Adjacent segment degeneration following ProDisc-C total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF): does surgeon bias effect radiographic interpretation?

PURPOSE: Many investigators have reported the financial conflicts of interest (COI), which could result in potential bias in the reporting of outcomes for patients undergoing total disc replacement (TDR) rather than anterior cervical discectomy and fusion (ACDF). This bias may be subconsciously introduced by the investigator in a non-blinded radiographic review. The purpose of this study was to determine if bias was present when a group of spine specialists rated adjacent segment degeneration (ASD) following cervical TDR or ACDF. METHODS: Potential bias in the assessment of ASD was evaluated through the reviews of cervical radiographs (pre- and 6 years post-operative) from patients participating in the ProDisc-C FDA trial (ProDisc-C IDE #G030059). The index level was blinded on all radiographs during the first review, but unblinded in the second. Five reviewers (a radiologist, two non-TDR surgeons, and two TDR surgeons), two of whom had a COI with the ProDisc-C trial sponsor, assessed ASD on a three point scale: yes, no, or unable to assess. Intra- and inter-rater reliabilities between all raters were assessed by the Kappa statistic. RESULTS: The intra-rater reliability between reviews was substantial, indicating little to no bias in assessing ASD development/progression. The Kappa statistics were 0.580 and 0.644 for the TDR surgeons (p < 0.0001), 0.718 and 0.572 for the non-TDR surgeons (p < 0.0001), and 0.642 for the radiologist (p < 0.0001). Inter-rater reliability for the blinded review ranged from 0.316 to 0.607 (p < 0.0001) and from 0.221 to 0.644 (p < 0.0001) for the unblinded review. CONCLUSIONS: The knowledge of the surgical procedure performed did not bias the assessment of ASD.

Mimickers of lumbar radiculopathy.

Orthopaedic surgeons frequently treat patients who report pain that radiates from the back into the lower extremity. Although the most common etiology is either a herniated disk or spinal stenosis, a myriad of pathologies can mimic the symptoms of radiculopathy, resulting in differences in the clinical presentation and the workup. Therefore, the clinician must be able to distinguish the signs and symptoms of lumbar radiculopathy from pathologies that may have a similar presentation. Being cognizant of these other possible conditions enables the physician to consider a breadth of alternative diagnoses when a patient presents with radiating lower extremity pain.

Cervical spinal cord contusion in professional athletes: a case series with implications for return to play.

STUDY DESIGN: Retrospective case series. OBJECTIVE: This report provides long-term follow-up on athletes who have sustained a cervical spinal cord contusion. Their magnetic resonance (MR) image is correlated with clinical signs and symptoms. Mechanism of injury and a hypothesis of etiology are reported. SUMMARY OF BACKGROUND DATA: Current return-to-play criteria for athletes who sustain a cervical cord contusion are based on expert opinion only. Decision making for this clinical situation in athletes carries significant clinical, legal, and economic ramifications. The natural history, clinical correlation, and effect of surgery for athletic cervical cord contusions have not been established. The mechanism of injury for this entity has historically emphasized axial loading. METHODS: The case histories, physical examination, and MR images were reviewed for 4 professional athletes. All athletes had documented cervical cord contusions. None of the athletes had an acute disc herniation, fracture, instability, or focal cord compression. All athletes were contacted by telephone to assess symptoms at a minimum follow-up of 2 years after injury. RESULTS: All 4 athletes had congenital stenosis, defined as lack of CSF signal around the cord on an MR image. All underwent anterior fusions at the level of their contusion. In follow-up, 2 athletes developed new contusions: one more than 5 years later, adjacent to a fusion; and 1, 2 years later, not adjacent to his previous fusion. No athlete developed permanent neurological sequelae. The presence of a contusion did not correlate with athletes' signs and symptoms. The mechanism of injury was hyperextension. CONCLUSION: It is hypothesized that the horizontal facet orientation of the C3-C4 level, congenital stenosis, and relative hypermobility in extension are the contributing factors in the cause of this clinical entity. An anterior fusion at the C3-C4 level seems to be the most reliable method of preventing or delaying the return of symptoms. Return-to-play guidelines should emphasize the athletes' history of symptoms in context with their MR image because there is poor correlation between the finding of a contusion and the clinical presentation. Recurrence of symptoms is common and the long-term consequences of repeated episodes remain unknown.

Transpedicular decompression and pedicle subtraction osteotomy (eggshell procedure): a retrospective review of 59 patients.

STUDY DESIGN: Outcomes of transpedicular decompression and/or osteotomy were analyzed retrospectively. OBJECTIVES: To determine the effectiveness of decompression and correction, fusion stability, procedural safety, neurologic outcome, complication rates, and overall patient outcomes. SUMMARY OF BACKGROUND INFORMATION: The "eggshell" procedure is reserved for complex reconstructive problems in the treatment of acute trauma, deformity, tumor, or infection. The technique encompasses a range of procedures from simple transpedicular decompression and posterior fusion to more complex procedures, including transpedicular vertebrectomy and strut-grafting or pedicle subtraction (closing wedge) osteotomy with posterolateral fusion. These procedures are completed through a single posterior midline incision, with anterior spinal canal decompression a transpedicular approach, accompanied by a posterior or posterolateral fusion and internal fixation. METHODS: From 1990 to 1998, 59 "eggshell" procedures were performed for 37 deformity cases and 22 tumor or infection cases. Forty-two patients had a minimum 2-year follow-up, averaging 4.5 +/- 2.5 years. Thirty-six patients were available for patient interview, physical examination, and radiographic analysis. Outcome data were collected using SF-36 and SRS instruments. RESULTS: No patients worsened neurologically, and all incomplete spinal cord injuries improved. All patients achieved solid fusion radiographically. Correction with osteotomy averaged 26 degrees. Systemic complication rates were low with a pulmonary complication rate of 5%. Blood loss averaged 2342 mL. Overall patient outcomes were below population norms, but patient satisfaction was very high. CONCLUSION: Overall, the results suggest that the "eggshell" procedure is a reliable and safe technique to achieve anterior decompression of the spinal canal and posterior stabilization through a single approach.