Accuracy of different navigation systems for femoral and tibial implantation in total knee arthroplasty: a randomised comparative study.

PURPOSE: It remains to be established whether optical computed tomography (CT)-free and acceleration-based navigation systems differ in terms of implantation accuracy and clinical outcomes for total knee arthroplasty. This randomised prospective study compared the implantation accuracy of these two navigation systems in total knee arthroplasty. METHODS: Optical CT-free navigation (ExactechGPS) or acceleration-based navigation (KneeAlign2) was randomly assigned to the left or right knee of 45 patients who underwent a single-stage bilateral total knee arthroplasty: the ExactechGPS (n = 45) and KneeAlign2 groups (n = 45) were compared. Component alignments were evaluated using three-dimensional computed tomography and radiography at pre- and post-surgery. Implantation accuracy of the component alignment, proportion of outliers, postoperative range of motion, and Japanese Orthopaedic Association (JOA) score were compared between the systems. RESULTS: The implantation accuracies of the lower-extremity mechanical alignment, coronal femoral component angle, coronal tibial component angle, sagittal femoral component, axial femoral angle, and axial tibial angle had no significant difference between the groups. The implantation accuracy of the sagittal tibial component angle was superior in the ExactechGPS than the KneeAlign2 group (1.3° vs. 1.8°, P = 0.034). The proportions of outliers, range of motion, and JOA score had no significant difference between the groups. CONCLUSION: In the tibial sagittal plane, there was a significant difference in the implantation accuracy, but its difference did not affect the clinical outcomes. Both navigation systems have clinically acceptable implantation accuracy.

IgA Vasculitis Developed as an Adverse Effect of Tofacitinib Taken for Rheumatoid Arthritis.

Tofacitinib is a new small-molecule inhibitor of the JAK/STAT signaling pathway used to treat rheumatoid arthritis. We herein report a case of IgA vasculitis apparently caused by tofacitinib. A 67-year-old woman with rheumatoid arthritis developed IgA vasculitis after taking tofacitinib for 6 months. She presented with proteinuria and purpura of the lower extremities. Biopsy specimens from her skin and kidney were compatible with IgA vasculitis. Following termination of tofacitinib, the patient completely recovered from the IgA vasculitis. Drug-induced IgA vasculitis has been previously described for anti-tumor necrosis factor-(TNF)α therapies, but this is the first report of this adverse effect with anti-JAK therapy.

A Case Report of Isolated Cuboid Nutcracker Fracture.

Isolated cuboid fractures are very rare, since they typically occur in combination with midfoot fractures or dislocations. A 61-year-old man presented at our hospital with pain and swelling on the outside of his right foot. The lateral column of his right foot was shortened by approximately 6.5 mm on X-ray. CT showed displacement of the joint surface between the cuboid and the fourth metatarsal, with a 3.5 mm depression. An MRI revealed no other injuries. Based on these findings, we diagnosed the patient with an isolated nutcracker fracture of the cuboid. Using a 1.9 mm arthroscope, we examined the Lisfranc joint. Then the depressed fragments were elevated until the regular joint line was restored. A bone biopsy needle was then used to fill in the large defect with artificial bone. In this case, we did not plate the fracture. Six months after surgery, patient could walk without pain. We report a very rare case of isolated nutcracker fracture of the cuboid. In addition, we suggest our new treatment plan of this fracture.

Irreducible plantar dislocation of the interphalangeal joint of the great toe due to an accessory sesamoid bone: a case report.

INTRODUCTION: Great toe dislocation frequently occurs at the metatarsophalangeal joint. However, an irreducible dislocation of the great toe interphalangeal (IP) joint due to an accessory sesamoid bone is relatively unusual. CASE REPORT: A 23-year-old woman suffered a dislocated IP joint of the left great toe. The distal phalanx was plantar subluxated, and the articular surface was misaligned. Ultrasound, magnetic resonance imaging, and computed tomography images did not indicate any factors inhibiting reduction. In addition, the sesamoid bone at the IP joint was found to be rotated in the long-axis direction. The sesamoid bone of the IP joint was hooked from the distal direction and occupied the intercondylar area. IP joint of the left great toe was flexed and the distal phalanx was pushed toward the proximal phalanx during reduction locking with fluoroscopic guidance under local anesthesia, and the dislocation was successfully reduced. DISCUSSION: The sesamoid bone at the IP joint is anatomically located dorsal to the flexor hallucis longus tendon and volar plate. The sesamoid bone fitted exactly in the distal intercondylar area. The sesamoid bone in our patient could be rotated by forcible plantar flexion of the IP joint displaced proximally and hooked into the intercondylar area from the proximal aspect. Then, the distal phalanx was pulled proximally through the volar plate. This is the first report on a plantar dislocation of the IP joint.

Transverse incision advantages for total knee arthroplasty.

BACKGROUND: If a transverse incision can be safely used for total knee arthroplasty (TKA), decreases in scar formation, reduced injury of the infrapatellar branch of the saphenous nerve and improved kneeling motion will be observed. METHODS: We evaluated 95 patients (101 knees) on whom primary TKA was performed with follow-up of more than 2 years. A longitudinal incision was used for the first 40 knees and a transverse incision for the remaining 61 knees. Operation time, blood loss, complications and Knee Society Score were evaluated. Wound lengths, widths and the Manchester Scar Scale (MSS) were measured 1 year after the surgery. Further examination evaluated sensory disturbances and whether kneeling was possible. RESULTS: The complication rate in both groups was almost the same. The wound lengths measured at a 90° knee-flexed position were about 15 cm with no significant difference between the groups. The average width measured at a maximum area was significantly smaller in the transverse group than in the longitudinal group. MSS of the transverse group was also significantly lower than that of the longitudinal group. Sensory disturbance was found to be significantly smaller in the transverse group than in the longitudinal group both in subjective and objective evaluation at 1 year after surgery. When a transverse incision was used, the direction of the incision corresponded to the running direction of the saphenous nerve, and thus, we were able to reduce sensory disturbances on the distal lateral side of the knee joint. The transverse group (70.4%) performed significantly better than the longitudinal group (40.6%) at kneeling motion. CONCLUSIONS: We showed that making a transverse incision is a safe method, resulting in a reduction of scar formation and less dysfunction of the infrapatellar branch of the saphenous nerve, and improvement of kneeling motion.

Bilateral total knee arthroplasty after spontaneous osseous ankylosis in rheumatoid arthritis.

Total knee arthroplasty (TKA) was carried out on both knee joints for spontaneous bony ankylosis due to rheumatoid arthritis (RA). Preoperative fixation angles were 40 degrees . First, the peroneal nerve was released prior to TKA. Quadriceps snip was performed to evert the patella laterally. Bilateral TKAs were carried out using a stabilized prosthesis. The results showed full extension to 70 degrees flexion at 3 years after the surgery. Absence of pain, maintenance of stability, and walking ability were achieved, without any significant complication. Total knee arthroplasty following takedown of a spontaneous ankylosed knee is an effective procedure under appropriate knee conditions.