Purpose: Several studies have been directed toward using mesenchymal stem cells (MSCs) from osteoarthritic (OA) patients for cartilage or disc repair because these patients are the ones that will require a source of autologous stem cells if biological repair of tissue lesions is to be a therapeutic option. A major drawback of current cartilage and intervertebral disc tissue engineering repair is that these cells rapidly express type X collagen, a marker of late stage chondrocyte hyperthrophy implicated in endochondral ossification. However, a novel plasma-polymerized thin film material, named nitrogen-rich plasma-polymerized ethylene (PPE:N), is able to inhibit type X collagen expression in committed MSCs. The specific aim of this study was to determine if the suppression of type X collagen by PPE:N is maintained when MSCs are transferred to pellet cultures in chondrogenic defined media.

Method: MSCs were obtained from aspirates from the intramedullary canal of donors undergoing total hip replacement for OA using a protocol approved by the Research Ethics Committee of our institution. Cells were then expanded for 2–3 passages in DMEM high glucose supplemented with 10% fetal bovine serum, 100 U/ml penicillin, and 100 μg/ml streptomycin, and finally cultured on polystyrene (PS) cell culture dishes or PPE: N surfaces for 3 and 7 days. Cells were transferred for 3 additional days in a chondrogenic serum free media (DMEM high glucose supplemented with 2 mM L-glutamine, 20 mM HEPES, 45 mM NaHCO3, 100 U/ml penicillin, 100 μg/ml streptomycin, 1 mg/ml bovine serum albumin, 5 μg/ml insulin, 50 μg/ml ascorbic acid, 5 ng/ ml sodium selenite, 5 μg/ml transferrin) in pellet culture or on PS cell culture dishes. Cells were then lysed and proteins were separated on 4–20% acrylamide gels and transferred to nitrocellulose membranes. Type X collagen was detected by Western blot; GAPDH expression was used as an internal control for protein loading.

Results: Results showed that type X collagen protein was expressed in MSCs from OA patients cultured on polystyrene but was suppressed when cultured on PPE: N. Since defined chondrogenic medium are commonly used in pellet culture to promote in vitro chondrogenesis, we then investigated the effect of transferring cells pre-cultured on PPE:N into pellet culture on type X collagen expression. However, the decreased type X collagen expression was not maintained in these conditions and that the expression returned to control values. The decreased type X collagen expression was maintained when the cells were cultured on PS cell culture dishes.

Conclusion: The use of MSCs is promising for tissue engineering of cartilage and intervertebral disc. The present study confirmed the potential of PPE:N surfaces in suppressing type X collagen expression in MSCs from OA patients. However, when MSCs stem cells are transferred to pellet cultures, type X collagen is rapidly re-expressed suggesting that pellet cultures may not be suitable for chondrogenesis of MSCs from OA patients.

Patient outcomes using the Scoliosis Research Society (SRS) questionnaire after thoracoscopic and posterior surgical techniques for thoracic idiopathic scoliosis were compared after > 2 years post-op. Additional comparisons were made with non-operated scoliosis and normal patients. Our objective was to determine if scoliosis surgery and surgical technique used to treat a cohort of patients with the same type of scoliosis deformity affects patient outcome. The SRS-24 questionnaire was prospectively administered to 4 groups of patients:

42 patients with thoracic idiopathic scoliosis who underwent thoracoscopic instrumented fusion surgery (thoracoscopic group);

The 2 surgical groups were comparable with regards to age at surgery, pre-op Cobbo and follow-up. SRS-24 domian scores were computed for all 4 groups and were compared on SPSSv13 software. Our results show the thoracoscopic group having a significantly smaller mean post-op Cobbo (17° vs 25.1°, respectively; p< .001), which was achieved using less fusion segments (7 vs 9.3 segments, respectively; p< .001). The mean Cobbo of the scoliosis control group was significantly larger than the post-op Cobbo of the thoracoscopic group (p< .001), and was comparable to the post-op Cobbo of the posterior group. Comparing the 2 surgical groups, the thoracoscopic group showed trends towards better scores in 4 of the SRS-24 domains compared to the posterior group, but this only reached statistical significance for the satisfaction domain (p< .05). When comparing the 4 groups, Pain scores of both surgical groups were similar to those who did not have surgery, and were worse than normal patients (p< .0001); Self-image scores after surgery were higher than those who did not have surgery(p< .05) and were comparable to normal patients; Function and Activity scores of the thoracoscopic group was significantly inferior to the scoliosis control group (p< .05). Our study demonstrates that > 2 years after surgery, both thoracoscopic & posterior surgery resulted in pain scores that were similar to patients with scoliosis that did not have surgery, and were worse than the normal group. However, both surgical techniques resulted in self-image scores that are comparable to normal individuals despite a difference in post-op Cobbo. When comparing the two surgical techniques, the SRS-24 showed no difference between the 2 surgical techniques, except for patient satisfaction which was better in the thoracoscopic group.

Study design: Long-term retrospective study of the low grade isthmic Spondylolisthesis treated by means of instrumented posterolateral fixation in adults.

Objective: To evaluate clinical and functional survival of surgical treatment of the espondylolisthesis after minimum 10 years of follow-up. To study the radiologic behaviour of the fused and the adjacent level.

Summary of background: It’s been suggested in many different series that posterolateral instrumented fusion is not always capable to improve the lumbar pain neither to stabilize a vertebral segment if the anterior column is not supported. The need to perform and interbody fusion in the surgical treatment of isthmic spondilolysthesis is still unknown.

Material and method: From a total of 42 patients operated by low grade isthmic espondylolisthesis, it’s been obtained a clinic and radiological follow up in 31 patients, 19 females and 12 males. The average age at the moment of surgery was 34.9 years and in the last review was 46.5 years. The average follow up has been 11.8 years. Pain and functional disability was quantified by a visual analogical Scale (VAS) and the Oswestry Disability Index (ODI). Quality of life was assessed by the SF-36. The preoperative and postoperative percentage of slip and lumbosacral kyphosis was evaluated in serial radiographs at the fused level. The intervertebral disc height and dynamic behaviour was evaluated at the adjacent level.

Results: Spondylolisthesis was present at L5 in 24 patients, L4 in 6 patients and at L3 in 1 patient. In the 87% of cases the fusion was one level and the 3% was two levels. The mean (range) anterior slip at postoperative was 21.9%, and 23.1% at the final follow up. The average angle for the lumbosacral kyphosis was 19.4° in the postoperative and 19.5° in the follow up. The Oswestry Disability Index scores average at follow up was 13,6. 75.8% of patients were considered with a minimum disability and 17.2% with a moderate disability. The 67.7% of the patients develop rewarded activities, the 25.6% develop domestic tasks and the 6.45% are in a disability situation. There was no statistically significant difference between the study population SF-36 scores and those of the general population, same age and gender, in any of the eight domains.

Conclusions: Long-term clinical and radiographic outcomes after “in situ” posterolateral instrumented fusion of adult low-grade Spondylolisthesis were satisfactory. This study further confirms that such surgery is appropriate for these selected patients.

Posterior instrumented fusion is an established surgical treatment for majority of AIS cases. In the past decade, thoracoscopic instrumentation and fusion has emerged as a viable alternative to conventional posterior techniques in situations that require selective thoracic fusion. Most reports comparing the two techniques have focused on physician-based outcomes such as curve correction and maintenance of the surgical correction with both methods being comparable. Recently, the SRS-24 has been used to evaluate patient-based outcomes after scoliosis surgery. The instrument assesses seven equally-weighted domains that look at pain, self-image, general function, activity level, change in self-image and function post-surgery, and satisfaction with the procedure. It has been used to evaluate differences between AIS and normal patients, and in different degrees of AIS deformity. The instrument has not been used in comparing different methods of surgical treatment for similar curve types.

We applied the SRS-24 prospectively to our patients who had undergone either thoracoscopic (TG) or posterior (PG) instrumented fusion, and had been followed-up for at least 12-months postoperatively. There were 42 patients in TG and 42 patients in PG. The mean age at time of surgery, pre-operative Cobb angles, and number of spinal segments fused were similar in both groups. The mean follow-up period at the time the SRS instrument was administered was 26 (± 13.5) months for TG and 30.7 (± 12.1) months for PG. The postoperative Cobb angle on the latest follow-up was significantly better for TG compared to PG (17 versus 25.1 degrees, respectively; p < .001). Upon comparing the SRS domain scores between both groups, a significant difference was noted only in the patient satisfaction domain with TG scoring better than PG (p < .02).

The first four SRS-24 domain scores for TG and PG were also compared to the corresponding domain scores of 97 patients who had scoliosis but were not candidates for surgery (SG), as well as to the scores of 72 patients who did not have scoliosis (NG). SG, TG, and PG were comparable with regards to pain and all three were significantly lower compared to NG (F=14.828, p < .0001).

General function and activity level scores of TG were significantly lower compared to the other three groups (F=4.870, p < .003 and F=4.793, p < .003, respectively). Despite this, the self-image domain scores of both TG and PG were not significantly different from NG, with SG scoring significantly poorer compared to the other three groups (F=3.183, p < .02).

In summary, thoracoscopic instrumented fusion resulted in better curve correction compared to posterior instrumented fusion and was achieved with less spinal segments being fused. This was despite the finding that patients who underwent thoracoscopic surgery had lower physical function and activity level scores. Additionally, both surgical techniques resulted in patients whose perception of themselves was comparable to those patients who did not have scoliosis. The SRS-24 was not able to detect any differences between the two surgical methods in all domains except for overall patient satisfaction which was significantly better in the thoracoscopic group.