Wound condition after primary total knee arthroplasty (TKA) is important for prevention of periprosthetic infection. Any delay in wound healing will cause deep infection, which leads to the arthroplasty failure. Prevention of soft tissue problems is thus essential to achieve excellent clinical results. However, it is unknown as to the important surgical factors affecting the wound healing using detailed wound score after primary TKA so far. It was hypothesized that operative technique would affect wound healing in primary TKA. The purpose of the present study was to investigate and to clarify the important surgical factors affecting wound score after primary TKA. A total of 139 knees in 128 patients (mean 73 years) were enrolled. All primary TKAs were done by single surgeon. All patients underwent unilateral or bilateral TKA using Balanced Knee System®, posterior stabilized (PS) design (Ortho Development, Draper, UT) or Legion®, PS design (Smith and Nephew, Memphis, TN) under general and/or epidural anesthesia. Patients with immunosuppressive therapy, hypokalemia, poor nutrition (albumin < 3.4 g/dL), diverticulosis, infection elsewhere, uncontrolled diabetes mellitus (HbA1C>7.0%), obesity (Body Mass Index > 35 kg/m2), smoking, renal failure, hypothyroidism, alcohol abuse, rheumatoid arthritis, posttraumatic arthritis, and previous knee surgery were excluded. Hollander Wound Evaluation Score (HWES) was assessed on postoperative day 14. We evaluated age, sex, body mass index, HbA1C (%), preoperative femorotibial angle (FTA) on plain radiograph. In addition, intraoperative patella eversion, intraoperative anterior translation of the tibia, patella resurfacing, surgical time, tourniquet time, unidirectional barbed suture and length of skin incision were also evaluated as surgical factors. Multiple regression analysis was done using stepwise method to identify the surgical factors affecting HWES.Introduction
Methods
A longer operative time will lead to the development of any postoperative complications in total knee arthroplasty (TKA). According to previous reports, a significant increase in TKA procedure time done by novice surgeons was observed compared to high-volume surgeons. Our purpose was to investigate and to clarify the important maneuver necessary for novice surgeons to minimize a surgical time in TKA. A total of 300 knees in 248 patients, averaged 74.6 ± 8.7 years, were enrolled. All primary TKAs were done using same instruments (Balanced Knee System®, PS design, Ortho Development, Draper, UT) and same measured resection technique at 14 facilities by 25 orthopedic surgeons. Surgeons were divided into three surgeon groups (4 experts, 9 medium volume surgeons, 12 novices). All methods were approved by our institution's ethics committee. We divided the operative technique into 5 steps to make comparisons of step-by-step surgical time among surgeon groups of different levels. We defined Phase 1 as performing surgical exposure from skin incision to insertion of the intramedullary rod into the femur. Thereafter, the distal and AP surface of the femur, proximal tibia, the chamfer and PS box of the femur, and patella were resected in Phase 2. In Phase 3, a setup the trial component and a keel of the tibia were done after a confirmation of appropriate ligament balance using the spacer block. Then, a bone surface was irrigated with 2000ml of saline after the removal of the trial component. Subsequently, permanent components were fixed with use of bone cement in Phase 4. Finally, the final irrigation using 2000ml saline and wound closure were done in Phase 5. Every phase of the surgical time was recorded in each TKA. As a statistical analysis, operation data including length of skin incision, component size, operation time in each phase, and ratio of surgical time in each phase to whole surgical time, were compared using non-repeated measures of ANOVA and a post hoc Bonferroni correction. The threshold for statistical significance was set at a p value of less than 0.05.Introduction
Methods
For anatomical reconstruction in shoulder arthroplasty, it is important to understand normal glenohumeral geometry. Unfortunately, however, the details of the glenohumeral joint in Asian populations have not been sufficiently evaluated. There is a racial difference in body size, and this difference probably results in a difference in glenohumeral size. The purpose of this study was to evaluate three-dimensional geometry of the glenohumeral joint in the normal Asian population and to clarify its morphologic features. Anthropometric analysis of the glenohumeral joint was performed using computed tomography scans of 160 normal shoulders from healthy volunteers in age from 20 to 40 years. Using OsiriX MD, Geomagic Studio, and AVIZO software, the dimensions of humeral head width, humeral head diameter, glenoid height, glenoid width, and glenoid diameter were analyzed three-dimensionally (Figure 1). In diameter analyses, the humeral head was assumed to be a sphere and the glenoid was to fit a sphere (Figure 2–3). Sex differences in height, humeral length, humeral head width, humeral head diameter, glenoid height, glenoid width, and glenoid diameter were compared using Mann-Whitney U tests. The correlations between sides and among the respective parameters in the glenohumeral dimensions were evaluated with Spearman rank correlation tests. The significance level was set at 0.05 for all analyses.Introduction
Methods
We measured scapulothoracic motions during humeral abduction with different humeral rotations in healthy subjects and whole cadaver models and clarified that humeral rotation significantly influenced scapular kinematics. Scapular dyskinesis has been observed in various shoulder disorders such as impingement syndrome or rotator cuff tears. However, the relationship between scapular kinematics and humeral positions remains unclear. We hypothesised that humeral rotation would influence scapular motions during humeral abduction and measured scapular motion relative to the thorax in the healthy subjects and whole cadavers.Summary Statement
Introduction
Although proximal tibia vara is physiologically and pathologically observed, it is difficult to measure the varus angle accurately and reproducibly due to inaccuracy of the radiograph because of rotational and/or torsional deformities. Since tibial coronal alignment in TKA gives influence on implant longevity, intra- or extra-medurally cutting guide should be set carefully especially in cases with severe tibia vara. In this context, we measured the proximal tibial varus angle by introducing 3D-coordinate system. Three-dimensional models of 32 tibiae (23 females, 9 males, 71.2 ± 7.8 y/o) were reconstructed from CT data of the patients undergoing CT-based navigation assisted TKA. Clinically relevant mid-sagittal plane is defined by proximal tibial antero-posterior axis and an apex of the tibial plafond. After the cross-sectional contours of the tibial canal were extracted, least-square lines were fitted to define the proximal diaphyseal and the metaphyseal anatomical axis. The proximal tibia vara was firstly investigated in terms of distribution of proximal anatomical axis exits at the joint surface. TVA1 and TVA2 were defined to be a project angle on the coronal plane between the metaphyseal tibial anatomical axis and the proximal diaphyseal anatomical axis, and that between the metaphyseal tibial anatomical axis and the tibial functional axis, respectively. The correlations of each angle with age and femoro-tibial angle (FTA) were also examined. The proximal anatomical axis exits distributed 4.3 ± 1.7 mm medially and 17.1 ± 3.4 mm anteriorly. TVA1 and TVA2 were 12.5 ± 4.5°(4.4?23.0°) and 11.8 ± 4.4° (4.4?22.0°), respectively. The correlations of FTA with TVA1 (r=0.374, p<0.05) and TVA2 (r=0.439, p<0.05) were statistically significant.Materials & Methods
Results
Bi-cruciate substituting total knee arthroplasty (TKA) having two post-cam mechanisms was developed to substitute for cruciate ligament function after surgery. A previous study has shown many of these knees achieve high functional flexion. However, there is little information provided to differentiate between knees able to flex deeply and those that could not, although this is a major concern for surgeons. This study was conducted to compare the kinematic pathway from 0° to 90° in both groups. Twenty five knees were included in this study. All knees were diagnosed with osteoarthritis (OA) and all TKAs were performed by the same surgeon (WR) from November 2005 to September 2006. A mini mid-vastus surgical approach with posterior cruciate ligament (PCL) resection and patellar resurfacing was used in all cases. Computer navigation was used to guide bone cuts in all the cases. Patients' age averaged 63 years (range, 43–73) at the time of surgery. The study observations were performed at an average of 53 (SD 4) months after surgery. Knee motions were recorded using video-fluoroscopy while subjects performed stair up and down, and lunge activities. The three-dimensional position and orientation of the implant components were determined using model-based shape-matching techniques. This initial manual solution was refined using nonlinear least-squares optimization to maximize image-edge correspondence. Joint kinematics were determined from the three-dimensional pose of each implant component using Cardan/Euler angles. TKAs were divided into two groups according to the maximum lunge angles; TKAs achieved larger than 130° were defined as high flexion group (H group) and the ones from 110° to 130° were defined as moderate flexion group (M group). Tibial internal position and the AP locations of medial and lateral condyles were examined. Two TKAs were excluded since their maximum flexion was less than 110°. Twelve and eleven TKAs were defined as the H group (High flexing, average 137°, SD 4°) and the M group (Moderate flexing, average 121°, SD 5°), respectively. Tibial internal rotation averaged 10° (SD 4°) and 9° (SD 3°), respectively, at lunge position. The medial and the lateral condyles were located at 9 mm (SD 2 mm) and 17 mm (SD 3 mm) posterior to the tibial centerline during the lunge activity in the M group and at 11 mm (SD 2 mm) and 21 mm (SD 3 mm) in the H group. Tibial rotation was not statistically different (Figure 1), while AP position of the lateral condyle translated more backward in H group at 90° (Figure 2). The TKAs in the M group exhibited femoral forward motion from 0° to 20° flexion, while the H group moved backward (Figure 2). Our results revealed the post-cam mechanisms worked effectively in the H group TKA. The TKAs which acquired deep flexion successfully prevented the “roll forward motion” and had greater femoral posterior translation at 90° where the posterior post-cam mechanism engages. It appears adequate femoral posterior translation may be important to acquire deep flexion after TKA.
The purpose of this study was to investigate the effect of knee flexion contracture on trunk kinematics. Ten healthy old women, averaged sixty-two years, participated in this study. Subjects were tested at our laboratory with use of gait analysis system which consisted of eight retro-reflective markers (placed at bilateral acromion, anterior and posterior superior iliac spine, and iliaccrest), and five cameras. Unilateral (only right side) knee flexion contractures of zero, fifteen, and thirty degrees were simulated with a hard brace. All subjects performed walking trials at their preferred speed with or without simulation. First, level walking was measured without simulation, and then, with simulation at zero, fifteen and thirty degrees of flexion in order. Walking trials without brace was used as control. We evaluated walking velocity (m/s) and trunk kinematics (degrees). In the coronal plane, shoulder-pelvis bending angle was defined as the angle between shoulder girdle line and pelvic line. In the sagittal plane, anterior inclination of the trunk was defined by the slope linked right acromion and iliac crest, and anterior inclination of the pelvis was defined by the slope linked right superior anterior iliac spine and right superior posterior iliac spine. Shoulder-pelvis rotation angle was defined as the angle between shoulder girdle line and pelvic line in the axial plane. Maximum values were calculated. Walking velocity was significantly decreased at thirty degrees contracture (1.19 at controls, 0.98 at thirty degrees contracture). In the coronal plane, trunk significantly tilted leftward rather (4.5) than rightward (1.8) at thirty degrees contracture. In the sagittal plane, trunk anterior inclination significantly increased at thirty degrees contracture (0.1 at controls, 3.1 at thirty degrees contracture). However, pelvic anterior inclination was similar. In the axial plane, trunk significantly rotated rightward (6.7) rather than leftward (4.3) at thirty degrees contracture. Knee flexion contracture significantly influences physiological trunk kinematics in each plane. In particular, lateral bending to the contracture side was restricted, and this fact indicated that the lumbar spine may bend convexly to knee contracture side. These facts may result in Knee-Spine Syndrome.
