Is patient satisfaction related to patient reported sounds from ceramic on ceramic total hip arthroplasty? A study of 265 hips.

INTRODUCTION: The ideal method and implant to perform total hip arthroplasty (THA) is still a debated topic. Ceramic on ceramic (CoC) bearings have favourable wear properties, but squeaking has been reported as an unwanted side effect. We aimed to determine the rate of noise generation from CoC hips and investigate whether there is a relationship with patient satisfaction. METHODS: A total of 246 consecutive CoC bearing uncemented THA were retrospectively identified in a single institution. Post-operatively patients were sent a postal questionnaire to evaluate their reported sounds and satisfaction with their THA. Uni- and multi-variate analyses were performed to identify potential predictor variables for reported post-operative sounds. RESULTS: Questionnaires were returned by 172 patients (70% return rate). 24% reported sounds from their hips with 11% reporting a squeak. Median satisfaction levels were minimally, but significantly less for "noisy" (9/10) than "quiet" hips (10/10) (median difference = - 1, 95% CI - 2 to 0, p < 0.001). Compared to those with "noisy" hips, patients with "quiet" hips were 1.7 times (95% CI 1.3-2.5, p = 0.0002) more likely to report a "forgotten" hip. Younger age (p < 0.043) and increased anteversion (p < 0.021) were predictors for reported sounds. CONCLUSION: We have identified a high rate of "noisy" hips in this series of CoC THA with a significant inverse relationship between "noisy" hips and patient satisfaction levels. In our unit, we are moving towards the use of ceramic on cross-linked polyethylene bearings as a result of these findings and the excellent survivorship of this bearing combination.

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.

Failure rates of stemmed metal-on-metal hip replacements: analysis of data from the National Joint Registry of England and Wales.

BACKGROUND: Total hip replacement (THR) is extremely common. Some prostheses fail, particularly in younger patients, and need to be revised, most commonly for loosening secondary to wear or dislocation. Surgeons have tried to address these problems by implanting large diameter metal-on-metal bearing surfaces. Our aim was to assess if metal-on-metal bearing surfaces lead to increased implant survival compared with other bearing surfaces in stemmed THR and, additionally, if larger head sizes result in improved implant survival. METHODS: We analysed the National Joint Registry of England and Wales for primary hip replacements (402,051, of which 31,171 were stemmed metal-on-metal) undertaken between 2003 and 2011. Our analysis was with a multivariable flexible parametric survival model to estimate the covariate-adjusted cumulative incidence of revision adjusting for the competing risk of death. FINDINGS: Metal-on-metal THR failed at high rates. Failure was related to head size, with larger heads failing earlier (3·2% cumulative incidence of revision [95% CI 2·5-4·1] for 28 mm and 5·1% [4·2-6·2] for 52 mm head at 5 years in men aged 60 years). 5 year revision rates in younger women were 6·1% (5·2-7·2) for 46 mm metal-on-metal compared with 1·6% (1·3-2·1) for 28 mm metal-on-polyethylene. By contrast, for ceramic-on-ceramic articulations larger head sizes were associated with improved survival (5 year revision rate of 3·3% [2·6-4·1] with 28 mm and 2·0% [1·5-2·7] with 40 mm for men aged 60 years). INTERPRETATION: Metal-on-metal stemmed articulations give poor implant survival compared with other options and should not be implanted. All patients with these bearings should be carefully monitored, particularly young women implanted with large diameter heads. Since large diameter ceramic-on-ceramic bearings seem to do well we support their continued use. FUNDING: National Joint Registry of England and Wales.

Early results of a high friction surface coated uncemented socket in revision hip arthroplasty.

BACKGROUND: Revision hip arthroplasty with high friction trabecular metal sockets has resulted in good medium-term results. Many manufacturers have therefore introduced higher friction coatings to their implants to meet a growing demand for similar implants. The Pinnacle Gription was introduced in 2007 as an evolution of the standard Pinnacle socket. This study aimed to assess the early results of this socket in a revision setting. METHODS: Between August 2009 and December 2016, the Gription socket was used in 146 revision hip replacements. The mean age was 63 (19-88) years. Defects were classified as Paprosky Grade 2 in 71(2A [28], 2B [19], 2C [24]) and grade 3 in 20 (3A [18], 3B [2]). Bearing combinations were ceramic-on-ceramic in 23, metal-on-polyethylene in 71, ceramic-on-polyethylene in 52. Screws were used in 112 cases, impaction bone grafting in 34 and metal augments in 1 case. Radiographs were analysed for progressive radiolucent lines and migration. RESULTS: Mean follow-up was 43.5 (range 25-62) months. There were 6 re-revisions (2 for deep infection, 2 for recurrent dislocation and 2 for aseptic loosening). None of the other cases had evidence of socket migration or progressive radiolucent lines. There were no intraoperative or postoperative periprosthetic fractures. The crude survivorship for all-cause failure was 95.8% and the survivorship for aseptic loosening was 98.6%. at 43.5 months follow-up. CONCLUSIONS: This is the largest reported series of Gription socket use in revision arthroplasty and demonstrates encouraging early results. We therefore advocate the continued cautious use of this implant.

Evolution of cemented stems.

John Charnley was responsible for pioneering successful cemented hip arthroplasty. Changes in stem design were made in response to early complications such as stem fracture. Various philosophies of stem biomechanics emerged, namely stems performing in the taper slip mode and stems performing as a composite beam. Both stem designs may be successful, although it is important not to mix biomechanical philosophies. Later evolutions have occurred in response to surgical flexibility, specifically modularity and offset options. These attributes can impart new demands on the stem and, in some cases, retrograde developments have occurred. Cemented stems may yield excellent long-term results and have the potential to limit fixation to the proximal femur and establish a metaphyseal-loading regimen. The latest design of taper slip stems, such as the C-stem (DePuy Orthopaedics, Warsaw, Ind), may have advantages in maintaining proximal bone stock and preserving host bone. The historical developments and evolution of the cemented stem in total hip arthroplasty (THA) are discussed.

A study of the effect of tibial tray rotation on a specific mobile bearing total knee arthroplasty.

We presumed that a particular mobile-bearing knee prosthesis would cope with tibial tray rotation about its longitudinal axis. We studied the tibiofemoral and patellofemoral joints to assess this. The prosthesis was mounted on a specially designed jig. The tray was externally rotated in 5 degrees increments and put through a range of flexion. We found that increasing tibial tray rotation caused excessive polyethylene loading and, eventually, medial femoral component liftoff. The patellofemoral joint showed increasing lateral patella facet contact. Surprisingly, this mobile-bearing prosthesis could not cope with tibial tray rotation. It required the tibial tray to be neutrally aligned to the femoral component to avoid excessive polyethylene loading.