LUXATION. 



degrte of force that is hardly ever exerted. The dlP.oca- 

 tion is much promoted by the knee being, at tlie time of 

 the blow, in a moderate ftate of flexion, as the extenfor muf- 

 cles of the leg and ligament of the patella are then relaxed, 

 and the inner edge of the patella very prominent, fo as to be 

 expoled to the action of external force. 



In luxations of the patella outwards, the patient expe- 

 riences fevere pain, and cannotbcnd his knee. The latter 

 joint is deformed ; the pulley of the condyles of the femur 

 may be felt through the (Icin ; the patella forms a lumour in 

 front of the external condyle; the anterior furface of the 

 knee-pan is becoiae the external one, while the pollerior 

 ftn-face is now internal. The internal edge is turned more 

 forwards than inwards, and the external one is now turned 

 almoil quite backwards. 



The fymptoms of a luxation inwards are very analogous 

 to thofe of the preceding cafe, allowance being made for 

 the difference of fituation and the relation of parts to each 

 other. 



In every cafe of didocated patella, the redu£lion fliould 

 be effedod as foon as poffible. The patient is to Ije laid on 

 a bed, with his leg e:;tended and thigh bent. In this pofi- 

 tion the extcnfor -nufcles and their tendon, and the ligament 

 of the patella, are relaxed, and the latter bone may eafily 

 be put back into its proper fituation by prefTure. 



The inflammatory fweliing. which ufually alTcfts after an 

 accident of this nature, is to be fubdued by general and 

 topical bleeding, reft, and the faturnine lotions. After 

 the fweliing and inflammation are diminilhed, the joint fliould 

 be gently bent and extended every day, and -rubbed with 

 the linimentum fapon. comp. 



Lii :ation< of the Kn.-e. —The tibia, at its articulation with 

 the condyles of the femur, may be luxated either back- 

 wards, forwards, or to cither lide. 



A com;)letc luxation of the knee is an exceedingly un- 

 common circumltance, and could not happen without a total 

 laceration of all the numerous ligaments and tcndi)iis which 

 ftrengthen the joint. For the produftion of fuch mifchief, 

 we mud fiippofe the operation of a degree of violence that 

 hardly ever takes place, putting out of the queftion the 

 tearing away of limbs by cannon-balls. Even incomplete 

 luxations, inwards or outward.^, are very rare, fo much are 

 thefe accidents oppofed by the extent of the articular fur- 

 faces, and the ftrength of the ligaments and tendons. Dif- 

 locations forwards or backwards are Hill more uncommon, 

 in confequcnce of the manner in which the patella a':d 

 crucial ligament refill their occurrence. However, when 

 the leg is fixed, and the body and thigh are forced onwards, 

 the tibia may be partly forced away from the lower end of 

 the femur to one fide or another. The accident implies the 

 operation of confiderable violence. The deformity makes 

 the nature of the cafe very maiifcft. The reduflion is 

 cafily accomplifhed by pulhing the heads of the' bones in 

 oppofi'e dr.-cilions, while the articular furfaces are ?. little 

 feparated by moderate extenfion of the limb. After the 

 reduftion, the main bufinefsof the furgeon is to avert and 

 diminilh inflammation of the joint by cold waflies, 1 cches, 

 venefefllon, opening medicines, low diet, perfeil rell, &c. 



Luxations of the Anhh Joint.— The foot may be luxated 

 inwards, or outwards ; or forwards, or backwards ; and the 

 diflocation in any of thefe direftions may be complete or in- 

 complete. Luxations inwards or outwards, are the mod 

 fre.quent. The former, however, are more common than 

 the latter. As the internal malleolus docs not defccnd fo far 

 as the externa), the aftragalus has a lefs fpace to defcribe 

 from without inwards, than in the contrary diredtion. The 

 jdillccation inwards is occafioned by a violent abduftion of 



the foot, and is cluraAerized by the fole being turned out- 

 wards, and the back of the foot inwards, by the pain and 

 inabi.ity of moving the foot ; and, laftly, by the projection 

 made. by the adragalns below the internal malleolus. 



The luxation outwards is attended with an impoffibility 

 of moving the foot ; the fole is turned inwards and the back 

 of the foot outwards ; and the attragalus projetls below the 

 exteriuil malleolus. 



All luxations of the foot (hould be reduced as quickly as 

 poflible. One afTiftant is to make the countcr-exjenfion by 

 fixing the leg, and, while another draws the foot, the fur- 

 geon is to pnlh the latter part in a direclion contrary to that 

 ill which it is luxated: Nothing facilitates the redu£lion of 

 diflocations of the ankle fo materially as relaxing the power- 

 ful mufcles of the calf of the leg, by bending the knee and 

 extending the foot. 



When the redu£lion has been acconipliflied, the limb is to 

 be put in fplints, jull as if the cafe were a tradlure of the 

 log, (fee FuACTURE,) and the antiphlogifLic treatment is 

 indicated for the prevention of violent inflammation. 



Theie cafes, in former days, generally ended fo badly, 

 that J. L. Petit recommends amputation never to be delayed 

 more than twenty-four hours after the accident. More 

 niadern experience, however, has proved the gcnerarpcffi- 

 bility of curing diflocations of the ankle, ar.d this even when 

 tlie cafe is compound, that is, attended with a wound com- 

 municating with the injured point. 



A frafture of the fibula near its lower end is a frequent 

 complication of a luxation of the foot inwards. That bone, 

 therefore, fliould always be carefully examined in the latter 

 cafe. 



Luxations forwards and backwards, lefs frequent than 

 thofe defcribed, are however fometimes met with. The firll 

 is occafioned by a fall backwards while the foot is fixed to 

 the ground ; the fecond by a fall on the feet, with the body 

 inclined forwards and the leg much bent. The luxation for- 

 wards is more difficultly produced than that backwards, on 

 account of the articular pulley of the aftragalus, which in- 

 clines towards the pollerior fide, being permitted to llide 

 much on the tibia without abandoning it in the extenfion of 

 the foot. When the extenfion is carried too far, luxation 

 forwards is produced. 



In the luxation backwards, the external and pofterior liga- 

 ments and the pofterior part of the capfule are torn ; in that 

 forwards the anterior and external ligaments, the anterior 

 fibres of the internal lateral ligament, and the anterior part 

 of the capfule, are torn. The fymptoms of the firft fpecits 

 are, a diminution of length in that part of the foot between 

 the lower part of the leg and the anterior extremity of the 

 toes, elongation of the heel, tenfion of the tendo Achiili.i, 

 and relaxation of the extenfors of the toes. It is impcffible 

 either to bend or extend the foot ; this fymptom diliin- 

 guifhes luxation from iprain, in which the foot may be moved, 

 though not without pain, however high the inflammation 

 may be. 



Contiary fymptoms accompany the luxation forwards: 

 the foot is lengthened, the heel is fhortened, and the foot, 

 much extended, cannot be bent, &c. 



The reduction of both is eafily effefted, after which it 

 will be neceffary to put the limb in fplints, and lay it in the 

 bent poilure. 



Tiie very thick and tliort ligamentous fubftance which 

 unites the aftragalus to the os calcis, binds them fo ftrongly 

 together, that they follovv one another in their motions and 

 form, as it were but one bone. Hence they are never com- 

 plett'ly feparated, even in the moft defperate cafes of luxa- 

 tion of the foot ; but one or both of them may be luxated 



j^ troiu 



