Aims. Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution. Methods. In all 16 patients were included (eight female: eight male; 50% male), of whom nine had Hurler, five Morquio and two Hunter syndrome. Six patients were treated non-operatively (mean age at presentation of 6.3 years; 0.4 to 12.9); mean kyphotic progression +1.5. o. /year; mean follow-up of 3.1 years (1 to 5.1) and ten patients operatively (mean age at presentation of 4.7 years; 0.9 to 14.4); mean kyphotic progression 10.8. o. /year; mean follow-up of 8.2 years; 4.8 to 11.8) by circumferential arthrodesis with posterior instrumentation in patients with flexible deformities (n = 6). Results. In the surgical group (mean age at surgery of 6.6 years; 2.4 to 16.8); mean post-operative follow-up of 6.3 years (3.5 to 10.3), mean pre-operative thoracolumbar kyphosis of 74.3. o. (42. o. to 110. o. ) was corrected to mean of 28.6. o. (0. o. to 65. o. ) post-operatively, relating to a mean deformity correction of 66.9% (31% to 100%). Surgical complications included a deep wound infection treated by early debridement, apical non-union treated by posterior re-grafting, and stable adjacent segment spondylolisthesis managed non-operatively. Thoracolumbar kyphosis > +38. o. at initial presentation was identified as predicting progressively severe deformity with 90% sensitivity and 83% specificity. Discussion. This study demonstrates that severe thoracolumbar kyphosis in patients with MPS can be effectively treated by circumferential arthrodesis. Severity of kyphosis at initial presentation may predict progression of thoracolumbar deformity. Patients with MPS may be particularly susceptible to post-operative complications due to the underlying connective tissue disorder and inherent immunological compromise. Take home message: Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses with thoracolumbar kyphosis managed non-operatively or operatively in our institution. Cite this article: Bone Joint J 2016;98-B:229–37

To assess screw malposition rates and complications associated with pedicle screw insertion using 3D navigation technology. A retrospective study was undertaken for all cases where O-arm® and StealthStation® systems were used over a 2-year period. The primary outcome measure was return to theatre rates for pedicle screw malposition. A total of 938 screws were inserted (934 thoracolumbar and 4 cervical), and 103 patients underwent spinal fixation using O-arm® and StealthStation® navigation. 64 were revision cases and 39 primary cases. Average number of levels was 4.6. There were a total of 10 complications: 3 infections, 1 DVT, 1 PE, 1 fast atrial fibrillation (AF), 1 screw malposition, 1 non-union, 1 undisplaced vertebral body fracture and 1 nerve root compression following osteotomy. The percentage return to theatre for screw malposition using 3D navigation was 1% of patients and 0.1% of pedicle screws. No patients developed permanent neurological compromise. These systems provide accuracy that is comparable to traditional 2D fluoroscopic techniques. We advocate their use in the safe insertion of pedicle screws in complex revision deformity cases where original anatomical landmarks are absent or obscured. We also believe that radiation exposure is considerably less with navigation especially in these complex and revision cases

To present the results of surgical correction in patients with double or triple thoracic/lumbar AIS (Lenke types 2,3,4) with the use of a novel convex/convex unilateral segmental screw correction technique in a single surgeon's prospective series. We reviewed the medical records and spinal radiographs of 92 consecutive patients (72 female-20 male). We measured scoliosis, thoracic kyphosis, lumbar lordosis, scoliosis flexibility and correction index, coronal and sagittal balance before and after surgery, as well as at minimum 2-year follow-up. SRS-22 data was available preoperatively, 6-month, 12-month and 2-year postoperatively for all patients. Surgical technique. All patients underwent posterior spinal fusion using pedicle screw constructs. Unilateral screws were placed across the convexity of each individual thoracic or lumbar curve to allow for segmental correction. ‘Corrective rod’ was the one attached to the convexity of each curve with the correction performed across the main thoracic scoliosis always before the lumbar. Maximum correction of main thoracic curves was always performed, whereas the lumbar scoliosis was corrected to the degree required to achieve a balanced effect across the thoracic and lumbar segments and adequate global coronal spinal balance. Concave screws were not placed across any deformity levels. Bilateral screws across 2 levels caudally and 1–2 levels cephalad provided proximal/distal stability of the construct. Mean age at surgery was 14.9 years with mean Risser grade 2.8. The distribution of scoliosis was: Lenke type 2–26 patients; type 3–43 patients; type 4–23 patients. Mean preoperative Cobb angle for upper thoracic curves was 45°. This was corrected by 62% to mean 17° (p<0.001). Mean preoperative Cobb angle for main thoracic curves was 70°. This was corrected by 69% to mean 22° (p<0.001). Mean preoperative Cobb angle for lumbar curves was 56°. This was corrected by 68% to mean 18° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 34° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 45° (p<0.001) and lumbar lordosis 46.5° (p=0.69). Mean preoperative coronal imbalance was 1.2 cm. This corrected to mean 0.02 cm at follow-up (p<0.001). Mean preoperative sagittal imbalance was −2 cm. This corrected to mean −0.1 cm at follow-up (p<0.001). Mean theatre time was 187 minutes, hospital stay 6.8 days and intraoperative blood loss 0.29 blood volumes (1100 ml). Intraoperative spinal cord monitoring was performed recording cortical and cervical SSEPs and transcranial upper/lower limb MEPs and there were no problems. None of the patients developed neurological complications, infection or detected non-union and none required revision surgery to address residual or recurrent deformity. Mean preoperative SRS-22 score was 3.6; this improved to 4.6 at follow-up (p<0.001). All individual parameters also demonstrated significant improvement (p<0.001) with mean satisfaction rate at 2-year follow-up 4.9. The convex-convex unilateral pedicle screw technique can reduce the risk of neurological injury during major deformity surgery as it does not require placement of screws across the deformed apical concave pedicles which are in close proximity to the spinal cord. Despite the use of a lesser number of pedicle fixation points compared to the bilateral segmental screw techniques, in our series it has achieved satisfactory scoliosis correction and restoration of global coronal and sagittal balance with improved thoracic kyphosis and preserved lumbar lordosis. These results have been associated with excellent patient satisfaction and functional outcomes as demonstrated through the SRS-22 scores

Purpose of the study. To investigate the efficacy of pedicle screw instrumentation in correcting spinal deformity in patients with quadriplegic cerebral palsy. Also to assess quality of life and functional improvement after deformity correction as perceived by the parents of our patients. Summary of Background Data. All pedicle screw constructs have been commonly used to correct adolescent idiopathic scoliosis. There is limited information on their effectiveness in treating patients with cerebral palsy and neuromuscular scoliosis. Methods. We reviewed the medical records and serial radiographs of 45 consecutive patients with quadriplegia who underwent spinal arthrodesis using pedicle screw/rod instrumentation and a standardised surgical technique (prospectively collected single surgeon's series). All patients were wheelchair bound with collapsing thoracolumbar scoliosis and pelvic obliquity. Twenty-eight patients had associated sagittal deformities. A telephone survey was performed by an independent investigator to assess parents' perception on surgical outcome. Results. Thirty-eight patients underwent posterior-only and 7 staged anteroposterior spinal arthrodesis. Mean age at surgery was 13.4 years (range 9-18.3) and mean postoperative follow-up 3.5 years (range 2.8-5). Pedicle screw instrumentation extended from T2/T3 to L5 with bilateral pelvic fixation using iliac bolts. Scoliosis was corrected from mean 82.5° to 21.4° (74.1%). Pelvic obliquity was corrected from mean 24° to 4° (83.3%). In posterior-only procedures, average blood loss was 0.8 blood volumes, ICU stay 3.5 days, and hospital stay 17.6 days. In anteroposterior procedures, average blood loss was 0.9 blood volumes, ICU stay 8.9 days, and hospital stay 27.4 days. Major complications included one deep infection and one re-operation to remove prominent implants but no deaths, no neurological deficit and no detected pseudarthrosis. Parents' survey demonstrated 100% satisfaction rate. Conclusion. Pedicle screw instrumentation can achieve excellent correction of spinopelvic deformity in quadriplegic cerebral palsy with low complication and re-operation rates and high parent satisfaction. Our study has demonstrated that spinal correction using segmental pedicle screw/rod constructs can be performed safely and with lesser major complications and reoperations compared to the traditionally used Unit rod or hybrid instrumentation. The greater degree of deformity correction and lesser rate of complications and reoperations due to non-union, prominent instrumentation or failed pelvic fixation using a pedicle screw compared to the Unit rod technique should be balanced against the increased implant cost

Purpose of the study. To investigate the efficacy of pedicle screw instrumentation in correcting thoracolumbar/lumbar idiopathic scoliosis in adolescent patients. Summary of Background Data. Thoracolumbar/lumbar scoliosis has been traditionally treated through an anterior approach and instrumented arthrodesis with the aim to include in the fusion the Cobb-to-Cobb levels and preserve distal mobile spinal segments. Posterior instrumentation has been extensively used for thoracic or thoracic and lumbar scoliosis. In the advent of all-pedicle screw constructs there is debate on whether thoracolumbar/lumbar scoliosis is best treated through an anterior or a posterior instrumented arthrodesis. Methods. We reviewed the medical notes and radiographs of 19 consecutive adolescent patients with Lenke 5C idiopathic scoliosis (17 female-2 male, prospectively collected single surgeon's series). We measured the scoliosis, thoracic kyphosis and lumbar lordosis angles, apical vertebral rotation (AVR) and translation (AVT), trunk shift (TS), as well as the lower instrumented vertebra angle (LIVA) both pre-and post-operatively and at minimum 2-year follow-up. SRS 22 data was available for all patients. Results. All patients underwent posterior spinal arthrodesis of the primary thoracolumbar/lumbar curve using all-pedicle screw constructs. Mean age at surgery was 15.1 years. We identified 3 separate groups: Group 1 (9 patients) had a fusion to include the preoperative Cobb-to-Cobb levels of the curve; in Group 2 (8 patients) the fusion extended 1-2 levels distal (all patients) +/− proximal (4 patients) to the end Cobb vertebrae; in Group 3 (2 patients) the fusion extended to one level proximal to the lower end Cobb vertebra. Eight patients had compensatory thoracic curves. Mean Cobb angle before surgery was 60.3° (range: 43-91°). This was corrected by 79% to mean 13° (p<0.001) with no patient losing >2° correction at follow-up. Mean preoperative Cobb levels of the thoracolumbar/lumbar curve were 6.3; mean levels of instrumented fusion were 7 (mean extent of fusion: preoperative Cobb angle + 0.7 levels). Mean preoperative thoracic kyphosis was 34.7° and lumbar lordosis 45.3°. Mean postoperative thoracic kyphosis was 36.6° and lumbar lordosis 43°. Mean theatre time was 3.8 hours, hospital stay 7.5 days and intraoperative blood loss 0.26 blood volumes. There were no neurological complications other than one temporary brachial plexus neuropraxia (recovered before patient discharge from hospital), no wound infections or detected non-union at follow-up. Mean preoperative SRS 22 score was 3.7; this was improved to 4.5 at 2-year follow-up (p=0.01). Pain and self-image demonstrated significant improvement (p=0.02, p=0.001 respectively) with mean satisfaction rate 4.8. Comparison between Groups 1 and 2 showed similar age at surgery but higher preoperative scoliosis in Group 2 (Group 1: 54°/Group 2: 65°, p=0.05). Preoperative AVR, TS and LIVA were similar between the 2 groups (p>0.05). Preoperative AVT was significantly higher in Group 2 (Group 1: 3.3 cm/Group 2: 5 cm, p=0.01). Conclusion. Pedicle screw instrumentation can achieve excellent correction of Lenke 5C idiopathic scoliosis which is maintained at follow-up. This is associated with high patient satisfaction and low complication rates. Greater preoperative AVT and scoliosis angle predicted the need for longer fusion both distally and proximally beyond the end vertebra of the preoperative Cobb angle

Purpose of the study. To compare the effectiveness of unilateral and bilateral pedicle screw techniques in correcting adolescent idiopathic scoliosis. Summary of Background Data. Pedicle screw constructs have been extensively used in the treatment of adolescent patients with idiopathic scoliosis. It has been suggested that greater implant density may achieve better deformity correction. However, this can increase the neurological risk related to pedicle screw placement, prolong surgical time and blood loss and result in higher instrumentation cost. Methods. We reviewed the medical notes and radiographs of 139 consecutive adolescent patients with idiopathic scoliosis (128 female-11 male, prospectively collected single surgeon's series). We measured the scoliosis, thoracic kyphosis (T5-T12), and lumbar lordosis (L1-L5) before and after surgery, as well as at minimum 2-year follow-up. SRS 22 data was available for all patients. Results. All patients underwent posterior spinal arthrodesis using pedicle screw constructs. Mean age at surgery was 14.5 years. We had 2 separate groups: in Group 1 (43 patients) correction was performed over 2 rods using bilateral segmental pedicle screws; in Group 2 (96 patients) correction was performed over 1 rod using unilateral segmental pedicle screws with the 2. nd. rod providing stability of the construct through 2-level screw fixation both proximal and distal. Group 1. Mean Cobb angle before surgery for upper thoracic curves was 37°. This was corrected by 71% to mean 11° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 65°. This was corrected by 71% to mean 20° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 60°. This was corrected by 74% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Mean preoperative thoracic kyphosis was 24° and lumbar lordosis 52°. Mean postoperative thoracic kyphosis was 21° and lumbar lordosis 50° (p>0.05). Mean theatre time was 5.5 hours, hospital stay 8.2 days and intraoperative blood loss 0.6 blood volumes. Complications: 1 transient IOM loss/no neurological deficit; 1 deep wound infection leading to non-union and requiring revision surgery; 1 rod trimming due to prominent upper end. Mean preoperative SRS 22 score was 3.9; this improved to 4.5 at follow-up (p<0.001). Pain and self-image demonstrated significant improvement (p=0.001, p<0.001 respectively) with mean satisfaction rate 4.9. Group 2. Mean Cobb angle before surgery for upper thoracic curves was 42°. This was corrected by 52% to mean 20° (p<0.001). Mean Cobb angle before surgery for main thoracic curves was 62°. This was corrected by 70% to mean 19° (p<0.001). Mean Cobb angle before surgery for thoracolumbar/lumbar curves was 57°. This was corrected by 72% to mean 16° (p<0.001). No patient lost >2° correction at follow-up. Preoperative scoliosis size for all types of curves correlated with increased surgical time (r=0.6, 0.4). Mean preoperative thoracic kyphosis was 28° and lumbar lordosis 46°. Mean postoperative thoracic kyphosis was 25° and lumbar lordosis 45° (p>0.05). Mean theatre time was 4.2 hours, hospital stay 8.4 days and intraoperative blood loss 0.4 blood volumes. Complications: 1 deep and 1 superficial wound infections treated with debridement; 1 transient brachial plexus neurapraxia; 1 SMA syndrome. Mean preoperative SRS 22 score was 3.7; this improved to 4.5 at follow-up (p<0.001). Pain, function, self-image and mental health demonstrated significant improvement (p<0.001 for all parameters) with mean satisfaction rate 4.8. Comparison between groups showed no significant difference in regard to age at surgery, preoperative and postoperative scoliosis angle for main thoracic and thoracolumbar/lumbar curves, as well as SRS scores and length of hospital stay. Better correction of upper thoracic curves was achieved in Group 1 (p<0.05), but upper thoracic curves in Group 2 were statistically more severe before surgery (p<0.05). Increased surgical time and blood loss was recorded in Group 1 (p<0.05, p=0.05 respectively). The implant cost was reduced by mean 35% in Group 2 due to lesser number of pedicle screws. Conclusion. Unilateral and bilateral pedicle screw instrumentation has achieved excellent deformity correction in adolescent patients with idiopathic scoliosis, which was maintained at follow-up. This has been associated with high patient satisfaction and low complication rates. The unilateral technique using segmental pedicle screw correction has reduced surgical time, intraoperative blood loss and implant cost without compromising surgical outcome for the most common thoracic and thoracolumbar/lumbar curves. The bilateral technique achieved better correction of upper thoracic scoliosis

The purpose of this study was to evaluate and compare the effect of short segment pedicle screw instrumentation and an intermediate screw (SSPI+IS) on the radiological outcome of type A thoracolumbar fractures, as judged by the load-sharing classification, percentage canal area reduction and remodelling.

We retrospectively evaluated 39 patients who had undergone hyperlordotic SSPI+IS for an AO-Magerl Type-A thoracolumbar fracture. Their mean age was 35.1 (16 to 60) and the mean follow-up was 22.9 months (12 to 36). There were 26 men and 13 women in the study group. In total, 18 patients had a load-sharing classification score of seven and 21 a score of six. All radiographs and CT scans were evaluated for sagittal index, anterior body height compression (%ABC), spinal canal area and encroachment. There were no significant differences between the low and high score groups with respect to age, duration of follow-up, pre-operative sagittal index or pre-operative anterior body height compression (p = 0.217, 0.104, 0.104, and 0.109 respectively). The mean pre-operative sagittal index was 19.6° (12° to 28°) which was corrected to -1.8° (-5° to 3°) post-operatively and 2.4° (0° to 8°) at final follow-up (p = 0.835 for sagittal deformity). No patient needed revision for loss of correction or failure of instrumentation.

Hyperlordotic reduction and short segment pedicle screw instrumentation and an intermediate screw is a safe and effective method of treating burst fractures of the thoracolumbar spine. It gives excellent radiological results with a very low rate of failure regardless of whether the fractures have a high or low load-sharing classification score.

Cite this article: Bone Joint J 2014;96-B:541–7.

Fractures of the odontoid peg are common spinal injuries in the elderly. This study compares the survivorship of a cohort of elderly patients with an isolated fracture of the odontoid peg versus that of patients who have sustained a fracture of the hip or wrist. A six-year retrospective analysis was performed on all patients aged > 65 years who were admitted to our spinal unit with an isolated fracture of the odontoid peg. A Kaplan–Meier table was used to analyse survivorship from the date of fracture, which was compared with the survivorship of similar age-matched cohorts of 702 consecutive patients with a fracture of the hip and 221 consecutive patients with a fracture of the wrist.

A total of 32 patients with an isolated odontoid fracture were identified. The rate of mortality was 37.5% (n = 12) at one year. The period of greatest mortality was within the first 12 weeks. Time made a lesser contribution from then to one year, and there was no impact of time on the rate of mortality thereafter. The rate of mortality at one year was 41.2% for male patients (7 of 17) compared with 33.3% for females (5 of 15).

The rate of mortality at one year was 32% (225 of 702) for patients with a fracture of the hip and 4% (9 of 221) for those with a fracture of the wrist. There was no statistically significant difference in the rate of mortality following a hip fracture and an odontoid peg fracture (p = 0.95). However, the survivorship of the wrist fracture group was much better than that of the odontoid peg fracture group (p < 0.001). Thus, a fracture of the odontoid peg in the elderly is not a benign injury and is associated with a high rate of mortality, especially in the first three months after the injury.

Cite this article: Bone Joint J 2014;96-B:88–93.

Transarticular screw fixation with autograft is an established procedure for the surgical treatment of atlantoaxial instability. Removal of the posterior arch of C1 may affect the rate of fusion. This study assessed the rate of atlantoaxial fusion using transarticular screws with or without removal of the posterior arch of C1. We reviewed 30 consecutive patients who underwent atlantoaxial fusion with a minimum follow-up of two years. In 25 patients (group A) the posterior arch of C1 was not excised (group A) and in five it was (group B). Fusion was assessed on static and dynamic radiographs. In selected patients CT imaging was also used to assess fusion and the position of the screws. There were 15 men and 15 women with a mean age of 51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6). Stable union with a solid fusion or a stable fibrous union was achieved in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid fusion, four (16%) a stable fibrous union and one (4%) a nonunion. In Group B, stable union was achieved in all patients, three having a solid fusion and two a stable fibrous union. There was no statistically significant difference between the status of fusion in the two groups. Complications were noted in 12 patients (40%); these were mainly related to the screws, and included malpositioning and breakage. The presence of an intact or removed posterior arch of C1 did not affect the rate of fusion in patients with atlantoaxial instability undergoing C1/C2 fusion using transarticular screws and autograft.

Cite this article: Bone Joint J 2013;95-B:972–6.

We describe the results of a prospective case series of patients with spondylolysis, evaluating a technique of direct stabilisation of the pars interarticularis with a construct that consists of a pair of pedicle screws connected by a U-shaped modular link passing beneath the spinous process. Tightening the link to the screws compresses bone graft in the defect in the pars, providing rigid intrasegmental fixation. We have carried out this procedure on 20 patients aged between nine and 21 years with a defect of the pars at L5, confirmed on CT. The mean age of the patients was 13.9 years (9 to 21). They had a grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The mean follow-up was four years (2.3 to 7.3). The patients were assessed by the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). At the latest follow-up, 18 patients had an excellent clinical outcome, with a significant (p < 0.001) improvement in their ODI and VAS scores. The mean ODI score at final follow-up was 8%. Assessment of the defect by CT showed a rate of union of 80%. There were no complications involving the internal fixation.

The strength of the construct removes the need for post-operative immobilisation.

We reviewed 15 consecutive patients, 11 women and four men, with a mean age of 48.7 years (37.3 to 62.6), who between July 2004 and August 2007 had undergone percutaneous sacroiliac fusion using hollow modular anchorage screws filled with demineralised bone matrix.

Each patient was carefully assessed to exclude other conditions and underwent pre-operative CT and MR scans. The diagnosis of symptomatic sacroiliac disease was confirmed by an injection of local anaesthetic and steroid under image intensifier control.

The short form-36 questionnaire and Majeed’s scoring system were used for pre- and post-operative functional evaluation. Post-operative radiological evaluation was performed using plain radiographs.

Intra-operative blood loss was minimal and there were no post-operative clinical or radiological complications. The mean follow-up was for 17 months (9 to 39). The mean short form-36 scores improved from 37 (23 to 51) to 80 (67 to 92) for physical function and from 53 (34 to 73) to 86 (70 to 98) for general health (p = 0.037). The mean Majeed’s score improved from 37 (18 to 54) pre-operatively to 79 (63 to 96) post-operatively (p = 0.014). There were 13 good to excellent results. The remaining two patients improved in short form-36 from a mean of 29 (26 to 35) to 48 (44 to 52). Their persistent pain was probably due to concurrent lumbar pathology.

We conclude that percutaneous hollow modular anchorage screws are a satisfactory method of achieving sacroiliac fusion.