Jack P. Lawson

The painful accessory navicular

The accessory navicular is usually considered a normal anatomic and roentgenographic variant. The term may refer to two distinct patterns. First, a sesamoid bone may be present within the posterior tibial tendon (Type 1); this is anatomically separate from the navicular. Second, an accessory ossification center may be medial to the navicular (Type 2). During postnatal development this is within a cartilaginous mass that is continuous with the cartilage of the navicular. At skeletal maturity the accessory center usually fuses with the navicular to form a curvilinear bone The Type 2 pattern may be associated with a painful foot, particularly in the athletic adolescent, and should not be arbitrarily dismissed as a roentgenologic variant in the symptomatic patient.The clinical, radiologic, pathologic, and surgical findings in ten cases are reviewed. Roentgenographically the ossicle is triangular or heartshaped. 99mTc MDP imaging may be of value when the significance of the ossicle is uncertain. Even when the roentgenographic variant is bilateral, increased radionuclide activity occurs only on the symptomatic side. Histologic examination of surgically excised specimens reveals inflammatory chondro-osseous changes in the navicular-accessory nacicular synchondrosis compatible with chronic trauma and stress fracture. Nonsurgical treatment with orthotics or cast immobilization produces variable results and resection of the accessory navicular may be the treatment of choice.

Avascular necrosis of bone in Hodgkin's disease patients treated with combined modality therapy.

Avascular necrosis of bone developed in eight patients with advanced Hodgkins disease who had been treated with combined modality therapy and were in complete remission from their disease. A ninth patient not on protocol but treated with the combined modality program also developed avascular necrosis. The cumulative incidence was 10% among long‐term survivors. The etiology is unclear. Prolonged corticosteroid administration has been implicated but usually in much larger doses than the patients in this series received. The possible roles of the other chemotherapeutic agents for Hodgkins disease, and radiation are discussed. Considerable disability resulted for almost all patients. Three of seven patients primarily with avascular necrosis of the femoral heads had bilateral hip replacements with surgery anticipated in four others. The two patients primarily with humeral head involvement have limited use of their arms. This condition must be added to the known possible serious consequences of combination chemotherapy for Hodgkins disease. It is uncertain if the frequency of avascular necrosis is higher in patients treated with both radiation and chemotherapy compared with chemotherapy alone. Further studies are needed from other institutions to clarify the frequency and cause of this problem.

The spectrum of skeletal changes associated with long-term administration of 13-cis-retinoic acid

The roentgenographic changes noted in 13 patients, who had been treated with long-term 13-cis-retinoic acid for inherited scaling disorders, are presented. These patients were aged 13–16 years and had received this therapy for 16–87 months (mean, 58 months). The most pronounced abnormality was osteophyte formation, particularly in the cervical spine. Other changes which were noted included ossification of the anterior longitudinal and atlanto-occipital ligaments, proliferative enthesopathies, diminished bone density, premature fusion of epiphyses, and modeling abnormalities. Six of the 13 patients were asymptomatic and the osseous manifestations of this therapy were identified only by roentgenographic evaluation.

Skeletal Changes Associated with Chronic Isotretinoin and Etretinate Administration

The skeletal changes associated with systemic retinoid therapy reflect the influence of retinoids on differentiating systems. Although skin is usually the intended target, treatment with retinoids often results in abnormalities of ossification and calcification. The effects of retinoids on bone may be profound and include progressive calcification of ligaments and tendon insertions, premature fusion of epiphyses, modeling abnormalities of long bones, and perhaps osteoporosis. Although it has been known since 1933 that vitamin A cause bone abnormalities, the mechanism of this effect has been elusive. Recent work suggests a possible relationship of the retinoids with several cytokines, which results in enhanced maturation of the preosteoclast. The increasing number of significant bone changes, including posterior lumbar vertebral osteophytosis, make skeletal toxicity the principle risk factor of chronic systemic retinoid therapy.

Biomechanics of the Accessory Navicular Synchondrosis

The accessory navicular is commonly considered an asymptomatic variant, but when traumatized, it can become the source of clinical symptoms. The accessory naviculars were divided into Types I, IIa and b, and III based on their appearance and location with relationship to their parent navicular. Only Type IIa and b accessory naviculars have a synchondrosis. The synchondrosis of Type IIa and b can undergo tension, shear, and compression forces causing avulsion or a painful pseudarthrosis to develop.

Case report 174

A 63-year-old man presented with a three-year history o f a slowly growing, painless mass in the right thigh. In the proceeding months , more rapid growth had resulted. He gave a history of being wounded in battle in Germany in 1945 (approximately 35 years previously), incurring a right femoral fracture with retained shrapnel in the soft tissues. Several months later, in England, he underwent a definitive repair with internal fixation and bone grafting. Thereafter, he reported no problems with the leg until the present episode. On physical examination, a large (approximately 10 x 20 cm), firm, movable, non-tender, posterolateral mass in the right thigh was noted. N o sinus tract was observed and the mass was no t pulsatile. The hematological and blood chemical studies were within normal limits. Roentgenograms of the right femur (Fig. 1) and addit ional special studies were obtained (see later). Surgical explorat ion was undertaken.

Pinemoth caterpillar disease

Pinemoth caterpillar disease is a well-recognised disorder which occurs in South-Eastern China and is due to contact with the cocoons or larvae of the pinemoth (Dendrolimus punctatus). Generalised symptoms, which may be noted within two weeks of contact, consist of pyrexia, anorexia, malaise, rigors, headache, or dizziness. Localised abnormalities include dermatologic changes, skin nodules, and arthritis. The arthritis is usually monoarticular and most frequently involves the knee, ankle, and wrist. The radiologic findings consist of periarticular swelling, osteoporosis, erosions, or periosteal reaction in the acute phase and osseous sclerosis, joint deformity, persistant soft tissuc swelling, or premature fusion of ossification centers in the chronic stages.

Not-so-normal variants

In contrast to the widely held view that radiologic normal variants are of no clinical significance, many of the anatomical variants of the skeletal system may, in fact, be responsible for symptoms. Three groups of reputedly normal variants are presented: Group 1 consists of ossicles that, from the onset, may represent the sequelae of chronic repetitious trauma; group 2 is composed of normal variants in which the presence of a congenital synchondrosis may predispose to injury from chronic repetitious trauma; and group 3 consists of ossicles that in a variety of ways predispose to local and premature degenerative changes. These ossicles may be asymptomatic, however, radionuclide bone scanning is crucial in evaluating the significance of the ossicles in the symptomatic patient.In contrast to the widely held view that radiologic normal variants are of no clinical significance, many of the anatomical variants of the skeletal system may, in fact, be responsible for symptoms. Three groups of reputedly normal variants are presented: Group 1 consists of ossicles that, from the onset, may represent the sequelae of chronic repetitious trauma; group 2 is composed of normal variants in which the presence of a congenital synchondrosis may predispose to injury from chronic repetitious trauma; and group 3 consists of ossicles that in a variety of ways predispose to local and premature degenerative changes. These ossicles may be asymptomatic, however, radionuclide bone scanning is crucial in evaluating the significance of the ossicles in the symptomatic patient.

Case report 701

A case of periosteal new bone in a newborn is presented. The periostitis resulted from long-term therapy with PGE1, which was administered to maintain patency of the ductus in a neonate with ductal-dependent cyanotic congenital heart disease. The features of PGE1 periostitis and the differential diagnosis are reviewed.

Digital enlargement in tuberous sclerosis

Abstract A 23-year-old woman with a medical history significant for tuberous sclerosis presented with symptoms of postpartum endometritis. Focal gigantism of the third digit of her right hand was incidentally noted and is reported to be a rare manifestation of tuberous sclerosis.