Analysis of the Risk of Wear on Cemented and Uncemented Polyethylene Liners According to Different Variables in Hip Arthroplasty

Early unrestricted vs. partial weight bearing after uncemented total hip arthroplasty: a systematic review and meta-analysis

Background

The choice of postoperative weight bearing protocol after uncemented total hip arthroplasty (THA) remains controversial. The aim of this study was to assess the efficacy and safety of immediate unrestricted weight bearing (UWB) compared with partial weight bearing (PWB) in patients undergoing uncemented THA.

Methods

Relevant articles were retrieved from electronic databases. Both randomized controlled trials (RCTs) and non-RCTs were included but analyzed separately. All functional and clinical outcomes with at least 2 independent study outcomes were meta-analyzed.

Results

A total of 17 studies were investigated. No adverse effect was found regarding micromotion of the femoral stem with immediate UWB following uncemented THA. There was also no correlation between immediate UWB and failure of ingrowth fixation and higher risks of femoral stem subsidence and surgical revision in RCTs. Harris hip score was better in patients with immediate UWB than those with PWB at 1 year post surgery, but the difference was not statistically significant.

Conclusions

Immediate UWB did not have extra harm compared with PWB in patients undergoing uncemented THA. UWB was not superior to PWB. Considering the improvement of Harris score and the compliance of patients, UWB can be encouraged in THA rehabilitation.

Unexpected Repercussions of the COVID-19 Pandemic on Total Hip Arthroplasty with Cemented Hip Prosthesis versus Cementless Implants

(1) Background: Total hip arthroplasty (THA) is one of the most common procedures used for adult hip reconstruction, employing mainly two types of prostheses: cemented (CHP) and cementless (CLHP). This study aims to analyze the impact of the COVID-19 pandemic on THA with CHP and CLHP, in terms of the benefit/cost ratio. (2) Methods: This article represents a retrospective analysis of the differences concerning the benefit/cost ratio between THA with the two types of prostheses in 2950 patients admitted for THA in the two orthopedic clinics of our hospital between 1 January 2015-1 March 2020 in comparison with 1005 THA subjects seen between 1 April 2020-31 December 2022. (3) Results: In the first period, THA with CHP was performed in 45.83% of cases, while CLHP was used in 54.16% of patients. During the COVID-19 period, CHP was inserted in 52% of THA patients, while the other 48% had CLHP inserted, with a hospitalization duration reduced by over 50% for both types of implants (p ˂ 0.001). (4) Conclusions: CHP offered good outcomes, with quicker mobilization, and shorter hospitalization duration, compared to CLHP, but optimization of the patients' management can be achieved mainly by reducing the length of hospitalization through an appropriate preoperative patient evaluation through a multidisciplinary approach, an aspect that was proven during the COVID-19 pandemic.

In Silico Contact Pressure of Metal-on-Metal Total Hip Implant with Different Materials Subjected to Gait Loading

The use of material for implant bearing has a vital role in minimizing failures that endanger implant recipients. Evaluation of contact pressure of bearing material can be the basis for material selection and have correlations with wear that contribute to the need of revision operations. The current paper aims to investigate three different metallic materials, namely cobalt chromium molybdenum (CoCrMo), stainless steel 316L (SS 316L), and titanium alloy (Ti6Al4V) for application in metal-on-metal bearing of total hip implant in terms of contact pressure. In silico model based on finite element simulation has been considered to predict contact pressure of metal-on-metal bearings under normal walking conditions. It is found that the use of Ti6Al-4V-on-Ti6Al4V is superior in its ability to reduce contact pressure by more than 35% compared to the other studied metal-on-metal couple bearings.

Reliability and Validity of Standing Lateral Radiograph Method for Measuring Acetabular Component Version: A Modified Cross-table Lateral Radiograph Method

OBJECTIVES

To investigate the effect of the X-ray incidence angle on cup version measurements and the reliability and validity of standing lateral (SL) radiography for measuring cup versions.

METHODS

Cup versions under different X-ray incidence angles were investigated by the 3D simulation analysis. Ninety-three patients, who underwent primary total hip arthroplasty (THA) with postoperative SL radiographs and CT scans between April 2020 and December 2021, were retrospectively analyzed. SL radiography was taken under naturally standing position, correcting for the measurement error of pelvic tilt in cross-table lateral (CL) radiography. Cup versions were measured on SL radiographs and CT images by two qualified orthopedic physicians. The intra- and inter-observer reliabilities were assessed by intra-class correlation coefficient. The consistency between radiographic and CT measurements was evaluated using Pearson correlation coefficient.

RESULTS

No significant differences in cup version measurements were observed between groups of different X-ray incidence angles (P = 0.663) in the 3D simulation analysis. All measurements had excellent intra- and inter-observer reliabilities, with an intraclass correlation coefficient of >0.95. Mean cup version measurements from SL radiographs correlated well with those from CT scans (r = 0.853, P < 0.001). The mean difference between radiographic and CT measurements was -0.49° (range -12.62° to 10.37°, SD 3.95°), and the majority of differences were within the 95% limits of agreement.

CONCLUSION

The cup versions measured with SL radiography were close to the CT measurements. SL radiograph method is reliable and valid for measuring acetabular component version after THA.