Month: March 2026

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Postoperative loss in segmental lumbar lordosis following L5–S1 anterior lumbar interbody fusion

J Neurosurg Spine 44:420–425, 2026

This clinical study evaluates predictors and thresholds for postoperative loss of L5–S1 segmental lordosis following anterior lumbar interbody fusion (ALIF) in 94 adults treated for degenerative disc disease. Multivariate analyses identified baseline obesity, absence of posterior fixation, and larger immediate lordotic correction as independent predictors of 6-week to 1-year segmental lordosis loss, which related to higher rates of cage subsidence and revision.

The authors derived 6-week postoperative L5–S1 lordosis thresholds (overall range 21.6°–26.8°, PI-specific: low 19.0°–24.8°, average 21.0°–26.4°, high 24.1°–28.7°) that minimized subsequent loss and need for revision. Findings support targeted preoperative planning to achieve sustainable correction while balancing risks of overcorrection and subsidence.

Segmental Lordosis Restoration: L5–S1 anterior lumbar interbody fusion (ALIF) provides strong and durable correction of segmental lumbar lordosis and disc height, with most correction maintained at 1 year postoperatively.

Predictors of Lordosis Loss: Baseline obesity, lack of posterior fixation, and larger initial correction in L5–S1 lordosis are independent predictors of postoperative segmental lordosis loss within 1 year.

Complications: Loss of segmental lordosis increases the risk of cage subsidence and revision surgery, particularly due to pseudarthrosis.

Optimal Correction Thresholds: Achieving 6-week postoperative L5–S1 segmental lordosis between 21.6° and 26.8° minimizes the risk of lordotic loss and need for revision; PI-specific thresholds are 19.0°–24.8° (low PI), 21.0°–26.4° (average PI), and 24.1°–28.7° (high PI).

Risks of Overcorrection/Undercorrection: Overcorrection (>26.8°) increases risk of cage subsidence and mechanical complications, while undercorrection (<21.6°) may predispose to implant failure and adjacent segment disease.

Surgical Planning Importance: Preoperative planning should target lordosis correction within these thresholds and consider modifiable risk factors to optimize outcomes and reduce complications.

Comparison to Other Techniques: ALIF offers greater segmental correction than other lumbar interbody fusion techniques such as TLIF or XLIF.

Clinical Implications: Nearly half of patients experience some degree of lordosis loss post-ALIF, highlighting the need for careful patient selection, surgical technique, and postoperative monitoring.

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Microvascular Decompression for Patients With Type 1 Trigeminal Neuralgia Using Vein Sacrifice and a Teflon Transposition Technique: A 23-Year Cohort

Neurosurgery 98:588–596, 2026

This study reports outcomes from a 23-year, prospectively maintained cohort of 523 patients with unilateral Type 1 trigeminal neuralgia treated by microvascular decompression using vein sacrifice and a Teflon transposition technique. Primary outcome was long-term pain-free survival without medications, with median follow-up 8.2 years and 5-, 10-, 15-year pain-free rates of 77.6%, 72.5%, and 69.7%, respectively.

Operative details, complications, and reoperation rates are presented: arterial transposition was performed when possible, veins contacting the nerve were sacrificed, and Teflon pledgets used to maintain separation. Complications were uncommon and generally non-disabling (most frequent: facial numbness, diplopia); true Teflon granulomas were rare but noted in isolated reoperations.

Microvascular decompression (MVD) is the most effective surgical treatment for medically unresponsive Type 1 trigeminal neuralgia (TN), aiming to eliminate neurovascular contact with the trigeminal nerve using arterial transposition, vein sacrifice, and polytetrafluoroethylene (PTFE, “Teflon”) implantation when appropriate.

Study outcomes show that 92.7% of patients were initially pain-free without medications after MVD, with pain-free survival rates of 77.6% at 5 years, 72.5% at 10 years, and 69.7% at 15 years.

Operative technique selection depends on intraoperative findings: arteries are transposed and secured with PTFE whenever possible, veins in contact with the nerve are sacrificed, and partial sensory rhizotomy is reserved for cases without significant vascular compression.

Complication rates are low; the most common was new or worsened facial numbness (7.1%), with higher rates when veins were sacrificed (6.9%) versus arterial decompression alone (1.6%). Venous infarction occurred in 0.6% of patients, and Teflon granuloma in 0.4%.

Pain-free survival was lower in women (hazard ratio 1.48, P = .03), but not associated with pain duration, previous ablative surgery, or new facial numbness.

Vein sacrifice is generally safe and facilitates surgical exposure, though it carries a low but real risk of venous complications; evidence is mixed regarding whether preserving or sacrificing the superior petrosal vein impacts complication rates.

PTFE (“Teflon”) material is widely used for vessel transposition; however, true Teflon granulomas—characterized by mass effect, edema, and inflammatory response—are rare and should not be used to describe all cases of recurrent pain with adherent PTFE.

Terminology precision is important: “Teflon” is a trademark for Chemours’ PTFE products, and not all PTFE felt used in surgery is identical. Variability in material properties may affect surgical outcomes and study reproducibility.

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