Mikito Sasaki

Cementless total hip replacement with subtrochanteric femoral shortening for severe developmental dysplasia of the hip

Total hip replacement for high dislocation of the hip joint remains technically difficult in terms of preparation of the true acetabulum and restoration of leg length. We describe our experience of cementless total hip replacement combined with a subtrochanteric femoral shortening osteotomy in 20 hips with Crowe grade IV dislocation with a mean follow-up of 8.1 years (4 to 11.5). There was one man and 17 women with a mean age of 55 years (44 to 69) at the time of the operation. After placement of the acetabular component at the site of the natural acetabulum, a cementless porous-coated cylindrical femoral component was implanted following a subtrochanteric femoral shortening osteotomy. The mean Japanese Orthopedic Association hip score improved from a mean of 38 (22 to 62) to a mean of 83 points (55 to 98) at the final follow-up. The mean lengthening of the leg was 14.8 mm (-9 to 34) in patients with iliofemoral osteoarthritis and 35.3 mm (15 to 51) in patients with no arthritic changes. No nerve palsy was observed. Total hip replacement combined with subtrochanteric shortening femoral osteotomy in this situation is beneficial in avoiding nerve injury and still permits valuable improvement in inequality of leg length.

Diagnosis of peri-prosthetic infection at the hip using triple-phase bone scintigraphy

We evaluated triple-phase bone scintigraphy in the differential diagnosis of peri-prosthetic infection in 46 patients with a total hip replacement or bipolar hemiarthroplasty who were due for revision surgery. There were 18 men and 28 women, with a mean age at operation of 64.6 years (28 to 81). We defined peri-prosthetic infection as an increased uptake of radioisotope in all the phases of triple-phase bone scintigraphy and validated these results against the histological and/or microbiology results in every case. The positive and negative predictive values for the presence of infection were 83% and 93%, respectively. The diagnostic sensitivity was 88% and the specificity was 90%. This study indicates that triple-phase bone scintigraphy is a useful tool in the detection of peri-prosthetic infection and offers a cost-effective method of screening.

MRI and histological evaluation of the infiltrative growth pattern of myxofibrosarcoma.

ObjectiveMyxofibrosarcoma often shows abnormal signal infiltration along the fascial plane on magnetic resonance imaging (MRI). The objective was to describe this MRI characteristic of myxofibrosarcoma with pathologic findings for comparison.Materials and methodsClinical, histological, and imaging data for 21 patients with myxofibrosarcoma were reviewed retrospectively.ResultsSeventeen tumors showed a diffuse infiltrative pattern on MRI. All tumors with diffuse infiltrative growth pattern showed borderless extension of atypical cells with moderate nuclear atypia to the muscle fascia. Notably, the remaining four patients with focal growth pattern on MRI also demonstrated infiltrative growth pattern histologically suggesting that myxofibrosarcoma shows an infiltrative growth property even in the lack of infiltrative growth pattern on MRI.ConclusionMost myxofibrosarcoma show an infiltrative growth pattern histologically. Orthopedic oncologist should pay careful attention to accurately assess tumor extension. It seems prudent to resect the entire area of abnormal signal extension seen on MRI whenever possible to obtain an adequate surgical margin of myxofibrosarcoma.

The level of vascular endothelial growth factor as a predictor of a poor prognosis in osteosarcoma

We undertook a prospective study to evaluate the prognostic significance of the serum levels of vascular endothelial growth factor (VEGF) in predicting the survival of patients with osteosarcoma. The levels were measured by an enzyme-linked immunosorbent assay in 15 patients with osteosarcoma before commencing treatment. The patients were divided into two groups, with a high or a low serum VEGF level, and the incidence of metastases and overall survival rate were compared. No significant relationship was observed between the serum VEGF levels and gender, age, the size of the tumour or the response to pre-operative chemotherapy. Patients with a serum VEGF > 1000 pg/ml had significantly worse survival than those with a level < 1000 pg/ml (p = 0.002). The serum VEGF level may be useful in predicting the prognosis for survival in patients with osteosarcoma.

Construct validity of the Enneking score for measuring function in patients with malignant or aggressive benign tumours of the upper limb

We evaluated the construct validity of the Musculoskeletal Tumour Society rating scale (Enneking score) as a functional measure for patients with sarcoma involving the upper limb. We compared the Enneking score by examining the correlation between two patient-derived outcome measures, the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire and the Medical Outcomes Study Short Form-36 (SF-36) as indicators of functional status in 40 patients with malignant or aggressive benign bone and soft-tissue tumours of the upper limb who had undergone surgical treatment. The frequency distributions were similar among the three scoring systems. As for the validity, Spearmans rank correlation coefficient of the Enneking score to the DASH questionnaire was -0.79 and that of the Enneking to the SF-36 subscales ranged from 0.38 to 0.60. Despite being a measure from the surgeons perspective, the Enneking score was shown to be a valid indicator of physical disability in patients with malignant or aggressive benign tumours of the upper limb and reflected their opinion.

Pre-operative Selective Arterial Embolization as a Neoadjuvant Therapy for Proximal Humerus Giant Cell Tumor of Bone: Radiological and Histological Evaluation

The management of giant cell tumor of the proximal humerus that extends to the joint is challenging. Here, we report a case of proximal humerus giant cell tumor with cortical bone destruction extending to the shoulder joint. Pre-operative selective arterial embolization induced peripheral tumor ossification. Subsequently, the lesion was removed by intralesional curettage, and the cavity was filled with cement. Macroscopically, the inner wall of the cavity was found to be lined with a thick fibrous membrane. Histologically, massive fibrosis and resultant remodeling of the destroyed cortical bone were induced, which was consistent with the peripheral ossification on the plain radiograph. We believe that selective arterial embolization can be an effective neoadjuvant therapy for giant cell tumors of the extremities, especially for tumors with large cortical defects or joint involvement.

Primary total hip arthroplasty with Asian-type AML total hip prosthesis: follow-up for more than 10 years

BackgroundWe retrospectively reviewed 137 consecutive total hip arthroplasties performed with AML-A stems and Tri-Lock cups to see whether design modifications made to these components would achieve durable biological fixation in the Japanese population in whom developmental dysplasia of the hip (DDH) is relatively common. Patients from our initial clinical series using these components are available for more than 10 years– follow-up.MethodsBetween April 1988 and June 1994, we performed 137 total hip arthroplasties using the AML-A prosthesis for the patients with osteoarthritis of the hip joint. We excluded 26 hips with less than 10 years– follow-up and five hips from patients who died before the 10-year follow-up. The mean follow-up for the 105 remaining THAs is 155.2 months (range 120–237 months). The average age of these patients at the time of surgery was 53.1 years (range 22–81 years).ResultsIn total, 17 THAs required component revisions. In seven cases, the first revision was limited to a liner exchange for polyethylene wear or osteolysis. Another seven hips underwent revision surgery for recurrent dislocation. Three cups have been revised owing to aseptic loosening. Because of the high incidence of wear-related revisions, Kaplan-Meier survivorship at the 15-year follow-up, using acetabular component revision for any reason as an endpoint, was 75.0% (95% CI 69.4%–83.8%). In contrast, no revision of the femoral stem was performed. Severe stress shielding occurred in 12 hips. Thigh pain was mild, however, and all of the femoral stems remained stable.ConclusionsDespite revisions for wear-related complications, the fixation achieved with these porous-coated components remained durable throughout the 15-year follow-up. Acetabular osteolysis has been associated with cup reoperation, but femoral stress shielding has never resulted in stem loosening.

Prognostic impact of CD109 expression in myxofibrosarcoma.

CD109, a TGF‐β co‐receptor, is reported to be preferentially expressed during the early stages of tumorigenesis in several carcinoma types. Myxofibrosarcoma is one of the most common soft‐tissue sarcomas found in elderly patients. This study aimed to elucidate the impact of CD109 expression in myxofibrosarcoma on prognosis and recurrence.

Revision Total Hip Arthroplasty Due to Pain From Hypersensitivity to Cobalt-Chromium in Total Hip Arthroplasty

We report a case with hypersensitivity to CoCr in total hip arthroplasty coupled with conventional polyethylene and CoCr femoral head. The patient complained of left hip pain and systemic fever, and computed tomography imaging revealed a periprosthetic cystic lesion, so we performed revision total hip arthroplasty using a titanium stem and ceramic head and highly crosslinked polyethylene. Hip pain and cystic lesion disappeared 3 years after revision surgery.

Development of non-traumatic osteonecrosis of the femoral head requires toll-like receptor 7 and 9 stimulations and is boosted by repression on nuclear factor kappa B in rats.

Non-traumatic osteonecrosis of the femoral head (ONFH) often occurs after corticosteroid therapy in patients with inflammatory diseases. Recent studies suggest that toll-like receptor (TLR) signaling may contribute to the pathogenesis of inflammatory diseases, and that the reason for corticosteroid therapy for inflammatory diseases is related to the anti-inflammatory activities of corticosteroids through the reduction of NF-κB. We hypothesized that the administration of TLR ligands in combination with corticosteroid causes ONFH and that transcription factors may contribute to the pathogenesis of ONFH. The aim of the study was to evaluate (1) the incidence of ONFH in rats after the administration of TLR7 or TLR9 ligands together with methylprednisolone (MPSL) and (2) whether transcription factors contribute to the development of ONFH. Male Wistar rats (n=148) were divided into five groups as follows: Group 1: Saline+MPSL, Group 2: Imiquimod+Saline, Group 3: Imiquimod+MPSL, Group 4: CpG-C+MPSL, Group 5: Imiquimod+BAY11-7082+MPSL. As a result, ONFH was observed in 0 of 12 rats in Group 1, in 1 of 10 in Group 2, in 6 of 12 in Group 3, in 4 of 12 in Group 4, in 0 of 9 in Group 5. MPSL treatment did not significantly affect IRF7 activity, whereas NF-κB activity was significantly repressed in Group 2 and Group 3. Furthermore, the repression in interferon regulatory factor 7 (IRF7) activity by BAY11-7082 interfered with the development of ONFH simultaneously with the MPSL treatment-induced repression in NF-κB activity. In conclusion, in the present study, corticosteroid treatment after the administration of TLR7 or TLR9 ligands caused ONFH. Repression in NF-κB activity by corticosteroid treatment boosted the development of ONFH.