Carrying Angle

Carrying Angle controversies

Dr S L Yadav, MDDepartment of Physical Medicine & Rehabilitation

AIIMS, New Delhi- 110029

Introduction

• Acts as a lever arm when positioning the hand• Functions as a fulcrum for forearm lever• In patients using crutches, it functions as a

weight bearing joint. • During throwing, there is transfer of energy

between the shoulder and elbow• It is crucial for activities of daily living

Carrying Angle• Long axis of the humerus & ulna• Average angle: Females 13.6/ Males 6.7• Length of FA and carrying angle has significant relation among

girls; the elbow carrying angle higher who have short FA/ulna• Dominant hand > Non-dominant hand (ligamentous laxity at

the medial elbow or asymmetrical bone growth)• Unilateral aseptic necrosis of humeral trochlea lead to loss of

carrying angle• Bony remodeling to adapt stress among professional base ball

pitchers

DefinitionThe carrying angle has been defined as the angle between:• the longitudinal axes of the arm and forearm (Amis and Miller

1982), see figure 1(a);• the longitudinal axes of the humerus and the ulna, determined

on X-rays (Keats et al. 1966, Steindler 1973); the corresponding anatomical reference lines are considered in figure 1(b);

• the longitudinal axes of the humerus and the ulna determined on X-rays by means of the construction of two mid-points at both the distal humerus and the proximal ulna (Beals 1976); the corresponding anatomical reference lines are considered in figure 1(c).

Measurement of Carrying Angle

Importance

• The carrying angle values increases progressively from childhood until 16 years when stabilization noticed.

• Useful in management in elbow displacement and fractures

• Epicondylar disease• Surgical planning for elbow reconstruction• Walking, swinging and carrying objects

Abnormality of carrying Angle

Any variation of the angle that is more than 15°is known as cubitus valgus and less than 5°are called cubitus varus.

Physiological conditions

The parameter varies according toAgeGender, Hyperextension of the elbow, Dominant upper limb, Anthropometric characteristics such as height and

intertrochanteric distance and can be measured by simple clinical and radiographic techniques.

Factors influencing carrying angle

• Elbow musculature/ligaments• Forearm rotation • Elbow flexion (changes when elbow flexed)• Anatomical factors:

– Medial flange of trochlea 6mm below the lateral flange– Superior articular surface of the coronoid process of the ulna

is placed obliquely to the long axis of the ulna

Factors……• In most cases, the increased carrying angle is due to

muscle weakness or ligament injury, inefficient alignment/ hypo-mobility of the bones or soft tissue tightness lead to abnormal biomechanics

• The patient had an increased carrying angle of 20 degree and pain with throwing; after 6 weeks of treatment (joint/ soft tissue mobilization and exercise program) able to throw and play continuously for more than 20 innings without pain and his carrying angle has decreased to 12 degrees!

Abnormal carrying angle of elbow in children

• Cardiofaciocutaneous syndrome• Cohen syndrome• Condylar fracture at the elbow• Noonan syndrome• Turner syndrome: Cubitus valgus is caused by

developmental abnormalities in the trochlea of the humerus. Alteration in the shape of the trochlea changes the angle of articulation with the ulna, resulting in increased elbow angulation.

Elbow Observation• Anatomical – Carrying Angle– Cubitum Varum– Cubitum Valgum– Cubitum Recurvatum

Anatomy Overview

Capsuloligamentous Complex

• Medial collateral ligament• Lateral collateral ligament

Humeroulnar Joint

• A uniaxial hinge joint formed between the trochlear notch of the proximal ulna and the spool-shaped trochlea of the humerus

• The angulation of this joint forms the “carrying angle”

• The carrying angle is approximately 11-14° in males and 13-16° in females

Medial (Ulnar) Collateral Ligament • The fan-shaped MCL is

functionally the most important ligament in the elbow for providing stability against valgus stress, particularly in the range of 20-130° of flexion and extension

• There are three distinct components of the MCL:– Anterior bundle– Transverse bundle– Posterior bundle

• Resists valgus stress • Limits extension• Taut throughout arch of

motion– Anterior fibers most taut in

extension– Posterior bundle is taut in

flexion• Transverse fibers provide

valgus stability and help with joint approximation

Medial (Ulnar) Collateral Ligament

• Anterior bundle– Anterior band

• The strongest and stiffest of the elbow collateral ligaments

• Primarily stabilizes the elbow against valgus stress in the ranges of 20-120° of flexion, and becomes a secondary restraint with further flexion


• Anterior bundle– The posterior band

• Taut beyond 55° of elbow flexion

• A secondary restraint to valgus stress at lesser degrees of flexion

• An equal co-restraint with the anterior band at terminal elbow flexion

• A primary restraint to passive elbow extension


• The transverse bundle– Also known as Cooper’s

ligament– Fibers both originate and

insert on the ulna and therefore have little role in elbow stability


• Posterior bundle– Appears to be a

thickening of the posterior elbow capsule

– Provides only secondary restraint to valgus stress at flexion beyond 90°.

Electromagnetic tracking system

Clinical Protractor Goniometer and with an Electromagnetic tracking system.

Why to measure

• Knowledge of the measurement of the elbow carrying angle and of its variations is important when evaluating traumatic elbow injuries and other elbow disorders that require reconstruction or arthroplasties (surface and semiconstrained)

• This parameter shows a gradual increase from childhood up to the age of 16 years when the skeletal maturity is attained and demonstrated by its stabilization.

Methods• In vitro using mechanical instrumentations,

Hinged boards, or Goniometers rigidly attached to the humerus; Kinematics or geometrical computations; or Radiographs, thus obtaining results not always in agreement. The main reasons for this are differences in the definition of the angle and variations

• Van Roy et al adopted a protractor goniometer and an electromagnetic tracking device to estimate the carrying angle in full extension and also during flexion of the elbow joint.

Over-use risk factors

• Heavy training loads• Early sport specific training• Year-round throwing• Participation in multiple sports• Training errors-unqualified coaching & supervisory

practices• Muscle tendon strength & extensibility deficiencies• Faulty equipments

What about the ulnar collateral ligament?

• The Throwing or Overhead motion

Throwing Motion

• Early cocking– Abduction/ER - Supraspinatus very active

• Late Cocking– Anterior shld. Stretched/medial elbow valgus– Scapula must be stable– Valgus stress on elbow

• Acceleration– Stable scapula/Large muscle groups to IR– Valgus stress on elbow

• Deceleration - ECCENTRIC– Teres Minor/Infraspinatus espec. active to slow down– Biceps Brachii to slow elbow extension

• Follow-Through– Scapula protracts(abducts) - Serratus anterior– LHB tendon stabilizes

Acceleration:

Extension occurs at a rate of up to 25º per second and continues to 20º of flexion. Forearm lags behind the upper arm and generates valgus stress (> 60 Nm), The valgus force can overcome the tensile strength of the UCL and cause either chronic microscopic tears or acute rupture.

Tensile stress

Ulnar (Medial) Collateral• At 90º of flexion, it provides 55% of the resistance to

valgus stress at the elbow.– UCL is composed of 3 bands: anterior, posterior, and

transverse • Etiology– Injured as the result of a valgus force from repetitive

trauma– Can also result in ulnar nerve inflammation, or wrist flexor

tendinitis; overuse flexor/pronator strain, ligamentous sprains; elbow flexion contractures or increased instability

TCI v/s Bauman’s Angle• Trochaleocapitellar Index (TCI): The ratio between the smaller

trochanter and larger capitelar angles of the measured elbow, not influenced by radiographic technique (elbow position/rotation of the distal fragement) – Post SC # reduction, determines the adequacy of reduction– Coronal plane angulation prevention indicates accurate reduction of #

• Bauman’s Angle: intersection of a line drawn the humeral axis and a line drawn along the growth plate of the capitulum of the elbow

TCI > Bauman’s angle

Study Of Carrying Angle And Its Correlation With Various Parameters

Dr. Srushti Ruparelia, Dr. Shailesh Patel, Dr. Ankur Zalawadia, Dr. Shaival Shah,Dr. S. V. Patel. NJIRM 2010; Vol. 1(3). July-Sept. pg 28-32.

There is no difference in the carrying angle in male &female up to the puberty. But in the female, it is increased after puberty.

• The result of the study showed that the average carrying angle was 13.6 degrees for females and 6.7 degrees for males. The length of the forearm and the carrying angle showed significant relation.

• Conclusion: The result of the study could be useful in the management of elbow displacement, fractures, epicondylar disease and surgical planning for elbow reconstruction.

With the elbow extended, the carrying angle of the elbow should be reviewed, and clinical comparison as well as radiograph comparison can be performed to assure an adequate reduction.

Investigations - Ultrasound• Controversial

• Medial elbow pain was associated with widening of the medial joint space (p < 0.05) and with the presence of attenuation of the ulnar collateral ligament (p < 0.01)

• Absolute difference 2.7mm vs. 1.6mm

Ultrasonographic assessment of the ulnar collateral ligament and medial elbow laxity in college baseball players. Sasaki J, Takahara M,Ogino T, Kashiwa H,

Ishigaki D, Kanauchi Y. J Bone Joint Surg Am. 2002 Apr;84-A(4):525-31

EVOLUTION OF THE CARRYING ANGLE OF THE ELBOW: A CLINICAL AND

RADIOGRAPHIC STUDYTerra BB, Silva BCM, Carvalho HBF, Dobashi ET, Pinto JA, Ishida A. Acta Ortop

Bras. [online]. 2011;19(2):79-82.

CONCLUSIONThis parameter shows a gradual increase from childhood up to the age of 16 years when the skeletal maturity is attained and demonstrated by its stabilization. There was no significant statistical difference between the clinical and radiographic measurements.

An evaluation of the carrying angle of the elbow joint in adolescents

Rajesh B*, Reshma VR, Jaene RC, Somasekhar IT, Vaithilingam A

Int J Med Biomed Res 2013;2(3):221 -225

Conclusion: The result of the study could be useful in the management of elbow displacement, fractures, epicondylar disease and surgical planning for elbow reconstruction

The Carrying Angle in Sex Chromosome Anomalies

Fred A. Baughman Jr., MD; James V. Higgins, PhD; Thomas G. Wadsworth, FRCS, FACS; Michael J. Demaray, MD. JAMA. 1974;230(5):718-720.

Conclusions: The carrying angle is said to be greater in the XO phenotype than in XX and greater in XX than in XY.

The actions of bowlers with a large “carrying angle” or a hypermobile elbow often look suspicious even though they are legal

The study of predictor’s anthropometric parameters of upper limb with elbow carrying angle in athletesDaneshmandi Hassan, Shahrokhi Hossein, Pegah Rahmani, Nazary Sharif Hossein. Journal of Romanian Sports Medicine Society.Medicina Sportiva (2014), vol. X, no 4, 2447-2451.

ConclusionsThe results of regression showed that among the variables shoulder-elbow length, elbow-wrist length and arm span, shoulder- elbow length was the best predictors of carrying angle. According to results of this study athletes who have greater forearm are more exposure carrying angle changes and require special medical care in upper extremities to maintain normal elbow alignment.

The role of the elbow musculature, forearm rotation, and elbow flexion in elbow stability: An in vitro studyKenneth Seiber, MD, Ranjan Gupta, MD, Michelle H. McGarry, MS, Marc R. Safran, MD, Thay Q Lee, PhD. J Shoulder Elbow Surg (2009) 18, 260-268

ConclusionsThe medial elbow musculature mostly affects elbow stability with the arm in supination and the lateral musculature in pronation, where the passive tension in the respective muscles is increased. Furthermore, the medial elbow musculature provided stability to the elbow when the forearm was supinated even with a deficient anterior bundle of the UCL, emphasizing its role as a secondary stabilizer.

A protocol for clinical evaluation of the carrying angle of the elbow by anatomic landmarks

Maria Luisa Zampagni, MSc, PhD, Daniela Casino, MSc, Sandra Martelli, MSc, Andrea Visani, MD, and Maurilio Marcacci, MD, Bologna, Italy. J Shoulder Elbow Surg 2008;17:106-112.

In conclusion, this study shows that the carrying angle evaluation by the FaroArm and the Cardan algorithm provides more reliable results than other methods. The setup is comfortable for the subject, and acquisition is fast and takes about a minute, including software elaboration of the result.

Arthro-kinematics of the elbow: study of the carrying angle

P. VAN ROY, J. P. BAEYENS, D. FAUVART, R. LANSSIERS and J. P. CLARIJS. Ergonomics, Vol. 48, Nos. 11 – 14, 15 September – 15 November 2005, 1645–1656 .

The mean carrying angles at 0, 30, 60, 90 and 120 degree of flexion revealed larger standard deviations in the male group than in the female group.

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Carrying Angle