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.

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.

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.

Superficial wound infection does not cause inferior clinical outcome after TKA.

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.

Managing septic arthritis after knee ligament reconstruction.

PURPOSE: Joint infection after anterior cruciate ligament (ACL) reconstruction is uncommon but has potentially serious consequences for the graft and articular cartilage. Most recently published series are in agreement that an urgent arthroscopic washout and antibiotic treatment are mandatory to preserve both graft and cartilage. However, several questions have not as yet been touched upon. METHODS: We performed a literature review to assess the most interesting series published about this issue. RESULTS: In this review, a management protocol is first presented that discusses the different diagnostic parameters to consider and surgical and antibiotic treatment suggested according to the literature. Outcomes published in different series are also discussed.

An Evaluation of the Association Between Radiographic Intercondylar Notch Narrowing and Anterior Cruciate Ligament Injury in Men: The Notch Angle Is a Better Parameter Than Notch Width.

PURPOSE: To evaluate the association of anterior cruciate ligament (ACL) injuries with the intercondylar notch angle and notch width in male patients. The secondary purpose was to evaluate the association of these injuries with other novel morphologic parameters. METHODS: Male patients undergoing primary ACL reconstruction between 2010 and 2013 for injury through noncontact mechanisms with preoperative magnetic resonance imaging were compared with an age-matched control group of male patients (patients who underwent knee operations other than ACL reconstruction) regarding the following magnetic resonance imaging-assessed parameters: intercondylar notch angle, width, and depth; condylar width; medial/lateral condylar widths; medial/lateral posterior tibial plateau slopes; anterior sagittal tibial slope (corresponding to the level of the tibial ACL footprint); coronal tibial slope; and angle between the Blumensaat line and anterior tibial slope. RESULTS: In both the coronal and axial planes, patients with ACL injury had a significantly lower intercondylar notch angle (P < .001 and P = .008, respectively) than the control group, but there were no significant between-group differences for intercondylar notch width (P = .9 and P = .97, respectively). In the sagittal plane, patients with ACL injury had significantly higher medial (P < .001) and lateral (P = .02) posterior tibial slopes, a significantly lower anterior tibial slope (P = .01), and a significantly higher angle between the Blumensaat line and anterior tibial slope (P = .02) than the control group. CONCLUSIONS: Narrowing of the intercondylar notch may be associated with ACL injury in male patients. However, the intercondylar notch angle may be a better parameter to evaluate notch narrowing and its potential association with ACL injuries compared with the notch width. The association between the angle formed by the Blumensaat line and anterior tibial slope and ACL injuries in male patients needs more investigation. This study further suggests that increased posterior tibial slope may be associated with ACL injury in male patients. LEVEL OF EVIDENCE: Level III, case-control study.

Long term follow-up of successfully treated superficial wound infections following TKA.

The relevance of wound complications in association with acute prosthetic joint infection (PJI) is well known. However, whether a successfully treated superficial infection can result in a chronic deep infection remains unclear. The aim of this study was to determine the prevalence, treatment and late complications of superficial wound infections following TKA. In a 3000 TKA prospective cohort, 45 superficial infections were diagnosed and treated successfully with antibiotic therapy along with or without surgical debridement. None of the cases developed deep chronic PJI at 70 months of follow-up. Three cases were in need of a TKA exchange due to aseptic loosening. A successfully treated superficial wound infection does not result in a chronic deep TKA infection.

Influence of depression on total knee arthroplasty outcomes.

It is not clear whether indicating TKA-surgery is advisable in depressed patients. A prospective cohort of 716 patients undergoing TKA was designed. SF36, KSS, WOMAC and VAS plus 2 satisfaction questions were evaluated. There were 2 groups: 200 patients were depressed and 516 were not. Preoperative/postoperative results show better scores for non-depressed patients on almost every sub-scale. Nevertheless, net change results (improvement) were quite similar: 65.74 improvement in depressed-KSS and 74.58 in non-depressed (P=0.049); 8.93 net change in depressed-Physical Composite Score and 11.84 in non-depressed (P=0.003); 2.38 in depressed-Mental Composite Score and -0.61 in non-depressed (P=0.024). Depressed patients obtained great improvement from preoperative at one-year follow-up and even greater than non-depressed patients in some domains. Moreover, satisfaction was similar. Therefore, TKA can be recommended to depressed patients.

Standard Versus Dysplastic Inlay Implant for Patellofemoral Arthroplasty: Surgical Technique and Decision-Making.

Patellofemoral arthroplasty (PFA) has emerged as an alternative bone-preserving surgical option for treating isolated symptomatic patellofemoral osteoarthritis that better replicates the natural knee kinematics compared with total knee arthroplasty. Achieving successful outcomes in PFA relies on meticulous patient selection, proper surgical technique, and appropriate implant choice and placement. Recent advancements in inlay trochlea implants, allowing for customized and anatomic joint line reconstruction with less bone resection, have demonstrated significant improvements in functional outcome scores and pain relief. This Technical Note aims to provide insights into the surgical technique of PFA with inlay implants, highlighting key considerations and potential challenges. It also assists surgeons in making informed decisions regarding the choice between standard and dysplastic inlay implants, while suggesting concurrent procedures to optimize tracking and overall outcomes.

Effects of an educational audiovisual videodisc on patients' pre-operative expectations with total knee arthroplasty: a prospective randomized comparative study.

PURPOSE: To investigate the effectiveness of an educational videodisc in modifying pre-operative patients' expectations with total knee arthroplasty (TKA) and to find a biophysical profile of subjects in whom this videodisc could be most effective. It was hypothesized that patients receiving standard information plus additional medical information through audiovisual videodiscs would modify their pre-operative expectations more than those only receiving the standard information through medical interviews. METHODS: Ninety-two patients (age, 50-90 years) with knee osteoarthritis waiting for TKA were randomized into two groups. All patients received general verbal information about this procedure. Forty-two patients (study group) additionally viewed an educational videodisc related to the whole process of TKA, whereas 50 patients did not view it (control group). Patients completed baseline and post-videodisc questionnaires regarding their expected results after TKA. RESULTS: Expectations with TKA were not modified by the audiovisual videodisc, except for knee range of motion and use of stairs. There were no differences in change of expectations between groups depending on demographic, functional, health, emotional, and cognitive variables, except for body mass index. The overall pre-operative, pre-intervention expectations were not modified by the audiovisual videodisc. CONCLUSIONS: Based on these results, the use of this complementary tool may not be systematically recommended. In addition, it was not possible to identify a biophysical profile of patients in whom the intervention could be most effective.

A lower starting point for the medial cut increases the posterior slope in opening-wedge high tibial osteotomy: a cadaveric study.

PURPOSE: The objective of this study was to evaluate the effects on the posterior tibial slope of different distances from the joint line to start the osteotomy and of varying the placement of the opening wedge in high tibial osteotomy. Starting the osteotomy more distally and an incorrect location for the tibial opening wedge were hypothesized to increase the posterior tibial slope. METHODS: A cadaveric study was conducted using 12 knees divided into two groups based on the distance from the joint line to the start of the osteotomy: 3 and 4 cm. The preintervention posterior tibial slope was measured radiologically. Once the osteotomy was performed, the medial cortex of the tibia was divided into anteromedial, medial, and posteromedial thirds. A 10° opening wedge was sequentially placed in each third, and the effect on the posterior tibial slope was evaluated radiographically. RESULTS: Significant changes were observed only in the 3-cm group (p = 0.02) when the wedge was placed in the anteromedial zone. In contrast, in the 4-cm group, significant differences were observed when the opening wedge was placed at both the medial (p = 0.04) and anteromedial (p = 0.012) zones. CONCLUSION: Correct control of the posterior tibial slope can be achieved by avoiding a low point when beginning the osteotomy and placing the opening wedge in the posteromedial third of the tibia when performing an opening-wedge high tibial osteotomy. LEVEL OF EVIDENCE: Controlled laboratory study.

Continuous passive motion not affect the knee motion and the surgical wound aspect after total knee arthroplasty.

BACKGROUND: This study aimed to assess whether use of continuous passive motion (CPM) could improve range of motion in patients after total knee arthroplasty (TKA), if it could affect the surgical wound aspect (SWA) and if it could influence on pain management after TKA. METHODS: We randomized 210 patients in two groups, 102 patients in the CPM group, who received a standard rehabilitation protocol together with CPM application; and 108 patients in the no-CPM group, without CPM. Variables as knee motion (flexion, extension, range of motion) and pain were measured before surgery, on the 1st, 2nd and 3rd postoperative day, and in the 2nd, 6th, 12th and 24th postoperative weeks following TKA. The SWA was determined by the "surgical wound aspect score" (SWAS) in the next 48 h after surgery. This scale analyzes swelling, erythema, hematoma, blood drainage and blisters. RESULTS: There was an improvement in the knee motion over the course of follow-up in both groups, without significant difference in flexion parameter. We found no significant differences in the total score of SWA, except for hematoma, with less severity in the CPM group. Furthermore, we found no differences in the others SWAS parameters and pain. CONCLUSIONS: The application of CPM does not provide benefit to our patients undergoing TKA in terms of either improved flexion mobility or decreased pain. No relationship was found between the use of CPM and the global score of SWA following a TKA, except for a decrease in hematoma appearance.

Anterior cruciate ligament reconstruction: a multicenter prospective cohort study evaluating 3 different grafts using same bone drilling method.

OBJECTIVE: To compare the clinical outcomes after anterior cruciate ligament (ACL) reconstruction with bone-patellar tendon-bone autograft (BPTBAu), BPTB allograft (BPTBAll), or hamstring (semitendinosus-gracilis) tendon autograft (HTAu), performing bone drilling with same methods in terms of transtibial drilling, orientation, positioning, and width of femoral and tibial tunnels. DESIGN: Multicenter prospective cohort study (level of evidence II). SETTING: Departments of Orthopedic Surgery of Centro Médico Teknon (Barcelona, Spain) Clínica Universitaria de Navarra (Navarra, Spain), and Clínica FREMAP (Gijón, Spain). PATIENTS: All patients with ACL tears attending 3 different institutions between January 2004 and June 2006 were approached for eligibility and those meeting inclusion criteria finally participated in this study. INTERVENTION: Each institution was assigned to perform a specific surgical technique. Patients were prospectively followed after undergoing ACL reconstruction with BPTBAu, BPTBAll, or HTAu, with a minimum follow-up of 24 months. MAIN OUTCOME MEASURES: Included knee laxity and International Knee Documentation Committee (IKDC) score. Knee laxity was assessed with the KT-1000 arthrometer (evaluated with neutral and external rotation positions) and both Lachman and pivot shift tests. Additional outcomes included main symptoms (anterior knee pain, swelling, crepitation, and instability), disturbance in knee sensation, visual analogue scale (VAS) for satisfaction with surgery, range of motion (ROM), and isokinetic knee strength. RESULTS: There were no significant differences among the 3 groups for any of the clinical outcomes, except for a slightly greater KT-1000-measured knee laxity in external rotation in the BPTBAu compared with the other groups. All patients demonstrated grade A or B of the IKDC. The mean VAS for satisfaction with surgery in all patients was 8.5. CONCLUSIONS: The selection of the surgical technique for ACL reconstruction may be based on the surgeon's preferences.

Patellofemoral Pain After Arthroscopy: Muscle Atrophy Is Not Everything.

BACKGROUND: It remains unclear as to why patellofemoral pain (PFP) appears in some patients after knee arthroscopy and what influence the quadriceps muscle has on its onset. PURPOSE: To compare muscle thickness, neuromuscular contractility, and quadriceps femoris muscle strength between patients who develop PFP after arthroscopic partial meniscectomy and a control group and to compare functional outcomes between these entities. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A prospective longitudinal cohort study was carried out on patients scheduled for arthroscopic partial meniscectomy. Patients were excluded if they had preoperative PFP, previous knee surgery, or additional surgical procedures (eg, meniscal repair or microfracture). The following were performed preoperatively: magnetic resonance imaging to quantify muscle thickness, surface electromyography to analyze electrical contractility, and an isokinetic study to assess the strength of the quadriceps femoris muscle. Patients also completed a Lysholm functional questionnaire. Six weeks after the index procedure, patients were questioned about the presence of PFP, and the same tests were repeated. The PFP group included patients who developed anterior knee pain postoperatively, while the control group included those who did not develop pain. RESULTS: Of 90 initial study patients, 20 were included in the PFP group (23.8%) and 64 in the control group (76.2%); 6 patients were lost to follow-up. Both study groups were comparable on all of the analyzed preoperative variables. Patients in the PFP group had worse results in terms of muscle thickness (9.67 vs 16.55 cm2), electrical contractility (1226.30 vs 1946.11 µV), and quadriceps strength (12.27 vs 20.02 kg; all P < .001). They also presented worse functional results on the Lysholm score (63.05 vs 74.45; P < .001). CONCLUSION: Patients who developed PFP after arthroscopic partial meniscectomy had more quadriceps femoris muscle atrophy as well as a greater decrease in electrical contractility and muscle strength at 6 weeks postsurgically as compared with a control group. The PFP group also had worse postoperative functional results.

Barbed Sutures in Total Knee Arthroplasty: Are They Really Useful? A Randomized Controlled Trial.

Bidirectional barbed sutures (BBSs) have recently been investigated in total knee arthroplasty (TKA). The contrasting results from the scarce literature suggest that BBSs are safe, save time and money, and give results comparable to traditional sutures. The purpose of the study is to test the real effect of BBSs on closure time in TKA and assess the functional results as well as the complications related to them. It was a randomized controlled trial. Eighty-five patients undergoing primary TKA were assigned to receive traditional closure with Vicryl (V-group) or with BBSs (Q-group). The exclusion criteria were significant coronal deformity, flexion contracture, or the need for stem and/or augmentation. The closure time for the capsule and that for the subcutaneous layer were registered separately. Intraoperative incidences were recorded. The follow-up was up to 1 month, during which the range of motion (ROM), superficial or deep infection, and wound dehiscence were assessed. There was a significant reduction in the capsule layer (27 seconds; p = 0.02) and global time closure (51 seconds; p = 0.01) in the Q-group. No differences were found in the subcutaneous layer (24 seconds; p = 0.055). There were more intraoperative suture breakages in the Q-group, mainly in the subcutaneous layer (p < 0.001). No differences in terms of dehiscence, infection, and ROM were observed at the 1-month follow-up. BBSs allow for slightly faster wound closure than Vicryl during a TKA. However, the differences observed have minimal clinical repercussions. Moreover, no differences in the infection rate (deep or superficial), dehiscence, or ROM were found.