Bone grafting for periprosthetic bone cysts following total ankle arthroplasty.

Aims: The purpose of this study was to assess the success rate and functional outcomes of bone grafting for periprosthetic bone cysts following total ankle arthroplasty (TAA). Additionally, we evaluated the rate of graft incorporation and identified associated predisposing factors using CT scan. Methods: We reviewed a total of 37 ankles (34 patients) that had undergone bone grafting for periprosthetic bone cysts. A CT scan was performed one year after bone grafting to check the status of graft incorporation. For accurate analysis of cyst volumes and their postoperative changes, 3D-reconstructed CT scan processed with 3D software was used. For functional outcomes, variables such as the Ankle Osteoarthritis Scale score and the visual analogue scale for pain were measured. Results: Out of 37 ankles, graft incorporation was successful in 30 cases. Among the remaining seven cases, four (10.8%) exhibited cyst re-progression, so secondary bone grafting was needed. After secondary bone grafting, no further progression has been noted, resulting in an overall 91.9% success rate (34 of 37) at a mean follow-up period of 47.5 months (24 to 120). The remaining three cases (8.1%) showed implant loosening, so tibiotalocalcaneal arthrodesis was performed. Functional outcomes were also improved after bone grafting in all variables at the latest follow-up (p < 0.05). The mean incorporation rate of the grafts according to the location of the cysts was 84.8% (55.2% to 96.1%) at the medial malleolus, 65.1% (27.6% to 97.1%) at the tibia, and 81.2% (42.8% to 98.7%) at the talus. Smoking was identified as a significant predisposing factor adversely affecting graft incorporation (p = 0.001). Conclusion: Bone grafting for periprosthetic bone cysts following primary TAA is a reliable procedure with a satisfactory success rate and functional outcomes. Regular follow-up, including CT scan, is important for the detection of cyst re-progression to prevent implant loosening after bone grafting.

Effect of diabetes mellitus on the outcomes of total ankle arthroplasty: is controlled diabetes mellitus a risk factor?

BACKGROUND: It is still uncertain whether diabetes mellitus (DM) is a risk factor for poor outcomes and increased complications after total ankle arthroplasty (TAA). The objective of this study was to compare clinical outcomes and complication rates of TAA in patients with and without DM. METHODS: This study enrolled patients with symptomatic end-stage ankle osteoarthritis with a minimum follow-up period of 24 months after TAA. A total of 252 patients (266 ankles) were classified into two groups according to the presence of DM: (1) DM group (59 patients, 67 ankles) and (2) non-DM group (193 patients, 199 ankles). We defined controlled diabetes as (1) HbA1c level < 7.0%, or (2) fasting glucose level < 130 mg/dL with HbA1c level ≥ 7.0% for hospitalization period. Clinical outcomes data (Ankle Osteoarthritis Scale, American Orthopedic Foot and Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, and visual analog scale for pain) were compared preoperatively and at the final follow-up between the two groups. Complications following TAA were also compared between the two groups. RESULTS: All clinical variables had improved in both groups by the final follow-up (mean follow-up = 77.8 months). There was no significant difference in any clinical variable between the two groups at the final follow-up (P > 0.05). Of the 266 ankles, 73 ankles (19 in the DM group, 54 in the non-DM group) developed periprosthetic osteolysis. Although the DM group showed a higher prevalence of aseptic loosening or subsidence, the difference between the two groups was not statistically significant (P = 0.236). CONCLUSIONS: In the intermediate-term follow-up, TAA in patients with controlled DM showed clinical outcomes and complication rates comparable to patients without DM. Our results suggest that TAA can be done safely in diabetic patients if the DM is controlled in the perioperative period. LEVEL OF EVIDENCE: Therapeutic Level III.

LIM Homeobox Transcription Factor 1-ß Expression is Upregulated in Patients with Osteolysis after Total Ankle Arthroplasty and Inhibits Receptor Activator of Nuclear Factor-κB Ligand-Induced Osteoclast Differentiation in Vitro.

BACKGROUND: Osteolysis is one of the most common problems that occurs after total hip and knee arthroplasty and has recently become a significant problem after total ankle arthroplasty (TAA). In this study, we investigated the role of LIM homeobox transcription factor 1-ß (Lmx1b) in osteoclast differentiation. By evaluating the expression profiles associated with osteolysis following TAA treatment, Lmx1b was found to be differentially expressed in patients with osteolysis after TAA. METHODS: To identify the important genes associated with osteolysis after TAA, RNA sequencing was performed by analyzing 8 patient samples: 5 primary TAA samples (control group) and 3 TAA samples revised for flexion instability (osteolysis group). By analyzing the differentially expressed genes and gene ontologies, Lmx1b expression was found to be upregulated in the osteolysis group compared to that in the control group. Focusing on the role of Lmx1b in bone cells, Lmx1b was overexpressed by a retrovirus in osteoclast precursor cells. The cultured cells were stained with tartrate-resistant acid phosphatase, and the expression of osteoclast-related genes was analyzed using real-time polymerase chain reaction. RESULTS: Lmx1b overexpression in osteoclast precursors suppresses osteoclast formation and resorptive activity. The expression of osteoclast marker genes was significantly reduced during osteoclast differentiation by Lmx1b overexpression. Furthermore, Lmx1b is associated with nuclear factor of activated T cells 1 (NFATc1) and inhibited NFATc1 translocation into the nucleus. CONCLUSIONS: These results provide novel insights into the anti-bone resorptive effect of Lmx1b on osteolysis after TAA and may lead to the development of effective preventative and therapeutic strategies for peri-implant osteolysis.

Periprosthetic Osteolysis as a Risk Factor for Revision After Total Ankle Arthroplasty: A Single-Center Experience of 250 Consecutive Cases.

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.

Transcription Factor Lmx1b Negatively Regulates Osteoblast Differentiation and Bone Formation.

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.

Effects and Safety of Intra-Articular Sodium Hyaluronate Injection for the Treatment of Ankle Osteoarthritis: A Prospective Clinical Trial.

Various nonoperative treatments have been implemented to reduce pain and improve the quality of life in patients with ankle osteoarthritis. Among these treatments, intra-articular hyaluronate injection has proven efficacy and safety in patients with knee osteoarthritis. The purpose of this study was to evaluate the efficacy and complications of hyaluronate injection using various clinical scoring systems. This study included 37 patients with unilateral ankle osteoarthritis (grade 2 or 3 according to the Takakura classification) who did not respond to previous pharmacological treatment. 3 weekly hyaluronate injections (2 mL Hyruan Plus®) were administered. The efficacy of intra-articular hyaluronate injection was evaluated on the basis of patient-reported foot and ankle clinical assessment at a mean follow-up of 13.8 ± 8.3 (range 6-33) months. Ankle Osteoarthritis Scale scores for pain and disability, American Orthopedic Foot and Ankle Society ankle-hindfoot scores, and visual analog scale for pain significantly improved at the final follow-up compared to that before intra-articular hyaluronate injection (p ≤ .05). When patients were dichotomized according to age, sex, body mass index, symptom duration, and Takakura classification, all these factors were not related to clinical outcomes. This study suggests that 3 weekly intra-articular hyaluronate injections can be performed safely to reduce pain and improve function without serious complications in patients with early or intermediate-grade ankle osteoarthritis when patients inadequately respond to medication. Larger controlled studies are needed to clarify the effects of hyaluronate injection and identify patients who can benefit most from hyaluronate injection.

Comparison of 2-octyl cyanoacrylate skin adhesive and interrupted polypropylene sutures for wound closure in total ankle arthroplasty.

BACKGROUND: Adhesive skin materials have increasingly been used in orthopedic surgery. We aimed to compare the efficacy and safety of skin adhesive (2-octyl cyanoacrylate and polymer mesh, Dermabond Prineo) and interrupted polypropylene sutures for wound closure in patients undergoing total ankle arthroplasty (TAA). METHODS: We prospectively enrolled 107 consecutive patients (108 ankles) undergoing TAA and divided them into two groups: skin adhesive group (36 ankles) and suture group (72 ankles). The primary outcome assessment included wound complications and patient satisfaction for wound cosmesis. The secondary outcome assessment included duration of surgery, length of hospital stay, and the Ankle Osteoarthritis Scale (AOS) pain and disability score. RESULTS: There was one case of allergic contact dermatitis, three cases of wound dehiscence, and one case of superficial surgical site infection in the skin adhesive group. Among them, one case each with allergic contact dermatitis and wound dehiscence finally progressed to deep surgical site infection. Three cases of wound dehiscence were also reported in the suture group; however, there was no case of surgical site infection. Patient satisfaction for wound cosmesis was significantly higher in the skin adhesive group than in the suture group (p = 0.001). There was no statistically significant difference between the groups in terms of secondary outcomes (p > 0.05). CONCLUSIONS: Although the use of Dermabond Prineo showed better patient satisfaction for wound cosmesis, it showed significantly high wound complication rates and no other clinical benefits compared to interrupted polypropylene suture in TAA. Our results suggest that awareness of the possibility of wound complications is necessary when Dermabond Prineo is used in TAA.

IRF2 enhances RANKL-induced osteoclast differentiation via regulating NF-κB/NFATc1 signaling.

Interferon regulatory factors (IRFs) play roles in various biological processes including cytokine signaling, cell growth regulation and hematopoietic development. Although it has been reported that several IRFs are involved in bone metabolism, the role of IRF2 in bone cells has not been elucidated. Here, we investigated the involvement of IRF2 in RANKL-induced osteoclast differentiation. IRF2 overexpression in osteoclast precursor cells enhanced osteoclast differentiation by regulating the expression of NFATc1, a master regulator of osteoclastogenesis. Conversely, IRF2 knockdown inhibited osteoclast differentiation and decreased the NFATc1 expression. Moreover, IRF2 increased the translocation of NF-κB subunit p65 to the nucleus in response to RANKL and subsequently induced the expression of NFATc1. IRF2 plays an important role in RANKL-induced osteoclast differentiation by regulating NF-κB/NFATc1 signaling pathway. Taken together, we demonstrated the molecular mechanism of IRF2 in osteoclast differentiation, and provide a molecular basis for potential therapeutic targets for the treatment of bone diseases characterized by excessive bone resorption. [BMB Reports 2021; 54(9): 482-487].

Comparison of Preoperative Bone Density in Patients With and Without Periprosthetic Osteolysis Following Total Ankle Arthroplasty.

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.

Unrecognized tibial nerve injury in total-ankle arthroplasty: Two case reports.

RATIONALE: Tibial nerve injury is a sustainable but rare complication during total-ankle arthroplasty (TAA). We outlined 2 previously unreported cases of tibial nerve injury in TAA, including the prognoses and possible causes. PATIENT CONCERNS: First, a 63-year-old woman complained of a 5-month history of persistent tingling sensation and numbness on the medial and plantar aspects of her foot after TAA. Second, a 50-year-old woman complained of a 6-month history of tingling sensation and numbness on the plantar surface of her forefoot after TAA. DIAGNOSIS: Explorations were performed on suspicion of tarsal tunnel syndrome; however, both patients exhibited complete laceration of tibial nerve with neuroma formation. INTERVENTIONS: In both patients, we excised the neuroma and performed end-to-end nerve repair. OUTCOMES: The sensory disturbance of the sole considerably improved at long-term follow-up over 8 years after the neurorrhaphy procedures. LESSONS: Tibial nerve injury is rare following TAA, and is sometimes unrecognized or misdiagnosed. If tibial nerve injury is suspected, prompt surgical exploration should be performed; great precaution must also be taken to prevent injury of the tibial nerve during TAA.

Does gender influence the outcomes of total ankle arthroplasty in patients with ankle osteoarthritis?

BACKGROUND: Total ankle arthroplasty has progressed as a treatment option for patients with ankle osteoarthritis. However, no studies have been conducted to evaluate the effect of gender on the outcome. The purpose of the present study was to evaluate outcomes, survivorship, and complications rates of total ankle arthroplasty, according to gender differences. METHODS: This study included 187 patients (195 ankles) that underwent mobile-bearing HINTEGRA prosthesis at a mean follow-up of 7.5 years (range, 4 to 14). The two groups consisted of a men's group (106 patients, 109 ankles) and a women's group (81 patients, 86 ankles). Average age was 64.4 years (range, 45 to 83). RESULTS: Clinical scores on the Ankle Osteoarthritis Scale for pain and disability, and American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved and the difference was not statistically significant between the two groups at the final follow-up. There were no significant differences in complication rates and implant survivorship between the two groups. The overall survival rate was 96.4% in men and 93.4% in women at a mean follow-up of 7.5 years (p = 0.621). CONCLUSIONS: Clinical outcomes, complication rates, and survivorship of total ankle arthroplasty were comparable between men and women. These results suggest that gender did not seem to affect outcomes of total ankle arthroplasty in patients with ankle osteoarthritis. LEVEL OF EVIDENCE: Therapeutic level III.

Arthroscopic Microfracture for Osteochondral Lesions of the Talus: Second-Look Arthroscopic and Magnetic Resonance Analysis of Cartilage Repair Tissue Outcomes.

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.

Arthroscopic Microfracture for Osteochondral Lesions of the Talus: Functional Outcomes at a Mean of 6.7 Years in 165 Consecutive Ankles.

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.

Outcomes of Total Ankle Arthroplasty in Ankles with >20° of Coronal Plane Deformity.

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.

Comparison of Intermediate-term Outcomes of Total Ankle Arthroplasty in Primary and Ligamentous Post-traumatic Osteoarthritis.

BACKGROUND: Ankle ligamentous injuries without fracture can result in end-stage ligamentous post-traumatic osteoarthritis, which may cause ligamentous imbalance after total ankle arthroplasty (TAA). However, outcomes of TAA in these patients are not well known. The purpose of this study was to evaluate intermediate-term clinical and radiographic outcomes of TAA in patients with ligamentous post-traumatic osteoarthritis and compare them with results of TAA for patients with primary osteoarthritis. METHODS: We enrolled 114 patients (119 ankles) with consecutive primary TAA using HINTEGRA prosthesis at a mean follow-up duration of 6.0 years (range, 3-13). We divided all patients into 2 groups according to the etiology of osteoarthritis: (1) primary osteoarthritis group (69 ankles) and (2) ligamentous post-traumatic osteoarthritis group (50 ankles). RESULTS: There was no significant intergroup difference in mean Ankle Osteoarthritis Scale (AOS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Short Form-36 Physical Component Summary, visual analog scale pain score, ankle range of motion, or complications at the final follow-up. However, the final tibiotalar angle was less corrected to 4.2 degrees in the ligamentous post-traumatic osteoarthritis group compared to 2.7 degrees in the primary osteoarthritis group (P = .001). More concomitant procedures were required at the index surgery for the ligamentous post-traumatic osteoarthritis group (P = .001). The estimated 5-year survivorship was 93.4% (primary osteoarthritis group: 91.3%; ligamentous post-traumatic osteoarthritis group: 95.8%). CONCLUSIONS: Clinical outcomes, complication rate, and 5-year survivorship of TAA in ankles with primary and ligamentous post-traumatic osteoarthritis were comparable with intermediate-term follow-up. Our results suggest that TAA would be a reliable treatment in ankles with ligamentous post-traumatic osteoarthritis when neutrally aligned stable ankles are achieved postoperatively. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Comparison of Intermediate-Term Outcomes of Total Ankle Arthroplasty in Patients Younger and Older Than 55 Years.

BACKGROUND: Total ankle arthroplasty is often not recommended to younger patients with ankle arthritis because of their high functional demands. The purpose of this study was to compare intermediate-term clinical and radiographic outcomes and survivorship rates of total ankle arthroplasty between patients younger and older than 55 years. METHODS: A total of 117 consecutive patients (123 ankles) who underwent primary total ankle arthroplasty using Hintegra prosthesis with a mean follow-up of 78 months were enrolled and divided into 2 age groups: under 55 years (38 ankles; mean age 45 years) and over 55 years (85 ankles; mean age 65 years). RESULTS: Clinical scores of Ankle Osteoarthritis Scale pain and disability, American Orthopaedic Foot & Ankle Society ankle-hindfoot, Short Form-36 Physical Component Summary and Mental Component Summary, and visual analog scale were not significantly different between the 2 age groups at the final follow-up (P > .05). There were no significant differences in complications and survivorship rates between the two at a mean follow-up of 78 months (P > .05). CONCLUSIONS: Clinical and radiographic outcomes and survival rates of total ankle arthroplasty in patients under age of 55 years were satisfactory and comparable to those in patients older than 55 years in the intermediate-term follow-up. Therefore, total ankle arthroplasty may be considered as a viable treatment option in young patients with end-stage ankle arthritis. LEVEL OF EVIDENCE: Level III, comparative series, therapeutic.

Importance of postoperative sesamoid reduction on the outcomes of proximal chevron osteotomy for moderate to severe hallux valgus deformity.

BACKGROUND: The purpose of this study was to compare the clinical and radiographic outcomes between feet with or without postoperative sesamoid reduction of proximal metatarsal chevron osteotomy for moderate to severe hallux valgus deformity. METHODS: All of 110 feet were allocated into two groups (reduction group; 66 feet, non-reduction group; 44 feet) according to the reduction status of sesamoid at 6 months after surgery. The clinical and radiographic results of the two groups were compared preoperatively, 6 months follow-up, and at last follow-up. RESULTS: The overall improvement in clinical outcomes was similar in both groups at average 4-year follow-up. However, the radiographic outcomes and recurrence rate were significantly worse in the sesamoid non-reduction group. CONCLUSIONS: Our results suggested that postoperative incomplete reduction of sesamoid may increase a risk for the recurrence of hallux valgus deformity.

Rehabilitation and Return to Sports: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle.

BACKGROUND: The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on Rehabilitation and Return to Sports developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. METHODS: Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed upon in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%. RESULTS: A total of 9 statements on rehabilitation and return to sports reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. All 9 statements reached strong consensus, with at least 86% agreement. CONCLUSIONS: The rehabilitation process for an ankle cartilage injury requires a multidisciplinary and comprehensive approach. This international consensus derived from leaders in the field will assist clinicians with rehabilitation and return to sports after treatment of a cartilage injury of the ankle.

Comparison of Intermediate to Long-Term Outcomes of Total Ankle Arthroplasty in Ankles with Preoperative Varus, Valgus, and Neutral Alignment.

BACKGROUND: Preoperative ankle coronal malalignment has been considered as a risk factor for poor outcomes and failure after total ankle arthroplasty. The present study evaluated whether intermediate to long-term outcomes of total ankle arthroplasty in ankles with preoperative varus and valgus malalignment (5° to 20°) are comparable with those with neutral alignment (<5°). METHODS: We enrolled 144 consecutive ankles that underwent primary total ankle arthroplasty (140 patients) using a mobile-bearing HINTEGRA prosthesis with a minimum follow-up of 4 years; the mean overall follow-up duration was 89 months (51 to 145 months). We divided all patients into 3 groups according to the preoperative coronal plane tibiotalar angle: the varus group (59 ankles, 5° to 20° of varus), the valgus group (34 ankles, 5° to 20° of valgus), and the neutral group (51 ankles, <5°). Patients in each group showed similar characteristics in mean age, sex, body mass index, and follow-up period. RESULTS: The mean 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, and ankle range of motion did not differ meaningfully among the 3 groups at the final follow-up. The final tibiotalar angle showed that the degree of coronal alignment of the varus group was significantly less corrected compared with the neutral group (p = 0.010). The varus group had significantly more concomitant procedures (42 procedures [71.2%]) compared with the neutral group (p = 0.003). The prevalence of major complications did not differ among the 3 groups (p = 0.124). The overall probability of implant survivorship was 91.1% (97.7% in the varus group, 81.1% in the valgus group, and 90.9% in the neutral group) at a mean follow-up of 7.3 years. CONCLUSIONS: In the intermediate to long-term follow-up, mobile-bearing total ankle arthroplasty showed similarly good outcomes in patients with varus and valgus malalignment up to 20° compared with the neutral alignment group when neutrally aligned ankles were achieved postoperatively. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

BCAP promotes osteoclast differentiation through regulation of the p38-dependent CREB signaling pathway.

Many studies have determined that PI3K-Akt signaling pathways play important roles in osteoclast differentiation and function. In the present study, we investigated the roles of B-cell adaptor for PI3K (BCAP), which is a PI3K binding molecule, in osteoclasts. Overexpression of BCAP in osteoclast precursor cells enhanced osteoclast differentiation induced by tumor necrosis factor alpha (TNF-α) as well as receptor activator of nuclear factor-κB ligand (RANKL). Conversely, osteoclast differentiation mediated by both cytokines was attenuated when BCAP expression was downregulated using small interfering RNA. Notably, BCAP induced Akt activation only upon stimulation by RANKL, but not by TNF-α. However, BCAP activated p38-dependent cAMP response element-binding protein (CREB) phosphorylation induced by both RANKL and TNF-α. Collectively, we showed that BCAP plays an important role in osteoclast differentiation by regulating the p38-dependent CREB signaling pathway, and that BCAP might be a new therapeutic target for bone diseases.