Introduction

Adverse reaction to metal debris (ARMD) is an increasingly recognised complication of metal-on-metal hip arthroplasty. A previous study described poor results following revision and recommended early intervention¹. We determined the outcome of revision for ARMD and present the largest case series to date.

Background: There is a paucity of published data with regard to the wear of failed metal on metal (MoM) resurfacing devices.

Materials and Methods: MoM components retrieved from patients from two independent centres experiencing failure secondary to ARMD were analysed using a Mitutoyo Legex 322 coordinate measuring machine (CMM) which has an accuracy of 0.8 microns. Between 4000 – 6000 points were taken on each explant, dependent on the size of the bearing surface. Maximum wear depths and total volumetric wear were calculated. These values were compared to those from control samples retrieved following uncomplicated fractures/femoral collapse secondary to avascular necrosis (after calculating equivalent yearly wear rates).

Results: 58 ARMD components were analysed. This included 22 36mm MoM THRs (DePuy Pinnacle), 28 DePuy ASRs and 8 Zimmer Duroms. There were 30 resurfacing fracture/avascular necrosis controls. Volumetric wear rates and maximum wear depths of ARMD resurfacing components were significantly greater than the resurfacing control group for both the ASR and Duroms (p< 0.05) however 2 ARMD components exhibited similar amounts of wear compared to controls. Wear rates of the ARMD THR group were significantly lower than the ARMD resurfacing group (p< 0.05).

Conclusions: Increased articular wear is associated with an increased incidence of local adverse effects including tissue necrosis, joint effusions and fractures. However, there are a minority of patients who can develop tissue necrosis in the absence of accelerated wear, implying a spectrum of sensitivity This is reflected in the incidence of ARMD in the patient groups at the main study centre: > 5% in the ASR group and approx 1% in the THR group. We believe this indicates a failure of adequate lubrication and the resultant negative effects in larger bearing devices.

Introduction: Today’s aging population has resulted in an increase in the number of major orthopaedic surgical interventions in the elderly. Total knee replacement (TKR) is one of the commonest operations in orthopaedic practice. The fourth annual report of the National Joint Registry showed that there were 60 986 TKR performed in England and Wales in 2006. The true figure is probably much higher. Literature showed that 20–70% of patients who had TKR needed 1–3 units of blood.

Although safer than ever, allogeneic transfusion is still associated with risks for the recipient (haemolysis, infection, immunosuppression, transfusion-related acute lung injury and even death).

Tranexamic acid (TA) is a synthetic antifibrinolytic agent that has been successfully used to stop bleeding after dental operation, removal of tonsils, prostate surgery, heavy menstrual bleeding, eye injuries and in patients with Haemophilia.

In this study Tranexamic acid was applied topically to the exposed tissue around the knee joint prior to the wound closure and tourniquet release. It is anticipated that this method of administration is quick, easy, associated with less systemic side effect. Also, it provides a higher concentration of the Tranexamic acid at the bleeding site.

Objectives: To find out whether Tranexamic acid can reduce blood loss and subsequent blood transfusion significantly after total knee replacement when applied topically without extra side effects.

Design: A double blind randomised controlled trial of 150 patients who underwent unilateral primary cemented total knee replacement. This number gives a 90% power to detect a 50% reduction in blood loss and 80% power to detect a reduction in blood transfusion from current local standard 30% to 10%.

Outcome Measures: Blood loss, transfusion, Length of stay, complications, Euroqol and Oxford Knee Score.

Results: The two groups were comparable in age, weight, height, BMI, Tourniquet time, and type of anaesthesia. There has been significant differences in the amount of blood loss and blood transfusion in favour of tranexamic acid (p-values are 0.001 and 0.007 respectively). Fourteen patients needed blood transfusion ranged from 2–6 units. Thirteen were in the Placebo group and only one in the Tranexamic acid. There has been no significant difference among other outcomes in particular complications rates such as DVT and pulmonary embolism.

In our independent centre, in the period from January 2003 to august 2008, over 1100 36mm MoM THRs have been implanted as well as 155 Birmingham Hip Resurfacing procedures, 402 ASR resurfacings and 75 THRs using ASR XL heads on SROM stems.

During this period we have experienced a number of failures with patients complaining of worsening groin pain at varying lengths of time post operatively. Aspiration of the hip joints yielded a large sterile effusion on each occasion. At revision, there were copious amounts of green grey fluid with varying degrees of necrosis. There were 11 failures of this nature in patients with ASR implants (10 females) and 2 in the 36 MoM THR group (one male one female).

Tissue specimens from revision surgery showed varying degrees of ‘ALVAL’ as well as consistently high numbers of histiocytes. Metal debris was also a common finding.

A fuller examination of our ASR cohort as a whole has shown that smaller components placed with inclinations > 45° and anteversions < 10 or > 20° are associated with increased metal ion levels. The 11 ASR failed joints were all sub optimally positioned (by the above definition), small components.

Explant analysis using a coordinate measuring machine and out of roundness device confirmed greater than expected wear of each component. The lower number of failures in the 36mm MoM group, as well as the equal sex incidence, suggests that the majority of these failures are due to the instigation of an immune reaction by large amounts of wear debris rather than adverse reactions to well functioning joints. It is likely that small malpositioned ASRs function in mixed to boundary lubrication, and this, combined with the larger radius of these joints compared to the 36mm MoM joints, results in more rapid wear.

Introduction: There are ongoing concerns regarding metal wear debris following the use of metal-on-metal (MonM) bearings for hip surface and total arthroplasty. A Type IV Hypersensitivity reaction to MonM articulations has previously been identified (aseptic lymphocyte dominated vasculitis associated lesion, ALVAL) but little is known of its incidence, diagnosis or management. Persisting groin pain in MonM patients may be undiagnosed ALVAL. At our single centre we have reviewed and compared three types of MonM articulations to examine the incidence of ALVAL and to identify trends.

Methods: The resurfacing group comprised 250 patients with the ASR prosthesis. In the resurfacing hybrid total hip replacement (THR) group there were 86 patients implanted with an ASR head on a stem. The final group comprised of 625 patients with a MonM THR using a 36mm Pinnacle head. Both the S-ROM and the Corail stems were used in the THR groups. Patients with persisting and activity-restricting groin pain had tests for infection. Patients were counselled and revision was offered if ALVAL was suspected from the clinical picture, blood results and the aspiration result. Specimens for microbiological and histological analysis were taken at the time of revision.

Results: We found 5 cases of histologically proven ALVAL in the absence of infection in 961 patients. The incidence was: 1.2% in the resurfacing group, 2.3% of Resurfacing Hybrid THR group and 0 in the 36 mm THR group. All 5 cases were in female patients. Only 1 case had any radiological abnormality. One patient was initially revised from a resurfacing to a 36mm MonM THR without clinical success. All patients have now been revised to ceramic-on-ceramic bearings with improvements in outcome.

Discussion: ALVAL may be under-diagnosed. The 5 patients we describe showed good clinical recovery following their primary procedure. However, activity levels decreased and pain increased at 6–12 months post-op. All described non-specific systemic symptoms. On examination, a painful straight leg raise was a characteristic finding. This may result from the significant effusion found around the hip at each revision. Fluid aspirated from these hips was of a characteristic colour (green grey) and viscosity. The failure of the revision of a resurfacing to a smaller MonM bearing highlights the problem of sensitisation to the metal debris. Any subsequent revision to a MonM bearing is unlikely to improve clinical outcome. This finding is consistent with previous reports in the literature. Our results suggest the incidence of ALVAL may be higher that previously thought. We suggest all patients with significant groin pain should have inflammatory markers tests and a hip aspiration performed. In the absence of infection, revision to an alternative bearing surface may be indicated.

Introduction: Potential problems resulting from metal-on-metal hip wear debris are well known. Previous studies have shown an association between high cup angles and raised metal ion levels, but a link to clinical outcome has yet to be established. We aim to show the relationship between high cup angles, raised metal ion levels and pain following hip resurfacing.

Methods: This analysis comprised the first 250 Depuy ASR hip resurfacings performed by a single surgeon (senior author) over a 3 yr period at an independent centre. Patients were followed up, examined and x-rayed at regular intervals. We measured Harris Hip Score (HHS) and pain. The acetabular cup inclination angles were measured from standardised pelvic radiographs. A subgroup of 80 patients had serum and whole blood chromium and cobalt measurements performed. This subgroup comprised patients with a similar sex split, age, activity level, follow-up and cup angle profile to the parent group.

Results: HHS improved from 51.6 pre-operatively to 94.6 post-operatively. Males had a significantly higher post-op HHS (97.1) compared with the females (91.0). 2.1% of male patients had pain compared with 8.7% of females. High cup angles were associated with pain in females. This relationship did not occur in males. In patients with cup angles of 48° and above there were no males with pain compared to 15.4% of females. Females under 48° had a HHS of 93.7 compared to 88.0 for those over 48°. When we analysed metal ion levels there was a similar relationship. Patients with cup angles of 48° and above had significantly higher serum and whole blood chromium and cobalt levels compared with lower cup angles. Three patients with cup angles over 50° developed ALVAL (aseptic lymphocyte dominated vasculitis associated lesion) based on histological findings. All were female.

Discussion: High cup angles are associated with increased pain and elevated metal ion levels. Women seem to be more intolerant of an higher cup angle than men. This may be a consequence of the smaller prostheses in females. Cups implanted lower than 48° had a better clinical outcome and less metal ion wear. Like other 4th generation designs, the ASR cup is not a complete hemisphere (unlike the BHR) and may be susceptible to edge loading at lower inclination angles than previously thought. We believe the current recommendation of 45° +/−5° is too high based on our findings. We recommend an inclination angle that does not exceed 48°.

Introduction: Pain after total hip arthroplasty (THA) can be caused by infection, aseptic loosening, heterotopic ossification, and referred pain. Psoas tendonitis is a rare cause of groin pain after THA and resurfacing arthroplasty. It is believed to be caused by psoas tendon impingement against a malpositioned acetabular component due to defective anteversion or centring and the use of oversized cups. We report 4 cases of psoas tendonitis following resurfacing arthroplasty and hybrid surface arthroplasty.

Methods: Between April 2004 and June 2005, we diagnosed 4 cases (3 female and 1 male) of psoas tendonitis among 152 cases of resurfacing arthroplasty and hybrid surface arthroplasty (2.6%). 116 patients had a hip resurfacing with ASR prosthesis (2 cases, 1.7%) and 36 patients had hybrid surface arthroplasty with ASR unipolar head on S ROM stem (2 cases, 5.6%). All these patients presented 2–5 months postoperatively with severe groin pain which was exaggerated when moving from the sitting position to the upright position and when going up stairs. Common causes of pain after hip arthroplasty, infection and loosening were ruled out. Radiological and ultrasound examination were performed.

Results: Ultrasound examination revealed thickening of psoas tendon in all cases and fluid collection around the tendon in one case. All cases were treated with corticosteroid injection under ultrasound guidance. Significant but temporary symptomatic relief was achieved in all cases.

Discussion: Psoas tendonitis should be considered in the differential diagnosis of groin pain after hip resurfacing procedures. Ultrasound examination is the initial investigation of choice and corticosteroid injection around the tendon is initial method of treatment. Computerized tomography and surgical options of management should be considered in resistant cases.

Introduction: Design of the prosthesis is an important factor in the successful outcome and longevity of total hip replacement. The purpose of the present study is to evaluate the minimum six-year results of primary total hip replacement using LX cemented prosthesis.

Methods: We prospectively studied 177 patients (60 male and 117 female) who underwent 197 hip replacements, between 1996 and 1999, using LX cemented prosthesis comprising a femoral component with cylindrical cross section of the stem and an acetabular component of ultrahigh molecular weight polyethylene. The average follow up was 7.3 years (6.1–9.6years). Clinical (Harris Hip Score) and radiological assessments (Barrack’s grading of cementation, subsidence, debonding, radiolucent lines and osteolysis) were performed.

Results: The average Harris Hip Score is 85.53 (28–99) compared to the preoperative score of 59.28. 28 cases (14.2%) developed progressive radiolucent lines around the stem. Sinking and debonding of the stem was noted in 18 cases (9.1%). 15 hips (7.6%) have dislocated and 11 were recurrent dislocations. Revision hip replacement was carried out in 12 cases (6%) for subsidence and debonding of stem, cement fracture and recurrent dislocation. The femoral stem components were found to be loose at the time of surgery.

Discussion: We believe that design of the prosthesis is an important factor in the high incidence of subsidence and debonding of the femoral stem. Both the geometry (cylindrical shape) and the rough surface finish (Ra value 100 microinches) were responsible for the pattern of progressive loosening. Lack of progressive increase in the offset with increase in the size of femoral component from 1 to 2 is one of the factors which contributed to high incidence of dislocation.

Introduction: Experimental studies in anatomic full size hip models indicate that larger femoral heads offer potential in providing greater hip range of motion and joint stability. We studied the effects of increasing head diameter from 28mm to 36 mm in total hip replacement (THR) on the range of flexion and abduction.

Methods: 243 patients who underwent primary total hip replacement with S ROM prosthesis between July 1996 and June 2004 were studied. 151 patients (77 male and 74 female) underwent THR with 28 mm head and 92 patients (38 male and 54 female) underwent THR with 36 mm head. The range of flexion and abduction were studied and statistical analysis was performed using the Student t-test. We monitored the dislocation rate in both groups.

Results: The mean flexion is 87.0 for the 28 mm group and 89.6 for the 36 mm group. The mean abduction is 27.77 and 27.98 for 28mm and 36mm groups respectively. Even though there is a slight increase in the mean flexion and abduction from the 28mm to 36mm group, this increase in not found to be statistically significant. For flexion (2.6 (−0.85 to 3.2); p=0.377), and for abduction (0.02 (−2.37 to 1.94); p=0.847). Three hips dislocated in the 28mm group (2%) but none of the hips in 36mm group has dislocated.

Discussion: Even though experimental studies indicate improvement in range of motion with increasing head diameter in THR, this effect is not reflected in our clinical study. But there is improvement in the joint stability by using a prosthesis with larger head diameter as evidenced by a reduction in the dislocation rate.

Introduction: The distorted anatomy in Developmental Dysplasia of the Hip (DDH) makes a total hip arthroplasty (THA) a challenging procedure. The purpose of the current study is to report the midterm results after uncemented primary hip arthroplasty using S ROM prosthesis in a prospective series of patients with hip dysplasia.

Methods: We performed 22 uncemented total hip replacements using S ROM prosthesis in 21 (12 female and 9 male) patients with hip dysplasia. The means age at the time of hip surgery was 41.8 (22 to 64) years. The mean follow-up was 6.3 (3.8 to 9.6) years. In 9 (40.9%) patients the operative treatment of DDH was performed during the early childhood (femoral osteotomy in 6 and pelvic osteotomy in 3). All patients were evaluated clinically and radiologically. The femoral head displacement prior to THA surgery was classified according to Crowe at al. classification (4 hips were type1, 2 type2, 10 type3 and 6 type 4).

Results: The average Harris Hip Score improved from 29.48 to 72.76 (44 to 99) and the average Oxford hip score is 31.22 (12 to 47). The range of flexion is 60°–120° (average 83.23) and abduction is 10°–40°(average 22.94). None of the hips has dislocated. Radiolucent lines were noted around the femoral stem in one case. None of the cases have developed osteolysis around femoral prosthesis. In one patient (4.5%), revision hip surgery was done for aseptic loosening of cemented acetabular cup.

Discussion: The midterm results of total hip replacement in DDH using S ROM uncemented prosthesis are promising. We recommend this modular prosthesis for hip replacement in dysplastic hips.

Introduction: Revision total hip replacement has high rates of failure which appears to be due, in part, to deficient bone stock that does not provide an adequate environment for fixation of the implant. Cementless modular implant offers the possibility of restoration of bone stock in conjunction with adequate fixation, thus re-establishing the function of the hip without the use of additional cement. This study reviews patients treated with the S-ROM system, assessing clinical outcomes, implant stability and osseous response to the hip revisions.

Methods: Sixty two cementless revision hip arthroplasties were performed using the S-ROM prosthesis between 1996 and 2001. Fifty four were available for follow up evaluation at 3 to 8 years (median 4.5 years). Radiological analysis, patient satisfaction and Harris hip scores were assessed pre and post operatively then at average of 4.5 years later.

Results: Eighty-five percent of patients were satisfied with the result of surgery. Clinical scores improved from a preoperative value 34 to 80 points post-operatively and were maintained on further assessment at average of 4.5 years. Forty-three stems had solid bony ingrowth, nine had mild subsidence initially averaged 6.4 mm then stabilized. Two had marked initial subsidence, which also later stabilised. There was gradual filling of the osteolytic defects in 32 of the 37 (86.5%) femoral lesions.

Discussion: With improvement of the postoperative hip score by more than 50 points and absence of definite implant instability at the final follow up, the results of use of S-ROM prosthesis in the revision cases of this study seems to be successful. The follow up is relatively short, but the experience derived from this work confirms the versatility of the S-ROM prosthesis in the complex hip revision situations as well as its favourable mechanical and biologic impact on the adjacent osseous structures.