Guided versus freehand acromioplasty during rotator cuff repair. A randomized prospective study

INTRODUCTION

There is no consensus on how to perform acromioplasty, particularly regarding the level and extent of bone resection, which depend on scapular and humeral morphologies.

HYPOTHESIS

We aimed to determine whether computer-assisted acromioplasty planning helps surgeons remove impinging bone, reduce unnecessary resections, and improve short-term outcomes of rotator cuff tears (RCR).

PATIENTS AND METHODS

We randomized 64 patients undergoing RCR of full-thickness supraspinatus tears into two groups: 'guided acromioplasty' (GA) and 'freehand acromioplasty' (FA). The pre- and post-operative scapula models were reconstructed using computed-tomography scans to quantify impinging bone removal, unnecessary bone resections, and identify zones of acromial bone removal. All patients were evaluated preoperatively and at 6 months to assess their range of motion (ROM), functional scores and tendon integrity using ultrasound.

RESULTS

The two groups did not differ in demographics, clinical or morphologic characteristics. Compared to FA, GA tended to lower impinging bone removal (55±26% vs. 43±27%, p=0.087) and to increase unnecessary resection of the total bone removed (49±22% vs. 57±27%, p=0.248). GA resulted in significant anterior under-resection, while FA resulted in significant medial over-resection. Clinical outcomes and ROM improved significantly for all patients, except for internal rotation in the GA group. There were no other significant differences between the two groups, neither in terms of post-operative scores nor in terms of clinical net improvements, nor tendon repair integrity.

CONCLUSIONS

This computer-assisted planning for acromioplasty during RCR proved no benefits in terms of bone removal, tendon healing, or clinical outcomes. Nonetheless such planning tools could help less experienced surgeons improve the efficacy of acromioplasty.

LEVEL OF PROOF

I, Randomized controlled trial (Therapeutic study).

Acromioplasty during repair of rotator cuff tears removes only half of the impinging acromial bone

Background

To date, there is no consensus on when and how to perform acromioplasty during rotator cuff repair (RCR). We aimed to determine the volume of impinging bone removed during acromioplasty and whether it influences postoperative range of motion (ROM) and clinical scores after RCR.

Methods

Preoperative and postoperative computed tomography scans of 57 shoulders that underwent RCR were used to reconstruct scapula models to simulate volumes of impinging acromial bone preoperatively and then compare them to the volumes of bone resected postoperatively to calculate the proportions of desired (ideal) vs. unnecessary (excess) resections. All patients were evaluated preoperatively and at 6 months to assess ROM and functional scores.

Results

The volume of impinging bone identified was 3.5 ± 2.3 cm³, of which 1.6 ± 1.2 cm³ (50% ± 27%) was removed during acromioplasty. The volume of impinging bone identified was not correlated with preoperative critical shoulder angle (r = 0.025, P = .853), nor with glenoid inclination (r = -0.024, P = .857). The volume of bone removed was 3.7 ± 2.2 cm³, of which 2.1 ± 1.6 cm³ (53% ± 24%) were unnecessary resections. Multivariable analyses revealed that more extensive removal of impinging bone significantly improved internal rotation with the arm at 90° of abduction (beta, 27.5, P = .048) but did not affect other shoulder movements or clinical scores.

Conclusions

Acromioplasty removed only 50% of the estimated volume of impinging acromial bone. More extensive removal of impinging bone significantly improved internal rotation with the arm at 90° of abduction.

A Motion Capture Study to Measure the Feeling of Synchrony in Romantic Couples and in Professional Musicians

The feeling of synchrony is fundamental for most social activities and prosocial behaviors. However, little is known about the behavioral correlates of this feeling and its modulation by intergroup differences. We previously showed that the subjective feeling of synchrony in subjects involved in a mirror imitation task was modulated by objective behavioral measures, as well as contextual factors such as task difficulty and duration of the task performance. In the present study, we extended our methodology to investigate possible interindividual differences. We hypothesized that being in a romantic relationship or being a professional musician can modulate both implicit and explicit synchronization and the feeling of synchrony as well as the ability to detect synchrony from a third person perspective. Contrary to our hypothesis, we did not find significant differences between people in a romantic relationship and control subjects. However, we observed differences between musicians and control subjects. For the implicit synchrony (spontaneous synchronization during walking), the results revealed that musicians that had never met before spontaneously synchronized their movements earlier among themselves than control subjects, but not better than people sharing a romantic relationship. Moreover, in explicit behavioral synchronization tasks (mirror game), musicians reported earlier feeling of synchrony and had less speed errors than control subjects. This was in interaction with tasks difficulty as these differences appeared only in tasks with intermediate difficulty. Finally, when subjects had to judge synchrony from a third person perspective, musicians had a better performance to identify if they were present or not in the videos. Taken together, our results suggest that being a professional musician can play a role in the feeling of synchrony and its underlying mechanisms.

Embodied memory: unconscious smiling modulates emotional evaluation of episodic memories

Since Damasio introduced the somatic markers hypothesis in Damasio (1994), it has spread through the psychological community, where it is now commonly acknowledged that somatic states are a factor in producing the qualitative dimension of our experiences. Present actions are emotionally guided by those somatic states that were previously activated in similar experiences. In this model, somatic markers serve as a kind of embodied memory. Here, we test whether the manipulation of somatic markers can modulate the emotional evaluation of negative memories. Because facial feedback has been shown to be a powerful means of modifying emotional judgements, we used it to manipulate somatic markers. Participants first read a sad story in order to induce a negative emotional memory and then were asked to rate their emotions and memory about the text. Twenty-four hours later, the same participants were asked to assume a predetermined facial feedback (smiling) while reactivating their memory of the sad story. The participants were once again asked to fill in emotional and memory questionnaires about the text. Our results showed that participants who had smiled during memory reactivation later rated the text less negatively than control participants. However, the contraction of the zygomaticus muscles during memory reactivation did not have any impact on episodic memory scores. This suggests that manipulating somatic states modified emotional memory without affecting episodic memory. Thus, modulating memories through bodily states might pave the way to studying memory as an embodied function and help shape new kinds of psychotherapeutic interventions.

Increased postsynaptic density protein-95 expression in the frontal cortex of aged cognitively impaired rats

In the present work we studied synaptic protein concentrations in relation to behavioral performance. Long-Evans rats, aged 22-23 months, were classified for individual expression of place memory in the Morris water maze, in reference to young adults. Two main subgroups of aged rats were established: the Aged cognitively Unimpaired (AU) had search accuracy within the range (percent of time in training sector within mean ± 2 SEM) of young rats and the Aged cognitively Impaired (AI) rats had search accuracy below this range. Samples from the hippocampus and frontal cortex of all the AI, AU and young rats were analyzed for the expression of postsynaptic protein PSD-95 by Image J analysis of immunohistochemical data and by Western blots. PSD-95 expression was unchanged in the hippocampus, but, together with synaptophysin, was significantly increased in the frontal cortex of the AI rats. A significant correlation between individual accuracy (time spent in the training zone) and PSD-95 expression was observed in the aged group. No significant effect of age or PSD-95 expression was observed in the learning of a new position. All together, these data suggest that increased expression of PSD-95 in the frontal cortex of aged rats co-occurs with cognitive impairment that might be linked to functional alterations extending over frontal networks.

Transitory glutathione deficit during brain development induces cognitive impairment in juvenile and adult rats: Relevance to schizophrenia

Glutathione (GSH) metabolism dysfunction is one risk factor in schizophrenia. A transitory brain GSH deficit was induced in Wistar (WIS) and mutant (ODS; lacking ascorbic acid synthesis) rats using BSO (l-buthionine-(S,R)-sulfoximine) from post-natal days 5-16. When GSH was re-established to physiological levels, juvenile BSO-ODS rats were impaired in the water maze task. Long after treatment cessation, adult BSO-WIS/-ODS rats showed impaired place discrimination in the homing board with distributed visual or olfactory cues. Their accuracy was restored when a single cue marked the trained position. Similarly, more working memory errors were made by adult BSO-WIS in the radial maze when several olfactory cues were present. These results reveal that BSO rats did not suffer simple sensory impairment. They were selectively impaired in spatial memory when the task required the integration of multimodal or olfactory cues. These results, in part, resemble some of the reported olfactory discrimination and cognitive impairment in schizophrenia.