Key words: Bilateral little-finger deformity, mallet finger, clinodactyly, volleyball sport injury, physis injury, hand pain.

Volleyball is one of the most popular team sports and presents several possible mechanisms for injury to the player. Common volleyball injuries have been described at length in recent years (Bahr and Bahr, 1997; Bahr and Reeser, 2003). Most injuries to volleyball players occur in the lower extremities, particularly the foot and ankle. Although injuries to the hand and wrist are common in volleyball players, most go unreported (Briner and Kacmar, 1997). Among the injuries to the hands, fingers are involved in almost half of the cases. Sprains or strains are the most common type of injury (Bhairo and Nijsten, 1992), and epiphysial injuries of the hand are less common. The epiphysis of the distal phalanges begins to ossify at 12 to 36 months of age and closes at approximately 13 to l6 years (Hensinger, 1986). Prior to closure of the epiphysis, fractures (Salter-Harris type I or II) usually occur through the growth plate or through the juxtaepiphyseal region 1 to 2 mm distal to the growth plate. The extensor tendon inserts into the epiphysis only, whereas the flexor digitorum profundus inserts into the metaphysis or spans both the epiphysis and the metaphysis (Al-Qattan, 1998). Because of the asymmetry of these tendon insertions, the clinical manifestation of this injury in the young mimics a mallet finger and a clinodactyly deformity. A flexion deformity is the result of a Salter-Harris type II injury, whereas a valgus deformity of the distal phalanges is the result of a Salter-Harris type V injury on the radial side of the physis.

A 14-year-old male high school student who had played volleyball for 3 years presented with a complaint of right- and left-hand little-finger flexion, valgus deformity (Figure 1), and pain. These symptoms began during his second season of competitive play. His role was a setter and passer on the team. The patient initially complained of pain in the distal phalanges of the little fingers, but he continued to play. As he continued to compete, he began to note the onset of flexion and a valgus deformity of the distal interphalangeal (DIP) joints. Plain radiographs and a hand examination were performed, and the flexion and valgus deformity were obvious on plain radiographs as well as on his clinic examination. A bilateral little-finger distal phalanx base epiphysis injury was seen. This injury is characterized by a biplanar Salter-Harris physial injury, type V on anteroposterior radiographs and type II on lateral plain radiographs (Figure 2). The wrist, hand, and other fingers were normal. As the pain persisted, he was provided with bilateral little-finger splints. Control plain radiographs were taken with finger splints and the patient was instructed to abstain from play until physial closure.

This was an unusual case related to a volleyball injury. Particular injuries are seen in young volleyball players. Compared with other sports (handball, soccer, basketball, and badminton), volleyball players have a higher frequency of injuries to the hands, fingers, and ankles, but fewer injuries located in other anatomical regions (Solgard et al., 1995). It is highly significant that school/educational players have more hand and finger injuries than do club players (Solgard et al., 1995). Our case was a school volleyball player. As most of the injuries are the result of acute trauma, repeated long-term injuries are seen rarely. The hand and finger injuries occur during contact with the ball in the overhand pass position, and only a few occur while blocking or spiking. High-level club players incur noncontact injuries during jumping, and young players are generally injured by contact with the ball, mostly during overhand passing. In this case, the little-finger physeal injuries were thought to have occurred as a result of repeated trauma by contact with the ball during overhand passing, resulting in a Salter- Harris type V injury on the anteroposterior planes and a Salter Harris type II injury on the lateral planes. Thus, a flexion and valgus deformity occurred in the little-finger DIP joints. We had to exclude the possibility that this was a result of direct trauma to the upper extremities, which may cause vascular injuries leading to ischemia of the hand and fingers such as hypothenar hammer syndrome (Reekers and Koedam, 1998; Marie et al., 2007). In this case, the pathology was bilateral, and the patient examination did not support hypothenar hammer syndrome. Angiography must be performed to exclude microemboli in the digital arteries of the hand. This fracture pattern also mimics Saymours' fracture, but it is caused by direct trauma to the distal phalanges physis, resulting in an open fracture. There is usually a transverse laceration of the nail matrix, with the base of the nail itself extruding out from under the nail fold (Seymour, 1966). Premature closure of the epiphysis secondary to infection rather than direct injury to the growth plate was excluded (Engber and Clancy, 1978). We observed no infection or signs of premature epiphyseal closure in this case.

• As a result of repeated micro traumas to the physial region, flexion and valgus deformities of the distal interphalangeal (DIP) joints should be occurred.
• Sports injuries to the hand often require treatment in orthopedic departments to avoid permanent deformities.
• Short- or long-term functional results can be gained by simple splinting procedures and abstention from play.