Resultados

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of injury is a hyperextension force applied to the flexed finger, such as that occurs when a player attempts to grasp an opponent’s jersey. While the opponent acceler- ates, the player’s finger is forced into extension against the active flexion force being generated. The flexor ten- don avulses from the base of the distal phalanx (with or without bone) and retracts proximally. The degree of retraction is quantified according to the Leddy and Packer classification.6 _{Type I injuries occur when the}

FDP tendon retracts to the level of the palm. With this injury, the blood supply is usually disrupted, and if treatment is delayed, the flexor sheath may not permit passage of the tendon. Type II injuries occur when the tendon retracts to the level of the PIP joint (the tendon sheath is not compromised, no significant contractures occur, and the tendon can be repaired up to 6 weeks af- ter injury), and type III injuries occur when the tendon remains at the level of the DIP joint. When the finger is examined, the patient is unable to actively flex the DIP joint. It is difficult to predict the type of avulsion from radiographs and clinical examination. For optimal re- sults, urgent surgery is indicated in acute cases.5 Pulley Rupture

Closed rupture of the flexor tendon pulleys is an injury commonly seen in rock climbers. The specific hand and finger positions required during climbing can result in significant force transmission to the pulley system. When the climber’s hand or foot slips off a hold, even greater stresses are placed on the hand, and the biologic strength of the pulley can be exceeded, leading to a rup- ture. The middle and ring fingers are the most prone to

injury. Patients will report an acute onset of pain and may report a loud popping noise. Clinically, there will be tenderness along the palmar aspect of the injured pulley, with swelling and possible hematoma. Bow- stringing will be visible only with multiple ruptures. Plain radiographs always should be obtained to rule out an associated fracture. MRI is highly accurate in identifying the dehiscence of the tendon from the bone (damage to the pulley itself cannot be detected di- rectly). However, recent reports have shown that a dy- namic ultrasound examination has similar if not better accuracy than MRI and can be considered the gold standard; only when the diagnosis is in doubt is addi- tional imaging with MRI required.7

Single pulley ruptures should be immobilized for 10 to 14 days followed by supervised hand therapy and tape or rings to protect the pulleys. Multiple pulley ruptures are best treated surgically. Pulley repair has not been shown to produce adequate results, and reconstruction (with tendon graft) of the damaged pulleys is required. After surgery, the finger is immobilized for 14 days, fol- lowed by early functional motion with pulley protection as previously described. For patients treated either sur- gically or nonsurgically, sport-specific activities may be- gin at 6 to 8 weeks (with continued pulley protection) and full sports participation may begin at 3 months. Tap- ing or the use of rings should continue for at least 6 months. Final results are usually good with near-normal recovery of motion and strength.7

Figure 7 A, A defect in central slip results in unopposed

flexion at the PIP joint. B, A lack of intact dorsal structures results in volar subluxation of lateral bands, a resultant flexion force at the PIP joint, and extension force at the DIP joint. (Repro-

duced with permission from Baratz ME, Schmidt CC, Hughes TB: Extensor tendon injuries, in Green DP, Pederson WC, Hotchkiss RN, Wolfe SW (eds): Green’s Operative Hand Surgery. Phil- adelphia, PA, Elsevier, 2005, p 203.)

Figure 8 Radiograph showing central slip avulsion and re- sultant boutonniere deformity.

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Skier’s Thumb

Acute ulnar collateral ligament (UCL) injury to the thumb is a common injury among skiers. The mechan- ism of injury is a sudden, forced radial deviation of the abducted thumb, which often results from a fall onto the outstretched hand while the thumb is gripping a ski pole. Patients will have tenderness and fullness along the ulnar border of the MCP joint. The thumb may be aligned in radial deviation at the MCP joint, there will be laxity of the UCL on stress testing (positive test if greater than 30° laxity is present with testing in exten- sion and flexion or greater than 15° laxity when com- pared with the contralateral thumb), and there may be an appreciable ligamentous end point. In the case of a Stener lesion, a nodule of recoiled UCL may be palpa- ble proximal to the MCP joint.8 _{Radiographs may be}

normal or may reveal radial displacement and/or volar subluxation (suggests a significant dorsal capsular tear) of the proximal phalanx and possibly an avulsion frac- ture at the ulnar base of the proximal phalanx. Radio- graphs should be obtained before the joint is stressed to avoid displacement of a nondisplaced avulsion fracture. An MRI or ultrasound may assist in confirming the presence of an underlying Stener lesion.

Acute partial ruptures or nondisplaced avulsion frac- tures can be treated with 4 weeks of continuous immo- bilization in a thumb spica cast, followed by 2 weeks of splinting with active range-of-motion exercises. Strenu- ous activity should be avoided for 3 months. Large fractures with more than 2 mm displacement or with articular incongruity will require open reduction and

internal fixation. Complete ruptures can be treated nonsurgically or surgically; if an associated Stener le- sion (adductor aponeurosis is interposed between the distally avulsed ligament and its insertion into the base of the proximal phalanx) is present, surgery is neces- sary because this lesion will not heal with immobiliza- tion alone.

Ruptures that appear to be complete clinically may require additional investigation to rule out the possibil- ity of a Stener lesion. Stress radiographs have been used to identify a complete lesion but are difficult to obtain in patients with acute injury because of pain and dis- comfort. With an experienced operator, ultrasonogra- phy is a noninvasive, inexpensive, accurate means of detecting a Stener lesion;9,10 _{MRI is an accurate but}

more costly alternative11_{(Figure 9).}

Traditionally, open reduction has been used with several fixation techniques, all resulting in uniformly good results. Recent studies describe arthroscopic tech- niques of reducing the Stener lesion followed by percu- taneous pinning, thus avoiding violation of the joint.12

Postoperatively, a thumb spica cast is worn for 4 weeks, followed by a protective splint and range of motion. Patients may participate in unrestricted activity at 3 months, but full athletic participation should not commence until 4 months (with continued taping or semirigid splinting as necessary).

Hook of Hamate Fractures

Hook of hamate fractures occur as a result of direct force during a fall or crush injury, or with repeated mi- crotrauma during forceful grip while using a racket or bat during participation in sports such as golf, baseball, and hockey. Patients will have pain along the volar ul- nar aspect of the hand, especially during activities re- quiring a tight grip. Callus may be present when exam- ining the skin overlying the hook of hamate (suggesting repetitive trauma), along with pain during direct palpa- tion over the hook of the hamate and possible dysesthe- sia involving the ulnar nerve. Standard radiographs may not reveal the fracture, making a carpal tunnel view necessary. Because diagnosis of these injuries is difficult, a CT scan should be obtained in any patient in whom fracture is suspected.

The recommended treatment for hook of hamate frac- tures that offers the most predictable option for pain-free results is excision of the fragment. There have been re- ports of success with cast immobilization; however, the risk of nonunion is high given the intrinsic forces exerted on this bone. Open reduction and internal fixation also has been described, with variable results; in the athlete, there is a risk of possible nonunion, and the mass effect created by the hardware can be bothersome. Range-of- motion and strengthening exercises may begin immedi- ately after surgery. Patients may report scar sensitivity for 4 to 6 weeks. When an athlete returns to sports par- ticipation, a glove with a doughnut-shaped pad can be worn until the scar is no longer tender.13

Figure 9 MRI scan of a Stener lesion.

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Arthritis

The trapeziometacarpal joint is a common source of basal thumb pain commonly affecting older women but also is relatively common in younger patients. Symp- toms usually consist of pain, stiffness, and difficulty with pinch and grasp. The treatment algorithm begins with conservative care, the use of nonsteroidal anti- inflammatory medications, splinting, and cortisone in- jections. Cortisone injections may provide temporary relief, but they also have been associated with acceler- ated joint damage and worsening capsular attenuation. Once nonsurgical treatment options have been ex- hausted, treatment for advanced disease is with trape- ziectomy with or without ligament reconstruction and tendon interposition.14_{Although a viable option for the}

older patient who is less active, trapeziectomy is not suitable for young patients.

For young patients, surgical interventions tradition- ally include an extension osteotomy, which unloads the volar ulnar portion of the joint, redirects forces, and provides some pain relief in early stages of the disease. Traditionally, the other option has been fusion. Re- cently, there has been an increasing interest in arthro- scopic management of arthritis. In younger patients, ar- throscopic treatment is advantageous because it can offer significant pain relief without compromising fu- ture procedures. The arthroscope can be used to per- form a joint débridement and synovectomy or to inter- pose a spacer (autogenous tendon, fascia lata, or synthetic material) into the degenerative joint. This technology is still evolving but may be an attractive op- tion for the young patient with early arthritis.15

Ulnar Wrist Injuries

Athletes who participate in stick-and-ball sports fre- quently sustain acute or overuse injuries to the struc- tures of the ulnar wrist. In addition to the ubiquitous possibility of direct trauma, all wrist structures are sus- ceptible to the high angular velocity and torque de- mands resulting from striking or catching any object, accelerating or decelerating a long lever arm implement (stick, bat, club, racquet), buffering a fall, or grasping an opponent. Every tissue of the ulnar wrist may be in- jured, and combination trauma is not uncommon.

Osseous Pathologies

The most frequently encountered bone injuries are ul- nar styloid fractures, triquetral body fractures, and pisotriquetral joint subluxations (with or without os- teoarticular fracture). Additionally, ulnocarpal abut- ment, caused by radioulnar length discrepancy, may oc- cur during participation in sports such as gymnastics or be a source of ulnar-sided symptomatology.

Ulnar Styloid Fracture

Ulnar styloid fractures often are associated with frac- tures of the distal radius and can be as different in pat-

tern and significance as the morphology of the styloid itself. It is most important to determine whether a bony injury is stable or results in a destabilizing injury to the distal radioulnar joint.

Because the styloid is the anchor or limbi for the dis- tal radioulnar joint ligaments, any clinical symptoms after fractures may be related more to the surrounding soft-tissue injuries. Styloid tip fractures and many sty- loid body fractures are not associated with significant soft-tissue disruptions. These fractures can be treated symptomatically; even nonunions of the ulnar styloid fractures that are nontender or not associated with dis- tal radioulnar joint (DRUJ) instability can be simply ac- knowledged and observed.

When fractures of the styloid occur at the base or fovea, potential loss of DRUJ stability becomes an is- sue.16 _{To determine whether the DRUJ has been ren-}

dered unstable at its bony attachment by a basistyloid fracture, examination in three positions of forearm ro- tation is necessary. In forearm neutral, physiologic lax- ity at the joint should be present. The radiocarpal unit translates rather freely in both the volar and dorsal di- rections; in patients with inherent physiologic laxity or a collagen vascular disorder, the magnitude of this translation may be considerable but still not reflect a pathologic condition. When the forearm is positioned in the extremes of either pronation or supination, the DRUJ relationship should be stable and resist manual translation.

When the DRUJ is stressed in pronation, excessive volar translation of the radiocarpal unit, which moves the ulnar head dorsally, may be indicative of a destabi- lizing injury. The converse is true in supination; if the ulna is moved to a volar position by manipulation, DRUJ instability may be present. It is often helpful to examine the contralateral extremity for asymmetry.

Advanced cross-sectional imaging (MRI or CT) will not add much diagnostic specificity to the evaluation of ulnar styloid fractures. However, evaluation of fracture behavior under live fluoroscopy, especially noting the largest degree of absolute displacement, helps to deter- mine the severity of injury.

Triquetral Body Fracture

Isolated fractures of the triquetral body are rare, but most occur during athletic activity. When there is ulnar wrist pain distal and dorsal to the ulnar styloid, then triquetral pathology should be entertained.

Imaging of this fracture is challenging because the pisiform shadow obscures the midbody, where the frac- ture typically occurs. Both MRI (demonstrating edema and fracture) and a CT scan may be necessary when the diagnosis is elusive and triquetral body fracture is sus- pected.

Nondisplaced fractures can be treated with immobi- lization, and athletes may be permitted to participate in gloved sports (hockey and football). If fracture dis- placement occurs, variable pitch screw fixation placed through a dorsoulnar approach may be needed. Failure

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of the triquetrum to unite has been reported but is rare.17

Pisotriquetral Injury

Pisotriquetral pathology is a rare but recognizable cause of ulnar and volar pain. These injuries occur sec- ondary to a combination of mechanisms: repeated fall- ing onto the outstretched hand or fending off oppo- nents with a dorsiflexed wrist posture (stiff arm), coupled with the strong activation of the flexor carpi ulnaris tendon in which the pisiform resides.

With loading and shear, there is a possibility of os- teochondral fracture of the periarticular platform of the triquetrum or instability of the pisiform, in addition to crepitus, positional locking and unlocking, and pain.

Treatment of attenuation of the ligamentous invest- ments that maintain the pisotriquetral relationship is brief immobilization, with some splinting or taping to limit flexor carpi ulnaris excursion. When a fracture has altered the articular anatomy of the pisiform or the triquetral platform, then power grasp or direct pressure on the pisiform region can be painful or manifest as perceived instability or weakness. In selected cases, the fractured fragments may cause definitive mechanical symptoms and should be removed.

Ulnocarpal Abutment

The relationship between the radius and ulna through the entire forearm axis is best thought of as a single mechanism in which the mobile radius circumscribes a “radius” around the forearm’s stable unit, the ulna. In addition to rotation, there are relative length changes, as well as translations between the bones. The two critical articulations, the proximal DRUJ and the DRUJ, remain in appropriate articulation throughout the full arc of rotation. Ulnocarpal abutment is a me- chanical pathology that can be either developmental or acquired as a result of chronic or acute injury to the forearm, usually to the growth centers of the ra- dius in the skeletally immature patient (such as with gymnast’s wrist). If the growth of the radius has been retarded by injury or repetitive compression (Heuter- Volkmann principle), then a radioulnar length discrep- ancy resulting in ulnocarpal abutment can cause ulnar- sided wrist symptoms. Although the biomechanical effects of increased ulnar variance on the ulnar wrist are well understood, few studies have been done at the microscopic level.18 _{A recent study identified an in-}

crease in apoptosis within the cellular components of the triangular fibrocartilage complex (TFCC) in pa- tients with a positive ulnar variance.19_{The study results}

suggest that deleterious effects at the cellular level take place as a result of increased ulnar length or ulnocarpal abutment. The spectrum of abutment and DRUJ insta- bility are clinical conditions that can occur with posi- tive ulnar variance. DRUJ instability results from a mis- match between the location or path of the sigmoid fossa of the radius as it accepts the articular ulna, re- ferred to as the ulnar seat, or the portion that maintains

direct articular contact with the sigmoid fossa of the ra- dius.

Optimal treatment of recalcitrant ulnocarpal abut- ment has been a subject of debate. The relative success of conventional ulnar shortening and a subtotal, tan- gential distal articular surface resection (the wafer pro- cedure), the two most common ways in which the ulnar column is recessed to diminish or eliminate the contact between the ulnar pole and lunate, has been stud- ied.20,21

Because as many as 25% to 30% of patients under- going TFCC débridement or radialization of TFCC tears alone had persistent symptoms, surgeons sought to decompress the ulnar column(Figure 10). The two options described differ in fundamental ways. Ulnar shortening osteotomy is an open procedure with sub- stantial bony manipulation and instrumentation. The wafer procedure is a less invasive alternative that, de- spite technical challenges, is typically performed with- out substantial morbidity through standard arthro- scopic portals or arthroscopy coupled with a minimally invasive approach to the distal ulna to remove the ul- nar pole, the ulna’s most distal portion that comes in contact with the undersurface of the TFCC articular disk, with an osteotome.

Investigators found that similar profiles of pain re- lief and functional restoration were obtained with both procedures. Patients undergoing the wafer procedure may have some ulnar discomfort for 3 to 4 months but ultimately achieve pain relief similar to an ulnar shortening osteotomy. However, secondary proce- dures (hardware removal) surrounding soft-tissue irri- tation (tendinitis) and more significant complication (nonunion) may occur during formal ulnar shorten- ing.20,21

Figure 10 The arthroscopic image demonstrates a central attritional tear of the TFCC (probe palpating the defect). The findings of chondromalacia of the proximal ulnar pole of the lunate are con- sistent with ulnocarpal abutment.

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Ligamentous Injury

The two most common injuries in patients with ulnar- sided wrist pain are to the TFCC-associated ligaments, including the radioulnar ligaments (or limbi) and the disk-carpal ligaments. These two separate ligament complexes represent the primary stabilizers between the radius and ulna, and the TFCC and ulnar carpus, re- spectively. Injuries to either or both of these soft-tissue stabilizers can cause pain or perceived instability that may prevent athletic participation.

Much has been learned about the soft tissues associ- ated with the TFCC and volar ligaments on the ulnar side of the wrist.22 _{The primary distal stabilizing liga-}

ments anchored at both the ulna’s foveal region and styloid medially and at the juxta-articular margin of the