Oertzenweg 19 b
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From 1993 to 1998 at the clinic and polyclinic for small domestic animals at the Free University Berlin 154 artificial hip joints, type Richards Canine II (company Theiss), have been implanted in 136 patients. Main indication was chronic hip pain due to osteoarthritic changes secondary to hip dysplasia (148/154 = 96,1%) whereas other degenerative or traumatic diseases of the hip joint were seldom. Within an observation period from one month to four years (01,6 years) 147 (95,5%) hip joints could clinically and/or radiologically be evaluated. Reports by the owners were also added to the clinical findings.During the follow-up examination period only 18 (14%) of 129 dogs with bilateral severe degenerative joint disease secondary to hip dysplasia had to be provided with an artificial hip joint on both sides due to reversion of lameness.There were 28 (18,2%) cases with complications after total hip replacement. Dislocations occured (n = 8) most frequently, followed by aseptic loosenings of the implants (n = 7) and infections (n = 5). By appropriate treatment good function could be restored in 16 (5 7,1 %) of these cases.In the last analysis, 89,8% (132/147) of the examined dogs were free of lameness on the operated limb, 6,8% (10/147) showed only occasional stiffness or temporarily lameness after long rest periods or exercise. 3,4% (5/147) were permanently lame.Radiographs of the pelvis (n = 154) immediately taken after the operation showed that 74% (n = 114) of the joint cavities presented a correct, 2,6% (n = 4) a dorsally open and 2 3,4% (n = 36) a ventrally open position in the sagittal plane. Regarding the misplaced joint cavities the risk of dislocation was increased. With 66,2% (n = 102) of the joint cavities a light retroversion was observed in the transverse plane. However, the extent of the retroversion or anteversion respectively did not seem to have any influence on other adiologically parameters or on the clinical result. 59,1% (n = 91) of the diaphyseal prosthesis were placed centrally. 31,8% (n = 49) of the stems were positioned in a varus and 9,1% (n = 14) in a valgus orientation. Although the central position of the diaphyseal prosthesis was not achieved in all cases, most of the dogs clinically remained without physical discomfort.Neither the position of the collar of the prosthesis, the escape of cement into the pelvis or the cement filling seemed to have any influence on the clinical development.Follow-up radiographs (n = 114) showed a radiolucent zone at the cement-bone interface around the acetabular component in 36% (n = 41) of the hips and around the femoral component in 36% (n = 41). The longer the observation period the higher the number of hips with radiological clarification lines and their width. Changes proved by radiological examinations did not inevitably result in clinical discomfort.