Aneurysmal bone cyst is not encountered frequently and only one previous instance of this lesion of the patella has been reported in the literature. This case, a twenty-two years old R.O.K. army soldier, complained of pain and swelling in the knee joint. Radiologically, the patella was involved, showing a large oval, lytic decreased density with a sharply circumscribed expanded thin margin within the entire patella with an irregular margin at the middle of the articular surface. The patella was excised. Pathological examination revealed grossly and microscopically an aneurysmal bone cyst. The patient made an uneventful recovery, and, two years later, he had a stable knee and no complaints.
Adult ; Bone Cysts*/pathology ; Case Report ; Human ; Male ; Patella*/blood supply ; Patella*/injuries ; Patella*/pathology

Adult ; Female ; Humans ; Patella ; injuries ; surgery ; Patellar Ligament ; injuries ; surgery

Adolescent ; Fractures, Bone ; diagnosis ; Humans ; Male ; Patella ; injuries

Absence of patella may be caused by congenital factors, trauma and surgical operations (patellectomy, etc). Complete absence of bilateral patellae is rare in clinical case. We report a case of posttraumatic bilateral patella excision. To the best of our knowledge, absence of bilateral patellae caused by self-mutilation has never been reported. Our patient and his family members were informed that the data concerning this case would be submitted for publication.
Humans ; Male ; Middle Aged ; Patella ; injuries ; surgery ; Replantation ; methods

Sleeve fractures of the patella are cartilaginous avulsion fractures from the lower pole of the patella. They occur mainly due to sports injuries in adolescents. They may be missed in diagnosis due to rare incidence and small bony fragment on simple radiographs. In this report, an unusual bilateral simultaneous sleeve fracture in a healthy child is described.
Adolescent ; Athletic Injuries ; Child ; Diagnosis ; Humans ; Incidence ; Patella*

There is a dearth of case reports describing simultaneous bilateral patellar tendon ruptures in the medical literature. These ruptures are often associated with systemic disorders such as lupus erythematosus or chronic steroid use. The author describes a case of a 24-year-old man who sustained traumatic bilateral patellar tendon ruptures without any history of systemic disease or steroidal medication. We repaired and reattached the ruptured tendons to the patella and augmented our procedure with allogeneic tendon followed by wire loop reinforcement. One year after operation, the patient regained a satisfactory range of motion of both knees with good quadriceps strength and no extensor lag. The recurrent microtrauma from a history of intense sports activity and a high body mass index may have played an important role in this trauma event.
Humans ; Knee Injuries ; Patella ; injuries ; Patellar Ligament ; Rupture ; Tendon Injuries ; surgery

Simultaneous isolated bilateral patellar fractures are very rare injuries and most often associated with systemic disorders such as hyperparathyroidism, osteoporosis, stress fracture and kidney failure. Isolated bilateral traumatic fracture of patella following an unusual mode of injury is seldomly reported in the literature. We reported such a case following a road traffic accident without any associated injuries or co-morbid condition. The patella on the right side had transverse open fracture which was fixed with two Kirschner wires following tension band principle, and that on the left side sustained upper pole comminution which was treated by partial patellectomy. The patient achieved good outcome: at 6 months he was able to squat and sit cross legged; at one year he obtained nearly normal muscle strength and full range of motion. We discussed the injury mechanism, management and rehabilitation in such a case and reviewed the available literature regarding such a presentation.
Bone Wires ; Fracture Fixation, Internal ; Fractures, Bone ; Fractures, Comminuted ; Humans ; Knee Injuries ; Patella ; injuries

Transverse fracture is the most common in patella fracture and tension band fixation is one of the most effective methods. Surgical wire tension band technique is simple, the use of materials is also simple, but it is not strong and difficult to promote. Kirschner tension band technique can get satisfactory reduction with reliable fixation, but it is easy to complicate with steel wire breakage and Kirschner loosening. Screw tension band technique inherits the traditional advantages of simple manipulation and reliable fixation, also overcomes the disadvantages of early activity limitations caused soft tissue irritation of tension band around knee, the slippage and breakage of internal fixation, and the technique can be popularized generally.
Bone Wires ; Fracture Fixation, Internal ; methods ; Humans ; Patella ; injuries ; surgery ; Stress, Mechanical

With the object of providing a temporary artificial periodonal ligament-like membrane around the dental implant, 10 Branemark type implants were coated with commercially available chitosan(Fluka Co., Buchs, Switzerland) which has a molecular weight of 70,000 and 80% deacetylation degree. Once this bioactive hydrophillic polymer(chitosan) contacts with blood or wound fluids, it becomes swollen and penetrates into the adjacent cancellous bone. Thus the interface between implant and surrounding bone is completely filled with chitosan. This tight junction in early healing phase enhances primary stability. The chitosan coated dental implants were implanted into the fresh patella bones from porcine knees, since the thickness of cortical bone is relatively even and their cancellous structure is homogenous. To test the shock absorbing effect, 1mm delta-rogette strain gage was installed behind the implant. The results showed 1. the principal strain peak value directed to the impact of coated implant was 0.064 0.018(p<0.05) and that of uncoated implant was 0.095(0.032 p<0.05). 2. the peak time delay of coated implant was 0.056sec(0.011 p<0.05) and that of uncoated implant was 0.024sec(0.009 p<0.05). It can be reasoned from this results that the chitosan coating has a shock absorbing effect comparable with a temporary artificial periodontal ligament.
Absorption* ; Chitosan* ; Dental Implants* ; Knee ; Membranes ; Molecular Weight ; Patella ; Periodontal Ligament ; Shock* ; Tight Junctions ; Wounds and Injuries

Kirschner's wire tension band was the first choice in the treatment of patella fracture. But the principle of tension band had been misunderstood for long time. In the traditional principle, it was believed that tension band could change the separating force between fracture fragments into compressing stress when exercising. Eccentric fixation and articular surface cracking were disadvantageous. These could make the fracture fragments separate either at resting or exercising, which cause the gaps without pressure. Thus excercising could not change the separating force into compressing stress.
Biomechanical Phenomena ; Bone Wires ; Fracture Healing ; Fractures, Bone ; therapy ; Humans ; Patella ; injuries