Imaging of Bone Perfusion and Metabolism in Subjects Undergoing Total Ankle Arthroplasty Using 18F-Fluoride Positron Emission Tomography

Median age of patients undergoing total ankle replacement has not significantly changed between 1999 and 2023: A systematic review of prospective studies

INTRODUCTION

Total ankle replacement (TAR) is an effective treatment for end-stage osteoarthritis. The aim of this systematic review was to assess the age of patients undergoing TAR in prospective comparative studies. Our hypothesis is that the age reported in most recent papers might be lower than those reported in older papers.

METHODS

This systematic review was performed using Pubmed, Scopus, EMBASE and Cochrane databases. Only Level I and II studies dealing with TAR were included. Data regarding demographics, study design, number of cohorts in each study, year of publication and year/years in which surgery was performed were extracted. A two-fold analysis was conducted building groups of patients based on the year of publication and creating 1) two groups (before and after the median year) and 2) three groups (using tertiles) in order to compare age of patients operated in different period of times. A comparison was also performed considering the median year of surgery for patients undergoing TAR.

RESULTS

Overall 59 cohorts (42 studies, published between 1999 and 2023; median year of publication: 2017) were included (6397 ankles, 6317 patients, median age 63 years). The difference between the median age for 27 cohorts published until 2016 (weighted median 63 years; IQR, 62.5-64) and the median age for 32 cohorts published after 2017 (weighted median 63.2 years; IQR, 63-67.8) was not statistically significant (p = 0.09). The division in tertiles did not reveal any significant change in the weighted median age at surgery (T1 (1999-2014; 63.2 years; IQR, 62.8-64.1), T2 (2015-2018; 63 years; IQR,63-63.5) and T3 (2019-2023; 63.2 years; IQR, 62.6-67.8)) over time (p = 0.65). The median age of patients operated between 1999 and 2008 vs 2009 and 2023 (data from 48 cohorts) was not different either (p = 0.12).

CONCLUSION

According to this review of prospective studies published between 1999 and 2023, the median age for patients undergoing TAR over the last two decades has been 63 years, remaining steady with no significant changes over time.

LEVEL OF EVIDENCE

Level II - systematic review including Level I and Level II studies.

Midterm Survivorship of the INBONE II Total Ankle Arthroplasty

BACKGROUND

The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. Although outcomes of the INBONE I have been published, there is limited midterm survival data for the INBONE II. The purpose of this study was to determine the radiographic and patient-reported outcomes, and survivorship of this prosthesis in patients with a minimum 5-year follow-up.

METHODS

We retrospectively identified 51 ankles (46 patients) from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases had minimum clinical follow-up of 5 years (mean, 6.4; range 5-9). Median age was 66 years (range 42-81) and median BMI was 27.5 (range 20.1-33.0). A chart review was performed to record the incidence of revision and reoperation. Preoperative and postoperative radiographs were analyzed to assess the coronal tibiotalar alignment (TTA), the talar inclination angle, and the presence of periprosthetic lucencies and cyst formation. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared. Survivorship was determined by incidence of revision, defined as removal of a metallic component.

RESULTS

The survivorship at 5 years was 98% and the rate of reoperation was 7.8% (n = 4); 2 patients underwent irrigation and debridement for infection, 1 patient underwent a medializing calcaneal osteotomy, and 1 patient underwent open gutter debridement, 1 patient underwent a revision of a subsided talar component at 3.2 years after index surgery. Average postoperative TTA was 88.6 degrees, with 42 rated as neutral (85-95 degrees), 2 varus (<85 degrees), and no valgus (>95 degrees) ankles. At final follow-up, asymptomatic periprosthetic cysts were observed in 8 patients. All FAOS domain scores improved between preoperative and final follow-up.

CONCLUSION

At midterm follow-up, we observed significant improvement in radiographic alignment and patient-reported outcome scores for the INBONE II total ankle prosthesis. In addition, this cohort has had a relatively low reoperation rate and high survivorship.

LEVEL OF EVIDENCE

Level IV, case series.

Correlation of the quantitative methods for the measurement of bone uptake and plasma clearance of 18F-NaF using positron emission tomography. Systematic review and meta-analysis

PURPOSE

¹⁸F-NaF PET is valuable for detecting bone metabolism through osteoblastic activity in the assessment of bone disease. Hawkins, Patlak, and standardised uptake value (SUV) are the most common quantitative measurements used to evaluate bone metabolism. This systematic review evaluates the correlation between quantitative positron emission tomography (PET) methods and to compare their precision.

METHODS

A systematic search in Medline, PubMed, SCOPUS, and Web of Science was undertaken to find relevant papers published from 2000. All studies with human adults undergoing ¹⁸F-NaF PET, PET/CT, or PET/MRI were included except for subjects diagnosed with non-diffuse metabolic bone disease or malignancy. Quality Assessment Tool for Studies of Diverse Designs (QATSDD) was used to assess risk of bias. A qualitative review and meta-analysis using Hedges random-effect model was used producing summary size effects of the correlation between methods in healthy and unhealthy bone sites and assessing study heterogeneity.

RESULTS

228 healthy and unhealthy participants were included across 12 studies resulted from the systematic search. One-third of studies had a moderate quality percentage while the rest had relatively high quality. The pooled correlation coefficient in meta-analysis showed a high correlation of more than 0.88 (0.71-1.05. 95 %CI) between SUV and Hawkins and more than 0.96 (0.88-1.03. 95 %CI) between Patlak and Hawkins within all subgroups, suggesting all methods yield similar results in healthy and unhealthy bone sites. SUV has the lowest precision error followed by Patlak while Hawkins method showed the highest precision error.

CONCLUSION

Patlak is the best within research and SUV is better within clinical practice.

Novel Musculoskeletal and Orthopedic Applications of 18F-Sodium Fluoride PET

PET imaging with ¹⁸F-sodium fluoride (NaF), combined with computed tomography or magnetic resonance, is a sensitive method of assessing bone turnover. Although NaF-PET is gaining popularity in detecting prostate cancer metastases to bone marrow, osseous changes represent secondary effects of cancer cell growth. PET tracers more appropriate for assessing prostate cancer metastases directly portray malignant activity and include ¹⁸F-fluciclovine and prostatic specific membrane antigen ligands. Recent studies investigating NaF-PET suggest utility in the assessment of benign musculoskeletal disorders. Emerging applications in assessing traumatic injuries, joint disease, back pain, orthopedic complications, and metabolic bone disease are discussed.