Varus Knee Osteoarthritis Research Articles

Opening-wedge high tibial osteotomy without bone grafting in severe varus osteoarthritic knee. Rate and risk factors of non-union in 41 cases.

Using locking plates in opening-wedge high tibial osteotomy (OWHTO) via a medial opening theoretically allows early weight-bearing without need for bone or bone-substitute grafting. It incurs a risk of non-consolidation in case of large correction (>10°), although rates and risk factors of non-union are not known. The present retrospective study compared OWHTO with correction <10° versus >10°, with a view to determining: (1) complications rates (non-union) according to degree of correction, and (2) risk factors for such complications. OWHTO with correction greater than 10° without graft shows normal consolidation and allows early weight-bearing. Forty-one patients treated by OWHTO for medial osteoarthritis of the knee between January 2101 and November 2015 were included in a retrospective study. HKA angle was assessed by long-leg axis radiographs, preoperatively and at 3 months. Clinical and radiological follow-up at 6 weeks, 3 months and 6 months assessed consolidation in terms of >40% filling of the osteotomy site. Partial (contact) weight-bearing was allowed from the first postoperative day, with full weight-bearing at 6 weeks. Mean patient age was 59±5 years. Mean body-mass index (BMI) was 30.3±5.2; 17 patients (41.5%) had BMI >30. Mean initial HKA angle was 173.5°±3° (range, 167-178°) and mean correction was 10.7°±2.7° (range, 5-15°). There were 27 corrections of 10° or more, and 14 less than 10°. At 3 months, mean HKA was 182.9°±2.5° (range, 178-187°). Twelve cases showed lateral tibial cortex fracture after opening. Thirty-six patients (87.8%) showed consolidation, at a mean 5±3 months. Five patients showed osteotomy site non-union; in all these cases, the lateral cortex was broken initially (P=0.003); all had BMI >30 (mean, 37.2±3.8; P<0.03); none were smokers. On univariate analysis, lateral tibial cortex fracture (OR=10; 95% CI, (1.59-196.30)), BMI >30 (OR=1.18; 95% CI, (1.03-1.41)) and correction ≥10° (OR=10.50; 95% CI, (2.49-53.86)) were associated with delayed consolidation. On multivariate analysis, only degree of osteotomy was significantly associated with delayed consolidation (OR=11.51; 95% CI, (2.13-95.74)). Obesity and initial lateral cortex fracture appeared as risk factors for non-consolidation of OWHTO with large correction. Systematic bone or bone-substitute grafting may therefore be considered in this population in case of >10° correction. IV, prospective cohort study.

Relationship between Lateral Femoral Bowing and Varus Knee Deformity Based on Two-Dimensional Assessment of Side-to-Side Differences.

PurposeThe objective was to evaluate the relationship between side-to-side differences of lateral femoral bowing and varus knee deformity based on two-dimensional (2D) assessment in unilateral total knee arthroplasty (TKA).Materials and MethodsA total of 143 patients with varus knee osteoarthritis who underwent unilateral TKA were enrolled. We evaluated the side-to-side differences of the frontal lower limb alignment by assessing lateral femoral bowing, anatomical medial distal femoral angle, and anatomical medial proximal tibial angle (aMPTA).ResultsThe average values of all anatomical indices were significantly different between the operated side and the non-operated side (p<0.05). The side-to-side difference in hip knee ankle (HKA) angle had a statistically significant correlation with that in lateral femoral bowing (intraclass correlation coefficient, 0.259; p=0.002) and that in aMPTA. Linear regression analysis showed 0.199° of side-to-side difference in lateral femoral bowing was associated with 1° of side-to-side difference in bilateral HKA angle.ConclusionsThe side-to-side difference in lateral femoral bowing showed a tendency to increase in proportion to varus knee deformity based on 2D assessment in unilateral TKA patients.

Combination of High Tibial Osteotomy and Autologous Bone Marrow Derived Cell Implantation in Early Osteoarthritis of Knee: A Preliminary Study.

High tibial osteotomy (HTO) is a recommended treatment for medial compartment knee osteoarthritis. Newer cartilage regenerative procedures may add benefits to the results of HTO. In this prospective study we have investigated the safety and also results of HTO associated with autologous bone marrow derived cells (BMDC) implantation in relatively young and middle aged active individuals with early osteoarthritis of the knee. A total of 24 patients (mean age of 47.9 years) with varus knee and symptomatic medial compartment osteoarthritis were treated with medial opening-wedge high tibial osteotomy in conjunction with implantation of bone marrow derived cells into the chondral lesions. The clinical outcomes were assessed by IKDC, KOOS, VAS, and Tegner scores. The radiographic studies were performed preoperatively and at follow-ups. No major complications were seen during the operations and postoperative follow-ups. All clinical scores were significantly improved for the IKDC score (from 32.7±15 to 64±21) (P<0.005), KOOS score (from30±11 to 68±19) (P<0.005), VAS (from 7.5 to 3) and Tegner score (from 1.2 to 2.1) (P<0.004). HTO in conjunction with BMDC implantation is a safe and feasible treatment and is associated with good results in short term follow up for early medial compartment osteoarthritis in varus knees.Level of evidence: IV.

Effects of posterior condylar osteophytes on gap balancing in computer-assisted total knee arthroplasty with posterior cruciate ligament sacrifice

ObjectiveGap planning in navigated total knee arthroplasty (TKA) is a critical concern. Osteophytes are normally removed prior to gap planning, with the exception of posterior condylar osteophytes of the femur, which are removed after posterior condylar resection. This study investigated how posterior condylar osteophytes affect gap balancing during surgery.MethodsThis prospective study was conducted on 40 primary varus osteoarthritic knees with a posterior condylar osteophyte that underwent TKA navigation. For all knees, computed tomography (CT) was performed to evaluate osteophyte position. The extension gap and flexion gap were determined under navigation using a tension device with a distraction force of 44 lb. The extension gap and flexion gap were measured before and after osteophyte removal.ResultsThis study revealed that the average osteophyte thickness after removal was 7.75 ± 5.34 mm. The average extension gap change was 0.64 ± 0.80 mm, and the average flexion gap change was 0.85 ± 1.12 mm. With respect to increases in the medial extension gap, lateral extension gap, medial flexion gap and lateral flexion gap, the average effects of posterior condylar osteophyte removal were 0.74 ± 0.81 mm, 0.53 ± 0.96 mm, 0.71 ± 0.97 mm and 1.00 ± 1.41 mm, respectively. Posterior condylar osteophyte thickness was also significantly associated with increases in the lateral extension gap (R2 = 0.107, p = 0.03), medial flexion gap (R2 = 0.101, p = 0.04) and lateral flexion gap (R2 = 0.107, p = 0.04).ConclusionThese results indicated that posterior condylar osteophytes of the femur affect gap balancing during TKA navigation.

Factors Associated With Posterior Cruciate Ligament Tightness During Cruciate-Retaining Total Knee Arthroplasty

BackgroundThe purpose of our study was to identify factors affecting posterior cruciate ligament (PCL) tightness during cruciate-retaining total knee arthroplasty. MethodsA total of 225 varus osteoarthritic knees that underwent cruciate-retaining total knee arthroplasty were included in this study. When the flexion gap was tighter than the extension gap after all bone resection and the lift-off sign was positive during surgery, the PCL was released. The association between PCL release and potential risk factors, such as age, gender, body mass index, preoperative range of motion, anterior cruciate ligament status, preoperative hip-knee-ankle angle (HKA), decrease in posterior condylar offset, and also change in tibial posterior slope angle (TPSA) from preoperative to postoperative measurement, was evaluated by univariate and multivariate logistic regression analyses. ResultsThe PCL was released in 68 of 225 knees (30.2%). According to the univariate logistic regression analysis, preoperative knee flexion angle (odds ratio [OR], 0.98), anterior cruciate ligament status (OR, 3.94), the decrease in medial (OR, 0.73) and lateral posterior condylar offset (OR, 0.76), preoperative HKA (OR, 1.1), preoperative (OR, 1.15) and postoperative TPSA (OR, 0.77), and the decrease in TPSA (OR, 1.23) were associated with PCL release. Multivariable stepwise logistic regression analysis demonstrated that preoperative HKA (P < .001), postoperative TPSA (P = .02), and the decrease in TPSA (P < .001) were independently associated with PCL release. ConclusionMany factors are associated with PCL tightness. The change in TPSA between preoperative and postoperative measurements was a higher risk factor than postoperative TPSA.

Analysis of the tibial baseplate coverage and symmetrical tibial prosthesis in primary total knee arthroplasty

Objective: To investigate the tibial baseplate coverage with symmnetrical tibial prosthesis in primary total knee arthroplasty (TKA). Methods: From August 2014 to February 2015, 39 patients (39 knees) with varus knee osteoarthritis were retrospective reviewed in Department of Orthopaedics, Tianjin Xiqing Hospital. Nine males and 30 females; aged 50 to 78 years (67±6 year). 3D tibia models of the knee were built with Mimics 10.01 software, simulated TKA surgeries were performed. The morphology of the proximal tibia was measured, including the mediolateral (ML), anteroposterior (AP) and medial and lateral tibial plateau AP dimensions. 3D models of PFC Sigma tibial prosthesis were imported and the tibial coverage characters were analyzed. Results: The AP and ML dimensions of the tibial resection surface were (45.7± 3.4) mm, (71.7± 4.2) mm respectively, the plateau aspect ration ratio (AP/ML) was 63.8%±3.0%. The medial tibial plateau AP[(46.9± 3.3) mm]was significantly greater than the lateral side[(41.8±3.3) mm, P=0.000], the asymmetric ratio averaged 112.4%±6.9%. The medial tibial plateau, anteromedial, posteromedial, posterolateral unsatisfied coverage ratio were 33.3%, 76.9%, 20.5%, 33.3% respectively. There are 5 cases underhang and 3 cases overhang in the posteromedial side, whereas 1 case underhang and 12 cases overhang posterolateral, the overhang ratio was 30.8%. Posteromedial, posterolateral prosthesis coverage had linear positive correlation to the ipsilateral tibial plateau AP diameter. Conclusions: The medial AP diameter of tibial plateau is significantly lager than the lateral side in varus knee osteoarthritis patients. With symmetrical tibial baseplate placement in TKA, the prosthesis usually lead to medial tibial plateau anterior and posterior underhang and posterolateral overhang.

Are varus knees contracted? Reconciling the literature.

There is direct literature conflict regarding coronal plane contracture or laxity in the end-stage varus osteoarthritic knee. Understanding the preoperative soft tissue status is important for optimizing the soft tissue envelope during total knee arthroplasty (TKA). The lower limb was manipulated using computer navigation, prior to surgical releases, to allow the limb weight-bearing axis to pass through the knee centre in maximum extension and 20° of flexion. Coronal plane laxity was measured in 78 varus (-7.7° ± 2.8°) knees as medial and lateral displacement from this point and compared to published values for healthy subjects. Medial contracture was present in 12.8% (10/78) of the knees. Of these 10 knees, 5 displayed abnormal lateral laxity. Knees with a contracture in maximum extension also displayed a significant decrease ( p < 0.0001) in medial laxity at 20° of flexion compared to non-contracted knees. In maximum extension, 19.2% (15/78) of knees had abnormally increased lateral laxity, 10 did not have a medial contracture. The remaining five knees with increased lateral laxity or 6.4% (5/78) of the total cohort also displayed a medial contracture. Lateral laxity increased significantly with increasing varus deformity. Medial laxity did not significantly decrease when comparing varus deformity of 5-10° versus >10°. The majority of varus knees with deformity of up to 15° have neither a medial contracture nor abnormal lateral laxity when referenced to the individualized neutral axis of the knee. Surgical releases during TKA should be uncommon. Medial contracture when present is influenced by both posterior and medial structures. Lateral laxity is a more consistent feature of the varus knee. The patterns of contracture and laxity are variable with limited correlation to deformity.

Varus knee osteoarthritis: Elevated synovial CD15 counts correlate with inferior biomechanical properties of lateral-compartment cartilage.

The study analyzed the influence of synovitis on the histological and biomechanical properties of lateral-compartment cartilage. In a prospective cohort study, 84 patients (100 knees) with varus deformity of the knee were included. Osteochondral samples from the distal lateral femur underwent biomechanical and histologic analysis. Synovial tissue was sampled for histological (chronic synovitis score) and immunohistochemical evaluation of the degree of synovitis. CD15 (neutrophils), Ki-67 (dividing cells), and CD68 (macrophages) were tested in all synovial samples. While the histological synovitis score did not correlate with the degree of cartilage degeneration (histological OARSI grades), both CD15 (rs = 0.297, p = 0.006) and Ki-67 (rs = 0.249, p = 0.023) correlated with histological OARSI grades. There was a weak negative correlation of CD15 with biomechanical properties of cartilage of the distal lateral femur (aggregate modulus (Ha): rs = -0.125; p = 0.257; dynamic modulus (DM): rs = -0.216; p = 0.048). No correlations were observed for Ki-67 and CD68. In addition, biomechanical properties were inferior in knees with a CD15 of >8/high power field compared to knees with a CD15 of ≤8/high power field (Ha: p = 0.031, d = 0.46; DM: p = 0.005, d = 0.68). The study demonstrates an association of increased inflammatory activity with advanced cartilage degeneration. Lateral-compartment cartilage in knees with elevated synovial CD15 counts has a reduced ability to withstand compressive loads. CD15 might serve as an indicator for inferior biomechanical cartilage properties. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:841-846, 2018.

Radiographic analysis of the lower limbs using the hip–calcaneus line in healthy individuals and in patients with varus knee osteoarthritis

BackgroundSeveral recent reports define the line from the centre of the femoral head to the lowest point of the calcaneus. The purpose of this study was to comparatively examine the usefulness of the hip–calcaneus (HC) line and hip–ankle (HA) line for the evaluation of lower-limb alignment in healthy individuals and in patients with osteoarthritis (OA). MethodsParticipants included 34 healthy individuals (mean age, 26.4years) and 34 patients with OA (mean age, 74.2years). Frontal radiographs of the entire lower limb were taken in single- and double-leg stances. For each group, the hip–knee–ankle (HKA) and hip–knee–calcaneus (HKC) angles were assessed and compared within and between stances. In addition, the HA line and HC line were assessed as the passing line in the knee, and were similarly compared. ResultsSignificant differences between the HKA and HKC angles, and between the HA line and HC line were observed in both groups during both stances. In addition, significant stance-related differences in the HKA and HKC angles, HA line, and HC line were found in the OA group, but not in the healthy group. ConclusionsOur results suggest that the HC line of the lower limb differs from the HA line. Furthermore, single- and double-leg stances should also be considered, especially in patients with OA. These considerations may affect preoperative planning for high tibial osteotomies and TKA.

Comparison of the outcome between unilateral and bilateral open wedge high tibial osteotomy in the bilateral varus osteoarthritic knee

Comparison of the outcome between unilateral and bilateral open wedge high tibial osteotomy in the bilateral varus osteoarthritic knee

High Varus Angle and Lower Posterior Tibial Slope Associated with PCL Injury in Cruciate Retaining Total Knee Arthroplasty: An MRI Study.

The posterior tibial slope (PTS) is important for performing a tibial cut that does not injure the posterior cruciate ligament (PCL). In this study, the amount of PCL fibers sacrificed under simulated tibial cuts with varying posterior inclinations was evaluated using magnetic resonance images (MRIs) of osteoarthritic varus knees. Knee X-rays, orthoroentgenograms, and MRIs of 113 Kellgren and Lawrence grades 3 to 4 osteoarthritic knees were included. Four different simulated tibial cuts were performed at 0, 3, 5 degrees and parallel to the tibia plateau 3 mm below of the most defective part of the cartilage in the medial plateau. Correlations between the PCL avulsion amount and the PTS and varus alignment of the lower extremity were analyzed for all four simulated tibial cut levels. The maximum amount of PCL was preserved with a 0-degree tibial cut in patients with a PTS of more than 8 degrees. With increased tibial cut angles, the posterior slope resulted in an increased amount of avulsed PCL. Although the amount of avulsed PCL was proportional with the varus alignment, it was inversely proportional with the sagittal slope. The number of injured PCLs also increased as the slope of the tibial cuts increased. Patients with mild varus alignments and high PTSs are more suitable for cruciate retaining total knee arthroplasty.

Expression of Sclerostin in medial and lateral subchondral bone of the varus osteoarthritic knee plateau

To study the expression difference of Sclerostin in the medial and lateral subchondral bone of the varus osteoarthritic knee plateau. The tibial plateau was obtained from 20 patients with varus knee osteoarthritis receiving total knee arthroplasty from March to October 2015. There were 8 males and 12 females with an average age of 67.8 years (range, 61-78 years). The mean course of osteoarthritis was 3.2 years (range, 2-5 years). Before operation, the varus angle was 12.0-25.5° (mean, 17.6°) on the X-ray film. Five cases were rated as grade III and 15 cases as grade IV according to Kellgren-Lawrance classification. Micro-CT scan was performed on the medial and lateral subchondral bone to compare the changes of bone structure; bone volume/total volume (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), structure model index (SMI), and the trabecular separation (Tb.Sp) were measured. Immunohistochemistry and real-time fluorescent quantitative PCR were used to test the expressions of Sclerostin protein and sost gene. Micro-CT showed that BV/TV, Tb.N, and Tb.Th significantly increased in the medial subchondral bone when compared with the lateral part ( P<0.05), but SMI and Tb.Sp significantly reduced ( P<0.05). Real-time fluorescent quantitative PCR detection showed that sost gene expression level in the medial subchondral bone (1.000) was significantly lower than that in the lateral part (4.157±2.790) ( t=2.371, P=0.040). The percentage of Sclerostin positive cells in the lateral subchondral bone (52.00%±0.19%) was significantly higher than that in the medial subchondral bone (7.20%±0.04%) ( t=5.094, P=0.005). Sclerostin plays an important role in the subchondral bone remodeling of the varus osteoarthritic knee. And the low expression of Sclerostin may be an important factor to promote bone remodeling and aggravate knee deformity.

External torsion in a proximal tibia and internal torsion in a distal tibia occur independently in varus osteoarthritic knees compared to healthy knees.

The relative torsional angle of the distal tibia is dependent on a deformity of the proximal tibia, and it is a commonly used torsional parameter to describe deformities of the tibia; however, this parameter cannot show the location and direction of the torsional deformity in the entire tibia. This study aimed to identify the detailed deformity in the entire tibia via a coordinate system based on the diaphysis of the tibia by comparing varus osteoarthritic knees to healthy knees. In total, 61 limbs in 58 healthy subjects (age: 54±18 years) and 55 limbs in 50 varus osteoarthritis (OA) subjects (age: 72±7 years) were evaluated. The original coordinate system based on anatomic points only from the tibial diaphysis was established. The evaluation parameters were 1) the relative torsion in the distal tibia to the proximal tibia, 2) the proximal tibial torsion relative to the tibial diaphysis, and 3) the distal tibial torsion relative to the tibial diaphysis. The relative torsion in the distal tibia to the proximal tibia showed external torsion in both groups, while the external torsion was lower in the OA group than in the healthy group (p<0.0001). The proximal tibial torsion relative to the tibial diaphysis had a higher external torsion in the OA group (p=0.012), and the distal tibial torsion relative to the tibial diaphysis had a higher internal torsion in the OA group (p=0.004) in comparison to the healthy group. The reverse torsional deformity, showing a higher external torsion in the proximal tibia and a higher internal torsion in the distal tibia, occurred independently in the OA group in comparison to the healthy group. Clinically, this finding may prove to be a pathogenic factor in varus osteoarthritic knees. Level Ⅲ.

Does Residual Varus Alignment Cause Increasing Varus Laxity at a Minimum of Five Years After Total Knee Arthroplasty?

BackgroundThe purpose of this study is to investigate whether varus-valgus laxity of cruciate-retaining (CR) total knee arthroplasty (TKA) changes between 1 year and >5 years after surgery based on postoperative limb alignment. MethodsOne hundred twenty-one varus osteoarthritic knees that underwent CR TKA were included. The minimum follow-up was 5 years. Weight-bearing full-leg radiographs were obtained postoperatively and the hip-knee-ankle (HKA) angle was measured. Knees were grouped in varus (HKA angle ≤ −3°, 47 knees) and neutral groups (−3° < HKA angle < 3°, 70 knees). The range of motion was measured and a Hospital for Special Surgery score was obtained at the last follow-up. Varus-valgus laxity at 15° of knee flexion was measured with stress radiographs after 1 year and at the last follow-up. ResultsNo knees required revision surgery. The mean knee flexion angle (121.0° vs 117.1°) and Hospital for Special Surgery score (90.3 vs 90.4) at the last follow-up were not significantly different between the varus and neutral groups. In both groups, there was no significant change in varus or valgus laxity between 1 year and at the last follow-up. ConclusionPostoperative residual varus limb alignment did not lead to increasing varus laxity after CR TKA in the mid-term.

The Posterior Condylar Cartilage Affects Rotational Alignment of the Femoral Component in Varus Knee Osteoarthritis.

Rotational alignment of the femoral component in total knee arthroplasty (TKA) is important for patellar tracking and ligament balance. Preoperative planning based on radiography might have a potential risk for over-rotation because these X-ray based measurements can not detect asymmetric cartilage wear on posterior condyle. The purpose of this study is to evaluate the effect of the posterior condylar cartilage of varus osteoarthritic knee on rotational alignment of the femoral component in TKA. We established two different condylar twist angles (CTA) from intraoperative multiplanar reconstruction (MPR) images and intraoperative information of navigation system. The CTA measured by a navigation system that includes the cartilage (4.8±2.0°) was smaller than those measured by MPR images, which does not include the cartilage (6.6±2.1°) (p<0.05). The difference between these two angles that corresponds to the remaining posterior condylar cartilage was 1.7±1.2°. This result demonstrated that the posterior condylar cartilage might lead to over-rotational of the femoral component in varus osteoarthritic knee. Therefore, when determining rotational alignment of the femoral component, surgeons should consider the effect of the remaining posterior condylar cartilage to avoid the over-rotation of the femoral component, especially in severe varus knees. J. Med. Invest. 64: 24-29, February, 2016.

Medial anterior flange overhang related to the prosthesis selection determined by femoral sizer in total knee arthroplasty

Objective: To evaluate the medial anterior flange overhang related to the femoral prosthesis size determined by femoral sizer in total knee arthroplasty. Methods: Sixty one cases of varus knee osteoarthritis (61 knees) were analyzed from January 2014 to January 2015, 14 males and 47 females, aged (66.8±6.8) year old. 3D models of distal femur were established by Mimics, total knee arthroplasty surgeries were simulated and the medial and lateral femoral condylar anteroposterior diameter were measured. According to the AP diameter of lateral femoral condyle (lateral condyle group) and femoral sizer (sizer group), different size of the PFC Sigma femoral prosthesis models were imported to mimics, and the coverage of medial anterior femoral flange were compared. Results: The AP diameter of lateral femoral condyle[(55.76±3.64) mm]was significantly less than the sizer group[(57.02±3.59) mm], P<0.05. The distal femur aspect ratio for male (1.2 %±0.1%) and female (1.2%±0.1%) has no statistically difference (P>0.05). Femoral prosthesis sizes, the uncoverage diameter of the anterior chamfer line, midpoint of the flange in the sizer group were significantly larger than the lateral condyle group (P<0.05). The femoral size, overhang ratio of anterior chamfer line and midpoint of the flange in male were significantly larger than females (P<0.05). Conclusion: The AP diameter determined by femoral sizer instrument had a tendency to larger prosthesis, and the risks of medial femoral anterior flange overhang increased. Medial anterior flange overhang in male was significantly less than female, but the difference had no correlation to the distal femur asepect ratio.

Distinctions of introarticular force distribution between genesis-II posterior stabilized and cruciate retaining total knee arthroplasty: An intraoperative comparative study of 45 patients

BackgroundAlthough both the posterior stabilized and cruciate retaining total knee arthroplasty have been proven to effectively relieve pain and restore basic functions, the joint gap width during flexion was reported to be different due to the presence or absence of posterior cruciate ligament, which may lead to different intra-articular force distribution. In this study, we investigated the distinctions in intra-articular force distribution between the two types of TKA designs in patients with varus knee osteoarthritis. MethodsForty five patients (50 knees) with varus knee osteoarthritis were prospectively included, with each 25 knees receiving cruciate retaining and posterior stabilized total knee arthroplasty, respectively. With an intra-articular force measurement system, the intra-articular force distribution with knee flexion at 0°, 30°, 45°, 60°, 90°, and 120° were recorded in all patients. FindingsThe total force was similar for posterior stabilized and cruciate retaining knees at all flexion degrees. However, force in the medial compartment accounted for 59.8%–84.0% of total force in posterior stabilized knees, while 27.4%–65.7% in cruciate retaining knees. In cruciate retaining knees, no significant difference was found between forces in the two compartments at 30° flexion (P=0.444), but force was significantly concentrated in the lateral side during 45°–120° flexion (P=0.000–0.028). InterpretationAlthough the entire intra-articular forces were similar between CR and PS knees at different flexion angles, medial part had higher force than lateral part when PS knee was used. The posterior cruciate ligament do a role in soft balance, and make the force more evenly distributed.

Radiographic assessment of knee–ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis

BackgroundThere are unanswered questions about knee–ankle alignment after total knee arthroplasty (TKA) for varus and valgus osteoarthritis (OA) of the knee. The aim of this retrospective study was to assess knee–ankle alignment after TKA. MethodsThe study consisted of 149 patients who had undergone TKA due to varus and valgus knee OA. The alignment and angles in the selected knees and ankles were measured on full-length standing anteroposterior radiographs, both pre-operatively and post-operatively. The paired t-test and Pearson's correlation tests were used for statistical analysis. ResultsThe results showed that ankle alignment correlated with knee alignment both pre-operatively and postoperatively (P<0.05). The pre-operative malalignment of the knee was corrected (P<0.05), and the ankle tilt angle was accordingly improved in the operative side after TKA (P<0.05). In addition, TKA had little effect on knee–ankle alignment on the non-operative side (P>0.05). ConclusionThese findings indicated that routine TKA could correct the varus or valgus deformity of a knee, and improve the tilt of the ankle. Ankle alignment correlated with knee alignment both pre-operatively and postoperatively. Both pre-operative knee and ankle malalignment can be simultaneously corrected following TKA. Level of evidenceLevel III.

Clinical and radiological results of double level osteotomy for varus knee osteoarthritis. Review of our experiences

Clinical and radiological results of double level osteotomy for varus knee osteoarthritis. Review of our experiences

Clinical Efficacy of an Arthroscopic Surgery in Open Wedge High Tibial Osteotomy.

Few studies have identified the effects of arthroscopic surgery on the clinical outcomes when open wedge high tibial osteotomy (OWHTO) and arthroscopic surgery were performed together. The purpose of this study was to evaluate the clinical efficacy of arthroscopic surgery in patients who had varus osteoarthritic knee and were treated with OWHTO combined with arthroscopic surgery. Among the 98 knees (88 patients) who underwent OWHTO between January 2008 and March 2013, 79 knees (71 patients) with more than 2 years of follow-up were reviewed retrospectively. The patients were divided into two groups: Group 1 (24 knees) underwent only OWHTO and Group 2 (55 knees) underwent OWHTO combined with arthroscopic surgery. For clinical evaluation, the range of motion (ROM), pain visual analog scale, Knee Society knee score, Knee Society function score, and complication were used. For radiologic evaluation, Kellgren-Lawrence grade, mechanical femorotibial angle, and posterior tibial slope were used. The average follow-up period was 29.1 months. Group 2 showed a significant increase in the ROM at the last follow-up (133.2 ± 6.0 degrees) compared with the preoperative time point (128.3 ± 7.7 degrees) (p < 0.001). In the comparison of radiologic parameters between Groups 1 and 2, there was no significant difference. In the minimum 24-month follow-up, when OWHTO combined with arthroscopic surgery was performed, arthroscopic surgery helped increase the ROM of patients with mechanical symptoms. However, the amount of the ROM increase of 4.9 degrees was of unknown clinical significance.