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Purpose: Recurrent patellar dislocation is often associated with genu valgum. The purpose of this study was to analyze the shortterm results of single-incision, closing-wedge distal femoral osteotomy (CWDFO) combined with medial reefing and lateral release for recurrent patellar instability with genu valgum. Materials and Methods: Combined CWDFO/medial reefing/lateral release was performed on 10 knees. Clinical evaluation was based on pre- and postoperative Knee Society Score (KSS) and Kujala patellofemoral score. Radiographic evaluation was performed with reference to the weight-bearing line (WBL), the femorotibial angle (FTA), and the mechanical lateral distal femoral angles in the knee-standing view. Results: At a mean follow-up of 20±11.7 months (range, 12-42 months), KSS scores improved significantly, from 46.7±5.2 preoperatively to 87±4.4 postoperatively (p<0.001), as did the Kujala score, from 44±8 preoperatively to 86.6±6.8 postoperatively (p<0.001). The WBL decreased significantly, from 76±7% preoperatively to 41±11% postoperatively (p<0.001). The FTA was improved significantly, from 12.7±1.7° preoperatively to 4±4° postoperatively (p<0.001), as was the mLDFA, from 83±4° preoperatively to 91±1.3° postoperatively (p<0.001). Conclusion: Use of single-incision CWDFO combined with medial reefing and lateral release prevents patellar dislocation, corrects deformity, and improves clinical outcomes. [ABSTRACT FROM AUTHOR]

Purpose: The effect of sagittal plane angle of the tibial tunnel on the severity of tibial intra-articular aperture expansion caused by iatrogenic rereaming in anterior cruciate ligament (ACL) reconstruction using a modified transtibial technique is unknown. The purpose of this study was to compare the severity of intra-articular aperture widening at different angles (40°, 45°, and 50°) of the tibial guide (TG). Materials and Methods: Ninety-seven patients who underwent modified transtibial ACL reconstruction were randomly allocated to TG 40°, 45°, and 50° groups. Intra-articular tibial aperture width (TW) and tibial tunnel length (TTL) were measured intraoperatively using an arthroscopic ruler and a depth gauge. Results: The TG 50° group had significantly greater tibial aperture widening than the TG 40° group. There was a significant difference among TG 40°, 45°, and 50° groups and the percentage of knees with TTL <35 mm was 8%, 9% and 3%, respectively. There were 2 females with TTL <35 mm in TG 40° and 45° groups each. The average mediolateral length of the tibial plateau was 75 mm. Conclusions: This study shows that the TG angle of 40° would reduce the severity of intra-articular aperture widening of the tibial tunnel compared to 45° or 50° in modified transtibial ACL reconstruction. [ABSTRACT FROM AUTHOR]

We investigated the effect of combined fibular osteotomy on the pressure of the tibiotalar and talofibular joints in medial opening-wedge supramalleolar osteotomy. Three different tibial osteotomy gaps (6, 8, and 10 mm) were created in 10 cadaveric models, and the pressure in the tibiotalar and talofibular joints was measured under axial load before and after fibular osteotomy. The heel alignment angle and talar translation ratio were evaluated radiographically. An increase in osteotomy gap led to increases in hindfoot valgus (p = .001) and the contact and peak pressures in the talofibular joint (p = .03 and p = .004). In contrast, the contact and peak pressures in the tibiotalar joint were unchanged with an increasing osteotomy gap (p = .52 and p = .76). Fibular osteotomy reduced the contact and peak pressures in the talofibular joint (p < .001 and p = .001, respectively), and it did not influence the contact and peak pressures in the tibiotalar joint (p = .46 and p = .14, respectively). Therefore, fibular osteotomy might be necessary in supramalleolar osteotomy for medial ankle arthritis to minimize the increase in pressure in the talofibular joint, especially when the osteotomy gap is large. [ABSTRACT FROM AUTHOR]

Purpose: This study was to determine the efficacy of iliac crest reconstruction using bone cement in reducing pain and morbidity at the donor site in patients undergoing open wedge high tibial osteotomy (OWHTO) with tricortical iliac crest autologous graft. Materials and Methods: Thirty-three patients who underwent iliac crest reconstruction using polymethyl methacrylate (PMMA) bone cement (group A) and thirty patients who had no iliac crest reconstruction (group B) were enrolled in this study. All patients were evaluated for pain and functional disability related to graft harvesting using the pain and functional visual analogue scale (VAS) score during hospital stay and at 6 weeks, 3 months, and 6 months postoperatively. Results: There was significant difference between the two groups in terms of pain and function. The pain VAS score was significantly lower in group A than group B during the first 2 weeks postoperatively (p=0.04) and the functional VAS score was also significantly lower in group A during the first 2 weeks postoperatively (p<0.001) in terms of breathing, sitting up from the supine position, and standing up with crutches from the sitting position. Conclusions: Iliac crest donor site reconstruction using PMMA bone cement in patients undergoing OWHTO significantly decreased pain and improved function during the first 2 weeks postoperatively when compared to patients who underwent OWHTO without iliac crest reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: This study compared in vivo kinematic differences between Caucasian and South Korean patients after a posterior-substituting total knee arthroplasty (PS-TKA). Materials and Methods: In vivo motions of 9 Caucasian and 13 South Korean knees with a PS-TKA during weight bearing single leg lunge were determined using a dual fluoroscopic imaging technique. Normalized tibiofemoral condylar motions and articular contact locations were analyzed. Results: Femoral condylar motions of the two groups showed a similar trend in anteroposterior translation, but the South Korean patients were more anteriorly positioned than the Caucasian patients at low flexion and maximal flexion angles in both medial and lateral compartments (p<0.05). Mediolateral femoral condyle translations were similar between the two groups. For tibiofemoral articular contact kinematics, the South Korean patients had significantly more anterior contact locations at the medial compartment at low flexion angles, and more lateral contact locations at the lateral compartment at 0° and 90° flexion compared to the Caucasian patients (p<0.05). The South Korean patients had significantly larger distances between the medial and lateral contact locations at 60° and 90° flexion compared to the Caucasian patients (p<0.05). Conclusions: The study revealed that while the Caucasian and South Korean knees had similar femoral condylar motions, after PS-TKA the South Korean patients showed different articular contact point kinematics compared to the Caucasian patients. [ABSTRACT FROM AUTHOR]

Purpose: Bone grafting in opening wedge high tibial osteotomy (OWHTO) is still controversial. The purpose of this study is to compare the radiological outcomes of OWHTO with bone graft (autogenous, allogenous, and synthetic bone graft) and those without bone graft. Materials and Methods: PubMed, MEDLINE, EMBASE and Cochrane Register of Studies databases were searched using specific inclusion and exclusion criteria for radiological studies involving OWHTO with bone graft and without bone graft groups. All reported delayed union, nonunion and correction loss were analyzed. Data were searched from the time period of January 2000 through July 2014. In addition, a modified Coleman methodology score (CMS) system was used to assess the methodological quality of the included studies. Results: Twenty-five studies with a mean CMS value of 77 (range, 61 to 85 score) were included. In total, 1,841 patients underwent OWHTO using 4 different procedures for bone graft: autobone graft (n=352), allobone graft (n=547), synthetic bone graft (n=541) and no bone graft (n=401). There was a similar tendency for delayed union, nonunion and correction loss rate among the osteotomy space filling methods. Conclusions: The meta-analysis showed there was a similar tendency for radiological union and correction maintenance among patients undergoing OWHTO regardless of the type of bone in all of the studies. However, the currently available evidence is not sufficient to strongly support the superiority of OWHTO with bone graft to OWHTO without bone graft. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the biomechanical properties of a new anatomical locking metal block plate by comparing the initial biomechanical stability of three different fixation constructs for open wedge high tibial osteotomy (HTO). Materials and Methods: Sawbones composite tibiae were used to make a 10-mm opening osteotomy model with uniplane technique. The osteotomy was secured with three different types of plates: Group I, new osteotomy plate without a metal block (n=5); Group II, new osteotomy plate with a 10-mm metal block (n=5); and Group III, two short metal block plates (n=5). Single load to failure test and staircase load-controlled cyclical failure test were performed. In the single load to failure test, the yield load, maximum failure load, and the displacement of the osteotomy gap were measured. In the staircase cyclical load to failure test, the total number of cycles to failure was recorded. Failure modes were observed during both single and cyclic load tests. Results: Group II showed the highest yield and ultimate loads (1829±319 N, 3493±1250 N) compared to Group I (1512±157 N, 2422±769 N) and Group III (1369±378 N, 2157±210 N, p<0.05). The displacement of the opening gap in Group II (0.34±0.35 mm) was significantly lesser than the other groups (p<0.05). In the staircase cyclical load to failure test, the total number of cycles to failure was 12,860 at 950 N in Group III, 20,280 at 1,140 N in Group I, and 42,816 at 1,330 N in Group II (p<0.05). All the specimens showed complete fracture of the intact lateral sawbones area and slight displacement of the distal fragment of the specimens in the single load to test. None of the specimens showed deformed or broken screws and plates during the single load to test. During the fatigue test with staircase cyclic loading, no fracture of the lateral sawbones area was observed. Conclusions: This study demonstrated that the new anatomical locking metal block plate could provide sufficient primary stability for open wedge HTO. The addition of a metal block to this new plate can increase the stability of the osteotomy compared to the one without a metal block. [ABSTRACT FROM AUTHOR]

Multiple total knee arthroplasty (TKA) failure resulting from a recurrent infection is a challenging problem. Knee arthrodesis is one treatment option that normally involves the application of an external fixator, plate fixation, and intramedullary nailing. However, these approaches are not always successful, and a reinfection is a risk, particularly in older, medically compromised patients. This paper reports a new arthrodesis technique that uses a bundle of flexible intramedullary rods and an antibiotic-loaded cement spacer. This technique was used in two cases of multiple TKA failure that resulted from a recurrent infection. The procedure was successful in both cases with no evidence of rod or cement failure. Two advantages of this procedure are infection eradication and mechanical strength. However, this procedure should only be used for medically compromised elderly patients at high risk of rerevision TKA failure resulting from persistent periprosthetic infection because rod fracture or loosening can occur with time. [ABSTRACT FROM AUTHOR]

The authors investigated whether a remote postconditioning (remote post-con) procedure attenuated skeletalmuscle ischemia/reperfusion (I/R) injury. We determined the optimal protocol of remote post-con and investigated its mechanism. Ischemia was induced for 3 hours in rat left hindlimb and three protocols of remote post-con were applied in right hindlimb just before the end of ischemia. The first (10-second group) involved two cycles of 10 seconds of occlusion followed by 10 seconds of reperfusion. The second (5-minute group) involved two cycles of 5minutes of occlusion/reperfusion. The third (10-minute group) involved two cycles of 10minutes of occlusion/reperfusion. In 5- and 10-minute groups, wet/dry ratio and muscle fiber edema were significantly lower than control group. Muscle contractility was preserved in 5- and 10-minute groups. An injection of 5-hydroxydecanoate (a specific blocker of mitochondrial ATP-sensitive K+ [mKATP] channels) impaired this effect. This study demonstrates that remote post-con preserves muscle contractility and reduces tissue edema and necrosis, possibly through the activation ofmKATP channels. We suggest that two cycles of 5 minutes of occlusion followed by 5 minutes of reperfusion are optimal protocols of remote post-con in skeletal muscle I/R injury. [ABSTRACT FROM AUTHOR]

Osteochondroma is the most common benign tumor of the growing bone commonly involving the knee joint region. It often involves the metaphysis of the long bone, occurring extra-articularly. In spite of this, solitary intra-articular osteochondroma has rarely been reported in the literature. A 41-year-old man presented with diffuse pain and discomfort of the left knee for over 2 months. Clinical examination revealed a bony prominence involving the supero-lateral aspect of the left distal femur. Diagnostic evaluation involved radiography, magnetic resonance imaging, and a diagnostic arthroscopy, which showed features of an intra-articular osteochondroma in the left distal femur. Arthroscopic excision of the solitary intra-articular osteochondroma resulted in a complete relief of symptoms and return to full competitive activities. No recurrence of symptoms occurred during the one year of follow-up. Solitary intra-articular osteochondroma of the knee is an unusual case, which can be successfully managed with arthroscopy. [ABSTRACT FROM AUTHOR]

Background: Although stress radiography is frequently used to assess abnormal knee instability, the reliability and reproducibility for an evaluation of anterior-posterior instability of the knee may be affected by a variety of factors.Hypothesis: Different measurement methods result in different levels of reliability and reproducibility for instability; there may be a novel method that is more reliable and relatively unaffected by slight changes in flexion and rotation.Study Design: Cohort study (diagnosis); Level of evidence, 2.Methods: Stress radiographs of 40 patients with anterior cruciate ligament injury or reconstruction and 40 patients with posterior cruciate ligament injury or reconstruction were taken using the Telos device. The values of 4 conventional methods (medial-medial, lateral-lateral, middle-middle, and peripheral-central) and 1 newly devised method (Blumensaat line–anterior tibia) were compared. Intraclass correlation coefficients were examined to assess intraobserver and interobserver reliability of the measurements. For an evaluation of the reproducibility of each method, stress radiographs were taken twice (before and after the examination at the outpatient clinic) on the same day, and the values from the first and second stress radiographs were compared.Results: In the anterior drawer test, as to measurement reliability, the ranges of intraclass correlation coefficients were 0.713 to 0.889 for medial-medial, 0.624 to 0.812 for lateral-lateral, 0.834 to 0.932 for middle-middle, 0.722 to 0.892 for peripheral-central, and 0.891 to 0.963 for Blumensaat line–anterior tibia. As to test-retest reproducibility, the mean differences (SD) of displacement between the first and second radiograph were 1.0 (0.8) mm for medial-medial, 2.4 (2.3) mm for lateral-lateral, 1.7 (1.6) mm for middle-middle, 1.2 (0.6) mm for peripheral-central, and 0.5 (0.7) mm for Blumensaat line–anterior tibia. In the posterior drawer test, as to measurement reliability, the ranges of intraclass correlation coefficients were 0.859 to 0.958 for medial-medial, 0.773 to 0.915 for lateral-lateral, 0.859 to 0.951 for middle-middle, 0.852 to 0.958 for peripheral-central, and 0.893 to 0.961 for Blumensaat line–anterior tibia. Asto test-retest reproducibility, the mean differences (SD) of displacement between the first and second radiographs were 1.6 (1.3)mm for medial-medial, 1.8 (1.7) mm for lateral-lateral, 1.7 (1.5) mm for middle-middle, 1.4 (1.1) mm for peripheral-central, and 1.1 (1.2) mm for Blumensaat line–anterior tibia.Conclusion: Different methods of measuring stress radiographs resulted in different levels of reliability and reproducibility. In the anterior drawer test, the Blumensaat line–anterior tibia method showed the best measurement reliability and test-retest reproducibility. In the posterior drawer test, the Blumensaat line–anterior tibia method showed favorable measurement reliability and reproducibility, but the superiority could not be demonstrated. [ABSTRACT FROM AUTHOR]

Patients desire less pain and faster recovery of range of knee motion after total knee arthroplasty (TKA). While minimal invasive surgery (MIS) TKA appears to meet these needs, concerns exist regarding component malpositioning. Navigation systems can reduce the incidence of component misalignment. The present prospective randomized study compared limited medial parapatellar (LMPP) and mini-midvastus (MMV) approaches in 30 patients who had bilateral simultaneous primary TKAs. Each patient underwent LMPP on one knee and MMV on the other. Both approaches were navigation-assisted. We primarily analyzed postoperative pain (using visual analog scores), range of knee motion, and hospital for special surgery (HSS) scores in the first 6 postoperative months (i.e., the early postoperative period), and secondarily analyzed perioperative parameters and radiographic outcomes. The LMPP and MMV approaches were found to be similar in terms of pain measured at postoperative 3 days, 1, 2 weeks, 1, 3, and 6 months ( P = NS). Similarly, the 2 approaches were found to be similar in terms of range of motion measured at 1, 2 weeks, 1, 3, and 6 months ( P = NS), and in terms of HSS scores measured at 1, 3, and 6 months ( P = NS). There were also no differences between groups in terms of total blood loss, approach preferred by patients, and radiographic component positioning. The present study found that navigation-assisted MMV and navigation-assisted LMPP resulted in similar outcomes in terms of pain, ROM, HSS score, and radiologic outcomes over the first six postoperative months. We recommend the LMPP approach over the MMV approach in navigation-assisted MIS TKA because it is more familiar to surgeons and is easier to convert to the conventional approach where necessary. [ABSTRACT FROM AUTHOR]

Osteonecrosis of the knee is extremely rare following anterior cruciate ligament (ACL) reconstruction surgery. We report a case of osteonecrosis of the lateral femoral condyle in a patient after ACL reconstruction. The osteonecrotic lesion occurred in the same area as a large bone bruise, which was sustained at the time of the initial injury. We hypothesize that the combination of bone bruising and femoral tunnel drilling for ACL reconstruction may have compromised the overall vascularity of the articular cartilage and the subchondral bone, thereby resulting in osteonecrosis. [ABSTRACT FROM AUTHOR]

We present a new technique designed for the reduction and repair of bucket-handle meniscal tears. After assessing the rotation of the displaced tear fragment of the meniscus, the centrally displaced portion of the tear is vertically pierced with a suture hook enabling passage of a No. 0 PDS suture, both limbs of which are retrieved out of the joint. Next, using a spinal needle and a shuttle relay system, both ends of the No. 0 PDS on the femoral and tibial surfaces of the meniscus are extricated outside the joint capsule. In the final step, reduction of the displaced fragment is achieved by pulling on the PDS suture and the same suture is used for repair too, after which additional sutures are applied. This is a useful technique, which affords the benefit of rotational reduction of a bucket-handle meniscal tear using a single suture, as well as improved maneuverability for freshening of the tear margins prior to repair and additional suturing, and finally for repair as a full-thickness vertical suture. [ABSTRACT FROM AUTHOR]

The OrthoPilot TKA navigation system (B. Braun Aesculap, Tuttlingen, Germany) offers software to optimize soft tissue balance using gap balance techniques. However, there are no studies on the reliability of the navigation-guided gap technique. The goal of this study is to establish the reliability of the navigation-guided gap technique. The investigators measured flexion and extension gap in the medial and lateral sides of the knee joint after bone resection to evaluate the reliability of navigation-guided soft tissue balancing. Gap data from 100 cases of navigation-guided total knee arthroplasty were analyzed. We defined trapezoidal gap (unsatisfactory soft tissue balance) as a gap difference > 3 mm between the medial and lateral sides in extension and a 5-mm difference in 90° of flexion. Furthermore, gap difference between flexion and extension greater than 3 mm on the medial side and 5 mm on the lateral side was also considered a trapezoidal gap. Among 100 cases, 84 showed rectangular (acceptable) gap, and 16 showed trapezoidal gap. We also evaluated the correlation between clinical results including range of motion and soft tissue balance as well as characteristics of trapezoidal gap. This study suggests that the navigation-guided gap technique is a reliable method for optimizing soft tissue balance. [ABSTRACT FROM AUTHOR]

Background: Recently, double-bundle anterior cruciate ligament reconstruction has been advocated. However, there are little data on the in vivo biomechanics of the anteromedial and posterolateral bundles of the anterior cruciate ligament. Our objective was to measure the kinematics of the 2 bundles during weightbearing flexion. Study Design: Descriptive laboratory study. Hypothesis: The bundles of the anterior cruciate ligament are longest at low flexion angles during in vivo weightbearing flexion. Methods: Magnetic resonance images from 7 healthy subjects were used to create 3-dimensional models of the knee. The attachments of the anteromedial and posterolateral bundles were outlined on each model. Next, the subjects performed a quasi-static lunge from full extension to 135° while being imaged using a dual orthogonal fluoroscopic system. The models and fluoroscopic images were used to reproduce the motion of the knee. The length, elevation, deviation, and twist of the functional bundles were measured. Results: The anteromedial and posterolateral bundles were longest at low flexion angles and shortened significantly with increasing flexion. The elevation and deviation angles of both bundles were similar at low flexion angles (<45°). The twist of the bundles was minimal (<5°) at low flexion. Conclusion: With in vivo flexion, the anteromedial and posterolateral bundles did not demonstrate the reciprocal behavior noted in previous cadaveric studies. Both bundles were parallel and maximally elongated at low flexion angles. Our data suggest that if a double-bundle reconstruction is performed, 2 tunnels might need to be drilled in the femur and tibia to reproduce the orientation of the anterior cruciate ligament. Both anteromedial and posterolateral grafts should be fixed at low flexion angles to prevent over-constraint. [ABSTRACT FROM AUTHOR]

Bucket-handle tears less frequently occur in the lateral meniscus than in the medial meniscus. An 11-year-old male patient complained of painful swelling and locking due to a displaced bucket-handle tear of the lateral meniscus. We recommended an arthroscopic surgery; however, the patient left the hospital without surgical treatment. Six weeks afterwards, he returned without any complain of pain and he regained full range of motion. The final follow-up magnetic resonance imaging showed reduction of the torn meniscal fragment without any signal changes suggestive of a meniscal tear. We report a rare case of an isolated displaced bucket-handle tear of the lateral meniscus in an 11-year-old patient that healed spontaneously without surgical intervention. [ABSTRACT FROM AUTHOR]

This meta-analysis compared the gait patterns of unicompartmental knee arthroplasty (UKA) patients and total knee arthroplasty (TKA) patients during level walking by evaluating the kinetics, kinematics, and spatiotemporal parameters. Studies were included in the meta-analysis if they assessed the vertical ground reaction force (GRF), joint moment at stance, flexion at initial contact, flexion at swing, overall range of motion (ROM), coronal knee angle at stance, walking speed, cadence, and stride length in UKA patients or TKA patients. Seven non-randomized studies met the criteria for inclusion in this meta-analysis. UKA patients and TKA patients were similar in terms of vertical GRF (95% CI: -0.36 to 0.20; P = 0.60), joint moment (95% CI: -0.55 to 0.63; P = 0.90), kinematic outcomes (95% CI: -0.72 to 1.02; P = 0.74), walking speed (95% CI: -0.27 to 0.81; P = 0.32), and cadence (95% CI: -0.14 to 0.68; P = 0.20). In contrast, the stride length (95% CI: 0.01 to 0.80; P = 0.04) differed significantly between groups. Subgroup analyses revealed that the pooled data were similar between the groups: 1st maximum (heel strike), -0.18 BW (P = 0.53); 1st minimum (mid-stance), -0.43 BW (P = 0.08); and 2nd maximum (toe off), -0.03 BW (P = 0.87). On gait analysis, there were no significant differences in vertical GRF, joint moment at stance, overall kinematics, walking speed, or cadence between UKA patients and TKA patients during level walking. However, the TKA group had significantly shorter stride length than UKA patients. Although the comparison was inconclusive in determining which types of knee arthroplasty offered the closest approximation to normal gait, we consider it important to provide better rehabilitation programs to reduce the abnormal stride length in TKA patients compared to UKA patients.

Purpose: This prospective study aimed to evaluate radiographically, mechanical or hip-knee-ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to determine the incidence of inherent varus (mechanical limb alignment of N3° varus) and the factors influencing it. Methods: Three hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to assess the hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck-shaft angle to determine the incidence of inherent varus (mechanical limb alignment of N3° varus) and the factors influencing it. Results: Overall, the mean HKA angle was 177.6° ± 2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9° ± 1.8°). The incidence of inherent varus was significantly higher (p = 0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip-knee-ankle (HKA) angle showed significant positive correlation (r= 0.82, pb 0.001) with only the medial proximal tibial angle (MPTA). Conclusions: Inherent varus alignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures. [ABSTRACT FROM AUTHOR]