Kohei Negoro

Chronic expanding hematoma of the thigh

Hematomas following surgery or trauma usually resolve without complications. In some instances, for reasons that are not completely understood, hematoma formation is followed by slow expansion of the mass. The large fluid collection is surrounded by a pseudocapsule and fibrous tissue, and present months or years after the original insult, as chronic expanding hematoma. In this case study, we present a rare case of chronic expanding hematoma in an 84-year-old woman. The patient noted a painful swelling in the posteromedial aspect of the lower thigh, and recalled a bump to the left knee 64 years earlier. The lesion was successfully resected, with a preoperative presumptive diagnosis of organized hematoma, although the clinical findings were suggestive of malignancy. We describe the radiological findings, discuss the differential diagnosis.

Direct detection of pathogens in osteoarticular infections by polymerase chain reaction amplification and microarray hybridization

BackgroundMolecular biological techniques such as the polymerase chain reaction (PCR) and DNA microarray are used for the detection/identification of microorganisms; however, few reports have discussed the clinical utility of microarray analysis for identification of causative organisms of osteoarticular infections. It is important to examine the utility of PCR amplification followed by analysis of DNA microarray carrying specific oligonucleotides.MethodsThis study included 101 biological samples obtained from 96 patients who underwent conservative and/or surgical treatment for osteoarticular infections. In this double-blind comparative study, routine conventional testing and the research groups were unaware of each other’s interpretation until identical specimens were identified by culture and microarray analysis.ResultsResults of PCR microarray analysis were positive for 25 samples and negative for the remaining 76 samples within 24 h, and the results of the cultures (available after a mean of 3.54 days) were positive in 26 samples and negative for the remaining 75 samples. The sensitivity of microarray analysis was 84.6% (22/26) and specificity was 88.0% (22/25). Discrepant results were identified in seven samples, including a negative culture and a positive microarray in three cases and a positive culture and a negative microarray in four other cases.ConclusionsThe PCR microarray analysis is complementary to routine cultures in identifying causative microorganisms and should be used in patients with highly suspected infections and negative bacterial culture and in patients who require prompt diagnosis and early initiation of antibiotic therapy.

Metaphyseal-loading anterolaterally-flared femoral stem in cementless total hip arthroplasty: five- to eleven-year follow-up evaluation.

Using a nonlinear three-dimensional finite element analysis simulating loading conditions, we designed a new type of proximal-fitting, anterolaterally-flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; Japan Medical Materials, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis. The aim of the present study was to analyze the clinical and radiographic outcomes of the new stem. We reviewed 143 consecutive patients (164 hips; 13 men, 14 hips; 130 women, 150 hips; age at surgery, 56.6 +/- 7.6 years, mean +/- SD, range, 30-74) who underwent cementless THA using the FMS-anatomic stem at a single institution, with a follow-up period of 7.6 +/- 1.6 years (range, 5.3-11.0). Harris Hip score improved from 46.1 +/- 12.6 before surgery to 90.0 +/- 8.9 points post-THA. The 7.6-year survival rate of the stem was 99.0% after revision for aseptic loosening. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0 degrees . The FMS-anatomic stem provided excellent results in patients with dysplastic hip osteoarthritis. Our analysis confirmed reduced radiolucency around the stem in Gruen zones, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal in our patients.

Modified Metaphyseal‐Loading Anterolaterally Flared Anatomic Femoral Stem: Five‐ to Nine‐Year Prospective Follow‐Up Evaluation and Results of Three‐Dimensional Finite Element Analysis

We have designed a proximal-fitting, anterolaterally flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; KYOCERA Medical, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis, using a nonlinear three-dimensional finite element analysis simulating loading conditions. The Anatomic Fit stem was modified in the region of the arc-sprayed surface, to allow more proximal appearance of spot welds. The aim of the present study was to analyze the clinical and radiographic outcomes of patients who underwent THA using this stem. We reviewed 73 consecutive patients (79 hips; 13 men 16 hips; 60 women 63 hips; age at surgery, 57.6 years, range, 35-78) who underwent cementless THA using the Anatomic Fit stem, at a follow-up period of 7.1 years (range, 5.1-9.4). Harris Hip score improved from 40.7 ± 17.1 before surgery to 91.0 ± 5.2 points at follow-up. The 7.1-year stem survival rate was 100%. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0°. The Anatomic Fit stem provided excellent results. The nonlinear three-dimensional finite element analysis demonstrated that the stem-bone relative motion was 10 µm at the proximal end of the stem and proximal load transfer. Our analysis confirmed reduced radiolucency around the stem, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal.

Intraneural blood flow analysis during an intraoperative Phalen's test in carpal tunnel syndrome

Phalens test has been one of the most significant of clinical signs when making a clinical diagnosis of idiopathic carpal tunnel syndrome (CTS). However, it is unknown whether intraneural blood flow changes during Phalens test in patients with CTS. In this study, an intraoperative Phalens test was conducted in patients with CTS to observe the changes in intraneural blood flow using a laser Doppler flow meter. During Phalens test, intraneural blood flow showed a sharp decrease, which lasted for 1 min. Intraneural blood flow decreased by 56.7%–100% (average, 78.0%) in the median nerve relative to the blood flow before the test. At 1 min after completing the test, intraneural blood flow returned to the baseline value. After carpal tunnel release, there was no marked decrease in intraneural blood flow. This study demonstrated that the blood flow in the median nerve is reduced when Phalens test is performed in vivo.

Retroperitoneal hematoma with bone resorption around the acetabular component after total hip arthroplasty: a case report and review of the literature

IntroductionVascular complications related to cup-fixating screws penetrating the medial acetabular wall during total hip arthroplasty are not uncommon but rarely are associated with serious adverse events in the late post-operative period.Case presentationWe present the case of a 77-year-old Japanese woman who developed progressive extensive bone resorption and large hematoma in the acetabulum 13 years after total hip arthroplasty. On admission to our hospital, she was on oral warfarin (1.5mg/day) for atrial fibrillation. About 5 months after the initiation of anticoagulant therapy, she suffered a major fall followed by massive subcutaneous and pelvic girdle bleeding, predominantly on the medial side of the right thigh, but a fracture or damage of total hip arthroplasty was not evident on an emergency orthopedic evaluation. One year after the accident, a routine follow-up examination showed an asymptomatic osteolytic lesion in the acetabulum on the right pelvis, and 2 years later our patient noticed progressive pain in her right hip during walking. A large osteolytic lesion was noted in the right acetabulum on a plain radiograph. On high-resolution computed tomography and magnetic resonance imaging, a huge granulomatous lesion in the acetabulum was suggestive of chronic hematoma in intrapelvic and extrapelvic gluteal regions. A closer computed tomography examination showed that one of the screws used for fixation of the acetabular component in the total hip arthroplasty had penetrated the acetabular bone and had reached the pelvic cavity. Surgery was performed in a single session by means of two approaches: anterior midline transperitoneal address to resect the low-density mass lesion followed by posterolateral acetabular implant re-settlement.ConclusionsThough rare, total hip arthroplasty-related late vascular complications could be serious and potentially affect the limb and quality of life.

Functional outcome of patients with unstable pelvic ring fracture.

The purpose of this study was to evaluate factors that correlated with unsatisfactory short- and long-term outcome in patients who sustained unstable pelvic ring fracture. The study subjects of this study were those of type B and C pelvic ring fractures (82 patients; mean age 54 years). Age, gender, associated injuries, fracture type, Injury Severity Score rating and treatment methods were assessed, and Majeed score for functional outcome and radiographic studies at 1 year after injury (short-term) and at final follow-up (long-term), with mean follow-up of 98 months were analyzed. Significant univariate factors (p < 0.05) were entered in a multivariate logistic regression model to determine the independent predictors of unsatisfactory functional outcome. Univariate analysis showed that fractures of the lower extremity, nerve damage, conservative treatment, and radiological outcome correlated with unsatisfactory short-term functional outcome, while female gender, brain injury, nerve damage, conservative treatment, fracture location at the posterior portion of pelvic ring, radiological outcome, and pure sacroiliac dislocation only for type C fracture correlated with unsatisfactory long-term outcome. Multiple logistic regression analysis identified fractures of the lower extremity (odds ratio (OR): 5.364), conservative treatment (OR: 13.690), and nerve damage (OR: 21.392) as determinants of unsatisfactory short-term functional outcome and nerve damage (OR: 66.926) and poor radiological results (OR: 33.944) as determinant of long-term functional outcome. In patients with unstable pelvic ring injury, fractures of the lower extremity, conservative therapy, and nerve damage influenced short-term functional outcome, while that nerve damage and the pelvic ring displacement over 20 mm negatively affected long-term outcome.

Reconstruction of acetabulum in revision total hip arthroplasty for pelvic discontinuity: report of a difficult case requiring four revision arthroplasty.

BackgroundMassive bone defects of the acetabulum with pelvic discontinuity are one of the major problems in revision total hip arthroplasty. Several techniques have been described for repair of acetabular defect; however, reconstruction of acetabulum with massive bone defect is still a major problem. We describe a patient who required four revision total hip arthroplasty during a 24-year period.FindingsThe acetabulum with pelvic discontinuity was successfully reconstructed by stabilization of the posterior column with a plate commonly used for fracture treatment, and stabilization of the anterior column by reinforcement device commonly used for acetabular reconstruction. Fixation of both acetabular columns provided significant improvement of component stability.ConclusionsIn the case of pelvic discontinuity with massive acetabular bone defect, reconstruction by stabilizing both acetabular columns using reconstruction plate and KT plate is one of the better surgical options.

Cutaneous squamous cell carcinoma (SCC) arising in stump of amputated finger in a patient with resected glossal SCC

BackgroundCutaneous squamous cell carcinoma (SCC) of the hands and fingers are sometimes locally aggressive; with higher rates of regional metastasis than other cutaneous SCC, although distant metastasis is rare.Case presentationWe present the case of a 62–year-old Japanese man with double cancers: a tongue SCC and a cutaneous SCC. Swelling of the finger lesion developed gradually around the entire remaining middle finger after accidental amputation at the proximal interphalangeal joint. Histopathological examination of the tumor on the stump of the amputated finger indicated a well-differentiated SCC. The past history indicated surgery for SCC of the tongue 3 years earlier; with histopathology of moderately-differentiated SCC.ConclusionSince dedifferentiation is unlikely in metastatic tumors, the cutaneous SCC of the finger is unlikely to have originated from the tongue SCC. Alternatively, the double cancer may be two unrelated lesions or the tongue tumor could have originated from the cutaneous SCC.