The present investigation was undertaken to explore the possible association between lower limb torsional abnormalities and some disorders of the knee, such as patellofemoral malalignment and Osgood-Schlatter disease.

Four groups of patients were subjected to clinical, radiographic and CT evaluation: 20 male and 20 female asymptomatic subjects, 27 girls affected with patellofemoral malalignment and 21 boys affected with Osgood-Schlatter disease. With CT femoral anteversion, patellar congruence angle, patellar tilt angle, condylomalleolar angle, the distance between the anterior tibial tuberosity and the trochlear groove and external tibial rotation angle could be measured. Statistical analysis was carried out by ANOVA and Student’s t-test.

In the patellofemoral malalignment group, the femoral anteversion and rotation were significantly greater than in comparison the other symptomatic or control groups. In the Osgood-Schlatter group the condylomalleolar angle and tibial rotation angle were higher than in controls.

Several authors have demonstrated the influence of changes in the torsional alignment of the leg on the genesis of many disorders of the knee. The present CT study, employing a method that is the most accurate to measure lower limb rotation, documents a close association between patellofemoral malalignment and femoral rotation and between Osgood-Schlatter disease and increased external tibial torsion. These associations does not imply a cause-effect relationship; nevertheless, it is conceivable that these torsional abnormalities, probably in conjunction with other factors, can be predisposing mechanical factors for the onset of anterior knee pain related to patellofemoral malalignment or Osgood-Schlatter disease.

Aims: Tissue engineering is an increasingly popular method of addressing pathological disorders of cartilage. Recent studies have demonstrated the clinical efficacy of autologous chondrocytes implantation in cartilage defects, but there is little information on the use of a solid scaffold and on the composition of the repair tissue. The present study analysed the clinical outcome and the histological characteristics of membrane-seeded autologous chondrocyte implantation at 12–24 month after operation.

Materials and methods: Eleven patients (7 males and 4 females, mean age 37 years) suffering from cartilage lesions of the knee (10 cases) and the ankle (1 case), underwent autologous chondrocyte implantation procedure in which the expanded cells were seeded on type I/III collagen membrane before transplantation (MACI – Verigen, D). Clinical outcomes were assessed by ICRS evaluation package: revised IKDC form and Knee Osteoarthritis and Injury Outcome Score (KOOS). At least 12 months after implantation biopsy samples were arthroscopically obtained from 7 patients previous informed consent. The regenerated tissue were taken according to the ICRS standardized procedure. The specimens were stained with safranin-O and alcian blue, polyclonal antibodies anti S-100 protein and monoclonal antibodies anti chondroitin sulphate, anti-collagen type I and II. Moreover the number of cells/area was quantitatively assessed by histomorphometric method (Quantimet 500+). Ultrastructural analysis was also performed by transmission electron microscopy (TEM). The specimens were evaluated by the ICRS visual histological assessment scale.

Results: Improvement 12 months after operation was found subjectively (39.7 to 57.9) and in knee function levels. The International Knee Documentation Committee (IKDC) scores showed marked improvement at 12 months (87% A/B). 90% of biopsies showed: smooth articular surface (I:3), hyaline-like matrix cartilage (II:3), cell distribution (columnar-clusters III:2), predominantly viable cells (IV:3), normal subchondral bone (V:3), normal cartilage mineralization and tide-mark (VI:3). All sections were clearly stained with safranin-O and alcian blue. In all the specimens the cells revealed a strong immunoreaction for S-100 protein and showed a positive reaction for chondroitin-S and type II collagen. Type I collagen was immuno-detected in the more superficial layers of the biopsies. TEM analysis revealed a defined chondral cell phenotype within a chondroid matrix. Tissue heterogeneity and irregularities of the surface were observed in two cases.

Conclusions: Clinical improvement and hyaline-like appearance of the repair tissue indicate that membrane-seeded autologous chondrocyte implantation is an effective technique for the treatment of cartilage lesions.