Risks to the blood supply of the talus with four methods of total ankle arthroplasty: a cadaveric injection study

Association of Timing of Hindfoot Arthrodesis and Early Reoperation Rates for Total Ankle Arthroplasty

BACKGROUND

Prior literature has demonstrated that ipsilateral hindfoot arthrodesis may increase the risk for reoperation after total ankle arthroplasty (TAA) and that simultaneous hindfoot arthrodesis with TAA could result in short-term clinical and radiologic improvements. The purpose of this study is to compare the reoperation rates after TAA with prior hindfoot arthrodesis vs simultaneous arthrodesis and TAA.

METHODS

Patients who underwent primary TAA were identified in the PearlDiver database. Patients were sorted into 2 study cohorts: hindfoot arthrodesis prior to TAA and simultaneous arthrodesis and TAA. Propensity matched control cohorts were identified for each study group. Multivariate analysis was conducted to account for any confounding variables and covariates when identifying differences in complications between cohorts.

RESULTS

297 patients underwent TAA with prior hindfoot arthrodesis and 174 underwent TAA and hindfoot arthrodesis concurrently. The incidence of reoperation (13.8% vs 5.2%, P < .001) and infection (12.6% vs 5.9%, P = .011) for the simultaneous cohort was higher when compared to the matched control cohort. In contrast, there was no statistically significant difference when comparing the prior arthrodesis cohort to the matched control cohort in reoperation rates (5.1% vs 4.7%, P = .787) or infection rates (4.4% vs 4.8%, P = .734). Those undergoing simultaneous procedures had increased incidences of reoperation, wound complications, infection, and emergency department visits (P < .0167) when compared to the TAA with prior arthrodesis cohort.

CONCLUSION

Patients undergoing TAA and hindfoot arthrodesis concurrently were found to have higher rates of reoperation and infection when compared to the matched control cohort . In contrast, there was no difference in these rates in patients undergoing TAA with prior hindfoot arthrodesis compared with their matched control cohort. Patients undergoing simultaneous procedures had increased rates of reoperations, wound complications, infection, and emergency department visits compared to the TAA with prior arthrodesis cohort.

Comparison of Radiographic Talar Loosening Rates Between Salto-Talaris and INBONE II

BACKGROUND

Despite substantial increase in total ankle arthroplasty (TAA) nationwide, there are few studies comparing flat-cut vs chamfer-cut talar systems in TAA with regard to radiographic aseptic loosening rates of the implant.

METHODS

This retrospective study included 189 Salto-Talaris TAA and 132 INBONE II primary TAA with a minimum 1-year follow-up. Patient characteristics were obtained including gender, age at surgery, body mass index (BMI), smoking status, primary diagnosis, surgical time, and the presence of diabetes. Radiographic evidence for aseptic loosening was assessed. Statistical analysis was performed for comparison in outcomes between Salto-Talaris and INBONE II.

RESULTS

The mean age of the study population was 63.5 ± 9.8 years at surgery. Mean follow-up was 4.9 ± 3.0 years. Radiographic aseptic loosening of the tibial implant showed no significant difference between the 2 groups: Salto-Talaris, 18%, and INBONE II, 18.9% (P = .829). Aseptic loosening of the talar implant also showed no significant difference between the 2 groups: Salto-Talaris, 1.6%, and INBONE II, 1.5% (P = .959). No variables, including the implant type, were found to contribute to the aseptic loosening rate of either the tibia or talus.

CONCLUSION

In our cohort, we observed no difference in radiographic implant aseptic loosening between Salto-Talaris and INBONE II systems.

LEVEL OF EVIDENCE

Level IV, retrospective case series study.

Posteromedial structure protection during ankle replacement: Surgical technique

Residual pain after ankle replacement may implicate lesions in posteromedial structures, including the posterior tibial pedicle and tendon. The technique described here protects these structures, by positioning a malleable plate via a medial retromalleolar counter-approach. The technique seems not to cause any specific iatrogenicity. We advocate systematic implementation of this kind of protection in ankle replacement surgery. LEVEL OF EVIDENCE: IV, retrospective study.

Multimodal Microvascular Mapping for Head and Neck, Skull Base Research and Education: An Anatomical Donor Study

Objective This study was aimed to develop a method combining computed tomography (CT) and fluorescence imaging, allowing identification of microvasculature in anatomical donors and facilitating translational research and education.

Methods We investigated homogeneity and radiopacity of 30 different mixtures including radiopaque substances povidone–iodine (Betadine), barium sulfate (BaSO4), and bismuth subsalicylate (Pepto-Bismol) varying in suspension and dilution with agar, latex, or gelatin. Three candidate mixtures were selected for testing the extent of perfusion in renal vasculature to establish methodology. From these candidate mixtures, two were selected for mixture with fluorescein and infusion into cadavers based on their ability to perfuse renal vasculature. The extent to which these two candidate mixtures combined with fluorescein were able to perfuse vasculature in a cadaver head was used to determine which mixture was superior.

Results BaSO4 and bismuth subsalicylate–based mixtures demonstrated superior opacity in vials. In terms of solidifying agents, gelatin-based mixtures demonstrated increased friability and lower melting points compared with the other agents, so only latex and agar-based mixtures were used moving forward past the vial stage. Combinations of BaSO4 and latex and BaSO4 and 3% agar were found to perfuse kidneys superiorly to the mixture containing bismuth subsalicylate. Finally, in cadaver heads, the mixture containing BaSO4, agar, and fluorescein was found to perfuse the smallest vasculature.

Conclusion A final combination of BaSO4, 3% agar, and fluorescein proves to be a powerful and novel combination enabling CT imaging, fluorescence imaging, and dissection of vasculature. This paves the way for future translational research and education.

Midterm Survivorship of the INBONE II Total Ankle Arthroplasty

BACKGROUND

The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. Although outcomes of the INBONE I have been published, there is limited midterm survival data for the INBONE II. The purpose of this study was to determine the radiographic and patient-reported outcomes, and survivorship of this prosthesis in patients with a minimum 5-year follow-up.

METHODS

We retrospectively identified 51 ankles (46 patients) from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases had minimum clinical follow-up of 5 years (mean, 6.4; range 5-9). Median age was 66 years (range 42-81) and median BMI was 27.5 (range 20.1-33.0). A chart review was performed to record the incidence of revision and reoperation. Preoperative and postoperative radiographs were analyzed to assess the coronal tibiotalar alignment (TTA), the talar inclination angle, and the presence of periprosthetic lucencies and cyst formation. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared. Survivorship was determined by incidence of revision, defined as removal of a metallic component.

RESULTS

The survivorship at 5 years was 98% and the rate of reoperation was 7.8% (n = 4); 2 patients underwent irrigation and debridement for infection, 1 patient underwent a medializing calcaneal osteotomy, and 1 patient underwent open gutter debridement, 1 patient underwent a revision of a subsided talar component at 3.2 years after index surgery. Average postoperative TTA was 88.6 degrees, with 42 rated as neutral (85-95 degrees), 2 varus (<85 degrees), and no valgus (>95 degrees) ankles. At final follow-up, asymptomatic periprosthetic cysts were observed in 8 patients. All FAOS domain scores improved between preoperative and final follow-up.

CONCLUSION

At midterm follow-up, we observed significant improvement in radiographic alignment and patient-reported outcome scores for the INBONE II total ankle prosthesis. In addition, this cohort has had a relatively low reoperation rate and high survivorship.

LEVEL OF EVIDENCE

Level IV, case series.

Low Rate of Peri-implant Osteolysis in Trabecular Metal Total Ankle Replacement on Short- to Midterm Follow-up

BACKGROUND

Peri-implant osteolysis is one of the major complications related to total ankle replacement. The aim of this study was to investigate the short- to midterm incidence of peri-implant osteolysis using computed tomography (CT) as imaging method for the Trabecular Metal Total Ankle (TMTA) implant representing a novel total ankle replacement (TAR) implant design regarding material and surgical technique.

METHODS

In total, 104 consecutive patients who had a primary TMTA replacement between March 2013 and October 2017 were included in the study. The radiographic evaluation included weightbearing anteroposterior and lateral views at baseline and after 3, 6, and every 12 months postoperatively. A helical CT was undertaken preoperatively and of the 80 patients available to follow up at least 12 months postoperatively, with average time interval between the TAR operation and the latest CT of 39 (range, 12-85) months.

RESULTS

Eight of 80 patients had altogether 11 osteolytic lesions around the components on CT images. Seven lesions were found in tibia, 3 in talus, and 1 in distal fibula. Four of the tibial lesions were situated in the medial malleolus and were not in contact with the prosthesis component. The sizes of the osteolytic lesions ranged between 7 and 20 mm, and the average volume of the lesions was 689 mm³.

CONCLUSION

We conclude that the risk of peri-implant osteolysis with the TMTA implant is minimal in short to midterm. The anatomic configuration, unique material, and surgical technique may all contribute to the TMTA implant having a low rate of peri-implant osteolysis.

LEVEL OF EVIDENCE

Level IV, case series.

Finite-element analysis of the influence of tibial implant fixation design of total ankle replacement on bone-implant interfacial biomechanical performance

PURPOSE

Implant loosening in tibia after primary total ankle replacement (TAR) is one of the common postoperative problems in TAR. Innovations in implant structure design may ideally reduce micromotion at the bone-implant interface and enhance the bone-implant fixation and initial stability, thus eventually prevents long-term implant loosening. This study aimed to investigate (1) biomechanical characteristics at the bone-implant interface and (2) the influence of design features, such as radius, height, and length.

METHODS

A total of 101 finite-element models were created based on four commercially available implants. The models predicted micromotion at the bone-implant interface, and we investigated the impact of structural parameters, such as radius, length, and height.

RESULTS

Our results suggested that stem-type implants generally required the highest volume of bone resection before implantation, while peg-type implants required the lowest. Compared with central fixation features (stem and keel), peripherally distributed geometries (bar and peg) were associated with lower initial micromotions. The initial stability of all types of implant design can be optimized by decreasing fixation size, such as reducing the radius of the bars and pegs and lowering the height.

CONCLUSION

Peg-type tibial implant design may be a promising fixation method, which is required with a minimum bone resection volume and yielded minimum micromotion under an extreme axial loading scenario. Present models can serve as a useful platform to build upon to help physicians or engineers when making incremental improvements related to implant design.

Intermediate-Term Outcomes of a Third-Generation, 2-Component Total Ankle Prosthesis

BACKGROUND

Short-term outcomes for the INBONE I and INBONE II tibial stems have been favorable. The INBONE-II talus has been shown to have lower reoperation and failure rates compared to its predecessor at short term follow-up. The purpose of the present study was to assess mid-term outcomes for the third generation, two component total ankle prosthesis at 5 to 9 years follow-up, evaluating both the tibial and talar components.

METHODS

All patients who underwent primary total ankle arthroplasty (TAA) with INBONE-II between July 2010 and July 2014 at a single institution and who were at least 5 years postoperative were included. A total of 15 ankles with a mean follow-up of 85 months (range, 61-113 months) met the criteria. Radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 weeks postoperatively, and at the most recent follow-up. Medical records were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively.

RESULTS

The survivorship of the prosthesis at a mean of 85 months was 93.7%. The coronal and sagittal tibiotalar alignments 6 weeks after surgery were 2.1 degrees (P = .081) and 36% (P = .15), respectively. Maintenance of this alignment was observed during the latest follow-up (P = .684 and P = .837, respectively). One ankle (6.7%) required early component revision, while 4 (26.7%) required a non-implant-related revision. Six complications (2 high grade, 1 intermediate, and 3 low) in 5 ankles (33.3%) were recorded according to the Glazebrook classification system.

CONCLUSION

The present study is the first to report midterm follow-up after TAA with this third-generation, 2-component prothesis. High survivorship, maintenance of correction, and a low incidence of major complications were observed in this small case series. The most common complication overall was lateral gutter impingement, which accounted for the majority of the nonrevisional reoperations.

LEVEL OF EVIDENCE

Level IV, case series.

Protective Approach for Anatomical Structures at Risk in Total Ankle Replacement

Currently, total ankle replacement (TAR) is an alternative to arthrodesis in selected patients, with the anterior approach being the most widely used to carry it out. Regardless of the type of implant used, the pins for bone resection guides, chisels, and the saw for distal tibial resection can endanger the neurovascular and tendon structures that lie in intimate proximity to the posterior aspect of the ankle. Additionally, there is a documented complication rate of up to 15.3% in such surgery. We have implemented a protective posteromedial approach that complements the anterior approach to reduce this risk of intraoperative iatrogenic injury. Using this method we introduce a protective instrument that separates the posterior anatomical structures from the posterior cortex of the tibia. This article describes the surgical technique used to carry out TAR through an anterior approach in a safer way, without increasing complications or the duration of real-time surgery.

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.

Graphic Representation of Intraosseous and Extraosseous Talus Blood Supply. Illustrated Anatomy

BACKGROUND

The vascular anatomy of the talus attracts intense research being not always easy to understand. The high intraosseous variability together with the anatomical characteristics makes some areas of the talus more prone to vascular compromise. The aim of this study is to describe the vascularization of the talus, both intraosseous and extraosseous.

MATERIAL AND METHODS

From the literature reviewed, we have developed a graphic scheme that allows easy observation of the irrigation distribution. To this end, nineteen anatomical dissections of human cadaveric feet have been carried out. Fifteen fresh-frozen slices have been cut in different planes and prepared using the modified Spalteholz technique and latex injection with blue and black ink to visualize the vascular network. In addition, the study has been complemented with a comprehensive literature review on this subject.

RESULTS

The findings allowed us to conclude that the posterior tibial artery provides the most important blood supply to the neck and body of the talus through the tarsal canal artery and the deltoid branch. The anterior tibial artery splits in the dorsal pedis artery, for the head and neck, and the lateral tarsal artery which throughout anastomoses breeds the tarsal sinus artery. The perforating peroneal artery branches out from the peroneal artery, creating an intraosseous anastomosis for the body and the posterior process.

CONCLUSION

The results obtained have contributed to develop a graphical representation that we present in this study, which allows a simple understanding of the intraosseus and extraosseus vascularization of the talus.

Clinical Use of Talar Prostheses

»

The blood supply to the talus is vulnerable to damage, making the talus susceptible to osteonecrosis, with limited treatment options.

»

Talar bone replacement has been investigated as a treatment option to preserve ankle function and maintain limb length.

»

Successful talar bone replacements have been performed for the past >35 years, with variations in design, methods of fixation, materials, and manufacturing techniques.

»

The designs of talar prostheses range from custom-made partial (talar body) or total prostheses to prefabricated universal (non-custom-made) prostheses.

»

Total talar prostheses have been demonstrated to function better than partial talar prostheses; however, there is a need for long-term studies regarding custom-made total talar prostheses and prefabricated universal talar prostheses in order to determine their long-term effectiveness.

State of the Art in Treatment of Chronic Medial Ankle Instability

Chronic deltoid instability (CDI), or medial ankle instability, can happen following traumas of the foot and ankle, predominantly rotational injuries. CDI is frequently underdiagnosed or misdiagnosed. Long-term residual instability can lead to ankle posttraumatic arthritis. Adequate assessment of patients with suspected CDI is paramount. Conservative treatment can be tried for stable or mildly unstable cases, but surgical treatment is usually needed for the more severely unstable patients, or when conservative measures fail. Few reconstruction techniques have been proposed in the setting of posttraumatic CDI. This article describes our preferred technique for reconstruction of the deep components of the deltoid ligament.

Adverse events related to total ankle replacement devices: an analysis of reports to the United States Food and Drug Administration

Background

The published outcomes of total ankle replacement (TAR) implants came from limited institutions creating observational bias. For broader perspective, we queried the Food and Drug Administration’s (FDA) Manufacturer and User Facility Device Experience (MAUDE) voluntary database to explore complications reported outside published literature.

Methods

The database was reviewed retrospectively between November 2011 and April 2019 using two product codes assigned to six TAR devices.

Results

Among 648 relevant reports available in the database, common complications were aseptic loosening (19.3%), infection (18.2%), and alignment/mechanical issues (16.5%). Others included instrument/instrumentation complications, impingement, polyethylene problems, fractures, avascular necrosis of talus (AVN), and packaging issues.

Conclusion

MAUDE database revealed various patterns of device-related malfunctions that have been under-reported in published data. Despite inconsistency in the available reports, it provided opportunities for improvements in quality control, device design, and ultimately patient safety. Database would be further strengthened by more robust reporting mechanism or mandatory reporting of device-related complications.

Positive and negative factors for the treatment outcomes following total ankle arthroplasty? A systematic review

BACKGROUND

Patient selection, surgeon's experience and implant design play an integral role and affect the treatment outcomes of total ankle arthroplasty (TAA). The aims of this study were to investigate the positive and negative attributes that correlate with different clinical and radiographic outcomes.

METHODS

Eight-nine studies matched the inclusion criteria: (1) studies of primary TAA with uncemented prosthesis; (2) mean follow-up of no less than 2-year; (3) reports of clinical and radiographic outcomes, and exclusion criteria: (1) non-English study; (2) more than one type of prosthesis without separated data; (3) kin studies with shorter follow-up or smaller cohort. Age, etiology, preoperative deformity, surgeon's experience, follow-up duration and prosthetic type were studied with respect to different outcomes by mixed-effects logistic regression analysis.

RESULTS

Patients factor: older patients reported less pain or stiffness and demonstrated less radiographic loosening which did not require additional surgical intervention. More traumatic arthritis experienced adjacent joints degeneration after TAA. Surgeon factor: less experienced surgeons had more intraoperative complications. Lack of experience for complications management without implant retrieval during early period might result in more revisions or fusion was done. Prosthetic factor: updated instrumentation decreased malalignment. If the polyethylene (PE) insert was significantly narrower than the metal components more implant instability and subsequent severe particulate wear was seen. Designs with flat-on-flat articulation and ridge at the center of the talar component associated with more PE fracture. Minimal bone resection reduced postoperative fractures. A flat cut of the tibial component and a flat undersurface with press-fit by two screws or pegs of the talar component demonstrated less postoperative fractures, whereas a syndesmosis fusion and a small triangular shape with one central fin of the talar component experienced more loosening which did not require additional surgery. Anatomic conical shape of the talar component seemed to reduce adjacent joint degeneration. Finally, fewer failures were found in patients who received HINTEGRA and Salto Talaris.

CONCLUSIONS

Based on our investigation, some positive and negative factors for different clinical and radiographic outcomes were found, which should be taken into consideration in clinical practice and ankle implant design.

Imaging of Bone Perfusion and Metabolism in Subjects Undergoing Total Ankle Arthroplasty Using 18F-Fluoride Positron Emission Tomography

BACKGROUND

Total ankle arthroplasty (TAA) continues to exhibit a relatively high incidence of complications and need for revision surgery compared to knee and hip arthroplasty. One common mode of failure in TAA is talar component subsidence. This may be caused by disruption in the talar blood supply related to the operative technique. The purpose of this study was to quantify changes in talar bone perfusion and turnover before and after TAA with the INBONE II system using ¹⁸F-fluoride positron emission tomography / computed tomography (PET/CT).

METHODS

Nine subjects (5 M/4 F) aged 68.9 ± 8.2 years were enrolled for ¹⁸F-fluoride PET/CT imaging before and 3 months after TAA. Regions of interest (ROI) were placed on the postoperative CT images in the body of the talus beneath the talar component and overlaid on the fused static PET images. Standard uptake values (SUVs) along with dynamic K₁ (bone blood flow) and k_i (bone metabolism or osteoblastic turnover) were calculated.

RESULTS

The SUV underneath the talar component compared to that measured at baseline before surgery was 1.93 ± 0.29 preoperatively vs 2.47 ± 0.37 postoperatively (P > .05). K₁ was 0.84 ± 0.16 mL/min/mL preoperatively vs 1.51 ± 0.23 mL/min/mL postoperatively (P = .026). k_i was constant at 0.09 ± 0.03 mL/min/mL preoperatively vs 0.12 ± 0.03 mL/min/mL postoperatively (P > .05).

CONCLUSION

Our study was the first to link ¹⁸F-fluoride PET/CT with pre-post evaluation of total ankle replacements. The study quantified perfusion within the talus beneath the TAA implant supporting the hypothesis that perfusion of the talus remained intact after surgery.

LEVEL OF EVIDENCE

Level II, prospective cohort study with development of diagnostic criteria.

A Modification of the Fibular Osteotomy for Total Ankle Replacement Through the Lateral Transfibular Approach

BACKGROUND

One disadvantage of lateral transfibular total ankle arthroplasty is the rate of symptoms related to the implant and wound issues requiring implant removal in association with the traditional fibular osteotomy. In the present study, lateral total ankle arthroplasty involving the traditional short oblique fibular osteotomy was compared with arthroplasty involving a long oblique osteotomy (the Foot & Ankle Reconstruction Group osteotomy).

METHODS

We retrospectively reviewed all primary lateral total ankle arthroplasties that had been performed by a single surgeon from May 2013 to October 2016 and had a minimum of 2 years of follow-up. Clinical assessment included patient demographics, wound complications, the need for implant removal, the pain score on a visual analog scale, the American Orthopaedic Foot & Ankle Society score, and the Short Form-12 Mental and Physical Component Summary scores. Weight-bearing radiographs were used to assess tibiotalar alignment, implant alignment, and fibular osteotomy healing.

RESULTS

One hundred and fifty-nine total ankle arthroplasties were identified. The traditional short fibular osteotomy was used in 50 ankles, and the long oblique osteotomy was used in 109. The rate of survival of the tibial and talar components of the ankle replacements was 100%, and there were no osteotomy nonunions. There was improvement in all clinical parameters, with no significant difference between the 2 groups. Radiographs showed excellent arthroplasty alignment at all time points, with no significant difference between the groups. There was a significant difference in the rates of wound dehiscence (p = 0.011) and fibular implant removal (p < 0.0001), with the long oblique osteotomy having lower rates of both (2.8% and 2.8%, respectively) compared with the short oblique osteotomy (14% and 28%, respectively).

CONCLUSIONS

In total ankle arthroplasty, modification of the traditional short oblique fibular osteotomy to a long oblique configuration provided excellent 2-year survival rates with good clinical and radiographic outcomes and decreased rates of wound complications and symptoms related to the fibular implant.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Two-Stage Varus Correction

Coronal plane deformity following total ankle arthroplasty has been associated with poor clinical outcomes and early prosthesis failure. Neutral mechanical alignment and prosthetic joint stability must be achieved through meticulous surgical planning and precise technical execution. Cavovarus foot deformity and varus malalignment of the lower extremity is reviewed, with particular emphasis as it relates to total ankle arthroplasty. Correction of varus malalignment may be performed at the time of total ankle arthroplasty or as a 2-stage procedure. Surgeon experience, revision total ankle arthroplasty, and subtalar arthrodesis should be considerations when contemplating 2-stage varus correction.

Therapeutic Efficacy Analysis of Talar Fracture Internal Fixation with Lateral Malleolar Osteotomy

Background

There are many surgical treatment approaches for talar fractures. However, due to the unique anatomical and blood supply characteristics of the talus, the traditional approaches tend to lead to blood supply damage. In order to best preserve the blood supply of the talus, we proposed a surgical approach of internal fixation of the talar fracture with lateral malleolar osteotomy and analyzed its efficacy.

Material/Methods

Twenty-six patients with talar fractures underwent open reduction surgery between January 2010 and December 2016. Following the lateral malleolar osteotomy, the talus was fully exposed. After anatomical reduction, the talus was fixed with 2 screws, and the lateral malleolus was fixed with distending wires. The treatment effects were assessed in the follow-up.

Results

All patients were followed for 7 to 22 months, for an average of 14.34 months. According to the Maryland Foot Score, 19 cases were excellent (90–100 points), 4 cases were good (85–90 points), and 3 cases were moderate (50–74 points).

Conclusions

Internal fixation of talar fractures with lateral malleolar osteotomy is a viable surgical approach to reduce injury to blood supply and maximize surgical exposure.

Early clinical and radiological evaluation in patients with total ankle replacement performed by lateral approach and peroneal osteotomy

BACKGROUND

The Zimmer Trabecular Metal Total Ankle Replacement (Zimmer TM TAR) is a recent ankle arthroplasty approved for use in the United States and Europe. Many of the studies reporting the results of this implant are provided by surgeons involved at least in the initial design of the implant under study. The aim of this study is to describe the early clinical and radiological outcomes in patients who underwent this procedure performed by non-designer surgeons.

METHODS

A total of thirty consecutive patients underwent total ankle replacement with a Zimmer TM TAR surgery between July 2013 to January 2016.All clinical assessments were collected pre- and post-operatively with minimum follow-up of 12 months for each patient using the American Orthopedic Foot and Ankle (AOFAS) score, the Foot Function Index (FFI) and a visual analogue scale (VAS) for pain. Radiographic outcomes included ankle orientation assessed with angle "α","β" and "γ" according to Wood. Furthermore, the anteroposterior offset ratio was measured in weight-bearing lateral ankle radiographs at the last follow-up.

RESULTS

The mean preoperative FFI-pain (FFI-P) value was 53.67, the FFI-disability (FFI-D) was 64.19. At the last follow-up visit, the FFI-P and FFI-D was 16.95 and 20.76 respectively (p<0.01 for the both scales). Preoperatively, the mean VAS for pain and AOFAS score was 7.81 and 40.95 respectively, and at the last follow-up 2.29 and 86.38 (p<0.01 for the both scales). The mean angle calculated using Wood and Deakin's method were "α"= 89.02°, "β"= 85.11 and "γ"= 27.54 post-operatively. At the last follow-up the same values were respectively 89.43, 85.18 and 29.94. At the last follow-up, the mean offset ratio was 0.06 (range 0.003/-0.17).

CONCLUSIONS

These early results show high levels of patient satisfaction, and we are encouraged to continue with lateral approach total ankle arthroplasty.

Revision Surgery for Metal Component Failure in Total Ankle Arthroplasty

Background:

Metal component failure in total ankle arthroplasty (TAA) is difficult to treat. Traditionally, conversion to an arthrodesis has been advocated. Revision TAA surgery has become more common with availability of revision implants and refinement of bone-conserving primary implants. The goal of this study was to analyze the clinical results and patient-reported outcomes for patients undergoing revision total ankle arthroplasty.

Methods:

We retrospectively reviewed prospectively collected data on 52 patients with a mean age of 63.5 ± 9.6 years who had developed loosening or collapse of major metal components following primary TAA. These patients were compared to a case-matched control group of 52 primary TAAs performed at the host institution with a minimum of 2 years’ follow-up. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, Short Form 36 (SF-36), Short Musculoskeletal Function Assessment (SMFA), and pain scores were prospectively collected. Clinical data was collected through review of the electronic medical record to identify reasons for clinical failure, where clinical failure was defined as second revision or conversion to arthrodesis or amputation.

Results:

The identified causes of failure of primary TAA were aseptic loosening of both components (42%), talar component subsidence/loosening (36%), coronal talar subluxation (12%), tibial loosening (8%), and talar malrotation (2%). Thirty-one patients (59.5%) underwent revision of all components, 20 (38.5%) just the talar and polyethylene components, and one (2%) the tibial and polyethylene components. The average time to revision was 5.5 years ± 5.4 with a follow-up of 3.1 years ± 1.5 after revision. Eleven (21.2%) revision arthroplasties required further surgery: 6 required conversion to arthrodesis and 5 required second revision TAA. Pain scores, SF-36 scores, SMFA scores, and AOFAS Hindfoot scores all improved after revision surgery but never reached the same degree of improvement seen after primary TAA.

Conclusions:

Clinical and patient-reported outcomes of revision ankle arthroplasty after metal component failure significantly improved after surgery, although the recovery time was longer. In this series, 21.2% of revision TAAs required a second revision TAA or arthrodesis surgery. Various prostheses performed similarly when used for revision surgery. Revision TAA can offer significant improvements postoperatively.

Level of Evidence:

Level III, therapeutic.

Risk Factors for Failure of Total Ankle Arthroplasty With a Minimum Five Years of Follow-up

BACKGROUND:

As the popularity of total ankle arthroplasty (TAA) increases and indications expand, surgeons require a better understanding of which patient factors are associated with implant failure. In this study, we aimed to use a large total ankle database to identify independent risk factors for implant failure at mid- to long-term follow-up.

METHODS:

A prospectively collected database was used to identify all patients who underwent primary TAA with a minimum 5 years' follow-up. The primary outcome was revision, defined as removal of one or both metal components; failures due to infection were excluded. Patient and clinical factors analyzed included age, sex, body mass index (BMI), smoking status, presence of diabetes, indication for TAA, implant, tourniquet time, and presence of ipsilateral hindfoot fusion. Preoperative coronal deformity and sagittal talar translation were assessed, as were postoperative coronal and sagittal tibial component alignment. Univariable and multivariable analyses were performed to identify predictors of implant failure. After excluding 5 ankles that failed because of deep infection, 533 ankles with a mean 7 (range, 5-11) years of follow-up met the inclusion criteria. Four implants were used: INBONE I, INBONE II, STAR, and Salto-Talaris.

RESULTS:

Thirty-four ankles (6.4%) were revised or removed a mean 4 (range, 1-9) years postoperatively. The only independent predictors of failure were the INBONE I prosthesis and ipsilateral hindfoot fusion ( P = .006 and P = .023, respectively).

CONCLUSIONS:

This is among the largest studies to analyze the relationship between TAA failure rates and multiple different patient, operative, and radiographic factors. Of note, age, BMI, and amount of deformity were not associated with higher failure rates. Only patients with ipsilateral hindfoot fusion or who received the INBONE I prosthesis were at significantly higher risk of implant failure.

LEVEL OF EVIDENCE:

Level III, retrospective cohort study.

Hindfoot Arthrodesis Screw Position and Trajectory Effect on Talus Subsidence When Performed With Total Ankle Arthroplasty

BACKGROUND:

Total ankle arthroplasty (TAA) is increasingly being recognized as an effective surgical option for end-stage ankle arthritis. Associated hindfoot arthrodesis procedures are at times needed to correct malalignment or to address adjacent joint arthritis. Results following TAA and associated hindfoot arthrodesis have at times been underwhelming and the devascularization of the talar blood supply has been postulated as a potential cause. This study explored the association between hindfoot arthrodesis fixation and talar component subsidence.

METHODS:

The study included 81 consecutive patients who underwent a TAA with either an isolated subtalar arthrodesis or combined subtalar and talonavicular arthrodesis with a minimum of 2 years of follow-up. Radiographic and clinical evaluations including patient-reported outcomes were performed at each postoperative visit. The primary outcome measure was the presence of talar component subsidence while patient-reported outcomes were the secondary outcome measure.

RESULTS:

30.9% of patients had evidence of talar component subsidence. Subsidence was seen in 55.5% of patients with dorsal to plantar subtalar fixation compared to 11.1% of patients with plantar to dorsal screws ( P < .001) and in 44.4% of patients with screws violating the sinus tarsi compared to 3.7% of patients without screws in the sinus tarsi ( P < .001). Screws that were placed from dorsal to plantar were more likely to violate the sinus tarsi ( P < .001). Patients with evidence of talar subsidence reported higher pain scores and lower functional scores. There were 8 TAA failures, and the presence of dorsal to plantar screws was associated with failure ( P < .01).

CONCLUSION:

Screws that are placed across the subtalar joint from a dorsal to plantar approach are more likely to violate the sinus tarsi, contributing to a significantly higher rate of talar component subsidence when associated with TAA.

LEVEL OF EVIDENCE:

Level II, prospective comparative series.

Patient-Reported Outcomes Before and After Primary and Revision Total Ankle Arthroplasty

BACKGROUND:

Studies examining the clinical outcomes of revision total ankle arthroplasty (TAA) are sparse. Revision TAA surgery has become more common with availability of revision implants and refinement of bone-conserving primary implants. In this study, patient-reported results and clinical outcomes were analyzed for a cohort of patients who underwent both primary and revision TAA at a single high-volume institution.

METHODS:

We retrospectively reviewed prospectively collected data on 29 patients with failed primary total ankle arthroplasty. Cases of isolated polyethylene exchange, infection, or extra-articular realignment procedures were excluded. Patient-reported outcome (PRO) measures and clinical results were reviewed in this longitudinal study.

RESULTS:

Fifteen patients (51.7%) underwent revision of just the talar and polyethylene components while 13 patients (44.8%) underwent revision of all components. The most common cause was talar subsidence (51.7%). The average time to revision was 3.9 years with a follow-up of 3.2 years after revision, and 3 (10.3%) revision arthroplasties required further surgery; 2 required conversion to arthrodesis and 1 required second revision TAA. Improvements in PROs were better after primary than revision TAA.

CONCLUSIONS:

Clinical and patient-reported results of revision ankle arthroplasty after metal component failure improved significantly but never reached the improvements seen after primary ankle arthroplasty. In our series, 10.3% of revision TAAs required a second revision TAA or arthrodesis surgery.

LEVELS OF EVIDENCE:

Therapeutic Level III, comparative series.

3D Printed Total Talar Replacement: A Promising Treatment Option for Advanced Arthritis, Avascular Osteonecrosis, and Osteomyelitis of the Ankle

Advanced ankle arthritis, avascular osteonecrosis, and osteomyelitis of the ankle remain a surgical challenge in the foot and ankle arena with limited treatment options. Multiple medical comorbidities contribute to total loss of the talus. Collapse of the talar body as a complication of total ankle arthroplasty, talectomy in infection, and septic talus necrosis or severe bone defects caused by tumor resection may result in need for total talar replacement. Ankle arthrodesis and tibiocalcaneal fusion after talectomy can produce severe disability of the ankle and foot. Total ankle replacement is a viable option for treatment of end-stage ankle arthritis in appropriate patient populations.

Perioperative Complications and Initial Alignment of Lateral Approach Total Ankle Arthroplasty

Total ankle replacement continues to become a more common treatment of end-stage ankle arthritis. A lateral approach total ankle implant system is an innovative approach for this treatment. We performed a retrospective review of 16 patients treated with lateral approach total ankle replacement. The implant was successful and retained in all cases during a follow-up period of 769 ± 221.3 days (25.3 ± 7.3 months). Initial satisfactory alignment was achieved in all cases. For patients in whom a frontal plane incongruent deformity was present preoperatively, a statistically significant correction was obtained (p = .0122). Three cases of delayed or nonunion of the fibula (18.8%) occurred, and one case of infection that led to removal of the fibular plate developed, for a total of 4 complications (25.0%) related to the fibular osteotomy. Our findings indicate that lateral approach total ankle replacement is effective with unique advantages and disadvantages for treating end-stage ankle arthritis.

Design Rationale for Total Ankle Arthroplasty Systems: An Update

The design of total ankle arthroplasty systems is evolving as a result of findings from longer-term studies. Our understanding of modes of failure has increased, and surgical techniques have become more refined. Currently, five total ankle arthroplasty systems are used in the United States. The landscape has changed considerably in the decade since the latest article reviewing total ankle design was published. Some implants with acceptable intermediate results had much poorer outcomes at 7- to 10-year follow-up. As more research showing mid- to long-term outcomes is published, the design rationale and current outcomes data for each of these implants must be considered.

Early Clinical and Radiographic Outcomes of Trabecular Metal Total Ankle Replacement Using a Transfibular Approach

BACKGROUND

In the last 2 decades, total ankle replacement has gained greater acceptance as a treatment option in patients with end-stage ankle osteoarthritis. However, there is a lack of literature on total ankle replacement using a lateral transfibular approach. Therefore, we sought to report early clinical and radiographic results for a patient cohort treated with total ankle replacement using a lateral transfibular approach, performed by a single surgeon.

METHODS

From October 2012 to December 2014, 55 primary total ankle arthroplasties using the Zimmer Trabecular Metal Total Ankle implant were performed in 54 patients (29 male and 25 female; mean age, 67.0 years). Clinical assessment, including pain evaluation and measurement of ankle range of motion, was conducted preoperatively and at the latest follow-up. Weight-bearing radiographs were used to determine angular alignment of the tibial and talar components and to analyze the bone-implant interface. Intraoperative and postoperative complications, revision surgeries, and survivorship were evaluated.

RESULTS

Implant survival was 93% at 24 months of follow-up. There were 3 revisions of a tibial component due to aseptic loosening. In 10 of the 55 cases, a secondary procedure was performed during follow-up. The mean follow-up duration was 26.6 ± 4.2 months. No delayed union or nonunion was observed for fibular healing. The average visual analog scale (VAS) pain score decreased significantly, from 7.9 ± 1.3 to 0.8 ± 1.2. The average total range of motion increased significantly, from 22.9° ± 12.7° to 40.2° ± 11.8°.

CONCLUSIONS

Early results of total ankle replacement using the Zimmer trabecular metal implant and the lateral transfibular approach demonstrated improved patient-reported outcomes and increased ankle motion at a minimum follow-up of 2 years. In the 55 consecutive cases, the fibular osteotomy required for access to the ankle healed without complications. Painful early loosening due to lack of osseous ingrowth required revision in 3 of 55 cases.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Midterm Outcomes of a Fixed-Bearing Total Ankle Arthroplasty With Deformity Analysis

BACKGROUND

We present our results with an INBONE I (Wright Medical, Memphis, TN) prosthesis that have a minimum of 4 to 10 years of follow-up and include a preoperative deformity analysis on outcomes.

METHODS

A consecutive series of 149 patients, from 2007 to 2011, at a single institution were enrolled. Pain and patient-reported function were assessed preoperatively and at yearly follow-ups. We analyzed the data for complications, reoperations, and failures (defined as undergoing revision for exchange or removal of one or both metallic components for any reason). Patients were also grouped according to coronal plane tibiotalar alignment; either ≥10 degrees or <10 degrees, and these outcomes were compared. Our follow-up ranged from 48 to 113 months (average 5.9 years).

RESULTS

There was significant improvement ( P < .05) in the visual analog scale for pain, American Orthopaedic Foot & Ankle Society hindfoot scale, Short Musculoskeletal Function Assessment, and Short Form 36-Item Health Survey scores at most recent follow-up. There were 14 implant failures with overall survivorship of 90.6% (135/149). Reasons for failure included cysts/loosening (7), talar subsidence (4), fractured component (1), impingement pain (1), and infection (1). Seventy-two patients (48.3%) with preoperative coronal plane deformity of ≥10 degrees varus or valgus were compared to 78 patients (51.7%) with <10 degrees deformity. There was no difference in patient outcome scores or revision rates between these patient groups. There was a statistically significant difference ( P = .039) in reoperation rates among patients with ≥10 degrees deformity (22.2%) compared to those without such a deformity (37.7%) Conclusion: Patients who underwent INBONE I fixed-bearing total ankle arthroplasty demonstrated significant improvement in outcomes at a mean of 5.9 years. Catastrophic talar component collapse did occur (2.7% of cases), but relatively rarely. The patients with preoperative coronal plane tibiotalar deformity had similar pain relief, function, and need for revision of implant components. Despite the presumed shortcomings of the INBONE I's design, this implant showed promising results, with or without deformity, at midterm follow-up with survivorship of 90.6%.

LEVEL OF EVIDENCE

Level III, comparative study.

Complex Total Ankle Arthroplasty

Total ankle arthroplasty is a viable surgical technique for the treatment of end-stage degenerative joint disease. With continued advancement in prosthetic design, refined surgical techniques, and improved outcomes, the indications for total ankle replacement have expanded to include cases of increasing complexity. With meticulous preoperative planning and exacting execution, many frontal plane deformities and cases of avascular necrosis can now be successfully addressed at the time of prosthesis implantation or in a staged procedure.

Malalignment Correction of the Lower Limb Before, During, and After Total Ankle Arthroplasty

One of the main challenges in ankle replacement is correction of any deformities in the operative limb. Deformity can be found proximal and distal to the ankle joint as well as in the ankle joint. There are static and dynamic deformities that can create unbalanced ankle joints causing early and often catastrophic failure. Surgeons must recognize the deformities that are present and use sound judgment to balance the ankle joint with procedures before, during, or after total ankle implantation. This article helps clinicians to identify deformity and provides a basic template to consider how to address each challenge.

Management of Talar Component Subsidence

Component subsidence has been found to be the top complication that leads to failure of the total ankle arthroplasty (TAA). The cause of subsidence formation is unclear, and is multifactorial. Talar subsidence is more frequently met than tibial subsidence, and the subsequent big bone loss is demanding to handle. As a revision treatment option, neither a revision TAA nor a salvage ankle and/or hindfoot arthrodesis procedure is easy to perform or can obtain a definite outcome. The Salto XT can be used to treat most of the TAA systems available for use in the United States with acceptable short-term outcomes.

Total Ankle Replacement with Severe Valgus Deformity: Technique and Surgical Strategy

Correction of severe valgus deformity of the foot and ankle with ankle replacement is challenging. We describe the controversies and specific issues of surgical management and provide a detailed surgical strategy for management of this common deformity. A reliable technique for deltoid reconstruction is also described and illustrated in detail.

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.

Variable Volumes of Resected Bone Resulting From Different Total Ankle Arthroplasty Systems

BACKGROUND

The increased popularity and success of total ankle arthroplasty (TAA) has resulted in the development of varying TAA hardware designs, many of which include specific bone-sparing or bone-sacrificing features. The goal of this work was to determine differences in the volume of bone removed for implantation of different total ankle arthroplasty hardware systems.

METHODS

Sixteen cadaveric specimens were computed tomography-scanned preoperatively and after total ankle arthroplasty using either an INBONE II, Salto Talaris, STAR, or Zimmer TMTA implant. Geometries of the talus and the distal tibia were manually segmented and converted to 3D bony surface models. The volume of bone removed for each implant was calculated as the difference in volume between the preoperative and postoperative bone models. To account for differences in specimen size, volume was expressed as a percentage of the intact bone.

RESULTS

There was a significant difference (P = .049) in the average percent of talar bone removed, with the STAR and INBONE II systems requiring removal of greater volumes of bone. The INBONE II system required significantly (P < .004) more tibial bone resection than the other 3 implants when evaluating a long span of the distal tibia. However, most of this increased bone resection was medullary bone. Close to the articular surface, bone volumes removed for the various tibial components were not significantly different (P = .056).

CONCLUSION

Volume and location of bone removed for different implant systems varied with implant design.

CLINICAL RELEVANCE

Primary bone resection associated with different implant hardware systems varied more on the talar side of the articulation, and the stemmed prosthesis did not result in dramatic increases in periarticular bone resection. Clinicians should weigh the effects of greater or lesser bone resection associated with various implant designs against other factors used for hardware selection.

Clinical Outcome and Fusion Rate Following Simultaneous Subtalar Fusion and Total Ankle Arthroplasty

BACKGROUND

Patients with arthritis or severe dysfunction involving both the ankle and subtalar joints can benefit from tibiotalocalcaneal (TTC) arthrodesis or total ankle replacement and subtalar fusion. TTC fusion is considered by many as a salvage operation resulting in a stiff ankle and hindfoot, considerably limiting global foot function. With the evolution of prosthetic design and operative techniques, total ankle replacement (TAR) has become a reasonable alternative to arthrodesis. The aim of this study was to investigate the fusion rate of the subtalar joint in patients simultaneously treated with total ankle replacement (TAR) and subtalar joint fusion.

METHODS

This study included 25 patients who underwent primary TAR and simultaneous subtalar fusion between May 2011 and November 2014. Sixteen males (64%) and 9 females (36%) were enrolled with a mean age of 58 years (25-82). Patients were clinically assessed preoperatively and at 6 and 12 months postoperatively. Total follow-up time was 24.2 ± 11.6 months. Radiographic examination included a postoperative computed tomographic (CT) scan obtained 12 months after surgery. Three surgeons independently reviewed the CT scans and interobserver reliability was calculated. Functional scores were also assessed.

RESULTS

At 12 months postoperatively, the subtalar fusion rate in patients treated with TAR and simultaneous subtalar fusion was 92%. There was a statistically significant increase in American Orthopaedic Foot & Ankle Society ankle/hindfoot score from 27.9 to 75.1. Ankle range of motion significantly increased from 12 to 32.8 degrees. Additionally, there was a statistically significant decrease in visual analog scale pain score from 8.6 to 2.1.

CONCLUSIONS

TAR and simultaneous subtalar joint fusion were reliable procedures for the treatment of ankle and subtalar joint arthritis. Furthermore, CT scans showed an excellent reliability among orthopedic surgeons in determining the degree of successful fusion of subtalar arthrodesis.

LEVEL OF EVIDENCE

Level IV, case series.

Secondary Arthrodesis After Total Ankle Arthroplasty

BACKGROUND

While it is thought that stresses through the subtalar and talonavicular joints will be decreased after total ankle replacement (TAR) relative to ankle fusion, progressive arthritis or deformity of these joints may require a fusion after a successful TAR. However, after ankle replacement, it is unknown how hindfoot biomechanics and blood supply may be affected. Consequently, subsequent hindfoot joint fusion may be adversely affected.

METHODS

We retrospectively identified a consecutive series of 1001 primary TARs performed between January 1998 and December 2014. We identified patients who underwent a secondary triple, subtalar or talonavicular arthrodesis to treat progressive arthritis or pes planus deformity. Clinical outcomes including pain and functional outcome scores, revision procedures, delayed union, nonunion, complications, and failure rates were recorded. Twenty-six patients (2.6%) required a subtalar (18), talonavicular (3), talonavicular and subtalar (3), or triple arthrodesis (2). Of these patients, 14 (54%) were males with an average age of 63.2 years and a mean 70.9 months follow-up. We then compared these patients to 13 patients who had a subtalar fusion after an ankle arthrodesis.

RESULTS

The most common type of fixation used was 2 variable-pitch screws across each joint. Fresh-frozen allograft cancellous chips were the most common supplement to the fusion construct (80.8%). The mean time between TAR and secondary fusion procedure was 37.5 months. Overall, 92.3% of the patients went on to fusion. Two patients (7.7%) had a delayed union and 2 patients had a nonunion (7.7%) and were considered operative failures. There were 3 repeat procedures related to the arthrodesis procedure: 1 conversion of a subtalar to a triple arthrodesis, 1 revision talonavicular fusion, and 1 revision subtalar fusion. The average time to weight bearing after arthrodesis was 8.7 weeks; the mean time to radiographic and clinical fusion was 26.5 weeks. There were no secondary complications associated with the arthrodesis. Pain and functional outcome scores improved significantly. There were no differences in the rates of subsequent fusions among implant choices, though the time to fusion in the mobile-bearing prosthesis was significantly longer than the 2 fixed-bearing prostheses. Compared with the data of 13 patients with prior ipsilateral ankle arthrodeses and subtalar fusions, patients who had an ankle replacement had a higher fusion rate (P = .03) and had a similar time to fusion.

CONCLUSION

Hindfoot arthrodesis following a TAR was safe and effective in improving function and pain. Additionally, a hindfoot arthrodesis following a TAR had a higher fusion rate than a subtalar fusion following an ankle arthrodesis. Although the time to healing was relatively long, various hindfoot fusions were used to treat progressive arthritis and deformity with high fusion rates.

LEVEL OF EVIDENCE

Level III, comparative case series.

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.

Reduction in post-operative acute kidney injury following a change in antibiotic prophylaxis policy for orthopaedic surgery: an observational study

OBJECTIVES

Evidence has shown that a prophylactic antibiotic regimen of flucloxacillin and gentamicin for orthopaedic surgery was associated with increased rates of post-operative acute kidney injury (AKI). This resulted in changes in the national antibiotic policy recommendation for orthopaedic surgical prophylaxis. This study aimed to assess whether this change from flucloxacillin and gentamicin to co-amoxiclav was associated with changes in the rates of AKI and Clostridium difficile infection (CDI).

METHODS

An observational study and interrupted time series analyses were used to assess rates of post-operative AKI separately in patients undergoing neck of femur (NOF) repair and other orthopaedic operations that required antibiotic prophylaxis. Incidence rate ratios were used to evaluate changes in CDI rates.

RESULTS

Following the change in policy, from flucloxacillin and gentamicin to co-amoxiclav, there was a relative change in rates of post-operative AKI of -63% (95% CI -77% to -49%) at 18 months in the other orthopaedic operations group. In the NOF repair group, there was no change in the rate of post-operative AKI [-10% (95% CI -35%-15%)] at 18 months. The incident rate ratio for CDI in the other orthopaedic operations group was 0.29 (95% CI 0.09-0.96) and in the NOF repair group was 0.76 (95% CI 0.28-2.08).

CONCLUSIONS

The use of co-amoxiclav for antibiotic prophylaxis in orthopaedic surgery was associated with a decreased rate of post-operative AKI compared with flucloxacillin and gentamicin and was not associated with increased rates of CDI.

An Alumina Ceramic Total Talar Prosthesis for Osteonecrosis of the Talus

BACKGROUND

Treatment of osteonecrosis of the talus is challenging. Total talar replacement has the potential to restore the function of the ankle joint without an associated leg-length discrepancy. The purpose of the present study was to investigate postoperative function and pain after total talar replacement in patients with osteonecrosis of the talus.

METHODS

Fifty-five ankles in fifty-one consecutive patients with osteonecrosis of the talus who were treated with a total talar replacement from 2005 to 2012 were included in the investigation. Scores according to the Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale and the Ankle Osteoarthritis Scale (AOS) were assessed before surgery and at the final follow-up evaluation.

RESULTS

According to the JSSF ankle-hindfoot scale, the score for pain improved from a mean (and standard deviation) of 15 ± 9.4 points (range, 0 to 20 points) to 34 ± 5.6 points (range, 20 to 40 points); the score for function, from 21.2 ± 9.7 points (range, 4 to 38 points) to 45.1 ± 4.0 points (range, 37 to 50 points); the score for alignment, from 6.0 ± 2.8 points (range, 5 to 10 points) to 9.8 ± 0.9 points (range, 5 to 10 points); and the total score, from 43.1 ± 17.0 points (range, 11 to 68 points) to 89.4 ± 8.4 points (range, 76 to 100 points). According to the AOS scale, the score for "pain at its worst" improved from a mean of 6.1 ± 3.3 points (range, 0 to 9.9 points) to 2.0 ± 1.7 points (range, 0 to 6.3 points).

CONCLUSIONS

Prosthetic talar replacement is a useful procedure for patients with osteonecrosis of the talus as it maintains ankle function.

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.

Incidence of revision after primary implantation of the Salto ® mobile version and Salto Talaris ™ total ankle prostheses: a systematic review

The incidence of revision of total ankle replacement prostheses remains unclear. We undertook a systematic review to identify the material relating to the incidence of revision after implantation of the Salto(®) mobile version and Salto Talaris™ total ankle prostheses. Studies were eligible for inclusion only if they had involved primary total ankle replacement with these prostheses and had included the incidence of revision. Eight studies involving 1,209 Salto(®) mobile version prostheses, with a weighted mean follow-up period of 55.2 months, and 5 studies involving 212 Salto Talaris™ total ankle prostheses, with a weighted mean follow-up period of 34.9 months, were included. Forty-eight patients with Salto(®) mobile version prostheses (4%) underwent revision, of whom 24 (70.5%) underwent ankle arthrodesis, 9 (26.5%) metallic component replacement, and 1 (3%) below-the-knee amputation. Five (2.4%) Salto Talaris™ total ankle prostheses underwent revision (3 metallic component replacement and 2 ankle arthrodeses). Restricting the data to the inventor, design team, or disclosed consultants, the incidence of revision was 5.2% for the Salto(®) mobile version and 2.6% for the Salto Talaris™ total ankle prostheses. In contrast, data that excluded these individuals had an incidence of revision of 2.8% for the Salto(®) mobile version and 2.0% for the Salto Talaris™ total ankle prostheses. We could not identify any obvious difference in the etiology responsible for the incidence of revision between these mobile- and fixed-bearing prostheses. The incidence of revision for the Salto(®) mobile version and Salto Talaris™ total ankle prostheses was lower than those reported through systematic review for the Agility™ and Scandinavian Total Ankle Replacement™ systems without obvious selection (inventor) or publication (conflict of interest) bias.