This article focuses on bone cement, the cementing technique used, and their influence on aseptic loosening and infection of acrylic and joint implants--Scandinavian view.
There have been few comparative studies on total knee replacement (TKR) with cemented tibia and uncemented femur (hybrid TKR). Previous studies have not shown any difference in revision rate between cemented and hybrid fixation, but these studies had few hybrid prostheses. We have evaluated the outcome of hybrid TKR based on data from the Norwegian Arthroplasty Register (NAR).
We compared 4,585 hybrid TKRs to 20,095 cemented TKRs with risk of revision for any cause as the primary endpoint. We included primary TKRs without patella resurfacing that were reported to the NAR during the years 1999-2012. To minimize the possible confounding effect of prosthesis brands, only brands that were used both as hybrids and cemented in more than 200 cases were included. Kaplan-Meier survival analysis and Cox regression analysis were done with adjustment for age, sex, and preoperative diagnosis. To include death as a competing risk, cumulative incidence function estimates were calculated.
Estimated survival at 11 years was 94.3% (95% CI: 93.9-94.7) in the cemented TKR group and 96.3% (CI: 95.3-97.3) in the hybrid TKR group. The adjusted Cox regression analysis showed a lower risk of revision in the hybrid group (relative risk = 0.58, CI: 0.48-0.72, p
Thrombin formation commences perioperatively in orthopaedic surgery and therefore some surgeons prefer preoperative initiation of pharmacologic thromboprophylaxis. However, because of the potential for increased surgical bleeding, the postoperative initiation of thromboprophylaxis has been advocated to reduce blood loss, need for transfusion, and bleeding complications. Trials on timing of thromboprophylaxis have been designed primarily to detect thrombotic events, and it has been difficult to interpret the magnitude of blood loss and bleeding events owing to lack of information for bleeding volume and underpowered bleeding end points.
We therefore asked whether there are differences in blood loss, transfusion requirements, and other postoperative clinical complications with preoperative versus postoperative start of thromboprophylaxis with dalteparin.
In a double-blind, randomized controlled trial, 80 patients undergoing primary cemented THA were allocated to dalteparin injections starting 12 hours before or 6 hours after surgery. Blood loss was measured by weighing sponges and drapes, volume in suction drains during surgery, and wound drains until removal 24 hours postoperatively. Hemoglobin and hematocrit were recorded at predefined times during and after surgery.
We found no differences in blood loss (1081 mL ± 424 mL versus 1023 mL ± 238 mL), bleeding-related events (10% versus 17%), or number of patients who had transfusions (12 versus five) with preoperative and postoperative thromboprophylaxis, respectively. Other complications were few in both groups.
Our data suggest blood loss is similar with preoperative and postoperative initiation of dalteparin thromboprophylaxis, but indicate a trend toward fewer transfusion requirements which might favor postoperative start of thromboprophylaxis.
Cemented total hip replacement for primary osteoarthritis in patients aged 55 years or older: results of the 12 most common cemented implants followed for 25 years in the Finnish Arthroplasty Register.
We have analysed from the Finnish Arthroplasty Register the long-term survivorship of the 12 most commonly-used cemented implants between 1980 and 2005 in patients aged 55 years or older with osteoarthritis. Only two designs of femoral component, the Exeter Universal and the Müller Straight femoral component had a survivorship of over 95% at ten years with revision for aseptic loosening as the endpoint. At 15 years of the femoral and acetabular component combinations, only the Exeter Universal/Exeter All-poly implant had a survival rate of over 90% with revision for aseptic loosening as the endpoint. In the subgroup of patients aged between 55 and 64 years, survivorship overall was less than 90% at ten years. The variation in the long-term rates of survival of different cemented hip implants was considerable in patients aged 55 years or older. In those aged between 55 and 64 years, none of the cemented prostheses studied yielded excellent long-term survival rates (> or = 90% at 15 years).
A two-stage revision total knee arthroplasty is recognized as the gold standard in the treatment of infection. However, traditional spacers limit function in the interval between the two stages and may cause instability, scarring, and bone erosion. The PROSTALAC knee spacer is an antibiotic-loaded cement articulating spacer that allows some movement of the knee between stages. Whether motion enhances long-term function is unknown.
We therefore identify the rate of control of infection using the PROSTALAC exchange spacer and to assess the clinical outcome after implantation with a definitive implant.
We retrospectively reviewed 115 knees that underwent two-stage exchange with the PROSTALAC spacer. Forty-eight of these had a minimum followup of 5 years (mean, 9 years; range, 5-12 years).
At last review, 101 of the 115 knees (88%) had no evidence of infection. Of the 14 knees that became reinfected, four were from the same organism and 10 were with a different organism. After further intervention, using the two-stage approach again, the infection was controlled in 12 of the 14 initially reinfected cases, resulting in a failure to cure in only two cases. We observed improvements in mean WOMAC, Oxford, UCLA, and Patient Satisfaction scores at last review.
The PROSTALAC functional spacer was associated with a 98% rate of control of infection and improvements in the quality-of-life outcomes in the treatment of chronically infected total knee arthroplasties.
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
In the Norwegian Arthroplasty Register, 15,335 primary total hip replacements (THR) in patients with primary arthrosis were followed for 0-5.4 years. The Kaplan-Meier estimate of cumulative failure (revision) after 4.5 years was 2.7 percent for cemented THR, compared to 6.5 percent for uncemented. In patients under 65 years the cumulative revisions for cemented and uncemented THR were 3.3 and 7.9 percent. For the acetabular components, the cumulative failures were 0.6 percent for cemented and 1.7 percent for uncemented, and for femoral components 1.7 and 3.9 percent after 4.5 years. Adjusting for age and sex using a Cox regression model, 2 times higher rates of failure were found comparing uncemented to cemented THR. The results for uncemented prostheses were more unfavorable in young patients. In men and women under 60, the revision rates were increased 6 and 3 times, respectively, for patients with uncemented THR compared to those with cemented THR. Restriction of the end-point to revision for aseptic loosening gave results similar to the over-all results. No difference between cemented and uncemented THR was seen for revisions due to infection, whereas the most unfavorable results for uncemented THR were seen when revisions due to causes other than infection and aseptic loosening were considered.
The effect of hospital-type and operating volume on the survival of hip replacements. A review of 39,505 primary total hip replacements reported to the Norwegian Arthroplasty Register, 1988-1996.
We investigated associations between the survival of total hip replacements (THRs), type of hospital and annual number of THRs per hospital. The study was based on 39,505 primary THRs reported to the Norwegian Arthroplasty Register from 45 local (n 20,756), 15 central (n 12,455) and 10 university hospitals (n 6,294) during 1988-1996. The annual number of THRs was highest at central and university hospitals, both of which are training hospitals. University hospitals were further characterized by the lowest mean annual number of THRs performed per surgeon. For cemented THRs, with adjustment for gender, age, diagnosis, surgical procedure, and annual hospital volume, the revision rates at central and university hospitals were 0.8 (95% confidence interval: 0.67-0.95) and 1.2 (CI: 1.02-1.47) times that of local hospitals, respectively. A high annual number of cemented THRs per hospital was not associated with lower revision rates. In uncemented THRs, survival results were similar in central and local hospitals, whereas the adjusted revision rate at university hospitals was 1.6 (CI: 1.13-2.19) times that of local hospitals. The adjusted 6.5 year revision probability was 12% in hospitals performing 84 operations (n 526).
Exeter and charnley arthroplasties with Boneloc or high viscosity cement. Comparison of 1,127 arthroplasties followed for 5 years in the Norwegian Arthroplasty Register.
During the years 1991-1994, the Norwegian Arthroplasty Register recorded 1,324 primary hip arthroplasties implanted with the Boneloc cement. We have compared the survival until revision due to aseptic loosening for charnley (n 955) and Exeter (n 172) prostheses. The Boneloc cemented hips were also compared with high viscosity cemented hips implanted during the same period. In the Boneloc cemented group, the estimated probability of survival at 4.5 years of a Charnley femoral component was 74% and for an Exeter femoral component 97% (p
To compare the frequency and severity of heterotopic ossification (HO) in patients with osteoarthritis or rheumatoid arthritis who undergo cemented or noncemented total hip arthroplasty.
A prospective case study.
A university referral centre.
One hundred and sixty one patients underwent 184 total hip arthroplasties. The 184 hips were categorized as follows: cemented total hip arthroplasty--60 osteoarthritis hips, 26 hips affected by rheumatoid arthritis; noncemented total hip arthroplasty--67 osteoarthritic hips, 31 hips affected by rheumatoid arthritis.
Total hip arthroplasty. A standard approach was used to implant either a cemented or noncemented prosthesis. Radiographs were obtained of each hip preoperatively, immediately postoperatively and 6 weeks, 3 months, 6 months and 1 year postoperatively.
Radiographs were graded in blind fashion for HO, according to the criteria of Brooker. Modified Harris hip scores were calculated at 1 and 2 years postoperatively.
HO (incidence of Brooker grades 2, 3 and 4) was greater after cemented (22%) than noncemented (9%) total hip arthroplasty in osteoarthritic hips (p
Notes
Comment In: Can J Surg. 1994 Apr;37(2):89-908156476
We report the incidence of total hip replacements performed in Iceland between 1982 and 1996. During this period, 3,403 hip arthroplasties were done. The annual number of procedures increased from 94 hips in 1982 to 323 hips in 1996. Annual rates of total hip replacements due to primary osteoarthrosis per 10(5) inhabitants were 68 in 1982-1986, 90 in 1987-1991, and 114 in 1992-1996. In the years 1992-1996, the age-standardized incidence of total hip replacements for primary osteoarthrosis was 3/10(5) among patients younger than 39 years of age, while it was 621/10(5) among those 70-79 years of age. The mean age at surgery for primary osteoarthrosis was 69 years in both men and women. Incidence rates in various countries are difficult to compare, but by using age-standardized data and correction for differences in population structures between Iceland and Sweden, we find that the incidence of total hip replacement for primary osteoarthrosis of the hip is at least 50% higher in Iceland than in Sweden. This difference is consistent with the higher prevalence of hip osteoarthrosis observed in Iceland than in Sweden.
