ARTHROPLASTY IN THE FACE OF CUFF DEFICIENCY

Abstract

1. Introduction

   • Definition-in this presentation, the discussion will not include reparable cuff deficiency, as this is handled with standard arthroplasty techniques combined with cuff repair

   • Factors that affect decision-making

     1. Kinematics-fixed fulcrum or not

     2. Bone loss

     3. Deltoid integrity

     4. Coracoacromial arch integrity

     5. Age

     6. Activity level

   • Options

     1. Hemiarthroplasty

     2. “ Extended head” hemiarthroplasty

     3. Arthroplasty + tendon transfer

     4. Constrained arthroplasty – currently not FDA approved in USA

     5. Arthrodesis

2. Evaluation

   • History and physical examination

     1. ? Prior surgery

     2. ? Overhead function – does fixed-fulcrum kinematics exist even if the head is not centred

     3. ? Anterosuperior instability – lack of fixedfulcrum kinematics

     4. Cuff strength

     5. Deltoid integrity

   • Radiographs – bone loss, especially glenoid

   • Other imaging studies not necessary

3. Arthroplasty

   • Hemiarthroplasty

     1. Best if fixed fulcrum kinematics exists – intact CA arch, intact deltoid, at or above shoulder elevation

     2. Technical considerations

        1. Preserve deltoid

        2. Preserve coracoacromial ligament, acromion

        3. ? Preserve remaining subscapularis – make humeral cut superiorly, through the rotator cuff defect

        4. Alternatively, take down subscapularis and capsule in one layer, mobilise and repair or transpose superiorly

        5. Increase retroversion of humeral cut- be careful of posterior cuff (teres minor) attachment

        6. Glenoid deficiency – especially if anterior or anterosuperior instability is present. May need to graft glenoid with head.

        7. Humeral head size-the same size or slightly larger than the one removed; avoid overstuffing

   • “Extended head” hemiarthroplasty (CTA head)

     1. Indications same as hemiarthroplasty

     2. Advantages

        1. Provides resurfacing of greater tuberosity, which is articulating with the acromion and often irregular

        2. Potentially improves kinematics by providing a “pain free” fulcrum

     3. Technical considerations

        1. Difficult but not impossible to do through a superior, subscapularis sparing approach

        2. Special jig required for cutting tuberosity

        3. Preserve CA arch

        4. Preserve deltoid

        5. Increase retroversion (be careful of remaining posterior cuff attachment)

        6. Glenoid deficiency – especially if anterior or anterosuperior instability is present. May need to graft glenoid with head.

        7. Humeral head size-the same size or slightly larger than the one removed; avoid overstuffing

   • Hemiarthroplasty + tendon transfer

     1. Indications

        1. Complete subscapularis deficiency

        2. Posterior cuff insufficiency with anterosuperior subluxation or dislocation

     2. Techniques

        1. Latissimus transfer – posterior cuff insufficiency

        2. Pectoralis major transfer – subscapularis insufficiency

           1. Deep to conjoined tendon (Resch)

           2. Superficial to conjoined tendon (Rockwood and Wirth)

        3. Combined

   • Constrained arthroplasty

     1. Not FDA approved in US

     2. Delta III – reverse prosthesis

        1. Reasonable results with medium-term follow-up in Europe (5–10 years)

4. Rehabilitation

   • Limited goals

   • Primary goals are pain relief and stability

   • Passive flexion to 90°, passive ER to 30° for 4 weeks

   • Advance stretches and add active range of motion and active assisted range of motion (overhead pulley) at 4 weeks

   • Strengthening – 6 weeks

5. Results

   • Less predictable and less functional overall than most other disease categories (e.g., OA)

   • Average elevation in most series is 120°

   • Usually good pain relief except in patients with anterosuperior subluxation