Preservation Of Bone Stock Research Articles

Short-term efficacy of short stem ceramic-on-ceramic total hip arthroplasty for young and middle-aged patients of femoral head necrosis

Objective To evaluate the clinical effects and experiences of short stem ceramic-on-ceramic total hip arthroplasty in the treatment of young and middle-aged patients with femoral head necrosis.Methods From December 2009 to March 2011,40 patients with femoral head necrosis were treated primarily with short stem ceramic-on-ceramic hip arthroplasty (43 hips) through posterior-lateral or anterior-lateral approach.There were 23 males,17 females； with the mean age of 40.5 years (range,27-55 years).All cases were stage Ⅳ or more according Steinberg stage.The patients were followed up at the 3,6,12 months after operation,and then once each year.Standard X-ray films were taken at the follow-ups.Femoral prosthesis subsidence was assessed through X-ray films.Harris scores system and WOMAC Osteoarthritis Index were recorded before and after operation to evaluate clinical effects of surgery.Results Thirty-eight patients (41 hips) were followed up for 21-36 months,with an average of 31.3 months.The femoral stem subsided 0.68±2.90 mm at the last follow-up.After operation,hip pain of patients was relieved obviously.The Harris score improved from 38.7±12.1 (15-66) preoperatively to 95.2±4.49 (83-100) postoperatively,WOMAC Index from 66.7±12.0 (49-94) to 12.8±5.6 (0-24).During follow-up period,there was no serious complication such as femoral neck fracture,infection of wound,pulmonary embolism,et al.No dislocation,implant prosthesis failure and infection were observed.Conclusion The short stem hip arthroplasty preserves bone stock to a great extent.The short stem implant showed a good stability and osseous integration.The wear rate of ceramic-on-ceramic bearing surface is extremely low.Short stem hip arthroplasty plus ceramic-on-ceramic bearing surface might be a good option for the young and middle-aged patients with femoral head necrosis. Key words: Arthroplasty, replacement, hip; Femur head necrosis; Treatmemt outcome

Results of a stemless reverse shoulder prosthesis at more than 58 months mean without loosening

A stemless reverse shoulder prosthesis with humeral cup was developed to allow stemless press-fit fixation, to preserve bone stock. Our hypothesis was that a stemless reverse shoulder arthroplasty could produce the same functional results without compromising humeral fixation. This is a continuous, prospective, single-surgeon series including prostheses implanted from 2004 to 2009. Patients received pre- and postoperative clinical evaluation with measurement of joint mobility, the Oxford Shoulder score, and the Constant-Murley score by independent evaluators. Standard radiographs and computed tomographic arthrography were performed. Fifty-six implants were reviewed at a mean of 58 months (38-95). The Constant-Murley score improved from 29 to 62 points and the Oxford Shoulder score from 46 to 17 points. Active elevation in forward flexion improved from 79° to 140°. One intraoperative complication was recorded: a metaphyseal-diaphyseal humeral bone crack without consequence. One revision surgery due to early instability was performed using a conventional implant. No humeral loosening was observed. Five cases of scapular notching were reported. This is the first study reporting results with mid-term follow-up for a stemless reverse shoulder arthroplasty. The clinical results are comparable to conventional prostheses with stem. The absence of a humeral stem preserves bone stock for possible later revisions.

Glenoid implant orientation and cement failure in total shoulder arthroplasty: a finite element analysis

To minimize glenoid implant loosening in total shoulder arthroplasty (TSA), the ideal surgical procedure achieves correction to neutral version, complete implant-bone contact, and bone stock preservation. These goals, however, are not always achievable, and guidelines to prioritize their impact are not well established. The purpose of this study was to investigate how the degree of glenoid correction affects potential cement failure. Eight patient-specific computer models were created for 4 TSA scenarios with different permutations of retroversion correction and implant-bone contact. Two bone models were used: a homogeneous cortical bone model and a heterogeneous cortical-trabecular bone model. A 750-N load was simulated, and cement stress was calculated. The risk of cement mantle fracture was reported as the percentage of cement stress exceeding the material endurance limit. Orienting the glenoid implant in retroversion resulted in the highest risk of cement fracture in a homogeneous bone model (P < .05). In the heterogeneous bone model, complete correction resulted in the highest risk of failure (P = .0028). A positive correlation (ρ = 0.901) was found between the risk of cement failure and amount of exposed trabecular bone. Incorporating trabecular bone into the model changed the effect of implant orientation on cement failure. As exposed trabecular bone increased, the risk of cement fracture increased. This may be due to shifting the load-bearing support underneath the cement from cortical bone to trabecular bone.

Prosthetic hip revision: relationship between bone stock and quality of life in aseptic loosening of the femoral component

We evaluated the clinical and radiographic results in the medium and long term in patients undergoing revision surgery for aseptic loosening with different bone quality at the time of the operation. We investigated how different bone quality shapes for a good clinical result. A total of 33 patients who underwent revision surgery of the hip (for aseptic loosening of the stem) evaluated radiographically and clinically at 1,6,12 and 18 months. The evaluation of clinical status preoperatively and at the end of follow-up was be made as questionnaires SF-36, Harris Hip Score and WOMAC; radiographic assessment was made using the scale of Paprosky. The data thus obtained have been related to complications arising and the status of femoral bone-loss before the surgery time. The groups PI and PII (Paprosky) showed a high level of satisfaction with an average value of reference for the postoperative rated as excellent, the absence of complications and good functional recovery at the end of follow-up. The groups PIII and PIV showed increased incidence of complications and difficulties with rehabilitation clinics and SF-36 scores and HHS inferior to other classes. Our dates confirm that bone quality at the time of surgery affects the therapeutic target. All patients with good bone quality at the time of the revision surgery (groups PI and PII) showed a distinct advantage from surgical treatment. Revision surgery had not much effect in patients with high bone loss. Preservation of bone stock should be considered a good foundation for the success of a prosthetic reimplantation with better functional and radiographic out-come associated with greater satisfaction for the patient.

Hip Resurfacing Implants: A Literature Review and Our Experience

Hip resurfacing offers a suitable solution for young patients with high function demands and good bone quality affected by hip diseases. The bone stock preservation along with the restoration of the normal proximal femur anatomy, the lack of stressshielding and the resumption of sporting activity are proven advantages of hip resurfacing. However there are some disadvantages such as fracture of the femoral neck, onset of neck-narrowing and possible complications due to the metal-on-metal bearing: pseudotumors, peri-implant osteolysis and chronic elevation of metal ions serum levels. Recent data suggest that the ideal candidate for hip resurfacing is an active male, younger than 65 years old, suffering from primary or post-traumatic osteoarthritis with a femoral head diameter larger than 50/54 mm. Based on these selection criteria literature reports an implant survival similar to total hip replacement. Our experience confirms the low failure rate and the excellent functional outcomes, with stable metal ions serum levels over time in well-functioning implants. Proper surgical technique, correct patient selection together with the right choice of a well established prosthetic model are essential elements for the long-term success of these implants.

Result of extracorporeal irradiation and re-implantation for malignant bone tumors: A review of 30 patients

Extracorporeal irradiation and re-implantation (ECI) has been used as limb salvage surgery for musculoskeletal oncology patients. Biological reconstruction, no risk of disease transmission and immunological reaction, ready availability and preservation of bone stock are the major advantage of this surgical technique. This case series details the outcomes of ECI. In total, 30 patients (31 sites) were treated with ECI between 1996 and 2007. The mean survivor follow-up period was 47 months (at least 24 and up to 108). The results of ECI were judged in terms of recurrence and limb function. Surgical failure was defined as local recurrence and the need for amputation, and reoperation for any reasons. Functional status was assessed by three functional assessment systems: Mankin score, the Musculoskeletal Tumor Society score (MTSS) and the Toronto Extremity Salvage score (TESS). In all, 24 patients (80%) were alive and free from disease at last follow up. Operative failure occurred in two cases (7%) and the main complication was infection in three cases (10%). The mean values of the MTSS and the TESS were 82% (57-98%) and 81% (57-99.), respectively. Excellent or good results were achieved in 27 patients (90%) according to the Mankin score. Patients classified as stage IA and IIA, upper extremity and ECI-prosthesis composite, mostly demonstrated excellent results without any complications. Our results are encouraging in terms of the orthopedic and oncological outcomes. This indicates that ECI offers a good alternative method for reconstruction in limb salvage surgery.

Revision total hip replacement using the cement-in-cement technique for the acetabular component

The technique of femoral cement-in-cement revision is well established, but there are no previous series reporting its use on the acetabular side at the time of revision total hip replacement. We describe the technique and report the outcome of 60 consecutive acetabular cement-in-cement revisions in 59 patients at a mean follow-up of 8.5 years (5 to 12). All had a radiologically and clinically well-fixed acetabular cement mantle at the time of revision. During the follow-up 29 patients died, but no hips were lost to follow-up. The two most common indications for acetabular revision were recurrent dislocation (46, 77%) and to complement femoral revision (12, 20%). Of the 60 hips, there were two cases of aseptic loosening of the acetabular component (3.3%) requiring re-revision. No other hip was clinically or radiologically loose (96.7%) at the latest follow-up. One hip was re-revised for infection, four for recurrent dislocation and one for disarticulation of a constrained component. At five years the Kaplan-Meier survival rate was 100% for aseptic loosening and 92.2% (95% CI 84.8 to 99.6), with revision for any cause as the endpoint. These results support the use of cement-in-cement revision on the acetabular side in appropriate cases. Theoretical advantages include preservation of bone stock, reduced operating time, reduced risk of complications and durable fixation.

Proximal Femoral Replacement and Allograft Prosthesis Composite in the Treatment of Periprosthetic Fractures with Significant Proximal Bone Loss

Femoral bone loss due to periprosthetic fracture, a challenging problem in total hip arthroplasty (THA), is increasingly encountered due to a rise in the number of revision THAs performed. Allograft prosthesis composite (APC) and proximal femoral replacement (PFR) are two available options for management of patients with difficult type-B3 Vancouver periprosthetic fractures. The treatment algorithm for patients with these fractures has been extensively studied and is influenced by the age and activity level of the patient. APC is often preferred in young and active patients in an attempt to preserve bone stock while older and less active patients are considered candidates for PFR. In spite of the high rate of overall complications with these two procedures, reported survivorship is acceptable. Treating patients with these complicated fractures is fraught with complications and, even with successful treatment, the outcomes are not as promising as those associated with primary hip replacement. In this paper, we aimed to review available published reports about PFR and APC for treatment of periprosthetic fractures around THAs.

Simultaneous Bilateral Direct Anterior Total Hip Arthroplasty Utilizing a Modular Neck-Sparing Arthroplasty Femoral Stem - Case Report and Literature Review

Total hip arthroplasty for the management of bilateral hip osteoarthritis has been described in the literature since the 1970’s, utilizing either a simultaneous (single anesthetic) or staged (multiple anesthetics) technique. Utilization of a direct anterior approach to the hip joint allows for simultaneous bilateral total hip arthroplasty, without the need for re-positioning or re-draping the patient during the operation. The procedure is performed in a sequential fashion focused on a single side, with completion of the procedure before immediately proceeding to the contralateral side. The use of femoral-neck sparing arthroplasty design spans greater than 30 years,1 with a focus on preservation of proximal bone stock for younger, active patients who are undergoing arthroplasty at a young age and may need future revision surgery. Success rates reported by Dr. Pipino in his series included 97% satisfactory radiographic results, and an implant survival rate of almost 100% at 25 years. The modern, press-fit, modular neck-sparing arthroplasty design has been available in the United States and Australia for nearly 3 years, and enables the surgeon to perform intraoperative customization of the hip biomechanics for each case. Additionally, the standard 12/14mm trunnion allows the surgeon to choose the femoral head and bearing material, allowing options for metal on polyethylene, ceramic on ceramic, ceramic on poly, or ceramic on metal couples, in order to help avoid the use of metal on metal couples that have demonstrated higher complication rates in the recent literature.To the best of our knowledge, we present the world’s first case report of a simultaneous, bilateral, direct anterior total hip arthroplasty utilizing a modular neck-sparing arthroplasty femoral stem design.

The cementless Bicontact® stem in a prospective dual-energy X-ray absorptiometry study

The cementless Bicontact total hip arthroplasty (THA) system (AESCULAP AG, Tuttlingen, Germany) was introduced in 1986/1987 and has been in successful clinical use in an unaltered form up to today. Although good long-term results with the Bicontact stem have been published, it is questionable whether the implant provides the criteria for a state-of-the-art stem regarding proximal bone stock preservation. The purpose of the study was to monitor the periprosthetic bone mineral density (BMD) in a prospective two-year follow-up dual-energy X-ray absorptiometry (DEXA) study. After power analysis, a consecutive series of 25 patients with unilateral Bicontact stem implantation was examined clinically and underwent DEXA examinations. Scans of seven regions of interest were taken preoperatively and at one week, six months, and one and two years. One patient required stem revision due to a deep infection. The Harris Hip Score increased significantly by 44 points. The most significant bone loss was observed in the calcar region (R7) in the first six months (-19.2 %). It recovered in the following 18 months to -8.5 %. The BMD in the greater trochanter dropped significantly after six months and remained stable at this level. BMD exceeded baseline values in distal regions and even more in the lesser trochanter region after two years. We conclude that the Bicontact stem provides adequate proximal bone stock preservation. We observed some signs of stress shielding at the tip of the stem, which is inevitable to some degree in THA with cementless straight stems. However, in this prospective DEXA investigation, we showed that proximal off-loading does not occur after THA with the Bicontact system. Thus, we believe that this stem is still a state-of-the-art implant.

Precision of novel radiological methods in relation to resurfacing humeral head implants: assessment by radiostereometric analysis, DXA, and geometrical analysis

Resurfacing humeral head implants (RHHI) are used to preserve bone stock and restore normal anatomy in the osteoarthritic shoulder joint. The purpose of this study was: (1) to describe the use of novel radiological methods in relation to evaluation of RHHI; (2) to estimate the precision of these methods; and (3) to present preliminary clinical and radiological results at 6 months follow-up after Copeland and Global Cap RHHI. Twenty-one patients (10 females) at a mean age of 64 (39-82) years and with shoulder osteoarthritis were randomized to a Copeland (n = 11) or Global C.A.P (n = 10) RHHI. Migration of the RHHI was analyzed with radiostereometric analysis (RSA), and bone mineral density (BMD) was measured with dual energy X-ray absorptiometry (DXA). The length of gleno-humeral offset (LGHO) was measured on radiographs. The patients were followed clinically with questionnaires. Precision of the radiological methods was high for the LGHO and acceptable for RSA and for DXA. At 6 months, shoulder function had improved significantly for both RHHI groups. LGHO increased significantly for the Copeland RHHI and was slightly reduced for the Global C.A.P. RHHI. The implant migration and BMD change around the implant from baseline until 6 months follow-up was comparable for both RHHI. Radiostereometric analysis and DXA can be used for evaluation of RHHI, but expectedly with a lower precision as compared to standards of TKA or THA. Geometric analysis of the prosthetic shoulder is precise. We interpret that the early radiological and clinical results of the two RHHI are comparable.

Outcome of the dynamic helical hip screw system for intertrochanteric hip fractures in the elderly patients.

The dynamic helical hip system (DHHS; Synthes, Paoli, Pennsylvania) differs from the standard dynamic sliding hip screw (SHS) in that in preparing for its insertion, reaming of the femoral head is not performed, thereby preserving bone stock. It also requires less torque for insertion of the helical screw. The associated plate has locking options to allow locking screw fixation in the femoral shaft, thereby decreasing the chance of the plate pulling off. While biomechanical studies have shown improved resistance to cutout and increased rotational stability of the femoral head fragment when compared with traditional hip lag screws, there is limited information on clinical outcome of the implant available in the literature. We report a single surgeon series of 87 patients who were treated for their per-trochanteric hip fractures with this implant to evaluate their clinical outcome and compare it with a cohort of 344 patients who were treated with the standard SHS. All data were prospectively collected, most as part of a structured Geriatric Fracture Care Program. The 2 groups were similar demographically, and medically, with similar rates of in-hospital complications and implant failure. Failure in the DHHS group was attributable to use of the implant outside its indications and repeated fall of the patient. This limited case series showed that the DHHS outcomes are comparable with that of the SHS. Whether there is any benefit to its use will require larger, prospective randomized controlled trials.

Hip resurfacing in patients under thirty years old: an attractive option for young and active patients

Metal-on-metal hip resurfacing is offered as an alternative to traditional hip arthroplasty for young, active adults with advanced osteoarthritis. The concept of hip resurfacing is considered very attractive for this specific population (hard-on-hard bearing component with a large femoral head limiting the risk of dislocation, and allowing femoral bone stock preservation). A prospective clinical trial was designed to investigate the outcome of hip resurfacing in young patients (under 30 years old). We studied 24 hips in 22 patients. Mean age at operation was 24.9 years (range 17.1-29.9). No patient was lost to follow-up. There was no revision at average follow-up of 50.6 months (44-59). Mean UCLA activity score improved from 5.5 (1-9) pre-operatively to 7.6 (1-10) postoperatively (p < 0.001). Mean Harris hip score increased from 43.9 (19-67) to 89.3 (55-100) (p < 0.001). Radiological analysis discerned no osteolysis and no implant migration. The absence of short-term complications, such as mechanical failure or dislocation, is encouraging and leads us to think that mid-term results will be satisfactory. Moreover, the specific advantages of hip resurfacing (bone stock preservation, excellent stability, low risk of dislocation, large-diameter head) make the procedure a very attractive option for young subjects.

Influence of loading and activity on the primary stability of cementless tibial trays

Several potential advantages exist for cementless tibial fixation including preservation of bone stock and increased longevity of fixation. However, clinical results have been variable, with reports of extensive radiolucent lines, rapid early migration, and aseptic loosening. The primary stability of an implant depends on the micromotion of the bone-implant interface, which depends on the kinematics and kinetics of the replaced joint. Finite element analysis was used to examine the micromotion for different activities (walking, stair ascent, stair descent, stand-to-sit, and deep knee bend) for three commercially available tibial tray designs. Similar trends were observed for all three designs across the range of activities. Stair ascent and descent generated the highest micromotions, closely followed by level gait. Across these activities, the mean peak (maximum) micromotions measured across the entire resected surface ranged from 64 to 78 (186-239) µm for PFC Sigma, 61-72 (199-251) µm for LCS Complete Duofix, and 92-106 (229-264) µm for LCS Complete. The peak micromotions did not necessarily occur at the peak loads. For instance, the peak micromotions for level walking occurred when there were low axial forces, but moderate varus-valgus moments. This highlights the need to examine the whole gait cycle to properly determine the initial stability of tibial tray designs. By exploring a range of activities and interrogating the entire resected surface, it is possible to differentiate between the relative performance of different implant designs.

Development of a testing method for the determination of interfacial micromotions of short-stemmed hip endoprosthesis

Short-stemmed hip endoprosthesis were introduced into total hip arthroplasty some years ago. Due to the main advantages of these implants, such as preservation of the femoral bone stock, capability of minimal invasive surgery and possibly less stress shielding, these short implants are used in young and active patients to achieve better preconditions for revision surgery. Equal to standard hip stems a sufficient primary stability of these short implants is required to accomplish secondary stability and thereby good long term results. In order to investigate the influence of different operation techniques on the post-operative stability the present work presents the development of an experimental setup and measurement device to investigate interfacial micromotions between short-stemmed hip implant and surrounding bone.

Biomechanical Comparison of Anatomic Humeral Head Resurfacing and Hemiarthroplasty in Functional Glenohumeral Positions

Resurfacing of the humeral head has gained interest as an alternative to traditional hemiarthroplasty because it preserves bone stock and respects the native geometry of the glenohumeral articulation. The purpose of this study was to compare the biomechanics of the intact glenohumeral joint with those following humeral head resurfacing and following hemiarthroplasty. Seven fresh-frozen cadaveric shoulders were tested with the rotator cuff, pectoralis major, and latissimus dorsi musculature loaded with 20 N and the deltoid muscle loaded with 40 N in a custom shoulder testing system. Each specimen was tested in 20°, 40°, 60°, and 80° of vertical abduction. The articular surfaces of the humeral head and the glenoid were digitized to calculate the positions of the geometric center and apex of the humeral head relative to the geometric center of the glenoid at each testing position. The contact area and contact pressures were also measured with use of a Tekscan pressure sensor. The geometric center of the humeral head shifted by a mean (and standard error) of 2.2 ± 0.3 mm following humeral resurfacing and 4.7 ± 0.3 mm following hemiarthroplasty (p &lt; 0.0002). The apex of the humeral head was shifted superiorly at all abduction angles following hemiarthroplasty (p &lt; 0.03). Both humeral resurfacing and hemiarthroplasty decreased the glenohumeral contact area and increased the peak pressure. Resurfacing more closely restored the geometric center of the humeral head than hemiarthroplasty did, with less eccentric loading of the glenoid. Compared with hemiarthroplasty, humeral resurfacing may limit eccentric glenoid wear and permit better function because the glenohumeral joint biomechanics and the moment arms of the rotator cuff and the deltoid muscle are restored more closely to those of the intact condition.

Development of a femoral stem providing strong anchorage and facilitated removal

Prosthetic elements must be securely anchored to bone. Should revision surgery be necessary, preservation of bone stock is crucial. The goal of this study was to develop and assess a femoral stem combining secure anchorage and facilitated removal in a goat model. The development of the uncemented femoral stem was part of an innovation process to fulfill the combined requirements. The stem was designed with two longitudinal semicircular grooves to accommodate a drill bit to unanchor the stem. These grooves were interconnected by canals, each 1 mm in diameter. The surface was partly coated with hydroxyapatite (HA). The stems were inserted in the left hip of 35 goats. Perioperatively, the grooves were filled with autologous bone grafts, and standard cemented canine acetabular component and head were used. The pull-out force was measured six months postoperatively. Following randomization, 11 animals had the grooves of the stem drilled to remove anchoring tissue. Twelve animals were left undrilled (controls). There was a significant difference in mean pull-out force between the group that had been drilled (1526 N) compared with the controls (2033 N, p = 0.028). Most of the HA had been resorbed. The stems had a high retention force. The procedure for un-anchoring by drilling significantly reduced the pull-out force.

Anterior o Postero-Lateral Surgical Approach: Can we Identify Parameters for the Choice in Noncemented Hip Arthroplasty?

Anterior o Postero-Lateral Surgical Approach: Can we Identify Parameters for the Choice in Noncemented Hip Arthroplasty?

Is the increase in bone mineral density after hip resurfacing uniform across the femoral neck?

We admired the work of Willis-Owen and his colleagues on bone remodelling after hip resurfacing presented in their article “Bone mineral density in the femoral neck increases after hip resurfacing: a cohort with five-year follow-up” [1]. Hip resurfacing has evolved as an alternative to total hip arthroplasty in young adults and has shown promising short- and mid-term results when prudent selection criteria were adopted. It is supposed to simulate the normal hip biomechanics and physiological bone remodelling with preservation of the proximal femoral bone stock. The authors have demonstrated an increase in the bone mineral density (BMD) of the femoral neck after hip resurfacing at five years which resembles physiological remodelling. The whole femoral neck (R1) was analysed as one region and calculations were made. Several finite-element analyses and original articles of case series in the literature reveal that bone remodelling is not uniform across the entire femoral neck [2–4]. The superolateral area adjacent to the implant has evinced a relative stress shielding [2]. Albeit, the significance and implications of differential degrees of BMD of the femoral neck have not been well defined. All the studies available have shown their results of BMD at a maximum of two years. We feel that such a prime study with a unique follow up of five years should have thrown light on this differential density and drawn some conclusions. This would have evoked more interest and provided insight into the remodelling of the femoral neck after hip resurfacing. Although the surgical procedure was described, the cementing technique used was not explained in detail. Cementing of the implant guide pin has been shown to decrease the strains in the head and neck resulting in stress shielding [5]. The level of bonding of the stem may alter the loading pattern after resurfacing. The authors have not commented on femoral neck notching and narrowing in their cases at five years follow-up as these would have gained significance amidst the factors influential in the replication of normal physiological loading and long-term implant survival. Although the limitation of not being able to correlate the BMD changes with implant positioning was acknowledged, overall information about the BMD, implant positioning, and femoral neck notching as well narrowing would have made the article more edifying. Could Willis-Owen and his colleagues please comment?

Influence of Different DXA Acquisition Modes on Monitoring the Changes in Bone Mineral Density After Hip Resurfacing Arthroplasty

Dual-energy X-ray absorptiometry (DXA) is a technique enabling the measurement of bone mineral density (BMD) around prostheses after hip resurfacing arthroplasty (HRA). In this study, we evaluated the consistency of different DXA acquisition modes with 33 patients who had undergone HRA. Patients were scanned with DXA immediately after surgery and at 3-, 6-, and 12-mo time points. All the patients were scanned with dual femur and orthopedic hip acquisition modes and analyzed using 10-region ROI model. With both acquisition modes, a statistically significant decrease (p<0.05, Wilcoxon’s test) in BMD at 3mo was revealed in 3 ROIs, located to upper and lateral upper femur. Both acquisition modes detected similarly (p<0.01) preservation of the femoral bone stock within 12mo in all but 1 ROI. The applied acquisition protocols involved the use of different footplates for hip fixation. Because the differences between acquisition modes ranged between +1.6% and −7.1% and the reproducibility of BMD values can vary by as much as 28% due to hip rotation, it is proposed that both dual femur and orthopedic hip acquisition modes can be used to monitor the changes in BMD after HRA. However, the same hip rotation is recommended for all DXA measurements.