Treatment outcomes

The key to evaluating the outcome of surgery is a quick, sensitive, validated tool by which the patient can document the status of his/her shoulder before and sequentially after treatment without having to return to the office = the Simple Shoulder Test.  This simple metric that we introduced in the mid 1990’s has been used in over 200 publications and in multiple languages around the world.  It has become the benchmark for cost-effective patient-reported documentation of the shoulder’s comfort and function.

The result of a treatment is determined by the 4 Ps: the characteristics of the patient, the shoulder problem being treated, the procedure used to treat the problem, and the physician rendering the treatment for the patient.

The value of an evaluation and management approach can be defined as the benefit to the patient divided by its cost. For example if a preoperative CT scan of an arthritic shoulder does not lead to an improved outcome for the patient, it is of less value than less expensive and less irradiating plain films. We use the concept of value to examine new technologies, such as patient-specific instrumentation, platform prostheses, and augmented glenoid components.

Glenohumeral stability

The primary stabilizing mechanism for the shoulder is concavity compression – the compressive action of the cuff and deltoid forces centering the humeral head in the glenoid concavity throughout the range of motion, including the many positions in which the ligaments are lax. Treatment of instability requires restoration of this mechanism.

An anatomic repair of the Bankart lesion is sufficient for the management of most cases of recurrent glenohumeral instability.  Bone transfers, such as the Latarjet procedure or iliac crest graft, have increased complication rates and morbidity – for those reasons they are reserved for cases of failed anatomic repairs or cases of massive glenoid bone deficiency.

Pain pump infusion of local anesthetics is not necessary in the management of glenohumeral instability and can lead to the complication of chondrolysis.

Sternoclavicular joint

The unstable SC joint can be safely reconstructed by an allograft weave.

Rotator cuff

An intact supraspinatus is not necessary to initiate abduction.

The outer aspect of the proximal humeral convexity normally contacts and articulates with the concavity of the coracoacromial arch, providing stability resisting superiorly directed forces.  This contact is not ‘impingement’.  Sacrifice of the CA arch by acromioplasty can lead to anterosuperior escape and pseudoparalysis.  The cuff muscles are not ‘head depressors’, but rather ‘head compressors’.

In patients with a symptomatic irreparable cuff tear and an intact coracoacromial arch, comfort and function can often be improved by a smooth and move procedure that removes roughness from the proximal humeral convexity and restores full passive range of motion without attempting a cuff repair or graft.

Acromioplasty is unnecessary in the treatment of cuff disease.

Recent ‘advances’ in rotator cuff repair techniques have not led to improved clinical results or to reduced rates of retear.  The integrity of the cuff repair is not strongly related to the clinical outcome of the surgery.

Arthritis

CT scans are unnecessary in the evaluation of most cases of glenohumeral arthritis. The key image is the ‘truth view’ – a standardized axillary view taken with the arm in a position of functional elevation.  This view shows the glenoid version, the glenoid type, and the degree of posterior functional decentering of the humeral head on the glenoid.

Lesser tuberosity osteotomy is not necessary to gain access to the glenoid or to achieve restoration of subscapularis integrity.  LTO has the disadvantage of compromising the ability to get a secure proximal press fit of the stem with impaction grafting.

Metal-backed glenoid components have a higher failure rate than all polyethylene pegged glenoid components.

”Correction” of glenoid retroversion is not a priority in shoulder arthroplasty; posterior decentering can be effectively managed by an anteriorly eccentric humeral head component and rotator interval plication.

Avoiding the use of a guide wire enables the surgeon to ream the glenoid to a single concavity with the removal of a minimal amount of bone. 3D planning based on CT scans and patient specific instrumentation add cost and radiation without documented benefit to the patient.

Bone ingrowth, porous coating, and trabecular metal are unnecessary for the fixation of the humeral component; robust, bone-conserving and durable fixation of the prosthesis can be reliably achieved by impaction autografting using bone harvested from the resected humeral head.

Impaction grafting facilitates the intra-operative adjustment of the height, version, and angle of the humeral prosthesis by selective addition and positioning of the graft.

The use of small diameter humeral stems along with impaction grafting avoids the stress riser at the tip of the prosthesis and avoids the risk of incomplete seating of the humeral stem due to incarceration of the prosthetic tip in the diaphysis.

Fixation of the humeral stem with impaction grafting greatly facilitates revision should that become necessary, eliminating the need to remove cement and minimizing the risk of fracture and the need for humeral osteotomy.

Excellent functional restoration for the arthritic shoulder can be achieved without the use of a prosthetic glenoid component. The ream and run procedure provides a non-prosthetic approach to glenoid arthroplasty, avoiding the potential risks associated with plastic and bone cement.

Cuff tear arthropathy

In patients with active elevation above 90 degrees and without anterosuperior escape, comfort and function can be improved using a CTA prosthesis that may be a preferable option (in comparison to a reverse total shoulder) for patients desiring heavy physical use of the shoulder or those who have a high fall risk.

Reverse total shoulder

Prostheses that enable immediate robust glenoid fixation with a large central screw and lateralization of the glenosphere provide secure glenohumeral stability and minimize the risk of scapular notching and polyethylene failure.

If the tuberosities are intact, secure humeral component fixation can be achieved with impaction autografting of a monoblock stem.

Periprosthetic infections

Cutibacterium are normal inhabitants of the dermal sebaceous glands where they cannot be reached by epidermal skin preparation and from where they are released into the wound by skin incisions or by needles used for injection.

Cutibacterium periprosthetic infections present in a “stealth” mode, rather than in the “obvious” mode characteristic of hip and knee periprosthetic infections.

Cutibacterium are the most common organisms to be recovered from failed arthroplasties. They can only be reliably recovered if special culture techniques are used and if the cultures are observed for three weeks.

Ceftriaxone and Vancomycin are preferred to Cephazolin or Clindamycin for preoperative prophylaxis due to the evolving sensitivity profile of Cutibacterium.

A single-stage exchange to an impaction allografted hemiarthroplasty is usually sufficient for the management of a periprosthetic infection with Cutibacterium.