Macrodystrophia Lipomatosa of the Foot: A Case Report of MRI and Histologic Findings Including Pacinian Corpuscle Abnormalities.

CASE: A 37-year-old man presented with pain and macrodactyly of a toe. Imaging and histology demonstrated findings consistent with macrodystrophia lipomatosa (MDL). We compared our findings with control tissue obtained from an identical site of a fresh-frozen cadaveric foot from the same anatomical site. Pacinian corpuscles (PCs) in the MDL tissue were increased in number, size, and shape compared with the control tissue and demonstrated edematous interstitial lamellae and vacuolar degenerative change. We also document the magnetic resonance imaging findings of the PCs. CONCLUSION: Peculiar abnormalities of PCs in MDL underline nerve damage and may be a contributing factor in the pain associated with this unusual condition.

A Histologic Analysis of a Retrieved Specimen 24 Years after Hemiresurfacing for Avascular Necrosis.

Reports of long-term evaluation of the viability of the femoral head after a hemiresurfacing arthroplasty (HRA) are scarce. We report the case of a 41-year-old female with lupus and right HRA (performed 24 years previously for avascular necrosis) that was revised to a total hip arthroplasty for worsening right groin pain due to chondrolysis. We present a histologic evaluation of the resurfaced femoral head retrieved 24 years after HRA. To the authors' knowledge, this is the longest reported histologic follow-up of such a case. There was no evidence of fracture or inflammation and the underlying bone was viable. At 5-year follow-up after the revision, the patient is pain-free, fully functional, and walks without any assistive device.

Fracture of the Neck of a Lateral Flare Femoral Implant in Total Hip Arthroplasty.

We present the case of a 38-year-old man who presented 7 years after primary total hip replacement with a fracture of the neck of a lateral flare femoral stem and catastrophic polyethylene wear. The unique design of the lateral flare hip stem has been shown previously to be associated with accelerated polyethylene wear, whereas the stem remains well fixed. The resultant polyethylene wear results in the harder cobalt chrome head abrading the titanium shell generating metallic debris. This may have resulted in proximal migration of the implant neck into the cup with subsequent neck-cup impingement and implant fracture.

Intraosseous hibernoma: a case report and review of the literature.

STUDY DESIGN: A case report and a literature review are presented. OBJECTIVE: To describe and review the clinical presentation and characteristic imaging and pathology findings of intraosseous hibernoma. SUMMARY OF BACKGROUND DATA: Hibernomas are lesions of brown fat. Brown fat is typically found in newborn mammals and is rich in mitochondria, thus enabling its role in thermoregulation. It represents a small proportion of adult fat and is distinct from the more common "white fat." Rarely does a hibernoma occur within bone. To the authors' knowledge, 5 cases in all have been reported in the literature. METHODS: We report the first case to our knowledge of an intraosseous hibernoma occurring within the lumbar spine as well as a review of the literature. RESULTS: Characteristic findings from magnetic resonance studies include variable T1W signal relative to skeletal muscle and hyperintense signal on fluid-sensitive imaging. Computed tomography has consistently demonstrated a sclerotic lesion with variable definition. Pathologic findings include sheets of multivacuolated cells with centrally placed nuclei and numerous tiny surrounding cytoplasmic vacuoles overlying bony trabeculae. CONCLUSION: Our review of the literature demonstrates that intraosseous hibernoma is most likely an incidental finding with a predilection for the lower extremities in middle-aged females. LEVEL OF EVIDENCE: 4.

Granulomatous salmonella osteomyelitis associated with anti-tumor necrosis factor therapy in a non-sickle cell patient: a case report.

Salmonella osteomyelitis is seen most commonly in patients with sickle cell disease and in those with compromised immune systems. We report on the clinical, histological and imaging findings of salmonella osteomyelitis with intraosseous abscess formation occurring in a non-sickle cell patient receiving anti-tumor necrosis factor (TNF) alpha therapy.

Neovascularity in chronic posterior tibial tendon insufficiency.

Insufficient posterior tibial tendons in 28 specimens from patients with clinical Stage II or III disease were examined to clarify the etiology of adult-acquired flatfoot deformity. Hematoxylin and eosin and Masson trichrome-stained sections of formalin-fixed tissue were viewed in plain and polarized light. We performed a qualitative analysis for abnormalities in collagen orientation, degree of vascularization, tenocyte cellularity, mucinous change, and chondroid metaplasia. Tendons were divided into three zones: tenosynovial lining cell layer, subtenosynovial lining cell layer, and tendon proper. All tendons showed neovascular infiltration causing collagen fibril disruption; 50% of specimens had diffuse involvement. Increased mucin content and chondroid metaplasia occurred in 28% and 36% of specimens, respectively. The tenosynovial lining cell layer showed hyperplasia in 28% of specimens. The subtenosynovial lining cell layer showed thickening and neovascularization in 79% of specimens, which appeared to be the source for the diffuse neovascular infiltrative process. There is little histopathologic evidence to support an inflammatory etiology to the posterior tibial tendons in acquired-adult flatfoot deformity. Neoangiogenesis, the prominent histologic finding, is consistent with an obscure insult. We postulate that overuse, tension, or stretching may activate the tenosynovial lining cells and incite angiogenesis.

Case Reports: osteosarcoma of the hand: one case and a literature review.

Osteosarcoma of the hand is rare. We present a case report and a literature review that indicates an older median age of onset than conventional osteosarcoma. The predilection for these lesions to manifest in the metacarpophalangeal joints, particularly in the second and third digits, is in contrast to the more symmetrical distribution of metastatic cancer and correlates with the sites of most active growth during development of conventional osteosarcoma.

Bone biopsy as a screening technique for bone bank allograft donation.

The objective of the study was to investigate occult abnormalities in bone bank allograft with the use of histomorphometry that may otherwise go unidentified with current screening techniques. This was a prospective pathology review in which 40 transcortical trephine bone biopsies were taken from the iliac crest of bone donors and examined by light microscopy and semiautomated histomorphometry. Current routine screening techniques for allograft bone donors include history, serology, and culture. Additional screening for unsuspected pathology and for parameters related to metabolic bone disease may predict the effectiveness of the donor bone. Light-microscopic findings showed 1 case suspicious for chronic myeloproliferative disorder, which had otherwise not been detected by standard screening techniques. On histomorphometric analysis, 3 specimens showed severe osteoporosis. In conclusion, iliac crest bone biopsy may need to be considered as an adjunct in screening for both unsuspected hematological disease and metabolic bone disease.

A quantitative histologic comparison: ACL degeneration in the osteoarthritic knee.

Newer prosthetic total knee arthroplasty (TKA) designs as well as unicondylar TKAs spare the anterior cruciate ligament (ACL). Although success of these procedures requires near normal ACL function, little has been written about the histologic features or the arthritic ACL. This study was designed to histologically evaluate the ACL for microscopic evidence of degeneration. Nineteen ACLs were harvested from 16 different patients who underwent TKA as a result of severe osteoarthritis. Control ligaments were obtained from bone bank donors (N = 14), patients with above-knee amputations (N = 5), and cadaveric formalin-preserved knees (N = 6). Orientation was maintained for each ACL. Degenerative parameters included loose, fibrous connective tissue and myxoid and cystic occurrences, and the presence of chondroid metaplasia or calcium phosphate crystals were evaluated and scored. Forty-seven percent of the osteoarthritic group had moderate/marked degeneration, whereas no control specimen showed such changes. Seventy-two percent of the controls were considered normal, compared with only 26% of the osteoarthritic group. Both of these findings were statistically significant (P<.001). Statistical analysis revealed no gender bias either within or between groups. In the control group, no statistical difference was found between patients older than age 65 and those younger than 65. In the osteoarthritic group, however, 70% of patients younger than 65 demonstrated moderate/marked changes compared with only 22% of those older than 65 (P<.05). There also was no difference demonstrated between the 4 focal sections of the ligaments that were examined.

Ultrastructural features of giant cell tumors in Paget's disease.

Giant cell tumor is a rare complication of Paget's disease. This association is especially notable in patients originating from Avellino, Italy. Many types of evidence point to a viral etiology for Paget's disease and giant cell tumors arising in it. Three patients who had giant cell tumors and Paget's disease were studied. Two of the patients have a connection to Avellino (one was born in Avellino, and one descended from natives of Avellino). Distinctive light microscopic and ultrastructural features common in these three patients were identified. In all three patients, the giant cell tumors had peculiar irregular aggregates of microfilaments of uncertain genesis. The possibility that these reflect viral infection is discussed.

Osteoclast dysfunction in the osteosclerotic variant of renal osteodystrophy.

Six iliac crest bone biopsies were obtained from five patients with renal osteodystrophy and osteosclerotic lesions to investigate the mechanism of osteosclerosis in renal osteodystrophy. Each specimen was prepared in an undecalcified fashion and measured under light microscopy for routine analysis and histomorphometry. Osteoclast resorptive lacunae were estimated by measuring the lacunar length and depth. Histomorphometric studies revealed an increase in all parameters with a mean trabecular bone volume of 66% (normal: 19%-26%), mean trabecular osteoid surface of 71% (normal: 16%-22%), and a mean trabecular osteoid volume of 15% (normal: 1%-2%). In one patient, there was a ten-fold increase over the norm of osteoclasts/mm2 (0.3; normal: 0.02-0.04), whereas the mean width of trabecular bone was twice the norm. In all biopsies, the calculated lacunar area was markedly diminished compared to published controls. These results support the hypothesis that osteoclast function is impaired in patients with renal osteodystrophy.

Ischial bursal chondromatosis.

A right ischial ulcer recurred after 6 months in a 79-year-old man with a history of recent hip fracture and Girdlestone procedure. Soft-tissue calcification was detected radiographically. The mass, hyperplastic bursal tissue with chondroid metaplasia, was excised. Bursal osteochondromatosis is reviewed.