Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament

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1 This is an enhanced PDF from The Journal of Bone and Joint Surgery The PDF of the article you requested follows this cover page. Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament JE Conway, FW Jobe, RE Glousman and M Pink J Bone Joint Surg Am. 1992;74: This information is current as of December 1, 2010 Reprints and Permissions Publisher Information Click here to order reprints or request permission to use material from this article, or locate the article citation on jbjs.org and click on the [Reprints and Permissions] link. The Journal of Bone and Joint Surgery 20 Pickering Street, Needham, MA

2 ( opvright I ))2 by iii Jour,,,l of!topsc atadjoipit Sur5 erv, Isuorf)oraI( (I Medial Instability of the Elbow in Throwing Athletes TREATMENT BY REPAIR OR RECONSTRUTION OF THE ULNAR COLLATERAL LIGAMENT* RY JOhN F. ( ONWAY. M.D.t. FRANK W. JOBE. M.D41. RONALD E. GLOUSMAN, M.D.*. AND MARILYN PINK. MS., P.T4. INGLEWOOD. CALIFORNIA lfll estigatioll performed at tile Kerlan-Johe Orthopaedic Clinic (111(1 i/ic Biomec/ia,iics Laboratory, Centinela Hospital Medical Center, Inglevs ood ABSTRACT: From September 1974 to December 1987, seventy-one patients were operated on for valgus instability ofthe elbow.the average length of follow-up ofsixty-eight patients (seventy operations) was 6.3 years (range, two to fifteen years). At the operation, a torn or incompetent ulnar collateral ligament was found. Fourteen patients had a direct repair of the ligament, and fifty-six had a reconstruction ofthe ligament using a free tendon graft. The result was excellent or good in ten patients in the repair group and in forty-five (80 per cent) in the reconstruction group. Seven of the fourteen patients who had a direct repair returned to the previous level of participation in their sport. Of the fifty-six who had a reconstruction, thirty-eight (68 per cent) returned to the previous level of participation. Twelve of the sixteen major-league baseball players who had a reconstruction as the primary operation (no previous operation on the elbow) were able to return to playing major-league baseball, and two of the seven major-league players who had a direct repair returned to playing major-league baseball. Previoils operations on the elbow decreased the chance of returning to the previous level of sports participation (p = 0.04). Fifteen patients had postoperative ulnar neuropathy. This was transient in six patients, only one of whom was unable to return to the previous level of sport. The other nine patients had an additional operation for the neuropathy; four were able to return to the previous level of sport. The primary constraint resisting a valgus stress on the elbow is the anterioroblique band ofthe ulnar collateral ligament 533 (Fig. 1 ). Throwing a baseball or a jayelm, or a similar activity, causes enormous valgus stresses on the elbow during the late-cocking and acceleration phases ofthrowing (Fig. 2), and these stresses may exceed No benefits in any form have been received or will he received from a commercial party related directly or indirectly to the subject of this article. No funds were received in support of this study. torthopedic Specialty Associates. Suite Pennsylvania Avenue, Fort Worth. Texas J3iomechanics Laboratory. Centinela Hospital Medical Center. 555 East Hardy Street. Inglewood. California Please address requests for reprints to Dr. Johe. Kerlan-Johe Orthopaedic Clinic, 501 East Hardy Street, Inglewood, California the tensile strength of the ligament5. Repetitive microtrauma from overloading ofthe ligament in tension causes inflammation and microscopic tears in the ligament. As a result, the ligament is weakened, becomes attenuated, and occasionally ruptures 2. Sport-related injury of the ulnar collateral ligament occurs most commonly in javelin throwers and baseball Ant. Transverse bundle FI;. 1 Post. bundle Drawing of the medial view of the right elbow, showing the ulnar collateral-ligament complex. pitchers 237. Although the resulting instability may not impair the activities of daily living, it may preclude participation in throwing sports. Rest and non-operative management soon after the onset of symptoms may arrest the progression to instability and allow the athlete to return to competition2. When non-operative management fails and a well motivated athlete wants to continue to participate in sports, we have used two operations: repair or reconstruction of the ulnar collateral ligament. Until a reconstructive procedure using an autologous tendon graft was developed, we performed a direct repair ofthe remaining ligament 2. Currently, we usually perform a reconstruction, although direct repair of an acutely torn ligament may be appropriate in some patients. The purpose of this study was to assess the results of repair and of reconstruction of the ulnar collateral ligament in the throwing athlete and to identify factors that affect the results. VOL. 74-A, NO. I. JANtJARY

3 68 J. E. CONWAY. F. w. JOBE, R. E. GLOUSMAN, AND MARILYN PINK I I I I I I FIG. 2 The phase of acceleration of a baseball pitch. Materials and Methods From September 1974 to December 1987, seventyone patients who had valgus instability of the elbow, as determined by history and physical findings, had an operation on the elbow. There were sixty-seven baseball players, threejavelin throwers, and one tennis player. The presence of a torn or incompetent ulnar collateral ligament of the elbow was confirmed in all patients at the time of the operation. Sixty-eight (96 per cent) of the seventy-one patients were located for follow-up evaluation. The sixty-eight patients were divided into two groups: those who had had a direct repair of the ligament (fourteen patients) and those who had had a reconstruction using a free autologous tendon graft (fifty-six patients). Two patients in the reconstruction group had had a poor result after a previous direct repair of the ligament and thus were included in both groups. All sixty-eight patients were operated on by one of us (E W. J.), and the patients were followed for an average of 6.3 years (range, two to fifteen years). The medical records of all of the patients were reviewed; a physical examination was done and regular and valgus-stress radiographs were made at a follow-up evaluation for forty-one (60 per cent) of the sixty-eight patients. For six of the forty-one patients, an orthopaedist in their area performed the examination and arranged for radiographs, at our request. Valgus-stress radiographs in these six patients were made using manual stress. Thirty-five patients were evaluated at our institution, and for them the valgus-stress radiographs were standardized with the use of the Telos Stress Device (Austin and Associates, Fallston, Maryland) with a force of sixty-nine newtons (seven kiloponds) applied over the lateral epicondyle of the elbow. For this test, the elbow was flexed to 30 degrees, the wrist and humerus were immobilized, and the shoulder was placed in abduction and external rotation. The other twenty-seven patients (40 per cent) were interviewed extensively on the telephone. The diagnostic evaluations, as well as the non-operative management before the repair or reconstruction, were the same in the two groups. Non-operative treatment had consisted of an initial period of rest and oral administration of non-steroidal anti-inflammatory medication. A supervised program of exercises for stretching and strengthening of all of the muscles about the elbow began after the acute inflammation had ended, and appropriate modalities of physical therapy (including contrast baths, phonophoresis, and electrical stimulation) were used. Repair Group All fourteen patients in the repair group were male baseball players: thirteen pitchers and one infielder. The mean age at the time of the operation was 26.5 years (range, nineteen to thirty-eight years). At the time of the injury, seven had been in a major league (one of the two top professional baseball leagues in the United States [the American and National Leagues]); three, in a minor league (a league that prepares players for the major league); and four, in college. The mean age when the athletes had started playing organized baseball was seven years (range, four to ten years old). Six had had pain in the elbow in the past but not while playing in Little League (for players who are six to twelve years old). Five patients had had a previous injury to the elbow that had temporarily limited activity, but between the time of the previous injury and when they were first seen for instability of the elbow, there had been symptom-free intervals that had lasted one to seven years. No patient had had a previous operation on the elbow. Ten patients reported that the injury had occurred during a single throw. THE JOURNAL OF BONE AND JOINT SURGERY

4 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 69 FIG. 3 Drawing demonstrating the technique for performing the test for instability of the elbow. (See the text for a detailed description.) The mean time from the injury of the elbow to the operation was 7.6 months (range, 0.5 to thirty months). Before the repair, six of the fourteen patients had had one or more steroid injections on the medial side of the elbow, seven had had ulnar-nerve symptoms, and nine had lost some extension of the elbow. The diagnosis of a torn or incompetent ulnar collateral ligament was based on the history and findings on routine physical examination, by valgus-stress testing, and occasionally by evidence of instability that was demonstrated on stress radiographs. For the valgus-stress test, the arm of the standing patient was positioned in the coronal plane of the body, with the shoulder in abduction and external rotation and the forearm supinated. The elbow was flexed 30 degrees to reduce the constraints provided by the configurations of the bones of the elbow. The patient s hand was held between the examiner s arm and chest wall; this left one of the examiner s hands free to apply valgus stress on the elbow and the other hand free to palpate the medial joint line beneath the ulnar collateral ligament (Fig. 3). Valgus-stress testing demonstrated instability in eight of the fourteen elbows, failed to show instability in four, and was not documented in two of the clinical records. All but two of the fourteen patients had pain on palpation over the ulnar collateral ligament. The two patients who had no pain had not thrown a ball for several months. One patient had no pain on palpation over the ulnar collateral ligament and no apparent instability on valgus-stress testing; the diagnosis of an incompetent ligament was based on the history of persistent pain in the medial aspect of the elbow during the acceleration phase of throwing, despite extensive non-operative treatment. All fourteen patients had a direct repair of the antenor bundle of the ulnar collateral ligament without augmentation with an autologous graft. Two patients had a transposition of the ulnar nerve: one at the time of the repair and the other, twenty-two months after the repair. Two patients had d#{233}bridement of osteophytes on the posteromedial margin of the olecranon. Three patients were found to have calcification within the ligament, but after excision of these deposits there appeared to be enough normal ligament left for a satisfactory direct repair. Reconstruction Group Of the fifty-six patients in the reconstruction group, fifty-five were men and one was a woman. Fifty-two played baseball; forty-five were pitchers, three were catchers, three were infielders, and one was an outfielder. The two patients who were included in both groups were pitchers. At the time of the injury, twenty were in a major league; eighteen, in a minor league; ten, in college; and four, in high school. Of the other four patients, three were competitive javelin throwers (one Olympic and two collegiate athletes), and one competed professionally in tennis after having quit major-league baseball because of problems with the elbow. The mean age when the baseball players had started playing organized baseball was eight years (range, six to eighteen years). Thirty patients (54 per cent) had had previous pain in the elbow, but only two had had symptoms while playing in Little League. The mean age of the patients at the time of the reconstruction was 23.7 years (range, fifteen to twentyfour years); for the major-league baseball players, the mean age was 27.2 years (range, nineteen to forty-four years). VOL. 74.A, NO. I. JANUARY 1992

5 70 J. E. CONWAY, F. W. JOBE, R. E. GLOUSMAN. AND MARILYN PINK Twenty-three (41 per cent) of the fifty-six patients had had an injury of the elbow before the injury that led to the reconstruction ofthe ulnar collateral ligament.the patients had limited their activities temporarily, but thereafter they had had symptom-free intervals that had lasted one to twenty-seven years before the most recent injury occurred. In nine patients (16 per cent), one to five previous operations had been done on the disabled elbow, six to ninety-six months before the reconstruction of the ligament. The previous operations included transposition of the ulnar nerve in four patients, repair of the ulnar collateral ligament in two, arthroscopic removal of a loose body from the elbow in one, diagnostic arthroscopy in five, and d#{233}bridement of osteophytes around the elbow in four. Thirty-four patients (61 per cent) recalled that the injury had occurred during a single throw; the other twenty-two patients did not remember any such sudden event. The mean length of time between injury and reconstruction of the ligament was 12.4 months (range, 0.5 to sixty-four months). Before reconstruction, twenty-five patients (45 per cent) had had one to ten steroid injections into the medial side of the elbow, twenty-three (41 per cent) had had ulnar-nerve symptoms,and thirty-eight (68 per cent) had lost 2 to 35 degrees of extension of the elbow. Valgus-stress testing demonstrated instability in thirty-three elbows, failed to show instability in fourteen, and was not documented in nine of the clinical records. All but two patients had pain on palpation over the ulnar collateral ligament. These two had not thrown a baseball for several months before the physical examination. One patient had no pain on palpation over the ulnar collateral ligament and no apparent instability on valgus-stress testing; the diagnosis of an incompetent ligament was based on the presence of calcification at the site of the ligament on radiographs and a history of persistent pain in the medial aspect of the elbow during the acceleration phase of pitching. All of the fifty-six patients had a reconstruction of the anterior bundle of the ulnar collateral ligament with use of a free autologous tendon graft. The presence of a palmaris tendon was determined preoperatively: when it was present, it was used for the graft, and when it was absent, an incision was made for the identification and use of a plantaris tendon. In fifteen patients (27 per cent), the graft was taken from the ipsilateral palmaris longus tendon; in thirty (54 per cent), from the contralateral palmaris longus tendon; in seven (13 per cent), from the plantaris tendon; and in one (2 per cent), from the extensor tendon of the fourth toe. In the three remaining patients (5 per cent), the plantaris tendon was absent at exploration, and a strip of tendon, three millimeters wide and fifteen centimeters long, was taken from the medial margin of the Achilles tendon. In nine patients (16 per cent), osteophytes were removed from the posteromedial margin of the olecranon, and in twenty-four (43 per cent), calcium deposits in the remaining portion of the ligament were excised. An anterior submuscular transposition of the ulnar nerve, as described by Learmonth20, was performed in all but one of the fifty-six patients. The exception was the first patient who was treated by reconstruction. Symptoms of ulnar neuritis developed in this patient postoperatively, and the nerve was transposed anteriorly three months after the reconstruction. Operative Technique All procedures are performed under general endotracheal anesthesia, with a pneumatic tourniquet on the arm. The patient is supine, and the arm is abducted to the V FIG. 4 Drawing of the medial aspect of the right elbow, illustrating the repair of a distal tear of the ulnar collateral ligament. Bunnell Sutures have been placed through drill-holes in the ulna. THE JOURNAL OF BONE AND JOINT SURGERY

6 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 71 FIG. 5 Drawing of the medial aspect of the right elbow before reconstruction, showing the remnant of the ulnar collateral ligament and proper placement of the hone-tunnels in the ulna and in the medial humeral epicondyle. The ulnar nerve is gently retracted posteriorly and can be seen in the lower part of the drawing. side on an arm-board. A ten-centimeter incision, centered over the medial epicondyle, is used to expose the ligament and elbowjoint,with care to protect the sensory nerves passing to the medial aspect of the forearm and the ulnar nerve in its groove. If there has been a previous transposition of the ulnar nerve (as in four patients in this study), the nerve is dissected free and is protected before the ulnar collateral ligament is exposed. For this exposure, a longitudinal split is made in the flexor aponeurosis and the underlying muscles in line with the fibers where they arise from the medial epicondyle. In all of the patients in the repair group, adequate normal-appearing ligament remained and a direct repair was performed. Four ligaments had pulled off the bone and were reattached by means of sutures through drillholes (Fig. 4). The others were repaired end-to-end or were imbricated. In all of the fifty-six patients in the reconstruction group, an inadequate amount of normal ligament remained to perform a primary repair, and reconstruction with a tendon graft was performed. For the reconstruction, additional exposure is obtamed by transection of the tendinous origin of the flexor-pronator muscle bundle; a stump of tendon is left on the epicondyle for later reattachment. The tendon and muscle are reflected distally, leaving a thin layer of musdc fibers attached to the bone and the remaining part of the ulnar collateralligament. Any calcification within the ligament and soft tissues is removed. The ulnar nerve is located proximally and is released A tendon graft (such as the palmaris longus tendon) is threaded into the tunnels in the medial epicondyle and in the ulna in a figure-of-eight configuration; the ends are pulled into the tunnels. FIG. 6 VOL. 74.A, NO. I. JANUARY 1992

7 72 J. E. CONWAY, F. W. JOBE, R. E. GLOUSMAN, AND MARILYN PINK FIG. 7 The ulnar nerve is now passed over the tendon graft and transposed anteriorly under muscle. from the cubital tunnel. If present, the arcade of Struthers, which is a fascial connection passing over the ulnar nerve from the medial head of the triceps to the medial intramuscular septum, is identified and released. The ulnar nerve is then dissected free and is carefully mobilized: proximally from the level of the arcade of Struthers and distally to the interval between the two heads of the flexor carpi ulnaris. A loop of 6.4-millimeter Penrose drain is then placed about the nerve to protect it and to manipulate it during mobilization. The articular branches of the nerve are sacrificed, but its motor branches to the flexor carpi ulnaris muscle are preserved.the medial intermuscular septum in the brachium is excised proximally for a distance of five to eight centimeters, so that the transposed nerve will not be in contact with the edge of the intermuscular septum - now a potential site of impingement. Any loose bodies in the posterior compartment of the elbow and any osteophytes on the posteromedial margin of the olecranon are removed through a posteromedial arthrotomy. Next, the sites of attachment of the anterior part of the ulnar collateral ligament on the humerus and ulna are identified, and a 3.2-millimeter drill-bit, a slow-speed drill, and a drill-guide are used to make tunnels in the medial epicondyle and proximal end of the ulna (Fig. 5). The tunnels are placed so that the graft will be secured at the original attachment sites of the anterior bundle of the ulnar collateral ligament and will not rub on the epicondyle or on any excrescences on the ulna. The tendon graft is passed through these tunnels to form a figure-of-eight (Fig. 6) and act as a functional substitute for the anterior bundle of the ulnar collateral ligament. With the forearm supported to prevent any valgus stress on the elbow, the graft is pulled taut and is sutured to itself. Any remnants of the original ligament are then sutured into the graft for additional strength. Finally, the ulnar nerve is transferred anteriorly so that it will pass over the tendon graft (Fig. 7); care is taken to confirm that there is no impingement on the nerve or tethering of it in its transposed position. Absorbable sutures are placed so that they extend from the stump of the origin of the flexor-pronator tendon to the portion distally that has been released from the stump. This is done under direct vision, and no sutures are tied until all have been placed. After the sutures have been tied, the elbow is moved through a full range of motion and is subjected to a gentle valgus stress to test the reconstruction. The tourniquet is then released, and hemostasis is obtained before closure of the wound. Postoperative Care and Rehabilitation The same postoperative program is used for both the repair group and the reconstruction group. The elbow is immobilized in a posterior splint for ten days with the wrist left free; the elbow is in 90 degrees of flexion and the forearm is in neutral rotation. Gentle hand-grip exercises are begun as soon as the patient is comfortable. Active range-of-motion exercises for the elbow and shoulder are started at ten days, and exercises to strengthen the muscles of the wrist and forearm are initiated at four to six weeks. After six weeks, elbowstrengthening exercises are begun, but valgus stress on the elbow is avoided until four months postoperatively. The next phase of rehabilitation is adapted according to the sport of the patients. Shoulder exercises are continued throughout the postoperative program. At four months, the pitchers are allowed to toss a ball for a distance of about nine to twelve meters (thirty to forty feet) two to three times a week for ten to fifteen minutes, but this is done without any wind-up. After five months, the patients begin tossing the ball a distance of eighteen meters (sixty feet) and continue progressive strengthening exercises. At six months, they start lobbing the ball for a distance of eighteen meters (sixty feet) using an easy wind-up, and thereafter do the exercises and ball-lobbing on alternate days. At seven months, they are allowed to throw the ball from the mound (the normal location of the pitcher in a baseball THE JOURNAL OF BONE AND JOINT SURGERY

8 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 73 NO. INJURIES (P1-27) Bar graph showing the distribution, by month, of injuries in the twenty-seven major-league pitchers. The baseball season begins in April. 8 game) at one-half full speed for a horizontal distance of eighteen meters (sixty feet, the distance to home plate in a baseball game) and are allowed to increase the duration of the throwing sessions to twenty-five minutes. During the eighth and ninth months, depending on the progress, they are allowed to pitch at 75 per cent of their maximum speed. From ten months on, they continue to throw at 75 per cent of their maximum speed, starting from the wind-up position and focusing on the body mechanics of throwing. However, throwing sessions still do not exceed twenty-five minutes. Over the next two months, the duration of the throwing sessions and the velocity of the throw are gradually increased until the patient can pitch a simulated game. Pitching in competition is permitted at twelve months if the following criteria have been met: there is no pain while throwing, the strength of the forearm muscles has returned to normal, the elbow and shoulder have normat range of motion and strength, and over-all normal throwing balance, rhythm, and coordination have been re-established. Initially, pitchers are allowed to pitch only three innings at one time and are discouraged from returning to a rotation in which they pitch more frequently than every seven days. All pitchers are encouraged not to resume the regular rotation schedule until eighteen months after repair or reconstruction. General aerobic exercises are stressed throughout the program. The rehabilitation program for the three javelin throwers and the one tennis player was adapted for their specific sports. Results We studied the seasonal occurrence of the injuries, the relationship of preoperative pain to the phase of the pitching motion, the operative findings, and the range of motion of the elbow and the radiographic findings at follow-up. We also assessed the results in terms of the ability to return to competition. Finally, we considered the possible effects ofsuch factors as previous operations on the elbow, the type of procedure, the position played in baseball, the mode of onset of disability of the elbow, the source of the graft utilized in the reconstructive procedure, and the duration of rehabilitation before return to competition. Seasonal Occurrence Thirty-one (48 per cent) of the sixty-four baseball players reported that the injury had occurred during spring training or during the first two months of the regular season. In the major-league players, the injuries occurred throughout the season, but ten (37 per cent) of these twenty-seven injuries had occurred during the first two months of the regular season (Fig. 8). However, there was no statistically significant difference between the frequencies of injuries early (April and May), halfway (June and July), and late (August and September) in the season (chi-square test, p = 0.20). Relationship ofpain and Phase of Throwing Many of the patients had pain during more than one phase of throwing (Fig. 9). Pain associated with throwing the baseball or javelin or with serving in tennis occurred during late cocking in 9 per cent of the patients, acceleration in 85 per cent, and follow-through in 25 per cent. Twenty-four (35 per cent) of the sixty-eight patients had severe pain when the ball orjavelin was released or when the racquet hit the ball. (Because pain occurred during more than one phase in some patients, the percentages total more than 100 per cent.) VOL. 74-A, NO. I. JANUARY 1992

9 74 J. E. CONWAY, F. W. JOBE. R. E. GLOUSMAN. AND MARILYN PINK 100 PERCENT LATE COCKING ACCELERATION AT BALL RELEASE THROWING PHASE FIG. 9 FOLLOW THRU Bar graph showing the phases of the throwing motion and the proportion of patients who had pain in each phase. Many patients had pain during more than one phase; some noted that pain was the worst at the time of release of the ball. Operative Findings In two patients, reconstruction was done after repair had failed, so sixty-eight patients had seventy operations. At the time of the exploration, the medial articular surfaces and the ulnar collateral ligament were clearly visualized in order to assess instability accurately. Medial instability during valgus stress was confirmed on exploration in all seventy elbows. The ligament was avulsed distally from the ulna in seven (lopercent) ofthe seventy elbows and proximally from the medial epicondyle of the humerus in two (3 per cent). In the remaining sixty-one elbows, there was a tear in the mid-substance or scar tissue and calcification at the site of the old tear. In twenty-seven (39 per cent) of the seventy elbows, there was calcification within the ligament, and in eleven patients (16 per cent), a large osteophyte on the posteromedial margin of the olecranon was debrided. Ten of the eighteen elbows in which there had been no clinically detectable instability during preoperative valgus-stress testing were found to have calcification within the ligament at the operation. When this calcification was removed, valgus instability could be demonstrated. In the remaining eight of the eighteen elbows, dense scar tissue had replaced the ligament so that no normal ligamentous tissue remained. A rupture in the substance of the flexor-pronator muscle mass near its origin on the medial epicondyle was seen in nine (13 per cent) of the seventy elbows. Postoperative Physical Findings Of the sixty-eight patients, twenty-seven (40 per cent) were not available for examination at the time of this study. The remaining forty-one patients (60 per cent) were examined in our office or by a physician in the patient s local area. Of the forty-one, eight had had direct repair and thirty-four had had reconstruction. (One patient was included in both groups.) The range of motion of the elbow before the injury was unknown; therefore, the deficit in range of motion was calculated from the basis of a 0-degree position. Extension to 0 degrees was not possible for four elbows in the repair group (extension to 2, 2, 5, and 9 degrees) or for seventeen elbows in the reconstruction group (range, 2 to 25 degrees). Two patients in the repair group and nine in the reconstruction group had a loss of extension of the elbow of 5 degrees or more. Six patients in the reconstruction group had a loss of extension of more than 10 degrees, but four of the six were able to return to the previous level of competition. Postoperative Radiographic Findings Standard anteroposterior and lateral radiographs of the elbows were made after the operation for seven patients in the repair group and for thirty-five (63 per cent) of the patients in the reconstruction group. An osteophyte on the posteromedial margin of the olecranon was seen in more than half of the patients, but the osteophyte was projected more than five millimeters on any radiograph of the elbow in only one patient in the repair group and five patients in the reconstruction group. Formation of minor spurs along the medial rim of the trochlear notch of the ulna was seen frequently. Soft-tissue calcification was evident in the proximal part of the ulnar collateral ligament or in the tendon graft in one of the seven patients in the repair group and sixteen (46 per cent) of the thirty-five patients in the reconstruc- THE JOURNAL OF BONE AND JOINT SURGERY

10 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 75 PERCENT EXCELLENT GOOD FAIR POOR RESULT FIG. 10 Bar graph of the results (in percentages) of reconstruction when no previous operation had been done (forty-seven patients) compared with the results after reconstruction in patients who had had a previous operation (nine patients). tion group. No apparent adverse effect of the calcification was identified. Valgus-stress radiographs of the elbows were made for six of the fourteen patients in the repair group and twenty-nine (52 per cent) of the fifty-six in the reconstruction group. The average opening of the cartilage space on the stress radiographs was three millimeters (range, one to five millimeters) in the repair group and two millimeters (range, 0.5 to five millimeters) in the reconstruction group. Of the patients who were able to return to the preinjury level of participation in sports, stress radiographs showed a mean opening of three millimeters (range, two to four millimeters) in the repair group and two millimeters (range, 0.5 to three millimeters) in the reconstruction group. However, stress radiographs of the contralateral elbows were not made for comparison. Result-Rating Scale The results of treatment were graded as excellent, I OO PERCENT RESULT FIG. 11 Bar graph of the results (in percentages) after direct repair of the ulnar collateral ligament (fourteen patients) compared with the results after reconstruction (fifty-six patients). VOL. 74-A, NO. I. JANUARY 1992

11 76 J. E. CONWAY. E W. JOBE, R. E. GLOUSMAN, AND MARILYN PINK good, fair, and poor on the basis of return to competition. The result was excellent if the patient was able to compete at the same or a higher level than before the injury for more than twelve months, as good if the patient was able to compete at a lower level for more than twelve months or was able to throw in daily batting practice, as fair if the patient was able to play regularly at a recreational level, and as poor if the patient was unable to play. However, one of the patients in the reconstruction group was not classified according to this grading system. The patient returned to baseball at the previous level of competition for three months, at which time pain in the shoulder was associated with throwing. He retired from baseball after playing for less than one year. Because he had no pain in the elbow associated with throwing and was competing at the same level as he had before the injury, we classified the result as excellent. reconstruction group, forty-seven patients had had no previous operation; in thirty-five (74 per cent), the result was excellent (the result was good or excellent in 83 per cent). Of the nine patients who had had a previous operation, only three had an excellent result (55 per cent had a good or excellent result) (Fig. 10). This difference was significant (chi-square test with Yates correction, p = 0.04). Type of Procedure For the fourteen patients in the repair group, the result was excellent in seven, good in three, fair in two, and poor in two. For the fifty-six patients in the reconstruction group, the result was excellent in thirty-eight (68 per cent), good in seven (13 per cent), fair in eight (14 per cent), and poor in three (5 per cent) (Fig. 1 1). Excluding the patients who had had previous operative treat- PERCENT RESULT FIG. 12 Bar graph comparing the results (in percentages) in major-league baseball players. Seven players had direct repair and twenty had reconstruction. Of the seventy operations, the result was excellent in forty-five (64 per cent), good in ten (14 per cent), fair in ten (14 per cent), and poor in five (7 per cent). Five of the ten patients who had a fair result had no problems with the elbow but stated that they chose not to return to the previous level of competition in order to pursue other goals. Of the remaining five patients who had a fair result, three had pain in the elbow when they threw and two did not. All five patients who had a poor result had pain while throwing. Possible Effects of Various Factors Previous Operative Treatment None of the fourteen patients in the repair group had had an operation on the elbow before the repair. In the ment, there was a 24 per cent difference in the functional outcome between the two groups (74 per cent of the patients in the reconstruction group who returned to the previous level of competition minus 50 per cent in the repair group who returned), but the difference was not significant (chi-square test with Yates correction, p = 0.16). If just the twenty-seven major-league players are considered, excellent results were obtained in two of the seven patients in the repair group and in thirteen (65 per cent) of the twenty patients in the reconstruction group (Fig. 12). The difference in the proportion of excellent results in the two groups was not significant (chi-square test with Yates correction, p = 0.22). Of the sixteen major-league players in the reconstruction group who had not had a previous operation, twelve had an excel- THE JOURNAL OF BONE AND JOINT SURGERY

12 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 77 PERCENT RESULT FIG. 13 Bar graph of the results (in percentages) when the onset of symptoms was sudden (thirty-four patients) compared with those when the onset was more insidious (twenty-two patients). PERCENT RESULT FIG. 14 Bar graph comparing the results (in percentages) of different graft materials. In fifteen patients. the graft came from the ipsilateral palmaris longus (Ipse EL.), in thirty the graft came from the contralateral palmaris longus (Contra P.L.), and in eleven the graft came from another site (Other) (see text). lent result (fifteen had a good or excellent result). Of the twenty major-league baseball players in the reconstruction group, ten (50 per cent) were still playing in a major league. Two of the eighteen minor-league players who had had reconstruction had advanced to play in a major league. At the latest evaluation, the mean time that a patient remained in a major league after successfully returning was 5.8 years (range, three to twelve years). Sport The result was excellent in the one professional tennis player and the three javelin throwers. Among the fifty-two baseball players in the reconstruction group, forty-five were pitchers, six were infielders, and one was an outfielder. With these small numbers, significant differences in the ability to return to baseball on the basis of the position played would not be discernible statistically. However, twenty-eight (62 per cent) of the forty-five pitchers had an excellent result, and six of the seven baseball players who were not pitchers had an excellent result (chi-square test with Yates correction, p = 0.43). Among VOL. 74.A, NO. 1. JANUARY 1992

13 78 J. E. CONWAY, F W. JOBE, R. E. GLOUSMAN, AND MARILYN PINK POSTOPERATIVE TABLE I COMPLICATIONS Preoperative Residual Previous Ulnar-Nerve Additional Ulnar-Nerve Case Operation Symptoms Complications Operations Symptoms Results Reconstruction No No Transient ulnar- No Excellent nerve paresth. (11 mos.) 2 No No Transient ulnarnerve paresth. (1 mo.) 3 Yes No Ulnar neuropathy (late onset) 4 Yes Yes Transient ulnarnerve paresth. (3mos.) 5 No No Sensory nerve neuroma ulnar- transpos. Revision nerve (x2) Excision of sensory neuroma 6 Yes No Ulnar neuropathy Revision ulnar- No Excellent nerve transpos. 7 Yes (3) Yes Ulnar neuropathy Revision ulnar- Yes Poor nerve transpos. (x2) 8 No No Transient ulnarnerve paresth. (1 mo.) 9 No Yes Ulnar neuropathy Revision ulnar- No Excellent nerve transpos., repair of flexor muscle 10 No Yes Ulnar neuropathy (late onset) 1 1 No No Ulnar neuropathy, hematoma 1 3 No No Ulnar neuropathy, loss of range of motion 16 No Yes Transient ulnarnerve paresth. (3 mos.) ulnar- transpos. Revision nerve ulnar- transpos. Revision nerve ulnar- transpos. Revision nerve 17 No Yes Ulnar neuropathy Ulnar nerve No Good transpos. ulnar- transpos. Revision nerve 12 No No Transient ulnarnerve paresth. (3 mos.) 14 No Yes Transient sensorynerve paresth. (6 mos.) Repair 15 No No Ulnar neuropathy (late onset) No Yes No Yes No No Yes No Yes No Yes No Excellent Fair Excellent Good Excellent Excellent Fair Good Excellent Excellent Fair Excellent the fourteen patients in the repair group, thirteen were pitchers and one was an infielder. Six of the pitchers and the infielder had an excellent result. Mode of Onset of Symptoms Thirty-four (61 per cent) of the fifty-six patients in the reconstruction group could recall a single throw after which they had been unable to return to competition, and twenty-two (39 per cent) could not remember such an incident, although they could recall when the symptoms had begun. The patients who could relate the onset to a single throw had reconstruction of the ligament at a mean of 8.5 months (range,one to twenty months) after the injury. The result at the latest follow-up was excellent in twenty-five (73 per cent), good in three (9 per cent), fair in five (15 per cent), and poor in one (3 per cent). The patients who did not recall a single throw that THE JOURNAL OF BONE AND JOINT SURGERY

14 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES 79 had produced the injury had reconstruction of the ligament at a mean of eighteen months (range, one to thirtysix months) after onset. At follow-up, the result was excellent in thirteen (59 per cent), good in four (18 per cent), fair in three (14 per cent), and poor in two (9 per cent) (Fig. 13). For the reconstruction group, when the results in patients who recalled a single incident at onset were compared with those in patients who did not recall such an incident, there was no significant difference in the proportion of excellent results (chi-square test with Yates correction, p = 0.40). Source of Graft Material We were concerned that use of the ipsilateral palmans longus tendon for the graft might impair an athlete s ability to return to participation in sports. However, excellent results were obtained in ten of the fifteen patients in whom the ipsilateral palmaris longus was used, in twenty-one (70 per cent) of the thirty in whom the contralateral palmaris longus was used, and in seven of the eleven in whom tissues otherthan the palmaris longus were used (Fig. 14). Similarly, we were concerned that use of the plantaris or Achilles tendon might result in problems related to these tendons, but such problems did not occur. Duration of Rehabilitation Although the rehabilitation program was supervised by trainers or physical therapists, many patients progressed more rapidly than specified in the protocol. In the repair group, the baseball players resumed tossing a ball for a distance of five meters (fifteen feet) at a mean of three months (range, two to six months) after the operation and resumed competition at a mean of nine months (range, six to fourteen months). In the reconstruction group, the baseball players and javelin throwers resumed tossing the ball for five meters (fifteen feet) at a mean of 4.5 months (range, two to twelve months) and competed at a mean of twelve and one-half months (range, eight to twenty-one months). Of the fifty-two baseball players in this group, ten returned to competition in less than ten months and twenty-one, in less than twelve months. Excellent results were obtamed in seventeen (81 per cent) of the twenty-one baseball players who returned to competition in less than twelve months. Of the remaining thirty-one players who did not return to competition before twelve months, twenty-two returned by eighteen months and six, by twenty-four months; three never returned. Complications Except for one postoperative hematoma, problems related to either cutaneous nerves or the ulnar nerve at the elbow accounted for all of the complications in this series (Table I). One patient had transient paresthesia of the cutaneous nerve, which resolved after six months. Another had a cutaneous neuroma at the site of the incision; the symptoms were relieved by excision of the neuroma. The former patient had an excellent result; the latter was able to compete only at a lower level and continued to have mild pain in the elbow while throwing. Three of the fourteen patients in the repair group and twelve (21 per cent) in the reconstruction group had ulnar-nerve symptoms postoperatively. Of the fifteen patients, six (one in the repair group and five in the reconstruction group) had transient paresthesia of the ulnar nerve; this subsided after a mean of four months (range, one to eleven months). Five of the six patients had an excellent result. The remaining patient was a majorleague baseball player who had a good result and played in a minor league for two years. He retired but later returned to compete in the Senior Baseball League (not a major league) for two years. None of the six patients had any residual ulnar-nerve symptoms at a mean of seven years afterthe operation (range,five to nine years). Of the remaining nine patients who had postoperative ulnar-nerve symptoms, eight (one in the repair group and seven in the reconstruction group) had a revision procedure on the ulnar nerve, although the nerve had been transposed during the previous repair or reconstruction. In three of the eight, the symptoms had started more than five months after the operation. Four of the eight patients had an excellent result, three had a fair result, and one had a poor result. One of the four who had an excellent result still had mild paresthesias and atrophy of intrinsic muscles of the hand eight years after the operation. However, this patient, who was a majorleague baseball player, continued to play for five years after the reconstruction and pitched in a World Series (championship games between the leading teams of the two major leagues). Three of the eight patients had had another operative procedure before the repair or reconstruction, and five of the eight had residual paresthesias of the ulnar nerve at a mean follow-up ofsix years (range, three to eight years). The last patient who had postoperative ulnar-nerve symptoms was a minor-league baseball player who had had a direct repair of the ligament without transposition of the ulnar nerve. He had a good result initially, but an ulnar neuropathy developed ten months after he resumed playing. He was then treated with an anterior transposition ofthe ulnar nerve,twenty-two months after the initial procedure, but was released at that point from his minor league. He had no residual ulnar-nerve symptoms two years after this operation and was playing in a city baseball league. Discussion Waris37 apparently was the first to recognize and describe ruptures of the ulnar collateral ligament, in a review in 1946 of seventeen world-renowned javelin throwers. Since that time, many authors have noted the importance of injury to a ligament of the elbow in ath- VOL. 74.A, NO. I, JANUARY 1992

15 80 J. E. CONWAY, F. W. JOBE. R. E. GLOUSMAN, AND MARILYN PINK but we are aware of few who have analyzed the outcome of operative management2 #{176} 2. Some authors 3 have reported on injuries in non-athletes, and others 6 have described tears of the ulnar collateral ligament associated with dislocation of the elbow, but the mechanism of those injuries is different from that usually noted in throwing athletes. The injuries of the ulnar collateral ligament in the present study were associated with chronic overuse. The medial ligaments of the elbow (Fig. 1 ), which have been termed the ulnar collateral-ligament complex, include three parts: an anterior oblique bundle, a postenor fan-shaped bundle, and a relatively non-functional transverse segment The anterior oblique bundle is further divided into functionally separate anterior and posterior bands5. Under valgus load, the anterior band is taut while the elbow is flexed from 0 to 85 degrees, and the posterior band becomes taut at 55 degrees of flexion and remains taut throughout the remainder of flexion. In this way, one or both of the two bands of the anterior bundle is taut throughout the full arc of flexion, even though the humeral attachment of the bundle is located posterior to the axis of flexion of the elbow3. The posterior fan-shaped bundle of the ulnar collateral ligament is taut only when the elbow is flexed beyond 90 degrees#{176}3. Therefore, if operative treatment is to restore proper tension within the ulnar collateral-ligament complex throughout the full arc of flexion without limiting motion of the elbow, there must be a clear understanding of the cam-like relationship of thejoint surfaces of the elbow and the ulnar collateral ligament 225. The geometry of the bones of the elbow provides stability at less than 20 and more than 120 degrees of flexion34. Between these extremes, the contours of the joint surfaces do not provide stability, and the anterior oblique bundle of the ulnar collateral ligament is the primary medial stabilizer of the elbow joint 23 Dissections of cadavera have demonstrated that when this ligament is divided, the greatest valgus instability and the greatest internal-rotation instability are both at 70 degrees of flexion33. During the acceleration phase of a pitch, the elbow flexes progressively from 90 to 120 degrees offlexion and then rapidly extends, over a period of thirty to forty milliseconds, to 25 degrees of flexion when the ball is released. During this brief time, the elbow is subjected to great valgus stresses, and the peak angular velocity of the joint can rise to more than 4500 degrees per second27. These violent forces can exceed the tensile strength of the ulnar collateral ligament and produce microscopic tears within the ligament 2. It seems logical that continued throwing in the presence of injury to the ligament (and probably of altered throwing mechanics) can ultimately lead to attenuation or even rupture of the ligament. When this occurs, a throwing athlete can no longer compete at the previous level. King et al.7 reported that valgus stress on the elbow is first transmitted to the muscles and then to the medial ligaments of the elbow. Therefore, theoretically, the flexor-pronator muscles could resist valgus loading. However, data from fine-wire electromyographic studies at our institution, in which normal throwing athletes were cornpared with those who had injured the ulnar collateral ligament, showed that the activity of the flexor-pronator muscles of the forearm is substantially decreased in the presence of injury4. It is therefore probable that the flexor-pronator muscles contribute little as secondary stabilizers of the elbow after the ulnar collateral ligament is injured. Ruptures of the flexor muscles of the forearm in throwing athletes have been described previously 2 7, but we are not aware of reports in which these were associated with injury to the ulnar collateral ligament. In our series, nine patients (13 per cent) had an associated partial rupture of the tendon of origin of the flexor-pronator muscle group. Barnes and Tullos noted that, in their series of forty-one athletes who had had an injury of the medial aspect of the elbow, two had a repair of an isolated rupture of the conjoined tendon. These two patients were not able to return to sports, possibly because of an unrecognized injury in the ulnar collateral ligament. However, in our series, seven of the nine patients who had had this associated injury did return to the previous level of sport. Preoperatively, more than 40 per cent of the patients had symptoms of impairment of the ulnar nerve. In athletes who throw overhead and have an incompetent ulnar collateral ligament, injury or neuritis of the ulnar nerve may be secondary to three factors: traction, friction, or compression on the nerve4. Traction injuries result from valgus-stress loading in the presence of medial instability of the joint and as a sequela of developmental cubitus valgus, a common deformity of the elbow. Friction injuries are caused by subluxation of the ulnar nerve from its groove during repetitive throwing motions and by abrasion of the nerve at the joint line by osteophytes associated with degenerative or traumatic arthritis. In the presence of medial instability, the medial joint space opens as valgus stress is applied, and the nerve may be abraded by any projecting osteophytes. Finally, compression injuries result from impingement of the nerve, entrapment ofthe nerve by adhesions,calcification in the soft tissues, or hypertrophy of the flexor muscles of the forearm. When a direct repair of the ligament was performed in this series, the nerve was transferred anteriorly only if there had been prolonged ulnar-nerve symptoms preoperatively or if perineural adhesions were found in the ulnar groove. Because tunnels were made through the medial epicondyle into the ulnar groove to provide an adequate anchor for the graft, anterior transposition of the ulnar nerve was performed in all patients who had reconstruction of the ligament. When this was done, we were careful to avoid producing secondary sites of im- THE JOURNAL OF BONE AND JOINT SURGERY

16 MEDIAL INSTABILtTY OF THE ELBOW IN THROWING ATHLETES 81 pingement, and a complete release was performed from the level of the arcade of Struthers proximally to the interval between the two heads of the flexor carpi ulnaris distally. Submuscular transposition, as described by Learmonth2#{176}, was done to provide adequate protection for the nerve. One possible disadvantage of submuscular transposition is that the nerve is placed near the graft tissue that is used to reconstruct the ligament, and an entrapment neuropathy may develop as a result of formation of scar tissue. Other authors also have described complications related to the ulnar nerve after repair of the ulnar collateral ligament 39. In fifteen (21 per cent) of the seventy procedures that were done in this study, ulnar-nerve symptoms developed postoperatively despite meticulous handling and transposition of the nerve when the ligament was repaired or reconstructed. Fortunately, transient paresthesias of the ulnar nerve did not impair the athletes performance. One patient who had a direct repair of the ligament had had ulnar-nerve symptoms preoperatively but did not have a transposition of the ulnar nerve at the time of the repair. Teii months after he returned to competition, an entrapment neuropathy developed, and a transposition of the ulnar nerve was performed twenty-two months after the initial operation. The patient failed to return to the same level of athletic performance, but he had no ulnar-nerve symptoms on follow-up evaluation six years after the initial procedure (four years after the second procedure). Eight patients (14 per cent) had a secondary operative revision of the anteriorly transposed ulnar nerve; four of them were able to return to the preinjury level of participation in sports. The four who could not return to the preinjury level represent 6 per cent of our patients; two of the four had had previous operations on the medial part of the elbow, including one transposition of the ulnar nerve, before the reconstructive procedure. Therefore, two patients (3 per cent) were probably prevented from returning to their sport by ulnar-nerve symptoms that resulted from the operation. Almost 50 per cent of the forty-one patients in this series who were examined postoperatively did not have full extension of the elbow (0 degrees); 27 per cent lacked more than 5 degrees of extension, and 15 per cent lacked more than 10 degrees of extension. Kuroda and Sakamaki also found that 36 per cent of their thirteen patients had more than a 5-degree loss of full extension after repair of the ulnar collateral ligament. The flexion deformities of the elbow in this series apparently did not adversely affect strength or function, and other authors have also noted that pitchers can tolerate a flexion deformity without adverse effects on performance This lack of any adverse effect is not surprising since, from late cocking to follow-through, pitching involves motion of the elbow from only 120 to 20 degrees of flexion27. Although loss ofextension is undesirable,we thought that it was important to allow time for adequate incorporation ofthe graft before the repair or reconstruction was subjected to large stresses, despite the risk of loss of motion. However, it is possible that full extension in the early postoperative period may not impair healing of the graft. Because the configurations of the bones of the elbow contribute to its stability during the first 20 degrees of flexion of the elbow, clinical examination for valgus instability must be performed, and valgus-stress radiographs must be made, with the elbow flexed at least 30 degrees12#{176}. Although preoperative valgus-stress radiographs may confirm the diagnosis of an incompetent ulnar collateral ligament, the most sensitive indicators of ligamentous injury are the history and clinical examination. We believe that radiographs may be misleading; if stress radiographs are made to confirm the diagnosis, valgus-stress radiographs of the contralateral elbow should be made for comparison. Although several authors recommended that stress radiographs - either combined with arthrography or made under regional or general anesthesia - be made to confirm the diagnosis after an acute injury #{176}40,we have not found this to be necessary. The clinical results did not correspond to the findings on valgus-stress radiographs in all patients. Six patients (five in the reconstruction group and one in the repair group) had an excellent result with three millimeters of opening of the cartilage space. A poor result was seen in two patients, both in the reconstruction group, who had less than 1.5 millimeters of opening. The amount of preoperative degenerative articular changes, the integrity of the repaired or reconstructed ligament, the patient s normal laxity of the joint, and the amount of opening seen on valgus-stress radiographs postoperatively all may be related to the result. The indication for operation in this series was an athlete who had an incompetent ulnar collateral ligament, had failed to improve after non-operative treatment, and wanted to return to competitive sports. Five of the eight patients in the reconstruction group who returned to only a recreational level of sports thought that they could have returned to the preinjury level of cornpetition but chose not to do so because they wished to pursue other goals. The most common examples of this were college students who did not want a career in baseball and therefore did not wish to risk reinjuring the arm. It is not known whether an operation is appropriate for injured athletes who do not intend to continue playing at a highly competitive level. Operative exploration after dislocation of the elbow has shown that the ulnar collateral ligament is always ruptured 4 34, yet good results are usual after non-operative treatment 4. Indeed, valgus instability of the elbow may cause little inconvenience in daily life. However, we are aware of no published studies that show whether patients who have had a dislocation of the elbow can later participate VOL. 74-A, NO. 1. JANUARY 1992

17 82 J. E. CONWAY, F. W. JOBE, R. E. GLOUSMAN. AND MARILYN PINK in activities that involve repetitive valgus stresses on the elbow. Alternatively, valgus instability may cause traction ulnar neuritis4. Therefore, if the patient who has such instability wants to participate in recreational sports frequently and has ulnar-nerve symptoms, stabilization may be advisable to protect the ulnar nerve from additional injury. Pain during the follow-through phase while throwing may be due to impingement of the posteromedial olecranon in the olecranon fossa. This has been termed valgus extension overload and may result in the development of osteophytes on the posteromedial margin of the olecranon and loose fragments of bone within the olecranon fossa. Although in many patients impingement may be eliminated by restoration of the ulnar collateral ligament, we believe that it is important to remove any posterior osteophytes and loose bodies at the operation. Direct repair of the anterior band of the ulnar collateral ligament was advocated in 19782, and a technique for reconstruction was described in Since 1987, we have performed a reconstruction in all patients who have an incompetent ulnar collateral ligament, but we believe that a few carefully selected patients may still be candidates for a direct repair. Thus, if a patient who has had an acute injury with no associated ulnar-nerve symptoms has an operation soon after the injury and the ulnar collateral ligament appears normal except for a complete separation from bone at its origin or insertion, a direct repair can be considered. Since only 13 per cent of our patients had an avulsion injury of the ligament, one would rarely expect to find a ligament suitable for repair. Furthermore, because the frequency of postoperative ulnar-nerve symptoms has been similar after the two procedures, the recommended times for rehabilitation are the same, the removal of the palmaris longus tendon for the graft causes minimum morbidity, and the over-all results after reconstruction appear to be better, we are more confident of a satisfactory result after reconstruction of the ligament. Recently, Regan et al.5 reported that the palmaris longus tendon fails at higher loads and has almost four times the ultimate strength of the anterior band of the ulnar collateral ligament. In our series, we found that the results obtained with the different grafts were the same, but we prefer the ipsilateral palmaris longus tendon if it is available. Although many athletes who had a reconstruction of the ligament in this series were able to return to competition before twelve months, most of the pitchers reported that it was eighteen to twenty-four months before they could pitch six to eight innings in a game and participate in a regular pitching rotation. In the repair group, the mean time the pitchers needed to return to competition was almost four months less than that in the reconstruction group. The short duration of rehabilitation may have adversely affected the results in the repair group. However, repair was performed only when there was adequate normal-appearing ligament, and a full year of rehabilitation before competition might not have been necessary. In baseball pitching, the curveball frequently is blamed for problems with the elbow. A curveball generates less torque on the elbow than a fastball; however, there is less time available for deceleration of the elbow in throwing a curveball, and therefore there is greater angular velocity in the elbow after release of the ball. The peak rate of deceleration and shear forces on the joint are higher when a curveball is thrown2. McLeod2 suggested that there is a theoretical basis for considering that this pitch may have the most destructive effect on the elbow of any pitch. We found that, although 66 per cent of our pitchers used a slider and 45 per cent used a curveball as the primary back-up pitch, almost all of them (84 per cent) relied mostly on the fastball. In this series, we were unable to confirm that throwing curveballs has a destructive effect on a pitcher s elbow. After repair or reconstruction of the ulnar collateral ligament, we stress that athletes must rehabilitate the shoulder along with the elbow and maintain good overall physical condition to minimize the risk of injury during the early postoperative period. Furthermore, we emphasize that proper throwing mechanics, balance, and coordination must be restored before return to competition. We believe that this principle also applies to athletes returning at the beginning of the playing season. In summary, after reconstruction of the anterior band of the ulnar collateral ligament with an autologous tendon graft, most athletes who had been unable to participate in throwing sports because of medial instability of the elbow were able to return to the previous level of participation. When other operations had been performed on the elbow before reconstruction of the ulnar collateral ligament, the chance of return to competitive sports was significantly reduced. A postoperative flexion deformity of the elbow of more than 10 degrees may not prevent excellent throwing performance; four of the six patients who had a flexion deformity of 10 to 25 degrees after reconstruction of the ulnar collateral ligament had an excellent functional result. Because of the possibility of postoperative ulnar neuropathy, function of the ulnar nerve should be carefully determined before the operation. References 1. Andrews, J. R.: Bony injuries about the elbow in the throwing athlete. In Instructional Course LectureA The American Academy of Orthopaedic Surgeons. Vol. 34, pp St. Louis, C. V. Mosby, Barnes, D. A., and Tullos, H. S.: An analysis of 100 symptomatic baseball players. Am. J. Sports Med., 6: 62-67, DeHaven, K. E., and Evans, C. M.: Throwing injuries ofthe elbow of athletes. Orthop. Clin. North America, 4: , THE JOURNAL OF BONE AND JOINT SURGERY

18 MEDIAL INSTABILITY OF THE ELBOW IN THROWING ATHLETES Glousman, R. E.: Ulnar nerve problems in the athlete s elbow. Clin. Sports Med., 9: l99(). 5. Glousman, R. E.; Barron,J.;Jobe, F.W.; Perry,J4 and Pink, M.: An electromyographic evaluation of normal and injured elbows in throwing athletes. Unpublished data. (7. Gugenheim,J.J.,Jr.; Stanley, R. F.; Woods, 6. W.; and Tullos, H. S.: Little League survey: the Houston study. Am. J. Sports Med., 4: (), Cutierrez, L. S.: A contribution to the limiting factors ofelbow extension.actaanat., 56: Hang, Y.-S.; Lipped, F. C., III; Spolek, G. A.; Frankel, V. H.; and Hamngton, R. M.: Biomechanical study of the pitching elbow. Intern at. Ort/iop., 3: , Hotchkiss, R. N., and Weiland, A. J. Valgus stability of the elbow. J. Orthop. Re.s, 5: Indelicato, P. A.; Jobe, F. W.; Kerlan, R. K.; Carter, V. S.; Shields, C. L.; and Lombardo S. L: Correctable elbow lesions in professional baseball players: a review of 25 cases. Am. J. 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