Morphologic Alterations of the Sternoclavicular Joint following Ipsilateral Clavicle Fractures.

RATIONALE: To our knowledge, no study has investigated concomitant injuries of the sternoclavicular joint (SCJ) in acute clavicle fractures. The purpose of this study was to determine the effect of an ipsilateral clavicle fracture on the SCJ in a systematic computer tomography (CT) morphologic evaluation. METHODS: CT scans in the axial and coronal plane of 45 consecutive patients with clavicle fractures were retrospectively analyzed. The scans were assessed regarding anatomic congruence of bilateral SCJs-joint space width (JSW); the position of bilateral medial clavicles (PC); and the non-fusion of epiphyses, arthritis, calcifications, and intra-articular gas. RESULTS: The mean SCJ JSW was significantly different in the coronal (cJSW; 8.70 mm ± 2.61 mm in affected vs. 7.63 mm ± 2.58 mm in non-affected side; p = 0.001) and axial plane (aJSW; 9.40 mm ± 2.76 mm in affected vs. 9.02 ± 2.99 in non-affected SCJs; p = 0.044). The position of the medial clavicle showed a significant difference in the coronal plane (cPC; 14.31 mm ± 3.66 mm in the affected vs. 13.49 ± 3.34 in the non-affected side; p = 0.011), indicating a superior shift. CONCLUSION: Acute clavicle fractures may be associated with an enlargement of the ipsilateral SCJ space width and a superior shift of the proximal clavicle. Both morphologic alterations could indicate concomitant injuries of the SCJ as well as a potential increase in the risk of SCJ instability.

Apprasial of the surface anatomy of the Thorax in an adolescent population.

Surface anatomy is considered a fundamental part of anatomy curricula and clinical practice. Recent studies have reappraised surface anatomy using CT, but the adolescent age group has yet to be appraised. Sixty adolescent thoracoabdominal CT scans (aged 12-18 years) were examined. The surface anatomy of the central veins, cardiac apex, diaphragmatic openings, and structures in relation to the sternal angle plane were analyzed. The results showed that the brachiocephalic vein (left and right) formed mostly posterior to the sternoclavicular joint. The superior vena cava formed close to the second costal cartilage, ±16.3 mm to the right of the midline. The apex of the heart was located in relation to the fifth intercostal space; ±78.6 mm to the left of the midline. The caval hiatus was in relation to T9 and T10; the esophageal hiatus was at T10; whereas the aortic hiatus was at T11. The sternal angle plane was in relation to the upper half of T5, which was also where the bifurcations of the trachea and pulmonary trunk were observed. The SVC/azygos vein junction and the concavity of the aortic arch were observed to be more than 10 mm superior to this plane. The results of this study further highlight the substantial variability of the surface anatomy between age groups. It also emphasizes the notion that surface anatomy is a dynamic variable and cannot be treated as a static observation. Clin. Anat. 32:762-769, 2019. © 2019 Wiley Periodicals, Inc.

The dominant nutrient foramen at the clavicular midshaft: an anatomical study.

BACKGROUND: The aim of the present study was to describe the prevalence and topography of the dominant nutrient foramen at the clavicle. METHODS: 317 macerated human clavicles (167 right and 150 left) were available for the study. After detecting the dominant nutrient foramen, the total distance from the sternal surface to the examined nutrient foramen was measured. A foramen index (FI) was used for further data processing. RESULTS: We detected a dominant foramen in 300/317 (94.64%) clavicles, which was located in the middle third in 287/300 (95.7%) clavicles. The average clavicular length was measured at 14.9 cm ± 1.0 cm (range 11.6-17.5 cm) with an average foraminal distance from the sternoclavicular joint surface of 7.9 cm ± 1.3 cm (range 0.9-12.6 cm) in total. The mean FI was 53.2% ± SD 7.4% (range 5.5-79.3%). CONCLUSION: The present study provides a topographic mapping of the foraminal area (46-60% of the total clavicular length). The findings help to assess clavicular fracture patterns, which pass through the foraminal area.

Surgical anatomy of the sternoclavicular joint: a qualitative and quantitative anatomical study.

BACKGROUND: The quantitative anatomical relationships of the main ligamentous, tendinous, and osseous structures of the sternoclavicular joint have not been widely investigated. The purpose of this study was to provide a quantitative description of the sternoclavicular joint in relation to relevant surgical landmarks. METHODS: We dissected eleven nonpaired, fresh-frozen cadaveric sternoclavicular joints from four men and seven women (mean age at death, fifty-three years; range, thirty-three to sixty-four years) and measured the ligaments, musculature, and osseous landmarks with use of a three-dimensional coordinate-measuring device. RESULTS: The clavicular pectoralis ridge, located at the 9:30 clock-face position on a right clavicle, served as a reliable osseous landmark for reference to the soft-tissue attachments around the sternoclavicular joint. The costoclavicular ligament was the largest ligament of the sternoclavicular joint, with 80% greater footprint area than that of the posterior sternoclavicular ligament. Articular cartilage covered 67% of the medial end of the clavicle and was located anteroinferiorly. The sternohyoid muscle inserted directly over the posterior sternoclavicular joint and the medial end of the clavicle, whereas the sternothyroid muscle inserted 9.5 mm inferior to the posterior-superior articular margin of the manubrium and coursed 19.8 mm laterally along the first rib. An avascular plane that can serve as a "safe zone" for posterior dissection was observed in each specimen, posterior to the sternoclavicular joint and anterior to the sternohyoid and sternothyroid muscles. CONCLUSIONS: The clavicular pectoralis ridge can be used as an intraoperative guide for clavicle orientation and tunnel placement in sternoclavicular ligament reconstruction. Sternoclavicular joint resection arthroplasty should avoid injuring the costoclavicular ligament, which is the largest sternoclavicular joint ligament. Resection of only the anteroinferior aspect of the medial end of the clavicle may provide adequate decompression while preserving the stability of the clavicle. The location of the sternohyoid and sternothyroid musculotendinous insertions appear to provide a "safe zone" for posterior clavicle and manubrial dissection.

Does patient sex affect the anatomic relationships between the sternoclavicular joint and posterior vascular structures?

BACKGROUND: Despite increased concern for injury during surgical reconstruction of the sternoclavicular joint, to our knowledge there are few studies detailing the vascular relationships adjacent to the joint. QUESTIONS/PURPOSES: We investigated sex differences in the following relationships for sternoclavicular joint reconstruction: (1) safe distance from the posterior surface of the medial clavicle's medial and lateral segments to the major vessels, (2) length of the first costal cartilage and safe distance from the first rib to the internal mammary artery, (3) minimum distance medial to the sternoclavicular joint for optimal hole placement, and (4) safe distance from the manubrium to the great vessels. METHODS: Fifty normal postcontrast CT scans of the chest were reviewed. Means, standard deviations, and 95% CI were calculated for each aforementioned measurement. A t-test was used to determine if a sex difference exists (p≤0.05). RESULTS: At the medial end of the clavicle, the safe distance from the medial segment (first 10 mm) to the major vessels was greater in males than in females (3.5 mm versus 2.4 mm, respectively; 95% CI, 3 mm-4 mm versus 1.7 mm-3 mm, respectively; p=0.014). For the lateral segment (next 10 mm), the distance also was safer in males than in females (3.3 mm versus 1.7 mm, respectively; 95% CI, 2.7 mm-4 mm versus 1.1 mm-2.3 mm, respectively; p<0.001). The mean length of the first costal cartilage also was greater in males (35.8 mm versus 30.1 mm, respectively; 95% CI, 33.8 mm-37.8 mm versus 28.5 mm-31.9 mm, respectively; p<0.001); the distance from the first costochondral joint to the internal mammary artery was safer in males than in females (19.1 mm versus 15.4 mm, respectively; 95% CI, 16.5 mm-21.8 mm versus 13 mm-17.9 mm, respectively; p=0.05). The minimum distance to avoid inadvertent penetration of the sternoclavicular joint was greater in males than in females (16 mm versus 12.3 mm, respectively; 95% CI, 14.6 mm-17.5 mm versus 11 mm-13.6 mm, respectively; p<0.001). The distance to vessels after penetration of the manubrium was not different between males and females (5.6 mm versus 3.9, respectively; 95% CI, 4.4 mm-6.8 mm versus 2.6 mm-5.2 mm, respectively; p=0.06). CONCLUSIONS: This study makes apparent the intimate relationships between vessels and the musculoskeletal structures associated with sternoclavicular reconstruction. Based on our findings, we recommend considering the sex of the patient, using caution when drilling, and protecting essential structures posterior to the joint.

Relationship of the Medial Clavicular Head to the Manubrium in Normal and Symptomatic Degenerated Sternoclavicular Joints.

BACKGROUND: Clavicular prominence is common in patients with symptomatic degenerative sternoclavicular arthritis. It is unclear if this is caused by enlargement or subluxation of the clavicle. The aim of this report is to describe a reproducible measurement technique to evaluate the relationship of the medial clavicular head to the manubrium. METHODS: One hundred normal sternoclavicular joints, twenty-five sternoclavicular joints with symptomatic degenerative arthritis, and twenty-five non-symptomatic sternoclavicular joints on the contralateral side were studied with three-dimensional (3D) reconstruction with use of computer modeling. The greatest width (anterior-posterior distance) and height (superior-inferior distance) of the clavicle in the sagittal plane were measured, and the positions of the anterior and superior borders of the medial clavicle and their distances to the frontal and axial planes, respectively, were evaluated. The ratio of the anterior-posterior distance to the anterior-frontal plane distance was measured to evaluate the anterior-posterior position of the clavicle and the ratio of the superior-inferior distance to the superior-axial plane distance was measured to evaluate its superoinferior position. If the ratio was not in the 95% normal range, the clavicle was defined as subluxated. The reproducibility of this technique was evaluated on the basis of the interobserver and intraobserver reliability. RESULTS: This technique showed good interobserver and intraobserver reliability. The mean anterior-posterior and superior-inferior distances were significantly larger in association with symptomatic sternoclavicular arthritis than in the normal sternoclavicular joints (p < 0001). The clavicle was subluxated anteriorly in twenty-two of the twenty-five cases of symptomatic sternoclavicular arthritis, but it was not subluxated superiorly. CONCLUSIONS: The medial clavicular head in patients with degenerative sternoclavicular arthritis is significantly larger than it is in the normal population, and it is usually subluxated anteriorly.

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

INTRODUCTION: Recently, 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 METHODS: An 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. RESULTS: Both 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. CONCLUSIONS: In 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.

Pitfalls in MR morphology of the sterno-costo-clavicular region using whole-body MRI.

AIM: To analyse the imaging findings at the sterno-costo-clavicular (SCC) joint region using whole-body (WB) magnetic resonance imaging (MRI) in healthy individuals to minimize misinterpretation as changes due to spondyloarthritis (SpA). MATERIALS AND METHODS: As part of a cross-sectional study of 122 SpA patients, 75 healthy individuals (42/33 males/females; median age 30.3 years; range 17.7-63.8 years) were scanned using sagittal and coronal WB short tau inversion recovery (STIR) and T1-weighted MRI sequences. The SCC region was analysed independently by seven readers for bone marrow oedema (BMO), erosions, subchondral fat signal intensity (FSI), and joint fluid accumulation. RESULTS: SCC changes simulating inflammation were reported by four or more of the seven readers in 15 (20%) healthy individuals (12 male/three female; median age 32.1 years; range 20.2-48 years). Thirteen individuals (17%) had changes at the manubriosternal joint (MSJ); five had BMO, one BMO + erosion, four erosion, two erosion + FSI, and one FSI only. Changes at the sternoclavicular joint occurred in three individuals (4%) encompassing erosion, erosion + FSI + BMO, and joint fluid accumulation, respectively. One patient had both MSJ and sternoclavicular joint changes. CONCLUSIONS: Findings mimicking inflammatory changes occurred in healthy individuals, particularly in the MSJ. Awareness of this is important in recognition of SCC inflammation in SpA.

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.

Under-recognized soft-tissue structures inferior and lateral to the head of the clavicle: Anatomy with computed tomography correlation.

This study was undertaken to provide an anatomical explanation for two soft-tissue structures anecdotally found on axial computed tomography (CT) scan, which are inferior (SI) and lateral (SL) to the head of the clavicle and adjacent to the sternoclavicular joint (SCJ). Three sets of cryosection images were reviewed to identify the anatomical structures corresponding to SI and SL. To demonstrate that SI and/or SL communicate with the SCJ cavity in the living, 312 consecutive chest CT scans were assessed for coexistence of SCJ and SI/SL air. To prove that under-recognition of SI and SL is due to the use of thick-section CT scan, another 50 consecutive chest CT scans were evaluated: visibility of SI and SL, and continuity between them on thick (5 mm)-section images were compared with those on thin (0.75 mm)-section images. The anterior portions of SI and SL were extensions from the SCJ cavity in the cryosection images, with the articular cartilage and disc occupying variable volumes of SI. The posterior portions of the SI and SL corresponded to the thyroid strap muscles. Air was present in 1 SI, 6 SLs, and 10 SCJs. Four of five patients with SI or SL air had coexisting SCJ air. Thick sections provided significantly poor visibility of SI and SL and continuity compared with thin-section images. SI and SL are constant shadows on thin-section CT scan, and their anterior and posterior portions represent extensions of the SCJ cavity and the strap muscles, respectively. The use of thick sections may be responsible for the under-recognition of SI and SL on CT scan.

Biomechanics and treatment of acromioclavicular and sternoclavicular joint injuries.

Acromioclavicular (AC) joint injuries are more common than sternoclavicular (SC) joint injuries. There is a spectrum of AC joint traumatic injuries that ranges from a ligament sprain to a complete dislocation. The majority of AC joint injuries are successfully treated non-operatively with a period of sling immobilisation followed by progressive physical therapy and shoulder range of motion exercises. In patients who have symptomatic AC joint injuries that are recalcitrant to non-operative treatment there exists a variety of surgical treatment options to reconstruct and stabilise the joint. The SC joint, like the AC joint, can suffer a spectrum of ligamentous injuries; however, when it comes to dislocation it can only dislocate anteriorly or posteriorly. Anterior dislocations are often successfully treated with closed reduction. Posterior dislocations have significant clinical implications because of the proximity of surrounding vessels and nerves. Any attempt at reduction of a posterior dislocation requires the presence of a cardiothoracic surgeon. The majority of AC and SC joint injuries typically result in ligamentous sprain and heal uneventfully with a period of immobilisation. If, however, patients remain symptomatic after non-operative treatment or have a dislocated joint, there are reduction manoeuvres and surgical techniques that allow joint stabilisation.

Safe drilling angles and depths for plate-screw fixation of the clavicle: avoidance of inadvertent iatrogenic subclavian neurovascular bundle injury.

BACKGROUND: Plate fixation is frequently used to repair clavicle fractures, but over drilling can cause subclavian neurovascular bundle damage. The aims of this study were to investigate the anatomic relationship between the clavicle and subclavian neurovascular bundle and to determine safe drilling angles and depths. METHODS: Twenty-six healthy subjects underwent magnetic resonance imaging. Coronal and sagittal images of the periclavicular region including the whole clavicle and nearby vital anatomic structures were obtained. The clavicle was divided into three sections: section I: between the sternoclavicular joint and point N (where the subclavian neurovascular bundle coursed below the midaxial level of the clavicle); section II: from N to the projection point of the coracoid process to the clavicle (CP'); and section III: from CP' to the acromioclavicular joint. Dangerous drilling depths and angles were determined for each section. RESULTS: In section I, the safe drilling angle was >59.7 degrees cephalad and >95.3 degrees caudad, while safe drilling depth was <17.0 +/- 2.4 mm. Corresponding values in section II were <1.2 degrees caudad and >142.4 degrees caudad. Safe drilling depth was no more than 36.2 mm +/- 12.4 mm. Depth and direction limitations were not assessed for section III, because the neurovascular bundle coursed well below the level of the coracoid process. CONCLUSIONS: We have used magnetic resonance imaging to determine safe drilling directions and depth for plate-screw fixation of the clavicle. On confirmation, these findings could be used in the clinical setting to reduce the risk of inadvertent iatrogenic subclavian neurovascular bundle injury during surgical clavicle fracture repair.

The costoclavicular ligament revisited: a functional and anatomical study.

INTRODUCTION: The sternoclavicular joint is of clinical importance. However, there is scant information in the literature regarding one ligament of this area, the costoclavicular ligament (CCL). MATERIAL AND METHODS: In order to further elucidate this structure, 10 adult formalin-fixed cadavers (17 sides) underwent dissection of the CCL. Once the CCL was identified, measurements were made of its dimensions and observations made of its anatomy. Next, ranges of motion were performed of the upper extremity and the CCL observed for tension or laxity. RESULTS: Of the 17 sternoclavicular regions examined 16 (94%) were found to possess a CCL. The average medial and lateral lengths, width and thickness were 1, 2, 1.2, 0.340 cm, respectively. The width of the CCL was statistically smaller in women that in men. The majority of ligaments were single structures traveling from the inferior surface of the medial clavicle just lateral and sometimes-fused (12.5%) to the lateral edge of the sternoclavicular joint. These fibers then terminated on the medial end of the first rib and first costal cartilage (75%) or exclusively onto the first costal cartilage (25%). Most ligaments were single and not composed of two parts. Arm abduction resulted in tautness of the ligament and increased as the degree of abduction increased. Internal rotation of the arm translated into medial shift of the clavicle, raising the clavicle away from the first rib creating tension on the CCL. Moderate degrees of external rotation were required before the CCL became taut and even began to pull the first rib laterally. Small amounts of protraction and retraction of the scapula both put the CCL under tension. CONCLUSIONS: The CCL is a constant structure found just lateral to the sternoclavicular joint. This ligament was a single band in the majority of our specimens and limited most ranges of motion of the proximal upper limb thus stabilizing the sternoclavicular region.

Variations in normal sternoclavicular joints; a retrospective study to quantify SCJ asymmetry.

OBJECTIVE: A wide degree of normal anatomical variation can occur at the sternoclavicular joint (SCJ). On occasion, this has led to concern for a pathological process, potentially resulting in a costly work-up, unnecessary patient worry and invasive diagnostic procedures such as biopsy. The purpose of this study was to determine the normal range of anatomical variation at sternoclavicular joints. MATERIALS AND METHODS: One hundred four consecutive patients with chest CT done at our institution were selected. Patients with clear SCJ pathology, chest wall abnormality, CT slice thickness greater than 5 mm and sternotomy wires, were excluded. Chart review was done and showed no SCJ symptoms/signs. We measured the SCJ space, maximum clavicular head diameter within the joint and the distance from manubrium to the anterior margin of the clavicular head. RESULTS: Left and right SCJ space ranged from 0.2 to 1.37 cm. The difference (delta or asymmetry) between left SCJ space and right SCJ space ranged from 0 (symmetrical) to 0.57 cm in 104 cases. Left and right clavicular head diameter ranged from 1.2 to 3.7 cm with left/right asymmetry (delta) ranging from 0 (symmetrical) to 1 cm. Manubrium to anterior margin of clavicular head ranged from 0.1 to 2.13 cm with delta ranging from 0 to 0.8 cm. Thirty-three patients demonstrated gas in the joint, five had poor articulation and four had calcification in the joint. CONCLUSION: Greater than 10% of patients show substantial asymmetry in the sternoclavicular joints, which may be misinterpreted as pathological. Gas in the joint is a common phenomenon therefore should not be an indication for further work-up in asymptomatic patients and likely excludes the presence of effusion.

Macroscopic and histological observations on the human sternoclavicular joint disc.

To know the detailed morphology of the human sternoclavicular joint and its articular disc is essential to understanding the movement of this joint and the functional role of the disc. In the present study, 51 articular discs of the sternoclavicular joint of 29 Japanese cadavers were macroscopically examined and then embedded in paraffin to make a complete series of coronal sections for light microscopic observation. We classified the articular discs into three types, discoid, ring, and meniscoid. The discoid-type disc was flattened and round in shape, whereas the other two types had partial defects in the centers (ring type) or in the periphery (meniscoid type). We found the bony process that protruded from the sternal end of the clavicle and fitted into the defect part of the ring- or meniscoid-type discs. The mean values of this bony process of the clavicle adjacent to the articular disc were 2.1, 4.7, and 6.0 mm, respectively, in the three types of articular disc. The movement between the articular disc and the clavicle may be limited, because the articular disc was directly attached to the clavicle on its medial region. The present histological observation demonstrated that the sternal side of the disc was composed of fibrocartilage and dense connective tissue. The clavicular side of the disc was composed of only fibrocartilage. The clavicular side of the articular disc of the sternoclavicular joint has the function of resisting the compressive load to the clavicular surface.

Disorders of the sternoclavicular joint.

The sternoclavicular joint is vulnerable to the same disease processes as other synovial joints, the most common of which are instability from injury, osteoarthritis, infection and rheumatoid disease. Patients may also present with other conditions, which are unique to the joint, or are manifestations of a systemic disease process. The surgeon should be aware of these possibilities when assessing a patient with a painful, swollen sternoclavicular joint.

Bilaterally existing sternoclavicularis anticus muscles.

A 92-year-old Japanese woman was found to have the sternoclavicularis anticus muscles existing bilaterally during the course of educational dissection at Nagoya City University Medical School. It was confirmed that these muscles received the nerve supply from small branches of the lateral pectoral nerves from the brachial plexus. Herein is documented the precise gross anatomical findings with some morphometric measurements. Moreover, the morphology of this muscle is discussed in relation to previously described variations of the pectoral sheet of muscles.

Surgical and clinical anatomy of the interclavicular ligament.

Dislocation of the sternoclavicular joint can be associated with life-threatening complications; therefore, a thorough knowledge of the ligaments contributing to sternoclavicular joint stability is essential for the clinician dealing with this anatomical area. The aim of our study was to examine the anatomy of the interclavicular ligament. We examined 50 human cadavers. The interclavicular ligament was identified in 90% of the specimens. The interclavicular ligament was located at the base of the sternal notch in 50% of the cases and connected the superior portions of the capsule of the sternoclavicular joints of each side. The interclavicular ligament connected with the posterior superior aspect of each medial end of the clavicle and with the fibers of the posterior and anterior interclavicular ligaments forming a continuous ligamentous layer. The mean length of this ligament was 2.1 cm, the mean width was 0.72 cm and the mean thickness was 0.36 cm. With the elevation of the shoulder joint and the abduction of the humerus, the interclavicular ligament remained lax. With the depression of the shoulder joint and the adduction of the humerus, this ligament became fully taut. As a result, the interclavicular ligament prevented the upward displacement of the clavicle during forceful depression of the humerus and the shoulder. The tensile force necessary for failure was >53.7 N/cm(2) in all the specimens. These data may be useful to surgeons for instituting techniques for surgical procedures that reconstruct the sternoclavicular joint. Moreover, a future study aimed at evaluating the long-term consequences of surgical transection of this ligament may be in order.