Effectiveness of operative treatment of internal orbital wall fracture with polydioxanone implant.

Many implants, some made from teflon or silicone, have been used for internal orbital wall reconstruction. Late complications relating to use of such implants have been reported. In this prospective study a polydioxanone (PDS) implant absorbable in vivo was used for internal orbital wall reconstruction. Follow-up involved clinical examination, magnetic resonance imaging (MRI) and computerized tomography (CT). Clinical examinations were undertaken before operation and up to 36 weeks postoperatively. Sixteen consecutive patients (10 pure blow-out fractures, six with associated zygomatic fracture) took part in the study. Prevalences of diplopia, proptosis and enophthalmus were recorded during each follow-up examination. This study revealed no muscle entrapment within the fracture line. Although CT results confirmed bone growth in the internal orbital wall, shape was unsatisfactory, and orbital volume was not reduced. MRI revealed thick scar formations in six cases (37.5%), fibrotic sinuses filled with air or gas in three cases (19%) and a fibrotic sinus with fluid around the PDS in one case (6%). Our results suggest that use of PDS in reconstructing the internal orbital wall is inadvisable.

The anatomy of the killer whale middle ear (Orcinus orca).

The paper first reviews our present understanding of the functional morphology of the odontocete (toothed whale) ear. The tympano-periotic complex forming the ear region consists of a ventral bowl-shaped tympanic bone in direct contact with the surrounding soft tissues and the incident sound, and a dorsal periotic bone containing the inner ear. Apparently sound brings the tympanic bone, and especially its thin tympanic plate, into vibration. The ossicles in the air-filled middle ear cavity form a bridge from the tympanic plate to the periotic bone connecting the vibrating plate to the oval window and the inner ear. Our computer tomography (CT) sections and camera lucida drawings reveal two hitherto unknown features of the odontocete ear, both of them of potential relevance to sound reception and impedance matching. (1) It is well known that, in addition to the ossicular chain, two other bone structures connect the tympanic to the periotic bone. We show that the most delicate parts of these extra-ossicular connections consist of thin and folded bony sheets which apparently allow compliance in the tympano-periotic bone contacts and enable plate vibration in relation to the periotic bone. (2) The round head of the malleus, in combination with a fitting round depression on the periotic side, seems to form a joint. We propose that this (hypothetical) joint, together with the adjacent structures, forms a lever producing an amplification of the vibration velocity at the level of the oval window.

Lag-screw osteosynthesis of mandibular condyle fractures: a clinical and radiological study.

PURPOSE: This study evaluates the clinical and radiologic results after open reduction and lag-screw osteosynthesis of fractured mandibular condyles. MATERIALS AND METHODS: Eleven adult patients underwent surgery for displaced or dislocated mandibular condyle fractures via a submandibular approach. The repositioned fragments were fixed using lag screws designed by Krenkel or Eckelt. Maxillomandibular fixation was used postoperatively for 2.6 weeks on average (range, 1 to 4 weeks) in nine patients. RESULTS: Slight transient weakness of the mandibular branch of the facial nerve occurred in three cases. Occlusal adjustment was needed in another three cases. Radiologically, the fracture line disappeared at 22.5 weeks on average (range, 8 to 38 weeks). Three screws had to be removed because of loosening. There were signs that the screws had migrated caudally from their original position in seven cases. Twenty-one months on average after operation (range, 8 to 31 months), patients were satisfied with treatment. Clinically, all patients had a stable occlusion and symmetry of the face. All had greater than 5-mm symmetrical lateral jaw excursions. Ten patients had wide (> 40 mm) painless mouth opening. Healing in malposition occurred in four cases and there was considerable shortening of the mandibular ramus in four cases. CONCLUSIONS: Despite good clinical results, lag screws do not meet the needs for rigid internal fixation in the treatment of mandibular condyle fractures.

Blindness after maxillofacial blunt trauma. Evaluation of candidates for optic nerve decompression surgery.

Clinical and computerized tomography (CT) findings in 10 patients with post-traumatic blindness after maxillofacial blunt trauma were evaluated as potential candidates for optic nerve decompression surgery. The total number of blind eyes was 14. All patients suffered from midfacial fractures (isolated zygomatic fracture in 4 and Le Fort fracture in 6 cases) predominantly caused by road traffic accidents. CT scanning and clinical findings allowed location of damage to the optic nerve region in all patients. The most common CT finding was swelling of the optic nerve. Fracture in the optic canal wall was seen in only 3 cases. The clinical situations characteristic of this type of injury make diagnosis and early surgical intervention difficult. It was concluded that two of the 10 patients might have benefitted from optic nerve decompression.

Severe bone resorption and osteoarthrosis after miniplate fixation of high condylar fractures. A clinical and radiologic study of thirteen patients.

Thirteen cases of high condylar fracture treated by open reduction and fixation with miniplates were monitored for an average of 18 months postoperatively. Satisfactory functional results were achieved clinically in all but one patient. Radiologically, however, signs of condylar resorption and osteoarthrosis were diagnosed in all patients. In four patients with associated multiple fractures of the facial bones, rapid complete resorption of the condyle was observed. These changes were markedly more severe than those observed in our previous study, in which osteosynthesis was performed by transosseous wiring and subsequent intermaxillary fixation for 3 to 7 weeks. Indications for rigid and nonrigid fixation in the surgical treatment of condylar fractures are discussed.

Infection after rigid internal fixation of mandibular fractures: a clinical and radiologic study.

Of 214 patients with mandibular fractures treated following the AO/ASIF principle of rigid fixation, 13 patients (6.1%) developed postoperative infection. The yearly percentage decreased remarkably during the study period. When rigid fixation became a routine method, the infection rate was as low as the corresponding figure for cases treated with nonstable techniques and maxillomandibular fixation (MMF). All but one of the infected fractures were in the angular region of the mandible. Teeth had been extracted from the fracture line in 9 of the 10 dentulous patients. It was concluded that erroneous techniques had been used in almost all infected cases, because compression could not be achieved when there was an irregular fracture line, an atrophic edentulous mandible, or inadequate stability due to removal of a tooth in the line of fracture. In five patients, successful reoperation was performed using a reconstruction plate. Detailed radiologic examination was useful in assessment of infection and in follow-up.

Reconstruction of orbital floor with polydioxanone plate.

The use of a polydioxanone (PDS) plate for orbital reconstruction was evaluated in 20 patients with various traumatic defects of the orbital floor. The follow-up time was 9 to 45 months (mean 20.4 months). A CT scan was obtained in 13 patients. Radiographic analysis showed that in 12 of the 13 patients there was new bone in the orbital floor. Clinically, most patients had transitory postoperative diplopia (lasting for a mean of 29 days) because of overcorrection. Only 2 patients, however, suffered from persistent diplopia. In one patient, abducens nerve paresis was the cause. It is concluded that PDS is suitable for orbital floor reconstruction, at least in cases in which defects do not exceed 1-2 cm in diameter. Overcorrection seems necessary. The material is well tolerated, is totally absorbed and appears to be replaced by bone in nearly all cases.

Recurrent thoracic outlet syndrome after first rib resection.

Seventy-seven patients with 84 operated limbs participated in a follow-up examination on an average of about six years after the resection of the first rib for thoracic outlet syndrome (TOS). Forty-two limbs (50%) were totally asymptomatic one month after the operation and remained so for at least half a year postoperatively. In the follow-up examination, 31 limbs were still asymptomatic, whereas 11 limbs had the same symptoms as before the operation. Of the nine patients with recurrent TOS (two with bilateral resection), seven were women and two were men. These nine patients were on average 38 years old (range = 19 to 51 years) and their jobs consisted of monotonous desk work. Seven of 11 stumps of the first rib were subluxated disclosed by the cervical rotation-lateral-flexion test. The occurrence of a subluxated stump of the first rib in the group of asymptomatic patients was far lower, only 3% (p less than .001). Of the 42 patients with persistent problems, a subluxated stump was encountered in seven (17%). Results of this follow-up examination suggest that monotonous desk work is an important factor causing kinesiologic abnormalities in the thoracic aperture. This abnormal kinesiology contributes to the recurrence of TOS symptoms even after the resection of the first rib.

Osteotomy-osteosynthesis in displaced condylar fractures.

Nine male patients were treated for condylar fractures of the mandible by a method involving detachment of the condylar head. Pre-operatively, all patients had severe malocclusion. Radiologically, most condyles were anteromedially displaced. Open reduction was indicated but repositioning of the condyle was impossible without ramus osteotomy followed by temporary condylectomy. On follow-up roughly 32 months after surgery no permanent complications were seen. Joint function was almost completely restored. Radiographic evaluation revealed some shortening and deformation of the condyles which had been operated. Translation and rotation movements were almost normal. The method described appears useful in those rare cases of fractures in which normal repositioning of a dislocated condyle is difficult.

Adaptation of autogenous costochondral grafts used for temporomandibular joint reconstruction: a long-term clinical and radiologic follow-up.

The clinical and radiologic behavior of autogenous costochondral grafts used for temporomandibular joint (TMJ) reconstruction was studied in 16 patients with a mean follow-up of 10 years. The grafts were classified into four groups according to the degree of radiologic calcification or remodeling (adaptation). Total adaptation was observed in six cases and in two cases, no changes were found. The function of the new joint was excellent irrespective of the radiologic status and seemed to improve with time.

Atlantoaxial facet joint arthritis in the rheumatoid cervical spine. A panoramic zonography study.

Twenty-three patients with severe, longterm (22 years, range 8-36) rheumatoid arthritis were evaluated for rheumatoid changes in the atlantoaxial facet joints using a panoramic zonography program. Ten patients had vertical subluxation of the odontoid process. In 9 of 10 cases this mode of subluxation was associated with grade 3-4 arthritis in the facet joints. Our findings indicate atlantoaxial facet joint arthritis with bilateral collapse of the lateral facet joint masses as a cause of vertical subluxation. Furthermore, we suggest that panoramic zonography investigation is a valuable contribution to the pattern of radiographic examination of the atlantoaxial facet joint arthritis, especially for evaluation of its clinical counterparts: nonreducible lateral head tilt and vertical atlantoaxial subluxation.

The effects of clinical data on radiological diagnostic performance in middle-face trauma.

To determine the effect of clinical information on the radiological diagnostic performance in middle-face injury, the medical records and radiographs of 618 patients with middle-face injury were reviewed. The information value of clinical data given in each x-ray requisition was evaluated. The radiological diagnoses were compared with the final clinical diagnoses both retrospectively and prospectively (with and without clinical data). Knowledge of clinical data with statistical significance changed the reader's decision threshold towards improved sensitivity but poorer specificity. Clinical data did not improve the radiologists' performance. Clinical data may be helpful in diagnostic tasks rather by increasing the sensitivity than the specificity.

Computed tomographic myelography (CTM) in atlanto-axial rheumatoid arthritis.

Thirty-two patients with severe cervical rheumatoid arthritis were investigated preoperatively with cervical myelography (CeM) and computed tomographic myelography (CTM). The severity of their clinical symptoms correlated excellently with a combination of the deformation of the spinal cord at the atlanto-axial level, the lateral dislocation of the cord at the same level, and the deformation of the cord at some lower cervical level. Obstructing soft-tissue excrescences seemed to have little significance. No correlation was found in this study between the deformation of the cord and the main findings of the plain films: the atlanto-axial subluxation (AAS), the vertical subluxation (VS), or their combination.

Panoramic zonography in evaluation of recurrent basal cell carcinoma of the face.

Nine patients with recurrent, facial basal cell carcinoma were followed up both clinically and radiographically using a panoramic technique. A cylindrical image track was used for panoramic radiography. Five patients had bony destruction due to tumour re-occurrence, four patients had bony defects caused by surgery. The confirmation of the results by surgery and/or follow-up shows that the spread of basal cell carcinoma into bone can be diagnosed using a panoramic technique.

Panoramic zonography in radiographing the carpus.

The panoramic radiography technique enables the visualization of different image layers. In the search for a method for improving the radiological fracture diagnosis of the carpal bones the suitability of this technique for visualization of the carpal bones was tested. For panoramic zonography, Zonarc (Palomex, Finland) and its programme with cylindrical image layer with 85 mm radius was used. The present study showed that panoramic technique is suitable for discerning the carpal bones but not for demonstrating their skeletal details.

Panoramic zonography in ear radiography.

Thirty ears in 15 patients were examined by plain film radiography and by panoramic zonography with two tracks: A cylindrical concave image layer with 26 mm. radius and a paired sagittal image layer, at 51 mm. distance from midline. The films were interpreted according to the visibility of 23 different anatomic details. On panoramic films the visualization was better in 14 details, equal in 6 and worse in 3 compared to the plain films. The result suggests that panoramic techniques can replace conventional radiography of the ear.

Comparison of the visibility of the anatomical structures of the facial skeleton in panoramic zonography and linear tomography.

The value of cylindrical panoramic radiography (using one rotational axis), a modification of orthopantomography (using three rotational axes), in radiographic examination of maxillo-facial skeleton was estimated by evaluating the visualization of anatomical structures of the facial skeleton on cylindrical panoramic and linear tomographic radiographs of 51 patients examined with both methods. The radiographs were independently reviewed by four radiologists. The visualization of the lateral wall of the orbit and maxillary sinus, nasal septum, alveolar process and zygomatic corpus was better on cylindrical panoramic radiographs. Linear tomography visualized the media wall of orbit better. In visualizing the frontal sinus, orbital floor, medial wall of maxillary sinus and hard palate there were no significant differences between linear tomography and panoramic zonography.

Radiation doses during panoramic zonography, linear tomography and plain film radiography of maxillo-facial skeleton. A comparative study.

The radiation doses to the organs and the skin of the head and neck during plain film radiography, a-p and p-a linear tomography and panoramic zonography of the maxillo-facial skeleton were measured on a sliced anatomic Alderson skull phantom with LiF (TLD-100) thermoluminescence chips. The doses were clearly highest during the linear tomography. Also the doses during the plain film radiography were quite high. Compared to the conventional methods the doses from the panoramic Zonography were minimal.

Operative treatment of severe proximal humeral fractures.

Results after the operative treatment of 41 severe proximal fractures of the humerus are reported. The fractures were classified according to Neer (1970a). The aim of treatment was accurate reduction and stable fixation of the fracture with screws or with screws and a plate. When scored according to Neer's (1970a) functional assessment, results in the 31 patients re-examined more than 1 year postoperatively were excellent or satisfactory in 23 patients. Results were excellent or satisfactory in 14/15 patients with type III fractures, in 7/11 with IV, and 2/4 with type VI. In the only re-examined patient with a type V fracture the result was unsatisfactory. The most common technical error was a too high positioning of the AO plate and persistent varus deformation of the head of the humerus. High positioning of the plate caused post-operative restriction in the movements of the glenohumeral joint because the implant impinged under the acromion during abduction. No aseptic necrosis of the humeral head was observed. Of the patients of working age all but one returned to their preoperative occupations within a mean of 3.5 months after surgery.

Surgical treatment of acromioclavicular dislocation: a review of 39 patients.

Results after the operative treatment of 39 total (Type III) acromioclavicular (AC) dislocations are reported. The operation consisted of suture of the acromioclavicular and coracoclavicular ligaments and transfixion of the AC joint with an AO/ASIF malleolar screw passed through the acromion into the lateral end of the clavicle. The screw was removed at an average of six weeks after the operation. In 36 patients re-examined after a mean of 4 years, the overall results were good in 92 per cent of cases. The range of flexion and abduction was excellent (over 170 degrees) in 90 per cent. Stress radiographs revealed persisting subluxation of the AC joint in 6 patients and persisting dislocation in 1. Signs of osteoarthrosis were seen in 4 patients and signs of osteolysis in 12. Radiological signs of osteolysis correlated well with incongruity of the AC joint but not with the clinical function. Radiological signs of osteoarthrosis in the AC joint, however, correlated with a poor clinical result: all patients with a fair or poor clinical result had signs of osteoarthrosis in the AC joint. Except for one, all patients returned to their preoperative occupations within an average of two months.