The Impact of Lumbar Spine Disease and Deformity on Total Hip Arthroplasty Outcomes.

Concomitant spine and hip disease in patients undergoing total hip arthroplasty (THA) presents a management challenge. Degenerative lumbar spine conditions are known to decrease lumbar lordosis and limit lumbar flexion and extension, leading to altered pelvic mechanics and increased demand for hip motion. In this study, the effect of lumbar spine disease on complications after primary THA was assessed. The Medicare database was searched from 2005 to 2012 using International Classification of Diseases, Ninth Revision, procedure codes for primary THA and diagnosis codes for preoperative diagnoses of lumbosacral spondylosis, lumbar disk herniation, acquired spondylolisthesis, and degenerative disk disease. The control group consisted of all patients without a lumbar spine diagnosis who underwent THA. The risk ratios for prosthetic hip dislocation, revision THA, periprosthetic fracture, and infection were significantly higher for all 4 lumbar diseases at all time points relative to controls. The average complication risk ratios at 90 days were 1.59 for lumbosacral spondylosis, 1.62 for disk herniation, 1.65 for spondylolisthesis, and 1.53 for degenerative disk disease. The average complication risk ratios at 2 years were 1.66 for lumbosacral spondylosis, 1.73 for disk herniation, 1.65 for spondylolisthesis, and 1.59 for degenerative disk disease. Prosthetic hip dislocation was the most common complication at 2 years in all 4 spinal disease cohorts, with risk ratios ranging from 1.76 to 2.00. This study shows a significant increase in the risk of complications following THA in patients with lumbar spine disease. [Orthopedics. 2017; 40(3):e520-e525.].

Sagittal Balance Correction in Lateral Interbody Fusion for Degenerative Scoliosis.

BACKGROUND: Sagittal balance restoration has been shown to be an important determinant of outcomes in corrective surgery for degenerative scoliosis. Lateral interbody fusion (LIF) is a less-invasive technique which permits the placement of a high lordosis interbody cage without risks associated with traditional anterior or transforaminal interbody techniques. Studies have shown improvement in lumbar lordosis following LIF, but only one other study has assessed sagittal balance in this population. The objective of this study is to evaluate the ability of LIF to restore sagittal balance in degenerative lumbar scoliosis. METHODS: Thirty-five patients who underwent LIF for degenerative thoracolumbar scoliosis from July 2013 to March 2014 by a single surgeon were included. Outcome measures included sagittal balance, lumbar lordosis, Cobb Angle, and segmental lordosis. Measures were evaluated pre-operative, immediately post-operatively, and at their last clinical follow-up. Repeated measures ANOVAs were used to assess the differences between pre-operative, first postoperative, and a follow-up visit. RESULTS: The average sagittal balance correction was not significantly different: 1.06cm from 5.79cm to 4.74cm forward. The average Cobb angle correction was 14.1 degrees from 21.6 to 5.5 degrees. The average change in global lumbar lordosis was found to be significantly different: 6.3 degrees from 28.9 to 35.2 degrees. CONCLUSIONS: This study demonstrates that LIF reliably restores lordosis, but does not significantly improve sagittal balance. Despite this, patients had reliable improvement in pain and functionality suggesting that sagittal balance correction may not be as critical in scoliosis correction as previous studies have indicated. CLINICAL RELEVANCE: LIF does not significantly change sagittal balance; however, clinical improvement does not seem to be contingent upon sagittal balance correction in the degenerative scoliosis population. The DUHS IRB has determined this study meets criteria for an IRB waiver.

Renal artery injury during lateral transpsoas interbody fusion: case report.

Lateral interbody fusion (LIF) via the retroperitoneal transpsoas approach is an increasingly popular, minimally invasive technique for interbody fusion in the thoracolumbar spine that avoids many of the complications of traditional anterior and transforaminal approaches. Renal vascular injury has been cited as a potential risk in LIF, but little has been documented in the literature regarding the etiology of this injury. The authors discuss a case of an intraoperative complication of renal artery injury during LIF. A 42-year-old woman underwent staged T12-L5 LIF in the left lateral decubitus position, and L5-S1 anterior lumbar interbody fusion, followed 3 days later by T12-S1 posterior instrumentation for idiopathic scoliosis with radiculopathy refractory to conservative management. After placement of the T12-L1 cage, the retractor was released and significant bleeding was encountered during its removal. Immediate consultation with the vascular team was obtained, and hemostasis was achieved with vascular clips. The patient was stabilized, and the remainder of the procedure was performed without complication. On postoperative CT imaging, the patient was found to have a supernumerary left renal artery with complete occlusion of the superior left renal artery, causing infarction of approximately 75% of the kidney. There was no increase in creatinine level immediately postoperatively or at the 3-month follow-up. Renal visceral and vascular injuries are known risks with LIF, with potentially devastating consequences. The retroperitoneal transpsoas approach for LIF in the superior lumbar spine requires a thorough knowledge of renal visceral and vascular anatomy. Supernumerary renal arteries occur in 25%-40% of the population and occur most frequently on the left and superior to the usual renal artery trunk. These arteries can vary in number, position, and course from the aorta and position relative to the usual renal artery trunk. Understanding of renal anatomy and the potential variability of the renal vasculature is essential to prevent iatrogenic injury.

C5 palsy after cervical laminectomy and fusion: does width of laminectomy matter?

BACKGROUND CONTEXT: A common complication of cervical laminectomy and fusion with instrumentation (CLFI) is development of postoperative C5 nerve palsy. A proposed etiology is excess nerve tension from posterior drift of the spinal cord after decompression. We hypothesize that laminectomy width will be significantly increased in patients with C5 palsy and will correlate with palsy severity. PURPOSE: The purposes of this study were to evaluate laminectomy width as a risk factor for C5 palsy and to assess correlation with palsy severity. STUDY DESIGN/SETTING: This is a retrospective, single-institution clinical study. PATIENT SAMPLE: Patient population included all patients with cervical spondylotic myelopathy who underwent CLFI between 2007 and 2014 by a single surgeon. Patients who underwent CLFI for trauma, infection, or tumor or had previous or circumferential cervical surgery were excluded. All patients with a new C5 palsy received a postoperative magnetic resonance imaging. An additional computed tomography (CT) scan was ordered to assess hardware. All control patients received a CT scan at 6 months postoperatively to evaluate fusion. OUTCOME MEASURES: The association between width of laminectomy and development of postopeative C5 palsy was measured. METHODS: Patient comorbidities including obesity, smoking history, and diabetes were recorded in addition to preopertaive and postoperative deltoid and biceps motor strength. Sagittal alignment was measured with C2-C7 Cobb angle preopertaive and postoperative radiographs. The width of laminectomy was measured in a blinded fashion on the postoperative CT scan by two observers. RESULTS: Seventeen patients with C5 nerve palsy and 12 controls were identified. There were no baseline differences in age, sex, diabetes, smoking history, number of surgical levels, or sagittal alignment. Body mass index was significantly higher in the control cohort. There was no significant increase in the C3-C7 laminectomy width in patients with postoperative C5 palsy. The width of laminectomy measurments were highly similar between the two observers. There was no correlation between laminectomy width and palsy severity. CONCLUSIONS: This is the largest series of C5 palsies after laminectomy documented with CT imaging. Laminectomy width was not associated with an increased risk of postoperative C5 palsy at any level. Reduction in laminectomy width may not reduce rate of postoperative nerve palsy.

The role of iatrogenic foraminal stenosis from lordotic correction in the development of C5 palsy after posterior laminectomy and fusion.

BACKGROUND: Post-operative C5 nerve root palsy is a known complication following cervical spine surgery. Although several theories have been proposed, there remains no consensus as to the etiology of the palsies. Multiple pre-operative radiographic measures have been assessed for utility in predicting palsy. The purpose of this study is to evaluate published radiographic parameters as well as specifically evaluate the effect of cervical lordosis in the development of C5 palsy to establish thresholds that reliably predict the incidence. METHODS: This study is a retrospective review of 54 consecutive multilevel cervical laminectomy and fusion surgeries performed by a single spine surgeon between June 2007 and February 2014. Pre-operative MRI and pre- and post-operative plain films were assessed to measure anteroposterior diameter (APD) of the spinal cord, cervical laminar angles, anteroposterior foraminal diameters (FD), cervical curvature index (Ishihara), cervical spine angle (C2-7), and C4-5 angle. Univariate analysis through independent t tests was used to compare differences between groups. Stepwise logistic regression was performed to identify pre-operative variables associated with C5 palsy. Receiver operating characteristic curves were created for significant variables to assess predictive accuracy through determining the area under the curve. RESULTS: There were 13 (24%) palsies in the 54 patients in the study. All palsies completely resolved within 6 months. Among pre-operative measures, FD and APD were significantly different between the palsy and non-palsy groups. The average post-operative C4-5 angle was significantly different between the groups, though the cervical spine angle and curvature index, as well as the change in these measures from pre-operative measurements, did not differ significantly between groups. CONCLUSIONS: Post-operative palsy is likely a result of iatrogenic nerve root compression from a decreased in cross-sectional area of the neuroforamen in a patient with pre-operative narrowing of the foramen. However, spinal cord drift back may also play a role from the combined effect of posterior decompression from laminectomy and relative slack afforded by increased lordosis. Accordingly, increased post-operative lordosis would increase the likelihood of effect from both of these mechanisms. We recommended limited conservative lordotic correction in patients with pre-operative foraminal narrowing.

Is polymethyl methacrylate a viable option for salvaging lateral mass screw failure in the subaxial cervical spine?

Study Design Biomechanical analysis of lateral mass screw pullout strength. Objective We compare the pullout strength of our bone cement-revised lateral mass screw with the standard lateral mass screw. Methods In cadaveric cervical spines, we simulated lateral mass screw "cutouts" unilaterally from C3 to C7. We salvaged fixation in the cutout side with polymethyl methacrylate (PMMA) or Cortoss cement (Orthovita, Malvern, Pennsylvania, United States), allowed the cement to harden, and then drilled and placed lateral mass screws back into the cement-augmented lateral masses. On the contralateral side, we placed standard lateral mass screws into the native, or normal lateral, masses and then compared pullout strength of the cement-augmented side to the standard lateral mass screw. For pullout testing, each augmentation group was fixed to a servohydraulic load frame and a specially designed pullout fixture was attached to each lateral mass screw head. Results Quick-mix PMMA-salvaged lateral mass screws required greater force to fail when compared with native lateral mass screws. Cortoss cement and PMMA standard-mix cement-augmented screws demonstrated less strength of fixation when compared with control-side lateral mass screws. Attempts at a second round of cement salvage of the same lateral masses led to more variations in load to failure, but quick-mix PMMA again demonstrated greater load to failure when compared with the nonaugmented control lateral mass screws. Conclusion Quick-mix PMMA cement revision equips the spinal surgeon with a much needed salvage option for a failed lateral mass screw in the subaxial cervical spine.

Use of a medication quantification scale for comparison of pain medication usage in patients with complex regional pain syndrome (CRPS).

OBJECTIVE: To correlate the amount and types of pain medications prescribed to CRPS patients, using the Medication Quantification Scale, and patients' subjective pain levels. DESIGN: An international, multisite, retrospective review. SETTING: University medical centers in the United States, Israel, Germany, and the Netherlands. SUBJECTS/METHODS: A total of 89 subjects were enrolled from four different countries: 27 from the United States, 20 Germany, 18 Netherlands, and 24 Israel. The main outcome measures used were the Medication Quantification Scale III and numerical analog pain scale. RESULTS: There was no statistically significant correlation noted between the medication quantification scale and the visual analog scale for any site except for a moderate positive correlation at German sites. The medication quantification scale mean differences between the United States and Germany, the Netherlands, and Israel were 9.793 (P < 0.002), 10.389 (P < 0.001), and 4.984 (P = 0.303), respectively. CONCLUSIONS: There appears to be only a weak correlation between amount of pain medication prescribed and patients' reported subjective pain intensity within this limited patient population. The Medication Quantification Scale is a viable tool for the analysis of pharmaceutical treatment of CRPS patients and would be useful in further prospective studies of pain medication prescription practices in the CRPS population worldwide.

Posterior single-incision semitendinosus harvest for a quadrupled anterior cruciate ligament graft construct: determination of graft length and diameter based on patient sex, height, weight, and body mass index.

PURPOSE: This study aimed to determine final graft length and diameter for a quadrupled semitendinosus anterior cruciate ligament (ACL) construct harvested from a single-incision posterior approach with correlation to preoperative patient variables of sex, height, weight, and body mass index (BMI). METHODS: This was a retrospective review of data collected prospectively on 60 patients undergoing all-inside quadrupled semitendinosus autograft ACL reconstruction. RESULTS: The mean values of the final quadrupled constructs were a length of 70.3 mm and a diameter of 9.0 mm. Separated based on sex, female versus male final mean graft length was 68.1 mm versus 71.7 mm, and final mean graft diameter was 8.6 mm and 9.3 mm, respectively. In both sexes, patient height and weight were strongly correlated to final construct diameter (r = 0.60 and r = 0.56) and length (r = 0.47 and r = 0.44), respectively. CONCLUSIONS: A single-incision posterior harvest approach allowed for retrieval of semitendinosis tendon autografts of sufficient dimension to allow for construction of quadrupled ACL grafts of a diameter of 8 mm or more in 95% of cases. In addition, desired graft length was achieved in all cases. Graft dimensions had moderately strong direct correlations to patient height and weight, with significant size differences noted between the sexes. We believe this to be helpful data for surgeons who might consider performing a quadrupled semitendinosus autograft ACL reconstruction. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Does a Syrinx Matter for Return to Play in Contact Sports? A Case Report and Evidence-Based Review of Return-to-Play Criteria After Transient Quadriplegia.

Transient quadriplegia is a rare injury that can change the course of an athlete's career if misdiagnosed or managed inappropriately. The clinician should be well versed in the return-to-play criteria for this type of injury. Unfortunately, when an unknown preexisting syrinx is present in the athlete, there is less guidance on their ability to return to play. This case report and review of the current literature illustrates a National Collegiate Athletic Association (NCAA) Division I football player who suffered a transient quadriplegic event during a kickoff return that subsequently was found to have an incidental cervical syrinx on magnetic resonance imaging. The player was able to have a full neurologic recovery, but ultimately he was withheld from football.