Lumbar Spine Diseases

In certain patients with lumbar spine diseases, specifically those experiencing clinical or radiographic instability, surgical treatment is essential. For cases without instability, decompression alone is often adequate, but conditions involving instability, particularly degenerative conditions, usually require spinal fusion.

The primary objectives of treatment are to achieve a solid fusion, correct deformities, indirectly decompress nerves, and provide stability. A range of surgical techniques have been developed to achieve spinal fusion, each with varying fusion rates and clinical outcomes.

These techniques encompass posterior fusion (PF), posterolateral fusion (PLF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), extreme lateral interbody fusion (XLIF), lateral lumbar interbody fusion (LLIF), and oblique lumbar interbody fusion (OLIF). Additionally, total disc replacement (TDR) is an alternative choice that enables patients to maintain spinal mobility.

PLIF was initially described as a minimally invasive surgical (MIS) approach to improve outcomes and clinical results in the peri-postoperative period. ALIF, originally utilized for tuberculosis of the spine, was later adapted for various other lumbar spine diseases. Subsequently, XLIF was introduced.

Systematic reviews that compared MIS-TLIF or open TLIF with other fusion techniques for lumbar spine diseases had been reported. The evidence is limited, requiring more randomized controlled trials (RCTs). The comparison of fusion rates, clinical outcomes, and complications remains inconclusive.

Through a systematic search, numerous articles have been reported in literature and identified and subsequently refined during the review process. Eventually, 18 randomized controlled trials (RCTs) that met the criteria were included.

Out of these, 15 RCTs comprising a total of 915 patients were analyzed. These studies investigated different fusion techniques and were published between 2013 and 2019. Follow-up periods varied, with some studies reporting outcomes at 1-year follow-up and others extending to at least a 2-year follow-up period.

The assessment of bias in the included randomized controlled trials (RCTs) indicated that the randomization process and deviations from intended interventions had a majority of low-risk instances. However, there were concerns about bias in the measurement of outcomes across all the RCTs.

Some studies also exhibited a high risk of bias in terms of deviations from intended interventions and the selection of reported result domains. Moreover, the absence of significant asymmetry in the funnel plots suggests no indication of publication bias in relation to fusion rate, total adverse events, and revision rate.

Operative Time

Compared to transforaminal lumbar interbody fusion (TLIF), anterior lumbar interbody fusion (ALIF), posterior lumbar fusion (PLF), and the no fusion groups generally have shorter operative times, while posterior lumbar interbody fusion (PLIF) tends to have longer operative times.

When comparing TLIF to other techniques (including no fusion, ALIF, PLF, PLIF, and XLIF), the combined analysis revealed a pooled mean difference in operative time of 31.88 minutes shorter than TLIF.

Blood Loss

PLIF typically results in greater blood loss compared to transforaminal lumbar interbody fusion (TLIF), with an average of 88.80 ml more blood loss. Among the groups studied (including no fusion, posterior lumbar fusion (PLF), and PLIF), the no fusion group tends to have the least blood loss. However, when pooling the mean difference in blood loss between these techniques, no significant difference was found.

Length of Hospital Stay

According to the literature, there is no significant difference in the length of hospital stay among the subgroups.

Back and Leg Pain

Back pain at the last follow-up does not differ significantly between the TLIF group and other technique groups, including the no fusion techniques. The no fusion techniques were associated with less back pain at the last follow-up. Leg pain data from only two PLF studies were available, and there was no significant difference in leg pain at the last follow-up between the TLIF and PLF groups.

Surgical intervention becomes necessary for patients with degenerative lumbar spine disease when conservative treatments prove ineffective. However, the choice of operative methods can vary among spine surgeons, resulting in variations in reported fusion rates and clinical outcomes across different studies.

This systematic review and meta-analysis aimed to assess the benefits and risks associated with lumbar interbody fusion, no fusion, and posterolateral fusion. By comparing fusion rates, clinical outcomes, operation-related parameters, and complications, the analysis aimed to provide a better understanding of the effectiveness and potential drawbacks of these treatment approaches.

PLIF surgical techniques varied across studies, with some lacking specific details. Putzier et al. used a midline approach with bilateral cages, while Yang et al. performed PLIF with rectangular cages and bone grafts. ALIF involved a retroperitoneal approach with a PEEK cage and screws. XLIF utilized a retroperitoneal approach similar to ALIF. Two RCTs had equal sample sizes and utilized previously described techniques. Direct decompression was not performed in XLIF patients.

Among the three randomized controlled trials (RCTs) focused on MIS-TLIF, two studies specifically examined open TLIF, while the third study did not provide details regarding the surgical procedure for TLIF. In our analysis, we grouped MIS-TLIF, open TLIF, and TLIF with unspecified details together for comparison of clinical outcomes and complications.

Notably, MIS-TLIF and open TLIF showed similar clinical outcomes based on previous studies. However, it should be noted that the comparison specifically between open TLIF and MIS-TLIF is beyond the scope of our current study.

The non-fusion group reported in literature had less back pain, while the fusion groups had similar back pain levels. There was no significant difference in ODI scores among the surgical techniques. At the last follow-up, the no fusion group had higher ODI scores compared to TLIF, suggesting potential increasing disability over time.

The no fusion group had shorter operative time and less blood loss due to less paravertebral dissection. PLIF had the longest operative time and more blood loss compared to TLIF, likely due to the more extensive posterior approach.

Currently, there are no significant differences in surgical complications, as total adverse events are assessed, among lumbar interbody fusion, no fusion, and posterolateral fusion. However, findings indicate that TLIF may be considered safer than PLIF and ALIF regarding neural, spinal, and vascular events. Literature has reported a higher occurrence of complications in the fusion group when compared to the non-fusion group.

The strength of including unbiased randomized controlled trials (RCTs) is evident in the examination of fusion rate, adverse events, and revision rate. However, limitations arise from the small number of TLIF-specific RCTs and heterogeneity in the enrolled studies.

Measures were taken to mitigate bias by excluding repeated data. It should be noted that treatment protocols and follow-up durations vary across the included studies, with a focus on single-level surgery.