RESUMO
Objective:To investigate the clinical efficacy of percutaneous kyphoplasty (PKP) through the transverse process-pedicle approach (TPPA) by comparing with PKP through the conventional transpedicle approach (CTA).Methods:A retrospective study was conducted to analyze the data of 101 patients with single-segment osteoporotic vertebral compression fracture (OVCF) who had been treated at Department of Spine Surgery, The Fourth Hospital of Wuhan from August 2020 to August 2021. There were 31 males and 70 females, with an age of (70.3±7.6) years. Their T values of bone mineral density averaged (-3.0±0.3). They were divided into a TPPA group of 52 cases in which PKP was performed through the TPPA and a CTA group of 49 cases in which PKP was performed through the CTA. The clinical efficacy was evaluated by comparing the 2 groups in terms of operation time, frequency of intraoperative fluoroscopy, excellent to good rate of bone cement distribution, rate of bone cement leakage, refractures, and visual analogue scale (VAS), Oswestry disability index (ODI) and Beck index at preoperation, 24 hours, 3 months and 6 months postoperation.Results:There was no significant difference in the preoperative general data between the 2 groups, showing they were comparable ( P>0.05). All the patients were followed up for (9.8±1.5) months. Operations were completed successfully in all patients with no complications like nerve injury or pedicle fracture. There were no significant differences in operation time, frequency of intraoperative fluoroscopy or rate of bone cement leakage between the 2 groups ( P>0.05). In the TPPA group, the excellent to good rate of bone cement distribution [92.3% (48/52)] was significantly higher than that in the CTA group [61.2% (30/49)], the VAS score [3.0 (2.0, 4.0)] and ODI (57.2±4.6) at 24 hours postoperation were significantly lower than those in the CTA group [4.0 (3.0, 4.0) and 59.2±5.3] ( P<0.05). There were no significant differences in VAS or ODI between the 2 groups at preoperation, 3 months or 6 months postoperation ( P>0.05). The VAS and ODI improved steadily within each group, showing significant differences between every 2 time points ( P<0.05). The Beck indexes [0.81 (0.69, 0.86) and 0.76 (0.67, 0.81)] at 24 hours and 6 months postoperation in the TPPA group were significantly higher than those in the CTA group [0.75 (0.71, 0.79) and 0.72 (0.68, 0.77)] ( P<0.05). The Beck indexes at 24 hours and 6 months postoperation improved significantly in all patients compared with the preoperative values ( P<0.05). Conclusions:In the treatment of OVCF with PKP, the TPPA shows the same surgical safety as CTA does, but leads to better cement distribution, better pain relief at immediate postoperation and an advantage in restoring and maintaining the height of the injured vertebral body.
RESUMO
BACKGROUND: Percutaneous kyphoplasty (PKP) is an effective method for treating osteoporotic vertebral compression fracture. Although satisfactory clinical outcomes can be achieved, bone cement leakage is still one of the main complications of PKP. Based on previous studies, there are many high risk factors for bone cement leakage into the spinal canal; however, less attention to the posterior wall morphology of different vertebral bodies may be an important reason for bone cement leakage into spinal canal. OBJECTIVE: To investigate the effect of thoracic and lumbar vertebral posterior wall morphology in the patients with osteoporotic vertebral compression fracture on bone cement leakage into the spinal canal during the PKP. METHODS: The clinical data of osteoporotic vertebral compression fracture patients with PKP were selected. There were 98 osteoporotic vertebral compression fracture patients with CT scan and three-dimensional reconstruction image data from T6 to L5. The three-dimensional reconstruction of CT and multiplanar reconstruction were used to measure the depth of the concave vertebral posterior wall (OC) and the corresponding middle-sagittal diameter of the vertebra (PC) of the non-fractured vertebral body, the ratio of OC to PC was calculated. All subjects were divided into thoracic group (T6-T12) and lumbar group (L1-L5) based on the location of measured vertebral, and the differences of the OC between groups were compared. 357 patients (548 vertebrae) with osteoporotic vertebral compression fracture without CT three-dimensional reconstruction underwent PKP within the same period. They were also divided into thoracic vertebra and lumbar vertebra groups. The degree of bone cement leakage into the spinal canal was compared between thoracic and lumbar vertebra groups. RESULTS AND CONCLUSION: (1)The morphological parameters of posterior vertebral wall in 98 patients showed that the depth of the concave vertebral posterior wall gradually (OC) deepened from T6toT12, with an average of 4.6 mm. The depth became gradually shallow from L1 to L5, with an average of 0.6 mm. The ratio of the depth of the concave vertebral posterior wall to the corresponding middle-sagittal diameter of the vertebra was approximately 16% (1/6) from T6toT12. The average value of ratios from Li to U was 3%. The ratios in lumbar vertebra were significantly decreased compared with thoracic vertebra (16%, 1/6). (2) Results form 357 patients who underwent PKP at the same time showed that the rate of bone cement leakage into spinal canal was 10.2% (31/304) in the thoracic vertebra group during the PKP, and the rate of lumbar vertebra group was 3.7% (9/244). In the thoracic group, the average maximal sagittal diameter of the bone cement intruded spinal canal was (3.1 ±0.2) mm, the average maximal area of the bone cement intruded spinal canal was (30.8±0.3) mm2, and the spinal canal encroachment rate was (22.5±0.2)%. In the lumbar group, the average maximal sagittal diameter of the bone cement intruded spinal canal was (1.4±0.1) mm, the average maximal area of the bone cement intruded spinal canal was (14.9±0.2) mm2, and the spinal canal encroachment rate was (11,4±0.3)%. There was significant difference between thoracic and lumbar groups (P<0.05). (3) The above results imply that due to the presence of OC structure in the middle and lower thoracic vertebra, it is possible to reduce the occurrence of bone cement leakage into spinal canal through avoiding bone cement distribution over the posterior 1/6 (16%) of vertebral body in PKP. The effect of the difference between thoracic and lumbar vertebral posterior wall morphology in osteoporotic vertebral compression fracture patients on bone cement leakage into the spinal canal during the PKP may be one of the reasons why the rate of bone cement leakage into spinal canal in thoracic vertebra significantly higher than that in lumbar vertebra. The study protocol was approved by the Ethics Committee of the Affiliated Hospital of Southwest Medical University (approval No. K2018008).