As there is currently no evidenced-based and systematic way of prioritising people requiring JRS we aimed to develop a clinically relevant system to improve prioritisation of people who may require JRS. An important challenge in this area is to accurately assign a queue position and improve list management. To identify priority criteria areas eight workshops were held with surgeons and patients. Domains derived were pain, activity limitations, psychosocial wellbeing, economic impact and deterioration. Draft questions were developed and refined through structured interviews with patients and consultation with consultants. 38 items survived critical appraisal and were mailed to 600 patients. Eleven items survived clinimetric and statistical item reduction. Validation then included co-administration with standardised questionnaires (960 patients), verification of patient MAPT scores through clinical interview, examination of concordance with surgeon global ratings and test-retest. Ninety-six Victorian surgeons weighted items using Discrete Choice Experiments (DCEs). The DCE scaling generated a scale, which clearly ranked patients across the disease continuum. The MAPT differentiated people on or not on waiting lists (p<0.001), and was highly correlated with other questionnaires, e.g., unweighted-MAPT vs WOMAC (r=0.78), Oxford Hip/Knee (r=0.86/0.75), Quality of Life (r=0.78), Depression (r=0.64), Anxiety (r=0.60), p<0.001 for all. Test-retest was excellent (ICC=0.89, n=90). Cronbachs reliability was also high 0.85. The MAPT is now routinely administered across all Victorian hospitals undertaking arthroplasty where the response rate is generally above 90%. In the hands of clinicians the MAPT has been used to facilitate fast-tracking of patients with the greatest need, monitoring for deterioration in those waiting for surgery or having a trial of non-operative treatment and deferment of surgery for those that may benefit from further non-operative treatments. The MAPT is short, easy to complete and clinically relevant. It is a specific measure of severity of hip/knee arthritis and assigns priority for surgery. It has excellent psychometric and clinimetric properties evidenced by concordance with standard disease-specific and generic scales and widespread use and endorsement across health services.
Long waiting times and a growing demand on services for joint replacement surgery (JRS) prompted the Victorian Department of Human Services to fund a University of Melbourne/Melbourne Health partnership to develop and implement an osteoarthritis (OA) hip and knee service delivery and prioritisation system for those who may require JRS. The service delivery model consists of a multidisciplinary team providing, comprehensive early assessment, evidence-based interventions, including support for patient self-management, continuity of care processes, and prioritisation for both surgical assessment and JRS. Prioritisation occurs via clinical assessment and the Hip and Knee Multi-Attribute Prioritisation Tool (MAPT), a patient, clinician, or proxy-administered 11-item questionnaire, resulting in a 100-point scale ranking of need for surgery. The Hip and Knee MAPT was developed using intensive consultation with surgeons, state-of-the-art clinimetrics and with input from patients, hospital management groups. Ninety-six surgeons contributed to the developing the final scoring system. Over 4000 patients per year are entering the system across 14 hospitals in Victoria. Under the supervision of the orthopaedics unit, musculoskeletal coordinator (MSC), typically an experienced physiotherapist or nurse, as part of the multidisciplinary team, undertakes early comprehensive assessment, referral and prioritisation of patients with hip or knee OA referred to orthopaedic outpatient clinics. In addition, the MSC coordinates the monitoring and management of patients on the orthopaedic surgery waiting list. The processes enable patients who are most needy (via higher MAPT score and clinical assessment) to be fast-tracked to orthopaedic surgery; conversely those patients with lower scores receive prompt conservative management. Time to first assessment and waiting times to see a surgeon for many patients have reduced from 12+ months to weeks. Patients seen by surgeons are more likely to be ready for surgery and have had more comprehensive non-operative optimisation. Patients placed on the surgical waiting list receive quarterly reassessments and evidence of deterioration is used as a basis for fast-tracking to surgery. The OWL system is a whole of system(tm) approach informed by patients needs and surgeons needs. Clinicians have developed confidence in the clinical relevance of the MAPT scores. Uptake of the OWL model of care has been very high because it facilitates better care and better patient outcomes.
Hip fracture is a common cause of hospital admission and is often followed by reduced quality of life, or by death. International experiences indicate there are many benefits to be gained from national hip fracture registries. This pilot project aims to implement a hip fracture registry at three sites, a large metropolitan public hospital (Flinders Medical Centre), a large metropolitan private hospital (Epworth HealthCare) and a rural regional hospital (Goulburn Valley Health) to assess the feasibility of establishing a national registry. Patients undergoing surgery for a hip fracture will be recruited from the three participating hospitals between March and September 2009. A minimum data set will be collected at discharge, from hospital records. Items include patient demographics, fracture descriptors, length of stay, residential status, mobility, health status, surgical details and discharge destination. A phone interview at four months after surgery will measure outcomes by using the Extended Glasgow Outcomes Scale and documenting residential status, mobility, hip pain and readmissions. Re- operations, if any, will be collected. The availability of data from State Health Departments for validation of hospital case data will be reported. The pilot study is in progress at the time of writing. Ethical approval has been obtained, data collection, transmission and storage systems have been developed and deployed, and case data collection is underway. Case data will be summarised to describe hip fracture at the participating hospitals. Analysis will review the data elements in the pilot data set and assess their priority for inclusion in a national register—taking account of the quality of the data obtained and the time and other resources required for their collection. We will also evaluate the four-month review process. Any potential obstacles to a national registry that are identified during the pilot will be described and ways to overcome them will be proposed. A national hip fracture registry will improve the quality of care and safety of patients following hip fracture by developing an efficient mechanism to compare and improve the effectiveness of acute health care delivery by all hospitals involved in the management of hip fractures.
Percutaneous cannulated screw placement (PCSP) is a common method of fixation. In pelvic trauma neurovascular structures are in close proximity to the screw path. Pre-operative planning is needed to prevent injury. This study aims to the safety margin and accuracy of screw placement with computer navigation (CAS). A control had no pathology in the pelvis but CT scans were performed for suspected trauma. The treated group had pelvic and acetabular fractures and were treated with CAS PCSP at our institution. Using a new technique involving CT 3D modelling of the whole (3D) safe corridor, the dimensions of the Posterior elements (PE) of the pelvic ring and the anterior column of the acetabulum (AC) were measured in the control group. The accuracy of screw placement (deviation between the actual screw and planned screw) was measured in treated patient using a screenshot method and post-operative CTs. There were 22 control patients and 30 treated patients (40 screws). The mean ± (standard deviation, SD) minimum measurement of the safe corridor at the PE was 15.6 ± 2.3 mm (range 11.6 mm to 20.2 mm) and at the AC was 5.9 ±1.6 mm (range 3.0 mm to 10.0 mm). The mean ± (SD) accuracy of screw placement was 6.1 ± 5.3 mm and ranged from a displacement of 1.3 mm to 16.1 mm. There was a notable correlation between Body Mass Index, duration of surgery and inaccuracy of screw placement in some patients. The largest inaccuracy of screw placement was due to reduction of the fracture during screw insertion, causing movement of the bone fragments relative to the array and therefore also the computerised screw plan. There were no screw breakages, non-unions, neurological or vascular complications. CAS PCSP is a safe and accurate technique. However, the safe corridor is variable and often very narrow. We recommend that the dimensions of the safe corridor be assessed pre-operatively in every patient using 3D modelling to determine the number and size of screw that can be safely placed.
Perthes disease often leaves young adults with hip joint incongruency due to femoral head asphericity, (extra-articular extrusion and superior flattening). This causes femoro-acetabular impingement, a reduced range of movement and early degenerative change. We report a novel method for restoration of femoral head sphericity and femoro-acetabular congruency. Two males (aged 21 and 22 years) presented with groin pain and severe hip stiffness after childhood Perthes disease. Imaging confirmed characteristic saddle shaped deformities of the femoral head, with cartilage loss overlying a central depression in the superior section of the head. A new method of treatment was proposed. Both cases were treated in the same manner. A surgical dislocation was performed with a trochanteric flip osteotomy. The extra-articular bump was removed with osteotomes and a burr to reduce femoro- acetabular impingement. The sphericity of the femoral head was restored using a HemiCap partial re-surfacing (Arthrosurface, MA, USA). The radius of the implant was selected to match that of the acetabulum. Restoration of the height of the flattened portion of the weight-bearing surface of the femoral head reduces abnormal loading of the acetabular articular cartilage by improving congruency of the joint. Both patients recovered without incident and were mobilised with crutches, restricted to touch weight-bearing for six weeks to protect union of the trochanteric osteotomy. At a minimum of three year follow-up both patients had sustained improved range of movement, pain and Oxford hip score. Repeated imaging shows no evidence of joint space narrowing or loosening at this stage. We conclude that this novel treatment functions well in the short term. Further surveillance is on-going to confirm that this treatment results in improved long term durability of the natural hip joint after Perthes disease.
Restoration of the height of the flattened portion of the weight-bearing surface of the femoral head reduces abnormal loading of the acetabular articular cartilage by improving congruency of the joint. At a minimum of 3 year follow up both patients had sustained improved range of movement, pain and Oxford hip score. Repeated imaging shows no evidence of joint space narrowing or loosening at this stage.
This study aims to develop a pre-operative protocol for the Australian population, regarding the safe number of screws and size of screw that may be placed. Additionally, results from the study may help identify patients at increased risk of injury during PCSP.
Safe corridor measurements of the PE and AC were taken in the control patients. Pelvic CT scans, taken as part of trauma protocol, were reconstructed using 3D modelling and the dimensions of the whole (3 dimensional) safe corridor measured. The accuracy of screw placement was determined in each treated patient. Accuracy was assessed by the screenshot method, the post-operative CT method or by both methods. In both methods, accuracy was taken as the deviation between the positions of the actual screw and planned screw.
The mean ± (standard deviation, SD) minimum measurement of the safe corridor at the PE was 15.6 ± 2.3 mm (range 11.6 mm to 20.2 mm) and at the AC was 5.9 ±1.6 mm (range 3.0 mm to 10.0 mm). The mean ± (SD) accuracy of screw placement was 6.1 ± 5.3 mm and ranged from a displacement of 1.3 mm to 16.1 mm.
There are several different ways of preparing the femoral canal prior to cementing a hip prosthesis. This study investigated the mechanical strength of the cement-bone interface of four different types of preparation determined by the maximum tensile force required to separate a cemented prosthesis from its cancellous bone origin. Forty-eight fresh-frozen ox femora were prepared for hip arthroplasty, In a four-way comparison, groups of eleven femora were prepared by irrigation using
syringe injected normal saline; hydrogen-peroxide soaked gauze; pulse-lavage brushing; and pulse-lavage brushing and hydrogen-peroxide soaked gauze combination. Specimens were secured to a Material-test System (MTS), and the femoral implant pulled from the femur uni-axially at a rate of 5mm/min. The ‘pull-out strength’ was defined as the maximum tension recorded by the MTS during separation. Cement interdigitation was also inspected for each technique by microscopy of eight bone-implant transverse sections taken from prepared specimens. Following an analysis of variance and pair-wise Fisher comparison, the average pull-out strength of the cemented prosthesis was significantly higher (P<
0.001) using pulse-lavage brushing (mean 8049.2 N), and pulse-lavage brushing in combination with hydrogen-peroxide soaked gauze (mean 8489.1 N), than with normal saline irrigation (mean 947.1 N) or hydrogen-peroxide soaked gauze preparation (mean 1832.6 N). Prosthesis pull-out strength following pulse-lavage brushing in combination with hydrogen-peroxide soaked gauze was not significantly different (P>
0.05) than preparing with pulse-lavage brushing alone. Low and high power microscopy of specimen transverse sections revealed the greatest levels of cement penetration in specimens prepared using pulse-lavage brushing. This study demonstrated that one of the most effective preparations of the femoral canal for optimal mechanical fixation between cement and cancellous bone is pulse- lavage brushing. The use of hydrogen-peroxide soaked gauze in femoral canal preparation, either alone or in combination with pulse-lavage brushing, may not significantly improve prosthesis fixation.
Traditionally autologous bone graft is the standard treatment for non-union of fractures. More recently osteo-inductive agents with or without allograft have been utilised. A trial of Autologous Mesenchymal Precursor Cells has been completed at the Royal Melbourne Hospital to investigate their potential for the treatment of nonunion of long bone fractures. With the approval of the ethics committee at the Royal Melbourne Hospital a human safety trial was commenced for the treatment of fracture non-union. Bone marrow cells were harvested from patients approximately six weeks before surgery and cultured in a laboratory. The cells were expanded in a culture medium. At the time of definitive surgery the stem cells were implanted on a hydroxy apatite/tricalcium phosphate matrix to the non-union site. Any further fixation that was required at the time of the union was performed by the treating surgeon. Investigations were performed at regular intervals to assess for union and for any reaction to the stem cells and growth medium. The trial has been completed and eleven patients have been entered into the study. There were eight patients with non-union of femoral fractures and four patients with tibial non-unions (one patient with ipsilateral injuries to both bones). The average age was 41.9 years and the mean time to surgery from the initial injury was 15.2 months. Eight patients have united at a mean time of 24 weeks. One is well on the way to union and of the remaining two patients one is listed as uncertain and one a declared non union. The patient who has failed to unite is currently awaiting further surgery. One patient withdrew from the trial after ceasing smoking and finally uniting prior to stem cell implantation. There has been one adverse event with possible infection at a screw site though this was thought not to be related to stem cell therapy. This is a phase one safety trial of a new development for the treatment of a nonunion of long bone fractures. The results are promising with the regards to achieving bone union without any significant complications. This paves the way for a trial involving allogeneic stem cells.
Computer navigation was introduced in Australia in 2000, initially with the use of pre-operative computer scans and then later with image free systems. In 2003 the AOA – NJRR began collecting data for knee replacement performed with computer navigation. Meta analysis of the literature has shown better coronal and sagittal plane alignment in total knee arthroplasty performed with computer navigation as opposed to standard instrumented knee replacement. At present, however, there is no data on improved outcomes or reduced revision rates. Information was requested from the AOA – NJRR on the use of computer navigation for both uni-compartmental and total knee replacements. This included numbers of navigated knees done per year as well as revision rates and reasons for revisions of knees performed by computer navigation surgery. Since data collection began there has been 2,651 computer assisted total knee replacements performed which is 4.1% of the total number of knee replacements in this time period. There has been a steady increase in the last three years in the use of computer navigation. There has been an increased number of computer navigated knees performed in the private hospital sector as opposed to the public hospitals and there is a state by state variation in the uptake of navigation. The revision rate per 100 observed ‘component’ years at three years is 2.8 for non computer assisted and 2.5 computer assisted surgery. This is not statistically significant. There is no difference in the early complication rate leading to revision. The use of computer navigation could be expected to reduce the long term revision rates of knee arthroplasty due to better alignment and potentially less wear. In the short term there is no significant revision rate between the two methods of performing TKR particularly with regard to infection or fracture
Dislocation is a common reason for revision following total hip replacement. This study investigated the relationship between the bearing surface and the risk of revision due to dislocation. It was based on 110 239 primary total hip replacements with a diagnosis of osteoarthritis collected by the Australian Orthopaedic Association National Joint Replacement Registry between September 1999 and December 2007. A total of 862 (0.78%) were revised because of dislocation. Ceramic-on-ceramic bearing surfaces had a lower risk of requiring revision due to dislocation than did metal-on-polyethylene and ceramic-on-polyethylene surfaces, with a follow-up of up to seven years. However, ceramic-on-ceramic implants were more likely to have larger prosthetic heads and to have been implanted in younger patients. The size of the head of the femoral component and age are known to be independent predictors of dislocation. Therefore, the outcomes were stratified by the size of the head and age. There is a significantly higher rate of revision for dislocation in ceramic-on-ceramic bearing surfaces than in metal-on-polyethylene implants when smaller sizes (≤ 28 mm) of the head were used in younger patients (<
65 years) (hazard ratio = 1.53, p = 0.041) and also with larger (>
28 mm) and in older patients (≥ 65 years) (hazard ratio = 1.73, p = 0.016).
We followed up 76 consecutive hips with symptomatic acetabular dysplasia treated by acetabular shelf augmentation for a mean period of 11 years. Survival analysis using conversion to hip replacement as an end-point was 86% at five years and 46% at ten years. Forty-four hips with slight or no narrowing of the joint space pre-operatively had a survival of 97% at five and 75% at ten years. This was significantly higher (p = 0.0007) than that of the 32 hips with moderate or severe narrowing of the joint-space, which was 76% at five and 22% at ten years. There was no significant relationship between survival and age (p = 0.37) or the pre- and post-operative centre-edge (p = 0.39) and acetabular angles (p = 0.85). Shelf acetabuloplasty is a reliable, safe procedure offering medium-term symptomatic relief for adults with acetabular dysplasia. The best results were achieved in patients with mild and moderate dysplasia of the hip with little arthritis.