Although a tibial eminence avulsion fracture is a rare knee injury, it can result in some complications such as nonunion, limited range of motion, and anterior instability of the knee if the ...displaced fracture is not well reduced. Arthroscopic procedures for this fracture have been commonly performed in recent years. In patients with small fragments, a pullout operation is usually performed, but arthroscopic suture reduction is technically difficult. In addition, anterior instability of the knee may remain even if the fragment is well reduced at the time of the surgical procedure. Generally, surgeons are concerned about anatomic reduction compared with appropriate tensioning during surgery. Therefore, one of the key points to avoid remaining anterior instability of the knee is to obtain and maintain appropriate tensioning. The purpose of this article is to present an easy and safe technique for acquisition of appropriate tensioning using a tensioning device for tibial eminence avulsion fractures. Although it has limitations, this technique can facilitate the reduction of tibial eminence avulsion fractures and appropriate tensioning of the anterior cruciate ligament.
Abstract The purpose of the current study was to investigate the effect of knee flexion contracture on the knee mechanics both in affected and contralateral limbs during gait. Ten healthy old women, ...with mean age of 62 years, participated. Unilateral knee flexion contractures of 0, 15, and 30° were simulated with a knee brace. All subjects performed walking trials with or without the simulation. Net knee extension moments, net knee adduction moments (%BW Ht), external knee forces (%BW), and maximum axial loading rate (%BW/s) at the knee were calculated both in contracture side and non-contracture side under different contracture conditions. Bilateral net knee extension moment gradually increased as the angle of contracture increased. The net knee extension moments in non-contracture limb were significantly larger with 15 and 30° contracture than those without the contracture. Net knee adduction moment in non-contracture limb significantly increased with 15 and 30° contracture. The knee shearing forces in contracture side and the knee compressive force in non-contracture side also significantly increased with 15 and 30° simulation. As the flexion contracture became greater than 15°, maximum axial loading rate also significantly increased in non-contracture side. From our results, the knee flexion contracture greater than 15° led to mechanical overloads in both limbs. Correction of the contracture is clinically important to avoid any adverse effect.
Restoration of the natural joint line is a cornerstone for kinematically aligned total knee arthroplasty (TKA). The purpose of this study was to investigate the relative orientation of the tibial ...growth plate (GP) with respect to the tibial plateau (TP) for possible application in predicting natural joint line for knees with highly advanced osteoarthritis patient at the time of kinematically aligned TKA.
Images from computed tomography (CT) of 27 normal knees (9 males, 18 females; mean age, 31.6 years) were studied. Geometry of the GP was extracted from CT images, and its moment-of-inertia axes were calculated for the whole GP and the medial and lateral halves. Angular orientations of each GP axis with respect to the TP plane were measured in anatomical coordinates.
The TP and GP planes were oriented in 2.3 ± 1.8° of varus and 1.1 ± 1.9° of valgus relative to the tibial mechanical axis, respectively. With respect to the TP plane, the whole GP plane was inclined in 3.4 ± 1.5° of valgus. Orientation of the GP plane differed drastically between medial and lateral halves. The medial GP was in 4.9 ± 2.9° of varus and 1.8 ± 2.5° of anterior inclination, and the lateral half was in 10.4 ± 2.4° of valgus and 18.6 ± 4.0° of anterior inclination relative to the TP.
Angular orientation of the original TP plane can be predicted in reference to the GP plane and may provide reasonable guidance for the target bone resection angle of the tibia in kinematically aligned TKA.
Retrograde intramedullary nailing (RIMN) has been used for periprosthetic fracture of the distal femur after total knee arthroplasty (TKA), yielding good fracture union rates and satisfactory ...outcomes. However, RIMN for posterior-stabilized- (PS-) TKA risks malpositioning the entry point and disturbing the post of the tibial insert, and the surgeon therefore usually requires knee joint arthrotomy. We report a case of a 79-year-old male who was involved in bicycle accident resulting in periprosthetic fracture of the distal femur after PS-TKA. We performed osteosynthesis with arthroscopically assisted RIMN to define an appropriate entry point. RIMN for posterior-stabilized- (PS-) TKA risks malpositioning the entry point and disturbing the post of the tibial insert. Because arthroscopy can directly visualize the entry point and the tibial post without arthrotomy, arthroscopically assisted RIMN offers a useful technical option for periprosthetic fracture of the distal femur after PS-TKA.
Some differential diagnosis is thought due to knee pain after total knee arthroplasty (TKA) and fabella syndrome may cause post-TKA pain due to mechanical irritation. In this present case, a ...64-year-old woman experienced lateral knee pain which was localized at the iliotibial ligament 8 years after the surgery. Fabella syndrome was diagnosed, and fabellectomy provided immediate resolution of the pain. The previous reports have revealed the symptoms occurred after 6 days to a year after total knee arthroplasty. This case widens the time span and the consideration of the fabella syndrome. The reason of this late onset symptom could be due to the enlargement of the fabella over time. We report that the differential diagnosis of fabella syndrome should be thought in symptoms of late onset knee pain after total knee arthroplasty.
Abstract The TightRope RT (Arthrex, Naples, FL) is a suspensory device for anterior cruciate ligament reconstruction. However, there is a potential risk of the button being pulled too far off the ...lateral femoral cortex into the soft tissue because the adjustable loop is long. The purpose of this article is to present an easy and safe technique for self-flip. As to the preparation of the graft, we draw the first line in the loop of the TightRope RT at the same length as the femoral tunnel, and we draw the second line 7 mm longer than the length of the femoral tunnel as a self-flip line. Concerning passing of the graft, the side sutures are pulled from the lateral side. We stop pulling the sutures just at the self-flip line by holding the graft at the tibial end. The side suture is inclined to the medial side with strong pulling of the suture at full extension of the knee. Then the surgeon pulls the tibial end of the graft to feel a secure positioning of the button on the lateral femoral cortex. Although it has limitations, the present technique is easy and certainly helps surgeons achieve appropriate positioning of the button.
Abstract Unilateral total knee arthroplasty (TKA) would produce asymmetric changes of lower extremity in patients with bilateral varus deformity. Our purpose was to investigate whether asymmetry of ...the leg alignment would affect trunk bending in the coronal plane after unilateral TKA. Twenty patients (mean 76 years old) with bilateral end-stage knee osteoarthritis (OA) participated. Spine images during relaxed standing were obtained on pre- and postoperative day 21. As a result, the shoulder tilted more to the TKA side and the pelvis inclined more to the contralateral OA side. These results suggested that the trunk would bend away from the contralateral OA side after unilateral TKA in patients with bilateral end-stage knee OA and varus deformity. Asymmetry of the leg alignment led to asymmetric trunk bending.
Abstract The aim of this study was to evaluate weight-bearing condition after unilateral total knee arthroplasty (TKA) during standing and to examine whether the condition affects knee kinetics ...during gait in both limbs. Twenty-five patients, who underwent unilateral TKA for symptomatic bilateral osteoarthritis and who were on average 74 years old, participated. As a result, operated limbs became dominant in 80% of the patients. The other 20%, who had lack of knee extension during standing, showed more weight bearing in nonoperated knees. Furthermore, extension limitation in the operated knee in standing led to mechanical overload in the contralateral limb during gait. Therefore, to avoid progression of the osteoarthritis in the contralateral knee, it is important to acquire full extension in the operated knees during standing after unilateral TKA.
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