Abstract
Aim
The purpose of the study was to analyse short- and medium-term results of a modern cementless short stem design hip joint endoprosthesis together with different parameters (offset, CCD, leg length), radiological findings and scores.
Material and Methods
186 cases using a metaphyseal fixed short stem prosthesis (MiniHip, Corin) at two hospitals were included for clinical follow-up. 180 patients were available for clinical follow-up with standardized scores: Oxford-Hip Score (OHS), Hip Dysfunction an Osteoarthritis Outcome Score (HOOS) and EQ-5D – Score. The scores were caught preoperatively and postoperatively every year.
Further on we could do a prospective radiological study of 250 consecutive hips with degenerative hip osteoarthritis were included (246 patients). These patients were operated by five different surgeons at 4 different hospitals. Standardized X-rays were performed with the same technique pre- and postoperatively in all patients. Different anatomical parameters of the hip were documented by using the pre- and postoperative x-rays (Offset, CCD angle, length of leg).
The 250 patients included 129 female and 117 male. The average age of the patients was 59.7 years (range: 27–82 years).
The whole follow-up and all measurements were performed by an independent examiner.
Results
The Oxford Hip Score increased from a preoperative average of 17.63 to a postoperative average of 44.22 within the first year (180 hips). The postoperative average was 45.74 within the second (94 hips), and 46.20 within the third year (15 hips). The HOOS rose from a preoperative average of 29.91 to 96.20 (180 hips) within the first year. After two years the HOSS had an average of 94.30 (94 hips) and 95.72 (15 hips) after three years. The EQ-5D showed a postoperative average of 77.66 points for the 180 patients. At the time of the last follow-up two stems had aseptic loosening.
The Offset only changed +0.29 cm (SD: 0.45 cm) after surgery. We could document only a small decrease of −0.51° (SD: 4.10°) of the CCD angle. The length of leg increased on average of +0.09 cm (SD: 0.34 cm). We found no difference between the measurements of female and male patients.
Conclusion
Our results show, that we could reconstruct the individual geometry of the hip quite well by using the metaphysial short stem prosthesis. The tendency of an increasing CCD angle and a decrease of the offset seems not to be existent with the design of this kind of short stem prothesis.
