Accuracy of Cutaneous Landmarks Compared to Ultrasound to Locate the Calcaneal Footprint of the CFL

The purpose was to determine the accuracy of the techniques of Lopes et al. and Michels et al., compared to ultrasound, to locate the center of the calcaneal footprint of the CFL in healthy volunteers. The authors recruited 17 healthy adult volunteers at 1 center with no current ankle pathologies and no previous surgical antecedents on either ankle. The authors recorded the age, sex, height, BMI, and ankle side for each volunteer. Measurements were made on both ankles of the 17 volunteers to increase the sample size and ensure less dispersion of data, independently by 2 surgeons: 1 senior surgeon with 15 years' experience and 1 junior with 3 years' experience. The location of the center of the calcaneal footprint of the CFL was determined by each surgeon using 3 methods: (1) the cutaneous technique of Lopes et al., (2) the cutaneous technique of Michels et al., and (3) ultrasound imaging. The 17 volunteers (34 feet) had a mean age of 26.3 ± 8.7 and a BMI of 21.7 ± 2.9. The Michels point was significantly closer (4.6 ± 3.7 mm) than the Lopes point (11.1 ± 5.4 mm) to the true center of the calcaneal footprint of the CFL determined by ultrasound, notably in the vertical direction. The Michels point was located significantly closer to the true center of the calcaneal footprint of the CFL and demonstrated less dispersion than the Lopes point, indicated by significantly lower absolute mean deviation from the true center of the calcaneal footprint of the CFL, and that ultrasound is therefore preferred to locate the footprint the CFL.

Intra-articular fibrous bands at the tibiotalar joint: diagnosis and outcomes of arthroscopic removal in 4 ankles

The authors retrieved the records of 4 patients that exhibited unusual structural anomalies or pathologies, notably the presence of a fibrous band at the anterior aspect of the tibiotalar joint, observed during arthroscopic exploration or treatment between January and December 2019. Only 1 patient had surgical antecedents on the ipsilateral ankle (extra-articular tenodesis 10 years earlier). The remaining 3 patients had no surgical antecedents on the ipsilateral ankle. The fibrous band was removed in all patients during arthroscopic Brostöm procedure or exploration. For the first 3 patients, the intra-articular fibrous band was not observed prior to arthroscopy by either the senior surgeon or radiologist on any of the images (2 MRIs and 1 CTA), but retrospective inspection confirmed that the intra-articular fibrous band was present but had been overlooked.

At a follow-up of 22.3 ± 5.0 months (range, 15–26), all patients reported a decrease in pVAS (− 5.0 ± 2.6, range, 2–8), and an improvement in AOFAS (51.0 ± 17.7, range, 26–65), EFAS (14.5 ± 8.7, range, 6–23) and EFAS sport (8.0 ± 5.3, range, 2–10).

This case report corroborates the findings of an earlier discovery of an intra-articular fibrous band in 4 ankles, with more detailed information for clinical and radiologic diagnosis, as well as outcomes of arthroscopic removal. Clinicians should beware of such foreign bodies in the ankle, particularly in patients with history of sprains, and consider arthroscopic removal in cases with persistent pain and/or functional impairment.

Incidence and outcomes of revision surgery after first metatarsophalangeal joint arthrodesis: Multicenter study of 158 cases

INTRODUCTION

First metatarsophalangeal (MTP1) joint arthrodesis, described as a safe and effective procedure, has complications that may require surgical revision. These complications are rarely studied. The aim of this study was to determine the incidence and outcomes of revision surgery after MT1 arthrodesis.

HYPOTHESIS

The incidence of surgical revision after MTP1 arthrodesis is not insignificant; however, the outcomes are satisfactory.

MATERIALS AND METHODS

In this multicenter retrospective study between January 2014 and December 2015, 190 forefoot revisions in patients who had previously undergone MTP1 arthrodesis were included by 8 surgeons. There were no exclusion criteria and all patients had at least 1 year of follow-up. Over the same period, 958 primary MTP1 arthrodesis procedures were performed.

RESULTS

The mean time to revision was 4.6±10.9 years. At a mean follow-up of 20.5±7.4 months, 158 cases were available for analysis in 135 women and 20 men who had a mean age of 67.1±10.5 years. These revision procedures were carried out because of discomfort related to the hardware at the arthrodesis site (n=86, 54%), nonunion (n=22, 14%), malunion (n=13, 8%) metatarsalgia or claw toe (n=18, 11%) and first interphalangeal (IP1) joint disorders (n=13, 8%). The mean postoperative scores were 75±13.9 for the AOFAS and 65±19.6 for the SF36 total. In the nonunion cases, removal of the hardware led to better outcomes than repeating the arthrodesis procedure. Osteotomy in the malunion cases healed successfully. In the cases of IP1 osteoarthritis, secondary arthrodesis or arthroplasty led to good outcomes.

DISCUSSION

Relative to published results of primary MTP1 arthrodesis, the outcomes in our series of revision MTP1 arthrodesis surgery cases are practically equivalent, thus considered acceptable.

LEVEL OF EVIDENCE

IV, Retrospective study.

An automated approach to the design of decision tree classifiers

The classification of large dimensional data sets arising from the merging of remote sensing data with more traditional forms of ancillary data causes a significant computational problem. Decision tree classification is a popular approach to the problem. This type of classifier is characterized by the property that samples are subjected to a sequence of decision rules before they are assigned to a unique class. If a decision tree classifier is well designed, the result in many cases is a classification scheme which is accurate, flexible, and computationally efficient. This correspondence provides an automated technique for effective decision tree design which relies only on a priori statistics. This procedure utilizes canonical transforms and Bayes table look-up decision rules. An optimal design at each node is derived based on the associated decision table. A procedure for computing the global probability of correct classification is also provided. An example is given in which class statistics obtained from an actual Landsat scene are used as input to the program. The resulting decision tree design has an associated probability of correct classification of 0.75 compared to the theoretically optimum 0.79 probability of correct classification associated with a full dimensional Bayes classifier. Recommendations for future research are included.