Rhabdomyolysis and spine surgery: A systematic review of the literature.

Rhabdomyolysis is characterized by the rupture of skeletal muscles due to a lot of reasons such as exercise, drug addiction, toxins, infections, trauma and some medications. The etiology of postoperative rhabdomyolysis is potentially multifactorial and has been documented in several types of surgery. The lysis of cell membrane releases organic and inorganic intracellular components that can be toxic and life threatening. Creatinephosphokinase (CPK) is one of the components and it is the most sensitive indicator of myocyte injury. The classic triad of symptoms is characterized by myalgia, weakness and brown-red urine. There is not a clearly agreed level of serum CPK that is evident for diagnosis of rhabdomyolysis. However, a CPK level higher than 5 times of its normal value is accepted by many authors as diagnostic criteria. Acute kidney injury is the most serious complication of rhabdomyolysis in the days following initial presentation and develops in 33% of patients. The objective of this study was to perform a review of the literature, aiming at a better understanding about the changes in CPK levels and the frequency of rhabdomyolysis in spine surgery, with special attention in posterior lumbar fusion. Nineteen studies were selected for analysis. The studies had different characteristics considering patients age, body mass index, comorbidities and type of surgery. The best available evidence points out to the prognosis depend on the extension and clinical severity of rhabdomyolysis, as well as on the early and prompt medical intervention.

Predictive Factors for Muscle Injury After Posterior Lumbar Spinal Surgery.

OBJECTIVE: The aims of this study were to evaluate the risk factors for muscle injury in patients undergoing posterior lumbar spinal surgery and the clearance of postoperative biochemical changes following lumbar fusion and secondarily to evaluate the timing for monitoring postoperative biochemical serum levels and potential clinical correlation. METHODS: The study prospectively enrolled 39 patients with degenerative disease of the lumbar spine. Biochemical markers (creatine phosphokinase [CPK], creatinine, and hemoglobin) were analyzed in 5 predefined stages. All relevant clinical data were collected. Rhabdomyolysis (RML) was defined as a postoperative 5-fold increase of the baseline CPK value. RESULTS: Patients from the lumbar fusion group had the highest postoperative CPK ratio. Overall, the rate of RML was 43.6%. CPK and creatinine activity reached their maximum on the first postoperative day in 69.2% and 87.5% of patients, respectively. Lumbar fusion (P = 0.005), surgical time >270 minutes (P = 0.028), and fall in hemoglobin levels >3 g/dL (P = 0.034) were identified as independent factors associated with higher risk of RML. CONCLUSIONS: The risk of RML increases with prolonged and invasive surgery with higher bleeding potential. Knowing the clearance of postoperative biochemical changes permits a standardized strategy with measurements in precise intervals, thereby avoiding unnecessary costs. The clinical significance is still undetermined.

The course of Modic vertebral body changes after posterolateral lumbar fusion on fused and adjacent levels: A systematic review of the literature.

According to the original description by Modic et al., the natural course of bone marrow signal abnormalities is an inexorable, progressive one, however recent evidence has demonstrated in healthy individuals and those suffering from lumbar disc herniation that the course of endplate degenerative changes is rather dynamic and sometimes regressive. The evolution of such changes in lumbar fused segments and adjacent levels is largely unknown. The literature relevant to the course of Modic changes on fused and adjacent levels, as well as its clinical correspondence in patients undergoing posterolateral lumbar fusion was collected. Two studies met the criteria. Of 38 patients with Modic type I signals preoperatively, 6 regressed to type 0, 22 progressed to type 2, and 10 remained the same postoperatively. Of 12 patients with Modic type 2 signals preoperatively, 2 regressed to type 0 and 10 remained the same postoperatively. None of the articles described the Modic changes in adjacent levels. Clinical and functional outcomes were significantly improved at follow-up regardless of the endplate signal changes. The best available evidence points out to a reduction in Modic type I frequency on fused segments, either regressive or progressive. There was a predominance of new type II changes in postoperative images, which might represent improvement of instability. This study calls into attention the controversial role of Modic changes as an indicator of clinical significance, since clinical and functional outcomes significantly improved regardless of the endplate signal changes.