The use of the Dynastab K external fixator in the treatment of the tibial plateau fractures

The aim of the study was the assessment of the clinical use of Dynastab K (knee) external fixator in the treatment of intraarticular fractures of the proximal tibia.

The study was conducted in the Department of Orthopaedics and Rehabilitation Warsaw Medical University. Between November 2004 and December 2007, 29 patients were included in the study (12 females and 17 males). In the experimental group, consisting of 15 patients (7 females and 8 males) open reduction and fixation of the fracture was performed. After that Dynastab K external fixator was implanted to the femur and tibia with the use of pins. On the second day after the surgery rehabilitation of the knee joint was started. Fixator was being held on the lower limb for 6 – 8 week. In the control group (14 patients – 5 females and 9 males) after open reduction and fixation of the fracture, knee orthosis was applied. Orthosis was set up in 15 degrees flexion. After that time the rehabilitation was started. The final follow up visit was performed about 34 weeks after the surgery.

The amount of articular depression, the range of motion of the knee joint, the amount of pain and the condition of soft tissues around pins were assessed during the study. The clinical and radiological outcomes were determined according to Rasmussen’s system and the condition of soft tissues with the use of Dahl’s scale. Resnick and Niwoyama criteria were used for grading of post-traumatic osteoarthrosis and Visual Analogue Scale for pain intensity. Subjective evaluation of knee function was performed by the self-made scale.

There were no statistically important differences in the amount of articular depression before the operation, after reduction and on the last follow-up visit, between the experimental and control group. The mean range of motion of the knee joint was 127,5 degrees in the experimental group and 118,3 degrees in the control group. In the experimental group the amount of pain around the knee was gradually diminished after the operation, whereas in the control group the amount of pain was sharply reduced, but after unblocking the orthosis rised significantly. There were not noticed any pin site infection. 10 patients (66,7%) from the experimental group and 7 (50%) from the control group achieved very good results in the radiological scale. The results in the clinical scale were very good at 6 patients (40,0%) from the experimental group and at 3 patients (21,4%) from the control group. During the last follow-up visit the subjective evaluation of the knee joint function was 0,64 points better in the group treated with the Dynastab K external fixator.

Background. Tibial pilon fractures lead to complicated therapeutic problem. Application in these cases of external fixators which are composed of an active articulated joint hinge imitating movement in the region of upper ankle joint, which allows plantar and dorsal flexion, leads to functional treatment of distal tibia fractures.

Aim. The aim of the study was to present the four year experience with an evaluating biomechanical parameters, medical properties and clinical usefulness of the external fixator Dynastab-S in the treatment of tibial pilon fractures.

Material. Observations were based on patients hospitalized in Orthopedic and Rehabilitation Department of Medical University of Warsaw in a period from March 2000 to August 2004. The average period of observations was 29 months. Inclusion criteria were based on the algorithm which was created in our department.

Results. The assessment of biomechanical parameters of bone-fixator arrangement proved usefulness and safeness of the external fixator Dynastab-S. The positive results of clinical examinations, X-ray examinations and subjective opinion of the patients encourages to wide use of the external fixator Dynastab-S in the treatment of tibial pilon fractures.

Aims: The purpose of this work is to present regenerative potential of bone marrow-derived mesenchymal progenitor cells (MPC) combined with biodegradable matrices in goat knee osteochondral defect. Methods: Adult goat’s bone marrow aspirates where fractionated and adherent cultures were established. After two weeks of culture, nearly confluent cells were detached and resuspended to concentrations of 10 x 106 cells/mL. Cells were loaded onto PGA-PLLA scaffolds with negative pressure to allow uniform distribution. Such autologous constructs were incubated and than implanted into osteochondral knee defects. Empty scaffolds served as a control in contralateral knee. At the time of implantation (time “zero”), replicate scaffolds were evaluated for histological appearance. After 4 and 12 weeks, implants were removed and evaluated by the tissue scoring system. Results: Time “zero” histology revealed uniformly distributed cells. At 4-week time point implants did not exhibited satisfactory integration with surrounding tissue, and most of the upper tissue was the type of hyaline-like cartilage. At 12-week time point, most of the upper tissues were hyaline-like cartilage, while lower parts were filled with bone, however not all of them showed good integration. Conclusions: The results of this work revealed osteochondral potential of autologous MPC in goat cartilage defect. It is clear, that further studies are needed to improve integration of scaffolds with surrounding tissue.