Session VII - Tibia

Un-reamed vs. "Reamed to Fit" Technique of Tibial Nailing in Open Fractures: Evaluation of Outcomes and Cost Analysis

Bruce H. Ziran, MD; Brian Klatt, MD; Michael Darowish, BA, University of Pittsburgh Medical Center, Pittsburgh, PA

Introduction: The treatment for Gustilo-Anderson Grades I-IIIA, most IIIB, and occasionally IIIC open fractures has evolved to the use of intramedullary fixation. Controversy remains concerning the technique of intramedullary nail insertion, whether reamed or unreamed. In the past, the term "reamed nailing" implied aggressive reaming and insertion of large-diameter nails (13-16mm), which often caused thermal damage to the bone and, in open fractures, resulted in an increased infection rate. As a result, small-caliber nails (8-9mm) were inserted without reaming in order to avoid thermal injury and to minimize the disruption to the tenuous remaining blood supply of the tibia. Recent reports have suggested a higher risk of non-union and hardware complications with such small caliber nails. The authors believe that there is little difference in the amount of disruption of the tibial blood supply between inserting an 8- or 9-mm nail without reaming versus using a reamer to allow placement of a nail that more completely fills the canal. Furthermore, the use of a larger caliber nail will increase the mechanical durability of the device and potentially decrease the need for revision surgery. This study reports our experience comparing reamed versus unreamed tibial nailing of all open fractures presenting to the authors' institution, using a prospectively designed, surgeon -controlled protocol.

Methods: All open tibia fractures over a 4-year period treated with one of two treatment protocols espoused by senior surgeons at the authors' institution were evaluated. Each protocol employed aggressive debridement techniques with early microvascular coverage when indicated. The protocols differed in that one group of surgeons always placed unreamed tibial nails, while the other group used a minimally reamed technique, using the reamer as a canal sound. In both groups, patients remained non-weight bearing until healed and were evaluated at routine intervals. The need for bone graft or other secondary intervention was determined based on established guidelines in the literature and the judgment of the surgeon. All trauma cases were reviewed weekly by faculty to monitor consistency of each surgeon's decision making. Another difference between the two protocols is that the group that utilized the minimally reamed technique also used antibiotic impregnated poly methyl methacrylate beads (ATB) for grade IIIB open fractures. In addition to evaluating demographic and peri-operative data, clinical and radiographic healing, complications, the occurrence of infection, hardware problems, and the need for secondary surgery related to the indexed fracture were examined. Global cost difference between the two protocols was determined, using the hospital's cost basis as an academic institution. To eliminate disposition and logistics bias, only operating room and anesthesia costs were included in the analysis. Statistical analysis was done using a Fisher's Exact test with P <0.05 considered significant.

Results: A total of 51 patients were identified. In the reamed group there were 22 patients (15 males, 7 females) with a mean age of 38 (range 17-69). In the unreamed group there were 29 patients (24 males, 5 females) with a mean age of 40 (range 15-76). There were no significant differences in demographics, mechanism of injury, severity of fracture, fracture type, or other peri-operative data. Nail sizes were 1x8mm, 4x9mm, 12x10mm, 3x11mm, and 2x12mm in the reamed group and 18x8.25, 8x9mm, 3x10mm in the unreamed group. In the 22 reamed cases there were 2/20GI, 4/20GII, 5/20 GIIIA, 11/20 GIIIB open fractures. In the 29 unreamed cases there were 3/29 GI, 7/29 GII, 3/29 GIIIA, 15/29 GIIIB, 1/29 GIIIC open fractures. Overall, 21/22 patients (95%) in the reamed group healed and 28/29 patients (96%) in the un-reamed group healed. The healing rate was reported as percent healed at each follow-up interval: 12 months (R=73%, NR=85%), 18 months (R=82%, NR=92%), 24 months (R=95%, NR=96%). It appeared that the reamed group healed slightly slower than the unreamed group, but the difference was not statistically significant. There was one amputation in each group. In general, the unreamed group required significantly more supplemental procedures than the reamed group (R=11, NR=29). In the reamed group there were 5 dynamizations, 4 bone grafting, and 2 supplemental fixations (screws/plates). In the un-reamed group, there were 12 dynamizations, 11 bone graftings, and 5 exchange nailings. Additionally, 6 patients in the unreamed group had the use of an electrical bone stimulator during the course of treatment. There were 3 screw failures (SF) in the unreamed group and 1 in the reamed group. Un-reamed nailing required a statistically significant greater number of procedures to attain healing. (P <0.05) A second intervention was required for 9/22 (41%) of the reamed group and 20/29 (69%) of the unreamed group. A third procedure was required for 8/29 (28%) of the unreamed group and only 1/22 (4%) of the reamed group. A fourth procedure was required for 2/29 (7%) of the unreamed group and none of the reamed group. One patient from the unreamed group required a fifth and sixth procedures. Infections developed in 2/22 (9%) (2 GIIIB) of the reamed group and 7/29 (25%) (1 GII, 1 GIIIA, 5GIIIB) of the non-reamed group. (P = NS) This may in part be due to the use of antibiotic beads in the reamed group, but this effect was not statistically significant. We also determined the cumulative cost for each method of nailing beyond the initial nailing procedure. When all secondary procedures were averaged for each method of nailing (cumulative procedural costs/number of fractures), we found that the average cost of using the reamed technique was approximately $4900/fracture less than with the unreamed technique ($8500 vs 3600).

Discussion: In a series of comparable groups, we found that the healing outcome of open tibial fractures using either reamed or un-reamed techniques of nailing were comparable. The reason we use a "ream to fit" technique is to allow the use of a larger nail that fills the canal. We believe that this not only increases the stability of the fracture construct but also allows use of larger inter-locking screws that are less likely to fail. Previous literature discouraged the use of large caliber nails with reaming and encouraged the used of smaller caliber nails inserted without reaming due to an increased risk of infection. This was surmised to be from thermal damage and devascularization from reaming. We did see an increase in the rate of infection with the "ream to fit" technique. We recognize that the use of beads may have biased the reamed group with regard to infection, and if not used may have resulted in an increased rate of infection. However, to equal that of unreamed nails, the rate would have had to increase by 150%. Recent studies using the same "ream to fit" technique found no difference between reamed and unreamed nailing with regard to healing and infection.

We have corroborated those findings, but additionally found that the number of secondary procedures required with the un-reamed technique is significantly greater than with a minimally reamed technique. We surmise that the reason for such problems with union may be due to the fact that small caliber nails do not fill the canal. Subsequently, this mis-match between the nail and canal size may allow more motion at the fracture site and predispose to problems with union. Using a larger nail that fills the canal may increase the mechanical durability of the construct and allow more time for biologic healing to occur. Another implication of the additional procedures required with the un-reamed technique is the increased cost of treatment. Considering that the incidence of tibial fractures is approximately 2/10,000 people, of which approximately 25% are open, the economic impact of such additional procedures in a large population can be substantial. There are further implications to the patient with regards to the psychosocial burdens and the longer term of disability. We conclude that the use of a reamer to "sound" the canal and allow placement of a larger nail does not appear to be deleterious and may actually have beneficial effects. A larger study is warranted to fully determine which method should be used.