OBJECTIVEto investigate if the cartilaginous surface and corresponding osseous contour of the patellofemoral joint match in the axial plane for providing theoretical basis with evaluating alignment of patellofemoral joint and designing the part of patellofemoral joint in knee prosthesis.

METHODSfrom January 2009 to March 2010, 9 human cadaver knees were prepared, which chandra of patellofemoral joint didn't degenerate. Each specimen was sectioned in the axial plane at 20° to 30° knee flax. The cross-sections revealed characteristics in the bony anatomy and corresponding articular surface geometry of the patellofemoral joint in the axial plane. Evaluating parameters included osseous patella congruence angle (OPCA), chondral patella congruence angle (CPCA), patella chondral convex point parameter (PCCPP), patella subchondral osseous convex point parameter (PSOCPP), the parameters of the deepest (chondral or osseous) point of the intercondylar sulcus. After that, the osseous and cartilaginous contours and subchondral osseous contours of the patella in the axial plane were analyzed through MRI data of 11 patients who didn't degenerate in patellofemoral joint cartilage. Parameters as same as cadaver knees were compared.

RESULTSdata from specimens of OPCA was (-4.5 ± 1.1)°, CPCA was (0.5 ± 0.8)°, PCCPP was 1.13 ± 0.11, PSOCPP was 1.67 ± 0.14, PCDPIS was 1.35 ± 0.28, PODPIS was 1.38 ± 0.33. Date from MRI of OPCA was (-3.8 ± 1.4)°, CPCA was (0.7 ± 1.0)°, PCCPP was 1.05 ± 0.21, PSOCPP was 1.73 ± 0.18, PCDPIS was 1.41 ± 0.21, PODPIS was 1.37 ± 0.27. The patella exhibited significant differences in the bony vs. chondral anatomy (P < 0.05), but the intercondylar sulcus nearly match in the bony vs. chondral anatomy.

CONCLUSIONSthe cartilaginous surface and corresponding osseous contour of the patella don't match in the patellofemoral joint axial plane, but that of the trochlea nearly matches. This is very important for accurately evaluating alignment of patellofemoral joint because the normal osseous alignment of patellofemoral joint don't represent the normal alignment and helpful for designing the part of patellofemoral joint in knee prosthesis.

Biomechanical Phenomena ; Cartilage, Articular ; anatomy & histology ; Femur ; anatomy & histology ; Humans ; Patella ; anatomy & histology ; Patellofemoral Joint ; anatomy & histology

A sagittal plane model of knee joint based on crossed-four-bar-linkage-based tibiofemoral joint model has been developed using geometric and force equilibrium constraints. The model predicts and explains the movement of contact point on the patella and femur, variation of patellar and patellar tendon angle, variation of patellar mechanism angle and variation of patellofemoral contact force and patellar tendon force. The computed results agree well with the published experimental results.
Biomechanical Phenomena ; Humans ; Knee Joint ; anatomy & histology ; physiology ; Models, Biological ; Movement ; physiology ; Patella ; anatomy & histology ; physiology

PURPOSE: The anterolateral thigh flap has many advantages over other conventional free flaps. But the anterolateral thigh flap has yet to enter widespread use because perforating arteries exhibit a wide range of anatomic variations and are difficult to dissect when small. The aim of this study is to identify the vascular variability of perforating arteries and pedicle in the anterolateral thigh free flap. METHODS: We studied 12 cadavers and dissected 23 thighs. An anterolateral thigh flap (12x12cm) was designed and centered at the midpoint of the line drawn from anterior superior iliac spine to the superolateral border of the patella. After we identifed the perforating arteries we dissected up to their origin from lateral circumflex femoral artery along descending branch of lateral circumflex femoral artery. We then investigated the number and the position of perforating arteries, length and diameter of vascular pedicle and pattern of lateral circumflex femoral arterial system. RESULTS: On average 2.3+/-1.1 perforating arteries per thigh were identified. The musculocutaneous perforators were 63.1%. In those perforators five perforators were arose from transverse branch of lateral circumflex femoral artery and two were arose from rectus femoral artery. Most of the perforators were near the intermuscular septum between rectus femoris muscle and vastus lateralis muscle. The length and diameter of pedicle were 11.9+/-3.5cm and 3.1+/-0.8mm on average. CONCLUSION: This study will be helpful for the success in anterolateral thigh free flap.
Anatomy, Regional ; Arteries ; Cadaver ; Femoral Artery ; Free Tissue Flaps ; Muscles ; Patella ; Quadriceps Muscle ; Spine ; Thigh

BACKGROUND: We would like to analyze the risk factors of no thumb test among knee alignment tests during total knee arthroplasty surgery. METHODS: The 156 cases of total knee arthroplasty by an operator from October 2009 to April 2010 were analyzed according to preoperative indicators including body weight, height, degree of varus deformity, and patella subluxation and surgical indicators such as pre-osteotomy patella thickness, degree of patella degeneration, no thumb test which was evaluated after medial prepatella incision and before bone resection (1st test), no thumb test which was evaluated with corrective valgus stress (2nd test, J test), and the kind of prosthesis. We comparatively analyzed indicators affecting no thumb test (3rd test). RESULTS: There was no relation between age, sex, and body weight and no thumb test (3rd test). Patellar sulcus angle (p = 0.795), patellar congruence angle (p = 0.276) and preoperative mechanical axis showed no relationship. The 1st no thumb test (p = 0.007) and 2nd test (p = 0.002) showed significant relation with the 3rd no thumb test. Among surgical indicators, pre-osteotomy patella thickness (p = 0.275) and degeneration of patella (p = 0.320) were not relevant but post-osteotomy patellar thickness (p = 0.002) was relevant to no thumb test (3rd test). According to prosthesis, there was no significance with Nexgen (p = 0.575). However, there was significant correlation between Scorpio (p = 0.011), Vanguard (p = 0.049) and no thumb test (3rd test). Especially, Scorpio had a tendency to dislocate the patella, but Vanguard to stabilize the patella. CONCLUSIONS: No thumb test (3rd test) is correlated positively with 1st test, 2nd test, and post-osteotomy patella thickness. Therefore, the more patella osteotomy and the prosthesis with high affinity to patellofemoral alignment would be required for correct patella alignment.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Female ; Humans ; Intraoperative Care/*methods ; Male ; Middle Aged ; Osteotomy ; Patella/*anatomy & histology/surgery ; Physical Examination ; Risk Factors

BACKGROUND: Due to its small size, variable shape, and lack of distinct anatomical landmarks, osteoarthritic knees make a precise patellar resection extremely difficult. METHODS: We performed virtual patellar resection with digital software using three dimensional computed tomography scans of knees from 49 patients who underwent primary total knee replacement at our hospital. We compared 2 commonly used resection methods, the tendon method (TM) and the subchondral method, to determine an ideal resection plane with respect to the symmetry and thickness of the patellar remnant. RESULTS: The TM gave a thicker resected patella, and a less oval cut surface shape, which gives better coverage for a domed prosthesis. Both methods, however, gave a symmetric resection both superior-inferiorly, as well as mediolaterally. CONCLUSIONS: Although TM appears statistically better with respect to the thickness and cut surface shape, only further intraoperative studies with long-term clinical follow-up may provide us with the most appropriate patellar resection method.
Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/*methods ; Female ; Humans ; Imaging, Three-Dimensional/*methods ; Middle Aged ; Patella/*anatomy & histology/*surgery ; Surgery, Computer-Assisted/*methods ; Tomography, X-Ray Computed/*methods