Bone cement in total hip arthroplasty - Is it really green?

BACKGROUND: Total hip replacement (THR)is typically cemented, cementless or hybrid depending on patient factors and surgeon preference. To date no studies have evaluated waste generated with each of these procedures in relation to implant choice, and particularly waste related to consumables. We aimed to quantify the volume; type and ability to recycle this waste and suggest potential strategies for reducing the overall waste related to consumables in THR. METHOD: This was a prospective review of all waste related to consumables in THR. The waste was weighed using a Salter 1066 BKDR15 scale, accurate to the nearest 1 â€‹g. The primary outcome was the amount of waste generated per case depending on implant choice (cemented vs. uncemented). Secondary outcomes included: proportion of clinical waste and proportion of recyclable waste. RESULTS: Cemented THR generated a total of 1.89 â€‹kg of waste compared to 775 â€‹g for an uncemented THR. Cemented THR generated significantly more sterile (hazardous) waste than uncemented THR both as overall volume and as a proportion 763 â€‹g (40%) vs 76 â€‹g (10%). Significantly more of the waste related to uncemented THR was amenable to being recycled through conventional waste streams with simple changes in theatre 672 â€‹g (86%) compared to 989 â€‹g (52%) with cemented THR. Between 20 and 30% of waste packaging for both types of surgery compromised information booklets. CONCLUSION: Cemented hip replacement generates significantly more waste from consumables than uncemented and a greater amount of this waste is hazardous requiring intensive processing. For both implants a significant proportion of waste can be recycled with simple process changes in theatre. Industry partners have a responsibility to minimise unnecessary packaging and work with surgeons to improve sustainability.

Post-operative complications following total hip arthroplasty for trauma: A multicentre cohort study comparing dual mobility with conventional acetabular bearings.

Aims: Dislocation of a total hip replacement is a serious complication after total hip arthroplasty (THA). Dislocation rates are higher when surgery is performed following trauma. Our study compares post-operative dislocation rates between conventional acetabular bearing (CAB) and dual mobility acetabular bearing (DMB) THA performed for neck of femur fracture alongside post-operative periprosthetic fracture, revision and mortality. Methods: A retrospective multicentre cohort study at 9 hospital trusts in the United Kingdom of all THA performed for neck of femur fracture between March 2018 and February 2019. Results: A total of 295 operations were performed. 64% (189) were CAB and 36% (106) were DMB. Average age was 75 years (38-98). 223 Female: 72 Male. The follow-up period was an average of 42 months (36-48). Overall revision rate was 1.6%,8 peri-prosthetic fracture rate was 6 (2%) and overall mortality was 9.8% (29) with no significant difference between cohorts for any outcome. The posterior approach (PA) was favoured 82% (242) vs the lateral approach (LA) 18% (53) with the PA used more often in patients undergoing DMB 96% (102) vs CAB 74% (140) p = 0.001. Patients approached posteriorly at the time of their index procedure were significantly less likely to sustain a simple dislocation following a DMB 0 (0%) vs. CAB 8 (5.7%) p = 0.015. Conclusion: Our study demonstrates that the risk of dislocation following THA for trauma is more than four times higher than when conventional bearings are used compared to dual mobility acetabular components. This effect is most pronounced when the PA is utilised for the index procedure. The use of these bearings does not impact mortality, peri-prosthetic fracture or revision rate. We would encourage the use of dual mobility acetabular bearings in patients undergoing THA for fracture via a PA.

Is dual mobility cup total hip replacement associated with increased incidence of heterotopic ossification compared to conventional total hip replacements in fracture neck of femur patients?

INTRODUCTION: The incidence of heterotopic ossification after total hip replacement is variable in the literature. If symptomatic, it may cause pain and reduced range of motion. Dual mobility total hip replacements have been considered a valuable option for the treatment of femoral neck fractures in the active patients, achieving good range of motion with reduced risk of dislocation. The occurrence of HO may have detrimental effect on this type of articulation and may accelerate polyethylene wear and predispose to intra-prosthetic dislocation. We compared the incidence of HO in DMC versus conventional THR in femoral neck fracture patients across 3 large trauma institutes PATIENTS AND METHODS: This is a retrospective cohort study which included 334 patients, 223 received DMC replacements, 111 received conventional total hip replacement (THR). Mean age for the DMC group was 72.3 ± 9.9 years and was 72.1 ± 6.8 years for the THR group. Patients were stratified according to specific inclusion and exclusion criteria, and the 1-year follow up X rays were evaluated for the presence of heterotopic ossification by 3 assessors. RESULTS: The incidence of HO in the DMC group was 27.1% compared to 12.2% in the THR group (χ2 p value = 0.0001, Relative Risk = 2.22, 95% CI 1.22-4.03, p value = 0.0091). There was no significant effect of gender or age on the incidence of HO in both groups CONCLUSIONS: Patients receiving DMC hip replacements are more likely to develop HO as compared to patients receiving conventional THR for femoral neck fractures. Further prospective studies are required to confirm our findings and to assess the indication of HO prophylaxis in patients receiving DMC hip replacements, and the long-term outcomes in these patients.

Acetabular revision using a dual mobility cup as treatment for dislocation in Charnley total hip arthroplasty.

AIMS: Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD). METHODS: A retrospective review of patients treated with either a DMC or PLAD for dislocation in patients with a Charnley THA was performed. They were identified using electronic patient records (EPR). EPR data and radiographs were evaluated to determine operating time, length of stay, and the incidence of complications and recurrent dislocation postoperatively. RESULTS: A total of 28 patients underwent revision using a DMC for dislocation following Charnley THA between 2013 and 2017. The rate of recurrent dislocation and overall complications were compared with those of a previous series of 54 patients who underwent revision for dislocation using a PLAD, between 2007 and 2013. There was no statistically significant difference in the mean distribution of sex or age between the groups. The mean operating time was 71 mins (45 to 113) for DMCs and 43 mins (21 to 84) for PLADs (p = 0.001). There were no redislocations or revisions in the DMC group at a mean follow-up of 55 months (21 to 76), compared with our previous series of PLAD which had a redislocation rate of 16% (n = 9) and an overall revision rate of 25% (n = 14, p = 0.001) at a mean follow-up of 86 months (45 to 128). CONCLUSION: These results indicate that DMC outperforms PLAD as a treatment for dislocation in patients with a Charnley THA. This should therefore be the preferred form of treatment for these patients despite a slightly longer operating time. Work is currently ongoing to review outcomes of DMC over a longer follow-up period. PLAD should be used with caution in this patient group with preference given to acetabular revision to DMC. Cite this article: Bone Joint J 2020;102-B(4):423-425.

Outcomes for cemented dual mobility cup to treat recurrent instability; A UK case series.

OBJECTIVES: Recurrent dislocation of Total Hip Replacement (THR) is often multifactorial and remains a significant surgical challenge with a significant risk of further instability. Dual Mobility Cups (DMC) have been used widely with good long term results in France with few studies in the British literature, especially assessing their use for recurrent instability. We set out to assess whether recurrent instability can be successfully treated solely with revision of acetabular component to a dual mobility cup. METHODS: We retrospectively reviewed a prospectively collected electronic database for all consecutive dual mobility cups implanted to address recurrently instability in THR. Radiological and clinical data have been analysed. RESULTS: From September 2013 to September 2017 54 dual mobility cups have been implanted, mean age 78 (range 49-97). 47 were 1st time revision procedures, 7 were following previous revisions including 5 failed PLADs. Average time post primary was 10 years (range 8 months-23 years). Twenty cases are cement in cement revisions which has become our primary technique for revision of cemented cups. Mean follow up is 1.9 years (range 6 months-5 years), 37 cases have 2 year follow up available. 8 patients have died. There have been no episodes of further instability. One patient has had reoperation for infection (1st stage revision). CONCLUSIONS: This series demonstrates satisfactory early to mid-term results for the use of dual mobility cups to treat recurrent instability. The technique is particularly useful when femoral components are well fixed and can be used with monoblock implants such as the Charnley stem. Cement in cement revision is a convenient technique and potentially reduces complications and cost. Further analysis of longer term data is required but these results suggests this could be a valid solution to a complex problem.

Preliminary results of an uncemented trabecular metal tibial component in total knee arthroplasty.

Trabecular metal has several theoretical advantages for the long-term survival of a tibial component. We report the results of a prospective cohort of 105 consecutive primary total knee arthroplasties using an uncemented trabecular metal (tantalum) tibial component at a minimum 3-year follow-up (range, 36-56 months). There was a significant improvement in Oxford Knee scores and Short Form-12 scores postoperatively. There was no radiolucency at the implant-bone interface on any postoperative radiograph. There has been one (1%) revision of the tibial component for trauma. The 3-year results using this prosthesis are as good as those published for the commonly used cemented prostheses. Longer follow-up is required to see whether these results are maintained over time.