1. The hip joint usually acts as the fulcrum of a lever system. 2. The centre of gravity of supported parts, which is usually medial to the hip joint, exerts a rotational effect upon the pelvis. If pelvic position is to be maintained this force must be counterbalanced by hip muscles. 3. The force transmitted by the hip joint is the sum of the supported body weight and the tension in the balancing muscles. This force often exceeds the total weight of the body. 4. In some circumstances the loss of one pound of body weight relieves the hip joint of three pounds pressure. 5. A long femoral neck is an advantage to hip function, but in arthroplasty this must not lead to mechanical failure such as breaking or loosening of the prosthesis, or fracture of the bone. 6. Medial displacement of the femoral head upon the pelvis may cause a great decrease in joint pressure, but medial displacement alone of the shaft upon the head and neck does not influence the mechanics of the joint. 7. The position of the centre of gravity of supported parts is easily altered by slight variations in spinal position. Great changes in hip joint pressure are caused by small coronal spinal movements, but the advantage to man of being able to walk with the eyes steady outweighs the mechanical disadvantage to which his hip is subjected. 8. A femoral abduction osteotomy improves the mechanics of a hip joint deformed in adduction. 9. A walking stick or a crutch is most helpful in relieving joint pressure and reducing the work done by hip muscles

Aims

The prevalence of combined abnormalities of femoral torsion (FT) and tibial torsion (TT) is unknown in patients with femoroacetabular impingement (FAI) and hip dysplasia. This study aimed to determine the prevalence of combined abnormalities of FT and TT, and which subgroups are associated with combined abnormalities of FT and TT.

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.

Cite this article: Bone Joint Res 2020;9(12):857–869.

Aims

Scapular notching is thought to have an adverse effect on the outcome of reverse total shoulder arthroplasty (RTSA). However, the matter is still controversial. The aim of this study was to determine the clinical impact of scapular notching on outcomes after RTSA.

1. In a club foot the small inverted and elevated heel is considered to be the most important deforming influence in preventing complete correction and in promoting relapse. 2. Correction of the varus and an increase in the vertical height of the heel are achieved by opening up the medial aspect of the calcaneum and inserting a wedge of bone. This abolishes the inverting action of the calcaneal tendon and brings the heel down on to the ground directly under the line of the tibia so that it touches first in walking. The weight is then shifted on to the forefoot, as in the normal gait, thus producing gradual correction of supination and adduction. 3. The operation may have to be repeated, but with the varus fully corrected and a plantigrade heel there is no chance of relapse, and progressive improvement, not only in gait and shoe wear but also in the development of the foot and leg, can be expected. 4. Skin closure is a difficulty, and though the resulting scar is sometimes conspicuous, it is masked to some extent by being on the postero-medial aspect of the ankle. 5. The ideal age for the operation is about three to four years, but there is virtually no upper age limit. 6. In older patients presenting severe residual deformity it may be necessary to correct the heel and then the equinus of the forefoot by a tarso-metatarsal wedge, thus avoiding damage to the mid-tarsal and subtalar joints. 7. By adopting these principles, soft-tissue release operations, so often disappointing and sometimes damaging, can be avoided and in no patient should there ever be the need to resort to the mutilating "triple wedge" resection. 8. The most important feature of the operation is correction of the varus; it is better to over-correct than to under-correct (Figs. 20 and 21). It is a simple matter to deal with the valgus later if necessary

1. The synovial membrane and capsule in osteoarthritis of the hip have been studied in twenty-five cases. Dissections have been made on fresh cadavers to establish the normal structure and function of these tissues at different ages. 2. Fragments of bone and cartilage were found beneath the synovial surface in twenty-three cases of the twenty-five cases of osteoarthritis. 3. The source of these fragments is the degenerate articular surfaces. 4. The fibrosis of the synovial membrane and capsule follows the synovial hyperplasia which accompanies the phagocytosis of these fragments. 5. A similar histological picture has been produced by injecting fragmented cartilage into the knee joints of rabbits. The injected fragments are found beneath the surface, and synovial hyperplasia is followed by subsynovial fibrosis. 6. The greatest amount of this joint debris is found in the lowest part of the joint cavity. 7. The joint capsule is particularly sensitive to traction. 8. All parts of the capsule are tight in extension, which is the weight-bearing position. 9. Fibrotic shortening of the capsule in the lowest part of the joint cavity explains many of the symptoms and signs of the disease: pain is caused by an attempt to stretch the capsule; muscle spasm occurs in the muscles supplied by the sensory nerves of this part of the capsule; extension, medial rotation and abduction, which tighten this area, are lost first; progressive shortening causes deformity in the opposite direction, namely flexion, lateral rotation and adduction; the loss of extension causes a more rapid wearing of articular cartilage on weight bearing; subperiosteal new bone is formed on the under-surface of the neck of the femur. 10. The symptomatology is discussed

Aims

The study was undertaken to compare the efficacy of Woodcast splints and plaster-of-Paris casts in maintaining correction following sequential manipulation of idiopathic clubfeet.

Aims

The hip’s capsular ligaments passively restrain extreme range of movement (ROM) by wrapping around the native femoral head/neck. We determined the effect of hip resurfacing arthroplasty (HRA), dual-mobility total hip arthroplasty (DM-THA), conventional THA, and surgical approach on ligament function.

1. The avascular zone in the tendon of the supraspinatus near its insertion was not seen in the other tendons comprising the rotator cuff, except for the superior portion of the insertion of the infraspinatus which, on occasions, showed a small avascular area. The biceps tendon, however, also showed an avascular zone as it coursed over the head of the humerus. It is suggested that the anatomical disposition of these tendons makes them subject to constant pressure from the head of the humerus, which tends to wring out the blood supply to these tendons when the arm is held in the resting position of adduction and neutral rotation. 2. Although this study did not produce any evidence that the relative avascularity of the tendons over a prolonged period could be indicted as the sole cause of the degenerative changes that so commonly occur, it was noted that the degenerative changes occurred first and that they were always most extensive in the areas of avascularity. It was also observed that the zones of relative avascularity preceded, and were not the result of, the degenerative changes. 3. With the onset of tendon degeneration, secondary vascular phenomena were observed. Firstly, there was a reaction that appeared to be a foreign body inflammatory response with the development of vascular tufts of granulation tissue. It was thought that these vascular changes were secondary to the breakdown in the tendons and were not the cause of the breakdown as previously suggested by Anderson and Moore. it was noted, moreover, that with the progression of degenerative changes in the supraspinatus tendon, the tendon became much attenuated and, as it did so, the zone of relative avascularity appeared to extend. This secondary shut-down of the vascular bed might well be caused by an increased tension in the tendon. In those tendons in which spontaneous rupture had occurred, it was noted that the major part of the tendon proximal to the rupture was avascular and showed evidence of much degenerative change. This study therefore suggests that in the operative repair of such lesions it is necessary to excise the degenerate avascular tendon in order to effect a sound repair. It is also suggested that detachment of the supraspinatus muscle from the supraspinous fossa in order to advance the whole muscle belly is the only technique possible to enable the surgeon to replace healthy tendon directly into bone, as suggested by Debeyre and his colleagues

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Aims

Evaluate if treating an unstable femoral neck fracture with a locking plate and spring-loaded telescoping screw system would improve construct stability compared to gold standard treatment methods.

Aims

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

General remarks–Comparison of the two reviews shows that patients with good results return more readily for a review than those with poor results. In middle-aged patients with some disability for walking an attendance of 80 per cent at least is necessary in order to obtain a representative follow-up five to ten years after operation. An outstanding feature of all the operations reviewed is the degree of lasting relief of pain. It is rare to find that a patient with severe hip pain before operation has pain of the same severity after any of these operations at least up to ten years afterwards, and probably for much longer. Generally speaking, although in advancing years stiffness of the hip is undoubtedly a handicap, it is preferable to instability, particularly if this is progressive. A patient can adapt himself to and accept a disability that is permanent and unaltering, but instability increasing in later years can be distressing mentally and incapacitating physically. Cup arthroplasty–There is an element of unpredictability in the results, especially the late results, of cup arthroplasty. Movement decreases and there is a tendency for pain and instability to increase after four or five years. There is little to indicate which case will be successful although the results vary according to the condition for which operation is performed. The operation gives good results, on the whole, for osteoarthritis, particularly when the operation is done on one hip only. Stability is much more important when both hips are involved, and, unless this is good in at least one hip, the results of bilateral operations are poor. "Excellent" results are not obtained in rheumatoid arthritis but few results are "poor." Operations for congenital dislocation of the hip give the most disappointing results. In operations for ankylosing spondylitis there is a high incidence of stiffening of the hip, but many patients are greatly improved in comparison to their state before operation. Displacement osteotomy–The hazard in displacement osteotomy is ankylosis, particularly when internal fixation is not used. Relief of pain and stability are well maintained. The results in general, and for pain in particular, are less good when internal fixation is used. Adduction of the upper fragment of the femur appears to be of value in the production of a good result. In the series examined it was less often achieved when internal fixation was the method of immobilisation. The best results were obtained in cases of congenital dislocation of the hip and there were few "poor" results in cases of congenital subluxation. Excision of the head and neck of the femur and Batchelor's operation–Rehabilitation may take a long time, but the late results are more predictable than in the other operations reviewed. A "fair" result is more likely than an "excellent" one, but late "poor" results are few. Relief of pain is better after excision of the head and neck than after any other operation reviewed

Aims

The aim of this study was to examine the recent trend in delivery of arthroscopic subacromial decompression (ASD) in Scotland and to determine if this varies by geographical location.

Aims

Abnormal femoral torsion (FT) is increasingly recognized as an additional cause for femoroacetabular impingement (FAI). It is unknown if in-toeing of the foot is a specific diagnostic sign for increased FT in patients with symptomatic FAI. The aims of this study were to determine: 1) the prevalence and diagnostic accuracy of in-toeing to detect increased FT; 2) if foot progression angle (FPA) and tibial torsion (TT) are different among patients with abnormal FT; and 3) if FPA correlates with FT.

Aims

The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE). However, there is a risk of developing avascular necrosis of the femoral head (AVN). In this paper, we report on clinical outcome, radiological outcome, AVN rate and complications, and the cumulative survivorship at long-term follow-up in patients undergoing the modified Dunn procedure for severe SCFE.

Aims

Scapular notching is a frequently observed radiographic phenomenon in reverse shoulder arthroplasty (RSA), signifying impingement of components. The purposes of this study were to evaluate the effect of glenoid component size and glenosphere type on impingement-free range of movement (ROM) for extension and internal and external rotation in a virtual RSA model, and to determine the optimal configuration to reduce the incidence of friction-type scapular notching.

Aims

Accurate placement of the acetabular component is essential in total hip arthroplasty (THA). The purpose of this study was to determine if the ability to achieve inclination of the acetabular component within the ‘safe-zone’ of 30° to 50° could be improved with the use of an inclinometer.

1. By questionnaire, an attempt has been made to ascertain the characteristics of a hundred cases of slipping of the upper femoral epiphysis. 2. The principal object has been to see whether an etiological classification would be possible pending an assessment of the results of treatment. 3. Proper statistical analysis has proved impossible because of the incompleteness of the data. 4. As usual, boys predominated and were usually affected as much as three years older than the girls. 5. It was exceptional to find epiphysial slipping in a girl once she had begun to menstruate. 6. Nearly a quarter of the cases were bilateral, or became so after six to twenty-four months or more. 7. Little information came from an enquiry about dietary fads, the estimation of urinary ketosteroid excretion in twenty-three of the patients, or some minor pathological investigations. 8. No convincing evidence was found of skeletal retardation or of general thickening of epiphysial discs, such as might perhaps be expected in a hormonal disturbance characterised by defective epiphysial maturation. 9. From each child with the necessary data, indices of height, weight and build were ascertained, which would indicate his expectation of finding a place among a hundred physically normal children of his own sex and age, and, if so, where that place would be. From these studies four groups of children seemed to emerge: I) what may be called abnormally heavy children who would not find a place among a hundred, or somestimes a thousand, physically "normal" children of their own age and sex; 2) unusually heavy children who would find a place in the heaviest minority of the normal hundred; 3) a very small group of abnormally small people, among whom might be expected the subjects of pituitary infantilism; and 4) a large group of children of average physique for their sex and age. 10. From this information and from clinical evidence in the case returns, it appeared that a quarter of the assessable boys and nearly two-thirds of the assessable girls showed evidence of endocrine defect, quite apart from those who were merely unusually fat. 11. By distinguishing these two groups of children from a third group of constitutionally "normal," an attempt has been made to see whether there is any correlation between evident endocrine defect and such characteristics as bilateral affection, delayed epiphysial maturation, a history of relevant injury and its nature, and sudden or gradual epiphysial slipping. 12. No relationship was established between any of these characteristics and endocrine type: bilateral affection was no commoner in the endocrine group; delayed maturation was not demonstrated in either; a history of relevant injury was equally common, and its nature identical, in both; slipping might be sudden or gradual in either indiscriminately. 13. There was a history of seemingly relevant injury in half the patients, and it was much commoner with sudden slipping than with gradual slipping. Sudden slipping was often preceded by symptoms of gradual slipping, or sudden slipping of one epiphysis was sometimes followed by gradual slipping of the other. 14. In gradual slipping the cardinal symptoms were pain and limp, usually starting synchronously and gradually; the pain was usually intermittent and referred much more often to the hip than the knee; the limp was usually continuous. 15. Of signs, demonstrable wasting seemed to be absent as often as present, but shortening was usual. Lateral rotation deformity was usually present, adduction often, and flexion sometimes. In more than a third of the cases limitation of movement was slight enough to be easily missed. 16. The radiographic observations confirmed the seeming widening at the affected epiphysial disc, the greater displacement revealed by the lateral view, and the difficulty of identifying avascular necrosis before collapse. 17. Treatment was delayed in thirty-four cases—a third of the whole; the reasons have been analysed; diagnostic failure was the cause in nineteen. 18. A few cases outside the series have been mentioned briefly because of special points of interest: slipping in gross pituitary disease—in pituitary giantism, and(at the age of thirty-three) in pituitary hypogonadism; slipping with defect of the opposite lower limb—infantile paralysis of the leg, and Legg-Calvé-Perthes disease of the hip; familial affection—slipping in two brothers. 19. The results of treatment in the present cases, supplemented by others, have been studied by Dr John Hall and related to some of the clinical features. His paper appears separately