Patients with medial instability usually report medial elbow pain, decreased strength during overhead activity. Sometimes there may be symptoms of ulnar neuropathy from either acute or chronic UCL injury caused by edema/hemorrhage of the medial elbow or excessive traction on the nerve.

The UCL stability can be assessed with specific physical exam tests.

Patients with isolated UCL injury often have point tenderness 2 cm distal to the medial epicondyle, slightly posterior to the common flexor origin.

The “milking maneuver” involves having the patient apply a valgus torque to the elbow by pulling down on the thumb of the injured extremity with the contralateral limb providing stability [23]. With the modified milking maneuver, the examiner provides stability to the patient’s elbow and pulls the thumb to create a valgus stress on the UCL [24]. In cases of UCL insufficiency, these tests result in pain and widening at the medial joint line.

O’Driscoll and coworkers described the moving valgus stress test, in which the valgus torque is maintained constantly to the fully flexed elbow and then quickly extends the elbow [25]. This test is positive if medial elbow pain is elicited and has a 100 % sensitivity and 75 % specificity [25]. The abduction valgus stress test is performed by stabilizing the patient’s abducted and externally rotated arm with the examiners axilla and applying a valgus force to the elbow at 30° of flexion. Testing with the forearm in neutral rotation has been shown to elicit the greatest valgus instability [26]. A positive test results in medial elbow pain and widening along the medial joint line. Even so, valgus laxity can be subtle on physical exam, and the range of preoperative detection is between 26 % and 82 % of patients [27, 28]. Furthermore, Timmerman and colleagues found valgus stress testing to be only 66 % sensitive and 60 % specific for detecting abnormality of the anterior bundle of the UCL [29].

Initial treatment consists of rest, anti-inflammatory medications, icing, and bracing.

Literature report 42–50 % success rate in returning to previous sport activities after different conservative treatment protocols [30, 31].

These modest results lead to consider surgical treatment, particularly in high-level athletes as treatment of choice.

Surgical treatment for UCL tears has evolved over the time. Early surgical management of UCL insufficiency consisted of transferring the anterior oblique ligament anteriorly and superiorly when the UCL was present but attenuated [20], but this technique was abandoned because the remaining attenuated ligament is believed to be weaker as the result of the repeated microtrauma and because its transferred position is not functionally isometric and could lead to a flexion contracture. This is not acceptable in the high-level athlete.

Primary ligament repair for acute injuries had been supported [32, 33].

Most ligamentous avulsions have traditionally been treated by reattaching the ligament to bone through drill holes, while midsubstance ruptures were repaired primarily [34].

UCL repair is considered only in case of avulsion injuries in younger athletes performing surgery soon after injury and having MRI showing complete avulsion from the bone [35].

In adults, also in acute events, it is frequent to find an intrasubstance damage of the UCL and the reconstruction must be considered.

Conway et al. [32] reported the relative prevalence of injury UCL for locations in 70 athletes with acute UCL injuries: 87 % of the lesions were midsubstance, 10 % were avulsions of the ulna, and only 3 % were avulsions from the humerus [32].

The ability to return to sports at the same level as before injury was reported by Conway et al. to be better with UCL reconstruction with the use of a free graft compared with primary repair [32].

Azar et al. [27] also found better results with UCL reconstruction (81 % able to return to play at the same or higher level) compared with primary UCL repair (63 % return to play at the same or higher level).

Autografts or allografts can be used to perform UCL reconstruction. The graft that can usually be used are:

Dr. Frank Jobe was the first in 1986 to report on a reconstruction technique of MCL [37]. It is often called “Tommy John” surgery after that Los Angeles Dodgers pitcher was the first athlete to undergo this procedure in 1974. Dr. Frank Jobe used bony tunnels in the humerus and ulna to secure a free graft. Exposure of the ligament was achieved through transection of the common flexor- pronator muscle group, from the medial epicondyle, combined with a submuscular ulnar nerve transposition. The ligament was reconstructed by the use of a tendon graft woven through three drill holes in the medial epicondyle and two drill holes in the ulna, in the form of a figure eight, and sutured to itself.

Conway et al. [32] reported that 68 % of patients returned to the previous level of sports participation with this reconstruction technique. There was a high incidence (21 %) of ulnar nerve symptoms after this procedure, requiring a revision procedure of the ulnar nerve in 58 % of these patients.

To minimize trauma to the flexor-pronator muscle group and reduce the incidence of ulnar nerve symptoms, Smith et al. [38] in 1996 described a more limited approach, which involved splitting the flexor-pronator muscle group instead of dividing it completely from the medial epicondyle. Muscle splitting approach is created by incising the raphe of the flexor carpi ulnaris and then is applied valgus stress. Converging 3.2-mm drill holes are made in the ulna anterior and posterior to the sublime tubercle with a minimum 5-mm bridge. A 4.5-mm drill hole is made at the site of the anatomic origin of the anterior bundle of MCL on medial epicondyle that does not penetrate the posterior cortex. A 3.2-mm drill hole is placed just anterior to the epicondylar attachment of the medial intermuscular septum and directed to communicate with the 4.5-mm drill hole in the epicondyle. A second 3.2-mm drill hole is made in the anterosuperior surface of the epicondyle approximately 1 cm from the previous 3.2-mm hole.

The ipsilateral palmaris longus is harvested through a series of small transverse incisions beginning at the distal flexor crease of the wrist. The graft is passed through the proximal ulnar bone tunnel and through medial epicondyle in a figure-eight configuration. With the elbow placed with varus stress, 60° of elbow flexion, and the forearm in supination, tension is applied to the graft. The ulnar side of the graft is sutured to the remnants of the ulnar collateral ligament adjacent to the sublime tubercle. The proximal limb of the graft is sutured to the medial intermuscular septum outside the drill hole. Simple sutures are placed in the crossing limbs of the graft which further tension graft and enhances fixation.

With this modified technique, it was unnecessary to mobilize and transpose the ulnar nerve routinely.

Good results with this modified Jobe technique, in which a muscle-splitting approach is used for exposure, have been reported; Azar et al. [27] reported that 79 % of patients had returned to previous levels of sporting competition, and Thompson et al. [28] reported a rate of 82 %.

Another alternative to transecting the flexor-pronator mass that has been used with good success was elevating the flexor-pronator tendon without detaching or splitting it [39].

In 2001, Altchek et al. [40] and Rohrbough et al. [41] in 2002 described a new reconstruction technique called “docking technique.”

The docking technique is a modification of the Jobe technique that simplifies graft passage, tensioning, and fixation. The exposure is obtained by muscle-splitting approach.

This reconstruction is based on a single medial epicondylar drill hole and two drill holes in the ulna similar to the Jobe technique. Humeral tunnel position is located in the anterior half of the medial epicondyle at the anatomic insertion of the native MCL similar to the Jobe technique depth of 15 mm using a 4-mm bur or drill. Two exit tunnels separated by 5 mm to 1 cm.

Graft is passed through the ulnar tunnel from anterior to posterior. Posterior limb of the graft is passed into the humeral tunnel. Final length of the anterior limb of the graft is determined by placing it adjacent to the humeral tunnel and visually estimating the length of the graft that would allow the graft to be tensioned within the humeral tunnel.

A No. 1 braided nonabsorbable suture is placed in a Krackow fashion. Excess graft is excised and graft limb is passed into the humeral tunnel with sutures exiting the small tunnels. Graft tensioning is performed by placing the elbow through a full range of motion with varus stress placed on the elbow. Sutures are tied over the bony bridge on the humeral epicondyle with the elbow in 60° of flexion, supination, and varus stress applied.

Medial epicondylar fixation is based on sutures tied over a bone bridge.

It has been suggested that the docking technique allows for better tensioning of the ligament graft. Rohrbough et al. [41] have reported that 92 % of their patients were able to return to preinjury levels of competition.

Afterwards, other MCL reconstruction techniques have been evaluated in the laboratory that reconstruct the central isometric fibers of the native ligament. Single drill holes located in the isometric and anatomic location of the anterior bundle of the MCL on the medial epicondyle and ulna have been proposed (single-strand technique), which would reduce the risk of injury to the ulnar nerve and simplify the procedure [42].

A single-strand technique minimizes the risk of injury to the ulnar nerve from a second more posterior drill hole and reduces trauma to the flexor-pronator muscles by allowing a more limited exposure.

Ahmad et al. described the use of an interference screw for fixation of a single-stranded tendon graft in blind osseous tunnels at the origin and insertion of the native ulnar collateral ligament [42]. Armstrong et al. determined the contribution of the central portion of the anterior bundle of the MCL to elbow stability and evaluated the effectiveness of a single-strand MCL reconstruction in restoring elbow stability [16].

Various fixation methods have been proposed and used: interference screws for ulna and humerus fixation; interference screw for ulna fixation and docking technique for humerus fixation (Dane TJ/hybrid), endobutton for ulnar fixation, and docking for humerus fixation.

In 2005, Armstrong et al. [43] reported a biomechanical comparison of the strength of four reconstruction techniques to that of the native ulnar collateral ligament in valgus stress. No difference in strength was found between the docking and single-strand medial collateral reconstruction with the use of an EndoButton for ulnar fixation. Both of these reconstruction methods were stronger than the interference screw or figure-eight technique. The optimal fixation method for a single-strand MCL reconstruction may require improved interference screws or a modified EndoButton procedure [43].