Related Experiment Video
Updated: May 9, 2026
Novel Mini-open Transforaminal Lumbar Interbody Fusion
Published on: June 6, 2025
Short-term and long-term outcomes of minimally invasive and open transforaminal lumbar interbody fusions: is there a
Jason S Cheng1, Priscilla Park, Hai Le
1Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA. chengja@neurosurg.ucsf.edu
Object:
Previous studies comparing minimally invasive transforaminal lumbar interbody fusion (MITLIF) with open TLIF have demonstrated that MITLIF reduces blood loss and decreases postoperative pain while preserving fusion rates and reducing complications. In this study, the authors wanted to compare outcomes of MITLIF with those of open TLIF to determine whether MITLIF also improves postoperative functional mobility and decreases the usage of pain medication.
Methods:
In total, 75 consecutive patients who underwent either single-level open TLIF or MITLIF at the University of California, San Francisco, between 2006 and 2011 were included, and patients were followed up for an average of 5.05 years. Fifty patients underwent MITLIF and 25 underwent open TLIF. Primary outcomes included administration of morphine-equivalent narcotics and functional status on postoperative Day 1. Secondary outcomes included operative characteristics, complications, long-term fusion rates, and visual analog scale (VAS) scores.
Results:
No statistically significant differences in age, sex, body mass index (BMI), level of disease, or surgical indication were detected between the open TLIF and MITLIF groups. Similarly, preoperative medication usage did not significantly differ between these groups. Intraoperatively, compared with TLIF, MITLIF resulted in decreased lengths of operation, lower blood loss, and fewer complications (p < 0.05). Total administration of morphine-equivalent pain medication in the hospital also tended to be lower in the MITLIF than in the TLIF group. Functional assessment by physical therapy on postoperative Day 1 demonstrated higher function in the MITLIF patients for transfer-related tasks, ambulatory ability, and distance walked than in the TLIF patients (p < 0.05). This translated to shorter inpatient hospitalizations (6.05 vs 4.8 days for open TLIF vs MITLIF patients, respectively, p = 0.006) and an average cost reduction of $3885 per MITLIF patient. Long-term fusion rates were 92% in the MITLIF group and 100% in the open TLIF group (p = 0.09). Preoperative VAS pain scores were 7.1 for the MITLIF patients and 7.6 for the TLIF patients (p = 0.26). At the last follow-up, the reported VAS pain score was 2.9 in the MITLIF patients and 3.5 in the open TLIF patients, but this difference was not statistically significant (p = 0.25). There was also no statistically significant difference in the degree change in this score (p = 0.44).
Conclusions:
The MITLIF approach achieves improved functional mobility, decreases the usage of postoperative pain medication, and significantly reduces cost compared with open TLIF while preserving long-term fusion rates. To the authors' knowledge, this is the first study comparing the postoperative usage of pain medication between treatments in the postoperative period before discharge.
Insights
Minimally invasive transforaminal lumbar interbody fusion (MITLIF) improves postoperative functional mobility and decreases pain medication use compared to open TLIF. This approach also reduces costs while maintaining fusion rates.
Area of Science:
- Neurosurgery
- Orthopedic Surgery
- Spinal Fusion Techniques
Background:
- Minimally invasive transforaminal lumbar interbody fusion (MITLIF) has shown promise in reducing blood loss and postoperative pain compared to open transforaminal lumbar interbody fusion (TLIF).
- Further investigation is needed to determine if MITLIF also offers advantages in functional recovery and pain management post-surgery.
Purpose of the Study:
- To compare the functional outcomes and postoperative pain medication requirements of MITLIF versus open TLIF.
- To evaluate secondary outcomes including operative characteristics, complications, and long-term fusion rates.
Main Methods:
- A retrospective study of 75 patients undergoing single-level open TLIF or MITLIF.
- Patients were followed for an average of 5.05 years, with primary outcomes assessed on postoperative Day 1 functional status and pain medication administration.
- Secondary outcomes included operative data, complications, fusion rates, and Visual Analog Scale (VAS) pain scores.
Main Results:
- MITLIF demonstrated significantly shorter operation times, reduced blood loss, and fewer complications compared to open TLIF.
- MITLIF patients exhibited superior functional mobility on postoperative Day 1, including transfers and ambulation, and had shorter hospitalizations.
- While long-term fusion rates were slightly lower in the MITLIF group (92% vs. 100%), VAS pain scores did not differ significantly between groups at the final follow-up.
Conclusions:
- MITLIF is a viable alternative to open TLIF, offering improved functional mobility and reduced pain medication usage.
- The minimally invasive approach leads to significant cost savings and shorter hospital stays without compromising long-term fusion rates.
- This study provides novel insights into the comparative postoperative pain medication usage between MITLIF and open TLIF prior to hospital discharge.
