Vol.23 No.1

Original Article

Clinical and radiographic evaluation of total hip arthroplasties using porous tantalum modular acetabular components: 5-year follow-up of clinical trial

Authors

Yasuharu Nakashima1 , Naohiko Mashima2 , Hiroshi Imai2 , Naoto Mitsugi3 , Naoya Taki3 , Yuichi Mochida3 , Ichiro Owan4 , Kaoru Arakaki4 , Takuaki Yamamoto1 , Taro Mawatari1 , Goro Motomura1 , Masanobu Ohishi1, Toshio Doi1, Masayuki Kanazawa1, Yukihide Iwamoto1

  • Department of Orthopaedic Surgery, Kyushu University, 1-3-3 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
  • Department of Bone and Joint Surgery, Ehime University, Shizugawa, Toon, 791-0295, Japan
  • Department of Orthopaedic Surgery, Yokohama City University Medical Center, 4-57 Urafune, Minamiku, Yokohama, 232-0024, Japan
  • Department of Orthopedic Surgery, University of the Ryukyu, 207 Uehara, Nishihara, 903-0215, Japan
Received:

11 January 2012

Accepted:

13 February 2012

Published online:

7 March 2012

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Abstract

Objectives Porous tantalum is a biomaterial newly applied for artificial joints. We present here 5-years followup report of a multicenter clinical trial of total hip arthroplasties (THA) with porous tantalum modular acetabular component (modular PTC).
Methods Study participants received 82 hips in 79 cases, with 61.2 months follow-up on average. Age at operation was 60.9 years. Clinical results were evaluated using Merle d’Aubigne Postel score. Presence of implant loosening, periacetabular radiolucency, osteolysis, and gap filling were examined for radiographic results.
Results Merle d’Aubigne Postel score improved from 10.0 to 16.4 points. All PTC were radiographically stable, with no evidence of progressive radiolucencies. Average polyethylene wear rate was 0.004 mm/year, with no periacetabular osteolysis. Fifteen hips (18.3%) showed a gap >1 mm; however, all showed bone filling within 12 months. PTC with oversized reaming was significantly less likely to have a gap. No implant failure was noted related to modularity. Resulting survival rate of modular PTC was 100% at 5 years.
Conclusions Modular PTC showed excellent results at 5-years of follow-up. Some hips showed periacetabular gaps, which were filled with bone within 1 year. Further follow-up was needed to determine long-term efficacy.

Key words

Clinical trial - Loosening - Porous tantalum - Radiolucency - Total hip arthroplasty