膝关节 Q 角变化规律的实验研究

本研究利用精密三维位移测读仪，研究分析了Ｑ角的变化趋势，以及对髌股关节运动的影响。研究结果表明，Ｑ角是一空间夹角，随屈膝角的增大而增大。力线在平面上的投影所呈的平面夹角Ｑｐ也就是通常所指的Ｑ角，在屈膝１５°左右达最大，而在９０°左右达最小。整个屈膝过程中，ＱＰ在５°－１５°之间变化，变化幅度达１０°左右。     

排球运动员髌骨软骨软化症与Q角关系的研究 Ⅱ.不同Q角对髌股关节生物力学的影响

本文对28名男子排球运动员的股四头肌进行等速肌力测试以提供髌股关节生物力学计算数据。根据膝关节等速测试力学模型和髌股关节作用力(PFJRF)三维力学模型、分析不同Q角对髌股剪切力(Fs),正压力(Fc)和合力(R)的影响。发现Q角增大对Fs影响最大,并使R方向明显偏外。而伸膝肌力大小或测试速度则对R和Fc产生明显影响。当Q角达18°时,Fs最大达2.1BW,R最大达6.6BW。如此之大的Fs及方向偏外的R,将导致压力分布严重不均和髌骨不稳、或许还造成膝关节运动过程中髌骨在股骨髁间沟内的旋转。因此,从生物力学上也证实Q角较大对排球运动员的髌股关节是不利的。     

排球运动员髌骨软骨软化症与Q角关系的研究——Ⅰ.临床流行病学研究

本文用临床流行病学方法调查了我国111名优秀男子排球运动员髌骨软骨软化症(CP)的患病情况及与Q角的关系,发现CP患病率达39.6%,占膝伤首位。111名男排队员的平均Q角为13°±3°,其中44例患者的Q角为14°±3°,较未患CP者的Q角12°±3°明显为大。CP患病率与Q角大小密切正相关,r=0.825。认为Q角在发育成熟的个体较恒定,建议作为运动员选材的指标之一。同时也探讨了Q角测量方法、认为体表定位Q角测量是一种简单易行,精确可靠的方法。选取髌骨中点是保证精确测量的关键。     

Dynamic medial patellofemoral ligament reconstruction in recurrent patellar instability: A surgical technique

The medial patellofemoral ligament (MPFL) is the primary stabilizer of the patellofemoral joint; its reconstruction has been recommended in adults over the past decade after recurrent patellar instability. However, there has been no standardized technique for reconstruction, therefore, ideal graft and technique for reconstruction are yet undetermined. However, dynamic MPFL reconstruction studies claim to be superior to other procedures as it is more anatomical. This preliminary study aims at assessing the outcomes of MPFL reconstruction in a dynamic pattern using hamstring graft. We performed this procedure in four consecutive patients with chronic patellar instability following trauma. MPFL reconstruction was done with hamstring tendons detached distally and secured to patellar periosteum after being passed through a bony tunnel in the patella without an implant and using the medial collateral ligament as a pulley. In all 4 knees, the MPFL reconstruction was isolated and was not associated with any other realignment procedures. No recurrent episodes of dislocation or subluxation were reported at 24 months followup.     

NO ASSOCIATION BETWEEN Q-ANGLE AND FOOT POSTURE WITH RUNNING-RELATED INJURIES: A 10 WEEK PROSPECTIVE FOLLOW-UP STUDY

Background/Purpose:

There is a paucity of knowledge on the association between different foot posture quantified by Foot Posture Index (FPI) and Quadriceps angle (Q-angle) with development of running-related injuries. Earlier studies investigating these associations did not include an objective measure of the amount of running performed.Therefore, the purpose of this study was to investigate if kilometers to running-related injury (RRI) differ among novice runners with different foot postures and Q-angles when running in a neutral running shoe.

Methods:

A 10 week study was conducted including healthy, novice runners. At baseline foot posture was evaluated using the foot posture index (FPI) and the Q-angle was measured. Based on the FPI and Q-angle, right and left feet / knees of the runners were categorized into exposure groups. All participants received a Global Positioning System watch to allow them to quantify running volume and were instructed to run a minimum of two times per week in a conventional, neutral running shoe. The outcome was RRI.

Results:

Fifty nine novice runners of mixed gender were included. Of these, 13 sustained a running-related injury. No significant difference in cumulative relative risk between persons with pronated feet and neutral feet was found after 125 km of running (Cumulative relative risk = 1.65 [0.65; 4.17], p = 0.29). Similarly, no difference was found between low and neutral Q-angle (Cumulative relative risk = 1.25 [0.49; 3.23], p = 0.63).

Conclusion:

Static foot posture as quantified by FPI and knee alignment as quantified by Q-angle do not seem to affect the risk of injury among novice runners taking up a running regimen wearing a conventional neutral running shoe. These results should be interpreted with caution due to a small sample size.

Level of Evidence:

2a     

Investigation of the Relationship Between Flatfoot and Patellar Subluxation in Adolescents

Patellar subluxation is common in adolescents, and a variety of factors are related to this condition, with valgus of the knee joint an important factor. The results of many studies suggest that flatfoot can cause an abnormality of the lower limb power line. Structural abnormalities of the foot caused by the high stresses exerted by body weight can lead to structural deformity of the knee and can also cause knee valgus. Screening for foot problems can help determine the risk of patellar subluxation, and early intervention can lessen the incidence of this condition. The purpose of the present study was to investigate the effects of flatfoot on the structure and function of the knees and, especially, the risk of patellar subluxation. A total of 72 participants were recruited for this cross-sectional study. The mean age at examination was 15.4 ± 4.0 (range 9 to 22) years. The measured parameters were heel valgus angle, arch index, and quadriceps angle (Q-angle). Overall, the mean values of the heel valgus angle, arch index, and Q-angle were 5.9° ± 2.4° (range 1° to 11°), 0.33 ± 0.07 (range 0.23 to 0.46), and 19.1° ± 3.5° (range 9° to 26°), respectively. The Q-angle was directly associated with the heel valgus angle (r = 0.818, p < .001) and arch index (r = 0.655, p < .001). We found that flatfoot can affect the morphology of the knee joint and increase the risk of patellar subluxation.     

Greater Q angle may not be a risk factor of patellofemoral pain syndrome

Background

A greater Q-angle has been suggested as a risk factor for Patellofemoral Pain Syndrome. Greater frontal plane knee moment and impulse have been found to play a functional role in the onset of Patellofemoral Pain Syndrome in a running population. Therefore, the purpose of this investigation was to determine the relationship between Q-angle and the magnitude of knee abduction moment and impulse during running.

Methods

Q-angle was statically measured, using a goniometer from three markers on the anterior superior iliac spine, the midpoint of the patella and the tibial tuberosity. Thirty-one recreational runners (21 males and 10 females) performed 8–10 trials running at 4 m/s (SD 0.2) on a 30 m-runway. Absolute and normalized knee moment and impulse were calculated and correlated with Q-angle.

Findings

Negative correlations between Q-angle and the magnitude of peak knee abduction moment (R² = 0.2444, R = − 0.4944, P = 0.005) and impulse (R² = 0.2563, R = − 0.5063, P = 0.004) were found. Additionally, negative correlations between Q-angle and the magnitude of weight normalized knee abduction moment (R² = 0.1842, R = − 0.4292, P = 0.016) and impulse (R² = 0.2304, R = − 0.4801, P = 0.006) were found.

Interpretation

The findings indicate that greater Q-angle, which is actually associated with decreased frontal plane knee abduction moment and impulse during running, may not be a risk factor of Patellofemoral Pain Syndrome.     

Q角对髌股关节接触力学的影响

本研究应用染色法和压敏片法,对8例新鲜尸体膝关节在不同Q角和屈膝角度时的髌股接触部位、面积和应力分布进行测试。结果表明:在生理Q角状态下,随着屈膝角度的增大,髌股接触从髌后关节面下极逐渐向上极移行,接触面积也逐渐增大,接触应力呈渐进缓慢增加:并在屈膝80°—90°时出现腱股接触现象,这种现象对保护关节软骨,避免局部软骨压力过高有重要意义。Q角改变后,接触区向内或向外侧偏移,接触面积无明显改变,但接触应力变化显著。作者认为异常的Q角是导致髌股疾病的一个潜在因素,无论是手术矫治还是运动员选材时都应予以重视。     

Q-angle undervalued? The relationship between Q-angle and medio-lateral position of the patella

Background. For an accurate quadriceps angle measurement, the patella must be centralised in the femoral trochlear groove, numerous authors have described lateral displacement of the patella in patellofemoral pain patients, this leads to the intriguing possibility that the Q-angle might be undervalued within patellofemoral pain patients who have laterally displaced patella.

Method. 109 asymptomatic subjects (51 male, 58 female) were assessed. Medio-lateral patella position was measured using a previous validated method and Q-angle was measured in standing with the quadriceps relaxed.

Findings. Mean Q-angle was 11.6° (SD 5.2) left knee, 11.3° (SD 4.9) right knee in the male subjects and 14.4° (SD 5.2) left knee, 13.3° (SD 5.5) right knee for female subjects. 40 females and 28 males had laterally displaced patellae. 13 subjects had centrally placed patellae (7 females, 6 males) with 28 subjects having medially displaced patellae (11 females, 17 males). Recalculation of Q-angle for the laterally displaced group brought about a statistically significant increase in angle. In the medial displaced group failed to produce a statistically significant decrease.

Interpretation. The adjusted Q-angle values for medially and neutral placed patellae brought the values very much into the centre of the reported ranges for Q-angles. After adjustment for lateral patella displacement, Q-angle values were towards the under end of values reported as normal, especially female values which were close to the previously reported pathological cut off point. Because of the inverse relationship between quadriceps strength and the magnitude of Q-angle and quadriceps crucial role in the aetiology of patellofemoral pain, any method which improves the reliability and applicability of Q-angle measurement could prove useful in investigations into the aetiology of and outcome from treatment of patellofemoral pain syndrome.