Aims

The aim of our study was to investigate the effect of asymmetric crosslinked polyethylene liner use on the risk of revision of cementless and hybrid total hip arthroplasties (THAs).

Our previous work presented at BHS revealed a reduced risk of revision for all reasons in THAs using lipped (asymmetric) liners. Some audience members felt that this finding may be due to unaccounted confounders and the hip surgery community remains sceptical.

A fully adjusted Cox model was built after exploratory Kaplan-Meier analyses. The following surgical approaches were included in the analysis: Posterior, Hardinge/anterolateral, Other. The variables included in the final Cox model included: Gender, liner asymmetry, age, head composition, stem fixation method, head diameter, indication for implantation and surgical approach. An additional analysis of the 3 most commonly used polyethylene liners with both a flat and asymmetric version was performed.

In the fully adjusted Cox model, the use of a flat liner was associated with increased risk of revision for instability (HR: 1.79, 95%CI: 1.52–2.10) and increased risk of revision for all reasons (HR 1.195, 95%CI: 1.104 – 1.293) when compared to THAs utilising flat liners. This finding was upheld in the product specific analysis.

When utilising flat liners, the Hardinge/anterolateral approach was associated with a reduced risk of revision for instability compared to the posterior approach (HR 0.56, 95%CI: 0.446 to 0.706). When an asymmetric liner was used, there was no significant difference in the risk of revision for instability between the Hardinge/anterolateral approach and the posterior approach (HR 0.838, 95%CI: 0.633 – 1.110).

The use of polyethylene-based bearings gives the surgeon the option to use asymmetric liners. The reduced risk of revision in THAs with asymmetric liners was seen in the analysis of the complete dataset and in the product specific analysis. Our results demonstrate that the posterior approach, when used with asymmetric XLPE liners, is not associated with a higher risk of revision for instability as historical data suggested.

Patients ≤ 55 years have a high primary TKA revision rate compared to patients >55 years. Guided motion knee devices are commonly used in younger patients yet outcomes remain unknown. In this sub-group analysis of a large multicenter study, 254 TKAs with a second-generation guided motion knee implant were performed between 2011–2017 in 202 patients ≤ 55 years at seven US and three European sites. Revision rates were compared with Australian Joint Registry (AOANJRR) 2017 data. Average age 49.7 (range 18–54); 56.4% females; average BMI 34 kg/m2; 67.1% obese; patellae resurfaced in 98.4%. Average follow-up 4.2 years; longest follow-up six years; 27.5% followed-up for ≥ five years. Of eight revisions: total revision (one), tibial plate replacements (three), tibial insert exchanges (four). One tibial plate revision re-revised to total revision. Revision indications were mechanical loosening (n=2), infection (n=3), peri-prosthetic fracture (n=1), and instability (n=2). The Kaplan-Meier revision estimate was 3.4% (95% C.I. 1.7% to 6.7%) at five years compared to AOANJRR rate of 6.9%. There was no differential risk by sex. The revision rate of the second-generation guided motion knee system is lower in younger patients compared to registry controls.

Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown. 1,684 consecutive patients underwent 2,059 primary TKAs with a second-generation guided motion implant between 2011–2017 at three European and seven US sites. Of 2,003 (97.3%) TKAs in 1,644 patients with BMI data: average age 64.5 years; 58.4% females; average BMI 32.5 kg/m2; 13.4% had BMI ≥ 40 kg/m2. Subjects with BMI ≥ 40 kg/m2 had longest length of hospital stay (LOS) at European sites; LOS similar at US sites. Subjects with BMI ≥ 40 kg/m2 (P=0.0349) had longest surgery duration. BMI ≥ 40 kg/m2 had more re-hospitalizations or post-TKA reoperations than BMI < 40 kg/m2 (12.7% and 9.2% at five-year post-TKA, P<0.0495). Surgery duration and long-term complication rates are higher in patients with BMI ≥ 40 kg/m2, but device revision risk is not elevated.

Aims

To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs).

Aim

To assess the effect of different polyethylene modifications on Total Hip Replacement survival.

Aim

To assess the effect of the bearing surface and head size on the survival of total hip replacements with modern bearing surface combinations.

Introduction

Patients ≤ 55 years have a high primary TKA revision rate compared to patients >55 years. Guided motion knee devices are commonly used in younger patients yet outcomes remain unknown.

Introduction/Aim

Outcomes for guided motion primary total knee arthroplasty (TKA) in obese patients are unknown.

Background

The JOURNEY™ II Cruciate-Retaining Total Knee System (JIICR) and the JOURNEY™ II Bi-Cruciate Stabilized Total Knee System (JIIBCS) (both, Smith & Nephew, Memphis, TN, USA) are used for the treatment of end-stage degenerative knee arthritis. Belonging to the JOURNEY family of knee implants, the relatively new devices are designed to provide guided motion. Studies suggest that long-term outcomes of robotic-assisted navigation in total knee arthroplasty (TKA) are superior to the classical approach. This is the first report describing early postoperative outcomes of the NAVIO® robotic-assisted surgical navigation using the JOURNEY™ II family of knee implants.

Aims

The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA).

Objectives: An evidence-based trauma database that rated the level-of-evidence for the majority of orthopedic trauma literature would be useful to orthopedic trauma surgeons and researchers. Currently, the development of a database using evidence ratings for such a large body of literature is a time-consuming and expensive endeavor. However, if an accurate rating could be obtained from an abstract without reading the full text, such an endeavor would be feasible. Thus, the purpose of this study is to determine if a reviewer can successfully ascertain the level-of-evidence from the article’s abstract without reading the full text article.

Methods: We compared the level-of-evidence rating obtained from reading an article’s full text with the rating obtained from reading the abstract alone. We reviewed 162 clinical articles published from January 2000 through April 2004 in five orthopedic trauma journals. To establish a full text rating, two reviewers independently rated the full text of each article for study type (therapeutic, prognostic or diagnostic) and level-of-evidence (I through V). The ratings from the two reviewers were compared and disagreements were reconciled through discussion to form a final full text rating. A third reviewer rated the abstracts of each article without access to the full text or full text rating.

Results: Of the 162 articles, 118 (73%) were therapeutic, 40 (25%) were prognostic and 4 (3%) were diagnostic. Most studies represented level IV evidence (65%), with only 15% representing the highest level-of-evidence, level I. Kappa values for agreement between the two reviewers rating the full text were 0.81 for study type and 0.79 for level-of-evidence, and the kappa values for agreement between the final full text rating and the abstract rating were 0.68 for study type and 0.75 for level-of-evidence, respectively. Thirteen of the discordant abstracts (8% of the entire set) lacked sufficient or correct evidence compared with the full text to render an accurate rating.

Conclusion: Accurate study type and level-of-evidence rating in trauma articles can be obtained in most orthopedic trauma articles from reading an article’s abstract alone. Thus, developing an evidence-based trauma database that uses abstracts to rate the level-of-evidence of the orthopedic trauma literature appears feasible and appropriate.

This research was supported by a grant from the AO Foundation, Clinical Investigation and Documentation, Clavadelerstrasse, 7270 Davos Platz, Switzerland