Implant removal after clavicle plating is common. Low-profile dual mini-fragment plate constructs are considered safe for fixation of diaphyseal clavicle fractures. The aim of this study was to investigate: (1) the biomechanical competence of different dual plate designs from stiffness and cycles to failure, and (2) to compare them against 3.5mm single superoanterior plating.

Twelve artificial clavicles were assigned to 2 groups and instrumented with titanium matrix mandible plates as follows: group 1 (G1) (2.5mm anterior+2.0mm superior) and group 2 (G2) (2.0mm anterior+2.0mm superior). An unstable clavicle shaft fracture (AO/OTA15.2C) was simulated. Specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with torsion around the shaft axis and compared to previous published data of 6 locked superoanterior plates tested under the same conditions (G3).

Displacement (mm) after 5000 cycles was highest in G3 (10.7±0.8) followed by G2 (8.5±1.0) and G1 (7.5±1.0), respectively. Both outcomes were significantly higher in G3 as compared to both G1 and G2 (p≤0.027). Cycles to failure were highest in G3 (19536±3586) followed by G1 (15834±3492) and G2 (11104±3177), being significantly higher in G3 compared to G2 (p=0.004). Failure was breakage of one or two plates at the level of the osteotomy in all specimens. One G1 specimen demonstrated failure of the anterior plate. Both plates in other G1 specimens. Majority of G2 had fractures in both plates. No screw pullout or additional clavicle fractures were observed among specimens.

Low-profile 2.0/2.0 dual plates demonstrated similar initial stiffness compared to 3.5mm single plates, however, had significantly lower failure endurance. Low-profile 2.5/2.0 dual plates showed significant higher initial stiffness and similar resistance to failure compared to 3.5mm single locked plates and can be considered as a useful alternative for diaphyseal clavicle fracture fixation. These results complement the promising results of several clinical studies.

Purpose of the study: Revision shoulder arthroplasty is generally considered to be a difficult procedure yielding modest improvement.

Material and methods: We report a prospective study of 45 patients, aged 69.8 years (range 49–85 years). Thirty-two patients had a simple humeral prosthesis and thirteen a total prosthesis. A reversed prosthesis was used for all revisions. The reasons for the revisions were classified into five groups: failure of prosthesis implanted for fracture (36%), glenoid problems of a total shoulder arthroplasty (24%), prosthetic instability (18%), failure of a hemiarthroplasty implanted for rotator cuff tear (11%), failure of a hemiarhtroplasty implanted for post-traumatic osteoarthritis (11%). The revision consisted in replacement with a reversed prosthesis. Patients were assessed pre and postoperatively using the Constant score for the clinical assessment and plain x-rays for the radiological assessment.

Results: Forty-one patients were reviewed at mean follow-up of 42.1 months (range 24–92). The four other patients died during the first two postoperative years. Subjectively, 73% of patients were satisfied. The Constant score improved from 187.7 to 55.6 on average. The best gain was obtained for the pain and daily activities scores.

Discussion: Revision shoulder arthroplasty provides only moderate improvement. Neer called a limited goal surgery. Results published on revision shoulder arthroplasty using a non-constrained prosthesis show that the functional gain is moderate. Revisio with a reversed total prosthesis gives better results because of the lesser impact of the cuff deficiency. The rate of complications after revision is greater than with first intention implantations.

Conclusion: Use of a reversed total shoulder prosthesis for revision shoulder arthroplasty provides encouraging results in terms of the mid-term functional outcome.