Clinical Outcomes After Polyurethane Meniscal Scaffolds Implantation Remain Stable Despite a Joint Space Narrowing at 10-Year Follow-Up.

PURPOSE: To report the clinical outcomes, radiologic evolution, and survivorship of a series of patients affected by the postmeniscectomy syndrome and treated with a polyurethane scaffold at a minimum 10-year follow-up. In addition, the radiologic evolution of these patients was also assessed. METHODS: All the patients operated on with a polyurethane meniscal scaffold implantation to treat postmeniscectomy syndrome from 2008 to 2011 were prospectively followed. Clinical evaluations and radiologic studies were assessed at the preoperative period, at 5-year follow-up, and at minimum 10-year follow-up. Clinical outcomes were based on patient-reported outcomes (e.g., the Knee injury and Osteoarthritis Outcome Score, International Knee Documentation Committee, Lysholm, and Tegner). Radiographical evaluation of the joint-space narrowing was done in the Rosenberg view. Failure was defined as patients who required surgery to remove the scaffold or those patients who needed surgery for a total or partial knee replacement. RESULTS: Twenty-one of 27 patients, with a mean age of 56 ± 9.8 years, were available for the final follow-up. The mean follow-up was 11.8 (range, 10-12.7) years. Six patients were lost to follow-up. All functional scores showed a significant improvement (P < .001) at the 5- and 10-year follow-up. The exception was the Tegner score, which remained stable. The joint-space width was maintained from the preoperative period (1.9 ± 1.2 mm) up to the 5-year follow-up (1.3 ± 1.5 mm, P = .3) and decreased by the last evaluation (0.6 ± 1.2 mm, P = .001) at the last follow-up. Two (9.5%) of 21 patients were converted to a total knee replacement during the study period. None of the other patients needed revision surgery during the study period. CONCLUSIONS: The polyurethane meniscal scaffold provides significant and stable pain relief over time and improved functional outcomes at a minimum of 10 years after surgery. However, degenerative changes progressed in the treated compartment, with a joint-space narrowing over the 10-year period. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Patellar bone defect grafting does not reduce anterior knee pain after bone-patellar tendon-bone anterior cruciate ligament reconstruction.

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.

Comparable bone penetration between antibiotic-loaded and plain bone cement in total knee arthroplasty.

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.

Plastic waste in major orthopaedic surgical procedures: descriptive and sources of improvement.

PURPOSE: The healthcare industry is a significant contributor to single-use plastic waste, particularly in the operating room (OR). This study aims to assess the volume of plastic waste generated during total hip, knee, and shoulder arthroplasty in the OR and identify areas for improvement. METHOD: A prospective transversal study at a tertiary hospital was conducted. All total knee arthroplasty (TKA), total hip arthroplasty (THA), and reverse shoulder arthroplasty (RSA) from April to July 2021 were included. The weight of plastic used during patient preparation, anaesthesia, and the surgical procedure was recorded. To calculate the environmental impact, a calculator generated by the United States Environmental Protection Agency (U.S. EPA) was used. RESULTS: A total of 68 surgeries were included. The mean weight of plastic used in total was 7.3 kg (SD 0.48), with the highest yielding procedure being TKA. It generated a mean of 7.63 kg (SD 0.28), followed by THA at 7.28 kg (SD 0.43), and RSA at 6.87 kg (SD 0.47). Various scenarios were simulated to evaluate the potential impact of reducing plastic waste. Substituting plastic wrapping with recyclable materials could save 159.6 kg of CO2 emissions per 100 prostheses. Eliminating non-essential equipment and adopting reusable fabric drapes also showed a significant potential. CONCLUSION: The findings highlight the need for environmentally sustainable practices in the OR. In this way, the healthcare sector can contribute to a cleaner and greener world without compromising patient safety.

The distal tibiofibular syndesmosis is a reliable landmark for 3° varus tibial resection in total knee arthroplasty: a radiological evaluation on 1296 cases.

PURPOSE: The purpose of this study was to evaluate the reproducibility and the accuracy of distal tibiofibular syndesmosis (DTFS) as landmark to perform controlled varus tibial resections during total knee arthroplasty (TKA). The hypothesis was that DTFS can be used to perform an accurate 3° varus tibial cut. METHODS: A retrospective analysis on a consecutive series of standard weightbearing full-length anteroposterior views of the lower limbs radiographic images was conducted. For each radiograph, the hip-knee-ankle (HKA) angle, the angle between the tibial mechanical axis and the line connecting the centre of the tibial spines and the DTFS (tibiofibular angle, TFA) and the medial proximal tibial angle (MPTA) were calculated. Each measurement was carried out twice by three independent observers, and intra- and inter-observer measurement reliability were assessed using the intraclass correlation coefficient (ICC) analysis. RESULTS: A total of 1296 lower limbs were analysed from a series of 648 weightbearing full-length anteroposterior radiographs. The ICC were > 90% for all measurements. The mean TFA value was 2.94 ± 0.68 (range 2.38-3.51). No differences were detected comparing the mean TFA value on the right and left limb (p = 0.795) as well as comparing the values in male and female patients (p = 0.691). Linear regression analysis did not find statistically significant correlation between TFA and MPTA, or TFA and HKA angles, respectively. CONCLUSION: The distal tibiofibular syndesmosis is a reliable and easy reproducible radiographic landmark that can be used when planning a 3° varus tibial cut. Future studies are needed to confirm the validity of this method also in clinical settings. LEVEL OF EVIDENCE: IV, retrospective case series.

Good clinical outcomes can be expected after meniscal allograft transplantation at 15 years of follow-up.

PURPOSE: The aim of this study was to evaluate graft survivorship and report the functional and radiographic results of Meniscal allograft transplantation (MAT) throughout a minimum 15-year follow-up period. METHODS: Fifty-one patients that had undergone an isolated MAT procedure during the period studied were included. The results were assessed with the Lysholm and Tegner scores as well as the Visual Analog Scale. Magnetic resonance imaging and a complete radiographic series were carried out to determine the degree of meniscal extrusion and joint space narrowing. A comparison was made between the radiological findings of the last follow-up, the 5-year mid-term follow-up and those from the preoperative period. RESULTS: Thirty-eight patients were available for the final follow-up. The mean follow-up was 17.4 years. There were 23 (60.5%) medial menisci and 15 lateral menisci (39.4%). Meniscal extrusion increased from the 29.7% ± 14.9 obtained at the 5-year follow-up to the 72.5% ± 22.5 seen at the end of the follow-up (p = 0.0001). The joint space distance was almost unchanged from the initial evaluation (3.3 ± 1.5 mm) to the 5-year follow-up measurement (3.1 ± 1.7 mm, n.s.). However, it did decrease at the last follow-up (1.9 ± 1.5 mm, p < 0.05). The functional outcomes improved from the preoperative period to the mid-term follow-up and later worsened at the final follow-up. The mean preoperative Lysholm score at the initial follow-up was 61.5 ± 9.6, 86.9 ± 10.9 for the 5-year evaluation and stood at 77.4 ± 11.5 (p = 0.0001) at the final follow-up. Regarding the Tegner score, those pre-operative scores were compared to the ones at the last follow-up (median: 3; range 0-6 vs. 5.5; 3-6, respectively; p = 0.0001). The VAS went down from 6.6 ± 1.7 at the initial evaluation to 2.5 ± 1.9 at the final follow-up (p = 0.0001). The joint-space width remained unchanged from the initial evaluation (3.35 ± 1.5 mm) up to the 5-year follow-up measurement (3.1 ± 1.7 mm, n.s.). However, this joint-space distance had decreased by the last evaluation in the long-term follow-up (1.9 ± 1.4 mm, p < 0.05). Five patients (13.1%) presented with a MAT failure at 5 years, which was followed by extirpation of the meniscal graft. At the final follow-up, a total of 16 patients (42.1%) presented with a failure. At that time, there were 4 more MAT removals and seven patients that required a total knee replacement. The mean time to failure of the meniscal graft was 206.2 months ± 13.4 (18.0 years). CONCLUSIONS: Meniscal allograft transplantation produces good functional results at a minimum 15-year follow-up. However, degenerative arthritis in the affected compartment progressed during that period. LEVEL OF EVIDENCE: III.

Systematic lateral retinacular release does not reduce anterior knee pain after total knee arthroplasty with patellar resurfacing.

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.

Isolated lateral extra-articular tenodesis in ACL-deficient knees: in vivo knee kinematics and clinical outcomes.

PURPOSE: To carry out an in vivo kinematic analysis of isolated modified Lemaire lateral extra-articular tenodesis (LET) to explore its ability to modify the stability of anterior cruciate ligament (ACL) deficient knees. The secondary aim was to look at the clinical outcomes of the isolated LET to analyze whether biomechanical changes have an influence on clinical improvement or not. METHODS: A total of 52 patients who underwent an isolated modified Lemaire LET were prospectively studied. Twenty-two were over 55-year-old patients with ACL rupture and subjective instability (group 1). They were followed up for 2 years postoperatively. Thirty were patients underwent a two-stage ACL revision (group 2). They were followed up for 4 months postoperatively (up to the second stage of the ACL revision). Preoperative, intraoperative, and postoperative kinematic analyses were carried out using the KiRA accelerometer and KT1000 arthrometer to look for residual anterolateral rotational instability and residual anteroposterior instability. Functional outcomes were measured with the single-leg vertical jump test (SLVJT) and the single-leg hop test (SLHT). Clinical outcomes were evaluated using the IKDC 2000, Lysholm, and Tegner scores. RESULTS: A significant reduction of both rotational and anteroposterior instability was detected. It was present both with the patient under anesthesia (p < 0.001 and p = 0.007 respectively) as well as with the patient awake (p = 0.008 and p = 0.018 respectively). Postoperative analysis of knee laxity did not show any significant variation from the first to the last follow-up. Both the SLVJT and SLHT improved significantly at the last follow-up (p < 0.001 and p = 0.011 respectively). The mean values of both the IKDC and Lysholm and Tegner scores showed an improvement (p = 0.008; p = 0.012; p < 0.001). CONCLUSION: The modified Lemaire LET improves the kinematics of ACL-deficient knees. The improvement in the kinematics leads to an improvement in subjective stability as well as in the function of the knee and in the clinical outcomes. At the 2-year follow-up, these improvements were maintained in a cohort of patients over 55 years. Following our findings, to reduce knee instability, an isolated LET in ACL-deficient knees may be used when ACL reconstruction in patients over 55 years is not indicated. LEVEL OF EVIDENCE: Level IV.

Fibronectin-coated polyurethane meniscal scaffolding supplemented with MSCs improves scaffold integration and proteoglycan production in a rabbit model.

PURPOSE: The role of mesenchymal stem cells (MSC) in supporting the formation of new meniscal tissue in a meniscal scaffold is not well understood. The objective of this study was to assess the quality of the meniscal tissue produced in a fibronectin (FN)-coated polyurethane (PU) meniscal scaffold after a meniscal injury was made in an experimental rabbit model. METHODS: Twelve New Zealand white rabbits were divided in two groups after performing a medial meniscectomy of the anterior horn. In group 1, the meniscal defect was reconstructed with a non-MSC supplemented FN-coated PU scaffold. On the other hand, the same scaffold supplemented with MSCs was used in group 2. The animals were sacrificed at 12 week after index surgery. A modified scoring system was used for histological assessment. This new scoring (ranging from 0 to 15) includes a structural evaluation (meniscal scaffold interface and extracellular matrix production) and tissue quality evaluation (proteoglycan and type I-collagen content). RESULTS: The meniscal scaffold was found loose in the joint in three cases, corresponding to two cases in group 1 and 1 case in group 2. No differences were observed between the groups in terms of the total score (7.0 ± 0.9 vs. 9.4 ± 2.6, p = 0.09). However, differences were observed in group 2 in which 2 out of the 5 scored items, scaffold integration (1 ± 0.0 vs. 1.9 ± 0.6, p = 0.03) and proteoglycan production (1.2 ± 0.3 vs. 2.4 ± 0.2, p = 0.001). A trend to a higher production of Type I-Collagen production was also observed in group 2 (1.1 ± 0.4 vs. 1.4 ± 0.7, p = 0.05). CONCLUSION: In a rabbit model at 12 weeks, the adhesion of MSCs to a FN-coated PU scaffold improves scaffold integration, proteoglycan production and the characteristics of the new meniscal-like tissue obtained when compared to a non-supplemented scaffold. This fact could be a major step toward improving the adhesion of the MSCs to meniscal scaffolds and, consequently, the obtention of better quality meniscal tissue.

The technique of cement application has no influence on cement intrusion in total knee arthroplasty: randomized study comparing three different techniques.

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.

Increased posterior translation but similar clinical outcomes using ultracongruent instead of posterior stabilized total knee arthroplasties in a prospective randomized trial.

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.

Preoperative muscle thickness influences muscle activation after arthroscopic knee surgery.

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.

Patients lose weight after a total knee arthroplasty: myth or reality?

BACKGROUND: Obesity is one of most discussed factors when assessing prosthetic knee surgery outcomes. Prior to the procedure, most patients perceive that their excessive weight is secondary to the low level of activity due to limiting knee pain. OBJECTIVES: The main objective of this study was to assess whether patients undergoing total knee arthroplasty (TKA) lose weight after the procedure. The secondary objective was to correlate weight loss with post-operative knee function. METHODS: A prospective observational study was designed including 247 patients who undergone TKA from January 2018 to January 2019. A significant change in weight was considered anything above or below 5% of the pre-operative weight. Three groups were established based on a change in weight: loss of more than 5%, those who did not pass above or below 5% of their initial weight and increase of more than 5%. Follow-up was carried out at 12 months after the intervention assessing patient's BMI (kg/m2), functional level (KSS), weight loss expectations, and range of motion. RESULTS: Among the total population, 17 (6.9%) lost weight, 168 (68%) did not have a change, and 62 (25.1%) increased weight at one year follow-up. The mean pre-operative BMI was 31.5 kg/m2, and mean postoperative BMI was 31.98 kg/m2. Furthermore, obese patients were more likely to present weight reduction than non-obese (p = 0.01). When comparing functional results between groups, no differences were observed in terms of KSS-K and KSS-F. CONCLUSION: Patients who undergo TKA do not lose weight one year after surgery. When correlating weight loss with post-operative outcomes, no differences were observed between groups.

Patellar denervation does not reduce post-operative anterior knee pain after primary total knee arthroplasty with patellar resurfacing.

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/m2 (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.

Limb length discrepancy after total knee arthroplasty may contribute to suboptimal functional results.

PURPOSE: Limb length discrepancy (LLD) has been related to inferior outcomes after total hip arthroplasty (THA), but few studies have dealt with the LLD in primary total knee arthroplasty (TKA). The aims of the study were to examine the incidence of LLD after TKA and how it can influence in the outcomes scores. METHODS: We analysed preoperative, postoperative and changes in LLD in 460 patients who underwent a unilateral primary TKA. The measurements were done on digital full leg radiographs preoperatively and 6 months after surgery. The hip-knee-ankle (HKA) angle was also measured on these radiographs. Patients were evaluated with the Knee Society Score (KSS) preoperatively and 12 months after surgery. RESULTS: The average LLD was 1.1 mm in the preoperative period and changed to -0.8 mm in the postoperative (the 1.9 mm lengthening of the operated limb was statistically significant (p < 0.001)). LLD increase was correlated with preoperative HKA angle and with HKA angle changes. Only 8.3% of the patients had significant postoperative LLD (≥ 10 mm), but they had a significant worse function outcome in the KSS one year after surgery than patients with negligible postoperative LLD (< 10 mm) (76.7 vs 82.3; p = 0.02). CONCLUSIONS: Unlike THA surgery, significant LLD is not frequent after TKA surgery, but the functional results of the surgery can be suboptimal when it is present.

Pressure algometry is a suitable tool to assess anterior knee pain in osteoarthritic patients.

PURPOSE: Anterior knee pain is a frequent symptom in the osteoarthritic knee. Its intensity has been classically evaluated by the visual analogic score (VAS). The main objective of the study was to assess whether pressure algometry (PA) can be used as a reliable tool to quantify anterior pain in the osteoarthritic knee. METHODS: A prospective study was designed, including 160 patients scheduled for unilateral total knee arthroplasty. Patellar pain and function were evaluated according to a specific patellofemoral pain questionnaire and the Knee Society Score. Patients were asked about their pain at rest, while walking and in the stairs with the VAS score. PA by an algometer was used in the anterior part of the patella to determine the pressure pain threshold (PPT): the minimal pressure when the patient feels a painful sensation. RESULTS: The mean values of PPT were 385.1 kPa in the knees going to be operated and 403.4 kPa in the contralateral knees (p < 0.05). The anterior knee pain in the patellar score averaged 6.9, and the total patellar score averaged 15.2. PPT values were correlated with the anterior pain in the patellar score (ρ = 0.31, p < 0.001) and also with the total patellar score (ρ = 0.33; p < 0.001). CONCLUSIONS: PA demonstrated to be suitable to measure anterior knee pain in the osteoarthritic knee. PA can specifically assess the anterior knee pain better than other methods as VAS score. PA could be used as the main measurement when comparing different treatments for the anterior knee pain caused by osteoarthritis.

Magnetic Resonance Imaging and Functional Outcomes After a Polyurethane Meniscal Scaffold Implantation: Minimum 5-Year Follow-up.

PURPOSE: To report the magnetic resonance imaging (MRI) and clinical outcomes at a minimum 5-year follow-up in a series of patients with postmeniscectomy syndrome and treated with a polyurethane scaffold. METHODS: All consecutive patients operated on from September 2008 to February 2011 for either persistent medial or lateral joint line compartmental pain receiving a polyurethane scaffold due to a previous partial meniscus resection with a minimum 5-year follow-up were included. Functional scores (Knee Injury and Osteoarthritis Outcomes Score, International Knee Documentation Committee, Lysholm, and Tegner) were assessed preoperatively and at the last follow-up. The state of the scaffold as well as postoperative scaffold extrusion and the total remaining meniscal volume was also evaluated in MRI. RESULTS: Thirty-two patients were included. The mean follow-up was 70.8 ± 7.5 months. The functionality of the knees improved in all the scores used (P < .001) except for the Tegner score that stayed steady. Most of meniscal implants showed extrusion of 2.4 mm (95% confidence interval [CI], 1.1-3.7) were smaller and a hyperintensity signal was seen in the MRI. Three scaffolds were resorbed at the last follow-up. The meniscal volume, determined by MRI, was 1.14 cm3 (95% CI, 0.96-1.31) preoperatively and 1.61 cm3 (95% CI, 1.43-1.7) at the last follow-up. No differences were presented. CONCLUSIONS: The use of a polyurethane meniscal scaffold in patients with a symptomatic meniscus deficit had a good functional outcome at 5 years after surgery. However, the implanted scaffolds did not present normal meniscal tissue with MRI, and the implant volume was considerably less than expected. The fact that most of patients included received different concomitant procedures during scaffold implantation introduces a degree of performance bias into the results. LEVEL OF EVIDENCE: Level IV, case series.

Contamination occurs during ACL graft harvesting and manipulation, but it can be easily eradicated.

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% CO2 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.

Depressed patients feel more pain in the short term after total knee arthroplasty.

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.

Autograft soaking in vancomycin reduces the risk of infection after anterior cruciate ligament reconstruction.

PURPOSE: To determine whether the bathing of an anterior cruciate ligament (ACL) autograft in vancomycin reduces the rate of infection following an ACL reconstruction. METHODS: Retrospective analysis of all ACL reconstructions over an 8-year period in two University Hospitals. In the initial 4-year period, all patients were operated on under classical antibiotic intravenous prophylaxis (group 1). Over the last 4-year period, this prophylaxis was supplemented with presoaking of the autograft (group 2). Presoaking was performed with sterile gauze previously saturated with a vancomycin solution (5 mg/ml). RESULTS: There were 810 and 734 patients in group 1 and 2, respectively. Fifteen cases of knee joint infections were identified in the series (0.97 %). All of these infections occurred in group 1, representing a rate of infection of 1.85 % in comparison with 0 % in group 2 (p < 0.001). CONCLUSIONS: Autograft presoaking with vancomycin in combination with classical intravenous antibiotic prophylaxis reduced the rate of knee joint infection following an ACLR in comparison with antibiotic prophylaxis alone. This technique could be of relevance in daily clinical practice to prevent infection after ACLR. LEVEL OF EVIDENCE: Case control study, retrospective comparative study, Level III.