WRIST DISORDERS IN THE YOUNG ATHLETE

Transcription

1 WRIST DISORDERS IN THE YOUNG ATHLETE PETER G. GERBINO, II, MD In the young athlete, forced dorsiflexion causes most wrist injuries. Sudden dorsiflexion from a fall onto the outstretched hand results in fractures, ligament tears, and joint disruptions. Repetitive dorsiflexion, which occurs in activities such as weightlifting or gymnastics, leads to overuse injuries including physeal stress fractures, bone stress fractures, triangular fibrocartilage complex tears, impingement syndromes, progressive laxity and arthritic degeneration. Wrist braces have not been successful in preventing fractures. Wrist taping or bracing is inadequate to prevent wrist overuse injuries in gymnasts. Treatment of wrist injuries involves rest, splinting or casting, and both open and arthroscopic surgical techniques. KEY WORDS: young athlete, wrist injuries, gymnast's wrist, dorsal impaction, TFCC Traumatic or repetitive dorsiflexion and impact loading is responsible for 90% of wrist injuries. ~ Traumatic wrist dorsiflexion injury most often occurs from a fall onto the outstretched hand. 2 Overuse dorsiflexion injuries are most common in gymnasts and weightlifters. In children, between 35% 3 and 41%4 of all fractures occur in the wrist and distal forearm. Six percent of fractures involve the physeal cartilage and, fortunately, most are Salter-Harris I or II with excellent prognosis. 5 Trying to tease out nonfracture wrist injury numbers is a bit more difficult because wrist injuries have commonly been combined with hand injuries. Despite this, several studies confirm that the number of injuries occurring to the young athlete's wrist and hand is higher now than in any other area The growing popularity of in-line skating has added to the number of wrist injuries. Estimates by the United States Consumer Product Safety Commission National Electronic Injury Surveillance System were that 40,730 in-line skating injuries occurred to children in 1992 and Of these, 66% were forearm and wrist fractures, n Majetschak et al found that 51.5% of in-line skating injuries were distal radius fractures, n and Mitts and Hennrikus found that 75% of childrens' flactures from in-line skating occurred as a result of a fall on the outstretched hand. ~3 This same pattern was been previously reported for skateboarding injuries. 14 ANATOMY The distal forearm and wrist comprise the eight carpal bones and the distal radius and ulna. Each bone has multiple articulations and ligament attachments. The nonligamentous soft tissues include the flexor and extensor tendons as well as the arteries, veins, and nerves. From the Department of Orthopaedic Surgery, Harvard Medical School, Division of Sports Medicine, Children's Hospital, Boston. Address reprint requests to Peter G. Gerbino, II, MD, Department of Orthopaedic Surgery, Children's Hospital, 300 Longwood Avenue, Boston, MA Copyright 1998 by W.B. Saunders Company /98/ /0 Of particular importance in the growing athlete are the appearance of ossific centers and the closure of the physes. The carpal bones begin to ossify at 6 months (capitate and hamate) to 6 years (trapezoid). All are completely ossified by 18 years of age. The distal radial epiphysis appears at 1 year and the distal ulna epiphysis appears at 5-7 years. The distal radius and ulna physes are closed by years of age. 15 The distal radial physis contributes 75% of radius length and 39% of total upper extremity length16; radial physeal arrest can lead to painful positive ulnar variance The relative strengths of the wrist structures are responsible for the injury patterns observed. Physeal cartilage is weak in shear or tension, failing at the cellular hypertrophyprovisional calcification boundary. 2 This zone of weakness, when compared with ligament strengths, accounts for the small number of purely ligamentous injuries in this population. In compression, bone fails first, yielding the classic buckle fracture. Repetitive compression or tension loads lead to less-easily predicted injury patterns. Stress fractures of bone are rare in the wrist, while fatigue failure of physeal cartilage, articular cartilage, and ligamentous structures is more common. The triangular fibrocartilage complex (TFCC) is a special structure at the ulno-carpal articulation. It consists of the triangular fibrocartilage disc and the ulnocarpal ligament complex. A meniscal structure may or may not be found within the TFCC. Functionally, the TFCC extends the radio-carpal articulation, permitting pronation and supination. 21 The distal radio-ulnar joint (DRUJ) has a precise mechanism, and injuries that disrupt the joint's ligaments or change the alignment between articular surfaces can lead to loss of forearm rotation. Other wrist ligaments include radiocarpal and carpal-carpal attachments. These can be injured in dislocations or, as recently observed, become pathologically lax in certain individuals. 22 They may also be the sites of painful ganglia. The common dorsal wrist ganglion develops most often in the scapholunate ligament. 23 Tendons and nerves around the wrist can be injured by direct trauma or overuse. Tendinitis occurs in the flexor and extensor tendons. Carpal tunnel syndrome is a rare Operative Techniques h7 Sports Medicine, Vol 6, No 4 (October), 1998: pp

2 occurrence in adolescence. Anatomic vascular malformations can cause wrist pain, as can neoplasms, infections, and arthritic conditions. OPERATIVE APPROACHES TO THE WRIST The anatomy of the wrist provides several safe approaches to the dorsal and palmar structures. Arthroscopic techniques have permitted access to virtually every anatomic structure around the wrist. The open approaches include the dorsal and palmar approaches to the wrist and the dorsal and palmar approaches to the scaphoid. These are described in standard reference texts~ 24 Arthroscopy of the wrist is an evolving skill with several well-established portals described and the possibility of putting a portal virtually anywhere one would want to work. The three most used portals are the 3-4 portal, the 4-5 portal and the 6-R portal. The 3-4 site is located dorsally between the third and fourth dorsal compartments, 1 cm distal to Lister's tubercle. The 4-5 portal is located between the fourth and fifth dorsal compartments and gives excellent access to the TFCC. The 6-R portal is just radial to the extensor carpi ulnaris (ECU) tendon. Other common portals are the 6-ulnar, midcarpal radial, midcarpai ulnar, and proximal and distal carpal tunnel portals on the palmar side (Fig 1). In a typical operative arrangement, the fingers are placed in finger traps and a 2.7 mm videoarthroscope is used. Pediatric wrist arthroscopy adds the additional challenge of small size, but advances such as the hand tower (Fig 2) and smaller instruments allow the experienced surgeon to safely operate on children. 4-5 BIOMECHANICS The wrist is a compound joint, which permits movement in three planes that results in dorsiflexion, palmar flexion, radial deviation, ulnar deviation, pronation, and supination. In flexion movements, the carpus moves relative to the distal radius and TFCC. A small amount of intracarpal flexion occurs as well. Radial and ulnar deviation occurs through carpal-carpal as well as radiocarpal articulations. The DRUJ is the primary site for forearm rotation. The radius and carpus rotate about the ulna 25 with the ligaments of the TFCC tightening in pronation and unwinding in supination. 26 To understand how pathological forces about the wrist result in acute dislocation patterns, Mayfield 27 has described four controlling factors. First, the radial side ligaments are weakest. Second, the radiocapitate ligament is taut in extension and ulnar deviation. Third, the proximal carpal row is stabilized by five ligaments, and the distal row is stabilized by only one. Fourth, the radiocapitate ligament is the weakest link between the forearm and distal carpal row. In the young athlete, the adult types of wrist dislocation can occur, but these ligament tears and resultant instabilities are rare. 28 More common in adolescents is a progressive loss of carpal stability from preexisting laxity combined with repetitive hyperextension. 22 Inaris Fig 1. Standard arthroscopic portals of the dorsum of the wrist. The 3-4, 4-5 and 6-R portals are most frequently used. (Reprinted with permission. 63) EVALUATION History History includes circumstances of the injury, mechanism of injury, previous injuries, medical history, family histor34 hand dominance, and loss of sensation or motion of the hand and wrist. Physical Examination Inspection of the injured wrist can reveal swelling, deformity, or changes in skin coloring. Palpating for tenderness localizes the area(s) of injury. Range of motion about the wrist is examined for 6 degrees of freedom: dorsiflexion, palmar flexion, radial deviation, ulnar deviation, pronation, and supination. Neurovascular status is evaluated, and pain and strength during grip are assessed. Three provocative tests include the Watson test for scapho-lunate instability (Fig 3), 29 ballottement or intercarpal shuck test 198 PETER G. GERBINO, II

3 Fig 4. Shuck test for lunate-triquetral instability. Painful motion with palmar translation of the pisiform and triquetrum indicates instability. Fig 2. The hand tower permits controlled distraction forces while.= presenting the wrist conveniently to the to the wrist arthroscopist. Fig,'3. Watson's test for scapho-lunate instability. The scaphoid tubercle is palpated as the wrist is moved from radial deviation 'to ulnar deviation. A painful clunk as the scaphoid reduces indicates instability. WRIST DISORDERS IN THE YOUNG ATHLETE "~99

4 Fig 5. DRUJ grind test for DRUJ pain and chondromalacia. The examiner compresses the proximal forearm loading the DRUJ. Pain or crepitus at the DRUJ with forearm rotation indicates pathology. for lunate-triquetral instability (Fig 4), 30 and the DRUJ grind test for painful crepitus (Fig 5). 21 As previously discussed, the radial and ulnar physes are more likely than the ligaments to be injured. Before concluding that the athlete has sustained a ligamentous or TFCC injury, the examiner must be certain that the physes or bones are not the source of pain. Imaging Common wrist radiographic views are anterior-posterior (A-P), lateral, and oblique. These views are appropriate following trauma to evaluate bone structure and alignment. The A-P in ulnar deviation (scaphoid) view can uncover some scaphoid fractures that might otherwise be missed and a clenched fist view can reveal scapho-lunate dissociation. Other imaging studies include tomograms, computerized tomography (CT), magnetic resonance imaging (MRI), technetium-99m bone scans, and triple injection wrist arthrograms. The indications for each of these studies are evolving, but MRI has become the most frequently used second study. Occult fractures, ligament injuries, TFCC tears, and even physeal fractures can be detected by a single MRI study without the ionizing radiation of the other studies. Injecting the radiocarpal joint with contrast medium and observing leakage into the DRUJ remains the most certain nonoperative means of detecting TFCC disruption (Fig 6). Brown et al, 31 however, have reported a 51% incidence of asymptomatic TFCC perforations. The arthrogram is incapable of determining the type of tear. duplicate that work. The basic principles of distal forearm fracture care merit review. A fall on the outstretched hand in an adult commonly produces a Colles' fracture. In a child, a torus fracture of the radius, a both-bones greenstick fracture of the forearm, or a Salter-Harris fracture through the distal radial physis is more likely to occur. A typical fracture in the athletic adolescent is an apex palmar, radial metaphysis fracture with plastic deformation of the ulna and possible disruption of the DRUJ. The predominant fracture patterns are age-dependent, but there is considerable overlap among age groups and treatment principles are the same. Nonsurgical treatment is appropriate for torus fractures that are more common in athletes age 12 years or younger. Minimal SPECIFIC WRIST PROBLEMS IN THE YOUNG ATHLETE Distal Forearm Fractures Several excellent texts describe the detailed care of children's fractures. 32,33 The intent of this article is not to 200 Fig 6. Wrist arthrography with injection into the radiocarpal joint space (white arrow). Leakage into the DRUJ (black arrow) indicates TFCC tear, PETER G. GERBINO, II

5 cortical buckles are splinted and those with angulation greater than 10 are reduced and placed in a molded long-arm cast if the child is age 5 or younger, and a molded sho~:t-arm cast if the athlete is older. 32 Greenstick and displaced both-bones fractures are reduced and held in a long-arm cast with interosseous and three-point molds. 33 These fractures are notorious for displacing if inadequate casting is done, and weekly radiographs are necessary for the first 2 weeks. Healing is usually complete at 6 weeks. When the distal radius is fractured and the ulna is intact, the DRUJ must be carefully examined. If the DRUJ is intact, reducing the radial fragment requires straightening the plastically deformed ulna. When the DRUJ is disrupted, the radius must be adequately reduced so that normal DRUJ mechanics are restored. A well-molded long-arm cast in supination will often be adequate, but the surgeon should not hesitate to stabilize the DRUJ with a pin. Open fracture, acute carpal tunnel syndrome, multiple upper extremity fractures, loss of correction in an appropriate cast, shortening of the radius or ulna, and inability to achieve a stable reduction are indications to stabilize a distal forearm fracture operatively. Fixation options include K-wires, plating, external fixation, or intramedullary rodding. Most authors believe that 20 of fracture angulation in the more mature patient must be adjusted. 32,33 Ensuring that DRUJ alignment is restored and ulnar variance matches the contralateral side is most important. Salter-Harris (S-H) fractures of the wrist usually involve the distal radial pjc~ysis. S-H I fractures are treated with 2 to 4 weeks of short-arm casting until tenderness is resolved. Nondisplaced S-H II fractures can be treated for 4 weeks in a long-arm cast with repeat radiographs for the first 2 weeks and a short-arm cast for an additional 2 weeks. Intra-articular fractures require reduction with no more tha~. 1 to 2 mm of displacement or step-off. Inability to achieve or maintain reduction warrants operative treatment. In the young athlete with open physes, smooth K-wires are used to stabilize the fragments. An external fixator spanning the wrist is frequently necessary to supplement the pins. To ensure anatomic restoration of articular surfaces, reduction guided by arthroscopic or open joint surface visualization can be employed. Dorsal Impaction Conditions Gymnasts and cheerleaders use the wrist as a weightbearing joint. Weightlifters also load the wrist with excessive weight. These repetitive loads can lead to several overuse conditions, including radial physeal injury (gymnast's wrist), 34 radius and ulna stress fractures, arthritic changes, TFCC tears, stress fractures of the scaphoid, and avascular necrosis of the capitate. 35 Collectively, these syndromes are described as dorsal impaction conditions. All are believed to occur as a result of repetitive dorsiflexion with axial loading. Repetitive trauma to the radial physis can lead to partial or complete closura and wrist deformity. Several authors have documented distal radius deformity resulting from partial physeal closure in gymnasts When the entire radial physis is injured, premature complete closure or retarded radial growth can occur, leading to positive ulnar variance. There is evidence that gymnasts have an increased incidence of positive ulnar variance, 17,18,39 but cause and effect have not been proven. Caine et a137 critically analyzed 25 articles in the literature written on the relationship between gymnastics and radial growth. They concluded that the current literature supports the "... plausibility of stress-related distal-radius physeal arrest with secondary positive URLD (ulna radial length difference)." They found circumstantial evidence for a dose-response relationship between amount of training and development of positive ulnar variance. Treatment of a distal radial physis stress fracture includes rest and immobilization in a short-arm cast for 6 weeks or until the wrist is nontender. Significant deformity is rare, but the patient and family should be aware of the potential for growth arrest requiring operative treatment. Authors have postulated that poor technique, 4 poor coaching, 41 use of the dowel grip, 42,43 and tumbling on mats that are either too soft 44 or too hard 45 are additional risk factors for developing radial physeal injury. Until more rigorous studies are conducted, the amount of time spent in practice and the number of years in gymnastics are the only risk factors that seem to be significant. 37 What the optimal amount, duration, or intensity level of training should be remains to be learned. Training techniques that limit the amount, intensity, and frequency of wrist dorsiflexion should decrease the number of injuries. Early detection by frequent wrist examination will decrease morbidity and hasten return to competition. Injuries to the TFCC Fractures about the wrist and repeated dorsal impaction can both lead to TFCC damage. Diagnosis is made by palpation distal to the ulnar styloid. Grinding the TFCC can produce a painful click. MRI is improving as a diagnostic tool and arthrography with cineradiography remains the nonsurgical diagnostic study of choice, but arthroscopy is the best means of assessing TFCC damage. 46 Palmer 47 has developed a classification system for these tears (Fig 7) and consensus is growing about which tears need to be repaired and which can be debrided or treated closed. Some 1A tears can heal if immobilized for 4 weeks in slight palmar flexion and ulnar deviation48; other 1A lesions require arthroscopic debridement. 49 Palmer 1B, 1C, and 1D tears require arthroscopic or open repair. 5 Because the articular disc has better vascularity in children, 5~ repair should be considered more frequently than in adults. Recently, Terry and Waters 52 reviewed 29 pediatric and adolescent TFCC tears. They recommended debridement of Palmer 1A lesions and repair of 1B, 1C, and 1D tears. Surgical goals are to eliminate unstable, impinging flaps of tissue and restore supportive ligamentous structures. Scaphoid Injuries The scaphoid is fractured from a fall on the dorsiflexed hand and is the most common carpal fracture, s3 Four aspects of scaphoid fractures are unusual, but if they are remembered, few unsatisfactory results will occur. A fractured scaphoid may not be painful enough to cause the athlete to seek care. This results in many late diagnoses of scaphoid nonunion. Scaphoid nonunion left untreated leads to degenerative arthritis of the wrist. 54 Even when WRIST DISORDERS IIN THE YOUNG ATHLETE 201

6 1A 1B 1l,!, \ ) lc 1D il Lunate ~Triqueri"m B Fig 7. Palmer classification for TFCC tears. Acute traumatic and newly symptomatic tears can be classified as 1A, 1B, 1C, or 1D. Chronic degenerative tears are best described as type 2A, 2B, 2C, or 2D lesions. IG ~ Radius l at c j painful enough to cause the athlete to seek care, initial radiographs may not show a fracture. When fracture occurs, healing time is long because the scaphoid has a relatively poor blood supply and the fragments are difficult to anatomically reduce and immobilize. A patient with tenderness in the anatomic snuff box, at the scaphoid tubercle, or with a positive axial scaphoid compression test is treated for a scaphoid fracture even if the radiographs appear normal. MRI is best to find an occult fracture acutely (if necessary) and CT or tomograms best demonstrate cortical bridging at the fracture site. Healing following cast treatment averages 12 weeks, but may take longer. 55 A short-arm thumb spica cast is preferred by most, but some still favor the long-arm cast.2,10,32,33,48,53,55 The indications for open reduction and internal fixation of scaphoid fractures are evolving. Any displacement or angulation requires fixation and some feel that nondisplaced scaphoid fractures heal faster with Herbert screw fixation. 56 The extensive dorsal or palmar exposure needed to place the Herbert screw has been greatly reduced by arthroscopic techniques that now exist to place a cannulated Herbert or Herbert-Whipple screw. 57 Scaphoid nonunions pose a different problem for the sports medicine physician. They are usually discovered in the middle of the season, when operative repair and bone grafting would take the athlete out of athletics for several months. Knowing that the natural history of untreated nonunions predicts a poor outcome, the timing of the operation becomes the issue rather than whether or not to 202 PETER G. GERBINO, II

7 treat. Most athletes can safely play the remainder of the season in a soft thumb spica cast. Surgical repair using autogenous bone graft, with or without Herbert screw fixai~on, is performed thereafter. The scaphoid can also develop a stress fracture or a dorsal ridge impingement from repetitive wrist dorsiflexion. Stress fractures are diagnosed by physical examination indicating scaphoid tenderness. Without a history of macrotrauma, a bone scan or MRI can be obtained to confirm the diagnosis of stress fracture. The fracture is immobilized in a short-arm thumb spica cast for 8 to 12 weeks or until tenderness resolves. Scaphoid impaction syndrome occurs in gymnasts and weightlifters. 5s The athlete complains of pain and is tender dorsally at the radio-scaphoid joint. A bone scan may show evidence of arthritis, but initial studies are negative. Prior to the development of osteophytes, treatment requires a cessation of dorsiflexion activities, with or without casting. OTHER WRIST PROBLEMS IN THE YOUNG ATHLETE Distal forearm fractures, TFCC tears, and scaphoid injuries account for the majority of wrist problems in adolescents. Any of the other carpal bones can be fractured, and ligament tears, sub;~uxations, and dislocations occur. These other injuries are more common in adults and, when found in adolescents, are treated similarly. Likewise, ligament laxity, tendinitis, carpal tunnel syndrome, and wrist ganglions occur in adolescents and are treated no differently than in adults. Scapholunate instability can be treated with capsulodesis, stabilizing the distal pole of the scaphoid using a bone sutu~:e anchor (Fig 8). A baseball player or golfer with pain in the ulnar palm should be evaluated for a hook of the hamate fracture, which can occur when the butt end of the bat or club is held in the palm rather than kept below the hands. 59 Other sources of wrist pain in the young athlete include arthritis, infection, neoplasms, and avascular necrosis. Kienbock's Disease or avascular necrosis of the lunate is a particularly difficult problem with no uniformly accepted etiology and no uniformly accepted treatment. In general, the goals are to reduce pain, promote healing, and maintain motion. Triscaphoid arthrodesis is sometimes necessary to relieve pain. 29 PREVENTION While wrist guards for in-line skaters decrease the frequency of fractures, 6 they are not sufficient to prevent fractures. In a cadaver studj6 Giacobetti et a161 showed that wrist fractures and carpal injuries occur despite the use of standard wrist guards. Most injuries occur in novice skaters. Simply by putting on the wrist guards prior to standing up with the skates on, some fractures will be prevented. The best prevention is to wear wrist guards and minimize falls by skating in control and skating in areas free of stones and other imperfections. Overuse injuries in gymnasts can best be prevented by keeping training demands rational and by early detection and treatment. The use of wrist taping in gymnastics, Fig 8. Radiograph showing suture anchor in distal pole of the scaphoid following capsulodesis procedure for scapholunate instability. K-wires stabilize the scaphoid to the lunate, capitate, and radius. weightlifting, and football is common. The tape is a (minimal) physical block to both extreme hyperextension and hyperflexion (Fig 9), but a recent study found that wrist taping actually decreases grip strength. 62 "Lion's paws" and other splints used by gymnasts also restrict dorsiflexion, but all too frequently taping or splinting is used only after injury has occurred. SUMMARY Wrist problems in young athletes are commonly due to dorsiflexion trauma and dorsiflexion overuse. Traumatic injuries are mostly distal forearm and scaphoid fractures and overuse injuries are predominately distal radial physis stress fractures and TFCC tears. Fractures about the wrist can occur in any sport, but in-line skating is particularly risky. Overuse problems occur mainly in gymnasts, cheerleaders and weightlifters. Progressive wrist laxity is becoming more common as gymnasts train harder. Nonsurgical means can be used initially to treat most wrist problems. When surgery is necessary, arthroscopic techniques have improved results and lowered morbidity. WRIST DISORDERS IN THE YOUNG ATHLETE 203

8 Fig 9. Classic taping procedure for gymnasts spans the joint to restrict both dorsal and palmar flexion. A fist is made or the fingers spread vigorously while the tape is applied. This permits tight wrapping while avoiding vascular constriction. REFERENCES 1. Lincheid RL, Dobyns JH, Beabout JW, et al: Traumatic instability of the wrist. Diagnosis, classification and pathomechanics. J Bone Joint Surg Am 54: , Van Herpe L: Fractures of the forearm and wrist. Orthop Clin North Am 7: , Crawford AH: Pitfalls and complications of fractures of the distal radius and ulna in childhood. Hand Clinics 4: , Mann DC, Rajmaira S: Distribution of physeal and non-physeal fractures in 2650 long-bone fractures in children aged 0-16 years. J Pediatr Orthop 10: , Larsen E, Vittas D, Torp-Pedersen S: Remodeling of angulated distal forearm fractures in children. Clin Orthop 237: , Zariczny B, Shattuck LJ, Mast TA, et al: Sports-related injuries in school-aged children. Am J Sports Med 5: , Backx FJ, Erich BM, Kemper AB, et al: Sports injuries in school-aged children: An epidemiologic study. Am J Sports Med 17: , Chambers RB: Orthopaedic injuries in athletes (ages 6-17). Am J Sports Med 7: , Garrick JG, Requa RK: Injuries in high school sports. Pediatrics 61: , Hastings HH, Simmons BP: Hand fractures in children: A statistical analysis. Clin Orthop 188: , NEISS Estimate Reports. Estimates for Washington, DC, US Consumer Product Safety Commission: National Injury Information Clearinghouse, Majetschak M, Kock HJ, Neudeck F, et al: Causation and injury pattern in in-line skating. Unfallchirurg 23: , Mitts KG, Hennrikus WL: In-line skating fractures in children. J Pediatr Orthop 16: , Schmid A, Rotzscher V: Patterns of injuries in skateboarding accidents. Unfallchirurg 96: , Greulich WW, Pyle Sh Radiographic Atlas of Skeletal Development of the Hand and Wrist (ed 2). Stanford, CA, Stanford University Press, Prichett JW: Growth plate activity in the upper extremity. Clin Orthop Rel Res 268: , DeSmet L, Claessens A, Lefevre J, et ah Gymnast wrist: An epidemiologic survey of ulnar variance and stress changes of the radial physis in elite female gymnasts. Am J Sports Med 22: , DiFiori JP, Puffer JC, Mandelbaum BR: Distal radial growth plate injury and positive ulnar variance in nonelite gymnasts. Am J Sports Med 25: , Montgomery KD, Hunter A, Waters P: The management of distal radial growth arrest in adolescents. Presented at the 52nd annual meeting of The American Society for Surgery of the Hand, Denver, CO, September 11-13, Salter RB, Harris R: Injuries involving the epiphyseal plate. J Bone Joint Surg Am 45: , Palmer AK, Werner FW: The triangular fibrocartilage complex of the wrist--anatomy and function. J Hand Surg Am 6: , Waters PM: Personal communication, December, Saunders WE: The occult dorsal carpal ganglion. J Hand Surg [Br] 10: , Hoppenfeld S, deboer P: Surgical Exposures in Orthopaedics (ed 2). Philadelphia, PA, Lippincott, 1994, pp Palmer AK, Werner FW: Biomechanics of the distal radioulnar joint. Clin Orthop 187:26-35, Bowers WH: The distal radioulnar joint, in Green DP (ed): Operative Hand Surgery (ed 2). NY, Churchill Livingstone, 1988, pp Mayfield JK: Mechanism of carpal injuries. Clin Orthop 149:45-54, Gerard FM: Post-traumatic carpal instability in a young child. J Bone Joint Surg Am 62: , Watson HK, Hempton RF: Limited wrist arthrodesis: The triscaphoid joint. J Hand Surg [Am] 5: , Reagan DS, Linscheid RL, Dobyns JH: Lunotriquetral sprains. J Hand Surg [Am] 9: , Brown JA, Jansen DL, Alder BD, et al: Arthrography of the contralateral asymptomatic wrist in patients with unilateral wrist pain. Can Assoc Radiol J 45: , Kasser JR: Forearm fractures, in MacEwen GD, Kasser JR, Heinrich ST (eds): Pediatric Fractures. A practical approach to Assessment and Treatment. Baltimore, MD, Williams & Wilkins, Rang M: Childrens' Fractures (ed 2). Philadelphia, PA, Lippincott, 1983, pp Dobyns JH, Gabel GT: Gymnast's wrist. Hand Clin 6: , Dobyns JH, Simm FH, Linscheid RL: Sports stress syndromes of the hand and wrist. Am J Sports Med 6: , Albanese SA, Palmer AK, Kerr DR, et al: Wrist pain and distal growth plate closure of the radius in gymnasts. J Pediatr Orthop 9:23-28, Caine D, Roy S, Singer KM, et al: Stress changes of the distal radial growth plate. A radiologic survey and review of the literature. Am J Sports Med 20: , Vender MI, Watson HK: Acquired Madelung-like deformity in a gymnast. J Hand Surg [Am] 13:19-21, Mandelbaum BR, Bartolozzi AR, Davis CA, et al: Wrist pain syndrome in the gymnast. Am J Sports Med 17: , Read MTF: Stress fractures in the distal radius in adolescent gymnasts. Br J Sports Med 15: , PETER G. GERBINO, II

9 41. Micheli LJ: Pediatric and adolescent sports injuries: Recent trends. Exerc Sports Sci Rev 14: , Ruggles DL, Peterson HA, Scott SG: Radial growth plate injury in a female gymnast. Med Sci Sports Exerc 23: , Yong-Hing K, Wedge JH, Bower CV: Chronic injury to the distal ulnar and radial growth p]ates in an adolescent gymnast. I Bone Joint Surg Am 70: , Roy S, Caine D, Singer KM: Stress changes in the distal radial epiphysis in young gymnasts. A report of twenty-one cases and a review of the literature. Am J Sports Med 13: , Lishen Q, Jianhua O: Epiphyseal injury in gymnasts. Clin J Sports Med (China) 2:7-12, Schers TJ, vanheusden HA: Evaluation of chronic wrist pain. Arthroscopy superior to arthrography: Comparison in 39 patients. Acta Orthop Scand 66: , Palmer AK: Triangular fibrocartilage complex lesions: A classification. J Hand Surg [Am] 14: , Richards RS, Roth JH: Common wrist injuries, in Cahn KM (ed): Sports Injuries of the Hand and Upper Extremity. NY, Churchill Livingstone, 1995, pp Gan BS, Richards RS, Roth JH: Arthroscopic treatment of triangular fibrocartilage tears. Orthop Clin North Am 26: , Skie MC, Mekhail AO, Deitrich DR, et al: Operative technique for inside-out repair of the triangular fibrocartilage complex. J Hand Surg [Am] 22: , Mikic Z: The blood supply of the human distal radioulnar joint and the microvasculature of its articular disk. Clin Orthop 275:19-28, Terry CL, Waters PM: Triangular fibrocartilage complex in pediatric and adolescent patients. Presented at the 51st annual meeting of The American Society for Surgery of the Hand, Memphis, TN, September 30-October 3, Cooney WB, Dobyns JH, Linscheid RL: Fractures of the scaphoid: A rational approach to management. Clin Orthop 149:90-97, Ruby LK, Stinson J, Belsky MR: Tlle natural history of scaphoid nonunion. J Bone Joint Surg Am 67: , Stewart MJ: Fractures of the carpal navicular (scaphoid): A report of 436 cases. J Bone Joint Surg Am 36: , Koman LA, Mooney JF, Poehling GG: Fractures and Iigamentous injuries of the wrist. Hand Clin 6: , Whipple TL: Wrist arthroscopy and clinical applications of wrist arthroscopy, in Lichtman DM (ed): The Wrist and Its Disorders. Philadelphia, PA, Saunders, 1988, p Linscheid RL, Dobyns JH: Athletic injuries of tile wrist. Clin Orthop 198: , Stark HH, Jobe FW, Boyes JH, et al: Fracture of the hook of the hamate in athletes. J Bone Joint Surg Am 59: , Thompson RS, Rivara FP: Protective equipment for in-line skaters. N Engl J Med 335: , Giacobetti FB, Sharkey PF, Bos-Giacobetti MA, et al: Biomechanical analysis of the effectiveness of in-line skating wrist guards for preventing wrist fractures. Am J Sports Med 25: , Rettig AC, Stube KS, Shelboume KD: Effects of finger and wrist taping on grip strength. Am J Sports Med 25:96-98, Poehling GG: Wrist arthroscopy, in An Illustrated Guide to Small Joint Arthroscopy. Andover, MA, Dyonics, Inc, 1989, p 8 WRIST DISORDERS IN THE YOUNG ATHLETE 205