Reconstruction or replacement? A challenging question in surgical treatment of complex humeral head fractures in the elderly

Factors that affect external rotation following reverse shoulder arthroplasty: a retrospective multi-centre study on 501 shoulders

INTRODUCTION

The purpose of this multi-centre study was to assess external rotation in a large cohort following reverse shoulder arthroplasty (RSA) at a minimum follow-up of 2 years, and identify factors that influence postoperative and/or net-improvement of external rotation.

METHODS

The authors retrospectively reviewed records of 743 RSAs performed between January 2015 and August 2017 by 16 surgeons that participated in a large national society symposium; 193 (25.7%) were lost to follow-up, 16 (2.1%) died, and 33 (4.4%) were revised with implant exchange, which left 501 available for assessment at 2.0-5.5 years. Pre- and post-operative active forward elevation, active external rotation (ER1), active internal rotation (IR1) and constant score (CS) were collected. Regression analyses were performed to determine associations of patient demographics, surgical and implant parameters, rotator cuff muscles status and radiographic angles with ER1.

RESULTS

Multivariable analyses revealed postoperative ER1 decreased with age (β, - 0.35), increased with lateralisation shoulder angle (LSA) (β, 0.26), and was better in shoulders operated by the antero-superior (AS) approach (β, 11.41), but worse in shoulders with absent/atrophic teres minor muscles (β, - 10.06). Net-improvement of ER1 increased with LSA (β, 0.39), was better with inlay stems (β, 8.33) and BIO RSA (β, 6.22), but worse in shoulders operated for primary OA with rotator cuff (RC) tears (β, - 16.26), for secondary OA due to RC tears (β, - 16.06), or for mRCT (β, - 18.96).

CONCLUSIONS

This large multi-centre study revealed that, at a minimum of 2 years following RSA, ER1 improved by 16.1°. Postoperative ER1 was better in shoulders which had normal or hypertrophic teres minor muscles, were operated by the AS approach, or with greater LSA. Net-improvement of ER1 was better in shoulders with inlay stems, with BIO RSA, or with greater LSA, but worse in shoulders with rotator cuff deficiency.

LEVEL OF EVIDENCE

IV.

Anatomically reduced fixation should always be considered when treating B and C proximal epiphyseal humeral fractures

Background

Proximal humeral fractures are commonly observed in elderly patients. Management of these injuries is controversial. Literature comparing locking plate fixation, arthroplasty, and conservative treatments show no clear advantages for any of these management strategies. Thus far, no study has considered anatomically reduced fractures obtained after locking plate treatment. To clarify the best surgical procedure in middle-aged patients, we considered outcomes and major complications leading to surgical revision following an anatomically reduced fracture fixed with locking plate and reverse shoulder arthroplasty (RSA) in the treatment of type B/C fractures in patients between 50 and 75 years of age.

Methods

This is a retrospective study including 59 patients between 50 and 75 years of age with type B/C proximal humeral fracture treated with RSA or with locking plate fixation (resulting in an anatomical reduction) between January 2010 and December 2018. Preoperative radiographs and computed tomography (CT) were evaluated in all patients. Clinical and radiologic follow-up was performed using range of motion (ROM), the Constant–Murley Score (CMS), the Oxford Shoulder Score (OSS), the Simple Shoulder Test (SST), the Subjective Shoulder Value (SSV), and visual analog scale (VAS). Major complications were considered.

Results

In the plate fixation group, ROM, CMS, SST, and VAS were higher than in the RSA group. Lower complication rates compared with the literature were observed in both groups. Anatomically reduced fracture fixed with plate and screw could outperform RSA in terms of outcome. In second-level centers where traumatology is performed by surgeons with great expertise in upper limb trauma, the choice between plate fixation and reverse arthroplasty should be made during surgery.

Conclusion

Anatomically reduced fractures showed better outcomes compared with RSA in type B/C fractures. Surgeons should always try to perform a reduction of the fracture in order to understand if a plate fixation could be feasible. If it is impossible to perform an anatomical reduction, we suggest to consider RSA. This is a retrospective observational study.

Effect of Pore Size of Porous-Structured Titanium Implants on Tendon Ingrowth

Purpose

The reconstruction of a tendon insertion on metal prostheses is a challenge in orthopedics. Of the available metal prostheses, porous metal prostheses have been shown to have better biocompatibility for tissue integration. Therefore, this study is aimed at identifying an appropriate porous structure for the reconstruction of a tendon insertion on metal prostheses.

Methods

Ti6Al4V specimens with a diamond-like porous structure with triply periodic minimal surface pore sizes of 300, 500, and 700 μm and a porosity of 58% (designated Ti300, Ti500, and Ti700, respectively) were manufactured by selective laser melting and were characterized with micro-CT and scanning electron microscopy for their porosity, pore size, and surface topography. The porous specimens were implanted into the patellar tendon of rabbits. Tendon integration was evaluated after implantation into the tendon at 4, 8, and 12 weeks by histology, and the fixation strength was evaluated with a pull-out test at week 12.

Results

The average pore sizes of the Ti300, Ti500, and Ti700 implants were 261, 480, and 668 μm, respectively. The Ti500 and Ti700 implants demonstrated better tissue growth than the Ti300 implant at weeks 4, 8, and 12. At week 12, the histological score of the Ti500 implant was 13.67 ± 0.58, and it had an area percentage of type I collagen of 63.90% ± 3.41%; both of these results were significantly higher than those for the Ti300 and Ti700 implants. The pull-out load at week 12 was also the highest in the Ti500 group.

Conclusion

Ti6Al4V implants with a diamond-like porous structure with triply periodic minimal surface pore size of 500 μm are suitable for tendon integration.