Hsien-Ta Hsu

Learning curve of full-endoscopic lumbar discectomy

PurposeTo report the learning curve of full-endoscopic lumbar discectomy for a surgeon naive to endoscopic surgery but trained in open microdiscectomy.MethodsFrom July 2006 to July 2009, 57 patients underwent full-endoscopic lumbar discectomy and 66 underwent open microdiscectomy. The clinical results were evaluated with a visual analog scale (VAS) and the Oswestry Disability Index (ODI). Spearman’s coefficient of rank correlation (rho) was used to assess the learning curves for the transforaminal and interlaminar procedures of full-endoscopic lumbar discectomy.ResultsAfter full-endoscopic lumbar discectomy, the VAS and ODI results of the patients followed up were comparable with those of open microdiscectomy. A steep learning curve was observed for the transforaminal procedure, but not the interlaminar procedure.ConclusionsThe learning curve of the transforaminal approach was steep and easy to learn, while the learning curve of the interlaminar approach was flat and hard to master.

Zoledronic acid infusion for lumbar interbody fusion in osteoporosis.

BACKGROUND Clinical outcomes of intravenous (IV) infusion of zoledronic acid (ZOL) for lumbar interbody fusion surgery (LIFS) remain unknown. We investigated the efficacy of IV ZOL on clinical outcome and bone fusion after LIFS. MATERIALS AND METHODS We retrospectively analyzed 64 patients with both degenerative lumbar spondylolisthesis and osteoporosis who underwent LIFS from January 2007 to April 2010. All patients were followed up for 2 y. Thirty-two were treated with an IV infusion of ZOL 3 d after surgery and a second injection 1 y later, and the other 32 patients did not receive ZOL. Preoperatively and every 3 mo postoperatively, oswestry disability index questionnaire and visual analog scale (VAS) scores for back and leg were compared. Preoperative and final postoperative follow-up to evaluate for subsequent compression fractures were also performed. Pedicle screw loosening, cage subsidence, and fusion rate were documented 2 y after surgery. RESULTS At 2-y follow-up, a solid fusion was achieved in 75% of the ZOL group and only 56% of the control group. At final follow up, the incidence of final subsequent vertebral compression fractures (19% of the ZOL group and 51% of the control group, P = 0.006), pedicle screw loosening (18% of the ZOL group and 45% of the control group, P = 0.03), and cage subsidence >2 mm (28% of the ZOL group and only 54% of the control group, P = 0.04) were significantly lower in the ZOL group than in the control group. The ZOL group demonstrated improvement in VAS (for leg pain VAS, 2/10 for the ZOL group and 5/10 for the control group; for back pain VAS, 2/10 for the ZOL group and 6/10 for the control group) and oswestry disability index scores (7/25 for the ZOL group and 16/25 for the control group). CONCLUSIONS ZOL treatment has beneficial effects on instrumented LIFS both radiographic and clinically. Thus, ZOL treatment can be recommended for osteoporosis patients undergoing LIFS.

The Correlation between Restoration of Lumbar Lordosis and Surgical Outcome in the Treatment of Low-grade Lumbar Degenerative Spondylolisthesis with Spinal Fusion.

Study Design: Retrospective clinical study. Objective: To investigate the relationship between the restoration of the lumbar lordosis (LL) and the surgical outcome of patients undergoing spinal fusion for low-grade lumbar degenerative spondylolisthesis. Summary of Background Data: Correlation between low back pain and the loss of LL in the treatment of low-grade lumbar degenerative spondylolisthesis has seldom been reported. Methods: Between May 2005 and July 2011, 59 patients with low back pain and neurogenic claudication due to low-grade lumbar degenerative spondylolisthesis underwent spinal decompression and fusion by a senior surgeon. Ten patients were lost to follow-up. The mean age of the remaining 49 patients (10 men and 39 women) was 64.0 years (range, 47–88 y). Patients were categorized on the basis of the spino-pelvic posture: type 1 [pelvic incidence (PI)<45 degrees] (n=12), type 2 (45 degrees⩽PI⩽60 degrees) (n=24), and type 3 (PI>60 degrees) (n=13). The LL restoration ratio was calculated by the actual LL divided by the predicted LL. The clinical results were evaluated using a visual analogue scale and the Oswestry Disability Index. Postoperative 36-inch spinal films were used to assess the sagittal balance. Results: The mean follow-up period was 43.2 months (range, 28–62 mo). Forty-eight patients showed significant improvement with respect to visual analogue scale and Oswestry Disability Index regardless of whether the LL was restored higher or lower. Postoperative 36-inch spinal films showed the C7 plumb line to be within an average of 4.4 cm (range, 0.6–5.6 cm) from the posterior-superior corner of the S1 vertebrae. Conclusions: Patients with smaller PI tended to be restored higher, and those patients with a larger PI were more likely to be restored lower. For patients with normal sagittal balance, the surgical outcomes in the treatment of low-grade lumbar degenerative spondylolisthesis with spinal fusion are not correlated with restoration of the LL.

Correlation between lumbar lordosis and the treatment of chronic low back pain with pulsed radiofrequency applied to the L2 dorsal root ganglion

Background: Percutaneous pulsed radiofrequency (PRF) applied to the L2 dorsal root ganglion (DRG) is an alternative procedure for treating patients with chronic discogenic pain. It is assumed that afferent nerve fibers innervating the degenerated disc and facet joint might travel in the same pathway and finally enter into the L2 DRG. Blocking the L2 DRG with PRF might alleviate discogenic pain and facet joint pain concurrently. Purpose: The purpose of this study was to investigate the correlation between different types of lumbar lordosis (LL) and the treatment of chronic low back pain with PRF applied to the L2 DRG. Materials and Methods: Between 2008 and 2013, 84 patients (29 men and 55 women) were enrolled. Their mean age was 56.03 ± 9.04 years. All patients suffered from low back pain for more than 6 months that worsened on prolonged sitting or standing and did not improve with at least 3 months of conservative treatment. LL was classified into four types based on Roussoulys classification. The L2 DRG was blocked with 2-Hz PRF waves lasting for 120 s at 45 V with the temperature of the electrode tip not above 42°C. The functional outcomes were assessed pre- and post-operatively using a visual analog scale (VAS) and the Oswestry Disability Index (ODI). Results: Twenty-four patients were Type 1 LL, 26 were Type 2 LL, 21 were Type 3 LL, and 13 were Type 4 LL. The mean age of patients with each type of LL was type 1 (56.63 ± 12.09 years), Type 2 (55.39 ± 11.05 years), Type 3 (55.86 ± 11.40 years), and Type 4 (56.54 ± 12.73 years). There were similar improvements in the VAS and ODI scores for all LL types. Two patients experienced cerebrospinal fluid leakage when the needle was moved toward the L2 DRG, but neither patient experienced a neurological deficit. Conclusion: PRF applied to the L2 DRG is an alternative procedure for treating patients with chronic low back pain, regardless of which type of LL the patients have. Chronic low back pain, including discogenic pain and facet joint pain, may be treated by PRF applied to the L2 DRG.

Delayed Cervical Vertebral Body Osteoradionecrosis in a NasopharyngealCarcinoma Patient â Case Report

High dose radiotherapy is a treatment for nasopharyngeal carcinoma (NPC), but can result in radiation-induced changes to the cervical spine, which may be difficult to recognize. Pathological fractures occurring after radiation therapy for soft tissue tumors are rare. In this context, we report a rare case of delayed Osteoradionecrosis of a cervical vertebral body (C5) causing myeloradiculopathy. The patient, a 54-year-old man, received radical radiotherapy for NPC 10 years previously. Anterior decompression and stabilization with internal fixation was performed. Pathology reported necrotic tissue and no evidence of malignancy. Postoperatively, the patient’s neck pain improved, and he recovery muscle power in all four extremities. Early diagnosis is essential for this curable condition. Emergency surgical intervention for decompression and stabilization with internal fixation may result in complete neurological recovery.