Total hip arthroplasty in patients under 50 years old: Does cementless fixation have better results? / Reemplazo total de cadera en pacientes menores de 50 años: ¿tiene la fijación no cementada mejores resultados?

BACKGROUND: Cementless fixation for hip arthroplasties has increased in the last decades, particularly in younger patients. The purpose of this study was to compare the long-term results three different types of fixations in patients under 50years old. METHODS: Cemented, hybrid and cementless fixations were assessed in patients under 50years old with a minimum follow-up of 8years. Loosening, demarcation, complications, and prosthesis survival were assessed. Functional analysis was performed with the modified Harris Hip Score and Visual analogue scale was collected. RESULTS: Final series consisted in 222 patients. Significant improvement was observed regarding mHHS and VAS score in each group. We observed statistically significant difference regarding demarcation between the groups (P<.001). The higher rate of acetabular and femoral stem loosening was observed in the cemented (20.0%) and hybrid (18.9%) group. The lowest prosthesis survival rate after 16 years was observed in hybrid group (P<.001). CONCLUSION: Total hip replacement has good long-term clinical and functional outcomes. The lowest rate of prosthesis survival was observed in hybrid group with 84.2% after 16years.

Zirconia-ceramic versus metal-ceramic implant-supported multiunit fixed dental prostheses: A systematic review and meta-analysis.

Implant-supported prostheses could serve as a reliable restorative option for partial edentulism. Various restorative materials have been utilized in fabricating these prostheses, impacting both esthetics and peri-implant health. The present systematic review aimed to assess the survival rate and mechanical complications of zirconia ceramic compared to metal-ceramic implant-supported multiunit fixed dental prostheses (FDPs). We conducted searches in online databases such as MEDLINE (PubMed), Scopus, and Cochrane up until December 2022. A risk-of-bias assessment was done for all the included studies. Data extraction was performed based on the following parameters: author, year, study design, number of implants, abutment material, age range, observation period, incidence of mechanical complications, and survival rate. This systematic review included six studies (four randomized controlled trials and two retrospective studies). The meta-analysis significantly favored metal-ceramic restorations regarding mechanical complications with a risk ratio (RR) value of 1.64 and P = 0.001. Meta-analysis showed no difference in metal-ceramic FDPs in prostheses survival rate (P = 0.63; RR: 1.27, 95% confidence interval: 0.52-3.37; heterogeneity: P = 0.65; I2: 0%). While metal-ceramic multiunit implant-supported prostheses exhibited fewer mechanical complications compared to zirconia-ceramic prostheses, there was no significant difference in terms of prosthesis survival rate between the two. Hence, both treatments appear to be viable options for long-term implant-supported prostheses.

Mechanical indications for inflatable penile prosthesis revision: analysis and implications for revision surgery.

BACKGROUND: Despite technical advancements, inflatable penile prostheses (IPPs) are inherently at risk of mechanical failure given their nature as hydraulic devices. AIM: To characterize IPP component failure location at the time of device revision and stratify by manufacturer: American Medical Systems (Boston Scientific [BSCI]) and Coloplast (CP). METHODS: A retrospective review of penile prosthesis cases from July 2007 to May 2022 was conducted, identifying men who underwent revision surgery. Cases were excluded if documentation did not denote the cause of failure or the manufacturer. Mechanical indications for surgery were categorized by location (eg, tubing, cylinder, or reservoir leak; pump malfunction). Nonmechanical revisions were excluded (component herniation, erosion, or crossover). Categorical variables were assessed with Fisher exact or chi-square analysis; Student t-test and Mann-Whitney U test were used for continuous variables. OUTCOMES: Primary outcomes included specific location of IPP mechanical failure among BSCI and CP devices and time to mechanical failure. RESULTS: We identified 276 revision procedures, 68 of which met inclusion criteria (46 BSCI and 22 CP). Revised CP devices were longer than BSCI devices (median cylinder length, 20 vs 18 cm; P < .001). Log-rank analysis revealed a similar time to mechanical failure between brands (P = .096). CP devices failed most often due to tubing fracture (19/22, 83%). BSCI devices had no predominant site of failure. Between manufacturers, tubing failure was more common in CP devices (19/22 vs 15/46 for BSCI, P < .001), while cylinder failure was more common among BSCI devices (10/46 vs 0/22 for CP, P = .026). CLINICAL IMPLICATIONS: The distribution of mechanical failure is significantly different between BSCI and CP devices; this has implications regarding the approach to revision surgery. STRENGTHS AND LIMITATIONS: This is the first study to directly compare when and where mechanical failure occurs in IPPs and to compare the 2 main manufacturers head-to-head. This study would be strengthened by being repeated in a multi-institutional fashion to provide more robust and objective evaluation. CONCLUSION: CP devices commonly failed at the tubing and rarely elsewhere, while BSCI devices showed no predominant failure site; these findings may inform decision making regarding revision surgery.

Constrained metal-on-metal hip arthroplasty: ever heard of a 50-year survival story?

BACKGROUND: The history of total hip arthroplasty dates back to the first half of the twentieth century. Data on hip endoprostheses implanted during the 1960s and 1970s suggest widely varying survival rates of the prosthesis. CASE: A case of a patient who underwent total hip arthroplasty in 1972 using a Sivash prosthesis, developed in 1956 in the former Soviet Union, is presented in this article. The prosthesis has remained unrevised in the patient's body for 50 years and he continues to be widely free of implant-related symptoms. Despite the constrained metal-on-metal design of the implant, which can lead to adverse reactions to metal debris, no elevated systemic metal ion levels were detected. CONCLUSION: The likelihood of encountering patients with prosthesis survival beyond 50 years is still rare. Nevertheless, changing demographics and the steadily improving designs and materials of hip endoprostheses may likely result in such cases.

Survival rates, patient satisfaction, and prosthetic complications of implant fixed complete dental prostheses: a 12-month prospective study.

PURPOSE: To determine the survival rate, incidence of prosthetic complications, and patient satisfaction of implant fixed complete dental prostheses (IFCDPs) after a mean observation period of 1.4 years. MATERIALS AND METHODS: Twenty-eight (28) eligible participants were recruited according to specific inclusion and exclusion criteria. The definitive metal-acrylic resin IFCDPs consisted of titanium bars veneered with acrylic resin and acrylic denture teeth. Prosthodontic complications, divided into major and minor, were monitored. Parameters such as gender, jaw location, bruxism, and occlusal scheme were evaluated. Moreover, a questionnaire was administered throughout the study to assess patient satisfaction. Poisson regression as well as repeated measures ANOVA were used for statistical analysis. RESULTS: Fourteen (14) males and 14 females were enrolled and followed-up at 3, 6, and 12 months. All IFCDPs survived (100% survival rate). The most frequent minor complication was the loss of material used to close the screw access hole (20% out of total complications). The most frequent major complication was chipping of the acrylic denture teeth (77.14% out of total complications). Gender (p = 0.008) and bruxism (p = 0.030) were significant predictors for the total major complications (major wear and major chipping) while occlusal scheme was a significant predictor for major chipping events (p = 0.030). CONCLUSIONS: While IFCDPs demonstrated high prosthetic survival rates, they also exhibited a high number of chipping events of the acrylic veneering material, especially in males, bruxers, and individuals with canine guidance occlusion. However, the occurrence of these prosthetic complications did not negatively affect patient satisfaction.

Fiber-reinforced composite partial fixed dental prostheses supported by short or extra-short implants: A 10 year retrospective study.

INTRODUCTION: This study evaluated the 10-year survival and success of partial fixed dental prostheses (P-FDPs) fabricated with a milled fiber-reinforced composite (FRC) framework, supported by short or extra-short implants. METHODS: Patients restored with FRC P-FDPs supported by short or extra-short implants were included in this retrospective study. Kaplan-Meier analysis was used to calculate the survival and success rates of the prostheses. Univariate and multivariate Cox regression models, clustered to adjust for multiple implants and prostheses being placed in the same patient, were used to correlate changes in peri-implant bone levels with patient, implant, and prosthesis-related covariates. RESULTS: This study followed 121 FRC P-FDPs supported by 261 implants, placed in 96 patients. At 118 months in function, the P-FDP survival rate was 95.9% (95% CI: 87.5%-98.7%), and the success rate was 89.8% (95%CI: 80.4%-94.8%). Differences in prosthesis span length, abutment/pontic ratio, and the presence of distal extensions (cantilevers) did not affect the prosthetic outcomes. Bone levels around implants were stable, with an average rate of change of -0.01 ± 0.05 mm/month. Cox regression revealed that grafted sites were correlated with peri-implant bone loss, while longer prosthetic spans were correlated with bone gain. CONCLUSION: P-FDPs comprised of milled fiber-reinforced composite frameworks, supported by short and extra-short implants, had high survival and success rates for up to 10 years.

Total Hip Arthroplasty in Patients With Classic Hemophilia: A Matched Comparison of 90-Day Outcomes and 5-Year Implant Survival.

BACKGROUND: Patients with classic hemophilia can develop joint hemarthroses, degenerative changes, and eventually require total hip arthroplasty (THA). Little data exist concerning THA outcomes in this population, and evidence-based guidelines specifically addressing venous thromboembolism (VTE) prophylaxis in this population are lacking. METHODS: A retrospective study was conducted using the 2010-2020 PearlDiver MHip database. Patients undergoing primary THA were identified, and those with classic hemophilia were matched 1:10 with non-hemophilia patients based on age, gender, and Elixhauser Comorbidity Index. Ninety-day serious adverse events, minor adverse events, and any adverse events were compared with multivariate analysis. Reoperation at 5 years was assessed using Kaplan-Meier analysis. RESULTS: Five hundred eighteen classic hemophilia THA patients were matched 1:10 with 5,193 non-hemophilia patients. On multivariate analysis, those with classic hemophilia had greater odds of aggregated any adverse events (odds ratio [OR] 1.76), serious adverse events (OR 2.30), and minor adverse events (OR 1.52) (P < .001 for each). Patients with classic hemophilia had greater odds of bleeding issues (transfusion, OR 1.98; hematoma, OR 4.23; P < .001 for both), VTE (deep vein thrombosis, OR 2.67; pulmonary embolism, OR 4.01; P < .001 for both), and acute kidney injury (OR 1.63; P = .03). Five-year implant survival was lower in hemophilia patients (91.9%) relative to matched controls (95.3%; P = .009). CONCLUSION: Hemophilia patients undergoing THA had elevated risks of both 90-day bleeding complications (transfusion and hematoma) and VTE (deep vein thrombosis and pulmonary embolism) relative to matched controls. These findings emphasize the need to balance factor replacement and VTE prophylaxis. Although the 5-year implant survival was lower in hemophilia patients, this represented a difference of 3.4% at 5 years, suggesting that THA remains effective in this cohort.

Mid-term implant survival, functional and radiological results and mechanical complications of mega-prosthetic reconstruction around the knee with the PENTA® system.

AIM: Mega-prosthetic reconstruction is the most common treatment method for massive osteoarticular defects caused by tumor resection around the knee. The new implant is a highly modular rotational-hinged megaprosthesis system with a distinct pentagonal stem geometry and variable implantation options. The aim of this study is to present the mid-term implant survival characteristics, functional and radiological results and mechanical complication profile of the new megaprosthesis. METHODS: One hundred and one mega-prosthetic knee reconstruction procedures in 90 patients (M/F: 51/39) utilizing the new implant system were retrospectively analyzed. In 68 patients, the megaprosthesis was used for primary reconstruction following tumor resection while it was used for revision of other implants in 22. The mean age was 28.5 (7-66) years and the mean follow-up was 59.2 (24-124) months. The most common primary pathology was osteosarcoma with 63-70% patients, the most common anatomical site of involvement was the distal femur with 56-62% patients. RESULTS: Henderson Type 2 failure (aseptic loosening) was seen in only 2-2.2% patients while Type 3 (structural failure) was seen in 29-32.2% Although the 5-year anchorage survival rate was 94.3%, overall mechanical implant survival was 76.1% at 5 years due to a relatively high failure rate in the first-generation hinge mechanism of the implant. The 5-year hinge survival rate demonstrated a significant improvement rate from 61.7% to 87.2% between the first and second generations of the implant (p = 0.027). The mean MSTS score was 24 out of 30 (14-29). The mean cumulative ISOLS radiographic score for index megaprosthesis operations was 19.7 (12-24), which corresponded to excellent outcome. CONCLUSION: The new megaprosthesis system is a reliable choice for the reconstruction of tumor-related massive osteoarticular defects around the knee. Although long-term follow-up is necessary for a definitive evaluation of the implant's survival characteristics, midterm follow-up yields exceptional anchorage properties related to pentagonal stem geometry with very good functional outcomes.

Prosthesis and implant survival in immediately loaded full arch restorations using fiber-reinforced versus non-reinforced temporary frameworks: a randomized clinical trial / Sobrevivência de próteses e implantes em restaurações de arcada completa com carga imediata usando estruturas temporárias reforçadas com fibra versus estruturas temporárias não reforçadas: um ensaio clínico randomizado

Objective: To evaluate and compare prosthesis and implant survival in case of interim fixed complete dentures reinforced with fiber resin frameworks versus those that were not reinforced with any framework in case of immediately loaded full arch restorations in completely edentulous patients. Material and Methods: Thirty completely edentulous patients were randomly allocated into two parallel arm groups. Non-reinforced control group in which patients received non-reinforced all-on-four immediately loaded fixed complete denture and Fiber reinforced group in which patients received all-on-four fixed complete denture supported with glass-fiber reinforced resin framework. Prosthesis and implant survival were clinically evaluated after 4 months follow up period. Results: A statistically significant difference for prosthesis (p = 0.032) and implant survival (p = 0.031) was found between both groups. The fiber-reinforced group showed 100% prosthesis survival and 95% implant survival. On the other hand, the non-reinforced group showed 73.3% prosthesis survival and 81.1% implant survival. Conclusion: Based on the findings of this study, it can be concluded that strengthening the fixed full arch restorations with fiber reinforced frameworks can help overcoming the problem of interim prosthesis fracture during the osseointegration period when used for immediate loading in completely edentulous patients. It can also improve the survival of the immediately loaded implants. (AU)

Objetivo : Avaliar e comparar a sobrevivência de próteses e implantes no caso de próteses totais fixas provisórias reforçadas com estruturas de resina de fibra versus aquelas que não foram reforçadas com nenhuma estrutura no caso de restaurações de arcada completa com carga imediata em pacientes completamente desdentados. Material e Métodos : Trinta pacientes completamente desdentados foram alocados aleatoriamente em dois grupos de braços paralelos. Grupo controle não reforçado, no qual os pacientes receberam prótese total fixa (all-on-four) não reforçada, com carga imediata e grupo reforçado com fibra, no qual os pacientes receberam prótese total fixa (all-on-four), suportada com estrutura de resina reforçada com fibra de vidro. A sobrevivência da prótese e do implante foi avaliada clinicamente após 4 meses de acompanhamento. Resultados : Foi encontrada diferença estatisticamente significante para prótese (p=0,032) e sobrevivência do implante (p=0,031) entre os dois grupos. O grupo reforçado com fibra apresentou 100% de sobrevivência da prótese e 95% de sobrevivência do implante. Por outro lado, o grupo não reforçado apresentou 73,3% de sobrevivência da prótese e 81,1% de sobrevivência do implante. Conclusão: Com base nos achados deste estudo, pode-se concluir que o fortalecimento das restaurações fixas de arcada completa com estruturas reforçadas com fibras pode ajudar a superar o problema da fratura da prótese provisória durante o período de osteointegração quando usada para carga imediata em pacientes completamente desdentados. Também pode melhorar a sobrevivência dos implantes carregados imediatamente (AU).

Rehabilitation of shortened dental arches: A fifteen-year randomised trial.

BACKGROUND: Few long-term studies on treatments in the shortened dental arch (SDA) are available. OBJECTIVE: The objective of this trial was to analyse the long-term success of two different treatment concepts. METHODS: Patients over 35 years of age with missing molars in one jaw and at least the canine and one premolar present on both sides were eligible. In the partial removable dental prosthesis (PRDP) group (N = 81), molars and missing second premolars were replaced by a precision attachment retained prosthesis. In the SDA group (N = 71), the dental arch ended with the second premolar that had to be present or replaced by a cantilever fixed dental prosthesis. Follow-up examinations were carried out over 15 years. RESULTS: A comprehensive outcome variable comprised four failure categories for which Kaplan-Meier survival (success) analyses were conducted. Half of the patients exhibited a continuous preservation of the per protocol prosthetic status that remained totally unaffected by complications for more than 10 years. The event-free success rates for moderate or worse failure implied a loss of the per protocol prosthetic status. The respective survival rates fell below 50% at 14.2 years in the PRDP group and 14.3 years in the SDA group. In none of the analyses, a significant group difference was found. CONCLUSIONS: In patients with an SDA condition, changes in the prosthetic status have to be expected. The affected proportion increases almost linearly from shortly after treatment and comprises the majority after 15 years. The influence of the examined treatments on success appears to be low.

Does the type of surgical approach affect the clinical outcome of total knee arthroplasty?

BACKGROUND: The aim of the study was to investigate the issue of medial midvastus (MMV) vs. medial parapatellar (MPP) approaches in total knee arthroplasty (TKA). It was hypothesized that the two surgical approaches would produce significantly different results with respect to patient-reported knee score outcome (hypothesis 1), short-term postoperative range of motion (ROM) (hypothesis 2), long-term postoperative ROM (hypothesis 3) and prosthesis survival (hypothesis 4). METHODS: A retrospective comparative study design was applied. Data sets were obtained from the state arthroplasty registry. The Western Ontario and McMaster Universities osteoarthritis index (WOMAC) data were analyzed from preoperative and 1 year postoperatively. The ROM data were analyzed for the time points preoperative, postoperative days 4 and 10 and 1 year. RESULTS: Available were 627 cases (407 MMV vs. 220 MPP) and 1 year postoperatively there were no significant differences between groups regarding the WOMAC scores (hypothesis 1). Early postoperatively on days 4 and 10 after TKA there were no differences between groups (p = 0.305 and p = 0.383, respectively, hypothesis 2). Likewise, ROM did not significantly differ between the groups 1 year after TKA (p = 0.338, hypothesis 3). The 5­year prosthesis survival did not differ between the groups and showed 94.46% (95% confidence interval, CI 90.69-96.73%) in the MMV group and 94.33% (95% CI 89.96-96.83%) in the MPP group (p = 0.664, hypothesis 4). CONCLUSION: Both surgical approaches produce equivalent clinical results in terms of early postoperative ROM, late postoperative ROM and 1­year WOMAC. The same prosthesis survival rates can be expected.

Clinical, Functional, and Midterm Survival Analysis on Sigma Curved Plus Ultracongruent Polyethylene Insert in Primary Total Knee Arthroplasty: A Retrospective Study.

BACKGROUND: Posterior-stabilized (PS) total knee arthroplasty (TKA) poses problems such as the need for intercondylar notch bone resection as well as cam and post wear and patella clunk. Owing to its heightened anterior profile, an ultracongruent polyethylene insert prevents the excessive posterior translation of tibia in the case of a deficient or scarified posterior cruciate ligament (PCL). This study aimed to determine whether an ultracongruent insert provides satisfactory clinical and functional outcomes and midterm survival benefits. METHODS: Based on the reviewed medical records of 200 patients, 240 primary TKA cases involving the use of Sigma Curved Plus (DePuy International, Ltd., Leeds, UK) ultracongruent insert were retrospectively enrolled in this study. Follow-up data were used to evaluate the clinical and radiological outcomes and to conduct a Kaplan-Meier survival analysis. RESULTS: The mean follow-up duration for 224 knees was 5.8 years (range 5-6.5 years). A revision was made due to infection in two patients and due to periprosthetic fractures in two other patients. The mean knee flexion improved from 101.97° ± 9.43° (range 85°-125°) to 125.75° ± 9.58° (range 100°-140°) at the final follow-up. The mean Knee Society score improved from 43.1 ± 9.76 to 88.3 ± 3.2, and the function score improved from 44.95 ± 7.26 to 90.16 ± 3.71. None of the patients showed radiographic loosening of either insert component, but 22 (5%) patients showed radiolucent lines (<2 mm). The Kaplan-Meier analysis showed that the five-year survival of the insert with an endpoint of revision for any reason was 98.1% (confidence interval, CI, 95.7-99.6%). CONCLUSION: The Sigma Curved Plus insert showed a low failure rate with good clinical, functional, and midterm survival outcomes in comparison to standard outcomes reported in earlier studies. Further follow-up studies are warranted to determine whether the insert's performance is maintained in the long term.

SECEC Grammont Award 2017: the prejudicial effect of greater tuberosity osteotomy or excision in reverse shoulder arthroplasty for fracture sequelae.

HYPOTHESIS: The aim was to evaluate risk factors for complications, revision, and mid- to long-term outcomes after reverse shoulder arthroplasty (RSA) implanted for proximal humeral fracture sequelae (PHFS). METHODS: The radiographs of 98 patients (mean age, 68 years) who underwent RSA for the treatment of PHFS were reviewed at a minimum 5-year follow-up. PHFS were divided into 4 types according to the Boileau classification: type 1 (46 cases), type 2 (6 cases), type 3 (12 cases), and type 4 (34 cases). The tuberosities underwent osteotomy in 28 cases and excision in 12 (all type 3 or 4 PHFS). The mean follow-up period was 8.4 years (range, 5-14 years). RESULTS: The functional results and rate of RSA survival without revision (85% vs. 100% at 10 years, P = .007) were significantly lower for types 3 and 4 vs. types 1 and 2. Overall, our findings showed that RSA for PHFS is not the panacea that surgeons once believed: At a mean follow-up of 8.5 years (range, 5-14 years), 59% of the patients in our series had fair or poor results. Patients who underwent tuberosity osteotomy or excision had lower functional results (adjusted Constant score, 69% vs. 88%; P < .001), more postoperative complications (32% vs. 9%, P = .003), and a higher revision rate (15% vs. 2%, P = .017). Patients who underwent tuberosity osteotomy or excision at the time of RSA were at risk of postoperative prosthetic instability and humeral stem loosening. The absence of the greater tuberosity at last radiographic follow-up was predictive of higher rates of complications and revisions, as well as a poorer final outcome. Previous fracture fixation was associated with a higher rate of complete tuberosity resorption (56% vs. 33%, P = .026) and with higher rates of postoperative complications (27% vs. 13%, P = .099) and reinterventions (17% vs. 2%, P = .018). CONCLUSION: The functional results and rates of complications and revision depend on the type of fracture sequelae and tuberosity management. Patients with more severe (type 3 and 4) fracture sequelae who undergo tuberosity osteotomy or excision are at risk of having a poorer functional result and higher rates of complications and revision with lower survival. Previous fracture fixation is also a prejudicial factor.

Prosthesis Survival Rates and Prosthetic Complications of Implant-Supported Fixed Dental Prostheses in Partially Edentulous Patients.

PURPOSE: To determine the prevalence and distribution of prosthetic complications affecting implant-supported fixed dental prostheses (ISFDPs). MATERIALS AND METHODS: Subjects previously treated with one or more ISFDP(s) were identified from an electronic health record search and recalled for comprehensive clinical examination. Past prosthesis failures and complications were identified from the patient records while any existing complications, not previously recorded, were assessed during examination. ISFDP survival and failure rates were calculated with Kaplan-Meier curves and life table analysis, while regression Poisson analysis was used to identify associations between outcomes and possible patient- and prosthesis-based risk factors. RESULTS: Seventy-four subjects with 107 ISFDPs were enrolled in the study with a mean time between prosthesis delivery and exam of 3.14 years (range: 1.00-9.00 years). Four prostheses failed, resulting in a cumulative prosthesis survival rate of 96.26%. Prosthetic complications affected 48.59% of ISFDPs, the majority (94.87%) of them minor complications. Only the use of a nightguard was associated with a lower prevalence of prosthetic screw loosening (HR 0.11, 95% CI 0.02-0.59, p = 0.007) while no outcome differences were noted for other variables. Patient satisfaction was high regardless of presence or number of complications. CONCLUSIONS: ISFDPs demonstrated a high survival rate and overall high, patient-reported satisfaction. Minor prosthetic complications were common but were only significantly associated with nightguard use.

Long-term outcomes of limb salvage treatment with custom-made extendible endoprosthesis for bone sarcoma around the knee in children.

BACKGROUND: Limb salvage for bone sarcoma around the knee in skeletally immature children is challenging because of interference on two critical growth plates in the lower limb. This retrospective study aims to evaluate long-term outcomes and influence on growth of the lower limb of the cemented extendible endoprostheses. METHODS: Forty-five children with bone sarcoma around the knee, who underwent custom-made extendible endoprosthesis replacements, were included in this study. The average follow-up was 10.1 years. Survival, prosthetic-related complications and revision, functional outcomes, and influence on growth by prosthesis implantation were recorded. RESULTS: The 5-year disease-free survival and overall survival are 54.9% and 72.7%, and the 5-year prosthesis survival rate is 59.4%. The prosthesis was extended 4.2 cm in average. Limb length discrepancies of 20 patients were within 2 cm, and growth inhibition of proximal tibial epiphysis by passive implant insertion was observed. Aseptic loosening in 7 patients was the most significant complication. The Musculoskeletal Tumor Society score at last visit was 83.2%. CONCLUSIONS: The use of custom-made extendible endoprosthesis provided good functional results for children with bone tumor around the knee. Further improvement of the prosthesis design and operation technique will help to decrease complication and gain better limb function.

[Importance of the tibial slope in knee arthroplasty]. / Bedeutung des tibialen Slopes in der Knieendoprothetik.

Notwithstanding the contributions of soft tissue restraints on postoperative kinematics and long-term survival after total knee arthroplasty (TKA), there is an emerging consensus that the underlying anatomy, especially the posterior inclination of the tibial plateau in the sagittal plane (tibial slope), might just have a comparable impact. However, this has not been fully elucidated as yet. Therefore, a thorough literature search, analysis and presentation of current scientific data was conducted. The tibial slope has been shown to relate linearly to the postoperative range of motion and function of the extensor mechanism. Furthermore, it impacts wear of the tibial insert and loosening, as well as instability of the TKA. As no consensus has been reached on the ideal tibial slope, recommendations range from 0° to 10°. Notably, more recent studies favor reconstructing the native, preoperative tibial slope, and the majority of authors advocate that knowledge of this is crucial for optimal TKA surgery.

Technical Complications and Prosthesis Survival Rates with Implant-Supported Fixed Complete Dental Prostheses: A Retrospective Study with 1- to 12-Year Follow-Up.

PURPOSE: To report the rate of technical complications and prosthesis survival in a cohort of edentulous patients treated with implant-supported fixed complete dental prostheses (IFCDPs) after a mean observation period of at least 1 year. MATERIALS AND METHODS: The single-visit examination included clinical and radiographic assessment, occlusal analysis, photographs and questionnaire assessing patient satisfaction in a cohort of 52 patients rehabilitated with 71 IFCDPs (supported by 457 implants). The IFCDPs were assessed for technical complications, number of implants and cantilever extension, retention type and prosthetic material type. Comparison was made between ceramic IFCDPs (Group 1) and metal-resin IFCDPs (Group 2). Kaplan-Meier survival curve analysis was carried out for assessment of prosthesis survival and was done for both Groups 1 and 2 separately. The Cox proportional hazard model was used for survival analysis, adjusting for a number of potential confounders, to evaluate the association between prosthesis survival and several risk factors such as type of opposing occlusion, nightguard use, and presence of bruxism. Responses to patient satisfaction questions were compared with Fisher's exact test. RESULTS: Out of 71 edentulous arches (52 patients) restored with IFCDPs, 6 IFCDPs had failed, yielding a cumulative prosthesis survival rate of 91.6 % after a mean observation period of 5.2 years (range: 1-12 years) after definitive prosthesis insertion. Three IFCDPs were lost due to implant failures after 5.8 to 11 years of functional loading. Additionally, 3 metal-resin IFCDPs failed due to technical complications. Minor complications were the most frequent complications observed, namely wear of the prosthetic material (9.8% annual rate) being the most common, followed by decementation of cement-retained IFCDPs (2.9%), and loss of the screw access filing material of the screw-retained IFCDPs (2.7%). The most frequently observed major complication was fracture of the prosthetic material (1.9% annual rate), followed by fracture of occlusal screw (0.3%), and fracture of framework (0.3%). The annual rate of wear of prosthetic material was 7.3% for porcelain IFCDPs (n = 19/55) and 19.4% for metal-resin IFCDPs (n = 13/16), yielding a statistically significant difference between the 2 groups (p = 0.01). CONCLUSIONS: After a mean exposure time of 5.2 years, 91.6% prosthesis survival rates were achieved (65 out of 71 IFCDPs). The most frequent minor technical complication was wear of the prosthetic material with estimated 5-year rate of 49.0%, while the most frequent major complication was fracture of the prosthetic material with estimated 5-year dental unit-based rate of 9.5%. The cumulative rates for "prosthesis free of minor complications" at 5- and 10-years were 60.5% (95% CI: 47.2-71.3%) and 8.9% (95% CI: 2.9-18.0%), respectively. The cumulative rates for "prosthesis free of major technical complications" at 5- and 10-years were 85.5% (95% CI: 73.0-92.5%) and 30.1% (95% CI: 12.0-50.6%), respectively. Presence of bruxism, and absence of a nightguard were associated with increased risk for chipping of the prosthetic material of the IFCDPs.

Surgical resection and reconstructive techniques using autologous femoral head bone-grafting in treating partial acetabular defects arising from primary pelvic malignant tumors.

BACKGROUND: The aim of this study is to present and evaluate surgical resection and reconstructive techniques using autologous femoral head bone-grafting in treating partial acetabular defects arising from primary pelvic malignant tumors. METHODS: From January 2009 until January 2015, a total of 20 primary pelvic malignancy cases involving the acetabulum were retrospectively investigated. Surgical resections and reconstructions were conducted based on the type of the tumor with custom osteotomy guides and autologous femoral head bone-grafting. In all cases, prosthesis survival period, complication occurrence, and clinical outcomes data were collected and analyzed. RESULTS: Thirteen male and 7 female patients with an average age of 48 years old (range 23-69 years old) were followed for a median of 69 months (range 48-112 months). Of these cases, 17 included chondrosarcomas and 3 additional patients with a malignant giant cell tumor of bone (MBGCT) as proven by pathology. During follow-up, 3 cases of chondrosarcoma recurred (15%), of which two cases received hemi-pelvic amputation, 1 case of MBGCT relapsed and developed pulmonary metastases. Two cases of acetabular prosthesis with an impending dislocation received closed reduction followed by 6 weeks of hip abduction brace fixation. One case of prosthesis loosening was revised. In another case a deep infection occurred with debridement and prosthesis removal. Musculoskeletal Tumor Society 1993 (MSTS-93) score was utilized to conduct functional evaluation: 13 cases were good, 6 were average and one was poor. CONCLUSION: The precision of the osteotomies performed is likely crucial for this type of reconstructive strategy to be successful. The use of custom guides for acetabular osteotomies and femoral head reconstruction can improve functional outcomes with relatively low complications at the intermediate length of follow-up.

Relationship between Radiographic Misfit and Clinical Outcomes in Immediately Loaded Complete-Arch Fixed Implant-Supported Prostheses in Edentulous Patients.

PURPOSE: To examine if an uncorrected radiographically detected immediate postoperative misfit (implant level or abutment level) in immediately loaded conversion prosthesis plays a significant role in early implant or prosthesis failure. In addition, clinical characteristics related to type of arch, implant position, type of implant, implant orientation, type of connection, and type of surgery were analyzed relative to their relationship to early implant or prosthesis failure. MATERIALS AND METHODS: Immediate postoperative and subsequent follow-up panoramic radiographs of 425 arches with immediately loaded complete-arch fixed implant-supported prostheses were screened in a retrospective analysis. Implants with misfit and nonmisfit within a given arch were summarized separately with respect to each clinical characteristic and the difference between misfit and nonmisfit groups was tested using a mixed-effects logistic regression model with a patient-specific random intercept. A p-value <0.05 was determined to be statistically significant. RESULTS: A total of 2025 implants from 311 patients were identified in the 425 arches that were screened for radiographic misfit. A total of 48 implants with misfit were found within 33 arches (23 patients) for a 2.4% prevalence rate. Among the misfit implants, two failures were documented during the healing phase for an early implant survival rate of 95.8%. Five conversion prostheses with misfit fractured during the healing phase for early prosthesis survival rate of 84.8%. None of the clinical variables analyzed were significantly associated with the misfit status (p < 0.05). CONCLUSIONS: The results from this retrospective study showed that misfit in immediately loaded complete-arch fixed implant-supported prostheses may not play a detrimental role in the implant survival but may affect survival of the conversion prostheses.

Comparative Analysis of Early Follow-up of Biologic Fixation and Cemented Stem Fixation for Femoral Tumor Prosthesis.

OBJECTIVE: To compare the safety and efficacy between biologic fixation and traditional cement stems for the fixation of distal femoral prostheses for reconstruction following tumor resection. METHODS: Retrospective analysis was performed of patients who received a first distal femoral tumor prosthesis, with a rotating hinge, in the Department of Orthopaedic Oncology of Beijing Jishuitan Hospital between October 2011 and January 2016. Two hundred and sixty eligible cases were enrolled, with a cemented fixation used in 199 of these cases and a biologic fixation in 61 cases. Survival rates and survival time of prostheses were analyzed, with prosthetic failure considered as the endpoint event for survival time of the prosthesis. Kaplan-Meier survival curve and the log-rank test were used to compare survival rates between the two types of fixation methods, and factors that may affect the survival rate of prosthesis were evaluated. RESULTS: Of the 260 cases forming our study group, 138 were males and 122 females, with 102 males and 97 females in the cemented fixation group (mean age, 25.8 years; range, 8-72 years) and 36 males and 25 females in the biologic fixation group (mean age, 25.5 years; range, 12-59 years). Osteosarcoma was the most common type of tumor (188 cases, 72.3%), of which 145 cases (72.9%) were in the cemented and 45 cases (72.1%) in the biologic fixation group. Among the 260 cases enrolled into the study group, 13 patients were lost to follow-up. The average duration of follow-up for the remaining 247 cases was 28.8 months (median, 28.8 months; range, 4-61 months). The 3-year overall survival rate of prostheses was 87.2% for the biologic fixation group and 80.4% in the cemented fixation group (P = 0.389). The 3-year mechanical survival rate (excluding cases of infection and oncologic progression) was 100% for the biologic fixation and 97.6% for the cemented fixation group (P = 0.468). Complications were identified in 21 cases: 3 cases (5%) in the biologic and 18 cases (9.6%) in the cemented fixation group (P = 0.264). Two revisions were required in the cemented fixation group, but no revision was required in the biologic fixation group. A total of 10 patients required amputation after prosthesis implantation. Of these, 7 cases (4 cement and 3 biologic) were due to tumor recurrence; 3 cases were due to infection, with all cases occurring in the cement fixation group. CONCLUSION: The current study provides a baseline reference for future mid-term to long-term follow-up, laying the foundation for further studies and comparison of the incidence of aseptic loosening of both types of prosthesis.