Management of Glenoid Bone Loss in Shoulder Instability: Where We Are in 2023.

The management of glenoid bone loss in shoulder instability can be challenging. Although shoulder instability can often be managed with arthroscopic soft-tissue procedures alone, the extent of glenoid bone loss and bipolar bone defects may require bone augmentation procedures for restoration of stability. In this setting, patient evaluation, examination, treatment options, and surgical pearls are vital. Furthermore, a treatment algorithm is established to guide both indications and the technical application of procedures including Bankart repair with remplissage, Latarjet procedure, and glenoid bone graft options. The limitations, complications, and current research pertinent to each treatment assist in guiding treatment.

Robert H. Cofield, MD, Award for Best Oral Presentation 2023: Up to 8 mm of glenoid-sided lateralization does not increase the risk of acromial or scapular spine stress fracture following reverse shoulder arthroplasty with a 135° inlay humeral component.

BACKGROUND: Glenoid-sided lateralization in reverse shoulder arthroplasty (RSA) decreases bony impingement and improves rotational range of motion, but has been theorized to increase the risk of acromial or scapular spine fractures (ASFs). The purpose of this study was to assess if glenoid-sided lateralization even up to 8 mm increases the risk for stress fracture following RSA with a 135° inlay humeral component. METHODS: A retrospective review was performed from a multicenter prospectively collected database on patients who underwent primary RSA from 2015 to 2021. All RSAs were performed with a 135° inlay humeral component. Varying amounts of glenoid lateralization were used from 0 to 8 mm. Preoperative radiographs were reviewed for the presence of acromial thinning, acromiohumeral distance (AHD), and inclination. Postoperative implant position (distalization, lateralization, and inclination) as well as the presence of ASF was evaluated on minimum 1-year postoperative radiographs. Regression analyses were performed on component and clinical variables to assess for factors predictive of ASF. RESULTS: Acromial or scapular spine fractures were identified in 26 of 470 shoulders (5.5%). Glenoid-sided lateralization was not associated with ASF risk (P = .890). Furthermore, the incidence of fracture did not vary based on glenoid-sided lateralization (0-2 mm, 7.4%; 4 mm, 5.6%; 6 mm, 4.4%; 8 mm, 6.0%; P > .05 for all comparisons). RSA on the dominant extremity was predictive of fracture (odds ratio [OR] 2.21, 95% confidence interval [CI] 1.20-5.75; P = .037), but there was no relationship between patient age, sex, preoperative acromial thinning, or diagnosis and risk of fracture. Although there was no difference in mean postoperative AHD between groups (P = .443), the pre- to postoperative delta AHD was higher in the stress fracture group (2.0 ± 0.7 cm vs. 1.7 ± 0.7 cm; P = .015). For every centimeter increase in delta AHD, there was a 121% increased risk for fracture (OR 2.21, 95% CI 1.33-3.68; P = .012). Additionally, for every 1-mm increase in inferior glenosphere overhang, there was a 19% increase in fracture risk (P = .025). CONCLUSION: Up to 8 mm of glenoid-sided metallic lateralization does not appear to increase the risk of ASF when combined with a 135° inlay humeral implant. Humeral distalization increases the risk of ASF, particularly when there is a larger change between pre- and postoperative AHD or higher inferior glenosphere overhang. In cases of pronounced preoperative superior humeral migration, it may be a consideration to avoid excessive postoperative distalization, but minimizing bony impingement via glenoid-sided lateralization appears to be safe.

Posteroinferior glenosphere positioning is associated with improved range of motion following reverse shoulder arthroplasty with a 135° inlay humeral component and lateralized glenoid.

BACKGROUND: Optimal glenosphere positioning in a lateralized reverse shoulder arthroplasty (RSA) to maximize functional outcomes has yet to be clearly defined. Center of rotation (COR) measurements have largely relied on anteroposterior radiographs, which allow assessment of lateralization and inferior position, but ignore scapular Y radiographs, which may provide an assessment of the posterior and inferior position relative to the acromion. The purpose of this study was to evaluate the COR in the sagittal plane and assess the effect of glenosphere positioning with functional outcomes using a 135° inlay stem with a lateralized glenoid. METHODS: A retrospective review was performed on a prospectively maintained multicenter database on patients who underwent primary RSA from 2015 to 2021 with a 135° inlay stem. The COR was measured on minimum 2-year postoperative sagittal plain radiographs using a best-fit circle fit method. A best-fit circle was made on the glenosphere and the center was marked. From there, 4 measurements were made: (1) center to the inner cortex of the coracoid, (2) center to the inner cortex of the anterior acromion, (3) center to the inner cortex of the middle acromion, and (4) center to the inner cortex of the posterior acromion. Regression analysis was performed to evaluate any association between the position of the COR relative to bony landmarks with functional outcomes. RESULTS: A total of 136 RSAs met the study criteria. There was no relation with any of the distances with outcome scores (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, visual analog scale). In regard to range of motion (ROM), each distance had an effect on at least 1 parameter. The COR to coracoid distance had the broadest association with ROM, with improvements in forward flexion (FF), external rotation (ER0), and internal rotation with the arm at 90° (IR90) (P < .001, P = .031, and P < .001, respectively). The COR to coracoid distance was also the only distance to affect the final FF and IR90. For every 1-mm increase in this distance, there was a 1.8° increase in FF and 1.5° increase in IR90 (ß = 1.78, 95% confidence interval [CI] 0.85-2.72, P < .001, and ß = 1.53, 95% CI 0.65-2.41, P < .001; respectively). CONCLUSION: Evaluation of the COR following RSA in the sagittal plane suggests that a posteroinferior glenosphere position may improve ROM when using a 135° inlay humeral component and a lateralized glenoid.

Physician Professional Fees Are Declining and Inpatient and Outpatient Facility Fees Are Increasing for Orthopaedic Procedures in the United States.

PURPOSE: To examine the trends in physician professional fees and inpatient and outpatient facility fees in orthopaedic surgery in the United States. METHODS: Physician professional fees and inpatient and outpatient facility fees were tracked from 2008 to 2021 for the most common orthopaedic procedures in each orthopaedic subspecialty. Using common procedure codes for physician and outpatient procedures and Medicare severity diagnosis related group codes for inpatient procedures, the Medicare Physician Fee Schedules were used to obtain the national payment amounts for physician professional fees and inpatient and outpatient facility fees. Trends in fees were tracked over time after adjustment for inflation. RESULTS: From 2008 to 2021, physician professional fees decreased by an average of 20%, whereas inpatient facility fees increased by 15%, and outpatient facility fees increased by 72%. The orthopaedic subspecialty with the largest decrease in physician professional fees was oncology, with an average decrease of 23.5%, followed by general orthopaedics (23.1%), and sports medicine (22.8%). The largest increase in outpatient facility fees was seen in the subspecialties of general orthopaedics (149.8%), spine (130.1%), and trauma (123.0%). CONCLUSIONS: Over the past 13 years, physician professional fees for the most common orthopaedic procedures have declined while inpatient and outpatient facility fees have increased. Understanding these changes is important to the practice of orthopaedic surgery in the United States. LEVEL OF EVIDENCE: IV, economic.

Stemless components lead to improved radiographic restoration of humeral head anatomy compared with short-stemmed components in total shoulder arthroplasty.

BACKGROUND: Restoring the native center of rotation (COR) in total shoulder arthroplasty (TSA) has been shown to improve postsurgical function, subjective outcomes, and implant longevity. The primary purpose of this study was to compare postoperative radiographic restoration of the humeral COR between short-stem and stemless humeral implants by evaluating the mean COR shift between the 2 techniques. Secondary outcomes evaluated were comparisons of COR shift outliers, humeral head implant thickness and diameter, direction of COR shift, and neck-shaft angle (NSA). METHODS: This study was a multicenter retrospective comparative study using a consecutive series of primary anatomic TSA patients who received either a short-stem or stemless humeral implant. Radiographically, COR and NSA were measured by 2 fellowship-trained surgeons using the best-fit circle technique on immediate postoperative Grashey radiographs. RESULTS: A total of 229 patients formed the final cohort for analysis that included 89 short stems and 140 stemless components. The mean COR shift for short stems was 2.7 mm (±1.4 mm) compared with 2.1 mm (±0.9 mm) for stemless implants (P < .001). The percentage of short-stem implant patients with a >2 mm COR difference from native was 66.0% (n = 62) compared with 47.4% (n = 64) for stemless (P = .006). The percentage of short-stem patients with a >4 mm COR difference from native was 17.0% (n = 16) compared with 3.0% (n = 4) for stemless (P < .001). The mean humeral implant head thickness for short stems was 18.7 ± 2.2 mm compared with 17.2 ± 1.3 mm for stemless implants (P < .001). The mean humeral head diameter for short stems was 48.7 ± 4.4 mm compared with 45.5 ± 3.5 mm for stemless implants (P < .001). The NSA for the short-stem cohort was 136.7° (±3.6°) compared with 133.5° (±6.0°) for stemless (P < .001). CONCLUSIONS: Stemless prostheses placed during TSA achieved improved restoration of humeral head COR and were less likely to have significant COR outliers compared with short-stem implants.

Short-term clinical and radiographic outcomes of a hybrid all-polyethylene glenoid based on preoperative glenoid morphology.

BACKGROUND: The primary purpose of this study was to compare 2-year anatomic total shoulder arthroplasty (TSA) functional and radiographic outcomes between Walch type A and B glenoids treated with an all-polyethylene glenoid designed for hybrid fixation with peripheral cement and central osseous integration. The secondary purpose was to evaluate outcomes based on central peg technique. The hypotheses were that there would be no difference in short-term radiographic or functional outcome scores based on preoperative glenoid morphology or central peg technique. METHODS: We performed a multicenter retrospective review of patients who underwent TSA with the same hybrid all-polyethylene glenoid and had minimum 2-year follow-up. Patient-reported outcomes and radiographic outcomes were analyzed based on preoperative Walch morphology and central peg technique. Radiographic analysis included preoperative glenoid morphology; preoperative and postoperative glenoid version, glenoid inclination, and posterior humeral head subluxation; and postoperative glenoid radiolucencies according to the Wirth and Lazarus classifications. RESULTS: A total of 266 patients with a mean age of 64.9 ± 8.2 years were evaluated at a mean of 28 months postoperatively. Postoperatively, there were significant improvements in all functional outcome measures (P < .001), range-of-motion measures (forward elevation, external rotation at 0°, external rotation at 90°, internal rotation by spinal level, and internal rotation at 90°; P < .001), and strength measures (Constant, external rotation, and modified belly press; P < .001). There were no clinically meaningful differences in functional outcomes or statistically significant differences in radiographic appearance between Walch type A and B glenoids. Subgroup analysis revealed that glenoids with a cemented central peg had the worst radiographic outcomes based on Lazarus scoring. CONCLUSION: Patients undergoing TSA with a hybrid in-line pegged glenoid have excellent clinical outcomes at short-term follow-up regardless of preoperative glenoid morphology. Different central peg techniques do not appear to play a significant role in the risk of glenoid component lucencies at 2 years postoperatively.

A comprehensive evaluation of the association of radiographic measures of lateralization on clinical outcomes following reverse total shoulder arthroplasty.

BACKGROUND: Although reverse total shoulder arthroplasty (RTSA) has excellent reported outcomes and satisfaction, patients often have postoperative limitations in range of motion (ROM), specifically internal rotation. Increased lateralization is thought to improve ROM following RTSA. The purpose of this study was to evaluate the association between radiographic measurements of lateralization and postoperative ROM and clinical outcome scores following RTSA. The authors hypothesized that increased radiographic lateralization would be associated with improved postoperative ROM, specifically internal rotation, but have no significant association with clinical outcome scores. METHODS: Patients who underwent RTSA with a 135° neck-shaft angle prosthesis and minimum 2-year clinical and radiographic follow-up were included and retrospectively reviewed. Postoperative radiographs were evaluated for several lateralization measurements including the lateralization shoulder angle (LSA), distance from the lateral border of the acromion to the lateral portion of the glenosphere, distance from the glenoid to the most lateral aspect of the greater tuberosity, and the distance from the lateral aspect of the acromion to the most lateral aspect of the greater tuberosity. Linear regression analyses were used to evaluate the independent association of each radiographic measurement of lateralization on forward flexion, external rotation, internal rotation, and the American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) index score at 2 years postoperation. Receiver operating characteristic (ROC) curves were constructed to identify significant thresholds of each radiographic lateralization measurement. RESULTS: A total of 203 patients were included. For internal rotation, a greater LSA (P = .007), shorter acromion to glenosphere distance (meaning more glenoid lateralization) (P = .005), and a greater acromion to greater tuberosity distance (with the tuberosity more lateral to the acromion) (P = .021) were associated with improved internal rotation. Overall, ROC analysis demonstrated very little significant data, the most notable of which was the LSA, which had a significant cutoff of 82° (sensitivity 57%, specificity 68%, P = .012). CONCLUSION: Of the numerous radiographic measures of lateralization after RTSA, the LSA is the most significantly associated with outcomes, including improved internal rotation and a decrease in forward flexion and ASES score. The clinical significance of these statistically significant findings requires further study, as the observed associations were for very small changes that may not represent clinical significance.

Glenoid lateralization influences active internal rotation after reverse shoulder arthroplasty.

BACKGROUND: Improvement in internal rotation (IR) is not reliably achieved after reverse total shoulder arthroplasty (RSA). The purpose of this study was to evaluate the relationship between postoperative IR and glenoid-sided lateralization following RSA in an implant using metallic lateralization. METHODS: A multicenter retrospective study of RSAs with minimum 1-year clinical follow-up was performed. Patients were stratified based on the amount of glenoid-sided implant lateralization into 4 groups: 0-2 mm (n = 57), 4 mm (n =238), 6 mm (n = 95), and 8 mm (n = 65). The primary study outcome was active IR at a minimum of 1 year postoperatively, measured both by spinal level and in degrees with the shoulder abducted to 90°. Secondary outcomes were active forward flexion and external rotation, belly press strength, and subjective patient-reported outcome (PRO) measures. Comparisons were made with 1-way analyses of variance. Linear regression analyses evaluating for the association of glenoid lateralization with active IR were also performed to control for additional confounders, including demographics and other implant variables such as glenosphere diameter, humeral lateralization, humeral version, and whether the subscapularis was repaired. RESULTS: A total of 455 patients were included in the study. The mean age was 69 years, and 48% of patients were male. IR differences varied by the method of measurement (spinal level vs. IR in degrees with arm abducted). Overall, patients with 8 mm of glenoid lateralization had significantly improved IR compared with all other lateralization groups. Patients with 6 mm of glenoid lateralization had significantly improved IR compared with the 0-2- and 4-mm groups. There were no significant differences in the secondary outcomes or PROs between lateralization groups. In the regression analysis, glenoid lateralization was the only implant-related variable that was significantly associated with improved IR for both measurement methods. Glenosphere diameter and humeral version were both significantly associated with IR measured in degrees with the arm abducted but not spinal level. CONCLUSIONS: For the studied implant system, glenoid lateralization of 6-8 mm was associated with improved active IR at 1 year compared to patients with less glenoid lateralization with no significant differences in active forward flexion, external rotation, or PROs. In a multivariable analysis, increased humeral retroversion was associated with increased IR at 90° and increasing glenosphere diameter was associated with decreased IR at 90°, whereas BMI, subscapularis repair, and humeral lateralization did not significantly affect active IR.

Does commercially available shoulder arthroplasty preoperative planning software agree with surgeon measurements of version, inclination, and subluxation?

BACKGROUND: Preoperative planning with commercially available imaging software in shoulder arthroplasty may allow for improved decision-making and more accurate placement of the glenoid component. METHODS: A total of 81 consecutive shoulder computed tomography scans obtained for preoperative planning purposes for shoulder arthroplasty were analyzed by commercially available software from 4 companies (Blueprint: Wright Medical, Memphis, TN, USA; GPS: Exactech, Gainesville, FL, USA; Materialise: DJO, Vista, CA, USA; and VIP: Arthrex, Naples, FL, USA) and by 5 fellowship-trained sports medicine/shoulder surgeons. Inclination, version, and subluxation of the humerus were measured in a blinded fashion on axial and coronal sequences at the mid-glenoid. Surgeon measurements were analyzed for agreement and were compared with the 4 commercial programs. RESULTS: Surgeon reliability was acceptable for version (intraclass correlation coefficient [ICC]: 0.876), inclination (ICC: 0.84), and subluxation (ICC: 0.523). Significant differences were found between surgeon and commercial software measurements in version (P = .03), inclination (P = .023), and subluxation (P < .001). Software measurements tended to be more superiorly inclined (average -2° to 2° greater), more retroverted (average 2°-5° greater), and more posteriorly subluxed (average 7°-10° greater) than surgeon measurements. In comparing imaging software measurements, only Blueprint was found to produce significantly different version measurements than surgeon measurements (P = .02). CONCLUSION: Preoperative planning software for shoulder arthroplasty has limited agreement in measures of version, inclination, and subluxation measurements, whereas surgeons have high inter-reliability. Surgeons should be cautious when using commercial software planning systems and when comparing publications that use different planning systems to determine preoperative glenoid deformity measurements.

Histologic case series of human acellular dermal matrix in superior capsule reconstruction.

BACKGROUND: Acellular dermal matrix (ADM) allografts are commonly used in the surgical treatment of complex and irreparable rotator cuff tears. Multiple studies report that superior capsule reconstruction (SCR) using ADM has resulted in short-term clinical success as assessed via radiographic and patient-reported outcomes. However, limited information is available regarding the biologic fate of these grafts in human subjects. This case series describes histologic results from 8 patients who had reoperations, during which the previously implanted ADMs were removed. These explanted ADMs were subjected to histologic analysis with the hypothesis that they would have evidence of recellularization, revascularization, and active remodeling. METHODS: Eight patients, 38-82 years old, underwent reoperation 6-38 months after undergoing SCR. ADM explants were voluntarily shipped to the manufacturer for histologic analysis. Each graft's structure and composition were qualitatively evaluated by 1 or more of the following histologic stains: hematoxylin and eosin, safranin O, and Russell-Movat pentachrome. Pan-muscle actin staining also assessed the level of neovascularization, potential myoblast or myocyte infiltration, and muscle tissue development in the graft, and was analyzed to determine the proportion of graft that had been recellularized in situ. RESULTS: Grafts showed varying levels of gross and microscopic incorporation with the host. An uneven, but high, overall degree of recellularization, revascularization, and active remodeling was observed. The degree of remodeling correlated with implant duration. These results are consistent with successful biologic reconstruction of the superior shoulder capsule. CONCLUSIONS: The present histologic analysis suggests that ADMs used in SCR undergo active recellularization, revascularization, and remodeling as early as 6 months after implantation, and that graft recellularization positively correlates with duration of implantation. These results represent a significant advancement in our knowledge regarding biologic incorporation of ADMs used in SCR.

Short-term evaluation of humeral stress shielding following reverse shoulder arthroplasty using press-fit fixation compared with cemented fixation.

BACKGROUND: The purpose of this study was to compare the functional outcomes and humeral stress shielding of a reverse shoulder arthroplasty (RSA) placed with either cement or press-fit fixation. The hypothesis was that there would be no difference in functional outcomes or stress shielding. METHODS: We performed a multicenter retrospective review of primary RSAs performed with standard-length stems. The stems were identical in geometry and coating with the only variable being whether the stems were secured with cement or by a press-fit technique. The functional outcomes and radiographs of 93 press-fit stems and 26 cemented stems were reviewed at a minimum of 2 years postoperatively. RESULTS: Significant improvements were noted in all ranges of motion and functional outcomes from baseline (P < .001), but no difference was found between the groups (P > .05). Calcar osteolysis was seen in 43% of press-fit and 58% of cemented stems (P = .266). Proximal lateral stress shielding was more common in the press-fit group (68%) than in the cemented group (25%) (P = .045). Adaptive changes were considered low in 97% of press-fit stems, and there were no cases of tuberosity resorption. No evidence of loosening or humeral component shift was noted in either group. CONCLUSION: At short-term follow-up, no differences in functional outcomes or stem loosening were found between press-fit fixation and cemented fixation of an RSA humeral stem. Proximal stress shielding was more common with press-fit fixation with the stem in this study, but the overall changes were considered low in 97% of cases. Further study is needed to evaluate the mid- to long-term differences regarding stress shielding.

Can a functional difference be detected in reverse arthroplasty with 135° versus 155° prosthesis for the treatment of rotator cuff arthropathy: a prospective randomized study.

BACKGROUND: The purpose of this randomized controlled trial was to compare humeral inclinations of 135° and 155° in patients undergoing primary reverse shoulder arthroplasty (RSA). Our hypothesis was that forward flexion would be higher in the 155° group but be associated with a higher rate of scapular notching. METHODS: A randomized controlled trial was conducted on 100 primary RSAs performed with a humeral inclination of either 135° or 155°. The prostheses were otherwise identical and a neutral glenosphere was used in all cases. Functional outcome, forward flexion, external rotation, and scapular notching were assessed at a minimum of 2 years postoperatively. RESULTS: There was no difference in range of motion or functional outcome scores between the 2 groups. In the 155° group, forward flexion improved from 76° to 135° (P < .001) and external rotation remained unchanged (29° vs. 30°; P = .835). In the 135° group, postoperative forward flexion improved from 78° to 132° (P < .001) and external rotation was unchanged (28° vs. 29°; P = .814). Scapular notching was observed in 58% of cases with a 155° inclination compared with 21% with a 135° inclination (P = .009). CONCLUSION: With a neutral glenosphere there was no difference in postoperative forward flexion or external rotation after an RSA with a humeral inclination of 135° compared with 155°. Scapular notching was reduced with the use of 135° design compared with a 155° design but persists at a rate of 21% at 2-year follow-up in the absence of a lateralized glenosphere.

Triple-Loaded Suture Anchors Versus a Knotless Rip Stop Construct in a Single-Row Rotator Cuff Repair Model.

PURPOSE: To compare the biomechanical properties of single-row repair with triple-loaded (TL) anchor repair versus a knotless rip stop (KRS) repair in a rotator cuff repair model. METHODS: Rotator cuff tears were created in 8 cadaveric matched-pair specimens and repaired with a TL anchor or KRS construct. In the TL construct, anchors were placed in the greater tuberosity and then all suture limbs were passed through the rotator cuff as simple sutures and tied. In the KRS construct, a 2-mm suture tape was passed through the tendon in an inverted mattress fashion, and a free suture was passed medial to the suture tape to create a rip-stop. Then, the suture tape and free suture were secured with knotless anchors. Displacement was observed with video tracking after cyclic loading, and specimens were loaded to failure. RESULTS: The mean load to failure was 438 ± 59 N in TL anchor repairs compared with 457 ± 110 N in KRS repairs (P = .582). The mean displacement with cyclic loading was 3.8 ± 1.6 mm in TL anchor repairs versus 4.3 ± 1.8 mm in the KRS group (P = .297). Mode of failure was consistent in both groups, with 6 of 8 failures in the TL anchor group and 7 of 8 failures in KRS group occurring from anchor pullout. CONCLUSIONS: There is no statistical difference in load to failure and cyclic loading between TL anchor and KRS single-row repair techniques. CLINICAL RELEVANCE: KRS repair technique may be an alternative method of repairing full-thickness supraspinatus tendon tears with a single-row construct.

The Glenoid Labral Articular Teardrop Lesion: A Chondrolabral Injury With Distinct Magnetic Resonance Imaging Findings.

PURPOSE: Evaluation and description of a pathognomonic lesion identified on magnetic resonance imaging (MRI) of a chondrolabral injury of the glenohumeral joint. METHODS: Patients were prospectively identified at the time of MRI by a characteristic teardrop appearance of a pedicled displaced chondrolabral flap in the axillary recess on coronal imaging and retrospectively reviewed. RESULTS: In a sample of 36 patients, there were 30 males (83%), and the average age was 27 years (14-75 years). Twenty-four (67%) were noted to have sustained an instability episode or had findings of instability on physical examination; 19 patients (53%) were playing a sport at the time of injury. The characteristic teardrop lesion measured 3.36 mm (1-9 mm) in the coronal plane, 6.98 mm (2-20 mm) sagittal and 11.78 mm (1-25 mm) longitudinal. The lesion was located in the anterior inferior quadrant of the glenoid. CONCLUSIONS: The glenoid labral articular teardrop (GLAT) lesion represents a pathognomonic lesion in the spectrum of chondral labral injury, indicating articular cartilage damage to the glenoid. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Stress shielding of the humerus in press-fit anatomic shoulder arthroplasty: review and recommendations for evaluation.

Uncemented press-fit humeral stems were developed with the goal of decreasing operative time, preserving bone stock, and easing revision. In recent years, short stems and stemless humeral implants have also become available. These press-fit humeral implants have varying designs that can lead to changes in stress distribution in the proximal humerus. Such stress shielding manifests as bony adaptations and may affect long-term functional outcome and the ability to perform revision. However, current studies of humeral fixation during total shoulder arthroplasty are complicated because a variety of classification systems have been used to report findings. The purpose of this report is to review the current literature on press-fit fixation of the humeral component during total shoulder arthroplasty and propose minimum requirements for radiographic descriptions of stress shielding.

Radiographic changes differ between two different short press-fit humeral stem designs in total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to compare the radiographic changes of the humerus in the short term after total shoulder arthroplasty with two different short-stem humeral components. The hypothesis was that there would be no difference in radiographic changes or functional outcome based on component type. METHODS: A retrospective review was conducted of primary total shoulder arthroplasties performed with a short press-fit humeral component. Group A included a collarless humeral stem with an oval geometry and curved stem (Ascend or Ascend Flex; Wright Medical, Memphis, TN, USA). Group B included a humeral stem with a metaphyseal collar, rectangular geometry, and straight stem (Apex; Arthrex, Inc., Naples, FL, USA). Radiographic changes and functional outcome were evaluated at a minimum of 2 years postoperatively. RESULTS: There were 42 patients in group A and 35 patients in group B available for analysis. There was no difference in functional outcome between the groups. In group A, the mean total radiographic change score of the humerus was 3.9, with changes classified as low in 38% and high in 62%. In group B, the mean total radiographic change score of the humerus was 2.5, with changes classified as low in 77% and high in 23% (P < .001). Medial calcar osteolysis was present in 71% of group A compared with 28.5% of group B (P < .001). CONCLUSION: At short-term follow-up, there is no difference in functional outcome or revision between 2 different humeral stem designs. However, bone adaptive changes and the rate of medial calcar osteolysis are significantly different.

Short-term clinical outcome of an anatomic short-stem humeral component in total shoulder arthroplasty.

BACKGROUND: Short-stem press-fit humeral components have recently been developed in an effort to preserve bone in total shoulder arthroplasty (TSA), but few studies have reported outcomes of these devices. The purpose of this study was to evaluate the short-term clinical outcomes of an anatomic short-stem humeral component in TSA. We hypothesized that the implant would lead to significant functional improvement with low rates of radiographic loosening. METHODS: A multicenter retrospective review was performed of TSAs using an anatomic short-stem humeral component (Apex; Arthrex, Inc., Naples, FL, USA). The minimum follow-up was 2 years. Functional outcome was evaluated according to the American Shoulder and Elbow Surgeons score, Visual Analog Scale for pain, Single Assessment Numeric Evaluation, Simple Shoulder Test, and range of motion. A radiographic analysis was performed to evaluate component loosening. RESULTS: Sixty-four patients with a mean age of 64.1 years were available for follow-up at a mean of 25 months postoperatively. There were significant improvements in the Visual Analog Scale (6 to 2; P < .001), Simple Shoulder Test (4 to 10; P < .001), Single Assessment Numeric Evaluation (32 to 84; P < .001), and American Shoulder and Elbow Surgeons (37 to 80; P < .001) scores. Forward flexion improved from 116° to 148° (P < .001), external rotation improved from 30° to 57° (P < .001), and internal rotation improved from an average spinal level of S1 to L2 (P < .001). On radiographic examination, 9% of stems were deemed at risk for loosening, but there was no gross loosening in any patient. CONCLUSIONS: TSA with an anatomic press-fit short-stem humeral component is associated with significant improvements in clinical outcomes, without evidence of component loosening at short-term follow-up.

Proximal stress shielding is decreased with a short stem compared with a traditional-length stem in total shoulder arthroplasty.

BACKGROUND: This study compared the outcome and radiographic humeral adaptations after placement of a traditional-length (TL) or short-stem (SS) humeral component during total shoulder arthroplasty (TSA). The hypothesis was there would be no difference in outcome or radiographic adaptations. METHODS: A multicenter retrospective review was performed of primary TSAs performed with a TL or SS press-fit humeral component. The stems were identical in geometry and coating, with the only variable being stem length. Functional outcome and radiographs were reviewed at a minimum of 2 years postoperatively in 58 TL stems and 56 SSs. RESULTS: There were significant improvements in all range of motion and functional outcome from baseline (P < .001) but no difference between the groups (P > .05). TL stems were placed in anatomic alignment 98% of the time compared with 86% of the SS cases (P = .015), but alignment did not influence outcome. Cortical thinning was more common in the medial metaphysis with the TL stem (74%) than with the SS (50%; P = .008). Partial calcar osteolysis was seen in 31% of TL stems and in 23% of SSs (P = .348). There was no difference in loosening or shift between the 2 groups. CONCLUSION: There is no difference in functional outcome at short-term follow-up between a TL stem and a SS in TSA. The pattern of radiographic adaptations may differ based on stem length. Further study is needed to evaluate the mid- to long-term differences, particularly with regard to calcar osteolysis.

Coracoid bypass procedure: surgical technique for coracoclavicular reconstruction with coracoid insufficiency.

BACKGROUND: Failed acromioclavicular (AC) joint reconstruction secondary to a coracoid fracture or insufficiency of the coracoid is an uncommon but challenging clinical situation. We describe a surgical technique of revision coracoclavicular (CC) reconstruction, the coracoid bypass procedure, and report short-term results with this technique in 3 patients. METHODS: In the coracoid bypass procedure, reconstruction of the CC ligaments is performed by passing a tendon graft through a surgically created bone tunnel in the scapular body (inferior to the base of the coracoid) and then fixing the graft around the clavicle or through bone tunnels in the clavicle. Three patients treated with this technique were retrospectively reviewed. RESULTS: AC joint reconstruction performed for a traumatic AC joint separation failed in the 3 patients reported in this series. The previous procedures were an anatomic CC reconstruction in 2 patients and a modified Weaver-Dunn procedure in 1 patient. The coracoid fractures were detected postoperatively, and the mean interval from the index surgery to the coracoid bypass procedure was 8 months. The patients were a mean age of 44 years, and average follow-up was 21 months. At the last follow-up, all 3 patients were pain free, with full range of shoulder motion, preserved CC distance, and a stable AC joint. CONCLUSION: The coracoid bypass procedure is a treatment option for CC joint reconstruction during revision AC joint surgery in the setting of a coracoid fracture or coracoid insufficiency.

Healing and functional outcome of a subscapularis peel repair with a stem-based repair after total shoulder arthroplasty.

BACKGROUND: The purpose of this study was to evaluate functional outcome and healing of a subscapularis peel with a stem-based repair after total shoulder arthroplasty (TSA). The hypothesis was that the repair would lead to subscapularis healing in the majority of cases. METHODS: A prospective analysis was performed on a consecutive series of TSAs. Range of motion and functional outcome were assessed according to American Shoulder and Elbow Surgeons, Single Assessment Numeric Evaluation, Simple Shoulder Test, and visual analog scale scores at a minimum follow-up of 1 year. Belly-press and lift-off tests were also performed. An ultrasound evaluation assessed subscapularis healing at final follow-up. RESULTS: At a mean follow-up of 15 months, 60 patients (mean age, 64 years) were examined. Mean forward flexion improved from 115° to 137°. External rotation at the side improved from 27° to 52°, and internal rotation improved from L4 to L2 (P < .05). American Shoulder and Elbow Surgeons score improved from 34.3 to 79.8 (P < .001). Likewise, the Single Assessment Numeric Evaluation and Simple Shoulder Test scores showed significant improvement from 33.1 to 85.3 and 4.3 to 10.2, respectively (P < .001). The visual analog scale score for pain decreased from 5.8 to 0.7 (P < .001). On ultrasound examination, the subscapularis was healed intact in 55 cases (91.7%), attenuated in 3 cases (5%), and torn in 2 cases (3.3%). CONCLUSION: A stem-based repair of a subscapularis peel after TSA leads to functional improvement in the majority of cases with >90% postoperative healing of the subscapularis.