Life Expectancy and Metastatic Spine Scoring Systems: An Academic Institutional Experience.

STUDY DESIGN: A retrospective data collection study with application of metastatic spine scoring systems. OBJECTIVES: To apply the Tomita and revised Tokuhashi scoring systems to a surgical cohort at a single academic institution and analyze spine-related surgical morbidity and mortality rates. SUMMARY OF BACKGROUND DATA: Surgical management of metastatic spine patients requires tools that can accurately predict patient survival, as well as knowledge of morbidity and mortality rates. METHODS: An Oregon Health & Science University (OHSU) Spine Center surgical database was queried (years 2002-2010) to identify patients with an ICD-9 code indicative of metastatic spine disease. Patients whose only surgical treatment was vertebral augmentation were not included. Scatter plots of survival versus the Tomita and revised Tokuhashi metastatic spine scoring systems were statistically analyzed. Spine-related morbidity and mortality rates were calculated. RESULTS: Sixty-eight patients were identified: 45 patients' (30 male patients, mean age 45 y) medical records included operative, morbidity, and mortality statistic data and 38 (26 male patients, mean age 54 y) contained complete metastatic spine scoring system data. Of the 38 deceased spine metastatic patients, 8 had renal cell, 7 lung, 4 breast, 2 chondrosarcoma, 2 prostate, 11 other, and 4 unknown primary cancers. Linear regression analysis revealed R values of 0.2570 and 0.2009 for the revised Tokuhashi and Tomita scoring systems, respectively. Overall transfusion, infection, morbidity, and mortality rates were 33% and 9%, and 42% and 9%, respectively. CONCLUSIONS: Application of metastatic prognostic scoring systems to a retrospective surgical cohort revealed an overall poor correlation with the Tomita and revised Tokuhashi predictive survival models. Morbidity and mortality rates concur with those in the medical literature. This study underscores the difficulty in utilizing metastatic spine scoring systems to predict patient survival. We believe a scoring system based on cancer type is needed to account for changes in treatment paradigms with improved patient survival over time.

Is chemical incompatibility responsible for chondrocyte death induced by local anesthetics?

BACKGROUND: Chondrolysis associated with intra-articular administration of local anesthetics has been attributed to chondrocyte death induced by the local anesthetics. The mechanism of how the local anesthetics cause chondrocyte death is not clear. PURPOSE: This study was conducted to determine whether and how the local anesthetics cause chondrocyte death. STUDY DESIGN: Controlled laboratory study. METHODS: Bovine articular chondrocytes in suspension culture were treated for 1 hour with phosphate-buffered saline or phosphate-buffered saline/medium mixture (as controls); 1% lidocaine alone; 0.25% to 0.5% bupivacaine alone; phosphate-buffered saline with pH values of 4.5, 3.8, 3.4, and 2.4; or mixtures of the local anesthetics and cell culture medium or human synovial fluid. Chondrocyte viability was analyzed by flow cytometry using the LIVE/DEAD Viability/Cytotoxicity Kit. RESULTS: In 1% lidocaine-alone or 0.25% to 0.5% bupivacaine-alone groups, the rate of cell death was 11.8% to 13.3% of bovine articular chondrocytes, whereas the phosphate-buffered saline control had 8.4% of cell death. Increased chondrocyte death was only found when the pH value of phosphate-buffered saline dropped to < or = 3.4. In contrast, when bupivacaine was mixed with cell culture medium, needle-like crystals were formed, which was accompanied with 100% death of chondrocytes. Lidocaine did not form visible crystals when it was mixed with culture medium, but the mixtures caused death of over 96% of chondrocytes (P < .001). CONCLUSION: Less than 5% of chondrocyte death was attributable to the anesthetics when applied to the cells alone or in phosphate-buffered saline-diluted solution. Acidity (as low as pH 3.8) or epinephrine in the anesthetic solutions could not account for chondrocyte death. However, chemical incompatibility between the local anesthetics and cell culture medium or human synovial fluid may be the cause of chondrocyte death. CLINICAL RELEVANCE: Intra-articular administration of lidocaine and bupivacaine is not an indicated usage of either anesthetic, although such a usage has become a common practice. Physicians should be aware of the potential incompatibility of the drug and synovial fluid.