The correlation between osteoarthritis stage and the effect of the lateral wedge insole for 3 months on medial meniscus extrusion in the knee joint

BackgroundMedial meniscus extrusion (MME) leads to symptomatic knee osteoarthritis (OA) due to increased mechanical stress. MME increases with weight-bearing, and the difference in MME between non-weight-bearing and weight-bearing status (ΔMME) is a factor that causes greater MME. The lateral wedge insole (LWI) is an ideal approach for decreasing the amount of ΔMME associated with the reduction of medial loading stress in the early stage of knee OA. However, the effect of the LWI for 3 months on the ΔMME and its response to OA stage have not been elucidated.ObjectiveTo investigate the effects of the LWI for 3 months on MME and the ΔMME in each stage of OA.MethodsParticipants were divided into three groups: no intervention with the LWI (control group; n = 9) and intervention with the LWI in early OA (early OA group: Kellgren–Lawrence (K/L) stage = 2, n = 17) and late OA (late OA group: K/L stage > 2, n = 13). MME was evaluated using ultrasound, and the ΔMME was obtained as the difference in MME from non-weight-bearing and weight-bearing conditions. These measurements were performed at two time points: the initial office visit as a baseline and post-3 months.ResultsThe weight-bearing MME and ΔMME values post-3 months were significantly decreased compared with those at baseline in the early OA group but not in the control or late OA groups.ConclusionsThe use of the LWI for 3 months decreased weight-bearing MME and ΔMME values, and its effectiveness was more pronounced in the early stage of knee OA.     

The relationship between a Segond fracture and meniscus injury in patients with anterior cruciate ligament tears

BackgroundSegond fracture may be identified when an anterior cruciate ligament (ACL) tear is diagnosed, and it has historically been considered a sign of significant knee trauma indicating intra-articular injury. There are few studies on the correlation between a Segond fracture and meniscus injury. The purpose of this study was to evaluate the relationship between a Segond fracture and meniscus injury in patients with ACL tears.MethodsA retrospective review of all patients undergoing acute ACL reconstruction (less than 1 month from the time of injury) between 2013 and 2020 was performed. The absence or presence of a Segond fracture was confirmed using preoperative radiographs. Demographic data (age, sex and body mass index), injury variables (time from injury and mechanism of injury) and arthroscopic features (meniscal or chondral injury) were analysed to investigate the relationship between a Segond fracture and meniscus injury.ResultsA total of 427 patients were included in the study. The incidence of Segond fractures was 12.4%. Among the patients with a Segond fracture, 15 patients were injured playing soccer (28.3%), 11 patients were injured playing basketball (20.8%), eight patients sustained the injury during racquet sports (15.1%), five patients (9.4%) were injured during less popular sports (such as skiing, ice-skating and boxing), and 14 patients (26.4%) were injured by contact mode of injury. A Segond fracture was a significant risk factor for lateral meniscus tears in patients with ACL tears (adjusted odds ratio, 1.938; 95% confidence interval, 1.078–3.481; P = 0.027).ConclusionThe incidence of Segond fractures in patients with acute ACL tears was higher than that reported in previous studies. A Segond fracture could increase the risk of a lateral meniscus tear in patients with an ACL tear.     

The role of meniscal tears and meniscectomy in the mechanical stability of the anterior cruciate ligament deficient knee

Background

The role of an intact meniscus in providing mechanical stability to the knee of anterior cruciate ligament (ACL) deficient and ACL reconstructed patients has not been well studied.

Medial meniscus extrusion as a predictor for a poor prognosis in patients with spontaneous osteonecrosis of the knee

BackgroundRisk factors for the progression of spontaneous osteonecrosis of the knee (SONK) remain unclear. The purpose of this study was to investigate the association between magnetic resonance imaging (MRI) findings of the meniscus and the prognosis of SONK.MethodsA total of 78 consecutive patients (female 85%; mean age 75.6 ± 7.2 years old) diagnosed with SONK were included. Of these, 30 patients did not receive surgery within 1 year from the onset of SONK (conservative group), while the remaining 48 patients underwent unicompartmental knee arthroplasty due to worsening of symptoms (UKA group). Using MRI findings obtained within 3 months of the onset, we compared the types of meniscus tear and medial meniscus extrusion between the conservative group and UKA group. We performed a receiver operating characteristics (ROC) analysis to estimate the cut-off value.ResultsPatients in the UKA group showed greater medial meniscus extrusion (absolute value, 4.2 mm ± 1.9 vs. 2.8 mm ± 1.2, P = 0.001; relative percentage of extrusion (RPE), 45.7% ± 21.5 vs. 30.7% ± 12.9, P = 0.001) and a higher prevalence of radial tear (P = 0.021) than those in the conservative group. In the multivariate analysis, RPE remained a relevant independent factor (P = 0.035) for future UKA. An ROC analysis found that the cut-off point of RPE was 33% (sensitivity, 81.2%; specificity, 63.3%).ConclusionRPE was a predictor of the prognosis of patients who underwent UKA within 1 year after the onset of SONK. Our results suggest that patients with RPE ≥ 33% are at high risk for progression.     

Clinical outcomes of medial meniscus posterior root repair: A midterm follow-up study

BackgroundTranstibial pullout repair of medial meniscus posterior root tears (MMPRTs) cannot prevent the progression of knee osteoarthritis. Conversions of knee arthroplasties are occasionally required following MMPRT repair. However, other knee-related surgical treatments following MMPRT repair are unclear. This study was aimed at investigating the midterm clinical outcomes and knee-related surgical events following MMPRT repair.MethodsPatients with MMPRT underwent pullout repair using FasT-Fix modified Mason-Allen (F-MMA) suturing with an all-inside meniscal repair device. Thirty-two patients with follow-up duration >2 years were enrolled. We assessed the clinical outcomes and postoperative surgical treatment of both knees.ResultsF-MMA pullout repair improved all clinical evaluation scores in patients with MMPRT at a mean follow-up of 36.1 months. Postoperative arthroscopic debridement was required for one patient. An additional MMPRT repair was performed in one patient on second-look arthroscopy. None of the patients required ipsilateral knee arthroplasty. In the contralateral knees, one pullout repair of a newly developed MMPRT and two knee arthroplasties were performed.ConclusionsThis study demonstrated that F-MMA pullout repair yielded satisfactory clinical outcomes. However, subsequent knee-related surgeries were observed in 6.3% of the pullout-repaired knees and 9.4% of the contralateral knees. Our results suggest that surgeons should be aware of the worsening and/or occurrence of contralateral knee joint disease, even when the postoperative clinical outcomes are satisfactory following MMPRT repair.Level of evidence: IV.     

Anatomical study of the communicating branches between the medial and lateral plantar nerves

The plantar areas of the foot have specific biomechanical characteristics and play a distinct role in balance and standing. For the forefoot surgeon, knowledge of the variations in the anatomy of communicating branches is important for plantar reconstruction, local injection therapy and an excision of interdigital neuroma. The anatomy of the communicating branches of the plantar nerves between the fourth and third common plantar digital nerves in the foot were studied in 50 adult men cadaveric feet. A communicating branch was present between the third and fourth intermetatarsal spaces nerves in all eight left feet and in six right feet (overall, 28%), and absent in 36 (72%). A communicating branch was found in 14 ft. Ten of the 14 communications were from the lateral to the medial plantar nerve. The length of the communicating branch ranged from 8 to 56 mm (average 16.4 mm) and its diameter was 0.2–0.6 times of the fourth common plantar digital nerve. The angle of the communicating branch with the common plantar digital nerve from which it originated was less than 30° in 11 ft, 30–59° in 27 ft, 60–80° in 8 ft, and more than 80° in 4 ft. Classification of the branch is based on the branching pattern of the communicating branch and explains variations in plantar sensory innervations. We think that the perpendicular coursing communicating branch is at higher risk to be severed during surgery.     

Gait pattern normalization after lateral retinaculum reconstruction for iatrogenic medial patellar instability

A case of medial patellar instability following Insall's proximal realignment studied pre- and postoperatively by gait analysis is presented. Preoperative gait analysis showed an increased stance time period as well as an increased horizontal braking, heel contact and toe-off vertical peak forces on the affected limb. In our case, gait parameters tended to shift towards a normal value pattern after reconstruction of the lateral retinaculum. We speculate about the importance of the passive restraining structures in patellar stability, in contrast to the role of the muscle function advocated by some authors.     

Arthroscopic repair of radial lateral meniscus [corrected] tear by double horizontal sutures with inside-outside technique

The purpose of this prospective study is to report the outcome of arthroscopic repair of radial lateral menicus tears at the junction of the anterior horn and body. Five patients with an average age of 27 years were treated. The repair was performed with double horizontal sutures by inside-out technique, using zone-specific, curved cannulae with no enhancement technique. A mean of 2.4 superior and 2.8 inferior stitches were performed. Reduction was obtained in all cases. Patients were evaluated using Lysholm functional knee scores. All patients were clinically and radiologically examined using MRI to assess meniscus integrity at the repair site, over an average follow-up period of 31 months. All patients were able to return to their former level of activity. In all cases, MRI showed a fully healed meniscus at the repair sites, with no further disruption of the debrided area. The mean Lysholm scores improved from 62 preoperatively to 94 postoperatively. The difference between preoperative and postoperative values was found to be statistically significant (p=0.029). No cases of postoperative extra or intra-articular complications were encountered. We found that repairing rather than resecting radial lateral menicus tears that extend into capsular zone, improves activity level.     

关节镜下膝内侧支持带紧缩外侧支持带松解治疗髌骨脱位

目的 　探讨关节镜下膝内侧支持带紧缩外侧支持带松解术在治疗髌骨脱位中的临床疗效。 方法 自2009 年3 月～2011年7月收治25 例25膝髌骨脱位,术前未接受过外科手术治疗。术中关节镜监视下松解外侧支持带并紧缩缝合内侧支持带。术后行正规康复训练。随访18～24个月,了解膝关节脱位复发情况及患膝功能恢复情况。 结果　术后无髌骨脱位复发,手术前后Lysholm 膝关节功能综合评分分别为（59.00±13.37）分和 （92.14±5.15）分（P＜0.05）;手术后影像测量对比髌骨适合角从术前（21.10±5.61）°纠正到（-1.70±7.41）°(P＜0.05);外侧髌股角从术前（-1.3±1.6）°纠正到（6.1±1.4）°(P＜0.05）,上述3项指标手术前后比较,均有统计学差异。 结论　关节镜辅助下膝内侧支持带紧缩配合外侧支持带松解术治疗髌骨脱位,手术创伤小,疗效满意。     

关节镜下内侧支持带重叠缝合联合外侧松解治疗青少年创伤性髌骨脱位的临床研究

目的 探讨膝关节镜下内侧支持带重叠缝合联合外侧支持带松解治疗伴有撕脱性骨折的创伤性髌骨脱位的临床疗效。方法 回顾性分析2018年5月至2021年5月秦皇岛市第一医院诊治的30例青少年初次创伤性髌骨脱位合并髌骨内侧缘撕脱性骨折的患者,均在关节镜下采用内侧支持带重叠缝合联合外侧支持带松解方法治疗。评估膝关节优良率,术后6个月及1年的Kujala髌股关节评分、Lysholm膝关节评分、IKDC膝关节评分的改善情况,记录术前、术后6个月、术后1年的膝关节活动度、髌骨倾斜角、髌骨适合角及髌骨外移率。结果 ①30例患者术后均恢复良好,髌骨位置解剖复位,术后平均随访时间为12.1个月（10 ～ 18个月）,均无复发性脱位或半脱位发生;②膝关节优良率、Kujala髌股关节评分、Lysholm评分、IKDC评分分别由术前的3.3%、（45.3±2.2）分、（36.8±2.5）分、（53.5±4.9）分提高至术后1年的93.3%、（92.9±2.2）分、（94.8±3.5）分、（98.3±5.0）分,差异均具有统计学意义（P＜0.05）;③膝关节活动度由术前的（25.3±4.5）°提高至术后1年的（125.4±3.2）°,髌骨倾斜角、髌骨适合角及髌骨外移率分别由术前的（12.5±1.8）°、（19.2±1.9）°、（18.5±2.3）%降至术后1年的（5.6±0.7）°、（6.8±1.0）°、（6.9±0.8）%,差异均具有统计学意义（P＜0.05）。结论 膝关节镜下内侧支持带重叠缝合联合外侧支持带松解治疗伴有撕脱性骨折的创伤性髌骨脱位安全有效,可获得稳定的髌骨运动轨迹,术后中短期随访影像学指标和临床功能评分满意。     

Multijoint dynamics and postural stability of the human arm

The goal of this study was to examine how the mechanical properties of the human arm are modulated during isometric force regulation tasks. Specifically, we examined whether the dynamic stability of the limb remained nearly invariant across a range of voluntarily generated endpoint forces and limb postures. Previous single joint studies have demonstrated that dynamic joint stability, as quantified via estimates of the joint damping ratio, is nearly invariant during isometric torque regulation tasks. However, the relevance of these findings to the control of multijoint posture has not been investigated previously. A similar degree of invariance at the multijoint level could suggest a fundamental property of the motor system that could be incorporated into the planning and execution of multijoint tasks. In this work, limb mechanics were quantified using estimates of dynamic endpoint stiffness, which characterizes the relationship between imposed displacements of limb posture and the forces opposing those displacements. Endpoint stiffness was estimated using a two-link robot operating in the horizontal plane at the height of each subjects glenohumeral joint. The robot was used to apply stochastic position perturbations to the arm and to measure the resulting forces. Endpoint stiffness dynamics were estimated nonparametrically and subsequently summarized using inertial, viscous and elastic parameters. We found that in the tasks studied, there was a differential modulation of endpoint elasticity and endpoint viscosity. Elasticity increased nearly linearly with increases in voluntary force generation while viscosity increased nonlinearly. This differential regulation resulted in limb dynamics that had a remarkably consistent damping ratio across all subjects and all tested conditions. These results emphasize the importance of considering the full dynamic response of a limb when investigating multijoint stability, and suggest that a minimal degree of limb stability is maintained over a wide range of force regulation tasks.This work was supported by the Department of Veteran Affairs Rehabilitation Research and Development Service, the National Institute of Health, and the Cleveland FES Institute     

The role of medial meniscus posterior root tear and proximal tibial morphology in the development of spontaneous osteonecrosis and osteoarthritis of the knee

Background

Medial meniscus posterior root tear (MMPRT) has been reported to play a key role in the development of spontaneous osteonecrosis of the knee (SONK) and osteoarthritis (OA) of the knee. However, little is known about the differences in the development of SONK and OA after MMPRT. The purpose of this study was to investigate the factors contributing to the development of these conditions.

The effect of a longitudinal tear of the medial meniscus on medial meniscal extrusion in anterior cruciate ligament injury patients

PurposeThe purpose of this study was to investigate the effect of a longitudinal tear of the medial meniscus (MM) and its meniscal repair on MM extrusion in anterior cruciate ligament (ACL)-injured patients. The hypothesis underlying this study was that a longitudinal tear of the MM is correlated with MM extrusion, and that the extrusion would persist after ACL reconstruction with concomitant MM repair.MethodsForty-three ACL-injured patients with a concomitant MM longitudinal tear were included in the MM tear group. Thirty-four solely ACL-injured patients without any meniscal injuries were included in the Control group. Medial meniscus extrusion width (MEW) was measured pre-operatively and three months after surgery on magnetic resonance imaging.ResultsPre-operative MEW in the MM tear group was significantly larger than that in the Control group (MM tear group: 1.5 mm, Control: 0.3 mm, P < 0.001). The MEW change in the MM tear group was significantly greater than that in the Control group three months after operation (MM tear group: 0.8 mm, Control: ? 0.2 mm, P < 0.001). The number of sutures required for repair was correlated with MEW both pre-operatively and postoperatively in the MM tear group (pre-operative: P = 0.005, R = 0.42, postoperative: P < 0.001, R = 0.54).ConclusionLongitudinal tear of the MM was correlated with MM extrusion and the MM extrusion persisted after ACL reconstruction with concomitant MM repair in the MM tear group. The initial meniscal tear size was directly correlated with the pre-operative MEW. Therefore, meniscal extrusion after longitudinal tears of the medial meniscus should be taken into careful consideration.     

外侧半月板损伤患者疼痛强度可影响跨越障碍动作模式

背景:疼痛是半月板损伤的重要体征并会影响患者的动作模式,研究疼痛对半月板损伤患者动作模式的影响有利于制定针对性的动作模式康复方案.目的:探寻疼痛强度对外侧半月板损伤患者跨越障碍时下肢动作模式的影响.方法:用8个惯性传感器与常速摄像机对80例外侧半月板损伤患者跨越障碍物时的下肢动作模式进行采集,以疼痛强度为自变量,分别对...     

Effect of masticating chewing gum on postural stability during upright standing

The purpose of this study was to investigate the effect of masticating chewing gum on postural stability during upright standing. To address this issue, 12 healthy subjects performed quiet standing on a force platform for the posturography study. The subjects were instructed to stand as stable as possible on the force platform in order to record the trajectory of the center-of-pressure (COP). After measuring the postural sway in the initial condition (pre-condition), the subjects were asked to stand while masticating chewing gum (gum-condition). Following the gum-condition, quiet standing without mastication was evaluated (post-condition) to ensure the effect of masticating chewing gum on postural stability. The trajectory and velocity of the COP were analyzed for each condition. We found that the postural stability tended to enhance during mastication of chewing gum. The rectangle area of the COP trajectory significantly diminished in the gum-condition and significantly enlarged in the post-condition. A similar effect was observed in the maximum velocity and standard deviation (SD) of the fore-aft amplitude of the COP trajectory. The values were significantly smaller in the gum-condition compared to those in the post-condition. These findings suggest that mastication of chewing gum affects the postural control by enhancing the postural stability during upright standing.     

Association of bone mineral density with postural stability and the fear of falling in Spanish postmenopausal women

Objective

The purpose of our study was to investigate the relationship between bone mineral density (BMD) and postural stability and the fear of falling in a 50- to 65-year-old postmenopausal population.

Study design

A cross-sectional, observational study was conducted on 118 postmenopausal women. According to their BMD values, participants were divided into two groups: BMD > −2.0 SD (n = 95) and ≤−2.0 SD (n = 23).

Main outcome measures

Postural stability, assessed with a resistive multi-sensor platform, fear of falling (FoF) and the history of falls in the last 12 months were investigated.

Results

Women with BMD ≤ −2.0 SD reported a significantly increased FoF when compared to women with BMD > −2.0 SD (P = 0.024, η² = 0.045, 1 − β = 0.624). In the postural stability analysis, the group with BMD ≤ − 2.0 SD showed, under the eyes-open condition, statistically significantly higher values for the velocity (VEO) (P = 0.040, η² = 0.037, 1 − β = 0.539) and the anteroposterior mean displacement of the center of pressure (YEO; P = 0.017, η² = 0.049, 1 − β = 0.669). No significant differences between groups were observed in the history of falls or in the rest of the stabilometric analyses.

Conclusions

In Spanish postmenopausal women under 65 years, a BMD ≤ −2.0 SD is significantly associated with postural instability (elevated VEO and XEO) and an increased FoF, which are two highly influential factors in the risk of falling.     

A comparison of the effect of preoperative gentling on the mouse killing and reactivity induced by lesions of the lateral septum,the medial accumbens nucleus,and the medial hypothalamus

Adult male rats were either gentled or not gentled 10 min each day for 5 days and then subjected to lesions of the lateral septum, the medial accumbens, the medial hypothalamus, or were given sham lesions. Mouse killing was tested in the living cage on Days 2, 7, and 14 postoperatively while reactivity to the experimenter was tested on Days 3, 8, and 15. The frequency of killing in the gentled groups was always significantly higher than that of the gentled sham-lesion controls, but the frequency of killing by the nongentled groups was seldom significantly higher than that of the nongentled sham-lesioned controls. Gentling caused a slight enchancement of killing in the lesioned animals and a slight attenuation of killing in the sham lesioned animals. Preoperative gentling attenuated reactivity to the experimenter in animals with lesions of the lateral septum but not in those with lesions of the medial accumbens nucleus or the medial hypothalamus. The observation that preoperative gentling tends to increase mouse killing confirms previous observations. The finding that preoperative gentling attenuates reactivity following septal but not medial accumbens or medial hypothalamic lesions suggests that these structures subserve different functions in the inhibitory modulation of defensive behavior.     

Characteristic location and rapid progression of medial femoral condylar chondral lesions accompanying medial meniscus posterior root tear

BackgroundThis study aimed to demonstrate the characteristics of the chondral lesion at the medial femoral condyle (MFC) in patients with medial meniscal posterior root tear (MMPRT), and to compare the progression rate of accompanying chondral disease in MMPRT with that in degenerative non-radial tear.MethodsThirty-one patients who underwent arthroscopic surgery for MMPRT and 31 controls who underwent arthroscopic surgery for degenerative medial meniscus posterior horn horizontal tear (MMPHT) were included. Accompanying chondral lesions in the MFC were evaluated by magnetic resonance imaging (MRI) at initial diagnosis and from video taken at arthroscopic surgery using the International Cartilage Repair Society (ICRS) classification system. The difference in severity and extent of the chondral lesion between initial diagnosis and surgery was measured.ResultsTwenty-five patients with MMPRT (80.6%) and 29 patients (93.5%) with MMPHT had ICRS grade ≥ 2 chondral injuries at MFC. In the MMPRT and MMPHT groups, the most severely injured areas of the MFC were the far medial compartment (52%) and central compartment (51%), respectively. Comparing MRI and arthroscopy, 12 patients (39%) in the MMPRT group showed progression of chondral disease after a mean of 3.5 months, whereas only three patients (10%) in the MMPHT group showed progression after a mean of 3.1 months.ConclusionsMFC lesions accompanying MMPRT were located more medially and progressed faster than those with non-root horizontal tear. Earlier intervention such as repair of MMPRT or high tibial osteotomy, if malalignment is present, may be considered in order to prevent the progression of chondral lesion.     

The substrates for lateral hypothalamic and medial pre-frontal cortex self-stimulation have different refractory periods and show poor spatial summation

Refractory periods of the substrates for lateral hypothalamic (LH) and medial pre-frontal cortex (MPFC) self-stimulation were behaviorally estimated. The beginning of recovery from refractoriness was estimated as the time at which recovery was 20% complete. In all 7 rats, this estimate differed substantially across sites, averaging 0.66 msec and 1.59 msec for the LH and MPFC substrates, respectively. The recovery of excitability approached asymptote later in the MPFC substrate (3.5 msec) than in the LH substrate (1.5 msec). These findings are consistent with the view that different fibers subserve the reinforcing consequences of LH and MPFC stimulation. This notion is strengthened by the observation that the rewarding effects of stimulation summated poorly when stimulating pulses were concurrently delivered to these two sites.