Faculty Bibliography

Degenerative spondylolisthesis is a common presentation, yet the best surgical treatment continues to be a matter of debate. Interbody fusion is one of a number of options, but its exact role remains ill defined. The aim of this study was to provide a contemporary review of the literature to help determine the role, if any, of interbody fusion in the surgical treatment of degenerative spondylolisthesis. A systematic review of the literature since 2005 was performed. Details on study size, patient age, surgical treatments, levels of slip, patient reported outcome measures, radiographic outcomes, complications and selected utility measures were recorded. Studies that compared a cohort treated with interbody fusion and at least one other surgical intervention for comparison were included for review. Only studies examining the effect in degenerative spondylolisthesis were included. Two authors independently reviewed the manuscripts and extracted key data. Thirteen studies were included in the final analysis. A total of 565 underwent interbody fusion and 761 underwent other procedures including decompression alone, interspinous stabilisation and posterolateral fusion with or without instrumentation. Most studies were graded Level III evidence. Heterogeneous reporting of outcomes prevented formal statistical analysis. However, in general, studies reviewed concluded no significant clinical or radiographic difference in outcome between interbody fusion and other treatments. Two small studies suggested interbody fusion is a better option in cases of definite instability. Interbody fusion only provided outcomes as good as instrumented posterolateral fusion. However, most studies were Level III, and hence, we remain limited in defining the exact role of interbody fusion-cases with clear instability appear to be most appropriate. Future work should use agreed-upon common outcome measures and definitions.

The diagnosis and treatment of patients who have both hip and lumbar spine pathologies may be a challenge because overlapping symptoms may delay a correct diagnosis and appropriate treatment. Common complaints of patients who have both hip and lumbar spine pathologies include low back pain with associated buttock, groin, thigh, and, possibly, knee pain. A thorough patient history should be obtained and a complete physical examination should be performed in these patients to identify the primary source of pain. Plain and advanced imaging studies and diagnostic injections can be used to further delineate the primary pathology and guide the appropriate sequence of treatment. Both the surgeon and the patient should understand that, although one pathology is managed, the management of the other pathology may be necessary because of persistent pain. The recognition of both entities may help reduce the likelihood of misdiagnosis, and the management of both entities in the appropriate sequence may help reduce the likelihood of persistent symptoms.

BACKGROUND CONTEXT: Adjacent segment degeneration (ASD) has been described after anterior cervical fusion surgeries though ASD is not always clinically relevant. Hilibrand et al described a grading system for ASD after anterior cervical fusion. We expand the ASD definition with an analysis of radiographic adjacent segment pathology (RASP) by also assessing the progression of kyphotic alignment, and spondylolisthesis at adjacent segments in patients following cervical laminoplasty (LP) and posterior cervical decompression and fusion (CDF). PURPOSE: To assess radiographic adjacent segment pathology by analyzing adjacent segment degeneration, and the progression of kyphotic alignment and spondylolisthesis at segments adjacent to operated levels for LP and CDF surgery. STUDY DESIGN/SETTING: Retrospective analysis of cervical radiographs in patients undergoing prior LP and CDF surgery. PATIENT SAMPLE: 64 patients undergoing prior LP and CDF surgery. OUTCOME MEASURES: NDI and mJOA. METHODS: Preoperative and postoperative radiographs were analyzed for ASD, progression of adjacent level kyphosis and spondylolisthesis at proximal, distal or any other segments. The RASP was determined by combining proximal and distal ASD, and the adjacent level kyphosis and spondylolisthesis into one spectrum of disease. The presence and rate of development of adjacent segment pathology was compared for LP and CDF. HRQOLs included NDI and mJOA. RESULTS: 64 patients were included (24 LP and 40 CDF) with mean age 59.9 years (46.9% female) and 30.2 months mean follow-up. Spondylolisthesis at the adjacent segment was more prevalent in CDF (29.2% vs 4.5%). Both LP and CDF demonstrated a similar rate of RASP (LP 40.9%, CDF 44%). NDI correlated with proximal adjacent level degeneration (r = 0.34, p = 0.024) and kyphosis (r = 0.36 p = 0.017). CONCLUSIONS: Both cervical laminoplasty and posterior cervical decompression and fusion are associated with adjacent level degeneration. However, there is a higher rate of adjacent segment spondylolisthesis after CDF. Motion preservation procedures may have less of a role in preventing adjacent level degeneration than previously thought. Adjacent segment degeneration correlated with NDI disability in these patients

Background. Several different techniques exist to address the pain and disability caused by isolated nerve root impingement. Failure to adequately decompress the lumbar foramen may lead to failed back surgery syndrome. However, aggressive treatment often causes spinal instability or may require fusion for satisfactory results. We describe a novel technique for decompression of the lumbar nerve root and demonstrate its effectiveness in relief of radicular symptoms. Methods. Partial facetectomy was performed by removal of the medial portion of the superior facet in patients with lumbar foraminal stenosis. 47 patients underwent the procedure from 2001 to 2010. Those who demonstrated neurogenic claudication without spinal instability or central canal stenosis and failed conservative management were eligible for the procedure. Functional level was recorded for each patient. These patients were followed for an average of 3.9 years to evaluate outcomes. Results. 27 of 47 patients (57%) reported no back pain and no functional limitations. Eight of 47 patients (17%) reported moderate pain, but had no limitations. Six of 47 patients (13%) continued to experience degenerative symptoms. Five of 47 patients (11%) required additional surgery. Conclusions. Partial facetectomy is an effective means to decompress the lumbar nerve root foramen without causing spinal instability.

BACKGROUND CONTEXT: The presence of retrolisthesis has been associated with the degenerative changes of the lumbar spine. However, retrolisthesis in patients with L5-S1 disc herniation has not been shown to have a significant relationship with worse baseline pain or function. Whether it can affect the outcomes after discectomy, is yet to be established. PURPOSE: The purpose of this study was to determine the relationship between retrolisthesis (alone or in combination with other degenerative conditions) and postoperative low back pain, physical function, and quality of life. This study was intended to be a follow-up to a previous investigation that looked at the preoperative assessment of patient function in those with retrolisthesis and lumbar disc herniation. STUDY DESIGN: Cross-sectional study. PATIENT SAMPLE: Patients enrolled in SPORT (Spine Patient Outcomes Research Trial) who had undergone L5-S1 discectomy and had a complete magnetic resonance imaging scan available for review (n=125). Individuals with anterolisthesis were excluded. OUTCOME MEASURES: Time-weighted averages over 4 years for the Short Form (SF)-36 bodily pain scale, SF-36 physical function scale, Oswestry Disability Index (ODI), and Sciatica Bothersomeness Index (SBI). METHODS: Retrolisthesis was defined as a posterior subluxation of 8% or more. Disc degeneration was defined as any loss of disc signal on T2 imaging. Modic changes were graded 1 to 3 and collectively classified as vertebral end plate degenerative changes. The presence of facet arthropathy and ligamentum flavum hypertrophy was classified jointly as posterior degenerative changes. Longitudinal regression models were used to compare the time-weighted outcomes over 4 years. RESULTS: Patients with retrolisthesis did significantly worse with regard to bodily pain and physical function over 4 years. However, there were no significant differences in terms of ODI or SBI. Similarly, retrolisthesis was not a significant factor in the operative time, blood loss, lengths of stay, complications, rate of additional spine surgeries, or recurrent disc herniations. Disc degeneration, modic changes, and posterior degenerative changes did not affect the outcomes. CONCLUSIONS: Although retrolisthesis in patients with L5-S1 disc herniation did not affect the baseline pain or function, postoperative outcomes appeared to be somewhat worse. It is possible that the contribution of pain or dysfunction related to retrolisthesis became more evident after removal of the disc herniation.

Rheumatoid arthritis (RA) is a chronic, systemic infammatory disorder affecting multiple organ systems, joints, ligaments, and bones and commonly involves the cervical spine. Chronic synovitis may result in bony erosion and ligamentous laxity that result in instability and sublux-ation. Anterior atlantoaxial subluxation (AAS) is the most frequently occurring deformity, due to laxity of the primary and secondary ligamentous restraints. Additional manifestations of RA include cranial settling, subaxial subluxation, or a combination of these. Although clinical fndings can be confounded by the severity of multifocal joint and systemic involvement, a careful history is critical to identify symptoms of cervical disease; serial physical examination is the best noninvasive diagnostic tool. Thorough physical and neurologic examinations should be performed in all patients and serial functional assessments charted. Radiographs of the cervical spine with lateral fexion-extension dynamic views should be obtained periodically and used to 'clear' the cervical spine before elective surgery requiring general anesthesia. Advanced imaging, such as magnetic resonance imaging (MRI) or myelography and computed tomography (CT), may be necessary to evaluate the neuraxis. Early initiation of pharmacotherapy may slow progression of rheumatoid cervical disease. Operative intervention before the onset of advanced myelopathy results in improved outcomes compared to the surgical stabilization of patients whose conditions are more advanced. A multidisciplinary approach involving rheumatology, surgery, and rehabilitation is benefcial to optimize outcomes

The incidence of isthmic spondylolysis is approximately 3% to 6% in the general population. Spondylolytic defects involving multiple vertebral levels, on the other hand, are extremely rare. Only a handful of reports have examined the outcomes of surgical treatment of multi-level spondylolysis. Here, we present one case of bilateral pars defects at L3, L4, and L5. The patient, a 46-year-old female, presented with lower back pain radiating into the left lower extremity. Radiographs and CT scans of the lumbar spine revealed bilateral pars defects at L3-L5. The patient underwent lumbar discectomy and interbody fusion of L4-S1 as well as direct repair of the pars defect at L3. There were no postoperative complications, and by seven months the patient had improved clinically. While previous reports describe the use of either direct repair or fusion in the treatment of spondylolysis, we are unaware of reports describing the use of both techniques at adjacent levels.

Pedicle screws (PS) can provide initial stabilization of anterior interbody femoral ring allograft (FRA) lumbar constructs. Translaminar screws (TLS) have also been advocated for this procedure. The objective of this study was to use an in vitro human cadaveric model to compare the stability of one-level anterior interbody lumbar constructs stabilized with PS and those stabilized with TLS. Five human cadaveric spinal motion segments (L4-S2) were biomechanically evaluated in the intact condition and using the follow- ing methods of stabilization: anterior interbody fusion with FRA, anterior FRA supplemented with PS, and anterior FRA supplemented with TLS. Stability was determined for each construct by measuring construct displacement as a function of applied load under the following conditions: compression, flexion, extension, lateral bending to each side, and axial torsion. There were no statistically significant differences in construct stability between FRA supplemented with PS and FRA supplemented with TLS under any of the loading conditions. In selected cases, supplementation of anterior femoral ring allograft with translaminar screws is a viable alternative to supplementation with pedicle screws.

BACKGROUND CONTEXT: Retrolisthesis is relatively rare but when present has been associated with increased back pain and impaired back function. Neither the prevalence of this condition in individuals with lumbar disc herniations nor its possible relation to preoperative back pain and dysfunction has been well studied. PURPOSE: The purposes of this study were as follows: (1) to determine the prevalence of retrolisthesis (alone or in combination with other degenerative conditions) in individuals with confirmed L5-S1 disc herniation who later underwent lumbar discectomy; (2) to determine if there is any association between retrolisthesis and degenerative changes within the same vertebral motion segment; and (3) to determine the relation between retrolisthesis (alone or in combination with other degenerative conditions) and preoperative low back pain, physical function, and quality of life. STUDY DESIGN/SETTING: Cross-sectional study. PATIENT SAMPLE: A total of 125 individuals were identified for incorporation into this study. All patients had confirmed L5-S1 disc herniation on magnetic resonance imaging (MRI) and later underwent L5-S1 discectomy. All patients were enrolled in the Spine Patient Outcomes Research Trial (SPORT) study; data were obtained from the multi-institutional database comprised of SPORT patients from across the United States. OUTCOME MEASURES: Retrolisthesis, degenerative change on MRI, and Modic changes. METHODS: MRI scans of the lumbar spine were assessed at spinal level L5-S1 for all 125 patients. Retrolisthesis was defined as posterior subluxation of 8% or more. Disc degeneration was defined as any loss of disc signal on T2 imaging. Modic changes were graded 1 to 3 and collectively classified as vertebral endplate degenerative changes. The presence of facet arthropathy and ligamentum flavum hypertrophy was classified jointly as posterior degenerative changes. RESULTS: The overall incidence of retrolisthesis at L5-S1 in our study was 23.2%. Retrolisthesis combined with posterior degenerative changes, degenerative disc disease, or vertebral endplate changes had incidences of 4.8%, 16%, and 4.8% respectively. The prevalence of retrolisthesis did not vary by sex, age, race, smoking status, or education level when compared with individuals with normal sagittal alignment. However, individuals with retrolisthesis were more likely to be receiving workers' compensation than those without retrolisthesis. Increased age was found to be associated with individuals having vertebral endplate degenerative changes (both alone and in conjunction with retrolisthesis) and degenerative disc disease. Individuals who had retrolisthesis with concomitant vertebral endplate degenerative changes were more often smokers and had no insurance. The presence of retrolisthesis was not associated with an increased incidence of having degenerative disc disease, posterior degenerative changes, or vertebral endplate changes. No statistical significance was found between the presence of retrolisthesis on the degree of patient preoperative low back pain and physical function. Patients with degenerative disc disease were found to have increased leg pain compared with those patients without degenerative disc changes. CONCLUSIONS: We found no significant relationship between retrolisthesis in patients with L5-S1 disc herniation and worse baseline pain or function. It is possible that the contribution of pain or dysfunction related to retrolisthesis was far overshadowed by the presence of symptoms caused by the concomitant disc herniation. It remains to be seen whether retrolisthesis will affect outcome after discectomy in these patients