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: Midfoot/Forefoot Introduction/Purpose: Cartiva (Wright Medical Group N.V.) was developed as an implantable interposition device for the treatment of hallux rigidus. It is performed along with a limited cheilectomy and serves as a joint preserving alternative to arthrodesis. In some patients, we have noticed gradual decreases in the joint space after surgery with Cartiva, presumably representing subsidence of the implant. The aim of this study is to report a radiographic analysis of visible joint space in surgical cases of hallux rigidus where dorsal cheilectomy and Cartiva were used. Methods: A prospectively collected patient database was queried for CPT code 28291 and those patients in which Cartiva was implanted were determined. The pre-operative and post-operative radiographs were analyzed for hallux rigidus grade, and measurements of visible joint space prior to and after Cartiva was implanted were performed at two weeks, one month, three months, and six months post-operatively. The percentage of visible joint space increase or decrease after implantation of Cartiva was calculated for each post-operative time point. Results: A total of 79 Cartiva were implanted in 74 patients between April 2017 and Sept 2018. The procedure was performed for Grade I hallux rigidus in 11% of patients (n=9), 66% grade II (n=52), 23% grade III (n=18). Mean pre-operative visible joint space measured 1.1 mm (n=79). Visible joint space measured at two weeks post-surgery was 2.2 mm (n=74); one month, 1.6 mm (n=65); three months, 1.2 mm (n=64); six months, 1.0 mm (n=30). Implantation of Cartiva resulted in 100% increase in visible joint space compared to pre-operative measurements at two weeks post-surgery, 45% increase at one month, 9% at three months, and a 9% decrease in visible joint space at six months. Conclusion: Cartiva implantation and limited cheilectomy for patients with symptomatic hallux rigidus provided a 100% increase in visible joint space on radiographs taken two weeks post operatively. However at six months post-surgery there was an overall 9% decrease in visible joint space presumably representing a subsidence of the Cartiva implant with time.

Objective: To evaluate the reliability of grading subtalar (ST) arthrosis on lateral weightbearing radiographs in a heterogenous patient population using the Kellgren-Lawrence (KL) scale, correlate these findings to advanced imaging (CT and/or MRI), and to validate a novel scale. Materials and methods: A random collection of 40 lateral weightbearing radiographs presenting to a foot and ankle clinic were reviewed by nine multi-disciplinary independent reviewers. Interobserver reliability was assessed for KL scores. A musculoskeletal radiologist graded available advanced imaging on all 40 radiographs and the advanced imaging scores were correlated to the radiographic scores. A novel scoring system was created and tested for interobserver reliability. Results: There was overall fair reliability amongst reviewers with the traditional KL score, kappa = 0.26. The best agreement was seen amongst those deemed to have a grade 0, with only moderate agreement (k = 0.50). There was only fair interobserver reliability with severe, Grade 4 scores (k = 0.28). Radiographic scores did have moderate correlation with advanced imaging (r = 0.56). A new, simple grading system was proposed and its interobserver reliability was improved substantially (kappa = 0.68). Conclusions: The KL scoring system is not applicable to the subtalar joint. The new NSS grading system has improved reliability. Radiographs only had moderate correlation to advanced imaging. Further studies are warranted to correlate clinically.

Background: Avascular necrosis of the distal tibial plafond following ankle trauma is an underreported and potentially devastating phenomenon. Beyond conservative treatment options, surgical intervention has been limited to ankle arthrodesis, which sacrifices motion and may have longterm sequellae for adjacent hindfoot joints. Total ankle replacement has been historically contraindicated. Unipolar allograft reconstruction provides an option for joint salvage. We present a literature overview, implantation technique, and two cases utilizing matched unipolar distal tibial allograft. Methods: Two younger patients underwent distal tibia allograft reconstruction for tibial plafond collapse due to post-traumatic avascular necrosis. They were followed to assess for clinical improvement and radiographic graft subsidence. Results: Both patients returned to work and activity. One patient had no graft subsidence at four years, but the other patient became symptomatic with graft subsidence at one year. Conclusions: Distal tibia allograft reconstruction can be utilized as a joint salvage surgery for post-traumatic avascular necrosis with collapse of the tibial plafond in younger patients that prefer an alternative to arthrodesis. Results may be mixed and necessitate an engaged, activated patient. Level of evidence: IV. (C) 2018 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

BACKGROUND:Calcaneal osteotomies are commonly used to correct varus hindfoot alignment in patients with symptomatic cavovarus deformity. Translational, closing wedge, and Malerba-type osteotomies have been implicated in the development of tarsal tunnel syndrome and neurologic injury to branches of the tibial nerve. The authors hypothesized that there would be minimal clinically important injury to the tibial nerve by performing a translational calcaneal osteotomy from a medial approach.METHODS:All patients undergoing a cavovarus reconstruction by a single surgeon were identified. Patients were included if they underwent a lateralizing calcaneal osteotomy via medial approach. Demographics, operative reports, and clinic notes were reviewed to identify concomitant procedures performed, incidence of postoperative tarsal tunnel syndrome, complications, and preoperative and postoperative nerve examinations. Postoperative radiographs were reviewed for location of the osteotomy relative to the posterior tubercle.RESULTS:Twenty-four patients underwent lateralizing calcaneal osteotomy via a medial approach. Of the osteotomies, 83.3% (20/24) were in the middle third of the calcaneus, with a mean of 11.6-mm translation. No patients developed postoperative tarsal tunnel syndrome or tibial nerve palsy.CONCLUSION:Lateralizing calcaneal osteotomy performed via a medial approach had a clinically negligible incidence of neurologic injury. Adequate translation was achieved to obtain correction of varus hindfoot deformity. The authors believe that there is less direct and less percussive injury to branches of the tibial nerve when performing the osteotomy from medial to lateral. This technique may represent an operative strategy to minimize risk to the tibial nerve and reduce neurologic deficit following cavovarus reconstruction.LEVEL OF EVIDENCE:Level IV, case series.

Introduction: Due to advances in technology, segmental gait analysis of the foot is now possible and can elucidate hindfoot deformity in persons with posterior tibial tendon dysfunction (PTTD). This study evaluated the motion of the hindfoot and ankle power following surgical reconstruction for PTTD utilizing a segmental foot model during gait. Materials and Methods: Twenty patients who underwent posterior tibial tendon reconstruction for Stage 2 PTTD using transfer of the flexor digitorum longus tendon to the navicular tuberosity, reconstruction of the calcaneo-navicular ligament complex, and a medial displacement calcaneal osteotomy were evaluated at a minimum followup of I year. Three-dimensional gait analysis was performed utilizing a 4-segment foot model. Temporal-spatial parameters included walking velocity, cadence, step length, and single support time. Sagittal, coronal, and transverse hindfoot motion with respect to the tibia/fibula and ankle power was calculated throughout the gait cycle. Results: Walking velocity, cadence, and step length were not significantly different between the study subjects and the normal control group. Study patients did show a significantly smaller single support time on both the affected and unaffected limbs compared to controls. There was no statistical difference in plantarflexion-dorsiflexion, varus-valgus, or ankle push-off power between the affected and unaffected sides of the study subjects, or between the affected side and the controls. Conclusion: In this preliminary postoperative study, surgical reconstruction for PTTD effects quantifiable objective improvement in walking velocity, hindfoot motion and power.