关节镜术诊断与治疗退行性股骨髁间窝前交叉韧带撞击症

目的:报道退行性股骨髁间窝前交叉韧带撞击症14膝.作者对关节镜在本病诊断中的优点、分型及治疗方法进行探讨.方法:所有病人均合并骨性关节炎,男5膝,女9膝;左侧8膝,右侧6膝.主要表现为膝关节前部或定位不确定的钝痛、渐进性关节伸屈障碍和反复关节积液.关节镜术野良好,可动态检查前交叉韧带在运动中所受阻碍的情况,提高本病诊断率并有助于分型,关节镜下可将本病分为三型:磨损型、挤夹型、混合型.治疗采用关节镜下股骨髁间窝扩大成形术加镜下关节清理术.结果:随访13例,平均18个月,术后关节功能均超过术前水平,尤其关节伸屈功能障碍改善明显,目前尚无复发需再次手术者.结论:关节镜术对本病的诊断与治疗益处颇多,关节镜下股骨髁间窝扩大成形术是治疗本病的良好方法.     

前交叉韧带残端引起伸膝受限的研究

目的:综合分析研究前交叉韧带损伤后残端引起伸膝受限的发生情况。方法:回顾性研究2008年6月至2010年4月536例入院治疗的前交叉韧带损伤患者,通过术中关节镜观察前交叉韧带残端增生卡压情况,同时观察患者伸膝受限情况及伴随的病史、体征、MRI及病理结果。结果:536例患者中有11例因前交叉韧带残端卡压引起伸膝受限。平均受限角度为9.1°(5°～15°),所有伴有伸膝受限的病变发现时间在伤后3周到6个月(平均6.8周)。术前MRI可以看到残端迂曲存在于髁间窝,术中观察断裂位置均位于上止点附近,残端形态为不规则团块,病理显示病变为排列紊乱的纤维增生结缔组织和韧带成分,未见软骨和骨样组织形成。结论:前交叉韧带损伤后残端卡压可引起伸膝受限,其形成与前交叉韧带断裂位置和损伤后残端翻转有关,发生率不高,应尽早治疗,术前MRI有助于诊断。     

骨性后踝撞击综合征的影像学特征分析

目的 探讨骨性后踝撞击综合征的影像学特征。方法 选取我院疑似骨性后踝撞击综合征患者97例,均行关节镜确诊后再行X线摄影和MRI检查。结果 疑似骨性后踝撞击综合征患者97例,经关节镜诊断确诊骨性后踝撞击综合征患者84例。经X线摄影诊断骨性后踝撞击综合征准确率为59.79%。经MRI诊断骨性后踝撞击综合征准确率为74.23%。MRI诊断骨性后踝撞击综合征准确率高于X线摄影,差异有统计学意义(P <0.05)。MRI诊断骨性后踝撞击综合征灵敏度高于X线摄影,差异有统计学意义(P <0.05); MRI与X线摄影诊断骨性后踝撞击综合征特异度比较差异无统计学意义(P> 0.05); MRI诊断Kappa值高于X线摄影。结论 MRI诊断骨性后踝撞击综合征准确率优于X线摄影,且诊断灵敏度高。     

半腱肌腱和股薄肌腱重建前交叉韧带后Cyclops综合症临床研究

目的:研究采用自体半腱肌腱和股薄肌腱重建前交叉韧带(ACL)后膝关节内Cyclops综合症的发生情况。方法:回顾性研究2004~2005年197例采用半腱肌腱和股薄肌腱重建ACL后取出内固定患者,平均年龄25.85岁。取内固定时通过病史、体征、X线及KT-2000评估膝关节功能,手术同时进行膝关节镜探查,观察关节内髁间窝增生物情况,并进行统计分析。结果:所有患者中发现有髁间窝结节样增生物(统称为Cyclops病变)形成28例,其中2例伴有伸膝受限(同健侧膝关节比较),Cyclops综合症的发生率为1.02%(2/197)。无Cyclops病变的患者中伸膝受限5例。根据是否存在Cyclops病变将所有患者分为Cyclops组和非Cyclops组,两组伸膝受限发生率的差异无统计学意义(2χ=0.268)。Cyclops病变的病理表现为增生变性的瘢痕样组织,无骨性成分。Cyclops组患者取钉时KT-2000检查结果显示134N下差值平均为1.8mm,有24例均恢复到原来的运动水平。结果表明,采用半腱肌腱和股薄肌腱重建前交叉韧带后Cyclops病变发生率较高,但产生伸膝受限(Cyclops综合症)的发生率低。     

膝关节前交叉韧带断裂后股骨外髁髁间侧壁关节软骨的关节镜下表现

目的:探讨股骨外髁髁间侧壁软骨作为骨软骨移植术和软骨细胞移植术的取材部位的可行性.方法:回顾研究了235例膝前交叉韧带断裂行关节镜下韧带重建时的软骨损伤情况,分析了前交叉韧带断裂患者股骨外髁髁间侧壁软骨有无退变及其与髁软骨损伤、年龄、病程的关系.结果:本组235例患膝中,伴Ⅲ度以上软骨损伤占20%(其中伴髁间增生10例).Ⅲ度以上局限性软骨损伤而髁间侧壁非负重区软骨外观正常占15.74%.髁间侧壁非负重区软骨外观正常的Ⅲ度以上软骨损伤患者平均年龄为25.8岁,平均病程为16.75月;髁间侧壁非负重区软骨外观异常的Ⅲ度以上软骨损伤患者平均年龄为42.6岁,平均病程122.5月,后者明显大于前者,有显著性差异(t检验,P<0.02).结果提示,前交叉韧带断裂合并软骨损伤需要进行骨软骨移植时,可同时考虑在外髁髁间侧壁取材进行修复;ACL损伤后急性期和亚慢性期,关节镜下未见股骨外髁髁间侧壁软骨明显异常.自体骨软骨移植或自体软骨细胞移植治疗软骨损伤时,病程越短,供区所提供的骨软骨质量就越好,病程较长、年龄较大患者多发生膝骨关节炎,往往累及髁间侧壁,骨赘形成、髁间窝变窄,此时软骨的质量差,不能作为供区.     

MRI对髂胫束综合征的诊断价值

目的:总结髂胫束综合征的MRI特征,指导临床诊断和治疗。方法:回顾性分析8例髂胫束综合征患者(9膝)的MRI资料。结果:9膝中,病程≥3个月者(3膝)与3个月者(6膝)髂胫束厚度分别为股骨外侧髁上方3.85~7.02 mm、2.57~4.29 mm,股骨外侧髁范围2.48~4.11 mm、1.11~2.63 mm,胫骨Gerdy结节2.61~3.81 mm、2.51~3.89 mm。髂胫束信号不均者(4膝)与信号正常者(5膝)髂胫束厚度分别为股骨外侧髁上方3.45~7.02 mm、2.57~4.23 mm,股骨外侧髁2.48~4.11 mm、1.11~2.48 mm,胫骨Gerdy结节2.61~3.81 mm、2.51~3.89 mm。9膝中髂胫束浅方脂肪结构信号异常4膝;髂胫束深方脂肪结构水肿6膝;滑膜侧隐窝局限性积液7膝;其他伴发异常有5膝合并关节积液、4膝合并半月板损伤、2膝合并交叉韧带损伤。结论:MRI在发现髂胫束和周围结构的形态及信号异常,协助临床诊断及鉴别诊断,评估髂胫束损伤部位、程度及范围,指导临床治疗方面具有一定价值。     

关节镜下经后侧入路重建后交叉韧带

目的 探讨关节镜下经后内侧、后外侧和后纵隔入路保留板股韧带和残留的后交叉韧带(PCL)纤维重建PCL的临床效果. 方法 对9例PCL损伤患者在关节镜下结合常规关节镜入路和后内侧、后外侧入路及后纵隔入路保留板股韧带和残留的PCL纤维,应用自体腘绳肌腱重建PCL.在后外侧入路的关节镜监视下,胫骨隧道定位在PCL胫骨止点外侧关节面下方1～1.5 cm.股骨隧道经前外侧入路定位于股骨内侧髁关节软骨后方1 cm.自体肌腱移植物利用钢丝引导通过骨隧道,移植物两端用可吸收界面螺钉固定.术后6个月了解膝关节功能恢复情况.结果 9例患者均获随访,时间7～14个月,平均8.6个月.术后6个月,患者均无伸膝受限;2例有10°～15°屈膝受限;1例有Ⅰ度后抽屉试验阳性.Lysholm膝关节功能评分术前(47.6±14.9)分,术后6个月(92.9±4.6)分(P＜0.01). 结论 膝关节后内外侧入路和后纵隔入路重建PCL的方法,镜下视野清楚、无盲区,操作安全,韧带的胫骨止点定位准确,短期疗效肯定.     

关节镜下应用LARS人工韧带同时重建前、后交叉韧带

目的 探讨关节镜下应用LARS人工韧带重建前交叉韧带(ACL)、后交叉韧带(PCL)同时损伤的方法及疗效. 方法 关节镜下同时重建13例ACL、PCL损伤的患者,重建材料采用LARS人工韧带.术后随访12～36个月,采用国际膝关节文件编制委员会(IKDC)韧带标准评价表和Lysholm膝关节功能评分表评估患膝功能,通过KT-1000检查膝关节前后松弛度.结果 术后无膝关节感染发生;均无伸膝受限,屈膝活动度105°～125°,平均117°.术后随访时IKDC评分:A类10例(77%),B类3例(23%).屈膝25°位KT-1000检查:双侧膝关节前向松弛度差异＜2 mm 12例,3～5 mm 1例;屈膝70°位检查:＜2 mm 12例,2～4 mm 1例.术前Lysholm膝关节功能评分为(63.8 ±2.9)分(49～69分),终末随访时为(91.1±2.7)分(88～95分),差异有统计学意义(P＜0.01). 结论 关节镜下同时重建膝关节ACL、PCL是目前治疗ACL、PCL同时损伤的一种微创、安全、有效的手术方法,近期疗效佳.     

膝关节三维CT重建评估住院医师嵴发生率

目的:探讨关节镜下前交叉韧带(ACL)重建术中使用住院医师嵴作为股骨端定位骨性标志的临床可行性。方法:对2011年~2015年间在我院行膝关节CT三维重建的患者中,选取80例,年龄4~81岁,男性53人,女性27人,依照年龄分为4组,A组(4~12岁)、B组(13~30岁)、C组(31~45岁)、D组(45~81岁),其中B组和C组为我科前交叉韧带断裂拟手术患者,各组20例。分析每组膝关节髁间窝外侧嵴(1ateral intercondylar ridge)即住院医师嵴(resident ridge)三维CT重建之发生率及镜下观察结果。结果:4组患者住院医师嵴发生率:A组0%,B组15%,C组15%,D组45%,组间比较差异有统计学意义(P<0.05),住院医师嵴的发生率与患者的性别无相关性(P>0.05),与年龄有相关性(P<0.05)。B组和C组全部患者在关节镜下采用股骨外侧髁内侧壁后1/3定位ACL股骨止点足印区的原则,行有限髁间窝清理后,结果显示,术前三维CT重建证实存在住院医师嵴的患者,术中却未被发现,但在2组患者均能发现位于股骨外髁内侧壁股骨止点足印区内有一条白色致密纤维切迹。住院医师嵴和白色致密纤维切迹无相关性(P>0.05)。结论:住院医师嵴的发生率与患者的性别无相关性,与年龄有相关性,可能与前交叉韧带股骨止点前界受到应力的持续刺激有关,还需进一步研究证实。关节镜下前交叉韧带重建术中,使用住院医师嵴作为股骨端个体化骨性定位标志尚需临床进一步研究。在B组和C组患者术中确认的白色致密纤维切迹,即ACL股骨足印区致密纤维切迹,可以作为ACL重建术中股骨隧道的个体化非骨性定位参考。     

关节镜微创清理术治疗膝关节骨性关节炎

目的探讨关节镜下微创清理术对膝关节骨性关节炎（OA）的治疗效果。方法对54例膝关节骨性关节炎患者进行关节镜下选择性、有限化微创清理术。手术内容包括刨削或射频汽化增生的炎性滑膜组织和前交叉韧带（Anterior Cross Ligment）磨损、游离体取出、软骨打磨成形、增生髁间棘切除、部分骨赘切除、半月板部分切除、髁间窝成形。结果随诊45例。平均18个月（6-24月），大多数患者临床症状明显缓解，关节功能改善。结论关节镜微创清理术可有效缓解OA症状，改善关节功能，提高生活质量。     

Relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch: MRI and arthroscopy correlation

OBJECTIVE: The purpose of this study was to evaluate the relationship between mucoid hypertrophy of the anterior cruciate ligament (ACL) and morphologic change of the intercondylar notch. MATERIALS AND METHODS: We retrospectively reviewed the 105 patients with knee magnetic resonance imaging (MRI) with or without knee arthroscopy [group 1: patients with arthroscopic notchplasty (N = 47), group 2: knee arthroscopy demonstrating intact ACL (N = 33), and group 3: patients with normal knee MRI but no arthroscopy (N = 25)]. Groups 2 and 3 served as an arthroscopic and MR control group, respectively. Two musculoskeletal radiologists reviewed all MR examinations. The intercondylar notch width, notch index (width of intercondylar notch/width of femoral condyle), transverse notch angle (TNA), sagittal notch angle (SNA), and notch area were recorded on axial and sagittal MR images at the midpoint of Blumensaat's line which was identified on sagittal images. The diameter of the ACL was recorded on coronal MR images at the posterior end of Blumensaat's line. RESULTS: The mean values of the intercondylar notch width, notch index, TNA, SNA, notch area, and ACL diameter for the three groups were 16.0 mm/0.2/50.3 degrees /36.5 degrees /249.0 mm(2)/7.7 mm (group 1); 19.3 mm/0.3/52.9 degrees /40.2 degrees /323.4 mm(2)/4.8 mm (group 2); and 20.3 mm/0.3/51.4 degrees /39.1 degrees /350.8 mm(2)/4.5 mm (group 3). The intercondylar notch width, notch index, SNA, and notch area were smaller, and ACL diameter was thicker in group 1 compared with the other groups (p < 0.05). CONCLUSION: Patients with mucoid ACL hypertrophy show a narrower notch, a steeper notch angle, and a smaller notch area than control groups.     

髋关节镜下治疗股骨髋臼撞击综合征的疗效及X线指标分析

目的探讨髋关节镜下治疗股骨髋臼撞击综合征的临床效果,观察X线指标。方法收集2016年2月到2017年2月34例骨髋臼撞击综合征患者为对象,患者均行常规辅助检查和X线片确诊,于髋关节镜下行关节清理和股骨头成形术,比较患者术前和术后1周髋关节Harris功能评分水平及视觉模糊疼痛评分量表(VAS)水平。结果34例患者术前和术后12个月的髋关节ROM测量和VAS评分比较差异有统计学意义(P<0.05)。结论髋关节镜下治疗股骨髋臼撞击综合征,能取得理想的临床效果,促进股骨头颈部弧度的恢复,并且有效缓解患者疼痛,改善关节活动度,具有积极的推广价值。     

Arthroscopic "second look" at the GORE-TEX ligament

We performed an arthroscopic "second look" in 21 knees (20 patients) that had arthroscopic implantation of the GORE-TEX prosthesis for chronic ACL insufficiency. Arthroscopy was done on eight knees at the time of screw removal, eight for knee pain, two for giving way, and three for recurrent effusions. The degree of synovial joint reaction, graft synovial ingrowth, and graft rupture was graded. Microscopic examination was carried out on all biopsies of the GORE-TEX ligament. The average patient age was 30 years and the average time interval from original implantation to second look was 11 months. The GORE-TEX was intact in 11 knees, 10% ruptured in 6, and completely ruptured in 4. There was no correlation between number of GORE-TEX strands ruptured and synovial reaction. No particles of the graft were noted in the synovium if the implant was intact, but particles were noted with graft rupture. We conclude that the intact GORE-TEX ligament is an inert substance and does not cause significant joint reaction. Impingement in the intercondylar notch appeared to be the most common cause of graft failure. Further study is critical to determine the natural history of the GORE-TEX ligament and the knees' response to this prosthetic device.     

Intercondylar roof impingement pressure after anterior cruciate ligament reconstruction in a porcine model

Anterior cruciate ligament (ACL) graft impingement against the intercondylar roof has been postulated, but not thoroughly investigated. The roof impingement pressure changes with different tibial and femoral tunnel positions in ACL reconstruction. Anterior tibial translation is also affected by the tunnel positions of ACL reconstruction. The study design included a controlled laboratory study. In 15 pig knees, the impingement pressure between ACL and intercondylar roof was measured using pressure sensitive film before and after ACL single bundle reconstruction. ACL reconstructions were performed in each knee with two different tibial and femoral tunnel position combinations: (1) tibial antero-medial (AM) tunnel to femoral AM tunnel (AM to AM) and (2) tibial postero-lateral (PL) tunnel to femoral High-AM tunnel (PL to High-AM). Anterior tibial translation (ATT) was evaluated after each ACL reconstruction using robotic/universal force-moment sensor testing system. Neither the AM to AM nor the PL to High-AM ACL reconstruction groups showed significant difference when compared with intact ACL in roof impingement pressure. The AM to AM group had a significantly higher failure load than PL to High-AM group. This study showed how different tunnel placements affect the ACL-roof impingement pressure and anterior-posterior laxity in ACL reconstruction. Anatomical ACL reconstruction does not cause roof impingement and it has a biomechanical advantage in ATT when compared with non-anatomical ACL reconstructions in the pig knee. There is no intercondylar roof impingement after anatomical single bundle ACL reconstruction.     

Correlation between the morphometric parameters of the anterior cruciate ligament and the intercondylar width: gender and age differences

The study was conducted on 50 cadavers (32 male and 18 female, aged 15–53 years; mean 34; SD 11) with intact anterior cruciate ligament (ACL), without diagnosed gonarthrosis of the knee joint. The following anatomical parameters of the ACL were measured: the length of anteromedial and posterolateral bundle, the mean length and the width of the ligament, the length and width of tibial insertion, the length and width of femoral insertion. The intercondylar width was measured at the level of popliteal groove. The width of male intercondylar notch (22 mm) was statistically significantly greater (P < 0.05) than the width of female intercondylar notch (18 mm). The width of the male ACL (12 mm) was significantly greater (P < 0.05) than the width of the female ACL (10 mm). The length of the male ACL femoral insertion (14 mm) was statistically significantly greater (P < 0.05) than in the female ACL femoral insertion (12 mm). Accordingly, with greater width of intercondylar notch, men have wider ACL than women. ACL width is in positive correlation with the male intercondylar notch width but it is not in correlation with the female intercondylar notch width. The width of male intercondylar notch correlates with the length and width of ACL femoral insertion. Taking into account the length and width of femoral insertion in examined cadaver knees, double bundle reconstruction would theoretically be possible in 76% of cases.     

ACL–PCL and intercondylar notch impingement: magnetic resonance imaging of native and double-bundle ACL-reconstructed knees

Purpose

The purpose of this study was to: (1) define the relationship between the ACL and PCL in normal knees; (2) determine whether ACL–PCL impingement occurs in native knees; and (3) determine whether there is a difference in impingement between double-bundle reconstructed and native knees.

Methods

Eight subjects were identified (age 20–50; 6 females, 2 males). All were at least 1-year status postanatomic double-bundle ACL reconstruction (allograft; AM = 8 mm; PL = 7 mm) and had no history of injury or surgery to the contralateral knee. MRIs of both knees were performed with the knee at 0 and 30° of flexion. The images were evaluated by a non-treating surgeon and two musculoskeletal radiologists. Coronal and sagittal angles of AM and PL bundles, Liu’s PCL index and the distance between ACL and PCL on modified axial oblique images were recorded. Impingement was graded (1) no contact; (2) contact without deformation; or (3) contact and distortion of PCL contour.

Results

Seventy-five percent (6) of the native ACL’s showed no contact with the roof of the intercondylar notch or PCL, compared to 25 % (2) of the double-bundle reconstructed ACLs. One double-bundle reconstructed ACL showed intercondylar notch roof and ACL–PCL impingement (12.5 %). Significant differences were found between the native ACL and the double-bundle reconstructed ACL for the coronal angle of the AM (79° vs. 72°, p = 0.002) and PL bundle (75° vs. 58°, p = 0.001). No differences in ROM or stability were noted at any follow-up interval between groups based on MRI impingement grade.

Conclusion

ACL–PCL contact occurred in 25 % of native knees. Contact between the ACL graft and PCL occurred in 75 % of double-bundle reconstructed knees. ACL–PCL impingement, both contact and distortion of the PCL, occurred in one knee after double-bundle reconstruction. This study offers perspective on what can be considered normal contact between the ACL and PCL and how impingement after ACL reconstruction can be detected on MRI.

Level of evidence

Cohort Study, Level III.     

Symptomatic mucoid degeneration of the anterior cruciate ligament

Purpose

Mucoid degeneration of the anterior cruciate ligament (ACL) is a little-known entity. The aim of this study was to detail the clinical, radiological, arthroscopic and pathological findings of this condition and to report clinical outcomes following arthroscopic partial excision of the ACL.

Methods

Between 1999 and 2009, 80 knees in 78 patients were diagnosed as having mucoid degeneration of the ACL based on MRI and clinical findings, and subsequently underwent arthroscopic treatment. Of these, 68 knees in 66 patients, with a median age of 51 years (range, 35–75 years), were followed-up for at least one year.

Results

All patients had insidious onset of knee pain, while 56 knees (82 %) had associated extension deficits and 36 knees (53 %) had restricted flexion. MRI findings typically showed diffuse thickening and increased signal intensity of the ACL. Arthroscopic examination revealed notch impingement and bulging of hypertrophied ACL into lateral compartments. Associated lesions included meniscal tears in 33 knees and chondral lesions of at least Outerbridge grade 2 in 56 knees. All knees underwent arthroscopic partial excision of the hypertrophied ACL, with three undergoing preoperative and 30 undergoing concomitant meniscectomies. Pain relief was achieved in 58 of 62 knees (94 %) following partial excision of the ACL. Extension deficits were normalized in 49 of 56 knees (88 %), and restricted flexion was normalized in 33 of 36 affected knees (92 %). Four knees of four patients had postoperative symptoms of anterior instability.

Conclusions

Pain and limitation of motion due to mucoid degeneration of the ACL can be improved by arthroscopic partial excision of the ACL with or without notchplasty. However, one potential complication is the development of postoperative symptoms of anterior instability.

Level of evidence

Retrospective study, Level IV.     

Light and scan electron microscopic analysis of cyclops syndrome: etiopathogenic hypothesis and technical solutions

The loss of range of motion after anterior cruciate ligament (ACL) reconstruction is one of the most common and most challenging complications of this kind of surgery. Recently, an intercondylar notch fibrous proliferation, called cyclops syndrome because of its arthroscopic appearance, has been identified as one of the specific causes of loss of extension. The incidence of cyclops syndrome is 2%–4% [17, 18], but there is still no understanding of its etiology. We speculate on the etiology and suggest some technical solutions to reduce this complication. In 180 patients submitted to arthroscopic ACL reconstruction with patellar tendon, we observed in 4 cases a fibrous nodule adherent to the neoligament that caused a loss of extension between 12° and 17°. In all cases, arthroscopic removal of this nodule solved completely the loss of articular motion. The nodules were subjected to light and scanning electron microscope evaluation. We observed numerous, newly formed vessels in all 4 nodules. These vessels were made up of hyperplastic and hypertrophic cells and were surrounded by bundles of disorganized fibrous tissue. No inflammatory cells or bone or cartilaginous tissue was observed. We hypothesize a microtraumatic genesis for cyclops syndrome. Repeated microtraumas expose the graft collagen fibers, which can lead to productive inflammatory process and thence to the formation of the cyclops nodule. We suggest some technical solutions to avoid graft impingement with the notch and with the tibial bone tunnel.     

MRI findings in Dyggve-Melchior-Clausen syndrome, a rare spondyloepiphyseal dysplasia

We present the case of an 8-year-old female patient with bone dysplasia as part of Dyggve-Melchior-Clausen syndrome (DMCS). MRI was used to evaluate the case. In the spine, odontoid apophysis aplasia was found with no ossification nucleus, vertebrae with central hump, disk protrusions, hypertrophy of the posterior common vertebral ligament, and hidden spina bifida at the S4 level. Morphological anomalies were found in the hips both in the proximal femoral epiphysis, which was located excentrically and laterally to the femoral neck, and in the Y-cartilage, which was greatly enlarged. In the knees, anterior crossed ligaments were not seen, although there were some indirect signs that indicated congenital absence, including hypoplasia of the femoral trochlea and the intercondylar notch. There was bilateral medial patellar plicae and asymmetry in the height of the distal femoral and proximal tibial physes, as well as dysplasia of the facets of the patella. In comparison with radiography, MRI provides a much clearer definition of the aspects of bone dysplasia that are related to DMCS, including morphological changes in the soft tissue and cartilage of the spine, hips, and knees. MRI can enhance our understanding of the pathogenesis and evolution of deformities.