First Metatarsophalangeal Joint Arthrodesis With Complete Resection of the Subchondral Bone Plate.

First metatarsophalangeal arthrodesis is associated with high union rates but there is a wide range of union incidence reported. Whether the subchondral plate is completely resected, is not reported by individual studies and without meticulous care, there is often residual subchondral plate. The primary aim was to report our union rate following first metatarsophalangeal arthrodesis with complete resection of the subchondral plate, locking plate fixation and immediate protected weight bearing. A retrospective case study of 2 surgeons was performed from August 2016 to June 2023. Our study was unique in that all patients had complete resection of the subchondral plate to trabecular bone. One hundred seventeen feet were identified for analysis, in 112 patients following exclusion criteria. Patients were excluded if they had less than 3 months follow-up, revisional surgery or charcot. Demographic data and indications for the procedure were reported. A single construct locking plate with an interfragmentary compression screw through the plate was used in 37 feet and a locking plate with separate interfragmentary compression screw was used in 80 feet. We reported a nonunion incidence of 0.9% (n = 1) with a delayed union incidence of 0.9% (n = 1) and a broken hardware incidence of 0.9% (n = 1). Complete resection of subchondral plate with early weight bearing and locking plate fixation had a high union rate for first metatarsophalangeal arthrodesis. Our results compare favorably with union rates in the literature, where there is often residual subchondral plate.

A Prospective Evaluation of First Metatarsophalangeal Fusion Using an Innovative Dorsal Compression Plating System.

Numerous techniques have been described for first metatarsophalangeal joint (MTPJ) fusion. The aim of this study was to prospectively evaluate an innovative plating system which uses a cross plate compression screw. Thirty consecutive first MTPJ fusions in 28 patients were evaluated. All procedures were performed by a single fellowship trained consultant foot and ankle surgeon. Patient function was evaluated preoperatively at 6 and at 12 months using the Manchester-Oxford Foot Questionnaire (MOXFQ). Union rates and complications were recorded. Postoperative MOXFQ scores demonstrated significant improvement in all domains, with mean improvement at 12 months of 35, 27, 17 and 106 points for pain, walking/standing, social interactions and combined scores respectively (p value ≤.0001). In all 30 cases, clinical and radiological evidence of union was achieved by 6 months. Superficial infection occurred in 1 (3%) case. One (3%) case required plate removal due to soft tissue irritation. There were no plate failures. This evaluation study demonstrates that this cross-plate compression plating system is safe, provides high patient satisfaction and reliable union, with low complication rates. Prospective comparative research is now required to determine the optimal technique for first MTPJ fusion.

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.

Body Mass Index, Sex, and Age Are Predictors of Discharge to a Post-acute Care Facility Following Total Ankle Arthroplasty.

BACKGROUND: The utilization of total ankle arthroplasty (TAA) continues to increase. Discharge to a post-acute care (PAC) facility can increase patient morbidity and postoperative costs. The purpose of this study is to investigate the effects of age and body mass index (BMI) on discharge to a PAC facility and hospital length of stay (LOS) following TAA. METHODS: A retrospective review of patients who underwent TAA from the National Surgical Quality Improvement Program (NSQIP) database was performed. Using overweight patients as the reference BMI group, sex- and age-adjusted log-binomial regression models were utilized to estimate risk ratios of BMI categories for being discharged to a PAC facility. A linear regression was utilized to estimate the effect of BMI category on hospital LOS. RESULTS: Obese patients had 1.36 times the risk of overweight patients (P = .040), and morbidly obese patients had 2 times risk of overweight patients (P = .001) of being discharged to a PAC facility after TAA. Men had 0.48 times the risk of women (P < .001). Compared with patients aged 18 to 44 years, patients aged ≥65 years had 4.13 times the risk (P = .012) of being discharged to a PAC facility after TAA. Relative to overweight patients, on average there was no difference in hospital LOS for underweight patients, but healthy weight patients stayed an additional 0.30 days (P=.003), obese patients stayed an additional 0.18 days (P = .011), and morbidly obese patients stayed an additional 0.33 days (P = .009). Men stayed 0.29 fewer hospital days than women (P < .001) on average. CONCLUSION: Women and patients who are obese or morbidly obese have a longer hospital LOS and an increased chance of being discharged to a PAC facility. Increasing age is also associated with an increased risk of being discharged to a PAC. These may be important factors when developing and discussing the postoperative plan with patients prior to TAA. LEVELS OF EVIDENCE: Level III.

Preliminary Experience With Commercially Available Trabecular Metal Tibial Cones Combined With a Retrograde Locked Intramedullary Nail for Bony Defects in Tibiotalocalcaneal Arthrodesis.

Critical sized bone defects in the ankle are becoming increasingly more common in patients undergoing limb reconstruction with tibiotalocalcaneal arthrodesis. Bulk allografts have not fared well over time. There have been scattered preliminary reports using custom spinal cages or 3D-printed Titanium Implants to address the critical bony defect; however, the cost of these devices is prohibitive in many clinical practice settings. The purpose of this investigation is to report the preliminary experience using a commercially available Trabecular Metal (Zimmer-Biomet) tibial metaphyseal cone combined with a retrograde locked intramedullary nail to address this challenging problem. Eight consecutive patients underwent tibiotalocalcaneal arthrodesis using a commercially available Trabecular Metal tibial metaphyseal cone combined with a retrograde locked intramedullary nail. Five developed bone loss secondary to neuropathic (Charcot) bony resorption and 3 underwent surgery for failed total ankle arthroplasty. All 8 patients eventually achieved clinical and radiographic healing and were able to ambulate with standard footwear. One patient developed a postoperative wound infection at the site of calcaneal locking screws, which resolved with debridement and parenteral antibiotic therapy. Critical bone defects about the ankle have successfully addressed with custom 3D titanium implants. This small series suggests that similar clinical outcomes can be achieved with the use of a commercially available porous tantalum metaphyseal spacer borrowed from our arthroplasty colleagues, combined with the use of a retrograde locked intramedullary nail.Levels of Evidence: Level 4: Retrospective case series.

Revision Total Ankle Arthroplasty Using a Novel Modular Fixed-Bearing Revision Ankle System.

INTRODUCTION: Large bone defects such as those encountered after failed total ankle replacement have previously been a relative contraindication to revision ankle replacement due to inadequate bone stock. We describe our experience and patient reported outcomes with a modular ankle replacement system with tibial and talar augments. METHODS: This is a retrospective case series analysis of patients who underwent a total ankle replacement using the INVISION system across 2 centers between 2016 and 2022. Patients completed the Manchester-Oxford Foot Questionnaire (MOXFQ), Ankle Osteoarthritis Scale (AOS), and EQ-5D pre-operatively and then post-operatively at 6 months, 1 year, 2 years, 3 years, and 5 years. Medical records were reviewed for complications and re-operations. X-rays were reviewed for lucencies and alignment. RESULTS: A total of 17 patients were included in the study; 14 men and 3 women with an average age at the time of surgery of 67.9 years (range 56-80 years). The average follow-up post-operatively was 40.5 months (range 7-78) at the time of this study. The indication for surgery was revision of failed total ankle replacement (TAR) in 16 and revision of failed ankle fusion in 1. An augmented tibia was used in 13, an augmented talus in 13, and both augmented tibia and talus in 9 cases. There were no early surgical complications. One patient required debridement and implant retention for late deep infection. No implants have been revised. The average MOXFQ score improved by 19.3 points at most recent follow-up. The average AOS score improved by 25.2 points. CONCLUSION: The early results of a modular augmented ankle arthroplasty system have shown satisfactory patient outcomes with a low complication and re-operation rate and present another option for patients with larger bone defects. This is a small series, and a larger series with long-term follow-up would be beneficial. LEVELS OF EVIDENCE: Level IV: Case series.

Rate of Infection and Causative Organisms in a Lateral Approach Total Ankle Replacement.

BACKGROUND: Although the rate of both superficial and deep infection in total ankle replacement (TAR) can reach up to 13% as reported in the literature, there is little information on the causative organisms, especially in laterally implanted prosthesis. This study aims to identify organisms causing infections to ultimately guide to better antibiotic prophylaxis. METHODS: Between September 2016 and April 2021, we retrospectively reviewed patients who had an infection after a lateral TAR. Cause of the infection, causative organisms, and implant survival were recorded. RESULTS: Out of 130 patients, 10 of 130 patients (7.6%) had a superficial infection whereas 3 of 130 patients (2.3%) had a deep infection. Staphylococcus and Pseudomonas species were found to be the most common. No significant difference was found between the type of plate used for fibula fixation regarding wound dehiscence. CONCLUSIONS: Infection after lateral TAR is generally polymicrobial in nature with Staphylococcus and Pseudomonas species being the most common. LEVEL OF EVIDENCE: Level IV Case Series.

Interposition Arthroplasty in the Treatment of End-Stage Hallux Rigidus: A Systematic Review.

PURPOSE: Patients affected by moderate to severe hallux rigidus may opt for interposition arthroplasty to avoid the movement restrictions of arthrodesis and the complications related to prosthetic replacement. The propose of this article was to review the current literature about interposition arthroplasty to examine the overall outcomes and to evaluate the advantages and disadvantages of different types of technique, compared with more consolidated procedures. METHODS: A literature PubMed search was performed. Studies reporting the results of interposition arthroplasty in moderate to severe hallux rigidus were included. The data were pooled and weighted for number of patients in every study. RESULTS: The overall results for interposition arthroplasties are comparable to other alternatives for end-stage hallux rigidus, providing better plantar load distribution than arthrodesis and avoiding the drawbacks of prosthetic replacement. Among the various interposition arthroplasty techniques, the Modified Oblique Keller Capsular Interposition Arthroplasty technique preserves toe length and flexor hallucis brevis function, showing the highest satisfaction rate, with lowest metatarsalgia and revision rate. CONCLUSION: Although long-term randomized controlled trials are lacking for interposition arthroplasty, it represents a valid alternative for the treatment of end-stage hallux rigidus also in the young active patient who wants to avoid a definitive intervention immediately. LEVEL OF EVIDENCE: III (systematic review of level III-IV-V studies).

Accuracy of CT-Derived Patient-Specific Instrumentation for Total Ankle Arthroplasty: The Impact of the Severity of Preoperative Varus Ankle Deformity.

BACKGROUND: Significant preoperative varus tibiotalar deformity was once believed to be a contraindication for total ankle arthroplasty (TAA). Our primary goal was to evaluate the influence of increasing preoperative varus tibiotalar deformity on the accuracy of final implant positioning using computed tomography (CT)-derived patient-specific guides for TAA. METHODS: Thirty-two patients with varus ankle arthritis underwent TAA using CT-derived patient-specific guides. Patients were subcategorized into varying degrees of deformity based on preoperative tibiotalar angles (0°-5° neutral, 6°-10° mild, 11°-15° moderate, and >15° severe). Postoperative weightbearing radiographs were used to measure coronal plane alignment of the tibial implant relative to the target axis determined by the preoperative CT template. Average follow-up at the time of data collection was 36.8 months. RESULTS: Average preoperative varus deformity was 6.06° (range: 0.66°-16.3°). Postoperatively, 96.9% (30/31) of patients demonstrated neutral implant alignment. Average postoperative tibial implant deviation was 1.54° (range: 0.17°-5.7°). Average coronal deviation relative to the target axis was 1.61° for the neutral group, 1.78° for the mild group, 0.94° for the moderate group, and 1.41° for the severe group (P = .256). Preoperative plans predicted 100% of tibial and talar implant sizes correctly within 1 size of actual implant size. Conclusion. Our study supports the claim that neutral postoperative TAA alignment can be obtained using CT-derived patient-specific instrumentation (PSI). Furthermore, final implant alignment accuracy with PSI does not appear to be impacted by worsening preoperative varus deformity. All but one patient (96.9%) achieved neutral postoperative alignment relative to the predicted target axis. LEVEL OF EVIDENCE: Level IV, Clinical Case Series.

Short-Term Complications Following Total Ankle Arthroplasty and Associated Risk Factors: A NSQIP Database Analysis.

INTRODUCTION: Total ankle arthroplasty (TAA) has become increasingly utilized over the past 20 years to treat osteoarthritis of the ankle. The efficacy and safety of this procedure has been previously reported, but relatively few studies have documented the risk of postoperative complications associated with TAA over the past 10 years. Thus, the aim of this study is to provide a current report on the safety of TAA, particularly in association with a number of preoperative risk factors. METHODS: A retrospective review of all patients in the American College of Surgeons National Surgical Quality Improvement Program database who underwent TAA between 2012 and 2018 was performed. A total of 1333 patients were included in this analysis. Penalized logistic regression to consider small numbers of the postoperative complications was used to identify factors associated with incidence of the complications. RESULTS: The rate of readmission and superficial wound infection were found to be 1.4% and 0.6%, respectively. Risk factors associated with a prolonged hospital stay were black race, Hispanic race, and smoking. Diabetes was associated with a significantly increased risk of readmission. Age, sex, body mass index, and steroid use were not associated with increased risk of postoperative complications. CONCLUSION: In this study, the rate of surgical site infection and readmission in TAA was found to be relatively low, compared to published data on total knee arthroplasty and total hip arthroplasty. Both race and smoking increase the risk of prolonged hospital stay, while diabetes increases the risk of readmission. LEVELS OF EVIDENCE: Level III, retrospective comparative trial.

Outcomes Following Repeat Ankle Arthroscopy and Microfracture for Osteochondral Lesions of the Talus.

BACKGROUND: The management of symptomatic osteochondral lesions of the talus (OLTs) previously treated with arthroscopy is controversial. Minimal data exist on the role for repeat arthroscopy. Here, we describe our experience with repeat arthroscopy and microfracture for symptomatic OLTs. METHODS: Our database was queried over an 8-year period to identify patients undergoing repeat arthroscopy and microfracture as treatment for symptomatic OLTs. Phone surveys were conducted to assess residual pain, patient satisfaction, and need for subsequent surgery. We compared patient outcomes based on the size of their OLT (small lesions ≤150 mm2, large >150 mm2) and the presence or absence of subchondral cysts. RESULTS: We identified 14 patients who underwent repeat arthroscopy and microfracture for symptomatic OLTs. Patients reported reasonable satisfaction (7.6 ± 3.5 out of 10) but moderate residual pain (4.7 ± 3.4 out of 10) at midterm follow-up (5.1 ± 2.9 years). In total, 21% (3/14) of patients had undergone subsequent surgery. Patients with small (n = 5) and large OLTs (n = 9) had similar postoperative pain scores (4.2 ± 4.1 vs 4.9 ± 3.2) and postoperative satisfaction levels (6.4 ± 4.9 vs 8.3 ± 2.5). CONCLUSION: At midterm follow-up, repeat arthroscopy for symptomatic OLTs demonstrated reasonable satisfaction but moderate residual pain. Lesion size or presence of subchondral cysts did not affect outcome, but our sample size was likely too small to detect statistically significant differences. These data show that repeat ankle arthroscopy can be performed safely with modest outcomes, and we hope that this report aids in managing patient expectations.Level of Evidence: Level IV Case Series.

Total Ankle Arthroplasty Survivorship, Complication, and Revision Rates in Patients Younger Than 55 Years.

Total ankle replacement has become a viable alternative to ankle arthrodesis in the surgical management of advanced ankle arthritis. Total ankle replacement has generally been reserved for patients who are older and for those who will have a lower demand on the replacement. The purpose of the current study is to review patient outcomes, complications, and implant survival in patients younger than 55 years who underwent total ankle replacement at a single institution. A single-center chart and radiographic review was performed of consecutive patients who underwent total ankle replacement for treatment of end-stage ankle arthritis. All surgeries were performed by 1 of 5 fellowship-trained foot and ankle surgeons at a single institution. A total of 51 patients met inclusion criteria with a mean follow-up of 31.2 months (SD = 16.2). Implant survival was 94%, There were 7 major complications (13%) requiring an unplanned return to the operating room and 8 minor complications (15%) that resolved with conservative care. The results of this study show that total ankle replacement is a viable treatment option for patients younger than 55 years.Levels of Evidence: A retrospective case series.

Avascular Necrosis of the Talus Following Subchondroplasty: A Case Report and Review of Literature.

CASE: Avascular necrosis (AVN) of the talus in a 45-year-old female following subchondroplasty with calcium phosphate bone filler for treatment of anterolateral and posteromedial talar dome bone marrow lesions (BMLs). The patient subsequently presented as consultation, 18 months postoperatively, with AVN of the talus. After failing conservative management, the patient underwent a total ankle arthroplasty at 46 months after subchondroplasty with resolution of pain. CONCLUSION: There are few studies that have reported on the safety of subchondroplasty of the talus. Given the tenuous blood supply to the talar body and poor patient outcomes associated with AVN, caution should be taken before extrapolating the generally positive results of subchondroplasty in the knee. LEVEL OF EVIDENCE: Level IV.

Subtalar joint preparation using the Two Portal posterior arthroscopic technique versus the sinus tarsi Open approach: A cadaver study.

BACKGROUND: Subtalar fusion is the treatment of choice for subtalar arthritis when conservative management fails. The procedure can be performed arthroscopically or through the open lateral sinus tarsi (LST) approach. The arthroscopic technique is less invasive and is associated with rapid recovery, but it is more technically challenging. One of the most important aspects of fusion is adequate preparation of the joint via denudation of articular cartilage. This study compares the efficacy of subtalar joint preparation between the lateral sinus tarsi approach and the posterior two-portal arthroscopic technique using cadaveric specimens. MATERIALS AND METHODS: Nineteen below-knee fresh-frozen cadaver specimens were used. The subtalar joints of nine specimens were prepared through the LST approach, while ten were prepared arthroscopically. After preparation, all ankles were dissected at the subtalar joint and photographs were taken of the posterior facets of the calcaneus and talus. Total and prepared surface areas of the articular surfaces for both approaches were measured using ImageJ software and compared. RESULTS: The LST technique resulted in significantly greater percent preparation of the posterior facet of the calcaneus, as well as of the subtalar joint as a whole. Overall, 92.3% of the subtalar joint surfaces (talus and calcaneus combined) were prepared using the LST technique, compared to 80.4% using the arthroscopic technique (p = 0.010). The posterior facet of the calcaneus was 94.0% prepared using the open technique, while only 78.6% prepared using the arthroscopic technique (p = 0.005). CONCLUSION: The LST approach for subtalar arthrodesis provides superior articular preparation compared to the two-portal posterior arthroscopic technique. Given that joint preparation is a critical component of fusion, maximizing prepared surface area is desirable and the open approach may be more efficacious for fusion. When using the arthroscopic approach, it may be advisable to use an accessory portal if there is poor visualization or limited access to the joint space secondary to severe arthritis. LEVEL OF EVIDENCE: V.

From Patient to Procedure: The Process of Creating a Custom 3D-Printed Medical Device for Foot and Ankle Pathology.

Three-dimensional (3D) printing technology has advanced greatly over the past decade and is being used extensively throughout the field of medicine. Several orthopaedic surgery specialties have demonstrated that 3D printing technology can improve patient care and physician education. Foot and ankle pathology can be complex as the 3D anatomy can be challenging to appreciate. Deformity can occur in several planes simultaneously and bone defects either from previous surgery or trauma can further complicate surgical correction. Three-dimensional printing technology provides an avenue to tackle the challenges associated with complex foot and ankle pathology. A basic understanding of how these implants are designed and made is important for surgeons as this technology is becoming more widespread and the clinical applications continue to grow within foot and ankle surgery.Levels of Evidence: Level V.

Consumer Prices for Surgical Management of End-Stage Hallux Rigidus.

Background. Hallux rigidus is the most prevalent arthritic condition of the foot. Treatment of end-stage disease traditionally consists of a first metatarsophalangeal joint (MTPJ) arthrodesis; however, the use of a synthetic cartilage implant is becoming more common. With the high prevalence of disease and implementation of new treatment modalities, health care consumers should be aware of the costs associated with management. The purpose of this study was to determine access to the cost and variability in price of first MTPJ arthrodesis and synthetic cartilage implantation. Methods. Forty academic centers were contacted using a standardized patient script. The patient was a 59-year-old female who had failed conservative treatment of hallux rigidus. Each institution was contacted up to 3 times in an attempt to obtain a full bundled operative quote for a first MTPJ arthrodesis and synthetic cartilage implantation. Results. Twenty centers (50%) provided a quote for first MTPJ arthrodesis and 15 centers (38%) provided a quote for synthetic cartilage implantation. Only 14 centers (35%) were able to provide a quote for both procedures. The mean bundled price for MTPJ arthrodesis was $21 767 (range $8417 to $39 265). The mean bundled price for synthetic cartilage implantation was $21 546 (range $4903 to $74 145). There was no statistically significant difference between the bundled price for first MTPJ arthrodesis and synthetic cartilage implantation. Conclusions. There was limited availability of consumer prices for first MTPJ arthrodesis and synthetic implantation, thus impeding health care consumers' decision making. There was a wide range of quotes for both procedures, indicating potential cost savings.Levels of Evidence: IV, basic science.

Early Outcomes of 3D Printed Total Talus Arthroplasty.

BACKGROUND: Patients with talar avascular necrosis (AVN) have limited treatment options to manage their symptoms. Historically, surgical options have been limited and can leave patients with little ankle motion and have high failure rates. The use of custom 3D printed total talar replacements (TTRs) has arisen as a treatment option for these patients, possibly allowing better preservation of hindfoot motion. We hypothesized that patients undergoing TTR will demonstrate a statistically significant improvement in Foot and Ankle Outcome Score (FAOS) at 1 year after surgery. METHODS: We retrospectively reviewed 15 patients who underwent a TTR over a 2-year period. Patient outcomes were reviewed, including age, sex, comorbidities, etiology of talar pathology, number and type of prior surgeries, radiographic alignment, FAOS and Visual Analog Scale (VAS) score, and range of motion. Data analysis was performed with Student t-tests and multivariate regression. RESULTS: FAOSs and VAS scores showed statistically significant improvements postoperatively as compared with preoperative scores. There was a statistically significant decrease in VAS pain scores from 7.0 preoperatively to 3.6 (P < .001). Average follow-up was 12.8 months. With the number of patients available, there was no statistically significant change in radiographic alignment parameters postoperatively as compared with preoperatively (P values ranged from .225 to .617). CONCLUSION: Our hypothesis that these patients show statistically significant improvements in FAOSs at 1 year was confirmed. TTR represents an exciting treatment option for patients with talar AVN, though longer-term follow-up is needed.Level of Evidence: Level IV: Case series.

Subtalar Fusion Preparation: What Are We Really Doing? A Cadaver Study.

Introduction. The open, lateral sinus tarsi approach is the most commonly used technique for subtalar arthrodesis. In this cadaver study, we measured the maximum joint surface area that could be denuded of cartilage and subchondral bone through this approach. Methods. Nine fresh frozen above-knee specimens were used. The subtalar joint was accessed through a lateral incision from the fibular malleolus distally over the sinus tarsi area to the level of the calcaneocuboid joint. Cartilage was removed from the anterior, middle, and posterior facets of the calcaneus and talus using an osteotome and/or curette. ImageJ was used to calculate the surface areas of undenuded cartilage. Results. No specimens were 100% denuded of cartilage on all 6 measured surfaces. The greatest percentages of unprepared surface area remained on the middle facet of the talus (18.66%) and the middle facet of the calcaneus (14.51%). The anterior facet of the talus was 100% denuded in 6 specimens, while the middle and posterior facets were 100% denuded in 3 specimens. The anterior facet of the calcaneus was also 100% denuded in 6 specimens, while the middle and posterior facets were 100% denuded in 3 and 4 specimens, respectively. The average total unprepared surface area per specimen was 8.67%. Conclusion. The lateral sinus tarsi approach provides adequate denudation of cartilage of the subtalar joint in most cases. Total percentage of unprepared joint surface may range from approximately 2% to 18%. Future clinical studies are warranted to assess whether this technique results in optimal union rates. Levels of Evidence:V, Cadaveric Study.

Subchondroplasty of the Ankle and Hindfoot for Treatment of Osteochondral Lesions and Stress Fractures: Initial Imaging Experience.

Objective:To describe the imaging findings of patients treated with subchondroplasty (SCP) of the ankle and hindfoot. Materials and Methods: Eighteen patients (10 men, 8 women; age mean 43.1 years [range 20.1-67.7 years]) underwent ankle and hindfoot SCP at a single center over a 14-month period. Imaging data were reviewed retrospectively by 2 radiologists by consensus interpretation, including preoperative radiography (18), computed tomography (CT) (11), and magnetic resonance imaging (MRI) (13) and postoperative radiography (10), CT (4), and MRI (6). Follow-up imaging was acquired 1 month to 1.6 years following SCP. Results: Indications for SCP included symptomatic bone marrow lesions (BMLs) secondary to an osteochondral lesion (OCL) (16/18) or stress fracture (2/18). While focal radiodensity related to the SCP procedure was retrospectively identifiable on postoperative radiography in all except 1 case (10/11), postprocedural findings were not described by the interpreting radiologist in 6/11 cases. On CT, the average injected synthetic calcium phosphate (CaP) volume was 1.15 cm3 (SD = 0.33 cm3); mean CT attenuation of the injectate was 1220 HU (range 1058-1465 HU). In all patients who had pre- and postoperative MRI (5/18), BML size decreased on follow-up MRI. Extra-osseous extrusion of CaP was not seen on postoperative radiography, CT, or MRI. Conclusion: Physicians should be aware of the expanding preoperative indications and postoperative imaging findings of SCP, which is being performed with increasing frequency in the ankle and hindfoot.Levels of Evidence: Diagnostic, Level III: Retrospective cohort study.

The Infinity Total Ankle System: Early Clinical Results With 2- to 4-Year Follow-up.

AIMS: This study presents the first report of clinical and radiographic outcomes of the Infinity Total Ankle System (Wright Medical, Memphis, TN) with minimum 2-year follow-up. PATIENTS AND METHODS: The first 67 consecutive patients who underwent primary total ankle arthroplasty (TAA) with the Infinity system at 2 North American sites between August 2013 and May 2015 were reviewed in a prospective, observational study. Demographic, radiographic, and functional outcome data were collected preoperatively, at 6 to 12 months postoperatively, and annually thereafter. RESULTS: The overall implant survival rate was 97% (65 of 67 implants) at a mean follow-up of 35.4 months (27 to 47 months). Two cases underwent talar component revision for aseptic loosening. Six of the 67 cases (9%) required a nonrevision reoperation. Mean Foot Function Index and Ankle Osteoarthritis Scale scores at latest follow-up improved from preoperative by 21.6 ( P < .0001) and 34.0 ( P < .0001), respectively. No radiographic loosening of any talar or tibial components was identified in the 65 nonrevised cases. CONCLUSION: Early clinical and radiographic outcomes with the Infinity TAA are promising and compare favorably to those reported for both fixed- and mobile-bearing third-generation TAA designs, even when used in cases with deformity and increased case complexity. LEVELS OF EVIDENCE: Level IV.