MRI of the reconstructed ulnar collateral ligament

OBJECTIVE: We are often asked to evaluate the postoperative elbow using MRI. In this article, we present both the normal appearance of the reconstructed ulnar collateral ligament (UCL) and a spectrum of UCL graft abnormalities at MR arthrography. CONCLUSION: The UCL is the primary medial stabilizer of the elbow during flexion and is susceptible to injury, particularly in overhead throwing athletes. In the setting of UCL injury, ligament reconstruction is the principal surgical procedure available to restore stability and function and to relieve pain with activity. We have found MR arthrography useful in assessing the reconstructed UCL.     

Avulsion fracture of the medial humerus epicondyle in young wrestlers

We report 2 cases of an avulsion fracture of the medial humerus epicondyle in teenage wrestlers. Two youngsters (13 and 14 years of age) who both competed in the Danish national championship in wrestling avulsed their medial humerus epicondyle. Both were operated on, and the medial humerus epicondyle was reinserted and fixed. The postoperative results were good, as both patients achieved a normal range of motion. To prevent injuries, we recommended that children who begin to wrestle be taught correct falling techniques. Open reduction and internal fixation of the avulsed medial humerus epicondyle is mandatory to guarantee a good final result without permanent disability, and the early and correct diagnosis k therefore of importance.     

Anterior bundle of ulnar collateral ligament: evaluation of anatomic relationships by using MR imaging, MR arthrography, and gross anatomic and histologic analysis

PURPOSE: To evaluate the gross and microscopic anatomy and the magnetic resonance (MR) imaging and MR arthrographic appearance of the anterior bundle of the ulnar collateral ligament (UCL) of the elbow. MATERIALS AND METHODS: The origin and insertion of the anterior bundle of the UCL, the bundle's relationship to the overlying flexor tendons, and the presence of a layered configuration were assessed through inspection and dissection of an elbow specimen. T1-weighted spin-echo MR imaging and MR arthrography in standard imaging planes and a coronal oblique plane were performed in eight other elbow specimens. Additional MR arthrography was performed in four specimens by using the coronal plane with the elbow in 20 degrees of flexion. The specimens were then cut in planes corresponding to those of the MR images. Histologic analysis of two specimens was performed. RESULTS: The anterior bundle of the UCL appeared as a low-signal-intensity structure on T1-weighted spin-echo MR and MR arthrographic images. It consisted of a uniform layer of parallel collagen fibers attaching proximally to the base of the medial epicondyle of the humerus and distally to the medial aspect of the coronoid process of the ulna (sublime tubercle). A layer of synovium separated the anterior bundle from the more superficial tendon of the flexor digitorum superficialis muscle. MR imaging-anatomic comparison in four (50%) specimens revealed separation between the anterior bundle of the UCL and the sublime tubercle. Results of histologic analysis of two of these specimens confirmed insertion of the anterior bundle of the UCL 3 and 4 mm distal to the articular margin. Ligamentous degeneration was detected in only one of these specimens. CONCLUSION: There is variability in the distal insertion of the anterior bundle, and this suggests that caution should be exercised in the diagnosis of its partial detachment from the sublime tubercle of the ulna.     

Case report 280

A fracture involving the trochlear ossification center as well as the medial epicondyle is a more serious injury than simple avulsion of the medial epicondyle. This diagnosis may be difficult in young children before the secondary centers are ossified. Radiographic clues to this injury in a young child are localized soft tissue swelling over the medial aspect of the elbow accompanied by a metaphyseal flake and/or a positive fat pad sign. In the older child, separation of the ossified medial epicondyle with a positive fat pad sign suggests a more complex injury.     

Immature skeletal lesions of the elbow

Excessive repetitive loading of the elbow may produce a myriad of elbow complaints in the adolescent athlete. Osteochondrosis, stress apophysitis of the medial epicondyle, displaced fracture of the medial epicondyle, and osteochondritis desiccans (OCD) of the capitellum and radial head are unique to the skeletally immature elbow and differ from the adult athlete.     

运动员肘关节尺侧肌肉韧带断裂与肘内侧不稳(附33例分析)

文章指出,运动员肘尺侧肌肉韧带装置断裂伤,若急性期内处理不当,可致肘关节尺侧不稳而发生肘习惯性外翻脱臼。作者介绍了治疗习惯性外翻脱臼的手术方法效果较好。     

Ulnar collateral ligament injury in baseball pitchers: MR imaging evaluation.

The ulnar collateral ligament (UCL) provides stability to the medial aspect of the elbow during valgus stress. Trauma to this ligament may result from repetitive forceful throwing. Diagnosis of UCL injury has been based on clinical findings of medial joint pain and valgus instability, as direct imaging of this structure has not been available. Eleven baseball pitchers with clinical evidence of UCL injury were evaluated with magnetic resonance (MR) imaging. Surgical correlation was obtained in six patients, four of whom underwent UCL reconstruction. MR imaging findings in UCL injury included laxity, irregularity, poor definition, and increased signal intensity within and adjacent to the UCL. These findings reflect the presence of hemorrhage and/or edema within the UCL due to repeated microtears, which eventually lead to weakening and possible disruption of the UCL. Optimization of spatial resolution, signal-to-noise ratio, and other technical factors is critical for evaluation of the UCL due to its small size. MR imaging is useful in documenting the presence and severity of injury to the UCL and in distinguishing this entity from other causes of elbow pain.     

肱骨内上髁分离骨骺的复位再愈合对肱骨远端形态的影响

对经切开复位缝合固定或双克氏针内固定的肱骨内上髁骨骺分离患者进行随访时，随机拍摄了１６人的双肘对比Ｘ线正位片。对１６例患者的双肘Ｘ线正位片进行测量分析表明，分离骨骺被复位后再愈合对肱骨远端形态可产生以下影响：①内外上髁间距增大Ｐ＜０．００１）；②肱骨滑车下关节面连线和肱骨纵轴的内下象限夹角变小（ｐ＜０．００１）；③内上髁高度下降（ｐ＜０．００５）；④内上髁与肱骨滑车内侧端相交处出现尺神经切迹；⑤肘携物角有增大趋势。本文还对这些变化的临床意义及机制进行了探讨。     

The medial collateral ligament of the elbow is not isometric: an in vitro biomechanical study

BACKGROUND: The anterior bundle of the medial collateral ligament (AMCL) of the elbow has been shown to be the most important valgus stabilizer of the elbow. However, the isometry of this band has not been quantified. HYPOTHESIS: Isometric fibers exist within the AMCL, and these fibers are located within its central region. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve cadaveric elbow specimens were mounted in a testing apparatus in a valgus gravity-loaded orientation. Passive supinated flexion was performed and the motion recorded using an electromagnetic tracking device. Hundreds of attachment points for the AMCL of the elbow were recorded on the medial epicondyle and ulna. The overall change in length between each point on the ulna to every humeral point, throughout the arc of motion, was quantified (DeltaL = Lmax - Lmin). The locations of the smallest DeltaL values were determined relative to the attachment site of the AMCL on the medial epicondyle. RESULTS: True isometry was not found throughout the arc of flexion. The smallest DeltaL values averaged 2.8 +/- 1.2 mm (range: 0.7 mm to 5.2 mm). Isometric fibers do not exist within the AMCL; however, "nearly" isometric areas are located on the lateral aspect of the attachment site of the AMCL on the medial epicondyle, near the anatomic axis of rotation. CONCLUSIONS: We postulate that these nearly isometric areas would be the most ideal location for graft attachment during reconstruction of the AMCL.     

Media perceptions of Tommy John surgery

Objectives. The prevalence of medial ulnar collateral ligament (UCL) reconstruction is increasing in professional athletes and the delivery of baseball news by the media exerts a powerful influence on public opinion of the injury and surgery. The purpose of this investigation was to examine the media’s perception regarding the causes of UCL injury as well as the indications, risks, benefits, and rehabilitation related to UCL reconstruction. Study design. Cross-sectional survey study, Level 3. Methods. This study utilized an online thirty-question survey designed to assess an individual’s perception of UCL reconstruction with regard to risk factors for injury, indications, benefits, surgical details, and rehabilitation. Eligible study participants were members of the media including print, internet, radio and/or television directly involved in the coverage of Major League Baseball (MLB). Results. A total of 516 members of the media with a mean age of 43.6 years completed the survey. In nearly half (47.8%), professional baseball represented 76–100% of their total sports coverage responsibility. Indications: although the majority answered correctly, 45% did not know if an athlete needed an elbow injury as a prerequisite for UCL reconstruction and 25% believed the primary indication was performance enhancement. As percentage of baseball coverage increased, media members were less likely to believe that an elbow injury was not required (p = 0.038). Benefits: eighty percent recognized that pitching speed is typically reduced following surgery, but the remaining 20% felt that velocities actually increased compared with pre-injury velocities. Return to play: fifty-two percent overestimated the ability of pitchers to return to back to professional baseball and 51.2% believed return would occur in 12 or less months. Estimates were higher in those of older age (p = 0.032) and increased percentage of baseball coverage (p < 0.001). Overuse injuries: less than half (48.4%) believed the use of pitch counts to be important in the prevention of UCL injury and 33.2% felt that throwing injuries were not preventable in adolescent baseball. Conclusion. Common misconceptions exist regarding UCL reconstruction within the professional baseball media. Efforts for physicians to educate the media on the risks of overuse throwing injuries with emphasis on accurate indications, outcomes, and recovery of Tommy John Surgery are encouraged.     

Sonography of injury of the ulnar collateral ligament of the elbow—initial experience

Objective The purpose of this study is to describe the sonographic appearance of injuries of the ulnar collateral ligament (UCL) of the elbow.Design and patients Eight non-professional male baseball pitchers, ages 13–35 years, with medial elbow pain and clinical suspicion of ulnar collateral ligament injury, were referred for imaging. All eight underwent sonography of the affected and contralateral asymptomatic elbow, and six also underwent MR imaging. Neither valgus stress nor power Doppler was used during the sonographic examinations. Time from onset of symptoms to imaging was 1.5 weeks to 6 months. Three patients had surgical confirmation of their injuries, with time from imaging to surgery of 2 days to 9 months.Results In four patients, the UCL was ruptured, manifest sonographically in three cases as discontinuity of the normally hyperechoic ligament with anechoic fluid in the gap and in one case as non-visualization of the ligament with heterogeneous echogenicity in the expected location of the ligament. Two adolescent patients had avulsions of the UCL from the medial epicondyle, with sonographic demonstration of the avulsed echogenic bony fragment in both cases. One patient had a mild sprain, manifest as mild thickening and decreased echogenicity of the ligament sonographically compared with the contralateral normal elbow, with mild surrounding hypoechoic edema. The eighth patient had a small partial tear of the deep surface of the distal aspect of the ligament, visualized as a hypoechoic focus between the deep surface of the ligament and its ulnar attachment.Conclusion Tears of the ulnar collateral ligament are manifested sonographically as non-visualization of the ligament or alteration of the normal morphology.     

The adductor ratio: a new tool for joint line reconstruction in revision TKA

Purpose

In this study, the value of the adductor tubercle as landmark for joint line reconstruction in revision total knee arthroplasty (TKA) was investigated.

Methods

On 100 calibrated full-leg standing radiographs obtained from healthy volunteers, distances from the medial epicondyle, the lateral epicondyle, the adductor tubercle, the fibular head and the centre of the knee to the joint line were determined.

Results

The average distance to the joint line from the medial epicondyle, the lateral epicondyle, the adductor tubercle and the fibular head was found to be 27.7 mm (SD 3.0), 27.1 mm (SD 2.7), 44.6 mm (SD 4.3) and 15.1 mm (SD 3.7), respectively. The distance from the adductor tubercle (R = 0.82) and the centre of the knee (R = 0.86) to the joint line showed a strong and linear correlation with the femoral width. The medial epicondyle, the lateral epicondyle and the fibular head showed less strong correlations. There was no significant correlation with the limb alignment. The adductor ratio was defined as the distance from adductor tubercle to the joint line divided by the femoral width and was found to be 0.52 (SD 0.027) with only small inter-individual variation. The adductor ratio was the most accurate ratio and reconstructed the joint line within 4 mm of its original level in 92 % of the cases.

Conclusion

The adductor ratio is a reliable and accurate tool for joint line reconstruction in revision TKA. It was found to be more accurate then the use of absolute distances and the epicondylar ratios. This study supports the use of the adductor tubercle for joint line reconstruction in revision TKA.

Level of evidence

II.     

Avulsion fracture of the medial epicondyle caused by arm wrestling.

Fractures occurring in teenagers during arm wrestling usually involve the distal humerus and appear as a fracture of the medial epicondyle. We studied eight male patients, aged 13 to 15 years, with such fractures. All fractures involved the right hand and occurred while the patients were in the final stages of winning a match in a formal competition. Three fractures occurred during an official competition and the other five occurred during a match between friends. One patient suffered from ulnar nerve paresis that eventually recovered spontaneously. All of the patients were immobilized for 10 to 21 days, and progressed gradually to motion of the elbow. At 1-year followup, clinical and functional results were satisfying. Therefore, we recommend conservative management for fractures of the medial epicondyle sustained during arm wrestling.     

News briefs

Elbow fractures are common injuries in active patients. When the fracture is nondisplaced, nonoperative treatment is frequently successful. Because stiffness is a common complication, early mobilization is an important aim of treatment; this may necessitate surgical fixation. This article reviews the diagnosis and treatment of fractures of the distal humerus, lateral epicondyle, medial condyle, lateral condyle, olecranon, coronoid process, radial head, and radial neck, as well as supracondylar fractures and Monteggia's fracture.     

Injuries of the medial epicondylar ossification center of the humerus.

The complex nature of the ossification centers makes elbow injuries in a child or adolescent difficult to evaluate. The medial epicondylar ossification center is involved in a significant proportion. Injuries vary from simple avulsions to wide displacement with entrapment in the elbow. When entrapment occurs, it may be mistaken for the trochlear ossification center and the true nature of the injury overlooked. Radiographic findings are presented. The anteroposterior view was found to be diagnostic in minimal or marked avulsions of the medial epicondyle because of the characteristic inferior displacement. The anteroposterior view may not always be diagnostic in cases of entrapment of the medial epicondyle; the lateral view is usually diagnostic. In elbow dislocation, the presence and position of the medial epicondyle must be ascertained. Comparison and oblique views are often of value.     

A clinical and roentgenographic study of Little League elbow

BACKGROUND: Comparisons of medial elbow injury rate and the incidence of clinical and radiographic findings among Little League baseball players have not been documented. HYPOTHESIS: Injury rate and clinical and radiographic findings in Little Leaguers of different positions may be similar. STUDY DESIGN: Survey and retrospective review. METHODS: Altogether, 343 Little Leaguers (120 pitchers, 40 catchers, and 183 fielders) participated in the study. The survey (including age, playing position, playing experience, and symptoms), clinical examination, and roentgenogram of both elbows were obtained for analysis using Pearson's chi-square test. RESULTS: Clinically, 58% of the pitchers presented with soreness compared to 63% in catchers and 47% in fielders. Radiographic examination revealed hypertrophy of the medial humeral epicondyle in all pitchers and catchers and 90% of the fielders. Separation of the medial epicondyle was found in 63% of pitchers, 70% of catchers, and 50% of fielders, while fragmentation was found in 19% of pitchers, 40% of catchers, and 15% of fielders. In subjects with separation or fragmentation, 49% and 56% complained of elbow soreness, respectively. CONCLUSION: Similar rates of medial elbow changes in Little Leaguers may imply that the roentgenological changes of the medial epicondyle could be an adaptive yet physiological reaction to the excessive valgus stress of throwing. The higher incidence of medial epicondylar separation and fragmentation in catchers that has not been reported before may be secondary to the increased stress placed on the elbow when throwing from the squatting position.     

MR imaging of ulnar collateral ligament injury in baseball players: value for predicting rehabilitation outcome

Background

To compare the MR findings of the ulnar collateral ligament (UCL) injury in baseball players between rehabilitation and reconstruction surgery.

Materials and methods

Thirty nine baseball players with clinical evidence of a UCL injury based on medial elbow pain and valgus instability were included. All patients received the rehabilitation treatment for more than six weeks. The elbow MR images of 27 patients not responding to rehabilitation treatment were reviewed that consequently had reconstruction surgery; in addition to 12 patients with improved symptoms with only rehabilitation treatment. The MR imaging was compared between the two treatment groups using the Pearson's chi-square test, and linear-by-linear association for the following features: the degree, signal intensity and site of the UCL injury on fat suppressed T2-weighted images.

Results

High-grade partial tears and complete tears were more commonly seen in the group that had surgery (14 out of 27 patients, 52%; 8 out of 27 patients, 30%), and low-grade partial tears and intact continuity were more common in the group that had rehabilitation only (5 out of 12 patients, 42%; 5 out of 12 patients, 42%) (p = 0.001). The injured UCL showed a fluid-like bright high or intermediate high signal intensity in the group that had surgery more frequently (14 out of 27 patients, 52%; 12 out of 27 patients, 44%), and intermediate high or low signal intensity was more frequent in the rehabilitation group (7 out of 12 patients, 58%; 3 out of 12 patients, 25%) (p = 0.013). The UCL injury at the origin site was most commonly seen in both groups (23 out of 27 patients, 85%; 11 out of 12 patients, 92%, respectively) (p = 0.496).

Conclusion

Preoperative MR imaging is useful for predicting the rehabilitation outcome of UCL injuries in baseball players.     

The adductor tubercle: a reliable landmark for analysing the level of the femorotibial joint line

Purpose

The ratio of femoral width and distance from medial epicondyle to joint line helps estimate the femoral joint line position from femoral width. The approximately radial position of the medial epicondyle on femoral condyle spheres is probably responsible for this relationship, The adductor tubercle approximately lies diametrically opposite to the joint line on condylar sphere. Then, a linear correlation could also exist between the femoral width and distance of adductor tubercle to joint line and is the purpose of the current study.

Methods

Femoral width, along with the distance to joint line from the medial epicondyle, the adductor tubercle and fibular pole, was measured on 110 standard antero-posterior knee radiographs. Correlation between femoral width and these measurements was evaluated. The individual ratio of FW with adductor tubercle joint line, medial epicondyle joint line and fibula joint line was calculated using linear regression analysis. Intra-observer and inter-observer reliability was assessed.

Results

Linear correlation was found between femoral width and distance of adductor tubercle to joint line (r = 0.83). It was more reliable than the correlation between femoral width and distance from medial epicondyle to joint line (r = 0.52). Inter-observer repeatability was better for distance from adductor tubercle to joint line than for distance from medial epicondyle to joint line.

Conclusions

We conclude that adductor tubercle can be used as a morphologic landmark to determine the knee joint line position, because a linear correlation between femoral width and distance from the adductor tubercle to the joint line was found.

Level of evidence

Case series, Level IV.     

The sartorial nerve: its relationship to the medial aspect of the knee

When using the medial approach to the knee, as in repair of medial compartment structures, knowledge of the location of the sartorial nerve is important in order to avoid postoperative distress caused by division of this nerve. We studied the locations of the sartorial nerve in 23 cadavers, with particular reference to the relationship with the pes anserinus and the nerve's distance from the medial femoral epicondyle. The average distance between the sartorial nerve at its emergence and the central point of the medial femoral epicondyle was 34.02 mm, with a range of 20.7 to 49.8 mm on the right lower limb, and 33.27 mm, with a range of 20.0 to 49.2 mm, on the left lower limb.     

Evolution of the treatment options of ulnar collateral ligament injuries of the elbow

Ulnar collateral ligament (UCL) insufficiency is potentially a career threatening, or even a career ending, injury, particularly in overhead throwing athletes. The evolution of treating modalities provides afflicted athletes with the opportunity to avoid premature retirement. There have been several clinical and basic science research efforts which have investigated the pathophysiology of UCL disruption, the biomechanics specific to overhead throwing, and the various types of treatment modalities. UCL reconstruction is currently the most commonly performed surgical treatment option. An in depth analysis of the present treatment options, both non-operative and operative, as well as their respective results and biomechanical evaluation, is lacking in the literature to date. This article provides a comprehensive current review and comparative analysis of these modalities. Over the last 30 years there has been an evolution of the original UCL reconstruction. Yet, despite the variability in modifications, such as the docking technique, interference screw fixation, and use of suture anchors, the unifying concepts of UCL reconstruction are that decreased dissection of the flexor-pronator mass and decreased handling of the ulnar nerve leads to improved outcomes.