Sigmoid Notch Research Articles

Usefulness of the Retromandibular Transparotid Approach for Condylar Neck and Condylar Base Fractures

Condyle fractures represent 20% to 30% of all mandibular fractures and are thus among the most common facial fractures. The fracture pattern can vary greatly and may occur anywhere along the line from the sigmoid notch to the mandibular angle. The main problems are access, difficulty in repositioning the extremely slender fragments, and fixation of the condyle.Eighty-seven patients were diagnosed with condylar neck or condylar base fractures from January 2007 to December 2009 in the Department of Oral & Maxillofacial Surgery of Kyung Hee University Dental Hospital. In this study, we included 35 patients who underwent open surgery and a total of 28 patients who were treated using a retromandibular transparotid approach.Surgical treatment aims were anatomic repositioning and rigid fixation of the fragments, occlusal stability, rapidly return to function, maintenance of vertical ramus dimension, no airway compromise, and reduced long-term temporomandibular joint dysfunction. Considering the high rate of occurrence of condylar fracture and the importance of the condylar as a growth center of the mandible, extraoral approaches for the open reduction of condylar fractures are considered effective and can be used widely.Short access route, easy reduction, short operating time, and stable postoperative occlusion are the advantages of the retromandibular transparotid approach. Also, there was no permanent damage from facial nerve injury, salivary leakage, or preauricular hypoesthesia. Therefore, the retromandibular transparotid approach is considered a safe and effective method for patients with a condylar neck or condylar base fracture classified according to the Strasbourg Osteosynthesis Research Group's classification, who require surgical treatment with an extraoral approach.

Distal Humeral Fracture Fixation with an Extensor Mechanism-on Approach.

Open treatment of extra-articular and intra-articular distal humeral fractures can be effectively accomplished through an extensor mechanism-on approach. Assess all images for multiplane fracture lines involving the capitellum or trochlea. Verify with fluoroscopy that the patient and arm positions allow for adequate imaging of the distal part of the humerus. Perform medial and lateral arthrotomies posterior to the collateral ligament complexes and excise the intra-articular fat pad and posterior aspect of the capsule. Reduce the distal humeral fragments anatomically under direct visualization posteriorly and indirectly with fluoroscopy using the intact sigmoid notch as a template for reduction. Place multiple screws distally through the plates medially and laterally; each screw should be of maximal length and engage the opposite column. Remove the dressing on postoperative day two and begin full active-assisted elbow range of motion and grip-strengthening therapy program. In our series of thirty-seven patients12, all fractures healed primarily with a median motion arc of 126° (range, 60° to 141°). The median triceps strength loss was 10% (range, 0% to 49%). IndicationsContraindicationsPitfalls & Challenges.

Intra-articular osteoid osteoma in the proximal ulna combined with radial head subluxation: a case report

Osteoid osteoma is a relatively common benign bone tumor that was first described by Jaffe in 1935. Its typical clinical feature is pain, which is worse at night and relieved by nonsteroidal anti-inflammatory drugs (NSAIDs). Typical radiologic findings are a nidus with a small radiolucent area within an extensive reactive cortical thickening. This tumor has a predilection for the diaphysis or metaphysis of long bones, with 50-60% occurring in the femur or tibia. However, localization in the elbow is a very rare presentation, and shows an atypical picture that causes both diagnostic delay and therapeutic problems. We herein report a case of a 19-year-old man who had pain and limited motion of the left elbow as a result of osteoid osteoma at the sigmoid notch of the proximal ulna. Anterior subluxation of the radial head was also observed by simple radiographs. En bloc resection and synovectomy resulted in pain relief, motion recovery, and reduction of the subluxated radial head. The patient consented when asked if data concerning his case could be submitted for publication.

Intraoperative Imaging of the Distal Radioulnar Joint Using a Modified Skyline View

Nonanatomic reduction of the sigmoid notch in distal radius fractures may lead to limited motion, instability, or pain with pronation and supination. Standard radiological projections only poorly capture the sigmoid notch contours in the axial plane. The purpose of this study was to find an intraoperatively feasible radiological projection that will facilitate an axial view of the distal radioulnar joint. We modified a previously described radiographic projection termed the skyline view for evaluating the distal radius axially. We created intra-articular steps at the sigmoid notch in solid foam forearm models to identify the best of 12 projections using an image intensifier. Four observers scored each projection based on the clarity of the sigmoid notch contour and indicated the presence and location of an intra-articular stepoff. The sigmoid notch was best visualized in the modified skyline view with the wrist in extension and 10° to 15° of dorsal forearm angulation relative to the x-ray path. All observers correctly recognized the presence and location of intra-articular steps at the sigmoid notch with this view. The same forearm angulation with the wrist in flexion did not reach equally good visibility of the sigmoid notch. Arm position (wrist flexion, forearm rotation, or forearm angulation) and intra-articular stepoff (none, palmar, or dorsal) were dependent determinates. Elimination of the variable forearm rotation had minimal effect, indicating that forearm rotation is not important for visualization of the sigmoid notch. The modified skyline view for visualization of the distal radioulnar joint in an axial plane allows good visibility of the sigmoid notch and reliable identification of stepoffs. Further cadaver and in vivo studies are required to verify the validity of this method.

Sigmoid Notch Reconstruction and Limited Carpal Arthrodesis for a Severely Comminuted Distal Radius Malunion: Case Report

We present the case of a young patient with a severely comminuted, malunited, intra-articular distal radius fracture and complete disruption of the sigmoid notch. We reconstructed the malunited distal radioulnar joint by osteotomy and repositioning the displaced sigmoid notch fragments through a combined dorsal and volar approach. At the same time, we carried out a radioscapholunate arthrodesis with distal scaphoid excision. We used a free vascularized corticoperiosteal flap from the medial femoral condyle to span the massive bone defect in the radius to obtain union. At the 2.5-year follow-up, the patient had essentially normal function of the distal radioulnar joint (painless, with 85° of active pronation and 75° of supination). He resumed work as a bricklayer without limitations. We conclude that sigmoid notch reconstruction by osteotomy is worthwhile in the setting of malunited distal radius whether or not the radiocarpal joint is reconstructable.

Evaluation of diffusion parameters and T2 values of the masseter muscle during jaw opening, clenching, and rest

Diffusion-weighted imaging (DWI) and diffusion-tensor imaging (DTI) can be used to evaluate changes that accompany skeletal muscle contraction. To investigate whether jaw opening or closure affect the diffusion parameters of the masseter muscles (MMs). Eleven healthy volunteers were evaluated. Diffusion-tensor images were acquired to obtain the primary (λ(1)), secondary (λ(2)), and tertiary eigenvalues (λ(3)). We estimated these parameters at three different locations: at the level of the mandibular notch for the superior site, the level of the mandibular foramen for the middle site, and the root apex of the mandibular molars for the inferior site. Both λ(2) and λ(3) during jaw opening were significantly lower than that at rest at the superior (P = 0.006, P < 0.0001, respectively) and middle site (P = 0.004, P = 0.0001, respectively); however, the change in λ(1) was not significant. At the lower site, no parameter was significantly different at rest and during jaw opening. There was no significant difference in T2 between at rest (40.3 ± 4.4 ms) and during jaw opening (39.2 ± 2.7 ms; P = 0.12). The changes induced by jaw closure were marked at the inferior site. In the middle and inferior sites, the three eigenvalues were increased by jaw closure, and the changes in λ(1) (P = 0.0145, P = 0.0107, respectively) and λ(2) (P = 0.0003, P = 0.0001) were significant (especially λ(2)). The eigenvalues for diffusion of the MM were sensitive to jaw position. The recruitment of muscle fibers, specific to jaw position, reflects the differences in changes in muscle diffusion parameters.

Morphology of the Distal Radius in Extant Hominoids and Fossil Hominins: Implications for the Evolution of Bipedalism

One of the long-standing arguments about the evolution of bipedality centers on the locomotor pattern used by the last common ancestor (LCA) of apes and humans. In particular, knuckle-walking has been suggested as this locomotor pattern on the basis of shared morphology in the upper limb between African apes and humans and phylogenetic parsimony. Using three-dimensional geometric morphometrics, this study tests whether the distal radius of extant hominoids is sufficient for determining locomotor pattern and the affiliations of Plio-Pleistocene hominins to the extant taxa. Results indicate that while the entire radius differentiates the extant taxa very well by locomotor pattern, the distal radius fails to clearly differentiate the extant taxa. The sigmoid notch of the distal radius is the anatomical feature that differs most among the extant taxa, and its variability broadly correlates with necessary mobility at the wrist joint. Principal components and discriminant function analyses indicate that early hominins are affiliated with a variety of extant taxa with different locomotor patterns. Overall, the bony anatomy of the distal radius of early hominins points towards something adapted for a wide variety of locomotor postures.

Significance of localization of mandibular foramen in an inferior alveolar nerve block

Background:The mandibular foramen (MF) is an opening on the internal surface of the ramus for divisions of the mandibular vessels and nerve to pass. The aim of this study is to determine the position of the MF from various anatomical landmarks in several dry adult mandibles.Materials and Methods:A total of 102 human dry mandibles were examined, of which 93 were of dentulous and 9 were of edentulous. The measurements were taken from the anterior border of the ramus (coronoid notch) to the midportion of the MF and then from the midportion of the MF to the other landmarks such as internal oblique ridge, inferior border, sigmoid notch, and condyle were measured and recorded.Results:The data were compared using Student's t-test. The MF is positioned at a mean distance of 19 mm (with SD 2.34) from coronoid notch of the anterior border of the ramus. Superio-inferiorly from the condyle to the inferior border MF is situated 5 mm inferior to the midpoint of condyle to the inferior border distance (ramus height).Conclusion:We conclude that failures in the anesthesia of the inferior alveolar nerve are due to the operator error and not due to the anatomical variation.

下顎枝垂直骨切り術 －手術術式－

The use of Subcondylotomy procedure, the origin of Intraoral vertical osteotomy （IVRO）, has been limited by concerns of potential complications. These concern include condylar position and poor bone contact. Herbert and Nickerson modified the condylotomy procedure by converting it to variation of the IVRO and utilized maxillo-mandibular fixation and rehabilitation to minimize complication. Subsequent reports have confirmed that the IVRO also relieves pain and dysfunction a high percentage of time and, in addition, markedly reduces the complication. Today, IVRO has been using for the correction of Dentofacial Deformity in the world. Because of the primary advantage of this technique compared to the sagittal split osteotomy is the much less frequent and less severe damage to the mandibular nerve. However the protective surgical management was not performed, the potential for bleeding with a vertical oblique osteotomy has been reported to be greater than with the SSRO, because the superior aspect of the osteotomy is carried into the sigmoid notch. I will introduce the safety and ensuring technique of IVRO for correction of dentofacial deformity.

Orthodromic Temporalis Tendon Transfer

To define (1) at-risk structures during the orthodromic temporalis tendon transfer and (2) achievable tendon length without temporal releasing incisions or perioral lengthening materials. Ten fresh cadavers provided 20 hemifaces for dissection. Measurements and photographic documentation were used to examine the parotid duct, masseteric artery, inferior alveolar nerve, internal maxillary artery, and mobilized tendon relative to adjacent landmarks. The parotid duct was found in a reproducible region posterior to the melolabial crease and inferior to a parotid duct reference line. The masseteric artery was found posterior to the posterior-most attachment of the tendon at its exit from the sigmoid notch (mean, 14.5 mm). The inferior alveolar nerve was found posterior to the anterior edge of the ascending ramus (mean, 18.3 mm). The internal maxillary artery coursed superiorly from posterior to anterior along the medial mandible near the coronoidectomy site. The tendon reached beyond the melolabial crease in 17 of 20 hemifaces (85%). The parotid duct reference line and the melolabial crease allow estimation of the parotid duct location. Anatomical relationships between the tendon, parotid duct, neurovasculature, and anatomical landmarks underscore the importance of deliberate soft-tissue retraction and subperiostial elevation to minimize injury. The tendon alone usually provides adequate length for orthodromic suspension.

Morphological analysis of the lingula in dry adult human mandibles of north Indian population

Context: Lingula is a sharp tongue-shaped bony projection located on the medial aspect of mandibular ramus and knowledge regarding its shape, size, and location is clinically significant in oral and maxillofacial surgeries. Aim: The present study aims to study shape, height, and precise location of lingula in dry adult human mandibles. Materials and Methods: The material for this study comprised of sixty (120 sides) dry adult human mandibles of North Indian origin to determine the morphological features and location of lingula. Student's t -test was used for statistical analysis. Results: Triangular (61.6%) shape of lingula was most commonly found followed by truncated (46.6%), nodular (31.6%), and assimilated (11.6%) types. Each type of lingula was more often unilateral than bilateral. The mean height of the lingula was 5.5 ± 2.02 mm. The mean distance of lingula from the anterior and posterior borders of mandibular ramus was 20.0 ± 2.4 mm and 15.0 ± 2.7 mm, respectively. The lingula was located at 15.4 ± 2.7 mm from the mandibular notch and 30.4 ± 3.5 mm from the distal side of alveolar socket of mandibular second molar tooth. The mean lingula ratio was 0.567 ± 0.005. Conclusion: The information regarding shape, height, and precise location of lingula in relation to various mandibular ramal landmarks could be of immense help in performing surgical procedures such as bilateral sagittal split ramus osteotomy (BSSRO), intraoral ventral ramus osteotomy (IVRO), and inferior alveolar nerve block.

Evaluation of the Sigmoid Notch Involvement in the Intra-Articular Distal Radius Fractures: The Efficacy of Computed Tomography Compared with Plain X-ray

BackgroundThe purpose of this study is to evaluate the efficacy of computed tomography (CT) scans compared with plain radiographs on detecting the involvement of the sigmoid notch.MethodsThis study involved 121 cases diagnosed as the intra-articular distal radius fracture and performed post-reduction CT scans. We determined the presence of the sigmoid notch involvement with both plain radiographs and CT scans and compared findings of plain radiographs with CT scans about the incidence and the pattern of injuries. And the differences of results between arbeitsgemeinschaft für osteosyntheses (AO) type C2 and C3 were compared.ResultsThe incidences of sigmoid notch involvement detected in plain radiographs were 81 cases (66.9%), whereas CT scans were 99 cases (81.9%). The sensitivity of plain radiographs compared with CT scans was 74.7%, the specificity was 68.2%, the positive predictive value was 91.4%, the negative predictive value was 37.5%, the false negative value was 25.3%, and the false positive value was 31.8%. In comparison between AO type C2 and C3, the incidence of sigmoid notch involvement was not a significant difference, but the displacement of fracture fragment showed a significant difference.ConclusionsThe intra-articular distal radius fracture usually accompanies the sigmoid notch involvement. Considering that the evaluation of sigmoid notch involvement by plain radiography often results in misinterpretation or underestimation, performing CT scan in intra-articular distal radius fracture is thought to be beneficial.

An assessment of early mandibular growth

Quantification of skeletal data has been shown to be an effective and reliable method of demonstrating variation in human growth as well as for monitoring and interpreting growth. In South Africa as well as internationally, few researchers have assessed mandibular growth in late fetal period and early childhood and therefore standards for growth and age determination in these groups are limited. The purpose of this study was to evaluate growth in the mandible from the period of 31 gestational weeks to 36 months postnatal. A total of 74 mandibles were used. Dried mandibles were sourced from the Raymond A. Dart Collection (University of Witwatersrand), and cadaveric remains were obtained from the Universities of Pretoria and the Witwatersrand. The sample was divided into four groups; 31-40 gestational weeks (group 1), 0-11 months (group 2), 12-24 months (group 3), and 25-36 months (group 4). Twenty-one osteological landmarks were digitized using a MicroScribe G2. Ten standard measurements were created and included: the maximum length of mandible, mandibular body length and width, mandibular notch width and depth, mental foramen to inferior border of mandible, mandibular basilar widths bigonial and biantegonial, bigonial width of mental foramen and mental angle. Data were analyzed using PAST statistical software and Morphologika2 v2.5. Statistically significant differences were noted in the linear measurements for all group comparisons except between groups 3 and 4. The mandible morphologically changed from a round, smooth contour anteriorly to adopt a more sharp and narrow adult shape. A progressive increase in the depth and definition of the mandibular arch was also noted. In conclusion, the mandible initially grows to accommodate the developing tongue (up to 11 months), progressive dental eruption and mastication from 12 to 36 months. Mastication is associated with muscle mass development; this would necessitate an increase in the dimensions of the mandibular notch and associated muscle attachment sites. These findings might be valuable in the estimation of age in unidentified individuals and to monitor prenatal growth of the mandible for the early diagnosis of conditions associated with stunted mandibular growth.

Sur la reconstitution virtuelle du crâne du nouveau-né néandertalien Le Moustier 2. Implications ontogéniques.

Here we present a virtual skull reconstruction of the Le Moustier 2 neonate based on high-resolution computed tomographic data of the delicate original fragments. In the first step, the digital fragments were assembled based on anatomical criteria. If parts were missing on one side, or were better preserved on one side than the other, we used the software Avizo to reflect them across a midsagittal symmetry plane. Missing parts of the braincase were estimated based on complete reference crania using geometric morphometrics, so as to estimate endocranial volume (EV).When we compare our reconstruction of Le Moustier 2 to modern human neonates, we find that many morphological characteristics that separate Neandertal adults from modern human adults are already established at the time of birth. Neandertal features can already be detected in the shape of the orbit, the projection of the midface, the relative size and shape of the nose, the nasal bones, and the shape of the mandibular notch. The shape differences between Le Moustier 2 and modern human neonates in the cranial base are extremely subtle. Around the time of birth modern humans and Neandertals have very similar endocranial shapes and volumes. Our EV estimates for Le Moustier 2 range between 408–428 cc.Our reconstruction of Le Moustier 2 shows that most facial differences between modern humans and Neandertals develop prenatally as they are already established at the time of birth. Most shape differences in the braincase between modern humans and Neandertals, however, develop after birth. Our reconstruction of Le Moustier 2 therefore supports the notion that modern humans and Neandertals reach similar adult endocranial capacity through different postnatal ontogenetic pathways.

파노라마 방사선 사진을 이용한 한국인 소아의 하악공 위치에 대한 연구

본 연구는 소아에서의 성공적인 하치조신경 전달 마취를 위한 정보를 얻기 위해 파노라마 방사선 사진에서 한국인 소아의 하악공 위치를 분석하였다. 총 240명의 7-15세의 파노라마 방사선 사진을 수집하여, 연령에 따라 7-8세, 9-10세, 11-12세, 13-15세의 하위 그룹으로 나누었으며 각 그룹은 남녀 각 30명씩을 포함하였다. 좌우측의 하악공으로부터 하악절흔, 악각전절흔, 하악지 전연, 하악지 후연까지의 최단거리와 교합평면까지의 수직거리를 측정하였으며, 하악공으로부터 하악절흔과 악각전절흔의 거리의 비와 하악공으로부터 하악지 전연과 하악지 후연의 비를 계산하였다. 연구 결과는 다음과 같다. 1) 하악공의 하악지 내 상대적 위치는 남녀 모두에서 연령 증가에 따라 전방으로 이동하는 경향이 관찰되나, 수직적인 위치는 연령과 유의한 상관관계를 보이지 않았다. 2) 하악공의 교합평면과의 상대적인 위치는 연령 증가에 따라 교합평면 하방에서 상방으로 이동하였으며, 연령과 높은 상관관계를 나타내었다(p<0.05). 3) 여자보다 남자에서 하악공이 교합평면을 기준으로 더 상방에, 하악지 내 전후방 및 수직적으로는 하악지의 후상방에 위치하여 성별에 따른 차이를 보였다(p<0.05). The aim of this study was to evaluate the position of the mandibular foramen in panoramic radiographs of Korean children to provide information for successful inferior alveolar nerve block anesthesia. 240 panoramic radiographs of 7 to 15-year-old boys and girls were analyzed. The subjects were divided into 4 groups in boys and girls according to their age.; 7-8, 9-10, 11-12 and 13-15 years old. The shortest distances from the center of the mandibular foramen to the anterior border of ramus, to the posterior border of ramus, to the antegonial notch and to the mandibular notch and the perpendicular distances from the center of the mandibular foramen to the occlusal plane were measured. The following results were obtained. 1) Although the relative position of the mandibular foramen in the ramus of mandible tended to move anteriorly for both genders with age, the vertical position did not correlate with age. 2) The mandibular foramen moved upward in relation to the occlusal plane with age, and showed statistically significant correlation with age(p<0.05). 3) The mandibular foramina of boys, when compared to those of girls, were located more superiorly in relation to the occlusal plane and more superiorly and posteriorly in the ramus of mandible.

Subluxation of the Distal Radioulnar Joint as a Predictor of Foveal Triangular Fibrocartilage Complex Tears

The triangular fibrocartilage complex (TFCC) with its ulnar foveal attachment is the primary stabilizer of the distal radioulnar joint (DRUJ). The purpose of this study was to describe a technique for measuring the degree of subluxation of the DRUJ in wrist magnetic resonance imaging (MRI) examinations to predict tears involving the foveal attachment of the TFCC. We measured DRUJ geometry in wrist MRI examinations of 34 patients who were found to have foveal TFCC tears at surgery. We compared the results with DRUJ geometry in 11 asymptomatic controls. Subluxation of the ulnar head was assessed using transaxial MRI images obtained at the level of the DRUJ with the wrist in pronation. We quantified subluxation with a line spanning the sigmoid notch of the radius and a perpendicular line through the center of curvature of the articulating surface of the ulna. We calculated the ratio of the lengths of the dorsal and volar segments and normalized it to the center of the sigmoid notch. A total of 34 patients with intraoperatively confirmed tears of the foveal attachment of the TFCC had a mean dorsal ulnar subluxation measurement of 16% ± 4%, whereas the 11 controls had a mean subluxation measurement of 5% ± 4%. The results confirm the hypothesis that subluxation of the ulnar head relative to the sigmoid notch of the radius, as assessed by MRI with the wrist in pronation, is a predictor of tears of the foveal attachment of the TFCC. Diagnostic II.

Intra-Articular Fractures of the Distal Radius Evaluated by Computed Tomography

To describe the fracture lines of intra-articular distal radius fractures as evaluated by computed tomography scans. With computed tomography, we examined 95 intra-articular fractures of the distal radius from 91 patients. Multiplanar computed tomography images or 3-dimensional images, or both, were assessed. We divided the periphery of the distal articular surface of the distal radius into 6 segments (sigmoid notch, dorsoulnar, dorsoradial, volar radial, volar ulnar, radial styloid) and examined which segment had fracture lines. For fractures involving the sigmoid notch, we divided them by the location and the direction of the fracture lines entering the sigmoid notch. Next, we categorized the fractures into 3 fracture groups (extension group, neutral group, and flexion group) by the dorsal or volar angulation of the cortex of the distal radius. In all the fractures and in each of the 3 fracture groups, we described the frequency of the fracture lines in each segment and the number of the segments with fracture lines. The location and the direction of the fracture lines in the sigmoid notch were analyzed in each of the 3 fracture groups. The most frequent fracture type, seen in 21% of all fractures, had fracture lines in the sigmoid notch and the dorsoulnar segment. The frequency of the fracture lines was 77% in the sigmoid notch, 71% in the dorsoulnar segment, and 57% in the dorsoradial segment. The volar ulnar segment was lowest in frequency, at 13%. The fractures in the extension group were more common in the dorsoulnar segment and less common in the dorsoradial segment and the radial styloid segment. The scaphoid facet always had a fracture in the flexion or neutral group. In the extension group, the direction of the fracture lines from the sigmoid notch was dorsoradial or parallel to the volar articular edge. In contrast, the direction was parallel or volar radial compared to the volar articular edge in the flexion group. We documented the location and the direction of intra-articular fracture lines of the distal radius. The location and the direction of fractures showed different tendencies related to the volar/dorsal angulation of the distal radius. The findings might help in the evaluation, classification, and treatment of intra-articular fractures of the distal radius.

A three-dimensional analysis of the sigmoid notch

Fractures of the distal radius are among the most common injuries of the upper extremity, though treatment has traditionally focused on restoration of the radiocarpal joint and late sequelae may persist. X-ray imaging underestimates sigmoid notch involvement following distal radius fractures. No classification system exists for disruption patterns of the sigmoid notch of the radius associated with distal radius fractures. This study quantifies the anatomy of the sigmoid notch and identifies the landmarks of the articular surface and proximal boundaries of the distal radioulnar joint (DRUJ) capsule. Computed tomography scans of freshly frozen cadaveric hands were used - followed by dissection, and three-dimensional reconstruction of the distal radius and sigmoid notch. The sigmoid notch surface was divided into two surfaces and measured. The Anterior Posterior (AP) and Proximal Distal (PD) widths of the articulating surface were reviewed, along with the radius of curvature, version angle and depth. The study showed that the sigmoid notch is flatter than previously believed - and only the distal 69% of its surface is covered by cartilage. On average, it has about nine degrees of retroversion, and its average inclination is almost parallel to the anatomical axis of the radius. Clinical implications exist for evaluation of the DRUJ involvement in distal radius fractures or degenerative diseases and for future development and evaluation of hemiarthroplasty replacement of the distal radius.

Ligament Contribution to Patterns of Articular Fractures of the Distal Radius

Intra-articular fractures of the distal radius are common injuries, but the correlation between ligament attachments and fracture location is poorly understood. The purpose of this study was to assess the location of intra-articular fractures compared to the known ligament attachments of the distal radius. The authors retrospectively reviewed computed tomography scans of acute intra-articular distal radius fractures performed at 1 institution between 2001 and 2008. Of 145 scans, 45 were deemed unsuitable due to poor quality or presence of internal fixation in the distal radius, leaving 100 fractures for review. Fracture line locations of the distal radius were plotted to a standardized distal radius template and statistically analyzed for their relationship to known ligament attachments. Fracture lines were significantly more likely to occur at the intervals between the ligament attachments than at the ligament attachments. Common sites of fractures were the center of the sigmoid notch, between the short and long radiolunate ligaments, and the central and ulnar aspects of the scaphoid fossa dorsally. The sites of the ligament attachments to the distal radius were relatively protected. The likely site of the impaction of the carpus on the distal radius articular surface can often be construed from viewing the computed tomography scans, and the subsequent propagation of the fracture can be identified. Articular fractures of the distal radius are statistically more likely to occur between the ligament attachments. The ligamentous attachments of the distal radius to the volar carpus in an intra-articular distal radius fracture are relatively well preserved. Diagnostic III.

Feasibility of Endoscopic Intramedullary Fixation of Fractures of the Mandibular Condyle

Objective: 1) Describe a novel technique for internal fixation of mandibular condyle fractures, as well as a new type of implant for the same. 2) Demonstrate surgical feasibility of this technique in a cadaver model. Method: A transoral endoscopic approach was used to access the osteotomized mandibular condyle in 2 human cadavers. Titanium intramedullary implants were placed endoscopically after reaming of the medullary space without the need for transbuccal puncture or facial incisions. Results: Both cadaveric mandibular condyles were successfully repaired with rigid intramedullary internal fixation without the use of external incisions. Both insertion of a peg type implant and screwing a threaded implant into the condylar head are possible. The inferior portion of the implant remains exposed and the ramus of the mandible can be manipulated into position on the implant using retraction at the sigmoid notch. Conclusion: True total endoscopic repair of fractures of the mandibular condyle is possible by utilizing novel intramedullary titanium implants and a transoral endoscopic approach. This is the first description of the technique and implants for endoscopic intramedullary fixation of fractures of the mandibular condyle.