Stephan Grechenig

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.

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

Backgroundu2003Fossa 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 resultsu2003We 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. Interpretationu2003The anatomic variations of the trochanteric sometimes make it difficult to identify the correct entry point for an intramedullary nail.

Frequency of instrument breakage during orthopaedic procedures and its effects on patients.

BACKGROUNDnWhile breakage of an orthopaedic instrument is a relatively rare occurrence, orthopaedic surgeons need to be familiar with this complication and how to deal with it. Relatively little information about this subject has been published.nnnMETHODSnEvery case of instrument breakage during orthopaedic procedures performed in two hospitals during a two-year period was documented prospectively. All patients were followed for a postoperative period ranging from twelve to thirty-six months, during which radiographs in two planes were made to assess changes in, or migration of, the broken object.nnnRESULTSnDuring the observation period, 11,856 surgical procedures were performed in the two hospitals. The overall rate of instrument breakage was 0.35%. The broken piece was removed in five cases, and the broken instrument was left in situ in thirty-seven cases. During the follow-up period, none of the patients had any symptoms.nnnCONCLUSIONSnIn most cases, breakage of an orthopaedic instrument is not a problem. Any instance of instrument breakage should be fully documented in the surgical report.

The percutaneous antegrade scaphoid fracture fixation―A safe method?

INTRODUCTIONnThe object of this study was to assess the risk of injury to tendons, nerves and vessels in percutaneous antegrade scaphoid fracture fixation.nnnMETHODSnForty cadaveric forearms were used in this study. A guide wire for cannulated headless compression screws was inserted percutaneously in each scaphoid according to established surgical technique.nnnRESULTSnNo nerve or vessel injuries were observed. Tendons however were injured in 5 out of the 40 specimens. This included the extensor pollicis longus tendon in two specimens, the extensor carpi radialis tendon in two specimens and the extensor digitorum tendon in one specimen.nnnCONCLUSIONSnSoft tissue injuries may be avoided by extending the skin incision and performing blunt dissection down to guide wire and screw entry point. In this manner, dorsal antegrade fixation of scaphoid fractures by using cannulated headless compression screws can be considered to be a safe and reliable technique for fixation of scaphoid fractures.

Frequency of successful intra-articular puncture of finger joints: influence of puncture position and physician experience

OBJECTIVEnPhysicians and specialists routinely perform IA punctures and injections on patients with joint injuries, chronic arthritis and arthrosis to release joint effusion or to inject drugs. The purpose of this study was to investigate the frequencies of intra- and peri-articular cannula positioning during this procedure.nnnMETHODSnA total of 300 cadaveric finger joints were injected with a methyl blue-containing solution and subsequently dissected to distinguish intra- from peri-articular injections. To assess the influence of puncture position on successful injection, half of the joints were injected dorsally and the other half dorso-radially. To assess the importance of practical experience for a positive outcome, half of the injections were performed by an inexperienced resident and half by a skilled specialist.nnnRESULTSnThe overall frequency of occurrence of peri-articular injections was much higher than expected (overall: 23%, specialist: 15%, resident: 32%) The failure rate was significantly higher than the average with the joints of the little finger and the DIP joints of each phalanx.nnnCONCLUSIONSnEven skilled specialists cannot guarantee to insert the cannula into the joint in every case. Unintended peri-articular drug injection moreover may affect the surrounding ligaments or tendons, leading to serious complications. Correct positioning of the needle in the joint may be facilitated by fluoroscopy in doubtful cases.

The risk of injury to the peroneal artery in the posterolateral approach to the distal tibia: a cadaver study.

Objectives: The posterolateral approach to the distal tibia allows excellent visualization, direct reduction, and stabilization of posterior malleolar fractures. Concomitant fractures of the lateral malleolus may be internally fixed through the same approach. The approach may also be used for pilon fractures and for bone grafting in nonunions. This study aims to establish the safe zone of proximal dissection to avoid injury to the peroneal vessels when performing the posterolateral approach to the distal tibia. Methods: Twenty-six unpaired adult lower limbs were dissected using the posterolateral approach to the distal tibia. The peroneal artery was identified, as it coursed through the interosseous membrane on deep dissection and the level of its bifurcation was noted over the tibia. Perpendicular measurements were made from these points to the tibial plafond and distal fibula. Results: The peroneal artery bifurcated at 83 ± 21 mm (range, 41–115 mm) proximal to the tibial plafond and 103 ± 21 mm (range, 61–136 mm) from the distal fibula. The peroneal artery perforated through the interosseous membrane 64 ± 18 mm (range, 41–96 mm) proximal to the tibial plafond and 81 ± 20 mm (range, 42–113 mm) from the distal fibula. Conclusions: The posterolateral approach to the distal tibia allows direct reduction of posterior malleolus fractures. The peroneal artery may bifurcate and perforate through the interosseous membrane as little as 41 mm from the tibial plafond. Dissection around this region should be performed with care due to the wide variation in vasculature, however, once the peroneal artery is mobilized, a buttress plate can easily be placed beneath it.

Does the IOFIX improve compression in ankle fusion

BACKGROUNDnThe new IOFIX is an intra-osseous fixation device comprising an X-post through which a lag screw passes to apparently improve force distribution across an arthrodesis. We conducted a novel human cadaveric study. Our null hypothesis was no difference in force exists in an ankle arthrodesis model stabilized with the IOFIX or a conventional single lag screw.nnnMETHODnIn ten cadaver ankles a pressure transducer was compressed as an IOFIX and standard single lag screws were alternately compared.nnnRESULTSnThe median average force created by the IOFIX was 3.95kg and 2.4kg for the single conventional lag screw (p⩽0.01). The IOFIX improved contact area across the arthrodesis with a median average of 3.41cm(2) compared with 2.42cm(2) in the lag screw group (p⩽0.03).nnnCONCLUSIONnOur results suggest an IOFIX improves force distribution across an ankle arthrodesis compared with a single conventional lag screw.

Morphology of the tibialis anterior muscle and its implications in minimally invasive plate osteosynthesis of tibial fractures.

We examined the variation in the origin of the tibialis anterior muscle from the lateral aspect of the tibial shaft and interosseous membrane as well as the variation in the morphology of its musculotendinous junction. Forty cadaveric lower leg specimens (20 right and 20 left) were dissected to reveal the anterior compartment. The origin of the tibialis anterior muscle and its relation to the lateral tibial shaft and interosseous membrane were determined. The position of the musculotendinous junction relative to the medial malleolus was also measured. Tibial length ranged from 29.5 to 45 cm (mean, 36.5+/-3.1 cm). The distal limit of the muscle origin was 5.9 to 20.5 cm (mean, 12.1+/-3.3 cm) from the tip of the medial malleolus. The distance between the musculotendinous junction and the medial malleolus ranged from 1.4 to 10.8 cm (mean, 6.1+/-1.9 cm). The attachment of the muscle belly ends between 15.3 and 31.8 cm (mean, 24.4+/-4.1 cm) distally from the joint line at the knee. There was no statistical correlation between tibial length and muscle morphology.This variation warrants consideration in the percutaneous insertion of screws in the distal end of long plates, as the neurovascular bundle may be injured in patients with a shorter muscle belly. We advocate an open distal approach to protect the neurovascular bundle during insertion of the plate and distal screws.

Median Nerve Palsy following Elastic Stable Intramedullary Nailing of a Monteggia Fracture: An Unusual Case and Review of the Literature

Monteggia fractures are rare in children, and subtle radial head dislocations, with minor plastic deformation of the ulna, may be missed in up to a third of cases. Complications of Monteggia fractures-dislocations include persistent radial head dislocation, forearm deformity, elbow stiffness, and nerve palsies at the time of presentation. An unusual case of median nerve palsy following elastic stable intramedullary nailing of a type I Monteggia lesion in a 6-year-old girl is presented, and we highlight that, although most nerve palsies associated with a Monteggia fracture-dislocations are treated expectantly in children, early intervention here probably provided the best outcome.