Although the forearm is the site most frequently affected by compartment syndrome in the upper limb1-3, the low prevalence of forearm compartment syndrome makes it difficult to draw meaningful conclusions regarding etiology, optimal management, and outcome. The most common cause of forearm compartment syndrome in adults reported in the literature is a fracture of the distal end of the radius, although a substantial number of cases are associated with soft-tissue injuries1,4. Diagnosis often combines clinical signs with compartment pressure monitoring of the flexor forearm compartment1,2,4. Standard treatment includes early fasciotomy of the volar compartment, with concomitant decompression of the dorsal compartment and carpal tunnel as indicated2,5.
There is substantial morbidity associated with forearm compartment syndrome and subsequent fasciotomy6, with one recent systematic review noting a split-thickness skin-grafting rate of 61% and a complication rate of 42%4. Split-thickness skin-grafting of the forearm has notable cosmetic consequences for the patient6. Complications of forearm compartment syndrome include forearm contracture, loss of function, neurological deficits, delayed fracture union, and chronic pain2,4,7,8.
The aim of this study was to document the etiology, management, and outcome of acute forearm compartment syndrome treated with fasciotomy. We also aimed to determine the risk factors associated with the need for split-thickness skin-grafting for wound closure after fasciotomy, as well as the predictors associated with the development of complications.
From our trauma database, we identified all patients who were thirteen years or older with forearm fasciotomy over a twenty-two-year period from May 1988 to June 2010. This was classified as an audit under regional guidelines and did not require formal ethical board approval. Patients with a forearm fasciotomy for an acute compartment syndrome and patients with an associated crush syndrome were included. Patients who were seen with a missed or chronic compartment syndrome were excluded, as were patients who developed acute compartment syndrome after a primary vascular occlusion. With use of these criteria, 110 patients were identified. One patient had a concomitant compartment syndrome of the hand involving the interosseous compartments. All other patients had a compartment syndrome of only the forearm compartment.
Sufficient follow-up was defined as documentation in the medical records of a review at a minimum of three months after the fasciotomy to detect complications. Of the original 110 patients identified, twenty patients were excluded because of inadequate data and/or follow-up, leaving ninety patients (82%) who made up our study cohort for analysis. Of the twenty patients excluded, thirteen had inadequate follow-up, four lived outside our local catchment area and had inadequate data, and three died while in the hospital. No difference was detected between patients included in the cohort and the excluded group with regard to age (p = 0.06), sex (p = 0.66), or the number of those in whom the syndrome was associated with a fracture (p = 0.08), with open injuries (p = 0.35), or with the use of warfarin (p = 1.0). Fewer high-energy injuries were seen in the excluded cohort (p = 0.03).
We retrospectively reviewed medical records and recorded demographic data, including age, sex, and mechanism of injury. Crush injuries were categorized as either a crush syndrome with a prolonged ischemic time and an elevated serum creatinine kinase level or a high-energy crush injury of the forearm. High-energy injuries included a fall from a height, a motor vehicle collision, and a sports or crush injury. Causative fractures were recorded as a fracture of one or both bones in the forearm, with polytrauma defined as two or more fractures affecting multiple anatomical sites. The presence of an open fracture was also recorded.
Diagnosis
A clinical diagnosis of compartment syndrome was made if one or more signs were objectively present8. Signs included pain out of proportion to injury, pain on passive muscle stretch, excessive swelling, sensory disturbance, or motor abnormalities. Compartment pressure monitoring was used as a diagnostic adjunct in thirty-one patients (34%). Our method of monitoring used the continuous indwelling slit catheter (14-gauge, central venous catheter) technique, with placement in the affected compartment under an aseptic technique9. The volar compartment was the preferred location for monitoring. In the presence of an associated fracture, the tip of the catheter was placed at the level of the fracture2,10. Once in position, the catheter was flushed with use of normal saline solution and was attached to a blood pressure transducer with use of standard pressure manometry tubing9. A pressure difference (Δp = diastolic pressure – intracompartmental pressure) of ≤30 mm Hg for more than two hours was considered diagnostic of a compartment syndrome1,2,11.
Fasciotomy and Wound Closure: Technique
Time to fasciotomy was defined as the time period from admission to surgery. Crush syndrome injuries were not included in these analyses as it is difficult to define the onset of the diagnosis in these patients and muscle ischemia is usually established at the time of presentation. A satisfactory cutoff time to fasciotomy of less than or equal to six hours was chosen because of the evidence in previously published data on lower limb fasciotomy and outcome2,12-14.
All patients diagnosed as having an acute forearm compartment syndrome were treated with decompression of the affected forearm compartment(s). We used a standard technique with an incision extending from the biceps tendon to the palm of the hand, with or without decompression of the carpal tunnel as indicated. Carpal tunnel decompression was performed when clinical symptoms and signs indicative of median nerve compression were present and/or persistent severe swelling of the distal end of the forearm and wrist were noted intraoperatively. A fascial incision allowed a thorough inspection of the flexor compartment muscles. If this did not provide adequate decompression, an extensor compartment release was also performed through a direct dorsal incision. Inadequate decompression was defined as persistent swelling in the dorsal compartment despite release of the volar compartment and/or persistently raised intracompartmental pressures when measured intraoperatively. Muscle bulge at the time of fasciotomy was used to confirm the diagnosis. A thorough inspection of all muscle groups was performed, and an adequate debridement of all devitalized tissue was carried out. Discoloration, absence of bleeding, and absence of contractility on stimulation were used to determine muscle necrosis.
Fasciotomy wounds were covered with a sterile dressing, the forearm was immobilized in a splint in a position of function, and the wound was left open for forty-eight hours postoperatively. At this point, a second inspection was performed in the operating room to determine the viability of all tissues, with a further debridement of nonviable tissues performed as necessary. Attempted direct skin closure was performed if all muscle groups were satisfactory, with skin tension on closure avoided. If this was not possible, the patient underwent split-thickness skin-grafting. The decision regarding delayed wound closure or skin-grafting was determined on an individual patient basis.
Follow-up
Patients returned for follow-up examinations at our institution, which is the solitary provider of orthopaedic trauma care in the region. The mean follow-up period was eleven months (range, three to sixty months). Details on wound closure, complications, and subsequent surgical procedures were recorded at each visit.
Our main outcome measures were the use of split-thickness skin-grafting for fasciotomy wound closure and the development of long-term complications associated with forearm fasciotomy. Complications included the development of contracture; persistent neurological abnormalities, including motor and sensory disturbance of the forearm and hand; chronic pain; muscle necrosis; or delayed fracture union2,4,7,8. Delayed union was defined as a persistent absence of clinical and radiographic signs of union at the fracture site three months postoperatively. Radiographic union was defined as the bridging of three of the four cortices at the fracture site, as determined by anteroposterior and lateral radiographs. Complications that were associated solely with an underlying fracture or concomitant injury were excluded.
Statistical Methods
SPSS software (version 17.0; SPSS, Chicago, Illinois) was used for statistical analysis. Age was normally distributed. Time to fasciotomy had a skewed distribution. A Student unpaired t test was used to analyze parametric continuous data, with the Mann-Whitney U test used for nonparametric continuous data. Categorical binary data were analyzed with use of either the chi-square test or with the Fisher exact test when the observed frequency of cases in a cell of the contingency table was less than five. The Spearman correlation was used to determine the changing rate of complications in relation to time to fasciotomy. Two-tailed p values were reported, and significance was set at p = 0.05, with 95% confidence intervals (95% CI) presented with use of the modified Wald method for categorical data.
Source of Funding
No external funding source was received for this study.
The ninety patients in the study cohort had a mean age of thirty-three years (range, thirteen to eighty-one years), and there was a significant male predominance (eighty-two patients; 91%; 95% CI, 83% to 96%; p < 0.001). The mean age of the female patients was thirty-nine years (range, twenty-five to sixty-four years; 95% CI, twenty-seven to fifty-one years), which was not significantly different (p = 0.309) from the mean age of the male patients (thirty-three years; range, thirteen to eight-one years; 95% CI, twenty-nine to thirty-seven years) at the time of injury.
The most frequently seen mechanism of injury was a motor vehicle collision, followed by a fall from a height and sports injuries (Table I). Crush injuries (nine patients) and crush syndromes (nine patients) each accounted for 10% of all patients. High-energy injuries were more frequently seen, accounting for 63% (fifty-seven patients). The mean age of the patients who sustained a high-energy injury (twenty-nine years; 95% CI, twenty-five to thirty-three years) was significantly younger (p < 0.001) than those who sustained a low-energy injury (forty-one years, 95% CI, thirty-four to forty-eight years).
A fracture of one or both of the forearm bones had occurred in sixty-two patients (69%), with soft-tissue injuries only in twenty-eight (31%). The mean age of the patients who sustained a fracture (twenty-nine years; 95% CI, twenty-six to thirty-two years) was significantly younger (p < 0.001) than that of the patients who sustained a soft-tissue injury (forty-four years; 95% CI, thirty-seven to fifty-one years). An isolated distal radial fracture was the most frequent fracture (thirty-one patients; 34%), followed by radial and ulnar diaphyseal fractures (twenty-seven patients; 30%) (Table I).
A diagnosis of compartment syndrome was made with use of clinical signs alone in fifty-nine patients (66%). Swelling was present in all of our patients. Pain was documented in 79% of the patients (Table I) because of a decision made at the time of definitive fixation to proceed to fasciotomy. Sensory disturbance was present in 52% of the patients, with motor symptoms seen in only 9% of the patients. Compartment pressure monitoring was used in combination with clinical signs in thirty-one patients (34%).
The median time to fasciotomy in eighty-one patients was twelve hours (two to seventy-two hours). The time to fasciotomy was significantly lower in polytrauma patients (13.3 hours; range, two to forty-six hours; 95% CI, 8.8 to eighteen hours) than in patients with an isolated fracture or soft-tissue injury (20.2 hours; range, two to seventy-two hours; 95% CI, sixteen to twenty-five hours) (p = 0.033). A volar compartment decompression was performed most frequently (eighty-nine patients; 99%), with only one patient undergoing an isolated dorsal decompression because of a hematoma (Table I). An associated carpal tunnel decompression was performed in forty-nine patients (54%).
Split-Thickness Skin-Grafting
Fifty-two patients (58%) underwent split-thickness skin-grafting to achieve wound closure (Table II). The mean age of those undergoing grafting was significantly younger than those who achieved direct closure (p = 0.005). No difference in sex predominance was seen between either group. The mechanism of injury was predictive (p = 0.035), with eight of nine patients who sustained crush injuries requiring grafting. None of the five patients who sustained the injury in relation to warfarin therapy underwent grafting. Fractures, polytrauma, time to fasciotomy, and compartments released had no influence on the necessity for split-thickness skin-grafting for wound closure.
Complications
Twenty-nine patients (32%) developed complications associated with acute forearm compartment syndrome (Table III). A neurological deficit was the most common complication (sixteen patients; 18%), followed by contracture, delayed fracture union, and muscle necrosis. No association with age, sex, or mechanism of injury was found (Table IV). The mean time to fasciotomy was significantly greater in those who sustained complications (p = 0.044), with patients undergoing fasciotomy at greater than six hours after presentation (twenty-two of twenty-five patients; 88%) significantly more likely to develop complications (p = 0.018) (Table V). As the time to fasciotomy increased, the rate of complications increased (r = 0.23, p = 0.044). The presence of impaired neurological motor function prior to fasciotomy was approaching significance (p = 0.068) in predicting complications. Fracture, polytrauma, compartments released, and method of wound closure had no influence on the development of complications.
To our knowledge, this is the largest series in the literature on acute forearm compartment syndrome, with the etiology, diagnosis, management, and complications reported for a consecutive group of patients. We observed a complication rate of 32% and demonstrated that a delay in the time to fasciotomy was predictive of the development of long-term complications. These findings are analogous with the literature for lower-limb compartment syndrome that has shown that time to fasciotomy influences outcome, with the critical time period ranging from six to twelve hours11,14-17. This emphasizes the importance of a prompt diagnosis for all patients with a suspected acute forearm compartment syndrome, with urgent fasciotomy of all affected compartments.
The diagnosis of forearm compartment syndrome often requires a combination of clinical signs and compartment pressure monitoring, with a recent review finding that monitoring of the forearm is only used approximately 50% of the time1,2,4. As would be expected, swelling was noted in all of our patients. We suggest that this is the only reliable clinical sign, given that pain was present in only 79% of the patients and neurological symptoms in even less. Only a third of the patients in our series underwent diagnostic compartment pressure monitoring as this became protocol for the latter half of the study period following new research findings in the unit1. Although rarely seen, positive motor symptoms before fasciotomy were approaching significance in terms of determining complications after surgery, as these have been shown to influence the outcome in patients with lower-limb compartment syndrome17,18. It is intuitive that this would be the case, although there may be difficulty in determining the presence of such signs in a trauma patient who may have limited motor function because of pain19.
Given the necessity for a timely diagnosis, combined with the variable etiology and clinical signs that we have shown to be associated with the presentation, we recommend compartment pressure monitoring in all patients with a suspected acute forearm compartment syndrome. The limited diagnostic value of clinical signs in the diagnosis of lower-limb compartment syndrome has a sensitivity ranging from 13% to 19%20. Furthermore, monitoring has been shown to reduce the time to fasciotomy, and thus subsequent complications, in tibial fractures15.
A mean age of thirty-three years for our patient cohort is comparable with that in the literature1,21,22. McQueen et al. found that patients under the age of thirty-five years with a distal radial fracture were at a significantly increased risk of developing compartment syndrome of the forearm compared with those over thirty-five years1. They also found a male predominance, as we and others have demonstrated1,4,23. We found that the most common cause of acute forearm compartment syndrome was a fracture of the distal end of the radius, accounting for a third of all patients1,4,21. However, although compartment syndrome is clinically associated with fractures, it is important to appreciate that almost a third of the cases arise in the absence of a forearm fracture4. As with our series, there can be a disparate selection of causes, including include crush injuries, crush syndrome, drug overdose, penetrating injuries (stab and injection), arterial injuries, and anticoagulation1,7,22,24,25. Acute compartment syndrome in the absence of fracture has been associated with a delay to diagnosis and fasciotomy8. Given these variable presentations, a high index of suspicion is necessary in young male patients with high-energy forearm injuries, with or without an associated fracture, as well as in patients with soft-tissue swelling suggestive of forearm compartment syndrome, irrespective of age, sex, or causality.
There is a noted morbidity attached to forearm compartment syndrome and subsequent fasciotomy, with split-thickness skin-grafting having a notable effect on the cosmetic and functional outcome for the patient6. Kalyani et al. carried out a systematic review of the literature on forearm compartment syndrome and found a split-thickness skin-grafting rate of 61%, which is comparable with our rate of 58%4. We found that younger age and mechanism of injury were predictive of the need for a split-thickness skin graft for wound closure. Younger age is predictive most likely because of the increased muscle bulk of the patient, making delayed closure more difficult to achieve without skin tension. The mechanism of injury, in particular a crush injury, was associated with the need for split-thickness skin-grafting. When warfarin therapy was causative, this was predictive of no requirement for the use of split-thickness skin-grafting. This is presumably because once fasciotomy, evacuation of clot, and hemostasis are achieved, delayed closure is possible. Documented complications following forearm compartment syndrome include forearm contractures, muscle necrosis, neurological deficits, fracture nonunion, and chronic pain2,4,7,8. The rate of complications of 32% in those studies is marginally less than the rate of 42% found in the systematic review by Kalyani et al.4. However, neurological complications were most frequently seen in both the present study and that by Kalyani et al, which had comparable rates of 18% and 21%, respectively. Four patients in our study had a delayed fracture union, which occurs also when tibial fractures are complicated by compartment syndrome26.
We acknowledge that a limitation of our study is the recognized degree of inaccuracy in determining the exact time to fasciotomy, although we used an accepted method8. Furthermore, although we identified a clear relationship between time to fasciotomy and the rate of complications, the assumption of less than six hours is based on the limited available literature2,11-13. We documented risk factors associated with both skin-grafting and complications; however, with larger numbers, other variables may have been significant.
In conclusion, acute forearm compartment syndrome requiring fasciotomy predominantly affects males and can occur following either a forearm fracture or soft-tissue injury. We recommend compartment monitoring in all patients with risk factors and clinical signs suggestive of acute compartment syndrome. Age and mechanism of injury are important predictors of the requirement for skin-grafting for wound closure, which is necessary in almost two-thirds of patients. Complications occur in a third of patients and are associated with a delay in the time to fasciotomy.
Note: The authors thank the Scottish Orthopaedic Research Trust into Trauma (SORT-IT) for their assistance in performing this study.
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.