Isolated osteochondral fracture of the patella without patellar dislocation

Chondral fractures of the patella are associated with acute dislocation of the patella. Osteochondral fracture in patellar dislocation is located in the medial facet of the patella. This article presents a case of a 15-year-old female ballerina with isolated displaced osteochondral fracture of the patella without patellar dislocation. She had no history of trauma. A Merchant's view of both knees showed mild subluxation of the patella, a small fragment on the lateral aspect of the knee, and a small defect of the centromedial patella. Axial magnetic resonance imaging (MRI) revealed an osteochondral fragment measuring 13 mm medial to the patella. However, the medial patellofemoral ligament and medial retinaculum were intact. An effusion on the medial side of the patella consistent with hemarthrosis was observed. An absence of a contusion or bone bruise on the lateral femoral condyle was shown. The loose body was removed arthroscopically. Intraoperative findings included a 1.5×2 cm osteochondral fragment. It is unusual that the osteochondral patellar defect site in this patient was in the inferior and central areas of the patella. Patellar chondral fractures without dislocation or patella fracture are rare. Therefore, the possibility of a trivial trauma leading to an osteochondral fracture should be kept in mind in adolescent and young adults who present with knee pain and hemarthrosis.     

Why do orthopaedic surgeons ignore the medial patellofemoral ligament?

The medial patellofemoral ligament (MPFL) is a condensation of the medial capsule of the knee joint. In the past two decades dissection studies have shown that it extends from the superomedial border of the patella to the femoral epicondyle, at or immediately above the adductor tubercle. MRI and operative studies have revealed that it is almost invariably damaged by lateral patellofemoral dislocation. Current surgical management of such dislocations may involve imbricating the torn medial capsule and parapatellar retinaculum back onto the medial border of the patella. If the medial patellofemoral ligament is torn at or near the femoral attachment, as the latest MRI and operative studies demonstrate it frequently is, then this medial reefing procedure will not be successful in restoring normal anatomy and function. Here we review the anatomy and function of the MPFL, its role in patellar dislocation and as well as surgical treatment for patellar dislocation.     

Classification of lesions of the medial patello-femoral ligament in patellar dislocation

The remnants of the medial patello-femoral ligament (MPFL) of 67 knees, 18 with acute patellar dislocation and 49 with chronic patellar dislocation, were studied. The MPFL injuries of the acute cases were categorised into 2 groups: an avulsion tear type and a substantial tear type. The chronic cases were put into 3 groups: those with loose femoral attachment (9 knees), those with scar tissue formation or abnormal scar branch formation (29 knees), and those with no evidence or continuity of the ligament (absent type) (11 knees). It is concluded that incompetence of the medial patello-femoral ligament is a major factor in the occurrence of recurrent patellar dislocation and/or an unstable patella following an acute patellar dislocation.     

急性髌骨脱位的关节镜下诊断与治疗

目的 探讨急性髌骨脱位的关节镜下表现,评价关节镜下治疗方法对其的疗效.方法 2001年2月至2003年12月,共收治急性髌骨脱位16例17膝,女12例,男4例,1例女性患者为双侧发病.年龄14～31岁,平均21.9岁.从发生髌骨脱位到手术的时间间隔为3～25 d,平均13.6 d.术前对所有患者进行放射学检查,观察髌骨的形态和位置、股骨滑车角、髌骨外侧半脱位和下肢对线的状况.临床测量Q角和全身关节松弛度.全部手术均在关节镜监视下施行.首先引流关节内血肿,而后进行全面的关节内探查,取出游离的软骨和骨软骨碎片,施行软骨成形术,修整损伤的软骨面,最后松解外侧支持带以及紧缩缝合内侧支持带.结果 关节镜下表现包括关节内血肿,股骨外侧髁和髌骨内侧骨软骨损伤,游离体形成以及内侧支持结构撕裂.所有病例均获得随访,随访时间1.5～3.5年,平均2.1年,均未发生感染等严重并发症,也无关节内大量血肿和髌骨缺血性坏死发生.全部病例膝关节活动度恢复正常,恢复至术前的活动水平,未发生再脱位.5例患者术后早期主诉髌骨内侧存在牵拉感和弹响.所有病例均未出现重度髌股关节退行性改变.结论 关节镜手术是诊断和治疗急性髌骨脱位的优良方法,操作简便,疗效可靠.     

Transverse divergent dislocation of the elbow with ipsilateral distal radius fracture in a child

We report a rare case of an irreducible transverse divergent dislocation of the elbow with an ipsilateral distal radius torus fracture and a fracture of the coronoid process in a 9-year-old male. Closed reduction of the elbow was attempted, but the humeroulnar joint remained dislocated. At surgery, the avulsed anterior band of the medial collateral ligament complex of the elbow was found to be interposed between the medial condyle of the humerus and the olecranon. The dislocation was reduced after relieving the ligament entrapment, which was then repaired. The unstable proximal radioulnar joint was fixed with a Kirschner wire. Two years after surgery, the patient had a painless left elbow with full range of motion and no instability. He was able to use his upper extremity for all activities in his daily life and had returned to sports. No radiographic abnormalities were found at this follow-up, particularly premature epiphyseal closure of the radial head. Closed reduction has been successful in a majority of reported cases of transverse divergent dislocation of the elbow, yet the presence of an incomplete reduction of the ulnohumeral joint should alert the physician to the possible interposition of soft tissues or bony fragments necessitating an open reduction.     

Die Rekonstruktion des medialen patellofemoralen Ligaments mit der getunnelten Semitendinosussehne

OBJECTIVE: Stabilization of the patella by reconstruction of the medial patellofemoral ligament. INDICATIONS: Chronic recurrent lateral dislocation or subluxation of the patella. Habitual lateral dislocation of the patella. CONTRAINDICATIONS: Primary dislocation of the patella. Genu valgum with a Q-angle > 15 degrees . Status following semitendinosus tendon transfer to reconstruct the anterior cruciate ligament. Joint infection. Neurogenic instability, ischiocrural muscle deficiency. SURGICAL TECHNIQUE: Division of the distal insertion of the semitendinosus muscle at the pes anserinus. Subligamentous tunneling at the proximal insertion of the medial collateral ligament. The distal end of the semitendinosus tendon is transferred through the subligamentous tunnel to the medial patellar margin. Fixation of the tendon to the medioproximal patellar margin by passing it through an oblique transpatellar drill hole. RESULTS: The patella was stabilized by dynamic reconstruction of the medial patellofemoral ligament in 14 patients with chronic recurrent or habitual lateral patellar dislocation. Ten patients were available for clinical follow-up assessment at an average of 13 months (8-27 months) postoperatively. The postoperative Kujala Index (maximum 100 points) increased on average from 56 to 95 points.     

关节镜下自体腘绳肌腱重建内侧髌股韧带治疗复发性髌骨脱位

目的探讨关节镜下采用自体腘绳肌腱重建内侧髌股韧带治疗复发性髌骨脱位的疗效。方法 2005年1月-2010年1月,对22例(22膝)复发性髌骨脱位患者采用关节镜下外侧支持带松解,取自体腘绳肌腱重建内侧髌股韧带治疗。男5例,女17例;年龄15～19岁,平均17.3岁。髌骨脱位3～8次,平均4次。主要临床症状为患膝关节疼痛、肿胀、无力,活动受限。髌骨倾斜试验、恐惧试验、内侧髌股韧带止点处压痛、髌骨向外推移时恐惧征均呈阳性。根据国际膝关节文献委员会(IKDC)评分标准,膝关节功能主观评分为(36.7±4.7)分,Lysholm评分为(69.3±3.8)分。X线片示患者髌骨向外倾斜。结果术后切口均Ⅰ期愈合。患者均获随访,随访时间18～49个月,平均34个月。术后患者关节疼痛、肿胀、无力等症状较术前明显改善。随访期间患者髌骨脱位无复发。末次随访时,IKDC膝关节功能主观评分为(92.4±5.3)分,Lysholm评分为(91.7±5.2)分,与术前比较差异均有统计学意义(P<0.05)。结论关节镜下取自体腘绳肌腱重建内侧髌股韧带可明显改善髌骨稳定性,是治疗复发性髌骨脱位的有效方法之一。     

改良髌骨双骨道法自体股薄肌腱重建髌骨内侧支持带治疗复发性髌骨脱位

目的探讨改良髌骨双骨道法自体股薄肌腱重建髌骨内侧支持带（medial patellofemoral ligament,MPFL）治疗复发性髌骨脱位的临床效果,同时探讨解剖高危因素对术后效果的影响。方法2007年1月-2010年2月,对36例髌骨复发性脱位（单侧31例,双侧5例）采用改良髌骨双骨道法自体股薄肌腱重建MPFL,在髌骨内上缘由后内向前外向髌骨内1／2表面平行钻2个3．5mm骨道,将股薄肌腱引过骨道,将股薄肌腱的两游离端拉入股骨内侧骨道,屈膝30。位可吸收螺钉固定。对所有患者的Beighton评分,Q角,Insall指数,滑车发育不良分级,胫骨结节一滑车沟距离（TT—TG）等进行测量。临床评分采用Kujala,Lysholm和Tegner评分,同时调查患者的满意度。结果32例对手术的效果非常满意,3例满意,1例不满意。Kujala、Lysholm、Tegner评分分别由术前（64．34-15．0）、（65．1±18．6）、（3．2±1．1）分显著提高到术后（92．4±9．2）分（t=4．657,P=0．002）,（92．0±10．1）分（t=3．936,P=0．006）和（5．2±1．0）分（t=6．633,P=0．001）。80．6％（29／36）的患者在术后6—8个月恢复到受伤前的运动水平。1例术后1年再次髌骨脱位。97．6％（40／41）的膝关节存在股骨滑车发育不良,Beighton评分（5．2±2．5）分,Insall指数为1．22±0．14,Q角（13．6±3．9）°,TT-TG值（13．7±4．4）mm,与功能评分无相关性（P〉0．05）。结论自体股薄肌腱改良髌骨双骨道法重建MPFL是一种可靠安全经济的手术方法。高危解剖因素如高位髌骨、滑车发育不良、关节松弛等情况广泛存在于髌骨复发性脱位的患者中,虽未发现其严重程度会直接影响手术效果,但当复合因素存在时,仅重建MPFL的软组织手术可能不足以完全防止髌骨脱位复发。     

Operative strategy in postero-medial fracture-dislocation of the proximal tibia

Objective

In 1981, Moore introduced a new classification for dislocation-type fractures caused by high-energy mechanisms. The most common medial Moore-type fractures are entire condyle fractures with the avulsion of the median eminence (tibial anterior cruciate ligament (ACL) insertion). They are usually associated with a posterolateral depression of the tibial plateau and an injury of the lateral menisco-tibial capsule. This uniform injury of the knee is increasingly observed in the recent years after skiing injuries due to the high-speed carving technique. This uprising technique uses shorter skis with more sidecut allowing much higher curve speeds and increases the forces on the knee joint.The aim of this study was to describe the injury pattern, our developed operative approach for reconstruction and outcome.

Methods

A total of 28 patients with 29 postero-medial fracture dislocation of the proximal tibia from 2001 until 2009 were analysed. Clinical and radiological follow-up was performed after 4 years on average (1 year in minimum). Evaluation criteria included the Lysholm score for everyday knee function and the Tegner score evaluating the activity level. All fractures were stabilised post primarily. The surgical main approach was medial. First, the exposure of the entire medial condyle fracture was performed following the fracture line to the articular border. The posterolateral impaction was addressed directly through the main fracture gap from anteromedial to posterolateral. Small plateau fragments were removed, larger fragments reduced and preliminarily fixed with separate K-wire(s). The postero-medial part of the condyle was then prepared for main reduction and application of a buttress T-plate in a postero-medial position, preserving the pes anserinus and medial collateral ligament. In addition, a parapatellar medial mini-arthrotomy through the same main medial approach was performed. Through this mini-arthrotomy, the avulsed anterior eminence with attached distal ACL is retained by a transosseous suture back to the tibia.

Results

We could evaluate 26 patients (93%); two patients were lost to follow-up due to foreign residence. Median age was 51 years (20–77 years). The fractures were treated post primarily at an average of 4 days; in 18 cases a two-staged procedure with initial knee-spanning external fixator was used. All fractures healed without secondary displacement or infection. As many as 25 patients showed none to moderate osteoarthritis after a median of 4 years. One patient showed a severe osteoarthritis after 8 years. All patients judge the clinical result as good to excellent. The Lysholm score reached 95 (75–100) of maximal 100 points and the Tegner activity score 5 (3–7) of maximal 10 points (competitive sports). The patients achieved a median flexion of 135° (100–145°).

Conclusion

In our view, it is crucial to recognise the different components of the injury in the typical postero-medial fracture dislocation of the proximal tibia. The described larger medial approach for this type of medial fracture dislocation allows repairing most of the injured aspects of the tibial head, namely the medial condyle with postero-medial buttressing, the distal insertion of the ACL and the posterolateral impaction of the plateau.     

关节镜辅助下小切口重建内侧髌股韧带治疗创伤性复发性髌骨脱位

目的探讨关节镜辅助下小切口同种异体肌腱重建内侧髌股韧带(MPFL)治疗创伤性复发性髌骨脱位的临床效果。方法回顾性分析自2006年1月～2010年4月共收治28例创伤性复发性髌骨脱位,所有患者在第一次脱位均为膝关节外伤所致,伤后患膝明显肿胀及髌骨脱位-复位感,此后出现髌骨脱位3次以上者。手术方法:先行关节镜检查,髌骨外侧支持带紧张者行松解术,关节镜监视下调整MFPL的张力并于其解剖止点以同种异体肌腱重建MFPL,术后接受正规功能康复锻炼。结果术后平均随访26个月(12～36个月)。重建术后无髌骨再次脱位发生,髌股关节稳定。术前、术后均采用Lysholm和Kujala膝关节评分标准,手术前后评分差异有统计学意义(P<0.05)。结论选择适当的病例,重建内侧髌股韧带是治疗创伤性复发性髌骨脱位的有效方法。