Objective

Ankle fractures are frequent and seem to be easy to handle in most cases. Of course, also these easy fractures can cause infections that must be carefully managed. What risk factors do we find? What options do we have in treating these complications? What are the consequences and what will the result for the patient be like, compared to non-infected cases?

In a retrospective study we included 82 patients treated with an osteosynthesis in ankle fractures (AO 44 B or C fractures). Average age was 52.4 years (range 20–84 years, median 51.0).

Purpose

In stabilisations of atlantoaxial instabilities it holds risks to injure the A. vertebralis as well as neurological structures. Furthermore the posterior approach of the upper part of the cervical spine requires a huge and traumatic preparation of the soft tissue. However the anterior transarticular C1-2 fusion (ATF) is less traumatic and offers almost the same strengh of the stabilisation.

Introduction: In recent years, navigated surgical procedures in spinal surgery have been established due to an increasing demand for precision. Especially 3D-C-arms connected with navigation systems are being used more often and can be utilized intraoperatively for planning as well as controlling of screw positions. This study analyses our experiences with 3D-based navigation in the posterior cervical and high thoracic spine.

Methods: A 3D-C-Arm (Vision Vario 3D, Ziehm) was connected with a navigation system (Vector vision, Brainlab) and since 10/2007 used for the placement of overall 350 Screws at 51 Patients. Of those 9 Patients had to undergo operations in the posterior cervical spine, of 53 screws Judet- (n=8), Massa lateralis- (n=27) and pedicle-screws (n=18) were placed. Indications for instrumentation were traumatic fractures (n=3), spon-dylodiscitis (n=1), multiple metastases with high-grade instability (n=4), and degenerative rheumatic stenosis of the spinal canal (n=1). Concerning the high thoracic spine (T1–10) 42 interventions were made with the method, 297 pedicle- screws were implanted. Indications in this area were traumatic fractures (n=24), metastases (n=14) and spondylodiscites (n=4).

Results: Scan-time intraoperatively took 60 seconds on average, data-transfer to the navigation-system another 10 seconds. Application-time including anti-collision-check needs approx. 6 minutes [5;18]. In total 260/350 (74%) screws could be inserted assisted with navigation, 194/350 (55%) were controlled intraop-eratively. Regarding the cervical spine in 44/53 (89 %) of the screws the navigation procedure was uneventful. Positioning of 37/53 (70%) of the screws was checked immediately postoperatively. In the upper thoracic spine 216/297 (73%) could be placed with navigation, 157/297 (53%) were controlled intraoperatively. Occasionally, scan-setup was problematic, in addition, we experienced technical problems. Correct placement was seen for each screw, thus correlating well with the intraoperative findings.

Conclusions: The application of the combination of intraoperative 3D-imaging and navigation for posterior instrumentation of the cervical and the upper thoracic spine is technically feasible and reliable in clinical use. User- and software-dependant sources of error could be solved during the first course of the series. Image-quality at the cervical spine is depending on individual bone density, and possible metal artifacts. With undisturbed visibility of the vertebral body, the reliability of 3D-based navigation at the cervical spine is comparable to that of CT-based procedures. Additionally, it has the advantage of skipping preoperative acquisition of data as well as the matching-process. Furthermore, exposure to radiation is reduced due to the possibility of sparing pre- and postoperative CT.

Purpose: The posterior transarticuar screw fixation C1-2 (Magerl) is a demanding procedure to treat atlanto-axial instabilities. In spite of a high primary instability it holds risks to injure the A. vertebralis as well as neurological structures. Furthermore the posterior approach of the upper part of the cervical spine requires a huge and traumatic preparation of the soft tissue. However the anterior transarticular C1-2 fusion is less traumativc and offers approximately the same strengh of the stabilisation.

Methods: Since the beginning of 2007 17 multimorbid patients with atlanto-axial instabilities of different entities were treated via the anterior transarticular fusion, were regular examined radioogicaly (x-ray/CT) and the procedure critically judged.

Results: C1-2 fusions were performed in 17 patients (13f, 4m, average 81,6 years (68.95)). The main symptoms was pain radiating in the upper cervical spine and the occiput, 2 Patients complaining radiating pain with paraesthesia in both upper extremities, whereas the neurology was predoinant inconspicious. The average operation-time took 64,5 min. On the left side the screws of Ø 39,5mm (32–44mm), on the right side of 36mm (32–44mm) were inserted in addiction to the point of access and the angle of insertion (mediolateral angle Ø 32,0°, ventrodorsal Ø17,6°). There were no intraoperative complications concerning the ceratin procedure, postoperative one revision had to be done because of p.o. bleeding, another because of screw dislocation with clinical relevance 21 days after the first operation. The postoperative x-ray and CT control of the upper cervical spine showed 21/34 screws in 17 patients in correct position (61,7%), 7 (20,6%) screws were too long, 6 (17,7%) screws were placed too anterior and too medial compared to the oppinion of literature. position in the literature. 3 additional positionated dens-screws were in correct position. After a clear learning curve both screws of the 6th patient were positoinated correct. In this connection it could be shown, that two aspects are important for success: A correct entry point as well as the right insertion of the angle of the screws in the coronar and sagittal view. A low intraoperative blood loss, a non traumatic access as well as an immediate postoperative pain decrease have to be valued positively for this procedure.

Conclusions: The gentle procedure of the anterior transarticular C1-2 fusion requires-despite of the huge experience in anterior surgery of dens fractures – a learning curve, because of the more proximate insertion point, the flat insertion angle and the closeness of the A. vertebralis. If these aspects are going to be noticed, failed screw positioning and excessive length as well as injuries of the A. vertebralis can be avoided.

Introduction: In kyphoplasty and vertebroplasty, polymethyl methacrylate (PMMA) is currently the standard in augmentation materials but it is characterized by a lack of osseointegration and limited biocompatibility. At the same time, calcium phosphate cements are not currently considered an alternative due to their insufficient mechanical stability against shear, compression and extension forces. This prospective study examines the suitability of a new calcium alumiate ceramic (Xeraspine^®, Doxa) for augmentation of vertebral fractures treated with balloon-kyphoplasty.

Methods: The operation technique follows the standard protocol for a bilateral percutaneous balloon-kypho-plasty (Kyphon). Exclusion criteria were: additional instrumentation, age > 90 years, as well as cardiac arrhythmia. The following clinical and radiological data were collected pre and post op, as well as after 6 weeks: Visual-Analogue-Score, Oswestry-Index, bisegmental endplate angle, and vertebral hight. A CT- scan was provided to show possible cement extrusion and disintegration.

Results: 20 vertebrae were included so far. The fractures could be classified as: type A1.3 (n=11), A3.1 (9). They were located at Th9 - L3. All 20 patients reported pain relief immediately post op. Restoration of endplate angles was 6,2° on average. There was no case of cement disintegration. No loss of correction was observed radiologically.

Discussion: The calcium aluminate ceramic used in balloon-kyphoplasty is an alternative to PMMA. Due to comparable shear, compression and extension strengths, there is no risk of cment breakage and following loss of correction. On the other hand the calcium aluminate ceramic shows better biocompatibility if compared to PMMA.

Objective: 36 patients (male:female= 26:10, mean age 40.6 years) with ankle fractures treated with osteosynthesis including a syndesmotic screw were enrolled in this prospective study. Instability of the distal syndesmosis was proven intraoperatively and then a quadricortical syndesmotic screw was placed.

Patients were mobilized with an AirCast^® ankle brace and cranes for six weeks, then the syndesmotic screw was removed and patients started full weight bearing.

Using the x-rays of the ankle before and after and the CT of both ankles before removal of the syndesmotic screw we evaluated the radiologic results: the syndesmotic interval in the axial cuts, the Espace claire de Chaput (total clear space, TCS) und the medial clear space (MCS). Ventralization of the fibula as a measurement for the position of the fibula in the incisura was defined as the difference between the vertical reference lines of tibia and fibula in the CT. The functional results were evaluated by the scores of Phillips, Olerud/Molander and Weber.

Results: The mean axial interval difference was 0.83 mm (range -2.6 – 4.5), in seven case (19.4%) the interval had been over corrected. There was one case of subluxation of the talus (2.8%). In 3 patients (8.3%) the syndesmotic screw had been corrected in a second operation after the first CT, in 2 cases (5.6%) the syndesmotic screw had been placed after there was suspection of syndesmotic insufficiency in the x-rays which had been verified by CT. Mean ventralization of the fibula was 2.3mm (range 0–6.4). Average TCS was 5.3 mm (range 3.0 – 8.8), mean MCS was 3.3 mm (range 1.0 – 8.2).

The functional scores showed good to very good results in most patients.

Conclusions: Only with CT, the correct placement of the syndesmotic screw can be verified, the syndesmotic interval in the axial cuts can be evaluated and the position of the fibula in the Incisura fibularis can be assesed, therefore CT should be postoperative standard after syndesmotic screw placement. If an ankle fracture has not been treated with a syndesmotic screw, postoperative CT of both ankles should be done in any radiological or clinical suspicion of syndesmotic insufficiency.

Objective: 15 patients (male:female= 9:6, mean age 39,5 years) with ankle fractures treated with osteosynthesis including a syndesmotic screw were enrolled in this prospective study. Instability of the distal syndesmosis was proven intraoperatively and then a tricortical syndesmotic screw was placed.

Patients were mobilized with an AirCast®e brace and cranes for six weeks, then the syndesmotic screw was removed and patients started full weight bearing. Follow-Up was 21.7 weeks mean after removal of the syndesmotic screw.

Using the x-rays of the ankle after and the CT of both ankles before removal of the syndesmotic screw we evaluated the radiologic results: the syndesmotic interval in the fontal and axial cuts, the Espace claire de Chaput (total clear space, TCS) und the medial clear space (MCS). The functional results were evaluated by the scores of Phillips, Olerud/Molander and Weber.

Results: The mean frontal interval difference was 0,3 mm und the mean axial interval difference was 0,5 mm, in one case Fall (6,7%) there was a axial interval difference of 2 mm and in one case the interval had been over corrected. There was no subluxation of the talus in any patient. In 3 patients (20%) the syndesmotic screw had been placed in a second operation, after there was suspection of syndesmotic insufficiency in the x-rays which had been verified by CT. After implantation of the screw the CT scan showed regular syndesmotic intervals. Average TCS was 5.3 (range 3.40 – 7,40), mean MCS was 2.2 (range 1.0 – 4.5).

Average functional scores were: Phillips 118.53 (range 53 – 135), Olerud/Molander 93 (range 60 – 100) and Weber 2.33 (range 0 – 12).

Conclusions: Only with CT, the correct placement of the syndesmotic screw can be verified, the syndesmotic interval in the axial cuts can be evaluated and the position of the fibula in the Incisura fibularis can be assesed, therefore CT should be postoperative standard after syndesmotic screw placment. If an ankle fracture has not been treated with a syndesmotic screw, postoperative CT of both ankles should be done in any radiological or clinical suspicion of syndesmotic insufficiency.

Introduction and purpose: Primary instability and subsidence of hip implants is a very common problem. What is the load on a locking screw?

Materials and methods: Helios® modular prosthesis (IQL / Biomet España) with distal holes (static/dynamic). Fifty patients (46%) with locking, total n=109 (26 of 67 with FX of proximal femur, 14 of 25 aseptic loosening cases and 13 of 17 with periprosthetic fractures). Experimental study: stress on the distal locking screws. Loads applied in 9 cadavers with 3 types of simulated fractures: group I, femoral neck; group II, intertro-chanteric; and group III, subtrochanteric. Imitating slow, normal and fast walking, sitting down and standing up, going up an down stairs (Zwick Z010 and screw capacity meter).

Results: Follow-up 6–18 months. 50 with distal locking (20% dynamic, 80% static): 13 screws removed between 6 and 12 weeks (7 in revisions, 3 in FX, 3 others).

Subsidence: 80% 1–2 mm, 14% 3–5 mm, 6% 6 mm or more.

Experimental study: Weight-bearing: group I, 40.89% (max. 78.61%); group II, 43.15% (max 90.84%); group III, 64.49% (max. 136.74%). No torsional stress. Maximum stress when walking fast and climbing stairs.

Conclusions: When bone consolidation occurs in 6 to 12 weeks, distal locking ensures sufficient reinforcement and prevents movements of over 30 μm. If more time is needed for proximal bone integration, shaft fixation is preferable. The Helios® system provides both solutions satisfactorily.

Endoscopic techniques lead to higher numbers of anterior procedures to the vertebral column. Navigation systems can assist to more precision using less x-rays. We registered prospectively more than 100 cases of anterior stabilization of the thoracic and lumbar spine using minimally invasive technique, endoscopic assistance and CT-based navigation. Patients were observed continuously over a time period of at least 12 month according to a standardized protocol.

135 patients were recorded prospectively between January 2002 September 2004. All patients recieved anterior procedures using endoscopical assistance. Operations were performed in prone position using Synframe® and navigation system by BrainLab®. The follow up of at least one year consisted in clinical investigations and radiographs 6 weeks, 3, 6, 9 and 12 months post OP.

87 male and 48 female patients were recorded with a mean age of 41 (16–77) years. 47 isolated anterior and 88 combined antero-posterior spondylodeses were performed with the described technique. In 101 cases thoracoscopy was used. For the instrumentation of L3, mini-lumbotomy was necessary which was also combined with Synframe® and endoscopical assistance. Isolated anterior procedures were completed under navigation control in 29 and combined antero-posterior procedures in 71 cases. Image intensifier times were reduced up to 85%, op-times were shortened using navigation for a mean of 22 minutes.

Navigation procedures showed initial learning curve. However, after this initial time it was a useful techique to enlarge precision and reduce op-times as well as x-ray exposition. The further standardization of the procedure lead to the development of advantageous instruments that further on will lead to even higher acceptance of this new technique.