Prediction of coracoid thickness using a glenoid width-based model: implications for bone reconstruction procedures in chronic anterior shoulder instability

Outcomes of the Latarjet procedure in female patients: A case series and matched-pair analysis

Background

The objective of this study was to retrospectively report on the outcomes of female patients undergoing the Latarjet procedure.

Methods

Female patients undergoing the Latarjet procedure with minimum 1 year follow-up were identified and contacted to obtain Numeric Pain Rating Scale (NPRS), Subjective Shoulder Value (SSV), and return to sport (RTS) data. Eligible females were then matched 1:1 with a male counterpart based on laterality and age (± 3 years), and outcomes compared.

Results

A total of 20 female patients with a mean follow-up of 73.8 months reported postoperative NPRS and SSV scores of 2.2  ±  2.3 and 69.3  ±  22.0, respectively. Of the nine athletes, 3 (33%) reported a successful RTS at a mean of 9 months. Four patients (20.0%) required reoperation at a mean of 27.1 months. The matched analysis demonstrated similar NPRS scores between male and female patients and a trend towards lower SSV scores and rates of RTS.

Conclusion

At mid-term follow-up female patients reported pain levels similar to female-specific literature reports, but overall low subjective shoulder function and RTS. Compared to propensity-matched males, females reported similar levels of pain, lower shoulder function, and lower rates of RTS, however, differences did not reach statistical significance.

Level of Evidence

IV, retrospective case series.

Size and morphology of the coracoid and glenoid in pediatric and adolescent patients: implications for Latarjet procedure

Background

Glenohumeral instability is a challenging problem in children and adolescents. For patients with anterior glenoid bone loss, the Latarjet procedure is an effective treatment option. However, concerns about coracoid size and morphology may limit its utilization within this patient population. The purpose of this study was to establish normative data on coracoid and glenoid size and morphology among a large cohort of adolescent patients and describe the anatomic relationships with demographic factors.

Methods

This is a retrospective cross-sectional study of a consecutive series of 584 patients aged 12-21 years after a chest computed tomography scan for non-shoulder related trauma at a single level I trauma center. Demographic characteristics were collected from the electronic medical record, and the following coracoid anatomic measurements were obtained from computed tomography scans: coracoid length, coracoid thickness, coracoid width, glenoid height, and glenoid width. The ratio of coracoid thickness to glenoid width was calculated to estimate the percent bone loss that could be addressed with a traditional Latarjet coracoid transfer. To ensure reliability among 3 reviewers, all measured the same 25 scans and inter-rater reliability was excellent with all Kappa coefficients >0.81. The remaining scans were divided equally and assessed separately by these reviewers. Correlation coefficients were used to quantify the relationships between all anatomic measures and the age, weight, and height of individuals. Growth curves for each measurement were modeled using quantile regression with height and height∗height as predictors. Additionally, we stratified the growth curves by sex, when significant. Of the 584 subjects, 55% were male, and average age was 19 years (range 12, 21).

Results

All growth curves illustrated increase anatomic size across the height range of 145-190 cm. The growth curve including all patients (Fig. 1) illustrated that the 50% percentile of median coracoid length increased from approximately 28 to 32 mm. In addition to height, sex was a significant predictor for coracoid width and glenoid width. The median coracoid width increased from approximately 9.5 to 10.2 mm for females compared to an increased width from approximately 10 to 11 mm for males. The median glenoid width for females increased from approximately 21 to 25 mm and for males the median glenoid width increased from just under 22 to 25.5 mm.

Conclusions

Among children and adolescents, coracoid and glenoid size are correlated with patient height. These data can help guide patient selection for the Latarjet procedure.

Clinical Outcomes of the Traditional Latarjet Versus the Congruent Arc Modification for the Treatment of Recurrent Anterior Shoulder Instability: A Meta-analysis

Background:

Few studies have compared clinical outcomes between the traditional Latarjet procedure for anterior shoulder instability and the congruent arc modification to the Latarjet procedure.

Purpose:

To systematically evaluate the literature for the incidence of recurrent instability, clinical outcomes, radiographic findings, and complications for the traditional Latarjet procedure and the congruent arc modification and to compare results of each search.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review and meta-analysis was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. We included studies published between January 1990 and October 2020 that described clinical outcomes of the traditional Latarjet and the congruent arc modification with a follow-up range of 2 to 10 years. The difference in surgical technique was analyzed using a chi-square test for categorical variables, while continuous variables were evaluated using a Student t test.

Results:

In total, 26 studies met the inclusion criteria: 20 studies describing the traditional Latarjet procedure in 1412 shoulders, and 6 studies describing the congruent arc modification in 289 shoulders. No difference between procedures was found regarding patient age at surgery, follow-up time, Rowe or postoperative visual analog scores, early or late complications, return-to-sport timing, or incidence of improper graft placement or graft fracture. A significantly greater proportion of male patients underwent glenoid augmentation using the congruent arc modification versus traditional Latarjet (P < .001). When comparing outcomes, the traditional Latarjet procedure demonstrated a lower incidence of fibrous union or nonunion (P = .047) and broken, loose, or improperly placed screws (P < .001), and the congruent arc modification demonstrated improved outcomes with regard to overall return to sport (P < .001), return to sport at the same level (P < .001), incidence of subluxation (P = .003) or positive apprehension (P = .002), and revision surgery for recurrent instability (P = .027).

Conclusion:

Outcomes after the congruent arc modification proved at least equivalent to the traditional Latarjet procedure in terms of recurrent instability and return to sport, although early and late complications were equivalent. The congruent arc procedure may be an acceptable alternative to traditional Latarjet for the treatment of anterior shoulder instability with glenoid bone loss; however, long-term outcomes of this procedure are needed.

Analysis of the coracoid morphology with multiplanar 2D CT and its effects on the graft size in the Latarjet procedure

PURPOSE

In this study, we aimed to reveal the individual differences regarding the size of the coracoid and their effects on the classical and modified Latarjet procedures.

METHODS

Computed tomography images of 120 patients (mean age: 41.18 ± 12.01 years) without shoulder complaints or shoulder instability were evaluated retrospectively. The glenoid width, the surgical graft length, and the coracoid total length, width, and thickness were measured using the multiplanar reconstruction method on the Sectra Picture Archiving and Communications System (PACS) system. Age, gender, side, the dominant hand, and the height of the patients were recorded and the correlations between them were investigated. On the created hypothetical model, the current size of the coracoid was evaluated to determine what size of glenoid defects it could repair by employing the classical and the modified Latarjet techniques.

RESULTS

There was no significant difference between the right-hand-dominant group and the left-hand-dominant group in terms of coracoid measurement results (p > 0.05). Again, there was no statistically significant difference between the right and the left side regarding the coracoid size (p > 0.05). A positive correlation could be detected only between age and the coracoid width and thickness (p < 0.05). A positive correlation was also found between the glenoid width and the coracoid width and thickness in both shoulders (p < 0.001). Coracoid thickness could fill in the defects that amounted to 40% of the glenoid width, while the coracoid width could fill in for the defects that were 50% of the glenoid width in both genders.

CONCLUSION

Our study showed that hand dominance and side were not effective on the coracoid dimensions. In addition, it has been shown that the coracoid dimensions did not have a significant effect in the choice of Latarjet technique in terms of defect repair and that repair rates of up to 40% could be achieved in glenoid defects with both techniques.

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.

Clinical Outcomes of Shoulder Stabilization in Females With Glenoid Bone Loss

Background

Nearly all studies describing shoulder stabilization focus on male patients. Little is known regarding the clinical outcomes of female patients undergoing shoulder stabilization, and even less is understood about females with glenoid bone loss.

Purpose

To assess the clinical outcomes of female patients with recurrent anterior shoulder instability treated with the Latarjet procedure.

Study Design

Case series; Level of evidence, 4.

Methods

All cases of female patients who had recurrent anterior shoulder instability with ≥15% anterior glenoid bone loss and underwent the Latarjet procedure were analyzed. Patients were evaluated after a minimum 2-year postoperative period with scores of the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale.

Results

Of the 22 patients who met our criteria, 5 (22.7%) were lost to follow-up, leaving 17 (77.2%) available for follow-up with a mean ± SD age of 31.7 ± 12.9 years. Among these patients, 16 (94.1%) underwent 1.6 ± 0.73 ipsilateral shoulder operations (range, 1-3) before undergoing the Latarjet procedure. Preoperative indications for surgery included recurrent instability with bone loss in all cases. After a mean follow-up of 40.2 ± 22.9 months, patients experienced significant score improvements in the American Shoulder and Elbow Surgeons form, Simple Shoulder Test, and pain visual analog scale (P < .05 for all). There were 2 reoperations (11.8%). There were no cases of neurovascular injuries or other complications.

Conclusion

Female patients with recurrent shoulder instability with glenoid bone loss can be successfully treated with the Latarjet procedure, with outcomes similar to those of male patients in the previously published literature. This information can be used to counsel female patients with recurrent instability with significant anterior glenoid bone loss.

Risk Factors for Recurrent Anterior Glenohumeral Instability and Clinical Failure Following Primary Latarjet Procedures: An Analysis of 344 Patients

BACKGROUND

Patients with a greater risk of recurrent instability and inferior clinical outcomes following a primary Latarjet procedure can be preoperatively identified on the basis of clinical, radiographic, and demographic criteria. The purpose of this study was to identify risk factors influencing the rates of recurrent anterior glenohumeral instability and clinical failure following a primary Latarjet procedure.

METHODS

All patients who underwent a primary Latarjet procedure were prospectively enrolled and evaluated. The Western Ontario Shoulder Instability Index (WOSI) and Single Assessment Numeric Evaluation (SANE) outcome scores were collected at a minimum 5-year follow-up along with evidence of recurrent instability. Recurrent instability (recurrent subluxation or dislocation) was considered as a failure. Clinical failure was defined as a postoperative WOSI score of ≥630 points (≤70% normal) or a SANE score of ≤70 points.

RESULTS

From 2004 to 2014, 344 patients (358 shoulders) with a mean age of 30.6 years (range, 16 to 68 years) were enrolled and had a mean follow-up time of 75 months (range, 61 to 89 months). The median postoperative WOSI score was 265 points (range, 0 to 1,100 points), and the median SANE score was 88 points (range, 50 to 100 points). Recurrence occurred in 17 shoulders (4.7%), 5 with dislocation and 12 with subluxation; and 28 (8.2%) of 341 shoulders without recurrent instability were clinical failures following a Latarjet procedure. The risk factors for recurrence included atraumatic dislocation (odds ratio [OR], 4.6; p < 0.01) and bilateral instability (OR, 4.0; p = 0.01), whereas the risk factors for clinical failure (WOSI score of ≥630 points or SANE score of ≤70 points) were female sex (OR, 2.8; p < 0.01) and bilateral instability (OR, 4.6; p = 0.01).

CONCLUSIONS

Outcomes at a mean of >6 years following a primary Latarjet procedure for anterior shoulder instability were very good, with an overall recurrence rate of 4.7%. An additional 8.2% of cases were defined as clinical failures. Patients with an atraumatic mechanism of primary dislocation, bilateral instability, and female sex were identified to be at a greater risk of recurrence or clinical failure. Although additional work is necessary, patients with capsuloligamentous laxity, relatively atraumatic instability history, bilateral instability, and female sex may be preoperatively identified as having a higher risk of treatment failure after a primary Latarjet procedure.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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.

Return to Sport After Coracoid Transfer in Athletes With Anterior Shoulder Instability: A Systematic Review

CONTEXT

Recurrent shoulder instability in young athletes can lead to a spectrum of soft tissue and bony lesions that can be bothersome and/or disabling. Coracoid transfer is a treatment option for athletes with recurrent instability.

OBJECTIVE

To report the rate of return to sport for athletes after coracoid transfer.

DATA SOURCES

An electronic search of the literature was performed using the PubMed (MEDLINE) and Cochrane Databases (1966-2018).

STUDY SELECTION

Studies were included if they evaluated return to sport after treatment with coracoid transfer at a minimum 1-year follow-up.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Data were extracted by 2 authors and included study design, level of evidence, patient demographics (number, age, sex), procedure performed, duration of clinical follow-up, rate of return to sport, patient-reported outcome measures, reoperations, and complications.

RESULTS

Fourteen studies met the inclusion criteria. The rate of return to sport at any level ranged from 80% to 100% in all but 1 study (38%), and the rate of return to the previous level of play ranged from 56% to 95% in all but 1 study (16%). Patients returned to sport at an average of 3.2 to 8.1 months. The average patient-reported outcome scores ranged from 78% to 94% (Rowe), 223.6 to 534.3 (Western Ontario Shoulder Instability Index), and 75% to 90% (subjective shoulder value). The rate of postoperative dislocation ranged from 0% to 14%, and the reoperation rate ranged from 1.4% to 13%.

CONCLUSION

There was a high early rate of return to sport in patients who underwent coracoid transfer for anterior shoulder instability, although patients did not reliably return to the same level of play. The procedure had very favorable outcomes for treatment of instability, with low rates of recurrent dislocation and reoperation.

Neer Award 2019: Latarjet procedure vs. iliac crest bone graft transfer for treatment of anterior shoulder instability with glenoid bone loss: a prospective randomized trial

BACKGROUND

The Latarjet and iliac crest bone graft transfer (ICBGT) procedures are competing treatment options for anterior shoulder instability with glenoid bone loss.

METHODS

In this bicentric prospective randomized study, 60 patients with anterior shoulder instability and glenoid bone loss were included and randomized to either an open Latarjet or open ICBGT (J-bone graft) procedure. Clinical evaluation was completed before surgery and 6, 12, and 24 months after surgery, including the Western Ontario Shoulder Instability index, Rowe score, Subjective Shoulder Value, pain level, satisfaction level, and work and sports impairment, as well as assessment of instability, range of motion, and strength. Adverse events were prospectively recorded. Radiographic evaluation included preoperative, postoperative, and follow-up computed tomography analysis.

RESULTS

None of the clinical scores showed a significant difference between the 2 groups (P > .05). Strength and range of motion showed no significant differences except for diminished internal rotation capacity in the Latarjet group at every follow-up time point (P < .05). A single postoperative traumatic subluxation event occurred in 2 ICBGT patients and 1 Latarjet patient. The type and severity of other adverse events were heterogeneous. Donor-site sensory disturbances were observed in 27% of the ICBGT patients. Computed tomography scans revealed a larger glenoid augmentation effect of the ICBGTs; this, however, was attenuated at follow-up.

CONCLUSION

The Latarjet and ICBGT procedures for the treatment of anterior shoulder instability with glenoid bone loss showed no difference in clinical and radiologic outcomes except for significantly worse internal rotation capacity in the Latarjet group and frequently noted donor-site sensory disturbances in the ICBGT group.

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.

Differences in Coracoid and Glenoid Dimensions Based on Sex, Race, and Age: Implications for Use of the Latarjet Technique in Glenoid Reconstruction

BACKGROUND

The Latarjet procedure restores shoulder stability through reconstruction of the glenoid arc. Prior investigations of glenoid and coracoid dimensions have been underpowered to detect differences based on sex and race.

QUESTIONS/PURPOSES

We sought to establish normative values for glenoid width and coracoid dimensions based on sex, race, and age. In addition, we assessed the restoration of glenoid dimensions using the classic and modified Latarjet techniques (classic technique: placing lateral surface of the coracoid to the glenoid; modified technique: placing inferior surface of the coracoid to the glenoid).

METHODS

A total of 993 cadaveric specimens (n = 1986 scapulae) from people over 18 years of age at the time of death were analyzed. Measurements of maximal glenoid width, coracoid width, thickness, and length were recorded. Statistical analysis was performed to detect differences based on sex and race, while univariable linear regression was used to determine the association of increasing age on measured dimensions.

RESULTS

All dimensions of specimens were significantly larger in males than in females. Caucasians possessed larger mean glenoid width, coracoid width, and coracoid length, while coracoid thickness was significantly larger in African Americans. Linear regression analysis found that increasing age was associated with increased glenoid width and coracoid dimensions. Coracoid positioning restored glenoid width in defects measuring 20% of glenoid width using both classic and modified Latarjet techniques, while defects measuring up to 25% were more accurately reproduced using the modified technique.

CONCLUSION

Dimensions were significantly larger in males and in Caucasians, aside from coracoid thickness. Mean dimensions increased with advancing age. Coracoid positioning using classic or modified Latarjet techniques restored glenoid width defects measuring 20% of the glenoid width, while the modified technique allowed for restoration of larger defects.

Does the Arthroscopic Latarjet Procedure Effectively Correct "Off-Track" Hill-Sachs Lesions?

BACKGROUND

The glenoid track concept describes the dynamic interaction of bipolar bone loss in anterior glenohumeral instability. Initial studies have successfully demonstrated this concept's application in clinical populations. In clinical practice, the Latarjet procedure is commonly the preferred treatment in addressing "off-track" Hill-Sachs lesions. The effectiveness of this procedure in restoring such lesions to an "on-track" state, however, has not yet been evaluated or described in the literature.

HYPOTHESIS

The Latarjet procedure would transform "off-track" Hill-Sachs lesions to "on-track" lesions. Lesions would remain "on-track" during follow-up, despite glenoid remodeling.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients with "off-track" Hill-Sachs lesions treated with the arthroscopic Latarjet procedure between March 2013 and May 2014 were included. Glenoid track and coracoid graft contact surface area measurements using 3-dimensional computed tomography (3D-CT) were performed preoperatively and at 6-week, 6-month, and at least 12-month (final) follow-up. The mean final follow-up was 23 months. The glenoid diameter, as a percentage of the native glenoid, was also calculated from this imaging.

RESULTS

Twenty-six patients met the inclusion criteria. 3D-CT scans were available for all patients preoperatively and postoperatively, with 21 patients (81%) undergoing 6-month follow-up CT and 19 patients (73%) undergoing final follow-up CT. Hill-Sachs lesions remained "on-track" at all follow-up time points. The mean glenoid diameter changed significantly from 84.6% preoperatively to 122.8% at 6 weeks ( P < .001) and from 120.5% at 6 months to 113.9% at final follow-up ( P = .005). This was also reflected in significant remodeling seen in the coracoid graft articular contact area (6 weeks to 6 months, P = .024; 6 months to final follow-up, P = .002). This persisting glenoid arc enlargement at final follow-up avoided "off-track" Hill-Sachs lesions in 6 of 19 patients (32%), which would otherwise have occurred had the coracoid graft remodeled to native glenoid dimensions.

CONCLUSION

The Latarjet procedure provides an effective treatment for "off-track" engaging Hill-Sachs lesions, despite an evident glenoid remodeling process. At a mean of 23 months postoperatively, a mean persisting enlargement of the glenoid arc of 14% beyond native dimensions remained, avoiding a recurrent "off-track" lesion in 32% of patients, which would otherwise have occurred with complete remodeling.

The modified Latarjet procedure in female patients: clinical outcomes and complications

BACKGROUND

The aim of this study was to assess the short- and medium-term complications and clinical outcomes of female patients after a modified Latarjet procedure. A review of the literature was also conducted for outcomes of the modified Latarjet procedure in female patients and differences reported between male and female patients.

METHOD

We retrospectively reviewed the clinical notes of all female patients who had modified Latarjet procedures from 2001 with at least 1 year of follow-up. Patients were interviewed for an Oxford Shoulder Score, Western Ontario Shoulder Instability Index, Oxford Shoulder Instability Score, and subjective shoulder value. A literature review was performed of the electronic database PubMed; 343 papers were assessed for clinical outcomes based on gender.

RESULTS

Twenty-nine patients were available for inclusion in the study. There were 13 complications in 11 patients (34%). The median postoperative Western Ontario Shoulder Instability Index score was 433; Oxford Shoulder Score, 42; and Oxford Shoulder Instability Score, 36. The median subjective shoulder value was 87%. Of these patients, 37.5% returned to sport. The reoperation rate was 13.8%. We found no literature reporting the outcomes of the modified Latarjet procedure in female patients.

CONCLUSION

There are no published data comparing outcomes of the modified Latarjet procedure in male and female patients. Female patients had a lower postoperative return to sport and shoulder scores after the modified Latarjet procedure compared with literature reports. Whereas female gender should not be a contraindication to the Latarjet procedure, selection of patients in this group may need to be more stringent.

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.

Anatomic and Biomechanical Comparison of the Classic and Congruent-Arc Techniques of the Latarjet Procedure

BACKGROUND

The Latarjet procedure is commonly performed using either the classic or the congruent-arc technique. Each technique has potential clinical advantages and disadvantages. However, data on the anatomic and biomechanical effects, benefits, and limitations of each technique are limited. Hypothesis/Purpose: To compare the anatomy and biomechanical fixation strength (failure load) between the 2 techniques. It was hypothesized that the classic technique would have superior initial fixation when compared with the congruent-arc technique and that this would be affected by sex and coracoid size.

STUDY DESIGN

Controlled laboratory study.

METHODS

A biomechanical cadaver study was performed with 20 pairs of male and female shoulders. One of each pair of shoulders was randomly assigned to receive the classic or congruent-arc technique. Coracoid and glenoid anatomic measurements were collected before biomechanical testing. A tensile force was applied through the conjoined tendon to replicate forces experienced by the coracoid graft in the early postoperative period, and the failure load was determined for each specimen.

RESULTS

The mean ± SD surface area available for fixation was 263 ± 63 mm² in the classic technique compared with 177 ± 63 mm² in the congruent-arc group ( P < .001). 36% of the glenoid width was recreated in the classic group and 50% in the congruent-arc group ( P < .001). The congruent-arc technique resulted in a significantly lower ( P = .005) mean failure load (239 ± 91 N) compared with the classic technique (303 ± 114 N). Failure load was significantly higher in males ( P = .037); male specimens had a mean failure load of 344 ± 122 N for the classic technique and 289 ± 73 N for the congruent-arc technique, and females had a mean failure load of 266 ± 98 N and 194 ± 84 N, respectively.

CONCLUSION

In this biomechanical model, the classic technique of the Latarjet procedure provided a greater surface area for healing to the glenoid and superior initial fixation when compared with the congruent-arc technique. The congruent-arc technique allowed restoration of a larger glenoid defect.

CLINICAL RELEVANCE

The classic and congruent-arc techniques of coracoid transfer have anatomic and biomechanical advantages and disadvantages that should be considered when choosing between the 2 techniques.

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.

Clinical and Anatomic Predictors of Outcomes After the Latarjet Procedure for the Treatment of Anterior Glenohumeral Instability With Combined Glenoid and Humeral Bone Defects

BACKGROUND

The Latarjet procedure for the treatment of recurrent anterior shoulder instability is highly successful, but reasons for failure are often unclear. Measurements of the "glenoid track" have not previously been evaluated as potential predictors of postoperative stability.

HYPOTHESIS

There are clinical and anatomic characteristics, including the glenoid track, that are predictive of outcomes after the Latarjet procedure.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients who underwent the Latarjet procedure for anterior shoulder instability with glenoid bone loss before October 2012 were assessed for eligibility. Patient-reported subjective data that were prospectively collected and retrospectively reviewed included demographic information, patient satisfaction, pain measured on a visual analog scale (VAS), questions regarding instability, Single Assessment Numeric Evaluation (SANE) scores, American Shoulder and Elbow Surgeons (ASES) scores, Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) scores, and Short Form-12 Physical Component Summary (SF-12 PCS) scores. Anatomic measurements were performed of the coracoid size (surface area and width), width of the conjoined tendon and subscapularis tendon, estimated glenoid defect surface area, Hill-Sachs interval (HSI), and projected postoperative glenoid track engagement. Failure was defined as the necessity for revision stabilization or continued instability (dislocation or subjective subluxation) at a minimum of 2 years postoperatively.

RESULTS

A total of 38 shoulders in 38 patients (33 men, 5 women) with a mean age of 26 years (range, 16-43 years) were included. The mean follow-up for 35 of 38 patients (92%) was 3.2 years (range, 2.0-7.9 years); 25 of 38 had undergone prior stabilization surgery, and 6 had workers' compensation claims. All mean subjective outcome scores significantly improved (P < .05), with a high median satisfaction score of 9 of 10. Eight patients had failures because of continued instability. Patients with moderate or higher preoperative pain scores (VAS ≥3) had a negative correlation with postoperative SF-12 PCS scores (ρ = 0.474, P = .022). Patients with outside-and-engaged (Out-E) or "off-track" lesions were 4.0 times more likely to experience postoperative instability (relative risk, 4.0; 95% CI, 1.32-12.2; P = .33). The width of patients' coracoid processes was also directly associated with postoperative stability (P = .014). Moreover, 50% (4/8) of failures demonstrated Out-E glenoid tracks (off-track lesions) versus 16% (4/25) of those without recurrent instability (P = .033). Five of 8 failures were considered as such because of subjective subluxation events, not frank dislocations. Four of the 6 patients with workers' compensation claims had failed results (P = .016).

CONCLUSION

Workers' compensation claims were associated with continued instability, and patients with higher preoperative pain levels demonstrated lower SF-12 PCS scores postoperatively. The concept of the glenoid track may be predictive of stability after the Latarjet procedure and may be helpful in surgical decision making regarding the treatment of Hill-Sachs lesions at risk for persistent engagement. Although stability and patient satisfaction are high after the Latarjet procedure, subjective complaints of subluxation may be more common than previously estimated.

Bone mineral density of the coracoid process decreases with age

PURPOSE

Surgical options in the treatment of recurrent anterior shoulder instability are numerous. The Latarjet procedure is one of the most common procedures performed. It has been previously demonstrated that bone mineral density decreases with age. This reduction thus increases the risk of osteoporosis and osteoporosis-related iatrogenic, traumatic or pathological fractures. The objective of this study was to quantify the bone mineral density of the coracoid process in different age groups. The hypothesis was that mineral bone density of the coracoid process decreases with age.

METHODS

Using the hospital's electronic database, 60 patients who underwent a shoulder CT scan were randomly selected retrospectively. Four groups of 15 were formed with mean ages of 20, 30, 40 and 50 years. Bone density, length, width and thickness of the coracoid process 10 mm from the tip were measured four times by two different evaluators. Bone density was expressed in Hounsfield units (HU).

RESULTS

The mean bone mineral density of the coracoid process significantly decreased with age (p < 0.0001). A lower but insignificant difference of bone mineral density was observed in females. A good inter- and intra-observer reliability was found for bone mineral density measurement of the coracoid process (0.67 and 0.7, respectively).

CONCLUSIONS

The bone mineral density of the coracoid process diminishes with age, thus confirming our hypothesis. There is a good inter- and intra-observer reliability of our CT scan-based coracoid process bone mineral density measurement rendering it reproducible in daily clinical practice.

LEVEL OF EVIDENCE

IV.

Comparison of glenohumeral contact pressures and contact areas after glenoid reconstruction with latarjet or distal tibial osteochondral allografts

BACKGROUND

Glenoid reconstruction with distal tibial allografts offers the theoretical advantage over Latarjet reconstruction of improved joint congruity and a cartilaginous articulation for the humeral head. Hypothesis/

PURPOSE

To investigate changes in the magnitude and location of glenohumeral contact areas, contact pressures, and peak forces after (1) the creation of a 30% anterior glenoid defect and subsequent glenoid bone augmentation with (2) a flush Latarjet coracoid graft or (3) a distal tibial osteochondral allograft. It was hypothesized that the distal tibial bone graft would best normalize glenohumeral contact areas, contact pressures, and peak forces.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight cadaveric shoulder specimens were dissected free of all soft tissues and randomly tested in 3 static positions of humeral abduction with a 440-N compressive load: 30°, 60°, and 60° of abduction with 90° of external rotation (ABER). Glenohumeral contact area, contact pressure, and peak force were determined sequentially using a digital pressure mapping system for (1) the intact glenoid, (2) the glenoid with a 30% anterior bone defect, and (3) the glenoid after reconstruction with a distal tibial allograft or a Latarjet bone block.

RESULTS

Glenoid reconstruction with distal tibial allografts resulted in significantly higher glenohumeral contact areas than reconstruction with Latarjet bone blocks in 60° of abduction (4.87 vs. 3.93 cm2, respectively; P < .05) and the ABER position (3.98 vs. 2.81 cm2, respectively; P < .05). Distal tibial allograft reconstruction also demonstrated significantly lower peak forces than Latarjet reconstruction in the ABER position (2.39 vs. 2.61 N, respectively; P < .05). Regarding the bone loss model, distal tibial allograft reconstruction exhibited significantly higher contact areas and significantly lower contact pressures and peak forces than the 30% defect model at all 3 abduction positions. Latarjet reconstruction also followed this same pattern, but differences in contact areas and peak forces between the defect model and Latarjet reconstruction in the ABER position were not statistically significant (P > .05).

CONCLUSION

Reconstruction of anterior glenoid bone defects with a distal tibial allograft may allow for improved joint congruity and lower peak forces within the glenohumeral joint than Latarjet reconstruction at 60° of abduction and the ABER position. Although these mechanical properties may translate into clinical differences, further studies are needed to understand their effects.

CLINICAL RELEVANCE

Glenoid bone reconstruction with a distal tibial osteochondral allograft may result in significantly improved glenohumeral contact areas and significantly lower glenohumeral peak forces than reconstruction with a Latarjet bone block, which could play a role in improving postoperative outcomes after glenoid reconstruction.

Comparison of various imaging techniques to quantify glenoid bone loss in shoulder instability

INTRODUCTION

The purpose of this study was to determine the most accurate imaging modality to quantify glenoid bone loss in recurrent anterior shoulder instability. This will allow the best preoperative prediction for patients needing a bone graft.

MATERIALS AND METHODS

Seven fresh frozen shoulder cadavers were imaged with radiographs, magnetic resonance imaging (MRI), computed tomography (CT), and 3-dimensional CT (3-D CT). Native shoulders were imaged, and 3 sequential anterior-inferior glenoid defects were created, measured, and reimaged. Defect sizes were <12.5%, 12.5% to 27%, and >27%. Four blinded evaluators (2 musculoskeletal radiologists, 2 shoulder fellowship-trained surgeons) reviewed the 112 image sets and estimated the percentage of glenoid bone loss. Images were scrambled and re-reviewed by the same observers 2 months later to determine intraobserver reliability.

RESULTS

Pearson correlation coefficients between predicted vs true bone loss across all 4 raters were 0.875 (3-D CT), 0.831 (CT), 0.693 (MRI), and 0.457 (x-ray imaging). Prediction errors (PE) were (mean ± SD in percentages) 3-D CT (-3.3 ± -6.6), CT (-3.7 ± -8.0), MRI (-2.75 ± -10.6), and x-ray images (-6.9 ± -13.1). Mean PE values were not significantly different among 3-D CT, CT, and MRI; however, the PE SDs were similar among the 4 evaluators for 3-D CT and lower than all other imaging techniques. Prediction based on x-ray images had the largest PE and SD. Covariance parameters revealed large variances for shoulders for MRI and x-ray imaging. The intraobserver intraclass correlation coefficients were 0.947 (3-D CT), 0.927 (CT), 0.837 (MRI), and 0.726 (x-ray image).

CONCLUSIONS

The most accurate imaging modality in predicting glenoid bone loss among the 4 blinded independent evaluators was 3-D CT.

3-D CT is the most reliable imaging modality when quantifying glenoid bone loss

BACKGROUND

Posttraumatic anterior shoulder instability is associated with anterior glenoid bone loss, contributing to recurrence. Accurate preoperative quantification of bone loss is paramount to avoid failure of a soft tissue stabilization procedure as bone reconstruction is recommended for glenoid defects greater than 20% to 27%.

QUESTIONS/PURPOSES

We determined whether radiography, MRI, or CT was most reliable to quantify glenoid bone loss in recurrent anterior shoulder instability.

METHODS

Seven intact fresh-frozen human cadaveric shoulders were imaged with radiography, MRI, CT, and three-dimensional (3-D) CT. Three sequential anterior glenoid defects then were created, measured, and the shoulders reimaged after each defect. Defect sizes were less than 12%, 12% to 25%, and 25% to 40%. The gold standard measurement was determined by comparing measurements taken on the cadaver by two surgeons using digital calipers with the measurements determined by using electronic digital calipers on the 3-D CT. This measurement was used for comparison of all estimations by the evaluators. Twelve independent blinded evaluators reviewed the 112 image sets and estimated the percent of glenoid bone loss. Images were scrambled and rereviewed by the same observers 2 months later to determine intraobserver reliability. We determined reliability with kappa values.

RESULTS

Kappa values between predicted bone loss versus true loss (determined by our gold standard measurements) across all 12 raters for each modality were: 3-D CT, 0.50; CT, 0.40; MRI, 0.27; and radiographs, 0.15. Interobserver agreement (kappa) values were: 3-D CT, 0.54; CT, 0.47; MRI, 0.31; and radiographs, 0.15. The intraobserver agreement (kappa) values were: 3-D CT, 0.59; CT, 0.64; MRI, 0.51; and radiographs, 0.45.

CONCLUSIONS

Three-dimensional CT was the most reliable imaging modality for predicting glenoid bone loss. Regular CT was the second most reliable and reproducible modality.

Do the traditional and modified latarjet techniques produce equivalent reconstruction stability and strength?

BACKGROUND

The Latarjet procedure has been described as a reconstructive option for instability associated with substantial glenoid bone defects. A modification, termed the Congruent-Arc, is thought to improve glenoid reconstruction through better articular congruency and greater bone reconstitution. The strengths of these techniques, however, have not been reported. Purpose/

HYPOTHESIS

To compare the fixation stability, strength, glenoid vault load transfer, and joint contact between the Classic and Congruent-Arc techniques. The authors hypothesized that the Classic Latarjet would exhibit inferior joint contact characteristics while having greater stability and strength and more normal glenoid vault strain.

STUDY DESIGN

Controlled laboratory study.

METHODS

Sixteen shoulder specimens (8 pairs) were tested by loading the glenohumeral joint with the glenoid intact, following creation of a 25% anterior bone defect, and after random assignment to the Classic or Congruent-Arc Latarjet techniques. Specimens were mounted to a testing apparatus that allowed concentric, centralized loading and loading 30° anterior on the glenoid rim. Cyclic loading (100 cycles at 1 Hz) was applied with a staircase protocol (50, 100, 150, and 200 N). Graft interface displacement and glenoid load transfer, quantified in terms of strain, were recorded during loading. Contact was quantified during 50-N loading using a thin pressure sensor. After cyclic loading, specimens were loaded to failure, defined as 5 mm of graft interface displacement.

RESULTS

The 30° loading ≥100 N resulted in significantly greater graft displacement (P < .004) in the Congruent-Arc group as compared with the Classic (mean displacement range, 0.9-2.6 vs 0.1-0.5 mm, respectively). Failure testing yielded a significantly (P = .010) greater ultimate strength for the Classic (557 N) as compared with the Congruent-Arc (392 N). Load-transfer measurements demonstrated that neither technique's glenoid vault strain values significantly differed from intact (P ≥ .076). Both techniques resulted in contact areas significantly less than intact (P < .035); however, the Congruent-Arc trended toward better contact characteristics (P = .074).

CONCLUSION

The Congruent-Arc results in significantly poorer fixation stability as compared with the Classic technique but did more closely reproduce intact joint contact, which may yield more favorable long-term outcomes.

CLINICAL RELEVANCE

Care must be taken in balancing the consideration of initial fixation stability and joint contact for the Congruent-Arc and Classic Latarjet, as these factors have opposing implications for each of the 2 reconstructions' outcomes.