Lateral shift of the femoral condyle after total knee arthroplasty: simulation using 2D-templates of the medial pivot design on knee radiographs of young Japanese patients.

BACKGROUND: Total knee arthroplasty (TKA) is an established surgical treatment for advanced knee osteoarthritis by which patients can expect improvement of knee pain and function. Although many surgeons have investigated limb alignment after TKA, changes in coronal positional relation between the femur and tibia are not known well. METHODS: Radiographs of 105 knees of young Japanese patients between 20 and 49 years-old (60 men and 45 women) without osteoarthritic changes who received arthroscopic surgeries at our hospital were used in this study. Using 2D-templates of the medial pivot design (the FINE total knee), we simulated TKA on a SYNAPSE-PACS software. First, the femoral component was placed in normal knee alignment and then was merged to the medial concave of the insert where the tibial component was placed in neutral alignment. The length of the mediolateral shift of the femoral component was measured as an estimate of lateral shift of the femoral condyle, of which association with radiographic parameters including the femorotibial angle (FTA), lateral distal femoral angle (LDFA), and medial proximal tibial angle (MPTA) was analyzed. Subjects were classified into three groups according to the femoral component size that was chosen in simulation of TKA, and the lateral shift of the femoral condyle was compared between groups. RESULTS: The estimated mean lateral shift of the femoral condyle was 5.99 ± 1.98 mm and was greater in males than females (p < 0.05). Also, it was most highly correlated with the medial proximal tibial angle (MPTA) (r = - 0.553, p < 0.01). A group receiving larger component sizes significantly shifted more laterally compared with a group receiving smaller component sizes (p < 0.01). CONCLUSIONS: These results suggest that the coronal positional relation between the femur and tibia is altered and subsequent ligament imbalance may occur after mechanically aligned TKA using the medial pivot design.

Effects of the difference between lumbar lordosis in the supine and standing positions on the clinical outcomes of decompression surgery for lumbar spinal stenosis.

OBJECTIVE: The authors sought to evaluate the relationship between the difference in lumbar lordosis (DiLL) in the preoperative supine and standing positions and spinal sagittal alignment in patients with lumbar spinal stenosis (LSS) and to determine whether this difference affects the clinical outcome of laminectomy. METHODS: Sixty patients who underwent single-level unilateral laminectomy for bilateral decompression of LSS were evaluated. Spinopelvic parameters in the supine and standing positions were measured preoperatively and at 3 months and 2 years postoperatively. DiLL between the supine and standing positions was determined as follows: DiLL = supine LL - standing LL. On the basis of this determination patients were then categorized into DiLL(+) and DiLL(-) groups. The relationship between DiLL and preoperative spinopelvic parameters was evaluated using Pearson's correlation coefficient. In addition, clinical outcomes such as visual analog scale (VAS) and Oswestry Disability Index (ODI) scores between the two groups were measured, and their relationship to DiLL was evaluated using two-group comparison and multivariate analysis. RESULTS: There were 31 patients in the DiLL(+) group and 29 in the DiLL(-) group. DiLL was not associated with supine LL but was strongly correlated with standing LL and pelvic incidence (PI) - LL (PI - LL). In the preoperative spinopelvic alignment, LL and SS in the standing position were significantly smaller in the DiLL(+) group than in the DiLL(-) group, and PI - LL was significantly higher in the DiLL(+) group than in the DiLL(-) group. There was no difference in the clinical outcomes 3 months postoperatively, but low-back pain, especially in the sitting position, was significantly higher in the DiLL(+) group 2 years postoperatively. DiLL was associated with low-back pain in the sitting position, which was likely to persist in the DiLL(+) group postoperatively. CONCLUSIONS: We evaluated the relationship between DiLL and spinal sagittal alignment and the influence of DiLL on postoperative outcomes in patients with LSS. DiLL was strongly correlated with PI - LL, and in the DiLL(+) group, postoperative low-back pain relapsed. DiLL can be useful as a new spinal alignment evaluation method that supports the conventional spinal sagittal alignment evaluation.

Skip decompression surgeries in the treatment of holospinal epidural abscess: a case report.

INTRODUCTION: Holospinal epidural abscess (HEA) extending from the cervical to the lumbosacral spine is an extremely rare condition. Surgical treatment of HEA, which involves extensive decompression of the spinal lesion is difficult in emergency settings. However, the authors successfully treated a case of HEA in critical condition with severe neurological deficits through a combination of skip decompression surgeries and catheter irrigation. CASE PRESENTATION: A 73-year-old man complained of neck and back pain and developed muscle weakness in the upper and lower extremities (C5 AIS D tetraplegia). When he was transferred to our hospital, a marked increase in leukocytes (13330/µL) and C-reactive protein levels (32.11 mg/dL) was observed. Magnetic resonance imaging (MRI) revealed a HEA extending from C1 to S2 levels. Therefore, an emergency posterior decompression on C4-5 and T4-7 was performed, followed by catheter irrigation using a venous catheter. Blood and intraoperative isolated microorganisms were identified as Streptococcus intermedius, which is a rare cause of spinal infection. He experienced marked improvement in pain after surgery. Two months after surgery, the epidural abscess completely disappeared. Motor weakness gradually improved, and he was able to walk without support and showed no pain recurrence during the final follow-up (20 months after surgery). DISCUSSION: Early diagnosis is important for the treatment of HEAs. Therefore, a whole spine MRI is recommended when an extensive spinal epidural abscess is suspected. Decompression surgery at limited spine levels followed by catheter irrigation should be considered in patients with HEA.

Characteristics of relief and residual low back pain after discectomy in patients with lumbar disc herniation: analysis using a detailed visual analog scale.

BACKGROUND: Several authors have reported favorable results in low back pain (LBP) for patients with lumbar disc herniation (LDH) treated with discectomy. However, detailed changes over time in the characteristics and location of LBP before and after discectomy for LDH remain unclear. To clarify these points, we conducted an observational study to determine the detailed characteristics and location of LBP before and after discectomy for LDH, using a detailed visual analog scale (VAS) bilaterally. METHODS: We included 65 patients with LDH treated by discectomy in this study. A detailed VAS for LBP was administered with the patient under 3 different conditions: in motion, standing, and sitting. Bilateral VAS was also administered (affected versus opposite side) for LBP, lower extremity pain (LEP), and lower extremity numbness (LEN). The Oswestry Disability Index (ODI) was used to quantify clinical status. Changes over time in these VAS and ODI were investigated. Pfirrmann grading and Modic change as seen by magnetic resonance imaging (MRI) were reviewed before and 1 year after discectomy to determine disc and endplate condition. RESULTS: Before surgery, LBP on the affected side while the patients were in motion was significantly higher than LBP while they were sitting (p = 0.025). This increased LBP on the affected side in motion was improved significantly after discectomy (p < 0.001). By contrast, the residual LBP while sitting at 1 year after surgery was significantly higher than the LBP while they were in motion or standing (p = 0.015). At 1 year following discectomy, residual LBP while sitting was significantly greater in cases showing changes in Pfirrmann grade (p = 0.002) or Modic type (p = 0.025). CONCLUSIONS: Improvement of LBP on the affected side while the patient is in motion suggests that radicular LBP is improved following discectomy by nerve root decompression. Furthermore, residual LBP may reflect increased load and pressure on the disc and endplate in the sitting position.

Surgical Treatment for Central Sleep Apnea due to Occipitocervical Compression Myelopathy in a Patient with Klippel-Feil Syndrome.

BACKGROUND: Central sleep apnea (CSA) due to occipitocervical compression myelopathy is an extremely rare condition. Here we report a case of surgical treatment for CSA due to occipitocervical compression myelopathy in a patient with Klippel-Feil syndrome. CASE DESCRIPTION: A 60-year-old man had become aware of a gradually progressive clumsiness and gait disturbance without any cause of injury 5 years before. He had complicated respiratory discomfort during sleep for the previous month and visited our hospital. Neurologic examination revealed severe myelopathy. Polysomnography showed CSA and Cheyne-Stokes respiration. Imaging findings showed C2-3 vertebral fusion and severe spinal cord compression caused by hypoplasia of the C1 posterior arch complicated by an anomaly of the vertebral artery. We diagnosed the patient with CSA due to occipitocervical compression myelopathy complicated by Klippel-Feil syndrome. After a simulation using a full-scale 3-dimensional model, resection of the C1 posterior arch and C4-5 laminoplasty was performed. After surgery, both clumsiness and gait disturbance gradually improved. Polysomnography 1 month after surgery showed that the CSA and the Cheyne-Stokes respiration disappeared. CONCLUSIONS: Although a recent report has indicated the cause of sleep apnea in patients with rheumatoid arthritis and occipitocervical disorders as obstructive sleep apnea, a significant improvement of CSA was observed with decompression surgery in this case. Appropriate surgical planning resulted in a favorable outcome.

Time Course of Changes in Serum Oxidative Stress Markers to Predict Outcomes for Surgical Treatment of Lumbar Degenerative Disorders.

Recent reports indicate that oxidative stress is involved in the pathobiology of acute spinal cord injury or compression myelopathy. We conducted an observational study to determine levels of oxidative stress markers in serum from 80 patients who underwent spinal surgery to treat neurological symptoms related to lumbar degenerative disorders. Serum samples were collected before surgery and at 3 months, 6 months, and 1 year after surgery. Derivatives of reactive oxygen metabolites (ROM) in the serum samples were measured to gauge the level of oxidative stress. For preoperative neurological evaluation, patients were assessed for motor weakness in the lower extremities. We divided the patient samples into two groups: ROM decreasing at 1 year after surgery (G group) and ROM increasing at 1 year after surgery (W group). Then, we evaluated clinical outcomes using the visual analog scale and Oswestry disability index (ODI). Among the samples from the 80 enrolled patients, mean ROM levels before surgery increased to 388.5 ± 92.0, indicating the presence of moderate oxidative stress. The level of ROM gradually decreased after surgery and 1 year after surgery: the levels had significantly decreased to 367.6 ± 83.3 (p < 0.05). In patients who exhibited motor weakness, ROM values were significantly increased compared to those patients who had no motor weakness (p < 0.05). In analyses of clinical outcomes, ODI values for the W group 1 year after surgery were significantly higher than those for the G group (p < 0.05). Moderate oxidative stress was present in patients who had lumbar degenerative disorders and the degree of oxidative stress gradually improved within 1 year after surgery. The clinical results suggest that neurogenic oxidative stress can be mitigated by surgery for patients with lumbar degenerative disorders, and residual oxidative stress reflects poor surgical outcomes.

Serum oxidative stress influences neurological recovery after surgery to treat acutely worsening symptoms of compression myelopathy: a cross-sectional human study.

BACKGROUND: Recent reports indicate that oxidative stress induced by reactive oxygen species is associated with the pathobiology of neurodegenerative disorders that involve neuronal cell apoptosis. Here we conducted a cross-sectional study to evaluate serum levels of oxidative stress in cervical compression myelopathy. METHODS: Thirty-six serum samples were collected preoperatively from patients treated for acutely worsening compression myelopathy (AM) and chronic compression myelopathy (CM). Serum levels of oxidative stress markers were evaluated by measuring derivatives of reactive oxygen metabolites (ROM), which reflect concentrations of hydroperoxides. ROM in healthy individuals range from 250 to 300 (U. CARR), whereas ROM >340-400 and > 400 define moderate and severe levels of oxidative stress, respectively. Difference of ROM by the cause of disorders whether cervical spondylotic myelopathy (CSM) or cervical ossification of longitudinal ligament (OPLL), correlations between ROM and patient age, body mass index (BMI), history of smoking, existence of diabetes were examined. Neurological evaluations according to Japanese Orthopaedic Association (JOA) scores were performed and correlated with ROM. RESULTS: ROM increased to 349.5 ± 54.8, representing a moderate oxidative stress, in CM samples. ROM increased to 409.2 ± 77.9 in AM samples, reflecting severe oxidative stress which were significantly higher than for CM samples (p < 0.05). There was no significant difference by the cause of disorders (CSM or OPLL). ROM were significantly increased in AM serum samples from female patients versus AM male and CM patients (p < 0.05). There were no correlations between ROM and age, BMI, history of smoking, and existence of diabetes. A negative correlation between ROM and recovery rate of JOA score (R2 = 0.454, p = 0.047) was observed in the AM group. CONCLUSIONS: Although moderate oxidative stress was present in patients with CM, levels of oxidative stress increased in severity in patients with AM. These results suggest that postsurgical neurological recovery is influenced by severe oxidative stress in AM.

Intradural metastasis to the cauda equina found as the initial presentation of breast cancer: a case report.

BACKGROUND: Intradural extramedullary spinal metastasis is a relatively rare condition. Furthermore, there are few reports with the initial presentation being a neurological symptom from an intradural metastasis. We report a case of a patient with metastasis to the cauda equina from breast cancer found due to neurological symptoms as the initial presentation. CASE PRESENTATION: A 76-year-old Japanese woman who was previously healthy presented to our hospital with bilateral severe buttock and lower extremity pain without any history of injury. A solitary intradural cauda equina mass was found by magnetic resonance imaging at the L2/3 level, and we suspected a schwannoma initially. The patient hoped to undergo surgery due to the severe pain. However, the chest computed tomographic scan obtained to assess the patient's general status showed the suspected breast cancer of the left side and a lung metastasis. Hence, we considered the possibility of cauda equina tumor metastatic from the breast cancer. We performed an L1-3 laminectomy and tumor extirpation. The pathology revealed adenocarcinoma. After surgery, she had relief from pain, and her status remained satisfactory until she died 9 months after surgery. CONCLUSIONS: It is difficult to clarify whether the cauda equina tumor is benign or malignant based only on Magnetic resonance imaging findings. Clinicians should consider the possibility of metastasis when planning the surgery for intradural cauda equina tumor extirpation.

Unilateral laminectomy for bilateral decompression improves low back pain while standing equally on both sides in patients with lumbar canal stenosis: analysis using a detailed visual analogue scale.

BACKGROUND: Unilateral laminectomy for bilateral decompression (ULBD) for lumbar spinal stenosis (LSS) is a less invasive technique compared to conventional laminectomy. Recently, several authors have reported favorable results of low back pain (LBP) in patients of LSS treated with ULBD. However, the detailed changes and localization of LBP before and after ULBD for LSS remain unclear. Furthermore, unsymmetrical invasion to para-spinal muscle and facet joint may result in the residual unsymmetrical symptoms. To clarify these points, we conducted an observational study and used detailed visual analog scale (VAS) scores to evaluate the characteristics and bilateral changes of LBP and lower extremity symptoms. METHODS: We included 50 patients with LSS treated with ULBD. A detailed visual analogue scale (VAS; 100 mm) score of LBP in three different postural positions: motion, standing, and sitting, and bilateral VAS score (approached side versus opposite side) of LBP, lower extremity pain (LEP), and lower extremity numbness (LEN) were measured. Oswestry Disability Index (ODI) was used to quantify the clinical improvement. RESULTS: Detailed LBP VAS score before surgery was 51.5 ± 32.5 in motion, 63.0 ± 30.1 while standing, and 37.8 ± 31.8 while sitting; and showed LBP while standing was significantly greater than LBP while sitting (p < 0.01). After surgery, LBP while standing was significantly improved relative to that while sitting (p < 0.05), and levels of LBP in the three postures became almost the same with ODI improvement. Bilateral VAS scores showed significant improvement equally on both sides (p < 0.01). CONCLUSIONS: ULBD improves LBP while standing equally on both sides in patients with LCS. The improvement of LBP by the ULBD surgery suggests radicular LBP improved because of decompression surgery. Furthermore, the symmetric improvement of LBP by the ULBD surgery suggests unsymmetrical invasion of the paraspinal muscles and facet joints is unrelated to residual LBP.

Axonal damage is remarkable in patients with acutely worsening symptoms of compression myelopathy: biomarkers in cerebrospinal fluid samples.

PURPOSE: To determine levels of biomarkers reflecting damage to axon, myelin, astrocytes, and neuron in cerebrospinal fluid (CSF) of patients with cervical compression myelopathy. METHODS: We collected 69 CSF samples from patients before spinal surgery for acutely worsening compression myelopathy (AM, 20), chronic compression myelopathy (CM, 20), and lumbar canal stenosis (LCS 29; control). We measured levels of phosphorylated neurofilament subunit H (pNF-H), tau (reflecting axonal damage), myelin basic protein (MBP) (reflecting demyelination), S100b (reflecting astrocyte damage), and neuron-specific enolase (NSE) (reflecting neuronal damage). Change of neurological function by surgery was determined using a Japanese Orthopaedic Association (JOA) score for cervical myelopathy. RESULTS: Significantly higher levels of pNF-H were detected in AM compared with those in either CM or LCS (P < 0.01). Significantly higher levels of tau were detected in AM compared with those in CM (P < 0.05). Levels of MBP were undetectable in almost all the patients. Levels of S100b were equivalent in the three groups. Levels of NSE in AM and CM were significantly lower than those in LCS (P < 0.01). The recovery rate of JOA score was significantly greater for patients with AM than CM. We found a positive correlation between pNF-H and recovery of JOA score (r = 0.381, P = 0.018). CONCLUSION: The present results suggest that axonal damage is remarkable compared with demyelination, astrocytic, and neuronal damage in AM. Better clinical outcome in AM with high CSF levels of pNF-H indicates that axonal compensatory plasticity in spinal cord is preserved, and pNF-H can be predictive of good surgical outcome for AM. These slides can be retrieved under Electronic Supplementary Material.