Survivorship and Patient-Reported Outcomes of an Uncemented Vitamin E-Infused Monoblock Acetabular Cup: A Multicenter Prospective Cohort Study

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.

Ten-year clinical and radiological outcomes with a vitamin E-infused highly cross-linked polyethylene acetabular cup

Aims

Limited implant survival due to aseptic cup loosening is most commonly responsible for revision total hip arthroplasty (THA). Advances in implant designs and materials have been crucial in addressing those challenges. Vitamin E-infused highly cross-linked polyethylene (VEPE) promises strong wear resistance, high oxidative stability, and superior mechanical strength. Although VEPE monoblock cups have shown good mid-term performance and excellent wear patterns, long-term results remain unclear. This study evaluated migration and wear patterns and clinical and radiological outcomes at a minimum of ten years' follow-up.

Methods

This prospective observational study investigated 101 cases of primary THA over a mean duration of 129 months (120 to 149). At last follow-up, 57 cases with complete clinical and radiological outcomes were evaluated. In all cases, the acetabular component comprised an uncemented titanium particle-coated VEPE monoblock cup. Patients were assessed clinically and radiologically using the Harris Hip Score, visual analogue scale (pain and satisfaction), and an anteroposterior radiograph. Cup migration and polyethylene wear were measured using Einzel-Bild-Röntgen-Analyze software. All complications and associated treatments were documented until final follow-up.

Results

Clinical assessment showed persistent major improvement in all scores. On radiological assessment, only one case showed a lucent line (without symptoms). At last follow-up, wear and migration were below the critical thresholds. No cup-related revisions were needed, indicating an outstanding survival rate of 100%.

Conclusion

Isoelastic VEPE cups offer high success rates and may prevent osteolysis, aseptic loosening, and the need for revision surgeries in the long term. However, longer follow-up is needed to validate our findings and confirm the advantages offered by this cup.

Bone support correlation of X-Ray and CT for a new PE-glenoid

INTRODUCTION

The radiographic evaluation of novel cementless anatomic polyethylene (PE) glenoid components featuring a titanium-coated back is still unclear. This study explores potential radiolucent lines (RLL) between the radiopaque titanium layer and sclerotic convex reamed bone in an intermodal comparison analysis with computed tomography (CT) scans.

MATERIALS AND METHODS

Eight RM pressfit vitamys glenoids (Mathys®) were implanted into cadaveric scapulae. In the CT scans, glenoids were quantified by evaluating ideal complete bony support (NO GAP) and gap between bone and titanium coating (GAP). X-rays were in perfect 0-degree projection and tilted in ± 10° and ± 20° mediolateral (ml) and craniocaudal (cc) directions. Radiographs evaluated were graded as NO RLL, RLL (gap > 1 mm) or DL (double line, gap < 1 mm) in an intermodal comparison of CT and X-ray findings.

RESULTS

The inter-rater (Cohen's = 0.643) and intra-rater reliability (Cohen's = 0.714) were good. The overall evaluation showed a significant agreement between (NO) RLL on X-ray and (NO) GAP on CT (p < 0.001). The - 10-degree ml projection showed good agreement between CT and X-ray (Cohen's = 0.628). Adequate agreement was shown at 0 degrees (Cohen's = 0.386), + 10 degrees ml (Cohen's = 0.338), and + 20 degrees cc (Cohen's = 0.327). Compared to the scenario DL = NO RLL, the true a.p. view showed better sensitivity when the DL is classified as RLL. Conversely, the true a.p. view demonstrated both better specificity and significant agreement between the X-ray and CT findings in scenario when DL = No RLL.

CONCLUSION

Standard true a. p. projections are reliable in ruling out gaps when no RLL or DL is visible and the detection of RLL shows high intermodal agreement. Varying agreement across tilting angles emphasizes the importance of a comprehensive approach in evaluating bone support and CT is indispensable for a scientifically reliable assessment.

LEVEL OF EVIDENCE

Level III Treatment Study.

An isoelastic monoblock cup versus a modular metal-back cup: a matched-pair analysis of clinical and radiological results using Einzel-Bild-Röntgen-Analyse software

INTRODUCTION

Bone preservation and long-term survival are the main challenges in cementless total hip arthroplasty (THA). A good bone stock is especially important for adequate anchorage of the cup in revision cases. However, the optimal acetabular cup design for preserving good bone stock is still unclear. We aimed to compare clinical outcome, radiological alterations, migration, and wear at mid-term for two different cup types.

MATERIALS AND METHODS

This retrospective matched-pair study was performed using the data for 98 THA cases treated with a monoblock cup composed of vitamin E-blended highly cross-linked polyethylene (VEPE; monoblock group) or a modular cup composed of a highly cross-linked polyethylene (HXLPE) without an antioxidant (modular group). Clinical results were evaluated using the Harris Hip Score (HHS). The obtained radiographs were analyzed for radiological alterations, migration, and wear using Einzel-Bild-Röntgen-Analyse (EBRA) software.

RESULTS

The mean follow-up duration was 73.2 ± 19.2 months (range: 32-108 months) and 60.5 ± 12.2 months (range: 20-84 months) in the monoblock and modular groups, respectively. HHS improved to 95.7 points in the monoblock group and 97.6 points in the modular group, without significant differences (p = 0.425). EBRA measurements were obtained in all cases. Acetabular bone alterations were not detected on radiological assessments. Mean cup migration was 1.67 ± 0.92 mm (range: 0.46-3.94 mm) and 1.24 ± 0.87 mm (range: 0.22-3.62 mm) in the monoblock and modular groups. The mean wear rate was 0.21 ± 0.18 mm (range: 0.00-0.70 mm) and 0.20 ± 0.13 mm (range: 0.00-0.50 mm) in the monoblock and modular groups. Both migration and wear pattern showed no significant differences (p = 0.741 and 0.243). None of the cases required revision surgery, yielding an implant survival rate of 100% in both groups.

CONCLUSION

The isoelastic press-fit monoblock VEPE cup and modular metal-back HXLPE cup showed equivalent mid-term wear and cup migration. Long-term studies are required to determine the effects of modularity, isoelasticity, and polyethylene stabilization with vitamin E on cup loosening and survival rates.

Vitamin E-Enhanced Liners in Primary Total Hip Arthroplasty: A Systematic Review and Meta-Analysis

Objective

Adding vitamin E to highly cross-linked polyethylene liners is frequently performed in clinical practice, aiming at reducing liner wear, increasing liner survival, and delaying revision surgery. This study is aimed at evaluating the revision rate, total femoral head penetration, and postoperative clinical function of highly cross-linked polyethylene liners with and without vitamin E in total hip arthroplasty.

Methods

We conducted a systematic literature search to identify the use of highly cross-linked vitamin E liners compared to other liners in patients who received total hip arthroplasty (THA) before April 2021. The study quality assessment and data collection were conducted by two independent reviewers. Studies were artificially grouped, and vitamin E-enhanced liners (VE-PE) were compared with vitamin E-free liners (non-VE-PE). Analyses were executed using Review Manager version 5.4.1.

Results

From the preliminary screening of 568 studies, fourteen studies met the research criteria. Compared to non-VE-PE, using VE-PE reduced the all-cause revision rate (odds ratio = 0.54; 95% confidence interval (CI) 0.40, 0.73; P < 0.0001). The total femoral head penetration of the VE-PE was lower than that of the non-VE-PE (mean difference = −0.10; 95% CI -0.17, -0.03; P = 0.007). However, there was no difference in clinical function, including the Harris Hip Score and EuroQol Five-Dimension Questionnaire scores.

Conclusion

Compared to the liners without vitamin E, the addition of vitamin E to liners could reduce the all-cause revision rate by approximately 46% in the short-term follow-up. In addition, even though addition of vitamin E could also slow down femoral head penetration, there is no contribution to clinical function.