We attempted to characterise the biological quality and regenerative potential of chondrocytes in osteochondritis dissecans (OCD). Dissected fragments from ten patients with OCD of the knee (mean age 27.8 years (16 to 49)) were harvested at arthroscopy. A sample of cartilage from the intercondylar notch was taken from the same joint and from the notch of ten patients with a traumatic cartilage defect (mean age 31.6 years (19 to 52)). Chondrocytes were extracted and subsequently cultured. Collagen types 1, 2, and 10 mRNA were quantified by polymerase chain reaction. Compared with the notch chondrocytes, cells from the dissecate expressed similar levels of collagen types 1 and 2 mRNA. The level of collagen type 10 message was 50 times lower after cell culture, indicating a loss of hypertrophic cells or genes. The high viability, retained capacity to differentiate and metabolic activity of the extracted cells suggests preservation of the intrinsic repair capability of these dissecates. Molecular analysis indicated a phenotypic modulation of the expanded dissecate chondrocytes towards a normal phenotype. Our findings suggest that cartilage taken from the dissecate can be reasonably used as a cell source for chondrocyte implantation procedures.

Background: Lapidus (first metatarsocuneiform joint) arthrodesis is an established procedure for the management of hallux valgus. This study investigated the utility of fixation with a medial locking plate with adjunct compression screw versus fixation with two crossed screws.

Methods: Eight pairs of fresh-frozen human specimens were used in a matched paired test. Bone mineral density (BMD) was measured with peripheral quantitative computed tomography (pQCT). Fixation with two 4-mm-diameter crossed screws was compared versus a medial locking plate (X-Locking Plate 2.4/2.7; Synthes, Solothurn, Switzerland) with adjunct 4-mm-diameter compression screw. The specimens tested in a four-point bending test. Parameters obtained were initial stiffness; plantar joint-line gapping after one cycle, 100 and 1000 cycles; and number of cycles to failure. Failure was defined as ≥ 3 mm plantar gapping displacement.

Results: The groups did not differ significantly with regard to BMD (p = 0.866) and initial stiffness (p = 0.889). The plate-and-screw construct showed significantly less movement during testing, and significantly (p = 0.001) more cycles to failure than did the crossed-screw construct. There was a significant correlation (crossed-screw construct: p = 0.014; plate-and-screw construct: p = 0.010) between BMD and the number of cycles to failure.

Conclusions: Under cyclic loading conditions, the construct using a medial locking plate with adjunct compression screw was superior to the construct using two crossed screws.

Clinical Relevance: The medial locking-plate technique described holds promise for shortening the time off weight-bearing and for reducing the risk of non-union.

Introduction: The debridement of deep cartilage defects is one of the most frequently used Methods: in arthroscopic surgery.

This randomized study was undertaken to compare the effectiveness of simple mechanical debridement and the 52°C-controlled bipolar chondroplasty.

Materials and Methods: A total of 60 patients (28 male, 32 female, average age 43.3 years, range 20 to 50 years) who were suffering from a grade III cartilage defect of the medial femoral condyle were included. Exclusion criteria were revision arthroscopy, injury or osteoarthritis (grade II or higher).

After randomization, 30 patients underwent simple debridement of the cartilage defects, which was performed with a mechanical shaver (MSD = mechanical shaver debridement). The remaining patients underwent thermal chondroplasty, which was performed with a temperature-controlled bipolar device with a constant thermo-application of 51°C (RFC = Radio-Frequency-based Chondroplasty).

The patients were evaluated by the Knee-injury and Osteoarthritis Outcome Score (KOSS) preoperatively and at time of follow-up. Activity levels were measured by the Tegner score (activity level before onset of the symptoms and at time of follow-up). Follow-up was undertaken 4 years after the arthroscopy.

Results: No significant differences between the preoperative findings for the two groups were observed.

One patient from the MSD group had died, and one female patient in the RFC group was lost to follow-up. A total of 18 patients had undergone revision operations due to persistent knee problems: in the MSD group, there were 8 endoprostheses, 4 osteotomies, and 2 revision arthroscopies; in the RFC group there was 1 one replacement, 2 osteotomies, and 1 revision arthroscopy with subtotal medial meniscectomy. The proportion of revisions was significantly higher in the MSD group (p=0.006). These patients were excluded from the evaluation.

The remaining 40 patients from both groups benefited from the operation. The preoperative KOOS was 11.3 points in the MSD group and 15.5 points in the RFC group (p=0.279). Patients from the MSD group had a KOOS of 53.2 at the time of follow-up. In the RFC group the KOOS (71.8) was significantly higher (p< 0.001).

Patients from both groups had to accept a decrease in their level of physical activity. However, patients from the RFC group had a significantly improved (p=0.005) Tegner activity score in comparison to the patients from the MSP group.

The radiographic and MRI findings in the MSD group were also worse than in RFC patients.

Conclusion: RFC is a potential method for the treatment of deep cartilage defects. The 4-year outcome is better than after MSD. Long-term results are still lacking.