Abstract
Introduction The purpose of this study is to determine the incidence of revisions following a large series of lumbar arthroplasties and to develop approach strategies for these revisions.
Methods 393 patients had lumbar arthroplasty between May of 2001 and December of 2005. Follow-up ranges from 4 years 7 months to 3 months. So far there is 100% follow-up on these patients. Only those returning for anterior revision of the device have been included in this study.
Results Overall revision rate was about 2% (8 of 393). 307 patients had a ProDisc L and 2 were revised (0.6%). One was removed and one was repositioned and remains in place 18 months post-op. 66 patients had a Charité and 5 (7.5%) had to be removed followed by antero-posterior fusion. 20 patients had a Flexicore and 1 was removed followed by fusion (5%). 5 of the revisions happened within three weeks of implantation. 1 ProDisc L was removed 8 months post-op due to anterior extrusion. 1 Charité was removed 15 months later after a posterior fusion and continued pain and 1 was removed 8 months later due to subsidence. 6 revisions were at L5–S1 and 2 were at L4–5. The 8 revisions were done successfully and without complications. All the ProDisc L and Flexicore devices were implanted as part of investigational studies. All the Charité devices were implanted after the device was approved for use in the USA in October of 2004.
Discussion It appears that revision arthroplasty is inevitable although there appears to be a difference in the early revision rate depending on the device used. Revisions at L4–5 have proved to be extremely challenging and require significant experience on the part of the surgeon. Pre and intra-operative strategies and techniques used in these cases include: pre-op imaging studies such as venograms, MRV’s and color coded radial CT scans, placement of ureteral catheters, use of pulse oxymeter in the left great toe, balloon catheters to control bleeding and use of the cell saver.
As a rule, after 10 to14 days a revision approach via the same incision should be avoided. At L5–S1 it is best to use the opposite side retroperitoneal approach. L4–5 should be approached either transperitoneally or via a more lateral retroperitoneal incision. Returns to L3–4 and L2–3 are best via a more lateral approach as well. Right-sided approaches should only be used for L5–S1. For higher levels, potential injuries to the inferior vena cava make the risk prohibitive.
The abstracts were prepared by Assoc Prof Bruce McPhee. Correspondence should be addressed to him at the Division of Orthopaedics, The University of Queensland, Clinical Sciences Building, Royal Brisbane Hospital, Herston, Brisbane, 4029, Australia.
