Polycaprolactone/Polylactic Acid Membrane Fails to Prevent Laminectomy-induced Sprouting of CGRP- and SP-immunopositive Nerve Fibres in the Dura mater lumbalis of Rats. / Polycaprolacton/Polylactid-Membran kann Laminektomie-induziertes Wachstum von CGRP- und SP-immunpositiven Nervenfasern in der Dura mater lumbalis von Ratten nicht verhindern.

BACKGROUND CONTEXT: Mechanisms and prevention of failed back surgery syndromes are rarely known in the clinical context. It has been shown that laminectomy induces outgrowth of putative nociceptive peptidergic afferents in the dura mater lumbalis of rats. PURPOSE: We aimed to investigate whether the application of a polycaprolactone/polylactic acid membrane (Mesofol) after surgery inhibits sensory hyperinnervation. MATERIALS/METHODS: Adult Lewis rats were assigned to three groups: Control (no manipulation), Laminectomy and Laminectomy + Mesofol. Six weeks post-surgery, the durae were removed, immunohistochemically stained for CGRP- and SP-positive afferents and their density quantified. RESULTS: In controls, CGRP- and SP-positive neurons were predominantly found in ventral but rarely observed in dorsal parts of the dura. Following laminectomy, the density of afferents significantly increased ventrally, resulting in a dense network of nerve fibers. In dorsal regions, neuronal sprouting of was observed. Covering the dura with Mesofol after laminectomy had no impact on nerve fibre outgrowth. CONCLUSION: Application of Mesofol neither prevents nor significantly diminishes the laminectomy-induced increase in the density of peptidergic afferents.

Magnetically Controlled Growing Rods in Treatment of Early-Onset Scoliosis: A Single Center Study With a Minimum of 2-Year-Follow up and Preliminary Results After Converting Surgery.

STUDY DESIGN: Case series. OBJECTIVE: To evaluate complications and radiographic parameters after magnetically controlled growing rod (MCGR) index surgery (IS), during lengthening and following converting surgery (CS) with a minimum of 2-year follow up (FU). SUMMARY OF BACKGROUND DATA: MCGR are maintaining skeletal growth in treatment of early onset scoliosis (EOS). There is no data regarding correction potential after CS available. METHODS: Twenty-four cases were included. Two patients with rib and pelvic hook fixation instead of pedicle screws and three patients with previous spinal surgery were excluded from radiographic analysis. RESULTS: Twenty-one patients received grade 3 or 4 in Classification of Early-Onset-Scoliosis (C-EOS) for main curve severity. The kyphotic modifiers (-) were given to seven and (+) to seven patients. Mean age at IS was 10.5 ±â€Š2.4 years with a mean FU time of 42.3 ±â€Š11.3 months. Deformity correction was only achieved during IS (46%) and CS (36%). During MCGR treatment a 5° loss of correction seen, while 25 mm of T1-S1 length was gained during the lengthening period. An overall average lengthening of 1.6 mm per lengthening procedure was achieved. Possibility to gain length during distractions decreases over time. No major failure of the distraction mechanism was observed, only 16 lengthening procedures failed within a total of 264 lengthening procedures. A total of 19 revision surgeries in 10 patients were observed. Four patients received more than one revision surgery. CONCLUSION: Applying MCGR results in a revision rate of 0.23 per patient and per one FU year, while making further lengthening procedures obsolete compared with conventional growing rod techniques. Correction of major curve is possible during IS und CS. The law of diminishing returns applies during the period of lengthening. LEVEL OF EVIDENCE: 4.

Rasterstereography versus radiography for assessing shoulder balance in idiopathic scoliosis: A validation study relative to patients' self-image.

BACKGROUND: Shoulder imbalance is a problem for scoliosis patients. Rasterstereography uses radiation-free surface topography to follow up these patients. Its use for assessing shoulder level has not been investigated earlier. OBJECTIVE: This study aimed to determine the accuracy of shoulder assessment using rasterstereography (versus radiography) and to analyze its relationship with patients' self-image. METHODS: In a cross-sectional setting, the reliability and validity of five rasterstereographic shoulder variables were measured in comparison with six radiographic shoulder parameters, using correlation analysis. The patients' self-perception was documented using the Scoliosis Research Society-22 (SRS-22) questionnaire and Trunk Appearance Perception Scale (TAPS). RESULTS: Forty patients were included in the study. The test-retest reliability of all rasterstereographic shoulder parameters was excellent (ICC > 0.95). The validity was moderate in comparison with six radiographic parameters (highest coefficient: 0.582). The radiographic and rasterstereographic shoulder levels correlated with the results in the SRS-22 questionnaire (highest coefficient: -0.463) and TAPS (highest coefficient: 0.413). CONCLUSIONS: Rasterstereography is a reliable and valid method for assessing shoulder level in idiopathic scoliosis. The parameters can be recommended as a complement to radiography and clinical evaluation for follow-up purposes. Radiographic and rasterstereographic shoulder parameters are significantly related to patients' self-perception. Shoulder variables thus need to be considered in scoliosis patients.

Predictors of shoulder level after spinal fusion in adolescent idiopathic scoliosis.

BACKGROUND: For patients with adolescent idiopathic scoliosis, shoulder balance influences their treatment satisfaction and psychological well-being. Several parameters are known to affect postoperative shoulder balance, but few prognostic models are as yet available. PURPOSE: This study aimed to identify independent predictive factors that can be used to assess preoperatively which patients are at risk of postoperative shoulder elevation, and to build a linear prediction model. METHODS: N = 102 patients with all Lenke types were reviewed radiographically before surgery and 1 year afterward. The outcome measures were coracoid height difference (CHD), clavicular angle (CA), and clavicle-first rib intersection difference (CiRID). Predictive factors commonly used in the literature were investigated using correlation analysis and statistical testing. Significant contributing factors were included in three multiple linear regression models (for CHD, CA, and CiRID). RESULTS: The mean shoulder level (CHD) significantly changed from a lower left shoulder value of -8.5 mm before surgery to 3.3 mm at the follow-up examination. A high preoperative left shoulder level by CiRID, a large amount of Cobb angle correction of the distal thoracic curve, a low preoperative Cobb angle in the lumbar curve, and a structural proximal thoracic curve proved to be determinants and thus risk factors for left-sided shoulder elevation after surgery. The three models predicting CHD, CA, and CiRID at the follow-up examination included these four risk factors and were significant. CONCLUSIONS: Preoperative variables have the strongest influence on shoulder level after spinal instrumentation. Additionally, extensive correction of the distal thoracic curve can cause elevation of the left shoulder.