Adequate data on the risks of a particular sport for an athlete with a medical problem are limited or lacking, and an estimate of risk becomes a necessary part of medical decision-making.

A. There are more than 3,000,000 annual sports-related injuries in the United States, and 65% are in the pediatric population.

B. In past legal decisions, athletes have been permitted to participate in sports despite known medical risks (AAP, 1994). When an athlete’s family disregards medical advice against participation, the physician should ask all parents or guardians to sign a written informed consent statement indicating that they have been advised of the potential dangers of participation and that they understand them. The physician should also document, with the child’s signature, that the child athlete also understands the risks of participation (AAP, 2001). Since 2001 there have been no updated American Academy of Pediatrics (AAP) recommendations.

A. Solitary Functioning Kidney

1. Typically has compensatory hypertrophy, thereby increasing the risk of injuring the kidney, because it is not as well protected by the ribs; the majority of solitary kidneys are right-sided, and the right kidney usually displaced inferiorly by the liver.

2. Renal agenesis: incidence as high as 1 in 1,000; male:female ratio 1.8:1; left side more commonly affected; contralateral vesicoureteral reflux in 20%.

3. Multicystic dysplastic kidney: nonfunctioning kidney with multiple cysts; incidence 1 in 1,000 to 1,500; contralateral renal abnormality in 20% to 30%, including vesicoureteral reflux and hydronephrosis; may involute and be mistaken for renal agenesis.

4. S/P (status post) nephrectomy for tumor (e.g., congenital mesoblastic nephroma, Wilms’ tumor, multilocular cystic nephroma, renal cell carcinoma) or nonfunctioning or poorly functioning kidney (ureteropelvic junction [UPJ] obstruction, ureterovesical junction obstruction, vesicoureteral reflux, renal vein thrombosis).

B. Hydronephrosis

1. Anomalous UPJ or UPJ obstruction

2. Ureterovesical junction obstruction

3. Vesicoureteral reflux

C. Anomalies of Renal Position

1. Horseshoe kidney: incidence 1 in 450; male:female ratio 2:1; most common renal fusion anomaly; isthmus inferior to inferior mesenteric artery; hydronephrosis common; unilateral multicystic dysplasia more common than in general population.

2. Other renal fusion anomalies: estimated incidence 1 in 1,000; male:female ratio 2:1; crossed fused ectopia, with or without renal fusion: left crossing to right side accounts for two-thirds of cases; sigmoid kidney, lump kidney, and disc kidney uncommon.

3. Renal ectopia: pelvic, lumbar; more common on left.

4. Renal transplant: pelvic position.

D. Abnormal Renal Size

1. Autosomal recessive polycystic kidney disease: survival beyond infancy uncommon, but kidneys are very large.

2. Autosomal dominant kidney disease: typically diagnosed in adulthood, but affected children typically have hypertension, proteinuria, and renal enlargement.

3. Angiomyolipoma associated with tuberous sclerosis; both kidneys typically affected.

E. Reduced Renal Function

1. Renal disease: glomerulonephritis, renal cystic disease.

2. Renal dysplasia: may or may not be associated with vesicoureteral reflux.

A. Prune belly syndrome: lax abdominal musculature predisposes to injury of solid abdominal organs as well as fluid-filled organs (e.g., bladder) from blunt trauma.

B. S/P augmentation cystoplasty or construction of urinary neobladder with continent diversion, for example, in children with bladder exstrophy, VATER (vertebrae, anus, trachea, esophagus, renal) syndrome, spina bifida.

A. Solitary Functioning Testis; Typically the Solitary Testis Exhibits Compensatory Hypertrophy

1. Secondary to in utero torsion; left side affected in two-thirds.

2. Secondary to postnatal testicular torsion; most common in adolescence.

3. Following removal of testicular tumor.

4. Following removal of testis from trauma.

5. Following unsuccessful orchiopexy.

B. Undescended Testis: Incidence 1 in 60 to 100

1. Unilateral: fertility typically nearly normal, most probably because unaffected testis is functioning normally.

2. Bilateral: fertility approximately 30% to 70%, in part because of impaired germ cell development, and in some cases because of intraoperative iatrogenic testicular or spermatic cord injury.

A. Classified Sports by Level of Contact

1. Collision or contact: in collision sports, athletes purposely hit or collide with each other or with inanimate objects, including the ground, with great force; in contact sports, athletes routinely make contact with each other or with inanimate objects, but usually with less force than in collision sports; include basketball, boxing, diving, field hockey, tackle football, ice hockey, lacrosse, martial arts, rodeo, rugby, ski jumping, soccer, team handball, water polo, wrestling.

2. Limited contact: contact with other athletes or inanimate objects is infrequent or inadvertent; includes baseball, bicycling (competitive bicycle racing not listed separately), cheerleading, canoeing or kayaking (white-water), fencing, field events (high jump, pole vault), floor hockey, flag football, gymnastics, handball, horseback riding, racquetball, skating (ice, in-line, roller), skiing (cross-country, downhill, water), snowboarding, softball, squash, ultimate Frisbee, volleyball, surfing, windsurfing.

3. Noncontact sports include all other sporting activities.

B. Kidney, Absence of One

1. “Qualified yes” for participation. “Athlete needs individual assessment for contact, collision, and limited-contact sports.”

C. Testicle, Undescended or Absence of One

1. “Yes” for participation. “Certain sports may require a protective cup.”