Salto Talaris Total Ankle Arthroplasty: Clinical Results at a Mean of 5.2 Years in 78 Patients Treated by a Single Surgeon

Outcomes of Total Ankle Replacement

Total ankle replacement (TAR) is an effective operative treatment of end-stage ankle osteoarthritis (OA) in the appropriate patient, conferring improved kinematic function, decreased stress across adjacent joints, and offering equivalent pain relief in comparison to ankle arthrodesis (AA). It is important to consider patient age, weight, coronal tibiotalar deformity, joint line height, and adjacent joint OA to maximize clinical and patient outcomes. Both mobile-bearing and fixed-bearing implants have demonstrated favorable clinical outcomes, marked improvement in patient-reported outcomes, and good survivorship; however, implant survivorship decreases with longer term follow-up, necessitating constant improvement of primary and revision TAR options.

Printable functionally graded tibial implant for TAR: FE study comparing implant materials, FGM properties, and implant designs

Tibial implants with functionally graded material (FGM) for total ankle replacement (TAR) can provide stiffness similar to the host tibia bone. The FGM implants with low stiffness reduce stress shielding but may increase implant-bone micromotion. A trade-off between stress shielding and implant-bone micromotion is required if FGMs are to substitute traditionally used Ti and CoCr metal implants. The FGM properties such as material gradation law and volume fraction index may influence the performance of FGM implants. Along with the FGM properties, the design of FGM implants may also have a role to play. The objective of this study was to examine FGM tibial implants for TAR, by comparing implant materials, FGM properties, and implant designs. For this purpose, finite element analysis (FEA) was conducted on 3D FE models of the intact and the implanted tibia bone. The tibial implants were composed of CoCr and Ti, besides them, the FGM of Ti and HA was developed. The FGM implants were modelled using exponential, power, and sigmoid laws. Additionally, for power and sigmoid laws, different volume fraction indices were taken. The effect of implant design was observed by using keel type and stem type TAR fixation designs. The results indicated that FGM implants are better than traditional metal implants. The power law is most suitable for developing FGM implants because it reduces stress shielding. For both power law and sigmoid law, low values of the volume fraction index are preferrable. Therefore, FGM implant developed using power law with 0.1 vol fraction index is ideal with the lowest stress shielding and marginally increased implant-bone micromotion. FGM implants are more useful for keel type fixation design than stem type design. To conclude, with FGMs the major complication of stress shielding can be solved and the longevity and durability of TAR implants can be enhanced.

Outcomes of Total Ankle Arthroplasty After Reoperation due to Gutter Impingement

Gutter impingement is one of the most common causes of subsequent surgery after total ankle arthroplasty (TAA). Although gutter debridement has been reported to resolve preoperative symptoms early on, persistent pain after surgery, recurrence, and poor functional outcome scores have been described in patients who have undergone reoperation for gutter debridement. The cause of gutter impingement after TAA is multifactorial, and a better understanding of its causes and optimal surgical techniques for intervention is needed.

Staged vs concurrent hardware removal in total ankle arthroplasty

INTRODUCTION

Ankle osteoarthritis is more commonly posttraumatic. Consequently, dealing with hardware removal is quite frequent when performing a total ankle arthroplasty (TAA). The purpose of this study is to compare outcomes regarding either a staged or concurrent hardware removal when performing TAA.

MATERIALS AND METHODS

275 consecutive patients with TAA previously treated with internal fixation were retrospectively reviewed. Finally, 57 patients were enrolled based on exclusion criteria, and were differentiated into two groups considering the timing of hardware removal (staged-group A vs concurrent-group B) to compare: neurovascular and wound complications, time to recover full weight bearing, scar-tissue esthetic, and surgical time. Moreover, a subgroup comparison considering the surgical approach (single approach, minor additional approach, major additional approach) was performed between the group A and group B.

RESULTS

No statistically significant difference other that longer surgical time (p < 0.05) was observed between group A and group B. When considering surgical approach subgroups, statistically significant higher surgical wound complications and revision rate were reported in group B (concurrent) major additional approach subgroup, and a statistically significant shorter time to full weight bearing was reported in group A (staged) major additional approach subgroup.

CONCLUSIONS

When performing TAA requiring hardware removal, no clear superiority of staged over concurrent hardware removal was observed. However, when considering a subgroup of patients requiring a separate major incision, a staged approach has shown reduced surgical time, less risk of wound complications, and shorter recovery to full weight bearing.

LEVEL OF EVIDENCE

III.

Salto Talaris Fixed-Bearing Total Ankle Arthroplasty: Long-Term Results at a Mean of 10.7 Years

Background

Total ankle arthroplasty (TAA) has become increasingly popular in the treatment for end-stage ankle arthritis in recent decades. However, there is limited evidence regarding the long-term clinical outcomes and complication rates of modern TAA implants.

Methods

This study presents a follow-up on a previous cohort involving 78 patients (81 ankles) who underwent Salto Talaris fixed-bearing TAA to treat end-stage arthritis, with a mean postoperative follow-up of 5.2 years. The aim of this follow-up study was to assess the radiographic (33 patients, 35 ankles) and clinical (48 patients, 50 ankles) results from the original cohort at a mean of 10.7 years (range, 7.8-14 years).

Results

At a mean of 10.7 years, the Kaplan-Meier estimated survivorship was 84.2% (95% CI, 71.9%-98.6%). For the patients reviewed, we did not find any change in patient-reported outcomes between an average 5- and 11-year follow-up. Measured total range of motion and plantarflexion did not change between 1 and 11 years, but dorsiflexion was measured as decreasing by an average of 4 degrees (P < .02).

Conclusion

In this longer-term follow-up of a limited cohort, we found that Salto Talaris fixed-bearing TAA demonstrated good long-term survival with relatively low rates of revision or other complications. Patient-reported outcome and range of motion measures revealed good stability.

Level of Evidence

Level III, therapeutic.

Prospective Multicenter Study of Salto Talaris Ankle Arthroplasty With Minimum 4-Year Follow-Up

BACKGROUND

Total ankle arthroplasty (TAA) continues to be investigated as a primary treatment for end-stage ankle arthritis. The objective of this study is to report mid- to long-term results of the Salto Talaris TAA using prospectively collected patient-reported outcomes and implant survival rates with 4- to 13-year follow-up.

METHODS

This was a retrospective study of prospectively collected data from 2 multicenter cohort studies from 3 centers. Three hundred fourteen subjects who received a Salto Talaris TAA from 2005 to 2015 were included in the study. Follow-up ranged 4-13 years following index procedure. Outcomes included 36-Item Short Form Health Survey (SF-36) mental and physical component summary scores, pain scores, and adverse events including additional surgeries, revision, or removal of components.

RESULTS

Significant improvements were seen in pain and physical function scores at 2-year follow-up and were generally maintained through most recent follow-up. The survival rate of the prosthesis was >95% (n = 30/32 at >10 years, n = 272/282 at 4.5-10 years). Thirteen patients (4.1%) underwent revision or removal of their prosthesis. Time to revision ranged from 2 months to 6.5 years following the index procedure. Twenty-two patients (7.0%) had additional surgery that did not involve revision or removal of components.

CONCLUSION

Treatment of end-stage ankle arthritis with this implant provided patients with improved pain and functional outcome scores at mid- to long-term follow-up. The significant improvements reported at 2-4 years appeared to endure through the extended follow-up period.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Mid-term functional outcomes following reoperation after total ankle arthroplasty: A retrospective cohort study

BACKGROUND

Despite a significant reported rate of non-revision reoperation after total ankle arthroplasty (TAA), it is uncertain if these subsequent procedures have an impact on the longer term outcomes. This study aimed to compare minimum five-year functional outcomes of patients who had undergone reoperation after TAA to those who did not require reoperation.

METHODS

Seventy-six ankles (74 patients) who underwent TAA with the Salto Talaris fixed bearing system between 2007 and 2014 were allocated into two groups based on presence (n = 16) or absence of reoperation (n = 60). Reoperations included all secondary procedures after index TAA, excluding revision surgeries requiring removal or exchange of the original prosthesis. The foot and ankle outcome score (FAOS) at preoperative and minimum five-year follow-up was compared between the groups. Additionally, improvements in FAOS subscales were compared. Preoperative deformity, postoperative implant alignment, number of periprosthetic cysts, and subsidence between groups were compared using standard weightbearing radiographs.

RESULTS

The most common cause of reoperation was gutter impingement (n = 11), followed by stress fracture of the medial malleolus (n = 2), tarsal tunnel syndrome (n = 1), periprosthetic cyst (n = 1), and infection (n = 1). In comparison to the non-reoperation group, all FAOS subscales except for the Sports and Recreational Activities subscale were significantly lower in the reoperation group at final follow-up. The reoperation group exhibited significantly less improvement in the Pain, Symptoms, and Quality of Life subscales at final follow-up (p < 0.05). There were no statistical differences in the radiographic parameters between both groups.

CONCLUSIONS

Patients who underwent reoperation after TAA demonstrated inferior functional outcomes at mid-term follow-up. An emphasis should be placed on preventing possible causes of reoperations to achieve favorable patient outcomes. Additionally, if a reoperation is deemed necessary, a thorough evaluation and surgical correction of underlying causes should be achieved.

Early Radiographic and Clinical Outcomes of a Novel, Fixed-Bearing Fourth-Generation Total Ankle Replacement System

BACKGROUND

The Cadence Total Ankle System is a 2-component, fixed-bearing fourth-generation total ankle arthroplasty (TAA) system that was introduced for clinical use in 2016. The purpose of this study was to report non-inventor, non-industry funded survivorship, radiographic and clinical outcomes, and early complications following use of this implant at a minimum of 2 years.

METHODS

This single-center retrospective study included patients who underwent TAA by 2 surgeons with this novel fixed-bearing system between January 2017 and September 2018. Forty-eight patients were evaluated at an average of 33.6 months. Radiographic outcomes included preoperative and postoperative tibiotalar angle on anteroposterior radiographs of the ankle, sagittal tibial angle (STA) on lateral radiographs of the ankle, and periprosthetic lucency formation and location. Revision and reoperation data were collected, and patient-reported outcomes were assessed using Patient Reported Outcomes Measurement Information System (PROMIS). Subgroup analysis assessed associations between preoperative deformity, postoperative implant alignment, PROMIS scores, and periprosthetic lucency formation.

RESULTS

Survivorship of implant was 93.7%, with 3 revisions, 1 due to infection and 2 due to loosening of the implant (1 tibial and 1 talar component). Three patients had reoperations (6.3%): 2 for superficial infection and 1 for gutter debridement due to medial gutter impingement. Fifteen patients (35.8%) developed periprosthetic lucencies, all on the tibial side. PROMIS scores improved after surgery in all domains except Depression. Patients with significant postoperative periprosthetic lucency had worse postoperative PROMIS Physical function scores than patients without lucency (P < .05).

CONCLUSION

This study demonstrated excellent minimum 2-year clinical and radiographic outcomes and low revision and reoperation rates of this new fourth-generation TAA system. Future studies with longer follow-up, especially on patients with periprosthetic lucency, are necessary to investigate the long-term complications and understand the long-term functional and radiographic outcomes of this implant.

Retrospective Comparison of Midterm Survivorship, Radiographic, and Clinical Outcomes of the INBONE II and Salto Talaris Total Ankle Arthroplasty Systems

BACKGROUND

Prior studies on the INBONE II and Salto Talaris total ankle arthroplasty (TAA) systems have reported promising outcomes for both implants. This retrospective study aimed to compare the midterm differences between INBONE II and Salto Talaris TAA.

METHODS

Between 2007 and 2015, a total of 44 INBONE II consecutive cases and 85 Salto Talaris consecutive cases had minimum 5-year clinical and radiographic follow-up. Preoperative and midterm survivorship, postoperative Foot and Ankle Outcome Score (FAOS), and radiographic measures including tibiotalar alignment (TTA), medial distal tibial angle (MDTA), and sagittal tibial angle (STA) were compared.

RESULTS

Survivorship to revision was 97.6% (95% CI, 93.1%-100%) for the INBONE II group and 97% (95% CI, 93%-100%) for the Salto Talaris group (P = .93). Survivorship to reoperation was significantly different: 95.5% for the INBONE II and 76.4% for Salto Talaris (P = .021). Postoperative FAOS pain (P = .01), symptoms (P = .004), and sports activity (P = .02) scores were significantly higher in the INBONE II group. The INBONE group had greater preoperative deformity (varus TTA P < .001, valgus TTA P = .02, valgus MDTA P = .005).

CONCLUSION

Although both implants had similar longevity and postoperative alignment, the INBONE II resulted in greater clinical improvement and fewer reoperations than the Salto Talaris at midterm follow-up.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Dynamic finite element analyses to compare the influences of customised total talar replacement and total ankle arthroplasty on foot biomechanics during gait

Objective, Total talar replacement (TTR) using a customised talus prosthesis is an emerging surgical alternative to conventional total ankle arthroplasty (TAA) for treating ankle problems. Upon satisfying clinical reports in the literature, this study explored the advantages of TTR in restoring foot biomechanics during walking compared with TAA through computational simulations.Methods, A dynamic finite element foot model was built from the MRIs of a healthy participant and modified into two implanted counterparts (TTR and TAA) by incorporating the corresponding prosthetic components into the ankle joint. Twenty bony parts, thirty-nine ligament/tendon units, nine muscle contractors, and bulk soft tissue were included in the intact foot model. The TTR prosthesis was reconstructed from the mirror image data of the participant's contralateral talus and the TAA prosthesis was modelled by reproducing the Scandinavian ankle replacement procedure in the model assembly. The model was meshed with explicit deformable elements and validated against existing experimental studies that have assessed specific walking scenarios. Simulations were performed using the boundary conditions (time-variant matrix of muscle forces, segment orientation, and ground reaction forces) derived from motion capture analyses and musculoskeletal modelling of the participant's walking gait. Outcome variables, including foot kinematics, joint loading, and plantar pressure were reported and compared among the three model conditions.

RESULTS

Linear regression indicated a better agreement between the TTR model and intact foot model in plots of joint motions and foot segment movements during walking (R² ​= ​0.721-0.993) than between the TAA and intact foot (R² ​= ​0.623-0.990). TAA reduced talocrural excursion by 21.36%-31.92% and increased (MTP) dorsiflexion by 3.03%. Compared with the intact foot, TTR and TAA increased the midtarsal joint contact force by 17.92% and 10.73% respectively. The proximal-to-distal force transmission within the midfoot was shifted to the lateral column in TTR (94.52% or 210.54 ​N higher) while concentrated on the medial column in TAA (41.58% or 27.55 ​N higher). The TTR produced a plantar pressure map similar to that of the intact foot. TAA caused the plantar pressure centre to drift medially and increased the peak forefoot pressure by 7.36% in the late stance.

CONCLUSION

The TTR better reproduced the foot joint motions, segment movements, and plantar pressure map of an intact foot during walking. TAA reduced ankle mobility while increasing movement of the adjacent joints and forefoot plantar pressure. Both implant methods changed force transmission within the midfoot during gait progression.The translational potential of this article Our work is one of the few to report foot segment movements and the internal loading status of implanted ankles during a dynamic locomotion task. These outcomes partially support the conjecture that TTR is a prospective surgical alternative for pathological ankles from a biomechanical perspective. This study paves the way for further clinical investigations and systematic statistics to confirm the effects of TTR on functional joint recovery.

Post-operative management after total ankle arthroplasty: A systematic review of the literature

BACKGROUND

Currently, there is no consensus on the most appropriate post-operative management for patients undergoing total ankle arthroplasty. The aim of this study is therefore to offer a systematic review of the pertaining literature to identify current post-operative protocols and describe possible differences.

METHODS

A systematic review to identify recent studies concerning the post-operative management after total ankle arthroplasty was conducted. Five topics were analyzed: length of hospital stay, type and duration of immobilization, weight-bearing management, post-operative pharmacological therapies, adopted rehabilitation scheme.

RESULTS

Eighty-four studies met the inclusion criteria and were included in the review process. Most of the papers appear to have conflicting opinions with no consensus and homogeneous protocols.

CONCLUSION

Due to various methodological limitations, it is not possible to provide sufficiently supported evidence-based recommendations, and it is therefore difficult to determine the superiority of one post-operative protocol over the others after total ankle arthroplasty.

Multi-segment foot kinematics during gait following ankle arthroplasty

Ankle arthritis is a debilitating disease marked by pain and limited function. Total ankle arthroplasty improves pain while preserving motion and offers an alternative to the traditional treatment of ankle fusion. Gait analysis and functional outcomes tools can provide an objective balanced analysis of ankle replacement for the treatment of ankle arthritis. Twenty-nine patients with end-stage ankle arthritis were evaluated before and after ankle arthroplasty. Multi-segment foot and ankle kinematics were assessed annually following surgery (average 3.5 years, range 1-6 years) using the Milwaukee Foot Model and a Vicon video motion analysis system. Functional outcomes (American Orthopedic Foot and Ankle Society [AOFAS] ankle/hindfoot scale, short form 36 [SF-36] questionnaire) and temporal-spatial parameters were also assessed. Kinematic results were compared to findings from a previously collected group of healthy ambulators. AOFAS and SF-36 mean scores improved postoperatively. Walking speed and stride length increased after surgery. There were significant improvements in tibial sagittal range of motion in terminal stance and hindfoot sagittal range of motion in preswing. Decreased external rotation of the tibia and increased external rotation of the hindfoot were noted throughout the gait cycle. Pain and function improved after ankle replacement as supported by better outcomes scores, increased temporal-spatial parameters, and significant improvement in tibial sagittal range of motion during terminal stance and hindfoot sagittal range of motion during preswing. While multi-segment foot kinematics were improved, they were not restored to control values. Statement of clinical significance: Total ankle arthroplasty does not fully normalize mutli-segment gait kinematics despite improved patient-reported outcomes and gait mechanics.

Outcomes and Complications of the INFINITY Total Ankle: A Systematic Review

IV.

Revision Rates After Total Ankle Replacement: A Comparison of Clinical Studies and Arthroplasty Registers

BACKGROUND

The aim of this study was to assess the outcome of total ankle replacement (TAR) regarding revision rates by comparing clinical studies of the last decade to data displayed in arthroplasty registers. The secondary aim was to evaluate whether dependent clinical studies show a superior outcome to independent publications. Additionally, revision rates of mobile bearing implants (MB-TARs) were compared to those of fixed bearing implants (FB-TARs).

METHODS

Clinical studies on TARs between 2010 and 2020 were systematically reviewed, with the endpoint being a revision for any reason. The parameter "revision rate per 100 observed component years (CYs)" was calculated for each publication. The pooled revision rate for clinical studies was compared to the data reported in arthroplasty registers. In a second step, revision rates were subdivided and analyzed for independent and dependent publications and for FB-TARs and MB-TARs.

RESULTS

A total of 43 publications met the inclusion criteria comprising 5806 TARs. A revision rate of 1.8 per 100 observed CYs was calculated, corresponding to a 7-year revision rate of 12.6%. The 3 arthroplasty registers included showed revision rates ranging from 8.2% to 12.3% after 7 years. No significant difference between dependent and independent publications nor between FB-TARs and MB-TARs was detected.

CONCLUSION

Revision rates of clinical studies and arthroplasty registers are comparable. Surgeons can compare their own revision rates with those from this study. Dependent studies do not seem to be biased, and no superiority for one bearing type can be described.

LEVEL OF EVIDENCE

Level III, systematic review of level III studies.

Three-Year Rates of Reoperation and Revision Following Mobile Versus Fixed-Bearing Total Ankle Arthroplasty: A Cohort of 302 Patients with 2 Implants of Similar Design

BACKGROUND

Currently, the implants utilized in total ankle arthroplasty (TAA) are divided between mobile-bearing 3-component and fixed-bearing 2-component designs. The literature evaluating the influence of this mobility difference on implant survival is sparse. The purpose of the present study was therefore to compare the short-term survival of 2 implants of similar design from the same manufacturer, surgically implanted by the same surgeons, in fixed-bearing or mobile-bearing versions.

METHODS

All patients were enrolled who underwent TAA with either the mobile-bearing Salto (Tornier and Integra) or the fixed-bearing Salto Talaris (Integra) in 3 centers by 2 surgeons between January 2004 and March 2018. All patients who underwent TAA from January 2004 to April 2013 received the Salto implant, and all patients who underwent TAA after November 2012 received the Salto Talaris implant. The primary outcome was time, within 3 years, to first all-cause reoperation, revision of any metal component, and revision of any component, including the polyethylene insert. Secondary outcomes included the frequency, cause, and type of reoperation.

RESULTS

A total of 302 consecutive patients were included, of whom 171 received the mobile-bearing and 131 received the fixed-bearing implant. The adjusted hazard ratio for all-cause reoperation was 1.42 (95% confidence interval [CI], 0.67 to 3.00; p = 0.36); for component revision, 3.31 (95% CI, 0.93 to 11.79; p = 0.06); and for metal component revision, 2.78 (95% CI, 0.58 to 13.33; p = 0.20). A total of 31 reoperations were performed in the mobile-bearing group compared with 14 in the fixed-bearing group (p = 0.07). More extensive reoperation procedures were performed in the mobile-bearing group.

CONCLUSIONS

With the largest comparison of 2 implants of similar design from the same manufacturer, the present study supports the use of a fixed-bearing design in terms of short-term failure. We found a 3-times higher rate of revision among mobile-bearing implants compared with fixed-bearing implants at 3 years after TAA. Reoperations, including first and subsequent procedures, tended to be less common and the causes and types of reoperations less extensive among fixed-bearing implants.

LEVEL OF EVIDENCE

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

Investigation on the contour and bone mineral density of the distal tibial cutting surface used for total ankle arthroplasty

PURPOSE

This study was designed to investigate (1) the contour of the distal tibial cutting surface, and (2) the bone mineral density (BMD) of the distal tibial cutting surface used during total ankle arthroplasty (TAA).

METHODS

Eight-four distal tibial models were created using foot and ankle computerized tomographic (CT) images taken from normal people. The distal tibial cutting surface for TAA was determined to be 10 mm proximal to the tibial plafond. The bony contour and BMD values were determined from the CT image at that level. A bounding box was made on the contour and the width and length of the contour was measured. Regional BMD was evaluated by Hounsfield units (HU) value measurement, with 7 regions of interest (ROI) on 8 different directions for all the 84 CT images. Two different observers made independent measurements and mean HU values for all the 56 ROIs were calculated.

RESULTS

Great variations were found among the contours of the cutting surface especially in term of the shape of the anterior and posterior tibial tubercle, and the fibular notch. These variations could be grouped into six categories. For the BMD of the cutting surface, the medial border of the cutting surface did not included cortical bone. The HU value of seven ROIs, which included cortical bone, were significantly greater than all the other ROIs. Few statistical differences were found by multiple comparisons among HU value of all the 49 ROIs without cortex.

CONCLUSIONS

Great variability existed in the shape and the BMD of the distal tibial cutting surface.

Effect of Gender Differences on Patient-Reported Outcomes and Complications in Total Ankle Replacement

BACKGROUND

The purpose of this study was to evaluate gender differences in patient outcomes and complications following total ankle replacement (TAR).

METHODS

Consecutive patients who underwent primary TAR from July 2007 through May 2016 were prospectively followed and retrospectively reviewed. Demographic, operative, patient-reported outcomes (PROs), and complication data were collected and analyzed. PROs included the visual analog scale (VAS), 36-Item Short-Form Health Survey (SF-36), American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scale, and Short Musculoskeletal Function Assessment (SMFA). A total of 475 patients were evaluated, including 248 males (52.2%) and 227 females (47.8%) with an average of 56.8 months follow-up.

RESULTS

Women were more likely to have inflammatory arthritis (13.7% vs 2.8%; P < .01) and significantly worse preoperative SF-36 total, SF-36 mental health component, AOFAS total, AOFAS pain, SMFA function, and SMFA bother scores (all P < .05). Both genders demonstrated significant improvement in PROs at 1, 2, and 5 years. The magnitude of improvement was similar between genders for all PROs (all P < .05) with the exception of SF-36 physical function, which was greater in men. Females underwent more nonrevision reoperations (32.2% vs 22.6%; P = .0191), but there was no significant difference in failure rates (male 7.3% vs female 3.5%; P = .07). The reoperation and failure rates at 2 years postoperation were 10.1% and 1.6% for men and 18.5% and 0.9% for women, respectively.

CONCLUSION

Women undergoing TAR were more likely to have worse preoperative PROs and higher rates of nonrevision reoperations, which remains true when controlling for their increased incidence of inflammatory arthritis. However, women reported similar improvements in PROs and had similar prosthetic survival rates as men. Increased understanding of these disparities, combined with gender-based interventions, may further advance patient outcomes.

LEVEL OF EVIDENCE

Level III, therapeutic, retrospective comparative series.

Intermediate-term Patient-Reported Outcomes and Radiographic Evaluation Following Intramedullary- vs Extramedullary-Referenced Total Ankle Replacement

BACKGROUND

The purpose of this study was to report on the radiographic outcomes, clinical outcomes, and implant survivorship following extramedullary-referenced (EMr) vs intramedullary-referenced (IMr) total ankle replacement (TAR).

METHODS

From May 2007 to February 2018, a consecutive series of patients with end-stage tibiotalar osteoarthritis undergoing TAR was enrolled in this study. Analyses were performed comparing IMr vs EMr components for patient-reported outcomes data, pre- and postoperative radiographic ankle alignment, concomitant procedures, and complications. Kaplan-Meier survivorship analyses served to determine implant reoperation and revision surgery. A total of 340 TARs were included with 105 IMr TAR and 235 EMr TAR. The mean follow-up was 5.3 years (±2.5, range 2-12).

RESULTS

The absolute value for preoperative coronal alignment was significantly greater for IMr compared to EMr TAR (13.0 vs 6.4 degrees; P < .0001), but both groups achieved near neutral alignment postoperatively (1.4 vs 1.5 degrees; P = .6655). The odds of having a concomitant procedure was 2.7 times higher in patients with an IMr TAR (OR 2.7, CI 1.7-4.4; P < .0001). There were similar improvements in patient-reported outcome scores at 1 year and final follow-up (all P > .05). The 5-year implant survivorship was 98.6% for IMr vs 97.5% for EMr at final follow-up.

CONCLUSION

The IMr and EMr TAR components had comparable postoperative alignment, patient-reported outcome scores, and complications. The 5-year implant survivorship was similar between the IMr and EMr groups.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Timeline for maximal subjective outcome improvement following total ankle arthroplasty

BACKGROUND

Maximal medical improvement (MMI) establishes the timepoint when patients no longer experience clinically significant improvements following surgery. The purpose of this investigation is to establish when patients achieve MMI following total ankle arthroplasty (TAA) through the use of patient reported outcome measures (PROMs).

METHODS

A systematic review to identify studies on TAA which reported consecutive PROMs for two years postoperatively was performed. Pooled analysis was done at 6 months, 12 months, and 24 months. Clinically significant improvement was defined as improvement between time intervals exceeding the minimal clinically important difference.

RESULTS

Twelve studies and 1514 patients met inclusion criteria. Clinically significant improvement was seen up to 6 months postoperatively in both the American Orthopaedic Foot and Ankle Society Ankle Hindfoot Score and Visual Analog Scale scoring systems. The Short Musculoskeletal Function Assessment Dysfunction and Bother subsections showed maximal clinically significant improvement by 1 year postoperatively.

CONCLUSION

Following TAA, MMI is seen by one year postoperatively. Physicians may allocate the majority of resources within the first year when most of the improvement is perceived. This data may help inform preoperative counseling as it establishes a timeline for MMI.

LEVEL OF EVIDENCE

IV.

Economic Analysis and Clinical Outcomes of Short-Stay Versus Inpatient Total Ankle Replacement Surgery

BACKGROUND

We aimed to perform an economic analysis and compare the clinical outcomes between inpatient and short-stay designation total ankle replacement (TAR).

METHODS

We performed a retrospective study on 178 consecutive patients undergoing primary inpatient versus short-stay designation TAR during the 2016 and 2017 fiscal years. Patient demographics, concomitant procedures, perioperative complications, patient-reported outcomes, and perioperative costs were collected.

RESULTS

The mean age of our cohort was 62.5 ± 9.6 years (range, 30-88 years), with a significant difference in age (64.1 vs 58.5 years) (P = .005) and Charlson Comorbidity Index (3.3 ± 1.9 vs 2.3 ± 1.4; P = .002) for the inpatient and short-stay designation groups, respectively. At a mean follow-up of 29.6 ± 11.8 months (range, 12-52.3 months), there was no difference in complications between groups (P = .97). The inpatient designation TAR group had a worse baseline Short Musculoskeletal Functional Assessment (SMFA) function score (76.1; 95% CI, 70.5-81.6) than the short-stay designation TAR group (63.9; 95% CI, 52.5-75.3) while achieving similar final postoperative SMFA function scores for the inpatient (55.2; 95% CI, 51.1-59.2) and short-stay (56.2; 95% CI, 48.2-64.2) designation TAR groups (P > .05). However, the inpatient designation TAR group showed a significantly greater mean improvement in SMFA function score (20.9; 95% CI, 19.4-22.4) compared with the short-stay designation TAR group (7.7; 95% CI, 3.7-11.1) (P = .0442). The total direct cost was significantly higher for the inpatient designation group ($15 340) than the short-stay designation group ($13 002) (P < .001).

CONCLUSION

While inpatient designation TARs were more comorbid, short-stay designation TARs were associated with a 15.5% reduction in perioperative costs, comparable complication rates, and similar final postoperative patient-reported outcome scores compared with inpatient TARs.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Radiographic and Clinical Outcomes of the Salto Talaris Total Ankle Arthroplasty

BACKGROUND

The Salto Talaris is a fixed-bearing implant first approved in the US in 2006. While early surgical outcomes have been promising, mid- to long-term survivorship data are limited. The aim of this study was to present the survivorship and causes of failure of the Salto Talaris implant, with functional and radiographic outcomes.

METHODS

Eighty-seven prospectively followed patients who underwent total ankle arthroplasty with the Salto Talaris between 2007 and 2015 at our institution were retrospectively identified. Of these, 82 patients (85 ankles) had a minimum follow-up of 5 (mean, 7.1; range, 5-12) years. The mean age was 63.5 (range, 42-82) years and the mean body mass index was 28.1 (range, 17.9-41.2) kg/m². Survivorship was determined by incidence of revision, defined as removal/exchange of a metal component. Preoperative, immediate, and minimum 5-year postoperative AP and lateral weightbearing radiographs were reviewed; tibiotalar alignment (TTA) and the medial distal tibial angle (MDTA) were measured to assess coronal talar and tibial alignment, respectively. The sagittal tibial angle (STA) was measured; the talar inclination angle (TIA) was measured to evaluate for radiographic subsidence of the implant, defined as a change in TIA of 5 degrees or more from the immediately to the latest postoperative lateral radiograph. The locations of periprosthetic cysts were documented. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared.

RESULTS

Survivorship was 97.6% with 2 revisions. One patient underwent tibial and talar component revision for varus malalignment of the ankle; another underwent talar component revision for aseptic loosening and subsidence. The rate of other reoperations was 21.2% (n = 18), with the main reoperation being exostectomy with debridement for ankle impingement (n = 12). At final follow-up, the average TTA improved 4.4 (± 3.8) degrees, the average MDTA improved 3.4 (± 2.6) degrees, and the average STA improved 5.3 (± 4.5) degrees. Periprosthetic cysts were observed in 18 patients, and there was no radiographic subsidence. All FAOS subscales demonstrated significant improvement at final follow-up.

CONCLUSIONS

We found the Salto Talaris implant to be durable, consistent with previous studies of shorter follow-up lengths. We observed significant improvement in radiographic alignment as well as patient-reported clinical outcomes at a minimum 5-year follow-up.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Does Patient-Specific Instrumentation Have a Higher Rate of Early Osteolysis Than Standard Referencing Techniques in Total Ankle Arthroplasty? A Radiographic Analysis

Introduction: Patient-specific instrumentation (PSI) has been developed for total ankle arthroplasty (TAA), with proven benefits. One concern regarding PSI is the need for more soft tissue dissection in order to accurately position the PSI guides, which has the theoretical disadvantage of increased osteolysis. The purpose of our study is to compare the incidence and magnitude of osteolysis for the INFINITY Total Ankle System between PSI and standard referencing (SR) techniques. Methods: Sixty-seven patients who underwent primary TAA using Prophecy (PSI) or SR technique between 2013 and 2015 were reviewed in a retrospective observational study. Osteolysis was assessed on radiographs at 2 years. The incidence was calculated by binomial distribution. The number of zones compromised and the magnitude of osteolysis was calculated using the median as a summary statistic and interquartile range as dispersion statistic. Fisher exact test was used to compare both groups, then a regression model was estimated to calculate the odds ratio for osteolysis. Results: Of the 67 TAAs, 51 were in the PSI group and 16 in the SR group. In the PSI group the incidence, number of compromised zones (CZ), and magnitude was 41% (25%-59%), 1 [1-2], and 2 [2-3], respectively. In the SR group these were 36% (13%-65%), 3 [2-3], and 3 [2-4], respectively. No significant differences were found (P = .46, P = .12, P = .33). A slightly higher risk of osteolysis was found in the PSI group (odds ratio = 1.33 [0.36-4.83]) (P = .46). The majority of lesions were in 1 zone with size of 2 to 5 mm (63% for all cohort, 64% PSI, 60% SR). Two cases underwent revision for aseptic loosening, 1 in the SR group and 1 in the PSI group. Conclusion: According to our data, there is no significant difference between PSI and SR in terms of risk, incidence, size and magnitude of osteolysis in the INFINITY Total Ankle System at 2 years. Levels of Evidence: Therapeutic, Level III, Retrospective cohort study.

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.

Current concepts in the management of ankle arthritis

Ankle arthritis is a common condition. It causes a significant socioeconomic burden, and is associated with significant morbidity. Patients with ankle arthritis are either elderly with significant co-morbidities, or young adults who have previously suffered with ankle injuries, resulting in post-traumatic arthritis. There is a wide variation in the management of these patients with ankle arthritis. We therefore present an overview of the current evidence based management of patients with symptomatic ankle arthritis.

Prospective Randomized Trial Comparing Mobile-Bearing and Fixed-Bearing Total Ankle Replacement

BACKGROUND

Outcomes of total ankle replacement for the treatment of end-stage ankle arthritis continue to improve. Debate continues whether a mobile-bearing total ankle replacement (MB-TAR) or a fixed-bearing total ankle replacement (FB-TAR) is superior, with successful outcomes reported long term for MB-TAR and at intermediate- to long-term follow-up for newer generation FB-TAR. Although comparisons between the 2 total ankle designs have been reported, to our knowledge, no investigation has compared the 2 designs with a high level of evidence. This prospective, randomized controlled trial conducted at a single institution compares patient satisfaction, functional outcomes, and radiographic results of the mobile-bearing STAR and the fixed-bearing Salto-Talaris in the treatment of end-stage ankle arthritis.

METHODS

Between November 2011 and November 2014, adult patients with end-stage ankle osteoarthritis failing nonoperative treatment were introduced to the study. With informed consent, 100 patients (31 male and 69 female, average age 65 years, range 35-85 years) were enrolled; a demographic comparison between the 2 cohorts was similar. Exclusion criteria included inflammatory arthropathy, neuropathy, weight exceeding 250 pounds, radiographic coronal plane deformity greater than 15 degrees, or extensive talar dome wear pattern ("flat-top talus"). Prospective patient-reported outcomes, physical examination, and standardized weightbearing ankle radiographs were obtained preoperatively, at 6 and 12 months postoperatively, and then at yearly intervals. Data collection included visual analog pain score, Short Form 36, Foot and Ankle Disability Index, Short Musculoskeletal Functional Assessment, and American Orthopaedic Foot & Ankle Society ankle-hindfoot score. Surgeries were performed by a nondesign team of orthopedic foot and ankle specialists with total ankle replacement expertise. Statistical analysis was performed by a qualified statistician. At average follow-up of 4.5 years (range, 2-6 years) complete clinical data and radiographs were available for 84 patients; 7 had incomplete data, 1 had died, 4 were withdrawn after enrolling but prior to surgery, and 4 were lost to follow-up.

RESULTS

In all outcome measures, the entire cohort demonstrated statistically significant improvements from preoperative evaluation to most recent follow-up with no statistically significant difference between the 2 groups. Radiographically, tibial lucency/cyst formation was 26.8% and 20.9% for MB-TAR and FB-TAR, respectively. Tibial settling/subsidence occurred in 7.3% of MB-TAR. Talar lucency/cyst formation occurred in 24.3% and 2.0% of MB-TAR and FB-TAR, respectively. Talar subsidence was observed in 21.9% and 2.0% of MB-TAR and FH-TAR, respectively. Reoperations were performed in 8 MB-TARs and 3 FH-TARs, with the majority of procedures being to relieve impingement or treat cysts and not to revise or remove metal implants.

CONCLUSION

With a high level of evidence, our study found that patient-reported and clinical outcomes were favorable for both designs and that there was no significant difference in clinical improvement between the 2 implants. The incidence of lucency/cyst formation was similar for MB-TAR and FH-TAR for the tibial component, but the MB-TAR had greater talar lucency/cyst formation and tibial and talar subsidence. As has been suggested in previous studies, clinical outcomes do not necessarily correlate with radiographic findings. Reoperations were more common for MB-TAR and, in most cases, were to relieve impingement or treat cysts rather than revise or remove metal implants.

LEVEL OF EVIDENCE

Level I, prospective randomized study.

Mid-Term Prospective Clinical and Radiographic Outcomes of a Modern Fixed-Bearing Total Ankle Arthroplasty

The early outcomes of the Salto Talaris® Total Ankle Prosthesis have been promising, but information on its mid-term outcomes is still sparse. The purpose of this study was to evaluate the mid-term clinical and radiographic outcomes of this implant among a prospective cohort of patients who underwent total ankle replacement for various etiologies. Forty-six patients (50 ankles) were consecutively enrolled in the study. Our primary aim was to assess implant survivorship as determined by the removal or revision of the implant metal components or conversion to arthrodesis. Our secondary aim was to gauge patient outcomes by using commonly used outcome scores and assess ankle range of motion using goniometric and radiographic methods. We report 100% survivorship of the implant at a mean follow-up of 4.9 years. Compared with preoperative levels, all clinical outcome scores showed significant improvement at the 1-year, 2-year, and 5-year and longer follow-up. The mean clinical ROM improved from 27.7° ± 10.7° preoperatively to 40.0° ± 12.3° at the 2-year follow-up (p < .001). The mean radiographic ROM improved from 23.0° ± 10.2° preoperatively to 27.2° ± 9.1° at the 2-year follow-up (p = .007). Reoperations or secondary procedures were performed on 6 (12%) ankles, with the most common procedure being gutter debridement for impingement symptoms. The study confirms that the excellent survivorship seen with the implant in the early studies extends to mid-term follow-up as well. Patients could expect to see improvement in pain relief and activity well into 5 years after surgery and retain sufficient ankle range of motion for normal gait.

Outcomes Following Total Ankle Arthroplasty: A Review of the Registry Data and Current Literature

End-stage ankle arthritis has a significant effect on function and quality of life. Total ankle arthroplasty continues to emerge as a safe and effective treatment of ankle arthritis. Ankle arthroplasty preserves motion at the ankle joint, while still achieving the primary goal of pain relief. With encouraging outcomes and improved implant longevity, there has been significant improvement on the results of first-generation implants. Further high-quality studies are required to clarify outcomes post ankle arthroplasty. This article reviews the latest data from national registries and the wider literature to evaluate the current status with outcomes of modern total ankle replacements.

Total Ankle Arthroplasty Survival and Risk Factors for Failure

BACKGROUND

Total ankle arthroplasty (TAA) is an increasingly selected treatment for end-stage ankle arthritis; however, failure and revision of the tibial and talar components remains an issue. Although multiple risk factors have been shown to contribute to early component revision, no study has looked at combining such risk factors into a predictive model that could potentially decrease revision rates and improve implant survival. This study aimed to develop a predictive model for TAA failure based on patient characteristics, patient-reported outcomes (PROs), and immediate postoperative radiographs.

METHODS

A retrospective review of a single-site ankle arthritis database was conducted. All patients with current-generation ankle replacements including the Hintegra and Infinity prostheses implanted between 2004 and 2015 and with complete postoperative radiographs taken between 6 and 12 weeks postoperatively were included. Eight coronal and sagittal radiographic parameters were assessed and performed twice by 2 independent orthopedic surgeons on included TAAs. These radiographic parameters were then analyzed in association with patient demographics and PRO. Advanced statistical methods including survival analysis were used to construct a predictive model for TAA survival. A total of 107 patients were included and analyzed with a median clinical follow-up of 49 months (minimum 24 months).

RESULTS

A predictive model was created, with 4 parameters identified as being statistically associated with TAA metal-component revision: diabetes mellitus, poor baseline Ankle Osteoarthritis Scale (AOS) score, excessively dorsiflexed talar component, and an anteriorly/posteriorly translated talus relative to the tibial axis. The presence of 3 parameters predicted TAA survival of 0.60 whereas presence of all 4 parameters predicted survival of only 0.13 in the period studied.

CONCLUSION

Our predictive model is based on a combination of patient factors, PROs, and radiographic TAA alignment. We believe it can be used by surgeons to predict failure in their TAA patients, thereby optimizing postoperative outcomes by improving patient selection and modifiable outcome-specific parameters.

LEVEL OF EVIDENCE

Level III, retrospective cohort study using prospectively collected data.

Ankle Arthritis

Ankle arthritis is a major source of morbidity impacting a younger working age population than hip and knee arthritis. Unlike the hip and knee, more than 70% of ankle arthritis cases are post-traumatic, with the remainder being inflammatory or primary arthritis. Nonoperative treatment begins with lifestyle and shoe-wear modifications and progresses to bracing, physical therapy, anti-inflammatory medications, and intra-articular injections. Ankle arthrodesis and total ankle arthroplasty are the 2 main surgical options for end-stage ankle arthritis, with debridement, realignment osteotomy, and distraction arthroplasty being appropriate for limited indications.

The HINTEGRA total ankle arthroplasty

Aims

The purpose of this study was to determine the functional outcome and implant survivorship of mobile-bearing total ankle arthroplasty (TAA) performed by a single surgeon.

Patients and Methods

We reviewed 205 consecutive patients (210 ankles) who had undergone mobile-bearing TAA (205 patients) for osteoarthritis of the ankle between January 2005 and December 2015. Their mean follow-up was 6.4 years (2.0 to 13.4). Functional outcome was assessed using the Ankle Osteoarthritis Scale, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, 36-Item Short-Form Health Survey (SF-36) score, visual analogue scale, and range of movement. Implant survivorship and complications were also evaluated.

Results

There were significant improvements in all functional outcome categories between the preoperative and final follow-up assessments (p < 0.001). Patients showed marked improvement in clinical outcomes in terms of pain, function, and quality of life. The overall implant survivorship was 91.7% at a mean follow-up of 6.4 years. In all, 33 major complications were identified with a 15.7% rate, resulting in 12 prosthesis failures (5.7%). Periprosthetic osteolysis (19 cases; 9.0%) was the most frequent complication.

Conclusion

Mobile-bearing TAA resulted in improved functional outcomes, a low major complication rate, and excellent implant survivorship at a mean follow-up of 6.4 years. Cite this article: Bone Joint J 2019;101-B:695–701.

Ankle motion in common yoga poses

BACKGROUND

Motion of the ankle is essential for many yoga poses. An understanding of range of ankle motion during typical yoga poses may help the clinician to understand expected outcomes of patients when returning from ankle surgery or injury to yoga.

METHODS

The biomechanics of twenty healthy active yogis were collected during seven yoga poses that are common within their practices. Motion capture and force plates were used to assess the range of motion and joint moments of the ankle for each pose.

RESULTS

All poses resulted in plantarflexion and external rotation moments at the ankle joints. Joint loading was highest in single leg poses. The arc of motion used by the study participants in the poses was 29° of sagittal motion, 20° of frontal motion and 35° of transverse motion.

DISCUSSION

Ankle motion was evaluated when healthy yogis perform standard poses. These results may help in discussion with patients regarding expected outcomes after ankle injury or surgery.

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.

Recent National Trends and Outcomes in Total Ankle Arthroplasty in the United States

Total ankle arthroplasty (TAA) is an evolving option for treating ankle arthritis. We assessed the national trends in usage and perioperative outcomes of TAA in the United States. International Classification of Diseases, 9th revision (ICD-9), codes were used to search the National Hospital Discharge Survey database for TAA from 1997 to 2010. Patient demographics, comorbidities, hospitalization length, discharge disposition, blood transfusion, lower extremity deep vein thrombosis, pulmonary embolism, and mortality data were gathered. Trends were evaluated using linear regression with Pearson's correlation coefficient, and statistical comparisons were performed using Student's t test and z-test for proportions with significance at p = .05. We identified 120 patients with TAA. TAA demonstrated a positive correlation with time (r = 0.57), significantly increasing from 2.4 cases per 100,000 admissions from 1997 to 2003 to 3.5 cases per 100,000 from 2004 to 2010 (p = .04). The mean age was 57.8 (range 19 to 83) years. The mean number of comorbidities was 4.5 (range 1 to ≥7). Although patient age remained stable (p = .21), the mean number of comorbidities significantly increased from 4.0 from 1997 to 2003 to 4.8 from 2004 to 2010 (p = .02); 8 patients (6.7%) had diabetes, 71 (59.2%) had primary osteoarthritis, and 35 (29.2%) had posttraumatic arthropathy. The mean length of stay significantly decreased from 3.1 to 2.3 days (p = .03). Three patients (2.5%) required a blood transfusion. No deep vein thrombosis or PE was diagnosed. No patients died during the operative admission; 95 patients (87%) were discharged home and 14 (13%) required a skilled rehabilitation facility. Discharge patterns showed no significant change with time (p = .59). Usage of TAA in the United States has increased nearly 50% over the past 14 years. TAA was associated with shorter hospitalization, infrequent rehabilitation facility requirements, and few perioperative complications.

Clinical and Radiological Outcomes of Transfibular Total Ankle Arthroplasty

BACKGROUND:

Ankle arthritis is a highly limiting pathology that causes pain and functional limitation with subsequent deterioration of quality of life. With recent advances in surgical instrumentation and techniques, prosthetic replacement of the ankle has proven to be a valid alternative to arthrodesis with comparable outcomes. The purpose of this study was to evaluate clinical and radiological findings in a transfibular total ankle replacement with follow-up of at least 2 years.

METHODS:

This prospective study included 89 patients who underwent transfibular total ankle arthroplasty from May 2013 to February 2016. The mean age was 53.2 ± 13.5 years. All patients were followed for at least 24 months postoperatively with an average follow-up of 42.0 ± 23.5 months. Patients were assessed clinically and radiographically preoperatively and at 6, 12, and 24 months postoperatively.

RESULTS:

At 24 months postoperatively, patients demonstrated statistically significant improvement in the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score from 33.8 ± 14.3 to 88.5 ± 6.6 ( P < .001), visual analog scale (VAS) from 80.5 ± 17.0 to 14.1 ± 9.2 ( P < .001), and Short Form-12 Physical and Mental Composite Scores from 29.9 ± 6.7 and 43.3 ± 8.6 to 47.0 ± 7.6 and 53.3 ± 8.1, respectively ( P < .001). In addition, ankle dorsiflexion and plantarflexion improved from 6.2 ± 5.5 and 9.6 ± 5.8 degrees to 24.2 ± 7.9 and 18.1 ± 7.6 degrees, respectively ( P < .001). Radiographically, patients demonstrated maintained neutral alignment of the ankle at 24 months. No patient demonstrated any radiographic evidence of tibial or talar lucency at final follow-up. Seven patients underwent reoperation for removal of symptomatic hardware (6 fibular plates, 1 syndesmotic screw); 2 patients experienced delayed wound healing. The first one was treated with plate removal and flap coverage. The second one required fibular plate removal. One patient developed a postoperative prosthetic infection requiring operative debridement, removal of implants, and placement of an antibiotic spacer.

CONCLUSION:

This study found that transfibular total ankle replacement was a safe and effective option for patients with ankle arthritis resulting in improvements in patient-reported outcomes, range of motion, and radiographic parameters. However, further studies are required to determine the mid- and long-term performance of these implants.

LEVEL OF EVIDENCE:

Level IV, case series.

Improvement of Outcomes During the First Two Years Following Total Ankle Arthroplasty

BACKGROUND

Many studies of total ankle arthroplasty (TAA) have focused on the range of motion and functional outcomes at the time of intermediate-term follow-up. The purpose of our study was to analyze the progression of ankle hindfoot range of motion and patient-reported measures through the first 2 years following TAA.

METHODS

The charts of 134 patients who had been treated with a TAA by a single surgeon were retrospectively reviewed, and 107 (109 TAAs) were included in the study. The overall range of motion in the sagittal plane was measured as the change in the position of the tibia relative to the floor on dedicated weight-bearing lateral radiographs made with the ankle in maximum plantar flexion and dorsiflexion preoperatively and at 3 months, 6 months, 1 year, and 2 years postoperatively. In addition, patients completed a visual analogue scale (VAS) for pain, the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sports Subscales, and the Short Form-12 (SF-12) Physical (PCS) and Mental (MCS) Component Summary scores at each time interval.

RESULTS

The mean overall range of motion in the sagittal plane was 20.7° preoperatively and improved to 28.3°, 34.3°, 33.3°, and 33.3° at 3 months, 6 months, 1 year, and 2 years, respectively (p < 0.001). At each postoperative time point, the median VAS score was improved (p < 0.001) compared with the preoperative VAS score. Similarly, the FAAM and SF-12 scores were improved, compared with the preoperative score, at 6 months and later (p < 0.001). An increased range of motion correlated with a lower VAS score preoperatively (ρ = -0.31, p = 0.035) and at 1 year (ρ = -0.36, p = 0.003) postoperatively. An increased range of motion correlated with a higher FAAM ADL score at 3 months (ρ = 0.50, p = 0.012), 1 year (ρ = 0.26, p = 0.040), and 2 years (ρ = 0.39, p = 0.003) postoperatively.

CONCLUSIONS

Patients who underwent TAA had improvement, compared with preoperatively, in the overall sagittal plane range of motion up to 6 months and maintained improvement in pain and function scores up to 2 years. Pain scores remained improved throughout the 2-year follow-up period. A better range of motion was correlated with less pain as measured with the VAS. An increased range of motion postoperatively was correlated with better function as measured with the FAAM.

LEVEL OF EVIDENCE

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

Short-Term Complications, Reoperations, and Radiographic Outcomes of a New Fixed-Bearing Total Ankle Arthroplasty

BACKGROUND

With the increasing use of total ankle arthroplasty (TAA), new implants with varied configurations are being developed every year. This study aimed to assess the early complications, reoperations, and radiographic and clinical outcomes of the Infinity TAA. To date, clinical results of this novel implant have not been published.

METHODS

A retrospective analysis of 64 consecutive ankles that underwent a primary Infinity TAA from July 2014 to April 2016 was performed. Patients had an average follow-up of 24.5 (range, 18-39) months. Medical records were reviewed to determine the incidence of complications, reoperations, and revisions. Radiographic outcomes included preoperative and postoperative tibiotalar alignment, tibial implant positioning, the presence of periprosthetic radiolucency and cysts, and evidence of subsidence or loosening. Additionally, patient-reported outcomes were analyzed with the Foot and Ankle Outcome Score (FAOS).

RESULTS

Survivorship of the implant was 95.3%. Fourteen ankles (21.8%) presented a total of 17 complications. A total of 12 reoperations were necessary in 11 ankles (17.1%). Revision surgery was indicated for 3 ankles (4.7%) as a result of subsidence of the implant. Tibiotalar coronal deformity was significantly improved after surgery ( P < .0001) and maintained during latest follow-up ( P = .81). Periprosthetic radiolucent lines were observed around the tibial component in 20 ankles (31%) and around the talar component in 2 ankles (3.1%). A tibial cyst was observed in 1 ankle (1.5%). Outcome scores were significantly improved for all FAOS components analyzed ( P < .0001), from 39.0 to 83.3 for pain, from 34.0 to 65.2 for symptoms, from 52.3 to 87.5 for activities of daily living, and from 15.7 to 64.2 for quality of life.

CONCLUSION

Most complications observed in the study were minor and successfully treated with a single reoperation procedure or nonoperatively. Failures and radiographic abnormalities were most commonly related to the tibial implant. Further studies with longer follow-up are needed to evaluate the survivorship of the tibial implant in the long term.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Obesity in Elective Foot and Ankle Surgery

Obesity is a global health problem with significant economic and health consequences. There is very little literature in regards to obesity and its effect on foot and ankle surgery, and to the author's knowledge, there has been no consolidated review on this subject to date. The purpose of this article is to provide a comprehensive review as it pertains to foot and ankle surgery, with hopes of improving surgeon decision making, mitigating risk, and providing better outcomes for patients. A better understanding of the effects of obesity also allows for improved prognostic performance.

Ankle arthroplasty: A review and summary of results from joint registries and recent studies

Total ankle arthroplasty offers a reasonable alternative to ankle arthrodesis in carefully selected patients.

It is debatable whether rheumatoid arthritis patients have better outcomes compared with those who have ankle arthroplasty for either primary osteoarthritis or post-traumatic arthritis.

Aseptic loosening and infection are the most common complications requiring revision.

It is worth noting that some of the best survival rates are seen in the surgeon-designer case series.

The uncemented mobile or fixed bearing prostheses have better outcomes compared with their older counterparts.

There is no convincing evidence to suggest superiority of one design over another among the currently available prostheses.

Ankle arthroplasty surgery has a steep learning curve; the prosthesis choice should be driven by the surgeon’s training and experience.

Cite this article: EFORT Open Rev 2018;3:391-397. DOI: 10.1302/2058-5241.3.170029

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.

A three-year prospective comparative gait study between patients with ankle arthrodesis and arthroplasty

BACKGROUND

End-stage ankle arthritis is a debilitating condition that often requires surgical intervention after failed conservative treatments. Ankle arthrodesis is a common surgical option, especially for younger and highly active patients; however, ankle arthroplasty has become increasingly popular as advancements in implant design improve device longevity. The longitudinal differences in biomechanical outcomes between these surgical treatments remain indistinct, likely due to the challenges associated with objective study of a heterogeneous population.

METHODS

Patients scheduled for arthroplasty (n = 27) and arthrodesis (n = 20) were recruited to participate in this three-year prospective study. Postoperative functional outcomes were compared at distinct annual time increments using measures of gait analysis, average daily step count and survey score.

FINDINGS

Both surgical groups presented reduced pain, improved survey scores, and increased walking speed at the first-year postoperative session, which were generally consistent across the three-year follow-up. Arthrodesis patients walked with decreased sagittal ankle RoM, increased sagittal hip RoM, increased step length, and increased transient force at heel strike, postoperatively. Arthroplasty patients increased ankle RoM and cadence, with no changes in hip RoM, step length or heel strike transient force.

INTERPRETATION

Most postoperative changes were detected at the first-year follow-up session and maintained across the three-year time period. Despite generally favorable outcomes associated with both surgeries, several underlying postoperative biomechanical differences were detected, which may have long-term functional consequences. Furthermore, neither technique was able to completely restore gait biomechanics to the levels of the contralateral unaffected limb, leaving potential for the development of improved surgical and rehabilitative treatments.

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.

Short-term Clinical and Radiographic Results of the Salto Mobile Total Ankle Prosthesis

BACKGROUND

The mobile-bearing Salto total ankle prosthesis has been reported to have promising outcomes. However, clinical reports on this prosthesis are few, and most have been published by the inventors and disclosed consultants.

METHODS

We retrospectively reviewed 59 patients who received Salto prosthesis unilaterally. The average follow-up was 35.9 (range, 6-56) months. Clinical and radiologic results were evaluated. Clinical results were evaluated according to visual analog scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, Ankle Osteoarthritis Scale (AOS) pain and disability score, and ankle range of motion (ROM) in dorsiflexion/plantarflexion. In the radiographic evaluation, we measured the tibial angle (TA), talar angle (TAL), tibial slope, and talocalcaneal angle (TCA) on weightbearing radiographs.

RESULTS

By the last follow-up, 7 of 59 patients (11.9%) had undergone reoperation, and 3 of 59 implants (5.1%) had been removed. The prosthesis survival was 94.9% (95% CI, 89.1%-100%). With any reoperation as the endpoint of follow-up, the clinical success rate was 88.1% (95% CI, 79.4%-96.9%). The mean postoperative visual analog scale score, AOFAS ankle-hindfoot score, and Ankle Osteoarthritis Scale pain and disability score improved significantly ( P < .001). The ankle range of motion also improved from preoperative 33.4 ± 16.6 to 40.3 ± 15.5 postoperatively ( P < .001); however, there was no statistically significant change in plantarflexion ( P = .243). Radiolucent areas and osteolysis were found in 28 (47.5%) and 27 (45.8%) patients, respectively. Heterotopic ossification was observed in 13 patients (22.0%).

CONCLUSIONS

In this series, early clinical and radiographic outcomes of this prosthesis were promising. We believe the early radiolucent lines were probably due to the gap at the implant and bone interface, and they disappeared at the time of osseous integration. However, longer follow-up is necessary to determine the long-term durability and survivorship of this implant, particularly given the high incidence of postoperative osteolysis.

LEVEL OF EVIDENCE

Level IV, case series.

Single-Surgeon Experience and Complications of a Fixed-Bearing Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) has historically resulted in inferior survivorship rates compared with total hip and knee arthroplasty, because of technical issues unique to ankle anatomy. In this study, a single-surgeon series of intra- and postoperative complications as well as resultant reoperations/revisions of the Tornier Salto Talaris, a fixed-bearing TAA prosthesis, were reviewed.

METHODS

Medical records from index procedure to latest follow-up of primary TAA were reviewed. Complications were categorized according to the Glazebrook classification; additional complications were documented. Concurrent procedures were recorded, and radiographs were analyzed for alignment, subsidence, and cyst formation. Time to complication onset and learning curve analyses were performed. One hundred four Salto Talaris TAA prostheses (96 patients), with an average follow-up of 46 months, were included.

RESULTS

Thirty-five complications were identified in 32 ankles with a 34% complication rate, resulting in 11 reoperations (5 TAA revisions). Technical error (n = 12), wound healing (n = 9), and aseptic loosening (n = 4) were the most common complications, and there were no statistically significant differences in demographics or follow-up duration between cases with versus without complications. In both the cohorts with and without complications, there were moderate, negative correlations between radiographically observed keel osteopenia and lucency (ρ = -0.548, P = .00125, and ρ = -0.416, P = .000303, respectively); also, in the complication cohort, a weak, positive correlation between subsidence and lucency (ρ = 0.357, P = .0450) was found.

CONCLUSION

Salto Talaris TAA survivorship and reoperation rates in our series were comparable with previous reports, using either the same or similar mobile-bearing prostheses; new information regarding complication, radiographic, and learning curve analyses was presented.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

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.

Midterm Results of the Salto Talaris Total Ankle Arthroplasty

BACKGROUND

The Salto Talaris total ankle replacement is a modern fixed-bearing implant used to treat symptomatic ankle arthritis with the goals of providing pain relief, restoring mechanical alignment, and allowing motion of the ankle joint. The goal of this study was to report the midterm clinical results of one of the largest cohort of patients in the United States who underwent ankle replacement with this prosthesis.

METHODS

This is a review of patients with a minimum of 5 years up to 10 years' follow-up. At the preoperative visit and each annual assessment, patients rated their current level of pain using the visual analog score (VAS) and reported their functional level using the American Orthopaedic Foot & Ankle (AOFAS) ankle-hindfoot scores, the Short Musculoskeletal Function Assessment (SMFA), and the Short Form-36 (SF-36) Health survey. These scores were analyzed to assess differences between their levels preoperatively, 1 year postoperatively, and at their most recent follow-up. Criteria for failure was defined as revision requiring exchange or removal of the metallic components for any reason. We identified 106 patients having a Salto Talaris total ankle replacement. Seventy-two patients (mean age, 61.9 years) met the minimum requirement for follow-up (range 60-115 months, mean 81.1 months).

RESULTS

Significant improvements were seen in the VAS, SMFA, AOFAS score, and SF-36 from preoperatively to their final follow-up ( P < .001). Survivorship was 95.8% for those with at least 5-year follow-up, with 2 patients undergoing revision arthroplasty for aseptic loosening and a third patient scheduled for revision for a chronic wound infection. Fourteen patients (19%) required an additional surgery for a total of 17 additional operative procedures on the ipsilateral ankle or hindfoot.

CONCLUSION

Patients undergoing total ankle arthroplasty with the Salto Talaris prosthesis continued to show significant improvements in pain and functional outcomes at midterm follow-up. This prosthesis has shown to be an effective treatment option with durable results.

LEVEL OF EVIDENCE

Level IV, therapeutic, case series.

Role of Total Ankle Arthroplasty in Stiff Ankles

BACKGROUND

The decision tree for the operative treatment of end-stage ankle arthritis involves either ankle arthrodesis (AA) or total ankle arthroplasty (TAA). Although both have documented success providing diminished pain, improved patient-centered outcomes, and improved objective measures of function, arthroplasty is unique in its ability to preserve motion at the tibiotalar joint. Arthroplasty procedures are normally thought of as a motion-sparing surgery rather than a motion-producing procedure, which may limit its success in patients with stiff ankles. Our hypothesis was that there would be improvements in parameters of gait even in patients with a low degree of preoperative total sagittal range of motion.

METHODS

A retrospective review was conducted on patients who underwent total ankle arthroplasty with greater than 1-year follow-up. Seventy-six patients were available who underwent isolated TAA for end-stage ankle arthritis with greater than 1-year follow-up. Patient demographics and preoperative and postoperative gait analyses were evaluated. Using a linear regression model, the effect sizes for the variables of age, gender, BMI, preoperative diagnosis, and preoperative total sagittal range of motion were calculated. Multivariate analysis was used to determine the influence each individual variable had on the many parameters of preoperative gait, postoperative gait, and change in gait after surgery. A post hoc analysis was conducted in which patients were divided into 4 quartiles according to preoperative range of motion. A 1-way analysis of variance (ANOVA) was used to compare improvement in parameters of gait for the 4 subgroups.

RESULTS

Although a greater degree of preoperative sagittal range of motion was predictive of greater postoperative sagittal range of motion, patients with limited preoperative range of motion experienced a greater overall improvement in range of motion, and clinically meaningful absolute improvements in range of motion, and other parameters of gait. The post hoc analysis demonstrated that patients in the lowest quartile of preoperative motion had both statistically and clinically significant greater improvements across numerous parameters of gait, although the absolute values were lower than in the patients with higher preoperative ROM. Age, gender, BMI, and preoperative diagnosis did not correlate with changes in parameters of gait after total ankle arthroplasty.

CONCLUSION

Preoperative range of motion was predictive of overall postoperative gait function. On one hand, a low preoperative range of motion resulted in a lower absolute postoperative function. On the other hand, patients with stiff ankles preoperatively had a statistically and clinically greater improvement in function as measured by multiple parameters of gait. This suggests that total ankle arthroplasty can offer clinically meaningful improvement in gait function and should be considered for patients with end-stage tibiotalar arthritis even in the setting of limited sagittal range of motion.

LEVEL OF EVIDENCE

Level IV, retrospective case series.