252. Joint Decisions: Optimal Duration of Chronic Suppressive Antibiotics in Adults with Prosthetic Joint Infections Who Underwent Debridement, Antibiotics, Irrigation, and Retention of Prostheses

Background Hip and knee arthroplasties are associated with complications including prosthetic joint infections (PJI). Management ranges from explantation to debridement, antibiotics, irrigation, and retention of prostheses (DAIR). In DAIR, patients receive intravenous antibiotics followed by chronic suppressive antibiotics. Current guidelines on suppressive antibiotic use after DAIR are unclear and based on expert consensus. This study seeks to elucidate the optimal duration of chronic suppressive antibiotics after DAIR. Methods This is a retrospective cohort study of adults in the Southern California Kaiser Permanente System with hip and knee prosthetic joint infections who underwent DAIR from 2007-2017. Culture data and durations of suppressive antibiotics were collected and patients were followed for 1 year after completion. Treatment failure was determined by mortality, re-infection, or prosthesis removal. Patients who received no antibiotics vs. less than 3 months vs 3 to 6 months vs greater than 1 year were compared. Results 350 charts were reviewed and 145 patients were included. There were 87 knee and 58 hip PJIs with 32 patients (22%) who failed treatment. There were more cases of failure when patients didn’t receive suppressive antibiotics (27%) vs those who received any (19%), however the results were not significant. There were no significant differences in failure rates between short vs longer suppressive antibiotic courses regardless of the duration (Staph vs non-Staph, hip vs knee). Patients with Staphyloccocal infections and knee infections were significantly more likely to fail treatment (p=0.0196 & 0.0150, logistic regression). Conclusion This study shows the importance of suppression with oral antibiotics after PJIs are treated with DAIR. The lack of difference in treatment failure between the durations of suppressive antibiotics makes it prudent to consider shorter courses of antibiotics, while placing attention on patients with knee and Staphylococcal infections as they are more likely to fail treatment. Limitations include sample size, difficulty in quantifying extent of initial infection and debridement, and provider dependent prolonging of antibiotic duration. Disclosures All Authors: No reported disclosures

Dentist’s Perspective Regarding Usage of Different Fixed Prosthesis Removal Systems in Islamabad and Rawalpindi

Background: Crowns and multi-unit fixed partial dentures have a limited lifetime. They fail for a number of reasons. The removal of provisional crowns and bridges is generally simple, however for permanent crowns, it becomes more challenging. Careful removal of FPD can help a dentist simplify a resto or endo procedure. The aim of this article was to analyze the different methods available for the removal of crowns and bridges and their awareness among dental practitioners Study Design & location: This was a cross-sectional study based on a questionnaire. The questionnaire was filled by a total of 250 general and specialist dentists who were practicing in various individual and group-based dental practices as well as private and government setups of Islamabad and Rawalpindi. Methodology: The questionnaire comprised a total of 13 questions to find out dentists' views about the usage of different system’s available for dental crowns and FPD removal. Participants were selected by random sampling. The results were then analyzed using SPSS version 23. Frequencies, percentages of different variables used in the study were calculated to identify the co-relation among different attributes. P-value of less than or equal to 0.05 was considered statistically significant. Results: The study reflected that out of those who answered, 247 dental professionals (98.5 %) preferred using hemostats or Morrell sliding hammer or a combination of both as they offered better control of force. A small percentage (approx 2%) of dentists used diamond or carbide burs as their first preference to trim off old crowns. Clinicians rarely used laser due to its high cost and less availability and its effectiveness primarily related to Porcelain jacket/ Zirconium crowns. Conclusion: It was concluded from this study that the majority of dentists preferred Morrell type crown remover with sliding hammer due to its ease of availability, universal acceptance, simple to use and because as it offered better control of force as opposed to spring-lock type Keywords: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure.

Peri-implant health after supportive mucositis therapy is associated with increased levels of FGF-2

This study aimed to analyze Fibroblast Growth Factor-2 (FGF-2) levels in the peri-implant crevicular fluid throughout supportive mucositis therapy. Twenty-six participants with Branemark protocol prosthesis were divided into two groups: the control group, characterized by healthy peri-implants, and the mucositis group, presenting a diagnosis of peri-implant mucositis. All participants underwent clinical examination, radiographic analysis, prosthesis removal, and non-invasive peri-implant therapy (mechanical debridement associated with chlorhexidine 0.12%) during a period of 36 days divided into three intervals. Peri-implant crevicular fluid samples were collected at each interval in order to analyze FGF-2 levels by immuno-enzymatic assay. The control and mucositis groups showed difference in keratinized mucosa. The smaller the range of keratinized mucosa the higher susceptibility of peri-implant mucositis. Throughout the treatment intervals, participants were diagnosed in different groups indicating whether or not the non-invasive therapy was able to treat peri-implant mucositis. There was a significant difference of FGF-2 levels between groups, with the higher FGF-2 levels in the control group (p=0.01). After supportive therapy, the mucositis group showed significantly increased FGF-2 levels (p<0.01) compared to initial levels. After 36 days of supportive therapy, there was a reduction of peri-implant mucositis from 70% to 23%. Clinical and laboratory outcomes showed a clear correlation since FGF-2 levels increased after 36 days. It was concluded that the therapy protocol was effective and promoted a regenerative reaction and FGF-2 can be considered a future target for peri-implant mucositis understanding.

3D-Printed Titanium Custom-Made Prostheses in Reconstruction after Pelvic Tumor Resection: Indications and Results in a Series of 14 Patients at 42 Months of Average Follow-Up

Wide resection is currently considered the mainstay treatment for primary bone tumors. When the tumor is located in anatomically complex segments, 3D-Printed Titanium Custom-Made Prostheses (3DPTCMP) are possible reconstructive solutions. The aim of the present paper is to analyze indications, results and complications of a series of 14 patients who underwent pelvis reconstruction with 3DPTCMP after tumor removal from January 2015 to December 2019. Chondrosarcoma was the main histology; indications were tumors located in the acetabular area without enough residual bone to support a cup with an iliac stem, and tumors located near the sacrum-iliac joint. The margins were wide in 12 cases, and marginal and intralesional in one case each. In three cases, resection also included the sacrum-iliac joint, so a spine stabilization was performed and linked to the pelvic prosthesis; The average MSTS score was 46.3%; the 5-year local recurrence-free survival was 85.7%. Wound dehiscences were the main complication, resolved with multiple debridements; nevertheless, prosthesis removal was necessary in one case. Currently, the 3DPTCMP is an effective resource for reconstruction after resection of tumors located in the pelvis. Further studies are necessary to value long-term results; more strategies are necessary to try to reduce the infection rate and improve osteointegration.

Residual limb volume fluctuations in transfemoral amputees

This study constitutes the first attempt to systematically quantify residual limb volume fluctuations in transfemoral amputees. The study was carried out on 24 amputees to investigate variations due to prosthesis doffing, physical activity, and testing time. A proper experimental set-up was designed, including a 3D optical scanner to improve precision and acceptability by amputees. The first test session aimed at measuring residual limb volume at 7 time-points, with 10 min intervals, after prosthesis doffing. This allowed for evaluating the time required for volume stabilization after prosthesis removal, for each amputee. In subsequent sessions, 16 residual limb scans in a day for each amputee were captured to evaluate volume fluctuations due to prosthesis removal and physical activity, in two times per day (morning and afternoon). These measurements were repeated in three different days, a week apart from each other, for a total of 48 scans for each amputee. Volume fluctuations over time after prosthesis doffing showed a two-term decay exponential trend (R2 = 0.97), with the highest variation in the initial 10 min and an average stabilization time of 30 min. A statistically significant increase in residual limb volume following both prosthesis removal and physical activity was verified. No differences were observed between measures collected in the morning and in the afternoon.Clinical Trials.gov ID: NCT04709367.

Residual limb volume changes in transfemoral amputees

This study constitute the first attempt to systematically quantify residual limb volume changes in transfemoral amputees. The study was carried out on 24 amputees to investigate changes due to prosthesis doffing, physical activity, and testing time. A proper experimental set-up was designed, including a 3D optical scanner, to improve precision and acceptability by amputees. The first test session aimed at measuring residual limb volume at 7 time-points, with 10 minute intervals, after prosthesis doffing. This allowed for evaluating the time required for volume stabilization after prosthesis removal, for each amputee. In subsequent sessions, 16 residual limb scans in a day for each amputee were captured to evaluate volume changes due to prosthesis removal and physical activity, in two times per day (morning and afternoon). These measurements were repeated in three different days, a week apart from each other, for a total of 48 scans for each amputee. Volume changes overtime after prosthesis doffing showed a two-term decay exponential trend (R2 = 0.97), with the highest change in the initial 10 minutes and an average stabilization time of 30 minutes. A statistically significant increasing effect of both prosthesis removal and physical activity was verified. No differences were observed between measures collected in the morning and in the afternoon.

Balance and functional disorders in geriatric patients after total hip prosthesis removal

BACKGROUND: One of the most difficult complications of total hip arthroplasty is an infection in the area of the implant with an incidence of 0.5% to 2.5% resulting in the most severe situation in prosthesis removal. OBJECTIVE: The aim of the study was to assess postural stability and functional disorders in patients after hip prosthesis removal. METHODS: A group of 15 patients after hip prosthesis removal was compared to a control group of 15 healthy persons who were age-matched without any symptoms of degenerative disorders in the lower spine and lower extremities. The static balance test was conducted on a bi-modular stabilometric platform, registering the movement of the centre of foot pressure. The functional state of the patients was assessed on the basis of the Harris Hip Score (HHS). RESULTS: Patients had poor functional result (HSS mean 62.29 ± 12.92 points). Obtained results of postural stability of patients showed huge difficulties maintaining stability and showed statistically significant differences in a majority of the analysed parameters. CONCLUSIONS: Several stability parameters showed significantly worse results in patients after hip prosthesis removal. Special attention should be paid and focused physiotherapy should be undertaken for patients with a stability disorder and functional status to prevent falls and improve functioning.

Wide Anterior Maxillary Reconstruction with Equine Bone Xenograft: A Case Report of 24-Month Follow-Up

Introduction. Orofacial reconstruction plays an important role in the treatment of patients affected by oral and maxillofacial cancers. Improvements in technologies and studies of biomaterials have widely expanded surgical possibilities to achieve good functional and aesthetic outcomes. By the way, xenografting procedures gained great consensus in the last decades, because of their documented reliability and efficacy. We present a case of anterior maxillary chondrosarcoma (CHS) that has undergone surgical ablation followed by reconstruction with an equine-derived bone xenograft. Case Presentation. A 68-year-old woman affected by CHS of the premaxilla underwent surgical ablation involving the four incisors followed by reconstruction using an equine-derived bone substitute. Bony reconstruction was planned to achieve implant and dental prosthetic rehabilitation at a second surgical time. Primary surgery was carried out without complications. Good integration of the graft was confirmed by radiological examination. At 12-month follow-up, the patient refused the implant placement and spontaneously adopted a mobile prosthesis. One year later, plates and screws were removed, because of the exposure of a titanium plate. The graft was finally rejected within 3 weeks. Discussion. Nonantigenic equine-derived biomaterials have shown reliability and a good safety profile. In the presented case, implant insertion should have been performed 12 months after the primary surgery. During the follow-up, until dental mobile prosthesis was applied, clinical and instrumental examinations demonstrated a good integration of the graft. We suppose that a chronic inflammation of the mucosa led to the exposure of the plate, perhaps due to pressure, minimal movements, or imperfect fitting of the mobile prosthesis. Removal of fixation means was performed to prevent grafting failure, without success. On the other hand, missing load could induce the graft to act just like a prosthesis, without a real process of integration. Safety and reliability of equine-derived bone xenografts cannot be currently confirmed if not followed by implant insertion and dental rehabilitation.