[Transarticular fixation of C1-C2: a multicenter retrospective study]. / Transartikulární fixace C1-C2: multicentrická retrospektivní studie.

PURPOSE OF THE STUDY: Transarticular C1-2 fixation is a surgical alternative in treatment of atlantoaxial instability. Although the method provides very good immediate and long-term stability, it still involves several disadvantages. The group of patients as reported from various institutions are usually very small and hardly comparable. In order to objectively compare the results of the method, we collected the groups of patients treated in four institutions dealing with surgery of the cervical spine in Czech Republic. MATERIAL AND METHODS: During the 9-years period (1993-2001), the transarticular C1/2 fixation was performed in 80 patients (mean age 45.6 years, range 4-85 years). The procedure was indicated for atlantoaxial instability due to rheumatoid arthritis in 32 cases, pseudoarthrosis of the odontoid process in 15 cases, fracture of the odontoid in 8 cases, complex C1-C2 fracture in 7 cases, tumour in 5 cases, C1 fracture in 4 cases, os odontoideum in 3 cases, purulent osteolysis of the odontoid in 3 cases and instability due to tuberculosis in one case, respectively. Two patients underwent surgery for painful arthrosis of atlantoaxial joints only. Transarticular fusion was combined with posterior interlaminar fixation using autologous graft and wire in most of the cases. Clinical and radiological results were evaluated in the early postoperative period and 3, 6 and 12 months after surgery, respectively. The position of the screws in relation to lateral mass of the atlas was evaluated according to our own criteria as optimal, suboptimal, and misplaced. Long-term postoperative stability and bone fusion were also followed. The follow-up ranged from 3 to 99 months (mean 29.1 months). There were 72 patients available for long-term follow-up (i.e. more then 6 months). RESULTS: We inserted 150 screws; two screws were used in 72 patients, one screw in 6 patients while in two patients, the surgery had to be aborted without screwing. Optimal placement was achieved in 103 cases (68.7%), suboptimal because of too medial or lateral placement of the screws in 26 cases (17.3%), suboptimal due to a short screw in 9 case (6%) and a long screw in 8 cases (5.3%). Four screws (2.7%) were found misplaced (i.e. out of the lateral masses). Fusion was confirmed in 51 cases out of 72 operated on (70.8%) at 6-months follow-up, and in 55 cases out of 63 available for follow-up (87.3%) at 12 months, respectively. Segmental stability was achieved in all patients, even in cases with incomplete fusion as seen on radiograph. Furthermore, six screws in four patients were discovered to be broken, nevertheless without any clinical consequences. There were 4 cases of peroperative injury to th vertebral artery (i.e. 5% of patients, 2.7% of screws), one case of dural tear and one case of excessive blood loss from epidural venous plexus. These complications, however, did not cause any significant clinical consequences, either. Other postoperative complications included wound dehiscence in 3 cases, 2 cases of hardware failure due to wrong indication for surgery and 2 cases of persistent neck pain. DISCUSSION: Transarticular C1/2 fixation is known to be universal and stable technique suitable for the treatment of atlantoaxial instability. According to biomechanical studies, this method provides the best stability mainly in rotation and lateral flexion (inclination) when compared to other described methods of atlantoaxial fixation. The fusion rate is reported to vary between 90 to 100% if the posterior interlaminar fusion using bone graft and wire is simultaneously performed. The rare incidence of pseudarthrosis is usually considered to be related to a poor surgical technique as even only one screw should provide bone fusion if properly placed. Using strict evaluation criteria, the fusion rate in our sample of patients was 87.3% at 12 months, or, 92.1% if also controversial radiographs were included. The injury to the vertebral artery is the most serious complication of the method; its incidence in our group (5% of patients) is comparable to data from literature. We believe that most of these events happened because of individual anatomical variations of axis and vertebral artery were not adequately respected. CONCLUSION: Transarticular technique of instrumental atlantoaxial fusion is an effective method with multiple application in treatment of craniocervical and upper cervical spine instability. The gain of immediate stability with acceptable risk of possible complications is the major advantage of this procedure. The results of our multicentric retrospective study confirm the expected high fusion rate and are comparable to previously published reports.

[Primary osteosynthesis of the odontoid process: a multicenter study]. / Prímá osteosyntéza dentu--multicentrická studie.

PURPOSE OF THE STUDY: Direct osteosynthesis is a method of choice for the treatment of odontoid process fractures. It is based on insertion, from the anterior approach, of one or two screws from the C2 body into the apex of the odontoid across the fracture line. The tensile action of screws results in compression of fragments and stabilization of the fracture. The aim of the study was to evaluate a group of patients treated by this method and to compare our results with those reported in the foreign literature. MATERIAL: A total of 99 patients were treated by direct osteosynthesis of the odontoid in the departments involved in the study between 1994 and 2001. METHODS: Patients indicated for this surgery were those with fractures of type II according to Anderson and D'Alonzo and those with type III fractures but only when the fracture line went across the articulation surfaces of C1-C2, when closed reduction was not possible or the patients were not indicated for halo fixation. Direct osteosynthesis was not applied to fractures with comminution at the base of the odontoid, irreducible fractures, odontoid fractures combined with dislocated fractures of the atlas or pathological fractures. Severe kyphosis of the cervical spine or a large thoracic cage was also regarded as a contraindication. RESULTS: All the 99 patients were followed up from 3 up to 102 months, with an average of 28.5 months; only in seven patients, the follow-up period was shorter than 6 months. The most frequent subjective complaint was a painful operation wound. This usually resolved within two weeks of surgery. Except for four patients, alle were satisfied with the outcome. Type II fractures were diagnosed in 84 and type III fractures in 15 cases. A total of 174 screws were inserted into the odontoid processes of 99 patients. A single screw was used in 25 and two screws in 73 patients. In one case, three screws had to be inserted. Screw lenght ranged from 36 to 44 mm, diameter was 40.9 mm. Three months after surgery, X-ray examination, both in flexion and extension, did not reveal any instability in any of the patients. No morphological change in the C2-C3 intervertebral space was observed Of 92 (92.9%) paitents under longterm follow-up, 84 (91.3%) showed complete healing of the fracture, three died and five patients eventually developed pseudoarthrosis, which was due to a broken screw in three of them. This condition was treated by dorsal fixation of C1-C2 according to Magerl or by one of the dorsal cerclage techniques. The group was free of any perioperative complications related to the anterior approach or injury to nerve structures by screws. DISCUSSION: The most frequent subjective complaint was a painful operation wound. Treatment of odontoid fractures varies according to the type of injury, bone quality and also practice at each department. Type II injuries are highly unstable and, because of the small fracture surface, their healing ability is much lower than in type III fractures. Previously, most of the patients with odontoid injuries were treated conservatively by immobilization in a plaster cast or a brace or, later, by a halo device. In the long term, however, they showed a high proportion of pseudoarthroses (10 to 100%). Direct osteosynthesis of the odontoid by screws permits the maintenance of rotation of the C1-C2 mobile segment. We followed the scheme of indications used abroad but did not perform osteosynthesis to correct pseudoarthrosis. The number of osteosyntheses healed (91.3%) was also in agreement with the literature data. Earlier, we used two screws for all types of fractures. Recently, we have preferred insertion of a single screw in type II and III fractures in narrow odontoids. In the later, there is no danger of rotational dislocation during screw insertion; to insert one screw from the centre of the C2 base is easy and speeds up the procedure. However, in displaced type II and type II T fractures, two screws are a necessity. Similarly to other authors, we recorded a slight limitation of cervical spine rotation in patients at long-term follow-up, particularly in elderly subjects with advanced osteochondrosis. No complications leading to deterioration of the patient's state were recorded. CONCLUSIONS: Direct osteosynthesis is a method of choice for most of the type II and indicated cases of type III fractures of the odontoid process of the axis. This surgical procedure facilitates restoration of anatomical conditions of the spine and its immediate stability. Consequently, patients can be readily mobilized and rehabilitated.

[Subdural empyema. Present possibilities of diagnosis and therapy]. / Subdurální empyém. Soucasné moznosti diagnostické a lécebné.

The authors give an account of their experience with the diagnosis and treatment of subdural empyema. In 1953-1991 in the neurosurgical department in Olomouc a total of five patients with this diagnosis were treated. None of them died. In all patients before operation symptoms of meningeal irritation, fever and in four patients a focal neurological symptomatology was observed. The authors reached the conclusion that the best surgical approach is craniotomy or craniectomy which should be preferred to minor surgical operations. Treatment of the primary inflammatory focus leading to the development of subdural empyema must be part of the intracranial operation. Regular postoperative follow-up of the patient by means of CT makes it possible to detect in time relapses and leads to early surgical operation. The authors mention experience focused on possible errors in the CT diagnosis. The creation of the picture of subdural collection precedes oedema of the hemisphere with a shift of the structures in the median line. The subdural collection occurs in the subsequent stage of development of the disease.

Current possibilities of diagnosing syringomyelia.

The diagnostic contribution of radiological examinations to the verification of the diagnosis of syringomyelia is assessed. A case report of the authors' own patient is given with the diagnosis confirmed by nuclear magnetic resonance.