Intermediate-Term Survivorship of Total Hip Arthroplasty With a Proximally Coated Tapered-Wedge Femoral Stem: A Retrospective, Multi-Center Registry Review.

BACKGROUND: Short tapered-wedge stems have been used frequently over the past decade, but long-term follow-up data are not readily available in the literature. METHODS: A retrospective outcomes review was conducted to assess survivorship and clinical outcomes for the TRI-LOCK® Bone Preservation Stem (TRI-LOCK BPS; DePuy Synthes, Warsaw, IN, USA), a proximally coated, tapered-wedge femoral stem. RESULTS: In a cohort of 2,040 hips, Kaplan-Meier survivorship estimates (95% CI {confidence interval}; N with further follow-up, where N is the number of hips remaining at each post-operative interval), with survivorship defined as no revision of any component for any reason were 96.6% (92.8%,98.4%; 45) at eight years under the clinical assumption and 98.6% (97.9%,99.1%; 90) at 14 years under the registry assumption. With survivorship defined as stem revision for any reason, estimates were 97.7% (93.7%,99.2%; 45) at eight years under the clinical assumption and 99.2% (98.6%,99.5%; 90) under the registry assumption. Mean Harris Hip Scores and WOMAC scores were 90.08 and 21.98, respectively, at 10 years postoperatively. CONCLUSION: Our evaluation demonstrates excellent construct and stem survivorship and clinical outcomes at intermediate-term postoperative follow-up.

Variability in Distal Femoral Anatomy in Patients Undergoing Total Knee Arthroplasty: Measurements on 13,546 Computed Tomography Scans.

Proper mechanical and rotational alignment plays an important role in achieving the success of the total knee arthroplasty (TKA). The purpose of the present study was to retrospectively determine with computed tomography (CT) the distal femoral valgus angle (DFVA) and femoral rotation angle (FRA). Our cohort included 13,546 CT scans of patients undergoing TKA. The average DFVA was 5.7 ± 2.3° (range from 1 to -16°) with 13.8% of patients identified as outliers. The distal FRA angle average was 3.3 ± 1.5° (range from -3 to 11°) with 2.8% of patients identified as outliers. These data can be useful in making orthopedic surgeons aware of the variability of femoral anatomy. Using the same cutting angle may lead to malposition of the femoral component.

Short-term results of a custom triflange acetabular component for massive acetabular bone loss in revision THA.

Managing severe periacetabular bone loss during revision total hip arthroplasty (THA) is a challenging task. Multiple treatment options have been described. A custom triflanged acetabular component is a recent treatment option. The authors retrospectively reviewed 19 hips in 19 patients with massive periacetabular bone loss (Paprosky types 3A/3B and AAOS types III/IV) treated with custom triflanged acetabular components. Mean patient age at surgery was 58 years (range, 42-79 years).At an average follow-up of 31 months (range, 16-59 months), mean Harris Hip Score had improved from 38 preoperatively to 63 postoperatively, and mean Western Ontario McMaster Osteoarthritis Index scores had improved from 43 preoperatively to 26 postoperatively. Sixty-five percent of cases were considered successful. Three (16%) patients had significant complications; 2 (11%) custom triflanged acetabular components were removed due to failure. At last follow-up, 6 (43%) of 14 patients reported that their ambulatory status was improved vs their preoperative status, 3 (21%) reported no change, and 5 (36%) reported that their ambulatory status was worse than their preoperative status.In this study, the use of a custom triflanged acetabular component for massive periacetabular bone loss in revision THA had less favorable results than in other reports. Use of a custom triflanged acetabular component for massive periacetabular bone loss in revision THA remains a viable option, but surgeon and patient expectations should be realistic.

Unusual presentation of cobalt hypersensitivity in a patient with a metal-on-metal bearing in total hip arthroplasty.

Pain after hip arthroplasty is less likely to be attributed to dermal sensitivity from orthopedic implants. Unexplained persistent pain after hip arthroplasty typically leads to further investigation, occasionally revealing a metal sensitivity. Our case study presents an unusual finding of a delayed type IV cobalt hypersensitivity in a patient several years after use of cobalt in the contralateral hip. Recognition and a high index of suspicion are needed for timely treatment of metal allergy when it presents as persistent pain after hip arthroplasty.

Use of inpatient continuous passive motion versus no CPM in computer-assisted total knee arthroplasty.

BACKGROUND: Continuous passive motion (CPM) has shown positive effects on tissue healing, edema, hemarthrosis, and joint function (L. Brosseau et al., 2004). CPM has also been shown to increase short-term early flexion and decrease length of stay (LOS) ( L. Brosseau et al., 2004; C. M. Chiarello, C. M. S. Gundersen, & T. O'Halloran, 2004). The benefits of CPM for the population of patients undergoing computer-assisted total knee arthroplasty (TKA) have not been examined. PURPOSE: The primary objective of this study was to determine whether the use of CPM following computer-assisted TKA resulted in differences in range of motion, edema/drainage, functional ability, and pain. METHODS: This was an experimental, prospective, randomized study of patients undergoing unilateral, computer-assisted TKA. The experimental group received CPM thrice daily and physical therapy (PT) twice daily during their hospitalization. The control group received PT twice daily and no CPM during the hospital stay. Both groups received PT after discharge. Measurement included Knee Society scores, Western Ontario McMaster Osteoarthritis Index values, range of motion, knee circumference, and HemoVac drainage. Data were collected at various intervals from preoperatively through 3 months. RESULTS: Although the control group was found to be higher functioning preoperatively, there was no statistically significant difference in flexion, edema or drainage, function, or pain between groups through the 3-month study period.

Dermabond efficacy in total joint arthroplasty wounds.

The goals of wound closure are a low infection rate and timely healing. Total joint arthroplasty (TJA) requires mobile recovery, and, therefore, a high-tension wound care environment. We conducted a study to compare the efficacy of high-viscosity Dermabond (Ethicon, Somerville, New Jersey) and the efficacy of surgical staples in healing high-tension, mobile surgical sites of TJA. Of 236 total knee arthroplasties and 223 total hip arthroplasties (459 surgeries total), 250 were performed with Dermabond and 209 with staples. According to χ2 analysis, case and control infection rates were equivalent. Signs of acute inflammation (redness, drainage, dehiscence) also were statistically equivalent. Absence of staples accounted for a significant decrease in tape blisters and skin abscesses. Dermabond is superior to staples in high-tension wound care.

Low incidence of postoperative complications due to pin placement in computer-navigated total knee arthroplasty.

Computer-navigated joint arthroplasty surgery using optical tracking systems requires arrays fixated to bone via pins. Reports of fractures at pin sites have raised concern about safety. We reviewed the postoperative complications occurring in a single-surgeon series of 984 consecutive primary total knee arthroplasties. All pins were placed unicortically and connected by a dual pin array. Femoral pins were placed into the medial epicondyle, and tibial pins were placed in the shaft 10 cm inferior to the joint line. There were no fractures. Seventeen (1.7%) patients had minor pin-related complications. Twelve patients had a superficial infection around the tibial pin sites, which resolved with antibiotics. None of the infections required readmission or reoperation. We believe pin placement to be safe and effective with proper technique.

Minimally invasive hip resurfacing compared to minimally invasive total hip arthroplasty.

BACKGROUND: Since its March 2006 FDA approval in the United States, Birmingham hip resurfacing (BHR) has been a popular alternative to hip arthroplasty for the younger patient population. Data to date has shown a trend toward low incidence of dislocation and good survivorship. METHODS: 128 patients operated on by a single surgeon from July 2006 to December 2008 were reviewed for complications, pain, and function. A group of single incision, minimally invasive standard total hip replacements (106 cases) in 2008 was used for comparison of the same outcomes. CONCLUSION: Pain, function, and total Harris Hip scores were all improved by the 2 year mark and better than the total hip group. Overall incision lengths decreased over the study time period. The average age of the BHR recipient was 51 years, approximately 14 years less than the total hip mean age. Pain in the Birmingham group improved by 32 points at the 3 month mark. By the end of 2 years, the Birmingham group Harris Hip score mean was nearly perfect at 98.5 points. Rare incidence of complications, marked decreased pain scores and marked elevation in function were results found in this sample of Birmingham resurfacing.

Technology and cost-effectiveness in knee arthroplasty: computer navigation and robotics.

Our aim in this article is to describe the impact that navigation technology has had on the market share of a community hospital and, specifically, to determine whether a high-volume surgeon using these technologies actually costs the hospital more than other surgeons at the same hospital and more than national means. In addition, we develop a comparable cost-effectiveness model for robotic technology in unicompartmental knee arthroplasty to demonstrate the potential cost-effectiveness at the same hospital.

Role of navigation in total hip arthroplasty.

Current uses of computed tomography-based and imageless navigation systems for total hip arthroplasty include proper placement of the acetabular component, measurement of limb-length changes, enablement of minimally invasive surgery, and proper placement of components for hip resurfacing procedures. This article provides an overview of the rationale for computer-assisted surgery in total hip arthroplasty and hip resurfacing. The experience of the senior author (M.L.S.) with computer-assisted surgery for hip arthroplasty has demonstrated improved position of the acetabular component as compared with the position attainable with use of mechanical instruments, maintenance of appropriate position of the acetabular component during minimally invasive surgery, and appropriate positioning of the femoral and acetabular components during the learning curve for hip resurfacing procedures.

Imageless navigation in hip resurfacing: avoiding component malposition during the surgeon learning curve.

BACKGROUND: Studies suggest that hip arthroplasty procedures performed in specialty hospitals or by physicians in practices with a high surgical volume are associated with a decreased rate of adverse outcomes related to component malpositioning. Little is known, however, about the influence of imageless computer navigation systems on the procedural experience of the surgeon and the subsequent alignment of implants in the setting of hip resurfacing arthroplasty. METHODS: Seventy-one consecutive hip resurfacing arthroplasties in which the components were placed with use of computer-assisted navigation were reviewed retrospectively. Intraoperative femoral and acetabular component parameters were compared with postoperative radiographic alignment values. Within this single surgeon series, operative time, intraoperative cup inclination and femoral stem-shaft angles, and postoperative cup inclination and femoral stem-shaft angles were measured and compared over the course of three discrete, sequential operative time periods. Patient demographic data and surgical parameters, including blood loss, surgical approach, and anesthesia time, were recorded. RESULTS: No significant difference was seen between the intraoperative and postoperative cup inclination angles. A significant difference was noted between the intraoperative and postoperative femoral stem-shaft angles; however, the mean angles in all groups had a valgus orientation when compared with the mean native neck angles. Over three sequential operative time periods, computer-assisted navigation produced consistent values with regard to intraoperative cup inclination (43 degrees , 44 degrees , and 40 degrees ) and postoperative radiographic alignment of the cup (46 degrees , 44 degrees , and 43 degrees ) and femoral stem (148 degrees , 147 degrees , and 144 degrees ), despite different levels of surgeon experience. Operative times significantly decreased with surgeon experience, showing the largest decrease after the first sequence interval (110, ninety-eight, and ninety-five minutes, respectively). There was a significant difference with evolving surgeon experience concerning intraoperative stem placement (144 degrees , 142 degrees , and 138 degrees , respectively) despite the mean values remaining well-clustered. No femoral notching occurred throughout the series. CONCLUSIONS: Computer-assisted navigation is a dependable and accurate method of positioning hip resurfacing components during arthroplasty, as measured by cup inclination, and a reliable technique for valgus stem placement and avoidance of notching. Furthermore, computer navigation allows for consistency of component alignment independent of procedural experience.

Computer-assisted surgery in total knee arthroplasty:recent advances.

Computer-assisted surgery (CAS) for total knee replacement was first approved for use in the U.S. in 2001. Since its introduction, however, there has been a rapid expansion of this technology and several different types of navigation systems have been developed by several different manufacturers. Each new version of the software has incorporated increasingly sophisticated analysis modules to allow not only accurate alignment of the limb and component position, but also to assess ligament balance and knee kinematics. The purpose of this chapter is to review the basic elements of CAS, the author's clinical experience, and improvements currently being developed with this technology.