Abstract
The primary goals of successful rTSA (Reverse Total Shoulder Arthroplasty) are pain relief, improved shoulder motion and function with the restoration of patient independence. These goals can be achieved by optimal prosthesis design and surgical technique.
Historically there have been two predominant reverse shoulder design philosophies: the traditional valgus 155-degree neck-shaft angle with a medialised center of rotation introduced by Dr. Grammont, and the more recent varus 135-degree neck-shaft angle with a lateralised center of rotation, developed by Dr. Frankle. The latter design has reported lower incidences of scapular notching, coupled with improved adduction and external rotation. Over time, an understanding of the factors which resulted in clinical complications and those that contributed to the clinical success of both these design philosophies has been analyzed and widely publicised. With the currently available reverse prostheses the surgeon is required to be committed to one design philosophy or the other. This commitment to one singular design may hinder surgeons from the ability to individualise each case regardless of patient anatomy, rotator cuff condition, arthritic state and post-operative expectation.
Recently, a system has been launched which offers both design philosophies in one system, providing unsurpassed intra-operative flexibility. This allows the surgeon to adapt to each individual case and choose either design philosophy based on patient condition and anatomy, thus optimizing patient outcome.
The treatment of proximal humeral fractures has historically included Hemi Arthroplasty (HA) or Total Shoulder Arthroplasty (TSA). However, rTSA has recently become the surgery of choice for many fracture treatments based on more reproducible results. Certain implant characteristics are gaining favor in the treatment of proximal humerus fractures namely:
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Press fit humeral stems - which avoid the risks of cement in-between the tuberosities which has been reported to compromise healing.
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Proximal ‘box-shape’ geometry - which enables rotational stability especially in cases with proximal bone loss to promote reconstruction leading to improved healing.
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135-degree neck-shaft angle - allowing a higher and more anatomic tuberosity position for more stable fixation maintains anatomical integrity of the tuberosities which has been reported as a critical factor for retaining rotator cuff function.
