Rate of Development of Hallucal Interphalangeal Degenerative Joint Disease After First Metatarsophalangeal Joint Arthrodesis

Category: Midfoot/Forefoot Introduction/Purpose: The first metatarsophalangeal joint (MTPJ) is an integral part of the foot during the gait cycle. Arthrodesis of this joint is gold standard, especially in patients with rheumatoid arthritis. The development of IPJ arthritis after an arthrodesis of the MTPJ has been established in the literature; however, the significance of this has not. The purpose of this study was to determine the rate of IPJ degenerative joint disease (DJD) in patients who underwent first MTPJ fusion by evaluating the degree of IPJ arthritic degeneration through 2 years post-surgery and to compare radiographic parameters over time among patients with and without DJD in order to determine whether non-fusion (less than 50% fusion) or the hallucal position was associated with the subsequent development of DJD. Methods: Retrospective clinical and radiographic review of patients who had undergone a first metatarsophalangeal joint arthrodesis was performed. Inclusion criteria were adult patients 18 and older who underwent first MPJ arthrodesis between January 2012 and January 2015 with internal fixation of any type. Patients were excluded if they were under 18 years of age, underwent concomitant procedures that would affect postoperative weight bearing course, suspected or diagnosed with osteomyelitis of the foot, had prior surgical procedures of the MTPJ or IPJ joints, or concomitant hallucal IPJ arthritis or preexisting IPJ fusion. Postoperative radiographs were obtained immediately following surgery and at approximately 6 weeks, 3 months, 6 months, 12 months, and 24 months. Results: Ultimately, 103 patients met all the inclusion criteria and none of the exclusion criteria. Four of the 103 patients (3.9%) had undergone bilateral procedures, thus providing 107 surgical procedures. Demographic characteristics can be found on Table 1. The hallux abductus (HA) angle and hallux abductus interphalangeus (HAI) angle were measured preoperatively and postoperatively (Fig. 1-2). The average postoperative follow-up radiograph was taken at 22.9 weeks. The HA angle average preoperatively was 31.4 degrees, which decreased to 11.8 degrees postoperatively. The HAI angle average preoperatively measured 10.8 degrees and increased to 11.9 degrees postoperatively. No patients had symptomatic hallux IPJ postoperatively within the study period. However, 7 patients needed hardware removal and second surgery at an average of 36.3 weeks due to hardware pain and nonunion. Conclusion: Arthrodesis is often the treatment of choice for first MTPJ pathology, which is commonly arthritis or hallux valgus. We found the incidence of IPJ arthritis to be lower than the reported literature and unchanged over the postoperative period. Furthermore, no patients reported symptomatic hallux IPJ within the study period. Also, we found the HA angle had decreased in the patients postoperatively; however, there was a mixed trend with HAI increasing after first MTPJ fusion. The significance of this trend is unclear, but the increase of the HAI could possibly cause further pain and deterioration of the joint in the future

Anatomic Description of the Anterior Body Calcaneal Z-Osteotomy

Category: Ankle Introduction/Purpose: Flexible pes planovalgus is a common condition encountered by foot and ankle physicians. Many treatment options exist to correct this deformity. One such procedure is an Evans osteotomy of the anterior process of the calcaneus. Due to the complications seen with this type of osteotomy, there has been an attempt to reduce these complications and as a result, an anterior body calcaneal z-cut osteotomy was developed. This osteotomy is inherently more stable by design and fewer complications have been reported. In an attempt to further understand this osteotomy and to determine how much bony interface remained following this osteotomy, a cadaveric study was performed. Methods: A Z-cut osteotomy was performed on 10 cadaveric specimens with the distal arm exiting dorsal and 1 cm proximal to the calcaneocuboid joint, while the proximal arm exited plantarly. The central axis lengths of 15 mm and 20 mm were compared. An 8-mm wedge was placed in both the distal and proximal arms, and fixated with a staple. Digital calipers were used to measure the amount of bony apposition on the central arm between the wedges. Results: The average amount of bone apposition was 9.13 mm. When comparing the 20 mm to 15 mm central arm groups, the average bony apposition was 10.66 mm and 7.61 mm, respectively. Conclusion: Based on these results, the anterior body calcaneal Z-osteotomy provides enough bony apposition between both groups with an 8-mm wedge distraction. Further studies are warranted to evaluate the union rate between the classic lateral column lengthening osteotomy and the anterior body calcaneal Z-osteotomy

Structures at Risk with Plantar Approach Retrograde First Metatarsal Charcot Beam Screw Insertion

Category: Diabetes, Midfoot/Forefoot Introduction/Purpose: The plantar approach for medial column retrograde intramedullary fixation of Charcot midfoot deformity allows for easy access to the ideal starting point on the metatarsal head and is supported by good clinical outcomes data. The primary argument against this approach is iatrogenic damage to the plantar structures of the metatarsophalangeal joint (MTP), which could cause tendon imbalances resulting in hallux malleus deformity. However, thus far, such complications have rarely been reported. Based on available literature, it is unclear what types of plantar structure injury occur and at what frequency. The purpose of this study was to describe plantar first metatarsophalangeal joint structure damage caused by plantar approach retrograde intramedullary medial column beam fixation. Methods: This was an IRB-exempt study. For each of 10 human cadaveric specimens, a 6.5 mm cannulated screw system was used for plantar approach retrograde medial column intramedullary fixation. This entailed using fluoroscopy to percutaneously localize a 2.8-millimeter (mm) guide wire to the center-center position on the first metatarsal head and then advanced it into the center of the medial cuneiform. A small sagittal plane skin incision was made around the wire and subcuticular tissue was bluntly divided. Next, a 4.8-mm cannulated drill was passed through a drill sleeve over the wire. Then, a countersink was used without a tissue protector. Finally, the 6.5-mm screw was inserted until it was recessed beneath subchondral bone. The specimens were then dissected to evaluate damage to the plantar structures of the 1st MTP joint. Damage to named structures was categorized as none, less than 50%, greater than 50%, and 100%. Results: The plantar plate was less than 50% damaged in all specimens. The flexor hallucis longus (FHL) tendon had less than 50% damage in 8 specimens. In one of two specimens with greater than 50% FHL damage, the torn portion of the tendon was tenodesed to the first metatarsal head by the screw (Figure). Although the medial flexor hallucis brevis (FHB) tendon was less than 50% damaged in 3 specimens and undamaged in the remainder, the medial sesamoid was less than 50% damaged in 8 specimens. In contrast, less than 50% damage occurred to the lateral FHB and lateral sesamoid in only 2 and 3 specimens, respectively. Additionally, some erosion of the plantar base of the proximal phalanx was observed in one specimen. Conclusion: The plantar structures of the hallux MTP are a tightly constrained system, which are violated during plantar approach retrograde intramedullary medial column fixation. No structures were completely transected and high-grade damage (greater than 50%) was infrequent, occurring in only two FHL tendons. Low-grade damage (less than 50%) was frequently observed to involved the FHL, medial sesamoid, and plantar plate. Based on the current findings, an FHL splitting or preserving approach is advisable to avoid high-grade damage if plantar approach is desired. A dorsal arthrotomy approach avoiding plantar structures may also be considered

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

Structures at Risk from an Intermetatarsal Screw for Lapidus Bunionectomy

Category: Midfoot/Forefoot Introduction/Purpose: The Lapidus procedure is a common procedure for the treatment of hallux abducto valgus. Traditional fixation consists of two crossing screws in the sagittal plane. Despite arthrodesis of the first tarsometatarsal joint, recurrence of the hallux abducto valgus deformity remains a concern. A transverse screw spanning the base of the first metatarsal to the base of the second metatarsal has been advocated to provide transverse plane stability. However, the neurovascular bundle is located within the proximity of this screw. The literature is sparse with a standard technique to safely provide appropriate fixation. An anatomic cadaver study was undertaken to assess the risk of injury to the neurovascular bundle. Methods: Ten unmatched cadaveric limbs that had been disarticulated at the knee were used. Under fluoroscopic guidance, the guide wire to a 4.0-mm screw was driven across the base of the first metatarsal and into the second metatarsal. A 4.0-mm screw was inserted, taking care to obtain osseous purchase into the second metatarsal. A longitudinal incision was made and careful dissection was carried to identify the neurovascular bundle and screw. The neurovascular bundle was inspected for trauma and the proximity of the screws was measured using a digital caliper. Results: There were three left-sided and seven right-sided specimens. Five of the specimens were male and five were female. The mean age of the specimens at date of death was 71.4 years. The mean body mass index was 20.5. The mean distance from the 4.0-mm screw to the first metatarsal base 11.24 mm distal to the first tarsometatarsal joint. The deep plantar artery and deep peroneal nerve was free from injury in 10/10 (100%) specimens. However, the screw was measured to be less than 5 mm in three specimens. In these instances, the average distance of the screw distal to the first tarsometatarsal joint was 12.1 mm. Conclusion: The addition of the intermetatarsal screw for Lapidus bunionectomy is widely accepted clinical practice. Descriptions of the operative technique for the placement of hardware into the second metatarsal have not included specific recommendations to avoid potential risk to the neurovascular bundle as it courses between the bases of the first and second metatarsals. According to this cadaveric study, the neurovascular bundle was avoided with placement of the intermetatarsal screw, if placed approximately 11.24 mm distal to the first tarsometatarsal joint. Further study is warranted to evaluate the optimal distance distal to the first tarsometatarsal joint

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

Beaming in Charcot Arthropathy- Intramedullary Fixation for Complicated Reconstructions

Category: Midfoot/Forefoot Introduction/Purpose: In the modern treatment of Charcot neuroarthropathy, beam screw fixation is an attractive alternative to plate and screw fixation because it minimizes the required exposure for implantation and supports the longitudinal columns of the foot from the inside out as a rigid yet load-sharing construct. Oversized implants risk metatarsal fracture and undersized implants risk implant fracture or impaired healing from mechanical instability. Our review of the scientific literature identified a lack of evidence regarding the aspects of metatarsal intramedullary canal morphology relevant to beam screw fixation. The purpose of the present study was to qualitatively and quantitatively describe metatarsal diaphyseal morphology. Methods: Twenty fresh-frozen adult cadaveric below knee specimens were utilized to assess the size and shape of the diaphysis of metatarsals 1-4. There were 10 male and 10 female specimens with a mean age of 75.8 years. No limbs had outward signs of prior injury/surgery, radiographic signs of Charcot neuroarthropathy or previous fracture. Metatarsals 1-4 were excised, cleaned of all soft tissue and then axially transected at the point of most narrow external diameter. The diaphyseal canal shape was categorized as round, oval, triangular, or pear. The widest distance between two endosteal cortical surfaces was measured. Results: Triangular endosteal canals were only found in the 1st metatarsal whereas the remainder of metatarsals canals were largely round or oval. The mean diameter of the 1st metatarsal was 9.08 ± 1.26 mm. The mean diameter of the 2nd metatarsal was 4.72 ± 0.82 mm. The mean diameter of the 3rd metatarsal was 4.53 ± 0.88 mm. The mean diameter of the 4th metatarsal was 4.51 ± 1.10 mm. Conclusion: Intramedullary fixation by internal beaming of the columns of the foot can provide anatomical alignment with stabile fixation in cases of patients with Charcot arthropathy. Our study has given the smallest average diameter for metatarsals one through 4. This data is helpful when determining what size fixation to choose to achieve the maximum screw-endosteal purchase for column beaming in Charcot reconstructions

Intramedullary Screw Fixation and Relevant Diameter of the Proximal Phalanges of the Foot

Category: Midfoot/Forefoot Introduction/Purpose: The average intramedullary diameter of the proximal phalanges of the foot has not been well documented in the literature. This dimension has important implications for surgical fixation devices, such as intramedullary screws. By design, intramedullary fixation devices rely on endosteal fit to provide stability. The precise intramedullary diameter is not readily identifiable on plain radiographs. A better understanding of the average diameter of the proximal phalanges of the foot can assist surgeons in surgical planning and appropriate screw diameter selection to provide more satisfactory patient outcomes. Methods: Twenty below-knee cadaveric specimens were dissected to expose each proximal phalanx. A sagittal saw was used to transect the diaphysis at its narrowest portion. The dorsal to plantar and medial to lateral diameters were measured using a digital manometer. Results: The average diameter dorsal to plantar for each digit was 6.25 ± 2.24 mm, 3.61 ± 1.25 mm, 2.94 ± 0.70 mm, 2.72 ± 0.77 mm, and 2.48 ± 0.80 mm, respectively. The average diameter medial to lateral for each digit was 7.83 ± 2.13 mm, 3.08 ± 0.93 mm, 2.47 ± 0.74 mm, 2.33 ± 0.73 mm, and 2.62 ± 0.69 mm, respectively. The overall average diameter for toes one through five was 7.04 ± 1.95 mm, 3.35 ± 1.04 mm, 2.71 ± 0.66 mm, 2.52 ± 0.71 mm, and 2.55 ± 0.63 mm, respectively. Conclusion: Understanding the intramedullary diameters of the proximal phalanges of the foot is a valuable tool when utilizing intramedullary surgical stabilization. The hallux proximal phalanx demonstrated the largest, and most variable, diameter, which could make selection intramedullary fixation difficult. In addition, the hallux proximal phalanx may lend itself better to 2 smaller fixation devices rather than one larger one. The lesser phalanges demonstrated smaller diameters more consistently, which is more amenable to a single smaller (2.5 mm) intramedullary device. This data can provide surgeons with an expected intramedullary diameter during surgical planning

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