Timing of operation for blowout fractures with extraocular muscle entrapment

Abstract

Many authors have advocated early surgical intervention to avoid muscle degeneration in patients with blowout fractures with evidence of extraocular muscle entrapment imaged under computed tomography. However, there is still no golden standard with regard to the target timing of operations for releasing extraocular muscle. Between January 2002 and December 2011, the authors treated eight cases of blowout fracture with extraocular muscle entrapment. Notes from presumed cases of blowout fracture were retrospectively reviewed for information relating to surgical treatment and prognosis. In this series, a patient who was operated on 7 hours after injury showed the quickest recovery from diplopia. In contrast, a patient who was operated on 18 days after injury showed persistent diplopia for 2 years. Nevertheless, in patients who were operated on 3–11 days after injury, there was no obvious correlation between the outcome and the number of days between injury and the operation. It is concluded that, when emergency surgical intervention within several hours is not possible, it should be performed as soon after the injury as possible in order to prevent the increase of predictive fibrosis around the extraocular muscle.     

Paralysis of the first dorsal interosseous muscle after external fixation of a distal radial fracture treated by transfer of the extensor indicis proprius tendon

We describe a patient in whom the motor branch to the first dorsal interosseous muscle was injured by the pins of an fixator used to treat an unstable fracture of the distal radius. She was successfully treated by extensor indicis proprius transfer to the base of the proximal phalanx of the index finger.     

Bilateral symptomatic supernumerary muscle belly syndrome

A 32‐year‐old woman with a longstanding history of bilateral forearm pain had been unable to open her fingers and use her left arm (treated as reflex sympathetic dystrophy) since the age of 14. On physical examination there was fullness and tenderness of the distal volar forearms bilaterally; the quadriga test (when the patient was asked to make a tight fist quickly, with one finger fully extended passively) elicited burning pain. Operation confirmed that she had anomalous reversed forearm muscles bilaterally, and these were successfully resected.     

Facial reanimation by transposition of the masseter muscle combined with tensor fascia lata,using the zygomatic arch as a pulley

We have created a new way of reanimating the face, involving transposition of the masseter muscle combined with tensor fascia lata, and using the zygomatic arch as a trochlea to reconstruct the inferior facial paralysis. We used it on five patients who had facial palsy after excision of malignant parotid tumours. The wide skin defect that exposed the masseter muscle after total parotidectomy was reconstructed with a free flap. This method differs from those of other methods of transposing the masseter muscle in that force is applied at an upper lateral angle. Our method provided dynamic raising of the upper lip, the corner of the mouth, and the nasolabial fold in four patients. We consider it to be useful, particularly for prompt surgical reconstruction of facial palsy after total parotidectomy with a wide defect in the skin of the cheek.     

Suppression of the production of extracellular matrix and α-smooth muscle actin induced by transforming growth factor-β1 in fibroblasts of the flexor tendon sheath by hepatocyte growth factor

We examined the effectiveness of hepatocyte growth factor (HGF) in blocking production of transforming growth factor (TGF)-β1-induced collagen I, fibronectin, and α-smooth muscle actin (α-SMA) in the flexor tendon sheath of rabbits in vitro. Fibroblasts were obtained from the sheaths. Cell culture was supplemented with TGF-β1 5 ng/ml and increasing doses of HGF (10-40 ng/ml). The production of collagen I and fibronectin in supernatants culture were examined using an enzyme-linked immunosorbent assay (ELISA). α-SMA expression was assessed by western blot. TGF-β1 stimulated production of collagen I, fibronectin, and α-SMA greatly, while HGF significantly (p<0.05) reduced production of all components induced by TGF-β1 in a dose-dependent manner. This suggests that HGF effectively antagonises the action of TGF-β1 in cultured fibroblasts from flexor tendon sheaths. The results provide a cellular and molecular basis for HGF acting as a therapeutic agent for adhesions in flexor tendons.     

Electrical impedance myography in the diagnosis of radiculopathy

Introduction: We sought to determine whether electrical impedance myography (EIM) could serve as a diagnostic procedure for evaluation of radiculopathy. Methods: Twenty‐seven patients with clinically and radiologically diagnosed cervical or lumbosacral radiculopathy who met a “gold standard” definition underwent EIM and standard needle electromyography (EMG) of multiple upper or lower extremity muscles. Results: EIM reactance values revealed consistent reductions in the radiculopathy‐affected myotomal muscles as compared with those on the unaffected side; the degree of asymmetry was associated strongly with the degree of EMG abnormality (P < 0.001). EIM had a sensitivity of 64.5% and a specificity of 77.0%; in comparison, EMG had a sensitivity of 79.7% but a specificity of 69.7%. Conclusions: These findings support the potential for EIM to serve as a new non‐invasive tool to assist in diagnosis of radiculopathy; however, further refinement of the technique is needed for this specific application. Muscle Nerve 48:800–805, 2013     

Surface‐distributed low‐frequency asynchronous stimulation delays fatigue of stimulated muscles

Introduction: One important reason why functional electrical stimulation (FES) has not gained widespread clinical use is the limitation imposed by rapid muscle fatigue due to non‐physiological activation of the stimulated muscles. We aimed to show that asynchronous low‐pulse‐rate (LPR) electrical stimulation applied by multipad surface electrodes greatly postpones the occurrence of muscle fatigue compared with conventional stimulation (high pulse rate, HPR). Methods: We compared the produced force vs. time of the forearm muscles responsible for finger flexion in 2 stimulation protocols, LPR (f_L = 10 Hz ) and HPR (f_H = 40 Hz ). Results: Surface‐distributed low‐frequency asynchronous stimulation (sDLFAS) doubles the time interval before the onset of fatigue (104 ± 80%) compared with conventional synchronous stimulation. Conclusions: Combining the performance of multipad electrodes (increased selectivity and facilitated positioning) with sDLFAS (decreased fatigue) can improve many FES applications in both the lower and upper extremities. Muscle Nerve 48 : 930–937, 2013     

Homogenates of skeletal muscle injected with snake venom inhibit myogenic differentiation in cell culture

Introduction: Viperid snakebite envenomings are characterized by muscle necrosis and a deficient regenerative response. Methods: Homogenates from gastrocnemius muscles of mice injected with the venom of the snake Bothrops asper or with 2 tissue‐damaging toxins were added to cultures of C2C12 myogenic cells. Myoblasts proliferation and fusion were assessed. Venom was detected by immunoassay in mouse muscle during the first week after injection. Results: Homogenates from venom‐injected muscle induced a drop in the number of proliferating myoblasts and a complete elimination of myotube formation. The inhibitory effect induced by homogenates from venom‐injected mice was abrogated by preincubation of the homogenate with antivenom antibodies but not with control antibodies. This finding provides evidence that the effect is due to the action of venom in the tissue. Conclusions: Our observations suggest that traces of venom in muscle tissue might inhibit myotube formation and preclude a successful regenerative response. Muscle Nerve, 2013