Thomas Kosztowski’s research while affiliated with The Texas Back Institute Research Foundation and other places

While tumors of the spine are a rare cause of myelopathy, a missed or delayed diagnosis can be devastating. Spinal column tumors can be categorized based on their anatomic location within the spine: extradural, intradural extramedullary, and intramedullary and on whether they are primary tumors or metastases. Extradural and intradural masses occur in roughly the same incidence with a slight predilection for extradural masses (60% vs 40% respectively) [1]. Intramedullary or spinal cord tumors however, are very uncommon, constituting only about 5% of the tumors encountered clinically in adults, and up to as many as 30% of tumors in children [2]. The focus of this chapter will be tumors arising or involving the spinal cord itself and unless otherwise specified spinal cord tumors will refer only to intramedullary lesions.KeywordsSpinal tumorsSpinal metastasesMyxopapillary ependymomaHemangioblastomaAstrocytoma

BACKGROUND CONTEXT Cervical spondylotic myelopathy (CSM) tends to produce a progressive decline in function characterized by gait disturbance, worsening balance and loss of upper extremity dexterity. Traditionally, the goal of decompressive surgery for CSM was to arrest neurological deterioration and prevent further disability rather than to provide functional recovery. In recent years, studies utilizing functional outcome measurements (FOMs) have demonstrated objective improvements in gait and balance dysfunction out to three months after surgery for CSM, but 1-year follow-up has yet to be reported. PURPOSE To determine whether the trends in improvements in gait, balance, pain levels, and psychological profiles observed at three months after cervical decompression for CSM continue out to one year postoperatively. STUDY DESIGN/SETTING Prospective, concurrent control cohort study. PATIENT SAMPLE The study included 22 symptomatic CSM patients, 20 age-matched healthy control volunteers (C). OUTCOME MEASURES Gait and balance parameters, neck disability index (NDI), Visual analog scale (VAS) neck, and psychological measures – Tampa Scale for Kinesiophobia (TSK) and Fear Avoidance Beliefs Questionnaire (FABQ). METHODS Patients performed gait and balance evaluations prior to surgery (Pre) and at 3 months (Post3) and 12 months (Post12) postoperatively. Functional data were recorded and analyzed using human motion capture and dynamic surface EMG. Patients also completed outcomes questionaries at the same time points. Repeated measurements and one-way analysis of variance (ANOVA) were used to analyze data. RESULTS Continued improvement in multiple gait parameters was observed out to one year postoperatively: faster walking speed (Post3: 0.92 vs Post12: 0.99 m/s, p=0.048; C: 1.02 m/s, p>0.050), shorter step time (Post3: 0.44 vs Post12: 0.42 s, p=0.041; C: 0.42 s, p>0.050), and longer step length (Post3: 0.52 vs Post12: 0.55, p=0.048; C: 0.57, p>0.050). Additional gains in balance occurred between 3 and 12 months: head total sway (Post3: 57.70 vs Post12: 51.35 cm, p=0.045 cm; C: 46.42, p>0.050) as well as cone of economy (CoE) dimensions in the coronal plane for both the head (Post3: 3.14 vs Post12: 2.55 cm, p=0.037 cm; C: 2.19, p>0.050) and center of mass (Post3: 2.11 vs Post12: 1.85 cm, p=0.034 cm; C: 1.64, p>0.050). There were significant improvements in all PROMs after surgery: VAS neck (Pre: 5.4, Post3, 2.1, Post12 1.3, p<0.021) and NDI (Pre: 44.6, Post3: 28.5, Post12 20.1, p=0.032). Progressive improvements were observed in TSK and FABQ scores (p<0.050). CONCLUSIONS This study reports objective functional measures and psychological outcomes in addition to standard patient-reported outcome measures for CSM patients out to one year postoperatively, thereby providing a comprehensive global assessment of their recovery. Select measures of gait and balance improved at all time points postoperatively and ultimately resembled those of the healthy controls at one year. These results provide important insight regarding the continued recovery that occurs between 3 and 12 months after surgical decompression for CSM. In turn, this information enriches the discussion surgeons can have with patients before and after surgery. FOMs provide both clinicians and patients with a more detailed and sensitive assessment of overall treatment outcomes and the timeframe of functional recovery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Study design A prospective cohort study Objective To determine a classification system for cone of economy (CoE) measurements that defines clinically significant changes in altered balance and to assess if the CoE measurements directly impacts patients reported outcome measures (PROMs). Summary of background data Preoperative functional data is a crucial component of determining patient disability and prognosis. The CoE has been theorized to be the foundation of biomechanical changes that leads to increased energy expenditure and disability in spine patients. PROMs have been developed to quantify the level of debilitation in spine patients but have various limitations. Methods A total of 423 symptomatic adult patients with spine pathology completed a series of PROMs preoperatively including VAS, ODI, Tampa Scale for Kinesiophobia (TSK), Fear and Avoidance Beliefs Questionnaire (FABQ), and Demoralization (DS). Functional balance was tested in this group using a full-body reflective marker set to measure head and center of mass (CoM) sway. Results PROMs scores were correlated with the magnitude of the CoE measurements. Patients were separated by the following proposed classification: CoM coronal sway > 1.5 cm, CoM sagittal sway > 3.0 cm, CoM total sway > 30.0 cm, head coronal sway > 3.0 cm, head sagittal sway > 6.0 cm, and head total sway > 60.0 cm. Significant differences were noted in the ODI (< 0.001), FABQ physical activity (< 0.001–0.009), DS (< 0.001–0.023), and TSK (< 0.001–0.032) across almost all planes of motion for both CoM and head sway. The ODI was most sensitive to the difference between groups across CoM and head sway planes with a mean ODI of 47.5–49.5 (p < 0.001) in the severe group versus 36.6–39.3 (p < 0.001) in the moderate group. Conclusions By classifying CoE measurements by the cutoffs proposed, clinically significant alterations in balance can be quantified. Furthermore, this study demonstrates that across spinal pathology, higher magnitude CoE and range of sway measurements correlate with worsening PROMs. The Haddas’ CoE classification system in this study helps to identify patients that may benefit from surgery and guide their postoperative prognosis.

Background: Changes in balance are common in individuals with spinal disorders and may cause falls. Balance efficiency, is the ability of a person to maintain their center of gravity with minimal neuromuscular energy expenditure, oftentimes referred to as Cone of Economy (CoE). CoE balance is defined by two sets of measures taken from the center of mass (CoM) and head: 1) the range-of-sway (RoS) in the coronal and sagittal planes, and 2) the overall sway distance. This allows spine caregivers to assess the severity of a patient's balance, balance pattern, and dynamic posture and record the changes following surgical intervention. Maintenance of balance requires coordination between the central nervous and musculoskeletal systems. Research question: To discern differences in balance effort values between common degenerative spinal pathologies and a healthy control group. Methods: Three-hundred and forty patients with degenerative spinal pathologies: cervical spondylotic myelopathy (CSM), adult degenerative scoliosis (ADS), sacroiliac dysfunction (SIJD), degenerative lumbar spondylolisthesis (DLS), single-level lumbar degeneration (LD), and failed back syndrome (FBS), and 40 healthy controls were recruited. A functional balance test was performed approximately one week before surgery recorded by 3D video motion capture. Results: Balance effort and compensatory mechanisms were found to be significantly greater in degenerative spinal pathologies patients compared to controls. Head and Center of Mass (CoM) overall sway ranged from 65.22 to 92.78 cm (p < 0.004) and 35.77-53.31 cm (p < 0.001), respectively in degenerative spinal pathologies patients and in comparison to controls (Head: 44.52 cm, CoM: 22.24 cm). Patients with degenerative spinal pathologies presented with greater trunk (1.61-2.98°, p < 0.038), hip (4.25-5.87°, p < 0.049), and knee (4.55-6.09°, p < 0.036) excursion when compared to controls (trunk: 0.95°, hip: 2.97°, and knee: 2.43°). Significance: The results of this study indicate that patients from a wide variety of degenerative spinal pathologies similarly exhibit markedly diminished balance (and compensatory mechanisms) as indicated by increased sway on a Romberg test and a larger Cone of Economy (CoE) as compared to healthy controls. Balance effort, as measured by overall sway, was found to be approximately double in patients with degenerative spinal pathologies compared to healthy matched controls. Clinicians can compare CoE parameters among symptomatic patients from the different cohorts using the Haddas' CoE classification system to guide their postoperative prognosis.

BACKGROUND CONTEXT The sacroiliac joint (SIJ) is an underappreciated pain generator in 15-30% of patients with low back pain. The SIJ functions as a primary structure which transfers loads of the upper body to the lower extremities. Sacroiliac joint dysfunction (SIJD) is characterized by SIJ laxity with symptoms manifesting primarily as low back and lower extremity pain. Additionally, there is growing evidence that gait patterns may also be affected by SIJD. Although there is still much controversy, minimally invasive sacroiliac fusion (SIF) is gaining interest as a procedure for SIJD patients with unremitting pain. SIF aims to reduce SI pain by stabilizing the SIJ and improving structural support between the sacrum and ilium. While positive outcomes for improved pain and reduced opioid consumption have been associated with SIF, there is a lack of research concerning the effects of SIF on functional biomechanics such as gait performance. PURPOSE To quantify the effects of SIF on biomechanical gait parameters of SIJD patients at three months postoperative follow-up compared to their preoperative state. STUDY DESIGN/SETTING Non-randomized, prospective, concurrent cohort study. PATIENT SAMPLE Twelve symptomatic SIJD patients. OUTCOME MEASURES Spatiotemporal parameters, gait range-of-motion (RoM) parameters, and patient-reported outcomes. METHODS Clinical gait analysis was performed one week before surgery (Pre) and three months after surgery (Post). Each patient performed a series of over-ground gait trials at a comfortable, self-selected speed. Data were collected using a motion capture system and three force plates. Back and leg Visual Analog Scale (VAS), Oswestry Disability Index (ODI), Fear Avoidance Beliefs Questionnaire (FABQ), Tampa Scale for Kinesiophobia (TSK), and Demoralization Scale (DS) scores were also collected at both time points. RESULTS Patients showed increased cadence (Pre: 98.39 vs Post: 106.95 steps/min, p=0.018) and walking speed (Pre: 0.87 vs Post: 1.03 m/s, p=0.013). Patients also showed decreases in stride time (Pre: 1.28 vs Post: 1.14 s, p=0.015), step time (Pre: 0.65 vs Post: 0.58 s, p=0.015), and double-support time (Pre: 0.37 vs Post: 0.29 s, p=0.024). Patients show significant decreases in both knee RoM (Pre: 15.25 vs Post: 10.79°, p=0.02) and head motion (Pre: 4.80 vs Post: 3.18 °, p=0.045) in the coronal plane. VAS leg pain score (Pre: 4.25 vs Post: 2.69, p=0.032) improved significantly postoperatively. CONCLUSIONS SIJD patients treated with SIF showed significant improvements in functional gait and leg pain at their three-month follow-up. The results suggest that SIF provides improved lateral stability which in turn results in more efficient knee motion and improved cadence and step efficiency. The improved leg VAS scores reflect this notion as well. The lack of more pronounced improvements in gait and reported outcomes may be due to insufficient follow-up time to account for a full recovery following SIF. This study may serve as a basis for future diagnostic techniques which utilize gait pattern evaluation as an indicator for early development of SIJD. The findings of this study highlight the impacts that SIJD can have on patients daily lives and reinforces the importance of recognizing the SIJ as a contributor to the functional ability of an individual. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Study design: A prospective cohort study. Objective: Quantify the extent of change in dynamic balance and stability in a group of patients with cervical spondylotic myelopathy (CSM) after cervical decompression surgery and to compare them with matched healthy controls. Summary of background data: CSM is a naturally progressive degenerative condition that commonly results in loss of fine motor control in the hands and upper extremities and in gait imbalance. Whereas this was previously thought of as an irreversible condition, more recent studies are demonstrating postoperative improvements in balance and stability. Materials and methods: Thirty subjects with symptomatic CSM and 25 matched asymptomatic controls between the ages of 45 and 75 years underwent functional balance testing using a 3D motion capture system to gather kinematic and spatiotemporal parameters. CSM subjects underwent testing 1 week before surgery and again 3 months postoperatively. Results: Patients with CSM exhibited markedly diminished balance as indicated by increased sway on a Romberg test and requiring significantly more time and a wider stance to complete tandem gait tests. The surgical intervention resulted in improved balance at the 3-month postoperative time point; however, kinematic and spatiotemporal parameters did not completely normalize to the levels observed in asymptomatic controls. Conclusions: Human motion video capture can be used to robustly quantify balance parameters in the setting of CSM. Compared with healthy controls, such patients exhibited increased standing sway and poorer performance on a tandem gait task. The surgical intervention resulted in significant improvement in many of the measures of functional balance, but overall profiles had not completely returned to normal when measured 3 months after surgery. These data reinforce the importance of operative intervention in the treatment of symptomatic CSM with the goal of halting disease progress but the expectation that balance may actually improve postoperatively.

Background: Few studies have described rates of proximal clinical adjacent segment pathology (CASP) after posterior cervical decompression and fusion (PCDF). Objective: To investigate rates of proximal CASP at C2 vs C3 in PCDFs for degenerative spine disease. Methods: A retrospective review of 380 cases of PCDF for degenerative disease with proximal constructs ending at C2 vs C3 was performed. Minimum follow-up was 12 mo. The primary outcome was proximal CASP requiring reoperation. Variable analysis included demographic, operative, and complication data. Results: There were 119 patients in the C2 group and 261 in the C3 group with no significant differences in age, gender, comorbidities, presenting symptoms, or complications. Vertebral artery injury rates were 0.8% in the C2 group and 0.0% in the C3 group (P = .12). No patients in the C2 group had reoperation for proximal CASP, while 5.0% of patients in the C3 group did (P = .01). Patients with arthrodesis up to C3 had an increased risk of proximal failure when the fusion construct crossed the cervicothoracic junction (P = .03). Multivariate logistic regression analysis showed no factors that were independently associated with re-instrumentation for proximal CASP. Conclusion: Instrumenting to the C2 level reduces the risk for proximal CASP compared to fusion only up to C3. The type of instrumentation used at these 2 levels, form of ASP disease at C1-C2, and natural motion of the relevant proximal adjacent joint may contribute to this difference. Furthermore, within the C3 cohort, fusion across the cervicothoracic junction increased the risk for proximal CASP.

BACKGROUND CONTEXT Cervical spondylotic myelopathy (CSM) is a neurologic condition resulting from spinal cord compression due to degenerative narrowing of the spinal canal. It is the most common cause of spinal cord dysfunction in patients older than 50. Symptoms of CSM may include numbness or weakness in the extremities, loss of fine motor dexterity, and difficulty with balance and gait. The natural history is typically one of progressive decline in neurologic function, so surgery to decompress the spinal cord is generally indicated to prevent progression in symptomatic patients. Despite the prevalence of this condition, relatively little quantitative kinematic information is available on the effect of surgical intervention on the gait of patients with CSM. PURPOSE To evaluate for changes in the spine and lower extremity range of motion (RoM) during gait in patients with CSM before and after surgical intervention. STUDY DESIGN/SETTING Non-randomized, prospective, concurrent cohort study. PATIENT SAMPLE Thirty-eight patients with symptomatic CSM. OUTCOME MEASURES Lower extremity and spine range of motion (RoM), spatiotemporal parameters, and pain level. METHODS Clinical gait analysis was performed one week before surgery (Pre) and three months after surgery (Post). Fifty reflective markers (9.5 mm diameter) attached to the patients; bodies were utilized to collect full body three-dimensional kinematics using 10 cameras (VICON) at a sampling rate of 100 Hz. Each patient performed a series of over-ground gait trials at a comfortable, self-selected speed. Neck and mid-back visual analog scale (VAS), Oswestry Disability Index (ODI), and Neck Disability Index (NDI) scores were also collected at both time points. Repeated measurements ANOVA was used to analyze data. RESULTS When comparing preoperative to postoperative gait parameters, significant increases in walking cadence (98.28 vs 103.37 steps/minutes, p=0.004), stride length (1.02 vs 1.07 m, p=0.018), and walking speed (0.86 vs 0.94 m/s, p=0.001) were observed. The amount of time spent in double support decreased after surgery (0.37 vs 0.32 s, p=0.032). The only significant difference in spine and lower extremity joint RoM measures was a decline in coronal RoM of both the knees and ankles postoperatively. VAS neck and mid-back as well as ODI improved significantly postoperatively, while the reduction in NDI did not attain statistical significance. CONCLUSIONS Despite conventional teaching that the goal of surgical intervention for CSM is to halt symptomatic progression, the data presented here demonstrate that significant improvements in gait are frequently observed after surgical management of CSM. Postoperative patients walk more quickly as a result of increased stride length and cadence. Furthermore, they lift their knees and dorsiflex/plantarflex their ankles less, consistent with a more efficient gait pattern. While surgeons should remain conservative with respect to how they counsel patients and set expectations preoperatively, cautious optimism regarding improvements in gait may be warranted in the setting of surgery for CSM. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Tumors originating from the spinal column can be categorized into either primary or metastatic tumors. Primary spinal tumors are relatively rare, comprising less than 10% of all spinal neoplasms, while metastatic spine disease is quite common [1, 2]. Cancer was the second most common cause of death in the United States in 2016 [3]. Complications from metastatic disease are one of the major causes of morbidity and mortality in cancer patients [4]. The skeletal system follows the lung and liver as the third most commonly affected by metastatic disease, and within the skeletal system, the spine is the most frequently involved bone structure [5–8]. Autopsy studies have reported vertebral metastases in 90% of patients with prostate cancer, 74% of those with breast cancer, 45% with lung cancer, and 29% with lymphoma or renal cell carcinoma [9]. Vertebral metastases are a significant cause of pain and suffering in cancer patients, as they can affect neurological function, mobility, and quality of life [10, 11]. Studies have shown that up to half of patients with spinal metastases end up needing some kind of treatment for their symptoms, and 5–10% require surgical intervention [1, 4, 12, 13]. Improving systemic treatments for cancer and lengthened overall survival for cancer patients continue to improve, which has led to an increased overall incidence of spinal metastases [3].

Pathology of the craniocervical junction (CCJ) is challenging to treat due to the complex bony, ligamentous, and neurovascular structures that comprise this region. There are many unique pathologies of the CCJ, including spine tumors, arthritides, and fractures, each of which requires comprehensive treatment strategies, which often include surgery. Determining the optimal surgical approach to the CCJ is based on the goals of surgical intervention and location of the pathology. In general, the approach is dictated based on whether the pathology is ventral or dorsal to the spinal cord, its location within the CCJ, and the extent of involvement of adjacent neurovascular structures. The transmandibular approach, despite its associated morbidity, is a useful technique in the surgical armamentarium to address ventral CCJ pathology. We describe the indications for this approach, how to successfully perform the procedure, and the associated intraoperative and post-operative risks.