## 4 Discussion  
To our knowledge, this is the first study in the literature to test and compare alternate and simvastatin in terms of early periprosthetic bone loss following cementless total hip arthroplasty. Despite other studies in the literature using a minimum of 6 months postoperatively for evaluation, we decided to perform the DEXA and serum marker examinations at one and two months postoperatively because the study aims to decide whether or not alendronate and simvastatin can prevent early periprosthetic bone loss. None of the patients were allowed full weight-bearing because this was the standard postoperative protocol used within the institution. Although numerous research articles showed that immediate full weight-bearing postoperatively is safe, there are many orthopedic surgeons who avoid full weight-bearing [10; 11; 12; 13]. Before we began the study, we asked 23 orthopedic surgeons in our region who perform a cementless total hip replacement, and only 13% (\(n=3\)) of them allowed immediate full weight-bearing postoperatively. In order to compare the same zones both preoperatively and postoperatively, we had to modify the technique described by [PERSON]. Therefore, we used a template of the femoral implant from the postoperative DEXA scan, and thus we could detect the same Gruen zones as the ones in the postoperative setting. The only exception is Gruen zone 4, which is located beneath the distal pole of the femoral implant. This zone was not possible for us to calculate because the standard preoperative DEXA scans did not extend distally enough to contain Gruen zone 4. The preoperative values of the DEXA scan, which show higher values in the Gruen zones 3 and 5, are similar to other results reported in the literature [14]. The periprosthetic bone loss postoperatively, as found in our studies, is also supported by other studies in the literature [14]. Alendronate administration limited the periprosthetic bone loss at one month postoperatively compared to the control group in all of the Gruen zones, but due to the limited number of patients, the only significant results were in zones 5 and 6. There is no previous study on the early rate of periprosthetic bone loss after alendronate administration. The earliest interval of DEXA examination after alendronate administrations in previous studies is 6 months; therefore, a comparison with our study's results cannot be performed [15; 16]. The explanation for a later DEXA scan is that previous studies focus on the risk of aseptic loosening, which is the late complication in the case of total hip arthroplasty, while our study focuses on early complications. On the other hand, simvastatin administration only limited the bone loss in zones 1, 2, 5, and 6, but the results did not prove to be statistically significant. Like in the case of alendronate, we did not find any previous research in the literature to study the simvastatin effect at one month postoperatively. At two months postoperatively, alendronate and simvastatin did not show to protect against the periprosthetic bone loss compared to the control group. Alendronate showed a better bone loss prevention compared to simvastatin in Gruen zones 6 and 7, which is the most important due to the presence of the calcar area and provides good implant stability. We do not have a clear explanation for these findings, and since no previous studies were found, we cannot compare our study to other results. Overall, at one month postoperatively, alendronate administration showed a 1.58% gain in bone mineral density, while simvastatin and the control group had a similar loss in bone mineral density (11.6% and 12.8%, respectively). This result shows that alendronate is better compared to simvastatin for the prevention of early bone loss postoperatively. The favorable effect of alendronate on periprosthetic bone loss is supported by other studies in the literature [15; 16; 17]. [PERSON] et al. showed an average of 17% increase in the BMD levels at one year at the level of the calcar are, compared to the control group [17].