Discrepancies Between Patient and Surgeon Expectations of Surgery for Sciatica: A Challenge for Informed Decision Making?

STUDY DESIGN: Qualitative study. OBJECTIVE: The objective of this study was to compare the perceptions of patients and surgeons regarding the risks and benefits of lumbar decompressive surgery for sciatica following a consultation meeting. SUMMARY OF BACKGROUND DATA: Evidence regarding pain improvement in patients following lumbar decompressive surgery for sciatica is inconsistent. Given this inconsistency, patients choosing to undergo lumbar decompressive surgery must accept the risks associated with the surgery despite uncertainty regarding benefits. This raises questions as to the nature of informed decision-making for patients choosing to undergo surgery for sciatica. METHODS: We undertook a qualitative descriptive study with 12 adult lumbar decompressive surgery candidates and six of their spine surgeons and analyzed data using inductive content analysis. RESULTS: Our analysis revealed that most patients were satisfied with the consultation despite limited understanding of lumbar decompressive surgery. We found discrepancies between patients' preoperative expectations and understanding of information provided by surgeons and what surgeons believed they had conveyed. Surgeons and patients disagreed on how much information is needed about postsurgical activity modifications and long-term outcomes to make a decision about whether or not to undergo surgery, with patients desiring more information. As a result, for most patients, the decision-making process extended beyond the information provided by surgeons and incorporated information from family members, friends, family doctors, and the internet. CONCLUSION: Our results highlight misunderstandings between patients and surgeons, particularly in regard to prognosis and activity modifications. Since this information is important for patients choosing whether to undergo a surgical intervention, our study provides guidance to improve informed decisions about sciatica and, potentially, other elective surgeries. LEVEL OF EVIDENCE: 4.

Ultrafast laser ablation and machining large-size structures on porcine bone.

When using ultrafast laser ablation in some orthopedic applications where precise cutting/drilling is required with minimal damage to collateral tissue, it is challenging to produce large-sized and deep holes using a tightly focused laser beam. The feasibility of producing deep, millimeter-size structures under different ablation strategies is investigated. X-ray computed microtomography was employed to analyze the morphology of these structures. Our results demonstrated the feasibility of producing holes with sizes required in clinical applications using concentric and helical ablation protocols.

Injury measurement properties of serum interleukin-6 following lumbar decompression surgery.

BACKGROUND: Circulating interleukin-6 (IL-6) is frequently used to study surgical injury and inflammation. Measurement properties of serum IL-6 were examined following lumbar decompression surgery (LDS), including time course, sensitivity, and validity for detecting muscle trauma in comparison to the muscle cytoplasmic protein creatine kinase (CK). MATERIALS AND METHODS: Seven women and seven men had serial blood samples taken in the preoperative waiting areas, immediately after surgery, at 6, 12, 24, 48 h, 4 d, and at 6 to 7 d. Lumbar surgeries were single level, decompression, with laminotomy. RESULTS: Time to peak serum IL-6 varied across individuals (range 6 to 48 h). However, the higher of two samples drawn within the sensitive time window (6 to 24 h) had a strong correlation with peak IL-6 (r = 0.99, P < 0.001). There was a moderate correlation between the rise in serum IL-6 and rise in serum CK, r = 0.56, P < 0.05. T-tests revealed that group mean IL-6 was significantly elevated at only one serial time point (6 h), whereas group mean CK was significantly elevated at three serial time points (6, 12, 24 h) and approached significant elevation as late as 48 h (P = 0.07). Women had lower CK concentrations at 6 and 24 h but gender differences on IL-6 were not statistically significant. CONCLUSIONS: The serum IL-6 response to LDS injury can be captured in a practical manner, despite individual variability in time course. Inclusion of CK measurement may improve sensitivity to the muscle trauma component of an overall injury.

Validity of serum creatine kinase as a measure of muscle injury produced by lumbar surgery.

BACKGROUND AND PURPOSE: Serum creatine kinase (CK) concentrations have historically been used to investigate muscle disease and serious muscle damage, and there is a growing interest in the potential for a biochemical approach to quantifying skeletal muscle injury occurring in orthopedic surgeries and spinal injuries. The wide availability of CK measurement could foster spinal muscle injury research. However, measurement validity has never been systematically demonstrated in clinical settings. In this study, the validity of serum CK concentration elevation as an index of muscle injury was investigated using lumbar decompression surgery (LDS) as a model. SUBJECTS AND METHODS: Blood samples were obtained from 18 research volunteers drawn from the clinical population undergoing LDS. A baseline sample was taken in the preoperative waiting area. Each subject's highest CK concentration between 12 and 48 hours after surgery was used as the biochemical injury response. The surface area of muscle isolated (incision lengthxdepth) and strained by retraction was obtained for concurrent validity testing against biochemical measurement. RESULTS: The correlation between highest total CK concentration and muscle surface area was moderate (r=0.60) and significant (P<0.01). Correlations between surface area and CK at specific time points, revealed minimal loss of association at 12 hours (r=0.57) and 24 hours (r=0.58), but weaker correlations at 6 hours (r=0.45) and 48 hours (r=0.28) after injury. Analyses for proportions of each isoenzyme making up the total CK revealed that baseline and peak CK consisted almost exclusively of skeletal muscle CK (CK-MM), with minimal representation by heart muscle (CK-MB), and brain (CK-BB). CONCLUSIONS: The findings provide support for the validity of serum CK measurement as an index of skeletal muscle injury caused by LDS, and demonstrate that LDS provides a useful model for measurement testing and development studies.

Biochemical measurement of muscle injury created by lumbar surgery.

PURPOSES: 1. To determine whether lumbar disc surgery (LS) provides a sufficiently detectable rise in serum creatine kinase (CK) concentration to serve as a model to study biochemical measurement of muscle injury, and 2. To use the model to examine the consistency of the time course of CK concentration changes. METHOD: The study used a repeated measures design. Six women and six men scheduled for LS were recruited. Blood samples were taken in the pre-operative waiting areas, immediately after surgery, at 6 hour intervals until discharge, and at 2, 4, and 6 to 7 days following surgery. Total serum CK was quantified using the Roche Modular to detect enzyme concentration. RESULTS: Following LS, mean Total CK increased from a baseline 50 U/L (SD = 53) to a peak 114 U/L (SD = 32) in women (P < 0.001) and from 183 U/L (SD = 69) to a peak 454 U/L (SD = 173) in men (P < 0.05). Baseline to peak changes in CK exceeded subjects' own baseline fluctuations in all 6 women and all 6 men, and amounted to a mean 6 fold (SD = 4) increase in women and 16 fold (SD = 31) increase in men. While CK concentrations returned to baseline over the observation period in all subjects, time to peak ranged between 9 to 47 hours. CONCLUSIONS: The LS model produced a consistently detectable CK response in both genders. Time to peak is variable indicating a need for multiple serial measures to capture this biochemical injury response.