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The Bone & Joint Journal
Vol. 99-B, Issue 5 | Pages 592 - 600
1 May 2017
Matharu GS Nandra RS Berryman F Judge A Pynsent PB Dunlop DJ

Aims

To determine ten-year failure rates following 36 mm metal-on-metal (MoM) Pinnacle total hip arthroplasty (THA), and identify predictors of failure.

Patients and Methods

We retrospectively assessed a single-centre cohort of 569 primary 36 mm MoM Pinnacle THAs (all Corail stems) followed up since 2012 according to Medicines and Healthcare Products Regulation Agency recommendations. All-cause failure rates (all-cause revision, and non-revised cross-sectional imaging failures) were calculated, with predictors for failure identified using multivariable Cox regression.


The Bone & Joint Journal
Vol. 98-B, Issue 11 | Pages 1455 - 1462
1 Nov 2016
Matharu GS Berryman F Brash L Pynsent PB Dunlop DJ Treacy RBC

Aims

We investigated whether blood metal ion levels could effectively identify patients with bilateral Birmingham Hip Resurfacing (BHR) implants who have adverse reactions to metal debris (ARMD).

Patients and Methods

Metal ion levels in whole blood were measured in 185 patients with bilateral BHRs. Patients were divided into those with ARMD who either had undergone a revision for ARMD or had ARMD on imaging (n = 30), and those without ARMD (n = 155). Receiver operating characteristic analysis was used to determine the optimal thresholds of blood metal ion levels for identifying patients with ARMD.


Bone & Joint Research
Vol. 5, Issue 2 | Pages 52 - 60
1 Feb 2016
Revell PA Matharu GS Mittal S Pynsent PB Buckley CD Revell MP

Objectives

T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty.

Methods

In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 420 - 420
1 Jul 2010
Matharu GS Pynsent PB
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Study Objective: To determine the proportion of patients proceeding to elective total knee arthroplasty with pre-operative anaemia.

Background: Over 60,000 primary total knee replacements are performed in England and Wales each year. Blood transfusion can be associated with serious complications. A pre-operative haemoglobin of less than 12 g/dl increases the likelihood of blood transfusion in the peri-operative period by threefold [1]. Published BOA guidelines recommend patients with pre-operative haemoglobins of 12 g/dl or below in males or 11 g/dl or below in females should have their anaemia investigated and treated prior to total knee arthroplasty.

Methods: Patients having elective total knee arthroplasty at our hospital over three-months formed the study population. Data were collected on age, sex, pre- and postoperative haemoglobin, transfusion requirements in the peri-operative period, and whether the patient had inflammatory arthritis. Patients were classified according to the recommended BOA guidelines for deferring elective surgery using pre-operative haemoglobin levels. Post-operative haemoglobin drop was also calculated.

Results: Fifteen patients (7%) out of 212 had pre-operative haemoglobins below guideline thresholds. The age range of these patients was 59–84 yr. Nine patients were female. Pre-operative haemoglobin ranged from 9.2–12.0 g/dl. Post-operative haemoglobin drop ranged from 0.5–4.3 g/dl. Six patients received blood transfusion in the peri-operative period (maximum of three units). One patient had a diagnosis of inflammatory arthritis.

Discussion: Pre-operative anaemia is common in patients having elective total knee arthroplasty. In this study most anaemic patients did not have anaemias attributable to inflammatory arthritis. Using cell salvage techniques did not prevent peri-operative blood transfusion in anaemic patients.

Conclusion: Anaemic patients wanting arthroplasty in favour of surgical deferral and treatment of their anaemia must be made fully aware of the serious complications associated with blood transfusions.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 552 - 552
1 Aug 2008
Ziaee H Daniel J Pynsent PB McMinn DJW
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Introduction: The potential adverse effects of metal ion elevation in patients with metal-metal bearings continue to be assessed. We reported earlier that metal ions cross the placenta. The present report is a comparison of the rate of transfer in 14 study patients (with MM devices) and 24 control subjects (with no metal devices).

Methods: Whole blood from concurrent specimens of maternal and umbilical cord blood obtained at the time of delivery were analysed with high resolution inductively coupled plasma mass spectrometry.

Results: Cobalt and chromium were detectable in all specimens in the control subjects and study patients. The mean difference between maternal and cord blood cobalt concentrations was 0.56 μg/l (p < 0.001) in the study group and 0.03 μg/l (p > 0.5) in the control group respectively (figure). The mean difference between maternal and cord blood chromium concentrations was 0.96 chromium (p < 0.0005) in the study group and 0.002 chromium (p > 0.5) in the control group respectively. The mean cord cobalt in the study patients was significantly higher than that in the control subjects (difference 0.38μg/l, p < 0.01) but the difference in the cord levels of chromium between study and controls (difference 0.13μg/l, p> 0.05) was not significant.

Discussion: There was almost no difference between the maternal and cord blood levels in the control group implying that the placenta offers almost no resistance to their passage in subjects without a metal device. In the study patients the mean cord cobalt level was 59% of the maternal level and the mean cord chromium level was 26% of the maternal level suggesting that the placenta exerts a modulatory effect on the rate of metal transfer when the maternal levels are higher


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 531 - 531
1 Aug 2008
Daniel J Ziaee H Pynsent PB McMinn DJW
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Introduction: The Birmingham Hip Resurfacing (BHR) device was introduced in 1997 as a conservative hip arthroplasty option for young patients with severe arthritis. Primary osteoarthritis is the most common etiology of hip arthritis in the West. Excellent early and medium-term results have been reported with the BHR. This is a 9–year review of the first 100 consecutive BHRs performed by one surgeon (DJWM) for primary OA.

Methods: The first 100 BHRs (91 patients) performed for OA are now at a mean follow-up of 9.1 (range 8.9 to 9.3) years. Four patients (5 hips) died 5.2 to 6.9 years later due to unrelated causes. Patients with unrevised hips were reviewed clinico-radiologically and with questionnaire assessment.

Results: With revision for any reason as the end-point there were four failures (two were post-operative AVN leading to femoral head collapse, 8 months and 7 years after their respective operations; and two were deep infections both 5 years after operation). Kaplan-Meier survival analysis showed a 96% cumulative survival at 9 years (figure). There were no failures from osteolysis or aseptic loosening and no patient is awaiting a revision for any reason.

Discussion: The performance of the BHR continues to be good at 9 years. Arthroplasty devices are known to manifest two phases of failure, one in the early years and another in the later years. Early failure with this device has been very low. The interim years are continuing to be promising and we are yet to find out when the late failures, if any, are likely to occur.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 542 - 542
1 Aug 2008
Dehne K McBryde CW Pynsent PB Pearson AM Treacy RBC
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Introduction: Patients suitable for hip resurfacing are often young, active, in employment and have bilateral disease. One-stage bilateral total hip replacement has been demonstrated to be as safe as a two-stage procedure and more cost effective. The aim of this study was to compare the results of one-stage with two stage bilateral hip resurfacing.

Methods: Between July 1994 and August 2006 a consecutive series of 93 patients underwent bilateral hip resurfacing within a year. 34 patients in the one-stage group. 44 patients in the two-stage group. The age, gender, diagnosis, ASA grade, total operative time, blood transfusion requirements, medical and surgical complications, length of stay, revision and costs were recorded.

Results: There were no significant differences in age, gender, and ASA grade between the two groups. There were 4 minor complications in the one stage group and 5 in the two-stage group. All complications were of a short-term nature. There was no significant difference in the blood transfusion requirements. There was a significantly longer total mean hospital stay of 5 days (95% c.i. 4.0–6.9) for the two-stage group. No patients had undergone a revision. The hospital received a mean of £6338 per patient for the one-stage group and a mean of £9726 per patient for the two-stage group. However, this included a longer total hospital stay, two anaesthetics and on average two extra out-patient appointments.

Conclusions: This study demonstrates no detrimental effects when performing a one-stage bilateral hip resurfacing in comparison to a two-stage procedure. The advantages of the one-stage procedure are that total hospital stay is reduced by a mean of 5 days and the cost is reduced by a mean of £3388 per patient, a 35% reduction of the cost of a two-stage procedure. These benefits do not appear to come at the cost of increase complications.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 223 - 223
1 Jul 2008
Gakhal DK Reynolds EM Chakraverty RC Pynsent PB
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Purpose And Background: In patients with chronic low back pain (LBP), selective injection procedures (provocative discography, medial branch, facet and sacroiliac joint blocks) have shown the pain source to be the intervertebral disc in 40%, the sacroiliac joint in 13–19% and the facet joints in 15–40%. No individual features in the history or examination are of consistent discriminatory value in diagnosis.

This study aimed to assess whether patients with different pain sources could be differentiated using the Oswestry Disability Index (ODI) (a validated patient questionnaire scoring ten different aspects of pain and function in patients with LBP; higher scores correlating with greater disability).

Methods And Results: ODI scores were recorded from 67 patients (46 female, age 17–82) whose source of LBP was subsequently confirmed by selective injection. The scores for each section of the ODI were compared between patients grouped according to pain origin; disc (n=11), sacroiliac (n=31) or facet (n=25).

Patients with disc pain had significantly greater overall disability and scored higher for sitting, sleeping and social activity than those with facet or sacroiliac pain as judged by the 95% confidence limits of the median (p< 0.05). Patients with facet pain scored higher for walking and standing compared to those with sacroiliac pain.

For disc pain scores were higher for sitting and standing than for walking, and for facet pain scores were higher for standing than for sitting or walking.

Conclusion: Although the ODI is not a diagnostic tool, analysis of its components reveals characteristic pain and disability patterns in patients sub-grouped according to pain source.


Orthopaedic Proceedings
Vol. 87-B, Issue SUPP_I | Pages 73 - 73
1 Mar 2005
Ramisetty NM Abudu A Pynsent PB
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The histological findings from the heads of femur or bone biopsy taken from 90 patients with suspected pathological fractures of the femoral neck were studied to determine the rates of significant abnormal pathological findings.The mean age at the time of fracture was 80.41 years (44–99). 29 patients were males and 71 females. The patients were divided into four groups. Group I: 34 patients with fracture without history of fall or trauma. Group II: 21 patients with suspicious radiology of pelvis. Group III: 27 patients with past history of malignancy without known bone metastases. Group IV: 8 patients with past history of malignancy and known bone metastases

None of the patients in groups I and II had significant abnormalities other than osteoporosis. 4 patients (15%) in group III had metastases and 6 patients (75%) in group IV had metastases on histological examination.

We conclude that the absence of history of fall or trauma or subtle radiographic findings in patients with fracture of the neck of the femur is usually not associated with sinister pathology and the cause of fracture in these patients is often osteoporosis. Patients with previous history of malignancy without known bone metastases have a 15% risk of finding of metastatic disease even in the absence of radiological abnormalities. Patients with fractured neck of femur with past history of malignancy and who are known to have bone metastases must be considered as having pathological fractures through metastatic disease until unless proven otherwise


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 95 - 96
1 Feb 2003
Luscombe J Abudu A Pynsent PB Shaylor PJ Carter SR
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About one third of patients who require one knee replacement have significant bilateral symptoms and will require surgery on both knees before achieving their full functional potential. The options for these patients are either to have one-stage bilateral knee replacements or two-stage knee replacements. Our aim was to compare the relative local and systematic morbidity of patients who had one-stage bilateral knee arthroplasty with those of patients who had unilateral total knee arthroplasty in a retrospective, consecutive cohort of patients to evaluate the safety of one-stage bilateral total knee arthroplasty. Seventy-two patients treated with one-stage bilateral knee replacements were matched for age, gender and year of surgery with 144 patients who underwent unilateral knee arthroplasty. We found one-stage bilateral arthroplasty was associated with significantly increased risks of wound infection, deep infection, cardiac complications and respiratory complications compared to unilateral knee arthroplasty.

No increased risk of thromboembolic complications or mortality was found.

We conclude that one-stage bilateral total knee arthroplasty is associated with increased risk of both systematic and local complications compared with unilateral knee replacement and therefore should be performed on only selective cases.


Orthopaedic Proceedings
Vol. 85-B, Issue SUPP_II | Pages 110 - 110
1 Feb 2003
Grimer RJ Davies AM Mehr A Evans N Pynsent PB
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Inadvertent excision of lumps which turn out to be soft tissue sarcomas is still unfortunately quite common. It is known as the “whoops” procedure. Determining whether there is residual disease is key to deciding subsequent management. The value of MRI has been assessed.

All new patients referred to our unit with a potential diagnosis of a “whoops” lesion were routinely reassessed with MR1 6 weeks after the initial operation.

Notwithstanding the result of the scan all patients underwent a further wide excision of the involved area shortly after the MRI. The scans of these patients have been reviewed and classified into positive, equivocal or negative. These results have been compared with the histological assessment of the re- excision specimen to determine the accuracy of MR1 in predicting the presence of residual tumour.

Of 887 patients with newly diagnosed soft tissue sarcomas seen in an 8 year period, 140 (11 %) had previously had a ‘whoops” procedure. Of these 111 had re-evaluation MR1 scans and had also undergone a further re-excision. There was residual tumour in 63 (57%) patients, whilst 48 (43%) had no residual tumour.

The sensitivity of MRI in predicting tumour was 64% but specificity 93%. Positive predictive value was 93% and negative predictive value 67%. Overall accuracy was 77%.

MRI is useful in identifying residual tumour after a whoops procedure but a negative result by no means excludes it. Re-excision remains essential despite the MRI results in most cases to ensure tumour clearance. Preventing the “whoops” procedure is clearly the best option of all!


Orthopaedic Proceedings
Vol. 84-B, Issue SUPP_III | Pages 329 - 329
1 Nov 2002
Disney S Fairbank JCT Pynsent PB
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The Oswestry Disability Index has become one of the major condition specific outcome measures for spinal problems. The original version has been in use since the late 1970’s. It was modified in 1985 by a MRC Working Group. Innumerable papers have cited the ODI and many of these have used the ODI as an outcome. It has been translated into at least five other languages.

The understanding of the validation and behaviour of outcome measures has expanded considerably in the 22 years since the ODI was first published. Many studies have been done on the ODI in conjunction with other spinal outcome measures. This material has now been brought together on a new website (www.merc.wlv.ac.uk/ODI/index.htm). This includes an interactive version of the ODI for self-assessment (which can be downloaded), a large bibliography and frequently asked questions. The site also contains some of the translations and other English versions.