Disc degeneration starts as an avascular necrosis. In the lower lumbar area the discs deteriorate early because of mechanical stresses. During certain early periods of degenerative changes a mechanical disorder between the annulus and the posterior longitudinal ligament may cause tiredness and pain. When the disc is completely degenerated and has lost its physical properties backache disappears.

A considerable proportion of patients with thrombosis of the aorta or its bifurcations exhibit low back pain either alone or in conjunction with other symptoms of this disease. Arterial obstruction should be considered in every patient presenting himself with low back pain. The importance of the history in making this diagnosis cannot be overemphasised. Back or leg pain, or both, coming on after exertion should suggest the diagnosis even in the absence of the other well recognised symptoms of arterial insufficiency. Therefore, to affirm or deny this suspicion, it is essential that palpation of the femoral and peripheral pulses be made a routine and integral part of every orthopaedic examination in patients complaining of low back pain. When pulses are not palpable or are diminished, and in the absence of other clear musculo-skeletal disease, consideration should be given to further and more specific diagnostic procedures, such as aortography. Only in this way can an occasional baffling and elusive case of troublesome backache be fully understood and the appropriate treatment instituted.

1. A relatively simple method of spinal fusion with internal splinting by screw fixation has been described. Complications have been few.

2. Emphasis is placed upon thorough removal of soft tissue, correct placement of screws of good length, the exposure of bleeding bone wherever possible in the fusion area, and the use of well packed cancellous bone.

3. There is enough spongy bone in one posterior superior iliac spine for an ordinary spinal fusion, and, if more is needed, the other is readily available through the same skin incision. Not only is cancellous bone more desirable than a massive cortical graft, but the leg is spared, allowing early walking and freedom from complications in the limb.

4. The lateral articulations are left intact.

5. Screw fixation has eliminated the use of external support except in spondylolisthesis, or when so much bone has been removed during laminectomy that good fixation cannot be obtained.

6. Early, sometimes immediate, relief of symptoms is usual after operation, and early walking with moderate activity is desirable.

7. When the operation was done for degenerative changes with no apparent defect in the laminae there was no radiological evidence of failure of fusion after operations at one level, but two failures were found after attempted fusions at multiple levels.

8. Root irritation from screw contact in two patients was due to faulty technique. A method of screw placement to avoid this complication is described and illustrated by radiographs and photographs of a cadaver specimen.

9. There has been no known instance of an adverse psychological effect from the use of screws. Rather, there has commonly been a lively and healthy interest shown in the factor which has allowed early activity.

1. Posterior fusion of the spine in scoliosis cannot be relied upon to maintain correction of the curve or to prevent progression of a vicious resistant curve. It can, however, hold to some extent the correction of a mobile curve and the compensation of a fixed curve.

2. Despite generally poor results as assessed radiographically, the clinical improvement is often gratifying. Most patients claim to be greatly improved: the spine feels stronger, there is less fatigue, and balance is better controlled. Moreover, visible deformity may be improved markedly even though the anatomical correction as observed radiographically is slight (Figs. l0 and 11).

3. It is believed that the true cause of relapse is that the bone formed from sliver grafts remains immature for a long time. Even when incorporated with the immature bone of the child's spine or the mature bone of the adult spine, it remains soft and resilient. When subjected to the stresses and strains of weight bearing and gravity, and then to the unnatural forces which initiated or perpetuated the scoliosis, this immature bone undergoes remodelling to Wolff's Law—like the neck of the femur after slipping of the upper femoral epiphysis. The forces that alter the grafted bone are not only lateral forces but also—perhaps more important—rotational forces. There seems to be a definite link between the degree of rotation and the amount of relapse, correction being maintained best when rotation is least.

1. The indications for correction of severe rigid kyphosis by lumbar osteotomy are described.

2. The fatal complications in a series of a hundred cases are listed. With more experience of this operation they should be considerably reduced.

3. Among the non-fatal complications the low incidence of recurrence of the deformity severe enough to require further operation is noteworthy.

1. Two types of paralytic dislocation of the hips are discussed.

2. The mechanics of dislocation and the methods of reduction are described, with emphasis on the importance of maintaining or increasing stability where possible.

Fifty cases of iliopsoas transfer have been reviewed. The indications for operation, operative technique and post-operative care have been described. It seems that the iliopsoas muscle transferred laterally through the ilium acts as a better hip stabiliser than it does in its original position. The operation should not be undertaken by a casual operator and should be performed first in the post-mortem room.

1. The results of fifty-three operations in forty adults with a persistent congenital dislocation of the hip have been reviewed.

2. Arthrodesis as a primary operation was successful in five of six patients, giving a pain-free hip and good function. After an arthroplasty or an osteotomy that had failed to relieve symptoms it was successful in only one patient.

3. Cup arthroplasty on one hip relieved pain in five of nine patients, giving an increase in functional activity, although the range of hip movement was often disappointing. Bilateral cup arthroplasty, performed in four patients, gave partial relief in three, but did not permit an increase in activity.

4. High osteotomy of the femur was undertaken in eleven patients with a unilateral dislocation; pain was rarely relieved, and a stiff hip resulted in seven.

5. Low osteotomy in nine patients gave some relief from pain with a good range of hip movement.

6. In unilateral dislocation arthrodesis appeared to be the operation of choice, although cup arthroplasty was capable of giving a good functional result.

7. In bilateral dislocation, when only one hip was painful, the results of both these operations were on the whole good. When both hips were painful the operations that had been performed seldom gave clinical improvement.

8. High osteotomy of the femur appeared to have little place in the treatment of the painful dislocated hip. Low osteotomy, either of the Schanz or Batchelor type, appeared to be of value mainly as a salvage procedure when other measures had failed to give relief.

1. Congenital dislocation of the hip in identical twins is reported.

2. The heredity of congenital dislocation of hip is discussed. Studies in twins show that congenital dislocation of hip is probably a hereditary dysplasia of the acetabulum and upper end of the femur, and that external factors play a less important role.

1. The semilunar cartilages are part of the rotator mechanism of the knee joint.

2. Movement of the weight-bearing knee comprises synchronous lateral rotation of the tibia with extension and medial rotation of the tibia with flexion.

3. When this synchrony is disturbed, injuries to the semilunar cartilages result.

4. Damage to the anterior two-thirds of the medial cartilage blocks lateral rotation of the tibia, with consequent physical signs that are pathognomonic of the retracted and the bowstring cartilage, which are the most common types of injury.

5. Each type of cartilage injury produces its own pattern of erosion of articular cartilage and its own sequence of symptoms as so-called arthritis develops.

6. The sequence of symptoms may be halted and often reversed by removal of the torn cartilage. Operation is warranted in most cases however long the history and whatever the age of the patient.

7. The development of medial retropatellar arthritis is explained. The symptoms are often relieved by removal of the medial semilunar cartilage and adequate post-operative rehabilitation.

1. Sixty feet operated upon either by triple or pantalar tarsal fusion for instability after poliomyelitis were re-examined ten to twenty-four years later.

2. After triple fusion with preservation of the ankle joint there was a striking absence of late osteoarthritis of the ankle, and only a low incidence of troublesome lateral instability of the ankle. The results were generally good provided the patient had reasonable power of extension of the knee.

3. Triple arthrodesis for completely flail foot in patients without active muscle control of the knee was often disappointing, so far as the limb as a whole was concerned, because of a persistent flexion deformity of the knee which usually necessitated the wearing of an appliance.

4. The results of pantalar arthrodesis for the flail foot were satisfactory. When this operation was performed (with the foot in slight equinus) in patients who lacked active extension of the knee it helped to stabilise the knee in walking by encouraging hyperextension.

1. Eighty consecutive open fractures of the tibial shaft were treated by primary internal fixation and wound closure. Wound healing was complicated by deep infection in eight patients (10 per cent) and by skin loss of varying degree in ten (l2·5 per cent).

2. Careful selection of patients on the basis of associated soft-tissue injuries is urged. A simple method of grading open fractures by the appearance of the wound and adjacent skin and the effectiveness of wound closure is suggested. If internal fixation is indicated on mechanical grounds, the nature of the soft-tissue injury should be the deciding factor in the choice of the method of treatment. In the less severe (Grade 1) fractures internal fixation and wound closure may be safely employed. In the severe (Grade 3) injuries, primary wound closure with or without internal fixation should be avoided. Moderately severe (Grade 2) fractures should be carefully assessed and treated by internal fixation and wound closure only if primary wound healing is confidently expected.

3. Wound healing by first intention requires, in addition to adequate debridement of the deep layers of the wound, careful approximation of healthy wound edges without excessive tension. An adequate knowledge of skin-plastic procedures is essential to achieve this.

4. A combination of systemic penicillin and streptomycin in adequate doses is a safe and effective prophylactic antibiotic for use in the treatment of open fractures.

The early management of bilateral congenital popliteal webbing in a brother and sister is described. There was no familial history of webbing, but the maternal grandfather had a hare-lip. Although the sciatic nerve is so unfavourably placed in the web, correction of the flexion deformity can apparently be carried out safely after plastic repair of the skin by Z-plasty and excision of the fibrous web cord alone, without causing a traction paralysis. These cases appear to be unique in that the patients are siblings of different sex with identical congenital abnormalities of bilateral webbing, cleft palate and fistulae of the mucous membrane of the lower lip.

1. A case of congenital arteriovenous aneurysm involving the left femur, with dangerous cystic changes in the shaft of the bone, is described.

2. After ligation of the anastomosing fistulae the radiological appearance of the femur became normal.

1. A case of giant-cell tumour of the proximal end of the humerus treated by resection and fibular grafting twenty-nine years ago is reported. An excellent functional result has been maintained.

2. The literature is reviewed and the results claimed by earlier workers are noted.

3. The present field of application of the operation is probably in cases of advanced or recurrent giant-cell tumour of bone.

1. The occurrence of multiple centres of ossification in the epiphyses of the long bones of the hand and foot is shown to be frequent, and in the first metatarsal and first proximal phalanx of both hand and foot in both sexes the normal pattern of epiphysial ossification must be regarded as taking place in this way.

2. Multiple centres of ossification are shown to occur simultaneously in several epiphyses of the same hand or foot.

3. There seems to be a relationship between the shape of an epiphysial area and the pattern of ossification occurring within it.

4. Care should be taken to avoid confusing these normal patterns of ossification with radiological appearances caused by pathological changes.

Plasmin, a proteolytic enzyme derived from the blood, may be activated in synovial fluid both by trauma to synovial tissue and cartilage, and by kinases produced by streptococci and staphylococci. Plasmin normally removes fibrin, but, when in excess, attacks the protein of cartilage matrix. Conversely, excess inhibitor favours the persistence of fibrin and subsequent fibrosis. The relationship of excess protease to the chondrolysis of suppurative arthritis and of excess inhibitor to pannus formation and fibrous ankylosis in tuberculous and rheumatoid arthritis are discussed.

1. The results of viscosity measurements on a number of normal, traumatic and osteoarthritic synovial fluids from human knee joints are described and discussed.

2. A decrease of the viscosity of normal synovial fluid with age has been found.

3. The decrease of the viscosity with age and in the pathological groups is analysed and its relation to the viscous anomaly is considered (Fig. 6).

4. The question whether dilution or depolymerisation is the important factor in decrease of viscosity in these groups, and the value of viscosity measurements as a whole, are discussed.

5. Measurements of pH have been made on the same groups of synovial fluids and on the blood of patients in these groups.

6. The mean values for blood and synovial fluid differ significantly, and the pH of the synovial fluid of adolescents is significantly higher than at other ages.

7. There is no significant difference between the traumatic and osteoarthritic groups, but both are significantly less than the normal.

8. In both fluids the peak frequency in all three groups is the same, that for blood being 7·3 to 7·5 and that for synovial fluid being 7·5 to 7·7 (Fig. 7).

1. A quantitative study of phosphatase distribution in the limb bones of growing rabbits is reported.

2. Alkaline phosphatase is present in high concentrations in areas of deposition of new bone. Both local concentrations and the total alkaline phosphatase content of a bone are found to decrease with age. There is good correlation between total alkaline phosphatase activity and monthly increment of weight.

3. Acid phosphatase is present in these bones in greatly less concentrations than alkaline phosphatase.

4. The acid phosphatase of bone shows nearly full activity in the presence of 0·5 per cent formaldehyde. It can be subdivided into two enzymes with characteristically different distributions by the effect of M/100 tartrate on activity.

5. The formaldehyde-stable and tartrate-stable acid phosphatase of rabbit bone (FTS) has a distribution very similar to that of alkaline phosphatase, though very much less in amount, and, like the latter, declines in activity as the bone matures.

6. Tartrate-inhibited, formaldehyde-stable acid phosphatase (FSTI) is found mainly in red marrow and cancellous bone, and full activity persists in mature bone. This enzyme may be associated with resorption and remodelling of bone, or it may represent residual activity under these conditions of the acid phosphatase of developing erythrocytes in the marrow.

Everywhere I visited, both in England and in other parts of Europe, I met with wonderful hospitality and friendliness. Generally our common language was English, and I felt thoroughly ashamed of my poor efforts at speaking other languages.

During my tour in England, France, Germany, Austria, Italy, Denmark, Norway and Sweden I heard many new ideas propounded, and have seen many new and different methods of treatment. In particular I have been able to compare thoughts on such subjects as tuberculosis of the spine, congenital dislocation of the hip, osteoarthritis of the hip, scoliosis, many aspects of trauma, Perthes' disease, hand surgery, poliomyelitis, paraplegia, the treatment of cerebral palsy, rehabilitation of patients suffering from all kinds of orthopaedic disabilities, and surgical appliances. I am very grateful indeed to the British Orthopaedic Association for making this six-months' tour possible.