First-in-man application of a cold ablation robot guided laser osteotome in midface osteotomies.

The aim of the study was to assess the clinical applicability of robot guided laser osteotomy for clinical application. This is the initial report on 14 consecutive patients requiring an orthognathic procedure with a midface osteotomy (no restrictions made on the surgical indication itself) who have undergone surgery by means of the Cold Ablation Laser Osteotome CARLO® (AOT Advanced Osteotomy Tools, Basle, Switzerland), which is an integrated system, functionally comprising: an Er:YAG laser source, intended to perform osteotomies using cold laser ablation, a robot arm that controls the position of the laser source, an optical tracking device that provides a continuous and accurate measurement of the position of the laser source and of reference elements attached to instruments or bones, a navigation system (software) that is able to read preoperatively defined planned osteotomies, and - under the control of a surgeon - performs the planned osteotomies. Safety was assessed by unimpaired postoperative healing and the absence of device related injuries; performance was assessed as ability to cut the maxilla along the preoperatively planned cutting path with a rage of accuracy of 2mm. Cold ablation robot-guided laser osteotomy could successfully be performed in 14 consecutive patients. No intraoperative complications or technical failure occurred. All osteotomies were within an average deviation of 0.80 mm (±0.26 mm) of the virtually preplanned location. The registration procedure to set up the robot at the beginning of the operation required a mean time of 4.6 min (±5.3min). In this report we describe the effective and successful routine use of Cold ablation robot-guided laser osteotomy in an actual clinical setting. It is a promising technical innovation that has the potential to set new standards for accuracy and safety in orthognathic surgery.

Spinal epidural abscess: aetiology, predisponent factors and clinical outcomes in a 4-year prospective study.

Spinal epidural abscess (SEA) is a rare, but serious, condition with multiple causes. We prospectively studied the aetiology, predisposing factors, and clinical outcomes of SEA in all patients with SEA treated in our hospital's neurosurgical service from 2004 to 2008. For each patient, we recorded the medical history, comorbidities, focus of infection, pathogen(s), and outcome. The 36 patients (19 women and 17 men) ranged in age from 34 to 80 years old (mean 57; median 56). The SEA was primary (i.e., due to haematogenous spread) in 16 patients (44%); it was secondary to elective spinal procedures, either injections or surgery, in 20 patients (56%). The duration of follow-up was 12-60 months (mean 36; median 37.5). The most common pathogen, Staphylococcus aureus, was found in 18 patients (50%). Patients with primary SEA had different underlying diseases and a wider range of pathogens than those with secondary SEA. Only five patients (14%) had no major comorbidity; 16 of the 20 patients with secondary SEA (44% of the overall group) had undergone spinal surgery before developing the SEA; the treatment of the SEA involved multiple surgical operations in all 16 of these patients, and spinal instrumentation in 5 (14%); 22 patients (61% of the overall group) recovered fully.

Influence of copolymer composition of polylactide implants on cranial bone regeneration.

Biodegradable polymers have become useful auxiliary materials for the functional and structural restoration of bone deficiencies. Commercial implants from poly(L/DL-lactide) 70:30 are used clinically for fracture fixation in regions of low load. Implants manufactured from poly(L/DL-lactide) 80:20 are currently being investigated experimentally. The higher degree of crystallinity results in a higher chemical strength and loading capacity which promises advantages for long-term implantation. In this study implants from these two copolymers were applied to promote bone regeneration of bilateral, full thickness, circular cranial defects in 16 adult New Zealand white rabbits. The defects were covered with melt extruded and laser cut polylactide burr hole covers epicranially and endocranially in direct contact to the dura. The defect spaces were kept open with a spacer which created a hollow chamber. Both materials were implanted in each animal. Bone seeking fluorochromes were used to assess the pattern of bone growth. After eight weeks bone regeneration in the defects was assessed radiologically, histologically and by fluorescence microscopy. During the eight weeks observation period the application of a hollow chamber design resulted in almost complete cranial defect healing, whereby the copolymer composition had no effect on the amount or the morphology of the regenerate. The dura mater showed no adverse tissue reactions during these early stages of implantation. Eight weeks is only a short period in the lifetime of the tested polymers and complete bone regeneration can only be expected after complete polymer degradation. Long-term studies or accelerated degradation studies are required to confirm the expected advantages of poly(L/DL-lactide) 80:20.

A dimeric iridoid from loasa acerifolia.

Reinvestigation of leaf material from Loasa acerifolia DOMBEY led to the isolation of secoxyloganin and an additional novel dimeric iridoid glucoside named asaolaside. The latter consists of a secoxyloganin moiety esterified to the 7-hydroxy group of sylvestroside IV. The structure of asaolaside was established by 1D and 2D NMR ((1)H (1)H COSY, HMQC, HMBC) and FABMS experiments.