Aims

Orthopaedic and reconstructive surgeons are faced with large defects after the resection of malignant tumours of the sacrum. Spinopelvic reconstruction is advocated for resections above the level of the S1 neural foramina or involving the sacroiliac joint. Fixation may be augmented with either free vascularized fibular flaps (FVFs) or allograft fibular struts (AFSs) in a cathedral style. However, there are no studies comparing these reconstructive techniques.

This paper examines the fate of decalcified allografts (homografts) of iliac cancellous bone impregnated with autologous red marrow and implanted intermuscularly into the anterior abdominal wall of rabbits. In contrast to the findings of Urist and other workers that cortical bone decalcified with hydrochloric acid (HCl) and then freeze-dried is inductive to new bone formation in various heterotopic sites, evidence is presented that iliac bone decalcified by HCl and grafted alone to a muscular site is itself very weakly inductive to bone formation. However, when combined with autologous bone marrow the HCl-decalcified bone provides a better substrate for bone formation by marrow cells than does either undecalcified iliac bone, or iliac bone decalcified with ethylene-diamine-tetra-acetic acid. The freezing or freeze-drying of decalcified bone does not affect new bone formation when implanted alone or with autologous marrow. The differences between the cortical and cancellous bone as inductive substrates for osteogenesis are discussed and the interrelationship of bone and marrow in combined bone grafts are re-evaluated

1. Cancellous bone cubes from calf and man were deproteinised with hydrogen peroxide and with ethylenediamine. 2. Long bones were removed aseptically from sheep, stored in the bone bank and used for cancellous homografts. 3. Holes were drilled in the upper part of the tibia or ulna or in the lower part of the femur of sheep. Some were left empty; others were filled with plugs of the deproteinised heterogenous bone, with autografts, or with homografts. 4. Histological appearances were studied after seventeen and thirty-six days. 5. At seventeen days repair was more advanced in the plugged holes; the biological result was better with the ethylenediamine-treated than with the peroxide-treated material. After thirty-six days repair was at an advanced stage. As much new bone had been deposited on the trabeculae of the deproteinised heterografts as on those of the homografts. 6. There was no evidence of metaplastic bone formation; new bone seemed to form from endosteal osteoblasts. 7. Certain clinical implications are briefly discussed

Aims

There are concerns regarding initial stability and early periprosthetic fractures in cementless hip arthroplasty using short stems. This study aimed to investigate stress on the cortical bone around the stem and micromotions between the stem and cortical bone according to femoral stem length and positioning.

We studied the effects of nine techniques of bone surface preparation on cement penetration and shear strength at the cement-bone interface in a standard model of bovine cancellous bone. In unprepared bone the mean penetration was 0.2 mm and the mean shear strength of the interface was 1.9 MPa, less than that of the underlying bone. Brushing with surface irrigation gave mean penetrations of 0.6 to 1.4 mm and mean shear strengths of 1.5 to 9.9 MPa. In 50% of specimens the interface was weaker than the underlying bone. The use of pressurised lavage resulted in mean penetrations of 4.8 to 7.9 mm and mean shear strengths of 26.5 to 36.1 MPa, which were greater than those of the cancellous bone in all specimens. Pressurised lavage was equally effective alone or in combination with brushing, and its efficacy was not altered by using pulsed or continuous jets, or by changing the temperature of the solution from 21 degrees C to 37 degrees C

Aims

Despite the interest in the association of gut microbiota with bone health, limited population-based studies of gut microbiota and bone mineral density (BMD) have been made. Our aim is to explore the possible association between gut microbiota and BMD.

We developed an in vivo model of the attachment of a patellar tendon to a metal implant to simulate the reconstruction of an extensor mechanism after replacement of the proximal tibia. In 24 ewes, the patellar tendon was attached to a hydroxyapatite (HA)-coated titanium prosthesis. In 12, the interface was augmented with autograft containing cancellous bone and marrow. In the remaining ewes, the interface was not grafted. Kinematic gait analysis showed nearly normal function of the joint by 12 weeks. Force-plate assessment showed a significant increase in functional weight-bearing in the grafted animals (p = 0.043). The tendon-implant interface showed that without graft, encapsulation of fibrous tissue occurred. With autograft, a developing tendon-bone-HA-implant interface was observed at six weeks and by 12 weeks a layered tendon-fibrocartilage-bone interface was seen which was similar to a direct-type enthesis. With stable mechanical fixation, an appropriate bioactive surface and biological augmentation the development of a functional tendon-implant interface can be achieved

We report the results of limb salvage for non-metastatic osteosarcoma of the distal tibia using resection arthrodesis, autogenous fibular graft and fixation by an Ilizarov external fixator. In six patients with primary osteosarcoma of the distal tibia who refused amputation, treatment with wide en bloc resection and tibiotalar arthrodesis was undertaken. The defect was reconstructed using non-vascularised free autogenous fibular strut graft in three patients and a vascularised pedicular fibular graft in three, all supplemented with iliac cancellous graft at the graft-host junction. An Ilizarov external fixator was used for stabilisation of the reconstruction. In five patients sound fusion occurred at a mean of 13.2 months (8 to 20) with no evidence of local recurrence or deep infection at final follow-up. The mean post-operative functional score was 70% (63% to 73%) according to the Musculoskeletal Tumour Society scoring system. All five patients showed graft hypertrophy. Union of the graft was faster in cases reconstructed by vascularised fibular grafts. One patient who had a poor response to pre-operative chemotherapy developed local tumour recurrence at one year post-operatively and required subsequent amputation

Aims

To determine the relationship between articular cartilage status and clinical outcomes after medial opening-wedge high tibial osteotomy (MOHTO) for medial compartmental knee osteoarthritis at intermediate follow-up.

1. An immunological examination of the sera of thirty rabbits which had received primary and secondary homografts of cancellous bone into a subcutaneous site did not reveal the presence of circulating precipitins, haemagglutinins or passive haemagglutinins. These findings are consistent with the observations of Bonfiglio and his colleagues (1955). 2. Electrophoretic examination of the serum of four rabbits receiving primary and secondary homografts of bone into an intramuscular site did not reveal any change in the serum protein fractions. 3. A search for auto-antibodies produced by primary and secondary autografts of cancellous bone was unsuccessful in fifteen rabbits. 4. The multiple injections of saline extracts of bone into four rabbits did not evoke the production of demonstrable circulating antibodies, results which are in accord with the findings of Bonfiglio and colleagues (1955) and Curtiss and colleagues (1959). 5. For the first time the production of classical antibodies in response to injections of extracts of heterologous bone has been recorded. The repeated injections of a saline extract of rabbit bone intraperitoneally into ten mice produced demonstrable precipitins and passive haemagglutinins both to protein and polysaccharide fractions present in the bone extracts. 6. Knowledge concerning the production of humoral antibodies to transplants and extracts of bone has been reviewed

Metal meshes are used in revision surgery of the hip to contain impacted bone grafts in cases with cortical or calcar defects in order to provide rotational stability to the stem. However, the viability of bone allografts under these metal meshes has been uncertain. We describe the histological appearances of biopsies obtained from impacted bone allografts to the calcar contained by a metal mesh in two femoral reconstructions which needed further surgery at 24 and 33 months after the revision procedure. A line of osteoid and viable new bone was observed on the surface of necrotic trabeculae. Active bone marrow between these trabeculae showed necrotic areas in some medullary spaces with reparative fibrous tissue and isolated reactive lymphocytes. This is interpreted as reparative changes after revascularisation of the cancellous allografts. These pathological findings are similar to those reported in allografts contained by cortical host bone and support the hypothesis that incorporation of morcellised bone under metal meshes is not affected by these devices

Between November 1997 and December 2000 we performed 27 total hip replacements in 22 patients with high congenital dislocation of the hip using porous tantalum monoblock acetabular components implanted in the true acetabular bed. Clinical and radiological evaluation was performed at regular intervals for a mean of 10.2 years (8.5 to 12). The mean Harris Hip Score improved from 48.3 (15 to 65) pre-operatively to 89.5 (56 to 100) at the final follow-up. The mean Oxford Hip Score was 49.5 (35 to 59) pre-operatively and decreased to 21.2 (12 to 48) at one year and 15.2 (10 to 28) at final follow-up. Migration of the acetabular component was assessed with the EBRA software system. There was a mean migration of 0.68 mm (0.49 to 0.8) in the first year and a mean 0.89 mm (0.6 to 0.98) in the second year, after excluding one initial excessive migration. No revision was necessary for any reason, no acetabular component became loose, and no radiolucent lines were observed at the final follow-up. The porous tantalum monoblock acetabular component is an implant offering adequate initial stability in conjunction with a modulus of elasticity and porosity close to that of cancellous bone. It favours bone ingrowth, leading to good mid-term results

1. The age of the patient has no influence on the incidence of non-union in fractures of the forearm in adults. 2. The degree of displacement of the fracture is an important factor in non-union, and is related to the violence of the injury. 3. Fractures of one bone unite better than fractures of both bones, and this is due to the stabilising effect of the intact bone. 4. Open and comminuted fractures have a much higher incidence of non-union. 5. The lowest incidence of non-union, allowances being made for other significant factors, was in cases treated conservatively; and after that in cases treated by plating followed by immobilisation in plaster. 6. Plating without subsequent immobilisation in plaster is a method to be abandoned, but there is some advantage in waiting for ten days, until post-operative oedema has been absorbed, before applying the plaster. 7. In cases in which several factors predisposing to non-union are present in the same patient, it seems justifiable to supplement plating by cancellous onlay strips as a primary procedure. 8. In cases of non-union the cancellous insert graft described by Nicoll succeeded in 94·5 per cent of the cases, many of which were exceptionally difficult problems. In 75 per cent union occurred within four months of grafting. 9. The restoration of mobility, either after union of the fracture or after grafting operations, was never a serious problem in the present series

Aims

Aseptic loosening is a leading cause of uncemented arthroplasty failure, often accompanied by fibrotic tissue at the bone-implant interface. A biological target, neutrophil extracellular traps (NETs), was investigated as a crucial connection between the innate immune system’s response to injury, fibrotic tissue development, and proper bone healing. Prevalence of NETs in peri-implant fibrotic tissue from aseptic loosening patients was assessed. A murine model of osseointegration failure was used to test the hypothesis that inhibition (through Pad4^-/- mice that display defects in peptidyl arginine deiminase 4 (PAD4), an essential protein required for NETs) or resolution (via DNase 1 treatment, an enzyme that degrades the cytotoxic DNA matrix) of NETs can prevent osseointegration failure and formation of peri-implant fibrotic tissue.

Aims

During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting.

The use of impacted, morsellised bone grafts has become popular in revision total hip arthroplasty (THA). The initial stability of the reconstruction and the effectiveness of any subsequent process of revitalisation and incorporation will depend on the mechanical integrity of the graft. Our aim in this study was to document the time-dependent mechanical properties of the morsellised graft. This information is useful in clinical application of the graft, in studies of migration of the implant and in the design of the joint. We used 16 specimens of impacted, morsellised cancellous bone from the sternum of goats to assess the mechanical properties by confined compression creep tests. Consideration of the graft material as a porous, permeable solid, filled with fluid, allowed determination of the compressive modulus of the matrix, and its permeability to fluid flow. In all specimens the compression tests showed large, irreversible deformations, caused by flow-independent creep behaviour as a result of rolling and sliding of the bone chips. The mean permeability was 8.82 *10. −12. m. 4. /Ns (SD 43%), and the compressive modulus was 38.7 MPa (SD 34%). No correlation was found between the apparent density and the permeability or between the apparent density and the compressive modulus. The irreversible deformations in the graft could be captured by a creep law, for which the parameters were quantified. We conclude that in clinical use the graft is bound to be subject to permanent deformation after operation. The permeability of the material is relatively high compared with, for example, human cartilage. The confined compression modulus is relatively low compared with cancellous bone of the same apparent density. Designs of prostheses used in revision surgery must accommodate the viscoelastic and permanent deformations in the graft without causing loosening at the interface

Aims

To investigate whether idiopathic osteonecrosis of the femoral head (ONFH) is related to impaired osteoblast activities.

Aims

Minimally manipulated cells, such as autologous bone marrow concentrates (BMC), have been investigated in orthopaedics as both a primary therapeutic and augmentation to existing restoration procedures. However, the efficacy of BMC in combination with tissue engineering is still unclear. In this study, we aimed to determine whether the addition of BMC to an osteochondral scaffold is safe and can improve the repair of large osteochondral defects when compared to the scaffold alone.

Aims

Monocyte-lymphocyte ratio (MLR) or neutrophil-lymphocyte ratio (NLR) are useful for diagnosing periprosthetic joint infection (PJI), but their diagnostic values are unclear for screening fixation-related infection (FRI) in patients for whom conversion total hip arthroplasty (THA) is planned after failed internal fixation for femoral neck fracture.

1. A relatively simple method of spinal fusion with internal splinting by screw fixation has been described. Complications have been few. 2. Emphasis is placed upon thorough removal of soft tissue, correct placement of screws of good length, the exposure of bleeding bone wherever possible in the fusion area, and the use of well packed cancellous bone. 3. There is enough spongy bone in one posterior superior iliac spine for an ordinary spinal fusion, and, if more is needed, the other is readily available through the same skin incision. Not only is cancellous bone more desirable than a massive cortical graft, but the leg is spared, allowing early walking and freedom from complications in the limb. 4. The lateral articulations are left intact. 5. Screw fixation has eliminated the use of external support except in spondylolisthesis, or when so much bone has been removed during laminectomy that good fixation cannot be obtained. 6. Early, sometimes immediate, relief of symptoms is usual after operation, and early walking with moderate activity is desirable. 7. When the operation was done for degenerative changes with no apparent defect in the laminae there was no radiological evidence of failure of fusion after operations at one level, but two failures were found after attempted fusions at multiple levels. 8. Root irritation from screw contact in two patients was due to faulty technique. A method of screw placement to avoid this complication is described and illustrated by radiographs and photographs of a cadaver specimen. 9. There has been no known instance of an adverse psychological effect from the use of screws. Rather, there has commonly been a lively and healthy interest shown in the factor which has allowed early activity