Aims: The role of unicompartmental knee arthroplasty (UKA) in the treatment of medial knee osteoarthritis (OA) is controversial. The purpose of the study was to analyse our mid-term results of our UKAs operated in 1991–94. Method: Patient þles, the special knee arthroplasty form and radiographs were used to retrospectively analyse the results of 155 UKAs in 142 patients operated for medial knee OA. Results: The mean age of the patients was 66,4 years (39–86), and 65,5% of the patients were women. Good pain relief was reached in all cases with an average ROM of 0–121 degrees at 3 months postoperatively. The operations were complicated by superþcial wound infection in three patients (2,1%), deep vein thrombosis in one patient (0,7%), and limited ROM in one patient (0,7%). The survival rate of UKA was 91,6% at 9,4 years. A total of 13 knees were revised with a total knee prosthesis. Polyethylene wear (n=9), disease progression (n=2), aseptic loosening (n=1) and fracture (n=1) were the indications for the revision. The postoperative period was uneventful in all patients, and mean ROM was 0–108 degrees at 3 months. Conclusion: In our experience, UKA is a procedure with rapid recovery, good knee motion and patient satisfaction for the carefully selected patients in the treatment of medial knee OA. Once failed, UKA is safely revised with a routine TKA

Aims: The aim of this study was to evaluate the use of external þxation in Collesñ fracture.Methods: The history of all patients with distal forearm fracture (n=257) treated in Kuopio University Hospital during the year 1992 were studied. Radiographs of patients over 15 years of age treated with external þxation were studied (n=31), but only Collesñ fractures with dorsal angle (n=20) were cross-examined with a control group of conservatively treated randomly selected patients with a similar fracture (n=17). Radial shortening, dorsal angle and radial inclination were measured from the radiographs. Results: 70% and 22% of the fractures were intra-articular in external þxation (EF) and control (C) groups, respectively. The studied parameters at baseline were only a little bit (NS) worse in the EF group than in the control group. After reduction, the loss of radial length and inclination were corrected signiþcantly better using EF than in conservative treatment group. However, only radial inclination was maintained signiþcantly better in EF group after the immobilisation period (5–7 wk). There were less complications and functional problems reported in the conservatively treated patients (8% of all cases) than in the patients treated with external þxation (23%). However, worsening in the anatomical reduction during conservative treatment was reported in 22–27% of all cases. Conclusions: Only loss of radial length and inclination can be reduced signiþcantly better with external þxation than using conservative treatment. There seems to be no reason to use external þxation to reduce dorsal angle only. External þxation leads more often to complications than conservative treatment.

Aims: The aim of this prospective study was to measure changes of bone mineral density (BMD) in the proximal tibia after cemented total knee arthroplasty (TKA) in osteoarthrotic knee joints. Methods: Sixty-nine patients were scanned by dual-energy x-ray absorptiometry (DXA) within a week postoperatively, at 3, 6 and 12 months follow-up. Results:Medial metaphyseal measurement region on interest (ROI) showed a signiþcant decrease in BMD values in preoperatively varus knees joints (p < 0.0005). In preoperatively valgus knees there was a slight non-signiþcant increase in BMD (p=0.184). At the baseline the medial ROI BMD differed from each other signiþcantly in these alignment groups (p= 0.023, independent samples T-test). Alignment correction in the both groups showed bone remodeling towards similar actual BMD values. Finally medial and lateral BMD values were also more similar suggesting that the bone became equally strong on both compartments of metaphysis. We could not trace the effect of increasing AKS score values to the bone remodeling. Conclusions: We suggest that loading effect on bone may be a major profound bone remodeling factor. Its clinical value can not be ignored nor determined by other changes in knee joint status and function. These results conþrm the clinical importance of recreating the proper valgus alignment of the knee joint in TKA operation, which offers possibly better proof for the longevity of the tibial component.

Aim of the study: The aim of the study was to register and þnd out the longterm femoral bone response after insertion of femoral stem with or with-out cement. Materials and methods: Seventeen patients (7 men, 10 women) underwent cemented and 22 patients (14 men, 8 women) uncemented total hip arthroplasty (THA). The mean age in the cemented group was 69 (58–74) years and in the uncemented group 58 (46–68) years. Femoral bone mineral density (BMD) was measured using Lunar DPX or Lunar DPX-IQ densitometry according to zones by Gruen (ROI 1–7). BMD measurements were made preoperatively, and postoperatively over four to 14 days, and at 3, 6, 12, 24, and 36 months after THA. Postoperative BMD changes were calculated using the immediate postoperative BMD value as a reference, the change being expressed as a percent. Results: Peri-prosthetic BMD decreased signiþcantly almost in all ROIs during the þrst three months after both cemented (5–18%) and uncemented (3–14%) THA (p-values < 0.05 to p< 0.001). At the end of the þrst year the most remarkable decrease in BMD was found in the calcar (zone 7) in both groups (cemented 25%; uncemented 23%). Low preoperative bone loss predicted higher periprosthetic bone loss in both groups. From one to three year only small changes in periprosthetic BMD were detected after THA. Conclusions: The present study suggests that postoperative bone loss is equal after uncemented and cemented THA. The bone loss is most pronounced during the þrst six months after THA and mainly associated in proximal femoral bone. After the phase of acute bone loss, further loss is minimal after uncomplicated THA, reßecting merely the normal aging of bone. Patients with poor bone quality at baseline are at higher risk to lose bone around the prosthesis after THA.

Aims: We tested the hypothesis whether vascular endothelial growth factor (VEGF-A) gene transfer is an appropriate way to enhance recruitment and activity of osteoblasts in vivo. Methods: We tested plasmid/ liposome and adenoviral gene transfer vectors in vitro and selected adenoviruses for in vivo experiments. Adenovirus vectors containing VEGF-A or lacZ genes (1.4x10¹⁰ pfu) were injected locally into right distal femurs of New Zealand White rabbits. Saline was injected into all contralateral distal femurs. One and three weeks after the gene transfers femurs were collected for analyzes. Trabecular bone hard tissue histo-morphometry was performed to analyze the effect of gene transfer on bone turnover. Results: X-Gal staining showed that up to twenty percent of the bone marrow cells were transfected. When compared to unilateral lacZ transfected trabecular bone at one week time point, VEGF-A bone had 8% less bone volume, 90% higher osteoblast number, 100% higher osteoblast surface, 125% higher osteoid volume and 70% less resorption surface. Corresponding parameters were 70% higher bone volume, 7% higher osteo-blast number, 30% higher osteoblast surface, 22% higher osteoid volume and 49% less resorption surface at week three. Conclusions: Our results suggest that adenovirus-mediated VEGF-A gene transfer induces bone formation via increasing osteoblast activity and maybe useful for the treatment of osteoporosis and other diseases that required efþcient osteogenic therapy.

Aims: The aims of this prospective study was to elucidate, how the high tibial opening wedge osteotomy (OW-HTO) corrected the varus angle of the lower extremity to the desired valgus angle in arthrotic knee joint, and what are the typical complications concerning this operation method. Methods: Twenty-one patients were operated on by using the operation technique (Puddu 1998) from September 1999 to August 2000. Results: The mean preoperative femoro-tibial varus-angle of the þrst 21 patients was 1.4. degrees, immediate postoperative valgus-angle was 7.1 degrees and at the latest follow-up, the valgus angle was 5.6 degrees, respectively.

In 16 of these 21 patients the healing was uneventful. Five patients sustained complications. Three patients had fracture of the opposite tibial lateral cortex peroperatively. Two of these fractures healed without complication. One of these patients needed total knee arthroplasty later on because of pseudoarthrosis and loss of OW-HTO correction angle at the osteotomy site. Two patients sustained peroperative þssural fracture up to the lateral tibial joint articulation surface. These fractures healed uneventfully. Conclusion: A group of young, active heavy patients sustaining varus gonarthro-sis are candidates for HTO. After promising results of these 21 OW-HTO operations, we have operated 34 more patients. Complication rate has dropped because of better operative experience. However, OW-HTO is a sensitive operation with itñs possible complications. In experienced hands it is reliable and good operation. Also we have to remember, that this operation allow patients to keep their own knee joint with itñs normal kinesiology.