Failed less invasive lumbar spine surgery as a predictor of subsequent fusion outcomes.

PURPOSE: It is not uncommon for patients to undergo less invasive spine surgery (LISS) prior to succumbing to lumbar fusion; however, the effect of failed LISS on subsequent fusion outcomes is relatively unknown. The aim of this study was to test the hypothesis that patients who suffered failed LISS would afford inferior subsequent fusion outcomes when compared to patients who did not have prior LISS. METHODS: After IRB approval, registry from a spine surgeon was queried for consecutive patients who underwent fusion for intractable low back pain. The 47 qualifying patients were enrolled and split into two groups based upon a history for prior LISS: a prior surgery group (PSG) and a non-prior surgery group (nPSG). RESULTS: Typical postoperative outcome questionnaires, which were available in 80.9% of the patients (38/47) at an average time point of 40.4 months (range, 13.5-66.1 months), were comparatively analysed and failed to demonstrate significant difference between the groups, e.g. PSG v. nPSG: ODI--14.6 ± 10.9 vs. 17.2 ± 19.4 (P = 0.60); SF12-PCS--10.9 ± 11.0 vs. 8.7 ± 12.4 (p = 0.59); bNRS--3.0 (range -2-7) vs. 2.0 (range -3-8) (p = 0.91). Patient satisfaction, return to work rates, peri-operative complications, success of fusion and rate of revision surgery were also not different. CONCLUSIONS: Although limited by size and retrospective design, the results of this rare investigation suggest that patients who experience a failed LISS prior to undergoing fusion will not suffer inferior fusion outcomes when compared to patients who did not undergo prior LISS.

Recombinant human bone morphogenetic protein-2-augmented transforaminal lumbar interbody fusion for the treatment of chronic low back pain secondary to the homogeneous diagnosis of discogenic pain syndrome: two-year outcomes.

STUDY DESIGN: A retrospective observational study. OBJECTIVE: To assess clinical outcomes, perioperative complications, revision surgery rates, and recombinant human bone morphogenetic protein-2 (BMP-2)-related osteolysis, heterotopic bone, and unexplained postoperative radiculitis (BMPP) in a group of patients treated with BMP-2-augmented transforaminal lumbar interbody fusion (bTLIF) for the homogeneous diagnosis of discogenic pain syndrome (DPS) and to put forth the algorithm used to make the diagnosis. SUMMARY OF BACKGROUND DATA: There is a paucity of literature describing outcomes of TLIF for the homogeneous diagnosis of DPS, an old but controversial member of the lumbar degenerative disease family. METHODS: The registry from a single surgeon was queried for patients who had undergone bTLIF for the homogeneous diagnosis of DPS, which was made via specific diagnostic algorithm. Clinical outcomes were determined by analyzing point improvement from typical outcome questionnaires and the data from Patient Satisfaction and Return to Work questionnaires. Independent record review was used to assess all outcomes. RESULTS: Eighty percent of the cohort (36/45) completed preoperative and postoperative outcome questionnaires at an average follow-up of 41.9 ± 11.9 months, which demonstrated significant clinical improvement: Oswestry Disability Index = 16.4 (P < 0.0001), 12-Item Short Form Health Survey physical component summary score = 10.0 (P < 0.0001), and a Numeric Rating Scale for back pain = 2.3 (P < 0.0001). The median patient satisfaction score was 9.0 (10 = complete satisfaction), and 84.4% (27/32) of the cohort were able to return to their preoperative job, with or without modification. There were 3 perioperative complications, 4 revision surgical procedures, and 11 cases of benign BMPP. There were no incidents of the intraoperative dural tears or nerve root injury, and litigation involvement (11/36, P > 0.17), preoperative depression (15/36, P > 0.19) or prior discectomy/decompression (14/36, P < 0.37) was not a predictor of outcomes. CONCLUSION: Although limited by retrospective design and small cohort, the results of this investigation suggest that bTLIF is a reasonable treatment option for patients who experience DPS and affords high patient satisfaction. A larger study is needed to confirm these findings. LEVEL OF EVIDENCE: 4.

Contaminant profiles in Southeast Asian immigrants consuming fish from polluted waters in northeastern Wisconsin.

Recent immigrants to the USA from Southeast Asia may be at higher risk of exposure to fish-borne contaminants including polychlorinated biphenyls (PCBs), p, p'-dichlorodiphenyldichloroethene (DDE) and methylmercury (MeHg) because of their propensity to engage in subsistence fishing. Exposure to contaminants was assessed in men and women of Hmong descent living in Green Bay, Wisconsin, where the Fox River and lower Green Bay are contaminated with PCBs, and to a lesser extent with mercury. Serum samples from 142 people were analyzed for PCBs and p,p'-DDE by capillary column gas chromatography with electron capture detection (ECD). Whole blood was analyzed for total mercury by cold vapor atomic absorption spectrometry and atomic fluorescence spectroscopy. Lipid-adjusted total PCB concentrations ranged from 8.7 to 3,091ng/g (full range of the data), with a geometric mean of 183.6ng/g (estimated after eliminating one outlier). DDE ranged from 0.3 to 7,083 (full range of the data) with a geometric mean of 449.8ng/g (estimated after eliminating two outliers). Men had higher PCB and DDE concentrations than women. Serum PCB concentrations were significantly correlated with fish consumption (r=0.43, p<0.0001), whereas DDE concentrations were not (r=0.09,p=0.29). Instead, serum DDE was strongly associated with the number of years spent in a Thai refugee camp before immigrating to the USA (r=0.60;p<0.0001). PCB congeners 138, 153, 118 and 180 accounted for a smaller percentage of the total PCBs than has been reported in other fish-eating populations, and several lightly chlorinated congeners were present in relatively large amounts. Mercury exposure was low in this population. In conclusion, Hmong immigrants in northeastern Wisconsin are at risk of elevated PCB exposure from consumption of locally caught fish. The pattern of exposure is somewhat different than patterns in other fish-eating populations, possibly due to use of Aroclor 1242 by the paper industry in this region.

Determination of volatile organic compounds in biological samples using headspace solid-phase microextraction and gas chromatography: toluene and styrene.

Epidemiological and laboratory investigations have shown that toluene and styrene are toxic compounds that lead to impairment of the nervous system. To quantitate toluene and styrene in biological samples, liquid-liquid phase, headspace (HS), and solid-phase microextraction (SPME) methods are generally used. Most of these methods are not sensitive enough for applications involving small sample volumes. Here, we present a method for quantitative analysis of low concentrations of styrene and toluene in very small volumes of biological samples using HS-SPME and gas chromatography (GC) equipped with a flame-ionization detector. The method was developed by optimizing operating parameters that affect the HS-SPME-GC process [i.e., desorption time (30 s), depth of the fiber in the GC injection port (3.7 cm), adsorption time (4 min), and adsorption temperature (room temperature)]. It has a wide range of linearity (0.5-500 ng/10 microL), high precision (coefficient of variation < 5%), good accuracy (deviation < 11%), and low detection limits of 0.13 and 0.08 ng/10 microL for styrene and toluene in serum, respectively. This analytical technique can be applied to the estimation of styrene and toluene in small volumes of biological fluids (blood, serum, and perilymph) and tissues of low lipid content (cochlea).