Medical Policy: 07.01.34
Original Effective Date: December 2006
Reviewed: July 2017
Revised: July 2017
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
Flatfoot (also known as pes planus) is often a complex disorder, with diverse symptoms and varying degrees of deformity and disability - with the common characteristic of partial or total collapse of the arch. Flexible flatfoot is one of the most common types, anatomically described as excessive pronation during weight bearing due to anterior and medial displacement of the talus. (The term flexible means the foot is flat when standing (weight-bearing) and the arch returns when not standing.) It may be congenital in nature, or may be acquired in adulthood due to posterior tibial tendon dysfunction.
Conservative treatments include orthotics or shoe modifications, stretching exercises and medication. Various surgical techniques of subtalar arthroereisis have been used in the treatment of patients who have failed conservative treatment.
Arthroereisis is the limitation of excessive movement across the joint. Subtalar arthroereisis is designed to correct the excessive talar displacement and calcaneal eversion by placing an implant in the sinus tarsi, a canal located between the talus and the calcaneus. Subtalar arthroereisis has been performed for a number of years, with a variety of implant designs and compositions. The Maxwell-Brancheau Arthroereisis (MBA) implant is currently favored due to the simple and reversible implantation procedure. The value of subtalar arthroereisis in the management and treatment of flatfoot deformity has not been established.
The HyProCure device (extra-osseous subtalar joint implant) from GraMedica is an implantable device indicated for the correction of talotarsal displacement. The device is inserted into the sinus tarsi and thereby reorientates the talocalcaneonavicular joint. The focus and primary diagnosis of the procedure is to properly realign and stabilize the talus of the tarsal mechanism, thereby restoring the talotarsal joint and talotarsal mechanism to normal function and triplane motion.
Other subtalar implants include:
2009 Guidance from the United Kingdom’s National Institute for Clinical Excellence concluded that current evidence on the safety and efficacy of sinus tarsi implant insertion for mobile flatfoot is inadequate in quality and quantity. Therefore this procedure should only be used with special arrangements for clinical governance, consent and audit, or research.
American College of Foot and Ankle Surgeons (ACFAS)
The ACFAS guideline on adult flatfoot states:
“In the adult, arthroereisis is seldom implemented as an isolated procedure. Because of the long-term compensation and adaptation of the foot and adjunctive structures for flatfoot function, other ancillary procedures are usually used for appropriate stabilization. Long-term results of arthroereisis in the adult flexible flatfoot patient have not been established. Some surgeons advise against the subtalar arthroereisis procedure because of the risks associated with implantation of a foreign material, the potential need for further surgery to remove the implant, and the limited capacity of the implant to stabilize the medial column sag directly.”
The ACFAS guideline on pediatric flatfoot states: “proponents of this procedure (arthroereisis) argue that it is a minimally invasive technique that does not distort the normal anatomy of the foot. Others have expressed concern about placing a permanent foreign body into a mobile segment of a child’s foot. The indication for this procedure remains controversial in the surgical community.”
Subtalar arthroereisis as a stand alone or in a combination surgical procedure, is considered investigational.
Data in the published medical literature are inadequate to permit scientific conclusions. One limitation of the published data is the lack of long-term outcomes, particularly important since the procedure is often performed in growing children. Another limitation is the lack of controlled studies comparing use of the implants with other surgical procedures (alone or in combination).
Currently there are not published control trials comparing talotarsal stabilization with extra-osseous subtalar joint implant and nonsurgical treatment or alternative surgical techniques. There are currently no randomized, prospective controlled studies that evaluate the safety and efficacy of subtalar arthroereisis in combination with other surgical procedures. Limitations of the published data is the lack of longterm outcomes, particularly important since the procedure is often performed in growing children, and the difficulty in separating the effect of this procedure from that of other adjunctive treatments. In addition, some publications report high rates of complications and implant removal. Extra-osseous subtalar joint implant is considered investigational.
Wellmark medical policies address the complex issue of technology assessment of new and emerging treatments, devices, drugs, etc. They are developed to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. Wellmark medical policies contain only a partial, general description of plan or program benefits and do not constitute a contract. Wellmark does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Wellmark or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. Our medical policies may be updated and therefore are subject to change without notice.
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