USA Gymnastics estimates that nearly 3 million recreational athletes and 85,000 competitive gymnasts participate in gymnastics each year in the United States (1). Gymnasts range from the young child involved in tumbling exercises to the elite gymnast training for competitions such as the Olympics. Elite gymnasts may initiate training as early as 4 or 5 yr of age and quickly accelerate the difficulty and intensity of their training (2). The average elite female gymnast trains 5.36 d each week and 5.04 h each day (3) and may peak at 50 h each week (2). Exposure-based injury rates for club-level female gymnasts range from 1.4-3.7 injuries per 1000 h (4). According to a prospective study on injuries in a female NCAA Division I gymnastics team, each player had 151.4 exposures, with an injury in approximately 7% of all exposures (5). Overall, there is a 25-fold higher rate of injury in the highest level of the United States Gymnastic Federation compared with the lowest level of competition (2).
The number of injuries has been shown to increase until the middle of the season, when they plateau (5). A study of elite Swedish gymnasts with an injury rate of 6.25 per 100 gymnasts per season shows that the majority of injuries affect the lower extremities and occur mostly from mounting and dismounting. Male gymnasts sustained the most severe injuries such as fractures and dislocations, and the majority of these occur in the upper extremities (6). Overall, acute injuries are 10 times more likely during competition than practice (2,7).
The upper extremities are used for weight-bearing in gymnastics, unlike most other sports. Given the high impact loads across the upper extremities, it is the second most frequently injured body region (4). The wrist is the most frequently injured site in the upper extremity of female gymnasts followed by the elbow. Male gymnasts most frequently injure the shoulder followed by the wrist in the upper extremity. The wrist is exposed to many different types of stresses including repetitive motion, high impact loading, axial compression, torsional forces, and distraction (8). Combining these forces with varying degrees of ulnar and radial deviation and hyperextension predisposes the wrist to higher rates of injury during gymnastics (9). Wrist pain among high level club and collegiate gymnasts is 46%and 79%, respectively (10,11). According to Dobyns and Gables, up to 88% of gymnasts experience wrist pain (12). Wrist pain is associated with older age, increased training hours per week, training at a higher skill level, and the initiation of training at an older age (8). Elite gymnasts have greater rate of injuries than lower level (13), and the duration of pain is often chronic lasting greater than 1 yr (14).
Factors predisposing gymnasts to wrist pain include improper equipment, incorrect techniques, previous injury, delayed skeletal maturity, and growth spurts because of the transient weakness in the physis (8). Peak growth velocity occurs in males and females at approximately 13.5 yr and 11.5 yr, respectively. Exercises especially stressful on the wrist include floor routines, pommel horse, vault, and balance beam. The wrist can be subjected to forces up to 16 times body weight during these activities (15,16).
Gabel (2) divided the extensive list of gymnastic wrist injuries into acute and chronic and osseous and soft tissue. Chronic dorsal wrist pain in young gymnasts that gets worse with weight-bearing and extension is caused most commonly by distal radial physeal stress injuries, scaphoid impaction syndrome, and dorsal impingement syndrome. More rare conditions consist of scaphoid fractures, scaphoid stress reactions, avascular necrosis of the capitate, ganglia, and carpal instability. Skeletally mature gymnasts more commonly can have tears of the triangular fibrocartilage complex, ulnar impaction syndrome, and lunotriquetral impingement (Table).
Hand injuries in gymnasts are usually traumatic and relatively uncommon. Therefore, the focus of this chapter is on wrist injuries. Caine and Nassar reviewed injury rates for the 2002-2004 USA Gymnastics National Women's Championships and identified a paucity of hand maladies (3 of 146 reported injuries) (4). Phalangeal and metacarpal physeal injuries are some of the more common hand injuries among skeletally immature gymnasts.
DISTAL RADIUS STRESS INJURIES
The distal radius physis is a common site for injury in gymnasts because of the significant amount of load applied during upper extremity weight-bearing. In the early 1980s, Read and Roy (17,18) described radiographic abnormalities of wrist growth plates in young gymnasts. According to DiFiori et al. (14), there have since been multiple series reporting stress injuries to the distal radius physes. The incidence rates are approximately 1.9-2.7 injuries per 100 participant seasons (3,19). The typical patient with a distal radial stress fracture is a 12- to 14-yr-old female who is participating in gymnastics greater than 35 h each week (2). Symptoms begin at the onset of the offending activity and worsen during the activity. Physical examination will show tenderness along the physis and pain with extreme dorsiflexion and axial loading. Occasional swelling may be noted just proximal to the radiocarpal joint. Grip strength is often diminished compared with the contralateral extremity. Radiographic criteria for the diagnosis of stress injuries to the distal radial physis include any of the following: widening of the growth plate especially volarly and radially, cystic changes of the metaphyseal aspect of the growth plate, a beaked distal volar and radial physis, and haziness within the growth plate (20) (Fig. 1).
The cause likely is repeated injury to the growth plate from compression, distraction, and torsion forces. The etiology of physeal injury may be from compromise of the blood supply to the methaphysis and/or epiphysis (14), which can lead to abnormal endochondral ossification (2). Prolonged intensive physical loading can even lead to arrest of the distal radius physis (14). A Madelung-like deformity, where the articular surface of the distal radius is directed volar and ulnar, has been described with premature closure of the ulnar aspect of the distal radius physis (14). Risk factors for developing distal radius physeal injuries include very soft mats leading to more dorsiflexion, twisting vault routines leading to dorsiflexion and ulnar deviation, and beam activities with locked forearms and rotational moments at the wrists (14).
There are no systematic studies describing treatment in the literature. The injury can be divided into three stages. In Stage 1, the diagnosis is made clinically before radiographic abnormalities. Gradual return to participation can begin once symptoms cease. Stage 2 demonstrates radiographic radial physeal changes as described previously. Return to competition is much longer, and can be up to 2-4 months (21). Clinical and radiographic reassessment should be made before return. Serial radiographs should be examined for resolving injury to the growth plate. If symptoms return, participation should be stopped, and radiographic and clinical reassessment be performed. Rehabilitation should evaluate overall limb alignment and laxity and include both strengthening and proprioception training. Bracing in the rehabilitation phase can be considered during functional return to participation. The Gibson brace with a palm pad is particularly helpful for radial stress injuries (Fig. 2). It has a palm pad that acts like an orthotic for the hand to take the pressure off the radial physis (Nassar, L., personal communication, 2008). Stage 3 has the same clinical features as Stage 2 with ulnar positive variance on radiographs. In this stage, one should worry about ulnar abutment (14,21). There have been no studies showing correlation between magnetic resonance imaging (MRI) findings and stages of healing; therefore, MRI is not a useful prognostic tool (21).
A significant amount of research has been conducted to investigate the relationship between ulnar variance and distal radius stress injuries. Ulnar variance refers to the relative length of the ulna with respect to the radius, determined at the carpal surface. Neutral variance occurs when the bones are of equal length. It is defined as negative variance when the ulna is shorter than the radius and positive variance when the ulna is longer than the radius. Ulnar variance affects the distribution of force across the wrist. Experimental studies suggest that the load is increased across the radius as the ulnar variance becomes more negative - an increase from 80% to 96%, from ulnar neutral to −2.5 negative ulnar variance (22). As a general rule, the ulnar variance in children with open physes is usually negative. Therefore, it can be inferred that it is likely that the loading across the radius is significant in young, skeletally immature gymnasts who already have negative ulnar variances (14). There are several reports showing greater prevalence of relative and absolute positive ulnar variance in gymnasts compared with non-gymnasts in both skeletally mature and immature gymnasts (14). Over time, two conflicting longitudinal studies of ulnar variance in young gymnasts show different trends in ulnar variance. One suggests (23) increasing negative ulnar variance, and the other suggests significantly more positive variance over time (24). There is no definite evidence linking skeletally mature or immature gymnasts with positive ulnar variance with symptoms of chronic wrist pain or radiographic findings of distal radial growth plate injury (14). Young gymnasts with wrist pain and radiographic findings of distal radius physeal injury tend to have more negative ulnar variance (25). As stated previously, as a group, young gymnasts display an ulnar variance that is more positive than expected, but those with a more negative variance may be more at risk for wrist pain and distal radial physeal injury (14). If growth of the radius is affected by the repetitive loading of gymnastic training, an absolute positive ulnar variance may develop as skeletal maturity occurs.
SCAPHOID IMPACTION SYNDROME
Linscheid and Dobyns (26) described this injury as an impaction of the dorsal rim of the scaphoid against the dorsal lip of radius that is caused by forced hyperextension of the wrist. Symptoms are pain, weakness, and tenderness at the dorsal-radial aspect of the wrist aggravated with extension. Tenderness over the dorsal scaphoid is noted on physical exam, especially with the wrist positioned in flexion and ulnar deviation. Radiographs may reveal a small ossicle or hypertrophic ridge at the dorsal scaphoid rim. It is important to differentiate this condition from radial styloid impingement syndrome in which pain is usually in the anatomic snuff box and produced by radial deviation with pressure exerted on the scaphoid tuberosity from the radial styloid. Treatment of scaphoid impaction syndrome consists of rest and avoidance of hyperextension. If nonoperative modalities fail, then surgical cheilectomy of the dorsal scaphoid ridge or dorsal radial lip may be necessary (9).
Primary dorsal impingement is direct or passive extension tenderness along the dorsal rim of the radius and carpus (2). It may result from dorsal capsulitis or synovitis with resultant capsular thickening (21). In chronic cases, osteophytes may form on the dorsal rim of the distal radius, scaphoid, or lunate (21). Most cases resolve with splinting, rest, NSAIDs, and injections. Refractory cases may require wrist arthroscopy with debridement of synovitis and osteophytes, and posterior interosseous nerve excision. Diagnostic lidocaine injection of the posterior interosseous nerve is helpful in determining the source of pain and potential benefit after excision.
VanHeest et al. (27) described extensor retinaculum impingement in a retrospective series of eight wrists with this condition and correlated it with cadaveric study. Symptoms included dorsal wrist pain with extension and load-bearing in pommel horse, floor, and vault. Examination showed pain over the distal border of the extensor retinaculum. Swelling was visible and palpable just distal to the retinaculum over the tendons. A provocative maneuver of wrist hyperextension and resisted digital extension showed tenderness over the distal wrist. The cadaveric wrists showed 5 of 10 had a distinct distal border of the retinaculum that may predispose to this impingement. Two patients were successfully treated with steroid injections, while six wrists required surgery consisting of partial distal resection of the extensor retinaculum. Pathological findings from surgery included thickening of the distal border of the extensor retinaculum, concomitant extensor tendon synovial thickening, and a tendon rupture in one patient.
Wilson et al. (28) described a case of extensor tendon impingement in an elite gymnast. Significant synovitis around the extensor digitorum comminus tendons was encountered at the time of exploration. These tendons were compressed under a thickened extensor retinaculum of the fourth dorsal compartment. Attritional tears of the comminus tendons were noted. The patient's symptoms resolved following debridement along with a synovectomy and release of deep thickened retinaculum.
The scaphoid is the most commonly injured carpal bone and second to the distal radius in sports-related wrist fractures (29). Scaphoid fractures can be a result of a stress reaction, a fall onto an outstretched hand, or a direct blow. Weber and Chao (30) demonstrated that greater than 95° of hyperdorsiflexion load of the wrist in radial deviation places the scaphoid waist at the highest risk for fracture. Early and accurate diagnosis is crucial for appropriate treatment and overall outcome. Nonunion may be as high as 12% in untreated scaphoid fractures (31). Athletes who present in a delayed fashion often report difficulty with hyperdorsiflexion loading activities of the wrist. In the acute setting, discomfort is often reproducible with deep palpation in the anatomic snuffbox. Reduced mobility and decreased grip may be noted on examination. Adams and Steinmann (31) advocate an aggressive algorithm in patients with wrist trauma to evaluate for possible scaphoid fractures because unnecessary immobilization has been shown to be more expensive than aggressive diagnostic imaging in several studies. Standard anteroposterior, lateral, scaphoid view, and oblique radiographs of the wrist should be obtained. If radiographs are negative, then an MRI of the wrist is the study of choice in suspected cases of an occult scaphoid fracture (31).
Traditional treatment of stable, nondisplaced fractures has been cast immobilization. However, if early return to participation is desired, internal fixation may be the best option (32). Closed treatment can result in delayed union, nonunion, malunion, stiffness, and delayed return to play (33). Union rates are comparable with casting with operative stabilization of stable waist scaphoid fractures, approaching 95% (32,35). Prospective randomized studies comparing acute fixation with closed treatment of stable fracture have shown that patients treated surgically heal faster and return to work earlier (35,36). Most authors recommend surgically treating all displaced scaphoid fractures (those that can be seen on plain radiographs) and all proximal pole fractures. Percutaneous treatment of both nondisplaced and displaced fractures with headless cannulated compression screws can achieve nearly perfect union rates and return the player to action much quicker (33). Slade et al. (37) expanded on Whipple's technique and uses fluoroscopic assistance with a dorsal percutaneous approach. They locate the central axis of the scaphoid using the fluoroscopic scaphoid ring sign, which is achieved by flexing and pronating the wrist until the proximal and distal poles of the scaphoid are in a straight line. Postoperatively, it is recommended to undergo a rapid mobilization program using a removable thumb spica splint. Unprotected activity is allowed when bridging callus is noted. Haddad and Goddard (38) were some of the first to report on percutaneous fixation of nondisplaced fractures in athletes and showed an average healing time of 55 d in 50 patients. Return to sport with a playing cast was allowed within 2 wk. They recommend wearing a playing cast until healing is documented by CT. It should be understood that because the upper extremities are weight-bearing limbs in gymnastics, return to play may take longer to allow full healing to occur. A functional return to weight-bearing for gymnasts is facilitated with use of a wrist support such as a lionspaw splint.
SCAPHOID STRESS REACTIONS/FRACTURES
Stress fractures of the scaphoid are rare conditions, which have been infrequently described in the literature (39-43). Hanks et al. (39) presented a series of four such fractures in three athletes. Two were male gymnasts, with one having bilateral stress fractures. In addition, Engel et al. (43) described bilateral stress fractures in a young gymnast. The mechanism of injury is repetitive compressive loads to the wrist in varying degrees of extension. The repeated trauma is insufficient to create an acute fracture, but over time can lead to stress changes. In addition, forearm muscle fatigue can lead to increased abnormal loading of forces on the scaphoid. Over time, a stress reaction occurs at the scaphoid waist, and later a frank fracture can occur. Early symptoms include chronic wrist pain without a specific injury and tenderness over the scaphoid that is worse with hyperextension and radial deviation. X-rays may show sclerosis at the waist early and later a distinct fracture line. A physician should be alert to the possibility of a stress fracture in a high-performance gymnast who continues to load cyclically a painful wrist even in the setting of a negative radiograph. Treatment includes immobilization until radiographic healing is noted. Matzkin (41) presented a 13-yr-old in which successful treatment involved 8 wk in long arm spica cast followed by 4 wk in a short arm splint.
AVASCULAR NECROSIS OF CAPITATE
Avascular necrosis of the capitate has only been reported in two gymnasts (44) and was likely caused by interruption of blood flow to the head of the capitate from repetitive microtrauma. The blood flow to the head is retrograde, and any injury to the neck may lead to resorption of the head. These two athletes underwent partial resection and drilling, allowing them to resume their immediate careers. Long-term follow-up was not mentioned (21), and later failure may require intercarpal fusion procedures (2).
Occult dorsal ganglia may result from repetitive dorsal stress from gymnastic activities, and they may cause dorsal wrist pain. The cysts can be secondary to scapholunate pathology (21). Symptoms include pain with dorsiflexion in loading conditions as they impinge dorsally (2). Point tenderness over the scapholunate ligament is usually found on physical examination (21). If immobilization, rest, and possible aspiration (2) with or without corticosteroid injection fail to resolve symptoms, excision in combination with posterior interosseous nerve resection is usually curative (21).
The scapholunate interosseous ligament is one of the key ligaments in maintaining stability of the carpus. The ligament consists of dorsal, proximal, and volar segments connecting the scaphoid to the lunate. Injury to this ligament is the most common and most significant ligament injury to the wrist. The spectrum of injury ranges from dynamic scapholunate instability in which there are no findings on standard radiographs of abnormalities to frank dissociations in which the scaphoid can dislocate and rotate into a volarly flexed position. The mechanism of injury is axial loading with wrist extension and ulnar deviation with the capitate driven between the lunate and scaphoid. Both acute falls on an outstretched hand or repetitive chronic forces on the wrist can cause this injury. History and physical may show pain on the dorsal radial wrist, loss of motion, and decreased grip strength (46). The Watson maneuver may be positive. This maneuver is performed by placing constant pressure by the examiner's thumb over the volar aspect of the distal pole of the scaphoid while the wrist is moved from extension and ulnar deviation to flexion and radial deviation. Wrist pain or a clunk may be elicited. Often these patients present after experiencing symptoms for an extended period of time because of the lower level of pain experienced chronically, or because it was initially clinically missed. Static scapholunate diastasis will present radiographically as a scapholunate distance greater than 3 mm (Terry Thomas sign). Dynamic instability may require stress views or clenched fist views. A scapholunate angle greater than 70° and cortical ring sign may be seen (45), with chronic cases possibly showing dorsal intercalated segment instability (DISI) with eventual degenerative changes throughout the carpus. MRI arthrography is an excellent imaging modality to evaluate the integrity of the ligament or bone edema. Arthroscopy is the gold standard for evaluation of the competency of the ligament and is often useful for evaluating for dynamic instability. Geissler has recently described four grades of scapholunate instability based on arthroscopic evaluation (46). During arthroscopy, debridement and/or repair can be performed (45).
Snider et al. (45) presented three case reports of gymnasts with chronic dorsal wrist pain exacerbated with axial loading. These patients all had partial scapholunate ligament tears and mild synovitis noted during arthroscopy. They hypothesized that the twisting, dismount activity in gymnastics placed maximal stress on the radial column of the wrist. They also recommend future consideration to the use of dorsiflexion limiting wrist supports to prevent these injuries.
TRIANGULAR FIBROCARTILAGE COMPLEX (TFCC) TEARS
Ulnar sided wrist pain is more common in skeletally mature athletes and is often caused by injury of the triangular fibrocartilage complex. It is more common in older gymnasts because of the higher frequency of ulnar positive variance and increased ulnar sided transmission of force from the repetitive weight-bearing over time. Differential diagnosis of ulnar sided wrist pain in the gymnast includes: extensor carpi ulnaris instability/tendonitis, distal radio-ulnar instability, TFCC tears, lunotriquetral tear, pisotriquetral joint dysfunction, and flexor carpi ulnaris tendonitis. The examiner must assess for other pathology when evaluating the athlete with ulnar wrist pain. Tenderness secondary to a TFCC tear is noted with deep palpation between the flexor carpi ulnaris and the ulnar styloid. Pain may be reproduced by positioning the wrist in ulnar deviation and pronation. Mandelbaum et al. (11) proposed a diagnostic and treatment algorithm initiated with a conservative treatment including rest, NSAIDs, ice, therapy, and modification of training. If symptoms persist, then a period of 4-6 wk of immobilization and cessation of gymnastic activities is begun. Persistent pain warrants work-up with an MRI arthrogram, which has been shown to correlate well with arthroscopic findings (11). In the absence of distal radial-ulnar joint instability, a cortisone injection into the ulno-carpal joint can be entertained as a treatment option in gymnasts with recalcitrant pain. Relief of symptoms after the injection may facilitate a gradual return to participation. Arthroscopic debridement of central tears often renders good results. TFCC repair is the mainstay of treatment in peripheral tears.
ULNAR IMPACTION SYNDROME
Ulnar carpal abutment can be either developmental or acquired, such as from a previous injury to the radial growth center in a gymnast. Increased stress across the ulnocarpal joint may occur with repetitive loading of the wrist in dorsiflexion, ulnar deviation and pronation. Force transmission across the ulnocarpal joint can increase with positive ulnar variance (47). If ulnar deviation is combined with pronation, the ulnar loading can increase from 15% to 40% (2). Injuries that can occur from these forces include tearing of the TFCC, attritional tears of the lunotriquetral ligament, chondromalacia, subchondral sclerosis, and subchondral cyst formation on the lunate, triquetrum, and ulna (Fig. 3). Symptoms include tenderness over the proximal lunate and triquetrum made worse with forced ulnar deviation. Physical exam may show ulnar snuff box tenderness and passive ulnar deviation tenderness. Radiographs may show positive ulnar variance and possible cyst or sclerosis formation in the ulnar head or lunotriquetral region (2). Nonoperative treatment is attempted first with rest, NSAID, steroid injections, and modification of training. If unsuccessful, an attempt at immobilization and cessation of gymnastics for 4-6 wk can be initiated. MRI then should be ordered to evaluate the TFCC and intercarpal ligaments.
If clinical exam is concerning for intercarpal ligament tear (lunotriquetral), then MRI arthrogram should be obtained during the early stages of evaluation. In cases of recalcitrant pain, an unloading procedure of the ulna is indicated. Recent literature suggests that arthroscopic wafer resection is just as effective as ulnar shortening osteotomy in relieving pain in these patients (48).
This condition is caused by impingement of the dorsal lunate and triquetral rims and is caused by repetitive wrist hyperextension and ulnar deviation. Symptoms are tenderness over the lunotriquetral joint that is worse with extension and ulnar deviation. Treatment is first rest, immobilization, and NSAID followed by surgical intervention if nonoperative measures fail (9).
We have reviewed some of the most common wrist injuries in gymnasts. The gymnast's wrist is subjected to a high level of force transmission across the radiocarpal and ulnocarpal joints as a result of the significant weight-bearing loads required of the sport. Many of these stresses are imparted during a significant period of longitudinal growth of the wrist, creating potential for physeal injury. It is important to quickly and accurately diagnose the specific injury to expediently initiate the proper treatment and limit the extent of injury. Prevention should also be an important aspect of a gymnast's training regimen. Concepts to be considered include the following: individualize the training, gradually increase training loads, reduce high loads during growth spurts, alternate loading activities, and consider the possibility of wrist orthoses.
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