Elbow Medial Ulnar Collateral Ligament Repair Versus Reconstruction Versus Augmented Reconstruction: Where Do We Stand?

Abstract

Medial ulnar collateral ligament (MUCL) injuries of the elbow have increased over the past 2 decades, particularly among adolescent and young adult overhead throwing athletes. Over time, operative techniques for MUCL injuries have evolved, with the goals of improving time to return and rates of return to sport and meeting athlete-specific demands. The purpose of this review is to evaluate the state of surgical management of MUCL injuries, assessing indications, techniques, and outcomes. Surgical techniques reviewed included MUCL-augmented repair with internal bracing, traditional reconstruction, reconstruction augmented with internal bracing, and revision MUCL reconstruction. While MUCL reconstruction has been the gold standard of treatment, augmented reconstruction and repair techniques have shown promising outcomes; these strategies emphasize anatomic restoration, preservation of native tissue, and individualized patient selection.

Introduction

Medial ulnar collateral ligament (MUCL) injuries have become increasingly prevalent, particularly among throwing athletes, most attributed to overuse.^1,2 Between 2010 and 2019, 19 348 MUCL injuries were identified from a national sample, with the majority (54%) occurring in athletes aged 15 to 19 years. ³ From 2010 to 2023, the annual number of MUCL surgeries performed on Major and Minor League Baseball pitchers increased from 90 to 232 surgeries. ⁴ This trend has been identified outside of professional baseball, as well, with the data demonstrating a 193% increase in the number of MUCL reconstructions completed between 2002 and 2011. ² Given the increased number of MUCL injuries, there has been an increased emphasis on ideal treatment and surgical techniques have evolved.

The MUCL complex consists of 3 major components: the anterior oblique ligament, the posterior oblique ligament, and the transverse ligament. The anterior bundle (referred to as the MUCL) confers the strongest restraint to valgus force about the elbow. ⁵ Microtrauma sustained by the MUCL can progress asymptomatically for an extended period. ⁶ Furthermore, poor throwing mechanics, overuse, and flexor-pronator weakness can make the MUCL particularly susceptible to injury. ⁷

Nonoperative management is a common approach for non-throwing athletes, especially in the setting of partial tearing. ⁸ Rest, physical therapy, and biologic therapies are the most common conservative treatments, with reported return to sport (RTS) rates ranging from 79.7% to 84%.^9,10 Rates of RTS with nonoperative treatment are higher in incomplete and more proximal MUCL tears.^9,10 Operative management is typically indicated in higher-demand throwing athletes with full-thickness MUCL tears or in those with other tears that have failed nonoperative treatment. ⁸ In overhead athletes with full-thickness tears, surgical management has been associated with higher RTS rates, ranging from 75% to 91%.^10,11

Surgical management techniques for MUCL injuries continue to evolve. There are currently 3 options: standard reconstruction, repair augmented with an internal brace, and reconstruction augmented with an internal brace. Reconstruction was the primary surgical technique, first described by Frank Jobe, MD, in 1974 and published in 1986,^12,13 the Jobe technique facilitated RTS for high-demand overhead throwing athletes. The modified Jobe was later introduced with the aim of decreasing soft tissue and ulnar nerve disruption. ¹⁴ This led to the introduction of the docking technique, which enabled preservation of bone, prioritized protection of the ulnar nerve, and improved graft tensioning. ¹⁵ It has become the most common technique for MUCL reconstruction. ¹⁶ Augmented repair techniques that utilize structural reinforcement for a primary repair are also available. When tissue quality is sufficient, augmented repairs can be performed for proximal, distal partial-thickness, or full-thickness MUCL tears. ¹⁷

Ultimately, with heightened demands being placed on young throwing athletes and the concomitant rising rates of injuries, an increased focus on surgical management of MUCL injuries has developed. It is therefore important to review where the field of MUCL surgery stands.

MUCL Augmented Repair

MUCL repair was originally described in 1981 by Norwood et al in a series of 4 patients. ¹⁸ None were high-level throwing athletes, and all were reported to have had relatively good outcomes. Though initial studies suggested that repair yielded poor outcomes with low rates of RTS, more recent literature has suggested that under the correct circumstances, augmented repair of the MUCL may yield adequate results. ¹⁹

Augmented MUCL repair involving the addition of a collagen-coated suture tape was first described by Dugas et al. ²⁰ Its rationale is (1) to provide an additional physical restraint to the valgus stress experienced by the MUCL during overhead throwing and (2) to biologically enhance ligamentous healing. Augmented repair involves a combination of suture anchors loaded with collagen-coated suture tape, with subsequent passing of the suture through the ligament in a mattress fashion. ²⁰ The native tendon itself is also closed using a suture to complete the internal brace.

An average RTS of approximately 7 months makes augmented repair an appealing option for high-level baseball players.^12,17 Indications for repair include adequate tissue quality and partial or full-thickness tears of the MUCL. Complete mid-substance tearing of the MUCL is a relative contraindication to repair. ¹² Other contraindications include tissue loss or considerable degeneration of tissues. ²⁰ Ultimately, in the correct circumstances, augmented repair of the MUCL can lead to positive patient outcomes and an expedited time to RTS.

MUCL Reconstruction

When Jobe first published on MUCL reconstruction in 1986, the technique involved detachment of the flexor-pronator (F-P) mass to visualize the MUCL bundle and provide access for tunnel formation and figure-of-8 graft configuration. ¹³ Since then, several iterations of Jobe’s reconstruction technique have emerged. The original technique demonstrated high rates of ulnar neuropathy, required revisions, and detrimental effects on RTS. ¹³ Yet this Tommy John surgery set the stage for future reconstruction techniques, including variations in surgical approach, graft selection, tunnel positioning, and graft fixation.

Graft selection for MUCL reconstruction is most commonly the palmaris longus autograft, which is used in as many as 67% of modern MUCL reconstructions, followed by gracilis and semitendinosus autografts. ¹⁶ Graft configurations include the figure-of-8, triangular, and linear configurations. Utilized in the original Jobe technique, the figure-of-8 construct passes 1 free end of the graft through 2 ulnar and 2 medial epicondyle tunnels and then is sutured and tensioned to itself. ¹³ This is the most widely employed construct in MUCL reconstruction today. ¹⁶ Triangular configurations involve passing the graft through 2 ulnar tunnels and a singular humeral tunnel, while the linear single strand is fixated directly between a single ulnar and single humeral point.

The modified Jobe technique was introduced by Smith et al in a cadaveric study that demonstrated the safety of F-P mass splitting as opposed to detachment. ²¹ It utilizes 2 anterior humeral tunnels that connect to a central tunnel forming a Y shape, in which 2 limbs form a figure-of-8 graft configuration through humeral and ulnar tunnels. ²¹ In contrast to the original Jobe technique, there is no requirement for ulnar nerve transposition. Importantly, there was no report of muscle denervation in the initial trial. ²² A 2024 study found that the modified Jobe technique was the most commonly utilized approach, performed in nearly 37% of cases from 2002 to 2022. ¹⁶ With this technique, RTS for throwing athletes has been shown to be approximately 12 months, with up 70% of patients achieving good or excellent outcomes on the Conway-Jobe scale. ²² The arthroscopic assisted split-thickness muscle-splitting intermediate (ASMI) technique is a modified Jobe-style reconstruction that includes limited elbow arthroscopy followed by open MUCL reconstruction. ²³ In this technique, the F-P mass is preserved, and the ulnar nerve is transposed subcutaneously rather than sub muscularly, with graft fixation done using a figure-of-8 configuration. ²³ Among a cohort of athletes undergoing MUCL reconstruction with the ASMI technique, RTS to the same or higher level was achieved in 81%, with mean time to competitive throwing of 9.8 months. ²³

The docking technique, introduced in response to limitations of the original Jobe technique, involves the creation of 2 converging ulnar tunnels and a single longitudinal humeral tunnel creating a triangular graft configuration. ²⁴ Its goals were similar to those of the modified Jobe technique and reduced the number of tunnels used in an effort to preserve bone stock and simplify graft tensioning. ²⁴ Today, the docking technique is used in the majority of MUCL reconstructions. ¹⁶ In a series of 36 patients, 92% of patients returned to their previous level of competition and achieved excellent outcomes on the Conway-Jobe scale at 3-year follow-up. ²⁴ When compared to the modified Jobe technique, return-to-play outcomes and RTS times were not significantly different, with comparably low rates of complications. ²² Many variations of the triangular docking technique have also been described, including 3-strand and 4-strand docking techniques, each with outcomes that were comparable to the standard approach.

Modified Jobe and docking-based constructs have consistently demonstrated a high rate of RTS, often exceeding 90% in the overhead athlete.^24,25 Yet, the RTS time remains prolonged at 12 to 18 months.^4,26 This has important implications for athletes and surgical decision-making and has driven continued interest in techniques aimed at accelerating this RTS process while maintaining favorable clinical outcomes.

MUCL Augmented Reconstruction

MUCL augmented reconstruction involves the addition of a suture tape or internal brace to enhance the strength and healing of the reconstruction. Augmented MUCL reconstruction with an anatomic technique with excellent results has been described by Camp et al. ²⁷ In this technique, the native ligament repair is first completed and a palmaris longus autograft is subsequently utilized and augmented with a suture tape. The folded end of the graft and internal brace is secured into a humeral socket, allowing increased tendon-to-bone contact and less suture in the socket compared to the traditional docking technique. The distal end of the graft and internal brace are fixed through a combination of sutures and suture anchors. Camp et al subsequently reported on 34 baseball players who underwent augmented MUCL reconstruction using this technique ²⁸ ; they found a mean RTS of 10 months in 100% of players. Overall success rate was 97%, with 1 graft re-rupture at 3 years post-op. These results suggest that MUCL augmented reconstruction may be a reliable surgical option for high-level overhead athletes. This is a rapidly growing option for MUCL surgery, and additional clinical outcome studies are forthcoming.

Revision UCL

Following primary reconstruction, patients may sustain an injury to the MUCL that necessitates revision reconstruction. Revision surgery has been found to occur at a mean of approximately 3.75 years after initial reconstruction. ²⁹ However, the etiology of primary MUCL reconstruction failure is largely unknown, with the literature failing to identify any clearly associated factors. ³⁰ For instance, graft type used during index MUCL reconstruction has not been found to be significantly associated with subsequent need for revision. ³⁰

Outcomes following revision MUCL surgery are generally inferior to those of primary reconstruction. Erickson and colleagues found that less than 60% of pitchers who underwent revision MUCL reconstruction returned to the same level of play, ³⁰ compared to the 90% of pitchers who returned to the same level of play following primary reconstruction. Furthermore, time to return to the same level of play following revision MUCL reconstruction was significantly extended compared to primary reconstruction, with pitchers returning to the same level of play on average at the 20-month postoperative mark.

Several grafts may be used when performing revision MUCL reconstruction. One study of 191 professional baseball pitchers found that the most commonly used grafts were the hamstring tendon autograft (47%) and the palmaris longus autograft (35%). ³⁰ In this study, the docking technique and modified Jobe technique were used equally in the revision MUCL setting. ³⁰ Ultimately, methods for revision MUCL reconstruction are evolving, with room for improvement in outcomes.

Conclusions

As the prevalence of MUCL injuries among throwing athletes continues to rise, particularly in younger athletes, continued refinement of surgical techniques will be of utmost importance. Enhanced reconstruction techniques involve repairing the native ligament and adding in internal brace along with the new graft. MUCL injury treatment is evolving toward reductions in postoperative recovery times and improvements in RTS at the same or higher level, through patient selection and consideration of postoperative patient goals.