Freeze-dried noncoagulating platelet-derived factor concentrate is a safe and effective treatment for early knee osteoarthritis.

PURPOSE: While a wide variety of platelet-rich plasma (PRP) solutions has been developed, innovation continues. In this case, the freeze-dried platelet factor concentrate (PFC-FD) represents another step in PRP refinement. The preparation of PFC-FD at a central laboratory with freeze drying for shelf stabilization should provide additional quality improvements if clinical effectiveness can be demonstrated. Therefore, this study was undertaken to assess the safety and effectiveness of PFC-FD in a prospective open-label trial of patients suffering from knee osteoarthritis (OA). METHODS: 312 consecutive knee OA patients (67% female, mean age 63 ± 10 years), were prospectively recruited in an outpatient knee clinic in Japan. Of these, 10 (3.2%) were lost to follow-up at < 12 months and 17 (5.5%) sought additional knee therapy during the follow-up period. The primary outcome of interest was achievement of the OMERACT-OARSI responder criteria with secondary outcomes of adverse events and PROMs scores 1, 3, 6, 12 months following a single PFC-FD injection. RESULTS: 285 patients (91%) completed 12 month PROMs. The 17 who sought additional therapy were considered failures leaving an effective sample size of 302 for our primary outcome in which 62% of patients achieved OMERACT-OARSI responder status by 12 months. This varied by OA class with Kellgren-Lawrence grade 4 patients 3.6 times less likely to be responders than grade 1-2 patients. 6% of patients experienced a non-serious adverse event, primarily pain or swelling at the injection site. CONCLUSIONS: PFC-FD provides an observable clinical improvement in 62% of knee OA patients at 12 months post-injection with very little risk of any clinically relevant adverse event. Of course, nearly 40% of patients did not experience an observable clinical improvement, primarily among those with worse KL grades. LEVEL OF EVIDENCE: Therapeutic, Level II.

Using peer role-playing to improve students' clinical skills for musculoskeletal physical examinations.

BACKGROUND: The traditional curriculum for medical students in Japan does not include sufficient opportunities for students to develop their skills for musculoskeletal (MSK) examination and clinical reasoning and diagnosis. Therefore, an effective programme is required to help medical students and residents improve their clinical skills in MSK. This paper aims to assess the clinical skills of medical students who have participated in a peer role-playing simulation programme using a mini clinical evaluation exercise (mini-CEX). METHODS: Participants were 90 female medical students who were completing their first orthopaedic clinical clerkship. They were divided into two groups. The simulation group participated in a role-play focussed on MSK cases as low-fidelity simulation, a structured debriefing with the course supervisor, and a self-reflection on Day 1 (n = 64). The control group did not participate in the role-play due to randomised clerkship schedules (n = 26). On Day 2 of the intervention, we observed and assessed all participants' performances during MSK outpatient encounters using the mini-CEX. We compared the mini-CEX score between the simulation group and the control group; the Wilcoxon rank-sum test was used for statistical analysis. RESULTS: The mini-CEX scores for physical examination, clinical reasoning and diagnosis, and overall clinical competency were significantly higher in the simulation group than in the control group (p < .05, physical examination: p = .014, clinical reasoning: p = .042, overall: p = .016). These findings suggest that medical students who partake in a peer role-playing simulation programme could experience improved clinical skills for physical examination, clinical reasoning and diagnosis, and overall clinical competency in real-life MSK outpatient encounters. CONCLUSIONS: Through a mini-CEX assessment, our findings indicate that medical students who participated in our peer role-playing simulation programme have improved clinical skills. Peer role-playing as a low-fidelity simulation and practical educational opportunity will enable educators to polish the competency of medical students in musculoskeletal physical examinations and clinical reasoning and diagnosis in a clinical setting.

Comparative Clinical Outcomes After Intra-articular Injection With Adipose-Derived Cultured Stem Cells or Noncultured Stromal Vascular Fraction for the Treatment of Knee Osteoarthritis.

BACKGROUND: Intra-articular injection of adipose-derived stem cells (ASCs) has shown promise for improving symptoms and cartilage quality in the treatment of osteoarthritis (OA). However, while most preclinical studies have been performed with plastic-adherent ASCs, most clinical trials are being conducted with the stromal vascular fraction (SVF), prepared from adipose tissue without prior culture. PURPOSE: To directly compare clinical outcomes of intra-articular injection with ASCs or SVF in patients with knee OA. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The authors retrospectively compared 6-month outcomes in 42 patients (59 knees) receiving intra-articular injection with 12.75 million ASCs and 38 patients (69 knees) receiving a 5-mL preparation of SVF. All patients had Kellgren-Lawrence grade 2, 3, or 4 knee OA and had failed standard medical therapy. The visual analog scale (VAS) pain score and Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline and 1, 3, and 6 months after injection were considered as outcomes. Outcome Measures in Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) criteria were also used to assess positive response. A repeated measures analysis of variance was used for comparison between the treatment groups. RESULTS: No major complications occurred in either group. The SVF group had a higher frequency of knee effusion (SVF 8%, ASC 2%) and minor complications related to the fat harvest site (SVF 34%, ASC 5%). Both groups reported improvements in pain VAS and KOOS domains. Specifically, in the ASC group, symptoms improved earlier (by 3 months; P < .05) and pain VAS decreased to a greater degree (55%; P < .05) compared with the SVF group (44%). The proportion of OMERACT-OARSI responders in the ASC group was slightly higher (ASCs, 61%; SVF, 55%; P = .25). CONCLUSION: It was observed that both ASCs and SVF resulted in clinical improvement in patients with knee OA, but that ASCs outperform SVF in the early reduction of symptoms and pain with less comorbidity.

Incidence of osteonecrosis and insufficiency fracture of the hip and knee joints based on MRI in 300 renal transplant patients.

INTRODUCTION: The purpose of this study was to investigate the incidence of necrosis and insufficiency fracture of the hip and knee using magnetic resonance imaging (MRI) in renal transplant patients. METHODS: We examined 300 consecutive renal transplant patients using MRI of the hips and knees (T1-weighted coronal MRI) preoperatively and at 3 and 6 months postoperatively. Oblique axial-plane T1-weighted MRI and short-tau inversion-recovery T2-weighted MRI were performed parallel to the femoral neck when distinguishing the osteonecrosis of the femoral head (ONFH) from subchondral insufficiency fracture (SIF) of the femoral head was difficult. RESULTS: ONFH was observed in 3 hips (3 cases, 1.0%). Osteonecrosis of the knee was observed in 2 knees (1 case, 0.3%). SIF of the femoral head was observed in 5 hips (3 cases, 1.0%). Bilateral simultaneous onset of SIF of the femoral head was observed in 2 cases (0.7%). Insufficiency fracture of the knee was observed in 2 knees (1 case, 0.3%). CONCLUSIONS: When it was difficult to distinguish ONFH from SIF of the femoral head, oblique axial-plane T1-weighted MRI and the short-tau inversion-recovery T2-weighted MRI parallel to the femoral neck were useful to establish the correct diagnosis.

Custom-made, antibiotic-loaded, acrylic cement spacers using a dental silicone template for treatment of infected hip prostheses.

PURPOSE: Antibiotic-loaded acrylic cement (ALAC) spacers are useful for treatment of infected prostheses in the course of a two-stage revision. Spacers are handmade or are made using a commercial template, with reportedly good treatment outcomes. This study aimed to confirm the usefulness of custom-made ALAC spacers shaped like bipolar hip prostheses using a dental silicone template for treatment of infected hip prostheses, and described their manufacture. METHODS: This study evaluated 10 patients who underwent two-stage revision for treatment of infected hip prostheses. Custom-made ALAC spacers were used in all patients. Templates were made with dental silicone. We investigated the following in treatment of the infected hip prostheses: bacterial pathogens; antibiotic-cement mixtures; waiting time to revision; dislocation, breakage, and migration of custom-made ALAC spacers; current hip status; progress during follow-up; presence or absence of recurrence; and walking ability. RESULTS: Dislocation, breakage, and migration were not observed in custom-made ALAC spacers. All patients recovered after two-stage revision without additional surgery and showed no recurrence during the follow-up period. CONCLUSION: Custom-made ALAC spacers shaped like bipolar hip prostheses using a template made of dental silicone may be useful for treatment of infected hip prostheses.

Blood metal ion concentrations in metal-on-metal total hip arthroplasty.

INTRODUCTION: The hip placement with a metal-on-metal (MOM) bearing has been used for both surface replacement and total hip arthroplasty (THA). Use of MOM bearing for hip replacement reduces the wear compared to conventional bearings. METHODS: We prospectively assessed 30 patients who underwent unilateral MOM THA. A control group of 30 patients who underwent metal-on-polyethylene THA using the implants as the other group, except for bearing, were accessed. Blood samples were collected preoperatively and at 3- , 6- , 9- , 12- , 15- , 18- , and 24-month intervals. Changes in mean blood metal ion concentration were compared between the MOM and metal-on-polyethylene groups. RESULTS: A statistically significant positive correlation was observed between blood cobalt and chromium concentrations in all of the patients. The mean blood ion concentrations of the MOM were significantly higher than those of the metal-on-polyethylene. A statistically significant negative correlation was found between maximum blood cobalt concentration and cup version angle. The maximum blood chromium concentrations in the patients who had larger cup version angles were more likely to decrease. CONCLUSIONS: We considered that cup version angle is one of the factors that have the greatest effect on blood metal ion concentration, and the target cup version angle that did not induce an increase in blood metal ion concentrations was approximately 20°.

Usefulness of measuring acetabular anterior coverage using a tomosynthesis imaging system.

PURPOSE: The purpose of this study was to compare the usefulness of measuring acetabular anterior coverage by tomosynthesis and false profile (FP) radiography. METHODS: 70 hips in 35 patients who were diagnosed with early stage osteoarthritis of the hip, and 60 hips from 30 healthy volunteers were analysed. Plain FP radiographs were taken, and vertical-centre-anterior margin (FP-VCA) angles were measured. Acetabular anterior coverage was measured in the natural standing position using a tomosynthesis imaging system in the sagittal plane. As with FP radiography, we measured vertical-centre-anterior margin (TS-VCA) angles. RESULTS: The median values of the FP-VCA angle, and TS-VCA angle were 43.8°, 54.4°, respectively. The TS-VCA angle was significantly larger than the FP-VCA angle. For FP radiographs, the intraobserver intraclass correlation coefficient (ICC) was 0.68, and the interobserver ICC was 0.79. For tomosynthesis sagittal images, the intraobserver ICC was 0.85, and the interobserver ICC was 0.92. There was a strong positive correlation between the TS-VCA angle and the FP-VCA angle. When the FP-VCA angle was 25°, the TS-VCA angle was 35° in regression analysis. CONCLUSIONS: Measuring acetabular anterior coverage using sagittal plane tomosynthesis correlates well with FP radiography. Regardless of the presence of acetabular deformities, tomosynthesis demonstrated high reproducibility, simple posture setting, low effective doses, and high versatility. A cut-off value of 35° was useful for the detection of developmental dysplasia of the hip joint using the TS-VCA angle.

A Case of Legg-Calvé-Perthes Disease due to Transient Synovitis of the Hip.

Transient synovitis (TS) of the hip develops spontaneously in childhood; it usually has a good prognosis and is a self-limiting disease. However, its pathology is not well known. We describe a case of Legg-Calvé-Perthes disease (LCPD) that seemingly developed due to TS. Even if TS is diagnosed on the basis of the patient's medical history and imaging findings, physicians should consider the possibility of LCPD and perform a careful observation if joint effusion continues and/or a symptom does not improve within 4 weeks.

Risk assessment and usefulness of musculocutaneous flap transposition for recurrent septic arthritis of the hip in adults.

PURPOSE: Septic arthritis of the hip joint in adults often progresses to recurrent infections that require repeated surgeries for treatment. The purpose of the present study was to assess the risk of a recalcitrant hip infection and the usefulness of musculocutaneous flap transposition. METHODS: 15 adult patients who underwent surgeries for the treatment of hip infections were retrospectively analysed. Patients who recovered from infection by undergoing arthroscopy, open irrigation, debridement, continuous irrigation, resection arthroplasty, and/or the placement of antibiotic-loaded acrylic cement were classified into Group A (n = 10). Patients who showed residual infection after multiple surgeries and ultimately recovered after undergoing musculocutaneous flap transposition were classified into Group B (n = 5). The age at onset, sex, incidence of multi-drug-resistant organisms, incidence of infection at other sites, compromising factors, peak preoperative C-reactive protein level, and period from onset to initial surgery were compared between groups. RESULTS: There was a statistically significant difference in the period from onset to initial surgery (p = 0.024). The infections remained chronic after multiple surgeries in most patients who had complications and/or a poor general or local condition. All of the patients recovered after musculocutaneous flap transposition without the need for additional surgery and did not experience recurrence during the follow-up period in Group B. CONCLUSIONS: Delayed diagnosis and/or treatment and compromised host caused recurrent septic arthritis of the hip in adults. Musculocutaneous flap transposition may be a useful method for the treatment of recalcitrant hip infection.

Atraumatic Anterior Dislocation of the Hip Joint.

Dislocation of the hip joint in adults is usually caused by high-energy trauma such as road traffic accidents or falls from heights. Posterior dislocation is observed in most cases. However, atraumatic anterior dislocation of the hip joint is extremely rare. We present a case of atraumatic anterior dislocation of the hip joint that was induced by an activity of daily living. The possible causes of this dislocation were anterior capsule insufficiency due to developmental dysplasia of the hip, posterior pelvic tilt following thoracolumbar kyphosis due to vertebral fracture, and acetabular anterior coverage changes by postural factor. Acetabular anterior coverage changes in the sagittal plane were measured using a tomosynthesis imaging system. This system was useful for elucidation of the dislocation mechanism in the present case.