TYPE IV ACETABULAR DEFECT TREATMENT – TREATMENT WITH A PARTIAL PELVIC REPLACEMENT RING

¹ Orthopedic and Trauma Unit, San Raffaele University Hospital, Milan, Italy
² Department of Orthopedics and Traumatology, University Vita-Salute San Raffaele, Milan, Italy
³ Vita-Salute San Raffaele University, Via Olgettina 58, 20132, Milan, Italy
⁴ Vita-Salute University, IRCCS San Raffaele Hospital, Milan, Italy

Correspondence to:

Journal of Orthopedics 2025 September-December; 17(3): 127-132
https://doi.org/10.69149/orthopedics/2025v17iss3_3

Received: 3 August 2025 Accepted: 16 September 2025

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Abstract

Reconstruction of severe pelvic discontinuity and acetabular defects is a challenging condition in hip revision surgery. Between October 2018 and July 2023, 5 hip revisions due to traumatic periacetabular osteolysis, primary osteoarthritis, or revised total hip arthroplasty (rTHA) underwent acetabular revision using partial pelvic replacement (PPR). There were 3 female and 2 male patients. The age range was between 35 and 77 years (median, 56 years). Considering the acetabular bone defects, as classified by the American Academy of Orthopedic Surgeons (AAOS), 3 cases were classified as grade III and 2 cases as grade IV. All patients underwent complete clinical and radiographic follow-up for 30 months ± 2 (minimum 16 and maximum 36 months). For all causes, none of the implants required revision. No patients developed heterotypic ossification or osteolysis at the last X-ray. Before surgery, the average pain was around VAS = 8/10, which reduced to 2/10 following surgery. After surgery, patients had an average limb length discrepancy of 15 millimeters (range, 0-20 millimeters), which was assessed both clinically and radiologically. An improvement in quality of life was observed in all patients. The overall survival of PPR was 100% at 30 months of follow-up. High overall survival rates, pain control, and limb length are achieved by reporting favorable pelvic biomechanics and intermediate-term outcomes in cases of extensive acetabular defects with pelvic discontinuity, through the use of the LINK Endo-Model PPR prosthesis.

Keywords: acetabular reconstruction, bone defect, cage device, dual mobility, partial pelvic replacement