Total ankle replacement leads to high revision rates in post-traumatic end-stage arthrosis

Influence of Tibial Component Design Features and Interference Fit on Implant-Bone Micromotion in Total Ankle Replacement: A Finite Element Study

BACKGROUND

Implant survivorship in uncemented total ankle replacement (TAR) is dependent on achieving initial stability. This is because early micromotion between the implant and bone can disrupt the process of osseointegration, leading to poor long-term outcomes. Tibial implant fixation features are designed to resist micromotion, aided by bony sidewall retention and interference fit. The goal of this study was to investigate design-specific factors influencing implant-bone micromotion in TAR tibial components with interference fit.

METHODS

Three implant designs with fixation features representative of current TAR tibial components (ARC, SPIKES, KEEL) were virtually inserted into models of the distal tibias of 2 patients with end-stage ankle arthritis. Tibia models were generated from deidentified patient computed tomography scans, with material properties for modeling bone behavior and compaction during press-fit. Finite element analysis (FEA) was used to simulate 2 fixation configurations: (1) no sidewalls or interference fit, and (2) sidewalls with interference fit. Load profiles representing the stance phase of gait were applied to the models, and implant-bone micromotions were computed from FEA output.

RESULTS

Sidewalls and interference fit substantially influenced implant-bone micromotions across all designs studied. When sidewalls and interference fit were modeled, average micromotions were less than 11 µm, consistent across the stance phase of gait. Without sidewalls or interference fit, micromotions were largest near either heel strike or toe-off. In the absence of sidewalls and interference fit, the amount of micromotion generally aligned inversely with the size of implant fixation features; the ARC design had the largest micromotion (~540 µm average), whereas the KEEL design had the smallest micromotion (~15 µm).

CONCLUSION

This study presents new insights into the effect of TAR fixation features on implant-bone micromotion. With sidewalls and interference fit, micromotion is predicted to be minimal for implants, whereas with no sidewalls and no interference fit, micromotion depended primarily on the implant design.

CLINICAL RELEVANCE

This study presents new insights into the effect of TAR primary fixation features on implant-bone micromotion. Although design features heavily influenced implant stability in the model, their influence was greatly diminished when interference fit was introduced. The results of this study show the relative importance of design features and interference fit in the predicted initial stability of uncemented TAR, potentially a key factor in implant survivorship.

Corrective Intra-articular Osteotomy for Malreductions of Tibial Pilon Fractures in Patients Less Than 55 Years Old

BACKGROUND

Tibial pilon malreductions are challenging to correctively reconstruct, and the relevant literature is limited. This study aims to assess whether corrective intra-articular osteotomy is worthwhile to treat relatively younger (<55-year-old) patients with intra-articular malreductions of pilon fractures.

METHODS

This is a retrospective observational study with a minimum follow-up of 2 years. From 2013 to 2021, 21 patients (mean age: 39.2 ± 11.2 years) with intra-articular pilon malreductions ≥6 weeks treated with intra-articular osteotomies were analyzed. The median interval time until intra-articular osteotomy was 76 (interquartile range [IQR], 49-149) days. Plain radiographs and computed tomography were used for radiographic assessments. Clinical outcomes were evaluated with visual analog scale (VAS), the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, the 36-Item Short-Form Health Survey (SF-36) score, and ankle range of motion (ROM).

RESULTS

The median follow-up duration was 34.6 (IQR, 26.1-74.3) months. The median articular displacement was reduced from 12.7 mm preoperatively to 2.7 mm postoperatively (P < .05). According to the Kellgren-Lawrence grading, 16 patients were assigned to stage II, 4 to stage III, and 1 to stage IV. In the 10 patients with available preoperative assessments, substantial improvement was found in the VAS score, from 5.90 to 2.0 at the final follow-up (P < .05). Similarly, the AOFAS ankle-hindfoot score and SF-36 scores improved (P < .05). Ankle ROM did not change a clinically meaningful amount. Progressive degenerative changes were noted in 2 of 10 patients who had adequate preoperative imaging. Four patients had VAS scores ≥4 including 1 patient who is scheduled for an arthrodesis.

CONCLUSION

In this small series, we found that the corrective osteotomies generally provided reasonable improvement at 3 years in patients <55 years old with intra-articular malreduction of pilon fractures. Prospective cohort studies are needed to determine if it is worthwhile in long-term outcome.

Short-Term Outcomes After Bipolar Osteochondral Allograft Transplantation (OCAT) in the Ankle

Treatment options for symptomatic cartilage loss in the ankle are not consistently effective. This study documents initial outcomes for patients undergoing bipolar OCAT in the ankle after advances in tissue preservation, transplantation techniques, and patient management strategies were implemented. Patients were prospectively enrolled into a registry designed to follow outcomes after OCAT in the ankle. Fourteen patients were included for analyses (12 primary OCAT, 2 revision OCAT). Four patients underwent Bipolar OCAT (tibia, talus) and 10 Bipolar+ OCAT (tibia, talus, fibula). Short-term (median follow-up 43, range 13-73 months) success was documented for 13 patients. Radiographic assessments indicated OCA integration and maintenance of joint space in 12 patients. Statistically significant (p < .030) and clinically meaningful improvements in AAOS and VAS pain scores were noted at 3 months, 6 months, 1 year, and 2 years following OCA transplantation when compared to preoperative measures. For patients that were nonadherent to postoperative restriction and rehabilitation protocols, all 1-year postoperative PROs were significantly lower (p < .050) than for patients who were adherent. The successful outcomes documented in 13 of 14 patients in conjunction with significant and clinically meaningful improvements in patient-reported measures of pain and function support OCA transplantation as an appropriate treatment option in indicated patients. These improvements in outcomes were associated with advances in OCA preservation, preimplantation treatment, transplantation techniques, and patient management strategies, suggesting this shift in practice be considered for OCA transplantation in the ankle.

Influence of sidewall retention and interference fit in total ankle replacement on implant-bone micromotion: A finite element study

The success of uncemented total ankle replacement (TAR) is linked to initial stability because bony ingrowth depends upon limited early micromotion. Tibial implant design fixation features resist micromotion aided by bony sidewall retention and interference fit. Our goal was to investigate factors influencing implant-bone micromotion in TAR. Two TAR tibial components were virtually inserted into CT-derived computer models of two distal tibias from patients with end-stage ankle arthritis. Density-based inhomogeneous material assignment was used to model bone compaction during press-fit. Finite element analysis (FEA) was used to simulate three fixation cases: (1) no sidewalls + line-to-line fit, (2) sidewalls + line-to-line fit, and (3) sidewalls + 50, 100, or 200 µm interference fit. Kinetic profiles from the stance phase of gait were simulated and micromotions computed from FEA output. Without sidewalls or interference fit, micromotions were largest in early and late stance, with largest micromotions (averaging ~150-250 µm) observed near heel strike. Micromotions decreased 39%-62% when sidewalls were retained. When interference fit was also modeled, micromotions decreased another 37%-61% to ~10 µm. Micromotion differences between patients persisted with sidewall retention but largely disappeared with interference fit. This study presents new insights into the effects of TAR fixation features on implant-bone micromotion. Stability appeared to be influenced by surrounding bone quality, but this influence was greatly diminished when interference fit was introduced. More complete understanding of TAR implant features and performance is needed, but our results show the importance of bone quality and interference fit in the stability of uncemented TAR.

Osteoperiosteal Iliac Autograft Transplantation for Unreconstructable Tibial Plafond After Malunions of Pilon Fractures in Young Patients

BACKGROUND

Malunion of tibial pilon fracture, especially with a large cartilage loss of the tibial plafond, is a tough clinical conundrum. This study describes a joint-preserving technique that mainly involves corrective intraarticular osteotomy and osteoperiosteal iliac autograft transplantation for treating these generally considered unreconstructable tibial plafond.

METHODS

Sixteen patients with an average age of 33.6 years who were treated with this joint-preserving method between 2013 and 2020 were retrospectively analyzed. Ankle distraction was applied in all patients. Additional osteochondral autograft transplantation for talus was performed in 4 patients and supramalleolar osteotomy in 2 patients. The visual analog scale (VAS) score, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, the 36-Item Short Form Health Survey (SF-36) score, and the ankle range of motion (ROM) were used for outcome analysis. Radiographic assessment was conducted, and the complications were recorded.

RESULTS

At a mean follow-up of 41.1 months, the mean VAS, AOFAS, and SF-36 scores improved from 6.3, 47.6, and 38.0 to 1.7, 84.4, and 70.8, respectively (P < .001 for each). The ankle ROM improved from 27.5 to 32.2 degrees (P = .023). The mean area of ilium blocks was 3.5 cm2, and the mean external fixation time was 94.1 days. Radiographs showed that good osteointegration was found in all patients and no significant progression of osteoarthritis in 15 patients. The major complications included poor incision healing in 2 patients and severe ankle stiffness in 2 patients, with one of them developing considerable varus-type osteoarthritis but reporting no pain. No deep infection, nonunion, or malunion occurred, and no secondary arthrodesis was performed during the final follow-up.

CONCLUSION

Osteoperiosteal iliac autograft transplantation might be an alternative surgical option for reconstructing unreconstructable malunited pilon fractures with a large cartilage loss of the tibial plafond in young patients.

LEVEL OF EVIDENCE

Level IV, case series.

Outcomes of Total Ankle Arthroplasty in Postfracture Ankle Arthritis

BACKGROUND

Ankle arthritis that develops after fracture accounts for a significant portion of ankle arthritis necessitating total ankle arthroplasty (TAA). It remains unknown whether TAA in postfracture patients produces equivalent outcomes to those without fracture history. The purpose of this study was to evaluate the medium-term outcomes of TAA in postfracture ankle arthritis compared to those without fracture history.

METHODS

This study reviewed 178 ankles from 171 consecutive patients who underwent TAA in our institution between 2007 and 2017 and completed a minimum 5-year follow-up. Four different TAA systems were utilized by 6 surgeons. Based on fracture history, patients were divided into 2 groups: the postfracture group (n = 63; median age 65.7 years; median follow-up 5.9 years) and the nonfracture group (n = 115; median age 64.4 years; median follow-up 6.2 years). Types and rates of complications including revision and reoperation were compared. Minimum 5-year Foot and Ankle Outcome Score (FAOS) and postoperative improvement were investigated. A subgroup analysis was performed to determine whether outcomes differ between intraarticular fracture patients (n = 43) and extraarticular fracture patients (n = 20).

RESULTS

Both groups exhibited comparable postoperative improvement and final FAOS scores. The postfracture group had a significantly higher reoperation rate than the nonfracture group (20 of 63, 31.7%, vs 17 of 115, 14.8%; P = .011), with gutter impingement being the most common cause. There were 3 revisions in each group. In the subgroup analysis, we found no evidence of statistical difference between the intraarticular fracture group and the extraarticular fracture group in terms of FAOS scores, revision, and reoperation rates.

CONCLUSION

In this single-center, retrospective comparative study, we found total ankle arthroplasty in patients with a history of fractures around the ankle joint had no evidence of statistical difference in patient-reported outcomes and implant survivorship but led to a higher rate of nonrevision reoperation following surgery. In the much smaller subset of patients with previous fracture, we did not find that those with a history of intraarticular fracture had inferior outcomes after TAA when compared to those with a history of extraarticular fracture.

LEVEL OF EVIDENCE

Level III, case-control study.

Protocol for a randomised feasibility trial comparing a combined program of education and exercise versus general advice for ankle osteoarthritis

BACKGROUND

Ankle osteoarthritis (OA) is a serious problem with high associated pain and disability. While education and exercise are recommended for the initial management of OA, this has not been investigated in ankle OA. The primary aim of this study is to establish the feasibility of running a full-scale randomised controlled trial (RCT) investigating a combined education and exercise program compared to a general advice program for people with ankle OA. The secondary aims are to collect preliminary data which will inform sample size calculations, and understand the perspectives of people with ankle OA on their participation in the trial.

METHODS

Thirty individuals aged 35 years or older with symptomatic radiographic ankle OA will be recruited from the community and randomised to receive either a combined education and exercise program or a general advice program, both of which will be delivered by a physiotherapist in a group setting. Primary outcomes of feasibility include responses to study advertisements, number of eligible participants, recruitment rate, adherence with the intervention, fidelity of the intervention, adverse events, drop-out rate, and credibility and expectancy of the intervention. Secondary participant-reported outcomes will include global rating of change, patient acceptable symptom state, severity of ankle pain and stiffness, self-reported function, quality of life, satisfaction with treatment, and use of co-interventions. Follow up will be at 8 weeks and 3 months. Physical measures of 40 m walking speed, timed stairs descent, heel raise endurance and ankle dorsiflexion range of motion will be collected at baseline and 8 weeks. Primary feasibility outcomes will be reported descriptively, and estimates of the variability of secondary participant-reported and physical outcomes will be calculated. Semi-structured interviews will be conducted with participants to understand perspectives about the intervention and participation in the trial, with data analyzed thematically.

DISCUSSION

Study findings will establish the feasibility of running a full-scale RCT to investigate a combined education and exercise program compared to a general advice program for people with ankle OA. This study is a necessary first step to advance the international research agenda of evaluating the efficacy of exercise in the management of ankle OA.

TRIAL REGISTRATION

ACTRN12623000017628. Registered 10 January 2023, https://www.anzctr.org.au/ACTRN12623000017628.aspx .

Preservation of the Subtalar Joint Determines Outcomes in a 10-Year Evaluation of Ankle Arthrodesis

Posttraumatic osteoarthritis may lead to surgical fusion of the ankle joint if non-surgical therapy fails. The indication for a fusion of the joint is based on the pain and disability of the patient, radiographic imaging, and surgeon experience, with no strict guidelines. We aimed to compare outcomes after tibiotalocalcaneal arthrodesis (TTCA) and tibiotalar arthrodesis (TTA) to highlight the functional importance of the subtalar joint. In total, 432 patients with ankle arthrodesis were retrospectively enrolled. Group A (n = 216) underwent TTCA; group B (n = 216) underwent TTA. Demographics, Olerud & Molander Ankle Score (OMAS), Foot Function Index (FFI-D), and Short Form-12 Questionnaire (SF-12) were recorded at a mean follow-up of 6.2 years. The mean OMAS was 50.7; the mean FFI-D was 68.9; the mean SF-12 physical component summary was 39.1. These scores differed significantly between the groups (p < 0.001). The overall revision rate was 18%, primarily for revision of non-union and infection (p < 0.001). Approximately 16% of group A and 26% of group B were able to return to previous work (p < 0.001). Based on significantly worse clinical scores of TTCA compared to TTA and the prolonged downtime and permanent incapacity, the indication for a generous subtalar joint arthrodesis with planned ankle arthrodesis should always be critically examined.

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.

Intermediate to long-term clinical outcomes and survival analysis of the Salto Mobile Bearing total ankle prothesis

INTRODUCTION

Osteoarthritis of the ankle is a major burden to affected patients. While tibio-talar arthrodesis has been the gold-standard regarding the treatment of osteoarthritis of the ankle joint for many years, at present total ankle arthroplasty (TAA) provides appealing clinical outcomes and is continually gaining popularity. The aim of this study was to evaluate the intermediate- to long-term clinical outcome including the survival rate of Salto Mobile Bearing TAA (Tonier SA, Saint Ismier, France).

MATERIAL AND METHODS

In this retrospective study intermediate- to long-term outcomes measures [Ankle Range of Motion (ROM), American Orthopaedic Foot and Ankle Score (AOFAS score) and survival rate] of 171 consecutive TAA were analysed and compared before and after surgery. Revision was defined as secondary surgery with prothesis component removal, while reoperation was defined as a non-revisional secondary surgery involving the ankle.

RESULTS

At a mean follow-up (FU) period of 7.2 ± 2.7 years (range 2.0 to 14.1 years) there was a significant improvement in ankle ROM (total ROM improved from 25.0° ± 15.0° to 28.7° ± 11.3°, p = 0.015; plantarflexion improved from 18.4° ± 11.7° to 20.6° ± 8.2°, p = 0.044; dorsiflexion improved from 6.6° ± 5.7° to 8.1° ± 4.9°, p = 0.011). AOFAS score increased significantly by 41 ± 15 points after surgery (43.3 ± 11.1 before and 84.3 ± 12.0 after surgery, p < 0.001). Overall survival rate within the FU was 81.3% (95% CI 75.3% to 87.3%) with any secondary surgery, 89.9% (95% CI 84.1% to 93.6%) with revision and 93.6% (95% CI 89.8% to 97.3%) with reoperation as endpoint.

CONCLUSION

This study endorses the previously reported appealing intermediate- to long-term outcomes of the Salto Mobile Bearing TAA. There was a significant increase in ROM and AOFAS score as well as decent implant survival at final FU.

Soft-Tissue Reconstruction of Complicated Total Ankle Arthroplasty

BACKGROUND

Total ankle arthroplasty (TAA) is a popular modality to treat end-stage arthritis or internal ankle derangement. Unfortunately, failure rates remain undesirably high, with severe complications, including prosthesis failure, ankle fusion, and amputation. The importance of a stable soft-tissue envelope for coverage of implant compromise has been previously described, but the predictive factors for successful salvage of complicated TAA remain poorly understood.

METHODS

A retrospective review was conducted of patients requiring soft-tissue reconstruction following TAA wound complications. Patient demographics, history, microbiological data, reconstructive approach, and outcomes data were collected. Statistical analysis was used to abstract factors associated with unsuccessful prosthetic salvage.

RESULTS

In all, 13 patients met inclusion criteria: 8 (61.5%) achieved prosthetic salvage, and 5 (38.5%) failed. The majority (90.9%) of patients presented with infected joints. Reconstructive techniques included skin grafts, dermal substitutes, locoregional flaps, and free tissue transfer. Successful prosthetic salvage was associated with shorter time intervals between wound diagnosis and index reconstructive surgical intervention (median: 20 days for salvage vs 804 days for failure; P = .014). Additionally, salvage was associated with reduced time from the index orthopaedic/podiatric surgical intervention to the index reconstructive surgery procedure (12 vs 727 days; P = .027).

CONCLUSION

The prognosis of complicated TAA requiring soft-tissue reconstruction remains poor, especially in patients who present with infected joints. Several reconstructive techniques, ranging from simple skin grafts to complex free tissue transfers, can be used successfully. Early intervention to achieve soft-tissue coverage is crucial in maximizing salvage rates in the setting of complicated and infected TAA.

LEVEL OF EVIDENCE

Level IV.

Protocol for the development of a core domain set for individuals with ankle osteoarthritis

Background

Ankle osteoarthritis (OA) is a debilitating health condition that is increasing in prevalence. Currently, there are no evidence-based guidelines for managing ankle OA. One of the current challenges to establishing guidelines is the lack of a widely agreed-upon set of outcome measures that are consistently used in ankle OA research. Without a set of agreed-upon outcome measures, it is difficult to synthesise clinical trial outcomes through meta-analysis—an essential element of evidence-informed practice. In order to develop an appropriate set of outcome measures for ankle OA, it is important first to develop a core domain set. In this protocol, we describe the methodological approach that we will use to develop such a core domain set for ankle OA.

Methods

We established an international steering committee to guide the development of a core domain set for ankle OA. The core domain set development will follow a multi-staged approach consisting of three phases, involving participation by patients and clinicians/healthcare professionals. In phase 1, a list of candidate domains will be gleaned from (a) a scoping review of outcome measures used in ankle OA research, (b) qualitative interviews with individuals with ankle OA, and (c) qualitative interviews with healthcare professionals with expertise in ankle OA. In phase 2, the steering committee will review and generate a list of candidate domains from those gleaned in phase 1. In phase 3, this list of candidate domains will be considered in a Delphi process to reach a consensus on a core domain set. We anticipated this will involve 3 rounds of surveys.

Conclusion

This protocol describes the methods that will be used to develop a core domain set of health-related aspects for ankle OA. Importantly, it will include both healthcare professional and patient involvement. This is a prerequisite step to developing a core outcome set for ankle OA that should be reported in all clinical trials for ankle OA. The findings will be widely disseminated across peer-refereed publication(s) and national and international conferences, as well as via relevant professional societies, patient support group organisations, and social media platforms.

Project registration

This project is registered with the Core Outcome Measures in Effectiveness Trials (COMET) database on 17 March 2021. https://www.comet-initiative.org/Studies/Details/1837.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06692-0.

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.

A Novel Method for Preoperative Positioning of Total Ankle Replacement Using 3D Digital Model

OBJECTIVE

To establish a digital model of the ankle joint through 3D imaging technology and explore the preoperative placement of ankle replacement prostheses.

METHODS

Computed tomography images of intact ankle joints from 54 cases in the outpatient and inpatient departments of our hospital were collected; according to the INBONE® total ankle system surgery process, the surgery model and surgical osteotomy were finished using MIMICS based on computer simulation method. The shortest distance was measured between the center point and the anterior, posterior, medial, and lateral, respectively, to ensure the precise position of the ankle replacement prosthesis by digital simulation surgery. The relationship between the two variables was analyzed by bivariate correlation analysis.

RESULTS

The dataset of this study included 48 cases of the sub-data set (26 males and 22 females) and included 27 cases of left ankle and 21 cases of right ankle. The average medial malleolar angle was 18.67°± 2.87°, the average amount of bone resection was 12.13 ± 1.86 cm³ , the mid-anterior distance was 1.72 ± 0.19 cm, the mid-posterior distance was 2.00 ± 0.19 cm, the ratio of mid-anterior to mid-posterior was 0.87, the mid-medial distance was 1.26 ± 0.17 cm, the mid-lateral distance was 1.19 ± 0.16 cm, and the ratio of mid-medial to mid-lateral was 1.06. After osteotomy, the anteroposterior diameter was 3.73 ± 0.32 cm, the transverse diameter was 2.46 ± 0.27 cm, and the ratio of anteroposterior diameter to transverse diameter was 1.53. In the bottom view, the shape after osteotomy is rectangular. The mid-anterior distance was strongly negatively correlated with age, the mid-anterior distance and the amount of bone resection, the mid-medial distance and the amount of bone resection, the mid-lateral distance and the amount of bone resection, the mid-lateral distance and the anteroposterior diameter, the anteroposterior diameter and the transverse diameter were all strongly positively correlated.

CONCLUSION

The projection point of the lower tibia centerline on the tibial horizontal osteotomy surface is located at a position slightly anterior to the midpoint of the transverse diameter after ankle arthroplasty. The rational positioning of the total ankle replacement is located at both a position slightly anterior to the midpoint of the transverse diameter and midpoint of the anteroposterior diameter, which can be used as a reference method before total ankle arthroplasty surgery.

Effectiveness of Ilizarov Ankle Arthrodesis in the Treatment of End-Stage Varus Ankle Osteoarthritis: A Retrospective Study

Objective

To evaluate the outcomes of Ilizarov ankle arthrodesis in the treatment of end‐stage varus ankle osteoarthritis (OA).

Methods

This was a retrospective study of 63 patients with varus ankle OA who underwent Ilizarov ankle arthrodesis between June 2013 and December 2018. There were 24 males and 39 females with an average age of 56.57 ± 4.45 years (range, 47–64 years). Thirty‐six cases were affected on the left side, and 27 were affected on the right side. The patients' mean body mass index (BMI) was 25.18 ± 2.93 kg/m². According to the modified Takakura staging criteria, there were 18 cases of stage 3b (28.57%) and 45 cases of stage 4 (71.43%). Nine patients were primary (14.29%), 48 were traumatic (76.19%), and six were caused by rheumatoid OA (9.52%). Functional assessments were performed according to the American Orthopedic Foot and Ankle Society (AOFAS) ankle‐hindfoot score, Ankle Osteoarthritis Scale (AOS), and visual analogue scale (VAS). The tibial anterior surface angle (TAS), coronal plane tibial‐talar angle (CPT), talar tilt angle (TT), deformity angle (DA), and tibial lateral surface angle (TLS) were assessed on X‐ray films.

Results

The average operation time was 147.84 ± 13.67 min (range, 135–168 min). The average follow‐up time was 34.24 ± 8.72 months (range, 24–61 months). Bony fusion was achieved in all ankles, and the fusion time was 12.43 ± 1.99 weeks on average. The average AOFAS score at the final follow‐up increased from 42.14 ± 8.66 to 80.90 ± 6.80. The average VAS score and AOS pain and disability scores at the final follow‐up decreased from 7.29 ± 1.27 to 2.24 ± 0.94, from 67.94 ± 7.68 to 27.92 ± 5.82, and from 71.64 ± 9.37 to 41.32 ± 8.99, respectively. The average TAS, CPT, and TLS at the final follow‐up increased from 77.76° ± 4.44° to 89.81° ± 1.25°, from 69.04° ± 3.73° to 90.43° ± 1.80°, and from 82.14° ± 3.77° to 88.67° ± 2.50°, respectively. The average TT and DA at the final follow‐up decreased from 8.76° ± 4.30° to 2.05° ± 1.28° and from 20.95° ± 3.73° to 1.57° ± 0.93°, respectively. Three patients developed superficial pin tract infections, all settled with local dressing and antibiotic treatment. Two patients were found to have subtalar arthritis and underwent conservative treatment.

Conclusion

Ankle arthrodesis using the Ilizarov technique is efficient in treating end‐stage varus ankle OA.

A pilot randomised control trial of the efficacy of stability-based training with visualisation for people with chronic ankle instability

Chronic ankle instability (CAI) is associated with recurring symptoms that inhibit daily activity. Stability-based rehabilitative training is recommended for CAI. Visualisation (VIS) produces real-time feedback using motion capture and virtual reality. This pilot study aimed to determine the feasibility, adherence, safety, and efficacy of incorporating VIS into stability training for people with CAI. Efficacy was examined through effect of VIS training on dynamic stability, perception of stability, and rehabilitative experience. Individuals with CAI completed a 4-week stability-based training programme with VIS, or without visualisation (NO-VIS). Participants completed the Star Excursion Balance Test (SEBT) and Cumberland Ankle Instability Tool (CAIT) prior to, and after training. Enjoyment of training was recorded using the Physical Activity Enjoyment Scale (PACES-8). Of 17 participants (VIS = 10, NO-VIS = 7), there were 2 drop outs (VIS = 1, NO-VIS = 1). No adverse events were reported, and participant drop-out was due to injury unrelated to the study. The VIS group showed a significantly greater increase in average SEBT reach distance (d = 1.7, p = 0.02). No significant differences were reported for the CAIT or PACES-8. This study supports the feasibility and safety of stability-based training with VIS in those with CAI. The enhanced performance outcome on the SEBT suggests VIS may enhance stability-based training.

Total ankle arthroplasty results using fixed bearing CT-guided patient specific implants in posttraumatic versus nontraumatic arthritis

BACKGROUND

Patients who undergo total ankle arthroplasty (TAA) for end-stage posttraumatic ankle osteoarthritis have previously reported more complications and lower satisfaction than those with non-traumatic etiologies. The purpose of this study was to evaluate clinical and radiographic outcomes in these two patient groups after TAA using a newer generation implant.

METHODS

Patients underwent TAA with a third generation implant using CT-based patient-specific cutting guides. Patients were evaluated clinically using the Foot and Ankle Ability Measure (FAAM) and radiographically at a mean follow up of 32, and 24 months respectively.

RESULTS

Forty-one patients were studied (26 posttraumatic, 15 nontraumatic). There were no significant differences between the two study groups in FAAM scores (p=0.3423) and radiographic measurements.

CONCLUSION

We were able to show comparable results in terms of patient satisfaction, short term clinical and radiographic results between traumatic and nontraumatic patients using newer patient specific implant systems.

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.

Radiological assessments and clinical results of intra-articular osteotomy for traumatic osteoarthritis of the ankle

INTRODUCTION

Traumatic osteoarthritis of the ankle joint caused after malleolar fractures of the ankle and tibial plafond fractures are frequently observed in comparatively young and highly active patients. Since the ankle movement in these patients is in general, comparatively favorable, orthopedists may sometimes have difficulty in deciding on a treatment policy. In our department, when treating traumatic osteoarthritis patients having a movable range within their ankle joints, we proactively applied distal tibial oblique osteotomy (DTOO) developed by Dr. Teramoto in 1994 or intra-articular osteotomy developed based on DTOO concepts such as distal tibial intra-articular osteotomy (DTIO) and distal fibular oblique osteotomy (DFOO).The objectives of the current study are to radiologically assess the ankle joint after intra-articular osteotomy for traumatic ankle osteoarthritis and evaluate the change in configuration of the ankle joint. This study summarizes the clinical results of intra-articular osteotomy obtained through the above-mentioned study.

PATIENTS AND METHODS

The subjects of this study were 20 patients diagnosed with traumatic osteoarthritis who were surgically treated for a total of 20 ankles. All patients underwent treatment with intra-articular osteotomy and were evaluated retrospectively for the following parameters: surgical procedure, fixation devices, clinical results based on the Japanese Society for Surgery of the Foot ankle/hindfoot scale (hereafter, JSSF scale) and post-operative adverse events. They were also assessed radiologically with pre- and post-operative anterior-posterior (AP) and lateral weight-bearing ankle radiographs.

RESULTS

The 20 patients consisted of 12 males and 8 females. The median age at surgery was 49 years old (range 14 - 87 years old) and the average follow-up period was 42 months (range 19 to 121 months). DTOO was applied to 10 cases, DFOO to 2 cases, DTOO and DFOO to 2 cases, medial-distal tibial intra-articular osteotomy (M-DTIO) and DFOO to 1 case, lateral-distal tibial intra-articular osteotomy (L-DTIO) and DFOO to 3 cases, M-DTIO followed by DTOO and DFOO to 1 case, and DTOO followed by low tibial osteotomy (LTO) to 1 case. Fixation devices utilized included circular external fixator for 15 cases, locking compression plate (LCP) to 3 cases, LCP and Kirschner-wire (K-wire) to 1 case, and screw and K-wire to 1 case. Radiological assessment revealed significant changes in the following parameters after surgery: tibial ankle surface angle (TAS, P= 0.0203), tibiotalar surface angle (TTS, P= 0.0021), medial malleolar angle (MMA, P= 0.0217), empirical axis (EA, P= 0.0019), fibular angle (FA, P= 0.0002), talar tilt angle (TTA, P= 0.0374), and tibial lateral surface angle (TLS, P= 0.0279). The JSSF scale also improved significantly after surgery (pre-operative JSSF scale: 51.1±11.0, post-operative JSSF scale: 89.2±8.2), p=0.0001.

CONCLUSION

Intra-articular osteotomy may change the radiological configuration of the ankle in a weight-bearing state. The present study showed very good short-term clinical results. Intra-articular osteotomy can prove a viable surgical option applicable for treatment of patients with traumatic ankle osteoarthritis having a reasonable range of motion within their ankle joints.

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.

Biomechanical evaluation of total ankle arthroplasty. Part I: Joint loads during simulated level walking

In total ankle arthroplasty, the interaction at the joint between implant and bone is driven by a complex loading environment. Unfortunately, little is known about the loads at the ankle during daily activities since earlier attempts use two- or three-dimensional models to explore simplified joint mechanics. Our goal was to develop a framework to calculate multi-axial loads at the joint during simulated level walking following total ankle arthroplasty. To accomplish this, we combined robotic simulations of level walking at one-quarter bodyweight in three cadaveric foot and ankle specimens with musculoskeletal modeling to calculate the multi-axial forces and moments at the ankle during the stance phase. The peak compressive forces calculated were between 720 and 873 N occurring around 77%-80% of stance. The peak moment, which was the internal moment for all specimens, was between 6.1 and 11.6 N m and occurred between 72% and 88% of the stance phase. The peak moment did not necessarily occur with the peak force. The ankle joint loads calculated in this study correspond well to previous attempts in the literature; however, our robotic simulator and framework provide an opportunity to resolve the resultant three-dimensional forces and moments as others have not in previous studies. The framework may be useful to calculate ankle joint loads in cadaveric specimens as the first step in evaluating bone-implant interactions in total ankle replacement using specimen specific inputs. This approach also provides a unique opportunity to evaluate changes in joint loads and kinematics following surgical interventions of the foot and ankle.

Biomechanical evaluation of total ankle arthroplasty. Part II: Influence of loading and fixation design on tibial bone-implant interaction

Finite element (FE) models to evaluate the burden placed on the interaction between total ankle arthroplasty (TAA) implants and the bone often rely on peak axial forces. However, the loading environment of the ankle is complex, and it is unclear whether peak axial forces represent a challenging scenario for the interaction between the implant and the bone. Our goal was to determine how the loads and the design of the fixation of the tibial component of TAA impact the interaction between the implant and the bone. To this end, we developed a framework that integrated robotic cadaveric simulations to determine the ankle kinematics, musculoskeletal models to determine the ankle joint loads, and FE models to evaluate the interaction between TAA and the bone. We compared the bone-implant micromotion and the risk of bone failure of three common fixation designs for the tibial component of TAA: spikes, a stem, and a keel. We found that the most critical conditions for the interaction between the implant and the bone were dependent on the specimen and the fixation design, but always involved submaximal forces and large moments. We also found that while the fixation design influenced the distribution and the peak value of bone-implant micromotion, the amount of bone at risk of failure was specimen dependent. To account for the most critical conditions for the interaction between the implant and the bone, our results support simulating multiple specimens under complex loading profiles that include multiaxial moments and span entire activity cycles.

End-stage Ankle Arthritis Treated by Ankle Arthrodesis with Screw Fixation Through the Transfibular Approach: A Retrospective Analysis

OBJECTIVE

To evaluate the clinical outcome of ankle arthrodesis with screw fixation through the transfibular approach for end-stage ankle arthritis.

METHODS

Data of 22 patients (28 ankles) with end-stage ankle arthritis admitted to the Department of Orthopedics and Surgery of the First Hospital of Jilin University from May 2015 to December 2018 were analyzed retrospectively. The study included 9 men and 13 women, with a mean age of 56.86 ± 11.27 years (range, 37-75 years). The mean duration of the disease was 11.36 ± 12.80 years (range, 3 months-50 years). A total of 16 patients had posttraumatic arthritis, 5 patients had osteoarthritis, and 1 patient had rheumatoid arthritis. There were 12 cases of the left ankle and 16 cases of the right ankle; 16 cases were unilateral and 6 were bilateral. The same surgical procedure was applied to all patients. Collected data included the operation time, intraoperative and postoperative blood loss, hospitalization time, bone union rate, time to bone union, and complications. The American Orthopedic Foot and Ankle Society (AOFAS) ankle hindfoot score and the visual analogue scale (VAS) were used to evaluate the preoperative status and the postoperative outcome at the last follow up.

RESULTS

The mean follow-up period was 26.14 ± 10.99 months. The mean operation time was 101.82 ± 33.33 min. The mean blood loss was 116.78 ± 68.86 mL during the procedure and 111.07 ± 52.18 mL after the procedure. The mean hospitalization time was 14.22 ± 5.42 days. Bone union of the ankle joint was achieved in all patients. The mean time to bone union was 14.83 ± 2.14 weeks. There was significant difference in the operation time between the patients undergoing unilateral and bilateral ankle arthrodesis. The AOFAS ankle hindfoot score increased from the preoperative value of 43.46 ± 4.39 points to 80.39 ± 5.37 points at the last follow up. During the same interval, the VAS score improved from 6.14 ± 0.80 points to 1.64 ± 0.73 points. The AOFAS ankle hindfoot score of patients who underwent unilateral ankle arthrodesis improved from the preoperative 43.19 ± 3.95 points to 81.75 ± 5.23 points at the last follow up, and the VAS score improved from 6.19 ± 0.83 points to 1.69 ± 0.70 points. The AOFAS ankle hindfoot score of patients undergoing bilateral ankle arthrodesis improved from the preoperative value of 43.83 ± 5.08 points to 78.67 ± 5.05 points at the last follow up, while the VAS score improved from 6.08 ± 0.82 points to 1.58 ± 0.79 points. There was significant difference in the maximum walking distance and walking on any surface between the patients undergoing unilateral and bilateral ankle arthrodesis. One patient developed superficial peroneal nerve palsy, which resolved within 1 year after the operation. In another patient, healing of the incision skin was delayed. During the follow-up period, none of the patients developed an infection of the incision or local skin necrosis; screw loosening, withdrawal, or breakage did not occur in any patient.

CONCLUSION

The ankle arthrodesis with screw fixation through the transfibular approach provides satisfactory clinical outcomes for end-stage ankle arthritis.

Effect of Microfracture on Functional Outcomes and Subchondral Sclerosis Following Distraction Arthroplasty of the Ankle Joint

BACKGROUND

Treatment for post-traumatic osteoarthritis (PTOA) of the ankle remains challenging. Distraction arthroplasty (DA) is an alternative for patients who are averse to or poor candidates for arthrodesis or joint replacement. The purpose of this study was to examine the role of microfracture (MFX) and concentrated bone marrow aspirate (CBMA) on the outcome of patients undergoing DA for end-stage PTOA of the ankle joint.

METHODS

Ninety-five patients who underwent DA for the treatment of end stage PTOA from 2009 to 2014 were selected from the hospital ankle registry. Demographic data, functional activity levels, complications, and radiographs taken at 6, 12, 24, and 36 months postoperatively were reviewed. Foot and Ankle Outcome Scores (FAOS) were obtained at the same time intervals. A total of 78 patients were included in this study. Interventions were divided into 4 groups for comparison: DA+MFX (n = 8), DA+MFX+CBMA (n = 35), DA+CBMA (n = 22), and DA alone (n = 13).

RESULTS

Patients undergoing DA+MFX or DA+MFX+CBMA had significantly worse motion (P = .003) when compared with DA alone. Patients undergoing MFX had significantly reduced postoperative joint space and a greater length of time to return to activity when compared to subgroups not using MFX (P = .01). The use of MFX was associated with significantly lower FAOS scores.

CONCLUSION

The current study showed no benefit from MFX when combined with DA in the treatment of PTOA. CBMA may have helped mitigate the adverse effect of MFX but conferred no benefit when used with DA alone. DA remains a useful alternative to ankle arthrodesis and arthroplasty in patients with PTOA. However, MFX and biologic augmentation using CBMA appeared to have no additional benefit.

LEVEL OF EVIDENCE

Level III, comparative study.

Autologous Osteochondral Graft for Early Posttraumatic Arthritis of Tibiotalar Joints After Comminuted Pilon Fractures in Young Patients

BACKGROUND

Posttraumatic arthritis of tibiotalar joints after AO/OTA type C3 pilon fractures, especially in young patients with a significant osteochondral defect in the tibial plafond joint surface, is a challenging situation. We report a joint-preserving technique using autologous osteochondral graft in combination with ankle distraction and supramalleolar osteotomy (SMOT), if necessary, to improve its outcome.

METHODS

Seventeen patients with an average age of 32.1 years with Takakura grade 1 to 3A posttraumatic arthritis of the tibiotalar joint after AO/OTA type C3 pilon fractures received osteochondral autograft transplantation, ankle distraction, and SMOT, when supramalleolar malalignment was present, between February 2010 and November 2015. The visual analog scale (VAS), Short-Form 36 (SF-36) score, American Orthopaedic Foot & Ankle Society (AOFAS) score, and ankle range of motion were used for outcome analysis. Radiographic assessment of any SMOT and the apparent joint space was performed. Fourteen patients were followed for an average of 18 months.

RESULTS

The VAS, SF-36, and AOFAS scores as well as the ankle range of motion all improved significantly at the last follow-up after the surgery (P < .01). No deep surgical site infection, donor site complication, nonunion, osteochondral block loosening, or resorption was noted. No secondary arthrodesis was needed at the end of follow-up.

CONCLUSION

Autologous osteochondral graft transplantation in combination with ankle distraction and SMOT was a promising joint-preserving technique for early posttraumatic arthritis of tibiotalar joint after severe pilon fractures in young patients.

LEVEL OF EVIDENCE

Level IV, case series.

Bipolar Fresh Osteochondral Allograft Transplantation of the Tibiotalar Joint: A Concise Mid-Term Follow-up of a Previous Report★

Despite advances in managing degenerative arthritis of the ankle joint, there are few optimal treatment options for young patients with symptomatic, end-stage degenerative disease. Popular surgical options consist of traditional arthrodesis and, more recently, arthroplasty. Additional techniques, including arthroscopic debridement and joint distraction, have gained little traction. An alternative option is bipolar fresh osteochondral allograft (OCA) transplantation of the tibiotalar joint. We previously reported on a cohort of 86 ankles that had undergone bipolar OCA of the tibiotalar joint and now present the results after longer, mid-term follow-up (mean, 9.2 years) of the same cohort. OCA survivorship was 74.8% at 5 years and 56% at 10 years. Of the patients with a surviving graft, 74% were satisfied with the results. At the latest follow-up, 86% reported better function and 79% reported less pain compared with preoperatively. Bipolar OCA transplantation of the tibiotalar joint is an effective alternative treatment for selected young patients with end-stage ankle arthritis who wish to avoid arthrodesis or prosthetic arthroplasty. LEVEL OF EVIDENCE:: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.