Peripheral nerve injuries (PNI) occur in 10% of combat casualties. In the immediate field-hospital setting, an insensate limb can affect the surgeon's assessment of limb viability and in the long-term PNI remain a source of considerable morbidity. Therefore the aims of this study are to document the recovery of combat PNI, as well as report on the effect of current medical management in improving functional outcome. In this study, we present the largest series of combat related PNI in Coalition troops since World War II.

From May 2007 – May 2010, 100 consecutive patients (261 nerve injuries) were prospectively reviewed in a specialist PNI clinic. The functional recovery of each PNI was determined using the MRC grading classification (good, fair and poor). In addition, the incidence of neuropathic pain, the results of nerve grafting procedures, the return of plantar sensation, and the patients' current military occupational grading was recorded.

At mean follow up 26.7 months, 175(65%) of nerve injuries had a good recovery, 57(21%) had a fair recovery and 39(14%) had a poor functional recovery. Neuropathic pain was noted in 33 patients, with Causalgia present in 5 cases. In 27(83%) patients, pain was resolved by medication, neurolysis or nerve grafting. In 35 cases, nerve repair was attempted at median 6 days from injury. Of these 62%(22) gained a good or fair recovery with 37%(13) having a poor functional result. Forty-two patients (47 limbs) initially presented with an insensate foot. At final follow up (mean 25.4 months), 89%(42 limbs) had a return of protective plantar sensation. Overall, 9 patients were able to return to full military duty (P2), with 45 deemed unfit for military service (P0 or P8).

This study demonstrates that the majority of combat PNI will show some functional recovery. Adherence to the principles of war surgery to ensure that the wound is clear of infection and associated vascular and skeletal injuries are promptly treated will provide the optimal environment for nerve recovery. Although neuropathic pain affects a significant proportion of casualties, pharmacological and surgical intervention can alleviate the majority of symptoms. Finally, the presence of an insensate limb at initial surgery, should not be used as a marker of limb viability. The key to recovery of the PNI patient lies in a multi-disciplinary approach. Essential to this is regular surgical review to assess progress and to initiate prompt surgical intervention when needed. This approach allows early determination of prognosis, which is of huge value to the rehabilitating patient psychologically, and to the whole rehabilitation team.

The outcomes of 261 nerve injuries in 100 patients were graded good in 173 cases (66%), fair in 70 (26.8%) and poor in 18 (6.9%) at the final review (median 28.4 months (1.3 to 64.2)). The initial grades for the 42 sutures and graft were 11 good, 14 fair and 17 poor. After subsequent revision repairs in seven, neurolyses in 11 and free vascularised fasciocutaneous flaps in 11, the final grades were 15 good, 18 fair and nine poor. Pain was relieved in 30 of 36 patients by nerve repair, revision of repair or neurolysis, and flaps when indicated. The difference in outcome between penetrating missile wounds and those caused by explosions was not statistically significant; in the latter group the onset of recovery from focal conduction block was delayed (mean 4.7 months (2.5 to 10.2) vs 3.8 months (0.6 to 6); p = 0.0001). A total of 42 patients (47 lower limbs) presented with an insensate foot. By final review (mean 27.4 months (20 to 36)) plantar sensation was good in 26 limbs (55%), fair in 16 (34%) and poor in five (11%). Nine patients returned to full military duties, 18 to restricted duties, 30 to sedentary work, and 43 were discharged from military service. Effective rehabilitation must be early, integrated and vigorous. The responsible surgeons must be firmly embedded in the process, at times exerting leadership.

We describe 261 peripheral nerve injuries sustained in war by 100 consecutive service men and women injured in Iraq and Afghanistan. Their mean age was 26.5 years (18.1 to 42.6), the median interval between injury and first review was 4.2 months (mean 8.4 months (0.36 to 48.49)) and median follow-up was 28.4 months (mean 20.5 months (1.3 to 64.2)). The nerve lesions were predominantly focal prolonged conduction block/neurapraxia in 116 (45%), axonotmesis in 92 (35%) and neurotmesis in 53 (20%) and were evenly distributed between the upper and the lower limbs. Explosions accounted for 164 (63%): 213 (82%) nerve injuries were associated with open wounds. Two or more main nerves were injured in 70 patients. The ulnar, common peroneal and tibial nerves were most commonly injured. In 69 patients there was a vascular injury, fracture, or both at the level of the nerve lesion. Major tissue loss was present in 50 patients: amputation of at least one limb was needed in 18. A total of 36 patients continued in severe neuropathic pain.

This paper outlines the methods used in the assessment of these injuries and provides information about the depth and distribution of the nerve lesions, their associated injuries and neuropathic pain syndromes.

Since the recognition of chronic exertional compartment syndrome (CECS) of the leg as a cause of exercise-induced leg pain was made in the 1950s, there has been no universally accepted diagnostic pressure. A 1997 review found 16 papers from 1962 to 1990, which have differing diagnostic criteria. The threshold pressure used at DMRC Headley Court is based on the work of Allen and Barnes from 1986, where in a patient with a suitable history, a dynamic pressure in the exercising muscle compartment above 50 mmHg is diagnostic.

We present the data gathered at DMRC Headley Court during the first year of the new protocol on dynamic pressure testing, from May 2007. The new exercise protocol involved exercising patients using a representative military task: the combat fitness test (CFT) using a 15 kg Bergen on a treadmill, set at 6.5 km/h with zero incline. During this period, we performed 151 intra-compartmental pressure studies in 76 patients. 120 were successful in 68 patients, with 31 technical failures. Patients complained of exercise-induced leg pain on performing the CFT and pointed to the muscles in either the anterior or deep posterior muscle compartments and these were exclusively tested with invasive studies. No patients complained of symptoms in the lateral or superficial posterior compartments and therefore neither was tested. The majority were performed in the anterior leg compartment (110 successful), with a few (9 successful) in the deep posterior compartment, and there was only one complication with a posterior tibial artery puncture.

The mean age of patient was 28.9 years (SD 6.7). In 119 compartment studies, the mean pressure was 97.8 mmHg (SD 31.7). This data is normally distributed (Shapiro Wilk test, W=0.98 p=0.125).

In summary, we present the data using the CFT as the exercise protocol in patients who give a history compatible with CECS and have symptoms of leg pain during exercise. This data has a mean of approximately 100 mmHg, which is double that of the diagnostic criteria of Allen and Barnes, who used running as the exercise protocol. The presence of a weighted bergen as well as the stride and gait pattern used during the loaded march may be contributory factors in explaining why the pressures are higher compared to other forms of exercise. Further work is ongoing with determining the intracom-partmental muscle pressure in normal subjects with no history of exertional leg pain performing the CFT.

Amputation is one of the most feared injuries in service personnel, particularly a worry that it will mean the end of their military career. The aim of this study was to determine the outcome, in relation to military service in UK military amputees.

UK service personnel who sustain an amputation undergo rehabilitation and prosthetic limb fitting at the Defence Medical Rehabilitation Centre Headley Court. This includes a realistic assessment of their employment capabilities, and they are graded by a Functional Activity Assessment (FAA). FAA ranges from 1 (fully fit) to 5 (unfit all duties). In addition the Short Form-36 Health Survey (SF-36) is completed on initial admission and at follow-up. We reviewed this information to determine the outcome of military amputees.

We identified 53 casualties who had sustained amputations. 8 had sustained an upper limb amputation, 41 a lower limb amputation, and 4 had sustained both an upper and lower limb amputation. 9 patients (including 1 Reservist) have left the forces by medical discharge, with the remaining 44 continuing to serve. 32 of the 44 have returned to work, albeit at a lower level. 49 patients have FAA grades and are at least 6 months post-injury. No patients were graded as FAA 1, 8 as FAA 2 (Fit for Trade and fit for restricted General or Military Duties), 18 as FAA 3 (Unfit for Trade but fit for restricted General or Military Duties), 18 as FAA 4 (Unfit for all but Sedentary Duties) and 5 as FAA 5. All bilateral and triple amputees were FAA 4 or 5. Other injuries such as blindness, severe brain injury or mental health issues also increased the FAA. Of the 32 patients who have returned to work, 8 are FAA 2, 12 are FAA 3, 11 are FAA 4, and 1 has not been graded. SF-36 data was available in 40 patients, available as paired scores for 34. The mean time between SF-36 scoring was 6.7 months (range 0.2 – 17.4). The mean SF-36 scores for Physical Component Summary (PCS) increased from 34.40 (SD 9.3) to 42.06 (SD 11.1), with Mental Component Summary (MCS) 52.01 (SD12.9) remaining similar at 52.92 (SD 12.0). Pre- and post-rehabilitation PCS scores improved with rehabilitation (p=0.0003). MCS scores were similar in these patients to the normal population, 50 (SD 10). No differences could be found within the unilateral lower limb amputation group regarding amputation level (trans-tibial, through-knee disarticulation, trans-femoral) and SF-36 scoring. Furthermore due to the low numbers, no conclusion could be made comparing the unilateral lower limb amputation group with the bilateral lower limb group, the unilateral lower limb plus upper limb, the bilateral lower limb and upper limb (trilateral), and the isolated upper limb groups.

This study is the first to report the outcomes, with regards to return to work, of the UK military amputee population injured in Afghanistan and Iraq. There is an almost even distribution of FAA score between 2, 3, and 4 for those back at work. Level of amputation and SF-36 scores do not seem to correlate, partly due to other injuries sustained that confound the patients’ perception of their health. SF-36 PCS scores increase significantly with rehabilitation, whilst MCS remain similar to the normal population.

Over 75% of combat casualties from Iraq and Afghanistan sustain injuries to the extremities, with 70% resulting from the effects of explosions. Damage to peripheral nerves may influence the surgical decision on limb viability in the short-term, as well as result in significant long-term disability. To date, there have been no reports of the incidence and severity of nerve injury in the current conflicts.

A prospective assessment of United Kingdom (UK) Service Personnel attending a specialist nerve injury clinic was performed. For each patient the mechanism, level and severity of injury to the nerve was assessed and associated injuries were recorded.

Fifty-six patients with 117 nerve injuries (median 2, range 1–5) were eligible for inclusion. This represents 12.9% of casualties sustaining an extremity injury. The most commonly injured nerves were the tibial (19%), common peroneal (16%) and ulnar nerves (16%). 25% (29) of nerve injuries were conduction block, 41% (48) axonotmesis and 34% (40) neurotmesis. The mechanism of injury did not affect the severity of injury sustained (explosion vs gunshot wound (GSW), p=0.53). An associated fracture was found in only 48% of nerve injuries and a vascular injury in 35%. The presence of an associated vascular injury resulted in more severe injuries (conduction vs axonotmesis and neurotmesis, p< 0.05). Nerves injured in association with a fracture, were more likely to develop axonotmesis (p< 0.05).

The incidence of peripheral nerve injury from combat wounds is higher than previously reported. This may be related to increasing numbers of casualties surviving with complex extremity wounds. In a polytrauma situation, it may be difficult to assess a discrete peripheral neurological lesion. As only 35% of nerves injured are likely to have anatomical disruption, the presence of an intact nerve at initial surgery should not preclude the possibility of an injury. Therefore, serial examinations combined with appropriate neurophysiologic examination in the post-injury period are necessary to aid diagnosis and to allow timely surgical intervention. In addition, conduction block nerve injuries can be expected to make a full recovery. As this accounts for 25% of all nerve injuries, we recommend that the presence of an insensate extremity should not be used as an indicator for assessing limb viability.