Double-level osteotomy for severe varus osteoarthritic knees can prevent change in leg length and restore physiological joint geometry

BackgroundIt is unclear whether double-level osteotomy (DLO) combining closed-wedge osteotomy in the distal femur and open-wedge osteotomy in the proximal tibia deformity can prevent change in leg length and excessive coronal inclination of the tibial articular surface in surgical correction of the severe varus knee. The purpose of this study was to examine the postoperative change in leg length as well as radiological and clinical outcomes following DLO compared with the results obtained from knees undergoing isolated open-wedge high tibial osteotomy (OW-HTO).MethodsIn cases of severe varus knee deformity (hip–knee–ankle angle (HKA) > 10°) 29 patients undergoing DLO and 35 patients undergoing OW-HTO were included. If the predicted mechanical medial proximal tibial angle (mMPTA) was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation, then DLO was considered as the surgical of option. In cases where these criteria were not met, OW-HTO was selected. All patients were followed up for a minimum of 2 years.ResultsThe changes in the length of the whole leg in the DLO and OW-HTO groups averaged 2.3 ± 4.8 mm and 9.3 ± 7.2 mm, respectively (P < 0.001). mMPTA of more than 95° was found in no knee in the DLO group.ConclusionsThis study showed that DLO could avoid leg length change and non-physiologic joint lines when performed in patients with varus HKA > 10°, and the predicted mMPTA was 95° or greater or the wedge size was 15 mm or greater in the surgical simulation.     

What is the relationship between the “Fujisawa point” and postoperative knee valgus angle? A theoretical,computer-based study

BackgroundThe purpose of this study was to determine the relationship between the Fujisawa point and postoperative knee valgus angle and the anatomical factors influencing this relationship.MethodsAn experimental study was conducted including 116 patients with medial compartment knee osteoarthritis undergoing treatment with open-wedge high tibial osteotomy (OWHTO). Each patient received simulated HTO through the Fujisawa point in the picture archiving and communication system (PACS). The preoperative hip-knee-ankle (HKA) angle and lower extremity anatomical parameters were recorded before the computerized HTO simulation. The postoperative knee valgus angle was measured after this procedure. A second simulation HTO was performed to adjust the mechanical axis to the optimal valgus angle (4.5°) and calculate the percentage of the tibial plateau width where the Mikulicz line crossed the knee. The Spearman correlation test and multivariate regression were used for analysis.ResultsThe median preoperative HKA varus angle of this study cohort was 174.1° (170.8, 176.2°). The median knee valgus angle after simulated osteotomy through the Fujisawa point was 2.4° (2.1, 2.7°). The valgus angle was positively correlated with the tibial plateau width (r = 0.23, p = .013) and preoperative HKA angle (r = 0.32, p < .001). Multivariate regression analysis showed that the preoperative HKA angle was a significant contributor to the postoperative valgus angle. When conducting the osteotomy with the optimal valgus angle (4.5°), the percentage of the Mikulicz line passing through the tibial plateau was 71.93% (67–78%).ConclusionsThe preoperative HKA angle affects the postoperative valgus angle after HTO. If the optimal valgus angle of 4.5° is desired, a more lateral position of the Fujisawa point should be targeted during OWHTO, which accounts for approximately 71.9% of the tibial plateau.     

Bilateral unicompartmental knee arthroplasty for windswept knee osteoarthritis: A report of 13 cases

BackgroundWindswept deformity is a condition of the lower limbs with a valgus knee on one side and a varus knee on the other. We present a case series of bilateral unicompartmental knee arthroplasty (UKA) for windswept knee osteoarthritis (WSKO).MethodsWe analysed the outcomes of 26 knees of 13 consecutive patients with WSKO treated with bilateral UKA. The mean age was 73.0 years and the mean follow up period was 2.6 years. Pre- and postoperative Oxford Knee Score (OKS) and Japanese Orthopaedic Association (JOA) score, radiological measurements and postoperative complications were evaluated. No knees required revision for either infection or loosening.ResultsThe mean preoperative OKS was 25.3 ± 9.7, which increased to 34.9 ± 5.8 at the latest follow up. The mean preoperative JOA scores for the varus and the valgus sides were 64.6 ± 12.5 and 66.9 ± 14.1, which increased to 85.0 ± 11.3 and 84.6 ± 11.2, respectively, after operation.ConclusionsOur results show that good short-term clinical results can be achieved by bilateral UKA in cases of WSKO. Bilateral UKA may be an effective treatment for WSKO if indications are met.     

Can total knee arthroplasty restore the correlation between radiographic mechanical axis angle and dynamic coronal plane alignment during gait?

BackgroundTotal knee arthroplasty (TKA) is the treatment of choice for end-stage knee osteoarthritis. Postoperative static knee alignment has been recognized as a key component of successful surgery. A correction toward the kinematics of a native knee is expected after TKA, with an aim for neutral mechanical alignment. The evolution of frontal plane knee kinematics is not well understood.MethodsNineteen patients awaiting TKA were recruited. Three-dimensional knee kinematics during treadmill gait were assessed pre-operatively, 12 months after surgery, and compared to a control group of 17 asymptomatic participants.ResultsMean radiographic mechanical alignment was corrected from 5.4° ± 5.0 (Standard Deviation) varus pre-operatively to 0.1° ± 2.0 (Standard Deviation) valgus postoperatively (P = 0.002). Mean stance coronal plane alignment decreased from 6.7° ± 4.0 (Standard Deviation) varus per-operatively to 2.1° ± 3.8 (Standard Deviation) postoperatively (P = 0.001). Correlation between radiographic mechanical axis angle and dynamic frontal plane alignment during gait, before and after surgery, was weak (pre-operative R = 0.41; postoperative R = 0.13) compared to control (R = 0.88). In the sagittal plane, TKA patients maintained their pre-operative stiff knee gait adaptation. Postoperative transverse plane kinematics suggested restoration of external tibial rotation during swing after TKA compared to control (Pre-operative 3.1°, postoperative 6.8°, control 7.1°, P = 0.05).ConclusionThe lack of correlation between static and dynamic alignment suggests that static radiographic coronal alignment of the knee does not accurately predict dynamic behavior. In the sagittal plane, pre-operative gait adaptations were still present 12 months after surgery, supporting the need for a functional assessment to guide postoperative rehabilitation following TKA.     

Residual varus alignment after total knee arthroplasty increases knee adduction moment without improving patient function: A propensity score-matched cohort study

BackgroundTargeting residual varus alignment in total knee arthroplasty may be functionally beneficial to preoperative varus patients.MethodsBilateral TKA patients were enrolled. According to the postoperative hip-knee-ankle axis, patients were allocated into residual varus (3° ± 1°) alignment group or neutral (0° ± 1°) alignment group. Then, 1:2 propensity score matching was used to match preoperative variables. Finally, matched neutral (n = 45) and varus groups (n = 32) were followed-up for two years and compared. The primary outcome was the Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes were range of motion (ROM), Knee Society knee score and function score, spatiotemporal gait parameters, dynamic alignment, knee flexion angle, knee adduction moment (KAM) and internal knee extension moment.ResultsAt two years after surgery, the mean difference of WOMAC score was 0.3 (95% CI, [? 3.1, 3.7]) between the two groups. All secondary outcomes, except KAM and dynamic alignment, showed no significant difference between the two groups. Residual varus alignment group showed increased KAM and maximum KAM was 19% higher (P = 0.006).ConclusionsResidual varus alignment showed no clinical benefits, and both groups of patients had a functionally identical knee gait biomechanics, except for increased KAM and varus alignment. The authors consider that even in patients with varus alignment, the first principle is still achieving neutral alignment, which is helpful for reducing the KAM.Level of evidenceIII, retrospective cohort study.     

Ten year outcomes for the prospective randomised trial comparing unlinked,modular bicompartmental knee arthroplasty and total knee arthroplasty

BackgroundA sizeable proportion of knee osteoarthritis is limited to the medial and patellofemoral compartments. Whilst short- and medium-term studies comparing bicompartmental knee arthroplasty (BCA) and total knee arthroplasty (TKA) have shown similar outcome scores, there are no studies comparing long-term outcomes. This study aims to determine which procedure resulted in superior long-term outcome scores.MethodsForty-eight patients with medial and patellofemoral compartment knee osteoarthritis were randomised to receive treatment in two groups: unlinked, modular BCA and TKA. The main outcome measures compared were the range of motion, Knee Society Function Score, Knee Society Knee Score, Oxford Knee Score, Physical Component Score and Mental Component Score of SF-36 pre-operatively and post-operatively up to 10 years. Radiographs of the operated knees were taken pre-operatively, post-operatively and at 10-year follow-up.ResultsTwenty-six underwent BCA and 22 underwent TKA. Overall improvement was seen in both groups compared to pre-operatively, however there were no significant differences detected between the groups at 10 years. The median Hip–Knee–Ankle (HKA) angle was 183.38 (175.17–187.94) in the BCA group and 180.73 (174.96–185.65) in the TKA group. One patient from the BCA group had a peri-prosthetic fracture necessitating revision surgery to a TKA.ConclusionsOutcome scores for BCA results were comparable to TKA at long-term follow-up. BCA is an alternative arthroplasty option in selected patients.     

Characteristic kinematics of floor-sitting activities after posterior-stabilized total knee arthroplasty determined using model-based shape-matching techniques

BackgroundDetailed kinematics of floor-sitting activities after total knee arthroplasty (TKA) have not been well explored. Knee kinematics of cross-legged sitting, seiza-sitting, and side-sitting after TKA were examined to clarify the differences in tibiofemoral kinematics of each activity.MethodsSubjects were 40 knees in 20 osteoarthritic patients who underwent bilateral TKA with a high-flexion fixed-bearing posterior-stabilized prosthesis. Dynamic radiographs of floor-sitting activities were taken, and the knee kinematics were compared among the three activities. The patients were also divided into two groups (possible/easy group and impossible/no-try group) for each activity, and group comparisons were conducted.ResultsThe maximum implant flexion angle was significantly greater in seiza-sitting. In valgus/varus rotation, seiza-sitting demonstrated neutral rotation, while cross-legged sitting showed varus of about 10°, and side-sitting exhibited valgus. In tibial internal/external rotation, seiza-sitting demonstrated a constant rotational angle, while cross-legged sitting showed tibial internal rotation with flexion, and side-sitting exhibited tibial external rotation with flexion. The kinematic pathway during deep flexion illustrated the medial pivot pattern in cross-legged sitting, a small amount of bicondylar rollback in seiza-sitting, and the weak lateral pivot pattern in side-sitting. A greater flexion angle was the important factor for the performance of each floor-sitting activity followed by varus laxity at 10° knee flexion.ConclusionsThis study successfully revealed characteristic kinematic patterns of TKA knees in three floor-sitting activities. Obtaining a greater knee flexion with adequate lateral laxity is the key to enhancing postoperative floor-sitting activities.     

The value of the intra-operative clinical mechanical axis measurement in open-wedge valgus high tibial osteotomies

IntroductionIn high tibial osteotomies (HTO) the correction needs to be precise and intra-operative assessment is essential. The purpose of this study was to evaluate the use of the intra-operative clinical mechanical axis measurement and compare it to the post-operative weight bearing situation on standing whole leg radiographs (WLR). Secondly, we evaluated the preoperative planned wedge size and compared it to the final results in 27 HTOs.MethodsThe mechanical axis deviation (MAD), expressed as a percentage of the tibial width (0% is medial edge, 100% is lateral edge) and the hip–knee–ankle angle (HKA) were calculated and analyzed. Preoperative planning was done by projecting the desired mechanical axis on the lateral tibial spine on the WLR and subsequently calculating the necessary correction angle. A 3° valgus correction was desired.ResultsThe results showed a preoperative standing MAD of 26.6%, or about halfway the medial tibial plateau. The MAD was corrected to 57.0% intra-operative, meaning a slight valgus. On the postoperative standing WLR, the MAD had shifted significantly to 62.0% (95% CI = ? 9.2 to ? 2.7; p < 0.01) compared to the intra-operative 57.0% axis. The HKA angle changed 8.2° from 5.1° varus preoperative to 3.1° valgus postoperative.ConclusionWhen aiming the mechanical axis at the lateral tibial spine, a slight undercorrection was introduced, but due to a valgus shift while weight bearing, a satisfying final outcome of 3° valgus average was achieved. Preoperative calculation of the wedge size remains important for surgical planning, but it does not always correspond to the actual used wedge size.     

Surgical epicondylar axis is not orthogonal to the femoral mechanical knee axis in valgus knees with primary osteoarthritis: Three-dimensional analysis according to knee coronal alignment in 112 patients

BackgroundDuring total knee arthroplasty (TKA), most surgeons align the femoral component along the surgical epicondylar axis (SEA) considering it as orthogonal to the femoral mechanical axis. However, it is still unclear how SEA coronal alignment varies according to the native coronal knee alignment. The main goal of this study was to analyze the SEA orientation according to the native coronal knee morphotype.MethodsA total of 112 patients underwent a three-dimensional (3D) -planning-based TKA. The SEA was then determined by locating the epicondyles on 3D models. The 3D femoral and tibial mechanical axes were marked and the femoral (FMA) and tibial (TMA) mechanical angles were measured. The native HKA angle was measured as FMA + TMA. The SEA orientation angles were measured in the coronal (SEA-α) and axial (SEA-β) plane. SEA orientation was compared between the valgus, neutral, and varus knees.ResultsThe mean SEA-α angle was 90.2 ± 3° and the mean axial SEA-β angle was 92.2 ± 1.3°. The SEA-α angle was significantly higher in the valgus group compared with the neutral group (92.3 ± 2.9°, 90 ± 2.9°, P = 0.0009) whereas there was no significant difference in the SEA-α angle between the varus and the neutral group (89.7 ± 2.3°, 90 ± 2.9°, P = 0.32).ConclusionsIn contrast to the neutral and varus knees, the SEA was not orthogonal to the femoral mechanical axis in patients undergoing TKA for primary osteoarthritis. Our results suggest adapting the coronal alignment of the femoral component during TKA, while maintaining an average 2° valgus in valgus knees. By contrast, with varus and neutral knees, our data support the use of a mechanical alignment.     

Medial stabilizing technique preserves anatomical joint line and increases range of motion compared with the gap-balancing technique in navigated total knee arthroplasty

BackgroundMedial compartment stability is important in total knee arthroplasty. The medial stabilizing technique (MST) has been proposed to achieve medial stability without excessive medial soft tissue release in total knee arthroplasty. Herein, we compare the MST and the gap-balancing technique (GBT) in navigated total knee arthroplasty.MethodsWe retrospectively analyzed 70 patients with varus knee osteoarthritis who underwent primary total knee arthroplasty using the navigation system. They were divided into MST (n = 39) and GBT (n = 31) groups. We assessed intraoperative navigation data, radiographic data, and insert thickness. Preoperative and postoperative joint line changes were measured. We also assessed range of motion and clinical instability before and after total knee arthroplasty. These parameters were statistically compared between the groups.ResultsCompared with the GBT group, medial extension gaps were significantly smaller in the MST group (P = 0.008). The gap difference between medial and lateral extension was significantly greater in the MST group (P = 0.018). Other navigation data showed no significant differences. Insert thickness and joint line changes were significantly lower in the MST group (P = 0.001, P = 0.018, respectively). Postoperative range of motion was significantly greater in the MST group (P = 0.032). There was no objective or subjective knee instability in either group.ConclusionThe MST could avoid knee joint line changes and might increase postoperative range of motion. Although the MST permitted a discrepancy between medial and lateral gaps, no patients felt knee instability. The MST might improve the results of total knee arthroplasty.     

Conventional knee films hamper accurate knee alignment determination in patients with varus osteoarthritis of the knee

Surgical therapeutic procedures such as knee osteotomy and knee replacement depend on proper knee alignment assessment. The aim of this study was to evaluate if femorotibial (FT) measurement on short knee films may be used in clinical settings. The study population comprised 68 patients with symptomatic medial compartmental knee osteoarthritis. We measured the FT angle with the use of mid-diaphyseal lines (FTa), and the knee joint centre (FTb) to determine anatomical knee alignment on a short knee image. Then, the accuracy of alignment was compared to the gold standard Hip–Knee–Ankle (HKA) angle on a full-limb view. FTa angle assessment correlated well (r = 0.65) with the HKA angle. However, this method showed poor inter-observer agreement (ICC = 0.37). 3% of patients were incorrectly classified as having valgus alignment. Good intra- and inter-observer agreements were observed for FTb angle measurement (ICC = 0.89 and 0.79; respectively). But correlation between HKA and FTb angles was low (r = 0.34). 15% of patients were incorrectly classified as having valgus alignment. Short knee images cannot substitute whole leg views when accurate assessment of knee alignment is essential.     

Comparison between navigated reported position and postoperative computed tomography to evaluate accuracy in a robotic navigation system in total knee arthroplasty

BackgroundComputer navigation increases reproducibility compared to non-navigated total knee arthroplasty (TKA). Robotics navigation is a branch of computer navigation technology that might further improve accuracy of implant placement. The aim of this study is to assess the accuracy achieved in TKA with a robotic navigation system.MethodsOne hundred seventy three knees. System studied: Omni navigation System (OMNI, Raynham, MA). Navigated femoral and tibial cuts were compared to postoperative computed tomography (CT). Measurements reviewed: femoral coronal alignment (FCA), femoral sagittal alignment (FSA), femoral rotational alignment (FRA), tibial coronal alignment (TCA), tibial sagittal alignment (TSA) and hip–knee–ankle (HKA) angle. Statistical analysis was made using R.ResultsThe mean differences between the navigated reported and the CT positions were: FCA: 0.1 ± 1.2° more varus (P = 0.58), FSA: 1.5 ± 0.3° more flexed (P < 0.001), FRA: 0.0 ± 1.7° (P = 0.93), TCA: 0.7 ± 1.1° more varus (P < 0.001), TSA: − 1.3 ± 1.5 more negative slope (P < 0.001), HKA angle: 0.4 ± 2.4 more varus (P < 0.049).The percentages of concordance inside a three degree difference were: FCA: 98% (169 knees), FSA: 100% (173 knees), FRA: 94% (162 knees), TCA: 99% (171 knees), TSA: 93% (161 knees) and HKA angle: 83% (144 knees).ConclusionsThe current study showed that the robotic navigation system studied is highly accurate regarding final implant positioning for FCA, FRA and TCA. It has less accuracy in FSA, TSA and the HKA angle.     

In vivo kinematic comparison before and after mobile-bearing unicompartmental knee arthroplasty during high-flexion activities

BackgroundMany patients who undergo unicompartmental knee arthroplasty (UKA) have an expectation that their knee flexion would increase following its replacement. Additionally, the survival rate of mobile-bearing UKA (MB-UKA) is high. However, the effect on the patient's kinematics remains unknown. This study aimed to clarify the kinematic effect of MB-UKA knees during high-flexion activities by comparing the in vivo kinematics before and after surgery.MethodsA squatting motion was performed under fluoroscopic surveillance in the sagittal plane before and after MB-UKA. To estimate the spatial position and orientation of the knee, a two-dimensional/three-dimensional registration technique was used. The femoral rotation and varus–valgus angle relative to the tibia and anteroposterior (AP) translation of the medial and lateral side of the femur on the plane perpendicular to the tibial mechanical axis in each flexion angle were evaluated.ResultsRegarding the varus–valgus angle, the preoperative knees indicated a significant varus alignment compared with the postoperative knees from 10° to 60° of flexion. There were no significant differences in the femoral rotation angle, AP translation, and kinematic pathway before and after MB-UKA in the mid-flexion of the range of motion.ConclusionThere were differences between the varus–valgus knee kinematics before and after MB-UKA, from 10 to 60° of flexion, but no difference from midrange of flexion to deep flexion. In addition, the rotational knee kinematics before and after MB-UKA was not significantly different.     

The effect of component alignment on clinical outcomes in fixed bearing unicompartmental knee arthroplasty

BackgroundThe aim of this study is to report component alignment in a series of ZUK fixed bearing unicompartmental knee arthroplasty (UKA) implants and compare this to clinical outcomes.MethodsThe radiographs, Knee Society Scores (KSS) and knee flexion of 223 medial UKAs were evaluated. The following alignment parameters were assessed; coronal and sagittal femoral component angle (c-FCA and s-FCA), coronal and sagittal tibia component angle (c-TCA and s-TCA) and the coronal tibiofemoral angle (c-TFA). Each alignment parameter was grouped at consecutive 2.5° intervals, mean KSS and knee flexion was then compared between the interval groups.Results96.4% of femoral components were between 7.5° of varus and valgus and 95.1% between 7.5° extension and 5° flexion. 89.6% of tibial components were between 7.5° of varus and 2.5° valgus and 97.3% between 2.5° and 15° flexion. There was no significant difference between the KSS or knee flexion between any of the incremental groups of component alignment. Mean c-TFA was 0.2 ± 3.0°, 92.4% were between −5° (varus) and 5° (valgus). KSS were significantly greater for two of the increments with slightly more varus. Linear regression analysis showed there was very weak correlation (R² = 0.1933) between c-TFA and c-TCA.ConclusionsThe results of this study show that fixed bearing UKA components are forgiving to accommodate some variation in tibial and femoral component position without effecting clinical outcome scores or knee flexion. Limb alignment matters more than component position and knees with slight varus tibiofemoral alignment have better clinical scores than those with valgus.     

Erratum to “Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty” [The Knee 27(5) (2020) 1534–1541]”

BackgroundThe purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA).MethodsFifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique 3° angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman’s rank correlation analysis.ResultsIntraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS.ConclusionSurgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.     

Greater postoperative relatively medial loose gap at 90° of flexion for varus knees improves patient-reported outcome measurements in anatomical bi-cruciate retaining total knee arthroplasty

BackgroundThe purpose of the present study was to measure the intraoperative joint gap using tensor device and pre- and, postoperative joint stability at 0, 30 and 90° of flexion using stress radiography and to identify whether these factors influence patient-reported outcome measurement (PROM) in anatomical bi-cruciate retaining (BCR) knee arthroplasty (TKA).MethodsFifty-three knees with preoperative varus osteoarthritis of the knee underwent anatomical BCR TKA with oblique three-degree angle femorotibial joint line. The intraoperative medial and lateral joint gap using a tensor device and gap difference (lateral minus medial; varus laxity) were also calculated. Postoperative joint stability was measured using stress radiographs. PROM was also evaluated at 1.5 years postoperatively. The effect of intraoperative and postoperative joint stabilities on PROMs were analyzed using Spearman's rank correlation analysis.ResultsIntraoperative greater difference between medial joint gap at 140° and 0° of flexion showed significant positive correlation with postoperative function of patellofemoral joint. Intraoperative varus laxity at extension improved postoperative symptoms in 2011 Knee Society Score (2011 KSS); greater postoperative lateral stability at 30 and 90° of flexion with the varus stress test was associated with the better patient expectation in 2011 KSS. Postoperative medial laxity at 90° of flexion with the valgus stress test positively correlated with the patient expectation and satisfaction in 2011 KSS.ConclusionsSurgeons should notice that the postoperative lateral stability and medial laxity at 90° of flexion improved PROM in anatomical BCR TKA.     

Long-term clinical and radiological outcomes after multiligament knee injury using a delayed ligament reconstruction approach: A single-center experience

PurposeTo present long-term clinical and radiological results of patients treated with delayed reconstruction of multiligament knee injuries.MethodsClinical data from 26 patients (21 men, five women, mean age 27.44 years) were retrospectively reviewed. Patients were evaluated at final follow-up with the use of: The International Knee Documentation Committee score (IKDC), Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity level, Lysholm Knee Scoring Scale, EuroQol subjective knee evaluation form, and KT-2000 arthrometer. Mean follow-up time was 105.38 months. Both knees were radiographically evaluated for osteoarthritis according to the Kellgren–Lawrence classification.ResultsNo patient required mobilization under anesthesia for adhesion lysis at the immediate or later postoperative duration. There was no statistically significant difference in range of motion between the healthy and operated sides (P = 0.713). Mean time to final range of motion regain was 2.1 ± 0.4 months. Average KT-2000 side-to-side (operated vs. normal) difference was 2.03 ± 1.1 mm, and the difference was statistically significant (P = 0.007). The mean IKDC, KOOS, Lysholm, Tegner, and Euroqol-5D postoperative scores were 82.13 ± 17.5, 84.59 ± 16.8, 90.6 ± 6.4, 4.3 ± 1.3, and 80 ± 11.74, respectively. Multiple regression analysis showed that age and follow-up time had significant effects on each clinical score, except for the Lysholm and Tegner scores. Progression of osteoarthritic changes of the reconstructed knee and its contralateral side was significantly different (P = 0.003).ConclusionExcellent clinical results were reported from this center's long-term experience with delayed ligament reconstruction, and osteoarthritic changes of reconstructed knees were recorded.     

Rotational kinematics differ between mild and severe valgus knees in total knee arthroplasty

BackgroundThere is no consensus regarding femorotibial rotational kinematics in total knee arthroplasty (TKA) for valgus knee deformity. Additionally, whether the degree of valgus deformity influences intraoperative rotational kinematics and postoperative clinical scores remains unclear. The objectives of this study were to investigate whether the valgus angle is associated with intraoperative rotational kinematics in TKA for valgus knee deformity and to examine the relationship between rotational kinematics and postoperative clinical results.Materials and methodsA total of 24 knees with valgus deformity for TKA were included in this study and were divided into two groups depending on the femorotibial angle (FTA); there were 11 knees in the severe valgus group (FTA < 160°) and 13 knees in the mild valgus group (FTA ≥ 160°). Intraoperative femorotibial rotational kinematics from knee extension to flexion were evaluated using an image-free navigation system and postoperative clinical results (range of motion and subjective outcomes) were evaluated 1 year postoperatively. All parameters were compared between the two groups.ResultMild valgus knee showed tibial internal rotation during knee flexion before implantation, whereas severe valgus knee showed tibial external rotation during knee flexion before implantation. The postoperative flexion angle was positively correlated with the tibial internal rotation angle after implantation in the mild valgus group only.ConclusionIntraoperative rotational kinematics before implantation differed between mild and severe valgus knee deformity in TKA. Intraoperative tibial rotation influenced the postoperative knee flexion angle in mild, but not severe, valgus knee deformity. Ideal postoperative rotational kinematics may be different between the two groups and the difference may be taken into consideration in implant selections and surgical techniques.     

Improving the accuracy of tibial component placement during total knee replacement in varus knees with tibial bowing: A prospective randomised controlled study

BackgroundLateral tibial bowing leads to varus placement of the tibial component during total knee replacement in varus knees. Lateralised tibial jig placement can improve the accuracy of the tibial cut.MethodsA total of 227 patients (300 knees) undergoing total knee replacements were randomised into two groups. In the study group, the point of intersection of the distal tibial diaphyseal line at the tibial plateau drawn on long films was represented by zones. Knees with femoral bowing > 5° (28%) were excluded. Tibial jig placement on the proximal tibia was lateralised according to the zones. In the control group, the mid-point of the tibial plateau was taken as a reference. Femoral and tibial bowing, postoperative limb alignment and component placement were assessed.ResultsOf the 216 knees that were studied, 106 were in the study group and 110 in the control group. Bowing ≥ 3° had a significant positive correlation with lateralisation of the proximal tibial reference (p < 0.001). The Incidence of tibial bowing ≥ 3° was 57.33%. The mean postoperative hip–knee–ankle (HKA) angle was 178.31 ± 2.88° and 176.53 ± 2.88° (p < 0.001), whereas the mean medial proximal tibial angle (MPTA) was 89.91 ± 1.42° and 88.79 ± 1.72° (p < 0.001) in the study and control groups, respectively. Considering bowed tibiae alone, HKA angle and MPTA in the study group were 178.08 ± 2.81° and 89.72 ± 1.39° compared with 175.88 ± 2.87° and 88.38 ± 1.38° in the control group (p < 0.001).ConclusionThere is a high incidence of tibial bowing in varus knees. Lateralised tibial jig placement improved tibial component placement and postoperative limb alignment in total knee arthroplasty in varus knees with tibial bowing.