Search

Purpose: Donor site morbidity is the main drawback to using bone-patellar tendon-bone (BPTB) as a graft in anterior cruciate ligament (ACL) reconstruction. The objective of the study was to determine whether refilling the patellar bone defect after BPTB harvesting with autograft bone decreased kneeling pain to a greater degree when compared with a group in which bone defect is left unaddressed., Methods: This is a randomised single-blinded controlled study. Forty patients were randomised into two groups; group 1: Patellar bone defect filled with autologous bone; group 2: Bone defect left undressed. Pain was measured by means of pressure algometry (PA). Functional outcomes were measured with the Kujala and Victorian Institute of Sport Assessment-Patella (VISA-P) score. Magnetic resonance imaging (MRI) was done to measure bone buildup between groups at the 1-year follow-up., Results: No differences were observed in the different algometry measurements and the scores were assessed at 3, 6 and 12 months postoperatively. The ratio of void filled remained consistently higher (p = 0.003) in group 1 when compared to group 2., Conclusions: Although refilling the lower pole of the patella with autologous bone from the harvested BPTB autograft loads the bone defect, it does not reduce pain at the donor site 1 year after surgery., Level of Evidence: Therapeutic study level 1., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Introduction: One of the main concerns around the use of antibiotic-loaded bone cement (ALBC) is the potential reduction in the mechanical properties of the cement when antibiotics are admixed. The purpose of this study was to determine whether there is a difference between plain cement and ALBC in terms of radiological intrusion into the bone in total knee arthroplasties (TKAs)., Methods: Prospective randomized study of 80 consecutive patients who underwent TKA. Depending on the cement used, patients were divided into two groups by a computer-generated randomization programme: the cement without antibiotic (Group 1) or the ALBC (Group 2). Cement intrusion was measured in postoperative radiographs in eight different regions in the tibial component and six regions in the femoral component., Results: The average cement intrusion was similar in both groups (p = nonsignificance [n.s.]). Group 1 (plain cement) had an average cement intrusion in the femur of 1.4 mm (±0.4) and 2.4 mm (±0.4) in the tibia. In Group 2 (ALBC), the average cement intrusion in the femur came to 1.6 (±0.5) and 2.4 mm (±0.5) in the tibia. In 80% of the patients, the cement intrusion in the tibia averaged a minimum of 2 mm, being similar in both groups (p = n.s.)., Conclusion: There are no differences in bone intrusion when comparing plain cement to ALBC. Therefore, the use of ALBC in primary TKA may be indicated, achieving optimal bone penetration., Level of Evidence: Level I., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Purpose: The aim of this study was to assess the effect of systematic lateral retinacular release (LRR) on anterior knee pain (AKP), as well as its impact on the functional and radiological outcomes after total knee arthroplasty (TKA) with patellar resurfacing., Methods: A prospective randomized study was designed. It included patients scheduled for a TKA procedure with patellar resurfacing, who were recruited and randomized into either the LRR group or the non-release group. 198 patients were included in the final analysis. The pressure pain threshold (PPT) assessed by pressure algometry (PA), the visual analogue scale (VAS), Feller's patellar score, the Knee Society Score (KSS), patellar height, and patellar tilt were recorded both preoperatively and at the 1-year follow-up. The Mann-Whitney U test was performed to determine comparisons between both groups as well as to determine differences' intragroup., Results: Relative to the clinical variables and scores, no difference was detected between the two groups at the 1-year follow-up (p = n.s.). However, there was a slight difference in patellar tilt (0.1º vs. 1.4º, p = 0.044), with higher tilt values in the non-release group. There was no difference in terms of improvement in the clinical and radiological scores and variables recorded between the two groups (p = n.s.)., Conclusion: LRR in primary TKA with patellar resurfacing does not show an improvement in AKP and functional outcomes over patellar resurfacing without release., Level of Evidence: I., (© 2023. The Author(s) under exclusive licence to European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The aim of this study was to compare the posterior tibial translation after ultracongruent (UC) and posterior-stabilized (PS) total knee arthroplasty (TKA) with two different UC with different heights in the anterior lip, and two different PS designs. This study also aimed to compare the range of motion (ROM) and outcomes scores after the use of these TKA models. It was hypothesised less posterior tibial translation after PS than after UC TKA, and less posterior tibial translation with a higher anterior lip in the UC insert than with a lower one., Methods: It was designed as a prospective randomized study of a group of 120 patients operated with a cemented TKA. To clarify the main purpose of the study, four groups were analysed using different polyethylene designs: Triathlon PS insert in group one, Triathlon UC insert in group two, U2 PS insert in group three and U2 UC insert in group four. One year after surgery, a forced posterior drawer with a Telos Stress applying 15 kg of force posteriorly on the proximal tibia at 90° of knee flexion was analysed in the lateral radiograph. Limb alignment, tibial posterior slope and posterior condylar offset were also studied., Results: 30 patients were included in each group. The average age was 73 years. There were 72.2% female and 27.8% male patients. There were no significant differences in any demographic or radiographic studied variables, preoperative range of motion (ROM) or preoperative Knee Society Scores (KSS) among the different groups. One year after surgery, the average postoperative ROM and the postoperative KSS Knee and KSS Function scores improved in respect of the preoperative values in all the groups. There were no significant differences in the postoperative outcome scores among the different groups (p = n.s.). Postoperative alignment of the limb, tibial posterior slope and posterior condylar offset were similar in the 4 study groups (p = n.s.). The postoperative posterior tibial translation was different between groups: the PS groups (groups 1 and 3) showed significant inferior values (p < 0.001) in respect of the UC groups (groups 2 and 4). There were no differences between both groups of PS models, but there was a significant increase in the posterior tibial translation of the Triathlon UC insert (11.2 mm SD 3.2) in respect of the U2 UC insert (6.1 mm SD 4.5) (p = 0.004)., Conclusions: UC inserts restrict the posterior tibial translation after TKA less than PS inserts, but a design with a high anterior lip in the polyethylene UC insert can better control the posterior tibial translation than an insert with a small anterior lip., Level of Evidence: Level I. Randomised controlled trial., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The aim of this study was to compare the correlation between preoperative quadriceps femoris muscle thickness and postoperative neuromuscular activation and quadriceps femoris strength in patients with and without patellofemoral pain after arthroscopic partial meniscectomy., Methods: A series of 120 patients were prospectively analysed in a longitudinal cohort study of patients scheduled for arthroscopic partial meniscectomy. The patellofemoral pain group included patients who developed anterior knee pain after surgery while the control group included those who had not done so. Patients with preoperative patellofemoral pain, previous knee surgeries as well as those on whom additional surgical procedures had been performed were excluded. Of the 120 initially included in the study, 90 patients were analysed after the exclusions., Results: There is a direct correlation between preoperative quadriceps femoris muscle thickness and the neuromuscular activity values and the strength of the muscle at 6 weeks after surgery. These results were seen exclusively in the group of patients who do not develop patellofemoral pain (0.543, p = 0.008). The group of patients who developed anterior knee pain in the postoperative period did not show this correlation (n.s.)., Conclusion: In patients without patellofemoral pain after meniscectomy, the greater the preoperative thickness of the quadriceps femoris, the more postoperative neuromuscular activation and strength they had. This correlation did not occur in those patients who develop patellofemoral pain after meniscal surgery., Level of Evidence: II., (© 2021. The Author(s).)

Purpose: The aim of the study was to compare the distance of intrusion of the cement into the bone in different areas both in the femur and the tibia in vivo, measured in the radiograph after implanting a total knee arthroplasty (TKA) with three different cement techniques., Methods: A prospective randomized study of 90 consecutive patients operated on at our institution with a cemented U2 Knee System TKA and medium viscosity Simplex P ® bone cement. After pulse lavage, the cement was applied on the bone surfaces (group 1), on the implant surfaces (group 2) or both on the bone and the implant surfaces (group 3). The cement intrusion was measured in the postoperative radiographs in eight different regions in the tibial component and in six regions in the femoral component. The cement employed was calculated by weighting the cement after mixing and weighting the discarded cement., Results: The average intrusion of the cement was similar in all three groups of cementing techniques in the femoral components (1.6 mm; p = 0.386), and in the tibial components (2.6 mm; p = 0.144). The intrusion of the cement in the tibia was greater in women than in men (p = 0.04). We used 21.1 (SD 5.8) g of cement in average. The amount of cement employed was greater when the cement was applied on both (implant and bone) surfaces (group 3: 24.03 g in average) than when it was applied only on the bone (group 1: 20.13 g; p = 0.01) or only on the implants (group 2: 19.20 g; p = 0.001). The amount of cement employed was greater in men than in women (p = 0.002) and it was also greater when a PS femoral component was used (p = 0.03). The amount of cement employed was directly correlated with the height of the patients (p = 0.01) and with the bigger size of the components (p < 0.001)., Conclusion: All three cement application techniques have similar intrusion distance of the cement into the bone, and the intrusion depth of the cement into the trabecular tibial bone is greater than the minimum suggested for fixation., (© 2021. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: Anterior knee pain (AKP) is a frequent symptom after a total knee arthroplasty (TKA). Patellar denervation (PD) has been put forth as a technique to reduce this pain; however, its effects have not been assessed in combination with patellar resurfacing. The aim of this study is to evaluate the effect of PD on AKP and functional outcomes after TKA with patellar resurfacing., Methods: A prospective study was designed that included patients scheduled for TKA with patellar resurfacing. The 202 recruited patients were randomized into either the PD group or the non-denervation group [mean age 72.7 years (SD 8.2); 119 (70.4%) women and 50 (29.6%) men; average body mass index 31.4 kg/m 2 (SD 4.9)]. Pressure pain threshold (PPT) assessed by pressure algometry (PA), visual analogue scale(VAS), patellofemoral Feller score and the Knee Society Scores (KSS) were recorded preoperatively and at the 1-year follow-up., Results: 169 patients were included in data analysis. At the 1-year follow-up, there were mild differences between denervation and non-denervation group in PPT value (494.4 kPa vs. 552.3 kPa, p = 0.047) and in VAS at stairs (2.9 vs. 1.5, p = 0.003) in favour of the non-denervation group. There was no difference in the improvement between groups in patellofemoral Feller score and KSS, but slightly higher improvement in non-denervation group in PPT (94.1 kPa vs. 160 kPa, p = 0.047), VAS walking (5.3 vs. 6.2, p = 0.041) and VAS at stairs (4.6 vs. 5.7, p = 0.022)., Conclusion: Patellar denervation does not improve AKP and clinical outcomes in primary TKA with patellar resurfacing compared to patellar replacement without denervation. PD cannot be recommended when patellar replacement is performed in TKA., Level of Evidence: II., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The aim of the study was to translate and validate the English version of the 'Knee Society Knee Scoring System' developed in 2011 (2011 KSS) into Spanish. This new KSS version considers patient satisfaction and expectations before and after knee arthroplasty. Moreover, the questionnaire allows a better characterization of a younger and more diverse population., Methods: A cross-cultural adaptation process was carried out to obtain the Spanish version of the questionnaire. After that, patients undergoing primary knee arthroplasty answered the translated questionnaire before and 6 months after surgery. Psychometric properties including feasibility, validity, reliability, and sensitivity to change were then assessed, and the questionnaire was compared with prior KSS, as well as with SF-12 and WOMAC, all of them already validated to Spanish., Results: In the cross-cultural adaptation process, alternative translations of some items in 'Patient Expectative' and 'Functional Activities' sections were suggested. One hundred and seventy-six patients answered the resulting 1.0 version. Feasibility: 'Charnley Functional Classification', 'Deduction for flexion contracture and extensor lag', the question 'Do you use these aids because of your knees?', and 'Advanced activities (total)' obtained a high number of missing items. Eighty-eight patients (50%) in the preoperative visit and 141 patients (86.5%) after surgery had at least one missing answer. Internal validity: although the analysis suggests the presence of more than one dimension, there was a dimension that explained a higher percentage of variance, which was more noticeable in the postoperative visit. Convergent validity: correlation coefficients with prior KSS, SF-12, and WOMAC confirm the questionnaire's validity. Reliability: Cronbach's alpha for the new KSS was 0.841 and 0.861 in visit 1 and 2, respectively, and higher than that for prior KSS. Sensitivity to change: statistically, significant differences were found between the mean scores between both visits., Conclusion: The proposed Spanish version of 2011 KSS is valid, reliable, and sensible to change in patients undergoing primary knee arthroplasty. Moreover, it has higher internal consistency (reliability) than the prior KSS. It should be emphasized its correct filling by both health professional and patients LEVEL OF EVIDENCE: II., (© 2020. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA).)

Purpose: The presence of allergies has been proposed as a risk factor for worse outcomes in total knee arthroplasty surgery. The aim of this study is to evaluate if the presence of some psychiatric disorders is more frequent in patients who report allergies and if they could be the main cause for the worse outcomes., Methods: A prospective study, including patients undergoing a primary total knee arthroplasty, was designed. In the preoperative visit, all the patients completed a questionnaire about the presence of allergies and also psychiatric tests for anxiety (State-Trait Anxiety Inventory-STAI-), depression (Remission from Depression Questionnaire-RDQ-), somatization disorder (Patient Health Questionnaire-15-PHQ-15-), pain catastrophizing syndrome (Pain Catastrophizing Scale-PCS), and personality disorder (Reduced NEO-Inventory of Five Factors-NEO-FFI-). In the preoperative and at 6 months of follow up, the functional results of the surgery were assessed by the WOMAC, the SF-12, and the KSS scores., Results: A total of 209 patients was included: 136 (65%) did not have reported allergies and 73 (35%) did report some allergies. The psychiatric questionnaires showed that the presence of anxiety was more prevalent in the group of patients with reported allergies (STAI-T: no allergies 24.08 points vs. allergies 19.18 points, p = 0.039). When comparing the functional outcomes at 6 months of follow up, most of the analyzed scores improved less in the group of patients with reported allergies than in the no allergy-referred group: WOMAC-total score (34.37 vs. 40.10 points, p = 0.023), WOMAC-pain score (6.03 vs. 7.50 points, p = 0.018), WOMAC-function score (22.97 vs. 27.24 points, p = 0.023), KSS-knee score (25.37 vs. 33.79 points, p = 0.002), and SF-12 physical score (7.89 vs. 11.15 points, p = 0.046). The significance of the difference in the outcomes scores in this group was lost after adjusting for anxiety (p > 0.05)., Conclusion: Allergies reported by patients are confirmed as a risk factor for worse results after TKA surgery. The relationship with anxiety disorder seems to explain the association between self-reported allergies and sub-optimal outcomes., Level of Evidence: II.

Purpose: Why anterior cruciate ligament (ACL) autograft soaking in a 5 mg/ml vancomycin solution decreases the rate of infection has not been well-explained. One hypothesis is that grafts can be contaminated during harvesting and vancomycin eradicates the bacteria. The purpose of the present study is to assess how the vancomycin solution acts against ACL graft contamination during graft harvesting and preparation., Methods: The study was carried out in three university hospitals over a period of 6 months. After sample size calculation, 50 patients were included in the study. Three samples were taken from each ACL graft. Sample 1 was obtained immediately after graft harvesting. After graft manipulation and preparation, the remaining tissue was divided into two parts. The raw sample was denominated sample 2 and sample 3 consisted of the rest of the remaining tissue that had been soaked in the vancomycin solution. All the cultures were incubated at 37 °C with 5% CO 2 in agar plates for 7 days (aerobically) or 14 days (anaerobically) and inspected daily for microbial growth. Any bacterial growth and the number of colony forming units were reported., Results: In seven cases (14%), either sample 1 or sample 2 was positive. In five of the cases (10%), only the sample after graft preparation was positive (sample 2). In two cases (4%), sample 1 and sample 2 were positive for the same bacteria. Isolated microorganisms corresponded to coagulase-negative staphylococci (CNS) and Propionibacterium acnes. No bacterial growth was observed in sample 3 (p < 0.001). Thus, none of those seven positive cases (0%) were positive after vancomycin soaking (p < 0.001)., Conclusion: In the series, ACL graft harvesting and manipulation leads to bacterial contamination in 14% of the cases. This contamination is fully eradicated after soaking in the vancomycin solution in this series., Level of Evidence: Level II.

Purpose: The hypothesis of this study was that depressive patients feel more pain in the immediate TKA postoperative period in comparison with non-depressed patients., Methods: The diagnosis of depression was made with the Geriatric Depression Scale Short Form. The Visual Analogic Score (VAS) was registered each 8 h during the first 3 days. The mean and maximum VAS and the number of analgesic rescues required in this period were calculated in 803 consecutive TKAs. The Knee Society Score (KSS), the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), and the Short Form-36 (SF-36) scores were obtained preoperatively and at the 1-year follow-up., Results: Forty-eight (6%) of these patients were considered depressed. The results obtained in the depressed patients and non-depressed were, respectively, mean VAS (2.0 vs 1.0, p = 0.00), maximum VAS (5.3 vs 1.6, p = 0.00), and number of rescues needed (4.4 vs 1.8, p = 0.00). Although depressed patients scored worse in the functional and quality of life scores in the preoperative period, the improvement obtained (1-year outcomes minus preoperative outcomes) in the different scores was similar in both groups with the exception of the mental domain of the SF-36, which improved further in depressed patients (p = 0.00)., Conclusion: Depressed patients feel more pain in the immediate postoperative period. However, the improvement obtained in functional and referred quality of life scores is similar to non-depressed patients., Level of Evidence: II.

Purpose: Superficial wound infections do not lead to chronic prosthetic joint infection. Therefore, it has been hypothesized that a superficial infection of a surgical wound following a successfully treated TKA does not lead to a lower functional outcome at long-term follow-up. This may be due to early diagnosis and proper treatment without interrupting the rehabilitation programme. The purpose of this study was to support the hypothesis by comparing the functional outcome and health-related quality of life (HRQoL) of superficial infections treated successfully after primary total knee arthroplasty (TKA)., Methods: In a 3000 prospective TKA cohort, 45 superficial infections were compared to a control group of 629 TKA without complications. The functional outcome, health quality, expectations and revision rate were compared between the study and control groups., Results: The groups were comparable in terms of demographic values and preoperative scores. The mean follow-up was 74.57 months (SD ± 7.1). No statistical differences were observed relative to functional outcomes at the final follow-up as measured with the Knee Society Score (156.9 vs 168.4; n.s) and range of motion (0.2-114.4 vs 0.7-112.3; n.s). For the HRQoL, no differences in the physical (40.0 vs 40.6; n.s) and mental (43.2 vs 45.8; n.s) SF-36 scores were found. Neither were there differences in post-operative expectations and the revision rate., Conclusions: In a long-term follow-up, a different clinical outcome and HRQoL were not obtained after a successfully treated superficial infection following a TKA when compared to a TKA without complications. Based on the findings of the study, additional complications are not anticipated after a successfully treated superficial wound infection in TKA. Therefore, a different follow-up to that of a non-complicated TKA is not recommended when the early post-operative superficial wound infection has been appropriately treated. A superficial infection successfully treated in the acute post-operative period should be considered solved at long-term follow-up., Level of Evidence: Therapeutic study, Level III.

Purpose: The main objective of this study was to analyse the outcomes after total knee arthroplasty (TKA) of a group of patients with at least one self-reported allergy and a group of patients without reported allergies. We hypothesized there is a significant negative influence on clinical outcome scores after TKA in patients with self-reported allergies., Methods: Four-hundred and seventy-five patients who had undergone TKA were analysed preoperatively and 1 year after surgery. The WOMAC, KSS and SF-36 scores were obtained. The patients' Yesavage depression questionnaire score was also recorded. The scores of the 330 (69.5 %) patients without self-reported allergies were compared to the scores of the 145 (30.5 %) patients with at least one self-reported allergy in the medical record., Results: Preoperative scores were similar in both groups. The WOMAC post-operative scores (23.6 vs 20.4; p = 0.037) and the KSS-Knee score (91.1 vs 87.6; p = 0.027) were worse in the group of patients with self-reported allergies than in the group without allergies. The scores from the Yesavage depression questionnaire and in the SF-36 were similar in both groups., Conclusion: Patients with at least one self-reported allergy have worse post-operative outcomes in terms of the WOMAC and KSS-Knee scores after TKA than patients without allergies. These poor outcomes do not seem to be related to depression. Therefore, more research is needed to explain them. Reported allergies could be considered a prognostic factor and used when counselling TKA patients., Level of Evidence: I.

Purpose: To evaluate the effect of the local infiltration of analgesics for pain after total knee arthroplasty in patients treated with femoral and sciatic peripheral nerve blocks. The secondary objective was to detect differences in analgesic consumption as well as blood loss after local infiltration of analgesics., Methods: Prospective randomized double-blinded study in patients who underwent a TKA for knee osteoarthritis under spinal anesthesia and treated with femoral and sciatic nerve blocks. This study compared 50 patients treated with local infiltration with ropivacaine, epinephrine, ketorolac and clonidine and 50 patients treated with a placebo with the same technique. The visual analogic score was registered postoperatively at 2, 6, 12, 24, 36, 48 and 72 h after surgery. Analgesic consumption was also registered. Both groups of patients were treated with the same surgical and rehabilitation protocols., Results: A significant difference of one point was found in the visual analogic pain scores 12 h after surgery (0.6 ± 1.5 vs. 1.7 ± 2.3). There were no significant differences in the visual analogic pain scores evaluated at any other time between 2 and 72 h after surgery. No significant differences were found in the required doses of tramadol or morphine in the postoperative period. Postoperative hemoglobin and blood loss were also similar in both groups., Conclusion: Adding local infiltration of analgesics to peripheral nerve blocks after TKA surgery only provides minimal benefit for pain control. This benefit may be considered as non-clinically relevant. Moreover, the need for additional analgesics was the same in both groups. Therefore, the use of local infiltration of analgesics treatment in TKA surgery cannot be recommended if peripheral nerve blocks are used., Level of Evidence: I.

Purpose: The main objective of this study was to compare the functional results and the impact on quality of life after a single-radius or a multiradius TKA implantation. The secondary objectives were to compare range of motion, satisfaction and the ability to perform daily life activities with both types of implant. It was hypothesized that the single-radius TKA would lead to better functional results and better quality of life than the multiradius TKA., Methods: This is a prospective non-randomized study that included 250 cases of a single-radius TKA and 224 of a multiradius posterior-stabilized TKA implanted with the same surgical and rehabilitation protocol., Results: In the 1- and 5-year follow-up, we found similar knee KSS scores (89.7 ± 12.1 in the multiradius group and 90.3 ± 11.7 in the single-radius group) and functional KSS scores (78.6 ± 21.4 in the multiradius group and 75.8 ± 20.9 in the single-radius group). The pain and the Physical SF-36 scores were also similar. Range of motion (112° ± 12° in the multiradius group and 112 ± 12° in the single-radius group), patients' satisfaction and the ability to perform daily life activities were also similar in both groups., Conclusion: The use of a single-radius or a multiradius posterior-stabilized knee prosthesis can improve the function of the knee and the patients' quality of life in a similar way at the short-term and midterm follow-up. Moreover, range of motion, patient satisfaction and the ability to perform daily life activities are similar with both types of prosthesis. As both types of prosthesis can improve the function and quality of life of the patients in a similar way, the sagittal radius of the femoral component should not be considered the main factor when choosing the model of TKA., Level of Evidence: Therapeutic study: Prospective comparative study, Level II.

Purpose: The Knee Society Clinical Rating System (KSS) is a questionnaire evaluating knee function itself and the patient's ability to walk and climb stairs. The aim of our study is to present the validated translation of KSS into Spanish., Methods: The validated method of translation-retrotranslation was used to translate KSS into Spanish. Three hundred and sixteen patients undergoing primary knee arthroplasty, before surgery and 6 months postoperative, completed the questionnaire (with an orthopedist's help). Psychometric properties of feasibility (percentage of no answers), validity and sensitivity to change (test's ability to detect change in patients' functional status over time) were assessed. In the second part of the study, the translated version of KSS was compared with two already validated questionnaires (SF-36 and WOMAC)., Results: During the translation process, item 3 (ROM) presented low appropriateness and null comprehensibility. The alternative writing proposed was 'for every 5°, we sum up 1 point, as if 8° were 1 point, to obtain the maximum scoring of 25 points you should bend more than 200°'. Feasibility: the item 'malalignment' obtained 15 % of missing item at visit 1. The percentage of invalid items was high in both visits (60 and 47 %)., Validity: the coefficients of convergent correlation with WOMAC and SF-36 scales confirm the questionnaire's validity. Sensitivity to change: significant differences were found in all cases between the mean scores comparing both visits., Conclusion: The translated version 1.1 of KSS (final version) has shown to be feasible, valid and sensible to changes within the clinical practice of patients undergoing primary knees arthroplasty.

The aim of this study was to compare blood loss and transfusion requirements in patients undergoing computer-assisted total knee arthroplasty (TKA) and patients operated with conventional instrumentation with intra-medullar guides. A prospective randomized study of 87 patients undergoing a TKA assigned to conventional technique (n = 44) or computer-assisted surgery (n = 43) was conducted. All patients were operated by the same surgeon and in all cases a cemented arthroplasty and deep recovery drainage were used. Both groups were comparable in all variables except for duration of ischemia, which was 13.7 min higher in the computer-assisted group. Blood loss due to drainage was higher in the conventional technique group (613 vs. 447 ml), as was the number of patients in which blood from the blood recovery system was reinfused (53 vs. 23%). Those patients undergoing computer-assisted surgery experienced less bleeding than those operated with the conventional technique. However, hemoglobin drop and allogenic transfusion rate were not statistically different in both groups.