Postoperative lumbar plexus injury after lumbar retroperitoneal transpsoas minimally invasive lateral interbody fusion.

STUDY DESIGN: Retrospective review. OBJECTIVE: To evaluate the motor and sensory deficit rate after the lumbar retroperitoneal transpsoas minimally invasive lateral interbody fusion (MIS LIF) by reviewing a single surgeon's experience. SUMMARY OF BACKGROUND DATA: The MIS LIF is an increasingly used alternative to traditional open anterior or posterior operations to treat a host of spinal disorders. It has many advantages, but the potential for immediate postoperative thigh numbness, pain, and potential motor weakness has been reported. Published rates range widely in part because previous studies have based patient outcomes on data from different surgeons using different techniques. METHODS: An institutional review board-approved, retrospective review of a prospectively collected database was conducted. Seventy-one consecutive patients who underwent this procedure between L1 and L5 during a 3-year period met criteria and were included. Postoperative clinical examinations immediately after surgery and during routine follow-up intervals were examined. RESULTS: There was a 19.1% (14/71) rate of immediate postoperative ipsilateral thigh numbness during the study period. The annual rates of numbness progressively decreased annually. There was a 26.1% (6/23), 25% (5/20), and 10.7% (3/28) rate for 2008, 2009, and 2010, respectively. All patients with numbness had a fusion construct that involved L4-L5. More than half the patients, 54.9% (39/71), had immediate postoperative ipsilateral iliopsoas or quadriceps weakness. Of these, the vast majority had resolution by 3 months (92.3%), and all had complete resolution by 2 years. CONCLUSION: The lumbar retroperitoneal transpsoas MIS LIF is a safe alternative to traditional open operations for many spinal conditions. As with most minimally invasive techniques, there is a learning curve to be overcome to minimize the risk of iatrogenic nerve injuries. Our refined technique of the MIS LIF during a 3-year period has led to a significant reduction of the incidence of postoperative numbness of nearly 60% (from 26.1%-10.7%).

Subsidence of polyetheretherketone intervertebral cages in minimally invasive lateral retroperitoneal transpsoas lumbar interbody fusion.

STUDY DESIGN: A retrospective review. OBJECTIVE: The objective is to evaluate subsidence related to minimally invasive lateral retroperitoneal lumbar interbody fusion by reviewing our experience with this procedure. SUMMARY OF BACKGROUND DATA: Polyetheretherketone intervertebral cages of different lengths, widths, and heights filled with various allograft types are commonly used as spacers in lumbar fusions. Subsidence is a potential complication. To date, there are no published reports specifically addressing subsidence, because it relates to a series of patients undergoing minimally invasive lateral retroperitoneal transpsoas lumbar interbody fusion. METHODS: An institutional review board-approved, retrospective review of a prospectively collected database was conducted. One hundred forty consecutive patients who underwent this procedure between L1 and L5 during a 2-year period were included. All patients had T scores of -2.5 or more. Postoperative radiographs during routine follow-ups were reviewed for subsidence, defined as any violation of the vertebral end plate. RESULTS: Radiographical subsidence occurred in 14.3% (20 of 140), whereas clinical subsidence occurred in 2.1%. Subsidence occurred in 8.8% (21 of 238) of levels fused. Construct length had a significant positive correlation with increasing subsidence rates. Subsidence rates decreased progressively with lower levels in the lumbar spine, but had a higher than expected rate at L4-L5. Subsidence rates of 14.1% (19 of 135) and 1.9% (2 of 103) were associated with 18-and 22-mm-wide cages, respectively. No significant trends were observed with cage lengths. Supplemental lateral plates had a higher rate of subsidence than bilateral pedicle screws. Subsidence occurred at the superior end plate 70% of the time. CONCLUSION: The use of wider intervertebral cages leads to a significantly lower rate of subsidence, but a longer cage does not necessarily offer a similar advantage. Wide cages are protective against subsidence, and the widest cages should be used whenever feasible for interbody fusion in the lumbar spine to protect indirect compression and promote arthrodesis.

Use of titanium expandable vertebral cages in cervical corpectomy.

We aimed to investigate the usefulness of titanium expandable cages for vertebral body reconstruction after anterior cervical corpectomy. The records of 29 patients treated with expandable titanium cages for a variety of indications were analysed retrospectively. There was evidence of fusion in all patients. There was no radiographic evidence of more than 4mm subsidence throughout the series. There were no hardware failures. Our results show that expandable titanium cages are safe and useful in anterior cervical corpectomies for providing adequate anterior column support and solid constructs without significant hardware complications or the risk and morbidity associated with the use of strut allograft or autograft.

Polyethylene glycol (PEG) hydrogel dural sealant and collagen dural graft matrix in transsphenoidal pituitary surgery for prevention of postoperative cerebrospinal fluid leaks.

Cerebrospinal fluid (CSF) rhinorrhea is the most common complication after transsphenoidal pituitary surgery. The authors compare their previous experience using an autologous fat graft and lumbar drain placement in 107 patients with their current technique of using a dural sealant and collagen matrix in 97 patients to prevent postoperative CSF leak after pituitary tumor resection. The failure rate for CSF leak repairs between the two groups was similar. The use of a dural sealant and collagen matrix, however, has the advantages of decreased length of hospital stay, decreased length of Intensive Care Unit stay, avoidance of the morbidity of an extra abdominal incision, and avoidance of the risks of lumbar CSF drainage.