Recurrence rate after posterior percutaneous screw fixation without anterior debridement for pyogenic spondylitis compared with conservative treatment: a propensity score-matched analysis.

PURPOSE: Previous studies have shown that percutaneous pedicle screw (PPS) posterior fixation without anterior debridement for pyogenic spondylitis can improve patient quality of life compared with conservative treatment. However, data on the risk of recurrence after PPS posterior fixation compared with conservative treatment is lacking. The aim of this study was to compare the recurrence rate of pyogenic spondylitis after PPS posterior fixation without anterior debridement and conservative treatment. METHODS: The study was conducted under a retrospective cohort design in patients hospitalized for pyogenic spondylitis between January 2016 and December 2020 at 10 affiliated institutions. We used propensity score matching to adjust for confounding factors, including patient demographics, radiographic findings, and isolated microorganisms. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for recurrence of pyogenic spondylitis during the follow-up period in the matched cohort. RESULTS: 148 patients (41 in the PPS group and 107 in the conservative group) were included. After propensity score matching, 37 patients were retained in each group. PPS posterior fixation without anterior debridement was not associated with an increased risk of recurrence compared with conservative treatment with orthosis (HR, 0.80; 95% CI, 0.18-3.59; P = 0.77). CONCLUSIONS: In this multi-center retrospective cohort study of adults hospitalized for pyogenic spondylitis, we found no association in the incidence of recurrence between PPS posterior fixation without anterior debridement and conservative treatment.

Association of two-staged surgery with systemic perioperative complications in lateral lumbar interbody fusion for adult spinal deformity: a propensity score-weighted study.

PURPOSE: Adult spinal deformity (ASD) surgery carries a higher risk of perioperative systemic complications. However, evidence for the effect of planned two-staged surgery on the incidence of perioperative systemic complications is scarce. Here, we evaluated the effect of two-staged surgery on perioperative complications following ASD surgery using lateral lumbar interbody fusion (LLIF). METHODS: The study was conducted under a retrospective multi-center cohort design. Data on 293 consecutive ASD patients (107 in the two-staged group and 186 in the one-day group) receiving corrective surgery using LLIF between 2012 and 2021 were collected. Clinical outcomes included occurrence of perioperative systemic complications, reoperation, and intraoperative complications, operation time, intraoperative blood loss, transfusion, and length of hospital stay. The analysis was conducted using propensity score (PS)-stabilized inverse probability treatment weighting to adjust for confounding factors. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a PS-weighted cohort. RESULTS: In this cohort, 19 (18.4%) patients in the two-staged group and 43 (23.1%) patients in the one-day group experienced any systemic perioperative complication within 30 days following ASD surgery. In the PS-weighted cohort, compared with the patients undergoing one-day surgery, no association with the risk of systemic perioperative complications was seen in patients undergoing two-staged surgery (PS-weighted OR 0.78, 95% CI 0.37-1.63; p = 0.51). CONCLUSION: Our study suggested that two-staged surgery was not associated with risk for perioperative systemic complications following ASD surgery using LLIF.

Correction loss following short-segment posterior fixation for traumatic thoracolumbar burst fractures related to endplate and intervertebral disc destruction.

BACKGROUND: There has been widespread use of short-segment posterior fixation (SSPF) for traumatic thoracolumbar burst fractures. The relationship between the destruction of the vertebral endplate and adjacent disc and postoperative correction loss has been studied in only a few studies. This study investigated the risk factors for correction loss following SSPF. METHODS: Forty-eight patients (mean age 35.0 years) who underwent SSPF for thoracolumbar burst fractures were enrolled. The mean follow-up period was 25.7 months (12-98 months). The neurological status and postoperative back pain were assessed by the medical records. Segmental kyphotic angle (SKA) and anterior vertebral body height ratio (AVBHR) were measured radiographically to assess indirect vertebral body reduction and local kyphosis. Preoperative Sander's traumatic intervertebral disc lesion (TIDL) classification and AO classification were used to evaluate the severity of disc and vertebral endplate injury. The corrective loss was considered present if ΔSKA was ≥10°. A multivariate logistic regression analysis was performed to identify the risk factors associated with postoperative loss of correction. RESULTS: The fracture distribution was as follows: 10 at T12, 17 at L1, 10 at L2, 9 at L3, and 2 at L4. Vertebral fractures were classified in the following way: A3 in 13 patients, A4 in 11, B1 in 11, and B2 in 13. In 47 patients (98%), a union of the fractured vertebrae was achieved. SKA and AVBHR improved significantly after surgery from 11.6° to 3.5° and from 67.2 to 90.0%, respectively. However, the correction loss at follow-up was 10.4° and 9.7%, respectively. Twenty patients (42%) had severe TIDL (grade 3). Postoperative ΔSKA and ΔAVBHR were significantly higher in patients with TIDL grade 3 than with TIDL grade 0-2. The presence of cranial TIDL grade 3 and older age were significant risk factors for ΔSKA ≥10° on multivariate logistic regression analysis. All patients could walk at follow-up. TIDL grade 3 and ΔSKA ≥10° were associated with severe postoperative back pain. CONCLUSIONS: Risk factors for loss of correction after SSPF for thoracolumbar burst fractures were severe disc and endplate destruction at the time of injury and older age.

Association of preoperative muscle composition of the lower extremity with gait function after total knee arthroplasty.

BACKGROUND: Limitations of gait function persist in some patients with knee osteoarthritis after total knee arthroplasty. This study aimed to identify preoperative muscle composition variables of the operated limb associated with postoperative gait function. METHODS: Longitudinal data from 45 patients who underwent unilateral primary total knee arthroplasty were retrospectively analyzed. Timed Up-and-Go test and gait speed were measured preoperatively and at 3 and 6 months postoperatively. Preoperative muscle composition in the glutei medius and minimus, the quadriceps, the hamstrings, and combination of the hamstrings and quadriceps were evaluated by computed tomography. The area ratio of the individual muscle composition to the total muscle was calculated. The factors associated with Timed Up-and-Go test and gait speed were identified using stepwise regression analysis. RESULTS: Shorter Timed Up-and-Go test and faster gait speed at each time point correlated with higher lean muscle mass area of the total hamstrings, higher area ratio of lean muscle mass to the total hamstrings or to combination of the hamstrings and quadriceps, and lower area ratio of low density lean tissue or intramuscular adipose tissue to the total hamstrings. Shorter Timed Up-and-Go test at each time point also correlated with higher combined area of lean muscle mass of the hamstrings and quadriceps. Faster gait speed at each time point additionally correlated with lower area ratio of intramuscular fat to the total hamstrings and lower area ratio of lean tissue mass or intramuscular adipose tissue to combination of the hamstrings and quadriceps. Regression analysis using the significant muscle composition variables revealed that the area ratio of lean muscle mass to the total hamstrings was the only predictor of Timed Up-and-Go test and gait speed after operation. CONCLUSIONS: Preoperative area ratio of ipsilateral lean muscle mass to the total hamstrings could predict gait function after total knee arthroplasty.

Wrong-level spine surgery: A multicenter retrospective study.

BACKGROUND: Wrong-level spine surgery is a rare but serious complication of spinal surgery that increases patient harm and legal risks. Although such surgeries have been reported by many spine surgeons, they have not been adequately investigated. Therefore, this study aimed to examine the causes and preventive measures for wrong-level spine surgeries. METHODS: This study analyzed cases of wrong-level spine surgeries from 10 medical centers. Factors such as age, sex, body mass index, preoperative diagnosis, surgical details, surgeon's experience, anatomical variations, responses, and causes of the wrong-level spine surgeries were studied. The methods used by the surgeons to confirm the surgical level were also surveyed using a questionnaire for each surgical procedure and site. RESULTS: Eighteen cases (13 men and 5 women; mean age, 61.2 years; mean body mass index, 24.5 kg/m2) of wrong-level spine surgeries were evaluated in the study. Two cases involved emergency surgeries, three involved newly introduced procedures, and five showed anatomical variations. Wrong-level spine surgeries occurred more frequently in patients who underwent posterior thoracic surgery than in those who underwent other techniques (p < 0.01). Twenty-two spinal surgeons described the methods used to confirm the levels preoperatively and intraoperatively. In posterior thoracic laminectomies, half of the surgeons used preoperative markers to confirm the surgical level and did not perform intraoperative fluoroscopy. In posterior thoracic fusion, all surgeons confirmed the level using fluoroscopy preoperatively and intraoperatively. CONCLUSIONS: Wrong-level spine surgeries occurred more frequently in posterior thoracic surgeries. The thoracic spine lacks the anatomical characteristics observed in the cervical and lumbar spine. The large drop in the spinous process can make it challenging for surgeons to determine the positional relationship between the spinous process and the vertebral body. Moreover, unfamiliarity with the technique and anatomical variations were also risk factors for wrong-level spine surgeries.

Acute non-traumatic spinal subarachnoid hematomas: A report of five cases and a systematic review of literature.

BACKGROUND: There is a lack of evidence on spinal subarachnoid hematomas because of the rarity of their spontaneous development and difficulty in diagnosis. The aim of this study was to identify the characteristics and outcomes of surgically confirmed acute non-traumatic spinal subarachnoid hematomas from a multicenter surgical database and conduct a systematic review of existing literature. METHODS: Five surgically confirmed cases of acute non-traumatic spinal subarachnoid hematomas were identified from our multicenter database with 22 cases from a systematic review of existing literature. RESULTS: The mean age of the 27 patients was 59 years. The length of the hematoma was longer than five vertebrae in 70% of the patients, most commonly distributed in the thoracic spine; 63% of all cases were idiopathic, 30% were under anticoagulant therapy, and the remaining 7% presented with coagulation abnormalities. As many as 70% of the patients showed some improvement in neurological symptoms after surgery during a mean follow-up period of 14 months. CONCLUSIONS: This study elucidated the characteristics of acute non-traumatic spinal subarachnoid hematomas in patients who were surgically confirmed. Most patients were middle-aged, complained of back pain, and had the hematoma located in the thoracic spine. Seventy percent of the patients in this study had some improvement in their neurological status, most likely due to surgical decompression and hematoma evacuation.

Mortality related to and functional outcomes of upper cervical spine fractures in the elderly.

BACKGROUND: Although the mortality related to hip fracture and osteoporotic vertebral fracture have been reported, few studies have examined the mortality related to atlas and/or axis fractures. The aim of this study was to assess the association between mortality and atlas and/or axis fractures retrospectively and to elucidate the efficacy of surgical treatment. METHODS: A total of 33 elderly patients who were treated for atlas and/or axis fractures at our institution between January 2012 and December 2018 were included in this study. These patients were divided into two groups: surgical treatment and conservative treatment. Fracture types, comorbidities, neurological status, treatment types, and walking ability at follow-up were reviewed. Mortality was assessed using medical records or via phone interviews. RESULTS: The mean age at injury was 79.9 ± 8.0 years, and the mean follow-up period was 2.3 years. The overall mortality rates at 1 and 5 years were 21.4% and 48.4%, respectively. During the observation period, 12 (36%) patients died. Twenty-two patients were treated conservatively (14 were treated with a cervical collar, 8 were treated with a halo vest). Surgical procedures included occipital-cervical fixation, osteosynthesis of C2 fractures, C1-2 fixation, and C1-4 fixation using a posterior approach. Surgical treatment correlated with better survival rates. There was no significant difference between the two groups in terms of ambulatory ability and functional recovery. CONCLUSION: Upper cervical spine fractures appear to have a worse prognosis compared to hip and osteoporotic vertebral fractures. This study indicates the efficacy of surgical treatment for upper cervical spine fractures in the elderly for improving survival prognosis.

Neurological severity evaluation using magnetic resonance imaging in acute spontaneous spinal epidural haematomas.

PURPOSE: This study aimed to elucidate the severity of neurological deficits in a large series of patients with acute spontaneous spinal epidural haematoma (SSEH) using magnetic resonance imaging (MRI). METHODS: We included 57 patients treated for acute SSEH at 11 institutions and retrospectively analysed their demographic and MRI data upon admission. We investigated MRI findings, such as the haematoma length and canal occupation ratio (COR). The neurological severity of SSEH was assessed based on the American Spinal Injury Association score on admission. RESULTS: Of the 57 patients, 35 (61%) presented with severe paralysis. The MRI analysis showed that SSEH was often located in the cervical spine, dorsal to the spinal cord, and spread over more than three vertebrae. No differences in age, sex, and aetiology were found between patients with and without severe paralysis. The hypo-intensity layer encircling the haematoma, intra-haematoma heterogeneity, and increased CORs were observed more frequently in the severe paralysis group. Furthermore, pathological examination of a dissected haematoma from one patient with a hypo-intensity layer revealed a collagen layer around the haematoma, and patients with intra-haematoma heterogeneity were more likely to have a bleeding predisposition. CONCLUSIONS: In this large series of patients with SSEH, we identified some MRI features associated with severe paralysis, such as the hypo-intensity layer, intra-haematoma heterogeneity, and increased COR. Accordingly, patients with these MRI characteristics should be considered for early surgical intervention.

Radiographic risk factors and surgical outcomes for retroodontoid pseudotumors.

STUDY DESIGN: Retrospective review. OBJECTIVE: The aim of this study is to assess the radiographic characteristics of patients with a retroodontoid pseudotumor and to evaluate the efficacy of posterior fusion. SUMMARY OF BACKGROUND DATA: Retroodontoid pseudotumors are usually caused by chronic atlantoaxial instability in patients with rheumatoid arthritis (RA). However, the pathomechanism and optimum treatment are unknown. METHODS: We reviewed the charts and radiographs of 11 patients (5 RA and 6 non-RA) with a retroodontoid pseudotumor who underwent posterior fusion. Preoperative radiographs were evaluated for atlantodental interval; Redlund-Johnell criterion; O-C1, C1-2, C2-3, and C2-7 angles. The Japanese Orthopaedic Association (JOA) score was used to evaluate clinical outcomes. RESULTS: All RA patients and 1 non-RA patient displayed atlantoaxial subluxation. Three patients underwent occipitocervical fusion and 8 patients atlantoaxial fusion. The JOA score improved significantly from 10.0 to 12.8 at follow-up (P<0.01). The retroodontoid pseudotumor regressed in 10 patients. Maximal thickness of the pseudotumor decreased from 8.9 mm preoperatively to 5.3 mm (P<0.01) at follow-up. In non-RA patients, the mean differences (Δ) between flexion and extension were 7.8, 13.4, 3.5, and 18.5 degrees for ΔO-C1, ΔC1-2, ΔC2-3, and ΔC2-7, respectively. CONCLUSIONS: In RA patients, a retroodontoid pseudotumor may develop because of atlantoaxial subluxation. In non-RA patients, excessive atlantoaxial angular motion because of the limited range of motion of O-C1 and/or subaxial vertebra may cause a pseudotumor. Atlantoaxial fusion to suppress atlantoaxial instability is one of the optimum treatments.

Characteristic loosening of the distally straight cylindrical femoral stem.

BACKGROUND: The cemented femoral stem with a distally straight cylindrical shape was designed to fill the distal femoral canal to facilitate higher cement pressurization and stability. We examined the mid-term outcomes of a stem made of titanium alloy and the efficacy of this shape. METHODS: Four hundred and twenty-nine consecutive patients (505 hips), who underwent a total hip arthroplasty with the distally straight cylindrical stem made of titanium alloy as their primary hip arthroplasty at two institutes, were followed for a minimum 2 years. Loosening was defined as subsidence of over 3 mm, tilting of the femoral component, or fracture of the cement or the stem. A continuous radiolucent line along the entire interface was considered to indicate loosening, too. We examined the interface stresses on the distally straight cylindrical stem compared with a newly manufactured femoral prosthesis with a double-taper design using a finite element model study. RESULTS: The mean follow-up was 101.3 months after surgery. Thirty patients (30 hips) had aseptic loosening of the stems. Of these 30 hips, 18 had osteolysis, 17 showed subsidence, and 11 had cement fractures at the tip of the stem. These 11 hips had osteolysis and ectasia in the same place: the stem tip. The stem survival rate with stem loosening as the end-point was 94.4 % at 10 years and 66.9 % at 15 years. A finite element model study revealed higher stress around the tip of the cylindrical stem compared with that in the double-taper stem. CONCLUSIONS: The straight cylindrical stem is potentially subject to early failure because of high stress around the tip of the stem, and showed a characteristic loosening with osteolysis and ectasia at the tip of the stem.

Prognostic Factors after Surgical Treatment for Spinal Metastases.

Study Design: A retrospective multicenter case series was conducted. Purpose: This study aimed to investigate survival and prognostic factors after surgery for a metastatic spinal tumor. Overview of Literature: Prognostic factors after spinal metastasis surgery remain controversial. Methods: A retrospective multicenter study was conducted. The study participants included 345 patients who underwent surgery for spinal metastases from 2010 to 2020 at nine referral spine centers in Japan. Data for each patient were extracted from medical records. To identify the factors predicting survival prognosis after surgery, univariate analyses were performed using a Cox proportional hazards model. Results: The mean age was 65.9 years. Common primary tumors were lung (n=72), prostate (n=61), and breast (n=39), and 67.8% (n=234) presented with osteolytic lesions. The epidural spinal cord compression scale score 2 or 3 was recognized in 79.0% (n=271). Frankel grade A paralysis accounted for 1.4% (n=5), and 73.3% (n=253) were categorized as intermediate or high risk according to the new Katagiri score. The overall survival rates were -71.0% at 6 months, 57.4% at 12, and 43.3% at 24. In the univariate analysis, Frankel grade A (hazard ratio [HR], 3.59; 95% confidence interval [CI], 1.23-10.50; p<0.05), intermediate risk (HR, 3.34; 95% CI, 2.10-5.32; p<0.01), and high risk (HR, 7.77; 95% CI, 4.72-12.8; p<0.01) in the new Katagiri score were significantly associated with poor survival. On the contrary, postoperative chemotherapy (HR, 0.23; 95% CI, 0.15-0.36; p<0.01), radiation therapy (HR, 0.43; 95% CI, 0.26-0.70; p<0.01), and both adjuvant therapy (HR, 0.21; 95% CI, 0.14-0.32; p<0.01) were suggested to improve survival. Conclusions: Surgical indications for patients with Frankel grade A or intermediate or high risk in the new Katagiri score should be carefully considered because of poor survival. Chemotherapy or radiation therapy should be considered after surgery for better survival.

Risk factors for preoperative neurological impairment in patients with spinal meningioma: A retrospective multicenter study.

BACKGROUND: Patients with spinal meningioma may present preoperatively with paralysis and sensory deficits. However, there is a paucity of detailed evaluations and a lack of consensus regarding imaging findings that are predictive of neurological symptoms in patients with spinal meningioma. METHODS: Herein, a total of 55 patients who underwent surgical resection of spinal meningiomas in eight hospitals between 2011 and 2021 were enrolled. Patient characteristics, degree of muscle weakness, sensory disturbances, and the presence of bowel/bladder dysfunction (BBD) before surgical treatment were evaluated using medical records. Patients with American Spinal Injury Impairment Scale grades A-C and the presence of BBD were classified into the paralysis (+) group. Patients with sensory disturbances were assigned to the sensory disturbance (+) group. Based on magnetic resonance (MR) and computed tomography images, the tumor location was classified according to the spinal level and its attachment to the dura mater. To evaluate tumor size, the tumor occupation ratio (OR) was calculated using the area and distance measurement method in horizontal MR images, and the maximum length and area of the tumor in the sagittal plane were measured. RESULTS: Of all patients, 85 % were women. The mean age of patients at surgery was 69.7 years. Twenty-eight (51 %) and 41 (75 %) patients were classified into the paralysis (+) and sensory disturbance (+) groups, respectively. The average tumor length and area in the sagittal plane were 19.6 mm and 203 mm2, respectively; OR-area and diameters were 70.3 % and 72.3 %, respectively. In univariate analyses, tumor length and area in the sagittal plane were significant risk factors for paralysis. OR-diameter, symptom duration, and a low MIB-1 index correlated with sensory disturbances. Multivariate logistic regression analysis demonstrated that the area and length of the tumor in the sagittal plane were significantly correlated with paralysis, whereas the OR-diameter and symptom duration significantly correlated with sensory disturbances. The cut-off values for the area and length of the tumor in the sagittal plane to predict paralysis were 243 mm2 and 20.1 mm, respectively. CONCLUSIONS: Preoperative paralysis in patients with spinal meningiomas was significantly associated with sagittal tumor size than with high tumor occupancy in the horizontal plane. Sensory disturbances were associated with high occupancy in the horizontal plane. Patients with spinal meningiomas > 20 mm in length or 243 mm2 in area in the sagittal plane are at risk of developing paralysis and could be considered for surgery even in the absence of paralysis.

Unilateral atlantal lateral mass hypertrophy associated with atlanto-occipital fusion.

PURPOSE: Unilateral hypertrophy of the lateral mass of the atlas is an extremely rare condition. The authors present a rare type of unilateral atlantal mass hypertrophy with atlanto-occipital fusion which is associated with an invaginated lateral mass of the atlas and the odontoid process into the foramen magnum. METHODS: A 45-year-old woman presented with a 2-year history of progressive bilateral weakness in the upper and lower extremities and gait disturbance. The left lateral mass of the atlas was hypertrophied and had invaginated into the foramen magnum with the odontoid. The spinal cord was severely compressed at the level of the foramen magnum, surrounded by the lateral mass of the atlas, the odontoid process and the occipital bone. RESULTS: First, ventral decompression was performed using a transmandibular approach. The anterior arch of the atlas, the medial side of the hypertrophied lateral mass and the odontoid process were resected. Two weeks after primary surgery, posterior occipitocervical fusion was performed. The postoperative course of the patient was uneventful. Three years after the operation, she could walk without assistance and her paresthesia improved. CONCLUSIONS: To our knowledge, such a case of unilateral atlantal mass hypertrophy associated with atlanto-occipital fusion has not been described previously. The authors discuss the pathology of this case and review the literature on unilateral atlantal mass hypertrophy and associated anomalies of the upper cervical spine.

Preoperative Lower-Limb Muscle Predictors for Gait Speed Improvement after Total Hip Arthroplasty for Patients with Osteoarthritis.

This study aimed to identify preoperative lower-limb muscle predictors for gait speed improvement after total hip arthroplasty (THA) with hip osteoarthritis. Gait speed improvement was evaluated as the subtraction of preoperative speed from postoperative speed. The preoperative muscle composition of ipsilateral hip abductors was evaluated using computed tomography. The females (n = 45) showed smaller total cross-sectional areas of the gluteal muscles than the males (n = 13). The gluteus maximus in the females showed lower lean muscle mass area (LMM) and higher ratios of the intramuscular fat area and the intramuscular adipose tissue area to the total muscle area (TM) than the males. Regression analysis revealed that LMM/TM of the glutei medius and minimus may correlate negatively with postoperative improvement in gait speed. Receiver operating characteristic curve analysis for prediction of minimum clinically important improvement in gait speed at ≥0.32 m/s resulted in the highest area under the curve for TM in the upper portion of the gluteus maximus with negative correlation. The explanatory variables of hip abductor muscle composition predicted gait speed improvement after THA more precisely in the females compared with the total group of both sexes. Preoperative muscle composition should be evaluated separately based on sex for the achievement of clinically important improvement in gait speed after THA.

Risk Factors for the Incidence of the Volar Lunate Facet Fragments in Distal Radius Fractures.

Background The volar lip of the distal radius is the key structure for wrist joint stability. Rigid fixation of the volar lunate facet (VLF) fragment is difficult because of its unique anatomy, and a high rate of postoperative displacement was demonstrated. Purposes The aim of the study is to identify risk factors for VLF in distal radius fractures (DRFs) and to reconsider the important point for primary fixation. Patients and Methods One hundred fifty-five patients who underwent open reduction and internal fixation for an DRF were included and classified into one of the following two groups: VLF(+)or VLF(-). Demographic data, including age, sex, body mass index (BMI), laterality, trauma mechanism, and AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification were recorded. Several parameters were investigated using wrist radiographs of the uninjured side and computed tomography scans of the injured side. Univariate and multivariate logistic regression analyses were performed to evaluate the risk factors for VLF. Results There were 25 patients in the VLF(+) group and 130 patients in the VLF(-) group. The incidence of VLF was 16.1%. The VLF(+) group tended to have a higher BMI and higher energy trauma mechanism. The odds ratio for the sigmoid notch angle (SNA), volar tilt (VT), and lunate facet curvature radius (LFCR) were 0.84, 1.32, and 0.70, respectively, with multivariate analysis, which was significant. A smaller SNA, larger VT, and smaller LFCR are potential risk factors for VLF. Conclusion Over-reduction of the VT at primary fixation should be avoided because it could place an excess burden on the VLF and cause subsequent postoperative fixation failure and volar carpal subluxation. Level of Evidence IV.

Risk Factors for Reintubation After Anterior Cervical Spine Surgery: Comparative Study of Patients With Cervical Spine Trauma and Patients With Cervical Degenerative Disease.

STUDY DESIGN: Single-center retrospective study. OBJECTIVES: The aim was to compare the postoperative outcomes of anterior cervical spine surgery (ACSS) in patients with and without cervical spine trauma. SUMMARY OF BACKGROUND: Few papers have addressed airway obstruction after anterior ACSS for patients with cervical spine trauma. This study aimed to compare airway obstruction after ACSS between patients with cervical degenerative disorders and cervical spine injuries and identify the risk factors for unplanned postoperative reintubation. MATERIALS AND METHODS: Seventy-seven patients who underwent ACSS were enrolled in this retrospective study. There were 52 men and 25 women, with a mean age of 60.3±15.5 years old. The causes of surgery were as follows: 24 cervical spine fractures or dislocations, 12 spinal cord injuries without bony fracture, 19 disc herniations, and 22 myelopathies. The patients' characteristics, operative data, and risk factors for unplanned reintubation within 5 days postoperatively were analyzed using medical records. RESULTS: Postoperative reintubation was performed in 3 patients (3.9%), all of whom suffered trauma. We further examined risk factors for reintubation in patients in the trauma group. There was no significant difference between the reintubation (R) and nonreintubation (non-R) groups in age, sex, body mass index, amount of blood loss and operation time, preoperative paralysis severity, and the number of fused segments. Patients in group R had significantly higher rates of severe anterior element injury (100% vs. 27.3%, P=0.0011). Airway obstruction due to laryngopharyngeal edema and swelling was confirmed by laryngoscopy and computed tomography images. CONCLUSIONS: Unplanned reintubation after ACSS occurred at a higher rate in trauma patients than in patients with degenerative disorders. Our results suggested that the severe damage to the anterior element of the cervical spine was associated with postoperative reintubation. EVIDENCE LEVEL: Level IV.

Association of preoperative variables of ipsilateral hip abductor muscles with gait function after total hip arthroplasty: a retrospective study.

BACKGROUND: This study aimed to identify the association of preoperative variables of ipsilateral hip abductors with gait function after total hip arthroplasty (THA). METHODS: This study enrolled 42 patients who underwent unilateral primary THA for osteoarthritis. Gait speed and Timed Up-and-Go test were conducted 6 months postoperatively. Preoperative composition of the glutei medius and minimus and the upper portion of gluteus maximus was evaluated by computed tomography. Cross-sectional area ratio of individual composition to the total muscle was calculated. Preoperative variables associated with gait speed and Timed Up-and-Go test after THA were identified by using stepwise regression analysis. RESULTS: Faster gait speed and shorter Timed Up-and-Go test correlated with smaller cross-sectional area of low-density lean tissue or intramuscular adipose tissue (low-density lean tissue plus intramuscular fat) in the glutei medius and minimus and lower cross-sectional area ratio of low-density lean tissue to the total glutei medius and minimus. Faster gait speed and shorter Timed Up-and-Go test also correlated with larger cross-sectional area of lean muscle mass in the gluteus maximus, higher cross-sectional area ratio of lean muscle mass to the total gluteus maximus, and lower cross-sectional area ratio of intramuscular fat or intramuscular adipose tissue to the total gluteus maximus. Faster gait speed additionally correlated with larger total cross-sectional area of the gluteus maximus. Regression analysis showed that the total cross-sectional area of the gluteus maximus and the low-density lean tissue cross-sectional area of the glutei medius and minimus were the explanatory variables of gait speed and Timed Up-and-Go test after THA, respectively. CONCLUSIONS: There was a potential association between preoperative composition of ipsilateral hip abductors and gait function 6 months after THA. This study indicates a predictive role of preoperative assessment of ipsilateral hip abductor composition in the recovery of gait function after THA.

The Efficacy and Complications of Preoperative Embolization of Metastatic Spinal Tumors: Risk of Paralysis after Embolization.

Introduction: This study investigated the efficacy and complications of preoperative embolization for spinal metastatic tumors, focusing on the etiology of post-embolization paralysis. Methods: We retrospectively reviewed the data of 44 consecutive patients with spinal metastases treated between September 2012 and December 2020. Intraoperative blood loss and postoperative transfusion requirement were compared between the embolization (+) and (-) groups. Complications associated with embolization were reviewed. Results: Overall, 30 patients (68%) underwent preoperative embolization. All the patients in both groups underwent palliative posterior decompression and fusion. The mean intraoperative blood loss in the overall population was 359 ml (range, minimum-2190 ml) and was 401 ml and 267 ml in the embolization (+) and embolization (-) groups, respectively. Four patients (9%) (2 patients from each group) required blood transfusion. There were no significant between-group differences in blood loss and blood transfusion requirements. All 7 patients with hypervascular tumors were in the embolization (+) group. Two patients experienced muscle weakness in the lower extremities on days 1 and 3 after embolization. There were metastases in T5 and T1-2, and magnetic resonance imaging after embolization showed slight exacerbation of spinal cord compression. The patients showed partial recovery after surgery. Conclusions: With the predominance of hypervascular tumors in the embolization (+) group, preoperative embolization may positively affect intraoperative bleeding. Embolization of metastatic spinal tumors may pose a risk of paralysis. Although the cause of paralysis remains unclear, it might be due to the aggravation of spinal cord compression. Considering this risk of paralysis, we advocate performing surgery as soon as possible after embolization.

Association between sagittal spinopelvic alignment and femoral head destruction in the early stage of rapidly destructive coxopathy.

AIMS: This study aimed to evaluate sagittal spinopelvic alignment (SSPA) in the early stage of rapidly destructive coxopathy (RDC) compared with hip osteoarthritis (HOA), and to identify risk factors of SSPA for destruction of the femoral head within 12 months after the disease onset. METHODS: This study enrolled 34 RDC patients with joint space narrowing > 2 mm within 12 months after the onset of hip pain and 25 HOA patients showing femoral head destruction. Sharp angle was measured for acetabular coverage evaluation. Femoral head collapse ratio was calculated for assessment of the extent of femoral head collapse by RDC. The following parameters of SSPA were evaluated using the whole spinopelvic radiograph: pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), sagittal vertical axis (SVA), thoracic kyphosis angle (TK), lumbar lordosis angle (LL), and PI-LL. RESULTS: The HOA group showed higher Sharp angles compared with the RDC group. PT and PI-LL were higher in the RDC group than the HOA group. SS and LL were lower in the RDC group than the HOA group. No difference was found in PI, SVA, or TK between the groups. Femoral head collapse ratio was associated with PT, SS, SVA, LL, and PI-LL. A PI-LL > 20° and a PT > 30° correlated with greater extent of femoral head destruction by RDC. From regression analysis, SS and SVA were significantly associated with the femoral head collapse ratio within 12 months after disease onset. CONCLUSION: Compared with HOA, RDC in the early stage correlated with sagittal spinopelvic malalignment. SS and SVA may partially contribute to the extent of femoral head destruction by RDC within 12 months after the onset of hip pain. The present study indicates a potential role of SSPA assessment in identification of RDC patients at risk for subsequent bone destruction. Cite this article: Bone Jt Open 2022;3(1):77-84.

Activation of STAT3 (signal transducer and activator of transcription 3) in synovial tissues from the hip joint in the early stage of rapidly destructive coxopathy.

Interleukin-6 signaling activates signal transducer and activator of transcription 3 (STAT3), resulting in matrix metalloproteinase-3 (MMP-3) production. The hip joints with rapidly destructive coxopathy (RDC) show rapid chondrolysis, probably by increased MMP-3. This study aimed to elucidate STAT3 activation in the synovial tissues with joint destruction in the early stage of RDC. Synovial tissues within 7 months from the disease onset were obtained from four RDC patients with femoral head destruction and high serum levels of MMP-3. RDC synovial tissues demonstrated the synovial lining hyperplasia with an increase of CD68-positive macrophages and CD3-positive T lymphocytes. STAT3 activation was found in the synovial tissues by immunohistochemistry using anti-phospho-STAT3 antibody. The majority of phospho-STAT3-positive cells were the synovial lining cells and exhibited negative expression of the macrophage or T cell marker. Treatment with CP690,550, a Janus Kinase inhibitor, resulted in a decrease in phospho-STAT3-positive cells, especially with high intensity, indicating effective suppression of STAT3 activation in RDC synovial tissues. Inhibitory effect of CP690,550 could work through the Janus Kinase/STAT3 axis in the synovial tissues in the early stage of RDC. Thus, STAT3 may be a potential therapeutic target for prevention of joint structural damage in RDC.