Clinical Features And Surgical Treatment Of Andersson Lesion Complicating Ankylosing Spondylitis

Objective:To probe into the surgical treatment for ankylosing spondylitis combined with Andersson lesion through retrospective research.Methods:Retrospective analysis of the clinical features and treatments of patients with Andersson Lesion who underwent surgery in our hospital from 2010 to 2017.Nine patients were enrolled in our study,all of whom were complained of back pain.The patients,composed of seven males and two females,with an average of 43 years old(range from 25 to 56).The 9 patients had an AS history of 5～30(14.7±6.7)years and has been diagnosed with Andersson Lesion for 1～15(6.1±4.9)years.The preoperative,postoperative and final follow-up imaging data including X-ray,CT,MRI images of all cases were collected and the imaging findings and clinical manifestations of 9 patients were recorded and analyzed.Indicators such as preoperative and postoperative Visual Analogue Scale,Global Kyphosis,Local Kyphosis were analyzed.Operation time and blood loss during surgery were recorded,and clinical efficacy was evaluated by the Visual Analogue Scale.All patients received all-posterior approach surgical treatment and postoperative tissues were sent for bacterial culture,acid-fast bacilli culture and pathological biopsy.Results:All patients complained of low back pain and kyphosis.Pain is aggravated when standing or moving and relieved when lying down.Among the nine patients found were ten Andersson Lesions,including six cases of transdiscal type and three cases of transvertebral type,wherein two cases of T11/12 segments,one case of T10/11,L1/2,L2/3 segments,one case of T9,T10,T12 vertebral bodies and one case of L1/2 and L2/3 segments were both implicated,and one d-typed case,five e-typed cases and three cases unsuitable for this type were involved.All patients were positive in HLA-B27 and ESR,and eight were positive in CRP.According to the X-ray examination,besides the typical symptoms of bamboo joint vertebra,ossification of paravertebral ligament and kyphosis of spinal physiological curve in Ankylosing Spondylitis,Andersson Lesion also manifested itself in osteolytic lesion,reactive ossification and widening or narrowing of intervertebral space at the lesion site.For some patients with occult and non-performance on X-ray films,irregular bone destruction and intervertebral space vacuum sign could be found in CT scans.The scope of lesions and posterior appendages can be clearly defined for vertebral body type lesions.Magnetic resonance examination can directly find intervertebral disc lesion and surrounding soft tissue signal changes.And for cases when the range of lesions and posterior appendages of vertebral body lesions could be determined,MRI could directly detect intervertebral disc lesions and changes in peripheral soft tissue signals.All patients underwent surgical treatment in our hospital.The operation time was 296.2±88.1 minutes,the bleeding volume was 822.2±396.2 during the operation,and the average hospitalization time was 1817 days.The postoperative follow-up time averaged 32 months(12-103 months).The preoperative VAS score was 7.1±0.9,and the postoperative VAS score was 0.6±0.5.The preoperative GK was 44.1±19.90,the postoperative GK was 19.1+9.70,the average correction degree was 25.0±16.9°,and the average correction rate was 43.3%.The preoperative LK of the lesion was 27.0±13.4°,the postoperative LK of the lesion was 17.3±10.8°,the average correction degree was 9.7±8.40°,and the average correction rate was 64.1%.Postoperative VAS score,GK,and LK of the lesion were significantly improved compared with those before the operation(P<0.01).No aerobic/anaerobic bacteria,fungi or acid-fast bacilli were detected in the intraoperative tissue culture.Pathological results suggest hyperplasia of fibrous granulation tissue,degenerated cartilage tissue,and necrotic bone tissue.One patient developed pneumonia after surgery and recovered after anti-infection treatment,this patient underwent revision surgery due to pedicle screw loosening caused by severe osteoporosis.One patient had dural tear during the surgery but showed no symptoms.All patients achieved solid fusion at the last follow-up,and no internal plant complications such as loosening,fracture,displacement or sinking of the internal implant was observed.Conclusion:Andersson Lesion,a lesion that may be associated with inflammation and trauma,clinically can be diagnosed in combination with its clinical characteristics and imaging manifestations.Conservative treatment is modestly effective,and surgical treatment is the main approach.Debridement of nidus,stabilization of spine,decompression and correction of deformity are the keys to surgical treatment for Andersson Lesion,and all-posterior approach surgery can achieve satisfactory results.