John F. Connolly, MD

Patients with ankylosing spondylitis areat increased risk for fractures (particularlyextension fractures of the cervicaland thoracolumbar spine) and spinalcord injury. Fractures in these patientsare extremely unstable; in fact, they areamong the most complication-prone ofall cervical spine injuries likely to beseen in the primary care setting.

Plaster of Paris itself can be hazardous because of the thermal reactions thatoccur as the material sets. When water is added to plaster of Paris powder, thewater molecules go from a liquid to a solid state by incorporating into the crystallattice of the calcium sulfate hemihydrate. This converts kinetic energy intoheat. If hot water is applied to plaster of Paris to begin this kinetic process, theheat given off from the resulting crystallization can actually burn the patient'slimb.

Occasionally, protective splinting with plaster of Paris splints can create problems, particularly in patients with diabetes and loss of protective sensation who are readily susceptible to pressure sores.

These temporary splints are associatedwith special complications relatedto both the action or condition ofthe patient and the nature of thesplint itself. At our orthopaedic clinic,we commonly see patients whohave been referred from the emergencydepartment in a temporarysplint after a minor ankle sprain or afracture of the lateral malleolus. Ifthe patient allows the foot to hang ina nonfunctional position withoutweight bearing, the injured anklemay swell like a sausage.

Infection of the “simple” open fractureof the distal radius is a significant-but fortunately rare-complication ofimmobilizing musculoskeletal injuriesof the upper extremity. Cliniciansoften underestimate the extent towhich this type of fracture can be contaminated,particularly if the patientpresents with a small puncture wounddirectly over the fractured distal radiusthat conceals the degree of contaminationat the fracture site. If openfractures of the distal radius are simplywashed out in the emergency department and temporarily splinted, overwhelming sepsis fromclostridial myonecrosis may develop, leading to amputation.

The goal in managing manymusculoskeletal injuries isnow early mobilization-notimmobilization. This shift inemphasis encompasses injuriesranging from a strained backto a sprained ankle. Patients withsciatica who previously might havebeen kept at bed rest for severalweeks are now encouraged to avoidbed rest and to alleviate nerve irrita-tion with positional exercises. Similarly,patients with ankle sprainsgain faster pain relief and recoverfunction more rapidly when cast orsplint immobilization is avoided.Early mobilization is appropriate formany acute injuries without riskof significant bone or joint instability.Its advantages have emerged asthe many detriments or hazards ofeven brief periods of immobilizingmuscles, joints, and bones havebecome apparent.

Ulnar nerve problems can occurwhen the elbow is immobilized in flexionbeyond a right angle (ie, less than90 degrees). This can compress theulnar nerve as it travels through thecubital tunnel, a problem especiallylikely if the ulnar nerve is relativelymobile and moves up against the epicondyle,as it did in this patient whohad sustained a radial fracture. Ulnarneuropathy developed after a longarmcast was applied with the elbowhyperflexed.