Archives of orthopaedic and trauma surgery
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Arch Orthop Trauma Surg · Jan 1999
Prophylaxis of secondary osteoarthrosis with spherical osteotomy in residual acetabular dysplasia. Analysis of predictive factors of success.
The aim of this study was to evaluate whether or not spherical acetabular osteotomy prevents progression of osteoarthrosis in hip joints with residual dysplasia and which radiological parameters can be used postoperatively as predictive factors concerning the outcome. Sixty-eight out of 78 joints were re-investigated with a mean follow-up of 11.2 years after the index operation. Twenty-three Wagner type 1 and 45 type II osteotomies were performed. ⋯ The weight-bearing zone of the acetabulum showed an acetabular index (AC) angle of 27 degrees preoperatively and 14 degrees postoperatively. Statistical analysis proved a significant correlation between the normal postoperative values of the acetabulum/femoral-head index of Heyman and Herndon and the absence of degenerative joint changes at follow-up. 73.5% of the hips had not markedly progressed to secondary osteoarthrosis, but 26.5% of joints had deteriorated: 7.4% of them due to perioperative complications and early postoperative trauma. In 8.8% (severe dysplasia) only partial reorientation was possible, which explains the progression of arthrosis, but 10.2% progressed despite sufficient correction.
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Arch Orthop Trauma Surg · Jan 1999
Shear strength of the cement metal interface--an experimental study.
The shear strength of the cement-metal interface using rods with different surface treatments and a clinical standardized cementing technique was studied. Under "dry" conditions, a low interface shear strength can be obtained with polished and smooth CoCrMo surfaces (peak-to-valley height Rt: 1 microm, average 0.2 MPa; 5 microm, 0.38 MPa). Grit-blasted and polymethylmethacrylate (PMMA)-precoated surfaces achieved higher values (PMMA precoat: average 5.16 MPa; CoCrMo peak-to-valley height Rt: 20 microm, average 8.61 MPa: 60 microm, average 7.8 MPa). ⋯ A microscopic analysis of cross-sections revealed gap formations at the cement-metal interface to varying degrees (1-16 microm). PMMA-precoated rods rarely showed any gap formation at all. The above-mentioned gap formation was seen independently of the porosity at the cement-metal interface and corresponds to the clinical and postmortem observed debonding of the interface.
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Arch Orthop Trauma Surg · Jan 1999
Comparative StudyRevascularization and new bone formation in heat-treated bone grafts.
Human imnmunodeficiency virus (HIV) infection is one of the possible serious complications associated with bone allografts. In order to prevent infection, grafted bone is sterilized by various treatments. Heat treatment has attracted attention as a simple and practical method. ⋯ The grafts heat-treated at 80 degrees C showed relatively good revascularization and new bone formation. However, the grafts heat-treated at 100 degrees C showed unsatisfactory revascularization and bone formation, less than 40% of control 8 weeks after grafting. Therefore, heat treatment at 60-80 degrees C does not seriously affect revascularization and new bone formation.