Early metallosis-related failure after total knee replacement: a report of 15 cases.

Metallosis is a rare cause of failure after total knee replacement and has only previously been reported when there has been abnormal metal-on-metal contact. We describe 14 patients (15 knees) whose total knee replacement required revision for a new type of early failure caused by extensive metallosis. A modification of a cementless rotating platform implant, which had previously had excellent long-term survival, had been used in each case. The change was in the form of a new porous-beaded surface on the femoral component to induce cementless fixation, which had been used successfully in the fixation of acetabular and tibial components. This modification appeared to have resulted in metallosis due to abrasive two-body wear. The component has subsequently been recalled and is no longer in use. The presentation, investigation, and findings at revision are described and a possible aetiology and its implications are discussed.

Early results of total knee arthroplasty with a low contact stress anteroposterior glide.

PURPOSE: To present early results of 400 consecutive low contact stress (LCS) anteroposterior (AP) glide total knee arthroplasties (TKAs) performed by a single surgeon. METHODS: 304 consecutive patients aged 30 to 96 (mean, 66) years underwent 400 TKAs using LCS AP glides performed by a single surgeon. Only patients with an intact posterior cruciate ligament, a fixed flexion deformity of <15 degrees, and a valgus deformity of <15 degrees were included. Patients were assessed pre- and post-operatively using the American Knee Society (AKS) and Hospital for Special Surgery (HSS) scores. Range of motion was measured using a goniometer. AP and lateral radiographs were assessed for radiolucencies and osteolysis. RESULTS: The mean follow-up period was 4.2 (range, 1-8) years. The mean fixed flexion improved to 1 from 11 degrees and the mean active flexion improved to 120 from 111 degrees. Both AKS and HSS scores improved significantly. There were 28 anterior soft tissue impingements; 9 of them were in the first year of the study. Thereafter, the anterior lip of the bearing was modified and any offending osteophytes, soft tissue, or fat pads were excised. Of 39 (10%) knees that underwent re-operation (16 were due to anterior soft tissue impingement), 20 (5%) did not require change of the AP glide bearing and the remaining 19 were converted to a rotating platform bearing. No patellar baja was noted after fat pad excision. No patient had catastrophic wear or failure of the polyethylene bearing. The survival rate of the AP glide bearing was 95%. CONCLUSION: The early-to-mid-term outcomes of the LCS AP glide TKA are promising.

Twenty-year survival of a cementless revision hip arthroplasty using a press-fit bulk acetabular allograft for pelvic discontinuity: a case report.

Acetabular revision in a total hip arthroplasty (THA) with pelvic discontinuity is uncommon and challenging. Optimal management remains controversial, particularly with graft and implant selection. Interpretation of outcomes is confounded by the heterogeneity of patterns of bone loss and the lack of long-term results in great numbers for any given choice of treatment. We report a revision THA using a press-fit bulk acetabular allograft and an uncemented porous-coated anatomic prosthesis for the management of pelvic discontinuity. After 20 years, the patient still had an excellent functional outcome with radiographic evidence of graft incorporation and no signs of loosening.

A retrospective comparative study of bilateral total knee replacement staged at a one-week interval.

The clinical results of bilateral total knee replacement staged at a one-week interval during a single hospital admission were compared with bilateral total knee replacements performed under the same anaesthetic and with bilateral total knee replacements performed during two separate admissions. The data were retrospectively reviewed. All operations had been performed by the same surgeon using the same design of prosthesis at a single institution. The operative time and length of stay for the one-week staged group were comparable with those of the separate admission group but longer than for the patients treated under one anaesthetic. There was a low rate of complications and good clinical outcome in all groups at a mean follow-up of four years (1 to 7.2). The group staged at a one-week interval had the least blood loss (p = 0.004). With appropriate patient selection, bilateral total knee replacement performed under a single anaesthetic, or staged at a one-week interval, is a safe and effective method to treat bilateral arthritis of the knee.

Development rationale for an articular surface replacement: a science-based evolution.

Hip resurfacing has an enduring appeal because of the advantages of bone conservation and maximal joint stability. However, a far from satisfactory experience with earlier resurfacing designs led to its virtual disappearance in the 1980s. The concept was reintroduced in the late 1990s. The current generation of resurfacing devices generally consisted of a large-diameter metal-on-metal articulation, the femoral components being cemented and the acetabular components utilizing various forms of cementless fixation. The encouraging medium-term results, with a follow-up of up to 8 years using the current generation of surface replacement joints, combined with favourable reports related to long-term performance of some metal bearings have led to a rapid increase in the use of such components with these devices. This trend is most marked in younger, more active patients who have expectations of restoration of lifestyle in addition to improved mobility and pain relief and in whom failure with conventional total hip replacement is much higher than previously reported with more sedentary patients. The aim of this paper is, firstly, to highlight a number of areas of improvement and, secondly, to explain how these may be addressed by making modifications to the design of both implants and instrumentation and to the surgical technique. The areas identified for improvement were tissue preservation (thinner components, and reduced steps between sizes), acetabular cup issues (fixation, insertion, and positioning), femoral component issues (design, loading, and cementation), improved bearing surface characteristics, and simplified precise instrumentation with a low-trauma surgical technique.

Hip joint range of motion reduction in sports-related chronic groin injury diagnosed as pubic bone stress injury.

Traumatic osteitis pubis is a non-specific entity that relates to chronic groin injury and has recently been described as being akin to a pubic bone stress injury. It is uncertain whether or not reduction of hip joint range of motion occurs in traumatic osteitis pubis. The purpose of this study was to establish whether there is a reduction of hip range of motion in athletes who have chronic groin injury diagnosed as pubic bone stress injury. A case-control study was performed whereby 89 Australian Rules footballers underwent, with clinical history unknown, clinical and MRI examination of the groin region. Clinical criteria (pain with tenderness) and MR-criteria (pubic bone marrow oedema) were used for diagnosis of pubic bone stress injury. End-range internal and external rotation hip motion was measured using a goniometer. Athletes with and without symptoms were compared, as were athletes with current symptoms with athletes who had recovered from their groin pain episode. Chronic groin injury was diagnosed in 47 athletes with 37 having pubic bone stress injury. Thirteen athletes had previous groin injury. A reduction of internal and external hip range of motion was demonstrated in athletes with pubic bone stress injury (p < 0.05) and in athletes who had current symptoms compared to those who had recovered from their groin pain episode (p < 0.05). A reduction in hip range of motion was evident in athletes with chronic groin injury diagnosed as pubic bone stress injury. There may be a role for increasing hip range of motion in rehabilitation.

Human immunodeficiency virus infection of human bone derived cells.

Human immunodeficiency virus infection of a human bone derived cell line was initiated by either cell free virus or with a cell to cell transmission method. The human bone derived cells were examined for 8 weeks, and virus infection was not detected when assessed by microscopy, immunofluorescence, reverse transcriptase activity, or infection of cocultivated human T lymphoid cells susceptible to human immunodeficiency virus. Polymerase chain reaction analysis of human bone derived cells inoculated with the cell to cell infection format showed less than 0.1% infected cells. It is possible that the infected cells detected by polymerase chain reaction were lymphocytes used in the cell to cell infection format. Alternatively, latent infection may have been established in the bone derived cells with no apparent expression of the proviral genome. A large proportion of bone is represented by human bone derived cells, and it is unlikely that bone will contribute to a significant human immunodeficiency virus reservoir in vivo. The blood of bone allograft donors is likely to have a greater virus bioburden than is bone. Methods to sterilize bone should be assessed by their efficacy to inactivate the virus in blood contaminating the graft, and methods to detect human immunodeficiency virus deoxyribonucleic acid in a bone graft may be less sensitive than examining the donor's blood.

Radiographic changes in the knee after meniscal transplantation. An experimental study in a sheep model.

Meniscal transplantation has been suggested as an alternative to total meniscectomy, which is now known to lead to long-term osteoarthritic degeneration of the knee joint. To evaluate the success of meniscal transplantation, we divided 28 sheep knees into 4 groups: total meniscectomy, allograft, autograft, and control. After a mean postoperative time of 21.4 months, we radiographed the excised knee joints in a loaded state and graded the radiographs for osteoarthritic changes. The knees with meniscectomies, allografts, and autografts showed significantly more degenerative changes than the control knees. However, there were no statistically significant differences between these three groups. The results of this study suggest that meniscal allograft transplantation does not protect the knee against degenerative changes.

HIV infection of human cartilage.

Infection of human cartilage with HIV in vivo has not previously been reported. Specimens of articular cartilage taken at postmortem from ten patients who were HIV-positive were examined. Two had AIDS and eight were believed to have stage-2 disease. The standard polymerase chain reaction (PCR) protocol was modified to allow semiquantitative analysis of the samples. Oligonucleotide primers labelled with 32P gamma-ATP were used to detect a segment of HIV DNA and a control DNA gene segment (HLA genome) to estimate the ratio of infected cells. The 32P-labelled PCR products were separated on acrylamide gels and visualised directly by autoradiography and computer densitometry. Infection of human cartilage in vivo was demonstrated in nine of the ten samples in which the PCR analysis was positive. The other did not react sufficiently to produce detectable radiolabelled PCR product despite repeated DNA digestion and extraction. Cartilage infected with HIV could be a potential source of HIV when used in operations.

Bone allograft banking in South Australia.

The South Australian Bone Bank had expanded to meet an increased demand for allograft bone. During a 5 year period from 1988 to 1992, 2361 allografts were harvested from 2146 living donors and 30 cadaveric donors. The allografts were screened by contemporary banking techniques which include a social history, donor serum tests for HIV-1, HIV-2, hepatitis B and C, syphilis serology, graft microbiology and histology. Grafts were irradiated with 25 kGy. The majority of grafts were used for arthroplasty or spinal surgery and 99 were used for tumour reconstruction. Of the donated grafts 336 were rejected by the bank. One donor was HIV-positive and two had false positive screens. There were seven donors with positive serology for hepatitis B, eight for hepatitis C and nine for syphilis. Twenty-seven grafts had positive cultures. Bone transplantation is the most frequent non-haematogenous allograft in South Australia and probably nationally. The low incidence of infectious viral disease in the donor population combined with an aggressive discard policy has ensured relative safety of the grafts. The frequency of graft rejection was similar to other bone banks but the incidence of HIV was lower.

Sterilization of HIV by gamma irradiation. A bone allograft model.

A human immuno-deficiency virus (HIV) infected bone allograft model has been created using HTLV-IIIB virus in a concentration simulating a massively HIV infected bone allograft donor [HTLV-III is the denomination initially given to the human immuno-deficiency by the american team of Prof. Gallo. It represent the virus HIV 1 of the present international nomenclature]. 5 x 10(4) tissue culture infective doses per ml. of virus were placed within the medullary cavity of bovine femora and tibiae with a radiation dosimeter, and the ends sealed with lead. The bone/virus model was maintained at -70 degrees C while being irradiated with 1 to 4 megarads of gamma irradiation in increments of 0.5 megarads. The study showed that the HTLV-IIIB virus is a relatively radio-resistant organism, a property common to most viruses. The results suggest that HTLV-IIIB can be inactivated in bone infected with a clinically significant viral load, as may be found in donors who are initially negative when screened for HIV. It is recommended that bone allografts which are secondarily sterilized by gamma irradiation receive at least 2.5 megarads. The amount of radiation absorbed by the bone cortex was minimal.

Allograft bone in the treatment of desmoplastic fibroma. A case report.

A 17-year-old girl had a desmoplastic fibroma of the distal femur. This rare tumor is managed by surgery alone and requires a marginal to wide resection because of its high risk of local recurrence. Had the tumor invaded into the epiphysis and marginal resection, it would have resulted in loss of articular femoral condyle. It was treated by en bloc proximal resection with distal intralesional curettage and anatomic specific allograft femoral replacement. There was no recurrence of the tumor three years after surgery, and function was excellent.

Revision arthroplasty of the proximal femur using allograft bone.

Revision arthroplasty of the hip may require restoration of bone stock on the femoral side to provide bone support for the new implant and restore anatomy and leg length. Large cortical defects can be reconstructed best with allograft bone because of the quality and quantity of the bone required. In this article, the surgical technique and results of cortical allograft as full circumferential and cortical strut grafts are presented.

A review of imaging practice in bone and soft tissue lesions.

Thirty six consecutive bone and soft tissue lesions which were referred to the Bone Transplantation Service between January 1987 and June 1989 were reviewed with respect to the information provided by pre-operative CT, MR and plain X-ray and the final histopathologic diagnosis. The ability of CT and MR to demonstrate cortical destruction, periosteal reaction, a soft tissue mass and soft tissue calcification was scored on a scale of one (low suspicion of abnormality) to four (definite abnormality) in each case. Of the thirty six cases reviewed there were twenty-two histologically confirmed tumours with all of the above three imaging modalities available for comparison. In each of these tumours MR was found to provide an equal or more accurate assessment of soft tissue extent. On a scale of 1 to 4 the average point scores were 3.6 and 2.6 for MR and CT respectively. Little difference was shown between CT and MR with respect to medullary involvement (4.0 points vs. 3.9) and cortical destruction (2.5 points vs. 2.7). CT (3.7 points) was more sensitive than MR (1.2 points) in detecting fine soft tissue calcification. In only five cases did the radiology report correctly nominate the histologic diagnosis and thus the role of imaging was more valuable in staging than diagnosis. For this reason a management oriented report should include comment regarding cortical destruction, the intramedullary extent of tumour and the extent of soft tissue involvement. MR is recommended in the investigation of all suspected malignant soft tissue or bone tumours.

Proximal femoral allografts in revision hip arthroplasty.

We followed prospectively 69 patients with 78 proximal femoral allografts performed for revision of total hip arthroplasty for an average of 36 months (range 29 to 68). Large fragment proximal femoral allografts and cortical strut allografts were successful in 85%. Grafts smaller than 3 cm in length (calcar grafts) were clinically successful in 81%, but 50% underwent significant radiographic resorption. We conclude that large proximal femoral allografts and cortical strut allografts provide dependable reconstruction of bone stock deficiencies during revision total hip arthroplasty.

Recurrent osteoid osteoma. Case report with a ten-year asymptomatic interval.

Osteoid osteoma has been accepted as a distinct clinical and pathologic entity for more than 50 years. Surgical curettage will often cure the lesion, although en bloc excision is now the preferred treatment. The development of local recurrence after surgery, although rare, has been well documented after both curettage and en bloc excision. Symptomatic recurrence of an osteoid osteoma was seen ten years after surgical curettage. Its occurrence at the same site as the original lesion is consistent with the concept that it had originated from residual tissue and is in keeping with the concept of osteoid osteoma as a benign tumor.

A clinical and histologic analysis of failed fresh osteochondral allografts.

Fresh small osteochondral allografts were implanted in 108 patients. A clinical and histologic analysis was undertaken in 18 patients whose grafts failed and were excised. Twelve of these patients had evidence of viable hyaline cartilage despite adverse conditions. If careful attention is given to patient selection, age, appropriate timing for correction of alignment, and meticulous technique associated with graft positioning, size, and thickness, then the incidence of clinical failure should be minimized.

A rat model of resorption of bone at the cement-bone interface in the presence of polyethylene wear particles.

Resorption of bone and the formation of a membrane at the interface between acrylic cement and bone were induced by particles of high-density polyethylene that were similar in size to those that are present in the tissues surrounding a human joint prosthesis. A non-weight-bearing plug of methylmethacrylate was inserted through the knee joint into the distal part of the femur of the rat. The plug rapidly became surrounded by a shell of bone. After repeated injections of particles of high-density polyethylene into the knee joint, resorption of bone occurred at this stable interface. No resorption of bone occurred after the opposite knee was injected with a control preparation that did not contain particles. The resorption of bone that occurred around the plug after the injection of particles of polyethylene took place in the absence of mechanical causes for loosening and in the absence of infection.

Revision total hip arthroplasty with osseous allograft reconstruction. A clinical and roentgenographic analysis.

One hundred twelve irradiation-sterilized, -70 degrees frozen allografts have been used in 72 patients who were available for follow-up study in a prospective analysis of allograft revision total hip arthroplasty. Clinical objectives were achieved in 85% of patients with a follow-up period ranging from six to 72 months. Based on clinical and roentgenographic analysis, specific recommendations are made to further improve the success rate of revision total hip arthroplasty associated with protrusio, shelf, acetabular, calcar, and large fragment femoral allografts.