Evaluation of an in situ setting injectable calcium phosphate as a new carrier material for gentamicin in the treatment of chronic osteomyelitis: studies in vitro and in vivo.

A study was performed to investigate the effectiveness of hydroxyapatite cement (HAC) as a new carrier system in the treatment of chronic, posttraumatic osteomyelitis. In the in vitro study, release of gentamicin from standard cylinders of HAC were measured by agar diffusion test. As a representative for mechanical properties, compression strength was measured in order to detect changes when mixing HAC with gentamicin. In the in vivo study, bone infection was induced according to the model of Norden by injection of 1 ml Na-morrhuat and 3 x 10(6)CFU Staphylococcus aureus. After 3 weeks, when chronic stage of infection was obtained, 17 animals were treated by debridement and filling the marrow either with HAC alone or HAC mixed with gentamicin (32 mg/g). Animals of the control groups were left untreated. After 6 weeks, all animals were sacrificed. Hematological, radiological, microbiological and histological examinations were carried out by covered investigation. Best evidence of the efficiency of treatment was observed in histopathological and microbiological findings. In all swabs of the control groups, taken 6 weeks following infection S. aureus were detected which were clonal to the strain used for induction of osteomyelitis. In HAC/gentamicin-treated animals, no growth was detectable after 7 days of culturing in BHI bouillon. In the HAC/gentamicin-treated group, there was no histopathological evidence of infection. In all other groups different stages of chronic osteomyelitis were found. No side effect was observed, neither locally nor systemically by HAC or gentamicin. Therefore, HAC is considered to be a very effective carrier for antibiotics in treatment of chronic, posttraumatic osteomyelitis.

[A new irrigation-suction boring system facilities low-pressure intramedullary boring of isolated swine femurs]. / Ein neues Spül-Saug-Bohrssystem ermöglicht die druckarme Markraumbohrung an isolierten Schweinefemora.

AIM: Intramedullary nailing is the treatment of choice for the stabilization of fractures of long tubular bones. An important disadvantage of this method is the increase in intramedullary pressure and the resulting release of fat into the venous blood system during reaming of the medullary canal. We have developed a new type of rinsing-suction-reamer (SSB) in order to minimize these disadvantages. Trials were initiated to investigate whether it is possible to ream the medullary canal with the SSB without pressure increase in comparison with the standard AO-reamer (AOB). METHODS: Reamed intramedullary nailing was performed in 20 isolated pig femora. The intramedullary pressure was recorded continuously. RESULTS: While stepwise reaming was performed, the pressure only rose above the physiological level in AOB. During insertion of the guide wire and the nail, comparable values were measured for AOB and SSB. CONCLUSION: Our experiments show that reaming of the medullary canal is possible without a pressure increase using the SSB in comparison with AOB.

The use of an in situ curing hydroxyapatite cement as an alternative to bone graft following removal of enchondroma of the hand.

Following curettage of enchondromata of the phalanges we filled the resultant bone cavity with hydroxyapatite cement in eight patients to avoid cancellous bone grafting. This material differs significantly from the ceramic hydroxyapatite commonly used in clinical practice. It is produced by the combination of two calcium phosphates which, in the presence of water, form a paste that cures to a solid implant with a microporous structure. Like ceramic hydroxyapatite, this cement is highly biocompatible and does not provoke a foreign body giant cell reaction, a sustained inflammatory response or a toxic reaction. We performed a prospective study with X-rays and clinical assessment up to 1 year after the operation. There were no complications, and all patients regained full function of the hand.

[Callus distraction of the first metacarpal bone for thumb reconstruction after traumatic amputation]. / Die Kallusdistraktion des ersten Mittelhandknochens zur Daumenrekonstruktion nach traumatischer Amputation.

From 1990 to 1997, callus distraction of the first metacarpal bone was performed on 34 patients with a traumatic amputation of the thumb, if replantation was not possible. After a period of 7 +/- 11 months (range, 1-48), a corticotomy and continuous distraction with an external fixator was carried out. Of the patients, 31 (91%) were reviewed after treatment. The follow-up period range was 41 +/- 32 months. With this method, the average lengthening of the thumb was 78% in comparison to the uninjured side. Complications were rupture of the callus in one case, four patients suffered a superficial wound infection, and seven patients showed pin tract infection without osteitis. At follow-up examination, 20 patients (64.5%) showed excellent, 9 (29%) good and 2 patients (6.5%) unsatisfying results.

[The treatment of unstable fractures of the distal radius using a bridging external fixator. Results from a long-term evaluation]. / Die Behandlung instabiler distaler Radiusfrakturen mit einem transarticulären Fixateur externe. Ergebnisse einer Langzeitbeobachtung.

INTRODUCTION: The aim of our study was to evaluate external fixation in the treatment of unstable distal radius fractures in a long-term follow-up. METHODS: Within 8 years 174 patients with severely displaced distal radius fractures were included in a prospective study and treated with an external wrist fixator (Orthofix Srl, Italy). A total of 148 patients were reviewed with an average follow-up time of 28 months. RESULTS: Using the functional outcome score according to Gartland and Werley, we obtained 29.3 % excellent, 42.5 % good, 10.3 % fair and 2.9 % poor results; 14.9 % of the patients were not available for follow-up. Additional procedures were carried out in 54.1 % to obtain dorsal stabilization. The list of complications included two major pin-tract infections requiring surgical intervention, one pin cut out of the second metacarpal bone, one fixator dislocation, and one patient had algodystrophy. The length of the radius and joint congruity did not significantly from the situation when the fixator has been removed at the end of the treatment. CONCLUSION: The results show the importance of anatomical reduction, and especially restoration of radial length, in order to obtain good functional outcome.

[Effect of external stabilizing agents of the ankle joint on sports motor capacities in one legged jumping]. / Einfluss von externen Stabilisierungshilfen am Sprunggelenk auf sportmotorische Fähigkeiten beim Einbeinsprung.

UNLABELLED: In order to document sport specific skills, 23 athletes with functionally unstable ankle joints as well as 18 healthy volunteers were evaluated by performing a single leg jumping test. For external stabilization of the ankle an Aircast-Brace, a Ligafix-Air-Brace, a Malleoloc-Brace as well as a tape bandage were applied. There was no negative influence on the jumping performance of the tested stabilizing devices in the uninjured ankle joints. There was also no significant difference between the devices. For functional unstable ankle joints most of the devices showed significant improvement of jumping performance. The best results were achieved by the Aircast-Brace, followed by the Malleoloc-Brace, the Ligafix-Brace and the tape bandage. Again, there was no significant difference between these devices. While the reaction time showed no difference in all test situations, the time for stabilizing the ankle joint was significantly worse in those ankle joints without a brace. CLINICAL RELEVANCE: For athletic activities, which are dominated by movement patterns comparable to the applied jumping test, the tested stabilizing devices seem to have no negative effect on sports specific capabilities.

Influence of external stabilizing devices of the ankle on sport-specific capabilities.

We compared sport-specific-skills in 23 athletes with functionally unstable ankle joints to those of 18 healthy volunteers by performing a Japan test as well as a specially designed single-leg jumping test. For external stabilization of the ankle, an Aircast brace, a Ligafix Air brace, a Malleoloc brace and a tape bandage were applied. For the Japan test in the group with uninjured ankle joints, the best results were obtained when wearing the Aircast brace, followed by tape bandage, Ligafix brace and no stabilizing device in descending order. The worst results were presented by the group with the Malleoloc brace. However, there were no significant differences among these devices. In the group with functionally unstable ankle joints, the best score was achieved with the tape bandage, followed by the Ligafix brace, Mallcoloc brace and Aircast brace. The unstabilized group showed significantly worse results compared with all other groups. In the single-leg jumping test, the stabilizing devices had no negative influence on the jumping capability in the uninjured ankle joints. Additionally, there was no significant difference among the orthoses. Volunteers with unstable ankle joints experienced a significant improvement of jumping performance with most of the devices. The best results were achieved with the Aircast brace, followed by the Malleoloc brace, Ligafix brace and tape bandage. However, there was no significant difference among these orthoses. While the reaction time of the volunteers was the same for all test situations, the time for dynamically stabilizing the ankle joint appeared to be significantly worse in those ankle joints without a brace. For athletic activities, which are dominated by movement patterns comparable to the Japan test as well as the jumping test used, these stabilizing devices seem to have no negative effect on sport-specific capabilities.