Wolfgang Pichler

Differences in length and cross-section of semitendinosus and gracilis tendons and their effect on anterior cruciate ligament reconstruction A CADAVER STUDY

The purpose of this anatomical study was to explore the morphological variations of the semitendinosus and gracilis tendons in length and cross-section and the statistical relationship between length, cross-section, and body height. We studied the legs of 93 humans in 136 cadavers. In 43 specimens (46.2%) it was possible to harvest the tendons from both legs. We found considerable differences in the length and cross-section of the semitendinosus and the gracilis tendons with a significant correlation between the two. A correlation between the length of the femur, reflecting height, and the length of the tendons was only observed in specimens harvested from women. The reason for this gender difference was unclear. Additionally, there was a correlation between the cross-sectional area of the tendons and the length of the femur. Surgeons should be aware of the possibility of encountering insufficient length of tendon when undertaking reconstructive surgery as a result of anatomical variations between patients.

Computer tomography aided 3D analysis of the distal dorsal radius surface and the effects on volar plate osteosynthesis

The aims of this study were to measure the size of Lister’s Tubercle, the extent of the extensor pollicis longus (EPL) groove and the dihedral angle of the distal dorsal radius. Computer tomography scans of 30 forearms were performed by using a 64-slice Siemens SOMATOM Sensation® CT system (Resolution 0.6 mm). DICOM raw data were calculated to 3D by MIMICS® software (Materialise, Leuven, Belgium). The size of Lister’s Tubercle varied from 1.4 to 6.6 mm (average 3.3 mm) in height radial to the tubercle, and from 5.6 to 18.6 mm (average 13.2 mm) in length. The depth of the EPL groove varied from 0.6 to 3.2 mm (average 1.6 mm). The height on the ulnar side, between the depth of the groove and the tip of the tubercle, varied from 2.2 to 5.8 mm (average 3.4 mm). The dihedral angle of the distal dorsal radius varied from 110° to 135° (average 123°). The variations in height of Lister’s Tubercle and in depth of the EPL groove are considerable. This needs to be taken into account when performing volar plating of distal radius fractures otherwise screws may inadvertently penetrate the dorsal cortex of the radius potentially leading to EPL rupture.

The influence of lateral and anterior angulation of the proximal ulna on the treatment of a Monteggia fracture: AN ANATOMICAL CADAVER STUDY

We have investigated the anatomy of the proximal part of the ulna to assess its influence on the use of plates in the management of fractures at this site. We examined 54 specimens from cadavers. The mean varus angulation in the proximal third was 17.5 degrees (11 degrees to 23 degrees ) and the mean anterior deviation 4.5 degrees (1 degrees to 14 degrees ). These variations must be considered when applying plates to the dorsal surface of the ulna for Monteggia-type fractures. A pre-operative radiograph of the contralateral elbow may also be of value.

Delayed hypopharyngeal and esophageal perforation after anterior spinal fusion: primary repair reinforced by pedicled pectoralis major flap.

Study Design. This report documents a case of delayed hypopharyngeal and esophageal perforation after anterior spinal fusion and reviews relevant literature. Objectives. Presentation of an alternative solution of primary repair and reinforcement of a delayed esophageal and hypopharyngeal perforation after anterior spinal fusion. Summary of Background Data. Anterior plating is generally used for stabilization after cervical spine trauma. Esophageal and hypopharyngeal perforation is a rare but potentially life-threatening complication due to mediastinitis with consecutive septic shock and multiorgan failure. Methods. Our patient was operated on after cervical trauma caused by car accident. The neurologic condition did not improve in the postoperative period. About 4 months later, the patient had increasing dysphagia as well as episodes of odynophagia. Flexible esophagoscopy showed a perforation of a part of the plate from the hypopharynx down to the proximal esophagus. Primary repair reinforced by a pedicled pectoralis major flap was done without complications. Results. Postoperative fluoroscopy as well as endoscopy showed no signs of perforation. Swallowing was possible without any further episodes of dysphagia or odynophagia. Neck movement was unconfined. Conclusions. Primary repair reinforced by pedicled pectoralis major flap has been shown to be an alternative in case of combined hypopharyngeal and esophageal perforation due to orthopedic spine stabilization. Advantage of the pectoralis major muscle flap is no functional loss of neck movement.

Morphometric Analysis of Lister's Tubercle and Its Consequences on Volar Plate Fixation of Distal Radius Fractures

PURPOSE The objective of this study was to measure the size and shape of Listers tubercle and the depth of the extensor pollicis longus (EPL) groove to assess the risk of injury to the EPL tendon when performing volar plating of distal radius fractures. METHODS The length and height of Listers tubercle and the depth of the EPL groove were measured in 100 cadavers. RESULTS The size of Listers tubercle varied from 2 to 6 mm (average, 3.6 mm) in height radial to the tubercle and from 6 to 26 mm (average, 18.3 mm) in length. The depth of the EPL groove varied from 1 to 5 mm (average, 2.8 mm), with 63% being greater than 2 mm in depth. The height between the depth of the groove and the tip of the tubercle varied between 4 and 10 mm (average, 7.1 mm). No correlation was found with gender or right-side or left-side specimens. CONCLUSIONS The individual and combined height of Listers tubercle and the depth of the EPL groove are considerable. This fact needs to be considered when performing volar plating of distal radius fractures because of the possibility that it might be difficult to determine precisely the presence and amount of past-pointing of the distal screws.

Anatomical basis of the risk of radial nerve injury related to the technique of external fixation applied to the distal humerus

PurposeStabilization of humeral shaft and elbow fractures can be achieved with an external-fixator. Reports about nerve injuries associated with this procedure are rare in literature. Purpose of this anatomical study was to examine the relation of the radial nerve to distal humeral half pins.MethodsPercutaneous insertion of external-fixator half pins was performed in 20 upper limbs of 20 cadavers, according to established technique, laterally in the distal humerus.ResultsDissection of the upper limbs showed radial nerve injury in four of the 40 placed half pins. The proximal half pin impaled the nerve in one case and the distal half pin in three cases. Moreover the nerve was directly in contact with the pins in nine cases (five proximally, four distally).ConclusionsInsertion of external-fixator half pins in the distal humerus can easily injure the radial nerve. Thus we advocate a larger skin incision, blunt dissection to the lateral cortex of the humerus and retraction of soft tissue during half pin insertion.

Intra-articular injection of the acromioclavicular joint

Intra-articular punctures and injections are performed routinely on patients with injuries to and chronic diseases of joints, to release an effusion or haemarthrosis, or to inject drugs. The purpose of this study was to investigate the accuracy of placement of the needle during this procedure. A total of 76 cadaver acromioclavicular joints were injected with a solution containing methyl blue and subsequently dissected to distinguish intra- from peri-articular injection. In order to assess the importance of experience in achieving accurate placement, half of the injections were performed by an inexperienced resident and half by a skilled specialist. The specialist injected a further 20 cadaver acromioclavicular joints with the aid of an image intensifier. The overall frequency of peri-articular injection was much higher than expected at 43% (33 of 76) overall, with 42% (16 of 38) by the specialist and 45% (17 of 38) by the resident. The specialist entered the joint in all 20 cases when using the image intensifier. Correct positioning of the needle in the joint should be facilitated by fluoroscopy, thereby guaranteeing an intra-articular injection.

Does the anteromedial or anterolateral approach alter the rate of joint puncture in injection of the ankle?: A CADAVER STUDY

Injection or aspiration of the ankle may be performed through either an anteromedial or an anterolateral approach for diagnostic or therapeutic reasons. We evaluated the success of an intra-articular puncture in relation to its site in 76 ankles from 38 cadavers. Two orthopaedic surgical trainees each injected methylene blue dye into 18 of 38 ankles through an anterolateral approach and into 20 of 38 through an anteromedial. An arthrotomy was then performed to confirm the placement of the dye within the joint. Of the anteromedial injections 31 of 40 (77.5%, 95% confidence interval (CI) 64.6 to 90.4) were successful as were 31 of 36 (86.1%, 95% CI 74.8 to 97.4) anterolateral injections. In total 62 of 76 (81.6%, 95% CI 72.9 to 90.3) of the injections were intra-articular with a trend towards greater accuracy with the anterolateral approach, but this difference was not statistically significant (p = 0.25). In the case of trainee A, 16 of 20 anteromedial injections and 14 of 18 anterolateral punctures were intra-articular. Trainee B made successful intra-articular punctures in 15 of 20 anteromedial and 17 of 18 anterolateral approaches. There was no significant difference between them (p = 0.5 and p = 0.16 for the anteromedial and anterolateral approaches, respectively). These results were similar to those of other reported studies. Unintended peri-articular injection can cause complications and an unsuccessful aspiration can delay diagnosis. Placement of the needle may be aided by the use of ultrasonographic scanning or fluoroscopy which may be required in certain instances.

Various Circular Arc Radii of the Distal Volar Radius and the Implications on Volar Plate Osteosynthesis

The purpose of this anatomical study was to explore the different circular arc radii of the distal volar radius and provide more detailed anatomic information that will further the understanding of volar plate osteosynthesis. The profiles of the volar distal radii of 100 cadaver specimens were measured with a common profile gauge. Profiles were copied onto paper and then matched to a best-fit circular arc template to determine the radius of curvature on the radial and ulnar sides of the distal volar radius. The mean circular arc radius of the distal volar surface was 2.6 cm (+/-1 cm, 1-6 cm) on the radial side and 2.3 cm (+/-1 cm, 1-6 cm) on the ulnar side. A significant difference (P<.01) was noted in the radii of curvature of the distal radius in 55% of the study population. In 37% of these cases, the circular arc radius flattens toward the ulnar side. In 63%, it flattens toward the radial side. This characteristic may lead to a false rotation position of the distal fracture fragment following volar plate osteosynthesis. In addition, suboptimal or incorrect plate position may result due to the discrepancy between the plate radius of curvature and the radius of curvature of either the radial or ulnar volar radius.

Anatomy of the greater femoral trochanter: clinical importance for intramedullary femoral nailing: Anatomic study of 100 cadaver specimens

Background Fossa piriformis is considered the correct point of entry for a straight femoral nail. A trochanteric overhang may make the access to fossa piriformis difficult. We investigated the anatomy of the trochanteric region, paying special attention to the entry point for antegrade intramedullary femoral nailing. Methods and results We studied 100 cadaver specimens. In 63 specimens a shape with a free entry point was found, whereas in 37 cases the entry point was either half or fully covered. In 9 specimens the entry points could not be exactly located from a cranial aspect. Interpretation The anatomic variations of the trochanteric sometimes make it difficult to identify the correct entry point for an intramedullary nail.