L5 spondylolysis: Anatomical study comparing healed and unhealed lesions.

The anatomy and pathogenesis of spondylolysis has been widely studied; however, the microanatomy of spondylolysis of the lumbar vertebra has not been well described. Therefore, we aim to better elucidate this anatomy. Twenty dry bone specimens of healed and unhealed spondylolysis of the L5 vertebra were collected from human skeletal remains. Twelve L5 vertebrae were examples of unhealed spondylolysis and eight specimens exhibited a healed (i.e., bony fusion of the lesion) spondylolysis lesion. The specimens underwent macro and microanatomical analysis followed by CT and microCT imaging. Finally, selected healed and unhealed lesions were submitted for histological analysis using Mason Trichrome staining. The pars interarticularis of two L5 vertebrae without signs of healed/unhealed spondylolysis were evaluated histologically as controls. Of the 12 unhealed L5 pars defects, three were unilateral on left side. Of the eight healed pars defects, all were unilateral and seven of these were on left sides. One unilateral pars defect also had spina bifida occulta. Both on imaging and histological analysis, healed pars defects were only so superficially and not at deeper levels. Histologically, unhealed edges were made up of dense cortical bone while healed edges were made up primarily of trabecular bone. Based on our anatomical findings, the so-called healed spondylolysis lesions, although externally fused, are not thoroughly fused internally. Moreover, the anterior and posterior edges of the unhealed spondylosysis lesions are irregular and show signs of long-term disarticulation. Taken together, these data suggest that such 'healed' lesions might not be as stable as the normal L5 pars interarticularis.

Bilateral spondylolysis of inferior articular processes of lumbar vertebra with no active sports history: Case report and review of literature.

Lumbar spondylosis, though mostly occurs at pars interarticularis of vertebrae, it rarely occurs at articular processes. Like the ones in pars interarticularis, articular process fractures are stress fractures that are usually seen in people participated in active sprts activity. Most of the time, nonoperative treatment is adequate. When conservative treatment fails, removal of fragments accomplishes pain relief. In this report, we present a case with bilateral spondylolysis of inferior articular processes at 3rd lumbar vertebrae and discuss with regards to the literature.

Phenotypic characterization of Slc26a2 mutant mice reveals a multifactorial etiology of spondylolysis.

Confusion persists over pathogenesis of spondylolysis. To confirm pathogenicity of the previously identified causative mutation of spondylolysis and investigate the genetic etiology, we generate a new mouse line harboring D673V mutation in the Slc26a2 gene. D673V mutation induces delayed endochondral ossification characterized by transiently reduced chondrocyte proliferation in mice at the early postnatal stage. Adult D673V homozygotes exhibit dysplastic isthmus and reduced bone volume of the dorsal vertebra resembling the detached vertebral bony structure when spondylolysis occurs, including the postzygopophysis, vertebral arch, and spinous process, which causes biomechanical alterations around the isthmic region of L4-5 vertebrae indicated by finite element analysis. Consistently, partial ablation of Slc26a2 in vertebral skeletal cells using Col1a1-Cre; Slc26a2 fl/fl mouse line recapitulates a similar but worsened vertebral phenotype featured by lamellar isthmus. In addition, when reaching late adulthood, D673V homozygotes develop an evident bone-loss phenotype and show impaired osteogenesis. These findings support a multifactorial etiology, involving congenitally predisposed isthmic conditions, altered biomechanics, and age-dependent bone loss, which leads to SLC26A2-related spondylolysis.

Prevalence of Spondylolysis in Symptomatic Adolescent Athletes: An Assessment of Sport Risk in Nonelite Athletes.

OBJECTIVE: To assess the risk of spondylolysis by sport in nonelite adolescent athletes with low back pain (LBP). DESIGN: Retrospective case series. SETTING: Hospital-based sports medicine clinic. PATIENTS: The medical charts of 1025 adolescent athletes with LBP (age 15 ± 1.8 years) were examined; 308 (30%) were diagnosed with a spondylolysis. ASSESSMENT OF RISK: Risk of spondylolysis was assessed in 11 sports for males and 14 sports for females. MAIN OUTCOME MEASURE: Relative risk of diagnosis of spondylolysis injury. RESULTS: The risk of spondylolysis differed by sex with baseball (54%), soccer (48%), and hockey (44%) having the highest prevalence in males and gymnastics (34%), marching band (31%), and softball (30%) for female athletes. Baseball was the only sport to demonstrate a significant increased risk of spondylolysis. CONCLUSIONS: The sports with the greatest risk of spondylolysis in adolescent athletes in this study were not consistent with published literature. Clinicians should be cautious generalizing high-risk sports to their practice, as geographic region and level of the athlete may significantly influence the incidence of spondylolysis in the population they are treating.

Biomechanical analysis of spino-pelvic postural configurations in spondylolysis subjected to various sport-related dynamic loading conditions.

PURPOSE: To study the risks of spondylolysis due to extrinsic loading conditions related to sports activities and intrinsic spino-pelvic postural parameters [pelvic incidence (PI) and sacral slope (SS)]. METHODS: A comprehensive osseo-disco-ligamentous L4-S1 finite element model was built for three cases with spondylolysis representing three different spino-pelvic angular configurations (SS = 32°, 47°, 59° and PI = 49°, 58°, 72°, respectively). After simulating the standing posture, 16 dynamic loading conditions were computationally tested for each configuration by combining four sport-related loads (compression, sagittal and lateral bending and axial torque). For each simulation, the Von Mises stress, L5-S1 facet contact force and resultant internal loads at the sacral endplate were computed. Significant effects were determined with an ANOVA. RESULTS: The maximal stress and volume of cancellous bone in the pars with stress higher than 75% of the ultimate stress were higher with 900 N simulated compression (2.2 MPa and 145 mm3) compared to only the body weight (1.36 MPa and 20.9 mm3) (p < 0.001). Combined compression with 10 Nm of flexion and an axial torque of 6 Nm generated the highest stress conditions (up to 2.7 MPa), and L5-S1 facet contact force (up to 430 N). The maximal stress was on average 17% higher for the case with the highest SS compared to the one with lowest SS for the 16 tested conditions (p = 0.0028). CONCLUSIONS: Combined flexion and axial rotation with compression generated the highest stress conditions related to risks of spondylolysis. The stress conditions intensify in patients with higher PI and SS. These slides can be retrieved under Electronic Supplementary Material.

Acquired spondylolysis and spinopelvic sagittal alignment.

Acquired spondylolysis represents an uncommon complication of spine surgery, of an unknown incidence and etiology. We studied patients presenting this rare entity, with the purpose to investigate the incidence, imaging findings, patients' clinical characteristics, as well as to provide an interpretation of the mechanisms that may lead to this phenomenon. The presented working hypothesis, regarding etiology, suggests that there is a relation between variations in spinopelvic sagittal alignment and acquired spondylolysis. Between January 2010 and January 2015, six patients presented spondylolysis after short-segment transforaminal lumbar interbody fusion, at a mean time of 43 months after surgery. The preoperative intactness and postoperative defect of pars interarticularis were documented with computed tomography scans in all patients. Standard radiographical spinopelvic parameters were measured before and after surgery. The optimum values of lumbar lordosis (LL) and pelvic incidence minus lumbar lordosis modifier (PI-LL mismatch) were calculated as well. The incidence of acquired spondylolysis was 0.95% among patients with short-segment lumbar fusion. Patients presented high-grade PI with a vertically orientated sacral endplate, while LL was found 9° greater and PI-LL mismatch 9° lower than the respective optimum values, indicating a non-harmonized alignment. In conclusion, acquired spondylolysis, though rare, may occur in patients with high-grade PI and sacral slope, and suboptimal spinopelvic sagittal alignment after lumbar spine surgery, thereby highlighting the importance of detailed preoperative planning in spine surgery, along with the study of sagittal balance.

Characteristics of lumbar spondylolysis in elementary school age children.

PURPOSE: Lumbar spondylolysis, a stress fracture of the pars interarticularis in the lumbar spine, is often precipitated by trauma, but there may be a congenital predisposition to this condition. There have been few studies on spondylolysis in young children, despite their suitability for studies on congenital defects. The aim of this study was to identify the clinical features of lumbar spondylolysis in elementary school age children in order to elucidate its pathogenesis. METHODS: Thirty lumbar spondylolysis patients (23 boys, 7 girls, including a pair of twins; mean age 9.5 years, age range 5-12 years) were studied. Patient data on history of athletic activity, symptoms at first consultation, and radiological findings such as spinal level, stage of the stress fracture, and skeletal age were collected. RESULTS: Among the 30 patients, 27 (21 boys, 6 girls) had L5 spondylolysis (90.0 %). Only 2 patients had no history of athletic activity at the first consultation. All patients, except for 2 whose diagnosis was incidental, complained of low back pain. In the 27 patients with L5 spondylolysis, 17 (63.0 %) had terminal-stage fracture and 25 (92.6 %) had spina bifida occulta (SBO) involving the S1 lamina. Sixteen of the 27 (59.3 %) had SBO involving the affected lamina (L5) and S1 lamina. In contrast, the 3 patients with L3 or L4 spondylolysis had no evidence of SBO. With respect to skeletal age, 23 of the 27 L5 spondylolysis patients (85.2 %) were in the cartilaginous stage while the remaining 4 patients were in the apophyseal stage. CONCLUSION: Lumbar spondylolysis in elementary school age children was commonly a terminal-stage bone defect at L5, which was not necessarily related to history of athletic activity and was sometimes asymptomatic. It was often associated with SBO, indicating a possible congenital predisposition. These findings may provide further insight into the pathogenesis of lumbar spondylolysis.

Management of spondylolysis and low-grade spondylolisthesis in fine athletes. A comprehensive review.

OBJECTIVE: To provide evidence-based data about the aetiology, incidence, diagnosis and treatment of isthmic lumbar spondylolysis and low-grade spondylolisthesis and return to athletic activities in fine athlete. DESIGN: This is a comprehensive literature review. A thorough MEDLINE search in the period from 1973 to 2014 with the keywords: athlete, spondylolysis, low-grade spondylolisthesis, treatment and return to athletic activities was conducted. RESULTS: A total of 228 articles were initially enrolled from the search, and 74 case series and reviews were finally included because they referred to incidence, diagnosis, treatment and return to play in fine athletes with symptomatic isthmic spondylolysis and low-grade (Meyerding I and II) spondylolisthesis. There were 13 studies reporting surgical treatment (194 patients of average age 19 years) and 14 studies with conservative treatment (589 patients of average age 15.7). The percentage of athletes who were successfully treated with conservative or operative treatment was 85 and 87.8%, respectively. CONCLUSION: Conservative treatment including physiotherapy and bracing is the mainstay in the treatment of symptomatic spondylolysis and low-grade isthmic spondylolisthesis in fine athletes. If consequent treatment fails, the operative treatment (pars repair and short fusion) is decided. Return to play following surgery varies from 6 to 12 months with prohibition in collision sports. Return to play is mostly depended on specific sport activity.

Acute lumbar spondylolysis in intercollegiate athletes.

STUDY DESIGN: A retrospective case series. OBJECTIVE: The purpose of this study was to describe a unique group of intercollegiate athletes who are skeletally mature and who developed symptomatic acute lumbar spondylolysis and to study long-term return to play outcome of nonoperative and surgical repair of L3 and L4 spondylolysis in skeletally mature athletes. BACKGROUND: Traditionally, symptomatic acute lumbar spondylolysis is a defect found in skeletally immature athletes, most commonly in the pars interarticularis of L5, less commonly in the L3/L4 region, and even less commonly in skeletally mature athletes as described in this group. METHODS: Eight intercollegiate athletes (2 women and 6 men, ages ranging from 19 to 21 y) with acute lumbar spondylolysis were diagnosed by means of computed tomography (CT) and single photon emission-CT bone scan. L3 lesions were present in 5 patients, and L4 lesions were present in 3 patients. All patients were treated initially nonoperatively with a protocol of bracing and activity modification. The healing progress was assessed through repeat CT scan. Patients who failed to respond to nonoperative procedures underwent direct repair of their pars defect through variable angle pedicle screw and sublaminar hook. Outcomes were measured by completion of the Oswestry Low Back Pain Disability Questionnaire (mean follow-up 6.5 y) and return to athletic participation. RESULTS: All patients successfully returned to full athletic competition. Two patients showed radiographic healing and resolution of pain following 3 months of nonoperative treatment. Five patients required surgical repair of the pars defect. All of these patients eventually returned to unrestricted participation in athletics. CONCLUSIONS: This study shows that this subgroup will generally respond well to surgical correction of the pars defect and return to uninhibited competition following conservative treatment and/or surgical repair.

Should 25-hydroxyvitamin D and bone density using DXA be tested in adolescents with lumbar stress fractures of the pars interarticularis?

STUDY DESIGN: Retrospective study. OBJECTIVE: To determine if 25-hydroxyvitamin D (25[OH]D) level measurement and bone mineral density (BMD) using dual-energy x-ray absorptiometry (DXA) are indicated in children with a history of stress fracture of the pars interarticularis. SUMMARY OF BACKGROUND DATA: Healing rates of 4%-25% for bilateral and unilateral pars fractures, respectively, have previously been reported. Factors that may contribute to osteomalacia, rickets, and poor bone healing include low (25[OH]D) and low BMD. METHODS: Patients were seen at the Nebraska Spine Center between 2008 and 2010. Selection criteria included a diagnosis of pars fracture with DXA Z-score values (lumbar and hip) and pretreatment serum (25[OH]D) level measurement. Twenty-four patients were included. Vitamin D was defined as sufficient when ≥ 32 ng/mL, insufficient when 20 to < 32 ng/mL, and deficient when < 20 ng/mL. BMD was interpreted from DXA Z-scores using reference intervals defined in the literature. A Z-score <-2.0 was considered low for chronological age. RESULTS: The mean (± SD) vitamin D level was 29.9 ng/mL ± 10.8 (range, 9-56 ng/mL). Values were ≤ 10 ng/mL in 1 patient (4%), 11-20 ng/mL in 4 patients (17%), 21-30 ng/mL in 8 patients (33%), 31-50 ng/mL in 10 patients (42%), and > 50 ng/mL in 1 patient (4%). This correlated to 3 (13%) patients with deficient vitamin D (≤ 15 ng/mL), 12 (50%) patients with insufficient levels, and 9 (38%) with sufficient levels of vitamin D. The mean Z-scores were 0.43 ± 0.93 (lumbar, range, -1.3 to 2.8) and 1.0 ± 1.11 (hip, range, -0.5 to 3.0). All scores were consistent with normal bony mineralization for age. CONCLUSIONS: On the basis of these data, we recommend routine vitamin D testing and do not recommend routine DXA in adolescents with lumbar stress fractures of the pars interarticularis.

Spondylolysis and Isthmic Spondylolisthesis: A Guide to Diagnosis and Management.

INTRODUCTION: Spondylolysis and isthmic spondylolisthesis are commonly implicated as organic causes of low back pain in this population. Many patients involved in sports that require repetitive hyperextension of the lumbar spine like diving, weightlifting, gymnastics and wrestling develop spondylolysis and isthmic spondylolisthesis. While patients are typically asymptomatic in mild forms, the hallmark of symptoms in more advanced disease include low back pain, radiculopathy, postural changes and rarely, neurologic deficits. METHODS: We conducted a narrative review of the literature on the clinical presentation, diagnosis, prognosis and management of spondylolysis and isthmic spondylolisthesis. RESULTS: A comprehensive physical exam and subsequent imaging including radiographs, CT and MRI play a role in the diagnosis of this disease process. While the majority of patients improve with conservative management, others require operative management due to persistent symptoms. CONCLUSION: Due to the risk of disease progression, referral to a spine surgeon is recommended for any patient suspected of having these conditions. This review provides information and guidelines for practitioners to promote an actionable awareness of spondylolysis and isthmic spondylolisthesis.

Risk factor analysis of disc and facet joint degeneration after intersegmental pedicle screw fixation for lumbar spondylolysis.

BACKGROUND: Patients who do not respond to conservative treatment of the isthmus are often treated with surgery. We used direct repair plus intersegment pedicle screw fixation for the treatment of lumbar spondylolysis. The aim of this observational study was to assess the effects of this technique and evaluate various risk factors potentially predicting the probability of disc and facet joint degeneration after instrumentation. METHODS: The study included 54 male L5 spondylolysis patients who underwent pars repair and intersegment fixation using pedicle screws. Bony union was evaluated using reconstruction images of computed tomography. Radiographic changes, including disc height, vertebral slip, facet joint and disc degeneration in the grade of adjacent and fixed segments, were determined from before to final follow-up. Logistic regression analysis was performed to identify factors associated with the incidence of disc and facet joint degeneration. RESULTS: Bony union was achieved in all cases. Logistic regression analysis revealed that instrumentation durations of greater than 15.5 months and 21.0 months were significant risk factors for the incidence of L4/5 and L5S1 facet degeneration, respectively. CONCLUSIONS: Intersegmental pedicle screw fixation provides good surgical outcomes and good isthmic bony union rates in patients with lumbar spondylolysis. The duration of fixation was confirmed as a risk factor for facet joint degeneration. Once bony union is achieved, instrument removal should be recommended.

Lumbar spondylolysis: a review.

Spondylolysis is an osseous defect of the pars interarticularis, thought to be a developmental or acquired stress fracture secondary to chronic low-grade trauma. It is encountered most frequently in adolescents, most commonly involving the lower lumbar spine, with particularly high prevalence among athletes involved in certain sports or activities. Spondylolysis can be asymptomatic or can be a cause of spine instability, back pain, and radiculopathy. The biomechanics and pathophysiology of spondylolysis are complex and debated. Imaging is utilized to detect spondylolysis, distinguish acute and active lesions from chronic inactive non-union, help establish prognosis, guide treatment, and to assess bony healing. Radiography with satisfactory technical quality can often demonstrate a pars defect. Multislice CT with multiplanar reformats is the most accurate modality for detecting the bony defect and may also be used for assessment of osseous healing; however, as with radiographs, it is not sensitive for detection of the early edematous stress response without a fracture line and exposes the patient to ionizing radiation. Magnetic resonance (MR) imaging should be used as the primary investigation for adolescents with back pain and suspected stress reactions of the lumbar pars interarticularis. Several imaging pitfalls render MR imaging less sensitive than CT for directly visualizing the pars defects (regional degenerative changes and sclerosis). Nevertheless, the presence of bone marrow edema on fluid-sensitive images is an important early finding that may suggest stress response without a visible fracture line. Moreover, MR is the imaging modality of choice for identifying associated nerve root compression. Single-photon emission computed tomography (SPECT) use is limited by a high rate of false-positive and false-negative results and by considerable ionizing radiation exposure. In this article, we provide a review of the current concepts regarding spondylolysis, its epidemiology, pathogenesis, and general treatment guidelines, as well as a detailed review and discussion of the imaging principles for the diagnosis and follow-up of this condition.

Direct surgical repair of spondylolysis in athletes: indications, techniques, and outcomes.

OBJECT: Athletes present with back pain as a common symptom. Various sports involve repetitive hyperextension of the spine along with axial loading and appear to predispose athletes to the spinal pathology spondylolysis. Many athletes with acute back pain require nonsurgical treatment methods; however, persistent recurrent back pain may indicate degenerative disc disease or spondylolysis. Young athletes have a greater incidence of spondylolysis. Surgical solutions are many, and yet there are relatively few data in the literature on both the techniques and outcomes of spondylolytic repair in athletes. In this study, the authors undertook a review of the surgical techniques and outcomes in the treatment of symptomatic spondylolysis in athletes. METHODS: A systematic review of the MEDLINE and PubMed databases was performed using the following key words to identify articles published between 1950 and 2011: "spondylolysis," "pars fracture," "repair," "athlete," and/or "sport." Papers on both athletes and nonathletes were included in the review. Articles were read for data on methodology (retrospective vs prospective), type of treatment, number of patients, mean patient age, and mean follow-up. RESULTS: Eighteen articles were included in the review. Eighty-four athletes and 279 nonathletes with a mean age of 20 and 21 years, respectively, composed the population under review. Most of the fractures occurred at L-5 in both patient groups, specifically 96% and 92%, respectively. The average follow-up period was 26 months for athletes and 86 months for nonathletes. According to the modified Henderson criteria, 84% (71 of 84) of the athletes returned to their sports activities. The time intervals until their return ranged from 5 to 12 months. CONCLUSIONS: For a young athlete with a symptomatic pars defect, any of the described techniques of repair would probably produce acceptable results. An appropriate preoperative workup is important. The ideal candidate is younger than 20 years with minimal or no listhesis and no degenerative changes of the disc. Limited participation in sports can be expected from 5 to 12 months postoperatively.

The incidence of spondylolysis and spondylolisthesis in children with osteogenesis imperfecta.

BACKGROUND: Spondylolysis and spondylolisthesis are common abnormalities of the lumbar spine. The incidence of these diagnoses is recognized in the healthy population. However, their incidence in osteogenesis imperfecta (OI) patients is less well defined. METHODS: This is a retrospective radiographic review of patients treated in the OI clinic from a single institution. Lateral radiographs were reviewed on all available patients to assess the incidence of spondylolysis and spondylolisthesis in this patient population. The morphology of the pedicle and pars interarticularis was also evaluated to identify any abnormalities or dysplasia of these structures. RESULTS: One hundred ten of the 139 patients treated in the OI clinic met the inclusion criteria for this study. Of these patients, 79% (87 of 110) were ambulatory. The overall incidence of spondylolysis in this pediatric OI population was found to be 8.2% (9 of 110) at an average age of 7.5 years. The incidence of spondylolisthesis was 10.9% (12 of 110) at an average age of 6.5 years with 75% (3 of 12) being isthmic type and 25% (3 of 12) dysplastic. The combined incidence of spondylolysis and spondylolisthesis was 19.2%. Incidentally, the pedicle length was noted to be elongated in 40.0% (44 of 110) of this OI population. CONCLUSIONS: This study found that the incidence of spondylolysis in a group of children with OI was much higher than in the normal pediatric population, which has been reported to be 2.6% to 4.0%. This incidence was also found to be higher than previously reported incidence of spondylolysis in OI patients (5.3%). The incidence of spondylolisthesis was also found to be much higher than that of the normal pediatric population (4.2%). It is important to recognize this higher incidence of these abnormalities and to anticipate future associated symptoms and potential worsening listhesis that can clinically affect the lifestyles of these children and potentially require surgical treatment. The clinical significance of these findings will necessitate long-term follow-up.

Spondylolysis Repair Using a Minimally Invasive Modified Buck Technique with Neuronavigation and Neuromonitoring in High School and Professional Athletes: Technical Notes, Case Series, and Literature Review.

BACKGROUND: Spondylolysis is a defect in the pars interarticularis of the vertebra that occurs frequently in high-performance young athletes. Although nonsurgical management is the mainstay of treatment, surgery is an option for patients with persistent symptoms despite multiple cycles of nonsurgical treatment. Performing a minimally invasive technique reduces complications, postsurgery pain, and hospitalization time and leads to a quick recovery. The aim of this study was to report the clinical results of a series of 3 patients treated with a modification of the Buck technique with a minimally invasive approach. METHODS: Three high-performance athletes between 17 and 18 years old who were managed nonsurgically for at least 6 months underwent a modified Buck technique repair with a minimally invasive approach using cannulated compression screws, with neuronavigation and neuromonitoring. Patients were followed at least 6 months with computed tomography scans to assess consolidation and fixation status. Following rehabilitation and in the absence of pain, all 3 athletes returned to their respective sports. No complications were reported. RESULTS: All patients presented with bilateral spondylolysis, at L3 in 1 case and at L5 in 2 cases. Patients received conservative management for 12-36 months before surgery. After surgery, consolidation was obtained at 4 months in all patients, who returned to their sports activities in <6 months. CONCLUSIONS: The proposed technique shows the advantages of performing minimally invasive surgery in young high-performance athletes, ensuring consolidation and early return to sports activity without complications.

Features of sacral alar fatigue fractures in adolescent athletes with overuse.

Three types of sacral alar fatigue fractures are elderly, postnatal, and sport-related. They are most prevalent in athletes during adulthood; there are few reports of sacral alar fatigue fractures in young athletes. The purpose of this study was to analyze sacral alar fatigue fractures in adolescent athletes. Of the 920 patients hospitalized with low back pain, 13 were diagnosed with sacral alar fatigue fractures with magnetic resonance imaging (MRI) abnormalities. We investigated age, sex, sports discipline, span from symptom onset to consultation, laterality, complication with spondylolysis, computed tomography (CT) findings, and treatment span. The average age was 14.5 years old (8-men and 5-women). The most frequent discipline was basketball. The span to consultation was 13.2 days. The number of right-side cases was 9. Seven cases were complicated by bilateral spondylolysis. MRI abnormalities were observed in all the cases. Only two patients showed abnormal findings on CT. Averagely 67 days after treatment, participants returned to their sports. Sacral alar fatigue fractures suggest that the span from onset to consultation is short. Fracture lines are often unclear on CT, and MRI is useful for diagnosis. More than half of the cases in this study were complicated by lumbar spondylolysis.

One-year clinical outcome after full-endoscopic interlaminar lumbar discectomy for isthmic lumbar spondylolisthesis: Two case reports.

RATIONALE: For isthmic lumbar spondylolisthesis (ILS) associated with the removal of herniation, it remains challenging to perform less invasive and minimally disruptive procedures. Good results could potentially be obtained by further preserving the posterior elements in full-endoscopic lumbar discectomy (FESS), which is less invasive than microenscopic surgery (MES). PATIENT CONCERNS: One patient complained of left leg pain, and another patient complained of right leg pain and low back pain. DIAGNOSES: Two patients with ILS and Meyerding Grade 1 lumbar spondylolisthesis. INTERVENTIONS: We performed a full-endoscopic lumbar discectomy via the interlaminar space (FESS-IL) for L5/S1 lumbar disc herniation (LDH) accompanied by isthmic lumbar spondylolisthesis. FESS-IL was performed in 2 patients with radiculopathy caused by different types of LDH using a full endoscopic system with a 4.1 mm working channel and 6.9 mm outer diameter. A 3.5-mm diameter high-speed drill was used in one patient for an upward-migrated LDH in the inner-rim of the infravertebral border. The other patient underwent minimal resection without bone resection. OUTCOMES: The one-year clinical outcome included confirmation of pain relief and evacuation of migrated LDH on magnetic resonance imaging in all patients. There was no progression of slippage on radiography. The mean operative time was 82 min, and no complication was observed. The one-year clinical outcome demonstrated sufficient pain relief. LESSONS THE Y: ear postoperative outcome showed improvement. We believe that FESS-IL is a viable alternative operative approach for LDH for ILS.

Upper extremity stress fractures and spondylolysis in an adolescent baseball pitcher with an associated endocrine abnormality: a case report.

Lower extremity stress fractures are relatively common among competitive athletes. Stress fractures of the upper extremity, however, are rare and most have been reported in the literature as case reports. We present a case of an adolescent baseball pitcher who had both proximal humeral and ulnar shaft stress fractures, as well as spondylolysis of the lumbar spine. This particular patient also had an underlying endocrine abnormality of secondary hyperparathyroidism with a deficiency in vitamin D. A bone mineral density panel demonstrated a high T score (+2.79 SD above the mean) and the patient's biologic bone age was noted to be 2 years ahead of his chronologic age. The patient was treated with a course of vitamin D and calcium supplementation. After treatment, both the vitamin D and parathyroid hormone returned to normal levels. The upper extremity stress fractures and spondylolysis were managed conservatively and he was able to return to full activity and baseball. For patients who present with multiple stress fractures not associated with consistent high levels of repeated stress, a bone mineral density panel should be considered. If vitamin D deficiency is present, a course of oral supplementation may be considered in the management. An endocrinology consult should also be considered in patients who present with multiple stress fractures. Conservative management of upper extremity stress fractures and spondylolysis was successful in returning this patient back to his previous activity level.

Comparison of symptomatic spondylolysis in young soccer and baseball players.

BACKGROUND: Spondylolysis is the main cause of low back pain (LBP) in young athletes. There are few studies analyzing the difference of spondylolysis among young athletes with different sports activities. The purpose of this study was to compare the clinical factors and distribution of the lesions of spondylolysis on magnetic resonance imaging (MRI) scans in young soccer and baseball players with symptomatic spondylolysis. METHODS: The medical records of 267 young athletes aged 7 to 18 years old who underwent MRI to evaluate the cause of LBP between 2017 and 2020 were retrospectively reviewed to identify patients with spondylolysis. Of the young athletes with symptomatic spondylolysis, clinical factors and MRI findings in soccer and baseball players were retrospectively evaluated. The clinical factors were age, sex, interval from onset of LBP to MRI, and side of the dominant leg in the sports field. MRI findings included number, lumbar level, and side of the lesions. RESULTS: A total of 33 soccer players (mean age, 15.4 ± 1.4 years) and 49 baseball players (mean age, 15.4 ± 1.6 years) with symptomatic spondylolysis were enrolled. All patients were male. No significant differences were noted in age and the interval from onset of LBP to MRI between the groups. Soccer players had greater numbers of multiple (p < 0.001) and bilateral (p < 0.001) lesions than baseball players. The dominant side of the hand for pitching or batting was correlated with the contralateral-side lesions in baseball players (p = 0.001). CONCLUSIONS: The distribution of the lesions of spondylolysis differed in young soccer and baseball players. Pitching or batting with the dominant-side hand would be associated with contralateral-side lesions in baseball players. Sports-specific movements and the side of the dominant leg should be considered when treating young athletes with symptomatic spondylolysis.