The anterior cruciate ligament was replaced in rabbits, using implants of carbon or polyester filaments with known mechanical properties. The biocompatibility of the implants was assessed in detail using light microscopy, and scanning and transmission electron microscopy. Mechanical tests were made of stability, in comparison with normal joints and controls after excision of the ligament. Some carbon fibre implants broke down in vivo, allowing instability; the fragments caused chronic inflammation. Intact carbon implants did not induce the formation of neoligaments; they were covered by tissue, but there was no ingrowth. Polyester did not degrade mechanically and supported early collagenous ingrowth within the implant, even in the mid-joint space. It was concluded that there was no justification for the use of carbon fibres as anterior cruciate replacements; polyester appeared to be suitable.
The calcaneal tendons of rabbits were excised and either replaced with a carbon or polyester fibre implant, or left as controls. The strength of the neotendons and their mode of failure under tension were examined at intervals up to six months after operation. Return to near normal strength took six months to develop, suggesting that patients having ligament or tendon reconstructions should not resume normal activity for several months. Carbon fibre-based neotendons showed progressive elongation which, unless avoided by a sufficient period of immobilisation, would affect the functional result.
We present three cases of a previously undescribed condition characterised by unilateral tibia vara associated with an area of focal fibrocartilaginous dysplasia in the medial aspect of the proximal tibia. The three children affected were aged 9, 15 and 27 months respectively. Two required tibial osteotomy, but in one the deformity resolved without treatment. The pathogenesis of the focal lesion remains conjectural; the most likely explanation is that the mesenchymal anlage of the tibial metaphysis has, for unknown reasons, developed abnormally at the insertion of the pes anserinus.
Carbon-fibre and polyester-fibre implants of comparable dimensions were used to replace the calcaneal tendon in 30 sheep. The neotendon produced in proximity to the polyester fibres was denser, more collagenous and more closely adherent than that in the carbon-based neotendon. Fragmentation of the carbon caused continuing cellular reaction which was associated with a poor collagen response.
The features of congenital elevation of the scapula are described for a group of 16 children. Fibrous bands which tether the scapula and limit its movements were discovered in most children. Vertical displacement osteotomy of the medial border of the scapula and division of the fibrous attachments have provided a reliable and safe treatment for 12 children during the past 10 years.
An elderly woman presented with a pathological fracture of the right humerus. Progressive dissolution of the shaft of this bone took place over six months. No cause could be established and the patient refused biopsy. With only simple splintage for treatment the humeral shaft gradually reformed and re-ossified over a period of two years. The patient has been under review for four and a half years and no further pathology has come to light. The cause of the osteolysis remains obscure.
An unusual case of median nerve compression within the carpal tunnel ascribed to thrombosis in a dilated artery is described.
1. A study of fifty patients with dislocations of the lunate bone or perilunar dislocations has been made. The period of observation was adequate in thirty-eight. 2. The injuries generally occur in young or middle-aged men after unusually severe trauma. 3. Associated injuries are frequent, and the most common of these is damage to the median nerve. 4. In one-third of the cases the nature of the lesion was not initially diagnosed or the initial treatment was inadequate. 5. A dislocated lunate bone may be replaced even at a late stage and even if the displacement is severe so long as there is some soft-tissue attachment. The anterior approach may safely be used for the replacement. 6. The lunate bone may be removed without involving the necessity for arthrodesis of the wrist. 7. Open reduction should be employed for trans-scaphoid dislocations whenever exact realignment and good fixation cannot be achieved by closed methods. 8. Excision of the proximal row of the carpus gives the possibility of salvage of a reasonable degree of function, and may be preferable to arthrodesis or removal of only part of the proximal row.
1. Nine cases of disturbance of the relationship between the scaphoid and the radius and between the scaphoid and the lunate bones are described. 2. Persistent dislocation of the scaphoid bone may follow reduction of perilunar dislocations or of other dislocations of the proximal row of the carpus. It may be obvious, as in waist-deep dislocation, or may be solely a rotational dislocation which may be difficult to diagnose. 3. Uncorrected rotational dislocation of the scaphoid bone caused significant disability in six of seven cases. 4. Aids to the diagnosis of this condition are described and a vigorous approach to the problem of correction is advocated. 5. The experience of other workers in this field is reviewed and discussed.
Conclusions based on forty-six osteotomies show this to be a sound pain-relieving operation for osteoarthritis of the hip. The field of operation has been widened and some of the disadvantages have been avoided by nail and plate fixation. Early results from this method are similar to those from osteotomy and immobilisation in plaster, and it seems likely that the relief of pain will be just as enduring.
