1. Some of the more common and obvious clinical syndromes arising from mechanical and degenerative derangements of the lumbar spine are defined.

2. Some principles in the selection of cases for surgical treatment are discussed and it is stressed how small a part operative intervention plays in the overall problem of low back derangement.

3. Details of surgical technique in the eight types of syndrome are described from past experience in the author's clinic, but not without recognition of the fluidity of this comparatively new field and its continuing evolution.

1. Seven cases of sacral extradural cyst are reported.

2. The etiology and clinical features are discussed and the literature reviewed.

3. The differential diagnosis is discussed; certain features, useful in making the diagnosis of sacral extradural cysts, are recorded.

4. When a cyst causes symptoms excision brings relief. Because some cysts are symptomless, it is important to exclude an accompanying prolapsed intervertebral disc.

Thirty years' experience of excision of the trapezium for osteoarthritis of the trapeziometacarpal joint has shown that this simple operation is entirely satisfactory.

1. A new procedure, called "the extensor diversion graft operation", has been devised for correcting the deformity and reducing the disability of the intrinsic minus fingers so commonly seen in leprosy.

2. The procedure consists of the insertion of a free tendon graft which spans the metacarpophalangeal joint along its volar aspect and is attached at both ends to the extensor mechanism, to the extensor tendon proximally and to the lateral band distally.

3. The procedure reduces extensor dominance at the metacarpo-phalangeal joint and improves the balance of forces, allowing the assumption of a straight posture by use of the extrinsic muscles.

4. The assessment of function of ninety-seven fingers on average eight months after operation has shown that in addition to correction of deformity, this procedure in the majority of cases also restores partial independence of movement at the metacarpo-phalangeal and proximal interphalangeal joints, to such an extent that the finger can reach and hold a functionally useful position.

5. One advantage of the procedure is that it obviates the need for re-education of muscles.

1. The phosphonates are simple chemical compounds containing P-C-P bonds which are resistant to the action of naturally occurring phosphatases and pyrophosphatases. They inhibit the formation and dissolution of apatite crystals in vitro and prevent ectopic mineralisation and bone resorption in animals.

2. In man one diphosphonate (EHDP) has been shown to reduce the excessive turnover of bone in Paget's disease and also appears to slow the mineralisation of ectopic bone matrix in myositis ossificans progressiva.

3. The possible uses of the diphosphonates in bone disorders with excessive resorption and in ectopic mineralisation are being further investigated.

1. The results of excision of the distal end of the ulna in eighty-six wrists of seventy patients suffering from rheumatoid arthritis are presented.

2. There was relief of pain in 93 per cent and restoration of full rotation in 87 per cent.

3. Further destructive changes of the radio-carpal joint were seen in 85 per cent, but these did not affect the good clinical results.

1. Synovectomy of the elbow affected by rheumatoid arthritis is a worthwhile procedure even in the presence of advanced radiological changes.

2. Relief of pain is good (93 per cent) and movement is retained (87 per cent).

3. Although the follow-up in this series was short, averaging nineteen months, the results seem to be maintained.

4. Good access to the joint may be had through medial and lateral incisions, and division of the olecranon is unnecessary. A lateral incision alone is not recommended.

5. The ulnar nerve should be preserved during dissection. Anterior transposition is needed only if there are neurological symptoms before operation.

1. Of fifty consecutive double hemiarthroplasties of the knee for rheumatoid arthritis using Maclntosh prostheses, forty-six were available for detailed assessment in thirty-six patients after one to six years.

2. Two early deaths were related to the operation but two late deaths were not. Three knees required revision, one of them twice.

3. The late results were 87 per cent good and 13 per cent fair. No patients followed up were the same as previously or worse. Every patient stated that he would have the operation performed again.

4. In our experience this operation in carefully selected patients produces satisfactory results. It is essential that great care is given to the operative technique.

1. Anterior synovectomy was undertaken in sixteen knees of fourteen patients with rheumatoid arthritis associated with popliteal or calf cysts. Subsequent changes in the knees and cysts were observed clinically and by arthrography.

2. In all instances there was alleviation of symptoms and in fourteen cases the cysts disappeared.

3. It is suggested that anterior synovectomy is the logical treatment of a posterior cyst associated with rheumatoid arthritis of the knee.

1. The results of arthroplasty of the forefoot in thirty-eight patients with polyarthritis have been analysed in detail. Sixty-five feet had been operated on by one of three different techniques–Kates-Kessel-Kay, Fowler or Clayton–though sometimes with modifications.

2. The subjective results were remarkably good. The patients were completely satisfied with forty-two operations, satisfied in most respects with twenty-one, and dissatisfied with only two.

3. The commonest cause of persistent pain was prominence of one metatarsal stump; great care must be taken at the time of operation to ensure that the metatarsals are trimmed to equal length.

4. The objective results were less satisfactory. The lateral four toes were usually functionless, the gait was never normal and the walking distance was still restricted, though often by other factors. The operation, therefore, should be carried out only in patients with severe pain and disability.

5. A comparison of the results of the three different techniques of operation showed no major differences.

1. The incidence of failure of wound healing by primary intention due to infection, haematoma and gaping of wound edges, has been compared in 100 patients with rheumatoid arthritis and in 100 matched controls following a variety of orthopaedic operations.

2. There were thirty-one cases of failure of wound healing in the patients with rheumatoid arthritis and sixteen in the controls (P< ·02). There was no significant difference in the numbers of infected wounds or in those in which a haematoma developed. However, there was a significant excess of wound edge separation in the rheumatoid patients (thirteen) compared with the controls (four) (P< ·05).

3. The problems of wound healing were minor since there was no difference in the mean number of days ±1 standard deviation to wound healing between the patients: l6·6±7·5 days; and the controls: 15·2±7·9 days.

4. There was no correlation between duration or severity of rheumatoid disease and wound healing.

5. There was no difference in wound healing between patients with sero-positive and seronegative disease.

6. Forty-nine patients received corticosteroid therapy in small dosage. This was associated with an increased incidence of wound infection. Treatment for more than three years was associated with a significant increase in the mean number of days to wound healing.

7. The results are discussed in the light of the increased incidence of infection in several sites in patients with rheumatoid arthritis and of the effect of corticosteroid therapy on wound healing in man and experimental animals. It is suggested that more marked abnormalities might have been expected, and that these findings may need to be considered in the future surgical management of such patients.

1. Three families with the characteristic changes of the nail-patella syndrome are reported. In addition to the well established bone and nail defects they had soft-tissue contractures, web formation around the elbows and muscular hypoplasias. The literature on soft-tissue changes is reviewed and their importance emphasised.

2. Asymmetrical joint development is considered to be a characteristic feature of the syndrome.

3. The incidence of renal disease in our families is recorded.

4. The literature on the basic defect is reviewed. The likelihood of a primary alteration in connective tissue chemistry is considered.

1. A specially designed splint is described with which it is possible to maintain the reduction of a paralytic dislocation in a child with spina bifida cystica. The results of its use in a series of thirteen cases are recorded.

2. It is suggested that all such children presenting in the first year of life, in whom the power of the flexor and adductor muscle groups is preserved, should be treated initially in this way until the prognosis for the individual can be accurately assessed.

3. The theoretical implications of the findings are discussed.

1. Thirty-one patients treated with the Ellis plate for Smith's fracture have been examined and the results of the operation are presented.

2. The Type 1 fractures can usually be treated equally well by plaster or by internal fixation. The only compelling indication for open reduction and fixation with the Ellis plate is persistent anterior angulation at the fracture site despite the external splintage.

3. The Type 2 fracture should be treated by open reduction and fixation with the Ellis plate.

4. The Ellis plate is not indicated for the routine treatment of Type 3 fractures.

1. A case of congenital bowing of the tibia is described in which pseudarthrosis developed and recurred after nine operations performed by the age of ten years.

2. Union was finally secured by a procedure based on deep impaction of the trimmed upper fragment into the reamed-out lower fragment. This was followed by a Boyd type of partial amputation of the foot with calcaneo-tibial arthrodesis.

3. The end-bearing stump four years later is entirely satisfactory and the simple prosthesis gives equality of leg lengths.

1. Five cases of fibrosarcoma arising after radiotherapy in cases of ankylosing spondylitis are reported.

2. The relationship of the tumours to irradiation is discussed.

3. Objective neurological signs arising in the lower limbs of patients with ankylosing spondylitis after a latent period following radiotherapy may indicate an underlying sarcoma.

1. The question whether amputation for lower femoral osteosarcoma should be by disarticulation of the hip or through the upper femur to leave a stump is discussed.

2. Sixty-eight such patients are reviewed. Thirty were treated by disarticulation and thirty-eight by through-femur amputation.

3. There was a 16 per cent incidence of stump recurrence after through-femur amputation, but none after disarticulation. Comparison of survival was not conclusive.

4. Disarticulation of the hip is advised.

1. Three children with metatarsus adductus varus have been found to have ball and socket ankle joints.

2. The effect of this finding on treatment is discussed.

1. Because of the controversy over the clinical effects of corticosteroids on joint tissues a series of experiments on the knee joints of rabbits was undertaken.

2. The articular cartilage of the distal femoral epiphyses of normalcontrols has been compared with that of rabbits treated daily either with cortisone or with methyl prednisolone systemically or by intra-articular injections.

3. The changes caused by intravenous papain and their subsequent recovery have been described, and the adverse effect of corticosteroids on recovery has been assessed.

4. The biological mechanisms involved are discussed, and as a result caution is urged in the administration of corticosteroids in the presence of progressive degenerative joint disease.