Contemporary Dual Mobility Head Penetration at Five Years: Concern for the Additional Convex Bearing Surface?

BACKGROUND: Dual mobility (DM) bearings are increasingly popular and second-generation designs contain highly cross-linked polyethylene. The purpose of this study is to report head penetration rates in modern DM bearings. METHODS: A review of 63 consecutive DM bearings was performed. Radiographs were analyzed for head penetration using Martell methodology at regular postoperative intervals. RESULTS: Thirty-four DM bearings were analyzed. Mean linear head penetration was 1.59 mm/y at 1 year, 1.07 mm/y at 2 years, and 0.27 mm/y at 5 years following an exponential regression model (R2 = 0.999). Mean volumetric wear was 783 mm3/y at 1 year, 555 mm3/y at 2 years, and 104 mm3/y at 5 years following an exponential regression model (R2 = 0.986). CONCLUSION: Initial head penetration of DM bearings is larger than contemporary cross-linked polyethylene bearings; however, rates approach steady state after 2 years, analogous to traditional bearings. The larger "bedding-in" head penetration may be due to the additional convex bearing surface, creating 2 surfaces for deformation/wear.

Mid-term Results of Femoral and Tibial Osteotomies and Fassier-Duval Nailing in Children With Osteogenesis Imperfecta.

BACKGROUND: Patients with osteogenesis imperfecta (OI) have significant burden of both fractures and bony deformities. The present approach to care in this disorder is a combination of surgical care with intramedullary rod fixation, cyclic bisphosphonate therapy, and rehabilitation with goal of maximizing patient function and quality of life. METHODS: Retrospective chart review identified 58 children with OI who had realignment osteotomies with Fassier-Duval (FD) intramedullary nailing of the lower extremity by a single surgeon. This is a consecutive series treated between 2003 and 2010. Postoperatively, patients were followed up clinically and radiologically. Motor function was assessed using the Brief Assessment of Motor Function score and the walking scale subset of the Gillette Functional Assessment Questionnaire. RESULTS: Fifty-eight patients had 179 lower extremity FD intramedullary rods placed. This technique allowed for intervention on multiple long bones, with 29% having bilateral femur and tibial rodding in the same procedure. Revisions were required in 53% of patients, which occurred at a mean time of 52 months after initial rodding surgery. In most cases, revision surgery was related to patient growth and subsequent fracture, although rod migration did occur in a minority of patients. Nonunion or incomplete union was 14.5% in this series. Bisphosphonate infusion was not postponed after surgical procedures. Patients had improvement in mobility status at the latest follow-up. CONCLUSIONS: This series lends evidence to the medium-term utility of FD intramedullary rods as an effective and less invasive platform for stabilization and correction of deformity in long bones of patients with OI. Relatively low blood loss and relatively short hospitalizations were noted. Nonunion rate was comparable with existing literature noting that our patients did not have postsurgical postponement of bisphosphonate therapy. LEVEL OF EVIDENCE: Therapeutic study to investigate the results of treatment with FD rods. Retrospective case series model of Level IV evidence quality.

Does Transparency of Ankle Implant Costs Influence Surgeon Behavior?

Background: Ankle fractures are a common injury treated by orthopaedic surgeons. Unstable, displaced ankle fractures are often fixed with open reduction internal fixation (ORIF) using different implant constructs at various cost. No study to date has looked at transparency in ankle implant costs to surgeon behavior. Our surgeons self-identified that the biggest barrier for lowering implant cost was the lack of cost transparency. This was a surgeon-led-study to evaluate whether increased transparency in implant costs affected surgeon behavior. Methods: Monthly operative logs from December 2021 to September 2022 were reviewed at our level 1 trauma center for operative fixation of ankle fractures. The cost data of each fixation construct was reported to trauma-trained surgeons at the end of each month from March 2022 to June 2022. Average costs of implants were compared before and after education. A linear mixed model was used to explore what factors were associated with changes in costs. Surgeons also participated in a poststudy survey. Results: The implant costs of 110 ankle fracture fixations were reviewed over the period before education (n = 60), during education (n = 30), and after education (n = 20). The mean implant cost difference for unimalleolar fractures was -$204.80 (P = .68), whereas the mean cost difference for bimalleolar fractures was -$9.82 (P = .98). Trimalleolar fractures had a mean cost difference of +$94.47 (P = .84). Linear mixed model demonstrated fracture pattern as the only factor significantly associated with implant costs (P < .01). Post-education surgeon survey revealed that 6 of 7 surgeons felt that monthly updates affected their implant selection. However, only 2 surgeons demonstrated a change in practice with decreased implant costs during the study. Conclusion: The majority of surgeons self-reported being influenced by the implant cost education, but the detected change in implant cost was only observed in less than one-third of surgeons. Our results suggest implant selection and related costs are not influenced by increased cost transparency education alone. Level of Evidence: Level III, case control study.

Redesigning continuing professional development: Harnessing design thinking to go from needs assessment to mandate.

BACKGROUND: The world of medicine is constantly changing, and with it the continuing professional development (CPD) needs of physicians. As the CPD landscape is shifting away from unidirectional delivery of knowledge through live large group learning (conferences) and is placing increased emphasis on new approaches for skills training not taught a decade ago, a new approach is needed. APPROACH: Using design thinking techniques, we hosted a full-day retreat for emergency medicine stakeholders in Hamilton and the surrounding region. Prior to the retreat we collected medico-legal data on emergency physicians in our region and performed a needs assessment survey. At the retreat, we had participants brainstorm ideas for CPD, generate archetypes for end-users, then generate solutions to the problems they had identified. These proposals were presented to the larger group for feedback and refinement. EVALUATION: The Design Thinking Retreat generated five main pillars for action by our CPD team. 1) Simulation/procedural learning (staff simulation, procedural skills day, in situ simulation); 2) Asynchronous learning (website and podcast); 3) Synchronous learning (small group sessions for staff); 4) Community connectivity (online platform for collaboration and communication); and 5) Coaching & mentorship (focused coaching for specific practice improvement, improved onboarding for new staff). REFLECTION: These ideas have vastly increased engagement in CPD. Stakeholder consultation via design thinking may be a key approach for educators to use.

Revision of the unstable total knee arthroplasty: outcome predictors.

Revision arthroplasty is often required for confirmed cases of symptomatic tibiofemoral instability after total knee arthroplasty (TKA). We evaluated the results of revision for TKA instability in a consecutive series of 67 patients (68 knees) between 2000 and 2006. Outcome measures were surgeon-based assessment of knee stability, Knee Society Score, and Short Form Health Survey 36. At an average of 39 months of follow-up, the mean Knee Society Score and Short Form Health Survey 36 physical and mental scores were 76, 53, and 67 points, respectively. Knee instability persisted in 14 patients (22%). Data at the 95% confidence level revealed that revising both the femoral and tibial components, the use of femoral augments, and smaller joint line elevation as measured on radiographs correlated significantly with achieving a stable knee. In revision surgery for TKA instability, revision of both components and the use of femoral augments seem to offer the most predictable outcome.

Early failure of a nonmodular titanium femoral stem after primary hip arthroplasty.

Fully porous-coated cementless implants have a low failure rate and excellent survivorship in primary and revision surgery. Failure secondary to implant fracture is extremely rare with modern implant designs. We report an early fracture of a fully porous-coated femoral stem after primary total hip arthroplasty. The implant failed because of a filling mismatch between the proximal and distal femur.

Periprosthetic joint infection: the economic impact of methicillin-resistant infections.

The orthopedic community has begun to witness a worrisome rise in the incidence of periprosthetic joint infections (PJIs) caused by resistant organisms. Besides other challenges associated with treating these infections, it appears that these infections may pose a higher cost compared to infections caused by sensitive organisms. Significantly higher cost of care for treatment of infections due to methicillin-resistant organisms were seen at a mean of $107,264 per case compared to $68,053 for treating PJI caused by sensitive strains (P < .0001). More effective strategies for preventing the spread of infections caused by resistant organisms need to be implemented to ease the social and economic strains facing the orthopedic community due to resistant organisms.

Irrigation and debridement in the management of prosthetic joint infection: traditional indications revisited.

Irrigation and debridement (I and D) is a procedure commonly used for the treatment of acute periprosthetic infection. This study retrospectively reviewed clinical records of patients with periprosthetic infection of the hip or knee who underwent I and D with retention of their prostheses between 1997 and 2005 at a single institution. One hundred four patients (44 males and 60 females) were identified. Mean age at time of initial debridement was 65 years. Average follow-up was 5.7 years. Treatment failure was defined as the need for resection arthroplasty or recurrent microbiologically proven infection. According to these criteria, I and D was successful in 46 patients (44%). Patients with staphylococcal infection, elevated American Society of Anesthesiologists score, and purulence around the prosthesis were more likely to fail. The high failure rate of this procedure implies that it should be preferably limited to select healthy patients with low virulence organisms and equivocal intraoperative findings.

Mechanical properties, oxidation, and clinical performance of retrieved highly cross-linked Crossfire liners after intermediate-term implantation.

Sixty Crossfire (Stryker Orthopaedics, Mahwah, NJ) liners were consecutively revised after an average of 2.9 years (range, 0.01-8.0 years) for reasons unrelated to wear or mechanical performance of the polyethylene. Femoral head penetration was measured directly from 42 retrievals implanted for more than 1 year. Penetration rate results (0.04 mm/y, on average; range, 0.00-0.13 mm/y) confirmed decreasing wear rates with longer in vivo times. Overall, we observed oxidation levels at the bearing surface of the 60 liners (0.5, on average; range, 0.1-1.7) comparable to those of nonimplanted liners (0.5, on average; range, 0.3-1.1) and preservation of mechanical properties. We also measured elevated oxidation of the rim (3.4, on average; range, 0.2-8.8) that was correlated with implantation time. Rim surface damage, however, was observed in only 3 (5%) of 60 cases. Retrieval analysis of the 3 rim-damaged liners did not reveal an association between surface damage and the reasons for revision.

Staged revision for knee arthroplasty infection: what is the role of serologic tests before reimplantation?

UNLABELLED: Erythrocyte sedimentation rate and C-reactive protein are common preoperative diagnostic markers for prosthetic joint infection but their prognostic role before reimplantation has yet to be defined. We therefore determined the prognostic value of erythrocyte sedimentation rate and C-reactive protein performed before second-stage reimplantation for the treatment of infected total knee arthroplasty (TKA). We studied 109 patients who had undergone two-stage revision TKA for sepsis from 1999 to 2006. Receiver operating characteristic curves were constructed to determine the discriminatory value of erythrocyte sedimentation rate and C-reactive protein before reimplantation in predicting persistent infection. Twenty-three of the 109 patients (21%) required revision surgery for recurrence of prosthetic joint infection. The receiver operating characteristic areas under the curve suggested erythrocyte sedimentation rate and C-reactive protein poorly predicted persistent infection after TKA reimplantation. Cutoff values could not be obtained because of the high variance. We reached similar conclusions regarding the change in erythrocyte sedimentation rate and C-reactive protein levels from time of resection. More accurate diagnostic tools are needed to support clinical judgment in monitoring infection progress and thus deciding whether to proceed with TKA reimplantation. LEVEL OF EVIDENCE: Level II, therapeutic study.

Outcome of a second two-stage reimplantation for periprosthetic knee infection.

UNLABELLED: Recurrent or persistent infection after two-stage exchange arthroplasty for previously infected total knee replacement is a challenging clinical situation. We asked whether a second two-stage procedure could eradicate the infection and preserve knee function. We evaluated 18 selected patients with failed two-stage total knee arthroplasty implantation treated with a second two-stage reimplantation between 1999 and 2005. Failure of treatment was defined as recurrence or persistence of infection. The minimum followup was 24 months (mean, 40 months; range, 24-83 months). Recurrent or persistent infection was diagnosed in four of 18 patients, two of whom were successfully treated with a third two-stage exchange arthroplasty. Knee Society score questionnaires administered at the last followup showed an average Knee Society knee score of 73 points (range, 24-100 points) and an average functional score of 49 points (range, 20-90 points). The data suggest repeat two-stage exchange arthroplasty is a reasonable option for eradicating periprosthetic infection, relieving pain, and achieving a satisfactory level of function for some patients. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Periprosthetic infection due to resistant staphylococci: serious problems on the horizon.

UNLABELLED: Prosthetic joint infections (PJI) caused by methicillin-resistant staphylococci represent a major therapeutic challenge. We examined the effectiveness of surgical treatment in treating infection of total hip or knee arthroplasty caused by methicillin-resistant staphylococcal strains and the variables influencing treatment success. One hundred and twenty-seven patients were treated at our institution between 1999 and 2006. There were 58 men and 69 women, with an average age of 66 years. Patients were followed for a minimum of 2 years or until recurrence of infection. Débridement and retention of the prosthesis was performed in 35 patients and resection arthroplasty in 92. Débridement controlled the infection in only 37% of cases whereas two-stage exchange arthroplasty controlled the infection in 75% of hips and 60% of knees. Preexisting cardiac disease was associated with a higher likelihood of failure to control infection in all treatment groups. Antibiotic-resistant Staphylococci continue to compromise treatment outcome of prosthetic joint infections, especially in patients with medical comorbidities. New preventive and therapeutic strategies are needed. LEVEL OF EVIDENCE: Level IV, therapeutic study.

The fate of acute methicillin-resistant Staphylococcus aureus periprosthetic knee infections treated by open debridement and retention of components.

The success of open irrigation and debridement with component retention (ODCR) for acute periprosthetic knee joint infection varies widely. The species and virulence of the infecting organism have been shown to influence outcome. This multicenter, retrospective study identified 19 cases of acute periprosthetic methicillin-resistant Staphylococcus aureus (MRSA) knee infections managed by ODCR and at least 4 weeks of postoperative intravenous vancomycin therapy. At minimum follow-up of 2 years, the treatment failed to eradicate the infection in 16 cases (84% failure rate). Of those 16 failures, 13 patients required a 2-stage exchange arthroplasty, 2 patients required repeat incision and debridement with antibiotic suppression, and 1 patient died of MRSA sepsis. In addition, a systematic review of the literature revealed failure to eradicate infection in 10 of 13 patients managed with a similar protocol. The total success rate of ODCR in acute periprosthetic MRSA knee infection was 18%.

Linagliptin-Associated Alopecia and Bullous Pemphigoid.

Bullous pemphigoid is a chronic autoimmune blistering disease. Recently, several reports suggested dipeptidyl peptidase 4 (DPP-4) inhibitors, also known as gliptins, were a potential cause of drug-induced bullous pemphigoid but not of both bullous pemphigoid and alopecia areata together. Here we describe the case of a 68-year-old man with type 2 diabetes mellitus who developed new onset diffuse alopecia on the scalp with diffuse tense bullae over his body a few months after linagliptin was introduced for better control of his diabetes. DPP-4 inhibitors are not known to increase the risk of alopecia. To the best of our knowledge, this is the first report of linagliptin-associated alopecia areata and bullous pemphigoid, which may help demonstrate if there are any links between DPP-4 inhibitors and alopecia. LEARNING POINTS: This is the first report of linagliptin-associated alopecia areata and bullous pemphigoid (BP), which may help demonstrate a link between DPP-4 inhibitors and alopecia.Since the time of onset of BP after initiation of a DPP-4 inhibitor varies, a high index of suspicion is needed for diagnosis.Early diagnosis is essential as DPP-4 inhibitor withdrawal has a significant effect on disease remission.

Deep venous thrombosis prophylaxis for total joint arthroplasty: American Academy of Orthopaedic Surgeons guidelines.

The orthopedic community continues to face a challenge with regard to the prevention of thromboembolism after total joint arthroplasty. The first and foremost issue facing surgeons is how to select the best agent or modality that is effective in preventing the untoward consequences of thromboembolism without causing other complications that can have dire consequences. Other challenges include the uncertainty regarding the dose and duration of various agents, the value of mechanical prophylaxis alone, and the exact end points that should be used to measure the efficacy of prophylaxis. This article discusses some of the recent developments in prevention and management of thromboembolism after total joint arthroplasty, in particular highlighting the guidelines that were developed by American Academy of Orthopedic Surgeons.

Periprosthetic infection: are current treatment strategies adequate?

Two-staged resection arthroplasty with delayed reimplantation is currently the method of choice for treatment of an infected total hip arthroplasty. There is paucity of data regarding the risk factors for reinfection after reimplantation. The objective of this study was to determine the efficacy of two-stage resection arthroplasty for infected THA and to identify risk factors for reinfection. The outcome of this procedure was evaluated in 54 consecutive patients at our institution from January 1999 to August 2005. The mean follow-up time for patients who were successfully treated was 32 months (range: 24 to 76 months). Infection with methicillin-resistant organisms occurred in 33 patients (61%). Recurrent infection was diagnosed in 14 patients (26%) after the second stage reimplantation procedure at an average of 10.6 months. An elevated ASA, which is an indicator of advanced comorbid health status, and infection with methicillin-resistant organisms were risk factors for treatment failure. An additional 8% of the cohort developed early mechanical failure at a mean of 13.8 months. The increase in the number of resistant organisms and the rise in the number of patients with comorbid conditions have compromised the efficacy of two-stage exchange arthroplasty. Hence novel techniques for the treatment of periprosthetic infection are desperately needed.

Does testing enhance learning in continuing medical education?

BACKGROUND: There has been growing interest in using theory-driven research to develop and evaluate continuing medical education (CME) activities. Within health professions education, testing has been shown to promote learning in a variety of different contexts, an effect referred to as test-enhanced learning (TEL). However, the extent to which TEL generalizes to CME remains unclear. The purpose of this study was to investigate whether physicians who received two intervening tests following a CME event would experience a TEL effect relative to physicians who received additional study material to review without testing. METHODS: Forty-nine physicians were recruited during a local CME activity. Physicians were randomized to either a) the test group (n=26), where participants completed two 20 multiple-choice question (MCQ) quizzes related to the lecture content or b) the study group (n=23), where participants studied the same information without testing. Testing and studying occurred independently during the CME activity, and then four weeks later online. At eight weeks, participants completed a final 20-item MCQ online test. A between-subjects t-test was used to compare performance on the final test as a function of the initial educational activity (test group vs. study group). RESULTS: Performance on the final MCQ test was equivalent for both test (Mean (SD): 75% (9.9)) and study-only (77% (7.3)) conditions (t(47) = 0.94, p=0.35). CONCLUSION: The null findings in the present study are contrary to previous findings demonstrating TEL among novice learner populations. The lack of TEL highlights several programmatic considerations that should be factored in before implementing TEL as a part of CME.

An innovative approach to identifying learning needs for intrinsic CanMEDS roles in continuing professional development.

CONTEXT: The CanMEDS framework promotes the development of competencies required to be an effective physician. However, it is still not well understood how to apply such frameworks to CPD contexts, particularly with respect to intrinsic competencies. OBJECTIVE: This study explores whether physician narratives around challenging cases would provide information regarding learning needs that could help guide the development of CPD activities for intrinsic CanMEDS competencies. METHODS: We surveyed medical and surgical specialists from Southern Ontario using an online survey. To assess perceived needs, participants were asked, 'Describe three CPD topic you would like to learn about in the next 12 months'. To identify learning needs that may have arisen from problems encountered in practice, participants were asked, 'Describe three challenging situations encountered in the past 12 months.' Responses to the two open-ended questions were analyzed using thematic content analysis. RESULTS: Responses were received from 411 physicians, resulting in 226 intrinsic CanMEDS codes for perceived learning needs and 210 intrinsic codes for challenges encountered in practices. Discrepancies in the frequency of intrinsic roles were observed between the two questions. Specifically, Leader (28%), Scholar (43%), and Professional (16%) roles were frequently described perceived learning needs, as opposed to challenges in practice (Leader: 3%; Scholar: 2%; and Professional: 8%. Conversely, Communicator 39%, Health Advocate 39%, and to a lesser extent Collaborator 11%) roles were frequently described in narratives surrounding challenges in practice, but appeared in <10% of descriptions of perceived learning needs (Communicator: 4%; Health Advocate 6%; Collaborator: 3%). CONCLUSION: The present study provides insight into potential learning needs associated with intrinsic CanMEDS competencies. Discrepancies in the frequency of intrinsic CanMEDS roles coded for perceived learning needs and challenges encountered in practice may provide insight into the selection and design of CPD activities.