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.

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.

Aims

Open tibial fractures are limb-threatening injuries. While limb loss is rare in children, deep infection and nonunion rates of up to 15% and 8% are reported, respectively. We manage these injuries in a similar manner to those in adults, with a combined orthoplastic approach, often involving the use of vascularised free flaps. We report the orthopaedic and plastic surgical outcomes of a consecutive series of patients over a five-year period, which includes the largest cohort of free flaps for trauma in children to date.

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).

Aims

We quantitatively compared the 3D bone density distributions on CT scans performed on scaphoid waist fractures subacutely that went on to union or nonunion, and assessed whether 2D CT evaluations correlate with 3D bone density evaluations.

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

Aims

The purpose of this study was to determine the sensitivity, specificity and predictive values of previously reported thresholds of proximal translation and sagittal rotation of cementless acetabular components used for revision total hip arthroplasty (THA) at various times during early follow-up.

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

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

The success of total knee replacement (TKR) depends on optimal soft-tissue balancing, among many other factors. The objective of this study is to correlate post-operative anteroposterior (AP) translation of a posterior cruciate ligament-retaining TKR with clinical outcome at two years. In total 100 patients were divided into three groups based on their AP translation as measured by the KT-1000 arthrometer. Group 1 patients had AP translation < 5 mm, Group 2 had AP translation from 5 mm to 10 mm, and Group 3 had AP translation >  10 mm. Outcome assessment included range of movement of the knee, the presence of flexion contractures, hyperextension, knee mechanical axes and functional outcome using the Knee Society score, Oxford knee score and the Short-Form 36 questionnaire.

At two years, patients in Group 2 reported significantly better Oxford knee scores than the other groups (p = 0.045). A positive correlation between range of movement and AP translation was noted, with patients in group 3 having the greatest range of movement (mean flexion: 117.9° (106° to 130°)) (p < 0.001). However, significantly more patients in Group 3 developed hyperextension > 10° (p = 0.01).

In this study, the best outcome for cruciate-ligament retaining TKR was achieved in patients with an AP translation of 5 mm to 10 mm.

Objectives

This study aimed to investigate time-dependent gene expression of injured human anterior cruciate ligament (ACL), and to evaluate the histological changes of the ACL remnant in terms of cellular characterisation.

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. 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

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

Previous studies (. Chen et al., 2003. ; . Kaufmann et al., 2001. ) have shown that persons with osteoarthritis (OA) walk more slowly with lower cadence, have lower peak ground reaction forces and load their injured limb at a lower rate than healthy age matched subjects. However, another study (. Mündermann et al., 2005. ) found that patients with severe bilateral OA loaded their knee joint at a higher rate. They also found these patients had higher knee adduction moments and lower hip adduction moments. It has been reported (. McGibbon and Krebs 2002. ) that when subjects with knee OA are required to walk at the same speed as healthy subjects they generate more power at the hip joint to help overcome reduced knee power and aid in the advancement of the leg prior to the swing phase of the gait cycle. . Myles et al. (2002). reported that patients with knee OA have reduced knee range of motion during walking. This paper presents detailed kinematic and kinetic data collected on a large group of patients with advanced knee osteoarthritis to show the differences in the gait of these patients just prior to surgery compared with age-matched control group. This study was approved by the Sun Health Institutional Review Board. Subjects volunteered to participate in the study and signed informed consent prior to testing. Subjects were excluded if the had significant diseases of the other joints of the lower extremity or a diagnosed disorder with gait disturbance. Motion data was captured using a ten-camera motion capture system (Motion Analysis Corp., Santa Rosa, CA). Three-dimensional force data was recorded using four floor embedded force platforms (AMTI Inc., Watertown, MA). Patients were asked to walk at a self selected speed along a 6.5 meter walkway. A minimum of five good foot strikes for each limb were recorded. Data were collected using EVaRT 5 software (Motion Analysis Corp., Santa Rosa, CA) and analyzed using OrthoTrak 6.2.8 (Motion Analysis Corp., Santa Rosa, CA) and MatLab software (The Mathworks Inc., Natick, MA). Statistical analysis was performed using SPSS 14.0 software (SPSS Inc., Chicago, Il) (α = 0.05). Eighty-six patients (71 ± 7 years) along with sixty-four control subjects (65± 10 years) volunteered to participate in the study. All measured temporal and spatial parameters showed significant differences between the OA patients and the control group. The OA patients were found to walk at a significantly lower velocity (p< .01) and cadence (p< .01) using a wider step width (p< .01) than the control subjects. Patients had their injured knee significantly more flexed at foot strike (p< .01) but flexed the knee significantly less during swing (p< .01) when compared to the control group. Patients had significantly higher knee flexion angles as well as hip flexion and abduction angles during stance. Knee varus angles were significantly higher for the OA patients during stance (p< .01) but not during swing when compared to the control group. Significant increases in pelvic tilt and pelvic obliquity were measured during the stance phase. Hip abduction angles during stance were significantly lower for the OA group. Patients generated significantly lower vertical ground reaction forces during stance (p< .01) while sagittal plane kinetic analysis showed significantly lower external knee flexion moments (p< .01) and knee power generation (p< .01) during this phase of the gait cycle. Analysis of frontal plane angles showed OA patients had a significantly higher maximum knee varus angle during stance as well as generating a higher external knee varus moment (p=.03) during this phase of the gait cycle. Changes in gait measured in this study support and enhance findings from previous studies. OA patients appeared to walk with a more crouched posture with higher knee and hip flexion angles through mid stance. This along with lower velocity and cadence and a larger step width would indicate a desire for more stability while walking. Patients also flexed their knees more at foot strike in an attempt to absorb the forces generated during weight acceptance. While knee flexion angles measured for the OA group were similar to the control subjects during the initial period of stance, the OA patients did not extend their knees as much during mid stance indicating a desire to reduce the angular rotation of the knee while in single support. Changes measured in frontal plane angles of the hip and pelvis may be an attempt to compensate for the different angles generated by the knee during stance. The differences in hip and knee angles measured during stance for patients and controls allowed patients to have reduced peak external knee flexion moments during initial stance but a higher knee flexion moment at mid stance. The reduction in knee angular change during stance and the reduced cadence meant power absorption during early and late stance and generation during mid stance was much lower for the OA patients than the control group. All the changes noted appear to be designed to limit the movement of the knee joint while loaded and reduce the peak loads in an effort to reduce pain at the affected joint while at the same time increase stability during gait. These data show the differences that exist between the gait patterns of patients with advanced osteoarthritis and healthy age-matched persons and highlight the changes that are necessary following knee replacement surgery and rehabilitation to return the gait of these patients to normal

Total knee arthroplasty (TKA) is a common surgery to relieve knee pain and increase range of motion due to osteoarthritis (OA) in older patients. Minimally invasive, computer navigated techniques are gaining popularity for knee replacement surgery. These techniques may have potential to provide better functional outcomes over a shorter period of time. Little data exists comparing the early functional recovery of patients following total knee replacement surgery performed using various common approaches. This study compares the functional gait of patients two months after surgery performed using one of four common approaches to determine if differences exist in the immediate recovery. This knowledge will aid surgeons determine the best approach to use when performing surgery. This study was approved by the appropriate Institutional Review Board. Subjects volunteered to participate in the study and signed informed consent prior to testing. Subjects were excluded if the had significant diseases of the other joints of the lower extremity or a diagnosed disorder with gait disturbance. Patients were randomly assigned to receive unilateral primary TKA using standard parapatellar, mini-parapatellar, mini-midvastus, or mini-subvastus approaches. All patients received the same preoperative, perioperative, and postoperative critical pathways and standard orders. All incisions were five inches and all patients and examiners blinded to type of approach. Surgery was performed by one of two fellowship trained orthopedic surgeons. Patients visited the gait laboratory two months after receiving TKA. Motion data was captured using a ten-camera motion capture system (Motion Analysis Corp., Santa Rosa, CA). Three-dimensional force data was recorded using four floor embedded force platforms (AMTI Inc., Watertown, MA). Patients were asked to walk at a self selected speed along a 6.5 metre walkway. A minimum of five good foot strikes for each limb were recorded. Data were collected using EVaRT 5 software (Motion Analysis Corp., Santa Rosa, CA) and analyzed using OrthoTrak 6.2.8 (Motion Analysis Corp., Santa Rosa, CA) and MatLab software (The Mathworks Inc., Natick, MA). Statistical analysis was performed using SPSS 14.0 software (SPSS Inc., Chicago, Il) (α = 0.05). Fifty-two patients (72 ± 6 years) volunteered to participate in the study. The approaches used were: standard parapatellar – 12; mini-parapatellar – 12; mini-midvastus – 14; mini-subvastus – 14. Statistical analysis found no significant differences in any of the variables measured except minimum knee flexion angle during stance (p=.046). The variables measured included the maximum and minimum injured lower limb joint angles in all planes during both stance and swing phase of gait. Also measured were the maximum joint moments in all planes during stance and hip, knee, and ankle powers. Patients who received TKA using the mini-subvastus approach had greater knee extension through much of the single stance phase of the gait cycle which contributed to a lower (but not significant) peak knee flexion moment. These patients also had the highest ground reaction shear forces with higher ankle power absorption at foot strike and generation at push off. Mini-subvastus patients used a higher cadence to walk with a greater velocity then patients who received surgery using the other approaches. The results of this study show only minor differences in gait between patients who have received surgery using the different approaches. The limited numbers of patients in the study and the large variation in outcomes so soon after surgery mean that in most cases the differences that were measured do not reach significant level. This study shows that the surgical approach used to implant the device has no apparent effect on the ability of the person to ambulate following surgery, however further study with increased numbers of patients and observation over a longer period of time will allow a stronger conclusion. The knowledge gained from this and future studies will enable surgeons to make decisions on type of approach based on factors other than expectations of functional outcome

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)