Angled BIO-RSA (bony-increased offset-reverse shoulder arthroplasty): a solution for the management of glenoid bone loss and erosion

Is preoperative 3D planning reliable for predicting postoperative clinical differences in range of motion between two stem designs in reverse shoulder arthroplasty

BACKGROUND

We aim to predict a clinical difference in the postoperative range of motion (RoM) between 2 reverse shoulder arthroplasty (RSA) stem designs (Inlay-155° and Onlay-145°) using preoperative planning software. We hypothesized that preoperative 3D planning could anticipate the differences in postoperative clinical RoM between 2 humeral stem designs and by keeping the same glenoid implant.

METHODS

Thirty-seven patients (14 men and 23 women, 76 ± 7 years) underwent a BIO-RSA (bony increased offset-RSA) with the use of preoperative planning and an intraoperative 3-dimensional-printed patient-specific guide for glenoid component implantation between January 2014 and September 2019 with a minimum follow-up of 2 years. Two types of humeral implants were used: Inlay with a 155° inclination (Inlay-155°) and Onlay with a 145°inclination (Onlay-145°). Glenoid implants remained unchanged. The postoperative RSA angle (inclination of the area in which the glenoid component of the RSA is implanted) and the lateralization shoulder angle were measured to confirm the good positioning of the glenoid implant and the global lateralization on postoperative X-rays. A correlation between simulated and clinical RoM was studied. Simulated and last follow-up active forward flexion (AFE), abduction, and external rotation (ER) were compared between the 2 types of implants.

RESULTS

No significant difference in RSA and lateralization shoulder angle was found between planned and postoperative radiological implants' position. Clinical RoM at the last follow-up was always significantly different from simulated preoperative RoM. A low-to-moderate but significant correlation existed for AFE, abduction, and ER (r = 0.45, r = 0.47, and r = 0.57, respectively; P < .01). AFE and abduction were systematically underestimated (126° ± 16° and 95° ± 13° simulated vs. 150° ± 24° and 114° ± 13° postoperatively; P < .001), whereas ER was systematically overestimated (50° ± 19° simulated vs. 36° ± 19° postoperatively; P < .001). Simulated abduction and ER highlighted a significant difference between Inlay-155° and Onlay-145° (12° ± 2°, P = .01, and 23° ± 3°, P < .001), and this was also retrieved clinically at the last follow-up (23° ± 2°, P = .02, and 22° ± 2°, P < .001).

CONCLUSIONS

This study is the first to evaluate the clinical relevance of predicted RoM for RSA preoperative planning. Motion that involves the scapulothoracic joint (AFE and abduction) is underestimated, while ER is overestimated. However, preoperative planning provides clinically relevant RoM prediction with a significant correlation between both and brings reliable data when comparing 2 different types of humeral implants (Inlay-155° and Onlay-145°) for abduction and ER. Thus, RoM simulation is a valuable tool to optimize implant selection and choose RSA implants to reach the optimal RoM.

Clinical and Radiographic Outcomes and Graft Incorporation Rate Assessed by CT Scan After Reverse Shoulder Arthroplasty With Glenoid Structural Bone Graft Reconstruction

INTRODUCTION

Reverse total shoulder arthroplasty (RTSA) with structural bone graft has been described as a technique in addressing glenoid bony defects. Studies have demonstrated acceptable outcomes with structural autograft or allograft. However, most of these studies are relatively small and rarely evaluate bone graft incorporation with CT scan. The aim of this study was to assess clinical and radiographic outcomes and report graft incorporation assessed on CT scan after RTSA where structural bone autograft or allograft was used to reconstruct the glenoid.

METHODS

From May 2011 through June 2016, 38 patients underwent RTSA with structural bone graft. Of these, 35 were available for a minimum 2-year follow-up and retrospectively enrolled. From July 2016 through February 2019, 32 patients undergoing RTSA with structural bone graft were prospectively enrolled. Preoperative and postoperative American Shoulder and Elbow Surgeons and visual analog scale (for pain) scores and radiographs were obtained. CT scan was obtained at least 1 year postoperatively.

RESULTS

Thirty-five patients were enrolled retrospectively (52.2%) and 32 prospectively (47.8%). Autograft was used in 46 cases (68.7%) and allograft in 21 cases. The mean American Shoulder and Elbow Surgeons score improved from 33.1 (SD 18.5) to 78.2 (SD 22.4), with P < 0.0001. On postoperative radiographs, 63 cases (94.0%) showed stable RTSA constructs while four cases (6.0%) developed glenoid baseplate subsidence. Postoperative CT scan demonstrated complete graft incorporation in 45 cases (90.0%) while partial incorporation was noted in 4 cases (8.0%), and in 1 case (2.0%), there was no graft incorporation. No correlation was observed between baseplate subsidence and graft type (autograft versus allograft) or primary versus revision surgery.

DISCUSSION

Reverse shoulder arthroplasty with structural bone autograft and allograft is reliable for glenoid augmentation in patients undergoing RTSA in both primary and revision settings. Bony incorporation of autograft and allograft as evaluated on CT scan is predictably high.

Metallic Lateralized-Offset Glenoid Reverse Shoulder Arthroplasty

Background

Metallic lateralized-offset glenoid reverse shoulder arthroplasty (RSA) for cuff tear arthropathy combines the use of a metallic augmented baseplate with a metaphyseally oriented short stem design that can be applied at a 135° or 145° neck-shaft angle, leading to additional lateralization on the humeral side. Lateralization of the center of rotation decreases the risk of inferior scapular notching and improves external rotation, deltoid wrapping, residual rotator cuff tensioning, and prosthetic stability1-4. Metallic increased-offset RSA (MIO-RSA) achieves lateralization and corrects inclination and retroversion while avoiding graft resorption and other complications of bony increased-offset RSA (BIO-RSA)5-8. Reducing the neck-shaft angle from the classical Grammont design, in combination with glenoid lateralization, improves range of motion9,10 by reducing inferior impingement during adduction at the expense of earlier superior impingement during abduction2,11. Lädermann et al.12 investigated how different combinations of humeral stem and glenosphere designs influence range of motion and muscle elongation. They assessed 30 combinations of humeral components, as compared with the native shoulder, and found that the combination that allows for restoration of >50% of the native range of motion in all directions was a 145° onlay stem with a concentric or lateralized tray in conjunction with a lateralized or inferior eccentric glenosphere. In addition, the use of a flush-lay or a slight-onlay stem design (like the one utilized in the presently described technique) may decrease the risk of secondary scapular spine fracture13,14. The goal of this prosthetic design is to achieve an excellent combination of motion and stability while reducing complications.

Description

This procedure is performed via a deltopectoral approach with the patient in the beach-chair position under general anesthesia combined with a regional interscalene nerve block. Subscapularis tenotomy and capsular release are performed, the humeral head is dislocated, and any osteophytes are removed. An intramedullary cutting guide is placed for correct humeral resection. The osteotomy of the humeral head is performed in the anatomical neck with an inclination of 135° and a retroversion of 20° to 40°, depending on the anatomical retroversion. The glenoid is prepared as usual. The lateralized, augmented baseplate is assembled with the central screw and the baseplate-wedge-screw complex is placed by inserting the screw into the central screw hole. Four peripheral screws are utilized for definitive fixation. An eccentric glenosphere with inferior overhang is implanted. The humerus is dislocated, and the metaphysis is prepared. Long compactors are utilized for proper stem alignment, and an asymmetric trial insert is positioned before the humerus is reduced. Stability and range of motion are assessed. The definitive short stem is inserted and the asymmetric polyethylene is impacted, resulting in a neck-shaft angle of 145°. Following reduction, subscapularis repair and wound closure are performed.

Alternatives

BIO-RSA is the main alternative to MIO-RSA. Boileau et al.15 demonstrated satisfactory early and long-term outcomes of BIO-RSA for shoulder osteoarthritis. A larger lateral offset may also be achieved with a thicker glenosphere2,16. Mark A. Frankle developed an implant that addressed the drawbacks of the Grammont design: a lateralized glenosphere combined with a 135° humeral neck-shaft angle. The 135° neck-shaft angle provides lateral humeral offset, preserving the normal length-tension relationship of the residual rotator cuff musculature, which optimizes its strength and function. The lateralized glenosphere displaces the humeral shaft laterally, minimizing the potential for impingement during adduction2,9,17,18. The advantage of BIO-RSA and MIO-RSA over lateralized glenospheres is that the former options provide correction of angular deformities without excessive reaming, which can lead to impingement19.

Rationale

BIO-RSA has been proven to achieve excellent functional outcomes15,20,21; however, the bone graft can undergo resorption, which may result in early baseplate loosening. Bipolar metallic lateralized RSA is an effective strategy for achieving lateralization and correction of multiplanar defects while avoiding the potential complications of BIO-RSA6,7,22-24. MIO-RSA also overcomes another limitation of BIO-RSA, namely that BIO-RSA is not applicable when the humeral head is not available for use (e.g., humeral head osteonecrosis, revision surgery, fracture sequelae).

Expected Outcomes

A recent study evaluated the clinical and radiographic outcomes of metallic humeral and glenoid lateralized implants. A total of 42 patients underwent primary RSA. Patients were documented prospectively and underwent follow-up visits at 1 and 2 years postoperatively. That study demonstrated that bipolar metallic lateralized RSA achieves excellent clinical results in terms of shoulder function, pain relief, muscle strength, and patient-reported subjective assessment, without instability or radiographic signs of scapular notching23. Kirsch et al.25 reported the results of primary RSA with an augmented baseplate in 44 patients with a minimum of 1 year of clinical and radiographic follow-up. The use of an augmented baseplate resulted in excellent short-term clinical outcomes and substantial deformity correction in patients with advanced glenoid deformity. No short-term complications and no failure or loosening of the augmented baseplate were observed. Merolla et al.7 compared the results of 44 patients who underwent BIO-RSA and 39 patients who underwent MIO-RSA, with a minimum follow-up of 2 years. Both techniques provided good clinical outcomes; however, BIO-RSA yielded union between the cancellous bone graft and the surface of the native glenoid in <70% of patients. On the other hand, complete baseplate seating was observed in 90% of MIO-RSA patients.

Important Tips

When performing subscapularis tenotomy, leave an adequate stump to allow end-to-end repair.Tenotomize the superior part of the subscapularis tendon in an L-shape, sparing the portion below the circumflex vessels.As glenoid exposure is critical, perform a 270° capsulotomy.Continuously check the orientation of the baseplate relative to the prepared hole and reamed surface to ensure accurate implantation of the full wedge baseplate to achieve a proper fit.Aim for 70% to 80% seating of the baseplate onto the prepared glenoid surface. Avoid overtightening or excessive advancement of the baseplate into the subchondral bone. Gaps between the baseplate and glenoid surface should also be avoided.In order to avoid varus or valgus malpositioning of the final implant, obtain proper diaphyseal alignment by following "the three big Ls": large, lateral, and long. Use a large metaphyseal component to fill the metaphysis. Place the guide pin for the reaming of the metaphysis slightly laterally into the resected surface of the humerus. Use long compactors for diaphyseal alignment to avoid varus or valgus malpositioning of the final implant.Use an intramedullary cutting guide for correct humeral resection.Utilize the correct liner in order to obtain proper tensioning and avoid instability.

Acronyms and Abbreviations

K wire = Kirschner wireROM = range of motion.

Short-Term Radiographic Outcomes of Bone Versus Metallic Augmented, Central Screw Type Baseplate in Reverse Total Shoulder Arthroplasty: Matched Case-Control Study

Background

Although glenoid bone grafting and metallic augmented baseplates have demonstrated success in restoring the glenohumeral joint line in the recent literature, there remain no consensus guidelines defining the use of one versus the other.

Methods

Between 2017 and 2020, 15 primary RTSA with screw-in metallically augmented glenoid baseplates were identified and 2:1 matched by age, sex, and body mass index with primary bony-augmented glenoid baseplate patients. Patients with previous glenoid implantation or fracture were excluded. Charts, routine radiographic series (Grashey, Scapula Y, Axillary lateral), and 3-dimensional computed tomography (3D CT) scans were retrospectively reviewed. Structural patient-specific metal or bony augmentation was indicated based on preoperative glenoid morphology as identified by 3D CT. Aseptic failure was identified as hardware breakage and/or shift in glenoid baseplate component position.

Results

There were 45 eligible cases with mean age of 65.7 years (range 44-85 years) and 65.5 years (range 42-82 years) for the metallic-augmented and bone graft group, respectively. Correspondingly, mean follow up was 22.6 months (range 12-53 months), and 27.3 months (range 11-53 months). At latest follow up, there were no baseplate failures in the metallic augment group and 2 baseplate failures (7%) in the bone graft group at a mean of 42.5 months (range 32-53 months) postoperatively. Mean age of the bone failure group was 64.5 years (range 64-65 years).

Conclusion

Contemporary reversed shoulder arthroplasty glenoid baseplate designs appear to have low incidence of failure. Further analysis is necessary to determine if a critical degree of glenoid retroversion or inclination is preferable with a specific form of augmentation.

Level of Evidence

III; Retrospective Cohort Comparison.

Primary and revision reverse total shoulder arthroplasty using a patient-matched glenoid implant for severe glenoid bone deficiency

BACKGROUND

Severe glenoid bone loss in the setting of both primary and revision reverse total shoulder arthroplasty (rTSA) continues to remain a significant challenge. The purpose of this study was to report on radiographic and clinical outcomes of primary and revision rTSA using a patient-matched, 3-dimensionally printed metal glenoid implant to address severe glenoid bone deficiency. This is a follow-up study to previously reported preliminary results.

METHODS

A retrospective review was performed on 62 patients with severe glenoid bone deficiency who underwent either primary or revision rTSA using the Comprehensive Vault Reconstruction System (VRS) (Zimmer Biomet) at a single institution. Preoperative and postoperative values for the Disabilities of the Arm, Shoulder and Hand (DASH), Constant, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Simple Shoulder Test (SST), Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) pain scores as well as active range of motion (ROM) were collected and compared using the Wilcoxon signed rank test with the level of statistical significance set at P < .05. The percentage of patients achieving minimal clinically important difference (MCID) and substantial clinical benefit (SCB) was also calculated.

RESULTS

Fifty-five of 62 shoulders (88.7%) were able to be contacted at a minimum of 2 years postoperatively, with 47 of 62 (75.8%) having complete clinical and radiographic follow-up with a mean age of 67.5 years (range, 48-85 years) and follow-up of 39.2 months (range, 25-56 months). There were 19 primary and 28 revision rTSAs. Significant improvements were seen in mean active forward flexion (63.1° ± 30.3° to 116.8° ± 35°), abduction (48.1° ± 16.1 to 76.2° ± 13.4°) (P < .001), external rotation (16° ± 23.7° to 32.1° ± 24.5°) (P < .005), DASH (59.9 ± 17.7 to 35.7 ± 24.3), Constant (23.4 ± 13.1 to 53.1 ± 17.4), ASES (27.8 ± 16.2 to 69.1 ± 25.2), SST (3.3 ± 2.5 to 7.6 ± 3.5), SANE (28.9 ± 18.3 to 66.7 ± 21.2), and VAS pain (7.1 ± 2.4 to 1.8 ± 2.6) scores (P < .001). MCID and SCB was achieved in a majority of patients postoperatively. The overall complication rate was 29.1%, with only 1 baseplate failure.

CONCLUSION

This study demonstrates promising evidence that the VRS implant can be used as a viable option to achieve clinically important improvement in a majority of patients treated for severe glenoid bone deficiency with rTSA in both the primary and revision setting.

Reverse total shoulder arthroplasty for primary osteoarthritis with restricted preoperative forward elevation demonstrates similar outcomes but faster range of motion recovery compared to anatomic total shoulder arthroplasty

BACKGROUND

Reverse total shoulder arthroplasty (RSA) has been increasingly utilized for a variety of shoulder pathologies that are difficult to treat with anatomical total shoulder arthroplasty (TSA). Few studies have compared the outcomes of TSA vs. RSA in patients with cuff intact glenohumeral osteoarthritis and poor preoperative forward elevation. This study aimed to determine whether there is a difference in functional outcomes and postoperative range of motion (ROM) between TSA and RSA in these patients.

METHODS

This retrospective cohort study included 116 patients who underwent RSA or TSA between 2013 and 2022 for the treatment of rotator cuff intact primary osteoarthritis with restricted preoperative forward flexion (FF) and a minimum 1-year follow-up. Each arthroplasty group was divided into 2 subgroups: patients with preoperative FF between 91° and 120° or FF lower than or equal to 90°. Patients' clinical outcomes, including active ROM, American Shoulder and Elbow Surgeons score, visual analog scale for pain, and subjective shoulder value were collected. Clinical and radiographic complications were evaluated.

RESULTS

There was no significant difference between RSA and TSA in terms of sex (58.3% male vs. 62.2% male, P = .692), or follow-up duration (20.1 months vs. 17.7 months, P = .230). However, the RSA cohort was significantly older (72.0 ± 8.2 vs. 65.4 ± 10.6, P = .012) and weaker in FF and (ER) before surgery (P < .001). There was no difference between RSA (57 patients) and TSA (59 patients) in visual analog scale pain score (1.2 ± 2.3 vs. 1.3 ± 2.3, P = .925), subjective shoulder value score (90 ± 15 vs. 90 ± 15, P = .859), or American Shoulder and Elbow Surgeons score (78.4 ± 20.5 vs. 82.1 ± 23.2, P = .476). Postoperative active ROM was statistically similar between RSA and TSA cohorts in FF (145 ± 26 vs. 146 ± 23, P = .728) and ER (39 ± 15 vs. 41 ± 15, P = .584). However, internal rotation was lower in the RSA cohort (P < .001). This was also true in each subgroup. RSA led to faster postoperative FF and ER achievement at 3 months (P < .001). There was no statistically significant difference in complication rates between cohorts.

CONCLUSION

This study demonstrates that patients with glenohumeral osteoarthritis who have a structurally intact rotator cuff but limited preoperative forward elevation can achieve predictable clinical improvement in pain, ROM, and function after either TSA or RSA. Reverse arthroplasty may be a reliable treatment option in patients at risk for developing rotator cuff failure.

Can we separately measure glenoid vs. humeral lateralization and distalization in reverse shoulder arthroplasty?

BACKGROUND

Lateralization and distalization in reverse shoulder arthroplasty (RSA) can be measured on anteroposterior (AP) radiographs using 2 previously described angles: lateralization shoulder angle (LSA) and distalization shoulder angle (DSA). However, these 2 angles measure global lateralization and distalization but do not allow to differentiate how much lateralization or distalization are attributable to the glenoid and the humerus. We hypothesized that new angles could allow us to separately measure glenoid vs. humeral lateralization and distalization. A more precise understanding of independent glenoid and humeral contributions to lateralization and distalization may be beneficial in subsequent clinical research.

METHOD

Retrospective analysis of postoperative AP radiographs of 100 patients who underwent primary RSA for cuff-tear arthropathy, massive cuff tear, or glenohumeral osteoarthritis were analyzed. The new angles that we proposed use well-known bony landmarks (the acromion, glenoid, and humerus) and the most lateral point of the glenosphere, which we termed the "glenoid pivot point" (GPP). For lateralization, we used the GPP to split LSA into 2 new angles: glenoid lateralization angle (GLA) and humeral lateralization angle (HLA). For distalization, we introduced the modified distalization shoulder angle (mDSA) that can also be split into 2 new angles: glenoid distalization angle (GDA) and humeral distalization angle (HDA). Three orthopedic surgeons measured the new angles, using the online tool Tyche. Mean values with overall and individual standard deviations as well as intraclass correlation coefficients (ICCs) were calculated.

RESULTS

Because the angles form a triangle, the following equations can be made: LSA = GLA + HLA, and mDSA = GDA + HDA. All angles showed excellent inter- and intraobserver reliability (ICC = 0.92-0.97) with low means of individual standard deviations that indicate a precision of 2° for each angle.

CONCLUSION

Use of the most lateral part of the glenosphere (termed glenoid pivot point) allows us to separately measure glenoid vs. humeral lateralization and distalization. The 4 new angles (HLA, GLA, GDA, HDA) described in the present study can be used on true AP radiographs, routinely obtained after shoulder replacement, and the measured angles may be used with all types of reverse prostheses available.

Both angled bony-increased offset and metal-augmented baseplates provide satisfactory bone incorporation to the glenoid in reverse total shoulder arthroplasty: a radiographic evaluation using tomosynthesis

BACKGROUND

Angled bony-increased offset and metal-augmented baseplate have recently been used to achieve neutral to inferior inclination of the glenoid implant. Nonetheless, bone incorporation is difficult to evaluate using computed tomography or other conventional methods owing to the presence of metal artifacts; therefore, whether bone incorporation between the grafted bone and glenoid or between the graft and baseplate implant can be achieved remains unclear. Several studies have reported the effectiveness of tomosynthesis in reducing metal artifacts for the evaluation of implant loosening, bone resorption, and spot welds. We aimed to evaluate and compare the bone incorporation rates between angled bony-increased offset and metal-augmented implants using tomosynthesis with metal artifact reduction technology. We hypothesized that a high bone incorporation rate would be obtained with angled bony-increased offset and a metal-augmented baseplate.

METHODS

A total of 52 patients who underwent reverse total shoulder arthroplasty (TSA) with angled bony-increased offset and 42 patients who underwent reverse total shoulder arthroplasty with metal-augmented baseplate were assessed and followed up for a minimum of 2 years. The bone incorporation and implant loosening rates were compared between the 2 groups, and the sites of spot welds and trabeculation were recorded according to zones. Bone incorporation between the bone and prosthesis was defined as a confirmation of spot welds connecting the porous area and bone in more than three zones. Bone incorporation between the native bone and grafted bone was defined as an observation of trabeculation. Glenoid loosening was defined as the presence of at least 1 mm radiolucency around the prosthesis in more than 2 zones.

RESULTS

Both the angled bony-increased offset and metal-augmented baseplate groups achieved sufficient bone incorporation rates (98% [51/52 cases] vs. 100% [42/42 cases], P = 1.0) and low implant loosening rates (2% [1/52 cases] vs. 0% [0/42 cases], P = 1.0). Spot welds and trabeculation were likely to be confirmed in the lower parts of the glenoid.

CONCLUSION

The two groups did not show any significant differences regarding bone incorporation rates. Considering the complexity of performing the procedure with angled bony-increased offset, the use of a metal-augmented baseplate can serve as an alternative treatment to avoid superior inclination in reverse total shoulder arthroplasty.

Lateralising reverse shoulder arthroplasty using bony increased offset (BIO-RSA) or increasing glenoid component diameter: comparison of clinical, radiographic and patient reported outcomes in a matched cohort

BACKGROUND

This study aims to compare the range of motion (ROM) of reverse shoulder arthroplasty lateralised by bony increased offset (BIO-RSA) using a standard 38-mm (mm) component to regular reverse shoulder arthroplasty (RSA) lateralised by using a 42-mm glenoid component. The secondary aims are to compare patient-reported and radiographic outcomes between the two groups.

MATERIALS AND METHODS

All patients with a BIO-RSA and size 38 glenosphere were retrospectively identified and matched to patients with a regular RSA and size 42 glenosphere. Matched patients were invited for a follow-up visit. ROM was assessed as well as radiographic outcomes (lateralisation, distalisation, inferior overhang, scapular notching, heterotopic bone formation, radiolucency, stress shielding, bone graft healing and viability and complications) and patient-reported outcomes (subjective shoulder value, Constant score, American Shoulder and Elbow Surgeons, activities of daily living which require internal rotation, activities of daily living which require external rotation and a visual analogue scale for pain). Outcomes were compared between the two groups.

RESULTS

In total, 38 BIO-RSAs with a size 38 glenosphere were matched to 38 regular RSAs with a size 42 glenosphere. Of the 76 matched patients, 74 could be contacted and 70 (95%) were included. At the final follow-up, there were no differences between the two groups in ROM, patient-reported outcomes or radiographic outcomes (p > 0.485).

CONCLUSIONS

Using a larger glenosphere is a feasible alternative to BIO-RSA for lateralising RSA, providing comparable ROM, patient-reported and radiographic results, while potentially decreasing costs, operative time and complication rates.

LEVEL OF EVIDENCE III

Reverse shoulder arthroplasty design-inlay vs. onlay: does it really make a difference?

BACKGROUND

The design of reverse shoulder arthroplasty (RSA) implants has evolved significantly over the past 50 years. Today there are many options available that differ in design of the glenoid and humeral components, fixation methods, sizes, and modularity. With respect to the humeral component, the literature has generally focused on the differences between inlay and onlay designs and the potential impact on outcomes. However, inlay and onlay design represents only one factor of many.

METHODS

It is our hypothesis that separating onlay and inlay designs into 2 distinct entities is an oversimplification as there can be a wide overlap of the 2 designs, depending on surgical technique and the implant selected. As such, the differences between inlay and onlay designs should be measured in absolute terms-meaning combined distalization and lateralization.

RESULTS

By reviewing the many factors that can contribute to the glenosphere-humerus relationship, the role of inlay and onlay humeral designs as an important distinguishing feature is shown to be limited. Preliminary studies suggest that the amount of distalization and lateralization of the construct may be the most accurate method of describing the differences in the constructs.

CONCLUSIONS

Inlay and onlay humeral component design represents only one factor of many that may impact outcomes. A more accurate method of defining specific design and technique factors in RSA is the degree of lateralization and distalization.

The effect of eccentric glenoid reaming in reverse shoulder artrhoplasty for glenohumeral osteoarthritis

Background

The objective of this study was to evaluate the abilitiy of eccentric reaming in reverse total shoulder arthroplasty (RSA), in patients with glenohumeral osteoarthritis (GHOA), to correct preoperative glenoid retroversion and to compare with cuff tear arthopaty (CTA) cases.

Methods

Fifty-nine patients who underwent RSA with GHOA or CTA diagnosis between 2013 and 2022 and who had pre- and postoperative computed tomography scans were included in the study. Preoperative glenoid version and postoperative glenoid component versions of 17 patients with GHOA and 40 patients with CTA were measured by Friedman method.

Results

The median preoperative glenoid versions in GHOA and CTA groups were measured as 16° and 4° retroverted respectively (p < 0.01). The median postoperative glenoid component versions in GHOA and CTA groups were 5° and 3° retroverted respectively (p = 0.09). The version change differences between the two groups varied significantly (p < 0.01).

Conclusions

GHOA is related with higher preoperative glenoid retroversion compared to CTA. However; with eccentric glenoid reaming, adequate version correction and similar postoperative glenoid version can be achieved in GHOA compared to CTA when performing a RSA.

Level of evidence

Level III. Retrospective study. Treatment study.

The Value of Computed Tomography-Based Planning in Shoulder Arthroplasty Compared to Intra-/Interobserver Reliability of X-ray Planning

Background: Reversed total shoulder arthroplasty (RTSA) is an established surgery for many pathologies of the shoulder and the demand continues to rise with an aging population. Preoperative planning is mandatory to support the surgeon's understanding of the patient's individual anatomy and, therefore, is crucial for the patient's outcome. Methods: In this observational study, we identified 30 patients who underwent RTSA with two- and three-dimensional preoperative planning. Each patient underwent new two-dimensional planning from a medical student and an orthopedic resident as well as through a mid-volume and high-volume shoulder surgeon, which was repeated after a minimum of 4 weeks. The intra- and interobserver reliability was then analyzed and compared to the 3D planning and the implanted prosthesis. The evaluated parameters were the size of the pegged glenoid baseplate, glenosphere, and humeral short stem. Results: The inter-rater reliability showed higher deviations in all four raters compared to the 3D planning of the base plate, glenosphere, and shaft. The intra-rater reliability showed a better correlation in more experienced raters, especially in the planning of the shaft. Conclusions: Our study shows that 3D planning is more accurate than traditional planning on plain X-rays, despite experienced shoulder surgeons showing better results in 2D planning than inexperienced ones.

Femoral head allograft for glenoid bone loss in primary reverse shoulder arthroplasty: functional and radiologic outcomes

BACKGROUND

Several techniques have been adopted during primary reverse shoulder arthroplasty (RSA) to manage glenoid bone defect. Among bone grafts, humeral head autograft is currently the mainstream option. However, autologous humeral heads may be unavailable or inadequate, and allografts may be a viable alternative. The aim of the present study was to evaluate the functional and radiologic outcomes of femoral head allografts for glenoid bone defects in primary RSA.

METHODS

We conducted a retrospective study with prospective data collection enrolling 20 consecutive patients who underwent RSA with femoral head allografts for glenoid bone defects. Indications for surgery were eccentric cuff tear arthropathy in 10 cases (50%), concentric osteoarthritis in 9 cases (45%), and fracture sequelae in 1 case (5%). Each patient was evaluated preoperatively and at follow-up by radiologic and computed tomography (CT) and by assessing the range of motion (ROM) and the Constant-Murley score (CMS). A CT-based software, a patient-specific 3D model of the scapula, and patient-specific instrumentation were used to shape the graft and to assess the position of K-wire for the central peg. Postoperatively, CT scans were used to identify graft incorporation and resorption.

RESULTS

After a median follow-up of 26.5 months (24-38), ROM and CMS showed a statistically significant improvement (all P = .001). The median measures of the graft were as follows: 28 mm (28-29) for diameter, 22° (10°-31°) for angle, 4 mm (2-8 mm) for minimum thickness, and 15 mm (11-21 mm) for maximum thickness. Before the surgery, the median glenoid version was 21.8° (16.5°-33.5°) for the retroverted glenoids and -13.5° (-23° to -12°) for the anteverted glenoids. At the follow-up, the median postoperative baseplate retroversion was 5.7° (2.2°-1.5°) (P = .001), and this value was close to the 4° retroversion planned on the preoperative CT-based software. Postoperative major complications were noted in 4 patients: 2 dislocations, 1 baseplate failure following a high-energy trauma, and 1 septic baseplate failure. Partial graft resorption without glenoid component failure was observed in 3 cases that did not require revision surgery.

CONCLUSION

The femoral head allograft for glenoid bone loss in primary RSA restores shoulder function, with CMS values comparable to those of sex- and age-matched healthy individuals. A high rate of incorporation of the graft and satisfactory correction of the glenoid version can be expected after surgery. The management of glenoid bone defects remains a challenging procedure, and a 15% risk of major complication must be considered.

Comparison of short-term clinical outcomes and radiographic changes in Grammont reverse shoulder arthroplasty between the French and Japanese populations: A propensity score-matched analysis

BACKGROUND

Although Grammont-style reverse total shoulder arthroplasty (RSA) showed excellent clinical results in Europe, its utility for Asian populations remains unclear. This study aimed to compare the French and Japanese populations in terms of range of motion (ROM), functional outcomes, and scapular notching rates in patients who underwent standard Grammont-style RSA. We hypothesized that RSA for the Japanese population may not provide as good ROM and functional results at the final follow-up as that for the French population.

METHODS

A total of 25 Japanese patients undergoing RSA were propensity score matched to 25 French patients undergoing RSA. The patients were matched for four different covariates using a propensity score analysis. The minimum follow-up period was 2 years. We investigated differences between the populations with respect to body size and shoulder joint ROM and Constant score (CS) measured preoperatively and at the final follow-up. Scapular notching was examined using radiographs at the final follow-up.

RESULTS

The average height and weight of the French and Japanese patients were 164 cm and 70 kg and 152 cm and 56 kg, respectively. Anterior elevation (AE), external rotation (ER) at the side, internal rotation (IR), and CS total changed from 101° to 145°, 17° to 15°, 4.5 points to 5.5 points, and 36 points to 72 points, respectively, in the French population and from 63° to 119°, 8.5° to 13°, 4.6 points to 4 points, and 28 points to 58 points, respectively, in the Japanese population. AE improved in both the groups; ER and IR remained unchanged before and after surgery. The frequency of scapular notching (>grade 1) was higher in the Japanese population (56%) than in the French population (20%) (p = 0.019).

CONCLUSIONS

Grammont-style RSA improved AE and CS in both the populations, but AE and CS were significantly higher in the French population than in the Japanese population at the final follow-up. Scapular notching frequently occurs in the Japanese population.

Mid-term results of the use of structural humeral head autograft to correct glenoid bone loss in reverse total shoulder arthroplasty

Background

Native glenoid bone loss presents technical challenges in shoulder arthroplasty. The purpose of this study is to report the mid-term clinical and radiographic outcomes of patients treated with structural humeral head autograft reconstruction of glenoid bone loss in the setting of reverse total shoulder arthroplasty (rTSA).

Methods

Retrospective review of 30 shoulders in 28 patients undergoing rTSA with a structural humeral head autograft to correct glenoid bone loss. Demographics, comorbidities, anatomic details, and patient-reported outcome measures were collected for analysis.

Results

Range of motion and patient-reported outcome measures were all significantly improved postoperatively (P < .001). Bone grafts were found to incorporate into 100% of shoulders, with no protheses displaying signs of loosening or other structural concerns. No revision procedures were performed, and all patients were satisfied with their shoulder postoperatively. Two patients developed scapular notching on follow-up.

Discussion

The use of a humeral head autograft to reconstruct glenoid bone loss in patients undergoing rTSA is a safe and effective procedure. It allows for a local graft source to be utilized thus avoiding potential comorbidity and complications associated with the use of alternative site autografts or allografts and has the advantage of nearly congruent fit within the defect.

The Use of an External Cutting Guide for Patient-Specific Bone Grafting in Reverse Total Shoulder Arthroplasty: A Novel Technique

Glenoid bone loss remains a substantial challenge in reverse shoulder arthroplasty and failure to address such bone loss may lead to implant malpositioning, instability and/or premature baseplate loosening. Currently, management of glenoid bone loss can be achieved by metal augmentation or bone grafting (ie, autograft or allograft). At the present time, options for creating and shaping glenoid bone grafts include free-hand techniques and simple reusable cutting guides that create the graft at a standard shape/angle. To our knowledge, there is no external guide available that enables surgeons to accurately prepare the bone graft to the desired dimensions/shape (ie, trapezoid or biplanar) to correct the glenoid deformity. In this article, we present a novel surgical technique that utilizes an external guide for creating a patient-specific bone graft to address glenoid deformity in the setting of reverse total shoulder arthroplasty.

Three-dimensional finite element modeling of glenoid bone loss and baseplate fixation in reverse total shoulder arthroplasty

Background

Posterior glenoid bone loss is frequently observed in patients with osteoarthritis undergoing reverse total shoulder arthroplasty. Glenoid bone loss can reduce the baseplate back support area and the number of screws for fixation. The purpose of this study is to determine how initial baseplate fixation is affected by biomechanical factors introduced by glenoid bone loss such as reduced baseplate back support area and reduced screw number using three-dimensional finite element analysis.

Methods

Computerized tomography images of a healthy shoulder were selected and segmented to obtain the solid geometry. Solid models were generated with 100%, 75%, 67%, 50%, and 25% glenoid baseplate back support. With these geometries, two groups of finite element models were then built. In the bone loss areas, screws were maintained in one group of models but were removed in the other group of models. 750N compressive loading was applied along the direction parallel to the scapula axis. Maximum von Mises stress and maximum micromotion between the bone and implant were recorded and evaluated for each glenoid bone model.

Results

In the group of models where all screws remained in place, the maximum stress and maximum micromotion between the bone and implant exhibited minimal variation. The maximum stresses were 21.10MPa and the maximum micromotions were between 2-3 μm. However, in the group of models removing screws in the bone loss areas, maximum stress increased from 20MPa to 45MPa and maximum micromotion increased from 2 μm to 85 μm as the backside support area decreased from 100% to 25%.

Discussion

In conclusion, this three-dimensional finite element analysis study demonstrates that initial fixation can be achieved with approximately 1/3 posterior glenoid bone deficiency even without screw placement in the area of bone loss. Glenoid bone loss affects baseplate fixation mainly by reducing the screw numbers for fixation. If screws can be placed in the bone loss area, the decreased baseplate back support area will not result in increased stresses or micromotion leading to baseplate failure. This study suggests that surgeons should consider applying screws to the bone loss area if the remaining bone is able to hold the screw.

Level of evidence

Computer Modeling Study.

Angled BIO-RSA leads to better inclination and clinical outcomes compared to Standard BIO-RSA and eccentric reaming: A comparative study

Background

Two surgical techniques were compared : Standard BIO-RSA, performed with a glenoid eccentric reaming along with a cylindric bone graft augmentation vs. the Angled BIO-RSA, performed with a glenoid concentric reaming and a defect correction with an angled bone graft.

Methods

Patients undergoing RSA from January 2016 to April 2019, with one of the two techniques being performed, were retrospectively reviewed. Glenoids were classified according to Favard. Clinical (Constant-Murley, VAS and ROM) and radiographic (superior tilt correction) data were collected pre-operatively and at 12 months post-operatively.

Results

141 shoulders were included. Angled BIO-RSA group showed statistically significant better outcomes in terms of forward flexion (149.9° Vs 139.3°) and abduction (136.4° Vs 126.7°). The use of an Angled BIO-RSA showed a statistically significant better superior tilt correction (1.252° Vs 4.09°). Angled BIO-RSA, leads to a better inclination correction and a mean postoperative tilt value inferior to 5° in E1 and E3 differently from standard BIO-RSA.

Discussion

Both techniques were able to correct glenoid superior inclination with excellent postoperative short-term results. However, angled BIO-RSA technique appears to be more effective in ensuring a correct inclination of the prosthetic glenoid component with better clinical outcomes.

BIO-RSA vs. metal-augmented baseplate in shoulder osteoarthritis with multiplanar glenoid deformity: a comparative study of radiographic findings and patient outcomes

BACKGROUND

Reverse shoulder arthroplasty (RSA) requiring extensive reaming to address severe glenoid bone loss increases the risk of glenoid medialization and baseplate failure. We hypothesized that (1) metal-augmented baseplate prevents the medialization of the joint line and preserves glenoid bone stock similarly to bony increased-offset (BIO)-RSA and (2) bone graft viability and healing in BIO-RSA patients become compromised over time.

MATERIALS AND METHODS

Eighty-one patients (83 shoulders) underwent glenoid lateralization with bone (BIO-RSA group, 44) or metal-augmented baseplate (metallic increased-offset [MIO]-RSA group, 39) and a minimum follow-up of 24 months were included. The orientation and direction of glenoid erosion was identified and recorded using computerized 3D planning. Active range of motion, and the Western Ontario Osteoarthritis of the Shoulder (WOOS) index were assessed before arthroplasty and at the last follow-up visits. Radiographic changes around the glenoid and humeral components were assessed. Healing and thickness of bone graft were evaluated by predefined criteria. Postoperative global glenoid inclination (β angle) and retroversion were also measured.

RESULTS

Delta scores of active anterior elevation were higher in the MIO-RSA group (P = .027). The differences in the other planes of shoulder motion and in WOOS index scores between the groups were not significant. Preoperative glenoid retroversion was higher in BIO-RSA patients, and glenoid inclination was similar in both groups. Type B2 and B3 glenoids had a posterior-central (91%) and posterior-superior (90%) erosion with a mean posterior humeral head subluxation of 76% and 78%, respectively. The direction of erosion in type E2 and E3 glenoids was posterior-superior, with a mean posterior humeral head subluxation of 74%. The rate of high position of the glenosphere was higher in the BIO-RSA group (P = .022), whereas the values of β angle and postoperative retroversion were similar in the 2 groups. BIO-RSA group showed radiolucent lines <2 mm around the bone graft in 16 patients (36.4%) and decreased thickness in 15 (34.1%). Incomplete baseplate seating was found in 4 MIO-RSA patients (10%). We found higher rates of humerus condensation lines in MIO-RSA patients (P = .01) and higher rates of cortical thinning and tuberosity resorption in the BIO-RSA group (P = .027 and P = .004, respectively).

CONCLUSION

Metal-augmented glenoid is a suitable alternative to BIO-RSA to preserve bone and prevent the medialization of the joint line in arthritic glenoid with multiplanar glenoid deformity. Bone and metal augmentation provided satisfactory clinical outcomes. Bone graft resorption in BIO-RSA patients raise concern about the risk of baseplate loosening and requires further long-term studies.

Relationship between the prosthesis scapular neck angle and clinical outcomes in reverse shoulder arthroplasty

Background

Optimal glenosphere positioning in reverse shoulder arthroplasty (RSA) remains highly debated. We aimed to characterize the association between the prosthesis scapular neck angle (PSNA) and postoperative range of motion (ROM) and clinical outcome scores.

Methods

A retrospective review of 284 RSAs using a single design with minimum 2-year follow-up was performed. Glenosphere tilt was measured postoperatively using PSNA. ROM and functional outcome scores were assessed preoperatively and at latest follow-up. The PSNA was dichotomized to inferior or superior groups (>90° vs ≤ 90°, respectively) and stratified into quartiles; ROM and outcome score measures were compared between groups controlling for inferior glenosphere overhang.

Results

No range of PSNA was consistently associated with superior ROM, clinical outcome scores, or rates of complications including scapular notching. However, greater preoperative to postoperative improvement in active FE was found for superiorly (PSNA ≤ 90°) versus inferiorly tilted glenospheres (37° ± 33° vs 53° ± 35°, P  =  0.005) and the greater improvement in active FE (57° ± 35°, P  =  0.004) was further isolated to the first quartile (mean 85.1° ± 3.5°).

Discussion

A lack of variation in clinical outcomes based on PSNA suggests negligible short-term (median follow-up 3.1 years) clinical significance when glenosphere tilt falls within the distribution of this cohort (mean 92.6° ± 6.2°).

Reverse shoulder arthroplasty: State-of-the-art

The reverse shoulder arthroplasty conceived by Paul Grammont in 1985 has gradually gained popularity as a treatment for multiple shoulder diseases. Unlike previous reverse shoulder prosthesis characterized by unsatisfactory results and a high glenoid implant failure rate, the Grammont design has immediately shown good clinical outcomes. This semi constrained prosthesis solved the issues of the very first designs by medializing and distalizing the center of rotation with an increased stability of the replacement of the component. The indication was initially limited to cuff tear arthropathy (CTA). It has then been expanded to irreparable massive cuff tears and displaced humeral head fractures. The most frequent problems of this design are a limited postoperative external rotation and scapular notching. Different modifications to the original Grammont design have been proposed with the aim of decreasing the risk of failure and complications and improving the clinical outcomes. Both the position and version/inclination of the glenosphere and the humeral configuration (e.g. neck shaft angle) influence the RSA outcomes. A lateralized glenoid (whether with bone or metal) and a 135° Inlay system configuration leads to a moment arm which is the closest to the native shoulder. Clinical research will focus on implant designs reducing bone adaptations and revision rate, strategies to prevent more effectively infections. Furthermore, there is still room for improvement in terms of better postoperative internal and external rotations and clinical outcomes after RSA implanted for humeral fracture and revision shoulder arthroplasty.

Clinical and radiologic outcomes of Lima ProMade custom 3D-printed glenoid components in primary and revision reverse total shoulder arthroplasty with severe glenoid bone loss: a minimum 2-year follow-up

BACKGROUND

The purpose of this study is to report the clinical and radiologic outcomes of patients undergoing primary or revision reverse total shoulder arthroplasty using custom 3D-printed components to manage severe glenoid bone loss with a minimum of 2-year follow-up.

METHODS

Following ethical approval, patients were identified and invited to participate. Inclusion criteria were (1) severe glenoid bone loss necessitating the need for custom implants and (2) patients with definitive glenoid and humeral components implanted more than 2 years prior. Included patients underwent clinical assessment using the Oxford Shoulder Score (OSS), Constant-Murley score, American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), and the quick Disabilities of the Arm, Shoulder, and Hand questionnaire (QuickDASH). Radiographic assessment included anteroposterior and axial projections. Patients were invited to attend a computed tomography (CT) scan to confirm osseointegration. Statistical analysis used descriptive statistics (mean and standard deviation [SD]) and paired t test for parametric data.

RESULTS

Eleven patients declined to participate. Five patients were deceased prior to study commencement, leaving 42 remaining patients in this analysis. Three patients had revision surgery before the 2-year follow-up; of these, 2 retained their custom glenoid components. Mean follow-up was 31.6 months from surgery (range 24-52 months). All 4 scores improved: OSS from a mean 15 (SD 8.4) to 36 (SD 12) (P < .001), Constant-Murley score from a mean 15 (SD 11.2) to 52 (SD 20.1) (P < .001), QuickDASH from a mean 70 (SD 21) to 31 (SD 24.8) (P = .004), and the ASES score from a mean 22 (SD 17.8) to 71 (SD 23.3) (P = .007). Radiologic evaluation demonstrated good osseointegration in all but 1 included patient.

CONCLUSION

The utility of custom 3D-printed components for managing severe glenoid bone loss in primary and revision reverse total shoulder arthroplasty yields significant clinical improvements in this complex cohort. Large complex glenoid bone defects can be managed successfully with custom 3D-printed glenoid components.

Treatment of Glenoid Wear with the Use of Augmented Glenoid Components in Total Shoulder Arthroplasty: A Scoping Review

» Treatment of glenoid bone loss continues to be a challenge in total shoulder arthroplasty (TSA). Although correcting glenoid wear to patient's native anatomy is desirable in TSA, there is lack of consensus regarding how much glenoid wear correction is acceptable and necessary in both anatomic and reverse TSA.» Use of augmented glenoid components is a relatively new treatment strategy for addressing moderate-to-severe glenoid wear in TSA. Augmented glenoid components allow for predictable and easy correction of glenoid wear in the coronal and/or axial planes while at the same time maximizing implant seating, improving rotator cuff biomechanics, and preserving glenoid bone stock because of off-axis glenoid reaming.» Augmented glenoid components have distinct advantages over glenoid bone grafting. Glenoid bone grafting is technically demanding, adds to the surgical time, and carries a risk of nonunion and graft resorption with subsequent failure of the glenoid component.» The use of augmented glenoid components in TSA is steadily increasing with easy availability of computed tomography-based preoperative planning software and guidance technology (patient-specific instrumentation and computer navigation).» Although different augment designs (full wedge, half wedge, and step cut) are available and a particular design may provide advantages in specific glenoid wear patterns to minimize bone removal (i.e. a half wedge in B2 glenoids), there is no evidence to demonstrate the superiority of 1 design over others.

Navigation in reverse shoulder arthroplasty: how the lateralization of glenosphere can affect the clinical outcome

INTRODUCTION

One of the main causes of RSA failure is attributable to the malpositioning of the glenoid component. Initial experiences with computer-assisted surgery have shown promising results in increasing the accuracy and repeatability of placement of the glenoid component and screws. The aim of this study was to evaluate the functional clinical results, in terms of joint mobility and pain, by correlating them with intraoperative data regarding the positioning of the glenoid component. The hypothesis was that the lateralization more than 25 mm of the glenosphere can led to better stability of the prosthesis but should pay in term of a reduced range of movement and increased pain.

MATERIALS AND METHODS

50 patients were enrolled between October 2018 and May 2022; they underwent RSA implantation assisted by GPS navigation system. Active ROM, ASES score and VAS pain scale were recorded before surgery. Preoperative data about glenoid inclination and version were collected by pre-op X-Rays an CT. Intraoperative data-inclination, version, medialization and lateralization of the glenoid component-were recorded using computer-assisted surgery. 46 patients had been further clinically and radiographically re-evaluated at 3-months, 6-months, 1-year, and 2-years follow-up.

RESULTS

We found a statistically significant correlation between anteposition and glenosphere lateralization value (DM - 6.057 mm; p = 0.043). Furthermore a statistically significant correlation has been shown between abduction movement and the lateralization value (DM - 7.723 mm; p = 0.015). No other statistically significant associations were found when comparing the values of glenoid inclination and version with the range of motion achieved by the patients after reverse shoulder arthroplasty.

CONCLUSION

We observed that the patients with the best anteposition and abduction results had a glenosphere lateralization between 18 and 22 mm. When increasing the lateralization above 22 mm or reducing it below 18 mm, on the other hand, both movements considered decreased their range.

LEVEL OF EVIDENCE

Level IV; Case Series; Treatment Study.

A prospective radiostereometric analysis of the stability of a metal-backed glenoid component/autograft composite in reverse shoulder arthroplasty

Aims

Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA).

Methods

A total of 14 patients who underwent a rTSA with an autograft consented to participate. Of these, 11 had a primary rTSA using humeral head autograft and three had a revision rTSA with autograft harvested from the iliac crest. The mean age of the patients was 66 years (39 to 81). Tantalum beads were implanted in the scapula around the glenoid. RSA imaging (stereographic radiographs) was undertaken immediately postoperatively and at three, six, 12, and 24 months. Analysis was completed using model-based RSA software. Outcomes were collected preoperatively and at two years postoperatively, including the Oxford Shoulder Score, the American Shoulder and Elbow Score, and a visual analogue score for pain. A Constant score was also obtained for the assessment of strength and range of motion.

Results

RSA analysis showed a small increase in all translation and rotational values up to six months postoperatively, consistent with settling of the implant. The mean values plateaued by 12 months, with no evidence of further migration. In four patients, there was significant variation outside the mean, which corresponded to postoperative complications. There was a significant improvement in the clinical and patient-reported outcomes from the preoperative values to those at two years postoperatively (p < 0.001).

Conclusion

These findings show, using RSA, that a glenoid baseplate composite of a trabecular titanium peg with autograft stabilizes within the glenoid about 12 months after surgery, and reinforce findings from a previous study of this implant/graft with CT scans at two years postoperatively, indicating that this type of structural composite results in sound early fixation.

Management of glenoid bone loss with impaction and structural bone grafting in reverse shoulder arthroplasty

INTRODUCTION

Glenoid bone loss is a commonly encountered problem in complex primary and revision shoulder arthroplasty. Addressing glenoid bone loss is critical to avoid complications like early loosening, impingement, notching and instability. A large number of techniques like bone grafting using autograft or allograft, eccentric reaming, augmented base plates, patient-specific instrumentations and custom-made implants are available to tackle bone loss.

MATERIALS AND METHODS

We prospectively collected the data of all patients with glenoid defects undergoing primary or revision reverse shoulder replacement between 2004 and 2017. This included demographic data, ranges of motion, Constant-Murley score and Subjective Shoulder Value (SSV). A pre-operative CT scan was done as well to plan the surgery and calculate the glenoid version. At each follow-up, the clinical function and shoulder scores were assessed. Additionally, the radiographs were assessed for graft incorporation, evidence of lysis and calculation of glenoid version.

RESULTS

Between 2004 and 2017, 37 patients underwent glenoid bone grafting during reverse shoulder arthroplasty. Average age was 72 years (range 46-88). Indications for surgery were cuff tear arthropathy (6 patients); revision of failed other prosthesis (23); primary osteoarthritis (4); rheumatoid arthritis (3); and second-stage revision for infection (1). The glenoid defect was contained in 24 patients, and therefore, impaction graft with a combination of bone graft substitute and/or humeral head autograft was performed. In 13 patients the glenoid defect was severe and uncontainable and therefore a graft-implant composite glenoid was implanted using humeral head autograft or allograft. Average follow-up was 3.6 years (range 1-10). Mean Constant score improved from 34 before surgery to 63 after surgery. Mean SSV score improved from 0.9/10 to 8.3/10. Active movements improved significantly with forward elevation increasing from 54° to 123°; abduction from 48° to 123°; external rotation from 24° to 38°; internal rotation from 57° to 70°. Radiographs at final follow-up showed no radiolucencies around the glenoid component and no evidence of loosening of the implant. In 2 cases there was a grade I notching. There was 100% survivorship at the last follow-up.

CONCLUSION

Impaction bone grafting along with structural grafting when required is an effective and reproducible way of managing severe glenoid bone loss. This technique gives consistent and good clinical and radiological results.

Mid-term comparative study between the glenoid and humerus lateralization designs for reverse total shoulder arthroplasty: which lateralization design is better?

INTRODUCTION

The complications of the conventional medialized design for reverse total shoulder arthroplasty (RSA) are increased scapular notching, and decreased external rotation and deltoid wrapping. Currently, lateralization design RSA, which avoid scapular notching and improve impingement-free range of motion, is commonly used. Especially, humeral lateralization design was most commonly used and glenoid lateralization design was preferred for glenoid abnormities. We compared mid-term clinical and radiologic outcomes of glenoid and humeral lateralization RSA in an Asian population in this study.

MATERIALS AND METHODS

We enrolled 124 shoulders of 122 consecutive patients (mean age 73.8 ± 6.8 years) who received glenoid or humeral lateralization RSA from May, 2012 to March, 2019. We divided these patients into two groups according to RSA using either glenoid or humeral lateralization design. These different designs were introduced consecutively in Korea. The clinical and radiological results of 60 glenoid lateralization RSA (Group I, 60 patients) and 64 humeral lateralization RSA (Group II, 62 patients) were retrospectively evaluated and also were compared between the two groups. All patients were followed for mean 3 years.

RESULTS

The clinical and radiologic outcomes of the two groups did not differ significantly, including scapular notching (p = 0.134). However, humeral lateralization RSA showed a larger glenoid-tuberosity (GT) distance (p = 0.000) and less distalization shoulder angle (DSA) (p = 0.035). The complication rate did not differ significantly either. But, revision surgery was performed for 2 humeral loosening in the Group II.

CONCLUSION

The clinical and radiologic outcomes of the two groups did not differ significantly, including scapular notching at mid-term follow-up. However, humeral lateralization design showed larger GT distance and less DSA. Humeral lateralization design RSA could preserve the normal shoulder contour due to a larger GT distance (more lateralization) and provide less deltoid tension due to less DSA (less distalization of COR).

Comparison of glenoid bone grafting vs. augmented glenoid baseplates in reverse shoulder arthroplasty: a systematic review

BACKGROUND

Management of bone loss and glenoid deformity can present a significant challenge to surgeons. The purpose of this review was to compare outcomes of reverse shoulder arthroplasty (RSA) using either bone graft or augmented baseplates for the management of glenoid bone loss and deformity.

METHODS

A comprehensive search of MEDLINE, Embase, and Cochrane indices was performed for studies reporting clinical outcomes following primary RSA with bone grafting or use of augmented baseplates. Pooled and frequency-weighted means, standard deviations, and ranges were calculated and reported for comparison.

RESULTS

Overall, 19 studies and 652 patients with bone grafting (n = 401) and augmented baseplates (n = 251) were included in the study. Mean patient age and gender were 70.3 ± 3.1 years and 47% female in the bone grafting group and 72.9 ± 3.7 years and 59.0% female in the augmented baseplate group. Mean follow-up for the augmented baseplate group was 23.1 ± 8.2 months and 29.5 ± 10.1 months for the bone grafting group. Overall complication and revision rates were 11.7% and 4.5% for the bone grafting group and 11.8% and 3.7% for the augmented baseplate group. Range of motion as well as patient-reported and functional outcome scores were similar between both techniques. Infections, component loosening, and notching were 1.9%, 3.6%, and 24.6% in the bone grafting group and 0.7%, 1.6%, and 4.7% in the augmented baseplate group.

CONCLUSIONS

Glenoid bone grafting and augmented baseplates are effective treatment options for the management of bone loss and glenoid deformity. Both treatments improve overall clinical outcomes with relatively low complication rates and revision rates.

Active physical therapy does not improve outcomes after reverse total shoulder arthroplasty: a multi-center, randomized clinical trial

OBJECTIVE

To compare range of motion (ROM) and patient-reported outcomes (PROs) between a structured home exercise program (HEP) and active, supervised physiotherapy (PT) after primary Reverse total shoulder arthroplasty (RTSA) by performing a multicenter randomized clinical trial.

METHODS

Patients undergoing primary RTSA at 2 centers were randomized to either a HEP group, in which they were given a handout and a rope pulley, or a PT group, in which they were given a standardized prescription. Surgical technique and implants were standardized. At baseline, 6 weeks, 3 months, and 1 year postoperatively, we obtained American Shoulder and Elbow Surgeons scores, Western Ontario Osteoarthritis Scores, visual analogue scale for pain scores, and measured ROM via videotape. On video, ROM was then measured by blinded observers. At all study visits, patients were asked how many days per week they were in PT and how many days a week they completed HEP to determine compliance and crossover. An a priori power analysis suggested 29 patients per group, 56 patients total to detect a difference of 30° in active forward elevation with a power of 0.8 at a 2-sided alpha of 0.05.

RESULTS

89 patients were randomized, 43 to PT, and 46 to HEP. We obtained 1-year PRO follow-up on 83 patients (93%) and ROM follow-up on 73 patients (82%). Nine patients (20%) crossed over from HEP to PT and 2 patients (4%) crossed over from PT to HEP. Complications occurred in 13% of HEP and 17% of PT patients (P = .629). Using mixed models that account for baseline values, there were no significant differences between groups in PROs or ROM at final follow-up.

CONCLUSION

In this 2-center, randomized clinical trial, there were no significant differences in patient outcomes or ROM between HEP and PT after RTSA. These findings suggest that it may not be necessary to recommend PT as a protocol for all patients after RTSA.

Challenges for Optimization of Reverse Shoulder Arthroplasty Part II: Subacromial Space, Scapular Posture, Moment Arms and Muscle Tensioning

In part II of this comprehensive review on the optimization of reverse shoulder arthroplasty (RSA), we focus on three other challenges: 1. "Conservation of sufficient subacromial and coracohumeral space"; 2. "Scapular posture"; and 3. "Moment arms and muscle tensioning". This paper follows a detailed review of the basic science and clinical literature of the challenges in part I: 1. "External rotation and extension" and 2. "Internal rotation". "Conservation of sufficient subacromial and coracohumeral space" and "Scapular posture" may have a significant impact on the passive and active function of RSA. Understanding the implications of "Moment arms and muscle tensioning" is essential to optimize active force generation and RSA performance. An awareness and understanding of the challenges of the optimization of RSA help surgeons prevent complications and improve RSA function and raise further research questions for ongoing study.

A review of custom implants for glenoid bone deficiency in reverse shoulder arthroplasty

Reverse Total Shoulder Arthroplasty is being increasingly performed, with indications in both elective and trauma settings. Accordingly, there are an increasing number of revision cases where glenoid bone loss is a concern. There are well recognised surgical techniques for dealing with mild to moderate glenoid wear, including eccentric reaming and impaction grafting. In cases of severe wear or uncontained glenoid defects these may not be suitable, and the surgeon may look to a customised implant to deal with such bone loss. There are several implant manufacturers who currently market and produce patient specific instrumentation and customised glenoid baseplates to achieve the best possible fixation in cases of severe bone loss. This article outlines some examples of custom implants currently available to surgeons, and the process by which they may be procured and used. Implant and surgical considerations, and key aspects of surgical technique are also covered. Literature on outcomes and complications following custom shoulder arthroplasty shows promising results, but at present is limited to relatively small case series with no long-term outcome data.

Accuracy of reverse shoulder arthroplasty angle according to the size of the baseplate

BACKGROUND

Glenoid inclination must be assessed precisely during preoperative planning for reverse shoulder arthroplasty (RSA) to position the glenoid baseplate correctly. We hypothesized that a more dynamic measurement method would better match the diversity of glenoid heights in the population and the variety of commercialized glenoid baseplates. Our purpose was to describe a new method to measure the RSA angle accounting for the baseplate size.

METHODS

Computed tomography scans of 50 shoulders that underwent RSA for primary osteoarthritis or cuff tear arthropathy between June 2019 and February 2020 were included (mean age, 76 years). Three variants of the RSA angle were measured: the RSA angle as originally described by Boileau et al, the relative RSA 25 angle (which simulates the implantation of a 25-mm baseplate), and the relative RSA 29 angle (which simulates the implantation of a 29-mm baseplate). Measurements in the 2-dimensional true reformatted scapular plane were made by 3 independent operators.

RESULTS

The mean R-S distance (ie, distance between point R [intersection of supraspinatus fossa line with glenoid surface] and point S [inferior border of glenoid]) was 24.2 ± 4.0 mm. The mean RSA angle was 20.3° ± 8.4°, whereas the mean relative RSA 25 angle was 19.3° ± 7.8° and the mean relative RSA 29 angle was 15.6° ± 7.6°. The mean difference between the RSA angle and the relative RSA 25 angle was 1.0° ± 4.1° (P = .16). The mean difference between the RSA angle and the relative RSA 29 angle was 4.7° ± 3.8° (P < .0001). In half of the shoulders in our series, the difference between the RSA angle and the RSA 29 angle exceeded 5°.

CONCLUSION

The RSA angle is a reproducible measure of the inclination of the inferior part of the glenoid that is reliable in most cases for glenoid baseplates of 24-25 mm in height. However, surgeons should be aware that the RSA angle may overestimate the superior orientation of the inferior glenoid for baseplates of different sizes or for small- or large-stature patients. In these cases, the relative RSA angle adapted to the size of the baseplate more accurately evaluates the inclination of the inferior glenoid.

Augmented baseplates in reverse shoulder arthroplasty: a systematic review of outcomes and complications

Background

Glenoid wear secondary to primary osteoarthritis or rotator cuff arthropathy is an obstacle commonly encountered by surgeons performing reverse shoulder arthroplasty, with numerous techniques devised to address this finding. The most recent of such techniques is the introduction of augmented glenoid baseplates to fill these glenoid defects. The objectives of this systematic review are to analyze clinical outcomes of augmented baseplates in patients with glenoid wear, including pain, range of motion, patient-reported functional scores, radiographic outcome measures, complication rates, and revision rates.

Methods

Three online databases (Ovid Medline, EMBASE, Pubmed) were searched for studies publishing clinical and functional outcomes of augmented baseplates in primary reverse shoulder arthroplasty. Findings were aggregated and frequency-weighted means of these variables were calculated when applicable.

Results

Seven studies comprising 810 patients were included in this review. The mean patient age was 72.1 ± 8.1 years with an average follow-up time of 41.4 months. Frequency-weighted means of improvement in forward elevation, abduction, and active external rotation were 53°, 47°, and 19°, respectively. Patients experienced American Shoulder and Elbow Surgeons, Simple Shoulder Test, and Constant score improvements of 45.9, 5.9, and 33.7, respectively. Pooled complicated rate was 6.4%, with 10 cases of baseplate loosening and 3 cases of instability. Five (0.6%) patients required reoperation. Subdividing among augment type (posterior, superior, posterosuperior), there were no apparent differences in outcomes or complication rates between directional augments.

Conclusion

This systematic review demonstrates that augmented baseplates for reverse shoulder arthroplasty provide positive outcomes both clinically and functionally at early follow-up. Complications are within an acceptable range for primary reverse shoulder arthroplasty, with a low rate of revision. Augmented baseplates should serve as a viable option for surgeons seeking to address glenoid wear during reverse shoulder arthroplasty.

[Bony glenoid reconstruction in revision arthroplasty]

Glenoid pathologies are one of the main indications for shoulder arthroplasty revisions. In most cases, the glenoid bone defect is associated with insufficiency of the rotator cuff, so that only reverse total shoulder arthroplasty can be considered as a revision implant. For stable permanent fixation of the reverse glenoid component, to avoid inferior glenoid notching, and to achieve optimal function, physiological restoration of three-dimensional glenoid anatomy is necessary. In order to approach the individual glenoid pathologies in a differentiated and optimal manner, it is important to classify the defects. A basic distinction must be made between centric contained and eccentric uncontained defects. Combinations often occur. It is also important to consider the severity, depth, and three-dimensional orientation of the defect. Therefore, a CT analysis of the glenoid is essential preoperatively. The data obtained should serve as the basis for computer-assisted planning to determine the optimal position of the glenoid baseplate and the type and shape of the bone graft for the reconstruction. For patients with good bone quality, we recommend defect reconstruction with autologous iliac crest. The type of graft configuration and fixation and the decision between a one- and two-stage procedure depend on the type and severity of the defect. With technically correct reconstruction and proper prosthesis implantation, sufficient integration of the bone graft and durable fixation of the glenoid component can be expected with satisfactory clinical results. After bony reconstruction of the defects, repeated treatment with a reverse arthroplasty is possible in the long term in the event of renewed glenoid problems.

[Metal glenoid augmentation in revision arthroplasty]

Glenoid implantation in revision arthroplasty of the shoulder remains a technical challenge in the case of severe bone loss. Metal glenoid augmentation and patient-specific glenoid implants represent new treatment options with great potential. Virtual planning techniques allow a differentiated evaluation of the extent of the bone loss and the planning of different augmentation options. Although not clearly defined so far, a patient-specific implant can be indicated if adequate fixation of the base plate in the native bone appears questionable. The planning is carried out with the support of the prostheses manufacturer and the stability is simulated using finite element analysis. A high level of primary stability is achieved by an optimized fitting of the implant into the bony defect. The short-term results are promising. However, in the absence of long-term results and limited options in case of revision, the use of a custom-made glenoid warrants a strict indication.

Analysis and 3D correction of glenoid dysplasia with metal hemi-wedge base plate augment: short-term radiographic outcomes

BACKGROUND

Glenoid defects can be addressed traditionally by asymmetric reaming or by bone-preserving correction to a more lateral joint line by bone or metal augmented baseplates in reverse shoulder arthroplasties. While there is more evidence in literature regarding the outcome and complications of Bony Increased Offset Reversed Shoulder Arthroplasty (BIO-RSA), there is minimal reported experience with the outcome after metal glenoid augments. The aim of this study was to determine whether a metal augment can correct the glenoid deformity in an anatomic manner.

METHODS

Glenoid morphology and deformity were determined in 50 patients with Walch type B1, B2, D and Favard type E0-E3 glenoid defects using preoperative radiographic and computed tomography (CT) analysis. All patients received a preoperative planning CT with 3D planning, and measurements of glenoid inclination (in 3 planes proximal, middle, distal), reversed shoulder arthroplasty angle (RSA) and glenoid version were obtained. All patients had a pathologic inclination in the coronal or frontal planes of > 10°. Above the threshold of 10° pathological glenoid version or inclination metal hemi-augments of 10°, 20°, or 30° were used which allow an individual 360° augment positioning according to the patient glenoid deformity.

RESULTS

The mean preoperative numbers of the glenoid version demonstrate that most glenoids were in retroversion and superior inclination. In total 2410° wedges, 1820° wedges and 8 30° wedges were used. In the majority of cases, the wedge was positioned posteriorly and/or cranially between 10:00 and 12:00 o'clock, which allows a correction in a 3D manner of the glenoid inclination and version. The mean RSA angle could be corrected from 22.76 ± 6.06 to 0.19° ± 2.7 (p < 0.0001). The highest retroversion of the glenoid is evidenced in the proximal section and it could be corrected from - 23.32° ± 4.56 to - 6.74° ± 7.75 (p < 0.0001) and in the middle section from - 18.93° ± 3.35 to - 7.66° ± 5.28 (p < 0.0001). A mean sphere bone overhang distance (SBOD) of 5.70 ± 2.04 mm was found in order to avoid or minimize relevant scapular notching.

CONCLUSION

By using a new 360° metal-augmented baseplate, the preoperative pathological inclination and retroversion can be corrected without medialization of the joint line. Future clinical results will show whether this bone-preserving procedure improves also the clinical outcomes as compared to asymmetric medialized reaming or wedged BIO-RSA.

LEVEL OF EVIDENCE

Level IV, Case series.

3D Printed Patient-Specific Cutting Guides for Bone Grafting in Reverse Shoulder Arthroplasty: A Novel Technique

Glenoid bone loss remains a challenge in shoulder arthroplasty. Addressing substantial bone loss is essential to ensure proper function and stability of the shoulder prosthesis and to prevent baseplate loosening and subsequent revision surgery. Current options for creating and shaping glenoid bone grafts include free-hand techniques and simple reusable cutting guides that cut the graft at a standard angle. There is currently no patient-specific device available that enables surgeons to accurately prepare the bone graft and correct glenoid deformity. We present a novel surgical technique using three-dimensional (3D)-printed cutting guides to create a patient-specific bone graft to address glenoid deformity in the setting of reverse shoulder arthroplasty.

Does improved external rotation following reverse shoulder arthroplasty impact clinical outcomes in patients with rotator cuff pathology and external rotation less than 0°?

BACKGROUND

The purpose of this study was to (1) evaluate whether improved external rotation (ER) in patients with preoperative ER <0° impacts their clinical outcomes following reverse shoulder arthroplasty (RSA) for rotator cuff (RC) pathology and (2) describe the differences in preoperative factors and postoperative outcomes in this patient population. Our hypothesis was that clinical outcomes would not be affected by improvement in ER using a lateralized glenosphere design.

METHODS

We retrospectively reviewed 55 patients with preoperative ER <0° who underwent primary RSA for RC pathology with lateralized glenosphere. Pre- and postoperative physician-reported ER was blindly measured using a videographic review of patients externally rotating their arm at the side. Patients were evaluated using 5 different patient-reported outcome score thresholds, measured at 12 months postoperatively: (1) minimal clinically important difference (MCID) for American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) scores (ie, ≥20-point increase); (2) MCID for Simple Shoulder Test (SST) scores (≥2.4-point increase); (3) visual analog scale (VAS) for pain score >0; (4) mean ASES score (≥75); and (5) mean SST score (≥6.8), each of which was used to stratify the patients into 2 groups-greater than or equal to vs. less than the threshold. This resulted in 5 different evaluations comparing the 2 groups for any difference in postoperative ER or preoperative factors, including Hamada and Goutallier scores.

RESULTS

Regardless of the measured outcome, there was no difference in either postoperative physician- or patient-reported ER between patients who achieved scores higher or lower than the thresholds. Both Hamada and Goutallier score distributions were not different between groups across all the evaluated outcomes. Patients who achieved the MCID for ASES had worse preoperative VAS pain (7 vs. 4, P = .011) and SST (1 vs. 3, P = .020) scores. Across all outcome thresholds, except MCID for SST, pain reduction (ΔVAS) was significantly more pronounced in patients exceeding the thresholds. Improved forward flexion rather than ER was observed in those who achieved the ASES (160° vs. 80°, P = .020) and SST MCIDs (150° vs. 90°, P = .037). Finally, patients who exceeded the thresholds experienced higher satisfaction rates.

CONCLUSION

Improvement in ER does not appear to impact patient-reported outcome measures, including ASES and SST in patients with preoperative ER <0° undergoing RSA with a lateralized glenosphere. Patients with more severe pain and worse function at baseline experience less postoperative pain and clinically significant improvement in their reported outcomes.

Management of glenoid bone loss in primary reverse shoulder arthroplasty

Aims

Rates of reverse total shoulder arthroplasty (rTSA) continue to grow. Glenoid bone loss and deformity remains a technical challenge to the surgeon and may reduce improvements in patients’ outcomes. However, there is no consensus as to the optimal surgical technique to best reconstruct these patients’ anatomy. This review aims to compare the outcomes of glenoid bone grafting versus augmented glenoid prostheses in the management of glenoid bone loss in primary reverse total shoulder arthroplasty.

Methods

This systematic review and meta-analysis evaluated study-level data in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We performed searches of Medline (Ovid), Embase (Ovid), and PubMed from their dates of inception to January 2022. From included studies, we analyzed data for preoperative and postoperative range of motion (ROM), patient-reported functional outcomes, and complication rates.

Results

A total of 13 studies (919 shoulders) were included in the analysis. The mean age of patients at initial evaluation was 72.2 years (42 to 87), with a mean follow-up time of 40.7 months (24 to 120). Nine studies with 292 rTSAs evaluated the use of bone graft and five studies with 627 rTSAs evaluated the use of augmented glenoid baseplates. One study was analyzed in both groups. Both techniques demonstrated improvement in patient-reported outcome measures and ROM assessment, with augmented prostheses outperforming bone grafting on improvements in the American Shoulder and Elbow Surgeons Score. There was a higher complication rate (8.9% vs 3.5%; p < 0.001) and revision rate among the bone grafting group compared with the patients who were treated with augmented prostheses (2.4% vs 0.6%; p = 0.022).

Conclusion

This review provides strong evidence that both bone graft and augmented glenoid baseplate techniques to address glenoid bone loss give excellent ROM and functional outcomes in primary rTSA. The use of augmented base plates may confer fewer complications and revisions. Cite this article: Bone Joint J 2022;104-B(12):1334–1342.

Baseplate retroversion does not affect postoperative outcomes after reverse shoulder arthroplasty

BACKGROUND

There is concern that excessive glenoid component retroversion leads to altered biomechanics and baseplate failure in reverse shoulder arthroplasty (RSA). However, much of this has been rooted in the total shoulder arthroplasty experience. In the current literature, it is not well defined whether glenoid baseplate positioning in reverse arthroplasty affects functional outcomes. Our practice has been to preserve glenoid bone stock without aiming for a certain degree of retroversion. We aimed to evaluate the correlation between pre- and postoperative retroversion in a cohort of RSAs and determine the effect of glenoid retroversion on functional outcomes, range of motion, and postoperative complications.

METHODS

A retrospective review of patients who had an RSA between 2017 and 2019 was performed. Preoperative computed tomography scans were used to assess preoperative retroversion, and axillary radiographs were used for postoperative retroversion. Outcome measures included American Shoulder and Elbow Surgeons score, visual analog scale for pain score, Single Assessment Numeric Evaluation score, range of motion, radiographic lucency, and complications.

RESULTS

A total of 271 patients were eligible for the study. There was a 76.9% 2-year follow-up rate. In total 161 patients had postoperative retroversion ≤15° (group A), and 110 patients had retroversion >15° (group B). There were no significant differences in American Shoulder and Elbow Surgeons, visual analog scale, or Single Assessment Numeric Evaluation scores. There were also no significant differences in postoperative range of motion. There was 1 baseplate failure in each group, and there was 1 patient in group B with asymptomatic radiographic loosening (baseplate at risk). The mean change in pre- to postoperative retroversion was 1° and 4° in groups A and B, respectively.

CONCLUSION

There was no significant difference in postoperative functional outcomes, range of motion, or complications between patients who had baseplate retroversion ≤15° vs. those who had retroversion >15°.

Considerations for Shoulder Arthroplasty Implant Selection in Primary Glenohumeral Arthritis With Posterior Glenoid Deformity

Glenoid deformity has an important effect on outcomes and complication rates after shoulder arthroplasty for primary glenohumeral arthritis. The B2/B3 glenoid has particularly been associated with a poorer outcome with shoulder arthroplasty compared with other glenoid types. One of the primary challenges is striking a balance between deformity correction and joint line preservation. Recently, there has been a proliferation of both anatomic and reverse implants that may be used to address glenoid deformity. The purpose of this review was to provide an evidence-based approach for addressing glenoid deformity associated with primary glenohumeral arthritis.

Can surgeons optimize range of motion and reduce scapulohumeral impingements in reverse shoulder arthroplasty? A computational study

BACKGROUND

Early glenohumeral impingement leads to poor range of motion and notching in reverse shoulder arthroplasty. The aim was to find from planning software which implant configuration provides the best motions in reverse shoulder arthroplasty.

PATIENTS AND METHODS

Reverse shoulder arthroplasty planning (Glenosys) was made in 31 patients (12 men, 19 women, 76 ± 6 yo) and impingements were analyzed. Inlay (155°-inclined) and Onlay (145°-inclined) humeral designs were tested. Four configurations were tested for each shoulder: "INLAY": non-lateralized glenoid-inlay humerus, "BIO-INLAY": lateralized glenoid (BIO-RSA)-inlay humerus, "ONLAY": non-lateralized glenoid-onlay humerus, and "BIO-ONLAY": lateralized (BIO-RSA) glenoid-onlay humerus.

RESULTS

BIO-ONLAY and BIO-INLAY groups presented a significantly better result in all tested motion (p < 0.001 for all tests). BIO-ONLAY allowed a significantly better external rotation, extension and adduction than BIO-INLAY with decreased impingements with the pilar. BIO-INLAY presented a significantly better abduction. In abduction, an abutment of the greater tuberosity against the acromion was associated with a lower range of motion (p < 0.0001) and did not depend on the lateralization.

CONCLUSION

Glenoid lateralization delays the glenohumeral impingement in reverse shoulder arthroplasty and gives the best rotations, adduction and extension when associated with neutral inclination and humeral 145° inclination. Greater tuberosity abutment has to be avoided in abduction and the Inlay design provides the best abduction.

Treatment options for complex shoulder osteoarthritis with posterior humeral head subluxation and glenoid bone loss (Walch B): A systematic review

Background

Shoulder osteoarthritis (OA) with eccentric (B) glenoids has generally been associated with poor patient-reported outcomes and increased complications. The purpose of this study was to outline all the described treatment options and their outcomes and complications in order to better guide treatment.

Methods

This systematic review was performed according to the Preferred Reporting Items for Systematic review and Meta-analysis guidelines. Searches were performed up to December 19, 2019, using Medline, EMBASE, Scopus, and Cochrane databases. Inclusion criteria included studies for glenohumeral OA reporting posterior humeral head subluxation and/or posterior glenoid erosion. Studies were excluded if they were review papers, abstracts, or conference papers; had heterogeneity of included Walch types; or were not written in English.

Results

Twenty-one studies met inclusion criteria. The mean follow-up duration was 47.5 months (range, 14-300), and the mean patient age 62 years (38-88). Six different discernible techniques were identified: asymmetric reaming with onlay glenoid (AROG) in 267 shoulders, posterior glenoid bone grafting (PGBG) with onlay glenoid in 79 shoulders, augmented glenoid (AG) in 160 shoulders, reverse shoulder arthroplasty (RSA) with or without bone grafting in 118 shoulders, hemiarthroplasty with concentric reaming (HACR) in 57 shoulders, and humeral head arthroplasty with inlay glenoid (HAIG) in 36 shoulders. All techniques reported improved patient outcomes and range of motion. Short-term (<5 years) studies reported glenoid loosening leading to revisions in 3% of AROG, 2.7% PGBG, 0.8% AG, 1.4% RSA, and 0% HAIG shoulders. HACR had a high revision rate (12.3%) due to persistent pain and stiffness. Midterm (>5 years) studies demonstrated increased rates of glenoid loosening with AROG (14.5%), PGBG (21% loose, 23.8% "at risk"), and AG (18.9% "at risk"), as well as increased rates of subluxation or revision due to instability. HAIG did not demonstrate loosening, subluxation, or revision at 55.2 months.

Conclusion

Various techniques exist to manage complex primary glenohumeral OA with posterior subluxation and posterior glenoid erosion. Glenoid component survival is a concern with ASOG, PGBG, and AG. HACR has the highest early revision rate. RSA offers promising short-term and midterm results likely due to the advantage of more secure fixation as well as a constrained design to prevent posterior subluxation. HAIG has the lowest complication and revision rates although further long-term studies are needed.

Midterm clinical outcome of uncemented short-stem reversed shoulder arthroplasty

INTRODUCTION

While the incidence of reverse total shoulder arthroplasty (rTSA) is increasing constantly, newer implants with designs other than the classic Grammont geometry are gaining importance. More anatomic inclination angles and lateralization are supposed to have a positive impact on clinical results and complication rates. Presentation of midterm results therefore is important to support these assumptions. The aim of this study was to report the midterm clinical outcome of primary rTSA with an uncemented humeral short-stem prosthesis (USSP) with a humeral inclination angle of 145° and the analysis of different variables on the outcome.

METHODS

This is a retrospective study of all patients with primary rTSA using an USSP and a combined humeral inclination angle of 145° (Ascend™ flex, Stryker) with a minimum clinical follow-up of 2 years. The implant combines a 132.5° inclination for the humeral stem with an additional 12.5° for the polyethylene inlay. Primary outcomes were patient-reported outcome measures: ASES score, simple shoulder test (SST) and subjective shoulder value (SSV). Secondary outcomes were complication and revision rates. We analyzed different variables: preoperatively gender, age, indication for surgery and status of rotator cuff. Also, the glenoid morphology was classified according to Walch and a proximal humerus cortical bone thickness measurement (CBT avg) of 6 mm was used as a threshold for osteoporosis. Postoperatively, we analyzed different radiologic parameters: filling ratio, distalization and lateralization angles according to Boutsiadis.

RESULTS

A total of 84 out of 99 (85%) patients with a mean FU of 46.7 months (range 24-80 months) could be included: 62 women and 22 men with a mean age of 74.7 years. Mean ASES score significantly increased from 47 preoperatively to 85.8 at the last follow-up (p = 0.001). The postoperative SST reached an average of 65.3 and the mean SSV was 83%. None of the variable parameters analyzed could be identified as a risk factor for a lower outcome defined as a SSV < 70. Three patients (3.6%) had a complication: one incomplete lower plexus lesion, one dislocation and one major hematoma. Surgical revision was needed in two cases (2.4%).

CONCLUSION

The midterm clinical outcome of primary reverse total shoulder arthroplasty (rTSA) with an uncemented humeral short stem and a humeral inclination angle of 145° showed good-to-excellent results with a low complication and revision rate independent from a wide range of pre- and postoperative variables. PROMs are comparable to those reported for anatomic TSA with a low complication rate, different to historical studies especially with the Grammont design.

LEVEL OF EVIDENCE

Treatment study, Level IV.

The Y plane is a reliable CT-based reference for glenoid component positioning in shoulder arthroplasty

Purpose

To determine the reliability of anatomic references for mediolateral component positioning in shoulder arthroplasty.

Materials and methods

The computed tomography scans of 86 shoulders free of arthritic or anatomic deformities were studied. Two surgeons independently digitized a series of points, including the intersection of the 3 bone branches of the scapular spine (Y), the center of the glenoid surface (G), the most medial point of the scapula (MS), the cortical convergence (CC) of the anterior and posterior margins of the glenoid, the base of the coracoid (BC), the anterior (HA) and posterior (HP) margins of the subchondral bone.

Results

The mean mediolateral distances between G and Y, BC, CC were respectively − 19.6 mm, − 1.5 mm, and − 36.8 mm. The consistency of anatomic landmarks was greatest for Y (standard deviation (SD) =2.3 mm; interquartile range (IQR) =3 mm), compared to BC (SD = 4.6 mm; IQR = 7 mm), and CC (SD = 6.6 mm; IQR = 8 mm). The repeatability of anatomic landmarks was excellent for all measurements. The mean ratios (relative to humeral head size) of distances between G and Y, BC, CC were respectively − 0.45, − 0.04, and − 0.85. The consistency of ratios was greatest for Y (SD = 0.05; IQR = 0.06), compared to BC (SD = 0.11; IQR = 0.14), and CC (SD = 0.13; IQR = 0.17). The repeatability of ratios was excellent for Y and BC, while it was good for CC.

Conclusions

The Y-plane is a reliable reference for glenoid component positioning in shoulder arthroplasty, with a consistent distance from the center of the glenoid surface, and could therefore be suitable for preoperative planning.

Study design

Level III, comparative anatomic study.

Large Glenoid Defects Treated by Multiple Bioresorbable Pinning-Assisted Bone-Grafting in Reverse Shoulder Arthroplasty

Large glenoid defects pose problems in reverse shoulder arthroplasty (RSA)^1-4. Bone-grafting enables restoration of the glenoid, but outcomes of this procedure may be hampered by early instability, which can lead to implant malpositioning, and by graft resorption, which can lead to implant loosening^2-7. To combat these potential complications, we utilize multiple bioresorbable pinning (MBP) during the bone-grafting process, in which as many bioresorbable pins as required are inserted from whatever aspect of the graft is appropriate until initial stability of the graft is achieved¹. We retrospectively compared the various grafting techniques applied for various degrees of retroversion, concluding that MBP is better when retroversion is >30°¹. Treatment decisions are made according to the degree of preoperative retroversion. The MBS technique is indicated for type-2 and type-3 glenoid deformities. This technique is not only relatively safe-as it involves only the use of bioresorbable materials-but also yields improved graft incorporation and less glenoid loosening¹.

Description

This procedure is performed with the patient under general anesthesia and in the beach-chair position, via a deltopectoral approach. After placing the structural graft, 5 to 10 provisional 1.5-mm Kirschner wires are inserted through the graft up the medal cortical bone of the scapula. The Kirschner wires are subsequently replaced with bioresorbable (BR) pins (1.5-mm Fixsorb Pin; TEIJIN). If more wires are needed, another set of 4 to 5 RB pins is inserted to gain initial stability. After placing the graft, the glenoid component is implanted as usual.

Alternatives

Traditionally, 1 or 2 screws are inserted in the periphery of the graft to obtain stability. The screws either must be inserted at an angle that does not impede placement of the implant² or are removed before the placement of the glenoid implant. One or a maximum of 2 long screws are inserted through the graft and glenoid³, meaning that the screw(s) must be aimed at a very narrow space between the central post and screws. Otherwise, these screws will represent an obstacle to the placement of the glenoid implant.

Rationale

In addition to facilitating initial graft stability, this procedure promotes graft incorporation. Typically, when performing this procedure, a total of 15 to 20 temporary Kirschner wires are placed in sets, with 5 to 7 wires per set. Of these, the most stable wires, usually 8 to 10 in total, are replaced by BR pins. The resultant bone holes, whether filled or unfilled with the BR pins, may promote neovascularization and osteoinduction, enabling long-lasting remodeling of and improved incorporation of the bone graft.

Expected Outcomes

A prior study compared the use of MBP versus angulated bony-increased offset (BIO) graft, assessing graft incorporation according to the size of the remaining graft on axial radiographs, with full incorporation defined as >75% of the original graft size^1,2. In that study, all 13 patients in the MBP group showed full graft incorporation compared with only 9 (47%) of 19 patients in the angulated BIO group (p < 0.001)¹.

Important Tips

Expose all 4 quadrants of the glenoid in cases of type-2 deformity. Accurate orientation of the MBP is important.Expose the upper and lower 2 quadrants of the glenoid in cases of type-3 deformity. The bases of the scapular spine and axillary border serve as a graft scaffold.Preserve circumferential soft tissues in cases of type-3 deformity because these tissues will serve to contain cancellous bone graft.Keep the Kirschner wire that extends the most medially (reaching the most medial cortical bone of the scapula) as a future guidewire for drilling of the central peg hole.

Acronyms and Abbreviations

RSA = reverse shoulder arthroplastyMBP = multiple bioresorbable pinningBIO = bony-increased offsetBR = bioresorbableTSA = total shoulder arthroplastyCT = computed tomographyK-wire = Kirschner wireROM = range of motionP.O. = postoperative.

Lateralized glenosphere reverse shoulder arthroplasty: inlay and onlay designs have similar clinical outcomes in patients with glenohumeral osteoarthritis

BACKGROUND

Whether or how the position of the humeral tray (inlay or onlay) in reverse shoulder arthroplasty (RSA) affects outcomes is unclear. Our goal was to compare the clinical and radiographic results of RSA systems with inlay vs. onlay designs but with similar neck shaft angles (NSAs) and lateralized glenospheres.

METHODS

We screened the institutional database at our tertiary academic center for patients who underwent primary RSA (with a lateralized glenosphere and a 135° NSA) from 2009 through 2017. The indication for surgery was glenohumeral osteoarthritis with glenoid bone loss (Walch classification A2, B2, B3, or C) and an intact rotator cuff. All patients were followed for a minimum of 2 years (mean, 47 months; range, 24-123 months). The humeral tray design was inlay for 79 patients and onlay for 71. All patients underwent preoperative and postoperative evaluations, including physical examination, radiography, and patient-reported outcome measures (visual analog scale for pain, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, and Western Ontario Osteoarthritis of the Shoulder index).

RESULTS

Compared with preoperative values, both groups achieved minimal clinically important differences in range of motion and patient-reported outcomes at the final follow-up. We found no significant differences between groups in any of these measures at the final follow-up. Rates of revision (inlay, 3.8% vs. onlay, 1.4%), scapular notching (inlay, 5.1% vs. onlay, 7.0%), acromial stress fracture (inlay, 0% vs. onlay, 2.8%), and tuberosity resorption (inlay, 25% vs. onlay, 27%) were not significantly different between groups (all, P > .05).

CONCLUSION

For patients with glenohumeral osteoarthritis with glenoid bone loss and an intact rotator cuff who underwent RSA using a lateralized glenosphere prosthesis with a 135° NSA, there were no significant differences between the inlay and onlay groups for range of motion, patient-reported outcomes, or complication rates. These findings are limited to this off-label indication for RSA.

Bony increased-offset reverse shoulder arthroplasty vs. metal augments in reverse shoulder arthroplasty: a prospective, randomized clinical trial with 2-year follow-up

BACKGROUND

Reverse shoulder arthroplasty (RSA) is rapidly being adopted as the standard procedure for a growing number of shoulder pathologies. Lateralization of the glenoid component is known to reduce the incidence of scapular notching and possibly improve postoperative range of motion. A number of methods are used for glenoid component lateralization, including bony increased-offset reverse shoulder arthroplasty (BIO-RSA) and porous metal-augmented baseplates. Presently, there exists little comparative literature on bone vs. metal lateralization. Therefore, the purpose of this study was to compare BIO-RSA to metal-augmented glenoid baseplates by assessing clinical outcomes and baseplate migration using model-based radiostereometric analysis.

METHODS

A power analysis indicated 40 patients would be required for this radiostereometric study. Therefore, 41 shoulders were prospectively randomized to receive either glenoid bone grafting (BIO-RSA) or a porous metal-augmented wedge-shaped titanium baseplate for primary reverse shoulder arthroplasty. At the time of primary surgery, all patients also underwent implantation of 8 tantalum marker beads in the glenoid and coracoid. Following surgery, participants were imaged using a calibrated, stereo radiographic technique. Radiographs were acquired at 6 weeks (baseline), 3 months, 6 months, 1 year, and 2 years postoperatively. Migration of the prosthesis was compared between bone and metal lateralization groups at each time point using a mixed effects model with Bonferroni test for multiple comparisons. Outcome measures were acquired preoperatively and 2 years postoperatively.

RESULTS

No significant differences were observed along any translation or rotation axis at any time point for either glenoid fixation group (P ≥ .175). Mean total glenoid component translation (± standard deviation) 2 years postoperatively was 0.4 ± 0.2 mm and 0.5 ± 0.3 mm for BIO-RSA and metal-augmented baseplates, respectively (P = .784). No significant differences were observed between groups in active range of motion; pain; American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form score; Simple Shoulder Test score; Disabilities of the Arm, Shoulder, and Hand score; Constant Shoulder score; or Subjective Shoulder Value (P ≥ .117), with the exception of increased active external rotation in the BIO-RSA cohort (P = .036).

CONCLUSION

This randomized clinical trial assessed reverse shoulder arthroplasty glenoid component migration using model-based radiostereometric analysis. At 2-year follow-up, our results indicate both BIO-RSA and porous metal wedge augmented baseplates provide stable initial fixation, which is maintained at 2 years' follow-up, with no substantial differences in clinical outcomes.