Flexor hallucis brevis muscle and tendon
Adductor hallucis muscle and tendon
Abductor hallucis muscle and tendon
Flexor hallucis longus insertion
Extensor hallucis longus insertion
Extensor hallucis brevis insertion
Pertinent Pearls On Treating First MPJ Injuries In Athletes
When the sesamoid remains painful, we end up performing sesamoidectomies six to 10 months after the injury. I prefer to keep athletes non-weightbearing for a minimum of six weeks with subsequent protection in a controlled ankle motion (CAM) walker for another six weeks. The rationale is simple: reduce the tension on the sesamoid fragments and plantar soft tissue attachments. Typically, many sesamoid fractures will either develop a nonunion, post-traumatic fibrosis and/or eventual arthrosis.
Unfortunately, the majority of us do not see sesamoid fractures acutely. We tend to see them months later. Either we see significant fracture gapping with chronic pain or we see them develop avascular necrosis. More often than not, we are forced to do a sesamoidectomy but in some patients who have developed arthrosis, we may be forced into a first MPJ fusion. So as with any injury, early diagnosis and treatment are keys to our success.
Keys To Diagnosing And Treating Sesamoid Apparatus Injuries
Sesamoid apparatus injuries are even harder to diagnose and treat. These are purely soft tissue in nature. When they are associated with first MPJ dislocation, these injuries are easy to predict. However, dislocations are infrequent. So we are left with injuries that seem minor but are debilitating to an athlete. They can be diagnostic challenges. It is critical to obtain a MRI to assess the collateral ligaments, flexor hallucis brevis (FHB), adductor, abductor, muscle and tendon attachments, and first IPJ and MPJ capsules. There are surgeons who have described soft tissue repairs of these structures but the effectiveness is questionable.
For most of us, determining the extent of the injury is more critical for determining how long we rest the athlete. Do we simply tape the toe? Restrict the motion? Stiffen up the shoe? Do we immobilize the foot completely? For many of us, seeing what athletes can do functionally will determine which approach to take. If athletes can not perform a single leg raise, we know they cannot return to the playing field.
Pertinent Pointers On Dislocations
Jahss was the first to classify first MPJ dislocations.15 As with any joint dislocation, we often see a myriad of injured structures. We may see a combination of soft tissue injury and fractures. Often, first MPJ dislocations can have sesamoid fractures, which often complicate the injury. We may see open dislocations less often. However, when we do see these, we will see significant soft tissue injury with either sesamoid or metatarsal fractures.16 All of this can lead to long-term sequelae.
Far too often, first IPJ and MPJ dislocations are reduced on the playing field or physicians reduce them in an emergency room setting. Failure to refer these athletes for further evaluation can lead to a premature return to play but what is more concerning is the development of joint instability or re-dislocation.
Many years ago, I had a soldier who dislocated his first IPJ. I performed an open reduction. I let him start running sooner than I probably should have. As a result, he proceeded to re-dislocate on two more occasions while playing basketball. He got to the point that he could dislocate his toe by simply adducting his hallux. He ended up needing a first IPJ fusion.
Orendurff and colleagues studied the foot pressures exerted during cutting, running and jumping.17 The hallux and first MPJ structures have to be stable to withstand push-off. The authors found the forces exerted on the joint are higher than once thought so it is no wonder athletes have so much difficulty getting back to competitive play and are prone to re-injury.