Mesenchymal Cells Retain the Specificity of Embryonal Origin During Osteogenic Differentiation.

Mesenchymal stem cells (MSCs) are widely used in therapy, but the differences between MSCs of various origins and their ability to undergo osteogenic differentiation and produce extracellular matrix are not fully understood. To address this, we conducted a comparative analysis of mesenchymal cell primary cultures from 6 human sources, including osteoblast-like cells from the adult femur, adipose-derived stem cells, Wharton's jelly-derived mesenchymal cells, gingival fibroblasts, dental pulp stem cells, and periodontal ligament stem cells. We analyzed these cells' secretome, proteome, and transcriptome under standard and osteogenic cultivation conditions. Despite the overall similarity in osteogenic differentiation, the cells maintain their embryonic specificity after isolation and differentiation in vitro. Furthermore, we propose classifying mesenchymal cells into 3 groups: dental stem cells of neural crest origin, mesenchymal stem cells, and fetal stem cells. Specifically, fetal stem cells have the most promising secretome for various applications, while mesenchymal stem cells have a specialized secretome optimal for extracellular matrix production. Nevertheless, mesenchymal cells from all sources secreted core bone extracellular matrix-associated proteins. In conclusion, our study illuminates the distinctive characteristics of mesenchymal stem cells from various sources, providing insights into their potential applications in regenerative medicine and enhancing our understanding of the inherent diversity of mesenchymal cells in vivo.

Cementless Total Hip Arthroplasty With Paavilainen Femoral Shortening Osteotomy Can Provide Good Results at 10 Years in Patients Who Have Crowe IV Developmental Dysplasia of the Hip.

BACKGROUND: The aim of this study was to present the clinical and radiologic results of primary total hip arthroplasty (THA) using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV developmental dysplasia of the hip. METHODS: We retrospectively analyzed the results of primary THA using the Paavilainen technique in 335 hips. The mean follow-up was 10.2 years. The degree of limp, leg-length discrepancy, and patient satisfaction were assessed. The Oxford Hip Score was used to examine functional outcomes. A number of radiographic parameters were also assessed. RESULTS: The most common reason for revision surgery was nonunion of the distally advanced greater trochanter. This complication was observed in 22 hips (6.5%). The 10-year survival for acetabular components, it was 97.3%, and for femoral components was 98.7% with aseptic loosening as the end point, and 85.9% with reoperation for any reason as the end point. Patients demonstrated improved functional outcomes. The mean limb lengthening was 27.8 mm. Nonunion was more common if the contact length of the proximal femoral fragment with the lateral surface of the distal femoral fragment was less than 35 mm. CONCLUSIONS: Cementless primary THA using the femoral shortening osteotomy technique described by Paavilainen in patients who have Crowe IV dysplasia of the hip demonstrates good clinical and radiologic postoperative results. If the contact between the fragments after osteotomy is less than 35 mm, there is a high risk of nonunion, and supplemental fixation may be warranted.

Coonrad-Morrey total elbow arthroplasty implications in young patients with post-traumatic sequelae.

BACKGROUND: We aimed to evaluate the clinical and radiological results of total elbow arthroplasty (TEA) performed for trauma sequelae in patients <45 years of age. METHODS: This retrospective study included 63 patients aged <45 years who underwent TEA between 2005 and 2017 for previous elbow injuries. The average follow-up period was 5.23 years (range, 2-13 years). The clinical analysis included limb function according to the Mayo Elbow Performance Score, Oxford Elbow Score, and range of motion. The degree of radiolucency was determined using plain radiographic images. RESULTS: The average amplitude of elbow flexion/extension increased from 49.1 ± 36.7 to 98.7 ± 28.2 (P < .01), and the average amplitude of elbow pronation/supination increased from 87.2 ± 52.3 to 118.7 ± 26.3 (P = .02). Functional results improved from 21.4 ± 13.1 to 67.3 ± 14.5 (P < .01) on the Mayo scale, and those measured according to the Oxford scale improved from 15.4% ± 7.0% to 28.0% ± 10.6% (P < .01). Complications were observed in 16 (32.7%) patients. Among them, 10 patients (20.4%) required revision elbow arthroplasty with replacement of implant components. The overall 5-year implant survival rate was 79.4% (95% confidence interval: 63.4-91.2), and the 10-year survival rate was 77.5% (95% confidence interval: 59.3-88.2). CONCLUSION: TEA allows restoration of the full range of motion in the elbow joint and significantly improves limb function in most cases. However, the low survival rate of implants and high incidence of complications do not permit TEA to become a routine intervention for treating post-traumatic consequences in young patients.

Standard Versus Custom-Made Acetabular Implants in Revision Total Hip Arthroplasty.

BACKGROUND: Today, various options are used for the reconstruction of acetabular bone loss in revision total hip arthroplasty (RTHA). The aim of the study was to compare the outcomes of using standard acetabular implants (SAIs) and custom-made acetabular implants (CMAIs) in RTHA in cases with extensive acetabular bone loss. METHODS: This was a comparative analysis of the results of 106 operations of RTHA performed during the period from January 2013 to December 2019. In 61 cases (57.5%), CMAIs were used. In 45 cases (42.5%), SAIs were implanted. RESULTS: The incidence of aseptic loosening of the acetabular component after RTHA in uncontained loss of bone stock of the acetabulum (type III-IV as per the Gross and Saleh classification) using the CMAI was less than that using the SAI (2.4% and 10.0%, respectively). The most significant differences in aseptic loosening rates were noted after implantation of the CMAI and SAI in pelvic discontinuity with uncontained bone defect (0% and 60.0%, respectively; P<.001). CONCLUSION: The ideal indications for the use of the CMAI are uncontained defects and pelvic discontinuity with uncontained loss of bone stock (types III-V Gross and Saleh classification). Treatment of these defects with the SAI leads to a higher incidence of aseptic loosening requiring re-revisions. Further observation is required to assess the effectiveness of using the CMAI and SAI in the long-term follow-up period.

Comparative analysis of pathogen structure in patients with PJI after primary total hip and knee arthroplasty.

BACKGROUND: Microbiological profile of pathogens causing periprosthetic joint infection (PJI) after primary total hip (THA) and knee (TKA) arthroplasty varies in different regions, clinics and even departments. The objective of this study was to analyze the pathogen structure in patients with PJI after primary THA and TKA and its influence on the effectiveness of the infection eradication after two-stage reimplantation. MATERIALS AND METHODS: We collected the retrospective data of 364 patients-161 with PJI after primary TKA (113 treated in two stages 48 with failure after spacer implantation) and 203 patients with infected THA (127 after successful two-stage reimplantation and 76 with PJI recurrence after the first stage) within the time period from January 2012 to December 2017, treated with two-stage protocol in the single center. A comparative analysis of pathogen structure was performed between cohorts of patients with hip and knee PJI. A subanalysis was made between the subsets comprised from patients with successful two-stage treatment and the subsets with failure to treat the infection. RESULTS: Staphylococcus epidermidis was the most commonly identified pathogen in the full hip and knee cohorts: 30.1% and 32.5%, respectively. However, the percentage of methicillin-resistant Staphylococcus epidermidis (MRSE) among all S. epidermidis isolates was higher in the hip cohort-50% compared with 35% in the knee cohort (p = 0.073). Other coagulase-negative Staphylococci were more common to patients with PJI after primary TKA-10.3% compared with 5% (p < 0.02). Streptococcus sp. caused hip PJI in a larger percentage of cases than in knee PJI (p < 0.01)-7% and 2%, respectively (p < 0.01). Polymicrobial associations were significantly more common in hip PJI compared to knee PJI: 45.3% and 14% of cases, respectively (p < 0.001). The presence of polymicrobial infection significantly raised the risk of PJI recurrence [OR 2 (95% CI from 1.24 to 3.24)] in knee PJI patients and reduced the effectiveness of infection eradication from 73.9% to 47.8%. CONCLUSION: Comparative analysis showed significant differences in the structure of PJI pathogens in the hip and knee. These findings are useful when choosing treatment strategies and empirical antibiotics regimens, in the management of patients with PJIs after primary hip and knee arthroplasty.

Functional outcome of two-stage reimplantation in patients with periprosthetic joint infection after primary total knee arthroplasty.

INTRODUCTION: Two-stage reimplantation in patients with chronic periprosthetic joint infection (PJI) after total knee arthroplasty (TKA) with the use of either articulating or static antibiotic-loaded spacers during the first step is considered to be the golden standard in orthopaedics. THE AIM OF THE STUDY: The aim of the study was to evaluate the correlation of spacer type with the infection elimination rate as well as functional outcomes after two-staged revision TKA in patients with PJI. MATERIALS AND METHODS: The cohort comprised 161 patients who were treated for PJI after TKA during a period from January 2007 to December 2015. After the exclusion of patients with severe bone defects (AORI 2B or 3), 104 were left for the analysis: 72 patients with articulating and 32 with static spacers. The overall patient mean age was 62 years old (95% CI, 30-84): 73 for females, 31 for males. The outcomes were evaluated after three, six and 12 months using the American Knee Society Score (KSS) and EQ-5D. Only 92 patients were available for observation: 25 with static and 67 with articulating spacers. RESULTS: One year after the surgery, patients with articulating spacers demonstrated significantly higher mean KSS and function scores in comparison to patients with static spacers (90.4, 77.3 and 78.5, 67.8, respectively (p < 0.05)). The range of motion was also significantly better in patients with articulating spacers: 104.9° in comparison to 93.9° (р < 0.0001). The final EQ-5D score was comparable in both groups (0.82, 73.1 in articulating and 0.82, 72.6 in static spacers). CONCLUSION: The two-stage revision TKA for PJI using articulating spacers in comparison to the static ones provides better infection eradication rate as well as functional outcomes and improved quality of life.

Experimental study of the installation acetabular component with uncoverage in arthroplasty patients with severe developmental hip dysplasia.

PURPOSE: The purpose of this study was stimation of optimal percentage of lateral uncoverage of the acetabular component during total hip arthroplasty for patients with severe developmental hip dysplasia. METHODS: Mathematical computer modeling based on the finite element technique and the mechanical experiment were performed. Critical values of uncoverage enabling safe primary fixation of acetabular component were estimated in designed models. RESULTS: Using the finite element technique and the mechanical experiment on pelvis models, a possibility of mounting an acetabular component with moderate uncoverage within 25% without screws and with significant uncoverage to 35% with an additional two-screw fixation was demonstrated. CONCLUSIONS: This study provides additional guidance on optimal acetabular uncoverage assessment and fixation methods of surgeons performing THA on patients with DDH.

Risk factors and a prognostic model of hip periprosthetic infection recurrence after surgical treatment using articulating and non-articulating spacers.

PURPOSE: The purpose of this study was evaluation of the efficacy of the first step of a two-stage procedure for treatment of hip prosthetic joint infection (PJI) using articulating and non-articulating spacers as well as development of a prediction model and prognostic score for infection recurrence. METHODS: In a cohort of 217 patients treated for PJI of the hip, demographic characteristics, clinical symptoms, body temperature, body mass index (BMI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC), microbiological cultures and the type of the spacer used were retrospectively analyzed for association with the recurrence of PJI. RESULTS: Patients with infection recurrence had increased levels of ESR and CRP (P < 0.001) together with higher BMI and shorter infection manifestation period after previous surgery (P < 0.05). Among these patients, there was no significant difference of clinical characteristics between subjects with articulating and non-articulating spacers. Microbial associations were more often identified in patients with recurrent infection (50 %, P < 0.01) where Gram-negative bacteria were predominant (61.5 %, P < 0.01). These patients had higher percentage of Acinetobacter sp. and P. aeruginosa isolates (28.2 %, P < 0.01). CONCLUSIONS: Efficacy of the first step of two-stage revision was 64.1 %. Placement of either articulating or non-articulating spacers did not influence recovery from PJI. Laboratory values of ESR, CRP, BMI and the type of previous surgery were identified as main factors that affect outcomes of the two-stage procedure. A prognostic model with the calculation of a total risk score for PJI recurrence was developed.

Failure of the first step of two-stage revision due to polymicrobial prosthetic joint infection of the hip.

BACKGROUND: The unsuccessful treatment of prosthetic joint infection (PJI) with two-stage revision leads to infection recurrence. The objectives of the study were to assess the clinical and demographic characteristics of patients with polymicrobial PJI, and to evaluate the role of the microbial profile involved in PJI in the risk of infection recurrence after the first step of two-stage revision surgery. MATERIALS AND METHODS: A retrospective analysis of 189 cases of culture-positive PJI following total hip replacement over a 5-year period was performed. The demographic characteristics of patients, clinical symptoms, microbiology cultures of intraoperative biopsies, laboratory values of C-reactive protein (CRP), white blood cell count and erythrocyte sedimentation rate were analyzed. Patients were divided into two groups-135 with monomicrobial and 54 with polymicrobial infection. RESULTS: Of all patients, 68.9 % in the monomicrobial and 83.3 % in the polymicrobial group had a body mass index >25 kg/m2 (p = 0.05). The median CRP values were 5.7 mg/L (IQR 4.0-10.0 mg/L) in the monomicrobial compared to 8.8 mg/L (IQR 5.0-27 mg/L) in the polymicrobial group (p = 0.01). The percentage of successful outcomes was 27.8 % in patients with microbial associations (p < 0.0001). Gram-negative pathogens caused polymicrobial PJI in 61.5 % of cases with infection recurrence (OR 4.4; 95 % CI 1.18-16.37; p = 0.03). CONCLUSIONS: Overweight and obese patients or those with elevated CRP had a greater risk of polymicrobial PJI. They were predisposed to recurrence of infection after the first step of two-stage revision. An unsuccessful outcome was more likely in cases with polymicrobial infection compared to those with monomicrobial infection. In addition, the presence of multidrug-resistant strains of Gram-negative bacteria substantially increased the risk of PJI treatment being unsuccessful. LEVEL OF EVIDENCE: Level III, therapeutic study.

Intrawound navigation for custom-made acetabular component in revision total hip arthroplasty: Does it improve implant positioning?

Background: The number of hip revisions makes up over 12 % of all hip arthroplasty cases. For large acetabular defects custom-made acetabular component (CMAC) are required. Rates of malposition of CMACs are highly variable. Our study aims to develop a readily available, reliable and easily reproducible method for positioning of the CMAC. We tried to answer the following questions: 1) how often does the postoperative position of the implant corresponds to the planned one; 2) is the use of intrawound navigation improve the precision of acetabular implant position. Methods: This was a single-center observational cohort study and included two groups: the experimental group (use of 3D navigation for implant positioning) and the control group (no navigation use). All the patients were scheduled for acetabular revision surgery with custom-made 3D-printed acetabular components. All surgeries took place between 2016 and 2020. Results: 25 % freehand group, 85 % implants in the navigation group matched accuracy positioning criteria. The relative risk of malposition was significantly higher without the intraoperative navigation, with 5 times greater risk of malpositioning in the freehand group versus the navigation group. Conclusion: Navigation method allows planning of the implant and reamer sizes for optimal bone preparation and preservation. It provides easier implantation of the complex implant with reliable, stable primary fixation in massive bone defects. It reliably decreases malposition rate, allowing for implant placement in a proper position with sufficient bone-implant contact. Further research is needed to determine the relationship between CMAC position accuracy and long-term clinical and radiographic outcomes.

The experimental study of tissue integration into porous titanium implants.

INTRODUCTION: Due to a lack of uniform shapes and sizes of bone defects in hip and knee joint pathology, their fixing could benefit from using individually manufactured 3D-printed highly porous titanium implants. The objective of this study was to evaluate the extent of bone and muscle tissue integration into porous titanium implants manufactured using additive technology. MATERIALS AND METHODS: Porous and non-porous titanium plates were implanted into the latissimus dorsi muscle and tibia of 9 rabbits. On days 1, 60 and 90 animals were examined with x-rays. On day 60 histological tests were carried out. On day 90 the tensile strength at the implant-tissue interface was tested. RESULTS: Histological analysis of muscle samples with porous titanium implants showed integration of connective tissue and blood vessels into the pores. Bone defect analysis demonstrated bone ingrowth into the pores of titanium with a minimal amount of fibrous tissue. The tensile strength of the muscular tissue attachment to the porous titanium was 28 (22-30) N which was higher than that of the control group 8.5 (5-11) N. Bone tissue attachment strength was 148 (140-152) N in the experimental group versus 118 (84-122) N in the control group. CONCLUSIONS: Using additive technology in manufacturing 3D-printed highly porous titanium implants improves bone and muscle integration compared with the non-porous material of the control group. This could be a promising approach to bone defect repair in revision and reconstruction surgery.

Isolation of Human Osteoblast Cells Capable for Mineralization and Synthetizing Bone-Related Proteins In Vitro from Adult Bone.

The culture of osteoblasts (OB) of human origin is a useful experimental model in studying bone biology, osteogenic differentiation, functions of bone proteins, oncological processes in bone tissue, testing drugs against bone desires, and many other fields. The purpose of the present study is to share a workflow that has established the conditions to efficiently isolate and grow OB cells obtained from surgically removed bones from human donors. The protocol described here also shows how to determine cell phenotype. Here we provide characteristics of cells isolated by this protocol that might help researchers to decide if such OB are suitable for the purposes of their study. Osteoblasts isolated from collagenase-treated explants of adult bones are able to proliferate and keep their phenotype in culture. OB cells have high synthetic properties. They express osteomarkers, such as RUNX2, osteocalcin, BMP2, and osteopontin both in control conditions and in an osteogenic medium that could be estimated by qPCR and immunocytochemical staining and by Western blotting. Induction of osteogenic differentiation does not dramatically influence the synthetic properties of OB cells, while the cells gain the ability to extracellular mineralization only in an osteogenic medium.