RESUMO
Background and Objective: to evaluate surgical management of spondylolisthesis through posterior approach using different instrumentation including fixation by pedicular screws/rods with posterolateral arthrodesis, posterior interbody titanium threaded [stand alone] cages as PLIF or pedicular system and posterior different types of cages [titanium or carbon] to bold the bony interbody fusion
Patients and Methods: sixty patients with lumbar spondylolisthesis were classified into three groups: Group A [n=20] was fixed by pedicular-screws/rods fixation with posterolateral arthrodesis; group B [n=20] had posterior interbody titanium threaded [stand alone] cages as PLIF; and group C [n=20] was fixed by pedicular system and posterior different types of cages [titanium or carbon]. All patients underwent serial clinical evaluations at regular 3-month intervals between the 3rd and the 12th postoperative months. At the second year they were examined at 6-month intervals. Functional disability was measured by the Oswestry low back pain disability questionnaire. Radiological evaluation was done with 6 months interval for 2 years to evaluate: fusion status; hardware status [correct placement or failure]; anatomical correction [horizontal displacement, angular displacement; disc height]; and instability and degenerative . changes on adjacent levels. All surgical problems were recorded including intraopertaive, early and late postoperative ones
Results: excellent postoperative Brodsky scores of pain were reported by 50%, 55% and 60% in group A, B and C respectively, showing a significant difference to preoperative scores in each group. The success rates were 80%, 85% and 90% in group A, B and C respectively. Correction Rate [CR] of preoperative symptoms was 90% in group C, 85% in group B and 75% in group A. Obvious fusion was detected in 18 cases [90%] of group C, 16 cases [80%] of group B and 14 cases [70%] of group A, i.e. the fusion rate after circumferential fusion is higher and reliable than that in stand-alone procedure. Immediately after surgery, there was a significant reduction in horizontal displacement [HD], and angular displacement [AD], and a significant increase in disc height [DH] in all groups, which still significant after 2 years in group B and group C only. There was non significant difference in the rate of complications except the significant increase in-operative time > 4 hours in group C
Conclusion: in cases of spondylolithesis grade I. and II, fixation by pedicular system and posterior different types of cages [titanium or carbon] provide a more solid mechanical construct -when compared with the pedicle screws used alone or stand alone cages. All surgical procedures are effective, although combined procedure showed better clinical outcomes if quality of life, pain improvement, and functional recovery are considered