Faculty Bibliography

Rising implant prices and evolving technologies are important factors contributing to the increased cost of arthroplasty. Assessing how patients value arthroplasty, new technologies, and their perceived outcomes is critical in planning cost-effective care, as well as evaluating new-technologies. One hundred one patients undergoing arthroplasty took part in the survey. We captured demographics, spending practices, knowledge of implants, patient willingness to pay for implants, and preferences related to implant attributes. When patients were asked if they would be satisfied with "standard of care" prosthesis, 80% replied "no". When asked if they would pay for a higher than "standard of care" prosthesis, 86% replied "yes". The study demonstrated that patients, regardless of their socio-economic status, are not satisfied with standard of care implants when newer technologies are available, and they may be willing to share in the cost of their prosthesis. Patients also prefer the option to choose what they perceive to be a higher quality or innovative implant even if the "out of pocket" cost is higher.

Knee malalignment during total knee arthroplasty (TKA) is commonly classified as either varus or valgus on the basis of a standing anteroposterior radiograph. Computer-assisted surgery (CAS) navigation TKA provides precise dynamic evaluation of knee alignment throughout the full range of motion (FROM). The goal of this study was to classify patterns of CAS-generated knee deformity curves that match specific soft tissue contracture combinations. This can then be applied as an algorithm for soft tissue balancing on the basis of the preoperative knee deformity curve. Computer navigation-generated graphs from 65 consecutive TKA procedures performed by a single surgeon were analyzed. A stress-strain curve of the coronal alignment of the knee was recorded throughout FROM before bony resection. All graphs were classified into groups according to their pattern. Cadaveric knee models were then used to test the correlation between isolated and combined ligamentous contractures and identified CAS deformity curves. An analysis of the intraoperative knee alignment graphs revealed four distinct patterns of coronal deformity on the basis of intraoperative data: 13% diagonal, 18.5% C-shaped, 43.5% comma shaped, and 25% S-shaped. Each represents the change in varus and valgus alignment during FROM. All patterns were reproduced with cadaveric knees by recreating specific contracture constellations. A tight posterior capsule gave an S-shaped curve, a tight lateral collateral ligament gave a C-shaped curve, tight medial collateral ligament gave a diagonal curve, and a tight posterior lateral corner gave a comma-shaped curve. Release of the specific contractures resulted in correction of all patterns of deformity as measured by CAS. We propose a new classification system for coronal plane knee deformity throughout FROM. This system intends to match individual and combined soft tissue pathological contractures to specific stress-strain curves obtained through routine knee CAS preparation. This classification system may provide surgeons with a general guide for soft tissue balancing during computer-navigated TKA.

Recent resurgence in the interest of barbed suture has extended its application to wound closures in total joint surgery. Improved suture biomaterials and barb geometry has lead to consideration for its use in various orthopedic procedures including arthroplasty. The reported superior wound tensile stress distribution, no need for knots, and ability to close multiple layers with one suture make it an attractive option for deep wound closure after total joint surgery. However, inherent to the design of this suture are barbs that pose a risk of glove perforation and the potential for the transmission of blood borne pathogens. This study reports no increase in the incidence of glove perforation with use of barbed suture for deep wound closure after total joint arthroplasty.

Recent advances in the medical management of patients with human immunodeficiency virus (HIV) have led to improvement in their life expectancy. The growing numbers of HIV-positive patients are now living long enough to develop end-stage arthritis, as well as other long-term musculoskeletal complications of HIV infection and treatment. This has resulted in an increased demand for total joint arthroplasty among these individuals. However, the safety and outcomes of such procedures are frequently questioned in published reports. Although increased complication rates have often been reported, most studies have reported on joint arthroplasties in HIV patients with hemophilia. The most widely reported complications in both HIV-negative and positive hemophiliac patients are aseptic loosening and postoperative infection. A possible relationship between the rate of these complications and cluster of differentiation (CD4) lymphocyte count has also been proposed. In addition to hemophilia, other factors frequently comorbid with HIV infection, such as intravenous drug use, can further complicate the clinical outcomes of these individuals following total joint replacement procedures. Physicians treating HIV positive patients must remain aware of the risks and outcomes of total joint surgery in this group when counseling them on treatment options.

Total hip arthroplasty has become the standard treatment for end stage osteoarthritis. It is one of the most successful surgeries in the orthopedic armamentarium. It has been demonstrated as an effective way to decrease pain, improve quality of life and restore function in old and young patients alike. However, postoperative complications are still a risk associated with joint arthroplasty, which most significantly impacts patients' results and the total cost of care. As the number of patients that undergo total hip arthroplasty increases, it is our goal to try and minimize the incidence of perioperative complications. Perioperative complication after total hip arthroplasty includes both surgical complications such as: neurovascular injury, limb-length discrepancy, instability, and periprosthetic fracture, as well as medical complication such as: postoperative infection, deep vein thrombosis, pulmonary embolism, postoperative anemia, and cardiopulmonary complications. It is the objective of this review to discuss the different perioperative complications that occur after total hip arthroplasty, and to layout the treatment and preventive measures that can be taken in order to limit their occurrence and decrease the associated morbidity.

BACKGROUND: The recognition of the importance of femoral acetabular impingement (FAI) as a potential cause of hip pain has been stimulated by major efforts to salvage hip joints by reconstruction in order to prevent or delay the need for replacement. The purpose of this review is to define the nature of FAI, the various types, and how to make the diagnosis. METHODS: The review describes the characteristics of the hip that cause FAI and emphasizes understanding that the femoral and acetabular components normally function as a unit, complementing each other. RESULTSCONCLUSION: The methods of making the diagnosis of FAI and their limitations are described. If the acetabulum and femur are considered to be independent of each other, conflict may occur, hindering function, and not be apparent. The increasing frequency of making this diagnosis based on abnormal anatomy on one side of the joint, often in face of unclear physical findings, can bring the diagnosis into question. FAI seen in Perthes disease and acetabular dysplasia is explained. Knowing how to analyze the hip, being aware of the limitations of various available clinical and diagnostic studies, and recognizing the continued and ever-changing extensive body of literature is important and challenging. This primer is just the beginning.

Bilateral hip arthroplasty has been reported to be a safe and effective way to treat bilateral hip arthritis in a selective group of patients. We report a follow-up of 30 patients who underwent simultaneous bilateral total hip arthroplasty with hydroxyapatite implants and were followed for an average of 19.4 years. Patients had an average Harris Hip Score of 90 at the latest follow-up (range, 78-99). The average Western Ontario and McMaster Universities Arthritis Index questionnaire index score was 12 (range, 0-41), with high functional results on the 12-Item Short Form Health Survey (SF-12) and Oxford 12 questioners. Using the Kaplan-Meier survivorship analysis, with revision for any reason as an end point, survivorship was 94% at 12 years, 88% at 15 years, 74% at 18 years, and 61% at 23 years. All revisions were for the acetabular component, and the survivorship for the femoral component was 100% throughout the 23-year period. We conclude that bilateral uncemented total hip arthroplasty can provide satisfactory long-term clinical, radiological, and functional outcomes in patients even with older-generation polyethylene liners and stem designs.

PURPOSE: Rotating hinge knee prostheses are known to provide inherent stability. Yoke fractures of the hinged tibial insert of modern generation rotating hinge devices are a matter of continued concern. The aim of this study was to describe incidence and management of yoke fracture of the LPS hinged tibial insert. METHODS: Retrospective data analysis of two institutions identified 40 patients with a LPS total knee arthroplasty. Implant survival and prosthetic complications was calculated according to Kaplan-Meier. RESULTS: Out of the group of 40 patients, four fractures of the metal yoke occurred in four cases (failure rate: 10%). Furthermore, a second fracture occurred in two patients. The overall revision-free prosthetic survival was 57% at 38 months, while prosthetic survival until yoke fracture was 86% at 38 months. CONCLUSION: Handling yoke fractures as mechanical complication includes replacing the hinged insert, stabilization of the joint and joint line height preservation in order to decrease the cantilever effect at the insert-base plate interface.

The effect of obesity on the outcomes of total joint arthroplasties is an ongoing concern. As obesity becomes more endemic, new categories emerge, such as the 'super-obese.' We conducted a retrospective study to determine the difference in outcomes among the super-obese. When categorized according to body mass index (BMI), the overall rate of complications was higher for patients with BMI of 45 or higher. Super-obese patients had an odds ratio (OR) of 8.44 for developing inhospital complications. Most importantly, each incremental 5-U increase in BMI above 45 was associated with an increased risk of inhospital (OR, 1.69) and outpatient complications (OR, 2.71), and readmission (OR, 2.0), compared with patients with BMI of 45 to 50. Length of stay was increased by 13.8% for each 5-U increase in BMI above 45. There is a significant increased risk for complications in the super-obese population, and this continues to increase with BMI increases above 45. These data are important when counseling super-obese patients and should be accounted for in reporting quality outcome measures in this 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.