Correlation Between Mendelian Rescessive Traits and the Resistance to Fibrosarcoma in Mice

[From the Summary] 1. A correlation between tumor resistance, as measured by the latency period and the percentage of animals acquiring tumors, and the number of recessive genes in the genotypic makeup has been investigated with methylcholanthrene-induced tumors in mice. 2. Evidence is presented which points to the fact that recessive genes impart more resistance than dominant ones. In addition, the relationship seems to be an additive phenomenon, i.e., the more recessive genes in the makeup of the animal, the greater the resistance. 3. The results of this study are discussed in light of the findings of various other investigators, and these seem to fit in well with their findings. 4. A speculative hypothesis of mechanism is presented and discussed

Complications And Length Of Stay Following Spine Surgery: Analyzing Local And National Cohorts

Complications following spine surgery are widely reported but poorly characterized. The effect of preoperative comorbidities and postoperative complications on length of stay (LOS) has not been evaluated. It would be ideal to have a clearer understanding of the variables affecting LOS to facilitate setting expectations and control costs. Using complications and LOS as outcomes, we can also characterize the risks inherent with surgical practices, such as the use of iliac crest bone graph (ICBG) in spinal fusion. The study consisted of three aspects. First, the effect of pre and perioperative variables on LOS for 103 patients undergoing posterior lumbar fusion at Yale was examined. Next, the National Surgical Quality Improvement Program (NSQIP) database was used to determine the variables associated with extended LOS and complications following 2,164 anterior cervical discectomy and fusion (ACDF) procedures. Finally, 13,927 spinal fusion cases from the NSQIP database were analyzed to determine the effect of harvesting ICBG on operative time, complications, LOS, and readmission. Multivariate analysis was used throughout the study to control for confounding while evaluating statistical significance. For lumbar fusion, average LOS was 3.6 ± 1.8 days. 79% had a stay of four days or less. Preoperative variables associated with increased LOS were age and ASA score. Heart disease was significantly associated with decreased LOS. Postoperative complications occurred in 32% of patients and led to a LOS of 5.1 ± 2.3 days vs. 2.9 ± 0.9 days for patients with no complication. For ACDF, average LOS was 2.0 ± 4.0. Age ≥ 65, functional status, transfer from facility, preoperative anemia, and diabetes were the preoperative factors predictive of extended LOS. Major complications, minor complications, and extended surgery time were the perioperative factors associated with increased LOS. 71 (3.3%) had a total of 92 major complications. ASA score ≥ 3, preoperative anemia, age ≥ 65, extended surgery time and male gender were predictive of major complications. Meanwhile, postoperative blood transfusion (OR 1.5), extended operative time (+ 22.0 min) and LOS (+0.2 days) were significantly associated with ICBG use. After lumbar fusion, patients that are older and have widespread systemic disease tend have longer LOS, but no single comorbidity was predictive of LOS. After ACDF, 1 in 33 patients develops a major post-operative complication, which are associated with an increased LOS of 5 days. Current ICBG usage in spinal fusion is low, with rates between 3.4% and 12.4% depending on approach. Use of ICBG is associated with extended operative time, extended LOS, and postoperative blood transfusion

Propionibacterium acnes infections in patients with idiopathic scoliosis: a case-control study and review of the literature.

Purpose:Surgical site infection (SSI) caused by Propionibacterium acnes is an infrequent but devastating complication after spinal fusion. The purpose of this study was to identify risk factors for SSI with Propionibacterium acnes after spinal fusion for juvenile and adolescent idiopathic scoliosis (JIS and AIS). Methods:A case-control study was performed. Each case was matched 2:1 for age, gender and diagnosis. Retrospective chart review was performed to obtain relevant demographic, surgical and clinical data for all cases and controls. Statistical analysis included paired t-test and McNemar test, as well as exact logistic regression and robust regression models. Results:This study included ten infection cases (eight AIS, two JIS) and 20 controls (16 AIS, four JIS). In total, six infected cases presented within two weeks of the index procedure (acute infection) and four infected cases presented more than one year from the index procedure (delayed infection). The most common presentation for acute infections was wound drainage, while back pain was more common in delayed infections. All infections were successfully treated with surgical irrigation and debridement and postoperative antibiotics. Hardware was removed for patients with delayed infections. The strongest risk factor for infection was increased requirement for blood transfusion, but it did not reach statistical significance. Conclusion:SSI with Propionibacterium acnes is an important complication after spinal fusion for idiopathic scoliosis. These infections can be successfully treated, but larger studies are needed to further identify risk factors and establish standardized guidelines for the treatment and prevention of this complication. Level of Evidence Level III

The effect of iliac crest autograft on the outcome of fusion in the setting of degenerative spondylolisthesis: a subgroup analysis of the Spine Patient Outcomes Research Trial (SPORT).

BACKGROUND: There is considerable controversy about the long-term morbidity associated with the use of posterior autologous iliac crest bone graft for lumbar spine fusion procedures compared with the use of bone-graft substitutes. The hypothesis of this study was that there is no long-term difference in outcome for patients who had posterior lumbar fusion with or without iliac crest autograft. METHODS: The study population includes patients enrolled in the degenerative spondylolisthesis cohort of the Spine Patient Outcomes Research Trial who underwent lumbar spinal fusion. Patients were divided according to whether they had or had not received posterior autologous iliac crest bone graft. RESULTS: There were 108 patients who had fusion with iliac crest autograft and 246 who had fusion without iliac crest autograft. There were no baseline differences between groups in demographic characteristics, comorbidities, or baseline clinical scores. At baseline, the group that received iliac crest bone graft had an increased percentage of patients who had multilevel fusions (32% versus 21%; p=0.033) and L5-S1 surgery (37% versus 26%; p=0.031) compared with the group without iliac crest autograft. Operative time was higher in the iliac crest bone-graft group (233.4 versus 200.9 minutes; p CONCLUSIONS: The outcome scores associated with the use of posterior iliac crest bone graft for lumbar spinal fusion were not significantly lower than those after fusion without iliac crest autograft. Conversely, iliac crest bone-grafting was not associated with an increase in the complication rates or rates of reoperation. On the basis of these results, surgeons may choose to use iliac crest bone graft on a case-by-case basis for lumbar spinal fusion

Cartilage restoration of patellofemoral lesions: a systematic review

Purpose This study aimed to systematically analyze the postoperative clinical, functional, and imaging outcomes, complications, reoperations, and failures following patellofemoral cartilage restoration surgery. Methods This review was conducted according to the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). PubMed, EMBASE, and Cochrane Library databases were searched up to August 31, 2018, to identify clinical studies that assessed surgical outcomes of patellofemoral cartilage restoration surgery. The Methodological Index for Non-Randomized Studies (MINORS) was used to assess study quality. Results Forty-two studies were included comprising 1,311 knees (mean age of 33.7 years and 56% males) and 1,309 patellofemoral defects (891 patella, 254 trochlear, 95 bipolar, and 69 multiple defects, including the patella or trochlea) at a mean follow-up of 59.2 months. Restoration techniques included autologous chondrocyte implantation (56%), particulated juvenile allograft cartilage (12%), autologous matrix-induced chondrogenesis (9%), osteochondral autologous transplantation (9%), and osteochondral allograft transplantation (7%). Significant improvement in at least one score was present in almost all studies and these surpassed the minimal clinically important difference threshold. There was a weighted 19%, 35%, and 6% rate of reported complications, reoperations, and failures, respectively. Concomitant patellofemoral surgery (51% of patients) mostly did not lead to statistically different postoperative outcomes. Conclusion Numerous patellofemoral restoration techniques result in significant functional improvement with a low rate of failure. No definitive conclusions could be made to determine the best surgical technique since comparative studies on this topic are rare, and treatment choice should be made according to specific patient and defect characteristics

Enhanced Recovery after Surgery (ERAS) and its applicability for major spine surgery

This article examines the relevance of applying the Enhanced Recovery after Surgery (ERAS) approach to patients undergoing major spinal surgery. The history of ERAS, details of the components of the approach, and the underlying rationale are explained. Evidence on outcomes achieved by using the ERAS approach in other orthopaedic and complex surgical procedures are then outlined. Data on major spinal surgery rates and current practice are reviewed and the rationale for the use of ERAS in major spinal surgery is discussed, and potential challenges to its adoption acknowledged. A thorough literature search is then undertaken to examine the use of ERAS pathways in major spinal surgery, and the results presented. The article then reviews the evidence to support the application of individual ERAS components such as patient education, multimodal pain management, surgical approach, blood loss, nutrition, and physiotherapy in major spinal surgery, and discusses the need for further robust research to be undertaken. The article concludes that given the rising costs of surgery and levels of patient dissatisfaction, an ERAS pathway that focuses on optimizing clinical procedures by adopting evidence-based practice, and improving logistics, should enable major spinal surgery patients to recover more quickly with lower rates of morbidity and improved longer term outcomes