In view of the current level of knowledge and the numerous treatment possibilities, none of the existing classification systems of thoracic and lumbar injuries is completely satisfactory As a result of more than a decade of consideration of the subject matter and a review of 1445 consecutive thoracolumbar injuries, a comprehensive classification of thoracic and lumbar injuries is proposed The classification is primarily based on pathomorphological criteria Categories are established according to the main mechanism of injury, pathomorphological uniformity, and in consideration of prognostic aspects regarding healing potential The classification reflects a progressive scale of morphological damage by which the degree of instability is determined The severity of the injury in terms of instability is expressed by its ranking within the classification system A simple grid, the 3-3-3 scheme of the AO fracture classification, was used in grouping the injuries This grid consists of three types: A, B, and C Every type has three groups, each of which contains three subgroups with specifications The types have a fundamental injury pattern which is determined by the three most important mechanisms acting on the spine: compression, distraction, and axial torque Type A (vertebral body compression) focuses on injury patterns of the vertebral body Type B injuries (anterior and posterior element injuries with distraction) are characterized by transverse disruption either anteriorly or posteriorly Type C lesions (anterior and posterior element injuries with rotation) describe injury patterns resulting from axial torque The latter are most often superimposed on either type A or type B lesions Morphological criteria are predominantly used for further subdivision of the injuries Severity progresses from type A through type C as well as within the types, groups, and further subdivisions The 1445 cases were analyzed with regard to the level of the main injury, the frequency of types and groups, and the incidence of neurological deficit Most injuries occurred around the thoracolumbar junction The upper and lower end of the thoracolumbar spine and the T 10 level were most infrequently injured Type A fractures were found in 661 %, type B in 145%, and type C in 194% of the cases Stable type Al fractures accounted for 347% of the total Some injury patterns are typical for certain sections of the thoracolumbar spine and others for age groups The neurological deficit, ranging from complete paraplegia to a single root lesion, was evaluated in 1212 cases The overall incidence was 22% and increased significantly from type to type: neurological deficit was present in 14% of type A, 32% of type B, and 55% of type C lesions Only 2% of the Al and 4% of the A2 fractures showed any neurological deficit The classification is comprehensive as almost any injury can be itemized according to easily recognizable and consistent radiographic and clinical findings Every injury can be defined alphanumerically or by a descriptive name The classification can, however, also be used in an abbreviated form without impairment of the information most important for clinical practice Identification of the fundamental nature of an injury is facilitated by a simple algorithm Recognizing the nature of the injury, its degree of instability, and prognostic aspects are decisive for the choice of the most appropriate treatment Experience has shown that the new classification is especially useful in this respect

A comprehensive classification of thoracic and lumbar injuries

These guidelines are intended for use by infectious disease specialists, orthopedists, and other healthcare professionals who care for patients with prosthetic joint infection (PJI). They include evidence-based and opinion-based recommendations for the diagnosis and management of patients with PJI treated with debridement and retention of the prosthesis, resection arthroplasty with or without subsequent staged reimplantation, 1-stage reimplantation, and amputation.

/pdf/diagnosis-and-management-of-prosthetic-joint-infection-4ogdeimcv4.pdf

Diagnosis and Management of Prosthetic Joint Infection: Clinical Practice Guidelines by the Infectious Diseases Society of America

Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided.

/pdf/prosthetic-joint-infection-20eesbrxfa.pdf

Prosthetic Joint Infection

https://www.oarsijournal.com/article/S1063-4584(01)90504-7/pdf

Human autologous culture expanded bone marrow mesenchymal cell transplantation for repair of cartilage defects in osteoarthritic knees

The objective of this study was to quantify the coacti vation patterns of the knee flexor and extensor muscles as part of continued efforts to identify the role of the antagonist muscles in maintaining joint stability.The simultaneous EMG from the flexor and extensor muscles of the knee were recorded during maximal effort, slow isokinetic contractions (15 deg/sec) on the plane parallel to the ground to eliminate the effect of gravity. The processed EMG from the antagonist mus cle was normalized with respect to its EMG as agonist at maximal effort for each joint angle. The plots of normalized antagonist EMG versus joint angle for each muscle group were shown to relate inversely to their moment arm variations over the joint range of motion. Additional calculations demonstrated that the antago nist exerts nearly constant opposing torque throughout joint range of motion. Comparison of data recorded from normal healthy subjects with that of high perform ance athletes with hypertrophied quadriceps demon strated...

Muscular coactivation The role of the antagonist musculature in maintaining knee stability

The patella contributes to the knee extension moment arm through the entire range of knee motion. Its contribution increases with progressive extension. In terms of extension moment, special modifications of transverse repair have no advantage over simple transverse approximation of the patellar lig

Mechanical function of the patella.

Ten fresh human upper-extremity cadaver specimens were tested for the effect of residual angulation from simulated fractures of both bones of the forearm on the potential for range of rotation of the forearm and for limitations of pronation and supination specifically. Ten and 20-degree angulations for the radius and ulna, such as might be encountered in all reasonable clinical situations, were tested. Little significant loss of forearm rotation resulted from angulations of 10 degrees in any direction. With 20 degrees of angulation, there was statistically significant and functionally important loss of forearm rotation. Clinical Relevance: A residual angulation of 10 degrees in mid-shaft fractures of the radius, ulna, or both bones of the forearm will not limit forearm rotation anatomically. Loss in the range of rotation can be expected with residual angeles of 20 degrees or more.

The effect on supination-pronation of angular malalignment of fractures of both bones of the forearm.

Survival analysis studies of 40 patients treated with high tibial osteotomy for arthritis with angular deformity were performed to determine the dominant factors that adversely affected long-term knee function. Obesity, advanced age, and postoperative overcorrection or undercorrection resulted in short durations of successful function. On the average, the probabilities for continued useful function of the knee at tested intervals were: one year, 86%; three years, 64%; five years, 50%; and nine years, 28%.

Proximal tibial osteotomy. Factors that influence the duration of satisfactory function

Of twenty-four lumbar-spine fractures observed in seat-belt wearers, twenty showed an Unusual and consistent pattern of injury characterized by separation of the posterior elements without the usually expected decrease in height of the anterior portion of the vertebral bodies.

It is suggested that tension stress is primarily responsible for the unusual patterns seen in these injuries.

A mechanism by which large tension forces may be brought to bear on the lumbar spine has been described.

Although the lap seat belt is instrumental in producing the lesion described, this report is in no way an indictment of the lap-type seat belt. All of the lesions studied were products of very severe collisions. We are convinced that if these individuals had not been wearing seat belts, they would not have survived. It is likely that these injuries might not have occurred if the patients had been wearing shoulder-type seat belts. The possibility that the shoulder harness might focus similar stress at the cervicothoracic junction with production of a far more serious spine injury remains a matter of conjecture.

Patterns and mechanisms of lumbar injuries associated with lap seat belts

The combined roles of three different positions of reduction and three different fixation devices in stabilization of a standard four-fragment intertrochanteric fracture were studied to determine which combination would best support the load of weight-bearing. Experimental four-part fractures were produced in forty-one pairs of embalmed adult femora. These fractures were stabilized using an anatomical reduction position, the Dimon-Hughston position of medial displacement, and the Wayne County General Hospital position of slight lateral and upward displacement of the femoral shaft fragment, combined with Jewett nail, telescoping screw, and Holt nail implants in all combinations. The stabilized specimens were loaded to failure and examined for the maximum load supported and for resistance to continued deformation under load. The implant device was found to play the major role in fixation stability. The three positions of reduction exerted only a minor influence on the maximum load supported.

Herbert Kaufer

Papers

Mechanical function of the patella.

The effect on supination-pronation of angular malalignment of fractures of both bones of the forearm.

Proximal tibial osteotomy. Factors that influence the duration of satisfactory function

Patterns and mechanisms of lumbar injuries associated with lap seat belts

Stable fixation of intertrochanteric fractures.