To investigate the effect of instability on the remodelling of a minor articular surface offset, we created a 0.5 mm coronal step-off of the medial femoral condyle in 12 New Zealand white rabbits and transected the anterior cruciate ligament (ACL). A control group of 12 rabbits had only ACL resection and the opposite knee was used as the non-operated control. The osteoarthritic changes at 6, 12 and 24 weeks after surgery were evaluated histologically. In addition, changes in the immunological detection of 3-B-3(-) and 7-D-4 chondroitin-6-sulphate epitopes were determined because of the previous association of such changes with repair of cartilage and early osteoarthritis. In the instability/step-off group there was rapidly progressing focal degeneration of cartilage on the high side of the defect, not seen in previous step-off studies in stable knees. The rest of the femoral condyles and the tibial plateaux of the instability/step-off group had moderate osteoarthritis similar to that of the instability group. 3-B-3(-) was detectable in the early and the intermediate stages of osteoarthritis but no staining was seen in the severely damaged cartilage zones. Immunoreactivity with 7-D-4 increased as degeneration progressed. Our findings have shown that even a minor surface offset may induce rapid degeneration of cartilage when the stability of the knee is compromised

A total of 90 patients with an isolated rupture of the anterior cruciate ligament (ACL) had a reconstruction using the ipsilateral patellar tendon secured with round-headed cannulated interference screws. Annual review for five years showed three failures of the graft (two traumatic and one atraumatic); none occurred after two years. Ten patients sustained a rupture of the contralateral ACL. At five years, 69% of those with surviving grafts continued to participate in moderate to strenuous activity. Using the International Knee Documentation Committee assessment, 90% reported their knee as being normal or nearly normal and had a median Lysholm knee score of 96 (64 to 100). Most patients (98%) had a pivot shift of grade 0 with the remaining 2% being grade 1; 90% of the group had a Lachman test of grade 0. The incidence of subsequent meniscectomy was similar in the reconstructed joint to that in the contralateral knee. Radiological examination was normal in 63 of 65 patients. Our study supports the view that reconstruction of the ACL is a reliable technique allowing full rehabilitation of the previously injured knee. In the presence of normal menisci there is a low incidence of osteoarthritic change despite continued participation in sporting activity

Recognized anatomic variations that lead to patella instability include patella alta and trochlea dysplasia. Lateralization of the extensor mechanism relative to the trochlea is often considered to be a contributing factor; however, controversy remains as to the degree this contributes to instability and how this should be measured. As the tibial tuberosity-trochlear groove (TT-TG) is one of most common imaging measurements to assess lateralization of the extensor mechanism, it is important to understand its strengths and weaknesses. Care needs to be taken while interpreting the TT-TG value as it is affected by many factors. Medializing tibial tubercle osteotomy is sometimes used to correct the TT-TG, but may not truly address the underlying anatomical problem. This review set out to determine whether the TT-TG distance sufficiently summarizes the pathoanatomy, and if this assists with planning of surgery in patellar instability.

Cite this article: Bone Jt Open 2022;3(3):268–274.

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

Aims

The aim of this prospective study was to assess the long-term clinical, radiological, functional, and quality of life (QoL)-related outcome of patients treated with the synthetic Ligament Advanced Reinforcement System (LARS) device for anterior cruciate ligament (ACL) rupture.

We treated 26 hips (24 consecutive patients) with residual dysplasia by a technique of incomplete triple pelvic osteotomy. The mean age of the patients was 21.6 years. The mean values for the pre-operative centre-edge angle of Wiberg, the refined centre-edge angle, the acetabular angle of Sharp, the modified acetabular angle and femoral head lateralisation were 7.7°, −3.1°, 49.3°, 53.2° and 17.2 mm, respectively. After a mean follow-up of 3.3 years they were 27.0°, 13.0°, 38.9°, 44.3° and 15.9 mm, respectively (p < 0.05). The osteoarthritic grading changed adversely in one hip. The mean pre-operative and latest Harris hip scores were 74.9 and 93.0, respectively (p < 0.05). This technique provides a stable osteotomy with maintenance of the posterior column which allows early mobilisation and minimal internal fixation. The technique is not complex and requires minimal blood transfusion. The use of an image intensifier is not necessary and harvesting of a subcristal bone graft avoids post-operative complications at the donor site

1. The clinical and radiological results of seventy-one osteotomies for primary osteoarthritis of the hip performed with internal fixation have been examined two to eight years after operation. Advanced cases where osteotomy would have been purely a salvage procedure were excluded. 2. The hips were divided into two groups: one in a relatively early and the other in a later intermediate stage of the disease. The two criteria for inclusion in the "early" group were a) fiexion movement of 90 degrees or more, either with the patient conscious or completely relaxed under anaesthesia, and b) no collapse of bone seen in the radiograph. 3. The clinical results show that early osteotomy seldom fails to give relief of pain, which is closely correlated with improved function and a favourable assessment of the operation by the patient. A good range of flexion, not less than 70 degrees and frequently 90 degrees, is retained when the criteria mentioned above obtain. 4. The radiological assessment was based upon examination of the joint space, the cystic appearances and the degree of collapse of bone, if any, as seen in serial films. There was convincing evidence of regression indicating arrest of the arthritic process in 70 per cent of the "early" cases. 5. Regression after osteotomy appears to be a well-defined process which is more commonly observed and more complete when the osteotomy is performed sooner rather than at a later stage of the disease. With few exceptions a good radiological result is associated with a good clinical result. 6. Some of the possible causes of failure are discussed. Osteotomy is more likely to fail if delayed till stiffness is severe and collapse of bone has begun. Large cysts, rapid advance of the disease, and a valgus osteotomy in the presence of lateral subluxation may also prejudice the results. 7. This review offers good support for Nissen's suggestion that in primary osteoarthritis of the hip osteotomy should be performed early, while the joint is still mobile and capable of repair, in order to retain good function. 8. Relief from pain is not the only consideration in deciding when to operate; the prospects of arresting the disease and of stimulating a healing reaction in the disordered cancellous bone and articular cartilage by early osteotomy should always be kept in mind. 9. In many respects the findings of this review are complementary to those of Postel and Vaillant (1962) who reported excellent results from varus osteotomy of Pauwels' type in a series of cases of subluxation of the hip with pain but without frank secondary osteoarthritic change

Aims

We compared the clinical outcomes of curved intertrochanteric varus osteotomy (CVO) with bone impaction grafting (BIG) with CVO alone for the treatment of osteonecrosis of the femoral head (ONFH).

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

Femoroacetabular impingement (FAI) describes abnormal bony contact of the proximal femur against the acetabulum. The term was first coined in 1999; however what is often overlooked is that descriptions of the morphology have existed in the literature for centuries. The aim of this paper is to delineate its origins and provide further clarity on FAI to shape future research.

Aims

Transtrochanteric rotational osteotomy (TRO) is performed for young patients with non-traumatic osteonecrosis of the femoral head (ONFH) to preserve the hip. We aimed to investigate the long-term outcomes and the risk factors for failure 15 years after this procedure.

Aims

The aim of this study was to report the long-term results of rotational acetabular osteotomy (RAO) for symptomatic hip dysplasia in patients aged younger than 21 years at the time of surgery.

Aims

We analyzed the acetabular morphology of Crowe type IV hips using CT data to identify a landmark for the ideal placement of the centre of the acetabular component, as assessed by morphometric geometrical analysis, and its reliability.