# When Is a Two-Stage Surgical Procedure Indicated in the Treatment of Pseudotumors of the Hip? A Retrospective Study of 21 Cases and a Review of the Literature

## TL;DR

This study compares one-stage and two-stage surgical treatments for hip pseudotumors and finds no difference in outcomes, but suggests two-stage is better for complex cases.

## Contribution

The study provides clinical evidence on the effectiveness of one- versus two-stage procedures for hip pseudotumors and highlights the role of 3D-printed prostheses.

## Key findings

- No significant differences in complications or functional outcomes between one- and two-stage procedures.
- Two-stage surgery is preferable for major bone defects and larger pseudotumors.
- Custom 3D-printed prostheses are increasingly used in two-stage revisions.

## Abstract

(1) Background: A pseudotumor of the hip is a sterile, non-neoplastic soft tissue mass associated with total hip arthroplasties. Pseudotumors may mimic soft tissue tumors or infections, and thus a differential diagnosis is crucial, and biopsy is recommended. The purpose of this study was to compare the complications and functional results between one-stage and two-stage procedures. (2) Methods: We retrospectively analyzed 21 patients surgically treated at our institution with “pseudotumors” associated with hip prosthesis (8 male, 13 female with a mean age of 69 years). One-stage revision was performed in 10 cases and two-stage reversion in 10, with excision only in 1 case. Complications were classified as major and minor and functional results assessed using the Harris Hip Score (HHS). (3) Results: Five patients (24%) reported major complications. The survival rate for all complications was 75%. The overall survival rate was 95% at 5 years. The mean HHS ranged from 35 pre-op to 75 post-op, highlighting improved functional results in all cases. We recorded no differences in complications or functional outcomes between the one- and two-stage procedures. (4) Conclusions: In our experience, the two-stage surgical approach is preferable in cases with major bone defects and larger pseudotumor sizes. The use of custom-made 3D-printed prostheses is increasing and is a further reason to prefer two-stage revision.