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Injuries to the Ulnar Collateral of the Thumb Metacarpophalangeal

Philip Heyma n, MD

Abstract ment, the palmar plate, and, to a limited extent, the dorsal capsule. Injuries to the ulnar collateral ligament of the metacarpophalangeal (MCP) Biomechanical and clinical studies joint of the thumb are relatively common. When an incomplete rupture is pres- have shown that each of these ent, valgus stress testing with the MCP joint positioned in extension reveals structures contributes to joint sta- minimal or no instability (less than 30 degrees of laxity or less than 15 degrees bility and that their contribution is more laxity than in the noninjured thumb). When a complete rupture is pres- dependent on the position of the ent, valgus stress testing with the MCP joint positioned in extension reveals MCP joint.2,3 In flexion, the taut marked laxity (more than 30 degrees or more than 15 degrees more laxity than proper collateral ligament, which in the noninjured thumb). In this instance, displacement of the ligament proxi- runs from the middle of the mal and superficial to the adductor aponeurosis, which is often termed a Stener metacarpal head to the palmar lesion, is likely. Partial ligament injuries in which the ligament is not displaced aspect of the proximal phalanx, is may be treated nonoperatively. When a Stener lesion is present, however, pri- the primary joint stabilizer (Fig. 1). mary ligament healing cannot occur without operative management. Whether Because of this configuration, it treatment should be operative or nonperative can generally be decided on the also prevents palmar subluxation basis of the findings from the history, the radiographs, and the physical exami- of the proximal phalanx. The dor- nation, which should include valgus stress testing. sal capsule is also taut in flexion; J Am Acad Orthop Surg 1997;5:224-229 however, it is relatively flimsy and thus much less important than the In 1955, Campbell1 described the can injure the ulnar collateral liga- proper collateral ligament in stabi- clinical signs and symptoms of ment. Because stability of the lizing the flexed joint. In addition, ulnar collateral ligament insuffi- thumb is important for prehension, because of its redundancy, the dor- ciency of the metacarpophalangeal treatment is directed toward opti- sal capsule does not play an im- (MCP) joint of the thumb, calling it mizing ligament healing in order to portant role in preventing palmar “gamekeeper’s thumb” because it restore full function. subluxation of the proximal pha- was a frequent occupational injury lanx. The accessory collateral liga- of Scottish gamekeepers. The term ment is palmar to and contiguous described a chronic attritional Anatomy and injury resulting in instability, Biomechanics accompanied by pain and weak- ness of pinch and grasp. The MCP joint is a diarthrodial Dr. Heyman is in private practice with Today, the practicing ortho- joint that is primarily involved in Surgery Associates, PC, Denver. paedist usually sees valgus insta- flexion and extension, but which bility of the thumb MCP joint that also allows some rotation, abduc- Reprint requests: Dr. Heyman, Hand Surgery has been caused by an acute injury. tion, and adduction. Joint stability Associates, PC, Suite 500, Porter Medical Plaza, 2535 South Downing, Denver, CO is provided by static restraints and Because the injury is commonly 80210. caused by a skiing accident, it is dynamic stabilizers. now often referred to as “skier’s The static restraints of the MCP Copyright 1997 by the American Academy of thumb.” However, any severe val- joint are the proper collateral liga- Orthopaedic Surgeons. gus force on the abducted thumb ment, the accessory collateral liga-

224 Journal of the American Academy of Orthopaedic Surgeons Philip Heyma n, MD

Accessory collateral ligament

Proper collateral ligament

Palmar Palmar ligaments Sesamoid bone Sesamoid bone

Fig. 1 Left, In flexion, the proper collateral ligament and the dorsal capsule are tight. Right, In extension, the proper collateral ligament and the dorsal capsule are loose, and the accessory collateral ligament and palmar plate are tight. with the proper collateral liga- joint may hyperextend, or it may Pathologic Anatomy ment. It extends palmarward and lack full extension. The amount of attaches to the volar plate. valgus laxity is also variable in A wide spectrum of pathologic dis- In extension, the accessory col- normal thumbs. In full extension, orders have been reported after lateral ligament and the palmar valgus laxity averages 6 degrees. acute valgus injuries to the thumb plate are taut and are the primary Valgus laxity increases to an aver- MCP joint. There may be rupture joint stabilizers against valgus age of 12 degrees when the joint is of the dorsal capsule, adductor stress.2,3 When a traumatic valgus positioned in 15 degrees of flex- mechanism, and extensor pollicis force is applied to the thumb MCP ion.6,7 brevis.10 Anatomic, biomechanical, joint, the proper collateral liga- and clinical studies have shown ment, the accessory collateral liga- that when the injury is limited to ment, and the palmar plate provide Mechanism of Injury these structures, the thumb will be joint stability when the dynamic stable on valgus stress testing.3 stabilizers are overcome.2-4 Any extreme valgus stress to the More severe injuries involve rup- The dynamic stabilizers include thumb can result in ligamentous ture of the proper collateral liga- the thumb extrinsic muscles (exten- disruption. The most common ment. sor pollicis longus, extensor pollicis mechanism is a fall on the abduct- When the proper collateral liga- brevis, and flexor pollicis longus) ed thumb. In skiing, it has long ment is ruptured, instability will be and intrinsic muscles (abductor been thought that the ski pole plays present when the thumb is tested pollicis brevis, flexor pollicis bre- an important role in the pathogene- in flexion.4 When the accessory vis, and adductor pollicis). The sis of this injury. In the 1960s, most collateral ligament is also torn, the adductor mechanism is of particu- ski-pole handles had a strap that tear is considered complete, and lar importance as a dynamic stabi- passed between the thumb and the there is instability in extension as lizer.5 It inserts into the extensor index finger and wrapped around well as flexion.3 Rupture of the expansion through its aponeurosis, the . With increased aware- ulnar collateral ligament is typical- which lies superficial to the joint ness of this injury, many new grip ly at its distal insertion site on the capsule and the ulnar collateral lig- designs were subsequently devel- base of the proximal phalanx. ament. The adductor also has a oped. These include strapless grips Occasionally, however, the rupture deep insertion into the palmar with molded hand pieces, with or is in the midsubstance or more aspect of the proximal phalanx by without a platform for the hand. proximal.4,6,9 way of the ulnar sesamoid. However, newer design modifica- Displacement of the distal end There is considerable variation tions have not had any detectable of the completely ruptured liga- in the range of flexion and exten- effect on preventing this injury.8 ment can occur such that it comes sion of the thumb MCP joint. Some have suggested that the ski to lie superficial and proximal to Some normal demonstrate as pole prevents adduction of the the adductor aponeurosis (Fig. 2). little as 5 degrees of motion, while thumb, which normally occurs dur- This pathologic entity was first others have a range of as much as ing a fall, thus making the thumb described by Stener in his classic 115 degrees.6,7 The normal MCP more exposed to injury.9 paper in 1962.4 There is general

Vol 5, No 4, July/August 1997 225 Ulnar Collateral Ligament Injuries of the Thumb

Ruptured collateral ligament

Adductor aponeurosis Adductor aponeurosis (retracted)

Fig. 2 Left, When a complete rupture of the ulnar collateral ligament is present, the distal end of the torn ligament is usually displaced proximal and superficial to the proximal edge of the intact adductor aponeurosis. Right, Division of the adductor aponeurosis is required for repair of the ligament.

agreement that, due to the interpo- seen on the posteroanterior view, patients will usually demonstrate sition of the adductor aponeurosis, which is highly indicative of a com- guarding; therefore, local anesthet- these injuries do not heal with non- plete rupture. However, in most ic should be infiltrated into the operative treatment. Because the cases of partial or complete liga- ulnar aspect of the joint before proper collateral ligament is ment ruptures, plain films appear stress testing. Some authors sug- anatomically contiguous with the normal. gest a median and/or ulnar nerve accessory collateral ligament along block at the wrist to negate the sta- their common edge, isolated prop- bilizing effect of the intrinsic mus- er collateral ligament tears are pre- Evaluation cles.5 However, if pain is relieved vented from complete displace- by an injection into the joint alone, ment by the intact accessory collat- Patients with suspected ulnar col- these nerve blocks are not neces- eral ligament.3 lateral ligament injuries will pre- sary. Occasionally, radiographs will sent with a history of valgus injury The integrity of the proper col- show an avulsion fracture from the followed by pain and swelling on lateral ligament is then assessed by ulnar aspect of the base of the prox- the ulnar aspect of the MCP joint. carrying out valgus stress testing imal phalanx (Fig. 3). This frag- Ecchymosis is frequently seen as with the MCP joint in 30 degrees of ment may be a small fleck or may well. Palpation of the ulnar aspect be of substantial size.4,10 Active of the joint may reveal a lump. contraction of the adductor at the This finding represents the distal time of injury has been implicated end of the displaced ligament and in the pathogenesis of this injury.11 is highly suggestive of a Stener Avulsion fractures may be dis- lesion.3,4,12 However, lack of a placed or nondisplaced. The pres- mass does not rule out a Stener ence of a nondisplaced avulsion lesion.3 Before valgus stress test- fracture does not rule out a com- ing, radiographs should be ob- plete ligament rupture. Con- tained. In some cases in which an versely, there are cases in which ulnar collateral ligament rupture is the avulsion fracture is displaced suspected, the films will show a and rotated and the ulnar collateral fracture of the thumb metacarpal ligament is intact or only partially or the shaft of the proximal pha- ruptured. lanx. Valgus stress testing is con- Lateral radiographs may show traindicated in these cases. Fig. 3 Avulsion fracture sustained by a palmar subluxation of the proximal After assessment with pos- 45-year-old man. The MCP joint was stable on valgus stress testing. After immobiliza- phalanx. This finding suggests teroanterior and lateral plain radio- tion for 4 weeks, the thumb was painless extensive ligamentous disruption.10 graphs, valgus stress testing should and stable. Radial subluxation is occasionally be carried out. Acutely injured

226 Journal of the American Academy of Orthopaedic Surgeons Philip Heyma n, MD flexion. To avoid a false interpre- mation to that which can be section, held in the displaced posi- tation, the examiner must prevent obtained by an accurate physical tion by the proximal edge of the MCP rotation by grasping the examination. adductor aponeurosis (Fig. 4, B). thumb proximal to the joint. If The adductor aponeurosis is there is more than 30 degrees of then incised longitudinally, parallel laxity (or 15 degrees more laxity Recommended Treatment and just palmar to the extensor pol- than on the noninjured side), rup- Algorithm licis longus tendon. The adductor ture of the proper collateral liga- aponeurosis is retracted distally ment is likely. The thumb is then When a joint is stable when tested and the dorsal capsule, which is positioned in extension for repeat in flexion, the ligament is only par- frequently torn, is inspected, after valgus stress testing. If valgus lax- tially ruptured, and a Stener lesion which the proper collateral liga- ity is less than 30 degrees (or 15 is not present. Ligament healing ment and the accessory collateral degrees less than on the nonin- will occur by nonoperative means. ligaments are assessed. jured side), the accessory collateral A period of immobilization in a If palmar subluxation was seen ligament is intact. Because the short -thumb spica cast for 4 on the preoperative radiographs, or accessory collateral ligament is weeks is appropriate. The inter- if the surgeon believes soft-tissue contiguous with the proper collat- phalangeal joint may be left free if repair will not hold the joint in a eral ligament, the intact accessory the cast is otherwise well molded. reduced position, joint reduction collateral ligament will prevent In some cases, a hand-based cast or and pinning should be carried out. complete displacement of the a splint made of heat-molded plas- A smooth 0.045-inch Kirschner proper collateral ligament, pre- tic can be used. Treatment for wire is passed antegrade through cluding a Stener lesion. If valgus these less severe injuries can be tai- the base of the proximal phalanx laxity is greater than 30 degrees (or lored to the patient’s needs, accord- and out through the skin on the 15 degrees more than on the non- ing to the surgeon’s judgment. radial side of the thumb. The joint injured side), the accessory collat- After the period of immobilization, is then held in a reduced or slightly eral ligament is also ruptured. In active and passive range of motion overreduced position in 15 degrees these complete ruptures, ligament can be started. Grip strengthening of flexion, and the wire is passed displacement (i.e., a Stener lesion) can begin by the sixth week. retrograde across the joint. Fluoros- is more than 80% likely.3 In the thumb is unstable in copy can be used to confirm that The examining orthopaedist extension (more than 30 degrees of the joint is well positioned. may be concerned about valgus laxity or 15 or more degrees of laxi- The collateral ligament is then stress testing in cases in which ty than on the noninjured side), a repaired. In the rare case of a mid- there is a nondisplaced avulsion complete rupture is present, and substance tear, a direct repair may fracture; there may be fear of dis- ligament displacement is likely.3 be carried out with absorbable 4-0 placing a nondisplaced ligament Operative management is neces- suture material. If there is a small rupture. Valgus stress testing sary in this setting. fragment of bone associated with should be performed regardless of the avulsed ligament, this should whether such an avulsion fracture be excised. A larger fragment is present. In most instances, the Surgical Technique should be preserved. A number of mechanism of injury is a fall; if lig- techniques for repairing the liga- ament displacement does not occur Surgical repair can be carried out ment, with or without an associat- at the time of such an extreme or with use of a regional anesthetic ed avulsion fracture, have been violent uncontrolled injury, stress- (axillary block or Bier block) and described. Many advocate use of a ing the joint under controlled cir- tourniquet control. A chevron or S- transosseous suture of stainless- cumstances should not cause liga- shaped incision is used (Fig. 4, A). steel wire or other nonabsorbable ment displacement. The radial sensory nerve branches suture material.9,10,12 The suture Other techniques have been rec- are isolated and protected. Be- may be tied over a button on the ommended for evaluation of these neath the subcutaneous tissue and radial side of the MCP joint with a injuries, such as stress radiography, a layer of loose adventitia, the pullout suture technique.9,10 Alter- arthrography, and magnetic reso- proximal edge of the adductor natively, the suture can be tied nance imaging. In my opinion, aponeurosis is identified. If the lig- directly over bone on the proximal these tests add unnecessary cost ament is ruptured and displaced, phalanx to achieve a tighter repair, and provide little additional infor- its distal end will be seen in cross leaving no exposed suture. Some

Vol 5, No 4, July/August 1997 227 Ulnar Collateral Ligament Injuries of the Thumb

A B

Fig. 4 A, Recommended S-shaped skin incision for surgical repair. B, Surgical exposure reveals a Stener lesion (arrow). Large arrow- head indicates the adductor aponeurosis; small arrowhead indicates edematous end of ruptured ligament. researchers have reported good and active MCP joint motion is Complications results after sewing the ligament to begun. A hand-based splint immo- the periosteal tissues at the base of bilizing the MCP joint is applied at Even if the radial sensory nerve is the proximal phalanx.4,11,13,14 In my the time of cast removal and is isolated and protected during the opinion, the particular suture tech- maintained for 2 weeks. Unre- procedure, a neurapraxia may nique employed is not of impor- stricted usage is allowed at 3 ensue. This usually resolves spon- tance provided the soft-tissue months. taneously. Stiffness of the MCP repair is anatomic and the orienta- joint and interphalangeal joint fre- tion of the ligament is restored. quently occurs, but is usually not a The proper collateral ligament Results functional problem and tends to should be secured to its normal improve with time. insertion site on the palmar and Accurate early diagnosis is one of A more troublesome complica- ulnar aspect of the base of the the most important factors deter- tion is persistent instability. This proximal phalanx. The ulnar cor- mining functional outcome. In outcome is uncommon,9,17 but may ner of the palmar plate may also thumbs with partial ligament occur despite a technically good need reattachment. Subsequently, injuries, nonoperative treatment by repair. Chronic instability mani- the accessory collateral ligament is immobilization will yield a stable fests itself clinically as pain during sewn to the palmar plate volarly painless thumb with near-normal pinch and grasp as well as weak- and distally. The dorsal capsule is motion in the vast majority of ness. If chronic instability is left then sutured. The adductor apo- cases. In thumbs with a complete untreated, secondary arthritic neurosis should be repaired with rupture treated operatively within changes may occur. an absorbable suture. 3 weeks of the injury, a good to After skin closure, a thumb spica excellent result can be expected in splint is applied. Care should be more than 90% of cases, regardless Treatment of Chronic taken to mold it well about the of the technique of ligament Instability MCP joint so that the interpha- repair.9,10,15,16 Pain and stiffness langeal joint can be left free. can be expected to be mild or The most common causes of chron- Motion of the interphalangeal joint absent, and pinch and grip strength ic instability of the thumb MCP is encouraged in the postoperative will be near normal. The rate of joint after an acute rupture are fail- period to prevent extensor tendon return to former activities, includ- ure of the patient to seek treatment adhesions and stiffness. The cast ing recreational sports, has been and missed diagnosis. The longer and pin are removed after 4 weeks, reported to be as high as 96%.9 an untreated complete rupture

228 Journal of the American Academy of Orthopaedic Surgeons Philip Heyma n, MD

exists, the less likely it is that an In long-standing cases of ulnar of partial ligament injuries with anatomic reconstruction will be collateral ligament instability, sec- cast or splint immobilization will successful.10,18 Some surgeons ondary arthritic changes may be result in a stable and painless have reported success with recon- seen. In this setting, arthrodesis thumb. Valgus laxity greater than struction employing the remaining should be strongly considered. 30 degrees or more than 15 degrees capsuloligamentous tissues.13,14,19 Arthrodesis should also be consid- more than in the noninjured thumb Others have reported good results ered for manual laborers. It should with the MCP joint in extension is with a delayed primary repair aug- be noted that in some noninjured an indication for operative man- mented by dynamic transfer of the thumbs, a normal arc of motion agement. Examination should be adductor pollicis from the ulnar may be as little as 5 degrees.6,7 For carried out with the use of local sesamoid to the base of the proxi- this reason, arthrodesis does not anesthetic. Stress testing should be mal phalanx.5 Ligament recon- lead to much impairment if motion carried out even if there is an avul- struction can also be carried out of the interphalangeal joint and sion fracture from the base of the with a free tendon graft woven carpometacarpal joint is preserved. proximal phalanx. The essential through the metacarpal neck and components of the surgical repair the base of the proximal pha- are anatomic reconstruction of the lanx.15,18 In most cases, the pal- Summary ulnar collateral ligament, palmar maris longus is used, but when plate, and dorsal capsule, followed that is not available, the plantaris, Successful management of acute by protection in a cast or splint. a toe extensor, a slip of the abduc- injuries of the ulnar collateral liga- The functional results of operative tor pollicis longus, or a portion of ment of the thumb MCP joint pre- treatment are excellent, resulting in the flexor carpi radialis can be vents the sequelae of instability a stable and painless thumb in the employed.17 and pain. Nonoperative treatment vast majority of cases.

References

1. Campbell CS: Gamekeeper’s thumb. J ment in soft-tissue injury of the thumb head of the first metacarpal. J Bone Bone Joint Surg Br 1955;37:148-149. metacarpophalangeal joint: With Joint Surg Am 1961;43:541-546. 2. Minami A, An KN, Cooney WP III, a clinical study of the normal range 14. Strandell G: Total rupture of the ulnar Linscheid RL, Chao EYS: Ligamen- of motion in one thousand thumbs collateral ligament of the metacar- tous structures of the metacarpopha- and a study of post mortem findings pophalangeal joint of the thumb: langeal joint: A quantitative anatomic of ligamentous structures in relation to Results of surgery in 35 cases. Acta study. J Orthop Res 1984;1:361-368. function. J Bone Joint Surg Am 1968;50: Chir Scand 1959;118:72-80. 3. Heyman P, Gelberman RH, Duncan K, 439-451. 15. Gerber C, Senn E, Matter P: Skier’s Hipp JA: Injuries of the ulnar collater- 8. Carr D, Johnson RJ, Pope MH: Upper thumb: Surgical treatment of recent al ligament of the thumb metacar- extremity injuries in skiing. Am J injuries to the ulnar collateral ligament pophalangeal joint: Biomechanical and Sports Med 1981;9:378-383. of the thumb’s metacarpophalangeal prospective clinical studies on the use- 9. Derkash RS, Matyas JR, Weaver JK, et joint. Am J Sports Med 1981;9:171-177. fulness of valgus stress testing. Clin al: Acute surgical repair of the skier’s 16. Saetta JP, Phair IC, Quinton DN: Orthop 1993;292:165-171. thumb. Clin Orthop 1987;216:29-33. Ulnar collateral ligament repair of the 4. Stener B: Displacement of the rup- 10. Smith RJ: Post-traumatic instability of metacarpo-phalangeal joint of the tured ulnar collateral ligament of the the metacarpophalangeal joint of the thumb: A study comparing two meth- metacarpo-phalangeal joint of the thumb. J Bone Joint Surg Am 1977;59: ods of repair. J Hand Surg [Br] 1992;17: thumb: A clinical and anatomical 14-21. 160-163. study. J Bone Joint Surg Br 1962;44: 11. Smith MA: The mechanism of acute 17. Glickel SZ, Malerich M, Pearce SM, 869-879. ulnar instability of the metacarpopha- Littler JW: Ligament replacement for 5. Neviaser RJ, Wilson JN, Lievano A: langeal joint of the thumb. Hand chronic instability of the ulnar collater- Rupture of the ulnar collateral liga- 1980;12:225-230. al ligament of the metacarpopha- ment of the thumb (gamekeeper’s 12. Abrahamsson SO, Sollerman C, langeal joint of the thumb. J Hand Surg thumb): Correction by dynamic repair. Lundborg G, Larsson J, Egund N: [Am] 1993;18:930-941. J Bone Joint Surg Am 1971;53:1357-1364. Diagnosis of displaced ulnar collateral 18. Helm RH: Hand function after injuries 6. Palmer AK, Louis DS: Assessing ulnar ligament of the metacarpophalangeal to the collateral ligaments of the meta- instability of the metacarpophalangeal joint of the thumb. J Hand Surg [Am] carpophalangeal joint of the thumb. J joint of the thumb. J Hand Surg [Am] 1990;15:457-460. Hand Surg [Br] 1987;12:252-255. 1978;3:542-546. 13. Kaplan EB: The pathology and treat- 19. Isani A, Melone CP Jr: Ligamentous 7. Coonrad RW, Goldner JL: A study of ment of radial subluxation of the injuries of the hand in athletes. Clin the pathological findings and treat- thumb with ulnar displacement of the Sports Med 1986;5:757-772.

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