Introduction/Aim. Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non- weight bearing plaster versus functional weight bearing mobilisation. Methodology. The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients' demographics, treatment modality (non- weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non- weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism. Results. Out of the 47 patients who were treated conservatively in a non-weight bearing plaster cast, 9 patients (19.1 %) had a thromboembolic event. Out of the 41 patients who were treated with functional weight bearing mobilisation, 2 patients (4.8%) had a thromboembolic event. Thus, patients who were treated in a non-weight bearing plaster had a significantly higher risk of developing thromboembolism (p value of <0.05) and an increased risk ratio of 24% compared to those who were treated with functional weight bearing mobilisation. Conclusion. There is a significant decrease in the clinical incidence of thromboembolic events in patients treated conservatively with early mobilisation in the functional weight bearing boot compared to those treated in a non- weight bearing cast

Introduction/Aim. Thromboembolism is a significant cause of patient morbidity and mortality, the risk of which increases in orthopaedic patients with lower limb immobilisation. It was therefore, our aim to identify a difference in symptomatic thromboembolism by treating acute Achilles tendon rupture patients with conventional non-weight bearing plaster versus functional weight bearing mobilisation. Methodology. The notes of 91 consecutive patients with acute Achilles tendon rupture were reviewed. The patients demographics, treatment modality (non-weight bearing plaster versus weight bearing boot), and predisposing risk factors were analysed. From the 91 patients, 50 patients with acute Achilles tendon rupture were treated conservatively in a non-weight bearing immobilisation cast. From these 50 patients, 3 then underwent surgery and were therefore excluded from the results. 41 patients were treated with functional weight bearing mobilisation. Patients who did have a symptomatic thromboembolic event had an ultrasound scan to confirm a deep vein thrombosis of the lower limb, or a CT-scan to confirm pulmonary embolism. Results. Out of the 47 patients who were treated conservatively in a non-weight bearing plaster cast, 9 patients (19.1 %) had a thromboembolic event. Out of the 41 patients who were treated with functional weight bearing mobilisation, 2 patients (4.8%) had a thromboembolic event. Thus, patients who were treated in a non-weight bearing plaster had a significantly higher risk of developing thromboembolism (p value of <0.05) and an increased risk ratio of 24% compared to those who were treated with functional weight bearing mobilisation. Conclusion. There is a significant decrease in the clinical incidence of thromboembolic events in patients treated conservatively with early mobilisation in the functional weight bearing boot compared to those treated in a non-weight bearing cast

Introduction: Recently there has been a trend for recommending weight bearing 30û ßexion views as the standard view in place of full extension view for the routine radiography of the Knee. It has been shown that this view can pick up more abnormalities and can show a joint space diminution, which cannot be seen on full extension views. It has not been shown by any study that this is not due to the differential thickness of cartilage in different places on femoral condyle thus implying a natural cause rather than pathological process (abnormal wearing of cartilage) of the observed decrease in joint space. So this prospective randomised double blind study was designed. Methods: 22 patients with arthroscopically proven non osteoarthritic knees were included in the study. Knee radiographs were taken in weight bearing full extension and 30û ßexion PA views. The radiographs were randomised and read by a consultant, registrar & senior house ofþcer. Results: Appropriate statistical tests were applied and results analysed. There was up to 2mm difference in the joint space on the two views. Conclusion: The decrease in the joint space if seen on 30û ßexion views as compared to full extension views may be due to the differential thickness of inherent normal cartilage and so is not always due to a pathological process. Based on this a classiþcation was devised to signify the importance of measured differential thickness in the cartilage of femoral condyle

Aim: To ascertain the accuracy of partial weight bearing. Method: 6 healthy volunteers with a below knee plaster cast, 10 patients with uncemented hip replacements and 12 patients with lower limb fractures were trained to partial weight bear. They were asked to place the affected leg on a bathroom scale and to press on it till the prescribed limit. This process was repeated till the subject formed a mental image of the amount of load they must put through the limb. The ability to partial weight bear was tested in a gait lab by making them walk on a walkway incorporating a Bertec force platform. Exact magnitude of weight bearing was calculated from the vertical ground reaction forces produced. Results: 4 out of 6 volunteers exerted mean weight of 20.3 kg above and the remaining 2 exerted 5.6 kg below that prescribed. Of the 22 patients, 19 exerted mean weight of 24.3 kg above and 3 patients exerted mean weight of 7.5 kg below that prescribed. As per Spearmanñs rank correlation test, the relationship between the prescribed weight bearing and the actual weight bearing was non-signiþcant (p=0.399) i.e., there is little relationship between the prescribed and actual weight bearing. Conclusions: Neither patients nor healthy volunteers could partial weight bear to the extent required. They were either above or below the prescribed level of partial weight bearing. Current method of teaching partial weight bearing is inaccurate and has poor reproducibility. Such methods use static loading situations whereas walking is a dynamic activity. An inexpensive, easy to use, dynamic device is required to train patients to partial weight bear

Introduction: Each year millions of people are treated for hip, knee or foot surgery which require rehabilitation programs that typically involve limited or controlled weight bearing on an affected limb. Weight bearing reduces edema & facilitate rapid rehabilitation. Current weight-bearing instruction protocols involve non-quantitative guidelines, based on the patient’s amount of discomfort while walking or subjective perception. However, the interpretation of these instructions is inaccurate and subjective, and varies among clinicians and patients. New biofeedback technology concepts are beginning to be implemented in the rehabilitation process. The Smart-Step system is a new weight bearing monitoring system that assists clinicians and physical therapists to accurately assess, train and monitor patients’ weight bearing capabilities. Purpose: To assess the effectiveness of the SmartStep system in guiding weight bearing restrictions, and to assess the effectiveness of the SmartStep system as a tool to reeducate full weight bearing. Material and Methods: 8 Patients in the Orthopedic rehabilitation department & 5 patients in the orthopedic physiotherapy out-patient clinic, post orthopedic surgery with FWB instructions were randomly divided into Study & Control groups. During treatment, the patients were trained by the PT in FWB according to the instruction of the surgeon. Data of age and body weight was collected from all patients. Patients in both study groups used the SmartStep System. This system consists of an in-shoe inflatable insole, pressure sensors and a control unit for data storage. The control unit provides also an audio signal whenever the patient was bearing body weight at a recommended and pre-calibrated level. Results: The mean age and body weight were 62±12 years and 76±15 kg in the study group and 65±15 years and 70±13 kg in the control group. Data obtained in both groups (in kg) during the pre-test and during the gait tests was converted into percentage of the patients BW. The means of the differences between the pre-test results and the gait test results in both groups were 9 + 6.7% and 1.5 + 6% in the study and control group, respectably (p=0.0002). Conclusions: The new Smartstep system was proved to be a useful tool in assisting gait rehabilitation since its biofeedback system enhances and improves weight bearing over the affected limb in cases where FWB is recommended

Background. There exists no consensus opinion as to the most suitable post-operative rehabilitation and weight bearing status for proximal tibia articular fractures treated with internal fixation using plates and screws. Objectives. The aim of this study is to investigate whether the post-operative weight bearing status is associated with loss of reduction and articular collapse. Study Design and Methods. Data was retrospectively analysed from our prospective database in a major trauma centre. Group I were non-weight bearing for the first six weeks post-operation and Group II were instructed to weight bear fully immediately post-operation. Radiographs were taken day one post-operation, at six weeks and at three months and analysed for fracture displacement and joint depression or loss of fixation. Results. 90 patients were included in the study. The follow up radiographs demonstrated no failure of fixation in either study group. One patient from the weight bearing group had >1mm joint depression (4mm) identified at the first follow up, which did not worsen by the second. Conclusions. This study shows immediate post-operative full weight bearing does not affect the fixation or cause articular collapse up to three months after surgery. We propose that patients should be encouraged to weight bear immediately post-operation

Non-union is a potential complication following hindfoot arthrodesis and occurs at a rate of 5–10% as reported in the literature. Following the procedure, patients are usually kept non-weight bearing (NWB) for 6–8 weeks followed by protected full weight bearing (FWB) for further 6 weeks. Based on radiological and clinical evidence of bony union at 12 weeks patients are allowed to mobilise FWB without protection. The aim of this study is to evaluate the effect of early post operative weight bearing on the union rate, following hindfoot arthrodesis. In this retrospective study data was collected on patients who had hindfoot arthrodesis from 2003 to 2008 by a single surgeon. Two post operative mobilisation protocols were used and the union rates were compared. Protocol 1: 6 weeks Non weight bearing (NWB), 3 weeks partial weight bearing (PWB), 3 weeks full weight bearing (FWB) in plaster. Protocol 2: 2 weeks NWB, 4 weeks PWB, 6 weeks FWB in plaster. One hundred and twenty-nine hindfoot joint arthrodesis were performed in 73 patients. Non-union rate was 1% (1 in 95 joints) in early weight bearing group and 20% (7 in 34 joints) in late weight bearing group. Union rate following the revision surgery with bone graft was 100% in both groups. Early weight bearing following hindfoot arthodesis is safe, provides a more comfortable mobilisation for the patient and has no adverse effect on the union rate

Introduction: Non-union is a potential complication following hindfoot arthrodesis and occurs at a rate of 5–10% as reported in the literature. Following the procedure, patients are usually kept non-weight bearing (NWB) for 6–8 weeks followed by protected full weight bearing (FWB) for further 6 weeks. Based on radiological and clinical evidence of bony union at 12 weeks patients are allowed to mobilise FWB without protection. Aim: The aim of this study is to evaluate the effect of early post operative weight bearing on the union rate, following hindfoot arthrodesis. Method: In this retrospective study data was collected on patients who had hindfoot arthrodesis from 2003 to 2008 by a single surgeon. Two post operative mobilisation protocols were used and the union rates were compared. Protocol 1: 6 weeks NWB, 3 weeks partial weight bearing (PWB), 3 weeks FWB in plaster. Protocol 2: 2 weeks NWB, 4 weeks PWB, 6 weeks FWB in plaster. Results: 128 hindfoot joint arthrodesis were performed in 73 patients. Non-union rate was 2%(1 in 44) in early weight bearing group and 20% (4 in 16) in late weight bearing group. Union rate following the revision surgery with bone graft was 100% in both groups. Conclusion: The union rate following hindfoot surgery significantly improves (p=0.01) with early post-operative weight bearing

Patients with osteoarthritis of the knee reviewed by the General practioners, are usually referred for further management to the orthopaedic surgeon. It was our observation that patients were usually referred with supine knee X-rays. This meant weight-bearing films were repeated at the clinic. Methods: We sent out questionnaires to GPs inquiring whether they asked for X-rays of the knee prior to patient referral and whether they asked for weight bearing films. We also reviewed the policy in one National Hospital Service trust and one teaching hospital with regards to GPs asking for weight bearing films. The time patients spent waiting at the X-rays department was noted. Finally we inquired about the cost of a knee X-ray. Results: A total number of 65 questionnaires were sent and the response was 44 i.e. 67%. 80% of the GPs asked for non weight bearing X-rays prior to referral. Only 5% asked for weight bearing films. The radiology departments of hospitals in one NHS trust and the teaching hospital did not accept weight bearing requests from GPs. The time taken for a patient to get an X ray in the department was at least 30 minutes and the cost of X rays of the knee was £51. With an average of two patients with osteoarthritis of the knee per clinic, the cumulative waiting time for repeated X-rays was 1 hr per clinic, 5 hrs per week and 240 hrs per year. With an average of two X rays per clinic the cumulative cost was £102 per clinic, £510 per week and £24480 per year. Discussion: Non weight bearing X-rays of the knee do not add any value in making or confirming a diagnosis of osteoarthritis yet they are costly both in terms of time and money. Weight bearing films were repeated for patients with these X-rays. The cumulative cost in terms of time can be better used to review other patients and therefore reduce the waiting time before surgeons can see referrals. The other issue is the cumulative cost which can be put to better use in the trust. The time wasted by the patients who have repeated X-rays was not considered, but is also of importance. Conclusion: Patients with osteoarthritis of the knee should have weight bearing films from the initial onset. This will save time for the patient and the surgeon and will save the hospital money

Introduction. Plate fixation for distal femoral fractures is a commonly used method of fracture stabilisation. Many orthopaedic surgeons traditionally do not allow their patients to weight bear for the first 6 weeks after surgery, fearing of loss of fracture reduction and metalwork failure. The aim of this study is to investigate whether the post-operative weight bearing status after plate fixation influences the outcome in terms of loss of reduction and metalwork failure. Materials & Methods. A retrospective data collection from all patients who treated in our hospital surgically for distal femoral fractures, from January 2015 until June 2017. Inclusion criteria were the operative treatment of these fractures with plate fixation. Patients who were treated with retrograde nail, primary total knee replacement or screw fixation were excluded from the study. Patient, injury and surgery demographic data was collected. The immediate post-operative weight bearing status of these patients was noted. Weight bearing status was divided into two groups – Group 1 (Non and touch weight bear – the non-weight bearing group) and Group 2 (Weight bear as tolerated / Full weight bear – the weight bearing group). Radiological data about fracture displacement or metalwork failure was collected at the six weeks and three months follow up after the operation, using a standardised measurement for displacement performed independently by two authors (EI, TA). Results. Of 70 patients, a total of 51 fractures treated with plate fixation were included to the study. The mean age of the cohort was 64.3 ±20.7 years with the majority of the patients being female (63%). Most of the patients (40%) had a complete articular distal femoral fracture, AO Type 33C. Thirty-nine patients (76%) were treated with one lateral distal femoral plate. The total number of the patients in group 1 was 32 (68%); with 17 patients (32%) in group 2. The weight bearing status did not correlate with the fracture type or the fixation type (p>0.05). None of the 6 weeks follow up radiographs revealed fracture displacement in both study groups. Four of the patients from the non-weight bearing group had >1mm displacement at the 3 months' follow-up radiographs. Fisher's exact test revealed no statistically significant difference between the two study groups in both follow-up time points (p=0.55). Two of the patients in the non-weight bearing group had their plate broken at the 3 months follow up and required revision fixation. Conclusion. By reviewing the outcomes in terms of fracture displacement and metalwork failure following plate fixation of distal femoral fractures, early weight bearing of these patients do not jeopardise the outcome of the operation

Tibial fractures represent a heterogeneous group of fractures that are difficult to treat and vary widely in their time to union. Judging when it is safe to remove an external fixator or plaster cast requires clinical and radiological assessments both of which are subjective. Any errors in determining when a fracture has healed can lead to a prolonged treatment time or to refracture. Many methods have been employed to attempt to define clinical union in an objective manner including ultrasound, DEXA scanning, vibration analysis, and fracture stiffness measurements. Stiffness measurements are however time consuming to perform, of debatable clinical significance, and applicable only to fractures treated with external fixators. It has been previously observed. 1,. 2. that weight bearing increases with time post-fracture. It has also been suggested. 3. that the ability of a patient to weight bear on the fractured limb is controlled by a biofeedback mechanism of biological self-control of fracture site strain that will be related to the stiffness of the fracture. We hypothesised that weight-bearing will be closely related to fracture healing and could be used as an alternative measure of healing where other objective measures of healing are not available or are impracticable. A group of ten patients with tibial fractures treated by external fixation were studied. Using a Kistler force plate set into the floor, ground reaction forces for both lower limbs (fractured and non-fractured) were measured during normal walking at three weekly intervals. Concurrent fracture stiffness measurements were made using the Orthofix Orthometer. In 8 patients who made good recoveries, the fixator was removed between 15–20 weeks post injury when the fracture stiffness had reached a minimum of 15 Nm/deg. Weight-bearing through the injured leg was seen to approach 90% of that through the uninjured leg in the 3 weeks prior to fixator removal. Two patients with delayed union achieved weight bearing of less than 40% of normal between 15–20 weeks. They also demonstrated low values of fracture stiffness (< 5 Nm/deg.) and subsequently required operative intervention to achieve union. In this small study of 10 patients, weight bearing appears to correlate well with clinical union. It is quicker and easier to assess than stiffness and potentially has relevance to other fixation methods. We are continuing these measurements on conservatively treated, intra-medullary nailed, and externally fixed tibial fractures

Acute achilles tendon ruptures are increasing in incidence and occur in 18 per 100 000 people per year, however there remains a lack of consensus on the best treatment of acute ruptures. Randomised studies comparing operative versus non-operative treatment show operative treatment to have a significantly lower re-rupture rate, but these studies have generally used non-weight bearing casts in the non-operative group. Recent series utilizing more aggressive non-operative protocols with early weight-bearing have noted a far lower incidence of re-rupture, with rates approaching those of operative management. Weight bearing casts may also have the advantages of convenience and an earlier return to work, and the purpose of this study was to compare outcomes of traditional casts versus Bohler-iron equipped weight-bearing casts in the treatment of acute Achilles tendon ruptures. 83 patients with acute Achilles tendon ruptures were recruited from three Auckland centres over a 2 year period. Patients were randomised within one week of injury to receive either a weight-bearing cast with a Bohler iron or a traditional non weight-bearing cast. A set treatment protocol was used, with a total cast time of eight weeks. Patients underwent detailed muscle dynamometry testing at 6 months, with further follow up at 1 year and at study completion. Primary outcomes assessed were patient satisfaction, time to return to work, and overall re-rupture rates. Secondary outcomes included return to sports, ankle pain and stiffness, footwear restrictions, and patient satisfaction. There were no significant differences in patient demographics or activity levels prior to treatment. At follow up, 1 patient (2%) in the Bohler iron group and 2 patients (5%) in the non weight bearing group sustained re-ruptures (p=0.62). There was a trend toward an earlier return to work in the weight-bearing group, with 58% versus 43% returning to work within 4 weeks, but the difference was not significant. 63% of patients in the weight bearing group reported freedom from pain at 12 months compared to 51 % in the non weight bearing group. There were no statistically significant differences in Leppilahti scores, patient satisfaction, or return to sports between groups. Weight-bearing casts in the non-operative treatment of Achilles tendon ruptures appear to offer outcomes that are at least equivalent to outcomes of non-weight bearing casts. The overall rerupture rate in this study is low, supporting the continued use of initial non-operative management in the treatment of acute ruptures

The relative motion between a prosthesis, the cement mantle and its’ host bone during weight bearing is not well understood. Using Radiostereophotogrammetric Analysis (RSA), we examined the dynamically inducible micromotion that exists at these interfaces when an increased load is placed through the prosthesis. Dynamically inducible micromotion was measured in the femoral components of 21 subjects undergoing total hip replacement with polished Exeter stems. Two standing RSA studies were performed, at 3 and 12 months postoperatively. Firstly in double-leg stance, and secondly fully weight bearing through the operated hip. Subjects had no signs of clinical or radiological signs of loosening at 1 year. Significant micromotion was detected at the prosthesis-cement interface at 3 months. Similar patterns of micromotion were observed at 12 months. The prosthesis appeared to bend during single-leg stance weight bearing, however this accounted for less than half of the total observed movement. Conventional RSA studies were conducted at 3 months, 6 months and 1 year to confirm that the implants showed normal migration patterns. This study demonstrates that movement exists between the prosthesis and bone during cyclical weight bearing. This dynamically inducible micromotion probably occurs at the prosthesis-cement interface. It could account for the wear that is observed on the surface of retrieved secure prostheses. This may be a mechanism by which failure eventually occurs

Severe bone loss in weight bearing bones is one of the main causes for morbidity in trauma victims. The use of guided bone regeneration in the treatment of such large defects has not yet been studied extensively. The aim of this study was to establish an accurate evaluation system, which will enable quantifying the compatibility of membranes to provide bone regeneration in a large middiaphyseal bone defect. In our longitudinal study on 16 rabbits we examined the new bone formation obtained in the vicinity of critical segmental defects (2.5 times the diameter of the bone) covered with tubular ethyl cellulose membranes. The contralateral limbs with the same bone defect served as the control group which was not treated by membranes. The healing process was followed up for eight weeks. Bone analysis of the implanted and non-implanted bone defects and adjacent tissues was performed in order to evaluate the total area and the density of the regenerated new bone at the gap area. Computerized X-ray study showed newly formed bone as early as 14 days after membrane implantation within and around the radial defect compared with a typical creation of non-union in the contra-lateral non-implanted defects. The bone formation across the gap progressed until reconstruction of the defect occurred after 6–8 weeks. A slowdown in new bone formation was evident after 6 weeks according to the measurements of area size and density of the formed bone. A parallel longitudinal histomorphological assessment of the process in the treated and non-treated bone defects was conducted. A characteristic process of osteogenic activity and new bone formation takes place inside the confined space and within the tissues around it. A typical modeling process with lytic changes in the different osteogenic fronts takes place from the second week post-implantation. These histological findings, corresponding with the radiological assessment, were summarized according to a scoring system which was constructed by the authors. The scoring was related to eight different zones which were defined within and around the osteotomy site. This rabbit model clarifies the mechanism and provides quantification of guided bone regeneration. It can serve as a means to study the accelerated bone formation using different membranes in large segmental weight bearing bone defects

Introduction: Non-union occurs at a rate of 5–10 % following ankle and hindfoot arthrodesis, but the effect of early weight bearing on union rate in these patients has not been studied. Materials and Method: We have looked at the union rate following ankle and hindfoot arthrodesis with an early weight bearing protocol in a single surgeon series between 2003 and 2008. Data was collected retrospectively on 108 patients with a total of 198 ankle and hindfoot joint arthrodesis. Results: The non-union rate was 3.4% (9 in 154 joints) in the early weight bearing group and 18% (8 in 44 joints) in the late weight-bearing group. Union rate following revision surgery with bone graft was 100% in both groups. Discussion: Early weight bearing following ankle and hind-foot arthrodesis has no adverse effect on the union rate

Stable Weber B fractures are typically treated non-operatively without complications but require close monitoring due to concerns over potential medial deltoid ligament injuries and the risk of delayed talar shift. Following recent evidence suggesting this is unlikely, a functional protocol with early weight bearing was introduced at Glasgow Royal Infirmary (GRI) following a pilot audit. This study aims to evaluate the risk of delayed talar shift in isolated Weber B fractures managed with functional bracing and early weight-bearing, particularly if signs of medial ligament injury are present. We conducted a retrospective review of 148 patients with isolated Weber B fractures without talar shift at presentation that were reviewed at the virtual fracture clinic at our institution between July 2019 and June 2020. The primary outcome was the incidence of delayed talar shift. Secondary outcomes were other complications and adherence to protocol. 48 patients had medial signs present and of these 1 (2%) showed possible talar shift on X-rays at 4 weeks, and was kept under review. This patient had a normal medial clear space at 3 months. No patients with medial signs not documented (n=19) or not present (n=81) had delayed talar shift. 10% of patients (n=15) had at least 1 complication: delayed union (n=2); non-union (n=3); ongoing pain (n=14). Functional bracing with early weight-bearing is a safe, effective protocol for managing isolated Weber B fractures without initial talar shift. This study concludes that the risk of delayed talar shift is low in all patients, with or without medial signs

Introduction. Electromyography (EMG) is the best known method in obtaining in vivo muscle activation signals during dynamic activities, and this study focuses on comparing the EMG signals of the quadriceps muscles for different TKA designs and normal knees during maximum weight bearing flexion. It is hypothesized that the activation levels will be higher for the TKA groups than the normal group. Methods. Twenty-five subjects were involved in the study with 11 having a normal knee, five a rotating platform (RP) posterior stabilized (PS) TKA, and nine subjects with a PFC TC3 revision TKA. EMG signals were obtained from the rectus femoris, vastus medialis, and vastus lateralis as the patients performed a deep knee bend from full extension to maximum flexion. The data was synchronized with the activity so that the EMG data could be set in flexion-space and compared across the groups. EMG signals were pre-processed by converting the raw signals into neural excitations and normalizing this data with the maximum voluntary contraction (MVC) performed by the subject. The signals were then processed to find the muscle activations which, normalized by MVC, range from 0 to 1. Results. The average muscle activations for each of the three groups are shown in Figures 1, 2, and 3 for the rectus femoris, vastus medialis, and vastus lateralis respectively. The vastus medialis had the highest activation of the muscles during the weight bearing activity from 0 to 90 degrees flexion. On average, the trend seen is that the normal group had lower muscle activation levels to perform the weight bearing activity as opposed to the TKA groups which supports our hypothesis. The PS RP TKA had lower peak values than the PFC TC3 TKA. Discussion. EMG analysis provides insight into muscle activation during dynamic activities. When designing TKA devices for implantation, the patient themselves must be taken into account. In a subject with deficient ligaments, a more constrained device can make day-to-day activities easier, but at the expense of extra effort in achieving higher flexion activities. The high constraints within the PFC TC3 may cause the patient to have to put more effort into the activity. The rotating platform TKA had closer to normal muscle activation levels for the maximum weight bearing knee flexion activity

The patella is a complex sesamoid bone within the quadriceps enhancing mechanical advantage of the extensor mechanism. Depending on activity, the patella magnifies either force or displacement; behaving as a lever, by redirecting quadriceps force it also acts as a pulley. Aim. We describe and validate a device for obtaining consistent dynamic weight bearing views of the patellofemoral joint (PFJ). Materials and Methods. Weight bearing (WB) axial views of 48 knees (24 patients) were performed using the device. The sulcus angle (SA), congruence angle (CA), lateral patellofemoral angle (LPFA), facet angle (FA) and patellofemoral displacement (PD) were measured. These were compared with similar measurements made on prone (PR) and axial (AX) radiographs of same knees. Results. Variance (V=SD2) and Standard error of mean (SEM/95% CI) for all measurements in each of the three views were analysed. For the Sulcus Angle, Congruence angle and LPFA, the WB view had the lowest SEM and the least variance in comparison to PR and AX views (SEM 1.05/V 30.14, SEM 2.52/V 172.39 and SEM 1.34/V 47.61 respectively for the SA, SEM 3.09/V 256, SEM 2.79/V 210.25 and SEM 3.37/V 306.25 respectively for the CA, SEM 0.67/V 11.9, SEM 1.20/V39.06 and SEM 1.03/V 28.83 respectively for the LPFA). SEM and Variance for FA measurements were similar for WB and AX views but superior to PR views (SEM 1.62/V 70.56, SEM 1.6/V 68.9 and SEM 2.3/V 148.84 respectively). Mean PFD was maximum on the WB view compared to the PR and AX views (36.0, −45.62 and 22.23 respectively) with lowest SEM and V (SEM 8.73/V 2052.0, SEM 18.65/V 92959.67 and SEM 9.70/V 2540.16 respectively). Conclusion. The WB view as introduced and reported here has consistently lower Variance, SEM and SD in comparison to Axial and Prone views for all measurements of the PFJ. WB view also gives a more accurate dynamic measure of Patello Femoral displacement. The view is easily obtained and readily reproduced

Purpose: We wanted to ascertain whether the advantages of functional treatment on trophicity could be combined with the advantages of surgical treatment on anatomic results in patients with displaced calcaneal join fractures. Material and methods: Using the AO 3.5 reconstruction plates with specific stereotypic modelling we were able to obtain solid fixation in almost all cases of calcaneal joint fractures using a rigorous technique and following precise principles, notably the direction of the screw into the sustentaculum tali.As the osteosynthesis is very stable, we postulate that partial and progressive early weight bearing would be acceptable as long as pain was under a threshold level used as sign of micromobility. The first cases were very favourable so we extended this method, using it as a routine procedure for all cases (excepting those with an associated injury excluding weight bearing). Among 122 fractures operated with this method, 118 were reviewed. Results: According to the Duparc classification, we treated one type 2, 34 type 3, 76 type 4 and seven type 5 fractures. Weight bearing was initiated on the average at 14 days, with a median of seven days. The Boehler angle improved from 0° preoperatively to 22° postoperatively. We did not have any cases of secondary displacement greater than 2°. The functional outcome was, according to the SOFCOT criteria: very good 34.5%, good 41.4%, fair 9.5% and poor 0%. Physical results (SOFCOT criteria) were: very good 17.2%, good 54.3%, fair 26.7%, poor 1.7%. Anatomic results according to AFC criteria were: very good and good 69%, fair 25.9%, poor 5.1%. Discussion: These result demonstrate that a rigorous therapeutic management scheme can combine the advantages of functional and surgical treatment of displaced calcaneal joint fractures. Early weight-bearing below the pain threshold was effective since all our bilateral cases could be discharged after walking a few steps. Recovery was more rapid when weight bearing was late. Crutches could be abandoned at two months on the average. Conclusion: We believe that solid osteosynthesis is possible in almost all cases of displaced calcaneal fractures with joint involvement if a rigorous technique is used. Progressive early weight bearing below the pain threshold is a significant adjuvant factor favouring rapid and quality outcome

Background: Interventional MRI provides a novel non-invasive method of in-vivo weight-bearing analysis of the subtalar joint. Preceding in-vivo experimentation with stereophotogammetry of volunteers embedded with tantalum beads has produced valuable data on relative talo-calcaneal motion (Lundberg et al. 1989). However the independent motion of each bone remains unanswered. Materials and Methods: Six healthy males (mean 28.8 years), with no previous foot pathology, underwent static right foot weight bearing MRI imaging at 0°, 15° inversion, and 15° eversion. Using identifiable radiological markers the absolute and relative rotational and translational motion of the talus and calcaneum were analysed. Results and Discussion:Inversion: The calcaneum externally rotates, plantar-flexes and angulates into varus. The talus shows greater plantar-flexion with similar varus angulation, with variable axial rotation. Relative talo-calcaneal motion thus involves, 6° relative talar internal rotation, 3.2° flexion and no motion in the frontal plane. Concurrently the talus moves laterally on the calcaneum, by 6.5mm, with variable translations in other planes. This results in posterior facet gapping and riding up of the talus at its posterolateral prominence. Eversion: The calcaneum plantar-flexes, undergoes valgus angulation, and shows variable rotation in the axial plane. The talus plantar-flexes less, externally rotates, and shifts into varus. Relative motion in the axial plane reverses rotations seen during inversion (2.5° talar external rotation). The 8° of relative valgus talo-calcaneal angulation is achieved consistently through considerable varus angulation of the talus, in a direction opposite to the input motion. This phenomenon has not been previously reported. From coronal MRI data, comparative talo-calcaneal motion in inversion is prevented by high bony congruity, whereas during eversion, the taut posterior tibio-talar ligament prevents talar valgus angulation. Conclusion: We have demonstrated that Interventional MRI scanning is a valuable tool to analysing the weight bearing motion of the talo-calcaneal joint, whilst approaching the diagnostic accuracy of stereophoto-gammetry. We have also demonstrated consistent unexpected talar motion in the frontal plane. Talo-calcaneal motion is highly complex involving simultaneous rotation and translation, and hence calculations of instantaneous axes of rotation cannot effectively describe talo-calcaneal motion. We would suggest that relating individual and relative motion of the talus / calcaneum better describes subtalar kinematics