Ipsilateral mid-third clavicle fracture with grade V acromioclavicular joint dislocation

We report the case of a 20-year-old man with an ipsilateral mid-third clavicle fracture with grade V acromioclavicular joint (ACJ) dislocation. The combination of these two injuries is rare. A literature search produced various treatment algorithms. In this case, the patient was successfully treated with a Bosworth screw.This work was carried out in the Department of Orthopaedics, William Harvey Hospital, Ashford, Kent, UK     

Reciprocal axo-axonal synapses between the common inhibitor and excitor motoneurons in crustacean limb muscles

Summary Nerve terminals of the common inhibitor motoneuron in a crab (Eriphia spinifrons) limb closer muscle and in a crayfish (Procambarus clarkii) limb accessory flexor muscle make neuromuscular synapses with the muscle membrane (postsynaptic inhibition) as well as axo-axonal synapses with the terminals of the excitatory axon (presynaptic inhibition). That transmission is from the inhibitor to the excitor terminals at these axo-axonal synapses is indicated by the occurrence on the inhibitor membrane of presynaptic dense bars denoting sites of transmitter release. Axo-axonal synapses with the opposite polarity, in which transmission is from an excitatory onto an inhibitory terminal, were occasionally seen either adjacent to or separate from the inhibitory axo-axonal synapse. Nerve terminals of the specific inhibitor in the crayfish opener muscle were seen to make numerous axo-axonal output synapses upon excitatory nerve terminals but excitor nerve terminals were not seen to make output synapses onto inhibitor terminals. Thus reciprocal axo-axonal synapses appear to be a feature of the common inhibitor but not of the specific inhibitor. The excitor-to-inhibitor component of these reciprocal synapses may serve to limit transmitter output in the common inhibitor axon by activating glutamate_B receptors which facilitate efflux of K⁺ and hyperpolarization of the membrane.     

ACCESSORY SOLEUS MUSCLE: A PROBLEM OF AWARENESS

Reports of accessory soleus muscle are rare, perhaps as a result of it often remaining unrecognized. It presents as a swelling behind the ankle and may be mistaken for a tumour or inflammatory lesion, as occurred in the first of a series of three cases. The other two were incidental findings, one in a 30 year old man with an open tibial fracture and the other in a 9 month old child with a club foot. Patients present with either pain or a diagnostic problem. When large, it may make wearing of footwear difficult. Computerized tomography with electromyography enables confirmation of the diagnosis. Pain is relieved by epimysiotomy and when encountered incidentally during surgery, incision of the epimysium is all that is needed. Excision of the muscle may be considered only if wearing of footwear is difficult. The significance of its presence in a case of club foot is unknown. Disinsertion of its insertion was all that was required to obtain surgical correction of the deformity in the present case. Awareness of the condition will prevent unnecessary surgery in asymptomatic cases.