An intraoperatively moulded PMMA prostheses like spacer for two-stage revision of infected total knee arthroplasty

We report a series of 16 consecutive total knee arthroplasty (TKA) revision procedures for deep infection, treated with a newly developed intraoperatively moulded PMMA cement-prostheses-like spacer (CPLS). The standard treatment consisted of a two-stage protocol with initial explantation of the infected components combined with radical debridement, followed by implantation of a temporary cement spacer and final reimplantation of a new TKA. A sterilizeable Teflon tapered aluminium mould was developed for production of a custom made CPLS during the intervention. Stable implantation of the CPLS was achieved with a second cementation, allowing for correct alignment and ligament balancing. The spacer remained 3.5 months on average until reimplantation of a TKA occurred. At time of reimplantation, patients had an average KSS score of 84.44 points with an average flexion capacity of 102°. There was no recurrent infection during the study period of minimum 2 years. With this new technique, a low friction articulation with good stability, high comfort and a better range of motion compared to handcrafted spacers was achieved. The use of this spacer is a time sparing, cheap and convenient option in 2-stage TKA revision.

Dystonic movement disorders and spinal degenerative disease

The occurrence of degenerative spinal disease subsequent to dystonic movement disorders has been neglected and has received more attention only recently. Spinal surgery is challenging with regard to continuous mechanical stress when treatment of the underlying movement disorder is insufficient. To characterize better the particular features of degenerative spinal disease in patients with dystonia and to analyze operative strategies, we reviewed the available published data. Epidemiologic studies reveal that degenerative spinal disorders in patients with dystonia and choreoathetosis occur much earlier than in the physiological aging process. Dystonic movement disorders more often affect the spine at higher cervical levels (C(2-5)), in contrast to spinal degeneration with age which manifests more frequently at the middle and lower cervical spine (C(5-7)). Degenerative changes of the cervical spine are more likely to occur on the side where the chin is rotated or tilted to. Various operative approaches for treatment of spinal pathologies have been advocated in patients with dystonic movement disorders. The available data do not allow making firm statements regarding the superiority of one approach over the other. Posterior approaches were first used for decompression, but additional anterior fusion became necessary in many instances. Anterior approaches with or without instrumented fusion yielded more favorable results, but drawbacks are pseudarthrosis and adjacent-level disease. Parallel to the development of posterior fusion techniques, circumferential surgery was suggested to provide a maximum degree of cord decompression and a higher fusion rate. Perioperative local injections of botulinum toxin were used initially to enhance patient comfort with halo immobilization, but they are also applied in patients without external fixation nowadays. Treatment algorithms directed at the underlying movement disorder itself, taking advantage of new techniques of functional neurosurgery, combined with spinal surgery have recently been introduced and show promising results.