Hockey players are known to often have shoulder issues. Some of these shoulder problems can be attributed to the prolonged bent over posture with shoulders protracted while others, like shoulder dislocations, can be caused by the high velocity impact absorbed by the shoulder from high-speed collisions and falls.
Shoulder dislocations in hockey players can be overwhelming and frustrating because of the generally unstable nature of the shoulder. As clinicians, we want to make sure we are preparing players as best as we can to successfully return at the lowest risk of reinjury. This can become challenging when treating hockey players with shoulder instability because of the unpredictability of hits and shoulder positions players might get into.
So here are 5 considerations to keep in mind that might be helpful when treating hockey players after a shoulder dislocation.
#1 Direction of instability
The most common direction of shoulder dislocation is anterior or anteroinferior. In hockey players, a dislocation can occur by a couple of different mechanisms. First, a fall on an outstretched hand with the shoulder in abduction, horizontal abduction can cause the humeral head to slide anteriorly and inferiorly from the glenoid. Second, a direct anteriorly directed impact can force the humeral head to separate from the glenoid anteriorly. Both of these mechanisms can lead to anterior instability of the shoulder
But in hockey, we might see more posterior dislocations then in the general population, again because of the high incidence of body contact and falls. In this case, a player would try to absorb a hit with their arms out in front of them, indirectly forcing the humeral head to separate from the glenoid posteriorly. This mechanism can lead to posterior instability of the shoulder.
Now what’s interesting with the shoulder is this “circle concept” of the surrounding tissues. Essentially what happens when the humeral head dislocates in one direction, there is damage to the tissues in that direction, but it also pulls on the tissue in the opposite direction causing damage there as well. So, a player with an anterior dislocation will have anterior instability but might also have some posterior instability because of the stretching of the posterior tissues.
#2 Concomitant pathologies
In order for a shoulder to dislocate, there must be some tissue damage. One of the more common pathologies that occur with shoulder dislocations is a Bankart lesion, where the anterior capsule is pulled off of the glenoid. This can also lead to a SLAP lesion (Superior Labrum Anterior to Posterior) where the avulsion of the anterior capsule continues into the anterior labrum. Dwyer et al found that 75% of hockey players with a shoulder dislocation also suffered Bankart/labrum lesions. Both of these concomitant pathologies will directly impact the degree of stability of the shoulder.
With shoulder dislocations, players can also suffer bony pathologies. Commonly seen with this injury are Hill Sach lesions, where the impact of the humeral head on the glenoid rim creates a lesion on the humeral head. Dwyer et al also found that 54% of dislocations in hockey players also suffered Hill Sach lesions. Additionally, the glenoid can also be fractured. As the glenoid plays a role in the stability of the shoulder, the effect of a fractured glenoid rim on passive stability of the shoulder will be proportionate to the size of the lesion.
#3 Scapular muscles
As I mentioned earlier, hockey players are known to have shoulder problems from prolonged postures on the ice. We can often see players with poor thoracic mobility with protracted shoulders. This can be problematic after a dislocation because if the humeral head is already anterior on the glenoid, it is already that much closer to its end range of translation.
Upward rotation of the scapula also helps to keep the humeral head centrated in the glenoid during shoulder elevation. A good analogy I like from Mike Reinold is one where he compares the centration of the humeral head on the glenoid like a seal balancing a ball on its nose.
Working on periscapular muscle strength and control can help keep the humeral head centrated for longer during overhead motion and can improve stability of the GH joint in these higher risk positions.
#4 Proprioception and neuromuscular control
Proprioception and neuromuscular control are crucial for successful rehab of a shoulder dislocation. The ligaments, labrum and capsule all contain afferent nerve fibers sending signals to the CNS on joint position and movement. When these structures are damaged, the signal transmission is often affected, and proprioception is reduced. Not to mention the loss of passive stability also from damage to these tissues, proprioception and neuromuscular control of the rotator cuff muscles is so important for shoulder stability after a dislocation.
Interestingly, poor shoulder proprioception and neuromuscular control could also have an impact on shot accuracy. Michaud-Paquette et al found that the lead elbow and shoulder motions during wrist shots accounted for an estimated 50% shot accuracy prediction which would suggest that the dynamic control of the lead arm helps to reorient the stick to for optimal orientation, height and velocity of the shot. Poor proprioception and control of the shoulder could lead to more variability in stick orientation and less accurate shooting.
#5 High rates of reinjury
Even after doing all the right things when treating shoulder dislocations in hockey players, unfortunately there is still a rate of reinjury.
Hovelius et al found that in a group of 63 players Swedish hockey players who suffered from shoulder dislocations, 76% had recurring dislocations. They also found that player age at first dislocation was a significant risk factor for recurring dislocations. 90% of players under 20 years old, 65% of players between 20-25 and 50% of players over 25 suffered second dislocation. These high rates are likely related to the contact, as similar results have been shown in other contact sports (Arciero et al).
In the case of recurring dislocations, the next step is often surgery. However, Hovelius et al found that 1/3 of players are able continue to play with recurring dislocations. That being said, this is not an ideal situation however, it suggests that a player may be able to finish the season before having surgery.
Considerations for Treating Shoulder Dislocations in Hockey Players
In summary, there are some small differences in treatment of shoulder dislocations in hockey players depending on the direction and concomitant pathologies. And although conservative treatment may not have great long-term success, it can be used with some success to help players get through the seasons.