Failed glenoid component after anatomic shoulder arthroplasty with glenoid bone deficiency

This is an interesting case of a middle aged patient who was seen in the office because of shoulder pain for the past 5 years. The patient had 15 years ago an anatomic shoulder replacement. Radiographic evaluation demonstrated well fixed press fit stemmed anatomic shoulder arthroplasty - implant that is not available in the US market anymore - and fractured glenoid with posterior displacement of the all poly glenoid component. There was no clinical signs of infection and the patient was keeping the arm in a sling for the past several years for comfort. Due to the young age of the patient and the history of multiple falls a decision was made to revise the implant to a smaller size humeral head hemiarthroplasty and avoid implantation of a reverse shoulder arthroplasty.

During surgery the keeled glenoid component was found loose, with loose cement, there was metallosis and 50 % of the posterior glenoid bone was deficient with a step off of 5 mm.

The purpose of the revision was to provide a less painful prosthetic implant that will allow the patient to use the wheelchair which is necessary to this patient for transportation.

Total shoulder replacement after proximal humerus fracture malunion

In this case a total shoulder replacement was performed, despite the proximal humeral deformity due to the malunion. The patient had an intact rotator cuff on the MRI and was very active with preoperative shoulder active forward elevation to greater than 140 degrees. The superimposed MRI on the postoperative Grashey X-ray is an alternative method of assessing the position of the humeral head, because the landmarks are changed due to the proximal humerus deformity. (see last image of this post)

Revision of failed anatomic total shoulder arthroplasty to hemiarthroplasty

The revision of the failed anatomic total shoulder arthroplasty (TSA) to a reverse is not ideal for the young active patient. The reason is that the reverse TSA is a reconstructive procedure that can provide restoration of function for those cases for a limited timeframe.  There is no further reconstruction that can be offered once the reverse TSA fails which is usually 5-10 years after the surgery. Thus, for the young patient (age in 50s- early 60s) the preferred revision is conversion to a hemiarthroplasty. More importantly, when the rotator cuff is intact it is preferred to avoid conversion to a reverse TSA. 

The following case illustrates an example of conversion of a failed TSA to a hemi. The failure was within 2 years from the index procedure and the patient was referred to us after his surgery for a painful stiff shoulder.

The prosthesis was "proud" and there was excessive amount of cement on the glenoid side and the glenoid component was loose. Four out of the six cultures indicated p.acnes infection with a normal preoperative lab work and no wound problems prior to revision surgery. These cultures became positive on day 7 and the patient was placed on Augmentin 875 BID prophylactically on day 1 as there was a suspicion of infection as well. Despite the positivity of the cultures, the one stage revision to a hemi-arthroplasty resulted is complete relief of pain on postoperative day 10 and no use of pain medication. 

As seen on the x-rays below the "proud" stem was the result of oversizing the stem diameter, which resulted in proximal distal fixation, incomplete advancement of the implant in the endosteal canal and a "proud" position of the humeral head.  In other words, the stem could not be advanced further into the canal as the distal portion of it engaged fully into the canal prior to complete seating proximally.

In this case, vertical osteotomy of the humerus was performed for extraction of the humeral stem and re-implantation of a smaller in diameter stem which allowed anatomic fixation and complete seating of the humeral head.

The excessive cementation of the glenoid as seen in the clinical photos is an independent factor for early failure as demonstrated by the work done at the UW Medical Center in Seattle, WA.

Suggested reading: 

Hackett DJ Jr, Hsu JE, Matsen FA 3rd. 

Primary Shoulder Hemiarthroplasty: 

What Can Be Learned From 359 Cases 

That Were Surgically Revised? Clin Orthop Relat
Res. 2018 Feb 21

Grashey view prior to index procedure

Failed anatomic TSA, loose glenoid component and proud humeral prosthesis due to "oversized" distal diameter of the stem which does not permit advancement in the endosteal canal.

Revision to hemi with undersized stem after vertical proximal humerus osteotomy and repair of the osteotomy side with four No 2 Fiberwire sutures.

Excessive cementation of the glenoid component, early loosening without fracture or wear or perforation.

Obesity and total shoulder replacement

Most surgeons who perform hip and knee arthroplasty procedures agree that there are significant risks and complications seen in patients with  a high BMI >40. For the shoulder replacement surgery the anesthesia risks are the same with the hip and knee arthroplasty procedure, however there are significant risks of mechanical complications. These reoperations and complications, most of the time, have to do with difficulties reaming the glenoid or exposing the humerus to gain access to the endosteal canal. For the following case the difficulty was that the large size of the brachium made full adduction and 90 degree humeral external rotation challenging. The incomplete adduction was forcing the reaming and work in the endosteal canal away from the surgeons making the procedure difficult. Despite the challenges there was no malpositioning of the components and the outcome was good, as the patient was able to perform assistive forward elevation of the shoulder to 150 degrees on postoperative day one. However, patients with BMIs between 40-50 should be consulted that they there are high risks of wound infections and component malpositioning. 

Suggested reading: 

Wagner ER, Houdek MT, Schleck C, Harmsen WS, Sanchez-Sotelo J, Cofield R,

Sperling JW, Elhassan BT. Increasing Body Mass Index Is Associated with Worse
Outcomes After Shoulder Arthroplasty. J Bone Joint Surg Am. 2017 Jun
7;99(11):929-937.