Early Osteolysis and Component Revision of CADENCE Total Ankle Arthroplasty at Midterm Follow Up

Category: Ankle Arthritis; Ankle Introduction/Purpose: Total ankle arthroplasty (TAA) for the treatment of end-stage ankle arthritis has continued to grow in popularity as a favorable alternative to ankle arthrodesis. Amongst the fourth-generation implants released over the past decade is the CADENCE Total Ankle System (CTAS) which became available for clinical use in 2016. Our previous publication revealed a concerning incidence of radiographic osteolysis of the CADENCE tibial component interface at short-term follow-up of 24 months. Though there were limited cases of symptomatic loosening or component revision in this report, there was concern this trend may worsen with longer follow-up. The purpose of this study was to evaluate the radiographic and clinical outcomes of TAA with the CTAS, with a minimum of 1-year follow-up. Methods: This single-center retrospective study evaluated 63 consecutive patients who underwent TAA with the CTAS between August 2016 and October 2021 by a single fellowship-trained foot and ankle surgeon and co-design surgeon. Patients were included in our study on the basis of at least one year of clinical and radiographic follow-up; there were no other exclusion criteria. Results: Fifty-four TAA cases utilizing the CTAS in 50 patients were included in the current study. Preoperatively, eleven ankles had neutral alignment, 18 ankles demonstrated varus alignment, and 25 ankles demonstrated valgus alignment. Twelve patients underwent staged procedures for management of severe coronal plane deformity. Radiographic parameters changed significantly preoperatively to postoperatively. At final follow-up, PPL was demonstrated in 39 (72.2%) ankles in this cohort. Symptomatic PPL was present in 13.0% of ankles in this cohort. Talar subsidence was observed in 7 ankles within our cohort. Nine ankles underwent subsequent operations related to TAA complications. Seven ankles underwent revision procedures, resulting in a final implant survivorship of 87.0%. Four ankles, 7.4% underwent non-revision reoperations. No additional complications were encountered within this cohort. Conclusion: In this study of 54 CADENCE TAA, we observed a high rate of component loosening and bone interface osteolysis over time. This ultimately led to poorer implant survivorship over time and a higher than acceptable revision rate. Though the lead author is a co-designer of the CADENCE implant, we believe it prudent to share our clinical findings and experience as we all gain further knowledge and understanding about implant design and TAA. Based upon our results, we have abandoned use of this prosthesis as the midterm results fail to achieve parity with other TAA systems available on the market

Successful Limb Salvage Reconstruction Using Bulk Femoral Head Allograft

Category: Ankle Introduction/Purpose: The use of femoral head allografts in salvage surgeries for lower extremity reconstruction help address surgical problems of large bone deficits. There are very few publications and mixed results in the literature as to the outcomes of this salvage procedure. These limb salvage procedures involve significant surgical complexity with the end goal of retaining a stable, brace-able lower extremity. The purpose of this retrospective review is to report the results and utility of bulk femoral head allograft for limb salvage including time to weight bearing, CT confirmed fusion time, reoperation rates, and ultimate limb salvage success. Additionally, this article categorizes femoral head surgical preparation, adjunct biologics use, fixation constructs, and dissection techniques used. Methods: Patients who underwent reconstructive limb salvage surgery using femoral head allografts over a 5-year period (2015- 2020) were identified. The surgeries were among 5 different fellowship-trained surgeons at a single institution. Indications included post-traumatic AVN, Charcot ankle, revisional surgery, and failed total ankle replacement. Femoral heads were used in either ankle fusions alone or in tibiotalocalcaneal fusion. Time to weight bearing, CT fusion time, reoperations, and ultimate limb salvage were recorded. Reoperations were reported minor if involved partial HWR, superficial I&Ds, or exostosis/HO removal. Major reoperations were defined as full revision surgery/failure of femoral head construct, placement of antibiotic rods for deep infection, or BKA. Limb salvage was defined as being successful if the patient was walking with or without bracing at the last follow-up. Results: Twenty-three cases were identified with 13 performed for failed total ankle replacements, 7 post-traumatic avascular necrosis of the talus, and 3 neuropathic Charcot ankles. The average radiographic follow-up time was 665 days with an average time to weight bearing of 86.48 days. 18/23 patients had CT confirmation of femoral graft union with an average time to union of 461.92 days. 9 patients were found to have less than 50% graft incorporation at the last follow-up. There were 9 reoperations recorded, 8 minor and 1 major. All patients were chart documented stable with independent weight bearing either with or without a brace on the last clinic follow-up. Conclusion: Limb salvage in cases of large bone defects can be very challenging. We report a high success rate of limb salvage using bulk femoral head allograft. Complete fusion of bulk femoral head allograft although desirable, was not necessary to maintain limb salvage in this retrospective study. Patients were able to weight bear and maintain the integrity of the bulk allograft despite the lengthy time to achieve fusion in cases where fusion was achieved. This study highlights that bulk femoral head allograft can offer excellent salvage options with a high degree of success in complex limb salvage reconstruction

1st to 2nd metatarsal base cross-screw in the modified Lapidus proc

First tarsometatarsal (TMT) arthrodesis or the modified Lapidus (ML) is a common procedure utilized by foot and ankle surgeons for the management large bunion deformities, particularly in the presence of medial column instability. The purpose of the present anatomic study was to assist surgeons in preoperative planning for ML procedure utilizing the first metatarsal to second metatarsal cross-screw technique by assessing the average length of screw guidewire placed bi-cortically through the first metatarsal and second metatarsal at a location specific to the ML procedure with metatarsal to second metatarsal cross-screw technique. This was a cadaveric study utilizing 20 fresh-frozen below-the-knee specimens. After dissection, joint preparation, and stabilization, a cannulated 4.0 screw was then placed across the first and second metatarsal bases from medial to lateral starting 1 cm distal to the 1st TMT joint. Once appropriate length and orientation was achieved the guidewire was measured using a cannulated depth gage and values were then recorded on a spreadsheet and analyzed. Amongst the 20 specimens the mean guidewire length was found to be 34 mm +/- 3.2 mm. The median guidewire length was found to be 34 mm (range: 29 – 41 mm). The present anatomic study defined the mean and median lengths of a first metatarsal to second metatarsal screw utilized for medial column stabilization and spot weld arthrodesis in the ML procedure

Intellectual Property and Royalty Payments Among Foot and Ankle Surgery Fellowship Faculty

Category: Other Introduction/ Purpose: Faculty of the American College of Foot and Ankle Surgeons and American Orthopedic Foot and Ankle Society fellowship programs are uniquely positioned to provide advanced clinical and surgical training to fellows. One aspect of this training may include product design and mentorship through the associated intellectual property (IP) and patent timeline. This study describes the payments received and IP held among foot and ankle surgery fellowship faculty. Methods: A review of foot and ankle surgeons with royalties or license payments disclosed on the CMS Open Payments Database from 2014-2020 was conducted. Members with payments were then cross-referenced with the US Patent Full-Text Database to identify patents held. Fellowship affiliation, practice location, patent office, number of patents, citations, patent h-index, type of patent, and yearly payment values were recorded. Results: Among the 2,801 surgeons, 53 fellowship affiliates and 46 non-affiliates maintained at least one patent and royalty/license payment. A total of 576 patents and 19191 citations were assessed. The median number of patents and citations held by fellowship faculty was 3 and 60, respectively, while the median total payment value reached $165197.09. Fixation devices comprised most of the patents and citations. Payment value positively correlated with number of patents held (p=0.01), citations (p=0.007), and patent h-index (p=0.01) among fellowship-affiliated surgeons. Conclusion: Foot and ankle surgery fellowship faculty payments for IP is associated with the number and citability of patents held. While a small proportion of faculty were paid for intellectual property, the number of patents held and citations was comparable to other specialties

Fibuloplasty: Distal fibular reconstruction performed in conjunction with ankle fusion conversion to implant arthroplasty

Ankle arthrodesis (AA) represents an effective, dependable procedure for the treatment of end-stage osteoarthritis of the ankle. While AA offers the benefits of pain relief and some preservation of function, it sacrifices ankle motion which over time may lead to progressive degeneration of the adjacent joints of the hindfoot. Historically, salvage options for failed or painful AA included revisional AA, tibiotalocalcaneal arthrodesis, pantalar arthrodesis, and amputation. More recently the conversion of AA to total ankle arthroplasty (TAA) has been shown to be a viable salvage option which, unlike early salvage options, restores motion and function to the ankle and may help to avoid the need for periarticular arthrodesis. A unique challenge faced with AA conversion to TAA includes instances where fibular resection was performed during the primary procedure. Previous studies have evaluated the viability of conversion to TAA in patients with AA and prior fibular resection, with most authors stating that the absence of the lateral malleolus is an absolute contraindication to TAA. In contrast, newer studies have reported success with various techniques to restore the lateral fibular strut and perform the conversion of AA to TAA. This case report describes a unique approach of AA conversion to TAA utilizing a custom, fibular prosthesis to restore lateral stability following prior AA with fibular resection

Increased Union Rates in Subtalar Joint Arthrodesis with Hybrid Nitinol Dynamic Compression Device

Category: Hindfoot Introduction/Purpose: Subtalar joint arthrodesis (STJA) is a well-established and widely accepted surgical procedure utilized for the treatment of numerous hindfoot conditions. Several fixation constructs in STJA have been described in the literature. With the current advancements in orthopedic technology, new devices utilizing nitinol elements have been developed in an effort to maintain sustained compression in the event of bony resorption which may occur during arthrodesis healing. The primary aim of our study is to introduce a hybrid nitinol dynamic compression (HNDC) device for STJA which provides dynamic compression without proximal locking fixation and compare union rates with a previous nitinol dynamic compression nail (NDCN) as well as a standard two-compression screw fixation construct. The secondary aim was to compare hardware removal rates amongst the three cohorts. Methods: From May 2019 through February 2022, 26 consecutive patients treated with a novel HNDC for STJA were compared to 15 patients treated with NDCN for STJA and 41 patients undergoing STJA using a two-compression screw fixation method. Patients were included in our study if they were greater than 18 years of age, underwent STJA with the use of one of the internal fixation constructs under investigation, and had a minimum 1-year follow-up with radiographs; there were no other exclusion criteria. Arthrodesis sites were augmented with autologous bone graft with or without bone graft substitute in all patients. Standard postoperative protocols were used amongst all three cohorts. Primary outcomes included subtalar joint union rates determined by radiographic and clinical assessment. The incidence of hardware removal was recorded and compared between groups. Patient-specific risk factors were studied to assess any potential negative effects on STJA union rates. Results: Union rates between the HNDC device and the NDCN group did not demonstrate a statistically significant difference at final follow-up. There was a statistically significant difference in union rates between subjects who underwent STJA with the HNDC device versus those who underwent STJA with a two-compression screw construct. Furthermore, there was a statistically significant increase in union rates in subjects who received nitinol dynamic compression fixation devices, HNDC or NDCN, versus standard compression screws. There was not a statistically significant difference in hardware removal rates among the 3 cohorts. No significant relationship was seen between smoking, diabetes, or alcohol consumption and union rates. Conclusion: Our data supports the HNDC device to have superior union rates to the two-screw fixation group. In addition, the HNDC device provides improved union rates, though not statistically significant, when compared to the NDCN. Furthermore, the HNDC device was found to have lower rates of hardware removal when compared to the two-screw fixation and the NDCN groups though this was not statistically significant. The early results of this HNDC device for STJA are encouraging and appear to offer a further improved alternative fixation construct with excellent union rates and minimal complications

Depth variations of second and third tarsometatarsal joints during dorsal compression staple fixation using two different bridge lengths: an anatomic study

Fusion of the second and third tarsometatarsal joints is utilized for various arthritic pathologies and traumatic conditions. A cadaveric study using 20 fresh-frozen transtibial specimens were used for a stimulated arthrodesis study. Half of the specimens underwent drilling via drill guide for a respective 15 mm and 20 mm dorsal bridge length staples. Each drill guide was placed equidistant from each joint at 7.5 mm for the 15 mm bridge length and 10 m for the 20 m bridge length, then drilled bicortically in parallel with the joint line. For the 15 mm bridge length on the second metatarsal, the mean depth was 22.5 mm ± 2.2, and was 26.7 mm ± 3.8 proximal on the intermediate cuneiform. For the 20 mm bridge length on the second metatarsal, the mean depth was 22.3 mm ± 2.2 and was 27.2 mm ± 2.0 proximal on the intermediate cuneiform. For the 15 mm bridge length for the third metatarsal mean depth was 21.5 mm ± 3.2, and was 24.2 mm ± 2.9 proximal on the lateral cuneiform. For the 20 mm bridge length on the third metatarsal, the mean depth was 20.3 mm ± 2.4 and was 24.6 mm ± 2.4 proximal on the lateral cuneiform. A student's two tailed homoscedastic t-Test was calculated for the 7.5 mm vs 10 mm distal and proximal distances for both second and third TMT data sets and found there was no significant differences in depth.The current study found that for both 15 mm and 20mm bridge lengths for 2nd TMT fusions a 22 mm leg length can be used appropriate and similarly for 3rd TMT fusions, a 20 m leg length appears to be appropriate fixation. Although variations will exist, advances towards indication specific fixation may allow for varied leg length for optimal boney purchase

Surgical planning for staple fixation of the first tarsometatarsal joint: An anatomic study

First tarsometatarsal (TMT) arthrodesis is a common procedure utilized by foot and ankle surgeons for the management of a variety of first TMT pathology including hallux valgus and arthritis. The present study was undertaken to determine the average staple leg depth that allows for adequate purchase within the medial cuneiform and first metatarsal base at 2 different staple bridge lengths for dorsal compression across the 1st TMT joint. A cadaveric study was performed using 20 fresh-frozen below knee specimens. After TMT dissection was performed, drill holes were then created from dorsal to plantar and parallel to the first TMT joint at the distances utilized for 20 mm and 25 mm staple bridge lengths. The depths of each drill hole were measured and recorded. The mean medial cuneiform depth corresponding to a 20 mm and 25 mm staple bridge was 31.9 mm +/- 2.8 mm and 31.1 mm +/- 2.1 mm respectively (P-value = 0.38). The mean first metatarsal depth corresponding to a 20 mm and 25 mm staple bridge was 27.9 mm +/- 2.2 mm and 25.4 mm +/- 3.4 mm respectively (P-value = 0.04), showing statistical significance. Based on our anatomic data it is suggested that a 20 mm staple leg depth is consistently a safe depth when using 20×20 and 25×20 mm dorsal compression staples. However, further studies must be conducted to compare the amount of compression between the two respective staples