Advertisement for orthosearch.org.uk
Results 1 - 20 of 21
Results per page:

The Lubinus SP II is an anatomical femoral stem with high survivorship levels notably described in the Swedish Arthroplasty Register. As the clinical and economic burden of revision total hip arthroplasty (THA) and periprosthetic fracture (PPF) continues to increase, it has been suggested that use of anatomical stems may facilitate more uniform cement mantles and improve implant survival. The primary aim of this study was to determine the long-term survivorship and PPF rate of the Lubinus SP II 150mm stem in a single UK centre.

Between January 2007 and April 2012, 1000 consecutive THAs were performed using the Lubinus SP II femoral stem in our institution. Patient demographics and operative details were collected in a prospective arthroplasty database. Patient records and national radiographic archives were then reviewed at a mean of 12.3 years (SD 1.3) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture.

Mean patient age at surgery was 69.3 years (SD 10.1, 24–93 years). There were 634 women (63%). Osteoarthritis was the operative indication in 974 patients (97%). There were 13 revisions in total (4 for recurrent dislocation, 3 for infection, 6 for acetabular loosening) and 16 dislocations (1.6%). Stem survivorship at 10 years was 99.6% (95 % confidence interval [CI], 99.5%–99.7%) and at 15 years was 98.8% (98.7%–98.9%). The 15-year stem survival for aseptic loosening was 100%. Analysis of all cause THA failure demonstrated a survivorship of 99.1% (99.0%–99.3%) at 10 years and 98.2% (98.1%–98.3%) at 15 years. There were 4 periprosthetic fractures in total (0.4%) at mean 12.3 year follow-up.

The Lubinus SP II stem demonstrated excellent survivorship, low dislocation rates and negligible PPF rates up to 15 years following primary THA. Use of anatomical stems such as the Lubinus SPII would appear to be a wise clinical and economic investment for patients and healthcare systems alike.


Bone & Joint Research
Vol. 11, Issue 12 | Pages 890 - 892
1 Dec 2022
Farrow L Jenkins PJ Dunstan E Murray A Blyth MJG Simpson AHRW Clement ND

Cite this article: Bone Joint Res 2022;11(12):890–892.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 11 - 11
1 Oct 2022
Dunstan E Wood L
Full Access

Introduction

Advanced practice physiotherapists (APPs) manage the national low back and radicular pain pathway across the UK. A novel spinal APP-led same-day emergency care (SDEC) pathway in Nottingham, manages patients referred from community services and the emergency department (ED). Patients may attend ED in the belief their pain is due to sinister or ‘red flag’ pathology. Little data exists on prevalence of spinal ‘red flag’ pathologies within a secondary care setting. This paper aims to review the number of ‘red flag’ pathology identified by APP's on a same-day emergency care pathway.

Methods

Retrospective data from 1 year of routinely collected information was extracted and analysed by two APPs. Counts were reported as a percentage of total patients seen on the SDEC unit over a one-year period and compared to nationally reported figures. A total of 2042 patients were assessed on the unit in 2021, of which, 293 (14%) had serious pathology identified.

Patients were classified into type of serious pathology: myelopathy (126, 6.1%), fractures (72, 3.5%), cauda equine compression (40, 1.9%), infection (37, 1.8%), cancers (28, 1.3%), neurological conditions (14, 0.6%) and other (16, 0.8%) serious pathology.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 38 - 38
1 Oct 2022
Wood L Dunstan E
Full Access

Background

NHS improvement advocates same day emergency care (SDEC) for patients requiring additional specialism than can be provided in an Emergency Department. A novel physiotherapist-led spinal SDEC unit was established in January 2020, integrated within the on-call spinal service. The aim of this paper was to evaluate patient and peer satisfaction with the spinal SDEC.

Methods

Patient satisfaction questionnaires and/or friends and family tests were collected from patients over a six-month period. Questionnaires evaluated satisfaction with recommendations given, service given, staff friendliness. Anonymous, completed questionnaires were uploaded onto a spreadsheet. Peer satisfaction was assessed using a google sheets document emailed to interface, primary care and community services. The questionnaire captured the respondents’ role, how many patients they had referred to the SDEC, reasons for referral, ease of referral, and compared this new pathway with the previous pathway.

All patient's satisfaction responses recommended the service to family and friends (n=110 extremely likely, 8 likely) (6% total seen). All respondents were satisfied with the service they received (n=80 very satisfied, n=12 satisfied) and recommendations made (n=86 very satisfied, n=6 satisfied). Of peer satisfaction, 26 respondents (n=12 (46%) physiotherapists, n=6 (23%) first contact practitioners, n=6 (23%) advanced practice physiotherapists, n=1 (4%) GP, n=1 (4%) nurse) reported the SDEC delivered a better pathway and outcomes (n=25, 96%), and 20 (77%) respondents reported favourable comments of the service and its impact on patients and referrers.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 39 - 39
1 Oct 2022
Dixon M Dunstan E Wiltshire K Wood L
Full Access

Background

Advanced spinal practitioner physiotherapists (ASPPs) assess and manage spinal referrals, as advocated by the National Low Back Pain Pathway in the United Kingdom. The ASPP pathway relies on multi-disciplinary team (MDT) meetings where potential surgically appropriate or complex cases can be discussed. Meetings were held with two different Consultant Spinal Neurosurgeons (total 2 meetings per month). The aim of this service evaluation was to assess MDT meeting outcomes and surgical listing.

Methods

This retrospective service evaluation used routinely collected MDT meeting documentation between May 2019 and October 2021. Data was extracted by two ASPPs, and 20% checked by a third ASPP. Extracted data included: number of patients discussed, Consultant, reason for discussion, and outcome (surgical listing or other). Data was analysed by two ASPPs using pivot tables in Microsoft Excel and was reported using counts and percentages across month and year.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 10 - 10
1 Oct 2022
Dunstan E Dixon M Wood L
Full Access

Introduction

Degenerative cervical myelopathy (DCM) is associated with progressive neurological deterioration. Surgical decompression can halt but not reverse this progression. The Modified Japanese Orthopaedic Assessment (MJOA) tool is recommended by international guidelines to grade disease severity into mild, moderate and severe, where moderate and severe are both recommended to undergo surgical intervention. During Covid-19 Nottingham University Hospitals (NUH) NHS Trust, identified DCM patients as high risk for sustaining permanent neurological damage due to surgical delay. The Advanced Spinal Practitioner (ASP) team implemented a surveillance project to evaluate those at risk.

Methods

A spreadsheet was compiled of all DCM patients known to the service. Patients were telephoned (Oct-Nov 2021) by an ASP. MJOA score was recorded and those describing progressive deterioration were reviewed by the ASP team on a spinal same day emergency assessment unit. Incident forms were completed for clinical deterioration and recorded as severe harm. Acute, progressive neurological deterioration was fast tracked for emergency surgical decompression.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 8 - 8
1 Oct 2022
Wood L Arlachov Y Dunstan E
Full Access

Background

Cauda equina syndrome (CES) is a spinal condition requiring emergency spinal surgery once diagnosed. The patient-reported symptoms are often subtle and none have been shown to be sensitive or specific in confirming CES. Magnetic resonance image (MRI) is the diagnostic gold standard, and guidelines recommend MRI access within 24-hours of symptom presentation. Limited sequence MRI scans (sagittal T2 sequences of the whole spine) have been shown to successfully identify patients with scan-positive CES despite reducing the duration of an MRI. The aim of this audit was to examine utilisation of same-day MRI requests by spinal practitioners from a newly operational same-day emergency care spinal unit over the two-year period.

Methods and results

Data was routinely collected over the two-year period and retrospectively reviewed. Data extraction occurred for cases of suspected CES with a same-day scan. Data extraction included type of MRI scan (lumbar/ whole spine/ CES protocol); outcome (admission/ discharge); final diagnosis. After clinical examination, only 258 (24% of 1085) suspected CES cases were identified and scanned within 24 hours, 58% (n=149) of which were with CES limited sequence scans. Only 12% (n=30) demonstrated scan- positive CES resulting in surgery within 24-hours. MRI same-day requests increased between 2020 (n=81, 21%) and 2021 (n=177, 26%), although utilisation of limited sequence scans improved (n=39, 48% in 2020; n=109, 62% in 2021).


Orthopaedic Proceedings
Vol. 103-B, Issue SUPP_7 | Pages 10 - 10
1 May 2021
Snowden G Clement N Dunstan E
Full Access

According to the Scottish Arthroplasty Project the mean inpatient LoS following a Total Hip Replacement (THR) has fallen from 10.3 days in 2001 to only 3.9 days. This reduction in patient LoS has lead units in the UK to follow the example of centres around the world in offering THR as a day case procedure. In this study we examine data gathered from the first 18 months of day case THR within a district general hospital elective orthopaedics unit.

Data was collected prospectively from all patients undergoing THR within our district general hospital elective orthopaedic unit. Patients were selected to day case THR group via consultant review at outpatient clinic and anaesthetic assessment at pre-assessment clinics. Between August 2018 and February 2020 (18 months) 40 patients successfully underwent day case THR. None of the patients discharged home where readmitted within the next 30 days. The average age of successful day case THRs was 60 years old. The at 6 months post-op mean OHS was 45.1 and at 1 year post-op the mean score was 47.2. The average improvement in OHS was 21.1 at 6 months and 26.9 at 1 year post-op. All of the patients successfully discharged as day cases where satisfied with their care and all but one would recommend it to their friends and family.

We have shown that day case THR is not only possible within an NHS district general hospital but gives exceptional patient outcomes with excellent patient satisfaction.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_19 | Pages 11 - 11
1 Nov 2017
Nicholson J Yapp L Dunstan E
Full Access

Increasing demands on our emergency department (ED) has resulted in the reduction of manipulations (MUAs) at the ‘front door’. We hypothesised that MUAs undertaken in theatre is rising with adverse financial implications. We performed a retrospective audit of operating lists in our institution from 2013–2016. Cost estimates were determined by our finance department. We used the NICE guidelines on management of non-complex fractures (NG38 Feb2016) as our audit standard.

Data on 1372 cases performed over a three-month representative period during 2013–2016 was analysed. MUAs were 13% of the total theatre workload, with an annual increase in volume noted. Additionally, simple displaced distal radius fractures were routinely receiving a MUA (with or without K-wires) as a primary procedure in theatre. When this workload is combined it makes up 22% of the total theatre workload. Average theatre time was 57 minutes per case. Delays to definite procedure ranged from 8 to 120 hours. Cost of hospital admission and theatre utilisation was approximately £1000 per patient. Conversely, the cost of a MUA in the ED was estimated at £150. Given that we currently undertake around 15 manipulations in theatre a month, performing such work in the ED it would save approximately £153,000 a year to our health board.

This audit identifies that MUAs of common orthopaedic injuries undertaken in theatre can lead too significant clinical and financial costs. We have proposed a strong financial argument to management for a twice weekly ‘manipulation list’ in the ED which is currently under review.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_12 | Pages 30 - 30
1 Nov 2015
Maempel J Clement N Ballantyne A Dunstan E
Full Access

Introduction

Total Hip Replacement (THR) is an effective treatment for end stage degenerative disease of the hip and offers patients the prospect of long term pain relief, improved joint function and quality of life. Enhanced Recovery Programmes (ERP) aim to standardise routine perioperative care, reduce hospital length of stay (LOS) and promote rapid recovery after elective surgery. The aim of this study was to determine whether the implementation of an ERP could successfully reduce the length of hospital stay associated with primary THR and whether this could be achieved without compromising the expected functional outcome or risking an increased dislocation rate.

Patients/Materials & Methods

Prospectively collected data on 1161 patients (611 managed with traditional rehabilitation and 550 with ERP) undergoing primary unilateral THR between 2005 and 2013 was retrospectively reviewed. Univariable statistical analysis was undertaken to identify factors that appeared to predict length of stay and a multiple linear regression model was then constructed to determine the significance and strength of effect of the individual predictors.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_V | Pages 9 - 9
1 Mar 2012
Sabnis B Dunstan E Ballantyne J Brenkel I
Full Access

Rivaroxiban is a factor Xa inhibitor and is a newer oral alternative for thromboprophylaxis after joint replacements. Its major advantage is its oral administration and hence better patient compliance. However there are some doubts about its efficacy compared to dalteparin/heparin. We have recently changed over from using dalteparin injections to rivaroxiban tablets for thromboprophylaxis after hip replacements. We assessed our results to find efficacy and specificity of its action in patients undergoing THR.

504 patients underwent hip replacement in last 2 years. 316 were treated with dalteparin injections (fragmin) for thromboprophylaxis while 189 patients were treated with oral rivaroxiban for 35 days after their hip replacement.

Average haemoglobin drop at 24 hours postop was 2.79 in Rivaroxiban group compared to 3. 10 in dalteparin group. 19 patients (of 189 i.e. 10.05%) required postop blood transfusion in rivaroxiban group as against 60 (of 315 i.e. 19.04%) in Dalteparin group. This difference was statistically significant. Incidence of DVT was no different in either groups, but the number of patients was too small to compare this.

Rivaroxiban appears to be more specific in its action and our results suggest a significant reduction in postop blood transfusion following hip replacements without any increase in rate of Deep Vein Thrombosis. We would like to present our findings and discuss role of oral thromboprophylaxis after joint replacements.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_III | Pages 62 - 62
1 Feb 2012
Dunstan E Ladon D Whittingham-Jones P Cannon S Briggs T Case P
Full Access

Purpose

Metal-on-Metal (MoM) hip bearings are being implanted in ever-increasing numbers and into ever-younger patients. The consequence of chronic exposure to metal ions is a cause for concern. Therefore, using cytogenetic biomarkers, we investigated a group of patients who have had MoM bearings in situ for in excess of 30 years.

Method

Whole blood specimens were obtained from an historical group of patients who have had MoM bearings in situ for in excess of 30 years. Blood was also obtained from an age and sex matched control group and from patients with Metal-on-Polyethylene (MoP) components of the same era. The whole blood was cultured with Pb-Max karyotyping medium and harvested for cytogenetics after 72 hrs. The 24 colour FISH (Fluorescent In Situ Hybridisation) chromosome painting technique was performed on the freshly prepared slides, allowing chromosomal mapping. Each slide was evaluated for chromosomal aberrations (deletions, fragments and translocations) against the normal 46 (22 pairs and two sex) chromosomes. At least 20 metaphases per sample were scored and the number of aberrations per cell calculated.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_I | Pages 63 - 63
1 Jan 2011
Macpherson G Rewhorn M Brenkel I Dunstan E Ballantyne J
Full Access

Our aim was to identify intra-operative and post-operative factors that predict those patients most at risk of dislocation.

Data was prospectively collected on a consecutive series of 2899 total hip replacements undertaken between July 1997 and December 2007. All operations were undertaken in one institution by fourteen orthopaedic consultants. In order to ensure accuracy, our regional database was cross-referenced with the Scottish Arthroplasty Project. Age; sex; BMI; surgeon; surgical approach; monthly caseload per surgeon; and the head size of the implanted prosthesis were analyzed using chi-squared tests for categorised factors and t-tests for quantitative factors.

Of the 2899 patients, 78 (2.7%) were found to have had one or more dislocation. BMI > 35kg/m2 was a significant pre-operative predictor of dislocation (P< 0.001). BMI < 35kg/m2 had a dislocation rate of 2.3% compared with a rate of 6.7% in those > 35kg/m2. Operating surgeon was the only intra-operative factor predictive of dislocation (P< 0.001). Head size was found to be insignificant.

Three surgeons with an overall dislocation rate of < 1% had a dislocation rate of 0.8% for patients with a BMI < 35kg/m2 and 2.0% for BMI > 35kg/m2. In comparison, the remainder of the surgeons had rates of 3.3% for BMI < 35kg/m2 and 9.6% for BMI > 35kg/m2.

Analysis of this consecutive series has shown that a BMI > 35kg/m2 is associated with a significant increase in rates of dislocation. The operating surgeon is also a significant factor and the highest risk is seen in surgeons with a > 1% overall dislocation rate operating on obese patients.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 363 - 364
1 Jul 2008
Dunstan E Ladon D Whittingham-Jones P Cannon S Case P Briggs T
Full Access

Background: Metal-on-Metal (MoM) hip bearings are being implanted in ever increasing numbers and into ever-younger patients. The consequence of chronic exposure to metal ions is a cause for concern. Therefore, by using cytogenetic biomarkers, we investigated a group of patients who have had MoM bearings in-situ for in excess of 30 years.

Method: Whole blood specimens were obtained from an historical group of patients who have had MoM bearings in-situ for in excess of 30 years. Blood was also obtained from an age and sex matched control group and from patients with Metal-on-Polyethylene (MoP) components of the same era.

The whole blood was cultured with Pb-Max karyotyping medium and harvested for cytogenetics after 72 h. The 24 colour FISH (Fluorescent In Situ Hybridisation) chromosome painting technique was performed on the freshly prepared slides allowing chromosomal mapping. Each slide was evaluated for chromosomal aberrations (deletions, fragments and translocations) against the normal 46 (22 pairs and two sex) chromosomes. At least 20 metaphases per sample were scored and the number of Aberrations per cell calculated.

Results: Chromosomal aberrations, including deletions, fragments and translocations were only detected in the peripheral blood lymphocytes isolated from the group that had MoM bearings. These changes were not present in the age and sex matched control group. The chromosomal aberrations were also detected in the patients previously exposed to MoM bearings who have been revised to a MoP articulation.

Conclusion: We have detected dramatic chromosomal aberrations in peripheral blood lymphocytes in a group of patients chronically exposed (over 30 years) to elevated metal ions. It is not known whether these aberrations have clinical consequences or whether they are reproduced in other cells in the body. The results emphasise the need for further investigations into the effect of chronic exposure to elevated metal ions produced by Orthopaedic implants.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 294 - 294
1 May 2006
Dunstan E Whittingham-Jones P Cannon S
Full Access

To reduce the disability after hip disarticulation customised endoprostheses have been used in our unit to preserve a proximal femoral above knee amputation stump. This procedure involves preservation of a musculocutaneous flap and insertion of a customised stump prosthesis that articulates with the acetabulum. This procedure has been performed not only for primary malignancy but also in the reconstructive setting. Six patients have undergone the above procedure with a good functional outcome-allowing mobilisation with an appropriate orthosis. We will discuss the complications of such a procedure that includes disassociation of the femoral head from the customised prosthesis.

We present the technique as a useful adjunct not only in the treatment of large proximal femoral tumours but also in the end stage reconstructive setting.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 355 - 355
1 Sep 2005
Dunstan E Sanghrahka A Tilley S Cannon S Blunn G Briggs T
Full Access

Introduction and Aims: Retrospective analysis of 25 consecutive metal-on-metal proximal femoral replacements performed at our unit between 1965 and 1979.

Method: Patients were clinically evaluated using the Modified Harris hip and Enneking Scoring Systems and radiologically evaluated using the ISOLOS scoring system. The concentration of Cr, Co, Ti, Al, V, Mo & Ni in whole blood and urine was also measured by High-Resolution Inductively Coupled Mass Spectrometry and compared with controls and patients with other implants.

Retrieved prostheses (in-situ for in excess of 25 years) were analysed for roughness and wear using a Mitutoya form tracer and an electron microscope.

Results: Thirteen patients have since died, nine from metastatic disease and four from other causes. Of the remainder, 11 (44%) are still alive, five still retaining metal-on-metal articulations and one has been lost to follow-up. They have been in-situ for an average of 32 years. The average modified Harris hip score is 76 (53–93) and the average Enneking Score is 74 (63–90).

In the retrieved prostheses the contact zones were found to be smoother (Ra 0.05mm), have fewer and smaller carbides, together with evidence of ‘self-healing’ when compared to the original surface (Ra 0.32mm).

Blood and urine levels of Co & Cr were significantly elevated. Co levels were exceptionally elevated in loose prostheses, but levels quickly fell following revision.

Conclusion: We have shown the potential longevity of metal-on-metal arthroplasty. The wear seen in retrieved specimens is low and we might expect to improve the fixation by reducing the torque with apical bearing and encouraging extra-cortical bone bridging with hydroxy-apatite-coated collars. Elevated serum and urine Co levels may well predict a loose prosthesis and may be useful as a screening tool.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 340 - 340
1 Sep 2005
Sanghrajka A Dunstan E Unwin P Briggs T Cannon S
Full Access

Introduction and Aims: We present a review of the long-term results of custom-made massive unicondylar femoral replacement for reconstruction following tumor excision, and compare the functional outcome of this procedure with prosthetic distal femoral replacement.

Method: Using our centre’s endoprosthetic database we identified and analysed all cases of massive unicondylar femoral replacement performed at our unit (group 1). Patients were evaluated for function, (Musculoskeletal Tumour Society System), and for stability (adapted from Oxford Knee Score). An age and sex-matched cohort of patients who had undergone distal femoral replacements for similar pathologies, and in who the follow-up was of a comparable time period (group 2) was evaluated in an identical manner. Statistical analysis was performed on the results.

Results: Twelve cases of massive unicondylar replacement have been performed between 1990 and 2001, for a variety of malignant and benign tumors. There have been no incidences of infection, aseptic loosening or tumor recurrence. One patient has died of metastatic disease and another has undergone revision to distal femoral replacement for osteoarthritis. Of the remaining 10 patients, nine were available for assessment

Each of the two groups consisted of five males and four females, with mean age 48 years in group 1 and 49 years in group 2. The average follow-up since surgery in both groups was 10 years. The mean MSTS and stability scores of group 1 were 83% and 3.9 respectively, and 71% and 3.2 for group 2; the difference in scores between groups was statistically significant (p< 0.02).

Conclusion: With stringent case selection criteria, the custom-made massive unicondylar femoral replacement produces a good outcome, with functional results significantly better than distal femoral replacement. This may be because a substantial proportion of the knee joint with at least one cruciate and one collateral ligament are kept intact, thus facilitating enhanced proprioception.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_III | Pages 297 - 297
1 Sep 2005
Hamilton P Dunstan E Maruthainar K Unwin P Cannon S Briggs T
Full Access

Introduction and Aims: Retrospective analysis of all uncemented massive endoprostheses inserted at our unit in the management of primary bone tumors with a minimum follow-up of five years.

Method: The case notes and radiographs of all patients were reviewed. The group consisted of a total of 52 patients, of which four (8%) were lost to follow-up. Kaplan-Meier Cumulative Survival Graphs were created for mortality, amputation, revision and infection for the whole group and for each individual prosthesis.

Results: The mean follow-up was seven years (63–107 months). The average age at time of insertion was 19 years; 26 patients were skeletally immature. The majority of implants were distal femoral (31) and proximal tibial (14). Osteosarcoma was the most common diagnosis.

The rate of infection was 12.5%, aseptic loosening 6%, amputation due to local recurrence 10% and the mortality 21%.

All the deaths occurred within three years of the implant being inserted and were all due to systemic progression of the disease. The amputations for local recurrence occurred throughout the follow-up period, the latest being at 71 months. Revisions for infections and aseptic loosening all occurred early (within three years). All cases of aseptic loosening occurred in distal femoral replacements (10%) and were related to divergent canals. Proximal tibial replacements had the highest rate of infection (23%). Rates of infection were not higher in the minimally invasive grower (12.5 %) when compared to the group as a whole.

Conclusion: We have shown a reduced rate of aseptic loosening (6%), particularly in the skeletally immature, when compared to our unit’s results for cemented fixed hinged prostheses. The uncemented prosthesis is a successful implant that needs careful consideration, especially in the skeletally immature. Careful pre-operative planning and surgical technique are of the utmost importance.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 5 - 5
1 Mar 2005
Hamilton P Dunstan E Maruthainar K Unwin P Cannon S Briggs T
Full Access

Retrospective analysis of all uncemented massive endoprostheses inserted at our unit in the management of primary bone tumours with a minimum follow up of 5 years.

Methods. The case notes and radiographs of all patients were reviewed. The group consisted of a total of 52 patients of which 4 (8%) were lost to follow up. Kaplan-Meier Cumulative Survival Graphs were created for mortality, amputation, revision and infection for the whole group and for each individual prosthesis.

Results. The mean follow up was seven years (63–107 months). The average age at time of insertion was 19 years; twenty-six patients were skeletally immature. The majority of implants were distal femoral (31) and proximal tibial (14). Osteosarcoma was the commonest diagnosis.

The rate of infection was 12.5%, aseptic loosening 6%, amputation due to local recurrence 10% and the mortality 21%.

All the deaths occurred within 3 years of the implant being inserted and were all due to systemic progression of the disease. The amputations for local recurrence occurred throughout the follow up period, the latest being at 71 months. Revisions for infections and aseptic loosening all occurred early (within 3 years). All cases of aseptic loosening occurred in distal femoral replacements (10%) and were related to divergent canals. Proximal tibial replacements had the highest rate of infection (23%). Rates of infection were not higher in the minimally invasive grower (12.5 %) when compared to the group as a whole.

Conclusion. We have shown a reduced rate of aseptic loosening (6%), particularly in the skeletally immature, when compared to our units results for cemented fixed hinged prostheses. The uncemented prosthesis is a successful implant that needs careful consideration, especially in the skeletally immature. Careful preoperative planning and surgical technique are of the utmost importance.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 5 - 5
1 Mar 2005
Dunstan E Sanghrajka A Tilley S Unwin P Cannon S Briggs T
Full Access

Retrospective analysis of 25 consecutive metal on metal proximal femoral replacements performed at our unit between 1965 and 1979.

Methods. Patients were: clinically evaluated using the Modified Harris Hip and Enneking Scoring Systems and radiologically using the ISOLOS scoring system.

The concentration of Cr, Co, Ti, Al, V, Mo & Ni in whole blood and urine was also measured by High-Resolution Inductively Coupled Mass Spectrometry and compared with controls and patients with other implants.

Retrieved prostheses (in situ for in excess of 25 years) were analysed for roughness and wear using a Mitutoya form tracer and an electron microscope.

Results. Thirteen patients have since died; nine from metastatic disease and four from other causes. Of the remainder, eleven (44%) are still alive, five still retaining metal on metal articulations and one has been lost to follow up. They have been in situ for an average of 32 years. The average modified Harris Hip score is 76 (53–93) and the average Enneking Score is 74 (63–90).

In the retrieved prostheses the contact zones were found to be smoother (Ra 0.05?m), have fewer and smaller carbides together with evidence of ‘self-healing’ when compared to the original surface (Ra 0.32?m).

Blood & urine levels of Co & Cr were significantly elevated. Co levels were exceptionally elevated in loose prostheses but levels quickly fell following revision.

Conclusion. We have shown the potential longevity of metal on metal arthroplasty. The wear seen in retrieved specimens is low and we might expect to improve the fixation by reducing the torque with apical bearing and encouraging extra-cortical bone bridging with hydroxy-apatite coated collars. Elevated serum and urine Co levels may well predict a loose prosthesis and may be useful as a screening tool.