PCL-substituting Total Knee Arthroplasty Research Articles

Midterm Outcomes of Posterior Cruciate Ligament Substituting Total Knee Arthroplasty

Objective: In the present study, it is aimed to retrospectively investigate and present the midterm results of the cases with posterior cruciate ligament (PCL) substituting total knee arthroplasty. Materials and Methods: In this study, we included a total of 61 patients with 80 knees who underwent PCL-substituting total knee arthroplasty between July 2006 and June 2012. Results: 52 patients were female and 9 were male. The mean age of patients was 65.4 (42-85) years and the mean follow up period was 32.6 (12-72) months. Patients were evaluated according to the American Knee Society Score for knee score and knee functional score. Radiological evaluation was performed according to Total Knee Arthroplasty Radiological Evaluation criteria. Knee score was 38-71 (mean 43.7) prior to the surgery and 78-100 (mean 95) subsequently. 69 knee (86,25%) had perfect knee scores and 11 knee (13.75%) had good scores. Functional score was 10-60 (mean 35.08) prior to the surgery and 60-100 (mean 82.2) subsequently. In the evaluation according to the functional knee score, we obtained perfect results in 45 knee (56.25%) and good results in 29 knees (36.25%) and moderate results in 6 knees (7.5%). Patients had a mean 9.7o varus (8o valgus – 20o varus) prior to the surgery and mean 4.75o valgus (2o varus – 10o valgus) alignment was obtained subsequently to surgery. In 1 case revision arthroplasty was performed due to late deep infection. In 1 case insert replacement was performed due to insert fracture due to trauma. As a result of our PCL substituting total knee arthroplasty applications, we obtained 86.25%perfect knee score and 56.25%perfect functional score. Conclusion: PCL substituting total knee arthroplasty is a favorable orthopedic surgical intervention when preformed with adequate preoperative preparations and cautious surgical techniques with appropriate patient choice.

Mid-term outcomes of posterior stabilized total knee arthroplasty in severe osteoarthritis

Aim: The purpose of this study was to reveal mid-term outcomes by retrospectively investigating patients who underwent total knee arthroplasty with a posterior stabilized design.
 Material and methods: The study included a total of 68 knees of 52 patients with completed follow-up data who underwent PCL substituting (PS) total knee arthroplasty due to a diagnosis of primary or secondary osteoarthritis. The 52 patients comprised 45 (86.5%) females and 7 (13.5%) males with a mean age of 65.2±9.32 years (range, 30-82 years). The American Knee Society criteria were adopted for assessment of patient knee scores and functional knee scores. The Total Knee Prosthesis Radiological Evaluation criteria were applied for radiological evaluation of the patients.
 Results: The mean follow-up period of the patients was 32.1 ± 9.85 months (range: 18-60 months) and the Knee Society Scores (KSS) were 41.5 (range: 26 - 58) preoperatively, and 84.3 (range: 51 - 97) postoperatively. The mean preoperative and postoperative range of motion was 88.2º (range: 60º - 100º), and 106.7º (range: 90º - 120º), respectively. Two-stage revision surgery was applied to one patient due to deep infection. No cases of aseptic loosening were observed. Implant survivorship, and excellent and good results according to the functional knee score were reported as 98.8%, 41.1%, and 32.3%, respectively.
 Conclusion: Positive patient outcomes were obtained with the use of PS total knee arthroplasty in patients with severe osteoarthritis and there was no evidence of loss in mid-term follow-up.

Influence of posterior tibial slope on knee flexion in posterior stabilized fixed bearing primary total knee arthroplasty

<p class="abstract"><strong>Background:</strong> The goal of total knee arthroplasty (TKA) is to relieve pain and maintain stable range of motion (ROM) for day to day activities. Among the various factors, posterior tibial slope slope (PTS) may play an important role in achieving good postoperative knee flexion. Our study aims to know the effectiveness of PTS on the ROM of the knee in a posterior cruciate ligament (PCL)-substituting TKA.</p><p class="abstract"><strong>Methods:</strong> A total of 125 unilateral PCL-substituting TKA’s were included in the study. Based on postoperative PTA which was measured on lateral radiograph, patients were divided into 3 groups, Group A (PTS of ≤2) comprise of 24 patients. Group B consists of 91 patients (PTS of 3 to 7). Group C includes 10 patients (PTS of 8 or more). Functional outcome was measured by using knee society score (KSS) and Western Ontario and McMaster Universities osteoarthritis index (WOMAC) which were evaluated preoperatively and at 18months post operatively.<strong></strong></p><p class="abstract"><strong>Results:</strong> Mean postop ROM was 92.91 ± 10.632; 107.24±10.905; 107.49±13.944 in group A, B, C respectively which was significantly related to mean postop PTS (0.74; 5.62; 9.87 in group A, B, C respectively) (P<0.05). Functional outcome was measured by KSS and WOMAC which showed no significant difference pre and postoperatively.</p><p class="abstract"><strong>Conclusions:</strong> The results of our study validate the hypothesis that a positive correlation exists between the postoperative flexion and PTS in the PCL-substituting TKA, an increase in PTS can lead to a greater degree of the knee flexion for every extra degree of PTS.</p><p> </p>

Comparison of the Clinical Results of Patients who Underwent PCL-retaining and PCL-substituting Total Knee Arthroplasty

Objective: This study aimed to retrospectively evaluate patients undergoing total knee arthroplasty (TKA) and compare clinical results of patients with posterior cruciate ligament (PCL)-retaining and PCL-substituting TKA. Method: The clinical results of 60 patients who underwent TKA (30 PCL retaining and 30 PCL substituting) at Duzce University Faculty of Medicine Hospital between September 2014 and September 2016 were evaluated and compared. The clinical results were evaluated using knee scores and knee functional scores according to the American Knee Society Criteria. Results: The mean postoperative flexion angles were 110.33° ± 5.71° (100°–120°) in the PCL-substituting group and 102.50° ± 5.69° (90°–110°) in the PCL-retaining group, the postoperative knee scores were 90.20 ± 5.16 and 84.07 ± 5.87, respectively, and postoperative knee functional scores were 80.60 ± 7.86 and 78.17 ± 7.25, respectively. Knee scores were significantly different between the groups (P < 0.001). There was no significant difference between the groups in terms of knee functional scores. Conclusion: Compared with the literature, knee scores of the PCL-substituting group yielded significant results, whereas the knee functional scores were similar to those of the PCL-retaining group. The results reported here indicate that clinical outcomes and survival are not different for either surgical option, and it is possible to achieve good results in both groups when appropriate soft tissue balance is achieved.

Interactive effect of femoral posterior condylar offset and tibial posterior slope on knee flexion in posterior cruciate ligament-substituting total knee arthroplasty

BackgroundThis work aimed to evaluate the changes in the femoral posterior condylar offset (PCO) and tibial slope after posterior cruciate ligament (PCL)-substituting total knee arthroplasty (TKA), and to address the presence of any interactive effect between the two on knee flexion. MethodsFifty-two PCL-substituting TKAs were performed using a posterior referencing system. Three-dimensional reconstructed computed tomographic (CT) images were used to evaluate PCO and tibial slope before and after arthroplasty. Range of motion and clinical scores were evaluated at a mean of 3.1years postoperatively. Multivariate linear model with interaction terms was used to evaluate and compare the relationships among changes in PCO, tibial slope, and postoperative knee flexion angles. ResultsThe degree of change in PCO was greater in the lateral condyle than in the medial condyle (3.1±2.5mm and −0.5±2.8mm, respectively). Postoperative medial and lateral tibial slopes were 1.4°±1.8 and 1.4°±2.0, respectively. The mean degree of postoperative knee flexion was 125°. Analysis with interaction terms and covariate adjustment demonstrated that medial PCO and tibial slope were significantly related to knee flexion with interactive effect (P=0.011). In cases with <3° posterior tibial slope, the postoperative PCO was positively correlated to the degree of knee flexion angle. However, in cases with >3° tibial slope, PCO was negatively correlated to knee flexion. ConclusionMedial femoral PCO and tibial slope showed interactive effect on knee flexion after PCL-substituting TKAs. Reconstitution of the proper PCO and avoiding excessive tibial slope may be necessary.

Changes in femoral posterior condylar offset and knee flexion after PCL-substituting total knee arthroplasty: comparison of anterior and posterior referencing systems.

Anterior referencing and posterior referencing are two major techniques for positioning femoral components and balancing the sagittal plane during total knee arthroplasty (TKA). The purpose of this study was to evaluate the changes in medial and lateral posterior condylar offset (PCO) after bilateral TKA using anterior referencing (AR) or posterior referencing (PR) systems and compare the effect of the PCO changes on knee flexion. Twenty female patients (mean age, 68.6years) underwent bilateral TKA using the AR technique in one knee and the PR technique in the contralateral knee. Three-dimensional reconstructed computed tomographic images from the sagittal plane were used to evaluate PCO before and after arthroplasty. Knee Society scores and range of motion were evaluated postoperatively at a mean of 2.9years. Postoperative medial and lateral PCOs were significantly greater (p<0.001 and p=0.048, respectively) in the AR group (30.9±2.2 and 29.1±1.5mm, respectively) than those in the PR group (29.1±2.7 and 27.3±2.3mm, respectively). In addition, the degree of change in the PCO after TKA was greater in the AR group than in the PR group. On the final follow-up, no differences in the degree of knee flexion were observed between the two groups (124.7° for AR and 124.5° for PR). Knee Society scores were similar in the two groups both preoperatively and postoperatively. On the final follow-up, individual changes in the medial and lateral PCO were not associated with changes in the knee flexion angle. Restoration of PCO after TKA was more accurate with the PR technique than with the AR technique. However, the postoperative differences in PCO showed no correlation with changes in knee flexion 2years after PCL-substituting TKA. Therapeutic study, Level I.

Retention of the posterior cruciate ligament does not affect femoral rotational alignment in TKA using a gap-balance technique.

PurposePrevious studies have evaluated the ability of the gap technique to achieve accurate rotational placement in both posterior cruciate ligament (PCL)-retaining and PCL-substituting total knee arthroplasty (TKA). The purpose of the present study was to determine (1) the accuracy of this technique in degrees and (2) whether retention of the PCL affects the rotational alignment of the femoral component relative to the transepicondylar axis during TKA. The hypothesis of this study was that retention of the PCL does not affect the femoral rotational alignment in TKA using a gap-balancing technique because both procedures are reported to have good long-term clinical outcomes.MethodsThe femoral rotation angle (FRA) relative to the transepicondylar axis was examined in 206 patients who underwent primary TKA using either PCL-retaining (104 knees) or PCL-substituting (102 knees) prostheses to determine the effect of PCL retention on FRA. Quantitative three-dimensional computed tomography was used to assess the FRA in both groups. All values are expressed as median (25th percentile, 75th percentile).ResultsPostoperative FRA in the PCL-retaining group was −1.1° (−2.8°, 2.2°) and in the PCL-substituting group was −0.1° (−2.5°, 2.8°). The groups were not statistically different. One outlier was found in the PCL-retaining group, and none was found in the PCL-substituting group.ConclusionsThe gap technique reliably allows accurate rotational alignment of the femoral component during TKA despite the retention of the PCL.Level of evidenceTherapeutic study, Level II.

The Surgeon's Role in Relative Success of PCL-Retaining and PCL-Substituting Total Knee Arthroplasty.

BackgroundThe orthopedic literature has not shown a universal and replicated difference, outside of flexion, in clinical results between posterior cruciate ligament retention and posterior cruciate ligament substitution in total knee arthroplasty.Questions/PurposesThis study was performed to compare the restoration of flexion and knee function in a large series of cruciate-retaining and cruciate-substituting total knee arthroplasties (TKRs). In addition, we aimed to study how other variables, such as those unique to each surgeon, may have affected the results.Patients and MethodsThe current study evaluated 8,607 total knee arthroplasties in 5,594 patients performed by six surgeons, each using one of four prosthesis designs (two posterior cruciate ligament retaining, two posterior cruciate ligament substituting). Knees were compared at the level of cruciate-retaining and cruciate-substituting knees, at the level of the four prostheses, and at the level of surgeon-implant combinations. Least squared means scores were obtained through multiple linear regression, analysis of variance, and the maximum likelihood method.ResultsAt the level of posterior cruciate ligament treatment, posterior cruciate ligament substitution as a whole showed 3.2° greater flexion than posterior cruciate ligament retention. At the prosthesis level, cruciate-substituting models provided greater flexion and cruciate-retaining models provided higher function scores. In the surgeon-implant combinations, surgeons provided mixed results that often did not reflect findings from other levels; one surgeon's use of a posterior cruciate ligament retaining prosthesis achieved 14.7° greater flexion than the surgeon's use of a corresponding posterior cruciate ligament substituting design.ConclusionsPosterior cruciate ligament treatment is confounded by other variables, including the operating surgeon. The arthroplasty surgeon should choose a prosthesis based, not only on outside results, but also on personal experience and comfort.Electronic supplementary materialThe online version of this article (doi:10.1007/s11420-014-9389-5) contains supplementary material, which is available to authorized users.

The accuracy of intramedullary tibial guide of sagittal alignment of PCL-substituting total knee arthroplasty

Experimental and clinical studies on the accuracy of the intramedullary alignment method have produced different results, and few have addressed accuracy in the sagittal plane. Reported deviations are not only attributable to the alignment method but also to radiological errors. The purpose of this study was to evaluate the accuracy of the intramedullary alignment method in the sagittal plane using computed tomography (CT) and 3-dimensional imaging software. Thirty-one TKAs were performed using an intramedullary alignment method involving the insertion of a long 8-mm diameter rod into the medullary canal to the distal metaphysis of the tibia. All alignment instruments were set to achieve an ideal varus/valgus angle of 0° in the coronal plane and a tibial slope of 0° in the sagittal plane. The accuracy of the intramedullary alignment system was assessed by measuring the coronal tibial component angle and sagittal tibial slope angles, i.e., angles between the tibial anatomical axis and the tangent to the medial and lateral tibial plateau or the cut-surface. The mean coronal tibial component angle was 88.5°±1.2° and the mean tibial component slope in the sagittal plane was 1.6°±1.2° without anterior slope. Our intramedullary tibial alignment method, which involves passing an 8-mm diameter long rod through the tibial shaft isthmus, showed good accuracy (less than 3 degrees of variation and no anterior slope) in the sagittal plane in neutral or varus knees.

Gap Balancing versus Measured Resection Technique for Total Knee Arthroplasty

Multiple differing surgical techniques are currently utilized to perform total knee arthroplasty (TKA). We compared knee arthroplasties performed using either a measured resection or gap balancing technique to determine if either operative technique provides superior coronal plane stability as measured by assessment of the incidence and magnitude of femoral condylar lift-off. We performed 40 TKA using a measured resection technique (20 PCL-retaining and 20 PCL-substituting) and 20 PCL-substituting TKA were implanted using gap balancing. All subjects were analyzed fluoroscopically while performing a deep knee bend. The incidence of coronal instability (femoral condylar lift-off) was then determined using a 3-D model fitting technique. The incidence of lift-off greater than 0.75 mm was 80% (maximum, 2.9 mm) and 70% (maximum, 2.5 mm) for the PCL-retaining and substituting TKA groups performed using measured resection versus 35% (maximum, 0.88 mm) for the gap-balanced group. Lift-off greater than 1 mm occurred in 60% and 45% of the PCL-retaining and -substituting TKA using measured resection versus none in the gap-balanced group. Rotation of the femoral component using a gap balancing technique resulted in better coronal stability which we suggest will improve functional performance and reduce polyethylene wear.

Total knee arthroplasty following failed high tibial osteotomy: mid-term comparison of posterior cruciate-retaining versus posterior stabilized prosthesis

This study evaluated the mid-term results of total knee arthroplasty (TKA) following high tibial osteotomy (HTO), comparing posterior cruciate-retaining prostheses to posterior stabilized prostheses. The Knee Society score for the entire group (20 knees) improved significantly from 62 (median) preoperatively to 87 at the latest follow-up. The postoperative Knee Society score of 85 in posterior cruciate-retaining prostheses (8 knees) was significantly inferior to the 94 score in posterior stabilized prostheses (12 knees). Of Knee Society score, Stability and ROM scores (17 and 21, respectively) in posterior cruciate-retaining TKA were inferior to those in posterior stabilized TKA (25 and 24, respectively). Since postoperative knee instability due to posterior cruciate ligament (PCL) insufficiency is thought to contribute to the inferior results of posterior cruciate-retaining prostheses after HTO, PCL-substituting TKA would be suitable for use after HTO.

Posterior cruciate ligament-substituting total knee arthroplasty in young rheumatoid patients with advanced knee involvement

The integrity and strength of the posterior cruciate ligament (PCL) in the rheumatoid knee are known to be suboptimal. However, the results of PCL-substituting total knee arthroplasty in rheumatoid patients are not well documented. We reviewed 86 PCL-substituting total knee arthroplasties in 52 rheumatoid patients with grade IV or V radiographic disease. The mean age at surgery was 41.9 years. All patients underwent follow-up evaluation for an average of 7.8 years. Revision was performed for 1 knee because of aseptic loosening of the tibial component, and for 3 knees because of deep infection. An isolated insert exchange was performed on one knee. Using revision of any component for aseptic loosening or radiographic loosening as the end point, the mean 10-year survival rate was 94.0%.

Changes in anteroposterior stability following total knee arthroplasty

AbstractThis study evaluated the changes in anteroposterior stability at flexion and extension following posterior cruciate ligament (PCL)-retaining and PCL-substituting total knee arthroplasty (TKA), in comparison with normal knees. Altogether, 29 knees of 24 patients underwent either PCLretaining (n =19) or PCL-substituting (n =10) TKA. Anteroposterior displacement was measured with a KT-2000 arthrometer preoperatively, 1 month after surgery, and again an average of 3 years after surgery. Anteroposterior stability at flexion and extension did not change following PCLretaining TKA and was not significantly different from that of normal subjects, whereas anteroposterior stability increased following PCL-substituting TKA and was significantly greater than that of normal subjects an average of 3 years after surgery.

The influence of the posterior cruciate ligament in the maintenance of joint line in primary total knee arthroplasty: A radiologic study

The aim of this study was to compare 2 total knee arthroplasty (TKA) designs radiologically to determine if a posterior cruciate ligment (PCL)–substituting design led to a built-in error of elevation of the joint line postoperatively. The restoration of the true joint line is a goal in primary TKA, although its effect on outcome has not been established fully. A total of 47 patients had 56 TKAs performed by 2 surgeons using either the Howmedica Kinemax Plus (Rutherford, NJ) PCL-retaining or PCL-substituting TKAs. The patients were randomized to receive one of these designs, and the height of the joint line was assessed radiographically preoperatively and postoperatively. The joint line position preoperatively averaged 2.2 cm from the tibial tuberosity and postoperatively averaged 2.4 cm (PCL substituting) and 2.5 cm (PCL sparing). No difference in the thickness of the polyethylene insert used was seen with either design. The theoretical elevation of the joint line that occurs with the sacrifice of the PCL was not found to occur radiologically.

Cruciate-retaining and cruciate-substituting total knee arthroplasty: An in vitro comparison of the kinematics under muscle loads

The kinematics of posterior cruciate ligament (PCL)-retaining (PCR) and PCL-substituting (PS) total knee arthroplasty (TKA) were compared directly in a robotic, in vitro study, and the forces in the PCL and cam-spine mechanism were measured from 0° to 120° of flexion. The forces in the PCL after PCR TKA and in cam-spine contact after PS TKA increased only at a flexion of ≥90°. Posterior translation of the lateral femoral condyle was significantly greater than translation of the medial femoral condyle in the intact knees, consistent with femoral rollback and internal tibial rotation. The PCR and PS TKAs partially restored these kinematics when the knee flexed >60° (ie, when the forces increased in the PCL and cam-spine mechanism), whereas the PCL-deficient TKA failed to do so. The results reflect the importance of the PCL and cam-spine mechanism after PCL retention and substitution in TKA and confirm the necessity for either one, if knee kinematics are to be restored even partially.

The influence of femoral rollback on patellofemoral contact loads in total knee arthroplasty

Increasing femoral rollback in flexion is thought to reduce patellofemoral contact load in total knee arthroplasty (TKA). The objectives of this study were to quantify the dependence of patellar load on rollback and to assess the effectiveness of posterior cruciate ligament (PCL)–retaining, PCL-sacrificing, and PCL-substituting TKA types in generating rollback. Nine cadaver knees were tested in simulated squatting. Six TKAs that were expected to produce varying amounts of femoral rollback were evaluated: PCL-retaining TKA, PCL-sacrificing TKA, a commercially available PCL-substituting TKA, and 3 modified PCL-substituting TKAs in which the anteroposterior position of the tibial post was varied. Kinematics, quadriceps loads, and patellofemoral contact loads were recorded. Significant differences in rollback were observed in the 30° to 90° flexion range. PCL-sacrificing TKAs generated the least rollback. PCL-retaining TKAs produced greater rollback but had the most variability. PCL-substituting TKAs produced the greatest and most reproducible rollback. Moving the tibial post posteriorly further increased rollback. Increased rollback correlated with reduced patellar load (−2.2%/mm). Reductions in patellar load of 17.6% were observed. Quadriceps loads were reduced by increasing rollback but to a smaller degree (−0.9%/mm). Rollback primarily affects patellar load rather than quadriceps load or efficiency.

Immunohistochemical analysis of mechanoreceptors in the human posterior cruciate ligament: A demonstration of its proprioceptive role and clinical relevance

Although long-term studies report successful results with total knee arthroplasty (TKA), performed with or without posterior cruciate ligament (PCL) retention, controversy exists as to which is preferable in regard to patient outcome and satisfaction. The possible proprioceptive role of the PCL may account for a more normal feeling of the arthroplasty. Although the PCL has been examined using various histological techniques, immunohistochemical techniques are the most sensitive for neural elements. Therefore an immunohistochemical study was designed to determine the patterns of innervation, the morphological types of the proprioceptors, and their immunohistochemical profile. During TKA, samples were obtained from 22 osteoarthritic PCLs and subjected to immunohistochemical analysis with mouse monoclonal antibodies against neurofilament protein (NFP), S100 protein (S100P), epithelial membrane antigen (EMA), and vimentin (all present in neuromechanoreceptors). Three normal PCLs from cadaveric specimens were also obtained and analyzed for comparison. Five types of sensory corpuscles were observed in both the normal and the arthritic PCLs: simple lamellar, Pacini-like, Ruffini, Krause-like, and morphologically unclassified. Their structure included a central axon, inner core, and capsule in lamellar and Pacini corpuscles and variable intracorpuscular axons and periaxonal cells in the Ruffini and Krause-like corpuscles. The immunohistochemical profile showed the central axon to have NFP immunoreactivity, periaxonal cells to have S100P and vimentin immunoreactivity, and the capsule to have EMA and vimentin immunoreactivity. Nerve fibers and free nerve endings displayed NFP and S100P immunoreactivity. The immunohistochemical profile of the PCL sensory corpuscles is almost identical to that of cutaneous sensory corpuscles. Some prior histological studies of the PCL reported Golgi-like mechanoreceptors, and others found encapsulated corpuscles but no Golgi-like structures. This report determined the innervation of the PCL by the more sensitive immunohistochemical means, revealing four major types of encapsulated mechanoreceptors. The plentiful and varied types of encapsulated mechanoreceptors found in even the arthritic PCL suggests a rich proprioceptive role. It is controversial as to whether preservation of the PCL at TKA improves postoperative proprioception. Our findings tend to support those clinical reports of improved proprioception after PCL-retaining versus PCL-substituting TKAs. The presence of many and varied types of mechanoreceptors may account for the improved stair climbing reported in patients with PCL-retaining TKA and may contribute to patient satisfaction and a more normal feeling after TKA.

The posterior cruciate ligament in total knee arthroplasty

The purpose of this study was to answer 2 questions: Does the posterior cruciate ligament (PCL) produce femoral rollback in a single-design, cruciate-sparing total knee arthroplasty (TKA)? Does the PCL prevent posterior tibial displacement when it is retained after a single-design, cruciate-sparing TKA? Knee kinematics and limits of motion were measured with the knees in the following states: (1) intact knee, (2) anterior cruciate-deficient knee, (3) PCL-retaining total knee of a single design (TKA), (4) PCL-retaining TKA with PCL cut, and (5) PCL-substituting TKA. Femoral rollback was then calculated from the above data. The results showed that the PCL was able to prevent posterior translation and maintain femoral rollback when it was preserved during TKA. Therefore, the PCL can be functional after TKA, in a single-design, cruciate-sparing TKA. When the PCL was cut, significant changes in knee kinematics were observed.