Glenoid Loss Research Articles

OSTEOCHONDRAL GLENOID LOSS: REMAINING GLENOID DEPTH AND CONCAVITY ARE STRONGER PREDICTIVE PARAMETERS FOR SHOULDER INSTABILITY THAN DEFECT SIZE

Osteochondral glenoid loss is associated with recurrent shoulder instability. The critical threshold for surgical stabilization is multidimensional and conclusively unknown. The aim of this work was to provide a well- measurable surrogate parameter of an unstable shoulder joint for the frequent anterior-inferior dislocation direction.The shoulder stability ratio (SSR) of 10 paired human cadaveric glenoids was determined in anterior-inferior dislocation direction. Osteochondral defects were simulated by gradually removing osteochondral structures in 5%-stages up to 20% of the intact diameter. The glenoid morphological parameters glenoid depth, concavity gradient, and defect radius were measured at each stage by means of optical motion tracking. Based on these parameters, the osteochondral stability ratio (OSSR) was calculated. Correlation analyses between SSR and all morphological parameters, as well as OSSR were performed.The loss of SSR, concavity gradient, depth and OSSR with increasing defect size was significant (all p<0.001). The loss of SSR strongly correlated with the losses of concavity gradient (PCC = 0.918), of depth (PCC = 0.899), and of OSSR (PCC = 0.949). In contrast, the percentage loss based on intact diameter (defect size) correlated weaker with SSR (PCC=0.687). Small osteochondral defects (≤10%) led to significantly higher SSR decrease in small glenoids (diameter <25mm) compared to large (≥ 25mm) ones (p ≤ 0.009).From a biomechanical perspective, the losses of concavity gradient, glenoid depth and OSSR correlate strong with the loss of SSR. Therefore, especially the loss of glenoidal depth may be considered as a valid and reliable alternative parameter to describe shoulder instability. Furthermore, smaller glenoids are more vulnerable to become unstable in case of small osteochondral loosening. On the other hand, the standardly used percentage defect size based on intact diameter correlates weaker with the magnitude of instability and may therefore not be a valid parameter for judgement of shoulder instability.

Coracoid graft resorption after the Latarjet procedure does not depend on the preoperative glenoid defect.

The primary purpose was to compare coracoid graft resorption after the Latarjet procedure in patients without preoperative glenoid bone loss vs. those with more than critical glenoid loss. The secondary purposes were to compare the functional outcomes and to investigate the association of graft position, angle of the screws, preoperative glenoid defect, age at surgery, and smoking status with graft resorption. Sixty consecutive patients with recurrent anterior instability were treated by the Latarjet procedure as the index procedure, irrespective of the glenoid bone loss between 2018 and 2021. Fifty-five patients were evaluated via computed tomography scans after a minimum of 1 year after surgery (range: 1-4 years). Twenty-five patients had no prior glenoid defect (No-defect group), 24 patients had preoperative glenoid defects ≥15% (Critical defect group), and 6 patients had glenoid defects between 5% and 15%. The No-defect group (n=25) was compared with the Critical defect group (n=24). Multivariate logistical regression was performed to evaluate the association of independent factors with the grade of resorption for all 55 patients in the cohort. Major graft resorption at the level of the superior screw was observed in 72%-84% of patients in the No-defect group (n=25) and in 75%-83% of patients in the Critical defect group (n=24) (P=1, P=1; no significant difference). No to mild resorption at the level of the inferior screw was observed in 96% of patients in the No-defect group and 100% of patients in the Critical defect group (P=1; no significant difference). Postoperative Rowe scores (100 [95-100] vs. 100 [95-100]; P=.8) and shoulder subjective value (87 [11] vs. 86 [9]; P=.9) were not significantly different between the 2 groups. None of the independent factors, including the corresponding screw angle, the mediolateral graft positioning, prior glenoid defect, age, and smoking status, were associated with graft resorption in multivariate logistical regression. Graft resorption after the Latarjet procedure does not depend on the preoperative glenoid defect. The coracoid graft may be mostly resorbed around the superior screw but mildly or none at the level of the inferior screw, but this graft resorption is not dependent on the smoking status, age, prior glenoid defect, mediolateral graft positioning, and the angle of the screws.

Arthroscopic Trillat technique for chronic post-traumatic anterior shoulder instability: outcomes at 2 years of follow-up.

The purpose of this study was to assess the outcomes of a new arthroscopic Trillat technique at a 2-year follow-up. Our current hypothesis was that this technique could be used for the effective treatment of chronic post-traumatic unidirectional anterior shoulder instability, and that the recurrence and complication rates, external rotation, and functional outcomes would be as good as those of the reference technique. Between April 2012 and August 2016, all patients older than 16 years who underwent the arthroscopic Trillat technique for unidirectional chronic post-traumatic anterior shoulder instability at the Dijon University Hospital (France), after the failure of well-conducted medical and rehabilitation treatment with at least 24 months of follow-up, were included. Criteria for noninclusion were association with posterior and/or inferior instabilities, voluntary instabilities, and glenoid bone loss greater than 20%. Patients attended follow-up with their surgeon before the intervention, in the immediate postoperative period, at 6 weeks, 3 and 6 months, and then by an independent observer for the last evaluation. Patients were then examined clinically with scores such as Constant, Rowe and Walch-Duplay scores, and subjective shoulder value, for shoulder range of motion, and radiographically (anteroposterior and Lamy's lateral x-rays of the operated shoulder). Forty-nine patients and 52 shoulders were included, with a mean follow-up of 40 months (range, 24-71 months). The recurrence rate of instability was 3.8% (2 of 52). No conversion to arthrotomy was necessary. No intraoperative complications, postoperative neurological lesions, or sepsis were observed. The mean Constant score was 92.1 (77.5-100) points, Walch-Duplay 82.9 (40-100), Rowe 81.73 (5-100), and subjective shoulder value 86.1 (50-100) at the last follow-up. The arm at side external rotation limitation averaged 8.4° (-25° to 40°) and the external rotation with 90° arm abduction limitation 0.34° (-5° to 15°). Forty-one patients (79%) resumed their sports activity at the same level. Fifty patients (96%) were satisfied to very satisfied. One patient developed nonunion of the coracoid process and subsequently underwent a Latarjet procedure with a good outcome. The arthroscopic Trillat procedure offers good outcomes as a first-line treatment for chronic anterior post-traumatic glenohumeral instability. It should be excluded in cases of glenoid loss greater than 20%.

Is Revision Bankart Repair with Remplissage a Viable Option for Failed Bankart Repair in Non-contact Sports Person Aiming to Return to Sports?

Failure of a well-executed Bankart repair in non-contact athletes is difficult to predict and its management is a lesser investigated area with uncertain outcome in terms of return to sports (RTS). This study analyses effectiveness of revision Bankart repair with remplissage for failed Bankart repair in non-contact athletes, focusing on time and level of RTS. Fifty-five consecutive non-contact athletes with evidence of instability after primary arthroscopic Bankart repair having glenoid loss < 25% and off-track Hill-Sachs lesion were included in the study according to algorithm mentioned. All cases underwent revision arthroscopic Bankart repair with remplissage and followed-up for 24months. Rowe, UCLA, WOSI and Quick-DASH scores were recorded preoperative and at 24months. RTS was allowed after unilateral seated shot-put test. Out of 55 cases, 6 were excluded because of poor tissue quality, 7 were lost to follow-up. Forty-two cases with a mean age of 28.2 ± 5.2years were included. Mean duration between primary surgery and failure was 7.3 ± 1.4months with a mean 1.9 redislocations. The mean Rowe, WOSI, UCLA, Quick-DASH scores improved from 37 to 89, 39.3 to 83.7%, 18.4 to 30.5, 45.3 to 18.7 at 24months. Thirty-five cases could RTS in a mean time 15.4 ± 1.4months. Out of seven cases who could not RTS, four had instability, one had pain and two voluntarily quit sports. Revision Bankart repair with remplissage is a feasible option for failed primary Bankart repair in non-contact athletes who have glenoid bone loss < 25% with off-track Hill-Sachs. Level IV.

Glenoid erosion is a risk factor for recurrent instability after Hill-Sachs remplissage.

The aim of this study was to identify risk factors for recurrent instability of the shoulder and assess the ability to return to sport in patients with engaging Hill-Sachs lesions treated with arthroscopic Bankart repair and Hill-Sachs remplissage (ABR-HSR). This retrospective study included 133 consecutive patients with a mean age of 30 years (14 to 69) who underwent ABR-HSR; 103 (77%) practiced sports before the instability of the shoulder. All had large/deep, engaging Hill-Sachs lesions (Calandra III). Patients were divided into two groups: A (n = 102) with minimal or no (< 10%) glenoid bone loss, and B (n = 31) with subcritical (10% to 20%) glenoid loss. A total of 19 patients (14%) had undergone a previous stabilization, which failed. The primary endpoint was recurrent instability, with a secondary outcome of the ability to return to sport. At a mean follow-up of four years (1.0 to 8.25), ten patients (7.5%) had recurrent instability. Patients in group B had a significantly higher recurrence rate than those in group A (p = 0.001). Using a multivariate logistic regression, the presence of glenoid erosion of > 10% (odds ratio (OR) = 35.13 (95% confidence interval (CI) 8 to 149); p = 0.001) and age < 23 years (OR = 0.89 (0.79 to 0.99); p = 0.038) were associated with a higher risk of recurrent instability. A total of 80 patients (78%) could return to sport, but only 11 athletes (65%) who practiced high-risk (collision or contact-overhead) sports. All seven shoulders which were revised using a Latarjet procedure were stable at a mean final follow-up of 36 months (11 to 57) and returned to sports at the same level. Patients with subcritical glenoid bone loss (> 10%) and younger age (≤ 23 years) are at risk of failure and reoperation after ABR-HSR. Furthermore, following this procedure, one-third of athletes practicing high-risk sports are unable to return at their pre-instability level, despite having a stable shoulder. Cite this article: Bone Joint J2021;103-B(4):718-724.

Distal Tibial Plafond Allograft Transplant for Anterior Shoulder Instability

Anterior shoulder instability is a relatively common condition particularly in the athletic population. It can lead to alterations in shoulder mechanics that can cause significant restrictions for patients. This condition becomes particularly difficult to treat in the revision setting. A handful of widely accepted procedures to address anterior shoulder instability have been described. Distal tibial allograft for anterior shoulder instability in the setting of large glenoid loss and revision cases has been shown to be on par with other graft types. In this chapter we will discuss a technique of distal tibia allograft use for anterior shoulder instability cases.

Advances in Glenoid Design in Anatomic Total Shoulder Arthroplasty.

➢ Rotator cuff imbalance, soft-tissue and capsular repair defects, and improper component sizing, positioning, and orientation can result in a high-stress environment at the periphery of the glenoid component-bone interface.➢ The optimal position and orientation of the glenoid for a given individual is currently unknown.➢ There have been advancements in glenoid design, with the advent of contemporary metal-backed and hybrid components, but their long-term efficacy has not been proven. Inset glenoid components have shown promising short- and mid-term results.➢ The augmented glenoid, which has shown satisfactory short-term results in the setting of posterior glenoid loss, is a potential option for glenoid bone loss that is too severe for eccentric reaming. It may be technically easier than bone-grafting, does not require union, and is not at risk of collapse or bone graft resorption.➢ Advances in surgical technique, including patient-specific instrumentation, may provide additional accuracy, especially in dysplastic and eccentrically worn glenoids; however, evidence for clinical benefit is still lacking.

The Latarjet Procedure: Effective and Safe

Background: The Latarjet procedure is used to treat recurrent anterior shoulder instability in patients with bony glenoid loss and/or failed previous stabilisation surgery. It has reportedly high success rates, but recent publications have reported concerns of high complication rates. This study aims to assess the complications and outcomes of the Latarjet procedure in our institution, with a minimum 2-year follow-up and compared it to the current literature. Methods: Patients who underwent the procedure over a 36-month period were included in this study (n=81). Seventy-three (90%) patients in our cohort competed in amateur to professional level sports. The indications for surgery were recurrent instability with associated bony glenoid deficiency and/or previous failed arthroscopic stabilisations. The Oxford Shoulder Instability, Constant Shoulder and QuickDASH scores were recorded pre- and post-operatively, along with post-operative complications and failures. Results: Eight (9.9%) complications were recorded: three re-dislocations, two deep infections, one haematoma, one screw breakage and one case of biceps tendinopathy. The mean pre-operative Oxford Shoulder Instability Score improved from 23.2 ± 10.1 to 37 ± 9.2 following the procedure. The mean Constant Shoulder and quickDASH scores also improved from 55.1 ± 21.2 and 30.3 ± 24.3 to 88.1 ± 9.2 and 17.7 ± 23.5 respectively. 98.6% of the patients returned to their pre-injury level of sports. Conclusion: From this study it can be concluded the Latarjet procedure is an effective surgical treatment for recurrent anterior shoulder instability associated with bony glenoid loss, even in high contact professional athletes. Complication rates are lower than previous recent studies have stated.

The Instability Severity Index Score Revisited: Evaluation of 217 Consecutive Cases of Recurrent Anterior Shoulder Instability

Objectives: The instability severity index score (ISIS) was designed to predict the risk of recurrence after arthroscopic instability shoulder surgery and to better predict those who would benefit from an open or bone transfer operation. Although this score has been widely disseminated to predict recurrence, there are certain areas in which preoperative assessment is limited, especially in radiographic workup. The objective of this study was to examine the validity of ISIS based on its existing variables, as well as to evaluate additional imaging and patient history variables pertinent to the potential redevelopment of a new score to assess risk of recurrent anterior instability following an arthroscopic Bankart repair. Methods: All consecutive patients were prospectively enrolled with recurrent anterior shoulder instability who subsequently underwent an arthroscopic stabilization with minimum 24 months follow-up. Exclusion criteria included, prior surgery on the shoulder, posterior or multidirectional instability, or a rotator cuff tear. All instability severity index score variables were recorded (age &lt;20, degree and sport type, hyperlaxity, Hill Sachs on AP xray, glenoid loss of contour on AP xray), as well as additional variables: 1. Position of arm at dislocation; 2. Number of instability events; 3. Total time of instability; 4. Glenoid bone loss percent; 5. Amount of attritional glenoid bone loss; 6. Hill Sachs measures (H/W/D and volume), and outcomes (recurrent instability) and scores (WOSI, ASES and SANE). Regression analysis was utilized to determine preoperative variables that predicted outcomes and failures. Results: There were 217 consecutive patients (209 male-96.5%, 8 female-3.5%) who met criteria and were all treated with a primary arthroscopic shoulder stabilization during a 3.5-year period (2007-2011), with mean follow-up of 42 (range, 26-58 mos). The mean age at first instability event was 23.9 (range, 16-48), with 55% right shoulder affected, 60% dominant shoulder. Outcomes were improved from mean scores preoperative (WOSI=1050/2100, ASES=61.0, SANE=52.5) to postoperative (WOSI=305/2100, ASES=93.5, SANE=95.5), and 11.5% (25/217) had evidence or recurrent instability or subluxation. A total of 51/217 were 20 years or under, hyperlaxity in 5, Hill Sachs on internal rotation XR in 77, glenoid contour on AP XR in 41, with an overall mean ISIS score of 3.6. Factors associated with failure were glenoid bone loss greater than 14.5%(p&lt;0.001), total time of instability symptoms &gt;11.5 months(p&lt;0.03), Hill Sachs volume &gt; 1.3 cm3 with H&gt;1.5 cm, W&gt;1.0 cm and D&gt;5 mm(p&lt;0.01), contact sport (p&lt;0.01) and age 20 or under (p&lt;0.01). There was no correlation in outcomes with Hill Sachs on IR or glenoid contour on XR (p&gt;0.45), sports participation, and Instability Severity Score (mean=3.4 success, vs 3.9 failure, p&gt;0.44). Conclusion: At nearly four years of follow-up, there was an 11.5% failure rate of scope stabilization surgery. However, there was no correlation between treatment outcome and the ISIS measure given a mean score of 3.4 with little difference identified in those that failed. However, several important parameters previously unidentified were detected including, glenoid bone loss &gt;14.5%, Hill Sachs volume &gt;1.3 cm3, and time length of instability symptoms. Therefore, the ISIS measure may need to be redesigned in order to incorporate variables that more accurately portray the actual risk of failure following arthroscopic stabilization.

Open Latarjet Reconstruction: Tips for Success

The Latarjet coracoid transfer is a key procedure for reducing anterior shoulder instability in patients with glenoid bone loss. New evidence suggests that subcritical glenoid bone loss, particularly in revision situations, portends an increased risk of recurrent instability. High recurrent instability rates associated with nonoperative management and revision soft tissue stabilization make the Latarjet and other bony stability procedures a must in an orthopaedic surgeons repertoire of recurrent anterior instability management. The long-term outcomes of the Latarjet surpass revision stabilization by soft-tissue correction in those with significant glenoid loss. Despite the promising outcomes of the Latarjet, the complication rate remains high. We present a practical guide to the open Latarjet procedure, addressing many of technical challenges to aid the reader in future decision-making regarding indications, approach, exposure, surgical technique, and rehabilitation.

The Bony Bankart Lesion: How to Measure the Glenoid Bone Loss.

SummaryAn osseous Bankart lesion is commonly seen in patients with an anterior shoulder dislocation. It is defined as a detachment of the anteroinferior labrum associated with a glenoid rim fracture. Radiological studies are crucial not only for detecting glenoid bone defects but also for measuring the amount of bone loss. The precise quantification of the bony defect is crucial for the therapeutic desicion-making and clinical outcomes. Although we know that major glenoid bone loss requires surgical intervention, none of the studies performed so far answered the question what size of the defect should be an indication for open surgery procedures. Moreover, there is still no consensus on the exact percentage of glenoid loss that results in a higher risk of re-dislocations. In our opinion, there is a strong need for a consensus on universally accepted measuring techniques of the glenoid defect as well as on algorithms with validated glenoid bone loss threshold values for therapeutic decision-making. In this study, we review the techniques described so far in the literature and try to assess if any of these techniques should be treated as a leading method of detecting and quantifying osseous glenoid lesions.

Critical Value of Anterior Glenoid Bone Loss That Leads to Recurrent Glenohumeral Instability After Arthroscopic Bankart Repair

Background: Generally, a glenoid bone loss greater than 20% to 25% is considered critical for poor surgical outcomes after a soft tissue repair. However, recent studies have suggested that the critical value should be lower. Purpose: To determine the critical value of anterior glenoid bone loss that led to surgical failure in patients with anterior shoulder instability. Study Design: Case-control study; Level of evidence, 3. Methods: The study included 169 patients with anterior glenoid erosion. The percentage of glenoid erosion was calculated as the ratio of the glenoid loss width and the glenoid width to the diameter of the outer-fitting circle based on the inferior portion of the glenoid contour. The critical value of the glenoid bone loss was analyzed by means of receiver operating characteristic (ROC) curve analysis. Patients were divided into 2 groups based on the amount of glenoid bone loss: group A (less than the critical value) and group B (more than the critical value). Patients evaluated their shoulder function as a percentage of their preinjury level using the Single Assessment Numeric Evaluation (SANE) score, and postoperative clinical outcomes were assessed with the American Shoulder and Elbow Surgeons (ASES) score and Rowe score. Surgical failure was defined as the need for revision surgery or the presence of subjective symptoms of instability. Results: The optimal critical value of glenoid bone loss was 17.3% (area under the curve = 0.82; 95% confidence interval, 0.73-0.91; P < .001; sensitivity 75%; specificity 86.6%). Group A and B contained 134 and 35 patients, respectively. Shoulder functional scores were significantly lower in group B than in group A (P < .001). Five patients (3.7%) in group A and 15 (42.9%) in group B had surgical failure (P < .001). The SANE score was significantly lower in group B (83.8 ± 12.1) than in group A (92.9 ± 4.7, P = .001). Conclusion: An anterior glenoid bone loss of 17.3% or more with respect to the longest anteroposterior glenoid width should be considered as the critical amount of bone loss that may result in recurrent glenohumeral instability after arthroscopic Bankart repair.

Total shoulder arthroplasty for glenohumeral arthritis associated with posterior glenoid bone loss: results of an all-polyethylene, posteriorly augmented glenoid component

Posterior glenoid bone loss is commonly encountered in total shoulder arthroplasty (TSA). The purpose of our study is to report the clinical and radiographic findings of patients with a minimum of 2 years' follow-up treated with an all-polyethylene, augmented glenoid component. Twenty-two shoulders with posterior glenoid bone loss were treated by a single surgeon. All underwent primary TSA using a posteriorly augmented, all-polyethylene, stepped glenoid component. Outcome data included visual analog scale, Western Ontario Osteoarthritis of the Shoulder index, and Short Form 36 scores. Radiographic analysis was performed to evaluate bone-cement interface lucency, implant seating, and osseous integration of the central peg. The mean follow-up period was 36 months. Average preoperative retroversion measured with computed tomography scan was 23.5°. In addition to statistically significant increases in forward flexion and external rotation, the visual analog scale score, Western Ontario Osteoarthritis of the Shoulder score, and Short Form 36 physical component summary score all improved significantly (P < .001). Twelve shoulders had osseous integration between the central-peg flanges, 6 had bone adjacent to the central-peg flanges but without identifiable osseous integration, and 1 showed osteolysis. The mean Lazarus score was 0.5. All glenoids had perfect seating scores. Two patients sustained a total of 3 episodes of prosthetic instability. Early results of a posteriorly augmented, all-polyethylene, stepped prosthetic glenoid component to address posterior glenoid loss in TSA are encouraging. Continued evaluation will determine prosthetic longevity and maintained clinical improvement.

Glenoid Diameter Is an Inaccurate Method for Percent Glenoid Bone Loss Quantification: Analysis and Techniques for Improved Accuracy

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

Redefining Critical Bone Loss in Shoulder Instability

Glenoid bone deficiency has been implicated as a significant risk factor for failure after arthroscopic stabilization, with data suggesting that 20% to 25% glenoid loss is a “critical level” at which this risk increases [Boileau P et al. J Bone Joint Surg Am 2006; Boileau P et al. Clin Orthop Relat Res 2014]. However, there is a paucity of data available to indicate whether a lesser degree of bone loss results in better arthroscopic outcomes.

Radiographic sclerotic contour loss in the identification of glenoid bone loss.

Quantification of glenoid bone loss guides surgical management in the setting of anterior shoulder instability. Glenoid defects resulting in ≥20% articular area loss require bony reconstruction. The objective of this study was to evaluate the utility of sclerotic glenoid contour loss on true anteroposterior radiography in the detection of varying quantities of simulated glenoid bone loss using a cadaveric model. Eight cadaveric scapulae with full radiographic sclerotic contour were osteotomized to produce glenoid surface area reductions of 10-50%. Radiography was performed initially and following each osteotomy, and assessed by an orthopedic surgeon and radiologist twice. Quantity of glenoid loss was compared using Fisher's exact test. Sensitivity, specificity, and reliability analyses were performed. On the first radiographic review, sclerotic contour loss was detected in 6 out of 8 scapulae with 50% area loss, but only 1 out of 8 scapulae with 20% area loss. There was a significantly higher proportion of radiographs containing sclerotic contour loss for defects with 50% area loss compared to those with 0-25% loss (p≤0.02). In the detection of ≥20% area loss, sclerotic contour loss had a sensitivity of 33-43% and specificity of 88-100%. Moderate inter-observer reliability (Cohen's kappa value of 0.42-0.53) and intra-observer reliability (kappa value of 0.46-0.58) were found. Radiographic sclerotic contour loss is commonly observed in radiographs of scapulae with 40-50% glenoid area loss and less often with smaller lesions. However, this finding lacks utility in discerning specific quantifications of glenoid bone loss. In a clinical setting, sclerotic contour loss suggests the presence of a large glenoid defect that may require bony reconstruction. However, an intact sclerotic contour does not rule out significant bone loss.

Bone Grafting in Shoulder Arthroplasty

Shoulder arthroplasty is one of the fastest-growing fields in orthopedic surgery. Deficiency of the glenoid or humeral bone stock is a major challenge that can result from degenerative arthritis, component loosening or extraction, fracture, or malignancy. Approximately 15% of primary reconstructions will require bone grafting, and the rate is higher for revisions. The authors present a systematic review of the current literature focused on the indications for and results of bone grafting techniques. This provides the practicing surgeon with a set of strategies to address bone loss in the primary and revision settings, whether using an anatomic or reverse design.

Diagnostic Accuracy of MRI in the Measurement of Glenoid Bone Loss

The purpose of this study is to assess the accuracy of MRI quantification of glenoid bone loss and to compare the diagnostic accuracy of MRI to CT in the measurement of glenoid bone loss. MRI, CT, and 3D CT examinations of 18 cadaveric glenoids were obtained after the creation of defects along the anterior and anteroinferior glenoid. The defects were measured by three readers separately and blindly using the circle method. These measurements were compared with measurements made on digital photographic images of the cadaveric glenoids. Paired sample Student t tests were used to compare the imaging modalities. Concordance correlation coefficients were also calculated to measure interobserver agreement. Our data show that MRI could be used to accurately measure glenoid bone loss with a small margin of error (mean, 3.44%; range, 2.06-5.94%) in estimated percentage loss. MRI accuracy was similar to that of both CT and 3D CT for glenoid loss measurements in our study for the readers familiar with the circle method, with 1.3% as the maximum expected difference in accuracy of the percentage bone loss between the different modalities (95% confidence). Glenoid bone loss can be accurately measured on MRI using the circle method. The MRI quantification of glenoid bone loss compares favorably to measurements obtained using 3D CT and CT. The accuracy of the measurements correlates with the level of training, and a learning curve is expected before mastering this technique.

3DMR osseous reconstructions of the shoulder using a gradient-echo based two-point Dixon reconstruction: a feasibility study

To create 3DMR osseous models of the shoulder similar to 3DCT models using a gradient-echo-based two-point/Dixon sequence. CT and 3TMR examinations of 7 cadaveric shoulders were obtained. Glenoid defects were created in 4 of the cadaveric shoulders. Each MR study included an axial Dixon 3D-dual-echo-time T1W-FLASH (acquisition time of 3 min/30 s). The water-only image data from the Dixon sequence and CT data were post-processed using 3D software. The following measurements were obtained on the shoulders: surface area (SA), height/width of the glenoid and humeral head, and width of the biceps groove. The glenoid defects were measured on imaging and compared with measurements made on en face digital photographs of the glenoid fossae (reference standard). Paired t tests/ANOVA were used to assess the differences between the imaging modalities. The differences between the glenoid and humeral measurements were not statistically significant (cm): glenoid SA 0.12 ± 0.04 (p = 0.45) and glenoid width 0.13 ± 0.06 (p = 0.06) with no difference in glenoid height measurement; humeral head SA 0.07 ± 0.12 (p = 0.42), humeral head height 0.03 ± 0.06 (p = 0.42), humeral head width 0.07 ± 0.06(p = 0.18), and biceps groove width 0.02 ± 0.01 (p = 0.07). The mean/standard deviation difference between the reference standard and 3DMR measurements was 0.25 ± 0.96 %/0.30 ± 0.14 mm; 3DCT 0.25 ± 0.96 /0.75 ± 0.39 mm. There was no statistical difference between the measurements obtained on 3DMR and 3DCT (percentage, p = 0.45; mm, p = 0.20). Accurate 3D osseous models of the shoulder can be produced using a 3D two-point/Dixon sequence and can be added to MR examinations with a minor increase in imaging time, used to quantify glenoid loss, and may eliminate the need for pre-surgical CT examinations.

Surgical treatment of significant glenoid bone defects and associated humeral avulsions of glenohumeral ligament (HAGL) lesions in anterior shoulder instability

Combined occurrence of humeral avulsion of glenohumeral ligament (HAGL) lesion and a significant glenoid bone defect is an unusual and previously undescribed association in traumatic anterior shoulder instability. The purpose of this study was (1) to report a retrospective case series of seven anterior bony instability patients who were diagnosed with this unusual association and (2) to evaluate the results of a modified Latarjet procedure and simultaneous HAGL repair using a new subscapularis-sparing approach. A retrospective review of the records of 64 anterior shoulder instability patients who underwent bony stabilization surgery was performed, and patients who underwent a combined reconstruction for significant glenohumeral bone defects (glenoid loss >20 %) and an associated HAGL lesion were identified. Pre- and postoperative follow-up clinical parameters and functional scores were documented (Oxford shoulder instability score [OSIS], Western Ontario shoulder instability index [WOSI]), Rowe score). Radiological assessment included measurement of the glenoid bone defect (CT scan) and evaluation of soft tissue lesions (MR arthrogram). Radiological and arthroscopic evaluation confirmed the combined lesion complex in 7 (11 %) patients. Follow-up evaluation (mean 20.6 months) suggested an excellent outcome (Rowe score: median 95, range 95-100); a statistically significant improvement was seen in the follow-up OSIS (median 12, range 12-14, p = 0.018) and WOSI score (median 28, range 17-102, p = 0.018) as compared to the preoperative score (median OSIS 50, range 32-53; median WOSI 1,084, range 919-1,195). Clinical tests for subscapularis function revealed a functional subscapularis muscle; no significant differences were detected in pre- versus postoperative internal rotation strength and in the operated versus normal contralateral shoulder (ns). The dual-window subscapularis-sparing approach provided adequate exposure for combined reconstruction of the humeral and glenoid lesions, and no complications were encountered. Significant glenoid defects are associated with HAGL lesions in approximately 1/10th of patients with bony instability. Combined reconstruction of these lesions via a subscapularis-sparing approach results in an excellent outcome and significant improvement in functional scores at a medium-term follow-up. Therapeutic study, Level IV.