Purpose: Hyaline cartilage lesion in a large weight bearing joint can lead, if not treated, to damage of the subchondral bone. Since cartilage tissue does not heal spontaneously, nor can it regenerate, joint functional restitution is based on temporary biological solutions. The only promising approach for recovering damaged joint and avoid its eventual deterioration is to restore the genuine surfacing of hyaline cartilage.

Methods: We have developed a novel primary chondrocytes culture based on a unique source of cartilage cells whereby a gradual collagenase separation yield a homogenous chondrocyte population, which unlike other cartilage source-derived cells preserve the capability of spontaneous differentiation into cartilage forming cells.

Results: Following a short period of intensive proliferation, the cells start to differentiate into polygonal shaped cells, expressing Cbfa1-the skeletal tissues specific transcription factor, type II collagen and cartilage proteoglycan; thus producing a genuine hyaline cartilage. The cultured chondrocytes also preserve their responsiveness toward local and systemic factors such as growth hormone, insulin, PTH and IGF1. Since, cartilage is an immuno-privileged tissue; non- autologous cartilage sources may also be successfully transplanted. We have shown that mourine and porcine-derived cells injected into rats afflicted (AIA) joints replenish the articular lesion with no signs of WBC infiltration. Since, prior to differentiation, these cells undergo an intensive proliferation phase they can also be transfected. We have also shown that osteoprotegerin (OPG)-firstly known for its activity as RANK ligand decoy receptor, has direct ameliorative effects on cartilage development. We have shown that OPG transfected chondrocytes preserve their typical morphological and functional features.

Conclusions: This model of primary chondrocyte culture, develop authentic resemblance to hyaline (surfacing) cartilage with similar physical and mechanical properties of the original tissue. These cells can be successfully transplanted into damaged joint of a foreign host. Hence, we propose that these primary spontaneously-differentiating chondrocytes, from non autologous source- can be suitable for replenishment of articular lesions as well as vehicle for local application of beneficial cytokines like OPG.

Introduction: The introduction of bioabsorbable materials has improved the ability to offer a simple, fast and friendly user solution, to specific meniscal tears. The technique of meniscal suture with bioabsorbable tacks is associated with lower morbidity and lower complication rate.

Methods: Between 1997 and 2004, 14 patients underwent arthroscopic all-inside meniscus repair. We used Biofix bioabsorbable tacks fixation technique. Fourteen patients were followed-up: 11 males and 3 females. Their mean age was ~23 years (range 16–34). Follow-up average ~35 (range 6–72) months. Sport injuries were the main cause of meniscal tears (60%). Other causes included: work accidents (20%) and military accidents (20%). All the tears were located in red-on-red and red-on-white area. The mean length of tear was 9.6 mm. we used in average 2.5 tacks per meniscus tear. Furthermore, 4 patients had an associated ACL tear.

Results: The evaluation was based on Lisholm score. The results were excellent in 10 patients (71%), good in 1 patient (7%), fair in 2 patients (15%) and poor in 1 patient (7%). One patient suffered from transitory tender point on the medial aspect due to a protruded tack. One patient needed a menisectomy due to unresolved symptoms. One patient underwent ACL reconstruction.

Conclusion: This technique is an easy and reproducible procedure as compared to the classical meniscal suture techniques. It seems to be of a lower complication rate and further studies are needed to establish any associated morbidity.

Purpose: Midterm follow up of complete knee dislocation and clinical outcome evaluation.

Materials and Methods: Between 1990–2004, we retrospectively reviewed the records of patients with complete knee dislocation. Eighteen patients, 19 knees were followed. Twelve males and 6 females. The average age at follow up was 40.7 years. Treatment consisted of primary knee stabilization with tutor cast in 10 knees and 9 by external fixation for 6 weeks. Following rehabilitation program, further surgical treatment was according to clinical relevancy. Functional and subjective evaluation was registered by the WOMAC questionnaire.

Results: Eleven were multiple trauma patients, involved in RTA, 2 had a crush injury, one patient involved in aviation accident had bilateral dislocation and 4 patients had low energy injury. Out of 7 patients, 8 knees had isolated dislocation. One died, 3 were not available for clinical follow up. Twelve patients returned the questionnaire. The average result of the WOMAC score was 46.5, range 7–91. Four knees presented advanced osteoarthritis with painful stiffness. Eight knees presented at the end of the follow up with instability as chief compliant. Five patients underwent later reconstructive procedures. One patient underwent knee arthrodesis.

Conclusion: In patients with knee dislocation, associated polytrauma should be regarded as a bed prognostic sign. The results suggest the need to revaluate the initial treatment strategy. The overall outcome shows that nearly all patients were able to perform daily activities, no patients in our study attempted any strenuous activity.

Purpose: The purpose of this paper is to evaluate the results of One or Two-Stage revision surgery, in the treatment of infected Total Knee Arthroplasty.

Materials and Methods: Between 1978 and 2003, 43 cases of infected TKA were operated. Forty-one cases were followed more than one year. Twenty two patients were males and 19 females. Average follow-up (F-U) time was 8 years (range 1–25). Nine were diagnosed during the first six months postop and 32 cases were late infections. All patients were given intravenous antibiotics for 6 weeks according to culture.

One stage procedure was performed in 20 patients with a painful knee without purulent discharge. Of them, 9 patients were infected with Staph Aureus (45%), 2 Enterococcus, 1 Strep Viridans, 1 Brucella. Seven were clinically infected without positive cultures (35%). Average age at revision was 75.6Y, with 1.9 co-morbidities. Average time interval between primary and revision was 45.6 months. Gallium bone scan was positive in 40%, WBC was above 11000 in 20%, increased ESR in 25% and CRP values above 3 mg/L in 80%. Intra-operative loosening was found in 60% of femoral and tibial components.

Two stage procedure was performed in 21 patients, when pus was present during the operation. Interposed cement impregnated with antibiotics was left between bone ends and at least six weeks of IV antibiotics were given. Average age at revision was 68Y,with 2 co-morbidities. Average time interval between primary and revision was 20 months. Positive Gallium bone scan was in 100%, WBC above 11000 in 80%, increased ESR in 80% and CRP values above 3 in 63%. Twelve patients were infected with Staph Aureus (60%), 4 Enterococcus, 1 Strep Haemolyticus, 1 Candida and 3 clinically infected cases without positive cultures (14%). Intraoperative loosening was found in 43% and 79% of femoral and tibial components, respectively.

Objective result was graded according to HSS score. The differences between ‘one-stage’ and ‘two stage’ groups were checked by t-test of variance.

Results: Twenty four patients out of 41 (60%) were available for F-U, 11 among One Stage group and 13 among Two Stage group. Eleven patients died and 6 were lost for F-U. Subjective satisfaction was reported by 80% of patients. Overall, HSS score increased from 48.3 preoperatively to 80 postoperatively, with 30% excellent result, 48% good, 13% fair and 9% poor.

For One Stage group, postoperative subjective satisfaction was reported by 78% of patients and HSS increased from 49.9 to 81.4. Average arc of motion was 93°. There were 4 patients with recurrent infection (20%), 2 of them were treated with antibiotics and 2 needed second revision (10%).

For Two Stage group, postoperative subjective satisfaction was reported by 82% of patients and HSS increased from 47.3 to 78.6. Average arc of motion was 85°. No re-infection was recorded in this group.

No significant difference between the two groups was found in relation to postoperative HSS score and arc of motion. However, remarkable difference is reported regarding reinfection rate.

Discussion and Conclusion: In this series with an average of 8 years follow-up, HSS score in revision of infected TKR is lower (30% excellent and 48% good) than expected result in primary TKR. The ‘Two-Stage’ procedure was more effective in our hands than ‘One-Stage’ as for eradication of infection in Total Knee Arthroplasty.