From bacteriophage lambda to nonlinear dynamics

We describe a successful treatment, intramedullary fibular grafting, for a patient with a supracondylar fracture of the femur following total knee arthroplasty in which the fracture region was comminuted and a segmental large bone defect was present. Free autogenous fibular was inserted into the medullary cavity from the intercondylar region and fixed to the proximal fragment of the femur with augmented fixation using a small plate and screws. Our procedure makes it easy to perform large segmental bone grafting and internal fixation at the same time for such a condition.     

Postprostatectomy dysuria: restored voiding function by perineal hot water spray in an old male with a contractile bladder]

This study reports the first case of a subtrochanteric stress fracture of the femur after total knee arthroplasty. A 61-year-old obese woman was treated by right total knee arthroplasty for osteoarthrosis. Four months after the surgery and 1 month after full weight bearing, she complained of tenderness in the right groin and proximal thigh. There was no history of trauma. Radiographs of the right hip and of the right proximal femur were interpreted as unremarkable, and nonsteroid anti-inflammatory drugs were administered. Three months later, she had a sudden onset of increased pain with instability and giving way of the right leg. Radiographs revealed a subtrochanteric transverse fracture of the right femur. Histologic workup of the bone and tissue specimen taken at open reduction, as well as the laboratory data were consistent with the radiologic and clinical diagnosis of a stress fracture. It is most likely that a decrease in the tension band effect of the iliotibial tract in combination with coxa vara and changes in static and dynamic forces of the femur and an increased level of activity after a period of relative inactivity secondary to the knee arthroplasty are responsible for this very uncommon fracture type.     

Fractures after total knee joint endoprosthesis. Results of treatment with various stabilizing methods

In 20 patients with a fracture of femur or tibia 5.2 years after arthroplasty of knee the results of the operative treatment are presented. The results show that especially bone damaging diseases as rheumatoid arthritis, osteoporosis and the loosening of the endoprosthesis are favorable for the fracture during the follow-up. The conclusion of the investigation shows that in younger patients the external fixation by plates and screws is the preferential treatment, in elderly people or comminuted fracture an internal fixation, also in combination with an additional osteosynthesis, allows a fast mobilization. The number of observed complications is higher than in primary knee arthroplasty, the full weight bearing 1st delayed. The rate of further operations and unsatisfactory results is also higher being affected by the high mean age of the operated patients (73.4 years). The possible use of a total femur implant must be discussed critically because only an individual production can avoid further damage of the parts of the joint that were not concerned by the fracture.     

Protein synthesis blockade differentially affects the stress-induced transcriptional activation of neuropeptide genes in parvocellular neurosecretory neurons

A method of orienting the femoral and tibial bone cuts relative to the endosteal cortex of the femur and tibia was used in 32 patients who underwent revision total knee arthroplasty. The mean orientation of the femoral component was 96.74 degrees +/- 1.03 degrees, mean orientation of the tibial baseplate was 90.71 degrees +/- 1.10 degrees, mean anatomic tibiofemoral alignment was 7.42 degrees +/- 1.69 degrees of valgus, and mean mechanical tibiofemoral alignment was 1.09 degrees +/- 1.83 degrees of valgus. Mean tibial bowing was 1.63 degrees +/- 1.57 degrees of valgus, and mean femoral bowing was 0.58 degrees +/- 1.53 degrees of varus. Valgus tibial bowing was correlated with valgus orientation of the tibial component (r = .86, P < .000001), and varus femoral bowing was correlated with orientation of the femoral component (r = .54, P = .0054). Referencing the implant position from the endosteal cortex of the intramedullary canals provides a reliable method of achieving satisfactory alignment in most revision total knee arthroplasties; however, bowing of the femur or tibia can affect alignment.     

Investigation of the usefulness of CYFRA 21-1 as a tumor marker in squamous cell carcinomas of the head and neck

Compressive contact stress between the patella and the anterior femur and between the quadriceps tendon and anterior femur was measured before and after total knee arthroplasty in 5 cadaver knee specimens using a digital electronic sensor. Contact stresses were measured in the normal knee and after total knee arthroplasty with an unresurfaced patella, a dome-shaped patella, and a conforming patella. Patellofemoral contact stresses did not change significantly after total knee arthroplasty when the patella was not resurfaced, but they increased significantly after the patella was resurfaced with both the dome-shaped and the conforming components. The conforming patella had the highest contact stresses because it tilted at flexion angles greater than 90 degrees and applied load to a small area on the superior portion of the patellar component. The conforming patella markedly decreased tendofemoral contact force because the thicker superior pole of the patella tented the quadriceps tendon at flexion angles greater than 120 degrees. This further increased patellofemoral contact force in deep knee flexion.     

Nonselective debridement and antimicrobial cleansing of a venting ductal breast carcinoma

Supracondylar femur fractures above a total knee replacement are rare injuries that may be challenging to treat. We present a case of an elderly woman whose supracondylar femur fracture was not deemed amenable to conventional treatment. This patient underwent fixation of her femur fracture above a total knee replacement using an Ilizarov external fixator. The fixator was removed at 10 weeks, at which time the fracture was solidly healed. At the most recent follow-up, the patient is 19 months postinjury. She is fully weight bearing without walking aids and has a knee range of motion of 0 degree to 110 degrees.     

A PCR-RFLP method for the detection and species identification of human microsporidia

Amputation in a growing child should be performed through a joint and not above or below a joint, as is commonly the case in an adult. We describe a technique for performing a through-knee amputation in a situation in which a soft-tissue sarcoma involved a leg, reaching up to the knee joint. Soft-tissue dissection was performed above the knee, leaving a safe zone from the tumor. The distal femur was dissected free of all attachments to the tibia and leg, leaving it intact but protruding from the soft-tissue sleeve of the thigh. To be able to close the stump over the protruding distal femur, the femur was shortened in the metaphysodiaphyseal area. Follow-up over 3 years shows a good through-knee stump, tumor free, and a normal distal growth plate.     

Confirmed abuse cases in public residential facilities for persons with mental retardation: a multi-state study

Our experience with 10 patients who suffered midshaft fractures of the femur and injuries to their ipsilateral hips has resulted in a treatment protocol that we believe can avoid unnecessary complications. The surgical protocol is a three-stage procedure based on (1) intramedullary nailing of the femur with interlocking for preserving the anatomic length and rotation of the femur; (2) treatment of the hip joint injury by means of open reduction and internal fixation of the acetabular fracture and/or reduction and fixation of the fractured femoral neck; and (3) repair of the extensor mechanism. Eight patients received this treatment and had fast recoveries. Union of the femoral fracture and full range of motion of the knee joint were observed within 3 months. In contrast, two patients who had received different surgical treatment had incomplete functional recoveries. This study offers a treatment protocol for ipsilateral disruption of the extensor mechanism, hip joint injury, and midshaft fracture of the femur in the multiply injured patient that can achieve full recovery with no complications. This relatively rare combination of injuries is definitely worthy of special attention.     

2-stage reimplantation for infected total knee replacement

Between 1977 and 1983, 64 infected total knee replacements in 60 patients were treated with a 2-stage protocol for reimplantation. The clinical results and survivorship were determined at an average followup of 7.5 years (range, 2-17 years). Surgical protocol included removal of the prosthesis and all cement with thorough debridement of bone and soft tissues. This was followed by 6 weeks of parenteral antibiotics and then reimplantation of a new prosthesis. At followup, 6 knees (9%) had become reinfected, but only 2 with the same organism. Four knees had been revised: 3 for aseptic loosening and 1 for a periprosthetic femur fracture. Two other knees were impending failures due to aseptic loosening. The average Hospital for Special Surgery knee score was 78 points with 18 excellent, 28 good, 13 fair, and 5 poor results. Seventy-eight percent of patients were satisfied with the overall result of their reimplanted prosthesis and 95% think that they made the right decision in undergoing total knee arthroplasty. The 10-year predicted survivorship of 2-stage reimplantation is 77.4%. Two-stage reimplantation with a 6-week course of parenteral antibiotics is an effective means to eradicate deep infection and to provide a functional knee. The long term functional results and overall survivorship are comparable with the results of revision of aseptic failed total knee arthroplasty.     

Intramedullary pressure and pulmonary function during total knee arthroplasty

Twenty-eight patients who underwent unilateral total knee arthroplasty and 20 patients who underwent simultaneous bilateral total knee arthroplasties participated in this study and were randomized to have either a fluted or round 10-mm diameter femoral intramedullary alignment rod used during surgery. The intramedullary rods were cannulated and connected with pressure tubing to a monitor which provided measurements of pressure at the tip of each rod. Arterial blood gas measurements on room air were obtained before and on the morning after surgery. An arterial line was placed and an arterial blood gas measurement was obtained at the time of skin incision and again after tourniquet release. Pulmonary shunt was calculated from the arterial blood gas measurements. Intramedullary pressure during rod insertion was significantly higher for the groups of patients having the round compared with the fluted rod. The change in pulmonary shunt during surgery was lowest for the patients in the unilateral group having the fluted rod and highest for the patients in the bilateral group having the round rod. A fluted rather than a round intramedullary alignment rod should be used to minimize intramedullary pressure and pulmonary shunting during unilateral and bilateral total knee arthroplasties.     

Retrograde intramedullary nailing of supracondylar femoral fractures

As an alternative to standard AO/Association for the Study of Internal Fixation plate and screw techniques, retrograde intramedullary locked nailing of supracondylar and intracondylar (AO/Association for the Study of Internal Fixation Type 33) fractures is reviewed. This includes a historic review, the technique for knee arthrotomy, fracture reduction and nail insertion, and the reported clinical and biomechanical results. The retrograde intramedullary locked nail is a viable alternative for the treatment of AO/Association for the Study of Internal Fixation Type 33-A and some C supracondylar femoral fractures and should be part of the internal fixation armamentarium, however, it does not replace the standard biologic plate and screw techniques for most fractures.     

Heterotopic ossification following total knee arthroplasty requiring surgical excision

We present a case of progressive heterotopic ossification (HO) after cementless total knee arthroplasty causing painful stiffness that was treated with surgical excision. The patient had few risk factors associated with HO, including minimal anterior notching and dissection of the distal femoral cortex. The patient did undergo manipulation; however, this occurred after the diagnosis of HO was made. This report documents a rare case of HO following total knee arthroplasty that required surgical excision.     

Minimally invasive method for treatment of supra-diacondylar femoral fractures

The "gold standard" treatment modality for extra-articular and combined intra-, extra-articular fracture of the distal femur is the condylar blade plate (CP). Large exposure of the distal femur with unavoidable iatrogenic trauma to the soft tissue surrounding the fracture site and perhaps the lack of stiffness of the eccentric lateral cortical location of the CP has been suggested to play a role in the high rate of infections and pseudarthrosis reported in the literature. In an effort to overcome some of the difficulties with the condylar blade plate and to reduce complications, an unreamed, titanium, solid nail, locked proximally with two locking screws and distally with a screw and twisted blade was developed (DFN). The nail was designed for minimal invasive reduction through a small median parapatellar arthrotomy of the articular fracture (percutaneous screw) and of the supracondylar fracture. The DFN is a modular system sharing many components and almost all instrumentation with the AO-UFN and it is expected that the nail is much better in axial stiffness and strength than the condylar blade plate. The treatment of supracondylar femoral fractures should be improved by providing early weight bearing and accelerated fracture healing with a reduced incidence of delayed unions and infections.     

Obscure distal femoral epiphyseal injury

Undisplaced type I epiphyseal fracture of the distal femur in the adolescent athlete may mimic injury to a ligament. Roentgenographic examination with the knee under stress will reveal the diagnosis, thereby avoiding unnecessary arthrotomy and dictating appropriate treatment and follow-up.     

The effect of femoral component position on the kinematics of total knee arthroplasty

In a laboratory study using seven fresh-frozen anatomic specimen knees, the effect of total knee arthroplasty on the three-dimensional kinematics of the patella, femur, and tibia were measured. Experiments were performed in the intact knee, after division of the anterior cruciate ligament (ACL), after total knee arthroplasty, and after 10 degrees internal rotation, 10 degrees external rotation, 5-mm medial shift, and 5-mm lateral shift of the femoral component on the femur. The presence of a high lateral ridge on the anterior surface of the femoral component effectively prevented patellar subluxation or dislocation, but displaced and tilted the patella medially. Internal rotation or medial displacement of the femoral component exaggerated this medial patellar displacement and shift. External rotation of the femoral component corrected it, except at flexion angles greater than 100 degrees, where the femur was shifted medially on the tibia and externally rotated 15 degrees. This combination produced a net 10-mm medial displacement of the patella relative to the tibia at 120 degrees knee flexion. Lateral placement of the femoral component compensated for the effect of the high lateral ridge and allowed more normal patellar tracking while allowing tibiofemoral motions similar to those seen after sectioning of the ACL. The kinematics of the patellofemoral and tibiofemoral joints were not reproduced with a total knee prosthesis that sacrifices the ACL. When using a prosthesis with a high lateral ridge, lateral placement of a femoral component prevented patellar dislocation and allowed patellar tracking patterns similar to those seen in the intact knee without further altering tibiofemoral motions.     

Intrafemoral pressure measurement in different cement removal procedures during hip prosthesis replacement operations--experimental study with cadaver femora

During primary hip arthroplasty an increase in intramedullary pressure (IMP) of up to 1000 mm Hg can be observed. As a result of this increased intrafemoral pressure, intramedullary constituents can pass into the venous circulation creating a risk of fat embolism syndrome (FES). In the present experimental study on 9 femora obtained from human corpses, we investigated the question as to whether various methods of cement removal during total hip revision arthroplasty are also associated with increased intramedullary pressure and a risk of FES. The IMP was recorded with a standardized experimental set-up during removal of cement from the proximal and distal regions, including removal of the cement "tip" and the intramedullary plug. The methods employed for this purpose included the osteotome and mallet, a compressed air powered chisel, and a modified intracorporal lithotripter. All the methods induced fluctuations in the IMP the highest values being recorded for the conventional method using the osteotome and mallet (45 mm Hg) and the lowest values for the intracorporeal lithotripter (7.5 mm Hg). Working on the distal cement caused higher fluctuations in comparison with the proximal region. The study failed to reveal any increase in mean IMP, and all measured values were in the low pressure range (considerably below 150 mm Hg). While there seems to be no apparent risk of an FES developing during removal of cement, careless manipulation of the distal cement plug may result in higher intrafemoral pressures--above 150 mm Hg--thus increasing the risk of a fat embolism syndrome.     

Biomechanical stress studies with a new Y-nail

The current success of the treatment of trochanteric fractures of the femur still depends on the type of fracture involved. A number of surgical procedures have proved successful in the treatment of stable fractures (e.g. dynamic hip screw, gamma nail). However, the treatment of unstable fractures remains a problem. With this type of fracture the implant is exposed to very unfavourable biomechanical loading that often leads to failure of the osteosynthesis, and makes removal of the implant necessary. In extensive tests, the biomechanical loading capacity of a new Y-nail has been investigated as a function of the stability and location of the fracture. The results show that this form of intramedullary fixing is suitable for both stable and unstable fractures. Unstable, far distal subtrochanteric fractures of the femur remain borderline indications.     

Nonunion after a tibial shaft fracture complicating tibial tubercule osteotomy

Tibial shaft fracture after tibial tubercle osteotomy in total knee replacement is a rare complication. We report on a 67-year-old man who had a knee revision arthroplasty in which a long tubercle osteotomy was performed to facilitate exposure. Three weeks after surgery, he presented with a transverse shaft fracture, which became a nonunion requiring surgical management. This shaft nonunion and its solution after tibial tubercle osteotomy is discussed as well as relevant literature.     

Patellofemoral complications in symmetrical total knee arthroplasty

A review of 356 Kinemax (Howmedica, Inc, Rutherford, NJ) cemented posterior cruciate ligament-retaining condylar total knee arthroplasties employing a symmetrical femoral component articulating with a medially offset symmetrical dome patella component was carried out to examine the results and determine the incidence and nature of the patellofemoral complications. Follow-up was from 3 to 8 years, with a mean of 5.1 years. A review of patellofemoral complications in previously reported homogeneous series of symmetrical and asymmetrical implants is presented. Mean postoperative Knee Society scores improved to 91, function scores to 86, and Hospital of Special Surgery scores to 90 yielding 95% good and excellent results. Mean postoperative range of motion was -1.5 degrees extension to 113 degrees flexion. There were five patellofemoral complications (1.4%), including two symptomatic subluxations, two distal pole avulsion fractures, and one lateral facet fracture. There were two reoperations necessary for patellofemoral problems (0.56%), one to correct subluxation and one for excision of the fractured lateral facet. These rates are lower than those previously reported for asymmetrical implants as well as current and phased-out symmetrical designs of total knee arthroplasty in the intermediate term. This review suggests that cemented total knee arthroplasty with symmetrical patellofemoral resurfacing with an offset patella dome and posterior cruciate ligament retention yields low patellofemoral complications and reoperations. The symmetrical femoral component appears to be a satisfactory compromise of "normal" femoral anatomy, which decreases inventory and cost without adversely affecting patellofemoral function and complications.     

Aerial fallout of DDT in southern California

Ender's method of intramedullary fixation of intertrochanteric and subtrochanteric fractures is described. Ender's nail is a pre-bent flexible steel nail with a diameter of 4.5 millimeters. Three to five of these nails are inserted from a small incision proximal to the medial epicondyle of the femur into the medullary canal. They are passed through the femur across the fracture site and into the head of the femur, where they diverage. They are in the lines of force and therefore are not subjected to bending moments. The fracture fixation allows immediate weight-bearing. This method of fixation was used in a series of 203 patients. Their average age was sixty-eight years; the mortality rate was 10.3 per cent. In 3.9 per cent superficial infections occurred, but in no case was there a deep infection involving the bone. Functional return (walking) was achieved in all of the survivors who were able to walk at the time of injury, and there were no nonunions.