Thursday, April 23, 2015

Are suspensions down in the NHL?

To follow-up on my post from yesterday, I wanted to investigate quickly whether suspensions have gone down in the NHL since the Department of Player Safety's introduction prior to the 2011/2012 NHL Season.

In my numbers I included only player suspensions (no head coach fines or games suspended) and did not include automatic suspensions or fines (leaving bench), just hits/penalties that lead to a suspension.



In the first season of the Department of Player Safety with Brendan Shanahan at the helm, the NHL handed out suspensions and fines like candy. Each fine was only $2,500 a rule which has since been changed.

Let's visualize this below:




There is a definite downward trend in number of suspensions in the NHL (and # of games obviously) even with the outlier that is the 2012-2013 lockout season. Expanding this to all incidents reviewed by the DOPS in general, there's still a downward trend:


So, what do you think? Is the Department of Player Safety noticeably taking issues less seriously since Shanahan's departure? Are NHL Players getting cleaner? Doubtful, considering there has only been a very slight downwards trend in total penalties (minors & majors) called, while a more drastic change has occurred in the number of incidents reviewed by the DOPS. 


Thanks for reading.


Wednesday, April 22, 2015

Legal vs. Illegal hits in the NHL - The inconsistency of the Department of Player Safety

WILSON 'STEAMROLLS' VISNOVSKY

Last night on Long Island, Tom Wilson of the Washington Capitals hit Lubomir Visnovsky of the New York Islanders near the 14 minute mark of the 2nd period. The video is below.


Wilson carries the puck through center ice on a rush, and throws the puck at the net from near the top of the face-off dot. Wilson's shot/pass attempt is foiled by Visnovsky who uses his stick to push the puck towards the corner. Wilson sees this and skates down the boards towards the back of the net in what looks like an attempt to retrieve the puck. Visnovsky never re-gained control of the puck, which dribbles towards the corner. Making no attempt to retrieve the puck (Wilson does not even look for it as he skates towards Visnovsky), Wilson steamrolls the vulnerable Visnovsky, making shoulder to head contact on Visnovsky, following through on the hit as Visnovsky falls directly backwards towards the ice.

Wilson was assessed a minor penalty for charging. Visnovsky left the ice with a bloodied face looking visibly shaken, having previously been hit in the head during the game. Visnovsky did not return to the game and his status for the rest of the series is unknown, however it is very likely the defender has suffered a concussion and will not return.

In my opinion, and that of the Islanders player's, Wilson isn't going for a hockey play. He makes no attempt at the puck, and it's clear he recklessly wanted to make a big hit.




Capital's players disagree. Brooks Laich told a Washington, D.C. radio station that the hit is "questionable" because the puck is a couple feet away but he felt that Wilson's hit was a "good penalty to take because it knocked the Isles down to 5 defensemen."
Barry Trotz and Wilson also felt the hit was clean in an interview with the Washington Post.

It was announced that the Department of Player Safety (DOPS) is not taking a look at the check. Even Matt Barnaby thinks that the hit should have been looked at by the Department of Player Safety.


DEPARTMENT OF PLAYER SAFETY'S RECENT DECISIONS 

March 26th, 2015 - CBJ Forward Jared Boll suspended 3 games for hit on Patrick Maroon

Video

During this play, Ducks forward Maroon collects the puck in the corner and starts to cycle, being defended by Jack Johnson behind him. Boll, approaches from face-off dot, and drives his right shoulder into the side of Maroon's head, elevating into the hit. The DOPS called this an illegal check to the head because the primary point of contact is Boll's head, and the contact is avoidable. DOPS states that despite the fact that Maroon is bent over, he doesn't change his posture and his head doesn't change directions or position prior to the contact. In what's a theme in DOPS videos, they state that the onus is on Boll (the hitter) to deliver a hit through the core of Maroon's body. Despite the fact that there was no injury, Boll unnecessarily elevated into the hit and is a repeat offender. He was suspended 3 games.


March 4th, 2015 - Islanders Forward Matt Martin suspended for kneeing Trevor Daley

Video

On this play, Daley is in his own zone and sees Martin approaching and chips the puck. Martin comes in with speed and checks Daley but it is textbook kneeing. Daley is eligible to be hit after just releasing the puck according to the DOPS, but Martin doesn't deliver a full body check and instead it results in kneeing causing an injury. Daley did not make a sudden or evasive move so again, the onus is on the hitter to make a legal check.

Note - this is the only hit I have chosen to include that doesn't involve contact to the head. The reason being that this hit included an injury, and the repeated statement that the onus is on the checker to make a legal check.

February 23rd, 2015 - Senators Jared Cowen suspended 3 games for hit on Jussi Jokinen

Video

On this play, Jokinen carries puck over Ottawa blue line in middle of ice and makes a backhand pass to a teammate. After Jokinen releases the puck, Cowen changes his skating angle towards Jokinen and eventually leans up and into a right shoulder check that makes significant head contact. The DOPS defined this hit as interference and a late hit because the hit was initiated after the puck had been moved and contact was made when Jokinen's teammate had the puck. On the hit, Cowen drives up and into Jokinen, hitting him in face. Despite no injury, Cowen is a repeat offender and was suspended 3 games.

January 28, 2015 - Zac Rinaldo suspended 8 games for boarding Kris Letang

Video

On this play, defenseman Kris Letang is in his own zone along the boards and attempts to chip puck out on a backhand. Flyers forward Zac Rinaldo approaches from the middle of ice and approaches Letang, seeing only his numbers. Rinaldo launches (leaving his feet) into a shoulder check hitting Letang into the boards (DOPS classified it as charging and boarding). Rinaldo hits him despite Letang not having the puck and the fact that he's facing the boards. Again the DOPS states that the onus on hitter to take an angle that enables him to hit from front or side or to just avoid contact. Since there was an injury on the play and Rinaldo is a repeat offender, he was suspended 8 games.

In fact, that play is very similar to the Evander Kane suspension for boarding Stoner, but Kane only received 2 games for that.  Video

January 2nd, 2015 - Keith Aulie suspended 2 games for hitting Matt Stajan

Video 

Here, Matt Stajan is rushing down the ice, attempting to receive a break-out pass. Aulie skates over and drives his shoulder into Stajan's head (defined as an illegal check to the head by the DOPS). The DOPS state that this is a blindside hit (which is not illegal on its own) but again, the onus is on the hitter to ensure that the head isn't primary point of contact. The DOPS state that Stajan's head is down but it's appropriate because he's looking to recieve a pass and that since his head position doesn't change, Aulie must attempt to make a better hit. The DOPS suspended Aulie for 2 games despite the fact that he didn't launch but he did take a poor angle and the PPOC was the head.


December 10th, 2014 - Marco Scandella suspended 2 games for hit on Brock Nelson

Video

On this play, Nelson wins a battle and carries puck into zone. Wild defenseman Marco Scandella steps up and clips Nelson's head (PPOC) with left shoulder - defined as an illegal check to the head by the DOPS. The DOPS state that Nelson is eligible to be checked but Scandella delivers an illegal check because the head was targeted and he did not hit through Nelsons's shoulder and chest. As head contact was avoidable in this situation (Scandella straightened up to hit him in the head) and Nelson's head position doesn't change prior to contact, Scandella was suspended for 2 games (he was fined for a similar hit three games before). Nelson was not injured on the play.

CONCLUSION

Any way you put it, Wilson's hit is not legal and deserved a penalty. Section 6, Rule 42 in the NHL Rulebook is Charging which is defined below.


In this case, the referee judged that Wilson skated into Visnovsky in a violent manner. As you can see, you do not need to leave your skates to get a charging penalty. It does not appear that Wilson leaves his skates, but he does launch up into the hit and the PPOC is Visnovsky's head.


Wilson's momentum is up into the contact, causing him to leave his skates. He follows through on his hit and eventually lands on Visnovsky.


So Wilson launches up from his hit, makes primary contact with Visnovksy's head and doesn't attempt to make a play on the puck, which is nowhere near. Yes, Visnovsky is crouching a bit as he braces for Wilson's hit, but he does not turn or change the direction of his head. Is it on Wilson as the checker to make a legal hit or avoid contact. Visnovsky's head is avoidable, so I'm not sure how this doesn't violate the NHL's Rule 48 (illegal check to the head) as shown below.



In addition, Visnovsky was injured on the play and is probably  finished for the series and possibly for his career. How does Wilson's hit differ in context to some of the DOPS other suspensions? There's an injury, the hit is avoidable, Wilson makes no play on the puck (breaking Charging & Interference rules) and the PPOC is the head.

Does the NHL need to clarify it's definition of illegal checks? Or checks to the head? Wilson clearly hits Visnovsky in the head on an avoidable hit, but it doesn't violate Rule 48? This is a rule that was made in response to a huge problem in the NHL - concussions. Visnovsky suffered a concussion on the play. Reckless hits in this sport need to fade away if we want to reduce concussions, but if hits like Wilson's aren't suspend-able, what's stopping players from continuing to do them?

Is the Department of Player Safety doing a poor job these playoffs? Have they defined head checks well enough? They are constantly criticized by fan bases across the league. I didn't even mention Dustin Byfuglien's Dale Hunter-like hit on Corey Perry. Comments/criticism always appreciated.



Friday, February 27, 2015

Patrick Kane's Clavicle Fracture

On Tuesday, February 24th, in the first period against the Florida Panthers, Chicago Blackhawks player Patrick Kane fell hard into the boards after a cross-check from Panthers defenseman Alex Petrovic. After receiving the cross-check, Kane lost an edge and fell hard, shoulder-first, into the half-wall. Kane didn't return to the game and Blackhawks coach Joel Quenneville said he may miss extended time.


The next day, the Blackhawks placed Kane on LTIR (player must be deemed unavailable for 24 days/10 NHL games, some cap relief) and Blackhawks fans waited for the bad news. It was later released that Kane had surgery to repair a broken left clavicle and would be out approximately 12 weeks.

That puts Kane on track for a return to play after the first two rounds of the Stanley Cup Playoffs, if the Blackhawks make it that far. Kane was on track to possibly be the first American-born Art Ross trophy winner, leading the league with 64 points in 61GP.

ANATOMY - WHAT IS THE CLAVICLE? 

The clavicle, commonly known as the collarbone, serves as the only bony connection (strut) between the arm  (Acromioclavicular Joint/Ligament/acromion/scapula) and the trunk (sternum). In fact, the clavicle is the first bone to ossify (turn into bone) in the human skeleton, taking place in the embryo during the 5th and 6th weeks of gestation. However, it's one of the last bones in the body to finish ossification, at somewhere around 21-25 years of age.

Pectoral girdle - Wikipedia
Normal shoulder ligaments: Anterior view - Wikipedia

The clavicle acts as a strut offering support and keeping the scapula in place, allowing your arms to hang freely. The bone is shaped like an "S," curving outward on the proximal half and curving inwards at the distal half where it attaches to the scapula.

THE INJURY - CLAVICLE FRACTURE

Clavicle fractures are categorized by location, known as the Allman classification [Allman]

  • Group I - Consists of fractures of the middle third
  • Group II - Consists of fractures of the distal third (can be further subdivided into three separate types)
  • Group III - Consists of fractures of the proximal third. 
A study of 1000 fractures of the adult clavicle in Edinburgh revealed that 69% of clavicle fractures occur in the middle third (Group I), while 28% occur in the distal third (Group II) and 3% occur in the proximal third (Group III) [Robinson et al.]. 

Approximately 87% of clavicle fractures are caused by a fall on the shoulder [Stanley et al.] and traffic accidents and sports account for the most fractures among young people [Robinson et al.]. 


UpToDate diagram - Depiction of the mechanism typically involved in the displacement of a clavicle fracture, showing an upward pull of the sternocleidomastoid muscle and the downward pull of the weight of the arm.

When a clavicle is fractured, patients usually have very localized pain that is exacerbated by movement of the arm along with swelling over the area. If a fracture is suspected, ice will be placed on the injury and the patient's range of motion must be reduced (with a sling). X-rays are the most common and basic method to check for a clavicle fracture, CT Scans/MRIs are only ordered in severe cases.

Group I fracture of the clavicle with complete displacement.
As the diagram above depicted, not the typical upward displacement of the proximal fragment (left) caused by the upward pull of the sternocleidomastoid muscle. [UptoDate Dr. Robert Hatch]

Group II fracture (distal third of clavicle) again showing characteristic upward displacement [UptoDate Dr. Robert Hatch]
After imaging, the physician determines which form of treatment is best - nonoperative or surgical. Surgery is usually performed when the bones are displaced or it's an open fracture (not common with clavicle fractures even though the clavicle is subcutaneous, meaning only under a thin layer of soft tissue).

Clavical fractures that require surgery often call for internal fixation, or the surgical implementation of implants for the purpose of repairing a bone. The most common for clavicle fixes is Open Reduction Internal [plate] Fixation (ORIF). During this operation, the surgeon first re-positions the bone fragments into their natural alignment and later affixes a plate along the superior portion of the bone with several screws. These plates/screws are rarely removed after the bone has healed unless they cause discomfort (nerve/tissue interaction/aggravation or infection).

Clavicle ORIF
Following the surgery, the patient is immobilized with a sling until clinical union occurs (usually a minimum of 2-6 weeks, may more). This is employed to allow bone and soft tissue healing and to avoid re-injuring when the bone is fragile. A clinical union is defined as when the fracture site is non-tender and the patient can move their arm through a full range of motion with little to no discomfort. This union usually occurs in 6-12 weeks in adults. Sometimes, scans are re-acquired to see if clinical union has occurred.

Surgery often leads to better outcomes. One systematic review of 2,144 clavicle fractures compared nonsurgical treatment to surgical treatment and found that patients treated nonsurgically had a 15.1% nonunion rate, while those in the surgical group only had a 2.2% nonuion rate. Additionally, the average time of clinical union in nonsurgical patients was 28 weeks, while it was around 16 weeks in surgical patients (in this particular study) [Canadian Orthopaedi Trauma Society]. The American Academy of Orthopaedic Surgeons recommends surgery for clavicle fractures because it yields better outcomes.

During the recovery period, patients usually undergo shoulder range of motion and strengthening exercises to help with recovery and rehabilitation. In the weeks following surgery, these exercises are limited (patients can't elevate surgical arm too high or lift any objects or do much reaching). Ice and pain medications are used to control swelling and inflammation as well. After about 4-6, the shoulder range of motion and strength exercises become more aggressive. In weeks 8-12, the patient seeks full shoulder range of motion but must be careful.


Return to play is very individualized in each case. Younger patients usually reach clinical union faster, however, recovery is completely dependent on fracture location/severity, the surgery success, rehabilitation and bone healing. Athletes shouldn't return to sport until they have a full range of motion and their shoulder has returned to normal strength.



SOURCES


  1. Allman FL Jr. Fractures and ligamentous injuries of the clavicle and its articulation. J Bone Joint Surg Am 1967; 49:774.
  2. Robinson CM. Fractures of the clavicle in the adult. Epidemiology and classification. J Bone Joint Surg Br 1998; 80:476.
  3. Stanley D, Trowbridge EA, Norris SH. The mechanism of clavicular fracture. A clinical and biomechanical analysis. J Bone Joint Surg Br 1988; 70:461.
  4. Hatch, R, Clugston, J, Taffe, J. Clavicle Fractures. In: UpToDate. Topic 231 Version 16.0. Last Updated  November 3, 2014. UpToDate. Waltham, MA. (http://www.uptodate.com/contents/clavicle-fractures) 
  5. Canadian Orthopaedic Trauma Society. Nonoperative treatment compared with plate fixation of displaced midshaft clavicular fractures. A multicenter, randomized clinical trial. J Bone Joint Surg Am. 2007 Jan;89(1):1-10.

Monday, February 23, 2015

Henrik Lundqvist - Internal Carotid Artery Dissection

Everyone loves Henrik Lundqvist. No seriously, everyone. I'm an Islanders fan and I can't but find him likable. He's one of the best goaltenders in the game.

On January 31st in a game against the Carolina Hurricanes, Rangers defenseman Ryan McDonagh attempted to clear the crease. Doing so, McDonagh's stick inadvertently came up and lifted Lundqvist's mask and shield, exposing Lundqvist's neck at the moment the high shot needed to be saved. The play can be seen below:



Lundqvist squirmed on the ice in obvious pain after taking the puck directly to his unprotected neck. Rangers trainer Jim Ramsay immediately started to pick up snow from the ice and apply to to Lundqvist's neck to relieve pain and swelling. After a few quick diagnostic tests (probably a concussion screen, Lundqvist shook off the pain and continued to play. Video of the whole incident can be seen below:


The next day Lundqvist tweeted that he was fine and even joked a bit:


Lundqvist recovered and started the next game on February 2nd. Lundqvist hasn't played since and on February 6th the Rangers announced he had a vascular injury and would be out 4-6 weeks.

THE INJURY

On Wednesday, February 4th, Rangers coach Vigneault told the media Lundqvist was being evaluated by doctors. On Friday, the 6th, it was released that he would be sidelined for at least 4 weeks with a neck injury and speculation begun (was it a concussion? was it nerve damage? a blood clot?). Then it was revealed that Lundqvist had a vascular injury and the hockey world promptly started googling and freaking out.  Artery injury?! Risk of stroke! Woah! The NHL has certainly had its fair share of serious and bizarre injuries over the past year, and even experienced stroke with star defenseman Kris Letang (which I wrote about here).

On February 8th, Lundqvist spoke to the media and said he "sprained a blood vessel" (not a real medical term) and that he was risking a stroke had he continued to play, admitting it wasn't a good decision to play on the 2nd, the game following his injury. Lundqvist also said that he felt lightheaded, dizzy, and experienced headaches after taking the shot to the neck.

So what is a vascular injury? Essentially, it's an injury to the blood vessels/arteries. Lundqvist took a shot to the neck, a vulnerable area because it's where the blood vessels which provide [oxygenated] blood to the brain are located. In Lundqvist's case, his vascular injury wasn't very traumatic - meaning his vessels weren't torn or cut (Clint Malarchuk anyone?). However, the direct impact did cause blunt trauma to his neck's blood vessels resulting in damage manifesting in some of the symptoms that he reported. 


The arteries of the neck [Wikipedia]

Given the placement of where the puck hit (front/anterior of neck), it's most definitely an injury to the carotid artery. The carotid artery, known as the common carotid artery, is a paired structure meaning that there are two, one on each side of the body/neck. The left carotid artery originates from the aortic arch while the right originates in the neck from the brachiocephalic trunk. These arteries supply the head and neck with oxygenated blood, dividing in the neck to form the external and internal carotid arteries. The internal carotid artery directly supplies the brain, while the external carotid brings blood to other portions of the head such as the face, scalp and skull. 



In the time following his injury, Lundqvist revealed that his neck was stiff, he had continued headaches, and felt light-headed. The stiff neck is a consequence of trauma to the neck muscles, and should resolve with a common regimen of ice & rest. The light-headedness, dizziness & headaches is what's concerning & is a direct result of his vascular injury.

Lundqvist suffered a vascular injury, meaning the trauma caused the structural integrity of the arterial wall to be compromised. In medicine, this is commonly known as an arterial dissection (Liebeskind & Saver). A dissection occurs with separation of the arterial wall layers, allowing blood to collect between layers (known as an intramural hematoma). When the interior arterial wall separates, it causes a false lumen to arise in the space where blood can seep into the vessel wall as seen below:

The progression of a dissection, thrombus development, and total vessel occlusion. Courtesy of Dr. Mounzer Kassab, Up To Date. 
When a dissection occurs, the arterial wall is thinner, and susceptible to causing the blood vessel to enlarge and/or form a clot. Blood can still flow through the vessel to provide oxygen to the brain, but the structure is weakened.

The frightening [small, but definite] risk with a carotid dissection, as Lundqvist mentioned, is a stroke. A clot can form over the vessel wall where it is separated and naturally healing. Said clot could break and dislodge, forming an emboli, which could travel to the brain and disturb the flow of blood supply, resulting in an ischaemic stroke. Dissection is a common cause of stroke in young adults, accounting for up to 25% of all stroke cases.

DIAGNOSING THE INJURY

While clinical features (such as headache, dizziness, even tinnitus) may raise a physician's suspicion for dissection, the actual diagnosis can only be made and confirmed with neuroimaging. Imaging must demonstrate one of a couple features to make a diagnosis;  a long tapered arterial stenosis, a tapered occlusion, a dissecting aneurysm (pseudoaneurysm), an intimal flap, a double lumen, or an intramural hematoma (Liebeskind & Saver).

After reporting his symptoms, Lundqvist presumably had a physical examination paired with an MRI/CT of the head and neck. While those two aren't used to diagnose a dissection itself, they aid in ruling out other possible injuries and point to the need to get more imaging, specifically those which provide images of the blood vessels.

Noninvasive imaging approaches such as Magnetic Resonance Angiography (MRA) and Computed Tomography Angiography (CTA) are the industry standard for diagnosing dissections and guiding treatment decisions. In fact, a 2009 study showed that both MRAs and CTAs diagnosis arterial dissections with relative similarity (http://www.ncbi.nlm.nih.gov/pubmed?term=19770343). Sometimes, a team of physicians will perform an MRA first, and then a follow-up CTA to confirm diagnosis.

Using imaging together - On the left is an MRI of the brain, showing a hemorrhagic crescent. On the right is a neck MRA, showing "string sign" consistent with dissection. (Source:  Pary LF, Rodnitzky RL. Traumatic internal carotid artery dissection associated with taekwondo. Neurology 2003; 60:1392)

A basic MRA image of the carotid arteries. 

In his case, Lundqvist's imaging most likely showed an abrupt narrowing of the [right] internal carotid artery, warranting an MRA/CTA. Lundqvist's MRA would then demonstrate a segment of dissection, most likely observed due to an intimal flap. When the internal lining of an artery tears, the blood (flowing at a high pressure) travels through the media as described above; this creates a false lumen (a newly created passageway). The false lumen is separated from the "true lumen" by a layer of tissue, which is known as the intimal flap.

A catheter angiogram showing an intimal flap (arrow) indicating dissection in an internal carotid artery. (Source: Suter B, El-Hakam LM. Child neurology: stroke due to nontraumatic intracranial dissection in a child. Neurology 2009; 72:e100.)
TREATMENT & PROGNOSIS

Lundqvist must rest and avoid any straining or twisting of the neck. He probably resumed light cardio exercise already, but must limit his neck motion and any possible contact to the neck.

The good news is that dissections heal on their own. In most cases, arteries with luminal irregularities caused by spontaneous dissection undergo recanalization (restoring normal flow) and healing in the first few months after the event (Liebeskind & Saver). Lundqvist will be re-evaluated and have follow-up imaging to determine the progress of his healing somewhere around the 4-week mark after the injury.

Most patients with a carotid dissection are placed on an anticoagulant (blood thinner), which I've discussed at length in my pieces on Rinne, Letang, and Vokoun. Patients will be placed on a 4-6 week regimen of the blood thinner, and due to an increased risk of bleeding (especially in a sport like hockey), athletes on anticoagulants aren't allowed to play. However, Lundqvist noted that he wasn't taking an anticoagulant but rather [daily] full-dose Aspirin, which does have [less-potent] anticoagulant properties and is relatively safe.

The main factor in Lundqvist's recovery is how fast his blood vessel can heal, and if he sticks to a strict regimen of rest to avoid potentially re-injuring himself. Yes, there is a small but definite risk of stroke, but in Lundqvist's case, it's great they caught the injury fairly early and he seems to be aware of the risk.



SOURCE:

Liebeskind, D & Saver, J.  Spontaneous cerebral and cervical artery dissection. In: UpToDate. Topic 14082 Version 16.0. Last Updated Feb. 10, 2015. UpToDate, Waltham, MA.

http://www.uptodate.com/contents/spontaneous-cerebral-and-cervical-artery-dissection-clinical-features-and-diagnosis

Friday, February 20, 2015

Injury Week in Review (Feb 14-20)

Hey all. This is the 2nd edition of Injury Week in Review. In these posts I'll be charting [new] injuries that occurred over the past week. These are only actual injuries (no illnesses/flu/missed games to personal reasons) that have caused players to miss 1+ game. Again, if I missed any, let me know!



Team
Player
Injury
Placed on IR?
Date of Injury
Projected Return & Notes
Stars
Tyler Seguin
Knee
Yes
Feb. 13
Up to 8 weeks
Stars
Ales Hemsky
Undisclosed lower body
No
Feb. 13
~1 week
Stars
Patrick Eaves
Concussion
Yes
Feb. 13
Week+, no skull fractures. Undergoing protocol
Senators
Chris Neil
Fractured left thumb
Yes
Feb. 14
3-4 weeks. Had surgery 2/19.
Ducks
Matt Beleskey
Undisclosed upper body
Yes
Feb. 15
2-4 weeks
Ducks
Sami Vatanen
Undisclosed lower body
Yes
Feb. 15
4-6 weeks, no surgery.
Sabres
Patrick Kaleta
Undisclosed “minor surgery”
Yes
Feb. 16
4-6 weeks
Jets
Mathieu Perreault
Undisclosed lower body
Yes
Feb. 16
“Significant” injury, possibly out rest of regular season  
Senators
Robin Lehner
Concussion
Yes
Feb. 16
Placed on IR 2/19. Out at least week+
Senators
Clarke MacArthur
Concussion
Yes
Feb. 16
Placed on IR 2/19. Out at least week+
Canucks
Christopher Tanev
Undisclosed
No
Feb. 16
Likely out until 2/27, didn’t travel with team for 5-game road trip.
Oilers
Luke Gazdic
Face
No
Feb. 16
Left 2/16 game after taking a hit from Dustin Byufglien. Missed 2/18 and 2/20 games.
Oilers
Viktor Fasth
Knee
Yes
Feb. 16
Out indefinitely after suffering knee injury on 2/16
Blue Jackets
Nick Foligno
Undisclosed lower body
No
Feb. 17
Missed 2/17 but returned to play 2/19
Islanders
Casey Cizikas
Undisclosed lower body
Yes
Feb. 16
Cizikas has been playing hurt, wears a boot on his boot after blocking a shot. Out a week, not seen to be too serious.
Predators
Anton Volchenkov
Undisclosed lower body
Yes
Feb. 14
Skated, likely to return soon
Canadiens
Alexei Emelin
Undisclosed upper body
No
Feb. 18
Day-to-day, out at least  a week. Possibly 4-6. (Right shoulder injury, no surgery)
Canadiens
Sergei Gonchar
Undisclosed upper body
Yes
Feb. 14
Left 2/14 game with an upper-body injury and placed on IR 2/19. Will likely return in a week.
Bruins
Kevan Miller
Shoulder
Yes
Feb. 16
Placed on IR 2/19. Concerns that “prognosis isn’t looking good”
Oilers
Anton Lander
Shoulder
Yes
Feb. 18
Placed on IR after suffering shoulder injury 2/18
Islanders
Mikhail Grabovski
Undisclosed upper body
Yes
Feb. 19
Took a huge hit to the head, probably his 2nd concussion of the season. Out at least a week+
Ducks
Hampus Lindholm
Ankle
No
Feb. 18
Day-to-day, missed 1 game (2/18)
Coyotes
Zybnek Michalek
Undisclosed upper body
No
Feb. 16
Day-to-day. Possible concussion. Missed 1 game (2/16) and will be out 2/21.
Sabres
Josh Gorges
Undisclosed lower body
No
Feb. 15
Out & chance it’s a season-ending injury
Flames
Paul Byron
Undisclosed lower body
No
Feb. 18
Day-to-day. Missed 2/18 and questionable for 2/20
Stars
Travis Moen
Undisclosed upper body
Yes
Feb. 17
Placed on IR and could miss “extended time”
Red Wings
Kyle Quincey
Undisclosed lower body
No
Feb. 20
Nursing a lower-body injury, doubtful for 2/21 game
Oilers
Jeff Petry
Ribs
No
Feb. 18
Left 2/18 game with ribs injury and will miss 2/20 game
Wild
Jared Spurgeon
Face
No
Feb. 18
Took a puck to the face 2/18 and will miss 2/20 game
Leafs
Trevor Smith
Undisclosed lower body
No
Feb. 16
Out through the weekend
Canucks
Alexander Edler
Undisclosed upper body
Yes
Feb. 14
Left 2/14 game in 2nd period with an upper-body injury. Placed on IR 2/18. Considered week-to-week
That's 31 injured players. 

Of note:

1. Tyler Seguin - It's been reported Seguin could miss up to 8 weeks due to a knee injury. The injury was due to a hit delivered by Panthers defenseman Dmitry Kulikov, who as a result was suspended for four games. The hit can be seen below, credit to u/goodaccount on r/hockey). 



2. Patrick Eaves - Another Stars player injured in the game against the Panthers. Eaves took a slapshot from his own teammate to the head and is out with a concussion. 


3. Chris Neil - If you need surgery, it's a fairly serious fracture. Probably a result of his fight with Luke Gazdic as seen below. 



4. Robin Lehner and Clarke MacArthur - The two Senators players collided into each other and both suffered concussions on a scary play which can be seen below (credit Adam Gretz, CBS Sports).


5. Luke Gazdic - Gazdic took a huge hit from Dustin Byufglien and needed 8 stitches (gfy credit to u/grizzy19 on r/hockey)




6. Mikhail Grabovski - Quite unfortunate, Grabovski took a huge (but clean) hit from Eric Nystrom on 2/19 and was down for a few minutes. He skated off on his own but missed the rest of the game and was immediately placed on Ir. This is probably Grabovski's second concussion of the season and is out indefinitely. GFY credit to u/fireislander on r/hockeygamegifs