TREATING A PATIENT WITH THROMBOCYTOPENIA ABSENT RADIUS (TAR) SYNDROME - A F.U.N.CTIONAL APPROACH

Background & Purpose: Thrombocytopenia absent radius (TAR) syndrome is a rare genetic syndrome exemplified by the bilateral absence of radii even though thumbs are present. Platelet counts are also extremely low, characteristically below 50x10^9/L. Other orthopedic anomalies in the upper extremity and hand are possible, with lower extremity deformity present in about 47% of cases. In comparison to a typical thumb, patients with TAR syndrome maintain their thumbs in metacarpophalangeal flexion which can negatively impact function. Cardiac anomalies such as septal defects occur less than 40%, yet facial anomalies are present greater than 50% of the time.

Commonly, around age 3, an Ilizarov correction by an orthopedic surgeon is utilized to maximize upper extremity function. Prior to surgery, families are instructed on a stretching protocol with the addition of night splinting if possible. Data on the types of stretches or preferred type of splinting were not provided in the literature. Despite excellent overall outcomes of surgery to re-align and stabilize the wrist, post-operatively, patients are limited in wrist extension, ulnar deviation and have an overall reduced range of motion in all digits.

This case report serves to add to the literature for pediatric physical therapists working with a patient with a TAR syndrome diagnosis. Employing a F.U.Nctional approach (F = faciliatory techniques, U= upper extremity splinting, N= nonsurgical) helped to maximize upper and lower extremity function, while maintaining the family’s preference to avoid surgery.

Case Description: LB is a 22-month-old female with a diagnosis of TAR Syndrome. She has been receiving early intervention physical therapy services since she was 4 months old with other services discontinued due to frequent hospitalizations. Once LB was medically stable, interventions focused on modifications to improve upper extremity function and generalized strengthening of all extremities and trunk to promote gross motor skill acquisition. Anti-radial drift thumb spica splints have been applied overnight in 12-hour increments intermittently since LB was 7 months old.

Outcomes: Within the first year of treatment, several functional milestones previously thought to be unattainable were achieved. This includes self-feeding with utensils, emergence of pincer grasp, pulling to stand, cruising and, more recently, modified creeping on flexed elbows. Most importantly, LBs family reports increased capability for facilitating LBs independence in self-care and gross motor development.

Discussion: This case study illustrates functional improvements made by a patient with TAR syndrome. Emphasis was placed on F.U.N.ction: a combination of faciliatory techniques, splinting and respecting the family’s decision not to pursue surgery. Although this success may not be broadly applied to all patients with TAR syndrome or other limb deficiencies, this case study adds to the paucity of evidence for this population. Additional research regarding non-surgical management for patients with TAR syndrome is warranted.