Alexandria Radiology » Musculoskeletal

Muscoloskeletal Case 24

anne — Mon, 21 Jun 2010 16:56:09 +0000

The plantaris muscle originates from the lateral aspect of the distal femur and extend inferiorly to attach onto the calcaneum. Plantaris tendon tears are treated conservatively and usually have an excellent prognosis. The tendon is primarily known to the orthopedic sugeon as being useful for grafts.

Musculoskeltal Case 23

anne — Thu, 15 Oct 2009 15:44:07 +0000

Giant cell tumors of the tendon sheath are the second most common tumors of the hand, after the ganglion cyst. There is controversy regarding the underlying nature of this lesion, specifically whether it is a neoplastic or nonneoplastic. They do not always arise from the tendon sheath but may arise from the synovium. They have a predilection for the flexor surfaces of the hand. Clinically, they are usually painless masses. They can occur at any age, but are most commonly diagnosed between ages 30 and 50. They commonly occur in the hands but have been identified in the foot as well. Most lesions were inhomogeneous due to low-signal-intensity areas and enhanced following gadolinium administration.

On plain radiographs, a small number of the lesion (about 20 percent) will show smooth bony erosions.

On MRI, the lesion is typically hypointense to intermediate on T1 WI and inhomogenous mixed to intermediate and/or high signal on T2 WI with internal low signal septations. Intense and homogenous enhancement is seen after contrast administration.

On ultrasound, they typically appear as solid, homogeneous hypoechoic masses with detectable internal vascularity that are associated with the flexor tendons of the fingers.

Treatment is usually with surgicalexcision.

Musculoskeletal Case 22

anne — Wed, 30 Sep 2009 17:04:16 +0000

Osteoid osteoma (OO) is a benign skeletal neoplasm. They account for approximately 10 percent of benign bone tumors. Osteo osteoma occurs most frequently in the second decade. About 80 percent of OO cases are cortical. The rest are intramedullary. The proximal femur is the most common location followed by the tibia, posterior elements of the spine, and the humerus.

The classic radiological appearance is a radiolucent nidus surrounded by a reactive sclerosis in the cortex of the bone usually less than 2 cm in long axis. The tumors may regress spontaneously.

Musculoskeletal Case 21

anne — Tue, 14 Jul 2009 13:16:27 +0000

The majority of os subfibulare are usually asymptomatic. The exact cause of symptoms in patients is unclear. In general, accessory ossicles commonly observed in order of frequency of the lower extremity include: tibiale externum, os trigonum and os peroneum. Accessory bones that are rare in the foot include accessory interphalangeus, os peroneum, anamolous os calcaneum and talus, os trignum and os tibiale extenum. When symptomatic they are most often treated with anti-inflammatory. When the pain is recalcitrant, surgical intervention may be required.

Musculoskeletal Case 20

anne — Tue, 14 Jul 2009 13:14:33 +0000

Small particle disease (SPD) was first recognized by Charney in the 1960s and was initially believed to be related to the cement used to anchor the prostheses. Originally this was called cement disease or aggressive granulomatosus. Small particle disease is a frequent complication in total hip arthroplasty and a frequent reason for revisions. Today it is mostly seen in non-cemented hips as a reaction to small polyethylene wear particle, although any small particles (metal, cement, or polyethylene) can play a role in initiating osteolysis. Micro-particles produced by polyethylene wear in prostheses readily phagocytosed by macrophages but not easily digested which in turn results in production of numerous mediators and cytokines by stimulated macrophages such as prostaglandin E2, IL-1, and osteoclast activating factors that destroy bone and form focal granulomatous lesions composed of multinucleated giant cells and monocytes. Small particle disease can virtually take place with any joint arthroplasty.

Radiographically, the lesions are typically well-defined focal areas of bone resorption that do not conform to the shape of the prosthesis. They can be expansile, resulting in areas of cortical breaks.

Musculoskeletal Case 19

anne — Tue, 14 Jul 2009 13:12:04 +0000

If left untreated leads to high incidence of long term functional disability and chronic pain. Perilunate dislocations more common than lunate dislocations. Most commonly dorsal dislocation. The perilunate dislocation most often results from a backwards fall on an extended wrist disrupting the scaphoid ligaments. The capitate is dorsally located relative to the lunate. The lunate bone maintains its normal relationship with the radius. 75 percent of the cases are accompanied by fractures with the most common being the scaphoid waist, but radial styloid, capitate, and ulnar styloid fractures have been described.

Musculoskeletal Case 18

anne — Tue, 14 Jul 2009 13:09:42 +0000

Lateral hip pain can be a clinically challenging diagnostic problem. Trochanteric bursitis is defined by painful inflammation of the greater trochanter bursa. This may occur in physically active patients or in sedentary individuals. Most often caused by overuse, stress or direct trauma to the joint. Usually unilateral but can be bilateral.

Recently, an expanded spectrum of pathologic abnormalities affecting the soft tissues of the hip has been noted, with such findings including not only trochanteric bursitis but also the so-called rotator cuff tears of the hip. MRI studies for greater trochanteric pain syndrome found tear involving gluteus medius tear and gluteus medius tendonitis, calling into question how many of these patients actually have bursitis. In fact, the coexistence of trochanteric bursitis and abductor tendinopathy has led some authors to suggest that bursitis may in fact be a result of the underlying tendinopathy.

Differential considerations of lateral hip pain includes: AVN, hip arthritis; insufficiency fractures, pseudotrochanteric bursitis, adiposis dolorosa, tensor fasciae femoris syndrome, abductor muscle strain, and a spinal source of pain.

Musculoskeletal Case 17

anne — Tue, 14 Jul 2009 12:57:40 +0000

Osteogenesis imperfecta (OI) is typically classified as one of four types:

OI type I: (tarda) 90% more benign form with normal life expectancy.
- blue sclera
- ligamentous laxity
- dental abnormalities
- deafness
- osseuse abnormality

OI type II: (congenital) 10% Death in utero or neonatal period.

OI type III: Fractures at birth, progressive limb deformity. Normal sclera and healing.

OI type IV: Bone fragility, normal sclera and healing.

Radiographic feature: Bowing deformity, cortical thinning, fractures, wormian bones, vertebral scalloping, severe kyphoscoliosis, acetabular protrusion.

Musculoskeletal Case 16

anne — Tue, 14 Jul 2009 12:49:18 +0000

Accessory soleus muscle is a rare anatomical variant with an 0.7–5.5% incidence manifested by presence of a supernumerary musculature. The anomaly may be unilateral, bilateral, symmetrical or asymmetrical. The proximal origin is typically on the distal posterior aspect of the tibia. Its distal attachment is via a separate tendon on the calcaneus. Patients typically report aching pain after strenuous activity, which has been attributed to close compartment ischemic mechanism since the accessory muscle is invested in a separate fascial sheath with a tenuous blood supply from the posterior tibial artery.

MRI shows soft tissue mass in the posteromedial aspect of the ankle with signal intensity similar to muscle. MRI can show intramuscular edema in cases of muscular strains.

Treatment usually depends on the presence or severity of the symptoms. Asymptomatic patients can be reassured with no active treatment being required. For symptomatic patients, conservative treatment such as orthoses, physical therapy and activity modification may be tried. Surgical approaches include fasciotomy or excision of the muscle.

Musculoskeletal Case 15

anne — Tue, 14 Jul 2009 12:44:56 +0000

The recommendations of the Combined Task Forces of the North American Spine Society, American Society of Spine Radiology, and American Society of Neuroradiology published in 2001:

“Herniated discs may take the form of protrusion or extrusion, based on the shape of the displaced material.

Protrusion is present, if the greatest distance, in any plane, between the edges of the disc material beyond the disc space is less than the distance between the edges of the base in the same plane. The base is defined as the cross-sectional area of disc material at the outer margin of the disc space of origin, where disc material displaced beyond the disc space is continuous with disc material within the disc space. In the cranio-caudal direction, the length of the base cannot exceed, by definition, the height of the intervertebral space.

Extrusion is present when, in at least one plane, any one distance between the edges of the disc material beyond the disc space is greater than the distance between the edges of the base in the same plane, or when no continuity exists between the disc material beyond the disc space and that within the disc space. Extrusion may be further specified as sequestration, if the displaced disc material has lost completely any continuity with the parent disc.

The term migration may be used to signify displacement of disc material away from the site of extrusion, regardless of whether sequestrated or not. Because posteriorly displaced disc material is often constrained by the posterior longitudinal ligament, images may portray a disc displacement as a protrusion on axial sections and an extrusion on sagittal sections, in which cases the displacement should be considered an extrusion. Herniated discs in the cranio-caudal (vertical) direction through a break in the vertebral body end-plate are referred to as intravertebral herniations.

Disc herniations may be further specifically described as contained, if the displaced portion is covered by outer anulus, or uncontained when absent any such covering. Displaced disc tissues may also be described by location, volume, and content.