Patients
This was a retrospective study including 224 inpatients with OVCF in our department since January 2017 to September 2019. The inclusion criteria were as follows: 1) acute vertebral compression fracture(within 1 week); 2) age≥60 years ; 3) single segmental fracture and fracture level lower than T6; 4) decreased bone mineral density(T scores less than -1.5). Patients combined with other trauma or fractures, with previous other spinal surgery, with metabolic bone diseases, metastasis, uncorrectable coagulopathy, spinal deformity, spinal infection, severe cardiopulmonary and cerebrovascular diseases, or mental disease who could not to complete the questionnaire survey were excluded.
Treatments
All patients were confined to strict bed rest after fracture, nonsteroidal anti-inflammatory drugs were given to all patients, PKP procedures were performed within 1 week after fracture.
Patients were placed in a prone position on the operating table, local infiltration anesthesia and operation was performed by 2 senior orthopedists. Bone puncture trocars were placed through the lateral margin of the pedicles at 10 o’clock on the left side and at 2 o’clock on the right side as entry points at the fractured level and were progressively passed through pedicles into the anterior third of the vertebral body under C-arm guidance. Then, an inflatable bone balloon was used and polymethylmethacrylate was injected carefully into the vertebral body (approximately 3-5 cc per level). The injection was stopped if the cement reached the cortical edge of the vertebral body or if it leaked into extraosseous structures or veins. After the procedure, the patients were maintained in a prone position for 10-15 minutes.
All patients were examined by spinal X-ray 3 days after operation to confirm the distribution of bone cement. Nonsteroidal anti-inflammatory drugs were given to all patients within 1 week following operation and soft lumbar support belts were given to all patients within 1 month postoperatively. All patients resumed functional exercise routinely 1 day after operation and were reexamined regularly in out-patient clinic.
Data Collection
All patients were followed-up for 1 year after operation, the preoperative questionnaire survey was completed in the ward in paper form and postoperative questionnaire survey was at the timepoints of 1 week, 1, 3, 6, and 12 months after surgery. Demographic variables including age, gender, diabetes status, body mass index(BMI), insurance status and times of PKP surgery were assessed. Perioperative outcomes were also recorded, including anesthesia type, duration of operation, blood loss and length of hospital stay.
Preoperative depression and anxiety were each evaluated using HAMD and HAMA[17,18], both these scales are considered to be one of the most standardized and validated tools in psychiatry for research purposes. The HAMD-17 contents 17 items and higher the total score means more severe the depressive symptoms, in this paper, a total score of 7 points and above indicates there is depression. The HAMA consists of 14 items and 2 factors (somatic anxiety and mental anxiety) and the higher the total score also means more severe anxiety symptoms, in this paper, A total score of 7 points and below indicates no anxiety. All patients were divided into to cohorts according the results of preoperative psychological questionnaire, patients with HAMD score≥7 and/or HAMA score>7 were considered to have PPS, while HAMD score<7 and HAMA score≤7 indicates that there are no PPS.
Functional outcomes was measured by Patient-Reported Outcome Measurement Information System Physical Function(PROMIS PF), compared with the traditional measurements, PROMIS PF showed good discriminant ability, concurrent effectiveness and responsiveness. A higher PROMIS PF score indicate better physical function. Visual Analogue Scales (VAS) was used to assess the back pain of patients[19], with a mark on a 10-cm line that best described their present level of pain, higher the VAS score also means more severe back pain.
Statistical Analyses
Continuous variables were presented as means and their standard deviations (SD). All statistical analyses were performed using Statistical Package for Social Sciences (SPSS) version 18.0. The normal distribution of the sample patient population was examined by the histogram, so as to evaluate the symmetry of the sample patient population. Independent sample t-tests were used to determine the difference of demographic variables as well as perioperative outcomes between two cohorts. Multiple linear regression model controlling demographic variables were used to analysis physical function and pain pre- and post PKP in relation to depression and anxiety. Stepwise regression were used to determine independent risk factors for postoperative physical function after PKP including demographic variables and perioperative outcomes, the variables with the highest p-values were then excluded until only those that were significant remained. Finally, only patients’ age and times of PKP surgeries were determined as independent risk factors related to postoperative outcomes following PKP, and be included into the multiple regression analysis. P value ≤ 0.05 was considered statistically significant.