Measurement of anterior-posterior motion of the knee in injured patients using a biomechanical stress technique.

We performed biomechanical stress tests preoperatively on the knees of fifty-one patients with an injury to the knee. We measured the amount of anterior and posterior tibial translation at 90 degrees of knee flexion using a roentgenographic technique and a fifty-newton joint load. Knees with an isolated meniscal tear exhibited no abnormal motion. There was no difference in motion of the knee between patients with a rupture of the anterior cruciate ligament and patients with this injury who had had a prior medial meniscectomy. We found that prior knee surgery that was not associated with stability did not adversely affect the test procedure. A significant finding, however, was that only nineteen of twenty-five patients with a ruptured anterior cruciate ligament had greater excursion on the injured side compared with the uninjured knee. Because of this inconsistent result, a biomechanical stress test at 90 degrees of knee flexion measuring anterior and posterior translation under a fifty-newton joint load appears insufficient in itself to be of clinical use.

Retrieval analysis of total knee prostheses: a method and its application to 48 total condylar prostheses.

A technique for the classification and quantification of damage in retrieved total knee prostheses is presented and applied to the examination of 48 removed total condylar-type knee replacements. The technique involves inspection of all metallic and polyethylene components for evidence of gross deformation, fracture, and damage to articulating surfaces. A grading system was developed to quantitate surface damage on polyethylene components. Results of the examinations are combined with patient variables (weight, activity level, radiographic findings, time of implantation, and results of histology performed on surrounding tissue) to determine correlations between clinical variables and the mechanical damage experienced by the prostheses. For the 48 total condylar-type prostheses, significant positive correlations were found for the surface damage correlated with the patient's weight and the time the prosthesis was implanted.

Anterior exposure of the cervicothoracic spine using a combined cervical and thoracic approach.

Anterior stabilization of severe structural deformities of the spine, especially kyphoscoliosis, at the cervicothoracic level is a difficult surgical procedure. A new combined procedure including anterolateral cervical and posterior transpleural transthoracic approaches to the cervicothoracic spine provided adequate-exposure from the third cervical to the ninth thoracic vertebra and at the same time gave access to the great vessels in the event that control of these became necessary. The procedure has been employed in six patients with severe cervicothoracic kyphoscoliosis. Despite the magnitude of the combined cervical and transthoracic exposure, the patients withstood the procedure well and there were no complications. The fusion was successful in all six patients. The kyphotic deformities were corrected by an average of 26 degrees and the scoliotic curves, by an average of 17 degrees.

The total condylar knee prosthesis in gonarthrosis. A five to nine-year follow-up of the first one hundred consecutive replacements.

We studied the first 100 consecutive patients (125 knees) to undergo knee arthroplasty with the original total condylar-I prosthesis for either osteoarthritis or osteonecrosis on the Knee Service at The Hospital for Special Surgery. They were followed for an average of 6.6 years (range, five to nine years), which is the longest follow-up of a total knee prosthesis that is still widely used in its original and unmodified form. At five to nine years of follow-up, eleven patients (fourteen knees) were dead and ten patients (eleven knees) could not be traced, leaving 100 knees (seventy-nine patients) for clinical evaluation. This included one knee from which the prosthesis was removed for sepsis at six months, four that were revised for pain, and two that were revised because of subluxation. Two patients had a loose tibial component. Sixty-four knees were rated as excellent and twenty-seven were rated as good. There were two fair and seven poor results. Detailed radiographic evaluation of the 100 knees showed that only minimum changes in the varus or valgus alignment or the fixation of the prosthetic components had occurred with time. At follow-up, 41 per cent of the tibial components showed some evidence of radiolucency, although with the exception of the two loose components just mentioned there were no complete or circumferential radiolucent lines. Most radiolucencies were present by the end of the first postoperative year, and in 81 per cent of the knees there was no further change. Although a special attempt was made to determine any evidence of wear of the polyethylene tibial component, we were unable to demonstrate unequivocal wear in any knee. Our experience had led us to conclude that the long-term success of current total knee designs will probably not be significantly affected by polyethylene wear or loss of component fixation. The majority of failures in our series were attributed to errors in surgical technique.

Bone-block transfer of the medial head of the gastrocnemius for posterior cruciate insufficiency.

An operation is described in which the medial head of the gastrocnemius is firmly fixed by a cancellous screw, through an attached bone block, to the medial femoral condyle to serve as an intraarticular graft for the control of chronic posterior instability of the knee. This procedure was done in eight patients, with a follow-up of twenty-nine to forty-eight months. The delay from injury to reconstruction averaged forty-two months (range, five to eighty-four months). At follow-up, stability was improved in all of the eight patients and the result was rated as good or excellent in six of them. One failure was due to unrelieved pain and in another patient a second injury led to reoperation. Because minimum immobilization is necessary, the postoperative care with this procedure is simplified and the period of rehabilitation is shorter.

Peroneal-nerve palsy following total knee arthroplasty. A review of The Hospital for Special Surgery experience.

Twenty-three postoperative peroneal-nerve palsies in twenty-two patients were documented in the records of 2626 consecutive knee arthroplasties that were performed at The Hospital for Special Surgery from 1974 through 1980. This is an incidence of 0.87 per cent. The preoperative knee deformities included fourteen flexion contractures, eleven valgus deformities, and five biplane deformities. In five patients a peroneal palsy developed despite a peroneal-nerve release at the time of arthroplasty. Only two patients, who initially had only a motor loss, had a complete clinical recovery. Follow-up ranged from six months to seven years (average 3.1 years). Sensory deficits, initially noted in eighteen patients, had not fully resolved in any patient at the time of writing. Although motor deficits were initially noted in all patients, only 28.6 per cent of them fully resolved. The possible causes of the nerve palsy appeared to be direct traction on the nerve, traction on the surrounding tissues resulting in vascular compromise to the nerve, direct pressure on the nerve from the postoperative dressing, or a combination of these factors. When the palsy is discovered, the suggested treatment is a change to a looser dressing and flexion of the knee. The value of surgical exploration of the nerve in the immediate postoperative period is not known.

The correction of knee alignment in 225 consecutive total condylar knee replacements.

Two hundred twenty-five consecutive total knee replacements were reviewed radiographically to determine final alignment of the leg and accuracy of component placement. Of the 126 knees that were in varus preoperatively, only one knee was found to be in varus after knee replacement. Eighty-nine percent of the knees were found to be in 7 degrees +/- 5 degrees of valgus postoperation, while 7 degrees were in greater than 12 degrees valgus, 4 percent were in neutral position. Severe instability in the mediolateral plane was noted preoperatively in 62 knees in this series. Correction of more than 15 percent of deformity was necessary in 34 varus knee and 15 valgus knees. However, there has been no failure in the series attributable to instability in the mediolateral plane. Anteroposterior stability is controlled by the prosthesis design.

Lengthening of the lower extremity by the Wagner method. A review of the Boston Children's Hospital Experience.

Thirty-eight patients underwent forty lengthenings of the lower extremity between October 1972 and January 1979. There were twenty-four femoral and sixteen tibial lengthenings. The average length gained was 6.59 centimeters for the patients with femoral lengthenings and 4.77 centimeters for those with tibial lengthenings. While the over-all complication rate was high (92 per cent), it did not significantly affect the ultimate goal of equalization of limb length. We think that the Wagner method is the procedure of choice for continuous distraction lengthening when the severity of the limb-length inequality merits major surgical intervention.

Draft dodger's knee: unusual pattern of calcification in the knee secondary to olive oil injection: a case report.

In an effort to avoid military conscription, an occasional potential draftee would inject olive oil into the knee. The resulting swelling that occured enabled some of these individuals to avoid military service through involuntary induction. The long-term effects of this procedure can now be seen.

Diastematomyelia and structural spinal deformities.

Sixty patients with diastematomyelia were seen over a thirty-year period and congenital scoliosis was found in 60 per cent. All of the patients had associated vertebral abnormalities and most (87 per cent) had a neural deficit. Myelography was helpful in the diagnosis, particularly prior to any procedure that might cause traction on the spinal cord. Laminectomy for removal of the spur was indicated when neural deficits were progressive or before corrective surgery on the spine, and in ten patients the operation alleviated neural sequelae. Observation of patients with diastematomyelia who have no neural deficit or a stable, non-progressing deficit is recommended.