Plantar Plate Insufficiency or Rupture (Turf Toe)

Anatomy

• During normal gait, MTPJ has to sustain more than 40 to 60% off bodyweight, during normal athletic activities this increases to 2-3 times the bodyweight. During running jump MTPJ sustains eight times the body weight.
• Metatarsophalangeal joint (MTPJ) is statically stabilised by the plantar plate and the collateral ligaments.
• Dynamic stability for the first MTPJ is provided by the short flexor complex, which is composed of medial and lateral bellies of flexor hallucis brevis, adductor hallucis and abductor hallucis muscles and the medial and lateral sesamoid bones and their ligaments.
• Plantar plate is the trapezoid shaped thickening of the MTPJ capsule at the weight bearing plantar aspect.
• It is a fibrocartilaginous structure that resists hyperextension and provides stability to the MTPJ.
• It is the major stabiliser of the MTPJ.
• It provides a smooth gliding surface for the flexor tendons inferiorly and metatarsal head superiorly.
• Proximally it is inserted into the metatarsal neck.
• Distally to the base of proximal phalanx by medial and lateral longitudinal bundles.
• It receives attachment from collateral ligaments, deep transverse metatarsal ligaments and vertical fibers of plantar aponeurosis.

Pathology

• Degenerative or traumatic rupture of plantar plate is an under-recognised cause of metatarsalgia.
• Degenerative rupture of plantar plate especially in the second MTPJ can lead to metatarsalgia with synovitis, which if untreated progresses to hammer-toe, claw-toe or crossover-toe deformity.
• In 2/3rd of cases the second toe is commonly involved as it tis the longest.
• Long term use of high heel foot wear may be a cause in older women as it causes chronic
• Lesions can cause metatarsalgia, instability, deformity and dislocation.
• Deformity may be in the sagittal plane such as hammertoe and claw toe or coronal plane such as crossover toe..
• During the heel-off and toe-off of stance phase of gait, the MTPJ becomes dorsiflexed. Dorsiflexion is passively resisted by the plantar plate and actively by the intrinsic musculature.
• With insufficiency of plantar plate, dorsal subluxation of MTPJ occurs. The interossei is displaced dorsally leading to hyperextension of MTPJ. The medially located lumbrical causes adduction deformity. Attenuation of collateral ligaments also contributed to the development of coronal plane deformity.
• Majority of cases have an insidious onset and is seen in sedentary older women.
• It can be seen in young athletic males after trauma.
• It can also be seen as a secondary deformity in association with hallux valgus, hallux varus, pes planus and hallux rigidus.
• The term Turf Toe introduced by Bowers and Martin in 1976 for injuries of the plantar plate of first metatarsophalangeal joint (MTPJ) of great toe seen in athletes playing on artificial turfs using lighter and flexible shoes.
• Coughlin coined the term ‘second crossover toe’ in 1987 to describe the coronal plane deformity.
• Hyper-dorsiflexion of the MTPJ is the most common mechanism of injury.
• Causes distractive forces on the plantar plate, sesamoid complex and toe flexors.
• In the big toe, the plantar plate rupture occurs distal to the sesamoids.
• Rarely tissue disruption occurs through the sesamoids producing sesamoid fracture.
• Injury may be partial or complete. It may extend to the collateral ligaments in presence of varus or valgus moment.
• Hyper-plantarflexion injury is called Sand Toe as it is common in beach volleyball.

To read the complete article

https://learningorthopaedics.com/plantar-plate-insufficiency-or-rupture-turf-toe/