Extensive Bone Loss Research Articles

Gorham-Stout disease and multiple cervical lymphangiomas: case report.

Gorham-Stout disease is a rare condition characterized by extensive bone loss due to the proliferation of new vascular and lymphatic structures. It can occur in any bone and cause pathologic fractures with poor bone healing. Complications such as effusions and lymphangiomas can also develop. Gorham-Stout disease pathogenesis is still being studied, and treatment options are limited, but sirolimus has shown promise in stabilizing or reducing symptoms. We present a case of a 19-year-old male with Gorham-Stout disease, multiple cervical lymphangiomas, and several thoracic complications successfully treated with sirolimus. Rare lymphatic diseases should be considered as a potential cause in adult patients with bone involvement and multiple cystic lesions in the neck, axillary, or abdominal regions after excluding more common causes. The complexity of diagnosing Gorham-Stout disease should be emphasized.

Successful Regenerative Endodontic Therapy of a Dens Evaginatus Mandibular Second Premolar with an Acute Apical Abscess and Extensive Periapical Bone Loss: A Case Report.

Regenerative endodontics is a rapidly growing field within dentistry that aims to replace damaged tooth structures and cells of the pulp-dentin complex. This case report presents the successful management of an immature permanent second mandibular premolar with an acute apical abscess and extensive apical bone loss caused by a dens evaginatus. This tooth was unexpectedly treated with long-term calcium hydroxide (Ca(OH)2) that was replenished several times over 6 months. During the treatment process, this tooth became reinflamed developing a chronic apical abscess after resolution of the initial acute apical abscess, which resulted in the replacement and prolonged use of Ca(OH)2. The final regenerative procedures were completed using a bioceramic fast set putty placed directly over the blood clot and an occlusal composite restoration. At the 6-month follow-up, the patient was asymptomatic with a fully healed radiographic lesion, new periodontal ligament, and the apex closed with thickening of the mesial and distal aspects of the root. At the 15-month follow-up, the patient remained asymptomatic with continued evidence of radiographic development of the apical aspect of this tooth, displaying root end closure and thickening. This is a unique case report of the management of a complex infection process in an immature tooth with regenerative techniques with repeated and long-term use of Ca(OH)2. This novel report provides dental practitioners with a new potential protocol for the management of these immature cases with advanced periapical infections that require extensive disinfection to have successful outcomes.

Hemisection Procedure Facilitated by 3D Printing and a Customized Surgical Guide: A Novel Approach

When there is a lesion in a multi-rooted tooth, but only one root is infected, resective therapies are an effective treatment option for maintaining natural tooth structure. Hemisection may be the best line of action when a single root is decayed or periodontally compromised, but the other is intact. As precision and accuracy are paramount in ensuring the success of this procedure, this case explores the integration of 3D printing technology to create a patient-specific surgical guide that demonstrates excellent adaptability and precision during hemisection procedures. The integration of 3D printing technology in hemisection procedures, through the use of a customized surgical guide, offers a promising avenue for precision dentistry. This case report depicts a situation where the distal root of LR6 had extensive bone loss. Hemisection was planned for the tooth using 3D printing and a customized surgical guide to perform the procedure preserving the mesial root. CPD/Clinical Relevance: The use of patient-specific surgical guides, along with CBCT and 3D printing, can enhance the clinical outcome for hemisection.

Sclerostin Antibody-Loaded Dense Collagen Hydrogels Promote Critical-Size Bone Defect Repair.

The management of extensive bone loss remains a clinical challenge. Numerous studies are underway to develop a combination of biomaterials, biomolecules, and stem cells to address this challenge. In particular, the systemic administration of antibodies against sclerostin, a regulator of bone formation, was recently shown to enhance the bone repair efficiency of dense collagen hydrogels (DCHs) hosting murine dental pulp stem cells (mDPSCs). The aim of the present study was to assess whether these antibodies, encapsulated and released from DCHs, could promote craniofacial bone repair by the local inhibition of sclerostin. In vitro studies showed that antibody loading modified neither the hydrogel structure nor the viability of seeded mDPSCs. When implanted in a mouse calvaria critical-size bone defect, antibody-loaded DCHs showed repair capabilities similar to those of acellular unloaded DCHs combined with antibody injections. Importantly, the addition of mDPSCs provided no further benefit. Altogether, the local delivery of antisclerostin antibodies from acellular dense collagen scaffolds is highly effective for bone repair. The drastic reduction in the required amount of antibody compared to systemic injection should reduce the cost of the procedure, making the strategy proposed here a promising therapeutic approach for large bone defect repair.

Natural Affinity Driven Modification by Silicene to Construct a "Thermal Switch" for Tumorous Bone Loss.

Tumorous bone defects present significant challenges for surgical bio-reconstruction due to the dual pathological conditions of residual tumor presence and extensive bone loss following excision surgery. To address this challenge, a "thermal switch" smart bone scaffold based on the silicene nanosheet-modified decalcified bone matrix (SNS@DBM) is developed by leveraging the natural affinity between collagen and silicene, which is elucidated by molecular dynamics simulations. Benefitting from its exceptional photothermal ability, biodegradability, and bioactivity, the SNS@DBM "thermal switch" provides an integrated postoperative sequential thermotherapy for tumorous bone loss by exerting three levels of photothermal stimulation (i.e., strong, moderate, and nonstimulation). During the different phases of postoperative bioconstruction, the SNS@DBM scaffold realizes simultaneous residual tumor ablation, tumor recurrence prevention, and bone tissue regeneration. These biological effects are verified in the tumor-bearing nude mice of patient-derived tissue xenografts and critical cranium defect rats. Mechanism research prompts moderate heat stimulus generated by and coordinating with SNSs can upregulate osteogenic genes, promote macrophages M2 polarization, and intensify angiogenesis of H-type vessels. This study introduces a versatile approach to the management of tumorous bone defects.

Wrist Arthrodesis with Double Ulna Intussusception for Failed Wrist Arthroplasty

Abstract Background Salvage procedures for failed total wrist arthroplasty have variable results and limitations such as donor site morbidity, malunion, delayed or nonunion. We present a case of substantial bone loss after failed wrist arthroplasty and a surgical technique in which the distal ulna is transferred and intussuscepted to achieve union between the residual distal radius and metacarpals. Case Description A 48-year-old female with rheumatoid arthritis presented with wrist prosthetic joint infection 16 years after total wrist arthroplasty. With extensive bone loss following implant removal and multiple debridements, the remaining distal ulna was resected and intussuscepted between the residual radius and second and third metacarpals. The patient achieved incorporation of the graft at 12 weeks and fusion at 20 weeks, with resolution of pain and restoration of digit function at 2 years. Literature Review Standard means of wrist arthrodesis utilizing iliac crest autograft and femoral head allograft may be limited to address substantial bone loss following total wrist implant removal. Intussusception has been utilized in the elbow, hip, and diaphysis to optimize graft–host bone contact and achieve union. While ulna-utilizing procedures have been described for oncologic and traumatic indications, to our knowledge, double intussusception has not been described for salvage procedures after failed wrist arthroplasty. Clinical Relevance Intussuscepting the distal ulna within the distal radius and metacarpals as an interpositional arthrodesis provides autologous graft, increased surface contact, and length restoration in cases of poor bone quality and significant bone loss following revision of a total wrist implant.

A comparison of dislocation risk between dual mobility and traditional constructs used in proximal femoral replacement

BackgroundProximal femoral replacement (PFR) is a reconstruction technique after tumor resection or for revision of failed total hip arthroplasty (THA). However, despite acceptable long-term oncologic and functional outcomes, extensive soft tissue or bone loss increases the risk for prosthetic instability. Instability may depend on the construct chosen for reconstruction, with current options including bipolar, constrained, or dual mobility implants. Clinical studies comparing patient outcomes after PFR with these three different constructs are limited. MethodsThis study retrospectively examined a single tertiary academic institution's experience with PFR over a fifteen-year period. The medical records of patients who underwent PFR for indications such as tumor and failed THA with bone loss were reviewed. Patients were stratified into cohorts based on use of bipolar, constrained, or dual mobility implants. Patient demographics, disease characteristics, perioperative data, and data on prosthetic dislocations were recorded. ANOVA and chi-square testing was performed for continuous and categorical variables, respectively. The threshold for statistical significance was set to p < 0.05. Results106 patients were identified who underwent PFR. 46 underwent PFR with bipolar prosthesis (follow-up: 20 ± 24.57 months), 42 with constrained liner (follow-up: 30.45 ± 35.32 months), and 18 with dual mobility (follow-up: 15.38 ± 15.67 months). Only BMI (p = 0.036) and smoking history (P = 0.002) differed between groups. Dislocations occurred in 4 (8.7 %) patients who underwent reconstruction with bipolar prosthesis, compared to 8 (19.0 %) with constrained liner, and 3 (16.7 %) patients with dual mobility. Mean time to dislocation was significantly longer in dual mobility patients (P = 0.009). There were no differences in instances of early dislocation between groups (P = 00.238). ConclusionWhile study numbers are low, mean time to dislocation was significantly longer with dual mobility. Additional large-scale longitudinal studies are needed to fully elucidate the differences in outcomes amongst these three treatments.

Effect of Glenoid Bone Loss and Shoulder Position on Axillary Nerve Anatomy During the Latarjet Procedure.

The Latarjet procedure is increasingly being utilized for the treatment of glenoid bone loss and has a relatively high neurological complication rate. Understanding the position-dependent anatomy of the axillary nerve (AN) is crucial to preventing injuries. To quantify the effects of changes in the shoulder position and degree of glenoid bone loss during the Latarjet procedure on the position of the AN. Controlled laboratory study. A total of 10 cadaveric shoulders were dissected, leaving the tendons of the rotator cuff and deltoid for muscle loading. The 3-dimensional position of the AN was quantified relative to the inferior glenoid under 3 conditions: (1) intact shoulder, (2) Latarjet procedure with 15% bone loss, and (3) Latarjet procedure with 30% bone loss. Measurements were obtained at 0°, 30°, and 60° of glenohumeral abduction (equivalent to 0°, 45°, and 90° of shoulder abduction) and at 0°, 45°, and 90° of humeral external rotation (ER). Abduction of the shoulder to 60° resulted in a posterior (9.5 ± 1.1 mm; P < .001), superior (3.0 ± 1.2 mm; P = .013), and lateral (19.1 ± 2.3 mm; P < .001) shift of the AN, and ER to 90° resulted in anterior translation (10.0 ± 1.2 mm; P < .001). Overall, ER increased the minimum AN-glenoid distance at 30° of abduction (14.9 ± 1.3 mm [0° of ER] vs 17.3 ± 1.5 mm [90° of ER]; P = .045). The Latarjet procedure with both 15 and 30% glenoid bone loss resulted in a superior and medial shift of the AN relative to the intact state. A decreased minimum AN-glenoid distance was seen after the Latarjet procedure with 30% bone loss at 60° abduction and 90° ER (17.7 ± 1.6 mm [intact] vs 13.9 ± 1.6 mm [30% bone loss]; P = .007), but no significant differences were seen after the Latarjet procedure with 15% bone loss. Abduction of the shoulder induced a superior, lateral, and posterior shift of the AN, and ER caused anterior translation. Interestingly, the Latarjet procedure, when performed on shoulders with extensive glenoid bone loss, significantly reduced the minimum AN-glenoid distance during shoulder abduction and ER. These novel findings imply that patients with substantial glenoid bone loss may be at a higher risk of AN injuries during critical portions of the procedure. Consequently, it is imperative that surgeons account for alterations in nerve anatomy during revision procedures. This study attempts to improve understanding of the position-dependent effect of shoulder position and glenoid bone loss after the Latarjet procedure on AN anatomy. Improved knowledge of AN anatomy is crucial to preventing potentially devastating AN injuries during the Latarjet procedure.

Comparable Results of Single and Two-Stage Exchange for Select Periprosthetic Hip and Knee Infection.

Although two-stage exchange has been the standard of care for periprosthetic joint infection (PJI) in the United States, single-stage exchange is emerging as an option in select patients. The purpose of this study was to compare outcomes of patients undergoing single-stage and two-stage exchange using strict surgical indications. We reviewed a consecutive series of 196 patients with diagnosed PJI undergoing revision total knee and hip arthroplasty from 2017 to 2021. Patients were excluded if they had PJI history, plastic surgery coverage, or extensive bone loss requiring endoprosthesis. We compared the number of patients PJI-free at 1-year follow-up using MusculoSkeletal Infection Society criteria and patients requiring re-revision between the single-stage and two-stage groups. In total, 126 patients met inclusion criteria. Of 61 knee patients (48.4%), 22 underwent single-stage (36%) and 39 underwent two-stage (63.9%). Of 65 hip patients (51.6%), 38 underwent single-stage (58.5%) and 27 underwent two-stage (41.5%). At a mean follow-up of 1.95 ± 0.88 years, a higher rate of knee patients were classified as having treatment success in the single-stage group (77.3% versus 69.2%, P = 0.501), however with comparable septic failure rates (18.1% single-stage versus 17.9% two-stage; P = 0.982). At a mean follow-up of 1.81 ± 0.9 years, a higher rate of hip patients were classified as having treatment success in the single-stage group (94.7% versus 81.5%, P = 0.089), and more patients had septic failures in the two-stage group (18.5% versus 5.3%; P = 0.089). No differences were observed in the microorganism profile. More total complications (P = 0.021) and mortalities were found in the single-stage knee cohort than in the two-stage cohort (22.7% versus 2.6%; P = 0.011). Single-stage arthroplasty is a viable alternative to standard two-stage exchange in patients with PJI without a history of infection and with no bone or soft-tissue compromise. Additional studies with longer term follow-up are needed to evaluate its efficacy.

Clinical Outcomes of Polyetheretherketone (PEEK) Hybrid Prosthesis in All-on-Four Rehabilitation: A Systematic Review Protocol

Background The “all-on-four” concept represents a significant advancement in dental implantology. particularly beneficial in cases of extensive jaw bone loss where invasive bone regeneration procedures are typically required. However, the successful implementation of this technique necessitates meticulous planning concerning implant selection, materials, and prosthesis design. The recent introduction of PEEK (Polyetheretherketone) in dentistry, especially in all-on-four prosthetics, prompts questions regarding its clinical efficacy and comparative biomechanical and biological advantages over conventional materials such as titanium and zirconia. While some studies have compared PEEK with other materials, systematic reviews evaluating its efficacy are scarce. This systematic review protocol intends to assess the evidence regarding the viability of PEEK as a potential alternative within the all-on-four approach in dental implantology. Methods This systematic review protocol will adhere to the Cochrane Handbook for Systematic Review of Interventions and align with the Methodological Expectations of the Cochrane Intervention Reviews (MECIR) guidelines. Utilizing a comprehensive search strategy, multiple databases, including PubMed, EMBASE, Scopus, EBSCO, Web of Science, Cochrane Central, and registries of clinical trials, will be explored. The search aims to identify randomized controlled trials and non-randomized studies investigating the application of PEEK in the all-on-four approach for dental procedures. Emphasizing clinically relevant outcomes such as implant survival, prosthesis success, peri-implant complications, and patient satisfaction, this review aims to provide insights into the effectiveness and potential benefits of using PEEK in all-on-four prosthetics. Non-randomized studies will be assessed for bias using ROBINS-I, while randomized controlled trials will undergo evaluation with the Cochrane Risk of Bias assessment tool, ROB II. Discussion The outcomes derived from this systematic review hold great significance for dental practitioners exploring the all-on-four concept. Understanding PEEK’s advantages and limitations compared to titanium and zirconia facilitates tailored treatment plans, enhancing success and satisfaction, ultimately improving dental care quality. Systematic review registration PROSPERO: CRD42024531175 (Registered on 13/04/2024).

CLINICAL AND RADIOLOGICAL OUTCOMES OF A TAPERED FLUTED TITANIUM MONOBLOC REVISION STEM IN HIP ARTHROPLASTY AT SIX YEARS

We had previously reported on early outcomes on a new fluted, titanium, monobloc stem with a three degree taper that has been designed for challenging femoral reconstruction in the setting of extensive bone loss. The aim of this study was to report its mid-term clinical and radiographic outcomes.This is a retrospective review of prospectively collected data carried out at a single institution between Jan 2017 and Dec 2019. 85 femoral revisions were performed using a new tapered, fluted, titanium, monobloc (TFTM) revision stem. Complications, clinical and radiographic data were obtained from medical records and a locally maintained database. Clinical outcomes were assessed using the Oxford Hip Score (OHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). All post-operative radiographs were analysed for subsidence, osteolysis and femoral cortical bone remodelling.Mean follow-up was 60 months (range 28–84 months). Subsidence of 1.2 mm was noted in one patient. No cases of clinically significant subsidence (10 mm) were observed. At final follow-up, a statistically significant improvement was noted in functional outcome scores. The mean OHS preoperatively and at final follow-up were 24 (SD 13) and 42 (SD15). p = 0.04 mean difference 18 (95% CI 15–22). The mean WOMAC scores preoperatively and at final follow-up were 62 (SD23) and 88 (SD7) respectively (p &lt; 0.001, mean difference 26; 95% CI 21–34). No stem fractures were noted within the follow-up period. Two patients had revision of the stem's one for infection and another for persistent pain.Positive mid-term clinical and radiological outcomes have been observed with this tapered, fluted, titanium, monobloc stem. Based on these results, this implant may be considered as a viable option in the majority of uncemented femoral revisions.

Long non-coding RNA H19 mediates osteogenic differentiation of bone marrow mesenchymal stem cells through the miR-29b-3p/DKK1 axis.

Single immobilization theory cannot fully account for the extensive bone loss observed after spinal cord injury (SCI). Bone marrow mesenchymal stem cells (BMSCs) are crucial in bone homeostasis because they possess self-renewal capabilities and various types of differentiation potential. This study aimed to explore the molecular mechanism of long non-coding RNA H19 in osteoporosis after SCI and provide new research directions for existing prevention strategies. We used small interfering RNA to knockdown H19 expression and regulated miR-29b-2p expression using miR-29b-3p mimetics and inhibitors. Western blotting, real-time fluorescence quantitative PCR, Alizarin red staining, alkaline phosphatase staining and double-luciferase reporter gene assays were used to assess gene expression, osteogenic ability and binding sites. lncRNA H19 was upregulated in BMSCs from the osteoporosis group, whereas miR-29b-3p was downregulated. We identified the binding sites between miR-29b-3p and lncRNAs H19 and DKK1. H19 knockdown promoted BMSCs' osteogenic differentiation, whereas miR-29b-3p inhibition attenuated this effect. We discovered potential binding sites for miR-29b-3p in lncRNAs H19 and DKK1. Our findings suggest that long non-coding RNA H19 mediates BMSCs' osteogenic differentiation in osteoporosis after SCI through the miR-29b-3p/DKK1 axis and by directly inhibiting the β-catenin signalling pathway.

Early versus delayed lower extremity amputations caused by firearm injury: A minimum 2-year follow-up.

High-energy casualties such as firearm injuries may result in extensive loss of soft tissue and bone in the lower extremities. Although the primary aim in these types of injuries is the preservation of the extremity, repeated surgical procedures for extremity salvage and subsequent restoration of function could have detrimental effects on the patient both physically and psychologically. The main aim of this study is to evaluate the physical and psychological outcomes of patients who underwent lower extremity amputation in the early period after a firearm injury compared with the results of patients who underwent amputation in the late period. We also evaluated the factors affecting the prognosis in patients undergoing late below-knee amputation (BKA). This retrospective study included patients who underwent BKA following a lower extremity injury caused by firearms between March 2016 and March 2022. Patients who underwent emergency BKA at the first center they were taken to immediately after the injury constituted the early amputation (EA) group. Patients who were transferred to our tertiary-level referral center for continuation of treatment after the first intervention at another center and later underwent BKA constituted the late amputation (LA) group. The patients were evaluated regarding age, gender, amputation side, presence of phantom limb pain (PLP), and post-traumatic stress disorder (PTSD). Information was available from hospital records for a total of 35 patients; 16 in the EA group and 19 in the LA group. All patients were male. The mean age at the time of injury was 25.5±5.3 years (range, 20-45 years), and the mean follow-up period was 37±17 months (range, 25-84 months). In the comparison of PLP experienced, the difference between the groups was statistically significant, with PLP experienced by 1 (10%) patient in the EA group and by 9 (90%) in the LA group (p=0.010). PTSD was diagnosed in 3 (23%) patients in the EA group and 10 (77%) patients in the LA group (p=0.039). Patients who underwent late BKA were found to be affected by PLP and PTSD at a higher rate. When deciding on extremity-preserving surgery for patients with severe open injuries to the lower extremity, it is crucial to consider the poor outcomes associated with late BKA. Patients should be thoroughly informed about these negative outcomes.

Oral Rehabilitation with Removable Partial Denture in a Patient with a Maxillary Defect Caused by a Firearm

The use of Removable Partial Denture (RPD) for the oral rehabilitation of patients who have suffered facial trauma and consequent tooth loss of several elements, serves as an alternative for replacing hard and soft tissues, as well as providing aesthetic and functional support. Facial trauma related to firearm injuries is a challenge for the surgical team, both in planning and during surgery, due to the destruction of anatomical planes and the multifragmentation of soft tissues and bone. The aim of this study is to report on the oral rehabilitation using removable prostheses of a patient who had suffered firearm trauma. Patient F. B. C., 30 years old, male, normosystemic, attended the postgraduate dental prosthesis clinic at Unichristus with the aim of rehabilitation after a firearm trauma. During the clinical assessment, a bone defect was observed in the anterior region of the maxilla, with the loss of several teeth and part of the alveolar bone structure. The plan was designed to rehabilitate the extensive bone loss caused by the trauma, through the use of an RPD, to promote the return of masticatory function, the patient's facial aesthetics and soft tissue support. The prosthesis was designed to use the remaining posterior teeth as a support and means of retention, aided by full coverage of the palate in order to bring more stability and comfort to the patient. At the end of the treatment, the aesthetic and functional aspects were restored, showing that this type of prosthesis is an alternative for rehabilitation in this type of case

Masquelet Technique: Visualization of Cement Spacer Utilizing Methylene Blue

Masquelet Technique: Visualization of Cement Spacer Utilizing Methylene Blue

Use of custom glenoid components for reverse total shoulder arthroplasty.

Our purpose was to evaluate a custom reverse total shoulder arthroplasty glenoid baseplate for severe glenoid deficiency, emphasizing the challenges with this approach, including short-term clinical and radiographic outcomes and complications. This was a single-institution, retrospective series of 29 patients between January 2017 and December 2022 for whom a custom glenoid component was created for extensive glenoid bone loss. Patients were evaluated preoperatively and at intervals for up to 5 years. All received preoperative physical examinations, plain radiographs, and computed tomography (CT). Intra- and postoperative complications are reported. Of 29 patients, delays resulted in only undergoing surgery, and in three of those, the implant did not match the glenoid. For those three, the time from CT scan to implantation averaged 7.6 months (range, 6.1-10.7 months), compared with 5.5 months (range, 2-8.6 months) for those whose implants fit. In patients with at least 2-year follow-up (n=9), no failures occurred. Significant improvements were observed in all patient-reported outcome measures in those nine patients (American Shoulder and Elbow Score, P<0.01; Simple Shoulder Test, P=0.02; Single Assessment Numeric Evaluation, P<0.01; Western Ontario Osteoarthritis of the Shoulder Index, P<0.01). Range of motion improved for forward flexion and abduction (P=0.03 for both) and internal rotation up the back (P=0.02). Pain and satisfaction also improved (P<0.01 for both). Prolonged time (>6 months) from CT scan to device implantation resulted in bone loss that rendered the implants unusable. Satisfactory short-term radiographic and clinical follow-up can be achieved with a well-fitting device. Level of evidence: III.

The Megaendoprosthesis in Revision Arthroplasty - a Cost-revenue Analysis in the aG-DRG System.

Megaendoprosthesis offer a viable treatment in complex revision arthroplasty cases with good functional outcome. In the context of a neoplastic indication, the diagnosis-related group (DRG) I95A is usually assigned with a relative weight of 4.906 (2021). In contrast, in revision arthroplasty, the appropriate DRG is assigned, depending on the joint replacement. The additional costs compared to the invoiced DRG are to be compensated by agreeing on hospital-specific individual fees. These complex revision arthroplasties set high technical and operative demands and are mainly performed in specialised departments. We conducted a cost-benefit analysis of the use of the megaendoprosthesis in revision cases in a specialised orthopaedic clinic, as a single centre study. The question we sought to answer was: Is cost recovery possible in the modified German DRG system (aG-DRG)?A retrospective single centre analysis of treatment costs was performed. From 2018 to 2020, 113 patients treated with a megaendoprosthesis reconstruction in a referral centre due to extensive bone loss after aseptic or septic revision of a hip or knee prosthesis were included in the study. Relevant case-related cost drivers of the aG-DRG matrix (including staff and material costs of the operating theatre area and the ward) were taken into account. The actual costs were determined according to the specifications of the calculation manual published by the German institute for the remuneration system in hospitals (InEK). For each case, the contribution margin was calculated by relating the hospital's internal costs to the corresponding cost pool of the aG-DRG matrix.According to the DRG system 2021, 17 different DRGs were used for billing - in 70% based on a patient clinical complexity level (PCCL) ≥4. Compared with the InEK calculation, there is a deficit of -2,901€ per case in the examined parameters. The costs of physicians show a shortfall in both the operating theatre and on the ward. Implant costs, which were supposed to be compensated by hospital-specific additional charges, show a hospital-specific shortage of -2,181€. When analysing the risk factors for cost recovery, only these showed a significant difference.Implantation of the megaendoprosthesis in revision arthroplasty is often the last option to preserve limb function. At present, despite a high degree of specialisation and process optimisation, this treatment cannot be provided cost-effectively even in tertiary care. The politically desired specialised department structure requires sufficient reimbursement for complex cases. The economic outcome of each treatment case is often unpredictable, however the surgeon is confronted with these cases and is expected to treat them. The high standard deviation indicates large differences in the cost/revenue situation of each individual case. Our results show for the first time a realistic cost analysis for megaprosthesis in revision arthroplasty and underline the importance of an adequate hospital-specific charge, individually agreed by the funding units. The calculation should include not only the implant costs, but also the increased staff costs (increased, complex planning effort, quality management, surgery time, etc.).

Anti-Siglec-15 Antibody Prevents Marked Bone Loss after Acute Spinal Cord Injury-Induced Immobilization in Rats.

Rapid and extensive sublesional bone loss after spinal cord injury (SCI) is a difficult medical problem that has been refractory to available interventions except the antiresorptive agent denosumab (DMAB). While DMAB has shown some efficacy in inhibiting bone loss, its concurrent inhibition of bone formation limits its use. Sialic acid-binding immunoglobulin-like lectin (Siglec)-15 is expressed on the cell surface of mature osteoclasts. Anti-Siglec-15 antibody (Ab) has been shown to inhibit osteoclast maturation and bone resorption while maintaining osteoblast activity, which is distinct from current antiresorptive agents that inhibit the activity of both osteoclasts and osteoblasts. The goal of the present study is to test a Siglec-15 Ab (NP159) as a new treatment option to prevent bone loss in an acute SCI model. To this end, 4-month-old male Wistar rats underwent complete spinal cord transection and were treated with either vehicle or NP159 at 20 mg/kg once every 2 weeks for 8 weeks. SCI results in significant decreases in bone mineral density (BMD, -18.7%), trabecular bone volume (-43.1%), trabecular connectivity (-59.7%), and bone stiffness (-76.3%) at the distal femur. Treatment with NP159 almost completely prevents the aforementioned deterioration of bone after SCI. Blood and histomorphometric analyses revealed that NP159 is able to greatly inhibit bone resorption while maintaining bone formation after acute SCI. In ex vivo cultures of bone marrow cells, NP159 reduces osteoclastogenesis while increasing osteoblastogenesis. In summary, treatment with NP159 almost fully prevents sublesional loss of BMD and metaphysis trabecular bone volume and preserves bone strength in a rat model of acute SCI. Because of its unique ability to reduce osteoclastogenesis and bone resorption while promoting osteoblastogenesis to maintain bone formation, Siglec-15 Ab may hold greater promise as a therapeutic agent, compared with the exclusively antiresorptive or anabolic agents that are currently used, in mitigating the striking bone loss that occurs after SCI or other conditions associated with severe immobilization. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Genetic variation influences the skeletal response to hindlimb unloading in the eight founder strains of the diversity outbred mouse population.

During disuse, mechanical unloading causes extensive bone loss, decreasing bone volume and strength. Variations in bone mass and risk of osteoporosis are influenced by genetics; however, it remains unclear how genetic variation affects the skeletal response to unloading. We previously found that genetic variation affects the musculoskeletal response to 3 weeks of immobilization in the 8 Jackson Laboratory J:DO founder strains: C57Bl/6J, A/J, 129S1/SvImJ, NOD/ShiLtJ, NZO/HlLtJ, CAST/EiJ, PWK/PhJ, and WSB/EiJ. Hindlimb unloading (HLU) is the best model for simulating local and systemic contributors of disuse and therefore may have a greater impact on bones than immobilization. We hypothesized that genetic variation would affect the response to HLU across the eight founder strains. Mice of each founder strain were placed in HLU for 3 weeks, and the femurs and tibias were analyzed. There were significant HLU and mouse strain interactions on body weight, femur trabecular BV/TV, and femur ultimate force. This indicates that unloading only caused significant catabolic effects in some mouse strains. C57BL/6 J mice were most affected by unloading while other strains were more protected. There were significant HLU and mouse strain interactions on gene expression of genes encoding bone metabolism genes in the tibia. This indicates that unloading only caused significant effects on bone metabolism genes in some mouse strains. Different mouse strains respond to HLU differently, and this can be explained by genetic differences. These results suggest the outbred J:DO mice will be a powerful model for examining the effects of genetics on the skeletal response to HLU.

Two-Year Outcomes of the Reverse Humeral Reconstruction Prosthesis.

Extensive proximal humeral bone loss in the setting of shoulder arthroplasty represents a difficult challenge for the treating surgeon. Achieving adequate fixation with standard humeral prostheses can be problematic. Allograft-prosthetic composites are a viable solution for this problem, however high rates of complications have been reported. Modular proximal humeral replacement systems are another potential solution, but there is a paucity of outcome data on these implants. This study reports the two-year minimum follow-up outcomes and complications of a single system reverse proximal humeral reconstruction prosthesis (RHRP) for patients with extensive proximal humeral bone loss. We retrospectively reviewed all patients with minimum two-year follow-up who underwent implantation of a RHRP for either 1) failed shoulder arthroplasty or 2) proximal humerus fracture with severe bone loss (Pharos 2 and 3) and/or sequelae thereof. Forty-four patients met inclusion criteria (average age 68.3 ± 13.1 years). The average follow-up was 36.2 ± 12.4 months. Demographic information, operative data, and complications were recorded. Pre- and postoperative range of motion (ROM), pain, and outcome scores were assessed and compared to the MCID and SCB for primary rTSA where available. Of the 44 RHRPs evaluated, 93% (n=39) had undergone prior surgery and 70% (n=30) were performed for failed arthroplasty. ROM improved significantly in abduction by 22° (P = .006) and forward elevation by 28° (P = .003). Average pain on a daily basis and pain at worst improved significantly, by 2.0 points (P < .001) and 2.7 points (P < .001), respectively. Mean SST score improved by 3.2 (P < .001), Constant score by 10.9 (P = .030), ASES score by 29.7 (P < .001), UCLA score by 10.6 (P < .001), and SPADI score by 37.4 (P < .001). A majority of patients achieved the MCID for all outcome measures assessed (56-81%). The SCB was exceeded by half of patients for forward elevation and the Constant score (50%), and exceeded by the majority of patients for the ASES score (58%) and UCLA score (58%). The complication rate was 28%; the most common complication was dislocation requiring closed reduction. Notably, there were no occurrences of humeral loosening requiring revision surgery. This data demonstrates that the RHRP resulted in significant improvements in ROM, pain, and PROMs, without the risk of early humeral component loosening. RHRP represents another potential solution for shoulder arthroplasty surgeons when addressing extensive proximal humerus bone loss.