Synovial tissue examination by frozen section as an indicator of infection in hip and knee arthroplasty in community hospitals.

Twenty-five surgical synovial sections were examined in 18 consecutive patients undergoing revision hip or knee arthroplasty (9 hips and 9 knees). All cases were performed in either of two community hospitals, with frozen-section tissue examined by multiple general pathologists. By protocol, acute inflammation was defined as more than five neutrophils per 60x high-power fields on multiple areas. A positive culture was defined as-organism growth from any surgical specimen. In each case, three surgical cultures and three frozen-section specimens were harvested from the synovium at corresponding periprosthetic surgical sites before antibiotics were administered. The average age of the patients was 68 years (range 40-87 years). There were 11 positive surgical cultures, 9 with positive frozen sections of synovium for acute inflammation (sensitivity, 82%; 95% confidence interval, 78-100%). There were 14 negative cultures; 13 had negative surgical frozen sections (specificity, 93%; 95% confidence interval, 83-100%). The positive predictive value of the test was 82%. There was accurate correlation between frozen section and culture in 22 of 25 cases (88%). In this community hospital setting, frozen section examination of surgical synovial tissue proved to be a reasonably sensitive and specific predictor of deep infection in revision hip and knee arthroplasty.

Periosteal chondroma. A clinicopathologic study of 23 cases.

The periosteal chondroma (juxtacortical chondroma) is an unusual tumor which usually occurs on the surface of tubular bones in the metaphyseal area. In this study, we reviewed the clinicopathologic features of 22 patients representing 23 instances of periosteal chondroma and discuss the radiologic and histologic features necessary for accurate diagnosis. The characteristic radiologic appearance is of a single cartilaginous mass in the metaphyseal periosteum causing well-defined depression or "saucerization" of the adjacent cortex. The radiologic differential diagnoses include soft-tissue tumors compressing bone, fibrous cortical defect, and periosteal chondrosarcoma or osteosarcoma. Histologic features include lobules of hyaline cartilage with frequent areas of hypercellularity, binucleate chondrocytes, and focal mild cytologic atypia. The histologic features clearly identify the tumor as chondrogenic; however, familiarity with the x-rays may be necessary to recognize the tumor as benign.

Chemical and hematologic changes in stored CPDA-1 blood.

Blood was drawn from ten healthy volunteer donors into citrate-phosphate-dextrose adenine (CPDA-1) anticoagulant and placed on the quarantine shelf of the blood bank refrigerator. Plasma glucose, sodium, potassium, chloride, bicarbonate, glutamic-oxaloacetic transaminase, lactate dehydrogenase (LDH) and hemoglobin as well as white cell count, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, whole blood pH, lactate and ammonia were measured on all samples initially and at one, seven, 14, 21, 28, and 35 days of storage at 4 degrees C. Whole blood lactate was analyzed serially on five of the units. The most pronounced changes were seen for glucose, potassium, bicarbonate, lactate, LDH, ammonia, and hemoglobin. Plasma glucose and bicarbonate declined in concentration while potassium, lactate, LDH, ammonia, and hemoglobin rose with storage. As expected, these changes differed little from those found with steroid blood collected in acid-citrate-dextrose or citrate-phosphate-dextrose.