[Diagnostics and treatment of hourglass-like nerve constrictions and torsions in neuralgic amyotrophy]. / Diagnostik und Therapie sanduhrförmiger Nervenstrikturen und -torsionen bei neuralgischer Amyotrophie.

Neuralgic amyotrophy is a disease of the peripheral nervous system characterized by severe neuropathic pain followed by peripheral paralysis. A distinction is made between a hereditary and an idiopathic form, which is assumed to have an autoimmunological origin. Conservative medicinal treatment mainly consists of nonsteroidal anti-inflammatory drugs (NSAID), opioids and glucocorticoids; however, despite treatment, symptoms in the form of pain or paralysis persist in over 50% of cases. Inflammation can lead to strictures and torsions of peripheral nerves, which can be visualized by imaging using nerve sonography or magnetic resonance (MR) neurography and confirmed intraoperatively during surgical exploration. Based on the currently available data, patients with strictures and torsions of peripheral nerves can benefit from neurosurgical treatment.

Vertebral column growth in children with early onset scoliosis treated with magnetically controlled growing rods - Effects of distraction on vertebral and disc morphology.

OBJECTIVES: To report changes in vertebral and disc morphology following treatment of early onset scoliosis (EOS) with magnetically controlled growing rods (MCGR). METHODS: 30 Patients, 21 girls and 9 boys, treated with MCGR for EOS were compared to a matched control group of 19 patients (12 girls, 7 boys) treated with bracing or observation. Age at surgery in the MCGR group was 8.75 (range: 4.6-11) years compared to 7.75 (range: 3.5-10.3) years in the control group at the time of onset of treatment. Mean follow-up was 45 (range: 24-65) months in the MCGR group vs 42 (range: 24-65) months in the control group. Calibrated radiographs were used to digitally measure disc height, vertebral body height, depth and width after surgery and at latest follow-up. Height, width and depth of lumbar and thoracic vertebrae and discs under distraction were compared to the control group and to vertebrae below instrumentation. T1-T12, T1-S1 length and Cobb angles were also measured. RESULTS: (1) There is a significant increase of lumbar vertebral height under distraction. (2) Lumbar disc height as well as lumbar vertebral width within distraction is significantly reduced. (3) Depth of lumbar vertebrae is not significantly affected by distraction. (4) Morphology of thoracic vertebrae and adjacent discs is not significantly changed with distraction. (5) T1-T12 distance did not show any significant changes between surgical and control group, while T1-S1 growth was significantly reduced compared to the control group. CONCLUSIONS: Significant changes of morphology of lumbar vertebra and discs are observed under distraction with MCGR compared to segments below instrumentation and the control group. LEVEL OF EVIDENCE: Level III - retrospective comparative series.

Postnatal Repair of Open Neural Tube Defects: A Single Center with 90-Month Interdisciplinary Follow-Up.

After publication of the Management of Myelomeningocele Study (MOMS) there is confusion regarding which treatment of open neural tube defects (NTD) is best. We report our results of postnatally repaired open NTDs born between 2007-2018 (n = 36) in critical reflection of the MOMS study. Neurosurgical, orthopedic, and urologic data were assessed. We also introduce a new entity: "status post prenatal repair". FU ranged from 29 to 161 months (mean: 89.1 m) in 7 cases of myeloschisis and 24 myelomeningoceles in the final collective n = 31. The shunt rate was 41.9%, and the endoscopic third ventriculostomy rate was 16.1%. Hydrocephalus requiring treatment was not associated with the anatomical level, but with premature birth (p = 0.048). Myeloschisis was associated with shunt placement (p = 0.008). ROC analysis revealed birth <38.5th week predicts the necessity for hydrocephalus treatment (sensitivity: 89%; specificity: 77%; AUC= 0.71; p = 0.055). Eight (25.8%), patients are wheelchair-bound, 2 (6.5%) ambulate with a posterior walker, 10 (32.3%) with orthosis and 11 (35.5%) independently. One (3.2%) patient underwent detethering at 5.5 years. A total of three patients underwent five Chiari decompressions (9.6%). Further, nineteen orthopedic procedures were performed in nine patients (29.0%). A total of 17 (54.8%) patients self-catheterize, which was associated with an anatomical lesion at L3 or below (p = 0.032) and 23 (74.2%) take anticholinergic medication. In conclusion, shunt dependency is associated with myeloschisis, not with the anatomical defect level. Hydrocephalus treatment is associated with premature birth. In this postnatal cohort with significantly longer follow-up data than the MOMs study, the ambulation rate is better, the shunt rate lower and the secondary tethered cord rate better compared to the MOMS study.

[Combined distal nerve and tendon transfer in drop wrist for treatment of high injuries of the radial nerve]. / Kombinierter distaler Nerven- und Sehnentransfer bei Fallhand zur Behandlung hoher Verletzungen des N. radialis.

OBJECTIVE: The aim of direct distal selective nerve transfer close to the end organ with high radial nerve injury is restoration of the paretic function before irreversible atrophy of the target muscle. Simultaneous tendon transfer enables direct functional correction of wrist drop. INDICATIONS: Selective nerve and tendon transfer of the lower arm is indicated if a) the primary nerve lesion is located proximally distant and reinnervation by direct nerve repair would take too long to reach a paretic muscle because of the long distance involved, b) direct repair of the nerve lesion is impossible or c) there has been a substantial delay after the primary injury. A viable donor nerve must be available. CONTRAINDICATIONS: A) After final denervation of a muscle, which occurs approximately 1.5 years after a nerve injury, the atrophy is irreversible and a nerve transfer can no longer restore the paretic muscle. Only younger patients under 30 years old might benefit from delayed nerve transfer. B) When no sufficient donor nerve is available only tendon transfer is possible. SURGICAL TECHNIQUE: Direct nerve transfer from the median nerve to the radial nerve as well as direct functional correction of wrist drop by tendon transfer of the pronator teres muscle. POSTOPERATIVE MANAGEMENT: Immobilization of the arm for 3 days, wrist orthosis for 6 weeks for protection of the tendon transfer, ergotherapy and physiotherapy preferably by a hand therapist. RESULTS: Active wrist and finger extension 2 years after transfer, with individualized extension of the thumb and index finger is possible, wrist drop reversed.

Posterior fusion of the craniocervical junction in the pediatric spine: Wright's translaminar C2 screw technique provides for more safety and effectiveness.

PURPOSE: Posterior fusion of the craniocervical junction (CCJ) has always been challenging in children with rare congenital diseases and malformations. At our institution, the introduction of the translaminar C2 screw technique led to a significant improvement in the quality of treatment. METHODS: Retrospective analysis of a pediatric cohort at a single institution who underwent CCJ posterior fusion between 2007 and 2018. Patients were divided into group 1 (other posterior fusion techniques, n = 12) and group 2 (translaminar axis screw placement, n = 19). Diagnosis, sex, age at surgery, surgical technique, immobilization, revisions, fusion, reduction, and complications were assessed. RESULTS: Follow-up ranged from 12 to 145 months (mean 50.7). The initial fusion rate detected at 3 months by CT differed significantly (66, 7% in group 1 vs. 100% in group 2, p = 0.018). Full reduction of C1/C2 malalignments was achieved in 41, 6% of group 1 versus 84, 2% of group 2 (p = 0.007). Immobilization was applied in 83, 3% of group 1 versus 26, 3% of group 2 (p = 0.0032). Ten complications were treated conservatively, and 15 events required revision surgery (80% in group 1 vs. 20% in group 2). Eight complications were related to immobilization. CONCLUSIONS: The implementation of the translaminar C2 technique resulted in significantly more safety and efficiency regarding pediatric posterior fusion CCJ surgery at our institution, with significantly higher rates of rigid fixation, full reduction, and fusion, and significantly lower rates of complications and immobilization. These slides can be retrieved under Electronic Supplementary Material.

Pedicle screw instrumentation with or without pelvic fixation in neuromuscular scoliosis: Outcome and complications in a series of 37 patients with a minimum 2-year follow-up.

OBJECTIVE: Neuromuscular scoliosis (NMS) is often associated with rapid progressive spinal deformities. Indications, when to extend the instrumentation to the pelvis for pelvic obliquity are not generally accepted at this time. This study reports on the indications, surgical technique and results using pedicle screw instrumentation exclusively with or without pelvic fixation for spine fusion in patients with NMS. PATIENTS AND METHODS: Thirty-seven NMS patients were treated with pedicle screw instrumentation (PSI) between 2007 and 2013 with a minimum follow-up of 24 months. The mean age at the time of operation was 14.91 ± 2.03 years (range, 11.17-18.58). Posterior spine fusion (PSF) was conducted in 33 patients; 4 patients underwent a combined anterior spinal release followed by PSF during one-stage surgery. Pelvic fixation was achieved by ilium screws combined with S-1 screws in 4 cases and by sacral-alar-iliac (SAI) technique by Sponseller in 9 cases, respectively. RESULTS: The mean primary Cobb angle was 65.5° (range, 14-103°) and improved significantly to 19.8° (range, 1-50°, p < 0.001) after surgery and 20.5° (range, 3-57, p = 0.47) at 2 years FU, respectively. Besides, an improvement of pelvic obliquity and T1 tilt angle could be detected. Major complications occurred in 19% and minor complications in 32%. CONCLUSION: Pedicle screw fixation only for spine fusion in patients with NMS can be applied safely with reasonable complication rates. An excellent correction in all planes, a significant improvement of the pelvic obliquity and almost no loss of correction at 2 years FU were observed.

Intrathecal baclofen therapy for treatment of spasticity in infants and small children under 6 years of age.

PURPOSE: The aim of this study is to prove the efficacy and safety of intrathecal baclofen therapy in infants and children below 6 years of age by retrospective analysis of our pediatric cohort of 135 primary pump implantations. METHODS: Between 2007 and 2018, 17 patients with pump implantations were below 6 years of age. Data were acquired retrospectively with a follow-up of 12 months to 11 years regarding complications. RESULTS: The youngest infant was 11 months at implantation with a bodyweight of 6, 4 kg, and 63 cm length. Surgical complications were comparable to published literature and mainly involved the catheter (2 catheter dislocations and 1 catheter transection) and one pump infection resulting in 4 revision surgeries in 3 patients. One baclofen-related apnea during titration and an overdose after refill were treated conservatively. Using a subfascial implantation technique, we observed neither skin ulceration nor pump infection since 2007. In a growing child, catheter slides are common and related to growth, scoliosis, spine surgery, and surgical failure. CONCLUSION: Intrathecal baclofen therapy in infants and small children is as safe and effective as published for older pediatric patients; therefore, intrathecal baclofen can be considered in all infants as long as an 8-cm incision fits into the triangle of the anterior superior iliac spine, costal margin of the 10th rib, and navel. We suggest the utilization of subfascial surgical technique for implantation pump and catheter. Titration of intrathecal baclofen should be performed slowly to avoid bradycardia in infants. This is a retrospective study (level of evidence 4).

Nerve transfer from the median to musculocutaneous nerve to induce active elbow flexion in selected cases of arthrogryposis multiplex congenita.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is a rare disease which affects mainly upper and lower extremities. Affected patients are not able to eat unassisted due to elbow contracture and nonexistent active elbow flexion. In traumatic brachial plexus palsies, a nerve transfer from either median or ulnar nerve to the musculocutaneous nerve has proved to induce active elbow flexion, and we report our results of such a procedure in a nontraumatic condition, that is, arthrogryposis. METHODS: We selected four patients with AMC type 1 (6 extremities, 2 males, 2 females) diagnosed with AMC presenting to our institution shortly after birth from 2014 to 2016 to perform a nerve transfer from the median nerve to the musculocutaneous nerve in order to induce active elbow flexion. The indication of application of this surgical procedure was based on active finger and wrist flexion, limited contracture of elbow joints and evidence of flexing muscle fibers detected by sonography. RESULTS: Five nerve transfers were conducted with a follow up of 2-5 years. Two extremities reached active elbow flexion motorgrade M4, two M3, and one M1 at latest follow up. One patient developed a postoperative suture granuloma. One nerve transfer was abandoned due to neuroanatomic variation. One extremity was treated with botulinum toxin in triceps muscle in addition to the nerve transfer. CONCLUSIONS: In this series of selected cases of AMC Type 1 we were able to induce active elbow flexion using a nerve transfer technique developed for traumatic and obstetric brachial plexus palsies. In four extremities the procedure achieved independent hand-to-mouth active elbow flexion. Level of evidence four.

Treatment of pediatric spinal deformity with use of recombinant human bone morphogenetic protein-2.

In pediatric spine surgery nonunion is a challenging issue. Instability may cause neurological impairment and lead to numerous surgeries in order to achieve fusion. The use of rhBMP-2 for pediatric spinal fusion has not been widely reported. In this study, a series of 13 children (14 procedures) that underwent spinal rhBMP-2 application were analyzed in order to measure clinical and radiographic outcome. Therefore, patient data, diagnosis, construct of instrumentation, type of bone graft, quantity of BMP used, and fusion outcome were reviewed. The study cohort included four female and nine male patients with a mean age of 11.2 years (range 2.6-19.2 years) at the time of rhBMP-2 application. Rh-BMP-2 was used in both primary (n = 6) and revision surgery (n = 8) in patients with a high risk for the development of nonunion. The mean follow-up was 51 months (range 12-108 months). Fusion occurred in 11 patients. Complications that may be due to application of rhBMP-2 were seen after four operations. Three patients had an increased body temperature and in one case prolonged wound secretion was evident, treated by local wound care or observation. In one of these patients an extensive postoperative hematoma occurred, necessitating surgical treatment. In conclusion, we could detect high fusion rates following the use of rhBMP-2 in pediatric spine surgery without an increased complication rate attributable to its application. Therefore we consider recombinant human BMP-2 to be an option in selected pediatric spinal procedures, especially in cases with compromised bone healing due to congenital, systemic, or local conditions.

Preliminary Results of Magnetically Controlled Growing Rods for Early Onset Scoliosis.

BACKGROUND: Growth-sparing techniques for the treatment of early onset scoliosis (EOS) have developed significantly over the last years. Traditional growing rods (GRs) require repeated surgical lengthening under anesthesia. Since June 2011 we have been using the magnetically controlled growing rods (MCGR) to treat patients with progressive EOS. METHODS: Thirty-five patients with EOS of different etiologies underwent treatment with MCGR. We record about our preliminary results of 24 patients who fulfilled the inclusion criteria of a minimum follow-up (FU) of 12 month and >3 lengthenings. The mean age at surgery was 8.9±2.5 years. Correction of the primary curve after the index surgery and after lengthenings was measured on standing radiographs using the Cobb technique. T1-T12 and T1-S1 spinal length were also measured. Intraoperative and postoperative complications were recorded. RESULTS: The mean FU was 21.1±7.3 months. All patients had a minimum of 3 outpatient lengthenings [mean, 4.6±1.5 (range, 3 to 8)]. The mean primary curve was 63±15 degrees (range, 40 to 96 degrees) and improved to 29±11 degrees (range, 11 to 53 degrees; P<0.001) after MCGR. The mean major curve after most recent lengthening was 26 degrees (range, 8 to 60 degrees; P<0.07). The T1-T12 as well as the T1-S1 length increased significantly (P<0.001). The mean preoperative thoracic kyphosis decreased from 43±24 degrees (range, -32 to 86 degrees) to 27±12 degrees (range, 9 to 50 degrees; P<0.001) after surgery, respectively, and measured 32±12 degrees (range, 12 to 64 degrees; P<0.05) at last FU. In 1 patient a loss of distraction occurred making rod exchange necessary. Three patients developed a proximal junctional kyphosis and in another patient a screw pull out occurred that required revision surgery. CONCLUSIONS: Our results demonstrate that MCGR is a safe and effective nonfusion technique in the treatment of progressive EOS avoiding repeated surgical lengthening procedures. It provides adequate distraction similar to standard GR. The magnetically induced transcutaneous lengthening allows noninvasive distraction achieving spinal growth comparable to conventional GR techniques. LEVEL OF EVIDENCE: Level IV-retrospective nonrandomized objective study.

Ultrastable laser with average fractional frequency drift rate below 5 × 10⁻¹9/s.

Cryogenic single-crystal optical cavities have the potential to provide high dimensional stability. We have investigated the long-term performance of an ultrastable laser system that is stabilized to a single-crystal silicon cavity operated at 124 K. Utilizing a frequency comb, the laser is compared to a hydrogen maser that is referenced to a primary caesium fountain standard and to the 87Sr optical lattice clock at Physikalisch-Technische Bundesanstalt (PTB). With fractional frequency instabilities of σ(y)(τ)≤2×10(-16) for averaging times of τ=60 s to 1000 s and σ(y)(1 d)≤2×10(-15) the stability of this laser, without any aid from an atomic reference, surpasses the best known microwave standards for short averaging times and is competitive with the best known hydrogen masers for longer times of 1 day. The comparison of modeled thermal response of the cavity with measured data indicates an average fractional frequency drift below 5×10(-19)/s, which we do not expect to be a fundamental limit.

Monolithic all-glass pump combiner scheme for high-power fiber laser systems.

We report on an integrated all-glass pump combiner for ytterbium-doped high power fiber lasers. The combining of multiple pump fibers with an active double clad fiber for high power amplification was successfully achieved by splicing them to a dichromatically coated planar convex lens. The measured coupling efficiency of such a combining scheme was typically in excess of 80%, with 86.5% achieved in maximum. Theoretical analysis is discussed in order to get optimized parameters and to consider the scaling of this type of coupler to higher average powers.