Mangled lower extremity: can we trust the amputation scores?

Abstract

Background

Limb injuries represent a constant and severe problem. Several lower limb injuries are more frequent than upper limb injuries. Over time, in an attempt to quantify the severity of traumas and to establish guidelines for the decision whether to save or amputate a mangled extremity, several scoring systems have been reported. Most refer to bone fractures, soft tissue damage, vascular, nerves and tendon lesions.

Matherials and methods

Articles dealing with mangled lower extremities published in the last 15 years were analyzed. Other inclusion criteriaincluded:articles reporting MESS, PSI, LSI, and Gustillo-Anderson scores, studies based on groups of more than 25 patients, and English language articles. We tried to determine if there was good correlation between amputation recommendations and various scores of injury, with regard to combat wounds and civilian injuries, in adult and pediatric groups.

Results

Thirty-two papers fulfilled our criteria; in 17 of these, correlation between mangled extremity scores and the decision to amputate or salvage the limb was well-defined. Good correlation between MESS and amputation was found in 25% of the papers. The highest correlation was found for pediatric injuries and combined adult and pediatric combat injuries.

Conclusions

The mangled extremity is a long-lasting, unsolved problem, with much debate and a large number of protocols and scoring systems, but with no unanimously-accepted solution. Many mangled extremities are borderline cases, and the decision to amputate or to salvage a limb must be carefully assessed. With advances in the medical field over the last 15 years, more mangled lower extremities are salvaged, especially in civilian injuries.

Introduction

Over 100 million people visit annually emergency departments in the USA, with about 36% of the visits to trauma centers [1]. Most severe extremities injuries are encountered during wartime [2-5], but even in quotidian life limb injuries represent a constant and severe problem. The rate of limb injuries has been increasing over the years, particularly accidental injuries; this trend can be attributed to modernization, industrialization, and an increased rate of violence in society. Except for war injuries, the most frequent causes leading to severe limb traumas are road traffic accidents and work related accidents [6].

The three most frequent mechanisms responsible for these types of injuries are: a) Direct force, as a primary mechanism; b) Injuries produced by bone fragment mobilization, as a secondary mechanism; c) Third degree burns, as a tertiary mechanism [7].

Most patients with severe mangled extremities are aged 20-39 years and are predominantly male [8]. Lower extremity injuries are more frequent than upper extremity injuries in civilians. Among lower extremity injuries, tibia and fibula fractures are the most common injury, occurring in about 40% of cases, while vascular injuries are reported to be as high as 48% [9,10].

Over time, in an attempt to quantify the severity of traumas and to establish guidelines for decision-making, whether to save or to amputate the mangled extremity, several scoring systems have been developed. Most incorporate bone fractures, soft tissue damage, vascular, nerve and tendon lesions.

The Mangled Extremity Severity Score (MESS) is probably the most common scoring system used [11] (Table 1), followed by the Predictive Salvage Index (PSI) [12] (Table 2), Limb Salvage Index (LSI) [13] (Table 3), Mangled Extremity Syndrome Index (MESI), Nerve injury, ischemia, soft tissue, skeletal injury, shock, age of patient score (NISSSA), and the Hannover Fracture Scale [14,15].

Table 1.

Mangled Extremity Severity Score (MESS) [11]

Skeletal/soft tissue injury

Low energy injury (eg. simple bone fracture) - 1 point

Medium energy injury (eg. multiple bone fractures) - 2 points

High energy injury (eg. car accidents) - 3 points

Very high energy injury (eg. high speed trauma with severe contamination) - 4 points

Limb ischemia

Normal perfusion with reduces or even absent pulse - 1xpoint

Absent pulse,paresthesia, diminished capillary refill - 2points

Cool, paralyzed, insensate limb - 3xpoints

Shock

Systolic blood pressure > 90 mm Hg: 0 points

Hypotensive transiently: 1 point

Hypotensive persistent: 2 points

Age

< 30 years: 0 points

30-50 years: 1 point

> 50 years: 2 points

^xThe score is doubled for ischemia > 6 hours

Table 2.

Predictive Salvage Index (PSI) [12]

Bone Injury
Mild trauma	1
Moderate trauma	2
Severe trauma	3
Muscle Injury
Mild trauma	1
Moderate trauma	2
Severe trauma	3
Arterial Injury
Suprapopliteal arteries	1
Popliteal artery	2
Infrapopliteal arteries	3
Delay to theatre
less than 6h	1
6-12h	2
More than 12h	3

Table 3.

Limb Salvage Index (LSI) [13]

Arterial trauma

Contusion (with no thrombosis), palpable pulses: 0 points

Pulseless femoral or popliteal vessels, thrombosis, occlusion of 2 or more shank vessels,: 1 point

Complete occlusion of femoral, popliteal or all 3 shank vessels: 2 points

Nerve trauma

Contusion or elongation of the femoral, tibial or peroneal nerve: 0 points

Partial transection of the sciatic, femoral, peroneal or tibial nerve or even complete transaction of the femoral, peroneal or tibial nerve: 1 point

Complete transection of the sciatic nerve or of both peroneal and tibial nerves: 2 points

Bone trauma

Closed fracture in no more than two sites or open fracture without comminution, fibula fracture or open joint without foreign body: 0 points

Closed fracture in at least three sites or open fracture with comminution or open joint with foreign body or bone loss less than 3 cm: 1 point

Bone loss more than 3 cm; type IIIB, C Gustilo fractures: 2 points

Skin trauma

Clean laceration with primary repair or 1st degree burn: 0 points

Delayed closure due to contamination or wounds requiring skin grafts or flaps or 2nd and 3rd degree burns: 1 point

Muscle trauma

One muscle or tendon avulsion or laceration: 0 points

Two or more muscles or tendons laceration or avulsion : 1 point

Crush injury: 2 points

Deep vein trauma

Contusion, partial laceration or avulsion; complete laceration or avulsion with intact drainage; superficial vein injury: 0 points

Complete laceration, avulsion, or thrombosis without adequate venous drainage: 1 point

Warm ischemia time

< 6 h: 0 points

6-9 h:1 point

9-12 h: 2 points

12-15 h: 3 points

> 15 h: 4 points

PubMed provides numerous articles dealing with methods of predicting results for mangled extremities. Most extremity injury scoring systems were developed over 15 years ago. Orthopedic, plastic, and vascular surgery techniques and strategies have changed dramatically since then.

Materials and methods

The goal of this review was to evaluate the various scoring systems used and published recently. We selected those that used MESS as a first choice, along with PSI, LSI, and Gustillo-Anderson. The studies included in our review met the following criteria: articles dealing with mangled lower extremity; articles reporting MESS, PSI, LSI, or Gustillo-Anderson scores; articles published since 1995; studies based on groups with more than 25 cases; articles published in English in PubMed.

Results

Thirty-two articles met the above-mentioned criteria. In 17, the correlation between the mangled extremity scores and the decision whether to amputate or salvage the limb was well-defined. In all of these articles, the authors used MESS as a scoring system, while LSI was found in four studies, PSI in three, and MESI in three.

Of the 17 studies that fulfilled our inclusion criteria, three were related to war injuries, two were related to severe injuries in children, and the rest were based on civilian injuries, both in adults and children. Eight of the 17 articles reported good correlation between MESS and the amputation decision. Both articles describing children with mangled extremities showed good correlation, as did two of the three studies on combat injuries. The remaining nine articles did not find MESS helpful in the decision whether to amputate or salvage a limb.

The results were categorised into three main groups: a) Adults and children-civilian injuries-this group was not split into two (adults and children) as the reports did not specify the age of patients included in each category; b) Children-civilian; c) Combat injuries.

Civilian injuries (adults and children)

In a prospective study of 46 upper and lower extremities with MESS injuries scoring higher than 7, Elsharawy [16] was able to save 43 (93%), a specificity of 27.5% for MESS regarding secondary amputations. In agreement with Elsharawy, Menakuru [17] managed to salvage the limb in 20 (69%) of 29 patients with MESS>7 (Table 4). Elsharawy [16] excluded patients who underwent primary amputation (28 cases, 31%) from the study. Primary amputation was defined as limbs amputated as the primary treatment modality. The possibility of salvaging the limb was not considered because the limb was virtually amputated, having only a small bridge of tissue in connection with the proximal stump, or the limb had a long ischemia time.

Table 4.

Literature review on MESS >7

Publishing year	Authors	Limbs	MESS>7 amputation	MESS>7 salvaged
1996	Rodney	51	21	16%(4)
1997	O'Sullivan	54	-	-
2001	Bosse	556	68	34.60% (36)
2002**	Fagelman	52	5	0%
2003	Sansar Sharma	56	28	0%
2005	Menakuru	148#	9	68.90% (20)
2005	Elsharawy	62	3	93.40% (43)
2005	Kumar	61	10	9.09% (1)
2007*	LTC Robert	60#	7	12.50% (1)
2009	Callcut	36	5	-
2009	Korompilias	63#	7	0%
2009*	Brown	86	18	35.71% (10)
2010**	Mommsen	44	8	50% (4)

^*Combat injuries;

^**Children injuries;

^#upper and lower extremities

On the other hand, some reports described good correlation between MESS>7 and amputation [18-23]. In a study on 56 limb injuries, Sharma [22] reported good correlation between MESS>7 and amputation. He did not try a salvage procedure in any case with a MESS higher than 7. Likewise, Korompilias [24] amputated all limbs with MESS>7.

Kumar [21] published a study on 58 cases, including a retrospective study on 25 cases, with 11 injured limbs presenting a MESS score higher than 7. All the limbs in the retrospective group had been amputated (four cases had primary amputation, and one case had secondary amputation), and five of six cases had been amputated with no details about primary or secondary amputation.

The reports for primary amputation for MESS>7 vary from 0% [24] to 41% [25]. Korompilias [24] analyzed 10 cases of massive extremity injuries in which an attempt was made to salvage the limbs. Three patients died and the others were amputated within 15 days of initial salvage. In the interim, all suffered multiple reconstruction techniques and debridements. In a study on 51 limbs published in 1996, Durham [25] found a primary amputation rate of 41.1% and a secondary amputation rate of 11.7%, with a mean MESS score of 8.8 and 21 limbs with MESS >7. The rate of secondary amputation reported ranged from 1.8% [19] to 15.6% [26] (Table 5).

Table 5.

Primary and secondary amputation rates

Year	Authors	Limbs	No. of amputated limbs	Primary amputation		Secondary amputation
				No.	%	No.	%
1996	Durham	51	27	21	41,1	6	11,7
1997	O'Sullivan	54	22	15	27.7	7	12.9
2001	Bosse	556	149	63	11.3	86	15.4
2002**	Fagelman	52	12	12***	23	0	0
2003	Sharma	56	39	16	28.5	23	41
2005	Menakuru	148#		-	-	9#	6
2005	Kumar	61	11	7	11,4	4	6.55
2005	Elsharawy	95#		28#	29.4
2006	Rajasekaran	109	7	5	4.5	2	1.8
2007*	Rush	60#	8#	8	13.3	0	0
2009	Callcut	36	6	2	5.5	4	11.1
2009	Korompilias	63#	7#	0	0	7 (4 LE)	11.1
2009*	Brown	86	22	15	17.4	7	8.1
2009*	Gifford	TVS 64	12	2	3.1	10	15.6
		Control 61	14	7	11.4	7	11.4
2010**	Mommsen	44	8	3	6.8	5	11.3

^*Combat trauma;

^**Children trauma;

^***Primary amputation was defined as amputation during the initial hospital stay;

^#upper and lower limbs;

^-Patients who underwent primary amputation were not included in the study;

LE = lower extremities; TVS = temporary vascular shunt.

Children - civilian

There are some reports on combat mangled extremities in children, but the articles did not make a clear separation between child and adult injuries. This category is discussed in section III.

The English literature is poor in reporting on mangled extremity injuries in children. Most of the studies involving children found good correlation between MESS and amputation. In his study on 44 children, Mommsen [27] reported good correlation between MESS and limb salvage or amputation. In a retrospective study on 36 children, Fagelman [28] evaluated the correlation between MESS score and grade IIIB and C lower extremity fractures and found an accurate prediction in 93% of cases.

Combat injuries

Some studies that treat mangled lower extremities in combat situations found good correlation between MESS>7 and amputation. In a study involving 60 limb injuries in combat settings in Iraq and Afghanistan, Rush [23] validated the utility of the MESS score. Most amputations were performed on young patients with an ischemic limb and with a general health status that precluded lengthy reconstructions [21]. In another study, Brown [29] encountered 77 military patients from Iraq and Afghanistan with 85 mangled extremities and also found good correlation between prolonged ischemia time, hypotension, unstable general condition, and amputation. Seventy-four percent of the limbs were salvaged and 26% were amputated, 18% as primary amputation and 8% as secondary amputation. The authors concluded that MESS did not help in the decision as to whether or not to amputate. Ten limbs with MESS >7 were successfully salvaged.

For primary amputation in combat situations, the results range from 3.1% [26] to 17.4% [21], while the range was between 0% [21] and 15.6% [26] for secondary amputation (Table 5). In his study, Gifford [26] compared a group of patients who had a temporary vascular shunt (TVS) with a control group with similar characteristics but without temporary vascular shunts. The TVS group had 3% primary amputations and 16% secondary amputations, while the control group had 12% primary amputations and 12% secondary amputations. These results suggested the possible benefit of the TVS, although the results were not found to be statistically significant.

The largest study reporting lower extremity injury severity score was reported by Bosse [30]. He evaluated 556 lower extremities by using five scoring systems and found that 14.5% of patients who did not have an indication for amputation according to their MESS score, underwent amputation in fact. The authors found that LSI had better specificity than PSI, MESS and NISSSA. The MESS had 69.9% specificity and 78% sensitivity. In a study on 54 limbs in 51 patients, O’Sullivan [18] found that MESS and LSI are not predictive for amputation in limbs with Gustillo IIIB and C injuries.

Discussion

Because many mangled extremities are borderline cases with an unpredictable prognosis, the decision to amputate or to salvage a limb must be carefully assessed. Unless the situation is life-threatening, the future of a limb should not be decided on the basis of the initial case evaluation alone. The mangled extremity scoring systems that are currently used were developed more than 15 years ago. Since then, significant advances have been made in surgical techniques and devices, in the intensive care field, in stabilization methods and in reconstructions, all of which now permit limb salvage in the majority of lower limb trauma cases. Unfortunately, although the operation is usually deemed a success, there are cases that require secondary amputation. Failed attempts at limb salvage result in prolonged hospitalization, along with multiple surgical procedures, pain, and psychological trauma.

Although most recent studies agree that indications for limb amputation have diminished, there are authors who do not agree with performing a salvage operation for patients with an MESS higher than 7. As the results revealed, there are major differences even among publications in the same year. For example, Elsharawy [16] saved 93.4% of limbs with MESS >7 and Kumar [21] had a salvage rate ten times lower (9.09%), although the number of cases in these studies is almost equal (62 and 61, respectively). This can be explained by the inclusion and exclusion criteria, as well as by the different type of studies (prospective versus prospective plus retrospective).

In almost all combat studies with a large number of cases, MESS is the most used scoring system, due to its simplicity. Because most soldiers are under 30 years old, shock and ischemic time are the most important factors when calculating MESS in a combat casualty situation. “Life before limb” should be respected when treating severely mangled extremity injuries. In combat situations, lower limb injuries are frequently associated with other organ injuries, which are sometimes life-threatening. That explains why some authors prefer to apply a tourniquet on a limb with MESS >7 and amputate in critical situations. Most reports agree with amputations for combat limb injuries with MESS >7.

When addressing MESS prediction in children, all the studies reported good correlation between MESS and limb salvage or amputation. This may be explained by the fact that patients younger than 30 years of age receive no points on MESS. The literature has only a small number of studies referring to only a small number of cases of children with mangled extremities. Children have a better outcome compared with adults and have a lower rate of delayed union or osteomyelitis [31-33] after lower limb injuries.

In conclusion, we must note that the last two decades have seen advances in reconstructive techniques, combined with good collaboration between plastic surgeons, orthopedic surgeons, and vascular surgeons, that has made a difference in terms of limb salvage, as well as secondary reconstruction [24,34].

In his study on 556 limbs, Bosse [30] did not validate the clinical utility of any of the lower-extremity injury-severity scores. We agree that it is better, as a first step, to attempt to salvage the limb; if it proves to be unsalvageable, a secondary amputation should be performed. However, technical viability is not a sufficient criterion for limb salvage [35]. The growing enthusiasm for microvascular surgery may lead to death, sepsis, and preservation of dysfunctional limbs, as well as higher adjusted hospital charges. Those patients who underwent successful limb salvage procedures had more complications, more complex operations, more operative procedures, and longer hospitalizations than patients who underwent early amputation [36]. Unfortunately, a salvaged limb does not guarantee functionality, normal life, a pain-free extremity, or employability. It is important for the patient and his/her family to understand that neither a salvage procedure nor an amputation will guarantee a return to the previous normal extremity. This is why a prediction score alone should not make the decision for amputation or salvage procedure. The final decision should also take into account future functionality, available recovery programs, the patient’s demeanor and, as a final criterion, the surgeon’s enthusiasm and skill.