Lumbar fusion surgery is an established procedure for the treatment of several spinal pathologies. Despite numerous techniques and existing devices, common surgical trends in lumbar fusion surgery are scarcely investigated. The purpose of this Canada-based study was to provide a descriptive portrait of current surgeons’ practice and implant preferences in lumbar fusion surgery while comparing findings to similar investigations performed in the United Kingdom.

Canadian Spine Society (CSS) members were sampled using an online questionnaire which was based on previous investigations performed in the United Kingdom. Fifteen questions addressed the various aspects of surgeons’ practice: fusion techniques, implant preferences, and bone grafting procedures. Responses were analyzed by means of descriptive statistics.

Of 139 eligible CSS members, 41 spinal surgeons completed the survey (29.5%). The most common fusion approach was via transforaminal lumber interbody fusion (TLIF) with 87.8% performing at least one procedure in the previous year. In keeping with this, 24 surgeons (58.5%) had performed 11 to 50 cases in that time frame. Eighty-six percent had performed no lumbar artificial disc replacements over their last year of practice. There was clear consistency on the relevance of a patient specific management (73.2%) on the preferred fusion approach. The most preferred method was pedicle screw fixation (78%). The use of stand-alone cages was not supported by any respondents. With regards to the cage material, titanium cages were the most used (41.5%). Published clinical outcome data was the most important variable in dictating implant choice (87.8%). Cage thickness was considered the most important aspect of cage geometry and hyperlordotic cages were preferred at the lower lumbar levels. Autograft bone graft was most commonly preferred (61.0%). Amongst the synthetic options, DBX/DBM graft (64.1%) in injectable paste form (47.5%) was preferred.

In conclusion, findings from this study are in partial agreement with previous work from the United Kingdom, but highlight the variance of practice within Canada and the need for large-scale clinical studies aimed to set specific guidelines for certain pathologies or patient categories.

Introduction

Positive expectations can increase compliance with treatment and realistic expectations may reduce postoperative dissatisfaction. Recently there are articles regarding expectations of patients from their TKA in western literature and only few articles based on Korean populations which don't encompass the whole spectrum of expectations in Korean patients. In all those articles based on pre-operative expectation, results were applied to whole expectation category uniformly not differentially. We aimed to document the pre-operative expectations in Korean patients undergoing total knee replacement using an established survey form and to determine whether expectations were influenced by socio-demographic factors and socio-demographic factors influences expectation items in particular category uniformly or differentially.

Introduction

Unicompartmental knee arthroplasty (UKA) is becoming an increasingly popular option in single compartment osteoarthritis. As a result, diverse re-operations including revisions to total knee arthroplasty (TKA) has also increase. The objective of this study is to investigate the distribution of causes of re-operations after UKA and to analyze the types of re-operations.

To evaluate the effect of wait time to surgery on patient derived generic and disease-specific functional outcome following lumbar surgery.

Study cohort of seventy patients undergoing elective posterior lumbar spinal surgery for degenerative conditions. Prospectively collected SF-36 and Oswestry Disability questionnaires administered preoperatively, six weeks, six months, one year postoperatively. Time intervals from onset of symptoms to initial consultation by family physician through investigations, spinal surgical consultation and time spent on the surgical waiting list to surgery quantified. Time intervals compared to patient-specific improvements in reported outcome following surgery using Cox-Regression analysis. The effect of patient and surgical parameters on wait time was evaluated using median time as a reference for patients with either a longer or shorter wait.

Patient follow-up completed in fifty-three (76%). Improvements in patient derived outcome were observed comparing post-operative to pre-operative baseline scores (p< 0.05). The greatest improvements were observed in aspects relating to physical function and pain. A longer wait to surgery was associated with less improvement in surgical outcome (p< 0.05, SF-36 domains BP, GH, RP, VT, and Physical Component Scores). The greatest impact observed was a prolonged surgical wait-list time on SF-36 PCS scores following surgery (Hazard’s ratio 3.53). Patients requiring spinal fusion had a longer wait when compared to those not requiring fusion (p< 0.05).

A longer wait time to spinal surgery can negatively influence surgical results as quantified by patient derived functional outcome measures. Surgery resulted in the greatest improvement in pain severity and physical aspects of function, however, these areas also appeared the most impacted by a longer wait to surgery.

Vertebroplasty (VP) is currently used to improve spinal stability in patients with vertebral metastases. This study assessed the effects of Laser Induced Thermo Therapy (LITT), a minimally invasive technique used to ablate tumor tissue prior to vertebroplasty. Load-induced canal narrowing (LICN) was measured pre and post-vertebroplasty in twelve paired spinal motion segments with simulated lytic metastases. LICN improved post-vertebroplasty for all specimens treated with LITT. In all specimens, cement location was an important factor in post-vertebroplasty stability. Reduction of the tumor volume pre-vertebroplasty resulted in more reliable defect filling.

To investigate the effect of tumor ablation using Laser Induced Thermo Therapy (LITT) prior to vertebroplasty (VP) on cement distribution and vertebral stability.

Tumor volume reduction using LITT prior to cement injection improves defect filling and consistently reduces Load Induced Canal Narrowing (LICN).

A simple, minimally invasive procedure providing accurate tissue destruction pre-vertebroplasty may result in more reliable cement fill, reduce cement extravasation and improve post-vertebroplasty stability.

Following verebroplasty, LICN improved in all specimens treated with LITT and in those VP alone specimens with cement located posterior to the tumor tissue (33%). LITT treated vertebrae exhibited a trend toward reduced posterior wall motion post-vertebroplasty (LICN=29.7±27.1%) versus specimens treated with VP alone (LICN=248.7±253%). In the LITT+VP group, cement was fully contained within the vertebral body while cement extravasation into the canal was noted in 33% of the specimens treated without LITT.

Twelve paired cadaveric thoracolumbar spinal motion segments with simulated lytic metastases were randomized for treatment with VP alone or LITT+VP. In the LITT+VP group, a laser fibre inserted through a transpedicular approach was used to ablate the tumor tissue prior to cement injection. The specimens were axially loaded to 800N pre and post-treatment. LICN was used as a measure of vertebral stability. Cement location was assessed post-testing through axial sectioning. Location of cement is an important factor in determining post-VP stability. Vertebroplasty is effective in decreasing LICN if the tumor is ablated or surrounded posteriorly with cement.

Funding: USAMRMC DAMD 17–00–1–0693

Spinal procedures relying on percutaneous pedicle cannulation (PPC) are becoming increasingly common. The accuracy of PPC using currently available two-dimensional intraoperative imaging such as conventional C-arm fluoroscopy (CF) or computer-assisted fluoroscopy (2D_Nav) has not been evaluated. Following PPC of cadaveric spines (T4-S1) using CF and 2D_Nav, by a novice and clinical expert, the number and degree of pedicle breaches was assessed by CT. Accuracy using CF or 2D_Nav was equivalent and comparable to published reports for open pedicle cannulation. However, clinical expertise was the significant determinant of improved accuracy rather than technological factors.

To assess the accuracy of percutaneous pedicle cannulation(PPC) using currently available two-dimensional intraoperative imaging (C-arm fluoroscopy (CF) or computer-assisted fluoroscopy (2D_Nav)) for two levels of clinical expertise.

Accuracy using CF or 2D_Nav was equivalent and comparable to published reports for open pedicle cannulation. Main determinant of PPC accuracy is clinical experience, rather than technological factors.

Current technology cannot replace the need for rigorous training required to gain skill in percutaneous pedicle procedures.

Using an eleven-gauge bone biopsy needle, sixty randomized pedicles(two cadavers, T4–S1) were cannulated using CF or 2D-Nav by a staff spine surgeon or a third year orthopaedic resident. Pedicles for each vertebra were paired as internal controls for technique. After insertion of the biopsy needle, a 1.5mm aluminum tube was inserted through the needle as a marker. Using fine cut CT scans the position of each tube was assessed using a predefined grading system based on tube location relative to pedicle, direction of breech, trajectory, and position in vertebral body. Minimum score was three(ideal) and maximum was fourteen(gross misplacement). There were significantly (p< 0.05) more pedicle breaches for the resident (four CF, four 2D-Nav) compared to staff (one 2D-Nav). All breaches were thoracic with no statistical difference between number of breaches using CF and 2D-Nav for either skill group. Grade of breaches for CF (8.8) and 2D-Nav (9.4) were statistically similar. Main sources of error included poor image quality, image misinterpretation and biopsy needle flexibility causing navigational maltracking.

In percutaneous vertebroplasty, clinically significant complications occur predominantly in patients with spinal metastases. This higher rate of complication may be associated with increased pressurization that has been reported due to the presence of lytic tissue during vertebroplasty. To date, there has been no research investigating techniques aimed at reducing this pressurization. This study investigated the potential of tumour volume reduction using laser induced thermo therapy ablation within the metastatic spine. This novel technique proved to be capable of efficient tissue shrinkage (average 60%) with little or no pressurization (average 1.3mmHg) and moderate levels of temperature elevation (average increase of 15.1°C).

This study aims to investigate the potential of minimally invasive tumour volume reduction using laser induced thermo therapy ablation within the metastatic spine.

Volume reduction of tumour tissue prior to cement injection may provide a method to reduce pressurization, reduce the likelihood of tumour extravasation and improve cement fill during percutaneous vertebroplasty.

In percutaneous vertebroplasty, clinically significant complications occur predominantly in patients with spinal metastases (10%).

Laser-induced thermo therapy condensed and coagulated the simulated tumour. Volume shrinkage of the tumour tissue averaged 60%. Pressures generated within the vertebral body only rose an average of 1.3mmHg during the procedure. Maximum temperatures on the posterior body wall increased by 15.1°C, with average temperatures 6.8°C above the baseline.

A simulated lytic defect created using breast tissue was introduced into the vertebral body of a calf spine to model a metastatically involved vertebra. A pre-charred surgical fibre coupled to a diode laser delivering 1750J of energy was inserted through an eleven-guage needle into the centre of the tumour using an intrapedicular technique. During treatment, the temperature at the posterior body wall and intravertebral pressure were measured. Following ablation, the volume of the remaining tissue was measured.

The results suggest that this novel technique is capable of reproducible, uniform, and effective tissue destruction with little to no pressurization and moderate levels of temperature elevation. Both pressures and temperatures generated during our study were lower than reported values during percutaneous vertebroplasty and suggest little risk of complications.

Introduction: Flexion distraction injuries (FDI)of the thoracic and lumbar spine can be stabilized with a short construct spanning one motion-segment. This fracture is functionally defined by failure of the posterior and middle columns in tension and the anterior column in compression or tension. Treatment of a predominantly bony injury with minimal deformity (Chance type) is usually non-operative. Intra-abdominal pathology, and ligamentous spinal instability are relative indications for surgery. Deformity of greater than 17 degrees of kyphosis has a poor prognosis when treated conservatively, and represents true instability in vitro. Surgical treatment is mainly through a posterior approach with instrumentation. Which construct to use and the number of motion segments to include is controversial. Multi-level instrumentation techniques both in distraction and compression have been used as well as shorter constructs, particularly in the lumbar spine. We addressed the efficacy of single motion-segment fixation by evaluating the radiographic and functional results of this treatment technique.

Methods: All patients diagnosed with a FDI were prospectively identified over a 48 month period. Non-operatively treated fractures were excluded. Other spine fractures were excluded. Demographics, comorbidity, neurological status, operative details and complications were recorded. Radiographic reviewers were blinded to the functional outcome of the patient and the time of follow-up. The Oswestry Functional Assessment Questionnaire was administered by mail.

Results: Twenty-one eligible patients were identified. A significant (p< 0.0001) correction of deformity was achieved, from a mean preoperative kyphosis of 10.1 degrees to a mean postoperative lordosis of 0.9 degrees. No loss of correction occurred. The mean Oswestry score was 11.5, with 88% of patients having minimal disability. One patient died from unrelated morbidity.

Conclusions: Hoshikawa etal showed in vitro how compression forces alone can create FDI. Compression without flexion causes burst fractures. With moderate flexion there is FDI with anterior body compression. With increasing flexion FDI becomes entirely distractive. As the forces are concentrated at a single point, reconstruction only requires that this location be addressed. As all FDI are created by the same mechanism, regardless of structures injured only short segment fixation is required.

We have demonstrated in FDI, single level fixation is biomechanically sound. Multilevel instrumentation creates loss of adjacent level motion segments. This is not necessary. The absence of a control group precludes absolute conclusions. Nonetheless most patients reported minimal disability related to their back and had excellent radiological outcomes. This study demonstrates that posterior reduction and stabilization of a single motion-segment for FDI can adequately stabilize the spine and lead to excellent functional outcomes.

INTRODUCTION: Flexion distraction injuries (FDI) of the thoracic and lumbar spine can be stabilised with a short construct spanning one motion-segment. This fracture is functionally defined by failure of the posterior and middle columns in tension and the anterior column in compression or tension. Treatment of a predominantly bony injury with minimal deformity (Chance type) is usually non-operative. Intra-abdominal pathology, and ligamentous spinal instability are relative indications for surgery. Deformity of greater than 17 degrees of kyphosis has a poor prognosis when treated conservatively, and represents true instability in vitro. Surgical treatment is mainly through a posterior approach with instrumentation. Which construct to use and the number of motion segments to include is controversial. Multi-level instrumentation techniques both in distraction and compression have been used as well as shorter constructs, particularly in the lumbar spine. We addressed the efficacy of single motion-segment fixation by evaluating the radiographic and functional results of this treatment technique.

METHODS: All patients diagnosed with a FDI were prospectively identified over a 48 months period. Non-operatively treated fractures were excluded. Other spine fractures were excluded. Demographics, co-morbidity, neurological status, operative details and complications were recorded. Radiographic reviewers were blinded to the functional outcome of the patient and the time of follow-up. The Oswestry Functional Assessment Questionnaire was administered by mail.

RESULTS: Twenty-one eligible patients were identified. A significant (p< 0.0001) correction of deformity was achieved, from a mean pre-operative kyphosis of 10.1 degrees to a mean post-operative lordosis of 0.9 degrees. No loss of correction occurred. The mean Oswestry score was 11.5, with 88% of patients having minimal disability. One patient died from unrelated morbidity.

CONCLUSIONS: Hoshikawa et al showed in vitro how compression forces alone can create FDI. Compression without flexion causes burst fractures. With moderate flexion there is FDI with anterior body compression. With increasing flexion FDI becomes entirely distractive. As the forces are concentrated at a single point, reconstruction only requires that this location be addressed. As all FDI are created by the same mechanism, regardless of structures injured only short segment fixation is required.

We have demonstrated in FDI, single level fixation is biomechanically sound. Multilevel instrumentation creates loss of adjacent level motion segments. This is not necessary. The absence of a control group precludes absolute conclusions. Nonetheless most patients reported minimal disability related to their back and had excellent radiological outcomes. This study demonstrates that posterior reduction and stabilisation of a single motion-segment for FDI can adequately stabilise the spine and lead to excellent functional outcomes.

The purpose of the study was to evaluate the functional outcome and recurrent dislocation rate in patients who have undergone arthroscopic shoulder stabilization with a bioabsorbable fixation device, Suretac (Acufex Microsurgical). The role of thermal capsular shrinkage was also investigated.

Between June 1996 and June 2000, 78 consecutive patients (80 shoulders) at our hospital underwent arthroscopic stabilization with Suretac fixator by our senior author (DM). Twenty-one performed for acute post-traumatic dislocation (defined as first time dislocation), 41 for recurrent dislocations, 14 for SLAP lesions and four atraumatic multidirectional instability. Patients were followed up by an independent observer (FL) after a mean of 35 months (range: 9–62 months). The follow up examination included the modified Rowe and Zarins score, the American Shoulder and Elbow Surgeons score and the Constant score. The strength of lateral elevation as advocated in the Constant score was measured by the Nottingham Mecmesin Myometer.

The overall re-dislocation rate after surgery was 14% (11 patients). This occurred after an average period of 23 months (range: 12–37 months) following the initial stabilization procedure. One patient also reported recurrent subluxation though without frank dislocation. The re-dislocation for patients with acute dislocation was 9%, 15% for recurrent dislocation, 14% for SLAP lesions and 25% for those with atraumatic multidirectional instability. 3 of the 19 patients who underwent arthroscopic stabilization and thermal capsular shrinkage also re-dislocated. Four of the 10 patients who were aged 18 or under at the time of surgery, re-dislocated after an average period of 18 months following the operation.

Our study shows that the functional outcome and recurrence rate of Suretac stabilization compare favorably to other arthroscopic repair techniques using nonabsorbable suture anchors. The results appear to be better in patients with acute post traumatic dislocation. We do not recommend its use in younger patients (18 or under) especially with multidirectional instability. There is not enough evidence in our study to support the theoretical benefits of thermal capsular shrinkage.