Residual Bone Research Articles

Connective Tissue Graft May Compensate for Residual Bone Defect of the Implant in the Esthetic Zone: A Case Report with 7-year Follow-up

The present case report aimed to demonstrate the case using a connective tissue graft (CTG) to compensate for a residual defect after guided bone regeneration (GBR) in the anterior maxillary area. An extensive number of studies have reported successful outcomes of horizontal bone augmentation, but it was also demonstrated that a complete resolution of the defect may not be achieved in all cases. In the present case report, the patient underwent implant placement simultaneously with GBR at the anterior maxillary area. After 4 months, partial regeneration of the initial defect was observed. To compensate for such residual defect, a CTG was applied. Other expectations by the CTG were to enhance tissue volume and phenotype. The final prosthesis was delivered after 3 months. Up to 7 years, favorable radiographic and clinical situations were observed. In conclusion, a CTG may compensate for residual bone defect of the implant in the esthetic zone.

Evaluation of thin-threaded implants primary stability in type IV bone right after maxillary sinus floor elevation: A human cadaver study.

The bone-implant interface plays a crucial role in obtaining sufficient primary stability for dental implants in weak bone supports. The aim of this human cadaver study was to evaluate the primary stability of new thin-threaded implants when placed in type IV bone right after maxillary sinus floor elevation. The study followed the CACTUS (ChAracteristics of Cadaver Training and sUrgical Studies) guidelines. Twenty-four edentulous maxillary posterior zones with type IV bone and a residual bone height of 4mm were selected using computed tomography scans. First, an osteotome sinus floor elevation was performed (C.M.C Tech, IBS IMPLANT, Daejeon, South Korea). Implants with thin threads (MagiCore, IBS IMPLANT, Daejeon, South Korea) were placed simultaneously. Samples were divided into two groups: Group 1 (G1): 11mm-long implants with an elevation of 8mm; Group 2 (G2): 7mm-long implants with an elevation of 4mm. Primary stability was assessed using resonance frequency analysis (RFA). The average primary stability values in the mesiodistal (MD) direction were 45.67±3.09 Implant Stability Quotient (ISQ) for G1 and 38.76±16.94 ISQ for G2, and in the buccolingual direction were 43.33±13.23 ISQ for G1 and 38.47±16.14 ISQ for G2. The primary stability of the thin-threaded implants was compatible with clinical osseointegration in sinus sites with limited bone contact area in both experimental situations. Clinical studies are needed to confirm these encouraging results.

Residual cholesteatoma of the temporal bone in a patient with granulomatosis with polyangiitis

A case of residual temporal bone cholesteatoma in a patient with granulomatosis with polyangiitis (Wegener) (GPA) is presented. At the onset of the disease, the patient developed a symptom complex, which included, along with sinonasal manifestations, left-sided purulent otitis media, refractory to traditional therapy. A separate atticoanthrotomy on the left temporal bone, performed in the active phase, before the diagnosis of vasculitis, did not lead to a clinical improvement in the condition of the middle ear. Despite the subsequent implementation of adequate immunosuppressive therapy and drug remission of GPA, the continuously recurrent course of purulent otitis media of the operated ear contributed to the development of residual cholesteatoma of the temporal bone with the spread of the process to surrounding structures. The presence of cholesteatoma was confirmed by MRI of the temporal bones in the non-EPI DWI mode. During the period of drug remission of GPA, repeated sanitizing surgery was performed on the middle ear with tympanoplasty and obliteration of the parathympanic spaces, which made it possible to achieve remission of purulent otitis media. The development of residual middle ear cholesteatoma in a patient with GPA could be due to the untimely initial diagnosis, the late onset of specific immunotherapy, the rapidly progressive and recurrent nature of the course of the disease, and surgical treatment in the phase of high disease activity. The insufficient volume of primary surgical treatment contributed to the formation of laced cavities and the development of residual cholesteatoma of the temporal bone. The use of MRI in the non-EPI DWI mode for diagnosis made it possible to identify the development of cholesteatoma of the left temporal bone in a patient with GPA and track the results of surgical treatment in the postoperative period. The non-EPI DWI MRI method proved effective both for detecting temporal bone cholesteatoma and tracking changes in the postoperative period of a patient with GPA. Tympanoplasty with surgical obliteration of the parathympanic spaces allowed to stop the inflammation of the middle ear in a patient with a systemic autoimmune disease.

Morphological remodeling of the repaired sigmoid sinus bone wall in patients with pulsatile tinnitus after successful surgical reconstruction: an ultra-high-resolution CT study.

Sigmoid sinus wall reconstruction (SSWR) is an effective treatment for pulsatile tinnitus (PT). However, follow-up postoperative imaging manifestations have not been extensively reported. To evaluate the morphological changes in patients with PT after successful SSWR using ultra-high-resolution computed tomography (U-HRCT). Data were retrospectively analyzed from 10 patients with PT who underwent successful SSWR primarily with autologous bone powder. U-HRCT scans were performed within 3 days of surgery and repeated 6 months later. The integrity, relative density, extent, and shape of the repaired wall were analyzed. The chi-square test was used to compare the categorical variables and the Phi (φ) coefficient was used to represent the magnitude of the correlation. Among the 10 patients with PT, 1 (10%) achieved complete coverage of the defect with the residual bone, 8 (80%) had partial coverage, and 1 (10%) showed complete separation. A gap between the repaired wall and residual bone in the initial U-HRCT was linked to incomplete defect coverage in the subsequent U-HRCT scan (P < 0.001, φ = 0.903). The repaired wall shrank from the periphery to the center and the density increased. The repaired wall compressed into the sigmoid sinus retracts over time, reshaping into a naturally curved sigmoid sinus sulcus. Morphological remodeling is a typical characteristic of the repaired sigmoid sinus wall in patients with PT. Short-term incomplete repair may imply incomplete coverage of the defect in the future, but this is not correlated with recurrence.

Biomechanical analysis of different techniques for residual bone defect from tibial plateau bone cyst in total knee arthroplasty.

In patients with tibial plateau bone cysts undergoing total knee arthroplasty (TKA), bone defects commonly occur following tibial plateau resection. Current strategies for addressing these defects include bone grafting, bone cement filling, and the cement-screw technique. However, there remains no consensus on the optimal approach to achieve the best surgical outcomes. This study aims to evaluate the most effective repair method for residual bone defects following tibial plateau bone cyst repair during TKA from a biomechanical perspective. The treatment options for tibial plateau bone defects were classified into four categories: no treatment, cancellous bone filling, bone cement filling, and the cement-screw technique. Finite-element analysis (FEA) was employed to evaluate stress distribution and displacement across the models for each treatment group. In addition, static compression mechanical tests were used to assess the displacement of the models within each group. FEA results indicate that when employing the cement-screw technique to repair tibial plateau bone defects, the maximum stress on the prosthesis and the cement below the prosthesis is minimized, while the maximum stress on the cancellous bone is maximized. And the displacement of each component is minimized. Biomechanical tests results further demonstrate that the displacement of the model is minimized when utilizing the cement-screw technique for tibial plateau bone defects. Using cement-screw technique in treating residual tibial bone defects due to bone cysts in TKA offers optimal biomechanical advantages.

Crestal approach for maxillary sinus augmentation in individuals with limited alveolar bone height: An observational study.

In cases where the bone presence is <4 mm, the lateral approach is typically the first approach considered. Nevertheless, for patients who prefer minimally invasive procedures or wish to reduce postoperative discomfort, the crestal approach is a viable option. The objective of this study was to investigate the potential of crestal sinus augmentation for achieving adequate bone in individuals with residual bone measuring <3 mm. The study comprised 11 participants (63.6 ± 10.9 years of age) who were treated at Seoul St. Mary's Hospital between 2021 and 2023 and received crestal approach sinus augmentation due to insufficient bone density of <3 mm using the crestal approach kit. Pre-augmentation and post-augmentation cone-beam computed tomographic images were analyzed using the imaging software to measure vertical bone height, bucco-palatal width, and mesio-distal width. Before the intervention, the height of the vertical bone was 2.1 ± 0.5 mm, while the width from buccal to palatal was 10.6 ± 2.9 mm, and the width from mesial to distal was 9.9 ± 1.2 mm. Following the intervention, these measurements increased to 8.8 ± 0.9 mm, 12.2 ± 2.2 mm, and 10.2 ± 1.2 mm, respectively. The change in height of the vertical bone was 6.7 ± 1.0 mm, in bucco-palatal width was 1.6 ± 1.4 mm, and in mesio-distal width was 0.3 ± 0.4 mm. The results revealed a significant rise in the height of the vertical bone and bucco-palatal width. Crestal sinus augmentation has been demonstrated to be a highly effective approach for achieving an adequate quantity of bone in patients with residual bone <3 mm. Nonetheless, further observation is required to evaluate the long-term prognosis of the procedures.

Applying 3D-Printed Porous Ti6Al4V Prostheses to Repair Osteomyelitis-Induced Partial Bone Defects of Lower Limbs: Finite Element Analysis and Clinical Outcomes.

The clinical management of partial bone defects in lower limbs, particularly those resulting from osteomyelitis, remains a significant challenge. This study aimed to systematically evaluate the effectiveness of 3D-printed porous Ti6Al4V prostheses in addressing osteomyelitis-induced partial bone defects. We established a comprehensive protocol for utilizing 3D-printed prostheses for bone defect repair, encompassing 3D simulation of prosthesis implantation and internal fixation, finite element analysis (FEA), and clinical implementation. Mimics software facilitated simulation of fixation patterns and screw lengths. FEA modeled bone defects in the distal metaphyseal femur and distal diaphyseal tibia to assess changes in stress conduction pre- and post-prosthesis implantation. The clinical study involved eight patients (average age: 56.3 years) with an average defect length of 14.9 cm. Postoperative outcomes were evaluated using X-rays and the Lower Extremity Functional Scale (LEFS). FEA demonstrated that the implanted prostheses effectively shared stress and reduced the load on residual bone in both models, thus lowering the risk of fractures under external forces. The average follow-up period was 24.5 months, with patients initiating weight-bearing activities on average 7.8 days post-surgery. Serial postoperative X-rays demonstrated long-term stability of the prostheses, with progressive bone regeneration around and integration with the prostheses. While two patients experienced infection recurrence requiring prosthesis removal and debridement, the remaining six showed significant improvement in LEFS scores, increasing from 31.5 preoperatively to 61.0 at the last follow-up. 3D-printed porous Ti6Al4V prostheses effectively restore anatomical integrity and optimize stress conduction in lower limbs, resulting in substantial functional recovery. This innovative approach shows promise for wider clinical adoption and warrants further investigation in medical practice.

Intraoral Approach for Dental Implant Placement in Pneumatized Maxillary Sinuses with Postoperative Maxillary Cysts: A Report of Two Cases.

A postoperative maxillary cyst (POMC) is a delayed complication of the original Caldwell Luc operation, which was once widely performed to treat chronic rhinosinusitis. Two patients who had previously undergone Caldwell Luc operations desired dental implant treatment. In both cases, preoperative conebeam computed tomography (CBCT) revealed a POMC occupying the entire maxillary sinus on the side where the implants were to be placed. The residual bone height was 3-4 mm. Furthermore, the sinuses were divided into compartments by septum-like structures. An intraoral approach was applied for POMC enucleation and implant placement. The implants were placed with sinus floor penetration due to the small residual bone height. No bone substitute material was grafted in the sinus. Post-operative healing was uneventful. All implants were successfully osseointegrated and performed well (4 and 5 years for each patient). No sino-nasal complications were reported. Follow-up CBCTs showed that the exposed implant parts were covered by newly formed bone. The intraoral approach is a feasible option for implant placement in a pneumatized maxillary sinus with POMC.

Staged revision of the infected knee arthroplasty and endoprosthesis.

Periprosthetic joint infection (PJI) is a challenging complication of any arthroplasty procedure. We reviewed our use of static antibiotic-loaded cement spacers (ABLCSs) for staged management of PJI where segmental bone loss, ligamentous instability, or soft-tissue defects necessitate a static construct. We reviewed factors contributing to their failure and techniques to avoid these complications when using ABLCSs in this context. A retrospective analysis was conducted of 94 patients undergoing first-stage revision of an infected knee prosthesis between September 2007 and January 2020 at a single institution. Radiographs and clinical records were used to assess and classify the incidence and causes of static spacer failure. Of the 94 cases, there were 19 primary total knee arthroplasties (TKAs), ten revision TKAs (varus-valgus constraint), 20 hinged TKAs, one arthrodesis (nail), one failed spacer (performed elsewhere), 21 distal femoral endoprosthetic arthroplasties, and 22 proximal tibial arthroplasties. A total of 35/94 patients (37.2%) had spacer-related complications, of which 26/35 complications (74.3%) were because of mechanical failure of the spacer construct, while 9/35 (25.7%) were due to recurrence of infection. Risk factors for internal failure were a construct where the total intramedullary spacer length was less than twice the length of the central osseous defect (p = 0.009), where proximal or distal intraosseous spacer contact was < 10%, and after tibial tubercle osteotomy (p = 0.005). The incidence of spacer complications significantly increased the time to second stage: mean 157 days (42 to 458) in those without complications versus 227 days (11 to 528) with complications (p = 0.014). The failure rate of static antibiotic-loaded cement spacers is much higher than anticipated. Complications of the spacer significantly increased the time to second-stage revision. The risk of mechanical failure is significantly increased if the spacer is less than double the size of the segmental defect, or if inadequate reinforcement is inserted into the residual bone. These findings serve as a guide for surgeons to avoid mechanical complications with static spacers.

Reamer-scraping and implant-pushing technique for transcrestal sinus floor elevation.

Transcrestal maxillary sinus floor elevation is an effective method to solve the problem of insufficient bone height in the posterior maxillary region. However, current methods, such as osteotome sinus floor elevation, cushioned grind-out technique, Smart Drill technique, etc., require specialized surgical tool boxes. In this article, we introduce a new method of transcrestal maxillary sinus elevation that uses built-in reamers of various implant systems to scrap residual bone at the sinus floor and uses the implant to push the sinus membrane during implant placement. This technique is easy to operate and time saving and has a low rate of sinus membrane perforation. After a one-year follow-up observation of 146 people and 175 implants, the endo-sinus bone gains were 5.00 (4.70, 5.30) mm and 2.10 (1.40, 2.70) mm in the group of 3 mm≤residual bone height (RBH)<5 mm and the group of 5 mm≤RBH<8 mm, respectively, which can meet the clinical requirements of implant stability. This technique is suitable in generalizing dental implantation.

Risk Factors for Implant Failure Following Transcrestal Sinus-Floor Elevation: A Case Report and Literature Review.

Although transcrestal sinus floor elevation (TSFE) is widely used for cases of insufficient residual bone height in the posterior maxilla, few studies focus on the risk factors of early implant failure associated with TSFE procedures. This study aimed to identify and summarize the possible risk factors of implant failure associated with TSFE to ensure a more predictable implant survival rate using TSFE. We report the treatment of a patient with implant failure following TSFE and discuss this case's possible associated risk factors. A standard implant with a diameter of 4.8 mm and length of 10 mm was used after the TSFE procedure. Implant loosening was suddenly observed 6 weeks after the initial surgery. Factors that could result in early implant failure included patient-related risk factors, anatomical factors of the operational area, and operation- and implant-related factors. Within the current study's limitations, the graft material particles between the implant surface and socket could be considered a direct risk factor resulting in implant failure. Therefore, more attention should be paid to socket cleaning during the TSFE procedure, and loose particulate grafting materials should be discouraged. Another significant consideration for implant loss is the possibility of fractures in the buccal or palatal cortical plates during the site preparation and implant insertion. Thus, these factors should be studied further and receive more clinical attention.

Osseodensification technique in crestal maxillary sinus elevation-A narrative review.

Osseodensification is a novel approach that has significantly advanced the field of implant dentistry, particularly in the context of transcrestal maxillary sinus floor elevation. This technique involves the use of specially designed burs that compact and densify bone along the osteotomy walls, thereby enhancing implant primary stability and facilitating osseointegration in low-density bone. This article reviews the historical evolution of implant site preparation, and the biomechanical, histological, and clinical evidence of osseodensification with a special focus on its application in sinus floor augmentation. The integration of this technique into contemporary practice represents a paradigm shift, offering a minimally invasive and efficient solution for addressing the challenges of posterior maxilla, with improved patient-reported outcomes and low complication rate. Three different protocols for sinus lift and implant placement using osseodensification burs are proposed based on available literature, and risk factors for Schneiderian membrane perforation based on residual bone height are discussed, along with implant-related outcomes and patient-reported outcome measures. The potential for osseodensification to become a standard practice in sinus floor augmentation is emphasized, highlighting key aspects such as surgical protocol and patient selection.

Characteristics and impacts of dental implant displacement into the maxillary sinus

Background/purposeDental implants displaced into the maxillary sinus are considered to require surgical removal as the treatment of choice. However, displaced implants have been reported to affect the maxillary sinus in different ways. This study aimed to evaluate characteristics and impacts of dental implant displacement into the maxillary sinus. Materials and methodsFourteen sinuses with displaced implants into the maxillary sinus were included. Demographic data and radiographic images were analyzed, with a focus on the impact of various factors such as demographic data, timing of displacement, duration of retention, and residual bone height on maxillary sinus opacification and sinus wall thickness. ResultsImplants were displaced during or in the early stage after implant placement in 9 cases and after functional loading in 5 cases. Radiographic evaluations showed higher sinus opacification score (P = 0.019) and increased wall thickness (P = 0.198) in cases with displacement after functional loading, although the difference in wall thickness was not statistically significant. When the duration of implant retention in the sinus was longer, higher sinus opacification and sinus wall thickness were observed, although the differences were not statistically significant. Univariate regression analysis demonstrated that the timing of displacement significantly influenced maxillary sinus opacification (P = 0.013) and sinus wall thickness (P = 0.013). For all cases, evidence of site preparation and the use of short implants were not observed. ConclusionThis study suggests that adequate pre-implant site preparation and timely intervention are essential to prevent and manage implant displacement into the maxillary sinus.

Arthroscopic removal of the fragmented medial coronoid process in dogs - Evaluation of treatment results with special reference to postoperative computed tomography and residual particles

The aim of this study was to assess the treatment success of dogs with medial coronoid disease (here: Fragmented Coronoid Process [FCP]) following arthroscopically performed subtotal coronoidectomy by the use of subjective and objective gait analysis and the evaluation of osteoarthritis progression in addition to their correlation with the findings from postoperative computed tomography. In particular, the clinical relevance of residual particles remaining postoperatively was to be evaluated. Thirty elbows from 24 dogs of different breeds were examined clinically, orthopedically, using gait analysis as well as radiographically at least 6 months after unilateral or bilateral subtotal coronoidectomy. The results were compared with the preoperative findings of the corresponding examinations and postoperative computed tomography. 79.2% (19/24) of the patients improved by at least one degree of lameness in the orthopedic examination, 66.7% (16/24) were free of lameness. 60% (18/30 joints) showed an increase in the degree of arthrosis. Postoperative computed tomography revealed small residual bone particles (<1 mm) in the joint space or soft tissue in 56.7% (17/30) of the joints. No significant association was evident between residual lameness and residual particles remaining within the joint postoperatively. An association between persistent lameness and progression of arthrosis was also not be demonstrable. No evidence was apparent supporting a link between residues of small bone particles after arthroscopic subtotal coronoidectomy and postoperative lameness. The progression of osteoarthritis could not be interrupted despite the surgical intervention. When small residual particles (<1 mm) remain after subtotal coronoidectomy, these do not appear to have any influence on the clinical outcome.

When the Going Gets Tough: A Review of Total Hip Arthroplasty in Patients with Ipsilateral Above- and Below-Knee Amputation.

Life expectancy and overall function of amputated patients have improved significantly over the last few decades; for this reason, amputees are more exposed to primary or secondary degenerative disease of the hip, requiring total hip arthroplasty (THA) surgery. However, during training, not all the surgeons acquire adequate skills to manage these patients, and only a few studies and case reports describe technical pearls and outcomes of THA in patients with ipsilateral lower limb amputation, either above or below the knee. The objective of this narrative review is to present current evidence and surgical tips for performing THA in ipsilateral amputated patients, with a focus on the differences between patients with above- (AKA) and below-knee amputation (BKA). We reviewed manuscripts in major scientific databases, cross-referencing to retrieve adjunctive manuscripts, and summarized all relevant cases. We found 17 manuscripts, spanning 70 years of literature, collecting a total of 39 patients who underwent THA on an ipsilateral amputated limb: 13 AKA, 23 BKA, and 3 through-knee-amputation (TKA). The cohort primarily consists of patients with post-traumatic hip arthritis, often associated with sequelae such as fractures to other bones, soft tissue compromise and heterotopic calcifications. Managing with amputated patients requires careful planning, which includes the study of the residual bone, muscle anatomy, and the level of femoral amputation, as these factors present significant surgical challenges, especially in patients without a knee joint. In dealing with the post-traumatic and multi-comorbidity patients, rehabilitation goals should be considered prior to surgery and should drive the surgical strategy. We found that BKA patients typically have high functional demands, necessitating precise positioning of the components and an aggressive post-operative physiotherapy regimen to avoid unsatisfactory outcomes. AKA patients, on the other hand, often present with altered anatomy, and typically require more surgical instruments and expertise to achieve intraoperative dislocation of the hip joint.

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review.

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Patient and implant-related risk factors for implant failure of one-stage lateral sinus floor elevation: A 2- to 10-year retrospective study.

This retrospective study aimed to evaluate the early and late implant failure rates of one-stage lateral sinus floor elevation (LSFE)and to identify the patient and implant-related risk factors associated with these failures. All patients treated with one-stage LSFE from January 2014 to December 2021 were evaluated for inclusion. A total of 618 patients with 936 implants met the inclusion criteria. Clinical and radiographic information about patient and implants was collected. Univariate and multivariate Cox proportional hazards frailty regression models were performed to identify risk factors for early and late implant failure. The cumulative implant survival rate was 95.62% (95% CI 93.90%-97.68%), with 16 early implant failures and 25 late implant failures. The Cox analysis indicated that ≤3 mm residual bone height (RBH) was associated with a higher early failure rate. For late implant failure, smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors. Narrow sinus ostium, long infundibulum, and flat thickening of Schneiderian membrane might be non-independent risk factors for late implant failure. No significance was found in other variables, including age, periodontitis history, implant characteristics (position, diameter, length, protrusion length, marginal bone loss), surgeon experience, healing time, opposing dentition, and prosthesis. One-stage LSFE is a predictable treatment for patients with atrophic maxilla. ≤3 mm RBH increased the risk of early implant failure, while smoking habit, ≤3 mm RBH, and certain implant brand were independent risk factors for late implant failure.

A Registry Study on Acetabular Revisions Using Jumbo Cups: Do We Really Need a More Complex Revision Strategy?

BackgroundThe increasing global performance of total hip arthroplasty (THA) has led to a rise in revision surgeries, primarily due to cup failure, with aseptic loosening and periprosthetic infection being common causes. Various techniques and implants, including jumbo cups (JCs), manage residual bone loss post-cup removal, facilitating enhanced surface area for improved host bone contact, and osteointegration. The purpose of the study was to determine the outcomes of acetabular revision arthroplasty using JC implants over a 20-year follow-up period by reporting overall survivorships, complications leading to re-revision, and surgical strategies in re-revision. MethodsA cohort study based on a large regional registry was conducted, examining revision THA surgeries utilizing JCs between 2000 and 2020. The study included all the revision acetabular procedures performed with cementless JCs, identified with a diameter ≥ 62 millimeters (mm) in women or ≥ 66 mm in men. All iliac fixation cups were excluded. Data on demographics, revision surgery indications, components, fixation types, causes of failure, and reintervention strategies were collected and analyzed. A total of 541 JCs implanted from January 2000 to December 2020 were evaluated. The most common revision indications were “cup aseptic loosening” (54.5%) and “total aseptic loosening,” which included both the cup and stem (32%). ResultsThe JC survival rates were 92.5% at 5 years, 85.8% at 10 years, and 81.5% at 15 years. Among the 70 failures, the main causes were “cup aseptic loosening” (40%), “total aseptic loosening” (17.1%), and “septic loosening” (12.8%). Revisions primarily involved acetabular cup revision surgery (54 cases), component explantation (11 cases), or insert or head revision (five cases). ConclusionsThis registry-based study of JCs in revision THA demonstrates excellent 15-year survival rates and acceptable failure rates. It supports JCs as a viable option, offering relative surgical simplicity compared to alternatives like antiprotrusion cages, bone grafts, and augments.

Comprehensive sinus contour classification and its characteristics from radiographic examination: a cross-sectional study

ObjectiveThe aim of this study was to propose a comprehensive maxillary sinus (MS) contour classification system based on the evaluation of anatomical characteristics from cone beam computed tomography (CBCT) examination and investigate the relationship between sinus contours and sinus floor elevation (SFE).MethodsA total of 283 CBCT scans from patients who had single tooth loss in the posterior maxilla and underwent SFE were analyzed. The MS was classified at each tooth position. For buccal-palatal evaluation, the classification from Type A to E was narrow-taper, taper, ovoid, square, and irregular, respectively. For mesial-distal evaluation, the classification from Type 1 to 4 was flat, slope, concave, and septa, respectively. The major anatomical parameters evaluated were (1) residual bone height (RBH), (2) sinus width (SW), (3) maxillary sinus angle (MSA), (4) buccal dip angle (BDA), (5) palatonasal recess (PNR), and (6) sinus depth.ResultsEleven groups of MS contour were classified after detailed calculation. Differences in the RBH, MSA, BDA, and SW among different groups were statistically significant. The narrow-taper and slope MS (A2) group had the highest RBH (8.66 ± 0.77 mm), largest BDA (79.9° ± 3.18°), smallest MSA (19.8° ± 2.01°), and narrowest SW (6.30 ± 1.23 mm). The lowest RBH was in the square and concave sinus (D3) group (5.11 ± 2.70 mm). The ovoid and concave sinus (C3) group had the smallest BDA (50.64 ± 8.73 mm) and largest MSA (74.11° ± 11.52°). The square and flat MS (D1) group had the widest SW (19.13 ± 3.69 mm). A strongly significant positive correlation was observed between the SW and MSA (r = 0.67) and a strongly negative correlation between the SW and BDA (r = − 0.65). The prevalence of PNR (mean angle: 104.06° ± 16.83°, mean height: 14.72 ± 11.78 mm) was 38% and frequently observed in the ovoid and slope MS (C2) group.ConclusionDespite certain characteristics at different tooth sites, the same tooth position was categorized differently using different classification systems, indicating large anatomical variations in the MS. The classification system proposed herein allows for classification based on general characteristics at a single tooth site, aiming to help surgeons in improving presurgical evaluation.

Feasibility of predicting changes in gait biomechanics following muscle strength perturbations using optimal control in patients with transfemoral amputation

Bone-anchored limbs (BALs) are socket prosthesis alternatives, directly fixing to residual bone via osseointegrated implant. There is a need to quantify multi-level effects of rehabilitation for transfemoral BAL users (i.e. changes in joint loading and movement patterns). Our primary objective was determining feasibility of using optimal control to predict gait biomechanics compared to ground-truth experimental data from transfemoral BAL users. A secondary objective was examining biomechanical effects from estimated changes in hip abductor muscle strength. We developed and validated a workflow for predicting gait biomechanics in four transfemoral BAL users and investigated the biomechanical effects of altered hip abductor strengths.