Accuracy in hip surgery: assessment, consequence and solution

Hip arthroplasty is the most common and successful surgical treatment for the management of hip osteoarthrosis. However, complications arising from technical error in analysing the native hip, aswell as the position of the hip prosthesis can result in a suboptimal outcome for the patient. This thesis principally examines acetabular component orientation, investigating the use of technology in this critical aspect of hip arthroplasty surgery. In the first study, navigation technology is used to assess the performance of a current cohort of training and senior orthopaedic surgeons in a simulated surgical setting. A wide range of error in orientating an acetabular cup orientation to a target position is demonstrated. The second study seeks to establish a novel method of delineating the femoral neck axis in 3D using a sample of normal hip CT scans. Using such a proximal femoral frame of reference allows a standardised approach to assessing normal and abnormal hip morphology. The articular margin of the femoral head is shown to have a wave like pattern that consists of an anterior and posterior facet. The third study compares 2D and 3D measurements of inclination and version of acetabular components, finding a critical difference between the two in version measurements and that 3D measurements are more reliable. The thesis continues by examining the current methodology of analysing the concentration of cobalt and chromium metal ions in the joint fluid from a cohort of symptomatic patients with a metal on metal hip arthroplasty. A more robust laboratory method of processing fluid samples using a digestive oxidative method is presented. The relationship between concentrations of metal ion levels in joint fluid and several clinical parameters is investigated with no clear association shown, suggesting joint fluid in itself cannot be used as a marker for a failing metal on metal hip. The thesis concludes by comparing navigation technology to conventional ‘freehand’ method in orientating an acetabular component in a group of patients undergoing metal on metal hip resurfacing. The results suggest that navigation technology may substantially improve surgeon error in this task. Technology and three dimensional imaging can play a vital role in improving the accuracy of orientating an acetabular component in hip surgery. It can be employed in the pre-operative stages to assess trainee performance, intra-operatively to reduce surgical error and post operatively to investigate surgeon accuracy on CT imaging.Open Acces

Delayed Presentation of Lateral Femoral Circumflex Artery Injury Post Cannulated Hip Screw Surgery –A Case Report

An elderly patient underwent cannulated hip screw surgery for a subcapital neck of femur fracture.Nine days post surgery, she was noted to have collapsed with a falling haemoglobin level. Computed tomography revealed a large haematoma to the thigh. Further angiography showed active bleeding from one of the branches of the lateral femoral circumflex artery (LFCA),which we postulate was caused by the sharp tip of a version guidewire used during fracture fixation surgery. Iatrogenic injury during hip fracture fixation is a rare event,particularly to the circumflex branches of the profunda femoris artery (PFA), and may occur from hard wire use intraoperatively or from the fracture itself. The LFCA branches laterally from the PFA, runs anterior to the femoral neck,where we suspect it was injured in our case.Whilst a version wire is a useful radiological guide intra-operatively,manually clearing a passage for its insertion into the femoral head/neck junction and using the blunt end is recommended. A combination of acute swelling in the operated region and falling haemoglobin post surgery should alert the clinician to possible vascular injury.Compared to duplex ultrasonography,CT angiography remains the gold standard in its specificity and sensitivity for diagnosing arterial injuries.With early recognition and prompt radiological intervention, this rare complication of fracture fixation surgery can be treated without the need for further surgery

Combined single photon emission computerised tomography and conventional computerised tomography (SPECT/CT) in patellofemoral disorders : a clinical review

Patellofemoral disorders are common conditions seen in a knee clinic but can present a great diagnostic challenge to the orthopaedic surgeon. Combined single photon emission computerised tomography with conventional computer tomography (SPECT/CT) provides the clinician with precise anatomical and physiological information of the patellofemoral joint. We present a clinical review that highlights the value of SPECT/CT in patients with patellofemoral disorders, where other modalities such as radiographs, MRI, and conventional CT did not provide sufficient information. SPECT/CT has proven to be helpful for establishing the diagnosis and guidance for further treatment. SPECT/CT should be recognised as a valuable diagnostic tool in orthopaedic patients

Clinical value of combined single photon emission computerized tomography and conventional computer tomography (SPECT/CT) in sports medicine

Integrated hybrid single photon emission computerized tomography (SPECT)/computer tomography (CT) is a promising new diagnostic imaging modality for orthopedic patients. A high diagnostic yield is available from combining the detection of abnormal bone metabolism with SPECT, to the precise anatomical detail available in high resolution CT. With this review, we endeavor to illustrate the clinical value and future perspectives of SPECT/CT in sports medicin

Combined single-photon emission computerized tomography and conventional computerized tomography (SPECT/CT) : clinical value for the knee surgeons?

Single-photon emission computerized tomography in combination with conventional computer tomography (SPECT/CT) is an emerging technology that may hold great clinical value to the orthopaedic knee surgeon. Post-operative knee pain is a familiar condition seen in most orthopaedic clinics. Here, we present the value of SPECT/CT in three such cases of pain after surgical treatment of knee osteoarthritis (high tibial osteotomy, medial unicompartmental arthroplasty, total knee arthroplasty). In these patients with post-operative knee pain, SPECT/CT has proved to be beneficial in establishing the diagnosis and providing guidance for further treatment