Under-reporting by surgical pathologists in tissue removed during revision surgery for metal-on-metal arthroplasties.

Although adverse local tissue reactions (ALTR) have been reported for metal-on-metal implants (MoM) requiring early revision surgery, no study has looked at the accuracy of surgical pathologists in diagnosing ALTR. This study aims to investigate the accuracy of reporting adverse local tissue reactions in tissue samples following revision surgery from metal-on-metal implants. The authors reviewed histology glass slides as well as the original pathology reports of tissue processed in revision arthroplasties in 23 cases. These samples were microscopically analyzed for tissue necrosis and cystic degeneration, the presence of metal particles, corrosion byproducts, membrane formation, histiocytic cells, lymphocytic cells, and vascular pathology. The authors' findings were then compared to their corresponding original pathology reports. The authors found consistent under-reporting of the tissue findings. Most importantly, 18 samples showed evidence of metal present compared to 2 samples on original pathology reporting. The authors found that 15 samples showed evidence of pathological membranous tissue compared to just 6 on original pathology reporting. While just 3 of the original pathology reports indicated the presence of areas of predominantly lymphocytic inflammatory cells, the authors found 13 examples of such areas. Although ALTR reactions have been described as a sequala of failed MoM, the authors' data suggest that ALTR may occur more frequently than previously described. Under-reported findings of ALTR deprive both the patient and orthopaedic surgeon of important information that can help guide further follow-up.

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.

Hyaluronan Injections Show No Histologic Evidence of Adverse Tissue Effects.

BACKGROUND: The safety of hyaluronan intra-articular injections is mostly based on animal studies and clinical evidence rather than histologic studies from human administration. OBJECTIVE: This study analyzed the histologic effects of viscosupplementation with sodium hyaluronate on the synovium and articular cartilage of human knee specimen status post total knee arthroplasty within 3 years of viscosupplementation. METHODS: Twenty-four specimens from total knee arthroplasties from April 2012 to August 2016 at NYU Winthrop Hospital were selected for microscopic analysis. All cases had a diagnosis of end-stage osteoarthritis at the time of surgery. Thirteen of the cases had 3 viscosupplementation injections of the knee with Euflexxa, a hyaluronate-based viscosupplementation agent, within 3 years preceding a total knee replacement. The remaining 11 did not receive viscosupplementation and were incorporated as controls. Upon histologic review, synovium was categorized by degree of hyperplasia and inflammation and the presence or absence of foreign material and giant cell reactions. Residual articular cartilage was categorized by staining intensity, and the presence or absence of crystals, foreign material, and giant cell reactions. RESULTS: No significant difference was found between these groups for degree of synovial hyperplasia (P = .33) or for cartilage staining density (P = .42). None of the samples displayed evidence of foreign material, crystals, or giant cell reactions. CONCLUSION: In this cohort of patients, we demonstrated that Euflexxa was administered without any discernible microscopic adverse tissue effects.

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.

Histological Findings in Six Failed Metal-on-Metal Implants.

Although joint replacement surgery to relieve pain due to osteoarthritis is generally a successful operation, adverse local tissue reactions can occur in hip arthroplasty in patients who receive metal-on-metal (MoM) implants and lead to early failure. This has led to revisions, lawsuits, and manufacturing recalls. An understanding of the pathological process initiated by metal wear debris is essential in clinical surveillance of cases. We retrospectively reviewed six cases of patients who underwent MoM hip arthroplasties and required early revision. Tissue removed at revision surgery was analyzed histologically by two independent reviewers. All six patients (four males, two females) underwent revision hip arthroplasty after early failure. Revision occurred between 18 and 56 months after the index procedure. Four patients received MoM implants from Depuy, one from Stryker, and one from Wright Medical. A consistent array of pathological findings was associated with these failed MoM implants. Beginning with the development of metal debris, a histiocytic response and proliferation occurred with subsequent corrosion product formation. Membranes were formed, many with cellular infiltrates and pseudosynovial linings and often with ulceration and bleeding. The tissue also demonstrated lymphocytosis and perivascular infiltrates with atypical changes of the endothelial lining cells. Our findings document a predictable cascade of harmful local tissue changes initiated by metal debris in failed MoM hip arthroplasties.

Atypical Tumoral Presentation of Calcium Pyrophosphate Deposition Disease: A Case Report.

CASE: A 55-year-old man presented with a history of forefoot pain and swelling. Radiographs revealed a mass with internal calcifications and osseous erosion of the fifth metatarsophalangeal bone. The mass was isointense to muscle on T1-weighted magnetic resonance imaging (MRI) and hyperintense on T2-weighted MRI. A biopsy was performed, and intraoperatively, the lesion appeared as chalky white material, which under polarized light microscopy was composed of weakly positively birefringent rhomboid crystals, leading to a diagnosis of tophaceous pseudogout. CONCLUSION: Tophaceus pseudogout should be included in the differential diagnosis of neoplastic-appearing lesions in the foot, and polarized light microscopy should be used when examining biopsy specimens.

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.

Collagen scaffold meniscus implant integration in a canine model: a histological analysis.

In the situation of an irreparable meniscus tear, an implant comparable to a normal meniscus is an attractive option. Using a canine model, we assessed the early and late histologic response to a tissue engineered meniscal collagen scaffold (CS). All animals received bilateral arthrotomies, and all joints receiving the CS had an 80% resection of the meniscus. Animals were sacrificed at 3 and 6 weeks, and 12, 13, and 17 months. The CS/tissue complex and host meniscal rim were sectioned for histologic examination with specific focus on the extracellular matrix, angiogenesis, cellular resorption of the scaffold, scaffold appearance, and CS/Host integration. Early histologic samples (3-6 weeks) revealed active angiogenesis and fibrin clots evolving into cellular granulation type tissue. At 12 months, a mature fibrochondrocytic matrix was depositing with gradations of dissolution and integration of the CS implant. Maturing CS/host integration was observed at 18 months. Active cellular resorption of the implant decreased over time. Four cases showed a mild non-specific chronic inflammation and one additional case showed inflammatory engulfment of the scaffold with giant cells at 3 weeks. No evidence of infection either clinically or histologically was observed at any time point. Overall, this histologic analysis demonstrated the active integration of a meniscal like cartilage into a tissue engineered biological scaffold in a canine model.

The human knee meniscus: a review with special focus on the collagen meniscal implant.

The human knee meniscus is important for the protection of the knee joint from degeneration. Because it is so commonly injured, several methods have been developed to replace damaged meniscal tissue with either transplanted menisci or other synthetic implants. Here we review these different approaches, with a clinical and histological focus on the collagen meniscal implant (CMI or Menaflex), a tissue-engineered bovine collagen product. Clinical trials in patients receiving the CMI have demonstrated good clinical outcomes in follow-ups as long as 10 years. We review the findings of second-look biopsies of implanted CMI constructs; they demonstrate the fibrochondrocytic ingrowth of tissue mimicking a native meniscus. Integration of the CMI to host meniscus is also confirmed. The histologic inflammation occasionally observed around the graft appears to be of little clinical significance. We conclude that tissue-engineered menisci from bovine collagen are safe in the time period examined and that they hold promise for future repair of the meniscus in appropriate individuals.

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.

Nodular skin metastasis mimicking infection in a revision total hip arthroplasty scar.

We present the case of a 60-year-old man who had metastasis of a nodular squamous cell carcinoma from a laryngeal carcinoma that mimicked an infected sinus in a 4-month postoperative revision total hip arthroplasty scar. A diagnosis was made at the time of frozen section. The patient died 3 months after tumor resection as a result of multiorgan failure. Nodular squamous cell carcinoma metastasis in a total hip arthroplasty scar is extremely uncommon. However, this association must be considered in a patient with a known tumor after revision surgery. In such patients, we recommend obtaining an intraoperative frozen section to avoid misdiagnosis in cases of infected sinuses associated with implants.

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.