Glenoid Diameter Research Articles

Arthroscopic subscapularis augmentation of the classic Bankart repair leads to satisfactory clinical and functional mid-term outcomes in patients with recurrent anterior shoulder instability and less than a subcritical glenoid bone loss.

The long-term failure rate of the arthroscopic Bankart repair may reach unacceptable values, raising the need to augment this classic procedure. Arthroscopic subscapularis augmentation is the tenodesis of the upper part of the subscapularis tendon to the anterior glenoid rim. The aim of the study was to evaluate the mid-term clinical and functional outcomes of patients operated with arthroscopic subscapularis augmentation of the classic Bankart repair due to recurrent anterior shoulder instability. This is a retrospective single-centre case series study with prospectively collected data. All patients suffered from recurrent anterior shoulder instability and had glenoid bone loss less than 13.5% of the inferior glenoid diameter (subcritical glenoid bone loss). Patients with greater anterior glenoid bone defect, engaging Hill-Sachs lesions, multidirectional instability or subscapularis insufficiency were excluded. Postoperatively, all patients were evaluated for recurrence and apprehension. The patient's shoulder range of motion and functional scores were recorded. The final study cohort included 34 patients with a mean age of 29.3 ± 10.2 years. The mean follow-up period was 42.4 ± 10.7 months (range, 24-62 months). Two out of 34 patients (5.8%) experienced a re-dislocation postoperatively, while one additional patient had a subjective feeling of apprehension. External rotation at the last follow-up was lower compared to preoperative values or the healthy side, but only one patient had restrictions in his sporting activities. The functional scores were significantly increased compared to the preoperative values. Twenty-two out of 26 patients (84.6%) returned to the same level of sporting activities, and 30/34 patients (88.2%) were highly satisfied with the results. Arthroscopic subscapularis augmentation of the classic Bankart repair reduces the dislocation recurrence rate and leads to satisfactory clinical and functional mid-term outcomes in patients with recurrent anterior shoulder instability and less than a subcritical glenoid bone loss. Level IV.

Poster 152: Clinical Outcomes for Dermal Allograft Glenoid Augmentation in Patients With Anterior Shoulder Instability and Subcritical Bone Loss

Objectives: To assess minimum 1-year magnetic resonance imaging (MRI) and clinical outcomes for 20 cases of dermal allograft augmentation of subcritical glenoid bony defects. Methods: Twenty patients with subcritical glenoid bone loss underwent arthroscopic dermal allograft augmentation along with labral repair. All patients were evaluated with postoperative MRI at a minimum of 12-month follow-up. Preoperative and postoperative patient-reported outcomes were collected including University of California Los Angeles Shoulder (UCLA) scores, Visual Analogue Scale (VAS) scores, and American Shoulder and Elbow Surgeons (ASES) scores. Scores were assessed for statistical significance using the analysis of variance test. Results: Average postoperative follow-up was 19 months (range 12-54 months). The average preoperative bony defect size was 16% (range 6.6-39%), with 19 of the patients having defects under 20%. Postoperative MRIs (Figure 1) revealed an average of 32% (range 27.7-37.4%) increase in glenoid diameter size and the average glenoid size was restored to 102.3% (range 94-114%), with excellent incorporation of the graft. There were statistically significant improvements in preoperative and postoperative scores with respect to UCLA scores (21.25 to 33.7, p < 0.05), VAS scores (5.4 to 0.2, p < 0.05) and ASES scores (58.6 to 96.4, p < 0.05). One patient had a recurrent traumatic dislocation (5%) and underwent a Latarjet procedure at 13 months from the index surgery. At the time of the Latarjet, the dermal allograft was harvested and sent for histologic analysis. Histologic analysis of the glenoid augmentation graft at the time of revision surgery revealed recellularization with fibroblast-like cells, revascularization, and incorporation of the graft into the surrounding tissue with bony ingrowth. (Figure 2) Conclusions: Subcritical glenoid bone loss has been associated with high failure rates when treated with standard labral repair. While a Latarjet procedure can provide stability, high complication rates and the risk of long-term arthritis makes this procedure less than ideal when bone loss is under 20%. Arthroscopic labrum repair with the addition of a dermal allograft is a viable option in patients with subcritical bone loss. In the case series with 1-year follow-up, 20 patients who underwent arthroscopic labrum repair with the addition of a dermal allograft had a significant improvement in outcome scores, and excellent incorporation of the graft as seen on MRI at 12 months from the index procedure. In the 1 failure that later underwent revision surgery, histologic analysis demonstrated recellularization and revascularization, with incorporation of the graft.

Poster 156: Intraobserver and Interobserver Reliability in Glenoid Track Measurement

Objectives: The purpose of our study was to determine the accuracy and reliability of measuring on- and off-track lesions within our institution using the circle line method. Methods: Electronic medical records between 2009 and 2019 were reviewed for active-duty military personnel who underwent a Latarjet or had recurrent dislocations of the shoulder joint. Advanced imaging (CT and/or MRI) was reviewed for glenoid and humeral head bone loss; patients with both glenoid and humeral head bone loss were included in the study. Measurement of the Hill-Sachs lesion (HSL) was standardized prior to the start of the study and measured as described by Di Giacomo. Results: All surgeons completed the review of all 38 images for 2 measurements. Intraobserver reliability was shown to have moderate reliability amongst all reviewers (intraclass correlation coefficient [ICC] = 0.459; p < 0.001). The kappa (κ) value for interobserver reliability amongst all reviewers was moderate for glenoid diameter (ICC = 0.567; 95% CI, 0.474-0.663), moderate for glenoid defect (ICC = 0.61; 95% CI, 0.517-0.702), poor for HSL (ICC = 0.328; 95% CI, 0.232-0.441), moderate for glenoid track (ICC = 0.668; 95% CI, 0.584-0.75) and fair for HSL on- and off-track assessment (κ = 0.267, p < 0.001). Conclusions: The intraobserver reliability of measuring advanced imaging for shoulder instability using the circle line method is overall good; however, the interobserver reliability is moderate to poor.

Preoperative imaging predicts coracoid graft size and restoration of the glenoid track in Latarjet procedures

BackgroundGlenoid bone grafting procedures are often utilized to address glenoid bone loss in patients with recurrent shoulder instability. The purpose of this study was to determine if preoperative advanced imaging can accurately predict coracoid graft size and conversion of off-track to on-track Hill-Sachs lesions in patients undergoing Latarjet procedures. MethodsPatients who underwent Latarjet procedure for shoulder instability at a single institution from 2012-2020 with pre- and postoperative advanced shoulder imaging (computerized tomography (CT) or magnetic resonance imaging (MRI) scans) were retrospectively reviewed. Glenoid diameter, HS interval (HSI), and measurements of the coracoid length, depth, and height were measured on preoperative imaging. Glenoid track (GT), percent glenoid bone loss, predicted restoration of glenoid track, and the difference between HSI and GT (ΔHSI-GT) were calculated. ResultsSeventeen patients with a mean age of 25± 9 years met inclusion criteria. Average glenoid bone loss preoperatively was 24± 7% and average HSI was 27 ± 5mm. The Latarjet procedure reconstructed 116 ± 8% of the native glenoid, and 104 ± 8% of the predicted diameter. Of the 15 patients that had off-track lesions preoperatively, 11 were successfully converted to on-track lesions (73%). The 4 persistent off-track lesions had a significantly higher HSI (32 ± 2 mm vs. 26 ± 4 mm, p=0.002). Preoperative measurements accurately predicted postoperative glenoid track status in 94% of cases. At a mean follow-up of 2 years, there was no significant difference in recurrence rate or rate of revision stabilization procedures between patients with on-track versus persistent off-track humeral lesions. ConclusionPreoperative advanced imaging measurements can accurately predict whether an off-track Hill-Sachs can be converted to on-track after Latarjet procedure, further enhancing shoulder stability.

Shoulder MRI parameters in anticipating anterior shoulder dislocation: Are they a reliable and reproducible tool in clinical practice?

BackgroundAnterior shoulder dislocation (ASD) is a frequently observed musculoskeletal injury that is often encountered in the context of sports activities or as a result of trauma. Several magnetic resonance imaging (MRI) parameters have been previously investigated for the purpose of characterizing the anatomical features, which could potentially be responsible for the episodes of instability. These measurements have the potential to identify patients who are susceptible to dislocation. Consequently, ensuring the reliability and consistency of these measurements is crucial in the diagnosis and the management of athletic or traumatic shoulder injuries. MethodsA group of four students, who had no previous experience in reading MRI series, were selected to perform radiographic measurements on specific parameters of MRI scans. These parameters were glenoid version, glenoid depth, glenoid width, humeral head diameter, humeral containing angle, and the ratio of humeral head diameter to glenoid diameter. The four participants conducted two distinct readings on a total of 28 sets of shoulder MRI scans. Simultaneously, the aforementioned measures were assessed by a consultant shoulder surgeon. ResultsA total of 1512 measurements were categorized into nine sets: eight from students’ measurements (two per student) and one from the consultant. Intra-rater reliability assessed by the intra-class correlation (ICC) test indicated excellent or good reliability for all parameters (p < 0.05), with glenoid depth showing the highest (0.925) and humeral-containing angles the lowest (0.675) ICC value. Inter-rater correlation, also evaluated using ICC, demonstrated strong correlation (p < 0.05), with glenoid diameter having the highest ICC score (0.935) and glenoid depth the lowest (0.849). Agreement analysis, expressed by Cohen's Kappa test, revealed substantial agreement (p < 0.05) for all parameters, with humeral head diameter having the highest agreement (0.90) and humeral-containing angle the lowest (0.73). ConclusionIn this study, intra- and inter-rater MRI parameters are substantially concordant. Credibility comes from these reliability and agreement analyses' statistical significance. Glenoid diameter and depth are the most reliable intrarater and interrater, respectively. Best agreement was with the humeral-containing angle. These data demonstrate repeatability and clinical relevance. Level of EvidenceLevel IV

Effective glenoid track: A novel concept for shoulder instability

BackgroundAssessment and quantification of bone loss in cases of shoulder instability is critical for surgical decision making. The glenoid track concept was initially developed to assess Hill Sachs lesions taking into account the native glenoid diameter of the contralateral shoulder and assessing the degree of glenoid bone loss. However, it can not be reverse calculated to determine the effect of an addition of a bone block. We have developed a novel model to help address this problem yielding an “effective glenoid track” (EGT). MethodsBegin as we always do by using Itoi's concept for assessment of tracking based on the CT scan cuts. Next step is to calucate the Hill Sach's interval (HSI) which will require an MRI scan. ConclusionThe EGT allows for calculation of residual tracking of Hill Sachs lesions post a bone block addition and will aid in surgical decision making.

P258: Does The Latarjet Procedure For Anterior Shoulder Instability Put Off-Track Lesions Back On Track: A Systematic Review

Abstract Introduction The Latarjet procedure is commonly used in the treatment of shoulder instability for high risk patients. The glenoid track is widened by fixing the coracoid to the anterior glenoid. In the presence of bipolar bone loss there is concern that the Latarjet procedure may not adequately address off-track lessions.The aim of this systematic review to assess whether the Latarjet procedure is sufficient to convert 'off-track' Hill-Sachs lesions back to 'on-track'. Methods A systematic review of Pubmed, Embase and the Cochrane Library was performed in October 2023. The primary outcome was the rate of post-operative 'on-track' lesions and of recurrent instability. Changes in glenoid diameter and Hill-Sachs lesion interval were also recorded. Results A total of 5 studies were included with 187 patients. Weighted mean age was 29.2 ± 2.2 years old and 90.8% of patients were male. The mean follow-up time was 26.8 months. All patients had off-track Hill-Sachs lesions pre-operatively. 88.6% of cases were converted to on-track lesions. The overall post-operative instability rate was 4.8%. The recurrence rate was significantly greater for off-track lesions (33.3%) than for on-track lesions (4.2%), odds ratio 11.4 (3.5-37.0). The weighted mean post-operative glenoid diameter change was 8.4 ± 5.8mm. The weighted mean Hill-Sachs lesion interval was 25.6 ± 4.5mm. Conclusion The Latarjet procedure results in the majority of Hill-Sachs lesions being converted to on-track lesions. However, due to bipolar bone loss approximately 1/9 cases will remain off track. In cases of failure to return on-track, there is an unacceptably high rate of recurrent instability (33.3%).

Does glenoid bone loss accompany posterior shoulder instability with only labral tear? A magnetic resonance imaging-based study.

The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear. A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n=40 and n=36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging-based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed. The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P<.01) cases. There was no significant difference (P=.49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P=.04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P=.29). Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

Morphometric analysis of glenoid cavity in adult human scapulae and its clinical importance

Background: The glenoid cavity of scapula is quite small, which allows space for only limited fixation devices. Appropriate fixation of the glenoid component of shoulder is of key importance in total shoulder arthroplasty to prevent loosening, which is a common indication of revision surgery. Orthopedic surgeons and prosthetic designers must have a thorough understanding of the glenoid’s dimensions and shape, in order to create the finest feasible prosthesis. Aims and objectives: To determine the glenoid cavity index (GCI) and the form of the glenoid cavity, as well as the supero-inferior diameter, shortest antero-posterior diameter, and longest antero-posterior diameter. Materials and methods: The study was conducted on 50 dry unpaired adult human scapulae of North Indian population obtained from GMC, Srinagar. All the important morphometric parameters were studied using a vernier calliper. Result: Supero-inferior diameter, shortest antero-posterior diameter, and longest antero-posterior diameter were found to have respective mean values of 35.06 mm, 15.8074 mm, and 23.3814 mm. Glenoid cavity index had a mean value of 66.68. 42% of the glenoid cavities had an inverted comma shape, 36% had a pear shape, and 22% had an oval shape. Conclusion: The results showed that mean supero-inferior diameter of glenoid is about 35mm while the average prosthesis for shoulder arthroplasty in the market starts from 40mm. This suggests that while developing and fitting glenoid components for total shoulder arthroplasty in the North Indian population, it may be necessary to take into account the smaller dimensions of the glenoid cavities.

Magnetic Resonance Imaging Analysis Demonstrates Improved Reliability in Measuring Shoulder Glenoid Bone Loss Using a Two-Thirds Glenoid Height Technique Compared to the “Best-fit Circle”

To evaluate the superior to inferior glenoid height as a reliable reference in best-fit circle creation for glenoid anatomy. The morphology of the native glenoid was evaluated using magnetic resonance imaging (MRI) in patients without shoulder instability. Using T1 sagittal MRI images, two reviewers independently estimated glenoid size using the two-thirds technique and the "best-fit circle" technique at two different times. A student's t-test was used to determine significant difference between the two methodologies. Inter- and intra-rater reliability were calculated using interclass and intraclass coefficients. This study included 112 patients. Using the results of glenoid height and "best-fit circle" diameter, the diameter of the "best-fit circle" was found to intersect the glenoid line at 67.8% of the glenoid height on average. We found no significant difference between the two measures of glenoid diameter (27.6 vs 27.9, p =.456). The interclass and intraclass coefficients for the two-third method were 0.85 and 0.88, respectively. The inter-class and intra-class coefficients for the perfect circle methods were 0.84 and 0.73, respectively. We determined that the diameter of a circle placed on the inferior glenoid using the 'best-fit circle' technique corresponds to 67.8% of the glenoid height. Additionally, we found that constructing a perfect circle using a diameter equal to two-thirds the height of the glenoid may improve intra-class reliability.

CT methods for measuring glenoid bone loss are inaccurate, and not reproducible or interchangeable.

Glenoid bone loss is a significant problem in the management of shoulder instability. The threshold at which the bone loss is considered "critical" requiring bony reconstruction has steadily dropped and is now approximately 15%. This necessitates accurate measurement in order that the correct operation is performed. CT scanning is the most commonly used modality and there are a number of techniques described to measure the bone loss however few have been validated. The aim of this study was to assess the accuracy of the most commonly used techniques for measuring glenoid bone loss on CT. Anatomically accurate models with known glenoid diameter and degree of bone loss were used to determine the mathematical and statistical accuracy of six of the most commonly described techniques (relative diameter, linear ipsilateral circle of best fit (COBF), linear contralateral COBF, Pico, Sugaya, and circle line methods). The models were prepared at 13.8%, 17.6%, and 22.9% bone loss. Sequential CT scans were taken and randomized. Blinded reviewers made repeated measurements using the different techniques with a threshold for theoretical bone grafting set at 15%. At 13.8%, only the Pico technique measured under the threshold. At 17.6% and 22.9% bone loss all techniques measured above the threshold. The Pico technique was 97.1% accurate, but had a high false-negative rate and poor sensitivity underestimating the need for grafting. The Sugaya technique had 100% specificity but 25% of the measurements were incorrectly above the threshold. A contralateral COBF underestimates the area by 16% and the diameter by 5 to 7%. No one method stands out as being truly accurate and clinicians need to be aware of the limitations of their chosen technique. They are not interchangeable, and caution must be used when reading the literature as comparisons are not reliable.

The Glenoid Fossa's Morphometric Investigation and Its Clinical Implications.

Background The inconsistent morphology of the scapula is based on variable dimensions of its glenoid cavity, in addition to its broadened and truncated lateral angle. Its variable shapes are attributed to the spinoglenoid cavity (superior and posterior aspect of thescapula), which appears oval, inverted comma-shaped, and piriform (pear-shaped).Traumatic conditions often lead to glenoid dislocation/fracture. The precise administration of total shoulder arthroplasty with glenoid component adjustment warrants a comprehensive knowledge of scapular morphology. This study aims to assess the glenoid cavity/scapula shapes (anthropometric assessment) among individualslocated in Odisha, India. Methods This cross-sectional analysis was undertaken on 74 left-sided and 70 right-sided, dry, and undeteriorated scapulae of human adult specimens obtained from the anatomy department irrespective of their gender and age. Results The glenoid cavity was most commonly inverted comma-shaped (34.02%) and pear-shaped (48.61%) while 17.36% of scapulae had oval-shaped glenoid cavities. The mean scapular breadth and length dimensions were 98.12±7.87mm and 135.76±12.85mm, respectively. Statistically insignificant bilateral variations were observed between the glenoid cavity index (mean value: 68.44±7.98%), glenoid diameter-2 (anteroposterior; mean value: 16.17±2.24mm), glenoid diameter-1 (anteroposterior; mean value: 22.67±1.53mm), and glenoid diameter (superoinferior; mean value: 36.03±2.15mm). Conclusion The size and shape of the glenoid cavity are directly associated with the dislocation of the shoulder joint and may disturb the results of total shoulder arthroplasty and rotator cuff surgeries. The current study analyzed the morphological types and diameters of the glenoid cavity in the scapulae to improve efficiency and lessen the failure proportions in shoulder arthroplasty. The study shows that morphological measurement of scapulae plays a vital role in the effective maintenance of posture and shoulder functions.

Morphological classification and measurement of the glenoid cavity using three-dimensional reconstruction in a Chinese population.

The purpose of this study was to examine the various shapes and record the morphometric data of the glenoid cavity in a Chinese population. A total of 501 scapulae, 247 left and 254 right, were analysed. We classified the shape of the glenoid cavity as type I (pear-shaped), type II (oval-shaped), type III (teardrop-shaped), type IV (calabash-shaped) or type V (inverted comma-shaped). Four defined parameters, the superior-inferior glenoid diameter (AB), upper anterior-posterior glenoid diameter (CD), lower anterior-posterior glenoid diameter (EF) and glenoid index (GI), were measured, and five shapes were classified via three-dimensional reconstruction. The mean AB, CD, EF and GI values of the glenoid were 3.51 ± 0.41 cm, 1.95 ± 0.28 cm, 2.60 ± 0.34 cm, and 1.35 ± 0.12 cm, respectively. The AB value of type II glenoid cavities was significantly smaller than that of type I and III glenoid cavities (p < 0.05), but the GI value of type II glenoid cavities was larger than that of type III cavities (p < 0.05). The CD value showed a difference between type I and type III glenoid cavities (p < 0.05). For the EF parameter, the values of type III glenoid cavities were significantly larger than those of type I and II glenoid cavities (p < 0.05). Measuring and observing the variety of shapes and sizes of the glenoid cavity in Chinese people is conducive to for better understand its morphological features. This information can also guide surgeons in the design and selection of suitable prostheses for total shoulder arthroplasty in the Chinese population in order to reduce postoperative complications.

Average Indian Glenoid Sizes Are Smaller than All Commercially Available Glenoid Components: A Systematic Review.

Despite the variability in glenoid sizes geographically, most of the currently available commercial glenoid component designs are based on the glenoid parameters of the Caucasian population which may not be suitable for the Indian population due to a mismatch between the prosthesis and native anatomy. The aim of the present study is to systematically review the literature to determine the average glenoid anthropometric parameters in the Indian population. A comprehensive literature search was conducted using preferred reporting items for systematic reviews and meta-analyses guidelines in the PubMed, EMBASE, Google Scholar, and Cochrane Library databases from the date of inception to May 2021. Any observational study conducted on the Indian population measuring the glenoid diameters, glenoid index, version, inclination, or any other glenoid measurements were included in the review. A total of 38 studies were included in this review. The glenoid parameters were assessed on intact cadaveric scapulae in 33 studies, on 3DCT in three studies, and 2DCT in one study. The pooled average of glenoid dimensions are as the following- the superoinferior diameter or height was 34.65mm, anteroposterior1 diameter or maximum width was 23.72mm, anteroposterior2 diameter or maximum width of the upper part of the glenoid was 17.05mm, the glenoid index was 67.88, and the glenoid version was 1.75-degree retroversion. Males were having a mean height of 3.65mm and maximum width of 2.74mm larger than the females. A subgroup analysis revealed no significant difference between different parts of India in glenoid parameters. The glenoid dimensions in the Indian population are smaller compared to the average European and American populations. The average glenoid maximum width of the Indian population is 1.3mm smaller than the minimum glenoid baseplate size available in reverse shoulder arthroplasty. Glenoid components specific to the Indian market need to be designed to reduce glenoid failure attributable to the above findings. III.

Does preoperative glenoid bony defect determine final coracoid graft positioning in arthroscopic Latarjet?

It has been demonstrated that the accurate positioning of the graft is key to restoring shoulder stability and preventing future arthrosis development. Preoperative anteroinferior glenoid bone loss is frequently encountered when performing a Latarjet, and it has not been determined yet if the amount of bony defect can influence graft positioning. The aim of the study was to determine if a preoperative glenoid bony defect has an influence on the final coracoid graft position in the arthroscopic Latarjet procedure. Fifty-five patients who underwent the arthroscopic Latarjet procedure were included, with a minimum follow-up of 2 years. There were 51 men (92.7%). Mean age was 29.1 (SD 7.63). Western Ontario Shoulder Instability Index, Rowe, and Single Assessment Numeric Evaluation scores were fulfilled. All measurements were performed by a musculoskeletal radiologist based on a multiplanar bidimensional CT scan. Dimensions of the glenoid, glenoid defect, and glenoid track were calculated. Position of the graft was evaluated in the axial (distance to glenoid surface, angulation of the graft and screws) and sagittal planes (percentage of the coracoid graft below the equator) as described by Kany etal and Barth etal respectively. There was a glenoid defect in 41 patients (74.5 %). Mean width of the defect was 4.32 mm (SD 3.08) which represented 15.3% of the native glenoid surface (SD 10.8). 78.2% of the patients were offtrack preoperatively, and 11.9% remained offtrack postoperatively. The final glenoid diameter with the graft was 32.1 mm (SD 4.34). Mean distance from the graft to the glenoid at 50% height was 1.1 mm (SD 2.19 mm) and at 25% height was 1.31 mm (SD 2.05). Mean angulation of the superior and inferior screws were 26.9° (SD 8.2°) and 27.1° (SD 7.35°), respectively. In 81.8% of the cases, the graft was deemed to be flush with the glenoid. The percentage of the coracoid graft under the equator of the glenoid was 71.2 % (SD 21.8). There was not a statistically significant difference in screw angulation or graft positioning in the axial plane when comparing patients who had a glenoid defect with those who did not, or depending on the size (P>.05). Percentage of graft below the equator was, however, lower in patients without bony defect (P=.04). This study showed that accurate position of the coracoid graft is achieved in the presence of a glenoid bony defect. In the cases of intact glenoid, the height of the graft should be carefully evaluated.

Surgeon-designed patient-specific instrumentation improves glenoid component screw placement for reverse total shoulder arthroplasty in a population with small glenoid dimensions

PurposeGlenoid component loosening is a potential complication of reverse total shoulder arthroplasty (rTSA), occurring in part due to lack of adequate screw purchase in quality scapular bone stock. This study was to determine the efficacy of a surgeon-designed, 3D-printed patient-specific instrumentation (PSI) compared to conventional instrumentation (CI) in achieving longer superior and inferior screw lengths for glenoid component fixation.MethodsA multi-centre retrospective analysis of patients who underwent rTSA between 2015 and 2020. Lengths of the superior and inferior locking screws inserted for fixation of the glenoid baseplate component were recorded and compared according to whether patients received PSI or CI. Secondary outcomes included operative duration and incidence of complications requiring revision surgery.ResultsSeventy-three patients (31 PSI vs. 42 CI) were analysed. Average glenoid diameter was 24.5 mm (SD: 3.1) and 81% of patients had smaller glenoid dimensions compared to the baseplate itself. PSI produced significantly longer superior (44.7 vs. 30.7 mm; P < 0.001) and inferior (43.0 vs. 31 mm; P < 0.001) mean screw lengths, as compared to CI. A greater proportion of maximal screw lengths for the given rTSA construct (48 mm) were observed in the PSI group (71.9% vs. 11.9% superior, 59.4% vs. 11.9% inferior). Operative duration was not statistically significantly different between the PSI and CI groups (150 min vs. 169 min, respectively; P = 0.229). No patients had radiographic loosening of the glenoid component with an average of 2-year follow-up.ConclusionPSI facilitates longer superior and inferior screw placement in the fixation of the glenoid component for rTSA. With sufficient training, PSI can be designed and implemented by surgeons themselves.

MORPHOLOGICAL MEASURES OF SCAPULA IN SOUTH INDIAN POPULATION USING CT

Introduction: An immense knowledge about the shape of the glenoid cavity is necessary for TSA. This study aims to evaluate the dimension of the glenoid cavity and to compare the morphological measures of scapula between genders. Materials and methods: A total of 32 males and 32 females were selected for the shoulder scan and the measurements were taken in 2D axial plane and 3D reconstructed images. Statistical analysis was done using SPSS Version 21.0. [Formula: see text] 0.05 was taken as significant. Result: Out of five diameters that we considered in this study, the superior–inferior (SI) mean glenoid diameter is 33.09 ± 3.82 mm. The anterior–posterior average glenoid diameters AP1, AP2, AP3 and AP4 are 15.08 ± 3.03 mm, 18.12 ± 3.26 mm, 21.03 ± 2.41 mm, 22.1 ± 2.54 mm, respectively, in total population. Six angles were considered, the Axis of glenoid, Axis of scapula, Axis of humeral head, axis of the glenoid neck, Resch angle and version of glenoid, measured 132.51[Formula: see text]± 5.46[Formula: see text], 43.03[Formula: see text]± 5.04[Formula: see text], 132.44[Formula: see text]± 5.04[Formula: see text], 58.48[Formula: see text]± 6.42[Formula: see text], 72.92[Formula: see text]± 4.79[Formula: see text], − 5.21[Formula: see text]± 1.45[Formula: see text], respectively, for the total population. The specific cut-off points for SI, AP1, AP2, AP3 and AP4 are 35, 15.35, 18.1, 21.55 and 22.65, respectively. Conclusion: The morphological measures such as Axis of glenoid, Axis of humeral head, Resch angle and Axis of scapula show that there exists a statistically significant difference between two genders. Hence, these four measures have a vital role in gender identification of an unknown scapula. All the diameters in this study have got specific cut-off points and it will be most useful to discriminate the gender from an unknown scapula.

Glenoid Morphology and Related Parameters in Turkish Society.

IntroductionGlenoid morphology may vary in different ethnic groups. Detection of these differences may be important in preoperative planning, especially in reverse shoulder arthroplasty. In this study, we investigated the mean glenoid size and retroversion in Turkish society and their relationship with the dominant side, gender, height, weight, and body mass index (BMI).Materials and methodsBetween 2019 and 2021, 102 shoulders of 51 patients (24 females/27 males, 51 left/51 right) who were included in shoulder joint imaging during thorax CT scanning were examined. Those with glenoid fracture, arthrosis, shoulder surgery or deformity, or younger than 18 years of age were not included in the study. The mean age was 41.69 (range: 18-73) years. Glenoid anterior-posterior diameter (D) and glenoid version (GV) were measured in axial slices, and glenoid height (H) was measured in coronal slices. The correlation of these parameters with gender, height, weight, and dominant side was examined.ResultsMean D was 25.79±4.44 mm, mean H was 29.08±4.08 mm, and mean GV was -0.99°±0.92°. The mean height of the patients was 162±16.23 cm and the mean weight was 71.9±15.36 kg. The glenoid diameter and height were smaller in females, however, no statistically significant difference was found in the glenoid version (p<0.01, p<0.01, and p=0.92). The glenoid on the dominant side was statistically significantly more retroverted, whereas D and H were not associated with dominance (p<0.01, p=0.9, and p=0.98). It was found that the glenoid sizes were very highly correlated with the patient's height, and it was highly correlated with the patient's weight (p<0.01 and p<0.01). On the other hand, height and weight were not correlated with the glenoid version (p=0.47 and p=0.81, respectively). There was no statistically significant relationship between BMI and glenoid sizes and glenoid version (p=0.14 and p=0.46, respectively).ConclusionsFemales in Turkish society had small glenoid sizes. Male gender, height, and weight were positively correlated with large glenoids. The glenoid was more retroverted on the dominant side. These findings should be considered in preoperative planning in Turkish society.

Poster 170: Preoperative Advanced Imaging Predicts Coracoid Graft Size and Restoration of the Glenoid Track in Patients Undergoing Latarjet Procedures

Objectives:The Latarjet procedure is commonly used in management of anterior shoulder instability with bipolar bone deficiency. Persistent off-track Hill-Sachs (HS) lesions after Latarjet procedure is associated with significantly higher rates of failure and recurrent instability. Preoperative prediction of which lesions will remain off-track is crucial for improving outcomes and decreasing failure rates. The purpose of this study was to determine if preoperative advanced imaging can predict coracoid graft size and conversion of off-track to on-track Hill-Sachs lesions in patients undergoing Latarjet procedures.Methods:Patients who underwent Latarjet procedure for shoulder instability at a single institution from 2012-2020 were evaluated. Inclusion criteria consisted of pre- and post-operative advanced imaging - computerized topography or magnetic resonance imaging. Glenoid diameter, HS interval (HSI), and coracoid length, depth, and height were measured on preoperative imaging. Glenoid track (GT), percent glenoid bone loss, predicted restoration of glenoid track, and the difference between HSI and GT (DHSI-GT) were calculated. These values were then compared with postoperative measurements of the glenoid diameter and coracoid graft width and height.Results:Seventeen patients with a mean age of 24.6 ± 8.6 years met inclusion criteria. The average glenoid bone loss preoperatively was 23.6 ± 7.3% and the average HSI was 27.2 ± 4.9mm. The Latarjet procedure was able to reconstruct 115.8 ± 7.6% of the native glenoid, and 103.8 ± 7.9% of the predicted diameter. Of the 15 patients that had off-track lesions preoperatively, 11 were successfully converted to on-track lesions (73.3%). The 4 lesions that remained off-track postoperatively had a significantly higher HSI (32.4 ± 2.4 mm vs. 25.6 ± 4.3 mm, p=0.002) and 3 of these had insufficient coracoid graft to convert to an on-track lesion based on the preoperative DHSI-GT values in comparison to coracoid graft size. Preoperative measurements accurately predicted postoperative glenoid track status 94.1% of cases.Conclusions:The Latarjet procedure was able to reconstruct 115.8 ± 7.6% of the native glenoid and converted 73.3% of off-track lesions to on-track lesions. The glenoid was reconstructed to 103.8 ± 7.9% of the predicted diameter. Preoperative advanced imaging measurements accurately predicted graft size, restoration of the glenoid track, and ability to convert off-track to on-track lesions.

Glenoid bony morphology along long diameter is associated with the occurrence of recurrent anterior shoulder dislocation: a case-control study based on three-dimensional CT measurements.

The purpose of our study is to compare the anatomic parameters of proximal humerus, glenoid, and glenohumeral joint between patients with recurrent anterior shoulder dislocation (RASD) and patients without RASD with the assistance of three-dimensional (3D) CT scans. Sixty patients were included in the study and divided into group RASD and group control. 3D-CT models of shoulder joint for each included patient were reconstructed and multiple anatomic parameters were measured. There were no statistically significant differences between the two groups in morphological parameters of humerus and glenohumeral joints. Long diameter of glenoid was 3.50 ± 0.34cm for patients in group RASD and 3.31 ± 0.32cm in group control (p = 0.039). There was a statistically significant difference in the ratio of long to short diameter of glenoid (p < 0.001). Ratio of humeral head height to glenoid long diameter (Hhh/Gld) was 1.02 ± 0.07 in group RASD, significantly lower than 1.09 ± 0.08 in group control (p = 0.001). Longitudinal depth of glenoid was significantly higher in group RASD (p = 0.013). The glenoid morphology along long diameter is closely correlated with the stability of glenohumeral joint, including glenoid long diameter and glenoid longitudinal depth. It is especially noteworthy that the value of Hhh/Gld decreases in patients with RASD. The difference of Hhh/Gld between the two groups reminds us that the correlation of bony structure along long diameter between glenoid and humeral head plays an important role in RASD.