header advert
Results 101 - 120 of 152
Results per page:
Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 25 - 25
1 Mar 2009
Glyn-Jones S Beard D Murray D Gill H
Full Access

Introduction: Interest in hip resurfacing has recently been renewed by the introduction of metal-on-metal designs; it is being increasingly used for young patients, with over 30,000 implanted worldwide. The 5 year clinical results appear promising, but there are no long term data available. Radiostereometry (RSA) measures of implant migration have been able to predict implant failure; specifically large and continuous migration predicts aseptic loosening. We present the results of a five year RSA study examining the migration of the Birmingham Hip Resurfacing (BHR).

Methods: Twenty-four subjects with primary OA were implanted with the BHR device and with bone markers for RSA. RSA measurements were taken at 3, 6, 12, 24 and 60 months. The migration of the head and the tip of femoral component were measured in 3D.

Results: Preliminary analysis showed that the total 3D migration of the head and tip over five years was 0.32mm and 0.23mm respectively.

Discussion: A distal migration of more than 0.4mm over 2 years increases the likelihood of failure in conventional stems. The total migration of the BHR was approximately 0.3mm over a five year period, significantly less than cemented THR devices. The device is stable and this is promising for long-term survival.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 537 - 538
1 Aug 2008
Ganapathi M Jones S Roberts P
Full Access

Aims: The aims of our study were:

to measure the total metal content in cell saver blood recovered during revision hip arthroplasty,

to evaluate the efficacy of centrifuging and washing the recovered blood in reducing the metal content,

to investigate whether transfusion of the salvaged blood resulted in a significant increase in the metal ion levels in the patients’ blood in the immediate post-operative period.

Materials and methods: We analysed the levels of metallic debris and metal ions in cell saver blood in nine patients undergoing revision hip replacement. Using inductively coupled plasma mass spectrometry (ICP-MS), the levels were measured for titanium, aluminium, vanadium, chromium, cobalt, nickel and molybdenum. The metal ion levels were analysed using a dilution technique and the total metal content levels (particulate debris and ions) were analysed with a digestion technique.

Results: Significantly higher levels of metal ions and metal debris were found in the pre-processed blood compared with the processed blood (after centrifuging and washing). The ion levels in the processed blood were not high enough to cause a significant increase in the patients’ immediate post-operative blood ion levels when compared with pre-operative levels.

Discussion: There are markedly elevated levels of metal ions and particulate metal debris in the blood salvaged during revision total hip arthroplasty. The processing of the recovered blood in a commercial “cell saver” significantly reduces the total metal load that is re-infused. Re-infusion of salvaged blood does not result in elevated metal ion levels in the immediate post-operative period.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 546 - 547
1 Aug 2008
Kotwal R Ganapathi M John A Maheson M Jones S
Full Access

Aim: To determine the outcome and need for subsequent surgery in patients following successful closed reduction of dislocation after primary total hip arthroplasty (THA) and the financial implications of re-operation.

Methods: Data was retrospectively obtained from radiographs and patient case notes for all dislocated primary hip replacements presenting to the University Hospital of Wales from January 2000 till November 2005. Records were analysed with a minimum of 1 year follow-up to determine the outcome and need for subsequent surgery following successful closed reduction of dislocation after primary THA. Factors studied include age at primary surgery, indications, components, approach, head size, duration since surgery and direction of dislocation

Results: Over the 6 year study period, 98 patients presented with 100 first time dislocated primary total hip replacements. All the dislocations underwent successful closed reduction. 62 (62%) hips re-dislocated more that once. At minimum follow up of 1 year, 7 patients had died and were excluded from the final study group. Of the remaining 93 hips, 46 patients have had no further surgery. 44 THA’s have undergone revision procedures and 3 are waiting to have revision surgery (51% in total). Of those who have undergone revision surgery, 7 hips re-dislocated since and 3 of those needed further re-revision.

Discussion: Dislocation following primary THA remains a problem with varying dislocation rates quoted in the literature. In our series, 51% of patients presenting with dislocation required revision surgery. All patients in this series had 28 mm or smaller femoral heads. The financial impact of the burden of revision surgery continues to increase. In this series in isolation the cost of revision surgery totalled greater that £500,000.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_III | Pages 534 - 534
1 Aug 2008
Ganapathi M Paul IB Clatworthy E John A Maheson M Jones S
Full Access

Aim: To investigate the outcome following revision total hip arthroplasty (THA) using 36 mm and 40 mm modular femoral heads.

Methods: Details were retrieved from our arthroplasty database regarding all revision THAs done in our unit using 36 mm and 40 mm femoral heads. Follow-up information was obtained from patient records and telephone conversation.

Results: The cohort considered totalled 107 revision THAs, 93 using a 36 mm head and 14 using a 40 mm head. All received either highly cross-linked UHMWPE liners or metal on metal liners. The indications for revisions were recurrent instability in eight, periprosthetic fracture in 11, second stage revision in 24, fracture of the femoral stem in one and aseptic loosening in the remaining 63. At a minimum follow up of one year, information was not available for five but they did not have any record of dislocation. Out of the remaining 102 patients, dislocation occurred in 4 hips (3.9%). None of the revisions done with 40 mm head dislocated. In two of the dislocations, the initial indication for revision THA was recurrent instability and if they are excluded, the dislocation rate was 1.96%.

Discussion: Dislocation and the sequalae of recurrent instability remains a significant problem following revision THA and the existing literature varies greatly in the quoted dislocation rates. We believe that the use of 36 mm and 40 mm femoral heads in our unit has been a major factor in low (3.6%) dislocation rate following revision THA. To date there have been no problems encountered resulting from the use of highly cross-linked UHMWPE.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 7 | Pages 847 - 851
1 Jul 2008
Pandit H Glyn-Jones S McLardy-Smith P Gundle R Whitwell D Gibbons CLM Ostlere S Athanasou N Gill HS Murray DW

We report 17 patients (20 hips) in whom metal-on-metal resurfacing had been performed and who presented with various symptoms and a soft-tissue mass which we termed a pseudotumour. Each patient underwent plain radiography and in some, CT, MRI and ultrasonography were also performed. In addition, histological examination of available samples was undertaken.

All the patients were women and their presentation was variable. The most common symptom was discomfort in the region of the hip. Other symptoms included spontaneous dislocation, nerve palsy, a noticeable mass or a rash. The common histological features were extensive necrosis and lymphocytic infiltration. To date, 13 of the 20 hips have required revision to a conventional hip replacement. Two are awaiting revision.

We estimate that approximately 1% of patients who have a metal-on-metal resurfacing develop a pseudotumour within five years. The cause is unknown and is probably multifactorial. There may be a toxic reaction to an excess of particulate metal wear debris or a hypersensitivity reaction to a normal amount of metal debris. We are concerned that with time the incidence of these pseudotumours may increase. Further investigation is required to define their cause.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 398 - 398
1 Jul 2008
Glyn-Jones S Pandit H Whitwell D Athanasou N Gibbons M
Full Access

Purpose of study: We report the results of a prospective case series of 10 patients who developed tumour-like masses following resurfacing arthroplasty

Method: Ten subjects were referred to the tumour service at the Nuffield Orthopaedic Centre with symptomatic masses around the hip, all had previously received a resurfacing arthroplasty.

We report the clinical, radiographic and histologic features of these cases.

Results: MRI and ultrasound scanning was preformed, which demonstrated masses with solid and cystic components.

Biopsy was performed and subsequent histological examination revealed a profound plasma-cell lymphocytic response associated with metal wear debris.

There were no infections in this series.

Three subjects required revision surgery.

Conclusion: Over 50,000 resurfacing arthroplasties have been implanted worldwide over the past ten years. Although the early clinical results are encouraging little is known about the long term consequences of large head metal on metal bearing surfaces. Despite this, these devices are being widely marketed and are often implanted in younger patients. Resurfacing arthroplasties are associated with high serum and urine metal ion concentrations, metal particles have also been shown to migrate along the lymphatic system. In addition, there is now evidence that high local metal ion concentrations can induce haempoietic cancers.

This study suggests that resurfacing arthoplasty can also induce a local hypersensitivity reaction in response to metal wear debris. It therefore raises new concerns regarding the long-term safety of this procedure.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 381 - 381
1 Jul 2008
Ganapathi M Jones S Roberts P
Full Access

Purpose: The aims of our study were: (i) to measure the total metal content in cell saver blood recovered during revision hip arthroplasty, (ii) to evaluate the efficacy of centrifuging and washing the recovered blood in reducing the metal content, (iii) to investigate whether transfusion of the salvaged blood resulted in a significant increase in the metal ion levels in the patients’ blood in the immediate post-operative period.

Materials and methods: We analysed the levels of metallic debris and metal ions in cell saver blood in nine patients undergoing revision hip replacement. Using inductively coupled plasma mass spectrometry (ICP-MS), the levels were measured for titanium, aluminium, vanadium, chromium, cobalt, nickel and molybdenum. The metal ion levels were analysed using a dilution technique and the total metal content levels (particulate debris and ions) were analysed with a digestion technique.

Results: Significantly higher levels of metal ions and metal debris were found in the pre-processed blood compared with the processed blood (after centrifuging and washing). The ion levels in the processed blood were not high enough to cause a significant increase in the patients’ immediate post-operative blood ion levels when compared with pre-operative levels.

Conclusion: There are markedly elevated levels of metal ions and particulate metal debris in the blood salvaged during revision total hip arthroplasty. The processing of the recovered blood in a commercial ‘cell saver’ sig-nificantly reduces the total metal load that is re-infused. Re-infusion of salvaged blood does not result in elevated metal ion levels in the immediate post-operative period.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 389 - 389
1 Jul 2008
Gorva A Metcalfe J Rajan R Jones S Fernandes J
Full Access

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study.

Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of con-tralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic.

Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). The sensitivity and specificity were 33% and 66% respectively. With positive predictive value of 15% and diagnostic efficiency of 61%.

Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_II | Pages 336 - 336
1 Jul 2008
Gorva A Metcalfe J Rajan R Jones S Fernandes J
Full Access

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study.

Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of con-tralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic.

Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95). The sensitivity and specificity were 33% and 66% respectively. With positive predictive value of 15% and diagnostic efficiency of 61%.

Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required.


The Journal of Bone & Joint Surgery British Volume
Vol. 90-B, Issue 5 | Pages 556 - 561
1 May 2008
Glyn-Jones S McLardy-Smith P Gill HS Murray DW

The creep and wear behaviour of highly cross-linked polyethylene and standard polyethylene liners were examined in a prospective, double-blind randomised, controlled trial using radiostereometric analysis.

We randomised 54 patients to receive hip replacements with either highly cross-linked polyethylene or standard liners and determined the three-dimensional penetration of the liners over three years.

After three years the mean total penetration was 0.35 mm (SD 0.14) for the highly cross-linked polyethylene group and 0.45 mm (SD 0.19) for the standard group. The difference was statistically significant (p = 0.0184). From the pattern of penetration it was possible to discriminate creep from wear. Most (95%) of the creep occurred within six months of implantation and nearly all within the first year. There was no difference in the mean degree of creep between the two types of polyethylene (highly cross-linked polyethylene 0.26 mm, SD 0.17; standard 0.27 mm, SD 0.2; p = 0.83). There was, however, a significant difference (p = 0.012) in the mean wear rate (highly cross-linked polyethylene 0.03 mm/yr, SD 0.06; standard 0.07 mm/yr, SD 0.05). Creep and wear occurred in significantly different directions (p = 0.01); creep was predominantly proximal whereas wear was anterior, proximal and medial.

We conclude that penetration in the first six months is creep-dominated, but after one year virtually all penetration is due to wear. Highly cross-linked polyethylene has a 60% lower rate of wear than standard polyethylene and therefore will probably perform better in the long term.


Orthopaedic Proceedings
Vol. 90-B, Issue SUPP_I | Pages 166 - 166
1 Mar 2008
Hauptfleisch J Glyn-Jones S Gill H McLardy-Smith P Murray D
Full Access

The Charnley Elite femoral component was first introduced in 1992 as a new design variant of the original Charnley femoral component (De Puy, Leeds, UK) with modified neck and stem geometry. The original component had undergone few changes in nearly forty years and has excellent long-term results. Early migration of the new stem design was determined by Roentgen Stereophotogrammetric Analysis (RSA)1. Rapid early migration of a component relative to the bone, measured by RSA, is predictive of subsequent aseptic loosening for a number of femoral stems. As there was rapid early migration and rotation of the Charnley Elite stem, we predicted that the long-term results would be poor. An outcome assessment is indicated as stems of this type are still being implanted.

One hundred Charnley Elite stems, implanted in our centre between 1994 and 1997 were included in a prospective, cross-sectional follow-up study. Outcome measures include validated clinical scores (Charnley hip score, Harris hip score and Oxford hip score) and radiological scores (Gruen classification) as well as revision rates over the past 10 years.

The clinical follow-up supports the RSA predictions of early failure of the Charnley Elite femoral stem.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 436 - 436
1 Oct 2006
Rajan RA Metcalfe J Konstantoulakis C Jones S Sprigg A
Full Access

Introduction: The assessment of bone age using the standard Gruel and Pyle chart based on hand and wrist radiographs is usually carried out by Senior Radiologists. We performed a study to look at both intra and inter observer variability with different grades of clinicians.

Materials and Methods: 30 sets of wrist radiographs were selected at random. The investigators included a Senior Radiographer, a Consultant and Registrar Radiologist an Orthopaedic Consultant and Senior Orthopaedic Fellow.

Discussion: The Radiology team appear to be more consistent in their readings for the assessment of skeletal bone age than the Orthopaedic team. Howevr, it is interesting to note that although the Orthopaedic team are less consistent, when looking at the inter-observer variability, it suggests that both teams are equally well equipped to perform the task.

Conclusion: Our study suggests that we should not cross professional boundaries. Render unto Caeser what is Ceaser’s!


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 436 - 436
1 Oct 2006
Devalia KL Moras P Pagdin J Jones S Fernandes JA
Full Access

Aim of the study: To evaluate the final outcome following joint distraction and reconstruction in patients with complex knee contractures in a select group with varied aetiology.

Materials and methods: Retrospective study of six patients (nine knees, 3 bilateral) with severe knee flexion contractures treated by gradual distraction using ring fixators. Most cases were syndromic or arthrogrypotic.. Case notes and radiographs were reviewed to assess the mobility and functional range of motion before and after the procedure.

Results: Staged procedures was carried out in 6 out of 9 knees accompanied by soft tissue releases, realignment of extensor mechanism and bony and joint realignment. The average age at operation was nine years and nine months and the mean follow up was 53 months. The average time spent in frame was 20 weeks. The correction was graded as good to excellent in 5 knees, fair in 1 and poor in 3 knees. The total arc of motion remained unchanged though the functional range of movement improved. The mobility improved significantly in most patients who were independent walkers with or without splints. Complications were of rebound phenomenon after frame removal in arthrogrypotic children, transient neuropraxia of common peroneal nerve in 2 epiphyseal separation in one and 3 sustained undisplaced fractures during mechanical distraction.

Conclusion: Syndromic and arthrogrypotic knee contractures are difficult to treat due to their severity and complexity. Planned staged procedures with joint distraction, patellar and bony realignment can produce satisfactory outcome in most making them functional independent ambulators.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 368 - 368
1 Oct 2006
Gill H Polgar K Glyn-Jones S McLardy-Smith P Murray D
Full Access

Introduction: The design philosophy of polished tapered THR stems, such as the Exeter, intend for them to migrate distally within the cement mantle. In addition it is likely that micromotion occurs as a result of functional activity. The pattern of induced stresses will be a function of stem geometry & surface finish, as well as applied loading. Aim: To investigate the stresses induced in the cement mantle of a polished tapered THR stem during functional activity.

Method: Using Roentgen Stereophotogrammetric Analysis (RSA) dynamically induced micro-motion (DIMM) was measured in 21 patients implanted with Exeter stems. DIMM was measured as the difference in stem position in going from double to single leg stance on the operated limb. All subjects were measured 3 months post-operatively. A finite element (FE) model of the femur, including all muscles was used to investigate the stress distribution within the cement; contact was modelled with sliding elements allowing separation. The model was validated by comparison to the DIMM measurements.

Results: The Exeter stem demonstrated significant DIMM(p < 0.017), the average motions are given in the table below. The FE model, with sliding contacts was able to predict similar distal migration of the head. The peak minimum principal stress in the mantle was approx 33MPa and occurred in the proximal medial region. Movements occurred at the stem/cement interface.

Discussion and Conclusion: It is possible to measure DIMM in the Exeter stem and combining this with FE modelling the mechanism of stress transfer between the stem and mantle can be investigated in a manner that can be validated.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 436 - 436
1 Oct 2006
Moras P Belthur M Jones S Fernandes J
Full Access

Aim: To report our experience and early results with the Ilizarov pelvic support realignment lengthening osteotomy for complex hip pathology in children.

Material & Methods: Between 1997 & 2004, seven children were treated with this technique and five have completed treatment. The treatment was undertaken for sequelae of DDH in 4 patients and septic arthritis in 1 patient. The median age of the patients was 13(10–17). There were 3 boys and 2 girls. The outcome assessment was performed using the Harris hip score, clinical and radiological parameters.

Results: 4 patients presented with hip instability, shortening of the lower limb, pain and restricted motion. The remaining patient presented with a nonfunctional ankylosis with shortening. The median time between the onset of symptoms and the operation was 3 years (2–5). The median preoperative leg-length discrepancy was 3 cm (2–4.5). The median fixator time was 5 months (3–6). The median follow-up was 24 months (9–72).

Patients had improvement of pain, posture, hip instability, walking ability and limb length discrepancy. The median lengthening of the femur was 3 cm (2–5). The mechanical axis was realigned in all patients. All patients were satisfied with the outcome. Planned secondary contra lateral epiphyseodesis was required to equalise leg length in 2 patients. Complications included a stiff knee (1) that required a Judet quadricepsplasty, premature consolidation (1) that required reosteotomy and knee subluxation (1) that required cross knee stabilisation.

Conclusion: This is a safe and reliable alternative option to joint replacement, Colonna arthroplasty and arthrodesis for the reconstruction of multiply operated complex hip pathology in children.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 436 - 437
1 Oct 2006
Pagdin J McKeown E Madan S Jones S Davies A Bell M Fernandes J Saleh M
Full Access

Purpose: The aim of this part retrospective and part prospective study was to establish the incidence of pinsite infections and assess evolution of changes in practice

Methods: Data was collected retrospectively and prospectively for pin site infections from the inception of limb reconstruction service viz. 1985 to January 2002. There were 812 patients, 1042 limb segments, and 9935 pins. The various external fixators used were limb reconstruction system (LRS) 549; Ilizarov 397; Sheffield ring fixator (SRF); Dynamic axial fixator (DAF) 35; LRS/Sequoia 8; LRS/Garche 7; and Pennig 5.

Results: The pin site infections were graded from 0 to 6 ( Saleh & Scott). There were no infections in 206 segments. The infection grade is shown below:

We changed our pin tract care practice from 1996. We had a significant decrease in pin tract infections since then (p< 0.0001). We also found that using Ilizarov wires had significantly less infections than with half pins used with monolateral fixators (p< 0.0001; linear trend, p= 0.0338). There were 48 patients that required hospital admissions for IV antibiotics. and of these 10 patients required debridement. There were no residual long lasting infections or chronic osteomyelitis.

Conclusion: Attention to detail in insertion of wires and half pins is crucial to avoid pin site infections. This audit supports the fact that external fixation is a safe method from the point of view of infection contrary to general belief.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_III | Pages 434 - 435
1 Oct 2006
Gorva AD Metcalfe J Rajan R Jones S Fernandes JA
Full Access

Introduction: Prophylactic pinning of an asymptomatic hip in SCFE is controversial. Bone age has been used as evidence of future contralateral slip risk and used as an indication for such intervention. The efficacy of bone age assessment at predicting contralateral slip was tested in this study.

Patients and Methods: 18 Caucasian children prospectively had bone age assessment using wrist and hand x-rays when presenting with a unilateral SCFE. Patients and parents were informed about the chance of contralateral slip and risks of prophylactic fixation, and advised to attend hospital immediately on development of symptoms in contralateral hip. After in-situ fixation of the affected side prospective monitoring in outpatient department was performed. Surgical intervention was undertaken if the contralateral hip was symptomatic.

Results: Three children (2 boys) went on to develop to a contralateral slip at a mean of 20 months from initial presentation. 6 children (5 boys) were deemed at risk of contralateral slip due to a bone age below 12.5 years for boys and 10.5 for girls. Only one from this group developed a contralateral slip. The relative risk of proceeding to contralateral slip when the bone age is below the designated values was 1 (95% confidence interval of 0.1118 to 8.95).

Conclusion: Delayed bone age by itself is not a good predictor of future contralateral slip at initial presentation. Routine prophylactic pinning is not justified based on bone age alone, with the risks of surgical fixation it carries. Prospective long term longitudinal study is required.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 45 - 45
1 Mar 2006
Glyn-Jones S Gill R McLardy-Smith P Murray D
Full Access

Introduction Polyethylene wear debris is an important cause of failure in cemented total hip arthroplasty. As a result of the biological response to debris at the bone-cement interface, osteolysis and subsequent failure occurs in both femoral and acetabular components. Most acetabular components and liners are made of ultra high molecular weight polyethylene (UHMWPE). Cross-linking UHMWPE has been shown to significantly reduce abrasive wear in hip simulator studies. The wear rates measured in vitro do not always correlate with the wear rates measured in clinical studies[1]. Some new polyethylenes have shown catastrophic wear in clinical studies despite encouraging hip simulator study results[2]. The aim of this study was to compare the wear of standard UHMWPE to that of cross-linked UHMWPE (Longevity, Zimmer, Warsaw, USA)

Patients and Methods This was a prospective, double blind, randomised control trial. 50 subjects were recruited, all of whom received the cemented CPT stem and uncemented Trilogy liner (Zimmer, UK). Subjects were randomised to receive either a standard Trilogy liner or a Longevity liner at the time of operation. Both liners are identical in appearance. All liners were of a neutral configuration. RSA was used to measure linear wear. This was calculated by measuring the distance between the centre of the femoral head and the centre of the acetabular liner. The preliminary results of the study are presented.

Results Both groups underwent significant wear over two years. The two year linear wear of the cross-linked UHMWPE was 0.3mm (+/− 0.06mm, p< 0.001). The two year linear wear of the standard UHMWPE was 0.39mm (+/− 0.04mm, p< 0.001). No significant difference existed between the two groups (p=0.24). Both cohorts had around 0.15 to 0.2 mm of measured wear per year. Cross-linked UHMWPE therefore underwent less wear than standard UHMWPE at two years, however this difference was not statistically significant.

Discussion This study suggests that Longevity UHMWPE has similar wear properties to standard UHMWPE in the first two years following implantation. This does not correlate with in vitro hip simulator studies of Longevity polyethylene, which show a significantly lower wear rate than standard UHMWPE. It suggests that hip simulator studies may be of little value in predicting in vivo wear rates and that all new types of polyethylene should be evaluated clinically and radiologically prior to general release. Whether both cohorts continue to wear at similar rates will only be revealed through continued observation.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 119 - 119
1 Mar 2006
Johnson P Kurien B Belthur M Jones S Flowers M Fernandes J
Full Access

Aim: To report our experience and early results with flexible nailing for unstable or irreducible displaced proximal humeral fractures in children.

Material & methods: Between 1997 & 2004, 15 children with unstable or irreducible displaced fractures of the proximal humerus were treated with closed/open reduction and flexible IM nailing. There were 10 boys and 5 girls. The median age of the patients was 12.5 years (9–15). Thirteen children had a Salter – Harris II, Neer grade III/IV fracture and 2 children had metaphyseal fractures. The outcome assessment was performed using the shoulder score, clinical and radiological parameters.

Results: All fractures united. None of the patients had a clinically significant malunion/shortening. Three patients had irritation at the nail insertion site. One patient had a transient radial nerve neurapraxia. There were no other operative or postoperative complications. The flexible nails were removed at a median time of 6 months (1.5–10) in 12 patients and 3 patients are awaiting removal. At a median follow-up of 30 months (4–66) all patients had a normal or near normal glenohumeral motion, full strength and all reported regaining full pre-injury functional use of the involved extremity.

Conclusion: Flexible nailing can be used safely to maintain reduction in unstable or irreducible displaced fractures of the proximal humerus and allows early return to normal activities and function with minimal complications. This treatment is also useful in older children who have minimal remodelling potential.


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_I | Pages 35 - 35
1 Mar 2006
Al Hussainy H Jones S Ali F Club S Bostock S
Full Access

Arthroscopic procedures may be associated with considerable pain in the first 24 hours. Intra-articular bupi-vacaine provides good analgesia but is short lasting. Intra-articular morphine has been shown to prolong postoperative analgesia in knee and ankle arthroscopy. The aim of this study is to assess the safety and analgesic effect of intra-articular morphine following day case wrist arthroscopy.

Ethical approval was firstly obtained. 31 patients were randomly assigned to one of 2 groups in a double blind clinical study. Group 1 received 5ml of 0.5% bupi-vacaine intra-articularly with 5mg of morphine subcutaneously. Group 2 received 5ml of 0.5% bupivacaine and 5mg of morphine intra-articularly. There were 15 patients (mean age 41.2 years) in group 1, and 16 patients (mean age 38.9 years) in group 2. Postoperatively pain was assessed using a 100mm visual analogue pain scale (VAPS) at 1, 2, 6 and 24 hours. Analgesia requirements were recorded at these times post operatively. The presence of nausea, vomiting, other complications and patient satisfaction were recorded.

Visual analogue pain scores did not show any significant difference between the groups at 1, 2, 6 and 24 hours. Supplementary analgesic consumption over the 24 hour period was slightly greater in group 1 than in group 2. None of the patients who had intra-articular Morphine had vomiting nor any other complications and did not require anti-emetics. Most patients in either group were satisfied with the level of postoperative analgesia.

Intra-articular bupivacaine with or with out morphine provides adequate postoperative pain relief following wrist arthroscopy. There seems to be little difference between the two methods studied.