A Clinical Investigation Of Contralateral Radiculopathy After Transforaminal Lumbar Interbody Fusion(TLIF)

Objective: Although transforaminal lumbar interbody fusion(TLIF) surgery has been widely used for the treatment of degenerative diseases of the spine, contralateral radiculopathy, as a potential postoperative complication after TLIF surgery, has not yet attracted much attention. But the complications have a direct impact on the effect and rehabilitation after the operation. The purpose of this study is to analyze the morbidity of contralateral radiculopathy in patients after TLIF surgery and the treatment outcomes, and to explore its possible causes.Methods: A retrospective study was conducted involving a total of 476 patients who underwent TILF from January 2009 to December 2012 in our hospital. And the operation for single segment was in 359 cases, double segments in 117 cases. There were male 291 cases, female 185 cases included and the age 19-68 years old, average 55.3 years old. These cases were divided into symptomatic group(Group S) and non-symptomatic group(Group N), according to the presence of postoperative contralateral radiculopathy. 40 cases(Group N) were randomly selected among the 458 cases of non-symptomatic group including 22 males and 18 females. The two groups of patients were followed up for 6-28 months, average 14.3 months. Lumbar anteroposterior and lateral X-ray and intervertebral foramen CT scan of surgical segment were taken before and after surgery or follow-up. The difference of contralateral foramen area and disc-height index(DHI) before and after surgery were compared between Group S and a random sample of 40 cases of non-symptomatic group patients(group N). In addition, according to whether underwent second surgery or not, Group S were further divided into transient neurologic symptoms group(Group T) and operations exploration group(Group O). The time of symptom appearance, duration of the symptom, reactions for dehydrating drugs, symptomatic severity(according to VAS, JOA scores) were statistically analyzed and compared among Group T and O. The 1-year follow-up in Group O after the second operation was carried on to analyze the improvement rate of postoperative symptom(JOA score).Results: Among the 476 patients, 18 had postoperative contralateral neurological symptom. Thus the morbidity was 3.7815%. The difference of contralateral foramen area and disc-height index(DHI) of Group S(+1.7mm2±10.1; 0.01±0.16) compared with Group N(+5.8mm2±4.5; 0.18±0.23) were statistically significant(P<0.05). There were 5 cases(Group O) in Group S had second surgery because of invalid conservative treatment including 3 males and 2 females. Surgical exploration rate were 1.0504%. The remaining 13 cases of transient neurologic symptoms(Group T), including 8 cases male and 5 cases female. There were significant differences in terms of the time of symptom appearance(mean value of Group T 86.7h postoperative; mean value of Group D 28 h postoperative), symptom duration(Group T mean 57.4h; Group D mean 270.6h), response to dehydrating drugs(Group T response rate 88.9%; Group D response rate 0%), symptom severity(Group T JOA mean 24.78, VAS mean 2.85; Group D JOA mean 13.4, VAS mean 6.6) and other indicators between Group T and Group O(P<0.05). The 1-year follow-up in Group D showed that the improvement rate of postoperative symptom(JOA score) was 95.42%.Conclusions: Contralateral radiculopathy is a potential complication after TLIF, and its causes are possibly associated with change in pattern of postoperative contralateral intervertebral foramen, postoperative nerve edema reactions, displacement of bone graft, and unsuitable pedicle screw location. Surgical explorations should be conducted early for those patients with the complication who presented with obvious nerve damage.