Blood transfusion after primary total knee arthroplasty can be significantly minimised through a multimodal blood-loss prevention approach

Purpose

Our aim was to clarify the effective decrease in blood transfusion after primary total knee arthroplasty (TKA) from a multimodal blood-loss prevention approach (MBLPA) and the related risk factors of blood transfusion.

Methods

We retrospectively compared the rate of postoperative blood transfusion in 418 cases of primary TKA during 2010 from a single institution with two different groups of patients, allocating cases to the group with MBLPA (group 1, study group, N = 71) and controls to the group without MBLPA (group 2, standard group, N = 347). MBLPA procedure included pre-operative haemoglobin (Hb) optimisation; femoral canal obturation; limited incision and release; peri- and intra-articular use of saline with adrenalin, morpheic chloride, tobramycin, betamethasone and ropivacaine; tourniquet release after skin closure; 24 hour drain under atmospheric pressure; and two doses of tranexamic acid (TXA) IV. In the control group, surgeons followed the standard procedure without blood-saving techniques. Case–control comparison and blood transfusion risk factors were analysed.

Results

Group 1 had a zero transfusion rate (0/71), whereas 27.4 % of patients (95/347) in group 2 received allogenic blood transfusion. Significant transfusion risk factors were pre-operative Hb <12 g/dl), American Society of Anesthesiologists (ASA) status III and nonobese body mass index (BMI); Age and gender were not significant risk factors.

Conclusions

MBLPA in primary TKA was highly effective, with a zero transfusion rate. Risk factors for transfusion were determined, and eliminating them contributed to the avoidance of allogeneic blood transfusion in our study series.     

Pre-operative arthritis severity as a predictor for total knee arthroplasty patients’ satisfaction

Purpose

Studies have shown that up to 25 % of TKA patients are dissatisfied with the implanted knee, even if registry data shows ten-year revision rates below 5 %. It has been the question of our study, if it would be possible to identify those patients at risk for dissatisfaction pre-operatively.

Methods

The data of 1,121 consecutive TKA patients with a follow-up between one and six years have been analysed retrospectively. Demographic, radiologic and perioperative variables have been recorded and all patients were asked by questionnaire for satisfaction with the implanted knee. Logistic regression models have been used to identify significant risk factors.

Results

The data of 996 patients (89 %) were complete, 849 (85.2 %) reported satisfaction and 147 (14.8 %) dissatisfaction. Patients’ satisfaction was independent of the time after operation (p = 0.285). The only factor which influenced patients’ satisfaction was the osteoarthritic severity. In comparison to severe arthritis Kellgren Lawrence IV°, the risk for dissatisfaction was 2.556-fold elevated for arthritis grade III° (p < 0.001) and 2.956-fold higher for grade II° (p = 0.001).

Conclusions

Patients suffering from mild or moderate osteoarthritis are at risk for dissatisfaction after TKA. The TKA indication in those patients should therefore be critically proven. Furthermore, to adjust patients’ expectations, the elevated dissatisfaction risk in case of mild or moderate osteoarthritis should be included into patients’ pre-operative information.     

Intra-articular injection of tranexamic acid reduces not only blood loss but also knee joint swelling after total knee arthroplasty

Purpose

This is a randomised controlled trial to examine whether intra-articular injection of tranexamic acid (TXA) decreases blood loss, as well as reducing leg swelling after total knee arthroplasty (TKA).

Methods

We performed 100 TKA in osteoarthritis patients. At closure, a total of 2,000 mg/20 ml TXA was injected into the knee joint through a closed suction drain (TXA group). For the control group, the same volume of physiological saline was injected. The pre-operative condition of the patients, post-operative haemoglobin (Hb) levels, discharge volumes from drain, D-dimer and needs for transfusion were compared between these two groups. Furthermore, leg diameters (thigh, suprapatellar portion and calf girth) were measured pre- and post-operatively to investigate whether TXA has an influence on leg swelling after surgery.

Results

The results revealed that post-operative decrease in Hb level was significantly reduced in the TXA group. Furthermore, knee joint swelling after operation was significantly suppressed in the TXA group compared to the control group.

Conclusions

The results revealed intra-articular administration of TXA decreased not only blood loss, but also knee joint swelling after TKA.     

Combining different rotational alignment axes with navigation may reduce the need for lateral retinacular release in total knee arthroplasty

Purpose

The aim of the study was to compare femoropatellar alignment and the incidence of lateral retinacular release (LRR) in total knee arthroplasty (TKA) in which the rotational alignment of the femoral component was determined using a combination of different rotational alignment axes and navigation or a single reference axis in the standard procedure.

Methods

We assessed 66 patients undergoing TKA in whom the rotation of the femoral component was determined on the posterior condylar axis in standard procedures (group A) and 65 patients in whom it was determined by combining the posterior condylar axis, anteroposterior axis and epicondylar axis in navigated procedures (group B). The mean age was 68 and 69 years in groups A and B, respectively. Patellar tracking was assessed after deflation of the tourniquet and LRR performed in the presence of maltracking. Visual analogue scale (VAS), Knee Society Score (KSS), Lonner patellar score and patellar tilt were recorded.

Results

LRR was carried out in 18 cases (27 %) in group A and in four (6 %) in group B (p = 0.003). The KSS and VAS were improved significantly compared to the preoperative status, but with no significant differences between the two groups. The patellar score showed a greater improvement in the navigated compared to the standard group at the four week follow-up. Patella tilt improved significantly in both groups. The complication rate was similar in the two groups.

Conclusions

Combining different rotational alignment axes with navigation significantly reduces patellar maltracking and the need for LRR compared to the standard procedure in which the posterior condylar axis is used as single anatomical reference.     

Total knee arthroplasty at 15–17 years: Does implant design affect outcome?

Purpose

A study was conducted to compare minimum 15-year survivorship and outcome of the Genesis I and II implants for total knee arthroplasty (TKA).

Methods

We retrospectively reviewed 245 consecutive TKA implanted between January 1995 and October 1997. Genesis I was implanted in 156 knees and Genesis II in 89 knees.

Results

At 15–17 years, 75 patients (31 %) had died, 28 patients (11 %) were lost to follow-up and 11 TKA were revised (4.6 %), including ten Genesis I (6.4 %) and one Genesis II (1.1 %); 131 TKA (53 %) were available for follow-up. Cumulative survivorship was 92.4 % at 15.7 years. Survival in patients <69 years at surgery was lower (88.0 %) compared with patients ≥69 years (98.5 %; p = 0.023). In patients <69 years, Genesis I survival (84.3 %) was worse compared with Genesis II (97.1 %) (p = 0.018). Polyethylene (PE) Insert thickness ≤11 mm had significantly better survivorship (97.1 %) compared with PE >11 mm (56.7 %) (p < 0.0001)

Conclusions

At a minimum of 15 years, the overall (92.4 %) survivorship of Genesis TKA was good, with excellent (98.1 %) survivorship of the Genesis II design. Revision rates were higher with Genesis I in the younger age group and with insert thickness >11 mm, possibly due to longer shelf life of less frequently used sizes.     

Platelet-rich plasma prevents blood loss and pain and enhances early functional outcome after total knee arthroplasty: a prospective randomised controlled study

Purpose

The purpose of this study was to determine whether platelet-rich plasma (PRP) might prevent blood loss and postoperative pain and expedite wound healing following total knee arthroplasty (TKA).

Methods

Forty consecutive patients with knee arthritis who were matched for age, sex and body mass index (BMI) were randomly allocated to either receive or not receive PRP application over the wound, including capsule, medial and lateral recesses, during TKA. Postoperative haemoglobin, blood loss, blood transfusion, visual analogue scale (VAS) score, wound score, Knee Society Score (KSS) and Western Ontario and McMaster Osteoarthritis Index (WOMAC) score were recorded and evaluated.

Results

The platelet-rich plasma and control groups comprised 17 and 23 patients, respectively. The PRP group recorded significantly less reduction in haemoglobin and need for blood transfusion (p = 0.00 and p = 0.001, respectively), experienced less pain (p = 0.00) and required fewer narcotics than the control (p = 0.00). There was significant difference in range of motion (ROM) at three months (p = 0.01), no significant difference in wound scores (p = 0.311) and significant difference in KSS and WOMAC scores at 12 weeks (p = 0.00, 0.00). However no significant difference was found at six months.

Conclusions

PRP has significant effect in preventing blood loss, postoperative pain and need for narcotics after TKA and has a positive effect on short-term clinical outcome.     

Functional outcomes comparing Triathlon versus Duracon total knee arthroplasty: does the Triathlon outperform its predecessor?

Purpose

Total knee arthroplasty (TKA) prosthesis designs are constantly evolving to obtain greater functional performance. The aim of this study is to compare the functional outcomes between the newer single radius (SR) Triathlon prosthesis with its multiradius (MR) predecessor the Duracon.

Method

We analysed 1,012 primary TKA procedures which used either the Triathlon SR prosthesis or the Duracon MR prosthesis (338 Triathlon, 674 Duracon). Patients were assessed using the Knee Society score (KSS), range of movement measurements, pain and walking assessments at time points pre-operatively, one year and two years postoperatively.

Results

Both groups were similar pre-operatively in terms of age, gender and body mass index (BMI). At one year postoperatively the Triathlon group had a significantly better flexion (P = 0.005) and KSS (function score P = 0.037, knee score P = 0.000). At two years postoperatively the Triathlons had maintained a significantly better KSS (function score P = 0.046, knee score P = 0.000) and also knee flexion (P = 0.02). Pain assessments at two years were significantly better in the Triathlon group (P = 0.002) with 66.3 % of patients experiencing no pain at that point compared to 54.4 % with Duracon knees.

Conclusion

This data supports the proposition that the use of Triathlon TKA results in improved outcomes for patients when compared to the Duracon TKA.     

Impact of the tibial slope on range of motion after low-contact-stress,mobile-bearing,total knee arthroplasty

Purpose

The aim of this study was to analyse a possible correlation between the tibial slope and range of motion (ROM) after implantation of the low-contact-stress (LCS), mobile-bearing, total knee arthroplasty (TKA) after a minimum follow-up of ten years.

Methods

Eighty-three TKAs in 66 patients were investigated in this retrospective correlation analysis at a minimum follow up of ten years. Out of these 66 patients, 50 were women (76 %) and 16 (24 %) were men. The average age of these patients at the time of the examination was 76 years [standard deviation (SD) 11 years, range 37–95 years]. A lateral X-ray was taken at follow-up in order to analyse the tibial slope with respect to inter- and intra-observer agreement. ROM was measured and correlated with the tibial slope.

Results

The mean active ROM was 96.1° (SD 18.8) and the mean tibial slope after four measurements was 7.65° (SD 4.23), with substantial inter- and intra-observer agreement. We found no significant correlation between tibial slope and ROM in patients with a minimum follow-up of ten years [correlation 0.196 (p > 0.05) and 0.152, (p > 0.05), respectively].

Conclusions

Alteration of the tibial slope does not significantly influence ROM after implantation of the LCS TKA at a minimum follow-up of ten years. We conclude that the tibial slope is not the primary influencing factor for ROM in patients ten years after primary TKA and believe that it should not substantially be altered during surgery.     

How often is functional range of motion obtained by manipulation for stiff total knee arthroplasty?

Purpose

To evaluate how often manipulation under anesthesia (MUA) can achieve functional flexion ≥ 90 degrees and identify predictor for successful outcome of MUA for stiff total knee arthroplasty (TKA).

Methods

Demographic data, range of motion, and surgical and anesthetic information of 143 MUAs were retrospectively analyzed from 2000 to 2011.

Results

One-hundred thirty-six out of 143 patients (95 %) improved mean range of motion (ROM) from pre-MUA 62 ± 17° to final ROM 101 ± 21° (p < 0.001). Flexion ≥ 90 degrees was achieved in 74% (106/143) of patients. Regional anesthesia was identified as predictor of successful MUA outcome (p = 0.007, OR: 8.5, 95 % CI: 1.2-66.7).

Conclusions

Although the proportion of patients regaining flexion ≥ 90 degrees following MUA was less than those patients with simple overall ROM increase, the functional flexion ≥ 90 degrees was achieved in the vast majority of patients with stiff TKA following MUA.     

Relationship between patient-based outcome score and conventional objective outcome scales in post-operative total knee arthroplasty patients

Purpose

Evaluations for knee osteoarthritis (OA) or post-operative total knee arthroplasty (TKA) have mainly been assessed by objective scales. Though the Knee injury and Osteoarthritis Outcome Score (KOOS) is attracting attention as a patient-based outcome score, the relationship with conventional objective scales after TKA remains controversial. The purpose of this study was to investigate the relationship between KOOS and conventional objective scales and evaluate the features of patient-based outcome scores.

Methods

Subjects were 130 post-operative patients involving 186 knees treated with TKA. Their mean age was 74.0 ± 8.0 years, and the follow-up period was 43 months. Japanese Orthopaedic Association (JOA) score, original Knee Society Score (KSS) and surgeon’s satisfaction score were scored as conventional objective scales besides KOOS. Spearman’s correlation coefficient was estimated between these scales. Comparisons between OA and rheumatoid arthritis (RA) as well as primary and revision surgery were performed by the Mann–Whitney U test.

Results

There were strong correlations between KOOS activities of daily living (ADL) and JOA score (r = 0.806), KSS function score (r = 0.803) and between KOOS pain and KSS knee score (r = 0.689). However, there was a poor correlation between KOOS and surgeon’s satisfaction score (r = 0.188-0.321). TKA for RA showed poorer results only in KOOS pain (p = 0.003), and revision surgery showed poorer results in KSS function, KOOS symptoms and KOOS quality of life (QOL).

Conclusions

This study suggested that conventional objective scales reflected mainly ADL disturbances in post-operative TKA patients. Furthermore, patient-based outcome scores made it possible to evaluate and detect a minute change of knee pain and QOL in TKA patients. The Japanese KOOS was a useful tool to evaluate conditions after TKA.     

Influence of computer navigation on TKA revision rates

Purpose

We performed this study to determine whether the use of imageless navigation reduces revision rates after total knee arthroplasty (TKA).

Methods

Data of 1,121 consecutive primary TKA with a follow-up of one to six years were retrospectively analysed. Following the conversion of the standard technique from conventional to navigated procedures, these data included the last 342 conventional and first 779 navigated procedures performed in our clinic. Demographic and perioperative covariates were recorded. All patients were asked by post to report instances of revisions.

Results

Data of 1,054 patients (94 %) were complete. Mean follow-up was 3.9 years for conventional and 2.4 years for navigated operations. Cumulative revision rate averaged 4.7 % for conventional and 2.3 % for navigated procedures. Cox’s proportional hazard model was used to assess the effect of covariates on survival, resulting in significantly lower revision rates for older patients (p < 0.001) and for the navigated technique (p = 0.012). The reduced revision rate for navigated operations was mainly caused by a significantly reduced rate of aseptic implant loosening (1.9 % vs. 0.1 %, p = 0.024).

Conclusions

Our study showed lower revision rates when computer navigation was used. However, due to the retrospective uncontrolled design, further prospective trials will be necessary to further evaluate this effect.     

The Use of Biologic DMARDS Identifies Rheumatoid Arthritis Patients with More Optimistic Expectations of Total Knee Arthroplasty

Background

Preoperative expectations of total knee arthroplasty (TKA) correlate with postsurgical satisfaction, and are linked to outcomes. Rheumatoid arthritis (RA), and other chronic diseases, may lower expectations, although new biologic medications have greatly enhanced patients’ quality of life.

Questions/Purposes

The purpose of this study is to compare preoperative expectations of RA to those of matched osteoarthritis (OA) patients undergoing TKA, and examine the subset of RA on biologic DMARD therapy.

Methods

For a cross-sectional study, RA and OA identified from an institutional TKA registry were matched on age, sex, prior TKA, and preoperative function. Expectations were measured using the Hospital for Special Surgery (HSS) Knee Expectations Survey. Expectations and quality of life measures were assessed preoperatively and scores were compared between RA and OA.

Results

One hundred fourteen RA cases, 46.5% on biologics, were matched to 228 OA cases. The average expectations score was not significantly lower for RA compared to OA (72.9 ± 20.7 vs. 77.2 ± 18.3, p = 0.040. RA on biologics had expectations similar to OA (total expectation score 76.3 ± 18.1 vs. 77.4 ± 17.4, p = 0.71), while RA not on biologics had expectations that were significantly lower (69.9 ± 22.4 vs. 77.1 ± 19.0, p = 0.03).

Conclusion

Use of biologics in RA patients was associated with higher expectations, similar to those of OA patients, but the effect on outcomes is not known. Further studies should assess the effect of higher expectations in RA patients on outcomes.

Electronic supplementary material

The online version of this article (doi:10.1007/s11420-014-9380-1) contains supplementary material, which is available to authorized users.     

Total knee arthroplasty after high tibial osteotomy: a comparison of opening and closing wedge osteotomy

Purpose

High tibial osteotomy (HTO) is frequently used to treat varus osteoarthritis in younger patients with the goal of delaying the need for total knee arthroplasty (TKA). While it has been reported that the results of TKA following HTO are worse than those in patients without prior knee surgery, the influence of osteotomy technique (medial opening-wedge versus lateral closing-wedge) has not been explored. The purpose of this study was to evaluate the influence of HTO technique on the performance and results of TKA.

Methods

A total of 141 TKA’s performed in 118 patients with prior HTO (24 opening wedge and 117 closing wedge) were reviewed at a mean follow-up of two years. Reviewed data included intra-operative factors (tourniquet time, the need for additional exposure, and intra-operative complications), clinical results (International Knee Score (IKS)) and radiographic assessment of limb alignment.

Results

The average IKS knee and function scores improved from 54.0 and 60.3 to 87.0 and 79.5 (p <  0.0001). There was no significant difference in IKS scores based on osteotomy technique. There was a trend toward an increased need for tibial tubercle osteotomy in the closing wedge group. There was an increased need for extensive medial release in the opening wedge group and extensive lateral release in the closing wedge group. No differences in tourniquet time, complication rates, or hip-knee-ankle angle were noted between the two groups.

Conclusions

Radiographic limb alignment, patient-reported outcomes, and complication rates are equal in patients undergoing TKA after opening and closing wedge HTO.     

Evaluation of patellofemoral joint in ADVANCE® Medial-pivot total knee arthroplasty

Purpose

ADVANCE® Medial Pivot (MP) (Wright Medical) total knee arthroplasty (TKA) was established to replicate normal tibio-femoral knee joint kinematics, however, its influence on the patello-femoral (PF) joint is unclear. The purpose in this study was to assess the PF joint conditions in Advance MP TKA, via radiography and three-dimensional image-matching software.

Methods

Ten subjects with osteoarthritis were treated with the ADVANCE MP TKA. Pre-operatively and one month after surgery, skyline views at 30, 60, and 90° of flexion were taken, and patella shift and tilt were measured. With 2D–3D registration techniques using software, implant orientations were matched with the pre-operative CT and changes in the anterior part of the femoral prosthesis, condylar twist angle (CTA) for femoral rotation, and tibial rotation were evaluated. The relationships between morphological and rotational changes were evaluated.

Results

There were significant differences in patella tilt at 60° and patella shift at all angles between pre- and post-operation (p < 0.05). No correlation was found between morphological changes in the anterior femur with patella tilt and shift. A positive correlation between postoperative CTA and patella shift at 90° was found (p < 0.05); however, no correlation was found between rotational alignment of the tibial component and patella tilt and shift.

Conclusions

ADVANCE MP TKA changed patello-femoral joint kinematics, compared to that found before surgery. The kinematic features were mainly due to the design concepts for tibio-femoral joint motion, indicating the difficulty to reproduce normal patello-femoral joint kinematics after TKA.     

The natural history of a newly developed flexion contracture following primary total knee arthroplasty

Purpose

We investigated the incidence, natural history, and functional consequences of a newly developed flexion contracture after total knee arthroplasty (TKA).

Methods

Forty patients with full knee extension preoperatively who developed a postoperative flexion contracture were match-paired 1:2 with 80 patients who had full extension. The incidence of a newly developed flexion contracture, ROM, and Knee Society scores (KSS) at six weeks, four months, and one year were analysed.

Results

The incidence of a new flexion contracture at six weeks was 14 %, but diminished to 5 % and 0.3 % at four months and one year, respectively. One year after surgery, there was no difference in the KSS (p = 0.5).

Conclusions

This study showed that the majority of patients who developed a new flexion contracture after TKA have full knee extension one year postoperatively. Moreover, knee extension and KSS at one year are equivalent to those patients who did not developed a flexion contracture.     

The influence of patella height on soft tissue balance in cruciate-retaining and posterior-stabilised total knee arthroplasty

Purpose

Although the patella reduced or everted position has recently been recognised as an important factor influencing soft tissue balance during assessment in total knee arthroplasty (TKA), the influence of patella height on soft tissue balance has not been well addressed. Therefore, the relationship between soft tissue balance and patella height was investigated and differences between cruciate-retaining (CR) and posterior-stabilised (PS) TKA were compared.

Methods

Forty consecutive patients blinded to the type of implant received, were randomised prospectively. Using lateral radiographs, pre-operative patella height was measured. Using an offset-type tensor designed to measure the soft tissue balance with a reduced patellofemoral (PF) joint and femoral component in place, soft tissue balance was intra-operatively assessed in CR TKA (n = 20) and PS TKA (n = 20) in osteoarthritic patients. The joint component gap and varus ligament balance at zero, ten, 45, 90 and 135° of knee flexion with the patella reduced were measured.

Results

In PS TKA, the joint component gap positively correlated with patella height at 90 and 135° of knee flexion. However, there was no correlation between joint component gap and patella height at other flexion angles in PS TKA and any flexion angle in CR TKA. Varus ligament balance showed no significant correlation with patella height in either CR or PS TKA.

Conclusion

Analysis of soft tissue balance and patella height only showed a positive correlation in joint component gap at a high flexion angle (90 and 135°) in PS TKA but not in other parameters examined. Pre-operative measurement of patella height may be an important factor for predicting an intra-operative flexion gap in PS TKA.     

Results of a French multicentre retrospective experience with four hundred and eighteen failed unicondylar knee arthroplasties

Purpose

By means of a multicentre retrospective study based on the failure of 418 aseptic unicondylar knee arthroplasties (UKA) our aims were to present the different types of revision procedure used in failed UKAs, to establish a clear operative strategy for each type of revision and to better define the indications for each type of revision.

Methods

Aseptic loosening was the principal cause of failure (n = 184, 44 %) of which 99 cases were isolated tibial loosening (23.5 % of the whole series and 54 % of all loosening), 25 were isolated femoral loosening (six and 13.6 %) and 60 were both femoral and tibial loosening (14.3 and 32.6 %). The next most common causes of failure were progression of arthritis (n = 56, 13.4 %), polyethylene wear (n = 53, 12.7 %), implant positioning errors (n = 26), technical difficulties (n = six) and implant failure (n = 16, 3.8 % of cases). Data collection was performed online using OrthoWave™ software (Aria, Bruay Labuissiere, France), which allows collection of all details of the primary and revision surgery to be recorded.

Results

A total of 426 revisions were performed; 371 patients underwent revision to a total knee arthroplasty (TKA) (87 %), 33 patients (7.7 %) were revised to an ipsilateral UKA, 11 (2.6 %) patients underwent contralateral UKA (ten) or patellofemoral arthroplasty (one) and 11 patients (2.6 %) underwent revision without any change in implants.

Conclusions

Before considering a revision procedure it is important to establish a definite cause of failure in order to select the most appropriate revision strategy. Revision to a TKA is by far the most common strategy for revision of failed UKA but by no means the only available option. Partial revisions either to an alternative ipsilateral UKA or contralateral UKA are viable less invasive techniques, which in carefully selected patients and in experienced hands warrant consideration.     

The benefit of revision knee arthroplasty for component malrotation after primary total knee replacement

Purpose

Revision surgery for component malrotation in the painful TKA is a relatively novel indication. The purpose of this study was to assess the benefit of revision TKA for component malrotation with regard to the clinical and functional outcomes.

Methods

Our retrospective case–control study included 51 patients who underwent revision surgery for malrotation with mean follow up of 42 months. They were equally matched to patients who had surgery for aseptic loosening.

Results

Knee society scores improved from 44/49 to 75/60 (p < 0.001) for the study group and 44/47 to 76/57 (p < 0.001) for the control group. There was no statistical difference between the groups, including for VAS scores, narcotic reduction or patient satisfaction. Our study showed that revision surgery for malrotation is as beneficial as surgery for aseptic loosening with regard to clinical and functional outcome.

Conclusions

We recommend CT in painful TKA to assess component malrotation for which revision TKA is beneficial.     

Rotational laxity and collateral ligament laxity following total knee arthroplasty with rotating platform

Purpose

The aim of this study was to evaluate laxity in knees with pre-operative (preop) valgus alignment compared to knees with pre-operative varus alignment after total knee arthroplasty (TKA).

Methods

This was a retrospective study including 81 patients, with six years follow-up, for pre-operative valgus- or varus alignment of the leg. All patients had been supplied with the same cruciate retaining (CR) TKA with rotating platform. Clinical findings were assessed by KSS, OKS and IKDC 2000 score. Rotational knee laxity was evaluated by a validated instrument (Laxitester®) with 2 Nm torque in 30° flexion. Collateral ligament laxity was tested manually in 30° flexion with a bending moment of approximately 5 Nm. Biomechanical results were compared to the contralateral side.

Results

Thirty-one patients had a preop valgus alignment of 8.96° and 50 patients a varus leg axis of 4.99° in the mean. In the preop valgus knees rotational analysis showed an increased laxity of 10.7° compared to preop varus knees (p = 0.001). There was no significant difference in medial (valgus 2.6 mm, varus 2.5 mm) and lateral (valgus 2.8 mm, varus 2.7 mm) laxity. KSS and OKS showed no significant differences in the follow-up results. In the IKDC 2000 objective score 50 % of the preop varus knees and 25.8 % of the preop valgus knees were classified as nearly normal. The difference in the IKDC objective was highly significant (p < 0.001).

Conclusion

Preop valgus knees show a significantly increased rotational laxity but no increased collateral ligament laxity compared to pre-operative varus knees six years after TKA with rotating platform. There is a significant difference in IKDC objective.     

Is tranexamic acid effective and safe in spinal surgery? A meta-analysis of randomized controlled trials

Purpose

The present meta-analysis aimed at assessing the effectiveness and safety of tranexamic acid (TXA) in reducing blood loss and transfusion in spinal surgery.

Methods

Systematic searches of all studies published through March 2012 were identified from PubMed, EMBase, Cochrane library, Science Direct, and other databases. Only randomized controlled trials (RCTs) were included in the present study. Two independent reviewers searched and assessed the literature. Mean difference (MD) of blood loss and blood transfusions, risk ratios (RR) of transfusion rate and of deep vein thrombosis rate in the TXA-treated group versus placebo group were pooled throughout the study. The meta-analysis was conducted by RevMan 5.1 software.

Results

Six placebo-controlled RCTs encompassing 411 patients met the inclusion criteria for our meta-analysis. The use of TXA significantly reduced both total blood loss [MD = −285.35, 95 % CI (−507.03 to −63.67), P = 0.01] as well as the number of patients requiring blood transfusion [RR = 0.71, 95 % CI (0.54–0.92), P = 0.01]. None of the patients in the treatment group had deep-vein thrombosis (DVT) or pulmonary embolism.

Conclusions

Intravenous use of TXA for patients undergoing spinal surgery is effective and safe. It reduces total blood loss and the need for blood transfusion, particularly in the using of high dosage of TXA (≥15 mg/kg), yet does not increase the risk of postoperative DVT. Due to the limitation of the quality of the evidence currently available, high-quality RCTs are required.