Restoration of elbow extension and construction of a "key grip" in people with tetraplegia. Comparative study of a surgical plan in one or two stages

AIM

We report the comparative results of functional upper extremity surgery plans in patients with tetraplegia, including restoration of elbow extension and construction of a key grip in a "one-stage" or "two-stage" operation.

MATERIALS AND METHODS

A series of 36 patients with tetraplegia, with a total of 45 operated upper limbs, was analyzed retrospectively with a mean follow-up of 23 months (13-39 months). We evaluated the analytical strength of elbow extension using the MRC (Medical Research Council) score, the strength of the key grip (kg/F) as well as the autonomy of the patients using functional scores; Lamb (/100) and QIF (Quadriplegia Index of Function) (/100).

RESULTS

Sixteen upper limbs were included in the "one-stage" group and 29 in the "two-stage" group. The groups were comparable preoperatively. Elbow extension strength was 3.6/5 in the one-stage group versus 3.7/5, p=0.74. Grip strength was 1.8kg/F in the one-stage group versus 1.3kg/F, p=0.22. Regarding the functional scores, there was no statistically significant difference between the two groups for the Lamb score (p=0.46) and the QIF (p=0.42). There was no statistically significant difference in terms of the frequency of complications for the elbow (p=0.49) and for the hand (p=0.17). The total duration of the one-stage surgery plan averaged 7.5 months compared to 24.7 months for the two-stage plan, p<0.01. The mean follow-up for the one-stage group was 21 months versus 24 months for the two-stage group.

CONCLUSION

The results of both plans are similar and indicate that the "one-stage" plan is a reliable option. This all-in-one surgical option reduces postoperative follow-up and dropout rates for patients during the plan timeframe.

LEVEL OF EVIDENCE

IV; retrospective clinical series.

Prospective study of 90 arthroscopic rotator cuff repairs for isolated distal supraspinatus tear, assessing the impact of cardiovascular risk factors on tendon healing

INTRODUCTION

Cardiovascular risk factors have been shown to be relevant to onset of rotator cuff tear, but their influence on healing remains to be determined.

OBJECTIVE

To assess the individual and cumulative impact of cardiovascular risk factors on tendon healing after arthroscopic rotator cuff repair.

MATERIAL AND METHOD

A single-center prospective study included 90 patients undergoing arthroscopic repair of isolated distal supraspinatus tendon tear. Only isolated full-thickness tears without anteroposterior extension, retraction (Patte stage ≤ 2) or fatty involution were included. Tendon healing was assessed on ultrasound according to the 5 types of the Sugaya classification. Clinical and functional assessment at 12 months used Constant score. Cardiovascular comorbidities were screened for in the preoperative anesthesiology consultation and control consultation: smoking, high blood pressure, dyslipidemia, diabetes, obesity, cardiovascular history, and obstructive sleep apnea syndrome.

RESULTS

Ninety patients with a mean age of 59.6±6.95 years were included for analysis. 77.7% of cuffs showed healing on ultrasound, without signs of retear (stage 1-3), 16.6% showed partial retear (stage 4) and 6.6% showed no healing, with tendon retraction (stage 5). Mean Constant score improved by 37.5 points (p=0.001), for a global score of 78 at 12 months. Multivariate analysis identified several significant cardiovascular factors for poor healing: active smoking (p=0.002), dyslipidemia (p=0.006), high blood pressure (p≤0.001) and obesity (p=0.02). Cumulative comorbidity was associated with poor tendon healing, with significant impact as of 2 cardiovascular risk factors. Constant score decreased significantly according to healing stage (p≤0.001).

CONCLUSION

The present study confirmed the involvement of cardiovascular risk factors in bone-tendon healing disorder, with significant impact as of 2 factors.

LEVEL OF EVIDENCE

IV; low-power prospective clinical series.

Perception of vowel-to-vowel transitions with different formant trajectories

In this paper, the perceptual effects of vowel-to-vowel transitions determined by different temporal variations of model parameters which specify the shapes of the vocal tract area function are investigated. It is shown that, (a) the method of deformation of the vocal tract area function between two targets can be perceptually important and (b) conversely, within certain limits, the time course of parameters from one state to another, and the precise synchronization of two parameters is not important for the correct identification of a vowel series. These characteristics are necessary but not sufficient to prove the existence of a phonetic gesture percept.

Perceptual discrimination of speech sounds in developmental dyslexia

Experiments previously reported in the literature suggest that people with dyslexia have a deficit in categorical perception. However, it is still unclear whether the deficit is specific to the perception of speech sounds or whether it more generally affects auditory function. In order to investigate the relationship between categorical perception and dyslexia, as well as the nature of this categorization deficit, speech specific or not, the discrimination responses of children who have dyslexia and those of average readers to sinewave analogues of speech sounds were compared. These analogues were presented in two different conditions, either as nonspeech whistles or as speech sounds. Results showed that children with dyslexia are less categorical than average readers in the speech condition, mainly because they are better at discriminating acoustic differences between stimuli belonging to the same category. In the nonspeech condition, discrimination was also better for children with dyslexia, but differences in categorical perception were less clear-cut. Further, the location of the categorical boundary on the stimulus continuum differed between speech and nonspeech conditions. As a whole, this study shows that categorical deficit in children with dyslexia results primarily from an increased perceptibility of within-category differences and that it has a speech-specific component. These findings may have profound implications for learning and re-education.

Modeling and perception of 'gesture reduction'

The phenomenon of vowel reduction is investigated by modeling 'gesture reduction' with the use of the Distinctive Region Model (DRM). First, a definition is proposed for the term gesture, i.e. an acoustically efficient command aimed at deforming, in the time domain, the area function of the vocal tract. Second, tests are reported on the perception of vowel-to-vowel transitions obtained with reduced gestures. These tests show that a dual representation of formant transitions is required to explain the reduction phenomenon: the trajectory in the F(1)-F(2) plane and the time course of the formant changes. The results also suggest that time-domain integration of the trajectories constitutes an integral part of the auditory processing of transitions. Perceptual results are also discussed in terms of the acoustic traces of DRM gestures.