Total ankle arthroplasty: a radiographic outcome study

Outcomes of Transfibular Total Ankle Arthroplasty: Clinical and Radiographic Analysis of 130 Cases with Minimum 5-Year Follow-up

BACKGROUND

While most total ankle arthroplasty (TAA) procedures utilize an anterior approach for implantation, the Zimmer Biomet Trabecular Metal implant is unique in that it utilizes a lateral transfibular approach. We present the largest mid-term study to date to analyze the implant survivorship and clinical and radiographic outcomes of transfibular TAA at a minimum 5-year follow-up.

METHODS

We retrospectively identified and evaluated 130 ankles (122 patients; mean age, 60.8 years; 50% female) with a mean follow-up of 5.9 years (range, 5.0 to 10.1 years) after primary TAA performed between October 2012 and December 2018. Patient-reported outcome measures (PROMs) included the 12-item Short Form Health Survey (SF-12) Physical Component Summary (PCS) and Mental Component Summary (MCS), Ankle Osteoarthritis Scale (AOS) for pain and disability, and visual analog scale (VAS) for pain. Radiographic measurements for range of motion, coronal and sagittal alignment, and implant subsidence were evaluated. The presence of periprosthetic radiolucency was determined using a 12-zone classification system. Adverse events were reported using the Canadian Orthopaedic Foot and Ankle Society (COFAS) Reoperation Coding System (CROCS).

RESULTS

The cohort had mean postoperative values of 41.5 for the SF-12 PCS, 54.9 for the SF-12 MCS, 2.3 for VAS pain, 19.1 for AOS pain, and 28.5 for AOS disability. The postoperative tibiotalar range of motion was 7.5° of dorsiflexion and 17.3° of plantar flexion. A total of 42 valgus ankles (mean coronal tibiotalar angle, 10.4°; range, 1.0° to 25.3°) and 44 varus ankles (mean, -9.1°; range, -1.0° to -25.0°) were corrected to neutral. Twenty-six ankles (20%) had 1 zone of radiolucency, and none of the ankles had >7 zones. There were 3 cases of cysts (2.3%) and 0 cases of subsidence, septic or aseptic loosening, or fibular nonunion. Adverse events occurred in 47 ankles (36.2%) at a mean of 26.7 months, with the most common reoperation being medial gutter debridement (22 ankles; 16.9%). There were 2 ankles (1.5%) with acute infection treated with debridement, antibiotics, and polyethylene exchange with metal component retention. Overall implant survivorship, defined as retention of the metal components, was 100% at the time of final follow-up.

CONCLUSIONS

The clinical and radiographic data in this study suggest that transfibular TAA is an effective and durable treatment option for end-stage ankle arthritis, with excellent mid-term implant survivorship. Periprosthetic radiolucency was limited and did not lead to implant subsidence or loosening. The most common reoperation was medial gutter debridement.

LEVEL OF EVIDENCE

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

SPECT/CT of Total Ankle Arthroplasty

Use of SPECT/CT (Single Photon Emission Computed Tomography/Computed Tomography) is increasing providing additional information in patients with inconclusive clinical examination and unremarkable imaging findings presenting with chronic pain after total ankle arthroplasty. To differentiate the cause of pain after total ankle arthroplasty can be challenging. SPECT/CT combines structural and metabolic imaging as a hybrid tool leading to higher specificity and overall diagnostic accuracy presumably in cases of gutter impingement, prosthetic loosening, and osteoarthritis of adjacent joints. Moreover, SPECT/CT can complement diagnostic work up in periprosthetic joint infections. Basal tracer enhancement has to be considered for the interpretation of imaging findings.

The significance of heterotopic ossification following total ankle arthroplasty: a systematic review and meta-analysis

PURPOSE

The purpose of this systematic review and meta-analysis was to evaluate the prevalence and clinical significance of heterotopic ossification (HO) following total ankle replacement (TAR).

METHODS

During August 2023, the PubMed, Embase and Cochrane library databases were systematically reviewed to identify clinical studies reporting HO following TAR. Data regarding surgical characteristics, pathological characteristics, subjective clinical outcomes, ankle range of motion, radiographic outcomes, reoperation rates were extracted and analysed.

RESULTS

Twenty-seven studies with 2639 patients (2695 ankles) at a weighed mean follow-up time of 52.8 ± 26.9 months were included. The pooled prevalence rate was 44.6% (0.25; 0.66). The implant with the highest rate of HO was the INBONE I (100%) and BOX (100%) implants. The most common modified Brooker staging was grade 1 (132 patients, 27.0%). Random effects models of standardized mean differences found no difference in American orthopedic foot and ankle society (AOFAS) scores, visual analog scale scores (VAS) and ankle range of motion (ROM) between patients with HO and patients without HO. Random effects models of correlation coefficients found no correlation between AOFAS, VAS and ROM and the presence of HO. The surgical intervention rate for symptomatic HO was 4.2%.

CONCLUSION

This systematic review and meta-analysis found that HO is a common finding following TAR that is not associated with inferior clinical outcomes. Surgical intervention was required only for moderate-to-severe, symptomatic HO following TAR. This study is limited by the marked heterogeneity and low level and quality of evidence of the included studies. Further higher quality studies are warranted to determine the precise prevalence and impact of HO on outcomes following TAR.

SPECT/CT of Total Ankle Arthroplasty

Use of SPECT/CT (Single Photon Emission Computed Tomography/Computed Tomography) is increasing providing additional information in patients with inconclusive clinical examination and unremarkable imaging findings presenting with chronic pain after total ankle arthroplasty. To differentiate the cause of pain after total ankle arthroplasty can be challenging. SPECT/CT combines structural and metabolic imaging as a hybrid tool leading to higher specificity and overall diagnostic accuracy presumably in cases of gutter impingement, prosthetic loosening, and osteoarthritis of adjacent joints. Moreover, SPECT/CT can complement diagnostic work up in periprosthetic joint infections. Basal tracer enhancement has to be considered for the interpretation of imaging findings.

Particularities on Anatomy and Normal Postsurgical Appearances of the Ankle and Foot

The anatomy of the ankle and foot is complex, allowing for a wide range of functionality. The movements of the joints represent a complex dynamic interaction. A solid understanding of the characteristics and actions of the anatomic elements helps explain the mechanisms and patterns of injury. This article reviews the anatomy, with special focus on concepts that are the object of recent study and the features that favor the development of symptoms. Good understanding of the surgical procedures helps in providing information to guarantee a favorable outcome. We review the commonly expected postsurgical appearances and the most common postsurgical complications.

Fixed-Bearing Trabecular Metal Total Ankle Arthroplasty Using the Transfibular Approach for End-Stage Ankle Osteoarthritis: An International Non-Designer Multicenter Prospective Cohort Study

This multicenter prospective cohort study assessed the safety and performance of the Trabecular Metal Total Ankle System (TM Ankle; Zimmer) for primary total ankle arthroplasty (TAA).

METHODS

One hundred and twenty-one consecutive patients qualifying for primary TAA were enrolled in the study. All patients received the TM Ankle implant. Clinical outcome examinations and radiographic evaluations were conducted at 6 weeks, 6 months, 1 year, 2 years, and 3 years. Patient-reported outcome measures (PROMs) were evaluated with use of the EuroQol-5 Dimensions questionnaire (EQ-5D), Ankle Osteoarthritis Scale (AOS), American Orthopaedic Foot & Ankle Society questionnaire (AOFAS), and patient satisfaction at each time point. Complications were classified according to the Canadian Orthopaedic Foot and Ankle Society (COFAS) system.

RESULTS

The average AOFAS, EQ-5D, AOS pain, and AOS difficulty scores showed significant improvement at 6 weeks, 6 months, 1 year, 2 years, and 3 years as compared with the preoperative baseline (p < 0.001). The Kaplan-Meier survival estimate for revision when used in primary cases was 97.35% at 3 years. During the 3 years of follow-up, 9 patients showed abnormal radiographic findings. Two ankles had intraoperative complications, 38 had complications that were non-surgical or device-related, and 3 ankles underwent revision.

CONCLUSIONS

The results of the present study indicated that patient well-being significantly increased following TAA with use of the TM Ankle. Radiographic parameters also demonstrated a low incidence of abnormal findings.

LEVEL OF EVIDENCE

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

The Bologna-Oxford ankle replacement: a case series of clinical and radiological outcomes

PURPOSE

The Bologna-Oxford (BOX®) total ankle arthroplasty (TAA) is a three-component mobile-bearing implant gaining popularity in Europe. We aimed to analyse the outcomes of this TAA.

METHODS

We retrospectively analysed data on 34 consecutive BOX® TAAs performed at a single centre with a mean follow-up of 58 months. Radiographic outcomes, such as periprosthetic lucency and alignment, were measured and recorded. Prospectively captured clinical scores and range of movement (ROM) were also recorded.

RESULTS

There were significant improvements in patient-reported outcome scores recorded in the Manchester-Oxford Foot Questionnaire (MOxFQ) for pain (43.8 ± 20.2, p < 0.001), standing and walking (55.6 ± 19.8, p < 0.001), social activities (45.0 ± 26.9, p < 0.02) and visual analogue score (VAS) (3.1 ± 2.5, p < 0.001). Mean improvement in ROM postoperatively was 18.7° (p < 0.001), with post-operative dorsiflexion 8.8° (10°-25°) and plantar flexion 32.6° (20°-40°). There was evidence of asymptomatic lucency on five radiographs (15%), which was present in 10% at three years. Nine patients had complications (26%): six (18%) requiring secondary surgery and one requiring revision (3%) for infection.

CONCLUSIONS

We have demonstrated 97% survivorship at a mean of 58 months. There are maintained improvements in clinical and radiological outcomes and reoperation that are consistent with the literature.

Peri-prosthetic bone cysts after total ankle replacement. A systematic review and meta-analysis

BACKGROUND

Periprosthetic cystic osteolysis is a well-known complication of total ankle replacement. Several theories have been proposed for its aetiology, based on individual biomechanical, radiological, histopathology and outcome studies.

METHODS

Studies that met predefined inclusion/exclusion criteria were analysed to identify literature describing the presence of peri-prosthetic ankle cystic osteolysis. Quantitative data from the selected articles were combined and statistically tested in order to analyse possible relations between ankle peri-prosthetic bone cysts and specific implant characteristics.

RESULTS

Twenty-one articles were elected, totalizing 2430 total ankle replacements, where 430 developed peri-prosthetic cystic osteolysis. A statistically significant association (P<.001) was found between the presence of bone cysts and non-anatomic implant configuration, hydroxyapatite-coating, mobile-bearing and non tibial-stemmed implants. No significant association existed between the type of constraining and the presence of cysts (P>.05).

CONCLUSIONS

Non-anatomic, mobile-bearing, hydroxyapatite-coated and non tibial-stemmed total ankle replacements are positively associated with more periprosthetic bone cysts.

Cuff tear arthropathy shoulder hemiarthroplasty: a radiographic outcome study

OBJECTIVE

Cuff tear arthropathy (CTA) head prosthesis has recently become an alternative to standard shoulder hemiarthroplasty in patients with severe cuff disease by offering an increased surface area and decreased impingement. The purpose of this study is to evaluate the radiographic outcomes of CTA prosthesis and to correlate them with clinical outcomes.

MATERIALS AND METHODS

In this retrospective study of CTA hemiarthroplasties over an 11-year period, two radiologists reviewed pre-/postoperative radiographs and clinical data. Radiographic complications were correlated with subsequent surgery using Cox regression models. Rates of surgical revision and radiographic complications over time were estimated using Kaplan-Meier curves.

RESULTS

Ninety-seven CTA hemiarthroplasties were identified in 92 patients (5 bilateral) with a mean patient age of 68.7 years. Mean radiographic follow-up was 12 months with a mean of 3.3 radiographs per prosthesis. Twenty-six arthroplasties (26.8%) experienced at least one radiographic complication, including acromion remodeling (19.5%), anterior-posterior subluxation (5.2%), periprosthetic fracture (4.1%), glenoid remodeling (3.1%), hardware loosening (2.1%), superior subluxation (2.1%), and subsidence (1.0%). Eight cases underwent revision surgery (8.2%). The occurrence of a postoperative radiographic complication was associated with increased risk of surgical revision (hazard ratio 11.5, 95% CI: 2.4-55.7, p = 0.002); 73.5% of radiographic complications occurred by 3 months after the initial surgery (complication rate of 23.3%) based on Kaplan-Meier curve analysis.

CONCLUSION

Radiographic complications after CTA head hemiarthroplasty are common with most occurring by 3 months after surgery and are highly associated with surgical revision.

Total Ankle Arthroplasty: An Imaging Overview

With advances in implant technology, total ankle arthroplasty (TAA) has become an increasingly popular alternative to arthrodesis for the management of end-stage ankle arthritis. However, reports in the literature do not focus on the imaging features of TAA. Through a literature review, we demonstrate basic design features of the current ankle arthroplasty system, and the normal and abnormal postoperative imaging features associated with such devices. Pre- and postoperative evaluations of ankle arthroplasty mainly include radiography; in addition, computed tomography and magnetic resonance imaging provide further characterization of imaging abnormalities. Familiarization with multimodal imaging features of frequent procedural complications at various postoperative intervals is important in radiological practice.

The Salto Talaris XT Revision Ankle Prosthesis

The Salto Talaris XT Revision Ankle Prosthesis is an anatomically designed fixed-bearing prosthesis available in the United States based on the design of previous Salto systems. The Salto Talaris XT Revision Ankle Prosthesis design optimizes surface area, cortical contact, and ultrahigh-molecular-weight polyethylene conformity. Two tibial component designs, both with the same base plate dimensions, are available, the standard conical fixation plug affixed to a short keel and a long-stemmed version. The author presents an overview of the Salto Talaris XT Revision Ankle Prosthesis surgical technique and pearls for successful application.