Prognosis of Symptomatic Pseudarthrosis Observed at 1 Year After Lateral Lumbar Interbody Fusion

Abstract

Study Design. Retrospective cohort study.Objective. The aim of this study was to investigate the prognosis of symptomatic pseudarthrosis observed at 1 year after lateral lumbar interbody fusion (LLIF) surgery and to analyze the risk factors for persistent pseudarthrosis for 2 years postoperatively. Summary of Background Data. Few articles have evaluated the prognosis of symptomatic pseudarthrosis following LLIF surgery. Methods. One hundred fifty-two patients with a minimum follow-up of 2 years were screened. Fusion status was assessed at 1 year postoperatively, and unfused segments were reevaluated at 2 years postoperatively. Dynamic x-rays and computed tomography images were acquired to evaluate the fusion status. Demographic data were evaluated to identify the risk factors associated with persistent pseudarthrosis. Clinical outcomes, including the visual analog scale (VAS) for back/leg pain and the Oswestry disability index (ODI), were evaluated preoperatively and at 1 and 2 years postoperatively. Results. Symptomatic pseudarthrosis was detected in 42 patients at 1 year postoperatively. Among them, 23 patients (54.8%) exhibited solid bony fusion 2 years postoperatively without further intervention. Fourteen patients (33.3%) showed asymptomatic pseudarthrosis, and the remaining five patients (11.9%) showed symptomatic pseudarthrosis. Multivariable analysis showed that diabetes (adjusted odds ratio [OR]: 2.817, P ¼ 0.007), smoking (adjusted OR: 6.497, P ¼ 0.008), and fusion at more than three levels (adjusted OR: 2.525, P ¼ 0.031) were risk factors for persistent pseudarthrosis. Improvements in the VAS scores for back pain and ODI scores were significantly lower in the persistent pseudarthrosis group than in the final solid fusion group at 2 years postoperatively. Conclusion. It is not necessary to intervene for all patients in whom symptomatic pseudarthrosis is detected at 1 year postoperatively because only 11.9% of them will show persistent symptomatic pseudarthrosis. However, early revision surgery should be considered when severe symptomatic pseudarthrosis associated with diabetes, smoking, and fusion at more than three levels is present.

Lateral Lumbar Interbody Fusion With rhBMP-2 can Achieve High Fusion Rates in Adult Spine Deformity Surgeries

“…These authors also described multiple-level LLIFs, diabetes and smoking status as independent risk factors for pseudoarthrosis development. 41 Five patients in the pseudoarthrosis group had posterolateral fusion despite the features of pseudoarthrosis at the interbody fusion level. This finding might explain the asymptomatic status of these patients and underlines the importance of meticulous PLF to supplement anterior interbody fusion.…”

“…The mean follow-up duration for both study groups is over 4 years and the length of follow-up is reasonable to detect most of the pseudarthroses, although seven years of follow-up has been recommended in literature. 41 Nevertheless, 8 patients (4.4%) with asymptomatic pseudoarthroses could become symptomatic in the longer term or these unfused segments with the potential fibrous union and radiologically demonstrable pseudoarthrosis could subsequently ossify into a stiff segment. A similar observation was made by Jung et al 41 in their study of 152 patients treated with single or two-level LLIF which reported a pseudarthrosis rate of 27.6% (42/152) at 1-year follow-up, which decreased to 12.5% (19/152) at 2-year follow-up.…”

“…41 Nevertheless, 8 patients (4.4%) with asymptomatic pseudoarthroses could become symptomatic in the longer term or these unfused segments with the potential fibrous union and radiologically demonstrable pseudoarthrosis could subsequently ossify into a stiff segment. A similar observation was made by Jung et al 41 in their study of 152 patients treated with single or two-level LLIF which reported a pseudarthrosis rate of 27.6% (42/152) at 1-year follow-up, which decreased to 12.5% (19/152) at 2-year follow-up. Fourteen of these patients had asymptomatic, radiological pseudoarthrosis and 5 (3.2%) were symptomatic requiring re-operation.…”

The Modified 11-Item Frailty Index and Postoperative Outcomes in Patients Undergoing Lateral Lumbar Interbody Fusion

“…The LLIF procedure was performed as previously described 27–29 . A PEEK cage filled with cancellous allograft bone chips mixed with bone marrow was inserted in all patients.…”

“…The LLIF procedure was performed as previously described. [27][28][29] A PEEK cage filled with cancellous allograft bone chips mixed with bone marrow was inserted in all patients. After wound closure, the patient was repositioned prone for posterior fixation.…”