Fixation of the tibial component using CMW-1 or Palacos bone cement with gentamicin: similar outcome in a randomized radiostereometric study of 51 total knee arthroplasties

Routine use of commercial antibiotic-loaded bone cement in primary total joint arthroplasty: a critical analysis of the current evidence

Antibiotic-loaded cement (ABLC) has been widely utilized as an adjuvant treatment for patients with periprosthetic joint infection (PJI) but has also evolved to play a prophylactic role against infection in primary total joint arthroplasties (TJA). Nevertheless, there is currently a paucity of studies that systematically investigated this concept. This review aimed at answering the following questions: (I) Can routine use of ABLC help reduce the current infection rates in primary TJA? (II) What are the risks associated with this approach? And (III) can routine use be justified in primary TJA from an economic standpoint? Multiple databases were queried including PubMed, EMBASE, EBSCO Host, and SCOPUS. Studies published between January 1, 1990 and March 31, 2018 were reviewed. Inclusion criteria were studies reporting: (I) clinical outcomes of routine use of ABLC in primary hip and knee arthroplasty with 2-year minimum follow-up, (II) complications related to the use of ABLC, (III) cost of using ABLC. The final analysis included 24 studies. Data from multiple studies demonstrate contradictory results for infection rates when ABLC is used in all primary procedures with a majority of studies showing similar infection rates between ABLC and plain cement. The main concerns associated with routine use of ABLC are negative effects on the mechanical stability of cement, possible systemic and local toxicity of the absorbed antibiotic, and development of resistant bacterial strains. However, current literature has not clinically validated these concerns. Lastly, with an estimated increase in 117 million dollars with the routine use of ABLC in only 50% of TJAs performed each year, it is difficult to justify the use of ABLC without clear superiority in reducing infection. The use of ABLC has undeniably changed the way orthopaedic surgeons deal with PJI today. However, the large-scale, prophylactic use of ABLC in primary TJAs requires further research and justification.

RSA migration of total knee replacements

Purpose - We performed a systematic review and meta-analyses to evaluate the early and long-term migration patterns of tibial components of TKR of all known RSA studies. Methods - Migration pattern was defined as at least 2 postoperative RSA follow-up moments. Maximal total point motion (MTPM) at 6 weeks, 3 months, 6 months, 1 year, 2 years, 5 years, and 10 years were considered. Results - The literature search yielded 1,167 hits of which 53 studies were included, comprising 111 study groups and 2,470 knees. The majority of the early migration occurred in the first 6 months postoperatively followed by a period of stability, i.e., no or very little migration. Cemented and uncemented tibial components had different migration patterns. For cemented tibial components there was no difference in migration between all-poly and metal-backed components, between mobile bearing and fixed bearing, between cruciate retaining and posterior stabilized. Furthermore, no difference existed between TKR measured with model-based RSA or marker-based RSA methods. For uncemented TKR there was some variation in migration with the highest migration for uncoated TKR. Interpretation - The results from this meta-analysis on RSA migration of TKR are in line with both the survival analyses results from joint registries of these TKRs as well as revision rates results from meta-analyses, thus providing further proof for the association between early migration and late revision for loosening. The pooled migration patterns can be used both as benchmarks and for defining migration thresholds for future evaluation of new TKR.

Antibiotic bone cement’s effect on infection rates in primary and revision total knee arthroplasties

AIM

To compare infection rates in primary and revision total knee arthroplasty (TKA) procedures using antibiotic impregnated bone cement (AIBC) to those rates in procedures not using AIBC.

METHODS

A systematic review and meta-analysis was conducted in search for randomized controlled trials/studies (RCTs) pertaining to the field of antibiotic AIBC vs non-AIBC groups in both primary and revision TKA procedures. The primary literature search performed was to identify all RCTs that assessed AIBC in primary and revision TKA procedures. This search was done strictly through the PubMed database using the article “filters” setting that identified and separated all RCTs from the overall search. The original search was “Primary/revision total knee arthroplasty using AIBC”. Other key terms and phrases were included in the search as well. Eligible articles that were used in the “results” of this review met the following criteria: (1) Involved primary or revision TKA procedures (for any reason); (2) included TKA outcome infection rate information; (3) analyzed an AIBC group vs a non-AIBC control group; (4) were found through the RCT filter or hand search in PubMed; and (5) published 1985-2017. Exclusion criteria was as follows: (1) Patients that were not undergoing primary or revision TKA procedures; (2) articles that did not separate total hip arthroplasity (THA) vs TKA results if both hip and knee revisions were evaluated; (3) papers that did not follow up on clinical outcomes of the procedure; (4) extrapolation of data was not possible given published results; (5) knee revisions not done on human patients; (6) studies that were strictly done on THAs; (7) articles that were not found through the RCT filter or through hand search in PubMed; (8) articles that did not evaluate AIBC used in a prosthesis or a spacer during revision; (9) articles that did not compare an AIBC group vs a non-AIBC control group; and (10) articles that were published before 1985.

RESULTS

In total, 11 articles were deemed eligible for this analysis. Nine of the 11 studies dealt with primary TKA procedures comparing AIBC to non-AIBC treatment. The other two studies dealt with revision TKA procedures that compared such groups. From these papers, 4092 TKA procedures were found. 3903 of these were primary TKAs, while 189 were revision TKAs. Of the 3903 primary TKAs, 1979 of these used some form of AIBC while 1924 were part of a non-AIBC control group. Of the 189 revision TKAs, 96 of these used some form of AIBC while 93 were part of a non-AIBC control group. Average follow-up times of 47.2 mo and 62.5 mo were found in primary and revision groups respectively. A two-tailed Fisher’s exact test was done to check if infection rates differed significantly between the groups. In the primary TKA group, a statistically significant difference between AIBC and non-AIBC groups was not found (AIBC infection rate = 23/1979, non-AIBC infection rate = 35/1924, P = 0.1132). In the revision TKA group, a statistically significant difference between the groups was found (AIBC infection rate = 0/96, non-AIBC infection rate = 7/93, P = 0.0062). No statistically significant differences existed in Knee Society Scores, Hospital for Special Surgery Scores, or Loosening Rates.

CONCLUSION

AIBC did not have a significant effect on primary TKA infection rates. AIBC did have a significant effect on revision TKA infection rates.

Tibial component rotation around the transverse axis measured by radiostereometry predicts aseptic loosening better than maximal total point motion

Background and purpose - Maximal total point motion (MTPM) measured by radiostereometry (RSA) is widely used as a predictor of total knee arthroplasty (TKA) loosening. We compared the ability of different RSA measurements at different time points to predict loosening of tibial TKA components in the long term. Patients and methods - 116 TKAs in 116 patients were included in our analysis. 16 (14.8-17.4) years after surgery, 5 tibial components had been revised due to aseptic loosening. Receiver operating characteristic curves were calculated in order to investigate the specificity and sensitivity of different RSA parameters at different thresholds. Results - Rotation around the transverse (x-) axis measured 2 years postoperatively had the best predictive value of all parameters, with an area under the curve (AUC) of 80%. Using a threshold of 0.8 degrees, a specificity of 85% and a sensitivity of 50% were reached. The AUC for tibial component distal translation was 79% and it was 77% for proximal translation, whereas it was only 68% for MTPM. Interpretation - Rotation of the cemented tibial component around the transverse axis, proximal translation, and distal translation are slightly better at predicting aseptic loosening than MTPM, and tibial component migration measured after 2 years gives a good prediction of aseptic loosening up to 15 years.

Antibiotics and antiseptics for preventing infection in people receiving revision total hip and knee prostheses: a systematic review of randomized controlled trials

BACKGROUND

Infection rates in revision (second and subsequent) major joint arthroplasty continues to be a significant issue with rates 2-3 times those of primary procedures. The effect of antibiotic and antiseptic prophylaxis on outcomes for this type of surgery has not been adequately reviewed.

METHODS

A systematic search of the main databases for randomized controlled trials (RCTs) evaluating antibiotics and antiseptics was conducted to evaluate the predetermined endpoints of infection.

RESULTS

There were five (5) RCTs identified that examined the effects of antibiotic and antiseptic prophylaxis on infections after revision total hip arthroplasty [THA] (total of 304 participants) and total knee arthroplasty [TKA] (total of 206 participants). For TKA, preoperative systemic intravenous (IV) antibiotic prophylaxis plus antibiotic cement may be effective in reducing the incidence of infection in revision TKA at 8+ years. These results however should be interpreted with caution due to the significant biases. For revision THA, there is no RCT evidence that antibiotics/antiseptics have any effect on the infection rate.

CONCLUSIONS

There is a lack of high quality data demonstrating an effect of antibiotics or antiseptics on infection rates in revision THA/TKA. Considering the rate of infections in revisions is 2-3X that of primary procedures and; there is a consensus recommendation to use similar antibiotic and antiseptic regimens in both primary and revision procedures, there is a need for high quality studies in revision THA/TKA.

Initial stability of a new cementless fixation method of a tibial component with polyaxial locking screws: a biomechanical in vitro examination

INTRODUCTION

Cementless fixation of the tibial component is critical as reduced initial stability leads to implant failure. In this experimental in vitro study, a new fixation method of the tibial component using polyaxial locking screws is evaluated using Roentgen stereophotogrammetric analysis (RSA).

MATERIALS AND METHODS

A special prototype of a tibial component with four polyaxial locking screws was tested on 10 fresh-frozen human tibia specimens. The components were tested with an axial load of 2000 N for 10,000 cycles. Radiographs in two views were performed before loading, after 1000 and after 10,000 cycles, respectively. Besides rotation and translation along the x-, y-, and z-axes, endpoints for RSA were maximum subsidence (MaxSub), maximum lift off (MaxLiftOff) and maximum total point motion (MTPM).

RESULTS

MaxSub increased from -0.5 mm (SD = 0.2) after 1000 cycles to -0.9 mm (SD = 1.1). MaxLiftOff was 0.1 mm after 1000 cycles and did not increase after 10,000 cycles. The MTPM was 0.7 mm (SD = 0.3) after 1000 cycles and 1.1 mm (SD = 1.1) after 10,000 cycles. Two out of nine implants showed an MTPM ≥ 1.0 mm after 10,000 cycles.

CONCLUSIONS

Polyaxial locking screws can potentially improve the initial stability of tibial components. The results of this study indicate that the use of such screws in total knee arthroplasty may be of interest in the future. Further experimental and clinical investigation is needed.

Use of antibiotic-loaded cement in total knee arthroplasty

Bone cement has the capacity to release antibiotic molecules if any antibiotic is included in it, and these elution properties are improved as cement porosity is increased. In vitro studies have shown high local antibiotic concentration for many hours or few days after its use. Antibiotic loaded bone cement (ALBC) is helpful when treating an infection in total knee arthroplasty (TKA) revision surgery. The purpose of this paper was to review the evidence for the routine use of ALBC in TKA in the literature, its pros and cons. Many authors have recommended the use of ALBC also in primary TKA for infection prophylaxis, but the evidence based on data from National Registries, randomized clinical trials and meta-analysis suggest a protective effect of ALBC against infection when used in hips, but not (or only mild) in knees. A possible explanation to this finding is that the duration and quantity of locally elevated antibiotic levels after surgery are smaller in TKA, due to the smaller amount of cement used for fixation in TKA-only a layer in the bone surface. There are some concerns about the routine use of ALBC in primary TKA as prophylaxis against infection: Firstly, there is a risk of hypersensivity or toxicity even when the chance is highly improbable. Secondly, there is a reduction in the mechanical properties of the cement, but this can be probably neglected if the antibiotic is used in low doses, not more than 1 g per 40 g cement package. Another significant concern is the increased economic cost, which could be overlooked if there were enough savings in treating fewer prosthetic infections. Finally, there is also a risk of selection of antibiotic-resistant strains of bacteria and this could be the main concern. If used, the choice of the antibiotic mixed in ALBC should consider microbiological aspects (broad antimicrobial spectrum and low rate of resistant bacteria), physical and chemical aspects (thermal stability, high water solubility), pharmacological characteristics (low risk to allergic reactions or toxicity) and economic aspects (not too expensive). The most commonly used antibiotics in ALBC are gentamicin, tobramycin and vancomycin. In conclusion, there is a paucity of randomized clinical trials in the use of ALBC in primary TKAs and the actual evidence of the effect of ALBC in reducing the risk of infection is insufficient. This, in addition to concerns about patient safety, risks of increase in the antibiotic resistance of microorganisms and the increase in costs in the procedure, lead us to recommend a cautious use of ALBC, perhaps only in high-risk patients (immunocompromised, morbidly obese, diabetic and patients with previous history of fracture or infection around the knee) unless the benefits of ALBC use were fully proven. Meanwhile, the rigorous use of peri-operative prophylactic systemic antibiotics and adoption of efficient antiseptic procedures and improved surgical techniques must be considered the gold standard in infection prevention in TKA surgery.

Adherence of hip and knee arthroplasty studies to RSA standardization guidelines. A systematic review

BACKGROUND AND PURPOSE

Guidelines for standardization of radiostereometry (RSA) of implants were published in 2005 to facilitate comparison of outcomes between various research groups. In this systematic review, we determined how well studies have adhered to these guidelines.

METHODS

We carried out a literature search to identify all articles published between January 2000 and December 2011 that used RSA in the evaluation of hip or knee prosthesis migration. 2 investigators independently evaluated each of the studies for adherence to the 13 individual guideline items. Since some of the 13 points included more than 1 criterion, studies were assessed on whether each point was fully met, partially met, or not met.

RESULTS

153 studies that met our inclusion criteria were identified. 61 of these were published before the guidelines were introduced (2000-2005) and 92 after the guidelines were introduced (2006-2011). The methodological quality of RSA studies clearly improved from 2000 to 2011. None of the studies fully met all 13 guidelines. Nearly half (43) of the studies published after the guidelines demonstrated a high methodological quality and adhered at least partially to 10 of the 13 guidelines, whereas less than one-fifth (11) of the studies published before the guidelines had the same methodological quality. Commonly unaddressed guideline items were related to imaging methodology, determination of precision from double examinations, and also mean error of rigid-body fitting and condition number cutoff levels.

INTERPRETATION

The guidelines have improved methodological reporting in RSA studies, but adherence to these guidelines is still relatively low. There is a need to update and clarify the guidelines for clinical hip and knee arthroplasty RSA studies.

A systematic review and meta-analysis of antibiotic-impregnated bone cement use in primary total hip or knee arthroplasty

Background

Antibiotic-impregnated bone cement (AIBC) has been widely used for the treatment of infected revision arthroplasty, but its routine use in primary total joint arthroplasty (TJA) remains considerably controversial. With this meta-analysis of published randomized controlled trials, we intended to assess the antimicrobial efficacy and safety of AIBC for its prophylactic use in primary TJA.

Methods

A literature search was performed in MEDLINE, Embase, CBMdisc and the Cochrane Library until June, 2013. The studies were divided into two sub-groups according to the type of the control group. Outcomes of interest included postoperative infection rates, radiographic outcomes and clinical joint score. Study quality was evaluated using the Jadad scale (five points).

Results

In total, eight studies were included, with a sample size of 6,381 arthroplasties. The overall pooled data demonstrated that, compared with the control (plain cement or systemic antibiotic), AIBC did not reveal an advantage in decreasing the rate of superficial infection (relative risk [RR] = 1.47; 95% CI, 1.13–1.91; P=0.004), while there were significant differences in deep infection rate between the AIBC and control group (RR = 0.41; 95% CI, 0.17–0.97; P=0.04). For the analysis of gentamicin and cefuroxime subgroups, the gentamicin was superior to the cefuroxime in reducing deep infection rate (P=0.0005 versus P= 0.10). However, no significant differences were found in their radiographic outcomes and clinical joint score.

Conclusion

This meta-analysis had proven that the prophylactic use of AIBC could lower the deep infection rate in primary TJA, while AIBC did not show an improvement in reducing the superficial infection rate compared with the control. More sufficiently powered studies would be required to further evaluate the efficacy and safety of AIBC for primary TJA.

Tibial cleaning method for cemented total knee arthroplasty: An experimental study

BACKGROUND

The survival rate of cemented knee prosthesis depends among other factors on optimal cement-bone contact, nevertheless no standard exists for cementing technique of tibial components. The aim of this study was to determine which tibial surface preparation technique leads to the best bone-cement contact.

MATERIALS AND METHODS

HUMAN TIBIAL PLATEAU SPECIMENS WERE CLEANED IN FOUR DIFFERENT WAYS BEFORE CEMENTING: a) no cleaning, b) manual syringe irrigation, c) fracture brush cleaning, and d) pulsatile jet-lavage. The specimens were cut into transverse sections and the bone cement contact distance was calculated for every 10 mm and the cement penetration depth was measured. Both values were statistically analyzed (ANOVA).

RESULTS

The longest bone-cement contact (62 mm) was seen after PJL, the shortest (10.6 mm) after no cleaning at all. The deepest cement penetration (4.1 mm) again was seen after PJL, the least (0.7 mm) after no cleaning. Statistically, PJL yielded the longest bone-cement contact and deepest cement penetration.

CONCLUSION

The results supports the use of pulsatile jet-lavage before cementing tibial components in knee arthroplasty.

Early migration of tibial components is associated with late revision: a systematic review and meta-analysis of 21,000 knee arthroplasties

PURPOSE

We performed two parallel systematic reviews and meta-analyses to determine the association between early migration of tibial components and late aseptic revision.

METHODS

One review comprised early migration data from radiostereometric analysis (RSA) studies, while the other focused on revision rates for aseptic loosening from long-term survival studies. Thresholds for acceptable and unacceptable migration were determined according to that of several national joint registries: < 5% revision at 10 years.

RESULTS

Following an elaborate literature search, 50 studies (involving 847 total knee prostheses (TKPs)) were included in the RSA review and 56 studies (20,599 TKPs) were included in the survival review. The results showed that for every mm increase in migration there was an 8% increase in revision rate, which remained after correction for age, sex, diagnosis, hospital type, continent, and study quality. Consequently, migration up to 0.5 mm was considered acceptable during the first postoperative year, while migration of 1.6 mm or more was unacceptable. TKPs with migration of between 0.5 and 1.6 mm were considered to be at risk of having revision rates higher than 5% at 10 years.

INTERPRETATION

There was a clinically relevant association between early migration of TKPs and late revision for loosening. The proposed migration thresholds can be implemented in a phased, evidence-based introduction of new types of knee prostheses, since they allow early detection of high-risk TKPs while exposing only a small number of patients.

Tibial component fixation with a peri-apatite coating: evaluation by radiostereometric analysis in a canine total knee arthroplasty model

Cementless fixation for the tibial component in total knee arthroplasty (TKA) remains problematic. Peri-Apatite (PA), a solution-deposited hydroxyapatite, is under investigation as an option for improving the fixation of cementless tibial components. In this study, radiostereometric analysis was used to document implant migration in 48 dogs that underwent TKA with cementless, PA-coated, or cemented tibial components. Migration at 12 weeks was similar in the 2 groups. At 12 months, there was greater migration in the PA-coated group, but the difference between the 2 groups was below the threshold considered clinically significant. In this canine TKA model, cementless fixation with PA performed less well than did cemented fixation, but not to a degree that would make a clinical difference in the short term.

The effect of adding tobramycin to Simplex P cement on femoral stem micromotion as measured by radiostereometric analysis: a 2-year randomized controlled trial

BACKGROUND

Previous in vitro research on addition of antibiotics to bone cement has found no statistically significant deterioration in mechanical properties. However, no clinical studies have compared the performance of tobramycin-laden bone cement with that of standard bone cement (Simplex P).

PATIENTS AND METHODS

23 patients (25 hips) were randomized to receive an Exeter (Stryker Orthopaedics) femoral stem cemented with either Simplex P (standard) or Simplex T (tobramycin-laden) cement. There were 2 years of follow-up, with scheduled radiostereometric (RSA) examinations.

RESULTS

All stems migrated distally and showed some degree of retroversion. No clinically significant differences in stem subsidence or retroversion were found between the Simplex T and Simplex P cement groups after 2 years. Overall subsidence was less than in previous studies, probably due to a postponed initial post-surgical examination. Rates of subsidence in both cement groups were consistent with those from previous studies of Exeter stems.

INTERPRETATION

Subsidence of the femoral stem after 2 years was similar in the Simplex T (tobramycin-laden) and Simplex P (standard) groups.

Revision of tibial TKA components: bone loss is independent of cementing type and technique: an in vitro cadaver study

BACKGROUND

Different bone cements and various cementation techniques can lead to different bone loss in revision surgery. We investigated the degree of tibial bone loss depending on different cements and techniques.

METHODS

30 tibia specimens were matched into three groups (10 each). In all cases Genesis II tibia component were implanted. In two groups, the tibia base plate alone was cemented with Palacos® R+G and Refobacin® Bone Cement R. In the third group, both tibial base plate and tibial stem were cemented with Palacos® R+G. Afterwards, the specimens were axial loaded with 2000 N for 10,000 cycles. Tibial components were explanted and the required time to explantation was recorded. Bone loss after explantation was measured by CT.

RESULTS

On CT, there was no significant difference in bone loss between cementing techniques (p = 0.077; 95% CI -1.14 - 21.03) or the cements themselves (p = 0.345; 95% CI -6.05 - 16.70). The required time to explantation was 170.6 ± 54.89, 228.7 ± 84.5, and 145.7 ± 73.0 seconds in the first, second, and third groups, respectively.

CONCLUSIONS

Cement technique and type do not influence tibial bone loss in simulated revision surgery of the tibial component in knee arthroplasty.

Prophylactic use of antibiotic-loaded bone cement in primary total knee replacement

Despite significant advances in intraoperative antimicrobial procedures, deep infection remains the most devastating complication following total joint arthroplasty. Clinical studies' results and safety profile of antibiotic-loaded bone cement are discussed in this review. Antibiotic bone cement prophylaxis is a safe and effective strategy in reducing the risk of deep infection following primary total joint arthroplasty.

Primary stability of tibial components in TKA: in vitro comparison of two cementing techniques

In spite of improvements in cementing technique, migration of tibial component remains a problem in total knee arthroplasty. This study compares the primary stability of tibial components using two different cementing techniques with roentgen stereophotogrammetric analysis (RSA) in vitro. A total of 20 tibia specimens were matched into two groups, 10 specimens per group. Cementing technique was randomized to each group. In the first group only the base and in the second group the base and stem were cemented. The implants and the tibial metaphysis were marked with markers for the RSA analysis. All specimens were tested with an axial load of 2,000 N for 1,000 and 10,000 cycles and RSA analysis was performed. Endpoints for radiosterometric analysis were maximum total point motion, maximum subsidence, lift off, rotation and translation along the x-, y-, and z-axes. After 1,000 and 10,000 cycles, no significant differences could be found, but two tibial components of the surface cementing group showed a migration of more than 2 mm defined as failure compared to six failed tibial components in the full cementing group (P = 0.068). This higher number of failed arthroplasties in the fully cemented prosthesis group demonstrates a disadvantageous load distribution in the tibia apophysis which can cause an early component loosening.

Antibiotic bone cement and the incidence of deep infection after total knee arthroplasty

We asked if the use of antibiotic-laden bone cement (ALBC) decreased the deep infection rate after primary total knee arthroplasty as compared to plain bone cement. We surveyed 1625 consecutive patients for relevant covariates. Joint pain and function were assessed at baseline and at 1 year of follow-up with the Western Ontario McMaster University Osteoarthritis Index scores. The incidence of deep infection at 1-year follow-up was recorded. There were no differences in baseline covariates between groups (P > .05). We found a deep infection rate of 2.2% in the ALBC group and 3.1% in the plain bone cement group (P = .27). Adjusted analysis showed that ALBC was not predictive of a lower infection rate at 1 year (P = .84). Antibiotic-laden bone cement did not reduce the incidence of deep infection following primary total knee arthroplasty at 1-year follow-up.

[Quality of tibial cementing in total knee arthroplasty: one or two phase cementing of the tibial and femoral implants]

PURPOSE OF THE STUDY

When implanting a total knee prosthesis, the tibial component can be cemented either independently in the flexion position by maintaining an axial force on the implant, or simultaneously in extension by applying a compression force on both the tibial and femoral implants after reducing the prosthesis. The purpose of this study was to determine whether the quality of the cementing depends on the method used: independently in the flexion position, or simultaneously in the extension position.

MATERIAL AND METHODS

This was a prospective comparative study between two groups of 20 patients assigned alternatively to one of two study arms: Group 2 with a tibial implant cemented independently and Group 1 with a tibial implant cemented simultaneously with the femoral implant. The cancellous surfaces were prepared by irrigation and gravity flow wash-out. Aspiration of the cancellous section surface was maintained until the radio-opaque cement with standard viscosity (CMW3) was inserted. The penetration of cement into the cancellous bone was noted by zone on the postoperative radiographs (seven days and one month). Implant position, presence of early lucent lines and cement debris were noted. Radiographs were taken under fluoroscopic guidance in order to obtain the best image of the joint space and the tibial plateau.

RESULTS

Cement penetration into the tibial plateau was significantly more pronounced in Group 2 for zones 1, 2 (p<0.01) and 3 (p<0.05) on the above proof view. Early translucent lines were noted in 15 of 20 knees in Group 1 (p<0.01). Cement debris and microfractures were noted in five knees in Group 1 (one in Group 2). The position of the implants was not affected by the method used for cementing.

CONCLUSION

This study demonstrates the theoretical and radiographic interest of cementing the tibial piece independently with the knee in the flexion position for total knee replacement. It is important to apply sustained pressure to obtain good quality cement-bone interpenetration.

Mechanical bond strength of the cement-tibial component interface in total knee arthroplasty

The purpose of this study was to mechanically test the cement-tibial component interface using titanium and cobalt-chrome sample prostheses with several commercially available surface textures. The results of this study indicate that the type of metal substrate and surface preparation of contemporary tibial baseplates may influence the strength of the metal-cement interface and as such influence tibial component survival. The results indicate that, in general, metal-cement interface strength increases with increasing surface roughness and common surface treatments such as AlO2 grit-blasting (Ra = 6.76 microm) produce interface strengths similar to plasma-spray, porous-coated specimens. Macrosurfaced tibial components, although comparable in tension, may be vulnerable to metal-cement interface failure with rotational loading.

Prophylactic use of antibiotic bone cement: an emerging standard--in the affirmative

Deep infection is a devastating complication following total joint arthroplasty. Preclinical testing; randomized; clinical trials; national joint replacement data; and our experience indicate that the use of antibiotic-impregnated bone cement is a potentially effective strategy in reducing the risk of deep infection following both primary and revision total joint arthroplasty. Allergic reactions, bacterial resistance, and cost represent barriers to the widespread use of antibiotic bone cement.