Aims

The aim of this study was to evaluate near-infrared spectroscopy (NIRS) as a continuous, non-invasive monitor for acute compartment syndrome (ACS).

Objectives

To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model.

Aims

Patellofemoral problems are a common complication of total knee arthroplasty. A high compressive force across the patellofemoral joint may affect patient-reported outcome. However, the relationship between patient-reported outcome and the intraoperative patellofemoral contact force has not been investigated. The purpose of this study was to determine whether or not a high intraoperative patellofemoral compressive force affects patient-reported outcome.

Objectives

Patient-specific (PS) implantation surgical technology has been introduced in recent years and a gradual increase in the associated number of surgical cases has been observed. PS technology uses a patient’s own geometry in designing a medical device to provide minimal bone resection with improvement in the prosthetic bone coverage. However, whether PS unicompartmental knee arthroplasty (UKA) provides a better biomechanical effect than standard off-the-shelf prostheses for UKA has not yet been determined, and still remains controversial in both biomechanical and clinical fields. Therefore, the aim of this study was to compare the biomechanical effect between PS and standard off-the-shelf prostheses for UKA.

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30mW/cm. 2. ) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis

1. The healing of the radius and tibia in dogs after compression plating of osteotomies made by a Gigli saw was studied. 2. The methods used were indian ink microangiography and terramycin labelling. The Spalteholz technique and azane colouring were used. 3. Revascularisaton of the fracture region took place both from newly formed vessels in the Haversian systems and from periosteal and endosteal vessels. 4. The fracture gap was filled at an early stage by a vascular network. Under stable conditions direct angiogenic bone formation took place around this network. 5. Rebuilding of the cortical bone in the fracture region occurred by osteoclastic activity. Groups of osteoclasts made cavities in the necrotic bone and were immediately followed by loops of vessels; behind and around the loop new bone was formed. Another form of bone absorption consisted of bundles of vessels which eroded necrotic cortical bone without new bone formation. 6. The new bone was initially oriented along the fracture gap but, by conversion into secondary osteones, it became progressively oriented longitudinally in the direction of the original bone. 7. Under stable conditions some periosteal and endosteal callus formation occurred though it was of slight importance. It regressed very soon and was seldom seen in the radiographs

1. Although fractures and dislocations of the talus have been described since 1608 the rarity of the more severe and complicated injuries has meant a dearth of accurate descriptions or classification in the literature. 2. A series of 228 injuries of the talus occurring in members of the Royal Air Force between 1940 and 1943 has been reviewed. 3. A simple but comprehensive classification of injuries of the talus is presented, together with a review of the pathological anatomy, clinical features, and methods of treatment. The importance of distinguishing between fractures and fracture-dislocations, and of watching carefully for displacements of the subtalar joint, is emphasised. 4. The important complications—infection, avascular necrosis and traumatic arthritis of the ankle or subtalar joint—are discussed. Infection may be the result of a compound injury, or may follow sloughing of the skin stretched over a displaced talus. Early reduction is, therefore, of great urgency in closed injuries. Avascular necrosis of the talus occurs in gross injuries when all or most of the soft-tissue attachments to the bone are severed. Revascularisation and regeneration will take place with patient conservative treatment. 5. The mechanism of injury is discussed. 6. The results of excision of the talus are poor. Every effort should be made to preserve the body of the talus, but if its loss is inevitable a useful foot can be regained by deliberate fusion of the tibia to the calcaneum

We have evaluated prospectively the arthroscopic findings in acute fractures of the ankle in 288 consecutive patients (148 men and 140 women) with a mean age of 45.6 years. According to the AO-Danis-Weber classification there were 14 type-A fractures, 198 type B and 76 type C. Lesions of the cartilage were found in 228 ankles (79.2%), more often on the talus (69.4%) than on the distal tibia (45.8%), the fibula (45.1%), or the medial malleolus (41.3%). There were more lesions in men than in women and in general they were more severe in men (p < 0.05). They also tended to be worse in patients under 30 years and in those over 60 years of age. The frequency and severity of the lesions increased from type-B to type-C fractures (p < 0.05). Within each type of fracture the lesions increased from subgroups 1 to 3 (p < 0.05). The anterior tibiofibular ligament was injured with increased frequency from type-B.1 to type-C.3 fractures (p < 0.05), but it was not torn in all cases. While lateral ligamentous injuries were seen more often in type-B than in type-C fractures (p < 0.05), no difference was noted in the frequency of deltoid ligamentous lesions. Our findings show that arthroscopy is useful in identifying associated intra-articular lesions in acute fractures of the ankle

Severe open fractures of the tibia have a high incidence of complications and a poor outcome. The most usual method of stabilisation is by external fixation, but the advent of small diameter locking intramedullary nails has introduced a new option. We report the early results of a randomised, prospective study comparing external fixation with non-reamed locked nails in grade-IIIb open tibial fractures. Of 29 patients, 15 were treated by nails and 14 by external fixation. Both groups had the same initial management, soft-tissue procedures, and early bone grafting. All 29 fractures healed within nine months, but the nailed group had slightly better motion and less final angulation. Complications included one deep infection and two pin-track infections in the external fixator group and one deep infection and one vascular problem in the nailed group. Although the differences in healing and range of motion were not statistically significant, we found that the nailed fractures were consistently easier to manage, especially in terms of soft-tissue procedures and bone grafting. It is the treatment preferred by patients and does not require the same high level of patient compliance as external fixation. The only factors against nailing are the longer operating time and the greater need for fluoroscopy. We consider that locked non-reamed nailing is the treatment of choice for grade-IIIb open tibial fractures

Aims

To investigate the risk factors for progression of articular cartilage damage after anatomical anterior cruciate ligament (ACL) reconstruction.

Dynamic muscle-tendon substitution for acute anterior cruciate deficiency in the dog was studied using the semimembranosus muscle-tendon. Nineteen mongrel dogs each had a semimembranosus transfer in one knee; as a control, the anterior cruciate ligament and the semimembranosus were released in the opposite knee. No postoperative immobilisation was used. The anterior drawer sign was assessed before and after operation and when the dogs were killed five months later. Dogs were excluded from the study if they developed infections or contractures of the hind legs. At five months, 11 dogs were available for study. The operated knees were examined histologically and evaluated using a reproducible index of arthritis based on: the macroscopic discoloration of the articular cartilage, the cellularity of the cartilage, the microscopic appearance of the articular surface, the loss of proteoglycans, the formation of osteophytes and the degree of subchondral osteosclerosis. There was no significant difference in the anterior drawer sign or the degree of arthritic changes between knees with a semimembranous transfer and the controls. Examination showed that a muscle-tendon transfer into the tibia was equivalent to transferring the muscle into the posterior capsule--the intra-articular tendon being weak but histologically viable. The transfer did not prevent the anterior drawer sign becoming positive nor the development of osteoarthritis. A second control group, in which three dogs had an arthrotomy and semimembranosus release in both their hind legs, showed that a semimembranosus release alone did not cause osteoarthritis

Aims

The aim of this study was to estimate economic outcomes associated with deep surgical site infection (SSI) in patients with an open fracture of the lower limb.

Over an eight-year period up to 1983, a total of 322 consecutive patients had operations for ankle fractures; 176 were Weber type B and 128 type C. We were able to review 230 of these patients after a mean follow-up of six years (1 to 11) including 128 with Weber B and 102 with Weber C fractures. We used an ankle score which combined symptoms and clinical and radiological findings, with a maximum score of 100 points. The mean score for all 230 was 92 (68 to 100). Fifteen of these patients had developed a distal synostosis between the tibia and fibula, three after a Weber B and 12 after a Weber C fracture. In 13 of these 15 ankles the synostosis had been visible radiologically within three months of the operation. In the other two there had been radiologically visible calcification at the three-month follow-up. In 1993, we were able to review nine of the 15 patients with synostosis using the same scoring system. At a mean follow-up of 14 years (12 to 18) the mean score for those with synostosis was 91 (71 to 100), much the same as this group’s previous score and the mean score of the whole group of operated patients. We conclude that distal tibiofibular synostosis after ankle fracture usually causes few symptoms and does not generally require any treatment

From 1986 to 1991 we fitted 20 children with endoprostheses after resection of malignant bone tumours of the leg; six have reached skeletal maturity and are the subject of this study. Reconstruction of defects in growing limbs in which the eventual shortening can be predicted requires the use of extendable prostheses. The mean age at operation was 11 years (9.2 to 13.7) and the average follow-up period was 6.3 years (4.3 to 7.6). The diagnosis was osteosarcoma in five patients and Ewing's sarcoma in one. All tumours were Enneking stage-IIB. When seen for follow-up all patients were free from disease. The extendable implants used included the Pafford-Lewis prosthesis and the Kotz Modular Femur Tibia Reconstruction system with a compatible, newly-designed growth module. Telescope-like elongation of the prostheses was performed by insertion of a screwdriver through a small skin incision. Active epiphyseal growth in the adjacent growth plate was preserved by using prosthetic stems with a smooth surface. The mean length gained was 13.15 cm (4.5 to 19.5) requiring 53 planned procedures. Seven revision operations were necessary for complications. Functional evaluation showed excellent and good results in all cases. Stress-shielding at the site of anchorage of the prosthesis was more pronounced than in adults. Implantation of extendable endoprostheses in children provides a reasonable alternative to rotationplasty, but limb salvage requires more operations

Objectives

The Precice nail is the latest intramedullary lengthening nail with excellent early outcomes. Implant complications have led to modification of the nail design. The aim of this study was to perform a retrieval study of Precice nails following lower-limb lengthening and to assess macroscopical and microscopical changes to the implants and evaluate differences following design modification, with the aim of identifying potential surgical, implant, and patient risk factors.

Our aim was to determine the relationship between age and the mechanical and physical properties of trabecular bone, to describe the patterns in which the variations in these properties take place, and to investigate the influence of the physical properties on the mechanical characteristics of trabecular bone during growth. We used 30 lambs in three age groups and 20 sheep in two age groups. Cubes of subchondral bone were cut from the proximal tibia according to a standardised protocol. We performed non-destructive compression tests of the specimens in three orthogonal directions and compression tests to failure in the axial direction. The physical properties of the specimens were also determined. The data were correlated with age and compared in skeletally immature and mature animals. Multiple regression analyses were performed between the mechanical and the physical properties. Age correlated positively with elastic modulus, bone strength, energy absorption to failure, elastic energy, mechanical anisotropy ratio, tissue density, apparent density, apparent ash density, and bone mineral content, and inversely with ultimate strain, viscoelastic energy absorption, relative energy loss, the collagen content of bone and the percentage porosity. The values of all variables were significantly different in the skeletally mature and immature groups. The apparent density of trabecular bone tissue was found to be the major predictor of its compressive mechanical properties. Together with the content of bone muscle and bone collagen, the apparent density could explain 84% of the variation in the elastic modulus, whereas only a small portion of the variation in ultimate strain could be explained by the variation in apparent density

1. Double osteotomy was performed on 1 50 knees between 1961 and 1969. The first fifty-seven cases were assessed independently. 2. The operation of osteotomy of the upper end of the tibia and the lower end of the femur is described. it is emphasised that the osteotomy sites are close to the bone ends and well within the cancellous expansion. 3. The indications for the operation are pain and loss of function in a mobile arthritic knee joint. 4. Flexion of the knee is important during the operation to allow the popliteal artery to be moved away from bone. Arteriograms at necropsy show the danger of damaging the popliteal artery when the knee is extended. 5. The operation appears to be equally effective in osteoarthritis and rheumatoid arthritis. The proliferated synovium of the active rheumatoid knee regresses rapidly following operation. 6. The operation has resulted in relief of pain and increase in function in many knees which had no deformity. When a deformity did exist before operation recurrence of the deformity did not appear to influence the result. 7. The cause of relief of symptoms after osteotomy is not known, and it is suggested that answers to the following questions should be sought: Why are some arthritic knees painful and some not ? Why does physiotherapy relieve pain ? Why does osteotomy relieve pain? Why is double osteotomy followed by regression of synovial proliferation ? Why does osteotomy sometimes fail ? Would osteotomy of one bone (tibia or femur) be sufficient?

1. The effect of immobilisation on bone formation has been investigated in the rat. As chlortetracycline has the property of being deposited preferentially in areas of newly deposited bone, its uptake can be used as a reflection of osseous formation. 2. One hind limb of albino rats was immobilised either by section of the second, third and fourth lumbar nerve trunks or by section of tendo calcaneus and ligamentum patellae. The incorporation of chlortetracycline was determined quantitatively in the femur and tibia of both hind limbs at intervals after immobilisation. 3. Tetracycline uptake is expressed in terms of bone weight, this being most important in order to obtain correct values. 4. A comparison between the tetracycline uptake and the weight of the bones gives information about the rate of bone destruction. 5. In animals immobilised by nerve section three phases can be distinguished: a first phase with diminished bone formation, a second with increased formation and increased destruction and a third phase with diminished bone formation. Both mechanisms, decreased formation and increased destruction, are therefore important in the production of immobilisation osteoporosis; their relative importance depending upon the duration of the immobilisation. 6. In animals immobilised by tendon section the mechanical function becomes restored in the second week as a result of healing: this explains the rapid compensation for the initial loss of weight of the bones accompanied by a marked increase in tetracycline uptake. 7. These results are discussed and compared with information in the literature. Variations in bone formation and destruction rates with time could explain the varied results reported by other authors