How To Handle Second MTPJ Stress Syndrome
Second MTPJ stress syndrome has become a catch-all term for patients who complain of chronic pain involving the second MTPJ. While it is important to differentiate this entity from a neuroma, intermetatarsal bursitis or a stress fracture of a metatarsal, it is even more important for the practitioner to determine an accurate etiology or etiologies for the second MTPJ stress syndrome. Only by understanding the cause of the problem can one develop an effective treatment plan.
When a patient has second MTPJ stress syndrome, he or she may have the following typical signs and symptoms:
• pain with pressure to the second MTPJ;
• a positive modified Lachman’s test (manual subluxation of the MTPJ that creates pain);
• pain in the sub-second metatarsal head with standing and/or ambulation;
• pain with the second MTPJ area that is well localized;
• edema of the second MTPJ area;
• painful second hammertoe (flexible or rigid depending on the amount of time since the onset of symptoms);
• possible dorsal dislocation of the second digit at the MTPJ;
• possible adduction (splaying) of the second digit when the foot is loaded;
• possible hyperkeratotic lesion of the sub-second metatarsal head;
• hallux abductus with bunion deformity, which may be symptomatic; and/or
• a hypermobile first ray with abnormal pronation.
The longer the problem has been present, the more digital deformity one will usually see. Possible etiologies of second MTPJ stress syndrome include:
• chronic overload of the second MTPJ which may be due to hypermobility of the first ray, longstanding hallux abductus with bunion deformity, negative metatarsal protrusion distance or chronic digital deformity;
What You Should Consider In The Diagnostic Workup
Anatomical considerations for second MTPJ stress syndrome include rupture of the plantar plate, rupture of the MTPJ ligaments or a combination of the two ruptures. Other considerations include an abnormally long second metatarsal or an iatrogenic short first metatarsal.
In evaluating a patient with a painful second MTPJ area, one should initially rule out other possibilities for pain in that area. For example, while a neuroma in the second interspace can occur, it is certainly a rarity. Injecting a local anesthetic into the second interspace should be able to provide insight as to whether the symptoms are the result of nerve entrapment. However, in most cases, the pain is so well localized to the second MTPJ without distal paresthesias that one should be able to rule out a nerve problem just by clinical examination.
Obtaining X-rays of the involved area will rule out the possibility of a metatarsal stress fracture. The X-rays will also reveal whether there is a short first metatarsal (perhaps from a prior surgery), a long second metatarsal or the signs of a hypermobile first ray.