Introduction. Total knee arthroplasty (TKA) is an effective surgical intervention, which alleviates pain and improves function and health-related quality of life in patients with end-stage arthritis of the knee joint. With improvements in anesthesia, general health care, and surgical techniques, this procedure has become widely accepted for use in very elderly patients. However, many elderly patients tend to have compromised function and low reserve capabilities of organs and are therefore likely to develop various complications during the perioperative period. Thus, elderly patients often hesitate to undergo simultaneous bilateral TKA (SBTKA). Our purpose was to report the short-term results and clinical complications of octogenarians undergoing SBTKA. Materials and Methods. Between 2015 and 2016 all patients greater than 80years of age who underwent SBTKA by a single surgeon were retrospectively evaluated demographics, comorbidity, complications, and 30days mortality following SBTKA. Arthroplasty was performed sequentially under general anesthesia by one team led by primary surgeon. After the first knee, the patient's cardiopulmonary status was assessed by anesthesiology to determine whether or not to begin the second side. Cardiopulmonary decompensation, such as significant shifts in heart rate, oxygen saturation or blood pressure, was not showed. Then the second procedure was undertaken. Inclusion criteria of this study was underlying diseases were osteoarthritis. Exclusion criteria were (1) previous knee surgery; (2) underlying diseases were osteonecrosis, rheumatoid arthritis, fracture, and others. Fifty-seven patients with an average age of 82.7years were identified. The results of these procedures were retrospectively compared with those of patients greater than 80years of age of 89 patients unilateral TKA (UTKA) that had been performed by the same surgeon. Results. The study groups did not differ significantly with regard to age, gender, or body mass index. The mean age was 82.7years with a mean body mass index of 25.8 for the SBTKA group, compared with 84.0years with a mean body mass index of 24.9 for the UBTKA group. The length of hospital stay was longer in SBTKA groups. There was no serious complication. No deaths, no pulmonary embolisms and no nerve paralysis occurred within 30days in both groups. There was one wound problem in SBTKA group, compared 10 wound problem in UBTKA group; this difference was significant. Three deliriums occurred in SBTKA group, compared 13 deliriums in UBTKA group; this difference was significant. Minor complications included urinary tract infection, decubitus ulcer, transfusion reaction and ileus were noted seven in SBTKA group, compared in 11 UBTKA group; this difference was not significant. Conclusions. Complications and mortality are not higher for SBTKA compared to UTKA, SBTKA can be a safe and effective option for octogenarians

Introduction. Although total knee replacement became a widespread procedure for the purpose of knee reconstruction, osteotomies around the knee were regularly performed. Total knee arthroplasty should be performed for advanced arthritis of the knee. With the advent of biplanar open wedge high tibial osteotomy (HTO) combined with locking plate fixation, HTO has been expanded and its surgical outcome has been improved in recent years. However, post-operative joint-line obliquity has been raised as a concern with this procedure, which may affect the outcome especially in the knees with severe varus deformity. Hence the purpose of this study is to analyze the compression and shear stresses in the knee cartilage with joint line obliquity after HTO. Methods. Using a three-dimensional computer aided design software, the digital knee model with soft tissues was developed. The geometrical bone data used in this study were derived from commercially available human bone digital anatomy media (3972 and 3976, Pacific Research Laboratories, Inc., WA, USA). The three-dimensional knee model was transferred to finite element model. Material properties of the soft tissues and bones were derived from previous studies. The loading condition was adjusted to the load during a single-leg stance of the gait cycle, which resulted in an axial compressive load of 1200 N. Two different conditions were subjected to the analysis: normal alignment and joint-line obliquity after HTO. For the normal alignment, a static force of 1200 N was applied along the mechanical axis. For the joint-line obliquity models, a single force of 1200 N was applied rotating force directions in the frontal plane from the normal direction by 2.5º, 5º, 7.5º, and 10º, respectively. Results. The maximum values of the axial stresses in the cartilages for the normal condition showed almost same values in medial and lateral compartments. In the joint-line obliquity models, the maximum axial stress values in the medial compartment did not exhibit substantial change up to the level of 7.5º obliquity, while a rise in maximum stress value was observed for the model with 10º obliquity. The shear stress showed a different tendency. In the joint-line obliquity models, a steep rise of laterally directed shear stress in the medial compartment was observed for models with obliquity of 5º or more. Discussion. The shear stress in the medial cartilage increased to almost twice as high as the normal knee level for the joint- line obliquity model with an inclination of 5º. The maximum shear stress values increased in accordance with the obliquity angle. The elevated stress could be deleterious to the cartilage. In such large amount of correction by tibial osteotomy leads to unfavorable mechanical environment in the knee. For those severe situations, double-level osteotomy, which retains anatomical knee joint line by simultaneous femoral and tibial osteotomies, should be considered to correct the joint-line obliquity

Introduction. Stryker computer navigation system has been used for total knee arthroplasty (TKA) procedures since October 2008 at the Russian Ilizarov Scientific Centre for Restorative Traumatology and Orthopaedics. Material and methods. There have been 126 computer assisted TKA that accounted for 11.5 % of primary TKA within this period (1096 procedures). Arthritis of the knee joints with evident pain syndrome was an indication to TKA surgery. Arthritis of the knee joint of 27 patients (21.4 %) was accompanied by femoral deformity of various etiology with debris found in the medullary canal in several cases. The rest 99 patients (78.6 %) were regular cases of primary TKA. Results. We compared the results of correction of lower limb biomechanical axis with TKA employing navigation and without computer assistance. Regular TKA procedures showed no substantial difference in the correction of biomechanical axis. Complete correction using computer navigation was achieved in 85 % of the cases versus 79 % of the patients without navigation. The deformity up to 3° developed in 14 % of navigated cases and in 17 % of the cases without computer assistance. An error of deformity correction was 3–5° in 4 % of the cases without computer navigation. Those were cases of challenging primary TKA. So the advantages of computer navigation have become evident with greater deformities, and in the cases when intramedullary guide can hardly be used due to severe deformities in the femoral metaphysis and diaphysis, after several operative procedures of osteosynthesis with deformed, obliterating bone marrow canal or presence of debris. Complete correction using computer navigation was achieved in 85.2 % cases versus 42.8 % patients without navigation. Postoperative varus of 2° was observed in 14.8 % cases (valgus or varus deformity of 3° developed in 28.6 % of the cases without computer assistance). Conclusion. What is better: special instrumentation or navigation?. Current instrumentation can provide regular mechanical control of the limb axis and is based on the principles of intramedullary, extramedullary and even double guide placement. Image-free navigation and standard surgical techniques can equally be used for simple cases of primary TKA. Same landmarks are used. These landmarks are determined by a surgeon quite subjectively and can lead to inadequate usage of special instrumentation and computer navigation. However, computer navigation should be used in the cases when intramedullary guide can hardly be used, not desirable or possible. Special instrumentation can fail in setting a valgus angle needed with extraarticular femoral deformity. Navigation allows determining rotation more precisely in the cases when posterior femoral condyles contour (posttraumatic condition, hypoplastic condyles) is distorted. Assessment of ligament balance can be rather subjective when special instrumentation is used. Application of computer navigation is helpful for measurements of flexion and extension gaps sixe and regularity. Computer navigation is contraindicated for contractures and ankyloses of the hip joint. For the rest of the cases the choice of instrumentation is a surgeon's decision

The lifetime prevalence of symptomatic osteoarthritis at the knee is 50% osteoarthritis of the ankle occurs in only 1% of the population. This variation in prevalence has been hypothesised to result from the differential responsiveness of the joint cartilages to catabolic stimuli. Human cartilage explants were taken from the talar domes (n=12) and the femoral condyles (n=7) following surgical amputation. Explants were cultured in the presence of either a combination of high concentration cytokines (TNFα, OSM, IL-1α) to resemble a post traumatic environment or low concentration cytokines to resemble a chronic osteoarthritic joint. Cartilage breakdown was measured by the percentage loss of Sulphated glycosaminoglycan (sGAG) from the explant to the media during culture. Expression levels of the pro-inflammatory molecules nitric oxide and prostaglandin E. 2. were also measured. Significantly more sGAG was lost from knee cartilage exposed to TNFα (22.2% vs 13.2%, P=0.01) and TNFα in combination with IL-1α (27.5% vs 16.0%, P=0.02) compared to the ankle; low cytokine concentrations did not affect sGAG release. Significantly more PGE. 2. was produced by knee cartilage compared to ankle cartilage however no significant difference in nitrite production was noted. Cartilage from the knee and ankle has a divergent response to stimulation by pro-inflammatory cytokines, with high concentrations of TNFα alone, or in combination with IL-1α amplifying cartilage degeneration. This differential response may account for the high prevalence of knee arthritis compared to ankle OA and provide a future pharmacological target to treat post traumatic arthritis of the knee

Bilateral simultaneous total knee replacement surgery remains controversial with arguments for and against its use. Doing sequentially staged TKR's is a safer procedure and may have additional benefits as set out below. If both knees need to be replaced we have often seen that the symptoms of the contralateral knee improve after the one knee is replaced and that patients wait some time before having the opposite knee replaced. Materials:. 333 of 2084 patients having primary total knee replacements needing bilateral replacements were reviewed retrospectively. Results. 245 patients were seen initially with bilateral arthritis of the knee and needed bilateral TKR, while 88 patients developed arthritis in the contralateral knee following TKR. No patients had simultaneous bilateral TKR's; operations were done sequentially and the average time between the TKRs was 20.77 months with a range between 1.5–111 months. Most patients had the contralateral knee replaced within two years of the first knee replacement but 81 patients actually waited between 2 and 10 years before coming in for the second TKR. Conclusion:. It is possible to wait some time before it becomes necessary to replace the contralateral knee in patients who need bilateral TKRs and avoid the increased risk of bilateral simultaneous surgery. The delay not only reduces the cost for the first operation but also gives the second knee a longer time to failure. This is especially important in the typical patients who qualify for bilateral simultaneous TKR's i.e. the younger fitter patients

Total knee arthroplasty (TKA) is reliable, durable, and reproducible in relieving pain and improving function in patients with arthritis of the knee joint. Cemented fixation is the gold standard with low rates of loosening and excellent survivorship in several large clinical series and joint registries. While cementless knee designs have been available for the past 3 decades, changing patient demographics (i.e. younger patients), improved implant designs and materials, and a shift towards TKA procedures being performed in ambulatory surgery centers has rekindled the debate of the role of cementless knee implants in TKA. The drive towards achieving biologic implant fixation in TKA is also driven by the successful transition from cemented hip implants to uncemented THA. However, new technologies and new techniques must be adopted as a result of an unmet need, significant improvement, and/or clinical advantage. Thus, the questions remain: 1) Why switch; and 2) Is cementless TKA more reliable, durable, or reproducible compared to cemented TKA?. There are several advantages to using cement during TKA. First, the technique can be universally applied to all cases without exception and without concerns for bone health or structure. Second, cement can mask imprecisions in bone cuts and is a remarkably durable grout. Third, cement allows for antibiotic delivery at the time surrounding surgery which has been shown in some instances to reduce the risk of subsequent infection. Finally, cement fixation has provided successful and durable fixation across various types knee designs, surface finishes, and articulations. On the other hand, cementless knee implants have had an inconsistent track record throughout history. While some have fared very well, others have exhibited early failures and high revision rates. Behery et al. reported on a series of 70 consecutive cases of cementless TKA matched with 70 cemented TKA cases based on implant design and demographics and found that cementless TKA was associated with a greater risk of aseptic loosening and revision surgery at 5 years follow up. Finally, to date, there has not been a randomised controlled clinical trial demonstrating superiority of cementless fixation compared to cemented fixation in TKA. Improvements in materials and designs have definitely made cementless TKA designs viable. However, concerns with added cost, reproducibility, and durability remain. Cement fixation has withstood the test of time and is not the main cause of TKA failure. Therefore, until there is significant data showing that cementless TKA is more durable, reliable, and reproducible compared to cemented TKA, the widespread use of these implants cannot be recommended

An outpatient TKA program was developed by integrating advances in analgesia, rehabilitation, and minimally invasive surgical techniques with the objective of improving value in elective total knee arthroplasty (TKA) while maintaining quality standards. Previous studies have established the safety of outpatient TKA in selected populations, but the literature is devoid of outcome measures in these patients. Our goal was to investigate the quality of recovery, patient satisfaction, and safety profile in the first 90 days undergoing outpatient TKA. One hundred TKAs in 93 consecutive patients with end-stage arthritis of the knee candidate for primary TKA were enrolled in this prospective matched cohort study. Patients that underwent inpatient TKA (47 TKAs) were compared with patients that underwent planned outpatient TKA (53 TKAs). The following 28 day post-operative scores were recorded: quality of recovery (QoR-18) and pain scores by Numerical Rating Scale (NRS-11). Satisfaction with pain control (0 to 10) and quantity of opioid use was collected. Secondary outcome measures of 90-day complications, readmissions, and emergency department (ED) visits were recorded. Ninety-six percent of patients planned for outpatient TKA met our defined multidisciplinary criteria for same-day discharge. QoR-18 at post-operative day one was statistically higher in the outpatient TKA group. Otherwise, outcome measures were not statistically different between the 2 groups. Two patients required overnight admission: 1 for extended motor-block and 1 for vasovagal syncope. There were 7 ED visits in the in the outpatient group and 4 in the inpatient group. One outpatient was admitted for irrigation and debridement with liner exchange for an acute infection 2 weeks post-operatively. One inpatient required manipulation under anesthesia at six weeks post-operatively. Outpatient TKA in selected patients produced a post-operative quality of recovery and patient satisfaction similar to that of inpatient TKA. Our results support that outpatient TKA is a safe alternative that should be considered due to its potential cost-savings and comparable recovery

Introduction. Total knee arthroplasty (TKA) is a successful procedure for end stage arthritis of the knee that is being performed on an exponential basis year after year. Most surgeons agree that soft tissue balancing of the TKA is a paramount to provide a successful TKA. We utilized a set of retrieved lower extremities with an existing TKA to measure the laxity of the knee in all three planes to see if wear scores of the implants correlated to the laxity measured. This data has never been reported in the literature. Methods. IRB approval was obtained for the local retrieval program. Each specimen was retrieved after removing the skin, subcutaneous tissue and muscle from mid thigh to mid tibia. The femur, tibia and fibula were then transversely cut to remove the specimen for testing. Each specimen was then imaged using a flouroscopic imaging unit (OEC, Inc) in the AP, Lateral and sunrise views. These images were used to analyze whether there were any signs of osteolysis. Each specimen was mounted into a custom knee testing machine (Little Rock AR). Each specimen then was tested at full extension, 30, 60, and 90 degrees of flexion. At each flexion angle the specimen was subjected to a 10Nm varus and valgus torque, a 1.5Nm internal and external rotational torque and a 35N anterior and posterior directed force. Each specimen's implants were removed to record manufacturer and lot numbers. Polyethylene damage scores (Hood et al. JBMR 1983) were then calculated in the medial, lateral and backside of the polyethylene insert as well as on the medial and lateral femoral condyle. (Figure 1) Correlation coefficients were then calculated to show any relationship with soft tissue balancing in all three planes and wear scores. Results. No correlation > 0.4 existed for any surface damage on the polyethylene or femoral condyle to laxity in any plane (Figure 2). The highest correlations were found with backside wear (0.5) to internal and external rotational laxity. Two thirds of the specimens had more varus than valgus laxity in the coronal plane (p=0.03). Discussion/Conclusion. This is the first report of necropsy obtained retrievals where the soft tissue laxity of the knee was recorded. Although small numbers with different implant types the data shows that limited correlation exists between implant surface damage and increased laxity. The strongest correlation we found was backside wear to transverse plane laxity in flexion and extension, but this most likely is related to locking mechanism design. It seems in this set of implants that the soft tissue laxity did not affect implant bone interfaces as all were over 10 years from surgery. For figures/tables, please contact authors directly.

Bi-cruciate-retaining (BCR) total knee arthroplasty (TKA), which retains both the anterior (ACL) and posterior cruciate (PCL) ligaments, serves as an alternative to the traditional TKA procedure. Despite the difficulty of ensuring the structural integrity of the prosthesis, the BCR TKA can yield improved patient outcomes such as range of motion, kinematics, and even the survivorship of the implant. When possible, BCR TKA can and should be considered as a viable option to treat end-stage arthritis of the knee. Reconsidering the frequency of the BCR TKA is necessary for several reasons. Patient outcomes following BCR TKA are similar to outcomes for mobile-bearing UKA. Patients with an intact ACL do better with preservation (UKA or BCR TKA) of the ACL. The corollary is also true that removing an intact ACL at the time of arthroplasty has worse outcomes than traditional TKA in patients with an absent ACL. Reported outcomes of BCR TKA include more normal knee function, excellent prosthetic survivorship, and greater patient satisfaction. The BCR TKA may provide a missing link in the continuum of constraint for primary knee arthroplasty. Many early BCR designs fell out of favor because of high rates of prosthetic loosening, and because the procedure was more technically demanding than that of highly successful ACL-sacrificing TKA devices. Recently there has been a reemergence of the BCR arthroplasty concept with improvements in design. By retaining both the ACL and PCL, BCR TKA patients show more normal knee function and flexibility due to anterior stability and replication of the physiological tension in the ACL. Modern BCR TKA models have improved upon early designs but are limited in use mainly due to the lack of an optimal prosthesis design and the relative difficulty of the surgical procedure. Bi-cruciate-retaining TKA is a viable procedure if an appropriate femorotibial gap can be created to mimic physiological tension of the ACL and PCL. In terms of the surgical technique, the procedure begins with femoral preparation to facilitate tibial preparation. Distal femoral resection is performed first taking care to avoid damage to the ACL. Femoral preparation is then completed with a four-in-one guide that incorporates a protector to ensure the ACL is not resected. Good exposure is essential to tibial preparation, which is the critical part of the procedure and involves several steps of setting the depth of resection, and making accurate cuts to protect the tibial eminence island of bone and set tibial component rotation. The medial and lateral tibial cuts must be absolutely parallel. Precise cement technique is required for the tibial baseplate, and care must be taken when trialing the dual bearings. Normal kinematics are preserved when both the ACL and PCL remain intact. Bi-cruciate-retaining TKA knees have been shown to restore more normal kinematics and have better “feel” than traditional ACL-sacrificing TKA knees. Bilateral TKA patients with designs of both types prefer their BCR TKA to their ACL-sacrificing TKA more often than not. An intact ACL has been shown to be present in 60–80% of arthritic knees, further justifying the consideration to retain both cruciate ligaments during TKA. New materials and refined instrumentation and techniques have helped improve the viability of BCR TKA, which may represent an additional option in the continuum of constraint for knee arthroplasty

Background. Open-wedge high tibial osteotomy (OWHTO) is an operation involving proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. Therefore, stable fixation is mandatory for safe healing of this additive type of osteotomy to minimize the risk of non-union and loss of correction. For stability, screws provide optimal support and anchorage of the fixator in the condylar area without risking penetration of either the articulating surface. The purpose of the study was to evaluate the screw insertion angle and orientation with an anatomical plate that is post-contoured to the surface geometry of the proximal tibia after OWHTO. Methods. From March 2012 to June 2014, 31 uni-planar and 38 bi-planar osteotomies were evaluated. Postoperative computed tomography data obtained after open wedge high tibial osteotomy using a locking plate were used for reconstruction of the 3 dimensional model with Mimics v.16.0 of the proximal tibia and locking plate. Measurement data were compared between 2 groups (gap lesser than or equal to 10 mm (Group 1) and gap greater than 10 mm(Group 2)). These data were also compared between the uniplanar (Group 3) and bi-planar (Group 4) osteotomy groups. Result. The dimensions of ‘L1’, ‘L2’, and ‘a’ were not statistically different, regardless of the correction degree and operative technique. Also, X1 and X3 were not statistically different, regardless of the correction degree and operative technique. In the axial plane, the angles ‘A_θ1, A_θ2, A_θ3, and A_θ4’ of screw insertion to the lateral hinge point were not statistically different, regardless of the correction degree and surgical technique(Figure 1). Also, the angles ‘C_θ1, C_θ2, C_θ3, and C_θ4’ of screw insertion to the lateral hinge point were not statistically different in the coronal plane, regardless of the correction degree and surgical technique in the coronal plane(Figure 1). Angles of screw insertion, based on quantitative assessment of the tibial bony surface to the lateral hinge point were larger at the A_θ1 and A_θ4 than A_θ2 and A_θ3 in the axial plane. Angle of the C_θ1 was smallest in the coronal plane and it was less than 90°. Angles of C_θ2, C_θ3, and C_θ4 were larger than 90°(Table 1). Discussion & Conclusion. Dimensions of the medial proximal tibia of the sagittal plane, positions of the screw hole in the sagittal plane, and angles of screw insertion of all planes were not statistically different, regardless of the correction degree and operative technique. Additionally, angles of screw insertion were larger at the most anterior and posterior screw in the axial plane and most inferior screw showed smallest angle in the coronal plane. Using a post-contoured plate, the position and angle of the screw insertion were not different in the direction of the lateral hinge, regardless of the correction degree and operative technique. In our study, we evaluated the coronal insertion angle with targeting the lowest portion of the safe zone. Therefore, most screws of the proximal fragment could be inserted in the superior oblique direction if they are targeted to the ‘Safe Zone’. For any figures or tables, please contact authors directly (see Info & Metrics tab above).

INTRODUCTION. Although the most commonly used method of femoral component alignment in total knee arthroplasty (TKA) is an intramedullary (IM) guides, this method demonstrated a limited degree of accuracy. The purpose of this study was to assess whether a portable, accelerometer-based surgical navigation system (Knee Align 2 system; Orth Align, Inc, Aliso Viejo, Calif) improve accuracy of the post-operative radiographic femoral component alignment compared to conventional IM alignment guide. MATERIALS & METHODS. Since February 2014, 44 consecutive patients (39 female, 5 male) with primary arthritis of the knee were enrolled in this prospective, randomized controlled study. 24 patients underwent TKA (Vanguard RP or PS, Biomet Japan) using the navigation device for the distal femoral resection (Navigated Group), and 20 patients with conventional femoral IM alignment guide. The proximal tibial resection was performed using an extramedullary guide. All the operation was performed by a single senior surgeon (YK) with the same gap balancing technique except for the use of the navigation system for the femur. Accuracy of femoral implant positioning was evaluated on 2 weeks postoperative standing anteroposterior (AP) hip to ankle radiographs. RESUTS. In the navigated group, 100% of patients had an alignment within 90 ± 3° to the femoral mechanical axis in the coronal plane, versus 90.0% in the IM guides cohort (Fig). The mean absolute difference between the intraoperative goal and the postoperative alignment was 0.79 ± 1.0° in the Knee Align 2 cohort, and 1.72 ± 1.6° in the IM guides cohort (P < 0.05). There was a difference in the standard deviations observed for the navigated cases and the conventional cases when femoral component position was considered. There were no technique specific complications associated with the navigation system. DISCUSSION & CONCLUSION. The distal femoral resection has been the main source of error as for the neutral mechanical axis because of the difficulty in visualization and detection of the center of the femoral head. The results in the current study have shown that a portable, accelerometer-based navigation device (Knee Align 2 system) significantly decreases outliers in femoral component alignment compared to conventional IM alignment guides in TKA

Introduction. Open wedge high tibial osteotomy (OWHTO) is an operation by the proper load re-distribution in the treatment for medial uni-compartmental arthritis of the knee joint. However, for the proper load re-distribution, stable fixation is mandatory. For the stable fixation, plate should be contoured to the bony surface and screws should be inserted from the central area of the medial side to the hinge area of the lateral side in the proximal fragment because most failures occur at the relatively lesser supported lateral hinge area. Therefore, the purpose of this study was to evaluate the screw insertion angle and orientation that is inserted to the direction of the lateral hinge with an anatomical plate that is post-contoured with a surface geometry of the proximal tibia after the OWHTO. The hypothesis of this study was that the position and orientation would be different according to the correction degree (median value 10 mm) and surgical technique (uni-planar vs bi-planar). Materials and Methods. Thirty-one uni-planar and thirty-eight bi-planar osteotomies were evaluated. Postoperative CT data obtained after OWHTO were used for the 3D reconstruction of the proximal tibia. Anterior dimension (L1) and posterior dimension (L2) of the proximal tibia were measured in sagittal plane from tibial spine. Screw insertion points using four holes were even distributed using L1 and L2 value. As screw insertion angle was set from four holes to lateral hinge of the ‘Safe Zone’. Those four angles were measured in the axial and coronal plane. These were compared according to the correction degree and surgical technique. Results. Anterior AP dimension ‘L1'and posterior AP dimension ‘L2'were measured 24.0 ± 3.7 mm, 22.6 ± 3.1 mm. Angulations of screw from respectively screw hole to lateral hinge were measured 11.3 ± 1.7°, 3.5 ± 1.3°, 3.1 ± 1.5°, and 9.5 ± 1.1° in the axial plane and 81.5 ± 6.0°, 101.5 ± 2.6°, 90.8 ± 3.7°, and 99.2 ± 2.8° in coronal plane, respectively. None of the comparisons were statistically different, regardless of the correction degree and operative technique (Table1). Conclusions. Range of screw angulation showed regular pattern according to the site of the screw hole and it was not different, regardless of the correction degree and operative technique. This study provided range of the screw angulation by the anatomical surface modeling. Future study would give additional benefit for the optimal screw angle and stability such as finite element analysis or other methods

Introduction. Total Knee Arthroplasty (TKA) is highly successful in treatment of end-stage degenerative arthritis of the knee. CT-based Patient-Specific Instrumentation (PSI) utilizes a CT scan of the lower extremity to create a three-dimensional model of the patient's anatomy, plan the surgery, and provide unique patient-specific resection blocks for the surgery. There are few published studies utilizing CT-PSI. The present study prospectively evaluates clinical, operative, and radiographic outcomes from 100 CT-based TKAs using this technology (MyKnee®, Medacta International S.A., Castel San Pietro, Switzerland). Materials and Methods. 100 consecutive eligible knees (94 patients) of the senior author underwent TKA using CT-based PSI technology. The primary outcome of the study was to compare the planned pre-operative femoral and proximal tibial resections to the actual intra-operative measured resections. Clinical outcomes included pre- and post-operative Knee Society Scores, Range-of-Motion (ROM, measured by goniometer), and complication data. Pre- and 6-week post-operative long-leg standing radiographs were obtained to assess HKA alignment. The femoral component angle (FCA) in the coronal plane, the tibial component angle (TCA), and posterior slope of the tibia were also assessed. Additionally, 10 patients were selected at random to undergo a post-operative CT scan for comparison to radiographic measurements. Results. 94 patients were enrolled representing 51 left and 49 right TKAs. Average follow up was 3.9 years (range 3.5 – 4.4 years). Average Knee Society Score (KSS) improved from 44.3 to 81.8 while KSS Function Score improved from 59.1 to 81.8 at 1 year. ROM arc of the patients was 110.5 (range 0–130) pre-operatively and was 111.3 (range 0–130) post-operatively. Two patients had a post-operative infection requiring surgical intervention. There were no thromboembolic complications and no revisions in study patients. No patient required a manipulation under anesthesia for post-operative stiffness. No intraoperative complications occurred nor were there any cases of abandoning the PSI blocks for standard technique. The actual bony resections achieved during surgery were strongly correlated to the planned resections of all 6 bone fragments measured. Each achieved statistical significance (p<0.001). Average post-operative alignment was 179.36° (range 175°–186°). Alignment was 180 ± 3° in 94% of patients post-operatively. Ten patients underwent a post-operative CT scan for HKA verification. The average post-operative HKA was 179.9° (range, 176.9°–180.9°) with a standard deviation of 1.31°. When comparing our pre-operative alignment by x-ray vs. CT, we found only 0.09° (p<0.001) average difference between them. Post-operatively, we continued to show very similar results showing x-ray HKA measurement of 180.1° vs. CT measurement of 179.9° (p<0.001). Discussion. The pre-operative CT reconstruction can accurately predict the intra-operative resection depths as demonstrated here. All 6 bony resections measured to within 1mm of the predicted value in the aggregate of our series. The restoration of mechanical axis to 179.9° as measured by CT scans demonstrates the efficacy of the blocks. Conclusion. The present study demonstrates efficacy in the use of CT-based PSI - showing that the planning can accurately predict bony resections, be used safely, and achieve precise radiographic outcomes. Consequently, we routinely support the use of CT-based PSI in TKA

Total knee replacement (TKA) surgery is an excellent and well-proven procedure for the treatment of end stage arthritis of the knee. Many refinements have taken place over time in an attempt to improve the components, wear qualities of the polyethylene, and the surgical technique to improve accuracy of component positioning, reduce patient pain, improve postoperative range of motion, ultimately improve results and to prolong the time until revision surgery may occur. This study examines the results of a gap balancing surgical technique in which components were implanted that had a posterior cruciate substituting design. This technique is performed with exacting alignment and balancing of the flexion and extension gaps prior to implantation of the knee components. The follow up is at a minimum of ten years. 515 consecutive knee replacements were followed prospectively for a minimum of ten years. The average age at surgery was 70 years, 73% of patients were female, with an average BMI of 31. All patients carried a diagnosis of osteoarthritis and a cemented, posterior stabilized design TKA (Balanced Knee System, Ortho Development) was implanted. All cases were performed by one of two experienced joint replacement surgeons. The surgical technique demanded flexion and extension gap balancing as well as soft tissue balancing prior to finishing cuts being performed on the femoral side (See figures 1 and 2). Polyethylene spacers come in 1 millimeter increments. 28% of patients died postoperatively at an average of 7.4 years. These patients were older on average at the time of index surgery (76.6 years). None had undergone revision surgery. Of the remaining patients Knee Society scores (39 preop to 91 post op at ten years), function scores and range of motion all improved significantly. What's more, these results were not diminished at ten years. There were no component failures and less than 1% radiographic progressive lucent lines. Eleven revision surgeries (2.1 %) were performed with 2 acute superficial wound revisions, 3 late infections, one patellar tendon disruption from a fall at 7 years (BMI 45.7), 2 complete revisions performed elsewhere for unsatisfactory results, and 3 spacer exchanges for perception of postoperative laxity. For the current study we also examined subgroups of the morbidly obese, octogenarians, and those with a preoperative valgus deformity of greater than 15%. At follow-up these subgroups fared very well with the exception of the heaviest BMI's being limited in range of motion because of soft tissue impingement. Results suggest that this balancing technique gives excellent results with few complications at ten year evaluation. We believe that careful attention to bony and soft tissue balancing and equalization of gaps in flexion and in extension will prove beneficial for TKA longevity in even longer-term evaluation. Figures 1 and 2 demonstrate gap balancing blocks and alignment rods in extension and in flexion

Total knee arthroplasty (TKA) is one of the most successful surgeries to relieve pain and dysfunction caused by severe arthritis of the knee. Despite developments in prophylactic methods, deep venous thrombosis (DVT) and pulmonary embolism (PE) continue to be a serious complication following TKA. Otherwise DVT/PE is known to be a relatively low incidence in Asian patients, its accurate incidence is still controversial. Therefore, we prospectively investigated the incidence of DVT/PE after primary TKA by contrast enhanced computed tomography (CE-CT) and venous ultrasonography (US) in Japanese Patients. Methods. We prospectively investigated 51 patients who underwent primary TKA at the hospital from July 2013 to December 2013. All were of Japanese ethnicity. The mean age at the surgery was 74.9 years and average BMI was 26.0. There were 45 (88.2%) cases of osteoarthritis and 5 (9.8%) of rheumatoid arthritis. A single knee surgery team performed all operations with cemented type prostheses by utilizing pneumatic tourniquet. There were 21 cases of one-staged bilateral TKA and 30 of unilateral TKA. All patients were applied intermittent pneumatic compression (IPC) until 24 hours and graduated compression stockings for 3[高木1] weeks after the operation. Beginning from the day after the surgery, the patients were allowed walking with walker, along with the gradual range of motion exercise for physical thromboprophylaxis. Low-dose unfractionated heparin (LDUH) as a chemical thromboprophylaxis was administered subcutaneously for 3 days after the surgery. Informed consent was obtained regarding this thromboprophylaxis protocol. CE-CT and venous US were performed at the 4th day after surgery and images were read by a single senior radiologist team. The patients without DVT/PE by examination, they did not take additional chemical thromboprophylaxis. In cases of existence of DVT, continuous heparin administration and oral warfarin were applied and adjusted in appropriate dose for treatment. Warfarin was continued to be applied for at least three months until the patients had no symptoms and normal D-dimer level. In cases of PE, additional ultrasonic echocardiography (UCG) was performed, and then we consulted cardiologist to treat for PE. Results. CE-CT was performed in 42 patients (82.3%), otherwise nine patients (17.7%) could not take the examination because of exclusion criteria. There was no side-effect regard to contrast medium. The incidence of DVT and/or PE was 32 patients (62.7%), including two PE (3.9%), 21 DVT (41.1%) and nine both PE and DVT (17.6%). Six-teen patients were used LDUH routinely for 3 days after surgery. Five patients were used continuous heparin administration and oral warfarin instead of using LDUH because of medical co-morbidities. Additional continuous heparin administration and oral warfarin after LDUH use was needed in 26 patients. Three patients who had duodenal ulcer with chronic pancreatitis, massive PE with right heart strain and multiple DVT/PE with HIT antibody were needed another treatment. Conclusion. We prospectively investigated 51 patients for DVT/PE after primary TKA using CE-CT and venous US. The incidence of DVT/PE after primary TKA was 62.7%, including 21.5% of PE, as high frequency in Japanese patients

Introduction. The management of degenerative arthritis of the knee in the younger, active patient presents a challenge to the orthopaedic surgeon. Surgical treatment options include: high tibial osteotomy (HTO), unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). The aim of this study was to examine the long-term survival of closing wedge HTO in a large series of patients up to 19 years after surgery. Methods. Four hundred and fifty-five consecutive patients underwent lateral closing wedge HTO for medial compartment osteoarthritis (MCOA) between 1990 and 2001. Between 2008-2009, patients were contacted via telephone. Assessment included: incidence of further surgery, current body mass index (BMI), Oxford Knee Score, and British Orthopaedic Association (BOA) Patient Satisfaction Scale. Failure was defined as the need for revision HTO or conversion to UKA or TKA. Survival analysis was completed using the Kaplan-Meier method. Results. High tibial osteotomy survival was determined on 413 patients (91%) and, of the 397 patients who were alive at the time of final review, 394 (99%) were contacted for follow-up via telephone interview. The probability of survival for HTO at 5, 10 and 15 years was: 95%, 79% and 56% respectively. Multivariate regression analysis showed that age < 50 years (p=0.001), BMI < 25 kg/m. 2. (p=0.006) and ACL deficiency (p=0.03) were associated with better odds of survival. Mean Oxford Knee Score was 40/48 (range 17-48). Overall, 85% of patients were enthusiastic or satisfied and 84% would undergo HTO again at mean 12 years follow-up. Conclusion. High tibial osteotomy can be effective for periods longer than 15 years. However, results do deteriorate over time. Age < 50 years, normal BMI and ACL deficiency were independent factors associated with improved long-term survival of HTO

Background:. Blood loss, pain and wound healing contribute significantly to the perioperative morbidity after total knee arthroplasty. Prospective randomized controlled studies are lacking, to our knowledge. The purpose of this study was to determine whether platelet rich plasma (PRP) might prevent blood loss and postoperative pain and expedite wound healing following TKA. Methods:. Forty consecutive age, sex and BMI-matched patients who had unilateral or bilateral arthritis of the knee with similar deformity and preoperative range of motion were enrolled for this prospective randomized controlled double blinded clinical trial. Preoperative haemoglobin, range of motion, WOMAC and KSS scores were noted. Platelet-rich plasma was applied over the wound including the capsule, medial and lateral recesses in seventeen patients. Twentythree served as controls. Postoperative haemoglobin, blood loss, blood transfusion, VAS score, Wound score, KSS and WOMAC score were recorded and evaluated. Results:. Autologous platelet gel (APG) group had a smaller decrease in haemoglobin (Preop Hb–POD3 Hb) compared to control (1.97/3.56; p = 0.00). Postoperative blood loss was 173.2 ml vs 220.4 ml (p = 0.02). Blood transfusion was significantly less in the APG group (0.59 units/1.43 units; p = 0.001). APG group experienced less pain immediately, at 6 weeks and 12 weeks postoperatively (VAS 6.5/7.39, 2.67/3.84, 1.61/2.31; p = 0.00, 0.00, 0.00) and required fewer narcotics than control (15.24/22.65; p = 0.00). There was statistically significant difference in ROM at 5. th. day, 6 weeks and 3 months (79.44°/74.22°, 96.11°/87°, 97.6°/93.9° respectively; p = 0.00, 0.00, 0.01). There was no significant difference in the wound scores of two groups (30.96/34.23; p = 0.311). Significant difference was observed in KSS and WOMAC scores at 6 weeks (158.96/148.77, 17.3/23; p = 0.00, 0.00) and 12 weeks (166.96/161.42, 10.86/14.61; p = 0.00, 0.00). However no significant difference was found at 6 months. Conclusions:. We found significant reduction in blood loss, postoperative pain and need for narcotics after the use of autologous platelet gel in patients of total knee arthroplasty. Quicker and better functional outcome was observed in the APG group. However, at six months and later follow up, both groups had similar functional scores. Its role on wound healing was statistically insignificant. Level of Evidence: Therapeutic Level II

Introduction. Post traumatic arthritis of the knee can be a conseguence of distal femur fracture and retained hardware can complicate any further surgical option including arthroplasty. Both staged surgical procedures to remove before the hardware or simultaneous procedure of arthroplasty and removal of hardware have been indicated with an increased risk of complications. Aim of this study is to present a consecutive series of TKA following distal femur fracture using a computer assisted technique without the removal of retained hardware assessing both the efficacy of navigation in managing these complex cases as “routinary” primary arthroplasties. Material and Methods. A consecutive series of 16 patients treated with a computer assisted TKR following femoral fracture and with retained hardware were included in the study (group A). The interval between the fracture and operation averaged 5.8 years (range 1–12 years), the retained hardwares was an intramedullary nail in 6 cases, distal lateral plates in 7 cases and screws in 4 cases. All patients in group A were matched with a patient who had undergone to a computer assisted TKR using the same implant and software because of atraumatic knee arthritis in the same period (group B). Patients were matched in terms of age, gender, pre-operative range of motion, pre-operative arthritis severity according to Albaack classification, type and grade of deformity and implant features (cruciate retaining or sacrificing). There were 10 male and 6 female for each group, the mean pre-operative age was 64.3 years (range: 54–72) for the group A and 65.4 years (range: 53–74) for the group B. The mean pre-operative flexion was 85.5 degrees (range: 65–115) and 88.1 degrees (range: 70–115) for the post traumatic group and the matched group respectively. Results. There were no statistical significant differences in surgical time, hospital staying, intra/post operative complications. Likewise at a mean follow-up of 47 months no statistically significant difference was seen for the Knee Society, Functional, GIUM and WOMAC scores between the 2 groups. Implant alignment was similar between the 2 groups with similar radiological parameters. Conclusions. The results of this study demonstrated that knee arthritis following distal femoral fracture can be safely managed using computer assisted TKA without any need of hardware removal and obvious costs savings. The Authors achieved both same results and same complication rate of similar uncomplicated primary TKR

Introduction:. High tibial osteotomy (HTO) is a common treatment for medial compartment arthritis of the knee in younger, more active patients. The HTO shifts load away from the degenerative medial compartment and into the lateral compartment. This change can be accomplished with either a lateral closing or a medial opening wedge HTO. An HTO also potentially affects leg length. Mathematical models predict that the osteotomy type (opening versus closing) and the magnitude of the correction determine the change in leg length, but no in vivo studies have been published. The purpose of this study is to quantify and compare leg length change following opening and closing wedge HTO. Study Design:. Retrospective cohort study – Level III evidence. Methods:. Thirty-two medial opening and 32 lateral closing HTO's were selected from patients treated at our institution between 2006 and 2009. Pre-operative and one-year post-operative full-length lower extremity radiographs were obtained along with operative reports. Pre- and post-operative coronal plane alignment and leg length were measured and surgical details were collected. Results:. The 64 osteotomies were performed in 62 patients (43 male, 19 female) at an average age of 57 years. The mean opening wedge was 9.3 mm (range: 5 to 17 mm) and the mean closing wedge was 8.0 mm (range: 6 to 10 mm). Knee alignment changed from a mean of 174 degrees pre-operatively to a mean of 183 degrees post-operatively in both groups. In the medial opening wedge group, total leg length was found to increase from 836.3 ± 63.5 mm pre-operatively to 841.8 ± 64.1 post-operatively, a change of 5.5 ± 4.4 mm (p < 0.0001). A significant correlation was found between the amount of correction and the increase in overall leg length (r. 2. = 0.21, p = 0.009). In the lateral closing wedge group, total leg length was found to decrease from 840.6 ± 51.5 mm pre-operatively to 837.9 ± 52.0 post-operatively, a decrease of 2.7 ± 4.0 mm (p = 0.0008). No correlation was found between the amount of correction and the change in overall leg length. The difference in mean leg length change between opening and closing wedge osteotomies was 8.2 ± 5.9 mm (p < 0.0001). Conclusions:. Medial opening wedge HTO can result in significant leg lengthening depending on the degree of opening. Leg length changes associated with lateral closing wedge HTO are generally smaller. Both techniques results in less leg length change than mathematical models predict. Pre-operative leg length discrepancy should be considered when choosing an osteotomy technique

Background:. Full thickness cartilage defect of the knee frequently resulted in fibrous tissue formation, and larger lesions often lead to degenerative arthritis of the knee. Many techniques are designed to repair the cartilage defect including chondrocyte transplantation, microfracture and osteochondral graft. Each method has achieved some success but no universal results. Autologus osteochondral graft has gained in clinical popularity because of its technical feasibility and cost effectiveness. Purpose:. The purpose of this retrospective study was to evaluate the medium-term results of autologous osteochondral graft for focal contained articular cartilage defects of the knee in 25 patients with 26 knees with 2- to 7-year follow-up. Patients and Methods:. The cohort consisted of 17 men and 8 women with an average age of 31.3 ± 11.8 (range 20 to 65) years. One patient had bilateral knees. The diagnosis included 9 osteonecrosis, 10 osteochondritis dessicans, and 7 traumatic defects. A 1.0 mm oversized 10 mm long ossteochondral plug was harvested from either from the sulcus terminalis or the intercondylar notch, and implanted into the recipient site The numbers of osteochondral plug ranged from 1 to 3. In larger lesions, osteochondral grafts were implanted in the weight bearing area, and microfracture in non-weight bearing area. Postoperative management included crutch walking with non-weight bearing for 6 weeks, then partial weight bearing for another 6 weeks before full weight bearing. Range of knee motion, quadriceps and hamstring strengthening exercises were encouraged. The evaluations included functional assessment, radiograph of the knee and second look arthroscopy. Results:. At follow-up of 52.9 ± 20.3 (range 25 to 84) months, the results were 50% excellent, 35% good, 11% fair and 4% poor. Overall satisfactory results were noted in 85%. The improvements in pain and function of the knee ranged from 8 to 16 weeks after surgery. There was no correlation of the clinical results with the diagnosis of the lesion. However, the lesion size greater than 500 mm. 2. is associated with failure. Radiographic degenerative changes were noticed in 6 (23%) and 7 (27%) in medial compartment, 5 (19%) and 5 (19%) in lateral compartment, and 1 (4%) and 2 (8%) in the patellofemoral compartment pre- and postoperatively (P > 0.05). Twelve knees underwent a second look arthroscopy. Of the 11 asymptomatic knees, 8 knees with the defect smaller than 500 mm. 2. showed complete bonding of the graft to the adjacent host cartilage, and 3 cases showed minimal fissuring and fibrous tissue formation between graft and host tissue. One symptomatic knee with greater than 500 mm. 2. lesion showed extensive fibrous tissue between the graft and host cartilage. Conclusion:. Autologous osteochondral graft provides good or excellent results in 85% of patients with focal contained chondral and osteochondral defects of the knee. There was no correlation of the clinical results with the nature of the disease and the size of the lesion smaller than 500 mm. 2. Any lesion larger than 500 mm. 2. is prone to poor clinical outcome