The First FDA Approved Early Feasibility Study of a Novel Percutaneous Bone Anchored Prosthesis for Transfemoral Amputees: A Prospective 1-year Follow-up Cohort Study.

OBJECTIVE: Evaluate the safety and efficacy of a novel press-fit bone-anchored prosthesis in an FDA approved study. DESIGN: Single-center, prospective 1-year follow-up cohort study of a percutaneous bone anchored prosthesis. SETTING: Veterans Health Administration Hospital. PARTICIPANTS: Ten male Veterans with unilateral transfemoral amputation that occurred at least 6 months prior to enrollment and was not the result of dysvascular disease (N=10). INTERVENTIONS: All participants received the novel press-fit Percutaneous Osseointegrated Prosthesis (POP) and a minimum of 10 days supervised rehabilitation therapy. OUTCOME MEASURES: Adverse events and radiographs were collected to assess device safety. Temporal assessments of bone density, stomal skin, prosthetic don/doff, functional ambulation, and patient-reported outcome compared our POP to a socket suspension system. RESULTS: Ten male participants mean age 48.8±12.1 years (range, 32-68 y) with mean time since amputation of 9.4± years (range 1-18 y) completed a two-staged implantation protocol and progressed to ambulation with an assistive device by post-operative day 14. Eight of 10 completed all study procedures. One implant loosened at 5 weeks, requiring removal. A second was removed after periprosthetic fracture from a non-device-related fall at 28 weeks. One patient required oral antibiotics for superficial infection. There were significant (P<.05) increases in bone density in the lumbar spine and adjacent to the distal porous coating with no radiographic evidence of bone resorption. Compared to the socket system, the use of POP significantly (P<.05) reduced prosthetic don and doff times and patient-reported prosthetic problem scores. Significant improvements (P<.05) in mean mobility, global health, and walking test scores were also observed. CONCLUSIONS: Improvements in bone density, function, and patient reported outcomes were observed with the POP device when compared to a socket suspension system. This Early Feasibility Study established initial safety and effectiveness of the POP device, supporting expanded investigation as an alternative to socket prostheses.

Impact of a Musculoskeletal "Mini-Residency" Professional Development Program on Knee Magnetic Resonance Imaging Orders by Primary Care Providers.

BACKGROUND: The US Department of Veterans Affairs has created a portfolio of educational programs to train primary care providers (PCPs) in the evaluation and management of common musculoskeletal (MSK) conditions. Appropriate resource utilization for evaluation of knee pain, including limiting unnecessary magnetic resonance imaging (MRI) studies, is an important theme of these initiatives. The objective of this study was to report the utilization of knee MRI by PCP providers before and after the MSK education program and to determine the appropriateness of these MRI orders. METHODS: Twenty-six PCPs participated in the MSK Mini-Residency educational program held in Salt Lake City between April 2012 and October 2014. Knee MRI orders submitted by these providers 12 months before and 12 months after their participation were reviewed. Magnetic resonance imaging orders were categorized as "inappropriate," "probably inappropriate," or "possibly appropriate," based on accepted guidelines for knee MRI utilization. Differences in the numbers of precourse and postcourse MRI orders for each of these categories were compared using Student t test. RESULTS: Following our program, MRI orders decreased from 130 (precourse) to 93 (postcourse), a reduction of 28% ( p = 0.04). This reduction was observed entirely within the "inappropriate" and "probably inappropriate" categories; the number of orders categorized as "possibly appropriate" increased, but not significantly. CONCLUSIONS: The MSK Mini-Residency training program was a successful educational intervention and was associated with a reduction in inappropriate knee MRI utilization for some participants, while keeping appropriate MRI utilization stable.

Validity evidence for two objective structured clinical examination stations to evaluate core skills of the shoulder and knee assessment.

BACKGROUND: We developed two objective structured clinical examinations (OSCEs) to educate and evaluate trainees in the evaluation and management of shoulder and knee pain. Our objective was to examine the evidence for validity of these OSCEs. METHODS: A multidisciplinary team of content experts developed checklists of exam maneuvers and criteria to guide rater observations. Content was proposed by faculty, supplemented by literature review, and finalized using a Delphi process. One faculty simulated the patient, another rated examinee performance. Two faculty independently rated a portion of cases. Percent agreement was calculated and Cohen's kappa corrected for chance agreement on binary outcomes. Examinees' self-assessment was explored by written surveys. Responses were stratified into 3 categories and compared with similarly stratified OSCE scores using Pearson's coefficient. RESULTS: A multi-disciplinary cohort of 69 examinees participated. Examinees correctly identified rotator cuff and meniscal disease 88% and 89% of the time, respectively. Inter-rater agreement was moderate for the knee (87%; k = 0.61) and near perfect for the shoulder (97%; k = 0.88). No correlation between stratified self-assessment and OSCE scores were found for either shoulder (0.02) or knee (-0.07). CONCLUSIONS: Validity evidence supports the continuing use of these OSCEs in educational programs addressing the evaluation and management of shoulder and knee pain. Evidence for validity includes the systematic development of content, rigorous control of the response process, and demonstration of acceptable interrater agreement. Lack of correlation with self-assessment suggests that these OSCEs measure a construct different from learners' self-confidence.

Effectiveness of an Interprofessional and Multidisciplinary Musculoskeletal Training Program.

BACKGROUND: Musculoskeletal (MSK) problems are common, and a recent US Bone and Joint Initiative calls for new models of education and professional collaboration. Evidence of feasibility and acceptability of innovative methods are needed. OBJECTIVE: We assessed if an experimental immersion interdisciplinary MSK curriculum would be acceptable to residents from different specialties, be feasible within existing rotations, and be effective in strengthening clinical skills. METHODS: Through funding from the Veterans Affairs Office of Academic Affiliations and the Office of Specialty Care, we developed a Center of Excellence in MSK Care and Education. A core element is the monthly MSK Education Week, which teaches skills and provides opportunities to apply these in clinical settings. Participants include internal medicine, physical medicine and rehabilitation, and orthopaedic surgery residents, as well as students and residents from other health professions programs. All were assigned to the MSK week in lieu of other clinical experiences. Faculty encompassed primary care, rheumatology, endocrinology, orthopaedics, and physical medicine and rehabilitation. Assessments include surveys and a 2-station objective structured clinical examination (OSCE). RESULTS: Since 2012, a total of 176 trainees have participated. Percentage of trainees reporting ability to evaluate and manage MSK complaints increased (9% to 87% for shoulder; 18% to 86% for knee), and confidence performing MSK injections increased from 10% to 70%. Competency in evaluation of shoulder and knee pain was confirmed by OSCEs. CONCLUSIONS: The MSK week program was accepted by residents from the 3 specialties, with learners reporting improved ability to perform shoulder and knee examinations, as demonstrated by OSCEs.

"Mini-Residency" in Musculoskeletal Care: a National Continuing Professional Development Program for Primary Care Providers.

INTRODUCTION: A cost-effective professional development program enhancing musculoskeletal (MSK) skills of physicians and allied health providers working in primary care settings has been reported at a single site. This article describes the first 2 years of the national expansion and implementation of a 3-day "MSK Mini-residency." METHODS: Faculty from Veterans Affairs (VA) medical centers worked in partnership with national program faculty from the Salt Lake City VA to present an intensive, integrated, multidisciplinary program to strengthen the skills of primary care providers in evaluating and managing MSK conditions common in primary care. Course assessments included written surveys and a two-station observed structured clinical examination (OSCE) evaluating the physical examination of the shoulder and knee. RESULTS: In the first 2 years of the program, 13 VA facilities participated. Two hundred twenty-seven health care providers, including 135 physicians, were trained. Two hundred seven participants (91 %) completed all pre- and post-course written assessments and the two-station OSCE. DISCUSSION: The MSK Mini-residency program is an effective and well-received mixed-method educational initiative to strengthen the skills of primary care physicians and other health care providers in evaluating and managing patients with MSK complaints and to document their competence in performing physical examinations of the shoulder and knee. The 2-year experience in implementation suggests that this model of educational partnerships is a feasible approach to disseminating innovative educational programs in a way that preserves curricular consistency yet is adaptable to local needs.

Progression of bone ingrowth and attachment strength for stability of percutaneous osseointegrated prostheses.

BACKGROUND: Percutaneous osseointegrated prosthetic (POP) devices have been used clinically in Europe for decades. Unfortunately, their introduction into the United States has been delayed, in part due to the lack of data documenting the progression of osseointegration and mechanical stability. QUESTIONS/PURPOSES: We determined the progression of bone ingrowth into porous-coated POP devices and established the interrelationship with mechanical stability. METHODS: After amputation, 64 skeletally mature sheep received a custom porous-coated POP device and were then randomized into five time groups, with subsequent measurement of percentage of bone ingrowth into the available pore spaces (n = 32) and the mechanical pullout force (n = 32). RESULTS: Postimplantation, there was an accelerated progression of bone ingrowth (~48% from 0 to 3 months) producing a mean pullout force of 5066 ± 1543 N. Subsequently, there was a slower but continued progression of bone ingrowth (~23% from 3 to 12 months) culminating with a mean pullout force of 13,485 ± 1855 N at 12 months postimplantation. There was a high linear correlation (R = 0.94) between the bone ingrowth and mechanical pullout stability. CONCLUSIONS: This weightbearing model shows an accelerated progression of bone ingrowth into the porous coating; the amount of ingrowth observed at 3 months after surgery within the porous-coated POP devices was sufficient to generate mechanical stability. CLINICAL RELEVANCE: The data document progression of bone ingrowth into porous-coated POP devices and establish a strong interrelationship between ingrowth and pullout strength. Further human data are needed to validate these findings.

Experimental model of biofilm implant-related osteomyelitis to test combination biomaterials using biofilms as initial inocula.

Currently, the majority of animal models that are used to study biofilm-related infections use planktonic bacterial cells as initial inocula to produce positive signals of infection in biomaterials studies. However, the use of planktonic cells has potentially led to inconsistent results in infection outcomes. In this study, well-established biofilms of methicillin-resistant Staphylococcus aureus were grown and used as initial inocula in an animal model of a Type IIIB open fracture. The goal of the work was to establish, for the first time, a repeatable model of biofilm implant-related osteomyelitis, wherein biofilms were used as initial inocula to test combination biomaterials. Results showed that 100% of animals that were treated with biofilms developed osteomyelitis, whereas 0% of animals not treated with biofilm developed infection. The development of this experimental model may lead to an important shift in biofilm and biomaterials research by showing that when biofilms are used as initial inocula, they may provide additional insights into how biofilm-related infections in the clinic develop and how they can be treated with combination biomaterials to eradicate and/or prevent biofilm formation.

Percutaneous osseointegrated prostheses for amputees: Limb compensation in a 12-month ovine model.

Percutaneous osseointegrated prostheses are being investigated as an alternative strategy to attach prosthetic limbs to patients. Although the use of these implants has shown to be promising in clinical trials, the ability to maintain a skin seal around an osseointegrated implant interface is a major challenge to prevent superficial and deep periprosthetic infections. The specific aim of this study was to establish a translational load-bearing ovine model to assess postoperative limb compensation and gait symmetry following a percutaneous osseointegrated implant. We tested the following hypotheses: (1) the animals would return to pre-amputation limb loads within 12-months; (2) the animals would return to a symmetrical gait pattern (stride length and time in stance) within 12-months. The results demonstrated that one month following surgery, the sheep loaded their amputated limb to a mean value of nearly 80% of their pre-amputation loading condition; by 12-months, this mean had dropped to approximately 74%. There was no statistical differences between the symmetry of the amputated forelimb and the contralateral forelimb at any time point for the animals stride length or the time spent in the stance phase of their gait cycle. Thus, the data showed that while the animals maintained symmetric gait patterns, they did not return to full weight-bearing after 12-months. The results of this study showed that a large animal load-bearing model had a symmetric gait and was weight bearing for up to 12 months. While the current investigation utilizes an ovine model, the data show that osseointegrated implant technology with postoperative follow-up can help our human patients return to symmetric gait and maintain an active lifestyle, leading to an improvement in their quality of life following amputation.

Assessing peri-implant tissue infection prevention in a percutaneous model.

BACKGROUND: Infection remains the main challenge to percutaneous, intramedullary osseointegrated implant technology. The purpose of this investigation was to determine if a broad spectrum antimicrobial, Ceragenin (CSA-13) could prevent pin track infections in a percutaneous tibial pin site in a sheep model. METHODS: In 20 sheep, a smooth titanium alloy pin/implant was inserted percutaneously through the medial skin and both cortices of the proximal tibia. In 10 sheep, the pin/skin interface was treated with a CSA-13-embedded foam pad. Ten sheep served as controls receiving an untreated pad. At the end of 24 weeks, or if they presented with clinical signs of infection, the animals were euthanized. Histological stains were processed from soft tissue and bone, and bacterial cultures were taken from tissue, bone, and blood. In addition to clinical signs, sheep were considered infected if at least one tissue culture and/or histologically stained sample was positive. RESULTS: Compared with the controls, CSA-13 did not prevent pin track infection (p = 0.88). Large gaps around the pin indicated a lack of skin-pin adhesion. CONCLUSIONS: In this application, CSA-13 was not effective in preventing pin track infections. This study suggests that maintaining skin attachment, at the implant surface of osseointegrated implants, is essential as a primary barrier to infection. Local antimicrobial treatments should be considered a secondary barrier to bacterial invasion of the pin/skin interface and deeper tissues.