Review of Anatomy of the Medial Ulnar Collateral Ligament Complex of the Elbow

Graft choice and techniques used in elbow ulnar collateral ligament reconstruction over the last 20 years: a systematic review and meta-analysis

BACKGROUND

Elbow medial ulnar collateral ligament (mUCL) injuries have become increasingly common, leading to a higher number of mUCL reconstructions (UCLR). Various techniques and graft choices have been reported. The purpose of this study was to evaluate the prevalence of each available graft choice, the surgical techniques most utilized, and the reported complications associated with each surgical method.

METHODS

A systematic review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysesguidelines. We queried PubMed/MEDLINE, Embase, Web of Science, and Cochrane databases to identify all articles that included UCLR between January 2002 and October 2022. We included all studies that referenced UCLR graft choice, surgical technique, and/or ulnar nerve transposition. Studies were evaluated in a narrative fashion to assess demographics and report current trends in utilization and complications of UCLR as they pertain to graft choice and surgical techniques over the past 20 years. Where possible, we stratified based on graft and technique.

RESULTS

Forty-seven articles were included, reporting on 6671 elbows. The cohort was 98% male, had a weighted mean age of 21 years and follow-up of 53 months. There were 6146 UCLRs (92%) performed with an autograft and 152 (2.3%) that utilized an allograft, while 373 (5.6%) were from mixed cohorts of autograft and allograft. Palmaris longus autograft was the most utilized mUCL graft choice (64%). The most utilized surgical configuration was the figure-of-8 (68%). Specifically, the most common techniques were the modified Jobe technique (37%), followed by American Sports Medicine Institute (ASMI) (22%), and the docking (22%) technique. A concomitant ulnar nerve transposition was performed in 44% of all patients, with 1.9% of these patients experiencing persistent ulnar nerve symptoms after ulnar nerve transposition. Of the total cohort, 14% experienced postoperative ulnar neuritis with no prior preoperative ulnar nerve symptoms. Further, meta-analysis revealed a significantly greater revision rate with the use of allografts compared to autograft and mixed cohorts (2.6% vs. 1.8% and 1.9%, P = .003).

CONCLUSIONS

Most surgeons performed UCLR with palmaris autograft utilizing a figure-of-8 graft configuration, specifically with the modified Jobe technique. The overall rate of allograft use was 2.3%, much lower than expected. The revision rate for UCLR with allograft appears to be greater compared to UCLR with autograft, although this may be secondary to limited allograft literature.

Dual Bracing for Ulnar Collateral Ligament Injuries Restores Native Valgus Laxity and Native Medial Joint Gapping of the Elbow

Background

Despite growing evidence on the role of the posterior ulnar collateral ligament (pUCL) in elbow stability, current ligament bracing techniques are mainly focused on the anterior ulnar collateral ligament (aUCL). A dual-bracing technique combines the repair of the pUCL and aUCL with a suture augmentation of both bundles.

Purpose

To biomechanically assess a dual-bracing approach addressing aUCL and pUCL for humeral-sided complete UCL lesions to restore medial elbow laxity without overconstraining.

Study Design

Controlled laboratory study.

Methods

A total of 21 unpaired human elbows (11 right, 10 left; 57.19 ± 11.7 years) were randomized into 3 groups to compare dual bracing with aUCL suture augmentation and aUCL graft reconstruction. Laxity testing was performed with 25 N applied 12 cm distal to the elbow joint for 30 seconds at randomized flexion angles (0°, 30°, 60°, 90°, and 120°) for the native condition and then for each surgical technique. A calibrated motion capture system was used for assessment, allowing the 3-dimensional displacement during the complete valgus stress cycle between the optical trackers to be quantified as joint gap and laxity. The repaired constructs were then cyclically tested through a materials testing machine starting with 20 N for 200 cycles at a rate of 0.5 Hz. The load was increased stepwise by 10 N for 200 cycles until displacement reached 5.0 mm or complete failure occurred.

Results

Dual bracing and aUCL bracing resulted in significantly (P = .045) less joint gapping at 120° of flexion compared with aUCL reconstruction. No significant differences in valgus laxity were found among the surgical techniques. Within each technique, there were no significant differences between the native and the postoperative state in valgus laxity and joint gapping. No significant differences between the techniques were observed in cycles to failure and failure load.

Conclusion

Dual bracing restored native valgus joint laxity and medial joint gapping without overconstraining and provided similar primary stability regarding failure outcomes as established techniques. Furthermore, it was able to restore joint gapping in 120° of flexion significantly better than aUCL reconstruction.

Clinical Relevance

This study provides biomechanical data on the dual-bracing approach that may help surgeons to consider this new method of addressing acute humeral UCL lesions.

Substantiation of safe and effective arthroscopic approaches to the elbow joint in case of enthesopathy of the distal humerus

Background: With the development of arthroscopic surgical techniques, diagnostic and therapeutic possibilities have significantly expanded, but they have not become widely used in everyday clinical practice in the treatment of elbow joint pathology. This is due to the small volume of the joint, the close location of the neurovascular formation and the complexity of manipulation. Elbow arthroscopy is a dynamic procedure with a change in the ratio of neurovascular structures and portals in different elbow positions. The risk of damage to neurovascular formations during arthroscopy of the elbow joint is up to 14%. Purpose: determination of the safest areas promising for the formation of arthroscopic approaches to the elbow joint in the treatment of patients with enthesopathy of the distal humerus.. Methods: To achieve this goal, a complex topographic- anatomical and clinical study was performed on 30 non-fixed anatomical preparations of the upper limb, which included 4 stages, where the topographic and anatomical features of the tendon-muscular and neurovascular structures forming the elbow joint were studied, depending on the angle of flexion of the elbow joint at 3 different levels: level I - 5 cm above the joint space, level II - joint space, level III - the neck of the radius, additionally the above structures were studied using MRI studies in 30 patients. Results: When the elbow joint is flexed to 90, the brachial artery at level I moves away from the bone and is located at a distance from 27,8 (27.7-28,1) mm to 28,6 (28,4-28,7). The radial nerve at the II level from СMEL is located at 16,4 (16,5-18,8) mm. Median nerve from СMEL by 17,5 (16,6-18,1) mm. The brachial artery is 23,7 (20,522,8) mm distant from the СMEL. The anterior bundle of the MCL has: an average proximal width of 6,2 1,4 mm, an average width of the middle part of 6,5 1,5 mm, an average distal width of 9,3 1,4 mm. The average area of attachment on the medial epicondyle of the humerus is 45,5 9,3 mm, it has a rounded shape. The radial collateral ligament has an average length of 20,5 1.9 mm and a bundle width of 5,2 0,8mm. The average area of attachment on the humerus is 13,6 mm. The average area of ECRB on the lateral epicondyle of the humerus was 53,1 3,7mm. The mean area of the FCR on the medial epicondyle was 58,3 6.3mm. The distance from the entrance of the deep branch of the radial nerve to the canalis sapinatorius to the joint space is 28 (25,529,6) mm. Conclusion: The results of this study allow the operating surgeon to decide on the choice and placement of arthroscopic access to the elbow joint, which in turn helps to minimize the risk of damage to neurovascular structures.

Intersurgeon Consistency of Ulnar Collateral Ligament Repair With Internal Brace: A Biomechanical Analysis

BACKGROUND

Injury to the ulnar collateral ligament (UCL) of the medial elbow has been treated successfully with ligament repair augmented with internal brace. Previous work has shown that this procedure does not overconstrain the ulnohumeral joint; however, the procedures were conducted by a single surgeon, which controlled for anchor placement and graft tensioning.

PURPOSE/HYPOTHESIS

Our purpose was to evaluate the reproducibility of contact mechanics and joint torque after UCL repair with internal brace as performed by different surgeons compared with repair by a single surgeon. It was hypothesized that there would be no significant difference in elbow contact mechanics, valgus torque, or torsional stiffness between the 2 groups.

STUDY DESIGN

Controlled laboratory study.

METHODS

Nine pairs of fresh-frozen cadaveric elbows were tested biomechanically under 3 conditions: UCL-intact (UCL-I), UCL-deficient (UCL-D), and UCL-repaired with internal brace augmentation (UCLR-IB). For each pair, 1 elbow was repaired by a single surgeon, and the contralateral elbow was repaired by 1 of 9 other surgeons. Testing consisted of valgus torsion between 0° and 5° with the elbow positioned at 90° of flexion. Ulnohumeral contact mechanics and overall joint torque and stiffness were measured and compared between surgeon groups.

RESULTS

There were no statistically significant differences between the single-surgeon and multiple-surgeon groups regarding contact area (P = .83), contact force (P = .27), peak pressure (P = .26), or peak force (P = .30); however, contact pressure was significantly affected (P = .02) by surgeon group. Compared with UCL-I, both UCL-D and UCLR-IB conditions had a significant overall effect on contact area (P = .004) and contact force (P = .05); however, contact pressure (P = .56), peak pressure (P = .27), and peak force (P = .24) were not affected by injury condition. Measurements of elbow torque (P = .28) and stiffness (P = .98) were not significantly different between surgeon groups.

CONCLUSION

UCL repair with internal brace provided consistent results among several surgeons when compared with a single surgeon. The procedure did not lead to joint overconstraint while also returning the ligament to near-intact levels of resisting valgus stress.

CLINICAL RELEVANCE

UCL repair with internal brace augmentation is a reproducible surgical technique that has good clinical outcomes in the literature.

Medial Ulnar Collateral Ligament Injuries in Contact Athletes

PURPOSE OF REVIEW

The purpose of this article is to review medial ulnar collateral ligament (UCL) injuries in contact athletes. UCL injuries in overhead throwing athletes are typically chronic attenuation due to repetitive valgus stress on the elbow during the throwing motion. As such, UCL reconstruction is commonly performed for these athletes. In contrast, UCL injuries in contact athletes are usually acute ligament tears or avulsions of a ligament with otherwise normal tissue. Nonoperative treatment is typically the first-line treatment for partial injuries. UCL repair may work well for acute complete injuries and may avoid the donor site morbidity of UCL reconstruction.

RECENT FINDINGS

Most of the literature regarding UCL injuries have been performed in baseball players. Historically, UCL repair has had poor outcomes in baseball players due to the chronic ligament attenuation. Therefore, much of the recent literature has focused on outcomes of UCL reconstruction, which are generally excellent. However, there is a paucity of literature studying outcomes of UCL injuries in contact athletes and those studying UCL repair. One recent study looked at a new technique for UCL repair with collagen-coated fiber tape augmentation in baseball players and found good short-term outcomes. UCL injuries in contact athletes occur typically as acute tears or avulsions. While UCL reconstruction has typically been recommended as the accepted treatment for UCL tears that require operative treatment, UCL repair may be a good alternative in contact athletes.

Muscle coordination retraining inspired by musculoskeletal simulations reduces knee contact force

Humans typically coordinate their muscles to meet movement objectives like minimizing energy expenditure. In the presence of pathology, new objectives gain importance, like reducing loading in an osteoarthritic joint, but people often do not change their muscle coordination patterns to meet these new objectives. Here we use musculoskeletal simulations to identify simple changes in coordination that can be taught using electromyographic biofeedback, achieving the therapeutic goal of reducing joint loading. Our simulations predicted that changing the relative activation of two redundant ankle plantarflexor muscles—the gastrocnemius and soleus—could reduce knee contact force during walking, but it was unclear whether humans could re-coordinate redundant muscles during a complex task like walking. Our experiments showed that after a single session of walking with biofeedback of summary measures of plantarflexor muscle activation, healthy individuals reduced the ratio of gastrocnemius-to-soleus muscle activation by 25 ± 15% (p = 0.004, paired t test, n = 10). Participants who walked with this “gastrocnemius avoidance” gait pattern reduced late-stance knee contact force by 12 ± 12% (p = 0.029, paired t test, n = 8). Simulation-informed coordination retraining could be a promising treatment for knee osteoarthritis and a powerful tool for optimizing coordination for a variety of rehabilitation and performance applications.

Fracture-Separation of the Medial Humeral Epicondyle Caused by Arm Wrestling: A Systematic Review

Background:

Arm wrestling is a popular sport in which various injuries have occurred, even in children.

Purpose:

To analyze reported fracture-separation of the medial humeral epicondyle (MHE) caused by arm wrestling to determine its mechanism and provide a current overview.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

The PubMed and Web of Science databases were searched using the terms “arm wrestling” and “humeral fracture” or “medial humeral epicondyle fracture”; and “sports” and “humeral fracture” or “medial humeral epicondyle fracture,” following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The inclusion criteria were English full-text articles on arm wrestling–induced MHE fracture that described patient characteristics and presented appropriate images. Studies with a lack of appropriate images or detailed description of the injury situation were excluded. The patient characteristics were evaluated, and the ratios of treatment selection and outcomes were evaluated using the chi-square test.

Results:

Included were 27 studies with a total of 68 patients, all boys with a mean age of 14.6 ± 1.24 years (based on n = 65, with 3 patients excluded from this calculation as no definitive age was provided). Boys aged 14 to 15 years accounted for 72% (49/68) of the cases. Fracture occurred suddenly during arm wrestling in 63 boys, while the other 5 boys experienced antecedent medial elbow pain. The match status at the time of injury, provided for 46 patients, was varied. In 31 boys with known match details, injury occurred when a participant suddenly added more force to change the match status. Eight patients displayed anterior and/or proximal displacement of the MHE fragment. Treatment was nonoperative in 25 patients and operative in 38 patients (n = 63, excluding 5 unknown patients). In 35 patients followed up for ≥3 months (mean, 17.6 ± 12.3 months), outcomes were not significantly different between the operative and nonoperative groups.

Conclusion:

MHE fracture-separation caused by arm wrestling occurred mostly in boys aged 14 to 15 years regardless of the match status. The likely direct cause is forceful traction of the attached flexor-pronator muscles. A relative mechanical imbalance during adolescence may be an underlying cause. A sudden change from concentric to eccentric contraction of the flexor-pronator muscles increases the likelihood of fracture occurrence.

Elbow Ulnar Collateral Ligament Injuries in Throwing Athletes: Diagnosis and Management

Ulnar collateral ligament (UCL) injuries of the elbow are common in overhead throwing athletes. With throwing, the elbow experiences substantial valgus stress and repetitive microtrauma can lead to injury. Increasing rates of injury among both youth and professional throwers has resulted in a "UCL epidemic." Ulnar collateral ligament reconstruction ("Tommy John Surgery") became a part of the public consciousness after Tommy John returned to professional baseball after a UCL reconstruction with Dr Frank Jobe for what was once considered a career-ending injury. Partial tears and some athletes with complete UCL injuries can be managed without surgery. Since the introduction of UCL reconstruction, technical modifications have aimed to decrease complications and increase return-to-play rates. Ulnar collateral ligament repair has reemerged as a potential surgical option for some throwers. Future prospective and comparative studies are necessary to better define the optimal operative treatment for these injuries.

Medial Ulnar Collateral Ligament Repair With Internal Brace Augmentation: Results in 40 Consecutive Patients

Background:

Medial ulnar collateral ligament (MUCL) repair has been proven to be effective in nonprofessional overhead-throwing athletes, with faster and higher rates of return to play (RTP) than the more traditional Tommy John reconstruction. Biomechanical studies and clinical data suggest that MUCL repair augmented with a collagen-coated internal brace may be an effective treatment option in this patient population.

Purpose:

To evaluate the functional outcomes of young nonprofessional athletes who underwent MUCL repair with internal brace augmentation for medial elbow instability. The hypothesis was that these patients will have high rates of RTP and improved functional outcomes.

Study Design:

Case series; Level of evidence, 4.

Methods:

Nonprofessional overhead athletes treated with MUCL repair with internal brace augmentation between 2015 and 2017 were prospectively evaluated for a minimum of 1 year. Preoperatively, all patients had evidence of medial elbow pain caused by MUCL insufficiency, as confirmed by signal changes on magnetic resonance imaging and valgus instability on arthroscopic examination. These findings did not allow them to participate in their chosen sport or profession, and each patient had failed nonoperative treatment. Postoperative outcomes were evaluated using the Overhead Athlete Shoulder and Elbow Score of the Kerlan-Jobe Orthopaedic Clinic. Complications were recorded and detailed.

Results:

A total of 40 nonprofessional overhead athletes were included in this study (35 men and 5 women; mean age, 17.8 years [range, 14-28 years]). The mean follow-up time was 23.8 months (range, 12-44 months). The mean postoperative Kerlan-Jobe Orthopaedic Clinic score was 92.6 (range, 64-100). Overall, 37 athletes (92.5%) returned to play or profession at the same level or higher at a mean time of 6.9 months (range, 2-12 months). Three patients did not RTP: 1 was limited by a concomitant medical diagnosis, and the other 2 chose not to resume athletics after the procedure but remained symptom free.

Conclusion:

In the nonprofessional athlete, primary MUCL repair with internal brace augmentation is a viable alternative to traditional repair techniques or reconstruction, allowing for a rapid RTP and promising functional outcomes.

Radiographic and MRI Assessment of the Thrower's Elbow

PURPOSE OF REVIEW

Throwing athletes are vulnerable to elbow injuries, especially in the medial elbow, related to high stress and valgus load in both acute and chronic settings as a result of this complex biomechanical action. This current review details the relevant anatomy and imaging features of common elbow pathology identified with radiographs and MRI in throwing athletes.

RECENT FINDINGS

Although elbow pathology in throwing athletes is well documented, advances in imaging technology and technique, particularly with MRI, have allowed for more detailed and accurate imaging description and diagnosis. Pathology of thrower's elbow occurs in predictable patterns and can be reliably identified radiologically. Clinical history and physical examination should guide radiologic evaluation initially with radiographs and followed by an MRI optimized to the clinical question. Constellation of clinical, physical, and radiologic assessments should be used to guide management.

Acute elbow dislocation: comparison between magnetic resonance imaging and intra-operative finding of ligament injury

PURPOSE

The aim of this current study was to assess elbow ligament tears after dislocation using magnetic resonance imaging (MRI) and to correlate any pre-operative imaging with intra-operative findings of elbow ligament tears.

METHODS

We prospectively included 32 patients with acute elbow dislocation investigated by MRI at a means of five days from dislocation. A simple elbow dislocation was diagnosed in 14 patients (44%); associated bone injuries were identified in 18 elbows (56%). Surgical repair of elbow ligaments was carried out in 23 patients, and nine cases were treated non-operatively. A blinded MRI evaluation of all 32 elbows was performed by an orthopaedic surgeon (rater 1) and a musculoskeletal radiologist (rater 2).

RESULTS

Inter-rater agreement for MRI evaluation of 32 was poor for lateral ulnar collateral ligament (LUCL) tears, fair for radial collateral ligament (RCL), moderate for annular ligament (AL), and fair for ulnar collateral ligament (UCL). All tears were reported as complete by rater 1; 13/32 partial tears were identified by rater 2 (LUCL = 2, RCL = 2, UCL = 9). Correlation between surgical and MRI findings showed good inter-rater agreement for LUCL and AL tears in both raters. Agreement for RCL tear was poor for rater 1 and fair for rater 2; agreement for UCL tear was fair for rater 1 and poor for rater 2. Intra-operative findings showed ten radial head fractures (RHFs) and ten coronoid fractures (CFs). LUCL tears were found in the four cases of type II RHFs and in 3/4 cases of CFs. Bone injuries and ligament tears were not significantly associated.

CONCLUSION

MRI scan supported surgeons to identify soft tissue injuries and to address the most suitable surgical approach after acute elbow dislocation. Inter-observer agreement for intra-operative findings was high for LCL complex injuries and poor for UCL.

Stabilization of the radial head with the palmaris longus or the gracilis tendon: an anatomical feasibility study

PURPOSE

The proximal radioulnar joint (PRUJ) and the radiocapitellar joint may be destabilized after trauma. Different techniques for stabilization of PRUJ have been proposed, but none of them can stabilize the radiocapitellar joint at the same time. We propose a ligamentoplasty to stabilize the radial head at these two joints by reconstructing the radial head annular ligament and the lateral collateral ulnar ligament (LCUL) with a single graft (palmaris longus or gracilis tendon of the knee).

METHODS

Fifteen cadaveric upper limbs were used to compare the stabilization obtained by performing our ligamentoplasty with the palmaris longus or the gracilis tendon. For each technique, the stabilization obtained was evaluated by measuring the displacement of the radial head in the anterior, lateral and posterior directions when a force of 1 N was applied in maximum supination, neutral rotation and maximum pronation. We also evaluated whether this technique could damage the ulnar nerve or the posterior interosseous nerve by dissecting them and whether it could limit the range of rotation of the forearm.

RESULTS

Our ligamentoplasty enables to restore PRUJ stability equivalent to the intact ligament condition. The palmaris longus was inconstant (13/15) and too short to allow concomitant reconstruction of the LCUL (except in one case). No nerve damage was found during the dissection, and the range of rotation of the forearm was not limited by the ligamentoplasty. We also report a clinical case with an excellent result and without complications.

CONCLUSION

This ligamentoplasty we have described makes it possible to stabilize the radial head with respect to the radial notch of the ulna and with respect to the capitellum of the humerus. The gracilis tendon is more suitable than the palmaris longus because of its constant presence and length. A clinical series is now necessary to better evaluate this technique.