Domestic and foreign scholars have confirmed the good therapeutic effect of PKP on OVCF[8, 10]. Meanwhile, PKP is effective for restoring vertebral body height and correcting kyphosis and has several advantages of being minimally invasive and safe, offering rapid pain relief, and involving simple manipulation techniques[21, 22]. The aim for good treatment for OVCF is supposed to achieve improvement in symptoms, kyphosis deformity correction and prevention of new fractures[23–25]. However, PKP for OVCF could be divided into unilateral and bilateral approaches. Until now, the best treatment option is still controversial for symptomatic OVCF without neurological deficits. Some authors concluded that the benefits of bilateral percutaneous kyphoplasty regarding pain relief, low rates of cement leakage, and height restoration have been documented, but several retrospective studies concluded that a unilateral percutaneous kyphoplasty might provide similar results for clinical and radiographic outcomes as bilateral percutaneous kyphoplasties[26, 27]. However, less retrospective study was proceeded to compare vertebral local kyphosis correction between the unilateral and bilateral PKP.
Our retrospective study exhibited that both unilateral and bilateral PKP markedly improved the outcome of patients with OVCF. This was reflected in considerable change in VAS and ODI as well as a significant improvement in the Kyphosisangle after treatment. However, no statistically significant differences were observed compared between the two groups at all time intervals. These results support that both unilateral and bilateral PKP were effective methods in the treatment of OVCF.
In our study, the operative time and amount of cement perfusion doses to the patient are significantly different between the unilateral and the bilateral groups. We found that the unilateral group has shorter operative time and lesser bone cement volume than the bilateral group. Besides, this means that the unilateral approach was less costly than the bilateral group, which was confirmed in a recent meta-analysis [28] and consistent with the findings of Rebolledo et al[19].Statistically significant differences were observed when the operation time and cement amount were compared between the groups.
According to the abovementioned results, unilateral PKP can effectively restore the height of the injured vertebrae, can correct the kyphosis, has shorter operative time, and can be easily performed. The contralateral bone density was increased via one-sided puncture balloon inflation. The unilateral puncture balloon inflation push increases the contralateral bone density. Although the amount of bone cement is less, it can effectively enhance the support force of the injured vertebra and achieve therapeutic effect. There was no significant height loss of the surgical vertebral body during the outpatient follow-up (Supplementary Table 1).
In this study, the cement leakage in the unilateral level was not obviously more than that in the bilateral level. These complications may be related to the puncture errors, unclear images, and incorrect timing of cement perfusion. Besides, the incidence of bone cement leakage is related to the severity of vertebral fracture and the volume of balloon dilation. Most scholars believe that once the bone cement leakage is found, it is necessary to stop the injection immediately.
This study has certain limitations. First, we enrolled a relatively small number of patients. Therefore, a consecutive study is required. Second, although osteoporosis can be due to many causes before PKP, we were unable to investigate whether the cause of osteoporosis has an effect on PKP. Thus, the effect of the causes of osteoporosis was not considered in the present study.