Wasted implants represent both an increased risk and cost to our healthcare system. In our institution, a sterilely packaged implant that is opened and not implanted is wasted in one out of 20 primary total knee replacement procedures. The cost of these wasted implants exceeds $1 million per year. We propose the introduction of a novel, computer based, e.Label and compatibility system to reduce implant-related medical errors and waste in total knee arthroplasty. We hypothesize that the implementation of this system will help reduce medical errors and wasted implants by improving and standardizing the visual markers and by ensuring that parts are compatible so that implant mismatches and inappropriate laterality are prevented. A software program was implemented which creates an e.Label for all components (Figure 1) and checks imbedded, manufacturer provided, compatibility charts to ensure that parts are of appropriate laterality, and are compatible with each other. Upon implementation, the program was studied prospectively for seven months and compared to a retrospective cohort in regards to number, type, and cost of wasted implants. Critical errors that were detected were also recorded.INTRODUCTION
METHODS
Flexion contractures are a common finding in an end-stage arthritic knee, occurring in up to 60% of patients undergoing total knee arthroplasty. Fixed flexion deformities may result from posterior capsular scarring, osteophyte formation, and bony impingement. It is essential to correct this deformity at the time of total knee arthroplasty, as a residual flexion contracture will result in joint overload and abnormal gait mechanics. This may translate to a slower walking velocity, shorter stride length, and pain. This presentation will discuss a systematic way of dealing with flexion contractures to ensure that the total knee arthroplasty will achieve full extension. The surgical technique for treating fixed flexion deformity about the knee includes release of the posterior cruciate ligament, posterior capsular release, adequate distal femoral bone resection, and removal of osteophytes. Post-operatively, attention must be divided between obtaining maximal flexion and full extension. Should a flexion contracture be noted upon the post-operative visit, additional measures should be taken to address it.
While advances in the design and fixation of implants have improved the survival and function of total knee replacements, blood loss from the procedure remains a significant concern. It is estimated that 800 mL to 1700 mL of blood is lost during the peri-operative period of a total knee replacement. Accordingly, allogenic blood transfusion following total knee replacement has been reported to be as high as fifty percent. Transfusion of allogenic blood, however, is not without risk, and has been shown to be associated with higher rates of infection, fluid overload, and increased length of stay following total knee replacement. Topical fibrin sprays applied to the exposed tissues and bony surfaces during total knee replacement has shown promise as an alternative hemostatic option in prior studies. By promoting hemostasis prior to tourniquet deflation, it is thought that post-operative blood loss will be reduced. In addition to reduction of total blood loss from TKA, it is possible that intra-articular hemarthrosis will be reduced, and patients may regain motion more quickly post-operatively. The purpose of this study, therefore, was to compare the total blood volume loss in patients undergoing primary total knee arthroplasty with and without the intra-operative application of a fibrin sealant. Secondary aims included a comparison of the rate of allogenic blood transfusions, post-operative pain scores, and knee range of motion between groups.
Surface replacement of the hip has become established as an alternative treatment to total hip replacement in the younger, active, male patient. By the very nature of preserving the femoral head and neck, there may be failures due to femoral neck fracture and femoral component loosening. Additionally, revisions of hip resurfacing for acetabular loosening may be necessary. Other scientific papers have described problems that may arise as a result of the metal-on-metal bearing either due to excess metal production or an immunologic-mediated reaction to the metal debris. Grammatopolous et al. describe poor results of revisions of surface replacements due to massive tissue destruction at the time of revision surgery, persistent pain, and swelling. In my experience with hip resurfacing, this complication is extremely rare. In my series of 925 resurfacings with a minimum of 2 year follow up, 12 revisions (1.3%) have been performed. Of these revisions, only 3 (0.3%) were for complications related to the metal-on-metal bearing; 2 for edge-loading and excess metal production, and 1 for metal hypersensitivity. None of the revision cases have had abductor destruction, or nerve/vascular involvement. Reconstruction of the joint was carried out with standard and revision components; post-operative function of these patients has been comparable to that of a primary total hip replacement. With careful monitoring of the post-operative resurfacing patient, problems can be identified early and surface replacement conversion can be performed with excellent results.
Precise knowledge of the Femoral Head (FH) arterial supply is critical to avoid FH avascular necrosis following open and arthroscopic intra-capsular surgical procedures about the hip. The Medial Femoral Circumflex Artery (MFCA) provides the primary FH vascular contribution. Distribution of vascular foramina at the Femoral Head-Neck Junction (FHNJ) has been reported previously using an imaginary clock face. However, no quantitative information exists on the precise Capsular Insertion (CI) and intra-capsular course of the MFCA Terminal Branches (TBs) supplying the FH. This study seeks to determine the precise anatomic location of the MFCA's TBs supplying the FH, in order to help avoid iatrogenic vascular damage during surgical intervention. In 14 fresh-frozen cadaveric hips (9 left and 5 right), we cannulated the MFCA and injected a polyurethane compound. Using a posterior approach, careful dissection of the MFCA allowed us to identify and document the extra- and intra-capsular course of the TBs penetrating the FHNJ and supplying the FH. An H-type capsulotomy provided joint access while preserving the intracapsular Retinaculum of Weitbrecht (RW), followed by circumferential capsulotomy at the acetabular margin exposing the FH. The dome of the FH was osteotomized 5 mm proximal to the Articular Border (AB) providing a flat surface for our 360° scale. Right-side equivalents were used for data processing.Introduction
Methods
Computer assisted surgery (CAS) systems have been shown to improve alignment accuracy in total knee arthroplasty (TKA), yet concerns regarding increased costs, operative times, pin sites, and the learning curve associated with CAS techniques have limited its widespread acceptance. The purpose of this study was to compare the alignment accuracy of an accelerometer-based, portable navigation device (KneeAlignÒ 2) to a large console, imageless CAS system (AchieveCAS). Our hypothesis is that no significant difference in alignment accuracy will be appreciated between the portable, accelerometer-based system, and the large-console, imageless navigation system. 62 consecutive patients, and a total of 80 knees, received a posterior cruciate substituting TKA using the Achieve CAS computer navigation system. Subsequently, 65 consecutive patients, and a total of 80 knees, received a posterior cruciate substituting TKA using the KneeAlignÒ 2 to perform both the distal femoral and proximal tibial resections (femoral guide seen in Figure 1, and tibial guide seen in Figure 2). Postoperatively, standing AP hip-to-ankle radiographs were obtained for each patient, from which the lower extremity mechanical axis, tibial component varus/valgus mechanical alignment, and femoral component varus/valgus mechanical alignment were digitally measured. Each measurement was performed by two, blinded independent observers, and interclass correlation for each measurement was calculated. All procedures were performed using a thigh pneumatic tourniquet, and the total tourniquet time for each procedure was recorded.Introduction
Methods
The debate regarding the importance of preserving the blood supply to the femoral head (FH) and neck during hip resurfacing arthroplasty (HRA) is ongoing. Several surgeons continue to advocate for the preservation of the blood supply to the resurfaced heads for both the current HRA techniques and more biologic approaches for FH resurfacing. Despite alternative blood-preserving approaches for HRA, many surgeons continue to use the posterior approach (PA) due to personal preference and comfort. It is commonly accepted that the PA inevitably damages the deep branch of the medial femoral circumflex artery (MFCA). This study seeks to evaluate and measure the anatomical course of the ascending and deep branch of the MFCA to better describe the area in danger during the posterior approach. In 20 fresh-frozen cadaveric hips, we cannulated the MFCA and injected a urethane compound. The Kocher-Langenbeck approach was used in all specimens. The deep branch of the MFCA was identified at the proximal border of the QF and measurements were taken. The QF was incised medially and elevated laterally, maintaining the relationship of the ascending branch and QF, and distances from the lesser trochanter were measured. The deep branch was dissected and followed to its capsular insertion to assess the course and relation to the obturatur externus (OE) tendon and the conjoint tendon (CT) of the short external rotators.Introduction
Methods
Hip resurfacing has grown rapidly since its introduction in the United States, as an alternative to total hip replacement in the younger, active patient. Some studies have suggested a steep learning curve and a higher complication rate when compared to THR. Existing studies have originated from the pioneering surgeons, using a specific type of resurfacing implant. The purpose of this study was to look at the experience of a single, non-inventor surgeon with the adoption of hip resurfacing, using 3 different implants. All consecutive hip resurfacings performed by the senior surgeon between 2004 and 2008 were included, providing a minimum 2 year followup period. 3 different implant types were used; 2 of these were used as part of the clinical trials, and 1 was used after US FDA approval. A total of 560 hip resurfacings were eligible for the study based upon a minimum of 2 year followup. Nine revisions were performed in this cohort (1.6%). 2 were femoral conversions to endoprostheses for femoral neck fracture; 3 additional femoral conversions were done for osteonecrosis of the femoral head. 1 acetabular revision only was performed for malposition. 2 revisions to THR of both the acetabular and femoral components were done for acetabular loosening and excessive metal production (edge loading). There was 1 revision for metal hypersensitivity. Overall, the K-M survival curve is 98.1% at 4 years. There was no difference with regard to survival from additional surgery with regard to the different implant types. Radiographic signs of failure were also documented. In this cohort, 3 femoral and 1 acetabular components were identified to be radiographically loose, giving a K-M survival from clinical and radiographic failure to be 96.8% at 4 years.M&M
Results
Alumina Ceramic liners are increasingly used in patients undergoing Total Hip Replacement (THR). The rate of fracture of ceramic liner is decreasing with improved manufacturing techniques from 1st to 3rd generation alumina-ceramic liners. We report the first case of a fracture of a modern, 4th generation alumina bearing ceramic liner, which incorporates a metal sheath to help avoid fracture. Our case is a 60 years old female presenting two years and three months after a bilateral total hip replacement using Stryker Trident cup, securfit stem and alumina on alumina bearing ceramic liner. Ceramic liners are commonly used, especially in young patients because of their excellent biocompatibility, low wear rate and superior tribology. Although fracture of ceramic liner is a less common complication of modern total hip arthroplasty, it is a major concern with the use of ceramic on ceramic THR, the reason being brittleness of ceramic. Cases of 3rd generation ceramic liner fracture have been reported which might be associated with impingement due to excessive anteversion of the socket in Asian patients who habitually squat. Habitual squatting, sitting cross legged and kneeling were not characteristic of this case. The patient presented with complains of mechanical grinding in left hip. She also reported a past history of clicking sound from left hip on extension of left hip and long stride gait. There was no history of trauma or fall. On examination she had a nonantalgic gait and left hip had audible and palpable crepitations. The range of motion on left hip was intact with no subluxation. Right hip was symptom free and examination did not detect any abnormalities.Introduction
Methods
