Multimodal intraoperative monitoring: towards a routine use in surgical treatment of severe spinal disorders

European Spine Journal -     

Postoperative Expansion is not a Primary Cause of Infection in Immediate Breast Reconstruction with Tissue Expanders

Perioperative infection is the most common and dreaded complication associated with tissue expander (TE) breast reconstruction. Historically, the expansion period was thought to be the time of greatest hazard to the implant. However, recent institutional observations suggest infectious complications occur prior to expansion. This investigation, therefore, was conducted to determine the timing of infectious complications associated with two‐stage TE breast reconstructions. Following IRB approval, a retrospective review of all consecutive two‐stage immediate TE breast reconstructions at a single institution from November 2007 to November 2011 was conducted. Reconstructions were then divided into two cohorts: those suffering infectious complications and those that did not. Infectious complications including minor cellulitis, major cellulitis, abscess drainage, and explantation were identified. Various operative and patient variables were evaluated in comparison. Eight hundred ninety immediate two‐stage TE breast reconstructions met inclusion criteria. Patients suffering infection were older (55.4 years versus 49.3 years; p < 0.001), and more likely to have therapeutic mastectomy (94% versus 61%; p < 0.0001), the use of acellular dermal matrix (ADM; 72.5% versus 54.9%; p = 0.001), and greater initial TE fill (448.6 mL versus 404.7 mL; p = 0.0078). The average time to developing of infectious symptoms was 29.6 days (range 9–142 days), with 94.6% (n = 87) of infections prior to the start of expansion. Perioperative infections in immediate two‐stage TE to implant breast reconstructions are significant and occur mostly prior to the start of expansion. Thus, challenging the conventional wisdom that instrumentation during expander filling as the primary cause of implant infections. Possible etiologic factors include greater age, therapeutic mastectomy versus prophylactic mastectomy, larger initial TE fill, and the use of ADM.     

Is there a rational basis for post-surgical lifting restrictions? 1. Current understanding

Lifting restrictions postoperatively are quite common, but there appears to be little scientific basis for them. Lifting restrictions are inhibitory in terms of return to work and may be a factor in chronicity. The mean functional spinal motion unit stiffness changes with in vitro or computer-simulated discectomies, facetectomies and laminectomies were reviewed from the literature. We modified the NIOSH lifting equation to include another multiplier related to stiffness change post surgery. The new recommended lifts were computed for different lifting conditions seen in industry. The reduction of rotational stiffness ranged from 21% to 41% for a discectomy, 1% to 59% for a facetectomy and 4% to 16% for a partial laminectomy. The recommended lifts based on our modified equation were adjusted accordingly. There is no rational basis for current lifting restrictions. The risk to the spine is a function of many other variables as well as weight (i.e., distance of weight from body). The adjusted NIOSH guidelines provide a reasonable way to estimate weight restrictions and accommodations such as lifting aids. Such restrictions should be as liberal as possible so as to facilitate, not prevent, return to work. Patients need more advice regarding lifting activities and clinicians should be more knowledgeable about the working conditions and constraints of a given workplace to effectively match the solution to the patient’s condition. Received: 31 July 1998 Revised: 21 January 1999 Accepted: 11 February 1999     

Assessment of trunk function in single and multi-level spinal stenosis: a prospective clinical trial

OBJECTIVE: To clarify the biomechanical indicators of single- and multi-level stenosis and to determine the biomechanical outcome of selective conservative decompression. DESIGN: This study is a prospective clinical trial examining trunk function in spinal stenosis patients operated using a conservative procedure in an orthopaedic clinic. BACKGROUND: Although several clinical studies have examined the instability and motion characteristics of operated lumbar spinal canal stenosis, few if any studies have prospectively examined the biomechanical outcome of lumbar spinal canal stenosis surgery. METHODS: Comprehensive pre- and post-operative trunk dynamometer strength and motion analysis tests were performed on 36 patients operated for lumbar canal stenosis. Surgical treatment efficacy was evaluated within a three variable crossed factorial design considering stenosis classification, number of operative levels, and changes in several trunk biomechanical outcomes from pre- to post-operative assessment. Patients were evaluated after a minimum one-year follow-up. RESULTS: Pre-operatively there were no differential effects associated with stenosis classification or number of operated levels. There was a significant post-operative increase in isometric trunk extension torque and flexion-extension power and a return to a more normal trunk extension-flexion torque ratio. Patients with mixed, single level stenosis demonstrated greater trunk extension power both pre- and post-operatively compared to other patients. CONCLUSIONS: Conservative surgical treatment of lumbar spinal stenosis produced a marked improvement in the functional mechanical status of the low back. RELEVANCE: This study assists clinicians and researchers to understand trunk function following conservative surgical treatment of lumbar spinal stenosis.