Ultrasound and magnetic resonance imaging neurography assessment of diagnostic criteria in patients with carpal tunnel syndrome using electrophysiological tests as gold standard: A prospective study

Objectives

Evaluating peripheral neuropathy mainly relies on physical examination, patient history, and electrophysiological studies. High-resolution ultrasound is a fast, noninvasive modality for dynamic nerve assessment that enables the length of the nerve to be examined. Magnetic resonance imaging is preferred for examining deeper nerves with a high contrast resolution; its use shows excellent benefit in patients with atypical presentation, equivocal diagnosis, suspected secondary causes, and postsurgical relapse. We aimed to assess the measurements and criteria for both ultrasound and magnetic resonance neurography for the diagnosis of carpal tunnel syndrome, based mainly on the three measurements assessed by Buchberger et al.

Methods

This prospective study was conducted to test diagnostic accuracy. Thirty-two patients who presented clinically with, and were diagnosed by electrophysiological tests as having, carpal tunnel syndrome participated. Superficial ultrasound of the wrist joint was performed on all participants, followed by magnetic resonance imaging within 1 week of ultrasonography.

Results

The three main parameters of cross-sectional area measurement, distal nerve flattening, and flexor retinaculum bowing indices showed positive occurrences of 93.7%, 59.4%, and 59.4%, respectively; 90.6% of patients had decreased nerve echotexture. The diagnostic ability of magnetic resonance imaging was decreased when cross-sectional area measurements were used: positive results were achieved in 81.2% of patients, but the positive results showing the distal tunnel nerve increased flattening and bowed flexor retinaculum slightly decreased to 56.2% for each. A high T2 signal of the median nerve was observed in 90.6% of patients. In an agreement analysis, we found a statistically significant difference that supported the use of ultrasound as a primary diagnostic modality for carpal tunnel syndrome. However, magnetic resonance imaging improved tissue characterization and was a good diagnostic modality, with a statistically significant difference, for cases of secondary carpal tunnel syndrome, detection of the underlying entrapping cause, and early abnormality detection in the innervated muscle.

Conclusions

Our results demonstrate that ultrasound examination can be used as the first imaging modality after physician evaluation, with results comparable to those of electrophysiological studies for evaluating carpal tunnel syndrome and determining its cause. Magnetic resonance neurography examination is the second step in detecting secondary causes in cases with suspected early muscle denervation changes that cannot be elicited by ultrasound or in cases with equivocal results.

Chronological Changes in Sagittal Femoral Bowing after Primary Cementless Total Hip Arthroplasty: A Comparative 3D CT Study

Little is known about dynamic changes of femoral anatomy after total hip arthroplasty (THA), in particular about sagittal femoral bowing (SFB). A 3D CT study was designed to evaluate the chronological changes of SFB after cementless femoral stem implantation for primary THA. Ten patients who underwent unilateral primary THA with a cementless femoral stem, with 2 consecutive CT scans (extending from the fourth lumbar vertebra to the tibial plateaus), performed before THA and at least 3 years after THA, were enrolled. The 3D models of femurs were created using image segmentation software. Using the two CT scans, SFB values of the proximal and middle thirds were calculated on the replaced and untreated sides by two different observers. Eight anatomical stems and two conical stems were involved. The post-operative CT was performed at an average follow-up of 6.5 years after THA (range: 3-12.5). The measurements performed by the two observers did not differ in the proximal and middle regions. A significant difference between the pre-operative and post-operative SFB compared to the untreated side was found in the proximal femur segment (p = 0.004). Use of a cementless stem in THA induced chronological changes in SFB of the proximal femur, after a minimum timespan of 3 years.

Asfotase alfa has a limited effect in improving the bowed limbs in perinatal benign hypophosphatasia: A case report

Hypophosphatasia (HPP) is a rare skeletal dysplasia characterized by impaired bone mineralization, caused by loss-of-function mutations in the tissue-nonspecific alkaline phosphatase (TNSALP) gene. Enzyme replacement therapy (ERT) by administration of asfotase alfa was reported to improve the survival rate, bone mineralization, and short stature in the severe form of HPP. However, the effect of asfotase alfa in improving the skeletal phenotypes for the mild form of HPP has not been elucidated. We report a case with perinatal benign HPP who had compound heterozygous mutations of p.F327L and p.R30X in the TNSALP gene. No hypomineralization was seen in the radiographs from the neonatal period, but bowing of the femurs and ulnares bilaterally was persistent. ERT was administered during the age of 7.8 to 10.8 yr, although there was an interruption in the treatment for one year. The bowed femurs and ulnares were not improved by the treatment with asfotase alfa at the age of 10.8 yr. Bone mineral density of the lumbar spine was between –0.5 and –1.0 of the z-score, and the patient’s height was about –2.0 SD during the treatment. Asfotase alfa might have a limited effect in improving the bowed limbs in perinatal benign hypophosphatasia.

Comparison of 2 Oblique Fifth Metatarsal Osteotomies for the Management of a Bunionette

Background:

A bunionette is a painful prominence of the fifth metatarsal head. This study aimed to compare the clinical outcome of 2 corrective osteotomies, namely, the Mau-type and Ludloff-type osteotomies. We report results with regard to correction, healing, complications, and patient-reported outcomes.

Methods:

Thirty-two patients who underwent bunionette corrective surgery from March 2011 to May 2017 were included in the study. All patients had pre- and postoperative radiographs. The pre- and postoperative fourth-fifth intermetatarsal angles (IMAs) and postoperative fifth metatarsal bowing angle were measured. Radiographic union was assessed at 12 weeks. All patients completed the Self-Reported Foot and Ankle Score (SEFAS) questionnaire to assess clinical outcome. Thirty-two patients (43 feet) were available for follow-up and completed the SEFAS score. Twenty-two Mau-type and 21 Ludloff-type osteotomies were performed.

Results:

The mean pre- and postoperative IMA for Mau was 10.5 and 4.3 degrees, respectively, and for the Ludloff was 10.2 and 4 degrees, respectively, with no statistically significant difference between the 2 groups. The Mau caused more bowing with a mean of 9.8 degrees as compared to a mean of 3.5 degrees with the Ludloff. No patients in the Mau group reported clinical problems related to the increased bowing. All osteotomies united. The Mau cohort had a mean SEFAS score of 45 and the Ludloff cohort a mean of 46. No feet had fair or poor outcome scores.

Conclusion:

Patient satisfaction after bunionette correction with an oblique shaft rotational osteotomy was good. Orientation of the osteotomy did not affect outcomes. Postoperative bowing of the fifth metatarsal was greater with the Mau-type osteotomy. Postoperative fifth metatarsal bowing had no negative clinical effects. The trend in our unit has been a preference toward the Mau-type osteotomy as it is perceived to be more stable.

Level of Evidence:

Level III, retrospective comparative series.

Numerical Analysis of Bowing Phenomenon Due to Thermal Stresses in Marble Slabs

Bowing is a pathology known by the deformation experienced in some external covering systems in ornamental stones, especially in marble, and thermal action is one of the key factors that lead to this degradation. Previous studies presented remarkable contributions about the mechanical behavior of bowing but they were based on classical beam’s theory and improper assumptions might mislead the evaluation of internal stresses. This study proposes to evaluate internal stresses in bowing due to thermal loading considering the true deformed shape in continuum media. Finite displacement concepts are proposed to calculate stress-strain relationship and comparison with linear elastic theory is also addressed. Internal stresses not predictable in the Euler-Bernoulli beam were found in parametric analyses. Moreover, the numerical analysis accomplished in this paper indicates that transient heat flux should induce higher stresses than just considering higher gradients of temperature in steady flux which could explain the larger decohesion through width in bowing tests.

Quantitative Ultrasound and Tibial Dysplasia in Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder associated with unilateral anterolateral bowing with subsequent fracture and nonunion. In infancy, physiologic bowing of the lower leg can be confused with pathologic tibial dysplasia in NF1. Little is known about the bone physiology of the tibiae prior to fracture or predictors of fracture. The aim of this study was to characterize bone quality of bowed tibiae prior to fracture in NF1 using quantitative ultrasound (QUS). Bone quality was assessed on both tibiae (the non-bowed and bowed tibiae) using QUS to measure speed of sound (SOS) at the mid-shaft in 23 individuals with NF1. SOS (m/s) was determined and Z-scores generated using cross-sectional reference data of the same sex and age. The mean difference in SOS Z-scores when comparing the bowed tibia vs the individual's contralateral unaffected tibia was statistically significant with lower mean Z-scores in the bowed tibia (p = 0.001). Radiographs of all individuals with a clinical diagnosis of anterolateral bowing were reviewed, and in 2 individuals the radiographs showed minimal bowing with absence of characteristic cortical thickening and medullary canal narrowing in NF1-related tibial dysplasia, suggesting physiologic bowing. In both individuals, the Z-scores of the bowed leg were not lower than the unaffected leg supporting the suggestion of physiologic bowing rather than pathologic tibial dysplasia. These data show that dysplastic tibiae in NF1 prior to fracture and nonunion have abnormal bone quality with significant decreases in SOS even though radiographically the tibiae show a thickened cortex. These data also suggest that QUS can help distinguish dysplastic bowing vs physiologic bowing in infancy in NF1. QUS is an effective quantitative outcome measure for trials aimed at improving tibial bowing to prevent fracture, and it is a potential aid in diagnosis and clinical management in NF1.

Infantile blount disease: a case report

Blount disease is an acquired growth disorder of the medial aspect of the proximal tibial physis, epiphysis and metaphysis. Infantile Blount disease present with bowing and length discrepancy in the lower limbs. The deformed medial tibial metaphysis represent as nontender bony protuberance can be palpated along the medial aspect of the proximal tibia. Here, we present an 18-month-old boy presented with the complaints of bilateral bowing of lower limb with normal biochemical investigation and radiological survey revealed Blount disease.