Current Insights On Treating Second MPJ Dysfunction

Author(s): 
Molly Judge, DPM, FACFAS

   In cases in which the second metatarsal is long or plantarflexed, and associated with chronic, well localized forefoot pain, then decompression of the MPJ should be the primary procedure. Repairing the primary stabilizing structure of the MPJ (the plantar plate) becomes a mandatory adjunct. If in fact we have the process backwards, we should be decompressing the MPJ as our first maneuver in the stepwise approach to MPJ dysfunction. This may make the routine practice of arthroplasty/arthrodesis nearly obsolete.

   Jolly and colleagues popularized the repair of the plantar plate and the procedure has received much attention in the literature ever since.5 Numerous authors have suggested variations in approach to this repair.6 Surgeons generally employ the technique in conjunction with a second metatarsal osteotomy. Weil Sr. and Weil Jr. provided a detailed review of their approach to MPJ pathology.7 They supported the repair of the plantar plate after completing successful shortening of the second metatarsal.

   While I was intrigued by the device the authors described for securing suture in repairing the plantar plate, it became apparent that this technique was not a simple one.7 The space available for the repair of the plantar plate is scant and even the most slender of fingers will be challenged by performing the required maneuvers. I have since developed a modified approach to stabilizing the plantar plate and have found it quite rewarding in the few patients in whom I have selected to use it.

   Before going into the details of this technique, I submit to you that most patients I evaluate and treat for MPJ pain and dysfunction recover from their symptoms and impairment very well with the benefit of digital stabilization and accommodative padding of the joint. I believe conservative methods can slow if not halt progressive lesser MPJ dysfunction. The key is in early identification of the condition and proper patient education.

Step-By-Step Pointers On Using The Suture And Button Technique

It bears mentioning that I prefer to avoid plantar approach incisions to this dissection as I think the hazards of that outweigh the benefit in the ease of exposure of the plantar plate.

   Make a dorsolinear incision. Start over the distal aspect of the second metatarsal and extend it onto the digit beyond the proximal phalanx base. Identify and isolate the second MPJ. One can subsequently perform a dorsolinear capsulotomy to expose the metatarsal head and proximal phalanx, and the chondral surface of the metatarsal head. Then begin a frontal plane osteotomy at the distal aspect of the dorsum of the anatomic neck of the metatarsal, and make a cut proximal and plantar, creating a long plantar wing.

   Translocate the metatarsal head proximally to achieve joint decompression. The metatarsal head will shift independently given the fact that its previously elongated condition loaded the metatarsal head and elevated the physiologic pressure there. The prevailing thinking is this intraarticular pressure causes the joint inflammation and chronic wear and tear that ultimately disrupts joint function, leading to symptoms. Surgical experience in osteotomizing a long second metatarsal demonstrates this phenomenon and underlines the importance of shortening the second metatarsal bone when attempting to correct MPJ dysfunction.

   With the metatarsal head disarticulated, it is easiest to evaluate the plantar plate from this dorsal approach. In my limited experience with this procedure, the plate itself is not usually deviated in a direction commensurate with the subluxation of the digit. Homologous to the relationship between the first metatarsal head and the sesamoid apparatus, it is the metatarsal head that seems to be shifted out of position.8 Once one has decompressed the joint, the realignment of the metatarsal osteotomy restores the anatomic relationship between the plantar plate and the metatarsal head.

Comments

Later this week, we'll be posting a follow-up blog from Molly Judge, DPM, FACFAS. Dr. Judge will expound upon the suture and button technique for plantar plate stabilization and share some questions on the technique from colleagues at a recent seminar.

Jeff A. Hall
Executive Editor
Podiatry Today

Is there results from the seminar yet?

I liked the direct approach your procedure takes to this pathology. My question is how the suture affects the extensor digitorum longus (EDL). Does the tension of the suture cause damage to the tendon? How do you get motion in the joint postoperatively with the tendon tied down with the suture?

The underlying biomechanical cause of many cases of 2nd MTP joint dysfunction is first ray inadequacy. Most patients in the earlier stages of 2nd MTP joint dysfunction can be treated with orthotics, not surgery. Hypermobile first ray, forefoot supinatus can be treated via a first metatarsal head cut out, forefoot valgus posting when appropriate and a metatarsal elevation in the device.

Yes, orthotics are often not covered by insurance and surgery is.

Dr. Davis,

I appreciate your input regarding 2nd MTPJ dysfunction. I agree with you wholeheartedly regarding the potential success of treating HAV with the benefit of orthotic devices. However, the 2nd MTPJ dysfunction has not responded equally well to that therapy. Once the instability has progressed and subtle subluxation and pain has developed, the need for an external splint and accommodative support of the MTPJ predictably provides pain reduction and stability to the affected joint. In my experience, stabilizing the 2nd MTPJ via metatarsal sling pad is far and away the best way to approach this lesser MTPJ instability and pain. The ADDED benefit of a formal orthotic device is an important one but doe not preclude the use of the metatarsal sling pad.

You make a valid point regarding the benefit of orthotic devices in the face of hallux abducto valgus and I agree with you that long-term management includes providing forefoot balancing. In my opinion, treating 2nd MTPJ dysfunction is a conservative issue by and large.

Unfortunately when patients are misdiagnosed, they often present to my office LATER having undergone numerous forms of treatment failures that include surgery. In my article, I emphasize the importance of the clinical and radiographic examination, and the need to exhaust conservative therapy. Only a few patients in my practice have ever required surgical intervention for this condition and I share that experience with the readers. The cases that I discuss in the cover story article on 2nd MTPJ dysfunction are the exception to the rule. In fact, the conservative method is very effective for 2nd MTPJ dysfunction in many cases.

Best regards,
Molly S. Judge, DPM

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