[Disc replacement with the SB Charité endoposthesis - experience, preliminary results and comments after 35 prospectively performed operations]

Clinical outcomes of single-level lumbar artificial disc replacement compared with transforaminal lumbar interbody fusion in an Asian population

INTRODUCTION

The objective of this study was to examine the clinical outcome of single-level lumbar artificial disc replacement (ADR) compared to that of transforaminal lumbar interbody fusion (TLIF) for the treatment of symptomatic degenerative disc disease (DDD) in an Asian population.

METHODS

This was a retrospective review of 74 patients who had surgery performed for discogenic lower backs that involved only the L4/5 and L5/S1 levels. All the patients had lumbar DDD without radiculopathy or spondylolithesis, and concordant pain with discogram at the pathological level. The patients were divided into two groups--those who underwent ADR and those who underwent TLIF.

RESULTS

A trend suggesting that the ADR group had better perioperative outcomes (less blood loss, shorter operating time, shorter hospital stay and shorter time to ambulation) than the TLIF group was observed. However, a trend indicating that surgical-approach-related complications occurred more frequently in the ADR group than the TLIF group was also observed. The rate of revision surgery was comparable between the two groups.

CONCLUSION

Our findings suggest that for the treatment of discogenic lower back pain, lumbar ADR has better perioperative outcomes and a similar revision rate when compared with TLIF. However, the use of ADR was associated with a higher incidence of surgical-approach-related complications. More studies with bigger cohort sizes and longer follow-up periods are needed to determine the long-term efficacy and safety of ADR in lumbar DDD.

The future of spine surgery: New horizons in the treatment of spinal disorders

Background and Methods:

As with any evolving surgical discipline, it is difficult to predict the future of the practice and science of spine surgery. In the last decade, there have been dramatic developments in both the techniques as well as the tools employed in the delivery of better outcomes to patients undergoing such surgery. In this article, we explore four specific areas in spine surgery: namely the role of minimally invasive spine surgery; motion preservation; robotic-aided surgery and neuro-navigation; and the use of biological substances to reduce the number of traditional and revision spine surgeries.

Results:

Minimally invasive spine surgery has flourished in the last decade with an increasing amount of surgeries being performed for a wide variety of degenerative, traumatic, and neoplastic processes. Particular progress in the development of a direct lateral approach as well as improvement of tubular retractors has been achieved. Improvements in motion preservation techniques have led to a significant number of patients achieving arthroplasty where fusion was the only option previously. Important caveats to the indications for arthroplasty are discussed. Both robotics and neuro-navigation have become further refined as tools to assist in spine surgery and have been demonstrated to increase accuracy in spinal instrumentation placement. There has much debate and refinement in the use of biologically active agents to aid and augment function in spine surgery. Biological agents targeted to the intervertebral disc space could increase function and halt degeneration in this anatomical region.

Conclusions:

Great improvements have been achieved in developing better techniques and tools in spine surgery. It is envisaged that progress in the four focus areas discussed will lead to better outcomes and reduced burdens on the future of both our patients and the health care system.

The role of prosthesis design on segmental biomechanics: semi-constrained versus unconstrained prostheses and anterior versus posterior centre of rotation

The purpose of this study was to evaluate the influence of different implant designs of total lumbar disc replacements on the segmental biomechanics of the lumbar spine. The unconstrained Charité, the semi-constrained Prodisc and a semi-constrained Prototype with more posterior centre of rotation than the Prodisc were tested in vitro using six human, lumbar spines L2-L5. The segmental lordosis was measured on plain radiographs and the range of motion (ROM) for all six degrees of freedom with a previously described spine tester. All prostheses were implanted at level L3-L4. Compared with the intact status all prostheses resulted in a significant increase of segmental lordosis (intact 5.1°; Charité 10.6°, p = 0.028; Prodisc 9.5°, p = 0.027; Prototype 8.9°, p = 0.028), significant increase of flexion/extension (intact 6.4°, Charité 11.3°, Prodisc 12.2°, Prototype 12.2°) and axial rotation (intact 1.3°, Charité 5.4°, Prodisc 3.9°, Prototype 4.2°). Lateral bending increased significantly only for the Charité (intact 7.7°; Charité 11.6°, p = 0.028; Prodisc 9.6°, Prototype 9.8°). The segmental lordosis after Prototype implantation was significantly lower compared with Charité (p = 0.024) and Prodisc (p = 0.044). No significant difference could be observed for segmental lordosis between Charité and Prodisc and for ROM between the two semi-constrained prosthesis Prodisc and Prototype. The axial rotation for the unconstrained Charité was significantly higher than for the semi-constrained prosthesis Prodisc and Prototype, flexion/extension and lateral bending did not differ. Summarizing, the unconstrained prosthesis design increased segmental lordosis and showed a tendency towards higher ROM for axial rotation/lateral bending and lower ROM for flexion/extension than a semi-constrained prosthesis. A more anterior centre of rotation in a semi-constrained prosthesis resulted in a higher increase of segmental lordosis after TDR than a semi-constrained prosthesis with more posterior centre of rotation. The location of the centre of rotation in a semi-constrained prosthesis did not alter the magnitude of ROM. Despite the different alterations of ROM and segmental lordosis due to implant design, these differences were negligible compared with the overall increase of ROM and segmental lordosis by the implantation of a TDR compared with the physiologic state.

Resect or not to resect: the role of posterior longitudinal ligament in lumbar total disc replacement

With regard to the literature, several factors are considered to have an impact on postoperative mobility after lumbar total disc replacement (TDR). As TDR results in a distraction of the ligamentous structures, theoretically the postoperatively disc height and ligamentous integrity have also an influence on biomechanics of a treated segment. The purpose of the study was to evaluate the influence of posterior longitudinal ligament (PLL) resection and segmental distraction on range of motion (ROM). Six human, lumbar spines (L2-L3) were tested with pure moments of ±7.5 Nm in a spine loading apparatus. The ROM was determined in all three motion planes. Testing sequences included: (1) intact state, (2) 10 mm prosthesis (PLL intact), (3) 10 mm prosthesis (PLL resected), (4) 12 mm prosthesis (PLL resected). The prosthesis used was a prototype with a constrained design using the ball-and-socket principle. The implantation of the 10 mm prosthesis already increased the disc height significantly (intact: 9.9 mm; 10 mm prosthesis: 10.6 mm; 12 mm prosthesis: 12.7 mm). Compared to the intact status, the implantation of the 10 mm prosthesis resulted in an increase of ROM for flexion/extension (8.6° vs 10.8°; P = 0.245) and axial rotation (2.9° vs 4.5°; P = 0.028), whereas lateral bending decreased (9.0° vs 7.6°; P = 0.445). The resection of the PLL for the 10 mm prosthesis resulted in an increase of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 11.4°, P = 0.046; axial rotation: 5.1°, P = 0.046; lateral bending: 8.6°, P = 0.028). The subsequent implantation of a 12 mm prosthesis, with resected PLL, resulted in a significant decrease of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 8.4°, P = 0.028; axial rotation: 3.3°, P = 0.028; lateral bending: 5.1°, P = 0.028). Compared to the intact status, the 12 mm prosthesis with resected PLL only decreased lateral bending significantly while the 10 mm prosthesis with intact PLL increased axial rotation significantly. The resection of the PLL during TDR results in a significant increase of ROM in all three principle motion planes. But it still remains unclear if this increase which is in median not more than 1° may alter the clinical results. Moreover, the destabilizing effect of PLL resection can be reversed using a higher implant. The prosthesis height seems more crucial than PLL preservation to maintain the primary stability after TDR.

Design concepts in lumbar total disc arthroplasty

The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc prostheses. Both theoretical and experimental studies were analyzed, by a PUBMED search (performed in February 2007, revised in January 2008), focusing on single level TDA. Both semi-constrained and unconstrained lumbar discs seem to be able to restore nearly physiological IAR locations and ROM values. However, both increased and decreased ROM was stated in some papers, unrelated to the clinical outcome. Segmental lordosis alterations after TDA were reported in most cases, for both constrained and unconstrained disc prostheses. An increase in the load through the facet joints was documented, for both semi-constrained and unconstrained artificial discs, but with some contrasting results. Semi-constrained devices may be able to share a greater part of the load, thus protecting the surrounding biological structure from overloading and possible early degeneration, but may be more susceptible to wear. The next level of development will be the biomechanical integration of compression across the motion segment. All these findings need to be supported by long-term clinical outcome studies.

Degenerative changes of discs and facet joints in lumbar total disc replacement using ProDisc II: minimum two-year follow-up

STUDY DESIGN

A retrospective clinical and radiologic data analysis.

OBJECTIVE

To determine the radiologic changes in the discs at the adjacent levels and facets at the index and adjacent levels after total disc replacement (TDR) using ProDisc II in a minimum 2-year follow-up.

SUMMARY OF THE BACKGROUND DATA

The main purposes of TDR are to preserve the physiologic segmental motion at index level, and to prevent accelerated degeneration at the index and adjacent segments. However, there are few reports dealing with the effects of TDR on the degenerative changes in a long-term follow-up.

METHODS

After TDR using ProDisc II, the degree of disc and facets degeneration at the index and adjacent levels was assessed by observing lumbar magnetic resonance imaging (MRI) and computed tomography (CT) images before surgery and at minimum 26 months after operations. The degenerative changes of the discs and facets were determined in relation to the clinical outcome, various perioperative factors, and prosthesis factors.

RESULTS

Thirty-two patients with 41 TDR included in this investigation. The progression of facets degeneration (PFA) was observed in 12 of 41 TDR levels. Among 47 adjacent segments, the progression of disc degeneration and PFA were observed in 2 levels (4.3%), and 3 levels (6.4%), respectively. All cases of PFA occurred only in those with preoperative degeneration of grade 1. PFA at the index segments was positively related with female in gender (P = 0.008), the malposition of prosthesis on frontal plane (P = 0.025), and 2-level TDR in the number of TDR level (P = 0.008).

CONCLUSION

After TDR using ProDisc II, the degenerative changes in the discs and facets at the adjacent segments appeared to be minimal. However, in 29.3% of the TDR segments, the facet joints presented PFA, which was more common in female, malposition of prosthesis on frontal plane, and 2-level TDR in a minimum 2-year follow-up.

[Lumbar disc arthroplasty: indications, biomechanics, types, and radiological criteria]

Lumbar total disc replacement (TDR) was developed to treat a painful degenerative lumbar motion segment while avoiding the disadvantages of fusion surgery, such as adjacent segment instabilities. Early clinical results with TDR have shown a significant reduction in low back pain and a significant improvement in disability scores. When compared to fusion, the results with TDR tend to be superior in the short-term follow-up and initial rehabilitation is faster. The radiological assessment is an integral part of the preoperative work-up. Plain X-rays of the lumbar spine should be complemented by flexion - extension views in order to assess residual segmental mobility. Computed tomography is used to exclude osteoarthritis of the zygapophyseal joints, Baastrup's disease (kissing spines) and other sources of low back pain. Magnetic resonance imaging is useful to exclude substantial disc protrusions; it allows for the detection of disc dehydration and bone marrow edema in the case of activated spondylochondrosis. If osteoporosis is suspected, an osteodensitometry of the lumbar spine should be performed. Postoperative plain X-rays should include antero-posterior and lateral views as well as flexion - extension views in the later postoperative course. Measurements should determine the disc space height in the lateral view, the segmental and total lumbar lordosis as well as the segmental mobility in the flexion - extension views. The ideal position of a TDR is exactly central in the ap-view and close to the dorsal border of the vertebral endplates in the lateral view. Malpositioning may cause segmental hyperlordosis and unbalanced loading of the endplates with the risk of implant subsidence and migration.

Factors influencing segmental range of motion after lumbar total disc replacement using the ProDisc II prosthesis

Object.

The purpose of this prospective controlled study was to evaluate possible factors that could affect postoperative segmental range of motion (ROM) after lumbar total disc replacement (TDR) using the ProDisc II prosthesis.

Methods.

Thirty-two consecutive patients with intractable discogenic pain underwent lumbar TDR using the Pro-Disc II prosthesis, 30 of whom were followed up for at least 24 months. Segmental ROM was assessed preoperatively and every 6 months postoperatively using dynamic x-ray films. Segmental ROM at the reference level was assessed in relation to patient age, sex, body mass index (BMI), levels with implants, preoperative ROM, prosthesis size, and prosthesis position.

Results.

At the last follow-up visit, mean ROM of the disc prostheses was significantly increased from 4.23 ±3.12° to 6.81 ±3.76° at L3–4, and from 3.66 ±2.47° to 6.09 ±2.11° at L4–5. Mean ROM at L5–S1, however, was decreased from 3.12 ±1.56° to 2.86 ±1.26° (p > 0.05). This difference in the changes in postoperative ROM between L5–S1 and the other operated levels was the only statistically significant factor (p = 0.025) among the variables related to the postoperative ROM that the authors assessed, but other factors such as patient age, sex, BMI, disc height, and the size and position of the prosthesis were not related to segmental ROM.

Conclusions.

The data demonstrate that after TDR using the ProDisc II prosthesis, ROM of the prosthesis at L5–S1 is significantly lower compared with ROM at the other levels. In preserving ROM, the advantage of lumbar TDR using the ProDisc II might be minimal at L5–S1. Among the variables related to postoperative ROM, the level at which the ProDisc II prosthesis was implanted was the only one found to be statistically significant.

Lumbar total disc arthroplasty utilizing the ProDisc prosthesis in smokers versus nonsmokers: a prospective study with 2-year minimum follow-up

STUDY DESIGN

Prospective nonrandomized clinical series.

OBJECTIVES

To evaluate the efficacy of ProDisc lumbar artificial disc replacement (ADR) in smokers versus nonsmokers.

SUMMARY OF BACKGROUND DATA

Smoking is a negative predictor in fusion surgery. To date, a prospective study of the treatment of incapacitating discogenic low back pain using ADR in smokers versus nonsmokers has not been described.

METHODS

A prospective analysis was performed on 104 patients with disabling discogenic low back pain treated with single-level lumbar ProDisc total disc arthroplasty. Smokers and nonsmokers were assessed before surgery and after surgery using patient satisfaction, Oswestry, and Visual Analog Scores. Additionally, preoperative and postoperative neurologic, radiographic, and pain medication assessments were performed at similar postoperative intervals.

RESULTS

Oswestry, Visual Analog Scores, and patient satisfaction scores revealed statistical improvement beginning 3 months after surgery and were maintained at minimum 2-year follow-up. Patient satisfaction scores were higher in smokers (94%) than in nonsmokers (87%) at 2-year follow-up (P = 0.07). Radiographic analysis revealed an affected disc height increase from 4 mm to 13 mm (P < 0.05) and an affected disc motion from 3 degrees to 7 degrees (P < 0.05). No cases of loosening, dislodgment, mechanical failure, infection, or fusion of the affected segment occurred.

CONCLUSIONS

The results of our study indicate that smokers do equally well compared with nonsmokers when ProDisc ADR is used in the treatment of debilitating lumbar spondylosis. Patient outcome and radiographic scores showed significant improvement compared with preoperative levels. Although not evident in our series, additional surveillance for intraoperative and postoperative vascular spasm and occlusion may be warranted in smokers.

Charité total disc replacement--clinical and radiographical results after an average follow-up of 17 years

A retrospective clinical-radiological study to evaluate the long-term outcome after artificial disc replacement was performed. The objective is to investigate long-term results after implantation of a modular type artificial disc prosthesis in patients with degenerative disc disease (DDD). Total disc replacement (TDR) is a surgical procedure intended to save segmental spinal function, and thus replace spondylodesis. Short-term results are promising, whereas long-term results are scarce. The Charité TDR is the oldest existing implant, therefore, the longest possible follow-up is presented here. Seventy-one patients were treated with 84 Charité TDRs types I-III. Indication for TDR was moderate to severe DDD. Fifty-three patients (63 TDRs) were available for long-term follow-up of 17 years. Evaluation included Oswestry disability index, visual analog scale, overall outcome score, plain and extension/flexion radiographs. Implantation of Charité TDR resulted in a 60% rate of spontaneous ankylosis after 17 years. No significant difference between the three types of prostheses was found concerning clinical outcome. Reoperation was necessary in 11% of patients. Although no adjacent segment degeneration was observed in the functional implants (17%), these patients were significantly less satisfied than those with spontaneous ankylosis. TDR, nowadays, is an approved procedure. Proof that long-term results of TDR implantation in DDD are at least as good as fusion results is still missing.

The treatment of disabling multilevel lumbar discogenic low back pain with total disc arthroplasty utilizing the ProDisc prosthesis: a prospective study with 2-year minimum follow-up

STUDY DESIGN

Prospective, longitudinal minimum 2-year follow-up.

OBJECTIVE

To assess the efficacy and safety of the Prodisc implant in patients with disabling multilevel discogenic low back pain (LBP).

SUMMARY OF BACKGROUND DATA

Few, if any, alternatives have been proposed to treat recalcitrant and debilitating multilevel lumbar discogenic low back pain. To date, a prospective study specifically examining the use of multilevel Prodisc total disc arthroplasty has not been described.

METHODS

A prospective analysis was performed on 25 patients (63 prostheses) treated with multilevel lumbar ProDisc total disc arthroplasty. Minimum follow-up was 2 years. Patients 18 to 60 years of age with disabling discogenic low back pain and minimal radicular pain secondary to multiple level lumbar spondylosis from L1 to S1 were included. Preoperative and postoperative disability and pain scores were measured using Oswestry and visual analog scores. Preoperative and postoperative neurologic, radiographic, and pain medication assessments were also performed at similar postoperative intervals.

RESULTS

A total of 29 patients (72 prostheses) were enrolled in the prospective analysis. Twenty-five patients (63 prostheses) fulfilled all follow-up criteria and are included for final analysis. Fifteen bisegmental and 10 trisegmental level cases were performed. Visual analog pain, Oswestry, and patient satisfaction scores were significantly reduced at the 3-month as well as at 48-month follow-up. Radiographic analysis revealed an affected disc height increases from 5 mm to 12 mm (P < 0.05) and affected disc motions from 3 degrees to 7 degrees (P < 0.05). No change in adjacent level disc heights was seen. Complications included a single case of subsidence of the inferior endplate of the L4-L5 segment in a bisegmental L4-L5/L5-S1 case. We also report a delayed case of anterior extrusion of a polyethylene component in a patient who had sustained a fall of a bicycle.

CONCLUSIONS

Our preliminary data on multisegmental ProDisc lumbar total disc arthroplasty appear to be a safe and efficacious treatment method for debilitating lumbar spondylosis without significant facet arthropathy. In our select (non-Workers Compensation and/or medical legal) cohort of patients, we demonstrate a patient satisfaction rate of 93%. Careful and appropriate patient selection is essential in ensuring optimal surgical outcomes.

The treatment of disabling single-level lumbar discogenic low back pain with total disc arthroplasty utilizing the Prodisc prosthesis: a prospective study with 2-year minimum follow-up

STUDY DESIGN

Prospective, longitudinal minimum 2-year follow-up.

OBJECTIVE

To assess the efficacy and safety of the Prodisc implant in patients with disabling single-level discogenic low back pain (LBP).

SUMMARY OF BACKGROUND DATA

The treatment of debilitating discogenic LBP has been controversial and varied. To date, a longitudinal prospective study of the treatment of single-level incapacitating discogenic LBP using the Prodisc total disc arthroplasty technique has not been described.

METHODS

A prospective analysis was performed on 118 patients treated with single-level lumbar Prodisc total disc arthroplasty. Patients 18 to 60 years of age with disabling and recalcitrant discogenic LBP with or without radicular pain secondary to single-level discogenic LBP from L3 to S1 were included. Patients were assessed before surgery, and outcome measurements were after surgery administered at 3, 6, 12, and 24 months.

RESULTS

A total of 104 patients (88%) fulfilled all follow-up criteria. The median age of all patients was 47 years (range, 36-60 years). Statistical improvements in VAS, Oswestry, and patient satisfaction scores occurred 3 months postoperatively. These improvements were maintained at the 24-month follow-up. Radicular pain also decreased significantly. Full-time and part-time work rates increased from 10% to 35% and 3% to 24%, respectively. No additional fusion surgeries were necessary either at the affected or unaffected levels. Radiographic analysis revealed an affected disc height increase from 4 mm to 13 mm (P < 0.001) and an affected disc motion from 3 degrees to 7 degrees (P < 0.004).

CONCLUSIONS

Single-level Prodisc lumbar total disc arthroplasty is a safe and efficacious treatment method for debilitating lumbar discogenic LBP. Significant improvements in patient satisfaction and disability scores occurred after surgery by 3 months and were maintained at the 2-year follow-up. No device-related complications occurred. Patients with severe to moderate disc height loss as well as those with symptomatic posterior anular defects with minimal disc height loss achieve functional gains and significant pain relief. Careful and appropriate patient selection is essential in ensuring optimal surgical outcomes.

Reliability of motion measurements after total disc replacement: the spike and the fin method

As motion preservation is one of the main postulated advantages after total disc replacement (TDR) of the lumbar spine, the quantification of the mobility after TDR seems of special clinical interest. Yet, the best method to assess range of motion (ROM) after TDR remains unclear. The aim of the study was the calculation of 95%-confidence intervals (95%-C.I.) for the measurement error accompanying: (1) different methods (2) different observers and (3) different levels of training for radiographic motion analysis after TDR. In 12 patients the level L4-L5 and in another 12 patients level L5-S1 were measured with the Cobb and the superimposition method on flexion-extension X-rays after monosegmental TDR. Both methods were adopted as the landmarks used the spikes of the prosthesis instead the endplates (spike method) and the fin of the prosthesis instead the whole vertebral body (fin method). Measurements were performed by two experienced (O-I and O-III) and one inexperienced observer (O-II). The adopted spike and fin method showed a better reliability compared to the reported results of the original Cobb and superimposition method. The method used was not clinically relevant for the intraobserver reliability in the experienced observer (95%-C.I.: +/-2.0 degrees for the fin and +/-2.1 for the spike method) and for the interobserver reliability for two experienced observers (95%-C.I.: -2.8 degrees /+2.8 degrees for the fin and -2.9 degrees /+3.1 degrees for the spike method). The intraobserver reliability for the inexperienced observer was inferior for both methods compared to the experienced observer but no clinically relevant differences could be observed in interobserver reliability measures. The spike and fin method are reliable methods for study protocols dealing with angular motion after TDR as clinically valid conclusions can be drawn with an accuracy of about +/-2 degrees for the same observer and with an accuracy of about +/-3 degrees for a different observer.

The impact of total lumbar disc replacement on segmental and total lumbar lordosis

BACKGROUND

One of the goals of total lumbar disc replacement is restoration of the physiological sagittal alignment. There is little evidence if this goal is reached in vivo and further affects the clinical outcome.

METHODS

In 29 patients segmental lordosis and total lumbar lordosis were measured on X-rays pre- and postoperatively. The functional outcome was evaluated prospectively with the Visuell Analogue Scale, Oswestry Low Back Pain Disability Questionnaire and Short Form 36 Health Survey Questionnaire.

FINDINGS

Total disc replacement increased segmental lordosis significantly while total lumbar lordosis remained unchanged. Preoperative segmental/total lumbar lordosis was physiological in 52%/91% of the patients. Postoperatively these values changed to 72% for segmental- and 94% for total lumbar lordosis. No difference could be observed in clinical outcome measures in patients with physiological and unphysiological segmental lordosis.

INTERPRETATION

Monosegmental total disc replacement increases the segmental lordosis in most of the cases while preserving the total lumbar lordosis which produces a decrease of lordotic angle in the adjacent segment(s). Although short term clinical results are not affected, the segmental lordosis increase and adjacent segment(s) alteration may influence long term outcome.

Lumbar spine arthroplasty: early results using the ProDisc II: a prospective randomized trial of arthroplasty versus fusion

This study represents the first 39 patients with at least 6-month follow-up enrolled in a prospective randomized Food and Drug Administration study evaluating the safety and efficacy of the ProDisc II versus the control, a 360 degrees lumbar spinal fusion. Data were collected preoperatively and at 6 weeks, 3 months, and 6 months postoperatively. Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ), and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, and recreational and ambulatory status. There were 28 ProDisc patients and 11 who underwent fusion. Six patients had two-level surgery. Estimated blood loss (ProDisc = 69 mL versus fusion = 175 mL) and operative time (ProDisc = 75 minutes versus fusion = 219 minutes) were significantly different (P < 0.01). Hospital stays were shorter (ProDisc = 2.1 days versus fusion = 3.5 days [P < 0.01]) for ProDisc patients. There was a significantly greater reduction in the ODQ scores at 3 months in the ProDisc group compared with the fusion group (P < 0.05). No difference was noted in VAS. A trend was identified at 6 months in patient satisfaction rates favoring ProDisc versus fusion (P = 0.08), and motion was significantly improved in ProDisc patients compared with the fusion group (P = 0.02). Ambulatory status as well as recreational activity improved faster in the ProDisc group. The data suggest that total disc arthroplasty may be an attractive option as opposed to lumbar fusion for the surgical treatment of disabling mechanical low back pain secondary to lumbar disc disease.