Carcinosarcoma of the parotid gland: an unusual case with large-cell neuroendocrine carcinoma and rhabdomyosarcoma.

We report a case of carcinosarcoma of the parotid gland in a 72-year-old Japanese man. The patient noticed a rapidly enlarging hard mass in the right parotid gland. He underwent radical parotidectomy with cervical lymph node dissection. The resected tumor measured 3.5 x 4.5 cm and histopathologically showed carcinomatous and sarcomatous components. The carcinomatous component consisted of large-cell neuroendocrine carcinoma (LCNEC), squamous cell carcinoma and adenocarcinoma not otherwise specified, while the sarcomatous component included spindle cell sarcoma not otherwise specified, so-called myxosarcoma and rhabdomyosarcoma. The LCNEC component was predominant within the whole tumor. The diagnoses of LCNEC and rhabdomyosarcoma were also confirmed immunohistochemically. With regard to histopathogenesis, based on the lack of histopathological evidence and antecedent history of pleomorphic adenoma, we considered the present case to be de novo, not expleomorphic adenoma.

Anisotropy of osteoporotic cancellous bone.

To investigate the mechanism underlying femoral neck fracture, it is necessary to determine the various mechanical properties, including the bone strength, of the primary compressive group. We investigated the mechanical anisotrophy of the primary compressive group by comparing differences in its mechanical properties, depending on the loading direction. Twenty-three femoral heads of 20 female and 3 male patients with femoral neck fracture were studied. The mean age of these patients was 79.9 years (range, 63-98 years). A total of 82 cubic specimens (6.5 mm in length) were obtained (one to six specimens from each femoral head). The specimens obtained from each femoral head were randomly assigned into two groups: parallel and perpendicular. The parallel group included 43 specimens, and the perpendicular group included 39 specimens. A compressive load was applied either parallel or perpendicular to the primary compressive group of the specimens in each respective group. Three parameters were obtained: compressive stiffness, maximum stress, and maximum energy. We calculated the regression of three parameters against the square of the apparent dry density. These mechanical properties were compared between the two groups by testing the difference of the slopes in two regression lines by using analyses of covariance, in which two main effects of group (nominal value) and the square of the apparent dry density (continuous value) and an interaction between two factors were modeled. Three parameters were significantly correlated with the square of the apparent dry density in both groups. In all three measurements, the difference of the slopes between two regression lines was significantly different. This means that all three measurements decreased in the parallel group more than in the perpendicular one, as apparent dry density decreased. We consider that the bone strength of the proximal femur decreases more when stress is applied in the longitudinal direction (as in walking) and less when stress is applied in the transverse direction (as in a fall) when bone density decreases.

Linear melorheostotic scleroderma with hypertrichosis.

On the basis of clinical features and histological findings, cutaneous manifestations of linear melorheostotic scleroderma are apparently derived from a localized proliferative disorder and are not secondary to bone changes. If the hypertrichosis has the same origin as the osteocutaneous changes, melorheostosis may represent a congenital disorder with both ectodermic and mesodermic components.

Effect of ACTH on renal excretion of purine bases in a patient with isolated ACTH deficiency.

We investigated the renal transport of purine bases (uric acid, hypoxanthine and xanthine) after rapid and continuous ACTH loading tests in a patient with isolated ACTH deficiency, a rare cause of secondary adrenocortical insufficiency. Plasma uric acid concentration and the urinary ratio of uric acid/creatinine did not change in the rapid ACTH test, which did not increase plasma cortisol concentration. In the continuous ACTH loading test, the plasma concentration of uric acid and oxypurines (hypoxanthine and xanthine) decreased, and the urinary excretion and fractional clearance of them increased as well as the plasma concentrations and urinary excretion of cortisol. These findings suggest that glucocorticoid directly affects the common renal transport pathway for uric acid, hypoxanthine, and xanthine.

Human xanthine dehydrogenase cDNA sequence and protein in an atypical case of type I xanthinuria in comparison with normal subjects.

To investigate the properties of xanthine dehydrogenase/xanthine oxidase (XDH/XO) deficiency in a patient with atypical type I xanthinuria, as indicated by oxypurine data, a cDNA sequence encoding XDH, XDH/XO immunoblot analysis and a competitive PCR assay were performed, and the results were compared with those of normal subjects. The xanthine dehydrogenase cDNA sequence of the patient was consistent with the controls, while immunologically reactive 150 kD XDH/XO protein was not present in the xanthinuric duodenal mucosa, unlike the control duodenal mucosa. In addition, a decrease in XDH/XO messenger RNA was found by competitive PCR. These results suggest that atypical type I xanthinuria is due to a decrease in messenger RNA of XDH/XO. Furthermore, it was considered that this decrease could explain the normal plasma level and near normal urinary excretion of hypoxanthine seen in this case of xanthinuria, though XDH/XO activity and protein were not detected spectrophotometrically and immunologically, respectively.

A case of classical xanthinuria (type 1) with diabetes mellitus and Hashimoto's thyroiditis.

In a 62-year-old woman with non-insulin-dependent diabetes mellitus and Hashimoto's thyroiditis, hypouricemia was detected by a routine examination. Her plasma uric acid level was markedly low and urinary excretion of uric acid was undetectable. The high plasma and urine levels of xanthine were observed, although those of hypoxanthine were within normal ranges at rest after an overnight fast. After taking diet, plasma concentration and urinary excretion of hypoxanthine were markedly increased together with those of xanthine. The xanthine oxidase activity of duodenal mucosa was below the limits of detection. Allopurinol was metabolized to oxypurinol and pyrazinamide to 5-hydroxypyrazinamide in spite of no activity of xanthine oxidase, suggesting that aldehyde oxidase converted allopurinol to oxypurinol and pyrazinamide to 5-hydroxypyrazinamide. Based on these findings, she was diagnosed as having a subtype of classical xanthinuria type 1 with the normal plasma concentration of hypoxanthine in fast.

A case of localized primary sclerosing cholangitis mimicking intrahepatic bile duct cancer.

A 75-year-old woman with chronic hepatitis was regularly followed-up in our hospital. A computed tomography (CT) scan revealed an obviously enlarged intrahepatic bile duct in the posterior branch of the left lateral segment. Percutaneous cholangiography revealed an enlarged posterior branch of the left lateral segment and a narrow stenotic region at the root of this branch. We diagnosed her as having intrahepatic bile duct cancer, and a left lateral segmentectomy of the liver was performed. However, microscopic examination of the resected specimens revealed peribiliary fibrosis in the stenotic bile duct and other areas of the intrahepatic bile duct with no malignant cells. Thus, the final diagnosis was made to be primary sclerosing cholangitis. We must consider primary sclerosing cholangitis in the differential diagnosis of localized stenosis of the intrahepatic bile duct.

The Bisurface total knee replacement: a unique design for flexion. Four-to-nine-year follow-up study.

BACKGROUND: The Bisurface knee prosthesis was designed in 1989 to improve knee flexion without affecting the durability of the prosthesis. The prosthesis has a unique ball-and-socket joint in the midposterior portion of the femoral and tibial components, which functions as a posterior stabilizing cam mechanism and causes femoral rollback. The femoral component was made of alumina ceramic. The purpose of this study was to review the clinical results of the first 223 arthroplasties performed with this prosthesis in order to assess whether this new implant had achieved its design objectives. METHODS: From December 1989 to May 1994, all patients who were scheduled for primary total knee arthroplasty were enrolled in a prospective study of the Bisurface knee. The patients were evaluated clinically according to The Hospital for Special Surgery knee-rating system and with a self-administered questionnaire, and they were evaluated radiographically according to the system of the Knee Society. Kaplan-Meier survivorship analysis was performed with revision of the knee or recommendation for revision as the end point. RESULTS: One hundred and sixty-six patients treated with a total of 223 consecutive primary total knee arthroplasties were enrolled in the study, and 182 knees were followed for 3.9 to 9.0 years (mean, 5.8 years). Preoperatively, the mean Hospital for Special Surgery knee score was 44.5 points. At the time of latest follow-up, the mean knee score was 86.3 points. The mean preoperative and postoperative ranges of flexion were 119 and 124 degrees, respectively. The patients, even those with a good preoperative range of motion, rarely lost deep flexion of the knee after the procedure. A revision operation was performed in eight knees (because of infection in five, instability in two, and breakage of the peg of the patellar component in one). Two knees had recurrent medial-lateral subluxations of the femorotibial articulation, which were treated nonoperatively. No prosthesis had loosened aseptically and no alumina ceramic femoral component had broken by the time of latest follow-up. The rate of survival of the implant was 94 percent (95 percent confidence interval, 90 to 98 percent) at six years. According to the patient questionnaires, 20 percent of the knees sometimes felt loose in daily living activities, which prompted us to improve the intrinsic stability of the prosthesis by improving the congruity of the ball-and-socket joint. CONCLUSIONS: Total knee arthroplasty with the Bisurface prosthesis resulted in an excellent range of motion and a high level of satisfaction with the operation; the durability of the prosthesis is promising.

Improved range of flexion after total knee arthroplasty. The total condylar knee versus the KU knee.

One objective of the modification of the total condylar knee is to increase the range of flexion without compromising the durability of the prosthesis. The KU knee prosthesis was designed to improve postoperative range of motion. This prosthesis has a unique ball-and-socket joint in the center of the posterior portion of the femorotibial articulation. A retrospective comparative study was undertaken to determine whether the KU knee prosthesis had achieved its design objectives. The study was based on the clinical observation of two populations: one (the TC group: 31 joints) with total condylar prostheses and the other (the KU group; 31 joints) with KU knee prostheses. At two years postoperatively, the mean postoperative range of flexion was 94 degrees (range: 60 degrees to 120 degrees) in the TC group and 120 degrees (range: 95 degrees to 150 degrees) in the KU group. The mean postoperative range of flexion was 24 degrees better in the KU group than in the TC group (p < 0.01). The mean functional score was 76 points (range: 61 to 86) in the TC group and 81 points (range: 56 to 92) in the KU group. There were no statistically significant difference in pain, walking ability, deformity, extension lag, and activities of daily living (ADL) score between the two groups. However, a statistically significant difference was detected in the range of motion (ROM) score (p < 0.01). No major complications occurred in either of the two groups. Although the follow-up period was not long enough, the KU knee was thought to be a promising modification of the total condylar knee prosthesis.

Glenohumeral osteoarthritis following a "color test" during rotator cuff repair. A case report and a review of the literature.

A case of glenohumeral osteoarthritis in a 35-year-old female following a color test during rotator cuff repair is described. The patients had a tear in the rotator cuff involving the supraspinatus muscle and rotator interval. A color test with a 0.4% aqueous solution of gentian violet was performed during the operation and the ruptured cuff was not tightly sutured. The patient developed glenohumeral osteoarthritis 25 months postoperatively. Plain film radiographs showed joint space narrowing and bone sclerosis of the humeral head, but there was no evidence of osteophytes. This pathology was thought to have been caused by the aqueous gentian violet solution.

Acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum.

We report a unique case of acute cholecystitis due to strangulation of a floating gallbladder by the lesser omentum, which could be detected by abdominal ultrasonography. We believe this case to be the first case of reported literatures in English.

Acetabular labral tear: arthroscopic diagnosis and treatment.

We reviewed the cases of 10 patients with acetabular labral tear diagnosed and treated arthroscopically. The posterior portion of the labrum had a tear lesion in 7 patients, the anterior portion in 4, and the superior portion in 1. A longitudinal tear was found in 8 patients, a degenerative tear in 1, and fibrillation in 1. Eight patients who were treated by arthroscopic partial limbectomy experienced prompt pain relief, and were free of symptoms at the latest follow-up. The remaining 2 patients were treated conservatively but their symptoms did not subside. The following three findings were highly indicative of a torn acetabular labrum in the current study: (1) Pain elicited by internal rotation with the joint flexed 90 degrees, (2)pain elicited by axial compression to the joint flexed 90 degrees and slightly adducted, and (3) tenderness posterior to the greater trochanter. These findings were positive in 7, 10, and 8 patients, respectively. To diagnose acetabular labral tear, these signs and arthroscopy are useful. Hip joint-Labral tear.

Arthroscopic resection of the shelf (mediopatellar plica) in the knee under local anesthesia in outpatient clinic.

Forty-two knees with symptomatic mediopatellar plicae (shelves) were managed using the operative method under local anesthesia. Of these, thirty-one knees had isolated mediopatellar plicae, and eleven had other associated intra-articular pathologic condition, such as meniscal tear, lateral patellar tracking, osteochondritis dissecans, and minor osteoarthritic changes. The clinical results were excellent or good in thirty-seven (88%) patients, fair in five patients after an average follow-up of twenty-five months. No case showed deterioration after surgery. Because there are no definitive criteria for the indication of shelf resection, arthroscopic resection of the shelf under local anesthesia is recommended if there is any possibility of it being the cause of knee pain.

A novel surgical procedure for osteonecrosis of the humeral head: reposition of the joint surface and bone engraftment.

A novel surgical procedure was performed on a 33-year-old woman with idiopathic osteonecrosis of the head of the left humerus. The operation involved repositioning of the joint cartilage and bone engraftment through her humeral head from under the greater tuberosity with shoulder arthroscopy. The patient wore an abduction brace for 8 weeks after the operation to hold the joint surface in its new position. This surgical procedure resulted in considerable improvement of the functional status of the shoulder by relieving pain and increasing range-of-motion. A preoperative radiograph showed stage IV osteonecrosis of the humeral head. However, at follow-up, repositioning of the joint surface and improvement of the necrotic bone were observed by radiography and magnetic resonance imaging.

Rupture of the labra acetabularis as a cause of hip pain detected arthroscopically, and partial limbectomy for successful pain relief.

We describe two patients who had pain of unknown cause in the right hip for many years. Plain roentgenograms results were normal, and arthrography did not reveal any abnormal findings. Because clinical examinations strongly suggested internal derangement of the hip, arthroscopies of the hips were performed. The labra acetabularis were observed to be ruptured at the posterior margin of the acetabulum. Partial limbectomies were performed by the posterior approach, and the patients showed marked decrease in hip pain postoperatively. This report shows that a solitary lesion of fibrocartilaginous tissue of the hip can cause hip pain. These conditions can be easily misdiagnosed as sciatica.

Biomechanical analysis of Perthes' disease using the finite element method: the role of swelling of articular cartilage.

Radiologically, widening of the joint space in the hip affected with Perthes' disease is encountered in the very early stage of the disease when no changes are yet noted in the bone. This suggests that swelling of the articular cartilage may be taking place in the affected joint. Since the intra-articular volume of a ball-and-socket joint with a deep fossa, such as the hip joint, cannot be readily altered, this swelling is expected to exert a marked imbibitional pressure within the bone of the femoral head. We speculated that this biomechanical factor might play an important role in the development of Perthes' disease. A two-dimensional finite-element model with 853 elements was constructed to simulate the hip joint of a child. Stress distribution in epiphyseal bone of the femoral head was computed under the condition of swelling of articular cartilage, and biomechanical effects of the imbibitional pressure on the epiphysis were investigated. On the assumption that high stress concentrated in the bone caused collapse and necrosis, the process of development of Perthes' disease was simulated. The results of simulation using theoretical values were in close agreement with such clinical findings as destruction of the lateral portion of the epiphysis in the early stage, final fragmentation of the epiphyseal bone, and metaphyseal bone destruction.

Scintigraphy in nontraumatic femoral head necrosis.

We performed serial 99mTc-MDP bone scintigraphy of nontraumatic femoral head necrosis in 14 hips of 10 patients. The uptake of isotope was decreased in the very early stage, and either variable or increased at the stage when symptoms appeared. A variable uptake changed to increased uptake in 3 of 10 patients, but there was no hip in which an increased uptake changed to a variable uptake. No relationship was demonstrated between the scintigraphic appearance of the femoral head and the pain and function of the hip.

Biomechanical aspects of the development of aseptic necrosis of the femoral head.

With the advancement of computer technology it has been possible to determine stress distribution in bone by the finite-element method (FEM), for a pathomechanical analysis of aseptic necrosis of the femoral head. Development of aseptic necrosis of the femoral head has been considered to be coincident with ischemic changes in the bone. However, the area of necrosis in the femoral head does not correspond to vascular distribution. We speculated that not only biological, but also biomechanical factors might play an important role in the development of femoral head necrosis. A two-dimensional finite-element model, with 801 elements and 454 nodes, was constructed to mimic the hip joint. Conditions for the disease were simulated on the assumption that concentrated areas of high stress cause changes in the biomechanical properties of bone, according to Wolff's law, such as necrosis or sclerosis. Results of the simulation correlated well with clinical findings. Biomechanical factors should be considered, not only to prevent the collapse of bone structure but also to limit the spread of bone necrosis in the early phase of the disease.

Five-year results of bipolar arthroplasty with bone grafts and reamed acetabula for osteoarthritis in young adults.

Bateman universal proximal femoral arthroplasty combined with acetabular reaming was performed in 35 cases of osteoarthritis of the hip joint. The patients were from 21 to 59 years of age (average, 41 years of age) at the time of operation. The postoperative outcome for a middle term ranging from two to eight years, with an average of five years and nine months, was studied along with postoperative migration of the outer head. The clinical outcome, assessed by the evaluation criteria for hip function proposed by the Japanese Orthopaedic Association, was favorable. A stable average score of greater than 80 occurred for eight years postoperatively; the average preoperative score was 45. Of the 35 cases, seven cases (20%) had an upward migration of the outer head, and one case (2.9%) had an inward migration of 5 mm or more, but the migration did not affect the clinical outcome in any case. There was no certain relationship between the degree of rotation of the outer head and the extent of its migration. Migration of the outer head was prevented by postoperative exercise, in which total loading was initiated after the completion of the radiolucent zone around the outer head and its circumferential zone of osteosclerosis.