Postoperative Medial Malleolar Fractures in Total Ankle Replacement Are Associated With Decreased Medial Malleolar Width and Varus Malalignment: A Case-Control Study.

BACKGROUND: There are limited data regarding risk factors associated with periprosthetic medial malleolar fractures in total ankle arthroplasty (TAA). This case-control study aimed to identify the risk factors and analyze the effect of prophylactic screw fixation in preventing a medial malleolar fracture after TAA. METHODS: A case-control study was conducted on 149 patients who underwent primary TAA. Twenty patients with postoperative medial malleolar fractures >4 weeks postoperatively (cases) were identified. An additional 129 patients (controls) were randomly selected from the TAA database. Radiographic evaluation included tibial component coronal alignment and postoperative medial malleolar width. Demographics and radiographic variables were compared between cohorts. Logistic regression was used to investigate the association between medial malleolar fracture and postoperative coronal alignment, medial malleolar width, and prophylactic fixation of the medial malleolus. RESULTS: Mean (SD) medial malleolar width was significantly smaller in the fracture cohort (8.52 mm [1.6]) than in the control group (11.78 mm [1.74]) (P < .001). Mean (SD) tibial component coronal alignment was 92.17 degrees (2.77) in the fracture cohort and 90.21 degrees (1.66) in the control group (P = .002). Regression analysis identified a significant negative association between postoperative medial malleolar width and the probability of fracture (OR = 0.06, 95% CI 0.01, 0.26, P < .001). Varus malalignment of the tibial component was positively associated with the probability of fracture (OR = 1.90, 95% CI 1.27, 2.86, P = .002). Prophylactic screw fixation resulted in more than 90% reduction in the odds of a fracture (OR = 0.04, 95% CI 0.01, 0.45, P = .01). ROC curve analysis determined a medial malleolar width of 10.3 mm as a potential threshold for predicting fracture. CONCLUSION: Decreased medial malleolar width and postoperative varus malalignment were associated with an increased risk of postoperative medial malleolar fracture. Therefore, surgeons should consider prophylactic screw fixation in patients with a medial malleolar width <10.3 mm or at risk of postoperative varus deformity.

Twelve-Year Progression of Osteochondral Lesions of the Talus Observed Using Magnetic Resonance Imaging.

Osteochondral lesions of the talus are common injuries that are most often the result of trauma. The natural progression of osteochondral lesions is not well understood. It is still unclear which lesions eventually lead to joint degeneration and osteoarthritic changes and if the treatment method affects the progression. The existing literature surrounding this topic is sparse, with inconsistent findings. The presented images are taken from a 72-year-old man with bilateral osteochondral lesions of the talus. To our knowledge, this is the first published series of images illustrating the natural progression of a patient with bilateral osteochondral lesions of the talus over a 12-year time period.

Defining the Patient Acceptable Symptom State (PASS) for PROMIS After Total Ankle Replacement.

BACKGROUND: Although patient-reported outcomes (PROs), such as the Patient-Reported Outcomes Measurement Information System (PROMIS), are a key element of evaluating success after total ankle replacement (TAR), many do not explicitly state a key factor of postoperative success: is the patient satisfied with their outcome after TAR? The patient acceptable symptom state (PASS) represents the symptom threshold beyond which patients consider themselves well. This study aimed to establish the PROMIS thresholds for the PASS in a primary cohort of TAR patients. METHODS: This single-institution study included 127 primary TAR patients with preoperative and 2-year postoperative PROMIS scores. At 2 years postoperatively, patients answered 2 PASS anchor questions (Satisfaction, Delighted-Terrible scale) with Likert-scale responses. PASS thresholds with 95% confidence intervals (CIs) were calculated from PROMIS scores using an anchor-based method. Using a bootstrapping technique with 1,000 iterations, the Youden index was calculated to determine the best specificity and sensitivity coordinates to maximize their combination. Finally, preoperative variables associated with the likelihood of achieving the PASS were assessed. RESULTS: There was a strong association between PASS thresholds and PROMIS domains, especially Pain Interference (PASS threshold of <56.0, area under the receiver operating characteristic curve [AUC] = 0.940), Pain Intensity (<48.4, AUC = 0.936), and Physical Function (>44.7, AUC = 0.883). The likelihood of achieving the PASS was not affected by age, race, gender, American Society of Anesthesiologists (ASA) class, body mass index, or severity of ankle deformity. Patients with worse preoperative Physical Function and Global Mental Health scores were less likely to meet the PASS threshold for Physical Function postoperatively (p = 0.028 and 0.041). CONCLUSIONS: The ability to reach the PASS after TAR was most strongly associated with postoperative PROMIS pain scores. However, PASS thresholds were generally poorer than population means. This demonstrates that patients do not need to reach normal pain or physical function levels to have an acceptable symptom state after TAR. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fabrication of a Novel 3D Extrusion Bioink Containing Processed Human Articular Cartilage Matrix for Cartilage Tissue Engineering.

Cartilage damage presents a significant clinical challenge due to its intrinsic avascular nature which limits self-repair. Addressing this, our study focuses on an alginate-based bioink, integrating human articular cartilage, for cartilage tissue engineering. This novel bioink was formulated by encapsulating C20A4 human articular chondrocytes in sodium alginate, polyvinyl alcohol, gum arabic, and cartilage extracellular matrix powder sourced from allograft femoral condyle shavings. Using a 3D bioprinter, constructs were biofabricated and cross-linked, followed by culture in standard medium. Evaluations were conducted on cellular viability and gene expression at various stages. Results indicated that the printed constructs maintained a porous structure conducive to cell growth. Cellular viability was 87% post printing, which decreased to 76% after seven days, and significantly recovered to 86% by day 14. There was also a notable upregulation of chondrogenic genes, COL2A1 (p = 0.008) and SOX9 (p = 0.021), suggesting an enhancement in cartilage formation. This study concludes that the innovative bioink shows promise for cartilage regeneration, demonstrating substantial viability and gene expression conducive to repair and suggesting its potential for future therapeutic applications in cartilage repair.

Safety of Same-Day Discharge Following Total Ankle Arthroplasty: A Retrospective Cohort Analysis.

Background: Joint replacement procedures have traditionally been performed in an inpatient setting to minimize complication rates. There is growing evidence that total ankle arthroplasty (TAA) can safely be performed as an outpatient procedure, with the potential benefits of decreased health care expenses and improved patient satisfaction. Prior studies have not reliably made a distinction between outpatient TAA defined as length of stay <1 day and same-day discharge. The purpose of our study was to compare a large volume of same-day discharge and inpatient TAA for safety and efficacy. Methods: Patients undergoing TAA at our US-based institution are part of an institutional review board-approved registry. We queried the registry for TAA performed by the single highest-volume surgeon at our institution between May 2020 and March 2022. Same-day discharge TAA was defined as discharge on the day of the procedure. Patient demographics, baseline clinical variables, concomitant procedures, postoperative complications, and patient-reported outcomes were collected. Postoperative outcomes were compared after 1:1 nearest-neighbor matching by age, sex, Charlson Comorbidity Index (CCI), and American Society of Anesthesiologists (ASA) score. Multivariable models were created for comparison with the matched cohort outcome comparison analysis. Results: Our same-day discharge group was younger (median 58 vs 67 years; P < .001), with proportionally fewer females (36.4% vs 51.4%; P = .044) and lower Charlson Comorbidity Indices (median 1 vs 3; P < .001) than the inpatient group. At a median follow-up of 1 year, after matching by age, sex, CCI, and ASA score, there was no difference in complications (P = .788), reoperations (P = .999), revisions (P = .118), or Patient-Reported Outcomes Measurement Information System (PROMIS) scores between the 2 groups. Multivariable analyses performed demonstrated no evidence of association between undergoing same-day discharge TAA vs inpatient TAA and reoperation, revision, complication, or 1-year PROMIS scores (P > .05). Conclusion: In our system of health care, with appropriate patient selection, same-day discharge following TAA can be a safe alternative to inpatient TAA. Level of Evidence: Level III, retrospective cohort study.

Discrepancies Between Intraoperative and Postoperative Ankle Motion Measured for Anterior-Approach Total Ankle Arthroplasty.

BACKGROUND: Although intraoperative ankle motion serves as a foundational reference for anticipated motion after surgery and guides the addition of procedures to enhance ankle motion in total ankle arthroplasty (TAA), the relationship between intraoperative and postoperative ankle motion remains unclear. This study aimed to investigate the discrepancy between intraoperative and postoperative ankle range of motion (ROM) following TAAs using the anterior-approach, fixed-bearing systems. METHODS: This study retrospectively reviewed 67 patients (67 ankles) who underwent primary TAA at a single institution. Three different types of anterior-approach, fixed-bearing TAA systems were included. Intraoperative fluoroscopy was used to document the maximal dorsiflexion and plantar flexion at the end of the case. Standardized weightbearing maximum dorsiflexion and plantar flexion sagittal radiographs were obtained pre- and postoperatively, following a previously described method. The motion between 3 different time points (preoperative, intraoperative, and postoperative [mean 11.4 months]) was compared using pairwise t tests, and their differences were quantified. RESULTS: The mean total tibiotalar ROM was 38.1 degrees (SD 7.8) intraoperatively, and the postoperative total tibiotalar ROM was 24.2 degrees (SD 9.7) (P < .001), indicating that a mean of 65.3% (SD 26.7) of the intraoperative motion was maintained postoperatively. Intraoperative dorsiflexion (mean 11.6 [SD 4.5] degrees) showed no evidence of difference from postoperative dorsiflexion (mean 11.4 [SD 5.8] degrees, P > .99), indicating that a median of 95.6% (interquartile range: 66.2-112) of the intraoperative maximum dorsiflexion was maintained postoperatively. However, there was a significant difference between intraoperative plantarflexion (mean 26.4 [SD 6.3]) and postoperative plantarflexion (12.8 [SD 6.9] degrees, P < .001), indicating a mean 50.6% (SD 29.6) of intraoperative motion maintained in the postoperative assessment. There was an improvement of 2.5 degrees in the total tibiotalar ROM following TAA with statistical significance (P < .043). CONCLUSION: This study revealed a significant difference between intraoperative ankle ROM and ankle ROM approximately 1 year after anterior-approach, fixed-bearing TAA, mainly due to plantarflexion motion restriction. Minimal difference in dorsiflexion suggests the importance of achieving the desired postoperative dorsiflexion motion during the surgery using the best possible adjunct procedures. LEVEL OF EVIDENCE: Level IV, case series.

Implant Choice May Reduce the Risk of Early Mechanical Failure in Total Ankle Replacement.

BACKGROUND: Total ankle replacements (TARs) have rapidly advanced in terms of volume, technique, design, and indications. However, TARs are still at risk for early mechanical failure and revision. Prior studies have investigated potential risk factors for failure, but have been limited to smaller series or older implants. This study sought to identify risk factors for early mechanical failure in modern TAR. METHODS: This is a retrospective study of a single-institution registry. Five surgeons contributed cases involving patients who underwent a primary TAR with any implant. Implants were grouped on the basis of the type of fixation. The primary outcome was early mechanical failure (revision with component removal for a non-infectious etiology, that is, subsidence, aseptic loosening, and/or malalignment). Logistic regression determined the effects of age, weight, hindfoot arthrodesis, implant type, and radiographic deformity on failure. RESULTS: The 731 included patients had a mean follow-up of 2.7 years. Ten percent (71 patients) had hindfoot arthrodesis. There were 33 mechanical failures (4.5%) at a mean of 1.7 years after the index surgical procedure. Our model demonstrated that hindfoot arthrodesis was associated with 2.7 times greater odds of failure (p = 0.045), every 10 kg of body weight increased the odds of tibial-sided failure by 1.29 times (p = 0.039), and implants with more extensive tibial fixation (stems or keels) lowered the odds of tibial failure by 95% (p = 0.031). CONCLUSIONS: In patients with uncontrollable risk factors (hindfoot arthrodesis) or risk factors that may or may not be modifiable by the patient (weight), implants with more robust tibial fixation may be able to reduce the risk of early mechanical failure. Further research is warranted to support efforts to decrease early failure in TAR. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Effects of Travel Distance on Complications and Outcomes in Total Ankle Arthroplasty.

Owing to the last decade's increase in the number of total ankle arthroplasty (TAA) procedures performed annually, there is a concern that the disproportionate distribution of orthopaedic surgeons who regularly perform TAA may impact complications and/or patient satisfaction. This study examines patient-reported outcomes and complications in TAA patients who had to travel for surgery compared to those treated locally. This is a single-center retrospective review of 160 patients undergoing primary TAA between January 2016 and December 2018, with mean age 65 (range: 59-71) years, mean body mass index (BMI) 28.7 kg/m2, 69 (43.1%) females, and mean 1.5 (SD = 0.51) years follow-up. Patients were grouped by distance traveled (<50 miles [n = 89] versus >50 miles traveled [n = 71]). There were no significant differences in rate or type of postoperative complications between the <50 mile group (16.9%) and the >50 mile group (22.5%) (P = .277). Similarly, there were no significant difference in postoperative PROMIS scores between the groups (P = .858). Given uneven distribution of high-volume surgeons performing TAA, this is important for patients who are deciding where to have their TAA surgery and for surgeons on how to counsel patients regarding risks when traveling longer distances for TAA care.Levels of Evidence: Level III: Retrospective Cohort Study.

Influence of Joint Line Level on Clinical Outcomes and Range of Motion in Total Ankle Arthroplasty.

BACKGROUND: Ankle arthritis leads to an elevated joint line compared to the nonarthritic ankle, as measured by the "joint line height ratio" (JLHR). Previous work has shown that the JLHR may remain elevated after total ankle arthroplasty (TAA). However, the clinical impact of this has yet to be determined. This study assessed the correlation between postoperative JLHR, post-TAA range of motion (ROM), and 1-year Patient-Reported Outcome Measurement Information System (PROMIS) scores. METHODS: A retrospective review of 150 patients who underwent primary TAA was performed. Preoperative and postoperative JLHR, as well as postoperative dorsiflexion, plantarflexion, and total ROM, was calculated on weightbearing radiographs at a minimum of 1-year follow-up. Correlation between JLHR, post-TAA ROM, and 1-year PROMIS scores was investigated using Pearson correlation and multiple linear regression models. Interobserver reliability for the JLHR was also calculated. RESULTS: Interobserver reliability for the JLHR was excellent (r = 0.98). Mean (SD) JLHR changed from 1.66 (0.45) to 1.55 (0.26) after TAA (P < .001), indicating that the joint line was lowered after TAA. An elevated joint line was correlated with decreased post-TAA dorsiflexion (r = -0.26, P < .001), total ROM (r = -0.18, P = .025), and worse 1-year PROMIS physical function (r = -0.22, P = .046), pain intensity (r = 0.22, P = .042), and pain interference (r = 0.29, P = .007). There was no correlation between the JLHR and post-TAA plantarflexion (r = -0.025, P = .76). Regression analysis identified a 0.5-degree reduction in post-TAA dorsiflexion with each 0.1-unit increase in JLHR (Coeff. = -5.13, P = .005). CONCLUSION: In this patient cohort, we found that an elevated joint line modestly correlated with decreased postoperative dorsiflexion, total ROM, and worse 1-year PROMIS scores. These data suggest that effort likely should be made toward restoring the native joint line at the time of TAA. In addition, future studies investigating the clinical outcomes after TAA may consider including a measure of joint line height, such as the JLHR, because we found it was associated with patient-reported outcomes. LEVEL OF EVIDENCE: Level III, retrospective review of prospectively collected data.

Midterm Clinical Outcomes, Radiographic Outcomes, and Survivorship of the Infinity Total Ankle Arthroplasty.

BACKGROUND: The Infinity Total Ankle Arthroplasty (Stryker, Mahwah, NJ) is a low-profile fixed-bearing implant first introduced in 2014. Although the short-term survivorship (2-4 years follow-up) and complication rates of the Infinity TAA have been reported, there are limited midterm outcome reports. The aim of this study was to describe the survivorship and clinical outcomes of a single-center experience with the Infinity implant at minimum 5-year follow-up. METHODS: Retrospective review of 65 ankles that underwent primary total ankle arthroplasty (TAA) with the Infinity implant was conducted. Mean clinical follow-up was 6.5 years (range, 5.0-8.0). Preoperative and postoperative radiographs were measured to assess tibiotalar alignment, periprosthetic lucencies, and cysts. Preoperative, 2-year, and 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscores were compared to assess midterm clinical outcomes. Survivorship assessment was determined by removal of 1 or both metallic implant components. RESULTS: Survivorship of the implant was 93.8% at final follow-up. There were 4 revisions: 2 for tibial implant loosening, 1 for talar loosening, and 1 for loosening of both components. Three of the 4 revisions occurred within the first 2 years following implantation, and the last failure occurred at 7 years postoperatively. There were 11 reoperations in 10 (15%) ankles and 3 wound complications. There were 17 ankles (26.2%) with radiographic abnormalities around the implants, including 14 cases with tibial component lucencies and 4 cases of periimplant cysts. FAOS outcome measurement showed general stability between 2 and 5 years and substantial improvement from preoperative status. CONCLUSION: To date this study is the largest midterm report on the Infinity total ankle prosthesis, with 65 implants at a mean follow-up of 6.5 years. We found good midterm implant survivorship, and patients experienced significant improvements in FAOS outcome scores and radiographic alignment at final follow-up. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Evaluating Failure Mechanisms for Total Talus Replacement: Contemporary Review.

BACKGROUND: As total talus replacement (TTR) grows in popularity as a salvage option for talar collapse, a critical evaluation of the complications associated with this procedure is indicated. METHODS: In this review of the literature, we present a patient report and provide a review of several complications seen after TTR, including ligamentous instability, infection, and adjacent joint osteoarthritis, which we have encountered in our practice. RESULTS: Total talus replacement has the potential to reduce pain and preserve range of motion. However, the treating surgeon must be cognizant of the variety of adverse outcomes. We have presented cases of potential devastating complications from our own clinical experience and the literature. CONCLUSIONS: In conclusion, TTR may have utility in the properly selected patient with end-stage talar collapse, but implant composition, indications, and patient demographic variables complicate the interpretation of the literature.Levels of Evidence: Level III.

Early outcomes of the Exactech Vantage fixed-bearing total ankle replacement.

Aims: The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant. Methods: This is a single-centre retrospective review of patients who underwent primary total ankle arthroplasty (TAA) with a Vantage implant between November 2017 and February 2020, with a minimum of two years' follow-up. Four surgeons contributed patients. The primary outcome was reoperation and revision rate of the Vantage implant at two years. Secondary outcomes included radiological alignment, peri-implant complications, and pre- and postoperative patient-reported outcomes. Results: There were 168 patients (171 ankles) included with a mean follow-up of 2.81 years (2 to 4.6) and mean age of 63.0 years (SD 9.4). Of the ten ankles with implant failure (5.8%), six had loosening of the tibial component. In the remaining four failed implants, one was due to periprosthetic joint infection (PJI), one was due to loosening of the talar component, and two were due to loosening of both the tibial and talar components. Seven patients underwent reoperation: irrigation and debridement for superficial infection (n = 4); bone grafting for cysts (n = 2); and open reduction internal fixation (n = 1). Asymptomatic peri-implant lucency/subsidence occurred in 20.1% of ankles, with the majority involving the tibial component (n = 25). There were statistically significant improvements in PROMs in all domains. Conclusion: Short-term results of this implant demonstrate early survival comparable to the reported survivorship of similar low-profile, non-stemmed implants. Radiological lucency occurred more commonly at the tibial component, and revisions occurred primarily due to loosening of the tibial component. Further research is needed to evaluate longer-term survivorship.

Outcomes of Total Ankle Arthroplasty in Postfracture Ankle Arthritis.

BACKGROUND: Ankle arthritis that develops after fracture accounts for a significant portion of ankle arthritis necessitating total ankle arthroplasty (TAA). It remains unknown whether TAA in postfracture patients produces equivalent outcomes to those without fracture history. The purpose of this study was to evaluate the medium-term outcomes of TAA in postfracture ankle arthritis compared to those without fracture history. METHODS: This study reviewed 178 ankles from 171 consecutive patients who underwent TAA in our institution between 2007 and 2017 and completed a minimum 5-year follow-up. Four different TAA systems were utilized by 6 surgeons. Based on fracture history, patients were divided into 2 groups: the postfracture group (n = 63; median age 65.7 years; median follow-up 5.9 years) and the nonfracture group (n = 115; median age 64.4 years; median follow-up 6.2 years). Types and rates of complications including revision and reoperation were compared. Minimum 5-year Foot and Ankle Outcome Score (FAOS) and postoperative improvement were investigated. A subgroup analysis was performed to determine whether outcomes differ between intraarticular fracture patients (n = 43) and extraarticular fracture patients (n = 20). RESULTS: Both groups exhibited comparable postoperative improvement and final FAOS scores. The postfracture group had a significantly higher reoperation rate than the nonfracture group (20 of 63, 31.7%, vs 17 of 115, 14.8%; P = .011), with gutter impingement being the most common cause. There were 3 revisions in each group. In the subgroup analysis, we found no evidence of statistical difference between the intraarticular fracture group and the extraarticular fracture group in terms of FAOS scores, revision, and reoperation rates. CONCLUSION: In this single-center, retrospective comparative study, we found total ankle arthroplasty in patients with a history of fractures around the ankle joint had no evidence of statistical difference in patient-reported outcomes and implant survivorship but led to a higher rate of nonrevision reoperation following surgery. In the much smaller subset of patients with previous fracture, we did not find that those with a history of intraarticular fracture had inferior outcomes after TAA when compared to those with a history of extraarticular fracture. LEVEL OF EVIDENCE: Level III, case-control study.