Krzysztof Siemionow

The effects of age, sex, ethnicity, and spinal level on the rate of intervertebral disc degeneration: A review of 1712 intervertebral discs

Study Design. A gross anatomic and magnetic resonance imaging study of intervertebral disc (IVD) degeneration in fresh cadaveric lumbar spines. Objective. The purpose of this study was to find the rate of IVD degeneration. Summary of Background Data. Age, sex, race, and lumbar level are among some of the factors that play a role in IVD degeneration. The rate at which IVDs degenerate is unknown. Methods. Complete lumbar spine segments (T11/T12 to S1) were received within 24 hours of death. The nucleus pulposus, anulus fibrosus, cartilaginous and bony endplate, and the peripheral vertebral body were assessed with magnetic resonance imaging and IVD degeneration was graded by two observers from grade 1 (nondegenerated) to grade 5 (severely degenerated) on the basis of a scale developed by Tanaka et al. The specimens were then sectioned and gross anatomic evaluation was performed according to Thompson et al. Results. A total of 433 donors and 1712 IVDs were analyzed. There were 366 whites, 47 Africans, 16 Hispanics, 4 Asian. There were 306 male and 127 female donors. The age range was 14 to 81 years, (average: 60.5 ± 11.3). For donors greater than age 40, the L5/S1 IVD degenerated at a significantly faster rate of 0.043 per year compared to 0.031, 0.034, 0.033, 0.027 for L1/L2, L2/L3, L3/L4, L4/L5, respectively. For donors younger than 40, L5/S1 IVD degenerated at a significantly faster rate of 0.141/y compared to 0.033, 0.021, 0.031, 0.050 for L1/L2, L2/L3, L3/L4, L4/L5, respectively. Multiple regression analysis revealed that sex had no significant effect on IVD degeneration whereas African ethnicity was associated with lower Thompson score at L1/L2, L2/L3, L3/L4, L4/L5 when compared with whites. Conclusion. The relatively early degeneration at L5–S1 in all races and lower Thompson grade in donors of African ethnicity needs further investigation. Factors such as sagittal alignment, facet joint arthritis, and genetics potentially play a role in IVD degeneration.

Conventional versus epineural sleeve neurorrhaphy technique: Functional and histomorphometric analysis

Three methods of nerve repair involving the epineural sleeve technique were compared with conventional nerve repair using the rat sciatic nerve transection model in four groups. In group 1, the sciatic nerve was repaired using the conventional epineural technique by placing four sutures. In groups 2, 3, and 4, the epineural sleeve technique was combined with two sutures, fibrin glue, and two sutures with fibrin glue, respectively. Functional recovery was evaluated using walking track analysis, limb circumference, and the severity of toe contracture. Diameter of the sciatic nerve fibers, total number of myelinated fibers, diameter of the myelin sheath, and the axon-to-fiber diameter ratio were measured at 12 weeks. The results showed better functional recovery as well as a higher number of myelinated fibers in groups using the epineural sleeve technique compared with conventional technique (p < 0.05). The addition of fibrin glue, however, did not make any significant difference. The epineural sleeve technique was found to be superior when compared with conventional nerve repair, providing faster functional recovery and improved nerve regeneration.

Epineural sleeve neurorrhaphy: surgical technique and functional results--a preliminary report.

This study was conducted to evaluate the effect of epineural sleeve neurorrhaphy on peripheral nerve regeneration. A total of 12 Lewis rats were divided in two groups of 6 rats each. In group 1, the rat sciatic nerve was transected and repaired using the conventional epineural technique with four sutures. In group 2, the epineural sleeve technique was introduced with two sutures only. Functional recovery was evaluated at 1, 2, 4, 8, and 12 weeks by walking track analysis (sciatic function index [SFI]), mean limb circumference ratio, and severity of toe contracture. Although the SFI at 12 weeks revealed no difference between the two groups (−88.39 ± 10.75 conventional group, −77.35 ± 17.06 epineural sleeve group), significant differences in SFIs were detected at 4 and 8 weeks, with better functional recovery in group 2 rats (4 weeks: 125.92 ± 22.73 conventional group, −99.17 ± 5.45 epineural sleeve group; 8 weeks: −96.65 ± 4.73 conventional group, −72.82 ± 17.11 epineural group;p < 0.05 for both time points). Mean limb circumference ratio was not significant at all time points. At 12 weeks, all animals in the conventional nerve repair group developed severe toe contractures whereas only 2 animals in epineural sleeve repair group had contracture (p < 0.05). In this study, the epineural sleeve technique demonstrated a faster functional recovery when compared with the conventional technique, as confirmed by SFI and toe contracture grading.Siemionow M, Tetik C, Ozer K, Ayhan S, Siemionow K, Browne E. Epineural sleeve neurorrhaphy: surgical technique and functional results—a preliminary report.

The effects of inflammation on glial fibrillary acidic protein expression in satellite cells of the dorsal root ganglion

Study Design. After undergoing L5 hemilaminectomy, chromic gut suture was placed onto the DRG and the animals were sacrificed at various time-points. Objective. The purpose of this study was to identify the effects of inflammation on satellite cells (SCs) of the dorsal root ganglion (DRG) by analyzing glial fibrillary acidic protein (GFAP) expression in of the DRG at various time points. Summary of Background Data. SCs are neuroglial cells that closely interact with nerve cells of the DRG. The role of SC remains unknown GFAP expression increases in response to CNS injury. Loss of GFAP has impaired Schwann cell proliferation and delayed nerve regeneration after injury. Methods. Sixty rats underwent a left L5 hemilaminectomy. In Group I, a chromic-gut suture was place topically on the DRG (n = 30), Group II was the sham surgery group (n = 30). DRGs were harvested at 6, 24, 48, 72 hours, and 7 days after surgery. In Group III, 6 control rats were killed and their bilateral L5 DRG harvested. The harvested DRG were analyzed using light microscopy for SC immunoreactivity, using GFAP, HIS-36, TNF-&agr;, IL-1&agr;, IL-1&bgr;, IL-6 monoclonal antibodies. Results. One hundred thirty-two DRGs were harvested for analysis. Naïve controls and neurons did not express GFAP. The SC sheath expressed GFAP as early as 6 hours postchromic gut application. In Group I, GFAP expression steadily increased after chromic-gut application with 100% of SC soma and SC sheaths being GFAP positive at 7 days. The contralateral DRG demonstrated delayed GFAP expression, with 83% of SC soma and SC sheaths were GFAP positive at 7 days. In Group II, 89% of sacs expressed GFAP by 7 compared to 79% in the contralateral undisturbed DRG. Conclusion. Under physiologic conditions, the expression of GFAP by SCs is undetectable. As the inflammatory process develops, GFAP expression steadily increases with 100% of SCs being GFAP immunoreactive 7 days after chromic gut application. These data suggest that SCs are the primary source of GFAP in the DRG. We hypothesize that SC play an important role in the response to early inflammatory injury.

Predictive factors of hospital stay in patients undergoing minimally invasive transforaminal lumbar interbody fusion and instrumentation.

Study Design. A single-center retrospective study. Objective. To identify predictors of length of stay (LOS) days in patients undergoing 1 level minimally invasive (MIS) transforaminal lumbar interbody fusions (TLIF). Summary of Background Data. Recent studies suggest intraoperative fluid administration, and colloid and crystalloid administration among other intraoperative variables may prolong LOS days and increase complications. Therefore, an understanding of which preoperative, intraoperative, and immediate postoperative parameters best predict immediate LOS days will help risk stratify patients and guide decision making. Methods. We retrospectively reviewed 104 patients undergoing a MIS TLIF at 1 institution between 2008 and 2010. Two groups were selected on the basis of the time of discharge. Group 1 consisted of patients discharged within 24 hours after surgery and group 2 consisted of patients discharged more than 24 hours after surgery. Multiple regression analysis was performed to determine which preoperative, intraoperative, and postoperative variables were independent predictors of LOS days. Results. Seventy-eight patients (75%) with a LOS greater than 24 hours had significantly higher estimated blood loss, received more crystalloids, had higher total fluids, longer surgical time, lower end of case temperature, lower hemoglobin during hospitalization, and a lower preoperative narcotic use. Multiple regression analysis showed that significant predictors of increased LOS were postoperative creatinine, visual analogue scale score, intraoperative colloids, fluids input at the end of surgical case, crystalloid to colloid ratio, fluid balance, oxycodone (Oxycontin) use, mean percentage of fraction of inspired oxygen, and preoperative hemoglobin. Conclusion. Patients undergoing 1 level MIS TLIF for degenerative conditions can overall expect a short LOS postoperatively. Multiple preoperative, intraoperative, and immediate postoperative factors can prolong the LOS in this group. This information should help the surgical team in optimizing their intraoperative patient management.

When back pain is not benign. A concise guide to differential diagnosis.

PREVIEW When back pain does not improve over time with standard treatment measures, there is often the fear that a serious but unrecognized underlying condition may be to blame. Proper evaluation to determine the cause of the back pain can ease the patients mind and guide rehabilitation. In this article, Drs Siemionow and McLain discuss the characteristic signs and symptoms of the most common serious causes of unremitting back pain, as well as the appropriate methods to establish a diagnosis.