Promising results of revision total hip arthroplasty using a hexagonal, modular, tapered stem in cases of aseptic loosening

Long-term Outcomes of Revision Total Hip Arthroplasty Using a Modular Fluted Conical Femoral Stem

BACKGROUND

This study presents minimum 6-year follow-up data on the survival and satisfaction of an uncemented modular revision femoral system, following on from our previously published earlier results.

METHODS

We retrospectively reviewed all revision hip arthroplasties performed at our institution between January 2005 and October 2012, using a single modular femoral revision system. Patient-reported outcomes were collected (satisfaction score and Oxford Hip Score). Preoperative and postoperative radiographs were reviewed for stem subsidence, and Kaplan-Meier analysis was performed for survival. A total of 115 femoral revisions were performed in 106 patients.

RESULTS

All-cause survival was 82% (95% confidence interval 74 to 91%) at 10.8 years, and 96% (95% confidence interval 90 to 100%) excluding septic failure. Of the 19 cases requiring reoperation, 16 were for infection, 2 for aseptic loosening, and 1 for mechanical failure. At final follow-up, 88.5% of patients were "satisfied" or "very satisfied".

CONCLUSIONS

This study showed excellent clinical results of a commonly used revision hip stem with at least 10 years follow-up. Satisfaction rates were high, with few aseptic failures. Stem subsidence was more common in revisions for infection, but did not correlate with lower satisfaction scores.

The Role of Single Positive Cultures in Presumed Aseptic Total Hip and Knee Revision Surgery-A Systematic Review of the Literature

(1) Background: Prior to revision hip (THA) or knee arthroplasty (TKA), periprosthetic low-grade infection (PJI) should be ruled out. Despite advances in preoperative diagnosis, unsuspected positive cultures (UPCs) may occur in initially planned aseptic revisions. Particularly, single UPCs pose a diagnostic and therapeutic dilemma, as their impact on outcome is unclear and recommendations are heterogeneous. This review investigates the frequency of single UPCs and their impact on implant survivorship. (2) Methods: In July 2022, a comprehensive literature search was performed using PubMed and Cochrane Library search. In total, 197 articles were screened. Seven retrospective studies with a total of 5821 cases were able to be included in this review. (3) Results: Based on the cases included, UPCs were found in 794/5821 cases (14%). In 530/794 cases (67%), the majority of the UPCs were single positive. The most commonly isolated pathogens were coagulase negative Staphylococci and Cutibacterium acnes. Five of seven studies reported no influence on revision- or infection-free survival following a single positive culture. In two studies, single UPCs following THA revision were correlated with subsequent re-revision for PJI. (4) Conclusions: Single UPCs of a non-virulent pathogen following presumed aseptic TKA revision may be interpreted as contaminants. A single UPC following THA revision may be a risk factor for subsequent PJI. The role of systemic antibiotic treatment remains unclear, but it should be considered if other risk factors for PJI are present.

Unsuspected Positive Cultures in Planned Aseptic Revision Knee or Hip Arthroplasty-Risk Factors and Impact on Survivorship

BACKGROUND

Unsuspected positive cultures (UPCs) may be found at the time of planned aseptic revision surgery and have previously been associated with decreased implant survival. However, reported rates vary greatly, and potential risk factors are widely unknown. This study investigates the rate of UPCs, implant survival, as well as potential risk factors for UPCs and revision.

METHODS

This is a retrospective, single-center study on 434 cases of total hip arthroplasty (THA 277) and knee revision arthroplasty (TKA 157) performed between 2010 and 2017. Microbiology culture results, revision-free survival (RFS) and infection-free (IFS) survival, and the potential impact of UPCs as well as patient- or procedure-related risk factors were investigated at a minimum follow-up of 24 months (median 41 months).

RESULTS

A total of 37% of patients had a positive culture (160/434). 27% (119/434) had a solitary positive culture, and 9% (41/434) had ≥2 positive cultures of the same species. Most commonly, coagulase-negative staphylococci were cultured. Overall, 32% (13/41) of patients with ≥2 positive cultures underwent revision for infection compared with 6% (17/274) of patients with negative cultures. RFS and IFS were reduced if ≥2 cultures were positive. Single positive cultures had no impact on RFS or IFS. Male sex, elevated serum C-reactive protein, and obesity were independently associated with finding ≥2 UPCs in revision THA.

CONCLUSION

Appearance of ≥2 UPCs in aseptic revision leads to reduced RFS and IFS. Males, obese patients, and patients with elevated serum C-reactive protein planned for THA revision should be considered for extended diagnostics to rule out periprosthetic joint infection.

Aseptic Revision of Total Hip Arthroplasty With a Single Modular Femoral Stem and a Modified Extended Trochanteric Osteotomy-Treatment Assessment With the Forgotten Joint Score-12

Background

Aseptic loosening is among the most common reasons for revision total hip arthroplasty (RTHA). Modular revision stems implanted through an extended trochanteric osteotomy (ETO) promise good results, but patient-reported outcome measures (PROMs) are rarely conveyed. This study used the Forgotten Joint Score-12 (FJS-12) to assess patient-reported outcome in patients who had undergone RTHA for aseptic stem loosening using a modified ETO approach with a tapered, fluted modular stem.

Material and methods

A single-center analysis of aseptic RTHA was performed (2007–2019). Clinical results (range of motion, walking ability, function), radiographic results (ETO healing, stem subsidence), and PROMs (FJS-12, Harris Hip Score, European Quality of Life 5D Score) were assessed. Minimum follow-up duration was 1 year. Complications including revisions were recorded.

Results

Primary outcome parameters were assessed on 72 patients (mean age 73.3 years, mean body mass index 27.6kg/m²). Additional PROMs were collected by phone interviews from 41 patients (mean follow-up 5.7 years). In 76%, leg length was restored, and a normal gait was achieved. After 1 year, the ETO was healed in 93%; subsidence occurred in 8.3% of cases. The mean FJS-12 at the final follow-up was 85.6 ± 23.6, and the respective Harris Hip Score and European Quality of Life 5D Score averaged 87 ± 17.8 and 72.9 ± 15.9. Complication and revision rates were 33.3% and 13.9%, respectively.

Conclusion

Aseptic RTHA as presented here resulted in excellent PROMs in the medium term. FJS-12 score averaged 85.6 with a mean follow-up of 5.7 years. Treatment using a modular implant and a modified ETO was associated with good clinical and radiographic outcomes. Complication and revision rates were 33.3% and 13.9%, respectively.