The lexicon for periprosthetic bone loss versus osteolysis after cervical disc arthroplasty: a systematic review

Background Periprosthetic bone loss is a common observation following arthroplasty. Recognizing and understanding the nature of bone loss is vital as it determines the subsequent performance of the device and the overall outcome. Despite its significance, the term “bone loss” is often misused to describe inflammatory osteolysis, a complication with vastly different clinical outcomes and treatment plans. Therefore, the goal of this review was to report major findings related to vertebral radiographic bone changes around cervical disc replacements, mitigate discrepancies in clinical reports by introducing uniform terminology to the field, and establish a precedence that can be used to identify the important nuances between these distinct complications. Methods A systematic review of the literature was conducted following PRISMA guidelines, using the keywords “cervical,” “disc replacement,” “osteolysis,” “bone loss,” “radiograph,” and “complications.” A total of 23 articles met the inclusion criteria with the majority being retrospective or case reports. Results Fourteen studies reported periprosthetic osteolysis in a total of 46 patients with onset ranging from 15–96 months after the index procedure. Reported causes included: metal hypersensitivity, infection, mechanical failure, and wear debris. Osteolysis was generally progressive and led to reoperation. Nine articles reported non-inflammatory bone loss in 527 patients (52.5%), typically within 3–6 months following implantation. The reported causes included: micromotion, stress shielding, and interrupted blood supply. With one exception, bone loss was reported to be non-progressive and had no effect on clinical outcome measures. Conclusions Non-progressive, early onset bone loss is a common finding after CDA and typically does not affect the reported short-term pain scores or lead to early revision. By contrast, osteolysis was less common, presenting more than a year post-operative and often accompanied by additional complications, leading to revision surgery. A greater understanding of the clinical significance is limited by the lack of long-term studies, inconsistent terminology, and infrequent use of histology and explant analyses. Uniform reporting and adoption of consistent terminology can mitigate some of these limitations. Executing these actionable items is critical to assess device performance and the risk of revision. Level of Evidence IV Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Continuous periprosthetic bone loss but preserved stability for a collum femoris-preserving stem: follow-up of a prospective cohort study of 21 patients with dualenergy X-ray absorptiometry and radiostereometric analysis with minimum 8 years of follow-up

Background and purpose — We previously described a decrease in bone mineral density (BMD) in the calcar region 2 years after insertion of the collum femoris-preserving (CFP) stem, but the implants were stable. Now we have examined the long-term changes in periprosthetic BMD and stability of the CFP stem. Patients and methods — We conducted a minimum 8-year follow-up of 21 patients from our original investigation. We examined periprosthetic BMD by dual-energy X-ray absorptiometry (DEXA) and implant stability by radiostereometric analysis (RSA). Results — Between 2 and 8 years 1 stem was revised due to aseptic loosening. Between 2 and 8 years we found a 14% (95% confidence interval [CI] 9–19) reduction in BMD in Gruen zone 6 and 17% (CI 6–28) in Gruen zone 7. From baseline the reduction in BMD was 30% (CI 23–36) in Gruen zone 6, 39% (CI 31–47) in Gruen zone 7, and 19% (CI 14–23) in Gruen zone 2. Between 2 and 8 years, RSA (n = 17) showed a mean translation along the stem axis of 0.02mm (CI –0.02 to 0.06) and a mean rotation around the stem axis of 0.08° (CI –0.26 to 0.41). From baseline mean subsidence was 0.07 mm (CI –0.16 to 0.03) and mean rotation around the stem axis was 0.23° (CI –0.23 to 0.68) at 8 years. Interpretation — There was continuous loss of proximomedial BMD at 8 years while the CFP stem remained stable. Proximal periprosthetic bone loss cannot be prevented by this stem.

Influence of alendronate therapy on the results of densitometric examination after implantation of total hip endoprosthesis

The development of aloarthroplasty of the hip is continuously rising. After implantation of a total cement-free hip endoprosthesis, often there is a periprosthetic femoral bone loss. Alendronate has been shown to be a potent inhibitor of bone resorption activity; it inhibits osteoclastic bone resorption, increases bone mass, and plays a significant role in post-implantation stabilization of the femur. The aim of this study was to determine the effect of alendronate on osteointegration of hip endoprosthesis.Material and methods: The study analyzed 10 patients operated on with implantation of a total cement-free hip endoprosthesis (THP). The included patients were examined by a radiographic method at 6 and 12 months and DXA method at 6 and 12 months. Results: The study showed differences in the values of bone mineral density and bone mineral content in the interval between 6 and 12 months in patients undergoing THP, and hence we can conclude that alendronate therapy after THP implantation reduced periprosthetic loss of bone mass and implant stiffening. Alendronate is a proven inhibitor of periprosthetic bone loss that occurs after prirmary impantation of a total cement-free hip endoprosthesis.

Predicting Bone Remodeling in Response to Orthopedic Implantations: Computational Study Using a Mechano-Biochemical Model

Periprosthetic bone loss following orthopedic implantations is a serious concern leading to the premature failure of the implants. Therefore, investigating bone remodeling in response to orthopedic implantations is of paramount importance for the purpose of designing long lasting prostheses. In this study, a predictive bone remodeling model (Thermodynamic-based model) was employed to simulate the long-term response of femoral density to total hip arthroplasty (THA), bone fracture plating and intramedullary (IM) nailing. The ability of the model in considering the coupling effect between mechanical loading and bone biochemistry is its unique characteristic. This research provided quantitative data for monitoring bone density changes throughout the femoral bone. The results obtained by the thermodynamic-based model agreed well with the bone morphology and the literature. The study revealed that the most significant periprosthetic bone loss in response to THA occurred in calcar region (Gruen zone 7). Conversely, the region beneath the hip stem (Gruen zone 4) experienced the lowest bone mineral density (BMD) changes. It was found that the composite hip implant and IM nail were more advantageous over the metallic ones as they induced less stress shielding and provided more uniform bone density changes following the surgery. The research study also showed that, due to plating, the areas beneath the bone fracture plate experienced severe bone loss. However, some level of bone formation was observed at the vicinity of the most proximal and distal screw holes in both lateral and anterior plated femurs. Furthermore, in terms of long-term density distributions, the anterior plating was not superior to the lateral plating.

Predicting Bone Remodeling in Response to Orthopedic Implantations: Computational Study Using a Mechano-Biochemical Model

Periprosthetic bone loss following orthopedic implantations is a serious concern leading to the premature failure of the implants. Therefore, investigating bone remodeling in response to orthopedic implantations is of paramount importance for the purpose of designing long lasting prostheses. In this study, a predictive bone remodeling model (Thermodynamic-based model) was employed to simulate the long-term response of femoral density to total hip arthroplasty (THA), bone fracture plating and intramedullary (IM) nailing. The ability of the model in considering the coupling effect between mechanical loading and bone biochemistry is its unique characteristic. This research provided quantitative data for monitoring bone density changes throughout the femoral bone. The results obtained by the thermodynamic-based model agreed well with the bone morphology and the literature. The study revealed that the most significant periprosthetic bone loss in response to THA occurred in calcar region (Gruen zone 7). Conversely, the region beneath the hip stem (Gruen zone 4) experienced the lowest bone mineral density (BMD) changes. It was found that the composite hip implant and IM nail were more advantageous over the metallic ones as they induced less stress shielding and provided more uniform bone density changes following the surgery. The research study also showed that, due to plating, the areas beneath the bone fracture plate experienced severe bone loss. However, some level of bone formation was observed at the vicinity of the most proximal and distal screw holes in both lateral and anterior plated femurs. Furthermore, in terms of long-term density distributions, the anterior plating was not superior to the lateral plating.

Denosumab might prevent periprosthetic bone loss after total hip and knee arthroplasties: a review

Total hip arthroplasty and total knee arthroplasty are extensively used for the treatment of the end-stage degenerative joint diseases. Currently, periprosthetic bone loss is still the major cause of aseptic loosening, resulting in implant failures. Previous literature introduced some widely accepted protocols for the prevention and treatment of periprosthetic bone loss, but no guideline has been proposed. Denosumab, a human monoclonal immunoglobulin G2 (IgG2) antibody, can inhibit bone resorption by binding to the receptor activator of nuclear factor kappa-B ligand (RANKL). This article reviews the present findings and evidence concerning the effect of denosumab on the periprosthetic bone loss after total hip arthroplasty and total knee arthroplasty. Overall, the current evidence suggests that denosumab is a promising agent for the treatment of periprosthetic bone loss.

Intra-operative Clodronate Rinsing Improves the Integration of the Femoral Stem in a Prospective, Double-blinded, Randomized, Placebo-controlled Clinical RSA-study

Background: Periprosthetic bone loss after Total Hip Arthroplasty (THA), detected as an early migration of the prosthesis may predict later loosening of the implant. Objective: We hypothesized that intra-operative bisphosphonate rinsing would reduce bone resorption after THA. It might therefore be possible to achieve better early fixation of the implant. Methods: Nineteen patients suffering from arthrosis were recruited in a prospective, double-blinded, randomized, placebo-controlled clinical pilot trial. Patients were operated with an uncemented Bimetric stem using tantalum markers. The femoral proximal intramedullary canal was rinsed with 1mM clodronate in nine patients and with saline in 10 patients. These patients were followed for two years using radiostereometric analysis (RSA), dual energy x-ray absorptiometry (DXA) and the Harris Hip Score (HHS). Results: We did not found any significant differences between the study groups with regards to the primary output measures (maximum total point motion, MTPM). However, there was evidence that clodronate could affect periprosthetic bone quality; a beneficial effect in BMD in Gruen zone 3 during the two-year follow-up was observed, BMD decreased less in the clodronate group (p = 0.02). The maximal x-translation of the stem at 3-24 months was significantly two-fold, being higher in the placebo group (p = 0.02). The baseline BMD and the maximal total point motion (MTPM) at 3-24 months showed a positive correlation in the clodronate group and a negative correlation in the placebo group. Conclusion: In conclusion, further studies with larger patient groups and longer follow-up periods are needed to estimate the clinical importance of these findings and further to prove if an intraoperative clodronate rinsing prior to application of femoral stem during THA can prevent periprosthetic bone loss. Clinical Trial Registration No.: NCT03803839

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.