Glenoid failure remains the most common mode of total shoulder arthroplasty failures. Porous tantalum metal (Trabecular Metal™, Zimmer) have grown in popularity in hip and knee arthroplasty. First-generation porous tantalum metal-backed glenoid components demonstrated metal debris, resulted in failure, and were revised to second-generation glenoid implants. Evidence for second-generation porous tantalum metal implants in shoulder arthroplasty is sparse.1–4 The purpose of this study was to assess clinical and radiographic outcomes in a series of patients with second-generation porous tantalum glenoid components at a minimum two-years postoperative. We retrospectively reviewed the clinical and radiographic outcomes of patients who received a second-generation porous tantalum glenoid component anatomic shoulder arthroplasty between May 2009 and December 2017 with minimum 24 months follow-up. The shoulder arthroplasties were performed by one of two senior fellowship-trained surgeons. We collected postoperative clinical outcome indicators: EQ5D visual analog scale (VAS), Western Ontario Osteoarthritis of the Shoulder (WOOS) Index, American Shoulder and Elbow Surgeons (ASES) Score, and Constant Score (CS). Radiographic review was performed by an independent fellowship-trained surgeon. The Endrizzi metal debris grading system1 was utilized to grade metal debris. We computed descriptive statistics and compared outcome scores between groups via the non-parametric Wilcoxon rank-sum test, with group-wise comparisons defined by: metal debris and humeral head migration (secondary analyses). Thirty-five patients [23 male (65.7%) and 12 female (34.3%)] with 40 shoulder replacements participated in the study. Forty of 61 shoulders (65.6%) had an average of 64 ± 20.3 months follow-up (range 31 to 95). Average BMI was 27.5 ± 4.4 kg/m2 (range 19.5 to 39.1). The average postoperative EQ5D VAS at final follow-up was 74.6 ± 22.5, WOOS Index 87.9 ± 16.6, ASES Score 88.3 ± 10.9, and CS 80.4 ± 13. At final follow-up, 18 of 40 shoulders (45%) had metal debris [15 of 40 (37.5%) Endrizzi grade 1 and three of 40 (7.5%) Endrizzi grade 2], and 22 of 40 shoulders (55%) did not show evidence of metal debris. There was one non-revision reoperation (open subscapularis exploration), one shoulder with anterosuperior escape, three shoulders with glenoid radiolucencies indicative of possible glenoid loosening, and nine shoulders with superior migration of the humeral head (>2mm migration at final follow-up compared to immediate postoperative). When comparing postoperative scores between patients with vs without metal debris, we found no statistically significant difference in the EQ5D VAS, WOOS Index, ASES Score and CS. On further analyses, when comparing superior migration of the humeral head and postoperative outcomes scores, we found no statistically significant difference. We report the longest published follow-up with clinical and radiographic outcomes of second-generation porous tantalum glenoid anatomic shoulder arthroplasties. In this series of patients, 45% of total shoulder arthroplasties with a second-generation porous tantalum glenoid implant had radiographic evidence of metal debris. This metal debris was not statistically associated with poorer postoperative outcomes. Further investigation and ongoing follow-up are warranted

Total shoulder arthroplasty (TSA) is an excellent surgical solution for patients with shoulder arthritis, providing good to excellent results in the vast majority of patients. Complications are rare, however, when they occur, can be devastating for both the patient and surgeon. An increasingly recognised complication of TSA is glenoid component failure. In a recent review of nearly 4000 shoulder arthroplasties, symptomatic glenoid component loosening occurs at a rate of 1.2% per year, while asymptomatic radiolucent lines occur at a rate of 7.3% per year. In addition, keeled glenoid components have been found to have an increased incidence of radiolucent lines compared to pegged glenoid components at both short and longer-term follow-up. Further, pegged glenoid components are associated with a lower risk of revision arthroplasty compared to keeled glenoid components. In a separate study of approximately 4600 shoulder arthroplasties, metal-backed glenoid components were found to have significantly lower rates of radiolucent lines, radiographic loosening, and component failure compared to all-polyethylene glenoid components. Despite these findings, however, metal-backed components are significantly more likely to require revision surgery (3:1) compared to all-polyethylene components. For the failed TSA due to glenoid component failure, revision with glenoid reimplantation may be considered, but is associated with a high rate of recurrent glenoid loosening. Alternatively, revision to a reverse shoulder arthroplasty, is feasible, but is technically demanding with high complication and reoperation rates. This paper will discuss the etiology, work-up, and treatment of patients with glenoid component failure following TSA

In the past century several shoulder reconstruction systems with different types of prostheses and fixation methods have been developed to improve shoulder arthroplasty, especially to cover a wide range of pathologies and revision situations. The aim of this prospective trial was to report clinical and radiological mid-term results of a stemless humeral head replacement with metaphyseal hollow screw fixation. A consecutive series of 147 shoulders in 138 patients (84 female, 54 male; mean age of 67 years, range 40–84) undergoing stemless humeral head arthroplasty were considered for this single-centre trial. We prospectively followed 120 shoulders (40 hemi- and 80 total-arthroplasties) for an average of five years or until a reoperation. Patient's clinical and functional outcome was evaluated according to the Constant score and active range of motions (ROM) was measured. Patient's satisfaction with the treatment was evaluated. Additionally, operating times and complications were recorded. Radiological assessment for radiolucencies or implant migration was performed. The mean Constant score significantly increased from 35 points preoperatively to 62 points at the last follow-up (p<0.001). All subcomponents (pain, daily activity, ROM, strength) of the Constant score were significantly (p<0.001) higher at follow-up. Active flexion improved from 90° to 150° (p<0.001), active abduction from 78° to 120° (p<0.001), and active external rotation from 20° to 40° (p<0.001) between preoperative and last clinical assessment. Furthermore, 54% of the patients were very satisfied, 34% satisfied, and 12% unsatisfied. Operating times of the new stemless prosthesis were significantly shorter compared to a stemmed prosthesis. Over the follow-up period, all humeral head components were radiological centred, changing radiolucencies were detected; however no implant loosening occurred. Revision surgery for implant loosening only occurred in the metal-backed glenoid component with hollow screw fixation; otherwise no complication due to implant loosening was detected. The promising five-year results suggest that the concept of this stemless humeral head replacement might be an expedient alternative to existing shoulder replacements. Anatomical cutting of the humeral head and hollow screw fixation allow a familiar access to the glenoid combined with a shaft independent, less complex bone-sparing surgery along with shorter operating times and favourable revision situation