Malcolm L. Ecker

Blood loss after total knee replacement. Effects of tourniquet release and continuous passive motion.

We prospectively studied the cases of 121 patients who were being operated on for insertion of a unilateral total knee prosthesis with cement, and we placed them randomly in four groups. In Group I, the tourniquet was inflated throughout the operative procedure, and we released it postoperatively after a compressive dressing had been applied; a splint was used postoperatively for three days. In Group II, the tourniquet remained inflated throughout the operation, but no splint was applied postoperatively, and continuous passive motion was started immediately in the recovery room. In Group III, the tourniquet was released intraoperatively, and hemostasis was achieved by cauterization; postoperatively, a compressive dressing was applied, and a splint was used for three days. In Group IV, the tourniquet was released intraoperatively, hemostasis was established, and then the tourniquet was reinflated; a compressive dressing was applied, and continuous passive motion was started immediately in the recovery room. Hemoglobin and hematocrit values were monitored in all patients. Blood loss in suction drainage was recorded, and the total blood loss was calculated. The results show that total knee arthroplasty is associated with major loss of blood (mean, 1518 milliliters). The calculated blood loss for Groups I, II, and III averaged 1443 milliliters, while that for Group IV averaged 1793 milliliters. Loss in suction drainage correlated with total estimated blood loss and averaged 511 milliliters. The magnitude of blood loss after total knee arthroplasty should be appreciated, and special attention should be paid to the availability of adequate fluid and blood products, preferably blood donated by the patient preoperatively.

Long-term results after total condylar knee arthroplasty. Significance of radiolucent lines.

In a prospective study of 123 total condylar knee arthroplasties, radiolucent lines were noted at the bone-cement interface about the tibial component in 65% of the knees. In 36%, the line was thin (less than 2 mm) and under either the medial or lateral tibial plateau. In 22%, thin lines were seen under both the medial and lateral plateaus. There was no statistically significant correlation between the occurrence of thin radiolucent lines in any location and the eventual postoperative clinical result. In 7%, thick lines (greater than 2 mm) were noted about the central peg of the prosthesis as well as under both plateaus and were associated with poor results. A 1-mm radiolucent interface was attached to various tibial components, which were then cemented into cadaver knees. For the polyethylene total condylar component, flexion or rotation of the prosthesis more than 5 degrees, angulation of the roentgen beam more than 6 degrees, or offsetting the beam more than 2.5 cm prevented visualization of the radiolucent line. With metal-backed components, more than 4 degrees of flexion obscured the lines. Therefore, extremely careful positioning of postoperative radiographs is essential for evaluating radiolucent lines after total knee arthroplasty.

Aspirin and warfarin for thromboembolic disease after total joint arthroplasty

This study compares the benefits of aspirin and warfarin prophylactic agents for patients with thromboembolic disease after total joint arthroplasty. It is a prospective randomized study of 388 patients having total hip or total knee surgery. All consecutive patients having total hip or total knee surgery were entered into this study and evaluated with preoperative and postoperative ventilation perfusion scans and a postoperative venogram. The aspirin and warfarin treatment groups were compared by size and location of venographically revealed clots and changes in ventilation perfusion scans. The results showed that there was no difference in the size or location of deep venous thrombosis in the aspirin or warfarin treatment groups. The venogram was negative in 44.5% of patients; 28.8% had small calf clots, 16% had large calf clots, 3.9% had popliteal clots, and 6.7% had femoral clots. Patients with total knee replacement had a 2.6 times greater incidence of calf deep venous thrombosis than patients with total hip replacement. There was no difference between the aspirin and warfarin groups in the incidence of changes in ventilation perfusion scans (18.9%). There was no difference between the 2 groups in bleeding complications. The results suggest that aspirin and warfarin are equivalent in prophylaxis against thromboembolic disease, as determined by prevention of venographic changes or changes in ventilation perfusion scans.

Supracondylar fractures of the humerus in children treated by closed reduction and percutaneous pinning.

During the period from 1973 to 1978, 38 children with displaced supracondylar fractures of the humerus were treated at The Childrens Hospital of Philadelphia by closed reduction and percutaneous pin fixation. The technical details of the procedure include (1) reduction under general anesthesia with adequate relaxation; (2) insertion of crossed pins from the medial and lateral side with the elbow in acute flexion; (3) and intraoperative clinical and roentgenographic examination of the pinned fracture with the elbow in extension to determine the adequacy of the reduction, with particular attention to the carrying angle. By Flynns criteria acceptable results were obtained in 19 of the 25 patients studied. Three results were unacceptable due to cubitus varus of 2 degrees, 5 degrees, and 10 degrees, respectively, and three to loss of flexion. Although rotational malalignment occurred in 19 patients, as manifested by a change in shoulder rotation, in no patient was it clinically significant, either cosmetically or functionally. There were no neurologic or vascular complications from the treatment. This is a safe and reliable technique for obtaining and maintaining an excellent reduction in this difficult fracture while preserving vascular function.

Transverse fractures of the patella.

A technique termed longitudinal anterior band with or without cerclage (LAB/C) is recommended for internal fixation of transverse patellar fractures. The fixation is secure even with the existence of considerable comminution in one fragment. The security of this fixation allows early mobilization and the prevention of knee stiffness. The technique involves longitudinal drill holes through which a wire is pulled and looped over the anterior surface of the patella. When folded and tied over the patella, it allows excellent anterior compression and firm fixation. A cerclage wire is applied primarily for marked comminution. Sixteen patients have been treated in this manner with excellent results. To date there have been no complications from wire breakage or fragment distraction, and early motion has been achieved.

Significance of deep venous thrombosis in the lower extremity after total joint arthroplasty.

Thromboembolic disease continues to pose a significant risk to patients undergoing total joint arthroplasty, but the clinical significance of a deep venous thrombosis (DVT) in the postoperative period remains controversial. This report reviews the outcome of 920 patients undergoing prospective obtained venograms after total hip and total knee surgery. Six hundred two patients also obtained postoperative ventilation perfusion scans (V/Q). All patients received one of the following forms of prophylaxis: aspirin (79%), warfarin (16%), or low-molecular-weight heparin (5%). The results show that 39% were without any clot, 36% had small calf thrombi, 19% had large calf thrombi, 2.5% had popliteal thrombi, and 3.8% had femoral thrombi. Calf thrombi occurred almost 2.5 times more frequently after total knee arthroplasty than total hip arthroplasty (67% versus 27%), yet the incidence of pulmonary embolism (PE) is the same in both groups. Intermediate or high probability V/Q results occurred in 103 patients (15%). There was a positive association between the size of a clot and the likelihood of an intermediate- or high-probability V/Q scan. Thromboembolic events resulted in five symptomatic PE (0.5%) and two deaths (0.2%), one in the hospital on warfarin, and one as an outpatient on aspirin. From these data, the authors conclude that calf thrombi by themselves do not place a patient at risk and are not accurate markers of a patient being at risk. Larger clots have a greater likelihood to embolize, but the size of the clot that is clinically significant is undetermined. A significant chance of a PE after discharge from the hospital warrants some form of continuing prophylaxis in outpatients.

Prevention of positional brachial plexopathy during surgical correction of scoliosis

Continuous intraoperative monitoring of spinal cord function using somatosensory evoked potentials (SSEP) has gained nearly universal acceptance as a reliable and sensitive method for detecting and possibly preventing neurologic injury during surgical correction of spinal deformities. In several reports, spinal cord injury was identified successfully based on changes in SSEP response characteristics, specifically amplitude and latency. Less well documented and used, however, is monitoring of peripheral nerve function with SSEPs to identify and prevent the neurologic sequelae of prolonged prone positioning on a spinal frame. The authors describe a patient who underwent surgical removal of spinal instrumentation but was not monitored. A brachial plexopathy developed in this patient from pressure on the axilla exerted by a Relton-Hall positioning frame during spinal surgery. In addition, data are presented from 15 of 500 consecutive pediatric patients who underwent surgical correction of scoliosis between 1993 and 1997 with whom intermittent monitoring of ulnar nerve SSEPs was used successfully to identify impending brachial plexopathy, a complication of prone positioning. A statistically significant reduction in ulnar nerve SSEP amplitude was observed in 18 limbs of the 500 patients (3.6%) reviewed. Repositioning the arm(s) or shoulders resulted in nearly immediate improvement of SSEP amplitude, and all awoke without signs of brachial plexopathy. This complication can be avoided by monitoring SSEPs to ulnar nerve stimulation for patients placed in the prone position during spinal surgery.

The treatment of osteonecrosis of the medial femoral condyle.

Osteonecrosis of the medial femoral condyle presents as a sudden onset of pain on the medial side of the knee. This is associated with a positive bone scan and, frequently, a radiolucent lesion in the subchondral zone. In a review of 79 patients with this disease, performed to establish guidelines for treatment, the patients are divided into three groups according to clinical course and size of the lesion. Group I patients have typical clinical presentation and positive bone scans, but lack radiologic evidence of the lesion. Group II patients have small lesions, with an average diameter of 32% of that of the medial femoral condyle. Group III patients have large lesions, all with diameters greater than 50% of the diameter of the condyle. Patients in Groups I and II obtained relief of pain with conservative treatment; the lesion stabilizes; surgery should be avoided until late degenerative changes become symptomatic. The joints of Group III patients will all collapse rapidly; surgical treatment prior to the development of fixed deformity is advisable.

Lower Extremity Amputation in Diabetic Patients

One hundred and seventy-eight lower extremity amputations performed on 103 diabetic patients were reviewed. Although the healing rate for the above-the-knee amputation was higher, the probability of prosthetic use and ambulation was greater with the mid-leg amputation, particularly if the patient required bilateral amputation. Late breakdown of the mid-leg stump, once healing had occurred, was not a significant problem. We feel that the proper amputation level is bestdetermined by the skin temperature and appearance at the proposed amputation site rather than rigid reliance on the presence of pulses, oscillometry, or arteriography and that every effort should be directed to retaining a functioning knee.

Posterior spinal fusion for scoliosis in patients with cerebral palsy: a comparison of Luque rod and Unit Rod instrumentation.

The development of the U-shaped Unit Rod for posterior spinal arthrodesis is a recent advance in the treatment of spinal deformity in patients with cerebral palsy. The results of 15 patients who underwent arthrodesis with dual Luque rod instrumentation (group I) are compared with the results of 15 patients in whom Unit Rod instrumentation was used (group II). The two treatment groups were similar with respect to age, gender, major spinal curve, and degree of pelvic obliquity. The Unit Rod instrumentation allowed significantly greater correction of both the major curve and pelvic obliquity, as assessed on postoperative radiographs. The mean postoperative major curve in group I was 44.1 degrees, compared with 31.7 degrees in group II (mean corrections of 48.6 and 61.7%, respectively). The mean angle of postoperative pelvic obliquity in group I was 12.6 degrees, compared with 5.2 degrees in group II, corrections of 49.5 and 79.3%, respectively. Sagittal-plane alignment was improved to a similar degree in both groups in those patients with preoperative imbalance and maintained in the remainder of patients.