The influence of K-line on two posterior approaches for patient with ossification of posterior longitudinal ligament

English Keywords:Ossification of posterior longitudinal ligament  K line  One-door open laminoplasty  Laminectomy  Outcome

English Abstract:

  【Abstract】 Objectives: To elevate the influence of K-line on the outcome of laminoplasty(Lam) vs laminectomy and instrumentation(LI) for patient with ossification of posterior longitudinal ligament(OPLL). Methods: 78 patients undergoing Lam(32) and LI(46) from January 2003 to February 2011 were included in this series. 54 cases with the ossification mass not beyond the line at the midpoint of spinal canal from C2 to C7 were grouped as K(+), while 24 cases with ossification mass exceeding the K-line were grouped as K(-). The preoperative and follow-up JOA scores, and postoperative complications were recorded to analyze the influence of two approaches on the outcome. Results: The improvement rate of neurologic function(IR) after posterior approaches in cases of group K(+) and K(-) was 68.2% and 38.8% respectively, which showed significant difference (P<0.01). In group K(+), the IR of cases for Lam was 69.9%, and 65.6% for LI, which showed no significant difference (P>0.05). In group K(-), the IR for LI was 47.0%s and 33.9% for Lam, which showed significant difference(P<0.05). The onset was significantly earlier and the incidence of C5 palsy was significantly higher in cases with LI than cases with Lam（P<0.05). Conclusions: Preoperative K(+) predicates a better IR than K(-). For cases with K(-), LI provide better neurologic function recovery. LI indicate higher incidences of C5 palsy and the earlier onset of axial pain.