An assessment of filamentous carbon fibre for the treatment of tendon injury in the horse

The results of an assessment of carbon fibre for biological use are given, with particular reference to the clinical use of the material in the treatment of equine tendon injury. Biocompatability of the fibres is assessed using fibroblast cell cultures and replacement of normal tendon with carbon fibre prostheses in experimental animals. The rationale and technique for using this material in clinical cases of tendon injury in the racehorse are described. Results are given from 62 implant operations in a limited series of 40 horses.

The use of flexible carbon fibre in the repair of experimental large abdominal incisional hernias

Ventral hernia was induced surgically in sheep and either left unrepaired (5 animals), repaired with plastic mesh (20 animals) or with carbon fibre (20 animals). In unrepaired animals the hernia persisted. Three hernias recurred in the group repaired with plastic mesh, 2 as a consequence of sepsis. All the hernias repaired with carbon fibre remained sound over periods varying from 8 months to 2 years. There was a gradual invasion of the carbon fibres by collagenous tissue and thus a transition from one to the other of the stress of maintaining the abdominal wall intact.

The operative treatment of sacro-iliac subluxation and disruption of the symphysis pubis

A method of internal fixation of the disrupted symphysis publis is discribed which uses readily available AO plates and tools. Patients can be mobilized at 3 days and discharged within 2 weeks. This method of treatment represents a considerable saving in nursing time and a great improvement for the patient, who is usually free from pain after 1 week.

The repair of cruciate ligaments with flexible carbon fibre. A longer term study of the induction of new ligaments and of the fate of the implanted carbon

Carbon fibre appears to induce the formation of tendon in both animals and humans. Experiments have been conducted in sheep in which new anterior cruciate ligaments have been induced in response to the implantation of filamentous carbon fibre. Long-term studies indicate that the carbon fibre slowly breaks up at the site of implantation and later begins to appear in the regional lymph nodes.

Toxicity and residue studies in dairy animals with firemaster FF-1 (polybrominated biphenyls)

Two studies (one in Holstein calves and one in Holstein cows) were conducted to determine potential toxicity and residue levels following oral ingestion of polybrominated biphenyls (PBB). The material was FireMaster FF-1. Administration was by gelatin capsules. Doses in calves were 0.1, 1.0, 10, or 100 mg/kg body weight, while doses in cows were equivalent to 0.01, 0.1, 1.0, or 10 ppm in the diet. The calves were sacrificed after 2, 4, 6, or 12 weeks. The cows were fed 158 or 228 days, and were then in a recovery period for 182 or 112 days. In the calf study, signs of toxicity were observed only in animals fed 100 mg/kg-day. Administration of 10 mg/kg-day or less for up to 12 weeks caused no overt signs of toxicity. Histologic studies were conducted upon selected organs and tissues taken at time of sacrifice. The only treatment-induced lesions among animals fed 0.1 mg/kg-day were minimal lesions in the kidney and skin in the one calf fed at this level for 12 weeks. Treatment-induced lesions were present in the kidneys, skin, and/or liver from some animals fed levels of 1.0 mg/kg-day and above. The relative severity of these lesions was related to the level and length of exposure. Treatment-associated changes were observed in the testes of all males in this study. The hypospermatogenesis observed was consistent with the age of the animals due to prepuberal development of the testes. No clinical signs of toxicity or histologic changes attributed to PBB were observed in the cows. Two cows were pregnant at the initiation of the study and give birth to normal, healthy calves during the study. These calves grew normally and appeared healthy when sacrificed at about 6 months of age. Residue levels were quantitated as the hexabromobiphenyl isomer (BP-6) which is the major isomer present in the PBB mixture. Tissue residue levels in calves increased with dose and duration of administration of PBB with highest levels being found in the fat. At 100 mg/kg the levels in fat were about 6000 to 6300 ppm after 6 to 12 weeks. Residue levels of BP-6 in milk and fat of the cows also increased with dose and duration of administration. Maximum levels in milk were about 1/3 the levels in the diet. In general, the levels plateaued after about 4 to 6 weeks and did not go appreciably higher even though administration of the FireMaster FF-1 was continued. Maximum levels in fat were on the order of approximately 4.5 times the levels in the diet, except at the lowest dose level. Residues decreased in milk after administration of PBB was discontinued, but detectable levels were still present 6 months later. Residues were found in the calves born of treated cows indicating passage of the PBBs through the placental barrier and/or ingestion through the milk.

Biological reaction to carbon fiber implants: the formation and structure of a carbon-induced "neotendon"

In 43 young rabbits, the tendo Achilles and flexor digitorum longus tendon were excised and replaced by filamentous carbon fiber. Tendo-Achilles in controls was repaired by silk or nylon sutures or left without replacement. Concurrent excision of the posterior tibial nerve was performed in one group of the carbon-replacing tendo-Achilles operations. When fully functioning, carbon-induced "neotendon" rapidly developed from young fibroblastic tissue outgrowths of the loose mesenchymal tissue of the perineurium and adventitia of the blood vessels in the adjacent neurovascular bundle. Silk or nylon replacement of the excised Achilles tendon did not lead to successful production of a new substitute. Carbon fibers were unsatisfactory for replacement implants for the flexor digitorum longus tendons.

Potentially fatal asphyxia following a minor injury of the cervical spine

The case is reported of an elderly man with asymptomatic cervical spondylosis who sustained a minor hyperextension injury of the cervical spine when the brakes of a car were applied suddenly to avoid a collision. Within six hours marked swelling of the neck and severe dyspnoea developed, and a lateral radiograph showed the pharyngeal shadow displaced far forwards and a crack fracture of an anterior osteophyte. Tracheostomy and evacuation of a massive prevertebral haematoma were performed, with immediate relief. The case draws attention to the possibility of this serious complication of a "whiplash" type of injury.

Induction of tendon and ligament formation by carbon implants

Experiments have been performed on rabbits and sheep which demonstrate that pure carbon, in a flexible and filamentous form of great strength, can be used successfully to induce the formation of new tendons. A concept fundamentally different from that underlying the use of other artificial tendon replacements is involved, in which rapidly developing tendon-like tissue is induced to form around the implant. This gradually takes over the function of the implant. The early results in rabbits and the late results in sheep suggest that filamentous carbon may have a place in the replacement of the calcaneal tendon and the collateral ligaments of the knee.

A comparison of operative cholangiographic technique

The accuracy and postoperative morbidity of cannulation of the cystic duct in routine operative cholangiography were compared with those of needle puncture of the common bile duct. The results are comparable and a case is made for the simpler procedure of needle puncture of the common duct.

Stimulation of bone growth by periosteal stripping. A clinical study

Periosteal stripping in the long lower limb bones of thirty children with shortening after poliomyelitis was performed. All have been followed up for five years. A relative increase in length attributable to the periosteal stripping procedure was seen in the majority. The conclusions are that this simple procedure is indicated in minor degrees of limb inequality in growing children, but that the haphazare response precludes any accurate estimation of the final outcome of such a procedure.

Stablization of the spine in the surgical treatment of severe spinal tuberculosis in children

This is a 5- to 10-year survey of 160 children, all with severe surgically-treated spinal tuberculosis. The treatment consisted of: anterior spinal fusion alone, anterior with posterior fusion, posterior fusion alone and posterior with anterior fusion. The results indicate that in the less severe cases, where an abscess is not evident on plain radiographs, psoterior fusion alone can be of value in the growing spine. In severe cases, especially where an abscess is seen, the combined approaches give the best results. The risk of posterior fusion alone is an unsatisfactory, long term neurological outcome in too many patients. The combined procedure of anterior fusion with posterior fusion is the treatment of choice for all immature spines with this disease.

A hypothesis on some factors governing the behaviour of short segments of the small bowel

A hypothesis is advanced in which it is argued that variations in the extrinsic autonomic innervation of short small-bowel segments are responsible for the unpredictable behaviour of such segments. Experimental evidence is offered to substantiate the hypothesis.

Extensive cervical laminectomy. Long-term results

It has been possible to follow up 5 patients who underwent complete cervical laminectomy for cervical spondylotic myelopathy between 12 and 17 years ago. The operation was described by Rogers in 1961. Clinical examination findings, together with the radiological appearances, indicate that this procedure does not predispose to instability of the cervical spine. This relatively simple procedure achieved long-lasting improvement in the patients examined.

Proximal jejunal and distal ileal extrinsic innervation in the rabbit and dog

The varying patterns of motor behaviour of isolated and interposed jejunal and ileal segments in the rabbit and the dog previously reported (Jenkins and Macleod, 1970) were examined by selective denervation techniques. One hundred and twenty-three paired experiments were conducted on rabbits and 55 similar experiments were performed on dogs.

Length-matched paired segments of proximal jejunum and distal ileum were isolated and filled with saline at a constant rate. Segmental resistance to filling was regarded as an index of tone. The influence of vagotomy and of sympathectomy on the tone of the segments was studied in segments supplied by one or by two vessels.

Vagotomy caused a decrease in tone in the proximal jejunal segments, while sympathectomy had little effect. In segments of distal ileum sympathectomy resulted in segments behaving in a similar fashion, while vagotomy had an unpredictable effect on tone.

The results suggest a uniform distribution of the vagus to the whole length of the small bowel in the rabit and the dog, serving to maintain the tone of the bowel. It is deduced that sympathetic supply to the proximal jejunum isabsent in these animkals and is distributed to the distal ileum only in an irregular fashion.

The relevance of these observations to the clinical use of interposed small-bowel segments is considered.

A case of carcinoma of the colon in association with neurofibromatosis

A case is presented of neurofibromatosis of the large bowel associated with a primary adenocarcinoma of the colon. This is believed to be the first report of such an association.

Omental reinforcement of intestinal anastomoses. An experimental study in the rabbit

A series of end-to-end everting colonic anastomoses were performed in 95 rabbits in order to assess the value of omental reinforcement. The animals were divided into three groups: (a) control animals, (b) animals with anastomoses reinforced by a free omental graft, and (c) animals with anastomoses reinforced by an omental pedicle. Reinforcement with a free omental graft carried a prohibitive increase in mortality. The use of an omental pedicle appeared to strengthen the anastomosis against forced disruption in the immediate postoperative period but it did not improve the survival rates and it may carry long-term dangers. The explanation for these findings is discussed. It is our view that there is no place for omental reinforcement in colonic surgery.

Irritable hip in the adult

Images