The influence of surgical stabilization of the lumbar spine on the walk ability in patients with degenerative spondylolisthesis

Uvod: Ledvena hrbtenica je podvrţena degenerativnim procesom, ki se vedno prično v medvretenčni ploščici. Ob zmanjšani višini medvretenčna ploščica izgubi fiziološko prisotno prednapetost, pride lahko do prekomernih premikov gibalnega segmenta, zdrsa vretenca ali celo do nestabilnosti. Naravni potek degenerativne spondilolisteze ni ugoden, do spontane stabilizacije ne pride, tako da je zdravljenje večinoma operativno. Najpomembnejša simptoma, ki sta razlog, da se bolnik odloči za operacijo, sta mehanična bolečina v kriţu in zmanjšana sposobnost hoje. Namen: Objektivno smo ţeleli oceniti, koliko so pacienti tri mesece po fiksaciji ledvene hrbtenice sposobni prehoditi v šestih minutah. Ugotoviti smo ţeleli, kakšno je funkcijsko stanje in kakšna je intenziteta bolečine pacientov tri mesece po operaciji, in vse parametre primerjati s tistimi pred in nekaj dni po operaciji. Metode dela: Raziskava je bila izvedena na Ortopedski kliniki, UKCL. V raziskavo je bilo vključenih 24 pacientov, starih med 40 in 77 let, s primarno diagnozo eno- ali dvonivojske degenerativne spondilolisteze s spinalno stenozo ali brez nje. Opravljena je bila eno- ali dvonivojska pedikularna fiksacija z zatrditvijo med telesi vretenc. Pacienti so v treh časovnih obdobjih – pred operacijo, tri do štiri dni po operaciji in tri mesece po operaciji – opravili šestminutni test hoje, izpolnili vprašalnik Oswestry index nezmoţnosti in modificiran Roland-Morrisov vprašalnik. Prav tako so izpolnili vprašalnik prepričanja o izogibanju zaradi strahu pri telesnih aktivnostih oziroma pri delu ter ocenili intenziteto bolečine v hrbtu in nogi z vidno analogno lestvico. Rezultati: Mediana prehojene razdalje pri šestminutnem testu hoje se je tri mesece po operaciji, v primerjavi s predoperativnim obdobjem, povečala za 92,5 m (p = 0,004). Mediana intenzitete bolečine v hrbtu se je tri mesece po operaciji v primerjavi s predoperativnim stanjem zmanjšala za 2,5 točke po vidni analogni lestvici (p = 0,001), intenziteta bolečine v nogi pa za 3,5 točke (p = 0,002). Ocena funkcijske nezmoţnosti se je tri mesece po operaciji v primerjavi s predoperativnim obdobjem izboljšala pri oceni, merjeni z vprašalnikom Oswestry indeks nezmoţnosti (p = 0,004), in pri oceni, merjeni z modificiranim Roland-Morrisovim vprašalnikom (p = 0,001). Razlike pri oceni nezmoţnosti zaradi strahu pred aktivnostjo in pred delom po treh mesecih niso bile statistično pomembne. Razprava in zaključek: Tri mesece po operaciji degenerativne spondilolisteze smo ugotovili statistično pomembno podaljšanje prehojene razdalje v šestih minutah, zmanjšanje bolečine in izboljšanje funkcijskega stanja. Rezultati raziskave kaţejo tudi, da je za boljše funkcijsko stanje tri mesece po operaciji potrebna dobra kontrola bolečine v zgodnjem pooperativnem obdobju. Ključne besede: degenerativna spondilolisteza, fiksacija ledvene hrbtenice, šestminutni test hoje, merilna orodjaIntroduction: The lumbar spine is subject to the degenerative processes, which always begins first in the intervertebral disc. Loss of physiological preload decreases disc height resulting in excessive movements of the motion segment, slipping of the vertebrae or even instability. Natural course of the degenerative spondylolisthesis is unfavorable, spontaneous stabilization does not occur, treatment is mostly surgical. Most important symptoms forcing a patient to surgery are mechanical back pain and decreased walking ability. Purpose: Aim of the study was to assess how far the participnts are able to walk in six minutes three months after lumbar spine fixation. We wanted to determine pain level and functional status of subjects three months after surgery and compare them to the same parameters obtained pre and few days postoperatively. Methods: The study was carried out at the Dept. of Orthopedic Surgery, UMCL. The study included 24 participants aged between 40 and 77 with primary diagnosis of one or two-level degenerative spondylolistesis with or without spinal stenosis. Surgery consisted of one or two-level instrumented interbody fusion. Participants were assessed before the surgery, three to four days postoperatively and three months after surgery. They completed a Six Minute Walk Test, filled out a Oswestry Disability Index, Modified Roland Morris Disability Questionnaire, Fear avoidance of physical activity questionnaire, Fear avoidance of work questionnaire and assessed back and leg pain with a Visual Analogue Scale. Results: The median distance measured with a Six Minute Walk Test increased by 92.5 m (p=0.004) three months after surgery in comparison to the preoperative period. The median back pain decreased by 2.5 points of Visible Analogue Scale three months postoperatively in comparison to the preoperative pain level (p=0.001) and leg pain decreased by 3.5 (p=0.002). The assessment of functional disability measured with the Oswestry Disability Index and Modified Roland Morris Disability showed significant improvement (p=0.004 and p=0.001), respectively three months after surgery compared to the pre-operative period. The differences in the assessment of disability due to fear of activity and work were not statistically significant. Discussion and conclusion: Three months after surgery for degenerative spondylolistesis significant improvement was observed in the walking distance assessed with Six Minute Walk Test. In addition, functional status improved while back and leg pain decreased significantly. Results of the study indicate that better functional status could be anticipated with better postoperative pain control. Key words: degenerative spondylolisthesis, instrumented interbody fusion, Six Minute Walk Test, measuring tool