Andrew H. Schmidt

A prospective, randomized study of intramedullary nails inserted with and without reaming for the treatment of open and closed fractures of the tibial shaft.

OBJECTIVES To determine if there are differences in healing, complications, or number of procedures required to obtain union among open and closed tibia fractures treated with intramedullary (IM) nails inserted with and without reaming. DESIGN Prospective, surgeon-randomized comparative study. SETTING Level One trauma center. PATIENTS Ninety-four consecutive patients with unstable closed and open (excluding Gustilo Grade IIIB and IIIC) fractures of the tibial shaft treated with IM nail insertion between November 1, 1994, and June 30, 1997. INTERVENTION Interlocked IM nail insertion with and without medullary canal reaming. MAIN OUTCOME MEASURES Time to union, type and incidence of complications, and number of secondary procedures performed to obtain union. RESULTS For open fractures, there were no significant differences in the time to union or number of additional procedures performed to obtain union in patients with reamed nail insertion compared with those without reamed insertion. A higher percentage of closed fractures were healed at four months after reamed nail insertion compared with unreamed insertion (p = 0.040), but there was not a difference at six and twelve months. More secondary procedures were needed to obtain union after unreamed nail insertion for the treatment of closed tibia fractures, but the difference was not statistically significant given the limited power of our study (p = 0.155). Broken screws were seen only in patients treated with smaller-diameter nails inserted without reaming, and the majority occurred in patients who were noncompliant with weight-bearing restrictions. There were no differences in rates of infection or compartment syndrome. CONCLUSION Our findings support the use of reamed insertion of IM nails for the treatment of closed tibia fractures, which led to earlier time to union without increased complications. In addition, canal reaming did not increase the risk of complications in open tibia fractures.

Fractures of the proximal part of the femur.

The orthopaedic surgeon has a multitude of internal fixation devices and techniques available for use in the treatment of subtrochanteric fractures of the proximal femur. The successful use of second-generation locking nails is technically demanding. Close attention to positioning of the patient, reduction of the fracture, placement of the guide-wire, and insertion of the nail and of the proximal and distal locking screws is mandatory. The newer, high-strength hip-screws allow good fixation of a fracture that extends into the piriformis fossa. If medial comminution is present, this technique is best performed in conjunction with indirect reduction and bone-grafting. With proper technique, these devices allow the surgeon to manage predictably a complex subtrochanteric fracture that previously had to be treated with traction or extensive dissection and with (frequently inadequate) internal fixation.

Periprosthetic Fractures of the Femur

Periprosthetic fractures of the femur represent a heterogeneous and challenging problem for the orthopedic surgeon. The incidence of these fractures is dramatically increasing, as there are more and more patients with aging total joint replacements. The fractures may occur as the result of a traumatic event, but more often are the result of minor trauma spontaneous fracture, and they are frequently associated with preexisting, sometimes neglected, problems with the associated joint replacement.

Proximity of iliosacral screws to neurovascular structures after internal fixation

The placement of iliosacral screws for the stabilization of pelvic ring lesions is technically demanding. The postoperative computed tomography scans of 31 patients who had 57 iliosacral screws placed for various indications were studied to determine the proximity of these screws to neurovascular structures. The closest distance of the screws from the S1 foramen averaged 3 mm. (range, 0-10.5 mm); the average closest distance to the anterior cortex of the sacral ala was 4.8 mm (range, 0-15.3 mm). The corridor for the insertion of the screws between the S1 foramen and the anterior cortex of the sacrum averaged 21.7 mm (range, 16.2-28.9 mm). Trigonometric analysis of these dimensions suggests that deviations of the surgeons hand by as little as 4 degrees may direct iliosacral screws either into the S1 foramina or through the anterior cortex of the sacrum.

Femoral neck fractures.

Despite the tremendous advances in the science and practice of orthopaedic surgery, anesthesia, and perioperative care, repair of displaced fractures of the neck of the femur is still associated with complications in up to one third of patients. The risk of nonunion and osteonecrosis in particular is virtually the same today as in the 1930s. Recent data from well-designed outcome studies now indicate that the most predictable, durable, and cost-effective procedure for an active elderly patient with a displaced femoral neck fracture is total joint arthroplasty; however, not all patients are candidates for this procedure, and the potential complications of arthroplasty, including mortality, may be more difficult to manage and more severe than those associated with internal fixation. The laudable goal of obtaining fracture healing and maintenance of a viable femoral head can be successfully achieved in a number of patients.

Intramedullary nailing following external fixation in femoral and tibial shaft fractures.

Background: Intramedullary nailing is the standard of care for the definitive management of lower extremity long bone fractures. Occasionally, temporary external fixation is used in fractures with severe open wounds or vascular injury before definitive intramedullary nailing. Secondary intramedullary nailing following external fixation is somewhat controversial, especially with respect to the duration of external fixation that is allowable before the risk of infection following later nailing becomes too great. Several recent studies have provided further insight into this issue. Objective: The primary objective is to evaluate infection and nonunion rates in patients treated with temporary external fixation and secondary intramedullary nailing for lower extremity long bone fractures. The secondary objective is to evaluate whether the duration of external fixation and the interval time (defined as the time from external fixator removal to intramedullary nailing) influence the risk of infection after intramedullary nailing.

Treatment of Closed Tibial Fractures

Closed tibial shaft fractures are common injuries that remain challenging to treat because of the wide spectrum of fracture patterns and soft-tissue injuries. Understanding the indications for surgical and nonsurgical treatment of these fractures is essential for good outcomes. Although cast treatment of stable tibial shaft fractures has traditionally been successful and continues to be widely used, recent clinical studies have shown that intramedullary nails may be more advantageous for fracture healing and function than casting. Surgical treatment (intramedullary nailing, plate fixation, or external fixation) of closed tibial shaft fractures varies depending on multiple factors. Metaphyseal fractures are well suited for plates, although newer intramedullary nail designs provide the option of intramedullary nailing of proximal or distal metaphyseal tibia-fibula fractures. External fixators are well suited for skeletally immature patients with unstable fracture patterns or for patients with unacceptably small intramedullary canals. Interlocking intramedullary nails are the treatment of choice for most unstable tibia-fibula shaft fractures.

Pathophysiology of Infections After Internal Fixation of Fractures

&NA; Infection complicating internal fixation of fractures is a serious complication that is difficult to treat. Whenever metallic devices are implanted in vivo, successful biointegration requires that host cells colonize the highly reactive implant surface. Bacteria such as staphylococci can also become adherent to metallic or polymeric implants and will compete with host cells for colonization of the implant surface. Once adherent, these bacteria form a biofilm and undergo phenotypic changes that make them resistant to the normal host immune response as well as to antibiotics. Furthermore, metallic implants themselves cause specific deficits in the function of the local immune system that may render the host response to infection inadequate. Any associated soft‐tissue injury causes even greater impairment of local immune function. Despite the potentially detrimental impact of internal fixation, fracture stability is of paramount importance in achieving fracture union and in preventing infection. It has been demonstrated in animal models that contaminated fractures without internal fixation develop clinical infection more commonly than similar fractures treated with internal fixation at the time of colonization. Because of the potential for infection whenever internal fixation is utilized, appropriate prophylactic antibiotic coverage for staphylococci and Gram‐negative organisms should be provided. Open wounds and severely damaged soft tissues require aggressive management so that a viable soft‐tissue envelope is maintained around the implant. Host factors such as smoking and malnourishment should be corrected. Early diagnosis and aggressive treatment of implant‐related infection with antibiotics, debridement, and maintenance of stable internal fixation are essential to successful treatment.

Periprosthetic knee fractures.

Fractures of the distal femur, proximal tibia, and patella that occur adjacent to a total knee replacement may be very difficult to treat. Fixation options are compromised because of the short articular segment, frequent comminution, pre-existing osteoporosis, previous surgical incisions, and the presence of the knee implant itself. This review article summarizes current concepts regarding the incidence, classification, treatment options, and outcomes for periprosthetic fractures of the knee.

Recombinant Human Osteogenic Protein-1 Induces Bone Formation in a Chronically Infected, Internally Stabilized Segmental Defect in the Rat Femur

BACKGROUND Recombinant human osteogenic protein-1 (rhOP-1), combined with a collagen carrier, has been shown to induce new-bone formation in a variety of animal models. The purpose of the present investigation was to test the hypotheses that rhOP-1 would accelerate bone formation in an internally stabilized, chronically infected, critical-size defect in the rat femur and that this effect would be enhanced by the administration of systemic antibiotic. METHODS A 6-mm segmental defect was created surgically, stabilized with a polyacetyl plate and six Kirschner wires, and contaminated with 10(4) colony-forming units of Staphylococcus aureus in one femur in each of 168 Sprague-Dawley rats. After two weeks, these infected defects were débrided surgically and were assigned to one of six treatment groups. The defects in the thirty animals in the first group received lyophilized collagen carrier mixed with 200 microg of rhOP-1 dissolved in buffer, the defects in the thirty animals in the second group received carrier with 20 microg of rhOP-1 in buffer, and the defects in the twenty-four control animals in the third group received carrier mixed with buffer without rhOP-1. The last three groups were treated identically to the first three groups, except that the animals also received the antibiotic ceftriaxone for twenty-eight days after débridement. The animals were killed at two, four, eight, or twelve weeks after débridement. Newly mineralized callus within the defect, and adjacent to and bridging the outside of the defect, was assessed with use of quantitative high-resolution radiography, microcomputed tomography, torsional failure testing, and histological analysis of undecalcified sections. RESULTS Bacterial cultures confirmed the presence of a chronic infection during the study period in all animals. At the later time-points, significantly more newly mineralized callus was present within and adjacent to the débrided defects that had been treated with 200 microg of rhOP-1, whereas minimal amounts of callus were present within and adjacent to the defects that had been treated without rhOP-1 and with 20 microg of rhOP-1. At eight and twelve weeks after débridement, there was significantly more newly mineralized callus in the group that had been treated with 200 microg of rhOP-1 with antibiotic than in the group that had been treated with 200 microg of rhOP-1 without antibiotic (p < 0.05). At twelve weeks, the values for torque, energy to failure, and linear stiffness for femora that had been treated with 200 microg of rhOP-1 with antibiotic were not significantly different from the values for intact, contralateral control femora, whereas the values for femora that had been treated with 200 microg of rhOP-1 without antibiotic remained significantly lower than those for the intact, contralateral controls (p < 0.05). CONCLUSIONS Recombinant human osteogenic protein-1 maintained its osteoinductive capability in the presence of chronic infection, and this property was enhanced by antibiotic therapy. No substantial callus formed in the infected defects without a sufficiently high dose of rhOP-1. CLINICAL RELEVANCE The treatment of an infection at the site of a fracture often necessitates removal of internal fixation. However, internal fixation is needed for fracture stability. This study presents an intervention that may accelerate fracture-healing in the presence of infection and colonized hardware, thereby permitting earlier removal of the hardware and more timely and effective treatment of the infection.