Efficacy of Bisphosphonates in Total Hip Arthroplasty Patients: Systematic Review and Meta-Analysis.

The scientific literature suggests that, if periprosthetic osteolysis (PPO) is not treated, it may have a negative impact on the results of a total hip replacement and possibly result in failure. This systematic review aimed to determine the efficacy of using bisphosphonates preventatively to limit PPO after a total hip arthroplasty (THA). METHODS: A systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A PICOS template was developed to ensure a structured approach. A search for relevant studies was performed across four databases, including Pubmed, Scopus, Embase, and Cochrane. They were all last searched on March 1st and were assessed using the Cochrane risk of bias tool for randomised studies. RESULTS: The final analysis included seven studies with a total of 126 study group participants and 144 control group participants. The studies looked at Bony Mass Density in terms of bone loss on Gruen's femoral zones after THA in a bisphosphonate (treatment) and control group (placebo/no treatment). The analysis revealed a statistically significant difference (p < 0.05) in favour of the bisphosphonate group in many of the included studies at 6, 12, and 24 postoperative months. CONCLUSIONS: This systematic review and meta-analysis, using the most recent applicable studies, showed the efficacy of bisphosphonates in limiting periprosthetic osteolysis after THA in a period between 6 and 24 postoperative months. Future studies should focus increasing group sizes and collecting results beyond the 2-year mark.

Finite element analysis of mechanical stress in a cementless tapered-wedge short stem in the varus position.

BACKGROUND: In recent years, the use of tapered-wedge short stems has increased due to their ability to preserve bones and tendons. Surgical techniques occasionally result in a varus position of the stem, which is particularly pronounced in short stems. Although the varus position is not clinically problematic, there are reports of an increased incidence of stress shielding and cortical hypertrophy. Thus, we evaluated and examined the acceptable range of varus angles using finite element analysis. METHODS: Patients diagnosed with osteoarthritis of the hip joint who had undergone arthroplasty were selected and classified into three types [champagne-flute (type A), intermediate (type B), and stovepipe (type C)]. Finite element analysis was performed using Mechanical Finder. The model was created using a Taperloc microplasty stem with the varus angle increased by 1° from 0° to 5° from the bone axis and classified into seven zones based on Gruen's zone classification under loading conditions in a one-leg standing position. The volume of interest was set, the mean equivalent stress for each zone was calculated. RESULTS: A significant decrease in stress was observed in zone 2, and increased stress was observed in zones 3 and 4, suggesting the emergence of a distal periosteal reaction, similar to the results of previous studies. In zone 2, there was a significant decrease in stress in all groups at a varus angle ≥ 3°. In zone 3, stress increased from ≥ 3° in type B and ≥ 4° in type C. In zone 4, there was a significant increase in stress at varus angles of ≥ 2° in types A and B and at ≥ 3° in type C. CONCLUSION: In zone 2, the varus angle at which stress shielding above Engh classification grade 3 may appear is expected to be ≥ 3°. Distal cortical hypertrophy may appear in zones 3 and 4; the narrower the medullary cavity shape, the smaller the allowable angle of internal recession, and the wider the medullary cavity shape, the wider the allowable range. Long-term follow-up is required in patients with varus angles > 3°.

Comparison of periprosthetic bone mineral density between two types of short-stems in total hip arthroplasty with a mean follow-up of 4 years.

INTRODUCTION: The use of short stems in primary hip arthroplasty has grown considerably in recent years, with a large variety of designs and stabilization methods available. Few studies have directly compared how these designs and fixation modes influence the bone mineral density (BMD) that is said to be better preserved with shorter implants. This led us to carry out a medium-term retrospective comparative study to (1) specify how the design of two different types of short stems influences the periprosthetic BMD, (2) compare the radiological and clinical outcomes of these stems. HYPOTHESIS: The periprosthetic BMD of a short stem varies based on the implant's design. MATERIALS AND METHODS: Ninety-three patients underwent total hip arthroplasty (THA) with a short stem between July 2012 and July 2014. Two groups of patients were formed: Vitae™ short stem (Adler Ortho, Milan, France), Optimys™ short stem (Mathys, Bettlach, Switzerland). The Vitae group consisted of 46 patients, while the Optimys group consisted of 47 patients. The mean age was 66 years, and the mean body mass index (BMI) was 26 kg/m2. The groups had comparable age, BMI, sex, Harris Hip score and preoperative radiological features. Periprosthetic BMD of the two types of implants was determined between the 1st and 4th year postoperative using dual-energy x-ray absorptiometry (DEXA) in the Gruen zones. The radiological and clinical outcomes were also determined. RESULTS: There was a significant decrease in BMD in zone 7(-5.8%±0.1 CI95%[-0.09; -0.02] (p=0.003)), zone 2 (-4.8% ±0.1 CI95%[-0.093; -0.003] (p=0.038)) and zone 6 (-11% ±0.2 CI95%[-0.19; -0.03] (p=0.009)) in the patients with Vitae stems and in zone 2 (-13.7%±0.3 CI95%[-0.25; -0.03] (p=0.018)) in the patients with Optimys stems. A significant difference in BMD in zone 7 at 1 year (p=0.014) and 4 years (p=0.001) postoperative and in zone 6 (p=0.011) at 4 years postoperative existed between groups, with the Optimys group having higher BMD. There was a significant increase in femoral offset in the Optimys group but not the Vitae group: Δoffset=-0.50 mm±5.2 CI95%[-2.05; 1.05] (p=0.522) and Δoffset=2.79 mm±4.2 CI95%[1.21; 4.37] (p=0.001). The Harris Hip score was not significantly different between the two groups at 4 years postoperative (95.3±2.5 [88; 99] vs. 95.2±2.6 [88; 99] (p=0.991)). DISCUSSION: The design of short stems appears to influence the distribution of loads and the periprosthetic BMD. These stems are associated with very good radiological and clinical results in the medium term. Bone remodeling appears to continue beyond 1 year after the THA procedure. LEVEL OF EVIDENCE: III; Retrospective case-control study.

Short-Term Analysis of the Changes in the Bone Mineral Density of the Proximal Femur After Uncemented Total Hip Arthroplasty: A Prospective Study of 110 Patients.

Introduction Mechanical loading continuously exposes the bone to remodeling processes. Increased load leads to a gain in bone mass, and reduced load results in a loss. After inserting a prosthesis, the proximal femur is bypassed in loading as the bodyweight shifts distally. This lack of load induces bone resorption according to Wolff's law. To avoid this bone resorption, the implant's bending stiffness should be less than the femoral bone. Dual-energy X-ray absorptiometry (DEXA) is a well-accepted method to measure periprosthetic bone mineral density (BMD) after total hip arthroplasty (THA). Since the strength and durability of the fixation of a femoral prosthesis in cementless hip arthroplasty depend largely on the quantity and quality of the surrounding bone, preoperative and postoperative evaluation of the quantity and quality of the femoral bone is very important in the long-term prognosis of hip arthroplasty. Materials and methods A prospective study of 110 patients in the age group of 25-60 years who underwent uncemented total hip arthroplasty in our tertiary healthcare institution was performed. An uncemented, fully hydroxyapatite-coated implant from a single manufacturer was used in all the patients. All the patients were mobilized on the first post-operative day. The BMD was measured at the proximal femur and the distal tip using a DEXA scan. Gruen zones were used for calculating BMD at different anatomical locations in the femur, with particular importance to zones 1, 4, and 7. Results The pre-operative BMD in all zones measured, viz. zones 1, 4, and zone 7 of the affected side, was found to be significantly lower as compared to the BMD values on the control side (P< 0.05). The mean change in the mean BMD was calculated for all the zones and compared with each other using an unpaired t-test. The mean BMD changes were found to be significantly higher in zone 7 in comparison to both zones 1 and 4 (p<0.05). Conclusion Significant periprosthetic bone loss after uncemented THA in the femur was noted in Gruen zones 1, 4, and 7 during the first six months after THA, with the greatest bone loss in the femoral calcar area (zone 7). The lower the preoperative BMD of the patient, the greater the postoperative bone loss.

Distal femoral cortical hypertrophy not associated with thigh pain using a short stem femoral implant.

BACKGROUND: Thigh pain following a well-fixed total hip arthroplasty (THA) remains problematic and a source of patient dissatisfaction. The purpose of this study is to evaluate if the development of distal femoral cortical hypertrophy (DFCH) is associated with postoperative thigh pain after THA. METHODS: All patients who underwent an uncomplicated primary THA via a direct anterior approach with the Taperloc Microplasty (Zimmer Biomet, Warsaw, IN, USA) implant between 2011 and 2015 were mailed a pain drawing questionnaire. Radiographs were reviewed at 1 year minimum to determine cortical thickness change from immediate post-op. Thigh pain was compared to DFCH. 293 patients were included in the study. RESULTS: Mean follow-up was 3.2 years. A total of 218 hips (74%) had cortical hypertrophy in Gruen zone 3 and 165 hips (56%) had cortical hypertrophy in Gruen zone 5. 52 hips (18%) had ⩾25% cortical hypertrophy in zone 3 and 91 hips (31%) had ⩾25% cortical hypertrophy in zone 5. A total of 44 patients (15%) reported anterior thigh pain and 43 patients (15%) reported lateral thigh pain. Development of DFCH in either Gruen zone 3 or 5 was not associated with anterior or lateral thigh pain. Stem size was positively correlated with zone 3 hypertrophy and inversely related to zone 5 hypertrophy. Thigh pain was not associated with patient age, gender, activity level or stem size. CONCLUSIONS: The development of distal femoral cortical hypertrophy after THA with a short stem implant was high, but not associated with patient-reported anterior or lateral thigh pain.

Bone Loss Following Cementless Hemiarthroplasty for the Treatment of Femoral Neck Fracture.

BACKGROUND: With the advances in medicine, an increasing number of the ageing population are a public health concern in terms of age-related complications. Among them, displaced neck fractures often require surgical intervention or arthroplasty to achieve the mobilization of the elderly and good life quality. The aim of the study is to monitor the changes in bone mineral density (BMD) around the femoral stem and the effects on functional outcomes in patients treated with cementless hemiarthroplasty following femoral neck fracture. MATERIALS AND METHODS: Seventy-one patients aged 70 years or older who were treated with cementless hemiarthroplasty for a displaced femoral neck fracture were prospectively followed for 2 years. The percent change in the periprosthetic BMD in each Gruen zone was compared to the baseline using dual-energy X-ray absorptiometry (DEXA). Demographic factors [age, body mass index (BMI), and sex] that could possibly influence BMD and the clinical outcome were evaluated. RESULTS: Fifty-one patients were available for the final follow-up. The mean age was 76.5 (range 70-89) years. The mean BMI was 28.9 (range 22.7-37.2). The mean Harris hip score at the final follow-up was 84.3 (range 72-93). There was a significant decrease in BMD in all Gruen zones (p < 0.001), except in zone 3 (R3, p = 0.547). The reduction in BMD was highest in the calcar and the greater trochanter region. The femur diaphysis was relatively spared, with zone 3 showing no significant bone mineral loss. The age and BMI of the patients were not correlated with the postoperative change in BMD in any of the Gruen zones. The degree of reduction in bone density was not correlated with the clinical outcome. CONCLUSIONS: Cementless hemiarthroplasty for the treatment of femoral neck fracture in elderly patients achieves a good clinical outcome despite significant bone loss around the femoral stem. The reduction in BMD is more pronounced in the metaphyseal region.

Perioperative patient-specific factors-based nomograms predict short-term periprosthetic bone loss after total hip arthroplasty.

BACKGROUND: Although medical intervention of periprosthetic bone loss in the immediate postoperative period was recommended, not all the patients experienced periprosthetic bone loss after total hip arthroplasty (THA). Prediction tools that enrolled all potential risk factors to calculate an individualized prediction of postoperative periprosthetic bone loss were strongly needed for clinical decision-making. METHODS: Data of the patients who underwent primary unilateral cementless THA between April 2015 and October 2017 in our center were retrospectively collected. Candidate variables included demographic data and bone mineral density (BMD) in spine, hip, and periprosthetic regions that measured 1 week after THA. Outcomes of interest included the risk of postoperative periprosthetic bone loss in Gruen zone 1, 7, and total zones in the 1st postoperative year. Nomograms were presented based on multiple logistic regressions via R language. One thousand Bootstraps were used for internal validation. RESULTS: Five hundred sixty-three patients met the inclusion criteria were enrolled, and the final analysis was performed in 427 patients (195 male and 232 female) after the exclusion. The mean BMD of Gruen zone 1, 7, and total were decreased by 4.1%, 6.4%, and 1.7% at the 1st year after THA, respectively. 61.1% of the patients (261/427) experienced bone loss in Gruen zone 1 at the 1st postoperative year, while there were 58.1% (248/427) in Gruen zone 7 and 63.0% (269/427) in Gruen zone total. Bias-corrected C-index for risk of postoperative bone loss in Gruen zone 1, 7, and total zones in the 1st postoperative year were 0.700, 0.785, and 0.696, respectively. The most highly influential factors for the postoperative periprosthetic bone loss were primary diagnosis and BMD in the corresponding Gruen zones at the baseline. CONCLUSIONS: To the best of our knowledge, our study represented the first time to use the nomograms in estimating the risk of postoperative periprosthetic bone loss with adequate predictive discrimination and calibration. Those predictive models would help surgeons to identify high-risk patients who may benefit from anti-bone-resorptive treatment in the early postoperative period effectively. It is also beneficial for patients, as they can choose the treatment options based on a reasonable expectation following surgery.

Long term survival analysis of cementless Spotorno femoral stem in young patients.

OBJECTIVE: The aim of this study was to analyze the survivorship and clinical outcome of Cementless Spotorno (CLS) stem in young patients. METHODS: A total of 99 consecutive hip arthroplasties using CLS stem were performed on 84 patients younger than 50 years of age between 1993 and 2001. 63 patients were available for final follow-up (mean age: 39 ± 7.8 (range: 22-50)). Patients' Harris Hip Scores (HHS) and survivorship estimates were calculated. Radiographs were analyzed for acetabular implant status, canal fill index (CFI), stem alignment, osteolysis, and stress shielding. RESULTS: Mean follow-up time was 18 years (13-3), and mean HHS was 88.7 (58-100). Patients with femoral neck fracture had a more favorable functional outcome (p = 0.027), while those with stems in varus had lower scores (p = 0.017). 31 stems (49%) were undersized and 30 hips (47%) had perifemoral osteolysis. Acetabular impairment was strongly associated with osteolysis in Gruen zones 1 and 7 (p < 0.01). Seventeen of the osteolytic lesions occurred in Gruen zone 1, 4 lesions in zone 2, 9 in zone 6 and 22 in zone 7. Forty nine stems were well aligned, 10 were in varus and 5 in valgus. Six patients presented with grade 1 stress shielding, 42 with grade 2, 9 with grade 3 and 7 with grade 4. Pedestal formation was evident in 13 cases. Kaplan-Meier survivorship estimates at 18 years with revision for any reason as the end point and with septic revisions excluded were 91.2% (95% CI: 83.7%-98.7%) and 95.1% (95% CI: 89.5%-100%), respectively. There was no difference between survival estimates of patients with different etiologies. CONCLUSION: CLS stems in young patients have high survival estimates in the long term with good-excellent results. Spotorno stems perform equally well in all etiologies with no difference in terms of survivorship. LEVEL OF EVIDENCE: Level IV Therapeutic study.