Association of Pars Defect Type with Clinical Outcome after Smiley Face Rod Methods for Terminal-Stage Spondylolysis.

Introduction: The smiley face rod method is an effective treatment for symptomatic terminal-stage spondylolysis. However, the risk factors for treatment failure are unknown. We investigated the association of pars defect type with the treatment outcomes of this method. Methods: We retrospectively examined data from 34 patients (18.0±6.7 years) with terminal-stage spondylolysis who underwent surgery using the smiley face rod method. The mean follow-up period was 44.9±21.4 months. The patients were divided into 2 groups: pars defect without bone atrophy or sclerosis (group A; 18 patients), and with bone atrophy and sclerosis (group B; 16 patients). We evaluated and compared the visual analog scale (VAS) score for back pain, bone union rate, and time to return to preinjury athletics level between the groups. Fisher exact and paired t tests were used to compare the variables between groups. The VAS score between the groups was compared using a 2-factor repeated-measures analysis of variance. Results: Within groups, the VAS score was significantly different over time (p<0.001). The VAS scores between groups were not significantly different. Patients in group A had a significantly higher bone union rate per pars at 6 months (group A, 65.7%; and group B, 37.5%, p=0.028) and 24 months after surgery (group A, 97.1%; and group B, 75.0%, p=0.011). All patients returned to their respective sports, and no significant differences were observed in the time to return to preinjury athletics level between the groups (p=0.055). Conclusions: The type of pars defect are associated with bone union after the smiley face rod method, but have little effect on postoperative symptoms.

Combined Transforaminal Lumbar Interbody Fusion and Smiley Face Rod Technique Using Dual-Headed Pedicle Screws for L4 Isthmic Spondylolisthesis and L5 Spondylolysis.

Spondylolysis with pseudarthrosis may be treated surgically by repairing the spondylolysis using the smiley face rod (SFR) technique. The SFR technique can avoid adjacent segmental disease caused by transforaminal lumbar interbody fusion (TLIF), which is one of the main surgical techniques to treat isthmic lumbar spondylolisthesis. A 59-year-old woman had been playing softball since she was 12 years old and was a member of a prefectural representative team. She sought treatment because of numbness in her left lower limb and difficulty playing softball. Despite conservative treatment for a year, her symptoms did not improve. Physical examination revealed decreased patellar tendon reflexes and numbness and pain from the front of the thigh to the lower leg without muscle weakness. Imaging showed L4 isthmic spondylolisthesis with Meyerding classification grade 2 anterior slip and L5 spondylolysis with pseudarthrosis. We diagnosed L4 radiculopathy caused by L4/5 foraminal stenosis and L4 isthmic spondylolisthesis with L5 spondylolysis. She underwent surgery combining the TLIF of L4/5 and the SFR technique of L5 using dual-headed pedicle screws that can fix two types of rods with L5 pedicle screws. Three months after surgery, fusion between L4/5 and fusion of the L5 pars cleft were confirmed. She resumed sports, and one year postoperatively, she was able to participate in softball games. Two years postoperatively, she could bat, run, and play defense without adjacent segmental disease. Two-segment TLIF increases adjacent segmental disease more than single-segment TLIF. Because the L5 spondylolysis had not slipped, we chose the SFR technique to preserve mobility at L5/S1. The dual-headed pedicle screw fastens two-type rods at the head of the pedicle screw, making it a suitable design for this procedure.

A Novel Technique for Pars Defect Direct Repair with a Modified Smiley Face Rod for Spondylolysis and Isthmic Spondylolisthesis.

Introduction: Lumbar spondylolysis is a common fatigue fracture of the pars interarticularis of the lamina of the lumbar spine in adolescent athletes presenting with pars clefts. Some pseudarthrotic lumbar spondylolysis causes low back pain or radiculopathy. This study presents a case of pseudarthrotic lumbar spondylolysis that was successfully treated using a modified smiley face rod technique. Technical Note: We developed a modified smiley face rod technique, which places pedicle screws in the lateral edge of the pedicle to preserve the erector spinae muscles and inserts a U-shaped rod between the spinous processes to preserve the supraspinous ligament. When a U-shaped rod penetrates the interspinous ligament subcutaneously, the resection of the supraspinous ligaments can be avoided. When the screw head is positioned more anterolaterally, a compression force is applied perpendicular to the surface of the pars cleft by rod clamping. This intrasegmental fusion technique preserves the mobile segment and simultaneously repairs the pars cleft. It is less invasive and more appropriate than interbody fusion for young athletes to avoid the possibility of future adjacent segment disorders. Conclusions: This is a minimally invasive procedure that can easily achieve bone fusion and should be introduced for patients who are suffering from the symptoms of pseudarthrotic lumbar spondylolysis.

A Technical Pitfall of Decompression with Direct Repair of a Ragged Edge Using the Smiley-Face Rod Method†:†A Case Report.

The smiley-face rod method has been reported to be a successful technique for reducing slippage and repairing pars defects in lumbar spondylolisthesis. However, we encountered a patient who developed right L5 radiculopathy with muscle weakness after use of the smiley-face rod method. The patient was a 19-year-old female judo player who had undergone direct repair surgery using the smiley-face rod method for terminal-stage lumbar spondylolysis. Postoperatively, she developed paresthesia on the lateral side of the right thigh with weakness of the right tibialis anterior and extensor hallucis longus. Computed tomography showed right foraminal stenosis at L5 with the floating lamina shifted ventrally and apophyseal ring fracture. In this case, the spondylolysis fracture angle differed between the left and right sides, with the fracture line on the right side running more sagittally. As a result, the floating lamina was shifted ventrally on the right side by compression and the right L5 intervertebral foraminal space was narrowed due to the ventral shift in the floating lamina and the apophyseal ring bone fragment. The shape of the fracture line should be examined carefully before surgery to avoid this technical pitfall. J. Med. Invest. 69 : 308-311, August, 2022.

Direct reduction and repair of spondylolysis with grade 1 slip using the smiley face rod: a case report.

Objective: Lumbar spondylolysis, caused by stress fracture of the pars interarticularis may lead to a bony defect or spondylolisthesis. In adolescents, its surgical treatment employs the smiley face rod method for direct reduction of pseudoarthrotic spondylolysis and spondylolisthesis. Clinical outcomes of this treatment have been occasionally described; however, implant removal has not been discussed previously. We present a patient with lumbar spondylolysis with grade 1 slip at the 5th lumbar vertebra (L5) per the Meyerding classification. Patient: A 14-year-old boy presented with chronic severe lower back pain. Since conservative therapy did not resolve pain or enable resuming sports activities, the smiley face rod repair was performed 7 months after the initial treatment. Result: Anterior slippage of the L5 was surgically reduced. The patient wore a brace for 3 months postoperatively, and partial bone fusion was noted 6 months postoperatively. He resumed his sports activity 8 months postoperatively, and absolute bone fusion was confirmed 18 months postoperatively. Implant removal was performed 3 years postoperatively. Grade 1 slip was corrected with absolute bone fusion, and long-term follow-up revealed good results in terms of healing and rehabilitation. Conclusion: Smiley face rod method that allows for implant removal after bone fusion is suitable for adolescents.

Consecutive double-level lumbar spondylolysis successfully treated with the double "smiley face" rod method.

We report a case of double-level lumbar spondylolysis at L4 and L5 that was successfully treated with the double "smiley face" rod method. A healthy 29-year-old man who presented with a 6-year history of chronic low back pain was referred to us for surgical treatment. Plain radiographs and computed tomography of the lumbar spine revealed bilateral pars defects at L4 and L5 without slip or scoliosis. The patient underwent direct repair of the pars defects using the double smiley face rod method at L4 and L5. There were no intraoperative or postoperative complications, and the patient had improved clinically by 1 year after surgery. The low back pain was completely disappeared and visual analog scale was 0. He restarted tennis again as the recreational level. While several techniques for direct repair of lumbar spondylolysis have been described, this is the first report of the double smiley face rod method being used to repair the consecutive double-level lumbar spondylolysis. J. Med. Invest. 67 : 202-206, February, 2020.

The clinical outcome of the treatment of isthmic spondylolysis with Smiley face rod fixation system / 中国脊柱脊髓杂志

Objectives:To investigate the clinical outcome of Smiley face rod fixation system for lumbar isthmic spondylolysis.Methods:From January 2016 to June 2017,18 patients with isthmic spondylolysis were treated with smiley face screw-rod fixation system.There were 13 males and 5 females,with an average age of 28.2±3.2(25-32) years old.The average disease duration was 16.3±5.7(7-24) months.L5 isthmic spondylolysis was involved in all cases.All patients had been followed up at 3 months and 1 year after surgery.The preoperative and postoperative visual analogue scale(VAS) and Oswestry disability index(ODI) were compared.The X-ray and CT scan were evaluated to analyze the change of range of motion in the lumber spine and the bony fusion rate.Results:The mean operation time was 90.0±24.1 minutes.The average blood loss was 140±15ml.The average follow-up was 18.5±5.0 (12-24) months.The VAS at 3 months after operation was 3.0±1.2,and the ODI was (17.2±4.5)％ respectively,which showed significant differences compared with the preoperative ones[7.3±2.5 and (67.0±15.1)％](P＜0.05).The VAS and ODI at 1 year after operation were 1.0± 0.6 and (9.1±5.3)％,which showed significant differences compared with 3 months postoperation(P＜0.05).The range of motion between L5 and S1 was 13.1°±2.1° and the incidence of lumbar instability was 83.3％(15/18) preoperatively;it was 9.3°±1.6° and 11.1％(2/18) postoperatively,and there was statistic difference(P＜0.05).All patients achieved bone fusion in the isthmic defect 1 year after operation.Conclusions:The Smiley face rod fixation is a reliable treatment for lumbar spondylolysis with the advantage of minimal invasive,less nerve interference,and to restore normal anatomical structure,maintain the lumbar spine stability.

Direct reduction and repair of spondylolysis with grade 1 slip using the smiley face rod: a case report / Journal of Rural Medicine

Objective: Lumbar spondylolysis, caused by stress fracture of the pars interarticularis may lead to a bony defect or spondylolisthesis. In adolescents, its surgical treatment employs the smiley face rod method for direct reduction of pseudoarthrotic spondylolysis and spondylolisthesis. Clinical outcomes of this treatment have been occasionally described; however, implant removal has not been discussed previously. We present a patient with lumbar spondylolysis with grade 1 slip at the 5th lumbar vertebra (L5) per the Meyerding classification.Patient: A 14-year-old boy presented with chronic severe lower back pain. Since conservative therapy did not resolve pain or enable resuming sports activities, the smiley face rod repair was performed 7 months after the initial treatment.Result: Anterior slippage of the L5 was surgically reduced. The patient wore a brace for 3 months postoperatively, and partial bone fusion was noted 6 months postoperatively. He resumed his sports activity 8 months postoperatively, and absolute bone fusion was confirmed 18 months postoperatively. Implant removal was performed 3 years postoperatively. Grade 1 slip was corrected with absolute bone fusion, and long-term follow-up revealed good results in terms of healing and rehabilitation.Conclusion: Smiley face rod method that allows for implant removal after bone fusion is suitable for adolescents.