Does a Preoperative Mental Health Diagnosis Affect Pain Management in Patients With Adolescent Idiopathic Scoliosis Undergoing Surgery?

BACKGROUND: Patients with adolescent idiopathic scoliosis (AIS) are typically treated surgically with posterior spinal fusion (PSF) when the curve continues to progress beyond 45 to 50 degrees. In adult patients, studies have shown that preoperative psychiatric diagnoses are associated with poorer clinical outcomes after lumbar spine surgery. This study aims to address whether a preoperative mental health disorder affects outcomes in pediatric patients with AIS treated with PSF. METHODS: We conducted a retrospective study of pediatric patients with a history of AIS requiring operative treatment with PSF at a single center with a minimum of 2-year follow-up. These patients were split into 2 groups: a subset that had a mental health disorder (MHD), and a control group. The MHD subset included patients with anxiety disorder, major depressive disorder, bipolar disorder, manic disorder, obsessive-compulsive disorder, attention deficit hyperactivity disorder, and stress disorder. The 2 groups were compared using independent student t -test and χ 2 analysis. RESULTS: A total of 417 patients were included in the study. Ninety-three patients were included in the MHD group, and 324 patients were included in the control group. The mean pain score for the MHD group was greater (3.93) compared with the control group (3.34). The PCA demands during inpatient stay for the MHD group were also greater (236.7) compared with the control group (140.0). There was no significant difference in the length of stay in the hospital between the MHD group (4.7 days) and the control group (4.6 days). There was a greater number of patients in the MHD cohort (25.8%) still using narcotic pain medication at first follow-up compared with the control group (12.0%). CONCLUSION: This study suggests that patients with AIS with a preoperative mental health disorder undergoing PSF experience more pain after surgery and require more pain medication during their recovery. LEVEL OF EVIDENCE: III. This is a retrospective review of pediatric patients with adolescent idiopathic scoliosis and a preoperative mental health diagnosis and their pain management requirements during the recovery period from posterior spinal fusion.

No Deficits in Functional Outcomes of the Contralateral Limb Are Seen When the Hamstring Is Harvested for Augmentation of Small Diameter Ipsilateral Hamstring Autograft.

Purpose: To evaluate clinical outcomes of the contralateral, nonoperative limb in patients undergoing contralateral hamstring (HS) autograft harvest compared with patients undergoing ipsilateral HS autograft harvest alone. Methods: This study included 96 patients who underwent isolated anterior cruciate ligament reconstruction (ACLR) using 4-stranded HS autograft (n = 85) or 4-stranded HS autograft augmented with contralateral HS (n = 13) due to inclusion of ipsilateral graft diameter <8 mm. Isokinetic flexion and extension strength and dynamic performance of the ipsilateral and contralateral limbs and limb symmetry index (LSI) were evaluated at 6 months' postoperatively. Rates of contralateral native ACL tear at minimum 2 years also were compared. For all comparisons, P < .05 was considered statistically significant. Results: Normalized isokinetic knee flexion and extension strength of the contralateral limb did not differ between cohorts (P = .34; P = .21, respectively). LSI for knee extension peak torque and knee flexion peak torque did not differ between cohorts (P = .44; P = .67, respectively). No difference in LSI was seen for any dynamic performance testing (single leg hop, P = .97; triple leg hop, P = .14; 6-m timed hop, P = .99). No difference was observed in International Knee Documentation Committee (P = .99) or Knee Injury and Osteoarthritis Outcome Score subscale measures (P = .39-.86). No difference in rates of contralateral knee native ACL tears were seen between cohorts (HS autograft + contralateral HS augmentation, n = 2, 15.4%; HS autograft, n = 7, 8.4%; P = .26). Conclusions: In this study, at the time of return to sport, we found no differences in contralateral limb functional performance or limb symmetry measurements between patients undergoing contralateral HS autograft harvest for augmentation of smaller (<8 mm) diameter HS autografts harvested from the injured extremity. Level of Evidence: Level III, retrospective cohort study.

Production of medical radioisotopes with linear accelerators.

In this study, we discuss producing radioisotopes using linear electron accelerators and address production and separation issues of photoneutron (γ,n) and photoproton (γ,p) reactions. While (γ,n) reactions typically result in greater yields, separating product nuclides from the target is challenging since the chemical properties of both are the same. Yields of (γ,p) reactions are typically lower than (γ,n) ones, however they have the advantage that target and product nuclides belong to different chemical species so their separation is often not such an intricate problem. In this paper we consider two examples, (100)Mo(γ,n)(99)Mo and (68)Zn(γ,p)(67)Cu, of photonuclear reactions. Monte-Carlo simulations of the yields are benchmarked with experimental data obtained at the Idaho Accelerator Center using a 44MeV linear electron accelerator. We propose using a kinematic recoil method for photoneutron production. This technique requires (100)Mo target material to be in the form of nanoparticles coated with a catcher material. During irradiation, (99)Mo atoms recoil and get trapped in the coating layer. After irradiation, the coating is dissolved and (99)Mo is collected. At the same time, (100)Mo nanoparticles can be reused. For the photoproduction method, (67)Cu can be separated from the target nuclides, (68)Zn, using standard exchange chromatography methods. Monte-Carlo simulations were performed and the (99)Mo activity was predicted to be about 7MBq/(g(⁎)kW(⁎)h) while (67)Cu activity was predicted to be about 1MBq/(g(⁎)kW(⁎)h). Experimental data confirm the predicted activity for both cases which proves that photonuclear reactions can be used to produce radioisotopes. Lists of medical isotopes which might be obtained using photonuclear reactions have been compiled and are included as well.

Long-term variations in the surface air 7Be concentration and climatic changes.

We have used EML Surface Air Sampling Program (SASP) data to analyze the long-term trend in (7)Be surface concentration and address possible correlation between this long-term trend and climatic changes, namely changes in precipitation patterns and temperature. In this paper we present (7)Be concentration data from 23 sites, spanning over 25 years, all over the world, and extract long-term trend parameter using two independent techniques. The (7)Be concentrations in most stations show a pronounced decreasing trend, potentially corresponding to statistically significant changes in transporting (7)Be from upper atmosphere source to these sites. Weak negative correlation between (7)Be concentration and amount of precipitation was also observed. However, more data from more representative sites around the world are needed the statistical robustness of this trend.

Extremely radiation-resistant mutants of a halophilic archaeon with increased single-stranded DNA-binding protein (RPA) gene expression.

Extremely halophilic archaea are highly resistant to multiple stressors, including radiation, desiccation and salinity. To study the basis of stress resistance and determine the maximum tolerance to ionizing radiation, we exposed cultures of the model halophile Halobacterium sp. NRC-1 to four cycles of irradiation with high doses of 18-20 MeV electrons. Two independently obtained mutants displayed an LD(50) > 11 kGy, which is higher than the LD(50) of the extremely radiation-resistant bacterium Deinococcus radiodurans. Whole-genome transcriptome analysis comparing the mutants to the parental wild-type strain revealed up-regulation of an operon containing two single-stranded DNA-binding protein (RPA) genes, VNG2160 (rfa3) and VNG2162, and a third gene of unknown function, VNG2163. The putative transcription start site for the rfa3 operon was mapped approximately 40 bp upstream of the ATG start codon, and a classical TATA-box motif was found centered about 25 bp further upstream. We propose that RPA facilitates DNA repair machinery and/or protects repair intermediates to maximize the ionizing radiation resistance of this archaeon.

Bystander effects in unicellular organisms.

Radiation-induced bystander effects have been seen in mammalian cells from diverse origins. These effects can be transmitted through the medium to cells not present at the time of irradiation. We have developed an assay for detecting bystander effects in the unicellular eukaryote, the fission yeast Schizosaccharomyces pombe. This assay allows maximal exposure of unirradiated cells to cells that have received electron beam irradiation. S. pombe cells were irradiated with 16-18 MeV electrons from a pulsed electron LINAC. When survival of the irradiated cells decreased to approximately 50%, forward-mutation to 2-deoxy-d-glucose resistance increased in the unirradiated bystander cells. Further increase in dose had no additional effect on this increase. In order to detect this response, it was necessary for the irradiated cell/unirradiated cell ratio to be high. Other cellular stresses, such as heat treatment, UV irradiation, and bleomycin exposure, also caused a detectable response in untreated cells grown with the treated cells. We discuss evolutionary implications of these results.