Background: Nonunion following naviculocuneiform (NC) joint arthrodesis is a well-recognized complication. Most studies reporting nonunion rates involve a limited number of cases or focus on a single disease entity. Moreover, there is variation between studies with regard to the number of articular facets included in the arthrodesis as well as the fixation construct used, with no clear evidence indicating how these factors influence union. This study, using the largest cohort to date, aims to investigate the nonunion rate following NC joint arthrodesis and to identify demographic and surgical factors associated with nonunion.Methods: One hundred ten feet in 100 patients who underwent NC joint arthrodesis between 2016 and 2023 at a single institution were retrospectively identified. The indications for surgery included osteoarthritis (n = 89), deformity (n = 10, flatfoot or cavus), and rheumatoid arthritis (n = 11). Charcot arthropathy was excluded. Nonunions were defined by radiographic review and were further categorized as symptomatic or asymptomatic. Demographic and surgical factors, including isolated medial NC facet vs multiple NC facet arthrodesis, fixation construct, concurrent arthrodesis of other joints, and type of bone graft used, were included in the regression analysis to determine their association with nonunion.Results: The overall nonunion rate was 27.3% (30/110 cases), with 15.5% (17 cases) presenting as symptomatic nonunions. There were no significant differences in the nonunion rates among different indications for NC arthrodesis (P = .9404). A statistically significant difference in nonunion rates was observed between patients undergoing isolated medial facet arthrodesis (38.2%) and those undergoing multiple facet arthrodesis (16.4%, P = .0102). After performing multivariate analysis adjusted for potential confounders, age (OR 1.08, 95% CI: 1.0-1.16, P = .0456), diabetes (OR 12.70, 95% CI: 1.24-130.3, P = .0324), and isolated medial NC facet arthrodesis (OR 17.48, 95% CI: 3.23-94.54, P = .0009) were significantly associated with nonunion. No significant association with nonunion was identified based on the type of bone graft, fixation construct, or whether concurrent arthrodesis of adjacent foot joints was performed.Conclusion: This study demonstrates a significant rate of nonunion following NC joint arthrodesis, exceeding that previously reported. We found that the rate of nonunion significantly increased in arthrodeses involving only the medial NC facet as compared to those including multiple NC facets.

Category: Ankle Introduction/Purpose: Peroneal tendon tears are a common cause of lateral ankle pain. When the tear involves more than 50% of the tendon’s cross-sectional area, the treatment algorithm recommends tenodesis of the torn peroneal tendon to the intact peroneal tendon. Previous assessments in the literature of functional outcomes after peroneal tenodesis have widely used the American Orthopedic Foot and Ankle Score (AOFAS) survey as a measurement tool. However, this score was not designed for patient-reported outcomes and its validity and reliability have been questioned. The Medical Outcomes Shortform-36 (SF-36) and PROMIS are tools that have been extensively studied and validated. We sought to assess patient outcomes after peroneal tenodesis using validated tools: SF-36, PROMIS and AOS Disability scores. Methods: Prospective data was collected on patients undergoing peroneal tenodesis for peroneal tendon tears, and who follow up of at least one year. Patients who underwent concomitant procedures (hindfoot fusion, total ankle arthroplasty) were excluded from the study. Baseline patient-reported outcomes (PRO) scores were obtained preoperatively and compared to scores obtained at one year postoperatively. Results: We identified seventeen patients who underwent peroneal tenodesis for peroneal tendon tears. Average age was 62.1 years. SF-36 Physical Function scores increased from an average of 42.0 preop to 60.0 postop (p = 0.0095). PROMIS scores increased from 40.3 to 42.7 (p = 0.3049). There was no statistically significant improvement in postoperative SF-36 Pain scores (p = 0.3216). AOS Disability Scores dropped from 49.6 preop to 38.2 postop (p = 0.3178). AOS Pain scores decreased from 40.7 to 27.0 (p = 0.1779). Total AOS score decreased from 45.1 to 32.6 (p = 0.2204). Conclusion: The SF-36 Physical Function score, which is a validated outcome measure, showed statistically significant improvement postoperatively. Some of the other PROs for peroneal tenodesis failed to show statistically significant improvements, and this is most likely due to low numbers, rendering the cohort somewhat under-powered. Though the data is preliminary, the non-significant scores trended toward improvement. Despite the preliminary nature of this study, satisfactory outcomes of peroneal tenodesis using validated patient-reported outcome scores are demonstrated for the first time. Further study is underway to enlarge the scope of this investigation.

Category: Ankle, Ankle Arthritis, Basic Sciences/Biologics, Hindfoot Introduction/Purpose: Several studies on the effect on gait of total ankle arthroplasty (TAA) have demonstrated significant functional improvement post-operatively, compared to the patients’ preoperative function. While there are many post-operative studies showing abnormalities of gait in patients who have had ankle arthrodesis, there are very limited published data in ankle fusion which compare post-operative gait to the patients’ own preoperative function. Moreover, there are no published correlation of those gait changes with patient reported outcomes. Methods: Twenty-six consecutive ankle arthrodesis patients were prospectively studied, with pre- and post-operative three- dimensional gait analysis. Kinematic data were collected at 100 Hz with a twelve-camera digital Vicon motion capture system, and two OR6-5 AMTI force plates. Patients walked barefoot at a self-selected speed over a 10-meter walkway. A minimum 20 gait cycles were used for averaging and statistical analysis for temporal-spatial and kinematic parameters and a minimum of five force plate readings for kinetic parameters. Gait parameters were collected for both operated and unaffected limbs (i.e. control). Demographic data were compiled. Prospectively collected patient-reported outcomes included SF-36, VAS, AOFAS scores, which were repeated annually postoperatively. Results: Mean age was 56 (19 – 80) years, BMI 29.7 (18.6 - 45.6), and follow-up 21.9 (12 - 69) months. There were multiple objective parameters of gait which showed statistically significant functional improvements compared to preoperative performance. Temporal-spatial: Improvements were detected in walking speed, step length and cadence; single and double limb support time. Kinematic parameters: Increase in maximum plantarflexion, decrease in maximum dorsiflexion, but total sagittal range of motion was not diminished, and slightly increased (mean 1.8 degrees). The preservation of total sagittal motion after arthrodesis suggested either precise postoperative compensation by the hindfoot, or that most of the preoperative motion was already occurring in the surrounding hindfoot joints. Kinetic parameters: Improvement in ankle moment and hip power were detected. Patient reported outcomes (table) Conclusion: Ankle arthrodesis improves gait in end-stage arthritis, as demonstrated by statistically significant improvements in multiple, objective parameters. Moreover, the increase in sagittal plane motion of the hindfoot, presumed in the literature to be compensatory to the arthrodesis, was shown to be present pre-operatively, as well, suggesting it is also an effect of tibiotalar stiffness due to end-stage arthritis. Improvements in gait corresponded to clinical improvements as well, as demonstrated by improvements in patient reported outcomes in this population. Biomechanical improvements corresponded to clinical outcomes.

Category: Hindfoot Introduction/Purpose: Tears of the peroneal tendons are a frequent cause of pain and disability. Surgical intervention is frequently warranted for symptoms that persist despite conservative management. Surgical treatment can include repair, local tendon transfers (i.e. peroneus longus to brevis transfer), or allograft reconstruction. While allograft reconstruction has been advocated for reconstruction of even a single peroneal tear, the indications are not widely agreed upon. The hypothesis of this study was that reconstruction with excision of the diseased tendon and transfer to the adjacent peroneal tendon produces significant improvements in both pain and function. Methods: Patients that underwent surgical intervention for peroneal tendon pathology at a single institution by a fellowship- trained foot and ankle orthopaedic surgeon were prospectively followed. Operative reports were reviewed to identify patients that underwent peroneal reconstruction with excision of the diseased tendon and local tendon transfer for chronic, severe peroneal tearing. Preoperative AOFAS and Visual Analog Scores (VAS) were obtained as a baseline and then repeated at one year following surgery. Statistical analysis was performed to compare preoperative and postoperative pain and function. Results: 14 patients were identified that underwent peroneal reconstruction without allograft tendon using reconstruction with excision of the diseased tendon and transfer to the adjacent peroneal tendon. Average age was 41.2 years (range 23-61 years) and average follow-up was 26.7 months (range 12-67 months). At one year, patients’ AOFAS scores improved from 51.9 +/- 12.2 to 90.7 +/- 3.4 (p<0.0001). VAS scores decreased from 6.5 +/- 1.2 to 1.6 +/- 0.9 (p<0.0001). There was 100% survivorship of the reconstruction procedure at one year. One patient underwent an allograft reconstruction for recurrent tearing five years after initial surgery and no other patients underwent a revision procedure. Demographic data and functional scores before and after surgery are displayed in Table 1. Conclusion: Peroneal reconstruction performed via excision of the torn tendon and local transfer to the adjacent tendon results in clinically significant improvement in pain and function without the need for allograft tissue. Patients may be counselled that peroneal transfer for chronic, severe tears leads to significant improvement and excellent clinical outcomes. This study shows excellent results can be obtained with local tendon transfer and the authors advocate this procedure to avoid the cost and risk of allograft transplant.