Comparison of Dynamic Versus Static Locked Retrograde Tibiotalocalcaneal Arthrodesis With Intramedullary Nail Fixation: Evaluation of the RAIN Database.

Hindfoot osteoarthritis (OA) or deformity involving the ankle and subtalar joint is a disabling condition. Tibiotalocalcaneal (TTC) fusion is an effective salvage option in pathologies where total ankle replacement is contraindicated. The purpose of this study is to compare the union rate of the ankle joint in proximal static versus dynamically locked retrograde intramedullary nail fixation for tibiotalocalcaneal arthrodesis. An institutional review board-approved comprehensive chart and radiographic review was performed. TTC arthrodesis performed in patients with OA, post-traumatic arthritis, or deformity corrected by retrograde nail were included. Patients with Charcot arthropathy, failed joint replacement, neuropathy, or avascular necrosis were excluded. The primary outcome was ankle joint union with secondary measure of mean time to fusion. A total of 60 patients met inclusion criteria with 30 in the static group (SG) and 30 in the dynamic group (DG). The average age of the static group (SG) and dynamic group (DG) was 56.9 and 54.1 years, respectively. Mean body mass index was 34.03 kg/m2 for SG and 33.43 kg/m2 for DG. The union rate of the ankle joint was slightly higher in the DG but not statistically significant [SG 83.3%, DG 86.6%, p > .05 (p = .83)]. Time to fusion (TTF) in SG was 111.6 days compared to 97.2 days in DG. Dynamically locked intramedullary nails allow continued compression across the arthrodesis site as fusions remodel. Time to union and union rate of the ankle joint was superior in the dynamic group but this was not statistically significant. In this cohort, union rates were excellent in both groups, and no statistically significant difference was seen in the number of nonunions.

A Study of Tibial Cyst Formation in Modular Stemmed Total Ankle Arthroplasty: Exploring a Possible Relationship to Smooth and Porous Coating on the Stem Segments.

Vertical fixation through stemmed components has been a successful strategy in total ankle arthroplasty. Research in hip replacement surgery has demonstrated increased rates of stress shielding, aseptic loosening, thigh pain, and cystic formation around stemmed femoral implants extensively coated with porous surfaces. While some ankle prostheses have integrated porous coating technology with stemmed tibial implants, there is little to no research investigating the potential negative effects of bone bonding to the tibial stems and possible impact on tibial cyst formation. We performed a retrospective cohort study comparing the incidence of periprosthetic tibial cyst formation in smooth versus fully porous-coated stemmed tibial implants after undergoing total ankle implant arthroplasty. Radiographs were compared for postoperative rates of tibial cyst formation and bone bonding to the tibial stems. Relative risk for reoperation between the smooth and porous-coated implants was investigated. The smooth-stem group showed no incidence of tibial cyst formation nor signs of significant bone bonding to the tibial stems; however, the follow-up matched porous-coated group showed a rate of 63% of cystic formation with associated evidence of bone bonding on final radiographic follow-up (p < .01). Relative risk for reoperation was 0.74. Despite a higher incidence of tibial cyst formation in the stemmed ankle arthroplasty groups with porous coating, reoperation rates were similar. We theorize that the proximal bonding to the porous stem surface could impact the distal stems and result in the observed increase in cyst formation.

The Role of Secondary Imaging Techniques for Assessing Bone Mineral Density in Elderly Ankle Fractures.

Elderly ankle fractures in the elderly represent a substantial healthcare burden. Dual-energy x-ray absorptiometry (DXA) is the gold standard for diagnosis of osteoporosis. However, there is emerging research regarding secondary imaging techniques to evaluate bone mineral density (BMD). The purpose of this systematic review was to summarize the role of secondary imaging techniques for measuring BMD in elderly ankle fractures. A literature search was undertaken using relevant search terms. Articles were screened for suitability and data extracted where studies met inclusion criteria and were of sufficient quality. Eight studies were included in the systematic review. Computed tomography (CT) may have a role in preoperative surgical planning, provide an explanation for injury patterns in elderly patients, and may be correlated with clinical outcomes. High-resolution peripheral quantitative CT may be better suited than DXA for the assessment of ankle fractures due to the resolution of the image and its ability to distinguish between bone compartments, as well as provide a more accurate estimation of bone quality. Quantitative ultrasound has shown promise as a tool for measuring BMD in patients with osteoporosis, but is not able to detect osteoporosis in patients with ankle fractures. This paper helps define the role of each modality in the spectrum of care in the evaluation of osteoporosis as it pertains to elderly ankle fractures.

The Safety Profile of Same-Day Outpatient Total Ankle Arthroplasty.

There has been significant change in the health care policy in the United States in recent years with an increasing focus on health care costs and patient satisfaction. One strategy of cost containment is to transition outpatient surgery away from high cost hospital environments. Total ankle arthroplasty has begun the evolution to outpatient settings; however, there is limited published literature on the results of outpatient total ankle arthroplasty (TAA). The purpose of the present study was to review the safety profile of same day outpatient TAA at an ambulatory surgery center. A review of consecutive patients who underwent same day outpatient TAA for end-stage ankle arthritis with a minimum of 12 months' follow-up was performed. The primary outcomes assessed were the incidence of perioperative adverse medical events, hospital admissions related to the procedure, and postoperative complications (minor and major). Univariate analyses were performed. Fifty-one patients who underwent same-day TAA between June 2016 and July 2018 were included; mean follow-up was 20.7 months (± 7.6). The mean age at time of surgery was 56.5 years (± 7.2), with a mean body mass index of 30.4 (± 5.3). Overall, there were no perioperative adverse medical events or hospital admissions related to the procedure. Five minor complications (9.8%) and 7 major (13.7%) were recorded. Of the major complications, only 1 required TAA revision. Implant survivorship during the most recent follow-up was 98%. The present study suggests that TAA can be performed safely in an outpatient ambulatory setting. Additional comparative studies with larger TAA cohorts and patient reported outcomes are warranted.

Total Ankle Arthroplasty With Anatomic Lateral Ankle Stabilization (ATLAS) in Moderate and Severe Pre-operative Varus Alignment.

The purpose of the present study was to assess the early clinical and radiographic outcomes for patients who underwent TAA and Anatomic Lateral Ankle Stabilization (ATLAS) using synthetic graft for instability in moderate and severe preoperative varus alignment. Seven ankles with moderate or severe varus alignment underwent TAA with a 3rd generation prothesis (INBONE-2) and ATLAS using synthetic graft between September 2018 and February 2019 at a single institution, and were at least 1 year postoperative (mean 13.3 months, range 12-15). Medical records and charts were reviewed for revisions, reoperations, and complications. Weightbearing radiographs were assessed using tibiotalar alignment parameters preoperatively, and during the latest follow-up. Survivorship for INBONE-2 with ATLAS was 100%; recurrent instability was not observed. Symptomatic talonavicular joint arthritis was recorded for a single patient 12 months postoperatively; no revisions, or reoperations were performed. Coronal alignment improved significantly from 17.7 ± 9.3 (range, 10.1-33.6) to 2.3 ± 1.2 (range, 0.9-4.4) degrees (p < .006), and all ankles achieved neutral alignment in a single stage. Regarding sagittal alignment, 2 ankles (28.5%) were translated anteriorly and the rest were neutral (71.5%) preoperatively. Significant posterior translation was observed and during the latest follow-up, 4 ankles were neutral (57.1%) and 3 posterior (42.9%) (p < .009). Satisfactory outcomes were observed at a minimum of 1-year follow-up for patients with moderate or severe varus alignment who underwent TAA with INBONE-2 and ATLAS. ATLAS may afford advantages over previously described repair techniques. Comparative studies between the Brostrum-Gould and ATLAS are warranted.

Risk Factors for Early Failure of Fourth Generation Total Ankle Arthroplasty Prostheses.

A number of 2-component, fourth generation total ankle arthroplasty (TAA) prostheses have been introduced to the market in the past few years, as the popularity and indications for TAA have continued to expand. The purpose of the present study was to identify independent risk factors for the early failure of fourth generation TAA prostheses. A total of 97 ankles underwent TAA with a fourth generation prostheses (INFINITY, CADENCE) between August 2015 and June 2018 at a single institution and were at least 6 months postoperative (mean 18.3 months, range 6-43). The primary outcome assessed was the need for revision surgery, defined as removal of 1 or both metal components for any reason, excluding infection. Baseline patient demographics, characteristics, radiographic alignment parameters, and distal tibia cortical bone thickness (CBT) were assessed. Revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively. Univariate and multivariate analyses were performed. Three ankles (3.1%) underwent revision surgery for aseptic loosening at a mean of 24.3 (range, 16-31) months; all had a CBT <4 mm. Independent predictors for reoperation were CBT <4 mm, presence of diabetes, and ipsilateral hindfoot fusion (p = .04). No associations were identified for purported risk factors (age, body mass index, and coronal deformity). The present study is the first to suggest a potential relationship between reduced CBT of the distal tibia, and TAA failure. Additional studies are warranted to better understand the role of bone density in TAA survivorship.

Bone Mineral Density Testing in Patients Undergoing Total Ankle Arthroplasty: Should We Pay More Attention to the Bone Quality?

Total ankle arthroplasty (TAA) has become one of the standard treatments for end-stage ankle arthritis. Long-term TAA survivorship is reported from 63% to 95%, with aseptic loosening being the most common mode of failure. Several studies have shown that low bone mineral density (BMD) of the hip affects the longevity of prosthetic implants. The role of Dual energy X-ray absorptiometry for TAA has not been established. The purpose of this review was to define the role of BMD in TAA outcomes and the role of Dual energy X-ray absorptiometry in measuring periprosthetic BMD. There is a paucity of information and published literature regarding the relationship between BMD and TAA. From attempting this systematic review, we hope to highlight that much of the focus in total ankle arthroplasty has emphasized implants and relatively little has focused on the quality of bone into which the prostheses are implanted.

Anterior Ankle Incision Wound Complications Between Total Ankle Replacement and Ankle Arthrodesis: A Matched Cohort Study.

The anterior incision is commonly used for total ankle replacement (TAR) and ankle arthrodesis. Historically, the anterior incision has demonstrated a high incidence of complications. The purpose of this study was to evaluate anterior incisional healing and soft tissue complications between TAR and ankle arthrodesis with anterior plate fixation.This was an IRB-approved retrospective review of wound healing and other complications among 304 patients who underwent primary TAR (191 patients) or ankle arthrodesis (113 patients) via the anterior approach over a 4-year period. The operative approach, intraoperative soft tissue handling, and postoperative protocol for the first 30 days were the same between groups. The mean follow-up was 11.8 months. To diminish the effect of selection bias, a subgroup analysis was performed comparing 91 TAR patients matched to an equal number of demographically similar ankle arthrodesis patients. Overall, 19.7% of patients experienced delayed wound healing greater than 30 days. Although the TAR and arthrodesis subgroups had dissimilar demographics, there was no difference in outcomes. Between matched pairs, no statistically significant differences were observed; however, trends were identified with matched cohort groups when compared to the overall patient series. These trends toward statistically significant differences in delayed wound healing and incidence of wound care in the matched cohort groups warrants further investigation in larger series or multicenter study. Further work is needed to identify the modifiable risk factors associated with the anterior ankle incision.

Association Between Bone Mineral Density and Elderly Ankle Fractures: A Systematic Review and Meta-Analysis.

Ankle fractures are becoming increasingly more common in the elderly population and present a significant burden to the United States health care system. Many factors have been associated with fragility ankle fractures including age, gender, body mass index, diabetes, tobacco use, and osteoporosis. However, the literature is inconsistent regarding the relationship between ankle fractures and osteoporosis. The primary aim of this meta-analysis was to quantify the relationship between bone mineral density (BMD) in elderly patients with ankle fractures compared with BMD in elderly patients without ankle fractures. A literature search was undertaken using relevant search terms. Articles were screened for suitability and data extracted where studies met inclusion criteria and were of sufficient quality. Data were combined using standard meta-analysis methods. Seven studies were used in the final analysis. A small-pooled effect size was found indicating the control group had increased BMD regardless of measurement used (95% confidence interval 0.09-0.58; I2 = 98.39%). Lower femoral neck BMD showed a small-pooled effect size (femoral neck 0.36; 95% confidence interval 0.00-0.73; I2 = 94.91%) with the ankle fracture cohort. This is the first meta-analysis to quantify the relationship between BMD and ankle fractures in the elderly population. Elderly ankle fractures showed a significant association with femoral neck BMD. The current data can be used in orthopedic clinics and Fracture Liaison Service programs to assign the appropriate subgroup of ankle fracture patients to investigative and treatment groups, assess fracture risk, and serve as an indication for secondary fracture prevention by stimulating an osteoporosis prevention workup. There may be a role for a team approach to fracture care including metabolic optimization.

A Review of 399 Total Ankle Replacements: Analysis of Ipsilateral Subtalar Joint Arthrodesis and Associated Talar Component Subsidence.

Total ankle replacement (TAR) is an accepted treatment for end-stage ankle arthritis. When concurrent subtalar joint pathologic features exist, ipsilateral subtalar joint arthrodesis (STJA) can be performed either simultaneous with TAR or as a staged procedure. Limited data exist on the effect of talar component subsidence and prosthesis survivorship. The present study purpose was to evaluate the effect of STJA on talar component subsidence after primary TAR and its effect on TAR survivorship. All patients, a minimum of 18 years old, from a single institution with modern-generation TAR and 1-year minimum follow-up data available were evaluated. The study group included patients who had also undergone STJA, and the control group (no STJA) was matched 1:1 by age, gender, and prosthesis. The initial postoperative weightbearing and most recent weightbearing radiographs were compared for talar component subsidence. We reviewed 399 primary TARs from 2004 to 2012. A total of 33 patients with ipsilateral STJA met the inclusion criteria and had an appropriate control group match. In the study group, 8 patients required a return to the operating room for 4 revisions and 4 reoperations at a median follow-up point of 24.3 months. Of the controls, 9 patients required a return to the operating room, with 4 revisions and 5 reoperations at a median follow-up point of 38.4 months. No statistically significant radiographic differences were found between the 2 groups. Primary TAR and ipsilateral STJA were infrequently required (41 of 399; 10.3%). TAR did not result in decreased survivorship when performed with ipsilateral STJA at an early follow-up point. Further study is warranted to determine any differences among previous, simultaneous, and subsequent STJA with ipsilateral TAR, and a matched longitudinal analysis is needed to determine longer term survivorship.

Ankle Arthrodesis: A Retrospective Analysis Comparing Single Column, Locked Anterior Plating to Crossed Lag Screw Technique.

Ankle arthrodesis is performed to eliminate pain due to end-stage osteoarthritis, regardless of etiology. This procedure remains the reference standard treatment for end-stage ankle arthritis, despite recent advancements in total ankle replacement. The objective of the present study was to retrospectively evaluate the radiographic and clinical fusion rates and time to bony fusion for patients who underwent ankle arthrodesis using an anterior approach with a single column locked plate construct versus crossed lag screws. We identified 358 patients who had undergone ankle arthrodesis from January 2003 to June 2013. Of the 358 patients, 83 (23.2%) met the inclusion criteria for the present study. Of the 83 included patients, 47 received locked anterior (or anterolateral) plate fixation, and 36 received crossed lag screw constructs. The overall nonunion rate was 6.0% (n = 5), with 1 nonunion in the anterior plate group (2.1%) and 4 nonunions in the crossed lag screw group (11.1%; p = .217). No differences were identified between the 2 groups for normal talocrural angle [χ2 (1) = 0.527; p = .468], normal tibial axis/talar ratio [χ2 (1) = 0.004; p = .952], and lateral dorsiflexion angle (p = .565). Based on our findings in similar demographic groups, ankle arthrodesis using locked anterior plate fixation is a safe technique with similar complication rates and radiographic outcomes to those of crossed lag screws.

Anterior Approach Total Ankle Arthroplasty: Superficial Peroneal Nerve Branches at Risk.

In ankle arthroplasty, little attention has been given to intraoperative nerve injury and its postoperative sequelae. The aim of the present anatomic study was to determine the relationship of the superficial peroneal nerve to the standard anterior approach for total ankle arthroplasty. The superficial peroneal nerve was dissected in 10 below-the-knee cadaver specimens. The medial and intermediate dorsal cutaneous branches were identified. A needle was placed at the ankle joint. The following measurements were recorded: bifurcation into the medial and intermediate dorsal cutaneous branches, reference needle to the branches of the medial and intermediate superficial peroneal nerve, and the crossing branches of the medial dorsal cutaneous nerve. Two specimens (20%) had a medial dorsal cutaneous branch cross from medially to laterally. Eight specimens (80%) had a crossing branch of the medial dorsal cutaneous branch within 5 cm of the incision. No intermediate dorsal cutaneous branches were within the incision. The results from the present cadaver study suggest that during an anterior ankle approach, aberrant branches of the superficial peroneal nerve could require transection in 20% of patients at the joint level and ≤80% of patients with distal extension >35 mm from the ankle joint. The risk of injury to branches of the superficial peroneal nerve is substantial. The risk of nerve injury can be decreased with meticulous operative technique, smaller incisions, and the avoidance of aggressive retraction.

Short-Term Radiographic Results and Technique of Tibiotalocalcaneal Arthrodesis With a Posterior Anatomic Locking Plate.

Tibiotalocalcaneal arthrodesis is a salvage procedure for severe hindfoot/ankle deformities, arthritis, avascular necrosis of the talus, failed total ankle replacement, and Charcot neuroarthropathy. The methods for fixation include anterior and lateral plates, screws, retrograde intramedullary nails, and external fixation. The purpose of the present report was to describe the short-term radiographic outcomes and technique using a posterior approach with an anatomic-specific locking plate for tibiotalocalcaneal arthrodesis. Nine patients underwent tibiotalocalcaneal arthrodesis using a posterior locking plate. The medical records and radiographs were retrospectively reviewed for patient demographics, fusion rate, complications, and patient satisfaction. The mean patient age was 57.89 ± 10.8 years, and the follow-up period was 11.11 ± 4.74 months for the patients undergoing posterior tibiotalocalcaneal arthrodesis. The mean time to weightbearing in a shoe with a brace was 16.68 weeks. The ankle and subtalar joints had healed within a mean duration of 13.61 ± 2.96 weeks. Two patients (22%) developed nonunion, 1 at both the ankle and subtalar joint and 1 at the ankle only. The present report demonstrates an alternative posterior approach to joint preparation and fixation. Direct visualization of both joints and soft tissue coverage provide a viable option for posterior fusion in patients with compromised anterior and/or lateral skin envelopes.

Posterior Ankle Structure Injury During Total Ankle Replacement.

Total ankle replacement studies have focused on reporting complications that are directly observed clinically or radiographically, including wound problems, technical errors, implant loosening, subsidence, infection, bone fractures, and heterotopic ossification. However, patients can still experience unresolved pain even when these problems have been ruled out. We initiated a study to more clearly define the relative risk of injury to the anatomic structures in the posterior ankle during total ankle replacement using a third-generation implant system. Ten fresh-frozen adult cadaveric below-the-knee specimens were positioned in the intraoperative positioning frame of an approved total ankle replacement system and adjusted to achieve proper foot alignment using fluoroscopic imaging. The relationship between the tibial cutting guide pins and the posterior neurovascular and tendon structures was measured using digital calipers. High rates of posterior structural injury were found. Nearly all proximal-medial pins encountered a posteromedial neurovascular structure, most commonly the tibial nerve. The distal-medial pins mainly encountered posteromedial tendinous structures, in particular, the flexor digitorum longus tendon. The proximal lateral pins were highly likely to encounter the Achilles tendon and the sural nerve. Our results support our hypothesis that the tibial neurovascular structures are at the greatest risk when preparing for and completing the bony resection, particularly with the medial and proximal cuts. Posterior ankle soft tissue structure injuries can occur during implantation but currently with unknown frequency and undetermined significance. Further study of posterior structural injuries could result in a more informed approach to post-total ankle replacement complications and management.

Intraoperative value of the thompson test.

The purpose of the present study was to assess the validity of the Thompson sign and determine whether the deep flexors of the foot can produce a falsely intact Achilles tendon.Ten unmatched above-the-knee lower extremity cadaveric specimens were studied. In group 1, the Achilles tendon was sectioned into 25% increments. The Thompson maneuver was performed after each sequential sectioning of the Achilles tendon, including after it had been completely sectioned. If the Thompson sign was still intact after complete release of the Achilles tendon, we proceeded to release the tendon, and tendon flexor hallucis longus, flexor digitorum longus, and posterior tibial tendons. The Thompson test was performed after the release of each tendon. In group 2, the tendon releases were performed in a reverse order to that of group 1, with the Thompson test performed after each release. In group 1, the Thompson sign remained intact in all specimens after sectioning of 25%, 50%, and 75% of the tendon. After complete (100%) release of the tendon, the Thompson sign was absent in all specimens. In group 2, the Thompson sign remained intact after sectioning of the posterior tibial, flexor digitorum longus, and flexor hallucis longus tendons in all specimens. The Thompson sign remained intact in all specimens after sectioning of 25%, 50%, and 75% of the Achilles tendon. After complete release of the tendon, the Thompson sign was absent in all specimens.The Thompson test is an accurate clinical test for diagnosing complete Achilles tendon ruptures. However, it might not be a useful test for diagnosing partial Achilles tendon ruptures. Our findings also call into question the usefulness of the Thompson test in the intraoperative setting.

Enhanced Lapidus arthrodesis: crossed screw technique with middle cuneiform fixation further reduces sagittal mobility.

Persistent medial column sagittal mobility can be encountered despite successful first tarsometatarsal stabilization if fixation has been limited to the first tarsometatarsal joint. The purpose of the present cadaveric research was to quantify the effect of a third point of fixation from the base of the first metatarsal to the middle cuneiform compared with the traditional isolated first tarsometatarsal fixation. Ten matched pairs of below-the-knee specimens, with a known cause of death, sex, ethnicity, and age, height, weight, and body mass index at death, were used for our examination. Portable fluoroscopy aided with the accurate placement of all points of fixation. Measurements of movement were obtained using the validated Klaue device. The 20 matched below-the-knee specimens were from 10 cadavers (2 female and 8 male donors, aged 72.8 ± 9.3 years, body mass index 21.1 ± 4.2 kg/m(2)). The sagittal plane motion of the first ray was 7.45 ± 1.82 mm before fixation. With isolated first tarsometatarsal fixation, the sagittal motion decreased to 4.41 ± 1.51 mm and decreased further to 3.12 ± 1.06 mm, with the addition of middle cuneiform fixation. Statistically significant enhancement of the stability of sagittal first ray motion was noted with the addition of the first metatarsal to middle cuneiform pin, even after simulated Lapidus fixation. Our findings suggest that first metatarsal to middle cuneiform fixation can be beneficial if excessive sagittal motion is present after standard 2-point fixation and can play a role in the prevention of recurrence and complications.

Medial double arthrodesis with lateral column sparing and arthrodiastasis: a radiographic and medical record review.

Correction of valgus hindfoot deformity can be successfully achieved with arthrodesis of the subtalar and talonavicular joints through a single medial based incision. The advantages of medial double arthrodesis compared with the standard triple arthrodesis 2-incision approach include the absence of a lateral incision and a few degrees of residual mobility through the unfused calcaneocuboid joint (CCJ). The CCJ has often been noted to distract and decompress with the abduction correction achieved through medial double fusion. The primary goal of the present retrospective study was to identify the frequency of CCJ decompression, measure the radiographic changes at the CCJ, and evaluate the flatfoot correction using this operative approach. A total of 46 patients (47 feet) were identified as possible subjects. Twenty patients (20 feet) with a mean follow-up period of 9.2 ± 4.1 (range 6 to 21) months met our inclusion criteria. Distraction of the CCJ using medial double fusion resulted in increased joint space and improvement of at least 1 grade of arthritis in 50% of the patients. In the patients with severe CCJ arthrosis, the improvement was less predictable, with only 20% showing radiographic improvement. Correction of flatfoot as measured on standard radiographs showed excellent results. Subchondral bone changes as measured by the CCJ arthrosis scale improved in patients with mild to moderate arthritis after distraction arthrodiastasis. However, those with severe preoperative CCJ had less predictable improvement. Medial double arthrodesis for severe flatfoot deformity provides predictable correction of the deformity and improvement in the CCJ arthritis scale when the preoperative arthritis of the CCJ is mild to moderate.

Quantification of Subtalar Posterior Facet Involvement During Intramedullary Guidance of Total Ankle Arthroplasty:A Cadaveric Study.

Total ankle arthroplasty is an evolving treatment of ankle arthritis. One implant uses intramedullary guidance to enhance accuracy by accessing the tibial canal through the inferior aspect of the foot, potentially placing the subtalar joint articulation at risk. The purpose of the present cadaveric anatomic evaluation was to identify posterior subtalar articular facet joint involvement during intramedullary guidance to the tibial canal. Ten below-the-knee cadaveric specimens were used. After drilling into the tibial medullary canal with a 6-mm drill bit and using the standard targeting jig, the specimens were dissected, and the posterior facet was evaluated. We graded posterior facet involvement according to the location of the drill hole and, if within the facet, the percentage of the facet violated by the drill bit, with 100% representing the full circumference of the 6-mm drill bit. Of the 8 specimens in which the drill bit passed through the subtalar posterior articular facet, the encroachment was peripheral in all cases, with no specimen showing circumferential 6-mm drill bit articular penetration (no cases with 100%). Sinus tarsi penetration occurred in 20% of the cases. The dissections with articular involvement included 3 specimens with >50% of the drill bit penetrating and 5 with <50%. The portion of the posterior facet involved among the specimens that were violated was anterocentral in the joint. A risk of damage to the posterior facet of the subtalar joint exists with intramedullary total ankle systems. Our study has demonstrated that the drill bit will involve the anterocentral and anterolateral portions of the posterior facet of the subtalar joint, with <6 mm articular disruption in all cases.

Effect of Osteogenic Progenitor Cell Concentration on the Incidence of Foot and Ankle Fusion.

The use of biologics, namely demineralized bone matrix, bone marrow aspirate (BMA), and other growth factors, has gained popularity in foot and ankle surgery for use in compromised hosts or high-risk situations. Our research has shown the concentration of these pluripotent cells was greatest in the iliac crest. A medical record and radiographic review was performed to compare the effect of BMA harvest site osteogenic progenitor cells on the incidence of fusion. Radiographs were reviewed for radiographic evidence of trabecular bridging in 2 or more views. If fusion occurred, the number of osteogenic progenitor cells found in the combined BMA at surgery was recorded. A total of 33 patients were included in the present study. Of the 33 patients, 32 (97.0%) had radiographic fusion at a mean of 13 ± 6 (range 8 to 30) weeks, and 1 (3.0%) experienced nonunion and required revision. The patient procedures were as follows: 18 (54.5%) hindfoot arthrodeses, 8 (24.2%) forefoot arthrodeses, 4 (12.1%) fractures, and 3 (9.1%) isolated ankle fusions. The mean colony-forming units for the patients with fusion was 20.3 ± 23.5 (range 0.0 to 107.0). In the patient with nonunion, it was 0.20 colony-forming unit. Our comparison of the incidence of fusion with the use of osteogenic progenitor cells from 3 anatomic sites showed a low incidence of complications and a high incidence of fusion. No association was found between the BMA concentration and the incidence of fusion, suggesting a minimum concentration and biologic potential of pluripotent cells is necessary to achieve the clinical effect of fusion.

Safety analysis of cryopreserved amniotic membrane/umbilical cord tissue in foot and ankle surgery: a consecutive case series of 124 patients.

Cryopreserved amnion tissues derived from amniotic membrane/umbilical cord (AM/UC) have been used extensively in ophthalmology for minimizing postoperative inflammation, pain, and adhesion formation following various surgical procedures. There is limited data in the current literature regarding the use of amnion tissue product in foot and ankle surgery. The purpose of this retrospective study is to report the short-term safety profile after in vivo application of cryopreserved AM/UC tissue use in foot and ankle surgery. A retrospective consecutive case series was performed for cases where amnion tissue was used with a minimum follow-up of 120 days between 2011 and 2012. The clinical outcomes of interest were postoperative infections, delayed or nonhealing wounds, adverse surgical site reactions, and repeat surgery for formal irrigation and debridement. One hundred twenty-four patients qualified for inclusion. Cryopreserved AM/UC tissue was introduced into the surgical wound and placed adjacent to the compromised and repaired tendons, most frequently in peroneal and Achilles tendon repairs. In this level IV consecutive case series cohort, there was an overall wound complication rate of 5.64%, with a re-operation rate of 1.6% (2/124). In each of these cases, patients had an irrigation and debridement with ultimate successful wound healing. The results of this study demonstrate that the use of amnion tissue in the foot and ankle setting is safe with a decreasing trend in overall complication rates compared with historically published norms.