Imbalance in Axial-plane Rotator Cuff Fatty Infiltration in Posteriorly Worn Glenoids in Primary Glenohumeral Osteoarthritis: An MRI-based Study

BACKGROUND

Fatty infiltration of the rotator cuff evaluated with CT has been associated with asymmetric glenoid wear and humeral head subluxation in patients with glenohumeral arthritis. The relationship between rotator cuff pathologic findings and abnormal glenoid wear plays an important role in determining the optimal surgical management of advanced glenohumeral osteoarthritis. Compared with CT, MRI has increased sensitivity for identifying rotator cuff conditions; therefore, prior studies using CT may have underestimated the association between fatty infiltration of the rotator cuff and abnormal glenoid wear.

QUESTIONS/PURPOSES

(1) Compared with Type A glenoids, which muscles in which Walch subtypes have a greater degree of fatty infiltration using Goutallier scores? (2) What glenoid type is associated with greater imbalance in fatty infiltration, as measured by comparing Goutallier scores between the posterior and anterior rotator cuff muscles? (3) What is the correlation between glenoid version and fatty infiltration of the rotator cuff muscles? (4) Comparing Type B2 and B3 glenoids with Type A glenoids, after accounting for age and sex, is there an increase in fatty infiltration of the infraspinatus muscle?

METHODS

A total of 129 shoulders from 129 patients undergoing anatomic total shoulder arthroplasty to treat primary glenohumeral osteoarthritis were retrospectively reviewed. Patients had an average age of 66.4 ± 9.3 years and an average BMI of 30.6 ± 6.7 kg/m2, and 53% (69 of 129) were men. All patients underwent MRI within 12 months before total shoulder arthroplasty to assess glenoid morphology and rotator cuff pathologic findings. Three reviewers assessed the images, and glenoid morphology was assigned using the modified Walch classification system (Types A1, A2, B1, B2, B3, C, and D). Fatty infiltration of the rotator cuff was classified using Goutallier scores. The examiners demonstrated moderate-to-good reliability using these classification systems; the Walch classification system had interrater reliability kappa coefficients (κ) from 0.54 to 0.69 and intrarater reliability κ from 0.60 to 0.64. Goutallier scores using the simplified classification system had interrater reliability κ from 0.64 to 0.68 and intrarater reliability κ from 0.64 to 0.79. Thirty-six percent (46 of 129) of the shoulders had posterior wear patterns (18% [23] were Type B2 glenoids; 18% [23] were Type B3 glenoids). The average Goutallier scores for each rotator cuff muscle were determined, and the amount of fatty infiltration was compared between the various Walch subtypes using independent t-tests. Axial-plane imbalance in fatty infiltration of the rotator cuff was assessed by determining the difference in the average fatty infiltration of the posterior rotator cuff muscles (infraspinatus and teres minor) and anterior rotator cuff muscles (subscapularis) and comparing the differences among the Walch subtypes using independent t-tests. The association between glenoid version and fatty infiltration was assessed using Pearson correlations. Finally, a multivariate logistic regression model was used to assess fatty infiltration of the rotator cuff among the various Walch subtypes while accounting for patient age and sex.

RESULTS

Compared with Type A1 glenoids, Type B2 and B3 glenoids had an increased amount of fatty infiltration of the infraspinatus (1.6 ± 0.7 versus 0.7 ± 0.4; mean difference 0.9 [95% CI 0.7-1.2]; p < 0.001 and 1.8 ± 0.4 versus 0.7 ± 0.4; mean difference 1.1 [95% CI 0.9-1.4]; p < 0.001, respectively) and teres minor (1.3 ± 0.7 versus 0.6 ± 0.5; mean difference 0.7 [95% CI 0.4-1.0]; p < 0.001 and 1.6 ± 0.6 versus 0.6 ± 0.5; mean difference 1.0 [95% CI 0.7-1.2]; p < 0.001, respectively). There was greater imbalance in fatty infiltration between the posterior and anterior rotator cuff muscles for Type B2 (0.5 ± 0.3) and B3 (0.6 ± 0.5) glenoids than for Type A1 (0.1 ± 0.3) and A2 (0.1 ± 0.6) glenoids (p < 0.001). Only the infraspinatus's fatty infiltration was strongly correlated with glenoid version (r = 0.64; p < 0.001), while fatty infiltration of the other muscles only correlated weakly or moderately. After accounting for age and sex, fatty infiltration in the infraspinatus was associated with Type B2 (OR 66.1 [95% CI 7.6-577.9]; p < 0.001) and Type B3 glenoids (OR 59.5 [95% CI 5.4-661.3]; p < 0.001) compared with Type A glenoids.

CONCLUSION

Compared with concentric wear, posteriorly worn glenoids had an imbalance in axial-plane rotator cuff fatty infiltration and an increased amount of fatty infiltration of the infraspinatus and teres minor compared with the subscapularis. These imbalances may contribute to the higher rates of failure after anatomic total shoulder arthroplasty in patients with posterior wear compared with those with concentric wear. Future research should be directed toward investigating the temporal relationship of these findings, as well as understanding the clinical outcomes for patients undergoing anatomic total shoulder arthroplasty who have posteriorly worn glenoids with a high degree of fatty infiltration of the posterior rotator cuff musculature.

CLINICAL RELEVANCE

Providers should consider the increased likelihood of higher-grade fatty infiltration of the posterior rotator cuff in the setting of posteriorly worn glenoids, particularly when treating patients without using MRI. These patients have higher rates of failure postoperatively and may benefit from closer monitoring and altered postoperative rehabilitation protocols that target the posterior rotator cuff.

Anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior lesions: A cadaveric study and preliminary report

OBJECTIVE

This study aims to investigate the anatomical relationships of the transmuscular portal to its surrounding structures in arthroscopic treatment of superior labrum anterior posterior (SLAP) lesions in a human cadaveric model.

METHODS

In this anatomic study, bilateral shoulder girdles of 12 adult formalin embalmed cadavers were used. All cadavers were male, and the mean age was 63.4±7.3 years. The portal entry point was determined as midway between the anterior and posterior borders of the acromion, approximately 1 cm lateral from the edge of the acromion. After a guidewire was placed in the glenoid cavity at the 12 o'clock position where the SLAP lesion typically occurs, a switching stick was inserted there. Each glenoid was then drilled with a 2.4 mm drill through an arthroscopic cannula. Subsequently, anatomical dissection was executed to assess the relationship of the transmuscular portal with the suprascapular nerve, axillary nerve, supraspinatus tendon, acromion, and biceps tendon. Lastly, the shortest distance between the aforementioned structures with the drill was measured by a sensitive caliper to determine whether there was a penetration of the structures. Differences between the right and left sides were analyzed.

RESULTS

The mean distance between the portal and the axillary nerve was 55.5 mm±6.0 mm, and the mean length of the suprascapular nerve was 61.2 mm±7.0 mm. The mean distance between the portal and the supraspinatus tendon was 2.8 mm±1.5 mm. No penetration of the axillary nerve, suprascapular nerve, and supraspinatus tendon was observed in any cadaver. No differences were detected for measured anatomical parameters between the right and left sides (p>0.05).

CONCLUSION

Findings from this cadaveric study revealed that the transmuscular portal may allow for a reliable anchor placement without any nerve or tendon penetration during arthroscopic SLAP repair.

LEVEL OF EVIDENCE

Level V.

Early results of reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency

BACKGROUND

Reverse total shoulder arthroplasty (rTSA) in the presence of significant glenoid bone loss remains a challenge. This study presents preliminary clinical and radiographic outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed custom metal glenoid implant to address severe glenoid bone deficiency.

METHODS

Between September 2017 and November 2018, 19 patients with severe glenoid bone deficiency underwent primary (n = 9) or revision rTSA (n = 10) using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet, Warsaw, IN, USA) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand score, Constant score, American Shoulder and Elbow Surgeons score, Simple Shoulder Test score, Single Assessment Numeric Evaluation score, and visual analog scale pain score and active range of motion were compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05.

RESULTS

Complications occurred in 4 patients (21%), including a nondisplaced greater tuberosity fracture treated conservatively in 1, intraoperative cortical perforation during humeral cement removal treated with an allograft strut in 1, and recurrent instability and hematoma formation treated with humeral component revision in 1. One patient with an early periprosthetic infection was treated with component removal and antibiotic spacer placement at an outside facility and was subsequently lost to follow-up. Eighteen patients with 1-year minimum clinical and radiographic follow-up were evaluated (mean, 18.2 months; range, 12-27 months). Significant improvements were noted in the mean Disabilities of the Arm, Shoulder and Hand score (57.4 ± 16.5 vs. 29.4 ± 19.5, P < .001), mean Constant score (24.6 ± 10.2 vs. 60.4 ± 14.5, P < .001), mean American Shoulder and Elbow Surgeons score (32 ± 18.2 vs. 79 ± 15.6, P < .001), mean Simple Shoulder Test score (4.5 ± 2.6 vs. 9.3 ± 1.8, P < .001), mean Single Assessment Numeric Evaluation score (25.4 ± 13.7 vs. 72.2 ± 17.8, P < .001), mean visual analog scale pain score (6.2 ± 2.9 vs. 0.7 ± 1.3, P < .001), mean active forward flexion (53° ± 27° vs. 124° ± 23°, P < .001), and mean active abduction (42° ± 17° to 77° ± 15°, P < .001). Mean external rotation changed from 17° ± 19° to 32° ± 24° (P = .06). No radiographic evidence of component loosening, scapular notching, or hardware failure was observed at last follow-up in any patient.

CONCLUSION

The preliminary results of rTSA using the VRS to manage severe glenoid bone deficiency are promising, but longer follow-up is necessary to determine the longevity of this implant.

Mid-term results of reverse shoulder arthroplasty for glenohumeral osteoarthritis with posterior glenoid deficiency and humeral subluxation

BACKGROUND

Results of anatomic shoulder arthroplasty for glenohumeral osteoarthritis with severe glenoid retroversion are unpredictable with a high rate of glenoid loosening. Reverse shoulder arthroplasty (RSA) has been suggested as an alternative, with good early results. We sought to confirm this at longer follow-up (minimum 5 years). The study hypothesis was that early results would endure over time.

METHODS

We retrospectively reviewed all RSAs performed in 7 centers from 1998 to 2010. The inclusion criteria were primary glenohumeral osteoarthritis with B1, B2, B3, or C glenoid. Forty-nine shoulders in 45 patients fulfilled the criteria. Bone grafting was performed in 16 cases. Clinical outcomes were evaluated with the Constant score (CS) and shoulder range of motion.

RESULTS

The mean total CS increased from 30 preoperatively to 68 points (P < .001) with significant improvements in all the subsections of the CS and range of motion. Scapular notching was observed in 20 shoulders (43%), grade 1 in 5 (11%), grade 2 in 7 (15%), grade 3 in 5 (11%), and grade 4 in 3 (6%). The glenoid bone graft healed in all the shoulders. Partial inferior lysis of the bone graft was present in 8 cases (50%). Scapular notching and glenoid bone graft resorption had no influence on the CS (P = .147 and P = .798).

CONCLUSION

RSA for the treatment of primary glenohumeral osteoarthritis in patients with posterior glenoid deficiency and humeral subluxation without rotator cuff insufficiency resulted in excellent clinical outcomes at a minimum of 5 years of follow-up.

Reverse shoulder arthroplasty for patients with glenohumeral osteoarthritis secondary to glenoid dysplasia

The purpose is to report the clinical and radiographic outcomes, complications and reoperations of reverse shoulder arthroplasty (RSA) for glenoid dysplasia. All patients who had undergone RSA for osteoarthritis secondary to underlying glenoid dysplasia were retrospectively identified. The study included twelve shoulders (11 patients), with a mean (SD) patient age of 62.2 (13.2) years and median (range) clinical follow-up of 28 (24-34) months. RSA resulted in substantial improvements in pain and function. At most recent follow-up, there was a significant improvement in forward flexion range of motion (ROM), a non-significant improvement in internal rotation ROM, and no changes in external rotation ROM. The mean (SD) SST and ASES scores were 7.8 (3.7) and 73.5 (20.4), respectively. There were no reoperations or radiographic loosening. The results were excellent in 1 case, satisfactory in 8, and unsatisfactory in 3. RSA provides acceptable function and good pain relief, though patients should be advised that shoulder rotation may be somewhat limited.

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.

Coracoacromial morphology: a contributor to recurrent traumatic anterior glenohumeral instability?

BACKGROUND

Although scapular morphology contributes to glenohumeral osteoarthritis and rotator cuff disease, its role in traumatic glenohumeral instability remains unknown. We hypothesized that coracoacromial and glenoid morphology would differ between healthy subjects and patients with recurrent traumatic anterior shoulder instability.

METHODS

Computed tomography scans of 31 cadaveric control scapulae and 54 scapulae of patients with recurrent traumatic anterior shoulder instability and Hill-Sachs lesions were 3-dimensionally reconstructed. Statistical shape modeling identified the modes of variation between the scapulae of both groups. Corresponding measurements quantified these modes in relation to the glenoid center (linear offset measures), defined by the best-fit circle of the inferior glenoid, or the glenoid center plane (angles), which bisects the glenoid longitudinally. Distances were normalized for glenoid size.

RESULTS

Compared with controls, the unstable coracoids were shorter (P = .004), with a more superior and medial offset of the tip (mean difference [MD], 7 and 3 mm, respectively; P < .001) and an origin closer to the 12-o'clock position (MD, 6°; P < .001). The unstable scapular spines originated closer to the 9-o'clock position (MD, 4°; P = .012), and the unstable acromions were more vertically oriented (MD, 6°; P < .001). The unstable glenoids had an increased height-width index (MD, 0.04; P = .021), had a flatter anterior-posterior radius of curvature (MD, 77 mm; P < .001), and were more anteriorly tilted (MD, 5°; P = .005).

CONCLUSIONS

Coracoacromial and glenoid anatomy differs between individuals with and without recurrent traumatic anterior shoulder instability. This pathologic anatomy is not addressed by current soft-tissue stabilization procedures and may contribute to instability recurrence.

Three-dimensional measurement of glenoid dimensions and orientations

BACKGROUND

Asians generally have smaller stature than Europeans and Americans, and currently available implants used in reverse shoulder arthroplasty might not fit smaller bony anatomies. However, few articles have reported glenoid geometry in the Asian population. The purpose of this study was to measure the dimensions and orientations of the glenoid from three-dimensional computed tomography reconstructions of elderly Japanese subjects.

METHODS

This study included 100 shoulders (50 males and 50 females with >50 years of age). The mean age was 67 ± 7 years for both sexes, and the mean height was 167 ± 7 cm for males and 154 ± 6 cm for females. Three-dimensional scapular models were created from computed tomographic images, and the glenoid height, glenoid width, glenoid version, glenoid inclination, vault depth, and vault width were measured.

RESULTS

The mean glenoid height and width were 38.6 and 29.4 mm for males and 33.1 and 24.4 mm for females, respectively. Both retroversion and superior inclination were approximately 3° in both sexes. The glenoid vault was deeper in the posterior region with the maximum depth of 26.1 and 23.6 mm in males and females. The vault width was narrower in the anterior region with the anterior width of 2.5 mm at 15 mm medial from the glenoid face in females.

CONCLUSION

Glenoids of Japanese females are small compared to currently available baseplates for reverse shoulder arthroplasty. These results may be helpful to aid design in smaller baseplates that better fit the anatomic geometry of the Asian glenoid.

Is CT scan a predictor of instability in recurrent dislocation shoulder?

PURPOSE

Glenoid bone defect and the defect on the posterior-superior surface of the humerus "Hill-Sachs lesion" are the commonly seen bony lesions in patients with recurrent dislocation shoulder. Computed tomography (CT) scan is considered as the best option in assessing the bony defects in the recurrent dislocation shoulder. The aim of this study was to assess the clinical and radiological co-relation in the patients with recurrent dislocation shoulder.

METHODS

Forty-four patients of recurrent dislocation shoulder who were evaluated between January 2015 and December 2017 at a tertiary care center, clinically and radiologically using CT scan and meeting the inclusion criteria, were included. The correlation between the clinical history of the number of dislocations and the bone loss using CT scan was evaluated. Two sided statistical tests were performed at a significance level of α = 0.05. The analysis was conducted using IBM SPSS STATISTICS (version 22.0).

RESULTS

All the patients were male with mean age of 25.95 (SD ± 4.2) years were evaluated. Twenty-four patients sustained injury in sporting activities while 20 patients sustained injury in training. There were an average of 4.68 (SD ± 3.1, range 2-15, median 3) episodes of dislocation. Forty-one patients had the glenoid bone loss while 40 had the Hill-Sachs lesions. The mean glenoid width defect was 10.80% (range 0-27%) while the mean Hill-Sachs defect was 14.27 mm (range 0-26.6 mm). The mean area of bone loss of the glenoid surface was 10.81% (range 0-22.4%). The lesions were on track in 34 patients and off track in 10 patients.

CONCLUSIONS

CT scan of the shoulder joint is an effective method for assessing the amount of bone loss. The number of dislocations are correlated significantly with off-track lesions and the amount of bone loss on the glenoid and Hill-Sachs lesion. The glenoid width bone loss of more than 9.80% or Hill-Sachs defect of more than 14.80 mm are the critical defects after which the frequency of dislocations increases.

Shoulder osteoarthritis in a European saber-toothed cat (Homotherium latidens) from the Lower Palaeolithic site of Schöningen (Germany)

Evaluation of a right ventral scapula fragment from a mature Homotherium latidens from Schöningen, Germany (337-300 ka before present - MIS 9) revealed lesions consisting of an osteophyte at the caudal border of the glenoid cavity, and a large, multilobular, cystic feature in the medio-caudal glenoid cavity. Based on the type of lesions, their localization, their severity, and exclusion of several nutritional and other etiologies such as immune mediated disease, joint infection (septic arthritis), and joint tumors, we conclude that the lesion was caused by trauma or age-related shoulder osteoarthritis (or possibly both). We cannot speculate whether the condition was symptomatic, but if it was, the animal must have functioned well enough to hunt or scavenge, since it survived a significant period of lesion development.

Effect of Rapid Maxillary Expansion on Condyle-fossa Relationship in Growing Patients

AIM

This study tests whether rapid maxillary expansion (RME) exerts long term effects on interglenoid fossa distance and condyle fossa relationship.

MATERIALS AND METHODS

Consecutive growing patients aged 8 to 13 years were allocated either to the RME group or control group. Cone-beam computed tomography was performed at baseline and at 6 months. Specific software was used to determine fixed landmarks. Multivariate Analysis of Covariance (MANCOVA) models were used, with time by group interaction, using age as a covariate.

RESULTS

Twenty-seven patients with a mean age of 11.4 ± 1.5 years were included. There was an overall significant group by time interaction (p = 0.012, effect size 0.59). Change in the lateral position of the glenoid fossa, the primary outcome, was reached (p = 0.008, effect size 0.258). Change in the laterolateral position of the center of the condyle, and the co-primary outcome was also significant (p = 0.011, effect size = 0.24). Nasal cavity width increased (p = 0.065, effect size = 0.14). There was an initial asymmetry in the horizontal position of the condyles that was carried on with no effect of RME.

CONCLUSION

Rapid maxillary expansion (RME) produces a significant increase in the interglenoid fossa distance and displacement of the mandibular condyles at 6 months in growing patients compared to a control group.

CLINICAL SIGNIFICANCE

The current study shows that RME is effective during growth, widening the interglenoid fossa distance and the lateral positions of the condyles and eventually enlarging the nasal cavity, without causing asymmetry.

The relationship between the glenoid track and the range of shoulder motion: A cadaver study

INTRODUCTION

The concept of the glenoid track has been proposed to evaluate the risk of dislocation. The glenoid track width was demonstrated to be 84% of the glenoid width in cadaveric shoulders and 83% in live shoulders.

HYPOTHESIS

The glenoid track width seems to be affected by the range of motion.

PURPOSE

The purpose of this study was to determine the relationship between the glenoid track and the range of shoulder motion.

METHODS

Ten fresh-frozen cadaveric shoulders were used. The specimen was fixed to a shoulder-positioning device. The anterior rim of the glenoid was marked on the humeral head using a Kirschner wire with the arm in 60° of abduction. This marking was repeated with the arm in (1) horizontal flexion/extension and (2) internal/external rotations (0° to max). The distances from the Kirschner wire markings to the footprint of the rotator cuff tendon were measured.

RESULTS

The greater the angle of the horizontal extension or external rotation, the smaller the glenoid track width, whereas the greater the angle of the horizontal flexion or internal rotation, the greater the glenoid track width. There was a negative relationship between them. The horizontal flexion/extension motion was demonstrated to affect the glenoid track width more than the internal/external rotation motion.

CONCLUSION

The glenoid track width decreased with the increase of horizontal extension. We should consider the range of horizontal extension angle when applying the glenoid track concept in clinical practice.

TYPE OF STUDY

Laboratory study.

Risk of Perforation Is High During Corrective Reaming of Retroverted Glenoids: A Computer Simulation Study

BACKGROUND

Corrective anterior reaming is an accepted method for addressing retroversion in a biconcave retroverted (Walch classification, type B2) glenoid in anatomic total shoulder arthroplasty. However, concern still exists regarding early glenoid component failure in the setting of severe retroversion, which may be related to loss of component containment and/or violation of subchondral bone resulting from reaming. The goal of this study was to determine what characteristics of B2 glenoids are less amenable to corrective reaming by virtually implanting anatomic glenoid components.

QUESTIONS/PURPOSES

(1) How much medial reaming is required to correct the version of a B2 glenoid to an acceptable position? (2) Are glenoids with more severe retroversion (> 25°) at higher risk of component perforation than less retroverted glenoids? (3) Is correcting to 10° of retroversion associated with greater risk as compared with reaming to 15°? (4) How does corrective reaming affect the underlying bone density on the glenoid face of B2 glenoids?

METHODS

A series of 71 patients with B2 glenoids (posterior subluxation of the humeral head with posterior bone loss) with CT scans who were indicated for shoulder arthroplasty were reviewed. Forty-four of 71 glenoids (62.5%) had < 25° of native retroversion. Anatomic glenoid implants were then virtually implanted using three-dimensional CT software that allows for preoperative shoulder arthroplasty planning to correct native retroversion to 15° or 10° of retroversion using both a central peg with an inverted triangle peg configuration or a keel. The amount of reaming of the anterior glenoid required to correct retroversion, perforation of peripheral pegs, or keel was compared. Additionally, assessment of the surface area of the glenoid that had poor bone density (defined as cancellous bone under the subchondral plate) was analyzed by the software after correction.

RESULTS

Correction to 15° of retroversion required 5 ± 3 mm of reaming, and correction to 10° of retroversion required 8 ± 3 mm of reaming to obtain at least 80% seating. Peripheral peg perforation with correction to 15° occurred in 15 of 27 (56%) glenoids with > 25° of retroversion compared with 10 of 44 (23%) of glenoids with < 25° of retroversion (relative risk [RR], 2.4; 95% confidence interval [CI], 1.3-4.6; p = 0.006). There was no difference in perforation with keeled components. Increased correction to 10° did not increase the risk of component perforation. When correction to 15°, glenoids with higher native version (> 25°) had a greater risk of poor bone quality support (10 of 27 [37%]) when compared with glenoids with less version (four of 44 [9%]; RR, 4.1; 95% CI, 1.5-12.8; p = 0.006). Increased correction resulted in 13 of 27 (48%) glenoids with version > 25° having poor bone density versus 10 of 44 (23%) with ≤ 25° of version (RR, 2.1; 95% CI, 1.1-4.1; p = 0.028).

CONCLUSIONS

There is a high risk of vault perforation after corrective reaming. Glenoid retroversions > 25° are at a higher risk of having poor bone quality supporting the component.

CLINICAL RELEVANCE

When contemplating options for patients with severe retroversion, surgeons should consider alternatives other than corrective reaming if achieving normal glenoid version is desired.

Arthroscopic Latarjet procedure with double-button fixation: short-term complications and learning curve analysis

BACKGROUND

The arthroscopic Latarjet with double-button fixation is a guided procedure recently proposed to treat anterior shoulder instability with glenoid bone loss. The goal of this study was to report intraoperative and early postoperative complications and to analyze the learning curve.

METHODS

This was a prospective, nonrandomized study that included 88 patients. Intraoperative or postoperative complications as well as adverse events and operative time were recorded. Clinical outcomes were evaluated at 2 weeks, 1.5 months, and at the last follow-up. Radiologic analysis was based on an immediate postoperative computed tomography scan.

RESULTS

The intraoperative complications or adverse events rate was 3.3%: 1 conversion to open surgery, 1 bone block fracture, and 1 instrumentation problem. The postoperative complication rate was 6.8%: 4 coracoid migrations, and 2 subluxations. None of these complications occurred beyond the 10th case performed. The average operative time significantly decreased with surgical experience (r = -0.8426; 95% confidence interval, -0.9074 to -0.7384; P < .0001) to reach 76 ± 12 minutes (range, 62-95 minutes) at 30 cases. Radiologically, 90% of the bone blocks were flush and subequatorial beyond the 30th case. At a mean follow-up of 12.6 months (range, 6-24 months), Walch-Duplay and Rowe scores were 80 and 81 points, respectively.

CONCLUSIONS

At short-term follow-up, the arthroscopic Latarjet procedure with double-button fixation exhibited a low complication rate. Operative time significantly improved with surgical experience and was optimized after 30 cases. Early clinical results confirmed that this procedure can be safe and reliable.

Mapping of glenoid bone loss in recurrent anterior shoulder instability: is there a particular deficit pattern?

BACKGROUND

Glenoid bone loss in recurrent anterior shoulder instability is a challenging problem for shoulder surgeons, and knowledge about the anatomy of glenoid deficits is scarce. In this study, we tried to evaluate the pattern of this pathology.

METHODS

Our analysis included 44 shoulders from 44 patients with recurrent anterior shoulder instability accompanied by a clinically relevant glenoid bone loss. The defect size, the localization of the inferior defect edge, and the defect angle were measured, and osseous landmarks were identified. An en face view on 2-dimensional computed tomography scans of each patient was fitted onto a template to create a deficit map for small (<23%) and large (>23%) defects.

RESULTS

The study cohort consisted of 9 women and 35 men with a mean age of 33 ± 11 years at the date of the scan. The defect size and localization of the inferior defect edge showed significant differences between both groups, indicating a more posterior position of larger defects. The defect angle, however, showed no significant difference between small and large defects. Both groups showed a vertical defect pattern.

CONCLUSION

The osseous glenoid deficit in recurrent anterior shoulder instability shows a vertical pattern with no remarkable differences between small and large defects. This finding can influence biomechanical models as well as surgical reconstruction.

The effect of glenoid cavity depth on rotator cuff tendinitis

INTRODUCTION

Some of the most important causes of shoulder pain are inflammation and degenerative changes in the rotator cuff (RC). Magnetic resonance imaging (MRI) is a noninvasive and safe imaging modality. MRI can be used for the evaluation of cuff tendinopathy. In this study, we evaluated the relationship between glenoid cavity depth and cuff tendinopathy and we investigated glenoid cavity depth on the pathogenesis of cuff tendinopathy.

MATERIALS AND METHODS

We retrospectively evaluated 215 patients who underwent MRI. Of these, 60 patients showed cuff tendinopathy (group A) and 54 patients showed no pathology (group B). Glenoid cavity depth was calculated in the coronal and transverse planes.

RESULTS

The mean axial depth was 1.7 ± 0.9 and the mean coronal depth 3.8 ± 0.9, for group A. The mean axial depth was 3.5 ± 0.7 and the mean coronal depth 1.5 ± 0.8, for group B. There were significant differences in the axial and coronal depths between the two groups.

CONCLUSION

High coronal and low axial depth of the glenoid cavity can be used to diagnose RC tendinitis.

Spectrum of Injury to Posterior Glenoid Labral Complex With Emphasis on Diffuse Labral Tears

The posterior glenoid labrum has numerous surrounding structures and any of them can undergo derangement. It is prudent to consider the posterior glenoid labrum complex (PGLC) as a whole rather than simply the labral tissue in isolation when evaluating magnetic resonance imaging (MRI) of the shoulder. The PGLC contains the posterior capsulolabral junction, posterior capsule (posteroinferiorly , the posterior band of the inferior glenohumeral ligament), posterior chondro-osseous junction, posterior chondrolabral junction, posterior glenoid bone, posterior glenoid subchondral bone, posterior glenoid cartilage, posterior labrum, synovial fold (variably seen), and posterior glenoid periosteum (or periosteal sleeve). Noninvasive MRI techniques are the mainstay in evaluating PGLC injury with or without the use of intra-articular gadolinium contrast agents. When using the PGLC model, a spectrum of pathology can be stratified.

Glenoid dysplasia and osteochondritis dissecans in a cat

A 2-year-old Maine Coon cat was presented for a right forelimb lameness. Computed tomography of the shoulder revealed a shallow glenoid, osteophyte deposition at the caudal humeral head and medial glenoid, and an intra-articular osseous body. This cat had glenoid dysplasia and osteochondritis dissecans of the glenoid.

Glenoid diameter is an inaccurate method for percent glenoid bone loss quantification: analysis and techniques for improved accuracy

PURPOSE

To compare diameter-based glenoid bone loss quantification with a true geometric calculation for the area of a circular segment.

METHODS

By use of Maxima 12.01.0 mathematics modeling software (Macysma, Boston, MA), the diameter-based glenoid bone loss equation (% Bone loss = [Defect width (w)/Inferior glenoid circle diameter (D)] × 100%) was compared with a true geometric calculation for the area of a circular segment of the glenoid (Wolfram Research, Champaign, IL) rearranged in terms of w and D: Percent bone loss = (100/2π) (2 × arccos [1 - 2 (w/D)] - sin {2 × arccos [1 - 2 (w/D)]}). Percent error was calculated by taking the difference between the diameter equation and the true geometric calculation at varying true glenoid defect widths (w) (0% to 50% of diameter).

RESULTS

The commonly used diameter equation overestimated true glenoid bone loss at all values of w except at 0% and 50% of the diameter. The mean overestimation error was 3.9% ± 1.9% (range, 0.0% to 5.8%), with the maximum error occurring when w was 20% of the diameter: At this value, w/D × 100% (diameter equation) predicts 20% bone loss when true bone loss is actually 14.2%.

CONCLUSIONS

Diameter-based glenoid bone loss quantification overestimates true glenoid bone loss, with the maximum error occurring when theorized bone loss is 20%. To address situations for which a diameter-based bone loss quantification method must be performed or to improve the accuracy of surface-area calculations in previous diameter-based bone loss estimations, a corrective factor can be applied. Clinicians quantifying glenoid loss to make treatment decisions should be aware of the measurement methods used in the biomechanical studies on which they are basing their surgical decisions.

CLINICAL RELEVANCE

Diameter-based glenoid bone loss quantification overestimates true glenoid bone loss, with the maximum error occurring when theorized bone loss is 20%, a commonly used threshold for bone grafting.

The Latarjet-Patte procedure for recurrent anterior shoulder instability in contact athletes

Recurrent anterior shoulder instability is common in contact athletes and the high-energy injuries seen in this group make them more prone to bone loss. Athletes with recurrent instability and associated bone loss have high failure rates when treated with a soft tissue reconstruction procedure. Therefore it is preferred to manage recurrent instability in contact athletes with the Latarjet-Patte procedure. In this article, the authors describe their technique. They have found this procedure to be safe and effective, with very low recurrence and early return to sport. A meticulous surgical technique is important to avoid intraoperative and postoperative complications.

Arthroscopic Bristow-Latarjet combined with bankart repair restores shoulder stability in patients with glenoid bone loss

BACKGROUND

Arthroscopic Bankart repair alone cannot restore shoulder stability in patients with glenoid bone loss involving more than 20% of the glenoid surface. Coracoid transposition to prevent recurrent shoulder dislocation according to Bristow-Latarjet is an efficient but controversial procedure.

QUESTIONS/PURPOSES

We determined whether an arthroscopic Bristow-Latarjet procedure with concomitant Bankart repair (1) restored shoulder stability in this selected subgroup of patients, (2) without decreasing mobility, and (3) allowed patients to return to sports at preinjury level. We also evaluated (4) bone block positioning, healing, and arthritis and (5) risk factors for nonunion and coracoid screw pullout.

METHODS

Between July 2007 and August 2010, 79 patients with recurrent anterior instability and bone loss of more than 20% of the glenoid underwent arthroscopic Bristow-Latarjet-Bankart repair; nine patients (11%) were either lost before 2-year followup or had incomplete data, leaving 70 patients available at a mean of 35 months. Postoperative radiographs and CT scans were evaluated for bone block positioning, healing, and arthritis. Any postoperative dislocation or any subjective complaint of occasional to frequent subluxation was considered a failure. Physical examination included ROM in both shoulders to enable comparison and instability signs (apprehension and relocation tests). Rowe and Walch-Duplay scores were obtained at each review. Patients were asked whether they were able to return to sports at the same level and practice forced overhead sports. Potential risk factors for nonhealing were assessed.

RESULTS

At latest followup, 69 of 70 (98%) patients had a stable shoulder, external rotation with arm at the side was 9° less than the nonoperated side, and 58 (83%) returned to sports at preinjury level. On latest radiographs, 64 (91%) had no osteoarthritis, and bone block positioning was accurate, with 63 (90%) being below the equator and 65 (93%) flush to the glenoid surface. The coracoid graft healed in 51 (73%), it failed to unite in 14 (20%), and graft osteolysis was seen in five (7%). Bone block nonunion/migration did not compromise shoulder stability but was associated with persistent apprehension and less return to sports. Use of screws that were too short or overangulated, smoking, and age higher than 35 years were risk factors for nonunion.

CONCLUSIONS

The arthroscopic Bristow-Latarjet procedure combined with Bankart repair for anterior instability with severe glenoid bone loss restored shoulder stability, maintained ROM, allowed return to sports at preinjury level, and had a low likelihood of arthritis. Adequate healing of the transferred coracoid process to the glenoid neck is an important factor for avoiding persistent anterior apprehension.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Endoscopic sonography and sonographically guided fine-needle aspiration biopsy in the diagnosis of unusual pancreatic metastases from synovial sarcoma

Pancreatic metastases are commonly solitary solid lesions frequently derived from primary renal cell carcinoma, lung cancer, or melanoma. Very few case reports have described cystic-appearing metastases in the pancreas and even fewer have reported a combination of cystic and solid metastatic lesions. Synovial sarcoma is a rare and aggressive soft tissue neoplasm, frequently metastasizing to the lungs and bones. We present a case of primary synovial sarcoma with multiple solid and cystic-appearing pancreatic metastases diagnosed by endoscopic ultrasound and sonographically guided fine-needle aspiration.

Glenoid fracture after arthroscopic Bankart repair: case series and biomechanical analysis

To examine whether anchors used in arthroscopic Bankart repair increased the risk of subsequent fracture, six intact polyurethane scapulae and six with three 3.0-mm suture anchors placed along the anteroinferior glenoid were compared. An axial load of 1 mm/s was applied to the anteroinferior glenohumeral joint with a prosthetic humeral head. Outcome measures were force needed for initial fracture and catastrophic failure, percent of anterior glenoid bone loss, and fracture length. With the numbers available, no significant differences could be detected between groups in yield load or maximum load. The anchor group had a significantly larger percentage of bone loss (p < .01) and fracture length (p < .01) compared to the intact group. In this study, anchors did not decrease force needed to fracture but did lead to significantly larger fractures of the anterior glenoid during a simulated dislocation event. Further study using various anchors and techniques is warranted.

Shoulder instability with concomitant bone loss in the athlete

Thorough evaluation of the athlete with persistent shoulder instability and appropriate use of imaging modalities, such as 3-dimensional computed tomography, can help quantify the severity of bony deficiency. Based on obtained imaging and examination, surgical and nonsurgical methods can be considered. In many situations both the humeral- and glenoid-sided bone loss must be addressed. Depending on the extent of bone loss, athletic demands, and surgeon experience, arthroscopic or open surgical options can provide shoulder stability and return athletes to their prior level of activity.

Biomechanical impact of posterior glenoid wear on anatomic total shoulder arthroplasty

INTRODUCTION

This study quantified bone removed to correct three different sizes of posterior glenoid defects and also quantified the change in rotator cuff muscle length resulting from correction of each defect using three different glenoid designs.

METHODS

A 3-D computer model quantified the cortical and cancellous bone removed when correcting three sizes of posterior glenoid defects and simulated internal/external rotation to quantify changes in rotator cuff muscle length when correcting glenoid retroversion in three sizes of posterior glenoid defects using three different glenoid prostheses: 1. eccentric reaming using a non-augmented glenoid (Equinoxe standard pegged), 2. 8°, 12°, and 16° Equinoxe posterior augment glenoid (wedge), and 3. 3 mm, 5 mm, and 7 mm Global Step-Tech posterior augment glenoid (step).

RESULTS

For small defects, the 8° wedge and 3 mm step posterior augment glenoids conserves 50% (1.295 cm 3 ) and 23% (1.704 cm 3 ) more bone than eccentric reaming (2.147 cm 3 ), respectively. For medium defects, the 12° wedge and 5 mm step glenoids conserves 69% more (1.295 cm 3 ) and 2% less (2.720 cm 3 ) bone than eccentric reaming (2.655 cm 3 ), respectively. For large defects, the 16° wedge and 7 mm step glenoids conserve 48% more (1.852 cm 3 ) and 36% less (4.343 cm 3 ) bone than eccentric reaming (3.736 cm 3 ), respectively. For each size defect, muscle shortening was observed for both eccentric reaming and each augmented glenoid design. Eccentric reaming medialized the humerus and resulted in additional muscle shortening (wedge: 2.0%, 2.9%, and 3.6%; step: 1.2%, 1.7%, and 1.7%) in each size defect, respectively.

DISCUSSION AND CONCLUSIONS

Both step and wedge augmented glenoid designs conserved more anterior glenoid bone and were associated with less muscle shortening than correction with eccentric reaming. However, wedge posterior augment glenoids medialized the humerus less and were observed to be more bone conserving than step posterior augment glenoids, particular in large glenoid defects.

Addressing glenoid erosion in reverse total shoulder arthroplasty

Severe glenoid wear is technically problematic, has a higher complication rate, and inferior results in the setting of shoulder arthroplasty. This paper introduces four basic strategies for treating glenoid erosion with a reverse shoulder arthroplasty which include; 1. eccentric reaming, 2. bone grafting of glenoid, 3. reaming and bone grafting, and 4. using augmented baseplates. The benefits and shortcomings of each of these techniques are discussed. The reverse shoulder arthroplasty has many advantages over anatomic shoulder arthroplasty when dealing with severe glenoid defects. Augmented baseplates are new and allow the surgeon to treat various different glenoid defects with preservation of glenoid subchondral bone.

Addressing glenoid erosion in anatomic total shoulder arthroplasty

Glenoid wear is common in the setting of shoulder arthritis. Severe glenoid erosion presents a serious challenge to the surgeon performing a shoulder arthroplasty. This paper presents the various classification schemes for glenoid erosion. The results of the six main treatment options for shoulder arthroplasty with an eroded glenoid are reviewed. The six treatment options include: 1. eccentric reaming, 2. bone grafting, 3. use of inset glenoid, 4. use of an augmented (asymmetric) glenoid component, 5. hemiarthroplasty, and 6. reverse shoulder arthroplasty. A treatment algorithm is proposed based on the amount of glenoid erosion. Severe glenoid wear resulting in the need for shoulder replacement surgery is a challenge; however, new tools for dealing with this complicated entity are rapidly evolving, including the use of augmented anatomic glenoid components and reverse shoulder arthroplasty with augmented baseplates.

Reconstruction of massive uncontained glenoid defects using a combined autograft-allograft construct with reverse shoulder arthroplasty: preliminary results

BACKGROUND

This report documents our experiences with a new technique for reconstructing massive uncontained defects of the glenoid with reverse total shoulder arthroplasty.

MATERIALS AND METHODS

We use a modified deltopectoral approach to perform the combined allograft-autograft construct glenoid reconstruction. We make use of a peripherally seated cortical allograft acting as a sleeve bushing to provide a stable ring under compression in which to house impacted cancellous autograft centrally for early incorporation and in-growth with the long-peg Aequalis (Tornier, Saint-Ismier Cedex, France) reverse total shoulder arthroplasty baseplate.

RESULTS

Our case series now comprises 10 patients with postoperative follow-up of up to 36 months. We report the first 5 patients here, all of whom have more than 12 months of follow-up. Computed tomography scanning demonstrates incorporation of the graft as early as 6 months. None of these patients have had loosening, implant failures, dislocations, periprosthetic fractures, or infections. One patient sustained an acromial stress fracture that was successfully treated nonoperatively, and 1 patient has nonprogressive grade I notching.

CONCLUSION

The hybrid graft glenoid reconstruction is a useful and versatile technique in the setting of massive uncontained defects of the glenoid and permits the implantation of a reverse total shoulder arthroplasty. We believe this technique is reproducible and uses materials that are both readily available and familiar.