Have cementless and resurfacing components improved the medium-term results of hip replacement for patients under 60 years of age?

BACKGROUND AND PURPOSE: The optimal hip replacement for young patients remains unknown. We compared patient-reported outcome measures (PROMs), revision risk, and implant costs over a range of hip replacements. METHODS: We included hip replacements for osteoarthritis in patients under 60 years of age performed between 2003 and 2010 using the commonest brand of cemented, cementless, hybrid, or resurfacing prosthesis (11,622 women and 13,087 men). The reference implant comprised a cemented stem with a conventional polyethylene cemented cup and a standard-sized head (28- or 32-mm). Differences in implant survival were assessed using competing-risks models, adjusted for known prognostic influences. Analysis of covariance was used to assess improvement in PROMs (Oxford hip score (OHS) and EQ5D index) in 2014 linked procedures. RESULTS: In males, PROMs and implant survival were similar across all types of implants. In females, revision was statistically significantly higher in hard-bearing and/or small-stem cementless implants (hazard ratio (HR) = 4) and resurfacings (small head sizes (< 48 mm): HR = 6; large head sizes (≥ 48 mm): HR = 5) when compared to the reference cemented implant. In component combinations with equivalent survival, women reported significantly greater improvements in OHS with hybrid implants (22, p = 0.006) and cementless implants (21, p = 0.03) (reference, 18), but similar EQ5D index. For men and women, National Health Service (NHS) costs were lowest with the reference implant and highest with a hard-bearing cementless replacement. INTERPRETATION: In young women, hybrids offer a balance of good early functional improvement and low revision risk. Fully cementless and resurfacing components are more costly and do not provide any additional benefit for younger patients.

No functional benefit of larger femoral heads and alternative bearings at 6 months following primary hip replacement.

BACKGROUND AND PURPOSE: There has been a recent trend towards the use of greater femoral head sizes in an attempt to improve function and enhance stability after primary hip replacement. This has been associated with the use of alternative bearings, theoretically to reduce wear and improve implant longevity. METHODS: We examined the influence of these variables on patient-reported outcome measures (PROMs) for a consecutive series of primary hip replacements using National Joint Registry (NJR) and PROMs-linked data. To minimize the confounding influence of implant design factors, the single most commonly used brand in England and Wales (DePuy Corail Pinnacle) was examined. Improvement in patient hip-specific outcomes (Oxford hip score, OHS), general health outcomes (Euroqol, EQ-5D), and rates of self-reported complications (bleeding, wound problems, re-admission, and reoperation) were compared for different head sizes (28-mm, 32-mm, and 36-mm) and bearings (metal-on-polyethylene (MoP), ceramic-on-polyethylene (CoP), and ceramic-on-ceramic (CoC)), adjusting for differences in case mix. RESULTS: At a mean follow-up of 7 months, improvements in OHS and EQ5D index were similar for 28-mm and 36-mm heads. A 32-mm head was associated with poorer function (OHS: 20, 99% CI: 19-21, p = 0.002; EQ5D index: 0.39, 99% CI: 0.36-0.42, p = 0.004), although these small differences may not be of clinical importance. There were no statistically significant benefits of either CoP or CoC bearings compared to a MoP bearing. Complication rates were similar within comparisons of head sizes or bearings. INTERPRETATION: In this short-term study, we did not find any functional benefits of larger head sizes or alternative bearings, after adjusting for other influences. We question their use in routine primary hip replacement given the lack of evidence of improved long-term survival in the literature.

The effect of triclosan coated sutures on rate of surgical site infection after hip and knee replacement: a protocol for a double-blind randomised controlled trial.

BACKGROUND: 187,000 hip and knee joint replacements are performed every year in the National Health Service (NHS). One of the commonest complications is surgical site infection (SSI), and this represents a significant burden in terms of patient morbidity, mortality and cost to health services around the world. The aim of this randomised controlled trial (RCT) is to determine if the addition of triclosan coated sutures to a standard regimen can reduce the rate of SSI after total knee replacement (TKR) and total hip replacement (THR). METHODS: 2400 patients due to undergo a total hip or knee replacement are being recruited into this two-centre RCT. Participants are recruited before surgery and randomised to either standard care or intervention group. Participants, outcome assessors and statistician are blind to treatment allocation throughout the study. The intervention consists of triclosan coated sutures vs. standard non-coated sutures. The primary outcome is the Health protection Agency (HPA) defined superficial surgical site infection at 30 days. Secondary outcomes include HPA defined deep surgical site infection at 12 months, length of hospital stay, critical care stay, and payer costs. DISCUSSION: To date there are no orthopaedic randomised controlled trials on this scale assessing the effectiveness of a surgical intervention, particularly those that can be translated across the surgical specialities. The results from this trial will inform evidence-based recommendations for suture selection in the management of patients undergoing total hip or knee replacement. If triclosan coated sutures are found to be an effective intervention, implementation into clinical practice could improve long-term outcomes for patients undergoing hip and knee replacement. TRIAL REGISTRATION: Current Controlled Trials ISRCTN 17807356.

The effect of high dose antibiotic impregnated cement on rate of surgical site infection after hip hemiarthroplasty for fractured neck of femur: a protocol for a double-blind quasi randomised controlled trial.

BACKGROUND: Mortality following hip hemiarthroplasty is in the range of 10-40% in the first year, with much attributed to post-operative complications. One such complication is surgical site infection (SSI), which at the start of this trial affected 4.68% of patients in the UK having this operation. Compared to SSI rates of elective hip surgery, at less than 1%, this figure is elevated. The aim of this quasi randomised controlled trial (RCT) is to determine if high dose antibiotic impregnated cement can reduce the SSI in patients at 12-months after hemiarthroplasty for intracapsular fractured neck of femur. METHODS: 848 patients with an intracapsular fractured neck of femur requiring a hip hemiarthroplasty are been recruited into this two-centre double-blind quasi RCT. Participants were recruited before surgery and quasi randomised to standard care or intervention group. Participants, statistician and outcome assessors were blind to treatment allocation throughout the study. The intervention consisted of high dose antibiotic impregnated cement consisting of 1 gram Clindamycin and 1 gram of Gentamicin. The primary outcome is Health Protection Agency (HPA) defined deep surgical site infection at 12 months. Secondary outcomes include HPA defined superficial surgical site infection at 30 days, 30 and 90-day mortality, length of hospital stay, critical care stay, and complications. DISCUSSION: Large randomised controlled trials assessing the effectiveness of a surgical intervention are uncommon, particularly in the speciality of orthopaedics. The results from this trial will inform evidence-based recommendations for antibiotic impregnated cement in the management of patients with a fractured neck of femur undergoing a hip hemiarthroplasty. If high dose antibiotic impregnated cement is found to be an effective intervention, implementation into clinical practice could improve long-term outcomes for patients undergoing hip hemiarthroplasty. TRIAL REGISTRATION: Current Controlled Trials: ISRCTN25633145.

Factors influencing revision risk following 15 740 single-brand hybrid hip arthroplasties: a cohort study from a National Joint Registry.

This retrospective cohort study of a National Joint Registry data examines survival time to revision following the commonest brand of primary hybrid THA, exploring risk factors independently associated with failure. Overall 5-year revision was 1.56%. In the final adjusted model, revision risk was significantly higher with standard polyethylene (PE) liners (metal-on-PE: hazard ratio [HR]=2.52, P=0.005, ceramic-on-PE: HR=2.99, P=0.025) when compared to metal-on-highly-cross-linked (XL) PE. Risk of revision with ceramic-on-ceramic bearings was borderline significant (HR=1.86, P=0.061). A significant interaction between age and acetabular shell type (solid or multi-hole) was found (P=0.022), suggesting that solid shells performed significantly better in younger patients. In summary, we found that there were significant differences in implant failure between different bearing surfaces and shell types after adjusting for a range of covariates.

Conventional Versus Highly Cross-Linked Polyethylene in Primary Total Knee Replacement: A Comparison of Revision Rates Using Data from the National Joint Registry for England, Wales, and Northern Ireland.

BACKGROUND: There is evidence to support the use of highly cross-linked polyethylene (HXLPE) in patients undergoing total hip arthroplasty. However, the benefits for those undergoing total knee arthroplasty are uncertain, with conflicting reports based on previous cohort analyses. The purpose of the present study was to compare the revision rates following primary total knee arthroplasty with use of HXLPE as compared with conventional polyethylene (CPE) using data from the National Joint Registry (NJR) for England, Wales and Northern Ireland. METHODS: We performed a retrospective analysis of primary total knee arthroplasties recorded in the NJR from 2003 to 2014. Cobalt-chromium (CoCr)-CPE and CoCr-HXLPE bearing surfaces were compared using all-cause revision, aseptic revision, and septic revision as end points. Survival analyses were conducted using rates per 100 years observed, Kaplan-Meier survival estimates, and Cox regression hazard ratios (HRs) adjusted for age, sex, American Society of Anesthesiologists (ASA) classification, body mass index (BMI), lead surgeon grade, and implant constraint. Secondary analyses compared the most commonly used HXLPEs (Zimmer Prolong, DePuy XLK, and Stryker X3) against CPE for the 3 most common total knee arthroplasty systems (NexGen, PFC Sigma, and Triathlon). RESULTS: In the present study of 550,658 total knee arthroplasties, the unadjusted aseptic revision rates were significantly lower following procedures performed with CPE (n = 513,744) as compared with those performed with HXLPE total knee replacements (n = 36,914) (0.29 [95% confidence interval (CI), 0.28 to 0.30] compared to 0.38 [95% CI, 0.35 to 0.42], p < 0.01). The 10-year HR associated with CPE was 0.4 (95% CI, 0.1 to 0.8, p = 0.03). There were no significant differences between the adjusted revision rates of HXPLE compared with CPE in individual analyses of the most common total knee arthroplasty systems. However, for the subset of patients who were both <60 years of age and had a BMI of >35 kg/m, the "second-generation" Stryker X3 HXLPE demonstrated significantly better survival than its respective CPE, with CPE having an HR of 2.6 (95% CI, 1.2 to 5.9) (p = 0.02). CONCLUSIONS: Alternative bearings are marketed as having improved wear properties over traditional CoCr-CPE. This registry-based analysis demonstrated no overall survival benefit of HXLPE after a maximum duration of follow-up of 12 years. Because of their increased cost, the routine use of HXLPE bearings may not be justified. However, they may have a role in specific "higher demand" groups such as patients <60 years of age and/or those with a BMI of >35 kg/m. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete list of levels of evidence.

Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales.

BACKGROUND: Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis. METHODS AND FINDINGS: Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing); the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs), costs and risk of repeat (revision) surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index) (9159 linked episodes) and competing risks modelling of implant survival (79,775 procedures). Cost of implants and ancillary equipment were obtained from National Health Service procurement data. RESULTS: EQ5D score improvements (at 6 months) were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001), when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001) for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003) and resurfacing implants, HR = 3.46, p<0.001), with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524) and highest with cementless implants (£1928 to £4285). Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long-term implant survival data (reflecting the duration of data collection), the possibility of revision under-reporting, response bias within PROMs data, and issues associated with current outcome scoring systems, which may not accurately reflect level of improvement in some patients. CONCLUSIONS: Cement fixation, using a polyethylene cup and a standard sized head offers good outcomes, with the lowest risks and at the lowest costs. The most commonly used cementless and resurfacing implants were associated with higher risk of revision and were more costly, while perceptions of improved function and longevity were unsupported.

Cemented versus cementless hemiarthroplasty for intracapsular neck of femur fracture--a comparison of 60,848 matched patients using national data.

National guidelines recommend cemented hemiarthroplasty for intracapsular fractured neck of femur (NOF), based on evidence of less pain, better mobility and lower costs. We aimed to compare complications following cemented and cementless implants, using the national hospital episode statistics (HES) database in England. Dislocation, revision, return to theatre and medical complications were extracted for all patients with NOF fracture who underwent hemiarthroplasty between January 2005 and December 2008. To make a 'like for like' comparison all 30,424 patients with a cementless implant were matched to 30,424 cemented implants (from a total of 42,838) in terms of age, sex and Charlson co-morbidity score. In the cementless group, 18-month revision (1.62% versus 0.57% (OR 2.90, p<0.001)), 4-year revision (2.45% versus 1.11% (OR 2.28, p<0.001)) and 30-day chest infection (8.14% versus 7.23% (OR 1.14, p=0.028)) were significantly higher. Four-year dislocation rate was higher in cemented implants (0.60% versus 0.26% (OR 0.45, p<0.001)). No significant differences were seen in return to theatre or other medical complications. In this national analysis of matched patients mid-term revision and perioperative chest infection was significantly higher in the cementless group. This supports the published evidence and national guidelines recommending cement fixation of hemiarthroplasty.