Past precedent: How many months will Zach Collins miss?

We don’t know how many games Zach Collins will miss as he recovers from surgery to repair a torn labrum caused by a dislocated shoulder. The Trail Blazers organization has been mum on the topic so far, preferring to wait until after surgery to provide a possible recovery date.

Collins is far from the first player to require surgery to repair damage caused by a dislocated shoulder. Let’s take a look at how well others recovered and how much time they needed to return to play (RTP).

What happened to Zach Collins?

I am not a doctor, so here’s Joshua Dines, an orthopedic surgeon, to fill us in (emphasis mine):

The shoulder is a ball-and-socket joint. Shoulder instability (or shoulder dislocation) occurs when the humerus (or ball part of the shoulder) is forced out of the socket (glenoid).

...

For the shoulder to dislocate, typically one of three things (or a combination of the three) has to occur: the rotator cuff tendon can tear, a piece of the socket can break off, and/or the labrum can tear. Labral tearing is the most common cause of instability in the shoulder. The labrum is a soft tissue structure that goes around the socket like a bumper goes around a pool table.

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Surgery is usually done arthroscopically through small poke holes in the skin. A camera is utilized to view inside the joint, and the labrum is sutured back to the socket using anchors in the bone.

How long did it take other players to get back on the court?

I found two good sources detailing how long it took for other NBA players to return from a surgery to repair damage caused by a dislocated shoulder.

The first article from Jeff Stotts at In Street Clothes cataloged eight players who needed surgery — several had labral tears while others had unspecified damage. Mean return time was 32 games.

However, 32 games might be a tad optimistic. All but two of those surgeries either ended a player’s season or occurred during the offseason, thereby decreasing the number of games a player with an early-season injury might miss.

Jameer Nelson and Kyle Weaver were the only two to have the surgery in-season and return that year. They missed 54 and 43 games, respectively. And saying Nelson “returned” is a bit generous — he gutted out some minutes during the Finals but was ineffective.

The other source I found is an academic article published in the Journal of Shoulder and Elbow Surgery. Lu et al. document 36 cases of shoulder dislocations in NBA players between 1999-2018. Of those, 22 required surgery and had a mean RTP of 16.5 weeks. This estimate, however, is also likely complicated by season-ending and off-season surgeries, as mentioned above.

Interestingly, centers accounted for 12 of the 25 (48%) surgical cases Lu et al. documented (22 shoulder dislocations, 3 subluxations).

The tl;dr here is that prior precedent suggests recovery from a shoulder surgery to repair damage caused by dislocation is a multi-month process often causing players to miss dozens of games.

Can we get more exact data on recovery time?

In the interest of better understanding the effect that offseason recovery had on missed games, I took the list compiled by Jeff Stotts and ran some google searches for details on other players to try to better understand how long players took to recover.

Here are the data:

Note that this isn’t everyone, but, unfortunately, I can’t dedicate entire days to Internet sleuthing NBA injuries. If you know of other players who suffered a shoulder dislocation and surgery let me know in the comments and I’ll try to add the info.

This table shows that a more conservative RTP average is about 5.5 months (24ish weeks). It’s also worth noting that nearly every player had an estimate recovery timeline of “4 months” or “4-6 months” immediately following surgery.

Will Zach Collins be able to fully recover?

Lu et al. have some good news about the long-term prognosis of players who undergo shoulder surgeries. The authors found no difference between the players who recovered from surgery and healthy controls on PER, career length, or All-star appearances. Further, only two of the 22 players who underwent surgery after a dislocation had a second dislocation or separation. Five of 14 players who did not under go surgery had a second injury.

When will Zach Collins be back on the court?

Conventional wisdom and the journal article agree: players who undergo shoulder surgery after a dislocation generally have positive outcomes and are less likely to have a second injury. That’s great news for Collins and the Blazers! If history is any indication, there’s a very good chance he’ll be able to make a full recovery.

The bad news is that, depending on your methodology, players have needed an average of 16.5 to 24 weeks to recover from this type of surgery. That would put Collins back somewhere between mid-March and the end of the regular season. Only one player, Kyle Weaver, successfully returned in less than four months. That’d be early March for those keeping score at home.

Of course, the extent and severity of Zach’s injury aren’t really known so these guidelines may not perfectly align with his recovery. But past data do support Dwight Jaynes’ claim that Collins’ recovery will be measured in months and not weeks. The big question now is whether or not he’ll be ready for the playoffs.

Miscellaneous

I don’t have enough for a full article, but I stumbled across an interesting stat and wanted to share: distance traveled by players is increasing.

It’s hard to find reliable data prior to the 2000s, but there is one article published in 1994 that estimated players ran 2.1 miles per game (plus 1000 steps walking). The average today hovers around 2.6 miles. If the 1994 calculation is accurate, it’s possible average distance traveled has been slowly ticking up for over 20 years. Finding additional reliable data points would be fascinating.