Clavicle Width Research Articles

Prevalence and Morphology of the Coracoclavicular Joint: An Osteological Study of 2,724 Subjects Using Univariable and Multivariable Logistic Regression Analyses.

Background: The coracoclavicular joint (CCJ) is an anomalous articulation between the surfaces of the inferior clavicle and superior coracoid and its etiology is controversial. Reportedly, symptomatic patients demonstrate significant functional limitations including shoulder abduction loss and potential for brachial plexus compression and impingement.Purpose: To determine the prevalence of CCJ across age, gender and ethnicity, and to identify clinically useful morphological characteristics.Methods: 2,724 subjects with intact clavicles and scapulae from the Hamann-Todd Osteological Collection were evaluated for the presence of CCJ. Logistic regression was used to determine the effect of age, height, gender, and race on prevalence of CCJ. 354 clavicles with CCJ were measured for size and location of the CCJ facet.Results: CCJ was observed in 9% of subjects. CCJ was more prevalent in African-Americans (12%) than Caucasian-Americans (6%) (p < 0.001) and more prevalent in females (11%) than males (8%) (p = 0.055). Facet location along clavicle length was consistent (average 25%, range 15–35%). But, facet location along clavicle width varied (average 60%, range 10–90%), with males having a more posterior location. For every 10-year increase in age, facet elevation (p = 0.001) and surface area (p < 0.001) increased.Conclusions: CCJ prevalence was 9% in our large osseous population, found more commonly in African-Americans and females. Facet location is predictable with respect to clavicle length, but less so along clavicle width. The clavicular facet may develop at some point in life and continue to grow in size after its appearance.Clinical Relevance: Presence of a CCJ represents a potential overlooked source of anterior shoulder pain and supracoracoid impingement. Epidemiologic and morphological characteristics presented in our study can aid in the identification, clinical understanding, and surgical excision of a symptomatic CCJ. Level of Evidence: Level IV.

Midshaft Clavicle Fractures Treated Nonoperatively Using Figure-of-Eight Bandage: Are Fracture Type, Shortening, and Displacement Radiographic Predictors of Failure?

As there are no clear and unique radiographic predictors of healing disturbances for acute midshaft clavicle fractures, their treatment is still controversial. The aim of the study was to evaluate in midshaft clavicle fractures treated nonoperatively if fracture type (FT), shortening, and displacement, assessed before and after figure-of-eight bandage (F8-B) application, could be considered prognostic factors of delayed union and nonunion. One hundred twenty-two adult patients presenting a closed displaced midshaft clavicle fracture, managed nonoperatively with an F8-B, were enrolled. FT, initial shortening (IS), and initial displacement (ID) were radiographically evaluated at diagnosis, and both residual shortening (RS) and displacement (RD) were measured after F8-B application. The patients were followed up 1, 3, 6, and 12 months post-injury. Multivariate statistical analysis was performed. RD should be considered as radiological predictor of sequelae. Further, an RD equal to 104% of clavicle width was identified as an optimal cut-off point to distinguish between healed and unhealed fractures, and 140% between delayed union and nonunion. Our data pointed out the effectiveness of the F8-B in reducing fracture fragments and restoring clavicular length. In midshaft clavicle fractures of adults, fracture comminution and clavicular shortening did not influence bone healing. On the contrary, RD has been shown as the most likely predictor of both delayed union and nonunion.

Radiological study of the Asian coracoid process and clavicle: Implications for coracoclavicular ligament reconstruction

PurposeIatrogenic coracoid and clavicle fracture is a known complication of drilling bone tunnels during anatomic coracoclavicular ligament reconstruction (ACCR). This study aims to measure the dimensions of coracoid process and clavicle in an Asian population to evaluate the suitability of drilling coracoid and clavicle tunnels for ACCR in Asians. MethodsWidth measurements of 196 coracoids and 189 clavicles were obtained after reviewing all computed tomography (CT) scans of the shoulder performed over a 6 years period. Coracoid measurements were made on the CT slice which showed the maximum cross sectional width of the coracoid base. Medial to lateral measurements of the coracoid width were taken on an axial view, 4 mm above the identified junction of the coracoid base and glenoid base. Antero-posterior clavicle width was measured through a point directly above the midpoint of the coracoid and perpendicular to the long axis of the clavicle. ResultsThe overall mean coracoid width was 14.8 mm ± 2.54 mm (range 9.2–23.3 mm) and clavicle width was 17.1 mm ± 2.72 mm (range 11.1–25.3 mm). ConclusionThe Asian coracoid process is smaller than its Western equivalent. More research is required to validate this conclusion as no cadaveric studies with equivalent measurement techniques have been performed on Asians. Given the potentially narrower dimensions of the Asian coracoid process, extra precautions are required to minimize the risk of iatrogenic coracoid and clavicle fractures.

Gross Morphometry of Pectoral Girdle of Domestic Pigeon (Columba livia)

The pectoral girdle gives strength and range of motion to the wings of birds and plays functional role in flight mechanism of birds. Pectoral girdle of adult domestic pigeon (Columba livia) (n=10) was studied with special reference to the morphological and morphometric parameters. The girdle was composed of three pairs of bones viz. the scapulae, the coracoids and fused clavicles (furcula). The scapula was sword shaped with proximal extremity and a blade. The length and maximum width of scapula were 4.23 cm and 0.56 cm, respectively. The clavicle was in the form of thick curved plate to join the bone of opposite side forming the broad 'U' shaped furculum with rudimentary hypocleideum. The width of clavicle gradually decreased from proximal to distal end. Hypocleideum was not prominent at their meeting point. The curvature length and maximum width of clavicle were 6.38 cm and 1.61 cm, respectively. Coracoid was directed downwards and backwards to articulate the sternum distally. The length was 3.53 cm and width of distal extremity (1.45 cm) was about twice that of proximal one (0.70 cm). The proximal extremity of coracoid was hook like and articulated with proximal extremity of scapula and clavicle to form foramen triosseum (0.35 cm diameter).

Estimation of age at death: examination of variation in cortical bone histology within the human clavicle.

Continuously, numerous human remains of unknown identity are revealed all over the world. One of the elements of the identification process may be a proper assessment of a histological section of bone fragments in order to answer questions related to the age of the subject. The aim of the study was to define an optimum bone fragment to obtain samples for histological examination. The study material consisted of fragments of shafts of left clavicles taken from 39 males and 25 females (aged 22-86). The clavicles came from autopsies conducted between 2005 and 2011 at the Department of Forensic Medicine of Poznan and the Bialystok Medical University. The following were taken into account while estimating the age of the bone remains: clavicle length (CL), clavicle width (CW), clavicle thickness (CT), number of osteons in the field of vision (ON), number of osteons with the Haversian canal of more than 70 μm (HC > 70 μm), average diameter of the Haversian canals (avg. ØHC), area occupied by interstitial lamellae (ILA %), area occupied by osteons (OA %), area occupied by fragments-remnants of osteons remain as irregular arcs of lamellar fragments (OFA %), average thickness of outer circumferential lamellae (avg. OCL, μm), the relation of osteons with the Haversian canal of more than 70 μm in diameter to the total number of osteons (HC > 70 μm, %), at p < 0.00001. The age of the bone remains was estimated using univariate linear regression function. It was determined that the best place for sampling the osseous tissue for the analysis was the shaft of the clavicle. It was stated than the number of osteons with a large diameter increased with age. The relation of osteons with the Haversian canal of more than 70 μm in diameter to the total number of osteons (HC > 70 μm, %). The level of statistical significant was p < 0.00001. All analysed microscopic features of the osseous tissue showed significant statistical changes occurring with age. The exact method for preparing osseous tissue for a microscopic analysis to determine the age of the remains is the preparation of histological sections, as the structure of the osseous tissue does not change while processing the material and the time of preparations is relatively short (7-8 days). The best predictors of age with the use of the function of univariate linear regression were: the diameter of Haversian canal, the number of osteons with Haversian canal of more than 70 μm in diameter, the relation of osteons with Haversian canal bigger than 70 μm in diameter to the total number of osteons as well as fragments of secondary osteons.

Biomechanical Consequences of Coracoclavicular Reconstruction Techniques on Clavicle Strength

Objectives:Lateral clavicle fractures have been reported following coracoclavicular (CC) ligament reconstruction with bone tunnels through the clavicle. Several techniques for CC reconstruction with different drill-hole measurements have been described. Our objective was to evaluate clavicle weakening related to tunnel diameters for common CC-reconstruction techniques.Methods:Testing was performed on 2 groups of 18 matched pair clavicles, which were randomly distributed between groups. There were no significant differences between the groups regarding bone mess density (BMD), clavicle width, age, and gender. One clavicle from each pair was prepared according to one of two reconstruction techniques; the contralateral clavicle was left intact. Both techniques placed 2 tunnels through the medial clavicle, 30 mm and 45 mm from the lateral border. Group 1 (mean age: 53, range: 44-63; mean BMD: 0.48, range: 0.39-0.59) was prepared with 2.4 mm tunnels and augmentation devices. Group 2 (mean age: 56, range: 45-63; mean BMD: 0.47, range 0.35-0.61) was prepared with 6.0 mm tunnels with hamstring grafts and tenodesis screws. A 3-point bending load was applied to the distal clavicles at 15 mm/min until failure. Ultimate failure load and anterior-posterior width 45 mm medial from the lateral border were recorded for each specimen. Strength reduction was determined as the percent reduction in ultimate failure load between paired intact and surgically prepared clavicles. Relative tunnel size was determined as the quotient of tunnel diameter and clavicle width. An independent observer performed all clavicle width measurements. Non-parametric statistics were used (MWU, Kendall’s Tau).Results:The 6.0 mm technique significantly reduced clavicle strength relative to intact (p = 0.02) and caused significantly more strength reduction than the 2.4 mm technique (p = 0.02) (Figure). The 2.4 mm technique was not significantly different from intact. All but one fractures occurred at the medial tunnel. Clavicle width at the medial hole varied highly (mean: 18.1 mm, range: 12.3 - 27.1 mm). There was a significant approximately linear correlation between clavicle width and strength reduction (p = 0.04, tau = -0.36) and between relative tunnel size and strength reduction (p < 0.01, tau = 0.51). Therefore, clavicle strength reductions of 30% and 50% relative to the intact state can be expected with relative tunnel diameters of 34.5% and 49.8% of the clavicle width, respectively. The intra-observer correlation coefficient of the width measurement was excellent (0.99; 95% CI: 0.98 - 0.99).Conclusion:Coracoclavicular ligamentous reconstruction with 6.0 mm tunnels, graft, and tenodesis screws caused significantly greater decreases in the strength of the clavicle when compared to 2.4 mm tunnels with augementation devices and undrilled controls. Additionally, strength reductions correlated highly with the ratio of tunnel width relative to overall clavicle width. This information can help optimize techniques for reconstructing unstable distal clavicles and can influence the intraoperative decision-making process based on the individual clavicle width.

Biomechanical Consequences of Coracoclavicular Reconstruction Techniques on Clavicle Strength

Background: Lateral clavicle fractures have been reported after coracoclavicular (CC) ligament reconstructions with bone tunnels through the clavicle. Purpose: To biomechanically compare clavicle strength following 2 common CC reconstruction techniques with different bone tunnel diameters. Study Design: Controlled laboratory study. Methods: Testing was performed on 2 groups of matched-pair cadaveric clavicles. Clavicles were prepared with either 2.4-mm tunnels and cortical fixation button (CFB) devices or 6.0-mm tunnels with hamstring tendon grafts (TGs) and tenodesis screws; contralateral clavicles were left intact. A 3-point bending load was applied to the distal clavicles at a rate of 15 mm/min until failure. Ultimate failure load and anterior-posterior width of the clavicles 45 mm medial from the lateral border were recorded. Strength reduction was determined as the percentage reduction in ultimate failure load between paired intact and surgically prepared clavicles. Relative tunnel size was determined as the quotient of tunnel diameter and clavicle width, reported as a percentage. Results: The TG technique significantly reduced clavicle strength relative to intact (P = .011) and caused significantly more strength reduction (mean, −30.7%; range, 8.1% to −62.5%) than the CFB technique (mean, −3.8%; range, 34.2% to −28.1%; P = .031). The CFB technique was not significantly different from intact (P = .314). There was a significant correlation between clavicle width and strength reduction (τ = −0.36, P = .04) and between relative tunnel size and strength reduction (τ = 0.51, P = .005). Conclusion: The TG reconstruction technique with 6.0-mm tunnels, grafts, and tenodesis screws caused significantly more reduction of clavicle strength compared with the CFB technique with 2.4-mm tunnels and CFB device. Additionally, relative tunnel width correlated highly with the strength reduction. Clinical Relevance: This information can influence intraoperative decision making based on the individual clavicle width and might influence postoperative treatment protocols. Large bone tunnels may predispose patients to clavicle fractures after anatomic CC reconstructions.

What Role Do Plain Radiographs Have in Assessing the Skeletally Immature Acromioclavicular Joint?

Because of incomplete ossification of the coracoid process and acromion, acromioclavicular joint configuration in the skeletally immature patient differs from that of adults. Although comparison to radiographic standards for this joint is critical in the evaluation of acromioclavicular joint injuries, these standards are not well defined for children or adolescents. We therefore sought to determine (1) the reliability of numerous radiographic measurements of the skeletally immature acromioclavicular joint, including the vertical and shortest coracoclavicular interval, and the acromioclavicular joint offset; (2) the timing of ossification of the acromion and coracoid in males and females; and (3) the differences in the values of these radiographic measurements based on age and sex. This study was based on a total of 485 subjects, 8 to 18 years old, who underwent conventional AP view radiographs of both shoulders. The 485 subjects were included to assess normal configuration around the acromioclavicular joint and 466 of these subjects were evaluated for comparison between both sides. The vertical and shortest coracoclavicular interval, coracoclavicular clavicle width ratio, acromioclavicular joint offset, and difference of the coracoclavicular interval of both sides were measured. A reliability test was conducted before obtaining the main measurements. The relationship of measurements with sex, age, and stage of ossification was evaluated. The vertical and shortest coracoclavicular interval showed excellent reliability (intraclass correlation coefficient ([ICC], 0.918 and 0.934). The acromioclavicular joint offset showed low reliability (ICC, 0.543). The ossification centers of the acromion and the coracoid processes appeared and fused earlier in females than in males. The vertical coracoclavicular interval, which was not affected by partial ossification of the coracoid process, was less than 11 mm in the 90% quantile of total subjects in males and 10 mm in the 90% quantile in females. The difference of the vertical coracoclavicular interval of both sides was less than 50% in 436 of 466 (93.4%) patients. The vertical coracoclavicular interval was the best parameter to assess acromioclavicular joint dislocation in skeletally immature patients. Comparison of both sides of the acromioclavicular joint could help to inform physicians in predicting the need for additional evaluations.

Minimalinvasive Akromioklavikulargelenkrekonstruktion (MINAR)

Reduction and retention of an acromioclavicular (AC) joint dislocation with a button/suture augmentation cerclage (Flip tack, Karl Storz, Tuttlingen, Germany). Dislocation of the AC joint (Rockwood III and V). Chronic instabilities in combination with autogenous replacement of the coracoclavicular ligaments. Lateral clavicular fracture with rupture of the coracoclavicular ligaments. Patients in poor general condition. Local soft-tissue infection. Low-degree dislocation of AC joint (Rockwood I und II). Fracture of the clavicular shaft. Chronic instabilities without ligament replacement. The coracoid process is exposed by a 3 cm long skin incision. A hole is drilled through the coracoid process with the help of a specific aiming device. The suture cerclage is connected to two buttons. One of the buttons is then pushed through the coracoid process. The button is flipped and the suture thereby fixed to the coracoid process. The other anchor is pulled through a hole in the clavicle and the cerclage is secured with a surgical knot after reduction of the AC joint. Application of an abduction splint for 4 weeks (15 degrees). 23 patients with an acute luxation of the AC joint were operated with a minimally invasive coracoclavicular cerclage (five patients with Rockwood type III and 18 patients with Rockwood type V). Mean operative time was 28.6 min. Perior postoperative complications such as nerve and vascular injuries, thoracic injuries, infection, thrombosis, and embolism did not occur. The mean Constant Score was 94.1 points (73-100 points) after a mean of 23.3 months (18-28 months). In two cases, a slight loss of reposition of less than half of the clavicle width in comparison with the contralateral side was observed.

肩鎖関節脱臼に対するＷｅａｖｅｒ変法の検討

It is not easy to maintain anatomical restoration conservatively for acromioclavicular separation. We have reported previously that reconstruction of acromioclavicular or coracoclavicular ligament offers superior result to the simple transfixation of acromioclavicular joint by the Kirschner wires.Nine patients treated by modified Weaver procedure were reviewed and were compared to the five patients by modified Dewar procedure and a patient by modified Neviaser procedure. At review, a functional result of the shoulder including pain, range of motion, muscle weakness and activity of daily living was evaluated . A radiographic result was also evaluated. The displacement less than 50% of the width of clavicle was rated as good restoration.Seven patients were satisfactory in the functional assessment, but the good restoration was maintained only in four patients. The fact that the poor restoration doesn't always lead to poor function, encourages conservative treatments.The fifteen patients who had been treated operatively, were assigned into good restoration group (8) and poor restoration group (7). Functional assesment was significantly (p<0.05) higher in good restoration group. We concluded the operative procedure which can maintain good restoration to be the better treatment. On that standpoint of view, the transfer of coracoacromial ligament as a substitute for coracoclavicular ligament seems to be insufficient for the acromioclavicular separation.