4.P.03 PRIMARY AND SECONDARY RECONSTRUCTIONS OF THE LOWER LIMB WITH GMRS® MODULAR PROSTHESES: IMPLANT SURVIVAL AND COMPLICATIONS IN A COMPARATIVE STATISTICAL ANALYSIS

Abstract

From October 2003 to September 2007 at Rizzoli 161 GMRS^® prostheses were implanted after resections of the lower limb. This is a modular system with a knee rotating hinge mechanism, cemented and uncemented stems, in titanium and chromium-cobalt-molybdenum, curved and straight-fluted, with or without hydroxyapatite coating. Adaptors are available to revise HMRS^® prostheses with hybrid implants. This study includes 88 males and 73 females ranging in age from 9 to 80 years. Sites of reconstruction were 109 distal femurs, 19 proximal femurs, 1 total femur and 32 proximal tibias. There were 149 oncologic and 12 non oncologic diagnoses, including 96 primary reconstructions and 65 revisions for failures of previous reconstructions. Analysis of imaging and complications was performed and function assessed according to MSTS system. Kaplan-Meier curves were used to statistically evaluate implant survival.

At a mean follow up of 2.5 yrs. 106 patients are continuously NED, 31 NED after treatment of relapse, 7 AWD, 5 DWD. There were 10 major complications: 8 infections (4.7%) (5 in primary and 3 in secondary implants) and 2 aseptic loosenings (1.2%) (1 each). There were 9 minor complications requiring minor revisions. Comparative statistical analysis of implant survival showed no statistically significant difference between primary and secondary implants. Functional results were good or excellent in 95% of patients, without any poor.

Middle term results are promising with no breakages of implant components. Besides oncological cases, there are selected indications in non oncological settings, such as revisions of prosthetic or allografts failures. While a higher complication rate was expected in secondary implants, statistical analysis shows similar survival.