Accurate and Reliable Diagnosis of Avascular Necrosis of the Femoral Head From Total Hip Arthroplasty Specimens Requires Pathologic Examination.

OBJECTIVES: To evaluate the necessity of pathologic examination for confirming the diagnosis of avascular necrosis (AVN). METHODS: We retrospectively reviewed consecutive nonfractured total hip arthroplasty cases (n = 1,722), comparing operative diagnoses and radiologic data with final histologic diagnoses, focusing specifically on AVN. RESULTS: Among 199 histologically confirmed cases of AVN, 62 (31%) had a preoperative diagnosis of osteoarthritis/degenerative joint disease (OA/DJD); 58 of the latter patients had radiology reports, but only two (3%) documented AVN. Patients with AVN preoperatively diagnosed as OA/DJD were significantly older (mean, 65 years) than patients with AVN correctly diagnosed clinically (mean, 52 years; P < .00001). Among 163 cases with a preoperative diagnosis of AVN, 26 (16%) were confirmed as OA/DJD; the radiology report incorrectly diagnosed AVN in 17 (65%) patients. These latter patients also were significantly older (mean, 60 years) than patients with AVN correctly diagnosed clinically (P = .0008). Patients with a preoperative clinical and/or radiologic diagnosis of AVN were more likely to be younger and have known AVN risk factors. CONCLUSIONS: Accurate and reliable diagnosis of AVN requires pathologic examination, especially among older patients without known risk factors. Prompt diagnosis may lead to behavioral changes in affected patients that reduce the risk of subsequent lesions.

The Incidence and Significance of Calcium Pyrophosphate Dihydrate Deposits in Histologic Examinations of Total Hip, Knee, and Shoulder Joint Arthroplasties.

CONTEXT.­: The incidence, distribution, and significance of calcium pyrophosphate dihydrate deposition (CPPD) disease have not been extensively compared among various total joint resections. OBJECTIVE.­: To investigate and define the clinical and pathologic features of CPPD in hip, shoulder, and knee arthroplasties. DESIGN.­: We retrospectively reviewed consecutive total hip, knee, and shoulder arthroplasty cases (N = 3195) confirmed pathologically between January 1, 2017, and October 10, 2018, comparing clinical and pathologic data. RESULTS.­: Among 2004 hip arthroplasties, 61 (3%) had CPPD on pathologic examination; the majority had a histologic diagnosis of osteoarthritis, followed by fracture and avascular necrosis. Of 1113 knee arthroplasties, 98 (9%) had CPPD; all had a histologic diagnosis of osteoarthritis. Among 78 shoulder arthroplasties, 10 (13%) had CPPD; all but one had a histologic diagnosis of osteoarthritis. Patients with hip and knee CPPD were significantly older than those without CPPD. Of the 169 pathologically detected CPPD cases, only 35 (21%) were documented on preoperative radiologic images or by other clinical means; radiology reports were significantly more likely to document chondrocalcinosis in the knees than in the hips. Histologically, CPPD was noted almost exclusively in the separately submitted soft tissues/joint capsule, concomitantly involving the articular cartilage surface in only 3.0% (5 of 169) of cases. CONCLUSIONS.­: Calcium pyrophosphate dihydrate deposition is more than twice as likely to occur in the knees and shoulders compared with the hips. Patients with CPPD in the knees or hips are usually not recognized preoperatively/radiologically and constitute a significantly older population. Reliably establishing the diagnosis of CPPD requires pathologic examination of the submitted soft tissue/joint capsule.

Outcomes of Medial Collateral Ligament Injuries during Total Knee Arthroplasty.

Intraoperative medial collateral ligament (MCL) disruption during total knee arthroplasty (TKA) is often managed with either primary repair or use of a constrained implant. A total of 23 patients with an MCL injury during TKA between 2003 and 2009 were compared with 92 matched controls. Of the 23 patients, 10 were treated with an unconstrained implant and primary MCL repair, 8 with constrained implants, 3 with constrained implants and MCL repair, and 2 with unconstrained implants and no MCL repair. After an average 5-year follow-up, patients had lower Knee Society Scores (KSS), 79 versus 87 (p = 0.03), but similar Knee Function Scores (KFS), 68 versus 72 (p = 0.35). The improvement between preoperative and postoperative KSS and KFS did not vary among the two groups (p = 0.88 and p = 0.77, respectively). Postoperative scores did not vary significantly among the four treatment modalities. Conservative treatment can provide satisfactory outcomes and avoid potential complications of increased constraint.

Molecular genetics of pancreatic neoplasms and their morphologic correlates: an update on recent advances and potential diagnostic applications.

OBJECTIVES: To summarize the most clinically and biologically relevant advances in molecular/genetic characteristics of various pancreatic neoplasms, with morphologic correlation. METHODS: Whole-exome sequencing of numerous benign and malignant pancreatic tumors, along with the plethora of highly sensitive molecular studies now available for analyzing these tumors, provide mounting evidence to support the long-held belief that cancer is essentially a genetic disease. These genetic discoveries have not only helped to confirm the age-old, morphology-based classifications of pancreatic neoplasia but have shed new light on their mechanisms. Many of these molecular discoveries are currently being used in preoperative diagnosis. RESULTS: Mutations in KRAS, P16/CDKN2A, TP53, and SMAD4/DPC4 are commonly seen in ductal neoplasia but not in nonductal tumors; ductal adenocarcinomas with SMAD4/DPC4 loss are associated with widespread metastasis and poor prognosis. GNAS and RNF43 mutations have been discovered in most intraductal pancreatic mucinous neoplasms, providing critical molecular fingerprints for their diagnosis. Mutation in DAXX/ATRX is only seen in pancreatic neuroendocrine tumors, making it a useful potential marker in distinguishing these tumors from mimics. CONCLUSIONS: When combined with morphologic observations, molecular studies will increase our understanding of the pathogenesis and morphomolecular signatures associated with specific neoplasms and provide new horizons for precision medicine and targeted therapies.