ABSTRACT
We present a 10-Gb/s L-band reflective electro-absorption modulator integrated with a semiconductor optical amplifier (REAM-SOA) having improved transmission performance at very low input power of seed light. To decrease the input power of seed light, the absorption characteristics of the REAM are adjusted to reduce the amplified spontaneous emission light returned into the SOA, suppressing the gain saturation effect of the SOA. At a considerably low input power of -16 dBm, the REAM-SOA exhibits a low transmission penalty of about 1.2 dB after 50-km SMF transmission. Over a wide input power range from -16 dBm to 5 dBm, a penalty of less than 1.6 dB is achieved at 50-km transmission.
ABSTRACT
STUDY DESIGN: Retrospective study. OBJECTIVE: To evaluate the effect and outcome of thoracoplasty in conjunction with pedicle screw instrumentation in the treatment of thoracic adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Some spine surgeons recently think more correction of hump deformity using pedicle screws without thoracoplasty. Although thoracoplasty has been conventional treatment of rib hump, there are few papers about the results of pedicle screw instrumentation and concomitant thoracoplasty. METHODS: Eighty-seven patients with thoracic AIS (mean age, 14.4 years) treated by pedicle screw instrumentation were retrospectively analyzed after a minimum follow-up of 2 years. Patients were divided into 3 groups; N-T group (no thoracoplasty with iliac bone graft, n = 37), T+N-DVR [thoracoplasty without direct vertebral rotation (DVR), n = 20] and T+DVR group (thoracoplasty with DVR, n = 30). In the T (T+N-DVR and T+DVR) group, 4 to 8 ribs were resected and used for bone graft. Patients were evaluated for deformity correction, balance, pulmonary function, height and angle of rib hump, clinical outcomes (SRS-30), and complications. RESULTS: In the N-T group, the thoracic curve was corrected from 53 degrees to 16 degrees (69% correction), in the T+N-DVR group from 55 degrees to 18 degrees (69%) and in the T+DVR group from 54 degrees to 10 degrees (81%). There was no difference in postoperative spinal balance and pulmonary function among the 3 groups. The correction rates of hump height and angle were 35% and 38% in the N-T group, respectively, 57% and 58% in the T+N-DVR, and 70% and 72% in the T+DVR. The T group showed significantly better correction of rib hump and self-image score in the SRS-30 questionnaire than the N-T group. There were 8 iliac donor site problems in the N-T group and 3 hemothorax in the T group, which had no adverse effect in the final result. CONCLUSION: Thoracoplasty showed significantly better rib hump correction, satisfactory clinical outcomes without pulmonary function compromise, or iliac bone graft site morbidity in the treatment of thoracic AIS with pedicle screw instrumentation.