Incidence and predictors of valgus tibiotalar tilt after progressive collapsing foot deformity reconstruction using subtalar fusion with concomitant procedures.

PURPOSE: Development of valgus tibiotalar tilt is a significant complication after subtalar fusion for progressive collapsing foot deformity (PCFD) correction. However, its incidence and etiologic factors have not been extensively studied. The purpose of this study was to define the incidence of valgus tibiotalar tilt after subtalar fusion for PCFD reconstruction, and to determine predictors of this complication. METHODS: This study included 59 patients who underwent PCFD reconstruction with subtalar fusion. Patients with tibiotalar tilt prior to surgery were excluded. On standard weightbearing radiographs, the talonavicular coverage angle, talo-1st metatarsal angle, calcaneal pitch, hindfoot moment arm (HMA), and medial distal tibial angle were measured. Weightbearing computed tomography (WBCT) was used to determine the presence of lateral bony impingement. A radiologist evaluated the superficial and deep deltoid ligaments using magnetic resonance imaging (MRI). Univariate regression analysis was used to identify the factors associated with development of postoperative valgus tibiotalar tilt, defined as tilt > 2 degrees. RESULTS: Seventeen patients (28.8%) developed postoperative valgus tibiotalar tilt at a mean of 7.7 (range 2-31) months. Eight (47.1%) of these patients developed valgus tibiotalar tilt within 3 months. Univariate logistic regression demonstrated association between preoperative HMA and postoperative valgus tibiotalar tilt (odds ratio 1.06, P = 0.026), with a 6% increase in risk per millimeter of increased HMA. Deltoid ligament status and concomitant procedures on other joints did not correlate with postoperative valgus tilt. CONCLUSION: Our findings indicate that surgeons should be cognizant of patients with a greater degree of preoperative hindfoot valgus and their propensity to develop a valgus ankle deformity. Additionally, our relatively high incidence of valgus tibiotalar tilt suggests that weightbearing ankle radiographs should be included in the initial and subsequent follow-up of PCFD patients with hindfoot valgus treated with subtalar fusion.

Mid-term functional outcomes following reoperation after total ankle arthroplasty: A retrospective cohort study.

BACKGROUND: Despite a significant reported rate of non-revision reoperation after total ankle arthroplasty (TAA), it is uncertain if these subsequent procedures have an impact on the longer term outcomes. This study aimed to compare minimum five-year functional outcomes of patients who had undergone reoperation after TAA to those who did not require reoperation. METHODS: Seventy-six ankles (74 patients) who underwent TAA with the Salto Talaris fixed bearing system between 2007 and 2014 were allocated into two groups based on presence (n = 16) or absence of reoperation (n = 60). Reoperations included all secondary procedures after index TAA, excluding revision surgeries requiring removal or exchange of the original prosthesis. The foot and ankle outcome score (FAOS) at preoperative and minimum five-year follow-up was compared between the groups. Additionally, improvements in FAOS subscales were compared. Preoperative deformity, postoperative implant alignment, number of periprosthetic cysts, and subsidence between groups were compared using standard weightbearing radiographs. RESULTS: The most common cause of reoperation was gutter impingement (n = 11), followed by stress fracture of the medial malleolus (n = 2), tarsal tunnel syndrome (n = 1), periprosthetic cyst (n = 1), and infection (n = 1). In comparison to the non-reoperation group, all FAOS subscales except for the Sports and Recreational Activities subscale were significantly lower in the reoperation group at final follow-up. The reoperation group exhibited significantly less improvement in the Pain, Symptoms, and Quality of Life subscales at final follow-up (p < 0.05). There were no statistical differences in the radiographic parameters between both groups. CONCLUSIONS: Patients who underwent reoperation after TAA demonstrated inferior functional outcomes at mid-term follow-up. An emphasis should be placed on preventing possible causes of reoperations to achieve favorable patient outcomes. Additionally, if a reoperation is deemed necessary, a thorough evaluation and surgical correction of underlying causes should be achieved.

The use of three-dimensional biometric Foot and Ankle Offset to predict additional realignment procedures in total ankle replacement.

BACKGROUND: Decision to perform associated corrective alignment procedures in patients undergoing total ankle replacement (TAR) is commonly made intraoperatively. The Foot and Ankle Offset (FAO) can evaluate multiplanar deformity and be an effective instrument in surgical planning. This study objective was to assess the ability of this tool to predict the need for additional realignment procedures at the time of TAR. METHODS: In this retrospective study, we enrolled 21 patients who underwent TAR and had preoperative WBCT studies. Two independent and blinded observers calculated the preoperative FAO using dedicated software. FAO measurements were compared between the different alignment groups (physiological alignment, valgus and varus). A multivariate regression analysis was used to assess the correlation between performed realignment procedures and FAO values. RESULTS: Mean preoperative FAO was 4.4% (95%CI = 1.4-7.5). The number of osseous realignment procedures needed was found to correlate positively and significantly with FAO (p = .001). The number of osseus procedures needed was significantly higher in patients with valgus malalignment (p = .009). Patients with valgus malalignment needing a medial column procedure had a relative risk of 6.3 when compared to varus malalignment patients (p = .02). CONCLUSION: The number of additional bony realignment procedures performed at the time of TAR significantly correlated with preoperative FAO and that the number of osseus procedures needed was significantly higher in patients with valgus malalignment. Such biometric tools may enhance the preoperative assessment and surgical planning for patients undergoing TAR, with the potential to optimize surgical outcomes.

Accuracy of patient-specific instrumentation in total ankle arthroplasty: A comparative study.

BACKGROUND: Patient-specific instrumentation (PSI) for TAA is a novel technology with several potential benefits. The primary goal of this study was to compare the use of PSI with the standard referencing guide (SRG) in regards to accuracy of tibial implant positioning. Operative time, fluoroscopy time and accuracy of PSI preoperative reports were also evaluated. METHODS: A retrospective analysis of 99 patients who underwent a primary TAA with the INFINITY prosthesis (Wright Medical, Memphis, TN) was performed. Patients were divided in two groups based on the type of instrumentation used during the TAA (75 in the PSI group vs 24 in the SRG group). There was no significant difference between groups in regards to age at the time of surgery (P=0.122), sex (P=0.138), number of concomitant procedures performed during surgery (P=0.567) and etiology (P=0.841). However, preoperative deformity was significantly smaller in the PSI group (P=0.002). RESULTS: Tibial implant positioning was similar between groups. In the coronal plane, the absolute deviation of the tibial implant from the intended alignment was 1.7±1.4° for the SRG and 1.6±1.2° for PSI (P=0.710). In the sagittal plane, the absolute alignment deviation of the tibial implant was 1.8±1.4° for the SRG and 1.9±1.5° for PSI (P=0.675). Operative time (167 vs 190min, P=0.040) and fluoroscopy time (85 vs 158s, P<0.001) were significantly decreased in the PSI group. The PSI preoperative plan report correctly predicted the implant size in 73% of cases for the tibial component and in 51% of cases for the talar component. CONCLUSIONS: PSI provided similar tibial component alignment as standard instrumentation. Additionally, PSI preoperative plan reports were poor predictors of implant sizing. Therefore, the final decision should always be based on surgeon's experience in order to prevent errors in implant sizing and positioning. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Conversion of ankle autofusion to total ankle replacement using the Salto XT revision prosthesis.

Few reports in the literature have described the conversion of a surgically fused ankle to a total ankle replacement. The takedown of an autofusion and conversion to a prosthesis has not been described. We report the case of a patient with severe rheumatoid arthritis with an ankle autofusion fixed in equinus and severe talonavicular arthritis that was converted to ankle replacement using the Salto XT revision system. We describe the reasons why the decision was made to perform total ankle arthroplasty while concomitantly fusing the talonavicular joint, and discuss the rationale of the various surgical treatment options considered. We describe the clinical and radiographic outcomes achieved in this case. At 12 months post-operatively the patient reported significant reduction of pain, increased FAOS scores and had increased ankle range of motion.

Equivalent pain relief with and without resection of the posterior tibial tendon in adult flatfoot reconstruction.

Transfer of the flexor digitorum longus (FDL) is indicated to compensate for the loss of posterior tibial tendon (PTT) function in the treatment of adult acquired flatfoot deformity (AAFD). The aim of this study was to determine the effect of PTT resection on pain relief following surgical treatment of stage II AAFD. A retrospective review of patients who underwent surgical treatment for stage II AAFD was performed. Patients were divided into two groups based on whether the degenerated PTT was resected or left in situ. A visual analog scale (VAS) score for pain was recorded for each patient preoperatively. Concomitant surgical procedures and the incidence of postoperative pain were also reported for each group. Deformity correction was assessed with standard weight-bearing radiographs. Thirty-four patients with a mean follow-up of 14 months were included in the study. There was no difference in preoperative VAS pain scores, and patients in both groups demonstrated excellent pain relief postoperatively. Five patients in the PTT resection group and one patient in the PTT in situ group reported lateral-sided foot pain postoperatively. Resection of the PTT did not significantly affect postoperative pain relief. Future prospective studies are needed to determine whether resection of the degenerated PTT is necessary at the time of surgery for stage II AAFD.

Outcomes of Total Ankle Arthroplasty After Reoperation due to Gutter Impingement.

Gutter impingement is one of the most common causes of subsequent surgery after total ankle arthroplasty (TAA). Although gutter debridement has been reported to resolve preoperative symptoms early on, persistent pain after surgery, recurrence, and poor functional outcome scores have been described in patients who have undergone reoperation for gutter debridement. The cause of gutter impingement after TAA is multifactorial, and a better understanding of its causes and optimal surgical techniques for intervention is needed.

An evaluation of the total ankle replacement in the modern era: a narrative review.

Background and Objective: Total ankle replacement has become an increasingly popular surgical procedure for treatment of end-stage ankle arthritis. Though ankle arthrodesis has historically been considered the gold standard treatment, advancements in implant design, functional outcomes, and survivorship have made total ankle replacement a compelling alternative. Particularly, in the past 20 years, total ankle replacement has undergone tremendous innovation, and the field of research in this procedure continues to grow. In this review, we aim to summarize the history, evolution, advancements, and future directions of total ankle replacement as described through implant design, indications, surgical procedures, complications, and outcomes. Methods: Literature searches were conducted in PubMed to identify relevant articles published prior to March 2023 using the following keywords: "total ankle replacement", "total ankle arthroplasty", and "total ankle". Key Content and Findings: Total ankle replacement has demonstrated significant improvements in surgical technique, implant design, survivorship, and clinical and functional outcomes in the modern era. The procedure reports high patient satisfaction, low complication rates, and improved functional abilities that challenge the current gold standard treatment for ankle arthritis. Conclusions: Though there are areas of improvement for total ankle replacement, the procedure demonstrates promising outcomes for patients with end-stage ankle arthritis to improve pain and functional abilities. Research studies continue to explore various the facets of total ankle replacement, including outcomes, risk factors, novel techniques and modalities, and complications, to direct future innovation and to optimize patient results.

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.

Lessons From Revision Total Ankle Replacement: Tibias Fail Earlier, and Taluses Fail Later (and Fail Again).

BACKGROUND: The literature on survivorship and outcomes after revision total ankle replacement (TAR) in the modern era is limited. This study aimed to describe the timing to revision and survivorship after revision TAR. We hypothesized that tibial-sided failures would occur earlier after the primary TAR, and secondary revisions after failure of revision TAR would occur more due to talar-sided failures than tibial-sided failures. METHODS: This is a single-institution retrospective study of TAR patients with minimum 2-year follow-up. Revision TARs (defined as exchange of tibial and/or talar components) for aseptic causes with any implant were included. Etiology of failure necessitating revision and ultimate outcomes after revision (survival of TAR revision, additional revision, conversion to fusion, and below-knee amputation [BKA]) were recorded. RESULTS: There were 46 revision TARs, with mean age of 60.6 (range: 31-77) years and mean 3.5 years' follow-up postrevision. Revisions for tibial failure occurred significantly earlier (n = 22, 1.3 ± 0.5 years after index procedure) than those for talar failure (n = 19, 2.3 ± 1.7 years after index procedure) or combined tibial-talar failure (n = 5, 3.4 ± 3.4 years after index procedure) (P = .015). Revisions for tibial-only failure had better survival (95.5%) than revisions for talar or combined tibial-talar failures: 26% of talar failures and 20% of combined tibial-talar failures underwent ≥1 revisions. Of the 6 additional revisions after failure of the talar component, 1 ultimately underwent BKA, 2 were converted to total talus replacement, 2 were revised to modular augmented talar components, and 1 was treated with explant and cement spacer for PJI after the revision. CONCLUSION: TAR tibial failures occurred earlier than talar failures or combined tibial-talar failures. Revisions for talar failures and combined tibial-talar failures were more likely to require additional revision or ultimately fail revision treatment. This is important given the consequences of talar implant subsidence, bone necrosis, loss of bone stock, and limited salvage options. LEVEL OF EVIDENCE: Level IV, case series.

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.

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.

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.

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.

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.

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.

Influence of Isolated Talonavicular and Subtalar Joint Arthrodesis on Hindfoot Kinematics and Range of Motion During Cadaveric Gait Simulation.

BACKGROUND: Isolated subtalar and talonavicular joint arthrodeses have been associated with adjacent joint arthritis and altered hindfoot kinematics during simplified loading scenarios. However, the effect on kinematics during dynamic activity is unknown. This study assessed changes in subtalar and talonavicular kinematics after isolated talonavicular (TNiso) and subtalar (STiso) arthrodesis, respectively, during stance simulations. METHODS: Fourteen midtibia specimens received either a TNiso or STiso arthrodesis, with 7 randomized to each group. A 6-degree-of-freedom robot sequentially simulated the stance phase for the intact and arthrodesis conditions. Bootstrapped bias-corrected 95% CIs of the talonavicular and subtalar joint kinematics were calculated and compared between conditions. RESULTS: The TNiso decreased subtalar inversion, adduction, and plantarflexion in late stance (P < .05). The subtalar range of motion in the sagittal and coronal planes decreased by 40% (P = .009) and 46% (P = .002), respectively. No significant changes in talonavicular joint kinematics were observed after isolated subtalar arthrodesis; however, the range of motion was reduced by 61% (P = .007) and 50% (P = .003) in the coronal and axial planes, respectively. CONCLUSION: In this model for arthrodesis, changes in subtalar kinematics and motion restriction were observed after isolated talonavicular arthrodesis, and motion restriction was observed after isolated subtalar arthrodesis. Surprisingly, talonavicular kinematics did not appear to change after isolated subtalar arthrodesis. CLINICAL RELEVANCE: Both joint fusions substantially decrease the motion of the reciprocal adjacent joint. Surgeons should be aware that the collateral costs with talonavicular fusion appear higher, and it has a significant effect on subtalar kinematics during the toe-off phase of gait.

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.

Outpatient Total Ankle Arthroplasty (TAA) as a Rising Alternative to Inpatient TAA: A Database Analysis.

BACKGROUND: There is growing evidence that total ankle arthroplasty (TAA) can safely be performed as an outpatient procedure, with the benefit of decreased health care expenses and improved patient satisfaction. The purpose of our study was to compare readmissions, arthroplasty failures, infections, and annual trends between outpatient and inpatient TAA using a large publicly available for-fee database. METHODS: The PearlDiver Database was queried to identify outpatient and inpatient TAA-associated claims for several payer types from January 2010 to October 2021. Preoperative patient characteristics and annual trends were compared for inpatient and outpatient TAA. International Classification of Diseases, Ninth and Tenth Revision, diagnosis codes were used to identify infections and arthroplasty failures. Complications rates were compared after matching patients by age, gender, and the following comorbidities: diabetes, smoking, congestive heart failure (CHF), hypertension (HTN), obesity, and chronic kidney disease (CKD). RESULTS: A total of 12 274 patients were included in the final exact-matched analysis for complications, with 6137 patients in each group. Outpatients had a significantly lower rate of readmission within 90 days (2.6% vs 4.0%, P < .001), arthroplasty failure (4.1% vs 6.9%, P < .001), and infection (2.4% vs 3.1%, P = .015). Among database enrollees, outpatient TAA has risen in proportion to inpatient TAA from 2019 to 2021. CONCLUSION: Outpatient TAA had lower rates of risk-adjusted readmission, arthroplasty failure, and infection compared to inpatient TAA. LEVEL OF EVIDENCE: Level III, retrospective comparative database study.