Changes in Bone Mineral Density of Both Proximal Femurs after Total Knee Arthroplasty

Abstract

BackgroundThis study investigated the effects of total knee arthroplasty (TKA) on bone mineral density (BMD) of the proximal femur in patients who underwent the procedure.MethodsForty-eight patients scheduled to undergo unilateral TKA because of primary knee osteoarthritis were included in this study, which was conducted at a medical center between October 2006 and October 2009. In these 48 patients, 96 hips were evaluated. Measurement of BMD was performed preoperatively and one month, three months, six months, and one year after unilateral TKA. Repeated measured analysis of variance and paired t-tests for comparison of two repeated samples were used to compare differences between time points (preoperation, one, three, six, and 12 months) and between the operative and nonoperative sides.ResultsPreoperatively, BMD of the femoral neck, trochanter, and total hip on the operative side were lower than on the nonoperative side; however, there was no statistical difference. BMD of both femoral neck areas was significantly lower than preoperative BMD at one month and three months after TKA. BMD of both trochanter areas was significantly lower than preoperative BMD at one month and three months after TKA. BMD of both total hips was significantly lower than preoperative BMD at three months after TKA. However, no statistical differences of changes in BMD were observed between the operative and nonoperative sides at each measurement time.ConclusionsAccording to our results, TKA was found to affect both proximal femurs during the acute period. However, TKA did not affect a change in BMD of the proximal femur during one year postoperative.

A Review on Bone Mineral Density Loss in Total Knee Replacements Leading to Increased Fracture Risk

“…This BMD loss is further supported by a study by Kim et al [ 56 ] who investigated 48 Korean patients (11 males, 37 females, mean age 63 years) post-TKR; they reported a significant decrease in BMD at the trochanters and femoral neck in the first 3 months post-surgery, followed by a recovery of the BMD losses to − 2.14% at 12 months. A similar trend is seen across the research by Ishii et al [ 55 ], Hopkins et al [ 45 ] and Petersen et al [ 59 ] who all reported a decrease in total hip BMD during the first 6 months post-operatively.…”

Periprosthetic Bone Mineral Density Changes after Cementless Total Knee Arthroplasty

“…The presence of good BMD around the knee is an important factor in the longevity of TKA, and previous studies have concentrated on preventing decreases in BMD and bone atrophy after TKA 15,17,18 . Bone atrophy around the components and stress shielding following TKA is often observed on radiograph.…”

Changes in Bone Mineral Density of the Proximal Femur and Contralateral Knee after Total Knee Arthroplasty: A 4-Year Follow-Up of 38 Patients

“…In theory, this functional improvement could also have a bone-preserving effect on the bone mineral density (BMD) of skeletal bones in TKA patients. However, several authors have raised concerns about the bone loss reported during the acute postoperative period after TKA in proximal femurs and the spine [2,3], as well as the contralateral knee [4]. Whether these changes are amended in the mid-to long-term is not clear due to a lack of BMD studies with a long enough follow-up period.…”

“…Low BMD and aging are inevitably associated with increased fracture risk [9,10]. Some studies have also reported ipsilateral femoral neck fracture as a rare complication of TKA [3]. While there has also been evidence presented against proximal femoral BMD loss within a 2-year follow-up period after TKA, as evaluated by dual energy X-ray absorptiometry (DEXA) [11], concern remains due to more recent studies having shown the opposite results [2,3].…”

“…Some studies have also reported ipsilateral femoral neck fracture as a rare complication of TKA [3]. While there has also been evidence presented against proximal femoral BMD loss within a 2-year follow-up period after TKA, as evaluated by dual energy X-ray absorptiometry (DEXA) [11], concern remains due to more recent studies having shown the opposite results [2,3]. The aim of our study was to explore the mid-term changes in BMD, and to determine whether the BMD of the contra-and ipsilateral (affected side) hips and the contralateral (non-operated side) knee is preserved or even increased after TKA.…”