Summary
The HELICA-Endoprosthesis is a newly developed cementless hip prosthesis for dogs.
It was implanted in 39 dogs that had severe hip osteoarthritis and a history of hip
pain, as well as in one dog that had chronic hip luxation. One dog had a bilateral
arthroplasty. The body weight of the patients ranged between 22 and 54 kg and their
ages between nine months and 10 years. Both the femoral stem and acetabular component
of the prosthesis were screwed into position following bony preparation. Additional
fixation was not necessary as the components remain fixed in position until osteointegration
is complete. There are currently five sizes of prosthesis available, and the various
components such as the stem, cup and head are readily interchangeable. Although it
appeared that good osseous anchorage of the prostheses in the bone on the surgery
table had been obtained, three patients experienced both stem and cup loosening (one
week, three weeks and six months after surgery). In one animal, stem loosening was
observed six weeks after surgery, and another dog experienced a cup loosening two
weeks postoperatively. Most of the complications were due to technical errors that
occurred during the learning phase. Surgical revisions were successful in three out
of five animals. In two animals we had to perform a femoral head and neck excision.
Two other animals experienced radiographic bone resorption underneath the segmented
collar of the femoral prosthesis but did not show any significant clinical signs of
lameness. Another dog that showed signs of ischial neuropraxy after surgery, recovered
completely within six weeks after surgery. All of the dogs were capable of weight
bearing on the operated leg one day after surgery. The main advantage of the HELICA-Endoprosthesis
is the relatively easy surgical technique and short surgery time. The initial clinical
results in these 40 cases have been very encouraging. The aim of this study was to
assess the early clinical results in these 39 dogs. Final evaluation can only be based
on the results of gait analysis, long-term follow-up, and post mortem histological
analysis.
Keywords
Total hip arthroplasty - dog - cementless - HELICA-prosthesis