Patella alta, Patella type (Wiberg classification), Trochlea sulcus angles for bone and cartilage, The shortest horizontal distance between the most distal part of the vastus medialis obliquis (VMO) muscle to the supra-medial aspect of the patella, Trochlea and patella cartilage thickness (maximum depth), The horizontal distance between the tibial tubercle and the midpoint of the femoral trochlea (TTD), Patella Engagement – represented as the percentage of the patella height that is captured in the trochlea groove when the knee is in full extension, A Discriminant Analysis test for multi-variant analysis was applied to establish the relationship between each bony/soft tissue anatomical variable and the severity/magnitude of patellofemoral subluxation.
This is the first study to establish that patella engagement is related to PFJ subluxation showing that the lower the percentage engagement of the patella in the trochlea, the greater the severity/magnitude of patellofemoral subluxation. The finding provides greater insight into the aetiology and understanding of the mechanism of symptomatic PFJ subluxation.
Inflammatory changes in synovial tissues occur commonly in knee osteoarthritis (OA) and are termed “inflammatory OA”. The pathogenic significance of this inflammatory OA is uncertain. It is also not known whether inflammatory changes in the synovial membrane are reflected in the synovial fluid (SF) and whether the SF contains a similar inflammatory cell infiltrate. This study examined 34 cases of knee joint OA and cytologically and immunohistochemically characterised inflammatory cells in the synovial membrane and SF. Specimens of SF and synovial membrane were taken at the time of knee arthroplasty. All cases of inflammatory OA synovium contained (CD68+) macrophages; several cases also contained a scattered, focally heavy (CD3+) lymphocytic infiltrate and occasional lymphoid aggregates. Inflammatory changes in OA SF reflected this cell composition with numerous CD68+ macrophages and CD3+ lymphocytes being noted in inflammatory OA cases. The SF volume was greater (>
5ml) in cases of inflammatory OA. Non-inflammatory OA knee joints contained very few inflammatory cells, which were mainly macrophages, in both the synovial membrane and SF. Our findings indicate that inflammatory changes in the synovial membrane of OA knee joints are reflected in the SF and that the volume of SF is commonly increased in cases of inflammatory OA. Both macrophages and lymphocytes in the inflammatory infiltrate of knee joint SF may contribute to joint destruction in OA by providing mononuclear phagocyte osteoclast precursors and the production of inflammatory cytokines and growth factors that promote osteoclastogenesis. In conclusion, the cytology of SF and synovitic membrane are similar in inflammatory OA. With knee effusions of greater than 5mls and inflammatory synovitic membrane consideration of total knee arthoplasty in the presence of single compartment disease should be considered because of the risk of further joint destruction.
Cellular mechanisms that account for tumour osteolysis associated with Ewing’s sarcoma are uncertain. Osteoclasts are marrow-derived multinucleated cells that effect tumour osteolysis. Osteoclasts are known to form from macrophages by both receptor activator for nuclear factor κB ligand (RANKL)-dependent and RANKL-independent mechanisms. In this study our aim has been to determine whether tumour-associated macrophages (TAMs) isolated from Ewing’s sarcoma are capable of differentiating into osteoclasts and to characterise the cellular and humoral mechanisms whereby this occurs. TAMs were isolated from two Ewing’s sarcomas and cultured on both coverslips and dentine slices for up to 21 days with soluble RANKL and human macrophage colony stimulating factor (M-CSF). Osteoclast formation from TAMs (CD14+) was evidenced by the formation of tartrate–resistant acid phosphatase and vitronectin receptor-positive multinucleated cells which were capable of carrying out lacunar resorption. This osteoclast formation and resorption was inhibited by the addition of the bisphosphonate, zoledronate. Osteoclast formation was also seen when Ewing’s sarcoma-derived TAMs were cultured with TNF α in the presence of M-CSF. We also found that TC71 Ewing’s sarcoma cells were capable of independently stimulating osteoclast formation through the release of a soluble factor. These results indicate that TAMs in Ewing’s sarcoma are capable of osteoclast differentiation by both RANKL-dependent and RANKL-independent mechanisms and that Ewing’s sarcoma cells produce an osteoclastogenic factor. The role bisphosphonates may play in inhibiting osteoclast formation and osteolysis in Ewing’s sarcoma merits further investigation.
13 presented in the extensor compartment and 2 flexor compartment at the level of the distal radius. All presented with a painless mass. 5 patients with neurological symptoms. 4 involving the post interosseus nerve and 1 radial nerve. MRI was the diagnostic imaging technique of choice, 2 had biopsies where there was atypical imaging features.
All underwent planned marginal excision preserving juxtaposed peripheral nerve. There were no radial, spiral or PIN nerve palsies. One patient presented with PIN palsy had partial resolution of symptoms and function. I wound infection
The management of pathological fractures in children remains controversial. The indications for surgical treatment are unclear and the need for histological diagnosis before or after definitive treatment is not clearly defined. We reviewed retrospectively the records of all patients under the age of 16 years who presented over the past 7 years with a fracture as the first manifestation of bone pathology. There were 26 patients (19 boys and 7 girls) of an average age of 12 years and 2 months (range 4.1–15.8 years). There were 9 cases of fracture through a simple bone cyst, 6 in the humerus and 3 in the femur. In all cases the fracture was treated conservatively initially. Subsequent management included needle biopsy in all, followed by bone marrow injection under the same anaesthetic. The patients suffered a refracture and were treated with flexible intra-medullary nail fixation. There were 5 cases of fibrous dysplasia, of which 2 in the femur, 2 in the tibia and one in the proximal radius. Histological diagnosis was obtained in all cases prior to definitive treatment. This included a locked intra-medullary nail in one patient and flexible nailing in another two. The remaining two patients are still under observation. There were 2 patients with giant cell tumour, 3 patients with aneurysmal bone cyst and one patient with chondroblastoma. Histological diagnosis preceded treatment with curettage and grafting in all these cases. There were 6 patients with malignant primary bone tumour, 1 adamantinoma, 2 osteosarcoma, and 3 with Ewings Sarcoma. The 3 patients with Ewing’s sarcoma involved the femur. One had extensive local disease and early intra-medullary nailing was performed for palliative reasons. The second patient was treated conservatively initially. Definitive surgery was performed after fracture healing and included segmental resection and vascularised fibular graft. The third patient was initially treated elsewhere. She was thought to have a benign lesion and internal fixation with a screw/plate device was performed. Histology from intra-operative specimens confirmed Ewing’s sarcoma. Definitive surgery required extensive resection and prosthetic replacement. The 2 patients with osteosarcoma had fracture of proximal humerus and distal femur. The former was treated by forequarter amputation as there was tumour involvement of brachial plexus and remains AWND at 7 years. The latter had resection and EPR of the distal femur. One patient with adamantinoma underwent segmental resection and reconstruction with VFFG We recommend that primary fixation of pathological fractures should be avoided until histological diagnosis is obtained. However, if radiographic appearances are reassuringly benign, biopsy can be delayed until conservative fracture management is completed. Definitive treatment of benign lesions with protective intramedullary nailing or curettage and grafting can follow frozen section under the same anaesthetic.