Spinal Instrumentation

Spinal instrumentation basically means the implantation of more or less rigid metallic or non-metallic devices which are attached to the spine. These devices function to provide spinal stability and thus facilitate bone healing leading to spinal fusion (spondylodesis). Fundamental biomechanical knowledge and its application serves to improve the performance of the individual spine surgeon with respect to the rate of bony fusion, implant failure or degree of deformity correction. However, biomechanics is inherently linked with (mechano-)biology. And there is still an incomplete understanding of spinal biomechanics and even more so of the underlying biology. Moreover, apparently advantageous biomechanical concepts do not necessarily lead to a better patient outcome.

Growth of lung allografts after experimental transplantation

Heart and lung transplantation has been performed in cases of end-stage cardiopulmonary disease in infants. Nevertheless, it still remains unclear whether lung allografts adjust to a growing organism. In 6 young domestic pigs unilateral left lung allotransplantation was performed. Immunosuppression consisted of a triple drug therapy including cyclosporine, azathioprine, and corticosteroids. Lung growth was studied by using bronchography, pulmonary angiography, and lung histology. After 11 weeks the transplanted animals had doubled their body weight from 24 kg to 48 kg. Non-transplanted animals in contrast doubled their weight within only 6 weeks. The growth retardation was attributed to the immunosuppressive therapy. The bronchial tree and pulmonary vasculature of lung allografts showed a similar growth potential to non-transplanted lungs in animals of equivalent body weight. In one case of recurrent severe rejection of the lung no growth was observed. Therefore it was concluded that lung allografts grow adequately according to the development of the recipient organism. Lung transplantation in children does not seem to be restricted by a limited growth potential of the graft.

Outcome of transmetatarsal amputations in diabetics using antibiotic beads

BACKGROUND: Diabetic patients with transmetatarsal amputation (TMA) for chronic forefoot ulceration or necrosis are at high risk for postoperative skin breakdown and subsequent amputation. Locally applied antibiotics may reduce the revision rate and improve the outcome. MATERIAL AND METHODS: In a retrospective comparative study, 60 diabetic patients (65 feet) with forefoot ulceration or necrosis were treated with TMA by three surgeons in three hospitals. In the "beads group'' (46 patients, 49 feet) TMA was combined with local application of bioabsorbable, tobramycin impregnated calcium sulphate beads (OsteoSet-T beads, Wright Medical, Memphis, TN) as a single-stage procedure. The remaining 16 patients had transmetatarsal amputation without beads at the surgeon's discretion and acted as a control group. For all patients, time to healing, length of hospital stay, number of revisions for wound breakdown and conversions to a higher-level amputation were retrospectively reviewed. Of the 60 patients 17 had died and three were lost to followup, leaving 40 patients available for latest followup at 29 months. The Foot ; Ankle Outcome Score, Foot Function index, SF-36, and Comorbidity score were recorded. RESULTS: The revision rate for wound breakdown after TMA was 8.2% (4/49) in the beads group, and 25% (4/16) in the control group (p<0.05). At latest followup, 27% (13/49) in the beads group, and 25% (4/16) in the control group had to be converted to transtibial amputation. Patients in the beads group scored worse for activities of daily living in the FAOS and SF-36 (p < 0.05), and demonstrated more health problems in the Comorbidity scores (not significant), indicating sicker individuals in the beads group. CONCLUSION: Bioabsorbable calcium sulphate antibiotic beads may be a useful addition for TMA for patients with non-healing diabetic ulcerations of the forefoot. The single-stage procedure could have a significant impact on the management of diabetic forefoot ulcerations by preventing additional hospital stays, improving the patient's quality of life and minimizing cost.

Osteosynthesis and hemiarthroplasty of fractures of the proximal humerus: outcomes in a consecutive case series

HYPOTHESIS: This study addresses the outcome after osteosynthesis or hemiarthroplasty, using a cohort of patients that was enrolled in a previous prospective study on humeral head perfusion and was consequently treated using a common conceptual approach. MATERIALS AND METHODS: Between 1998 and 2001, 98 patients with 100 fractures of the proximal humerus were treated surgically by a single surgeon with open reduction and internal fixation (ORIF) (51/100, group A, median age 54 years; range, 21-88) or with hemiarthroplasty (49/100, group B, median age 66 years; range, 38-87). Seventy-six of 98 patients were available for re-evaluation at a mean follow-up of five years (3.3-7.3) using the Constant-Murley score (CMS), the Subjective Shoulder Value (SSV), and conventional radiographs. RESULTS: The median total CMS was 77 (range, 37-98) for group A and 70 (range, 39-84) for group B. The median SSV was 92 (range, 40-100) for group A and 90 (range, 40-100) for group B. Avascular necrosis occured in 6/40 fractures treated with ORIF. CONCLUSION: Osteosynthesis and hemiarthroplasty yield similar functional results and comparable patient satisfaction following the applied decision making process in this selected patient cohort. Osteosynthesis with preservation of the humeral head is worth considering when adequate reduction and stable conditions for revascularization can be obtained. In patients with osteopenic bone and/or comminuted fractures, hemiarthroplasty is a viable alternative. LEVEL OF EVIDENCE: Level 2; Prospective non-randomized comparison study.

Zementaugmentation bei Wirbelmetastasen (Vertebro- und Kyphoplasie) [Cement injection for spinal metastases (vertebroplasty and kyphoplasty)]

Osteolytic lesions of the spine (metastasis, myeloma) can be treated extremely efficiently by percutaneous cement injection. The treatment should be restricted to osteolytic lesions of the vertebral body, and only if a relevant mechanical deterioration is present. If the pedicles and/or the lamina are involved and if there is compression of the spinal canal, the treatment is no longer appropriate. The surgical technique is similar to the treatment of osteoporotic fractures; however, there is definitely a higher risk for cement leakage and the clinical outcome is not as predictable as in osteoporotic fracture treatment. It is important to realize that cement injection per se has no impact on the tumor itself, but provides stability to the vertebral body. An osteolytic lesion without mechanical compromise does not need a vertebroplasty. Patients with tumorous lesions of the spine should be followed by an interdisciplinary team of spine surgeon, oncologist and radio-oncologist.

How to Tango: a manual for implementing Spine Tango

The generic approach of the Spine Tango documentation system, which uses web-based technologies, is a necessity for reaching a maximum number of participants. This, in turn, reduces the potential for customising the Tango according to the individual needs of each user. However, a number of possibilities still exist for tailoring the data collection processes to the user's own hospital workflow. One can choose between a purely paper-based set-up (with in-house scanning, data punching or mailing of forms to the data centre at the University of Bern) and completely paper-free online data entry. Many users work in a hybrid mode with online entry of surgical data and paper-based recording of the patients' perspectives using the Core Outcome Measures Index (COMI) questionnaires. Preoperatively, patients can complete their questionnaires in the outpatient clinic at the time of taking the decision about surgery or simply at the time of hospitalisation. Postoperative administration of patient data can involve questionnaire completion in the outpatient clinic, the handing over the forms at the time of discharge for their mailing back to the hospital later, sending out of questionnaires by post with a stamped addressed envelope for their return or, in exceptional circumstances, conducting telephone interviews. Eurospine encourages documentation of patient-based information before the hospitalisation period and surgeon-based information both before and during hospitalisation; both patient and surgeon data should be acquired for at least one follow-up, at a minimum of three to six months after surgery. In addition, all complications that occur after discharge, and their consequences should be recorded.

Challenges in evaluating surgical innovation

Research on surgical interventions is associated with several methodological and practical challenges of which few, if any, apply only to surgery. However, surgical evaluation is especially demanding because many of these challenges coincide. In this report, the second of three on surgical innovation and evaluation, we discuss obstacles related to the study design of randomised controlled trials and non-randomised studies assessing surgical interventions. We also describe the issues related to the nature of surgical procedures-for example, their complexity, surgeon-related factors, and the range of outcomes. Although difficult, surgical evaluation is achievable and necessary. Solutions tailored to surgical research and a framework for generating evidence on which to base surgical practice are essential.

Impact of surgical training on incidence of surgical site infection

BACKGROUND: Despite availability of other training forms, tutorial assistance cannot be entirely replaced in surgical education. Concerns exist that tutorial assistance may lead to an increased rate of surgical site infection (SSI). The purpose of the present study was to investigate whether the risk of SSI is higher after surgery with tutorial assistance than after surgery performed autonomously by a fully trained surgeon. METHODS: All consecutive visceral, vascular, and traumatological inpatient procedures at a Swiss University Hospital were prospectively recorded during a 24-month period, and the patients were followed for 12 months to ascertain the occurrence of SSI. Using univariable and multivariable logistic regressions, we assessed the association of tutorial assistance surgery with SSI in 6,103 interventions. RESULTS: Autonomously performed surgery was associated with SSI in univariable analysis (5.36% SSI vs. 3.81% for tutorial assistance, p = 0.006). In multivariable analysis, the odds of SSI for tutorial assistance was no longer significantly lower (Odds Ratio [OR] = 0.82; 95% Confidence Interval [CI]: 0.62-1.09; p = 0.163). CONCLUSIONS: Surgical training does not lead to higher SSI rate if trainees are adequately supervised and interventions are carefully selected. Although other forms of training are useful, tutorial assistance in the operating room continues to be the mainstay of surgical education.

Stability after bilateral sagittal split osteotomy advancement surgery with rigid internal fixation: a systematic review

PURPOSE: The purpose of this systematic review was to evaluate horizontal relapse and its causes in bilateral sagittal split advancement osteotomy (BSSO) with rigid internal fixation of different types. MATERIALS AND METHODS: A search of the literature was performed in the databases PubMed, Ovid, Cochrane Library, and Google Scholar Beta. From 488 articles identified, 24 articles were finally included. Six studies were prospective, and 18 were retrospective. The range of postoperative study records was 6 months to 12.7 years. RESULTS: The short-term relapse for bicortical screws was between 1.5% and 32.7%, for miniplates between 1.5% and 18.0%, and for bioresorbable bicortical screws between 10.4% and 17.4%, at point B. The long-term relapse for bicortical screws was between 2.0% and 50.3%, and for miniplates between 1.5% and 8.9%, at point B. CONCLUSIONS: BSSO for mandibular advancement is a good treatment option for skeletal Class II, but seems less stable than BSSO setback in the short and long terms. Bicortical screws of titanium, stainless steel, or bioresorbable material show little difference regarding skeletal stability compared with miniplates in the short term. A greater number of studies with larger skeletal long-term relapse rates were evident in patients treated with bicortical screws instead of miniplates. The etiology of relapse is multifactorial, involving the proper seating of the condyles, the amount of advancement, the soft tissue and muscles, the mandibular plane angle, the remaining growth and remodeling, the skill of the surgeon, and preoperative age. Patients with a low mandibular plane angle have increased vertical relapse, whereas patients with a high mandibular plane angle have more horizontal relapse. Advancements in the range of 6 to 7 mm or more predispose to horizontal relapse. To obtain reliable scientific evidence, further short-term and long-term research into BSSO advancement with rigid internal fixation should exclude additional surgery, ie, genioplasty or maxillary surgery, and include a prospective study or randomized clinical trial design with correlation statistics.

Landmark-based augmented reality system for paranasal and transnasal endoscopic surgeries

BACKGROUND: In this paper we present a landmark-based augmented reality (AR) endoscope system for endoscopic paranasal and transnasal surgeries along with fast and automatic calibration and registration procedures for the endoscope. METHODS: Preoperatively the surgeon selects natural landmarks or can define new landmarks in CT volume. These landmarks are overlaid, after proper registration of preoperative CT to the patient, on the endoscopic video stream. The specified name of the landmark, along with selected colour and its distance from the endoscope tip, is also augmented. The endoscope optics are calibrated and registered by fast and automatic methods. Accuracy of the system is evaluated in a metallic grid and cadaver set-up. RESULTS: Root mean square (RMS) error of the system is 0.8 mm in a controlled laboratory set-up (metallic grid) and was 2.25 mm during cadaver studies. CONCLUSIONS: A novel landmark-based AR endoscope system is implemented and its accuracy is evaluated. Augmented landmarks will help the surgeon to orientate and navigate the surgical field. Studies prove the capability of the system for the proposed application. Further clinical studies are planned in near future.

[Navigation and robotics of the lateral skull base]

Computer-aided microscopic surgery of the lateral skull base is a rare intervention in daily practice. It is often a delicate and difficult minimally invasive intervention, since orientation between the petrous bone and the petrous bone apex is often challenging. In the case of aural atresia or tumors the normal anatomical landmarks are often absent, making orientation more difficult. Navigation support, together with imaging techniques such as CT, MR and angiography, enable the surgeon in such cases to perform the operation more accurately and, in some cases, also in a shorter time. However, there are no internationally standardised indications for navigated surgery on the lateral skull base. Miniaturised robotic systems are still in the initial validation phase.

[Juvenile chronic arthritis: a rare disease with potentially serious consequences]

The term juvenile chronic arthritis covers several nosological entities with very different clinical presentation, course and prognosis. This review addresses non-rheumatologists and non-pediatricians. Diagnostic criteria, clinical presentation of the most common nosological subgroups and relevant investigations are spotlighted. Therapeutic guidelines are presented, bearing in mind, that for each child an individual interdisciplinary plan has to be elaborated. This would involve close cooperation between the pediatrician, the pediatric rheumatologist, the family doctor, parents and, if necessary, the physiotherapist, ergotherapist, social worker, ophthalmologist, orthopedic surgeon and school teachers. It is essential that each member of this therapeutic team reports regularly.

Prognostic clinical and radiological parameters for immediate facial nerve function following vestibular schwannoma surgery

OBJECTIVE: The paper aims to define the parameters available before surgery which could predict immediate facial nerve function after excision of a vestibular schwannoma (VS). METHODS: Ninety-nine patients with VS operated consecutively by a single surgeon using an identical surgical technique have been evaluated retrospectively. Data were collected regarding patients' sex, age at onset of symptoms and at surgery, initial symptoms, neurological status at presentation, early post-operative neurological status and complications. The main radiological parameters included in the study were tumour extension pattern, diameters, shape, and volume, as well as extent of bony changes of the internal auditory canal. RESULTS: As the tumour stage and volume increase, facial nerve function is worse after surgery (p < 0.001 and p < 0.05, respectively). Concomitantly, larger extra-meatal tumour diameters in three dimensions (sagittal, coronal and axial) led to worse function (p < 0.01). Anterior and/or caudal tumour extension (p = 0.001 and p = 0.004, respectively) had more significant correlation than posterior and/or cranial extension (p = 0.022 and p = 0.353, respectively). Polycyclic VS had the worst prognosis, followed by the tumours with oval shape. The extent of intra-meatal tumour growth does not correlate with immediate facial nerve outcome. The different angles, lengths and diameters of the internal auditory channel showed no significant correlation with facial nerve outcome. Patients with headache as an initial symptom and those with gait instability and/or pre-operative poor facial nerve function had significantly worse immediate facial nerve outcome. CONCLUSION: Our data suggests that the analysis of the radiological and neurological patient data prior to surgery could give reliable clues regarding the immediate post-operative facial nerve function.

Is carotid endarterectomy a trainee operation?

BACKGROUND: Recent dramatic changes in surgical training resulting from working-hour regulations may lead to lack of competence. Traditionally, carotid surgery has been the domain of specialists. This study was designed to compare the outcome of carotid endarterectomy performed by vascular surgical trainees versus vascular surgeon (VS). METHODS: A retrospective study of 1,379 consecutive patients who underwent carotid endarterectomy as the sole procedure under local or general anesthesia (from 1995-2004) was performed. All patients were admitted to the intensive care unit for 24 hours. Trainees performed 475 (34.5%) and vascular specialists performed 904 (65.5%) operations. RESULTS: Patient characteristics with regard to preoperative neurological status were similar. Trainees operated on 61.4% symptomatic patients and VS on 56.8% (P = 0.09). Shunt use did not differ (16% trainee vs. 17.8% VS). Clamping time and total operating time were longer among trainees (41.9 vs. 33.5 min, P < 0.001; and 121.2 vs. 101.8 min, P < 0.001, respectively). Postoperative stroke and death rates (3.2% vs. 3.1% and 0.4% vs. 0.9%, respectively) did not differ. Peripheral nerve complications were more common among trainees (12.2% vs. 6.5%; P < 0.0001); 99.6% of these nerve injuries had resolved at 3 months' follow-up. CONCLUSIONS: Carotid endarterectomy can be performed safely by a trainee vascular surgeon when assisted and supervised by a specialist vascular surgeon.