Well-leg compartment syndrome
Authors: Bruce Heppenstall, Virak Tan
Journal: The Lancet (1999)

Compartment syndrome is a well-known concept in the medical profession. A lesser known version is that which develops not from injury but from "abnormal" positioning of the limb. Since the calf compartments are the most commonly affected, the term well-leg compartment syndrome (WLCS) has been used to describe this syndrome. WLCS is almost exclusively associated with the lithotomy or hemilithotomy position during surgery.1Mulhall JP Drezner AD Postoperative compartment syndrome and the lithotomy position: a report of three cases and analysis of potential risk factors.Conn Med. 1993; 57: 129-133PubMed Google Scholar, 2Moses T Kreder K Thrasher J Compartment syndrome: an unusual complication of the lithotomy position.Urology. 1994; 43: 746-747Summary Full Text PDF PubMed Scopus (42) Google Scholar, 3Slater RR Jr Weiner TM Koruda MJ Bilateral leg compartment syndrome complicating prolonged lithotomy position.Orthopedics. 1994; 17: 954-959PubMed Google Scholar, 4Adler L Heppenstall RB Esterhai JL Compartment syndrome in the well leg: a complication of the hemilithotomy position.Tech Orthop. 1997; 12: 133-135Crossref Scopus (8) Google Scholar The hemilithotomy position-unilateral elevation of the uninjured leg above the plane of the body with the hip abducted and flexed and the knee flexed-is commonly used in orthopaedic surgery to provide unobstructed access to the injured leg for fluoroscopic imaging. WLCS is not limited to orthopaedic surgery. It may be more common in urology, general surgery, and obstetrics and gynaecology, the common denominator being the maintenance of the lithotomy position for a long time. Since 1979, only 26 cases of WLCS have been reported.1Mulhall JP Drezner AD Postoperative compartment syndrome and the lithotomy position: a report of three cases and analysis of potential risk factors.Conn Med. 1993; 57: 129-133PubMed Google Scholar, 2Moses T Kreder K Thrasher J Compartment syndrome: an unusual complication of the lithotomy position.Urology. 1994; 43: 746-747Summary Full Text PDF PubMed Scopus (42) Google Scholar, 3Slater RR Jr Weiner TM Koruda MJ Bilateral leg compartment syndrome complicating prolonged lithotomy position.Orthopedics. 1994; 17: 954-959PubMed Google Scholar, 4Adler L Heppenstall RB Esterhai JL Compartment syndrome in the well leg: a complication of the hemilithotomy position.Tech Orthop. 1997; 12: 133-135Crossref Scopus (8) Google Scholar However, preliminary data from the Mayo Clinic suggest a frequency of one in 3500 for patients undergoing surgery in the lithotomy position.5Halliwill J Hewitt S Joyner M Warner M Effect of various lithotomy positions on lower-extremity blood pressure.Anesthesiology. 1998; 89: 1373-1376Crossref PubMed Scopus (93) Google Scholar The clinical picture of WLCS is the same as for any limb-compartment syndrome. Because the complication is unexpected and the patient is anaesthetised, the diagnosis is delayed in many cases, so the residual motorsensory deficit may be severe, even after fasciotomy. Although time is the main factor associated with the development of this complication, there has only been anecdotal evidence to support this theory. WLCS was initially thought to occur only with procedures lasting longer than 6·5 h,3Slater RR Jr Weiner TM Koruda MJ Bilateral leg compartment syndrome complicating prolonged lithotomy position.Orthopedics. 1994; 17: 954-959PubMed Google Scholar but has since been known to occur after 2–3 h.6Tan V. Well-leg compartment pressures during hemilithotomy position for fracture fixation. Orthopaedic Trauma Association 14th Annual Meeting, Vancouver, Canada, 1998.Google Scholar The cause of WLCS has not been well established. The two main theories are direct external compression and vascular insuffiency or hypoperfusion of the calf muscles, or a combination of the two. The common pathway may be hypo-oxygenation, leading to local ischaemia, tissue oedema, and fulminant compartment syndrome. Support for direct compression lies in the finding that, when the uninjured leg is placed in the well-leg holder in the hemilithotomy position, the calf-compartment pressures increase by more than 18 mm Hg.7Tan V, Glaser D, Seldes R, Pepe M, Heppenstall R, Esterhai JL. Well-leg compartment pressures during hemilithotomy position for fracture fixation. J Orthopaedic Trauma (in press).Google Scholar No other physiological process could account for such a striking and rapid increase. The high correlation between body-mass index and calf pressures further strengthens this argument. This mechanism also accounts for the clinical observation that heavy limbs are predisposed to the development of WLCS.4Adler L Heppenstall RB Esterhai JL Compartment syndrome in the well leg: a complication of the hemilithotomy position.Tech Orthop. 1997; 12: 133-135Crossref Scopus (8) Google Scholar Several studies support the vascular insufficiency/ hypoperfusion theory, which may entail several components. First, elevation of the leg alone will lower the mean arterial pressure (ie, pressure head for perfusion) in the leg because of hydrostatic pressure.8Matsen 3rd., FA A practical approach to compartment syndromes. American Academy of Orthopaedic Surgeons, Park Ridge, IL1983: 88-91Google Scholar In addition, further reductions in the leg systolic pressures, beyond that seen with elevation, occur with varying positions of lithotomy.5Halliwill J Hewitt S Joyner M Warner M Effect of various lithotomy positions on lower-extremity blood pressure.Anesthesiology. 1998; 89: 1373-1376Crossref PubMed Scopus (93) Google Scholar Finally, venous stasis, which may occur during lithotomy increases the intramuscular pressure of the calf.9Wiger P Styf JR Effects of limb elevation on abnormally increased intramuscular pressure, blood perfusion pressure, and foot sensation: an experimental study in humans.J Orthop Trauma. 1998; 12: 343-347Crossref PubMed Scopus (29) Google Scholar All these factors can cause hypoperfusion of the leg, which may contribute to the development of WLCS. Clearly, prevention is the key to the management of this complication. When there is bony or soft-tissue injury to the "well leg" or when the patient is very obese, the lithotomy position should be avoided. Time spent in the lithotomy position should also be kept to a minimum. For most orthopaedic procedures, the leg does not need to be in that position during the entire operation. An alternative position for fracture fixation on the fracture table is to abduct and extend the well leg. This position can be used for most patients, depending on body habitus and hip-joint motion. Furthermore, retrograde nailing enables open reduction and internal of fixation of the femur to be done with the leg supine on an image operating table. Approaches to minimise or avoid the time spent in the lithotomy position may not be as applicable to the other surgical specialties. However, during long procedures, the leg should be taken down from the lithotomy position regularly. In addition, close surveillance and a high index of suspicion are needed. Continuous monitoring of the compartment pressures should be considered for these cases.