Objectives

X-linked hypophosphataemic rickets (XLHR) is a disease of impaired bone mineralization characterized by hypophosphataemia caused by renal phosphate wasting. The main clinical manifestations of the disorder are O-shaped legs, X-shaped legs, delayed growth, and bone pain. XLHR is the most common inheritable form of rickets, with an incidence of 1/20 000 in humans. It accounts for approximately 80% of familial cases of hypophosphataemia and serves as the prototype of defective tubular phosphate (PO4³⁺) transport, due to extra renal defects resulting in unregulated FGF23 activity. XLHR is caused by loss-of-function mutations in the PHEX gene. The aim of this research was to identify the genetic defect responsible for familial hypophosphataemic rickets in a four-generation Chinese Han pedigree and to analyze the function of this mutation.

Objectives

The objective of this study was to characterize the effect of rifampin incorporation into poly(methyl methacrylate) (PMMA) bone cement. While incompatibilities between the two materials have been previously noted, we sought to identify and quantify the cause of rifampin’s effects, including alterations in curing properties, mechanical strength, and residual monomer content.

The term "congenital scoliosis" contributes little to our understanding of aetiology, for "congenital" simply means "to be born with" and is applicable to deformities present at birth whether these are genetically determined or acquired in utero. The presentation of monozygotic twins, one of whom has congenital scoliosis (vertebral anomalies) while the other is normal, provides a rare opportunity to study the cause of this deformity. Three pairs of monozygotic twins, previously unreported, are presented with a review of the previous literature. These cases add weight to the argument that congenital scoliosis may be acquired in utero rather than being genetically determined

A total of 138 revision hip arthroplasties in 134 patients, all operated upon by one surgeon, were followed for an average of 7.4 years. The overall results were reasonable, with good to excellent Mayo hip scores in 62% and little or no pain in 86%. These results were independent of body weight, age, primary diagnosis and type of arthroplasty used. The incidence of radiological loosening was alarming, though comparable to that found in other series. Our findings indicate that it may be wise to replace both components even when, after careful assessment before and during operation, one of them seems to be securely fixed

The lower limbs of five cadavers were dissected and the lengths of the muscle fibres and the weights of all the muscles below the knee were measured. From this information the relative strength and excursion of each muscle was determined. We found that the plantarflexors of the ankle were six times as strong as the dorsiflexors. We have therefore discarded the concept of "muscle balance" in tendon transfer surgery and propose that task appropriateness should be the guide. The constant relationship between muscle fibre length and muscle excursion means that contractures are accompanied by decreased excursion. Tendon lengthening improves deformity but does not improve the decreased active range of movement

The serum liver enzyme levels of 40 consecutive patients before and after cemented hip replacement were compared with a control group having operation without use of cement. Serum gammaglutamyl transferase (SGGT) was abnormally raised, for more than four days, in 12 of the 40 patients (32%) in whom bone cement was used, compared with one of the 36 control patients. The changes in SGGT levels after operation correlated with the weight of cement used (r = 0.66, p less than 0.001), but there was return to normal levels in all patients. A temporary dose-related effect of bone cement on liver function is demonstrated

1 . Attention is drawn to the not infrequent occurrence of downward subluxation of the shoulder joint accompanying fractures of the upper end of the humerus. 2. Such cases fall into early or late groups according to the time of onset of the subluxation. 3. The subluxation often disappears spontaneously, but it may persist and cause disability. It cannot safely be disregarded. 4. The etiology is discussed and experiments are described which lead to the conclusion that the subluxation is due chiefly to lack of tone in the scapulo-humeral muscles supporting the weight of the limb. 5. It is suggested that the use of a collar and cuff sling as a method of treatment for fractures of the shoulder is not without danger. A triangular sling usually prevents or cures the displacement

A study of heel-pad thickness and compressibility using lateral radiographs, loaded and unloaded by body-weight, was carried out on 70 patients with plantar heel pain and 200 normal subjects. The heel-pad thickness and the compressibility index (resistance to compression) were greater in the patients than in normal subjects and significantly increased with age. In normal subjects, the thickness was greater in males than in females, but there was no significant difference in the compressibility. Increased weight led to an increase in heel-pad thickness and compressibility index. The body mass index was greater in patients with plantar heel pain than in normal subjects and 40% of the patients were considered to be overweight. Increase in the compressibility index indicates loss of elasticity and an increased tendency to develop plantar heel pain

A series of experiments showing how posture affects the lumbar spine is reviewed. Postures which flatten (that is, flex) the lumbar spine are compared with those that preserve the lumbar lordosis. Our review shows that flexed postures have several advantages: flexion improves the transport of metabolites in the intervertebral discs, reduces the stresses on the apophyseal joints and on the posterior half of the annulus fibrosus, and gives the spine a high compressive strength. Flexion also has disadvantages: it increases the stress on the anterior annulus and increases the hydrostatic pressure in the nucleus pulposus at low load levels. The disadvantages are not of much significance and we conclude that it is mechanically and nutritionally advantageous to flatten the lumbar spine when sitting and when lifting heavy weights

1. The Küntscher method of intramedullary reaming and nail fixation was applied to thirty-five cases of non-union of the lower extremity, twenty femurs and fifteen tibias. A bone graft was generally not used. 2. Most of the patients were allowed to bear weight and to exercise the joints within a few days of the operation. Additional measures such as pre-operative surgery for infection or distraction of shortening were used in some cases. 3. The pseudarthrosis healed in all cases, even when infection was present. The nails were generally not removed until after healing had occurred. 4. It is concluded that the Küntscher method gives remarkably rapid consolidation and restoration of function even in difficult cases of non-union of shaft fracture, particularly of the femur

1. A collected series of forty-seven traumatic dislocations of the hip in children is reported and reviewed in detail. 2. All were simple hip dislocations, and no child was included in whom there was any other injury to the affected joint. 3. All were posterior dislocations. 4. No anatomical predisposition was observed. 5. Significant complications occurred in fourteen children: avascular necrosis of the head of the femur in four, degenerative joint changes in three, premature epiphysial fusion in one and overgrowth of the femoral head in six. Study of the children with these complications revealed no common cause except the dislocation itself. 6. The injury responsible was often trivial. 7. The results suggest that it is harmless to bear weight four weeks after reduction

1. The structure and blood supply of the femoral head and neck, the mechanics of weight bearing, and the known effects of an inert foreign body are considered in relation to arthroplasty. 2. Some artificial hips are reviewed from the biomechanical standpoint. 3. From the information now available it is inferred that mechanical soundness and clinical success are not only co-related but interdependent; and that the mechanical problem of design offers most scope for further development at the present stage of our knowledge. 4. To this end six propositions are submitted. 5. A theoretical replacement arthroplasty, confined to the head and neck, in which breakdown of the component forces suggests that reciprocal use of both tensional and compressive loads might occur as in the natural femur, is described

Compartment syndrome is a unique form of ischaemia of skeletal muscle which occurs despite patency of the large vessels. Decompression allows the influx of activated leucocytes which cause further injury. Vitamin C is a powerful antioxidant which concentrates preferentially in leucocytes and attenuates reperfusion-induced muscle injury. We have evaluated the use of pretreatment with oral vitamin C in the prevention of injury caused by compartment syndrome in a rat cremasteric muscle model. Acute and delayed effects of pretreatment with vitamin C were assessed at one and 24 hours after decompression of compartment syndrome. Muscle function was assessed electrophysiologically. Vascular, cellular and tissue inflammation was assessed by staining of intercellular adhesion molecule-1 (ICAM-1) and by determination of the activity of myeloperoxidase (MPO) in neutrophils and tissue oedema. Compartment syndrome impaired skeletal muscle function and increased the expression of ICAM-1, activity of MPO and muscle weight increased significantly. Pretreatment with vitamin C preserved muscle function and reduced the expression of ICAM-1, infiltration of the neutrophils and oedema

The Fulkerson osteotomy has proved to be a reliable treatment for subluxation of the patella due to malalignment. Aggressive rehabilitation in the early postoperative period is unwise since the proximal tibia is weakened by the oblique osteotomy. Early weight-bearing and unrestricted activity have caused fractures in a few patients. Even late in the postoperative period the osteotomy may adversely influence the biomechanical properties of the proximal tibia. We describe two athletes who sustained a fracture of the proximal tibia, during recreational activities, six months after a Fulkerson osteotomy. Both had been bearing full weight for about ten weeks without complaint. Bony healing of the osteotomy had been demonstrated on plain radiographs at ten and at 12 weeks. After a Fulkerson osteotomy, jogging and activities which impose considerable impact force should be discouraged for at least nine to 12 months

Impedance plethysmography has great potential in the non-invasive detection of dangerous iliofemoral thrombosis. It was used to examine 198 patients undergoing total hip replacement for evidence of proximal venous segment thrombosis. There were 13 abnormal results, and subsequent venography in 12 of these revealed a false-positive rate of 4.0%; there was one false-negative result giving a sensitivity of 85.7%. A venographic study of 46 other patients clinically suspected of having a proximal deep-vein thrombosis confirmed this sensitivity. The iliofemoral thrombosis rate was 3.9% after total hip replacement and this rate increased significantly in the group of patients over 70 kg in weight. Impedance plethysmography was found to be a useful non-invasive screening procedure for potentially fatal proximal venous thrombosis

The spinal stenosis syndrome is a potential hazard when congenital or developmental narrowing of the bony canal, particularly in its lateral recesses where it can be demonstrated by axial tomography, places the emergent nerve root and its blood supply at risk to further small compressive elements. When lumbar disc degeneration allows rotatory and lateral instability, posterolateral bulging of the annulus fibrosus into the root canal occurs when weight is taken on the ipsilateral lower limb. Symptoms of the spinal stenosis syndrome do not arise until the development of this instability. To relieve the symptoms, the nerve root must be freely mobilised and decompressed by full lateral decompression, with partial or total facetectomy if necessary, by enucleation of the intervertebral disc and by removal of the posterolateral portions of the annuli fibrosi

Static force transmission at the knee is analysed using measurements from radiographs showing the position of the line of body weight and also the bones of the knee in their correct orientation during function. With this technique it is possible to suggest values for a variety of forces acting at the knee. During function the degree of knee flexion is not as important as the angle that the thigh makes with the vertical. The tension in the extensor mechanism is not the same above and below the patella. Failure to recognise these two features results in fundamental errors. The patella, the effects of patellectomy and of forward displacement of the attachment of the patellar ligament are discussed. The importance of the transmission of force in the coronal plane is emphasised with particular reference to total knee replacement. It is suggested that small errors of geometry, as seen in the anteroposterior radiograph, can produce large changes of load

Aims

Patient-specific instrumentation of total knee arthroplasty (TKA) is a technique permitting the targeting of individual kinematic alignment, but deviation from a neutral mechanical axis may have implications on implant fixation and therefore survivorship. The primary objective of this randomized controlled study was to compare the fixation of tibial components implanted with patient-specific instrumentation targeting kinematic alignment (KA+PSI) versus components placed using computer-assisted surgery targeting neutral mechanical alignment (MA+CAS). Tibial component migration measured by radiostereometric analysis was the primary outcome measure (compared longitudinally between groups and to published acceptable thresholds). Secondary outcome measures were inducible displacement after one year and patient-reported outcome measures (PROMS) over two years. The secondary objective was to assess the relationship between alignment and both tibial component migration and inducible displacement.

1. Deformities of the foot in children with myelomeningocele are described and classified. The results of a policy of operative correction of deformity in 148 patients all of whom had had at least one operation on the foot between 1947 and 1965 are described. 2. In 241 feet in which there were deformities 433 operations were performed, including tenotomies, soft-tissue divisions, tendon transfers and bony procedures. At the time of review successful correction of deformity had been obtained in 81 per cent with a plantigrade foot that could bear weight safely, and with a distribution of muscle activity that required minimal external support and presented the least liability to recurrent deformity. 3. The management of individual deformities is described and the causes of failure are analysed and discussed

1. An operation to re-establish the continuity of the bone after resection of tumours of the lower end of the femur or upper end of the tibia is described. 2. Sound bony union may be obtained, allowing walking with weight bearing after three to four months. 3. The combination of a massive tibial or femoral graft (Juvara procedure) with an intramedullary nail, a massive homogenous graft, and fixation of the patella to the autograft to accelerate its revascularisation. has given constant and rapid bony union in five cases. 4. This possibility gives real value to wide resection in the treatment of severe cases of giant-cell tumours. especially those that are recurrent. osteolytic or suspect of malignancy. 5. Its value in the treatment of sarcoma cannot be assessed in so short a series