Anatomic study of the coracoid process: safety margin and practical implications

Risk of Cephalic Vein Injury During the Creation of an Anterior Portal in Shoulder Arthroscopy

Background

There is a risk of cephalic vein injury during shoulder arthroscopy. However, limited data regarding its anatomic course are available.

Purpose

To analyze the positional relationship and factors affecting the distance between the coracoid tip and cephalic veins.

Study design

Case series; Level of evidence, 4.

Methods

A total of 80 contrast-enhanced computed tomography images from 80 patients (mean age, 49.6 ± 20.3 years; 61 men) were retrospectively analyzed. The distance between the center of the coracoid tip and the vertical line through the cephalic vein was measured in the axial (D1) and sagittal (D2) planes. The distance between 1 cm lateral to the center of the coracoid tip and the vertical line through the cephalic vein was measured in the sagittal plane (D3). Each distance was compared according to patient sex and laterality. Associations between each distance and the patient's age, height, weight, and body mass index were investigated.

Results

The mean D1 was 18.4 ± 7.3 mm in 59 patients. The mean D2 was 23.4 ± 11.6 mm, and it was within 10 mm in 10 patients (12.5%). The mean D3 was 33.7 ± 12.2 mm. There was no significant difference in D1, D2, and D3 according to patient sex or laterality. A positive correlation was observed only between D3 and patient height (r = 0.320; P = .034).

Conclusion

The cephalic vein was found to travel a mean of 23.4 mm distal and 33.7 mm distal to 1 cm lateral to the coracoid tip. Therefore, Care should be taken to avoid cephalic vein injury when creating an anterior inferior portal or 5-o'clock portal around these areas.

Open reduction and internal fixation of Ideberg type IA glenoid fractures: Tricks, pearls, and potential pitfalls based on a retrospective cohort of 33 patients focusing on the rehabilitation protocol

INTRODUCTION

The standard treatment of anterior glenaoid fractures carrying > 20% of the glenoid fossa is open reduction and internal fixation (ORIF). In the herein study, we report our outcomes in a retrospective cohort of anterior and anteroinferior glenoid rim fractures using an accelerated postoperative rehabilitation protocol. A secondary aim is to describe the surgical steps for ORIF of anterior and anteroinferior glenoid rim fractures using the anterior axillary approach, describing the tricks, pearls, and pitfalls of this surgical technique.

METHODS

A retrospective cohort of skeletally mature patients treated for an anterior glenoid rim fracture carrying > 20% of the glenoid fossa during a 10-year period were operated on using a vertical axillary incision, osteosynthesis with 2.0-mm cortical screws, and labral repair with small diameter metallic anchors and non-absorbable sutures. Rehabilitation began on the first postoperative day, including passive external rotation exercises and active-assisted flexion, adduction, and abduction exercises as tolerated. The exercises are performed with the patient sitting or lying down. Phase 1 is continued for 6-10 weeks until the patient regains painless, normal, or near-normal ROM. Usually by 10 weeks, the fracture and labrum are healed, so phase 2 rehabilitation begins with strengthening and ROM exercises. Radiologic and clinical outcomes, including active range of motion (ROM), glenohumeral stability, and visual analogue scale (VAS) were measured.

RESULTS

About 33 patients (35 fractures) had complete medical records and pre- and post-operative imaging exams available for further analysis regarding the surgical protocol, with a mean of 4.8 years. The mean DASH questionnaire was 3.75 ± 9.0 and the mean CM score was 62.5 ± 0.1. Active flexion and internal rotation were recovered in all patients, while external rotation presented an average loss of 8° (p = 0.12) and abduction of 5° (p = 0.33). The mean VAS was 1.1 ± 0.8. No patient reported major or disabling symptoms, or great difficulty or inability to perform daily or recreational activities. No patient presented residual instability of the glenohumeral joint.

CONCLUSION

In this retrospective cohort, ORIF using a vertical axillary incision, osteosynthesis with 2.0-mm screws, and labral repair with small diameter metallic anchors and non-absorbable sutures was a safe approach, with a minimal risk of complications and residual instability. The accelerated postoperative rehabilitation protocol, allowing immediate passive external rotation of the operated shoulder, resulted in a non-significant loss of ROM compared to the contralateral side. Therefore, we recommend this management strategy for anterior glenoid rim fractures in patients with unstable shoulder joint after traumatic glenohumeral dislocation.

LEVEL OF EVIDENCE IV

Therapeutic Study (Surgical technique and Retrospective cohort).

Three-dimensional morphometric analysis of glenoid in the Indonesian population and its clinical significance

Background

Understanding glenoid morphometry is important in shoulder prosthetic replacement surgery. In total and reverse shoulder arthroplasty, the size of the implants has to be determined according to the morphometry of the shoulder. However, there has been no known data on glenoid morphometry in the Indonesian population.

Methods

Seventy-four computed tomography scans of asymptomatic shoulders were obtained from the medical databases of a third referral hospital in Jakarta. Mimics Research 21.0 was used to reconstruct 3D models of the scapula from the DICOM files. The morphometry parameters included were glenoid fossa height (GFH), maximum glenoid fossa width (MGW), glenoid width at center of the glenoid fossa (CGW), vertical distance between maximum width and center (VDMC), glenoid version angle (GVA), glenoid inclination (GI), glenopolar angle (GPA), glenoid vault depth (GVD), coracoid length (CL), coracoid midpoint length (CML), coracoid tip height (CTH) and width (CTW), and coracoid midpoint height (CMH) and width (CMW).

Results

Our study found the average Indonesian GFH was 30.24 mm, the MGW was 24.03 mm, the CGW was 22.46 mm, the VDMC was 3.67 mm, the GPA was 42.76°, the GVD 18.8 mm, the GVA was 2.39° retroverted, the GI was 3.15° superiorly inclined, the CL was 37.76 mm, the CML was 18.89 mm, the CTW was 13.31 mm, the CTH was 8.52 mm, the CMW was 14.21 mm, and the CMH was 10.46 mm. All parameters except VDMC, GVA, and GI showed significant differences between male and female subjects Meanwhile, there was no significant difference in dimension and orientation of the glenoid and coracoid between the right and left shoulder.

Conclusion

Our study showed a lower value of MGW, GFH, and GVD compared to other Asian ethnicities. These results may be helpful in designing smaller prostheses suitable for Indonesian glenoids.

Qualitative and Quantitative Anatomic Descriptions of the Coracoclavicular and Acromioclavicular Ligaments: A Systematic Review

Purpose

Methods

Results

Conclusions

Clinical Relevance

Modified Arthroscopic Latarjet Procedure: Button Fixation Without Splitting of the Subscapularis

The Latarjet procedure is used for the treatment of anterior glenohumeral instability in the presence of bone loss. One decade after a fully arthroscopic Latarjet procedure was described, this technique has been modified to reduce the risk of complications and improve the fixation method. We aimed to simplify the components of this surgical procedure.

A gender-based comparison of coracoid and glenoid anatomy: CT analysis and discussion of potential impact on the Latarjet procedure

BACKGROUND

The success of the modified Latarjet procedure depends on proper sizing of the coracoid graft. There is no information available regarding the morphometric relationship between the glenoid cavity and the coracoid process for the South African population. This study aims at measuring the relationship between the glenoid and coracoid morphometries and investigates their gender-related differences.

METHODS

Glenohumeral computerized tomography scans of 100 consecutive patients were considered for this study. Morphometric measurements were performed after aligning the coracoid and glenoid in their optimum orientation. These measurements were performed by 2 independent observers. The ratio between glenoid and coracoid measurements was calculated and statistically compared using the Mann-Whitney U test. Intraclass correlation coefficients were calculated to analyze interobserver reliability. All the statistical tests were performed in SPSS v.26, and power calculations in G∗Power v.3.1.

RESULTS

An average intraclass correlation coefficient value of 0.79 suggested that the interobserver reliability was good. Except for coracoid length, statistically significant (P < .05) gender differences were observed for all the other morphometries. The coracoid width (16.5 ± 1.4 mm vs. 14.7 ± 1.4 mm) and height (13.6 ± 1.6 mm vs. 10.5 ± 1.5 mm) differed between genders by 1.8 and 3.1 mm, respectively. The glenoid anteroposterior (AP) (25.3 ± 2.9 mm vs. 23.2 ± 2.4 mm) and superioinferior (36.9 ± 1.9 mm vs. 33.7 ± 2.6 mm) measurements differed by 2.1 and 3.3 mm, respectively, between the males and the females. The ratio between the AP width of the glenoid and the coracoid height was also found to be significantly different (P < .05) between the gender groups. These morphometric ratios for the coracoid width (0.66 ± 0.09 mm vs. 0.64 ± 0.08 mm) and the coracoid height (0.55 ± 0.09 mm vs. 0.46 ± 0.07 mm) differed between genders by 0.02 and 0.09, respectively.

CONCLUSION

Measurements taken from computerized tomography scans showed significant differences between genders in absolute measurements and in the ratio of the coracoid height to the glenoid AP distance. This could have implications on the ability of the Latarjet procedure to compensate for bone loss in female patients.

Traditional versus congruent-arc Latarjet anatomic and biomechanical perspective

The congruent-arc Latarjet (CAL) allows reconstruction of a greater percentage of glenoid bone deficit because the inferior surface of the coracoid is wider than the lateral edge of the coracoid used with the traditional Latarjet (TL).

Biomechanical studies have shown higher initial fixation strength between the graft and the glenoid with the TL.

In the TL, the undersurface of the coracoid, which is wider than the medial edge used with the CAL, remains in contact with the anterior edge of the glenoid, increasing the contact surface between both bones and thus facilitating bone consolidation.

The shorter bone distance around the screw with the CAL is potentially less tolerant of screw-positioning error compared to the TL. Moreover, the wall of the screw tunnel is potentially more likely to fracture with the CAL due to the minimal space between the screw and the graft wall.

CAL may be very difficult to perform in patients with very small coracoids such as small women or skeletally immature patients.

Radius of curvature of the inferior face of the coracoid graft (used with the CAL) is similar to that of the native glenoid. This may potentially decrease contact pressure across the glenohumeral joint, avoiding degenerative changes in the long term.

Cite this article: EFORT Open Rev 2021;6:280-287. DOI: 10.1302/2058-5241.6.200074

A cadaveric morphometric analysis of coracoid process with reference to the Latarjet procedure using the "congruent arc technique"

INTRODUCTION

Congruent arc Latarjet procedure involves rotating the coracoid process so that its inferior surface is flush with the glenoid face, owing to their matching radius of curvature (ROC). However, there has been no cadaveric study to actually measure and compare the ROC of coracoid with glenoid, especially in Indian population.

MATERIALS AND METHODS

44 shoulders were dissected in 24 cadavers to measure usable length of coracoid process, width, height, ROC of coracoid and glenoid as well as ulnar length (as proxy of cadaver height). Critical coracoid height and length were estimated based on screw sizes of 2.7 mm, 3.5 mm, 4 mm and 4.5 mm, and pair concordance between height and length calculated. ROC of coracoid and glenoid were compared to measure extent of congruency.

RESULTS

The mean usable length of coracoid process, width and height at mid-point were 21.8 mm, 13.7 mm and 8.6 mm, respectively. Out of the different screw sizes, 2.7 mm screws were found safe in 82% shoulders. 24 coracoid-glenoid pairs fulfilled the operational definition (≤ 5 mm) of congruency while rest 20 were seemingly incongruent chiefly due to coracoid variations, with mean ROC difference 4.13 mm (95% CI 1.51-6.74 mm). The ulnar length was significantly smaller in the incongruent ROC group (p = 0.0002).

CONCLUSIONS

The available length as well as height of the transferred coracoid must be considered when deciding optimum diameter fixation screws in Latarjet procedure. Owing to smaller anatomic dimensions of coracoid in Indian population, 2.7-mm screws provide the safest fixation option. Also, the ROC of coracoid and glenoid does not match in substantial proportion of the cadavers. Pre-operative planning should include a CT-based assessment of glenoid and coracoid dimensions to decide the technique of Latarjet procedure and the optimum diameter fixation screws required.

Basic morphological characteristics of coracoid grafts obtained by open and arthroscopic Latarjet techniques: A comparative study

BACKGROUND

A knowledge of the anthropometric characteristics of the coracoid graft (CG) that can be obtained by the open and arthroscopic Latarjet techniques may be beneficial in the preoperative planning and intraoperative decision making for coracoid osteotomy and transfer. We have not found any study that compared the morphology of the CG that can be obtained from open and arthroscopic Latarjet techniques. The purpose of this study was to verify if the basic anthropometric characteristics of CGs are equivalent.

HYPOTHESIS

We hypothesize that the basic anthropometric characteristics of the CGs are similar.

METHODS

Twenty fresh-frozen human paired cadaveric shoulder specimens that had been randomly distributed in two groups of 10 specimens each were used. Two surgeons, each with experience in performing the open and arthroscopic Latarjet technique, performed these procedures in each of the respective groups (OG, open group; AG, arthroscopic group). A CT scan was performed. Using the volume rendering technique, a metric analysis of the volume, area and length of the CG were performed, evaluated and statistically analysed.

RESULTS

There were no significant differences in length (p=0.162) (mean length, 22.6mm for OG and 23.6mm for AG). There were significant differences in the volume (p=0.031) and area (p=0.007) of the CG, being lower in the OG (mean volume, 2.8 cm³ for OG and 3.6 cm³ for AG; mean area, 9.9 cm² for OG and 12.8 cm² for AG). No significant differences were observed by sex or laterality.

CONCLUSION

The mean lengths of the CGs that were obtained by each technique are equivalent. However, the areas and volumes of the grafts are different, being lower in the open surgery. These differences have not been an impediment to perform the technique. Our results corroborates that consolidation is more related to the preparation and placement than to the anthropometric characteristics of the CG. No significant differences were observed by sex or laterality.

LEVEL OF EVIDENCE

Basic Science.

Thinking outside the glenohumeral box: Hierarchical shape variation of the periarticular anatomy of the scapula using statistical shape modeling

Variation in the shape of the glenoid and periarticular anatomy of the scapula has been associated with shoulder pathology. The goal of this study was to identify the modes of shape variation of periarticular scapular anatomy in relation to the glenoid in nonpathologic shoulders. Computed tomography scans of 31 cadaveric scapulae, verified to be free of pathology, were three-dimensionally reconstructed. Statistical shape modeling and principal component analysis identified the modes of shape variation across the population. Corresponding linear and angular measurements quantified the morphometric variance identified by the modes. Linear measures were normalized to the radius of the inferior glenoid to account for differences in the scaling of the bones. Five modes captured 89.7% of total shape variation of the glenoid and periarticular anatomy. Apart from size differences (mode 1: 33.0%), acromial anatomy accounted for the largest variation (mode 2: 32.0%). Further modes described variation in glenoid inclination (mode 3: 11.8%), coracoid orientation and size (mode 4: 9.0%), and variation in coracoacromial (CA) morphology (mode 5: 3.1%). The average scapula had a mean acromial tilt of 49 ± 7°, scapular spine angle of 61 ± 6°, the glenoid inclination of 84 ± 4°, coracoid deviation angle of 26 ± 4°, coracoid length of 3.7 ± 0.3 glenoid radii, and a CA base length of 5.6 ± 0.5 radii. In this study, the identified shape modes explain almost all of the variance in scapular anatomy. The acromion exhibited the highest variance of all periarticular anatomic structures of the scapula in relation to the glenoid, which may play a role in many shoulder pathologies.

Similar Results in Return to Sports, Recurrences, and Healing Rates Between the Classic and Congruent-Arc Latarjet for Athletes With Recurrent Glenohumeral Instability and a Failed Stabilization

PURPOSE

To compare the return-to-sport rate, functional outcomes, and complications of the "classic Latarjet" surgery with those of the "congruent arc Latarjet" surgery in athletes with recurrent glenohumeral instability and failed previous stabilization procedures.

METHODS

All the included patients were operated between May 2009 and April 2017. The inclusion criteria were athletes with recurrent anterior glenohumeral instability, a glenoid bone defect greater than 20%, at least 1 previous failed stabilization surgery operated with the classic or the congruent-arc Latarjet procedures, and a minimum 2 years of follow-up. Return to sports, range of motion (ROM), the Rowe score, a visual analog scale for pain, and the Athletic Shoulder Outcome Scoring System score were used to assess functional outcomes. Complications were also evaluated.

RESULTS

A total of 135 athletes were included in the study (55 patients were operated with the classic technique and 80 with the congruent arc technique). The mean follow-up was 40.3 months (range, 24-88 months) and the mean age was 26.5 years (range, 18-45 years). Overall, 87% were able to return to sports and 92% returned at the same level. No significant difference regarding return to sports was found between the groups. No significant difference in shoulder ROM was found between preoperative and postoperative results. The Rowe, visual analog scale, and Athletic Shoulder Outcome Scoring System scores showed statistical improvement after operation (P < .001). No significant difference in shoulder ROM and functional scores was found between patients operated with the classic and congruent arc procedures. There were 6 recurrences (4%). There was no significant difference in the recurrence rate between groups. The bone block healed in 92% of the cases.

CONCLUSIONS

In athletes with recurrent anterior glenohumeral instability and a failed previous operative repair, the Latarjet procedure produced excellent functional outcomes and most athletes returned to sport at their preinjury level with a very low rate of recurrences, regardless of whether the Latarjet was performed with the classic or with the congruent arc technique.

LEVEL OF EVIDENCE

Retrospective comparative study; Level of evidence, 3.

Are the Classic and the Congruent Arc Latarjet Procedures Equally Effective for the Treatment of Recurrent Shoulder Instability in Athletes?

BACKGROUND

There is a lack of evidence in the literature comparing outcomes between the classic and the congruent arc Latarjet procedures in athletes.

PURPOSE

To compare return to sports, functional outcomes, and complications between the classic and the congruent arc Latarjet procedures in athletes with recurrent glenohumeral instability.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Between June 2009 and June 2017, 145 athletes with recurrent anterior glenohumeral instability underwent surgery with the Latarjet as a primary procedure in our institution. The classic procedure was used in 66 patients, and the congruent arc method was used in 79 patients. Return to sports, range of motion (ROM), the Rowe score, a visual analog scale (VAS) for pain in sports activity, and the Athletic Shoulder Outcome Scoring System (ASOSS) were used to assess functional outcomes. Recurrences were also evaluated. The postoperative bone block position and consolidation were assessed with computed tomography.

RESULTS

In the total population, the mean follow-up was 41.3 months (range, 24-90 months) and the mean age was 25.3 years (range, 18-45 years). In total, 90% of patients were able to return to sports; of these, 91% returned at their preinjury level of play. No significant difference in shoulder ROM was found between preoperative and postoperative results. The Rowe, VAS, and ASOSS scores showed statistical improvement after operation (P < .001). The Rowe score increased from a preoperative mean of 42.8 points to a postoperative mean of 95.2 points (P < .01). Subjective pain during sports improved from 3.2 points preoperatively to 0.7 points at last follow-up (P < .01). The ASOSS score improved significantly from a preoperative mean of 46.4 points to a postoperative mean of 88.4 points (P < .01). No significant differences in shoulder ROM and functional scores were found between patients who received the classic vs congruent arc procedures. There were 5 recurrences (3.5%): 3 dislocations (2%) and 2 subluxations (1%). No significant difference in the recurrence rate was noted between groups. The bone block healed in 134 cases (92%).

CONCLUSION

In athletes with recurrent anterior glenohumeral instability, the Latarjet procedure produced excellent functional outcomes. Most athletes returned to sports at their preinjury level, and the rate of recurrence was very low, regardless of whether the patients received surgery with the classic or congruent arc technique.

Anterior shoulder anatomy and subcoracoid impingement: An anatomical study

OBJECTIVE

The aim of our study was to describe the anatomy of the anterior shoulder, specifically structures potentially involved in subscapularis tears pathophysiology and also to identify structures at risk during surgical approaches of this area.

MATERIALS AND METHODS

We designed an observational, experimental study based on cadaveric models. Dissection was performed and several structures of the anterior shoulder were characterized including the subscapularis, coracoid morphology, the coracoacromial ligament, coraco-humeral distance, and the axillary and musculocutaneous nerves.

RESULTS

Our sample included 16 shoulders. The coracoacromial ligament presented two bands in 37.5%, and these variants were significantly wider and thinner, and were associated with inferior coraco-humeral distance in internal rotation. The subscapularis footprint was longer and the coracoid process was bigger in male specimens, and the median coracoid angle was 122°, corresponding to a Leite-Torres type I. The Subscapularis showed a median thickness of 0.7cm, while the coraco-humeral distance in our sample ranged from 0.30cm in internal rotation to 0.85cm in external rotation. Neurologic relevant structures were at least more than 2.55cm from the coracoid tip.

CONCLUSIONS

This is the first paper to explore the eventual relationship between the presence of a double band coracoacromial ligament variant and subcoracoid impingement. Also, to our knowledge, this is the first cadaveric model study to postulate a possible anatomic base for subcoracoid impingement, as the SS myotendinous junction thickness was found to be greater than the coraco-humeral distance in neutral position and in IR.

Morphometric analysis of the coracoid process and glenoid width: a 3D-CT study

Background

Data regarding the parameters of the coracoid process and glenoid width are insufficient, and information on gender, age, and ethnic differences in the parameters appear lacking in the Chinese population. This study aimed to investigate the morphometric parameters in the coracoid process and glenoid width.

Methods

Using our institution’s electronic database, we selected 84 patients (55 males and 29 females) who underwent a shoulder computed tomography (CT) scan from January 2017 to May 2018 in this study. Mimics19.0 software was used for three-dimensional (3D) reconstruction of CT and to measure the morphometric parameters of the coracoid process and glenoid width. Subgroup analyses stratified by gender and age were conducted and the parameters were compared with previously published reports. All data were statistically analysed by SPSS23.0 Statistical Package.

Results

A positive and significant relationship between the coracoid process and the glenoid width (R > 0.758, P < 0.01) was found. The midpoint width represents 52% (41–62%) of the glenoid width; the midpoint height, 40% (31–53%) of the glenoid width. Significant differences in all parameters between males and females were noted (P < 0.05). No significant differences among the age groups were observed (P > 0.05), whereas significant differences in almost all parameters between the ethnic groups were observed (P < 0.05).

Conclusion

Our results could supplement the information in the shoulder joint database with morphometric parameters and provide a reference for theoretical research on coracoid osteotomy, which may in turn help surgeons in the evaluation of coracoid process transfer.

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

PURPOSE

Iatrogenic 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.

METHODS

Width 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.

RESULTS

The 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).

CONCLUSION

The 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.

Predictors of safety margin for coracoid transfer: a cadaveric morphometric analysis

Background

The purpose of this study was to investigate the relationship between the bone length available for coracoid transfer without coracoclavicular ligament injury and the distance from the coracoid tip to the attachments of the coracoacromial ligament or pectoralis minor. We hypothesized that cadaver height and the soft tissue attachments on the coracoid process were predictive factors for sufficient bone length for coracoid transfer.

Methods

This study included 28 shoulders from Japanese cadavers: 19 male and 9 female. The distance from the coracoid tip to the distal attachment of the coracoclavicular ligament and the anterior and posterior margins of the coracoacromial ligament or pectoralis minor on the coracoid process were measured.

Results

The mean available length for coracoid transfer was 24.8 ± 3.4 mm. There was a significant difference in length between male and female subjects, being 26.0 ± 2.9 mm and 22.2 ± 3.0 mm, respectively (p = 0.004). High positive correlations were found between the length of the coracoid transfer and cadaver’s height (r = 0.48, p = 0.009) and the distance from the coracoid tip to the anterior coracoacromial ligament attachment (r = 0.63, p < 0.001). The receiver operating characteristic curve area under the curve for cadaver height was 0.72 while that for distance from coracoid tip to anterior coracoacromial ligament was 0.88 when predicted for a sufficient length for coracoid transfer > 25 mm.

Conclusions

Our findings will aid surgeons in preoperative planning and performing of osteotomy of the coracoid safely by predicting the available length of coracoid bone graft.

Intraoperative and anatomic dimensions of the coracoid graft as they pertain to the Latarjet-Walch procedure

BACKGROUND

Our objective was to study the anatomic and intraoperative coracoid measurements with an aim to closely replicate the Latarjet-Walch technique and find the similarities and dissimilarities in our population.

METHODS

In the cadaveric study, 20 shoulders in 10 fresh cadavers were dissected, and the coracoid length, width, and thickness were measured. In the intraoperative study, 10 patients underwent the classic Latarjet procedure according to the Walch technique. The harvested coracoid graft was analyzed for the length of the coracoid, the distance of the inferior hole from the lateral margin of the coracoid graft, and the width of the coracoid graft at the inferior and superior hole.

RESULT

The average distance from the tip of the coracoid to the trapezoid insertion was 25.4 mm (standard deviation [SD], 1.7 mm). The mean width of the undersurface of the coracoid was 14.2 mm. The average length of the graft after harvesting was 25.1 mm (SD, 1 mm). The average distance between the lateral border and the inferior hole was 5.5 mm (SD, 1.1 mm). We used 25-mm malleolar screws in 3 shoulders and 30-mm malleolar screws in 7 shoulders.

CONCLUSION

The"7-mm" rule of Walch could be followed in our population. The medial surface width of the coracoid in our Indian morphology was an average of 7 mm; hence, malleolar screws of 30 and 25 mm were used to fix the graft on the glenoid.

Quantitative Assessment of the Coracoacromial and the Coracoclavicular Ligaments With 3-Dimensional Mapping of the Coracoid Process Anatomy: A Cadaveric Study of Surgically Relevant Structures

PURPOSE

To perform a quantitative anatomic evaluation of the (1) coracoid process, specifically the attachment sites of the conjoint tendon, the pectoralis minor, the coracoacromial ligament (CAL), and the coracoclavicular (CC) ligaments in relation to pertinent osseous and soft tissue landmarks; (2) CC ligaments' attachments on the clavicle; and (3) CAL attachment on the acromion in relation to surgically relevant anatomic landmarks to assist in planning of the Latarjet procedure, acromioclavicular (AC) joint reconstructions, and CAL resection distances avoiding iatrogenic injury to surrounding structures.

METHODS

Ten nonpaired fresh-frozen human cadaveric shoulders (mean age 52 years, range 33-64 years) were included in this study. A 3-dimensional coordinate measuring device was used to quantify the location of pertinent bony landmarks and soft tissue attachment areas. The ligament and tendon attachment perimeters and center points on the coracoid, clavicle, and acromion were identified and subsequently dissected off the bone. Coordinates of points along the perimeters of attachment sites were used to calculate areas, whereas coordinates of center points were used to determine distances between surgically relevant attachment sites and pertinent bony landmarks.

RESULTS

The CAL had a single consistent acromial attachment (mean area 77 mm [51.9, 102.2]) and then bifurcated into 2 bundles, anterior and posterior, that separately inserted on the lateral aspect of the coracoid. The footprint areas were 54.4 mm² [31.7, 77.2] and 30.6 mm² [23.4, 37.7] for the anterior and posterior CAL bundles, respectively. These anterior and posterior bundles attached 10.6 mm [8.4, 12.9] and 24.8 mm [12.3, 27.4] medial and proximal to the apex of the coracoid process, respectively. The minimum distance between the coracoid apex and the trapezoid ligament was 25.1 mm [22.1, 28.1] and was noted to be different in males (28.1 mm [25.1; 31.2]) and females (22.0 mm [18.2, 25.9]). The most lateral insertion of the CC ligaments on the clavicle the AC joint was 15.7 mm [13.1, 18.3]. The distance between the most medial to the most lateral point of the CC ligaments on the clavicle was 25.6 mm [22.3, 28.9], which accounted for 18.2% [15.8, 20.6] of the clavicle length.

CONCLUSIONS

In contrast to previous findings, 2 different coracoid attachments (anterior and posterior bundles) of the CAL were consistently identified in all specimens. Moreover, a coracoid osteotomy for a bone graft for the Latarjet procedure should be performed at less than 28.1/22 mm from the apex of the coracoid in male/female patients, respectively. The CC ligaments' attachments on the clavicle were located 15.7 mm from the AC joint, which should be considered for reconstruction.

CLINICAL RELEVANCE

During the Latarjet technique, to maintain the integrity of the CC ligaments, precise knowledge of differences between male and female anatomy is necessary during a coracoid osteotomy. Furthermore, when reconstructing the AC joint, the distance from the lateral aspect of the clavicle and the size of the attachments areas should be considered to better replicate the native anatomy.

Coracoid Process Morphology using 3D-CT Imaging in a Malaysian Population

Introduction: The aims of this study are to define the coracoid process anatomy in a Malaysian population, carried out on patients in Hospital Serdang with specific emphasis on the dimension of the base of coracoid process which is important in coraco-acromial (CC) ligament reconstruction, to define the average amount of bone available for use in coracoid transfer, and to compare the size of coracoid process based on gender and race, and with findings in previous studies.

Materials and Methods: Fifteen pairs of computed tomography (CT) based 3-dimensional models of shoulders of patients aged between 20 to 60 years old were examined. The mean dimensions of coracoid were measured and compared with regards to gender and race. The data were also compared to previously published studies.

Results: The mean length of the coracoid process was 37.94 ± 4.30 mm. Male subjects were found to have larger-sized coracoids in all dimensions as compared to female subjects. The mean tip of coracoid dimension overall was 19.99 + 1.93mm length × 10.03 + 1.48mm height × 11.63 + 2.12mm width. The mean base of coracoid dimension was 18.96 + 3.71mm length × 13.84 + 1.76mm width. No significant differences were observed with regards to racial denomination. The overall coracoid size measurements were found to be smaller compared to previous studies done on the Western population.

Conclusion: This study may suggest that Malaysians have smaller coracoid dimension compared to Caucasians. The findings further suggest that the incidence of coracoid fracture and implants pull out in Malaysian subjects may be higher.

Traditional Versus Congruent Arc Latarjet Technique: Effect on Surface Area for Union and Bone Width Surrounding Screws

PURPOSE

To compare the surface area available for bony contact and the width of bone on each side of the Latarjet fixation screws in the traditional Latarjet technique versus the congruent arc modification of the Latarjet technique.

METHODS

Computed tomographic scans of 24 shoulders in patients with glenohumeral instability who underwent multiplanar reconstruction measurements with multiple dimensions of the coracoid. The surface area of the coracoid available for bony contact with the anterior glenoid and width of bone on each side of a 3.5-mm screw was compared for the traditional Latarjet technique versus the congruent arc modification.

RESULTS

The surface area available for bony contact to the anterior glenoid was 5.65 ± 1.08 cm² using the traditional Latarjet technique compared with 3.64 ± 0.93 cm² using the congruent arc modification of the Latarjet technique (P < .001). The mean width of bone on each side of a 3.5-mm screw was 7.1 ± 1.0 mm using the traditional Latarjet technique compared with 4.1 ± 1.0 mm using the congruent arc modification (P < .001).

CONCLUSIONS

The traditional Latarjet technique has greater bony contact with the glenoid and greater bone width on each side of the screws compared with the congruent arc modification of the Latarjet technique. This potentially allows for a larger surface for healing in the traditional Latarjet technique. Moreover, because of smaller width of the bone around the screw, the congruent arc modification is potentially less tolerant of screw-positioning error compared with the traditional Latarjet technique.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Anatomic Variation in Morphometry of Human Coracoid Process among Asian Population

Ethnic origin plays an important role in bone morphometry. Studies examining the influence of coracoid process have focused primarily on adults and have not included people from diverse Asian ethnic backgrounds. Our goal was to explore ethnic differences in morphometry of coracoid among Asian population. We performed morphometric measurements of coracoid process on cadaveric shoulders and shoulder CT scans from 118 specimens. The cadaveric sample included Indian (46%), Chinese (27%), and Myanmarese (27%) subjects, while the CT scans sample included Chinese (67%) and Malay (33%) subjects. The morphometric measurements were performed using digital caliper and software developed at Golden Horses Health Sanctuary (GHHS). In the Indian cadaveric shoulders, the coracoid process is better developed than the other groups with the exception of the tip width of coracoid process. There are significant differences in almost all measurements (P < 0.05) between the ethnic groups. On the other hand, the morphometry of coracoid process from CT scans data is bigger in Chinese than Malay subjects when stratified by sex (P < 0.05). Moreover, in all morphometric measurements, the females had smaller measurements than males (P < 0.05). Understanding such differences is important in anatomy, forensic and biological identity, and orthopaedic and shoulder surgeries.

Anatomical study of the coracoid process in Mongolian male cadavers using the Latarjet procedure

Background

The Latarjet procedure addresses recurrent anterior shoulder instability in the context of a significant bony defect. However, the bony and soft tissue anatomy of the coracoid in coracoid transfer procedures has not yet been defined in Mongolian men. The aims of this study were to describe the soft tissue attachments of the coracoid regarding the bony anatomy, define the average amount of bone available for coracoid transfer, analyze the characteristics of the pectoralis minor and coracoid, and study the relationship between the bony dimensions of the coracoid and body length in Mongolian men.

Methods

We dissected 30 shoulders from 15 male Mongolian cadavers, exposing the coracoid process and attached anatomical structures including the lateral clavicle and acromion, then measured the bony dimensions of the coracoid and the locations and sizes of the coracoid soft tissue footprints.

Results

The mean length of the coracoid available for transfer was 23.93 ± 2.32 mm. The mean length of the coracoid was 42.10 ± 2.3 mm, and the mean width and height of the coracoid midpoint were 15.29 ± 1.70 mm and 11.61 ± 1.98 mm, respectively. The pectoralis minor was part of the joint capsule and passed over the coracoid in some samples. The mutation rate of the pectoralis minor footprint, which was asymmetrical and irregular, was 23.33 %. Statistical analysis involved a multiple linear regression equation.

Conclusions

The average amount of bone available for use in coracoid transfer in Mongolian men was less than that of other populations. Mutation of the pectoralis minor may induce intraoperative capsule injury because this muscle passes over the coracoid deep to the joint capsule of the glenohumeral joint and constitutes part of the shoulder joint, strengthening the joint. Statistically, higher coracoids appeared in shorter patients and longer coracoids appeared in taller patients. Surgically, great care should be taken to consider a patient’s height to precisely implement the congruent-arc Latarjet technique.

Midterm results of coracoclavicular stabilization with double augmentation for acute acromioclavicular dislocation

Introduction

Numerous techniques have been introduced for the treatment of acute acromioclavicular (AC) joint dislocation. We aim to report the midterm results of coracoclavicular (CC) stabilization with double augmentation for the acute AC joint dislocation.

Case description

Forty-three patients who underwent surgery for acute AC joint dislocation were followed up for an average of 59.6 months (range 40–97). The study composed of two treatment groups: group S, with 25 patients, in whom two suture anchors were used; and group B, with 18 patients, in whom a suture anchor and a double flip-button device were used, however the techniques in both groups are based on the same principle which is double augmentation. Postoperative evaluations were made retrospectively, clinically, and radiographically.

Discussion and Evaluation

At the last follow-up, the mean Constant score was 91.2 (range 74–100) and the UCLA scale was 31.4 (range 24–35). The overall ratio of the CC distance in the injured shoulder to that in the uninjured shoulder, expressed as a percentage, significantly decreased, to 93.4 ± 22.7 %, immediate postoperatively, and significantly increased, to 113.8 ± 23.4 %, at the final follow-up. Complete reduction of the AC joint was achieved in 34 patients (79.1 %), and 8 patients (18.6 %) exhibited a slight loss of reduction, although their functional outcomes were good.

Conclusions

The results of this study provide evidence that double augmentation is effective in the treatment of acute AC dislocation.

Level of evidence

Therapeutic study, case series, Level IV.

Complex shoulder injuries in sports

A 26-year-old Olympic wrestling athlete presented with a pectoralis major muscle injury, glenohumeral instability and acromioclavicular joint dislocation separately. The patient underwent surgical treatment to repair these injuries. The pectoralis major muscle was reconstructed with a semitendinosus tendon graft using the endobutton technique, as described by Pochini et al. Treatment of the traumatic anterior instability was performed using the technique described by Bristow-Latarjet, and the acromioclavicular joint dislocation was repaired using the modified technique of Weaver-Dunn with the aid of an anchor. The athlete exhibited a rapid recovery and could return to normal activities 6 months after surgery. At present, 18 months postoperatively, the patient is asymptomatic.