Replacement
Revision Shoulder Replacement
Taking hold of life: Brushing your hair, Getting dressed, Carrying groceries and sleeping through the night. These are just a few of the life basics that can be difficult without full use of your shoulder. Fortunately, there are many ways to treat shoulder pain. One option is shoulder replacement surgery.
The shoulder is a ball and socket joint that is made up mainly of two bones. The ball portion of the joint is part of the upper arm bone (humerus). The socket portion is part of the shoulder blade. The ball fits into the socket, allowing the shoulder to move.
The ball and socket are covered with a smooth rubber-like coating called “cartilage”, The cartilage prevents direct contact between these bones and allows them to move smoothly over each other, without friction or wear on the bone surfaces.
Damage to the cartilage will make the shoulder movement painful and this condition is called arthritis.
Three common conditions that damage the cartilage
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Wear and tear osteoarthritis: The problem starts when the cartilage is injured or worn away -which is the definition of the osteoarthritis. The bones grind against each other, and that grinding hurts. Eventually, all that friction causes the bones surfaces to deteriorate. Unfortunately, no medication or treatment will make damaged cartilage grow back.
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Proximal humerus fracture: A Proximal humeral fracture is just a medical name for a broken shoulder. (Specifically, it means a fracture of the upper arm at the shoulder joint.) The injury is especially common among older people who have osteoporosis, which causes the bone to become more fragile over time – making it vulnerable to fractures caused by falls or direct blows, like a car accident.
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Rotator cuff arthropathy: Rotator cuff is a group of the tendon that stabilizes the shoulder, tear in this tendon causes increased stress on the joints, leading to damage to the cartilage. This condition is termed as rotator cuff arthropathy.
Shoulder joint replacement is a technically complex procedure. Although total shoulder arthroplasty (TSA) results are usually successful, a subset of these procedures fails and require revision. Revision surgery is most often required for aseptic loosening, rotator cuff failure, infection, or instability.Revision of an anatomic arthroplasty (hemi- or total) to another anatomic arthroplasty has shown variable results, often dependent on the cause for revision or type of implant used.
Common causes of shoulder arthroplasty failure
Before embarking on a surgical revision of a shoulder arthroplasty it is important to determine the nature of the patient’s problems. The following is a list of the common causes of shoulder arthroplasty failure:
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Infection
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Reaction to polyethylene or polymethylmethacrylate
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Fracture
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Stiffness
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Poor rehabilitation
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Unwanted bone
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Tuberosity malunion
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Overstuffing of the joint
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Instability
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Anterior
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Subscapularis deficiency
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Glenoid component anteversion
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Tuberosity nonunion
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Supraspinatus/infraspinatus defect
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Humeral component anteversion or anterior head offset
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Insufficient anterior glenoid bone
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Posterior
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Glenoid component retroversion
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Posterior cuff defect
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Excessive humeral component retroversion or posterior head offset
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Insufficient posterior glenoid bone
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Superior
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Loss of rotator cuff
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Loss of the coracoacromial arch
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Weakness
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Reduced muscle strength
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Subscapularis deficiency
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Supraspinatus/infraspinatus deficiency
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Tuberosity nonunion or malunion
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Deltoid detachment
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Nerve injury
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Humeral component
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Malpositioned
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Loose
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Glenoid
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Bone eroded (hemiarthroplasty)
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Component malpositioned
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Component lose
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Preparing for Revision Surgery
The history and previous records are reviewed to learn the patient's status and shoulder before the index arthroplasty.
What were the reconstruction details, including the manufacturer, model, and size of the prostheses? How was the rehabilitation conducted? Is there evidence of infection or an allergic reaction? Has there been an intercurrent injury? What is the patient's status with respect to nutrition, pain, medications, smoking, alcohol, and other concurrent health conditions?
The workup includes a detailed examination of the motion, stability, strength, and smoothness of the shoulder.
EMG's and nerve conduction studies, CT scans, and expert sonography may help evaluate the nerve function bone and rotator cuff, respectively.
Laboratory studies include a CBC sedimentation rate and serum albumin. Radiograph includes an anteroposterior view in the scapular plane, an axillary view and a full-length humeral view.