Arthroscopic Treatment of Tibial Eminence Avulsion Fracture With Suture Tensioning Technique.

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.

Surgical Technique to Bring Down the Patellar Height and to Reconstruct the Tendon for Chronic Patellar Tendon Rupture.

Although surgical treatment is the gold standard for chronic patellar tendon rupture, the technique of patellar tendon reconstruction is still difficult. Basically, good clinical results of surgical repair for acute patellar tendon rupture have been reported. However, the results of reconstructive surgery for chronic patellar tendon rupture are still inconsistent. Some surgical options have been previously reported. For example, surgeons need to choose between 1- and 2-stage reconstruction. Furthermore, contralateral bone-tendon-bone graft, ipsilateral semitendinosus tendon graft, Achilles tendon allograft, and an artificial ligament have been used to reconstruct the patellar tendon. Generally, surgeons are concerned about postoperative complications, including loss of knee flexion, quadriceps weakness, and wound problems. One of the key points to avoid these complications is to improve proximal patellar migration. The purpose of this article is to present an easy and safe technique to bring down the patellar height with polyethylene tape and to reconstruct the patellar tendon with an artificial ligament. Although it has limitations, the described technique can facilitate reconstruction of chronic patellar tendon rupture.

Self-flip Technique of the TightRope RT Button for Soft-Tissue Anterior Cruciate Ligament Reconstruction.

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.

Three-dimensional knee kinematics in patients with a discoid lateral meniscus during gait.

BACKGROUND: To date, the knee kinematics of a discoid lateral meniscus (DLM) has not been elucidated. The aim was to investigate the three-dimensional knee kinematics in knees with a DLM using gait analysis. METHODS: Ten patients (mean: 14years) diagnosed with bilateral DLM and unilaterally symptomatic snapping as well as 10 healthy controls (mean: 23years) participated in the study. Each patient with a DLM had unilaterally snapping knee in full extension and deep flexion. The three-dimensional gait analysis was performed with the point cluster technique. All subjects were asked to walk on a level floor at the speed of their choice. In the sagittal plane, knee excursion was separately evaluated during the weight acceptance phase and the mid-stance phase. In the axial plane, knee excursion during the stance phase was assessed. Finally, knee excursion during the whole gait cycle was evaluated in the frontal plane. Statistical comparison was conducted between groups, and between both sides in the DLM group. RESULTS: In the sagittal plane, knee excursions during the weight acceptance phase and the mid-stance phase were significantly smaller in the DLM group than in the control group; in addition, these were smaller on the symptomatic side than on the asymptomatic side in the DLM group. In the axial plane, knee excursion was also significantly smaller on the symptomatic side than on the asymptomatic side in the DLM group, whereas the frontal knee motion did not differ significantly. CONCLUSION: Less knee motion in the sagittal plane may prevent snapping during extension and flexion in patients with a DLM. LEVEL OF EVIDENCE: III.

Arthroscopic Visualization of Abnormal Movement of Discoid Lateral Meniscus With Snapping Phenomenon.

Discoid lateral meniscus with snapping phenomenon is a rare pathologic condition. The purpose of this article is to present an arthroscopic technique for the treatment of discoid lateral meniscus with snapping phenomenon. The patient is placed in the supine position for confirmation of snapping. As the patient's knee bends, it can be confirmed by arthroscopy that the posterior horn of the discoid lateral meniscus moves posteriorly and the central portion of the discoid lateral meniscus moves anteriorly at the same time with snapping at deep flexion angles. The anterior segment of the discoid lateral meniscus is found to be redundant and is often folded. On the contrary, as the patient's knee extends, the central portion is returned to the original position accompanied by snapping at nearly full extension. After excision of the central portion, the movement of the meniscus is evaluated again and the disappearance of the snapping phenomenon can be confirmed. Although it includes limitations, this application is easy and would certainly help surgeons to treat snapping knee with discoid lateral meniscus.

Effect of unstable meniscal injury on three-dimensional knee kinematics during gait in anterior cruciate ligament-deficient patients.

BACKGROUND: Our purpose was to clarify the differences of three-dimensional knee kinematics in anterior cruciate ligament (ACL)-deficient patients between with and without meniscal injury using gait analysis. METHODS: A total of 72 knees in 36 young athletes with primary and unilateral ACL injury, with a mean age of 22 years, participated. Gait analysis was done before surgery. According to the arthroscopic findings, patients were divided into two groups. The patients with an unstable meniscal tear were allocated to the meniscal injury group (ACL+M group), and the patients without a meniscal tear were allocated to the no meniscal injury group (ACL group). In the gait analysis, three-dimensional knee kinematics was evaluated and compared. RESULTS: The patients in both groups exhibited lower sagittal plane knee excursions and peak knee extension angles on the affected limb than on the unaffected limb during the mid-stance. In terms of the axial plane, a rotation angle was significantly smaller in the affected knees than in the unaffected knees in the ACL group. On the other hand, an opposite phenomenon was observed in the ACL+M group. Moreover, a significantly larger rotation angle in the affected knees during the stance phase and the whole gait cycle was observed in the ACL+M group than in the ACL group. CONCLUSION: Increased rotational motion during the gait was observed in the ACL-deficient knees combined with unstable meniscal injuries. Meniscal condition may be a key factor for compensatory gait mechanics to prevent rotatory instability in ACL-deficient patients patients. LEVEL OF EVIDENCE: III.

A Novel Surgical Technique for Patellar Fracture: Application of Extra-articular Arthroscopy With Hanger-Lifting Procedure.

We describe a novel operative technique for patellar fracture. The patient is placed in the supine position for setup of both an image intensifier and arthroscopy. After routine intra-articular inspection with an arthroscope, an extra-articular space including the prepatellar bursa is developed. The space is created with a lifting hanger applied from a portal wherein an arthroscope can then afford both intra- and extra-articular observation of the articular and bony surface of the patella. By use of an image intensifier, the fracture can be treated and fixed in percutaneous fashion with the aid of an arthroscope. This new technique offers surgeons a magnified view of the patella, both intra- and extra-articularly, through a minimally invasive procedure. Although it includes inherent risks and limitations, this new application of arthroscopy would certainly help surgeons to treat patellar fracture.

Gadd45g regulates dental epithelial cell proliferation through p38 MAPK-mediated p21 expression.

Ectodermal organs, such as teeth, hair follicles, and mammary glands, arise from their respective germs through epithelial-mesenchymal interactions during organogenesis. Growth arrest and DNA damage-inducible gene gamma (Gadd45g) have been shown to play important roles in various biological processes, such as stress responses, cell differentiation, and tumor suppression, through the regulation of cell proliferation and gene expression. We found that Gadd45g was expressed in enamel knots, which orchestrate tooth germ development as epithelial signaling centers. Gadd45g induced the expression of p21 and inhibited the proliferation of dental epithelial cells. The up-regulation of p21 expression was regulated by Gadd45g-mediated activation of the p38 MAPK pathway. Thus, our results suggest that Gadd45g is involved in the regulation of p21-mediated epithelial cell proliferation through the p38 MAPK pathway during tooth organ development.

The "coiling-up procedure": a novel technique for extra-articular arthroscopy.

The "coiling-up procedure" is a novel technique for extra-articular arthroscopy. A coil-shaped lifter is used to create the extra-articular working space, and a dry arthroscopy is performed. It can be combined with conventional intra-articular arthroscopy to enable direct vision from both inside and outside the joint. We have successfully used this technique to perform a vastus lateralis release in cases of painful bipartite patella. This is an innovative technique that offers the possibility of expanding the indications for extra-articular arthroscopy to other areas of the body. We describe in detail the technique for this new procedure in the knee.

Medial patellofemoral ligament reconstruction with hanger lifting procedure.

Medial patellofemoral ligament (MPFL) reconstruction has become a common surgical procedure in the treatment of recurrent dislocation of the patella. A technique of MPFL reconstruction with the "hanger lifting procedure" using extra-articular arthroscopy is presented. After conventional intra-articular arthroscopy, an incision about 1 cm long is made at the superomedial edge of the patella. A bone tunnel is created with a guide pin and overdrilling method, from this portal to the subcutaneous surface of the patella. Using a semi-loop-shaped hanger, the harvested Gracillis tendon is passed through the bone tunnel using a passing pin. Under extra-articular arthroscopy with the "hanger lifting procedure", this tendon is then led back to the superomedial portal. Both ends of the Gracillis tendon are then led to the femoral fixation site posterosuperior to the medial epicondyle with a tendon passer, and fixed by an absorbable interference screw. This procedure can be performed under a minimum incision using a hanger, but control radiographs should be taken to confirm appropriate placement of bone tunnels.

Hanger-lifting procedure in knee arthroscopy.

We propose a unique arthroscopic technique, the "hanger-lifting procedure." Unlike conventional arthroscopy, the space in which the arthroscope is placed is not a joint space filled with water but a subcutaneous space filled with air. The space is kept lifted by a semi-loop-shaped hanger and a retraction system by use of a wire. In general, arthroscopes are unable to be applied outside the joint because of the lack of a cavity. However, this method can provide extra-articular visualization of the knee in addition to standard intra-articular visualization. This approach is useful for lateral release of the knee extensor and bipartite patellae, allowing direct vision from both outside and inside the joint. One possible complication is subcutaneous effusion or interstitial edema. Compressive dressings should be applied to prevent subcutaneous effusion after surgery. However, the combination of conventional arthroscopy by use of saline solution and the hanger-lifting technique by use of air arthroscopy can provide an excellent view inside and outside the joint. This technique may continue to evolve, and although some points in the technique can be improved, this method is useful in joint surgeries.