An in vitro analysis of medial structures and a medial soft tissue reconstruction in a constrained condylar total knee arthroplasty.
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ABSTRACT: The aim of this study was to quantify the medial soft tissue contributions to stability following constrained condylar (CC) total knee arthroplasty (TKA) and determine whether a medial reconstruction could restore stability to a soft tissue-deficient, CC-TKA knee.Eight cadaveric knees were mounted in a robotic system and tested at 0°, 30°, 60°, and 90° of flexion with ±50 N anterior-posterior force, ±8 Nm varus-valgus, and ±5 Nm internal-external torque. The deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) were transected and their relative contributions to stabilising the applied loads were quantified. After complete medial soft tissue transection, a reconstruction using a semitendinosus tendon graft was performed, and the effect on kinematic behaviour under equivocal conditions was measured.In the CC-TKA knee, the sMCL was the major medial restraint in anterior drawer, internal-external, and valgus rotation. No significant differences were found between the rotational laxities of the reconstructed knee to the pre-deficient state for the arc of motion examined. The relative contribution of the reconstruction was higher in valgus rotation at 60° than the sMCL; otherwise, the contribution of the reconstruction was similar to that of the sMCL.There is contention whether a CC-TKA can function with medial deficiency or more constraint is required. This work has shown that a CC-TKA may not provide enough stability with an absent sMCL. However, in such cases, combining the CC-TKA with a medial soft tissue reconstruction may be considered as an alternative to a hinged implant.
Project description:There is debate in the literature whether rotating hinge knee (RHK) or constrained condylar knee (CCK) prostheses lead to better clinical outcomes and survival rates in patients undergoing revision total knee arthroplasty (RTKA). The purpose of this meta-analysis is to compare the survivorship and clinical outcomes of RHK and CCK prostheses. In this meta-analysis, we reviewed studies that evaluated pain and function scores, range of motion (ROM), complications, and survival rates in patients treated with RHK or CCK with short-term (<5 years) or midterm (5-10 years) follow-up. The survivorship was considered as the time to additional surgical intervention such as removal or revision of the components. A total of 12 studies (one randomized study and 11 non-randomized studies) met the inclusion criteria and were analyzed in detail. The proportion of the knees in which short-term (<5 years) survival rates (RHK, 83/95; CCK, 111/148; odds ratio [OR] 0.52; 95% CI, 0.24-1.11; P = 0.09) and midterm (5-10 years) survival rates (RHK, 104/128; CCK, 196/234; OR 1.05; 95% CI, 0.56-1.97; P = 0.88) were evaluated did not differ significantly between RHK and CCK prostheses. In addition, there were no significant differences in ROM (95% CI: -0.40 to 9.93; P = 0.07) and complication rates (95% CI: 0.66 to 2.49; P = 0.46). In contrast, CCK groups reported significantly better pain score (95% CI: 0.50 to 2.73; P = 0.005) and function score (95% CI: 0.01 to 2.00; P = 0.05) than RHK groups. This meta-analysis revealed that 87.4% of RHK and 75.0% of CCK prostheses survive at short-term (<5 years), while 81.3% of RHK and 83.8% of CCK prostheses survive at midterm (5-10 years). The differences in standardized mean pain and function scores we detected were likely to be imperceptible to patients and almost certainly below the minimum clinically important level, despite a significant difference in both groups. Based on the findings of the current meta-analysis, RHK prostheses continue to be an option in complex RTKA with reasonable midterm survivorship.
Project description:PurposeTo investigate if postoperative clinical outcomes correlate with specific kinematic patterns after total knee arthroplasty (TKA) surgery. The hypothesis was that the group of patients with higher clinical outcomes would have shown postoperative medial pivot kinematics, while the group of patients with lower clinical outcomes would have not.Methods52 patients undergoing TKA surgery were prospectively evaluated at least a year of follow-up (13.5 ± 6.8 months) through clinical and functional Knee Society Score (KSS), and kinematically through dynamic radiostereometric analysis (RSA) during a sit-to-stand motor task. Patients received posterior-stabilized TKA design. Based on the result of the KSS, patients were divided into two groups: "KSS > 70 group", patients with a good-to-excellent score (93.1 ± 6.8 points, n = 44); "KSS < 70 group", patients with a fair-to-poor score (53.3 ± 18.3 points, n = 8). The anteroposterior (AP) low point (lowest femorotibial contact points) translation of medial and lateral femoral compartments was compared through Student's t test (p < 0.05).ResultsLow point AP translation of the medial compartment was significantly lower (p < 0.05) than the lateral one in both the KSS > 70 (6.1 mm ± 4.4 mm vs 10.7 mm ± 4.6 mm) and the KSS < 70 groups (2.7 mm ± 3.5 mm vs 11.0 mm ± 5.6 mm). Furthermore, the AP translation of the lateral femoral compartment was not significantly different (p > 0.05) between the two groups, while the AP translation of the medial femoral compartment was significantly higher for the KSS > 70 group (p = 0.0442).ConclusionIn the group of patients with a postoperative KSS < 70, the medial compartment translation was almost one-fourth of the lateral one. Surgeons should be aware that an over-constrained kinematic of the medial compartment might lead to lower clinical outcomes.Level of evidenceII.
Project description:BackgroundThe aim of this study was to describe outcomes of patients who had undergone medial patellofemoral ligament reconstruction (MPFLr) to treat patellofemoral instability (PFI) following total knee arthroplasty (TKA).Material and methodsThis is a retrospective case series of consecutive patients treated for PFI after TKA. Patients were included if they had radiographic documentation of patella dislocation or subluxation and component position was adequate. MPFLr was performed using a quadriceps tendon autograft. The graft was fixed with either an interference or additional suspensory fixation. A tibial tubercle osteotomy was performed in select indications. Patients were assessed with Kujala and International Knee Score (IKS) at a minimum 12-month follow-up and radiographically with plain radiographs.ResultsA total of 22 patients (23 procedures) were included. The mean follow-up period was 38 months (range 12-72). Average preoperative femoral component rotation on computed tomography was 0.10° external rotation (range 3° internal rotation to 3° external rotation). All patients had improved clinical and radiographic outcomes postoperatively. At the last follow-up, the mean IKS knee score was 77.6 ± 13.1, mean IKS function score was 75.2 ± 23.3, and mean Kujala score was 60.2/100 ± 10.9. There was 1 mechanical failure, which occurred following MPFLr with interference fixation. There were 6 complications (28.1%) postoperatively. Patients receiving double fixation of the MPFLr graft had higher clinical and radiographic scores; however, this difference was not statistically significant. MPFLr had a patella-lowering effect, 0.97 preoperatively to 0.74 postoperatively (P = .069).ConclusionMPFLr in appropriately selected patients is a satisfactory option to treat PFI following TKA.
Project description:PurposeStability in the sagittal plane, particularly regarding anterior cruciate ligament compensation, and postoperative functionality and satisfaction remain issues in total knee arthroplasty. Therefore, this prospective study compared the clinical outcomes between medial-pivot-based and posterior-stabilised total knee arthroplasty based on anterior translation and clinical scores.MethodsTo assess outcomes of total knee arthroplasty for varus osteoarthritis, the anterior translation distance of the tibia relative to the femur was measured at 30 and 60° of flexion using a KS measure Arthrometer at 6 months postoperatively. The 2011 Knee Society Score, Forgotten Joint Score, visual analogue scale for pain, and range of motion were assessed at 6 months and 1 year postoperatively. The correlations among each score, anterior translation distance, range of motion, and visual analogue scale score for pain were investigated.ResultsThe medial-pivot and posterior-stabilised groups comprised 70 and 51 patients, respectively. The medial-pivot group exhibited a significantly shorter anterior translation distance at 60° flexion than the posterior-stabilised group. Furthermore, the medial-pivot group achieved significantly better outcomes regarding the visual analogue scale for pain, 2011 Knee Society Score, and Forgotten Joint Score than the posterior-stabilised group. A significant negative correlation was observed between the anterior translation distance and the function score of the 2011 Knee Society Score, whereas a significant positive correlation was found between the anterior translation distance and flexion angle, and between the extension angle and score of the Forgotten Joint Score or 2011 Knee Society Score. Significant negative correlations were also found between the pain visual analogue scale and both the 2011 Knee Society Score and Forgotten Joint Score.ConclusionIn total knee arthroplasty for osteoarthritis, the medial-pivot group displayed a shorter anterior translation distance than the posterior-stabilised group at 6 months postoperatively. The visual analogue scale score for pain was also significantly lower in the medial-pivot group than that in the posterior-stabilised group at both 6 months and 1 year postoperatively. Because a correlation was observed between the anterior translation distance and the function score, medial-pivot-based total knee arthroplasty was considered to significantly improve postoperative function compared to posterior-stabilised total knee arthroplasty.
Project description:Medial collateral ligament (MCL) injuries are typically managed non-operatively, with high rates of clinical success. However, patients who present with medial knee laxity with valgus stress testing of a fully extended knee, anteromedial rotatory instability, associated tibial plateau fracture, or multiligament injury or those who continue to be symptomatic after non-operative treatment may benefit from surgical intervention. Patients with a history of total knee arthroplasty who suffer MCL and posterior oblique ligament (POL) injuries represent a challenging patient population and often require surgical attention. In this Technical Note, we describe the preoperative assessment, decision making, and surgical technique for anatomic reconstruction of the superficial MCL and POL with an Achilles allograft in young, active patients with medial-sided knee injuries after total knee arthroplasty.
Project description:BackgroundClinical outcomes of kinematically aligned total knee arthroplasty (KA-TKA) have been reported as comparable or superior to those of mechanically aligned TKA (MA-TKA). However, cruciate-retaining prostheses have mostly been used for KA-TKA. This study used medial pivot knee prostheses for KA-TKA, and knee kinematics after KA-TKA were assessed and compared with those after MA-TKA.MethodsThirteen knees in 9 patients undergoing primary TKA (8 KAs, 5 MAs) were subjected to two-dimensional (2D) to three-dimensional (3D) registration analysis at 1 year postoperatively. Each patient performed weight-bearing activities, and movements were recorded as intermittent digital radiographic images. Three-dimensional implant positions during activities were analyzed for anterior-posterior translation in the sagittal plane, condylar liftoff and mediolateral translation in the coronal plane, and femoral rotation in the axial plane.ResultsPosterior translation of the lateral femoral condyle from 0° to 100° was larger in KA-TKA than in MA-TKA (P = .006). The degrees of condylar liftoff and mediolateral translation were comparable between TKAs. Total external rotation of the femoral component relative to tibial component was significantly greater for KA-TKA (7.7 ± 5.2°) than for MA-TKA (1.3 ± 3.3°; P = .03). The kinematic path of the femoral component revealed greater medial pivoting motion in KA-TKA than in MA-TKA.ConclusionsKA-TKA using a medial pivot knee prosthesis successfully reproduced the medial pivot pattern and achieved larger femoral external rotation relative to the tibia than MA-TKA. KA-TKA was able to maximize the primary concept of the medial pivot knee prosthesis.
Project description:Chronic patellar dislocation in the setting of severe knee osteoarthritis is a rare clinical problem. Surgical management often consists of total knee arthroplasty combined with realignment of the extensor mechanism. Several techniques have been described to anatomically restore the extensor apparatus, and literature regarding this topic consists mainly of case reports. We describe a technique using combined medial patellofemoral ligament reconstruction using allograft tissue and total knee arthroplasty with patellar resurfacing for the treatment of chronic patellar dislocation and severe osteoarthritis.
Project description:Ischaemic preconditioning is a method of protecting tissue against ischaemia-reperfusion injury. It is an innate protective mechanism that increases a tissue's tolerance to prolonged ischaemia when it is first subjected to short burst of ischaemia and reperfusion. It is thought to provide this protection by increasing the tissue's tolerance to ischaemia, therby reducing oxidative stress, inflammation and apoptosis in the preconditioned tissue. We used microarrays to investigate the genomic response induced by ischaemic preconditioning in muscle biopsies taken from the operative leg of total knee arthroplasty patients in order to gain insight into the ischaemic preconditioning mechanism. Patients undergoing primary knee arthroplasty were randomised to control and treatment (ischaemic preconditioning) groups. Patients in the treatment group received a preconditioning stimulus immediately prior to surgery. The ischaemic preconditioning stimulus consisted of three five-minute periods of tourniquet insufflation on the lower operative limb, interrupted by five minute periods of reperfusion. All patients had a tourniquet applied to the lower limb after the administration of spinal anaesthesia, as per normal protocol for knee arthroplasty surgery. Muscle biopsies were taken from the quadriceps muscle of the operative knee at the immediate onset of surgery (T0) and at 1 hour into surgery (T1). Total RNA was extracted from biospies of four control and four treatment patients and hybridised to the Affymetrix Human U133 2.0 chip.
Project description:BackgroundInterest in bicompartmental knee arthroplasty (BKA) for the treatment of medial patellofemoral osteoarthritis (MPFOA) has grown in recent years because BKA offers a bone and ligament-preserving alternative to total knee arthroplasty (TKA). BKA only resurfaces the diseased compartments, while preserving proprioception and native knee kinematics. Therefore, the objective of this study is to assess knee function, perioperative morbidity, and implant survivability in patients undergoing BKA vs TKA for MPFOA.MethodsThe databases MEDLINE, PUBMED, and EMBASE were systematically searched. Randomized controlled trials and nonrandomized comparative studies comparing BKA with TKA for the treatment of MPFOA were included for further analysis. The primary outcome of interest was knee function. Secondary outcomes included range of movement, operation length, intraoperative blood loss, hospital length of stay, postoperative complications, and rate of revision length. The quality of evidence was evaluated using the GRADE approach. Meta-analysis was performed by pooling the results of the selected studies when possible.ResultsSix studies were selected for inclusion (4 prospective studies and 2 retrospective cohort studies). In total, 274 patients and 277 knees were included for analysis. There were no significant differences between the 2 groups at any time points in terms of knee function, length of stay, complication rate, or revision rate, when monolithic BKA designs were controlled for. BKA did result in significantly decreased intraoperative blood loss, at the expense of increased operative length compared with TKA.ConclusionsThe use of modular BKA for MPFOA is comparable with TKA in terms of short-term function, complication rate, and revision rate. BKA reduces intraoperative blood losses, but it is also more technically demanding, resulting in increased operation length. The use of modular BKA has acceptable short-term outcomes, but more long-term data are needed before it can be recommended for routine use in the treatment of MPFOA. The selection of modular BKA should be determined on a patient-specific basis. Currently, there is no evidence to suggest the use of monolithic BKA designs because of their high revision and failure rate.
Project description:IntroductionDislocation of the knee after primary total knee arthroplasty is rare in a posterior stabilized knee and extremely rare in a constrained total knee arthroplasty. Constrained total knee prostheses are used for severe knee deformities and to provide stable and mobile knees.Presentation of caseIn this case, we describe a dislocation of a primary constrained total knee arthroplasty using the Genesis II (Smith & Nephew, Memphis Tennessee, USA) prosthesis. Without any significant trauma, the constrained insert dislocated fifteen months after surgery and revision surgery with a bigger insert was needed. Surgical error may have been the cause of dislocation, but we were unable to establish a clear reason behind this dislocation.DiscussionKnee dislocation after TKA is rare but easily overlooked and can lead to serious complications and permanent disability. This system should provide stable and mobile knees to correct collateral ligament laxity.ConclusionHere, we report the first case, to our knowledge, of dislocation with a constrained prosthesis without any history of trauma.