Intraarticular fibrous nodule as a cause of loss of extension following anterior cruciate ligament reconstruction.

Loss of motion is a well-known complication following anterior cruciate ligament (ACL) reconstruction. We have found that loss of extension is more disabling than loss of flexion, and is a more common problem following arthroscopic assisted ACL reconstruction. We are reporting on a group of 21 patients who have developed restricted knee extension following ACL reconstruction utilizing either the central one-third of the patellar ligament or the hamstring tendons as an autogenous graft. The patients presented at an average of 4 months postoperatively with a clinical syndrome of loss of extension associated with pain at terminal extension, crepitus, and grinding with attempted extension beyond their limit. The consistent finding at arthroscopy was a fibrous nodule occupying the intercondylar notch, varying in size from 1 x 1 to 2 x 3 cm, and presenting a mechanical block to full extension. It appears that anterior placement of the graft, particularly on the tibia, results in injury to the graft and subsequent nodule formation. Removal of the nodule resulted in improvement of an average preoperative loss of extension of 11 degrees, to 3 degrees at surgery, and 0 degrees at 1 year follow-up. The average side-to-side difference in terminal extension at final examination, using the uninvolved limb for comparison, was 3 degrees. Histology was available for review on 19 of the 21 patients operated on. The consistent microscopic finding within the nodule was the presence of disorganized dense fibroconnective tissue that, with time, underwent modulation to fibrocartilage. It is postulated that this occurs in response to compressive loading of the nodule.     

Cyclops syndrome: loss of extension following intra-articular anterior cruciate ligament reconstruction

Arthrofibrosis is one of the recognized complications following traditional anterior cruciate ligament (ACL) reconstruction. With the advent of arthroscopic assisted ACL reconstructions, the extent of potential arthrofibrosis appeared to be less. However, 13 patients after intra-articular ACL reconstruction using a patella tendon autograft developed a similar symptom complex. In addition to postoperative loss of full extension, there was an audible and palpable clunk with terminal extension. These patients had similar arthroscopic findings of a nodule that formed anterolateral to the tibial tunnel placement of the graft. The arthroscopic appearance of the soft tissue mass with its surface vessels was reminiscent of a "cyclops." After arthroscopy with debridement and manipulation of the knee, extension was improved in all cases. The average range of motion immediately after the procedure was 6.0-130 degrees, compared with 16-103 degrees preoperatively. The range of motion at last follow-up averaged 3.8 degrees of extension and 138 degrees of flexion. All patients had greater than 130 degrees of flexion. There were no complications attributed to the manipulation and arthroscopic lysis of adhesions, and no patient experienced loss of graft integrity or knee stability. The "cyclops" nodule was examined grossly and microscopically and demonstrated peripheral fibrous tissue with a central region of granulation tissue in all specimens. In addition, two specimens were noted to include bony fragments and three specimens contained cartilaginous tissue.     

Magnetic resonance evaluation of remodeling process in patellar tendon graft

Several studies have shown the accuracy of magnetic resonance imaging in evaluating the reconstructed anterior cruciate ligament. The purpose of the current study was to clarify the clinical usefulness of magnetic resonance imaging for evaluating the reconstructed anterior cruciate ligament in comparison with using arthroscopy. Sixty-nine patients who had an anterior cruciate ligament reconstruction using a bone-tendon-bone autograft were examined by magnetic resonance imaging and arthroscopy an average of 12 months after surgery. There were 41 males and 28 females with an average age of 25.9 years (range, 15-66 years). The interval from surgery to the magnetic resonance imaging or arthroscopic evaluation was a mean of 12 months (range, 4-32 months). The magnetic resonance imaging findings of the reconstructed anterior cruciate ligament were classified as either high, intermediate, or low intensity. The arthroscopic findings also were classified as either graft impingement at the intercondylar notch or no impingement. In the 47 anterior cruciate ligament grafts that were not impinged, the signal intensity remained low and did not increase during second-look arthroscopy. In contrast, 22 anterior cruciate ligament grafts that were impinged showed an increased signal intensity in the distal area of the graft at the time of the second-look arthroscopy. Furthermore, no significant correlation was observed between the presence of a high signal intensity and postoperative instability. The high signal intensity of the anterior cruciate ligament graft on magnetic resonance imaging was found to be caused by graft impingement. These findings therefore show a clear association between graft impingement and the subsequent appearance of the graft on magnetic resonance imaging.     

Reflex extension loss after anterior cruciate ligament reconstruction due to femoral “high noon” graft placement

We describe a rare case of a painful reflex extension loss due to femoral malplacement of an anterior cruciate ligament (ACL) graft in a female high-level athlete. The graft was placed on the femoral site in the “high noon” position combined with a slight medial tibial tunnel placement. The resulting anterior-posterior cruciate ligament impingement near extension caused a persistent functional extension deficit of 20°. Under anesthesia, the extension loss diminished, and thus it was hypothesized that the ACL-PCL impingement during extension activates a proprioceptive reflex leading to a functional extension loss while the patient is awake. After sacrifice of the graft and subsequent replacement of the ACL, full range of motion was achieved within 2 months. After a 3-year postinjury history of 3 arthroscopies and 2 ACL reconstructions, the athlete reached her preinjury activity level again. This rare cause of a reflex extension loss due to femoral high noon graft placement has not been described previously and should be included as a differential diagnosis when evaluating patients with an extension deficit after ACL reconstruction.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 4 (April), 2001: pp 408–411     

关节镜下髁间窝成形术治疗髁间窝撞击综合征

目的探讨关节镜下髁间窝成形术治疗髁间窝撞击综合征致膝关节疼痛及伸直功能受限的疗效。方法 2008年2月至2009年7月行关节镜下髁间窝扩大成形术治疗45例骨关节炎并伴有髁间窝撞击综合征患者,男15例,女30例;年龄46～67岁,平均56.6岁。结果全部获得随访,随访时间6～12个月。平均8个月,患者膝关节疼痛明显缓解或消失,膝关节伸直功能较术前得到明显改善。结论关节镜下髁间窝扩大成形术治疗髁间窝撞击综合征所致膝关节疼痛及伸直功能受限有明显疗效。     

Arthroscopic evaluation of allograft anterior cruciate ligament reconstruction.

In a previous study, we evaluated the findings of arthroscopic second looks at open anterior cruciate ligament reconstructions using autogenous tissue. We were disappointed at the variable quality of the ligaments and the presence of articular cartilage lesions. These findings led us to change our treatment protocol. Since 1983, we have used freeze-dried allografts for arthroscopic intraarticular ACL reconstructions. We have started protected motion in a brace immediately postoperatively and delayed weightbearing for 12-16 weeks. A total of 54 patients with at least a 2-year follow-up were evaluated subjectively (Lysholm scale) and objectively (KT 1000). Some 78% were rated good or excellent, and 87% were satisfied with their surgery. Of these 54 patients, 28 underwent subsequent surgery for hardware removal, manipulation, or removal of adhesions. All 28 had an arthroscopy, and an evaluation of ligamentous tissue and articular cartilage at the time of the second surgery. The graft resembled a normal anterior cruciate ligament in 18 patients. The graft was slightly lax in two of these patients, but their clinical examination revealed normal stability. In six patients, the intercondylar notch was covered by a sheath of dense, fibrous tissue, but the knees were stable. In two cases, there was slight fraying of the lateral aspect of the graft from impingement on the lateral femoral condyle. In two cases the graft failed. The condition of the articular cartilage was documented and compared with the condition of the articular cartilage at the time of cruciate reconstruction. In 19 cases, the articular cartilage had been normal and remained normal at the time of reevaluation.(ABSTRACT TRUNCATED AT 250 WORDS)     

前十字韧带移植重建后移植物撞击新类型

 目的 通过双源CT三维重建前十字韧带（anterior cruciate ligament,ACL）移植重建后的移植物和骨隧道,分析移植物撞击症。方法 2012年11月至2014年11月,采用双源CT对134例ACL移植重建后患者的膝关节进行扫描,三维重建股骨和胫骨隧道、ACL重建移植物等。其中单束重建118例,男83例,女35例;年龄15~64岁,平均32岁。观察重建术后移植物是否受到撞击、撞击来源并进行分类;分别测量股骨、胫骨隧道的相对位置,并对有撞击与无撞击组患者进行统计比较。结果 基于双源CT移植物重建,根据ACL移植重建后移植物是否受到撞击分组,无撞击组39例（33%,39/118）,有撞击组79例（67%,79/118）。存在撞击者再根据撞击部位分为髁间窝出口撞击组77例（占总数的65%,占撞击组的97%）和髁间窝顶中途撞击组2例（占总数的2%,占撞击组的3%）。进一步根据撞击来源不同,再对髁间窝出口撞击组分为3个亚型,即鸟喙撞击10例（3%,10/77）、胫骨平台撞击46例（60%,46/77）、钳夹撞击21例（27%,21/77）。单因素方差分析显示,鸟喙撞击、胫骨平台撞击、钳夹撞击各组与无撞击组的股骨、胫骨隧道位置均无显著性差异。结论 基于双源CT三维重建ACL术后移植物扫描发现3种新的移植物撞击类型, 即髁间窝顶中途撞击、胫骨撞击和钳夹撞击。     

关节镜下儿童胫骨髁间棘骨折的微创治疗

目的：分析儿童胫骨髁间棘骨折的特点,介绍关节镜辅助下微创治疗的方法。方法：对2004年1月至2008年12月12例儿童胫骨髁间棘骨折进行回顾性分析。按照Meyers-McKeever骨折分型：Ⅰ型1例,Ⅱ型4例,Ⅲ型7例。新鲜骨折10例,陈旧骨折2例;男10例,女2例;年龄8～13岁,平均10岁。所有病例进行了关节镜探查、复位,克氏针固定。随访时间10～36个月,了解骨折愈合、关节活动度、膝关节稳定性等情况。合并半月板损伤1例,滑车区软骨损伤1例,半月板嵌入骨块下5例。结果：骨折愈合时间平均5周,无畸形愈合、骨不连,无髁间窝撞击表现。术后3个月Lysholm膝关节功能评分平均（92.7±2.5）分,术后6个月平均（96.4±1.7）分,所有患膝恢复健侧活动度。结论：儿童胫骨髁间棘骨折以Ⅱ、Ⅲ型多见,软骨及半月板等关节內合并伤少见。关节镜辅助下交叉克氏针固定法操作简便、手术创伤小、恢复快,符合儿童骨生长快的特点。     

Contact pressure and tension in anterior cruciate ligament grafts subjected to roof impingement during passive extension

Contact between an anterior cruciate ligament graft and the intercondylar roof has been termed roof impingement. Grafts with impingement sustain permanent damage, and if the injury is extensive enough, then the graft may fail, causing recurrent instability. This study evaluated two mechanical factors that could be responsible for the graft injury associated with roof impingement: an increase in graft tension or elevated pressures between the graft and the roof, or both. An anterior cruciate ligament reconstruction was performed using an Achilles tendon graft in five fresh-frozen cadaveric knees. Using a six-degree-of-freedom load application system, the anterior displacement of the knee with the native anterior cruciate ligament was restored in the reconstructed knee at a flexion angle of 30° and with an anterior force of 200 N applied. Pressure between the graft and intercondylar roof, graft tension, and flexion angle were measured during passive knee extension for three tibial tunnel placements (anterior, center, and posterior). Intercondylar roof impingement increased the contact pressure between the graft and the roof but had no significant effect on graft tension. Therefore, during passive knee extension, the contact pressure between the anterior cruciate ligament graft and the intercondylar roof is a more likely cause of graft damage than increased graft tension.     

Mucoid degeneration of the anterior cruciate ligament

PurposeMucoid degeneration of the anterior cruciate ligament (ACL) is not a well-known entity. Only 1 case of mucoid degeneration of the ACL has been reported in the English-language literature. This article describes 5 cases of mucoid degeneration of the ACL with clinical features, magnetic resonance imaging (MRI) findings, and a method of arthroscopic management of these cases.Type of studyCase series.MethodsOver a period of 21 months from 1999 to 2001, 5 patients were diagnosed to be suffering from mucoid degeneration of the ACL using MRI, histopathologic, and arthroscopic criteria. All patients presented with progressive knee pain and restriction of flexion without history of a significant trauma or instability preceding the symptoms. MRI showed an increased signal in the substance of the ACL both in the T1- and T2-weighted images, with a mass-like configuration that was reported as a partial or complete tear of the ACL by most radiologists. At arthroscopy, the ACL was homogenous, bulbous, hypertrophied, and taut, occupying the entire intercondylar notch. The ligamentum mucosum was absent in all patients. A debulking of the ACL was performed by a judicious excision of the degenerate mucoid tissue, taking care to leave behind as much of the intact ACL as possible. Releasing it and performing a notchplasty treated impingement of the ACL to the roof and lateral wall. The ACL was not fully excised in any of the patients.ResultsAll patients were pain free and had recovered full flexion except one who experienced painful flexion beyond 120°. None of the patients showed symptoms of instability. Postoperative MRI performed after at least 12 months in 2 patients showed some intact ACL fibers in a now-thinned ACL mass.ConclusionsMucoid degeneration of the ACL is a clinical condition afflicting active middle-aged people without a single significant traumatic episode with a specific MRI picture. They respond well to a judicious arthroscopic release of the ACL with notchplasty.Level of evidenceLevel IV.     

Arthroskopische Arthrolyse bei Arthrofibrose nach Ersatzplastik des vorderen Kreuzbandes

Objective

Restoration of free knee motion taking into account knee extension, knee flexion, and patella mobility.

Indications

Prolonged knee motion restriction after anterior cruciate ligament (ACL) reconstruction, persistent decreased patella mobility, or extension deficit.

Contraindications

Existing significant joint irritation or active reflex dystrophy with persistent distinctive pain syndrome.

Surgical technique

Arthroscopic arthrolysis possible in most cases. Removal of adhesions in all compartments. Elimination of intraarticular cause of patella infera by removing infrapatellar scar tissue and fibrotic fat pad. In case of severe peripatellar fibrotic tissue, lateral release is useful with partial transection of lateral retinacula. In case of strong capsular contracture, additional medial release indicated to improve patella mobility. Important goal of arthrolysis: full range of knee extension. Arthrolysis for scar tissue removal in the posterior recessus through dorsomedial arthroscopic approach possible. In severe cases posteromedial arthrotomy for posterior capsule release required. Cyclops syndrome makes removal of all tissue adherent to the ACL necessary. An irregular ACL insertion or intercondylar notch stenosis may require notchplasty. Postoperative recurrence of fibrosis may require repeated arthroscopic surgery to improve mobility, such as notchplasty, osteophytes resection, scar removal, and releases.

Postoperative management

Immediate postoperative pain-free physical therapy taking into account full range of extension and patella mobility. Passive exercises under traction. Lymphatic drainage. No exercising in pain throughout the entire postoperative physical therapy. Continuous passive motion treatment for 4 weeks postoperatively useful. No muscle strength or equipment training for at least 3 months postoperatively.

Results

Based on the observations in our working group, approximately pproximately 78?% of patients develop knee osteoarthritis within 5 years.     

Decreased range of motion following acute versus chronic anterior cruciate ligament reconstruction

Eighty patients with acute anterior cruciate ligament (ACL) reconstruction were compared to 80 patients with chronic ACL reconstruction. Before reconstruction, all patients had 0 degrees-120 degrees active motion, performed a straight leg raise without loss of extension, and demonstrated good quadriceps control. At 3 months, 4 acute patients had decreased range of motion (<10 degrees-120 degrees), but none at 6 or 12 months, and did not require repeat surgery. One chronic patient had decreased range of motion at 3 and 6 months and 1 patient had decreased range of motion at 1 year; both patients required operative intervention. Using these specific preoperative criteria, no increased incidence of decreased range of motion was found when an ACL reconstruction was performed within 3 weeks of injury.     

The early treatment of motion complications after reconstruction of the anterior cruciate ligament.

The use of active and passive knee motion in the immediate postoperative period and a treatment plan for early postoperative limitations in knee motion has proven highly effective in restoring motion after anterior cruciate ligament (ACL) reconstruction. Of 207 knees, 189 (91%) regained a full range of motion of 0 degrees-135 degrees. The remaining 18 knees (9%) did not regain motion as rapidly as the others and were placed in an early postoperative phased treatment program. Six knees had serial extension casts, nine had early gentle manipulation under anesthesia, and three had arthroscopic lysis of intraarticular adhesions and scar tissue. Fourteen of these 18 knees regained a full range of knee motion. Two of the remaining four knees lacked 5 degrees of full extension, whereas the other two, in patients who had failed to follow medical advice and the rehabilitation program, had permanent and significant limitation of motion. The incidence of postoperative motion problems was related to the extent of the surgical procedure. The incidence was 4% in patients who had only ACL reconstruction, 10% in cases in which added lateral extraarticular procedure had been done, 12% where a meniscus repair had been done, and 23% where a medial collateral ligament repair was done.     

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 16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 ,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 19 5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有效方法     

Intra-articular mechanical blocks and full extension in patients undergoing anterior cruciate ligament reconstruction.

Patients with acute anterior cruciate ligament (ACL) rupture frequently present with a lack of full extension. Current literature is unclear whether arthroscopic debridement is necessary before reconstruction to achieve full extension postoperatively. This study examined the postoperative extension achieved in 153 knees that underwent ACL reconstruction within 12 weeks of index injury. All patients performed preoperative physical therapy to increase range of motion and control pain/swelling, regardless of presenting range of motion without prior aspiration or arthroscopy. Of the 153 knees, 103 had meniscal pathology, of which 73 were peripheral vertical tears; 96 of the 153 knees lacked >/=3 degrees extension preoperatively. Five of 96 knees had an intra-articular mechanical block to extension and all regained full extension after ACL reconstruction. This study documented that a true intra-articular mechanical block is unusual in primary ACL ruptures. Lack of full extension can be adequately dealt with during surgical reconstruction without a detrimental effect on knee extension postoperatively.     

Preliminary clinical results of two techniques for addressing graft tunnel mismatch in endoscopic anterior cruciate ligament reconstruction

This study reports the initial clinical results of 540 degrees of graft rotation or free tibial bone block to address graft tunnel mismatch in endoscopic anterior cruciate ligament (ACL) reconstruction. The operative reports of patients who underwent endoscopic ACL reconstruction between 1999 and 2001 were reviewed. Nine of 11 patients treated with a free tibial bone block and 14 of 17 patients treated with 540 degrees of graft rotation were evaluated. Mean follow-up was 20 months (range: 13-40 months) for the bone block group and 34 months (range: 18-48 months) for the 540 degrees group. There were statistically significant improvements in physical examination test results postoperatively, and only one patient in the 540 degrees group had a grade one positive pivot shift test. KT-1000 arthrometer testing demonstrated a statistically significant decrease in manual maximum and side-to-side differences at final follow-up. Mean Lysholm and Noyes sports function scores were excellent or good for all patients. One patient required reoperation for flexion contracture, one patient required an arthroscopic irrigation and debridement for a minor infection, and one patient required arthroscopic subtotal medial meniscectomy for failed meniscal repair. No difference was noted between these results and previous results of patients undergoing conventional endoscopic ACL reconstruction. These results demonstrate graft rotation and free bone block techniques are effective in addressing graft tunnel mismatch in endoscopic ACL reconstruction.     

Arthroscopic evaluation after surgical repair of intercondylar eminence fractures

Introduction Patients who undergo surgical repair of intercondylar eminence fracture may have postoperative problems despite good reduction. We used arthroscopy to evaluate the outcomes after surgery to repair intercondylar eminence fractures. Materials and methods Ten patients (8 men and 2 women; average age at the time of surgery 27.9 ± 10.0 years, range from 14 to 50 years) with fracture of the tibial intercondylar eminence underwent an arthroscopic reduction and internal fixation with non-absorbable sutures. Preoperative radiological examination showed that there were one Meyer’s type-II, eight type-IIIA and one type-IIIB fractures. Clinical symptoms and physical findings for all the patients were evaluated 1 year postoperatively. Radiographic assessment and the Lysholm rating scale were also utilized. Second-look arthroscopy was performed after 1 year when removing the implant. Arthroscopy was used to assess the appearance of the surface of the anterior cruciate ligament (ACL), check for the existence of cyclops and look for interposition of tissue in the lateral and medial joint spaces. Results One year after the surgery, all ten patients achieved bony union and had negative Lachman and anterior drawer tests. The average Lysholm knee score was 94.5 ± 7.2 points (range 100–75 points). Arthroscopy showed an irregular surface on the ACL in two of the ten patients, cyclops in two patients, interposition in the lateral joint space in two patients and interposition in the medial joint space in one patient. In the two cases seen with an irregular surface, the ACL was covered with droopy fibrous tissue, but the substance of the ACL was intact. The two patients who had cyclops showed loss of knee extension (5°∼10°), which was regained by subsequent resection of the cyclops. One patient who had an interposition into the lateral joint space complained of catching, which was released by resection of the interposing tissue. Conclusion Arthroscopic refixation of the intercondylar eminence fracture provided bony union and a good clinical outcome. Cyclops syndrome is one of the causes of loss of knee extension, and soft tissue in the medial or lateral compartment is one of the causes of catching of knee after surgical repair of intercondylar eminence fracture. Cyclops syndrome, which may occur following ACL reconstruction, is one of the causes of loss of knee extension after surgical repair of intercondylar eminence fracture. In patients who have knee complaints, such as catching and loss of knee extension, a second-look arthroscopy is useful for identifying and correcting the problem.     

Editorial Commentary: Risk Factors of Cyclops Syndrome in Quadriceps Autograft Anterior Cruciate Ligament Reconstruction: More Helpful Data in Weighing Graft Choice

Arthrofibrosis after anterior cruciate ligament (ACL) reconstruction can be a devastating complication with risk factors and causes not well established. Cyclops syndrome is a subtype involving localized scar anterior to the graft, which is typically treated with arthroscopic debridement. ACL quadriceps autograft is a newly popular graft option for which clinical data continue to develop. However, recent research shows possible increased risk of arthrofibrosis with quadriceps autograft. Possible causes include inability to achieve active terminal knee extension after extensor mechanism graft harvesting; patient characteristics, including female sex, and social, psychological, musculoskeletal, and hormonal differences; larger graft diameter; concomitant meniscus repair; exposed collagen fibers of the graft abrading the fat pad or tibial tunnel or intercondylar notch; smaller notch size; intra-articular cytokine; and biomechanical stiffness of the graft.     

A synovial osteochondroma replacing the anterior cruciate ligament at the intercondylar notch

A woman presented with knee pain and locking. Pain was exacerbated at the end of the range of motion, especially during extension, with locking symptoms similar to those associated with a meniscus bucket handle tear. Ligamentous laxity was not definite. Plain radiographs showed multiple calcified loose bodies. Magnetic resonance imaging (MRI) showed a lobulated mass that was hypointense to muscle on T1-weighted sequences and hyperintense to muscle on T2-weighted sequences in the anterior cruciate ligament (ACL). Arthroscopically, multiple loose bodies were observed in the intercondylar notch and posterolateral compartment. A huge mass replaced the normal ACL and was caught in the intercondylar notch. The mass in the intercondylar notch caused loss of extension range of motion (ROM) because the piece caused a mechanical blockage. However, the loss of flexion ROM was likely caused by a loss of elasticity of the ligament rather than mechanical blockage. We resected the ACL mass, and removed the free bodies from the posterolateral corner. It was not possible to preserve the ACL fibers. Histological examination confirmed a diagnosis of osteochondromatosis. All symptoms resolved postoperatively. At 20 months postoperatively, the patient was pain free and had regained full knee motion without recurrence evidenced by follow-up MRI. However, ACL removal caused the knee instability. To date the patient has not undergone ACL reconstruction because she prefers conservative treatment and has experienced little discomfort in activities of daily living. To our knowledge, this is the first report to describe synovial osteochondromatosis wholly replacing the ACL fibers and causing mechanical blocking of both extension and flexion.     

基于MRI二维影像下股骨髁间窝的三维可视化研究

目的通过MRI二维影像对股骨髁间窝进行三维重建及测量,探讨虚拟股骨髁间窝成形术的可行性。方法 2009年9月-12月募集健康志愿者30名,男、女各15名,年龄20～30岁,身高150～185 cm,体重45～74 kg。排除膝关节疾病和手术史。根据性别不同将研究对象分为男性组和女性组,并将同性别的膝关节分为左膝及右膝2个亚组。对30名志愿者行双膝关节MRI扫描,将MRI二维图像导入交互式医学影像控制系统Mimics10.01,并对膝关节进行三维重建,通过三维图像测量获取髁间窝相关解剖学数据:髁间窝宽度(notch width,NW),内、外股骨髁宽度(condylar width,CW),髁间窝指数(notch width index,NWI)。收集2010年1月-3月收治的前交叉韧带(anteriorcruciate ligament,ACL)损伤患者膝关节三维图像,筛选出4例髁间窝狭窄(NWI≤0.2)的患者,在患者膝关节三维图像上虚拟髁间窝成形术,计算截骨厚度,并在ACL重建术中实施,评估移植物与髁间窝的撞击情况。结果男性组与女性组双侧股骨髁间窝三维模型的NW、CW比较差异均有统计学意义(P<0.05),NWI比较差异无统计学意义(P>0.05)。男性组内及女性组内左、右膝股骨髁间窝三维模型的NW、CW、NWI比较差异均无统计学意义(P>0.05)。在ACL重建术中,根据术前测量结果行髁间窝成形术后患者的NWI达正常值(NWI>0.22),韧带重建后关节镜观察以及术后3个月随访时行基于MRI二维图像的数字化三维重建膝关节模型并测量发现重建韧带与髁间窝无撞击。结论计算机三维重建模型与实体的髁间窝形态有较高相似度,NWI可较好地反映髁间窝狭窄程度;计算机虚拟髁间窝成形术可为ACL重建提供术前参考,以避免术后移植物与髁间窝的撞击。