-related factors were studied. Non-parametric tests were used for the statistical analysis. Results: There was no significant difference between the two groups regarding preoperative data. Two patients died, one was lost to follow-up; for three patients, the radiographs were excluded by the software. The analysis thus included 44 hips with a median follow-up of 2.01 years (1.9–2.3), 22 in the Oxinium™ group and 22 in the metal group. The median penetration rate was 0.16 mm/year in the Oxinium. ®. group versus 0.19 mm/year in the metal group (Mann-Whitney, p=0.46). Annual volumetric penetration in the Oxinium™ group was comparable with that of the metal group (Mann-Whitney, p=0.76). conversely, using the radiograph taken at one year as the reference value (true wear), wear was 0.066 mm/y in the Oxinium™ group versus 0.19mm/y in the metal group (Mann-Whitney, p=0.38). Discussion and Conclusion: The results of this series indicate that using an oxinium femoral head reduces polyethylene wear. Mid-term results appear to be necessary to confirm these findings

INTRODUCTION. Biomaterial-related infections are an important complication in orthopaedic surgery [1], and Staphylococcus sp. accounts for more than half of the prosthetic joint infection cases [2]. Adhesion of bacteria to biomaterial surfaces is a key step in pathogenesis of such infections [3]. Titanium alloys are widely used in orthopaedic implants because their biocompatibility [4]. Surface incorporation of ions with antimicrobial properties, like fluorine, is one strategy previously studied with good results [5]. MATERIAL AND METHODS. A 18mm diameter rod of Ti–6Al–4V alloy ELI grade according to the standard ASTMF136-02 supplied by SURGIVAL was cut into 2 mm thick disk specimens, ground through successive grades of SiC paper to 1200 grade, degreased with a conventional detergent and rinsed in tap water followed by deionised water. The specimens were then chemically polished (CP). The disks were anodized only on one side by using a two electrode cell in a suitable electrolyte. TiO. 2. barrier layers, without fluoride (BL), were produced by anodizing in 1 M H. 2. SO. 4. at 15 mA cm-2 to 90 V, reaching 200 nm of thickness. Fluoride barrier layers (FBL) were produced in an electrolyte containing 1 M NH. 4. H. 2. PO. 4. and 0.15 M NH. 4. F, at constant voltage controlled at 20 V for 120 min at 20°C; the thickness of the layer is 140 nm. Laboratory biofilm-forming strains of Staphylococcus aureus 15981 [6] and Staphylococcus epidermidis ATCC 35984 were used in adherence studies, which were performed using the protocol by Kinnari et al [7]. Photographs obtained were studied by ImageJ software. Statistical analysis was performed by EPI-INFO software. The experiments were performed in triplicates. RESULTS. Lower adherence was detected when compared FBL with unmodified controls (CP and BL). A statistical significant difference (p<0.01) was detected in the adhesion to modified material between both species, being the adherence of S. aureus lower than that of S. epidermidis (Figure 1). DISCUSSION & CONCLUSIONS. There is currently a discussion about the actual antibacterial properties of fluorine when incorporated in biomaterial surfaces. In this study we have demonstrated that both S. aureus and S. epidermidis strains showed a decrease of bacterial adhesion to modified surfaces with fluorine, a decrease that cannot be due to other surface modifications. Further studies, including adhesion studies with clinical strains [8], must be performed to confirm these results, which can lead to the development of new materials with a potential use in orthopaedic surgery

Introduction: Notching of the femoral neck during preparation of the femur during hip resurfacing has been associated with an increased risk of femoral neck fracture. We aimed to evaluate this with the use of a finite element model. Methods: A three dimensional femoral model was used and molded with a femoral component constructed from the dimensions of a Birmingham Hip Resurfacing. Multiple constructs were made with the component inferiorly translated in order to cause a notch in the superior femoral neck. The component angulation was kept constant. Once constructed the model was imported into the Ansys finite element model software for analysis. Elements within the femoral model were assigned different material properties depending on cortical and cancellous bone distributions. Von Misses stresses were evaluated near the notches and compared in each of the cases. Results: In the un-notched case the maximum Von Mises stress was only 40MPa. However, with the formation of a 1mm notch the stress rose to 144MPa and in the 4 mm notch the stress increased to 423MPa. These values demonstrated that a 1mm notch increased the maximum stress by 361% while a 4mm notch increased the maximum stress by 1061%. Discussion: This study demonstrated that causing a notch in the superior femoral neck dramatically increases the stress within the femoral neck. This may result in the weakening of the femoral neck and potentially predispose it to subsequent femoral neck fracture. The data suggests that even a small notch of 1mm may be detrimental in weakening the femoral neck by dramatically increasing the stress in the superior neck. This study suggests that any femoral neck notching should be avoided during hip resurfacing

Introduction:. This study evaluates the impact of radii-related differences in posterior cruciate ligament retaining (PCR) primary total knee arthroplasty (TKA) prosthetic designs on knee biomechanics during level walking 1-year after surgery. The multi-radius (MR) design creates at least two instantaneous flexion axes by changing the radius of curvature of the femoral component throughout the arc of knee motion. The femoral component of the single-radius (SR) design has only one radius and therefore a fixed axis. Methods:. Subjects scheduled for computer-navigated TKA (n = 37: SR n = 20 [9M, 11F], MR n = 17 [8M, 9F]; 69.8 ± 7.1 years, 87.6 ± 20.8 kg, 1.68 ± 0.09 m), and demographic-matched controls without knee pathology n = 23 [13M, 10F], provided informed consent under the Banner IRB (Sun Health panel). All surgical subjects received similar pre-, peri-, and post-operative care under the direction of three surgeons from a single orthopedic practice. Position and force data were collected using 28 reflective markers (modified Helen Hayes [Kadaba et al 1990]) tracked by ten digital IR cameras (120 Hz) (Motion Analysis Corp., Santa Rosa, CA) and four force platforms (1200 Hz) (AMTI, Watertown, MA) embedded in an 8m walkway. Data were recorded and smoothed (Butterworth filter, 6 Hz) using EVaRT 5.0.4 software (Motion Analysis Corp.). Gait cycle parameters were calculated using the ‘Functional Hip Center’ and ‘Original Knee Axis’ models in Orthotrak 6.6.1 (Motion Analysis Corp.). Data from each group were height and weight normalized and ensemble averaged by affected limb (right limb for controls) using custom code written in Labview (National Instruments Corp, Austin, TX). Descriptive statistics for the maximum and minimum knee kinematic, kinetic, and temporal spatial values in the stance and swing phases of the gait cycle were generated for each group. Between-group comparisons were made using an ANOVA with post hoc testing as appropriate (SPSS 14.0 (SPSS Inc, Chicago, IL)). Results:. Total range of motion was similar between surgical groups but MR was 5° more extended than SR throughout stance (p < 0.05) (Figure 1). MR knee power absorption (Figure 2) and medial knee force were less than controls (p < 0.05). SR and controls were similar for several knee parameters (p > 0.05) (Table 1). Discussion:. The performance of the SR design was more control-like in several parameters at one year. A shifting radius of curvature, which alters patella-femoral moment arm geometry and resulting quadriceps force [D'Lima et al 2001], may contribute to reduced knee power in the MR group. The fluctuating radius of curvature may also generate collateral ligament laxity with increasing flexion angles [Wang et al 2005, Whiteside et al 1989] contributing to the observed deficit in medial knee forces. The increased knee extension angles in the MR group are indicative of a stabilizing adaptation throughout the range of motion. While previous biomechanics studies following TKA have revealed few to no significant differences in gait performance due to implant design, the use of computer navigation and standard order sets, which control for alignment and other confounding variables, may generate tighter data sets that reveal differences masked by variation within surgical groups rather than between them

To assess the efficacy of software assisted correction using six axes analyses for Blounts deformity. Between 1998 and 2000, 22 tibiae in 19 patients underwent correction of Tibia Vara with the TSF. There were six females and thirteen males. There were 8 infantile and 14 adolescent forms. The mean patient age was 9.9 years (3–16 years). Shortening was present in 18 patients, averaging 11 mm (range: 3–30 mm). The mean follow up was 2.8 years (range: 2–4.1 years). The mean preoperative varus deformity was 16.5 degrees (range, 8 to 50 degrees) which improved to 0 degree (−2 to 2 degrees), and mean procurvatum deformity was 12.2 degrees (2 to 21 degrees) which improved to 0.1 degree (−2 to 3 degrees). The plane of the deformity was an average of 31 degrees (0 to 62 degrees) from the coronal plane and the mean magnitude of the deformity was 20.5 degrees (11.3 to 3.8 degrees). Taylor spatial frame uses the six axes software assisted analysis to correct complex deformities such as Blounts disease. It is very effective in correcting the Blounts deformity and has minimal complications

Introduction. Minimally invasive, computer navigated techniques are gaining popularity for total knee replacement (TKA). While these techniques may have the potential to provide improved functional outcomes with more rapid recovery, little quantitative data exists comparing long-term gait function following surgery with different exposure approaches. This study compares functional gait differences between surgical approach groups two year following TKA. Kinetics, kinematics, and temporospatial parameters were assessed to determine if differences exist between groups in long term follow-up. Methods. This study was approved by the Banner IRB (Sun Health Panel). 95 subjects volunteered to participate in the study and signed informed consent prior to testing. The subjects were prospectively randomized to one of four surgical approach groups, mini-midvastus (MV), mini-subvastus (SV), mini-parapatellar (MP), and standard parapatellar (SP). These subjects were also compared to 45 age-matched, asymptomatic controls. Surgery was performed by one of two fellowship trained orthopedic surgeons specializing in adult reconstruction. Subjects were assessed in the gait laboratory two years after receiving surgery. Three dimensional kinetic and kinematic data were captured using a ten-camera passive marker system, a modified Helen Hayes marker set (Eagle-4, Motion Analysis, Santa Rosa, CA), and four floor embedded force platforms (AMTI Inc., Watertown, MA). Subjects were instructed to walk at a self selected speed down an 8 meter walkway. Kinetic and kinematic data were post processed using EVaRT and OrthoTrak 6.23 biomechanical software (Motion Analysis, Santa Rosa, CA). Statistical analyses were performed using SPSS (v14.0, SPSS Inc, Chicago, IL) and included a one-way ANOVA and post hoc testing. Results. 50 subjects returned for a two year gait analysis. Selected results are provided in Table 1. All approach groups regained near normal knee function compared to age matched controls. Motion analysis provided specific statistical differences between parameters about the knee and hip. The MV approach group maintained greater flexion than other groups at the knee and hip throughout the gait cycle. The MP group maintained the most extended knee postures throughout the task with significant differences from controls being noted during peak flexion in swing (p = 0.039) and at foot strike (p = 0.034). They also had reduced external knee rotation angles (p = 0.010) and a larger pelvic rotation range of motion (p = 0.020). Although not significant, the MP group had a concurrent increase in pelvic obliquity on the operative limb during weight acceptance. The MP group also had the highest velocity, cadence, stride length, and the earliest toe off when compared to other groups. Discussion. The results indicate that there are subtle differences in gait strategy between approach groups at the two year time point. The MV group maintains increased flexion angles at the hip and knee throughout the gait cycle which could be characterized as a “bent-hip bent-knee” gait. This could be due to differences in capsular and muscle scarring between the different surgical approach groups. The MP approach group maintained more extended knee postures with improved velocity, cadence, and stride length. No differences in pain were detected in clinical scores

Introduction: Mobile bearing total knee arthroplasty (TKA) has been developed to theoretically provide better, more physiological function of the knee and produce less PE wear. The theoretical superiority of mobile bearing TKAs over fixed bearing devices has not yet been proven in clinical studies. The objective of the present study was to prospectively analyze clinical and functional outcomes of randomized fixed and mobile bearing total knee arthroplasty patients by means of gait analysis, electromyography and established clinical scores. Methods: In a prospective, randomized, patient- and observer-blinded, clinical study, 33 patients (mean age 63 years) received a cruciate retaining Genesis II TKA for primary osteoarthritis. 16 patients received a mobile bearing and 17 patients a fixed bearing device. The day before surgery and 24 months postoperatively, established clinical (KSS, HSS, WOMAC, UCLA, VAS) and quality of life (SF-36) scores were used to compare both patient groups. Electromyography of standardized locations was measured with the MyoSystem 2000 and analyzed with Myoresearch software. Gait analysis was performed with a six camera motion analysis system and force platforms. Results: Both groups showed significant improvements between pre- and postoperative evaluation in gait analysis and electromyography, but gait analysis results as well electromyography did not show any difference between both groups at follow-up. Clinical and quality of life results significantly improved from pre- to postoperative evaluation, but only the Knee Society Score showed a significant superiority of the mobile bearing group (mean 159.0; SD 27.7; range, 105–196) over the fixed bearing group (mean 134.4; SD 41; range, 56–198) (p=0.0022). Conclusions: In the present study, no functional advantage of mobile bearing TKA over fixed bearing devices could be found, although the mobile bearing group had better clinical results. Thus, long-term clinical results and in-vivo wear analyses have to be followed, and more subtle functional analyses (e.g. fluoroscopy) have to be employed to finally judge over the theoretical advantage of mobile bearing TKAs