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Background and purpose After joint replacement, a repair process starts at the interface between bone and cement. If this process is disturbed, the prosthesis may never become rigidly fixed to the bone, leading to migration—and with time, loosening. Cox-2 inhibitors are widely used as postoperative analgesics, and have adverse effects on bone healing. This could tamper prosthesis fixation. We investigated whether celecoxib, a selective Cox-2 inhibitor, increases prosthesis migration in total knee replacement (TKR).

Methods 50 patients were randomized to either placebo or celecoxib treatment, 200 mg twice daily, for 3 weeks after TKR (NexGen; Zimmer). Maximum total point motion (MTPM) of the tibial component was measured after 2 years using radiostereometric analysis (RSA). In addition, range of motion, pain, and, subjective outcome were evaluated.

Results No differences in prosthesis migration, pain scores, range of motion, and subjective outcome were found after 2 years. Confidence intervals were narrow.

Interpretation It is unlikely that Celecoxib increases the risk of loosening, and it may be used safely in conjunction with TKR.

Background and purpose

In a previous radiostereometric (RSA) trial the uncoated, uncemented, Interax tibial components showed excessive migration within 2 years compared to HA-coated and cemented tibial components. It was predicted that this type of fixation would have a high failure rate. The purpose of this systematic review and meta-analysis was to investigate whether this RSA prediction was correct.

Materials and methods

We performed a systematic review and meta-analysis to determine the revision rate for aseptic loosening of the uncoated and cemented Interax tibial components.

Results

3 studies were included, involving 349 Interax total knee arthroplasties (TKAs) for the comparison of uncoated and cemented fixation. There were 30 revisions: 27 uncoated and 3 cemented components. There was a 3-times higher revision rate for the uncoated Interax components than that for cemented Interax components (OR = 3; 95% CI: 1.4–7.2).

Interpretation

This meta-analysis confirms the prediction of a previous RSA trial. The uncoated Interax components showed the highest migration and turned out to have the highest revision rate for aseptic loosening. RSA appears to enable efficient detection of an inferior design as early as 2 years postoperatively in a small group of patients.

The amount of blood loss in a primary cemented total knee arthroplasty (TKA) seems to vary in different reported studies. We carried out a prospective study to determine the factors affecting the peri-operative blood loss, hidden blood loss and blood transfusion requirements in a primary cemented total knee arthroplasty. The factors analysed were gender, diagnosis, tourniquet time and body mass index (BMI). We included a total of 66 consecutive patients who underwent primary TKA by a single surgeon (A.M). There was significantly more peri-operative blood loss in male patients than in females (p=0.001, Student’s t test). The patients with rheumatoid arthritis did not show any statistical difference in peri-operative blood loss compared with that in patients with osteoarthritis. The tourniquet time and the surgical time showed a positive correlation with peri-operative blood loss. The BMI did not show any correlation with peri-operative blood loss. The incidence of blood transfusion was significantly higher in patients with rheumatoid knees as their pre-operative haemoglobin value was low. The amount of hidden blood loss in our series was 38%. We concluded that gender and tourniquet time plays a role in blood loss in TKA, but diagnosis (advanced osteoarthritis [OA] or rheumatoid arthritis (RA) does not. The blood transfusion depends on both pre-operative haemoglobin value and intra-operative blood loss. The post-operative transfusion trigger can be brought to 8.0 g% in a haemodynamically stable patient.

Purpose

The use of an intraoperative tourniquet for total knee arthroplasty (TKA) is a common practice. However, the effectiveness and safety are still questionable. A systematic review was conducted to examine that whether using a tourniquet in TKA was effective without increasing the risk of complications.

Methods

A comprehensive literature search was done in PubMed Medicine, Embase, and other internet database. The review work and the following meta-analysis were processed to evaluate the role of tourniquet in TKA.

Results

Eight randomized controlled trials and three high-quality prospective studies involving 634 knees and comparing TKA with and without the use of a tourniquet were included in this analysis. The results demonstrated that using a tourniquet could decrease the measured blood loss but could not decrease the calculated blood loss, which indicated actual blood loss. Patients managed with a tourniquet might have higher risks of thromboembolic complications. Using the tourniquet with late release after wound closure could shorten the operation time; whereas early release did not show this benefit.

Conclusions

The current evidence suggested that using tourniquet in TKA may save time but may not reduce the blood loss. Due to the higher risks of thromboembolic complications, we should use a tourniquet in TKA with caution.

Background and purpose

There is no standard for patient triage in total knee arthroplasty (TKA) based on joint functional characteristics. This is largely due to the lack of objective postoperative measurement of success in TKA in terms of function and longevity, and the lack of knowledge of preoperative metrics that influence outcome. We examined the association between the preoperative mechanical environment of the patients knee joint during gait and the post-TKA stability of the tibial component as measured with radiostereometric analysis (RSA).

Methods

37 subjects were recruited out of a larger randomized RSA trial. 3-dimensional gait analysis was performed in the preoperative week. Longitudinal RSA data were gathered postoperatively at 6 months and 1 year.

Results

We found a statistically significant association between the pattern of the knee adduction moment during gait preoperatively and the total migration of the implant at 6 months postoperatively. A substantial proportion of the variability in the total postoperative tibial component migration (R2 = 0.45) was explained by a combination of implant type, preoperative knee joint loading patterns during gait, and body mass index at 6 months postoperatively. The relationships did not remain statistically significant at 1 year postoperatively.

Interpretation

Our findings support the hypothesis that preoperative functional characteristics of patients, and particularly joint loading patterns during activities of daily living, are important for outcome in TKA. This represents a first step in the development of predictive models of objective TKA outcome based on preoperative patient characteristics, which may lead to better treatment strategies.

ClinicalTrials.gov (NCT00405379)

Background and purpose

In contrast to early migration, the long-term migration of hydroxyapatite- (HA-) coated tibial components in TKA has been scantily reported. This randomized controlled trial investigated the long-term migration measured by radiostereometric analysis (RSA) of HA-coated, uncoated, and cemented tibial components in TKA.

Patients and methods

68 knees were randomized to HA-coated (n = 24), uncoated (n = 20), and cemented (n = 24) components. All knees were prospectively followed for 11–16 years, or until death or revision. RSA was used to evaluate migration at yearly intervals. Clinical and radiographic evaluation was according to the Knee Society system. A generalized linear mixed model (GLMM, adjusted for age, sex, diagnosis, revisions, and BMI) was used to take into account the repeated-measurement design.

Results

The present study involved 742 RSA analyses. The mean migration at 10 years was 1.66 mm for HA, 2.25 mm for uncoated and 0.79 mm for the cemented group (p < 0.001). The reduction of migration by HA as compared to uncoated components was most pronounced for subsidence and external rotation. 3 tibial components were revised for aseptic loosening (2 uncoated and 1 cemented), 3 for septic loosening (2 uncoated and 1 cemented), and 1 for instability (HA-coated). 2 of these cases were revised for secondary loosening after a period of stability: 1 case of osteolysis and 1 case of late infection. There were no statistically significant differences between the fixation groups regarding clinical or radiographic scores.

Interpretation

HA reduces migration of uncemented tibial components. This beneficial effect lasts for more than 10 years. Cemented components showed the lowest migration. Longitudinal follow-up of TKA with RSA allows early detection of secondary loosening.

Average blood loss after total knee arthroplasty (TKA) usually ranges from 1500 to 1900 cc, including both the postoperative drain and hidden blood loss. This represents about 46% of TKA patients requiring postoperative blood transfusion. Not only the risks of disease transmission but also those of ABO incompatibility, infection due to immunosupression, increased procedure costs, and increased length of hospital stay, are potential problems that foster blood saving strategies. In this study, 71 unilateral TKAs using a multimodal protocol to decrease blood loss were compared to 61 historical cases. Patients in both groups underwent cemented TKA with the same system, surgical technique, and multimodal protocol (MIS approach, plug in the femoral canal, tourniquet removal after wound closure and compressive bandage, analgesic periarticular infiltration with vasoconstrictor, postoperative drain at atmospheric pressure, opened 2 hours after the end of the surgical procedure and removed after 24 hours). The study series incorporated intravenous tranexamic acid (TXA) infusion in 2 doses of 10-15 mg/kg, 15 minutes before tourniquet release and 3 hours later. Results showed no transfusion requirements in the TXA series (0%), with 23/61 (37.7%) transfusions in the control, with an average cost decrease of 240 euros per patient. Visible bleeding in 24h significantly decreased from 553.36 cc (range 50-1500) to 169.72 cc (range 10-480) in the TXA series. As a conclusion, implementing a TXA-based multimodal protocol produced significant decrease in the transfusion rate, visible blood loss, and cost per patient, thus proving effectiveness and efficiency in the surgical management of TKA.

There has been renewed interest for metal-on-metal hip resurfacing due to improved design and manufacturing of implants, better materials, and enhanced implant fixation. In contrast to conventional total hip replacements, only a few clinical hip resurfacing trials using radiostereometry (RSA) have been reported, and solely for the Birmingham hip resurfacing arthroplasty. The purpose of this RSA trial was to describe the migration pattern of a new hip resurfacing system (ReCap) within the first two years after primary surgery. Twenty-six patients underwent total hip replacement. The patients were followed-up for up to 24 months and were evaluated with the use of radiostereometric measurements. The prosthesis showed mean translations and rotation close to zero. Maximum translation was seen along the transverse axis in the medial direction (0.13 mm). No statistically significant translation or rotation was seen at two-years follow-up, (t-test, p <0.05, translation or rotation).

Background

Total knee arthroplasty (TKA) is widely recognized as an effective procedure for treatment of knee arthritis. However, there have been documented differences between men and women with respect to anatomic variability, timing of access to surgical care and surgical outcomes. We examined the influence of sex on the technical difficulty of TKA using a tourniquet and overall surgical time as a surrogate for complexity of exposure, soft-tissue balancing and implantation.

Methods

We performed a retrospective database review of patients who underwent primary TKA over a 5-year period. Tourniquet time, wound closure time and surgical time from 54 consecutive men (58 knees) and 48 women (58 knees) who underwent primary cemented TKA were recorded.

Results

The mean surgical time among men (108.2, standard deviation [SD] 17 min) was significantly longer than among women (96.8 [SD 14.8] min; p = 0.001). Similarly, the mean tourniquet time among men (75.9 [SD 11.7] min) was significantly longer than among women (65.9 [SD 11.8] min; p = 0.001).

Conclusion

Total knee arthroplasty in men requires more time than in women because of the complexity of exposure and to achieve the desired alignment of the components. Our data may allow a better resolution of surgery time planning, which could lead to better use of health system resources.

Background

Bioactive coating of uncemented total knee arthroplasty (TKA) is believed to increase bone ingrowth and enhance early fixation of the TKA. In a prospective randomized study using radiostereometric analysis (RSA) we examined migrations of the tibial implant, in an uncemented TKA with and without bioactive coating. The study was performed according to new RSA guidelines, and focus was put on some important methodological issues.

Materials and methods

Twenty-three patients with osteoarthrosis of the knee received an uncemented Duracon TKA either with bioactive (hydroxyapatite or periapatite) coating (+HA) or without bioactive coating (−HA). Patients had RSA examinations postoperatively and at 3, 6 and 12 months. Nine patients were excluded during the study resulting in 14 knees for final analysis.

Results

At 12 months follow-up we found no significant differences in migrations between the two groups. However, in general the −HA group migrated more than the +HA group, and we found a significant larger variation in migration pattern in the −HA group. In the +HA group the tibia component stabilized after 6 months, whereas the −HA group showed continuous migration. Subsidence and posterior tilt were the main migration patterns in both groups.

Conclusions

Bioactive coating of TKA seems to enhance early stabilization of the tibia component. Similar results are found in previous studies.

Blood loss after total knee arthroplasty (TKA) is often associated with cardiovascular complications and a high transfusion rate of allogenic blood. In our study we focused our attention on developing a new intra-surgical procedure that appears safe, easy to perform and effective in the reduction of bleeding in TKA. We evaluated 84 patients who underwent TKA and met our inclusion criteria; they were assigned to two groups: 55 controls in which a saline solution was used to wash the surgical field before tourniquet release, and a second group of 29 patients, in which a saline solution containing a low dose of norepinephrine was locally applied before tourniquet release. The local administration of a low dose of norepinephrine has induced a significant reduction of perioperative blood loss and blood transfusion requirements; in addition, this method was characterised by the absence of complications or adverse effects. In conclusion, our data suggest that intraoperative local administration of a low dose of norepinephrine could represent an effective and safe method of reducing blood loss and preventing blood transfusions in patients with TKA.

Background:

Tranexamic acid (TEA) reduces blood loss and red cell transfusions in patients undergoing unilateral total knee arthroplasty (TKA). However, there is not much literature regarding the use of TEA in patients undergoing bilateral TKA in a single stage and the protocols for administration of TEA in such patients are ill-defined.

Materials and Methods:

We carried out a case control study evaluating the effect of TEA on postoperative hemoglobin (Hb), total drain output, and number of blood units transfused in 52 patients undergoing bilateral TKA in a single stage, and compared it with 56 matched controls who did not receive TEA. Two doses of TEA were administered in doses of 10 mg / kg each (slow intravenous (IV) infusion), with the first dose given just before tourniquet release of the first knee and the second dose three hours after the first one.

Results:

A statistically significant reduction in the total drain output and requirement of allogenic blood transfusion in cases who received TEA, as compared to the controls was observed. The postoperative Hb and Hb at the time of discharge were found to be lower in the control group, and this result was found to be statistically significant.

Conclusion:

TEA administered in patients undergoing single stage bilateral TKA helped reduce total blood loss and decreased allogenic blood transfusion requirements. This might be particularly relevant, where facilities such as autologous reinfusion might not be available.

Summary

Total knee arthroplasty (TKA) is generally carried out using a tourniquet and blood loss occurring mainly post operatively is collected in drains. Tranexamic acid is an antifibrinolytic agent which decreases the total blood loss. Patients had unilateral / bilateral cemented TKA using combined spinal and epidural anaesthesia. In a double-blind fashion, they received either placebo (n=25) or tranexamic acid (n=25)10 mg.kg−1 i.v., just before tourniquet inflation, followed by 1 mg kg−1 h-1 i.v. till closure of the wound. The postoperative blood loss, transfusion requirement, cost effectiveness and complications were noted. The groups had similar characteristics. The mean volume of drainage fluid was 270 ml and 620 ml for unilateral(U/L) and bilateral(B/L) TKR patients in placebo group. Whereas it was 160ml and 286 ml respectively in unilateral(U/L) and bilateral(B/L) TKR patients who received tranexamic acid. This was considered statistically significant. Control group patients received 26 units of PRBC as compared to 4 units in tranexamic acid groups (p<0.001). This was again statistically significant. None of the patients in any of the groups developed deep vein thrombosis. Tranexamic acid decreased total blood loss by nearly 54% in B/L TKR and 40% in U/L TKR and drastically reduced (> 80%) blood transfusion.

Background

In recent years, the use of low molecular weight heparins such as dalteparin has become attractive because of their ease of administration and superiority in preventing venous thromboembolism (VTE) compared with traditional agents. The primary purpose of our study was to evaluate the impact of dalteparin use on blood loss and transfusion rates in patients undergoing primary total joint arthroplasty. We also evaluated the effect of patient sex, releasing the tourniquet in knee arthroplasty and the turnover of house staff.

Methods

Using our hospital transfusion database, we prospectively studied the mean reduction in hemoglobin and transfusion rates of 1642 consecutive patients who underwent primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) between January 2004 and December 2005. In 2004, warfarin was used exclusively for VTE prevention; however, in 2005, following the release of the 2004 American College of Chest Physicians’ guidelines, our centre began using dalteparin for VTE prophylaxis. We analyzed the impact of dalteparin use and the effect of patient sex, tourniquet release in TKA and house staff turnover months on blood loss and transfusion rates.

Results

The use of dalteparin for postoperative VTE prevention in patients undergoing THA and TKA in 2005 was associated with a significantly greater mean reduction in hemoglobin compared with warfarin use in 2004 (p = 0.014 for patients undergoing THA, p < 0.001 for patients undergoing TKA). The use of dalteparin in 2005 was not associated with a significant increase in allogeneic blood transfusions compared with the use of warfarin in 2004, except in women (p < 0.001). Although we observed no significant differences in mean reduction in hemoglobin between men and women undergoing THA, women undergoing THA had significantly higher transfusion rates regardless of the method of VTE prophylaxis (p = 0.037 for warfarin, p < 0.001 for dalteparin). Intraoperative tourniquet release in patients undergoing TKA was associated with a significantly lower mean reduction in hemoglobin than release after wound closure (p = 0.005). Although house staff turnover months were associated with a significantly greater mean reduction in hemoglobin levels than non-turnover months (p = 0.039), these months were not associated with a significant increase in allogeneic blood transfusions (p = 0.59).

Conclusion

Low molecular weight heparins such as dalteparin are the most common form of VTE prophylaxis in Canada. Our results suggest that dalteparin use, timing of tourniquet release and house staff turnover can all influence transfusion rates and/or blood loss in patients undergoing primary total joint arthroplasty. This study also emphasizes that women undergoing THA are at particularly high risk for blood transfusion.

We performed a prospective, randomized study on 76 patients (82 knees) scheduled for total knee arthroplasty to determine the effect of tourniquet release and hemostasis on the peri- and postoperative blood loss. Patients were randomly divided in two groups. Posterior cruciate retaining tricompartmental total knee prostheses were used in all. In group 1, the tourniquet was deflated intraoperatively after the prosthetic components were settled and hemostasis was done. In group 2, the tourniquet was released after the wound was closed and a compressive bandage was applied. Mean blood drainage was 880.85 ml (320–1,315) in group 1 and 745.36 ml (220–1,175) in group 2 (p=0.03). The mean number of blood transfusions given, hemoglobin and hematocrit values, operation time, and tourniquet time were similar in both groups. Intraoperative tourniquet release and hemostasis does not reduce total blood loss in total knee arthroplasty.

Background

Tourniquets are used to provide a bloodless surgical field for extremities. Hypotension due to vasodilation and bleeding after tourniquet deflation is a common event. Hemodynamic stability is modulated by the autonomic nervous system (ANS). Heart rate variability (HRV) is a sensitive method for detecting individuals who may be at risk of hemodynamic instability during general anesthesia. The purpose of this study was to investigate ANS function to predict hypotension after tourniquet deflation.

Methods

Eighty-six patients who underwent total knee replacement arthroplasty (TKRA) were studied. HRV, systolic blood pressure variability (SBPV) and baroreflex sensitivity (BRS) were analyzed. We assigned two groups depending on the lowest systolic blood pressure (SBP) or mean BP (MBP) after tourniquet release (Group H; SBP < 80 mmHg or MBP < 60 mmHg, Group S; SBP > 80 mmHg and MBP > 60 mmHg).

Results

Fifteen patients developed severe hypotension and ten patients were treated with ephedrine. Of the parameters of HRV, SBPV, and BRS, only BRSSEQ was significant being low in Group H. BRS and high-frequency SBPV were correlated with the degree of MBP change after tourniquet deflation.

Conclusions

Preoperative low BRS is associated with hypotension after tourniquet deflation, suggesting the importance of baroreflex regulation for intraoperative hemodynamic stability.

Background and purpose

The trabecular metal tibial monoblock component (TM) is a relatively new option available for total knee arthroplasty. We have previously reported a large degree of early migration of the trabecular metal component in a subset of patients. These implants all appeared to stabilize at 2 years. We now present 5-year RSA results of the TM and compare them with those of the NexGen Option Stemmed cemented tibial component (Zimmer, Warsaw IN).

Patients and methods

70 patients with osteoarthritis were randomized to receive either the TM implant or the cemented component. RSA examination was done postoperatively and at 6 months, 1 year, 2 years, and 5 years. RSA outcomes were translations, rotations, and maximum total point motion (MTPM) of the components. MTPM values were used to classify implants as “at risk” or “stable”.

Results

At the 5-year follow-up, 45 patients were available for analysis. There were 27 in the TM group and 18 in the cemented group. MTPM values were similar in the 2 groups (p = 0.9). The TM components had significantly greater subsidence than the cemented components (p = 0.001). The proportion of “at risk” components at 5 years was 2 of 18 in the cemented group and 0 of 27 in the TM group (p = 0.2).

Interpretation

In the previous 2-year report, we expressed our uncertainty concerning the long-term stability of the TM implant due to the high initial migration seen in some cases. Here, we report stability of this implant up to 5 years in all cases. The implant appears to achieve solid fixation despite high levels of migration initially.

INTRODUCTION

Wound ooze is common following total knee arthroplasty (TKA) and persistent wound infection is a risk factor for infection, and increased length and cost of hospitalisation.

PATIENTS AND METHODS

We undertook a prospective study to assess the effect of tourniquet time, peri-articular local anaesthesia and surgical approach on wound oozing after TKA.

RESULTS

The medial parapatellar approach was used in 59 patients (77%) and subvastus in 18 patients (23%). Peri-articular local anaesthesia (0.25% Bupivacaine with 1:1,000,000 adrenalin) was used in 34 patients (44%). The mean tourniquet time was 83 min (range, 38–125 min). We found a significant association between cessation of oozing and peri-articular local anaesthesia (P = 0.003), length of the tourniquet time (P = 0.03) and the subvastus approach (P = 0.01).

CONCLUSIONS

Peri-articular local anaesthesia, the subvastus approach and shorter tourniquet time were all associated with less wound oozing after total knee arthroplasty.

We hypothesized that patella eversion during total knee arthroplasty (TKA) reduces early return of active knee extension and flexion, quadriceps muscle strength, and postoperative pain. In 100 conventional TKA knees and 100 minimally invasive TKA (MIS TKA) knees, we compared knee range of motion (ROM), postoperative pain, and quadriceps muscle strength at 1 day, 4 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 12 weeks, 1 year, and 5 years after surgery. The differences of surgical approach between MIS TKA and conventional TKA of this study are length of skin incision with subcutaneal flap and patella eversion. In MIS TKA, skin incision is shorter than conventional TKA. Furthermore, patella is not everted in MIS TKA procedure. There were no significant differences in preoperative factors. Postoperative improvement of ROM, postoperative muscle strength recovery, and postoperative improvement of visual analog scale were faster in patients with MIS TKA when compared to that in patients with conventional TKA. On the other hand, no significant difference was observed in complication, 5-year clinical results of subjective knee function score, and the postoperative component angle and lower leg alignment. These results indicate that patella eversion may affect muscle strength recovery and postoperative pain.

Background

Tranexamic acid (TEA) reportedly reduces perioperative blood loss in TKA. However, whether it does so in minimally invasive TKA is not clear.

Questions/purposes

We asked whether TEA would reduce blood loss and blood transfusion requirements after minimally invasive TKA.

Patients and Methods

We prospectively enrolled 100 patients who underwent minimally invasive TKAs: 50 received one intravenous injection of TEA before deflation of the tourniquet and a control group of 50 patients received an equivalent volume of placebo. We compared changes in hemoglobin, postoperative drainage, total blood loss, and transfusion rates between the two groups.

Results

The total blood loss was less for patients in the TEA group than for the control group: 833 mL (374–1014 mL) versus 1453 mL (733–2537 mL), respectively. The rate of blood transfusion also was less for patients in the TEA group than in the control group (4% versus 20%). The hemoglobin levels on the second and fourth postoperative days were greater for patients in the TEA group than in the control group.

Conclusions

Our data suggest one intraoperative injection of TEA decreased the total blood loss and need for transfusion after minimally invasive TKA.

Level of Evidence

Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Background and purpose There are rising concerns about the frequency of infection after arthroplasty surgery. Prophylactic antibiotics are an important part of the preventive measures. As their effect is related to the timing of administration, it is important to follow how the routines with preoperative prophylactic antibiotics are working.

Methods In 114 consecutive cases treated at our own university clinic in Lund during 2008, the time of administration of preoperative prophylactic antibiotic in relation to the start of surgery was recorded from a computerized operation report. In 291 other cases of primary total knee arthroplasty (TKA), randomly selected from the Swedish Knee Arthroplasty Register (SKAR), the type and dose of prophylactic antibiotic as well as the time of administration in relation to the inflation of a tourniquet and to the start of surgery was recorded from anesthetic records.

Results 45% (95% CI: 36–54) of the patients operated in Lund and 57% (CI: 50–64) of the TKAs randomly selected from the SKAR received the preoperative antibiotic 15–45 min before the start of surgery. 53% (CI: 46–61) received antibiotics 15–45 min before inflation of a tourniquet.

Interpretation The inadequate timing of prophylactic antibiotics indicates that the standards of strict antiseptic and aseptic routines in arthroplasty surgery are falling. The use of a simple checklist to ensure the surgical safety may be one way of reducing infections in arthroplasty surgery.

OBJECTIVE:

To evaluate the association between tourniquet and total operative time during total knee arthroplasty and the occurrence of deep vein thrombosis.

METHODS:

Seventy-eight consecutive patients from our institution underwent cemented total knee arthroplasty for degenerative knee disorders. The pneumatic tourniquet time and total operative time were recorded in minutes. Four categories were established for total tourniquet time: <60, 61 to 90, 91 to 120, and >120 minutes. Three categories were defined for operative time: <120, 121 to 150, and >150 minutes. Between 7 and 12 days after surgery, the patients underwent ascending venography to evaluate the presence of distal or proximal deep vein thrombosis. We evaluated the association between the tourniquet time and total operative time and the occurrence of deep vein thrombosis after total knee arthroplasty.

RESULTS:

In total, 33 cases (42.3%) were positive for deep vein thrombosis; 13 (16.7%) cases involved the proximal type. We found no statistically significant difference in tourniquet time or operative time between patients with or without deep vein thrombosis. We did observe a higher frequency of proximal deep vein thrombosis in patients who underwent surgery lasting longer than 120 minutes. The mean total operative time was also higher in patients with proximal deep vein thrombosis. The tourniquet time did not significantly differ in these patients.

CONCLUSION:

We concluded that surgery lasting longer than 120 minutes increases the risk of proximal deep vein thrombosis.

We evaluated the average 7-year survivorship and clinical results of a newer primary posterior stabilized total knee arthroplasty (TKA). The modifications in this design included a deeper patellar sulcus aimed at reducing contact stresses, improving patellar tracking, and achieving greater maximum flexion. A consecutive group of 137 patients (171 knees) who underwent TKAs using the Optetrak PS knee prosthesis between October 1997 and March 2004 were followed for an average of 6.8 years (range 4.0–11.5 years). Preoperative range of motion (ROM) and Knee Society scores were obtained and compared to that of the patients’ most recent follow-up. Manipulation under anesthesia (MUA) and revision of the implant for any reason were considered endpoints for Kaplan–Meier survival analysis of all knees. Twenty-one knees (12.3%) underwent MUA. Three knees (1.8%) underwent revision, resulting in a 97.2% survival at a mean 10 years follow-up. Pain scores and ROM significantly improved after surgery (from preoperative average of 5.3 and 105° respectively to 44.6 and 120° postoperatively). These findings suggest that this posterior stabilized knee design is both a safe and effective option for patients undergoing primary TKA.

The main goals of TKA are pain relief and improvement of function and range of motion (ROM). To ascertain whether TKA in patients with stiff knees would relieve pain and improve functional outcome and ROM, we asked four questions: whether (1) Knee Society and WOMAC scores would improve after TKA; (2) poor preoperative ROM would improve after TKA; (3) the revision rate of TKA in stiff knees would be high; and (4) complication rates would be high in these patients after TKA. We retrospectively reviewed 74 patients (86 knees) with stiff knees (mean age, 56.8 years) who underwent TKAs with a condylar constrained or a posterior stabilized prosthesis. The minimum followup was 5 years (mean, 9.1 years; range, 5–12 years). The mean preoperative Hospital for Special Surgery knee score and Knee Society knee and functional scores were 42, 11, and 42 points, respectively, and postoperatively they were 84, 90, and 84 points, respectively. Preoperative and postoperative total WOMAC scores were 73 and 34 points, respectively. One knee (1.2%) had aseptic loosening of the tibial component and 12 knees (14%) had complications. Despite a relatively high rate of complications, most patients had substantial improvement in function.

Levels of Evidence: Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Background

Total knee replacement is now the most common joint replacement procedure performed in Ontario, and many patients require bilateral replacement. However, whether bilateral total knee arthroplasty (TKA) should be staged or simultaneous is hotly debated. To determine the current common operative practices of orthopedic surgeons in Ontario, we carried out a province-wide survey.

Methods

Orthopedic surgeons from Ontario listed in the 1999 Canadian Medical Directory or the membership list of the Canadian Orthopaedic Association were sent questionnaires, asking about their practice in the timing of bilateral TKA, tourniquet use, type of guide and use of techniques to minimize fat embolization.

Results

Of the 416 surveys mailed, 219 (53%) surgeons responded. The majority responded that they perform staged bilateral TKA (28% 3-mo interval and 37% 6-mo interval). Simultaneous TKA with 2 teams was the least performed procedure (2%). When performing bilateral TKA, 95% of surgeons use an intramedullary femoral alignment guide, 78% utilize an over-reamed entry hole and 53% suction the canal before inserting the guide rod. With respect to the tibia, 32% use an intramedullary guide, 60% over-ream the entry hole and 60% suction the entry hole; 22% of surgeons stated that they had never considered over-reaming or suctioning the canal to minimize fat embolization.

Conclusions

There is no consensus regarding the timing of bilateral TKA in Ontario. Furthermore, many surgeons are not overdrilling or suctioning the femoral canal despite evidence in the literature that overdrilling may be beneficial in decreasing fat embolization. Further research is required to compare the risk of complications of bilateral TKA after staged versus simultaneous TKA.