兔膝关节持续被动活动对前交叉韧带重建术后切口局部组织血氧饱和度的影响

目的 探讨膝关节持续被动活动（continuous passive motion, CPM）对兔前交叉韧带重建术后切口局部组织血氧饱和度的影响. 方法 20 只八月龄雄性新西兰大白兔右侧后肢膝关节行自体双股半腱肌腱移植重建前交叉韧带手术,术后随机分为2组：自由活动组（n＝10）和CPM组（n＝10）.自由活动组笼内自由活动;CPM组应用兔膝关节持续被动活动器运动.术后第2天,近红外光技术装置ODISseyTM 局部组织血氧监护仪测量每一来回（屈曲30°～110°）不同CPM速度（分别为2.35°/s、3.2°/s 、8°/s）时的切口局部组织血氧饱和度（tissue oxygen saturation ,StO2）变化,选择最好的CPM范围和速度.分别在术前和术后第2、4、6、8、10、14天观察膝关节CPM不同角度时切口局部组织StO2的变化. 结果 与自由活动组相比,3种速度的CPM在不同屈曲角度下均保持较高的StO2,且有显著性差异（P＜0.05）,不同CPM速度之间StO2有显著性差异（P＜0.05）.每一来回（屈曲30°～110°）运动速度为3.2°/s时保持最高的StO2.在术前和术后第2、4、6、8、10、14天等各时间点,膝关节屈曲30°、60°、90°、110°时StO2均无显著性差异（P＞0.05）,不同的时间点（术前和术后第2、4、6、8、10、14天）切口的StO2差别均有显著统计学意义（P＜0.05）.术后第2～4天最低,然后逐渐上升.术后第2周拆线后,切口愈合良好,没有感染、血肿和切口裂开. 结论 兔膝前交叉韧带重建术后第2天开始进行膝关节CPM（屈曲30°～110°）,可增加切口局部组织血氧饱和度,以3.2°/s的CPM速度最佳.     

Effect of tibial drill-guide angle on the mechanical environment at bone tunnel aperture after anatomic single-bundle anterior cruciate ligament reconstruction

Purpose

The tibial drill-guide angle in anterior cruciate ligament (ACL) reconstruction influences the tunnel placement and graft-tunnel force, and is potentially associated with post-operative tunnel widening. This study aimed to examine the effect of the drill-guide angle on the stress redistribution at the tibial tunnel aperture after anatomic single-bundle ACL reconstruction.

Methods

A validated finite element model of human knee joint was used. The tibial tunnel with drill-guide angle ranging from 30° to 75° was investigated. The post-operative stress redistribution in tibia under the compressive, valgus, rotational and complex loadings was analysed.

Results

Compressive loading played a leading role on the stress redistribution at intra-articular tibial tunnel aperture. After ACL reconstruction, stress concentration occurred in the anterior and posterior regions of tunnel aperture while stress reduction occurred in the lateral and posteromedial regions under the compressive loading. Stress redistribution was partially alleviated by using the drill-guide angle ranging from 55° to 65°.

Conclusions

The present study quantified the effect of bone tunnel drill-guide angle on the post-operative stress redistribution. This phenomenon potentially contributed to tunnel widening. A tunnel drill-guide angle ranging from 55° to 65° was proposed based on the biomechanical rationale. It could serve as a helpful surgical guide for ACL reconstruction.     

A prospective study to assess the outcomes of revision anterior cruciate ligament reconstruction

Purpose

Continuously increasing numbers of primary anterior cruciate ligament (ACL) reconstructions invites a parallel increase in graft failures and need for revision ACL reconstruction surgery. High failure rates has previously stigmatised the revision surgery. We performed this study using multiple outcome measures together with clinical examination to offer a full assessment of the outcomes of this procedure.

Methods

Twenty patients, with mean age of 29.4 years (17–50 years), were included in this study prior to their revision ACL reconstruction surgery. All patients were followed prospectively collecting the Knee injury and Osteoarthritis Outcome (KOOS), International Knee Documentation Committee (IKDC) and Tegner-Lysholm scores pre- and post-operatively together with clinical assessment of the antero-posterior knee laxity.

Results

After a mean follow up interval of 30 months (16–60 months) significant post-operative improvement of IKDC, Tegner-Lysholm scores and knee antero-posterior laxity together with the Symptoms, Activities of Daily Living (ADL) and Quality of Life (QOL) components of the KOOS score was noticed (P < 0.05). However, there was no similar improvement in pain and sports components of the KOOS score (P > 0.05). There was no difference in the outcomes of different graft types.

Conclusion

Good outcomes of revision ACL reconstruction surgery are achievable. The use of different graft types did not affect the outcome of the procedure. Most of the patients opted to less aggressive sports participation after the revision procedure.     

Female athletes with ligament dominance exhibiting altered hip and ankle muscle co-contraction patterns compared to healthy individuals during single-leg landing

BackgroundAnterior cruciate ligament (ACL) injury is one of the most serious knee injuries and occurs frequently during exercise. Altered hip and ankle muscle co-contraction patterns may contribute to dynamic knee valgus and ACL injury mechanisms. Lack of dynamic control of ground reaction force (GRF) is known to be contributing factor for ACL injury by placing excessive force on passive structures. Muscle co-contraction is a dynamic mechanism for GRF absorption. Therefore, any alterations in co-contraction might be a risk factor for ACL injury. Ligament dominance is a term to define individuals who rely more on ACL ligament for GRF control.Research questionThis study aimed to compare the muscle co-contraction patterns of distal and proximal knee muscles during single leg landing in female athletes with and without ligament dominance.MethodsThis is a cross-sectional study. A total of 54 female athletes were assigned to the healthy (n = 27) and ligament dominance (n = 27) group based on their Tuck Jump test scores. The electromyography activity of the gluteus medius, adductor longus, tibialis anterior, peroneus longus, medial and lateral gastrocnemius was measured by an electromyography in drop down a 30-cm-high stair. A Multivariate Analysis of Variance (MANOVA) was used for statistical analysis (p ≤ 0.05).ResultsThe two groups demonstrated an overall significantly different muscle co-contraction patterns (P < 0.05). There was a decreased in co-contraction of proximal group and an increased co-contraction in the distal muscles in ligament dominant group.SignificanceThe findings have provided evidence to support the notion of neuromuscular imbalances in ligament dominance deficit. These findings can be useful for the coaches and experts to design preventive exercises and modify the current programs for the people affected by ligament dominance.     

腘绳肌腱结合双固定技术重建前交叉韧带

目的探讨采用腘绳肌腱股骨端胫骨端双固定技术重建前交叉韧带(ACL)的可行性及近期疗效。方法对25例ACL损伤行关节镜下ACL重建术,采用笔者自行设计双监视法解剖等长重建技术建立股骨胫骨隧道。移植物股骨端用Endobutton钢板和Rigidfix固定,胫骨端用Bio-Intrafix和Stample门形加压钉固定。结果本组获随访12～18(13.76±1.61)个月,未发现滑膜炎、韧带断裂、活动度明显障碍等并发症。根据Lysholm膝关节功能评分,术前评分:20～48(31.32±8.71)分;术后1年评分:90～98(94.96±2.56)分(t=37.69,P<0.01)。结论在腘绳肌腱重建ACL中应用股骨端胫骨端双固定技术具有手术操作简便,固定牢固,效果可靠的优点,值得推广。     

Arthroscopic fixation of chronic bicruciate tibial avulsion fractures: A case report

A cruciate ligament avulsion is a much less common form of injury than a cruciate ligament tear. Simultaneous tibial avulsion fractures of both cruciate ligaments occur even more rarely. Over the last decades, many studies have described arthroscopic fixation of acute cruciate tibial avulsion fractures, but arthroscopic treatment in a late presenting patient has not been reported in the literature. This case report presents a 32-year-old female with a chronic tibial avulsion fracture of both anterior cruciate ligament and posterior cruciate ligament. Simultaneous fixation of both fractures was performed arthroscopically at week four post-injury. At one year of follow-up, the patient had demonstrated full knee range of motion and stable knee with no complaints, and achieved excellent clinical outcomes. Radiographs showed union of both fractures, and the patient had resumed high-impact exercises.     

Common knee injuries,diagnosis and management

The knee is a frequently injured joint, and the incidence of injury is increasing. Young adults are most likely to injure their knee through sports participation, and this can result in long-term debility without appropriate early and deferred management. A detailed history and clinical examination, supplemented with radiographic evaluation of the joint and magnetic resonance imaging, assist in the diagnosis and can guide acute and definitive management. Early clinical assessment by an appropriately trained clinician is recommended. Fractures should be managed through orthopaedic trauma services, and soft tissue injuries are often best triaged into specialist acute knee clinics. Early management includes the use of plaster casts, splints or braces according to the injury pattern, and the principles or rest, ice, compression and elevation are followed. Early functional motion should be instituted when safe to do so to prevent arthrofibrosis and secondary complications. Fractures, including osteochondral lesions are typically best dealt with acutely, along with disruptions of the extensor mechanism and displaced meniscal tears causing locking. Non-acute surgical management of other soft tissue injuries is generally preferred, allowing the joint to recover before additional operative insult. Appropriate early intervention by specialist knee services is associated with improved long-term outcomes.     

Injection temperature significantly affects in vitro and in vivo performance of collagen‐platelet scaffolds

Collagen‐platelet composites have recently been successfully used as scaffolds to stimulate anterior cruciate ligament (ACL) wound healing in large animal models. These materials are typically kept on ice until use to prevent premature gelation; however, with surgical use, placement of a cold solution then requires up to an hour while the solution comes to body temperature (at which point gelation occurs). Bringing the solution to a higher temperature before injection would likely decrease this intra‐operative wait; however, the effects of this on composite performance are not known. The hypothesis tested here was that increasing the temperature of the gel at the time of injection would significantly decrease the time to gelation, but would not significantly alter the mechanical properties of the composite or its ability to support functional tissue repair. Primary outcome measures included the maximum elastic modulus (stiffness) of the composite in vitro and the in vivo yield load of an ACL transection treated with an injected collagen‐platelet composite. In vitro findings were that injection temperatures over 30°C resulted in a faster visco‐elastic transition; however, the warmed composites had a 50% decrease in their maximum elastic modulus. In vivo studies found that warming the gels prior to injection also resulted in a decrease in the yield load of the healing ACL at 14 weeks. These studies suggest that increasing injection temperature of collagen‐platelet composites results in a decrease in performance of the composite in vitro and in the strength of the healing ligament in vivo and this technique should be used only with great caution. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 964–971, 2009