Purpose: The aim of this study is the mid-term analysis of osteochondral autograft transplantation for the repair of focal femoral defects.

Methods: We present clinical data based on arthroscopic and MRI appearances of 18 patients, from 2 to 6 years postoperatively, which illustrate growing concern about the progressive deterioration of articular cartilage surrounding the OAT graft. It seems that the osteochondral autograft transfer (OAT) can restore the height and the shape of articulating surface in osteochondral defects with composite autologous material that contains hyaline articular cartilage and a firm carrier. However, limited availability of autologous osteochondral grafts, dead spaces between circular grafts, the lack of integration of donor and recipient hyaline cartilage, and different thickness and mechanical properties of donor and recipient hyaline cartilage are frequent sources of clinical concern.

Results: Typically, the OAT graft itself maintains its mechanical and histological integrity over the years, but surrounding articular cartilage continues to deteriorate, leading to a wide area of further chondral damage. Although this is difficult to understand and explain, it seems that the damage to articular cartilage surrounding the defect, and probably most importantly the lack of chondral integration, are the main reason for further chondral damage.

Conclusion: Adherence to clear indications, correction of concomitant pathology, precise surgical technique and realistic goals are most important when considering OAT surgery in symptomatic patients with femoral osteochondral lesions. Treatment of focal femoral chondral lesions in active individuals remains a significant challenge with many controversies remaining.

Aims: We present the results of the PFC Sigma knee replacement at a mean follow-up of 2.75 years (range: 1 to 6 years). Clinician and radiographic evaluation was carried out using the American Knee Society Clinical Rating and Radiographic Scoring Systems. Patient outcome was assessed using the Oxford-12 and SF-12 health-status questionnaires. Methods: A consecutive series of 293 Total Knee Replacements (TKR) in 247 patients was followed prospectively between September 1996 and September 2002. Our series included 138 females and 109 males with a mean age of 73.2 years. We operated on 214 patients with osteoarthritis, 20 with rheumatoid arthritis, 12 with post-traumatic arthritis and on one patient with erosive arthritis. The patella was resurfaced in 36 knees. 11 patients died during the follow-up period. Results: Subjective patient satisfaction score was based on improvement in pain and functional status. It was marked as excellent in 183 knees, good in 75, fair in 26 and poor in 9. Active extension lag improved from a mean of 8.5 to 3.3 degrees and flexion from 98.5 to 107.1 degrees. The mean Oxford-12 score improved from 44.17 to 24.68 and the SF-12 from 30.05 to 34.99. Radiolucent zones were observed around 2 tibial components. Post-operative complications included wound-healing problems in 25 patients, wound infection in 12, cardio-respiratory in 12, DVT in 11, non-fatal PE in 3, resolved CPN palsy in 3 and 1 death. Prosthesis complications included stiffness in 31, chronic pain in 18 (4 CRPS) and instability in 3 knees. 13 patients underwent MUA and 6 arthroscopic excision of intra-articular adhesions. 2 prosthetic infections were confirmed by bone-scan. Revision surgery was undertaken in 3 patients, 1 for established infection, 1 patella replacement and 1 tibial insert exchange. Conclusions: The early results of the PFC Sigma Knee Replacement show a high degree of patient satisfaction with a low rate of serious complications. Survivorship analysis will be undertaken in the future.

The purpose of this study was to analyse the effects of two different biomechanical configurations on the tensile properties of equine patellar tendons. The study looked at a comparison of straight untwisted patellar tendons and double stranded, twisted specimens. The aim was to attempt a more anatomical Anterior Cruciate Ligament configuration when performing reconstruction using the patellar tendon.

Thirty four specimens were harvested and each sample group consisted of a pair of equine ligaments taken from the same animal. The first of the pair served as an ‘untwisted, straight ligament’ control group and the second as the ‘twisted, double stranded test group’. The ligament dimensions were measured for each specimen and the specimen was mounted on an Instron Series 4411© tensile testing machine and tensile load was applied until failure.

Results showed a clearly statistically significant reduction in the tensile properties (p< 0.005) of the twisted double stranded specimens which was against our original hypothesis. The results indicated that the twisted double stranded ligaments had only 65% of the tensile strength of their untwisted counterparts. Similar reductions were demonstrated when calculating energy to yield point and load at zero point yield stress. The results also demonstrated a significant reduction in the stiffness (Young’s Modulus) between the two test configurations.

The application of a double stranded twist to the patellar tendon confers no advantage in terms of tensile property of the ligament. In fact the application of such a model may cause significant reduction in strength and stiffness of the construct which may lead to early failure of the ACL patellar tendon autograft.