Clinical and Radiological Outcomes of Transfibular Total Ankle Arthroplasty

Transfibular Total Ankle Arthroplasty: Clinical, Functional, and Radiographic Outcomes and Complications at a Minimum of 5-Year Follow-up

BACKGROUND

The Trabecular Metal Total Ankle Implant differs from other newer-generation implants in the transfibular approach, multiplanar external frame for alignment, tantalum trabecular metal interfaces, curved geometry, and shallow resection depths. The primary aim of this study was to report midterm clinical and radiographic results, as well as survivorship and adverse events at a minimum of 5-year follow-up.

METHODS

A total of 83 ankles (81 patients, average age 60.6 years old, 50.6% females) with average 6.3 years' (range, 5.0-10.1) follow-up were included. Postoperative patient-reported outcome measures (PROMs) included SF-12 physical (PCS) and mental component summary (MCS) scores, Ankle Osteoarthritis Scale (AOS), pain visual analog scale (VAS). Radiographic outcomes included postoperative range of motion (ROM) and coronal/sagittal alignment. Adverse events were reported using the Canadian Orthopaedic Foot and Ankle Society Reoperation Coding System (CROCS).

RESULTS

Preoperative tibiotalar coronal deformity included 27 valgus (10 degrees, range 2-20 degrees) and 25 varus ankles (-9 degrees, range -2 to -25 degrees), corrected to neutral postoperatively. Postoperative tibiopedal ROM was 17.8 degrees dorsiflexion and 21.8 degrees plantarflexion. Adverse events occurred at average 28.7 months, most commonly gutter debridement (n = 17, 16.7%) and subsequent operative treatment unrelated to metal components (n = 10, 12.0%). There were 2 cases (2.4%) of acute deep infection treated with irrigation and debridement, polyethylene exchange, and retention of metal components without recurrence of infection. There were no cases of fibular nonunion, septic or aseptic loosening, or implant subsidence. Postoperative PROMS included SF-12 PCS: 40.4; SF-12 MCS: 56.0; VAS: 2.3; AOS Pain: 17.0; and AOS Disability: 24.9. Overall implant survival, defined by retention of the metal components, was 100% at final follow-up.

CONCLUSION

At a minimum of 5 years, patients who underwent TM TAA reported minimal ankle pain and regained neutral ankle alignment and mobility, without septic or aseptic implant loosening. Although having certain limitations, this study suggests that TM TAA is a viable option for the treatment of end-stage ankle arthritis.

Effect of Preoperative Coronal Plane Alignment on Actual Versus Predicted Alignment Using Patient Specific Instrumentation in Total Ankle Replacement

Alignment in total ankle replacement is important for success and implant survival. Recently there has been the introduction and adoption of patient specific instrumentation for implantation in total ankle replacement. Current literature does not evaluate the effect of preoperative deformity on accuracy of patient specific instrumentation. A retrospective radiographic analysis was performed on 97 consecutive patients receiving total ankle replacement with patient specific instrumentation to assess the accuracy and reproducibility of the instrumentation. Subgroup analysis evaluated the effect of preoperative deformity. All surgeries were performed by fellowship trained foot and ankle surgeons without industry ties to the implants used. Preoperative and postoperative films were compared to plans based on computerized tomography scans to assess how closely the plan would be implemented in patients. Overall postoperative coronal plane alignment was within 2° of predicted in 87.6% (85 patients). Similarly, overall postoperative sagittal plane alignment was within 2° of predicted in 88.7% (86 patients). Tibial implant size was accurately predicted in 81.4% (79 patients), and talus implant size was correct in 75.3% (73 patients). Patients with preoperative varus deformity had a higher difference between predicted and actual postoperative alignment compared to valgus deformity (1.1° compared to 0.3°, p = .02). A higher average procedure time was found in varus patients, and more adjunctive procedures were needed in patients with varus or valgus deformity, but these were not significant, p > .5. Surgeons can expect a high degree of accuracy when using patient specific instrumentation overall, but less accurate in varus deformity.

Discrepancies Between Intraoperative and Postoperative Ankle Motion Measured for Anterior-Approach Total Ankle Arthroplasty

BACKGROUND

Although intraoperative ankle motion serves as a foundational reference for anticipated motion after surgery and guides the addition of procedures to enhance ankle motion in total ankle arthroplasty (TAA), the relationship between intraoperative and postoperative ankle motion remains unclear. This study aimed to investigate the discrepancy between intraoperative and postoperative ankle range of motion (ROM) following TAAs using the anterior-approach, fixed-bearing systems.

METHODS

This study retrospectively reviewed 67 patients (67 ankles) who underwent primary TAA at a single institution. Three different types of anterior-approach, fixed-bearing TAA systems were included. Intraoperative fluoroscopy was used to document the maximal dorsiflexion and plantar flexion at the end of the case. Standardized weightbearing maximum dorsiflexion and plantar flexion sagittal radiographs were obtained pre- and postoperatively, following a previously described method. The motion between 3 different time points (preoperative, intraoperative, and postoperative [mean 11.4 months]) was compared using pairwise t tests, and their differences were quantified.

RESULTS

The mean total tibiotalar ROM was 38.1 degrees (SD 7.8) intraoperatively, and the postoperative total tibiotalar ROM was 24.2 degrees (SD 9.7) (P < .001), indicating that a mean of 65.3% (SD 26.7) of the intraoperative motion was maintained postoperatively. Intraoperative dorsiflexion (mean 11.6 [SD 4.5] degrees) showed no evidence of difference from postoperative dorsiflexion (mean 11.4 [SD 5.8] degrees, P > .99), indicating that a median of 95.6% (interquartile range: 66.2-112) of the intraoperative maximum dorsiflexion was maintained postoperatively. However, there was a significant difference between intraoperative plantarflexion (mean 26.4 [SD 6.3]) and postoperative plantarflexion (12.8 [SD 6.9] degrees, P < .001), indicating a mean 50.6% (SD 29.6) of intraoperative motion maintained in the postoperative assessment. There was an improvement of 2.5 degrees in the total tibiotalar ROM following TAA with statistical significance (P < .043).

CONCLUSION

This study revealed a significant difference between intraoperative ankle ROM and ankle ROM approximately 1 year after anterior-approach, fixed-bearing TAA, mainly due to plantarflexion motion restriction. Minimal difference in dorsiflexion suggests the importance of achieving the desired postoperative dorsiflexion motion during the surgery using the best possible adjunct procedures.

LEVEL OF EVIDENCE

Level IV, case series.

Diagnosis and Management of Infected Total Ankle Replacements

As the number of primary total ankle replacements increases for treatment of end-stage ankle arthritis, failures are also expected to rise. Periprosthetic joint infection is among the causes of failures and has been reported to be as high as 5%. Diagnosis is usually made by a combination of clinical examination findings, imaging, laboratory, and microbiological workup. Management is generally separated into limb salvage or amputation. Limb salvage can be challenging and may involve a single versus staged approach. Options include revision arthroplasty or arthrodesis procedures (ankle versus tibiotalocalcaneal), and a multidisciplinary approach is sought to eradicate infection before definitive management.

Diagnosing and Managing Infection in Total Ankle Replacement

Infections after total ankle replacement (TAR) within the first 4 weeks after implantation can be managed successfully with 1 or several debridements, irrigation, and a change of polyethylene inlay. Late infections require implant removal. Low-grade infections might be an underestimated problem so far. Although single-surgery revisions are reported in the literature, the authors' experience with 2-stage revisions using an antibiotics-loaded bone cement spacer is better. Additional antibiotics are used to support the surgical treatment. After antibiotic therapy of 12 weeks, the final treatment includes ankle or tibio-talo-calcaneal fusion and, with limitations, revision TAR.

Outcomes of Lateral Transfibular Approach for Total Ankle Replacement

Total ankle replacement through a lateral transfibular approach with trabecular metal implants was introduced in 2012 and originally was advertised as a safer approach in terms of wound healing issues. Further studies showed no significant difference comparing anterior and lateral approach for infections and would healing issues, whereas the main advantage is deformity correction, acting on coronal, sagittal, and rotational deformities and on fibular length issues. It showed a survival rate of 97.7% at 5 years follow-up.

Reliability of Cone Beam Weightbearing Computed Tomography Analysis of Total Ankle Arthroplasty Positioning and Comparison to Weightbearing X-Ray Measurements

BACKGROUND

The current reference standard for postoperative evaluation of total ankle arthroplasty (TAA) positioning, weightbearing radiography (WBXR), is subject to technical bias. Weightbearing cone beam computed tomography (WBCT) enables visualization of the foot's complex 3-dimensional (3D) structure under standing load. To date, no WBCT-based system for TAA positioning has been validated. The purpose of this study was to (1) assess TAA positioning using WBCT 3D models and (2) evaluate the agreement levels between 2 raters and thus evaluate the intermethod reliability with respect to WBXR.

METHODS

Fifty-five consecutive patients were retrospectively reviewed. Two raters independently created a 3D WBCT model using dedicated software and recorded the following measurements: α angle, tibiotalar surface angle (TSA), hindfoot angle (HFA), tibiotalar ratio (TTR), β angle, γ angle, and Φ angle. Measurements were repeated 2 months apart in similar, independent fashion and compared to WBXR. Interobserver, intraobserver, and intermethod agreements were calculated.

RESULTS

All 7 measurements showed good to excellent intraobserver and interobserver reliability (ICC 0.85-0.95). The intermethod (WBCT vs WBXR) agreement showed good agreement for the γ angle (ICC 0.79); moderate agreement levels for the α angle, TSA angle, β angle, and TTR (ICC 0.68, 0.69, 0.70, and 0.69, respectively); poor agreement for the HFA (ICC 0.25); and negative agreement for the φ angle (ICC -0.2).

CONCLUSION

Position analysis of TAA using WBCT demonstrated good to excellent interobserver and intraobserver agreement and can be reliably used. Additionally, a negative to moderate agreement between standard WBCT and standard WBXR was found.

LEVEL OF EVIDENCE

Level III, retrospective study.

Results of Transfibular Total Ankle Arthroplasty. A Series of 50 Implants

Total ankle arthroplasty has become popular in the last few years. The lateral transfibular approach is an alternative to the traditional anterior approach. The purpose of this study was to evaluate our 50 first and consecutive clinical and radiological outcomes of transfibular total ankle replacements (Trabecular Metal Total Ankle^R Zimmer Biomet, Warsaw, IN) with a follow-up of at least 3 years. This retrospective study included 50 patients. The main indication was post-traumatic osteoarthritis (n = 41). The mean age was 59 (range = 39-81). All patients were followed for at least 36 months postoperatively. Patients were assessed with the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Score and Visual analog scale (VAS) preoperatively and postoperatively. Range of motion and radiological measures were assessed as well. Postoperatively, patients demonstrated statistically significant improvement in the AOFAS score from 32 (range = 14-46) to 80 (range = 60-100) (p < .01) and VAS from 7.8 (range = 6.1-9.7) to 1.3 (range = 0-6) (p < .01). The average total range of motion increased significantly from 19.8° to 29.2° of plantarflexion and 6.8° to 13.5° of dorsiflexion. Alignment measured by alpha, beta, and gamma angles was satisfactorily achieved. No patient demonstrated any radiographic evidence of tibial or talar lucency at the final follow-up. Five patients (10%) experienced delayed wound healing. One patient (2%) developed a postoperative prosthetic infection. One patient (2%) developed fibular pseudoarthrosis and 2 patients (4%) suffered impingement. Two patients (4%) needed surgery for symptomatic fibular hardware. This study found excellent clinical and radiological results of transfibular total ankle replacement. This is a safe and effective option that allows the correction of sagittal and coronal malalignment.

Tibiotalar and Tibiotalocalcaneal Arthrodesis with Paragon28 SilverbackTM Plating System in Patients with Severe Ankle and Hindfoot Deformity

BACKGROUND AND OBJECTIVES

The treatment of end-stage ankle osteoarthritis (OA) and associated hindfoot deformities remains a major challenge for orthopedic surgeons. Numerous techniques and surgical approaches have been proposed for tibiotalar (TT) and tibiotalocalcaneal (TTC) arthrodesis, from arthroscopic to open, as well as numerous devices proposed for internal fixation (retrograde intramedullary nails, cannulated screws, and plating systems). The aim of this study was to retrospectively analyze the results, with at least 18 months of follow-up, with Silverback^TM TT/TTC Plating System Paragon28 in a group of 20 patients with severe OA and hindfoot deformities (mainly secondary post-traumatic OA).

MATERIALS AND METHODS

The demographic characteristics and past medical history of the patients were collected and analyzed to identify the cause of the pathology. The degree of OA and deformity were quantified based on foot and ankle weight-bearing radiography and CT examination. Pre- and post-operative clinical and functional scores (ROM, VAS, AOFAS, FFI, and SF-36) and radiographic parameters (anterior distal tibial angle, tibiotalar angle, coronal tibiotalar angle, and hindfoot alignment angle) were evaluated.

RESULTS

All of the patients showed clinical and radiographic fusion at an average of 14 weeks (range 12-48), with improvement in pain and functional scores, without major surgical complications and/or infections.

CONCLUSIONS

Despite the limitations of our study, the results with this new plating system showed good results in terms of bone consolidation, post-operative complications, and improvement of pain and quality of life in patients with severe OA and deformities of the ankle and hindfoot.

Fast-Track for Total Ankle Replacement: A Novel Enhanced Recovery Protocol for Select Patients

BACKGROUND

Enhanced recovery after surgery programs, also called fast-track protocols, were developed and successfully applied in the last decade for hip and knee reconstruction. Specific fast-track protocols have not yet been applied to ankle prostheses. The aim of the study was to develop and validate an enhanced recovery protocol for total ankle replacement (TAR) evaluating the clinical and radiographic results. We hypothesize that on the basis of well-defined pre- and postoperative characteristics, the current knowledge on ankle replacement, and referring to hip and knee reconstruction, it is possible to identify a "patient type" to be safely eligible to a Fast-Track Protocol with at least comparable results and without increasing the complications risk.

METHODS

We identified 8 predictive variables that might affect the outcome of TAR. Those variables were the body mass index, the state of anxiety or depression, the functional preoperative status, ankle equinus, the coronal malalignment, the surgical time, the surgical accessory procedures, and the bone quality. These characteristics were evaluated for each patient with almost validated outcome tools attributing a specific score. Based on the score obtained, the patients were divided into 2 groups: the Standard Protocol group (Control Group) and the Fast-Track Protocol group (Study Group). The main difference between treatment of the 2 groups relates to the use of postoperative plaster casts: in the Fast-Track group the cast was removed the first day after surgery and walking was allowed in sports shoes assisted with crutches, whereas in the Standard Protocol group, the cast was removed after 3 weeks. Clinical and radiographic evaluation was performed for all patients preoperatively and postoperatively every 6 months.

RESULTS

A total of 163 patients received a score between 1 and 5 and were included in the control group (Standard Protocol); 47 patients received a score of 0 and were allocated to the study group (Fast-Track Protocol). Clinically, except for the preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale score, no statistically significant differences were recorded in the multiple comparisons between the 2 groups. No significant differences were found regarding complications.

CONCLUSION

In selected patients, it is possible to apply an enhanced recovery protocol of rehabilitation, focused on immediate weightbearing and mobilization without any plaster or boot.

LEVEL OF EVIDENCE

Level II, prospective comparative 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.

Common bacteria and treatment options for the acute and chronic infection of the total ankle arthroplasty

BACKGROUND

There is little valid data available on managing infected total ankle arthroplasty (TAA).

METHODS

A single-center, retrospective evaluation from 20 patients with PJI (periprosthetic joint infection) of the ankle compared the bacteria isolated by preoperative arthrocentesis and intraoperative cultures to the pathogens of knee PJI. Long-term failure rates of irrigation and debridement (I&D) and polyethylene exchange, revision arthroplasty, and arthrodesis were analyzed.

RESULTS

The most common bacteria were Staphylococcus aureus and Coagulase-negative staphylococci. There was no significant difference when comparing the causing pathogens of PJI of the ankle with the knee. After a follow-up of 50,4 months, the long-term failure rate after I&D and polyethylene exchange was 40%, and of revision was 9%.

CONCLUSIONS

We concluded that the pathogenesis of PJI of the ankle and knee seems to be comparable. Regarding treatment options, we found that standardized techniques for PJIs of the knee have their limitations regarding infected TAA.

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.

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.

Transfibular total ankle arthroplasty : a new reliable procedure at five-year follow-up

AIMS

This study reports updates the previously published two-year clinical, functional, and radiological results of a group of patients who underwent transfibular total ankle arthroplasty (TAA), with follow-up extended to a minimum of five years.

METHODS

We prospectively evaluated 89 patients who underwent transfibular TAA for end-stage osteoarthritis. Patients' clinical and radiological examinations were collected pre- and postoperatively at six months and then annually for up to five years of follow-up. Three patients were lost at the final follow-up with a total of 86 patients at the final follow-up.

RESULTS

A total of 86 patients were evaluated at a mean follow-up of 65.4 months (60 to 90). At five-year follow-up, statistically significant improvements (p < 0.001) were found in the mean American Orthopaedic Foot & Ankle Society Ankle Hindfoot Score (from 33.8 (SD 14.3) to 86.1 (SD 8.8)), visual analogue scale for pain (from 8.5 (SD 1.7) to 1.5 (SD 1.2)), Short Form-12 Physical and Mental Component Scores (from 29.9 (SD 6.7) and 43.3 (SD 8.6) to 47.3 (SD 7.5) and 52.2 (SD 8.0), respectively), and mean ankle dorsiflexion and plantarflexion (from 6.2° (SD 5.5°) and 9.6° (SD 5.8°) to 23.9° (SD 7.7°) and 16.9° (SD 7.2°), respectively). Radiologically, the implants maintained neutral alignment without subsidence. Tibial or talar radiolucency was found in eight patients, but none of these patients was symptomatic. At five-year follow up, 97.7% of implants (95% confidence interval 91.2 to 99.4) were free from revision or removal with 84 implants at risk. We recorded two cases (2.3%) of failure for septic loosening.

CONCLUSION

Transfibular TAA is safe and effective with a high survival rate at mid-term follow-up and satisfactory clinical and radiological results. Further studies are required to determine the long-term performance of these implants. Cite this article: Bone Joint J 2022;104-B(4):472-478.

Reconstruction of a missing or insufficient distal fibula in the setting of a total ankle replacement: The Milanese technique

BACKGROUND

The presence of an intact distal fibula is reported as a prerequisite when considering total ankle replacement and its lack is usually considered a contraindication. The purpose of the study was to describe the results of a surgical technique to reconstruct the distal fibula (Milanese fibular reconstruction technique) in the setting of a total ankle replacement and insufficient fibula.

METHODS

Retrospective analysis of 15 patients (15 ankles) who underwent rotational fibular reconstruction technique with minimum follow-up of 24 months. Patients were evaluated preoperatively and at the last follow-up with AOFAS Ankle and Hindfoot score, VAS pain scale, SF-12 and range of motion. Standard weightbearing radiographs were used for radiographic assessment.

RESULTS

The average of all clinical scores significantly improved (P<.001). The average radiographic parameters showed a neutral alignment. No cases of reabsorption of the new lateral malleolus were observed even in cases with complications that accounted for 2 superficial wound infection and 2 deep infections.

CONCLUSIONS

The Milanese fibular reconstruction technique can successfully reestablish a lateral strut and in the setting of an ankle prosthesis in patients with an insufficient fibula.

Lateral Instability in Total Ankle Arthroplasty: A Comparison Between the Brostrom-Gould and Anatomic Lateral Ankle Stabilization (ATLAS)

BACKGROUND

Lateral ankle instability is not uncommon after osseous cuts and soft tissue releases are performed during Total Ankle Arthroplasty (TAA), particularly with varus malalignment. The purpose of the present study was to compare the outcomes of ankles that underwent TAA with concurrent Brostrom-Gould (BG) or Anatomic Lateral Ankle Stabilization (ATLAS) at a minimum of 1-year follow-up.

METHODS

Thirty-eight TAAs underwent BG (21 INFINITY, 4 CADENCE) or ATLAS (13 INBONE-2) between August 2015 and February 2019 at a single institution and were at least 1 year postoperative (mean 18.3 months, range: 12-40). Baseline patient demographics, characteristics, and operative factors were assessed via medical record and chart reviews. Radiographs parameters were measured preoperatively, at 6 weeks postoperative, and during the latest follow-up. Revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et al, respectively. Univariate and multivariate analyses were performed.

RESULTS

Survivorship for TAA with concurrent BG/ATLAS was 97%. Overall, TAA with concurrent BG had higher incidences of early TAA revision (4%), recurrent instability (4%), reoperation (16%), and complications (29%) compared to ATLAS. Postoperative coronal and sagittal tibiotalar alignment changes were significant for both groups (P < .001, P = .014); however, the differences were greater for ATLAS (P = .045, P < .001).

CONCLUSION

The present study is the first to compare outcomes between techniques for addressing ankle instability in the TAA population. At short-term follow-up, anatomic reconstruction produced better outcomes than the traditional BG procedure. Additional comparative studies between techniques to address instability in the TAA population are warranted.

LEVEL OF EVIDENCE

Level III: Retrospective cohort study.

Establishing a New Patient-Specific Implantation Technique for Total Ankle Replacement: An In Vitro Study

BACKGROUND

Revision rates after total ankle replacements (TARs) are higher compared with other total joint replacements. The present study aimed to establish a new patient-specific implantation (PSI) technique for TAR.

MATERIAL AND METHODS

A total of 10 complete Caucasian cadaver legs had whole leg computed tomography scans. The individual geometrical ankle joint axis was determined, and based on this axis, the position of the prosthesis was planned. We assessed prosthesis placement, guiding block position, and preoperative and postoperative ankle rotational axes.

RESULTS

The guiding block position interobserver reliability was 0.37 mm 0.45 (mean ± SD) for the tibial guiding block. The value for the first talar guiding block was 1.72 ± 1.3 mm and for the second talar guiding block, 0.61 ± 0.39 mm. The tibial slope as well as the frontal angles of the anatomical tibial axis compared to the tibial and talar articular surfaces showed no statistically relevant differences with numbers available. The deviation of the assessed preoperative joint axis to the postoperative joint axis was 14.6° ± 7.8.

CONCLUSION

The present study describes the results of an establishing process of a new PSI technique for TAR. The reliability of guiding block positioning and, thereby, prosthesis placement is sufficient.

LEVEL OF EVIDENCE

Biomechanical study.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level IV, case series.

Early Experience With the CADENCE Total Ankle Prosthesis

A number of 2-component, fourth-generation total ankle arthroplasty prostheses have been introduced to the market. The purpose of the present study was to present early experience with the CADENCE total ankle prosthesis. All patients who underwent primary total ankle arthroplasty using the prosthesis between August 2016 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 32 ankles with a mean follow-up of 24 (range, 12-33) months met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 weeks postoperative, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook et el, respectively. Coronal and sagittal tibiotalar alignment significantly improved after surgery (p < .001, p < .005), and was maintained during the latest follow-up (p = .44, p = .30). Two (6.3%) ankles underwent early revision for aseptic loosening; while 6 (18.8%) underwent a nonrevisional reoperation. Nine (28.1%) ankles presented a total of 13 (4 high grade, 2 intermediate, and 7 low) complications according to the Glazebrook classification. The most common was intraoperative periprosthetic medial malleolar fracture (5 ankles, 15.6%), a low-grade complication. The present study is the first to report early outcomes and experience with the CADENCE total ankle. Overall, survivorship was 94% at short-term follow-up of 2 years. As with all arthroplasty devices, surgeons new to the prosthesis should be cognizant of the potential learning curve. Intraoperative medial malleolar fracture was found to be the most common complication.

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

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

Clinical Radiographical Outcomes and Complications after a Brand-New Total Ankle Replacement Design through an Anterior Approach: A Retrospective at a Short-Term Follow Up

Recently, the progress in techniques and in projecting new prosthetic designs has allowed increasing indications for total ankle replacement (TAR) as treatment for ankle osteoarthritis. This retrospective work comprehended 39 subjects aged between 47 and 79 years old. The patients, observed for at least 12 months (mean follow up of 18.2 ± 4.1 months), have been evaluated according to clinical and radiological parameters, both pre- and post-operatively. The AOFAS and VAS score significantly improved, respectively, from 46.2 ± 4.8 to 93.9 ± 4.1 and from 7.1 ± 1.1 to 0.7 ± 0.5 (p value < 0.05). At the final evaluation, the mean plantarflexion passed from 12.2° ± 2.3° to 18.1° ± 2.4° (p value < 0.05) and dorsiflexion from a pre-operative mean value of 8.7° ± 4.1° to 21.7° ± 5.4° post-operatively (p value < 0.05). This study found that this new total ankle replacement design is a safe and effective procedure for patients effected by end-stage ankle osteoarthritis. Improvements have been demonstrated in terms of range of motion, radiographic parameters and patient-reported outcomes. However, further studies are needed to assess the long-term performance of these prostheses.

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.

Learning curve assessment for total ankle replacement using the transfibular approach

BACKGROUND

Total ankle arthroplasty is an increasingly effective option for the treatment of end-stage arthritis. One recent innovation utilizes a transfibular, lateral approach. Like any new system, there is likely a learning curve associated with its use. We analyzed a series of patients who received a total ankle arthroplasty via a transfibular approach to state if it is possible to identify and to evaluate effects of a learning curve in the use of this novel total ankle replacement system.

METHODS

76 consecutive patients meeting inclusion and exclusion criteria were retrospectively analyzed. All patients had a minimum of 24 months of follow-up. Intraoperative parameters, preoperative and postoperative subjective outcome scores, radiographic parameters, and complications were recorded and evaluated.

RESULTS

There were significant learning curve effects on various surgical and postoperative parameters. Surgical time decreased with the curve stabilizing after the 16th patient. With regard to patient outcomes, a learning curve was identified for the VAS, AOFAS, and SF-12 MCS scores. The number of patients required to stabilize these curves were 21, 13, and 16, respectively. Alignment as measured by alpha and gamma angles also improved with experience, with the curves stabilizing at 18 and 15 patients, respectively. There was a larger number cases required for complication rates, with the curve stabilizing after the 39th patient. No significant learning curve was found for ankle ROM, SF-12 PCS, beta angle, tibio-talar ratio (TTR), or tibio-talar surface angle (TTS).

CONCLUSIONS

This study demonstrates a significant learning curve with respect to operative time, patient outcomes, and radiographic parameters. Extrapolating this information, we urge surgeons to adequately familiarize themselves with any new implant through a training program in a high-volume center.

LEVEL OF EVIDENCE

IV, case series.

Histological Analysis of a Retrieved Porous Tantalum Total Ankle Replacement: A Case Report

CASE

We present a case report documenting the retrieval and histological analysis of a porous tantalum (P-Ta) total ankle replacement (TAR) from a 50-year-old woman after a below-knee transtibial amputation. This rare opportunity to examine an intact TAR may help to better understand the implant-bone relationship because it would be in situ.

CONCLUSION

In this case study, we demonstrate bone ingrowth to the first layer of the P-Ta and organized trabecular orientation, suggesting that equal bone load was achieved on the base and the rails in both components using a transfibular surgical approach.

Clinical-radiological outcomes and complications after total ankle replacement through a lateral transfibular approach: a retrospective evaluation at a mid-term follow-up

PURPOSE

Degenerative ankle arthropathy is a debilitating and increasingly widespread condition with worsening of quality of life. In last years, total ankle replacement has increased indications, thanks to advances in surgical technique, materials and design that provided new solutions for surgeons. The purpose of this study is to evaluate the effectiveness of total ankle replacement (TAR), implanted using a trans-fibular lateral approach in patients with high-grade degenerative arthropathy, in terms of clinical, functional and radiological outcomes and possible complications.

METHODS

This retrospective study included 73 patients, aged between 47 and 79 years (mean age 61.7 ± 14.2 years), who underwent trans-fibular total ankle arthroplasty. All patients were followed up for at least two years post-operatively with mean follow-up 31.2 ± 8.1 months and have been evaluated clinically and radiographically both pre-operatively and post-operatively.

RESULTS

Patients demonstrated a significant improvement in average AOFAS score, SF-36 score and VAS scale. Average plantarflexion improved from 9.9° ± 4.2 to 18.4° ± 6.3 and dorsiflexion from pre-operative mean value of 6.8° ± 5.8 to 17.2° ± 3.1 post-operative. Complications recorded in our series were 16 (21.9%), specifically 2 major complications and 14 minor complications.

CONCLUSIONS

This study found that trans-fibular total ankle replacement is a safe and effective option for patients with ankle osteoarthritis, resulting in improvement of patient-reported outcomes, range of motion, and radiographic parameters. However, further studies are required to determine long-term performance of these implants.

Reoperation Profile of Lateral vs Anterior Approach Ankle Arthroplasty

BACKGROUND

The operative procedure for a total ankle replacement (TAR) is intimately associated with the prosthetic design. The anterior and lateral approaches both have pros and cons regarding their respective soft tissue complications, osteotomy requirements, orientation of the bone cut, and gutter visualization. Although both have been studied independently, few reports have compared both in the same setting. The purpose of this retrospective study was to investigate the difference in reoperation rate after lateral or anterior approach ankle arthroplasty. We hypothesized that the anterior approach had a higher rate of wound complications.

METHODS

We evaluated data from a single center collected between 2014 and 2017, comprising a total of 115 total ankle replacements performed by 1 of 4 fellowship-trained foot and ankle surgeons. Reoperations were recorded as an operative report with classification by Canadian Orthopaedic Foot and Ankle Society (COFAS) Reoperations Coding System (CROCS). The index approach used was determined by the surgeon's practice preference. Patients were included when they had a primary TAR in the time frame noted and had a complete data set up to at least 2 years after surgery. The cohort comprised 67 anterior and 48 lateral operations with balanced demographics for age (95% CI: 63-67 years) and gender (47% F). The lateral group had more complex cases with higher COFAS type arthritis (more periarticular arthritis and surrounding deformity).

RESULTS

Comparing the 2 groups, a total of 40 reoperations (7 anterior [A], 33 lateral [L]) occurred in 27 patients (5 A, 22 L). One patient had 4 related reoperations. The only revision was in the anterior group. The only soft tissue reconstruction was a split-thickness skin graft in the lateral group. Nine reoperations were irrigation debridement related to an infection or wound complication (3 A, 6 L). The majority (19/33) of reoperations in the lateral group were gutter debridement (8) or lateral hardware removal (11). Operative time was statistically different at 145 minutes (95% CI: 127-164 minutes) in anterior TAR and 178 minutes (95% CI: 154-202 minutes) for lateral TAR (P = .0058). The odds ratio of having any reoperation with a lateral approach TAR was 6.19 compared to the anterior group.

CONCLUSION

The results at the 2-year time point demonstrated that there were more reoperations after a lateral approach TAR than an anterior TAR, recognizing the significant case complexity imbalance between the groups and a corresponding relative increase in resource utilization of lateral TAR patients. The 2 implant designs were associated with different reoperation rates, favoring the anterior group. Change in the lateral fixation may have reduced the risk of repeat surgery.

LEVEL OF EVIDENCE

Level III, retrospective comparative series.

Results of Trabecular-Metal Total Ankle Arthroplasties With Transfibular Approach

BACKGROUND

Total ankle arthroplasty is an alternative for arthrodesis. The objective of this study was to investigate the safety of trabecular-metal ankle prosthetic system with transfibular approach and external frame and its association with changes in clinical and functional scores.

METHODS

Between May 2013 and June 2017, a total of 104 consecutive patients underwent primary total ankle arthroplasty with a trabecular metal implant. The prospective clinical and radiographic data were collected. The mean follow-up time was 43.6 (14.6) months.

RESULTS

Of 104 patients, 88 (89%) reported improved functioning and 65 (66%) were very satisfied with the surgery. Of the patients, 51 (50%) did not report any pain at the end of follow-up at all. The average Kofoed score was 37.6 (SD 17.4) points at baseline and 74.8 (SD 20.6) points at the end of follow-up. There were 37 additional procedures, and the complication rate was nearly 20%.

CONCLUSION

Trabecular-metal total ankle prosthesis showed promising clinical results concerning pain and function. At 5-year follow-up, osteolysis and component loosening were rare.

LEVEL OF EVIDENCE

Level IV, case series.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

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

Total Ankle Replacement Options

Total ankle arthroplasty has been in development for more than 40 years. Although early designs were experimental with high failure rates, current implants are significantly improved, showing promising functional results and clinical outcomes. Total ankle replacement designs are split into mobile-bearing and fixed-bearing designs. When deciding whether to perform ankle arthroplasty, many factors need to be considered to determine if the patient is suitable and which implant is the best fit for patient and surgeon. Many prostheses are available in the United States today and the purpose of this article is to outline options for foot and ankle surgeons.

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.

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.