Factors associated with failure of bony union after conservative treatment of acute cases of unilateral lumbar spondylolysis

Abstract

Background If bone union is expected, conservative treatment is generally selected for lumbar spondylolysis. However, sometimes conservative treatments are unsuccessful. We sought to determine the factors associated with failure of bony union in acute unilateral lumbar spondylolysis with bone marrow edema including contralateral pseudarthrosis. Methods This study targeted unilateral lumbar spondylolysis treated conservatively in high school or younger students. Conservative therapy was continued until the bone marrow edema disappeared on MRI and bone union was investigated by CT. We conducted a univariate analysis of sex, age, pathological stage, lesion level complicating the contralateral bone defect, lesion level, and intercurrent spina bifida occulta, and variables with p < 0.1 were considered in a logistic regression analysis. An item with p < 0.05 was defined as a factor associated with failure of bony union. Results We found 92 cases of unilateral spondylolysis with bone marrow edema and 66 cases were successfully treated conservatively. Failure of bony union in unilateral lumbar spondylolysis with bone marrow edema was associated with progressive pathological stage (p = 0.004), contralateral pseudarthrosis (p < 0.001), and L5 lesion level (p = 0.002). The odds ratio was 20.0 (95% CI 3.0–193.9) for progressive pathological stage, 78.8 (95% CI 13–846) for contralateral pseudarthrosis, and 175 (95% CI 8.5–8192) for L5 lesion level. Conclusions Conservative therapy aiming at bony union is contraindicated in cases of acute unilateral spondylolysis when the pathological stage is progressive, the lesion level is L5, or there is contralateral pseudarthrotic spondylolysis.

Minimally Invasive Screw Fixation of Non-Pseudoarthorotic Lumbar Spondylolysis for Early Return to Sports

“…Although this case was a recurrence after conservative treatment, we believe that internal fixation will eliminate the risk of recurrence and allow the patient to compete without worrying about recurrence in the future. In addition, it has been reported that the results of conservative treatment for contralateral pseudoarthrosis in bilateral lesions are very poor [20]. Therefore, we believe that internal fixation of the unilateral lesion to ensure bone union may stop the negative cycle of fractures and pseudoarthrosis.…”

Characteristics of Adult-Onset Acute Lumbar Spondylolysis Treated Conservatively

“…6 in our study, the bone union rate and the treatment period did not differ so much between adolescents and adults. In a previous study 16) , patients with bilateral acute spondylolysis were excluded, and some patients exhibited pseudarthrosis lesions on the contralateral side, which negatively impacts bone union [17][18][19] ; these factors prevent simple comparisons between these studies. Nonetheless, for adult-onset acute spondylolysis with bone edema, conservative therapy is probably as effective as during adolescence with regard to achievement of bone union.…”

Conservative Treatment and Unfavorable Factors to Bone Healing of “Pre-lysis”-Stage Lumbar Spondylolysis in Adolescents

“…Because most patients are referred to our hospital by their primary care physicians for a comprehensive adolescent examination, MRI is used in all cases, except those involving obvious trauma, as it has previously been reported to be useful for early diagnosis and prevention of missed lesions [ 4 , 9 ]. Furthermore, in cases where MRI shows high-intensity changes within the pedicle, CT is performed because bone fusion rates in lumbar spondylolysis vary greatly depending on the stage (e.g., 94% in early stage, 80% in progressive stage, and 0% in terminal stage), and stage diagnosis can only be performed by CT, as many reports have shown [ 1 , 3 , 5 , 7 , 8 , 10 , 11 ].…”

“…stress reaction have been proposed as a preliminary stage of fracture when no fracture line is observed on CT but intensity changes are apparent on MRI. In these cases, the bone healing rate has been reported to be nearly 100% [1,[5][6][7][8]. However, no detailed studies of pre-lysis-stage lesions have been reported.…”

“…This stage is even earlier than the traditional "early stage" and called the "pre-lysis" or "very early" stage, as proposed by Tatsumura and others [5,6]. Prelysis lesions have a bone healing rate of nearly 100% with conservative treatment; however, there are few reports on their characteristics and conservative treatment outcomes [6][7][8]. This study aimed to evaluate the clinical outcomes and factors unfavorable to bone healing of the conservative treatment of pre-lysis-stage lumbar spondylolysis.…”