Excellent Survival and Good Outcomes at 15 Years Using the Press-Fit Condylar Sigma Total Knee Arthroplasty.

BACKGROUND: We report 15-year survival, clinical, and radiographic follow-up data for the Press-Fit Condylar Sigma total knee arthroplasty. METHODS: Between October 1998 and October 1999, 235 consecutive TKAs were performed in 203 patients. Patients were reviewed at a specialist nurse-led clinic before surgery and at 5, 8-10, and 15 years postoperatively. Clinical outcomes, including Knee Society Score, were recorded prospectively at each clinic visit, and radiographs were obtained. RESULTS: Of our initial cohort, 99 patients (118 knees) were alive at 15 years, and 31 patients (34 knees) were lost to follow-up. Thirteen knees (5.5%) were revised; 5 (2.1%) for infection, 7 (3%) for instability, and 1 (0.4%) for aseptic loosening. Cumulative survival with the end point of revision for any reason was 92.3% at 15 years and with revision for aseptic failure as the end point was 94.4%. The mean Knee Society Score knee score was 77.4 (33-99) at 15 years, compared with 31.7 (2-62) preoperatively. Of 71 surviving knees for which X-rays were available, 12 (16.9%) had radiolucent lines and 1 (1.4%) demonstrated clear radiographic evidence of loosening. CONCLUSION: The Press-Fit Condylar Sigma total knee arthroplasty represents a durable, effective option for patients undergoing knee arthroplasty, with excellent survival and good clinical and radiographic outcomes at 15 years.

Thromboembolic disease after total knee replacement: experience of 5100 cases.

The aim of the study was to quantify the incidence and timing of venous thromboembolic events (VTE) after total knee replacement (TKR). Data from 5100 consecutive TKRs performed over 10 years were prospectively collected. Cases were reviewed to identify thromboprophylaxis given, the diagnosis of VTE, treatment and adverse outcomes. There were 3 deaths (0.059%) from pulmonary embolism (PE). Of 123 VTEs identified, 55 had PE, 17 had above knee deep vein thrombosis (DVT), 28 had calf DVT and 14 had been incorrectly coded as VTE. There was considerable inappropriate treatment of calf DVT with resultant morbidity. There was an increase in diagnosis of PE between days 1 and 5 post surgery in the later part of the study, corresponding with increasing use of CT Pulmonary Angiography. Increasing diagnosis of PE may be due to detection of embolic debris from surgery due to greater vigilance rather than post-operative thromboembolism. Death from PE is rare following TKR.

Five-year results of the Sigma total knee arthroplasty.

The DePuy Sigma total knee arthroplasty (TKA) was introduced in 1997 as a modification of the Press Fit Condylar Knee (PFC) TKA and has been used extensively in the United Kingdom and worldwide. It is the most commonly used TKA in England and Wales, where it accounts for 36% of all primary TKA. The PFC was well established, with reported 10-year survival rates of 93-97%, but this study reports the first 5-year clinical and radiographic follow-up data for the Sigma TKA. Over a 10-month period, 212 Sigma TKAs were performed in 180 patients. Patients were seen at a specialist nurse-led clinic 7 to 10 days before admission and at 6 months, 18 months, 3 years and 5 years after surgery. Data were recorded prospectively at each visit. Radiographs were obtained at the 5-year follow-up appointment. Of 212 knees, 178 (151 patients) were alive at 5 years. Three were lost to follow up. Six knees (3.0%) were revised, five for infection and one underwent change of polyethylene insert at 4.9 years. Five-year survival with an endpoint of revision for any reason was 97.0%; with an endpoint of revision for aseptic failure it was 99.5%. The median American Knee Society knee rating score was 93 out of 100 at 5 years compared with 25 out of 100 at admission. Of 147 radiographs, none showed radiographic loosening of either component. Seventeen (11.6%) showed radiolucent lines. Twenty-eight (19.0%) had alignment outside the range of 7+/-3 degrees valgus. These results suggest that the Sigma TKA gives acceptable clinical results after 5 years. Further follow-up studies are required to see if this performance is maintained in the long term.

Association between decreased bone mineral density and severity of distal radial fractures.

BACKGROUND: The role of osteoporosis and osteopenia in the etiology of fractures of the distal part of the radius is well established, but any link between osteoporosis and the severity of the distal radial fracture has not been extensively investigated. The aim of this study was to investigate the association between the degree of osteoporosis and the severity of distal radial fractures. METHODS: All patients over fifty-five years of age with a low-energy distal radial fracture were offered dual x-ray absorptiometry scanning of the hip. Data on the 137 consecutive patients were collected prospectively. Plain radiographs of the fractured distal part of the radius were assessed for angulation, metaphyseal and articular comminution, carpal malalignment, ulnar variance, AO/OTA group and subgroup classification, early and late displacement, and malunion. Fracture severity was quantified with use of previously published algorithms for calculating the probability of early and late displacement, late carpal malalignment, and malunion. These severity scores were correlated with the dual x-ray absorptiometry T-scores, which represent the number of standard deviations by which the measured bone density differs from the mean value in healthy controls. RESULTS: There was a significant linear correlation between increasingly negative T-scores and increasing likelihood of early instability, late carpal malalignment, and malunion. Patients with osteoporosis (a T-score of less than -2.5) had a 43% probability of having early instability, a 39% probability of having late carpal malalignment, and a 66% probability of having malunion. Patients with osteopenia (a T-score of more than -2.5 but less than -1) had a 35% probability of having early instability, a 31% probability of having late carpal malalignment, and a 56% probability of having malunion. This compared with a 28% probability of early instability, a 25% probability of late carpal malalignment, and a 48% probability of malunion in patients with normal bone mineral density (a T-score of more than -1). CONCLUSIONS: There is a definite correlation between bone mineral density and the severity of distal radial fractures.

The epidemiology of musculoskeletal tendinous and ligamentous injuries.

This study describes the epidemiology of a range of adult musculoskeletal soft tissue injuries. Our institution is the only hospital treating adults with musculoskeletal trauma in a well-defined catchment population of about 535,000. Demographic details over 5 years were recorded prospectively. Eighteen injury types were studied including anterior cruciate ligament (ACL) rupture, acromioclavicular joint (ACJ) injury, Achilles, patellar and quadriceps tendon ruptures, hand tendon injuries and mallet finger. 2794 patients presented with ligamentous or tedinous injuries over 5 years. 74.2% of patients were male, giving an incidence of 166.6/100,000 per year for males and 52.1/100,000 per year for females. The mean age was 36.3 years: 33.1 in males, 43.6 in females. 1040 (37.2%) were knee injuries: 75.6% were male with mean age 32.9, compared with 35.3 in females. 947 cases were hand tendon injuries (33.9%): 72.1% were male, with mean age 34.5 compared with 42.0 in females. Meniscal injury of the knee was the commonest injury with an incidence of 23.8/100,000 per year. Other common injuries were hand extensor tendons (18/100,000 per year), ACJ injury (14.5/100,000 per year), Achilles tendon rupture (11.3/100,000 per year), mallet finger (9.9/100,000 per year) and ACL rupture (8.1/100,000 per year). Achilles, patellar and quadriceps tendon rupture and mallet finger were injuries of middle age; rotator cuff tears and biceps tendon rupture were commoner in the elderly but all other injuries predominated in young patients. All injuries were commoner in males. Most soft tissue injuries follow distribution curves previously described for fracture epidemiology but three new distribution curves are presented for the injuries which predominate in middle age.

Kinetic and phenotypic changes in murine lymphocytes infected with murine gammaherpesvirus-68 in vitro.

Primary infection with murine gammaherpesvirus-68 (MHV-68), as with other members of the gammaherpesvirus subfamily, is characterized by a lymphoproliferative phase. MHV-68 causes acute splenomegaly and an infectious mononucleosis-like syndrome in which there is expansion of the CD8+ T cell subset. In long-term infections, MHV-68 is associated with lymphoma development. In order to elucidate the mechanisms underlying the proliferative processes, the events following infection of murine splenocytes or purified murine B lymphocytes in vitro have been examined. MHV-68 infection prolonged the viability of murine splenocytes and stimulated cellular proliferation. Unlike Epstein-Barr virus and herpesvirus saimiri, MHV-68 did not cause growth transformation. Growth transformation did not occur even when cells with a predisposition to transformation were infected or when culture conditions were selected to enhance the viability of the cells. Following MHV-68 infection, the latency-associated viral tRNAs were transcribed. However, transcription of the other known latency-associated gene, M2, was not observed. In addition, there was no evidence of productive virus replication either by staining with antibodies specific for late virus antigens or by in situ hybridization for early and late mRNAs. In contrast to Epstein-Barr virus- and herpesvirus saimiri-infected lymphocytes, where episomal genomes are seen, Gardella gel analysis indicated that the primary lymphocytes infected by MHV-68 in vitro contained only linear virus DNA. This DNA was nuclease sensitive, indicating that, while MHV-68 was efficiently uncoated, its circularization in vitro was extremely inefficient. These results are discussed in terms of the host-virus interaction.