Introduction:

With the growing emphasis on the cost of medical care, there is renewed interest in the productivity and efficiency of surgical procedures. We have developed a method to systematically examine the efficiency of the surgical team during primary total knee replacement (TKR). In this report, we present data derived from a series of procedures performed by different joint surgeons. This data demonstrates a variation between the duration and efficiency of each step in this procedure and its relationship to the experience and coordination of the surgeon working with the scrub team.

INTRODUCTION:

The diagnosis of periprosthetic joint infection (PJI) remains a serious challenge. Based on previous work, we believe that biomarkers will become the mainstay of diagnosing PJI in the future. We report on completion of our 8 year comprehensive biomarker program, evaluating the diagnostic profile of the 15 most promising synovial fluid biomarkers.

Introduction

With the growing emphasis on the cost of medical care, there is renewed interest in the productivity and efficiency of surgical procedures. We have developed a method to systematically examine the efficiency of the surgical team during primary total knee replacement (TKR). In this report, we present data derived from a series of procedures performed by different joint surgeons. This data demonstrates a variation between the duration and efficiency of each step in this procedure and its relationship to the experience and coordination of the surgeon working with the scrub team.

Introduction: morphological analysis of the general shape of the bones and of their particular variations according to the patient age, gender and pathology is an important step to improve the orthopedic management. We aimed to performed a gender specific analysis of the bi and tridimensional anatomy of the distal femur in vitro and in vivo.

Materials and Methods: in vitro data were obtained from CT-scan performed on 92 dry men femurs and 52 dry women femurs. Using a manual contouring method and a segmentation method, tridimensional reconstructions were obtained and according to two different algorithms, the regions of discrepancies between men and women were determined. An automatic calculation of 59 defined measurements was then performed. In vivo data providing from 59 CT-scans of men femur and 73 CT-scan of women femurs were acquired. Standardized bidimensional measurements at the level of the trochlear cut were performed.

Results: in vivo, statistically significant differences were observed for the: medio-lateral distance (M-Ld women=7.4±0.4cm vs M-Ld men=8.4±0.5cm; p< 0.0001), anteroposterior distance (A-Pd women=5.9±0,4cm vs A-Pd men= 6.4±0.4cm; p< 0.0001) and for the ratio anterior-posterior distance/medio-lateral distance (p< 0.0001). The trochlear groove angle was comparable in the two groups. In vitro, the tridimensional shape of the distal femur was more trapezoidal in women than in men. Medio-lateral distances were also statistically greater in men than in women (p< 0.01), the ratio anterior-posterior distance/medio-lateral distance was also statistically greater in men than in women (p< 0.01) and the Q angle more open in women than in men (p< 0.01).

Discussion: Three types of differences between men and women were observed in this gender specific evaluation of the distal femur anatomy. First, for a same anteroposterior distance, the medio-lateral distance was smaller in women. Second, the global shape of the distal femur was more trapezoidal in women and third the Q angle was more open in women. This gender specific anatomy should be clinically considered when performing total knee arthroplasty in women and gender specific implants may be required.

Following successful total knee arthroplasty, tibial periprosthetic fractures are rare and patellar fractures are sufficiently dependent upon vascular issues that they constitute a somewhat separate topic. Femoral periprosthetic fractures are extremely difficult to manage, usually producing flexion, internal rotation, and varus deformities. Malunion from insufficient stabilisation and stiffness from excessive immobilisation are the polar perils to be avoided. A variety of conservative treatment options will be discussed, ranging from casting and traction to open reduction and internal fixation. Within the latter category, recent enthusiasm has swayed the pendulum of therapeutic options towards intramedullary fixation. This can be accomplished using Rush rods, interprosthetic and intramedullary rods with fixation screws, and revisional knee arthroplasty techniques with large intramedullary stems. As a general rule, the more aggressive techniques provide the better results, although the severe technical difficulties of managing the osteopenic femoral medullary bone require special techniques and skills. Nonetheless, optimal results producing less than 5° of angulation and over 100° of motion are to be expected.

The current growing enthusiasm for unicompartmental and “minimally invasive” arthroplasties is in no small part predicated on the appeal of a mini-incision. While the quest for ever less intrusive surgical procedures is certainly laudable, the appropriate focus should be more on the quality of the procedure and its results, than on cosmetics and recuperative time. The marketing appeal of a “mini-incision” is undeniable, although it is often used as a “bait and switch” technique for attracting surgical candidates. It is undeniable that expense, pain, and time out of work may be less with these procedures. On the other hand, performing an arthroplasty through a minimal incision increases the complexity and difficulty for surgeons, a reality, which is usually inversely proportional to the quality of the result. Our societal quest for speed may divert our attention from the fact that these are temporising procedures at best, whose longterm success in the general marketplace is completely unknown and which may suffer the fate of other such minimally invasive techniques as interpositional skids, viscosupplementation, and abrasion chondroplasty. The extremely high and long lasting success rates of conventional total knee arthroplasty are difficult to approach, and we are indeed sending a mixed message to our patients when we attempt to sell lesser technologies based on small scars. As we all know, size does matter!

As defined by body mass index (body weight in kilograms divided by height in meters squared) one out of three Americans is “overweight”. The excuses and reasons for this situation are genetic, dietary, cultural, and physiologic – occasionally related to the severity of arthritis, which precludes normal activity. Scandinavian literature has shown a higher incidence of gonarthrosis in obese patients as well as some indication of decremental surgical results. Patient selection requires identification of the distribution of the obesity and its implications for knee surgery. Anaesthetic techniques should stress regional approaches, oxygenation, and modified postoperative regimens. Surgical incisions should be midline, longer than normal, and involve eversion of the patella within its fat envelope. Increased tourniquet length as well as width is mandatory. Wound complications are certainly more common, while the overall statistics from knee arthroplasty in the obese are not discouraging. Greater pressure is placed on the surgeon to achieve perfect alignment and balance, less the patient’s weight unmask the imperfections of the arthroplasty. Sadly, only 18% of people lose weight after joint replacement.