Advances in hip arthroscopy have renewed interest in the ligamentum teres. Considered by many to be a developmental vestige, it is now recognised as a significant potential source of pain and mechanical symptoms arising from the hip joint. Despite improvements in imaging, arthroscopy remains the optimum method of diagnosing lesions of the ligamentum teres. Several biological or mechanical roles have been proposed for the ligament. Unless these are disproved, the use of surgical procedures that sacrifice the ligamentum teres, as in surgical dislocation of the hip, should be carefully considered. This paper provides an update on the development, structure and function of the ligamentum teres, and discusses associated clinical implications

Primary giant-cell tumour of soft tissue arising in the ligamentum teres has not been previously described. We report a case of such a tumour in a 46-year-old woman. The lesion was only detected at the time of hip arthroscopy despite pre-operative MRI being performed. It was successfully excised arthroscopically with resolution of the symptoms

Hip arthrography was performed in 19 patients in the initial stage of Perthes' disease. Sphericity and subluxation were measured and it was found that subluxation was independent of the femoral head deformity. We therefore tried to identify the cause of early subluxation: in seven patients a swollen ligamentum teres was thought to be responsible, and was associated with medial pooling of the contrast medium. A swollen ligamentum teres was seen in another seven cases; the other five arthrograms were normal. These findings were further clarified by enhanced CT scans, which confirmed that ligament swelling may be an important cause of early subluxation

Femoroacetabular impingement causes groin pain and decreased athletic performance in active adults. This bony conflict may result in femoroacetabular subluxation if of sufficient magnitude. The ligamentum teres has recently been reported to be capable of withstanding tensile loads similar to that of the anterior cruciate ligament, and patents with early subluxation of the hip may become dependent on the secondary restraint that is potentially provided by the ligamentum teres. Rupture of the ligamentum may thus cause symptomatic hip instability during athletic activities. An arthroscopic reconstruction of the ligamentum teres using iliotibial band autograft was performed in an attempt to restore this static stabiliser in a series of four such patients. Early clinical results have been promising. The indications, technique and early outcomes of this procedure are discussed

Our understanding of the origin of hip pain in degenerative disorders of the hip, including primary osteoarthritis, avascular necrosis and femoroacetabular impingement (FAI), is limited. We undertook a histological investigation of the nociceptive innervation of the acetabular labrum, ligamentum teres and capsule of the hip, in order to prove pain- and proprioceptive-associated marker expression. These structures were isolated from 57 patients who had undergone elective hip surgery (44 labral samples, 33 ligamentum teres specimens, 34 capsular samples; in 19 patients all three structures were harvested). A total of 15 000 histological sections were prepared that were investigated immunohistochemically for the presence of protein S-100, 68 kDa neurofilament, neuropeptide Y, nociceptin and substance P. The tissues were evaluated in six representative areas. Within the labrum, pain-associated free nerve ending expression was located predominantly at its base, decreasing in the periphery. In contrast, the distribution within the ligamentum teres showed a high local concentration in the centre. The hip capsule had an almost homogeneous marker expression in all investigated areas. This study showed characteristic distribution profiles of nociceptive and pain-related nerve fibres, which may help in understanding the origin of hip pain. Cite this article: Bone Joint J 2013;95-B:770–6

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

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty. Cite this article: Bone Joint J 2015; 97-B:484–91

Aims. This study reports mid-term outcomes after periacetabular osteotomy (PAO) exclusively in a borderline hip dysplasia (BHD) population to provide a contrast to published outcomes for arthroscopic surgery of the hip in BHD. Methods. We identified 42 hips in 40 patients treated between January 2009 and January 2016 with BHD defined as a lateral centre-edge angle (LCEA) of ≥ 18° but < 25°. A minimum five-year follow-up was available. Patient-reported outcomes (PROMs) including Tegner score, subjective hip value (SHV), modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed. The following morphological parameters were evaluated: LCEA, acetabular index (AI), α angle, Tönnis staging, acetabular retroversion, femoral version, femoroepiphyseal acetabular roof index (FEAR), iliocapsularis to rectus femoris ratio (IC/RF), and labral and ligamentum teres (LT) pathology. Results. The mean follow-up was 96 months (67 to 139). The SHV, mHHS, WOMAC, and Tegner scores significantly improved (p < 0.001) at last follow-up. According to SHV and mHHS, there were three hips (7%) with poor results (SHV < 70), three (7%) with a fair score (70 to 79), eight (19%) with good results (80 to 89), and 28 (67%) who scored excellent (> 90) at the last follow-up. There were 11 subsequent operations: nine implant removals due to local irritation, one resection of postoperative heterotopic ossification, and one hip arthroscopy for intra-articular adhesions. No hips were converted to total hip arthroplasty at last follow-up. The presence of preoperative labral lesions or LT lesions did not influence any PROMs at last follow-up. From the three hips that had poor PROMs, two have developed severe osteoarthritis (> Tönnis II), presumably due to surgical overcorrection (postoperative AI < -10°). Conclusion. PAO is reliable in treating BHD with favourable mid-term outcomes. Concomitant LT and labral lesions did not negatively influence outcomes in our cohort. Technical accuracy with avoidance of overcorrection is essential in achieving successful outcomes. Cite this article: Bone Joint J 2023;105-B(7):735–742

1. The results of a study of the characteristics of the vessels found in forty-six human femoral heads during the growth period are described. 2. Of the three different sources of blood entering the human adult femoral head it was found that from birth to about three to four years the vessels of the ligamentum teres do not contribute to the nourishment of the head. 3. After the fourth year the metaphysial vessels decrease in importance until they finally disappear, leaving the head with only one source of blood through the lateral epiphysial vessels; the ligamentum teres is not yet contributing to the circulation of the head. 4. After about eight or nine years it was found that the vessels of the ligamentum teres contribute to the blood supply of the head while the metaphysial blood flow is still arrested. 5. Finally, at puberty, after a period of activity of the metaphysial vessels, epiphysial fusion takes place, bringing together the three sources of blood characteristic of the adult

1. At necropsy the arterial distribution within the head and neck of the femur was investigated by arteriographic injection in fifty-seven uninjured hips of mostly elderly subjects. 2. Before injection all vessels to the head except for one or more particular groups were divided. 3. The superior retinacular arteries were found to be the most important arterial supply to the head. Through the widely distributed branches of their lateral epiphysial vessels (superior capital) they supplied the superior, medial, central and usually the lateral parts of the head: through anastomoses they could also supply the anterior and posterior segments, the subfovea and the inferior sector, which receive separate contributions. Sometimes the inferior or the lateral connections were defective. 4. The arteries in the ligamentum teres were either absent or unimportant for the head in most subjects. Either the vessels in the ligament never reached the head or they supplied only a limited subfoveal zone. In only one out of sixteen specimens was the whole head injected through the vessels of the ligamentum teres. 5. The inferior retinacular arteries were found to be of subsidiary importance and generally supplied a variable infero-lateral part of the head, particularly posteriorly. In a small number there was an anastomotic supply to other parts of the head, but only in two out of sixteen specimens was nearly all the head injected through these vessels. 6. The regular anastomotic supply from the superior retinacular arteries to the subfovea and to the inferior part of the head was in curious contrast to the infrequent anastomotic filling of the lateral epiphysial arteries from the inferior retinacular or ligamentum teres arteries. 7. Vessels within the femoral neck sometimes supplied the lateral part of the head but never the medial three-quarters. 8. The neck of the femur received important branches from the superior retinacular arteries but only in a small number (15 per cent) was part of it entirely dependent on this supply

1. Loss of osteocytes in the bone trabeculae of the femoral heads of "normal" elderly patients was patchy and distinguishable from that resulting from avascular necrosis after fracture. 2. Changes in the haemopoietic marrow were the earliest and most sensitive indicators of ischaemia, loss of osteocytes rarely being complete until three or four weeks after fracture. 3. In 109 femoral heads removed more than sixteen days after fracture the viability could be determined by histological means. All of these had suffered some damage to the vascular supply but in a number the head remained alive apart from the region of the fracture line. These heads were nourished by the blood vessels of the ligamentum teres and sometimes by retinacular arteries, usually of the inferior group. 4. Some femoral heads became completely necrotic following fracture, others were only partly affected. A variable amount of the subfoveal region commonly remained alive and it was from this site that revascularisation spread into the head. The upper segment of the femoral head least often remained alive and its subchondral region was usually the last to revascularise. 5. In a group of unselected femoral heads a third remained alive following fracture and two-thirds were partly or completely necrotic. 6. Femoral heads which were partly necrotic appeared capable of uniting and completely revascularising, there being invasion of the necrotic bone by vessels from across the fracture line and from the ligamentum teres. This contrasted with the completely necrotic femoral heads described elsewhere in this issue which united but in the absence of proliferation of ligamenturn teres vessels failed to revascularise completely and developed late segmental collapse. 7. Avascular necrosis did not appear to be the sole cause of non-union. 8. Necrotic bone showed no alteration in radiological density. Reossifying bone in areas of revascularisation sometimes caused an absolute increase of radiodensity especially when associated with halted revascularisation. This increase of radiological opacity was the result of deposition of new on dead bone with broadening of the trabeculae. Marrow calcification was minimal. 9. Obliterative sclerosis of venules in the ligamentum teres was found in "normal" patients even in infancy. No thrombosis was seen in the ligaments following fracture but where the femoral heads were completely necrotic and not revascularised the ligaments were often also necrotic. 10. There appeared to be no increase in degenerative changes in the articular cartilage of the femoral heads following fracture compared with fifty elderly controls. Some loss of chondrocytes in the deep zone of the weight-bearing area was found in about a quarter of the femoral heads. In only one head was the cartilage almost completely acellular. An almost normal depth and a smooth contour of the articular cartilage were retained

The technical advances in arthroscopic surgery of the hip, including the improved ability to manage the capsule and gain extensile exposure, have been paralleled by a growth in the number of conditions that can be addressed. This expanding list includes symptomatic labral tears, chondral lesions, injuries of the ligamentum teres, femoroacetabular impingement (FAI), capsular laxity and instability, and various extra-articular disorders, including snapping hip syndromes. With a careful diagnostic evaluation and technical execution of well-indicated procedures, arthroscopic surgery of the hip can achieve successful clinical outcomes, with predictable improvements in function and pre-injury levels of physical activity for many patients. This paper reviews the current position in relation to the use of arthroscopy in the treatment of disorders of the hip. Cite this article: Bone Joint J 2013;95-B:10–19

1 . The arterial pattern and the histological features in the femoral head and neck were studied at necropsy in twenty-five specimens with intracapsular fractures. An improved visual-arteriographic method employing barium sulphate dyed with Prussian blue was used. Twenty-three of the fractures were from a few days to twenty-four weeks old and two were seven and ten years old. Nineteen had been nailed or nail-plated. 2. The results were divided into four groups according to the state of the femoral head. In the first group, four heads were histologically viable and had a normal vascular pattern; in the second group, four showed partial avascular necrosis with part of the head retaining a normal blood supply; in the third group, ten had avascular necrosis in all or most of the head and showed little or no revasculanisation; and in the fourth group, seven showed extensive revascularisation of grossly necrotic heads. Total or subtotal capital necrosis had occurred in 64 per cent and total or partial necrosis in 84 per cent of the specimens. The results indicated that interruption of the retinacular vessels was the cause of gross necrosis; and that in most cases an intact blood supply through the ligamentum teres cannot keep more than a part of the head alive when the other vessels are cut off. Occasionally the ligamentum teres is torn by the nail, or though intact, its blood supply is interrupted. This accounts for completion of avascular necrosis in most cases with total capital necrosis. Viability of the subfoveal area from an intact supply through the ligamentum teres was the main source of revascularisation after capital necrosis. Other sources–from across a uniting fracture line, from growth of soft tissue round the head and neck and from other small viable foci in the head and neck–were much less important and the degree of revascularisation was generally limited. Revascularisation was accompanied by fibrocellular invasion of the marrow, differentiation of cells and the formation of oil cysts whereby the necrotic fat is removed; but bony reconstitution was limited. 3. Six fractures were uniting and another had united by bone making an overall union frequency of 50 per cent considering only the nailed fractures older than two weeks. Four of them (57 per cent) showed total or subtotal capital necrosis. In fractures older than two weeks the frequency of union among the eleven nailed fractures with avascular necrosis was 36 per cent, and it was 100 per cent among the three nailed ones with viable or substantially viable heads. Necrosis of the neck side of the fracture was unrelated to non-union because it soon becomes invaded by fibrovascular tissue and new bone. 4. Fibrosis was the basis of union when the head was dead but examination of older fractures at necropsy is needed to assess the long-term results of revascularisation and union. The clinical desirability or otherwise of capital revascularisation after necrosis also needs to be studied

1. The arterial supply of the upper end of the femur has been studied in twenty-four children and twenty adults. 2. The arterial system was demonstrated by injection of radio-opaque material, with Spalteholz' method of clarification, and histological section of the neck and ligamentum teres. 3. The upper end of the femur is supplied by the nutrient artery of the shaft, the retinacular vessels of the capsule, and the foveolar artery of the ligamentum teres. 4. The retinacular vessels consist of three separate groups: postero-superior, posteroinferior, and anterior. These vessels are the chief supply to the epiphysis and femoral head at all ages. 5. The foveolar artery constitutes a small and subsidiary blood supply to the femoral epiphysis. In this series, it penetrated the cartilaginous or osseous head in 33 per cent. of young specimens and 70 per cent. of adult specimens. The foveolar vessels increase in size with age. 6. The site of the vascular pathology in various lesions of the femoral head is considered

Aims. Several studies have reported the safety and efficacy of subcapital re-alignment for patients with slipped capital femoral epiphysis (SCFE) using surgical dislocation of the hip and an extended retinacular flap. Instability of the hip and dislocation as a consequence of this surgery has only recently gained attention. We discuss this problem with some illustrative cases. Materials and Methods. We explored the literature on the possible pathophysiological causes and surgical steps associated with the risk of post-operative instability and articular damage. In addition, we describe supplementary steps that could be used to avoid these problems. Results. The causes of instability may be divided into three main groups: the first includes causes directly related to SCFE (acetabular labral damage, severe abrasion of the acetabular cartilage, flattening of the acetabular roof and a bell-shaped deformity of the epiphysis); the second, causes not related to the SCFE (acetabular orientation and poor quality of the soft tissues); the third, causes directly related to the surgery (capsulotomy, division of the ligamentum teres, shortening of the femoral neck, pelvi-trochanteric impingement, previous proximal femoral osteotomy and post-operative positioning of the leg). Conclusion. We present examples drawn from our clinical practice, as well as possible ways of reducing the risks of these complications, and of correcting them if they happen. Cite this article: Bone Joint J 2017;99-B:16–21

Objectives. An experimental piglet model induces avascular necrosis (AVN) and deformation of the femoral head but its secondary effects on the developing acetabulum have not been studied. The aim of this study was to assess the development of secondary acetabular deformation following femoral head ischemia. Methods. Intracapsular circumferential ligation at the base of the femoral neck and sectioning of the ligamentum teres were performed in three week old piglets. MRI was then used for qualitative and quantitative studies of the acetabula in operated and non-operated hips in eight piglets from 48 hours to eight weeks post-surgery. Specimen photographs and histological sections of the acetabula were done at the end of the study. . Results. The operated-side acetabula were wider, shallower and misshapen, with flattened labral edges. At eight weeks, increased acetabular cartilage thickness characterised the operated sides compared with non-operated sides (p < 0.001, ANOVA). The mean acetabular width on the operated side was increased (p = 0.015) while acetabular depth was decreased anteriorly (p = 0.007) and posteriorly (p = 0.44). The cartilage was thicker, with delayed acetabular bone formation, and showed increased vascularisation with fibrosis laterally and focal degenerative changes involving chondrocyte hypocellularity, chondrocyte cloning, peripheral pannus formation and surface fibrillation. . Conclusions. We demonstrate that femoral head AVN in the young growing piglet also induced, and was coupled with, secondary malformation in acetabular shape affecting both articular and adjacent pelvic cartilage structure, and acetabular bone. The femoral head model inducing AVN can also be applied to studies of acetabular maldevelopment, which is less well understood in terms of developing hip malformation. Cite this article: Bone Joint Res 2014;3:130–8

1. Two cases of recurrent post-traumatic dislocation of the hip are reported. 2. The literature is reviewed and the rarity of the condition is emphasised. Only twenty-two cases have been previously reported, eleven in adults and eleven in children. 3. The sequence of events leading to recurrent dislocation is not understood but the following important facts emerge. The initial incident could not be distinguished from that causing uncomplicated dislocations. There was a significant delay in reduction in a number of cases. Subsequent dislocations followed minor injury. A large defect in the posterior capsule with a large synovial-lined pouch or false joint was found at operation in both our cases. The ligamentum teres was not seen at operation. The surgeon was unable to redislocate the hips during the operation. 4. In both cases reported here treatment was by excision of the posterior pouch and repair of the capsular defect. 5. Based on the above facts some tentative deductions are made

1. A study of late segmental collapse in twelve femoral heads shows that it may not develop until two and a half years after the fracture. 2. Until the articular surfaces had collapsed the patients usually had no symptoms. The fractures were united and there was no obvious radiographic evidence of ischaemic necrosis. 3. There was histological evidence that the whole of the femoral heads had been necrotic at one time. The term late segmental collapse is more appropriate than late segmental necrosis. 4. The blood vessels of the ligamentum teres played little or no part in revascularisation which, when it occurred, was almost entirely across the fracture line. 5. In only one femoral head was revascularisation approaching completion and apparently continuing. In the other eleven much of the head remained necrotic and the process appeared to have halted. 6. An increase in radiological density was caused by new bone laid down on unresorbed necrotic trabeculae and was most prominent behind the line of revascularisation when the process had halted. 7. Trabecular collapse was evident within dead bone. In ten of the femoral heads it occurred in the subchondral region and in four just beyond the junction of reossified and dead bone. 8. Osteoarthritic changes occurred in the cartilage covering revascularised bone at the periphery of the head, especially when collapse was severe

The successful management of femoral neck fractures is obviously based upon many factors. The forces acting upon the proximal end of the femur are believed to be mainly compressive in nature, and the low-angle nail by stabilising the fully reduced fracture in the line of these forces is held to allow weight bearing to take place. Low-angle nailing is believed to offer many advantages over conventional methods of treatment but only in the presence of stability. Stable reduction is the essential preliminary to any form of treatment, and low-angle fixation with early weight bearing in the absence of stability is regarded as futile. It is suggested that those subcapital separations which follow trivial injury may originate as stress fractures accompanying the process of bone remodelling in the aged, and that many of these fractures may remain unrecognised and heal spontaneously. With rare exceptions, subcapital fractures are regarded as being of the same essential pattern, and their varying radiological appearance is considered to be due to the different degrees of displacement to which they have been subjected. A new classification based on this premise has been suggested. In a series of eighty subcapital fractures the incidence of avascular necrosis was not adversely affected by early weight bearing, but reduction in the extreme valgus position was invariably followed by this disaster. This is probably also true of any malposition in extreme rotation which must stretch and obliterate the vessels in the ligamentum teres. A rough alignment index of reduction was found to provide an almost infallible guide to the prognosis both in regard to union and to avascular change. It may therefore be possible to base prognosis on the quality of reduction before the fixation appliance has been inserted. The unsatisfactory results in those cases apparently destined to non-union or avascular necrosis may then be avoided by alternative means of treatment at an early stage. Whether this will prove to be true must depend upon a much longer experience of low-angle fixation, and, in common with almost every communication on this subject, premature publication must largely offset the value of the present findings

This study attempts to establish the factors on which the prognosis of an intracapsular fracture of the femoral neck depends, and to draw attention to certain causes of non-union and ischaemic necrosis. These factors are of two kinds: those inherent in the fracture, and those produced by the surgeon. The prognosis depends largely on the nature of the fracture. Original displacement and comminution are the factors which have most influence. Fractures of Type IV with severe comminution have mainly contributed to the bad reputation of intracapsular fractures. Accurate reduction and firm fixation are necessary if the best results for the type of fracture are to be expected. Accurate reduction does not mean merely accurate apposition of the fragments. Fixation of the fracture in certain rotational malpositions such as valgus of over 20 degrees and rotation round the long axis of the neck may occlude the only remaining source of blood supply, the vessels of the ligamentum teres. If these vessels remain open they may produce revascularisation in a femoral head deprived of its blood supply. The degree of valgus can easily be measured but it is impossible to detect rotation round the long axis of the neck. In this analysis only two methods of fixation were studied. It is clear that rigid fixation is of great significance, and a nail-plate, though it may not be the ideal method of fixation, is greatly superior to a Smith-Petersen nail introduced in the usual way. From the results of this survey there is no justification for continuing the use of this method except perhaps in Type II fractures. The greater the risk of non-union the more important is the fixation, and this is true of all fractures. This study also has a bearing on the indications for primary prosthetic replacement. If the nature of the fracture and the result of the reduction make it likely that replacement by a prosthesis is going to be the ultimate solution, and if the patient is over seventy years old, it is wiser to do it as a primary measure. Finally it was shown that condensation and collapse of the femoral head are not the only radiological signs of ischaemic necrosis. An earlier sign is flattening of the weight-bearing area, which appears on an average six and a half months after injury, as compared to condensation, which may not be apparent until eighteen months after injury

Aims

Research on hip biomechanics has analyzed femoroacetabular contact pressures and forces in distinct hip conditions, with different procedures, and used diverse loading and testing conditions. The aim of this scoping review was to identify and summarize the available evidence in the literature for hip contact pressures and force in cadaver and in vivo studies, and how joint loading, labral status, and femoral and acetabular morphology can affect these biomechanical parameters.

There has been a marked increase in the number of hip arthroscopies performed over the past 16 years, primarily in the management of femoroacetabular impingement (FAI). Insights into the pathoanatomy of FAI, and high-level evidence supporting the clinical effectiveness of arthroscopy in the management of FAI, have fuelled this trend. Arthroscopic management of labral tears with repair may have superior results compared with debridement, and there is now emerging evidence to support reconstructive options where repair is not possible. In situations where an interportal capsulotomy is performed to facilitate access, data now support closure of the capsule in selective cases where there is an increased risk of postoperative instability. Preoperative planning is an integral component of bony corrective surgery in FAI, and this has evolved to include computer-planned resection. However, the benefit of this remains controversial. Hip instability is now widely accepted, and diagnostic criteria and treatment are becoming increasingly refined. Instability can also be present with FAI or develop as a result of FAI treatment. In this annotation, we outline major current controversies relating to decision-making in hip arthroscopy for FAI.

Cite this article: Bone Joint J 2022;104-B(5):532–540.

Aims

The aim of this study was to evaluate the efficacy of the surgical dislocation approach and modified trapdoor procedure for the treatment of chondroblastoma of the femoral head.

Aims

The aims of this study were to review the surgical technique for a combined femoral head reduction osteotomy (FHRO) and periacetabular osteotomy (PAO), and to report the short-term clinical and radiological results of a combined FHRO/PAO for the treatment of selected severe femoral head deformities.

Aims

In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading.

Aims

To determine the likelihood of achieving a successful closed reduction (CR) of a dislocated hip in developmental dysplasia of the hip (DDH) after failed Pavlik harness treatment We report the rate of avascular necrosis (AVN) and the need for further surgical procedures.

Aims

The aims of this study were to develop an in vivo model of periprosthetic joint infection (PJI) in cemented hip hemiarthroplasty, and to monitor infection and biofilm formation in real-time.

Aims

The consensus is that bipolar hemiarthroplasty (BHA) in allograft-prosthesis composite (APC) reconstruction of the proximal femur following primary tumour resection provides more stability than total hip arthroplasty (THA). However, no comparative study has been performed. In this study, we have compared the outcome and complication rates of these two methods.

Aims

The goal of closed reduction (CR) in the treatment of developmental dysplasia of the hip (DDH) is to achieve and maintain concentricity of the femoral head in the acetabulum. However, concentric reduction is not immediately attainable in all hips and it remains controversial to what degree a non-concentric reduction is acceptable. This prospective study is aimed at investigating the dynamic evolution of the hip joint space after CR in DDH using MRI.

Aims

When the present study was initiated, we changed the treatment for late-detected developmental dislocation of the hip (DDH) from several weeks of skin traction to markedly shorter traction time. The aim of this prospective study was to evaluate this change, with special emphasis on the rate of stable closed reduction according to patient age, the development of the acetabulum, and the outcome at skeletal maturity.

We present our early experience of arthroscopic reduction of the dislocated hip in very young infants with developmental dysplasia of the hip (DDH).

Eight dislocated hips, which had failed attempts at closed reduction, were treated by arthroscopy of the hip in five children with a mean age of 5.8 months (4 to 7). A two-portal technique was used, with a medial sub-adductor portal for a 2.7 mm cannulated system with a 70° arthroscope and an anterolateral portal for the instruments. Following evaluation of the key intra-articular structures, the hypertrophic ligamentum teres and acetabular pulvinar were resected, and a limited release of the capsule was performed prior to reduction of the hip. All hips were reduced by a single arthroscopic procedure, the reduction being confirmed on MRI scan. None of the hips had an inverted labrum. The greatest obstacle to reduction was a constriction of the capsule. At a mean follow-up of 13.2 months (9 to 24), all eight hips remained stable. Three developed avascular necrosis. The mean acetabular index decreased from 35.5° (30° to 40°) pre-operatively to 23.3° (17° to 28°).

This study demonstrates that arthroscopic reduction is feasible using two standardised portals. Longer follow-up studies are necessary to evaluate the functional results.

The purpose of this study was to determine patient-reported outcomes of patients with mild to moderate developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) undergoing arthroscopy of the hip in the treatment of chondrolabral pathology. A total of 28 patients with a centre-edge angle between 15° and 19° were identified from an institutional database. Their mean age was 34 years (18 to 53), with 12 female and 16 male patients. All underwent labral treatment and concomitant correction of FAI. There were nine reoperations, with two patients requiring revision arthroscopy, two requiring periacetabular osteotomy and five needing total hip arthroplasty.

Patients who required further major surgery were more likely to be older, male, and to have more severe DDH with a larger alpha angle and decreased joint space.

At a mean follow-up of 42 months (24 to 89), the mean modified Harris hip score improved from 59 (20 to 98) to 82 (45 to 100; p < 0.001). The mean Western Ontario and McMaster Universities Osteoarthritis Index score improved from 30 (1 to 61) to 16 (0 to 43; p < 0.001). Median patient satisfaction was 9.0/10 (1 to 10). Patients reported excellent improvement in function following arthroscopy of the hip.

This study shows that with proper patient selection, arthroscopy of the hip can be successful in the young patient with mild to moderate DDH and FAI.

Cite this article: Bone Joint J 2015;97-B:1316–21.

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.

This review describes the development of arthroscopy of the hip over the past 15 years with reference to patient assessment and selection, the technique, the conditions for which it is likely to prove useful, the contraindications and complications related to the procedure and, finally, to discuss possible developments in the future.

Hip arthroscopy is particularly attractive in children as it confers advantages over arthrotomy or open surgery, such as shorter recovery time and earlier return to activity. Developments in surgical technique and arthroscopic instrumentation have enabled extension of arthroscopy of the hip to this age group. Potential challenges in paediatric and adolescent hip arthroscopy include variability in size, normal developmental change from childhood to adolescence, and conditions specific to children and adolescents and their various consequences. Treatable disorders include the sequelae of traumatic and sports-related hip joint injuries, Legg–Calve–Perthes’ disease and slipped capital femoral epiphysis, and the arthritic and septic hip. Intra-articular abnormalities are rarely isolated and are often associated with underlying morphological changes.

This review presents the current concepts of hip arthroscopy in the paediatric and adolescent patient, covering clinical assessment and investigation, indications and results of the experience to date, as well as technical challenges and future directions.

We have reviewed the current literature to compare the results of surgery aimed to repair or debride a damaged acetabular labrum. We identified 28 studies to be included in the review containing a total of 1631 hips in 1609 patients. Of these studies 12 reported a mean rate of good results of 82% (from 67% to 100%) for labral debridement. Of the 16 studies that reported a combination of debridement and re-attachment, five reported a comparative outcome for the two methods, four reported better results with re-attachment and one study did not find any significant difference in outcomes. Due to the heterogeneity of the studies it was not possible to perform a meta-analysis or draw accurate conclusions. Confounding factors in the studies include selection bias, use of historical controls and high rates of loss of follow-up.

It seems logical to repair an unstable tear in a good quality labrum with good potential to heal in order potentially to preserve its physiological function. A degenerative labrum on the other hand may be the source of discomfort and its preservation may result in persistent pain and the added risk of failure of re-attachment. The results of the present study do not support routine refixation for all labral tears.

Cite this article: Bone Joint J 2014;96-B:24–30.

Objectives

There are several reports clarifying successful results following open reduction using Ludloff’s medial approach for congenital (CDH) or developmental dislocation of the hip (DDH). This study aimed to reveal the long-term post-operative course until the period of hip-joint maturity after the conventional surgical treatments.

The benefit of arthroscopy of the hip in the treatment of femoroacetabular impingement (FAI) in terms of quality of life (QoL) has not been reported. We prospectively collected data on 612 patients (257 women (42%) and 355 men (58%)) with a mean age at the time of surgery of 36.7 years (14 to 75) who underwent arthroscopy of the hip for FAI under the care of a single surgeon. The minimum follow-up was one year (mean 3.2 years (1 to 7)). The responses to the modified Harris hip score were translated using the Rosser Index Matrix in order to provide a QoL score. The mean QoL score increased from 0.946 (-1.486 to 0.995) to 0.974 (0.7 to 1) at one year after surgery (p < 0.001). The mean QoL score in men was significantly higher than in women, both before and one year after surgery (both p < 0.001). However, the mean change in the QoL score was not statistically different between men and women (0.02 (-0.21 to 0.27) and 0.04 (-0.16 to 0.87), respectively; p = 0.12). Linear regression analysis revealed that the significant predictors of a change in QoL score were pre-operative QoL score (p < 0.001) and gender (p = 0.04). The lower the pre-operative score, the higher the gain in QoL post-operatively (ρ = -0.66; p < 0.001). One year after surgery the QoL scores in the 612 patients had improved in 469 (76.6%), remained unchanged in 88 (14.4%) and had deteriorated in 55 (9.0%).

The bicompartmental acetabulum is one of the morphological changes which may be seen in children with Legg-Calvé-Perthes’ disease. Three-dimensional CT and MRI were used to analyse the detailed morphology of the acetabulum with special reference to its inner surface, in 16 patients with Perthes’ disease and a bicompartmental acetabulum.

The bicompartmental appearance was seen on the coronal plane image through the acetabular fossa. The lunate surface was seen to grow laterally resulting in an increased mediolateral thickness of the triradiate cartilage. On the horizontal plane images, the acetabular fossa had deepened and had a distinct prominence at its posterior border. The combination of these morphological changes resulted in a bicompartmental appearance on plain radiography. Acetabular bicompartmentalisation appears to be the result of an imbalance of growth between the cartilage-covered lunate surface and the cartilage-devoid acetabular fossa.

We investigated the incidence and risk factors for the development of avascular necrosis (AVN) of the femoral head in the course of treatment of children with cerebral palsy (CP) and dislocation of the hip. All underwent open reduction, proximal femoral and Dega pelvic osteotomy. The inclusion criteria were: a predominantly spastic form of CP, dislocation of the hip (migration percentage, MP > 80%), Gross Motor Function Classification System, (GMFCS) grade IV to V, a primary surgical procedure and follow-up of > one year.

There were 81 consecutive children (40 girls and 41 boys) in the study. Their mean age was nine years (3.5 to 13.8) and mean follow-up was 5.5 years (1.6 to 15.1). Radiological evaluation included measurement of the MP, the acetabular index (AI), the epiphyseal shaft angle (ESA) and the pelvic femoral angle (PFA). The presence and grade of AVN were assessed radiologically according to the Kruczynski classification.

Signs of AVN (grades I to V) were seen in 79 hips (68.7%). A total of 23 hips (18%) were classified between grades III and V.

Although open reduction of the hip combined with femoral and Dega osteotomy is an effective form of treatment for children with CP and dislocation of the hip, there were signs of avascular necrosis in about two-thirds of the children. There was a strong correlation between post-operative pain and the severity of the grade of AVN.

Cite this article: Bone Joint J 2015;97-B:270–6.

Aims

The number of patients undergoing arthroscopic surgery of the hip has increased significantly during the past decade. It has now become an established technique for the treatment of many intra- and extra-articular conditions affecting the hip. However, it has a steep learning curve and is not without the risk of complications. The purpose of this systematic review was to determine the prevalence of complications during and following this procedure.

We reviewed the clinical outcome of arthroscopic femoral osteochondroplasty for cam femoroacetabular impingement performed between August 2005 and March 2009 in a series of 40 patients over 60 years of age. The group comprised 26 men and 14 women with a mean age of 65 years (60 to 82). The mean follow-up was 30 months (12 to 54).

The mean modified Harris hip score improved by 19.2 points (95% confidence interval 13.6 to 24.9; p < 0.001) while the mean non-arthritic hip score improved by 15.0 points (95% confidence interval 10.9 to 19.1, p < 0.001). Seven patients underwent total hip replacement after a mean interval of 12 months (6 to 24 months) at a mean age of 63 years (60 to 70). The overall level of satisfaction was high with most patients indicating that they would undergo similar surgery in the future to the contralateral hip, if indicated. No serious complications occurred.

Arthroscopic femoral osteochondroplasty performed in selected patients over 60 years of age, who have hip pain and mechanical symptoms resulting from cam femoroacetabular impingement, is beneficial with a minimal risk of complications at a mean follow-up of 30 months.

Aims

Despite the presence of screening programmes, infants continue to present with late developmental dysplasia of the hip (DDH), the impact of which is significant. The aim of this study was to assess infants with late presenting dislocation of the hip despite universal clinical neonatal and selective ultrasound screening.

Arthroscopy of the native hip is an established diagnostic and therapeutic procedure. Its application in the symptomatic replaced hip is still being explored. We describe the use of arthroscopy of the hip in 24 symptomatic patients following total hip replacement, resurfacing arthroplasty of the hip and partial resurfacing (study group), and compared it with arthroscopy of the native hip in 24 patients (control group). A diagnosis was made or confirmed at arthroscopy in 23 of the study group and a therapeutic arthroscopic intervention resulted in relief of symptoms in ten of these. In a further seven patients it led to revision hip replacement. In contrast, arthroscopy in the control group was diagnostic in all 24 patients and the resulting arthroscopic therapeutic intervention provided symptomatic relief in 21.

The mean operative time in the study group (59.7 minutes (35 to 93)) was less than in the control group (71 minutes (40 to 100), p = 0.04) but the arthroscopic approach was more difficult in the arthroplasty group. We suggest that arthroscopy has a role in the management of patients with a symptomatic arthroplasty when other investigations have failed to provide a diagnosis.

In late developmental dysplasia of the hip in childhood, the deformed dysplastic acetabulum is malaligned and has lost its shape due to pressure from the subluxed femoral head. The outer part of the acetabulum involves the upper part of the original acetabulum, thereby giving a bipartite appearance. A clear edge separates the outer from inner part which represents the lower part of the original acetabulum and has no direct contact with the femoral head.

Combined pelvic osteotomy (CPO) using a Lance acetabuloplasty with either a Salter or a Pemberton procedure restores the original shape and realigns the acetabulum. A total of 20 children (22 hips), with a mean age of 46 months (28 to 94) at primary operation underwent CPO with follow-up for between 12 and 132 months.

In each case concentric stable reduction with good acetabular cover was achieved and maintained throughout the period of follow-up.

Aims

This study compared the long-term results following Salter osteotomy and Pemberton acetabuloplasty in children with developmental dysplasia of the hip (DDH). We assessed if there was a greater increase in pelvic height following the Salter osteotomy, and if this had a continued effect on pelvic tilt, lumbar curvature or functional outcomes.

The acetabular labrum is a soft-tissue structure which lines the acetabular rim of the hip joint. Its role in hip joint biomechanics and joint health has been of particular interest over the past decade. In normal hip joint biomechanics, the labrum is crucial in retaining a layer of pressurised intra-articular fluid for joint lubrication and load support/distribution. Its seal around the femoral head is further regarded as a contributing to hip stability through its suction effect. The labrum itself is also important in increasing contact area thereby reducing contact stress. Given the labrum’s role in normal hip joint biomechanics, surgical techniques for managing labral damage are continuously evolving as our understanding of its anatomy and function continue to progress. The current paper aims to review the anatomy and biomechanical function of the labrum and how they are affected by differing surgical techniques.

Take home message: The acetabular labrum plays a critical role in hip function and maintaining and restoring its function during surgical intervention remain an essential goal.

Cite this article: Bone Joint J 2016;98-B:730–5.

Objective

Hip arthroscopy in the setting of hip dysplasia is controversial in the orthopaedic community, as the outcome literature has been variable and inconclusive. We hypothesise that outcomes of hip arthroscopy may be diminished in the setting of hip dysplasia, but outcomes may be acceptable in milder or borderline cases of hip dysplasia.

We inserted an electrode up the femoral neck into the femoral head of ten patients undergoing a metal-on-metal hip resurfacing arthroplasty through a posterior surgical approach and measured the oxygen concentration during the operation. In every patient the blood flow was compromised during surgery, but the extent varied. In three patients, the oxygen concentration was zero at the end of the procedure. The surgical approach caused a mean 60% drop (p < 0.005) in oxygen concentration while component insertion led to a further 20% drop (p < 0.04). The oxygen concentration did not improve significantly on wound closure. This study demonstrates that during hip resurfacing arthroplasty, patients experience some compromise to their femoral head blood supply and some have complete disruption.

There is a high risk of the development of avascular necrosis of the femoral head and nonunion after the treatment of displaced subcapital fractures of the femoral neck in patients aged < 50 years. We retrospectively analysed the results following fixation with two cannulated compression screws and a vascularised iliac bone graft. We treated 18 women and 16 men with a mean age of 38.5 years (20 to 50) whose treatment included the use of an iliac bone graft based on the ascending branch of lateral femoral circumflex artery. There were 20 Garden grade III and 14 grade IV fractures. Clinical and radiological outcomes were evaluated. The mean follow-up was 5.4 years (2 to 10). In 30 hips (88%) union was achieved at a mean of 4.4 months (4 to 6). Nonunion occurred in four hips (12%) and these patients had a mean age of 46.5 years (42 to 50) and underwent revision to a hip replacement six months after operation. The time to union was dependent on age with younger patients achieving earlier union (p < 0.001). According to the Harris hip score which was available for 27 of the 30 hips with satisfactory union, excellent results were obtained in 15 (score ≥ 90 points), fair in ten (score 80 to 90 points), and poor in two hips (≤ 80 points). One patient aged 48 years developed avascular necrosis of femoral head six years after operation and underwent total hip replacement.

The management of displaced subcapital fractures of the femoral neck, in patients aged <  50 years, with two cannulated compression screws and an iliac bone graft based on the ascending branch of lateral femoral circumflex artery, gives satisfactory results with a low rate of complication including avascular necrosis and nonunion.

Cite this article: Bone Joint J 2014;96-B:1024–8.

Few studies have examined the order in which a spinal osteotomy and total hip replacement (THR) are to be performed for patients with ankylosing spondylitis. We have retrospectively reviewed 28 consecutive patients with ankylosing spondylitis who underwent both a spinal osteotomy and a THR from September 2004 to November 2012. In the cohort 22 patients had a spinal osteotomy before a THR (group 1), and six patients had a THR before a spinal osteotomy (group 2). The mean duration of follow-up was 3.5 years (2 to 9). The spinal sagittal Cobb angle of the vertebral osteotomy segment was corrected from a pre-operative kyphosis angle of 32.4 (SD 15.5°) to a post-operative lordosis 29.6 (SD 11.2°) (p < 0.001). Significant improvements in pain, function and range of movement were observed following THR. In group 2, two of six patients had an early anterior dislocation. The spinal osteotomy was performed two weeks after the THR. At follow-up, no hip has required revision in either group. Although this non-comparative study only involved a small number of patients, given our experience, we believe a spinal osteotomy should be performed prior to a THR, unless the deformity is so severe that the procedure cannot be performed.

Cite this article: Bone Joint J 2014;96-B:360–5.

Young adults with hip pain secondary to femoroacetabular impingement (FAI) are rapidly being recognised as an important cohort of orthopaedic patients. Interest in FAI has intensified over the last decade since its recognition as a precursor to arthritis of the hip and the number of publications related to the topic has increased exponentially in the last decade. Although not all patients with abnormal hip morphology develop osteoarthritis (OA), those with FAI-related joint damage rapidly develop premature OA. There are no explicit diagnostic criteria or definitive indications for surgical intervention in FAI. Surgery for symptomatic FAI appears to be most effective in younger individuals who have not yet developed irreversible OA. The difficulty in predicting prognosis in FAI means that avoiding unnecessary surgery in asymptomatic individuals, while undertaking intervention in those that are likely to develop premature OA poses a considerable dilemma. FAI treatment in the past has focused on open procedures that carry a potential risk of complications.

Recent developments in hip arthroscopy have facilitated a minimally invasive approach to the management of FAI with few complications in expert hands. Acetabular labral preservation and repair appears to provide superior results when compared with debridement alone. Arthroscopic correction of structural abnormalities is increasingly becoming the standard treatment for FAI, however there is a paucity of high-level evidence comparing open and arthroscopic techniques in patients with similar FAI morphology and degree of associated articular cartilage damage. Further research is needed to develop an understanding of the natural course of FAI, the definitive indications for surgery and the long-term outcomes.

Cite this article: Bone Joint J 2013;95-B, Supple A:26–30.

Proximal femoral resection (PFR) is a proven pain-relieving procedure for the management of patients with severe cerebral palsy and a painful displaced hip. Previous authors have recommended post-operative traction or immobilisation to prevent a recurrence of pain due to proximal migration of the femoral stump. We present a series of 79 PFRs in 63 patients, age 14.7 years (10 to 26; 35 male, 28 female), none of whom had post-operative traction or immobilisation.

A total of 71 hips (89.6%) were reported to be pain free or to have mild pain following surgery. Four children underwent further resection for persistent pain; of these, three had successful resolution of pain and one had no benefit. A total of 16 hips (20.2%) showed radiographic evidence of heterotopic ossification, all of which had formed within one year of surgery. Four patients had a wound infection, one of which needed debridement; all recovered fully. A total of 59 patients (94%) reported improvements in seating and hygiene.

The results are as good as or better than the historical results of using traction or immobilisation. We recommend that following PFR, children can be managed without traction or immobilisation, and can be discharged earlier and with fewer complications. However, care should be taken with severely dystonic patients, in whom more extensive femoral resection should be considered in combination with management of the increased tone.

Cite this article: Bone Joint J 2014; 96-B:701–6.

We present the case of a young male patient with inferior dislocation of the hip and postulate a possible mechanism for this extremely rare injury.

The April 2012 Children’s orthopaedics Roundup³⁶⁰ looks at osteonecrosis of the femoral head and surgery for dysplasia, femoral head blood flow during surgery, femoroacetabular impingement and sport in adolescence, the Drehmann sign, a predictive algorithm for septic arthritis, ACL reconstruction and arthrofibrosis in children, spinal cord monitoring for those less than four years old, arthroereisis for the flexible flat foot, fixing the displaced lateral humeral fracture, and mobile phones and inclinometer applications

We performed a series of 16 anatomical dissections on Caucasian cadaver material to determine the surgical anatomy of the medial femoral circumflex artery (MFCA) and its anastomoses. These confirmed that the femoral head receives its blood supply primarily from the MFCA via a group of posterior superior nutrient arteries and the posterior inferior nutrient artery. In terms of anastomoses that may also contribute to the blood supply, the anastomosis with the inferior gluteal artery, via the piriformis branch, is the most important. These dissections provide a base of knowledge for further radiological studies on the vascularity of the normal femoral head and its vascularity after dislocation of the hip.

We present our experience of the modified Dunn procedure in combination with a Ganz surgical dislocation of the hip to treat patients with severe slipped capital femoral epiphysis (SCFE). The aim was to prospectively investigate whether this technique is safe and reproducible. We assessed the degree of reduction, functional outcome, rate of complications, radiological changes and range of movement in the hip. There were 28 patients with a mean follow-up of 38.6 months (24 to 84). The lateral slip angle was corrected by a mean of 50.9° (95% confidence interval 44.3 to 57.5). The mean modified Harris hip score at the final follow-up was 89.1 (sd 9.0) and the mean Non-Arthritic Hip score was 91.3 (sd 9.0). Two patients had proven pre-existing avascular necrosis and two developed the condition post-operatively. There were no cases of nonunion, implant failure, infection, deep-vein thrombosis or heterotopic ossification. The range of movement at final follow-up was nearly normal. This study adds to the evidence that the technique of surgical dislocation and anatomical reduction is safe and reliable in patients with SCFE.

Cite this article: Bone Joint J 2013;95-B:424–9.

Traumatic posterior dislocation of the hip associated with a fracture of the posterior acetabular wall and of the neck of the femur is a rare injury. A 29-year-old man presented at a level 1 trauma centre with a locked posterior dislocation of the right hip, with fractures of the femoral neck and the posterior wall of the acetabulum after a bicycle accident. An attempted closed reduction had failed. This case report describes in detail the surgical management and the clinical and radiological outcome. Open reduction and fixation with preservation of the intact retinaculum was undertaken within five hours of injury with surgical dislocation of the hip and a trochanteric osteotomy. Two years after operation the function of the injured hip was good. Plain radiographs and MR scans showed early signs of osteoarthritis with some loss of joint space but no evidence of avascular necrosis. The patient had begun skiing and hiking again.

The combination of fractures of the neck of the femur and of the posterior wall of the acetabulum hampers closed reduction of a posterior dislocation of the hip. Surgical dislocation of the hip with trochanteric flip osteotomy allows controlled open reduction of the fractures, with inspection of the hip joint and preservation of the vascular supply.

There have been considerable recent advances in the understanding and management of femoroacetabular impingement and associated labral and chondral pathology. We have developed a classification system for acetabular chondral lesions. In our system, we use the six acetabular zones previously described by Ilizaliturri et al. The cartilage is then graded on a scale of 0 to 4 as follows: grade 0, normal articular cartilage lesions; grade 1, softening or wave sign; grade 2, cleavage lesion; grade 3, delamination; and grade 4, exposed bone. The site of the lesion is further classed as A, B or C based on whether the lesion is less than one-third of the distance from the acetabular rim to the cotyloid fossa, one-third to two-thirds of the same distance and greater than two-thirds of the distance, respectively. In order to validate the classification system, six surgeons graded ten video recordings of hip arthroscopy.

Our findings showed a high intra-observer reliability of the classification system with an intraclass correlation coefficient of 0.81 and a high interobserver reliability with an intraclass correlation coefficient of 0.88.

We have developed a simple reproducible classification system for lesions of the acetabular cartilage, which it is hoped will allow standardised documentation to be made of damage to the articular cartilage, particularly that associated with femoroacetabular impingement.

Between June 2001 and November 2008 a modified Dunn osteotomy with a surgical hip dislocation was performed in 30 hips in 28 patients with slipped capital femoral epiphysis. Complications and clinical and radiological outcomes after a mean follow-up of 3.8 years (1.0 to 8.5) were documented. Subjective outcome was assessed using the Harris hip score and the Western Ontario and McMaster Universities osteoarthritis index questionnaire.

Anatomical or near-anatomical reduction was achieved in all cases. The epiphysis in one hip showed no perfusion intra-operatively and developed avascular necrosis. There was an excellent outcome in 28 hips. Failure of the implants with a need for revision surgery occurred in four hips.

Anatomical reduction can be achieved by this technique, with a low risk of avascular necrosis. Cautious follow-up is necessary in order to avoid implant failure.

We undertook a prospective pilot study to determine whether arthroscopic surgery through the central compartment of the hip was effective in the management of a snapping iliopsoas tendon. Seven patients were assessed pre-operatively and at three, six, 12 and 24 months after operation. This included the assessment of pain on a visual analogue scale (VAS) and function using the modified Harris hip score.

All the patients had resolution of snapping post-operatively and this persisted at follow-up at two years. The mean VAS score for pain fell from 7.7 (6 to 10) pre-operatively to 4.3 (0 to 10) by three months (p = 0.051), and to 3.6 (1 to 8) (p = 0.015), 2.4 (0 to 8) (p = 0.011) and 2.4 (0 to 8) (p = 0.011) by six, 12 and 24 months, respectively. The mean modified Harris hip score increased from 56.1 (13.2 to 84.7) pre-operatively to 88.4 (57.2 to 100) at one year (p = 0.018) and to 87.9 (49.5 to 100) at two years (p = 0.02). There were no complications and no weakness occurred in the musculature around the hip.

Our findings suggest that this treatment is effective and would support the undertaking of a larger study comparing this procedure with other methods of treatment.

We describe a patient with cerebral palsy, of normal intelligence, who could not walk but who by the age of 16 had been successfully managed with a staged bilateral total hip arthroplasty using a constrained liner.

In patients with severe quadriplegic cerebral palsy and painful hip dislocation proximal femoral resection arthroplasty can reduce pain, but the risk of heterotopic ossification is significant. We present a surgical technique of autologous capping of the femoral stump in order to reduce this risk, using the resected femoral head as the graft.

A retrospective study of 31 patients (43 hips) who had undergone proximal femoral resection arthroplasty with (29 hips) and without autologous capping (14 hips) was undertaken. Heterotopic ossification was less frequent in patients with autologous capping, and a more predictable pattern of bony overgrowth was found.

For a selected group of non-ambulatory patients with long-standing painful dislocation of the hip, we recommend femoral resection arthroplasty over more complicated reconstructive operations. The risk of heterotopic ossification, which is a major disadvantage of this operation, is reduced by autologous capping.

The Salter innominate osteotomy has been used successfully for many years in the treatment of developmental dysplasia of the hip. One of its main drawbacks is the need for internal fixation with pins and their subsequent removal. We describe a modification of this osteotomy that does not require pin fixation and secondary removal. We retrospectively reviewed 114 hips in 94 patients who had been operated on by a single surgeon. An oblique rather than the original horizontal osteotomy was used without internal fixation. There were 80 female and 14 male patients. The mean age at operation was 25 months (18 to 84) and the mean follow-up was 30 months (12 to 88). Most patients required additional open reduction and capsuloplasty. The mean pre-operative acetabular index was 37.9° (24° to 54°), which decreased to 19.9° (7° to 29°) in the immediate post-operative period, and improved to 14.6° (5° to 25°) at the final follow-up (student’s t-test, p < 0.0001).

We believe that by changing the direction of the osteotomy line, it is possible to avoid pin fixation. The radiological outcomes are comparable to those of the original technique, but longer follow-up will be necessary.

In order to determine the potential for an internervous safe zone, 20 hips from human cadavers were dissected to map out the precise pattern of innervation of the hip capsule. The results were illustrated in the form of a clock face. The reference point for measurement was the inferior acetabular notch, representing six o’clock. Capsular branches from between five and seven nerves contributed to each hip joint, and were found to innervate the capsule in a relatively constant pattern. An internervous safe zone was identified anterosuperiorly in an arc of 45° between the positions of one o’clock and half past two.

Our study shows that there is an internervous zone that could be safely used in a capsule-retaining anterior, anterolateral or lateral approach to the hip, or during portal placement in hip arthroscopy.

We treated 15 hips (15 patients) with developmental dysplasia by a single-stage combination of open reduction through a medial approach and innominate osteotomy. The mean age of the patients at the time of operation was 20 months (13 to 30). The mean follow-up period was 9.6 years (4 to 14).

At the final follow-up, 14 hips were assessed clinically as excellent and one hip as good. Radiologically, ten hips were rated as class I, four as class II and one as class III according to the criteria of Severin. No avascular necrosis was seen. No patient required subsequent surgery. Our results indicate that satisfactory results can be obtained with the single-stage combination of open reduction by the medial approach and innominate osteotomy for developmental dysplasia of the hip in a selected group of children older than 12 months. To our knowledge, no similar combined technique has been previously reported.

The outcome of one-stage bilateral open reduction through a medial approach for the treatment of developmental dysplasia of the hip in children under 18 months was studied in 23 children, 18 girls and five boys. Their mean age at operation was 10.1 months (6 to 17) and the mean follow-up was 5.4 years (3 to 8).

Acceptable clinical and radiological results were achieved in 44 (95.7%) and 43 (93.5%) of 46 hips, respectively. Excellent results were significantly evident in patients younger than 12 months, those who did not require acetabuloplasty, those whose ossific nucleus had appeared, and in those who did not develop avascular necrosis.

One-stage bilateral medial open reduction avoids the need for separate procedures on the hips and has the advantages of accelerated management and shorter immobilisation and rehabilitation than staged operations.

In spite of extensive accounts describing the blood supply to the femoral head, the prediction of avascular necrosis is elusive. Current opinion emphasises the contributions of the superior retinacular artery but may not explain the clinical outcome in many situations, including intramedullary nailing of the femur and resurfacing of the hip. We considered that significant additional contribution to the vascularity of the femoral head may exist. A total of 14 fresh-frozen hips were dissected and the medial circumflex femoral artery was cannulated in the femoral triangle. On the test side, this vessel was ligated, with the femoral head receiving its blood supply from the inferior vincular artery alone. Gadolinium contrast-enhanced MRI was then performed simultaneously on both control and test specimens. Polyurethane was injected, and gross dissection of the specimens was performed to confirm the extraosseous anatomy and the injection of contrast. The inferior vincular artery was found in every specimen and had a significant contribution to the vascularity of the femoral head. The head was divided into four quadrants: medial (0), superior (1), lateral (2) and inferior (3). In our study specimens the inferior vincular artery contributed a mean of 56% (25% to 90%) of blood flow in quadrant 0, 34% (14% to 80%) of quadrant 1, 37% (18% to 48%) of quadrant 2 and 68% (20% to 98%) in quadrant 3. Extensive intra-osseous anastomoses existed between the superior retinacular arteries, the inferior vincular artery and the subfoveal plexus.

The epidemiological data and intra-operative findings from 260 consecutive arthroscopically-diagnosed acetabular labral tears seen over a ten-year period were analysed. Radiographs of 128 of these patients were assessed for dysplasia using established radiological parameters. Patients with acetabular dysplasia were then compared against those without in order to identify any differences in gender, age, the side of the tear, the pattern of the tear, the number of quadrants involved, the quadrant preference and the prevalence of intra-articular comorbidity. Dysplasia was found in 46% (59 of 128) of the hips. No significant differences existed between the dysplastic and non-dysplastic subgroups as regards gender distribution, the side of the lesion, the number of quadrants involved or the distribution of tears among the quadrants. However, tears associated with dysplasia were diagnosed in an older age group, had a different pattern and were associated with a much higher prevalence of osteoarthritis.

We describe a series of 20 patients with ununited fractures of the femoral neck following neglected trauma or failed primary internal fixation who were seen at a mean of 7.5 months (2 to 18) following injury. Open reduction and internal fixation of the fracture was performed in all patients, together with a myoperiosteal flap on the quadratus femoris muscle pedicle.

Union occurred at a mean of 4.9 months (2 to 10) in all patients. The mean follow-up was for 70 months (14 to 144). There was no further progression in six of seven patients with pre-operative radiological evidence of osteonecrosis of the femoral head. One patient had delayed collapse and flattening of the femoral head ten years after union of the fracture, but remained asymptomatic.

This study demonstrates the orthopaedic application of myoperiosteal grafting for inducing osteogenesis in a difficult clinical situation.

Difficulties posed in managing developmental dysplasia of the hip diagnosed late include a high-placed femoral head, contracted soft tissues and a dysplastic acetabulum. A combination of open reduction with femoral shortening of untreated congenital dislocations is a well-established practice. Femoral shortening prevents excessive pressure on the located femoral head which can cause avascular necrosis. Instability due to a coexisting dysplastic shallow acetabulum is common, and so a pelvic osteotomy is performed to achieve a stable and concentric hip reduction. We retrospectively reviewed 15 patients (18 hips) presenting with developmental dysplasia of the hip aged four years and above who were treated by a one-stage combined procedure performed by the senior author. The mean age at operation was five years and nine months (4 years to 11 years). The mean follow-up was six years ten months (2 years and 8 months to 8 years and 8 months). All patients were followed up clinically and radiologically in accordance with McKay’s criteria and the modified Severin classification. According to the McKay criteria, 12 hips were rated excellent and six were good. All but one had a full range of movement. Eight had a limb-length discrepancy of about 1 cm. All were Trendelenburg negative. The modified Severin classification demonstrated four hips of grade IA, six of grade IB, and eight of grade II. One patient had avascular necrosis and one an early subluxation requiring revision.

One-stage correction of congenital dislocation of the hip in an older child is a safe and effective treatment with good results in the short to medium term.

Acetabular dysplasia was produced in 24 immature white rabbits. A rotational acetabular osteotomy was then carried out and radiological and histological studies of the articular cartilage were made.

In the hips which did not undergo osteotomy, radiographs at 26 weeks showed that residual subluxation remained and arthritic changes such as narrowing of the joint space or dislocation were still seen. However, in the operated group there was a remarkable increase in cover, but arthritic changes were not observed. After 24 weeks, the Mankin grading score in the operated group was significantly lower than that in the non-operated group. The latter hips showed an irregular surface of the cartilage, exfoliation and proliferation of synovial tissue. In those undergoing osteotomy, primary cloning of chondrocytes or hypercellularity was seen and at 24 weeks after operation and metaplasia of the cartilage in the fibrous tissue was observed in the boundary between the medial area of the acetabulum and the acetabular fossa.

Over an eight-month period we prospectively enrolled 122 patients who underwent arthroscopic surgery of the hip for femoroacetabular impingement and met the inclusion criteria for this study. Patients with bilateral hip arthroscopy, avascular necrosis and previous hip surgery were excluded. Ten patients refused to participate leaving 112 in the study. There were 62 women and 50 men. The mean age of the patients was 40.6 yrs (95% confidence interval (CI) 37.7 to 43.5). At arthroscopy, 23 patients underwent osteoplasty only for cam impingement, three underwent rim trimming only for pincer impingement, and 86 underwent both procedures for mixed-type impingement. The mean follow-up was 2.3 years (2.0 to 2.9). The mean modified Harris hip score (HHS) improved from 58 to 84 (mean difference = 24 (95% CI 19 to 28)) and the median patient satisfaction was 9 (1 to 10). Ten patients underwent total hip replacement at a mean of 16 months (8 to 26) after arthroscopy.

The predictors of a better outcome were the pre-operative modified HHS (p = 0.018), joint space narrowing ≥ 2 mm (p = 0.005), and repair of labral pathology instead of debridement (p = 0.032).

Hip arthroscopy for femoroacetabular impingement, accompanied by suitable rehabilitation, gives a good short-term outcome and high patient satisfaction.