Section on orthopaedic & trauma surgery. (Abstracts of Scientific Posters).

ORT1. YOUNG PATIENTS WITH PRIMARY THA AND ACTIVITY LEVEL AT MINIMUM EWE-YEAR FOLLOW-UP. VF Sechriest, MD, JD Spates, D Marek, M Kuskowski, PhD, KJ Saleh, MD, RM Gustilo, MD, and RF Kyle, MD. Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN.

Young patients with total hip arthroplasty (THA) are considered at risk for early prosthetic failure due to greater physical demands on the implant. The purpose of this study was: 1) to quantify activity level in young patients after THA; and 2) to analyze relationships between activity level and age, body mass index (BMI), Harris Hip Score (HHS), and radiographic wear. Forty uncemented THAs in 32 patients (mean age, 41 years) were evaluated after an average of 6.1 years. BMI and HHS for pain and function were recorded. Walking activity was measured using a digital pedometer to record gait cycles. Patients completed a 10-point UCLA activity questionnaire. Polyethylene linear wear rate was measured. Pearson correlation coefficients were calculated. Gait cycles/year averaged 1.2 million (range, 0.3 to 2.7 million). Mean UCLA activity score was 6, and mean HHS was 77. Mean wear rate was 0.17 mm/yr (range, 0.03 to 0.38 mm/yr). Increased BMI and age were correlated with decreased gait cycles/year. HHS correlated positively with UCLA activity score. Wear rate did not correlate with either measure of activity. In this young population, the mean gait cycles/year and UCLA activity score are consistent with what has been reported in older populations after THA. Likewise, the negative influence of age and relative obesity on activity is consistent. Although HHS did correlate with the UCLA activity score, it did not correlate with gait cycles/year. Interestingly, although joint use is thought to contribute to polyethylene wear, no direct relationship between linear wear and activity was demonstrated.

ORT2. TREATMENT OF UNSTABLE PROXIMAL TIBIA FRACTURES WITH A LATERAL FIXED-ANGLE PLATE. William M. Ricci, MD,Jonas R. Rudzki, MD, MS, and Joseph Borrelli, Jr. MD. Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO.

Axially unstable proximal tibia fractures including bicondylar tibial plateau (41C) and comminuted metaphyseal fractures (41A) present a difficult treatment challenge. Techniques of open reduction with intemal fixation (ORIF) employing a traditional lateral plate and screw construct offer littie resistance to varus deformity. Augmentation of such constructs with either a medial plate or medial external fixation has been advocated to improve stability. These methods increase associated morbidity and have the potential to devitalize bone, particularly with exposure obtained through a single midline incision. Hybrid external fixation for these injuries is associated with malunion, pin-tract complications, decreased knee range of motion, and poor patient satisfaction. The purpose of this investigation was to examine the results of using a single, lateral, fixed-angle plate construct for treatment of patients with axially unstable proximal tibia fractures in a prospective, nonrandomized study with respect to heali ng and ability to maintain alignment. Twenty-three patients admitted to our level I trauma center between November 1998 and October 2000 treated with a lateral fixed angle plate (Less-Invasive Stabilization System [LISS] plate, Synthes, Paoli, PA) for either a bicondylar tibial plateau fracture (41C) (n = 12) or a comminuted proximal tibial metaphyseal fracture (41A) (n = 11) were identified from our orthopaedic trauma database. There were 12 men and 11 women with an average age of 57 years (range, 23-84 years). Eighteen of the fractures were closed and five were open (2 - grade I, 1 - grade II, 2 - grade LILA). One patient died due to a head injury and one patient was lost to follow-up. The remaining 21 patients were followed up at regular intervals. Anterior-posterior and lateral radiographs obtained postoperatively and at follow-up visits were used to determine fracture alignment. Malalignment was defined as greater than five degrees of angular deformity. Nonunion was defined as an absence of progressive f racture healing over three consecutive months. At an average follow-up of 33 weeks (range, 20104 weeks), the fractures of all patients had healed. Based on immediate postoperative radiographs, 3 patients had malaligument in the coronal plane (2 valgus, 1 varus) and 5 had malalignment in the sagittal plane (2 flexed, 3 extended). The average coronal plane deformity was 3.7[degrees] (range, 6[degrees] varus to 7[degrees] valgus). The average sagittal plane deformity was 3.5[degrees] (range, 9[degrees] flexion to 11[degrees] extension). At the last follow-up examination, no patient had a change in their fracture alignment. One patient required hardware removal for loosening, and the fracture subsequently healed without further surgery. There were no infections. Two patients developed postoperative compartment syndromes treated successfully with fasciotomy. In this series, a lateral fixed-angle plate construct for internal fixation of bicondylar tibial plateau (41C) and comminuted metaphyseal (41A) fractures of t he proximal tibia resulted in a 100% union rate without loss of reduction and with few complications. This construct obviates the need for adjuvant medial stabilization for axially unstable proximal tibia fractures treated with ORIF, and appears to be a better option than external fixation.

ORT3. SURGICAL TECHNIQUE: DISTENTION ARTHROGRAPHY FOR SAFE EXTRACAPSULAR PLACEMENT OF PROXIMAL TIBIAL TRANSFIXATION PINS. Jorge A. Fabregas, MD, and Stanley P. Michael, MD. Department of Orthopaedic Surgery. Temple University Hospital, Philadelphia, PA.

The association between septic arthritis and the use of external fixators for proximal tibial fractures has been well established. Intracapsular placement of pins, as well as sepsis tracking along pin tracks and fresh fracture lines, has been implicated in the development of pyarthrosis. Several methods have been described to assure extracapsular placement of transfixation pins. Safe pin placement location has been recommended based on prior cadaveric dissections and MRI measurements. Variability among capsular extension between subjects makes relying solely on these recommendations unreliable. Prior to the placement of proximal tibia pins, the knee joint in insufflated with enough diluted radiographic contrast to achieve maximal capsular distension. Intraoperative fluoroscopic visualization of the capsule extension is then performed prior to pin transfixation. The distal reflection of the capsule is thoroughly visualized during full range of knee motion using multiplanar imaging and can be easily avoided usi ng this method. This technique has utility in the trauma setting during the placement of hybrid external fixators, but also in the pediatric arena to ensure safe placement of Ilizarov or other external fixators.

ORT5. INTRAOPERATIVE NEUROPHYSIOLOGIC MONITORING DURING SCOLIOSIS SURGERY USING MOTOR EVOKED POTENTIALS. Iris Yaron, MD, Klaus Novak, MD, Adauri Bueno de Gamargo, MD, Vedran Deletis, MD, PhD, and Michael Neuwirth, MD. Beth Israel Medical Center, Albert Einstein College of Medicine, New York, NY

Because paraplegia has been reported with preserved somatosensory evoked potentials (SEP), SEP monitoring of the spinal cord during surgical correction of scoliosis has been proven unreliable. Data strongly suggest that adding motor evoked potential (MEP) monitoring can be more reliable than SEP monitoring alone. To assess the safety and efficacy of multimodal evoked potential monitoring during scoliosis surgery, 23 patients with average age of 13.5 years who had scoliosis surgery between August 2000 and February 2002 were included in this study. Twenty of 23 patients had idiopathic scoliosis, 2/23 had neuromuscular scoliosis, and 1/23 had congenital scoliosis. Epidural MEPs (eMEPs) were recorded from catheter electrodes inserted into the epidural space at the upper and lower levels of the exposed spine. Muscle MEPs (mMEPs) were recorded from limb muscles. MEPs were elicited with a single stimulus for eMEP and with a short train of 5 to 7 stimuli for mMEP monitoring. SEPs were monitored from the scalp after s timulation of median and posterior tibial nerves. Twenty-two of 23 patients had monitorable eMEP, mMEP, and SEP responses during surgery. The nonmonitorable patient had advanced form of Friedreich's ataxia. No changes were observed in mMEP monitoring. One patient showed a 40% reduction in eMEP amplitude during corrective maneuvers, but the amplitude was recovered after reduction of corrective forces. One patient showed a temporary, significant reduction of SEP amplitude, which improved after correction of hypotension. An average correction of scoliosis of 60% was achieved by posterior spinal fusion (n 18) or combined anterior and posterior fusion (n = 5). No patient experienced postoperative neurologic deficit. Multimodal monitoring is a reliable and safe method of monitoring spinal cord functional integrity during surgical correction of scoliosis. eMEP may be more sensitive to damage of the spinal cord than other methods.

ORT6. AN MBA: THE UTILITY AND EFFECT ON PHYSICIANS' CAREERS. Selene G. Parekh, MD, MBA, Dokleida Sava, MD, MPH, Dipti Sahoo, BA, and Rakesh DonthineniRao, MD. The Wharton School of Business, Small Business and Development Center, and the Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA

Due to increased economic, legislative, legal, and administrative pressures, physicians are becoming increasingly disenchanted with the practice of medicine. As a result, many physicians are seeking alternative career paths, some even enrolling in business school. A survey was distributed to 161 physician MBAs to evaluate the utility of an MBA degree and how it has changed their career paths. We found that a significant amount of time was redistributed from patient care to administration. We also discovered that the primary motivator was to learn the business aspects of the health care system. In order for physicians to overcome the multifaceted challenges of the evolving health care system, it will be essential to continue training a percentage of physicians in both medicine and business. The health care industry has received a lot of attention with regard to the quality, the efficiency, and the access to health care services. Increasingly stringent economic, legislative, legal, and administrative constraint s have led to physician dissatisfaction and low morale. As a result, many physicians are seeking alternative career paths, including the enrollment in a Masters in Business Administration program. In this study, we evaluate the utility of an MBA degree and how it has changed the career paths of practicing physicians. A 27-question survey was distributed to 161 physician MBA graduates of 3 East Coast business schools. Results were evaluated and statistical analysis performed. Of the 87 (RR=54%) respondents, the average age was 41.4 years. Sixty-six (83.5%) completed a residency program. On average, physicians completed their MBAs 8.64 years after graduating from medical school. The major motivations included learning the business aspects of the health care system (n = 53; 67.1%) and obtaining a more interesting job (n = 41; 51.9%). Evaluating operations and implementing improvements (n = 39; 49.4%); learning how to be an effective leader (n = 35; 44.3%); comprehending financial principles (n = 33; 41.8%); work ing within a team (n = 27; 34.2%); and negotiating effectively (n = 25, 31.6%) were the most pertinent skills acquired. The pre- and post-MBA division of time for health-care-related activities was: 58.3% vs 31.8% (P < .001) for patient care, 8.5% vs 3.68%] (P < .001) for teaching, 4.57% vs 1.46% (P .11) for basic science research, 4.23% vs 4.55% (P = .90) for clinical research, and 11.8% vs 33.5% (p < .001) for administration. 81% (n 64) of physician MBAs feel that their business degree has been very useful or essential in the advancement of their careers. Physicians practice patterns significantly change after completing an MBA, reflecting more of an administrative role. In order for physicians to overcome the multifaceted challenges of the evolving health care system, it will be essential to continue training a percentage of physicians in both medicine and business.

ORT7. ANTIBIOTIC-IMPREGNATED CEMENT RODS IN THE TREATMENT OF LONG BONE INFECTIONS. Mark Anders, MD, and Daniel Schlatterer, DO, MS. Department of Orthopaedic Surgery, SUNY at Buffalo and Erie County Medical Center, Buffalo, NY

This retrospective study evaluates the outcome of 10 infections treated with an antibiotic cement rod. Average followup is 24 months (range, 15 to 52 months). Four femurs, four tibias, and two humeri were involved. Initial fracture management included intramedullary rodding, plating, or external fixation. Seven of 10 fractures were open, with 1 Gustillo grade IIIC. Eight of 10 fractures developed nonunions. Infection management was initiated an average 8.9 months after injury. It included hardware removal, debridement, and placement of an intramedullary antibiotic cement rod. Intraoperative antibiotic rod fabrication requires a metal rod, a chest tube, cement, and antibiotics (vancomycin, tobramycin, and gentamicin). The antibiotic rod was removed an average of 8 weeks post- placement. Definitive fixation was then performed. This ranged from exchange rodding, plating, and externalfixation. Charts were reviewed for coexisting injuries, patient comorbidities, intraoperative wound cultures, and peri/postoperativ e antibiotic regimens. Staphylococcus aureus was the most common pathogen from intraoperative wound cultures. Cultures from 5 patients grew mixed organisms, including Pseudomonas, Bacteroides, and Enterococcus species. All fractures showed bone union at an average of 14 weeks from time of definitive fixation. Two patients have demonstrated infection recurrence. One patient with rheumatoid arthritis and daily prednisone therapy developed infected total-elbow arthroplasties. The total elbows were completed before the femur fracture. Removal of all hardware in this patient resulted in subsequent resolution of all infections. The second patient's culture grew Bacteroides and Enterococcus species from the femur. This patient suffered significant soft tissue damage including an ipsilateral traumatic below-the-knee amputation at the time of injury. This simple, inexpensive adjunct to debridement and temporary stabilization of long-bone infections resulted in the resolution of 9 of 10 post-traumatic long-bone infecti ons. Patients with comorbidities may require additional surgical and/or medical interventions. Further study including longer follow-up, a larger patient population, and newer antibiotic treatments that are active against resistant organism strains are warranted.

ORT8. PERIPROSTHETIC SURPACONDYLAR FEMUR FRACTURES FOLLOWING TOTAL KNEE ARTHROPLASTY Hari P. Bezwada, MD. Philadelphia, PA.

Periprosthetic supracondylar femur fractures following total knee arthroplasty (TKA) are an infrequent but devastating complication. They may require extensive treatment and leave the patients with less desirable functional results. The purpose of this study is to review our experience using both intramedullary fixation and traditional open reduction and internal fixation techniques for managing this complication. From 1996 to 2000, thirty surpacondylar femur fractures were treated at our institutions. The time following index arthroplasty ranged from 1 to 15 years. Eighteen fractures occurred in prosthetic designs that contained an open box that accomodated retrograde intramedullary rod fixation (FIMR). Twelve fractures required traditional open reduction with internal fixation (ORIF) because of closed boxes or distal fracture patterns. Adjunctive bone cement was used in two cases to supplement fixation. Postoperative range of motion, alignment, Knee Society knee scores, and complications were recorded. Post operative follow-up time averaged 3 years (range, 2-4 years). Average range of motion was 5 to 100 degrees for those who underwent FIMR, and 5 to 95 degrees for those with ORIF. Residual alignment at last follow-up was 4 degrees of valgus for the FIMR group and 5 degrees of valgus for the ORIF group. Knee Society knee scores were 84 and 82, respectively, at last follow-up. None of the patients required revision arthroplasty. Complications included one nonunion with varus alignment. Supracondylar femur fractures following TEA remain a challenging and difficult problem. For those designs that can accommodate it, FIMR appears to be the treatment of choice. However, traditional ORIF may also yield satisfactory results in those designs that do not allow retrograde FIMR fixation.

ORT9. ANALYSIS OF PEDICLE AND TRANSLAMINAR FACET FIXATION IN A MULTISEGMENT INTERBODY FUSION MODEL. Dahari Brooks, MD. Syracuse, NY

The role of lumbar pedicle screws varies with the technique of lumbar fusion. Specifically, interbody fusion technique transfers the pedicle screw from a load-bearing to a load-sharing device. The purpose of our study was to investigate the significance of the middle segment pedicle screws in a two-level interbody fusion model and examine translaminar screw fixation as an alternative to pedicle screw fixation in this two level interbody fusion model. Six lumbar (L1-L5) human cadaver specimens were nondestructively tested intact in flexion, extension, and torsion. Overall range of motion (ROM) and stiffness was measured, and tilt sensors were mounted at L2 and L4 to examine individual lumbar motion. Each specimen then underwent a two-level interbody fusion with anterior femoral ring allograft and posterior fixation. There were three types of posterior fixation: group I, rods with pedicle screws at three levels; group II, rods with pedicle screws at two levels; and group III, translaminar facet screws. Biomechanical testing was repeated for each group. The overall ROM (L1-L5) significantly decreased after the interbody fusion in comparison with the intact condition for torsion and flexion (P < .05). There were no significant differences in construct stiffness for torsion, but there were significant differences when comparing intact with the three groups for both flexion and extension (P < .05). ROM at L2 and L4 was significantly less for all groups in comparison with the intact condition (P < .05). For all parameters, there were no significant differences between the groups, but group I did show the largest changes. This study supports the omission of middle segment screws in a two-level interbody fusion model. In addition, translaminar screws are similar biomechanically to pedicle fixation in a two-level interbody lumbar fusion.

ORT10. INTRA-ARTICULAR MORPHINE FOR POSTARTHROSCOPIC KNEE PAIN CONTROL: A PROSPECTIVE STUDY. Sajeev K. Nair, MD. Arlington, VA.

Reports on pain relief after arthroscopic procedures with intra-articular morphine and bupivocaine are conflicting. While some authors (eg, Stein et al, Joshi et al) have reported that analgesic effects of intra-articular morpine lasted 24 hours, others (eg, Ruwe et al, Here et al, Muerhen et al) found no advantage in using morphine over using bupivocaine. After reviewing the conflicting results, we performed an initial pilot study using morphine and bupivocaine, and found very encouraging results with the administration of morphine. Hence, we have performed a prospective study giving increased dose of morphine to improve its efficacy in controlling knee pain. Forty patients undergoing arthroscopic surgery of the knee were selected. Patient age ranged from 30 to 60 years. All were free from alcohol and drug abuse, and none had more than one arthroscopic surgery in the past. After the procedure, 4 mg of morphine in 25 cc of saline was injected intra-articularly. Tourniquet was not used for the procedure. The o nly drugs given for pain relief after surgery were oxycodon (5 mg) + acetaminophen (325 mg). Visual analog scale (0-10) was provided to record pain at 1, 4, 8, 12, 24, and 48 hours after surgery. The number of doses of oxycodon taken during that 48 hours was also recorded. Pain was classified as mild, moderate, or severe at 1, 4, 8, 12, 24, and 48 hours. The majority of patients had mild pain during the 48-hour period. Twenty-three patients had taken one or more doses of oxycodon during various intervals (cumulative dose, 38). Lower pain scores and least supplemental medication usage were recorded at 4, 24, and 48 hours. None of the patients recorded severe pain at 48 hours. Intra-articular opioids are absorbed very slowly into the systemic circulation because of their hydrophilic property. We have used a higher dose of morphine (4 mg) and found that effective knee pain control can be achieved for as long as 48 hours. This is explained by the dose-dependent response of opioid therapy. Since oxycodon has a dur ation of action of 6 hours, the prolonged 48-hour analgesic effect of morphine could not be caused by oxycodon for those who took the medication. We have also found that the early effect and duration of action of morphine in relieving knee pain is significantly better than bupivocaine when compared with our pilot study group.