Prevalence of dislocation after total hip arthroplasty through a posterolateral approach with partial capsulotomy and capsulorrhaphy.

The senior author altered his surgical technique during total hip arthroplasty from capsulectomy and capsulotomy with closure of the external rotator muscles to capsulotomy and capsulorrhaphy. One thousand patients (500 treated with each procedure) were studied retrospectively in order to determine the prevalences of dislocation after surgery with the two different techniques. The prevalence of dislocation was 2.8% after the capsulectomy and capsulotomy, whereas it was 0.6% after the new technique; this was a significant decrease in the rate of dislocation (p < 0.005, [symbol: see text] = 0.10).

Luque instrumentation in degenerative conditions of the lumbar spine.

The authors report on the experience obtained in using L-rods and sublaminar wires in obtaining lower lumbar fusions of three or more levels in degenerative diseases of the lumbar spine. A successful fusion was obtained in 86% of the patients. The technique, while offering a satisfactory method of fusion, does violate the spinal canal with sublaminar wires with potential for neurologic injury. Specifically, the passage of sacral wires should be avoided.

Spinal stabilization of vertebral column tumors.

An analysis of indications, techniques, results of stabilization and decompression of 100 consecutive spinal tumour cases was carried out. Localized metastatic disease is best operated anteriorly. Primary malignancies are best treated with en bloc resection. Pain relief in metastatic disease is achieved by rigid stabilization. The unstable spine secondary to benign or malignant disease often requires stabilization for alleviation of pain; 132 stabilization procedures were performed in 100 patients. There were nine benign and 91 malignant tumors including 71 metastatic. Indications for stabilization were pathological fracture or following decompression. Anterior approaches including implant stabilization were used in those with metastatic disease limited to one to two levels or where significant kyphosis existed. Posterolateral decompression with Luque rod stabilization was indicated where disease was more widespread. In metastatic disease acrylic cement was used both anteriorly and posteriorly together with implant stabilization. Eighty-one percent had good to excellent relief of pain; 68 patients had neurological deficits. Significant neurological return was achieved in 40% of posterior decompressions and 71% of anterior decompressions in metastatic disease. All patients with benign tumors have solid fusions. In malignant disease the use of cement provided stability without loss of fixation in 87 of 91 procedures. Complications were 4% infection and failure of two Harrington rods without wiring, one Luque rod and two anterior constructs. The average longevity of patients treated for metastatic disease was 11.3 months.

Techniques of internal fixation for degenerative conditions of the lumbar spine.

The indications and techniques for internal fixation of the lumbar spine in degenerative conditions have changed drastically since internal fixation was first applied to the spine almost 100 years ago. Anterior instrumentation and fusion may be used for repair of pseudarthrosis after posterolateral fusion; symptomatic lumbar scoliosis associated with degenerative disc disease; late pain secondary to posttraumatic kyphosis; postlaminectomy instability; and lumbar pain secondary to thoracolumbar kyphosis. Posterior instrumentation and fusion has been performed with Luque instrumentation over 3-4 levels in cases of multilevel instability. Combined anterior and posterior instrumentation and fusion are required for lumbosacral fusion in lumbar scoliosis with degenerative disease, and surgical correction of postsurgical lumbar kyphosis (flat-back syndrome). The techniques are demanding but with attention to detail can be performed with acceptably low-complication rates.

Simultaneous closed dislocations of the metacarpophalangeal joints of the index, long, and ring fingers: a case report.

A patient with simultaneous closed dislocation of the metacarpophalangeal joints of the index, long, and ring fingers and an ipsilateral fracture of the radius with an associated fracture-dislocation of the distal radioulnar joint is presented. This is the first such case to be described. The mechanism of injury was a fall on an outstretched hand. The dislocations of the metacarpophalangeal joints were successfully reduced by open relocation through dorsal approaches. The fractured radius was treated with open reduction and plate fixation. The patient was placed in a dorsal extension block splint after surgery, and active motion was encouraged. Eleven months later, the patient could make a full fist and extend all fingers. Grip strength was 110 pounds in the right hand, and 100 pounds in the injured left hand.

The function of the anconeus muscle.

The purpose of the present study is to determine whether the anconeus muscle contracts during abduction of the ulna. Abduction of the ulna occurs when pronation takes place around an axis passing through the head of the radius and the second digit. This is in contrast to pronation around an axis passing through the fifth digit, in which the ulna remains relatively stationary. Electromyograms of the anconeus were obtained from five subjects with the elbow supported in 90 degrees of flexion, in full extension, at rest, during supination-pronation around an axis passing through the fifth digit, and during motion around an axis through the second digit. Pronation of the forearm around the axis through the second digit resulted in the greatest amplitude of individual motor unit action potentials and the highest recruitment of additional action potentials. These findings provide evidence substantiating the function of the anconeus muscle as an abductor of the ulna.

Can carbon fiber implants substitute for collateral ligament?

The biomechanic and histologic changes following replacement of the medial collateral digit of the knee with carbon fiber filament prostheses of varying diameters were studied in young rabbits. Biomechanic testing showed changes with time in the mode of failure and force to failure of the replacements, but the initial differences in the force to failure of the three diameter groups diminished over the 12-week experimental period. Histologic studies with both light and electron microscopy revealed resorption of the carbon fibers and replacement by fibrosed ligaments. There was a correlation between the change in mode of failure and force to failure and increased production, orientation, and organization of new collagen fibrils, as well as simultaneous fragmentation of the carbon fibers.

Traumatic recurrent posterior dislocation of the radial head. A case report.

Traumatic recurrent isolated posterior dislocation of the radial head occurred in a 56-year-old woman. The differential diagnosis included congenital dislocation, neurovascular disorders, tumors of the forearm, and Monteggia-type fracture-dislocation. The etiology of the injury is obscure. The treatment of choice depends on the age of the patient and the status of the elbow. The characteristics distinguishing this case from others previously presented in the literature include the recurrence, posterior displacement, and age of the patient.

A comparison between arthrotomy and irrigation and multiple aspirations in the treatment of pyogenic arthritis: a histological study in a rabbit model.

Staphylococcus aureus pyogenic arthritis was produced in a group of eight rabbits. After 24 hours, all rabbits were treated with systemic procaine and benzathine penicillin for five days. Four rabbits were treated with daily aspiration, and four rabbits were treated with arthrotomy and irrigation. A study of the histology of cartilage of the lateral femoral condyle was made in the two groups. Animals treated with aspiration showed a greater degree of thinning of cartilage, acelluiarity, and cloning of chondrocytes than animals treated with arthrotomy and irrigation.