Re-evaluating The Plantar Plate

In my opinion, the past ten years were the decade of the plantar plate. I’ve observed so much research and improvement in treating plantar plate deformities during this time. From an understanding of the function of the plantar plate to its common injury mechanics to the multitude of products to treat tears, options for injuries to the lesser metatarsophalangeal joint (MPJ) have dramatically improved. These advancements did not come without pitfalls, learning curves, and subtle pearls to make a good outcome be a great outcome. In this article, I will share my personal findings, pearls, and treatment options that I utilize for plantar plate injuries.

Anatomy And Presentation: What You Should Know

The plantar plate is the ligamentous structure that connects the neck of the metatarsal to the base of the proximal phalanx. The structure is approximately three to four mm in thickness with dense fibrous material. It is a ligament with significant strength, a wide attachment across the entire metatarsal neck and phalanx base, and stabilizes the toe from drifting medial or lateral and dorsal.^1-4

Plantar plate injuries can be acute or chronic. In my experience, most presenting patients have a chronic injury due to high-stress pressure associated with the involved MPJ. Most of these injuries I see are to the second MPJ, possibly due to a long second metatarsal, a second hammertoe deformity, a bunion deformity, or a combination thereof. Patients with a bunion deformity will have less pressure falling on the first MPJ, resulting in second MPJ overload.⁵ Patients with a hammertoe deformity will have retrograde pressure on the associated MPJ resulting in damage to the plantar plate.⁴ In my experience with chronic plantar plate damage, rarely will a patient not have an associated hammertoe, although this is possible in early cases.

Acute plantar plate injuries can occur in high-stress activities leading to hyperextension of the associated MPJ.⁶ In such cases, the toe will bend into extension resulting in a severe strain to the plantar plate and possible tear. Although rare, one must consider this etiology in patients with swelling and pain of the plantar MPJ after trauma.

Understanding Exam Pearls And Available Studies

I find examination of chronic and acute injuries are similar. From a dermatological standpoint, there is likely edema and erythema of the MPJ.⁷ One often notes a feeling of fullness at the injury site. Neurologically, I find patients may have some nerve pain in the intermetatarsal space and toe, which may mimic a neuroma. Although this pain may sometimes elicit a Mulder’s click, in my experience, careful examination will show more pain at the MPJ plantar surface than the interspace. Musculoskeletal examination may reveal pain in the MPJ. There is often an associated positive dorsal drawer test,⁷ which is essential to consider, as this does not occur with a neuroma.

I also find contracture of the associated toe common, however, I feel it is critical to evaluate any medial or lateral shift of the toe in chronic plantar plate injury cases. I find the second toe will shift medially and contract sagittally in these instances, while the third toe will shift medially or laterally along with the hammertoe deformity itself. In cases of medial shift of the second toe with hammering, it is essential to consider plantar plate damage as part of the underlying deformity and cause of pain. Although not necessarily painful, associated hallux valgus deformity and first ray instability must be a consideration during examination to allow comprehensive treatment planning. In individuals with severely hypermobile first rays, a Lapidus may be necessary, while in non-hypermobility cases of hallux valgus, one may consider bunion correction as an adjunct when electing surgical intervention.

One may choose to begin with standard radiographs for workup of plantar plate injuries. Although the plantar plate is not visible on plain X-ray, the structure of the foot and parabola of the metatarsals can provide useful information, in my opinion. The level of hammertoe deformity, medial or lateral shift of the toe at the MPJ, metatarsal length, and bunion deformity are all potential metrics to consider. Magnetic resonance imaging (MRI) is the mainstay of diagnostic tools in plantar plate analysis. In acute injuries, MRI will often reveal acute tears with associated fluid. In chronic injuries, fibrous scar formation can exist in addition to a tear.⁶ Checking for a neuroma on MRI is also a consideration when possible.

Conservative Care Considerations

Not all cases of plantar plate damage require surgical intervention. In cases without major toe contracture and minimal toe shift, conservative care may relieve pain. I find that in such cases, if the plantar plate is very unstable (a very lax toe with a positive dorsal drawer), conservative care is far more challenging, but otherwise, mild cases can do well with conservative options.

Conservatively, I divide my treatment arms into acute pain relief and chronic maintenance. In the acute setting, I will tape the toe in a plantarflexed position, begin topical anti-inflammatory treatments, place the patient in a stiff-soled shoe or boot, and limit activity for two to three weeks. This can calm down the MPJ, and physical therapy may assist in more rapid relief. After the acute phase is done and the patient has pain relief, I will begin a maintenance program that includes an orthotic with an MPJ cutout to relieve pressure on the damaged MPJ. I will also use a Morton’s extension on the orthotic if the first ray is not taking adequate pressure distribution. I also tell patients to tape the toe in a plantar position during activity with a strap or paper tape and wear stiff-soled shoes to limit dorsiflexion of the toe.

If acute pain does not subside, I have used platelet-rich plasma (PRP) and amniotic injections to aid repair. It is essential to alert patients that the deformity of the toe and MPJ will not change with these injections, but there may be some healing of the plantar plate that will make the MPJ more stable and reduce pain. With PRP and amniotic injections, I find two injections, spaced a month apart, are usually necessary. Additionally, it is important to tape the toe in a plantarflexed position and limit stress through the joint for ideal healing parameters after these types of injections. Both PRP

and amniotic injections aim to boost the body’s healing response to a chronically injured region with a helpful increase in inflammatory and healing cells.8 In acute plantar plate injuries without toe dislocation, taping and non-weight bearing casting for three weeks followed by protection in a boot with taping for an additional three weeks shows remarkable results in my practice.

Surgical Options To Consider For Plantar Plate Injuries

Surgical repairs of acute plantar plate injuries are rare but might be necessary for complete tears with toe dislocation or severe MPJ laxity on dorsal drawer. In such cases, primary repair through a plantar approach has been my go-to technique. I make an “L” incision in the interspace with the “L” portion at the phalanx base transversely. I then open the flexor sheath, and retract the flexor tendon. Then I can primarily repair the plantar plate with non-absorbing suture material. Rarely, suture anchors may be necessary to anchor the plantar plate into the base of the phalanx.

Chronic cases of plantar plate injury are far more common and problematic to treat. A complete forefoot plan is best in assessment and surgical treatment of chronic plantar plate injuries. I like to start from medial to lateral in my approach. If there is a bunion deformity, in most cases, I will addreas this. This will allow proper weight distribution across the ball of the foot and move the great toe into a neutral position, making room for the second toe. The ideal bunion surgery varies based on patient age, activity level, and hypermobility of the first ray. In general, an osteotomy will suffice, but a Lapidus may be necessary for larger bunions or hypermobile first rays. After bunion analysis and consideration, one can move on to the second MPJ and toe.

Many chronic tears of the plantar plate are in the second MPJ, and we will discuss this joint and its treatment options. Treatment of chronic tears of the third and fourth MPJ would be similar. In most cases, the MPJ plantar plate tear is partial and incomplete. Incomplete tears may be treated with a primary or secondary repair. I have done both and find each to have its advantages and disadvantages. I perform primary repair from a dorsal approach, and both a partial and complete plantar plate release and repair are possible. In most cases, I have begun to take a V-shaped wedge out of the lateral plantar plate tear and repairing the lateral plate with sutures into the phalanx base. I have found this to strengthen the plate, limit scar formation, and stiffness and work well. If the tear is more than 50 perform of the plantar plate insertion, I will do a full release of the plantar plate, take a small wedge out laterally to correct the medial shift, and do a complete repair to the phalanx base. In many cases, the tear may be more proximal under the metatarsal head, which may not allow for adequate repair with the existing systems. In such cases, I prefer to do a flexor tendon transfer to the base of the proximal phalanx through a secondary repair. Furthermore, if there is complete dislocation of the toe, I have found a flexor transfer to be far superior to primary repair as the quality of the plantar plate tissue is not sufficient for adequate repair. Finally, if there is significant medial or lateral shift of the toe at the MPJ, I have found I can control the toe’s position better with a flexor tendon transfer than a primary repair. Although flexor tendon transfers have been associated with MPJ stiffness, I have found them to be no stiffer than a primary repair and far more reproducible. My primary repairs are done with the Smith + Nephew HAT-TRICK lesser toe repair system, allowing partial or complete repair. It is an excellent system with a full array of tools. The patient may weight bear on the foot if other procedures do not preclude this and begin range of motion at two to three weeks, depending on the quality of the tissue repair. For flexor tendon transfers, a harvest of the long flexor is done at the hammertoe proximal interphalangeal joint region, and the tendon is split and pulled on the medial and lateral aspects of the proximal phalanx to the base of the toe. The tendon is then tensioned dorsally, making sure to protect the neurovascular structures, and is tied on the dorsal phalanx base near the MPJ. The farther the tendon is pulled close to the proximal phalanx base, the better the stability of the repair. I use a non-absorbable suture to repair the tendon and do not use a k-wire across the toe or MPJ. Instead, I begin range of motion at two to three weeks and stabilize the repair with strapping of the toe to stabilize it. The associated hammertoe deformity is corrected with a fusion and an internal implant. My preferred implant is an OSSIOfiber^® Hammertoe Fixation Implant, comprised of a biointegrative material. In most cases, I also perform a Weil metatarsal osteotomy as I find the second metatarsal to be long. One pearl to consider is a medial-shift Weil osteotomy. By shifting the metatarsal head proximal and medial, the toe relaxes at the MPJ, and also the medial shift moves the toe more lateral, correcting some of the deformity of the toe and medial shift of the toe. In many cases, the third and fourth toes may be medially shifted also due to the medial pull of the second toe. Although not as severe as the second toe, these toes may need to also be addressed. If the deformity is not severe and there is room for the second toe to be relocated, the third and fourth toes can be left alone. If the toes are medial and need correction, a Weil osteotomy with medial shift of the metatarsal head is very helpful. At times associated hammertoes should also be corrected, and, in some cases, I will imbricate and tighten the lateral capsule and collateral to get a subtle but helpful lateral shift of the toe at the MPJ. Finally, if there is a tailor’s bunion deformity also shifting the fifth toe medial, you may want to consider correction of that deformity in order to have a more neutral pull on the fifth toe and realignment of the forefoot as a whole, although this is not always necessary or wanted by the surgeon and/or the patient.

In Conclusion

As a whole, plantar plate care has evolved, but a great deal of improvement is still necessary for an ideal outcome. I find the medial and lateral shift of toes at the MPJ challenging to correct, especially with a primary repair of the plantar plate. I also find the stability of primary repairs sometimes inadequate due to the chronic damage to the plantar plate tissue or the location of the tear being in the more proximal tissue. I have begun to incorporate more flexor tendon transfers into my plantar plate repairs and found this technique to be an excellent option with reproducible results and solid outcomes. What has changed for me is that I no longer pin the hammertoe and MPJ with a K-wire and instead place an internal hammertoe implant and strap the MPJ in a rectus position. This allows early range of motion with flexor tendon transfers and has improved my issues with stiffness of the MPJ. With a complete and thorough workup and surgical decision-making process, plantar plate surgery can be a very effective and highly successful option for patient care and deformity correction. 

Dr. Baravarian is an Assistant Clinical Professor at the UCLA School of Medicine. He is the Director and Fellowship Director at the University Foot and Ankle Institute in Los Angeles (https://www.footankleinstitute. com/podiatrist/dr-bob-baravarian).

1. Gregg JM, Silberstein M, Schneider T, et al. Sonography of plantar plates in cadavers: correlation with MRI and histology. AJR Am J Roentgenol. 2006;186(4):948-955.

2. Gregg J, Marks P, Silberstein M, et al. Histologic anatomy of the lesser metatarsophalangeal joint plantar plate. Surg Radiol Anat. 2007;29(2):141-147.

3. Kirby KA. Understanding the biomechanics of plantar plate injuries. Podiatry Today. 2017;30(4):30-39.

4. Baravarian B, Thompson J, Nazarian D. Plantar plate tears: a review of the modified flexor tendon transfer repair for stabilization. Clin Pod Med Surg. 2011;28:57-68.

5. Espinosa N, Brodsky JW, Maceira E. Metatarsalgia. J Am Acad Orthop Surg. 2010;18(8):474- 485.

6. Linklater JM. Imaging of sports injuries in the foot. Am J Roentgenol. 2012;199(3):500- 508.

7. Klein EE, Weil Jr L, Weil Sr LS, Coughlin MJ, Knight J. Clinical examination of plantar plate abnormality: a diagnostic perspective. Foot Ankle Int. 2013;24(6):800-804.

8. Lee ET, Diller RB, Kellar RS. Platelet-rich plasma and amnion-derived fluid as clinical options for regenerative medicine applications. J Transl Sci. DOI: 10.15761/ JTS.1000204 . Published December 19, 2017. Accessed August 3, 2021.