Preliminary comparative study of lower extremity pressure measurements under the conditions using former models and new lithotomy stirrups in rectal cancer surgery.

BACKGROUND: This study aimed to investigate the effect of the use of new lithotomy stirrups-2 on the pressure dispersal on lower limbs, which may lead to the prevention of well-leg compartment syndrome (WLCS) and deep venous thrombosis (DVT), which are the most commonly associated adverse events with laparoscopic and robot-assisted rectal surgery. METHODS: A total of 30 healthy participants were included in this study. The pressure (mmHg) applied on various lower limb muscles when using conventional lithotomy stirrups-1 and new type stirrups-2 was recorded in various lithotomy positions; 1) neutral position, 2) Trendelenburg position (15°) with a 0° right inferior tilt, and 3) Trendelenburg position (15°) with a 10° right inferior tilt. Using a special sensor pad named Palm Q®, and the average values were compared between two types of stirrups. RESULTS: The use of new lithotomy stirrups-2 significantly reduced the pressure applied on the lower limb muscles in various lithotomy positions compared with the use of lithotomy stirrups-1. The most pressured lower limb muscle when using both lithotomy stirrups was the central soleus muscle, which is the most common site for the development of WLCS and DVT. In addition, when using the conventional lithotomy stirrups-1, the pressure was predominantly applied to the proximal soleus muscle; however, when using lithotomy stirrups-2, the pressure was shifted to the more distal soleus muscle. CONCLUSION: These results suggest that the new lithotomy stirrups-2 is useful in reducing the pressure load on leg muscles, especially on the proximal to central soleus, and may reduce the incidence of WLCS and DVT after rectal surgery performed in the lithotomy position. Further clinical studies are needed to determine whether the use of lithotomy stirrups-2 prevents these complications in various clinical settings.

Risk factors for poor outcomes in patients with acute lower leg compartment syndrome: a retrospective study of 103 cases.

PURPOSE: The primary aim of this study was to investigate the risk factors associated with poor outcomes following acute compartment syndrome (ACS) of lower leg. The secondary objective was to determine if delayed fasciotomy is linked to poor outcomes. METHODS: In this retrospective case control study approved by the institutional review board, we identified 103 patients with ACS of the lower leg. Poor outcome was defined as a composite variable that included limb amputation, neurological deficit and contracture. Among these, 44 patients exhibited poor outcome while 59 patients demonstrated a good outcome. Patient-related factors, laboratory values, and treatment-related factors were analyzed using electronic medical records. Univariate statistical and logistic regression analyses were conducted to determine significance. RESULTS: Bivariate analyses showed that the mechanism of injury (P = 0.021), open injury (P = 0.001), arterial injury (P<0.001), hemoglobin levels (HB) (P < 0.001), white blood cell count (WBC) (P = 0.008), albumin levels (ALB) (P<0.001), creatine kinase levels (CK) at presentation (P = 0.015), CK at peak (P<0.001), creatine kinase levels (Ca) (P = 0.004), dehydrating agent (P = 0.036), and debridement (P = 0.005) were found to be associated with the risk of poor outcomes. Logistic regression analyses revealed that arterial injury [ P< 0.001, OR = 66.172, 95% CI (10.536, 415.611)] was an independent risk factor for poor outcomes. However, HB [P = 0.005, OR = 0.934, 95% CI (0.891, 0.979)] was a protective factor against poor outcomes. Receiver operating characteristic (ROC) curve analysis showed that the cut-off values of HB to prevent poor outcome following ACS was 102.45 g/L. CONCLUSIONS: ACS of the lower leg is a serious complication often associated with a poor prognosis. Patients with arterial injury or lower HB have a significantly increased risk of having poor outcomes. Poor outcomes were not found to be associated with the timing of fasciotomy in this study.

Delayed onset of neonatal compartment syndrome associated with compound fetal presentation.

Neonatal compartment syndrome, although rare, has a classic presentation with sentinel skin findings and development of swelling, erythema, and tenderness of the affected extremity. Neonatal compartment syndrome requires prompt surgical intervention to preserve the affected limb and ensure its normal growth and development. Our patient was born at term via vaginal delivery complicated by a compound presentation involving the left upper extremity. No physical exam abnormalities were noted at birth, but she developed signs of neonatal compartment syndrome by 15 h of life. She was surgically treated at 22 h of life and recovered well. At one year of age, she has normal growth and function of the affected extremity. Our case adds to the growing literature associating neonatal compartment syndrome with a compound fetal presentation.

Acute compartment syndrome and fasciotomy after a viper bite in Italy: a case report.

BACKGROUND: Bites caused by European vipers are rare medical emergencies but can occasionally cause life-threatening complications. Viper venom causes local symptoms, which can be accompanied by systemic manifestations in severe cases. The local effects of snakebites include edema and, more rarely, necrosis and compartment syndrome. The consequences of envenomation are often more pronounced in children due to their smaller body size. CASE PRESENTATION: We present the case of a 6-year-old girl who experienced multiple viper bites in the lower limb in northwest Italy. The girl received supportive care but progressed to develop compartment syndrome that required emergency fasciotomy. The patient's condition improved promptly after surgical decompression and administration of antivenom, but full recovery required prolonged hospitalization and rehabilitation. CONCLUSIONS: This case highlights the importance of obtaining a timely assessment of the severity of viper envenomation without delaying the administration of antivenom in most serious cases. The presence of multiple bite marks on the patient is one factor that may help to predict the clinical severity of snakebites and anticipate symptom progression.

Acute lumbar paraspinal compartment syndrome after radical cystectomy.

Lumbar paraspinal compartment syndrome (LPCS) is a rare diagnosis, seen in patients chronically after repeated lumbar trauma or acutely in a postoperative setting. Only a dozen cases are documented worldwide, and to date no clinical guidelines exist for the diagnosis nor the treatment.We describe the case of a 44-year-old man with excruciating lower back pain following a radical cystectomy. The postoperative laboratory values were compatible with acute rhabdomyolysis. The lumbar spine MRI showed necrosis of lumbosacral paraspinal muscles, making the diagnosis of acute LPCS. After seeking advice from different specialists, the conservative approach was chosen with combined pain treatment and physiotherapy. The patient is currently still disabled for some tasks and needs chronic pain medication.

Identifying key risk factors for acute compartment syndrome in tibial diaphysis fracture patients.

Acute compartment syndrome (ACS) is a severe orthopedic issue that, if left untreated, can result in lasting nerve and muscle damage or even necessitate amputation. The association between admission laboratory blood test indicators and the occurrence of ACS in patients with tibial diaphysis fractures is currently a subject of debate. The objective of this research was to identify the contributing factors for ACS in individuals suffering from tibial diaphysis fractures. In this retrospective study, we collected data on a total of 705 individuals from our hospital, comprising 86 ACS patients and 619 non-ACS patients with tibial diaphysis fractures. These participants were categorized into two distinct groups: the ACS group and the non-ACS group. Despite the inherent limitations associated with retrospective analyses, such as potential biases in data collection and interpretation, we conducted a comprehensive analysis of demographics, comorbidities, and admission lab results. Our analytical approach included univariate analysis, logistic regression, and receiver operating characteristic (ROC) curve analysis techniques, aiming to mitigate these limitations and provide robust findings. The statistical analysis revealed several predictors of ACS, including gender (p = 0.011, OR = 3.200), crush injuries (p = 0.004, OR = 4.622), lactic dehydrogenase (LDH) levels (p < 0.001, OR = 1.003), and white blood cell (WBC) count (p < 0.001, OR = 1.246). Interestingly, the study also found that certain factors, such as falls on the same level (p = 0.007, OR = 0.334) and cholinesterase (CHE) levels (p < 0.001, OR = 0.721), seem to provide a degree of protection against ACS. In order to better predict ACS, the ROC curve analysis was employed, which determined threshold values for LDH and WBC. The established cut-off points were set at 266.26 U/L for LDH and 11.7 × 109 cells per liter for WBC, respectively. Our research has successfully pinpointed gender, crush injuries, LDH levels, and white blood cell (WBC) count as crucial risk factors for the development of ACS in patients experiencing tibial diaphysis fractures. Furthermore, by establishing the cut-off values for LDH and WBC, we have facilitated a more personalized assessment of ACS risk, enabling clinical doctors to implement targeted early interventions and optimize patient outcomes.

The effect of time from injury to fasciotomy in patients with acute upper extremity compartment syndrome.

BACKGROUND: Acute compartment syndrome of the upper extremity is a surgical emergency, and timely diagnosis with immediate fasciotomies is essential for the preservation of function. This retrospective study aimed to compare the complication rates of patients who underwent fasciotomy before and after 6 hours following the initial trauma. METHODS: The medical records of the patients who underwent fasciotomy for surgical treatment of ACS of the upper extremity between 2016 and 2022 were retrospectively analyzed for age, gender, dominant hand, mechanism of injury, injury level, affected compartments, associated injuries, time elapsed till fasciotomy, and complications. The patients were divided into two groups according to the timing of fasciotomy. RESULTS: A total of 32 patients underwent fasciotomies for upper extremity ACS. The mean age of patients who underwent fasciotomy ≤ 6 hours (group 1; 10 males, 7 females) and patients who underwent fasciotomy > 6 hours (group 2; 13 males, 2 females) was 31.1 and 34.8, respectively. The most common etiology was crushing injury. There was a significant difference in complication rates between group 1 (1/17) and group 2 (10/15) (p<0.001). The length of hospitalization stay in group 2 was statistically higher than in group 1 (p=0.005). CONCLUSION: Fasciotomies for ACS of the upper extremity should be performed in less than 6 hours following the initial trauma to prevent complications.

Exogenous Peptide Injection Causing Medical Thigh Compartment Syndrome.

BACKGROUND: Acute compartment syndrome can be caused by any condition that increases the pressure of an intracompartmental muscular space, resulting in ischemia, which is a limb-threatening emergency. This case report is the first known documented example of an exogenously injected peptide causing compartment syndrome. The use of natural supplements and holistic therapies is on the rise, specifically, peptide injections. It is important to obtain the history of use and routes of administration of these substances. CASE REPORT: We present a case of a 43-year-old man who presented to the Emergency Department with worsening thigh pain. The patient had injected a "peptide cocktail" into his thigh 3 days prior. Physical examination revealed trace pitting edema of the left leg with moderate muscle spasm and tenderness of the medial aspect of the distal thigh with associated numbness along the medial aspect of the knee. Point-of-care ultrasound detected intramuscular edema and free fluid in the leg. He was found to have acute compartment syndrome of the thigh secondary to the peptide cocktail injection, causing a large hematoma posterior to the adductor magnus. The patient required fasciotomy and hematoma evacuation. He ultimately left against medical advice during his hospitalization. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: In an age when many patients look for supplements to aid with weight loss and muscle growth, it is essential to be aware of peptide injection therapies and the potential complication of compartment syndrome.

Open versus endovascular repair of penetrating non-aortic arterial injuries: A systematic review and meta analysis.

BACKGROUND: Non-aortic arterial injuries are common and are associated with high morbidity and mortality. Historically, open surgical repair (OSR) was the conventional method of repair. With recent advancements in minimally invasive techniques, endovascular repair (ER) has gained popularity. We sought to compare outcomes in patients undergoing endovascular and open repairs of traumatic non-aortic penetrating arterial injuries. METHODS: A systematic review and meta-analysis was conducted using MEDLINE (OVID), Web of Science, Cochrane Library, and Scopus Database from January 1st, 1990, to March 20th, 2023. Titles and abstracts were screened, followed by full text review. Articles assessing clinically important outcomes between OSR and ER in penetrating arterial injuries were included. Exclusion criteria included blunt injuries, aortic injuries, pediatric populations, review articles, and non-English articles. Odds ratios (OR) and Cohen's d ratios were used to quantify differences in morbidity and mortality. RESULTS: A total of 3770 articles were identified, of which 8 met inclusion criteria and were included in the review. The articles comprised a total of 8369 patients of whom 90 % were male with a median age of 28 years. 85 % of patients were treated with OSR while 15 % underwent ER. With regards to injury characteristics, those who underwent ER were less likely to present with concurrent venous injuries (OR: 0.41; 95 %CI: 0.18, 0.94; p = 0.03). Regarding hospital outcomes, patients who underwent ER had a lower likelihood of in-hospital or 30-day mortality (OR: 0.72; 95 %CI: 0.55, 0.95; p = 0.02) and compartment syndrome (OR: 0.29, 95 %CI: 0.12, 0.71; p = 0.007). The overall risk of bias was moderate. CONCLUSION: Endovascular repair of non-aortic penetrating arterial injuries is increasingly common, however open repair remains the most common approach. Compared to ER, OSR was associated with higher odds of compartment syndrome and mortality. Further prospective research is warranted to determine the patient populations and injury patterns that most significantly benefit from an endovascular approach. LEVEL OF EVIDENCE: Level III, Systematic Reviews & Meta-Analyses.

Acute compartment syndrome of the thigh after total knee arthroplasty: a case report.

INTRODUCTION: Acute compartment syndrome of the thigh after total knee arthroplasty is a rarely described complication. After the assessment of the diagnosis, immediate surgical intervention is necessary to prevent further tissue damage. Since only a few cases have been described and because of the high complication rate, early detection is essential for ensuring patient outcomes. CASE PRESENTATION: After total knee arthroplasty in a high-volume university hospital, a 57-year-old Caucasian female patient experienced strong, disproportional pain in the ventromedial thigh of the affected leg, which did not respond to an adequate adjustment in pain medication. Imaging revealed a distinct swelling of the vastus intermedius muscle. This resulted in acute compartment syndrome of the thigh, which was immediately surgically treated. Apart from receiving surgery distal from the affected compartment and continuous intake of acetylsalicylic acid, the patient had no risk factors for developing compartment syndrome. The patient's recovery was uneventful, with timely wound closure and discharge to outpatient care without significant functional limitations. CONCLUSION: Acute compartment syndrome of the thigh represents a rare, but severe complication that can occur after orthopedic surgery. In our case, no triggering factors for the development of acute compartment syndrome, such as the use of a tourniquet, were detected. Even in unusual locations, compartment syndrome should be considered as a differential diagnosis. With sufficient evidence, immediate fasciotomy should be indicated.

Thigh compartment syndrome: Outcomes in an urban level 1 trauma center.

INTRODUCTION: Thigh compartment syndrome (TCS) is a rare surgical emergency associated with a high risk of morbidity with mortality rates as high as 47 %. There is sparse literature discussing the management as well as outcomes of these injuries. The purpose of this study is to review a consecutive series of patients presenting to a single urban Level 1 trauma center with TCS to identify injury characteristics, clinical presentation, and outcomes associated with this injury. METHODS: A trauma database was queried for all patients with a diagnosis of TCS at a single level 1 urban trauma center between January 1, 2011 and December 31, 2021. Demographic and injury variables collected included age, sex, BMI, mechanism of injury, and creatine phosphokinase levels (CPK). Hospital quality measures including time from admission to surgery, length of both hospital and ICU stay, complications, and cost of care were collected. Descriptive statistics are reported as median [interquartile range] or N (percent). RESULTS: There were 14 patients identified with a diagnosis of TCS. All were men with an average age 33.5 [23.5 - 38] years and an average BMI of 26 [22.9-28.1]. The most common cause of injury was blunt trauma (71.4 %), and the remaining 28.6 % were gunshot wound injuries. Within the cohort, 6 (42.9 %) patients sustained a femoral shaft fracture, and 4 (28.6 %) patients sustained a vascular injury. The median initial CPK of patients within this cohort was 3405 [1232-5339] and reached a peak of 5271 [3013-13,266]. The median time from admission to diagnosis was 6.8 [0-236.9] hours. The median time from admission to the operating room was 8.2 [0.6-236.9] hours, and the median number of operating room visits was 3 [2 - 6]. Five patients (35.7 %) wounds were closed with split thickness skin grafting. There were 12 (85.7 %) patients who required ICU care. The median ICU length of stay was 7.5 days [4-15]. The median hospital length of stay was 16.5 days [13.25-38.0]. The median total charges for a patient with thigh compartment syndrome was $129,159.00 [$24,768.00 - $587,152.00]. The median direct variable cost for these patients was $86,106.00 For comparison, the median direct variable cost for patients with femur fractures without TCS at this institution was $8,497.28 [$1,903.52-$21,893.13]. No patients required readmission within 60 days. There were no mortalities. CONCLUSION: TCS is a rare and life-threatening injury associated with significant morbidity. Despite rapid diagnosis and fasciotomy, the majority of the patients have prolonged hospital courses, ICU lengths of stay, and significant costs of treatment. Providers can reference the outcomes reported in this study when caring for TCS patients.

Acute compartment syndrome of the lower limbs: Fasciotomy or dermofasciotomy? A cadaver study of compartment pressures.

BACKGROUND: Acute compartment syndrome (ACS) of the lower limbs is a function-threatening event usually managed by extended dermofasciotomy. Closure of the skin may be delayed, creating a risk of complications when there is an underlying fracture. Early treatment at the pre-ACS stage might allow isolated fasciotomy with no skin incision. The primary objective of this study was to compare intracompartmental pressure (ICP) changes after fasciotomy and after dermofasciotomy. The secondary objectives were to evaluate potential associations linking the starting ICP to achievement of an ICP below the physiological cut-off of 10mm Hg and to determine whether the ICP changes after fasciotomy and dermofasciotomy varied across muscle compartments. HYPOTHESIS: Fasciotomy with no skin incision may not provide a sufficient ICP decrease, depending on the initial ICP value. MATERIAL AND METHODS: A previously validated model of cadaver ACS of the lower limbs was used. Saline was injected gradually to raise the ICP to>15mmHg (ICP15), >30mmHg (ICP30), and >50mmHg (ICP50). We studied 70 leg compartments (anterior, lateral, and superficial posterior) in 13 cadavers (mean age, 89.1±4.6years). ICP was monitored continuously. Percutaneous, minimally invasive fasciotomy consisting in one to three 1-cm incisions was performed in each compartment. ICP was measured before and after fasciotomy then after subsequent skin incision. The objective was to decrease the ICP below 10mmHg after fasciotomy or dermofasciotomy. RESULTS: Overall, mean ICP was 37.8±19.1mmHg after the injection of 184.0±133.01mL of saline. In the ICP15 group, the mean ICP of 16.1mmHg fell to 1.4mmHg after fasciotomy (ΔF=14.7) and 0.3mmHg after dermofasciotomy (ΔDF=1.1). Corresponding values in the ICP30 group were 33.9mmHg, 4.7mmHg (ΔF=29.2), and 1.2mmHg (ΔDF=3.5); and in the ICP50 group, 63.7mmHg, 17.0mmHg (ΔF=46.7), and 1.2mmHg (ΔDF=15.8). Thus, in the group with initial pressures >50mmHg, the ICP decrease was greater after both procedures, but fasciotomy alone nonetheless failed to achieve physiological values (<10mmHg). The pressure changes were not significantly associated with the compartment involved (anterior, lateral, or superficial posterior) (p<0.05). CONCLUSION: Under the conditions of this study, higher baseline ICPs were associated with larger ICP drops after fasciotomy and dermofasciotomy. Nevertheless, when the baseline ICP exceeded 50mmHg, fasciotomy alone failed to decrease the ICP below 10mmHg. Adding a skin incision achieved this goal. LEVEL OF EVIDENCE: IV, experimental study.

First Case of Surgically Treated Chronic Exertional Compartment Syndrome of the Arm.

This paper reports the first case of chronic exertional compartment syndrome in the arm treated surgically. The diagnosis was made in a patient who is under 30 years old, military, and very athletic, with recurrent exertional pain in the anterior compartment of the arms associated with rhabdomyolysis. The high-pressure measurements in the arms' anterior compartment after exertional exercise confirmed the diagnosis. Given the patient's functional demands, a surgical treatment of fasciotomy of the anterior compartment by miniapproach was performed and allowed the resolution of symptomatology with a return to sport at the same level after 3 months.

Congenital brachial artery occlusion causing neonatal forearm compartment syndrome.

Congenital brachial artery occlusion is rare. We report four patients who presented at birth with absent wrist pulses. We propose management recommendations that include anti-coagulation, duplex ultrasound assessment and fasciotomy surgery as early as is safe and possible.

Gluteal compartment syndrome: who is most at risk?

PURPOSE: Gluteal compartment syndrome (GCS) is a rare but devastating condition with a paucity of literature to help guide diagnosis and management. This study aims to identify and describe the risk factors and patient characteristics associated with GCS to facilitate early diagnosis. METHODS: This is a retrospective case series of patients undergoing gluteal compartment release between 2015 and 2022 at an academic Level I trauma center. Chart reviews were performed to extract data on patient demographics, presenting symptoms, risk factors, operative findings, and postoperative outcomes. RESULTS: 14 cases of GCS were identified. 12 (85.7%) were male, with a mean age of 39.4 ± 13 years and a mean BMI of 25.1 ± 4.1 kg/m2. 12 (85.7%) patients did not present as traumas and only 3 had ≥ 1 fracture. 9 patients reported drug use. Hemoglobin (Hgb) (11.7 ± 4 g/dL) was generally low (5 had Hgb < 10 g/dL). Creatine kinase (49,617 ± 60,068 units/L) was consistently elevated in all cases, and lactate (2.8 ± 1.6 mmol/L) was elevated in 9. 13 had non-viable muscle requiring debridement. Postoperatively, the mean ICU length of stay was 12 ± 23 days. 2 patients died during admission and all remaining patients required discharge to rehabilitation facilities. CONCLUSION: GCS is more likely to present in a young to middle-aged, otherwise healthy, male using drugs who is either found down or experienced an iatrogenic injury. Recognizing that GCS is different from that of the leg, in terms of etiology, may help avoid delays in diagnosis and treatment.

Acute Compartment Syndrome in Pediatric Patients on Extracorporeal Membrane Oxygenation Support.

BACKGROUND: When acute compartment syndrome (ACS) occurs in pediatric patients requiring venoarterial extracorporeal membrane oxygen (VA ECMO) support, there is little data to guide surgeons on appropriate management. The purpose of this study is to characterize the presentation, diagnosis, timeline, and outcomes of patients who developed this complication. METHODS: This is a single-center retrospective case series of children below 19 years old on VA ECMO support who subsequently developed extremity ACS between January 2016 and December 2022. Outcomes included fasciotomy findings, amputation, mortality, and documented function at the last follow-up. RESULTS: Of 343 patients on VA ECMO support, 18 (5.2%) were diagnosed with ACS a median 29 hours after starting ECMO. Initial cannulation sites included 8 femoral, 6 neck, and 4 central. Femoral artery cannulation was associated with an increased risk of ACS [odds ratio=6.0 (CI: 2.2 to 15), P <0.0001]. In the hospital, the mortality rate was 56% (10/18). Fourteen (78%) patients received fasciotomies a median of 1.2 hours after ACS diagnosis. Only 4 (29%) patients had all healthy muscles at initial fasciotomy, while 9 (64%) had poor muscular findings in at least 1 compartment. Patients with worse findings at fasciotomy had a significantly longer duration between ischemia onset and ACS diagnosis. Patients required a median of 1.5 additional procedures after fasciotomy, and only 1 (7%) developed a surgical site infection. Of the 7 surviving fasciotomy patients, 2 required amputations, 3 developed an equinus contracture, 1 developed foot drop, and 3 had no ACS-related deficits. Four patients did not receive fasciotomies: 3 were deemed too ill and later died, and 1 was diagnosed too late to benefit. The only surviving nonfasciotomy patient required bilateral amputations. CONCLUSIONS: Pediatric ECMO-associated ACS is not exclusive to patients with femoral artery cannulation. The majority of fasciotomy patients were diagnosed with ACS after muscle necrosis had already started. We were unable to definitively conclude whether fasciotomies provide better outcomes. There is a need for increased awareness and earlier recognition of this rare yet potentially devastating complication. LEVEL OF EVIDENCE: Level IV-retrospective case series.

The Pressure Is on: Dorsal Versus Volar Univalves for Long-arm Casts.

BACKGROUND: Fiberglass casts are routinely used to treat fractures of the upper extremity. When posttraumatic edema is anticipated, the cast is often valved to hopefully prevent potential complications, especially compartment syndrome. Due to volar forearm compartments being most involved with upper extremity compartment syndrome, volar skin surface pressures (SSP) are paramount. Despite past literature showing that a univalved cast will retain a 3-point mold better than a bivalved cast, there is a paucity of information analyzing the effects of univalving on the volar SSP. We hypothesized that a volar univalve technique would have a greater decrease in the volar skin surface pressures compared to a dorsal univalve in long-arm casts. METHODS: A 100-mL saline bag attached to an arterial line pressure transducer was placed between a long-arm cast and the skin along the volar forearm of a single adult volunteer. Fourteen casts were applied by a single certified orthopaedic technologist with 30 years of experience and assigned randomly to receive either a volar or dorsal univalve. We calculated the change in volar forearm SSP on each cast in 4 stages: isolated univalve, with a 3-mm cast spacer, with a 6-mm spacer, and with bivalve. Statistical analysis of the data was performed using a Mann-Whitney U test. RESULTS: When comparing volar versus dorsal univalve, volar SSP significantly dropped by a mean of 32.00 versus 20.43 mm Hg ( P value=0.001) in stage I, 45.14 versus 38.00 mm Hg in stage II ( P value=0.026), and 56.53 versus 49 mm Hg in stage III ( P value=0.001). There was no significant difference between the 2 groups after a bivalve was performed at stage IV ( P value=0.318). CONCLUSION: Our findings support that a volar univalve with a 6-mm spacer will provide the greatest reduction of skin surface pressure while theoretically maintaining the cast's structural integrity and biomechanical properties when compared to a bivalved cast. LEVEL OF EVIDENCE: Level II, prospective comparative study.