Shoulder and Elbow cases chronic dislocation

A 56-year-old male presents to your clinic 2 months after a polytrauma MVA. He was in the ICU, intubated for a week after his initial injury, and has trouble recounting the details of his hospitalization. He does recall being diagnosed with a frozen shoulder. He is currently at a rehabilitation facility and has noticed

improvement in his shoulder although still reports soreness and significantly limited ROM.

The next step in management should be?

1. X-ray

2. MRA

3. Cortisone injection

4. Rotator cuff strengthening program

5. Continue PT

 

Discussion

The correct answer is (A). The first step in management of this patient is obtaining a complete set of x-rays to rule out a missed shoulder dislocation (as seen in Fig. 2–45). Answers C to E describe various treatment modalities, but these cannot be instituted without a firm diagnosis. An MRA (Answer B) is most commonly used when a labral tear is suspected, but an x-ray would be the first imaging modality utilized.

 

 

 

Figure 2–45 Axillary view demonstrating a chronic anterior shoulder dislocation.

 

Chronic shoulder dislocations are relatively uncommon injuries but represent a significant challenge even for the experienced provider. There are varying opinions on what duration of time a shoulder needs to be dislocated to be termed “chronic.” Three to four weeks is a commonly accepted timeframe, although any dislocation that is not identified and treated at the time of injury can be defined as chronic. This

most frequently occurs in a polytrauma patient where other, more life-threatening injuries, may cause a provider to overlook the shoulder. Treating chronic, glenohumeral dislocations can be very challenging, so the most important goal is preventing the problem by minimizing the risk of missing an acute dislocation. This is most easily done with a complete set of x-rays on any patient with a suspected shoulder injury. Obtaining an axillary view or Vallpeau view is essential as these views will most clearly demonstrate the position of the humeral head with respect to the glenoid. An AP and even a scapular Y view are insufficient to diagnose a shoulder dislocation, and an inability to obtain a Grashey view should clue the provider into a possible dislocation.

These patients frequently present with a visible asymmetry when examined with their shirts off. This may not be apparent in overweight or muscular patients. Patients will have limited range of motion (ROM); classically chronic anterior dislocations present with limited forward flexion, abduction and internal rotation, and chronic posterior dislocations with limited external rotation. However, unlike in acute dislocations, the ROM is often within a functional range, particularly if the shoulder has been dislocated for a prolonged period of time. In these situations pain tends to be fairly minimal as well. Muscle strength may or may not be preserved.

As previously mentioned, x-rays are of critical importance. A CT scan is often useful to further define bony abnormalities and an MRI can help detect associated soft tissue conditions.

There are several pathoanatomic changes that are noted with chronic dislocations. These include: osteoporosis softening of articular cartilage, soft tissue contractures, adhesions that may involve neurovascular structures, rotator cuff tears (particularly the subscapularis with anterior dislocation), glenoid bone deficiency, and a humeral head impression fracture. The degree of these changes to some extent depends on the duration of dislocation. All of these need to be taken into account when formulating a treatment plan.

Treating chronic dislocations can be challenging. It is important to evaluate each patient individually and take into consideration the direction and duration of dislocation, size of the humeral head impression fracture, degree or glenoid bone loss, status of articular cartilage, and most importantly their functional limitations and baseline level of activity.

Nonoperative treatment may be appropriate for low demand patients as many can regain a functional ROM with minimal pain and sufficient strength after physical therapy. Closed reduction may be considered if the dislocation is <4 weeks old and it is felt that the reduction will be stable. A large glenoid defect or a large

humeral head impression fracture, which are predictors if instability, are relative contraindications to this. Open reduction is frequently necessary in younger and high demand patients. In this situation, stability must also be addressed at the time of reduction. Generally speaking, the head impression fractures involving >20% of the humeral head will require an additional procedure to fill the defect to confer stability.

The stabilization procedure for anterior dislocations could involve: capsulolabral repair, disimpaction of the humeral head and bone grafting, size-matched allograft replacement when the remaining cartilage is healthy, or infraspinatus transfer with or without the greater tuberosity (to fill the humeral head defect) using a dual anterior and posterior approach. Similar options exist for posterior dislocations although the transfer would involve a subscapularis/lesser tuberosity transfer, which can be done entirely from an anterior approach.

Additional Questions

A 27-year-old banker with a seizure disorder presents to your clinic with shoulder pain and stiffness for 1.5 months since his last seizure. His X-ray is shown below (Fig. 2–46).

 

 

 

Figure 2–46

 

Which of the following is not an appropriate treatment option for this patient?

1. Open reduction and immobilization if stable

2. Open reduction and subscapularis transfer

3. Open reduction and greater tuberosity transfer

4. Open reduction and humeral head disimpaction and bone grafting

5. Open reduction and size-matched allograft transfer

 

Discussion

The correct answer is (C). The image demonstrates a chronically dislocated posterior glenohumeral dislocation. At 1.5 months, a dislocation closed reduction is unlikely to be successful. Each of the answer choices shows an acceptable treatment option depending on the stability of the reduction and the size of the humeral head impaction fracture except for Answer C, open reduction and greater tuberosity transfer. This would be used for posterior defects that would be seen with anterior dislocations.

A 35-year-old male has an 8-week-old chronic, anterior dislocation that has failed conservative management. At the time of open reduction, it is noted that his humeral head continues to sublux anteriorly. The surgeon decides to proceed with a greater tuberosity transfer to fill this defect and create a more stable glenohumeral complex.

What was likely the size the humeral defect?

1. 5%

2. 15%

3. 30%

4. 60%

5. 70%

 

Discussion

The correct answer is (C) (see Fig. 2–47). Humeral head impaction fractures involving less than 20% of the humeral head (Answers A, B) are often stable after open reduction and can do well with just a soft tissue procedure. Impaction fracture involving 20% to 40% (Answer C) frequently require an additional procedure to address the bony defect which may include disimpaction and bone grafting, allograft reconstruction, or infraspinatus/greater tuberosity transfer. Glenoid bone grafting may be needed as well, particularly if the glenoid bone loss is >20% to 25%.

 

 

 

Figure 2–47 The size of the humeral head defect can be calculated by dividing the arc of impaction (x) by the total articular surface arc (y).

 

Humeral head defects >40% (Answers D, E) frequently require a large allograft or prosthetic reconstruction. If a prosthetic option is chosen, some authors recommend placing the prosthetic glenoid component in 10 to 15 degrees of retroversion for an anterior dislocation and doing the opposite for a posterior dislocation.

 

Objectives: Did you learn...?

 

 

 

To recognize the common presentation of a patient with a chronic dislocation? To recognize the pathoanatomic changes associated with a chronic dislocation? The various treatment options and indications for their use?