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Chapter II THE INJURY AND ITS MANAGEMENT Barnes Woodhall and Gilbert W. Beebe Before any follow-up data can be presented it is essential that the reader be familiar with the characteristics of the acute lesion which has been chosen for study here, and with its management. The selection of various aspects of the injury and its treatment was, of course, limited by /} priori concepts of the significance of individual factors in peripheral nerve re- generation and, even more important, by the quality and detail of the average military record. This chapter serves to introduce the different classifications of injury and treatment upon which the later analysis of regeneration depends. It includes definitions and discussions of the problems which were encountered in creating the many classifications and in adapting them to the individual case. At the same time, the struc- ture of the entire sample is revealed in terms of these classifications, and the implications of the sampling plan are explored. Since the abstracting of service medical records necessarily extended to all active treatment received in military hospitals, the pattern of surgical management reveals important information on such points as the proba- bility of reoperation and the practice of cuff removal. In the belief that they provide rough measures of the cost of peripheral nerve injuries to the Armed Forces, duration in hospital and disposition were also abstracted and the resulting data appear in this chapter. A. CHARACTERISTICS OF THE NERVE INJURY The information included under this general heading pertains to the origin of the case in terms of the sampling plan, identity of the injured nerve, presence of associated nerve injury, presence of other associated injuries of importance, presence of serious infection, type of nerve injury, site of injury, agent of injury, and presence of plastic repair at site of nerve injury. Information on age at injury is also included here. Omitted from this Ibt as an aspect of management is the length of any surgical defect. Each of these characteristics is discussed briefly, together with certain in- interrelations among them, especially those involving site of injury and identity of nerve injured. All 3,656 injured nerves, or the involved in- jured extremities, of 2,554 injured men are used in the tables from which these observations are drawn. In any particular table, however, a smaller total may appear because of lack of information concerning one or more of the factors involved. II

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Three main groups of cases were established from the 10 rosters that were available and from scattered local cases that were added to this study. Group A consists entirely of cases from the large Army Peripheral Nerve Registry and within the geographical sampling areas defined for the five follow-up centers. It includes both sutures and lyses and is the most representative material in the sample except, of course, with respect to the ratio of sutures to lyses and, for the lyses, the presence of associated nerve lesions. Group B, on the other hand, was formed from the five lysis rosters chosen, it will be recalled, on the basis of the care with which the incomplete lesions had been assessed. Group C contains cases from the Army Peripheral Nerve Registry which fell outside the respective sampling areas, and from the other rosters of complete lesions (except roster 68) described on pages 6-7, i. e., cases of special interest because of some particular characteristic of injury or treatment. Thus, here are to be found Hoen's plasma glue sutures, Wrork's overseas sutures, the Lyons-Woodhall series with special pathological studies, and cases from the Registry allo- cated for study only because of arterial injury, normal bone resection, bulb suture, or nerve graft. Both sutures and lyses are represented in group C, but the factors of selection apply chiefly to sutures. The cases in group C, being of special interest for one reason or another, could not be accepted in advance as typical of peripheral nerve injuries or as homogeneous with the lesions in groups A and B. Accordingly, the several roster groups were compared on several major characteristics of injury. Most of the expected differences were found, although many of them are not as large as anticipated and seem of doubtful practical impor- tance despite their statistical reliability. Nevertheless, since group A contained 2,501 lesions, group B 280 lesions, and group C 875 lesions, it was decided that the descriptive analysis of each modality of recovery should be confined to group A insofar as it pertains to sutures. It was believed that the lyses should be drawn from all three groups, except that lyses from the Army Registry should also be confined to the sampling areas surrounding the five centers. In tables 10, 11, and 12 the sample is described in terms of the nerve involved, the presence of associated nerve injury to the same limb, and the number of lesions in the same nerve. As has been noted in previous studies, and despite the effort made in this study to secure adequate samples of the less frequently injured nerves, upper extremity nerve injuries were twice as numerous as lower extremity injuries. In the upper extremity, the ulnar nerve was the most frequently represented of the three major nerve segments, followed in turn by the median and the radial. In the lower extremity, thigh injuries involving some component of the sciatic nerve were more common than injuries in the foreleg. The sampling plan was geared to a study of the seven major peripheral nerves; occasionally, however, associated injuries involving other nerves were encountered. Regeneration studies were conducted upon these latter nerves where motor function was involved but no analysis has been made of the data. 33

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Table 10.—Identity of Nerve Affected, Total Sample Number of lesions Percentage dis- tribution Part of body Nerve Nerves in this part of body All nerves Upper extremity 707 516 1,000 44 9 19.3 14. 1 27.4 1.2 .2 31.1 Radial 22.7 43.9 1.9 .4 Ulnar Axillary Total 2,276 62.3 100.0 Lower extremity 6 341 404 235 394 0.2 9.3 11.1 0.4 24.7 29.3 17.0 28.6 Sciatic-peroneal . . . Tibial 6.4 10.8 Sciatic-tibial Total 1*380 37.7 100.0 Grand total 3,656 100.0 Table 11.—Associated Nerve Lesions * on the Same Limb, by Nerve Total lesions Percentage with other nerve lesions, same limb Nerve Median 707 58.0 Radial 516 32.8 Ulnar . 1,000 40.2 Peroneal 341 24.9 Sciatic-peroneal 404 94.3 Tibial 235 35.7 394 97.0 1 In addition to the major nerves only the following were included in counting asso- ciated nerve lesions: musculocutaneous, axillary, and femoral. A high percentage of patients with nerve injury had an associated nerve injury, and multiple injuries tended to be concentrated in a single limb. The very high percentage of associated nerve injury indicated for the

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Table 12.—Number of Lesions Per Injured Nerve, Total Sample Number of lesions per nerve Injured nerves Number Percent One 3,615 40 1 98.88 1.09 .03 Two Three Total .... 3,656 100.00 sciatic-peroneal and sciatic-tibial lesions is a consequence of regarding these two sciatic branches as individual nerves for the purpose of the regeneration studies. When the multiplicity of peripheral nerves injured in the same extremity was analysed in terms of various aspects of the clinical history, the following conclusions emerged: A high injury in the arm more often involved other nerves than a low injury, and the same phenomenon was present in the lower extremity; strangely enough, the more nerves injured in a limb, the less likely was concomitant bone or joint injury; there was a tendency for infection to be more common in the presence of multiple nerve injuries; associated vascular injuries were rare in the lower extremity but they were common in the upper extremity and were strongly associated with the presence of additional nerve injuries; for the radial nerve, there was a marked tendency for a major plastic surgical procedure to be associated with other nerve injuries. In table 13 appears the summary classification adopted for the type of injury to the nerve, as well as the frequency with which each type was found in the entire sample. The finer nuances of this classification are presented in another publication (46), but the criteria for its application Table 13.—Type of Injury to Nerve, Total Sample Type of injury Number Percent 22 0.6 386 11. 1 Complete nerve division 1,795 51.7 449 12 9 776 22.3 43 1.2 2 0. 1 Total known 3,473 99 9

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to the military records are of interest here. The purpose of the classifica- tion was to describe the extent of the lesion as it appeared to the operator. Thus no attention was paid to the evidence of electrical testing or of microscopic pathological study, although both types of observation were included elsewhere in the abstract of the case for statistical purposes. The following notes guided the classification of individual cases: NORMAL NERVE COMPRESSED BY SCAR TISSUE. This is rarely found. Nerve is bound down in scar tissue but it is not itself scarred or neuromatous. No suture is done in these cases. COMPLETE NERVE DIVISION. This means there is or has been a complete separation of the nerve. Include here cases with only connecting strand of fibrosed tissue or few nonfunctioning fibers between two ends of the nerve—also cases where there is continuity but the operator sections the scarred area or "neuroma" and finds no fibers going through. In absence of operation report, if summary speaks of severance and suture overseas, this classification may be used. Bulb sutures indicate complete nerve division. PARTIAL NERVE DIVISION. Partial separation implies that the unsevered portion of the nerve contains functioning nerve fibers. When there is partial division and the rest is neuromatous* it should be coded as a neuroma, not a partial division. When the only continuity is scarred connective tissue, code complete rather than partial severance. There can be cases of partial division with a neuroma at one end and glioma at the other, but there must be some functioning fibers going through. NEUROMA IN CONTINUITY. Neuroma is more than external scar; there must be growth in the nerve itself. This classification is not compatible with a statement that any normal fibers are going through. If part of the cross section is neuromatous, and part normal, classify as partial division. There must be positive evidence of neuroma in continuity before it can be coded here. (See complete division.) If nerve is described as densely scarred or extensively scarred it is in most cases a neuroma in continuity. If nerve appears grossly normal, but on palpation at opera- tion nerve is described as lumpy, hard, irregular, or with fusiform thickening, or otherwise abnormal, it can be considered a neuroma in continuity. Where there is partial division and the rest neuromatous code as neuroma in continuity. STRETCH INJURY. Will also be called a traction injury. The classification as to specific site is exhibited in table 14. Like those of table 10, and despite the sampling plan, these data reflect the concen- tration of nerve injuries in the upper extremity and demonstrate once more the higher percentage of wounds in that part of the extremity adjacent to the trunk. Of greater import is the implication that the high and low nerve injuries will be adequate to permit comparisons as to nerve regenera- tion. Indeed, if indicated, good regeneration studies appear possible for injuries received in any part of either extremity. An analysis of the agent causing injury, among other matters, has been presented in an earlier statistical review of the Army Registry material (87). For the purposes of the regeneration study, it appears sufficient to note that 92 percent of the nerve injuries were sustained in combat. In large numbers of peripheral nerve injuries the extremity is involved in one or another grave concomitant injury to other tissues. As defined in this analysis, an associated injury is one that would be expected to bear a direct and significant relationship to the treatment and anatnrnical regener- 35

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ation of the injured nerve. The relation between site of nerve injury and associated injury was studied separately for injuries in the upper and lower extremity. In both sets of cases there was an intimate association between the location of the nerve lesion and the probability of a bone or joint injury. Bone or joint injury was defined as a significant gunshot or other wound of such structures causing open fracture or destruction of tissue demanding specific orthopedic care. The probability was low for injuries above the elbow and in the upper two-thirds of the thigh, and high for injuries below these points. Also, if a bone or joint injury were incurred its chance of normal healing varied significantly in relation to site of injury in the upper extremity. These figures are shown in table 15. Table 14.—Specific Site of Lesion, Total Sample l Percentage distri- bution Part of body Specific site Number of lesions Lesions in this part of body All le- sions Arm middle third 32 422 402 358 216 217 224 208 136 12 0.9 11.8 11.2 10.0 6.0 6.0 6.2 5.8 3.8 0.3 1.4 18.9 18.1 16.1 9.7 9.7 10.1 9.3 6.1 0.5 Elbow Forearm, upper third .... Forearm, middle third . . . Wrist Hand Total 2,227 62.1 99.9 Lower extremity Thigh upper third 433 259 184 256 108 49 46 16 9 12.1 31.8 19.0 13.5 18.8 7.9 3.6 3.4 1.2 0.7 Thigh middle third ..... 7.2 5.1 7.1 3.0 1.4 1.3 0.4 0.3 Knee Leg middle third Leg, lower third Ankle Foot Total 1,360 37.9 99.9 Grand total 3,587 99.9 'Omitted are 49 upper and 20 lower extremity cases for which site was not specified in sufficient detail for this classification. 36

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In the upper extremity, associated arterial injury varied quite significantly with site of injury, being especially common in the upper arm. An asso- ciated arterial injury was further defined as one implicating a major vessel supplying an extremity, i. e., the subclavian, axillary, brachial, radial, and ulnar in the upper extremity, and the iliac, femoral, popliteal, and tibial in the lower. Tables 16 and 17 show the variable frequency of such arterial injuries in association with the particular nerve affected and the specific site of the nerve lesion. Table 15.—Percentage of Nerve Injuries With Associated Bone or Joint Injury, and Percentage of Bone or Joint Injuries in Which Normal Healing Occurred, by Site of Injury and Part of Body Site of nerve injury Percentage of nerve lesions with bone or joint injury Percentage of bone or joint in- juries with normal healing Upper extremity Shoulder, arm upper third Arm, middle third Ann, lower third Forearm, upper third Forearm, middle third Forearm, lower third Elbow Wrist, hand All sites Lower extremity Thigh* upper third Thigh, middle third Thigh, lower third Leg, upper third Leg, middle third Leg, lower third Knee Ankle, foot All ? iteg. . 27.1 44.3 40.3 65.0 58.0 63.8 64.7 45.3 47.4 77.2 67.4 48.6 58.9 61.5 69.7 67.6 76.1 65.0 28.9 21.6 21.2 49. 1 57.1 52.2 28.1 52.0 30.1 73.6 67.9 69.2 79.2 71.4 75.0 79.2 92.3 74.6

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Table 16.—Associated Arterial Injurv, by Nerve Percentage with asso- ciated arterial injury Percentage with asso- ciated arterial injury Nerve Nerve 32.0 Tibial 3.9 Ulnar 23.4 Sciatic -peroneal 3.0 Radial 15. 1 Sciatic-tibial 3.0 Peroneal 1.5 Table 17.—Associated Arterial Injury, by Site of Nerve Lesion Percentage with asso- ciated arterial Percentage with asso- ciated arterial injury Site of nerve injury Site of nerve injury injury Upper extremity Lower extremit r 42 4 2.5 27 8 Thigh middle third 3.9 16.2 Thigh, lower third . 3.3 Forearm, upper third 15.7 Knee 2.4 Forearm, middle third 15.2 Leg, upper third 0.9 26 8 6. 1 Elbow 12.3 Leg lower third 0 Wrist, hand 21.2 Ankle 6. 3 All sites 24 4 Foot 0 2. 8 The frequency of major plastic repair at the site of the nerve lesion also varied significantly by location of the nerve injury. Among injuries in the upper extremity, plastic repair was more common in the forearm than in the arm. A parallel situation existed among injuries to the lower extremity (table 18). The agent of injury was moderately related to the probability of associated bone or joint injury and also to the chance of an infection sufficient to delay nerve operation. It was entirely unrelated to the likelihood of arterial injury or plastic repair. The percentages with bone or joint injury, and the parallel percentages with infection, appear in table 19. In a series of military battle casualties one does not expect to find sufficient variation in as;e to have biological significance, but since the follow-up 38

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Table 18.—Plastic Repair at Site of Nerve Injury, by Site of Nerve'Injury, and by Body Part Percentage with plastic repair Percentage with plastic repair Site of nerve injury Site of nerve injury Upper extremity Lower extremity Shoulder, arm, upper third 4. 3 3 2 Arm, middle third 7.6 Thigh, middle and lower 8.1 thirds 7.2 18.9 Knee 16.5 Forearm, middle third 21. 1 14.2 20 5 Elbow 14.7 All sites 8 8 Wrist, hand 14.4 All sites ... 11 8 Table 19.—Associated Bone or Joint Injury and Infection, by Agent of Injury, All Peripheral Nerve Lesions Combined Percentage of nerve lesions with associated bone or joint injury Percentage of nerve lesions with associated infection Agent Combat gunshot wounds 41.5 9.3 Noncombat gunshot wounds 47.0 2. 3 Cutting instruments and closed wounds 27.1 6. 4 All agents 40. 9 8 9 results pertain to a particular series of men, their age should be recorded here (table 20). In summary, the foregoing data serve to define the nerve injury in terms of distribution, associated nerve injury, type of nerve injury, the specific site of the nerve injury, the agent causing the injury, and the presence of associated injury to bone, vessel, and soft tissue. It is evident that any adequate number of individual nerve injuries is available for study at an site in the extremity. Furthermore, such injuries may be found with related nerve injury, an association that may not impair the study of anatomical regeneration but certainly may adversely implicate function of the extrem- ity. This is of even greater import when it may be noted that a single limb is involved in multiple nerve lesions in a high percentage of such instances.

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As would be suspected from the nature of the rosters and the origin of the wounds, this material shows a high percentage of completely severed nerves incurred in combat. Of real interest to the military surgeon is the pro- nounced incidence of concomitant tissue injury with the specific nerve lesions and, in particular, the association of bone injury. Table 20.—Age of Patient at Injury, Total Sample Age, in completed years Nerve lesions Age, in completed years Nerve lesions Number Percent Number Percent Under 20 348 661 550 497 389 258 222 10.6 20.1 16.7 15.1 11.8 7.8 6.7 32-33 162 126 4.9 3.8 1.8 0.8 20-21 34-35 22-23 36-37 ... . 58 25 24-25 26 27 28-29 Total known .... 3,296 100.1 30-31 B. MANAGEMENT OF THE NERVE INJURY Just as the preceding section is focussed upon the nerve injury, the present section has to do with its management and is designed to furnish background for the subsequent chapters rather than to provide generalizations about peripheral nerve injuries as a whole. The definitive operation is here defined as the last operation undertaken to treat the injury with an antici- pated good result, and no lysis may be called the definitive operation if it follows a suture or graft. All subsequent tables on management refer to it. A cuff removal following a suture or graft is not classified as a defini- tive operation; a suture done after an unsuccessful graft is, however, classi- fied as a definitive operation. In the analysis of the effect of number of operations upon nerve regeneration, bulb suture was not counted as a sepa- rate operation but considered to be the first stage of an anticipated defini- tive suture, but explorations, transpositions, and other operations following more definitive procedures were counted. Neurolysis, removal of a tantalum cuff thought to act as a barrier to nerve regeneration, and un- successful suture were defined as operations. An approximation suture, usually performed at the time of wound toilet, was not defined as an oper- ation. Since it is the definitive operation which appears on the follow-up card, the subsequent portions of this report revolve around it, and what- ever is learned from the tables in this section will provide useful background data. It should be noted that subsequent tables will embrace a total of 3,416 injured nerves with definitive operation rather than the total of 3,656 injured nerves used heretofore. The sequence of operations terminated by the definitive operation will be discussed in a subsequent section. 40

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The features of the definitive operation which were abstracted from the military records are as follows: Number of operations. Interval from injury to operation. Calendar date of operation. Medical echelon of repair. Training of surgeon. Type of surgery performed. Special features of operation, e. g., bulb suture, mobilization. Length of surgical defect after resection. Other operative procedures prior to separation, e. g., tendon transplant, arthrodesis. Suture materials employed. Use of cuff. Placement of stay suture. Technique of neurolysis. Tension on suture-line. Results of electrical stimulation. Condition of nerve ends just prior to anastomosis. At the outset a study was made of the lesions derived from the three main roster groups as to their comparability in respect to treatment. These groups are, it may be recalled: A. Army Peripheral Nerve Registry cases within the sampling areas. B. Lysis rosters (rosters 40, 47, 90, 92 described on p. 7). C. Other rosters (rosters 39, 48, 61, 86, 88) and Registry cases outside the sam- pling areas. The rosters, of course, consist of men, so that the lesions contributed by each roster group may be both complete and incomplete. This is especially true of groups A and C. From the comparisons which were made, it seemed evident that the Registry cross section (group A) differed significantly from group C in a number of respects. These differences were not always striking but were sufficient to support the decision to limit the descriptive parts of the main chapters to sutures of the group A rosters and to lyses from any source except Registry cases outside the sampling area. A typical study table which is of interest in terms of the probability of more than one operation, regardless of type, is table 21. In summary form, the points on which the roster groups were compared and the results are as follows: 1. Registry cases within the sampling area (group A) were operated upon somewhat less often than group C cases. 2. The definitive operation on group A cases occurred somewhat sooner after injury than is true of group C cases. 3. The average calendar date of the definitive operation is 1 to 3 months earlier for group A than group C cases. 4. Group A cases were operated upon more often overseas than group C. 5. Groups A and C do not differ as to special operative features. 6. Group A sutures were less often done with tantalum than group C sutures. 7. The use of a cuff does not vary between groups A and C. 8. A stay suture was more often used in group C sutures than in group A. 403930—57 6 41

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Table 42.—Evidence for Decision To Resuture, Lesions With First Operation Complete Suture, by Nerve Clinical evidence of no re- covery Clinical evidence of poor re- covery Palpa- tion of neuroma Nerve X-ray Total cases Median 1 13 14 4 32 Ulnar 1 26 28 6 61 Radial 2 9 7 0 18 Peroneal 12 21 15 1 49 Sciatic -peroneal 13 14 2 0 29 Tibial . 2 2 2 o 6 Sciatic-tibial 7 10 4 o 21 38 95 72 11 216 Table 43.—Reason for Obvious Failure of First Suture, Lesions With First Operation Complete Suture, by Nerve Tension caus- ing separation of suture line Scar tissue or neuroma Total cases Nerve Other Median 8 22 47 12 11 5 2 5 3 3 1 4 1 2 0 33 63 20 49 30 6 24 Ulnar 13 7 34 24 2 19 Radial Peroneal Sciatic-peroneal Tibial Sciatic-tibial Total known 107 104 14 225 Evidence for the decision to reoperate was also made the subject of a comparison of nerves; highly significant differences were found (table 42). The variation exhibited in table 42 parallels that seen in connection with the reason for surgery. In the lower extremity there was frequently X- ray or clinical evidence of no recovery. In the upper extremity X-ray evidence was rare; resuture was more often undertaken because recovery seemed poor. The reason for obvious failure of the first suture was also studied for variation among nerves, and quite significant differences were found (table 43). The chief reasons were tension, with separation of the suture-line, and scar tissue or neuroma formed at the suture-line. In the lower ex- 60

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tremity failure is more often (72 percent) attributed to tension with separa- tion of the suture-line and, in the upper extremity, to the formation of scar tissue or neuroma at the suture-line (70 percent). 2. First Operation Lysis A much more limited study was done on lesions first treated by lysis, using only the following characteristics: a. Interval from injury to operation. b. Type of lysis. c. Training of surgeon. These studies show, for the sample of initial lyses used here, that a subse- quent suture was done in 6.2 percent and a subsequent lysis, exploration, or cuff removal in 11.8 percent. The sampling plan for the present study, with its major emphasis upon definitive suture, and secondary emphasis upon definitive lysis, is a poor basis for estimating the chance that an initial lysis might suffice and be followed by additional surgery of one kind or another. However, the sample is not obviously biased in regard to the effect which various characteristics of injury and treatment might have upon the rate of reoperation, whatever the true average level may be. Differences among nerves are of little importance except that subsequent suture was rare in the tibial. In the upper extremity, gross height of lesion is of some importance; in median and ulnar injuries the chance of subsequent suture is 2.1 percent in high and 15.6 percent in low lesions first treated by lysis. Interval from injury to operation has considerable influence upon the chance of reoperation, early lyses being repeated or replaced by sutures more often than late. Training of surgeon bears no evident relation to the chance of reoperation. The type of lysis originally performed also has no relation to the chance of reoperation. 3. First Operation Partial Suture No detailed analysis was made of the probability of reoperation following partial suture. Among the 216 partial sutures done at first operation 44 cases were reoperated upon as follows: Complete suture 12 Partial suture 4 Lysis, cuff removal, etc 28 Total 44 The differences among nerves are not statistically significant. 4. First Operation Graft Reoperation following an initial graft was studied in the 42 cases available in the entire series. Of these, 12 were never reoperated upon, in 10 any reoperation was confined to exploration, cuff removal, or lysis, and in 20 an end-to-end anastomosis was eventually done. 61

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D. CUFF REMOVAL This brief analysis has to do with the matter of cuff removal in relation to selected characteristics of the nerve injury and its definitive treatment. The placing of some form of protective cuff about a peripheral nerve anastomosis has engaged the interest of surgeons since the beginning of nerve surgery. In World War II, and thus in the sample under study, the suture-line cuffs were formed from tantalum, either held in a cylindrical form by absorbable sutures or annealed in the desired circular form. In the present investigation first operations with sutures were chosen for all 7 major nerves and those with cuffs were subdivided as follows: 1. Cuff placed and not removed—755 cases, or 76.7 percent. 2. Significant cuff removal—94 cases, or 9.6 percent. A significant cuff removal was defined as an operative procedure designed to remove an assumed barrier to the normal course of nerve regeneration. 3. Routine cuff removal—135 cases, or 13.7 percent. Here the cuff was removed simply in the course of operative study of the suture line or because the therapeutic role of the cuff was regarded as temporary. The proportions falling into these three groups were then studied in relation to the following characteristics of the nerve injury without finding any significant variation: a. Site of injury. b. Type of lesion. c. Associated bone and joint injury. d. Medical echelon and tension. e. Special operative techniques. The significant cuff removals were done on the basis of factors outside the scope of the present analysis, namely, those having to do with the course of regeneration following suture. E. DISPOSITION FROM MILITARY HOSPITALS In abstracting the details of the injury and its management note was made of disposition in the expectation that useful information might be obtained on variation in the percentage of men returned to duty. How- ever, when the material on disposition was tabulated for the representative sample of sutures it was found that the percentage of men returned to duty was so small as to render fruitless any extended study of variation. For all 1,890 sutures in the representative sample (Registry cases within the sampling area) the percentage returned to duty is only 2.3, and the variation among the seven major nerves is confined within the range of 0.6 to 4.2 percent, as follows: Median 2. 9 Ulnar 1.7 Radial 3. 3 Peroneal 4.2 Tibial 3.2 «X

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Sciatic-peroneal 0. 9 Sciat ic-t i bial 0. 6 Total 2. 3 F. TIME IN MILITARY HOSPITALS Duration of hospitalization provides a rough measure of the medical cost of an illness or injury, and since there are rather good comparative military data on such broad categories as disease generally, nonbattle injury, and wounded-in-action plus battle injury, the opportunity was taken, in abstracting data from the service medical records, to note the total time from injury to final discharge from military hospital, usually at the same time as separation from service on a certificate of disability. Analysis of the resulting observations has been directed chiefly at estab- lishing any important differentials among the major nerves and assessing the relative influence of associated injuries of various kinds upon the time spent in hospital. On the average the men in this series, largely one of sutured nerve lesions, spent 523 days in service hospitals in contrast to about 54 days for Army wounded generally in World War II (4). The complete dis- tribution appears in figure 8 in comparison with the estimate for the Army wounded of World War II; the data are plotted in the form of the number remaining in hospital on successive days after admission. It will be seen that the number discharged from hospital prior to day 200 is negligible, and that the great bulk of the men were in hospital between 1 and 2 years. The actual duration of hospitalization was in many cases far less than that indicated, since many patients spent much of their time on furlough or leave from hospital. In general, men were hospitalized near their homes and, when specialized physical therapy was not important, they spent a great deal of time with their families. Men whose lesions fall into the representative sample of complete sutures do not vary greatly by nerve injured, although, of course, duration is longer for men with sciatic lesions. In table 44 the major nerves are compared as to median duration of hospitalization. The effects of associated lesions were sought by nerve, the nerves of the upper extremity being studied in the greatest detail. Table 45 exhibits some of the variation attributable to associated bone, arterial, and soft- tissue defects or chronic infection in pure lesions managed by complete suture. The variation seen in the median is quite significant statistically. Uncomplicated bone and arterial injuries do not appear to prolong hos- pitalization, but other complications or combinations of these associated injuries do greatly delay hospitalization; about 50 percent of the latter group remained in hospital beyond day 600, and only 15 percent were discharged before day 400. In the ulnar lesions, on the other hand, the variation seen in table 45 lies well within chance limits. In the radial, 63

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men with uncomplicated bone injuries were retained in hospital longer than men with none of the complications considered here, and men with two or more complications, infection, or plastic repair were delayed even further. In men with pure peroneal or tibial nerve lesions the various complications were considerably less frequent and exerted less effect upon duration. Table 44.—Median Days in Military Hospital, Men With Complete Sutures in the Representative Sample, by Nerve Nerve Median Nerve Median days days 541 Tibial 471 Ulnar 504 620 Radial 498 615 Peroneal . 558 All nerves 533 Associated nerve injuries were also studied for their possible effect upon duration of stay in hospital, but only in the median was significant evi- dence seen. In table 46 these data are presented for complete sutures on the median nerve with no complications involving bone, artery, or soft- tissue. In the ulnar and peroneal lesions associated nerve injury appeared to have no significant effect upon duration of stay. In the smaller tibial sample a suggestive difference was found between men with and men without associated nerve lesions, and of the type seen in table 46 for the median. In view of the variable influence of associated nerve and other lesions upon the duration of hospitalization for men with a given nerve lesion, the major nerves were compared on the basis of pure lesions devoid of all the complications which have been enumerated. No roster restrictions were placed upon the selection of cases, however. Table 47 provides these data for the three major nerves of the upper extremity, from which the advan- tage of uncomplicated radial injuries is immediately apparent. In addi- tion, men with ulnar lesions evidently were required to stay longer than men with median injuries. Tibial and peroneal lesions were similarly com- pared and found to differ significantly; 38 percent of the men with peroneal lesions were in hospital on day 600, in contrast to 17 percent of the men with tibial lesions. Finally, for all median sutures in the representative sample a rough di- vision was made into those with poor, fair, and good motor recovery on the basis of the modified British scale 9 and length of stay tabulated sepa- ' This scale is presented on p. 75 and discussed on pp. 113-117. The three recovery groups were selected as 0-2, 3-4, and 5-6 on the scale appearing on p. 75.

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rately for each group. Figure 9 presents the results of this comparison, which shows remaining on day 600 about 22 percent of the good results, 36 percent of the fair, and 58 percent of the poor. Table 45.—Duration of Hospitalization and Associated Injuries, Pure Nerve Lesions of the Upper Extremity Treated by Complete Suture Percentage distribution by days in hospital Type of associated injury Number of cases Less than 400 400-599 600 or more Total Median None .• 47.6 37.8 14.6 100.0 82 Bone only, with normal healing 36.5 44.4 19.0 99.9 63 41.7 54.2 4.2 100.1 24 Other l 15.3 32.2 52.5 100.0 59 Total 35.5 39.9 24.6 100.0 228 Ulnar None 27.7 50.5 21.7 99.9 184 30.3 48.7 21.1 100.1 152 53.1 37.5 9.4 100.0 32 Other * 26.5 49.0 24.5 100.0 102 Total 30.0 48.7 21.3 100.0 470 Radial 42.5 40.2 17.2 99.9 87 Bone only, with normal healing 23.9 54.9 21.2 100.0 113 Arterial only 100.0 0 0 100.0 2 Other1 12.9 45.9 41.2 100.0 85 Total 26.8 47.4 25.8 100.0 287 1 Bone with abnormal healing, or chronic infection, or plastic repair at site of nerve injury, or combinations of any of these with bone injuries healing normally or with arterial injury. 66

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Table 46.—Days in Hospital and Presence of Associated Nerve Injury, Complete Sutures on the Median Nerve, in Men With No Other Associated Injury Associated n erve injury * Days in hospital None Any Percent 47.6 Percent 19.4 Less than 400 400-499 12 2 22.6 500-599 25.6 21.0 600-799 8.5 19.4 800 or more 6. 1 17.7 Total 100.0 100.1 Number of cases 82 62 1 Involving ulnar, radial, axillary, or inusculocutancons. Table 47.—Days in Hospital for Men With Uncomplicated Nerve Lesions 1 Treated by Complete Suture, Nerves of the Upper Extremity Days in hospital Median Ulnar Radial Total Less than 300 Percent 6.9 Percent 4.6 Percent 12.5 Percent 6.8 300-399 28 5 19 2 28. 1 23.6 400-499 16.7 30.3 32.3 26.7 500-599 23.6 21.1 9.4 19.6 600-699 9.7 9.6 7.3 9.2 700 or more 14.6 15. 3 10.4 14.2 Total 100.0 100.1 100.0 100.1 Number of lesions 144 261 96 501 i No associated injuries of any kind. Length of hospitalization is a major factor in the medical logistics of peripheral nerve injuries. It is seriously questioned whether military hos- pitals should be asked to assume the entire burden of such care, and also whether such duration of hospitalization as is exhibited here should not now be regarded as excessive. This problem was attacked in World War II through the close association of convalescent hospitals with general hospitals to which men returned for reevaluation at regular intervals. 67

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B 8 9 it f) 68

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G. SUMMARY No attempt will be made here to summarize the considerable detail of background material presented here on the acute injury, its surgical man- agement, and the other points of special interest. The definitions and re- lationships presented here are, however, fundamental to an understanding of the subsequent chapters on regeneration, in which they figure promi- nently in the search for the determinants of end results. One might wish that additional information had been available, in reliable form, on the injury and its management, for peripheral nerve regeneration is an extraor- dinarily complicated matter, and even the array of factors presented in this chapter will not suffice to refine the surgeon's prognosis to the accuracy he might like. It remains unfortunately true that some factors with im- portant influences upon regeneration are not subject to measurement, or even observation, in a clinical series. 69

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