Comparison of Foot Center Axis and Ankle Rotation using Weight-Bearing CT

Category:

Ankle; Ankle Arthritis

Introduction/Purpose:

Even as its popularity increases, there remain many unanswered questions regarding total ankle arthroplasty. One debate considers how best to restore proper rotation of the talar component relative to native, non- osteoarthritic anatomy. At present, two common schools of thought are to parallel the talar component rotation with the medial gutter line or to choose a line that bisects the gutters. These axis' are then considered with respect to a chosen foot axis, often defined by the second metatarsal or second toe clinically. The present study sought to define the foot center axis relative to the ankle on weight-bearing CT in patients without ankle osteoarthritis to inform talar component positioning in total ankle arthroplasty.

Methods:

Following IRB approval, charts were reviewed to identify patients without ankle osteoarthritis, trauma or other deformity who received a weightbearing CT scan. A pilot group of n=34 patients were included for a total of n=50 limbs. Average age was 50.3 +/- 7 and there were = 54% female patients. All measurements were made on MPR (multiplanar reformation) axial reconstructions. Cobb angle measurements between the anatomic foot center, the second, the fourth metatarsal and the gutter bisector or medial gutter line were recorded. Statistical analysis was performed by IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY.

Results:

The mean gutter bisector angle was 5.7 deg +/- 2.0. The mean cobb angle between the anatomic foot center and the medial gutter line was 6.1 deg +/- 4.4 and between the anatomic foot center and gutter bisector was 6.3 deg +/- 4.8, there was no statistical difference between measurements (p=0.62, Table 1). The mean cobb angle between the second metatarsal and the gutter bisector was 9.9 deg +/- 6.8, whereas the mean cobb angle between the fourth metatarsal and the gutter bisector was 7.5 deg +/- 5.2, which was not statistically significant (p=0.053). There was no statistical difference between mean cobb angle measurements between the anatomic foot center and the gutter bisector and the fourth metatarsal and the gutter bisector (p=0.243), but there was statistical difference between mean cobb angle measurements of the second metatarsal and the gutter bisector and the anatomic foot center and the gutter bisector (p=0.003).

Conclusion:

The axial alignment of the foot center axis relative to the ankle in patients without deformity or osteoarthritis is most collinear with the medial gutter line. In general, the axial alignment of the ankle joint relative to the foot in patients without osteoarthritis tends towards <10 degrees of difference on weight-bearing CT, regardless of method chosen. Due to both the consistency of measure and reproducibility of measure on pre-operative weight-bearing CT, the anatomic foot center may be a useful guide for establishing intra-operative foot orientation when performing total ankle arthroplasty.

Outcomes Following Total Talus Replacement: A Systematic Review

Category:

Ankle; Hindfoot; Trauma

Introduction/Purpose:

Prosthetic substitution of the talus presents a unique challenge to the foot and ankle surgeon. The shear and compressive forces on the talus and its tenuous blood supply lead to high rates of avascular necrosis with possible talar collapse. The purpose of this systematic review is to evaluate whether total talus replacements (TTR) lead to improved clinical outcomes with appropriate safety metrics in patients with a history of avascular necrosis or significant trauma.

Methods:

Concepts of talus and arthroplasty were searched in MEDLINE (PubMed), Embase (Elsevier), CINAHL Complete (EBSCOhost), and Scopus (Elsevier) from the database's inception through November 4, 2021. Inclusion Criteria were 1) previous trauma to the talus, 2) post-traumatic or degenerative arthritis to the tibiotalar joint, 3) avascular necrosis of talus, 4) multiple failed prior interventions, 5) degenerative osteoarthritis to the tibiotalar joint, and 56) inflammatory arthropathy to tibiotalar joint. Manuscripts in non-English languages or those with concomitant total ankle arthroplasty or revision arthroplasty were excluded. All study designs were eligible according to the Journal of Bone and Joint Surgery criteria level I-IV. The modified Coleman Methodology Score was used to evaluate study quality and the Methodological Index for Non-Randomized Studies criteria was used to assess risk of bias.

Results:

Twenty-two studies of 191 patients (196 tali) at an average age of 50 (14-80) years were included (Figure 1a). Nineteen studies utilized third generation implants, two studies used first generation (n=9), and one study used second generation implants (n = 14) made of ceramic (n=82), cobalt chrome (n=49), or titanium (n=23) (Figure 1b). Radiographic and patient-reported outcomes are outlined in Figure 1c. The most common adverse outcome was osteosclerosis of the tibia (n=24), calcaneus (n=19), and navicular (n=5). Additionally, hindfoot varus (n=3), ankle discomfort (n = 3), decreased subtalar motion (n=7), periprosthetic fracture (n=1), calcaneal fracture (n=1), delayed wound healing (n=3), hindfoot valgus (n=1), prosthetic stem sunken into the talar neck (n=1), superficial peroneal nerve neuroma (n=1), loosening (n=2) were reported. Eight revisions were reported.

Conclusion:

TTR is an appealing option to maintain range of motion through the tibiotalar joint and allow for maintenance of more normal foot and ankle biomechanics. Given promising early- and mid-term outcomes, TTR is becoming more widely used in the setting of talar collapse. Still, high complication rates, especially adjacent joint osteoarthritis, may remain under-reported in the literature given inadequate long-term follow-up. Future research should aim to expand upon the indications of TTR, elucidate survivorship and complication rates, and directly compare TTR to existing forms of salvage options for advanced talar avascular necrosis.

The Role of the Plantar Fascia, Flexor Hallucis Longus, and Fiberosseous Tunnel in Functional Hallux Rigidus

Category:

Midfoot/Forefoot

Introduction/Purpose:

Functional hallux rigidus is characterized by limited first metatarsophalangeal (MTP) dorsiflexion during weight bearing conditions, but normal motion when the metatarsal is allowed to plantarflex. This phenomenon alters the mechanics of the foot, potentially leading to lateral column overloading and dynamic cavovarus. Furthermore, it is suspected that the abnormal forces across the first MTP alters its biomechanics, leading to cartilage destruction and eventual structural hallux rigidus. The purpose of this study is to assess the role of the flexor hallucis longus (FHL) and plantar fascia in functional hallux rigidus and to determine the best surgical treatment.

Methods:

Six cadaveric lower limbs disarticulated at the hip were analyzed. The feet were positioned manually in the same manner that would be used in a clinical exam of patients. The examiner's thumb was used to stabilize the first metatarsal head and prevent plantarflexion to simulate the closed-chain kinetics of weight bearing. The same hand was used to hold the ankle neutrally aligned to the leg. The other hand was used to maximally dorsiflex the great toe. X-ray was used to obtain images of the feet. The plantar fascia was transected with a Z cut, shortened approximately 5 mm, then repaired. The fiberosseous tunnel was released. The FHL was transected with a Z cut then shortened approximately 5 mm. Great toe dorsiflexion was assessed and X-rays taken after each of the manipulations. Range of motion of the first MTP was measured on Xrays and analyzed using Student's T-test.

Results:

Average passive dorsiflexion of the first MTP is 29.8° (range 17-46°) prior to manipulation. Shortening the plantar fascia and FHL did not decrease the MTP dorsiflexion significantly beyond baseline (P = 0.08, 0.09 respectively). Transecting the plantar fascia increased the dorsiflexion by 14° (standard deviation (SD) 9.5) and transecting the FHL increased dorsiflexion by 13.7° (SD 4.0). Dorsiflexion increased significantly beyond baseline with both these methods (P = 0.02 and P < 0.001 respectively), but the difference between the two methods was not significant (P = 0.93). Releasing the fiberosseous tunnel alone increased the dorsiflexion 8.8° (SD 5.7). Increased dorsiflexion beyond baseline was significant (P = 0.03). The increase in dorsiflexion with fiberosseous tunnel release was not significantly different than transecting the plantar fascia or the FHL (P = 0.40 and 0.42 respectively).

Conclusion:

By definition, functional hallux rigidus is diagnosed when first MTP dorsiflexion cannot reach 60°. Its prevalence may be more widespread than previously identified. Both the FHL and plantar fascia are implicated in functional hallux rigidus, as transection of either improves the dorsiflexion of the great toe. However, accessing the plantar fascia comes with significant risks and complete transection of the FHL is not feasible. As an alternative, releasing the fiberosseous tunnel is a simple, minimally morbid procedure that can also significantly improve functional hallux rigidus to a similar degree.

Validating Foot Center Axis and Ankle Rotation using Weight-Bearing CT

Category:

Ankle; Ankle Arthritis

Introduction/Purpose:

Even as its popularity increases, there remain many unanswered questions regarding total ankle arthroplasty. One debate considers the proper rotation of the talar component to restore native, non-osteoarthritic anatomy. The foot center axis is a unique anatomic concept that considers the position of the native foot relative to the ankle. The present pilot study sought to evaluate the reproducibility of axial alignment measurements, including the foot center on weight-bearing CT in patients without ankle osteoarthritis.

Methods:

Following IRB approval, charts were reviewed to identify patients without ankle osteoarthritis, trauma or other deformity who received a weightbearing CT scan. A pilot group of n=8 patients were included for a total of n=10 limbs. Average age was 50.1 +/- 14 and there were 38% female patients. All measurements were made on MPR (multiplanar reformation) axial reconstructions. Cobb angle measurements between the anatomic foot center, the second, the fourth metatarsal and the gutter bisector or medial gutter line were recorded by n=4 observers. Intraclass correlation (ICC) was produced using a two-way random effects model with absolute agreement and other statistical testing was performed by IBM SPSS Statistics for Windows, Version 27.0. Armonk, NY.

Results:

The average gutter bisector angle was 6.2 deg +/- 2.0 and the average angle between the medial base of the 1st metatarsal head, lateral base of the 5th metatarsal head and the posterior calcaneus was 33.0 deg +/- 2.6. Amongst the observers, the ICC for these landmarks were 0.95 and 0.96 respectively. The average cobb angle measurement between the gutter bisector angle and the second metatarsal was 8.3 deg +/- 7.3, with a corresponding ICC of 0.96. The average cobb angle measurement between the gutter bisector angle and the anatomic foot center was 5.6 deg +/- 4.3 and the average cobb angle measurement between the medial gutter line and the anatomic foot center was 6.23 deg +/- 6. Amongst the observers, the ICC for these measurements were 0.81 and 0.81 respectively.

Conclusion:

In a small pilot study of patients without osteoarthritis who underwent weight-bearing CT scans there was good (ICC>0.75-0.90) to excellent (ICC>0.90) agreement amongst observers for measurements of foot center axis and ankle rotation. These findings validate the reproducibility and agreement of these manually constructed measurements for assessing the relationship between the foot center axis and ankle rotation. Future studies will expand upon the use of these measurements to define non-arthritic anatomy. The anatomic foot center may be a useful guide for establishing intra-operative foot orientation when performing total ankle arthroplasty.

Midterm Prospective Evaluation of Structural Allograft Transplantation for Osteochondral Lesions of the Talar Shoulder

BACKGROUND

In cases of large osteochondral lesions of the talus (OLTs), fresh structural or bulk osteochondral allograft transplantation has yielded favorable outcomes in several retrospective and few prospective case series. The purpose of this study was to prospectively evaluate patients who received fresh structural allograft transplantation of the talar shoulder.

METHODS

A prospective evaluation of patients who received a fresh structural allograft of an OLT was performed. Preoperative imaging included magnetic resonance imaging (MRI) and/or computed tomography (CT) with plain radiographs. The following patient-reported outcomes questionnaires were administered preoperatively and yearly after surgery: 36-Item Short-Form Health Survey (SF-36), visual analog scale (VAS) for pain, and the Short Musculoskeletal Functional Assessment (SMFA). Preoperative and postoperative imaging were evaluated for allograft assimilation, evidence of arthritic changes, or functional range of motion abnormalities.

RESULTS

Thirty-one patients with a mean age of 41.4 years (±14.1, range 18-69) underwent structural fresh osteochondral allograft transplantation to the talar shoulder and were included in this study. The mean follow-up was 56.2 months (±36.1, range 24-142). The majority of patients were female (n=17, 54.8%), reported some history of prior ankle trauma (n=21, 67.7%), and underwent prior ankle surgery (n=23, 74.2%). The mean lesion size on CT scan was 1879 mm³ (n = 27) compared to the mean lesion size of 3877 mm³ (n = 21) on MRI. There was a significant improvement in the mean preoperative VAS score (P < .0001), SF-36 score (P < .0005), SMFA bother index (P < .0015), and the SMFA function index (P < .0001) at final follow-up. A total of 15 (48.4%) patients underwent an additional surgery following their osteochondral allograft transplant, most commonly arthroscopic debridement or removal of hardware, performed at an average of 25.2 (±13.0) from their index procedure. There was one failure that required a total ankle replacement. The overall graft survival rate was 96.8%.

CONCLUSION

Fresh, structural allograft transplantation resulted in significant improvement in patient-reported postoperative pain and function in patients suffering from OLTs. The graft survival rate was 96.8% at a mean of 56.2 months follow-up, with half of patients requiring a second procedure.

LEVEL OF EVIDENCE

Level IV, prospective case series.

Outcomes of Surgical Reconstruction Using Custom 3D-Printed Porous Titanium Implants for Critical-Sized Bone Defects of the Foot and Ankle

BACKGROUND

Treating critically sized defects (CSDs) of bone remains a significant challenge in foot and ankle surgery. Custom 3D-printed implants are being offered to a small but growing subset of patients as a salvage procedure in lieu of traditional alternates such as structural allografts after the patient has failed prior procedures. The long-term outcomes of 3D-printed implants are still unknown and understudied because of the limited number of cases and short follow-up durations. The purpose of this study was to evaluate the outcomes of patients who received custom 3D-printed implants to treat CSDs of the foot and ankle in an attempt to aid surgeons in selecting appropriate surgical candidates.

METHODS

This was a retrospective study to assess surgical outcomes of patients who underwent implantation of a custom 3D-printed implant made with medical-grade titanium alloy powder (Ti-6Al-4V) to treat CSDs of the foot and ankle between June 1, 2014, and September 30, 2019. All patients had failed previous nonoperative or operative management before proceeding with treatment with a custom 3D-printed implant. Univariate and multivariate odds ratios (ORs) of a secondary surgery and implant removal were calculated for perioperative variables.

RESULTS

There were 39 cases of patients who received a custom 3D-printed implant with at least 1 year of follow-up. The mean follow-up time was 27.0 (12-74) months. Thirteen of 39 cases (33.3%) required a secondary surgery and 10 of 39 (25.6%) required removal of the implant because of septic nonunion (6/10) or aseptic nonunion (4/10). The mean time to secondary surgery was 10 months (1-22). Multivariate logistic regression revealed that patients with neuropathy were more likely to require a secondary surgery with an OR of 5.76 (P = .03).

CONCLUSION

This study demonstrated that 74% of patients who received a custom 3D-printed implant for CSDs did not require as subsequent surgery (minimum of 1-year follow-up). Neuropathy was significantly associated with the need for a secondary surgery. This is the largest series to date demonstrating the efficacy of 3D-printed custom titanium implants. As the number of cases using patient-specific 3D-printed titanium implant increases, larger cohorts of patients should be studied to identify other high-risk groups and possible interventions to improve surgical outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

Intra-Articular Synovial Fluid With Hematoma After Ankle Fracture Promotes Cartilage Damage In Vitro Partially Attenuated by Anti-Inflammatory Agents

BACKGROUND

Intra-articular ankle fracture (IAF) causes posttraumatic osteoarthritis (PTOA), but the exact mechanism is unknown. Proinflammatory mediators have been shown to be present in the synovial fluid fracture hematoma (SFFH) but have not been linked to cartilage damage. The purpose of this study was to determine if the SFFH causes cartilage damage and whether this damage can be attenuated by commercially available therapeutic agents.

METHODS

Synovial fluid was obtained from 54 IAFs and cultured with cartilage discs from the dome of fresh allograft human tali and randomly assigned to one of the following groups: (A) control-media only, (B) SFFH from days 0 to 2 after fracture, (C) SFFH from days 3 to 9, (D) SFFH from days 10 to 14, (E) group B + interleukin 1 receptor antagonist (IL-1Ra), and (F) group B + doxycycline. The cartilage discs underwent histological evaluation for cell survival and cartilage matrix components. The spent media were analyzed for inflammatory mediators.

RESULTS

Cartilage discs cultured with SFFH in groups B, C, and D demonstrated significantly increased production of cytokines, metalloproteinases (MMPs), and extracellular matrix breakdown products. Safranin O staining was significantly decreased in group B. The negative effects on cartilage were partially attenuated with the addition of either IL-1RA or doxycycline. There was no difference in chondrocyte survival among the groups.

CONCLUSION

Exposure of uninjured cartilage to IAF SFFH caused activation of cartilage damage pathways evident through cartilage disc secretion of inflammatory cytokines, MMPs, and cartilage matrix fragments. The addition of IL-1Ra or doxycycline to SFFH culture partially attenuated this response.

CLINICAL RELEVANCE

IAFs create an adverse intra-articular environment consisting of significantly increased levels of inflammatory cytokines and MMPs able to damage cartilage throughout the joint. These data suggest that the acute addition of specific inflammatory inhibitors may decrease the levels of these proinflammatory mediators.

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.

State regulation positively impacts opioid prescribing patterns in ankle fracture surgery: A national and state-level analysis

BACKGROUND

The impact of time and state regulation on opioid prescribing in orthopedic trauma is not well known. The purpose of this study is to evaluate the impact of time and state-level opioid legislation on 90-day perioperative opioid prescribing in ankle fracture surgery from 2010 to 2019.

METHODS

This is a retrospective, cohort study using a national insurance database including commercial insurance, Medicare, Medicaid, and cash pay patients to evaluate 30-day pre-operative to 90-day post-operative opioid prescription filling in 40,286 patients ages 18 and older undergoing Current Procedural Terminology codes 27,766, 27,769, 27,792, 27,814, 27,822, and/or 27,823 between 2010 and 2019 in all 50 United States. The primary study outcome was initial and cumulative perioperative opioid prescription filling and rates of filling and refills over the study timeframe.

RESULTS

Mean first prescription volume has not changed dramatically from 2010 (37 oxycodone 5 mg pills) to 2019 (33.3 oxycodone 5 mg pills). However, cumulative prescriptions within the 30PRE-90POST timeframe have decreased considerably from 2010 (128.5 oxycodone 5 mg pills) to 2019 (70.4 oxycodone 5 mg pills), and cumulative prescription filling in years 2018 and 2019 was significantly less than in 2010. Legislation targeting duration or duration and volume had the largest impacts on initial and cumulative opioid prescribing.

CONCLUSIONS

In ankle fracture surgery, states with opioid prescribing legislation had larger reductions in perioperative opioid prescribing compared to states without opioid legislation. Legislation targeting duration or duration and volume had the largest impacts on opioid prescribing.

LEVEL OF EVIDENCE

Level III, Retrospective prognostic cohort study.

Chronic Achilles Tendon Ruptures: From Bracing Treatment to Complex Reconstruction

The optimal management of chronic Achilles tendon injuries continues to be debated. The tension-length relationship and intrinsic viscoelasticity of the native tendon that allows efficient propulsion during ambulation are difficult to restore once the tendon has been injured. Missed or misdiagnosed injuries or failure of surgical or nonsurgical management of acute Achilles tendon ruptures can lead to the tendon healing in an elongated position or lack of healing altogether. This condition results in persistent weakness, pain, and functional debilitation for the patient. Understanding the tendon and muscle properties will inform the choice of treatment. Nonsurgical treatment options are primarily bracing treatment and physical therapy. Surgical treatment options involve direct repair, reconstruction with local tissue, allograft or autograft, and tendon transfer. Various options and techniques for reconstruction are described to assist in optimizing management of this challenging clinical problem.

Histological and Inflammatory Cytokine Analysis of Osteochondral Lesions of the Talus After Failed Microfracture: Comparison With Fresh Allograft Controls

Background:

The most common first-line treatment of osteochondral lesions of the talus (OLTs) is microfracture. Although many patients do well with this procedure, a number fail and require reoperation. The mechanism of failure of microfracture is unknown, and to our knowledge there has been no research characterizing failed microfracture regarding histological and inflammatory makeup of these lesions that may contribute to failure.

Purpose:

To characterize the structural and biochemical makeup of failed microfracture lesions.

Study Design:

Case series; Level of evidence, 4.

Methods:

Specimens from 8 consecutive patients with symptomatic OLTs after microfracture who later underwent fresh osteochondral allograft transplantation were analyzed. For each patient, the failed microfracture specimen and a portion of the fresh allograft replacement tissue were collected. The allograft served as a control. Histology of the failed microfracture and the allograft replacement was scored using the Osteoarthritis Research Society International (OARSI) system. Surface roughness was also compared. In addition, tissue culture supernatants were analyzed for 16 secreted cytokines and matrix metalloproteinases (MMPs) responsible for inflammation, pain, cartilage damage, and chondrocyte death.

Results:

The OARSI grade, stage, and total score as well as surface smoothness were significantly worse in the failed microfracture sample, indicating better cartilage and bone morphology for the allografts compared with the failed microfracture lesions. Analyzed cytokines and MMPs were significantly elevated in the microfracture tissue culture supernatants when compared with fresh osteochondral tissue supernatants.

Conclusion:

These data demonstrate a significantly rougher cartilage surface, cartilage and subchondral bone histology that more closely resembles osteoarthritis, and elevated inflammatory cytokines and MMPs responsible for pain, inflammation, cartilage damage, and chondrocyte death when compared with fresh osteochondral allografts used as controls.

High-strength, porous additively manufactured implants with optimized mechanical osseointegration

Optimization of porous titanium alloy scaffolds designed for orthopedic implants requires balancing mechanical properties and osseointegrative performance. The tradeoff between scaffold porosity and the stiffness/strength must be optimized towards the goal to improve long term load sharing while simultaneously promoting osseointegration. Osseointegration into porous titanium implants covering a wide range of porosity (0%-90%) and manufactured by laser powder bed fusion (LPBF) was evaluated with an established ovine cortical and cancellous defect model. Direct apposition and remodeling of woven bone was observed at the implant surface, as well as bone formation within the interstices of the pores. A linear relationship was observed between the porosity and benchtop mechanical properties of the scaffolds, while a non-linear relationship was observed between porosity and the ex vivo cortical bone-implant interfacial shear strength. Our study supports the hypothesis of porosity dependent performance tradeoffs, and establishes generalized relationships between porosity and performance for design of topological optimized implants for osseointegration. These results are widely applicable for orthopedic implant design for arthroplasty components, arthrodesis devices such as spinal interbody fusion implants, and patient matched implants for treatment of large bone defects.

Improvement in Health-Related Quality of Life After Total Ankle Arthroplasty Compares Well With Other Successful Orthopaedic and Nonorthopaedic Procedures

Background. Ankle arthritis is a major cause of disability. Orthopaedic literature suggests improvement in health-related quality of life (HRQOL) after total ankle arthroplasty (TAA). This has not been compared with improvements observed in successful orthopaedic and nonorthopaedic procedures, including anterior cervical discectomy/fusion (ACDF), total knee arthroplasty (TKA), coronary artery bypass grafting (CABG), and orthotopic liver transplant (OLT). We hypothesize that the effects after TAA are comparable to several successful surgical procedures. Methods. 500 consecutive TAA patients were included and grouped with 2 other large series. Short Form-36 (SF36) were collected at standardized intervals. A systematic literature review identified studies comparing preoperative and postoperative SF36 physical (PCS) and mental component summary (MCS) scores. Using meta-analyses, we pooled the data for each procedure to compare with the TAA group. Results. Patients in all cohorts had preoperative SF36 MCS and PCS scores that were significantly lower than that in the general population. Improvements in HRQOL after TAA were not statistically different from improvements reported in PCS and MCS after ACDF, TKA, and OLT. However, improvement in PCS after TAA was better than that observed after CABG. Conclusions. Disability with ankle arthritis is severe. Disability associated with cervical disc disease, knee arthrosis, coronary artery disease, and liver failure is also severe, with surgical intervention providing major improvements in HRQOL postoperatively. The improvement in HRQOL after TAA did not differ statistically from ACDF, TKA, CABG, and OLT. Our investigation suggests that the HRQOL benefits of TAA meet benchmarks set by some of modern medicine's best.Levels of Evidence: Level III: Systematic review.

Three-Dimensional Printed Cage in Patients With Tibiotalocalcaneal Arthrodesis Using a Retrograde Intramedullary Nail: Early Outcomes

Introduction. Segmental bone loss in the hindfoot hinders the chance of successful outcomes. Tibiotalocalcaneal arthrodesis is a reliable option; nevertheless, the risk of nonunion is high. Three-dimensional (3D) printed titanium implants offer a strong scaffold that can be customized and has demonstrated encouraging healing rates. In this study, we described the clinical outcomes and the radiologic union rate of a case series of patients with hindfoot arthrodesis, using a retrograde intramedullary nail associated to a 3D printed titanium cage. Methods. Seven patients undergoing hindfoot arthrodesis, using a retrograde intramedullary nail associated to a custom 3D printed titanium cage, were included. Demographic data were collected. Functional outcomes were assessed using the American Orthopedic Foot and Ankle Score and the Visual Analogue Scale for pain. Hindfoot alignment and radiographic union were evaluated using weight-bearing radiographs and computed tomography scan, respectively. Results. A total of 6 (85%) patients had more than 50% bony bridging. Only 1 patient underwent below knee amputation due to recurrence of chronic osteomyelitis. Two additional patients had minor complications. Conclusion. Tibiotalocalcaneal arthrodesis using customized titanium cages for patients with large bone defects has shown a high rate of union in those at risk of nonunion. However, further research with larger series is needed.Levels of Evidence: Level IV: Case series.

Analysis of 408 Total Ankle Arthroplasty Adverse Events Reported to the US Food and Drug Administration From 2015 to 2018

Background. Total ankle arthroplasty (TAA) use has increased with newer generation implants. Current reports in the literature regarding complications use data extracted from high-volume centers. The types of complications experienced by lower-volume centers may not be reflected in these reports. The purpose of this study was to determine a comprehensive TAA adverse event profile from a mandatory-reporting regulatory database. Methods. The US Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database was reviewed from 2015 to 2018 to determine reported adverse events for approved implants. Results. Among 408 unique TAA device failures, the most common modes of failure were component loosening (17.9%), intraoperative guide or jig error (15.4%), infection (13.7%), and cyst formation (12.7%). In addition, the percentage distribution of adverse event failure types differed among implants. Conclusion. The MAUDE database is a publicly available method that requires mandatory reporting of approved device adverse events. Using this report, we found general agreement in types of complications reported in the literature, although there were some differences, as well as differences between implants. These data may more accurately reflect a comprehensive profile of TAA complications as data were taken from a database of all device users rather than only high-volume centers.Levels of Evidence: NA.

Avascular Necrosis of the Talus After Subchondroplasty

BACKGROUND

Subchondroplasty (SCP) is a relatively new procedure, developed in 2007 for the treatment of bone marrow lesions (BMLs), that has shown promising results in the knee through several different case series. The foot and ankle literature, however, is sparse, with only a few documented case reports or case series. At our institution, we have identified several patients with complications after this specific procedure. As a result, we report our case series of patients who developed talar avascular necrosis (AVN) after undergoing SCP.

METHODS

A retrospective review was performed of patients who underwent SCP for a talar BML at our facility or who were referred to our facility after undergoing SCP at an outside institution. Patients were included if they developed radiographic evidence of talar AVN after the procedure. Patient demographics, comorbidities, concomitant intraoperative procedures, complications, and subsequent interventions were reviewed.

RESULTS

Seven patients were identified as having radiographic evidence of talar AVN after SCP. Average time interval was 23 months postoperative from index procedure to radiographic confirmation of AVN. Two of the index procedures were performed at our institution, whereas 5 of the index procedures were performed at outside institutions and referred for further management. Three patients had documented risk factors for AVN before the SCP procedure. All 7 patients were symptomatic from the AVN.

CONCLUSION

We identified 7 patients who went on to develop talar AVN after having undergone SCP.

LEVEL OF EVIDENCE

Level IV, case series.

Impact of Early Weightbearing After Ankle Arthroscopy and Bone Marrow Stimulation for Osteochondral Lesions of the Talus

BACKGROUND

Osteochondral lesion of the talus (OLT) may be caused by osteochondritis dissecans, osteochondral fractures, avascular necrosis, or focal arthritic changes. For certain focal cartilage defects, bone marrow stimulation (BMS) has been a widely used technique to restore a fibrocartilage substitute overlying the defect. There are various postoperative weightbearing protocols for this procedure, with no single gold standard method.

PURPOSE

To retrospectively review the outcomes of patients undergoing ankle arthroscopy with concomitant BMS to determine outcomes based on postoperative weightbearing status.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

We retrospectively reviewed the records of patients who underwent ankle arthroscopy with BMS for OLTs between 2015 and 2018. Patients were placed into 2 cohorts based on postoperative immobilization status: the nonweightbearing (NWB) group and the weightbearing-as-tolerated (WBAT) group. Patient characteristics obtained included age, sex, comorbidities, and etiology of talar pathology. Outcomes included the pain visual analog scale (VAS), range of motion (ROM), complications, time to first weightbearing, and the method and length of immobilization. Patients who were lost to follow-up before 30 days were excluded. The chi-square test was used to compare categorical variables between cohorts, and the t test was used for continuous variables.

RESULTS

A total of 69 patients met the inclusion criteria for this study, 18 in the WBAT group and 51 in the NWB group. The mean lesion size was 9.48 × 9.21 mm (range, 3-15 mm × 2-20 mm) for the NWB group and 9.36 × 9.72 mm (range, 5-14 mm × 6-20 mm) for the WBAT group (P > .05). The VAS scores improved from 4.40 to 0.67 for the WBAT group and from 6.33 to 2.55 for the NWB group, with the difference in final values reaching statistical significance (P = .0002). Postoperative ROM was not significantly different between the groups. There were 4 repeat operations within the NWB cohort.

CONCLUSION

The surgical management of OLTs can be challenging, and the postoperative weightbearing protocol can be an extra obstacle for the patient to navigate. We found no difference in pain, ROM, or complications when allowing immediate, full WBAT.

Talonavicular Joint-Sparing 3D Printed Navicular Replacement for Osteonecrosis of the Navicular

Pathology of the navicular can be a difficult entity to treat, particularly when the injury has progressed to osteonecrosis. While various nonoperative and operative modalities have been described, the emerging field of additive manufacturing has become a potential solution to this difficult problem in certain scenarios. While these implants have largely been used for fusion in the past, the concept of joint sparing with 3D printed implants is also emerging, and this case highlights a patient treated with a talonavicular joint-sparing, patient-specific 3D printed total navicular replacement.

Comparison of 3D Printed Spherical Implants versus Femoral Head Allografts for Tibiotalocalcaneal Arthrodesis

Successful tibiotalocalcaneal (TTC) arthrodesis can be difficult to achieve in patients with bulk bone defects even with the use of femoral head allograft. Retrograde intramedullary nail placement through custom 3-dimensional (3D) spherical implants is an innovative option for these patients. The purpose of this study was to compare fusion rates, graft resorption, and complication rates between patients undergoing TTC fusion with 3D sphere implants versus femoral head allografts. Patients who underwent TTC arthrodesis with an intramedullary nail along with a 3D spherical implant (n = 8) or femoral head allograft (n = 7) were included in this study. The rate of successful fusion of the tibia, calcaneus, and talar neck to the 3D sphere or femoral head allograft was compared between the groups. The rate of total fused articulations was significantly higher in the 3D sphere group (92%) than the femoral head allograft group (62%; p = .018). The number of patients achieving successful fusion of all 3 articulations was higher in the 3D sphere group (75%) than the femoral head allograft group (42.9%, p = .22). The rate of graft resorption was significantly higher in the femoral head allograft group (57.1%) than the 3D sphere group (0%, p = .016). There were no significant differences between the groups in terms of complications. These data demonstrate that the use of a custom 3D printed sphere implant is safe in patients with severe bone loss undergoing TTC arthrodesis with a retrograde intramedullary nail and may result in improved rates of successful arthrodesis.

Total Ankle Total Talus Replacement Using a 3D Printed Talus Component: A Case Report

The 3D custom total talus replacement is a novel treatment for avascular necrosis of the talus. However, patients who require a total talus replacement often have concomitant degenerative changes to the tibiotalar, subtalar, or talonavicular joints. The combined 3D custom total ankle-total talus replacement (TATTR) is used for patients with an unreconstructable talus and adjacent tibial plafond involvement. The goal of performing a TATTR is to provide pain relief, retain motion at the tibiotalar joint, maintain or improve the patient's functional status, and minimize limb shortening. TATTR is made possible by 3D printing. The advent of 3D printing has allowed for the accurate recreation of the native talar anatomy with a talar dome that can be matched to a total ankle replacement polyethylene bearing. In this article, we will discuss a case of talar avascular necrosis treated with a combined TATTR and review the current literature for TATTR.

Fresh Osteochondral Allograft Transplantation for Osteochondral Lesions of the Talus: A Systematic Review

Osteochondral lesions of the talus (OLTs) are difficult to treat. Despite a multitude of interventions, there are no generally-agreed-upon guidelines regarding treatment. The objective of this study was to conduct a systematic review of clinical outcomes after fresh osteochondral allografts transplantation of the talus. PubMed, the Cochrane Central Register of Controlled Trials, EMBASE, and Medline were searched using PRISMA guidelines. Studies that evaluated outcomes after fresh osteochondral allograft transplantation for OLTs were included. Clinical outcomes, according to standardized scoring systems, such as the American Orthopaedics Foot & Ankle Society (AOFAS) Ankle/Hindfoot Scale and the Visual Analog Scale (VAS) were compared across studies. The literature search yielded 12 eligible studies with a mean Coleman Methodology Score of 68.1 (57-79). A total of 191 patients were included with an average age of 37.5 (17-74) years and average follow-up of 56.8 (6-240) months. The AOFAS Ankle/Hindfoot score was obtained pre- and postoperatively in 6 of the studies and had significant improvements in each (p < .05). Similarly, the VAS pain score was evaluated in 5 studies and showed significant decreases from pre- to postoperatively (p < .05). While there were no reported short-term complications, 21.6% of patients required minor subsequent procedures, most commonly arthroscopic debridement and hardware removal. The aggregate graft survival rate was 86.6%. Based on these findings, osteochondral allograft transplantation for OLTs results in positive outcomes with high rates of graft survival and patient satisfaction at intermediate follow-up.

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.

Adverse events involving hallux metatarsophalangeal joint implants: Analysis of the United States Food and Drug Administration data from 2010 to 2018

BACKGROUND

The prevalence of osteoarthritis of the hallux metatarsophalangeal joint (MTPJ) is 1 in 40 people over the age of 50. Surgical treatment options for MTPJ arthritis include joint preservation, joint resurfacing, and arthrodesis. Hallux MTPJ implants have evolved over the past several decades, but are associated with various complications. The aim of this study was to examine the MAUDE database to determine reported adverse events for hallux MTPJ implants.

MATERIALS AND METHODS

The US Food and Drug Administration's (FDA) Manufacturer and User Facility Device Experience (MAUDE) database was reviewed from 2010 to 2018 to review voluntary reported adverse event reports for approved implants within the United States. We recorded the type of adverse event and excluded duplicate reports and those extracted from already published literature.

RESULTS

Among 64 reported hallux MTPJ implant adverse events, the most common modes of adverse events were component loosening (34%), infection (14.1%), component fracture (9.4%), inflammation (9.4%), and allergic reaction (7.8%). Regarding implant type, Cartiva SCI had the highest percentage of adverse events (23.4%), followed by Arthrosurface ToeMotion (20.3%), Ascension MGT (12.5%), Arthrosurface HemiCAP® (10.9%), Futura primus (9.4%), and Osteomed Reflexion (6.3%). There was an increase in reported adverse events after 2016. The MAUDE database does not report the total incidence of implant insertion.

CONCLUSION

Our study of the MAUDE database demonstrated that component loosening and infection are the most common modes of adverse events for hallux MTPJ implants. Cartiva accounted for one-fourth of the implant-related adverse events during our study period, followed by ToeMotion, and Ascension MGT implants. Continued reporting of adverse events will improve our understanding on short and long-term complications of various hallux MTPJ implants.

LEVEL OF EVIDENCE

Level IV; Case Series from Large Database Analysis; Treatment Study.

Incidence and Risk Factors for Flap Coverage After Total Ankle Arthroplasty

BACKGROUND

Wound complications following total ankle arthroplasty (TAA) can have a significant impact on patient morbidity, particularly when they require flap coverage. We sought to determine the risk factors associated with the need for flap coverage after TAA and hypothesized that medical and operative risk factors such as diabetes and additional procedures would be associated with the need for flap coverage after TAA.

METHODS

We performed a single-center retrospective review of TAAs from April 2007 to February 2019. Patient demographics and medical comorbidities were collected, in addition to other procedures performed at the time of TAA. Patients were stratified by the need for flap coverage, and unadjusted inferential statistics were performed to evaluate the risk factors associated with subsequent need for flap coverage.

RESULTS

Among 2065 patients undergoing TAA, 28 (1.4%) patients required flap coverage after the index arthroplasty. Patients requiring flap coverage were older (P = .045), had higher Charlson comorbidity indices (P = .017), and had higher rates of diabetes and pulmonary disease (P = .038). Patients requiring flap coverage also had higher rates of additional procedures (P = .043, P = .007). The most common flap was a radial forearm free flap, which was performed in 14 (50%) patients. Twenty-one patients (75%) requiring flap coverage had a stable, plantigrade foot at median 1.5-year follow-up.

CONCLUSION

Patient and operative risk factors, including advanced age, increased comorbidity burden, diabetes, pulmonary disease, and increased number of simultaneous procedures, were significantly associated with need for subsequent flap coverage. This should be considered as the indications for TAA expand.

LEVEL OF EVIDENCE

Level III, retrospective, prognostic cohort study.