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

Implant Choice May Reduce the Risk of Early Mechanical Failure in Total Ankle Replacement

BACKGROUND

Total ankle replacements (TARs) have rapidly advanced in terms of volume, technique, design, and indications. However, TARs are still at risk for early mechanical failure and revision. Prior studies have investigated potential risk factors for failure, but have been limited to smaller series or older implants. This study sought to identify risk factors for early mechanical failure in modern TAR.

METHODS

This is a retrospective study of a single-institution registry. Five surgeons contributed cases involving patients who underwent a primary TAR with any implant. Implants were grouped on the basis of the type of fixation. The primary outcome was early mechanical failure (revision with component removal for a non-infectious etiology, that is, subsidence, aseptic loosening, and/or malalignment). Logistic regression determined the effects of age, weight, hindfoot arthrodesis, implant type, and radiographic deformity on failure.

RESULTS

The 731 included patients had a mean follow-up of 2.7 years. Ten percent (71 patients) had hindfoot arthrodesis. There were 33 mechanical failures (4.5%) at a mean of 1.7 years after the index surgical procedure. Our model demonstrated that hindfoot arthrodesis was associated with 2.7 times greater odds of failure (p = 0.045), every 10 kg of body weight increased the odds of tibial-sided failure by 1.29 times (p = 0.039), and implants with more extensive tibial fixation (stems or keels) lowered the odds of tibial failure by 95% (p = 0.031).

CONCLUSIONS

In patients with uncontrollable risk factors (hindfoot arthrodesis) or risk factors that may or may not be modifiable by the patient (weight), implants with more robust tibial fixation may be able to reduce the risk of early mechanical failure. Further research is warranted to support efforts to decrease early failure in TAR.

LEVEL OF EVIDENCE

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

Early results of combined total ankle total talus replacement in the revision setting

BACKGROUND

Revision of failed total ankle replacement (TAR) is challenging and associated with increased morbidity. Given the increased popularity of TAR in treating end-stage ankle arthritis (ESAA), viable revision options are needed. The objective of this case series is to present a minimum 2-year clinical and radiographic outcomes of patient-specific custom 3D-printed total ankle total talus (TATR) prostheses in this unique subset of patients.

METHODS

19 participants with ESAA and failed primary TAR who underwent TATR by a single surgeon at our institution from 2019 to 2021 were retrospectively identified. All participants were indicated for revision of primary STAR implant (Stryker, Kalamazoo, MI) and underwent replacement with 3D-printed titanium implants based on preoperative CT analysis (Additive Orthopaedics, Little Silver, NJ). Custom components included a mobile-bearing total talus and stemmed tibial system, performed through an anterior approach. Pre- and postoperative patient-reported outcomes were assessed using the Patient Reported Outcomes Measurement Information System (PROMIS). Pre- and postoperative implant alignment was assessed using medial distal tibial angle (MDTA) and tibiotalar angle (TTA) on anteroposterior, and sagittal tibial angle (STA) on lateral weight-bearing plain films.

RESULTS

The average patient age was 60.6 (range, 39-77) years, with an average follow-up of 37.9 (range, 25.3-57.5) months. There was statistically significant improvement in all PROMIS domains. Short-term survivorship was 100%, with two participants (11.0%) requiring reoperation for postoperative complications: one underwent open reduction internal fixation of the tibia for a periprosthetic fracture, and another underwent medial gutter debridement and tarsal tunnel release for recurrent pain. There were no significant differences in pre- versus postoperative radiographic alignment measured by MDTA (89.9 vs 86.4), TTA (89.7 vs 88.1), or STA (85.2 vs 85.3).

CONCLUSION

Custom 3D-printed TATR is a promising option for revision TAR. There was significant short-term improvement in pain and physical function, with excellent short-term survivorship and an acceptable postoperative complication rate.

Revision Total Ankle Arthroplasty Using the INBONE II System

BACKGROUND

The utilization of total ankle arthroplasty (TAA) for managing severe ankle osteoarthritis has become increasingly common, leading to a higher occurrence of revision TAA procedures because of failure of primary TAA. This study aims to examine the clinical results associated with revision TAA using the INBONE II system. Given the growing number of TAA revision procedures and a focus on motion-preserving salvage options, we evaluated our early experience with revision TAA.

METHODS

A retrospective analysis was conducted on a group of 60 presumed noninfected patients who underwent revision TAA with the INBONE II system. Detailed information was collected on patient demographics, implant characteristics, concurrent procedures, and complications. The implant survival was estimated using Kaplan-Meier analysis.

RESULTS

The study revealed high complication rates but generally fair clinical outcomes for revision TAA using the INBONE II system. Complications were observed in 22 patients (36.7%), including persistent pain (n = 6), nerve injury/impingement (n = 5), infection (n = 3), fracture (n = 3), implant failure (n = 3), impaired wound healing (n = 2), and osteolysis (n = 3). The 3-year survivorship rate from reoperation was 92.0% (82.7%-100.0%) whereas the 3-year survivorship rate from major complications was 90.4% (80.8%-100.0%).

CONCLUSION

We report high complication rates but generally fair clinical results for revision TAA utilizing the INBONE II system.

LEVEL OF EVIDENCE

Level IV, retrospective case series study.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level IV, retrospective case series study.

Clinical Outcomes of the Lateral Trabecular Metal Total Ankle Replacement at a 5-Year Minimum Follow-up

BACKGROUND

The Trabecular Metal (Zimmer Biomet, Warsaw, IN) total ankle arthroplasty (TAA) system uses a lateral approach with a fibular osteotomy to gain access to the tibiotalar joint and a sagittally curved tibial component. This is the first TAA system to laterally approach the ankle, and few studies have explored outcomes associated with this implant. This study aimed to report the 5-year clinical and radiographic outcomes as well as the survivorship of the implant.

METHODS

Over a 3-year period, 2 fellowship-trained foot and ankle surgeons used this implant system to treat 38 end-stage arthritic ankles. Reoperation and revision data were collected from all patients (100%) as part of the local prospective database. Patients completed the Foot and Ankle Outcome Score (FAOS) questionnaire preoperatively and at each annual follow-up visit; scores for a minimum of 5 years were available for 28 (73.7%) patients. A radiographic analysis compared postoperative coronal and sagittal alignment in weightbearing radiographs at a minimum of 5 years with that at 3 months postoperatively, as well as cyst or lucency formation, which was available for 21 patients (55.3%).

RESULTS

At 5 years, there were 3 revisions (7.9%) and 9 reoperations (23.7%). Reoperations included 4 fibular hardware removal and 5 medial gutter debridement procedures. The FAOS significantly improved for all domains (P < .05). Implant positioning did not significantly change between 3 months and 5 years postoperatively.

CONCLUSION

Our 5-year results in this small series using this unique prosthesis showed good overall survivorship (92.1%) and a reoperation rate of 23.7%, along with clinically significant improvement in patient-reported outcomes.

LEVELS OF EVIDENCE

Level IV: Retrospective case series.