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Critical evaluation of mangled extremity severity scoring system in Indian patients
Injury, Int. J. Care Injured 34 (2003) 493–496
Critical evaluation of mangled extremity severity scoring system in Indian patients Sansar Sharma∗ , Ashish Devgan, K.M. Marya, Nitesh Rathee Department of Orthopaedics, Paraplegia and Rehabilitation, Postgraduate Institute of Medical Sciences, Rohtak 124001, Haryana, India Accepted 28 March 2002
Abstract Amputation of a mangled extremity is repugnant to the patient and the surgeon. However, prolonged unsuccessful attempts at salvage are costly, highly morbid and sometimes lethal. Much discussion has taken place regarding which criteria predict successful salvage, and predictive indices have been proposed in an attempt to identify limbs for which attempted salvage is unlikely to succeed. The mangled extremity severity score, or MESS system is the most thoroughly validated of the various classification systems, but at present there is no predictive scale that can be used with confidence to determine whether to amputate or attempt to salvage a mangled lower extremity. MESS system based on four significant criteria (with increasing points with worsening prognosis) i.e. skeletal injury, limb ischaemia, shock and patient age, has become a standard method to determine which one of the mangled extremities will eventually undergo amputation or salvage. Keeping in view the paucity of studies on Indian patients, a prospective trial of MESS was done in 50 patients who had 56 mangled extremities during the last 3 years. A significant difference between the MESS value of salvaged limbs (4.7) and amputated limbs (8.6) was found. MESS value of more than 7 was most specific and was found to have a positive predictive value of 100%. The results have been compared with Western literature and authors suggest that nerve injuries and irreparable soft tissue loss should be given an extra point each. In bilateral cases, the MESS value of each limb should be properly assessed (especially when patient is in shock), as the score may increase because of the other injured limb. © 2002 Elsevier Science Ltd. All rights reserved.
1. Introduction The management of massive upper and lower extremity trauma is a subject of considerable interest and controversy. The emergent management of these patients particularly those with vascular compromise poses a difficult decision for both the surgeon and the patient. The question of limb salvage versus primary amputation has been usually based on subjective clinical parameters rather than objective ones [1]. The decision to amputate has significant repercussions medically, economically, socially and medicolegally [2]. When amputation is inevitable, performing early surgery enhances patient survival, reduces pain, disability and shortens hospitalisation [3]. Gregory et al. in 1985 [4] were the first to propose a mangled extremity syndrome index for the predictability of amputation in a mangled extremity. For a long time, surgeons have had the technical ability to salvage most, if ∗ Corresponding author. Present address: 48/11-J, Medical Campus, Rohtak 124001, Haryana, India. E-mail address: [email protected] (S. Sharma).
not all, tibial fractures with vascular compromise. However, this is often “technique over reason” and often the end result is a physically, psychologically, financially and socially crippled patient with a useless salvaged limb [5]. Helfet et al. in 1990 [1] observed that the multiple grading systems were complex, not readily obtainable initially, the majority of patients did not fit the absolute criteria laid down for amputation and were based on retrospective study. Hence, they proposed a mangled extremity severity score (MESS) based on four variables i.e. skeletal/soft tissue injury (1–4 points), limb ischaemia (0–3 points), shock (0–2 points) and patient age (0–2 points). They concluded that this relatively simple, readily available scoring system of objective criteria was highly accurate in acutely discriminating between limbs that were salvageable to those that were unsalvageable and better managed by primary amputation. Observing the importance of the entity and paucity of any Indian study, we critically analysed the predictability of amputation or salvage in a mangled extremity by using the MESS in Indian patients.
0020-1383/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 0 2 0 - 1 3 8 3 ( 0 2 ) 0 0 2 1 4 - 0
494
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
Table 1 Mangled extremity severity score [1] Type
Characteristics skeletal/soft tissue
Injuries
Points
1 2 3 4
Low energy Medium energy High energy Massive crush
Stab wounds, simple closed fractures, smaller-calibre gunshot wound Open or multiple-level fractures, dislocations, moderate crush injuries Shotgun blast (close range), high velocity gunshot wounds Logging, railroad, oil rig accidents
1 2 3 4
Shock group 1 Normotensive haemodynamics 2 Transiently hypotensive 3 Prolonged hypotension
BP stable in field and in OR BP unstable in field, but responsive to intravenous fluids Systolic BP <90 mmHg in field and responsive to intravenous fluid only in OR
0 1 2
Ischaemia 1 2 3 4
A pulsatile limb without signs of ischaemia Diminished pulses without signs of ischaemia No pulse by Doppler, sluggish capillary refill, paraesthesia, diminished motor activity Pulseless, cool, paralysed and numb limb without capillary refill
0a 1a 2a 3a
group None Mild Moderate Advanced
Age group (years) 1 <30 2 >30 3 >50
0 1 2
OR: operating room; BP: blood pressure. Amputation was advised if score was ≥7. Salvage was done if score was ≥6. a Points × 2 if ischaemia exceeds 6 h.
2. Material and methods
Table 2 Salvage procedures done in patients with MESS <7
Fifty consecutive patients with mangled extremities belonging to either sex and any age admitted to Pt. B.D. Sharma PGIMS, Rohtak were included in the study. Vitals were recorded and all resuscitative measures were instituted. Initial management of the mangled extremity was started in the form of thorough irrigation with copious normal saline, followed by meticulous debridement, pressure bandage, temporary splintage and antibiotics. MESS scoring was done, according to the Table 1. Primary fracture alignment, stabilisation and vascular repair if indicated, were carried out. Gradual delayed primary closure, split thickness skin grafting and fasciocutaneous flap coverage was undertaken as and when required (Table 2). Iliac bone grafting was undertaken in patients with primary bone loss or where fracture healing was delayed. Each patient was followed up at a regular interval of 2 weeks up to a minimum of 6 months and at each follow up patient was examined clinically and radiologically. Many patients, despite
Salvage procedure
No. of limbs (N = 56)
Fracture management External fixator/Illizarov POP cast Enders nail Unreamed tibial nail
38 9 7 2
Soft tissue management SSG Fasciocutaneous flap Myocutaneous flap Debridement and dressing
24 8 4 20
Vascular repair
4
having MESS values of more than 7, refused amputation primarily. In such patients we observed, whether they underwent secondary amputation and the final functional status of the salvaged limb (Table 3).
Table 3 Results at the end of follow up period End results
No. of limbs (N = 56)
Primary amputation (MESS ≥7)
16
Secondary amputation Refused consent for primary amputation (MESS ≥7 initially) Massive, crushing soft tissue injury (MESS <7 initially) Asensate and functionally useless limb (MESS <7 initially) Severe deformities, shortening and severe stiffness of knee and ankle (MESS <7 initially)
12 2 5 4
Average time between injury and amputation 1 day 9 3 11 18
months days months months
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
3. Results and discussion In the present study, there were 56 mangled extremities in 50 patients (44 males and 6 females). Roadside accident was the commonest mode of trauma. Injuries included in this series were Gustilo type IIIa, IIIb and IIIc involving fracture of both bones of leg, supracondylar femur and also crush injury of soft tissue. Thirty extremities had a Gustilo type IIIc injury. There was a significant difference in the mean MESS values; 4.7 in the limbs that were salvaged and 8.6 in the limbs that were amputated. This is almost the same as seen in the prospective study of Helfet et al. [1] in which the mean MESS values were 4.00 for salvaged limbs and 8.8 for amputated limbs. 3.1. Relevance of MESS value Out of 56 lower extremities, amputation was indicated in 28 extremities because the MESS value was ≥7. Primary amputation was done in 16 extremities and in 12 extremities (with MESS ≥7), consent for primary amputation was not given by the patient or by their attendants. Amputation is a big social stigma and repugnant to the patient as well as their relatives, in a largely agriculture based society of a developing country like India. Hence, they are reluctant for giving consent at the very outset after injury. All the 12 extremities, in which primary amputation was indicated (but refused initially), had a secondary amputation ultimately. The reasons for giving consent for secondary amputation were in the majority of cases to a functionally useless limb carrying the economic burden of repeated medical and surgical interventions like repeated debridements, dressings and costly antibiotics. The MESS value of ≥7 had a 100% predictable value for amputation. This is the same as seen in prospective study of Helfet et al. [1] in which there was 100% predictable value for amputation in extremities which had a MESS value of ≥7. Robertson [6] applied MESS to 152 patients with severely injured lower limbs and found that all the cases with a score of more than 7 required amputation; some with scores of <7 eventually came to amputation. The average hospital stay for each patient was 10 days in primary amputation and 28 days in secondary amputation. This shows the cost to each patient of secondary amputation is almost three times as compared to the patient who had a primary amputation, excluding the cost of his or her extra operations. This aspect is very important in the health care system of any third world country. 3.2. Salvage procedures—vascular repair Only in four extremities (7%), was vascular repair attempted. This is because majority of extremities with vascular injury had crushed vessels and many had also lost the ‘golden 6 h’ from injury to reporting in accident and emer-
495
gency department. In the two extremities, resection and end to end anastamosis of the popliteal artery was done. Two extremities had anterior and posterior tibial artery repair where the wound was clean and vessels were not crushed. The two extremities, in which a popliteal artery repair was done, showed improvement in circulation and were normal. The MESS value for these extremities was <7. On the other hand, the two extremities in which an anterior and posterior tibial artery repair was done, ultimately resulted in amputation. These two extremities had a MESS score >7. This shows the importance of the fact that vascular repair should never be attempted if the MESS value is ≥7. 3.3. Massive crush injury and irreparable soft tissue loss Two patients had massive crush injuries in a railway accident. But their MESS value was <7 on the account of their being normotensive, the limb fell in the mild ischaemic group and they were 18 and 19 years of age. Therefore, they were not advised to have a primary amputation. Unfortunately, both these patients began to develop features of crush syndrome and rising blood urea. Secondary amputation had to be carried out as a life saving procedure despite their initial MESS value of <7. Had they underwent primary amputation which was deferred initially because of their MESS value of <7, they might not have developed the early features of crush syndrome and uraemia. We suggest that severe, crushing soft tissue injury should be given an extra point in the MESS apart from being extra cautious to detect the earliest signs of crush syndrome and uraemia. Robertson [6] in 1991, in his series of 152 cases observed that in severely injured lower limbs, certain cases required amputation even when their MESS value was <7. In our series, there were six extremities (11%) that had a MESS value <7 (5 and 6) and were not advised to have an amputation. They required multiple operations for their bone and soft tissue defect like external fixator, Illizarov, skin grafting, free flaps, bone grafting and repeated debridements. Their mean hospital stay was 49 days (after multiple admissions). This is the most sensitive group and should be given extra care in the form of an early soft tissue coverage and bone grafting. These patients should remain admitted in the hospital till all the operations are done, because once they are discharged, they have to wait a long time for readmission, a problem usually faced in the third world countries because of overcrowding in hospitals. These extremities ultimately developed deformity, shortening, and severe degree of stiffness of ankle and knee. Four out of these six extremities ultimately underwent secondary amputation. These six extremities had a MESS value of 5 or 6. Now, if they had been given extra points for severe irreparable soft tissue loss (whose coverage was impossible) and for nerve injury, they would have had a primary amputation (instead of carrying on with functionless limb for more than 1 year).
496
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
3.4. Nerve injuries Eight extremities (15%) had associated nerve injuries (common peroneal). As the nerves were crushed in all these patients, so no primary repair of the nerve was possible. No improvement was seen in the six extremities out of eight, which had a neurological deficit (despite MESS score of <7.) These eight extremities developed severe stiffness and deformities of ankle and knee, and resulted in an insensate and functionally useless extremity. Four limbs ultimately underwent secondary amputation. Crushing peripheral nerve injuries deserve an extra point in the MESS system as it saves the patient from carrying an anatomically aesthetic but functionally useless limb. 3.5. MESS in bilateral lower limb injuries We had six patients with bilateral mangled extremities. In each patient we did not add the points of shock because of one extremity to the other extremity. The less mangled extremities (with minimal amount of blood loss) had a MESS value of >4 and <7. If the points of shock had been added to these less mangled extremities, they would have been unnecessarily amputated. We suggest that MESS scoring should be done with caution in cases of bilateral mangled extremities. When the patient is in shock, the points for shock should not be added to the less mangled extremity. We also suggest that nerve injuries, severe crushing soft tissue injuries and irreparable soft tissue loss should be given an extra point each in the MESS system.
4. Conclusion MESS values of ≥7 are specific and found to have a positive predictive value of 100%. This relatively simple, readily available scoring system of objective criteria is highly accurate in acutely discriminating between limbs that
are salvageable and those that are unsalvageable and better managed by primary amputation. However, MESS system through an excellent tool to predict primary amputation was found lacking in predicting successful limb salvage and final functional outcome. Many extremities with a score <7 ultimately resulted in a secondary amputation or resulted in a functionally useless limb despite the patient undergoing prolonged and expensive reconstruction surgeries. MESS value of >4 and <7 is most sensitive. These patients should have early soft tissue coverage and an early operation for bone defect. We suggest that either the criteria of MESS value >7 as an indication for primary amputation should be lowered by 0.5 or 1 point so that futile salvage efforts to save a mangled extremity are prevented, or severe crushing soft tissue injuries, irreparable soft tissue loss and peripheral nerve injuries should be given an extra point each, so that the patient is saved from developing crush syndrome and/or uraemia and also from carrying a functionally useless limb. In bilateral cases, MESS value of each limb should be properly assessed (especially in shock), as the score may increase because of the other injured limb. References [1] Helfet DL, Howey T, Sanders R, Johansen K. Limb salvage versus amputation. Preliminary results of the mangled extremity severity score. Clin Orthop 1990;256:80–6. [2] Hansen Jr ST. The type IIIc tibial fractures. Salvage or amputation. J Bone Joint Surg 1987;69A:799–800. [3] Bondurant F, Colter HV, Buckle R, Cortchett PM, Browner BD. The medical and economic impact of severely injured lower extremities. J Trauma 1988;28:1270–3. [4] Gregory RT, Gould RJ, Peclet M. The mangled extremity syndrome. A severity grading system for multi-system injury of the extremity. J Trauma 1985;25:1147–50. [5] Hansen Jr ST. Overview of the severely traumatised lower limb. Reconstruction versus amputation. Clin Orthop 1989;247:17–9. [6] Robertson PA. Prediction of amputation after severe lower limb trauma. J Bone Joint Surg 1991;73B:816–8.
Critical evaluation of mangled extremity severity scoring system in Indian patients Sansar Sharma∗ , Ashish Devgan, K.M. Marya, Nitesh Rathee Department of Orthopaedics, Paraplegia and Rehabilitation, Postgraduate Institute of Medical Sciences, Rohtak 124001, Haryana, India Accepted 28 March 2002
Abstract Amputation of a mangled extremity is repugnant to the patient and the surgeon. However, prolonged unsuccessful attempts at salvage are costly, highly morbid and sometimes lethal. Much discussion has taken place regarding which criteria predict successful salvage, and predictive indices have been proposed in an attempt to identify limbs for which attempted salvage is unlikely to succeed. The mangled extremity severity score, or MESS system is the most thoroughly validated of the various classification systems, but at present there is no predictive scale that can be used with confidence to determine whether to amputate or attempt to salvage a mangled lower extremity. MESS system based on four significant criteria (with increasing points with worsening prognosis) i.e. skeletal injury, limb ischaemia, shock and patient age, has become a standard method to determine which one of the mangled extremities will eventually undergo amputation or salvage. Keeping in view the paucity of studies on Indian patients, a prospective trial of MESS was done in 50 patients who had 56 mangled extremities during the last 3 years. A significant difference between the MESS value of salvaged limbs (4.7) and amputated limbs (8.6) was found. MESS value of more than 7 was most specific and was found to have a positive predictive value of 100%. The results have been compared with Western literature and authors suggest that nerve injuries and irreparable soft tissue loss should be given an extra point each. In bilateral cases, the MESS value of each limb should be properly assessed (especially when patient is in shock), as the score may increase because of the other injured limb. © 2002 Elsevier Science Ltd. All rights reserved.
1. Introduction The management of massive upper and lower extremity trauma is a subject of considerable interest and controversy. The emergent management of these patients particularly those with vascular compromise poses a difficult decision for both the surgeon and the patient. The question of limb salvage versus primary amputation has been usually based on subjective clinical parameters rather than objective ones [1]. The decision to amputate has significant repercussions medically, economically, socially and medicolegally [2]. When amputation is inevitable, performing early surgery enhances patient survival, reduces pain, disability and shortens hospitalisation [3]. Gregory et al. in 1985 [4] were the first to propose a mangled extremity syndrome index for the predictability of amputation in a mangled extremity. For a long time, surgeons have had the technical ability to salvage most, if ∗ Corresponding author. Present address: 48/11-J, Medical Campus, Rohtak 124001, Haryana, India. E-mail address: [email protected] (S. Sharma).
not all, tibial fractures with vascular compromise. However, this is often “technique over reason” and often the end result is a physically, psychologically, financially and socially crippled patient with a useless salvaged limb [5]. Helfet et al. in 1990 [1] observed that the multiple grading systems were complex, not readily obtainable initially, the majority of patients did not fit the absolute criteria laid down for amputation and were based on retrospective study. Hence, they proposed a mangled extremity severity score (MESS) based on four variables i.e. skeletal/soft tissue injury (1–4 points), limb ischaemia (0–3 points), shock (0–2 points) and patient age (0–2 points). They concluded that this relatively simple, readily available scoring system of objective criteria was highly accurate in acutely discriminating between limbs that were salvageable to those that were unsalvageable and better managed by primary amputation. Observing the importance of the entity and paucity of any Indian study, we critically analysed the predictability of amputation or salvage in a mangled extremity by using the MESS in Indian patients.
0020-1383/02/$ – see front matter © 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 0 2 0 - 1 3 8 3 ( 0 2 ) 0 0 2 1 4 - 0
494
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
Table 1 Mangled extremity severity score [1] Type
Characteristics skeletal/soft tissue
Injuries
Points
1 2 3 4
Low energy Medium energy High energy Massive crush
Stab wounds, simple closed fractures, smaller-calibre gunshot wound Open or multiple-level fractures, dislocations, moderate crush injuries Shotgun blast (close range), high velocity gunshot wounds Logging, railroad, oil rig accidents
1 2 3 4
Shock group 1 Normotensive haemodynamics 2 Transiently hypotensive 3 Prolonged hypotension
BP stable in field and in OR BP unstable in field, but responsive to intravenous fluids Systolic BP <90 mmHg in field and responsive to intravenous fluid only in OR
0 1 2
Ischaemia 1 2 3 4
A pulsatile limb without signs of ischaemia Diminished pulses without signs of ischaemia No pulse by Doppler, sluggish capillary refill, paraesthesia, diminished motor activity Pulseless, cool, paralysed and numb limb without capillary refill
0a 1a 2a 3a
group None Mild Moderate Advanced
Age group (years) 1 <30 2 >30 3 >50
0 1 2
OR: operating room; BP: blood pressure. Amputation was advised if score was ≥7. Salvage was done if score was ≥6. a Points × 2 if ischaemia exceeds 6 h.
2. Material and methods
Table 2 Salvage procedures done in patients with MESS <7
Fifty consecutive patients with mangled extremities belonging to either sex and any age admitted to Pt. B.D. Sharma PGIMS, Rohtak were included in the study. Vitals were recorded and all resuscitative measures were instituted. Initial management of the mangled extremity was started in the form of thorough irrigation with copious normal saline, followed by meticulous debridement, pressure bandage, temporary splintage and antibiotics. MESS scoring was done, according to the Table 1. Primary fracture alignment, stabilisation and vascular repair if indicated, were carried out. Gradual delayed primary closure, split thickness skin grafting and fasciocutaneous flap coverage was undertaken as and when required (Table 2). Iliac bone grafting was undertaken in patients with primary bone loss or where fracture healing was delayed. Each patient was followed up at a regular interval of 2 weeks up to a minimum of 6 months and at each follow up patient was examined clinically and radiologically. Many patients, despite
Salvage procedure
No. of limbs (N = 56)
Fracture management External fixator/Illizarov POP cast Enders nail Unreamed tibial nail
38 9 7 2
Soft tissue management SSG Fasciocutaneous flap Myocutaneous flap Debridement and dressing
24 8 4 20
Vascular repair
4
having MESS values of more than 7, refused amputation primarily. In such patients we observed, whether they underwent secondary amputation and the final functional status of the salvaged limb (Table 3).
Table 3 Results at the end of follow up period End results
No. of limbs (N = 56)
Primary amputation (MESS ≥7)
16
Secondary amputation Refused consent for primary amputation (MESS ≥7 initially) Massive, crushing soft tissue injury (MESS <7 initially) Asensate and functionally useless limb (MESS <7 initially) Severe deformities, shortening and severe stiffness of knee and ankle (MESS <7 initially)
12 2 5 4
Average time between injury and amputation 1 day 9 3 11 18
months days months months
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
3. Results and discussion In the present study, there were 56 mangled extremities in 50 patients (44 males and 6 females). Roadside accident was the commonest mode of trauma. Injuries included in this series were Gustilo type IIIa, IIIb and IIIc involving fracture of both bones of leg, supracondylar femur and also crush injury of soft tissue. Thirty extremities had a Gustilo type IIIc injury. There was a significant difference in the mean MESS values; 4.7 in the limbs that were salvaged and 8.6 in the limbs that were amputated. This is almost the same as seen in the prospective study of Helfet et al. [1] in which the mean MESS values were 4.00 for salvaged limbs and 8.8 for amputated limbs. 3.1. Relevance of MESS value Out of 56 lower extremities, amputation was indicated in 28 extremities because the MESS value was ≥7. Primary amputation was done in 16 extremities and in 12 extremities (with MESS ≥7), consent for primary amputation was not given by the patient or by their attendants. Amputation is a big social stigma and repugnant to the patient as well as their relatives, in a largely agriculture based society of a developing country like India. Hence, they are reluctant for giving consent at the very outset after injury. All the 12 extremities, in which primary amputation was indicated (but refused initially), had a secondary amputation ultimately. The reasons for giving consent for secondary amputation were in the majority of cases to a functionally useless limb carrying the economic burden of repeated medical and surgical interventions like repeated debridements, dressings and costly antibiotics. The MESS value of ≥7 had a 100% predictable value for amputation. This is the same as seen in prospective study of Helfet et al. [1] in which there was 100% predictable value for amputation in extremities which had a MESS value of ≥7. Robertson [6] applied MESS to 152 patients with severely injured lower limbs and found that all the cases with a score of more than 7 required amputation; some with scores of <7 eventually came to amputation. The average hospital stay for each patient was 10 days in primary amputation and 28 days in secondary amputation. This shows the cost to each patient of secondary amputation is almost three times as compared to the patient who had a primary amputation, excluding the cost of his or her extra operations. This aspect is very important in the health care system of any third world country. 3.2. Salvage procedures—vascular repair Only in four extremities (7%), was vascular repair attempted. This is because majority of extremities with vascular injury had crushed vessels and many had also lost the ‘golden 6 h’ from injury to reporting in accident and emer-
495
gency department. In the two extremities, resection and end to end anastamosis of the popliteal artery was done. Two extremities had anterior and posterior tibial artery repair where the wound was clean and vessels were not crushed. The two extremities, in which a popliteal artery repair was done, showed improvement in circulation and were normal. The MESS value for these extremities was <7. On the other hand, the two extremities in which an anterior and posterior tibial artery repair was done, ultimately resulted in amputation. These two extremities had a MESS score >7. This shows the importance of the fact that vascular repair should never be attempted if the MESS value is ≥7. 3.3. Massive crush injury and irreparable soft tissue loss Two patients had massive crush injuries in a railway accident. But their MESS value was <7 on the account of their being normotensive, the limb fell in the mild ischaemic group and they were 18 and 19 years of age. Therefore, they were not advised to have a primary amputation. Unfortunately, both these patients began to develop features of crush syndrome and rising blood urea. Secondary amputation had to be carried out as a life saving procedure despite their initial MESS value of <7. Had they underwent primary amputation which was deferred initially because of their MESS value of <7, they might not have developed the early features of crush syndrome and uraemia. We suggest that severe, crushing soft tissue injury should be given an extra point in the MESS apart from being extra cautious to detect the earliest signs of crush syndrome and uraemia. Robertson [6] in 1991, in his series of 152 cases observed that in severely injured lower limbs, certain cases required amputation even when their MESS value was <7. In our series, there were six extremities (11%) that had a MESS value <7 (5 and 6) and were not advised to have an amputation. They required multiple operations for their bone and soft tissue defect like external fixator, Illizarov, skin grafting, free flaps, bone grafting and repeated debridements. Their mean hospital stay was 49 days (after multiple admissions). This is the most sensitive group and should be given extra care in the form of an early soft tissue coverage and bone grafting. These patients should remain admitted in the hospital till all the operations are done, because once they are discharged, they have to wait a long time for readmission, a problem usually faced in the third world countries because of overcrowding in hospitals. These extremities ultimately developed deformity, shortening, and severe degree of stiffness of ankle and knee. Four out of these six extremities ultimately underwent secondary amputation. These six extremities had a MESS value of 5 or 6. Now, if they had been given extra points for severe irreparable soft tissue loss (whose coverage was impossible) and for nerve injury, they would have had a primary amputation (instead of carrying on with functionless limb for more than 1 year).
496
S. Sharma et al. / Injury, Int. J. Care Injured 34 (2003) 493–496
3.4. Nerve injuries Eight extremities (15%) had associated nerve injuries (common peroneal). As the nerves were crushed in all these patients, so no primary repair of the nerve was possible. No improvement was seen in the six extremities out of eight, which had a neurological deficit (despite MESS score of <7.) These eight extremities developed severe stiffness and deformities of ankle and knee, and resulted in an insensate and functionally useless extremity. Four limbs ultimately underwent secondary amputation. Crushing peripheral nerve injuries deserve an extra point in the MESS system as it saves the patient from carrying an anatomically aesthetic but functionally useless limb. 3.5. MESS in bilateral lower limb injuries We had six patients with bilateral mangled extremities. In each patient we did not add the points of shock because of one extremity to the other extremity. The less mangled extremities (with minimal amount of blood loss) had a MESS value of >4 and <7. If the points of shock had been added to these less mangled extremities, they would have been unnecessarily amputated. We suggest that MESS scoring should be done with caution in cases of bilateral mangled extremities. When the patient is in shock, the points for shock should not be added to the less mangled extremity. We also suggest that nerve injuries, severe crushing soft tissue injuries and irreparable soft tissue loss should be given an extra point each in the MESS system.
4. Conclusion MESS values of ≥7 are specific and found to have a positive predictive value of 100%. This relatively simple, readily available scoring system of objective criteria is highly accurate in acutely discriminating between limbs that
are salvageable and those that are unsalvageable and better managed by primary amputation. However, MESS system through an excellent tool to predict primary amputation was found lacking in predicting successful limb salvage and final functional outcome. Many extremities with a score <7 ultimately resulted in a secondary amputation or resulted in a functionally useless limb despite the patient undergoing prolonged and expensive reconstruction surgeries. MESS value of >4 and <7 is most sensitive. These patients should have early soft tissue coverage and an early operation for bone defect. We suggest that either the criteria of MESS value >7 as an indication for primary amputation should be lowered by 0.5 or 1 point so that futile salvage efforts to save a mangled extremity are prevented, or severe crushing soft tissue injuries, irreparable soft tissue loss and peripheral nerve injuries should be given an extra point each, so that the patient is saved from developing crush syndrome and/or uraemia and also from carrying a functionally useless limb. In bilateral cases, MESS value of each limb should be properly assessed (especially in shock), as the score may increase because of the other injured limb. References [1] Helfet DL, Howey T, Sanders R, Johansen K. Limb salvage versus amputation. Preliminary results of the mangled extremity severity score. Clin Orthop 1990;256:80–6. [2] Hansen Jr ST. The type IIIc tibial fractures. Salvage or amputation. J Bone Joint Surg 1987;69A:799–800. [3] Bondurant F, Colter HV, Buckle R, Cortchett PM, Browner BD. The medical and economic impact of severely injured lower extremities. J Trauma 1988;28:1270–3. [4] Gregory RT, Gould RJ, Peclet M. The mangled extremity syndrome. A severity grading system for multi-system injury of the extremity. J Trauma 1985;25:1147–50. [5] Hansen Jr ST. Overview of the severely traumatised lower limb. Reconstruction versus amputation. Clin Orthop 1989;247:17–9. [6] Robertson PA. Prediction of amputation after severe lower limb trauma. J Bone Joint Surg 1991;73B:816–8.