Introduction: Osteochondral lesions of the talus (OCL III–IV°) need both extensive debridement for revitalisation and osteochondral reconstruction of the joint surface. This can be achieved by autologous cancellous bone-grafting and combination with a cell-free bioresorbable collagen-I/III scaffold. Our first results with this technique are presented.

Methods: 25 patients (13 female, 12 male, mean age 30.9 years) with 26 osteochondral lesions of the talus (OCL III–IV°, 15 right, 11 left, 24 medial, 2 lateral, 1 bilateral case) were treated by minimal-invasive debridement, autologous cancellous bone-grafting and application of a porcine collagen-I/III scaffold (ChondroGide^®) and evaluated prospectively by clinical scoring and MRI. The average follow-up was 23.2 (6–36) months. The mean defect size was 2.0 cm², the mean depth 0.7 cm. 14 defects have had at least one (1–3) operation on the defect before. By the use of a distractor a malleolar osteotomy could be avoided in all cases.

Results: The AOFAS-score increased from 67.4 ± 12.2 to 89.5 ± 7.4 points (p< 0.01, t-test). On a visual 10-point scale pain decreased significantly from 6.2 to 1.7 while subjective ankle function improved from a mean of 4.4 ± 1.9 to 7.2 ±1.5. The results were rated excellent in 10/26 cases (38.4%), good in 14/26 (53.8) and fair in 2/26 (7.8%) cases. MRI follow-ups showed a complete or nearly complete defect filling. In two ankles a second-look arthroscopy unveiled the defects filled completely by a regenerative tissue with a smooth surface and good bonding. Full-core biopsies showed a mixed, mostly fibrocartilagenous tissue.

Conclusion: By combination of cancellous bone-grafting with a cell-free collagen-I/III scaffold typical osteochondral lesions of the talus can be adressed effectively in a minimal-invasive one-step procedure. By utilizing mesenchymal stem cells (MSC) for an autogenous reparation process the use of expensive cultured chondrocytes is not necessary. The results concerning clinical functional improvement, pain reduction and patients’ satisfaction as well as defect filling in MRI are promising.

Background: During the past decade, there has been a resurgence of interest in hip resurfacing as a mode of treatment for the younger patient with hip disease since major disadvantages of previous resurfacing systems have been overcome. The purpose of the presented study was to clarify if an imageless navigation system will allow precise placement of the femoral component.

Methods: Between September 2004 and May 2006, 50 metal-on-metal surface arthroplasties each were performed either using an imageless navigation system or the conventional technique. The inclination and the axial alignment of the femoral component were determined by two independend examiners and compared to the values presented by the navigation system.

Results: In the preoperative x-rays a mean CCD-Angle of 129.2 degrees (Control group: 127.5°) was measured. The mean femoral shaft angle was 137.5 degrees (Control group 133°) postoperatively with a mean deviation of 2.1 degrees compared to the values shown by the system. In the computer assisted group the mean deviation from the ideal placement in the axial plane was 2.9 degrees compared to 4.8° when using the conventional technique.

Conclusion: The use of a navigation system was associated with only an average time loss of 7 minutes for surface data acquisition und mounting of the reference base. The computer assisted technique appears to be helpful to avoid notching during the femoral bone preparation and improve implant positioning which might improve durability.

on in vitro incubation of articular and epiphysial cartilage of the ulna of the domestic pig 70 to 80 per cent of [U-¹⁴C] glucose was metabolised to ¹⁴C-lactate, but cartilage of the epiphysial plate produced up to five times as much ¹⁴C-CO₂ as articular cartilage, and the specific radioactivity of ¹⁴C (or ³⁵S)-chondroitin 4 (6)-sulphate isolated from epiphysial cartilage (following ³⁵S-sulphate incorporation) was about twice as high as that of articular cartilage. Six weeks after an osteotomy on both sides of the proximal epiphysial plate of the left ulna, the glucose uptake, lactate production, and the specific radioactivity of the glycosaminoglycans displayed no significant differences when compared with those of the corresponding epiphysial plate of the control right ulna, whereas a 50 per cent increase in the oxidation of ¹⁴C-glucose to ¹⁴c-co₂ was observed.