经伤椎固定及植骨治疗胸腰椎Magerl A3型骨折

Posterior instrumentation and bony graft in fractured vertebra for thoracolumbar Magerl type A3 fractures

目的:总结经伤椎椎弓根螺钉固定及经伤椎椎弓根椎体内羟基磷灰石人工骨植骨治疗新鲜胸腰椎Magerl A3型骨折的疗效,并与传统跨伤椎4枚椎弓根螺钉内固定方法比较。方法:2004年10月至2008年8月,对54例Magerl A3型胸腰段(T12～L2)骨折患者分别采用后路传统跨伤椎4枚椎弓根螺钉内固定、减压复位、植骨融合术(A组)或附加伤椎椎弓根螺钉固定、减压复位、经伤椎椎弓根椎体内植骨融合术(B组)治疗。A组30例,男16例,女14例;年龄18～54岁,平均43.9岁;T128例,L115例,L27例;Cobb角18.2°～27.4°,平均22.3°;伤椎前缘高度46.2%～68.4%,平均51.9%;椎管占位率18.8%～48.9%,平均24.1%;3例合并不完全性脊髓损伤,均为FrankelD级。B组24例,男14例,女10例;年龄19～61岁,平均41.0岁;T125例,L110例,L29例;Cobb角18.4°～28.9°,平均19.8°;伤椎前缘高度47.6%～70.5%,平均52.4%;椎管占位率19.7%～49.6%,平均24.9;3例合并不完全性脊髓损伤,FrankelC级1例,D级2例。随访两组患者的临床及影像学资料。结果:A组手术时间86～131min,平均102min;B组72～123min,平均94min。术中失血量A组215～1005ml,平均485ml;B组100～880ml,平均420ml。两组伤口均Ⅰ期愈合。术后A组Cobb角矫正至5.1°±1.3°,B组矫正至3.2°±1.5°;椎体前缘高度A组恢复至80.7%,B组恢复至89.7%;椎管占位率A组为(8.2±1.6)%,B组为(4.9±1.8)%。两组Cobb角、椎体前缘高度和椎管占位率与术前比较均有统计学差异,两组间术后比较亦有统计学差异(P<0.05)。所有患者均接受至少1年的随访,A组平均随访34个月,B组32.6个月,末次随访时A组Cobb角为8.2°±1.5°,B组4.1°±1.6°;椎体前缘高度A组79.3%,B组88.1%;椎管占位率A组为7.8%,B组为4.2%。末次随访时A组Cobb角、椎体前缘高度和椎管占位率与B组比较均有显著性差异(P<0.05)。A组有2例在末次随访时后凸角度丢失>10°,3例内固定失败,而B组没有内固定失败病例。结论:经伤椎置钉能有效地恢复椎体前缘高度,经伤椎椎弓根椎体内植骨重建可有效维持复位,减少后凸畸形矫正丢失及内固定失败的发生。

Objective：To investigate and compare the clinical outcome of posterior instrumentation and bony graft in fractured vertebra using hydroxyapatite for fresh thoracolumbar Magerl type A3 fractures with conventional protocol.Method：Between October 2004 and August 2008,54 patients with thoracolumbar Magerl type A3 fractures were divided into two groups,30 patients in group A underwent conventional posterior short-segment fixation,and 24 patients in group B included experienced posterior instrumentation and bony graft in fractured vertebra using hydroxyapatite.The mean age of group A was 43.9 years（range,18-54 years）,the involved vertebrae included T12（8 cases）,L1（15 cases） and L2（7 cases）.Cobb angle was 22.3°（range,18.2°27.4°）.Anterior vertebra height was 51.9%（range,46.2%-68.4%）.Canal encroachment rate was 24.1%（range,18.8%-48.9%）.Three cases were graded as Frankel D.The mean age of the group B was 41.0 years（range,19-61 years）,involved vertebrae included T12（5 cases）,L1（10 cases） and L2（9 cases）.Cobb angle was 19.8°（range,18.4°-28.9°）.Anterior vertebral height was 52.4%（range,47.6%-70.5%）.Canal encroachment rate was 24.9%（range,19.7%-49.6%）.One case was graded as Frankel C and two as Frankel D.The clinical outcome and radiographic findings were reviewed retrospectively.Result：The average operation time in group A was 102 minutes（range,86-131 minutes）,in group B was 94 minutes（range,72-123 minutes）.The average blood loss in group A was 485ml（215-1005ml） and group B of 420ml（100-880ml）.All skin incision healed well.Cobb angle were corrected to 5.1°±1.3° of postoperation for group A and 3.2°±1.5° for group B.Anterior vertebral height recovered to 80.7% for group A and 89.7% for group B.Canal encroachment rate was（8.2±1.6）% for group A and（4.9±1.8）% for group B.All showed group B had a better outcome（P 0.05）.All patients were followed for a minimum of one year,with the mean follow-up for group A and B of 34 and 32.6 months respectively.At final follow up,Cobb＇s angle was 8.2°±1.5° for group A and 4.1°±1.6° for group B.Anterior vertebral height was 79.3% for group A and 88.1% for group B.Canal encroachment rate was 7.8% for group A and 4.2% for group B,which all showed that group B had a better outcome at final follow-up（P0.05）.More than 10° correction loss occurred in two of the 30 fracture vertebrae in Group A,and the implant failure was found in three cases,while there are no implant failure in group B.Conclusion：Posterior instrumentation and bony graft in fractured vertebra can maintain reduction as well as decreasing the rate of correction loss and instrument failure.