Epidemiology, Anatomy, Mechanism of Injury, History, Physical Examination, and Imaging
- Christopher S. Ahmad, MD
- Justin L. Hodgins, MD
Abstract
Injury to the medial ulnar collateral ligament (MUCL) of the elbow is a debilitating condition primarily affecting overhead throwing athletes. Overuse injuries to the ligament are very common, because throwing places tremendous valgus torque across the elbow and MUCL. The injury is most common in baseball as it can be seen in 10% of all players and 16% of of pitchers have undergone MUCL reconstruction (Conte et al. 2015). MUCL injuries are problematic, because it provides the primary restraint to valgus stress in the elbow. When diagnosing MUCL injuries, it is critical to do a thorough history and physical exam in conjunction with MRI or MR arthrography. The MRI offers visualization of the concomitant injuries in the elbow, making it more reliable for a surgeon to make a correct preoperative decision.
Keywords: anatomy, elbow, epidemiology, Medial ulnar collateral ligament, overhead throwing athletes
Introduction
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Injury to the medial ulnar collateral ligament (MUCL) of the elbow is a debilitating condition primarily affecting throwing athletes.
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The MUCL complex provides the primary restraint to valgus stress in the elbow together with dynamic muscular support and the posterior bony articulations.
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Most MUCL injuries are the result of the cumulative valgus stress placed on the medial elbow during repetitive overhead throwing maneuvers, and clear associations have been made with overuse and risk of injury.
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Careful history and physical examination, including the presence of tenderness along the MUCL and a positive moving valgus stress test result, are sensitive and specific for MUCL injury
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Athletes with suspected MUCL injury should undergo either plain magnetic resonance imaging (MRI) or MR arthrographic studies to characterize the ligament
Epidemiology
Overuse injuries are common in overhead athletes, particularly in elite baseball, where throwing places tremendous valgus torque across the elbow and MUCL. As such, competitive baseball exhibits the highest incidence of MUCL injury and surgical reconstruction ( ). However, MUCL injury has also been reported in other overhead throwing sports, including javelin, tennis, and American football ( ). Before popularization by Dr. Frank Jobe, the first description of MUCL rupture was a review of 17 elite javelin throwers in 1946 ( ). Although rare, MUCL injury has been reported in professional football ( ). A review of the National Football League Injury Surveillance System (NFLISS) from 1994 to 2008 identified 10 MUCL injuries in quarterbacks, primarily as a result of acute trauma. Other than these few accounts, MUCL tears and subsequent reconstruction are injuries exclusive to competitive baseball, and in particular, elite pitchers.
Clear associations have been demonstrated between the number of innings pitched in a calendar year and the chance of sustaining a serious elbow injury in youth baseball ( ). The competitive culture of youth baseball may encourage talented players to participate on multiple teams and showcases, therefore throwing more frequently and with greater intensity at younger ages. A prospective cohort study of 481 youth pitchers over 10 years of play identified that players who pitched more than 100 innings per calendar year had a 3.5 times greater chance of sustaining a serious injury ( ). A similar investigation of adolescent pitchers described overuse as the main cause of player injury, noting a 500% increased risk for surgery for players pitching more than 8 months per year and a 400% increased risk for those throwing more than 80 pitches per game ( ). These trends have led to the implementation of injury prevention programs with emphasis on public education to the risks of overuse throwing injuries and the importance of adhering to pitch-count guidelines.
Despite these public health campaigns, reports suggest that the number of MUCL injuries and reconstructions continue to rise, with an estimated 10-fold increase in the first decade of the 21st century ( ). Evidence also suggests an increase in the frequency of MUCL injury and reconstruction in younger athletes. A large review of high school baseball pitchers identified a 50% increase in MUCL reconstruction in players ages 15 to 19 reported by a single surgeon ( ). Similarly, a database of a large privately insured U.S. population demonstrated significant increases in MUCL reconstructions in patients ages 15 to 19 years from 2007 to 2011 ( ). The estimated annual incidence of MUCL reconstruction was 3.96 per 100,000 patients for the overall population, and there was a significant increase in the number of procedures performed over time. A subsequent investigation using a New York State database demonstrated a threefold increase in the incidence of MUCL reconstruction from 2002 to 2011, in particular in patients ages 17 to 19 years ( ).
Debate still exists regarding the relationship between pitch type and risk of medial elbow injury in youth baseball. Previously, the altered kinematics required to generate the throwing motion of breaking balls (curveball, slider) was linked to an increased risk in shoulder and elbow pain in adolescent pitchers ( ). A follow-up study evaluating the risk factors for shoulder and elbow injuries requiring surgery in adolescent pitchers failed to identify a correlation between injury and onset of throwing breaking-type pitches but indicated a 250% increased risk for those who could throw a fast ball faster than 85 mph ( ). Furthermore, biomechanical testing using three-dimensional motion analysis has demonstrated that the curveball produces less elbow torque than does the fastball in youth pitchers ( ).
A major concern now exists regarding the increasing number of MUCL injuries and surgeries being performed within Major League Baseball (MLB), with the phenomenon being described as an “epidemic” of MUCL reconstruction ( ). Studies using data from the MLB Disabled List (DL) have shown that medial elbow injuries represent 16% to 22% of all player injuries ( ). The most recent investigation of both minor and major league baseball players estimated that as many as 10% of all players and 16% of pitchers have undergone MUCL reconstruction ( ). The prevalence of MUCL reconstruction in nonpitching position players was substantially lower (3%). The rate of MUCL reconstruction was also higher among MLB pitchers compared with minor league players and was highest in older players. A separate study identified higher pitch velocity as the most predictive factor for MUCL reconstruction in MLB pitchers and increased player weight and younger age as secondary predictors ( ).
Anatomy
The MUCL complex provides the primary restraint to valgus stress in the elbow and consists of an oblique, posterior, and anterior bundle ( ) ( Fig. 26A.1 ). The oblique or transverse ligament has its origin and insertion on the ulna and together with the posterior capsular thickening provides minimal stability to the elbow ( ). The anterior bundle of the MUCL is the strongest component of the complex and the main restraint to valgus stress ( ). It originates on the anterior-inferior surface of the medial humeral epicondyle and inserts on the sublime tubercle of the ulna ( ). The anterior bundle is functionally composed of anterior and posterior bands that provide reciprocal function in resisting valgus stress between 20 and 120 degrees of elbow flexion ( ). The anterior band is active at lesser degrees up to 90 degrees, and the posterior band provides assistive restraint from 60 degrees to higher degrees of flexion ( ).
In addition to the MUCL complex, dynamic muscular support and the bony articulations of the posterior elbow compartment contribute to medial stability. The fibers of the flexor carpi ulnaris (FCU) are intimately attached to the origin of the medial epicondyle and optimally positioned directly in line with the MUCL for contractile support ( ). Cadaver biomechanical testing has demonstrated the FCU as the primary dynamic contributor to valgus stability in the elbow and the flexor digitorum superficialis as a secondary stabilizer ( ). Clinical electromyographic analysis has also demonstrated reduced forearm flexor muscle activity in pitchers with MUCL injuries, further suggesting the role of protective dynamic muscle activity ( ). The importance of the flexor-pronator mass is also appreciated by several authors, who advocate limiting dissection using muscle splitting techniques during MUCL reconstruction and recognize the importance of dynamic muscular rehabilitation during the postoperative period ( ).
The bony articulations of the posterior compartment share an intricate relationship with the soft tissues of the medial elbow. As the MUCL complex is stressed during valgus loading, the lateral radiocapitellar articulation undergoes compensatory compression. Biomechanical analysis has demonstrated that sequential partial resection of the posteromedial aspect of the olecranon results in a stepwise increase in elbow valgus angulation ( ). Therefore both the olecranon and the MUCL contribute to valgus stability. This has also been observed clinically, where 25% of professional baseball players who underwent olecranon debridement eventually required MUCL reconstruction in a large series ( ). Testing in the cadaver model has also shown that strain in the MUCL is increased with increasing posteromedial resection of the olecranon beyond 3 mm, further suggesting that aggressive olecranon debridement may place the MUCL at risk for future injury ( ).
Mechanism of Injury
The majority of MUCL injuries are the result of the cumulative valgus stress placed on the medial elbow during repetitive overhead throwing maneuvers ( ). Biomechanical studies have shown the valgus torque generated in the late cocking and acceleration phases of throwing can exceed 64 N-m and up to 60 N-m with a tennis serve, but the ultimate tensile strength of cadaveric MUCL specimens is only 33 N-m ( ). The repetitive near-tensile failure loads result in microtrauma to the anterior band of the MUCL, leading to attenuation and ultimately failure. When the forearm flexors are fatigued or injured, the elbow loses the dynamic muscular supports, placing additional stress on the MUCL. Therefore flexor-pronator conditioning is an essential component of MUCL injury prevention programs.
Although rare, MUCL injury can occur as a result of direct trauma in contact athletes.
A total of 10 MUCL injuries were documented in professional quarterbacks over a 14-year period in the National Football League (NFL), where 70% of injuries were the result of traumatic contact and only 20% associated with a throwing motion ( ). The nature of these acute traumatic MUCL tears was attributed to the high contact loads experienced at the elbow by football players as opposed to the chronic repetitive injuries seen in baseball pitchers. Fundamental differences also exist in the passing motion of football quarterbacks compared with baseball pitching because the increased weight of the football prevents the extreme angular velocities and torque across the elbow seen in pitching ( ). Kinematic testing has also demonstrated reduced rotational velocities over a narrower shoulder range of motion during the football pass, thereby reducing valgus stress on the medial elbow ( ).
History and Physical Examination
A thorough history and physical examination are critical in evaluating MUCL injuries, as treatment recommendations rely heavily on a variety of patient- and injury-specific factors. Player age, type of sport, position, competitive level, future aspirations, willingness of the player to change sport or position, and perceptions of surgery should be considered ( ). Specifically for throwing athletes, any recent changes in throwing accuracy, velocity, and stamina before injury should be documented. The time of onset of symptoms in relation to ball release is also important because up to 85% of pitchers experience pain during the acceleration phase of throwing compared with fewer than 25% during the deceleration phase of throwing with MUCL injury ( ) ( Fig. 26A.2 ). Players may report a sudden event with sharp pain in the medial elbow accompanied with a “pop”; others may have a gradual progression of pain associated with changes in pitching speed and control. Duration of symptoms, prior episodes, and the exact location of the pain should be documented.
Injury risk factors should be assessed, such as a history of overuse (particularly in skeletally immature athletes), prior elbow surgery (arthroscopic posteromedial decompression), or change in pitching mechanics. Symptoms of valgus extension overload (VEO), including posteromedial elbow pain during either the acceleration phase or more commonly the deceleration phase of throwing, should be assessed because MUCL insufficiency may be overshadowed in these athletes. Limited extension and mechanical catching may also be present with VEO as a result of impinging osteophytes, chondromalacia, or loose bodies. Ulnar neuritis associated with MUCL insufficiency can manifest as paresthesia radiating from the elbow to the ring and small fingers. Cold intolerance, numbness or tingling in the hand, and difficulties with grip strength or dropping objects may also be present ( ).
Physical examination should include a detailed evaluation of the entire upper extremity and assess problems within the core and kinetic chain. Careful attention should be given to the ipsilateral shoulder as it is not uncommon for elbow and shoulder pathology to coincide in elite throwing athletes. The presence of a glenohumeral internal rotation deficit (GIRD) and reduced total rotational motion (TRM) have been identified as independent risk factors for MUCL injury ( ). The scapula should be assessed with respect to muscle tone and scapulothoracic rhythm because scapular dysfunction is often present in throwing athletes ( ). The presence of a flexion contracture with a lack of full elbow extension is also common in mature throwers and may be asymptomatic and should be compared with the contralateral limb.
The medial aspect of the elbow should be inspected for swelling and ecchymosis and palpated for tenderness along the course of the MUCL from its origin to insertion. Chronic tears may not have associated tenderness, and in acute tears, tenderness often abates with rest. Local MUCL tenderness should be distinguished from flexor-pronator injury. The absence of pain with resisted wrist flexion and pronation and the presence of pain posterior to the flexor-pronator origin can help to differentiate ( ). Ulnar nerve examination should include motor and sensory testing and provocative maneuvers such as the Tinel test for direct nerve irritation and dynamic instability with elbow motion. The presence of a palmaris longus tendon should be determined if MUCL reconstruction is anticipated.
Valgus instability is assessed with the elbow flexed between 20 and 30 degrees to unlock the olecranon from its fossa ( ). The valgus stress test may be performed with the patient upright or lying supine as the examiner applies a valgus force, attempting to elicit painful opening of the medial ulnohumeral joint. Isolated anterior band injury can produce opening at 30 to 40 degrees of elbow flexion, but a global MUCL injury may demonstrate opening at 80 to 90 degrees of flexion ( ). The milking maneuver is performed by the examiner pulling on the patient’s thumb to create valgus stress with the patient’s forearm supinated and elbow flexed beyond 90 degrees. A positive test result elicits pain, instability, and apprehension and indicates injury to the posterior band of the MUCL ( ). The moving valgus stress test is the most sensitive and specific for MUCL pathology and is performed by applying a valgus torque while the elbow is repeatedly flexed and extended ( ) ( Fig. 26A.3 ). The test result is considered positive if pain is reproduced at the MUCL and is usually maximal between 70 and 120 degrees of elbow flexion in an attempt to recreate the early acceleration and late cocking phases of throwing.
Imaging
Standard anteroposterior, lateral, and oblique radiographs of the elbow are first obtained when evaluating for MUCL injury. In the presence of chronic injury, ossification along the path of the MUCL may be noted ( Fig. 26A.4 ). The presence of olecranon osteophytes, posteromedial joint space narrowing, and loose bodies suggest underlying VEO, arthritis, or both. Radiographs can also identify other abnormalities, including bone deficiencies at the sublime tubercle or medial epicondyle from prior fracture, altered epicondylar morphology, or enthesopathy at the sublime tubercle, each potentially influencing treatment and reconstruction technique ( ). Computed tomography with three-dimensional reconstruction can further delineate osseous pathology around the elbow and help plan for future osteophyte resection.
All patients with suggestive history and positive examination findings undergo MRI to characterize the MUCL. Conventional MRI studies are capable of identifying ligament thickening from chronic injury and large full-thickness tears. MR arthrography, enhanced with intraarticular gadolinium contrast, improves the diagnostic ability for partial-thickness tears ( ). Therefore when standard MRI is inconclusive, the preferred imaging modality is MR arthrography using a high-field closed magnet with narrow slice images ( Fig. 26A.5 ). The “T-sign” is seen where a pathologic volume of contrast dye leaks down along the sublime tubercle but is contained under the superficial fibers of a partially torn MUCL ( ). However, anatomical studies have characterized the insertion of the MUCL at 2.8 mm, on average, from the articular surface of the ulna, and thus some T-signs may be normal ( ). MRI can also identify concomitant edema and injury to the flexor-pronator origin as well as posteromedial ulnohumeral chondromalacia ( ).
Surgical Treatment and Outcomes: Posteromedial Impingement—Debridement and Ulnar Collateral Ligament Reconstruction
- James R. Andrews, MD
- Karim A. Meijer, MD
- Jarrod R. Smith, MD
- Karim A. Meijer, MD
Abstract
This chapter describes the surgical techniques and outcomes for posteromedial impingement of the elbow and elbow ulnar collateral ligament reconstruction.
Keywords: elbow arthroscopy, posteromedial impingement, UCL, ulnar collateral ligament
Introduction
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Elbow arthroscopy and a limited elbow arthrotomy can treat the pathology of posteromedial impingement seen in valgus extension overload.
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The preferred technique is a supine-suspended elbow arthroscopy when treating isolated posteromedial impingement.
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Portal placement is crucial to safe and efficient elbow arthroscopy.
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When performed with a concomitant ulnar collateral ligament (UCL) reconstruction, a vertical arthrotomy is made posterior to the posterior band of the ligament to address posteromedial impingement.
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Both arthroscopic and open decompression of posteromedial impingement have reported favorable results in the literature.
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UCL reconstruction is a successful procedure to return overhead athletes to play.
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The preferred technique is a modified Jobe technique.
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The preferred graft is a palmaris longus autograft.
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Transposition of the ulnar nerve is a crucial portion of the procedure.
Posteromedial Impingement Surgical Technique
Both elbow arthroscopy and a limited elbow arthrotomy can treat the pathology of posteromedial impingement seen in valgus extension overload. The preferred technique of the senior author depends on whether a concomitant UCL reconstruction is being performed. When in isolation, the preferred technique is a supine-suspended elbow arthroscopy. However, with a UCL reconstruction and when the ulnar nerve is transferred, an open decompression is performed through a limited posteromedial capsular arthrotomy.
Elbow Arthroscopy
The patient is placed supine on the operating room table. After induction of general anesthesia, the table is turned 90 degrees to create sufficient operative space. The operative limb is placed in traction with a balanced suspension of 5 to 8 lb of weight. The arm should be suspended at rest at approximately 90 degrees of flexion at the elbow ( Fig. 26B.1 ). The arm is prepped and draped in standard fashion based on the surgeon’s preference with a tourniquet. Video monitors are positioned over the contralateral shoulder of the patient and torso of the patient. Two video monitors are used to switch between a 4.0-mm, 30-degree arthroscope and a 2.7-mm, 30-degree arthroscope depending on which compartment within the elbow is being visualized. A pump is optional and when used is set to 35 mm Hg to maintain joint distention. Nonvented cannulas are used to minimize fluid extravasation. The 4.0-mm, 30-degree arthroscope is used in the anterior and posterior compartment, and the 2.7-mm, 30-degree arthroscope is used in the lateral compartment through the direct lateral or “soft spot” portal. Important landmarks such as the lateral epicondyle, medial epicondyle, radial head, olecranon, and ulnar nerve are palpated and marked with a surgical pen.
Portal placement is crucial to safe and efficient elbow arthroscopy. Before starting, 30 to 40 mL of normal saline is used to distend the joint through the “soft spot” portal via an 18-gauge spinal needle. This “soft spot” portal lies in the triangle formed by the radial head, lateral epicondyle, and olecranon. A second spinal needle is placed in the antero-lateral portal, which is located approximately 1 cm anterior to the lateral epicondyle. Back flow of fluid confirms intraarticular placement of the spinal needle. A #11 blade is used to make a small skin incision in line with the spinal needle. Blunt hemostats are used to dilate the incision while a blunt trocar is used to penetrate into the anterior compartment of the elbow. The 4.0-mm, 30-degree arthroscope is used to view the anterior compartment. The coronoid and trochlea are visualized within the anterior compartment. Furthermore, flexion and a valgus load can be applied with the help of an assistant to view the UCL and assess for stability. This is typically done in approximately 70 degrees of flexion. It has been reported that an opening of 1 to 2 mm between the medial trochlea and coronoid is indicative of injury to the anterior bundle of the UCL ( ). If needed, an anteromedial portal may be established through direct visualization. An 18-gauge spinal needle is introduced approximately 1 cm distal and 2 cm anterior to the medial epicondyle. It is important to always palpate the medial intermuscular septum and to remain anterior to this landmark. We do not routinely use this portal when addressing posteromedial impingement; however, it can be useful for inspection of the anterolateral compartment of the elbow including the radiocapitellar joint.
Next, the “soft spot” portal is created with a #11 blade in the same trajectory previously used to distend the joint before beginning the arthroscopy. A 2.7-mm, 30-degree arthroscope is used to visualize the lateral compartment of the elbow. Through this portal, the posterior aspect of the radial head, proximal radioulnar joint, capitellum, and olecranon can be visualized. The 40-mm, 30-degree arthroscope remains in the anterior compartment to provide fluid to the joint. It is important to maintain the arthroscope within the anterior compartment to prevent any extraarticular fluid extravasation. The use of the “soft spot” portal provides a means to create a posterolateral portal under direct visualization. The posterolateral portal is 3 cm proximal to the tip of the olecranon and just lateral to the edge of the triceps tendon along the lateral epicondylar ridge. A spinal needle is used to confirm the intraarticular placement of the portal under direct visualization. The joint capsule is robust in this area, and blunt penetration with a trocar can be difficult. Therefore a #11 blade is used under direct visualization to make the portal. After the trocar is positioned, the 40-mm, 30-degree arthroscope is moved to the posterior compartment. At this point, the assistant extends the elbow to about 30 degrees of flexion to create the posteromedial portal. This portal is placed approximately 1 to 2 cm proximal the tip of the olecranon and just off the medial edge of the triceps ( Fig. 26B.2 ). Sometimes this portal is placed transtendinous through the triceps. However, we try to avoid a transtendinous placement in overhead throwing athletes to reduce any possible source of pain as the elbow is fully extended during the throwing motion. The key is to make sure this portal provides approximately a 90-degree angle in terms of the instrumentation with the posterolateral portal.
The posterolateral portal is used as the “viewing portal,” and the posteromedial portal becomes the “working portal” when addressing the pathology associated with posteromedial impingement. The soft tissue is cleared with a 4.5-mm arthroscopic shaver and decompression of the osteophytes is done with a hooded 5.5-mm arthroscopic bur ( Fig. 26B.3 ). The elbow is placed in near full extension to assist in debridement of the osteophyte while flexing of the elbow allows for evaluation of the humeral articular cartilage. Often, a “kissing lesion” on the trochlea can be seen and may need to be debrided. Radiographs or computed tomography (CT) scans (or both) are used preoperatively to evaluate the posteromedial osteophytes and should be present and viewed in the operating room before and during the operation. Overzealous resection of the osteophytes can preload the UCL. Care should be taken to resect only pathologic bone while leaving normal bone. Often, a fibrous union can be seen on radiographs or CT. A banana blade can be used to enter the fibrous union and dislodge the pathological osteophyte. Furthermore, axial traction with the elbow at 90 degrees of flexion can be used to assist in resection of the osteophyte. This technique creates a few millimeters of space between the olecranon and humerus, which helps define the underlying articular cartilage of the trochlea. After completion of the decompression, the arthroscope is placed in the posteromedial portal and the posterior compartment is evaluated for any loose bodies and any bony pieces that came loose from the decompression.
The skin portals are closed with #3-0 Ethilon (Ethicon, Somerville, NJ) suture, and a full-length compressive, sterile dressing is applied. The patient is placed in a simple sling and educated on range of motion (ROM) exercises of the shoulder, wrist, and hand. Often, a medium Hemovac drain is placed through the anterolateral portal for the first 24 hours. Gentle active and active-assisted exercises are begun immediately with passive ROM started on postoperative day 5. Aggressive early ROM exercises can cause drainage through the posterior portals and a sinus can potentially develop or even a postoperative wound infection. Motion exercises are progressed through week 3 until further strengthening and eccentric exercises are started. At 6 weeks, an interval-throwing program is started with return to full time activities by 12 to 16 weeks.
Open Decompression
The standard operative setup and approach to the elbow used for a UCL reconstruction as previously described is used for an open decompression and excision of posteromedial osteophytes. Before drilling the ulnar and humeral tunnels and after the ulnar nerve has been completely mobilized, a 1- to 2-cm vertical arthrotomy is made posterior to the posterior band of the UCL from the medial epicondyle to the tip of the olecranon. This allows for retraction and complete visualization of the posteromedial olecranon osteophytes from the medial side. A one-quarter inch osteotome is used to excise the osteophytes in addition to a 4.0-mm round bur (Stryker) for fine-tuning the posteromedial olecranon. The ulnar nerve is protected with army-navy retractors, and the elbow is placed in approximately 30 degrees of flexion with a valgus stress. Copious bulb irrigation is used to clear the joint of bone debris and improve visualization. The elbow is brought through an ROM to ensure adequate motion and elimination of bony impingement. The arthrotomy is closed with #1 absorbable braided suture before continuing with UCL reconstruction. The postoperative course is dictated by the UCL reconstruction protocol.
Posteromedial Impingement Outcomes
Both arthroscopic and open decompression of posteromedial impingement have reported favorable results in the literature ( ). The first reported description of posteromedial impingement was reported by Wilson et al (1983) on five pitchers who underwent an open decompression. All five were able to return to pitching for a minimum of one full season at maximum effectiveness with an average time to return of 11 weeks ( ). One of the five patients required a second operation for recurrent symptoms. Open management of posteromedial impingement still remains the senior author’s preference when performed in conjunction with a UCL reconstruction or ulnar nerve transposition. reported no difference in return-to-play outcomes for players who had a concomitant open posteromedial olecranon excision during the index UCL reconstruction (86%) versus those without excision (82%) ( P = 0.21).
As arthroscopic techniques have continued to advance, the management of posteromedial impingement is more commonly treated arthroscopically ( ). In a large series reported that 47 of 55 (85%) professional athletes returned to previous level of play after arthroscopic treatment of posteromedial impingement and 87% reported “good” to “excellent” results ( ). Furthermore, reported on 16 patients treated for posterior impingement of the elbow with an increase in Modified Andrews’ Elbow Scoring System (MAESS) scores from 69 (average score) preoperatively to 93 (excellent score) postoperatively. reported on a series of 9 pitchers (5 professional and 4 recreational) with posteromedial elbow impingement treated arthroscopically. On the basis of Andrews-Carson scale, the subjective and objective outcomes were considered excellent in 7 patients and good in 2. Last, found a postoperative satisfaction rate of 91% in patients treated arthroscopically for posteromedial impingement.
Although arthroscopic techniques have demonstrated good to excellent results, the reoperation rate after an isolated arthroscopic debridement of posteromedial osteophytes has been reported to be as high at 41% ( ). Furthermore, reported 10 of 53 (19%) patients who underwent posteromedial decompression returned for a secondary procedure on average at 25.4 months (range, 4.5–72.4) from the index procedure. Return-to-play for this cohort was 71% (38 of 53). In addition, reported that after removal of a posteromedial osteophyte, 25% of patients eventually required an UCL reconstruction. The authors suspected the reason for this was either loss of the posteromedial buttress or failure to initially appreciate the severity of the underlying associated UCL injury.
Ulnar Collateral Ligament Reconstruction Surgical Technique
The senior author’s preferred graft choice for UCL reconstruction is the ipsilateral palmaris tendon. If the tendon is absent or insufficient, the contralateral gracilis tendon is used. The senior author prefers to harvest the gracilis tendon using a minimally invasive popliteal incision. The following surgical technique describes UCL reconstruction with ipsilateral palmaris autograft using the modified Jobe technique.
Graft Harvest and Preparation
The patient is placed in the supine position on the operating room table, and the operative extremity is placed on a hand table. A nonsterile tourniquet is placed on the extremity, and it is prepped and draped in standard fashion. Coban (3M, Maplewood, MN) is wrapped around the hand, being sure not to cover the incision sites for palmaris harvest. An Ioban (3M) drape is placed on the remaining exposed skin of the operative extremity. The extremity is exsanguinated, and the tourniquet is inflated to 250 mm Hg.
Two 1-cm incisions are then made over the palmaris tendon on the volar aspect of the forearm. The distal incision should be made over a wrist crease to improve cosmesis. The proximal incision should be created 2 to 3 cm proximal to the first incision. Blunt dissection is used to expose the palmaris tendon through both incisions. Care must be taken to coagulate bleeding vessels within these incisions because a hematoma can form in this area and compress the median nerve. The palmaris tendon is isolated by placing a curved hemostat beneath the tendon through each incision ( Fig. 26B.4 ). The median nerve must be protected during retrieval of the palmaris tendon as it lies just deep to the palmaris tendon. The wrist is then flexed, and the tendon is transected using a scalpel through the distal incision. The tendon should be transected as distally as possible to ensure adequate graft length. The tendon is retrieved through proximal incision, and a 0 Ti-Cron (Covidien, New Haven, CT) suture is used to place a locking stitch that will be used for graft passage ( Fig. 26B.5 ).
Tension is pulled on the transected tendon so that it is easier to palpate in the proximal forearm. A third transverse incision is made over the musculotendinous junction of the palmaris, approximately 15 cm proximal to the proximal wrist incision. Blunt dissection is performed down to the forearm fascia, and any bleeding vessels are coagulated. The forearm fascia is split longitudinally, and a curved hemostat is placed beneath the palmaris musculotendinous junction. The palmaris tendon is retrieved through the third incision using the curved hemostat. Tension is pulled on the tendon to increase graft length ( Fig. 26B.6 ). Muscle fibers are removed from the proximal portion of the palmaris tendon. The tendon is transected, and a 0 Ti-Cron (Covidien) suture is used to place a locking passing stitch in this end of the tendon. The minimum graft length is 13 cm, but it should be made as long as possible. When the graft harvest is completed, the small longitudinal fascial split in the third incision is closed with 2.0 Vicryl (Ethicon). If this fascial split is not closed, a muscular herniation can occur. Skin incisions are closed with simple, interrupted 3.0 Prolene (Ethicon). The graft is then taken to the back table and placed in a basin.
Ulnar Collateral Ligament Reconstruction
An incision is made, centered over the medial epicondyle. The incision forms a 160-degree angle, with the proximal limb extending 3 cm from the central aspect of the medial epicondyle and the distal limb extending 6 cm distally ( Fig. 26B.7 ). Blunt dissection is carried out down to the forearm fascia. The medial antebrachial cutaneous nerve is identified, and a vessel loop is placed around it ( Fig. 26B.8 ). The nerve typically crosses the field in the distal one third of the incision, but its course can be quite variable. Care must be taken to free the nerve proximally and distally to ensure that it can be retracted either anteriorly or posteriorly during ulnar nerve exposure and tunnel drilling.
The ulnar nerve is identified within the wound proximally, beneath the fascia of the medial head of the triceps. It lies just posterior to the medial intermuscular septum, deep to the fascia. The skin and subcutaneous tissue are retracted, and the ulnar nerve is circumferentially freed proximally from Osborne’s ligament through the arcade of Struthers. A vessel loop is then placed around the ulnar nerve. Osborne’s ligament is divided, revealing the ulnar nerve in the cubital tunnel. The UCL lies deep to the ulnar nerve here. Distal to Osborne’s ligament, the fascia overlying the flexor carpi ulnaris (FCU) is divided to the distal extent of the incision. A periosteal elevator is used to bluntly divide the two heads of the FCU, revealing the ulnar nerve in the proximal aspect of the forearm. The ulnar nerve is then circumferentially freed throughout its course within the incision ( Fig. 26B.9 ). Moving distally from Osborne’s ligament, the first and second motor branches to the FCU should be identified and protected.
The medial antebrachial cutaneous and ulnar nerves are retracted posteriorly, and the medial intermuscular septum is transected 4 cm from the medial epicondyle. The transected portion of the septum is reflected distally for later use as a sling during ulnar nerve transposition ( Fig. 26B.10 ). It should be noted that the distal portion of the medial intermuscular septum should be left attached to the medial epicondyle. Vessels in this area must be coagulated to prevent hematoma formation.
With the medial antebrachial cutaneous and ulnar nerves still retracted posteriorly, the UCL is identified. The origin of the flexor digitorum sublimis (FDS) is reflected off the sublime tubercle of the ulna, exposing the entire UCL. The dissection of the FDS away from the underlying ulna and UCL should proceed in a distal to proximal direction, being careful not to detach the flexor-pronator mass from the medial epicondyle. A small Hohmann retractor is placed on the radial side of the ulna to retract the fibers of the FDS away from the UCL. The anterior band of the UCL is split in line with its fibers, and the ligament is inspected for injury ( Fig. 26B.11 ). The split in the ligament also allows for visualization of the joint line, which is crucial for drilling of the ulnar tunnel. If intraligamentous calcifications are present, they are removed at this point. Furthermore, if an open posteromedial decompression is planned, it is also performed at this point, as described earlier.
The ulnar tunnel is then created by drilling two converging 3.5-mm tunnels at the sublime tubercle, approximately 5 to 7 mm distal to the joint line. The first tunnel is placed posteriorly, while the second tunnel is placed anteriorly. Care should be taken not to violate the joint surface when drilling this tunnel. The tunnel is completed using #1 and #2 curved curettes. A Hewson suture passer (Smith & Nephew, London, UK) is used to pass the graft through the ulnar tunnel.
The humeral tunnel is a Y-shaped tunnel. It is created by first drilling a 3.5-mm tunnel beginning at the humeral origin of the UCL. Two more converging tunnels are placed on the posterior aspect of the medial epicondyle, so that they both connect with the first tunnel. All three tunnels in the humerus are connected using a combination of straight and curved curettes.
The graft is passed through the humeral tunnel in a figure-of-eight fashion. The elbow is flexed to 30 degrees, and tension is pulled on both limbs of the graft. Full elbow ROM is ensured before the graft is secured to the medial epicondyle. The graft is secured into place posterior to the medial epicondyle by placing five simple stitches using 0 Ti-Cron (Covidien). Each of these sutures should secure both limbs of the graft to the humeral periosteum. After the graft is secured posteriorly, the arm is placed into full extension. Additional graft tension is created by incorporating both limbs of the graft into the repair of the split that was previously created in the UCL ( Fig. 26B.12 ). This is also accomplished by using 0 Ti-Cron. Excess graft is sharply removed.
After the graft is sutured into place, the ulnar nerve is transposed anteriorly. The nerve is placed anterior to the medial epicondyle, and the reflected portion of the medial intermuscular septum is used to create a loose sling ( Fig. 26B.13 ). The sling is secured to the forearm fascia using 4.0 Ti-Cron (Covidien). Care must be taken not to strangulate the ulnar nerve beneath the sling. Osborne’s ligament is repaired with 0 Ti-Cron (Covidien) to prevent the ulnar nerve from subluxating posteriorly into the cubital tunnel.
The FCU fascia is closed with 0 Ti-Cron (Covidien). Care must also be taken while closing the FCU fascia, so as not to strangulate the ulnar nerve. A 2-cm opening between the two heads of the FCU should be left for passage of the ulnar nerve back into its muscular bed in the forearm. Another 0 Ti-Cron (Covidien) is used to sew a small portion of the medial portion of the triceps over the graft on the posterior aspect of the humerus. This minimizes bleeding and prevents anterior subluxation of the medial head of the triceps. A Hemovac drain is placed, and the tourniquet is deflated. When meticulous hemostasis is obtained, the skin is closed with 2.0 Vicryl followed by 3.0 running Prolene. Sterile dressing is applied, and a posterior splint is placed with the arm in 90 degrees of flexion. The splint will remain on for 5 days. After the splint is removed, the extremity is placed in a hinged elbow brace, which is removed during physical therapy sessions to perform aggressive ROM exercises.
Ulnar Collateral Ligament Reconstruction Outcomes
Overall, UCL reconstruction has been successful in allowing patients to return to play. reported results on 743 patients undergoing UCL reconstruction with at least 2-year follow-up. Eighty-three percent of patients returned to the same level of play or higher. When considering Major League Baseball players, 75.5% returned to the same level of play. Minor league baseball players demonstrated a 73% return to the same level of play or higher. Eighty-seven percent of collegiate baseball players returned to play either collegiate or professional baseball after UCL reconstruction. Eighty-three percent of high school athletes returned to previous level of competition. Additionally, there was a 20% overall complication rate in the study. Sixteen percent of all patients undergoing UCL reconstruction experienced transient ulnar nerve neuropraxia, with the vast majority resolving by 6 weeks.
reported 10-year results on the same cohort of patients. Ninety percent of pitchers were able to return to the same level of play or higher. Overall, baseball players who returned to play were able to continue their careers for an average of 3.6 years. Ninety-three percent of patients were satisfied with their results after their playing careers were finished. Only 3% experienced persistent elbow pain.
Prevention in Youth Sports (Early Sports Specialization)
- Osama Elattar, MD
- Brian Busconi, MD
Abstract
Over the past few decades, there has been a continuous rise in the number of participants in overhead throwing sports. As a result, there has been a concomitant increase in the incidence of overuse elbow injuries. Common overuse injuries encountered in the throwing elbow include (1) ulnar collateral ligament tears; (2) ulnar neuritis; (3) flexor-pronator strain, tear, or tendinitis; (4) medial epicondyle apophysitis or avulsion; (5) valgus extension overload syndrome with olecranon osteophytes; (6) olecranon stress fractures; (7) osteochondritis dissecans of the capitellum; and (8) loose bodies ( ). Of extra concern is the apparent rise in elbow injuries to youth baseball pitchers. The number of ulnar collateral ligament (UCL) reconstructions (“Tommy John” surgeries) is increasing, especially in young baseball pitchers ( ). With the absence of national database documenting the total number of elbow surgeries in baseball pitchers, the experience at the Andrews Sports Medicine and Orthopedic Center supports the belief of increased rates of elbow injuries to youth pitchers ( ). For youth baseball elbow injuries, there are four main risk factors recognized in the literature: number of pitches thrown, pitch type, pitching mechanics, and physical condition of the player ( ). Of these four factors, the number of pitches thrown has the strongest correlation to youth pitching injuries ( ). Prevention of injury to the UCL is focused on addressing the risk factors for injury.
Keywords: elbow injuries, prevention, risk factors, throwing, ulnar collateral ligaments
Introduction
- ▪
Over the past few decades, there has been a continuous rise in the number of participants in overhead throwing sports. As a result, there has been a concomitant increase in the incidence of overuse elbow injuries.
- ▪
Common overuse injuries encountered in the throwing elbow include
- ▪
(1) ulnar collateral ligament tears; (2) ulnar neuritis; (3) flexor-pronator strain, tear, or tendinitis; (4) medial epicondyle apophysitis or avulsion; (5) valgus extension overload syndrome with olecranon osteophytes; (6) olecranon stress fractures; (7) osteochondritis dissecans (OCD) of the capitellum; and (8) loose bodies ( ; ).
- ▪
Of extra concern is the apparent rise in elbow injuries to youth baseball pitchers. The number of ulnar collateral ligament (UCL) reconstructions (“Tommy John” surgeries) is increasing, especially in young baseball pitchers ( ; ).
- ▪
With the absence of national database documenting the total number of elbow surgeries in baseball pitchers, the experience at the Andrews Sports Medicine and Orthopedic Center supports the belief of increased rates of elbow injuries to youth pitchers ( Table 26C.1 ) ( ).
Table 26C.1
Ulnar Collateral Ligament Reconstructions
Year
Total ( n )
Youth and High School
1994
6
0
0
1995
21
2
10
1996
31
1
3
1997
23
1
4
1998
43
5
12
1999
65
12
18
2000
93
17
18
2001
93
17
18
2002
110
19
17
2003
172
45
26
2004
174
35
20
2005
153
42
27
2006
140
36
26
2007
125
38
30
2008
103
33
32
2009
121
34
28
2010
131
41
31
Total
1607
374
23
Adapted from Andrews Sports Medicine and Orthopedic Center and Fleisig GS, Andrews JR. Prevention of elbow injuries in youth baseball pitchers. Sports Health . 2012;4(5):419-424.
- ▪
The increase in the number of surgeries and percent of surgeries in young baseball pitchers may represent a true increase in injury incidence, improved diagnostics, or a combination of these two factors ( ).
- ▪
For youth baseball elbow injuries, there are four main risk factors recognized in the literature: number of pitches thrown, pitch type, pitching mechanics, and physical condition of the player ( ).
- ▪
Of these four factors, the number of pitches thrown has the strongest correlation to youth pitching injuries ( ). Prevention of injury to the UCL is focused on addressing the risk factors for injury.
Youth Sports Participation and Specialization
In the United States, there has been an increase in sports participation across all age groups over the past 15 years. Concomitantly, there has been an increase in early year-round training in a single sport. Between the ages of 6 and 18 years, about 27 million U.S. youths participate in team sports, and 60 million participate in some form of organized athletics ( ). In 1997, 9% of children younger than 7 years of age participated in organized sporting activities, compared with 12% in 2008 ( ). Additionally, there has been an increase in high school sports participation in many sports, including baseball, soccer, softball, tennis, and swimming.
Despite the advantages of maximizing healthy physical activities in the preadolescent and adolescent age groups, the debate continues about when, how, and why a young person should become a “single-sport athlete.”
Single-sport specialization has become increasingly popular among many coaches and parents with many factors contributing to this trend, including the desire to pursue scholarships, potential professional status, the ability to label a young athlete as elite at an early age, and public perception of the value of elite athletic competition and financial rewards for elite athletes.
The American Orthopaedic Society for Sports Medicine (AOSSM) Consensus meeting defined early sports specialization, or early single-sport specialization by the following three criteria ( ):
- 1.
Participation in intensive training or competition in organized sports more than 8 months per year (essentially year round) ( )
- 2.
Participation in one sport to the exclusion of participation in other sports (limited free play overall) ( )
- 3.
Involving prepubertal (seventh grade or roughly age 12 years) children
The degree of sports specialization can be defined as low, moderate, or high based on the number of definition components to which a young athlete may respond in a positive way ( ) ( Table. 26C.2 ).
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