David G. Nazarian

Extensor mechanism allografts in total knee arthroplasty.

Forty knees in 40 patients who had a chronic extensor mechanism disruption after knee arthroplasty underwent extensor mechanism allograft placement to restore extensor function. Thirteen knees were infected previously and 11 knees did not respond to previous attempts at direct extensor repair or reconstruction. Two patients died and two patients underwent above the knee amputation because of recurrent infection. The final group of 36 patients was studied for a mean followup of 3.6 years (range, 2-10 years). Clinical evaluations were performed using a modified Knee Society scoring system. The average range of motion in the entire group of patients was 1.4 degrees extension to 98 degrees flexion. The average extensor lag was 13 degrees in 15 of 36 patients. There were eight extensor allograft ruptures, which were treated by repeat extensor allograft placement. The average knee scores for function improved from 37 points preoperatively to 68 points postoperatively. Despite these initial ruptures, 34 of 36 patients had a successful clinical result. These results support the use of this technique for complete extensor mechanism loss after knee arthroplasty when direct repair is unfavorable.

Effects of Spinal Instrumentation on Fusion of the Lumbosacral Spine

Study Design This study retrospectively reviewed the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions. The records and radiographs of a group of patients treated by wide decompression and fusion of the lumbosacral spine and by one surgeon were studied. Two treatment groups were identified by fusion technique; one group received autologous bone graft only, and a second group was treated by autologous bone grafting supplemented with pedicle screw fixation. Objectives The two study groups were compared to determine the effects of pedicle screw fixation on lumbosacral fusion for degenerative conditions after wide decompression. Summary of Background Data The reported success rate of lumbar and lumbosacral fusion in the literature is variable. Although several studies have reported high fusion rates with internal fixation, few controlled studies have been published. A critical review of isolated lumbosacral fusions (for degenerative conditions) and the effects of instrumentation is necessary to determine the effectiveness and complications associated with pedicle screw systems in this setting. Methods This study reviewed 215 consecutive patients operated on from 1987 to 1992 for degenerative conditions of the lumbosacral spine. Group 1 included 126 patients who underwent autogenous posterolateral bone graft after decompression. Group 2 included 89 patients treated with Edwards instrumentation and autogenous bone graft. Fusion status was determined via radiographs. Clinical results were based on pain relief after a minimum 2-year follow-up period. Results In Group 1, an overall fusion rate of 65% was obtained. Clinically, 56% had good or excellent results. Complications included pseudarthroses (35%), dural tears (3.2%), and infection (2.4%). In Group 2, a fusion rato of 91% was achieved. In this group, 89% had a good or excellent clinical result. Complications included pseudarthroses (9%), dural tears (2.2%), and infection (2.2%). Conclusions Use of pedicle screw and rod fixation with the Edwards system led to significantly improved results in lumbosacral fusions over autogenous bone graft alone, with a lower complication rate. The use of spinal instrumentation is a valuable adjunct to achieve lumbosacral fusion in patients who have undergone decompressive surgery for the spine.

Arthroscopic treatment of patellar clunk

Excellent results have been reported with posterior stabilized total knee arthroplasty. A common complication relating to patellofemoral articulation is patellar clunk syndrome. Patellar clunk syndrome occurs when a fibrous nodule develops just proximal to the patellar button. At approximately 30 degrees to 45 degrees from full extension, the nodule catches the anterior flange of the femoral prosthesis, resulting in the clunk and a painful range of motion. The present study examines the use of arthroscopic debridement for this disorder. Thirty consecutive patients (32 knees) with the diagnosis of patellar clunk syndrome were evaluated at 1 year after arthroscopic debridement. All patients were evaluated clinically and radiographically according to the Knee Society score. In addition, patients were questioned specifically regarding anterior knee pain and patellofemoral symptoms. Radiographs were evaluated further regarding patella and component position. Patients were diagnosed with patellar clunk at an average of 12 months after their latest knee arthroplasty, with a range of 3 to 47 months. All patients complained of anterior knee pain and the clunk. All patients had a hypertrophic nodule at the junction of the proximal pole of the patella and quadriceps tendon and underwent arthroscopic debridement through a superolateral portal. All patients were free of patellar clunk postoperatively; one patient reported persistent anterior knee pain. Knee Society scores increased from an average of 64 points preoperative to 93 points postoperative. Radiographs showed patella alta in eight knees, patella baja in two. Four femoral components were in 5 degrees flexion. The present study represents the largest collection of data regarding patellar clunk syndrome. The data appear to support arthroscopic debridement as a successful treatment of patellar clunk syndrome.

Preoperative use of recombinant human erythropoietin before total joint arthroplasty.

BACKGROUND Previous reports have suggested that the use of recombinant human erythropoietin is effective for decreasing the need for perioperative allogeneic blood transfusion. The purpose of this study was to evaluate the efficacy of erythropoietin in combination with, and compared with, preoperative autologous donation for reducing allogeneic blood requirements for total joint arthroplasty. METHODS Two hundred and forty patients undergoing primary and revision total hip or knee arthroplasty were enrolled into three groups with different treatment regimens: (1) erythropoietin and preoperative autologous donation (Group 1), (2) erythropoietin alone (Group 2), and (3) preoperative autologous donation alone (Group 3). Patients were evaluated with regard to requirements for allogeneic transfusion, change from the baseline to the lowest postoperative hemoglobin value, postoperative complications, and adverse reactions. RESULTS The rate of allogeneic transfusion was 11% in Group 1 (erythropoietin and preoperative autologous donation) compared with 28% in Group 2 (erythropoietin alone) and 33% in Group 3 (preoperative autologous donation alone). Within Group 1, patients who had a unilateral primary arthroplasty had an allogeneic transfusion rate of 4% and those who had a bilateral or revision arthroplasty had an allogeneic transfusion rate of 17%. In Groups 2 and 3, the allogeneic transfusion rates were 14% and 15%, respectively, for the patients who had a unilateral primary arthroplasty and 35% and 47%, respectively, for those who had a bilateral or revision arthroplasty. CONCLUSIONS Preoperative use of erythropoietin in conjunction with preoperative autologous donation reduces the need for allogeneic blood transfusion associated with total joint arthroplasty more effectively than does either erythropoietin or preoperative autologous donation alone.

A two-stage approach to primary knee arthroplasty in the infected arthritic knee.

Fourteen patients with either septic knee arthritis or osteomyelitis of the knee with marked joint destruction were treated by resection arthroplasty with the introduction of an antibiotic cement spacer block, appropriate antibiotic therapy, and subsequent primary total knee arthroplasty. Most patients with septic arthritis had chronic infection. Eight patients had positive cultures preoperatively; the remaining patients had either a culture negative purulent aspiration or diagnostic radiographic studies. All patients underwent reconstruction with primary total knee arthroplasty on an average of 3.1 months after the initial stage procedure. Knee Society scores progressed from 46 preoperatively to 89 postoperatively, with an average range of motion from 3 degrees to 105 degrees. At latest clinical follow-up (average, 4.5 years), no patients had recurrence of infection. These data suggest that this method is successful in treating chronically infected knees with a 2-staged arthroplasty.

Outcomes of total hip arthroplasty are similar for patients with displaced femoral neck fractures and osteoarthritis.

This study attempted to evaluate whether total hip arthroplasty for displaced femoral neck fractures had significantly different outcomes when compared with total hip arthroplasty for osteoarthritis. This is a retrospective study of 60 patients who had total hip arthroplasties between 1997 and 2001. Thirty patients (mean age, 79.7 years) had total hip arthroplasties for displaced femoral neck fractures; 30 patients (mean age, 76.9 years) were treated with total hip arthroplasties for osteoarthritis. The same surgeon used the modified lateral approach for all surgeries. All patients had radiographic assessment, physical examination, and evaluation with the Harris hip score. The mean followup was 38 months. The mean Harris hip score for the 25 patients treated with a total hip arthroplasty for a femoral neck fracture was 81 points; the mean hip score for the 27 patients treated with a total hip arthroplasty for osteoarthritis was 87 points. No statistically significant differences between these groups were observed. Patients who were treated with a total hip arthroplasty for a femoral neck fracture did not have increased perioperative morbidity compared with patients who had a total hip arthroplasty for osteoarthritis. This study suggests that the outcomes for total hip arthroplasties in this consecutive series of patients treated for displaced femoral neck fractures and osteoarthritis are comparable.

A comparison of stemmed and unstemmed components in revision knee arthroplasty.

The purpose of the current study was to compare retrospectively the results of the Insall-Burstein constrained condylar knee implant used with and without intramedullary stems in 207 revision knee arthroplasties with the Insall-Burstein constrained condylar knee implant. One hundred sixty-one knees had either one or two stems placed. One hundred eight femoral stems and 76 tibial stems were placed. Fifty-five knees had no femoral or tibial stem. The average knee scores ranged from 52 preoperatively to 86 postoperatively. The average range of motion postoperatively was 4° (range, 0°–10°) to 106° (range, 94°–118°) in this group. The average postoperative knee score was 86 in the unstemmed group and 85 in the stemmed group with no difference in average range of motion. There were four (3%) cases of tibial loosening and two (2%) cases of femoral loosening in the unstemmed group. There were two (2%) cases of tibial loosening and two (2%) cases of femoral loosening at an average followup of 4.2 years (range, 2–6.2 years). Despite the higher constraint inherently designed in an Insall-Burstein constrained condylar knee component, the current study did not show a significantly higher loosening in implants without stems compared with implants used with stems. Therefore, the use of a semiconstrained component does not alone constitute a requirement for the use of an intramedullary stem.

Intraoperative pacemaker dysfunction caused by the use of electrocautery during a total hip arthroplasty

Pacemaker dysfunction encountered during orthopedic procedures is a rare but potentially life-threatening complication. With an increasing number of orthopedic procedures performed on the aging population, it is not uncommon to encounter patients with pacemakers requiring major orthopedic intervention. Most, if not all, major orthopedic procedures performed today require the use of electrocautery for hemostasis. In this article we review the literature for pacemaker complications and report a case of pacemaker failure after a single use of the unipolar electrocautery on a patient undergoing a total hip replacement.

Adoption of information technology by resident physicians.

The Internet represents a technological revolution that is transforming our society. In the healthcare industry, physicians have been typified as slow adopters of information technology. However, young physicians, having been raised in a computer-prevalent society, may be more likely to embrace technology. We attempt to characterize the use and acceptance of the Internet and information technology among resident physicians in a large academic medical center and to assess concerns regarding privacy, security, and credibility of information on the Internet. A 41-question survey was distributed to 150 pediatric, medical, and surgical residents at an urban, academic medical center. One hundred thirty-five residents completed the survey (response rate of 90%). Responses were evaluated and statistical analysis was done. The majority of resident physicians in our survey have adopted the tools of information technology. Ninety-eight percent used the Internet and 96% use e-mail. Two-thirds of the respondents used the Internet for healthcare-related purposes and a similar percentage thought that the Internet has affected their practice of medicine positively. The majority of residents thought that Internet healthcare services such as electronic medical records, peer-support websites, and remote patient monitoring would be beneficial for the healthcare industry. However, they are concerned about the credibility, privacy, and security of health and medical information online. The majority of resident physicians in our institution use Internet and information technology in their practice of medicine. Most think that the Internet will continue to have a beneficial role in the healthcare industry.

Haemophilus influenza infection complicating a total knee arthroplasty.

Haemophilus influenza is rarely a cause of septic arthritis in adults. It has not been reported as a cause of infection in total knee arthroplasties. Haemophilus influenza septic arthritis is a late stage, hematogenous infection. A 43-year-old woman with a history of rheumatoid arthritis was found to have Haemophilus influenza infection 3 years after the index total knee arthroplasty. The patient was treated with debridement and systemic antibiotics. At the 5-year followup, the patient was comfortable and free of clinical signs of infection. This approach was successful at eradicating infection and salvaging the total knee arthroplasty.