Friday, February 3, 2017

Complications of shoulder joint replacement

Complications of Shoulder Arthroplasty

These authors retrospectively reviewed all articles on shoulder arthroplasty published from 2006 to 2015.  They defined a complication an event that resulted in an adverse outcome for the patient, irrespective of surgical revision. This analysis revealed a total of 19,262 anatomic (TSA) and reverse (RSA) shoulder arthroplasties at a mean follow-up of 40.3 months in 122  studies, with an overall complication rate of 7.4% (2,122 complications). These complications are of obvious cost to the patient and to society, so that these data motivate our efforts at improvement.

The most common complications with RSA are shown in the chart below

The most common complications after TSA are shown below

The authors point out that there is insufficient evidence to support claims that 

(1) "Bone-sparing humeral head resurfacing implants and short-stem humeral components demonstrate clinically proven advantages compared with conventional humeral head replacement arthroplasty".


(2) "Patient-specific instrumentation leads to improved anatomic placement of glenoid components, patient-reported outcomes, and implant survivorship"

Comment: One of the common indications for RSA is instability (including the anterosuperior instability from (a) the combined rotator cuff, tuberosity and coracoacromial arch deficiency, (b) the posterior instability from difficulties stabilizing the humeral head on a retroverted glenoid, and (c) anterior instability from subscapularis failure). While RSA is often effective in managing these conditions, this article shows that post-RSA instability remains a common complication. 

At RSA surgery, consideration needs to be given enhancing stability with East-West tensioning using extended glenopshere necks.
The stability of the reconstruction needs to be vigorously verified in all positions of the shoulder to assure proper tensioning and freedom from unwanted abutment of the humeral component on the scapula.

The high rate of fractures with RSA is related in part to the use of the RSA in revision arthroplasty requiring the often difficult removal of prior implants (see  Revision reverse total shoulder arthroplasty, a risky business).
The risk of fracture is also greater in the typically older individuals receiving RSA, especially when tight-fitting implants are used or when 'hip-style' cementing creates a stress riser at the prosthetic tip.

We try to minimize these risks by using 'humerus-friendly' impaction grafting to fix the humeral component.

Genoid component loosening remains the most common complication of anatomic TSA. As in the case shown below, excessive reaming, excessive cement, keeled glenoid components, glenoid component wear, incomplete seating, and the rocking horse phenomenon may all contribute to glenoid component loosening. 

It is now generally recognized that the rate of glenoid component loosening is not a linear function of time after surgery, but rather a complication that begins to rise in frequency 5 or so years after the arthroplasty (see Total shoulder arthroplasty failure).

Our approach to the glenoid component is to use an all polyethylene pegged component (below bottom) that avoids the excessive cement often used in fixation of a keeled component (below top).

The amount of bone removed by reaming is minimized. 

Radiolucencies between the cement and bone are minimized using a CO2 spray to dry the bone prior to cement pressurization and component insertion.

We suggest that improvements in surgical technique offer the greatest opportunity for minimizing the complications of shoulder arthroplasty.

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You may be interested in some of our most visited web pages including:shoulder arthritis, total shoulder, ream and runreverse total shoulderCTA arthroplasty, and rotator cuff surgery as well as the 'ream and run essentials'