Abstract

INTRODUCTION:

Stationary fluoroscopy has been a viable resource for determining in vivo knee kinematics, but limitations have restricted the use of this technology. Patients can only perform certain normal daily living activities while using stationary fluoroscopy and must conduct the activities at speeds that are slower than normal to avoid ghosting of the images. More recently, a Mobile Tracking Fluoroscopic (MTF) unit has been developed that can track patients in real-time as he/she performs various activities at normal speeds (Figure 1). Therefore, the objective of this study was to compare in vivo kinematics for patient's evaluated using stationary and mobile fluoroscopy to determine potential advantages and disadvantages for use of these technologies.

Introduction

The majority of spine patients present with discogenic low back pain, originating from either degenerative disc disease (DDD) or internal disc disruption (IDD). Successful treatment of this patient population relies on obtaining precision diagnosis and careful patient selection, as well as matching the pathology with reliable technology. Total disc replacement (TDR), as an alternative to spinal fusion in the treatment of DDD or IDD, has been studied and reported for several decades in long-term follow-up studies and in several randomized control trials. This prospective study presents a single surgeon experience with two-level CHARITÉ® TDR in 84 consecutive patients, with minimum follow-up of 5 years. The aims of the study were to assess the clinical outcomes of two-level TDR in patients with DDD/IDD. Based on the literature review conducted, this study is considered the largest single surgeon series experience with the two-level CHARITÉ® TDR in the treatment of lumbar DDD, with a minimum follow-up of 5 years reported to date.

Introduction This is a prospective, consecutive series of 178 prosthetic implantations to analyse single level versus multiple level cervical arthroplasty with two years minimum follow-up

Methods Fifty-five patients underwent a total of fifty-five Porous Coated Motion (PCM) cervical arthroplasties from C3–4 to C7–T1 (Group S for single level). Fifty-four patients underwent one hundred and nine multilevel PCM cervical arthroplasties (Group M for multilevel) during the same time interval, for the same indications, performed by the same surgeons under the same clinical protocol— double level, 43 cases; three levels, 7 cases: and four levels, 4 cases. Sixteen PCM cases had been performed as complex revision procedures with prior fusions—9 in Group S and 7 in Group M. They included 1 previous Bryan Disc, 1 cage-plate, 1 patient with Klippel-Feil disease, 3 patients had failed lordotic cervical cages. One additional patient in Group M had a fracture-dislocation at C4–5 with a pseudarthrosis at C3–4 and C5–6. The demographics between Group S and Group M were very similar—mean age of patients, gender, severity of neurologic symptoms and distribution of radicular and myeloradicular symptoms.

Results There were no deaths, no infections, and no instances of iatrogenic neurologic progression in either the single level or the multiple level arthroplasty group. The mean EBL, length of surgery, and length of hospital stay were greater for the Multilevel Group. In contrast to these three operative demographic statistics, the self assessment outcomes instruments consistently showed more improvement for the multilevel cases. The mean improvement in the NDI for the single cases was 54.8 % (+/− 20.9) versus the multilevel cases mean improvement in NDI was 64.8 % (+/− 33.7). The mean improvement in the VAS showed the same relationship—single level mean improvement 62.0 % (26.9) versus the multilevel cases mean VAS improvement was 68.1% (+/− 31.4). The SF-36, Odoms, and TIGT were also more improved for the multilevel versus the single level group. The reoperation rates, adverse events, and incidence of complications were the same between the single level to the multilevel arthroplasty groups.

Discussion This prospective report of cervical arthroplasty demonstrates that each cervical vertebral level is biomechanically independent of the adjacent level, whether it contains an arthoplasty or an unoperated intervertebral disc. With the Porous Coated Motion cervical arthroplasty the incidence of reoperation did not increase proportionately higher as the number of cervical levels requiring instrumentation increased. Even in three and four level arthroplasty the true benefits of cervical disk replacement outcomes were demonstrated on functional clinical outcomes at minimum two-year follow-up

Introduction Adjacent segment disease with radiculopathy and neurologic deficit adjacent to a non-mobile spinal segment is the ideal application for cervical arthroplasty. Not only are the stresses and loads increased but unfortunately the previously fused segment is further compromised by being fixed in a kyphotic position.

Methods This is a prospective study of 40 PCM prostheses inserted in thirty patients with 50 adjacent segments previously fused or rendered immobile—ten cases were performed as bi-level implantations. The inclusion and exclusion criteria were otherwise identical to the normal FDA prospective IDE criteria with all patients presenting with radiculopathy and a corresponding neurologic deficit confirmed by an MRI compressive lesion.

Results The mean preoperative cervical lordosis was 2.65 degrees (−32 to 25), mean postoperative lordosis 12.3 degrees (−17 to 30), and the mean improvement was 9.4 degrees of cervical lordosis (range (−15 to 23). EBL = 0 to 100 cc with no patients requiring blood transfusions, Length of surgery = mean 104 minutes (60 to 150) and the length of hospital stay = mean 1.17 days (0 to 3 days). The clinical follow-up was greater than 2 years. All patients were neurologically intact at follow up with a mean improvement of NDI = 50 % and mean improvement in VAS = 58.3 %.The range of flexion and extension motion at the level of the prosthesis was a mean of 8.9 degrees (range 4 to 20 degrees).

Discussion Naturally, the adjacent segment application of a cervical disc replacement is a challenging clinical environment for cervical arthroplasty – by definition every case had prior surgery. Not only is the cervical spine position often compromised by being in excessive kyphosis, but seventeen of the 50 previously fused levels had prior cervical instrumentation. 5 patients had previous cervical cages, 2 had cage-plates, 5 patients had previous anterior cervical plates, one had a prior arthroplasty device with HO, and 4 patients had PMMA which required revision. Despite the complicated nature of the presenting pathology, the Porous Coated Motion Cervical prosthesis successfully restored some element of cervical lordosis, and restored stability to the cervical segments. An added potential bonus is the preserved 9.4 degrees of flexion – extension mobility. The PCM appeared to work well in these revision cases. This is the world’s largest study to date investigating prospectively the value of cervical arthroplasty in adjacent segment disease.

Introduction Historically, lumbar discography has been one of the most controversial subjects in the management of discogenic low back pain. The diagnostic value of normal psychometric specific pain provocation by disc pressurization has emerged. The sensitivity, specificity and accuracy of discography as a diagnostic test are not in doubt. In clinical discography pain reproduction and location are essential elements. There is an accepted rate of 0–10% false positives. This rate is influenced by occupational disability and abnormal psychometric profiles. By contrast, little attention has been given to false negative results and their outcomes if surgically treated. Traditionally, whether or not the test is considered to be positive or negative is determined immediately after completion of the diagnostic procedure. This study shows that patient’s pain reproduction may occur up to 24 hours after the discogram which often initially interpreted as a true negative when it is actually a false negative result. This study verifies the existence and significance of a false negative through the patients’ treatment and outcomes.

Methods In this study, 150 patients underwent discography for investigation of chronic persistent low back pain (CPLBP). All patients had a control (morphologically normal) discogram at the level above the degenerative segment. No patients with abnormal psychometric profiles or compensation were included. All patients were followed up 24 hours post discogram by the radiologist to further assess their clinical status. Ten of the patients (7.5%) were considered to have a false negative discogram, as per the Dallas Discogram Scale. The surgeon correlated the delayed response on the subsequent follow-up. These ten patients were diagnosed as having a positive response and were treated surgically for their discogenic pain. VAS-B, VAS-L, ODI, RMD were collected prospectively. Preoperative and 6 month results were reviewed.

Results Seven of the 10 patients (70%) reported severe increase CPLBP and reproduction of pain within 8 hours of the discogram, while 3 patients (30%) did so in the ensuing 24 hours after the discogram. Surgical treatment was either by total disc replacement or anterior lumbar interbody fusion. All patients reported greater than 50% reduction in VAS-B and VAS-L and with improvements of greater than 50% in their ODI and RMD scores.

Discussion The clinical reliability of discography hinges on the subjective assessment of pain concordance as the discriminating factor in determining false positives from false negatives. Given the limitations of discography, all information about the patient should be considered prior to diagnosis, including clinical, radiological, historical, and psychometric factors. The delayed positive discography response is an important consideration for the patient, the radiologist, and the treating surgeon to be aware of. The results of this study verify the existence of this subgroup and justify their surgical treatment.

Introduction Surgical management of low back pain secondary to multilevel degenerative disc disease and internal disc disruption (DDD/IDD) remains controversial. There is little published evidence as to the success of multilevel total disc replacement (TDR). The purpose of this study is to assess two-level TDR as a treatment option for multilevel DDD/IDD, report the postoperative return to work rate, and assess the results of compensation patients and patients with prior surgery.

Methods This is a retrospective review of 79 patients with multilevel DDD/IDD who received two-level TDR with the Charité artificial disc prosthesis. One patient declined study entry. The average follow-up was 29 months (12–72). In 69 cases L4-5/L5-S1 TDR was pre-formed, in 8 cases L3-4/L4-5, and in 1 case L3-4/L5-S1. Seven patients received a fusion at an adjacent level. The outcome measures used were back and leg Visual Analogue Score (VAS), Oswestry Disability Index (ODI), and Roland-Morris Disability Questionnaire (R-MD). Data were collected preoperatively and postoperatively at 3, 6, 12, and 24 months, and annually thereafter. All patients completed preoperative and end-point outcome measures; although some of the postoperative outcome data was incomplete. Patient compensation status and postoperative return to work was documented.

Results When comparing preoperative and end-point assessments, there was a 77.9% improvement in back VAS, an 85.7% improvement in leg VAS, a 35 point (68.1%) improvement in ODI, and a 12.4 point (71.9%) improvement in R-MD. As some postoperative outcome measures were not completed, subgroups with complete data were analysed. Fifty patients completed a 12-month assessment. There was a 79.7% improvement in back VAS, an 89.7% in leg VAS, a 36.0 point (70.4%) reduction in ODI, and an 11.8% (74.7%) reduction in R-MD. Thirty-four patients completed the 24-month data. There was an 80.6% improvement in back VAS, a 91.6% in leg VAS, a 43.1 point (78.0%) reduction in ODI, and a 13.6 (77.5%) reduction in R-MD.

Nine patients had undergone prior surgery. When compared with those with no prior surgery, no statistical difference was detected. There was a trend for the ODI and back VAS scores of the patients with previous surgery improved more quickly in the early stages. Fourteen patients were involved in compensation claims at the time of surgery. Their results were compared with those patients without compensation claims. The numbers were too small to be statistically significant, but there was a trend suggesting recovery was delayed in the compensation group. However, at 24 months there was no difference in the outcome scores. In the patient sample, 87% of patients returned to work. No major intra-operative complications were documented. One neurological complication was documented. Two revision procedures were preformed. No prosthetic failure occurred.

Discussion TDR in the lumbar spine for treatment of multilevel DDD/IDD is a viable option and will become part of the armamentarium of spine surgeons and possibly the treatment of choice. The postoperative improvements in outcome measures are significant and sustained. Prior surgery and compensation does not preclude a good result.

Introduction and Aims: Fibular hemimelia presents a problem with leg length discrepancy and equinovalgus foot deformity. Our protocol is to simultaneously treat both problems, with the goals of equalising limb length and achieving a plantigrade painless functional foot.

Method: Seventy-eight patients with fibular hemimelia underwent 92 lengthenings and foot deformity correction. Equinovalgus foot deformity was corrected by four different methods in 67 cases: distraction, soft tissue release, release plus supramalleolar and/or subtalar osteotomy, and fibular transport.

Results: Goals of lengthening and foot deformity correction were achieved in all cases. Foot deformity recurred in 19 patients and was retreated: 9/16 (56%) distraction cases, 4/18 (22%) soft tissue release cases, 2/28 (7%) release plus osteotomy cases, and 4/5 (80%) fibular transport cases. Genu valgum developed in many cases with no or partial anlage resection. Genu valgum did not develop in any cases with complete anlage resection. Final results based on functional and radiographic evaluation: 46 excellent, 28 good, 18 fair. Final result did not correlate with number of rays in foot.

Conclusion: Limb length discrepancy and foot deformity can be successfully treated by simultaneous lengthening and foot deformity correction. Soft tissue release plus osteotomy and complete anlage resection yielded best results. Lengthening reconstruction surgery is an excellent alternative to ablative surgery and prosthetic fitting for patients with all severities of fibular hemimelia.

Introduction: Prosthetic devices have been developed to partially or totally replace symptomatic discs. Potential postoperative complications include infection, mechanical failure, loss of fixation, and neurological irritation or deficit. In the event of a complication, a sound surgical salvage strategy can result in a satisfactory outcome for the patient.

Methods: The study is a retrospective review of five revision cases in patients implanted with the third-generation Charité artificial disc prosthesis. The study involves a series of 182 patients since 1997, performed by a single surgeon. Of the 182 cases, 5 (2.7%) required surgical revision. The outcome measures used included back and leg VAS, Oswestry Disability Index (ODI), Roland-Morris Disability Questionnaire (R-MD), and patient self-assessment of outcome.

Results: Patient #1 had total disc replacement (TDR) at L3-4 and L4-5 and developed an early anterior sub-luxation at L3-4. The original device was removed and a new prosthesis inserted. Patient #2 had TDR at L4-5 and L5-S1 and experienced a core dislocation at L5-S1 resulting in a left iliac vein obstruction. This patient had an inferior vena cava umbrella with removal of the prosthesis and conversion to ALIF. Patient #3 had TDR at L4-5 and L5-S1 and experienced increased L5 radicular pain due to over distraction at L5-S1. This patient underwent removal of the prosthesis and conversion to instrumented circumferential fusion. Patient #4 had TDR at L5-S1 and experienced a core dislocation. The prosthesis was removed and an ALIF was performed. Patient #5 had TDR at L5-S1 and developed a spondylolisthesis secondary to progression of facet arthropathy. The prosthesis remained in situ and was supplemented with an instrumented posterolateral fusion. Mean back VAS was 4.2 (0–7). Mean leg VAS was 2.1 (0–7). Mean ODI was 32.4 (0–58). Mean R-MD was 11.4 (1–18). Patients were asked to rate their satisfaction with their revision outcome with choices of excellent, good, satisfactory, or poor. Four rated their outcome as excellent and one as good. Two patients suffer from the significant co-morbidity of rheumatoid arthritis and one is in early postoperative phase.

Discussion: Considerable scepticism exists about the advantages of total disc replacement and significant attention has been given to revision procedures and complications. A surgical revision rate of 2.7% from a single surgeon’s experience was reported. This rate is well below the rate suggested in the literature in relation to lumbar fusion. Careful patient selection and pre-operative planning remain paramount in avoiding the need for revision. As with other types of spinal surgery, a reliable and predictable surgical revision strategy is necessary to manage complications.

Introduction: The treatment with epidural steroids and local anaesthetic for radicular pain arising from nerve root compression is a commonly utilised and recognised treatment. The aim of this study is to determine the efficacy of CT-guided injection of epidural steroids without anaesthetic for radicular pain but without clinical neurology in the presence of a degenerative of lytic spondylolisthesis and concomitant foraminal narrowing.

Method: The study subjects, 21 in total, were selected over a 1-year period by the surgeon. All patients had either degenerative or lytic spondylolisthesis as determined by CT, MRI and plain film and were suffering from radicular pain – sharp, shooting and burning in the L5 or S1 dermatome. For inclusion, there had to be no associated evidence of nerve root compression. All patients completed, prior to epidural therapy, a pain diagram, visual analogue scale (VAS) of pain severity on a scale of 1 to 10 and Oswestry Disability Index (ODI). The MRI and clinical pain picture were correlated. The level of the spondylolithesis was determined.

Highly selective CT-guided epidural steroid injection was then carried out at the level of spondylolithesis by an experienced interventional radiologist. The pain diagram, VAS of pain severity and ODI were all completed again by the subjects themselves or by telephone at 1 and 3 months after injection in the presence of an independent assessor (nurse) and then reviewed and discussed with the treating doctor. All subjects were also asked to complete a functional questionnaire.

Results: One month after injection 86% of those treated had greater than 50% radicular pain relief and from this group 72% had radicular pain reduction of greater than 80%. All had improvement in function. All of the above, confirmed that their quality of life had certainly improved. Three months after injection 76% of those treated still had a reduction in their radicular pain of greater than 50% (92% of these still had pain reduction of over 80%). Again all reported continued functional improvement.

Discussion: Despite the small sample size, this study highlights the short-term Benefit of CT-guided steroid epidural injections with symptomatic lumbosacral spondylolisthesis and spondylolysis with radicular pain. Pain can be relieved without anaesthesia. The mechanisms of pain relief are speculative.

Introduction: This is a prospective study to determine the effectiveness of artificial disc replacements in the treatment of discogenic low back pain. There has been increasing interest in the possibility of preserving the motion of a diseased vertebral motion segment by various biomechanical designs. Preserving the motion of the segment, rather than opting for arthrodesis seems intuitively to be a more favourable treatment for several spine disorders.

Up until now most spine surgery has been salvage (correcting the effects of trauma, stabilising correcting deformity, fusing degenerative segments) not restoration of normal function. As new alternatives to fusion come to fruition, we now have the ability to truly restore the spine to normal function. Spinal arthroplasty is a new concept and includes total disc replacement, nuclear replacement and there are efforts by investigators looking at posterior element reconstruction or facet replacement.

Methods: The data have been collected from the surgical experience of one surgeon since commencement of this procedure in 1996. Data were collected from pre-operative, post-operative clinical and patient questionnaires (both pre- and post-operative) and radiological assessment.Patient questionnaires include Roland-Morris Questionnaire, Oswestry Questionnaire, Visual Analogue Scores, and SF36 Data.

Results: 86 Patients have had implantation of the Charite artificial disc prosthesis “Link”; 113 levels have been instrumented; 42 males, 44 females; follow-up two months to five years, average follow-up 20 months.

The results so far indicate good to excellent in 84% of cases. Complications have the potential to be catastrophic but attention to surgical detail results in minimal complications which will be discussed in the body of the presentation.

Discussion: This paper is a prospective study. It also represents a personal surgical evolution and understanding of the role disc replacement plays in the treatment of discogenic low back pain. Disc replacement should be used as part of the armamentarium a spine surgeon can utilise in his practice. There are strict guidelines and criteria that need to be adhered to if optimal results are to be obtained. The artificial disc which has been most extensively used in the world is the Link SB Intervertebral Prosthesis. To date, over 2000 cases have been performed worldwide. The study is not intended to suggest that routine or indiscriminate use of the artificial disc replacement is warranted, but rather serves to provide a framework for further investigation to the utility of spinal arthroplasty with function intervertebral replacements.

Introduction: Anterior cervical discectomy and inter-body fusion (ACDF) is recognised as an effective surgical treatment for cervical degenerative disc disease. The goals of anterior discectomy, interbody graft placement, and subsequent fusion, are to improve and maintain intervertebral height, establish and maintain physiological cervical lordosis, and achieve arthrodesis so as to eliminate pathological motion. Establishing the most clinically effective and cost effective operative approach to achieve these goals while, at the same time, minimising post-operative complications, is currently an evolving process. One view is that the use of anterior cervical plates reduces graft-related complications, maintains the cervical alignment, and leads to a higher incidence of fusion. In addition, there is evidence to suggest that there is a direct cost benefit of earlier return to pre-operative function and employment.

Bone graft: Iliac crest autograft would be regarded as the gold standard source of bone for ACDF. However, donor site complications (due to harvesting autograft) are not insignificant and range from 1% to a sizeable 29%. These complications include iliac crest fracture, infection, persisting pain, neural injury, bowel injury, etc. With the advent of bone banks, allograft has become available and eliminates the problem of graft-harvest related complications. There is a theoretical risk of disease transmission and a corresponding difficulty with patients accepting donated tissue. To date, no HIV cases transmission has occurred from ACDF allograft. There are several studies that demonstrate a significant difference in fusion rates when comparing allograft and autograft. The preponderance of data from the literature supports the conclusion that the use of allograft in ACDF can lead to a higher incidence of graft collapse, pseudarthrosis, and possible subsequent revision surgery. Bishop et al., (Spine 1991 16:726–9): have documented a higher increase in pseudarthrosis rate, graft collapse, and interspace angulation in the allograft group compared to the autograft group. Therefore, the dilemma of allograft being preferred as a basis of eliminating graft harvesting complications, while at the same time being associated with a higher incidence of fusion failure and deformity, have led some surgeons to trial the combination of allograft with anterior plate fixation. Shapiro (J Neurosurg 1966 84:161–5) has reported no incidences of fusion failure, graft collapse, progressive kyphosis, or plate-related complications in 82 consecutive single and multiple level ACDF’s using allograft and anterior plating.

Treatment failure: The incidence of the following complications have been reported in the literature. (Graham JJ. Spine 1989 14:1046–50).

Pseudarthrosis – 3%–36%

These figures are regardless of the graft source and are significant. Recent studies show that the combination of graft and anterior plate fixation virtually eliminates the complication of graft extrusion, and also decreases the risk of graft collapse and development of pseudarthrosis. There are also studies that contend that plate fixation can maintain proper lordotic alignment of the spine more effectively than can ACDF without plating. I contend that the use of contemporary cervical plates significantly decreases the rate of fusion failure and graft-related complications without imparting significant implant-related complications.

As a result, there is decreased overall risk to the patient.

The current type of plates which are available are unicortical with locking systems that substantially decrease the risk of screw loosening or hardware migration.