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Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 37 - 37
1 May 2012
Osborne R Bucknill A De Steiger R Brand C Graves S
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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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 49 - 49
1 May 2012
Bucknill A Gordon B Gurry M Clough L Symonds T Brand C Livingston J Hawkins M Landgren F De Steiger R Graves S Osborne R
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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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 191 - 191
1 May 2012
Wells V Graves S Ryan P Griffith E McDermott B Harrison J de Steiger R Critchley I Critchley J Jaarsma R
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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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 196 - 196
1 May 2012
Bucknill A Yew J Clifford J de Steiger R
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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.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIII | Pages 79 - 79
1 May 2012
Bucknill A de Steiger R
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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.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 512 - 512
1 Oct 2010
Bucknill A De Steiger R
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Introduction: Perthes disease often leaves young adults with hip joint incongruency due to femoral head asphericity, (an extra-articular extrusion and a superior flattening). This causes femoroacetabular impingement, a reduced range of movement and early degenerative change. We report a novel method for restoration of femoral head sphericity and femoroacetabular congruency.

Methods: 2 males (21 & 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 central depression and overlying cartilage loss. A new method of treatment was proposed. Both cases were treated in the same manner.

Results: Using a surgical dislocation with the trochanteric flip osteotomy it was possible to remove the extra-articular bump to reduce femoroacetabular impingement. We found that the sphericity of the femoral head could be restored using a HemiCap partial resurfacing (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.

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.

Conclusion: We conclude that this novel treatment functions well in the short term. Further studies are needed to confirm that after Perthe’s disease this treatment results in improved long term durability of the natural hip joint.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 545 - 545
1 Oct 2010
Bucknill A Clifford J De Steiger R Yew J
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Introduction: Percutaneous cannulated screw placement (PCSP) is a safe method of internal fixation, indicated for pelvic ring fractures. Due to the close proximity of neurovascular structures to the path of the screw placed in either the Posterior elements (PE) or Anterior column (AC), pre-operative planning is needed to prevent injury.

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.

Methods: All patients were from the Australian population and had been admitted into the emergency department at The Royal Melbourne Hospital. Control patients had no pathology in the pelvis, while treated group patients had pelvic ring fractures and were treated with 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.

Results: There were 22 control patients and 12 treated patients.

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.

Conclusion: The minimum dimensions of the safe corridor and the accuracy of screw placement occurred over a wide range. We recommend that dimensions of the safe corridor be assessed pre-operatively in every patient using 3D modelling to determine the safe number and size of screw that can be placed.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_IV | Pages 529 - 530
1 Oct 2010
Sexton S De Steiger R Jackson M Stanford T Walter W
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Introduction: Dislocation is the most common complication resulting in re-operation following total hip arthroplasty, accounting for 33.5% of revisions. This study investigates the relationship between bearing surface and the risk of revision due to dislocation.

Materials and Methods: Analysis was based on 110,239 primary total hip arthroplasties with a primary diagnosis of osteoarthritis. Data were collected by the Austra-lian Orthopaedic National Joint Replacement Registry from September 1999 to December 2007. The bearing surfaces were: 20627 (18.7%) ceramic-on-ceramic, 14001 (12.7%) ceramic-on-polyethylene, 12208 (11.1%) metal-on-metal, and 62437 (56.6%) metal-on-polyethylene. In 966 (0.8%) hips the bearing surface was unknown.

Results: There were 862 (0.8%) hips revised due to dislocation, with a rate of 0.3 revisions per 100 component years. Survival analysis with an end point of revision due to dislocation was performed. Revision for dislocation is potentially associated with variables other than bearing surface (including age and femoral component head size). Therefore analyses were stratified by femoral head size (≤28mm and > 28mm), and age (< 65 years and ≤65 years). There is a significantly higher rate of revision for dislocation in ceramic-on-ceramic bearing surfaces compared to metal-on-polyethylene bearing surfaces after adjustment for age, sex and head size in the head size < =28mm/Age < 65 group (hazard ratio = 1.53, 95% C.I. = 1.02 to 2.30, p=0.041) and the head size > 28mm/Age > =65 group (hazard ratio = 1.73, 95% C.I. = 1.10 to 2.74, p=0.016).

Discussion: Ceramic-on-ceramic bearing surfaces have a higher risk of revision due to dislocation in the femoral head sizes and ages discussed above, compared with metal-on-polyethylene. Possible mechanisms for this observed difference may include patient selection, the limits to head and liner offset options when using ceramic bearing surfaces or higher rates of revision after dislocation due to ceramic head or liner damage. However our results are based on a seven year follow-up, and higher rates of late dislocation with polyethylene bearings may be observed in association with higher wear rates compared with ceramic liners.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 183 - 183
1 Mar 2010
Ackland D Yap V Hardige A Ackland M Williams J de Steiger R
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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.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 203 - 204
1 Mar 2010
de Steiger R Farrugia R Richardson M Graves S
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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.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 197 - 197
1 Mar 2010
de Steiger R Mercer G Graves S
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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


The Journal of Bone & Joint Surgery British Volume
Vol. 91-B, Issue 11 | Pages 1448 - 1453
1 Nov 2009
Sexton SA Walter WL Jackson MP De Steiger R Stanford T

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).


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 385 - 385
1 Oct 2006
Fawzy E Mandellos G Isaac S Pandit H Gundle R De Steiger R Murray D McLardy-Smith P
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Aim: To investigate the functional and radiological outcome of shelf acetabuloplasty in adults with significantly symptomatic acetabular dysplasia, with a minimum of a 5 year follow-up.

Material and Methods: 77 consecutive shelf procedures (68 patients) with an average follow-up of 10.9 years (range: 6–14) were reviewed. The Oxford hip score (OHS) was used for clinical assessment. Centre-edge angle (CEA) and acetabular angle (AA) were measured as indicators of joint containment. The severity of osteoarthiritis was based primarily on the extent of joint space narrowing. Survivorship analyses using conversion to THR as an endpoint were performed. Logrank tests were used to compare the survivorship of the shelf procedure against the variables of age, preoperative osteoarthiritis, pre and postoperative AA, CEA angles.

Results: The average age at time of surgery was 33 years (range: 17–60). At the time of the last follow-up, the mean OHS was 34.6 (maximum score: 48). Mean postoperative CEA was 55 (Pre-operatively: 13 degrees) while mean postoperative AA was 31 (Pre-operatively: 48 degrees). Thirty percent of hips needed THR at an average duration of 7.3 years. The survival in the 45 patients with only slight or no joint space narrowing was 97% (CI, 93%–100%) at 5 years and 80% (CI, 56%–100%) at 10 years. This was significantly higher (p= 0.0007) than the survival in the 32 patients with moderate or severe osteoarthiritis, which was 72% (CI, 55%–89%) at 5 years and 29% (CI, 13%–45%) at 10 years. There was no significant relationship between survival and age, pre and postoperative AA, CEA angles (p> 0.05).

Conclusion: Shelf-acetabuloplasty offers symptomatic relief to adults with acetabular dysplasia but overall deteriorates with time. About 50% of the patients do not need THR for over 10 years. Best results with shelf-acetabuloplasty were achieved in patients with slight or no joint narrowing.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 440 - 441
1 Oct 2006
de Steiger R
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Introduction: With the increasing use of CAOS techniques in Orthopaedic Surgery it is important to be aware of verification studies and sources of error that can occur. Computer assisted navigation systems should be tested with a known true standard such as a phantom model and then verified with cadaver studies before clinical trials are instituted. Errors can occur.

Materials and Methods: A major focus for hip arthroplasty navigation has been on acetabular cup anteversion and inclination. Non CT navigation systems rely on an anterior pelvic plane, which is selected by the surgeon. This study looked at repeated measurements of a surgeon’s ability to manually pick the pubic symphysis and the ASIS and compared this to the same points selected fluoroscopically. A navigated acetabular cup was performed aiming for abduction of 45° and anteversion of 20°. The software model was then manipulated to transpose the different registrations to see what compound effect the anterior pelvic plane error would have.

Results: Significant intra and inter observation error was recorded for registration by palpation compared to points registered by the fluoroscopic method. An error of up to 9.6° cup inclination and 11.2 ° cup anteversion could be introduced with a palpation method.

Conclusion: This cadaver study indicates that with hip arthroplasty, registration from a fluoroscopic image was more accurate with a respect to determining the anterior pelvic plane when compared to direct palpation. Like all surgery done with computer navigation, registration requires an accurate determination of the points that the software needs for calculation. This must always be borne in mind when evaluating methods for CAOS.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 440 - 440
1 Oct 2006
de Steiger R
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Introduction: Computer assisted Orthopaedic surgery (CAOS) has a lot to offer in orthopaedic trauma surgery. Based on real time fluoroscopic images CAOS can optimise the treatment of bone fractures while importantly reducing radiation exposure to both surgeon and patient. We describe our early experience with the use of the Brain LAB Vector Vision trauma software for the treatment of femoral shaft fractures with intramedullary nailing and distal cross bolting.

Materials and Method: At the beginning of the procedure two minimally invasive reference arrays are attached to the proximal and distal femur. Seven fluoroscopic images are acquired and automatically transferred to the navigation unit. These images are used to identify the shaft axis of both fragments, the neck axis and the posterior condylar axis to control alignment and rotation. Segmentation of the distal fragment is also performed to facilitate real time movement of the fragments during reduction. Two more fluoroscopic images are acquired once the nail is inserted to plan and navigate the interlocking screws. The software displays a real-time position of the drill guide during screw navigation. AO titanium femoral nails were used in all cases.

Results: Like all new introductions of CAOS technology there are problems to solve and tips that improve the technique. Specifically, proximal pin fixation needs to be rigid and is best put in to the greater trochanter to prevent obstruction of the nail. Real time fracture reduction has been easily achieved. Distal cross bolting requires at the present stage a further two fluoroscopic images when the nail is inserted. Navigation of the drill bit is accurate, but care needs to be taken because of the potential motion of the tip of the drill bit. As the software is generic any manufacturer’s nail can be inserted. There may be some advantage, however, in viewing a virtual nail insertion based on stored data in the software.

Conclusion: Acquiring good images and positioning of the navigation unit are key factors in successfully treating a femoral nail with the aid of CAOS. Already significant time savings in radiation exposure have been achieved in the early cases and this is expected to improve with more experience.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 129 - 129
1 Mar 2006
Fawzy E Mandellos G De Steiger R McLardy-Smith P Benson M Murray D
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Background: Hip dysplasia is a complex developmental process. Untreated acetabular dysplasia is the most common cause of secondary hip osteoarthiritis. With increased interest in redirectional pelvic osteotomies, the role of the shelf procedure needs to be re-defined.

Aim of the study: to investigate the effectiveness of the shelf procedure in adults with symptomatic acetabular dysplasia by assessing the functional and radiological outcome at a minimum of five years follow-up.

Material and Methods: Seventy-six consecutive adults with symptomatic acetabular dysplasia treated with acetabular shelf augmentation, have been followed up for an average period of 11 years (range: 6–14). The mean age was thirty-three years (range: 17–60 years). The Oxford hip score (OHS) was used for clinical assessment. Centre-edge angle (CEA) and acetabular angle (AA) were measured to determine femoral head coverage. Osteoarthiritis severity was based primarily on the width of the joint space using the De Mourgues classification. Survivorship analyses using conversion to THR as an endpoint were performed. logrank test was used to compare the outcome of the shelf against the variables of age, preoperative osteoarthiritis, preoperative and postoperative AA, CEA angles.

Results: The shelf procedure improved the mean preoperative CEA from 11° (range: 20° to 17°) to 50° postoperatively (range: 30° to 70°) and the mean preoperative AA from 52° (range: 46° to 64°) to 32° postoperatively (range: 18° to 57°). The Mean OHS was 34.6 (hip score maximum: 48). Thirty percent of hips needed THR at an average duration of 7.3 years. Survival analysis using conversion to THR as an endpoint was 86% (CI, 76%–95%) at five years and 46% (CI, 27%–65%) at ten years. The survival in the 44 patients with only slight or no joint space narrowing was 97% (CI, 93%–100%) at 5 years and 75% (CI, 51%–100%) at 10 years. This was significantly higher (p= 0.0007) than the survival in the 32 patients with moderate or severe osteoarthiritis, which was 76% (CI, 55%–89%) at 5 years and 22% (CI, 5%–38%) at 10 years. There was no significant relationship between survival and age (p= 0.37), pre and postoperative centre-edge angle (p= 0.39), or acetabular angle (p= 0.85).

Conclusion: 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 slight or no joint space narrowing.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 359 - 360
1 Sep 2005
De Steiger R
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Introduction and Aims: The standard treatment for an infected total hip replacement involves removal of all foreign material and re-implantation in either one or two stages with antibiotic cement. This study has investigated the use of cementless reconstruction in infected hip arthroplasties to determine if there is a difference in the re-infection rate.

Method: Thirteen patients (three females and 10 males) with an average age of 67 have been followed-up prospectively after revision hip surgery for infection. Removal of the prosthesis was followed by six weeks intravenous antibiotics and in some cases a period of oral therapy. Reconstruction was undertaken at a median of four months post Girdlestone’s arthroplasty, with the exception of a one-stage exchange for medical reasons. Cementless titanium femoral components were used in all revisions and titanium acetabular components where applicable. Allograft and cage reconstruction were employed for major pelvic defects.

Results: Patients have been followed-up for an average of 58 months (range 12–96 months), with no loss to follow-up. Bacteria were cultured from eleven (11) of the thirteen (13) patients and the other two were clinically septic. Bacteria cultured included MRSA, Staph. Aureus, E.Coli and Strep. Faecalis. All prostheses remain in situ with improvement in both Charnley and Oxford hip scores. No recurrence of infection has been documented clinically or radiologically and no component is loose.

Conclusion: Debate still exists about the merits of one vs. two-stage reconstruction for infected hip arthroplasty. This series with mid-term follow-up demonstrates that cementless reconstruction for infected hip arthroplasty is successful in providing an infection-free stable revision.


The Journal of Bone & Joint Surgery British Volume
Vol. 87-B, Issue 9 | Pages 1197 - 1202
1 Sep 2005
Fawzy E Mandellos G De Steiger R McLardy-Smith P Benson MKD Murray D

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.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 40 - 40
1 Mar 2005
Fawzy E Mandellos G Isaac SM Pandit H Gundle R De Steiger R Murray D McLardy-Smith. P
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Aim: To investigate the functional and radiological outcome of shelf acetabuloplasty in adults with significantly symptomatic acetabular dysplasia, with a minimum of a 5 year follow-up.

Material and Methods: 77 consecutive shelf procedures (68 patients) with an average follow-up of 10.9 years (range: 6–17) were reviewed. The Oxford hip score (OHS) was used for clinical assessment. Centre-edge angle (CEA) and acetabular angle (AA) were measured as indicators of joint containment. The severity of osteoarthiritis was based primarily on the extent of joint space narrowing. Survivorship analyses using conversion to THR as an endpoint were performed. Logrank tests were used to compare the survivorship of the shelf procedure against the variables of age, preoperative osteoarthiritis, pre and postoperative AA, CEA angles.

Results: The average age at time of surgery was 33 years (range: 17–60). At the time of the last follow-up, the mean OHS was 34.6 (maximum score: 48). Mean postoperative CEA was 55 (Pre-operatively: 13 degrees) while mean postoperative AA was 31 (Pre-operatively: 48 degrees). Thirty percent of hips needed THR at an average duration of 7.3 years. The survival in the 45 patients with only slight or no joint space narrowing was 97% (CI, 93%-100%) at 5 years and 75% (CI, 51%-100%) at 10 years. This was significantly higher (p≤= 0.0007) than the survival in the 32 patients with moderate or severe osteoarthiritis, which was 76% (CI, 55%-89%) at 5 years and 22% (CI, 5%-38%) at 10 years. There was no significant relationship between survival and age, pre and postoperative AA, CEA angles (p> 0.05).

Conclusion: Shelf-acetabuloplasty offers symptomatic relief to adults with acetabular dysplasia but overall deteriorates with time. About 50% of the patients do not need THR for over 10 years. Best results with shelf-acetabuloplasty were achieved in patients with slight or no joint narrowing.


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_IV | Pages 466 - 466
1 Apr 2004
Ahmad S Plehwe W de Steiger R
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Introduction Vitamin D deficiency has been reported widely in various community groups but especially in the osteoporotic/fracture population. We decided to investigate the incidence in an elective female population undergoing hip or knee arthroplasty as this has not been previously reported.

Methods Data was collected prospectively from a group of female patients who were undergoing hip or knee arthroplasty for osteoarthritis. Patients with rheumatoid or inflammatory arthritis were excluded, as were patients on Vitamin D supplements. Serum 25-hydroxyvitamin D (25 OHD) levels were measured as part of routine pre-operative work-up. A total of 40 female patients over a 12 month period were checked, with average age 66 years (range 15 to 93 years). Average height was 151 cm and weight 67 kg. Thirty total hips and 10 total knee replacements were performed. Vitamin D deficiency was classified as either marginal (25 OHD levels ranging from 25 to 50 nmol/L or frank (25 OHD levels, < 20–25 nmol/L).

Results Eleven patients out of 40 (27.5%) had marginal deficiency and four of those patients (10%) had frank vitamin D deficiency. There was no correlation with height or weight or age.

Conclusions This small study suggests that a significant percentage of patients undergoing elective lower limb arthroplasty for osteoarthritis have low Vitamin D levels.