P. D. Marshall

Avoiding nerve damage during elbow arthroscopy

To define the anatomical relationships of the nerves to the common arthroscopy portals at the elbow an arthroscope was introduced into 20 cadaver elbows and the positions of the nerves were then determined by dissection. In all cases the posterior interosseous nerve lay close to the radiohumeral joint and to the anterolateral portal. Pronation of the forearm displaced the nerve away from the arthroscope. The median nerve passed consistently within 14 mm of the arthroscope when it was introduced through the anteromedial portal. The branches supplying the superficial forearm flexor muscles were at risk.

A safe, reliable method of carpal tunnel injection

The injection of steroid preparations into the carpal canal is a recognized practice in the management of carpal tunnel syndrome. This procedure is associated with a risk of temporary or permanent damage to the median nerve. We present a new method of carpal tunnel injection based on anatomic dissections. We have used this technique successfully for more than 10 years, and there have been no cases of median nerve injury.

Spontaneous Fractures in a Patient Treated with Low Doses of Etidronic Acid (Disodium Etidronate)

SummaryThe recommended regimen of etidronic acid (disodium etidronate) for the treatment of Paget’s disease of bone is 5mg/kg/day for a period of less than 6 months. There have, however, been reports of impaired mineralisation of bone and concern that the risk of fracture is increased with this dosage. We report a patient with Paget’s disease in whom fractures occurred through pagetic and non-pagetic bone which appeared to be causally related to treatment with low doses of etidronic acid. The osteomalacia resolved when etidronic acid was discontinued.

SURGICAL RELEASE OF KNEE FLEXION CONTRACTURES IN MYELOMENINGOCELE

We report the results of a prospective study of the surgical release of 45 knee flexion contractures in 28 patients with myelomeningocele. The neurosegmental level was thoracic in ten patients, L1/2 in one, L3/4 in 11, and L5/S1 in six. In walkers the indication for surgery was a fixed flexion contracture impeding walking, and in non-walking patients it was a flexion contracture impeding transfers or sitting balance, or likely to do so with increasing deformity. The mean age at surgery was 6.4 years (3 to 21) and the mean period of follow-up 13 years (4 to 20). The mean knee flexion contracture before surgery was 39 (25 to 70) which improved to 5 degrees at maximum correction and to 13 degrees at latest follow-up. We conclude that surgical release of knee flexion contractures in myelomeningocele improves gait in all children who walk, particularly those with low lumbar lesions. Recurrence of knee flexion contractures after surgical release is most common in those with thoracic lesions who do not achieve independent walking.

Surgical release of knee flexion contractures in myelomeningocele

We report the results of a prospective study of the surgical release of 45 knee flexion contractures in 28 patients with myelomeningocele. The neurosegmental level was thoracic in ten patients, L1/2 in one, L3/4 in 11, and L5/S1 in six. In walkers the indication for surgery was a fixed flexion contracture impeding walking, and in non-walking patients it was a flexion contracture impeding transfers or sitting balance, or likely to do so with increasing deformity. The mean age at surgery was 6.4 years (3 to 21) and the mean period of follow-up 13 years (4 to 20). The mean knee flexion contracture before surgery was 39 (25 to 70) which improved to 5 degrees at maximum correction and to 13 degrees at latest follow-up. We conclude that surgical release of knee flexion contractures in myelomeningocele improves gait in all children who walk, particularly those with low lumbar lesions. Recurrence of knee flexion contractures after surgical release is most common in those with thoracic lesions who do not achieve independent walking.

Laboratory comparison of the cannulated Herbert bone screw with ASIF cancellous lag screws

The compression produced by and the resistance to pullout of the 6.5 mm cannulated Herbert screw were compared with those of ASIF headed screws. The latter were tested with and without washers and in the following sizes: 4.5 mm cortical, 6.5 mm cancellous with a 16 mm threaded segment, and 6.5 mm cancellous with a 32 mm threaded segment. Polyurethane foam was used as a substitute for cancellous bone and ASIF artificial bone for corticocancellous bone. The compression produced by a cancellous lag screw with a washer was significantly greater than that produced by a Herbert screw of equivalent size (p < 0.05). When the screws were tested using the corticocancellous composite the ASIF cancellous screw without a washer produced significantly greater compression (p < 0.05); when used with a washer the difference was highly significant (p < 0.001). The dual pitch Herbert screw is not appropriate for the management of fractures in which compression is of greater importance than the need to avoid prominence of the screw head.

Below knee cast stresses and intra-cast pressures during normal walking

Twenty-one tests on 13 volunteer subjects were used to quantify cast stresses and intra-cast pressures in below knee casts during normal walking. A microcomputer and force plate system were used to study the gait with various cast configurations. It was found that stresses were high where expected but also in less obvious locations, i.e. anterior and posterior aspects of the upper part of the cast. The data suggest that, irrespective of the design of the cast (as long as it is well fitting), control of rotation will be sufficient. This also validates the use of an articulating ankle component in most situations, although this type of cast provides less rotation control. If a fixed ankle is used then the casting material should be concentrated around the junction of foot and shank cylinders and less on the shank (only sufficient to provide rigidity). Comparison of different materials indicates that use of modern casting materials requires more emphasis on splint construction details than when using conventional plaster of Paris.

Should the government be running job centres

Most people find their jobs by means other than job centres. Since they are not a monopoly, what reason is there for government to run them? Can it even tell whether they are being run efficiently?