Comparison Of Surgical Outcomes In Thoracolumbar Fractures Operated With Varying Lengths Of Posterior Constructs-Short Segment Versus Long Segment Fixation

Objective: Surgical treatment of thoracolumbar fractures is very controversial. The optimalgoals of surgical treatment in thoracolumbar burst fractures are decompression of neural element,restoration of vertebral height and alignment, stabilization, decrease deformity and earlymobilization in order to acquire maximal recovery from neurological and functional deficits.Despite general agreement on the goals of surgical treatment, considerable controversy anddebates exist in the choice of operative techniques. It is clear that the operative managementwith internal fixation has known advantages of stability, early mobilization and rehabilitation,neurological improvement, spinal alignment and decreased deformity. Posterior instrumentationtechnique is most frequently practiced; however, the number of levels to be instrumented stillremains a matter of debate and disagreement. We want to compare the surgical outcomes ofshort segment and long segment posterior fixation for thoracolumbar burst fractures in order toprovide a theoretical basis for the better treatment of thoracolumbar fractures.Method: From Sept.2008to April2011, a total of39patients who had a single levelthoracolumbar burst fracture between T10to L3and classified as a burst fracture according toMcAfee classification or type A3fracture according to AO/Magerl classification were selected.All patients were managed by posterior instrumentation alone. The patient’s case notes,operation records, pre-op, post-op and follow up radiographs were reviewed. Patients weredivided into2groups depending upon the number and level of vertebra instrumented. Group Icomprised of24patients operated by short segment posterior fixation (SSPF), i.e; one vertebracephalad and one caudad to the fractured vertebra and Group II comprised of15patientsoperated by long segment posterior fixation (LSPF), i.e; two vertebrae cephalad and two caudadto the fractured vertebra. The mean follow up period was13.2months ranging from8months to19months. The outcomes were analysed in terms of Cobb’s Angle, Saggital Index and AnteriorBody Height (Compression Rate). X-rays were evaluated to calculate Cobb Angle, SaggitalIndex and Anterior Body Height.Results: Both short segment and long segment posterior transpedicular fixation have goodoutcomes in the treatment of thoracolumbar burst fractures in terms of correction of Cobb Angle,Saggital Index and Anterior Body Height. Operative time was significantly less in the SSPF group (average150min ranging from80-245min) compared with LSPF group (average213min ranging from130-390min)(P <0.05). A statistically significant difference between the twostudy groups was noted for the final follow up of the Cobb Angle and Anterior Body Height;similarly the mean loss of correction of Cobb Angle and Anterior Body Height at final follow upwas statistically significant between the two groups, which were better in LSPF group. While asfar as other parameters are concerned, no significant differences were noted. In our study, wealso observed that the outcomes were better in lower lumbar segments as compared to uppersegments.Conclusion: The results of our study suggest that Both Short Segment and Long SegmentPosterior Transpedicular Fixation are capable of correcting the Kyphosis and Anterior VertebralHeight Compression and are reliable surgical procedures for the treatment of thoracolumbarburst fractures; however, as time goes by on long term follow up, the Long Segment Posteriorstabilization is associated with better results compared to Short Segment stabilization as far asradiological parameters are concerned. The outcomes were better in lower lumbar segmentscompared to upper segments.