Assessment of the function and resistance of sternoclavicular ligaments: A biomechanical study in cadavers.

BACKGROUND: Few biomechanical studies have assessed the resistance of the ligamentous structures of the sternoclavicular joint, and none have reproduced the physiological movements of the joint. Determining the structures that are injured in sternoclavicular dislocations is important for the surgical planning of acute or chronic ligament reconstruction. METHODS: Forty-eight joints from 24 human cadavers were studied, and they were divided into 4 groups of 12 joints each (retraction, protraction, depression and elevation). Biomechanical testing assessed primary and secondary failures. The mechanical resistance parameters between movements that occurred on the same plane (depression versus elevation, protraction versus retraction) were compared. RESULTS: The posterior sternoclavicular ligament was the most injured structure during the protraction test, but it was not injured during retraction. The anterior sternoclavicular ligament was the most affected structure during retraction and depression. The costoclavicular ligament was the most affected structure during elevation. Joint resistance was significantly greater during protraction movements when compared to retraction (P<0.05). CONCLUSION: The anterior sternoclavicular ligament was the most affected structure during retraction and depression movements. During protraction, lesions of the posterior sternoclavicular ligament were most frequent during elevation, and the costoclavicular ligament was the most frequently injured ligament. The resistance of the sternoclavicular joint was significantly greater during protraction movement when compared to retraction. LEVEL OF EVIDENCE: IV, basic science, biomechanics, cadaver model.

Developmental and functional evidence of a role for Zfhep in neural cell development.

The rat Zfhep gene encodes a member of the Zfh family of transcription factors having a homeodomain-like sequence and multiple zinc fingers. We examined expression of Zfhep in the rat forebrain during embryonic and postnatal development. Zfhep mRNA was strongly expressed in the progenitor cells of the ventricular zone around the lateral ventricles on E14 and E16, but showed little expression in cells that had migrated to form the developing cortex. Dual labeling with PCNA demonstrated expression of Zfhep mRNA in proliferating cells. Expression of Zfhep in the ventricular zone decreases during late development as the population of progenitor cells decreases. This pattern is distinctly different from other members of the Zfh family. We also examined the expression of Zfhep protein during retinoic acid-induced neurogenesis of P19 embryonal carcinoma cells. Zfhep is highly expressed in P19 neuroblasts, and expression decreases by the time of morphological neurogenesis. Hence, both P19 cells and embryonic brain demonstrate a loss of Zfhep expression during the transition from proliferating precursor to differentiated neural cells. We investigated a possible link between Zfhep and proliferation by treating human glial cell lines with Zfhep antisense phosphorothioate oligodeoxynucleotides. Two Zfhep antisense oligonucleotides repressed proliferation of either U-138 or U-343 glioblastoma cells more than control oligonucleotides. Based on the expression patterns of Zfhep in vivo and in the P19 cell model of neurogenesis, we suggest that Zfhep may play a role in proliferation or differentiation of neural cells.

The use of a modular titanium endoprosthesis in skeletal reconstructions after bone tumor resections: method presentation and analysis of 37 cases.

We analyzed 37 patients who underwent segmental wide resection of bone tumors and reconstruction with a modular titanium endoprosthesis at the Orthopaedic Oncology Group, between 1992 and 1998. Twelve patients were male and 25 were female, with a mean age of 30 years (9 - 81). The mean follow-up was 14 months (2 - 48). The diagnoses were: osteosarcoma (14 cases), metastatic carcinoma (10), Ewing's sarcoma (4), giant cell tumor (4), malignant fibrous histiocytoma (3), chondrosarcoma (1), and aneurysmal bone cyst (1). Eleven articulated total knee, 8 partial proximal femur with bipolar acetabulum, 8 partial proximal humerus, 3 total femur, 2 partial proximal tibia, 2 diaphyseal femur, 2 diaphyseal humerus, and 1 total proximal femur with cementless acetabulum endoprosthesis implant procedures were done. The complications related to the procedure included: infection (5 cases), dislocation (3), module loosening (1), and ulnar nerve paresthesia (1). We used the following criteria for the clinical evaluation: presence of pain, range of motion, reconstruction stability, surgical and oncologic complications, and patient acceptance. The results were good in 56.8% of the cases, regular in 32.4% and poor in 10.8%.

[Osteoblastoma: analysis of the treatment of 24 cases]. / Osteoblastoma: análise do tratamento de 24 casos.

The authors study 24 patients with the histologic diagnosis of osteoblastoma treated from 1953 to 1996, with a mean follow-up of 33.4 months. Two were considered as a malignant osteoblastoma. Twenty-two cases were operated, and in 2 of these was performed only a selective embolization to pelvic and spine localization. It was discussed clinical and radiographic aspects and the response to treatment. It was obtained 20 good and 4 poor results.

[Current status of the treatment of high grade bone sarcomas]. / Momento atual do tratamento dos sarcomas ósseos de alta malignidade.

The authors present a review of the changes occurred in the treatment of high grade bone sarcomas in the last 20 years. It was discussed the multidisciplinary approach for the local and systemic control of these tumors particularly the neoadjuvant chemotherapy that leads to an increase in the overall survival not only for the osteosarcoma but also for the Ewing sarcoma. They showed the possibilities for limb reconstruction after wide resection of the lesion that includes non conventional endoprosthesis and allografts.

[Surgical approach to giant cell tumors of the distal radius]. / Abordagem cirúrgica do tumor de células gigantes da extremidade distal do rádio.

The authors review 15 patients with giant cell tumor of the distal part of the radius in the period from 1980 to 1993. Pain was always present. The treatment of stage 2 with marginal resection and methylmethacrylate yielded excellent result. In the treatment of stage 3 the authors emphasize the need of wide resection. In these patients the best functional results were obtained with the use of vascularized proximal epiphyseal fibular graft, preserving some painless mobility of the wrist and forearm.

[The use of hydroxyapatite in the surgical treatment of benign non aggressive bone lesions]. / O emprego da hidroxiapatita no tratamento cirúrgico das lesões ósseas benignas não agressivas.

The authors studied, in the period 1990-1993, 31 patients with benign non aggressive bone lesions, surgically treated with intralesional resection followed by the introduction of hydroxyapatite. Their follow-up was two years and one month. The authors discussed the surgical indications, the operative technique employed, and the post-operative results which were considered to be good in 29 of the patients studied. Occurred complications in three patients: local infections in two and sterile fistula in one. It is concluded that the use of hydroxyapatite is a good option as substitute of the autologous bone graft.

Chondromyxoid fibroma: a study based on 18 cases.

The authors report on 18 cases of chondromyxoid fibroma seen at the Institute of Orthopedics and Traumatology, University of São Paulo, from 1953 to 1990. A survey of the literature on chondromyxoid fibromas was conducted and radiographic analysis of all cases is presented, with a mean follow-up of 64 months. The surgical treatment employed in each case is discussed, with emphasis on the use of cement as an adjuvant. This procedure was used in 10 patients, who have been free of recurrence up to the present time.

[Correlation between blood concentrations of E2, P, T, A and HCS in induction of abortion in trimester II and ultrasonic monitoring]. / Correlazione tra le concentrazioni plasmatiche di E2, P, T, H, HCS nell'induzione dell'aborto al ii trimestre e monitoraggio ultrasonico.

PIP: The authors studied plasma HCS, estradiol (E2), progesterone (P), testosterone (T), and androgen (A) changes in 8 cases of therapeutic abortion by intraamniotic injection of prostaglandin F2 alpha (PGF2alpha). During abortion, the mean plasma concentrations of A and T did not change considerably, while mean plasma concentrations of HCS, E2, and P showed a progressive fall correlated to PGF2alpha dosages used to induce abortion. During the induction of abortion, monitoring by ultrasound showed no correlation between fetal movements, fetal distress, and fetal death. (author's modified)^ieng