Stay Short or Go Long in Revision Total Hip Arthroplasty With Paprosky Type II Femoral Defects: A Comparative Study With the Use of an Uncemented Distal Fixating Modular Stem and a Primary Monobloc Conical Stem With 5-Year Follow-Up

Mid-term results of a cementless hip stem in femoral revision: how much diaphyseal press-fit do we need?

INTRODUCTION

The aim of this retrospective study was to analyze the clinical and functional outcome of a modular tapered revision hip stem after mid-term follow-up with a special focus on the length of the distal bicortical fixation of the cementless hip stem.

MATERIALS AND METHODS

Follow-up examination was carried out for all patients with implantation of the Prevision hip stem between 2014 and 2019 to collect demographic, functional, and radiographic data.

RESULTS

44 patients with stem in situ were examined, and 61 patients could be included in the Kaplan-Meier survival analysis. Oxford's hip score was 37.3 at the mean follow-up of 4.0 years. Two hip stem revisions were performed due to periprosthetic infection, which resulted in a hip stem survival rate of 96.7% (CI: 87.4-99.1%) at the final follow-up of 7.5 years. No aseptic hip stem revision was required. The length of bicortical distal fixation was in the interquartile range of 6.8 to 9.0 cm, which was associated with good bone healing and a low rate of subsidence (4.5%). Implant-associated complications were observed in 10 cases (21.7%).

CONCLUSIONS

The modular revision hip stem provides promising results at medium-term follow-up, with satisfactory clinical and functional outcomes comparable to other modular revision hip stems. The presented length of bicortical distal fixation shows the practice of the study center and was associated with good implant survival, bone healing and radiological results.

REGISTRATION

Clinicaltrials.gov registration: NCT04833634 registered on April 6, 2021.

Cementless Primary Stems in Revision Hip Arthroplasty: A Narrative Review

Cementless primary stems in revision hip arthroplasties may be conservative options to preserve bone stock and provide adequate reconstruction of the hip biomechanics. However, there is still little evidence about indications, limitations, and outcomes. This narrative review showed that conventional standard stems were adopted in different revision settings, up to Paprosky IIIA grade bone defects. In cases of acceptable metaphyseal bone stock, when a scratch fit of at least 4 cm can be achieved, a conventional cementless stem may be an adequate solution. Mid-term clinical and radiographic outcomes and survival rates were similar to long revision stems, whereas complications, surgical time, and costs were lower among conventional stems. However, unsuitable contexts for conventional stems included canal diameters larger than 18 mm and failed revision stems with cortical weakening. Even short stems can be considered in revisions, in order to preserve bone stock and stay proximal to femoral remodeling zones and bone/cement plugs. Short stems were successfully adopted up to Paprosky IIIA bone defects, achieving mid-term survival rates not inferior to long revision stems. Ageing, osteoporosis, and intraoperative femoral fractures were the main negative prognostic factors. In very select cases, a downsizing technique (from longer to shorter stems) may be adopted to simplify the procedure and reduce complications.

Does size matter? Outcomes following revision total hip arthroplasty with long or primary stems: a systematic review and meta-analysis

BACKGROUND

Femoral reconstruction with long stems is widely accepted as the standard in revision total hip arthroplasty (rTHA). However, long stems can be technically challenging to insert and can compromise bone stock for future revision. This study aimed to identify whether there was a difference in outcomes with using a long versus primary or short femoral stem in revision.

METHODS

We performed a systematic review and meta-analysis of all articles comparing long and primary stem length in rTHA for Paprosky 1-3B femoral defects. The primary outcome measure was the reoperation rate after rTHA. Secondary outcomes included infection and dislocation rates, periprosthetic fracture, loosening, mortality, and patient-reported outcome measures (PROMs).

RESULTS

The results of 3,102 rTHAs performed in 2,982 patients were reported from 9 eligible studies in the systematic review, of which 6 were included in the meta-analysis. The mean patient age was 67.4 and the mean follow-up lasted 5 years (range, 1-15 years). There was no significant difference in the reoperation rate (odds ratio 0.78; 95% confidence interval, 0.28-2.17, P = 0.63). Similarly, there was no significant difference in dislocation or periprosthetic fracture risk. Harris Hip Score was better with primary stems by a mean difference of 14.4 points (P < 0.05). Pooled 5-year stem-related survival was 91.3% ± 3.5% (SD) for primary stems and 89.9% ± 6.7% (SD) for long stems.

CONCLUSIONS

A primary stem provided non-inferior outcomes compared with long stems in rTHA with Paprosky type 1-3B femoral defects. Primary stems may yield a more straightforward technique and preserve distal bone stock for future revision particularly in younger patients. In older patients with lower functional demands and who would benefit from a decreased risk of complications, a long cemented stem is recommended.

The use of a standard-length conical tapered stem in hip revision arthroplasty to address Paprosky type I-II femoral defects: a prospective study of 87 patients

INTRODUCTION

Low-grade femoral defects in revision total hip arthroplasty (rTHA) might be preferably treated with a primary implant. Almost no previous study reported the use of standard-length conical tapered (SLCT) stems in these cases. We analyzed a series of cases using a SLCT stem in rTHA with Paprosky type I-II femoral defects. The purpose of the study was to determine clinical and radiographic outcomes in this series of rTHA.

MATERIALS AND METHODS

We prospectively followed 87 patients undergoing a femoral component rTHA: 53 Paprosky type I and 34 type II femoral defects. Patient-reported measures (Oxford Hip Score, EQ-5D, VAS pain during rest and activity) were administered at baseline, 1 and 2 years post-operatively. Radiographic subsidence overtime was scored. Kaplan-Meier curves were used to evaluate the subsidence over time, the complication-free survival, and the implant survivorship with reoperation and stem revision as endpoints.

RESULTS

The mean follow-up was 72.5 (SD ± 23.9) months. All PROMs significatively improved over time. The average subsidence was 2.8 (SD ± 3.2), 3.6 (SD ± 4.4), and 4.0 (SD ± 4.9) mm at 4, 12, and 24 months respectively. 6 stems had subsidence > 10 mm. The survival without complication was 0.85 (95% CI 0.94-0.77), while the implant survival without reoperation was 0.83 (95% CI 0.95-0.72). The overall stem survival rate was 93.7% (95% CI 0.91-0.97) at 2 years.

CONCLUSION

The use of a SLCT stem in rTHA with Paprosky type I-II femoral defects demonstrated good survival with low subsidence rates during the first 2 years after surgery. Surgeons should consider the use of this primary prosthesis as a potential treatment during stem revision in cases with limited femoral bone loss.