Effectiveness of repeated radiofrequency neurotomy for cervical facet joint pain.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To determine the success rate and duration of relief of repeat radiofrequency neurotomy (RFN) for cervical facet joint pain. SUMMARY OF BACKGROUND DATA: RFN is an effective but temporary management of cervical facet pain. When pain recurs, RFN is usually repeated, but the outcomes for repeat RFN are not well established. METHODS: Record review of consecutive patients who had an initial successful RFN, recurrence of pain, and then one or more repeat RFN. Responses of repeat RFN were compared with initial RFN for success rates and duration of relief. Success was defined as >/=50% relief of targeted pain and patient sufficiently satisfied with prior RFN to have RFN repeated. RESULTS: There were 14 women and 8 men. Mean age was 47 years (range, 34 to 66 y). Sixty-four RFNs were performed. Mean duration of relief after initial RFN was 12.5 months (range, 3 to 25 mo). Forty-two RFNs were performed after the initial RFN. Forty-one of the 42 RFNs were available to follow-up (98%). Thirty-nine of the 41 RFNs were successful (95%). To date, 11 patients had a series of 2 RFNs performed, 7 had 3, 2 had 4, 1 had 6, and 1 had 7. Twenty-two patients had a second RFN, which was successful in 20 of the 21 available to follow-up (95%) but unsuccessful in 1 (5%). The mean duration of relief in these patients was 12.7 months (range, 3 to 30 mo) and the relief is continuing in 2 patients. Eleven patients had a third RFN, of which 10 (91%) were successful and 1 (9%) was unsuccessful. The mean duration of relief in 8 patients was 9.5 months (range, 3 to 16 mo), and the relief is continuing in the other 2. Four patients had a fourth RFN, which was successful in all 4. The mean duration of relief was 8.75 months (range, 4 to 12 mo). Two patients had a fifth RFN with both having a mean duration of relief of 9 months (11 and 7 mo, respectively). There were 2 patients with a sixth RFN, both were successful, 1 lasted 18 months and in the other relief is continuing. There was 1 patient with a successful seventh RFN, and relief is continuing. The frequency of success and durations of relief remained consistent after each subsequent RFN. CONCLUSIONS: In a carefully selected group of patients with cervical facet joint pain who have been responsive to previous RFN, repeat RFNs are usually successful.

Lumbar total disc arthroplasty in patients older than 60 years of age: a prospective study of the ProDisc prosthesis with 2-year minimum follow-up period.

OBJECT: The authors conducted a prospective longitudinal study to obtain outcome (minimum follow-up period 2 years) regarding the safety and efficacy of single-level lumbar disc (ProDisc prosthesis) replacement in patients 60 years of age or older. METHODS: This prospective analysis involved 22 patients treated in whom the lumbar ProDisc prosthesis was used for total disc arthroplasty. All patients presented with disabling discogenic low-back pain (LBP) with or without radicular pain. The involved segments ranged from L-2 to S-1. Patients in whom there was no evidence of radiographic circumferential spinal stenosis and with minimal or no facet joint degeneration were included. Patients were assessed preoperatively and outcome was evaluated postoperatively at 3, 6, 12, and 24 months by administration of standardized tests (the visual analog scale [VAS], Oswestry Disability Index [ODI], and patient satisfaction). Secondary parameters included analysis of pre- and postoperative radiographic results of disc height at the affected level, adjacent-level disc height and motion, and complications. Twenty-two (100%) fulfilled all follow-up criteria. The median age of all patients was 63 years (range 61-71 years). There were 17 single-level cases, four two-level cases, and one three-level case. Statistical improvements in VAS, ODI, and patient satisfaction scores were observed at 3 months postoperatively. These improvements were maintained at 24-month follow-up examination. Patient satisfaction rates were 94% at 24 months (compared with 95% reported in a previously reported ProDisc study). Radicular pain also decreased significantly. Patients in whom bone mineral density was decreased underwent same-session vertebroplasty following implantation of the ProDisc device(s). There were two cases involving neurological deterioration: unilateral foot drop and loss of proprioception and vibration in one patient and unilateral foot drop in another patient. Both deficits occurred in patients in whom there was evidence preoperatively of circumferential spinal stenosis. There were two cases of implant subsidence and no thromboembolic phenomena. CONCLUSIONS: Significant improvements in patient satisfaction and ODI scores were observed by 3 months postoperatively and these improvements were maintained at the 2-year follow-up examination. Although the authors' early results indicate that the use of ProDisc lumbar total disc arthroplasty in patients older than 60 years of age reduces chronic LBP and improves clinical functional outcomes, they recommend the judicious use of artificial disc replacement in this age group. Until further findings are reported, the authors cautiously recommend the use of artificial disc replacement in the treatment of chronic discogenic LBP in patients older than age 60 years in whom bone quality is adequate in the absence of circumferential spinal stenosis.

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.

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.

An extrapedicular approach to the placement of screws in the thoracic spine: an anatomic and radiographic assessment.

STUDY DESIGN: A radiographic and anatomic study of an extrapedicular method of screw placement in cadaveric thoracic spines. OBJECTIVE: To evaluate an alternative method of thoracic vertebral body screw fixation using an extrapedicular screw technique. To evaluate the anatomic safe zones and proper starting point for this alternative approach to the placement of screw fixation in the thoracic spine. SUMMARY OF BACKGROUND DATA: Despite the clinical successes reported with thoracic pedicle screw-rod constructs, controversy exists about the safety of this technique in pedicles that are anatomically too small for transpedicular fixation. An alternative method of extrapedicular screw fixation was evaluated in this present study. MATERIALS AND METHODS: Two fresh, unfixed, adult cadavers were obtained randomly; 6.0-mm AO Synthes pedicle screws were placed using an extrapedicular approach bilaterally from T3 to T10. The screws were placed according to one defined method described later. Computerized tomographic (CT) images were obtained. The position of each screw was analyzed. The cadavers were then dissected with the screw pathway exposed and the relation of the screw to surrounding anatomy documented. RESULTS: All screws did not penetrate the spinal canal. All screws were within the pedicle rib unit and did not penetrate the neural foramen or pleura. CONCLUSION: This study, although only introductory, indicates the potential for extrapedicular vertebral body fixation in the thoracic spine. Biomechanical evaluations are presently being conducted to evaluate the use of extrapedicular thoracic screw fixation.

Morphometric comparison of the pedicle rib unit to pedicles in the thoracic spine.

STUDY DESIGN: A radiographic study of the pedicle rib unit morphology as compared with measurements of the pedicle in cadaveric thoracic spines. OBJECTIVE: To evaluate the morphology of pedicle rib units in the thoracic spine in normal thoracic human spines, with particular attention to T4-T9, and to compare the dimensions of the pedicle rib unit with corresponding dimensions of the adjacent pedicles. SUMMARY OF BACKGROUND DATA: Despite the clinical successes reported with thoracic pedicle screw-rod constructs, controversy exists as to the safety of this technique in pedicles that are anatomically too small for transpedicular fixation. An alternative method of extrapedicular screw fixation within the pedicle rib unit was evaluated in a previous study and found to be anatomically feasible. Although the morphology of the pedicle rib unit was described in two previous studies, the measurements were obtained in scoliotic spines. Therefore, no study has sought to define the transverse dimension and chord length of the pedicle rib unit, and compare it with the corresponding pedicle dimensions. MATERIAL AND METHODS: Six fresh unfixed adult cadavers were obtained randomly. No history of spine disease was noted, and cause of death was unrelated to spinal disorder or trauma. The mean age was 84, with a range of 76 to 90. There were two females and four males. Computerized tomographic (CT) images of the thoracic spine were obtained. For cadavers in which the gantry resulted in oblique axial sections, reformatting was performed for more accurate measurements. Measurements of the transverse diameter and chord length of the pedicle rib unit were obtained and compared with measurements of the transverse pedicle width and chord length. RESULTS: The transverse width and chord length of the pedicle rib unit were significantly larger than corresponding pedicle measurements at all levels, a consistent finding when comparing the mean of all levels, the mean of T4-T9, and the mean of each individual level T4-T7. CONCLUSION: This study confirms the marked difference in size of the pedicle rib unit as compared with the pediclein both transverse width and chord length. This allows for a space that accommodates much larger major screw diameters, longer screw lengths, and because of the nature of screw placement, a greater screw convergence. Thus, there is anatomic potential for extrapedicular vertebral body fixation in the thoracic spine. However, care must be taken in placement of screws following precisely our previously described method of extrapedicular screw insertion. Penetration of surrounding structures, most notably the aorta on the left, is a potential risk when deviating from the method. Biomechanical evaluations are presently being conducted to evaluate the use of extrapedicular thoracic screw fixation.