Tibiofemoral Joint Positioning for the Valgus Stress Test

Context:

Recommendations on the positioning of the tibiofemoral joint during a valgus stress test to optimize isolation of the medial collateral ligament (MCL) from other medial joint structures vary in the literature. If a specific amount of flexion could be identified as optimally isolating the MCL, teaching and using the technique would be more consistent in clinical application.

Objective:

To determine the angle of tibiofemoral joint flexion between 0° and 20° that causes a difference in the slope of the force-strain line when measuring the resistance to a valgus force applied to the joint.

Design:

Cross-sectional study.

Setting:

University research laboratory.

Patients or Other Participants:

Twelve healthy volunteers (6 men, 6 women: age  =  26.4 ± 5.6 years, height  =  170.9 ± 8.4 cm, mass  =  75.01 ± 14.6 kg).

Intervention(s):

Using an arthrometer, we applied a valgus force, over a range of 60 N, to the tibiofemoral joint in 0°, 5°, 10°, 15°, and 20° of flexion.

Main Outcome Measure(s):

Force-strain measurements were obtained for 5 positions of tibiofemoral joint flexion.

Results:

As knee flexion angle increased, slope values decreased (F_4,44  =  17.6, P < .001). The slope at full extension was not different from that at 5° of flexion, but it was different from the slopes at angles greater than 10° of flexion. Similarly, the slope at 5° of flexion was not different from that at 10° of flexion, but it was different from the slopes at 15° and 20° of flexion. Further, the slope at 10° of flexion was not different from that at 15° or 20° of flexion. Finally, the slope at 15° of flexion was not different from that at 20° of flexion.

Conclusions:

When performing the manual valgus stress test, the clinician should fully extend the tibiofemoral joint or flex it to 5° to assess all resisting medial tibiofemoral joint structures and again at 15° to 20° of joint flexion to further assess the MCL.     

Intra- and intermuscular variation in human quadriceps femoris architecture assessed in vivo

Despite the functional importance of the human quadriceps femoris in movements such as running, jumping, lifting and climbing, and the known effects of muscle architecture on muscle function, no research has fully described the complex architecture of this muscle group. We used ultrasound imaging techniques to measure muscle thickness, fascicle angle and fascicle length at multiple regions of the four quadriceps muscles in vivo in 31 recreationally active, but non-strength-trained adult men and women. Our analyses revealed a reasonable similarity in the superficial quadriceps muscles, which is suggestive of functional similarity (at least during the uni-joint knee extension task) given that they act via a common tendon. The deep vastus intermedius (VI) is architecturally dissimilar and therefore probably serves a different function(s). Architecture varies significantly along the length of the superficial muscles, which has implications for the accuracy of models that assume a constant intramuscular architecture. It might also have consequences for the efficiency of intra- and intermuscular force transmission. Our results provide some evidence that subjects with a given architecture of one superficial muscle, relative to the rest of the subject sample, also have a similar architecture in other superficial muscles. However, this is not necessarily true for vastus lateralis (VL), and was not the case for VI. Therefore, the relative architecture of one muscle cannot confidently be used to estimate the relative architecture of another. To confirm this, we calculated a value of whole quadriceps architecture by four different methods. Regardless of the method used, we found that the absolute or relative architecture of one muscle could not be used as an indicator of whole quadriceps architecture, although vastus medialis, possibly in concert with VL and the anterior portion of VI, could be used to provide a useful snapshot. Importantly, our estimates of whole quadriceps architecture show a gender difference in whole quadriceps muscle thickness, and that muscle thickness is positively correlated with fascicle angle whereas fascicle length is negatively, although weakly, correlated with fascicle angle. These results are supportive of the validity of estimates of whole quadriceps architecture. These data are interpreted with respect to their implications for neural control strategies, region-specific adaptations in muscle size in response to training, and gender-dependent differences in the response to exercise training.     

Microvascular cricoid cartilage reconstruction with the thoracodorsal artery scapular tip autogenous transplant

Conservation laryngeal surgery has been limited by difficulties with partial resection of the cricoid. Numerous options have been suggested that include temporoparietal flaps, free cartilage grafts, radial forearm free tissue transfers, and tracheal autotransplantation with vascular carriers. The authors present a one-stage procedure for the reconstruction of the cricoid cartilage based on the thoracodorsal artery scapular tip (Tdast) autogenous transplant that uses the curved tip of the scapula and does not create a secondary tracheal defect. Because the Tdast is a vascularized graft it may withstand radiation treatment.     

Bilateral cerebellopontine angle lipomas

Cerebellopontine angle (CPA) lipomas are extremely rare lesions and usually unilateral. We describe a case of a 36-year-old man with bilateral aural fullness that was discovered to have bilateral CPA lipomas associated with an abnormal hindbrain segmentation appearance. The patient was evaluated with 3.0T magnetic resonance imaging (MRI) system. MRI demonstrated the presence of bilateral CPA masses partially extending into the internal auditory canals. These lesions were hyperintense on both T1- and T2 weighted images. Facial and vestibulo-cochlear nerves together with tortuous vascular structures and fibro-connective septa were identified on T2-weighted 3D Fast Imaging Employing Steady-state Acquisition (FIESTA) sequences as areas of lower intensity coursing through the masses. Gadolinium administration yielded no enhancement. Conservative management was adopted.     

Malignant paroxysmal positional vertigo

Objective

An insidious percentage of paroxysmal positional vertigo appears to be intractable with canalith repositioning maneuver and also is not self-limiting. This type of positional vertigo is sustained by the action of intracranial tumors that mimics the clinical aspects of benign paroxysmal positional vertigo.Aim of this study is to clarify the features of these forms of positional vertigo, which we indicate as malignant paroxysmal positional vertigo.

Methods

We retrospectively reviewed the clinical records of all the patients who presented with vertigo spells and were managed at our tertiary care referral centre over a three years period. Two hundred and eleven patients with diagnosis of positional paroxysmal vertigo were included in the final study.

Results

Seven patients were affected by intracranial tumors causing a positional vertigo and were classified as malignant paroxysmal positional vertigo patients after radiological and histological diagnosis. These patients were affected by an internal auditory canal mass alone or with extension in the cerebello pontine angle that mimicked a benign positional vertigo.

Conclusion

We can conclude that the clinician should keep in mind the differentiation between benign positional vertigo and malignant positional vertigo. When the patients with positional vertigo presents a strange behaviour of symptoms, nystagmus or response to the canalith repositioning maneuver a radiological investigation must be undertaken in every doubtful case.     

儿童部分调节性内斜视的治疗研究

目的 探讨儿童部分调节性内斜视的手术时机、手术量及方法.方法 部分调节性内斜视儿童患者100例,均为戴镜治疗6个月或以上仍残留斜视角,且非调节部分斜视角大于10△的患者.将其分成2组,治疗组50例以平均斜视角计算矫正斜视手术量,对照组50例以戴镜后斜视角计算矫正斜视手术量.观察治疗效果.结果 治疗组双眼正位46例(92％),欠矫4例(8％).对照组双眼正位30例(60％),欠矫20例(40％).结论 儿童部分调节性内斜视应在戴全矫眼镜6个月以上再考虑手术,手术量应按照平均斜视角确定.     

银杏叶治疗原发性开角型青光眼的临床观察

目的:观察银杏叶治疗原发性开角型青光眼的临床疗效。方法:选择30(60只眼)名符合纳入标准的原发性开角型青光眼患者,比较使用银杏叶前后的视力、眼压和视野。结果:使用银杏叶前后,患者的视力差异没有显著性(P0.05);眼压及视野平均光敏感度(MS)和平均缺损(MD)的改变具有显著性(P0.05)。结论:银杏叶制剂对于治疗原发性开角型青光眼临床效果满意,值得推广。     

原发性闭角型青光眼单侧急性发作对侧眼激光虹膜周边切除术后随访研究

背景对于有房角关闭高危因素的眼,激光虹膜周边切除术（LPI）是首选的治疗方法,但可疑原发性房角关闭患者行LPI术后2年内仍有28％发生房角关闭,因此有必要了解影响LPI术后疗效的相关因素。目的观察原发性闭角型青光眼（PACG）急性发作眼的对侧眼行LPI后眼压及房角变化情况,分析与手术疗效相关的影响因素。方法回顾性分析单侧急性发作史的PACG患者（≥40岁）87例87眼,其对侧眼接受LPI,于术后1周,3、6、9、12个月随访眼压,并在裂隙灯下使用压陷式Goldmann单面房角镜观察LPI后颞、鼻、上、下各象限房角开放情况并按Shaffer房角分级标准记录,同时观察周边同位性房角关闭（AAC）范围以及周边房角黏连范围,与术前值进行比较。手术成功标准为：术后眼压在未使用药物情况下保持在6～21mmHg;并未出现青光眼特征性视神经病变及相应的视野缺损;无需任何抗青光眼药物或手术治疗。对影响LPI成功率的因素进行Cox多因素逐步回归分析。结果共完成随访并纳入分析79例79眼,其中男33例（41．8％）,女46例（58．2％）,年龄（61．4±0．4）岁。手术前后6个组眼压差异的总体比较差异有统计学意义（F=4．056,P〈0．01）,LPI术后各时间点的眼压均较术前降低,差异有统计学意义（P〈0．01）。房角除下方之外各象限及平均Shaffer级别有所增加,LPI术后1周、3个月和6个月与术前比较差异均有统计学意义（P〈0．05）;术后1周和3个月AAC范围较术前缩小,差异均有统计学意义（P〈0．05）,而术后6、9、12个月的AAC范围与术前比较差异无统计学意义（P〉0．05）。术后1年LPI成功者61例（77．2％）,术前眼压、房角各象限及平均Shaffer级别、AAC范围在LPI手术成功与失败病例之间差异有统计学意义（P〈0．01）。Cox逐步回归分析发现,AAC范围与LPI生存率之间具有相关性（Wald=48．150,RR=1．963,P〈0．01）,而术前眼压、房角各象限及平均Shaffer级别、年龄、性别与LPI生存率无明显相关性（P〉0．05）。结论PACG急性发作眼的对侧眼行LPI后可使房角增宽、眼压降低,术后成功率与术前AAC的范围有关,提示在考虑术前ACC范围条件下,LPI可以更有效地预防房角关闭的发生。     

Dilated episcleral veins with secondary open angle glaucoma

We report a case of dilated episcleral vein with secondary open angle glaucoma. A 65-year-old female presented with redness of both the eyes without any prior systemic history. Her ocular examination revealed dilated episcleral veins and a high intraocular pressure (IOP) of 38 mm Hg in the right eye. Systemic examination was negative for carotid cavernous fistula, low-grade dural arteriovenous fistula, dysthyroid ophthalmopathy, and primary pulmonary hypertension. During follow-up, her IOP remained in high thirties despite maximum medications. She underwent right eye trabeculectomy with partial thickness sclerectomy with sclerotomy. In the beginning, the sclerotomy incision was not deepened into the suprachoroidal space. She developed choroidal effusion during surgery and the sclerotomy was deepened into suprachoroidal space and straw color fluid was drained. Postoperatively, she developed choroidal effusion, which resolved with conservative management. This case highlights the importance of sclerotomy in such cases of high episcleral venous pressure.     

白内障手术对滤过术后的原发性闭角型青光眼前房深度和晶状体位置的影响

目的比较滤过术后晶状体混浊的原发性闭角型青光眼(PACG)与单纯老年性白内障患者超声乳化白内障吸出联合人工晶状体(IOL)植入术手术前后前房深度和晶状体位置的改变。设计比较性病例系列。研究对象小梁切除术后具有功能性滤过泡且未用药下眼压≤21 mm Hg的PACG患者16例(16眼)及年龄、性别匹配的单纯老年性白内障患者17例(17眼)。方法在超声乳化白内障吸出联合IOL植入术前及术后1周行眼前段相干光断层扫描(AS-OCT),比较PACG组和对照组手术前后的前房深度和晶状体位置参数。主要指标中央前房深度(ACD)、前房宽度(ACW)、晶状体厚度(LT)和晶状体矢高(CLR)。结果术前PACG组的ACD(1.74±0.33)mm较正常对照组(2.67±0.21)mm浅(t=-5.961,P=0.00),LT(5.38±0.44)mm和CLR(0.98±0.46)mm较正常对照组(分别为4.72±0.25 mm和0.51±0.17 mm)大(t=-3.707、3.028,P=0.00和0.04),两组间ACW比较无统计学差异(t=1.608,P=0.09);术后两组间的ACD(3.32±0.20 mm vs.3.65±0.40 mm)、ACW(11.12±0.42 mm vs.11.30±0.25 mm)和CLR(-0.60±0.14 mmvs.-0.56±0.29 mm)比较均无统计学差异(P均>0.05);手术后两组间ACD的平均增加值(1.58 mm vs.0.98 mm),CLR的平均减少值(1.58 mm vs.1.06 mm)有统计学差异(t=0.771、0.236,P=0.04、0.00)。结论滤过术后的PACG患者前房深度仍比正常人浅,晶状体较厚且位置靠前;行超声乳化吸出联合IOL植入术后可明显加深前房深度、改善前房拥挤的现象。