Ligament Balancing and Constraint in Revision Total Knee Arthroplasty

Ligament balancing in revision knee arthroplasty is crucial to the success of the procedure. The medial collateral ligament and lateral ligament complex are the primary ligamentous structures that provide stability. Revisions can be performed with nonconstrained cruciate-retaining, posterior cruciate substituting, or anterior-stabilized/ultracongruent inserts when there are symmetrical flexion/extension gaps and intact collateral ligaments. When the collateral ligaments are insufficient either due to attenuation or incompetence from bone loss, a more constrained knee system is needed. Constrained condylar knees provide increased stability to both varus/valgus and rotation forces with a nonlinked construct. This increased constraint, however, does lead to increased stress at the implant–bone interface which requires more robust metaphyseal fixation. In cases of significant soft tissue disruption, severe flexion/extension gap mismatch or extensor mechanism disruption, a rotating hinge knee is needed to restore stability. Advances in revision implant design have led to improved outcomes and longer survivorship then earlier iterations of these implants. Surgeons should always strive to use the least constraint needed to achieve stability but must have a low threshold to increase constraint when ligament integrity is compromised.

Ligament Balancing in Severe Osteoarthritis Knee with Large Cyst and Bursae - A Rare Case Report with Review of Literature

The main indication of total knee replacement (TKR) is pain and restricted range of motion of the knee. The key to a successful total knee replacement is correct alignment in flexion and extension. Here we report a case of TKR in severe osteoarthritis (O / A) knee with a large cyst on the medial side of the knee, resulting in the problem of ligament balancing and management with help of an Arthrex Internal brace. Proper diagnosis and treatment plan help to overcome the challenging cases of varus knee. The indication of total knee replacement is pain and restricted range of motion of the knee. Several authors have reported successful outcomes on patient satisfaction in the follow-up of almost ten to fifteen years. 1 Additionally, the results of surgery are satisfactiry with good implant survival. 2 But some patients indeed have poor results and some may require revision surgery in a short duration. The key to a successful total knee replacement is correct alignment and stability in flexion and extension.3 The ligament after balancing of the correctly aligned knee must consider the function of the resected ligaments in flexion and extension, because in TKR both anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) are usually sacrificed. In other words, total knee replacement is a soft tissue surgery in which bone is replaced. In the varus knee, medial side structures are tight and compensatory laxity on the lateral side. So knee stability should be managed by the remaining ligamentous structures that are both medial and lateral collateral and capsular ligaments. 4 The gap technique is the gold standard for ligament balancing in total knee replacement. 5 That is the execution of equal medial and lateral gaps as well as balanced flexion and extension gaps. This is usually obtained by medial side release in varus knee as the medial side is contracted and lateral side release in valgus knee accordingly. Here we report a case of TKR in severe osteoarthritis knee with a large cyst on the medial side of the knee, resulting in the problem of ligament balancing and management.

Can a well balanced soft tissue envelope speed up the postoperative treatment and improve clinical follow-up? A control - pilot study using a dynamic ligament balancing device based on functional stability

IntroductionWorldwide, the number of TKA implants is increasing. Even if registry demonstrate that TKA as high satisfaction rate, there are still between 15 and 20% dissatisfied patients.Materials and methodsThe proper soft tissue balancing is one of the most discussed topics of the last years. We initiated a study using an electronic device („dynamic ligament balancing sensorplate“) to compare the benefit of the measurement of ligament tension, space and position in comparison to a conventional surgical procedure. Beside that, we followed the concept of functional stability, which tells us, that a tension of 40N in total is sufficient to reach proper (functional) joint stability.This control pilot study was set up as a single surgeon, single center study and consists of 25 patients treated by the use of the sensorplate and a control group of 25 patients, treated in a conventional setup.We used the following scores for evaluation: OKS, AKSS and FJS, preoperatively and during the FU examinations (postoperative, 6 weeks, 3 months, 6 months and 1 year)Beside scoring, clinical examination and routine x-ray we performed an EMG testing at all FU dates.ResultsThe study was performed between January 2017 and May 2019. The mean age of the patients was in average 72 years, 66 % female and 34 % male. After 1 year, results demonstrate a clear difference in the development of the postoperative situation between dynamic balanced TKA and the control one.So, the use of such electronic device improving the soft tissue envelope stability, enable a significantly better patient FU, especially in terms of OKSDiscussionThe DLB system is a new option to value and improve the soft tissue envelope tensioning during the surgical TKA operation. It allows to measure ligament tension, slope and joint space all over the entire ROM.ConclusionUsing an electronic device for measurement is an advanced option to improve patient satisfaction after tka. Like the studies of other existing devices have shown before there is a massive change in the kinematic behaviour of the muscular abilities by using these tools for a better soft tissue balance. The DLB system is another option by showing 3 different measurement results (tension, distance and joint angle) to adapt the implantation procedure to the individual situation of the patient.

Objective quantification of ligament balancing using VERASENSE in measured resection and modified gap balance total knee arthroplasty

Aims To evaluate: (1) objective quantification of ligament balancing in total knee arthroplasty, (2) types and effectiveness of additional procedures to compartment pressure, and (3) change of pressure values in both compartment throughout the range of motion in total knee arthroplasty.Methods Eighty-four patients underwent total knee arthroplasty (TKA) using VERASENSE Knee System. TKA was performed by two techniques. Compartment pressure was recorded through the range of motion (ROM) initially, after each additional procedure, and after final implantation. Balanced knees were defined as when the compartment pressure difference was less than 15 pounds.Results Thirty patients (35.7%) showed “balanced” knee on initial pressure measurement. Modified gap balancing TKAs showed significantly higher proportion of “balanced” knee than measured-resection TKAs (P = 0.004). Both medial and lateral compartment pressure were generally decreased on both TKA methods. Linear correlation showed statistically significant through ROM on both compartment. Total 66 additional ligament balancing procedures were performed.Conclusion Using the objective orthosensor, we were able to obtain 94% of well-balanced total knee arthroplasty finally. Furthermore, acquired objective data can lead to proper ligament balancing for both experienced and young surgeons and consequently reduce the complications associate with soft tissue imbalance in the future.

Does the sequential addition of accelerometer-based navigation and sensor-guided ligament balancing improve outcomes in TKA?

Aims A significant percentage of patients remain dissatisfied after total knee arthroplasty (TKA). The aim of this study was to determine whether the sequential addition of accelerometer-based navigation for femoral component preparation and sensor-guided ligament balancing improved complication rates, radiological alignment, or patient-reported outcomes (PROMs) compared with a historical control group using conventional instrumentation. Methods This retrospective cohort study included 371 TKAs performed by a single surgeon sequentially. A historical control group, with the use of intramedullary guides for distal femoral resection and surgeon-guided ligament balancing, was compared with a group using accelerometer-based navigation for distal femoral resection and surgeon-guided balancing (group 1), and one using navigated femoral resection and sensor-guided balancing (group 2). Primary outcome measures were Patient-Reported Outcomes Measurement Information System (PROMIS) and Knee injury and Osteoarthritis Outcome (KOOS) scores measured preoperatively and at six weeks and 12 months postoperatively. The position of the components and the mechanical axis of the limb were measured postoperatively. The postoperative range of motion (ROM), haematocrit change, and complications were also recorded. Results There were 194 patients in the control group, 103 in group 1, and 74 in group 2. There were no significant differences in baseline demographics between the groups. Patients in group 2 had significantly higher baseline mental health subscores than control and group 1 patients (53.2 vs 50.2 vs 50.2, p = 0.041). There were no significant differences in any PROMs at six weeks or 12 months postoperatively (p > 0.05). There was no difference in the rate of manipulation under anaesthesia (MUA), complication rates, postoperative ROM, or blood loss. There were fewer mechanical axis outliers in groups 1 and 2 (25.2%, 14.9% respectively) versus control (28.4%), but this was not statistically significant (p = 0.10). Conclusion The sequential addition of navigation of the distal femoral cut and sensor-guided ligament balancing did not improve short-term PROMs, radiological outcomes, or complication rates compared with conventional techniques. The costs of these added technologies may not be justified. Cite this article: Bone Joint J 2020;102-B(6 Supple A):24–30.