Restoration of Joint Inclination in Total Knee Arthroplasty Offers Little Improvement in Joint Kinematics in Neutrally Aligned Extremities.

Kinematically aligned total knee replacements have been shown to better restore physiological kinematics than mechanical alignment and also offer good postoperative satisfaction. The purpose of this study is to evaluate the extent to which an inclined joint line in a kinematically aligned knee can alter the postoperative kinematics. A multi-body dynamic simulation was used to identify kinematic changes in the joint. To accurately compare mechanical alignment, kinematic alignment and a natural knee, a "standard" patient with neutral alignment of the lower extremities was selected for modeling from a joint database. The arthroplasty models in this study were implanted with a single conventional cruciate-retaining prosthesis. Each model was subjected to a flexion movement and the anteroposterior translation of the femoral condyles was collected for kinematic analysis. The results showed that the mechanical alignment model underwent typical paradoxical anterior translation of the femoral condyles. Incorporating an inclined joint line in the model did not prevent the paradoxical anterior translation, but a 3° varus joint line in the kinematic alignment model could reduce the peak value of this motion by about 1 mm. Moreover, the inclined joint line did not restore the motion curve back to within the range of the kinematic curve of the natural knee. The results of this study suggest that an inclined joint line, as in the kinematic alignment model, can slightly suppress paradoxical anterior translation of the femoral condyles, but cannot restore kinematic motions similar to the physiological knee. This finding implies that prostheses intended to be used for kinematic alignment should be designed to optimize knee kinematics with the intention of restoring a physiological motion curve.

The Posterolateral Corner-Locked Technique Is Applicable in a Chinese Population Regarding the Tibial Component Rotation Alignment in Total Knee Arthroplasty.

Rotational malalignment between the femoral and tibial components in total knee arthroplasty (TKA) can affect clinical outcomes, but there is no consensus on how to best determine tibia tray orientation. The posterolateral corner-locked (PLCL) technique may be a new method. This study aims to assess the applicability of this technique in a Chinese population. Forty normal Chinese volunteers were recruited and underwent computed tomography (CT) of the lower limbs. Knee model reconstructions and simulated standard tibial osteotomy were conducted digitally. The transepicondylar axis (TEA), the Akagi line, and the line connecting the medial third of the tibial tubercle with the midpoint of the posterior cruciate ligament (PCL) were projected to the tibial cross-section and marked. The PLCL technique was applied using either symmetrical or asymmetrical tibial tray templates, and the anteroposterior (AP) axis of the tibial tray was marked. The angles between the TEA and these lines were calculated, and the statistical differences were analyzed. The angle between the TEA and the Akagi line and between the TEA and the line connecting the medial third of the tibial tubercle with the midpoint of the PCL were 96.90 ± 5.57 and 107.31 ± 5.95 degrees, respectively. The angles between the TEA and the AP axis of the symmetrical and the asymmetrical design tibial trays were 94.01 ± 4.21 and 96.65 ± 4.70 degrees, respectively. Except for the Akagi line and AP axis of the asymmetrical tibial tray, statistical differences were found between all lines (p < 0.05). The PLCL technique is principally suitable for Chinese patients requiring TKA when using the tibial component referred to in this study, although it may result in slight external rotation.

Rates of periprosthetic infection and surgical revision in Beijing (China) between 2014 and 2016: a retrospective multicenter cross-sectional study.

BACKGROUND: Periprosthetic joint infection (PJI) is a rare but devastating complication after total joint arthroplasty. There is a paucity of data on the incidence and prevalence of periprosthetic infection in mainland China. This study aimed to analyze the rates of surgical revision after arthroplasty due to PJI and the procedures followed in Beijing, China. METHODS: The study involved a retrospective multicenter cross-sectional survey of patients undergoing revisions for periprosthetic infection after hip/knee arthroplasty at nine hospitals in Beijing from 2014 to 2016. Age, gender, body mass index, primary diagnosis, comorbidity, primary surgery, treatment methods, and post-revision complications were analyzed. RESULTS: A total of 38,319 hip/knee arthroplasties and 366 (0.96%) revisions for PJI were identified. Of these, 161 (161/14,110; 1.14%) revisions involved hip arthroplasty, whereas 205 (205/24,209; 0.85%) revisions were due to knee arthroplasty. Procedures for revisions of infected hip included 7 (4.3%) cases of open debridement and prosthesis retention, 32 (19.9%) cases of one-stage exchange, 121 (75.2%) cases of two-stage exchange, and 1 (0.007%) case of hip dissection. As for the infected knee, the procedures included 45 (22.0%) cases of open debridement and prosthesis retention, 13 (6.3%) cases of one-stage exchange, 143 (69.8%) cases of two-stage exchange, and 4 (0.02%) cases of knee fusion. CONCLUSIONS: The study found the rates of revision due to PJI to be low. Nonetheless, the incidence of PJI in mainland China could be higher and calls for more elaborate studies in geographically and socioeconomically diverse health institutions.

Partial versus Intact Posterior Cruciate Ligament-retaining Total Knee Arthroplasty: A Comparative Study of Early Clinical Outcomes.

OBJECTIVE: Whether the entire posterior cruciate ligament (PCL) should be retained during cruciate-retaining total knee arthroplasty (CR TKA) is controversial. The goal of this study was to compare the early clinical outcomes of partial versus intact PCL-retaining TKA. METHODS: Ninety-two patients who had undergone unilateral CR TKA from March 2012 to June 2013 were enrolled in this study. Forty-six of these patients were randomly selected to undergo intact PCL-retaining TKA (intact group), whereas the remaining 46 patients underwent tibial osteotomy together with anterolateral bundle and bone island resection (partial group). All operations were performed by a senior orthopedic surgeon and the PCL was released to some extent in both groups. After TKA, active and passive flexion and extension exercises of the knee and lower limb strength exercises were maintained until at least 3 months after surgery. Before surgery and 6, 12, and 24 months after surgery, range of motion, Knee Society Clinical Rating System scores (including clinical and functional scores of the knee) and maximum anteroposterior (AP) displacement of the knee at 30° and 90° of knee flexion were evaluated in both groups. RESULTS: Fourteen patients were rejected from the final analysis because of loss to follow-up or development of complications. Thus, 40 patients from the partial group and 38 from the intact group were followed up for 24-41 months (mean 32.8 months). Knee functional scores were significantly higher in the intact than in the partial group (88.1 vs. 84.8 points) 24 months after surgery There were no significant differences in range of motion or knee clinical scores between the two groups at any time point. However, 12 and 24 months after surgery, the mean maximum AP displacement of the knee in 90° knee flexion was significantly greater in the partial than in the intact group (12 months: 6.3 vs. 5.7 mm; 24 months: 7.0 vs. 6.2 mm). CONCLUSION: Double-bundle PCL plays an important role in maintaining knee stability; the entire PCL should therefore be retained during CR TKA.

[Ligustrazine Promoted the Migration of Bone Marrow Mesenchymal Stem Cells by Up-regulating MMP-2 and MMP-9 Expressions].

OBJECTIVE: To explore the effect of ligustrazine on the migration of bone marrow mesenchymal stem cells (BMSCs) and protein expressions of matrix metalloproteinase-2 and-9 (MMP-2 and MMP-9) in vitro. METHODS: BMSCs were in vitro isolated and cultured using whole bone marrow adherent method, and phenotypes [surface positive antigens (CD29 and CD90) and negative antigens (CD34 and CD45)] identified using flow cytometry. BMSCs were divided into the blank control group, 25, 50, 100 µmol/L ligustrazine group, and the GM6001 group (100 µmol/L ligustrazine +MMPs inhibitor GM6001 ). The migration of BMSCs was tested by Transwell chamber test and wound healing assay after treated with ligustrazine for 24 h. The protein expressions of MMP-2 and MMP-9 were detected by Western blot. RESULTS: The third passage BMSCs grew well in uniform morphology. The expression rate of CD29, CD90, CD34, and CD45 was 96.9%, 97.3%, 0.2%, and 3.0%, respectively. Compared with the blank control group, the number of migrated cells and relative distance of cell invasion increased, and the protein expressions of MMP-2 and MMP-9 were elevated in each ligustrazine group (P < 0.05, P < 0.01). Compared with 100 µmol/L ligustrazine group, the number of migrated cells and relative distance of cell invasion decreased in 25 and 50 µmol/L ligustrazine groups and the GM6001 group (P < 0.01). Protein expression of MMP-2 decreased in 25 and 50 µmol/L ligustrazine groups (P < 0.01). CONCLUSION: Ligustrazine could promote the migration of BMSCs in vitro, and its mechanism might be related to up-regulating expression levels of MMP-2 and MMP-9 protein.

Open Patellar Tendon Tenotomy and Debridement Combined with Suture-bridging Double-row Technique for Severe Patellar Tendinopathy.

OBJECTIVE: To create a new surgical procedure for chronic severe patellar tendinopathy and to evaluate its clinical efficacy. METHODS: In this retrospective study, the data of 12 patients with severe patellar tendinopathy in 14 knees who had undergone surgical treatment at Beijing Chao-Yang Hospital between 1 March 2009 and 1 August 2013 were analyzed. Inclusion criteria included severe patellar tendinopathy (Phase III), conservative therapy for more than 6 months, American Society of Anesthesiology status Grade I-II, and body mass index <30. Patients with severe osteoporosis, complete tendon disruption (Phase IV) and those who were unable to cooperate were excluded. There were 8 men (10 knees) and 4 women (4 knees) cases. The patients' ages ranged from 38 to 54 years (mean, 45.3 years). All surgeries had been performed by the same physician. Surgical treatment comprised incising open patellar midline tenotomy, complete debridement and suture-bridging double-row fixation. Isotonic and kinetic chain exercises were implemented after the second post-operative week. A gradual increase to full weight-bearing was allowed after the third post-operative week and a gradual return to unrestricted use of the leg after the eighth post-operative week. Preoperative and postoperative visual analogue scale (VAS) scores and Lysholm knee scores were obtained from the medical records or at recent postoperative follow-up visits and the results compared using Student's two-tailed paired t-test. RESULTS: VAS scores decreased by a mean of 6.7 points (range, 1.1-7.8 points) during follow-up (minimum duration 14 months; range, 14-44 months) and Lysholm scores increased from 55.7 ± 6.5 points to 90.4 ± 6.2 points. Three cases (4 knees) achieved excellent outcomes (≥95 points) and 9 cases (10 knees) good outcomes (range, 86-94 points). No intraoperative or postoperative complications occurred. There were significant differences between preoperative and postoperative VAS and Lysholm scores (P < 0.01). CONCLUSIONS: All study patients achieved good or excellent outcomes. No patellar tendon rupture or suture fixation failure occurred during follow-up. Suture-bridging double-row fixation is a simple and reliable method that not only improves patients' clinical symptoms, but also restores knee joint function.

[Buyang Huanwu decoction promotes neuroblast migration from subventricular zone via inducing angiogenesis after ischemia].

OBJECTIVE: To study the effect of Buyang Huanwu decoction (BYHWD) inducing angiogenesis on the neuroblast migration from the subventricular zone and its mechanisms after focal cerebral ischemia. METHOD: The middle cerebral artery occlusion (MCAO) was performed to mice for 30 minutes to establish the model. The rats were divided into sham group, model group, BYHWD group and endostatin group. BYHWD (20 g x kg(-1), ig) and endostatin (10 µg, sc) were administered 24 h after ischemia once a day for consecutively 14 days. At 14 d after ischemia, the density of micro-vessel and the number of neuroblasts in the ischemia border zone were determined by immunofluorescence staining. The mRNA and protein expression of cell-derived factor-1 (SDF-1) and brain-derived neurotrophic (BDNF) were examined by real-time PCR and Western blot. RESULT: Compared with the model group, BYHWD significantly increased the density of micro-vessel and the number of DCX positive cells in the ischemia border zone (P < 0.01), and significantly increased the SDF-1 and BDNF mRNA and protein expression (P < 0.01). Compared with BYHWD group, endostatin significantly reduced the density of micro-vessel and the number of DCX positive cells in the ischemia border zone (P < 0.01), as well as the SDF-1, BDNF mRNA and protein expression (P < 0.01). CONCLUSION: BYHWD could promote the neuroblast migration from the subventricular zone via inducing angiogenesis after cerebral ischemia, the mechanism may be correlated with up-regulating the expression of SDF-1 and BDNF.

Gallic acid can play a chondroprotective role against AGE-induced osteoarthritis progression.

BACKGROUND: Advanced glycation end products (AGEs) are a group of stable covalent compounds generated by proteins, lipids, other macromolecules and sugar through a series of non-enzymatic reactions. As reported, AGEs can cause widespread pathophysiological responses through activation of AGE receptors (RAGEs) on the cell surface, and play an important role in the pathogenesis of osteoarthritis (OA). We hypothesized that the antioxidant and anti-glycan agent gallic acid (GA) can work against the effects of AGEs and can be used as a potential drug for the cure of OA. METHODS: The present study first explored the negative functions of AGEs via AGE-treated chondrocytes isolated form rabbits. Then, we observed the protective role of GA in AGE-treated chondrocytes by measuring the reactive oxygen species (ROS), superoxide dismutase (SOD), collagen II, aggrecan, nitric oxide synthase (iNOs) and cyclooxygenase-2 (COX-2) in vitro. Finally, the changes in a cartilage lesion in a rabbit model of knee osteoarthritis was observed. RESULTS: Exposure of chondrocytes to AGEs resulted in a reduction of ROS, SOD, collagen II and aggrecan, and an increase in iNOs and COX-2, which means exposure promoted OA lesions in a clinical setting. When AGE-treated chondrocytes were pretreated with GA, there were no significant changes in these key components compared to the normal chondrocytes. In vivo study showed cartilage degradation was reduced by GA as compared to the vehicle group. CONCLUSION: The results of this study confirmed the chondroprotective role of GA and provide a potential drug for the relief of OA.

Kinematic analysis of a posterior-stabilized knee prosthesis.

BACKGROUND: The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. METHODS: Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0-135° flexion. RESULTS: Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, "rollback" compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. CONCLUSIONS: There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis.

Is the posterior cruciate ligament necessary for medial pivot knee prostheses with regard to postoperative kinematics?

PURPOSE: Excellent clinical and kinematical performance is commonly reported after medial pivot knee arthroplasty. However, there is conflicting evidence as to whether the posterior cruciate ligament should be retained. This study simulated how the posterior cruciate ligament, post-cam mechanism and medial tibial insert morphology may affect postoperative kinematics. METHODS: After the computational intact knee model was validated according to the motion of a normal knee, four TKA models were built based on a medial pivot prosthesis; PS type, modified PS type, CR type with PCL retained and CR type with PCL sacrificed. Anteroposterior translation and axial rotation of femoral condyles on the tibia during 0°-135° knee flexion were analyzed. RESULTS: There was no significant difference in kinematics between the intact knee model and reported data for a normal knee. In all TKA models, normal motion was almost fully restored, except for the CR type with PCL sacrificed. Sacrificing the PCL produced paradoxical anterior femoral translation and tibial external rotation during full flexion. CONCLUSION: Either the posterior cruciate ligament or post-cam mechanism is necessary for medial pivot prostheses to regain normal kinematics after total knee arthroplasty. The morphology of medial tibial insert was also shown to produce a small but noticeable effect on knee kinematics. LEVEL OF EVIDENCE: V.

Central tendon splitting combined with SutureBridge double-row technique as a surgical treatment for insertional Achilles tendinopathy.

BACKGROUND: Surgical treatment of insertional Achilles tendinopathy should be considered when a variety of conservative measures fail. To achieve a satisfactory outcome, thorough debridement of the Achilles tendon is critical, besides excision of the bursitis and the calcaneal exostosis. Central tendon-splitting provides straightforward access to the calcified or degenerative tissue within the Achilles tendon. For Achilles tendon reconstruction if detachment is present, several surgical techniques have been reported. Controversy surrounds the technique can provide maximum security for reattachment of the Achilles tendon. The SutureBridge double-row construct, initially used in rotator cuff repair, is probably a good choice. METHODS: Ten consecutive patients with insertional Achilles tendinopathy underwent tendon reattachment using the SutureBridge technique through a central tendon-splitting approach. We retrospectively evaluated the surgical outcomes, which included pre- and postoperative visual analog scale (VAS), postoperative Maryland Foot Score (MFS), postoperative range of motion of the affected ankle, and related complications. Follow-up was performed in the outpatient department. RESULTS: One patient was lost to follow-up. Nine patients (two male and seven female; 12 feet) were reviewed with a minimum follow-up of six months (range 6-30 months). The postoperative VAS pain scores were markedly lower than the preoperative scores. Postoperative MFS was 92.1±8.0 (range 74-100). No intra- or postoperative complications were found, except for one case of delayed healing incision. At last follow-up, all affected ankles achieved their normal range of motion, and patients were able to resume daily activities without any assistive device. CONCLUSIONS: Although a randomized control trial with a larger sample may be necessary to compare the central tendon-splitting combined with the SutureBridge technique with other techniques, our results confirmed that it was a promising alternative for treatment of insertional Achilles tendinopathy.

The effects of implantation of tibio-femoral components in hyperextension on kinematics of TKA.

PURPOSE: Implantation of prosthetic tibio-femoral components in hyperextension is a well-established and effective procedure, but whether prosthetic orientation in the sagittal plane has any effects on the postoperative kinematics remains unclear. The purpose of this study is to explore how the aforementioned hyperextension affects knee kinematics. METHODS: Validated computational dynamic TKA models were established. Based on representative literatures and actual operation specifications, femoral and tibial components were assembled with 0° or 5° of hyperextension. Dynamic data, including the timing of cam-post engagement, anterioposterior femoral translation and tibial axial rotation coupling with knee flexion, were recorded for analysis. RESULTS: 5° of femoral component hyperextension delayed cam-post engagement by an angle of 2°. Nevertheless, a 5° posterior slope of the tibial component resulted in a 38° delay in engagement. Comparing this with the femoral component at the same angle of hyperextension, the tibial component could more evidently assist in the prevention of paradoxical femoral anterior translation and the promotion of tibial internal rotation through early flexion. CONCLUSION: Tibio-femoral components in hyperextension did significantly alter postoperative kinematics, especially for the tibial component. These results suggest that the degree of tibial posterior slope cutting should be more highly scrutinized intraoperatively. LEVEL OF EVIDENCE: II.

[Comparison and clinical significance between geometrical characteristics of tibial plateau between Uighur nationality and Han people].

OBJECTIVE: To compare the difference and clinical significance of geometrical characteristics of tibial plateau between Uighur nationality and Han people by computed tomography scan and three-dimensional reconstruction. METHODS: A total of 49 inpatients and outpatients were randomly selected (normal knee without any tibial involvement) and volunteers of Han people and 45 ones of the Uighur nationality at our hospital and cooperative hospitals. Then the subjects were divided into groups according to gender. The following linear geometric parameters of tibial plateau were measured: width of tibial plateau (WTP), width of medial tibial plateau (WMTP), sagittal length of medial tibial plateau (SLMTP), width of lateral tibial plateau (WLTP) and sagittal length of lateral tibial plateau (SLLTP). RESULTS: (1) Males were greater than females in linear parameters in the same group (P < 0.01); (2) the groups of Uighur nationality were greater than groups of Han people in linear parameters in the same gender (P < 0.05); (3) the gaps between WMTP and WLTP, SLMTP and SLLTP of Uighur nationality were all more approximate than those of Han people (P < 0.05). CONCLUSION: The geometrical characteristics of tibial plateau have some visible discrepancy between Uighur nationality and Chinese Han people. The prosthetic design concept and technology of total knee replacement targeting the Uighur nationality should take into consideration the discrepancy.

[Clinical outcome of surgical treatment of terrible triad of elbow].

OBJECTIVE: To evaluate the clinical outcome of surgical treatment of the posterior dislocation of the elbow with coroniod and radial head fractures. METHODS: From January 2004 to March 2009, 9 patients with terrible triad of the elbow were reviewed. There were 7 males and 2 females (4 left elbows and 5 right elbows), with an average age of 41.2 years, ranged from 21 to 67 years. The radial head fractures were classified according to the Schatzker-Tile criteria: 4 patients had the fractures of type I, 3 patients had type II and 2 patients had type III. The ulnar coronoid fractures were classified according to the Regan-Morrey criteria: 2 patients had the fractures of type I, 5 patients had type II and 2 patients had type III. The general approach was used to repair the damaged structures sequentially from deep to superficial, through coronoid, anterior capsule, radial head, and lateral ligament complex to common extensor origin. If there was valgus instability in the elbow after the operation, the medial collateral ligament should be repaired with nonabsorption sutures. The plaster was applied for 7 to 10 days with elbow flexion in 90 degrees and the forearm in full pronation. Unrestricted motions and rehabilitation began at the 8th week after operation. Recovery of regular occupation depended on the degree of physical activity required, and it typically took 3 months for heavy physical laborers to return to work. RESULTS: All the patients were followed up from 6 months to 5 years, with a mean duration of (31 +/- 6) months. At the 3rd month after operation, the mean rang of motion in flexion and extension of the elbow was (102 +/- 3) degrees (ranged from 80 degrees to 110 degrees), and the mean range of motion in pronation and supination of the forearm was (135 +/- 6) degrees (100 degrees to 150 degrees). According to the criteria of the Mayo scoreing system, the results were excellent in 5 cases, good in 3 cases, and fair in 1 case. Three patients had heterotopic ossification at the 6th month after operation. Among them, 2 patients had no effects on elbow function and were not treated, 1 patient had effects on flexion-extension of the elbow and was treated with resection of heterotopic ossification through lateral approach combined with early rehabilitation, the MEP score of the patient improved from fair to good. CONCLUSION: The key points for treating the terrible triad of the elbow are to restore the elbow normal anatomy and early rehabilitation to avoid the elbow stiff.