Ultrastructural study of the extra-articular Leeds-Keio ligament prosthesis

BACKGROUND: There have been several histological studies of the Leeds-Keio ligament in anterior cruciate ligament reconstruction, but there have been few of the Leeds-Keio ligament in the extra-articular portion. AIMS/METHODS: To report the histological and ultrastructural findings of two cases of medial patellofemoral ligament reconstruction using the Leeds-Keio ligament, removed 6.1 years and 8.7 years after implantation. RESULTS: In both cases, the tissue over the Leeds-Keio ligament was a ligament-like tissue. Electron microscopy showed that the diameter of the collagen fibrils in the tissue over the Leeds-Keio ligament was unimodal in the case investigated 6.1 years after implantation but bimodal in the case investigated after 8.7 years. CONCLUSIONS: The tissue over the Leeds-Keio ligament may continue to grow with prolonged periods of mechanical stress.     

Patella fracture after medial patellofemoral ligament reconstruction using suture anchors

The medial patellofemoral ligament (MPFL) acts as a soft tissue restraint to lateral subluxation of the patella, and is frequently damaged following patellar dislocation. A number of techniques for repair or reconstructions of the MPFL have been reported. We report two cases of patellar fracture following MPFL reconstruction utilizing suture anchors and bone tunnels that do not completely traverse the patella. The first case occurred seven months after surgery and the second case was at six weeks following surgery. There have been previous reports of patellar fracture following MPFL reconstruction, particularly when patellar tunnels completely traverse the patella. The authors decided to use suture anchors to reduce the risk of patellar fracture, and they feel that the fractures reported in this paper resulted from surgical error rather than system error. We feel that this is an important learning point when initially using this technique, and should be disseminated to other surgeons who undertake this surgery.     

Anatomy and biomechanics of the medial patellofemoral ligament

The medial patellofemoral ligament (MPFL) is a band of retinacular tissue connecting the femoral medial epicondyle to the medial edge of the patella. The MPFL is approximately 55 mm long, and its width has been reported to range from 3 to 30 mm. The MPFL is overlaid by the distal part of vastus medialis obliquus to a variable extent, and fibres of MPFL merge into the deep aspect of the muscle. Despite the MPFL being very thin, it had a mean tensile strength of 208 N, and has been reported to be the primary passive restraint to patellar lateral displacement. Lateral patellar displacement tests in vitro showed that the patella subluxed most easily at 20 degrees knee flexion. The contribution of the MPFL to resisting patellar lateral subluxation was greatest in the extended knee. This finding was linked to the retinaculae being tightest in full knee extension, and slackening with flexion.     

The anatomy and reconstruction of the medial patellofemoral ligament

INTRODUCTION: Reconstruction of the MPFL for recurrent and acute lateral dislocation of the patella is becoming more accepted. This study aimed to further define the medial patellofemoral ligament (MPFL) anatomy and to describe the most suitable sites for graft attachment when reconstructing the MPFL. MATERIALS AND METHODS: Anatomical dissection was performed on 25 embalmed knee specimens. Four separate specimens were used to assess graft fixation points. Sites were tested for isometricity from 0 to 120 degrees of knee flexion. Length patterns were considered isometric if there was less than 5 mm of length change throughout range of motion. RESULTS: The MPFL attaches from the posterior part of the medial epicondyle, to the superomedial patella, the under-surface of vastus medialis, and the quadriceps tendon. Optimal attachment points for an MPFL graft were the superior patella and the femoral attachment points of the MPFL (just distal to the adductor tubercle) and points posterior and inferior to this. CONCLUSION: We have defined the anatomy and kinematics of the MPFL with reconstruction of this ligament in mind.     

A new technique for reconstructing the medial patellofemoral ligament

Many surgical techniques exist for treating patella instability. Over recent years, attention has focussed on reconstruction of the medial patellofemoral ligament (MPFL). We report a procedure involving a lateral release, distal realignment of the tibial tubercle and anatomic reconstruction of the MPFL using a graft composed of a redundant strip of medial retinacular tissue. Nineteen patients (twenty-one knees) with chronic patellofemoral instability who had failed conservative treatment underwent this procedure and were assessed clinically and radiologically at an average of 23 months post-operation. No patients were lost to follow-up. There was no recurrence of subluxation or dislocation. All achieved levels of activity comparable to or improved compared to pre-operative uninjured levels. This combined procedure incorporating a previously un-described method of reconstructing the MPFL gives superior results compared to previous studies. No graft donor site morbidity occurred and patient outcome scores, especially objective stability of the patella to lateral shift, were excellent.     

A mid-term follow-up of medial patellofemoral ligament reconstruction using an artificial ligament for recurrent patellar dislocation

A prospective study on medial patellofemoral ligament reconstruction for recurrent patellar dislocation was performed. At an average follow-up of 5.9 years, 27 MPFL reconstructions using a mesh-type artificial ligament and medial retinaculum slip coverage were reviewed using the Crosby and Insall grading system. Fifteen knees (55%) were classified as excellent, 11 knees (41%) as good, 1 knee (4%) as fair/poor and none as worse. At a mid-term follow-up, medial patellofemoral ligament reconstruction should be considered as a safe and effective operation.     

Clinical outcomes of medial patellofemoral ligament reconstruction using FiberTape and knotless SwiveLock anchors

BackgroundWe aimed to prospectively investigate the clinical outcomes of medial patellofemoral ligament (MPFL) reconstruction using polyester high-strength suture tape with knotless anchors.MethodForty-three patients (65 knees) were followed for at least 1 year postoperatively, with 27 patients (43 knees) followed for 2 years postoperatively. All patients underwent MPFL reconstruction using polyester high-strength suture tape (FiberTape®; Arthrex) with knotless anchors (SwiveLock®; Arthrex). Repeated dislocation and residual patellar apprehension signs were recorded, and congruence and tilting angles were measured. Changes in Knee Injury and Osteoarthritis Outcome Scale (KOOS) scores and their associations with the preoperative tibial tubercle–trochlear groove (TT-TG) distance were analyzed.ResultsNo repeat dislocations (0%) were observed. One (2.4%) residual positive patellar apprehension sign was noted. The mean tilting angle decreased from 24.8° to 10.7° (P < 0.001), and the mean congruence angle decreased from 24.9° to 4.3° (P < 0.001). At 2 years follow up, all KOOS subscales had improved: pain (92.0 ± 12.9), symptoms (90.2 ± 11.9), activities of daily living (95.7 ± 7.3), sports activity (85.7 ± 16.9), quality of life (87.7 ± 12.9), and patellofemoral (89.0 ± 9.6) outcomes. KOOS subscale scores improved regardless of the preoperative TT-TG distance (21.1 ± 3.5 mm; range, 13.8–29.9 mm).ConclusionsMPFL reconstruction using FiberTape and knotless SwiveLock anchors was performed without sacrificing autologous tissue. No recurrent patellar dislocation was observed during the 2-year follow up period. All KOOS subscale scores improved using FiberTape and SwiveLock anchors in MPFL reconstruction.     

内侧髌股韧带临床治疗的研究现状

内侧髌股韧带(MPFL)是髌股关节内侧的主要静力结构,对稳定髌股关节内侧,防止其外脱位起重要作用。临床上MPFL损伤,可引起膝痛、髌骨不稳定等。对急性创伤性髌骨脱位者,临床上可行保守治疗,但易复发,早期手术治疗近年为一些学者所提倡。本文对MPFL的解剖、损伤后的临床表现及治疗作一综述。     

大收肌腱转位重建内侧髌股韧带的应用解剖

目的 评估大收肌腱转位重建内侧髌股韧带治疗髌骨脱位的术式可行性及可能的风险,探讨转位肌腱固定方法。 方法 解剖观察30侧尸体标本的大收肌腱及内侧髌股韧带形态及其周围血管神经等毗邻关系;测量收肌结节至内侧髌股韧带股骨止点距离、收肌结节至大收肌腱移行部距离;并在尸体标本上模拟手术。 结果 大收肌腱长度（收肌结节至收肌裂孔距离）为（105±14）mm（77~129 mm）,内侧髌股韧带轴长长度为（46±6）mm（33~57 mm）,收肌结节至内侧髌股韧带股骨止点距离为（9±2）mm（6~13 mm）,收肌结节至大收肌腱移行部距离为（124±11）mm（102~144 mm）。 结论 长约55 mm的大收肌腱通过转位固定于髌骨内侧缘重建内侧髌股韧带可行,大收肌腱作为重建内侧髌股韧带的供体是一个良好的选择。     

Biomechanical tensile strength analysis for medial patellofemoral ligament reconstruction

Background

Medial patellofemoral ligament (MPFL) reconstruction is a surgery for acute and chronic dislocating patella. Several surgical techniques have been described. No biomechanical study has compared suture anchors, interference screws, and suspensory cortical fixation for MPFL reconstruction using human gracilis allograft.

膝关节内侧髌股韧带止点的解剖

目的 观察国人内侧髌股韧带止点的解剖学特点及其在髌骨稳定中的作用。 方法 采用30例成人尸体膝关节标本,观测国人内侧髌股韧带止点的解剖学特点。 结果 内侧髌股韧带在股骨端附着于收肌结节与股骨内上髁之间的骨脊上,此处纤维薄而窄,向前逐渐增宽增厚。在髌骨端,附着于髌骨内缘上2/3,此处最厚最宽。 结论 揭示了内侧髌股韧带止点的解剖学特点,为临床应用提供解剖学基础。     

同种异体韧带重建内侧髌股韧带术治疗复发性髌骨脱位

目的探讨同种异体韧带重建内侧髌股韧带(Medial patellofemoral ligament,MPFL)治疗复发性髌骨脱位(Recurrent dislocation of knee-cap,RDP)的疗效。方法采用同种异体韧带重建内侧髌股韧带治疗复发性髌骨脱位21例,男9例,女12例;平均年龄33.9岁,根据Lysholm膝关节功能评定表评估膝关节功能来评价疗效。结果术后随访6~24个月,平均随访9.7月,优良19例,可差2例,优良率90.4%。结论同种异体韧带重建内侧髌骨韧带治疗复发性髌骨脱位安全,可靠。     

Dual tunnel medial patellofemoral ligament reconstruction for patients with patellar dislocation using a semitendinosus tendon autograft

The purpose of this study was to describe a safer and more anatomical technique of MPFL reconstruction and to report the short-term results. The subjects included 20 patients with patellar dislocation with a mean age of 23. The operation was performed using a double-looped autogenous semitendinosus tendon graft. Two small bone tunnels were made at the medial edge of the patella, mimicking the wide patellar insertion of the MPFL and a bone tunnel was made at the femoral insertion site. The free ends of the graft attached to the patella and the loop end was fixed to the femoral side. Five patients were available for follow-up interviews by telephone and the remaining 15 were directly examined by physical examination and radiographic evaluation at 2 years or longer postoperatively. The average follow-up period was 30 months. Re-dislocation or patellar fracture was not seen in any patients. The average Kujala's score was 96 with a range from 84 to 100. Six patients were classified as excellent and 14 as good, according to the Crosby and Insall grading system. Radiographically, narrowing of the patellofemoral joint space was observed in 2 cases with previous osteochondral fracture out of those who were directly examined. The dual tunnel MPFL reconstruction produces favorable results in subjective and functional assessment of outcome without complications.     

The favourable anisometry: an original concept for medial patellofemoral ligament reconstruction

Medial patellofemoral ligament (MPFL) reconstruction for recurrent patellar dislocation has recently become more popular. We describe a technique that involves tensioning of the graft with the knee in full extension while simultaneously pulling with a bone hook on the patella in the direction of the quadriceps tendon, thus facilitating placement of the femoral attachment and accurate graft tensioning. We investigated the clinical outcome of this reconstructive procedure in 20 patients (23 knees), with a mean follow-up of 2 years. There was no recurrence of dislocation after surgery. At the 3 months follow up visit, nine knees had an extensor lag. At the last follow up visit, only one patient had an extensor lag. The mean Kujala score at the last follow-up was 93 (+/− 6) points. Severe primary chondral lesion had a negative influence on the final functional result. It is suggested that patella alta could increase the risk of post-operative extensor lag and quadriceps weakness as the tension tends to be more in the reconstructed MPFL than in the patellar tendon when the knee extends. In cases of severe patella alta we would suggest including distalisation of the tibial tubercle, with an MPFL reconstruction.     

The relationship between trochlear dysplasia and medial patellofemoral ligament rupture location after patellar dislocation: An MRI evaluation

The medial patellofemoral ligament (MPFL) and the native trochlear geometry represent two of the most critical components of patellofemoral stability. We sought to define the relationship between trochlear dysplasia and MPFL rupture location in patients with documented patellar dislocations. We hypothesized that patients with lower grades of trochlear dysplasia would have patellar based MPFL ruptures, while patients with higher grade dysplasia would have femoral-sided ruptures.We reviewed post-injury MRIs of 59 patients with documented patella dislocation. Information gathered included: type of trochlear dysplasia in the axial plane MRI, location of MPFL rupture, patellar height ratio, tibial tuberosity to trochlear groove distance (TTTG), number of dislocations prior to MRI, and time between the latest patella dislocation and the MRI.Statistical calculations utilized the Chi-Square-Test.We classified 11 cases as a dysplasia type A, 35 as a type B, 11 as a type C, and 2 cases as a trochlear dysplasia type D. In 7 patients (12%) the MPFL rupture was patella based, in 18 patients (31%) intra-ligamentous, in 33 cases (56%) femoral sided and in one case no MPFL could be identified.In contrast to our original hypothesis, the type of trochlear dysplasia does not appear to be related to the rupture location of the MPFL after patellar dislocation. According to our results, it is not possible to presume the location of the MPFL rupture based on assessment of the trochlear morphology. Therefore, a MRI is mandatory for final indication of any surgery.     

Acquired femoral flexion deformity due to physeal injury during medial patellofemoral ligament reconstruction

Background

Reconstruction of the medial patellofemoral ligament (MPFL) is the most frequent surgical procedure performed in patients with patellar instability. Recently, concerns regarding physeal injury during femoral tunnel placement for anatomical MPFL reconstruction in children have been discussed.

不同股骨止点对内侧髌股韧带重建后髌股关节应力影响的三维有限元分析

背景：髌股韧带重建有多种手术方式,其中股骨止点选取对手术实施影响较大,目前针对股骨止点的选取有多种方式,但无定论。目的：通过三维有限元软件分析膝关节不同屈曲状态下内侧髌股韧带（MPFL）股骨重建止点位置改变对髌股关节应力的影响,从而选择出合理准确的股骨重建止点。方法：获取成年人正常膝关节CT数据,导入Mimics、Geomagic及Soildworks软件进行提取模具、添加韧带,其中韧带的股骨止点选择分别为股骨内上髁与内收肌结节连线的中点、股骨内上髁、内收肌结节、股骨髁间窝顶部向内髁投射点和内收肌结节下10 mm,再将添加韧带后的模具导入机械软件Ansys,对不同股骨止点重建后髌股关节应力进行生物力学的有限元分析。结果与结论：（1）在膝关节屈曲0°和30°时,选取任一股骨止点产生的髌股关节应力大于其他屈曲角度（60°,90°,120°）;无论采取哪种位点作为股骨端止点,当膝关节屈曲超过30°时,髌股关节间的接触应力大小基本无差别;（2）在膝关节屈曲0°和30°时,以内收肌结节为止点的髌股接触压力最大,以股骨内上髁与内收肌结节连线的中点为止点的接触力最小;在膝关节屈曲30°时,股骨内上髁...     

Dynamic tracking influenced by anatomy following medial patellofemoral ligament reconstruction: Computational simulation

Background

Continued patellar instability can occur following medial patellofemoral ligament (MPFL) reconstruction. Computational simulation of function was used to investigate the influence of the lateral position of the tibial tuberosity, trochlear dysplasia and patella alta on lateral patellar tracking following MPFL reconstruction.

Histological and cellular evaluation of anterior cruciate ligament

BackgroundWe hypothesized that the torn anterior cruciate ligament (ACL) demonstrates a great healing response after initial trauma and has competent cells leading to the healing but differs in its response based on the type of tear and duration of injury. This study aimed to evaluate the histological and cellular responses to the injured ACL.MethodsFifty-two tissue samples from the ACL were harvested from patients undergoing arthroscopy. Detailed histological and cellular examinations were performed for ligament angiogenesis, fibrocytes, and synovial tissue infiltration. We compared the cellular response to injury in partially and completely ruptured ACLs. The duration of ACL injury and its response to cellular characteristics were also examined. Immunohistochemical studies using cluster of differentiation 34 (CD34) staining was used to evaluate endothelial cells and fibrocytes.ResultsWe found a significantly higher density of synovial and ligament angiogenesis and fibrocytes at the torn end of ACL (Mann–Whitney, P < 0.050). Numerous fibrocytes were identified in complete ACL tears versus partial tears (Mann–Whitney = 0.020). Increased cellular proliferation was identified at the ruptured end of ACL remnant (Kruskal–Wallis, P < 0.050). The cellular proliferation of ruptured ACL decreased after 12 months.ConclusionsBased on our findings of the time-dependent decrease in the cellular response at the torn ends of the ACL, we recommend early intervention, preservation of the ACL remnant, and primary ACL repair or augmented reconstruction.