Pr BRONSARD Nicolas

Spino-femoral muscles affect sagittal alignment and compensatory recruitment: a new look into soft tissues in adult spinal deformity

Hongda Bao, Bertrand Moal, Shaleen Vira, Nicolas Bronsard, Celia Amabile, Thomas Errico, Frank Schwab, Wafa Skalli, Jean Dubousset, Virginie Lafage

https://pubmed.ncbi.nlm.nih.gov/32529524/

Abstract

Objective: To quantify muscle characteristics (volumes and fat infiltration) and identify their relationship to sagittal malalignment and compensatory mechanism recruitment.

Methods: Female adult spinal deformity patients underwent T1-weighted MRI with a 2-point Dixon protocol from the proximal tibia up to the T12 vertebra. 3D reconstructions of 17 muscles, including extensors and flexors of spine, hip and knee, were obtained. Muscle volume standardized by bone volume and percentage of fat infiltration (Pfat) were calculated. Correlations and regressions were performed.

Results: A total of 22 patients were included. Significant correlations were observed between sagittal alignment and muscle parameters. Fat infiltration of the hip and knee flexors and extensors correlated with larger C7-S1 SVA. Smaller spinal flexor/extensor volumes correlated with greater PI-LL mismatch (r = – 0.45 and – 0.51). Linear regression identified volume of biceps femoris as only predictor for PT (R2 = 0.34, p = 0.005) and Pfat of gluteus minimus as only predictor for SVA (R2 = 0.45, p = 0.001). Sagittally malaligned patients with larger PT (26.8° vs. 17.2°) had significantly smaller volume and larger Pfat of gluteus medius, gluteus minimus and biceps femoris, but similar values for gluteus maximus, the hip extensor.

Conclusion: This study is the first to quantify the relationship between degeneration of spino-femoral muscles and sagittal malalignment. This pathoanatomical study identifies the close relationship between gluteal, hamstring muscles and PT, SVA, which deepens our understanding of the underlying etiology that contributes to adult spinal deformity.

Keywords: Adult spinal deformity; Compensatory recruitment; Sagittal malalignment; Spino-femoral muscles.

Is it possible to give a single definition of the rectosigmoid junction?

Damien Massalou, David Moszkowicz, Daniela Mariage, Patrick Baqué, Olivier Camuzard, Nicolas Bronsard

https://pubmed.ncbi.nlm.nih.gov/29218384/

Abstract

Aim: The rectosigmoid junction is the limit separating the sigmoid colon and rectum. This transition zone has different definitions. We want to highlight different landmarks of the rectosigmoid junction (RSJ), to help the clinicians to adopt a consensual definition.

Method: We reviewed anatomical, endoscopic, physiological and surgical points of view concerning the rectosigmoid junction (RSJ).

Results: The rectosigmoid junction has a different definition depending on who is studying it. Nevertheless, it is a high pressure location, a place connecting different muscles organizations, neurological systems or vascular anastomosis. The clear pathophysiology of the RSJ is not yet determined with certainty, but its resection is essential for the therapeutic care of patients and also for the improvement of surgical skills. From a surgical point of view, anatomical landmarks has to be chosen: easily reproducible and identifiable. The disappearance of taenia coli (belonging to the colon) and the peritoneal reflection (recto-genital pouch), located below the upper rectum, seem the most reliable. The level of rectal section must, in any case, be below the promontory.

Conclusion: There is not a single definition, but rather several definitions of the RSJ. Each one of them reflects one appearance of this region: embryological and anatomical evolution or clinical entity. From a surgical point of view, the criterion which seems to be the most reliable is the disappearance of taenia coli and the peritoneal reflection (recto-genital pouch).

Keywords: Anatomy; Lymph node; Rectosigmoid junction; Rectum.

Estimation of spinopelvic muscles’ volumes in young asymptomatic subjects: a quantitative analysis

Celia Amabile, Bertrand Moal, Oussama Arous Chtara, Helene Pillet, Jose G Raya, Antoine Iannessi, Wafa Skalli, Virginie Lafage, Nicolas Bronsard

https://pubmed.ncbi.nlm.nih.gov/27637762/

Abstract

Purpose: Muscles have been proved to be a major component in postural regulation during pathological evolution or aging. Particularly, spinopelvic muscles are recruited for compensatory mechanisms such as pelvic retroversion, or knee flexion. Change in muscles’ volume could, therefore, be a marker of greater postural degradation. Yet, it is difficult to interpret spinopelvic muscular degradation as there are few reported values for young asymptomatic adults to compare to. The objective was to provide such reference values on spinopelvic muscles. A model predicting the muscular volume from reduced set of MRI segmented images was investigated.

Methods: A total of 23 asymptomatic subjects younger than 24 years old underwent an MRI acquisition from T12 to the knee. Spinopelvic muscles were segmented to obtain an accurate 3D reconstruction, allowing precise computation of muscle’s volume. A model computing the volume of muscular groups from less than six MRI segmented slices was investigated.

Results: Baseline values have been reported in tables. For all muscles, invariance was found for the shape factor [ratio of volume over (area times length): SD < 0.04] and volume ratio over total volume (SD < 1.2 %). A model computing the muscular volume from a combination of two to five slices has been evaluated. The five-slices model prediction error (in % of the real volume from 3D reconstruction) ranged from 6 % (knee flexors and extensors and spine flexors) to 11 % (spine extensors).

Conclusion: Spinopelvic muscles’ values for a reference population have been reported. A new model predicting the muscles’ volumes from a reduced set of MRI slices is proposed. While this model still needs to be validated on other populations, the current study appears promising for clinical use to determine, quantitatively, the muscular degradation.

Keywords: Asymptomatic subjects; MRI; Muscles; Volume; Young.

Inferior Cubital Artery Perforator Flap for Soft-Tissue Coverage of the Elbow: Anatomical Study and Clinical Application

Olivier Camuzard, Rémi Foissac, Cyril Clerico, Jonathan Fernandez, Thierry Balaguer, Tarik Ihrai, Fernand de Peretti, Patrick Baqué, Pascal Boileau, Charalambos Georgiou, Nicolas Bronsard

https://pubmed.ncbi.nlm.nih.gov/26984913/

Abstract

Background: Soft-tissue defects surrounding the elbow can be a challenging problem for the orthopaedic surgeon. Reliable reconstruction with use of muscular flaps or even perforator flaps derived from the surrounding vessels has been described. The inferior cubital artery (ICA) is an indirect septocutaneous perforator branch that most frequently arises from the lateral side of the radial artery. The purposes of the present study were to characterize the capillary cutaneous perforators of the ICA and to evaluate the potential of a local perforator flap procedure for soft-tissue coverage of the elbow.

Methods: Twenty fresh cadaveric forearms were dissected in order to describe the ICA anatomy, and in ten additional forearms the ICA was selectively injected with a red ink solution to detail the ICA vascular territory. For each artery, we recorded the site of origin, the diameter of the artery at its source, the course of the artery, and the number, type, and diameter of capillary cutaneous perforators.

Results: A total of seventy-eight ICA capillary perforators were analyzed from the twenty dissected forearms: forty-six were in-transit capillary perforators, nineteen were terminal capillary perforators, and thirteen were musculocutaneous capillary perforators. Of these seventy-eight perforators, sixteen (21%) had a caliber of <0.5 mm and sixty-two capillary perforators (79%) had a caliber of ≥0.5 mm. Ten ICAs were selectively injected, and the mean size of all stained skin areas was 30.9 ± 11.9 cm(2). A perforator pedicled flap was readily feasible for all dissections. We also describe the case of a patient with a medial soft-tissue defect of the elbow that was covered with a pedicled perforator flap based on an ICA. The patient had satisfactory healing at two months.

Conclusions: The ICA flap is a reliable and useful flap for elbow soft-tissue reconstruction.

Clinical relevance: The perforator flap procedure is a major advancement in reconstructive surgery. One potential application of the perforator flaps is the use of tissue adjacent to a defect as a perforator-based island flap. The use of this tissue allows for thinner flaps to be tailored for more accurate reconstruction. A flap that depends on a perforator branch of the radial artery called the inferior cubital artery seems to be an excellent solution for soft-tissue coverage of the elbow.

Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.

Facial artery perforator flap for reconstruction of perinasal defects: An anatomical study and clinical application

Olivier Camuzard, Rémi Foissac, Charalambos Georgiou, Lucas Andot, Florent Alcaraz, Patrick Baqué, Nicolas Bronsard, Gilles Poissonnet

https://pubmed.ncbi.nlm.nih.gov/26590853/

Abstract

Background: The concept of the facial artery perforator flap was developed for improved freedom during the reconstruction of perioral and perinasal defects. This flap enables tailor-made reconstruction and a shift from the traditional two-stage procedure to a one-stage technique. In this cadaveric study, the authors quantify the number, length, and diameter of facial artery perforators (FAPs) and present their clinical experience with the FAP flap.

Methods: The authors performed 20 dissections of facial arteries (FAs). All FAPs greater than 0.5 mm were dissected to study the number, length, and diameter of FAPs. In addition, the authors report a case series of 15 perinasal defect reconstruction procedures performed using facial artery-based perforator flap.

Results: A total of 125 FAPs were dissected. We identified a mean of six FAPs per hemiface (range five to eight). The average length of all FAPs was 17.6 ± 1.9 mm, and the mean diameter of the FAPs was 0.91 ± 0.2. Fifteen patients underwent a perinasal defect reconstruction using a FAP flap with good aesthetic and functional results.

Conclusions: The following study thus improves our understanding of FAP anatomy and clinical application and will enable the nasolabial fold to become the area where perinasal defect reconstruction using perforator flaps is performed.

Keywords: Cadaveric study; Facial artery; Facial artery perforator; Facial artery perforator flap; Facial reconstruction; Latex injection.

Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Volume and fat infiltration of spino-pelvic musculature in adults with spinal deformity

Bertrand Moal, Nicolas Bronsard, José G Raya, Jean Marc Vital, Frank Schwab, Wafa Skalli, Virginie Lafage

https://pubmed.ncbi.nlm.nih.gov/26495250/

Abstract

Aim: To investigate fat infiltration and volume of spino-pelvic muscles in adults spinal deformity (ASD) with magnetic resonance imaging (MRI) and 3D reconstructions.

Methods: Nineteen female ASD patients (mean age 60 ± 13) were included prospectively and consecutively and had T1-weighted Turbo Spin Echo sequence MRIs with Dixon method from the proximal tibia up to T12 vertebra. The Dixon method permitted to evaluate the proportion of fat inside each muscle (fat-water ratio). In order to investigate the accuracy of the Dixon method for estimating fat vs water, the same MRI acquisition was performed on phantoms of four vials composed of different proportion of fat vs water. With Muscl’X software, 3D reconstructions of 17 muscles or group of muscles were obtained identifying the muscle’s contour on a limited number of axial images [Deformation of parametric specific objects (DPSO) Method]. Musclar volume (Vmuscle), infiltrated fat volume (Vfat) and percentage of fat infiltration [Pfat, calculated as follow: Pfat = 100 × (Vfat/Vmuscle)] were characterized by extensor or flexor function respectively for the spine, hip and knee and theirs relationship with demographic data were investigated.

Results: Phantom acquisition demonstrated a non linear relation between Dixon fat-water ratio and the real fat-water ratio. In order to correct the Dixon fat-water ratio, the non linear relation was approximated with a polynomial function of degree three using the phantom acquisition. On average, Pfat was 13.3% ± 5.3%. Muscles from the spinal extensor group had a Pfat significantly greater than the other muscles groups, and the largest variability (Pfat = 31.9% ± 13.8%, P < 0.001). Muscles from the hip extensor group ranked 2(nd) in terms of Pfat (14% ± 8%), and were significantly greater than those of the knee extensor (P = 0.030). Muscles from the knee extensor group demonstrated the least Pfat (12% ± 8%). They were also the only group with a significant correlation between Vmuscle and Pfat (r = -0.741, P < 0.001), however this correlation was lacking in the other groups. No correlation was found between the Vmuscle total and age or body mass index. Except for the spine flexors, Pfat was correlated with age. Vmuscle and Vfat distributions demonstrated that muscular degeneration impacted the spinal extensors most.

Conclusion: Mechanisms of fat infiltration are not similar among the muscle groups. Degeneration impacted the spinal and hip extensors most, key muscles of the sagittal alignment.

Keywords: Adults with spinal deformity; Dixon method; Fat infiltration; Muscular degeneration; Muscular volume; Spino-pelvic musculature.