Faculty Bibliography

Hip arthroplasty has become the standard treatment of end-stage osteoarthritis. However, postoperative complications are the risks associated with joint arthroplasty, which most significantly impact patient results and the total cost of care. Currently, no predictive system has been developed for categorizing levels of risk for the development of postoperative complications in patients undergoing total hip arthroplasty. We examined the association between the medical clearance risk rating by the physician performing the preoperative clearance examination and postoperative complications after total hip arthroplasty. We have demonstrated a significant association between the medical clearance risk rating and postoperative urinary track infection, and the American Society of Anesthesiologist score but no significant association to other complications. This study presents a predictive patient characteristic that may help us identify among our patients the ones that may benefit from a personally tailored preoperative planning and evaluation but demonstrates further work is necessary to better predict the risk of complications after total hip arthroplasty

Stem cell application is a burgeoning field of medicine that is likely to influence the future of orthopaedic surgery. Stem cells are associated with great promise and great controversy. For the orthopaedic surgeon, stem cells may change the way that orthopaedic surgery is practiced and the overall approach of the treatment of musculoskeletal disease. Stem cells may change the field of orthopaedics from a field dominated by surgical replacements and reconstructions to a field of regeneration and prevention. This review will introduce the basic concepts of stem cells pertinent to the orthopaedic surgeon and proceed with a more in depth discussion of current developments in the study of stem cells in fracture healing

Soft tissue balancing during total knee arthroplasty (TKA) has a direct affect on patello-femoral tracking and knee range of motion, which are necessary for a well functioning TKA postoperatively. We report on the use of an electronic pressure sensing instrument for soft tissue balancing of the knee before completion of all intraoperative bone cuts, as a way to improve patellar tracking. In a retrospective study of 99 consecutive TKAs, with intraoperative electronic instrument guided soft tissue balancing performed, a reduction in the incidence of lateral patellar retinacular release was found, as compared with the 100 consecutive TKAs prior to its use (5.5% v 12%, respectively). Electronic measurement of soft tissue balancing during TKA reduced the need for lateral patellar retinacular release.

A fracture construct, representing a worst-case model of a comminuted intertrochanteric fracture, was created in order to compare the fixation stability of two different cephalomedullary nails: one where the lag screw can telescope within itself to achieve displacement of the head-neck fragment, and the other where the solid lag screw slides only. After nail fixation, the models were loaded and then cycled, and positions of the head-neck fragment and lag screw were determined. Both nails similarly acted to limit motion of the head-neck fragment by the sliding of their lag screws, causing impingement of the fragment against the nail. Fragment movement was achieved with significantly less force with the telescoping lag screws, which also showed no final lateral projection from the nail. This was in contrast to the solid lag screws that demonstrated lateral projection in all cases.

Hip resurfacing arthroplasty has been developed as an alternative to traditional total hip arthroplasty, in an effort to minimize the loss of native bone in young patients with symptomatic hip osteoarthritis. Femoral neck fracture following hip resurfacing is a unique complication; several risk factors are associated with this complication, including female gender. In the present study, we used finite element models of the proximal femur to simulate stresses across the femoral neck in pelvis models with varying widths. This analysis demonstrated an increase in hip reaction forces as the width of the pelvis increases, a condition that simulates a resurfacing condition in a female pelvis. This difference in peak stress on the femoral neck may explain the increased incidence of femoral neck fractures seen in female patients following hip resurfacing.

Orthopaedic patients with poor nutritional status are at an increased risk of postoperative complications, such as infection and wound healing. Nasal colonization with Staphylococcus aureus, especially with methicillin-resistant Staphylococcus aureus, has been shown to be a risk factor for surgical-site infections. We examined the incidence of nutritional depletion in our arthroplasty population and its correlation with Staphylococcus aureus colonization. We conducted a retrospective review of prospectively collected data of our arthroplasty patient population. Patients with known Staphylococcus aureus colonization or surgical-site infection were compared with a random cohort of patients. Patient demographics, preoperative nasal culture, and two nutritional screening scores were collected. Six hundred and fifty-two patients underwent arthroplasty and completed preoperative nasal cultures and nutritional assessment. A high percentage (27%) of our patients demonstrated some level of nutritional depletion prior to joint replacement. Overall nutritional scores were not significantly associated with surgery-type, preoperative nasal culture, or surgical- site infection in our patient population.

The diagnostic value of the vacuum phenomenon between the femoral head and the acetabulum, and time frame of its occurrence after application of traction is an important clinical question. The resulting arthrogram may outline the shape, location, and extent of cartilage lesions prior to arthroscopy of the hip joint. The presence, duration, and diagnostic information of the vacuum phenomenon were evaluated in 24 hips that underwent arthroscopy. The operative diagnosis was compared to the results of imaging studies and to findings obtained during a traction trial prior to arthroscopy. Indications for arthroscopy included avascular necrosis, labral tears, loose bodies, osteoarthrosis, and intractable hip pain. In 22 hips the vacuum phenomenon developed within 30 seconds after application of traction. The most important data obtained from the vacuum phenomenon was the location and extent of femoral head articular cartilage detachment and the presence of nonossified loose bodies. The vacuum phenomenon did not reveal labral or acetabular cartilage pathology in any of these patients. The vacuum phenomenon obtained during the trial of traction can add valuable information prior to hip arthroscopy. Femoral head articular cartilage detachment was best documented by this method. The hip arthroscopist should utilize this diagnostic window routinely prior to hip arthroscopy.

INTRODUCTION: Wrong-site surgery is defined as an operation conducted at the wrong site, on the wrong person, or resulting in the wrong procedure. Since 1993, more than 2200 wrong-site surgeries have been reported by the National Practitioner Data Base. A 2005 survey reported, 5.6% of replying academy fellows encountered a wrong-site surgery incident. Multiple interventions have been since suggested for prevention of these occurrences by the American Academy of Orthopaedic Surgeons and Joint Commission on Accreditation of Healthcare Organizations. MATERIALS AND METHODS: This institutional review board-approved study was conducted to investigate patient compliance and reliability in marking the surgical site. Two hundred patients undergoing orthopedic surgery who agreed to participate were enrolled at the time of preoperative testing and clearance for surgery. The patients received instructions to mark the surgical site with a 'YES.' Patient data collected included age, sex, procedure type and location, history of previous orthopedic surgeries, workmen's compensation status or motor vehicle collision involvement, employment status, primary language, level of education, presence of depression or toxic habits, and the time between enrollment and day of surgery. RESULTS: We achieved an overall compliance rate of 68.2%. There was no difference with respect to sex, tobacco use or history of depression, level of education or occupation, workmen's compensation, or government insurance status. The mean age of compliant patients was 48.6 years versus 53.3 years for those who did not comply (P = 0.05). About 72% of those who spoke English as a primary language complied, as opposed to 49% in others (P = 0.009). The time between enrollment and surgery was 10.4 days in compliant patients versus 23.1 days in noncompliant patients (P = 0.05). No statistically significant difference was noted with all other variables recorded. In no instance did patients mark the wrong side or make any marks likely to contribute to the wrong operation. CONCLUSIONS: Patient's ability to be involved in this preventative measure is independent of most demographic variables previously thought to be significant. However, in view of the 68.2% compliance, patient involvement in surgical site marking is unreliable and may not help in decreasing the chances of wrong-site surgery

BACKGROUND: Patellar tendinitis is one of the several differential diagnosis of anterior knee pain. The clinical diagnosis of patellar tendinitis is based on tenderness to palpation at the inferior pole of the patella. The tenderness has been noted to be maximal when the knee is extended and the quadriceps relaxed, but a definite clinical sign for diagnosis is lacking. The accuracy of two clinical signs was assesed by a two-stage study which included physical examination, MRI and a cadaveric study. MATERIALS AND METHODS: Two clinical signs, the "passive flexion-extension sign" and the "standing active quadriceps sign" were assessed in 10 consecutive patients with presumed patellar tendinitis. Five patients had an MRI, showed focal abnormality in the tendon. The location of the MRI finding corresponded, to the region of maximal tenderness. A cadaveric dissection was undertaken to describe the anatomy of the patella and the patellar tendon during these tests. RESULTS: Both tests showed a significant decrease in tenderness at the area of inflammation when the patellar tendon was under tension. The cadaveric dissection showed that when the knee is flexed to 90 degrees or when the quadriceps is tensioned the deep fibers of the tendon do not deform to anteriorly applied pressure. CONCLUSION: We suggest using these studies routinely in the evaluation of patients with anterior knee pain.

BACKGROUND: Methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus surgical site infections are an increasing health problem in the United States. To date, no study, as far as we know, has evaluated the prevalence of Staphylococcus aureus colonization in orthopaedic surgeons. The purpose of our study was to assess the prevalence of methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus colonization in orthopaedic surgery attending surgeons and residents at our institution compared with that in our high-risk patients. METHODS: We performed nasal swab cultures in seventy-four orthopaedic attending surgeons and sixty-one orthopaedic surgery residents at our institution, screening for methicillin-resistant Staphylococcus aureus and methicillin-sensitive Staphylococcus aureus. We compared these results with a prospective database of nasal cultures of patients undergoing joint replacement and spine surgery. RESULTS: A total of 135 physicians were screened. Of those physicians, 1.5% were positive for methicillin-resistant Staphylococcus aureus and 35.7% were positive for methicillin-sensitive Staphylococcus aureus. None of the sixty-one residents were positive for methicillin-resistant Staphylococcus aureus. However, 59% were positive for methicillin-sensitive Staphylococcus aureus. Of the seventy-four attending surgeons, 2.7% were positive for methicillin-resistant Staphylococcus aureus and 23.3%, for methicillin-sensitive Staphylococcus aureus. Previous studies at our institution have demonstrated a 2.17% prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus and an 18% rate of methicillin-sensitive Staphylococcus aureus in high-risk patients. Thus, no difference was found between the prevalence of methicillin-resistant Staphylococcus aureus in residents or attending surgeons and that in the high-risk patients. However, the prevalence of methicillin-sensitive Staphylococcus aureus colonization in the surgeons (35.7%) was significantly higher than that in the high-risk patient group (18%) (p < 0.01). CONCLUSIONS: At a major teaching hospital, a higher prevalence of methicillin-sensitive Staphylococcus aureus colonization was found among attending and resident orthopaedic surgeons compared with a high-risk patient group, but the prevalence of methicillin-resistant Staphylococcus aureus colonization was similar