title: Characteristics and prognosis of medial epicondylar fragmentation of the humerus in male junior tennis players.
abstract: BACKGROUND
  Although medial epicondylar fragmentation of the humerus is a reported elbow injury in junior tennis players, there have been only a few studies on this entity, and none have investigated the characteristics and prognosis of medial epicondylar fragmentation.
  
  
  METHODS
  Forty-one male junior tennis players, aged 11 to 14 years (mean, 13 years), underwent elbow examination by ultrasonography. Elbow re-examination was performed in subjects with medial epicondylar fragmentation at an average of 20 months (12-30 months) after the initial examination.
  
  
  RESULTS
  On examination, 9 subjects (22%) had elbow pain. Ultrasonography showed that 6 subjects (15%) had medial epicondylar fragmentation, all of whom had elbow pain. Medial epicondylar fragmentation was present in 5 (38%) of 13 subjects aged 11 to 12 years and in 1 (4%) of 28 aged 13 to 14 years. More subjects aged 11 to 12 years had medial epicondylar fragmentation (P = .0084). All 6 subjects with medial epicondylar fragmentation continued to play tennis between the initial elbow examination and the re-examination. At re-examination, although ultrasonography showed that 5 developed bone union and 1 had nonunion, 3 subjects (50%) reported elbow pain.
  
  
  CONCLUSIONS
  Our results demonstrated that subjects aged 11 to 12 years had a high frequency (38%) of medial epicondylar fragmentation. Although medial epicondylar fragmentation was the main cause of elbow pain (67%) at the initial elbow examination, all 6 players with medial epicondylar fragmentation continued to play tennis between the initial elbow examination and the re-examination. At re-examination, 5 subjects presented spontaneous bone union (83%), but 3 subjects (50%) reported elbow pain.
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Iida-Nishi, Japan. Electronic address: miharada@yoshioka-hp.or.jp.
authors.forename: Mikio
authors.initials: M
authors.lastname: Harada
authors.affiliation: Center for Hand, Elbow, and Sports Medicine, Izumi Orthopaedic Hospital, Sendai, Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Takahara
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Iida-Nishi, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Maruyama
authors.affiliation: Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Iida-Nishi, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Takagi
mesh_terms: D000293:Adolescent; D018771:Arthralgia / Q000209:etiology; D002648:Child; D004551:Elbow Joint / Q000000981:diagnostic imaging; D050723:Fractures, Bone / Q000000981:diagnostic imaging; D006801:Humans; D006811:Humerus / Q000000981:diagnostic imaging / Q000293:injuries*; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D013715:Tennis / Q000293:injuries*; D014463:Ultrasonography; D000092464:Elbow Injuries
keywords: Tennis; athlete; characteristic; elbow; medial epicondylar fragmentation; prognosis