PLAIN FILM RADIOGRAPHIC FINDINGS OF CHRONIC ROTATOR CUFF TEAR

Case History

This 65 year old male patient who fell 10 to 12 feet onto his left shoulder six months ago and his shoulder has been hurting ever since. He has difficulty sleeping on his shoulder and has pain on abduction of the shoulder.

Technical Comments

When radiographing the shoulder, a minimum of three views should be obtained: internal rotation, external rotation, and baby arm (abduction view). It is vital that the upper lung fields to include the lung apex be visualized to rule out any possibility of a Pancoast tumor or reinfection apical tuberculosis.

This patient has advanced acromioclavicular joint arthrosis with joint space narrowing and osteophyte formation crossing the joint space. The glenohumeral articulation is normal. Note that the subacromial space is severely compromised with the humeral head almost obliterating the subacromial space. This is best seen on the external rotation view since you can observe on the internal rotation view the subacromial space does not look anywhere nearly as greatly compromised.

Radiographic Findings

This patient’s plain film radiographic findings support the diagnosis of a complete chronic rotator cuff tear with retraction of the distal attachment of the rotator cuff. The unopposed action of the deltoid muscle will force the humeral head to glide cephalically and severely narrow the subacromial space. I suspect this rotator cuff tear has been present a long period of time and on MRI you would see fatty infiltration in the cuff muscles representing disuse atrophy. The normal measurements for the acromial humeral joint space is on an average of 9 mm, the minimum measuring 7 mm and the maximum 11 mm. A measurement less than 7 mm is indicative of a rotator cuff tear. A measurement greater than 11 mm may indicate posttraumatic subluxation, dislocation, joint effusion, stroke, or brachial plexus lesions (drooping shoulder).

Reference Yochum & Rowe, Essentials of Skeletal Radiology, Chapter 2 Measurements of Skeletal Radiology, Lippincott, Williams and Wilkins, 2005.

UTERINE FIBROIDS – A BIZARRE CALCIFIED MASS

Case History

This 63 year old female patient presents with history of lower back pain.

Radiographic Findings

Note the three calcific densities present within the pelvic basin. The round, cystic calcified mass has a very dense peripheral margin and a radiolucent center. This is one form or type of uterine fibroid.

The remaining two large irregular calcifications represent a different pattern of calcification found in benign uterine fibroids.

Uterine fibroids (leiomyomas) represent the most common tumor of women. Twenty-five percent (25%) of women will develop these. These tumors are composed of smooth muscle bundles. The most common site in the uterus is the fundus and corpus. Less than three percent (3%) occur in the cervix. Seventy-five percent (75%) are symptomatic. Vaginal bleeding is the most common symptom. Malignant degeneration to a leiomyosarcoma occurs in less than one percent (1%) of cases, Only ten percent (10%) will calcify and can be seen on an x-ray.

There are three patterns of calcifications:

1) Densely packed flocculent.

2) Non-confluent flocculent.

3) Circumferential-Cystic.

The circumferential-Cystic and densely packed flocculent presentation is noted in this case study.

Reference - Yochum Tr, Yochum and Rowe, LJ, Essentials of Skeletal Radiology, Masqueraders of Musculoskeletal Disease, Chapter 18 Lippincott, Williams and Wilkin s, 2005.

A FOOSH Injury – Fell on an Outstretched Hand

Case History

This 40 year old male patient fell on an outstretched hand while working in a factory years ago.

Fracture of the left scaphoid (navicular)

The margins of the fracture demonstrate a very sclerotic surface. This is indicative of nonunion from a previous fracture. The scaphoid is the most common fractured carpal bone. The usual age of occurrence is between 15 and 40 years. Scaphoid fractures are very rare in children. The mechanism of injury is complex, but it essentially consists of various degrees of hyperextension and radial flexion such as falling on an outstretched hand (FOOSH). These fractures are frequently overlooked and exhibit a significant incidence of complications. The scaphoid is the most common site for occult fracture in the entire human skeleton.

The scaphoid is divided into three regions; 1) the distal pole; 2) the waist; 3) the proximal pole. Approximately 70% of the fractures involve the waist, 20% the proximal pole and 10% the distal pole. Ulnar deviation projections of the hand may help in laying out the actual waist of the scaphoid. If no fracture is seen initially yet the clinical picture is suspicious then precautionary immobilization should be applied and the wrist re-x-rayed in 7 to 10 days. A fracture, if present, will be visible by 20 days post-injury.

A useful soft tissue sign of a subtle scaphoid fracture can be found in alterations to the adjacent scaphoid fat stripe. The normal fat stripe (“navicular stripe”) is a linear collection of fat between the radial collateral ligament and the tendon sheaths of the extensor pollicus brevis and the abductor pollicus longus. In almost 90% of the fractures involving the radial compartment of the wrist the fat stripe will be displaced laterally or totally obliterated. Healing occurs without periosteal callus, the fracture line just gradually disappearing.

Complications: Avascular necrosis, nonunion, carpal instability, and radiocarpal degeneration

Avascular necrosis is encountered in 15% of scaphoid fractures. The scaphoid is anatomically predisposed to avascular necrosis following fracture due to the pattern of the nutrient blood supply. The scaphoid receives a dual blood supply. A small artery enters and perfuses the distal pole and tuberosity. A larger vessel, with an entry site that may be proximal or distal to the scaphoid waist, is responsible for perfusing the remaining areas of the bone. In the development of complicating avascular necrosis, the position of the fracture relative to the principal artery is the most crucial factor. If the fracture is distal to the major vessel, then avascular necrosis is unlikely, if proximal then the probability for avascular necrosis increases significantly. In general, the more proximal this fracture line the greater the probability for avascular necrosis.

Radiological signs of avascular necrosis include increased density and fragmentation. The fracture line will appear wider and is often cystic in appearance. All of the signs will take a variable time after the fracture incident to appear, ranging from months to years. Nonunion occurs in approximately 30% of fractures involving the waist of the scaphoid.