Comparison of the risk of ovarian malignancy algorithm and Copenhagen Index for the preoperative assessment of Japanese women with ovarian tumors.

OBJECTIVE: To compare the risk of ovarian malignancy algorithm (ROMA) and Copenhagen Index (CPH-I) in their ability to distinguish epithelial ovarian cancer (EOC) and malignant ovarian tumors (MLOT) from benign ovarian tumors (BeOT) in Japanese women. METHODS: Patients with pathologically diagnosed ovarian tumors were included in this study. The study validated the diagnostic performance of ROMA and CPH-I. RESULTS: Among the 463 Japanese women included in this study, 312 had BeOT, 99 had EOC, and 52 had other MLOT. The receiver-operator characteristic (ROC) area under the curve (AUCs) of ROMA (0.89) and CPH-I (0.89) for distinguishing EOC from BeOT were significantly higher than that of CA125 (0.82) (CA 125 vs. ROMA; p = 0.002, vs. CPH-I; p < 0.001). The ROC-AUCs of ROMA (0.82) and CPH-I (0.81) for distinguishing MLOT from BeOT were significantly higher than that of CA125 (0.75) (CA 125 vs. ROMA: p = 0.003, vs. CPH-I: p < 0.001). The sensitivity (SN)/specificity (SP) of ROMA and CPH-I for distinguishing EOC from BeOT at standard cut-off points were 69%/90%, and 69%/90%, respectively, those for distinguishing MLOT from BeOT were 54%/90%, and 55%/90%, respectively. CONCLUSION: ROMA and CPH-I performed comparably well and better than CA125 in distinguishing EOC from BeOT in Japanese women. ROMA and CHP-I should be used with caution in practical situations, where all histological possibilities for must be considered, because the SNs of ROMA and CPH-I were only 54% and 55%.

Comparison between single and double suture passing techniques in the suture bridge rotator cuff repair with a 2-mm tape: A simulation study using a three-dimensional finite element method.

BACKGROUND: Suture bridge repair has been widely used as one of the standard procedures in the arthroscopic rotator cuff repair. We compared the intratendinous stress distribution between single and double suture passing techniques in the suture bridge repair using a 2-mm tape and clarified the roles of tensioning in this procedure. METHODS: A board-like model of the supraspinatus tendon and humeral head was used in order to standardize conditions and exclude the influence of anatomical variations between individuals. Reattachment of the supraspinatus tendon to the bone was simulated using both single and double suture passing techniques for the suture bridge repair using a 2-mm tape. A tensile load was applied to the medial end of the tendon, and the stress distribution pattern was observed. Elastic analysis enabled comparison of the von Mises equivalent and maximum principal stresses between the single and double suture passing techniques. The tape configuration was subsequently translated 1 mm toward the insertion points of lateral anchors to simulate the tensioning maneuver. RESULTS: Although the distribution pattern of both the equivalent and the maximum principal stresses was similar for both models, areas with a high stress concentration were smaller in the single suture passing model than those in the double suture passing model. The equivalent stress concentrated within the tendon beneath the tapes as well as in the area between the crossing tapes and the lateral end of the tendon, whereas the maximum principal stress concentrated medial to the sites of suture penetration. CONCLUSIONS: Single suture passing technique can reduce the extent of intratendinous stress concentration compared with double suture passing technique, which might be beneficial to reduce the incidence of type 2 retear after suture bridge repair of rotator cuff tendon using a 2-mm tape.

Tight medial knot tying may increase retearing risk after transosseous equivalent repair of rotator cuff tendon.

BACKGROUND: Retearing mechanism after transosseous equivalent (TOE) rotator cuff repair has not been fully clarified yet. OBJECTIVE: The purposes of this study were to compare the stress distribution pattern in the tendon stump between knotted and knotless TOE repair and to investigate the role of suture tension applied during medial knot tying using a 3-dimensional finite element (3D-FE) method. METHODS: Both knotted and knotless TOE repairs were simulated on the 3D-FE human rotator cuff tear model. Elastic analysis was performed to compare the stress distribution pattern inside the tendon between the two models. The amount of compressive load applied to the medial-row sutures was then changed as 0, 20, 40, 60, 80, and 100 N in the knotted model. RESULTS: Knotted model demonstrated more distinct stress concentration inside the tendon around medial-row sutures than the knotless model. Mean von Mises equivalent stress in this area in the 0, 20, 40, 60, 80, and 100 N models was 0.26, 0.35, 0.50, 0.70, 1.11, and 1.14 MPa, respectively. CONCLUSIONS: In the knotted TOE repair, tight medial knot tying might cause a high stress concentration around medial knots, which may constitute one of the pathogenetic factors of postoperative retearing at this site.

Is the timing of surgery associated with avascular necrosis after unstable slipped capital femoral epiphysis? A multicenter study.

BACKGROUND: An unstable slipped capital femoral epiphysis (SCFE) is associated with a high rate of avascular necrosis (AVN). The etiology of AVN seems to be multifactorial, although it is not thoroughly known. The aims of our study were to determine the rate of AVN after an unstable SCFE and to investigate the risk factors for AVN, specifically evaluating the notion of an "unsafe window", during which medical interventions would increase the risk for AVN. METHODS: This retrospective multicenter study included 60 patients with an unstable SCFE diagnosed between 1985 and 2014. Timing of surgery was evaluated for three time periods, from acute onset of symptoms to surgery: period I, <24 h; period II, between 24 h and 7 days; and period III, >7 days. Multivariate logistic regression analysis was used to identify risk factors for AVN. RESULTS: Closed reduction and pinning was performed in 43 patients and in situ pinning in 17. Among these cases, 16 patients (27%) developed AVN. The rate of AVN was significantly higher in patients treated by closed reduction and pinning (15/43, 35%) than in those treated by in situ pinning (1/17, 5.9%) (p = 0.022). In patients treated by closed reduction and pinning, the incidence of AVN was 2/11 (18%) in period I, 10/13 (77%) in period II and 3/15 (20%) in period III, showing the significantly higher rate in period II (p = 0.002). The surgery provided in period II was identified as an independent risk factor for the development of AVN. CONCLUSIONS: Our rate of AVN was 27% using two classical treatment methods. Time-to-surgery, between 24 h and 7 days, was independently associated with AVN, supporting the possible existence of an "unsafe window" in patients with unstable SCFE treated by closed reduction and pinning.

Comparison of fixation properties between coil-type and screw-type anchors for rotator cuff repair: A virtual pullout testing using 3-dimensional finite element method.

BACKGROUND: Pullout of inserted anchor constitutes one of the pathomechanisms of re-tearing after rotator cuff repair. The purpose of the present study was to investigate the fixation properties of suture anchors using 3-dimensional finite element method. METHODS: The computer models of three types of anchors (TwinFix Ti, HEALICOIL PK and HEALICOIL RG) were inserted into the isotropic cube model that simulated cancellous bone. In the virtual pullout testing, a tensile load (500 N) along the long axis of the inserted anchor was applied to the site of suture thread attachment to simulate a traction force. The distribution of von Mises equivalent stress, the failure patterns of elements inside the cube and the anchor displacement were compared among the three anchors. RESULTS: In TwinFix Ti, the highest stress concentration was seen around the anchor threads close to the surface of the cube, which caused element failure at this site. On the other hand, both HEALICOIL PK and HEALICOIL RG demonstrated a high stress concentration as well as element failure around the anchor tip. Comparing the anchor displacement, HEALICOIL RG showed the smallest displacement among the three anchors. The tensile loads that required a 0.1-mm displacement for TwinFix Ti, HEALICOIL PK and HEALICOIL RG were 400 N, 370 N, and greater than 500 N, respectively. CONCLUSIONS: The bony structures close to the footprint surface may be damaged during surgery due to preparation for the bony bed as well as the insertion of anchors. Thus, we assumed that HEALICOIL RG represented the best initial fixation properties among the three anchors tested. Virtual pullout testing using 3-dimensional finite element method could reveal the detailed biomechanical characteristics of each suture anchor, which would be important for shoulder surgeons to improve the clinical outcomes of rotator cuff repair.

Medium-term result of Elite Plus hip arthroplasty: the second modular evolution of the original Charnley low-friction arthroplasty.

BACKGROUND: The Elite Plus total hip arthroplasty (THA) system was introduced as the second modular evolution of the original Charnley low-friction arthroplasty. However, the results of the Elite Plus THA are currently considered to be inconsistent. The aim of this study was to clarify the medium-term results and the factors affecting the results of Elite Plus THA. METHODS: The results of 97 Elite Plus THAs in 87 patients at 5 years or more postoperatively were reviewed. The patients' mean age was 65 years, and follow-up averaged 8.0 years. The Elite Plus stem was used in all hips, and three designs of socket, Hylamer Ogee in 40 hips, Wroblewski Offset Bore in 38, and Charnley Ogee in 19, were implanted. The survival rates with loosening and revision as endpoints were analyzed. To clarify the risk factors affecting the survival rates, Charnley's functional classification, Bombelli's classification, Crowe's classification, structural bone grafting of the acetabulum, cup design, stem position, and grading of the cement mantle were evaluated. CONCLUSIONS: The results of Elite Plus stem THA were excellent in the medium term. The cup design was a potential confounding factor for acetabular loosening, and the Hylamer Ogee socket was associated with a poor result.

Normal bone growth requires optimal estrogen levels: negative effects of both high and low dose estrogen on the number of growth plate chondrocytes.

Endochondral bone formation at epiphyseal growth plate consists of the synchronized processes of chondrogenesis and cartilage ossification. Estrogen, the major female sex hormone, plays an important role in this process, particularly during the pubertal growth spurt. However, its effects on the growth plate are not completely understood. The aims of this study were to clarify the effects of estrogen on the kinetics of chondrocytes in the growth plates of 10- to 25-week-old female rabbits by studying the effects of ovariectomy or high-dose administration of estrogen on the balance between cell proliferation and death. Forty-eight Japanese white rabbits were divided into three groups: sham operated, ovariectomized, or ovariectomized with subsequent weekly injection of high dose estrogen from 10 weeks. The chondrocyte kinetics was investigated by histomorphometry and immunohistochemistry, using antibodies for caspase-3, a marker of apoptosis, and for proliferating cell nuclear antigen. Both ovariectomized and estrogen-injected rabbits showed a declination of the chondrocyte number although the latter animals indicated a more dramatic effect. Estrogen-injected rabbits showed a decrease in the cell proliferating ability together with an increase in chondrocytes undergoing apoptosis while ovariectomy mainly reduced the cell proliferating ability. Given the known importance of estrogen for bone growth, one would expect that ovariectomy and high-dose administration of estrogen would have opposite effects. However, the present study indicated that both low and high concentration had a similar effect: a decrease in the chondrocyte number compared with control, suggesting that estrogen has to be maintained within a narrow range for optimal bone growth.

Estrogen deficiency leads to decrease in chondrocyte numbers in the rabbit growth plate.

BACKGROUND: In the pubertal growth plate, sex hormones play important roles in regulating the proliferation, differentiation, maturation, and programmed death of chondrocytes. Although many studies have been reported on the regulation of estrogen in long-bone growth, some of the mechanisms have remained unclear, including its role in cell kinetics in growth plate chondrocytes. The aim of this study was to clarify the effect of a deficiency of estrogen on growth plate chondrocytes. METHODS: We obtained growth plates of the femoral head from normal and ovariectomized Japanese white rabbits at 10, 15, 20, and 25 weeks of age. The effects of estrogen deficiency on the cell kinetics of growth plate chondrocytes were investigated immunohistochemically using antibodies for an apoptotic marker, caspase-3, and for proliferating cell nuclear antigen (PCNA). RESULTS: Both the length of the femur and the height of the growth plate in the ovariectomized rabbits tended to be larger than those in the normal rabbits. There were fewer chondrocytes in the ovariectomized rabbits than in the normal ones. Caspase-3-positive cells were detected mainly in the hypertrophic zone, whereas PCNA-positive cells were found in the proliferating to upper hypertrophic zones. The ovariectomized rabbits showed a higher caspase-3-positive rate at 20 weeks of age and a lower PCNA-positive ratio in all age groups than the normal rabbits. CONCLUSIONS: This study indicated that ovariectomy led to a decreased number of growth plate chondrocytes, which resulted from decreased cell-proliferating ability and probably acceleration of the number of chondrocytes undergoing apoptosis.

Radiologically and histologically mixed liposarcoma: a report of two biphasic cases.

We report two cases of liposarcomas showing biphasic patterns, radiologically and histologically. The first case was a 52-year-old man with a 17 x 12 cm intramuscular tumor in the right thigh. MR imaging revealed a mass composed of two components: a fat component and another soft tissue component. Histological diagnosis revealed mixed-type liposarcoma consisting of well-differentiated and myxoid liposarcoma. The second case was a 62-year-old man with a 22 x 15 cm intramuscular tumor in the left calf. MR imaging showed a mass composed of fat and non-fat components. The histological diagnosis was well-differentiated and pleomorphic liposarcoma.