Paul A. Lotke

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.

Magnetic resonance imaging in the evaluation of suspected osteonecrosis of the knee

Magnetic resonance imaging (MRI) was performed on 19 patients with suspected or proven osteonecrosis of the knee. The results were compared to radionuclide and plain radiographic studies when possible. The patients were grouped into one of three categories: patients with disease predisposing them to osteonecrosis (e.g., systemic lupus erythematosus (SLE), steroid use, and renal transplants), older patients without risk factors with acute onset of symptoms, and patients with knee pain months or years following trauma.In six patients with symptoms and predisposing diseases, MRI was abnormal in four cases, all of whom had bilateral abnormalities. In the ten older patients with classical symptoms, MRI was abnormal in seven, and bilateral abnormalities were present in three patients. The three patients with a history of antecedent trauma had normal MRI studies. Two patients with history and scintigraphic cvidence of osteonecrosis had negative MRI scans. MRI may be of value in patients with suspected or proven osteonecrosis of the knee by demonstrating bilateral disease in patients with unilateral symptoms, showing the extent of involvement, and establishing the presence or absence of bone marrow changes in patients with positive bone scans and negative plain films.

Response bias: effect on outcomes evaluation by mail surveys after total knee arthroplasty.

BACKGROUNDnMail survey questionnaires are increasingly being used for follow-up evaluations to gauge satisfaction and performance after total joint arthroplasty. Responses to questionnaires are subject to a variety of possible biases. We evaluated response behavior in a mail survey of patients who had had a total knee arthroplasty.nnnMETHODSnA ten-question survey that evaluated satisfaction, general health, and Knee Society knee function and clinical scores was mailed to 472 patients who had undergone consecutive primary total knee arthroplasties from 1996 to 1998. The 83% who responded were stratified as early, late, and repeat-mailing responders. The 17% who failed to respond after two mailings were considered nonresponders. All of the nonresponders were eventually contacted. The groups were compared with regard to their scores at the preoperative office visit, at the most recent office visit, and on the mail survey.nnnRESULTSnIn the mail survey, the patients who responded earliest gave the highest satisfaction ratings and the nonresponders gave the poorest ratings (p < 0.001). Similarly, the mean Knee Society knee score (and standard deviation) was significantly higher for the early responders (82.7 +/- 19.0) than for the nonresponders (66.9 +/- 16.0), as was the mean function score (68.8 +/- 24.1 compared with 48.4 +/- 12.5) and the mean pain score (39.8 +/- 13.9 compared with 27.0 +/- 9.7) (all p < 0.0001). The change between the preoperative and mail survey Knee Society knee scores was significantly higher for the early responders (46.12 +/- 25.71) than for the nonresponders (28.45 +/- 23.62), as was the change in the mean function scores (18.87 +/- 22.52 compared with 5.34 +/- 20.05) and the change in the mean pain scores (23.57 +/- 17.76 compared with 10.67 +/- 12.93) (all p < 0.0001).nnnCONCLUSIONSnPatients who do not respond to mail surveys used for follow-up are unique in that they report significantly poorer outcomes than do responders. This potential response bias should be considered in all follow-up analyses. Because it may be difficult to attain 100% response rates in very large series of patients, division of the study cohort into more manageable segments is advised to achieve a more complete response rate. The assessment of patients who are lost to follow-up is an important and necessary component in the accurate analysis of outcomes after arthroplasty.

Use of a trabecular metal patella for marked patella bone loss during revision total knee arthroplasty

This study evaluates the short-term results following patellar resurfacing with a trabecular metal patella shell in the setting of marked patellar bone loss at the time of revision total knee arthroplasty (TKA). Twenty consecutive patients undergoing revision TKA with the use of a trabecular metal patella were evaluated at a mean 23-month follow-up. All patients had marked patellar bone loss at surgery precluding resurfacing with a standard cemented patellar button. Results were good or excellent in 17 of 20 patients. There were no displacements of any trabecular metal patella shells, and the fixation appeared excellent despite the poor quality of bone remaining. Complications included 3 patients with polar patella fractures postoperatively. Qualitatively, these results compare favorably with patellar resection arthroplasty in this setting.

Stiffness After Total Knee Arthroplasty

BACKGROUNDnStiffness is an uncommon but disabling problem after total knee arthroplasty. The prevalence of stiffness after knee replacement has not been well defined in the literature. In addition, the outcomes of revision surgery for a stiff knee following arthroplasty have not been evaluated in a large series of patients, to our knowledge. The purposes of this study were to define the prevalence of stiffness after primary total knee arthroplasty and to evaluate the efficacy of revision surgery for treatment of the stiffness.nnnMETHODSnWe defined a stiff knee as one having a flexion contracture of 15 degrees and/or <75 degrees of flexion. Two separate groups were evaluated. First, the results of 1000 consecutive primary total knee replacements were reviewed to determine the prevalence of stiffness. Second, the results of fifty-six revisions performed because of stiffness, sometimes associated with pain or component loosening, after primary total knee arthroplasty were evaluated.nnnRESULTSnThe prevalence of stiffness was 1.3%, at an average of thirty-two months postoperatively. The patients with a stiff knee had had significantly less preoperative extension and flexion than did those without a stiff knee (p < 0.0001). There were no significant differences in age, gender, implant design, diagnosis, or the need for lateral release between the patients with and without stiffness. The second cohort, of knees revised because of stiffness, were followed for an average of forty-three months. The mean Knee Society score improved from 38.5 points preoperatively to 86.7 points at the time of follow-up; the mean Knee Society function score, from 40.0 to 58.4 points; and the mean Knee Society pain score, from 15.0 to 46.9 points. The mean flexion contracture decreased from 11.3 degrees to 3.2 degrees , the mean flexion improved from 65.8 degrees to 85.4 degrees , and the mean arc of motion improved from 54.6 degrees to 82.2 degrees . The arc of motion improved in 93% of the knees, and flexion increased in 80%. Extension improved in 63%, and it remained unchanged in 30%.nnnCONCLUSIONSnThe prevalence of stiffness in our series of 1000 primary knee arthroplasties was 1.3%. Revision surgery was a satisfactory treatment option for stiffness, as the Knee Society scores improved, the flexion contractures diminished, and 93% of the knees had an increased arc of motion. However, the results suggest that the benefits are modest.

Predonated autologous blood transfusions after total knee arthroplasty: immediate versus delayed administration.

Efforts to avoid complications associated with transfusion of allogeneic blood have increased the use of preoperatively donated autologous blood (PAB). A major controversy has arisen: Should the same criteria be used for transfusion of autologous as allogeneic red cells? This study prospectively and randomly compared giving PAB immediately after total knee arthroplasty (TKA), beginning in the recovery room or delaying a transfusion until the patients hemoglobin had fallen to less than a 9.0 g/dL transfusion trigger point. The results show that patients who received immediate transfusion had fewer nonsurgical complications (P < .002). Because TKAs are associated with an average blood loss of 1,400 mL, we recommend that PAB be used in the immediate postoperative period, especially in the elderly, in whom the risk for cardiac or nonsurgical complications is inherently increased.

Osteonecrosis of the medial part of the tibial plateau

Fifteen elderly patients (sixteen knees) were seen because of acute pain in the knee and tenderness to palpation over the medial aspect of the tibial plateau. Initially, plain roentgenograms showed a radiolucent area at the site of the tenderness in only nine of the sixteen knees. However, radionuclide bone scans showed focal increased uptake at the site of the tenderness in four of the seven remaining knees, and magnetic resonance images showed discrete areas of low signal intensity at the same site in the other three knees. Plain roentgenograms eventually showed the typical lesion in all knees. Progression of the symptoms led to a total knee arthroplasty in nine knees and to a unicompartmental replacement in three; a satisfactory result was obtained in all twelve knees. An operation was recommended for two other knees, but it was refused by the patients. The symptoms resolved spontaneously in the remaining two knees. A degenerative tear in the medial meniscus, which is a common finding in this age-group, was noted at the time of a later operation in the three knees that had not had a radiolucent area on the initial plain roentgenograms but that had had an area of low signal intensity on the magnetic resonance images. If osteonecrosis of the tibial plateau is not considered as a potential cause of pain in the knee, symptoms may be attributed to a tear in the meniscus and an unnecessary and unproductive arthroscopy may be performed.

Subchondral Magnetic Resonance Imaging Changes in Early Osteoarthrosis Associated With Tibial Osteonecrosis

SUMMARYnThe authors report on 41 patients with acute or subacute knee pain and early or midstage degenerative arthrosis with osteonecrotic lesions in the subchondral and metaphyseal region of the medial proximal tibia. Each lesion was identified only on magnetic resonance images (MRI). These MRI changes are classified and the clinical course is defined during a follow-up period averaging 4.5 years. Radiographically, 22 patients had minimal degenerative changes; 12 had moderate arthritis; and 7 were normal. With MRI, 3 distinct types of lesions were identified. Type A lesions had localized areas of decreased signal in the subchondral area. Type B lesions had diffuse signal changes with extension into the metaphysis. Type C lesions had metaphyseal involvement as well as a marginated serpentine subchondral rim usually associated with advanced osteonecrosis. There were 9 type A lesions, 23 type B, and 9 type C. At the end of 1 year, 33 patients (80%) had no or mild symptoms, and 8 (20%) had persistent moderate pain. At 4.5-year follow-up, most patients had symptoms consistent with progressive osteoarthrosis, 12 patients had severe symptoms (29%), 17 (41%) had mild or moderate symptoms, and only 12 (29%) were asymptomatic or had minimal symptoms. The type of MRI change seen initially was predictive of prognosis. Only 6 (19%) of the 32 patients with type A or B findings had severe symptoms at last follow-up. Six (66%) of the 9 patients with a type C MRI lesion had severe symptoms or had an operation by last follow-up. Twelve patients had follow-up MRI at a mean 15 months (range, 12 to 18 months) after the initial evaluation. The type A and B changes were either absent or significantly reduced. The type C subchondral marginated rim changes remained but metaphyseal involvement was reduced. There appears to be a spectrum of tibial subchondral MRI changes associated with sudden onset of medial knee pain in patients with early osteoarthritis of the knee. These changes may be indicative of osteonecrosis. The initial MRI classification is useful in predicting prognosis. Recognition of this problem may avoid unnecessary intra-articular surgery.

Prevalence and Costs of Rehabilitation and Physical Therapy After Primary TJA

This study evaluated the trends in discharge patterns and the prevalence and cost of post-discharge PT. The 5% Medicare database (1997-2010) was used to identify 50,886 primary THA and 107,675 TKA patients. More than 50% of patients were discharged from hospital to an inpatient facility. There were an increase in discharges to skilled nursing units and a reduced rate to rehabilitation facilities. In contrast to hospital, surgeon reimbursement, and implant costs, the average annual PT cost per patient rose through the study period. Approximately 25% of PT costs were used on less common modalities. PT costs more than

Total knee arthroplasty for steroid-induced osteonecrosis

648 million a year. With the increased pressure to control costs for primary TJA, these patterns may change unless PT effectiveness can be demonstrated.