New treatment of patellar instability after total knee arthroplasty: A case report and review of literature

BACKGROUND Patellar instability is an uncommon complication after total knee arthroplasty(TKA).Partial lateral patella facetectomy(LPF)with lateral retinaculum release treatment of patellar instability is rarely reported.CASE SUMMARY We present a case of patellar instability 8 mo after primary TKA.Treatment of this complication was adapted to address the cause of the dislocation.To eliminate patellar instability,we restored the vastus medialis and performed LPF with lateral retinaculum release.We achieved normal patellar tracking.Clinical and radiographic evaluations at the 1-year postoperative follow-up were satisfactory.CONCLUSION LPF with lateral retinaculum release represents a promising option to restore central patellar tracking in patients with patellar instability after TKA in cases without component malposition.

Far Lateral Disc Prolapse: Surgical Options in Limited Resources Centers

Far lateral disc prolapse accounts for 6.5% to 12% of all lumbar disc prolapses. Surgical options include open laminectomy with discectomy, microscopic and endoscopic excision of the prolapsed disc. Some of these options may not be available in limited resources centers. We will highlight the effectiveness of various surgical options. Twenty patients with foraminal and extraforaminal lumbar disc prolapse were operated upon from January, 2015 to June, 2016 in the neurosurgical departments of Cairo and Fayoum Universities in Egypt by different modalities (open laminectomy with discectomy, microscopic and endoscopic discectomy). Seventeen patients had foraminal disc prolapse and only three patients had extraforaminal disc prolapse. Twelve patients were operated by conventional laminectomy approach. Microscope was used in four patients and four patients were operated endoscopically. Excellent radicular pain improvement was achieved in 15 cases (75%) including all of the laminectomy groups. Conventional laminectomy and discectomy in far lateral disc prolapse remains an excellent option especially in limited resources centers. Although building up experience with other surgical modalities is mandatory.

The rotational stability of lumbar spine following unilateral multilevel resection of spinal posterior structure: a biomechanical study

The experiment was designed to evaluate the influence of unilateral resection of the spinal posterior structure on the rotational stability of multilevel lumbar spine. Methods The experiment was carried out with 7 fresh cadaver lumbarspine specimens (L1 -S1 ). By gradually resecting unilateral posterior structure, six models were made, from unilateral laminectomyto total laminectomy. A three-dimensional movement device, with the maximum loading of 10.0 N. m, was used to produce rotational movement. Results The range of motion increased significantly after total laminectomy and bilateral medial 1/3 facetectomies. Conclusion Besides zygapopyseal joints, laminae and posterior ligaments play an important role in restricting lumbarspine rotational movement.