Henry A. Finn

Diagnostic strategy for bone and soft-tissue tumors.

The diagnostic strategy to be used for a bone tumor depends on the ability of the clinician to make an accurate differential diagnosis on the basis of clinical information and plain radiographs. The clinician must be able to classify the patient as having a non-progressive or a progressive primary benign bone tumor, a primary malignant bone tumor, or a metastatic bone tumor. Only after assignment to one of these four categories can an effective diagnostic strategy ensue. If the clinical and radiographic information favors a diagnosis of malignant or aggressive benign bone tumor, the clinician should refer the patient to an experienced orthopaedic oncologist without performing additional diagnostic tests or a biopsy. If a soft-tissue mass is 5 cm in diameter or larger on physical examination, and especially if it is deep to the fascia, the patient should also be referred to an orthopaedic oncologist, without additional evaluation or biopsy, because of the relatively high probability that the mass is malignant.

Medial Gastrocnemius Transposition Flap for the Treatment of Disruption of the Extensor Mechanism after Total Knee Arthroplasty

We describe a modified technique for the salvage of a total knee arthroplasty after disruption of the extensor mechanism. Between January and December 1992, seven patients had reconstruction of the extensor mechanism with use of a medial or an extended medial gastrocnemius flap. Six of the seven patients were followed for a mean of thirty-three months (range, twenty-six to forty-one months) and were evaluated both preoperatively and postoperatively with regard to the knee and functional scores of The Knee Society as well as the range of motion, extensor lag, walking status, and patellar height. The seventh patient was lost to follow-up six months postoperatively and was excluded from the analysis of the results. Preoperatively, the knee and functional scores were 16 ± 12.3 points and 12 ± 12.1 points (mean and standard deviation), respectively; the mean range of motion was 70 ± 44.0 degrees; and the mean extensor lag was 53 ± 33.4 degrees. Postoperatively, the mean knee and functional scores improved to 82 ± 12.4 points and 51 ± 23.0 points, respectively; the mean range of motion improved to 100 ± 21.8 degrees; and the mean extensor lag decreased to 24 ± 18.8 degrees. After the procedure, all patients who previously had been dependent on a walker were able to walk about the community with or without a cane, and those who had been dependent on a wheelchair were able to walk with the assistance of a walker. Patellar height was measured according to the method of Insall and Salvati for the four patients who had a patella. Preoperatively, the patellar heights were grossly abnormal; postoperatively, they more closely approached accepted normal values for three of the four patients. Reconstruction of a complicated rupture of the extensor mechanism with use of a medial gastrocnemius transposition flap after total knee arthroplasty is a reliable option for treatment.

Limb-salvage surgery in the treatment of osteosarcoma in skeletally immature individuals.

Sacrifice of major growth plates during resection and fixed-length reconstruction of a limb in a skeletally immature child with osteosarcoma may result in a significant limb-length inequality as growth progresses. A limb-length discrepancy in the humerus may cause minor cosmetic problems but does not generally result in a significant functional deficit. In the lower extremity, tumors about the knee, including the distal femur and proximal tibia, usually present the dilemma of whether limb salvage by arthrodesis, osteoarticular allograft, or endoprosthetic replacement would result in a significant limb-length inequality and whether amputation of the extremity is a preferable procedure. The techniques of rotationplasty and an expandable endoprosthesis have been successfully used for treating skeletally immature patients with osteosarcoma of the distal femur. With regard to survival and function, the results obtained with these innovative methods are favorable compared with those of a high above-knee amputation.

Tryptase Levels Are Not Increased during Vancomycin-induced Anaphylactoid Reactions

Background Anaphylaxis, mediated by immunoglobulin E, may be clinically indistinguishable but is mechanistically different than chemically mediated anaphylactoid reactions induced by drugs such as morphine, curare, and vancomycin. A test to distinguish anaphylactic from anaphylactoid reactions would clarify therapeutic and medicolegal issues. Tryptase levels identify anaphylactic reactions but have not been evaluated in vivo during anaphylactoid reactions. A prospective, randomized, double-blinded, placebo-controlled trial of antihistamine chemoprophylaxis for rapid vancomycin infusion was performed, and plasma tryptase was measured using a new immunoassay. Histamine release was established by measurement of plasma histamine and the ability of prophylactic H1 and H2 antagonists to prevent common histamine-associated side effects. Tryptase levels were compared with histamine levels and clinical symptoms. Methods Before elective arthroplasty, 40 patients received vancomycin infusion (1 g over 10 min) and pretreatment with either antihistamines (1 mg/kg diphenhydramine and 4 mg/kg cimetidine) or placebo. Changes in tryptase (at peak histamine and 10 min after vancomycin infusion), histamine levels, and histamine-mediated symptoms were assessed using Fishers exact test, the Students t test, or the paired t test, as appropriate. Logistic regression models were used to quantify the association of clinical symptoms with antihistamine treatment and serum levels. Results Plasma tryptase levels were unchanged (99% CI, -0.5 to 1.6) independent of increased histamine levels, antihistamine pretreatment, clinical symptoms, or all of these. Histamine levels >1 ng/ml were significantly associated with hypotension, moderate-to-severe rash, and stopped infusion. Antihistamine pretreatment significantly decreased the incidence and severity of the reactions. Conclusion Plasma tryptase levels were not significantly elevated in confirmed anaphylactoid reactions, so they can be used to distinguish chemical from immunologic reactions.

A comparison of the prognoses for deep and subcutaneous sarcomas of the extremities.

We evaluated 172 patients who had a soft-tissue sarcoma of the extremity in order to determine whether the prognosis for a subcutaneous sarcoma was better than that for a deep sarcoma. At a median of thirty-six months after the biopsy or definitive operation at our hospital, six of the fifty-two patients who had had a subcutaneous sarcoma had died and one had had a local recurrence; in contrast, forty of the 120 patients who had had a deep sarcoma had died and eight had had a local recurrence. Twenty-five (48 percent) of the subcutaneous sarcomas were malignant fibrous histiocytomas, and thirty-eight (73 percent) were small (five centimeters or less in the largest dimension). The three-year estimates of disease-free survival were 85 percent for the patients who had a subcutaneous sarcoma and 54 per cent for those who had a deep sarcoma (p = 0.002). Although the survival estimates remained significantly different when the groups were matched for histological diagnosis and for intracompartmental location (p = 0.0001 and 0.0006, respectively), they were not significantly different when the groups were matched for the size of the tumor (p = 0.42). A Cox proportional-hazards model confirmed that a tumor size of more than five centimeters and the histological grade are the most significant prognostic factors (p = 0.0007 and p = 0.004, respectively): a tumor size of more than five centimeters was associated with a relative risk of 3.5 (95 per cent confidence interval, 1.7 to 7.3), and a higher histological grade was associated with a relative risk of 4.0 (95 per cent confidence interval, 1.6 to 10.3). Subcutaneous location, when considered separately, was not a significant prognostic factor (p = 0.45). The data indicate that a tumor size of more than five centimeters is a more important prognostic indicator than histological diagnosis, depth, or intracompartmental location.

Antihistamine prophylaxis permits rapid vancomycin infusion

OBJECTIVE To determine whether pretreatment with intravenous antihistamines attenuates the symptoms of red-man syndrome associated with rapid vancomycin administration. DESIGN Prospective, randomized, double-blinded, placebo-controlled study of patients undergoing elective arthroplasty. SETTING Preoperative unit in a tertiary care center. PATIENTS Forty preoperative patients (American Society of Anesthesiologists status I-III, receiving vancomycin prophylaxis for elective prosthetic joint replacement or revision. INTERVENTIONS Elective orthopedic patients were randomly allocated to receive intravenous antihistamines (diphenhydramine, 1 mg/kg, and cimetidine, 4 mg/kg) or placebo before rapid vancomycin infusion (1 g over 10 mins). Hemodynamic measurements, symptoms of histamine release, and plasma histamine levels were obtained in each patient during vancomycin administration. Rapid vancomycin infusion was discontinued in cases of decreases in mean blood pressure of > or =20% or intolerable itching. MEASUREMENTS AND MAIN RESULTS Clinical symptomatology of red-man syndrome and histamine levels were assessed using Fishers exact test or Students t-test. Comparison of baseline and peak histamine levels for both the treated (mean +/- SD, 0.2 +/- 0.2 vs. 4.7 +/- 2.4 ng/mL; p < .0001) and placebo patients (mean +/-SD, 0.2 +/- 0.1 vs. 3.5 +/- 3.4 ng/mL; p = .0002) was statistically significant. Although there was a significant increase in plasma histamine levels during vancomycin infusion, it did not differ between the treatment groups. Only two (11%) of the treated patients developed hypotension, vs. 12 (63%) of the placebo patients (p = .002). Rash was partially attenuated. Twelve (63%) of the treated patients developed rash, compared with 19 (100%) of the placebo patients (p = .008). The rapid infusion was discontinued in two (11%) of the treated patients, compared with 11 (58%) of the placebo patients (p = .005). Four treated patients had no symptoms of histamine release. CONCLUSIONS Pretreatment with intravenous H1 and H2 antihistamines permitted rapid vancomycin administration in 89% of treated patients. Although protection was incomplete, rash did not predict a need to stop the rapid infusion of vancomycin in our patients.

Anesthesia in patients with sickle cell disease: a review of 112 cases.

EVERAL publications have appeared over S the years describing death of patients with sickle cell disease during or immediately following anesthesia.1-3 These reports implied that anesthesia was a serious hazard for such patients. On the other hand Brown,4 while drawing attention to the dangers of the blood disease, reported that he encountered no complications attributable to anesthesia in his series of 16 sickle cell anemia patients.

Cementless total hip arthroplasty in patients with steroid-induced avascular necrosis of the hip. A 62-month follow-up study.

Twenty cementless porous-coated primary total hip arthroplasties (THA) were performed on 15 patients, all of whom were diagnosed with steroid-induced avascular necrosis (AVN). The average age of the patients at the time of surgery was 45 years. Minimum follow-up period for all patients was 24 months (average follow-up period: 62 months). Patients were rated using the modified Harris hip score, as well as serial radiographs. The average hip score at follow-up examination was 88, with 17 of the 20 hips having good or excellent clinical results. No revisions of the prostheses were performed. Using radiographic criteria, 12 femoral components met the criteria for bone ingrowth, seven were considered stable with fibrous fixation, and one femoral component was loose. When good initial femoral component fit was achieved, bone ingrowth reliably followed. Three acetabular components showed migration on serial radiographs. A high rate of acetabular component wear and osteolysis was noted. Avascular necrosis has been shown to adversely affect the outcome of hip arthroplasty surgery. Previous studies of patients with advanced AVN undergoing cemented THA report a high incidence of component loosening. Literature on the results of cementless THA in this patient group is sparse. The study demonstrates encouraging clinical results for cementless THA in steroid-induced AVN. Reliable femoral component fixation occurred if a good initial component fit was achieved; however, long-term acetabular loosening and wear remain serious concerns.

The Effects of the Rotating-Hinge Total Knee Replacement on Gait and Stair Stepping

We studied 7 younger and 5 older patients who had rotating-hinge total knee replacements, 10 patients who had semiconstrained total knee replacements, and 8 younger and 11 older healthy control subjects to determine the effects of the rotating-hinge device on gait and stair stepping. The younger patients with the rotating-hinge device had few significant differences from the younger control subjects during gait or stair stepping. The older patients with the rotating-hinge device had several significant differences from both the older control subjects and subjects with the semiconstrained device during gait and stair stepping. Nevertheless, the proportions of older patients with the 2 devices who were able to perform the step-on activity for the highest step were the same.

Bone allografts are immunogenic and may preclude subsequent organ transplants.

The authors report a case of a 41-year-old woman with diabetes and chronic renal failure in whom antihuman leukocyte antigen antibodies developed after she received a frozen bone allograft that limited her access to organ donors. The patient had a chondrosarcoma of the right distal femur. A wide resection with segmental total knee arthroplasty was followed by a revision using a composite bone allograft prosthesis. After revision, broadly reactive lymphocytotoxic antibodies developed in the patient. The patients panel reactive antibody level rose from 28% to a peak of 70%. Panel reactive antibody expresses the percentage of a panel of human leukocyte antigen type T lymphocytes from 40 individuals (representative of all human leukocyte antigen Class I histocompatibility antigens) to which antihuman leukocyte antigen Class I lymphocytotoxic antibodies have developed in the recipient as measured by the antiglobulin crossmatch method. The specificity of the patients primary antibody is found in 45% of donors available in Illinois since 1988 (N = 1606). Because a positive crossmatch precludes kidney and pancreas transplantation, at least 45% of cadaver organ donors were excluded from use for this patient. This is an unusual case that focuses on the potential impact of bone allografts in patients who may need subsequent organ transplantation.