Stability of cemented in-line pegged glenoid compared with keeled glenoid components in total shoulder arthroplasty

Mid- to long-term outcomes of a cemented, all-polyethylene pegged glenoid component in anatomic total shoulder arthroplasty

BACKGROUND

The primary aim of this study was to evaluate mid- to long-term survival of an all-polyethylene pegged glenoid component used in anatomic total shoulder arthroplasty (TSA). The secondary aim was to review clinical and radiologic outcomes.

METHODS

A retrospective analysis of a prospectively collected local arthroplasty register of consecutive patients undergoing TSA with an all-polyethylene pegged glenoid between January 2009 and December 2018 was undertaken. In total, 108 TSAs using this implant were performed in our unit in 98 patients (18 men and 80 women), with 10 patients undergoing bilateral TSA. The mean age at the time of the operation was 71.3 years (range, 44-87 years). The mean follow-up period was 5.1 years (range, 2-10.6 years). In addition to survival analysis, clinical evaluation included the postoperative Oxford Shoulder Score, Constant score, and visual analog scale (VAS) pain score, as well as range-of-motion assessment. Radiologic outcomes included an assessment of radiolucency based on the Lazarus grade.

RESULTS

Kaplan-Meier survival analysis revealed a 6-year survival estimate of 94.1% for all-cause revision. Revision was required in 6 patients: 4 for cuff failure and 2 for instability. At follow-up, the mean Oxford Shoulder Score was 38.2 (standard deviation [SD], 12.3); mean Constant score, 59.3 (SD, 17.0); and mean VAS pain score, 1.8 (SD, 2.5). Mean forward elevation at final follow-up was 111⁰ (SD, 26.6⁰); mean abduction, 102⁰ (SD, 34.0⁰). Clinical outcomes were maintained at long-term follow-up (>8 years), with the exception of the VAS pain score, which increased by 2.1 points (P = .034). Radiologic assessment revealed that 28 patients had radiolucency consistent with Lazarus grade ≥ 3 with clinical outcomes not being affected.

CONCLUSIONS

Mid- to long-term follow-up indicates a low revision rate and good clinical survivorship for cemented, all-polyethylene glenoid components. No patients, so far, have undergone revision for glenoid loosening, but radiographic follow-up has shown that 36% of these implants have signs of radiolucency. Further follow-up is required to determine longer-term survivorship.

Improved mechanical fixation of an all-polyethylene glenoid reduces postoperative radiolucent lines

BACKGROUND

The rationale for advances in implant design is to improve performance in comparison to their predecessors. The purpose of this study was to compare a newer, self-pressurizing peripheral peg glenoid to a traditional polyethylene pegged glenoid through biomechanical evaluation and a retrospective radiographic and clinical review.

METHODS

Three testing conditions (uncemented, partially cemented, and fully cemented) were chosen to assess the 2 component designs in a foam block model. The number of hammer hits to seat the component, amount of time to seat the component, and resistance-to-seat were collected. The implants were then cyclically loaded following ASTM F2028-17 testing standard. Clinically, postoperative radiographs of patients with a self-pressurized glenoid component (n = 225 patients) and traditional glenoid component (n = 206 patients) were evaluated for radiolucent lines and glenoid seating at various timepoints. Clinical outcomes (American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, Simple Shoulder Test, and visual analog scale pain scores) and complications were recorded. The presence of radiolucent lines at the bone-cement interface was evaluated using the Modified Franklin Grade and the Lazarus grade.

RESULTS

The self-pressurizing glenoid design required significantly more hammer hits than traditional glenoid designs in all groups tested (P < .029). Moreover, the self-pressurizing design had significantly more resistance-to-seat than traditional components in both the uncemented and partially cemented group (P < .002). No difference in resistance-to-seat was found between designs in the fully cemented group. The uncemented and partially cemented groups did not survive the full 50,000 cycles; however the self-pressurizing design had significantly less motion than the traditional design (P < .001). No differences between component designs were found in the fully cemented group at 50,000 cycles. The self-pressurizing glenoid component had 0.005% radiographic radiolucent lines, and the traditional glenoid component had 45% radiographic radiolucent lines, with 38% of the radiolucencies in the traditional glenoid component group being defined as grade E. There were no progressive radiolucencies, differences in clinical outcomes, or complications at 2 years postoperatively.

CONCLUSION

In the fully cemented condition, the 2 component designs had comparable performance; however, the differences in designs could be better observed in the uncemented group. The self-pressurizing all-polyethylene design studied has superior biomechanical stability. Clinically, the improved stability of the glenoid component correlated with a reduction of radiolucent lines and will likely lead to a reduction in glenoid component loosening.

Validation of a 3D CT imaging method for quantifying implant migration following anatomic total shoulder arthroplasty

Glenoid component loosening remains a common complication following anatomic total shoulder arthroplasty (TSA); however, plain radiographs are unable to accurately detect early implant migration. The purpose of this study was to validate the accuracy of a method of postoperative, three-dimensional (3D) computed tomography (CT) imaging with metal artifact reduction (MAR) to detect glenoid component migration following anatomic TSA. Tantalum bead markers were inserted into polyethylene glenoid components for implant detection on 3D CT. In-vitro validation was performed using a glenoid component placed into a scapula sawbone and incrementally translated and rotated, with MAR 3D CT acquired at each test position. Accuracy was evaluated by root mean square error (RMSE). In-vivo validation was performed on six patients who underwent anatomic TSA, with two postoperative CT scans acquired in each patient and marker-based radiostereometric analysis (RSA) performed on the same days. Glenoid component migration was calculated relative to a scapular coordinate system for both MAR 3D CT and RSA. Accuracy was evaluated by RMSE and paired Student's t-tests. The largest RMSE on in-vitro testing was 0.24 mm in translation and 0.11° in rotation, and on in-vivo testing was 0.47 mm in translation and 1.04° in rotation. There were no significant differences between MAR 3D CT and RSA measurement methods. MAR 3D CT imaging is capable of quantifying glenoid component migration with a high level of accuracy. MAR 3D CT imaging is advantageous over RSA because it is readily available clinically and can also be used to evaluate the implant-bone interface.

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.

Early fixation of the humeral component in stemless total shoulder arthroplasty : a radiostereometric and clinical study with 24-month follow-up

AIMS

Stemless humeral implants have been developed to overcome stem-related complications in total shoulder arthroplasty (TSA). However, stemless implant designs may hypothetically result in less stable initial fixation, potentially affecting long-term survival. The aim of this study is to investigate early fixation and migration patterns of the stemless humeral component of the Simpliciti Shoulder System and to evaluate clinical outcomes.

METHODS

In this prospective cohort study, radiostereometric analysis (RSA) radiographs were obtained in 24 patients at one day, six weeks, six months, one year, and two years postoperatively. Migration was calculated using model-based RSA. Clinical outcomes were evaluated using the visual analogue scale (VAS), the Oxford Shoulder Score (OSS), the Constant-Murley Score (CMS), and the Disabilities of the Arm, Shoulder and Hand (DASH) score.

RESULTS

At two years, median translation along the x-, y-, and z-axis was -0.12 mm (interquartile range (IQR) -0.18 to 0.02), -0.17 mm (IQR -0.27 to -0.09), and 0.09 mm (IQR 0.02 to 0.31). Median rotation around the x-, y-, and z-axis was 0.12° (IQR -0.50 to 0.57), -0.98° (IQR -1.83 to 1.23), and 0.09° (IQR -0.76 to 0.30). Overall, 20 prostheses stabilized within 12 months postoperatively. Four prostheses showed continuous migration between 12 and 24 months. At two-year follow-up, with the exception of one revised prosthesis, all clinical scores improved significantly (median VAS difference at rest: -3.0 (IQR -1.5 to -6.0); OSS 22.0 (IQR 15.0 to 25.0); CMS 29.5 (IQR 15.0 to 35.75); and DASH -30.0 (IQR -20.6 to -41.67) (all p < 0.001)) with the exception of one revised prosthesis.

CONCLUSION

In conclusion, we found that 20 out of 24 implants stabilized within 12 months postoperatively. The significance of continuous migration in four implants is unclear and future research on the predictive value of early migration for future loosening in TSA is required. Clinical results revealed a clinically relevant improvement. Cite this article: Bone Joint J 2022;104-B(1):76-82.

Stable glenoid component of reverse total shoulder arthroplasty at 2 years as measured with model-based radiostereometric analysis (RSA)

Background and purpose - Reverse total shoulder arthroplasty (TSA) is used for treating cuff arthropathy, displaced proximal humeral fractures (PHF), and in revision shoulder surgery, despite sparse evidence on long-term results. We assessed stability of the glenoid component in reverse TSA, using model-based RSA.Patients and methods - 20 patients (mean age 76 years, 17 female), operated on with reverse TSA at Oslo University Hospital, in 2015-2017 were included. Indications for surgeries were PHFs, malunion, cuff arthropathy, and chronic shoulder dislocation. RSA markers were placed in the scapular neck, the coracoid, and the acromion. RSA radiographs were conducted postoperatively, at 3 months, 1 year, and 2 years. RSA analysis was performed using RSAcore with Reversed Engineering (RE) modality, with clinical precision < 0.25 mm for all translations (x, y, z) and < 0.7° for rotations (x, z). Scapular "notching" was assessed in conventional radiographs.Results - 1 patient was excluded due to revision surgery. More than half of the patients displayed measurable migration at 2 years: 6 patients with linear translations below 1 mm and 8 patients who showed rotational migration. Except for one outlier, the measured rotations were below 2°. The migration pattern suggested implant stability at 2 years. 10 patients showed radiolographic signs of "notching", and the mean Oxford Shoulder Score (OSS) at 2 years was 29 points (15-36 points).Interpretation - Stability analysis of the glenoid component of reversed total shoulder arthroplasty using reversed engineering (RE) model-based RSA indicated component stability at 2 years.

Relationship Between Glenoid Component Shift and Osteolysis After Anatomic Total Shoulder Arthroplasty: Three-Dimensional Computed Tomography Analysis

BACKGROUND

The purpose of this study was to evaluate glenoid component position and radiolucency following anatomic total shoulder arthroplasty (TSA) using sequential 3-dimensional computed tomography (3D CT) analysis.

METHODS

In a series of 152 patients (42 Walch A1, 16 A2, 7 B1, 49 B2, 29 B3, 3 C1, 3 C2, and 3 D glenoids) undergoing anatomic TSA with a polyethylene glenoid component, sequential 3D CT analysis was performed preoperatively (CT1), early postoperatively (CT2), and at a minimum 2-year follow-up (CT3). Glenoid component shift was defined as a change in component version or inclination of ≥3° from CT2 to CT3. Glenoid component central anchor peg osteolysis (CPO) was assessed at CT3. Factors associated with glenoid component shift and CPO were evaluated.

RESULTS

Glenoid component shift occurred from CT2 to CT3 in 78 (51%) of the 152 patients. CPO was seen at CT3 in 19 (13%) of the 152 patients, including 15 (19%) of the 78 with component shift. Walch B2 glenoids with a standard component and glenoids with higher preoperative retroversion were associated with a higher rate of shift, but not of CPO. B3 glenoids with an augmented component and glenoids with greater preoperative joint-line medialization were associated with CPO, but not with shift. More glenoid component joint-line medialization from CT2 to CT3 was associated with higher rates of shift and CPO. A greater absolute change in glenoid component inclination from CT2 to CT3 and a combined absolute glenoid component version and inclination change from CT2 to CT3 were associated with CPO. Neither glenoid component shift nor CPO was associated with worse clinical outcomes.

CONCLUSIONS

Postoperative 3D CT analysis demonstrated that glenoid component shift commonly occurs following anatomic TSA, with increased inclination the most common direction. Most (81%) of the patients with glenoid component shift did not develop CPO. Longer follow-up is needed to determine the relationships of glenoid component shift and CPO with loosening over time.

LEVEL OF EVIDENCE

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

Statistical fragility of randomized clinical trials in shoulder arthroplasty

BACKGROUND

The P value is a statistical tool used to assess the statistical significance of clinical trial outcomes in orthopedic surgery. However, the P value does not evaluate research quality or clinical significance. The Fragility Index (FI) is an alternative statistical method that can be used to assess the quality and significance of clinical research and is defined as the number of patients in a study intervention group necessary to convert an outcome from statistically significant to statistically insignificant or vice versa. The primary purpose of this study was to evaluate the statistical robustness of clinical trials regarding shoulder arthroplasty using the FI. The secondary goal was to identify trial characteristics associated greater statistical fragility.

METHODS

A systematic review of randomized clinical trials in shoulder arthroplasty was performed. The FI was calculated for all dichotomous, categorical study outcomes discussed in the identified studies. Descriptive statistics and the Pearson correlation coefficient were used to evaluate all studies and characterize associations between study variables.

RESULTS

A total of 13 randomized controlled trials were identified and evaluated; these trials had a median sample size of 47 patients (mean, 54 patients; range, 26-102 patients) and a median of 7 patients (mean, 5.8 patients; range, 0-14 patients) lost to follow-up. The median FI was 6 (mean, 5; range, 1-11), a higher FI than what has been observed in other orthopedic subspecialties. However, the majority of outcomes (74.4%) had an FI that was less than the number of patients lost to follow-up, and most outcomes (89.7%) were statistically insignificant.

CONCLUSION

Randomized controlled trials in shoulder arthroplasty have comparable statistical robustness to the literature in other orthopedic surgical subspecialties. We believe that the inclusion of the FI in future comparative studies in the shoulder arthroplasty literature will allow surgeons to better assess the statistical robustness of future research.

Glenoid failure after total shoulder arthroplasty with cemented all-polyethylene versus metal-backed implants: a systematic review protocol

INTRODUCTION

Anatomical total shoulder arthroplasty (TSA) is an effective treatment adopted for patients with glenohumeral osteoarthritis (OA). The glenoid component failure is the main risk that occurs in this therapeutic choice; however, doubts remain regarding the selection of the best implant for avoiding complication. This systematic review aims to evaluate the glenoid component in TSA by comparing the complications of different types of implants.

METHODS AND ANALYSIS

A systematic review of randomised clinical trials or quasi-randomised trials will be performed by applying the Preferred Reporting Items for Systematic Review and Meta-Analysis protocols and comparing polyethylene (keeled and pegged) versus metal-backed implants in adult patients with glenohumeral OA. Our search strategy will be performed using MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, EMBASE and Web of Science. Data management and extraction will be performed using a data withdrawal form and by analysing study method characteristics, participant characteristics, intervention characteristics, results and methodological domains. The database search will be performed by February 2021. The Grading of Recommendations Assessment, Development and Evaluation will be used for assessing the quality of evidence of each study selected; however, some critical and important outcomes were determined such as the shoulder function through functional scores (Constant-Murley and American Shoulder and Elbow Surgeons), complications represented by pain (Visual Analogue Scale), surgical revision, radiograph radiolucency and loosening. The confidence in estimated effects for these outcomes will be applied as the overall confidence. The outcomes will be defined as early or late, according to the postoperative follow-up of less than or greater than 1 year, respectively, for complications and radiographs. For the shoulder function, follow-ups will be divided into 6, 12 and 24 months. Heterogeneity is expected in systematic reviews; therefore, the selection of outcomes, as well as the sample size, and specific statistical analysis can lead to meta-analysis; however, if it fails, narrative evidence synthesis will be conducted. Other analyses such as descriptive, subgroup and sensitivity analyses will be performed whenever possible. This systematic review will, therefore, provide evidence concerning the best clinical practice for avoiding complications.

ETHICS AND DISSEMINATION

This study has been approved by the Institutional Review Board of Universidade Federal de São Paulo (protocols 0725/2017, 2.157.415 and 70473017.5.0000.5505), and the findings will be disseminated through peer-reviewed publication and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42018079537.

An Assessment of Randomized Controlled Trial Quality in The Journal of Bone & Joint Surgery: Update from 2001 to 2013

BACKGROUND

The quality of reporting of randomized controlled trials (RCTs) published in The Journal of Bone & Joint Surgery (JBJS) from 1988 to 2000 was previously analyzed. The purpose of this current study was to analyze the quality of reporting of RCTs published in JBJS from 2001 to 2013 to identify trends over time and potential areas of improvement for future clinical trials.

METHODS

A manual search of the JBJS database identified RCTs published between January 2001 and December 2013. Quality assessments, using the Detsky quality-of-reporting index (Detsky score), a modified Cochrane risk-of-bias tool, and abstraction of relevant data identifying predictors of quality, were conducted.

RESULTS

A total of 5,780 publications were identified in JBJS from 2001 to 2013, with 285 RCTs (4.9%), representing an increase from the prior 13-year period. The overall mean transformed Detsky score (and standard error) increased significantly (p < 0.001) from 68.1% ± 1.67% to 76.24% ± 0.72%. The percentage of multicenter RCTs decreased from 67% to 31%. The percentage of positive trials also decreased from 80% to 50.5%, as did the mean sample size (212 to 166). Regression analysis indicated that trials with an epidemiologist as the first author and nonsurgical trials were significantly associated (p = 0.001) with a higher overall trial quality score. The categories of the lowest mean methodology scores were randomization and concealment, eligibility criteria, and reasons for patient exclusion, as identified with the Detsky score, and patient and assessor blinding, as identified with the risk-of-bias assessment.

CONCLUSIONS

The quantity and quality of published RCTs in JBJS have increased in the 2001 to 2013 time period compared with the previous time period. Although these improvements are encouraging, trends to smaller, single-center trials were also observed. To efficiently determine the efficacy of orthopaedic treatments and limit bias, high-quality randomized trials of appropriate sample size and rigorous design are needed.

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.

Intraoperative Efficiency in Contemporary Total Shoulder Arthroplasty: Is Manual Pressure During Cement Curing Still Necessary With Interference Fit Pegged Glenoids?

INTRODUCTION

No previous data have demonstrated the effect of manual pressure during cement curing on interference-fit glenoid implant fixation in total shoulder arthroplasty. In this study, we examined cement mantle characteristics and implant seating using two different methods of securing an interference-fit glenoid implant with peripheral cemented pegs: a manual pressure technique versus a pressureless technique.

METHODS

Sixteen cadaveric scapulae were harvested, and their glenoids were prepared for component insertion. Glenoids with an interference-fit central peg were cemented into the peripheral holes and fully seated. Two techniques were employed during cement curing: (1) a manual pressure technique (8 glenoids), which used a static 70 N load application to each implant for 10 minutes; and (2) a pressureless technique (8 glenoids), which used no pressure application, and the implant was left to set without intervention. Each glenoid was subsequently imaged using microcomputed tomography and analyzed for differences in cement mantle characteristics and implant seating.

RESULTS

The mean area of cement penetration for the manual pressure technique was not statistically different from the pressureless group (P = .26, valid N = 288). The average implant incongruity after final seating in the manual pressure group was 0.63 mm, compared with 1.0 mm in the pressureless group. A linear mixed effects model with a Kenward-Roger correction was used to compare the two groups, and no significant difference was found (Mdiff = -0.386, 95% confidence interval: -0.978 to 0.206; P = 0.17).

CONCLUSION

Manual pressure of the glenoid component during cement curing yielded no difference in the cement mantle area or final implant seating incongruity compared with a pressureless technique. This knowledge could potentially benefit both the surgeon and the patient by increasing the efficiency in total shoulder arthroplasty surgery.

Shoulder replacement surgery for osteoarthritis and rotator cuff tear arthropathy

BACKGROUND

Shoulder replacement surgery is an established treatment for patients with end-stage glenohumeral osteoarthritis or rotator cuff tear arthropathy who have not improved with non-operative treatment. Different types of shoulder replacement are commonly used, but their relative benefits and risks compared versus one another and versus other treatments are uncertain. This expanded scope review is an update of a Cochrane Review first published in 2010.

OBJECTIVES

To determine the benefits and harms of shoulder replacement surgery in adults with osteoarthritis (OA) of the shoulder, including rotator cuff tear arthropathy (RCTA).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, SportDiscus, and Web of Science up to January 2019. We also searched clinical trial registers, conference proceedings, and reference lists from previous systematic reviews and included studies.

SELECTION CRITERIA

We included randomised studies comparing any type of shoulder replacement surgery versus any other surgical or non-surgical treatment, no treatment, or placebo. We also included randomised studies comparing any type of shoulder replacement or technique versus another. Study participants were adults with osteoarthritis of the glenohumeral joint or rotator cuff tear arthropathy. We assessed the following major outcomes: pain, function, participant-rated global assessment of treatment success, quality of life, adverse events, serious adverse events, and risk of revision or re-operation or treatment failure.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We collected trial data on benefits and harms.

MAIN RESULTS

We included 20 studies involving 1083 participants (1105 shoulders). We found five studies comparing one type of shoulder replacement surgery to another type of shoulder replacement surgery, including three studies comparing conventional stemmed total shoulder replacement (TSR) surgery to stemmed humeral hemiarthroplasty. The remaining 15 studies compared one type of shoulder replacement to the same type of replacement performed with a technical modification or a different prosthetic component. We found no studies comparing shoulder replacement surgery to any other type of surgical treatment or to any type of non-surgical treatment. We found no studies comparing reverse total shoulder replacement surgery to any other type of treatment or to any type of replacement. Trial size varied from 16 to 161 participants. Participant mean age ranged from 63 to 81 years. 47% of participants were male. Sixteen trials reported participants with a diagnosis of osteoarthritis and intact rotator cuff tendons. Four trials reported patients with osteoarthritis and a rotator cuff tear or rotator cuff tear arthropathy. All studies were at unclear or high risk of bias for at least two domains, and only one study was free from high risk of bias (included in the main comparison). The most common sources of bias were lack of blinding of participants and assessors, attrition, and major baseline imbalance. Three studies allowed a comparison of conventional stemmed TSR surgery versus stemmed humeral hemiarthroplasty in people with osteoarthritis. At two years, low-quality evidence from two trials (downgraded for bias and imprecision) suggested there may be a small but clinically uncertain improvement in pain and function. On a scale of 0 to 10 (0 is no pain), mean pain was 2.78 points after stemmed humeral hemiarthroplasty and 1.49 points lower (0.1 lower to 2.88 lower) after conventional stemmed TSR. On a scale of 0 to 100 (100 = normal function), the mean function score was 72.8 points after stemmed humeral hemiarthroplasty and 10.57 points higher (2.11 higher to 19.02 higher) after conventional stemmed TSR. There may be no difference in quality of life based on low-quality evidence, downgraded for risk of bias and imprecision. On a scale of 0 to 100 (100 = normal), mean mental quality of life was rated as 57.4 points after stemmed humeral hemiarthroplasty and 1.0 point higher (5.1 lower to 7.1 higher) after conventional stemmed TSR. We are uncertain whether there is any difference in the rate of adverse events or the rate of revision, re-operation, or treatment failure based on very low-quality evidence (downgraded three levels for risk of bias and serious imprecision). The rate of any adverse event following stemmed humeral hemiarthroplasty was 286 per 1000, and following conventional stemmed TSR 143 per 1000, for an absolute difference of 14% fewer events (25% fewer to 21% more). Adverse events included fractures, dislocations, infections, and rotator cuff failure. The rate of revision, re-operation, or treatment failure was 103 per 1000, and following conventional stemmed TSR 77 per 1000, for an absolute difference of 2.6% fewer events (8% fewer to 15% more). Participant-rated global assessment of treatment success was not reported.

AUTHORS' CONCLUSIONS

Although it is an established procedure, no high-quality randomised trials have been conducted to determine whether shoulder replacement might be more effective than other treatments for osteoarthritis or rotator cuff tear arthropathy of the shoulder. We remain uncertain about which type or technique of shoulder replacement surgery is most effective in different situations. When humeral hemiarthroplasty was compared to TSR surgery for osteoarthritis, low-quality evidence led to uncertainty about whether there is a clinically important benefit for patient-reported pain or function and suggested there may be little or no difference in quality of life. Evidence is insufficient to show whether TSR is associated with greater or less risk of harm than humeral hemiarthroplasty. Available randomised studies did not provide sufficient data to reliably inform conclusions about adverse events and harm. Although reverse TSR is now the most commonly performed type of shoulder replacement, we found no studies comparing reverse TSR to any other type of treatment.

Minimum 5-year outcomes of pegged versus keeled all-polyethylene glenoids

Background

Glenoid loosening remains one of the most common concerns at mid- to long-term follow-up after total shoulder arthroplasty (TSA). Pegged and keeled designs have been compared at short-term follow-up, but few studies have compared outcomes at mid-term follow-up. Our purpose was to compare minimum 5-year outcomes of pegged and keeled cemented, all-polyethylene glenoids in TSA. The hypothesis was that no difference in functional outcomes or loosening would be found between the 2 components.

Methods

We performed a multicenter retrospective study of TSAs with either a pegged or keeled cemented glenoid. At a minimum of 5 years postoperatively, functional outcomes and radiographic loosening were compared.

Results

Forty-seven TSAs were available for follow-up, including 20 pegged and 27 keeled components, at a mean of 79 months (range, 60-114 months) postoperatively. Overall, functional outcomes improved in both groups from preoperatively to postoperatively, and no difference was found between the 2 groups. Radiographic glenoid loosening (score ≥ 3) was observed in 9 of 27 keeled glenoids (33.3%) compared with 5 of 20 pegged glenoids (25%) (P = .54). Loosening was associated with lower postoperative forward flexion (P = .026), lower American Shoulder and Elbow Surgeons scores (P = .030), and higher visual analog scale pain scores (P = .007).

Conclusion

Radiographic glenoid loosening of a cemented, all-polyethylene component was associated with decreased functional outcomes at minimum 5-year follow-up of TSAs. However, this study showed no difference in loosening rates between keeled and pegged components.

Glenoid component lucencies are associated with poorer patient-reported outcomes following anatomic shoulder arthroplasty

BACKGROUND

High rates of radiographic glenoid loosening following anatomic total shoulder arthroplasty (TSA) are documented at midterm follow-up. Small studies remain conflicted on the impact of lucent lines on clinical outcomes. This study assesses the impact of radiolucent lines on function and patient-reported outcomes (PROs) following TSA.

METHODS

We retrospectively evaluated 492 primary TSAs performed between February 2005 and April 2016. Radiographs were evaluated for glenoid loosening according to the Lazarus grade at a mean of 5.3 years (range, 2-12 years). Clinical outcome measures included range of motion and American Shoulder and Elbow Surgeons, Constant, University of California-Los Angeles, Simple Shoulder Test, and Shoulder Pain and Disability Index scores. Outcomes were compared between patients with and patients without glenoid lucent lines and in relation to lucency grade.

RESULTS

At most recent follow-up, 308 glenoids (63%) showed no radiolucent lines (group 0) and 184 demonstrated peri-glenoid lucencies (group 1). The groups were similar regarding age, sex, body mass index, comorbidities, and prior surgery. At follow-up, group 1 demonstrated significantly lower improvements in forward elevation (P = .02) and all PROs (P ≤ .005). Subgroup analysis by radiolucency grade showed that forward elevation diminished with increasing radiolucent score and exceeded the minimal clinically important difference (MCID) above grade 2 lucencies. A similar decline in PROs was observed with increasing lucency grade. These differences did not exceed the MCID below grade 5 lucencies.

DISCUSSION

Peri-implant glenoid lucencies following TSA are associated with lower forward elevation and PROs. Lucencies above grade 2 are associated with clinically important losses in overhead motion. However, differences below the MCID are maintained for PROs below grade 5 glenoid lucencies.

A comparison of pegged vs. keeled glenoid components regarding functional and radiographic outcomes in anatomic total shoulder arthroplasty: a systematic review and meta-analysis

Background

The number of total shoulder arthroplasties (TSAs) performed is increasing annually, with a continued effort to improve outcomes using new techniques and materials. In anatomic TSAs, the main options for glenoid fixation currently involve keeled or pegged components. The aim of this review was to determine which fixation option provides optimal long-term functional outcomes with decreased rates of revision surgery and radiolucency.

Methods

The MEDLINE, Embase, PubMed, and Cochrane databases were searched from 2007 to July 10, 2017, for all articles that examined TSAs using either pegged or keeled glenoid fixations. All studies were screened in duplicate for eligibility. Two separate analyses were completed examining noncomparative and comparative studies independently.

Results

A total of 7 comparative studies and 25 noncomparative studies were included in the final analysis. Included in the analysis were 4 randomized (level I) studies, 1 level II study, 8 level III studies, and 19 level IV studies. Meta-analysis of the comparative studies demonstrated a higher rate of revision surgery with keeled fixations compared with pegged fixations (odds ratio, 6.22; 95% confidence interval [CI], 1.38-28.1; P = .02). No significant difference was found with respect to functional outcomes, such as the American Shoulder and Elbow Surgeons score (mean difference, 9.54; 95% CI, –8.25 to 27.34; P = .29) and Constant score (mean difference, 5.31; 95% CI, –12.28 to 22.89; P = .55), as well as radiolucency rates (odds ratio, 1.89; 95% CI, 0.56−6.39; P = .30).

Conclusion

Pegged glenoid fixation may result in a decreased risk of revision TSAs, but no significant differences in patient-reported outcomes have been identified to date.

Does the cement mantle thickness influence the glenoid loosening in anatomic total shoulder arthroplasty? An experimental study

BACKGROUND

Glenoid component loosening is the most frequent failure mode. Few data are available on the effect of thickness of cement on glenoid loosening. The purpose of this study is to determine if the cement mantle thickness influences the mode and localization of loosening. Our hypotheses are: 1) failure is caused by traction stresses generated within the cement mantle and 2) a thicker cement mantle amplifies the rocking horse effect.

METHODS

Using bone substitute, an experimental protocol was designed to compare loosening of a keeled glenoid prosthesis in axial traction and off-centered-load, to recreate the rocking-horse effect (1.000.000 cycles). Different standardized mantle of cement between the back of the glenoid and the foam were tested (0-1 - 2-3 mm). The displacement of the polyethylene was assessed with an LVDT (Linear Variable Differential Transformer) gauge when the prosthetic humeral head loaded the opposite part of the implant.

RESULTS

The loosening took place within the keel of the implant, and at the polyethylene-cement interface in traction if there was cement at the back of the polyethylene. For cycling loading, we observed a loosening at this interface, with associated fracture of the cement, only for cement 2 and 3 mm thick.

CONCLUSION

This experimental study suggests that the cement mantle should be as thin as possible between the back of the implant and the sub-chondral bone but should be optimized around the keel of the implant.

LEVEL OF EVIDENCE

Basic Science Study.

Polyethylene glenoid component fixation geometry influences stability in total shoulder arthroplasty

Glenoid component stability is essential to ensure successful long-term survivability following total shoulder arthroplasty. As such, this computational study assessed the stability of five all-polyethylene glenoid components (Keel, Central-Finned 4-Peg, Peripheral 4-Peg, Cross-Keel, and Inverted-Y), using simulated joint loading in an osteoarthritic patient cohort. Stability was assessed on the basis of component micromotion in the tangential and normal directions. Maximum tangential micromotion occurred in the Cross-Keel (146 ± 46 µm), which was significantly greater (p < .001) than the other components. Maximum normal micromotion occurred in the Inverted-Y (109 ± 43 µm), which was significantly greater (p ≤ .002) than the other four components. In general, the Central-Finned 4-Peg exhibited the least normal and tangential micromotion, while the keeled components shown the highest normal and tangential micromotion. This study suggests that modifications to keeled designs do not improve component stability under the conditions tested, and pegged components show superior computational stability.

Model-based RSA is suitable for clinical trials on the glenoid component of reverse total shoulder arthroplasty

This study aims to validate model-based radiostereometric analysis (RSA) on the glenoid component of reversed total shoulder arthroplasty. We compared two different modalities of model-based RSA, elementary geometrical shapes and reversed engineering. We also explored two different ways to position the patient to obtain different projections of the implant, the hip-position (transversal) and shoulder-position (sagittal). Phantom accuracy was determined by performing nine translations (x, y, z) and five rotations (x, y, z), and expressed as the mean difference between RSA measurements and micrometer values. Precision was measured using 12 double examinations of the phantom and 19 in patients, and expressed as1.96 × standard deviations of the paired differences between double examinations. The accuracy was high for both modalities, but rotation around the symmetrical axis of the implant could not be measured using reversed engineering. Clinical precision ranged from 0.13 to 0.25 mm for translations, and 0.4° to 0.7° for rotations, using reversed engineering. For elementary geometrical shapes, the precision ranged from 0.18 to 0.34 mm for translations, and 0.8° to 1.8° for rotations. The hip-position was abandoned due to poor implant visualization. Model-based RSA on the glenoid component of reversed total shoulder arthroplasty has a high precision and accuracy, comparable to RSA results on hips and knees. Patient positioning is vital for obtaining adequate results. We found that reversed engineering was the more reliable method, and recommend reversed engineering as the method of choice for further clinical RSA investigation of the glenoid component of reversed total shoulder arthroplasty. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3299-3307, 2018.

Sequential 3-dimensional computed tomography analysis of implant position following total shoulder arthroplasty

BACKGROUND

Detection of postoperative component position and implant shift following total shoulder arthroplasty (TSA) can be challenging using routine imaging. The purpose of this study was to evaluate glenoid component position over time using 3-dimensional computed tomography (CT) analysis with minimum 2-year follow-up.

METHODS

Twenty patients underwent primary TSA with sequential CT scanning of the shoulder: a preoperative study, an immediate postoperative study within 2 weeks of surgery, and a postoperative study performed at minimum 2-year follow-up (CT3). Postoperative glenoid component position and central peg osteolysis were assessed across the immediate postoperative CT scan and CT3. Glenoids with evidence of component shift and/or grade 1 central peg osteolysis on CT3 were considered at risk of loosening.

RESULTS

Of the patients, 7 (35%) showed evidence of glenoid components at risk of loosening on CT3, 6 with component shift (3 with increased inclination alone, 1 with increased retroversion alone, and 2 with both increased inclination and retroversion). Significantly more patients with glenoid component shift had grade 1 central peg osteolysis on CT3 compared with those without shift (83% vs 7%, P = .002). One clinical failure occurred, with the patient undergoing revision to reverse TSA for rotator cuff deficiency.

CONCLUSIONS

Three-dimensional CT imaging analysis following TSA identified changes in glenoid component position over time, with inclination being the most common direction of shift and grade 1 central peg osteolysis commonly associated with shift. These findings raise concern for glenoids at risk of loosening, but further follow-up is needed to determine the long-term clinical impact of these findings.

Anatomic Total Shoulder Arthroplasty Using a Self-Pressurizing Pegged Bone-Preserving Cemented Glenoid Component: A 2- to 5-Year Follow-up Study

Background:

High rates of radiographic loosening have been reported with various glenoid designs. Many available designs sacrifice most of the bone at the central portion of the glenoid vault, creating large areas of deficiency when revision becomes necessary. The purpose of this study was to report the 2- to 5-year outcome of shoulder arthroplasty using a bone-preserving all-polyethylene glenoid components with self-pressurizing pegs.

Methods:

Between August 2011 and December 2014, 202 consecutive anatomic total shoulder arthroplasties (TSAs) were performed by a single surgeon with implantation of a self-pressurizing cemented pegged glenoid component in 190 patients (12 patients had both shoulders replaced). Patients were followed up prospectively and evaluated for pain, motion, strength, American Shoulder and Elbow Surgeons (ASES) scores, and radiographic changes. The mean follow-up time was 2.7 (2–5) years.

Results:

TSA improved pain and function reliably. At the most recent follow-up, 94% of the shoulders had no or mild pain. Motion included 154 ± 25° of elevation, 68 ± 18° of external rotation, and median internal rotation to T10 (range, iliac crest to T4). The most recent average ASES score was 82 ± 15 points. Early postoperative radiographs showed no radiolucent lines. No humeral or glenoid component was considered radiographically loose at the most recent follow-up. Complications requiring reoperation included subscapularis insufficiency (4), posterior instability (2), deep infection (1), stiffness (1), and a painful loose body (1). No components were revised for loosening.

Conclusions:

Anatomic TSA using a cemented bone-preserving all-polyethylene pegged self-pressurizing glenoid component provided satisfactory clinical outcomes and survival at 2 to 5 years.

Radiographic and clinical comparison of pegged and keeled glenoid components using modern cementing techniques: midterm results of a prospective randomized study

BACKGROUND

Glenoid component loosening remains a significant issue after anatomic shoulder arthroplasty. Pegged glenoid components have shown better lucency rates than keeled components in the short term; however, midterm to long-term results have not fully been determined. We previously reported early outcomes of the current randomized controlled group of patients, with higher glenoid lucency rates in those with a keeled glenoid. The purpose of this study was to evaluate the radiographic and clinical outcomes of these components at minimum 5-year follow-up.

METHODS

Fifty-nine total shoulder arthroplasties were performed in patients with primary glenohumeral osteoarthritis. Patients were randomized to receive either a pegged or keeled glenoid component. Three raters graded radiographic glenoid lucencies. Clinical outcome scores and active mobility outcomes were collected preoperatively and at yearly postoperative appointments.

RESULTS

Of the 46 shoulders meeting the inclusion criteria, 38 (82.6%) were available for minimum 5-year radiographic follow-up. After an average of 7.9 years, radiographic lucency was present in 100% of pegged and 91% of keeled components (P = .617). Grade 4 or 5 lucency was present in 44% of pegged and 36% of keeled components (P = .743). There were no differences in clinical outcome scores or active mobility outcomes between shoulders with pegged and keeled components at last follow-up. Within the initial cohort, 20% of the keeled shoulders (6 of 30) and 7% of the pegged shoulders (2 of 29) underwent revision surgery (P = .263). Kaplan-Meier analysis showed no significant difference in survival rates between groups (P = .560).

CONCLUSION

At an average 7.9-year follow-up, non-ingrowth, all-polyethylene pegged glenoid implants are equivalent to keeled implants with respect to radiolucency, clinical outcomes, and need for revision surgery.

Evaluation of thirty eight cemented pegged glenoid components with variable backside curvature: two-year minimum follow-up

BACKGROUND

The PERFORM™ pegged glenoid system has been used for shoulder arthroplasty since 2012. This system offers multiple backside curvatures per size to better match variable patient anatomy. As a result, less reaming is required and subchondral bone is preserved-a critical factor in preventing glenoid migration and loosening, thus enhancing implant longevity.

PURPOSE

The purpose of this study was to analyze all radiographic modifications around this new glenoid implant.

METHOD

Thirty-eight shoulders which received the PERFORM™ pegged glenoid component between June 2012 and January 2014 for primary or secondary osteoarthritis were reviewed at two-years minimum follow-up. There were 13 men and 22 women with an average age of 67 years. Humeral components were an uncemented short stem implant in nine (23%) and a resurfacing implant in 29 (77%).

RESULTS

At 27-months average follow-up (24-41), Constant score improved from 30 to 65 points. Range of motion improved significantly at follow-up from 100° to 142° for the anterior elevation, and from 15 to 40° for the external rotation. Radiographic lucent lines (RLL) were observed post-operatively in eight cases (21%), and in 16 cases (42%) at the last follow-up with an increase of the RLL score from 0.36 ± 0.8 to 1.3 ± 2 (p < 0.001) without signs of loosening (RLL > 12). One revision has been performed after anterior shoulder dislocation, rotator cuff tear and glenoid component migration. RLL score was not correlated with dominant side, sex, age, or Constant score.

DISCUSSION-CONCLUSION

The cemented pegged glenoid component with multiple backside curvatures gave satisfactory results at two-years minimum follow-up for up to three years with a low RLL score. Long-term studies are mandatory to confirm these results.

Survival of the pegged glenoid component in shoulder arthroplasty: part II

BACKGROUND

Loosening of the glenoid component is a primary reason for failure of an anatomic shoulder arthroplasty. Pegged glenoids were designed in an effort to outperform keeled components. This study evaluated the midterm clinical and radiographic survival of a single implant design with implantation of an in-line pegged glenoid component and identified risk factors for radiographic loosening and clinical failure.

MATERIALS AND METHODS

There were 330 total shoulder arthroplasties that had been implanted with a cemented, all-polyethylene, in-line pegged glenoid component evaluated with an average clinical follow-up of 7.2 years. Of these shoulders, 287 had presurgical, initial postsurgical, and late postsurgical radiographs (mean radiographic follow-up, 7.0 years).

RESULTS

At most recent follow-up, 30 glenoid components had been revised for aseptic loosening. This translated to a rate of glenoid component survival free from revision for all 330 shoulders of 99% at 5 years and 83% at 10 years. Of 287 glenoid components, 120 were considered loose on the basis of radiographic evaluation. Four humeral components were considered loose. Component survival (Kaplan-Meier) free from radiographic failure at 5 and 10 years was 92% and 43%. Severe presurgical glenoid erosion (Walch A2, B2, C) and patient age <65 years were risk factors for radiographic failure. Late humeral head subluxation was associated with radiographic failure.

CONCLUSION

Despite the predominant thinking that pegged glenoid components may be superior to keeled designs, midterm radiographic and clinical failure rates were high with this pegged component design, particularly after 5 years. Advanced presurgical glenoid erosion and younger patient age are risk factors for radiographic loosening. Revision rates underestimate radiographic glenoid loosening.

Radiostereometric analysis of keeled versus pegged glenoid components in total shoulder arthroplasty: a randomized feasibility study

BACKGROUND

This study aimed to assess differences in the fixation and functional outcomes between pegged and keeled all-polyethylene glenoid components for standard total shoulder arthroplasty.

METHODS

Patients were randomized to receive a keeled or pegged all-polyethylene glenoid component. We used model-based radiostereometric analysis (RSA) to assess glenoid fixation and subjective outcome measures to assess patient function. Follow-up examinations were completed at 6 weeks and 6, 12 and 24 months after surgery. Modifications to the RSA surgical, imaging and analytical techniques were required throughout the study to improve the viability of the data.

RESULTS

Stymied enrolment resulted in only 16 patients being included in our analyses. The RSA data indicated statistically greater coronal plane migration in the keeled glenoid group than in the pegged group at 12 and 24 months. Functional outcome scores did not differ significantly between the groups at any follow-up. One patient with a keeled glenoid showed high component migration after 24 months and subsequently required revision surgery 7 years postoperatively.

CONCLUSION

Despite a small sample size, we found significant differences in migration between glenoid device designs. Although clinically these findings are not robust, we have shown the feasibility of RSA in total shoulder arthroplasty as well as the value of a high-precision metric to achieve objective results in a small group of patients.

Treatment of the Fixation Surface Improves Glenoid Prosthesis Longevity in vitro

Many commercial cemented glenoid components claim superior fixation designs and increased survivability. However, both research and clinical studies have shown conflicting results and it is unclear whether these design variations do improve loosening rates. Part of the difficulty in investigating fixation failure is the inability to directly observe the fixation interface, a problem addressed in this study by using a novel experimental set-up. Cyclic loading-displacement tests were carried out on 60 custom-made glenoid prostheses implanted into a bone substitute. Design parameters investigated included treatment of the fixation surface of the component resulting in different levels of back-surface roughness, flat-back versus curved-back, keel versus peg and more versus less conforming implants. Visually-observed failure and ASTM-recommended rim-displacements were recorded throughout testing to investigate fixation failure and if rim displacement is an appropriate measure of loosening. Roughening the implant back (R_a>3µm) improved resistance to failure (P<0.005) by an order of magnitude with the rough and smooth groups failing at 8712±5584 cycles (mean±SD) and 1080±1197 cycles, respectively. All other design parameters had no statistically significant effect on the number of cycles to failure. All implants failed inferiorly and 95% (57/60) at the implant/cement interface. Rim-displacement correlated with visually observed failure. The most important effect was that of roughening the implant, which strengthened the polyethylene-cement interface. Rim-displacement can be used as an indicator of fixation failure, but the sensitivity was insufficient to capture subtle effects.

LEVEL OF EVIDENCE

Basic Science Study, Biomechanical Analysis.

The accuracy and precision of radiostereometric analysis in upper limb arthroplasty

Background and purpose - Radiostereometric analysis (RSA) is an accurate method for measurement of early migration of implants. Since a relation has been shown between early migration and future loosening of total knee and hip prostheses, RSA plays an important role in the development and evaluation of prostheses. However, there have been few RSA studies of the upper limb, and the value of RSA of the upper limb is not yet clear. We therefore performed a systematic review to investigate the accuracy and precision of RSA of the upper limb. Patients and methods - PRISMA guidelines were followed and the protocol for this review was published online at PROSPERO under registration number CRD42016042014. A systematic search of the literature was performed in the databases Embase, Medline, Cochrane, Web of Science, Scopus, Cinahl, and Google Scholar on April 25, 2015 based on the keywords radiostereometric analysis, shoulder prosthesis, elbow prosthesis, wrist prosthesis, trapeziometacarpal joint prosthesis, humerus, ulna, radius, carpus. Articles concerning RSA for the analysis of early migration of prostheses of the upper limb were included. Quality assessment was performed using the MINORS score, Downs and Black checklist, and the ISO RSA Results - 23 studies were included. Precision values were in the 0.06-0.88 mm and 0.05-10.7° range for the shoulder, the 0.05-0.34 mm and 0.16-0.76° range for the elbow, and the 0.16-1.83 mm and 11-124° range for the TMC joint. Accuracy data from marker- and model-based RSA were not reported in the studies included. Interpretation - RSA is a highly precise method for measurement of early migration of orthopedic implants in the upper limb. However, the precision of rotation measurement is poor in some components. Challenges with RSA in the upper limb include the symmetrical shape of prostheses and the limited size of surrounding bone, leading to over-projection of the markers by the prosthesis. We recommend higher adherence to RSA guidelines and encourage investigators to publish long-term follow-up RSA studies.

Is there sufficient evidence to support intervention to manage shoulder arthritis?

BACKGROUND

We explore the nature, extent and validity of research studies concerning the management of shoulder arthritis to identify whether current management recommendations are adequate.

METHODS

A full electronic search for relevant studies published between 2002 and 2012 was performed. The search focused on level 1 and level 2 studies. Full texts of selected articles were retrieved and assessed for quality against validated criteria.

RESULTS

Four hundred and eleven studies were identified on the initial search and screened. Sixteen studies were selected for inclusion in the review. The studies identified were unable to provide a clear indication of best intervention for shoulder arthritis. The inclusion of a range of shoulder pathologies in some studies and the diversity in outcome measures used made it difficult for systematic reviews to effectively pool data. Better outcomes have been shown with total shoulder replacement over hemiarthroplasty for shoulder osteoarthritis; however, primary studies were often of limited quality. Sparse evidence is available for all other interventions, regardless of whether operative or non-operative.

CONCLUSIONS

The present review highlights the need for standardization of outcome assessment following treatment of shoulder arthritis. More rigorous and robust primary studies are needed to guide clinical practice on the best interventions for arthritis of the shoulder.

Radiostereometric and Radiographic Analysis of Glenoid Component Motion After Total Shoulder Arthroplasty

Aseptic glenoid component loosening is a common cause of total shoulder arthroplasty (TSA) failure, but early detection is difficult because pain often appears late and radiolucent lines are of uncertain significance. This study sought to answer the following questions: (1) What types of glenoid component motion may be observed during the first 3 years following implantation?; (2) Is the appearance of radiolucent lines around the glenoid component a reliable indicator of component motion?; and (3) Are clinical outcomes correlated with early glenoid component motion within the first 3 years after TSA? Eleven patients (mean age, 60.6 years) underwent TSA using a cemented, all-polyethylene glenoid component with tantalum bead implantation. Clinical outcomes (American Shoulder and Elbow Surgeons [ASES] score, visual analog scale [VAS] pain score, and range of motion) were compared pre- and postoperatively, and radiolucencies were graded according to the criteria of Lazarus et al. Patients were evaluated using radiostereometric analysis at 6 months and 1, 2, and 3 years postoperatively to measure component micromotion in translation and rotation. At a mean follow-up of 50.2 months, mean ASES score had improved from 30.3 to 81.3 (P<.001), mean VAS pain score had improved from 8 to 1 (P<.001), active forward flexion had improved from 109° to 155° (P=.001), active external rotation had improved from 28° to 54° (P=.003), and internal rotation had improved from the level of the sacrum to L3 (P=.002). Radiolucencies were detected around none of the components at 1 year, 6 components at 2 years, and 5 components at 3 years, and these radiolucencies were mostly found around components that experienced high levels of rotational motion.

An in vitro study comparing limited to full cementation of polyethylene glenoid components

Background

Glenoid component survival is critical to good long-term outcomes in total shoulder arthroplasty. Optimizing the fixation environment is paramount. The purpose of this study was to compare two glenoid cementing techniques for fixation in total shoulder arthroplasty.

Methods

Sixteen cadaveric specimens were randomized to receive peg-only cementation (CPEG) or full back-side cementation (CBACK). Physiological cyclic loading was performed and implant displacement was recorded using an optical tracking system. The cement mantle was examined with micro-computed tomography before and after cyclic loading.

Results

Significantly greater implant displacement away from the inferior portion of the glenoid was observed in the peg cementation group when compared to the fully cemented group during the physiological loading. The displacement was greatest at the beginning of the loading protocol and persisted at a diminished rate during the remainder of the loading protocol. Micro-CT scanning demonstrated that the cement mantle remained intact in both groups and that three specimens in the CBACK group demonstrated microfracturing in one area only.

Discussion

Displacement of the CPEG implants away from the inferior subchondral bone may represent a suboptimal condition for long-term implant survival. Cement around the back of the implant is suggested to improve initial stability of all polyethylene glenoid implants.

Clinical relevance

Full cementation provides greater implant stability when compared to limited cementation techniques for insertion of glenoid implants. Loading characteristics are more favorable when cement is placed along the entire back of the implant contacting the subchondral bone.

Metal-Backed Glenoid Components Have a Higher Rate of Failure and Fail by Different Modes in Comparison with All-Polyethylene Components: A Systematic Review

BACKGROUND

Glenoid component failure is a common and serious complication of total shoulder arthroplasty. The purpose of this study was to evaluate published evidence on whether metal backing lessens the rate of glenoid component failure.

METHODS

A comprehensive systematic review yielded twenty-one studies on radiolucency, radiographic failure, and revision after arthroplasty with metal-backed glenoid components and twenty-three studies with all-polyethylene components. Our analysis included data on 1571 metal-backed and 3035 all-polyethylene components. The mean duration of follow-up was 5.8 years in the studies with metal-backed components and 7.3 years with all-polyethylene components.

RESULTS

All-polyethylene components had a 42.5% rate of radiolucency compared with 34.9% for metal-backed components (p = 0.0026) and a 21.1% rate of radiographic loosening or failure compared with 16.8% for metal-backed components (p = 0.0005). However, the rate of revision was more than three times higher with metal-backed components (14.0%) than with all-polyethylene components (3.8%, p < 0.0001). Although 77% of the revisions of all-polyethylene components were for loosening, 62% of the revisions of metal-backed components were for other reasons, such as component fracture, screw breakage, component dissociation, polyethylene wear, metal wear, and rotator cuff tear (p < 0.0001).

CONCLUSIONS

The published evidence indicates that metal-backed glenoid components require revision at a significantly higher rate and for different reasons in comparison with all-polyethylene components.

LEVEL OF EVIDENCE

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

Incidence of early radiolucent lines after glenoid component insertion for total shoulder arthroplasty: a radiographic study comparing pressurized and unpressurized cementing techniques

BACKGROUND

Total shoulder arthroplasty (TSA) is commonly performed for arthritic conditions of the shoulder. The outcome after TSA is generally good, but there are several modes of failure, with one of the more common reasons being glenoid loosening. One possible cause for glenoid loosening is inadequate cementation technique. The purpose of this study was to evaluate the incidence of lucent lines on the first postoperative radiograph using 2 different cementation techniques.

MATERIALS AND METHODS

One hundred consecutive patients had a pegged glenoid placed with 1 of 2 different cementation techniques. In 26 consecutive patients, the pegged glenoid component was cemented with a traditional minimal manual pressurization technique, whereas 74 underwent a contemporary 3-step pressurization cementation technique before implant insertion. The first postoperative radiograph was evaluated using the system of Lazarus et al, looking at the frequency of lucent lines. The radiographs were deidentified and were randomized and evaluated by 2 independent observers on 3 separate occasions.

RESULTS

The Kruskal-Wallis test showed significant differences between grades of radiolucent lines for pressurized versus unpressurized cementation techniques. There were significantly (P < .05) fewer lucent lines identified in the group that underwent contemporary 3-step pressurization as opposed to the group that underwent minimal manual pressurization. Intraobserver reliability and interobserver reliability with Cronbach α coefficients were good.

CONCLUSION

The 3-step pressurized cementation technique resulted in a low incidence of radiolucent lines around the glenoid implant in patients undergoing TSA.

LEVEL OF EVIDENCE

Level II, Prospective Cohort, Treatment Study.

Rates of radiolucency and loosening after total shoulder arthroplasty with pegged or keeled glenoid components

BACKGROUND

The objective of this study was to conduct a meta-analysis and cost-effectiveness analysis of the effect of glenoid design on radiolucency, loosening, and revision after total shoulder arthroplasty.

METHODS

We conducted a systematic review of PubMed, MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and CINAHL with use of a search for the terms arthroplasty AND shoulder AND (peg OR keel). Data on study design and on the end points of radiolucency, loosening, and revision were extracted independently and in duplicate. Random-effect models were used to calculate the pooled risk ratio and risk difference. The risk difference was used to estimate the number needed to treat (the number of individuals who would have to receive a pegged component to avoid one loosening or revision).

RESULTS

Eight studies with a total of 1460 patients (mean age, sixty-seven years) were included. The mean study quality was 1.75 points (95% confidence interval [CI], 1.26 to 2.24) on the 3-point modified Jadad scale. There was no significant difference in the risk of any radiolucency (risk ratio, 0.42; 95% CI, 0.12 to 1.42) or in the risk of severe radiolucency (risk ratio, 0.65; 95% CI, 0.23 to 1.82) between pegged and keeled components. The pooled risk ratio for revision was 0.27 (95% CI, 0.08 to 0.88) in favor of pegged components (p = 0.028). At a cost-effectiveness threshold of $50,000 per quality-adjusted life year, pegged components can be between $2325 and $40,920 more expensive than keeled components and still be cost-effective.

CONCLUSIONS

Our study produced evidence that pegged glenoid components were associated with a lower revision risk compared with keeled components. However, the difference was rather small and will therefore be most meaningful to high-volume shoulder arthroplasty centers. Because of the similarity between primary and secondary costs, pegged glenoid designs were more cost-effective than keeled glenoid designs.

Pain and function in eight hundred and fifty nine patients comparing shoulder hemiprostheses, resurfacing prostheses, reversed total and conventional total prostheses

PURPOSE

Functional results of reversed total prostheses (RTP) have-to a very limited degree-been compared with those of other shoulder prosthesis types. The aim of our study was to compare results of four different types of shoulder prostheses in terms of function, pain, and quality of life (QoL).

METHODS

Questionnaires were completed by 859 patients with shoulder prostheses registered in the Norwegian Arthroplasty Register. Patients with osteoarthritis (OA), rheumatoid arthritis (RA), or fracture sequela (FS) were included. Symptoms and function were assessed using the Oxford Shoulder Score (OSS, scale 0-48), and the EuroQoL-5D (EQ-5D) was used to assess QoL.

RESULTS

Best functional results were obtained using conventional total prostheses (TPs) and RTPs -mean OSS improvement 18 and 16 units, respectively, vs 11 with hemiprostheses (HPs). For patients with OA, TPs performed best; for those with RA and FS, RTPs performed best; and those with HPs had the worst results in all diagnostic groups. The greatest improvement in QoL was seen in patients with TPs and RTPs.

CONCLUSIONS

Conventional TPs provide the best improvement in pain, function and QoL in OA patients; RTPs are superior in patients with RA and FS.

Good function after shoulder arthroplasty

BACKGROUND AND PURPOSE

Different results after shoulder arthroplasty have been found for different diagnostic groups. We evaluated function, pain, and quality of life after shoulder arthroplasty in 4 diagnostic groups.

PATIENTS AND METHODS

Patients with shoulder arthroplasties registered in the Norwegian Arthroplasty Register from 1994 through 2008 were posted a questionnaire in 2010. 1,107 patients with rheumatoid arthritis (RA), osteoarthritis (OA), acute fracture (AF), or fracture sequela (FS) returned completed forms (65% response rate). The primary outcome measure was the Oxford shoulder score (OSS), which assesses symptoms and function experienced by the patient on a scale from 0 to 48. A secondary outcome measure was the EQ-5D, which assesses life quality. The patients completed a questionnaire concerning symptoms 1 month before surgery, and another concerning the month before they received the questionnaire.

RESULTS

Patients with RA and OA had the best results with a mean improvement in OSS of 16 units, as opposed to 11 for FS patients. Both shoulder pain and function had improved substantially. The change in OSS for patients with AF was negative (-11), but similar end results were obtained for AF patients as for RA and OA patients. Quality of life had improved in patients with RA, OA, and FS.

INTERPRETATION

Good results in terms of pain relief and improved level of function were obtained after shoulder arthroplasty for patients with RA, OA, and-to a lesser degree-FS. A shoulder arthropathy had a major effect on quality of life, and treatment with shoulder replacement substantially improved it.

Total shoulder arthroplasty with an all-polyethylene pegged bone-ingrowth glenoid component: a clinical and radiographic outcome study

BACKGROUND

Loosening of the glenoid component continues to be the foremost cause of medium and long-term failure of shoulder replacements. The purpose of this study was to evaluate the clinical and radiographic results of a minimally cemented all-polyethylene pegged glenoid component designed for biologic fixation.

METHODS

Forty-four shoulders in forty-one patients with a mean age of sixty-six years underwent total shoulder arthroplasty with a pegged bone-ingrowth glenoid component. Outcome data included the American Shoulder and Elbow Surgeons questionnaire, the Simple Shoulder Test, and visual analog scales. A detailed radiographic analysis was performed by two board-certified musculoskeletal radiologists who were blinded to clinical and patient-reported outcomes. The radiographs were evaluated with regard to the presence of radiolucent lines at the bone-cement interface, implant seating, and the radiodensity between the flanges of the central peg.

RESULTS

The mean duration of clinical follow-up was four years and the mean duration of radiographic follow-up was three years. Twenty shoulders had perfect seating and radiolucency grades, thirty had increased radiodensity between the flanges of the central peg, and three demonstrated osteolysis. Radiodensity about the uncemented central peg at the time of the latest follow-up was positively associated with perfect seating and radiolucency grades on the initial postoperative radiographs (p = 0.03, Fisher exact test). The Simple Shoulder Test score, the American Shoulder and Elbow Surgeons score, and all visual analog scale scores had improved significantly (p < 0.01) at the time of the latest follow-up.

CONCLUSIONS

Total shoulder arthroplasty with a minimally cemented, all-polyethylene, pegged glenoid implant can yield stable and durable fixation at short to medium-term follow-up (mean, four years).

Surgery for Shoulder Osteoarthritis: A Cochrane Systematic Review

Objective.

To determine the benefits and harm of surgery for shoulder osteoarthritis (OA).

Methods.

We performed a Cochrane Systematic Review of clinical trials of adults with shoulder OA, comparing surgical techniques [total shoulder arthroplasty (TSA), hemiarthroplasty, implant types, and fixation] to placebo, sham surgery, nonsurgical modalities, and no treatment. We also reviewed trials that compared various surgical techniques, reporting patient-reported outcomes (pain, function, quality of life, etc.) or revision rates. We calculated the risk ratio for categorical outcomes and mean differences for continuous outcomes with 95% CI.

Results.

There were no controlled trials of surgery versus placebo or nonsurgical interventions. Seven studies with 238 patients were included. Two studies compared TSA to hemiarthroplasty (n = 88). Significantly worse scores on the 0–100 American Shoulder and Elbow Surgeons scale (mean difference, −10.05 at 24–34 mo; 95% CI −18.97 to −1.13; p = 0.03) and a nonsignificant trend toward higher revision rate in hemiarthroplasty compared to TSA (relative risk 6.18; 95% CI 0.77 to 49.52; p = 0.09) were noted. With 1 study providing data (n = 41), no differences were noted between groups for pain scores (mean difference 7.8; 95% CI −5.33 to 20.93), quality of life on Medical Outcomes Study Short-Form 36 physical component summary (mean difference 0.80; 95% CI −6.63 to −8.23), and adverse events (relative risk 1.2; 95% CI 0.4 to 3.8).

Conclusion.

TSA was associated with better shoulder function, with no other demonstrable clinical benefits compared to hemiarthroplasty. More studies are needed to compare clinical outcomes between them and comparing shoulder surgery to sham, placebo, and other nonsurgical treatment options.

Surgery for shoulder osteoarthritis

BACKGROUND

Surgical treatment including shoulder arthroplasty is a treatment option for patients with advanced osteoarthritis of the shoulder who have failed conservative treatment.

OBJECTIVES

To determine the benefit and harm of surgery in patients with osteoarthritis of the shoulder confirmed on X-ray who do not respond to analgesics and NSAIDs.

SEARCH STRATEGY

We searched: The Cochrane Central Register of Controlled Trials (CENTRAL), via The Cochrane Library; OVID MEDLINE; CINAHL (via EBSCOHost); OVID SPORTdiscus; EMBASE; and Science Citation Index (Web of Science).

SELECTION CRITERIA

All randomized clinical trials (RCTs) or quasi-randomized trials including adults with osteoarthritis of the shoulder joint (PICO- patients) comparing surgical techniques (total shoulder arthroplasty, hemiarthroplasty, implant types and fixation- intervention) versus placebo or sham surgery, non-surgical modalities, no treatment, or comparison of one type of surgical technique to another (comparison) with patient-reported outcomes (pain, function, quality of life etc.) or revision rates (outcomes).

DATA COLLECTION AND ANALYSIS

We reviewed titles and abstracts for inclusion, extracted study and outcomes data and assessed the risk of bias of included studies. For categorical outcomes, we calculated the risk ratio (with 95% confidence interval (CI)) and for continuous outcomes, the mean difference (95% CI).

MAIN RESULTS

Seven studies (238 patients) were included for analyses. None of the studies compared shoulder surgery to sham surgery, non-surgical modalities or placebo. Two studies compared hemiarthroplasty to total shoulder arthroplasty; three compared keeled and pegged humeral components; and one each compared navigation surgery to conventional and all-polyethylene to metal-backed implant. Two studies (88 patients) compared hemiarthroplasty to total shoulder arthroplasty. Patients who underwent hemiarthroplasty had statistically significantly worse functional scores on American Shoulder and Elbow Surgeons Shoulder Scale (100 point scale; higher = better) at 24 to 34 month follow-up compared to those who underwent total shoulder arthroplasty (mean difference, -10.05; 95% CI, -18.97 to -1.13; 2 studies, 88 patients), but no statistically significant differences between hemiarthroplasty and TSA were noted for pain scores (mean difference, 7.8; 95% CI, -5.33 to 20.93; 1 study, 41 patients), quality of life on short-form 36 physical component summary (mean difference, 0.80; 95% CI, -6.63 to 8.23; 1 study, 41 patients) and adverse events (Risk ratio, 1.19; 95% CI, 0.37 to 3.81; 1 study, 41 patients), respectively. A non-statistically significant trend towards higher revision rate in hemiarthroplasty compared to total shoulder arthroplasty was noted (Risk ratio, 6.18; 95% CI, 0.77 to 49.52; 2 studies, 88 patients; P = 0.09).

AUTHORS' CONCLUSIONS

Total shoulder arthroplasty seems to offer an advantage in terms of shoulder function, with no other clinical benefits over hemiarthroplasty. More studies are needed to compare clinical outcomes of surgery using different components and techniques in patients with osteoarthritis of the shoulder. There is a need for studies comparing shoulder surgery to sham, placebo and other non-surgical treatment options.