Current Concepts In Plantar Plate Repair
We also have an ongoing study looking at diagnostic ultrasound in comparison to MRI findings and intraoperative findings. The early results from this study suggest that ultrasound evaluation of the plantar plate is highly technician dependent. Although the ability of the ultrasound and technician to detect the presence of plantar plate pathology is relatively high (75 percent), the ability to accurately detect the location of the plantar plate pathology is very low (31 percent).
A Guide To Performing The Combined Plantar Plate Repair And Weil Osteotomy
To rectify plantar plate pathology and metatarsal deformity, we have developed a combined procedure to perform a dorsal approach anatomic plantar plate repair and a Weil osteotomy.
Make a linear incision overlying the extensor apparatus extending from the distal third of the metatarsal shaft to the midshaft of the proximal phalanx centering over the MPJ. After performing dissection down to the extensor apparatus, create an incision between the extensor digitorum longus and brevis to the level of bone from the distal metatarsal to the proximal phalanx shaft. Place a self-retaining retractor deep to the extensor tendons and expose the MPJ. Reflect the medial and lateral collaterals off the proximal phalanx base, making sure to preserve their metatarsal head attachments.
Then carefully place a small or medium McGlamry type elevator into the MPJ and advance it proximally (hugging the bone) to release adhesions and mobilize the proximal plantar plate attachment at the metatarsal neck. This allows improved exposure to the plantar plate in later steps. Only use the elevator plantarly and do not carry it to the medial or lateral side of the metatarsal head. This helps maintain collateral attachments as these attachments provide the most important blood supply to the metatarsal head.
Perform a Weil osteotomy in the affected metatarsal. The osteotomy starts in the dorsal (2 to 3 mm) articular surface of the metatarsal. The angle of the osteotomy is as close to parallel to the weightbearing surface as possible. This angle is important to prevent plantar displacement of the metatarsal head as one creates shortening.
After completing the osteotomy, use a metatarsal pushing device to push the metatarsal head proximally 7 to 15 mm and temporarily fixate it with a 1.6-mm threaded K-wire.
Place a mini-joint distraction device over the pin to fixate the metatarsal head and then place a second pin from dorsal to plantar, 5 mm distal to the base of the proximal phalanx. After placing the distractor, open it to gain dorsal access to the MPJ and visualize the plantar plate.
One can confirm plantar plate pathology with direct visualization of this structure. We have observed several different types of plantar plate injuries. These injuries include attenuation/attrition, longitudinal buttonhole tears, partial transverse tears or complete ruptures (see the table “What A Cadaveric Study Reveals About Plantar Plate Pathology” above). The most common pattern, in cadavers and our patients alike, is the incomplete transverse tears at the attachment into the proximal phalanx. These tears can be visible at the medial plantar plate attachment or, more commonly, the lateral plantar plate attachment. With more advanced disease, the entire plantar plate will be torn. Coughlin and colleagues published an anatomic study of plantar plate tears and a modified version of our grading scale.12,16