A radiological study to define safe zones for drilling during plating of clavicle fractures.

This study investigated the anatomical relationship between the clavicle and its adjacent vascular structures, in order to define safe zones, in terms of distance and direction, for drilling of the clavicle during osteosynthesis using a plate and screws following a fracture. We used reconstructed three-dimensional CT arteriograms of the head, neck and shoulder region. The results have enabled us to divide the clavicle into three zones based on the proximity and relationship of the vascular structures adjacent to it. The results show that at the medial end of the clavicle the subclavian vessels are situated behind it, with the vein intimately related to it. In some scans the vein was opposed to the posterior cortex of the clavicle. At the middle one-third of the clavicle the artery and vein are a mean of 17.02 mm (5.4 to 26.8) and 12.45 mm (5 to 26.1) from the clavicle, respectively, and at a mean angle of 50° (12 to 80) and 70° (38 to 100), respectively, to the horizontal. At the lateral end of the clavicle the artery and vein are at mean distances of 63.4 mm (46.8 to 96.5) and 75.67 mm (50 to 109), respectively. An appreciation of the information gathered from this study will help minimise the risk of inadvertent iatrogenic vascular injury during plating of the clavicle.

Diagnostic value of MR arthrogram in SLAP lesions of the shoulder.

BACKGROUND: Superior labrum anterior to posterior (SLAP) lesions are important cause of shoulder pain and instability. MR Arthrogram is key investigation for assessment of these lesions. We aimed this study to evaluate the diagnostic performance of MR Arthrogram in SLAP tears. MATERIALS AND METHODS: This was a retrospective study of 124 clinically diagnosed SLAP cases who had MR Arthrogram performed. Clinical, radiological and operative records were reviewed. MR Arthrogram findings were compared with arthroscopy. Those patients who did not undergo arthroscopy were not included in the final sensitivity analysis. RESULTS: Out of 124 cases, 54(43.54%) had normal MR Arthrogram, 32 (25.8%) had impingement or cuff related problems, 2 (1.61%) had Bankart lesions, and in 36 (29%) cases SLAP lesions were identified. Out of 54 patients with normal MR Arthrogram, 44 were discharged to physiotherapy and 10 underwent arthroscopy, showing SLAP lesion in one patient. Out of 32 patients with impingement or cuff problems, 19 were discharged to rehabilitation and 13 underwent surgery. Out of 36 patients with SLAP lesions, 5 recovered spontaneously, 5 were awaiting outpatient review and 26 underwent arthroscopy showing SLAP lesions in 22 cases. Overall, only 51 patients underwent arthroscopy. The MR Arthrogram was falsely positive in 4 cases (15.38%) and falsely negative in one case (3.84%). The sensitivity of MR Arthrogram was 95.6% (22/23), specificity 85.7% (24/28), positive predictive value 84.6% (22/26) and the negative predictive value was 96% (24/25). CONCLUSION: MR Arthrogram is a useful technique for the diagnosis and preoperative planning of suspected SLAP lesions. It may also save patients from unnecessary diagnostic arthroscopy.

Mid term results of PlantTan plate in the treatment of proximal humerus fractures.

This prospective study evaluates the clinical efficacy of a special implant, PlantTan plate used for fixation of displaced proximal humerus fractures. The PlantTan plate was used for internal fixation of closed displaced proximal humeral fractures in 68 patients from September 1999 to June 2002, in a University Hospital. One of the surgeries was for a non-union, and five patients were lost to follow-up. The patients' ages ranged from 19 to 76 years (mean 61 years and median 66 years). Of the remaining 62 patients, 42 were female and 20 were male. As defined using the Neer classification 19 patients had two part, 37 three part and 6 had four part fractures. Median follow-up was 19 months (11-38). The outcome was assessed using radiographs, American Shoulder and Elbow Surgeons (ASES) score and Hospital for Special Surgery (HSS) scoring system. Fifty-two patients achieved union in a median of 8 weeks. The median cumulative score of activities of daily living of ASES was 20.4/30 (13-27). According to HSS, 11 scored excellent, 26 good, 14 fair and 11 scored poor. Eight patients had fixation failure and two developed avascular necrosis. Eleven patients developed an infection. Six patients developed an infection resulting in implant removal. One had a transient and one permanent axillary nerve palsy. Since the PlantTan plate provides stability, early active rehabilitation can be instituted. The implant is distally placed reducing impingement symptoms. However, the implant requires wide surgical exposure, is bulky and has an unacceptable infection rate. The fixation failure is high in patients with osteoporosis. In view of the above encountered problems, the implant has been discontinued in our hospital.

Distal radial fractures in young goalkeepers: a case for an appropriately sized soccer ball.

OBJECTIVES: To assess the rate of wrist fractures in young goalkeepers sustained by the specific mechanism of "saving the ball" and the potential influence of ball size and environmental conditions. METHODS: A prospective, clinic based study in one institution over a 17 month period. Patients were identified by specific questioning. Information on play circumstances and subsequent clinical progress was documented. RESULTS: Twenty nine fractures of the distal radius were identified in young goalkeepers (age range 6-15 years) as a direct result of saving the ball. Most were managed simply in a plaster cast. Three patients required minor surgical interventions, and all fractures went on to unite without significant complications. Where ball size was known, 12 of the 15 fractures in children aged 11 years or less occurred as the result of impact with an adult sized ball compared with three when a junior ball was involved. This is statistically significant (p = 0.039). In the 10 children aged 12-15 years, only one fracture involved a junior ball; this is also statistically significant (p = 0.027). Six of the injuries (21%) occurred when the ball was kicked by an adult. Injuries occurred in both organised and informal games throughout the year. CONCLUSIONS: This specific mechanism of injury has not been widely acknowledged nor has the potential influence of ball size as a causative factor been examined. Recommendations for an appropriately sized soccer ball for young players exist but are not in universal use. Increased awareness of this particular injury mechanism is required.

The mechanism of femoral fracture in an impact accident.

BACKGROUND: Following the crash of a Boeing 737-400 aircraft on the M1 motorway at Kegworth, near Nottingham, England, on January 8, 1989, it became apparent that a large number of pelvic and lower limb injuries had been sustained by the survivors. Had there been a fire, these injuries would have severely hindered the ability of the occupants to escape. The mechanism of pelvic and lower limb injuries in impact accidents previously has been related to flailing of the limbs and axial loading of the femur as in automobile accidents. HYPOTHESIS: A bending load is the primary mechanism of femoral fracture in an impact aircraft accident rather than an axial load. METHODS: Two methods of study have been used to investigate the impact biomechanics of the pelvis and lower limb: a) clinical review of the injuries sustained in the M1 Kegworth accident; and b) impact testing. RESULTS: A clinical review of the M1 aircrash survivors suggested that axial loading was not the primary mechanism causing femoral fractures and suggested that a bending load might be applied to the femur. Impact testing confirmed that axial loading of the femur did not appear to be significant. CONCLUSIONS: Our study suggests that in the presence of intact occupant protection systems, a femoral bending mechanism involving the front seat spar of passenger seats is a primary cause of femoral fracture in an impact aircraft accident.

A modified crash brace position for aircraft passengers.

BACKGROUND: In 1989, a Boeing 737-400 aircraft crashed at Kegworth, near Nottingham, England. The survivors suffered a large number of pelvic and lower limb injuries, and approximately one-third of the passengers died. Subsequent research has suggested that the "brace-for-impact" position that passengers are advised to adopt prior to a crash landing might be modified in order to reduce the incidence of such injuries. The aim of this research was to evaluate biomechanically such a modified crash brace position. HYPOTHESIS: A modified brace position would help to prevent injuries to some passengers in the event of an impact aircraft accident. METHODS: Impact testing on forward-facing seats was performed at the Royal Air Force Institute of Aviation Medicine, Farnborough, England. Aircraft seats, mounted on a sled, were propelled down a track to impact at -16 Gx. A test dummy was used as the experimental model. Four dummy positions were investigated: a) upper torso braced forward and lower legs inclined slightly rearward of the vertical; b) upper torso braced forward and lower legs inclined forward; c) upper torso upright and lower legs inclined slightly rearward of the vertical; and d) upper torso upright and lower legs inclined forward. The impact pulses used were based on Federal Aviation Administration guidelines. Transducers located in the head, spine, and lower limbs of the dummy recorded the forces to which each body segment was exposed during the impact. These forces were compared for each brace position. RESULTS: Impact testing revealed that the risk of a head injury as defined by the head injury criterion was greater in the upright position than in the braced forward position. The risk of injury to the lower limbs was dependent in part on the flailing behavior of the limbs. Flailing did not occur when the dummy was placed in a braced, legs-back position. CONCLUSIONS: A modified brace position would involve passengers sitting with the upper torso inclined forward so that the passenger's head rested against the structure in front, if possible. The legs would be positioned with the feet resting on the floor in a position slightly behind the knee. The position differs from those previously recommended in that the feet are positioned behind the knee. This study suggests that such a position would reduce the potential for head and lower limb injury in some passengers, given that only a single seat type and single size of occupant have been evaluated. Standardization to such a position would improve passenger understanding and compliance. Such a recommendation should not obscure the fact that an occupant seated in a forward-facing aircraft seat, restrained only by a lap belt, is exposed to considerable forces during an impact accident. Such forces are capable of producing injuries in the femur, pelvis, and lumbar spine.