Priyan R Landham1, Angus S Don2, Peter A Robertson3. 1. Department of Orthopaedic Surgery, Southmead Hospital, Bristol, UK. 2. Department of Orthopaedic Surgery, Auckland City Hospital, Auckland, New Zealand. 3. Department of Orthopaedic Surgery, Auckland City Hospital, Auckland, New Zealand. p.a.robertson@xtra.co.nz.
Abstract
PURPOSE: To examine monosegmental lordosis after posterior lumbar interbody fusion (PLIF) surgery and relate lordosis to cage size, shape, and placement. METHODS: Eighty-three consecutive patients underwent single-level PLIF with paired identical lordotic cages involving a wide decompression and bilateral facetectomies. Cage parameters relating to size (height, lordosis, and length) and placement (expressed as a ratio relative to the length of the inferior vertebral endplate) were recorded. Centre point ratio (CPR) was the distance to the centre of both cages and indicated mean position of both cages. Posterior gap ratio (PGR) was the distance to the most posterior cage and indicated position and cage length indirectly. Relationships between lordosis and cage parameters were explored. RESULTS: Mean lordosis increased by 5.98° (SD 6.86°). The cages used varied in length from 20 to 27 mm, in lordosis from 10° to 18°, and in anterior cage height from 10 to 17 mm. The mean cage placement as determined by CPR was 0.54 and by PGR was 0.16. The significant correlations were: both CPR and PGR with lordosis gain at surgery (r = 0.597 and 0.537, respectively, p < 0.001 both), cage lordosis with the final lordosis (r = 0.234, p < 0.05), and anterior cage height was negatively correlated with a change in lordosis (r = -0.297, p < 0.01). CONCLUSION: Cage size, shape, and position, in addition to surgical technique, determine lordosis during PLIF surgery. Anterior placement with sufficient "clear space" behind the cages is recommended. In addition, cages should be of moderate height and length, so that they act as an effective pivot for lordosis.
PURPOSE: To examine monosegmental lordosis after posterior lumbar interbody fusion (PLIF) surgery and relate lordosis to cage size, shape, and placement. METHODS: Eighty-three consecutive patients underwent single-level PLIF with paired identical lordotic cages involving a wide decompression and bilateral facetectomies. Cage parameters relating to size (height, lordosis, and length) and placement (expressed as a ratio relative to the length of the inferior vertebral endplate) were recorded. Centre point ratio (CPR) was the distance to the centre of both cages and indicated mean position of both cages. Posterior gap ratio (PGR) was the distance to the most posterior cage and indicated position and cage length indirectly. Relationships between lordosis and cage parameters were explored. RESULTS: Mean lordosis increased by 5.98° (SD 6.86°). The cages used varied in length from 20 to 27 mm, in lordosis from 10° to 18°, and in anterior cage height from 10 to 17 mm. The mean cage placement as determined by CPR was 0.54 and by PGR was 0.16. The significant correlations were: both CPR and PGR with lordosis gain at surgery (r = 0.597 and 0.537, respectively, p < 0.001 both), cage lordosis with the final lordosis (r = 0.234, p < 0.05), and anterior cage height was negatively correlated with a change in lordosis (r = -0.297, p < 0.01). CONCLUSION: Cage size, shape, and position, in addition to surgical technique, determine lordosis during PLIF surgery. Anterior placement with sufficient "clear space" behind the cages is recommended. In addition, cages should be of moderate height and length, so that they act as an effective pivot for lordosis.
Entities:
Keywords:
Cage; Fusion; Lordosis; Lumbar; Position
Authors: Frank Schwab; Benjamin Ungar; Benjamin Blondel; Jacob Buchowski; Jeffrey Coe; Donald Deinlein; Christopher DeWald; Hossein Mehdian; Christopher Shaffrey; Clifford Tribus; Virginie Lafage Journal: Spine (Phila Pa 1976) Date: 2012-05-20 Impact factor: 3.468
Authors: Brian A Karamian; Stephen DiMaria; Mark J Lambrechts; Nicholas D D'Antonio; Andrew Sawires; Jose A Canseco; I David Kaye; Barrett I Woods; Mark F Kurd; Jeffery A Rihn; Joseph K Lee; Alan S Hilibrand; Christopher K Kepler; Alexander R Vaccaro; Gregory D Schroeder Journal: J Craniovertebr Junction Spine Date: 2022-06-13
Authors: Stavros Oikonomidis; Vincent Heck; Sonja Bantle; Max Joseph Scheyerer; Christoph Hofstetter; Stefan Budde; Peer Eysel; Jan Bredow Journal: Int Orthop Date: 2020-07-13 Impact factor: 3.075