Diagnostic Criteria and Treatment of Acute and Chronic Periprosthetic Joint Infection of Total Ankle Arthroplasty

Background: Prosthetic joint infection (PJI) after total ankle arthroplasty (TAA) is a serious complication that results in significant consequences to the patient and threatens the survival of the ankle replacement. PJI in TAA may require debridement, placement of antibiotic spacer, revision arthroplasty, conversion to arthrodesis, or potentially below the knee amputation. While the practice of TAA has gained popularity in recent years, there is some minimal data regarding wound complications in acute or chronic PJI of TAA. However, of the limited studies that describe complications of PJI of TAA, even fewer studies describe the criteria used in diagnosing PJI. This review will cover the current available literature regarding total ankle arthroplasty infection and will propose a model for treatment options for acute and chronic PJI in TAA. Methods: A review of the current literature was conducted to identify clinical investigations in which prosthetic joint infections occurred in total ankle arthroplasty with associated clinical findings, radiographic imaging, and functional outcomes. The electronic databases for all peer-reviewed published works available through January 31, 2018, of the Cochrane Library, PubMed MEDLINE, and Google Scholar were explored using the following search terms and Boolean operators: “total ankle replacement” OR “total ankle arthroplasty” AND “periprosthetic joint infection” AND “diagnosis” OR “diagnostic criteria.” An article was considered eligible for inclusion if it concerned diagnostic criteria of acute or chronic periprosthetic joint infection of total ankle arthroplasty regardless of the number of patients treated, type of TAA utilized, conclusion, or level of evidence of study. Results: No studies were found in the review of the literature describing criteria for diagnosing PJI specific to TAA. Conclusions: Literature describing the diagnosis and treatment of PJI in TAA is entirely reliant on the literature surrounding knee and hip arthroplasty. Because of the limited volume of total ankle arthroplasty in comparison to knee and hip arthroplasty, no studies to our knowledge exist describing diagnostic criteria specific to total ankle arthroplasty with associated reliability. Large multicenter trials may be required to obtain the volume necessary to accurately describe diagnostic criteria of PJI specific to TAA. Level of Evidence: Level III, systematic review

Comparing the Efficacy of True-Volume Analysis Using Magnetic Resonance Imaging With Computerized Tomography and Conventional Methods of Evaluation in Cystic Osteochondral Lesions of the Talus: A Pilot Study.

UNLABELLED: METHODS: With IRB approval, an institutional radiology database was queried for patients with cystic OLT that had undergone and failed microfracture and had compatible CT and MR scans between 2011 and 2016. Five lesions, previously analyzed and described in the literature using CT true-volume, were selected. 10 orthopedic surgeons independently estimated the volume of these 5 OLT via standard MRI. Next, 3D reconstructions were created and morphometric true-volume (MTV) analysis measurements of each OLT were generated. The percent change in volumes from CT and MR was compared based upon MTVs determined from 3D reconstructive analysis. RESULTS: The volume calculated using conventional methods in CT and MR scans grossly overestimated the size by of the OLT by 285-864% and 56-374% respectively when compared to 3D true-volume analysis of those CT and MR scans. CONCLUSIONS: This study demonstrates that true-volume is more accurate for calculating lesion size than conventional methods. Additionally, when comparing MRI and CT, thin slice CT true-volume is superior to MRI true-volume. True-volume calculation improves accuracy with CT and MRI and should be recommended for use in revision OLT cases

Biomechanical Analysis of a Semitendinosus Allograft versus Achilles Turndown for Reconstruction of Large Segmental Achilles Defects

Category: Sports. Introduction/Purpose: Large segmental Achilles tendon defects present a difficult problem to treating surgeons. Multiple procedures have been utilized to reconstruct these defects, but no studies have evaluated the comparative tensile strength of the various repair methods. Our institution has recently described the use of a dual semitendinosus allograft for Achilles reconstruction. Advantages of this procedure include eliminating donor site morbidity and providing an increased surface area for healing and tendon incorporation. Our study investigated the tensile strength of this novel technique as compared to a standard myofascial turndown procedure. We hypothesized that no differences in biomechanical properties would be found between dual semitendinosus reconstruction and Achilles myofascial turndown reconstruction. Methods: An 8-cm segmental Achilles defect was created in both specimens of nine matched pair, cadaveric lower extremities. The specimens in each pair were randomly assigned to undergo allograft or turndown reconstruction. The myofacial turndown was secured distally with modified Kessler sutures of 0 braided polyester sutures through bone tunnels in the calcaneus and proximally with multiple interrupted figure-of-8 polyester braid sutures. Semitendinosus grafts were anchored proximally with a Pulvertaft weave and then distally through two bone tunnels within the calcaneus and sutured together around the posterior heel with similar polyester sutures. The foot was disarticulated through the subtalar joint and the Achilles was dissected free of excess soft tissues. The constructs were mounted onto a load frame and differential variable reluctance transducers were applied to the construct. Specimens were preconditioned and then loaded axially. Tensile forces were recorded at 10 mm of displacement and at failure Results: Semitendinosus allograft failure occurred via calcaneal bone bridge fracture in 8 of 9 specimens, and all myofascial turndowns failed through suture pullout through the fascial tissue at its insertion. None of the specimens failed at the MTS grip sites or via de novo tendon substance rupture. Average ultimate tensile strength of the semitendinosus allograft reconstruction was 290.9± 83.2 N compared to that of the turndown repair which was 140.7± 43.5 N. At 10 mm of displacement, average tensile strength of the allograft repair was 156.9 ± 29.7 N versus the turndown repair at 101.2 ± 20.0 N. Strength differences between the two repairs were significant at both failure and 10 mm displacement (p < 0.001). Conclusion: Dual semitendinosus allograft reconstruction demonstrates superior tensile strength properties when compared to myofascial turndown in a cadaveric model of large Achilles tendon defects

sj-docx-1-fas-10.1177_19386400241230597 – Supplemental material for Charcot Neuroarthropathy Is Associated With Higher Rates of Phantom Limb After Lower Extremity Amputation

Supplemental material, sj-docx-1-fas-10.1177_19386400241230597 for Charcot Neuroarthropathy Is Associated With Higher Rates of Phantom Limb After Lower Extremity Amputation by Hannah H. Nam, Brandon J. Martinazzi, F. Jeffrey Lorenz, Gregory J. Kirchner, Vincenzo Bonaddio, Adeshina Adeyemo, Kempland C. Walley and Michael C. Aynardi in Foot & Ankle Specialist</p

Metal Artifact Reduction MRI for Sagittal Balance Evaluation of Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: Surgical restoration of the anatomical relationship between talus and tibia is considered crucial for longevity of total ankle arthroplasty (TAA). Weight-bearing (WB) radiographs are the current standard for evaluating the sagittal balance alignment, which are, however, prone to rotational misalignment and potentially altered measurements. Metal artifact reduction sequence (MARS) MRI is a cross-sectional technique that minimizes implant-induced artifacts and affords the visualization of bone-implant interfaces and periprosthetic bone without distortions. Although not weight-bearing, MARS MRI offers the ability to align the image plane to the true sagittal axis of the talar implant and anatomically correct measurements. Therefore, the purpose of this study was to compare sagittal balance alignment measurements on MARS MR images and standard WB radiographs in patients with TAA. Methods: In this IRB-approved, prospective study, 23 subjects [10 men/13 women, age 60(41-73) years; 13(3-24) months post- op] underwent MARS MRI and standard lateral WB radiographs. Standardized MARS MR images were obtained in alignment to the sagittal talar component axis and use of a boot-shaped MRI coil. Maximum-intensity-projection MR images that resemble lateral radiographs were created to bring anatomic landmarks, such as lateral talar process, talonavicular joint line, talar implant, tibial shaft, and posterior talus into one single image. Three board-certified foot ankle surgeons performed sagittal balance alignment measurements twice in an independent, random and blinded fashion. The second set of measurements was obtained 1 months after the first assessment. In accordance with published measurements, lateral talar station (LTS), tibial axis-to-talus (T-T) ratio, and normalized tibial axis-to-lateral-process (T-L) distance were measured. Pearson correlation coefficient (r), Concordance-Correlation-Coefficient (CCC) and Intraclass-Correlation-Coefficient (ICC) were used for statistical analysis. Bonferroni-corrected p-values ≤ 0.01 were considered significant. Results: The intra-observer agreement was excellent for radiographic (CCC = 0.93 - 0.97) and MRI (CCC = 0.90 - 0.97) measurements. Inter-observer agreements were good-to-excellent with overall higher agreements for MRI (ICC = 0.76 - 0.93) than for radiography (ICC = 0.58 - 0.95) measurements. There was statistically significant inter-method correlation between radiographic and MRI measurements including LTS (r=0.83, p < 0.001), T-T ratio (r=0.86, p < 0.001) and normalized T-L distance (r=0.72, p < 0.001). The T-T ratios of radiographs and MRI were statistically not different (p=0.36), whereas LTS and normalized T-L distance were significantly lower on MR images when compared with radiographs (p < 0.001). Conclusion: Sagittal balance measurements performed on standardized weight-bearing radiographs and standardized MARS MR images demonstrate substantial correlation and similarity. Given its high inter- and intra-observer agreement, MARS MRI may be helpful for the evaluation of sagittal balance following TAA