Search

Background: Periprosthetic osteolysis after total ankle arthroplasty (TAA) is a challenging problem. This study aimed to evaluate the prevalence of and predisposing factors for osteolysis and its effects on clinical outcomes.Methods: We enrolled 236 patients (250 ankles) who underwent primary TAA using a mobile-bearing HINTEGRA prosthesis, with a mean follow-up of 83.5 months (range, 36 to 182 months), and subsequently divided them into 2 groups: the osteolysis group (79 ankles) and non-osteolysis group (171 ankles). Clinical and radiographic outcomes were compared between the 2 groups, and a bivariable logistic regression analysis was performed to identify predisposing factors for the development of osteolysis.Results: In the osteolysis group (31.6% of the 250 ankles), the mean time of detection was 28.8 months postoperatively. Forty of these ankles were closely monitored without surgical treatment. Another 29 ankles underwent bone grafting and exchange of the polyethylene inlay, and the remaining 10 ankles underwent revision TAA or arthrodesis. All clinical outcome variables were significantly lower in patients with osteolysis, compared with those without osteolysis, at the final follow-up (p < 0.05). In the investigation of predisposing factors, only rheumatoid arthritis was identified as having a significant association with an increased prevalence of osteolysis (p = 0.030).Conclusions: This study demonstrated that the prevalence of periprosthetic osteolysis after TAA was considerable and that the development of osteolysis negatively affected the clinical outcome. Therefore, the prevention and appropriate treatment of osteolysis are crucial for the satisfactory long-term survival of TAA.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

The LIM-homeodomain transcription factor Lmx1b plays a key role in body pattern formation during development. Although Lmx1b is essential for the normal development of multiple tissues, its regulatory mechanism in bone cells remains unclear. Here, we demonstrated that Lmx1b negatively regulates bone morphogenic protein 2 (BMP2)-induced osteoblast differentiation. Overexpressed Lmx1b in the osteoblast precursor cells inhibited alkaline phosphatase (ALP) activity and nodule formation, as well as the expression of osteoblast maker genes, including runt-related transcription factor 2 (Runx2), alkaline phosphatase (Alpl), bone sialoprotein (Ibsp), and osteocalcin (Bglap). Conversely, the knockdown of Lmx1b in the osteoblast precursors enhanced the osteoblast differentiation and function. Lmx1b physically interacted with and repressed the transcriptional activity of Runx2 by reducing the recruitment of Runx2 to the promoter region of its target genes. In vivo analysis of BMP2-induced ectopic bone formation revealed that the knockdown of Lmx1b promoted osteogenic differentiation and bone regeneration. Our data demonstrate that Lmx1b negatively regulates osteoblast differentiation and function through regulation of Runx2 and provides a molecular basis for therapeutic targets for bone diseases. [ABSTRACT FROM AUTHOR]

Periprosthetic osteolysis is a common complication following total ankle arthroplasty (TAA). However, understanding of osteolysis volume and distribution is still evolving, undermining efforts to reduce the incidence of osteolysis via bone remodeling. We obtained data on the characteristics of osteolysis developing within the distal tibia and talus after TAA. Three-dimensional computed tomography (3D-CT) reconstructions of 12 patients who underwent HINTEGRA TAA were performed. We identified 27 volumes of interest (VOIs) in the tibia and talus and used statistical methods to identify the characteristics of osteolysis in the VOIs. The osteolysis volume was significantly larger in the talus than in the tibia (162.1 ± 13.6 and 54.9 ± 6.1 mm3, respectively, p = 0.00). The extent of osteolysis within the peri-prosthetic region was greater than within other regions (p < 0.05). Particularly, in the talus, the region around the talar pegs exhibited 24.2 ± 4.5% more osteolysis than any other talar region (p = 0.00). Our results may suggest that extensive osteolysis within the peri-prosthetic region reflects changes in stress flow and distribution, which vary according to the design and placement of the fixation components. This is the first study to report 3D osteolysis patterns after TAA. Careful planning of TAA design improvements may reduce the incidence of osteolysis. Our results will facilitate the further development of TAA systems. [ABSTRACT FROM AUTHOR]

Background: Modern total ankle arthroplasty (TAA) prostheses are uncemented press-fit designs whose stability is dependent on bone ingrowth. Preoperative insufficient bone density reduces initial local stability at the bone-implant interface, and we hypothesized that this may play a role in periprosthetic osteolysis. We aimed to investigate the preoperative bone density of the distal tibia and talus and compare these in patients with and without osteolysis. Methods: We enrolled 209 patients (218 ankles) who underwent primary TAA using the HINTEGRA prosthesis. The overall mean follow-up duration was 66 (range, 24-161) months. The patients were allocated into 2 groups according to the presence of periprosthetic osteolysis: the osteolysis group (64 patients, 65 ankles) and nonosteolysis group (145 patients, 153 ankles). Between the 2 groups, we investigated and compared the radiographic outcomes, including the Hounsfield unit (HU) value around the ankle joint and the coronal plane alignment. Results: HU values of the tibia and talus measured at 5 mm from the reference points were higher than those at 10 mm in each group. However, comparing the osteolysis and nonosteolysis groups, we found no significant intergroup difference in HU value at every measured level in the tibia and talus (P >.05). Concerning the coronal plane alignment, there were no significant between-group differences in the tibiotalar and talar tilt angles (P >.05). Conclusion: Patients with osteolysis showed similar preoperative bone density of the distal tibia and talus compared with patients without osteolysis. Our results suggest that low bone density around the ankle joint may not be associated with increased development of osteolysis. Level of Evidence: Level III, retrospective cohort study. [ABSTRACT FROM AUTHOR]

Background: Arthroscopic microfracture for osteochondral lesions of the talus (OLT) has shown good functional outcomes. However, some studies have reported that functional outcomes deteriorate over time after surgery. Purpose: To use various functional scoring systems to evaluate functional outcomes in a large sample of patients with OLT treated by arthroscopic microfracture. Study Design: Case series; Level of evidence, 4. Methods: The study cohort consisted of 165 ankles (156 patients) that underwent arthroscopic microfracture for small to mid-sized OLT. The mean lesion size was 73 mm2 (range, 17-146 mm2), and the mean follow-up period was 6.7 years (range, 2.0-13.6 years). The Foot and Ankle Outcome Score (FAOS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, visual analog scale (VAS) for pain, and 36-Item Short Form Health Survey (SF-36) were used to compare the functional outcomes between the preoperative and final follow-up assessments. Results: The mean FAOS significantly improved in regard to all subscores (P <.001). The AOFAS ankle-hindfoot scale showed an improvement from 71.0 points (range, 47.0-84.0) preoperatively to 89.5 points (range, 63.0-100) at the final follow-up (P <.001). The VAS score showed an improvement from 6.2 points (range, 4.0-9.0) preoperatively to 1.7 points (range, 0-6.0) at the final follow-up (P <.001). The mean SF-36 score improved from 62.4 points (range, 27.4-76.6) preoperatively to 76.2 points (range, 42.1-98.0) at the final follow-up (P <.001). Among 165 ankles, 22 ankles (13.3%) underwent repeat arthroscopic surgery for evaluation of repaired cartilage status. Conclusion: Arthroscopic microfracture showed good functional outcomes and improved quality of life with maintenance of satisfactory outcomes at a mean follow-up of 6.7 years. Therefore, arthroscopic microfracture seems to be reliable as a first-line treatment for OLT at an intermediate-term follow-up. [ABSTRACT FROM AUTHOR]

Background: Arthroscopic microfracture is considered the primary treatment strategy for osteochondral lesions of the talus and has been shown to provide successful outcomes. However, deterioration of clinical outcomes and fibrocartilage infill over time is now a recognized concern. The purpose of the present study was to evaluate the outcomes related to cartilage repair tissue after microfracture with use of second-look arthroscopy and magnetic resonance imaging (MRI) and to compare these findings with functional outcomes.Methods: Twenty-five patients underwent second-look arthroscopy and MRI at a mean of 3.6 years (range, 2.2 to 8.1 years) after microfracture. Second-look arthroscopic findings were assessed according to the system of the International Cartilage Repair Society (ICRS). MRI was evaluated postoperatively with use of the magnetic resonance observation of cartilage repair tissue (MOCART) score. Clinical outcomes were determined with use of the Foot and Ankle Outcome Score (FAOS), the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale, and the Short Form-36 (SF-36) score.Results: On second-look arthroscopy, 9 ankles (36%) were still abnormal according to the ICRS overall repair grades. The average postoperative MOCART score was 67.8 (range, 30 to 95), with good association with functional outcome. In addition, 6 patients (24%) had a mismatch between the MRI and second-look arthroscopic findings. Significant improvements were observed in all functional outcome categories between the preoperative and latest follow-up evaluations (p < 0.001). The mean FAOS scores for ICRS repair grades I and II (n = 16) and grades III and IV (n = 9) were 86.8 and 75.6, respectively. There was a significant correlation between FAOS scores and ICRS grades (p = 0.004).Conclusions: Second-look arthroscopic results revealed that 36% of lesions were incompletely healed and had inferior quality of repair tissue compared with that of native cartilage at a mean of 3.6 years, although arthroscopic microfracture provided functional improvements. Magnetic resonance analysis demonstrated some limitations in comparison with arthroscopy for the evaluation of cartilage repair. Therefore, second-look arthroscopy has an important role in accurately assessing the status of the cartilage repair tissue beyond the use of the MOCART score and functional outcomes.Level Of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]

Background: A preoperative severe coronal plane deformity of >20° has been considered a contraindication for total ankle arthroplasty. We aimed to evaluate whether outcomes of total ankle arthroplasty in ankles with severe coronal plane deformity (20° to 35° of varus or valgus) are comparable with those with moderate deformity (5° to 15° of varus or valgus).Methods: A total of 148 consecutive ankles (142 patients) that underwent primary total ankle arthroplasty using the HINTEGRA prosthesis were included. The overall mean follow-up duration was 74 months (range, 24 to 160 months). We divided all patients into 2 groups according to the preoperative coronal plane tibiotalar angle: the severe group (36 patients, 41 ankles) and the moderate group (106 patients, 107 ankles). Clinical and radiographic outcomes were analyzed for intergroup differences, and multivariable regression was used to adjust for baseline characteristics. Patients in each group showed similar characteristics in mean age, sex, mean body mass index, and median follow-up duration.Results: At a mean follow-up of 74 months, we found no significant intergroup difference in the Ankle Osteoarthritis Scale pain and disability score, American Orthopaedic Foot & Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, visual analog scale pain score, or ankle range of motion (p > 0.05). However, the final tibiotalar angle, talar tilt angle, and number of outliers were greater in the severe group (p < 0.05). Complication rates did not show a significant difference between the 2 groups (p > 0.05). The overall survival probability of the implant was 91.3% (92.3% in the severe group and 90.7% in the moderate group) (p = 0.354).Conclusions: Total ankle arthroplasty in ankles with preoperative severe coronal plane deformity showed satisfactory and comparable clinical outcomes without increasing complication rates relative to those with moderate deformity in the intermediate-term follow-up. Our results suggested that total ankle arthroplasty may be considered in ankles with deformity of >20°.Level Of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence. [ABSTRACT FROM AUTHOR]