We report a prospective case-series study to evaluate the results of non-operative and operative treatment of symptomatic unilateral lumbar spondylolysis. Non-operative treatment results in healing in most patients with symptomatic unilateral spondylolysis. Surgery however is indicated when symptoms persist beyond a reasonable time affecting the quality of life in young patients particularly the athletic population. We treated 41 patients [31 male, 10 female] with suspected unilateral lumbar spondylolysis. Thirty-one patients were actively involved in sports at various levels. Patients with a positive stress reaction on SPECT imaging underwent a strict protocol of activity restriction, bracing and physical therapy for 6 months. At the end of six months, patients who remained symptomatic underwent a Computed Tomography [CT] scan to confirm the persistence of a spondylolysis. Seven patients subsequently underwent a direct repair of the defect using the modified Buck's Technique. Baseline Oswestry disability index [ODI] and Short-Form-36 [SF-36] scores were compared to two year ODI and SF-36 scores for all patients. In the non-operated group, the mean pre-treatment ODI was 36 [SD=10.5], improving to 6.2 [SD=8.2] at two years. In SF-36 scores, the physical component of health [PCS] improved from 30.7 [SD=3.2] to 53.5 [SD =6.5] [p<0.001], and the mean score for the mental component of health [MCS] improved from 39 [SD=4.1] to56.5 [SD=3.9] [p<0.001] at two years. 20/31 patients resumed their sporting career within 6 months of onset of treatment, a further 4/31 patients returned to sports within one year. The seven patients who remained symptomatic at six months underwent a unilateral modified Buck's Repair. The most common level of repair was L5 (n=4). The mean pre-operative ODI was 39.4 (SD=3.6) improving to 4.4 (SD=4) at the latest follow-up. The mean score of PCS [SF-36] improved from 29.6 [SD=4.4] to 51.2 [SD=5.2] (SD=5.2) (p<0.001) and the mean score of MCS (SF-36) improved from 38.7 (SD=1.9) to 55.5 (SD=5.4) (p<0.001). A specific protocol of conservative treatment for patients with a unilateral lumbar spondylolysis resulted in a high rate of success with 83% of patients avoiding surgery. If symptoms persist beyond a reasonable period (i.e. 6 months) and reverse gantry CT scan confirms a non-healing defect of the pars interarticularis one may consider a unilateral direct repair of the defect with good outcome ultimately

There is conflicting information regarding the recommendations of bracing, physical therapy and cessation of sports for young athletes with symptomatic spondylolysis. The purpose of this study was to identify factors affecting the prognosis and to find the optimal method of non-operative treatment. The patients in our study were athletes who visited our children's hospital for low back pain with lumbar spondylolysis and were treated non-operatively from 1990 to 2002. Clinical and radiological outcomes were reviewed retrospectively. The effects of bracing, physical therapy, cessation of sports, duration of symptoms before the first hospital visit, lateralisation of spondylolysis, age, gender, onset of low back pain after lumbar trauma during sports, bone scan uptake, vertebral level of the lesion, associated scoliosis or spina bifida and radiological bony healing were analysed using univariate and multivariate analysis with logistic regression. The mean age of patients was 13 years (range 7 to 18 years). The mean follow-up was 4.2 years (range 1.2 to 12 years). Of 132 patients, 48 patients had excellent results with no pain during sports, 76 good, 6 fair, and 4 poor. Cessation of sports, early non-operative intervention, and a unilateral spondylolysis appeared to be factors associated with excellent outcomes. However, bracing, physical therapy, age, gender, level of lesion, history of trauma, increased uptake on bone scan, or associated scoliosis or spina bifida were not factors. Bony healing was not related to the clinical outcome. The non-operative treatment of spondylolysis in children can yield excellent clinical outcomes, and the absence of bony healing has no influence on clinical outcome. Factors in this study found to correlate with an excellent outcome include unilateral spondylolysis, acute spondylolysis, and treatment with cessation of sports for 12 weeks

Introduction. Lumbar spondylolysis is a fatigue fracture of the pars interarticularis and correlates with Spina Bifida Oculta (SBO) in 67%. Hpothesis. Load is normally transferred across the arch in axial rotation. Bifid arch results in increased strain across the isthmus of the loaded inferior articular process. Aim of investigation. Finite element (FE) analysis of altered load transfer in combined axial rotation and anteroposterior shear in SBO potentially predisposing to fatigue fracture of the pars interarticularis. Methods. FE models of natural and SBO (L5-S1) including ligaments were axially load to 1kN and an axial rotation of 3° applied. Bilateral stresses and strains on intact and SBO lateral inferior lines of the L5 isthmus were assessed and compared. Results. Under 1000N axial load: Maximum von Mises stress observed on left and right lateral inferior lines of L5 isthmus were 0.13 and 0.24 MPa, with maximum equivalent strain values of 1.56 and 2.91 (strain, for natural spine and SBO, respectively. Combined with 3° axial rotation (rotation of spinal processes toward right lateral side): Left lateral L5 isthmus stresses increased to 0.49 and 0.77 MPa for natural spine and SBO, respectively. Right lateral L5 isthmus values increased to 0.67 and 0.95 MPa for natural spine and SBO, respectively. The percentage increase in SBO strains compared to the natural spine on the L5 isthmus were +57.9 and +40.2%. Conclusion. Significant load transfer occurs through the vertebral arch in axial rotation. In SBO this load transfer is lost and mechanical demand on the isthmus is significantly increased. Strain increases across the L5 isthmus in axial rotation by +40.2% to +57.9% compared to normal and may predispose to fatigue fracture

Introduction: Spondylolysis in skeletally immature individuals is common but only a small proportion of cases develop pain and spondylolisthesis. The pattern of instability and pathologic consequences of surgically created spondylolytic defects have not previously been described. An animal model of lumbar spondylolysis was created using skeletally immature sheep with the aim of observing the intervertebral mobility and pathologic consequences of creating a spondylolytic segment. Methods: Bilateral spondylolytic defects were created in the fifth lumbar vertebrae of fourteen sheep aged approximately 16 weeks using a posterior surgical approach. Using tantalum markers that were placed in the lumbar spine segments in the vicinity of the lesion, three dimensional translations and rotations in flexion and extension were recorded under general anaesthetic using Radiostereometric Analysis (RSA) at the time of surgery. A novel method of ovine spine manipulation was developed. Briefly, with the animal in a lateral decubitus position spinal extension was achieved by fixing the shoulders and hips in full extension. Similarly, the limbs were brought into apposition to achieve spinal flexion. A control group of seven sheep had tantalum markers only in the same lumbar spine segments. The animals were re-tested under general anaesthetic at six weeks and six months following surgery. After six months the animals were sacrificed and their spines examined using CT and microscopic analysis. Results: Bilateral spondylolytic defects did not result in significant transverse (x-axis) translation. RSA showed significant differences between the spondylolytic group (mean 1.22°, range 0.30–3.74) and controls (mean 0.28°, range 0.03–0.77)) for rotation in the axial plane (y-axis, p< 0.0025) immediately after surgery. The spines radiologically stabilised over six months. Discussion: Surgically induced bilateral spondylolytic defects in this immature ovine model result in increased rotation in the axial plane but do not create transverse translation (spondylolisthesis)

The incidence of symptomatic pars defect varies between 15% and 47% in the young athletic population. We have analysed the outcome of direct repair spondylolysis on young professional athletes. We have prospectively studied 22 young athletes with lumbar spondylolysis in whom conservative treatment has failed. Fifteen male and 7 female patients with a mean age of 20.2 years (range 15–34 years) were surgically treated for radiographically confirmed spondylolysis between 1994 and 1999. Eleven patients were professional footballers and four were professional cricketers. Pre-operative assessment included plain X rays, SPECT imaging with planar bone scan and reverse gantry CT scans. All patients had the Oswestry disability index (ODI) and 19 patients had Short Form 36 (SF-36) scores recorded pre-operatively and two years post operatively. Nineteen patients underwent Buck’s fusion and 3 underwent Scott’s fusion. At two-year follow-up nineteen patients had ODI and SF36 scores recorded. Return to the sporting activity at the previous level was regarded as a successful outcome. The average duration of back pain prior to surgery was 8.9 months (range 1-36 months). The mean lysis defect determined by CT was 3.5 mm (range 1–8 mm). The mean pre-operative ODI was 39.5 (SD=8.7) and the mean post-operative ODI was 10.7 (SD=12.9). The mean scores of the physical health component of SF-36 improved from 27.1 (SD=5.1) to 47.8 (SD=7.7). The mean scores of the mental health component of SF-36 improved from 39.0 (SD=3.9) to 55.4 (SD=6.3) [P < 0.001]. The surgical repair of bilateral spondylolysis with modified Buck’s fusion in professional sportsmen and women results in a significant improvement in Oswestry Disability scores (p< 0.001) and in all domains of SF36 health questionnaire (p< 0.001). Ninety five percent of patients in this group return to active sport within seven months of surgery

To determine how long after injury a single photon emission computed tomography (SPECT) scan may remain positive in cases of symptomatic posterior element lumbar stress injuries. SPECT scans can identify posterior element lumbar stress injuries earlier than other imaging modalities. As these lesions evolve and the spondylolysis becomes chronic, the SPECT scan tends to revert to normal even though healing of the defect has not occurred. The aim of this study was to determine how long after initial injury a SPECT scan might remain positive. One hundred and sixty-five patients (85 male, 80 female) between the ages of 8 and 38 years with suspicion of lumbar spondylolysis or posterior element lumbar stress injuries were investigated. All patients underwent plain radiographs, planar bone scintigraphy and SPECT imaging. The duration of symptoms at clinical assessment was recorded. The age, sex, symptom reproduction on flexion or extension, level of sporting activity, and the Oswestry Disability Index both pre- and post-treatment were also recorded. SPECT positive images (hot scans) were depicted as cases and SPECT negative images as controls. Univariate and multivariate analysis was performed. Eighty-five patients (63 male, 22 female) had positive SPECT scans (cases); eighty had negative scans (controls). The mean age at onset of symptoms was 20.2 years for cases and 17.4 years for controls. Bilateral increased uptake on SPECT scan was more common than unilateral. The commonest site for increased uptake was the posterior elements of the fifth lumbar vertebra. Low back pain in extension was more common in SPECT positive cases. The mean time from injury / onset of symptoms to a positive SPECT scan was 7.1 months (range 5.2–9.2 months) and to a negative SPECT scan was 22.5 months (range 16.8–28.4 months). Intense scintigraphic activity in the posterior elements of the lumbar spine was associated with a more recent injury and was concordant with the patient’s history and physical examination. Chronic, un-united spondylolysis was often scintigraphically occult. There was a window of approximately six months from the onset of symptoms to investigation after which the sensitivity of SPECT imaging diminished

Objective: To assess the clinical outcome and return to sport following surgical treatment of spondylolysis in young sporting individuals. Design: A prospective outcome analysis of consecutive surgically treated cases of lumbar spondylolysis in young sporting individuals. Subjects: Twenty-two young sports persons (15M: 7F) with a mean age of 20.2 years (range 15–34 years) were surgically treated for radiographically confirmed spondylolysis between 1994 and 1999. Eleven patients were professional footballers and four were professional cricketers. Pre operative assessment included plain X-rays, SPECT imaging with planar bone scan and reverse gantry CT scans. All subjects had pre-operative Oswestry Disability Index (ODI) and SF36 scores recorded. Eighteen patients underwent Buck’s fusion and four patients underwent Scott’s fusion. A graduated exercise regime was commenced at 12 weeks. At two year follow-up nineteen patients had ODI and SF36 scores recorded. Outcome Measures: The clinical outcome in individual patients supported by statistical analysis of the pre operative and post-operative data was performed using SPSS (ver 10). Return to the sporting activity at the previous level was regarded as a successful outcome. Results: Eleven patients had bilateral spondylolysis at L5. Twenty patients had positive uptake on SPECT imaging and the remaining two were diagnosed to have lysis on CT scans alone. The average duration of back pain before the patients underwent surgery were 8.4 months (range 3–36 months). The mean lysis defect determined by CT was 3.5 mm (range 1–8 mm). The mean pre-operative and post-operative ODIs were 40.5 and 12.4 respectively (SEpreop = 2.06 and SEpostop = 3.05). The mean scores of physical health component of SF36 improved from 27.1 to 47.8 (SEmean = 1.1 and 1.7 respectively). The mean scores of mental health component of SF36 improved from 39.1 to 55.3 (SEmean = 0.9 and 1.4 respectively) [P < 0.001]. Eighteen patients returned to their previous active sporting career following an average of seven months of rehabilitation (range 4–10 months). Conclusions: The surgical repair of bilateral spondylolysis with Buck’s fusion in professional sportsmen and women results in a significant improvement in Oswestry Disability scores (P< . 001) and in all domains of SF36 health questionnaire (P< . 001). 90% return to active sport seven months following surgery