Five-year minimum clinical and radiographic outcomes of total shoulder arthroplasty using a hybrid glenoid component with a central porous titanium post

Anatomic glenohumeral arthroplasty: State of the art

Anatomical total shoulder arthroplasty in its modern form where it reproduces the normal shoulder has been utilized clinically for more than half a century. As the technology and the designs have changed to recreate the humeral and glenoid sides of the joint, the sophistication of design has resulted in the growing number of cases annually worldwide. This increase is due in part to the increasing number of indications that the prosthesis can treat with successful results. On the humeral side, there have been design changes to better reflect the proximal humeral anatomy, and humeral stems are increasingly placed safely without cement. Platform systems which allow conversion of a failed arthroplasty to a reverse configuration without stem extraction is another design change. Similarly, there has been increasing utilization of short stem and stemless humeral components. Extensive experience with shorter stem and stemless devices, however, has yet to demonstrate the purported advantages of these devices, as recent studies have demonstrated equivalent blood loss, fracture rates, operative times, and outcome scores. Easier revision with these shorter stems remains to be definitively established, with only one study comparing the ease of revision between stem types. On the glenoid side, hybrid cementless glenoids, inlay glenoids, cementless all-polyethylene glenoids, and augmented glenoids have all been investigated; however, the indications for these devices remain unclear. Lastly, innovative surgical approaches to implanting shoulder arthroplasty and the use of patient specific guides and computerized planning, while interesting concepts, still await validation before they are utilized on a widespread basis. While reverse shoulder arthroplasty has been increasingly used to reconstruct the arthritic shoulder, anatomic glenohumeral replacement maintains a significant role in the armamentarium of the shoulder surgeon.

Comparison of long-term clinical and radiological outcomes for cemented keel, cemented peg, and hybrid cage glenoids with anatomical total shoulder arthroplasty using the same humeral component

Aims

The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system.

Methods

We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217).

Results

Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%).

Conclusion

These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids.

A comparison of pegged and keeled glenoid clinical outcomes at long-term follow-up after total shoulder arthroplasty

Background

The two main glenoid types used in total shoulder arthroplasty (TSA) are the pegged and keeled glenoid designs. We aimed to determine if a pegged glenoid is superior to a keeled glenoid at long-term follow-up as measured by range of motion (ROM), patient reported outcomes (PROs), and radiographic glenoid loosening.

Methods

We retrospectively reviewed all patients undergoing TSA by a single surgeon at an urban, academic hospital. The cohort was stratified into two groups based on glenoid type - one group consisting of keeled implants and a second group consisting of pegged implants. For each patient, forward elevation (FE), internal rotation (IR), external rotation (ER), visual analog scale (VAS), American Shoulder and Elbow Surgeons (ASES) shoulder score, and simple shoulder test (SST) scores were collected preoperatively and at the most recent follow-up visit. Radiographic variables included acromiohumeral interval (AHI) and glenoid loosening.

Results

After applying exclusion criteria, 144 TSAs were included in our study. Of these, 42 (29.2%) had keeled glenoids and 102 (70.8%) had pegged glenoids. Patients with a pegged glenoid implant were older (67.4 vs. 60.7 years; p < 0.001) and had a shorter follow-up time (9.3 vs. 14.4 years; p < 0.001) than patients with a keeled glenoid implant. At the most recent follow-up visit, there were no significant differences among postoperative FE, ER, AHI, or PROs. However, pegged glenoid implants provided significantly more internal rotation (T11 vs. L1; p = 0.010) and were less likely to show evidence of radiographic glenoid loosening (16.7% vs. 42.9%; p=<0.001). Revision rates were not significantly different between the pegged and keeled groups (6.9% vs. 14.3%; p = 0.158).

Conclusion

Although a pegged design correlated with superior internal rotation and less radiographic glenoid loosening, both pegged and keeled glenoid designs offered favorable long-term clinical outcomes following TSA over the long-term.

Clinical and radiographic outcomes of hybrid glenoid fixation with a central porous titanium post: analysis of 713 consecutive shoulders

BACKGROUND

Hybrid glenoid component fixation represents an emerging technology in total shoulder arthroplasty (TSA) design. However, there is a paucity of larger-scale studies reporting the outcomes following implantation of these components. This study aimed to determine the outcomes following primary TSA using hybrid glenoid component fixation with a central porous titanium post.

METHODS

A retrospective review of 2 institutional databases identified patients aged ≥ 18 years who underwent primary elective hybrid TSA between 2009 and 2018 with a minimum of 2 years of follow-up. Outcomes evaluated included the visual analog scale pain score, range of motion, American Shoulder and Elbow Surgeons (ASES) score, complications, and implant survivorship free from reoperation or revision. Postoperative imaging was assessed for glenoid radiolucent lines and evidence of aseptic glenoid component loosening (AGL).

RESULTS

A total of 713 shoulders in 666 patients with a mean age of 61 ± 6 years were included in the study at a mean follow-up period of 4.3 years (range, 2.0-9.1 years); male shoulders comprised 50.9% of shoulders. Notable clinical improvements were observed with respect to the visual analog scale pain score (7.0 to 1.4, P < .001), active forward elevation (91° to 155°, P < .001), active external rotation (21° to 50°, P < .001), and the ASES score (38.6 to 82.7, P < .001), with all exceeding the substantial clinical benefit threshold for TSA. The active internal rotation score also showed significant improvement (3.1 to 5.7, P < .001). Glenoid radiolucent lines were identified in 57 TSAs (8.2%), with 1 radiographically loose glenoid component (0.1%). There were 54 complications (7.6%), with postoperative rotator cuff tear as the most common complication (n = 15, 2.1%); only 4 cases (0.6%) of glenoid-related complications (AGL) were observed. The Kaplan-Meier rate of survival free from revision surgery was 98.7% at 1 year, 98.5% at 2 years, and 96.7% at 5 years.

CONCLUSIONS

Hybrid glenoid component fixation of anatomic TSA with a central porous titanium post demonstrated statistically significant and clinically meaningful improvements in pain, range of motion, and ASES scores. Although AGL remains a concern, only 0.6% of TSAs sustained glenoid-related complications at a mean follow-up period of 4.3 years and the rate of survivorship free from revision was 96.7% at 5 years. These favorable clinical findings support the theoretical advantages of hybrid glenoid fixation; however, large comparative investigations with long-term follow-up are needed to validate these results.

Finite element analysis to predict short and medium-term performance of the anatomical Comprehensive® Total Shoulder System

BACKGROUND

The number of Total Shoulder Arthroplasties (TSA) has increased in these last years with significant increase of clinical success. However, glenoid component loosening remains the most common cause of failure.

OBJECTIVE

In this study we evaluated the critical conditions to predict short and medium-term performance of the uncemented anatomical Comprehensive® Total Shoulder System using a finite element model that was validated experimentally.

METHODS

The finite element models of an implanted shoulder analysed included total shoulder components with pegs. The models were simulated in 3 phases of adduction: 45°, 60° and 90° to determine the most critical situation. Two different bone-implant fixation conditions were considered: post-surgery and medium term (2 years).

RESULTS

These show that the critical condition is for the shoulder in 90° adduction were the highest contact stress (70 MPa) was observed in the glenoid component. Relatively to the interface implant-bone strains, the maximum (-16000 µε) was observed for the short-term in the lateral region of the humerus. The highest micromotions were observed in the central fixation post of the glenoid component, ranging from 20 to 25 µm, and 325 µm in the lateral plane of the humeral component.

CONCLUSION

The predicted results are in accordance with clinical studies published and micromotions of the humeral component can be used to predict loosening and to differentiate shoulder implant designs.

Hybrid Glenoid Designs in Anatomic Total Shoulder Arthroplasty: A Systematic Review

BACKGROUND

Hybrid glenoid components in total shoulder arthroplasty (TSA) utilize both polyethylene and metal components to provide short-term stability and long-term biologic fixation through bone ingrowth.

QUESTIONS/PURPOSE

We sought to systematically review the literature for studies that assessed outcomes of TSA performed using hybrid glenoid components.

METHODS

PubMed, Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Embase were searched systematically for articles measuring clinical and patient-reported outcomes and rates of complication and revision following TSA using a hybrid glenoid component.

RESULTS

Seven studies with 593 shoulders were included in this review. The mean age of patients was 65 ± 1 years, and 46% of the population was male. Mean follow-up was 50 months (4.2 years). The overall complication rate was 7% and rate of revision was 2.5%; glenoid radiolucency was present in 33% of shoulders at mean follow-up of 50 months. Mean improvements in forward elevation, external rotation, internal rotation score, and abduction were 49°, 28°, 2 points, and 42°, respectively. Mean improvements in Constant, American Shoulder and Elbow Surgeons (ASES), and University of California, Los Angeles (UCLA) scores were 36 points, 52 points, and 17 points, respectively.

CONCLUSION

Our review found that TSA using hybrid glenoid components results in low rates of complication and revision at early follow-up. Long-term studies are warranted to understand more fully the role of hybrid glenoid components in TSA.

Mid-term results of Eclipse total shoulder arthroplasty

AIMS

The use and variety of stemless humeral components in anatomical total shoulder arthroplasty (TSA) have proliferated since their advent in 2004. Early outcomes are reassuring but independent mid-term results are scarce. This independent study reports a consecutive series of 143 Eclipse stemless shoulder prostheses with a minimum five-year (5 to 10) follow-up.

METHODS

Outcomes of 143 procedures undertaken for all indications in 131 patients were reviewed, with subset analysis of those for osteoarthritis (OA) (n = 99). The primary outcome was the Oxford Shoulder Score (OSS) at a minimum of five years. Secondary outcomes were ranges of motion and radiological analysis of humeral radiolucency, rotator cuff failure, and glenoid loosening.

RESULTS

Mean OSS at mean follow-up of 6.67 years (5.0 to 10.74) was 40.12 (9 to 48), with no statistically significant difference between those implanted for a non-OA indication and those for OA (p = 0.056) or time-dependent deterioration between two years and five years (p = 0.206). Ranges of motion significantly improved compared with preoperative findings and were maintained between two and five years with a mean external rotation of 38° (SD 18.1, 0 to 100) and forward elevation of 152° (SD 29.9, 90 to 180). Of those components with radiographs suitable for analysis (n = 83), 23 (28%) were found to have a least one humeral radiolucent line, which were predominantly incomplete, less than 2 mm, and in a single anatomical zone. No humeral components were loose. A radiolucent line was present around 22 (15%) of glenoid components, and 15 (10%) of components had failed. Rotator cuff failure was found in 21 (15%) components. The mean time to either glenoid or rotator cuff failure was greater than three years following implantation. Survivorship was 96.4% (95% CI 91.6 to 98.5, number at risk 128) at five years, and 94.3% (95% CI 88.2 to 97.3, number at risk 76) at seven years, both of which compare favourably with best results taken from available registries.

CONCLUSION

Functional and radiological outcomes of the Eclipse stemless TSA are excellent, with no loose humeral components at minimum five-year follow-up. The presence of radiolucent lines is of interest and requires long-term observation but does not impact on the clinical results. Of the eight revisions required, this was predominantly for glenoid and rotator cuff failure. Cite this article: Bone Joint J 2022;104-B(1):83-90.

Extra-short humeral heads reduce glenohumeral joint overstuffing compared with short heads in anatomic total shoulder arthroplasty

Background

Rotator cuff tears and glenoid loosening remain the two most common causes for revision after anatomic total shoulder arthroplasty. Oversizing of the humeral head leads to increased contact force across the glenohumeral joint and is hypothesized to contribute to clinical and radiographic failure. The purpose of this study is to compare the rate of radiographic overstuffing between standard short humeral heads and newer extra-short heads with decreased lateral offset.

Methods

Fifty-five consecutive anatomic total shoulder arthroplasties performed using extra-short humeral heads were retrospectively reviewed and compared with age- and sex-matched controls receiving standard short heads. A total of 110 postoperative radiographs were analyzed using the Iannotti's perfect circle method to compare the prosthesis' center of rotation (COR) with the native humeral head COR. A difference in the COR of >3.0 mm was considered malpositioned. Malpositioning medially was considered overstuffed, and malpositioning laterally was considered understuffed. The direction of displacement of malpositioned prostheses was categorized using a quadrant system. Furthermore, we used a novel method to evaluate medial and superior overstuffing by measuring the displacement between the anatomic and prosthetic head positions along perpendicular axes.

Results

Using the Iannotti's perfect circle method, 56% of heads were malpositioned. Overstuffing occurred more frequently with short heads compared with extra-short heads (47% vs. 4%, P < .001). Conversely, understuffing occurred more frequently with extra-short heads (47% vs. 15%, P = .001). Malpositioned extra-short heads were most frequently placed in the inferomedial quadrant (93% vs. 24%, P < .001), whereas malpositioned short heads were most commonly placed in the superomedial quadrant (56% vs. 7%, P < .001). Our novel measurement method demonstrated that extra-short heads reduced medial overstuffing (2.8 ± 2.8 mm vs. 0.3 ± 2.0 mm, P < .001). Both extra-short and short heads had similar rates of superior malpositioning (1.6 ± 2.2 mm vs. 1.4 ± 1.5 mm, P = .683).

Conclusion

Routine use of extra-short humeral head sizes reduces the rate of medial glenohumeral joint overstuffing but not superior malpositioning. This is hypothesized to improve clinical outcomes, but future studies are needed to assess the relationship between improved humeral head fit and clinical outcomes.

[Interpretation of 2020 American Academy of Orthopaedic Surgeons (AAOS) on the Management of Glenohumeral Joint Osteoarthritis Evidence-Based Clinical Practice Guideline]

Based on peer-reviewed systematic reviews and randomized controlled trials published between January 2000 and June 2019 with regards to the management of glenohumeral joint osteoarthritis (GJO), the American Academy of Orthopaedic Surgeons (AAOS) established the clinical practice guidelines for the treatment of GJO. The guidelines provided practice recommendations including risk factors, non-surgical treatment, surgical treatment, prosthesis selection, and perioperative management for GJO. The recommendations were graded according to different evidence strength. This paper interprets the guidline in order to provide reference for domestic medical workers.

Radiographic and clinical outcomes of second generation Trabecular Metal™ glenoid components in total shoulder arthroplasty

BACKGROUND

Total shoulder arthroplasty with second generation porous tantalum glenoid implants (Trabecular Metal™) has shown good short-term outcomes, but mid-term outcomes are unknown. This study describes the clinical, radiographic, and patient-rated mid-term outcomes of total shoulder arthroplasty utilizing cemented Trabecular Metal™ glenoid components.

METHODS

Patients who underwent anatomic total shoulder arthroplasty with cemented Trabecular Metal™ glenoid components for primary osteoarthritis were identified for minimum five-year follow-up. The primary outcome measure was implant survival; secondary outcome measures included patient-rated outcome scores, shoulder range of motion findings, and radiographic analysis.

RESULTS

Twenty-seven patients were enrolled in the study. Twenty-one patients had full radiographic follow-up. Mean follow-up was 6.6 years. There was 100% implant survival. Shoulder range of motion significantly improved and the mean American Shoulder and Elbow Society score was 89.8. There was presence of metal debris radiographically in 24% of patients. Twenty-nine percent of patients had evidence of radiolucency. Fourteen percent of patients had moderate superior subluxation.

CONCLUSION

Total shoulder arthroplasty with second generation cemented Trabecular Metal™ glenoid components yielded good outcomes at mean 6.6-year follow-up. Metal debris incidence and clinical outcomes were similar to short-term findings. The presence of metal debris did not significantly affect clinical outcomes. Continued observation of these patients will elucidate longer-term implant survival.

Articular Surface Failure of a Hybrid Anatomic Glenoid Component: A Case Report

CASE

We present a case of a 71-year-old woman with history of left-sided shoulder arthritis who underwent standard total shoulder arthroplasty using a novel hybrid glenoid component. After 3 years, she sustained traumatic dissociation of the interface between the polyethylene face and central titanium post, a unique failure mechanism of the hybrid glenoid component. This was successfully corrected through conversation to reverse shoulder arthroplasty (RSA). Follow-up after 2 years demonstrated marked improvement in pain and function.

CONCLUSION

Hybrid glenoid components present a unique failure mechanism as compared to traditional glenoid loosening and can be effectively corrected with RSA.

Articular surface failure in hybrid anatomic glenoid components: a unique failure mechanism

PURPOSE

Glenoid loosening is a common failure mechanism of anatomic total shoulder arthroplasty (TSA). New hybrid fixation glenoids allow bony ingrowth and decrease the rates of glenoid loosening. The purpose of this study is to describe a new failure mode of polyethylene dissociation from the ingrowth cage in a single implant design.

METHODS

A retrospective review was performed using an institutional shoulder arthroplasty database of a single hybrid cage glenoid (Exactech, Gainesville, FL). Implants demonstrating this failure mechanism were investigated.

RESULTS

Five out of 206 (2.4%) primary TSAs with cage glenoids performed at our institution and 2 referred for revision suffered glenoid articular face failure. Mean age was 57 (range 38-67 years). Two of 7 failures (29%) occurred secondary to trauma. Failure occurred at mean 14 months after index arthroplasty (range 0-30 months). Revision occurred at mean 24 months after index arthroplasty (range 6-39 months). Six of the 7 patients (86%) had posteriorly augmented glenoids. All 6 patients who had available pre-failure radiographs demonstrated off-axis deviation between the peripheral pegs and central cage (mean 4.8°, range 3°-6°), which may predispose the implant to failure by pre-stressing the material interface.

CONCLUSION

Failure between the glenoid articular face and the central ingrowth cage is a unique failure mechanism to modular hybrid ingrowth glenoids. We hypothesize that this is predisposed by off-axis drilling leading to pre-stressing of the material interface. Surgeons should be aware of the existence of this failure mechanism, particularly when seeing patients with acute pain after an otherwise unproblematic TSA.

Assessing the Value to the Patient of New Technologies in Anatomic Total Shoulder Arthroplasty

BACKGROUND

Publications regarding anatomic total shoulder arthroplasty (TSA) have consistently reported that they provide significant improvement for patients with glenohumeral arthritis. New TSA technologies that have been introduced with the goal of further improving these outcomes include preoperative computed tomography (CT) scans, 3-dimensional preoperative planning, patient-specific instrumentation, stemless and short-stemmed humeral components, as well as metal-backed, hybrid, and augmented glenoid components. The benefit of these new technologies in terms of patient-reported outcomes is unknown.

METHODS

We reviewed 114 articles presenting preoperative and postoperative values for commonly used patient-reported metrics. The results were analyzed to determine whether patient outcomes have improved over the 20 years during which new technologies became available.

RESULTS

The analysis did not identify evidence that the results of TSA were statistically or clinically improved over the 2 decades of study or that any of the individual technologies were associated with significant improvement in patient outcomes.

CONCLUSIONS

Additional research is required to document the clinical value of these new technologies to patients with glenohumeral arthritis.

LEVEL OF EVIDENCE

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

Hybrid fixation in anatomic shoulder arthroplasty: surgical technique and review of the literature

Hybrid constructs have been used as a primary fixation technique in primary anatomic total shoulder arthroplasty for more than a decade. A highly porous metal central peg, metal cage, or coatings attached to the surface of cemented polyethylene glenoid component have been used with the concept of providing an additional adjunct in promoting osseointegration, preventing glenoid component loosening, and promoting longer-term success. The purpose of this article is to analyze the published results, complications, as well as rate of revision using this form of glenoid fixation. In addition, key aspects of the surgical technique that may be considered to facilitate optimal results when hybrid fixation is considered in total shoulder arthroplasty are also reviewed.

The association between glenoid component design and revision risk in anatomic total shoulder arthroplasty

INTRODUCTION

Anatomic total shoulder arthroplasty (TSA) is a proven treatment for glenohumeral joint osteoarthritis, with superior results compared with hemiarthroplasty. However, glenoid component loosening remains a problem and is one of the most common causes of failure in TSA. Multiple component designs have been developed in an attempt to reduce loosening rates. The purpose of this study was to evaluate risk of revision after anatomic TSA according to the glenoid component design.

METHODS

We conducted a cohort study including patients aged ≥18 years who underwent primary elective TSA for the diagnosis of osteoarthritis between 2010 and 2017. Patients with missing implant information, who received stemless humeral implants, or who received augmented glenoid implants, were excluded. Glenoid component designs used were categorized into 4 mutually exclusive treatment groups: polyethylene central-pegged ingrowth, polyethylene-metal hybrid, polyethylene all-cemented pegged, and polyethylene cemented keeled. Multivariable competing risk regression was used to evaluate the risk of glenoid loosening as a cause-specific revision by the glenoid component design.

RESULTS

Of the 5566 TSA included in the final cohort, 39.2% of glenoid implants were polyethylene central-pegged ingrowth, 31.1% were polyethylene-metal hybrid, 26.0% were polyethylene all-cemented pegged, and 3.6% were polyethylene cemented keeled. At 6-year final follow-up, 4.1% of TSA were revised for any cause, and 1.4% for glenoid loosening. Compared with the polyethylene central-pegged ingrowth design, no difference in glenoid loosening revision risk was observed for the polyethylene-metal hybrid design (hazard ratio [HR] = 1.15, 95% confidence interval [CI] = 0.42-3.20). However, both the polyethylene all-cemented pegged (HR = 2.48, 95% CI = 1.08-5.66) and polyethylene cemented keeled (HR = 3.84, 95% CI = 1.13-13.00) designs had higher risks for revision due to glenoid loosening.

CONCLUSIONS

We observed glenoid component designs to be associated with differential risks in revision due to glenoid loosening with polyethylene all-cemented pegged glenoids and polyethylene cemented keeled glenoids having higher risks when compared with polyethylene central-pegged ingrowth glenoids. Surgeons may want to consider the glenoid component design when performing anatomic TSA.

Humeral stem lucencies correlate with clinical outcomes in anatomic total shoulder arthroplasty

Background

Humeral stem lucencies are uncommon after uncemented anatomic total shoulder arthroplasty (aTSA), and their clinical significance is unknown. This study compares clinical outcomes of aTSA with and without humeral stem lucencies.

Methods

Two-hundred eighty aTSAs using an uncemented grit-blasted metaphyseal-fit humeral stem between 2005 and 2013 were retrospectively evaluated for radiographic humeral stem lucencies. All shoulders were evaluated at a minimum 5-year follow-up from a multicenter database. Clinical outcomes included range of motion (ROM) and American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES) score, Constant score, University of California-Los Angeles Shoulder Score (UCLA), Simple Shoulder Test (SST), and Shoulder Pain and Disability Index (SPADI) scores. Postoperative radiographs were evaluated and complications were recorded.

Results

Two-hundred forty-three humeral stems showed no radiolucent lines. Among the 37 humeral stems with lucent lines, lines were most common in zones 8, 4, 7, and 3. Preoperative ROM and functional outcomes were similar between groups. Postoperative change in outcomes exceeded the minimal clinically important difference (MCID) for all ROM and outcomes in both groups. Postoperative change between groups showed no significant difference in ROM or outcome scores, but improved mean abduction exceeded the MCID in the patients without humeral lines. The complication rate after omitting patients with humeral loosening was higher in patients with humeral lucencies, as was the revision rate. There was also a higher glenoid-loosening rate in patients with humeral lucencies.

Conclusion

Humeral lucent lines after uncemented stemmed aTSA have a small negative effect on ROM and functional outcomes compared with patients without lucent humeral lines, which may not be clinically significant. The complication and revision rates were significantly higher in patients with humeral lucencies.

Total shoulder arthroplasty with hybrid fixation of glenoid components consisting of cementless porous metal pegs or cage along with cemented backside polyethylene surface: a systematic review

Recently, hybrid glenoid components have been developed, consisting of cementless highly porous metal central peg, monoblock keel or cage along with cemented backside polyethylene surface. The aims of this study were twofold: (1) to determine the revision and complication rates of hybrid glenoid components, consisting of porous metal pegs or coatings attached to the polyethylene, for aseptic loosening in TSA and (2) to evaluate the rate of radiolucent lines in patients who underwent TSA with hybrid glenoid components consisting of porous metal pegs or coatings attached to the polyethylene. The US National Library of Medicine (PubMed/MEDLINE), EMBASE and the Cochrane Database of Systematic Reviews were queried for publications utilizing the following keywords: "hybrid" OR "bone-ingrowth" OR "bone ingrowth" AND "TSA" OR "total" AND "shoulder" AND "arthroplasty" OR "replacement". Five articles were included for analysis (470 operated shoulders, mean follow-up: 47.5 months). The overall weighted mean modified methodology Coleman score was 51.2/100, indicating a moderate level of overall methodological quality. The survival rate of hybrid glenoid components was 97.4% (458 out of 470 cases), while the rate of glenoid-related complications was 2.8% (13 cases). Finally, there were 54 cases (out of 313 reported; 17.3%) with glenoid radiolucency (none of them required revision). TSA with hybrid fixation glenoid components was associated with high survivorship and low rate of glenoid component-related complications at 4 years mean follow-up. In addition, there was limited evidence to show that the short- to mid-term outcome of TSA using hybrid glenoid components is not inferior to the outcome of cemented all-polyethylene glenoid components.

Uncemented fixation of a monoblock ingrowth polyethylene glenoid: early follow-up

BACKGROUND

Traditional monoblock pegged glenoid components are implanted with cement, increasing operative time and potentially violating more bone than those inserted without cement. We study the early radiographic loosening and reoperation rate following uncemented fixation of a hybrid cage monoblock polyethylene glenoid component.

METHODS

Between 2013 and 2015, a total of 51 shoulders underwent anatomic shoulder arthroplasty (TSA) using a hybrid ingrowth cage polyethylene glenoid component by a single surgeon, with a minimum follow-up of 2 years. In all cases, the glenoid component was placed without cement. Mean follow-up was 33 months (range, 24-57). The primary outcome was Lazarus scale-assessed radiographic loosening. Secondary outcomes included reoperation, range of motion (ROM), and patient-reported outcome measures (PROMs).

RESULTS

Twelve glenoid components (24%) had radiolucent lines. Glenoid lines were rated grade 1, grade 2, and grade 5 (6, 4, and 2 shoulders, respectively). Six shoulders (12%) had humeral lucent lines. Two shoulders (4%) underwent reoperation, only 1 of these occurring due to isolated failure of the glenoid component. As a group, mean ROM and PROMs improved significantly compared with preoperative values and exceeded the minimal clinically important difference.

CONCLUSION

Glenoid loosening remains a major concern at mid- to long-term follow-up of TSA. Placement of this hybrid cage monoblock polyethylene glenoid component in a completely uncemented fashion does not lead to early clinical loosening, after which bony ingrowth into the central cage can be expected. Uncemented fixation of this hybrid cage component appears to be a safe treatment option for patients undergoing primary TSA.

The effect of radial mismatch on radiographic glenoid loosening

Background

Methods

Results

Discussion

Clinical and radiographic comparison of a hybrid cage glenoid to a cemented polyethylene glenoid in anatomic total shoulder arthroplasty

BACKGROUND

This study reports the clinical and radiographic outcomes of a hybrid cage glenoid compared with an age-matched, sex-matched, and follow-up-matched cohort of cemented all-polyethylene peg glenoids in patients undergoing anatomic total shoulder arthroplasty with 2 years' minimum follow-up.

MATERIALS AND METHODS

We reviewed 632 primary anatomic total shoulder arthroplasty patients from an international multi-institutional database; 316 patients received hybrid cage glenoids and were matched for age, sex, and follow-up with 316 patients with cemented all-polyethylene peg glenoids. Each cohort received the same humeral component. Scoring was performed in all patients preoperatively and at latest follow-up using 5 outcome scoring metrics and 4 active range-of-motion measurements. A Student 2-tailed unpaired t test identified differences in outcomes; P < .05 denoted a significant difference.

RESULTS

Cage glenoid patients had significantly lower rates of radiolucent glenoid lines (9.0% vs. 37.6%, P < .0001) and radiolucent humeral lines (3.0% vs. 9.1%, P = .0088) than all-polyethylene peg glenoid patients. In the cage glenoid cohort, 4 cases of aseptic glenoid loosening (1.3%) and 4 cases of articular surface dissociation (1.3%) occurred. In the all-polyethylene peg cohort, 12 cases of aseptic loosening (3.8%) occurred. Cage glenoid patients had a significantly lower revision rate than all-polyethylene peg glenoid patients (2.5% vs. 6.9%, P = .0088).

CONCLUSION

At 50 months' mean follow-up, cage glenoids demonstrated equally good clinical outcomes to all-polyethylene peg glenoids. Cage glenoids had significantly fewer radiolucent lines around both the glenoid and humeral components and a lower revision rate. Longer-term follow-up is required to confirm these promising short-term results.