Injuries of the Throwing Elbow

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- See:
      - Elbow Arthroscopy
      - Radiology of Pediatric Elbow
      - Throwing Injuries of the Shoulder

- Discussion:
    - phases of throwing:
          - windup
          - early cocking
          - late cocking
                - wrist begins to cock in preparation for the throw and final energy release.
                - begins when the pitcher's front foot touches the ground and terminates with maximal humeral external rotation;
                - elbow remains flexed between 60 deg to 75 deg
                - ECRB and ECRL show relatively high levels of activity;
                - significant valgus force at elbow occurs at this stage (maximal MCL stress);
          - acceleration
                - starts with maximal humeral external rotation and ends with ball release;
                - elbow experiences a rapid combination of valgus and extension;
                - significant valgus force at elbow occurs at this stage (maximal MCL stress);
                - maximal activity in pronator teres, FCR and FCU;
                - extended wrist flexes at this stage;
          - deceleration
                - shows the largest amount of muscle activity by the elbow flexors
          - follow through

- Diff Dx:
    - osteochondritis dissecans of the capitellum:
    - osteochondrosis of the medial epicondyle:
    - posteromedial olecranon osteophytosis:
          - chronic repitative throwing in the young adolescent w/ lax joints, can cause impingement of the medial tip of olecraon on posteromedial tip of the olecranon fossa
                 during the terminal swing phase of throwing;
          - results in posterior ulnohumeral impingement, restriction range of motion (extension), ulnar nerve compression neuritis, and loose body formation;
          - patient may show tenderness over the posteromedial aspect of the olecranon and a mild flexion contracture;
                 - posteromedial tenderness may be exentuated as the elbow is brought into extension;
          - either open or endoscopic osteophyte removal is curative;
          - references:
                 - Partial Posteromedial Olecranon Resection: A Kinematic Study.
                 - Medial Collateral Ligament Strain with Partial Posteromedial Olecranon Resection.
    - radial head deformation
    - radiocapitellar menisciod lesions
    - medial tension overload:
          - muscular (flexor pronator group)
          - strain (minor tears)
          - MCL strain or rupture:
                 - ulnar traction spurs
                 - calcium deposits
                 - medial ligament instability
          - fascial compartment syndrome
          - medial epicondylitis
          - medial epicondyle apophysitis (little leaguer's elbow);
                 - look for irregular ossification and overgrowth of the medial epicondylar apophysis;
                 - w/ cessation of throwing, tenderness will resolve, and ROM will be restored;
                 - reference:
                       - Little leaguer's elbow. BG Brogdon and NE Crow.  Am J. Roentgenol. Vol 83. 1960. p 671-675.
          - avulsion of the medial epicondyle
    - misc:
          - extension overload
          - triceps muscle strain
          - avulsion fracture tip of olecranon
          - olecranon hypertrophy
          - loose bodies in the olecranon fossa
          - tears of brachialis and anterior capsule
          - fixed flexion contracture;
          - posterolateral instability

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Ulnar nerve entrapment syndrome in baseball players.  W Del Pizzo, et al.  Am J. Sports Med. Vol 5, 1977, 182-185.

Anterior angulation deformity of the radial head. An unusual lesion occurring in juvenile baseball players.

Correctable elbow lesions in professional baseball players. A review of 25 cases.  PA Indelicato et al.  Am. J. Sports Med. Vol 7, 1979, p 72-75.

Medial instability of the elbow in throwing athletes. Treatment by repair or reconstruction of the ulnar collateral ligament.

Olecranon stress fractures in throwers. A report of two cases and a review of the literature.

Traumatic ulnar neuropathy in adolescent baseball pitchers.  RW Godshall, CA Hansen. JBJS 53-A, 1971, 359-361.

Bony Injuries about the Elbow in Young Throwing Athletes.   Andrews, J. Instr. Course Lect. 34: 323-331, 1985.

Throwing injuries of the elbow.   FW Jobe, G Nuber.  Clinical Sports Med. Vol 5, 1986, 621-636.

An EMG analysis of the elbow is normal and injured pitchers with MCL insufficiency.  Glousman RE, Barron J, Jobe FW, et al: Am J Sports Med 20:311-317, 1992

Elbow Problems Associated with Baseball during Childhood and Adolescence.  Pappas, A.  CORR 164:30-41, 1982.

Persistence of the olecranon physis: a cause of "little league elbow."    WD Lowery et al.  J. Shoulder Elbow Surg. Vol 4 (2) 1995. p 143-147.

An electromyographic analysis of the upper extremity in pitching.  DiGiovine NM, Jobe FW, Pink M, et al: J Shoulder Elbow Surg 1:15-25, 1992