Nicole Pouliart

Atlas of functional shoulder anatomy

Scapulothoracic Joint.- Acromioclavicular Joint and Scapular Ligaments.- Glenohumeral Joint (Muscle-Tendon).- Glenohumeral Capsule.- Neuromuscular Control and Proprioception of the Shoulder.

A cadaveric study of the structural anatomy of the sternoclavicular joint.

Pathologies of the sternoclavicular (SC) joint are infrequent and effective management is often hindered by a limited understanding of the anatomy. In this study, we did macroscopic evaluations of the ligaments, the intra‐articular disc, and the articulating surfaces of 25 SC joints. After removal of the joint capsule, the articulating surfaces of the sternal end of clavicle and the sternum were evaluated and the intra‐articular disc was macroscopically examined. The anterior SC ligament covered the intra‐articular disc, which divided the joint into a clavicular and a sternal part. A thin capsule, relatively lateral and medial from the anterior SC ligament, covered the two intra‐articular parts. This means that the anterior SC ligament can be used as a landmark to enter into clavicular or sternal part of the SC joint. Posteriorly, there was a thick capsule without soft‐spot or clear posterior SC ligament. Only the antero‐inferior surface of the sternal end of every clavicle was covered by cartilage. Of the intra‐articular discs 56% were incomplete. All of these incomplete discs displayed a central hole with signs of degeneration and fraying. This was associated with increased cartilage degeneration at the clavicular side. By experimental design (past and present), it would seem reasonable to assume that the incomplete types are caused by degeneration and are not developmental. Clin. Anat. 25:903–910, 2012.

Determination of a reference system for the three-dimensional study of the glenohumeral relationship

ObjectiveKnowledge of the normal and pathological three-dimensional glenohumeral relationship is imperative when planning and performing a total shoulder arthroplasty. There is, however, no consensus on which references should be used when studying this relationship. The purpose of the present study was to define the most suitable glenoid plane with normally distributed parameters, narrowest variability, and best reproducibility.Materials and methodsThree-dimensional reconstruction CT scans were performed on 152 healthy shoulders. Four glenoid planes, each determined by three surgically accessible bony reference points, were determined. Two planes were triangular, with the same base defined by the most anterior and posterior point of the glenoid. The most inferior and the most superior point of the glenoid, respectively, define the top of Saller’s inferior plane and the Saller’s superior plane. The two other planes are formed by best-fitting circles. The circular max plane is defined by the superior tubercle, and two points at the distal third of the glenoid. The circular inferior plane is defined by three points at the rim of the inferior quadrants of the glenoid.ResultsThe parameters of all four planes behave normally. The humeral center of rotation is identically positioned for both the circular max and circular inferior plane (X = 91.71°/X = 91.66° p = 0.907 and Y = 90.83°/Y = 91.7° p = 0.054, respectively) and different for the Saller’s inferior and Saller’s superior plane (p ≤ 0.001). The circular inferior plane has the lowest variability to the coronal scapular plane (p < 0.001).ConclusionsThis study provides arguments to use the circular inferior glenoid plane as preferred reference plane of the glenoid.

Assessment of the long head of the biceps tendon of the shoulder with 3T magnetic resonance arthrography and CT arthrography

We studied the assessment of proximal biceps tendon lesions including degeneration, tendon luxation, and partial and complete tendon tears with 3T MR arthrography and CT arthrography. Thirty-six patients who underwent both studies, as well as arthroscopy were included in the study. The images were randomized and blinded and independently reviewed by two musculoskeletal radiologists. The pooled sensitivity for lesion detection for CT arthrography was 31% and the specificity 95%. The pooled sensitivity for MR arthrography was 27% and the specificity 94%. There were no statistically significant differences between CT and MR. The interobserver agreement calculated with the kappa statistic was poor for CT and for MR. Both CT arthrography and MR arthrography perform poorly in the detection of biceps tendon pathology of the shoulder.

Arthroscopic glenohumeral folds and microscopic glenohumeral ligaments: The fasciculus obliquus is the missing link

This study tested the hypotheses that the folds in the inferior glenohumeral capsule appear at the borders and crossings of the underlying capsular ligaments and that embalming may result in misinterpretation of these folds as ligaments. The inferior capsular structures in 80 unembalmed cadaver shoulders were compared with 24 embalmed shoulders. During arthroscopy and dissection, an anteroinferior fold was more prominently seen in internal rotation and was almost obliterated in external rotation. A posteroinferior fold appeared in external rotation and almost disappeared in internal rotation. During dissection, the anteroinferior fold developed at the border of the anterior band of the inferior glenohumeral ligament (ABIGHL) and where this ligament crossed with the fasciculus obliquus (FO). Several patterns of crossing of the ABIGHL and the FO were seen that determined the folding-unfolding mechanism of the anteroinferior fold and the appearance of possible synovial recesses. The axillary part of the IGHL is formed by the FO on the glenoid side and by the ABIGHL on the humeral side. The posteroinferior fold was determined by the posterior band of the IGHL. The folds in the embalmed specimens did not necessarily correspond with the underlying fibrous structure of the capsule. The folds and recesses observed during arthroscopy indicate the underlying capsular ligaments but are not the ligaments themselves. The IGHL complex is formed by its anterior and posterior bands and also by the FO. Both findings are important during shoulder instability procedures because the ligaments need to be restored to their appropriate anatomy and tension. Because the FO may also be involved, Bankart-type surgery may have to reach far inferiorly. Midsubstance capsular shift procedures also need to incorporate this ligament.

Locked patellar dislocation: a case report

IntroductionAcute patellar dislocation is a relatively common problem. The most common dislocation is laterally in the coronal plane. Sometimes spontaneous reduction occurs, but if not, closed reduction can easily be done. In this paper, we report a very uncommon type of locked dislocation which required an open reduction.Case presentationA 16-year-old girl of Hispanic origin sustained a sudden dislocation of the patella while she was dancing. Pre-operative computed tomography revealed a patellar dislocation with rotation around the vertical axis with the patella wedged on the side of the lateral condyle. Closed reduction failed. Open reduction was needed and the torn structures were repaired. At 1-year follow-up, she had a good functional outcome and reported no recurrence of dislocation.ConclusionThis case report shows that some patellar dislocations may be irreducible with the closed technique. Computed tomography is valuable in case of doubt. If an open reduction is needed, the medial ligamentous structures should be repaired.

Advanced imaging of the glenohumeral ligaments.

The glenohumeral ligaments (GHLs) are the most important passive stabilizers of the shoulder joint. Recognition of acute and chronic glenohumeral ligamentous lesions is very important in the preoperative work-up of shoulder instability and trauma. This article describes and depicts the normal anatomy of the GHLs and their appearance during arthroscopy and on MR and computed tomography arthrography (CTA). Pathologic findings of the superior, middle, and inferior GHLs are described and illustrated with MR and CTA and their corresponding intraoperative arthroscopic images. MR arthrography (MRA) is useful for direct visualization of all GHLs including most lesions of their intra-articular portion and associated capsulolabral pathologies. Sprains, midsubstance tears, avulsion, or fibrous infiltration of the GHL can be identified on MRA images using fast spin-echo sequences with and without fat saturation in the three planes. Although CTA is reputed to better depict associated bony and cartilage lesions, CTA allows only indirect evaluation of the GHLs by outlining their contour or showing contrast penetration. Normal variants may create pitfalls that one should be aware of. Signs of GHL pathology on imaging include: discontinuity, nonvisualization, changes in signal intensity (on MRA), contrast extravasation, contour irregularity, thickening, or waviness.

Arthroscopy of the sternoclavicular joint: an anatomic evaluation of structures at risk

IntroductionRecently, arthroscopy of the sternoclavicular joint (SCJ) has been described in clinical setting. The aim of this study is to examine the accessibility and safety of the SCJ by arthroscopy in a cadaveric model.Materials and methodsAn inferolateral and superomedial portal to the SCJ was created in 20 cadaveric specimens. After debridement, the specimens were dissected with a needle positioned in the portal tracts. The distance between the needles and bony landmarks, tendons and ligaments were measured. The integrity of the posterior capsule was evaluated macroscopically. In eight specimens, after anterior dissection, the needles were replaced by K-wires that perforated the posterior capsule to evaluate the distance to the neurovascular structures behind the SCJ.ResultsBoth portals were found to be safe while allowing good access to the joint. The superomedial portal went through the tendon of the sternocleidomastoideus muscle and the inferolateral portal through the pectoralis major muscle. The portals entered the capsule medial and lateral to the anterior sternoclavicular ligament. The posterior capsule was never perforated during debridement. The perforating K-wires, however, usually perforated either a major vein or artery, but were at a safe distance from the vagal nerve.ConclusionsIn this cadaver study, arthroscopy of the sternoclavicular joint could be used as a minimally invasive procedure allowing debridement of the joint without damaging the posterior capsule of the joint. If the capsule is inadvertently be breached, a major risk of neurovascular damage exists. We advise to have a backup of a cardiothoracic surgeon when performing this procedure.

Anterosuperior labral tear without biceps anchor involvement: A subtle isolated cause of a painful shoulder

PURPOSE The purposes of this study were to determine common clinical symptoms related to an anterosuperior labral tear without biceps anchor involvement and to establish the outcome of arthroscopic management of this injury. METHODS In our database of arthroscopic procedures we identified 23 patients with an isolated anterosuperior labral tear. The mean age at the time of surgery was 38.3 ± 6.8 years (range, 18 to 59 years). The preoperative clinical diagnosis varied, but an anterosuperior labral isolated lesion was not detected before surgery. The diagnosis of anterosuperior labral tear was made arthroscopically, and the lesion was fixed with a suture anchor technique, by use of 1 single bioabsorbable anchor. Patients were reviewed after a minimum of 2.5 years of follow-up. Clinical outcome was evaluated with the Rowe score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, and visual analog scale score. RESULTS History, clinical examination, and preoperative imaging usually failed to indicate the presence of an isolated anterosuperior labral tear as the cause of shoulder pain in our patients. Repair of the labral lesions yielded good to excellent results with normalization of the range of motion and a significant improvement in shoulder scores (Rowe, American Shoulder and Elbow Surgeons, Simple Shoulder Test, and visual analog scale). CONCLUSIONS Isolated tears of the anterosuperior labrum represent a subtle cause of shoulder pain and dysfunction. The lesion is very difficult to diagnose clinically. Arthroscopic repair is a reliable procedure providing a good outcome in terms of pain relief, patient satisfaction, and shoulder scores. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Consequences of a Perthes-Bankart lesion in twenty cadaver shoulders

This study investigated whether an anteroinferior capsulolabral lesion is sufficient to allow the humeral head to dislocate and whether a limited inferior approach for creating the lesions influenced the results compared with an all-arthroscopic approach. Four ligamentous zones of the glenohumeral capsule were sequentially detached from the glenoid neck and labrum in 20 cadaver shoulders through an inferior approach. Before and after each resection step, inferior stability was tested using a sulcus test and anterior stability using a drawer test and an apprehension maneuver. Dislocation was only possible when at least 3 zones were cut. This study confirmed that superior and posterior extension of the classic anteroinferior Perthes-Bankart lesion is necessary before the capsular restraint in external rotation and abduction is overcome and dislocation occurs. Lesions other than the Perthes-Bankart need to be investigated when recurrent dislocation is treated, because this anteroinferior injury is most probably not the sole factor responsible for the instability.