The Influence of Patello-Femoral Overstuffing After Modular Unlinked Bicompartmental Knee Arthroplasty (BiKA) for Medial Tibio-Femoral and Patello-Femoral Osteoarthritis of the Knee.

BACKGROUND: The factors affecting results after bicompartmental knee arthroplasty (BiKA) have not been fully elucidated. This major ligament-preserving procedure may be more susceptible to overstuffing of the patello-femoral (PF) joint than the major ligament-sacrificing total knee arthroplasty. Currently, we investigated the effect of PF overstuffing after BiKA on its clinical outcome. METHODS: There were 71 patients (74 knees) who underwent modular unlinked BiKA at our clinic who had a follow-up of 5 to 9 years. Final follow-up results were assessed by evaluating knee range of motion, the 2011 Knee Society Score (2011KSS), Japanese Knee Osteoarthritis Measure, and radiological findings. The degree of postoperative PF overstuffing was evaluated by computed tomography and magnetic resonance images for 55 knees, and the correlation between the degree of overstuffing and postoperative clinical results were examined. RESULTS: Overall clinical results improved significantly after surgery without any revision cases. The X-ray measurements showed the improved coronal alignments and the appropriate implant installation angles. Higher degree of postoperative PF overstuffing caused by insufficient amount of osteotomy on the anterior surface of the femur correlated with worse postoperative total 2011KSS at 2 years after surgery (Spearman's rank correlation coefficient (rs) = -0.387, P = .004), as opposed to no correlation at the time of the final follow-up (Spearman's rank correlation coefficient = 0.068, P = .623). CONCLUSION: Modular unlinked BiKA provided patients with a high level of satisfaction and functional improvement over 5 to 9 years postoperatively. However, because PF overstuffing affects initial patient satisfaction, the amount of osteotomy should be determined carefully during the surgery.

The effect of local injection of tranexamic acid into peri-articular tissue versus drain clamping in total knee arthroplasty: a randomized controlled trial.

BACKGROUND: Tranexamic acid (TXA) is used as a synthetic anti-fibrinolytic agent for total knee arthroplasty (TKA) to reduce postoperative bleeding. Though the effects on bleeding reduction of several methods of administering TXA have been demonstrated, the optimal method remains controversial. Recently, the hemostatic effect of periarticular local injection of TXA during TKA was reported. Although this method can be expected to suppress postoperative bleeding without placing a drain, its hemostatic effect has not yet been assessed in comparison with local injection and other methods of administering TXA. The aim of this randomized, prospective study was to assess the efficacy of local injection of TXA during TKA. METHODS: To confirm the effect of the local injection of TXA, drain clamping was set as the control. The subjects included a prospective series of 109 patients randomly divided into 2 groups: the local injection (group L) and the drain clamping (group D). The main outcome measure was postoperative bleeding. Secondary outcomes included pain, physical measurements, and laboratory findings. RESULTS: The calculated total blood loss (CTBL) in groups L and D was nearly equal and did not show the non-inferiority of group L to group D (883 ± 248 vs. 841 ± 257 ml, P = .564). Drained blood loss was significantly higher in group L than in group D (395 ± 130 vs 276 ± 78.8 ml, P < .0001). There was no significant difference in hidden blood loss between the groups (488 ± 269 vs 565 ± 261 ml, P = .131). The other laboratory findings and physical measurements were identical between the groups. CONCLUSIONS: Although CTBL in group L did not show non-inferiority to group D, the local injection of TXA was considered to be superior for suppressing bleeding considering the risk of the adverse effects of using a drain. TRIAL REGISTRATION: This was a randomized, prospective study registered with UMIN Clinical Trials Registry (Registration number: UMIN000036146, date of disclosure: 10/3/2019).

Side-to-side differences of three-dimensional knee kinematics during walking by normal subjects.

[Purpose] The purpose of this study was to determine the normal range of the side-to-side difference in three dimensional knee kinematics measured by the point cluster technique (PCT). [Subjects] The subjects were twenty-one healthy normal volunteers without knee pain or an episode of injury to the legs. [Methods] The subjects were tested bilaterally at a self-selected normal walking speed and six degrees of freedom knee kinematics were measured using the PCT, and the 95% confidence intervals of the average side-to-side differences in flexion-extension (FE), adduction-abduction (AA), internal-external (IE) rotation, and anterior-posterior (AP), medial-lateral (ML), superior-inferior (SI) translation in each stage of the gait cycle were determined. [Results] The average side-to-side differences and their 95% confidence intervals in rotation/translation in each stage of the gait cycle were determined. The side-to-side differences in AA rotation and AP translation of the tibia were significantly larger in the swing phase than in the stance phase. [Conclusion] The side-to-side differences in AA rotation and AP translation were highly dependent on the stage of the gait cycle. Therefore, the normal ranges of the side-to-side differences in knee kinematics in each stage of the gait cycle, in particular AA rotation and AP translation of the tibia, is useful information for evaluating knee kinematics during walking.

Internal Rotation, Varus, and Anterior Femoral Component Malalignments Adversely Affect Patellofemoral Joint Kinematics in Patellofemoral Arthroplasty.

Background: Patellofemoral arthroplasty (PFA) is reported to provide nearly normal PF joint kinematics but only with adequate surgical techniques. This study evaluated the effects of various femoral component settings on patellar component biomechanics. Methods: A dynamic musculoskeletal computer simulation analyzed normal knee and standard PFA models, as well as 8 femoral component malposition models: 5° internal or external rotation, 5° valgus or varus, 5° extension or flexion, and 3-mm or 5-mm anterior positioning. Mediolateral patellar translation, lateral patellar tilt, and contact force and stress at the PF joint were measured in each model during gait. Results: The patella in the standard PFA model was shifted up to 5.0 mm laterally near heel off and was tilted up to 3.0° laterally at heel strike compared to the normal knee model. The patella in the external rotation model translated more laterally in the direction of the femoral component setting than in the standard model. However, in the internal rotation and varus alignment models, the patellar lateral shift occurred largely in the opposite direction of the femoral component setting. The patella in most models was tilted in the same direction as the femoral component setting. The PF contact force was increased, especially in the anterior femoral position models, by up to 30 MPa compared with 20 MPa in the standard model. Conclusions: Internal rotation, varus, and anterior femoral component settings during PFA should be avoided to reduce postoperative complications, whereas external rotation might be appropriate only for cases with lateral patellar instability.

Higher Association of Pelvis-Knee-Ankle Angle Compared With Hip-Knee-Ankle Angle With Knee Adduction Moment and Patient-Reported Outcomes After High Tibial Osteotomy.

BACKGROUND: High tibial osteotomy (HTO) reduces the load distribution of the medial compartment by modifying leg alignment. Knee adduction moment (KAM), a surrogate measure of dynamic loading in the knee joint, decreases after HTO. However, leg alignment does not fully account for KAM. PURPOSE: To assess the association between the pelvis-knee-ankle angle (PKA), a novel radiographic parameter reflecting leg alignment and pelvic width, and KAM and patient-reported outcomes after HTO. STUDY DESIGN: Cross sectional study; Level of evidence, 3. METHODS: PKA is the angle between the line from the midpoint of the anterior superior iliac spine to the center of the knee joint and the mechanical axis of the tibia. In this study, 54 patients with medial compartment knee osteoarthritis and varus alignment who underwent 3-dimensional gait analysis preoperatively and 2 years after medial open-wedge HTO were evaluated. The primary outcomes were hip-knee-ankle angle (HKA), PKA, KAM peaks, and Knee Society Score (KSS). Single and multivariate regression analysis including PKA and KAM peaks as well as other demographic and radiologic factors was performed. RESULTS: HKA was weakly correlated with the first peak KAM (r = -0.33; P < .01) and second peak KAM (r = -0.27; P = .01) before HTO, but not significantly correlated after HTO. PKA was moderately correlated with the first peak KAM (r = 0.45; P < .01) and second peak KAM (r = 0.45; P < .01) before HTO and with the first peak KAM (r = 0.51; P < .01) and second peak KAM (r = 0.56; P < .01) after HTO. Multivariate linear regression revealed that postoperative PKA was still associated with the KAM peaks after HTO. Only postoperative PKA was correlated with the KSS satisfaction subscale (r = -0.30; P = .03). CONCLUSION: Although HKA was not correlated with KAM peaks after HTO, PKA was significantly correlated with KAM peaks in patients with varus knee osteoarthritis after HTO.

Assessing knee joint biomechanics and trunk posture according to medial osteoarthritis severity.

During progression of knee osteoarthritis (OA), gait biomechanics changes three-dimensionally; however, its characteristics and trunk posture according to OA severity remain unknown. The present study investigated three-dimensional knee joint biomechanics and trunk posture according to knee OA severity. Overall, 75 patients (93 knees) with medial knee OA [Kellgren-Lawrence grade ≥ 2, grade 2: 20 patients with 24 knees (mean 60.0 years old); grade 3: 25 with 28 knees (mean 62.0 years old); grade 4: 30 with 41 knees (mean 67.9 years old)] and 14 healthy controls (23 knees, mean 63.6 years old) underwent gait analysis using an optical motion capture system and point cluster technique. In grade 2 knee OA, the relative contribution of the knee adduction moment (KAM) increased significantly (P < 0.05), and that of the knee flexion moment decreased (P < 0.05) prior to significant progression of varus knee deformity. Grade 3 knee OA showed significant exacerbation of varus knee deformity (P < 0.01) and KAM increase (P < 0.001). The maximum knee extension angle decreased (P < 0.05) and trunk flexion increased during gait in grade 4 knee OA (P < 0.001). Our study clarified the kinematics and kinetics of medial knee OA with trunk flexion according to severity. Kinetic conversion occurred in grade 2 knees prior to progression of varus deformities, knee flexion contractures, and sagittal imbalance during gait in patients with severe knee OA.

Kinematics and center of axial rotation during walking after medial pivot type total knee arthroplasty.

PURPOSE: In recent years, the medial pivot (MP) type total knee arthroplasty (TKA) implant has been developed and marketed for achieving more natural kinematics with MP. However, little is known about the pivot pattern during walking after MP type TKA. This study aimed to determine the kinematics and center of axial rotation during walking after MP type TKA. METHODS: This randomized prospective study enrolled 40 patients with MP type TKA, 20 with cruciate-substituting TKA (MP-CS group), 20 with posterior-stabilized TKA (MP-PS group), and 10 healthy volunteers (control group). The kinematics and center of axial rotation during overground walking were measured by a three-dimensional motion analysis system. The six-degrees-of-freedom kinematics of the knee were calculated by the point cluster method. RESULTS: The amount of change in knee flexion in early stance phase was significantly lower in the MP-CS and MP-PS groups than in the control group. The femur showed anterior translation during early stance phase in all three groups. The median center of axial rotation in the transverse plane was predominantly on the lateral side of the knee during stance in all groups. CONCLUSIONS: Kinematics during gait are thought to be determined by physical posture, the kinetic chain during weight-bearing, and the kinematic features of adjacent structures, such as the behavior of the biarticular muscles. MP-CS and MP-PS did not necessarily induce rotational motion centered on the medial ball-in-socket component during walking; translational and lateral pivoting movements were also observed. Long-term follow-up is needed to monitor for polyethylene wear and implant loosening.

The incidence and cross-sectional area of the meniscofemoral ligament.

BACKGROUND: The incidence, morphologic characteristics, and cross-sectional area of meniscofemoral ligaments of the knee are still not clarified. HYPOTHESIS: The incidence of meniscofemoral ligaments is very high, and they contribute significantly to the cross-sectional area of the posterior cruciate ligament complex. STUDY DESIGN: Descriptive laboratory study. METHODS: Clinical study: During arthroscopic anterior cruciate ligament reconstruction, the presence of a meniscofemoral ligament was confirmed in 38 patients (16 men, 22 women; mean age, 23.6 years) by observation and probing. Laboratory study: Posterior cruciate ligaments with the lateral meniscus attached were obtained as specimens from 30 patients (3 men, 27 women; mean age, 71.9 years) during total knee arthroplasty. The posterior cruciate ligament and meniscofemoral ligaments were observed, and the cross-sectional area was measured using an area micrometer. RESULTS: Clinical study: The anterior meniscofemoral ligament was found in 36.8% of patients, the posterior meniscofemoral ligament was found in 71.1%, and both ligaments were found in 26.7%. The overall incidence of at least 1 meniscofemoral ligament was 84.2%. Laboratory study: The anterior meniscofemoral ligament was present in 5 (16.7%) cases, and the posterior meniscofemoral ligament was present in all cases (100.0%). The cross-sectional area of the posterior cruciate ligament proper was 50.1 +/- 16.9 mm(2), that of the anterior meniscofemoral ligament was 2.3 +/- 1.2 mm(2), and that of the posterior meniscofemoral ligament was 7.5 +/- 2.5 mm(2). The mean ratio of the cross-sectional area of meniscofemoral ligaments to the posterior cruciate ligament proper was 17.2% (4.0%-38.9%). The origin of the posterior meniscofemoral ligament from the posterior horn of the lateral meniscus could be classified into 5 types. CONCLUSION: The meniscofemoral ligaments contributed significantly to the cross-sectional area of the posterior cruciate ligament complex.

Description of a new endoscopic posterior cruciate ligament reconstruction and comparison with a 2-incision technique.

PURPOSE: We introduce our technique (a new route for the graft) of endoscopic posterior cruciate ligament (PCL) reconstruction and describe the advantages in comparison with the conventional surgical technique. TYPE OF STUDY: Nonrandomized control study. METHODS: The idea of this surgical technique is to minimize graft angulation at the inner edge of the bone tunnel. The tibial entry point of the guide pin is under the tibial lateral subcondylar flare, approximately 1 to 2 cm anterior to the posterior cortex. This creates less graft angulation on the posterior aspect of the tibia. A new drill system has been devised to allow antegrade femoral drilling starting from inside the notch. This method also allows better femoral tunnel orientation. As a substitute graft material, we use autogenous hamstring tendons, and we secure them with an EndoButton (Smith & Nephew, Andover, MA) and post screw. From 1992 to 1995, 43 2-incision PCL reconstructions using autogenous hamstring tendons were performed. From 1995 to 2001, 90 endoscopic PCL reconstructions using looped autogenous hamstring tendons and an EndoButton were performed. Cases were specified according to the inclusion criteria of this study. As a result, 51 patients were included in this study. The 2-incision group comprised 22 patients, and the endoscopic group comprised 29 patients. The clinical evaluation was performed using the International Knee Documentation Committee (IKDC) form. The quadriceps strength was measured using Biodex System II (Biodex, New York, NY). The period of time to achieve 90 degrees flexion after surgery was also compared. RESULTS: No significant differences were seen between the 2 groups tested with respect to the overall IKDC rating score. Side-to-side differences of anteroposterior total laxity (KT-1000, manual maximum) was 3.95 +/- 1.96 mm in the 2-incision group and 2.38 +/- 1.42 mm in the endoscopic group (P <.05). The average time to achieving 90 degrees of flexion after surgery was 16.6 +/- 8.6 days in the 2-incision group and 12.1 +/- 3.5 days in the endoscopic group. Achievement of range of motion in the endoscopic group was significantly shorter. The peak torque of isokinetic contraction in the endoscopic group was significantly greater than in the 2-incision group 1 year after surgery. CONCLUSIONS: Better posterior stability and quicker postoperative recovery of range of motion and muscle strength were advantages of the endoscopic technique over the 2-incision technique in PCL reconstruction.

A new endoscopic posterior cruciate ligament reconstruction: Minimization of graft angulation.

PURPOSE: The purpose of this report is to present a new surgical technique for endoscopic posterior cruciate ligament (PCL) reconstruction and to elucidate the preliminary results. Surgical Technique: The concept of this surgical technique is to minimize the graft angulation at the inner edge of the bone tunnel. The tibial entry point of the guide pin is under the tibial lateral subcondylar flare approximately 1 to 2 cm anterior to the posterior cortex and 4 cm distal to the joint surface. This creates less graft angulation on the posterior aspect of the tibia. A new drill system has been devised to allow antegrade femoral drilling starting from inside the notch. This method also allows better femoral tunnel orientation. As a substitute graft material, we use autogenous hamstring tendons, and we secure them with an EndoButton (Smith & Nephew, Mansfield, MA) and post screw. METHODS: Since 1995, 40 knees have undergone endoscopic PCL reconstruction. Twenty-one patients were evaluated after a minimum follow-up of 1 year (17.9 +/- 7.7 mo). The clinical evaluation was performed using the International Knee Documentation Committee (IKDC) form. RESULTS: The range of motion was rated as A for 17 cases, B in 3 cases, and C in one case. The total anteroposterior translation (KT-1000, manual-maximum) showed a range of 1.0 to 5.5 mm (mean, 2.8 mm). The ratings of the ligament examination were A in 9 cases and B in 12 cases. The final IKDC evaluation was A (normal) in 3 cases, B (nearly normal) in 17 cases, and C (abnormal) in 1 case. CONCLUSIONS: A good clinical outcome was achieved with our endoscopic PCL reconstruction. The reduction of the graft angulation may contribute to the good results for PCL reconstruction.

Two-stage reconstruction with autografts for knee dislocations.

Traumatic knee dislocations are severe injuries that involve damage to the anterior cruciate ligament, the posterior cruciate ligament, and the lateral or medial ligamentous structures. There are no established methods of treatment. The objective of the current study was to report the clinical outcome of a two-stage autologous reconstruction on nine knees (eight patients). The mean followup was 40.1 months. The first stage of the reconstruction was done at a mean of 2 weeks after the injury, and the posterior cruciate ligament was reconstructed by an arthroscopically assisted technique using contralateral autogenous hamstring tendon as the graft material. Three months later, the second stage of the reconstruction was done for the ligaments that had not healed with conservative treatment. Arthroscopically assisted anterior cruciate ligament reconstruction was done on all of the knees using the ipsilateral autogenous hamstring tendon or bone-patellar tendon-bone as the graft material. At the same time, a medial collateral ligament reconstruction using an autogenous semitendinosus tendon was done on one knee, and reconstruction of the posterolateral ligamentous structures using a biceps tendon was done on three knees. Each of the knees that was reconstructed was capable of full extension, and the mean degree of passive flexion was 139.5 degrees +/- 5.2 degrees. The mean side-to-side difference in anteroposterior total laxity (KT-1000 arthrometer, manual maximum) was 2.3 +/- 1.9 mm. None of the knees had lateral or medial instability. All of the injured ligaments were able to be reconstructed with autografts, and severe contracture was able to be prevented. A good clinical outcome can be achieved when two-stage reconstruction is used for traumatic knee dislocations.

Clinical results of single-level posterior lumbar interbody fusion using the Brantigan I/F carbon cage filled with a mixture of local morselized bone and bioactive ceramic granules.

STUDY DESIGN: A retrospective study to evaluate the results of single-level posterior lumbar interbody fusion (PLIF) using the Brantigan I/F cage (DePuy AcroMed Corp., Raynham, MA) filled with a mixture of local morselized autologous bone and bioactive ceramic granules. OBJECTIVES: To report the clinical and radiologic results of PLIF using the Brantigan I/F cage for lumbar degenerative pathologies with instability. SUMMARY OF BACKGROUND DATA: The Brantigan I/F cage for PLIF was designed to improve the fusion success of interbody fusion by separating the mechanical and biologic functions of PLIF using an implant device and autologous bone from the iliac crest. Although high fusion rates have been reported, donor site morbidity caused by bone harvest from the iliac crest remains a concern. The possibility of accomplishing cage PLIF using a mixture of local morselized bone and a bone extender was studied. METHODS: A total of 25 patients underwent single-level PLIF using the Brantigan I/F cage filled with a mixture of local morselized bone and bioactive ceramic granules. All patients were observed for more than 2 years (average 2 years 7 months) and evaluated by clinical rating and radiograph. RESULTS: Preoperative Japanese Orthopedic Association clinical scores were significantly improved in all patients at the time of follow-up. The average improvement rate was 83.1%. There were no serious complications. Minor complications included two dural tears and two cases of thrombophlebitis. No patient required blood transfusion. All patients achieved radiographic fusion and radiographic stability, although two patients fused in a collapsed position. Regional alignment of the operated segments was restored at surgery and maintained at the time of final follow-up. There were statistical improvements in percent slip and percent posterior disc height in patients with spondylolisthesis. CONCLUSIONS: Posterior lumbar interbody fusion using the Brantigan I/F cage with a mixture of local morselized bone and bioactive ceramic granules can yield a solid union with satisfactory regional alignment and adequate disc height without harvest of iliac crest bone.