Transforaminal Lumbar Interbody Fusion with Double Banana Cages: Clinical Evaluations and Finite Element Model Analysis.

STUDY DESIGN: Clinical and basic study. OBJECTIVES: This study aimed to investigate whether transforaminal lumbar interbody fusion (TLIF) using 2 banana-shaped cages leads to good clinical outcomes. METHODS: First, we conducted a clinical study to compare outcomes among patients who underwent TLIF using different types or numbers of cages. Propensity matched patients in each group were reviewed. Thirty-four patients who underwent surgery with 2 bullet-shaped cages (group A), 34 with a banana-shaped cage (group B), and 34 with 2 banana-shaped cages (group C) were compared. Twelve months after the surgery, bony fusion and cage subsidence were evaluated. RESULTS: The mean amount of cage subsidence was 14.9% in group A, 19.9% in group B, and 11.8% in group C. Subsidence in group B was significantly greater than that in group C (P < .01). Radiological bony fusion was not achieved in 2 cases in group B. Second, we performed a finite element model (FEM) analysis to determine the biomechanical stress of the vertebral endplate by comparing the single-banana cage construct with a double banana-shaped cage construct. FEM analysis showed that the maximum stress of the endplate in the single-cage model was 1.72-times greater than the maximum stress in the double-cage model. Furthermore, the maximal stress in the single-cage model was significantly higher than in the double-cage model during lumbar extension and side bending. CONCLUSION: This study showed that TLIF with double banana-shaped cages led to good clinical outcomes with less cage subsidence, probably because of decreased mechanical stress on the vertebral endplate.

Reduced dynamic loads due to hip dislocation induce acetabular cartilage degeneration by IL-6 and MMP3 via the STAT3/periostin/NF-κB axis.

Developmental dysplasia of the hip (DDH) is characterized by anatomical abnormalities of the hip joint, ranging from mild acetabular dysplasia to hip subluxation and eventually dislocation. The mechanism underlying the cartilage degeneration of the hip joints exposed to reduced dynamic loads due to hip dislocation remains unknown. We established a rodent hip dislocation (disarticulation; DA) model of DDH (DA-DDH rats and mice) by swaddling. Expression levels of periostin (Postn) and catabolic factors, such as interleukin-6 (IL-6) and matrix metalloproteinase 3 (Mmp3), increased and those of chondrogenic markers decreased in the acetabular cartilage of the DA-DDH models. Postn induced IL-6 and Mmp3 expression in chondrocytes through integrin αVß3, focal adhesion kinase, Src, and nuclear factor-κB (NF-κB) signaling. The microgravity environment created by a random positioning machine induced Postn expression in chondrocytes through signal transducer and activator of transcription 3 (STAT3) signaling. IL-6 stimulated Postn expression via STAT3 signaling. Furthermore, cartilage degeneration was suppressed in the acetabulum of Postn-/- DA-DDH mice compared with that in the acetabulum of wild type DA-DDH mice. In summary, reduced dynamic loads due to hip dislocation induced acetabular cartilage degeneration via IL-6 and MMP3 through STAT3/periostin/NF-κB signaling in the rodent DA-DDH models.

Surgical Management of Thoracolumbar Scoliosis Secondary to Hip Joint Ankylosis and Severe Pelvic Obliquity.

We report a rare case of a rigid spinal deformity with severe pelvic obliquity (PO) resulting from hip ankylosis caused by childhood tuberculosis (TB). A 66-year-old woman presented with left knee pain, chronic low back pain, and fatigability during walking. She presented with leg length discrepancy (LLD) due to an ankylosed right hip joint, severe PO, and secondary lumbar scoliosis. Total hip arthroplasty (THA) and adductor tendonectomy were performed prior to spine surgery, and posterior spinal correction and fusion were performed from T10 to the pelvis. Prior to spinal correction surgery, we predicted that it would be impossible to make the pelvis perfectly horizontal. Therefore, we positioned a prosthetic acetabular cup at a small inclination angle at the upper limit of anteversion; spinal correction and fusion were then performed. Her symptoms including fatigability during walking resolved and the sagittal spinal balance on standing improved dramatically. The preoperative and postoperative values of the thoracolumbar Cobb angle was 40° and 25°, lumbosacral Cobb angle was 60° and 14°, C7 plumb line shift was 24 and 0 mm, pelvic tilt was 15° and 19°, lumbar lordosis (LL) was 23° and 60°, pelvic incidence minus lumbar lordosis (PI-LL) was 38° and 1°, the sagittal vertical axis was 80 and 0 mm, and PO was 28° and 15°, respectively. We present a case of rigid spinal deformity accompanied by hip joint ankylosis and PO. Performing THA prior to spinal correction surgery is an alternative and feasible option for the treatment of this challenging pathology.

Total hip arthroplasty using a three-dimensional porous titanium acetabular cup: an examination of micromotion using subject-specific finite element analysis.

BACKGROUND: We investigated the mid-term clinical and radiological results of total hip arthroplasty (THA) using a three-dimensional (3D) porous titanium cup and analyzed the micromotion at the interface of the cup using subject-specific finite element (FE) analysis. METHODS: We evaluated 73 hips of 65 patients (6 men and 59 women; mean age at the time of surgery, 62.2 years; range, 45-86 years) who had undergone THA using a 3D porous titanium cup. Clinical evaluations were performed using the Japanese Orthopaedic Association (JOA) hip score system. We assessed the fixation of the acetabular component based on the presence of radiolucent lines and cup migration using anteroposterior radiographs. Subject-specific FE models were constructed from computed tomography data. RESULTS: The JOA score improved from a preoperative mean of 52.2 (range, 23-82) to a mean of 87.8 (range, 71-100) at the final follow-up. None of the patients underwent revisions during the follow-up period. Radiolucent lines were observed in 26 cases (35.6%) and frequently appeared at DeLee and Charnley Zone 3. Following the FE analysis, the micromotion at DeLee and Charnley Zone 3 was significantly larger than that at Zone 2. Furthermore, micromotion was large in the groups in which radiolucent lines appeared at Zone 3. CONCLUSIONS: The mid-term clinical outcome of THA using a 3D porous titanium cup was excellent. However, radiolucent lines frequently appeared at DeLee and Charnley Zone 3. FE analysis indicated that micromotion was large at the same site, strongly suggesting that it contributes to the emergence of radiolucent lines. The 3D porous titanium cups are useful in THA, and with improvements focused on micromotion, we anticipate better long-term outcomes.

Intracranial subarachnoid hemorrhage following cervical laminoplasty: a report of two cases.

Intracranial hemorrhage is a rare complication of spinal surgery. Case 1 was a 58-year-old man who underwent cervical laminoplasty. No apparent iatrogenic dural rupture or cerebrospinal fluid leakage was observed. An hour after the surgery, the patient had convulsions and became restless thereafter. CT revealed an intracranial subarachnoid hemorrhage (SAH). The patient recovered normal consciousness the next morning. Case 2 was a 68-year-old woman who underwent cervical laminoplasty without postoperative cerebrospinal fluid leakage. Six days after the surgery, the patient continued to complain of nausea and headache. By 13 days, the patient reported relief from her symptoms. There was no evidence of cerebral aneurysm, or vascular malformation in both cases. Patients undergoing cervical laminoplasty might be at risk for developing SAH. Careful attention to intraoperative neck positioning, strict monitoring and control of perioperative blood pressure, and complete dural repair are essential measures for preventing SAH.

Magnetic Resonance Imaging Findings Following Ceramic-on-Ceramic Total Hip Arthroplasty Using Modular Neck Femoral Components.

BACKGROUND: Adverse reactions to metal debris after total hip arthroplasty are an increasing concern. Metal debris is released from the metal-on-metal articulation itself as well as from the head-neck taper. There is also a risk of corrosion at the neck-stem junction. Some stems were recalled because of high revision rates as a result of metal debris from the modular junction. We conducted a retrospective analysis of the 3-year to 8-year clinical and radiographic outcomes of a consecutive cohort of patients who underwent cementless total hip arthroplasty using a modular hip prosthesis with ceramic-on-ceramic bearings. METHODS: We retrospectively evaluated 104 patients who had undergone 119 primary ceramic-on-ceramic total hip arthroplasties using modular neck femoral components between December 2006 and November 2012. All hips were implanted with a titanium alloy stem and titanium alloy neck. Clinical outcomes were evaluated using the Japanese Orthopaedic Association hip score. Prosthesis survival was calculated according to the Kaplan-Meier method considering any reason for revision as failure. Postoperative magnetic resonance imaging was performed and graded using a previously described pseudotumor grading system. Mean follow-up was 5.9 years (range: 3 to 8 years). RESULTS: The mean age of the patients at the time of the index arthroplasty was 59.0 years. Mean hip score improved from 45.9 (range: 9 to 90) preoperatively to 91.5 (range: 65 to 100) at the final follow-up. The overall implant survival rate was 97.3% at 8 years when revision for any reason was used as the endpoint. Abnormalities on magnetic resonance imaging were seen in 16 of 91 hips (17.6%). All abnormalities were cystic thin-walled lesions located in the peritrochanteric area. There was no revision operation due to adverse reactions to metal debris. CONCLUSIONS: A modular neck femoral prosthesis with ceramic-on-ceramic bearings offers satisfactory 3-year to 8-year results. However, abnormalities on magnetic resonance imaging were seen in one-fifth of the patients, although the clinical significance is unknown.