关节镜下综合治疗复发性髌骨脱位

我院从2004年至今应用关节镜下髌外侧支持带松解，内侧支持带紧缩，胫骨结节移位术综合治疗复发性髌骨脱位12例，疗效确切，现报道如下。     

Bilateral patellar tendon rupture in a child: a case report

Patellar tendon rupture in children is very rare. When it occurs, patellar tendon is usually ruptured either from the upper end as a sleeve fracture of the patella or from lower end as an avulsion fracture of the tibial tuberosity. In this report, we present the case of an otherwise healthy 9-years-old boy who had subsequent bilateral patellar tendon ruptures through the midparts, which has not been published previously in the literature. Treatment was performed with primary end-to-end repair, reinforcement with cerclage wires and fresh-frozen achilles tendon augmentation for both sides.     

Patellar polyethylene peg fracture: a case report and review of the literature

The patellar component of a total knee replacement (TKR) is the most frequent source of non-septic complications after total knee arthroplasty. Fracture of patellar pegs in all polyethylene patellar components is a very rare occurrence. We report such a case of a patellar polyethylene fracture in a 72-year-old female patient 10 years after TKR. Due to patellar malalignment and high level of activity, the patellar components failed in this patient. This was treated arthroscopically by removing the components that failed and leaving the patella unresurfaced. We followed up the patient postoperatively and her symptoms were substantially resolved.     

Reconstruction of the medial patellofemoral ligament for painful patellar subluxation in distal torsional malalignment: a case report

Complex two-level rotational malalignment of the lower extremity can cause maltracking of the patella with anterior knee pain. Double derotation osteotomy would correct the underlying pathology. However, it carries a high risk of complications such as nerve and vessel damage. We report a case of rotational malalignment in the femur and the tibia associated with trochlear dysplasia, which causes painful patellar instability. The patient was successfully treated with reconstruction of the medial patellofemoral ligament and lateral release. Although the malrotation was not addressed, the position of the patella was corrected, and no dislocation occurred during a follow-up of 10 months.     

Tibial tunnel area changes following arthroscopic anterior cruciate ligament reconstructions with autogenous patellar tendon graft

We investigated radiographic changes in tibial tunnel area after ACL reconstructions with autogenous patellar tendon grafts on anteroposterior and lateral radiographs over 3 years. Fifty patients followed up for at least 1 year were included in the study. Radiographs were taken on the day of surgery and 3, 6, 9, 12, 24, and 36 months postoperatively. Tibial tunnels on both radiographs were divided into proximal, middle, and distal one-third. The area of each one-third and the greatest diameter of the tibial tunnel on both radiographs was measured using an image-processing software. According to the tunnel area changes, the shape of tibial tunnel was classified into one of four shapes; cylinder, mallet, reverse bottle, and reverse triangle. The correlations between area, diameter and shape of the tunnel, and clinical variables including arthrometer measurement and clinical score were determined. The areas of each one-third of the tibial tunnels on lateral radiographs was always greater than that on anteroposterior radiographs, although the diameters on the two radiographs did not differ significantly. The area of proximal one-third largest and that of distal one-third smallest on both radiographs at any time point. The enlargement and reduction occurred within 3 months and tended to continue for 9 months. Thereafter the tunnel change stabilized on both radiographs. The most common shape of the enlarged tunnels was cylindrical on anteroposterior radiographs reverse triangle on lateral radiographs. No negative effects of enlarged area, diameter, or tunnel shape on clinical results were found in our study.     

Patients with lateral tracking patella have better pain relief following CT-guided tuberosity transfer than patients with unstable patella

In patients with either lateral tracking patella or unstable patella the pathological lateral position of the tuberosity can be corrected by a medial transfer. This study compared the results of subtle CT-guided correction of the tuberosity for objective unstable patella (n=27) with the results for lateral tracking patella (potential instability) as described by Dejour (n=16). Follow-up was 37 months. CT revealed a pathological lateralization of the tibial tuberosity–trochlear groove greater than 15 mm in 41 knees. These patients underwent medialization of the tibial tuberosity up to 10–12 mm lateral from the trochlear groove, and 28 patients underwent a distalization to normalize the Caton index to 1.0–1.2. Results were evaluated using Cox' method. Patients with objective patellar instability were rated as 11% excellent, 52% good, 33% fair, and 4% poor. All patients became stable except one who had a 6° valgus alignment. Although 96% had improved stability, 33% of the patients still had pain. The patients with lateral tracking patella (potential instability) were rated as 37.5% excellent, 44% good, and 19% fair. The lower proportion of pain relief in patients with unstable patella is likely the result of the cartilage damage experienced by these patients following multiple dislocations. Thus the patient with lateral tracking patella without patella dislocations must be differentiated from the one with unstable patella. Their prognosis in pain relief is better.     

关节镜下自体髌韧带重建膝前交叉韧带术

应用关节镜下自体髌韧带重建膝前交叉韧带的技术和效果。材料与方法自１９９５年１０月至１９９８年８月共８７例经关节镜检查证实为前交叉韧带损伤,部分病人同时伴有半月板、内侧副韧带、关节面软骨或后交叉韧带损伤。     

The influence of the lower patellar pole in the pathogenesis of chronic patellar tendinopathy

Resection of the lower patellar pole provides good results in the treatment of jumper’s knee. Therefore we hypothesized that the length of the lower patellar pole is increased in patients with chronic patellar tendinopathy. Cohort study, level of evidence 2. Between 2000 and 2005, 25 patients with chronic patellar tendinopathy underwent conservative and surgical treatment in our clinic. All of them had preoperative MRI were three independent examiners measured the Caton Index, the length and the ratio of the articular and non-articular patellar surface, tendon length and thickness and the thickness and length of the hypodens lesions in the patellar tendon. The measurements were compared with 50 MRI of a control group with no clinical patellofemoral disorders or patellar tendinopathy. Significant changes in tendon thickness (9.42 ± 2.87 vs. 4.88 ± 1.13; P < 0.0001), a longer non-articular surface of the patella (10.62 ± 2.86 vs. 7.098 ± 2.53; P < 0.0001) and significant higher ratio between the articular and the non-articular patellar surface (0.32 vs. 0.24; P < 0.0001) were found in the jumper’s knee group. No significant changes were seen in the length of the articular surface or the Caton Index. The development of chronic patellar tendinopathy in athletes might be associated with a longer lower patellar pole as patients with jumper’s knee showed a longer non-articular patellar surface compared with the control group.     

What activities do patients with patellar instability perceive makes their patella unstable?

Patellar instability is a disabling musculoskeletal condition. Whilst previous texts have suggested that twisting activities may cause patients to experience instability symptoms, no studies have assessed which activities are related to the patient's perceived instability. The purpose of this study was to determine which activities and with what frequency patients with patellar instability symptoms, perceive their patella to be unstable. Ninety patients referred because of recurrent patellar instability were asked to assess the frequency with which they perceived patellar instability for 19 everyday and sporting activities. The results indicated that sporting and multi-directional twisting activities were more frequently related to patellar instability symptoms, compared to lower energy, uni-planar activities. Females and those without a family history of patellar instability reported more frequent patellar instability symptoms, compared to males, or those with a family history of this disorder. Further study is now recommended to determine whether these results reflect that of patients with milder subluxation disorders, and whether factors such as hypermobility have an impact on perceived patellar instability for this patient group.     

Patello-femoral joint in total knee replacement

Total knee arthroplasty (TKA) surgery is a widely used treatment and has a high success rate. Despite its success, the patello-femoral articulation has been overlooked as a contributor to the successful outcome of TKA. Patello-femoral complications remain the leading cause of failed knee replacement, accounting for up to 10% of complications. To understand the concept of patellar mal-tracking, we explore the normal anatomy and biomechanics of the patello-femoral articulation, and review the surgical factors and complications related to patellar tracking, with an aim to discussing the concepts on how to avoid such complications. Surgeons should be aware of the frequent occurrence of abnormal patellar tracking, and should pay particular attention to the patello-femoral component of knee replacement surgery.