A pitfall of coronal computed tomographic imaging in evaluation of calcaneal fractures

Computed tomographic (CT) coronal images of the posterior talocalcaneal joint were compared with lateral radiographic views and intraoperative findings in 35 patients with 36 intra-articular calcaneal fractures. The severity of articular incongruity and rotational displacement of the posterior facet fragment were not well appreciated in coronal CT images of nine patients, although Bohler and Gissane angles were significantly decreased in lateral radiographs. This disparity between the radiographic and coronal CT scans can be explained by the intraoperative finding of rotation of the fractured central or lateral portion of the convex posterior calcaneal facet along a horizontal axis in the coronal plane.

An anatomic study of the thickness of the occipital bone. Implications for occipitocervical instrumentation

STUDY DESIGN

The authors measured the thickness and quality of occipital bone regions to determine screw placement during occipitocervical fusion and described the projection of the posterior dural venous sinuses.

OBJECTIVE

This study provides anatomic data relevant to areas of screw placement into the occiput during occipitocervical fixation.

SUMMARY OF BACKGROUND DATA

Few reports exist regarding the morphometrics of the occipital bone and intracranial structures relevant to occipitocervical fusion.

METHOD

The thickness of the posterior inferior occipital bone was measured relative to a 10 x 5 cm grid. Sections were evaluated grossly and histologically. The projections of the posterior dural venous sinuses were determined by direct measurements.

RESULTS

The maximum thickness of the occipital bone, which ranged from 11.5 to 15.1 mm in males and from 9.7 to 12.0 mm in females, was at the level of the external occipital protuberance. The occipital bone was thicker than 8 mm in an area extending laterally from the external occipital protuberance for 23 mm and consisted of dense cortical bone with little or no diploic bone. The projection of most of the torcula on the external surface of the occipital bone was located superior to the center of the external occipital protuberance (mean, 12.6 mm superior and 4.7 mm inferior to external occipital protuberance), whereas that of the transverse sinus was distributed more evenly above and below the external occipital protuberance (mean, 7.3 mm superior and 6.5 mm inferior).

CONCLUSIONS

Screws that are 8-mm long may be inserted in the region of the superior nuchal line (Level 0) extending 2 cm laterally from the center of the external occipital protuberance, 1 cm from the midline at a level 1 cm inferior to the external occipital protuberance (Level 1), and 0.5 cm from the midline at a level 2 cm inferior to the external occipital protuberance (Level 2). The major dural venous sinuses are situated immediately beneath the thickest regions of the occiput and are at risk of penetrative injury during screw placement.

A modified dorsal approach to the wrist for arthrodesis of the non-rheumatoid wrist. An anatomical study

Fourteen cadaveric wrists were dissected to investigate a modified dorsal approach that involved osteotomy of the small and dorsal tubercles without opening the third compartment. This approach could be safely made with good exposure of the dorsum of the wrist. The mean normal angle formed by the extensor pollicis longus tendon at the level of the dorsal tubercle was 144 degrees. An approach that involves division of the third compartment may lead to effective lengthening of the extensor pollicis longus musculotendinous unit by 8 to 17 mm with corresponding decrease in the tension generated by its contraction. The modified approach permits restoration of the normal alignment of the extensor pollicis longus tendon, and may be useful for performing arthrodesis of the non-rheumatoid wrist in young manual workers.

Percutaneous pinning of the proximal humerus

Percutaneous pinning, which has been recommended for unstable, unimpacted two-part fractures of the proximal humerus, requires satisfactory closed reduction and maintenance of reduction with minimum arm movement. Most surgeons usually keep the image intensifier in the anteroposterior (AP) plane and rotate the arm to obtain a second view. This arm movement may render closed reduction and percutaneous pin fixation difficult. A four-step technique that facilitates closed reduction and percutaneous fixation of unstable fractures of the proximal humerus and permits adequate visualization of the proximal humerus in both the AP and axillary planes is presented.

Thoracic spine fractures in patients older than 50 years

The charts and radiographs of 70 patients older than 50 years of age with thoracic vertebral body collapse were reviewed retrospectively. Fifteen patients had traumatic fractures and 34 had osteoporotic collapse of thoracic vertebrae. Metastasis was the underlying disease process in 18 patients and multiple myeloma in the remaining 3 patients. Thirteen patients had fractures involving the upper half of the dorsal spine, of which 8 (61.5%) were metastatic, 4 (30.8%) osteoporotic, and 1 (7.7%) traumatic. All patients with osteoporotic fractures of the upper dorsal spine also had 1 or more fractures of the lower dorsal or lumbar spine. There were 11 metastatic, 80 osteoporotic, 14 traumatic, and 3 fractures secondary to multiple myeloma involving the lower dorsal spine. There were no infections or primary bone tumors. The difference in the frequency of metastatic fractures against other etiologies involving the upper versus the lower thoracic spine was highly statistically significant.

Optimal technique of screw placement in the ischial tuberosity for posterior acetabular fractures

Thirty dry adult bony specimens and eight embalmed cadavers were used to report on the morphological data of the ischial tuberosity and to determine the most optimal technique for ischial tuberosity screw placement for open reduction and internal fixation of posterior acetabular fractures. The average width, height, and depth of the ischial tuberosity were 27.0 mm, 32.2 mm, and 32.4 mm, respectively. The average angles between the posterior and medial aspects and between the posterior and lateral aspects of the ischial tuberosities were 79.5 degrees, and 111.5 degrees, respectively. The risk to the internal pudendal neurovascular bundle increases with either a more medially placed screw or a laterally placed screw that is angled medially. The tendinous origin of the hamstrings becomes quite substantial (7-10 mm thick) at a point 2 cm distal to the inferior acetabular margin. The exposure of the ischial tuberosity should therefore be restricted to this level. The entry point of the screws should be 5 mm or 10 mm medial to the lateral margin of the ischial tuberosity, and the screws should be directed 35-40 degrees, 45-50 degrees, and 50-55 degrees caudally at the level of the inferior acetabular margin and 1 cm and 2 cm below it, respectively, to obtain the most favorable bony purchase.

Incidence, management, and outcome of post-traumatic syringomyelia. In memory of Mr Bernard Williams

OBJECTIVE

To determine the incidence of clinically diagnosable post-traumatic syringomyelia (PTS).

METHODS

A population of 815 consecutive patients with traumatic spinal cord injuries was studied between January 1990 and December 1992.

RESULTS

Reviews of all records, full clinical evaluation, and thorough neurological examination of all patients disclosed 28 patients in whom PTS was confirmed radiologically (3.43%). The incidence of the presenting symptoms, including bladder dysfunction, is described. The level and density of cord lesion was correlated with incidence and it was found that posttraumatic syringomyelia was twice as common in patients with complete injuries than in patients with incomplete injuries. The highest incidence was found in patients with complete dorsal and complete dorsolumbar injuries. The interval between injury and diagnosis ranged from six months to 34 years (mean 8.6 years). This interval was shortest in patients with complete dorsal and incomplete cervical and dorsolumbar cord injuries.

CONCLUSIONS

Reduction of the size of the syrinx seen on postoperative MRI correlated well with a satisfactory clinical outcome in 85% of patients.

Vulnerability of vertebral artery in anterolateral decompression for cervical spondylosis

This study aimed to provide anatomic data for the location of the vertebral artery and offer an optimal approach for lateral cervical decompression that minimizes the risk of injury to the vertebral artery. Anatomically, there has been little study documenting the safe zone to prevent vertebral artery injury during the resection of the uncinate process or uncovertebral joint during the lateral decompression of the nerve root. The transverse foramen and its related parameters were measured on dry cervical spines from C3 to C7. The cadaveric cervical spines were dissected to determine a method for resection of the uncovertebral joint with decreased risk of vertebral artery laceration. The anteroposterior diameters of the transverse foramina gradually decreased from C6 to C3. The transverse diameters of the transverse foramina were smaller at C5. The interforaminal distance, width of the vertebrae, interuncinate distance, and the distance from the lateral tip of the uncinate process to the medial border of the transverse foramen became smaller in more cephalad vertebrae. After subtotal vertebrectomy and opening of the anterior walls of the transverse foramina, the resection of the uncovertebral joint and lateral decompression became easier and safer. Anatomic measurements obtained in this study indicate the vertebral artery to be at risk during decompression of the more cephalad vertebrae. The lateral decompression can be completed under direct vision with smaller rongeurs and curettes, rather than with high speed burr after deroofing the anterior walls of transverse foramina and retracting the vertebral artery laterally.

Lateral condylar fractures of the humerus in children: fixation with partially threaded 4.0-mm AO cancellous screws

Thirty-seven children with fresh, displaced (more than 2 mm in any direction) fractures of the lateral condyle of the humerus were treated by open reduction and internal fixation with a partially threaded 4.0-mm diameter AO lag screw. They were reviewed at a mean follow-up of 4.8 years. Painless, full-elbow movements were obtained in 36 cases. Delayed union, with loss of 10 degrees of elbow motion, was observed in one case (2.72%). Radiologically, less than 4 degrees of varus deviation, compared with the contralateral side, was found in four cases (10.8%). Mild fishtailing was observed in three cases (8.18%). Nonunion, avascular necrosis or clinically significant premature epiphysial fusion was not observed. Elbow function was excellent, irrespective of minor radiologic abnormalities.

Fractures of the distal radius and ulna

Associated fractures of the distal ulnar metaphysis were present in 19 of 320 distal radial fractures requiring either closed manipulation or surgical treatment over a 2-year period. Four morphological patterns of ulnar fracture were encountered, the commonest being the type 1 simple extra-articular fracture of the distal end of ulna with minimal comminution (eight out of 19). 15 patients were treated conservatively and two each were treated by internal and external fixation. 15 patients were reviewed after a mean follow-up of 23.8 months and there were four excellent, five good, five fair clinical results and one poor result. Radiographically the distal radio-ulnar joint (DRUJ) was normal in eight wrists, but longitudinal or horizontal disruption of the DRUJ was present in seven wrists. Fracture callus encroached on the DRUJ in three patients, who also had limitation of forearm rotation. Two comminuted ulnar fractures (type 4) developed non-union, but both patients had full forearm rotation, in contrast to restriction of forearm rotation in four out of five patients with type 1 fractures.

The results of surgical management of displaced tibial plateau fractures in the elderly

We retrospectively reviewed 32 elderly patients (mean age 71.7 years, range 66-83 years) with displaced tibial plateau fractures after a mean of 3.7 years (range 1-7 years) after operative treatment. Schatzker type 2 fracture was the commonest pattern of fracture (60.3 per cent). According to the modified Rasmussen clinical and radiographic criteria, there were nine excellent, 14 good, five fair and four poor results clinically, and 11 excellent, 12 good, six fair and three poor results radiographically. There was no significant correlation between the final radiographic appearance and clinical outcome. Fourteen patients mobilized postoperatively on a continuous passive motion machine followed by a cast brace had a better result than those mobilized in a cast brace alone, but the difference was not statistically significant (P = 0.29). Postoperative complications included deep vein thrombosis in two patients.

Fibrous stabilization of the rheumatoid wrist

19 patients (mean age 59.8 years) underwent fibrous stabilization of the wrist for rheumatoid arthritis. 17 patients were reviewed after a mean follow up of 24.5 months (range 13-40 months). There were four excellent, 11 good, and two poor results according to modified Koka and D'Arcy (1989) criteria. The poor results were due to deep infection in one patient and an unbalanced wrist due to ruptured radial extensors in another. The pre-operative range of wrist movement was an important determinant of the frequency of radio-carpal and/or mid-carpal fusion and the final post-operative range of movement.

Post-traumatic syringomyelia: a review of the literature

The need for increased awareness and a high index of suspicion for post traumatic syringomyelia is emphasised. Early clinical diagnosis confirmed by MRI and early treatment can avert or minimise the potentially devastating effects of post traumatic syringomyelia. The regular and frequent follow up of the patient on a yearly or alternate year basis to monitor the patient with spinal injury for this complication, as well as other complications, is the best way to ensure that post traumatic syringomyelia is diagnosed and managed early in order to avoid further disability.

Ipsilateral Monteggia equivalent injury and distal radial and ulnar fracture in a child

A rare, previously undescribed combination of ipsilateral type III Monteggia equivalent and distal radial and ulnar fracture in a child is reported. A good result was obtained by nonoperative treatment.

Percutaneous pinning for radial neck fractures

Eight patients with angulated radial neck fractures were successfully treated by percutaneous reduction and pinning. The operative technique is simple and is not associated with any important complications. This technique may however not be suitable for radial neck fractures with major translocation.

Hyponatraemia after acute spinal injury

Of 134 patients admitted to the Midlands Centre for Spinal Injuries within 2 days of the spinal injury during 1991-1992, 25 developed hyponatraemia in the acute phase. Hyponatraemia was most common among patients with complete tetraplegia (45 per cent) and these patients tended to be younger as well as have more severe and prolonged hyponatraemia. Overhydration is a common cause of hyponatraemia in this group of patients and should be avoided.

Over-distraction of the radio-carpal and mid-carpal joints following external fixation of comminuted distal radial fractures

Seven patients with Frykman type 7 and 8 distal radial fractures, who had been treated with external fixation, were noted to have significant over-distraction of 5-8 mm in the radio-carpal and mid-carpal joints. One patient, who also had abnormal negative ulnar variance of 2 mm, had a fair result using modified Gartland and Werly (1951) criteria. The remaining six patients had good results, indicating that over-distraction does not significantly alter the final outcome, so long as a normal distal radio-ulnar relationship is maintained.

An open twin incision technique of carpal tunnel decompression with reduced incidence of scar tenderness

We retrospectively compared a single curved incision for carpal tunnel decompression (group A, 29 wrists in 26 patients) with a twin incision technique (group B, 34 wrists in 30 patients), leaving an intact bridge of skin at the base of the palm. Patients in group B reported statistically significant subjective improvement in the early post-operative period, with fewer residual symptoms and earlier recovery of function compared to patients in group A. After a mean post-operative period of 23 months, 5/29 wrists were symptomatic in group A compared to 1/34 wrists in group B at 13 months, but this was not statistically significant. The twin incision technique is easy to perform and allows rapid post-operative recovery. The incidence of scar tenderness is reduced as palmar cutaneous branches of the median nerve are avoided. Because the distal portion of the transverse carpal ligament is divided under direct vision, this technique is not associated with any significant neurovascular complications.

Comminuted femoral shaft fractures treated by closed intramedullary nailing and functional cast bracing

Eighty-one patients with comminuted femoral shaft fractures were treated by closed unlocked Küntscher nailing and functional cast bracing for 1 to 4 weeks postoperatively depending on the degree of comminution. The mean follow-up period was 27.6 months. The average time required for fracture healing was 14 weeks. There was one delayed union. One fracture united with more than 10 degrees of rotational malalignment; shortening of more than 1 cm was present in four cases. Two patients had more than 20 degrees of limitation of hip and knee movement.

Assessment of hip abductor function in relation to peritrochanteric heterotopic ossification after closed femoral nailing

The relationship between peritrochanteric heterotopic ossification and the strength of hip abduction after closed intramedullary nailing for femoral shaft fractures was investigated in 25 patients after a mean follow-up of 2 years (range 9 months to 4 years). The power of hip abduction was assessed and compared with the normal hip. Of the 21 patients with heterotopic ossification, 16 had measurable weakness of hip abduction. Grade III heterotopic ossification resulted in 8-20 per cent weakness of hip abduction, but this was not associated with any disability or symptoms. Clinically important abductor weakness is more likely to be due to ipsilateral fractures or a long nail rather than heterotopic ossification.

Determination of medial epicondylar epiphyseal angle for supracondylar humeral fractures in children

A new radiographic angle, the medial epicondylar epiphyseal (MEE) angle, was studied in 100 anteroposterior (AP) radiographs of normal children aged 3-12 years. The mean value was 38.2 degrees +/- 4.17 degrees (SD) (range 25 degrees-46 degrees), and the MEE angle could be drawn satisfactorily in 96 radiographs. The MEE angle did not vary significantly from this value in 25 Jones' view radiographs (paired t test, t = 0.06). The MEE angle was useful in assessing the accuracy of reduction of 20 supracondylar fractures of the humerus with satisfactory final results.

Flexor to extensor tendon transfer for curly toes. 43 children reviewed after 8 (1-25) years

43 children treated by flexor-to-extensor transfer for a total of 130 curly toes were retrospectively reviewed after a mean period of 8 years. According to an objective scoring system, 37 patients had a satisfactory result and 6 patients had a poor result of one or more toes. We now recommend that children with mild to moderate curly toes should be observed until the age of 6 years, by which time the majority will have had spontaneous correction. The remaining patients should be operated on at that stage because children operated on later had poor results. Attention should be paid to the surgical technique because the long flexor tendons are often bipartite.