NBA injury guru Jeff Stotts checks in on the key injuries around the league impacting Fantasy leagues.

Sixers guard Markelle Fultz remains out indefinitely, though a name has finally been given to his mysterious shoulder ailment. After multiple meetings with shoulder specialists, Fultz has been diagnosed with Thoracic Outlet Syndrome (TOS).

The thoracic outlet region is formed by the first rib, the collarbone, and the surrounding musculature. A bundle of nerves runs through this narrow passageway along with arteries and veins. TOS is a collection of issues that result when these structures become pinched or impinged in three possible locations. Multiple reasons for an impingement in the thoracic outlet region also exist including anatomical variation present from birth. These defects include having an extra rib in the area or an elongated cervical vertebra. Repetitive motion and trauma can also lead to TOS with symptoms that may be slow to develop.

TOS is a relatively common in Major League Baseball, especially for pitchers. Matt Harvey, Josh Beckett, and Phil Hughes all missed time in recent seasons due to TOS-related issues. However, the condition is seemingly rare in basketball.

Treatment is often dictated by the type of structure being pinched. Fultz's case is being described as neurogenic TOS, meaning it involves the nerves. Symptoms from this type of TOS can include weakened grip strength, headaches, numbness and tingling into the extremity. It can also result in muscle fatigue and, in some prolonged cases, muscle atrophy and diminished fine motor skills.

Conservative (non-operative) treatment is often preferred though surgery may be necessary if the symptoms persist after therapy. Congenital defects, like the presence of an extra rib, are often surgically removed. Unfortunately, a number of complications can arise following surgical intervention though those rates appear to be linked to the surgeon and their adopted approach.

Fultz is attempting to avoid surgery and opting to focus on physical rehabilitation. The Sixers originally stated he would be re-evaluated in 3-6 weeks but an end does not currently seem in sight. Fantasy owners invested in Fultz would be wise to explore other options moving forward. The situation remains unpredictable and outweighs any potential productivity. Even a trade out of Philadelphia wouldn't guarantee a resolution to his problems, making him a Fantasy liability.

Rookie Luka Doncic has excelled for the surprising Mavericks, averaging 18.4 points, 6.7 rebounds and 4.9 assists. Unfortunately, a lingering wrist injury for starting point guard Dennis Smith Jr. has cost Doncic valuable time alongside his backcourt mate.

Smith originally sprained his right wrist in a loss to the Grizzlies on Nov. 19 but managed to play in the Mavericks' next game. However, pain and soreness from the injury persisted and he was in street clothes for the subsequent contest. A month later, the injury remains an issue and is accompanied by an audible crackling sound. As a result, Smith has been unavailable for six of Dallas' last eight games.

Determining the exact problem is difficult due to the complexity of the wrist. The joint complex is comprised of the distal ends of the radius and ulna as well as the eight carpal bones. These uniquely shaped bones articulate with each other and are attached by an intricate network of ligaments. These ligaments provide stability for the area and help anchor the tendons of the hand in place. The ligaments on the pinky side of the wrist are fortified by the triangular fibrocartilage complex (TFCC), an articular cartilage disc.

Injuries to any of these structures would result in pain and functional limitation as well as the clicking sound Smith is currently reporting. The team offered a sliver of insight into the injury by classifying it as a sprain. The term sprain is reserved for any injury that involves one or more ligaments of the body. Unfortunately narrowing the problem down much further is difficult as the location or the exact name of the affected ligament has not been revealed.

Most wrist sprains are treated by immobilization and rest. Unfortunately, the healing process is a delicate and easily disrupted. Coach Rick Carlisle acknowledged that part of Smith's issue is linked to the point guard repeatedly falling on the wrist. If the injury site is aggravated whenever Smith falls on an outstretched hand then the normal healing response is negatively impacted and potentially forced to restart. This results in prolonged symptoms and an extended recovery process. Altering his style of play and avoiding explosive drives to the basket could help preserve the wrist but would fundamentally change who Smith is as a player.

For now, the Mavericks will continue to treat Smith's wrist conservatively and continue to utilize rookie Jalen Brunson as their starting point guard. J.J. Barea, fresh off a two-game absence for an ankle sprain, will remain the lead guard with Dallas' second unit. The veteran point guard currently holds more Fantasy weight than Brunson and is a decent source of assists in deeper leagues.

Fast Breaks

DeMarcus Cousins: The Warriors' marquee acquisition is nearing his debut as Cousins continues to work his way back from last season's Achilles tear. The All-Star center has spent time with Golden State's G-League team and is reportedly progressing nicely. Achilles injuries can be career-altering injuries, so expecting Cousins to return to an elite level may be asking a bit much. However, he could still end up being a Fantasy-friendly option if you missed out on a top-rated center like Anthony Davis or Joel Embiid. The Warriors will likely limit his minutes upon his return, but this may be the last shot to add or acquire Cousins in all formats.

Zach LaVine: The former dunk contest winner remains out with a sprained ankle, though his injury varies from the "garden variety" ankle sprain. Ankle sprains that most commonly occur in basketball are known as lateral or inversion ankle sprains. This injury occurs when the foot is forced inward, injuring the ankles on the outer aspect of the joint. LaVine's injury involves the deltoid ligament, a triangular shaped ligament situated on the inner aspect of the foot. The deltoid complex is surprisingly strong and can result an avulsion fracture when stressed. However, LaVine's injury has been classified as a simple sprain of the area though a return to play timeline remains unknown. Fantasy owners should anticipate LaVine sitting for another two weeks, at least, as the Bulls revealed Wednesday morning.

Paul Millsap: The Nuggets expect Millsap to miss 4-6 weeks after the former All-Star suffered a broken big toe. While the big toe may seem like an insignificant digit, it is an important part of the foot, especially during weight bearing. Studies have shown the big toe often absorbs up to 80 percent of the body's weight while walking and as much as 10 times that much when jumping. Look for Millsap's return to be on the latter end of that estimation.

Jonas Valanciunas: The big man will miss an extended period of time after dislocating his thumb. The force required to misalign the joint resulted in ligament damage that ultimately required surgery to mend. The last player to require surgery following a thumb dislocation was guard Jodie Meeks and he missed 26 games, as a result. With that in mind, an early February return seems likely, making the center a candidate to be dropped in standard formats.