Defects in articular cartilage are often repaired with fresh osteochondral grafts. While fresh allografts provide viable chondrocytes, logistic limitations require surgical implantation within seven days of graft harvest. Here, we provide information on cold preservation of whole intact osteochondral materials that retains cartilage cell viability and function, and histologic and biochemical integrity for 28days. Canine femoral condyles were obtained and stored at 4°C for 14,21 or 28days. At the end of the storage period, cartilage was assessed for cell viability, 35S uptake, proteoglycan content and histologic parameters. The most noticeable histologic change was reduced Safranin-0 near the cartilage surface with 14days of cold preservation, but had recovered with 21 and 28days. Cartilage thicknesses did not vary significantly. Cell viability was >%YO at 14days, 75-98% at 21 days and reduced to 65-90% at 28days. Cell function measures showed that the level of 35S04 incorporation was suppressed in samples stored at 4°C. However, no significant differences were seen among groups at 14,21 or 28days of cold preservation. This data has implications for tissue banking protocols for osteochondral allograft material obtained for transplantation suggesting that cold preserved allograft material be implanted within 28days.

Studies have shown that osteoarthritis (OA) is highly associated with obesity, and individuals clinically defined as obese (BMI > 30.0 kg/m2) are four times more likely to have knee OA over the general population. The purpose of this research was to examine if isolated weight loss improved knee symptoms in patients with osteoarthritis. Adult patients (n = 24; age 18–70; BMI > 35 kg/m2) with clinical and radiographic evidence of knee OA participated in a one-year trial in which WOMAC and KOOS surveys were administered at a presurgery baseline and six and twelve months postsurgery. Statistical analysis was performed using Student's t and Wilcoxon Signed Rank tests. Weight loss six and twelve months following bariatric surgery was statistically significant (P < 0.05) compared to presurgery measurements. All variables from both KOOS and WOMAC assessments were significantly improved (P < 0.05) when compared to baseline. Isolated weight loss occurring via bariatric surgery resulted in statistically significant improvement in patient's knee arthritis symptoms at both six and twelve months. Further research will need to be done to determine if symptom relief continues over time, and if the benefits are also applicable to individuals with symptomatic knee arthritis that are overweight but not obese.

Both mechanical and biological factors influence the high re-tear rate after rotator cuff repair. Mechanical factors have largely been addressed by the introduction of better implants and modification of suture configuration, but further improvements are needed to address the often poor tissue quality of the degenerated rotator cuff tendons. Current biological solutions provide only short-term reinforcement and have been associated with pseudo-infectious reactions. This pre-clinical animal study investigates the biological response to a novel polycarbonate polyurethane patch used for tissue augmentation in a rat rotator cuff repair model. Bilateral defects were created in the supraspinatus tendons of 12 Sprague Dawley rats. One side was repaired with a patch as a tissue augmentation device. The contralateral side acted as internal control without patch augmentation. After 6 weeks the tissues were harvested and underwent histologic and histomorphometric analyses. Histological evaluation demonstrated no inflammatory reaction; histomorphometry revealed tissue ingrowth of 79.9%. In conclusion, the polycarbonate polyurethane patch for tissue extension or augmentation in rotator cuff repair has demonstrated no inflammatory response and excellent tissue integration in a rat rotator cuff repair model.

Symptomatic full-thickness defects of articular cartilage are increasingly treated with osteochondral allografts. The present study focused on the viability of cells in cartilage that had been impact loaded by the instruments used in preparation of the cartilage for transplantation. Osteochondral plugs were removed and reimplanted using a plastic tamp device fi tted with a load cell. Plugs were examined at time 0 or after 48 hours or 7 days of tissue culture. During insertion, the force was 25Ϯ6 N and increased with time to a peak of 307Ϯ84 N. On average, 18 taps were necessary for the insertion of each plug, and the applied total impulse ranged from 5.7 to 17.8 N. Peak force and total impulse were highly correlated (R 2 =0.76, PϽ.001). Typically, a loading cycle lasted Ͻ10 milliseconds with peak loading rates up to 133Ϯ25 kN/s for each individual plug. The loading rate was dependent on the peak force, ie, the higher the applied load, the higher the rate. Cell death was 60% in the upper zone for all groups at all time points and lower (20%) for the middle and deep zones. Cell death appeared to be higher in all zones of the impacted group. Investigating the whole plug at time 0, cell viability was signifi cantly lower for the impacted plugs compared to control (dead: PϽ.02, living: P=.05). After 48 hours, as well as after 7 days, mean cell viability remained affected. These data suggest that the range of loading used in the manipulation of cartilage tissue in transplantation must be carefully considered if cell preservation is to be maintained.[J Knee Surg. 2007;20: 105-110.]