From 1984 to 1995, 68 ankylosed elbows and 11 which were unstable after trauma were replaced in India by Baksi sloppy hinge prostheses. The mean age of the patients was 28.6 years (17 to 70) and the mean follow-up 9.6 years (2 to 13.5). Of the 68 ankylosed elbows, 59 (87%) regained a mean arc of painless movement of 88.5° (27 to 115). The mean improvement of supination was 24° and of pronation 16.5°. There were 54 good results (80%), eight fair and three poor. There were two complete failures due to infection, and one due to a broken humeral stem. Of the 11 unstable elbows, the nine with good results had a mean arc of 125° (15 to 140) of painless stable movement, with a mean improvement in supination of 26° and of pronation of 19.5°. There was one fair result and one failure due to loosening with subsequent late infection. There were significant complications in 14 cases with infection in seven and aseptic loosening in four. Patients with loosening or late removal of the prosthesis often retained reasonably stable elbow movement because periprosthetic fibrosis had connected the approximated bone ends, and muscle balance had been restored

Aims

It has been hypothesized that proximal radial neck resorption (PRNR) following press-fit radial head arthroplasty (RHA) is due to stress-shielding. We compared two different press-fit stems by means of radiographs to investigate whether the shape and size of the stems are correlated with the degree of PRNR.

We have reviewed 66 consecutive Souter-Strathclyde arthroplasties of the elbow implanted in 59 patients between 1982 and 1993. Thirteen patients (15 elbows) (19.6%) died. Sixteen elbows (24.2%) were revised, six for aseptic loosening (9%), four (6%) because of fracture or loosening after a fracture, three (4.5%) for infection and three (4.5%) for dislocation. Four patients refused to attend for review. In 33 elbows with a follow-up of 93 months (60 to 167) complete relief of pain was achieved in 22 (67%) when seen at one year. After ten years or more 36% of the elbows were painfree and 64% had occasional slight pain especially under loading or stress. The mean gain in the arc of movement was 16°, but a mean flexion contracture of 33° remained. The main early complications were intraoperative fractures of the epicondyles (9%), postoperative dislocation (4.5%) and ulnar neuropathy. The incidence of ulnar neuropathy before operation was 19%. After operation 20 patients (33%) had an ulnar neuropathy, in seven of which it had been present before operation, and of these weakness of the hypothenar muscle occurred in two. The probability of survival of the Souter-Strathclyde elbow prosthesis based on the Kaplan-Meier calculation is 69% at ten years

Aims

Total knee arthroplasty (TKA) using functional alignment aims to implant the components with minimal compromise of the soft-tissue envelope by restoring the plane and obliquity of the non-arthritic joint. The objective of this study was to determine the effect of TKA with functional alignment on mediolateral soft-tissue balance as assessed using intraoperative sensor-guided technology.

We followed 138 patients (145 hips) who had had uncemented total hip arthroplasty using the Taperloc femoral component for a mean of ten years (8 to 12.5). No patient was lost to follow-up; 31 (31 hips) died before the minimum time of eight years for inclusion in the study, and 30 of these still had their femoral component in place. One well-fixed prosthesis had been exchanged at the time of acetabular revision. Of the remaining 114 hips, one femoral component required revision for aseptic loosening and one for sepsis. Three other well-fixed femoral components were removed during acetabular revision. Complete clinical and radiological follow-up was obtained in the 109 hips which had not had revision. Clinically, 94 (87%) were rated good or excellent, eight (7%) fair and seven (6%) poor. The average Harris hip score increased from 48 before operation to 88 at the time of the last follow-up. Radiologically, 103 hips (94%) had fixation by bone ingrowth, three (3%) showed stable fibrous ingrowth and three (3%) were unstable. Osteolysis of the femoral cortex was seen in seven hips (6%), with major lysis in only one. At a mean follow-up of ten years, the results of the Taperloc femoral component are comparable with those of modern techniques of cementing in primary total hip arthroplasty

Aims

The purpose of this study was to compare clinical results, long-term survival, and complication rates of stemless shoulder prosthesis with stemmed anatomical shoulder prostheses for treatment of osteoarthritis and to analyze radiological bone changes around the implants during follow-up.

We reviewed retrospectively 50 consecutive total hip arthroplasties with proximal femoral replacement prostheses in 49 patients. All the patients had massive bone loss. There were 31 women and 18 men who had undergone a mean of 3.1 hip operations. At the last review, 15 patients had died and two had been lost to follow-up, so that 32 patients (33 hips) were available for assessment. The mean age of the patients at the time of the operation was 60.6 years. The mean length of clinical follow-up was 11.1 +/- 4 years, and mean radiographic follow-up was 7.6 +/- 3.2 years. The average preoperative Harris hip score was 46 +/- 13 points, which improved to 80 +/- 10 points after one year and to 76 +/- 16 points at the latest follow-up. The most frequent complication was dislocation, which occurred in 11 hips. Four femoral components and seven acetabular prostheses were revised because of aseptic loosening. With revision at the end point, survivorship after total hip arthroplasty with a proximal femoral replacement prosthesis was predicted to be 64% at 12 years. Although our preliminary results of hip salvage with a proximal femoral replacement prosthesis were encouraging, a longer follow-up has shown a higher rate of failure

We studied 108 patients (116 hips) who were followed for a minimum of six years (73 to 89 months) after primary total hip arthroplasty using an uncemented porous-coated anatomic hip. The average age of the patients at operation was 48.4 years, and the diagnosis was avascular necrosis of the femoral head in 46 hips, neglected femoral neck fracture in 27, osteoarthritis secondary to childhood pyogenic arthritis in 24 and to childhood tuberculous arthritis in five, and miscellaneous in 14. The average preoperative Harris hip score was 55, which improved to 91 at latest follow-up. All patients with loose femoral components or disabling thigh pain had received prostheses which were undersized in the coronal or the sagittal plane, or in both. No patient with a satisfactory fit in both coronal and sagittal planes had loosening of the femoral component or disabling thigh pain. Three acetabular components showed aseptic loosening and 20 showed excessive wear (5 to 11 mm) of the polyethylene liner. Excessive wear was related to young age, but not to body-weight, gender, primary diagnosis, hip score, or range of hip movement. There was a high incidence of osteolysis (38 of 116 hips, 33%). We recommend careful preoperative planning, with the use of a contemporary cemented technique when a satisfactory fit cannot be obtained. The high incidence of excessive wear and of osteolysis needs further investigation

Mononuclear osteoclast precursors are present in the wear-particle-associated macrophage infiltrate found in the membrane surrounding loose implants. These cells are capable of differentiating into osteoclastic bone-resorbing cells when co-cultured with the rat osteoblast-like cell line, UMR 106, in the presence of 1,25(OH). 2. vitamin D. 3. In order to develop an in vitro model of osteoclast differentiation which more closely parallels the cellular microenvironment at the bone-implant interface in situ, we determined whether osteoblast-like human bone-derived cells were capable of supporting the differentiation of osteoclasts from arthroplasty-derived cells and analysed the humoral conditions required for this to occur. Long-term co-culture of arthroplasty-derived cells and human trabecular-bone-derived cells (HBDCs) resulted in the formation of numerous tartrate-resistant-acid-phosphatase (TRAP) and vitronectin-receptor (VNR)-positive multinucleated cells capable of extensive resorption of lacunar bone. The addition of 1,25(OH). 2. vitamin D. 3. was not required for the formation of osteoclasts and bone resorption. During the formation there was release of substantial levels of M-CSF and PGE. 2. Exogenous PGE. 2. (10. −8. to 10. −6. M) was found to stimulate strongly the resorption of osteoclastic bone. Our study has shown that HBDCs are capable of supporting the formation of osteoclasts from mononuclear phagocyte precursors present in the periprosthetic tissues surrounding a loose implant. The release of M-CSF and PGE. 2. by activated cells at the bone-implant interface may be important for the formation of osteoclasts at sites of pathological bone resorption associated with aseptic loosening

Aims

Hip resurfacing arthroplasty (HRA) is typically indicated for young and active patients. Due to the longevity of arthroplasty, these patients are likely to undergo revision surgery during their lifetime. There is a paucity of information on the long-term outcome of revision surgeries performed after failed HRA. The aim of our study was to provide survivorship data as well as clinical scores after HRA revisions.

Between 1978 and 1986, 59 patients received a GSB III elbow prosthesis, six of them in both elbows. Rheumatoid arthritis (RA) was the underlying cause in 51 of the patients and post-traumatic osteoarthritis (PTOA) in eight. Of these, 24 patients (28 prostheses) have since died; two, both operated on bilaterally, had had their implants for more than ten years and had already been assessed for inclusion in the long-term follow-up. Two patients, each with one elbow prosthesis, have been lost to follow-up and three males who are still living (two with PTOA, one with juvenile RA) had their prosthesis removed before ten years had elapsed. The remaining 32 patients (28 RA, 4 PTOA) with 36 GSB III elbows were examined clinically and radiologically after a mean period of 13.5 years. Pain was considerably reduced in 91.6%. Mobility was increased by 37° in those with RA and by 67° in those with PTOA. There were three cases of aseptic loosening and three of deep infection. The main complication was disassembly of the prosthetic component in nine elbows (13.8%). This last group included two patients with postoperative fractures unrelated to the operative technique and one with neuropathic arthritis. Ulnar neuritis occurred in two patients. Since 87.7% of all the GSB III prostheses implanted in this period remained in situ, our results are comparable with those for hip and knee arthroplasty

A consecutive series of 235 total knee arthroplasties using the PFC system was followed prospectively for at least ten years in 186 patients. The operation was for osteoarthritis in 150 knees, for rheumatoid arthritis in 83, and for Paget’s disease and femoral osteonecrosis in one knee each. At the latest review 56 patients had died, fi ve were too ill to assess and three could not be traced. The PFC knee replacement utilised was a nonconforming posterior-cruciate-retaining prosthesis with a polyethylene insert which is fl at in the sagittal plane. The patella was resurfaced using a metal-backed component in 170 cases, but later in the series we used an all-polyethylene component in 22 knees; 43 patellae were not resurfaced. The survival without need for reoperation for any reason was 90% at ten years. Nineteen revisions were component-related due to failure of nine metal-backed patellae, nine polyethylene inserts, and one unresurfaced patella; two reoperations were for synovectomy (one for recurrent haemarthrosis and one for recurrent rheumatoid synovitis) and three were for metastatic joint infection. There were no revisions for aseptic loosening of femoral or tibial components, or the all-polyethylene patellar replacement. The PFC system provides good and predictable results in tricompartmental arthritis of the knee. Loosening appeared to be negligible, but there were wear-related problems in 8%. The change from a metal-backed patella and an increase in the contact area of the tibial insert should provide further improvement by minimising wear

A heavy infiltrate of foreign-body macrophages is commonly seen in the fibrous membrane which surrounds an aseptically loose cemented implant. This is in response to particles of polymethylmethacrylate (PMMA) bone cement and other biomaterials. We have previously shown that monocytes and macrophages responding to particles of bone cement are capable of differentiating into osteoclastic cells which resorb bone. To determine whether the radio-opaque additives barium sulphate (BaSO. 4. ) and zirconium dioxide (ZrO. 2. ) influence this process, particles of PMMA with and without these agents were added to mouse monocytes and cocultured with osteoblast-like cells on bone slices. Osteoclast differentiation, as shown by the presence of the osteoclast-associated enzyme tartrate-resistant acid phosphatase (TRAP) and lacunar bone resorption, was observed in all cocultures. The addition of PMMA alone to these cocultures caused no increase in TRAP expression or bone resorption relative to control cocultures. Adding PMMA particles containing BaSO. 4. or ZrO. 2. , however, caused an increase in TRAP expression and a highly significant increase in bone resorption. Particles containing BaSO. 4. were associated with 50% more bone resorption than those containing ZrO. 2. . Our results suggest that radio-opaque agents in bone cement may contribute to the bone resorption of aseptic loosening by enhancing macrophage-osteoclast differentiation, and that PMMA containing is BaSO. 4. likely to be associated with more osteolysis than that containing ZrO. 2.

After an allogenic bone-marrow transplant, a vascular necrosis of the femoral head may affect young adults, producing destructive lesions which require hip replacement. We have reviewed 27 consecutive such total hip arthroplasties (THA) at a minimal follow-up of two years. Of these, 20 were primary operations for Ficat (1985) stage-III and stage-IV lesions, and seven were revisions after the failure of previous surgery. The median age at operation was 30 years (17.5 to 44). The prostheses had a cemented, collared titanium-alloy stem, an alumina-alumina joint, and a press-fit socket. Seven had a titanium-alloy metal back and 20 had all-alumina cups of which six had to be cemented. At an average follow-up of five years, no patient had been lost to follow-up. One had died from septicaemia after two years and another with chronic graft-versus-host disease developed a deep infection 2.5 years postoperatively and had a successful revision. There were no revisions for aseptic loosening. The clinical results on the Merle d’Aubigné and Postel (1954) scale were very good or excellent in 23 hips (88%), good in one and fair in two. Ten hips showed incomplete acetabular radiolucencies less than 1 mm thick, but there were no radiolucent lines around the stems. We conclude that for these difficult patients THA with ceramic joints and careful technique provides the best short- and medium-term option after the failure of medical treatment

Aims

Vitamin E-infused highly crosslinked polyethylene (VEPE) has been introduced into total hip arthroplasty (THA) with the aim of further improving the wear characteristics of moderately and highly crosslinked polyethylenes (ModXLPE and HXLPE). There are few studies analyzing the outcomes of vitamin E-infused components in cemented arthroplasty, though early acetabular component migration has been reported. The aim of this study was to measure five-year polyethylene wear and acetabular component stability of a cemented VEPE acetabular component compared with a ModXLPE cemented acetabular component.

We compared the peripheral blood and periprosthetic tissues of 53 patients at revision arthroplasty with those of 30 patients at primary arthroplasty to determine whether there is a systemic difference in lymphocytes in patients with worn hip implants. The absolute number and relative proportion of lymphocytes bearing CD2, CD3, CD4, CD8, CD16, CD19, HLA-DR, kappa and lambda antigens were compared with the levels of IL-1β, IL-6 and PGE. 2. in the pseudosynovial membrane as well as with a semiquantitative estimate of metal and polyethylene particles, necrosis and chronic inflammation and the total concentration of metals within the periprosthetic tissues. There was a significant increase in the relative proportion of CD2-positive T-cells and CD16-positive natural killer cells in the peripheral blood at revision arthroplasty compared with primary arthroplasty and an increased proportion of CD8-positive T-cells and a decreased ratio of CD4 to CD8 (helper inducer/suppressor cytotoxic cells). Three control patients, who went on to have revision surgery, had values at primary arthroplasty which were similar to those of patients at the time of revision surgery. These differences did not correlate with the local concentration of metal, plastic or cement or inflammatory response or the type of prosthesis. An inverse correlation was noted between the necrosis in the periprosthetic tissue and both the local production of IL-6 and the absolute numbers of T-cells in peripheral blood. We conclude that there may be several cell-mediated systemic immune responses to aseptic loosening, at least one of which may be directly related to events in the periprosthetic tissues. We cannot exclude the possibility that the changes in the proportion of CD8-positive cells reflected a predisposition, rather than a reaction, to loosening of the implant

Periprosthetic osteolysis is a major cause of aseptic loosening in artificial joint replacement. It is assumed to occur in conjunction with the activation of macrophages. We have shown in vitro that human osteoblast-like cells, isolated from bone specimens obtained from patients undergoing hip replacement, phagocytose fine particles of titanium alloy (TiAlV). The human osteoblast-like cells were identified immunocytochemically by the presence of bone-specific alkaline phosphatase (BAP). With increasing duration of culture, a variable number of the osteoblastic cells became positive for the macrophage marker CD68, independent of the phagocytosis of particles, with a fine granular cytoplasmic staining which was coexpressed with BAP as revealed by immunodoublestaining. The metal particles were not toxic to the osteoblastic cells since even in culture for up to four weeks massively laden cells were vital and had a characteristic morphology. Cells of the human osteosarcoma cell line (HOS 58) were also able to phagocytose metal particles but had only a low expression of the CD68 antigen. Fluorescence-activated cell scanning confirmed our immunocytochemical results. Additionally, the cells were found to be negative for the major histocompatibility complex-II (MHC-II) which is a marker for macrophages and other antigen-presenting cells. Negative results of histochemical tests for tartrate-resistant acid phosphatase excluded the contamination by osteoclasts or macrophages in culture. Our observations suggest that the osteoblast can either change to a phagocytosing cell or that the phagocytosis is an underestimated property of the osteoblast. The detection of the CD68 antigen is insufficient to prove the monocytic lineage. In order to discriminate between macrophages and osteoblasts additional markers should be used. To our knowledge, this is the first demonstration of cells of an osteoblastic origin which have acquired a mixed phenotype of both osteoblasts and macrophages

Aims

We aimed to examine the long-term mechanical survivorship, describe the modes of all-cause failure, and identify risk factors for mechanical failure of all-polyethylene tibial components in endoprosthetic reconstruction.