Characteristics of Lumbar Spondylolysis in Adolescent Baseball Players: Relationship between the Laterality of Lumbar Spondylolysis and the Throwing or Batting Side.

STUDY DESIGN: A retrospective, cross-sectional study was conducted to analyze the implications of asymmetric baseball movements on the incidence of spondylolysis. PURPOSE: This study aimed to evaluate the relationship between asymmetric movements and the laterality of spondylolysis. OVERVIEW OF LITERATURE: Baseball, characterized by its asymmetric throwing and batting, may disproportionately stress one side. Lumbar spondylolysis is a frequent cause of lower back pain in young athletes, particularly those involved in activities with consistent unilateral rotations such as baseball. However, whether a link exists between the laterality in spondylolysis and the dominant throwing/ batting side or whether disparities exist between pitchers and fielders remains unclear. METHODS: The study included 85 players. Participants were divided into two groups: pitchers and fielders. The association between the laterality of spondylolysis and the throwing/batting side in the overall cohort and between the two groups was evaluated. RESULTS: Among pitchers, 16 lesions appeared on the throwing side and 32 on the nonthrowing side (p =0.029). For fielders, no notable difference was observed between the two sides (p =0.363). Furthermore, batting preference did not influence the laterality of spondylolysis in either group. CONCLUSIONS: Adolescent baseball players, particularly pitchers, exhibited a higher incidence of lumbar spondylolysis on the side opposite their throwing arm. The findings of this study highlight the significant effect of asymmetrical sporting activities on the development of spondylolysis, to which pitchers are particularly susceptible.

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.

Characteristics of lumbar spondylolysis: L5 versus non-L5.

BACKGROUND: Fifth lumbar vertebra (L5) spondylolysis has a lower bone union rate than non-L5 spondylolysis, but the reason for this is unknown. This study aimed to evaluate the differences in patient and lesion characteristics between L5 and non-L5 spondylolysis. METHODS: A total of 410 patients with lumbar spondylolysis aged 18 years or younger who were treated conservatively were enrolled. Patients and lesions were divided into L5 and non-L5 (L2-L4) spondylolysis. Factors, including sex, age, presence of spina bifida occulta, stage of the main side lesion, whether the lesion was unilateral or bilateral, presence and stage of the contralateral side lesion and treatment duration, were evaluated at the first visit and compared between the two groups. RESULTS: A total of 250 patients with 349 lesions were included. The bone union rate of L5 lesions was lower than that of non-L5 lesions (75% vs. 86%, p = 0.015). Patients with L5 spondylolysis were more likely to be male (86% vs. 66%) and younger (14.0 vs. 14.6 years) than patients with non-L5 spondylolysis. Lesions of L5 spondylolysis were more likely to be in a progressive stage (28% vs. 15%), less likely to be in a pre-lysis stage (28% vs. 43%) and more likely to be in a contralateral terminal stage (14% vs. 5.3%, p = 0.013) compared with lesions of non-L5 spondylolysis. CONCLUSIONS: L5 spondylolysis was characterised by a lower bone union rate, more males, younger age, more progressive stage and more contralateral pseudarthrosis than non-L5 spondylolysis.

Effects of Spina Bifida Occulta on Bone Union in Fifth Lumbar Spondylolysis.

Introduction: The effect of spina bifida occulta (SBO) on bone union in lumbar spondylolysis is controversial. The study aim was to assess the effect of SBO on bone union after conservative treatment of L5 spondylolysis, the most common level. Methods: The study included 191 lesions in 145 patients (mean age, 14.0 years) with conservatively treated L5 spondylolysis. We examined the relationships between bone union after conservative treatment and the number of SBOs, levels, and single or multilevel status. Fisher's exact probability test, chi-square test, and Welch's T test were performed. Results: The SBO incidence was 53%, with at least one SBO at any vertebral level. SBO at S1 (p=0.034) or S2 (p=0.0003), two SBOs (p=0.0018), and three SBOs (p=0.011) were associated with a lower bone union rate. The bone union rate was significantly lower for lesions with SBOs at both S1 and S2 than without (42% vs. 79%; p<0.0001). Conclusions: The SBO incidence in L5 spondylolysis was 53%. SBO at S1 or S2 and a higher number of SBOs were associated with lower bone union rates. In particular, the bone union rate of lesions with SBOs at both S1 and S2 was <50%.

Epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis: a single-institution experience in Japan.

BACKGROUND: Lumbar spondylolysis, a common identifiable cause of low back pain in young athletes, reportedly has a higher incidence rate in males. However, the reason for its higher incidence in males is not clear. This study aimed to investigate the epidemiological differences between the sexes in adolescent patients with lumbar spondylolysis. METHODS: A retrospective study was conducted in 197 males and 64 females diagnosed with lumbar spondylolysis. These patients visited our institution from April 2014 to March 2020 with their main complaint being low back pain, and they were followed-up until the end of their treatment. We investigated associations between lumbar spondylosis, their background factors, and characteristics of the lesions and analyzed their treatment results. RESULTS: Males had a higher prevalence of spina bifida occulta (SBO) (p = 0.0026), more lesions with bone marrow edema (p = 0.0097), and more lesions in the L5 vertebrae (p = 0.021) than females. The popular sports disciplines were baseball, soccer, and track and field in males, and volleyball, basketball, softball in females. The dropout rate, age at diagnosis, bone union rate, and treatment period did not differ between the sexes. CONCLUSION: Lumbar spondylolysis was more common in males than in females. SBO, bone marrow edema, and L5 lesions were more frequent in males, and sports discipline varied between the sexes.

Main and contralateral side stages of lesion affected bone union in the conservative treatment of adolescent lumbar spondylolysis: a multivariable analysis of 217 patients and 298 lesions in a retrospective cohort study.

BACKGROUND: Factors affecting bone union in the conservative treatment of adolescent lumbar spondylolysis remain controversial. We aimed to examine these factors along with advances in diagnostic imaging using multivariable analysis of a sufficient number of patients and lesions. METHODS: In this retrospective study, high-school-aged patients or younger (n = 514) who were diagnosed with lumbar spondylolysis from 2014 to 2021 were investigated. We included patients with acute fractures who showed signal changes around the pedicle on magnetic resonance imaging and who completed conservative treatment. The following factors were investigated at the initial visit: age, sex, level of lesion, main side stage, presence and stage of contralateral side lesion, and presence of spina bifida occulta. The association of each factor with bone union was evaluated through a multivariable analysis. RESULTS: Altogether, 298 lesions in 217 patients (174 boys and 43 girls; mean age: 14.3 years) were included in this study. Multivariable logistic regression analysis of all factors showed that the main side progressive stage was more likely associated with nonunion as compared to the pre-lysis (OR: 5.86; 95% confidence interval [CI]: 2.00-18.8; p = 0.0011) and early stages (OR: 3.77; 95% CI: 1.72-8.46; p = 0.0009). Regarding the contralateral side stage, the terminal stage was more likely to be associated with nonunion. CONCLUSION: In the conservative treatment of lumbar spondylolysis, the factors affecting bone union were the main and contralateral side stages. Sex, age, level of lesion, or spina bifida occulta had no significant effects on bone union. The main, progressive, and contralateral side terminal stages were negative predictors of bone union. Trial registration This study was retrospectively registered.

Atypical tibial fracture in breast cancer patient with bone metastasis receiving denosumab therapy: a case report and review of the literature.

BACKGROUND: Denosumab therapy is often used to reduce skeletal-related events in metastatic bone disease. On the other hand, there have been some instances of atypical femoral fracture in patients with metastatic bone disease treated with denosumab. In this case report, we describe a patient with metastatic bone disease due to breast cancer who had been using denosumab for 4 years to prevent skeletal-related events and suffered an atypical tibial fracture. CASE PRESENTATION: We report here the case of an 82-year-old Japanese woman who had received yearly intravenous denosumab for 4 years and presented with a fracture fulfilling the criteria for an atypical fracture, except for being located at the tibial diaphysis. She was found to have stage 4 breast cancer with multiple bone metastases 4 years prior. She had difficulty walking due to her tibial pain and underwent surgical treatment. Four months after surgery, the tibial fracture site exhibited bone fusion. CONCLUSION: In patients with long-term use of denosumab to prevent skeletal-related events in metastatic bone disease, it is important to be aware of shin and thigh pain and to examine for signs of atypical tibial fractures to pay attention to atypical femoral fractures.

Characteristics of Adult-Onset Acute Lumbar Spondylolysis Treated Conservatively.

Introduction: Lumbar spondylolysis typically arises during adolescence, whereas its onset in adulthood is rare. Several studies have reported incidentally identified terminal-stage spondylolysis in adults, but only one case series has investigated acute lumbar spondylolysis lesions with bone marrow edema in adults. Methods: We retrospectively investigated lumbar spondylolysis in patients aged 18 years or older. Age at diagnosis, sex, competitive sporting level, and competitive sporting discipline were investigated in each patient. The level of the affected vertebra, pathological stage, bone union, and treatment period were analyzed for each lesion. Results: The study included nine patients (eight males and one female), aged 18-22 years old, with 14 acute lumbar spondylolysis lesions. Four patients were soccer players (two professionals, and two amateurs), four were amateur track and field athletes, and one was an amateur basketball player. The affected vertebral levels were L3 in two lesions, L4 in seven lesions, and L5 in five lesions. The pathological stage was pre-lysis stage in two lesions, early stage in eight lesions, and progressive stage in four lesions. Ten lesions achieved bone union with conservative therapy. The average treatment period was 84.7 days. Conclusions: The adult-onset lumbar spondylolysis patients were young, up to their early 20s, and generally professional sportspeople performing at an elite level. Most of them were performing a sport that has been reported to have a high risk of causing lumbar spondylolysis. L4 was the most affected vertebral level in contrast to L5, which has been reported in adolescent lumbar spondylolysis. Bone union was achieved for most lesions with conservative therapy.

Treatment of Thoracolumbar Pyogenic Spondylitis with Minimally Invasive Posterior Fixation without Anterior Lesion Debridement or Bone Grafting: A Multicenter Case Study.

The usefulness of minimally invasive posterior fixation without debridement and autogenous bone grafting remains unknown. This multicenter case series aimed to determine the clinical outcomes and limitations of this method for thoracolumbar pyogenic spondylitis. Patients with thoracolumbar pyogenic spondylitis treated with minimally invasive posterior fixation alone were retrospectively evaluated at nine affiliated hospitals since April 2016. The study included 31 patients (23 men and 8 women; mean age, 73.3 years). The clinical course of the patients and requirement of additional anterior surgery constituted the study outcomes. The postoperative numerical rating scale score for lower back pain was significantly smaller than the preoperative score (5.8 vs. 3.6, p = 0.0055). The preoperative local kyphosis angle was 6.7°, which was corrected to 0.1° after surgery and 3.7° at the final follow-up visit. Owing to failed infection control, three patients (9.6%) required additional anterior debridement and autogenous bone grafting. Thus, in this multicenter case series, a large proportion of patients with thoracolumbar pyogenic spondylitis could be treated with minimally invasive posterior fixation alone, thereby indicating it as a treatment option for pyogenic spondylitis.

The relationship between spinal alignment and activity of paravertebral muscle during gait in patients with adult spinal deformity: a retrospective study.

BACKGROUND: Spinal alignment in patients with adult spinal deformity (ASD) changes between rest and during gait. However, it remains unclear at which point the compensated walking posture breaks down and how muscles respond. This study used time-synchronized electromyography (EMG) to investigate the relationship between dynamic spinal alignment and muscle activity during maximum walking duration to reveal compensation mechanisms. METHODS: This study collected preoperative three-dimensional gait analysis data from patients who were candidates for corrective surgery for ASD from April 2015 to May 2019. We preoperatively obtained dynamic spinal alignment parameters from initiation to cessation of gait using a motion capture system with time-synchronized surface integrated EMG (iEMG). We compared chronological changes in dynamic spinal alignment parameters and iEMG values 1) immediately after gait initiation (first trial), 2) half of the distance walked (half trial), and 3) immediately before cessation (last trial). RESULTS: This study included 26 patients (22 women, four men) with ASD. Spinal sagittal vertical axis distance during gait (SpSVA) increased over time (first vs. half vs. last, 172.4 ± 74.8 mm vs. 179.9 ± 76.8 mm vs. 201.6 ± 83.1 mm; P < 0.001). Cervical paravertebral muscle (PVM) and gluteus maximus activity significantly increased (P < 0.01), but thoracic and lumbar PVM activity did not change. Dynamic spinal alignment showed significant correlation with all muscle activity (cervical PVM, r = 0.41-0.54; thoracic PVM, r = 0.49-0.66; gluteus maximus, r = 0.54-0.69; quadriceps, r = 0.46-0.55) except lumbar PVM activity. CONCLUSION: Spinal balance exacerbation occurred continuously in patients with ASD over maximum walking distance and not at specific points. To maintain horizontal gaze, cervical PVM and gluteus maximus were activated to compensate for a dynamic spinal alignment change. All muscle activities, except lumbar PVM, increased to compensate for the spinal malalignment over time.

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

STUDY DESIGN: Retrospective cohort study. PURPOSE: To evaluate the clinical outcomes of the conservative treatment of "pre-lysis"-stage lumbar spondylolysis. OVERVIEW OF LITERATURE: With the widespread use of magnetic resonance imaging (MRI) for early diagnosis of lumbar spondylolysis, a new disease stage called pre-lysis has emerged, in which intensity change is observed only on MRI without a fracture line on computed tomography. This study aimed to evaluate the clinical outcomes and factors unfavorable to bone healing of the conservative treatment of pre-lysis-stage lumbar spondylolysis. METHODS: Fifty-three patients with 57 fresh pre-lysis-stage lesions who had completed conservative treatment were included in the study (40 men, 13 women; mean age, 14.3 years). We investigated the rate of bone healing and the relationship between bone healing after conservative therapy and factors such as age, sex, vertebral level, unilateral/bilateral lesions, and presence of spina bifida occulta. RESULTS: The overall bone healing rate was 95% (54/57 lesions). Bilateral lesions had a significantly lower bone healing rate than unilateral lesions (86% vs. 100%, p=0.046). There were no statistically significant differences based on age, sex, vertebral level, or presence of spina bifida occulta. CONCLUSIONS: The bone healing rate in unilateral lesions was 100%, which was significantly higher than that in bilateral lesions. It is important to detect and initiate treatment while the lesion is still unilateral, if possible.

Clinical Outcome of Sacroiliac Rod Fixation for Fragility Fracture of the Pelvis Rommens and Hoffman Classification Type IVb: Case Series.

Introduction: Fragility fracture of the pelvis (FFP), generally involving Rommens and Hoffman classification type IVb (H-shaped) requires spinopelvic fixation (SPF). We report the clinical outcome of sacroiliac rod fixation (SIRF) for FFP type IVb in a case series. Materials and Methods: In this retrospective observational study, six patients (mean age, 80.3 years; range, 74-85 years) with FFP type IVb who underwent SIRF since October 2019 and could be followed up for ≥1 year postoperatively were included. All patients were injured in low-energy falls, a patient had a femoral neck fracture, and other had a humeral neck fracture and distal radius fracture. Results: The mean (range) operative time was 135 (98-200) min, and mean blood loss was 103 (80-130) g. All patients achieved bone union in an average of 4.3 months. No implant failure or surgical site infection requiring reoperation occurred. No patient complained of iliac screw irritation or requested removal. One patient developed a T12 vertebral fracture at 3 weeks postoperatively. The mean final follow-up period was 17.8 months (13-22 months) and mean final modified Majeed Score (maximum 76 points as the items "work" and "sexual intercourse" were omitted for this study) was 71.7 (56-76). Conclusions: SIRF is a less invasive surgical technique than SPF that uses only an S1 pedicle screw and iliac screw. SIRF using the "within ring" concept showed good clinical outcome in FFP type IVb.

Internal fixation for fragility fracture of pelvis in a patient with ankylosing spondylitis.

Ankylosing spondylitis is a common inflammatory rheumatic disease with a prevalence of 0.1 %-1.4 %. The most common vertebral fractures associated with ankylosing spondylitis are cervical spine injuries due to low-energy trauma, whereas pelvic fractures are rare. Conversely, fragility fracture of the pelvis is a fracture of the pelvic ring caused by low-energy trauma with a background of bone fragility. In recent years, minimally invasive surgery for early mobilization of displaced fragility fracture of the pelvis has been reported. We report herein a case of a 91-year-old male with ankylosing spondylitis who underwent internal fixation for fragility fracture of his pelvis. He was brought to the emergency room with a complaint of pain in the right hip after a fall from a standing position at home. Computed tomography showed a fracture of the right pubis and a fracture, which crossed the sacrum from the ilium with a maximum dislocation. There was also extensive ossification of the anterior longitudinal ligament in the thoracolumbar spine and bony ankylosis of both sacroiliac joints. The diagnosis after the injury was fragility fracture of the pelvis, which complicated by ankylosing spondylitis. The fracture type did not match the Rommens and Hofmann classification criteria. Iliac intramedullary stabilization was performed in accordance with the treatment of Rommens and Hofmann classification type IIIa. The patient's pain reduced a day after the surgery, and he was able to use a wheelchair. He was able to walk with a cane two months after the surgery, and bone union was achieved four months postsurgery. Iliac intramedullary stabilization was useful in patients with atypical fractures a) that did not fit the Rommens and Hofmann classification criteria owing to the presence of ankylosing spondylitis, and b) in cases wherein strong fixation was considered necessary.

Postoperative Changes in Resting State Functional Connectivity and Clinical Scores in Patients With Cervical Myelopathy.

OBJECTIVE: Resting state functional magnetic resonance imaging (rs-fMRI) is a technique for the analyzing functional connectivity (FC) between anatomically distant brain regions at rest. The purpose of this study was to analyze postoperative FC changes in patients with compression cervical myelopathy, to evaluate their relationship with clinical scores, and to examine the changes in spinal cord function associated with brain networks. METHODS: This prospective study comprised 15 patients with cervical myelopathy who underwent planned surgery. Rs-fMRI was performed preoperatively and 6 months postoperatively with the similar protocol. Clinical function was assessed by the Japanese Orthopedic Association (JOA) score, the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the numerical rating scale (NRS). We performed a seed-based analysis, and identified the networks that changed significantly following surgery. Furthermore, we performed a correlation analysis to compare the postoperative changes in FC with clinical scores. RESULTS: Five FCs were significantly increased postoperatively; 4 were between the sensorimotor network (SMN) and other regions. We observed a significant correlation between the FC of the right SMN and the left precentral gyrus with the JOA score, the left SMN with the JOACMEQ for upper extremity function, and the left postcentral gyrus with the NRS. CONCLUSIONS: The reorganization of the sensorimotor cortex occurred postoperatively in patients with compression cervical myelopathy. In addition, each change in FC was significantly correlated with the clinical scores, thus indicating an association between the recovery of spinal cord function and plastic changes in the sensorimotor cortex.

Evaluation of dynamic spinal alignment changes and compensation using three-dimensional gait motion analysis for dropped head syndrome.

BACKGROUND CONTEXT: Dynamic kinematic evaluation of spino-pelvic alignment during gait using three-dimensional (3D) motion analysis has been proposed for adult spinal thoracolumbar deformity. That is because conventional full-spine radiographs cannot be used to evaluate dynamic factors. However, dynamic changes in spino-pelvic alignment during gait for dropped head syndrome (DHS) have not been studied using this approach. PURPOSE: This study aimed to assess the dynamic changes in spinal-pelvic alignment during gait in patients with DHS using 3D motion analysis. STUDY DESIGN: Retrospective review of collected radiographic and kinematic data. PATIENT SAMPLE: Nineteen DHS patients with neck pain and/or anterior gaze disturbance. OUTCOME MEASURES: Static spino-pelvic radiological alignment, dynamic spino-pelvic kinematic parameters and electromyogram (EMG) data. METHODS: Center of gravity of the head - C7 sagittal vertical axis (CGH-C7 SVA), C2-C7 SVA, T1 slope; cervical lordosis (CL), C7SVA, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic tilt (PT) and pelvic incidence (PI) were assessed using full-spine radiographs in a standing position to assess static spino-pelvic alignment. The 3D gait motion analysis was conducted during gait. Dynamic kinematic parameters were divided into spinal segments: cervical (C-), thoracic (T-), lumbar (L-) and pelvis (P-). Each spinal segment coronal angle to the pelvic angle, each spinal segment sagittal angle to the pelvic angle and pelvic sagittal angle to the horizontal axis were assessed as dynamic spino-pelvic kinematic parameters. Trunk and lower limb muscle activity during gait were assessed using wireless surface EMG analysis. Dynamic spino-pelvic kinematic variables and muscle activity were compared between the first walking lap and the final lap during gait analysis. The change in dynamic kinematic parameters was correlated with static radiological alignment and electromyographic muscular activity change. RESULTS: Cervical and thoracic anterior tilt increased significantly after an extended period of walking, indicating that dropped head worsened during gait. An increase of cervical anterior tilt during walking was significantly associated with decreased muscle activity in the cervical paraspinal muscles (r=-0.463, P<.05) and latissimus dorsi (r=-0.763, p<.01). Furthermore, significant correlations were found between a change in thoracic sagittal angle to pelvic angle and C7SVA (r=0.683, p<.01) and LL (r=-0.475, p<.05). This means that a larger C7SVA and smaller LL were associated with increased thoracic anterior tilt during gait. CONCLUSIONS: The 3D motion analysis for DHS showed that cervical and thoracic anterior tilt significantly increased after extended walking, resulting in worsening of dropped head. Decreased muscle activity of the neck extensor muscles during gait suggests insufficient neck extensor muscle endurance, which was associated with increased cervical anterior tilt. A greater increase in the thoracic anterior tilt during gait was found in DHS patients with a larger C7SVA and smaller LL due to insufficient thoracolumbar compensation for the dropped head. Correction of the cervical spine alone would not be sufficient to improve dropped head in cases with increased thoracic anterior tilt during gait. The results suggest that C7SVA and LL are crucial parameters in the surgical strategy for DHS.

Characteristics of recurrent cases after conservative therapy in adolescent lumbar spondylolysis.

Occasionally lumbar spondylolysis in adolescents will recur after conservative treatment. The goal of this study was to retrospectively review the conditions in which recurrence transpired in a subset of adolescent patients diagnosed with acute lumbar spondylolysis. A retrospective survey was conducted in 141 patients who had been treated for spondylolysis and had obtained bone union. Twenty subjects were selected who had recurrent lumbar spondylolysis after returning to sports activity following the initial spondylolysis treatment. There were 18 males and two females with an average age at the time of initial visit of 13.3 years and 14.1 years at the time of recurrence. The average period of initial treatment was 101 days, and the average time to recurrence after healing was 149 days. There were three cases at L3, two cases at L4 and 15 cases at L5. At recurrence, 18 patients had unilateral involvement and two patients presented with bilateral occurrence. Four cases did not achieve bony union. In this study, the recurrence rate was 13.2%. Eighty percent of cases had recurrence within six months after healing. After recurrence, 20% of the cases reached pseudoarthrosis. It is useful to take regular MRI images to detect recurrence within six months after returning to sports.

Union evaluation of lumbar spondylolysis using MRI and CT in adolescents treated conservatively.

BACKGROUND: This study evaluated the union rate of acute lumbar spondylolysis in patients treated conservatively, according to the protocol. METHODS: The subjects included high school students and younger patients who were diagnosed with lumbar spondylolysis presenting bone marrow edema. We investigated the union rate, the period until union, unilateral or bilateral, vertebral level, laterality (right or left), and pathological stage at the first visit. Some unilateral cases included bilateral spondylolysis with contralateral pseudarthrotic lesion; therefore, the union rate of the "true" unilateral case in which the contralateral side was normal was calculated. We excluded multi-level lesions. RESULTS: With conservative treatment for lumbar spondylolysis of 189 lesions in 142 cases, 144 healed and 45 were considered as nonunion. The average treatment period until union was 106 days. The union of "true" unilateral cases in which the contralateral side was normal was noted in 68/71 lesions, but that of bilateral cases was noted in 71/94 lesions. The union in L3, L4, and L5 vertebrae was noted in 15/17, 40/49, and 89/123 lesions, respectively. The union was observed in 63/87 on the right and 86/102 on the left. The union was noted in the pre-lysis, early, and progressive stages in 36/39, 81/97, and 27/53 lesions, respectively. Furthermore, the union was noted in stages 0, 1a, 1b, 1c, and 2 in 13/15, 47/52, 30/36, 34/42, and 20/44 lesions, respectively. CONCLUSION: Accurate union evaluation using CT and MRI showed a union rate of 76% with conservative treatment for spondylolysis. The union rate of the "true" unilateral cases in which the contralateral side was normal was 96%, which was significantly higher than that of the bilateral cases. Moreover, the union rate of lesions in the axial progressive stage and sagittal stage 2 was significantly lower than that of lesions in other stages. STUDY DESIGN: clinical retrospective study.

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

Lumbar spondylolysis is a fatigue fracture that occurs most frequently in middle and high school athletes. Conservative treatment is the first choice when the fracture is fresh. Surgical treatment of lumbar spondylolysis is often reported for pseudarthrosis cases, but surgery for cases of fresh fractures is rare. We report a case of a 16-year-old male, high jump athlete, with recurrent non-pseudoarthorotic lumbar spondylolysis. He presented to our hospital with a chief complaint of back pain, and was diagnosed as right L5, pre-lysis-stage lumbar spondylolysis. After 3 months of conservative treatment, bone union was achieved with no obvious worsening of the fracture. His back pain also disappeared and he was able to return to exercise. At 6 months after the first examination, the lesion recurred and he could no longer continue playing sports, so surgical treatment was indicated. Minimally invasive screw fixation was performed by combining Buck's method and the cortical bone trajectory. After the surgery, he started jogging at 5 weeks, resumed jumping practice at 7 weeks, and returned to competition at 2 months. He set a new personal best in a competition 3 months post-surgery. Bone union was achieved at 4 months. This technique is minimally invasive and does not involve debridement or bone grafting, which provides early pain relief and return to sports.

'Within Ring' Concept Treatment for Displaced H-Shaped Type IVb Fragility Fractures of the Pelvis.

INTRODUCTION: Sacroiliac rod fixation (SIRF) preserves the mobility of L5/S1 (lumber in the pelvis), as a surgical procedure for high-energy pelvic ring fractures. The concept of SIRF method without pedicle screws into L4 and L5 is called 'within ring' concept. Case Presentation. We report here the clinical results of 'within ring' concept treatment with sacroiliac rod fixation for a case of displaced H-shaped Rommens and Hofmann classification type IVb fragility fractures of the pelvis (FFP), which A 79-year-old woman had been difficult to walk due to pain that had been prolonged for more than one month since her injury. The patient was successfully treated with SIRF, no pain waking with a walking stick and returned to most social activities including living independently within 6 months of the operation. CONCLUSION: SIRF is useful because it can preserve the mobility in the lumbar pelvis; not including the lumbar spine in the fixation range like spino pelvic fixation is a simple, safe, and low-invasive internal fixation method for displaced H-shaped type IVb fragility fractures of the pelvis.

Conservative treatment for lumbar spondylolysis in children of elementary school age.

PURPOSE: Lumbar spondylolysis in children of elementary school age has different characteristics from those of junior or senior high school patients. The purpose of the present study was to investigate the outcomes of conservative treatment for lumbar spondylolysis in patients of elementary school age. METHODS: We included 46 lesions in 32 consecutive patients of elementary school age with fresh cases of lumbar spondylolysis (5 girls and 27 boys; mean age, 11.3 years). We examined the relationship between bone union after conservative treatment and factors such as the CT axial staging, whether the lesion was unilateral or bilateral, whether the contralateral lesion was terminal stage, and the presence of spina bifida occulta. RESULTS: Bone union was achieved in 33 lesions (72%) in 23 patients, whereas 13 lesions (28%) in 9 patients could not obtain bone union. The proportion of unilateral lesions with bone union was 13 of 13 (100%), significantly higher than that for bilateral lesions (20/33 lesions, 61%, p = 0.009). Of the 33 bilateral lesions, bone union was attained in 20 of 28 (71%) lesions without contralateral terminal stage, whereas bone union was not attained in any of 5 (0%) lesions with contralateral terminal stage, showing a significant difference between those with or without contralateral terminal stage (p = 0.005). CONCLUSION: Bilateral lesions and contralateral terminal stage are possible unfavorable factors to bone union in conservative treatment for patients of elementary school age with lumbar spondylolysis. Early diagnosis and treatment before the lesions become bilateral or progressive stage are important.