Mid-Term Survival of Total Hip Arthroplasty in Patients Younger Than 55-year-old

RM Pressfit vitamys: the 10-year follow-up

INTRODUCTION

The RM Pressfit vitamys is an uncemented, titanium particle-coated, isoelastic monoblock cup made of vitamin E blended highly cross-linked polyethylene. We addressed the following questions: (1) What are the clinical and (2) radiographic outcomes 10 years after implantation? (3) What is the revision rate?

METHODS

In this prospective observational study in a tertiary care centre we investigated all consecutive cases of total hip replacement with the RM Pressfit vitamys cup between September 2009 and November 2011. It was implanted in 162 hips, 49.4% in women. The mean age was 67.2 years (standard deviation [SD] 9.5), and the mean BMI was 27.3 kg/m2 (SD 4.7). In 153 cases (94.4%), primary or secondary osteoarthritis was the diagnosis. We evaluated preoperative and follow-up data at 6 weeks, 1, 5, and 10 years. A modified Harris Hip Score (mHHS), pain and satisfaction on a visual analogue scale (VAS), radiographic evaluation, complications and revision rate were investigated.

RESULTS

At the 10-year follow-up (mean 120.5 months, SD 1.4, range 118-126), 99 hips were available for clinical and radiographic evaluation. (1) The mean mHHS was 94.8 (SD 9.9), rest pain 0.2 (SD 0.6), load pain 0.5 (SD 1.5), and satisfaction 9.5 (SD 1.1). The mean improvement as compared to preoperatively was +33.7 (SD 16.8), -3.3 (SD 2.7), -6.0 (SD 2.4) and +5.7 (SD 2.5), respectively. (2) In the radiographic evaluation, no loose cups, no acetabular lucent lines, or acetabular osteolysis were seen. (3) 2 cups were revised, both due to malpositioning. The 10-year cumulative revision rate was 2.0% (95%CI, 0.0-4.2%). The implant survival rate with aseptic loosening as endpoint was 100%. No adverse events were reported.

CONCLUSIONS

At the 10-year follow-up, the RM Pressfit vitamys cup still had promising results with good clinical and radiographic outcomes and a low revision rate.

Risk factors for residual pelvic obliquity one year after total hip arthroplasty

PURPOSE

It is not uncommon for patients with hip disorders to present with pelvic obliquity (PO), and residual PO after total hip arthroplasty (THA) may not only affect hip joint function but also cause adjacent intervertebral joint disorders. This study aimed to investigate the postoperative PO impact on clinical outcomes and risk factors by comparing patients who had PO after THA to those who did not.

METHODS

A single-center, retrospective cohort study was conducted. A total of 103 patients who underwent THA were included in this study from 2018 to 2020. Demographics, functional outcomes, and spinopelvic parameters were compared between post-THA PO of less than 2° (NT group, 55 patients) and PO of 2° or more (O group, 48 patients). Multivariate analysis was performed using factors with significant differences in univariate analysis.

RESULTS

Postoperative Harris Hip Score Activity was significantly lower in the T group than in the NT group (p = 0.031). Preoperative PO was smaller in the NT group than in the T group (p = 0.001). Preoperative lumbar bending range (LBR) was significantly more flexible in the NT group than in the T group. In the logistic regression analysis, Age (odds ratio 0.957, 95% CI 0.923-0.993, p = 0.020), preoperative PO (odds ratio 1.490, 95% CI 1.100-2.020, p = 0.001), and LBR (odds ratio 0.848, 95% CI 0.756-0.951, p = 0.005) were found to be significant factors.

CONCLUSION

Younger age and large preoperative PO, and poor lumbar spine mobility were identified as risk factors for residual postoperative PO.

Extreme Serum Titanium Concentration Induced by Acetabular Cup Failure: Unveiling a Unique Scenario of Titanium Alloy Debris Accumulation

The majority of contemporary total hip arthroplasty (THA) implants are constructed from Ti alloys, which are generally believed to generate fewer adverse local tissue reactions (ALTRs) compared to CoCr alloys. This study presents a case of unusual primary THA failure where a substantial release of Ti alloy debris was observed. A 52-year-old active male underwent THA after post-traumatic aseptic necrosis of the femoral head in 2006. Seventeen years after the procedure, the patient presented with groin pain and a restricted range of motion. X-rays revealed the protrusion of the alumina ceramic head through the Ti6Al4V acetabular cup. Trace element analysis indicated significantly elevated levels of serum Ti, Al, and V. CT and MRI confirmed Ti alloy cup failure and a severe ALTR. During revision surgery, it was found that the worn-out ceramic head was in direct contact with the acetabular cup, having protruded through a central hole it had created over time. No acetabular liner was found. Histological analysis of his tissue samples showed wear-induced synovitis with areas of multinucleated foreign body giant cells and the accumulation of numerous metal particles but no acute inflammatory response. Six months after the revision THA, the patient has experienced favourable outcomes. This case provides an instructive illustration for studying the consequences of the substantial release of Ti alloy debris from orthopedic implants.

Analysis of the natural collapse course of non-traumatic osteonecrosis of the femoral head based on the matrix model

BACKGROUND

There are many predictions about the progression of natural collapse course of osteonecrosis of the femoral head. Here, we aimed to combine the three classical prediction methods to explore the progression of the natural collapse course.

METHODS

This retrospective study included 127 patients admitted to our hospital from October 2016 to October 2017, in whom the femoral head had not collapsed. Logistic regression analysis was performed to determine the collapse risk factors, and Kaplan-Meier survival curves were used for femoral head survival analysis. The collapse rate of the femoral head was recorded within 5 years based on the matrix model. The specificity of the matrix model was analyzed using the receiver operating characteristic curve.

RESULTS

A total of 127 patients with a total of 202 hips were included in this study, and 98 hips collapsed during the follow-up period. Multivariate logistics regression analysis showed that the predictive ability of the matrix model was stronger than Association Research Circulation Osseous staging, Japanese Investigation Committee classification, and area (P < 0.05). Kaplan-Meier survival curve showed that the median survival time of femoral head in patients was 3 years. The result of the receiver operating characteristic curve analysis showed that the area under the curve (AUC) of the matrix model had better predictive value (AUC = 0.771, log-rank test: P < 0.001).

CONCLUSION

We creatively combined the three classical prediction methods for evaluating the progression of the natural collapse course based on the matrix model and found that the higher the score of the matrix model, the higher the femoral head collapse rate. Specifically, the matrix model has a potential value in predicting femoral head collapse and guiding treatment selection.

In Vivo Performance of Vitamin E Stabilized Polyethylene Implants for Total Hip Arthroplasty: A Review

BACKGROUND

Vitamin E stabilization was introduced to improve the oxidative stability, wear resistance, and mechanical properties of highly crosslinked polyethylene (HXLPE). In this literature review, we asked: (1) How has vitamin E-stabilized HXLPE (VEPE) performed in vivo for total hip arthroplasty (THA) and how does it compare with conventional ultra-high molecular weight polyethylene (UHMWPE) and HXLPE without vitamin E; and (2) Is there an apparent difference in the clinical performance of VEPE created by blending versus diffusion?

METHODS

We performed a systematic search of the literature according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines using PubMed and Embase. Included studies reported the in vivo behavior of VEPE in THA. We reviewed 41 studies.

RESULTS

For all studies that compared polyethylene with and without VE stabilization, outcomes for VEPE were either equivalent or superior to the control group (for HXLPE without VE and conventional UHMWPE controls, respectively). Hip insert wear rates were generally less than 0.1 mm/year and in most cases were less than 0.05 mm/year. No VEPE components were revised for osteolysis or adverse outcomes specific to VE incorporation.

CONCLUSION

Across the literature, we found that VEPE was reported to be clinically effective for THA applications, with much of the research indicating positive clinical outcomes and lower or equivalent wear rates compared to conventional UHMWPE and HXLPE controls without VE. Instances of early component fracture were reported, but have multiple potential causes. There is a gap in the literature for comparison of blended and diffused components, so the in vivo impact of VE incorporation method remains to be seen. Overall, this study provides a comprehensive summary of VEPE clinical performance for THA and may serve as a resource for future investigations.