Characterisation of osteophytes as an autologous bone graft source: An experimental study in vivo and in vitro

Effect of lateral hinge fractures for bone union and clinical outcomes following opening-wedge distal tibial tubercle osteotomy in comparison with opening-wedge high tibial osteotomy

PURPOSE

Although the effects of lateral hinge fractures (LHF) on bone union and clinical outcomes after opening-wedge high tibial osteotomy (OWHTO) have been established, the effects of LHF after opening-wedge distal tibial tubercle osteotomy (OWDTO) are unclear. We hypothesised that LHF after OWDTO would be associated with delayed bone union and result in poorer clinical outcomes than expected for LHF after OWHTO.

METHODS

This study enrolled 100 patients, with 50 OWDTO patients (18 men; mean age, 63.2 years) and 50 OWHTO patients compared based on the propensity score matched analysis. The effect of LHF on bone union was compared between the groups. Clinical outcomes were assessed using the Lysholm score and the Knee Injury and Osteoarthritis Outcome Score (KOOS) at the mean follow-up of 28 months.

RESULTS

There was no between-group difference in the incidence rate of LHF. However, the rate of bone union at the anterior flange in the presence of an LHF was significantly lower in the OWDTO (26%) than in the OWHTO (80%) 3 months postoperatively (p < 0.05), but no difference was observed 12 months postoperatively. The Lysholm score was significantly lower for patients with LHF following OWDTO than for OWDTO patients without LHF or OWHTO patients with/without LHF 3 and 12 months postoperatively (p < 0.001); Lysholm score and KOOS were not different at the final follow-up.

CONCLUSIONS

LHF after OWDTO was associated with delayed bone union and poor clinical outcomes until 12 months. This information can guide decisions regarding the indications and the management of patients after OWDTO.

LEVEL OF EVIDENCE

IV.

Autologous osteophyte grafting for ankle arthrodesis

Purpose: Various graft sources had been identified to facilitate gap-filling in ankle arthrodesis procedures with related articular defects. This was a preliminary study with the aim of analyzing the efficacy and feasibility of using autologous osteophyte as a grafting source. Methods: Retrospective evaluation of ten patients having ankle arthrodesis procedure using identical anterior approach and plate fixation technique was conducted. Basic anthropometric measurements and underlying disease were recorded. Functional outcome and fusion rate were assessed at a 12-month post-surgery follow-up visit. Results: The underlying diseases include primary osteoarthritis (OA), post-traumatic OA, rheumatoid arthritis, and Charcot arthropathy. The patient’s age mean was 56.6 years (range 36–71 years), and BMI varied from 17.9 kg/m² to 29.3 kg/m². Nearly all patients had improved functional outcomes as described by foot and ankle ability measure (FAAM) score and fusion rate as described by modified radiographic union score for tibia (RUST). One patient had failed surgery due to implant failure with diminished protective foot sensory. Conclusion: Osteophytes from the distal tibia and talar neck were a viable source of bone graft, especially for ankle arthrodesis using anterior approach among various ages and BMI, in which the surgeons would not need additional incision for graft harvesting.

The Potential of Bone Debris as a Bioactive Composite for Bone Grafting in Arthroscopic Ankle Arthrodesis

Arthroscopic ankle arthrodesis (AAA) has advantages of being less invasive and achieving a high bone union rate. However, there are still some nonunion or delayed union cases, especially those of high-grade deformity. During AAA, curettage of the subchondral bone using an abrader burr provides bone debris, and there is the possibility of bone debris being used as autograft to improve bone union. The purpose of this study is to analyze bone debris histologically, and the effect of its implantation on bone union of AAA. Bone debris from 6 patients was collected during AAA. Bone debris/atelocollagen composite was made and cultured for 4 weeks. Histological analyses were performed before and after culture. Twenty-six patients with AAA were divided into 2 groups with or without bone debris implantation, and the time to union after surgery was evaluated. In histological analysis of bone debris/atelocollagen composite, bone debris contained bone, cartilage and synovium fragment at time 0. After 4 weeks of culture, osteocalcin positive cells migrated and proliferated in the gel. Ki67 positive cells significantly increased after culture. In clinical cases, time to union was significantly shorter in the bone debris group (9.3 ± 1.3 weeks) than that in the control (12.4 ± 3.1 weeks). This study showed that bone debris contained the osteochonductive and osteoinductive properties, and there is the potential for its implantation into the ankle joint to improve bone union in ankle arthrodesis.

Distal Tibial Tuberosity Arc Osteotomy in Open-Wedge Proximal Tibial Osteotomy to Prevent Patella Infra

Open-wedge high tibial osteotomy is considered to be an effective surgical intervention for medial compartmental knee osteoarthritis. However, patella infra, which has been reported to be a result of tuberosity distalization after open-wedge high tibial osteotomy, changes the native patellofemoral biomechanics. This could raise abnormal patellofemoral contact stresses, which might be the trigger of patellofemoral arthrosis. To minimize the reduction in patellar height, we have developed a technique called open-wedge distal tuberosity tibial osteotomy. The benefits of this technique include increased bone-to-bone contact of the distal tuberosity cut surface after correction by cutting an arc osteotomy around the hinge position, which is the center of rotation. This technique also provides cortical support at the anterior osteotomy site without additional bone defect and, therefore, may be advantageous against weight-bearing stress on the osteotomy site. In all, open-wedge distal tuberosity tibial osteotomy could potentially be a unique open-wedge osteotomy that eliminates the risk for postoperative patellofemoral osteoarthritis and also could theoretically encourage rapid healing of the osteotomy, which could lead to early return to full physical activity.

Microstructure of osteophytes in medial knee osteoarthritis

Knee osteoarthritis (OA) is one of the most common musculoskeletal diseases and osteophytes area frequent radiographic feature of knee OA. The osteophyte structure in knee OA, however, is not well elucidated. This study aimed to clarify the three-dimensional microstructural characteristics of osteophytes in the medial compartment of the knee in knee OA patients using micro-computed tomography (micro-CT). We hypothesized that the morphology of osteophytes would differ from that of the neighboring normal cancellous bones. Ten medial compartment knee OA patients with Kellgren-Lawrence grade 4 severity were enrolled in the study, and all patients underwent total knee arthroplasty. Osteophytes and cancellous bones were obtained from the medial femoral condyle. The three-dimensional trabecular bone microstructure was analyzed by quantitative micro-CT using image analysis software. The trabecular bone volume fraction and trabecular number were significantly lower in osteophytes than in cancellous bones. Consistently, trabecular separation was significantly higher in osteophytes. Osteophytes exhibited disorganized trabecular orientation, trabecular perforation, disruption, and complete disconnection. These findings suggest that osteophytes are functionally fragile.

Ag-loaded MgSrFe-layered double hydroxide/chitosan composite scaffold with enhanced osteogenic and antibacterial property for bone engineering tissue

Bone tissue engineering scaffolds for the reconstruction of large bone defects should simultaneously promote osteogenic differentiation and avoid postoperative infection. Herein, we develop, for the first time, Ag-loaded MgSrFe-layered double hydroxide/chitosan (Ag-MgSrFe/CS) composite scaffold. This scaffold exhibits three-dimensional interconnected macroporous structure with a pore size of 100-300 μm. The layered double hydroxide nanoplates in the Ag-MgSrFe/CS show lateral sizes of 200-400 nm and thicknesses of ∼50 nm, and the Ag nanoparticles with particle sizes of ∼20 nm are uniformly dispersed on the scaffold surfaces. Human bone marrow-derived mesenchymal stem cells (hBMSCs) present good adhesion, spreading, and proliferation on the Ag-MgSrFe/CS composite scaffold, suggesting that the Ag and Sr elements in the composite scaffold have no toxicity to hBMSCs. When compared with MgFe/CS composite scaffold, the Ag-MgSrFe/CS composite scaffold has better osteogenic property. The released Sr²⁺ ions from the composite scaffold enhance the alkaline phosphatase activity of hBMSCs, promote the extracellular matrix mineralization, and increase the expression levels of osteogenic-related RUNX2 and BMP-2. Moreover, the Ag-MgSrFe/CS composite scaffold possesses good antibacterial property because the Ag nanoparticles in the composite scaffold effectively prevent biofilm formation against S. aureus. Hence, the Ag-MgSrFe/CS composite scaffold with excellent osteoinductivity and antibacterial property has a great potential for bone tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 863-873, 2018.