High rate of undetected infections in failed osteosynthesis of pertrochanteric fractures.

OBJECTIVE: The objective of this study was to assess the incidence of infection in patients with cut-out after PFF osteosynthesis. METHODS: Design: Retrospective cohort study. SETTING: Third-level trauma center. PATIENT SELECTION CRITERIA: Patients presenting with a cut-out following proximal femur fracture (PFF) (OTA/AO 31A) osteosynthesis, between January 2007 to December 2020. OUTCOME MEASUREMENTS: The primary outcome was infection according to EBJIS criteria. RESULTS: Sixty-seven patients presenting with a cut-out were included, with mean age of 83.3 years (range 63-96) and 51 (76.1%) were women. Of all cases, 16 (24.7%) presented a concomitant infection. The presence of concomitant infection was suspected preoperatively in only 3 of the cases. A subgroup analysis was performed between the cases with infection and those without infection, the groups being comparable in terms of demographic data and postoperative radiological criteria. Patients with underlying infection had a higher rate of surgical wound complication (56.3% vs 22%, p = 0.014) and higher rates of leukocytosis (11.560 vs 7.890, p = 0.023). CONCLUSION: Faced with a cut-out after osteosynthesis of a proximal femur fracture, underlying infection should be considered as a possible etiological factor. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fibronectin-coated polyurethane meniscal scaffolding supplemented with MSCs improves scaffold integration and proteoglycan production in a rabbit model.

PURPOSE: The role of mesenchymal stem cells (MSC) in supporting the formation of new meniscal tissue in a meniscal scaffold is not well understood. The objective of this study was to assess the quality of the meniscal tissue produced in a fibronectin (FN)-coated polyurethane (PU) meniscal scaffold after a meniscal injury was made in an experimental rabbit model. METHODS: Twelve New Zealand white rabbits were divided in two groups after performing a medial meniscectomy of the anterior horn. In group 1, the meniscal defect was reconstructed with a non-MSC supplemented FN-coated PU scaffold. On the other hand, the same scaffold supplemented with MSCs was used in group 2. The animals were sacrificed at 12 week after index surgery. A modified scoring system was used for histological assessment. This new scoring (ranging from 0 to 15) includes a structural evaluation (meniscal scaffold interface and extracellular matrix production) and tissue quality evaluation (proteoglycan and type I-collagen content). RESULTS: The meniscal scaffold was found loose in the joint in three cases, corresponding to two cases in group 1 and 1 case in group 2. No differences were observed between the groups in terms of the total score (7.0 ± 0.9 vs. 9.4 ± 2.6, p = 0.09). However, differences were observed in group 2 in which 2 out of the 5 scored items, scaffold integration (1 ± 0.0 vs. 1.9 ± 0.6, p = 0.03) and proteoglycan production (1.2 ± 0.3 vs. 2.4 ± 0.2, p = 0.001). A trend to a higher production of Type I-Collagen production was also observed in group 2 (1.1 ± 0.4 vs. 1.4 ± 0.7, p = 0.05). CONCLUSION: In a rabbit model at 12 weeks, the adhesion of MSCs to a FN-coated PU scaffold improves scaffold integration, proteoglycan production and the characteristics of the new meniscal-like tissue obtained when compared to a non-supplemented scaffold. This fact could be a major step toward improving the adhesion of the MSCs to meniscal scaffolds and, consequently, the obtention of better quality meniscal tissue.

Mini-invasive approach vs. traditional open reduction for periprosthetic hip fracture osteosynthesis with the NCB® plate.

BACKGROUND: Postoperative hip periprosthetic fracture (PPF) is a frequent complication whose treatment does not achieve optimal results among eldery fragile patients. Locking compression plate (LCP) osteosynthesis is the gold standard treatment for Vancouver B1 and VC fractures and there is a growing consensus in doing the same with B2 fractures in patients with high comorbidity. Following that trend of being as non-aggressive as possible we investigated whether a mini-open (MO) approach would lead to better outcomes in LCP plate osteosynthesis of hip PFFs when compared to the traditional open approach. METHODS: We retrospectively evaluated a cohort of 43 VB1, VB2 or VC hip PPFs treated with non contact bridging (NCB®) plate osteosynthesis by two possible approaches. MO vs traditional open approach. The main objective was to assess whether MO approach decreases operative time, bleeding and local complications. The secondary objective was to demonstrate that this may have a positive effect on patient function. RESULTS: The mean age was 79.6 years old and 74.5% patients had an ASA score of III or IV. The surgical time was 148.53 min (SD 33.2) in the open approach versus 107.42 min (SD 25.6) in the MO, which was 31 min shorter (p<0.001). Hemoglobin dropped 0.9 points less, on average (p. 0.005) and 0.82 fewer blood concentrates were required (p. 0.022) with MO approach. There were no differences among complications but there was a trend towards greater independence and better mobility in the MO approach group with a postoperative Barthel of 74.37 (sd. 13.21) compared to the 66.67 points (sd. 13.7) in the traditional approach group. CONCLUSION: MO approach in osteosynthesis of hip PFFs decreases operative time and intraoperative bleeding so it must be considered in fragile patients with high comorbidity.

Acute Hematogenous Periprosthetic Hip Infection by Gemella morbillorum, Successfully Treated with Debridement, Antibiotics and Implant Retention: A Case Report and Literature Review of Osteoarticular Gemella morbillorum Infections.

Gemella morbillorum is a facultative anaerobic, catalase-negative and non-spore forming Gram-positive cocci. It can be found as part of the normal oropharyngeal flora, in the gastrointestinal tract and the female genital tract. However, it can be a causal agent of infections such as endocarditis, meningitis or brain abscesses, and very rarely can cause osteoarticular infections. Herein, a case report of an acute hematogenous prosthetic hip infection caused by Gemella morbillorum, successfully treated with a DAIR and beta-lactam antibiotic therapy, is presented. We provide a literature review of the other orthopedic-related infections caused by this microorganism.

Fibronectin-coating enhances attachment and proliferation of mesenchymal stem cells on a polyurethane meniscal scaffold.

INTRODUCTION: Partial meniscectomy is one of the most common surgical strategy for a meniscal injury, but sometimes, patients complain of knee pain due to an overload in the ablated compartment. In these cases, implantation of tissue engineering scaffold could be indicated. Currently, two commercial scaffolds, based on collagen or polycaprolactone-polyurethane (PCL-PU), are available for meniscus scaffolding. In short term follow-up assessments, both showed clinical improvement and tissue formation. However, long-term studies carried out in PCL-PU showed that the new tissue decreased in volume and assumed an irregular shape. Moreover, in some cases, the scaffold was totally reabsorbed, without new tissue formation.Mesenchymal stem cells (MSCs) combined with scaffolds could represents a promising approach for treating meniscal defects because of their multipotency and self-renewal. In this work, we aimed to compare the behaviour of MSCs and chondrocytes on a PCL-PU scaffold in vitro. MSCs express integrins that binds to fibronectin (FN), so we also investigate the effect of a FN coating on the bioactivity of the scaffold. METHODS: We isolated rabbit bone marrow MSCs (rBM-MSCs) from two skeletally mature New Zealand white rabbits and stablished the optimum culture condition to expand them. Then, they were seeded over non-coated and FN-coated scaffolds and cultured in chondrogenic conditions. To evaluate cell functionality, we performed an MTS assay to compare cell proliferation between both conditions. Finally, a histologic study was performed to assess extracellular matrix (ECM) production in both samples, and to compare them with the ones obtained with rabbit chondrocytes (rCHs) seeded in a non-coated scaffold. RESULTS: A culture protocol based on low FBS concentration was set as the best for rBM-MSCs expansion. The MTS assay revealed that rBM-MSCs seeded on FN-coated scaffolds have more cells on proliferation (145%; 95% CI: 107%-182%) compared with rBM-MSCs seeded on non-coated scaffolds. Finally, the histologic study demonstrated that rCHs seeded on non-coated scaffolds displayed the highest production of ECM, followed by rBM-MSCs seeded on FN-coated scaffolds. Furthermore, both cell types produced a comparable ECM pattern. CONCLUSION: These results suggest that MSCs have low capacity attachment to PCL-PU scaffolds, but the presence of integrin alpha5beta1 (FN-receptor) in MSCs allows them to interact with the FN-coated scaffolds. These results could be applied in the design of scaffolds, and might have important clinical implications in orthopaedic surgery of meniscal injuries.

Electric Scooter-Related Injuries: A New Epidemic in Orthopedics.

BACKGROUND: The use of electric scooters has increased considerably as they are an accessible means of transportation. The number of injuries from falls and collisions has risen significantly. Therefore, the aim of the study was to describe demographics injury patterns of electric scooter accidents produced over one year. METHODS: A prospective observational study of electric scooter- related injuries presented in the emergency room from May 2019 until May 2020. The inclusion criteria was based on the direct cause of injury produced while an electric scooter was in use. Demographic data, the use of a helmet or the lack thereof, accident mechanism, injury time, type of injury produced, and the treatment applied were collected. RESULTS: Over the study period, 397 patients were identified with a total of 422 injuries. The mean age was 30.8 years, with 12.6% of patients being minors. The patients mainly presented in evening hours and in summertime at the emergency department. Of the total injuries seen, 46.9% were fractures. Some 25% of the total cases required surgery. Only 19% of the riders wore a helmet at the time of the accident. Most of the fractures were to the upper limbs (62.6%). There was a greater incidence of radius fractures. CONCLUSION: Injuries incurred while using electric scooters are an emerging phenomenon, despite existing regulations. In this study, most injuries occurred in young men and were due to falls from the vehicle. Nearly half of those injuries were fractures to the upper limbs. Surprisingly, 50% of the fractures required surgery.

Preoperative antibiotic prophylaxis in prosthetic joint infections: not a concern for intraoperative cultures.

BACKGROUND: Culture negative prosthetic joint infections (PJI) still remain an issue even with the advantages of the new diagnostic tools for PJI. This is why some orthopedic surgeons have reservations relative to the use of preoperative antibiotic prophylaxis when a PJI is suspected. The purpose of the present study was to evaluate the influence of preoperative antibiotic prophylaxis on intraoperative cultures. MATERIAL AND METHODS: An enhanced diagnostic protocol for PJI (Zimmerli criteria) was used for the inclusion criteria in order to collect all PJI that were seen in a university hospital. Patients were prospectively randomized into two groups. The control group received the classical preoperative antibiotic prophylaxis. The study group did not receive prophylaxis prior to surgery. RESULTS: There were 14 patients in each group. They correspond to 13 total hip arthroplasty infections, 12 total knee arthroplasty infections and 3 reverse shoulder prosthesis infections. There were 10 patients in the study group and 10 patients in the control group with at least one positive microbiological criterion (P > 0.05). There were 4 patients in each group with a culture negative PJI (P > 0.05). CONCLUSIONS: Preoperative antibiotic prophylaxis does not affect intraoperative cultures in suspected or confirmed PJI. Therefore it is essential to deliver antibiotic prophylaxis in any patient in which a prosthesis is to be implanted in order to protect the prosthesis from infection.

MiRNA profiling of whole trabecular bone: identification of osteoporosis-related changes in MiRNAs in human hip bones.

BACKGROUND: MicroRNAs (miRNAs) are important regulators of gene expression, with documented roles in bone metabolism and osteoporosis, suggesting potential therapeutic targets. Our aim was to identify miRNAs differentially expressed in fractured vs nonfractured bones. Additionally, we performed a miRNA profiling of primary osteoblasts to assess the origin of these differentially expressed miRNAs. METHODS: Total RNA was extracted from (a) fresh femoral neck trabecular bone from women undergoing hip replacement due to either osteoporotic fracture (OP group, n = 6) or osteoarthritis in the absence of osteoporosis (Control group, n = 6), matching the two groups by age and body mass index, and (b) primary osteoblasts obtained from knee replacement due to osteoarthritis (n = 4). Samples were hybridized to a microRNA array containing more than 1900 miRNAs. Principal component analysis (PCA) plots and heat map hierarchical clustering were performed. For comparison of expression levels, the threshold was set at log fold change > 1.5 and a p-value < 0.05 (corrected for multiple testing). RESULTS: Both PCA and heat map analyses showed that the samples clustered according to the presence or absence of fracture. Overall, 790 and 315 different miRNAs were detected in fresh bone samples and in primary osteoblasts, respectively, 293 of which were common to both groups. A subset of 82 miRNAs was differentially expressed (p < 0.05) between osteoporotic and control osteoarthritic samples. The eight miRNAs with the lowest p-values (and for which a validated miRNA qPCR assay was available) were assayed, and two were confirmed: miR-320a and miR-483-5p. Both were over-expressed in the osteoporotic samples and expressed in primary osteoblasts. miR-320a is known to target CTNNB1 and predicted to regulate RUNX2 and LEPR, while miR-483-5p down-regulates IGF2. We observed a reduction trend for this target gene in the osteoporotic bone. CONCLUSIONS: We identified two osteoblast miRNAs over-expressed in osteoporotic fractures, which opens novel prospects for research and therapy.

Salvage for nail breakage in femoral intramedullary nailing.

Proximal fractures of femur represent an important cause of hospitalization, morbidity and mortality for elderly patients. Femoral intramedullary nailing is an option to achieve a stable osteosynthesis but the breakage is a rare complication. The aim was to determinate the prevalence, causes, management and functional outcomes of this patients in our hands. Retrospective review of 1246 proximal femur fractures operated between 2003 and 2012. We analyse epidemiological data, fracture type and the quality of closed reduction and fixation by preoperative and postoperative radiology. Type of salvage procedure chosen for each case is presented. Functional outcome and quality of life questionnaire was obtained by Barthel index and Short Form 12 version 2. 11 cases (0.88%) were identified. The type of initial fracture was 7 cases AO/OTA 31A3 and 4 cases AO/OTA 31A2. The implant failure was detected at 11 months after surgery (SD 6.39). Nail breakage occurred in three different points: 7 cases in the proximal aperture, 3 cases in cervicocephalic screw and 1 case in the distal aperture of the nail. The association of nonunion at fracture site and progressive hip pain was observed in all cases. Different salvage procedures were performed: 7 cases osteosynthesis revision (nail or dynamic condilar screw plate), 2 cases arthroplasty and 2 cases conservative treatment. The main Barthel score before the salvage procedure was 63.2 (SD 13). At final follow-up, this score improved to 72.8 (SD 20.38). To the best of our knowledge, this study represents the largest series of cases of trochanteric nail breakage due to material fatigue. This complication is rare (0.88%) that can foresee in unstable fractures with delayed union. The type of salvage should be individualized showing acceptable functional outcome in our series.

Implantation of a polycaprolactone scaffold with subchondral bone anchoring ameliorates nodules formation and other tissue alterations.

PURPOSE: Articular cartilage has limited repair capacity. Two different implant devices for articular cartilage regeneration were tested in vivo in a sheep model to evaluate the effect of subchondral bone anchoring for tissue repair. METHODS: The implants were placed with press-fit technique in a cartilage defect after microfracture surgery in the femoral condyle of the knee joint of the sheep and histologic and mechanical evaluation was done 4.5 months later. The first group consisted of a biodegradable polycaprolactone (PCL) scaffold with double porosity. The second test group consisted of a PCL scaffold attached to a poly(L-lactic acid) (PLLA) pin anchored to the subchondral bone. RESULTS: For both groups most of the defects (75%) showed an articular surface that was completely or almost completely repaired with a neotissue. Nevertheless, the surface had a rougher appearance than controls and the repair tissue was immature. In the trials with solely scaffold implantation, severe subchondral bone alterations were seen with many large nodular formations. These alterations were ameliorated when implanting the scaffold with a subchondral bone anchoring pin. DISCUSSIONS: The results show that tissue repair is improved by implanting a PCL scaffold compared to solely microfracture surgery, and most importantly, that subchondral bone alterations, normally seen after microfracture surgery, were partially prevented when implanting the PCL scaffold with a fixation system to the subchondral bone.

Cervicocephalic medial screw migration after intertrochanteric fracture fixation, OTA/AO 31-A2, using intramedullary nail Gamma3: report of 2 cases and literature review.

Cervicocephalic screw medialization is a rare complication after intertrochanteric fracture synthesis with a Gamma3-type intramedullary nail. Only 6 cases of intrapelvic penetration by Gamma3 lag screw have been described. We now describe 2 additional cases and a review of the literature.

Effects of an educational audiovisual videodisc on patients' pre-operative expectations with total knee arthroplasty: a prospective randomized comparative study.

PURPOSE: To investigate the effectiveness of an educational videodisc in modifying pre-operative patients' expectations with total knee arthroplasty (TKA) and to find a biophysical profile of subjects in whom this videodisc could be most effective. It was hypothesized that patients receiving standard information plus additional medical information through audiovisual videodiscs would modify their pre-operative expectations more than those only receiving the standard information through medical interviews. METHODS: Ninety-two patients (age, 50-90 years) with knee osteoarthritis waiting for TKA were randomized into two groups. All patients received general verbal information about this procedure. Forty-two patients (study group) additionally viewed an educational videodisc related to the whole process of TKA, whereas 50 patients did not view it (control group). Patients completed baseline and post-videodisc questionnaires regarding their expected results after TKA. RESULTS: Expectations with TKA were not modified by the audiovisual videodisc, except for knee range of motion and use of stairs. There were no differences in change of expectations between groups depending on demographic, functional, health, emotional, and cognitive variables, except for body mass index. The overall pre-operative, pre-intervention expectations were not modified by the audiovisual videodisc. CONCLUSIONS: Based on these results, the use of this complementary tool may not be systematically recommended. In addition, it was not possible to identify a biophysical profile of patients in whom the intervention could be most effective.

In vivo evaluation of 3-dimensional polycaprolactone scaffolds for cartilage repair in rabbits.

BACKGROUND: Cartilage tissue engineering using synthetic scaffolds allows maintaining mechanical integrity and withstanding stress loads in the body, as well as providing a temporary substrate to which transplanted cells can adhere. PURPOSE: This study evaluates the use of polycaprolactone (PCL) scaffolds for the regeneration of articular cartilage in a rabbit model. STUDY DESIGN: Controlled laboratory study. METHODS: Five conditions were tested to attempt cartilage repair. To compare spontaneous healing (from subchondral plate bleeding) and healing due to tissue engineering, the experiment considered the use of osteochondral defects (to allow blood flow into the defect site) alone or filled with bare PCL scaffold and the use of PCL-chondrocytes constructs in chondral defects. For the latter condition, 1 series of PCL scaffolds was seeded in vitro with rabbit chondrocytes for 7 days and the cell/scaffold constructs were transplanted into rabbits' articular defects, avoiding compromising the subchondral bone. Cell pellets and bare scaffolds were implanted as controls in a chondral defect. RESULTS: After 3 months with PCL scaffolds or cells/PCL constructs, defects were filled with white cartilaginous tissue; integration into the surrounding native cartilage was much better than control (cell pellet). The engineered constructs showed histologically good integration to the subchondral bone and surrounding cartilage with accumulation of extracellular matrix including type II collagen and glycosaminoglycan. The elastic modulus measured in the zone of the defect with the PCL/cells constructs was very similar to that of native cartilage, while that of the pellet-repaired cartilage was much smaller than native cartilage. CONCLUSION: The results are quite promising with respect to the use of PCL scaffolds as aids for the regeneration of articular cartilage using tissue engineering techniques.

Assessment of radiolucent lines in cemented shoulder hemi-arthroplasties: study of concordance and reproducibility.

We report on the concordance and reproducibility of the evaluation of radiolucent lines in the humeral component of shoulder arthroplasty. Thirty-two shoulder prostheses were assessed independently, on two occasions, by five observers. The level of inter- and intra-observer agreement was calculated using the kappa statistic. Intra-observer agreement: the overall kappa values ranged from 0 to 0.6, meaning poor, fair and moderate agreement levels. Inter-observer agreement: when the anteroposterior (AP) views were analysed, the values obtained for the bone-cement interface ranged from 0.290 to 0.539, meaning a poor-to-moderate agreement. For the cement-implant interface, the values ranged from 0.064 to 0.684, meaning a poor-to-good agreement. When radiolucent lines of the humeral component were analysed, inter-observer agreement proved to be as low as that obtained when total hip or knee components were analysed. Intra-observer agreement showed better results.