Use of Particulated Juvenile Articular Cartilage Allograft for Osteochondral Lesions of the Wrist.

BACKGROUND: Articular cartilage injuries are a common injury among young, active patients, and the most appropriate treatment for these injuries remains controversial. A promising new technology in the treatment of high-grade cartilage injuries is particulated juvenile articular cartilage (PJAC) allograft (DeNovo NT, Zimmer, Warsaw, Indiana). This has been shown to be successful in multiple joints including the knee, talus, and elbow. No studies or case reports exist in supporting or discouraging its use in injuries of the wrist, in specific, the scaphoid. METHODS: The use of PJAC allograft is described for the treatment of an active 21-year-old male with an Outerbridge Grade IV chondral lesion on the proximal pole of his right scaphoid and right distal radius scaphoid facet who had failed conservative management. The patient was followed clinically and radiographically for 21 months. RESULTS: The patient had return to full sport (jujutsu) and full range-of-motion, both of which represented an improvement from his preoperative exam. Radiographically, the chondral lucency seen had decreased in size and was almost completely absent on radiographs after 21 months. CONCLUSIONS: The results of this case suggest that PJAC can be used safely and effectively in the wrist thereby potentially broadening the indications for its use.

Noncardiac surgery brain injury: etiologic factors and prevention.

EXCERPT: During total joint arthroplasty, showers of bony spicules, marrow fat, and clot are carried by venous blood to the lungs, creating conditions not unlike those present in patients who have suffered traumatic long bone fractures. There is recent evidence that, like the fat embolism syndrome (FES), which often has a component of neurologic dysfunction, total joint arthroplasty and femoral nailing are associated with intraoperative brain embolization as determined by transcranial Doppler ultrasonography, and magnetic resonance brain imaging. Although there are good data demonstrating that intraoperative brain embolization occurs during total joint arthroplasties, the makeup and, even more importantly, the clinical significance of these emboli remain speculative. Brain microemboli resulting from cardiac surgery occur by the millions and may cause focal ischemia resulting in significant neurologic dysfunction. Our studies suggest that the major source of these microemboli is lipid droplets of the patient's fat that drip into the blood in the surgical field. This lipid-laden blood is aspirated and then returned to the patient via the cardiopulmonary bypass (CPB) apparatus. Our investigations have focused on the causes (microemboli), consequences (brain damage), and strategies for elimination of brain lipid microemboli resulting from salvaged blood collected during surgery.

Processing scavenged blood with a cell saver reduces cerebral lipid microembolization.

BACKGROUND: Microembolization during cardiopulmonary bypass (CPB) can be detected in the brain as lipid deposits that create small capillary and arteriolar dilations (SCADs) with ischemic injury and neuronal dysfunction. SCAD density is increased with the use of cardiotomy suction to scavenge shed blood. Our purpose was to determine whether various methods of processing shed blood during CPB decrease cerebral lipid microembolic burden. METHODS: After hypothermic CPB (70 minutes), brain tissue from two groups of mongrel dogs (28 to 35 kg) was examined for the presence of SCADs. In the arterial filter (AF) group (n = 12), shed blood was collected in a cardiotomy suction reservoir and reinfused through the arterial circuit. Three different arterial line filters (Pall LeukoGuard, Pall StatPrime, Bentley Duraflo) were used alone and in various combinations. In the cell saver (CS) group (n = 12), shed blood was collected in a cell saver with intermittent preocessing (Medtronic autoLog model) or a continuous-action cell saver (Fresenius Continuous Auto Transfusion System) and reinfused with and without leukocyte filtration through the CPB circuit. RESULTS: Mean SCAD density (SCAD/cm2) in the CS group was less than the AF group (11 +/- 3 vs 24 +/- 5, p = 0.02). There were no significant differences in SCAD density with leukocyte filtration or with the various arterial line filters. Mean SCAD density for the continuous-action cell saver was 8 +/- 2 versus 13 +/- 5 for the intermittent-action device. CONCLUSIONS: Use of a cell saver to scavenge shed blood during CPB decreases cerebral lipid microembolization.

Cardiotomy suction: a major source of brain lipid emboli during cardiopulmonary bypass.

BACKGROUND: Brain injury remains a significant problem in patients undergoing cardiac surgery assisted by cardiopulmonary bypass (CPB). Autopsy brain specimens of patients after cardiac operations with CPB reveal numerous acellular lipid deposits (10 to 70 microm) in the microvasculature. We hypothesize that these small capillary and arterial dilatations result from a diffuse inflammatory response to CPB or from emboli delivered by the bypass circuit. This study was undertaken to determine which aspect of CPB is most clearly associated with these dilatations. METHODS: Thirteen dogs were studied in four groups: group I (n = 3), right-heart CPB; group II (n = 2), lower-extremity CPB; group III (n = 3), hypothermic CPB; and group IV (n = 5), hypothermic CPB with cardiotomy suction. All dogs in all groups were maintained on CPB for 60 minutes and then euthanized. Brain specimens were harvested, fixed in ethanol, embedded in celloidin, and stained with the alkaline phosphate histochemical technique so that dilatations could be counted. RESULTS: All dogs completed the protocol. The mean density of dilatations per square centimeter for each group was as follows: group I, 1.77 +/- 0.77; group II, 4.17 +/- 1.65; group III, 4.54 +/- 1.69; and group IV, 46.5 +/- 14.5. In group IV (cardiotomy suction), dilatation density was significantly higher than in group III (hypothermic cardiopulmonary bypass) (p = 0.04) and all other groups (p = 0.04). CONCLUSIONS: Blood aspirated from the surgical field and subsequently reinfused into dogs undergoing CPB produces a greater density of small capillary and arterial dilatations than CPB without cardiotomy suction, presumably because of lipid microembolization.