B. Bittersohl, C. Benedikter, A. Franz. T. Hesper, R. Krauspe, C. Zilkens, Department of Orthopedics, University of Düsseldorf, Medical Faculty, Düsseldorf, Germany C. Schleich, G. Antoch, Department of Diagnostic and Interventional Radiology, University of Düsseldorf, Medical Faculty, Düsseldorf, Germany H. S. Hosalkar, Hosalkar Institute, San Diego, CA, USA; Joint Preservation and Deformity Correction, Paradise Valley Hospital, San Diego, CA, USA; and Hip Preservation, Tricity Medical Center, San Diego, CA, USA One of the authors certifies that he (RK) has received or may receive payments or benefits, during the study period, an amount of less than USD 10,000 from Corin (Cirencester, UK).
Clin Orthop Relat Res. 2019 May;477(5):1007-1018. doi: 10.1097/CORR.0000000000000576.
Rowing exposes the femoral head and acetabulum to high levels of repetitive abutment motion and axial loading that may put elite athletes at an increased risk for developing early hip osteoarthritis.
QUESTIONS/PURPOSES: Do elite rowers demonstrate characteristic hip cartilage lesions on T2 MRI sequences compared with asymptomatic individuals who do not row?
This study included 20 asymptomatic rowers (mean age, 23 ± 3 years; nine females, 11 males) who had a minimum of 5 years of intensive (≥ 12 hours/week) training. The recruiting of the rowers took place from the central German federal rowing base, which has inherent intense training and selection requirements to declare these athletes as "elite rowers." We investigated one hip per study participant. MRI was performed on a 3-T scanner. The protocol included standard sequences, a double-echo steady-state sequence, and a multiecho data image combination sequence with inline T2 calculation (= the decay of transverse magnetization arising from molecular interactions [T2] and inhomogeneities in the magnetic field resulting from tissue susceptibility-induced field distortions and variations in the magnet itself), which detects changes in water content and the disruption of collagen structure. Although extrinsic and intrinsic influences on the T2 values including diurnal effects, MR technic-derived variations, and anatomic-related regional disparities need to be taken into account, low T2 values well below 20 ms indicate cartilage degeneration. Cartilage was morphologically analyzed in the anterior, anterosuperior, superoanterior, superior, superoposterior, posterosuperior, and posterior regions of the hip and graded as follows: Grade 0 = normal; Grade 1 = signal changes; Grade 2 = cartilage abrasion; Grade 3 = cartilage loss. Labrum was classified as follows: Grade 0 = normal; Grade 1 = partial tear; Grade 2 = full-thickness tear; Grade 3 = labrum degeneration. The T2 measurement was done through a region of interest analysis. For reliability assessment, morphologic evaluation and T2 measurement were performed by two observers while one observer repeated his analysis with a time interval > 2 weeks. Intra- and interobserver reliability was determined using κ analysis and intraclass correlation coefficients. Control T2 data were derived from a previous study on 15 hips in 15 asymptomatic volunteers of similar ages (seven males and eight females) who were not competitive rowers with similar MR hardware and imaging sequences.
Compared with the control group of asymptomatic volunteers who were not competitive rowers, we noted a high level of labrum and cartilage degeneration in the cohort of elite rowers. In the group of elite rowers, cartilage degeneration was noted in all hips. Regarding the acetabular cartilage, 271 zones could be evaluated. Of those, 44% (120 of 271) were graded normal, 6% (15 of 271) revealed signal alteration, 45% (122 of 271) demonstrated cartilage abrasion, and 5% (14 of 271) were noted to have full-thickness cartilage loss. Morphologic cartilage degeneration in the femoral head was less frequent. T2 values were lower than the control hips in all zones except for the posterior central acetabular zone (global T2 acetabular: 20 ± 6 ms, range, 9-36 ms, 95% confidence interval [CI], 19-21 ms versus 25 ± 5 ms, range, 14-44 ms, 95% CI, 24-25 ms, p < 0.001; global T2 femoral: 23 ± 7 ms, range, 9-38 ms, 95% CI, 22-24 ms versus 27 ± 5 ms, range, 17-45 ms, 95% CI, 26-28 ms, p < 0.001). The difference in T2 between the two study groups was superior in the peripheral zone of the anterosuperior region (16 ± 3 ms; range, 10-22 ms, 95% CI, 15-18 ms versus 26 ms ± 5 ms, range, 18-38 ms, 95% CI, 24-29 ms, p < 0.001).
We found signs of hip cartilage degeneration to a much greater degree in elite rowers than in asymptomatic controls. Although causation cannot be inferred, this is concerning, and future investigations including controlled longitudinal studies both on elite and nonelite athletes with sufficient cohort size are warranted to clarify our findings.
Level III, therapeutic study.
赛艇使股骨头和髋臼承受高水平的重复碰撞运动和轴向负荷，这可能使精英运动员面临早期髋关节骨关节炎的风险增加。
问题/目的：与不划船的无症状个体相比，精英赛艇运动员在 T2 MRI 序列上是否表现出特征性的髋关节软骨病变？
本研究纳入了 20 名无症状的赛艇运动员（平均年龄 23 ± 3 岁；女性 9 名，男性 11 名），他们至少有 5 年的强化（≥ 12 小时/周）训练。招募赛艇运动员是在德国联邦赛艇基地进行的，该基地有严格的训练和选拔要求，这些运动员被称为“精英赛艇运动员”。我们对每个研究参与者的每侧髋关节进行了调查。MRI 是在 3-T 扫描仪上进行的。该方案包括标准序列、双回波稳态序列和多回波数据图像组合序列，包括 inline T2 计算（即分子相互作用引起的横向磁化衰减[T2]和组织磁化率引起的磁场不均匀性导致的场扭曲以及磁体本身的变化引起的不均匀性），可检测水含量的变化和胶原结构的破坏。尽管需要考虑 T2 值的外在和内在影响，包括昼夜效应、MR 技术衍生的变化以及解剖相关的区域差异，但低于 20ms 的低 T2 值表明软骨退化。使用感兴趣区域分析对髋关节的前、前上、上上前、上、上后、后上和后区进行了形态学分析，并进行了以下分级：0 级=正常；1 级=信号改变；2 级=软骨磨损；3 级=软骨缺失。唇分为以下几类：0 级=正常；1 级=部分撕裂；2 级=全层撕裂；3 级=唇变性。T2 测量是通过感兴趣区域分析进行的。为了进行可靠性评估，形态学评估和 T2 测量由两位观察者进行，而一位观察者在 > 2 周的时间间隔内重复他的分析。使用κ 分析和组内相关系数确定了观察者内和观察者间的可靠性。对照组 T2 数据来自之前一项研究，该研究涉及 15 名年龄相似（7 名男性和 8 名女性）的无症状志愿者，他们不是竞技赛艇运动员，具有相似的 MR 硬件和成像序列。
与没有参加比赛的无症状志愿者对照组相比，我们在精英赛艇运动员组中观察到高等级的唇和软骨退变。在精英赛艇运动员组中，所有髋关节都出现了软骨退变。关于髋臼软骨，可评估 271 个区域。其中，44%（120/271）为正常分级，6%（15/271）显示信号改变，45%（122/271）为软骨磨损，5%（14/271）为全层软骨缺失。股骨头的形态学软骨退变较少见。除了后中央髋臼区（髋臼整体 T2 值：20 ± 6ms，范围 9-36ms，95%置信区间[CI]19-21ms 与 25 ± 5ms，范围 14-44ms，95%CI 24-25ms，p<0.001）外，所有区域的 T2 值均低于对照组，包括股骨头整体 T2 值：23 ± 7ms，范围 9-38ms，95%CI 22-24ms 与 27 ± 5ms，范围 17-45ms，95%CI 26-28ms，p<0.001）。两组之间的 T2 值差异在前上区的外周区更为明显（16 ± 3ms；范围 10-22ms，95%CI 15-18ms 与 26ms ± 5ms，范围 18-38ms，95%CI 24-29ms，p<0.001）。
与无症状对照组相比，我们在精英赛艇运动员中发现了更严重的髋关节软骨退变迹象。虽然不能推断因果关系，但这令人担忧，需要进一步进行包括精英和非精英运动员在内的对照性纵向研究，以明确我们的发现。
III 级，治疗性研究。
