This study evaluates the long-term survival of spinal implants after surgical site infection (SSI) and the risk factors associated with treatment failure. . A Kaplan-Meier survival analysis was carried out on 43 patients who had undergone a posterior spinal fusion with instrumentation between January 2006 and December 2008, and who consecutively developed an acute deep surgical site infection. All were appropriately treated by surgical debridement with a tailored antibiotic program based on culture results for a minimum of eight weeks. A ‘terminal event’ or failure of treatment was defined as implant removal or death related to the SSI. The mean follow-up was 26 months (1.03 to 50.9). A total of ten patients (23.3%) had a terminal event. The rate of survival after the first debridement was 90.7% (95% confidence interval (CI) 82.95 to 98.24) at six months, 85.4% (95% CI 74.64 to 96.18) at one year, and 73.2% (95% CI 58.70 to 87.78) at two, three and four years. Four of nine patients required re-instrumentation after implant removal, and two of the four had a recurrent infection at the surgical site. There was one recurrence after implant removal without re-instrumentation. Multivariate analysis revealed a significant risk of treatment failure in patients who developed sepsis (hazard ratio (HR) 12.5 (95% confidence interval (CI) 2.6 to 59.9); p < 0.001) or who had > three fused segments (HR 4.5 (95% CI 1.25 to 24.05); p = 0.03). Implant survival is seriously compromised even after properly treated surgical site infection, but progressively decreases over the first 24 months. Cite this article: Bone Joint J 2013;95-B:1121–6

Methods. In this study of patients who underwent internal fixation without fusion for a burst thoracolumbar or lumbar fracture, we compared the serial changes in the injured disc height (DH), and the fractured vertebral body height (VBH) and kyphotic angle between patients in whom the implants were removed and those in whom they were not. Radiological parameters such as injured DH, fractured VBH and kyphotic angle were measured. Functional outcomes were evaluated using the Greenough low back outcome scale and a VAS scale for pain. Results. Between June 1996 and May 2012, 69 patients were analysed retrospectively; 47 were included in the implant removal group and 22 in the implant retention group. After a mean follow-up of 66 months (48 to 107), eight patients (36.3%) in the implant retention group had screw breakage. There was no screw breakage in the implant removal group. All radiological and functional outcomes were similar between these two groups. Although solid union of the fractured vertebrae was achieved, the kyphotic angle and the anterior third of the injured DH changed significantly with time (p < 0.05). . Discussion. The radiological and functional outcomes of both implant removal and retention were similar. Although screw breakage may occur, the implants may not need to be removed. Take home message: Implant removal may not be needed for patients with burst fractures of the thoracolumbar and lumbar spine after fixation without fusion. However, information should be provided beforehand regarding the possibility of screw breakage. Cite this article: Bone Joint J 2016;98-B:109–16

Aims

Implant-related postoperative spondylodiscitis (IPOS) is a severe complication in spine surgery and is associated with high morbidity and mortality. With growing knowledge in the field of periprosthetic joint infection (PJI), equivalent investigations towards the management of implant-related infections of the spine are indispensable. To our knowledge, this study provides the largest description of cases of IPOS to date.

We have studied two matching cohorts of patients treated by Dynesys flexible stabilisation with and without hydroxyapatite (HA) coating of the pedicle screws. From our series of 570 Dynesys procedures, we studied patients with HA coated screws with a minimum one year follow-up. Patients were entered prospectively and followed up at 6 weeks, 3, 6, and 12 months and annually thereafter. Plain radiographs were obtained annually. 58 patients (26 males, 32 females, mean age 55 years at surgery) underwent Dynesys stabilisation with HA coated screws. The data was compared with 69 patients who underwent Dynesys stabilisation with non-coated pedicle screws between 2004 and 2006 (26 male, 53 female, mean age 54 years). Outcome measures were screw loosening, breakage, implant removal or revision. A total of 320 HA coated pedicle screws were inserted. 12 patients were lost to follow-up. 2 patients underwent subsequent level extension, and 2 had their implants removed. There were four screw breakages in three patients, all affecting S1 screws. There was no evidence of screw loosening in any patient. In the non-HA coated group 354 pedicle screws were inserted. 5 patients required revision or subsequent surgery. 12 patients had screw loosening and required implant removal. There was a significant improvement of anchorage of the HA coated screws. Change to HA coating was investigated because of high loosening in plain screws. The improvement has been highly significant. Flexible stabilisation is a better model than fusion because the implant remains under constant load. Disclosure: The authors did not receive any outside funding in support of preparation of this work

Objective. From our series of 570 Dynesys flexible stabilisation procedures, we studied two prospective series of patients with a minimum one-year follow-up comparing uncoated and hydroxyapatite-coated (HA) screws. Methods. Patients were entered prospectively and followed up at 6 weeks, 3, 6, and 12 months and annually thereafter. Plain radiographs were obtained annually. 58 patients who underwent Dynesys stabilisation with HA coated screws (312 screws) were evaluated. The data was compared with 71 patients who underwent Dynesys stabilisation with non-coated pedicle screws (366 screws). Outcome measures were screw loosening, breakage, implant removal or revision. Follow up was 96 %. Results. In the HA coated group there were five screw breakages in three patients, all affecting S1 screws. There was evidence of loosening in one patient. In the non-HA coated group there were two cases of infection, both had their implants removed. Further 11 patients had screw loosening and required implant removal. There was a significant improvement of anchorage of the HA coated screws. There was no correlation between numbers of level stabilised, or previous surgery and screw loosening. Average time to revision surgery for loosening was 23 months in the non-coated group. Screw fractures occurred at 11 months in the HA coated group. There was no correlation between screw loosening or fracture and gender or age. Conclusions. Change to HA coating was investigated because of high loosening in plain screws. Secure pedicle screw fixation is crucial in dynamic stabilisation as the implant remains under constant load. This study demonstrated the significant improved anchorage of HA coated pedicle screws in dynamic posterior stabilisation of the lumbar spine. HA coating has eliminated the problem of screw loosening irrespective of gender, age, number of level stabilised or whether there was previous lumbar surgery

Aims

The outcome following the development of neurological complications after corrective surgery for scoliosis varies from full recovery to a permanent deficit. This study aimed to assess the prognosis and recovery of major neurological deficits in these patients, and to determine the risk factors for non-recovery, at a minimum follow-up of two years.

Purpose of Study. To review the medium-term results of the Dynesys stabilisation system used in 113 consecutive patients with discogenic back pain. Methods and Results. 113 consecutive patients with discogenic back pain were treated with Dynesys as the sole intervention. Inclusion criteria included mri proven disc degeneration and an improvement in symptoms following an injection into the disc with local anaesthetic and steroid (spinal disc probing). Patients were followed up for a minimum of 5 years, with outcome measures including SF-36, Oswestry disability index (ODI) and visual pain analogue scores (VPAS). Additional factors reviewed included previous spinal operations, complications, loosening and revision rates with subsequent outcomes. Mean pre-operative ODI was 49.5, SF-36 was 37.6 and VPAS back pain was 60.9. At one year post operatively, these scores were 36.9, 49.4 and 39.8, at five years follow up, the scores were 33.3, 51.8 and 40.1 respectively. We note wide variations in our results. Several significant factors appear to contribute to the outcome of surgery. These include undergoing surgery before the age of 43, no more than 2-level disc degeneration, leg pain less than VPAS 4, and no previous spinal surgery. 19 patients had screw loosening evident on plain film x-rays (4 requiring removal), and 2 patients had screw breakages. 19 patients had implant removal for failure and 2 patients went on to have a fusion procedure. Discussion. Dynesys has a role in the treatment of discogenic back pain. Patient selection is important to outcome and we have identified several pre-operative factors that increase the likelihood of success. The effects are present at 1 year postoperatively and are maintained for at least 5 years. There is a significant screw loosening rate and our series had a 17% revision rate

Background. Wallis implant was developed in 1986 to stiffen unstable operated degenerate lumbar segments while preserving some intervertebral mobility. The long-term results of first-generation Wallis implant from developers were promising. However, documentation pertaining to safety and efficacy of second generation Wallis implant is sparse in literature. Purpose. The objective of this study was to assess the clinical outcome of the second generation Wallis interspinous device for degenerative lumbar disc disease. Study design. Prospective consecutive single surgeon series. Methods. Patients were selected according to recommendations by developers of Wallis implant. Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS) were used to assess patient outcomes. Implant failure was determined by disc recurrence, implant removal and revision. Results. 25 patients (13 male, 12 female) with mean age of 51 years (range 47-76) had Wallis implantation (22 one level and 3 two level). Clinical outcome data at average of 60 months (47-76) available for 24 patients (96% FU). Mean ODI scores decreased from 59.1% pre-operatively to 24.7 and 40.5% at 2 years and 5 years follow up, respectively. 34.4 points change from baseline at 2 years and 18.6 points at final follow-up. Mean VAS scores decreased from 7.2 to 3.0 and 4.8 cm for back pain at 2 and 5 years; from 6.8 to 3.8 and 4.2 cm for leg pain at 2 and 5 years follow-up, respectively. Taking a 24 point change in ODI as representing good outcome 96 % (24 patients) of study subjects achieved this at 2 years. Taking a 16 point change in ODI as representing minimum change needed for clinical success 40% (10 patients) failed to achieve this at 5 years. 2 revisions have occurred so far (8% failure rate). Conclusion. The results of our series indicate that the study device is safe and efficacious in the treatment of symptomatic lumbar degenerative discs. However, good clinical outcome obtained at early years is not maintained in medium-term. Interest Statement. There was no commercial support or funding of any sort

Aims

High-grade dysplastic spondylolisthesis is a disabling disorder for which many different operative techniques have been described. The aim of this study is to evaluate Scoliosis Research Society 22-item (SRS-22r) scores, global balance, and regional spino-pelvic alignment from two to 25 years after surgery for high-grade dysplastic spondylolisthesis using an all-posterior partial reduction, transfixation technique.

We compared the clinical, radiological and quality-of-life outcomes between hybrid and total pedicle screw instrumentation in patients undergoing surgery for neuromuscular scoliosis. A matched comparison using prospectively collected data was undertaken. A total of 66 patients underwent posterior or anteroposterior correction and fusion with hybrid (n = 33, mean age at surgery 15.8 years (9.10 to 19.6)) or total pedicle screw instrumentation (n = 33, mean age 14.7 years (7.0 to 20.7)) with a minimum follow-up of two years. The major curve pre-operatively was a mean of 87° (sd 29, 25° to 141°) and 81° (sd 18, 47° to 116°) in the hybrid and total pedicle screw groups, respectively (p = 0.29) and at a minimum of two years it was 33° (sd 20; 2° to 87°) and 20° (sd 12; 1° to 55°), respectively (p = 0.0016). The mean correction of the major curve was 59% (41% to 88%) in the hybrid and 75% (43% to 99%) in the total pedicle screw groups at two-year follow-up (p = 0.0011). The mean operating time was 7.45 hours (sd 2.18) and 6.04 hours (sd 1.71) in the hybrid and total pedicle screw groups, respectively (p = 0.001), and the mean intra-operative blood loss was 3760 ml (sd 2790) and 1785 ml (sd 1110), respectively (p = 0.001).

Total pedicle screw instrumentation provided shorter operating times, less blood loss and better correction of the major curve compared with hybrid constructs in patients undergoing surgery for neuromuscular scoliosis.

The purpose of this study was to determine whether patients with a burst fracture of the thoracolumbar spine treated by short segment pedicle screw fixation fared better clinically and radiologically if the affected segment was fused at the same time. A total of 50 patients were enrolled in a prospective study and assigned to one of two groups. After the exclusion of three patients, there were 23 patients in the fusion group and 24 in the non-fusion group. Follow-up was at a mean of 23.9 months (18 to 30). Functional outcome was evaluated using the Greenough Low Back Outcome Score. Neurological function was graded using the American Spinal Injury Association Impairment Scale. Radiological outcome was assessed on the basis of the angle of kyphosis.

Peri-operative blood transfusion requirements and duration of surgery were significantly higher in the fusion group (p = 0.029 and p < 0.001, respectively). There were no clinical or radiological differences in outcome between the groups (all outcomes p > 0.05). The results of this study suggest that adjunctive fusion is unnecessary when managing patients with a burst fracture of the thoracolumbar spine with short segment pedicle screw fixation.

Between January 1990 and December 2000 we carried out 226 SB Charité III disc replacements for lumbar disc degeneration in 160 patients. They were reviewed at a mean follow-up of 79 months (31 to 161) to determine the clinical and radiological outcome. The clinical results were collected by an independent observer, who was not involved in patient selection, treatment or follow-up, using a combination of outcome measures, including the Oswestry Disability Index. Pain was recorded using a visual analogue score, and the most recent radiographs were reviewed.

Survival of the device was analysed by the Kaplan-Meier method and showed a cumulative survival of 35% at 156 months when radiological failure was taken as the endpoint. The mean improvement in the Oswestry disability index scores after disc replacement was 14% (6% to 21%) and the mean improvement in the pain score was 1.6 (0.46 to 2.73), both falling below the clinically significant threshold. Removal of the implant was required in 12 patients, four because of implant failure.

These poor results indicate that further use of this implant is not justified.