Two-Year Outcomes After Total Ankle Replacement With a Novel Fixed-Bearing Implant

Two-Year Outcomes After Total Ankle Replacement With a Novel Fixed-Bearing Implant By a Single Surgeon Non-Inventor

Total ankle arthroplasty continues to gain popularity amongst surgeons and patients as an alternative to arthrodesis. Historically the designs of early implants were plagued with complications and frequently abandoned. Since that time the procedure and materials have undergone significant advancements in both surgical approach as well as design and function of the available implants. In this study, 40 consecutive patients who received a semiconstrained prosthesis with a unique fixed-bearing polyethylene insert were identified. Minimum follow-up was 2 y. Demographic, social, and past medical data was retrospectively reviewed. Concomitant procedures were also recorded. Radiographic analysis included lateral ankle radiograph postoperative range of motion (ROM) with maximum dorsiflexion and maximum plantarflexion weight bearing at the most recent clinic visit. Clinical outcomes included VAS, FFI, and AOFAS scores. Lateral radiographs taken in the office at a minimum 2-y follow-up showed mean maximum dorsiflexion of 11.8 degrees and plantarflexion of 13.9 degrees. VAS, FFI, and AOFAS scores improved from 8.1, 92.9, and 44.8 to 1.4, 15.3, and 90.1 postoperatively, respectively. A total of 2.5% (n = 1) required revision surgery for poly failure, and 5.0% (n = 2) underwent local wound care in the office setting postoperatively and healed without complications. Overall survivorship was 97.5% at the minimum follow-up of 2 y. In conclusion, similar studies have reported survivorship from 90% to 100% with modern ankle implants in short to mid-term follow-up. Although this is a small sample size, our data shows a 97.5% survivorship at 2 y postoperatively with favorable patient-reported statistically significant functional outcome scores, and ankle range of motion consistent with existing literature.

Outcomes After Total Ankle Arthroplasty in Patients Aged ≤50 Years at Midterm Follow-up

BACKGROUND

Ankle arthritis differs from arthritis of the hip and knee in that 80% is posttraumatic and thus often occurs in a younger patient population. The literature supporting total ankle arthroplasty (TAA) in younger patients has increased over recent years and has bolstered the argument that in the short term, TAA in younger patients has successful outcomes that are comparable to older, lower-demand patients.The purpose of our study was to evaluate patient-reported outcomes (PROs) and implant survivorship at midterm after primary TAA in patients ≤ 50 years of age at the time of surgery.

METHODS

A retrospective chart review was conducted of patients ≤ 50 years of age who underwent primary TAA at a single institution from 2000 to 2017. Patient demographics, outcome measures, and complications were recorded. All patients had a minimum clinical follow-up of 5 years. PRO measures were evaluated at preoperative, 1-year postoperative, and final follow-up visits. Paired t tests were performed to compare individual patient changes in PROs from preoperative. Implant survivorship was evaluated based on need for revision of either the tibial or talar component. The need for additional surgery related to the TAA was also evaluated.

RESULTS

A total of 58 patients were included. The average age at the time of the index surgery was 43.3 years (range 22-50 years). All patients had a minimum follow-up of 5 years with a mean follow-up of 8.8 years. A total of 11 patients required additional surgery related to their TAA. Six patients (10.3%) required bone grafting of peri-implant cysts, 3 patients (5.2 %) required gutter debridement, and 1 patient underwent complete revision of metal components. Mean visual analog scale, 36-item Short Form Health Survey, Short Musculoskeletal Function Assessment, and American Orthopaedic Foot & Ankle Society hindfoot scores significantly improved from preoperative to 1-year postoperative and final postoperative follow-up.

CONCLUSION

The patients aged ≤50 years treated with a TAA whom we have been able to observe for a minimum of 5 years showed generally maintained improvement in functional scores and thus far have had a relatively low rate of secondary surgeries.Level of Evidence:Level III, retrospective cohort study.

Two to Five-Year Outcomes of Total Ankle Arthroplasty with the Infinity Fixed-Bearing Implant: A Concise Follow-up of a Previous Report

LEVEL OF EVIDENCE

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

Early outcomes of the Exactech Vantage fixed-bearing total ankle replacement

Aims

The Vantage Total Ankle System is a fourth-generation low-profile fixed-bearing implant that has been available since 2016. We aimed to describe our early experience with this implant.

Methods

This is a single-centre retrospective review of patients who underwent primary total ankle arthroplasty (TAA) with a Vantage implant between November 2017 and February 2020, with a minimum of two years' follow-up. Four surgeons contributed patients. The primary outcome was reoperation and revision rate of the Vantage implant at two years. Secondary outcomes included radiological alignment, peri-implant complications, and pre- and postoperative patient-reported outcomes.

Results

There were 168 patients (171 ankles) included with a mean follow-up of 2.81 years (2 to 4.6) and mean age of 63.0 years (SD 9.4). Of the ten ankles with implant failure (5.8%), six had loosening of the tibial component. In the remaining four failed implants, one was due to periprosthetic joint infection (PJI), one was due to loosening of the talar component, and two were due to loosening of both the tibial and talar components. Seven patients underwent reoperation: irrigation and debridement for superficial infection (n = 4); bone grafting for cysts (n = 2); and open reduction internal fixation (n = 1). Asymptomatic peri-implant lucency/subsidence occurred in 20.1% of ankles, with the majority involving the tibial component (n = 25). There were statistically significant improvements in PROMs in all domains.

Conclusion

Short-term results of this implant demonstrate early survival comparable to the reported survivorship of similar low-profile, non-stemmed implants. Radiological lucency occurred more commonly at the tibial component, and revisions occurred primarily due to loosening of the tibial component. Further research is needed to evaluate longer-term survivorship.

Randomized Controlled Trial Comparing Early Mobilization vs Six Weeks of Immobilization in a Walking Cast Following Total Ankle Replacement

Rehabilitation for patients after total ankle replacement traditionally involves weeks of immobilization in a plaster cast followed by progressive mobilization. In a small randomized trial, we compared teh outcomes of patients who received a 3-component cementless, unconstrained, mobile-bearing prosthesis and were initially immobilised in a plaster cast for 6 weeks to thoese who received the same prosthesis but were allowed to mobilise early. Gait, clinical, patient-reported, and radiologic outcomes were measured. The study included 20 patients, 10 in the plaster cast group and 10 in the early mobilization group, and the demographics of the groups did not differ significantly. All patients were followed-up for 24 months. There were no significant differences between the 2 groups 2 years after surgery in ankle dorsiflexion, spatiotemporal gait characteristics, American Orthopaedic Foot and Ankle Society ankle-hindfoot scores, Timed Up and Go Test times, WOMAC (pain, stiffness, function) scores, SF-36 (quality-of-life) scores, or patient satisfaction (pain relief, daily-living, recreational activities, and overall) (all p > .05). Bone mineral density decrease of the medial malleolus and increase at middle tibia, calculated with DEXA scans, was significantly better in early mobilization than plaster cast group at one and 2 years postoperatively, but this was also the case preoperatively. The lack of differences in outcomes suggests that early ankle mobilization may be a safe and reliable method to enhance recovery following ankle arthroplasty with a 3-component cementless, unconstrained, mobile-bearing prosthesis. Compared to traditional plaster casting, patients who are engaged in early mobilization after arthroplasty may enjoy similar functional, mobility, quality-of-life, pain relief, activity level, and satisfaction outcomes.

Early-Term Results of the Cadence Total Ankle Prosthesis: An European Noninventor Study

BACKGROUND

Although considerable literature can be found on the outcome of total ankle replacement (TAR), only a few studies have reported the results of the fixed-bearing Cadence prosthesis. This noninventor study reports a consecutive series of 60 Cadence TAR systems with a mean of 2.9 years' follow-up, focusing on clinical and radiographic outcomes and early complications. This study is the first to assess true postoperative radiographic ankle prosthesis range of motion (ROM) and to report an unanticipated serious adverse device effect.

METHODS

Sixty patients who underwent primary TAR with the Cadence prosthesis between July 2016 and July 2019 were clinically and radiographically evaluated preoperatively and at last follow-up after the procedure. Revisions, additional procedures, implant failure, and complications were reported according to the classifications of Vander Griend and Glazebrook. Radiographic outcomes included radiographic TAR ROM, bone-implant interface, and alignment parameters.

RESULTS

The survival rate of the prosthesis was 98.3%. The mean radiographic ankle ROM at the last follow-up was 24 degrees (9 degrees of dorsiflexion and 15 degrees of plantarflexion). The coronal and sagittal alignment of TAR was 90.8 degrees and 3.9 degrees, respectively. Bone-implant interface analysis revealed osteolysis in 9 ankles (15%) and radiolucent lines in 33 ankles (55%) occurring at both component interfaces. Intraoperative complications were 3 periprosthetic malleolar fractures (5%). Five talar implant fractures (implant failure of 8.3%) were observed, and 1 unexplained persistent pain that required a conversion from TAR to a tibiotalocalcaneal arthrodesis.

CONCLUSION

Clinical, radiograph ROM, implant position outcomes, and survival rate at an early-term follow-up of 2.9 years were similar to those reported in recent Cadence studies. However, this study reports 5 unanticipated talar implant fractures and a high rate of posterior radiolucent lines.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Complications, Reoperations, and Patient-Reported Outcomes Following a 2-Stage Revision Total Ankle Arthroplasty for Chronic Periprosthetic Joint Infections

BACKGROUND

As total ankle arthroplasty (TAA) becomes more common, chronic periprosthetic joint infections (PJIs) will be encountered more frequently. No studies have reported on patient-reported outcomes following a 2-stage revision procedure for a chronic PJI after a TAA. The primary purpose of this study was to investigate postoperative clinical outcomes at a minimum of 2 years following a 2-stage revision TAA for chronic PJI.

METHODS

Patients who underwent a 2-stage revision TAA for a chronic PJI (>4 weeks after a primary TAA) between January 2010 and December 2019 were eligible to be included in this study. Chronic PJI was defined as a sinus tract that directly communicated with the prosthesis or the same organism identified in ≥2 synovial fluid samples. Twelve patients were eligible to be included in this case series. One patient died prior to 2-year follow-up, which left 11 patients available for analysis. All 11 patients underwent reimplantation. The data were found not to be normally distributed; therefore, medians and interquartile ranges (IQRs) were reported.

RESULTS

At a median of 3.0 years (IQR 2.0-4.0 years) following the second stage of their revision arthroplasty, the median Foot and Ankle Ability Measure (FAAM) Activities of Daily Living and Sports scores were 60.7 (IQR 52.4, 79.8) and 31.3 (IQR 9.4, 40.6), respectively. At final follow-up, 10 patients (90.9%) were ambulating with a TAA in place. Seven patients (63.6%) required a reoperation including 1 patient who underwent a below-knee amputation.

CONCLUSION

Our study suggests that a 2-stage revision TAA may be an option for patients with a chronic PJI. However, patients who undergo a 2-stage revision TAA for a chronic PJI have lower than previously published 2-year FAAM scores and a high rate of reoperation.

LEVEL OF EVIDENCE

Level IV, case series.

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.

Decreased Mechanical Work Demand in the Chopart Joint After Total Ankle Replacement

BACKGROUND

The success of total ankle replacement (TAR) must be based on restoring reasonable mechanical balance with anatomical structures that can produce mechanical joint work through elastic (eg, tendons, fascia) or viscoelastic (eg, heel pad) mechanisms, or by active muscle contractions. Yet, quantifying the work distribution across the affected joint and the neighboring foot joints after TAR is lacking. Therefore, the objective of this study was to investigate if there is a change in the joint work distribution across the Ankle, Chopart, Lisfranc and Metatarsophalangeal joints during level walking before and after patients undergo TAR.

METHODS

Fifteen patients with end-stage ankle osteoarthritis scheduled for primary TAR for pain relief were recruited and peer-matched with a sample of 15 control subjects. All patients underwent a 3D gait analysis before and after surgery, during which a kinetic multisegment foot model was used to quantify intersegmental joint work.

RESULTS

The contribution of the Ankle joint (P = .007) to the total foot and ankle positive work increased significantly after TAR. In contrast, a significant decrease in the contribution to the total foot and ankle joint positive work (P < .001) were found at the Chopart joint after TAR. The foot joints combined produced a significant increase in a net mechanical work from +0.01 J/kg before surgery to +0.05 J/kg after TAR (P = .006).

CONCLUSION

The findings of this study corroborate the theoretical rationale that TAR reduces significantly the compensatory strategy in the Chopart joint in patients with end-stage ankle osteoarthritis after TAR. However, the findings also showed that the contribution of the ankle joint of patients after TAR to the total foot and ankle joint positive work remained impaired compared to the control group.

Outcomes of trabecular metal total ankle replacement: a longitudinal observational cohort study of 239 consecutive cases from the Swedish Ankle Registry

BACKGROUND AND PURPOSE

Information on outcomes after some modern total ankle replacement (TAR) designs is scarce. We therefore examined outcomes after trabecular metal (TM) TAR in Sweden by use of data from the national registry.

PATIENTS AND METHODS

On December 31, 2020, 239 primary TM TARs had been reported to the Swedish Ankle Registry. We analyzed prosthesis survival probability, using exchange or permanent extraction of components as endpoint for 239 protheses with mean follow-up of 2.2 years (0.1-6.6), risk of revision, as well as patient-reported outcome measures (SEFAS/EQ-5D/EQ-VAS) and satisfaction with surgery.

RESULTS

7/239 prostheses (3%) had been revised by December 31, 2020. We found an overall prosthesis survival probability of 95% (95% CI 89-98) after 3 years. 2 years after surgery 81% of the answering patients were satisfied or very satisfied with surgery and patients reported median SEFAS 36 (max 48), EQ-5D 0.90 (max 1), and EQ-VAS 80 (max 100).

INTERPRETATION

We found short- to mid-term outcomes after TM TAR to be at least as good as after other TAR designs regarding prosthesis survival and patient-reported satisfaction.

Short-Term Complications and Outcomes of the Cadence Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) is an increasingly popular option for the operative treatment of ankle arthritis. The Cadence TAA entered clinical use in 2016 and was designed to address common failure modes of prior systems. We report early complications and radiographic and clinical outcomes of this total ankle system at a minimum of 2 years of follow-up.

METHODS

We performed a retrospective review of a consecutive cohort of patients undergoing primary Cadence TAA by a single surgeon from 2016 to 2017. Complications and reoperations were documented using the American Orthopaedic Foot & Ankle Society (AOFAS) TAA reoperation coding system. Patients completed the Foot and Ankle Ability Measure (FAAM) Activities of Daily Living (ADL) and Sport subscales, SF-12 Mental (MCS) and Physical (PCS) Component Summaries, and visual analog scale (VAS) pain rating (0-100). Radiographic evaluation was performed to assess postoperative range of motion (ROM) of the sole of the foot relative to the long axis of the tibia, alignment, and implant complications.

RESULTS

Fifty-eight patients with a mean age of 63.3 years and mean body mass index of 31.9 kg/m² were included. Twelve of 58 patients (20.7%) underwent an additional procedure(s) within 2 years, including 3 (5.2%) who required removal of one or both components, 2 for infection and 1 for osteolysis. Forty-three patients were followed for a minimum of 2 years with radiographic imaging; 1 patient's (2.3%) radiographs had signs of peri-implant osteolysis, with no cases demonstrating loosening or subsidence. FAAM-ADL, FAAM-Sport, SF-12 PCS, and VAS pain scores all improved at a mean of 27.4 months postoperatively, with mean score changes (± SD) of 16.3 (± 22.0), 25.3 (± 24.5), 6.0 (± 11.1), and -32.3 (± 39.8), respectively. Radiographic analysis revealed that average coronal alignment improved from 6.9 degrees from neutral preoperatively to 2.3 degrees postoperatively. The average ROM of the foot relative to the tibia was 36.5 degrees total arc of motion based on lateral radiographs.

CONCLUSION

Early experience with this 2-component total ankle replacement was associated with a high component retention rate, improved coronal plane alignment, good postoperative ROM, radiographically stable implants, and improved patient function.

LEVEL OF EVIDENCE

Level IV, case series.