Three-Dimensional Analysis of the Ideal Entry Point for Sacral Alar Iliac Screws

Methods@#Preoperative CT data from 26 patients pertaining to adult spinal deformities were investigated in this study. We applied a 3D image processing method for a detailed investigation. Virtual cylinders were used to mimic SAI screws. These were placed to penetrate the sacral iliac joint without violating the other cortex. We then assessed the trajectory of the longest SAI screw and the ideal entry point of SAI using a color mapping method on the surface of the sacrum. We measured the location of the nerve root at S1 in relation to the foramen at S1 and the sacral surface. @*Results@#As per the results of our color mapping, it was determined that areas that received high scores are located medially and caudally to the dorsal foramen of S1. The mean angle between a horizontal line and a line connecting the medial edge of the foramen and nerve root at S1 was 93.5°. The mean distances from the dorsal medial edge of the foramen and sacral surface to S1 nerve root were 21.8 mm and 13.9 mm, respectively. @*Conclusions@#The ideal entry point of the SAI screw is located medially and caudally to the S1 dorsal foramen based on 3D digital mapping. It is also shown that this entry point spares the S1 nerve root from possible iatrogenic injuries.

The accuracy of a newly developed guide system in medial meniscus posterior root repair: a comparison between two aiming guides

PURPOSE@#Posterior root repair of the medial meniscus (MM) can prevent rapid progression of knee osteoarthritis in patients with a MM posterior root tear (MMPRT). The anatomic reattachment of the MM posterior root is considered to be critical in a transtibial pullout repair. However, tibial tunnel creation at the anatomic attachment is technically difficult. We hypothesized that a newly developed point-contact aiming guide [Unicorn Meniscal Root (UMR) guide] can create the tibial tunnel at a better position rather than a previously designed MMPRT guide. The aim of this study was to compare the position of the created tibial tunnel between the two meniscal root repair guides.@*MATERIALS AND METHODS@#Thirty-eight patients underwent transtibial pullout repairs. Tibial tunnel creation was performed using the UMR guide (19 cases) or MMPRT guide (19 cases). Three-dimensional computed tomography images of the tibial surface were evaluated using the Tsukada's measurement method postoperatively. The expected anatomic center of the MM posterior root attachment was defined as the center of three tangential lines referring to three anatomic bony landmarks (anterior border of the posterior cruciate ligament, lateral margin of the medial tibial plateau, and retro-eminence ridge). The expected anatomic center and tibial tunnel center were evaluated using the percentage-based posterolateral location on the tibial surface. The distance between the anatomic center and tunnel center was calculated.@*RESULTS@#The anatomic center of the MM posterior root footprint was located at a position of 79.2% posterior and 39.5% lateral. The mean of the tunnel center in the UMR guide was similar to that in the MMPRT guide (posterior direction, P = 0.096; lateral direction, P = 0.280). The mean distances between the tunnel center and the anatomic center were 4.06 and 3.99mm in the UMR and MMPRT guide group, respectively (P = 0.455).@*CONCLUSIONS@#The UMR guide, as well as the MMPRT guide, is a useful device to create favorable tibial tunnels at the MM posterior root attachment for pullout repairs in patients with MMPRTs.LEVEL OF EVIDENCE: IV

Preliminary diagnosis of medial meniscus posterior root tears using the Rosenberg radiographic view

PURPOSE@#To verify the effectiveness of detecting medial meniscus posterior root tears (MMPRTs) using weight-bearing posterior-anterior (PA) radiographs.@*MATERIALS AND METHODS@#Twenty-three patients were diagnosed with an MMPRT using magnetic resonance imaging (Group A), with 23 matched individuals forming the control group (Group B). The distance between medial tibial eminence and the lateral edge of the medial femoral condyle (MTE–MFC distance) and medial joint space (MJS) width were measured on weight-bearing PA radiographs, with the knee flexed at 45° (Rosenberg view). Absolute medial meniscus extrusion (MME) was measured on magnetic resonance images.@*RESULTS@#The MTE–MFC distance was greater and the MJS width was smaller in Group A than Group B (7.7 ± 1.7mm versus 6.0 ± 1.24mm and 3.2 ± 0.8mm versus 4.5 ± 0.7 mm, respectively; P < 0.05). The MTE–MFC distance and MJS width correlated with MME (r = 0.603 and 0.579, respectively; P < 0.05), and the extent of MME was greater in Group A than Group B (4.1 ± 1.1mm versus 1.8 ± 1.5 mm, respectively; P < 0.05).@*CONCLUSIONS@#MMPRTs increase the MTE–MFC distance and decrease the MJS width, with these measurements correlating to the MME. Therefore, measurement of the MTE–MFC distance and MJS width on the Rosenberg view could be a useful preliminary method for the diagnosis of an MMPRT.LEVEL OF EVIDENCE: IV

Time-Dependent Increase in Medial Meniscus Extrusion after Medial Meniscus Posterior Root Tear Analyzed by Using Magnetic Resonance Imaging

PURPOSE: Medial meniscus posterior root tear (MMPRT) causes progression of medial meniscus extrusion (MME). This study aims to calculate the progression rate of MME based on findings in two preoperative magnetic resonance imaging (MRI) scans and determine the associated factors. MATERIALS AND METHODS: We retrospectively reviewed 33 patients (27 females and 6 males; mean age, 60 years) who underwent MRI twice, at a mean interval of 48 days. We measured the medial meniscus body width, medial joint space width (MJSW), and MME. The MME progression rate was derived from regression analysis of the increase in MME (ΔMME) between the two MRI scans. In addition, the correlations of the MME increase rate with age, body mass index, femorotibial angle, and MJSW were evaluated. RESULTS: The mean MME increased from 3.4 mm to 4.5 mm (p<0.001). A good correlation was observed between ΔMME and the interval of MRI scans (R²=0.621), and the MME progression rate was 0.020 mm per day. A moderate correlation was observed between the MME increase rate and the MJSW (R²=0.432). CONCLUSIONS: The MME progression rate was rapid in MMPRT and narrowing of the MJSW was associated with the progression of MME. LEVEL OF EVIDENCE: V, Cross-sectional study

Relationship between Displacement of the Psoas Major Muscle and Spinal Alignment in Patients with Adult Spinal Deformity

STUDY DESIGN: Cross sectional study. PURPOSE: To clarify the difference in position of the psoas muscle between adult spinal deformity (ASD) and lumbar spinal stenosis (LSS). OVERVIEW OF LITERATURE: Although it is known that the psoas major muscle deviates in ASD patients, no report is available regarding the difference in comparison with LSS patients. METHODS: This study investigates 39 patients. For evaluating spinal alignment, pelvic tilt (PT), pelvic incidence (PI), sacral slope, lumbar lordosis (LL), PI–LL, Cobb angle, and the convex side, the lumbar curves were measured. For measuring the position of the psoas major at the L4/5 disk level, magnetic resonance imaging was used. The displacements of psoas major muscle were measured separately in the anterior–posterior and lateral directions. We examined the relationship between the radiographic parameters and anterior displacement (AD) and lateral displacement (LD) of the psoas major muscle. RESULTS: AD was demonstrated in 15 cases with ASD and nine cases with LSS (p>0.05). LD was observed in 13 cases with ASD and no cases with LSS (p < 0.01). The Cobb angle was significantly greater in cases with AD than in those without AD (p=0.04). PT, LL, PI–LL, and Cobb angle were significantly greater in cases with LD (p < 0.05). All cases with LD had AD, but no case without AD had LD (p < 0.001). The side of greater displacement at L4/5 and the convex side of the lumbar curve were consistent in all cases. CONCLUSIONS: Despite AD being observed in LSS as well, LD was observed only in the ASD group. Radiographic parameters were worse when LD was seen, rather than AD.

Minimal Ablation of the Tibial Stump Using Bony Landmarks Improved Stability and Synovial Coverage Following Double-Bundle Anterior Cruciate Ligament Reconstruction

PURPOSE: To evaluate the clinical effects of using anatomical bony landmarks (Parsons' knob and the medial intercondylar ridge) and minimal ablation of the tibial footprint to improve knee anterior instability and synovial graft coverage after double-bundle anterior cruciate ligament reconstruction. MATERIALS AND METHODS: We performed a retrospective comparison of outcomes between patients who underwent reconstruction with minimal ablation of the tibial footprint, using an anatomical tibial bony landmark technique, and those who underwent reconstruction with wide ablation of the tibial footprint. Differences between the two groups were evaluated using second-look arthroscopy, radiological assessment of the tunnel position, postoperative anterior knee joint laxity, and clinical outcomes. RESULTS: Use of the anatomical reference and minimal ablation of the tibial footprint resulted in a more anterior positioning of the tibial tunnel, with greater synovial coverage of the graft postoperatively (p=0.01), and improved anterior stability of the knee on second-look arthroscopy. Both groups had comparable clinical outcomes. CONCLUSIONS: Use of anatomical tibial bony landmarks that resulted in a more anteromedial tibial tunnel position improved anterior knee laxity, and minimal ablation improved synovial coverage of the graft; however, it did not significantly improve subjective and functional short-term outcomes.

Calcar Femorale in Patients with Osteoarthritis of the Hip Secondary to Developmental Dysplasia

BACKGROUND: We investigated whether the calcar femorale, a cortical septum in the region of the lesser trochanter of the femur, correlates with results of femoral stem implantation in patients with osteoarthritis of the hip secondary to developmental dysplasia using computed tomography. METHODS: This retrospective study included 277 hips (41 males and 236 females; age, 37 to 92 years) of patients who had presented to Okayama Medical Center with hip pain. Of these, a total of 219 hips (31 males and 188 females) had previously undergone total hip arthroplasty. According to the Crowe classification, 147 hips were classified as Crowe grade I, 72 hips as Crowe grade II–IV, and 58 hips as normal. RESULTS: The calcar femorale was identified in 267 hips (96.4%). The calcar femorale was significantly shorter and more anteverted in Crowe grade II–IV hips than in Crowe grade I or normal hips. Significant differences in the shape of the calcar femorale were found according to the severity of hip deformity. Three stem designs were analyzed: single-wedge (59 hips), double-wedge metaphyseal filling (147 hips), and modular (13 hips). Single-wedge stems were inserted more parallel to the calcar femorale rather than femoral neck anteversion, while other types of stems scraped the calcar femorale. CONCLUSIONS: The angle of the calcar femorale differs according to the severity of hip deformity, and the calcar femorale might thus serve as a more useful reference for stem insertion than femoral neck anteversion in total hip arthroplasty using a single-wedge stem.

Discrimination between Malignant and Benign Vertebral Fractures Using Magnetic Resonance Imaging

STUDY DESIGN: Retrospective analysis using magnetic resonance imaging (MRI). PURPOSE: To identify MRI features that could discriminate benign from malignant vertebral fractures. OVERVIEW OF LITERATURE: Discrimination between benign and malignant vertebral fractures remains challenging, particularly in patients with osteoporosis and cancer. Presently, the most sensitive means of detecting and assessing fracture etiology is MRI. However, published reports have focused on only one or a few discriminators. METHODS: Totally, 106 patients were assessed by MRI within six weeks of sustaining 114 thoracic and/or lumbar vertebral fractures (benign, n=65; malignant, n=49). The fractures were pathologically confirmed if malignant or clinically diagnosed if benign and were followed up for a minimum of six months. Seventeen features were analyzed in all fractures' magnetic resonance images. Single parameters were analyzed using the chi-square test; a logit model was established using multivariate logistic regression analysis. RESULTS: The chi-square test revealed 11 malignant and 4 benign parameters. Multivariate logistic regression analysis selected (i) posterior wall diffuse protrusion (odds ratio [OR], 48; 95% confidence interval [CI], 4.2–548; p=0.002), (ii) pedicle involvement (OR, 21; 95% CI, 2.0–229; p=0.01), (iii) posterior involvement (OR, 21; 95% CI, 1.5–21; p=0.02), and (iv) band pattern (OR, 0.047; 95% CI, 0.0005–4.7; p=0.19). The logit model was expressed as P=1/[1+exp (x)], x=−3.88×(i)−3.05×(ii)−3.02×(iii)+3.05×(iv)+5.00, where P is the probability of malignancy. The total predictive value was 97.3%. The only exception was multiple myeloma with features of a benign fracture. CONCLUSIONS: Although each MRI feature had a different meaning with a variable differentiation power, combining them led to an accurate diagnosis. This study identified the most relevant MRI features that would be helpful in discriminating benign from malignant vertebral fractures.

Meniscal Extrusion Progresses Shortly after the Medial Meniscus Posterior Root Tear

PURPOSE: Medial meniscus posterior root tears (MMPRT) induce medial meniscus extrusion (MME). However, the time-dependent extent of MME in patients suffering from the MMPRT remains unclear. This study evaluated the extent of MME after painful popping events that occurred at the onset of the MMPRT. MATERIALS AND METHODS: Thirty-five patients who had an episode of posteromedial painful popping were investigated. All the patients were diagnosed as having an MMPRT by magnetic resonance imaging (MRI) within 12 months after painful popping. Medial meniscus body width (MMBW), absolute MME, and relative MME (100×absolute MME/MMBW) were assessed among three groups divided according to the time after painful popping events: early period ( < 1 month), subacute period (1–3 months), and chronic period (4–12 months). RESULTS: In the early period, absolute and relative MMEs were 3.0 mm and 32.7%, respectively. Absolute MME increased up to 4.2 mm and 5.8 mm during the subacute and chronic periods, respectively. Relative MME also progressed to 49.2% and 60.3% in the subacute and chronic periods, respectively. CONCLUSIONS: This study demonstrated that absolute and relative MMEs increased progressively within the short period after the onset of symptomatic MMPRT. Our results suggest that early diagnosis of an MMPRT may be important to prevent progression of MME following the MMPRT.

Impact of Rotation Correction after Brace Treatment on Prognosis in Adolescent Idiopathic Scoliosis

STUDY DESIGN: Level 4 retrospective review. PURPOSE: Brace treatment is the standard nonoperative treatment for adolescent idiopathic scoliosis (AIS). Rotation correction is also important, because AIS involves a rotation deformity. The purpose of this study was to evaluate the impact of rotation correction after Osaka Medical College (OMC) brace treatment on clinical outcomes in AIS. OVERVIEW OF LITERATURE: Brace treatment has a significant effect on the progression of AIS. However, few reports have examined rotation correction after brace treatment. METHODS: A total of 46 patients who wore the OMC brace were retrospectively reviewed. The curve magnitude was determined according to the Cobb method, and the rotation angle of the apical vertebrae was measured by the modified Nash-Moe method. Based on the difference in the rotation angle before and after the initial brace treatment, patients were divided into two groups. Group A (n=33) was defined as no change or improvement of the rotation angle; group B (n=13) was defined as deterioration of the rotation angle. If the patients had curve or rotation progression of 5° or more at skeletal maturity, or had undergone surgery, the treatment was considered a failure. RESULTS: Differences of rotation angle between before and after the initial brace treatment were 2°±2° in group A and –3°±2° in group B (p<0.001). The rates of treatment failure were 42% in group A and 77% in group B (p<0.05). This study included 25 patients with Lenke type 1 (54%). Group A (24%) with Lenke type 1 also had a significantly better success rate of brace treatment than group B (75%) (p<0.05). CONCLUSIONS: Insufficient rotation correction increased brace treatment failure. Better rotation correction resulted in a higher success rate of brace treatment in patients with Lenke type 1.

A Pilot Study of the Physical Characteristics and Thermal Effects of Mud compared with Bentonite / The Japanese Journal of Rehabilitation Medicine

Design : A pilot, comparative study was conducted. Background : Heat wraps using bentonite (HWb) are commonly used in thermotherapy. In the Okayama University Misasa Medical Center, heat wraps using mud (HWm) produced by mixing soil with boiling water have also been used. The subjective thermal effects of HWm on patients with osteoarthritis of the knee have been reported. However, the objective thermal effects of HWm have not been examined. As such, the physicochemical thermal effects of HWm were analyzed and compared with those of HMb. Methods : The thermal effects of HWm and HWb were investigated regarding heat radiation, conduction, capacity and moisture content. Heat radiation and conduction were measured by changes in temperature of the heat wraps, in addition heat conduction was also assessed by blood flow in body surfaces (<i>N</i>=7). Heat capacity and moisture content were measured with a Differential Scanning Calorimeter. Results: Heat radiation and heat conduction of HWm were significantly greater than those of HWb (<i>p</i><0.001). The specific heat capacity of HWm was 2.0 J/g/°C, and was 1.7 J/g/°C for HWb. Moisture content of HWm and HWb were 0.6 mg/g and 0.3 mg/g, respectively. Conclusion : Heat radiation, conduction and capacity of HWm are superior to those of HWb. Moreover, the moisture content in HWm is greater than that of HWb. These results indicate that the thermal effects of HWm would have more be physicochemical usefulness.