Aims. Accurate identification of the ankle joint centre is critical for estimating tibial coronal alignment in total knee arthroplasty (TKA). The purpose of the current study was to leverage artificial intelligence (AI) to determine the accuracy and effect of using different radiological anatomical landmarks to quantify mechanical alignment in relation to a traditionally defined radiological ankle centre. Methods. Patients with full-limb radiographs from the Osteoarthritis Initiative were included. A sub-cohort of 250 radiographs were annotated for landmarks relevant to knee alignment and used to train a deep learning (U-Net) workflow for angle calculation on the entire database. The radiological ankle centre was defined as the midpoint of the superior talus edge/tibial plafond. Knee alignment (hip-knee-ankle angle) was compared against 1) midpoint of the most prominent
Introduction: There is limited literature available looking into circumstances surrounding the development of stress fracture of the medial and lateral
Introduction: There is limited literature looking into the circumstances surrounding the development of stress fractures of the medial and lateral
Abstract. Introduction. Controversy exists regarding the optimal tibial coronal alignment in total knee arthroplasty. Many believe navigation or robotics are required to set kinematic alignments or to ensure they remain within ‘safe’ limits e.g. maximum 5° varus on the tibia. Given most navigation or robotic systems require the surgeon to identify the ankle
Treatment of posterior malleolar (PM) ankle fractures remain controversial. Despite increasing recommendation for small PM fragment fixation, high quality evidence demonstrating improved clinical outcomes over the unfixated PM is limited. We describe the medium-to-long term clinical and radiographical outcomes in younger adult patients with PM ankle fractures managed without PM fragment fixation. A retrospective cohort study of patients aged 18–55 years old admitted under our orthopaedic unit between 1st of April 2009 and 31st of October 2013 with PM ankle fractures was performed. Inclusion criteria were that all patients must mobilise independently pre-trauma, have no pre-existing ankle pathologies, and had satisfactory bimalleolar and syndesmotic stabilisation. Open fractures, talar fractures, calcaneal fractures, pilon fractures, subsequent re-injury and major complications were excluded. All PM fragments were unfixated. Clinical outcomes were evaluated using Foot and Ankle Ability Measure (FAAM) with activities of daily living (ADL) and sports subscale, visual analogue scale (VAS) and patient satisfaction ratings. Osteoarthrosis was assessed using modified Kellgren-Lawrence scale on updated weightbearing ankle radiographs. 61 participants were included. Mean follow-up was 10.26 years. Average PM size was 16.19±7.39%. All participants were evaluated for clinical outcomes, demonstrating good functional outcomes (FAAM-ADL 95.48±7.13; FAAM-Sports 86.39±15.52) and patient satisfaction (86.16±14.42%), with minimal pain (VAS 1.13±1.65). Radiographical outcomes were evaluated in 52 participants, showing no-to-minimal osteoarthrosis in 36/52 (69.23%), mild osteoarthrosis in 14/52 (26.92%) and moderate osteoarthrosis in 2/52 (3.85%). Clinical outcomes were not associated with PM fragment size, post-reduction step-off, dislocation,
There is limited literature available looking into circumstances surrounding the development of stress fracture of the medial and lateral
Introduction: There is limited literature available looking into circumstances surrounding the development of stress fracture of the medial and lateral
Introduction. The position and orientation of the lower extremities are fundamental for planning and follow-up imaging after arthroplasty and lower extremity osteotomy. But no studies have reported the reproducibility of measurements over time in the same patient, and experience shows variability of the results depending on the protocols for patient positioning. This study explores the reproducibility of measurements in the lower extremity with the patients in “comfortable standing position” by the EOS® imaging system. Materials and Methods. Two whole-body acquisitions were performed in each of 40 patients who were evaluated for a spine pathology. The average interval between acquisitions was 15 months (4–35 months). Patients did not have severe spine pathology and did not undergo any surgery between acquisitions. The “comfortable standing position” is achieved without imposing on the patient any specific position of the lower limbs and pelvis. All the measurements were performed and compared in both 2- and 3-dimensional images. Distances between the centers of the femoral heads and between the centers of the knees and ankles were measured from the front. The profile is shown by the flexion angle between the axis of the femur (center of the femoral head and the top of the line Blumensaat) and the axis of the tibia. Results. The average radiation dose was 0.80 mGy (0.5–1.11). For the first acquisition, the mean distance between the femoral heads was 17.9 cm (15.8–20.2), the mean distance between the middle of the knee joints was 16.7 cm (11.2–23.1) and the mean distance between the medial
Background Computer navigation is increasingly being recognized as a valuable tool in restoring the mechanical axis post TKR. Its use is as yet not universal due to the costs involved, its availability and the fact that it can be cumbersome and time consuming to use. Additionally it requires the insertion of Schanz pins in the femur as well as the tibia which can be a matter of concern as regards stress fracture and infection. However, it is able to reliably locate the center of the femoral head which is an elusive landmark in the standard method. The center of the ankle involves registration for the medial and lateral
Ankle fracture fixation is commonly performed by junior trainees. Simulation training using cadavers may shorten the learning curve and result in a technically superior surgical performance. We undertook a preliminary, pragmatic, single-blinded, multicentre, randomized controlled trial of cadaveric simulation versus standard training. Primary outcome was fracture reduction on postoperative radiographs.Aims
Methods
Incorrect registration during computer assisted total knee arthroplasty (CA-TKA) leads to malposition of implants. Our aim was to evaluate the tolerable error in anatomic landmark registration. We incorrectly registered the femoral epicondyles, femoral and tibial centers, as well as the
Traditional screw fixation of the syndesmosis can be prone to malreduction. Suture button fixation however, has recently shown potential in securing the fibula back into the incisura even with intentional malreduction. Yet, if there is sufficient motion to aid reduction, the question arises of whether or not this construct is stable enough to maintain reduction under loaded conditions. To date, there have been no studies assessing the optimal biomechanical tension of these constructs. The purpose of this study was to assess optimal tensioning of suture button fixation and its ability to maintain reduction under loaded conditions using a novel stress CT model. Ten cadaveric lower limbs disarticulated at the knee were used. The limbs were placed in a modified external fixator frame that allows for the application of sustained torsional (5 Nm), axial (500 N) and combined torsional/axial (5Nm/500N) loads. Baseline CT scans of the intact ankle under unloaded and loaded conditions were obtaining. The syndesmosis and the deltoid ligament complex were then sectioned. The limbs were then randomised to receive a suture button construct tightened at 4 kg force (loose), 8 kg (standard), or 12 kg (maximal) of tension and CT scans under loaded and unloaded conditions were again obtained. Eight previously described measurements were taken from axial slices 10 mm above the tibiotalar joint to assess the joint morphology under the intact and repair states, and the three loading conditions: a measure of posterolateral translation (a, b), medial/lateral translation (c, g), a measure of anterior-posterior translation (f), a ratio of anterior-posterior translation (d/e), an angle (Angle 1) created by a line parallel to the incisura and the axis of the fibula, and an angle (Angle 2) created between the medial surfaces of two
We present a simple seated dial test that can be used by a single examiner in the acute or chronic situation to diagnose posterolateral corner knee injury. In the acute setting a traditional prone dial test can be cumbersome and painful for patients. Therefore a supine technique can be utilised, however this requires an assistant in order to hold the knees together with the tibia in a reduced position. We therefore utilise a seated technique in which the patient sits with their knees flexed over the edge of the examination couch. The patient is then able to hold their knees together, negating the need for an assistant. The sensitivity of a dial test is improved if the knee is reduced and so with this technique the tibia will be held in the anatomical position by the examination couch. The patients' feet are grasped with both medial
We present a series of 16 patients who have had a failed ankle arthroplasty converted to an ankle arthrodesis using a surgical technique of bone grafting with internal fixation. We describe our technique using tricortical autograft from the iliac crest to preserve length and an emphasis is placed on maintaining the
Introduction. Evaluation of post-operative soft tissue balancing outcomes after Total Knee Arthroplasty (TKA) and other procedures can be measured by stability tests, with Anterior-Posterior (AP) drawer tests and Varus-Valgus (VV) ligamentous laxity tests being particularly important. AP stability can be quantified using a KT1000 device; however there is no standard way of measuring VV stability. The VV test relies on subjective force application and perception of laxity. Therefore we sought to develop and validate a device and method for quantifying knee balancing by analyzing VV stability. Materials and Methods. Our team developed a Smart Knee Fixture to measure VV angular changes using two dielectric elastomer stretch sensors, placed strategically over the medial and lateral collateral ligaments (see Figure 1). The brace is secured in position with the leg in full extension and the sensors locked with pre-tension. Therefore, contraction and elongation of either sensor is measured and the VV angular deviation of the long axis of the femur relative to that of the tibia is derived and displayed in real time using custom software. EMG muscle activity was previously investigated to confirm there is no resistive activity during the VV test obstructing ligamentous evaluations. The device was validated in two ways:. A bilateral lower body cadaver specimen, secured in a custom test rig, was used to compare the Smart Knee Fixture's readings to those measured from an optical surgical navigation system. Abduction and adduction force was gradually applied as varus and valgus moments with a wireless hand-held dynamometer up to 50N (19.8Nm) at 0 and 15° flexion. Two male volunteers were used to compare the Smart Knee Fixture's readings to those measured from fluoroscopic images. An arthroscopic distal thigh leg immobilizer was used to prevent rotation and lateral movements of the thigh when moments were applied at the
Soft tissue balancing in total knee replacement may well be the determining factor in raising the fair patient satisfaction. The development of intelligent implants allows quantification of reactive loads to applied pressures. This can be tested in dynamic mode such as heel push test at surgery, or in static mode such as when testing for varus/valgus (VV) laxity of the collateral ligaments of the knee. We postulate that a well-balanced knee will have comparable if not equal load distribution across compartments in dynamic loading. When tested for laxity, we anticipate an equal or comparable response to VV applied loads under physiologic load range of 10–50N. This study sought to analyze the relationship between the kinematic (joint motion) and kinetic (force) effects to VV testing in the 0–15 degrees range of flexion. One goal was to demonstrate that testing the knee in locked extension (Screw Home effect) is unreliable and should be abandoned in favor of the more reliable VV testing at 10–15 degrees of flexion. This is a preliminary cadaveric study utilizing data from two hemibodies. The pelvis was fixed in a custom test rig with open or closed chain lower leg testing capability along a sliding rail with foot VV translational. Forces were applied at the
We reviewed the outcome of Agility total ankle replacements carried out in our institution between 2002 and 2006. Follow-up consisted of clinical and radiological review pre-operatively, at 6 weeks, 6 and 12 months, and annually until 10 years post-op. Clinical review included the American Orthopaedic Foot and Ankle Score, satisfaction and pain scores. 30 arthroplasties were performed in 30 consecutive patients. Pre-operative diagnosis was rheumatoid arthritis (16), primary osteoarthritis (12) and post-traumatic osteoarthritis (2). After a mean follow up of 6.2 years (1.4–10.1), 4 patients had died, and 20 out of the remaining 24 were available for follow-up. Complications included lateral
Juvenile Chronic Arthritis results in the early degeneration of multiple joints with severe pain and deformity. Treatment of ankle arthritis is complex and ankle replacement is indicated because of adjacent and distant joint involvement. Materials and Methods. We reviewed 25 total ankle replacements in 13 young adults suffering the generalised consequences of Juvenile Chronic Arthritis (JCA) between 2000 and 2009. 12 had bilateral disease, 20 had anklylosis or prior fusion of the hind- or midfoot, and 16 had substantial fixed inversion of the hindfoot. All had previous prosthetic arthroplasty of between 1 and 15 joints. Surgery comprised corrective triple fusion where required, with staged total ankle arthroplasty at an interval of 3 or more months. Results. All patients reported significant reduction in pain, and increased mobility with increased stride length, however severe co-morbidity limited the usefulness of routine outcome scores. No ankles have required revision to date. We noted that the dimensions of the distal tibia and talus are markedly reduced in patients with JCA, and as a result of this and bone fragility, the
We aimed to review the outcome of Agility total ankle replacements carried out in our institution between 2002 and 2006. Follow-up consisted of clinical and radiological review pre-operatively, then at 6 weeks, 6 and 12 months, and annually until 10 years post op. Clinical review included the American Orthopaedic Foot and Ankle Score, satisfaction and pain scores. Case notes were reviewed to determine intra and post-operative complications. 30 arthroplasties were performed in 30 consecutive patients. Pre-operative diagnosis was rheumatoid arthritis(16), primary osteoarthritis(12) and post-traumatic osteoarthritis(2). After a mean follow up of 6.2 years (1.4–10.1), 4 patients had died, and 22 out of the remaining 24 were available for follow-up. Intra operative complications included lateral
We aimed to review the outcome of Agility total ankle replacements carried out in our institution between 2002 and 2006. Follow-up consisted of clinical and radiological review pre-operatively, then at 6 weeks, 6 and 12 months, and annually until 10 years post op. Clinical review included the American Orthopaedic Foot and Ankle Score, satisfaction and pain scores. Case notes were reviewed to determine intra and post-operative complications. 30 arthroplasties were performed in 30 consecutive patients. Pre-operative diagnosis was rheumatoid arthritis(16), primary osteoarthritis(12) and post-traumatic osteoarthritis(2). After a mean follow up of 6.2 years (1.4–10.1), 4 patients had died, and 22 out of the remaining 24 were available for follow-up. Intra operative complications included lateral
