Triple plating of tibia in a complex bicondylar tibial plateau fracture

High-energy tibial plateau fracture poses a significant challenge and difficulty for orthopaedic surgeons. Fracture of tibial plateau involves major weight bearing joint and may alter knee kinematics. Anatomic reconstruction of the proximal tibial articular surfaces, restoration of the limb axis （limb alignment） and stable fixation permitting early joint motion are the goals of the treatment. In cases of complex bicondylar tibial plateau fractures, isolated lateral plating is frequently associated with varus malalignment and better results have been obtained with bilateral plating through dual incisions. However sometimes a complex type of bicondylar tibialplateau fractures is encountered in which medial plateau has a biplaner fracture in posterior coronal plane as well as sagittal plane. In such fractures it is imperative to fix the medial plateau with buttressing in both planes. One such fracture pattern of the proximal tibia managed by triple plating through dual posteromedial and anterolateral incisions is discussed in this case report with emphasis on mechanisms of this type of injury, surgical approach and management.     

Pure Varus Injury to the Knee Joint

A 30-year-old male was involved in a car accident. Radiographs revealed a depressed marginal fracture of the medial tibial plateau and an avulsion fracture of the fibular head. Magnetic resonance imaging showed avulsion fracture of Gerdy''s tubercle, injury to the posterior cruciate ligament (PCL), posterior horn of the medial meniscus, and the attachments of the lateral collateral ligament and the biceps femoris tendon. The depressed fracture of the medial tibial plateau was elevated and stabilized using a cannulated screw and washer. The injured lateral and posterolateral corner (PLC) structures were repaired and augmented by PLC reconstruction. However, the avulsion fracture of Gerdy''s tubercle was not fixed because it was minimally displaced and the torn PCL was also not repaired or reconstructed. We present a unique case of pure varus injury to the knee joint. This case contributes to our understanding of the mechanism of knee injury and provides insight regarding appropriate treatment plans for this type of injury.     

Medial and lateral segond fractures in a skeletally immature patient: a radiographic marker for the multiply injured knee

Marginal fractures of the medial tibial plateau have been reported in the literature as a secondary type of Segond fracture. Some reports described this entity in the setting of combined injuries such as root avulsions of the medial meniscus, complete disruption of the posterior cruciate ligament (PCL), partial tear of the anterior cruciate ligament (ACL), and tears of the medial meniscus and medial collateral ligament. It has been postulated that medial marginal fractures are secondary to compression of the medial aspect of the femoral condyle and tibial plateau with a corresponding posterolateral corner injury. However, this mechanism of injury may not always be as straightforward.This article presents a case of an alternate injury pattern in a skeletally immature patient. A 16-year-old boy sustained a varus force and twisting injury to his knee, resulting in radiographic evidence of multiple avulsion fractures of the knee, including a fibular epiphyseal avulsion fracture and medial and lateral Segond fractures. Usually, the avulsion fractures serve as markers for significant ligamentous injuries in adult patients, but our patient had minimal injury to the PCL, ACL, and posterolateral corner. Further physical examination and imaging studies revealed an anterior horn root avulsion, meniscocapsular separation, and anterior cortical rim fracture. A combination of imaging modalities helped us further characterize the injury pattern to devise the optimal surgical plan, especially the fixation of the anterior cortical fracture of the tibia.     

Ligament injuries associated with tibial plateau fractures

Thirty-nine patients with tibial plateau fractures and concomitant ligament injury were evaluated at least one year after injury. Ligamentous injury was determined by stress roentgenograms, plain roentgenograms, operative findings, and Pelle-grini-Stieda's ossification. There were 22 isolated medial collateral, eight lateral collateral, one isolated anterior cruciate, and eight combined ligament injuries. All types of tibial plateau fractures were associated with ligamentous injury, although split compression and local compression were most common. Twenty patients (Group 1) did not have operative repair of the injured ligaments, and 19 patients (Group 2) had primary repair of the injured ligaments. Open reduction and internal fixation of the plateau fracture(s) were performed in 13 patients in Group 1 and 19 patients in Group 2. Follow-up evaluation (100-point scale), including subjective, functional, and anatomic factors, revealed 12 excellent and good, four fair, and three poor results in the 19 patients with ligamentous repair. There were ten excellent and good, two fair, and eight poor results in those without ligament repair. Ten of the 12 patients with 10 degrees or more of instability had poor results. These poor results included five unrepaired medial collateral ligaments, two unrepaired lateral collateral ligaments, and three patients with cruciate ligament injury. This study confirms the view that instability is a major cause of unacceptable results in tibial plateau fractures. Operative repair of medial and lateral collateral ligaments, with appropriate treatment of the bony plateau fracture, may reduce late instability and may improve overall morbidity in these concomitant injuries. Cruciate ligament injury associated with a tibial plateau fracture carries a poor prognosis.     

Injuries to the posterolateral aspect of the knee accompanied by compression fracture of the anterior part of the medial tibial plateau

We present 12 cases of patients with injury to the posterolateral aspect of the knee accompanied by a compression fracture of the anterior part of the medial tibial plateau. There were 11 male patients and 1 female patient with an average age of 26 years (range, 17 to 44 years). There were 4 cases of posterolateral rotatory instability and 8 cases of straight lateral instability of the knee. The size of the compression fracture was classified into 2 types, small (8 cases) and large (4 cases). Although the mechanism of injury was considered to be hyperextension and varus force, the pattern of cruciate ligament injuries varied from case to case. The following 3 questions should be considered to determine which cruciate ligament is damaged: (1) Was the ipsilateral foot fixed to the ground? (2) Was forward inertia involved? (3) Was there a direct blow to the anteromedial aspect of the tibia or to the femur? Accompanied fractures of the medial tibial plateau were considered to have been compressed by the medial femoral condyle. The size of the accompanying compression fracture varied; 7 of 8 cases with a small-type fracture had posterior cruciate ligament injuries and 3 of 4 cases with a large-type fracture had anterior cruciate ligament injuries. The size of the fracture is determined by which point of the medial tibial plateau touched the medial femoral condyle. We propose that a compression fracture of the anterior part of the medial tibial plateau indicates a coexistent posterolateral aspect injury, and that especially a small compression fracture strongly suggests an accompanying posterior cruciate ligament injury, as well.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 6 (July-August), 2001: pp 642–647     

Avulsion fracture of the anteromedial bundle of the anterior cruciate ligament

The avulsion fracture of the tibial attachment site of the anterior cruciate ligament is relatively rare among adults. Although partial avulsion fracture of this site is very rare, complex forces exerted on the knee joint could produce this type of fracture. We report on an adult patient with an avulsion fracture of the attachment site of anteromedial bundle of the anterior cruciate ligament associated with injuries of lateral and medial collateral ligament and fibular fracture. We speculate varus stress in a flexed knee coupled with rotation between the femur and tibia caused this type of injury.     

胫骨平台外侧缘撕脱骨折的特点及临床诊治分析

目的 :探讨膝关节损伤中胫骨平台外侧缘撕脱骨折的特点及临床诊治。方法 :自2011年1月至2015年12月运用关节镜技术微创治疗关节内损伤结合双锚钉内固定胫骨平台外侧缘撕脱骨折29例,男17例,女12例;年龄27~62岁,平均41岁。20例合并前交叉韧带断裂(包含前交叉韧带胫骨止点撕脱骨折),3例合并后交叉韧带断裂,1例同时合并前交叉韧带和后交叉韧带断裂,3例合并侧副韧带撕裂,2例合并胫骨平台骨折(内侧平台骨折和外侧平台骨折各1例)。术前均行X线、CT及MRI检查明确诊断,在受伤后5~14 d进行手术,平均7 d。采用Lysholm膝关节评分对膝关节术前、术后功能进行评价。结果:手术时间40~125 min,平均85 min;出血量10~30 ml,平均15 ml。术后所有患者获随访,时间12~18个月,平均14个月。Lysholm膝关节评分由术前的52.0±4.2明显提高至术后1年的91.9±1.4(t=-49.24,P0.05)。抽屉试验、Lachman试验及侧方应力试验均阴性,骨折均骨性愈合。结论 :胫骨平台外侧缘撕脱骨折提示合并有膝关节静力稳定结构(关节韧带、关节囊、半月板等)的损伤,甚至关节内骨折。常规要行CT和MRI检查,建议行关节镜探查,防止漏诊,以使患者能得到及时、全面的治疗,为膝关节功能最大限度恢复创造有利条件。     

Schatzker Ⅳ型胫骨平台骨折的分型及治疗

目的　探讨SchatzkerⅣ型胫骨平台骨折的损伤特点、疗效差的原因和改进的方法。方法　根据SchatzkerⅣ型胫骨平台骨折的骨折特点 ,将 1993～ 2 0 0 2年间诊治的 5 1例患者分为劈裂型、整髁型和塌陷型。对劈裂型和整髁型骨折 ,无关节面塌陷者 ,采用内侧切口 ;CT检查示有关节面塌陷者 ,采用正中切口纠正塌陷并植骨 ;劈裂型支撑钢板在内后侧固定 ,整髁型支撑钢板在内侧固定 ,或双侧支撑钢板固定。对塌陷型骨折 ,采用内侧切口 ,行复位、植骨、支撑钢板内侧固定。 33例患者术后平均随访 4 1个月 ,对影响骨折预后的因素进行分析。结果　随诊的 33例患者膝关节活动度为30°～ 14 7°(平均 110°) ;Lysholm评分平均为 83 2分 ,优 8例、良 9例、中 14例、差 2例。平台非解剖复位、平台增宽 >4mm、平台向外侧移位 >8mm是预后较差的相关因素 (χ2 值分别为 5 10、6 0 8、8 0 2 ,P<0 0 5、<0 0 5、<0 0 1) ,也易导致骨性关节炎的发生。结论　应根据分型和CT检查结果选择手术入路和固定方法 ,膝内翻畸形、平台增宽 >4mm或向外侧移位 >8mm是影响预后的因素。     

经内侧副韧带的后内侧入路对Schatzker Ⅳ、Ⅴ、Ⅵ型胫骨平台骨折膝关节功能的影响

目的通过回顾性分析西安交通大学附属红会医院骨创伤医院经内侧副韧带的后内侧入路(或)联合前外侧入路治疗Schatzker Ⅳ、Ⅴ、Ⅵ型胫骨平台骨折患者的疗效,研究经内侧副韧带的后内侧入路治疗Schatzker Ⅳ、Ⅴ、Ⅵ型胫骨平台骨折对膝关节稳定性的影响。方法纳入2010年1月-2014年3月 Schatzer Ⅳ、Ⅴ、Ⅵ型胫骨平台骨折患者87例,其中男58例,女29例,年龄22~63岁,平均(43.6±3.2)岁;采用 Schatzker 胫骨平台骨折分型,其中Ⅳ型16例,Ⅴ型43例,Ⅵ型28例。手术入路采用经内侧副韧带的后内侧入路或联合前外侧入路。采用SPSS 19.0进行统计学分析。计量资料使用( x-± s)表示,3组间比较使用单因素方差分析方法和均数多重比较方法(LSD)。 P<0.05为差异有统计学意义。结果术后患者门诊随访,术后1、2、3、6、9、12个月门诊行膝关节正侧位X线片复查并随访,之后每年复查随访,随访时间10~48个月,平均(22.3±2.6)个月,末次随访时按照美国特种外科医院膝关节功能评分法评定疗效：优58例,良16例,中11例,差2例,优良率为85.05%。16例 Schatzker Ⅳ型患者末次随访平均 HSS 评分(87.87±10.55)分,43例SchatzkerⅤ型患者末次随访平均HSS评分(87.23±10.79)分,28例Schatzker Ⅵ型患者末次随访平均HSS评分(86.17±9.89)分。三组间患者末次随访HSS评分差异无统计学意义(F=0.153,P=0.859),且组间比较差异无统计学意义(Ⅵ、Ⅴ组间P=0.835,Ⅴ、Ⅵ组间P=0.680,Ⅳ、Ⅵ组间P=0.606)。末次随访时87例患者的膝关节活动度为100°~128°,平均115.5°,无屈曲挛缩畸形。本组患者无神经及血管损伤、感染、内固定物松动或断裂等并发症发生。结论经内侧副韧带的后内侧入路对于治疗Schatzker Ⅳ、Ⅴ、Ⅵ型胫骨平台骨折可达到充分显露,良好复位,有效固定的目的,且术后患者膝关节功能良好,该入路对膝关节稳定性未造成明显影响。     

前交叉韧带损伤与胫骨平台后侧骨损伤的相关性分析

目的探讨前交叉韧带(anterior cruciate ligament,ACL)损伤与胫骨平台后侧骨损伤的相关性。方法纳入我院2010年10月至2017年10月行膝关节MRI的门诊或住院病人581例,年龄为(45.72±11.38)岁(20~79岁);男362例,女219例。分析所有病人的膝关节MRI影像学资料,记录病人ACL损伤程度(轻度损伤/断裂/撕脱骨折)、胫骨平台后侧骨损伤程度(骨挫伤/骨折),以及股骨损伤、半月板和侧副韧带损伤情况,并分析其致伤原因。采用Spearman秩相关分析病人ACL损伤与胫骨平台骨损伤之间的关系,并分析可能的损伤机制。结果581例病人中,ACL轻度损伤440例(75.73%),ACL断裂122例(21.00%),ACL撕脱骨折19例(3.27%)。202例出现胫骨平台后侧骨挫伤,47例出现胫骨平台后侧骨折;152例(61.04%)发生在外侧平台,59例(23.69%)发生在内侧平台,38例(15.26%)发生在双侧平台。Spearman秩相关分析结果显示ACL损伤程度与胫骨平台后侧骨损伤程度呈正相关(r=0.344,P<0.0001)。结论随着ACL损伤程度增加,胫骨平台后侧骨损伤越重,且以胫骨平台后外侧骨损伤为主。     

外侧胫骨平台骨折合并软组织伤的关节镜诊治

目的探讨膝关节镜在外侧胫骨平台骨折伴随软组织损伤中的诊治作用,统计各种软组织损伤的发生率。方法自2007年3月至2012年4月采用关节镜辅助内固定术治疗外侧胫骨平台骨折38例。使用膝关节镜仔细探查合并的软组织损伤,根据不同损伤类型做出相应处理,并统计各类软组织损伤的发生率。结果在本组38例患者中,合并软组织损伤24例（63．2％）,其中复合软组织损伤7例（18．4％）。半月板损伤为最常见的软组织损伤,共18例（47．4％）．前交叉韧带损伤7例16例（18．4％）,后交叉韧带损伤1例（2．6％）,外侧副韧带2例（5．3％）,内侧副韧带损伤3例（7．9％）,腓总神经损伤2例（5．3％）。结论外侧胫骨平台骨折常伴随不同类型的软组织损伤,使用膝关节镜检查可以对各类伴随的软组织损伤作出正确诊断,并及时采取针对性的治疗。     

Early arthroscopy in diagnosis and treatment of acute injury of the knee]

Twelve patients with swelling and functional embarrassment of the knee joint caused by a traffic accident were radiographically found to have tibial plateau fractures (7 patients), posterior dislocation (1), fracture of anterior tibial spine (1), single fracture of the posterior tibial spine (1), anterior dislocation (1), and negative findings (1). Arthroscopy was performed 2 to 10 days after trauma, revealed associated injuries not shown on X-ray films in every knee including rupture of cruciate ligaments (ACL 8, PCL 1), tear of menisci (lateral one 8; medial one 2), and disruption of collateral ligaments (medial one 3; lateral 1). These injuries were promptly treated accordingly either through the scope or by open operation. Beside, inadequately reduced bone fragments, viewed through the scope, were further corrected incidentally and conveniently. We believe that early arthroscopy for acute knee injury is a real necessity in perfecting diagnosis and improving treatment.     

Magnetic resonance imaging in the evaluation of tibial eminence fractures in adults

Proton density and T2-weighted sagittal, axial, coronal, and inversion recovery fat suppression magnetic resonance imaging (MRI) sequences were reviewed in 21 adults (10 men and 11 women) with 22 tibial eminence fractures. Average patient age was 43 years (range: 19-62 years). There were 3 type I, 3 type II, 12 type III, and 4 type IV fractures. The average fracture fragment size was 21 x 23 mm, and the average displacement was 5.5 mm (range: 0-12 mm). The MRI disclosed anterior cruciate ligament (ACL) insertional avulsions in 20 (91%), distal posterior cruciate ligament (PCL) avulsions in 4 (18%), intrasubstance ACL damage in 9 (41%), intrasubstance PCL injury in 3 (14%), medial collateral ligament (MCL) tears in 9 (41%) knees, retinacular injury in 8 (36%), posterolateral corner damage in 8 (36%), medial meniscal tears in 5 (23%), and 4 (18%) had lateral meniscal tears. Occult subchondral osseous injuries were seen in the posterolateral tibial plateau in 13 (59%) knees, anterolateral femoral condyle in 4 (18%), and posteromedial tibial plateau in 5 (23%) knees. Discrete osteochondral fractures were present in 7 (32%) knees. Significant osseous, cartilaginous, meniscal, and ligamentous damage was discovered in all patients. Based on these findings, we recommend MRI evaluation of all tibial eminence fractures to accurately detect all knee damage.     

A case of fracture of posterior margin of lateral tibial plateau by pivot shift mechanism in chronic ACL insufficiency

We present a case of the fracture of the posterior margin of the lateral tibial plateau, probably by pivot shift mechanism in a chronic anterior cruciate ligament (ACL) insufficient knee. Multitudes of direct and indirect signs of ACL injury were evident on MRI, including anterior translation of the lateral tibial plateau, buckling of the posterior cruciate ligament, deep sulcus sign, and the fracture of the posterior aspect of lateral tibial plateau. With careful interpretation of the history and arthroscopic findings, the main insult of the current case was identified as the fracture of the posterior margin of the lateral tibial plateau with antecedent chronic ACL insufficiency, rather than as the acute or subacute ACL rupture. This type of injury is worth due attention as a late complication of chronic ACL insufficiency, and the clinicians should be careful in constructing the clinical scenario for the temporal relationship of injury. To the best of our knowledge, this type of injury as a late complication of chronic ACL insufficiency has never been reported in the literature.     

Osteonecrosis of the medial tibial plateau: a case report

Medial tibial plateau osteonecrosis is a disease that lacks distinguishing signs and symptoms, especially in the early stage, and requires clinicians to exercise a high degree of suspicion to prevent disease progression. We present a case of spontaneous osteonecrosis of the medial tibial plateau in a 59-year-old woman. Within 5 months of the onset of symptoms, the entire medial tibial plateau collapsed down into the metaphyseal region, causing severe varus deformity, instability, and inability to walk without crutches and a hinged knee brace. Initial symptoms of medial joint line pain and generalised swelling of the knee were attributed to early degenerative changes. Subsequent radiographs were misinterpreted as simple medial compartment arthritis. Due to severe bone loss and significant lateral collateral ligament attenuation, a total joint arthroplasty was required, using a stemmed tibial component with medial metal block and bone graft augmentation. The speed of bone collapse and the extension into the metaphysis, requiring complex joint arthroplasty, makes this case unique.     

Analysis of medial tibial plateau fracture injury patterns using quantitative 3D measurements

BackgroundThe Wahlquist system classifies tibial medial plateau fractures into three types based on the sagittal fracture line location, with type C at highest risk of complications. However, the injury mechanism of tibial medial plateau fractures, especially tibial rotation movement, remains unclear. The purpose of the present study was to determine the injury patterns of medial tibial plateau fractures using 3D model simulation and quantitative 3D measurements.MethodsSeventy-eight consecutive AO/OTA type 41-B tibial plateau fractures were retrospectively analyzed using CT-based 3D models and quantitative 3D measurements. The knee posture at the moment of fracture occurrence was simulated, and various knee angles in the sagittal, coronal, and axial planes were measured to evaluate the mechanism of medial tibial plateau fracture. The mean valgus-varus, hyperextension-flexion, and internal-external rotation angles were determined, and the chi-square test was used for comparisons of categorical varus and valgus force data to determine the main force direction in Wahlquist type C fractures.ResultsAngle measurements in the coronal planes showed that 28 (35.9%) medial tibial plateau fractures resulted from a varus injury pattern, while 50 fractures (64.1%) resulted from a valgus pattern. Valgus force produced significantly more Wahlquist type C fractures (37 of 50 fractures) than varus force (2 of 28 fractures) (p < 0.05). There was no significant difference in the cases of patients with type C fractures between the tibial internal and external rotation injury patterns(P > 0.05).ConclusionsValgus force was the cause of 64.1% of the medial tibia plateau fractures in the present cohort. Furthermore, valgus force produced more Wahlquist type C fractures than varus force. The present findings will help orthopedists understand the injury mechanism of the Wahlquist classification system, and will facilitate the identification of the common features of medial tibial plateau fractures induced by specific injury patterns.     

Proximal avulsion of five ligaments and revised diagonal principle in tibial plateau fractures

PurposeThe aim of the study was to analyze the incidence of proximal avulsion of the five main ligaments and to revise the diagonal tension/compression concept in tibial plateau fractures.MethodsComputed tomographic images of 1263 cases of tibial plateau fractures were retrospectively analyzed by the OTA/AO classification and four-column nine-segment classification. The correlation between proximal avulsion of five ligaments and the injury mechanism was analyzed.ResultsIn total, 1263 tibial plateau fractures in 1253 patients were included. A total of 92 cases (7.3%) associated with proximal avulsions were identified among the 1263 tibial plateau fracture cases obtained from our institution's database. The 92 avulsions occurred in 82 patients, among whom 10 patients had two different avulsions in a single knee. The incidence of proximal avulsion fracture of the medial and lateral collateral ligament was 3.6% (45/1263) and 2.1% (26/1263), respectively. The incidence of avulsion of the anterior cruciate ligament and avulsion of the posterior cruciate ligament was much lower at 0.2% (2/1263) and 0.1% (1/1263), respectively. Proximal avulsion of the patellar ligament occurred in 18 cases (incidence rate = 1.4%). Several combinations of injuries, composed of distal tibial plateau fractures and proximal avulsion of ligaments, were identified.ConclusionsAmong the patients with tibial plateau fracture, the incidence of proximal avulsion of the five ligaments was 7.3% (92/1263). The four-column and nine-segment classification is an exhaustive method for recording injuries in these ligaments. The revised diagonal injury concept is useful for understanding the injury mechanism and choosing the appropriate surgical strategy.     

The incidence of soft tissue injury in operative tibial plateau fractures: a magnetic resonance imaging analysis of 103 patients

OBJECTIVES: The goal of this study was to determine the incidence of injury to soft tissue structures of the knee in tibial plateau fractures scheduled for surgery. DESIGN: Prospective cohort. SETTING: Level I academic medical center. PATIENTS/PARTICIPANTS: One hundred three consecutive patients with acute tibial plateau fractures indicated for operative intervention. INTERVENTION: Standard x-ray examinations, including anteroposterior, lateral, and oblique views, were performed in the emergency department. Subsequently all patients had magnetic resonance imaging performed. The Schatzker and AO/OTA classifications were used to classify each fracture pattern based solely on the x-rays. Soft tissue injuries were assessed by magnetic resonance imaging. MAIN OUTCOME MEASUREMENTS: Fifteen categories of injury were determined as positive or negative on each magnetic resonance imaging, which included tears of the cruciates, collateral ligaments, menisci, and posterolateral corner. RESULTS: The overall incidence of injury to soft tissues was higher than previously reported. Only 1 patient (1%) in the series had complete absence of any soft tissue injury. Seventy-nine patients (77%) sustained a complete tear or avulsion of 1 or more cruciate or collateral ligaments. Ninety-four patients (91%) had evidence of lateral meniscus pathology. Forty-five patients (44%) had medial meniscus tears. Seventy patients (68%) had tears of 1 or more of the posterolateral corner structures of the knee. The most frequent fracture pattern was a lateral plateau split-depression (Schatzker II) (60%). No pure depression injuries (Schatzker III, AO/OTA 41-B2) were seen. CONCLUSIONS: The incidence of complete ligamentous or meniscal disruption associated with operative tibial plateau fractures was higher than previously reported. Though the clinical importance of injury to each of these structures is unknown, the treating surgeon should be aware that a variety of soft tissue injuries are common in these fractures. In addition, all fractures had at least 1 cortical split visible on magnetic resonance imaging, implying that pure depression patterns are very rare or may not exist.     

A case of extensive heterotopic ossification following multiple ligament reconstruction after severe knee trauma

We present a case of extensive heterotopic ossification (HO) around the knee joint following multiple ligament reconstruction after severe trauma. A 50-year-old female sustained a motor vehicle accident and underwent multiple trauma. The initial diagnosis of the knee included avulsion fracture of the tibial attachment of the posterior cruciate ligament, multiple ligament injury including the anterior cruciate ligament and medial collateral ligament, medial and lateral meniscal tears, and the fracture of the inferior pole of the patella. The surgical treatment was delivered in 2 stages including reconstructions of the anterior and posterior cruciate ligaments reconstruction, and repair of the medial collateral ligament and menisci. At postoperative 2 months, HO was observed around the knee joint, especially on the medial and posterior aspect, and proceeded gradually. At postoperative 1 year, the ossification appears matured with clear trabeculation and round margin. The motion arc was fairly preserved from 20° to 70°. Considering the benefits and risks of the further operative management, the patient opted for conservative management. The etiology of HO is not thoroughly known, and its therapy is empiric. Although prevention is not always possible, feasible preventive measure should be exerted to avoid the irreversible pathology. This unique sequelae should be kept in mind of orthopedic surgeon to devise pertinent management plan and deliver it to the injured.     

Ligaments of the knee

The ligaments of the knee can be divided into four groups. Ventral reinforcements are the patellar retinaculae. The posteromedial complex stabilizes the valgus stress. It consists of the medial collateral ligament, the thickened posteromedial capsule and a branch of the tendon of the semimembranosus muscle as well as the oblique popliteal ligament. On the lateral side the posterolateral complex protects the knee against varus stress. Here the lateral collateral ligament, the tendon of the popliteus muscle and the so-called popliteofibular fibres work together. The cruciate ligaments control the contact between femoral condyles and tibial plateau during flexion-extension of the knee. They course between the two layers of the capsule, the membranous and the synovial layer.