Defining the patient acceptable symptom state using PROMIS following reconstruction of the progressive collapsing foot deformity.

BACKGROUND: The patient acceptable symptom state (PASS) represents the threshold beyond which patients are satisfied with their outcome. This study aimed to define PASS thresholds for progressive collapsing foot deformity (PCFD) reconstruction using Patient-Reported Outcomes Measurement Information System (PROMIS) scores and anchor question responses. METHODS: This retrospective study consisted of 109 patients who underwent flexible PCFD reconstruction, had preoperative and 2-year postoperative PROMIS scores, and 2-year postoperative anchor question responses. ROC curve analyses were performed to quantify PASS thresholds. RESULTS: PASS thresholds for the PROMIS Physical Function (PF) and Pain Interference (PI) domains were found to be lower and higher, respectively, than population norms. Furthermore, patients with higher preoperative PROMIS PF scores or lower preoperative PROMIS PI scores had a significantly higher likelihood of achieving the PASS thresholds. CONCLUSION: In addition to guiding future outcomes research, these results may help surgeons optimize treatment for PCFD and better manage patient expectations. LEVEL OF EVIDENCE: III, retrospective cohort study.

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.

Passive Eversion Assessment for Progressive Collapsing Foot Deformity After Lateral Column Lengthening: A Cadaveric Biomechanical Study.

BACKGROUND: Reduced hindfoot eversion motion has been proposed as a cause of increased lateral foot pressure following lateral column lengthening (LCL) for progressive collapsing foot deformity (PCFD). A subjective intraoperative assessment of passive eversion has been suggested to help evaluate correction; however, it is unclear how passive eversion correlates with objective measurements of foot stiffness. Our objectives were to quantify the relationship between the maximum passive eversion in hindfoot joints following LCL with plantar pressure during stance and to determine the influence of wedge size on these outcomes. METHODS: Ten cadaveric specimens extending from the mid-tibia distally were tested on a 6-degrees-of-freedom robot to simulate the stance phase of level walking. Five conditions were tested: intact, simulated PCFD, and 3 LCL wedge conditions (4, 6, and 8 mm). Outcomes included the lateral-to-medial forefoot plantar pressure (LM) ratio during stance and the maximum passive eversion measured in the hindfoot joints. Simple linear regressions were performed to evaluate relationships between outcomes and wedge sizes. RESULTS: A strong negative relationship was found between passive subtalar eversion and the LM ratio during stance (r[38] = -0.46; p = 0.0007), but not between passive talonavicular eversion and the LM ratio (r[38] = -0.02; p = 0.37). Wedge size was strongly related to subtalar eversion (r[38] = -0.77; p < 0.0001), talonavicular eversion (r[38] = -0.55; p = 0.0003), and the LM ratio (r[38] = 0.70; p < 0.0001). Increased wedge size resulted in average decreases in subtalar and talonavicular eversion of 1.0° (95% confidence interval [CI]: 0.8° to 1.3°) and 1.2° (95% CI: 0.6° to 1.6°), respectively. Increased wedge size also increased the LM ratio by 0.38 (95% CI: 0.25 to 0.50), indicating a lateral shift in plantar pressure. CONCLUSIONS: Decreased hindfoot eversion following LCL was related to increased lateral plantar pressure during stance. Increasing wedge size correlated with decreasing passive hindfoot eversion and increasing lateral plantar pressure, suggesting that intraoperative preservation of eversion motion may be important for preventing excessive lateral loading. CLINICAL RELEVANCE: To avoid overcorrection or undercorrection of the deformity, hindfoot eversion assessment in addition to radiographic evaluation may be important for optimizing the amount of lengthening to achieve successful LCL.

Peroneus Brevis to Longus Tendon Transfer in the Treatment of Flexible Progressive Collapsing Foot Deformity: A Cadaveric Study.

BACKGROUND: Although operative treatment of the flexible progressive collapsing foot deformity (PCFD) remains controversial, correction of residual forefoot varus and stabilization of the medial column are important components of reconstruction. A peroneus brevis (PB) to peroneus longus (PL) tendon transfer has been proposed to address these deformities. The aim of our study was to determine the effect of an isolated PB-to-PL transfer on medial column kinematics and plantar pressures in a simulated PCFD (sPCFD) cadaveric model. METHODS: The stance phase of level walking was simulated in 10 midtibia cadaveric specimens using a validated 6-degree of freedom robot. Bone motions and plantar pressure were collected in 3 conditions: intact, sPCFD, and after PB-to-PL transfer. The PB-to-PL transfer was performed by transecting the PB and advancing the proximal stump 1 cm into the PL. Outcome measures included the change in joint rotation of the talonavicular, first naviculocuneiform, and first tarsometatarsal joints between conditions. Plantar pressure outcome measures included the maximum force, peak pressure under the first metatarsal, and the lateral-to-medial forefoot average pressure ratio. RESULTS: Compared to the sPCFD condition, the PB-to-PL transfer resulted in significant increases in talonavicular plantarflexion and adduction of 68% and 72%, respectively, during simulated late stance phase. Talonavicular eversion also decreased in simulated late stance by 53%. Relative to the sPCFD condition, the PB-to-PL transfer also resulted in a 17% increase (P = .045) in maximum force and a 45-kPa increase (P = .038) in peak pressure under the first metatarsal, along with a medial shift in forefoot pressure. CONCLUSION: The results from this cadaver-based simulation suggest that the addition of a PB-to-PL transfer as part of the surgical management of the flexible PCFD may aid in correction of deformity and increase the plantarflexion force under the first metatarsal. CLINICAL RELEVANCE: This study provides biomechanical evidence to support the addition of a PB-to-PL tendon transfer in the surgical treatment of flexible PCFD.

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.

Radiographic Analysis of Valgus Ankle Deformity With or Without Medial Longitudinal Arch Collapse.

BACKGROUND: Establishing a surgical plan for ankle deformities necessitates a comprehensive understanding of the deforming forces involved, and the morphology of the ankle deformity plays an important role as well. Valgus tibiotalar tilt development has mostly been described in patients with a low medial longitudinal arch, as seen in progressive collapsing foot deformity (PCFD). However, some valgus ankles demonstrate no radiographic evidence of a collapsed medial arch. This study aims to investigate whether there are differences in the radiographic morphology of valgus ankle deformities between patients with and without a low medial longitudinal arch to explore if they have different etiologies. METHODS: We retrospectively reviewed patients who underwent surgical treatment for asymmetric valgus ankle deformity at our institution between 2017 and 2021. Patients with a valgus tibiotalar tilt (TT) greater than 4 degrees and Meary angle greater than 30 degrees (mean: 38.9) were included in the PCFD group (n = 29). The non-PCFD group (n = 24) with TT greater than 4 degrees and Meary angle less than 4 degrees (mean: 0.3) was also established. In the weightbearing ankle anteroposterior view, the TT and medial distal tibial angle were measured. Additionally, to assess the mediolateral position of the talus, the talar center migration (TCM) and lateral talar dome-plafond distance (LTD-P) ratio in the coronal plane were measured. In weightbearing computed tomography (WBCT), the degree of axial plane talocalcaneal subluxation and the prevalence of sinus tarsi bony impingement were assessed. Intergroup comparison was conducted. RESULTS: Both groups demonstrated a similar degree of TT, with a mean of 11.6 degrees in the PCFD group and 13.7 degrees in the non-PCFD group (P = .2330). However, the PCFD group showed a significantly greater TCM and LTD-P ratio compared with those of the non-PCFD group (P < .0001), indicating that PCFD patients have a more medially translated talus in ankle anteroposterior radiographs. WBCT showed that the PCFD group on average had 18 degrees greater axial plane talocalcaneal subluxation (P < .0001) and 52% higher prevalence of sinus tarsi bony impingement (P = .0002) compared with the non-PCFD group. CONCLUSION: This study suggests that valgus ankles may exhibit different radiographic morphologies depending on the status of the longitudinal arch. Valgus ankles in PCFD patients tend to have a more medially translated talus. This finding may suggest the presence of different deforming forces between the 2 groups and may indicate the need for different treatment strategies to address talar tilt. LEVEL OF EVIDENCE: Level III, case-control.

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.

AAV2 vector optimization for retinal ganglion cell-targeted delivery of therapeutic genes.

Recombinant adeno-associated virus (AAV)-2 has significant potential as a delivery vehicle of therapeutic genes to retinal ganglion cells (RGCs), which are key interventional targets in optic neuropathies. Here we show that when injected intravitreally, AAV2 engineered with a reporter gene driven by cytomegalovirus (CMV) enhancer and chicken ß-actin (CBA) promoters, displays ubiquitous and high RGC expression, similar to its synthetic derivative AAV8BP2. A novel AAV2 vector combining the promoter of the human RGC-selective γ-synuclein (hSNCG) gene and woodchuck hepatitis post-transcriptional regulatory element (WPRE) inserted upstream and downstream of a reporter gene, respectively, induces widespread transduction and strong transgene expression in RGCs. High transduction efficiency and selectivity to RGCs is further achieved by incorporating in the vector backbone a leading CMV enhancer and an SV40 intron at the 5' and 3' ends, respectively, of the reporter gene. As a delivery vehicle of hSIRT1, a 2.2-kb therapeutic gene with anti-apoptotic, anti-inflammatory and anti-oxidative stress properties, this recombinant vector displayed improved transduction efficiency, a strong, widespread and selective RGC expression of hSIRT1, and increased RGC survival following optic nerve crush. Thus, AAV2 vector carrying hSNCG promoter with additional regulatory sequences may offer strong potential for enhanced effects of candidate gene therapies targeting RGCs.

Does the Presence of Asymptomatic Flatfoot Deformity Impact the Clinical and Radiographic Outcomes of the Minimally Invasive Chevron and Akin Bunionectomy?

BACKGROUND: Flatfoot deformity is believed to play a role in hallux valgus development and recurrence. While symptomatic flatfoot deformity can be treated with separate procedures at the time of hallux valgus correction, the question remains whether the patient undergoing correction of a symptomatic hallux valgus deformity should have their asymptomatic flatfoot concurrently addressed. We aimed to investigate whether the presence of asymptomatic flatfoot influences patient-reported and radiographic outcomes of the minimally invasive chevron and Akin bunionectomy. METHODS: A total of 104 patients were included in this study. Forty-two asymptomatic patients met the radiographic criteria for flatfoot while 62 had a normal arch. Patient-reported outcomes were evaluated and compared between the two groups using validated PROMIS measures preoperatively and at a minimum one-year postoperatively. Radiographic outcomes including hallux valgus angle (HVA), intermetatarsal angle (IMA), Meary's angle, calcaneal pitch (CP), and talonavicular coverage angle (TNCA) were measured and compared preoperatively and minimum six-months postoperatively. RESULTS: Both groups demonstrated similar preoperative and postoperative PROMIS scores with significant improvements in physical function, pain interference, pain intensity, and global physical health. Preoperatively, HVA was similar between both groups, however the flatfoot group showed a greater IMA, Meary's angle, TNCA, and lower CP. Postoperatively, HVA and IMA were similar between groups, although patients in the flatfoot group retained a significantly greater Meary's angle, TNCA, and lower CP. Both groups showed significant improvements in HVA, IMA, and TNCA. CONCLUSION: Our study indicates that the minimally invasive chevron and Akin bunionectomy leads to improved clinical and radiographic hallux valgus outcomes without adversely impacting radiographic flatfoot parameters. Therefore, the MIS bunionectomy may be an effective option for hallux valgus correction in patients with mild, asymptomatic flatfoot. LEVEL OF EVIDENCE: Level III, retrospective cohort.

A Patient-Reported Outcome-Based Comparison of Cheilectomy With and Without Proximal Phalangeal Dorsiflexion Osteotomy for Hallux Rigidus.

INTRODUCTION: This study provides the first comparison of patient-reported outcomes between isolated cheilectomy (C) and cheilectomy with Moberg (CM) osteotomy for hallux rigidus. METHODS: A single-center, retrospective registry search identified all patients with preoperative Patient-Reported Outcomes Measurement Information System (PROMIS) scores who underwent cheilectomy, with and without concomitant proximal phalangeal dorsiflexion osteotomy, for hallux rigidus between January 2016 and December 2020. Because there were far fewer isolated cheilectomies (62), all C patients were compared with a commensurate number of consecutive CM cases (67) using preoperative, 1-year, and 2-year PROMIS scores for physical function, pain interference, pain intensity, global physical health, global mental health, and depression, as well as complication and revision data from a chart review. A multivariable linear regression analysis was performed to compare adjusted postoperative PROMIS scores between the 2 cohorts. RESULTS: There were no differences between groups among the demographic and preoperative variables compared. The CM cohort reported worse pain interference scores preoperatively (P < .001) and at 1 year postoperatively (P = .01). However, the C cohort reported worse pain intensity scores preoperatively (P < .001) and at 1 year postoperatively (P < .001). Adjusted postoperative PROMIS score comparison demonstrated that the CM cohort had better 1-year postoperative pain intensity scores (P < .05). However, there were no differences between cohorts for additional PROMIS scores or complications data. CONCLUSION: The addition of a Moberg osteotomy does not appear to significantly change short- to medium-term outcomes of cheilectomy for hallux rigidus treatment. LEVELS OF EVIDENCE: Level III: Retrospective comparative 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.

Phase I Safety and Feasibility Pilot of Hepatic Artery Infusion Chemotherapy in a Rural Catchment Area Using The Codman Vascular Catheter with The Medtronic SynchroMed II Pump for Intrahepatic Cancers.

BACKGROUND: Discontinuation of the Codman 3000 pump in 2018 left no Food and Drug Administration (FDA)-approved hepatic artery infusion (HAI) device for unresectable colorectal liver metastases (uCLM) and intrahepatic cholangiocarcinoma (uIHC). Historically, HAI has been performed at academic medical centers in large metropolitan areas, which are often inaccessible to rural patients. Consequently, feasibility of dissemination of HAI to rural populations is unknown. PATIENTS AND METHODS: Under an FDA investigational device exemption, we opened the only HAI program in Kentucky and enrolled patients with uCLM and uIHC in a phase I clinical trial. The trial examined the safety of the hybrid Codman catheter/Medtronic SynchroMed II pump (hCMP) combination, defined as successful completion of one cycle of HAI chemotherapy. Rural feasibility was assessed by number of missed pump fills appointments. RESULTS: A total of 21 patients (n = 17 uCLM, n = 4 uIHC) underwent hCMP implantation before accrual was stopped early owing to FDA approval of the Intera 3000 pump. 20/21 (95%) patients met the primary safety endpoint. Serious adverse events (AEs) included a grade 5 coronavirus disease 2019 (COVID-19) infection (n = 1) and a grade 3 catheter erosion into the bowel (n = 1). Biliary sclerosis developed in two patients (9.5%). Median distance to infusion center was 47.6 miles (2-138 miles), and 62% were from Appalachia, yet there were no missed pump fill appointments. The 2-year overall survival was 82.4% (uCLM) and 50% (uIHC). CONCLUSIONS: The hCMP device had an acceptable safety profile. Despite the complexity of starting a new HAI program, early results showed feasibility for HAI delivery in a rural catchment area and comparable outcomes to larger urban-based HAI centers.

Early Survivorship, Clinical and Radiographic Outcomes of a Modular Augmented Revision Total Ankle Arthroplasty System.

BACKGROUND: As the number of total ankle arthroplasties (TAAs) performed annually increases, there is increased demand for modular revision implants. There is limited early survivorship and clinical outcome data for the INVISION Total Ankle Arthroplasty System (Wright Medical Technology/Stryker). This study aims to determine early implant survivorship, complications, and radiographic and patient-reported outcomes (PROs) of the INVISION implant in the revision setting. METHODS: This is a single-institution retrospective review of adult patients who underwent revision TAA with the INVISION implant with minimum 2-year follow-up. Demographics, complications, radiographic data, and PROs (PROMIS) were collected. The primary outcome was implant survivorship. Secondary outcomes were reoperation, radiographic complications, and PROs. RESULTS: Nineteen patients underwent revision INVISION TAA with mean follow-up of 3.5 years. INVISION revision TAA was used for tibial (n = 6) or talar (n = 7) component subsidence, recurrent tibiotalar malalignment (valgus = 1, varus = 3), and postinfection bone loss (n = 2). Two-year implant survivorship was 100%. There were no reoperations. One patient had lucency of the talar component at 6 months post TAA revision with INVISION. One patient had talar subsidence at final follow-up. Two-year postoperative follow-up PROMIS domains improved significantly (P < .05). CONCLUSION: There was excellent short-term survivorship of the INVISION TAA implant, with no failures. There were significant improvements in PROs and low rates of subsidence and lucencies. The results of this study support using the INVISION implant in the revision TAA setting. LEVEL OF EVIDENCE: Level III, retrospective cohort.

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.