Postoperative stability after sagittal split ramus osteotomy with condylar-positioning appliance and screw fixation: asymmetric versus symmetric cases

BACKGROUND AND OBJECTIVE: Myelodysplastic syndrome progenitor cells can be grown and expanded in long term bone marrow liquid cultures in the presence of multiple cytokines. In this study we investigated the pattern of differentiation and response to growth factors in six cases of myelodysplastic syndrome (MDS) with well-defined cytogenetic abnormalities by means of conventional cytogenetics and fluorescence in situ hybridization (FISH). METHODS: Bone marrow cells were grown in stroma-free liquid cultures in the presence of SCF, IL-3, IL-6 and GM-CSF. RESULTS: IN three cases a CFU-GM expansion comparable to normal controls was observed, together with a decrease or increase of cells with abnormal karyotype. Two cases showed no response to growth factor stimulation, morphological signs of terminal myeloid differentiation and increase (one case) or decrease (one case) in the percentage of abnormal FISH signals along the cultures. In one additional case, while CFU-C expansion was present, clearcut leukemic transformation was observed in the culture, together with a sharp decrease in the percentage of abnormal FISH signals, indicating a leukemic transformation of MDS progenitor cells with a normal karyotype. INTERPRETATION AND CONCLUSIONS: Our data indicate that FISH analysis is generally a poor indicator of clonality in MDS; nevertheless, determining the kinetics of cytogenetically abnormal clones in liquid bone marrow cultures may provide insight as to the growth abnormalities of MDS progenitor cells and may be useful prior to in vivo growth factor administration.     

Stability of maxilla downgrafting after rigid or wire fixation

PURPOSE: This article compares the long-term outcomes of rigid internal fixation with wire fixation. PATIENTS AND METHODS: In this retrospective study, nine cases of vertical midface augmentation in which rigid fixation was used were compared with 11 cases with wire fixation. One surgeon completed all cases for the rigid fixation group, and another surgeon completed the cases in the wire fixation group. RESULTS: Follow-up was 16 +/- 11 months for the rigid fixation group and 20 +/- 12 months for the wire fixation group. Inferior movement at the anterior portion of the maxilla was 7.0 +/- 2.9 mm with rigid fixation and 4.5 +/- 3.6 mm with wire fixation (P < .05). Postsurgical superior movement (relapse) was 0.4 +/- 0.4 mm with rigid fixation and 2.4 +/- 2.4 mm with wire fixation (P < .01). Inferior movement at the posterior maxilla was 3.1 +/- 0.2 mm with rigid fixation and 2.8 +/- 2.3 mm with wire fixation. Postsurgical superior movement (relapse) was 0.8 +/- 0.4 mm with rigid fixation and 0.5 +/- 2.3 mm with wire fixation, which was not significantly different. CONCLUSION: This comparison showed downgrafting of the maxilla using autogenous bone harvested from the iliac crest and rigid internal fixation to be a predictable and stable procedure.     

Skeletal stability after mandibular advancement: a comparison of two rigid internal fixation techniques

OBJECTIVE: To compare two different methods of rigid fixation for any difference in postoperative stability after mandibular advancement. MATERIAL AND METHODS: Thirty-eight patients with Class II malocclusion treated by bilateral sagittal split osteotomy (BSSO) and mandibular advancement were selected for this retrospective study. Group A (n = 16) had noncompressive bicortical screws inserted in the gonial area through a transcutaneous approach and Group B (n = 22) had the bone segments fixed with unicortical screws and miniplates on the lateral surface of the mandibular body. Cephalograms were taken preoperatively, 2 days postoperatively, and 6 months after the operation, and a computer program was used to superimpose the three cephalograms and register the advancement and postoperative instability. RESULTS: There was a minimal difference in advancement of the mandible in the two groups. Statistical analysis showed no significant difference in postsurgical stability. However, positive correlation between the amount of advancement and the amount of postsurgical instability was demonstrated using a linear multiple regression test (P = .0002). CONCLUSION: This study indicates that the two different methods of internal rigid fixation of the segments after surgical advancement of the mandible give equal stability postoperatively and their use is a matter of surgical choice.     

Our experience with sagittal split osteotomy for retrognathia

Twenty-six cases which had been operated upon for retrognathia are reviewed. Most of these patients were unmarried, young individuals, and the improvement in their self-image and appearance was the major benefit from the surgical procedure: a lesser number felt the improvement in their bite and function was more important. Relapse, weakness of the lower lip, and numbness of the lower lip were the 3 most common complications. They occurred with sufficient frequency to encourage us to find a surgical approach with less morbidity for this problem of skeletal asymmetry. Perhaps a "C" cut (as champion;ed by Hinds), a forward block of the mandible with cartilage (as described by Trauner), or a vertical cut of the ramus with the posterior fragment notched into the anterior fragment (Mehnert), would yield results with fewer undesirable effects.     

Experimental analysis of functional stability of sagittal split ramus osteotomies secured by miniplates and position screws

PURPOSE: This study determined the relative functional stabilities of various miniplate systems and configurations used to stabilize sagittal split ramus osteotomies (SSROs) and compared them with conventional internal screw fixation. MATERIALS AND METHODS: The biomechanical model was a reproducible prototype of a mandible sagittal osteotomy with consistent material and geometric properties. After advancing the distal segment by 7 mm, each set of mandible analogs (1 set = 3 analogs) was fixed bilaterally by one of three miniplate systems applied in various configurations, and tested with and without a supplemental 2.4-mm bicortical screw applied in the retromolar region. Reduced analogs were placed in a straining frame, and simulated masticatory loads were applied alternatively to the mandibular first molars. Ensuing osteotomy site displacements were measured by transducers attached to a computer-based data acquisition program. A coordinate transformation procedure was used to convert the component displacements captured by the individual transducers into a common "instability factor" to reflect fixation stability for each construct and loading condition. Instability factors for the individual constructs were compared with each other and with those obtained from analogs reduced exclusively with 2.4-mm position screws. RESULTS: Osteotomies stabilized with a combination of miniplates and position screws were more stable than those stabilized exclusively with miniplates (P < .0001). Post-hoc comparisons of mean instability factors (Dunnet's method) showed the miniplate-position screw combinations to be more stable than the 2.4-mm position screw system used as standard (P < .05). Miniplate systems alone were the least stable of the test constructs, with differential rates of failure between the individual miniplate systems. CONCLUSIONS: Exclusive use of miniplate fixation may not provide the consistent stability necessary for early functional restoration after SSROs. The addition of a position screw in the retromolar region substantially enhances the fixation stability of miniplate systems. The use of miniplates with retromolar position screws offers both technical and stability advantages over conventional miniplate or internal screw fixation. The fixation stability of the miniplate-position screw combination is independent of the type of miniplate system used.     

Comparison between the rigidity of bicortical screws and a miniplate for fixation of a mandibular setback after a simulated bilateral sagittal split osteotomy

PURPOSE: This investigation compared the biomechanical stability of three bicortical screws with that of a single four-hole miniplate after 5-mm mandibular setback after a bilateral sagittal split osteotomy (BSSO) in cadaver mandibles. MATERIALS AND METHODS: Thirty human cadaver hemimandibles underwent BSSO followed by two different rigid fixation techniques. All specimens had no third molar, bony pathology, or evidence of mandibular fracture, and there was no history of renal disease or hyperparathyroidism. The specimens were randomly divided into two groups. In group I, three bicortical screws were placed at the superior border, and in group II, one four-hole miniplate was secured on the external oblique ridge with four monocortical screws. The bony height of the mandible was recorded. Maximum resistance load (MRL), the greatest load recorded just before a sudden decrease in load level (bone or fixation failure), was recorded when the mandibles were tested in a compression machine. Multiple regression analysis was used to evaluate the differences in bone height and the MRL between groups I and II. RESULTS: The mean bone height in groups I and II were 28.64 +/- 2.50 mm and 28.72 +/- 4.08 mm, respectively. The mean MRL in group I (20.49 +/- 7.22 kg) was greater than in group II (17.41 +/- 7.81 kg). The multiple regression analysis showed no significant difference in the bone height and the MRL between group I and group II (beta = 2.3492, P = .4114). CONCLUSION: There was no statistically significant difference in stability provided the two techniques.     

Condylar plate fixation of subtrochanteric femoral fractures

We describe our experiences in 40 consecutive patients with subtrochanteric fractures treated with an AO 95 degrees condylar blade plate. Three patients died early due to multiple injuries. One patient developed a delayed union which ultimately resulted in repeated plate fractures due to fatigue. All other fractures heated despite deep postoperative wound infection in three cases. Based on our favourable results, we consider the condylar blade plate fixation of subtrochanteric fractures to be an excellent method, especially if an image intensifier and/or fracture table are not available.     

Treatment of mandibular fractures with rigid osteosynthesis: using the AO system

PURPOSE: This study evaluated the results achieved in the surgical treatment of all mandibular fractures at two university centers using the 2.7 AO mandibular system. PATIENTS AND METHODS: A total of 227 patients presenting with 180 single fractures and 47 with double fractures (274 osteosyntheses) were included in this prospective study. RESULTS: During a mean follow-up of 27.5 months (minimum, 12 months), an overall complication rate of 7% was observed. No infection justified early removal of the osteosynthesis material. CONCLUSIONS: The systematic use of the technique recommended by AO for treating mandibular fractures, performed by thoroughly experienced operators on a compliant population, results in a low rate of complications and an early return to normal function.     

Comparison of different tests assessing neurosensory disturbances after bilateral sagittal split osteotomy

DESIGN: A retrospective review of women undergoing computed tomography (CT) as part of the investigation and management of pathologically proven ovarian cancer in a single specialist gynaecological cancer centre. OBJECTIVE: To ascertain CT appearances and prognostic significance of splenic involvement in ovarian cancer. RESULTS: We found a 10.3% frequency of splenic metastasis in a series of 321 patients with ovarian cancer. Thirty-three women had splenic metastases demonstrated on CT. Twenty-three women had surface lesions with an irregular scalloped shape and broad contact with the splenic surface; 17 of these women had lesions at presentation. Ten women had parenchymal lesions, five at presentation and five at relapse, typically with a rounded shape surrounded by normal splenic tissue. Four out of 10 cases with parenchymal involvement showed lesion progression during chemotherapy. However, lesion progression occurred in only one of 23 cases with surface disease (P < 0.025, Fisher's exact test). In 16 cases with disease involving both spleen and liver, the response to chemotherapy was the same in both organs. CONCLUSION: We have found a higher frequency of splenic metastasis from ovarian cancer during life than previously reported. Parenchymal lesions are significantly less likely to respond to treatment than surface lesions but are more commonly a feature of relapsed disease. We have demonstrated that splenic metastases behave similarly to liver metastases in ovarian cancer. We suggest that the presence of splenic parenchymal metastasis is indicative of FIGO stage IV disease. This finding has implications for proposed cytoreductive surgery.     

Possibilities and limits of intramedullary Kirschner wire osteosynthesis in treatment of metacarpal fractures

Extrasystoles and both supraventricular and ventricular tachycardias may occur as a complication of almost any underlying cardiac disease and many extracardiac causes; on the other hand, also a patient without any detectable structural heart disease may present with these arrhythmias. Refined mapping techniques of the intracardiac conduction process have let to important new informations about the pathophysiology of sustained tachycardias (focal impulse formation, macro-reentry) with practical consequences, for example when ablation of these arrhythmias by radiofrequency catheter ablation is considered. Cardiac arrhythmias may lead to both typical and atypical symptoms. Finally, the patient at risk of sudden cardiac death is characterized. One needs to differentiate patients who have survived a life-threatening event of ventricular tachycardia or have been successfully resuscitated from cardiac arrest (both situations usually need life-long antiarrhythmic interventions for secondary prophylaxis) from patients who also are at high risk, however, are asymptomatic until now. For the latter population, symptoms due to extrasystoles or assessment of the severity of ventricular ectopic beats by the Lown classification are of minor importance; most emphasis in this regard, however, must be placed on the type and severity of underlying cardiac disease.     

Cardiac arrhythmia caused by a Kirschner wire inside the heart. An unusual complication of finger osteosynthesis

A 45-year-old woman with no previous history of cardiac disease woke up one morning with an irregular heartbeat and fatigue. An electrocardiogram showed atrial fibrillation and plain chest radiographs revealed the presence of a metallic pin at the position of the heart. A 24 mm-long metallic pin was removed by open thoracic surgery from within the right ventricle of the heart. Postoperative examination of the pin showed it to be one of the 0.8 mm Kirschner wires that had been used for finger osteosynthesis in her left hand 31 months previously.     

Traditional methods vs rigid internal fixation of mandible fractures

OBJECTIVE: To compare traditional methods (ie, intermaxillary fixation with interosseous wiring or external fixation) with newer techniques (ie, plating, use of lag screws) of open reduction and fixation of mandible fractures. DESIGN: Retrospective analysis of data from medical records. SETTING: Academic urban medical center. PATIENTS: Nonrandomized sample of 356 patients admitted to the hospital for treatment of mandible fractures from 1987 through 1991; 155 patients treated with open reduction and fixation were studied. INTERVENTIONS: Sixty-nine patients were treated with interosseous wire fixation or external fixation, 86 patients with rigid internal fixation. MAIN OUTCOME MEASURES: Presence of infection, nerve impairment, nonunion, malunion, operative time, and follow-up. RESULTS: No significant difference was noted between the two groups for sex, treating service, delay in presentation, antibiotic coverage, mechanism of injury, or type of fracture. The incidence of infection, nerve injury, and unavailability for follow-up were greater in patients treated by the newer techniques. Overall expense and operative time were greater in the group treated with plates and lag screws. CONCLUSIONS: We advocate traditional techniques for patients with mandible fractures requiring open reduction and fixation.     

A retrospective analysis of lingual nerve sensory changes after mandibular bilateral sagittal split osteotomy

PURPOSE: The purpose of this retrospective study was to determine the patient-reported incidence, duration, and perceived deficit in daily activities associated with lingual nerve (LN) sensory changes after bilateral sagittal split osteotomy (BSSO) of the mandible and to compare them with inferior alveolar nerve (IAN) sensory changes in the same study population. MATERIALS AND METHODS: Questionnaires were mailed to 316 patients who had undergone BSSO procedures between 1980 and 1993. The patients were queried for perceived sensory changes in the distribution of the IAN and LN; duration of these sensory changes; and alteration in daily activities caused by these sensory changes. The same questionnaire was mailed to 47 patients who had undergone isolated genioplasty (GP) to control for the normal variance of non-BSSO surgery on perceived LN sensory changes. RESULTS: Forty-three percent of the BSSO patients and 38% of the GP patients returned the questionnaires. Within the BSSO group, 19.4% reported LN sensory changes, of which 69.3% reported that these changes resolved within 1 year; 88% reported altered daily activities. By comparison, 95.5% reported a perceived IAN sensory change, of which 27.3% reported that these changes resolved within 1 year; 57% reported altered daily activities. Within the GP control group, 11% reported LN sensory changes; none of the reported sensory changes lasted longer than 1 month. CONCLUSIONS: A small percentage of patients report LN sensory changes after BSSO. When compared with IAN reported sensory changes, LN sensory changes resolve more frequently and sooner, but they are associated with greater perceived deficits in daily activity. The interpretation of the reported incidence of LN change must be critically reviewed because control subjects also responded positively.     

双电弧集成冷丝复合焊中冷丝位置对焊接过程的影响

搭建了双电弧集成冷丝复合焊接系统,研究了冷丝不同位置对焊接过程的影响机理,其中包括冷丝作用位置对其加热熔化作用及表面成形的影响。实验结果表明:冷丝从两引导焊丝正前方送入时,熔池前端对冷丝的加热熔化作用不充分,冷丝末端会顶触熔池底部,随着冷丝的持续送进和母材的向后移动,某一时刻冷丝回弹,焊丝末端的熔滴弹出落在母材表面形成大颗粒飞溅。当冷丝从侧面送入时,熔池一侧的温度较低,影响熔池金属的流动,导致最终的焊缝成形不对称分布。当冷丝从两引导焊丝正后方送入熔池时,冷丝始终插入熔池中,焊接过程稳定,是理想的冷丝作用位置。此外,随着冷丝送丝速度的增加,两种脉冲电流模式（同相和反相）下,熔敷率均随之增加,且相差不大。同相脉冲电流下电弧对冷丝的加热熔化作用最强烈,反相脉冲电流下次之,直流模式下最弱。      

Small wire external fixation of high energy tibial plateau fractures

Open plate osteosynthesis for high energy tibial plateau fractures with dissociation between the metaphysis and diaphysis has been plagued with frequent soft tissue complications. The Harbor-University of California at Los Angeles Medical Center's experience with small wire external fixation supplemented by limited internal fixation is examined. This alternative method of adequate stable fixation offers the advantage of minimal soft tissue compromise. Twenty-four patients with Schatzker Type VI tibial fractures were treated with small wire external fixation. Supplementary limited internal fixation was used with percutaneous screws in 10 patients and with open reduction in one patient. Sixteen patients had isolated fractures, and eight others suffered multiple injuries. Minimum followup was 12 months. All fractures healed. Complications included one septic knee, two infections at screw sites, and one 10 degrees knee flexion contracture. One knee had Grade 3 radiographic arthrosis, five had Grade 2, 10 had Grade 1, and eight showed no arthrosis. The outcomes (Knee Society clinical rating system) of this study compare favorably with outcomes described in reports published previously for this type of fracture, despite inclusion of eight multiply injured patients. This technique preserves the goals of early range of motion and stable fixation for these devastating injuries, while decreasing the observed major wound complications and nonunion rates. However, longer followup may reveal higher arthrosis rates, specifically in those fractures that were not anatomically reduced.     

A new repositioning system for the proximal segment in sagittal split ramus osteotomy of the mandible

Intrathoracic extra-medullary hematopoiesis is a compensatory mechanism usually seen in thalassemia. The authors report a case with multiple mediastinal localisations fortuitously discovered. CT has allowed diagnosis and led percutaneous biopsy.     

Use of rigid external fixation in fractures of the mandibular condyle

In this article the use of a rigid external fixation system is proposed for the early treatment of condylar fractures. This method offers the advantage of not damaging the articular structures during reduction and allows early mobilization for a rapid recovery. In our Centre 28 patients have been treated with the rigid external fixation system, with good functional results. Of these 15 men and 13 women, 22 had a monocondylar fracture and 6 had a bicondylar fracture. In all the cases there was complete recovery of the occlusal stituation and of the mouth opening; no patient surgically treated with this method has ever presented problems of a local or general nature. The purpose of this report was to evaluate the use of external fixation for the treatment of extracapsular condylar fractures with luxation of the fragment out of the glenoid cavity.     

Condylar chondroma: report of a case

Sixty-two consecutive patients with recurrent traumatic anterior instability of the shoulder were prospectively observed. Thirty patients were observed after arthroscopic stabilization, and 32 were observed after open Bankart repair during a mean follow-up of 36 and 40 months, respectively (range, 24 to 60 months for both groups). To reattach the labrum, the arthroscopic technique used transglenoid sutures and the open technique used bone anchors. Redislocation occurred in two patients (6%) in the open repair group and in five patients (17%) in the arthroscopic repair group. Three of the five patients with redislocations in the arthroscopic repair group underwent reoperation. According to the criteria of Rowe et al., 29 patients (90.6%) who had open repair and 24 patients (80%) who had arthroscopic repair had good-to-excellent results. The patients averaged 90.6 points in the open repair group and 83.1 points in the arthroscopic repair group postoperatively. Little or no limitations in their postoperative sport activities were reported by 30 patients (94%) who underwent open repair and by 25 patients (83%) who had arthroscopic repair. Despite similar patient populations and using arthroscopic examination to select the type of repair in both groups, the results of arthroscopic shoulder stabilization are inferior to those of the classic open Bankart procedure.     

Influence of a rigid plate for internal fixation on the maximum torque capacity of long bones

Submerged mycelia of a strain of Cladosporium werneckii isolated from tinea nigra palmaris, when cultured on enriched corn-meal agar media, developed fruiting bodies resembling perithecia.