The efficacy of ketamine for postoperative pain control in adolescent patients undergoing spinal fusion surgery for idiopathic scoliosis.

The use of ketamine in conjunction with morphine to reduce postoperative pain has been explored in several different surgery subtypes with conflicting results. Ketamine has shown promise to have both opioid sparing and analgesic effects in the postoperative setting. This study aimed to elucidate ketamine's ability to reduce morphine equivalent consumption and improve patient satisfaction after spinal fusion surgery for the correction of idiopathic scoliosis. This surgery is known to be associated with significant postoperative pain which impedes the ability to improve patient satisfaction, and may complicate the recovery timeline. Currently, the standard therapeutic regimen consists of patient-controlled analgesia morphine and the use of other opioids such as hydromorphone. A prospective, randomized double-blinded, placebo-controlled trial was performed to compare the standard morphine equivalent therapy alone against a standard therapy in conjunction with ketamine. Fifty adolescent patients were enrolled and randomized. Results yielded a significant reduction in postoperative morphine equivalent consumption (p = 0.042), adjusted postoperative pain scores (p < 0.001), and incidence of nausea and vomiting (p = 0.045). The application of ketamine as an analgesic in conjunction with the current standard of morphine equivalent therapy may serve as a superior pain control regimen for spinal surgeries in young population. This regimen enhancement may be generalizable to other surgery subtypes within similar populations. LEVEL OF EVIDENCE: Level I.

Histological Evidence of Muscle Degeneration in Advanced Human Rotator Cuff Disease.

BACKGROUND: Cellular remodeling in rotator cuff muscles following a massive rotator cuff tear is poorly understood. The aim of the current study was to provide histological evidence to elucidate the mode of muscle loss in advanced human rotator cuff disease and to assess tissue-level changes in relation to findings on noninvasive imaging. METHODS: Rotator cuff muscle biopsy samples were taken from the scapular fossae from 23 consecutive patients undergoing reverse total shoulder arthroplasty in order to evaluate muscle composition in severe rotator cuff disease. Markers of vascularity; inflammation; fat distribution; and muscle atrophy, degeneration, and regeneration were quantified. RESULTS: The samples primarily consisted of dense, organized connective tissue (48.2% ± 19.1%) and disorganized, loose connective tissue (36.9% ± 15.9%), with substantially smaller fractions of muscle (10.4% ± 22.0%) and fat (6.5% ± 11.6%). Only 25.8% of the biopsy pool contained any muscle fibers at all. Increased inflammatory cell counts (111.3 ± 81.5 macrophages/mm) and increased vascularization (66.6 ± 38.0 vessels/mm) were observed across biopsies. Muscle fiber degeneration was observed in 90.0% ± 15.6% of observable muscle fascicles, and the percentage of centrally nucleated muscle fibers was pathologically elevated (11.3% ± 6.3%). Fat accumulation was noted in both perifascicular (60.7% ± 41.4%) and intrafascicular (42.2% ± 33.6%) spaces, with evidence that lipid may replace contractile elements without altering muscle organization. CONCLUSIONS: Dramatic degeneration and inflammation of the rotator cuff muscles are characteristics of the most chronic and severe rotator cuff disease states, suggesting that muscle loss is more complicated than, and distinct from, the simple atrophy found in less severe cases. CLINICAL RELEVANCE: In order to address degenerative muscle loss, alternative therapeutic approaches directed at muscle regeneration must be considered if muscle function is to be restored in late-stage rotator cuff disease.