A Minimally Invasive Approach for Posterior Lumbar Fusion
Object: Despite the technical innovations that posterior approaches for lumbar fusion have undergone, the goal of a significant reduction in the extent of dissection has remained elusive. Because extensive muscular dissection is related to both acute and chronic pain, a reproducible minimally invasive posterior approach to lumbar interbody fusion would have significant clinical value. The technical aspects of a minimally invasive approach to posterior lumbar interbody fusion (µPLIF) with fixation involving tools developed for videoscopic discectomy will be described.
Methods: The technical description of this µPLIF procedure is based on experience gained in the first 38 cases. Outcomes categorized using a modified Macnab criteria are reported for 13 patients in whom 1 year or more of follow-up data were available.
All procedures were completed. The section of anulus fibrosus that was exposed provided access for a thorough discectomy and endplate preparation. Outcome in 11 of the 13 patients in whom outcome data were available was excellent or good. Six of these patients returned to work between 3 and 12 weeks postoperatively. Two patients suffered complications related to insertion of the interbody device.
Conclusions: This procedure involves a reproducible technique that results in a construct that is radiographically identical to that which could be expected from any standard open procedure. The minimized muscular dissection results in a tremendous improvement in postoperative mobility. All complications in this series were related to the placement of femoral cortical allograft implants. The use of a modified cement restrictor should eliminate the risk of interbody device placement.
Cloward first described PLIF at the 1947 meeting of the Hawaiian Medical Society (Coward RB, unpublished data). He published his first series in 1953. Although Cloward had good success and limited complications, the procedure did not flourish. Except for sporadic cases performed by Cloward, Lin and his associates, along with a small cadre of his followers, the procedure would languish for the next 50 years. It was because of Lin's continued efforts that curiosity in the procedure was kept alive. It was not until after live telecasts of surgery in 1977 and again in 1983, however, that wide-ranging interest began (Lin PM, unpublished data). By the end of the 1980s, this interest rapidly grew into a movement. The result was a vindication of Cloward's earlier vision. During the last decade, a paradigm shift has silently occurred, culminating in the fact that today lumbar spinal fusion in most arenas is synonymous with lumbar interbody fusion.
Posterior lumbar interbody fusion and its variations are labor intensive, and the anatomy encountered during this approach generates significant technical demands. The obligatory extensive dissection produces significant pain, which in some cases can become chronic. At the very least, this is a leading factor resulting in extended hospital stays and inflated costs. In the last century the major thrust of the scientific endeavor concerned the achievement of reliably high fusion rates. Whereas this labor has been successful, the significant problem of surgery-induced pain has shared in little of this success. In fact, the resultant routine use of pedicle screw fixation has only served to intensify this problem.
Methods that serve to reduce these problems would be beneficial. An ideal procedure would minimize dissection and pain, allow neural decompression reestablish the disc space with interbody fusion, lend itself to the application of internal fixation, and have complications that are both acceptable in nature and frequency. A technique for a minimally invasive PLIF is described that brings us closer to these goals.
Object: Despite the technical innovations that posterior approaches for lumbar fusion have undergone, the goal of a significant reduction in the extent of dissection has remained elusive. Because extensive muscular dissection is related to both acute and chronic pain, a reproducible minimally invasive posterior approach to lumbar interbody fusion would have significant clinical value. The technical aspects of a minimally invasive approach to posterior lumbar interbody fusion (µPLIF) with fixation involving tools developed for videoscopic discectomy will be described.
Methods: The technical description of this µPLIF procedure is based on experience gained in the first 38 cases. Outcomes categorized using a modified Macnab criteria are reported for 13 patients in whom 1 year or more of follow-up data were available.
All procedures were completed. The section of anulus fibrosus that was exposed provided access for a thorough discectomy and endplate preparation. Outcome in 11 of the 13 patients in whom outcome data were available was excellent or good. Six of these patients returned to work between 3 and 12 weeks postoperatively. Two patients suffered complications related to insertion of the interbody device.
Conclusions: This procedure involves a reproducible technique that results in a construct that is radiographically identical to that which could be expected from any standard open procedure. The minimized muscular dissection results in a tremendous improvement in postoperative mobility. All complications in this series were related to the placement of femoral cortical allograft implants. The use of a modified cement restrictor should eliminate the risk of interbody device placement.
Cloward first described PLIF at the 1947 meeting of the Hawaiian Medical Society (Coward RB, unpublished data). He published his first series in 1953. Although Cloward had good success and limited complications, the procedure did not flourish. Except for sporadic cases performed by Cloward, Lin and his associates, along with a small cadre of his followers, the procedure would languish for the next 50 years. It was because of Lin's continued efforts that curiosity in the procedure was kept alive. It was not until after live telecasts of surgery in 1977 and again in 1983, however, that wide-ranging interest began (Lin PM, unpublished data). By the end of the 1980s, this interest rapidly grew into a movement. The result was a vindication of Cloward's earlier vision. During the last decade, a paradigm shift has silently occurred, culminating in the fact that today lumbar spinal fusion in most arenas is synonymous with lumbar interbody fusion.
Posterior lumbar interbody fusion and its variations are labor intensive, and the anatomy encountered during this approach generates significant technical demands. The obligatory extensive dissection produces significant pain, which in some cases can become chronic. At the very least, this is a leading factor resulting in extended hospital stays and inflated costs. In the last century the major thrust of the scientific endeavor concerned the achievement of reliably high fusion rates. Whereas this labor has been successful, the significant problem of surgery-induced pain has shared in little of this success. In fact, the resultant routine use of pedicle screw fixation has only served to intensify this problem.
Methods that serve to reduce these problems would be beneficial. An ideal procedure would minimize dissection and pain, allow neural decompression reestablish the disc space with interbody fusion, lend itself to the application of internal fixation, and have complications that are both acceptable in nature and frequency. A technique for a minimally invasive PLIF is described that brings us closer to these goals.
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