High Rate of Revision Surgery After Limited Decompression of Lumbar Facet Cysts.

INTRODUCTION: The surgical treatment of lumbar facet cysts has long been debated. Some surgeons elect for limited decompression of such cysts while other surgeons elect for primary decompression and fusion over concerns for recurrence and instability. Previous studies have suggested the rate of revision surgery after facet cyst excision to be as low as 1%, whereas others have reported this rate to be markedly higher. In this study, we examined revision surgery rates and patient-reported outcomes and conducted a radiographic analysis to identify predictors of failure after limited decompression of lumbar facet cysts. METHODS: A retrospective review of the electronic medical records of patients treated at our institution using the Current Procedural Terminology code 63267 before January 2018 was conducted. The primary outcome measure was revision surgery at the index level for recurrence or instability or a minimum 2-year follow-up without revision surgery. Secondary outcome measures include radiographic assessments of preoperative and postoperative spondylolisthesis and patient-reported outcome measures. Using preoperative MRI studies, an analysis of facet angles at the surgical level was conducted and the presence, location, and amount of facet fluid were calculated. RESULTS: A total of 162 patients met inclusion criteria. Of these, 93 patients had a minimum 2-year follow-up. Of these, 19 had undergone a revision surgery at the index level for cyst recurrence or instability. The revision rate for this group was 20.4%. The median time to initial revision surgery was 2.2 years. The median time from index operation to last follow-up was 3.8 years. No differences were observed between the groups regarding the presence of preoperative spondylolisthesis, age, sex, body mass index, blood loss, or patient demographics. 60.2% of all procedures were done at the L4-5 level, but this level accounted for 73.7% of primary failures. A radiographic analysis showed facet angle >45° at L4-5 to be associated with risk of failure of primary decompression. The presence and absolute amount of fluid in the facets were not associated with risk of failure at the L4-5 level. DISCUSSION: Our revision rate of 20.4% is higher than what is commonly reported in the literature. The radiographic analysis shows that at the L4-5 level, a facet angle of >45° is associated with failure of primary decompression.

Comparison of the history and physical examination for hip osteoarthritis and lumbar spinal stenosis.

BACKGROUND: Leg pain associated with walking is sometimes incorrectly attributed to hip osteoarthritis (OA) or lumbar spinal stenosis (LSS). PURPOSE: This study compared physicians' values of signs and symptoms for diagnosing and differentiating hip OA and LSS to their clinical utility. STUDY DESIGN/SETTING: Musculoskeletal physicians were surveyed with online questionnaires. Patients were recruited from hip and spine specialty practices. PATIENT SAMPLE: Seventy-seven hip OA and 79 LSS patients. OUTCOME MEASURES: Signs and symptoms of hip OA and LSS. METHODS: Fifty-one of 66 invited musculoskeletal physicians completed online surveys about the values of 83 signs and symptoms for diagnosing hip OA and LSS. Of these, the most valued 32 symptoms and 13 physical examination items were applied to patients with symptomatic hip OA or LSS. Positive likelihood ratios (+LR) were calculated for each items' ability to differentiate hip OA from LSS, with a +LR>2 set as indicating usefulness for favoring either diagnosis. Positive LRs were compared with surveyed physicians' values for each test. RESULTS: All symptoms were reported by some patients with each diagnosis. Only 11 of 32 physician-valued symptoms were useful for discriminating hip OA from LSS. Eight symptoms favored hip OA over LSS: groin pain (+LR=4.9); knee pain (+LR=2.2); pain that decreased with continued walking (+LR=3.9); pain that occurs immediately with walking (+LR=2.4); pain that occurs immediately with standing (+LR=2.1); pain getting in/out of a car (+LR=3.3); pain with dressing the symptomatic leg (+LR=3.1); and difficulty reaching the foot of the symptomatic leg while dressing (+LR=2.3). Three symptoms favored LSS over hip OA: pain below the knee (+LR=2.3); leg tingling and/or numbness (+LR=2.7); and some pain in both legs (+LR=2.5). Notable symptoms that did not discriminate hip OA from LSS included: pain is less while pushing a shopping cart (+LR=1.0); back pain (+LR=1.1); weakness and/or heaviness of leg (+LR=1.1); buttocks pain (+LR=1.2); poor balance or unsteadiness (+LR=1.2); pain that increased with weight-bearing on the painful leg (+LR=1.3), and step to gait on stairs (+LR=1.7). Consistent with physicians' expectations, 7 of 13 physical examination items strongly favored hip OA over LSS: limited weight-bearing on painful leg when standing (+LR=10); observed limp (+LR=9); and painful and restricted range-of-motion with any of five hip maneuvers (+LR range 21-99). Four of five tested neurological deficits (+LR range 3-8) favored the diagnosis of LSS over hip OA. CONCLUSIONS: There is substantial crossover of symptoms between hip OA and LSS, with some physician-valued symptoms useful for differentiating these disorders whereas others were not. Physicians recognize the value of the examination of gait, the hip, and lower extremity neurological function for differentiating hip OA from LSS. These tests should be routinely performed on all patients for which either diagnosis is considered. Awareness of these findings might reduce diagnostic errors.

Inciting Events Associated With Cervical Radiculopathy.

BACKGROUND: Cervical radiculopathy (CR) is a clinical diagnosis defined as a combination of neck, shoulder, and arm pain, often accompanied by sensory and motor symptoms. CR is often caused by degenerative spine pathology associated with impingement of a cervical nerve root, and this pathology can be visualized using magnetic resonance imaging (MRI) or computed tomography (CT). [Correction added September 4, 2019, after online publication: 'computer tomography' corrected to 'computed tomography'] Factors that are associated with the onset of CR have not been explored. OBJECTIVE: To investigate the types and frequencies of patient-reported inciting events associated with CR in patients with imaged-confirmed pathologies that correlate with symptoms. DESIGN: Prospective observational case series. SETTING: Two spine physiatry and three orthopedic spine surgery practices. PATIENTS: One hundred twenty-two patients with symptoms suggestive of CR were recruited. Of these, 107 patients had MRI or CT evidence of cervical disk herniation or foraminal stenosis that correlated with symptoms and matched our inclusion criteria. METHODS: We categorized patient-reported inciting events associated with onset of CR into six categories reflecting increasing severity of inciting event, and recorded the clinical characteristics, physical examination findings, pain intensity, and disability. We analyzed the characteristics of patients based on subgroups of inciting events. RESULTS: Two-thirds of patients reported that they either awoke with symptoms or symptoms began without a memorable event, and one-third of patients reported inciting physical activity or trauma associated with the onset of CR. Clinical characteristics of CR were not influenced by categories of inciting events. CONCLUSION: Most CR with correlating spine pathology was found to have onset without a specific inciting events. Furthermore, physical inciting events did not influence the severity of clinical manifestation of CR. LEVEL OF EVIDENCE: IV.

Comparison of Symptoms From C6 and C7 Radiculopathy.

STUDY DESIGN: Case series. OBJECTIVE: This study compared the locations of arm pain, sensory symptoms, and subjective complaints of arm weakness in patients with cervical radiculopathy from MRI confirmed C6 and C7 nerve root compression. SUMMARY OF BACKGROUND DATA: Cervical radiculopathy is defined as arm pain, sensory and motor symptoms caused by irritation of a cervical nerve root. The C6 and C7 roots are most commonly involved, and differentiating symptoms associated with each root has proven difficult. Cervical MRI allows accurate identification of nerve root compression and therefore makes it possible to explore symptom patterns that may differentiate C6 from C7 radiculopathy. METHODS: A total of 122 patients with symptoms suggestive of cervical radiculopathy were recruited. Of these, 30 patients had MRI confirmed C6 and 39 patients C7 nerve root compression. By completing a study questionnaire, patients reported specific arm weakness, and marked the location of arm pain and tingling/numbness on graphic representations of the arm. Marked areas were interpreted by superimposing a grid that divided the arm into 54 distinct areas. The frequencies of reported symptoms with C6 and C7 were totaled and then compared with likelihood rations. Power analysis calculated that 27 patients would be needed in each group based on the assumption that a 30 percentage point difference in frequency of specific symptom would be clinically useful for differentiating C6 from C7 radiculopathy. RESULTS: Arm pain and sensory symptoms were diffuse, and were not distinctly different for C6 or C7 radiculopathy. Some weakness was reported by 41 percent of patients, with specific descriptions of weakness having limited value for differentiating between radiculopathies. CONCLUSION: The location of pain and sensory symptoms, and specific weakness complaints associated with symptomatic C6 and C7 nerve root compression overlap to the extent that caution should be exercised when predicting root involvement based on symptoms. LEVEL OF EVIDENCE: 3.

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.

A RCT comparing 7-year clinical outcomes of one level symptomatic cervical disc disease (SCDD) following ProDisc-C total disc arthroplasty (TDA) versus anterior cervical discectomy and fusion (ACDF).

PURPOSE: The objective of this trial was to compare the safety and efficacy of TDA using the ProDisc-C implant to ACDF in patients with single-level SCDD between C3 and C7. METHODS: We report on the single-site results from a larger multicenter trial of 13 sites using an approved US Food and Drug Administration protocol (prospective, randomized controlled non-inferiority design). Patients were randomized one-to-one to either the ProDisc-C device or ACDF. All enrollees were evaluated pre- and post-operatively at regular intervals through month 84. Visual Analog Scale (VAS) for neck and arm pain/intensity, Neck Disability Index (NDI), Short-Form 36 (SF-36), and satisfaction were assessed. RESULTS: Twenty-two patients were randomized to each arm of the study. Nineteen additional patients received the ProDisc-C via continued access. NDI improved with the ProDisc-C more than with ACDF. Total range of motion was maintained with the ProDisc-C, but diminished with ACDF. Neck and arm pain improved more in the ProDisc-C than ACDF group. Patient satisfaction remained higher in the ProDisc-C group at 7 years. SF-36 scores were higher in the TDA group than ACDF group at 7 years; the difference was not clinically significant. Six additional operations (two at the same level; four at an adjacent level) were performed in the ACDF, but none in the ProDisc-C group. CONCLUSIONS: The ProDisc-C implant appears to be safe and effective for the treatment of SCDD. Patients with the implant retained motion at the involved segment and had a lower reoperation rate than those with an ACDF.

Exploration of sensory impairments associated with C6 and C7 radiculopathies.

BACKGROUND CONTEXT: Cervical radiculopathy is a common disorder caused by compression of the cervical nerve roots and is characterized by arm pain and altered sensory-motor function. Incongruity in the locations of C6 and C7 dermatomes in competing versions of historical dermatome maps has plagued interpretation of impaired sensation associated with C6 and C7 radiculopathies. Magnetic resonance imaging (MRI) allows accurate identification of the C6 or C7 nerve root compression and therefore makes it possible to explore sensory findings that are associated with compression of specific nerve root. PURPOSE: This study compared the locations of impaired sensation in subjects with cervical radiculopathy from MRI-confirmed C6 and C7 nerve root compression. STUDY DESIGN: Case series was used for this study. PATIENT SAMPLE: A total of 122 subjects with symptoms suggestive of cervical radiculopathy were recruited by 11 spine specialist from 5 practice locations. Of these, 30 subjects had MRI-confirmed C6 and 40 subjects C7 radiculopathy. OUTCOME MEASURES: Standardized pinprick sensory examination of the forearm and hand of every subject was performed, and the locations of sensory impairments were recorded. METHODS: Sensory examination was performed before reviewing MRI results or performing motor or reflex examination. Areas of impaired sensation were recorded on drawings of the palmar and dorsal forearm and hand, and translated using a grid into 36 specific areas for analysis. Chi-square was used to compare frequencies of findings for each grid area for C6 and C7 radiculopathies. Power analysis suggested that a minimum of 27 subjects in each group were needed to detect a 30 percentage point difference in frequency of sensory impairments. Significance was set at ≤.05. RESULTS: Approximately 80% of subjects had impaired sensation in at least 1 grid area, most often in the distal forearm and hand, and many had findings in multiple areas. There was nearly complete overlap for locations of impaired sensation for C6 and C7 radiculopathy, and the frequencies of impaired sensation differed only in the dorsal aspect of the distal radial forearm where it was twice as common in C6 radiculopathy (p=.02). CONCLUSIONS: The location of sensory impairments associated with symptomatic C6 and C7 nerve root compression overlap to the extent that caution should be exercised when predicting compression of either the C6 or C7 nerve roots based on locations of impaired sensation. Impaired sensation in the radial aspect of the distal forearm is more common in C6 radiculopathies.

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.

Adjacent segment disc pressures following two-level cervical disc replacement versus simulated anterior cervical fusion.

Anterior cervical fusion (ACF) has been shown to alter the biomechanics of adjacent segments of the cervical spine. The goal of total disc replacement is to address pathology at a given disc with minimal disruption of the operated or adjacent segments. This study compares the pressure within discs adjacent to either a two-level simulated ACDF or a two-level total disc replacement with the ProDisc-C. A special automated motion testing apparatus was constructed. Four fresh cadaveric cervical spine specimens were affixed to the test stand and tested in flexion and extension under specific loads. Intradiscal, miniature strain-gauge-based transducers were placed in the discs above and below the "treated" levels. The specimens were then tested in flexion and extension. Pressure and overall angular displacement were measured. In the most extreme and highest quality specimen the difference at C3/C4 registered 800 kPa and the difference at C6/C7 registered 50 kPa. This same quality specimen treated with the ProDisc reached a flexion angle at much lower moments, 24.3 degrees at 5 N-m, when compared to the the SACF 12.2 degrees at 8.6 N-m. Therefore, the moment needed to achieve 15 degrees of flexion with the SACF treatment was 5.5 N-m and the ProDisc treatment was only 2.9 N-m. This initial data would indicate that adjacent level discs experience substantially lower pressure after two-level disc replacement when compared to two-level SACF. Additional testing to further support these observations is ongoing.

Kyphoplasty: report of eighty-two thoracolumbar osteoporotic vertebral fractures.

OBJECTIVES: Document initial outcomes of balloon kyphoplasty. DESIGN: Retrospective analysis of the first 52 patients with 82 painful vertebral body compression fractures secondary to osteoporosis treated at our institution. SETTING: Operation on subacute painful fractures with office follow-up. PATIENTS/PARTICIPANTS: First 82 fractures in 52 patients treated. All patients had failed nonoperative treatment and had magnetic resonance imaging scans documenting edematous changes of the vertebral body. Forty-nine out of 52 patients presented for follow-up at an average of 37 weeks. INTERVENTION: Minimally invasive balloon reduction via bilateral transpedicular or extrapedicular approaches followed by polymethyl methacrylate fixation. MAIN OUTCOME MEASURES: Vertebral body height, Cobb angle, visual analogue pain scale, Roland-Morris Disability Survey, and complication rate. RESULTS: Mean length of follow-up was 9 months (37 weeks, range 4-99 weeks); improved height 4.6 and 3.9 mm in the anterior and medial columns, respectively (P > 0.05); Cobb angle increased 14% (P < 0.05), visual analogue pain scale score improved 7 points (P < 0.05); Roland-Morris Disability Survey improved 11 points (P < 0.05); no adverse medical or procedural complications; 9.8% cement leakage rate. CONCLUSION: Balloon kyphoplasty safely improves vertebral body height and patient quality of life.