[Reconstruction of acetabular defect with wire mesh and impacted bone graft in cemented acetabular revision].

OBJECTIVE: To discuss the method of reconstruction of acetabular bone defect with wire mesh, impaction bone-grafting and a cemented cup in acetabular component revision. METHODS: 21 hips in 21 patients, aged 50.1 (31 - 64), 2 hips being of the acetabular defect type I B, 1 hip of type II A, 4 hips of type II B, and 14 hips of type III according to the American Academy of Orthopaedic Surgeons (AAOS) grading system underwent reconstruction with wire mesh, impacted bone grafts and cemented polyethylene acetabular component, and then were followed up for 47 months (36 - 60 months). RESULTS: The mean Harris hip score improved from the preoperative 55.7 points to 92.9 points at the last time of follow-up. Radiographic incorporation between host the bone and allograft was achieved 11.4 months after the operation on average. The mean change of inclination of acetabular components was 2.2 degrees , in which one acetabular component developed a change of 15.5 degrees . The inclination of acetabular components increased by 1.7 degrees on average 3 months after the operation and 2.0 degrees 6 months after the surgery. The acetabular cup migrated medially and superiorly by 3.93 mm and 4.41 mm respectively, peaking in the sixth month after the operation. One hip developed heterotopic ossification (Brooker grade I). One hip received repeat revision because of the aseptic loosening of the acetabular component 25 months after the revision surgery. CONCLUSION: The changes of the position of acetabular cup mainly occur within six months after the reconstruction of severe acetabular bone defect with wire mesh, impacted bone graft and cemented polyethylene acetabular component. To prevent the displacement of the acetabular cup, it is necessary to keep initial stability of the acetabular cups within six months after the index surgery.

Clinical prospect of applying the chemical bile duct embolization to achieve a chemical hepatectomy in the treatment of highly selected hepatolithiasis.

The high recurrence rate of hepatolithiasis, together with the high operative risk of hepatectomy for specifically located stones shows that an effective treatment for intrahepatic stones has not been settled upon. It is commonly accepted that a diseased biliary duct mucosa is a prerequisite for the development of intrahepatic stones, and that segmental biliary obstruction is able to induce hepatic atrophy, fibrosis, and "self-cut" the obstructed hepatic segment. Therefore, we previously put forward the hypothesis that performing deliberate chemical bile duct embolization (CBDE) to induce a segmental chemical hepatectomy might be the way of treating hepatolithiasis. In this study, we review the relative experimental basis for CBDE, preliminary report on its clinical use in 2 patients, and speculate on its future application. To completely embolize a diseased biliary duct, absolute ethanol or phenol is firstly used to ablate the biliary mucosa and eradicate biliary bacteria. Subsequently, cyanoacrylate or tissue adhesive glue is used to permanently fill the duct lumen, occupying the space where the stones would have formed. Our prior laboratory investigations and preliminary clinical treatments have confirmed that this combination of embolization agents could not only achieve the desired aim of preventing stone recurrence but could also lead to complete atrophy of the targeted hepatic segment, thereby achieving a chemical hepatectomy. In the future, CBDE is likely to help in resolving the problem of calculous recurrence and thereby reduce the incidence of surgical reintervention and endoscopic stone extractions, which are so frequently needed in patients with hepatolithiasis. Also chemical hepatectomy might provide a new less-invasive hepatectomy method, especially for the more difficult resections of the caudate or right posterior lobes.

Effectiveness of chemical biliary duct embolization for chemical hepatectomy.

BACKGROUND AND AIMS: The high recurrence of hepatolithiasis and high operative trauma of hepatectomy necessitate new therapeutic approaches. Thus, this study was designed to (i) investigate the effectiveness of chemical biliary duct embolization (CBDE) for chemical hepatectomy; and (ii) to determine the mechanism of CBDE. METHODS: The median biliary ducts in rats were injected with phenol or absolute ethanol alone, or in conjunction with cyanoacrylate. The effectiveness of CBDE for chemical hepatectomy was assessed by investigating histology, in situ hybridization for Fas and transforming growth factor (TGF)-beta1, immunohistochemistry for alpha-smooth muscle actin, and reverse transcription-polymerase chain reaction (RT-PCR) for procollagen I mRNA. RESULTS: Histologically, phenol or absolute ethanol plus cyanoacrylate could embolize the targeted bile duct and promote hepatic fibrosis and atrophy in the embolized lobe better than using phenol or ethanol alone. In addition, CBDE accelerated hepatocellular apoptosis via up-regulation of Fas, thereby resulting in the death of hepatocytes, which were replaced by proliferative bile ductules and collagen. Importantly, the hepatocytes disappeared completely in the periphery of the embolized lobe, thus achieving the desired effects of chemical hepatectomy. Further investigation indicated that CBDE initiated progressive fibrogenic processes of chemical hepatectomy via up-regulation of TGF-beta1, which greatly enhanced the synthesis of collagen. Indeed, higher levels of TGF-beta1 and procollagen I mRNA were observed in the phenol embolization group than in any other group. CONCLUSION: Chemical biliary duct embolization, especially using phenol plus cyanoacrylate, might achieve the effects of chemical hepatectomy.

A preliminary study of applying chemical biliary duct embolization to chemical hepatectomy in rats.

The high recurrence of hepatolithiasis, together with the high operative risk of hepatectomy for specially located stones, has not been settled effectively to date. Thus, this study was designed to investigate the feasibility of applying chemical biliary duct embolization (CBDE) to chemical hepatectomy in rats. As revealed in our results, the intrahepatic biliary ducts could be partially or completely occluded by both phenol and absolute ethanol. In addition, the embolization effect was greatly enhanced by further using cyanoacrylate. Also noteworthy is that CBDE resulted in massive death of hepatocytes, which were replaced by proliferated bile ductules and collagen. More importantly, the hepatocytes disappeared completely in the periphery of the embolized lobe where chemical hepatectomy was achieved. As for the comparison of embolic agents, the combination of phenol and cyanoacrylate exhibited even better fibrogenic effects than the combination of ethanol and cyanoacrylate. In conclusion, CBDE might be a promising approach for achieving the effects of chemical hepatectomy. The combination of phenol and cyanoacrylate potentially acted as a more effective agent for biliary duct embolization.

[Influence of dosage on cell biocompatibility of hydroxyapatite/tricalcium phosphate].

OBJECTIVE: To investigate the influence of different dose levels of hydroxyapatite/tricalcium phosphate (HA/TCP) on the proliferation and alkaline phosphatase (ALP) activity of rabbit osteoblasts. METHODS: Three different dose levels of HA/TCP (10%, 40%, 70%) were co-cultivated with rabbit osteoblasts respectively. The proliferation and ALP expression capacity of osteoblasts were examined with MTT method and enzyme histochemistry once every 24 hours until 5 days. Three control groups of other materials were treated and examined in the same way: rabbit osteoblasts as normal control; polyvinylchloride as positive control; titanium alloy as negative control. RESULTS: There was remarkable time-effect relationship in the proliferation of osteoblasts. Ten percent HA/TCP did not affect osteoblasts growth while 40% HA/TCP could slow the cell growth rate down though time-effect relationship still existed. The proliferation of osteoblasts stagnated when co-cultivated with 70% HA/TCP. On the other hand, 10% HA/TCP could cause reversible damage on ALP activity of osteoblasts, whereas when the dose was 40%, and the cultivation lasted 6 days the damage was irreversible. Three different dose levels of titanium alloy (10%, 40%, 70%) had no effect on the proliferation or ALP activity of osteoblasts. CONCLUSION: Dosage is an important factor affecting the biocompatibility evaluation of biomaterial. It suggests that dose choosing should be more specified upon each individual biomaterial. It also indicates that ALP may be a good supplementary index of the cell compatibility of material.