|Abstract / Summary|
Transforaminal lumbar interbody fusion (TLIF) is presently the most used method to achieve spine fusion worldwide. This dissertation have tried to measure and cover the most important aspects of this new treatment modality, which ethically should be an obligatory requirement for all new treatments considered for implementation in medical practice before introduced in a larger patient population. The aim of the present dissertation was to investigate TLIF as a new and rapidly growing spine fusion method compared to a standard instrumented posterior lumbar fusion (PLF) with special focus on functional outcome in a standard 2 years follow up and long-term follow up perspective in patients suffering from chronic low back pain due to degenerative lumbar disorders. Special focus was made to pain, pain localization, and level of pain. Due to restricted amount of resources in the community, economic considerations must be a part of the entire investigation covering new treatment modalities introduced to a population. Thus, in addition, it was evaluated weather TLIF is cost-effective compared to PLF. A Randomized Clinical Trial (RCT) was chosen in order to provide the strongest statistical evidence free of bias, which was validated in baseline characteristics .The studies presented in this thesis are still the first and only to offer an all-around analysis of the TLIF method in a prospective randomized trial in comparison to the gold standard, which is usually thought to be “an instrumented posterolateral fusion” (PLF), with regard to short- and long-term functional outcome. Also, looking into whether the method has negative effects in the form of new radiculopathy due to the cage insertion we find that our studies reveal new knowledge and important information about the method. The study was conducted without any economical support from the industry and hence free from economical bias. This further strengthens the message of our studies. The dissertation could not demonstrate a positive effect of the TLIF in patient-reported outcome measures over the current standard treatment, neither in the short- nor the long-term. The TLIF operation method resulted in prolonged surgery time and increased perioperative bleeding. The study showed that both treatments gave an improved quality of life in the study population of patients with degenerative lumbar disorders elected for surgical treatment. The improved quality of life achieved by the surgical intervention was still present 9 years after the index operation. The positive effect of surgery was less in patients who underwent additional surgery after the index operation. An increased incidence of new or permanent pain related to insertion of the cage or the special approach in the group of patients exposed to TLIF could not be detected. There was no evidence that TLIF improved health or lowered costs and thus increased health effect per used resource unit over that of PLF. Thus, the method was not cost-effective compared to a standard instrumented posterolateral fusion.
The interpretation of this thesis together with previously published literature of high quality should lead to a change in the interpretation of interbody fusions procedures and thus a decrease in the number of these procedures done worldwide.