Interlocking intramedullary nailing with and without reaming for the treatment of closed fractures of the tibial shaft. A prospective, randomized study

Computational comparison of reamed versus unreamed intramedullary tibial nails

We compared, via a computational model, the biomechanical performance of reamed versus unreamed intramedullary tibial nails to treat fractures in three different locations: proximal, mid-diaphyseal, and distal. Two finite element models were analyzed for the two nail types and the three kinds of fractures. Several biomechanical variables were determined: interfragmentary strains in the fracture site, von Mises stresses in nails and bolts, and strain distributions in the tibia and fibula. Although good mechanical stabilization was achieved in all the simulated fractures, the best results were obtained in the proximal fracture for the unreamed nail and in the mid-diaphyseal and distal fractures for the reamed nail. The interlocking bolts, in general, were subjected to higher stresses in the unreamed tibial nail than in the reamed one; thus the former stabilization technique is more likely to fail due to fatigue.

Intramedullary nailing of the lower extremity: biomechanics and biology

The intramedullary nail or rod is commonly used for long-bone fracture fixation and has become the standard treatment of most long-bone diaphyseal and selected metaphyseal fractures. To best understand use of the intramedullary nail, a general knowledge of nail biomechanics and biology is helpful. These implants are introduced into the bone remote to the fracture site and share compressive, bending, and torsional loads with the surrounding osseous structures. Intramedullary nails function as internal splints that allow for secondary fracture healing. Like other metallic fracture fixation implants, a nail is subject to fatigue and can eventually break if bone healing does not occur. Intrinsic characteristics that affect nail biomechanics include its material properties, cross-sectional shape, anterior bow, and diameter. Extrinsic factors, such as reaming of the medullary canal, fracture stability (comminution), and the use and location of locking bolts also affect fixation biomechanics. Although reaming and the insertion of intramedullary nails can have early deleterious effects on endosteal and cortical blood flow, canal reaming appears to have several positive effects on the fracture site, such as increasing extraosseous circulation, which is important for bone healing.

Intramedullary nailing of proximal quarter tibial fractures

OBJECTIVE

To report the results of intramedullary nailing of proximal quarter tibial fractures with special emphasis on techniques of reduction.

DESIGN

Retrospective clinical study.

SETTING

Level 1 trauma center.

PATIENTS

During a 36-month period, 456 patients with fractures of the tibial shaft (OTA type 42) or proximal tibial metaphysis (OTA type 41A2, 41A3, and 41C2) were treated operatively at a level 1 trauma center. Thirty-five patients with 37 fractures were treated primarily with intramedullary nailing of their proximal quarter tibial fractures and formed the study group. Thirteen fractures (35.1%) were open and 22 fractures (59.5%) had segmental comminution. Three fractures had proximal intraarticular extensions.

MAIN OUTCOME MEASUREMENTS

Alignment and reduction postoperatively and at healing. An angular malreduction was defined as greater than 5 degrees in any plane.

RESULTS

Fractures extended proximally to an average of 17% of the tibial length (range, 4% to 25%). The average distance from the proximal articular surface to the fracture was 67.8 mm (range, 17 mm to 102 mm, not corrected for distance magnification, included for preoperative planning purposes only). Postoperative angulation was satisfactory (average coronal and sagittal plane deformity of less than 1 degree) as was the final angulation. Acceptable alignment was obtained in 34 of 37 fractures (91.9%). Two patients had 5-degree coronal plane deformities (one varus and one valgus), and 1 patient had a 7-degree varus deformity. Two patients with open fractures with associated bone loss underwent a planned, staged iliac crest autograft procedure postoperatively. Four patients were lost to follow-up. In the remaining 31 patients with 33 fractures, the proximal tibial fractures united without additional procedures. No patient had any change in alignment at final radiographic evaluation. Secondary procedures to obtain union at the distal fracture in segmental injuries included dynamizations (n = 3) and exchange nailing (n = 1). Complications included deep infections in 2 patients that were successfully treated.

CONCLUSIONS

Multiple techniques were required to obtain and maintain reduction prior to nailing and included attention to the proper starting point, the use of unicortical plates, and the use of a femoral distractor applied to the tibia. Simple articular fractures and extensions were not a contraindication to intramedullary fixation. The proximal tibial fracture healed despite open manipulations. Short plate fixations to maintain this difficult reduction, either temporary or permanent, were effective.

Surgical treatment of nonarticular distal tibia fractures

Distal tibia metaphyseal fractures can be difficult to manage. Treatment selection is influenced by the proximity of the fracture to the plafond, fracture displacement, comminution, and injury to the soft-tissue envelope. Nonsurgical management is possible for stable fractures with minimal shortening. Indications for intramedullary nailing have expanded to include distal metaphyseal tibia fractures. Intramedullary nailing allows atraumatic, closed stabilization while preserving the vascularity of the fracture site and integrity of the soft-tissue envelope. Intramedullary canal anatomy at this level prevents intimate contact between the nail and endosteum, however, and concerns have been raised regarding the biomechanical stability of fixation and risk of malunion. Plate fixation is effective in stabilizing distal tibia fractures. Conventional techniques involve extensive dissection and periosteal stripping, which increase the risk of soft-tissue complications. Percutaneous plating techniques use indirect reduction methods and allow stabilization of distal tibia fractures while preserving vascularity of the soft-tissue envelope. External fixation is effective in the setting of contaminated wounds or extensive soft-tissue injury. Careful preoperative planning with consideration for fracture pattern and soft-tissue condition helps guide implant selection and minimize postoperative complications.

Does open reduction increase the chance of infection during intramedullary nailing of closed tibial shaft fractures?

OBJECTIVE

To evaluate whether an open technique used to obtain reduction during intramedullary nailing of closed tibial shaft fractures increases the risk of infection, compared to closed reduction and nailing.

SETTING

University level 1 trauma center.

DESIGN

Retrospective database analysis.

PATIENTS/PARTICIPANTS

One hundred seventeen patients with 119 fractures from our trauma database who had sufficient follow-up and met study criteria. The patients were grouped by open versus closed reduction. Only OTA fracture types 42 A to C were included in this study.

INTERVENTION

Locked reamed intramedullary nailing for closed tibial shaft fractures accomplished through either open or closed reduction.

MAIN OUTCOME MEASUREMENT

The presence or absence of infection as determined by the clinical presentation (erythema, warmth, purulent drainage, fevers, chills, increased pain at the fracture site), indicative laboratory work (complete blood count, erythrocyte sedimentation rate, C-reactive protein), and/or positive culture.

RESULTS

There were 85 males and 32 females. The average age was 35.7 years; the average follow-up was 14.3 months. Of the 119 fractures, 79 had closed reduction whereas 40 had open reduction. The open reductions consisted of 13 with a formal incision (>1 cm in length), 22 with percutaneous incisions, and 5 with fasciotomies. There were no infections in the closed reduction group and 2 infections (5%) in the open reduction group. This difference was not statistically significant (P=0.1). The average time to union was 7.0 months in closed reductions and 7.3 months in open reductions. By latest follow-up, 107 fractures had reached union (89.9%), 1 had not (0.8%), and 11 were lost to final follow-up (9.2%).

CONCLUSIONS

Limited open techniques can greatly facilitate the reduction of closed tibial shaft fractures but raise concern for infection through exposure of the fracture site. This study found that the rate of infection for open versus closed reductions was higher but not statistically different. Judicious use of open reduction techniques during intramedullary nailing of closed tibia fractures seems to have a minimal risk of infection.

Common errors in the design of orthopaedic studies

There are several issues that one has to take into consideration in order to avoid potential pitfalls in the design of orthopaedic studies. This article highlights how to avoid common errors and how to continue the drive towards the unattainable, but laudable, goal of perfection.

Factors affecting fracture healing after intramedullary nailing of the tibial diaphysis for closed and grade I open fractures

As there is little information on the factors that influence fracture union following intramedullary nailing of the tibia we retrospectively investigated patient-, injury- and treatment-related factors in 161 patients with closed or grade I open fractures of the tibial diaphysis. The patients were reviewed until clinical and radiological evidence of union at a mean of 13.3 months (4 to 60). Multivariate statistical analysis using a Cox proportional hazards model showed that the risk of failure of union increased by 2.38 times for highly comminuted fractures, by 3.14 times when nail dynamisation was applied, and by 1.65 times when the locking screws failed. In fractures with no or only minimal comminution the risk of nonunion increased if the post-reduction gap was ≥ 3 mm.

Reoperation rate in diaphyseal tibia fractures

BACKGROUND

Tibia fractures often require secondary surgery to achieve union. Reoperation is an objective outcome measure that is clinically relevant to the patients and treating doctors. This study determined the complication and reoperation rates for diaphyseal tibia fractures and identified variables predictive of reoperation.

METHODS

One-hundred and sixty-seven patients with 175 consecutive tibia shaft fractures (Association for the Study of Internal Fixation classification 42) presenting between July 2000 and June 2003 were included in the study. There were 4 deaths and 12 patients lost to follow up. The remaining 151 patients (159 fractures) were reviewed at a minimum of 6 months post-injury for the main outcome measures; union and reoperation. Univariate and multivariate analyses by logistic regression were used to identify any relationship between revision surgery and fracture classification, grade of the soft-tissue injury, mechanism of injury, age, sex, and treating surgeon.

RESULTS

The overall reoperation rate was 35.8% (57/159) with 13.2% (21/159) tibiae requiring minor revision surgery and 22.6% (36/159) tibiae requiring major revision surgery. Thirteen (8.2%) patients underwent major revision surgery specifically for non-union. The fracture classification and the Gustilo grade of soft-tissue injury were significant predictors of revision surgery overall, and of major revision surgery.

CONCLUSIONS

Tibial shaft fractures have a high revision rate as a consequence of non-union and infection. Revision surgery is best predicted by the fracture classification and the severity of the soft-tissue injury. This information is important for patient information and clinical decision making.

Chronic posttraumatic osteomyelitis and infected nonunion of the tibia: current management concepts

Chronic posttraumatic osteomyelitis and infected nonunion of the tibia are complex problems that result in considerable morbidity and can threaten viability of the limb. Development of infection may result from compromised soft tissue and bone vascularity, systemic compromise of the host, and virulent or resistant organisms. Biofilm formation on implant and devascularized bone surfaces protects pathogens and may lead to persistence of infection. Management is based on a detailed evaluation of the patient, the involved bone and soft tissues, degree of associated lower extremity injury, and type of bacterial pathogens. Infection control is achieved with radical débridement, skeletal stabilization, and microbial-specific antibiotics. Local antibiotic delivery is a useful supplement to systemic administration. Local or free muscle flaps may be necessary to achieve soft-tissue coverage. Restoration of bone defects and bony union can be accomplished with bone grafting. However, large defects require complex reconstructive procedures, such as distraction osteogenesis and vascularized bone grafting.

An economic analysis of management strategies for closed and open grade I tibial shaft fractures

BACKGROUND

Closed and open grade I (low-energy) tibial shaft fractures are a common and costly event, and the optimal management for such injuries remains uncertain.

METHODS

We explored costs associated with treatment of low-energy tibial fractures with either casting, casting with therapeutic ultrasound, or intramedullary nailing (with and without reaming) by use of a decision tree.

RESULTS

From a governmental perspective, the mean associated costs were USD 3,400 for operative management by reamed intramedullary nailing, USD 5,000 for operative management by non-reamed intramedullary nailing, USD 5,000 for casting, and USD 5,300 for casting with therapeutic ultrasound. With respect to the financial burden to society, the mean associated costs were USD 12,500 for reamed intramedullary nailing, USD 13,300 for casting with therapeutic ultrasound, USD 15,600 for operative management by non-reamed intramedullary nailing, and USD 17,300 for casting alone.

INTERPRETATION

Our analysis suggests that, from an economic standpoint, reamed intramedullary nailing is the treatment of choice for closed and open grade I tibial shaft fractures. Considering financial burden to society, there is preliminary evidence that treatment of low-energy tibial fractures with therapeutic ultrasound and casting may also be an economically sound intervention.

[Tibia nonunion after intramedullar nailing for fracture: decortication and osteosynthesis by medial plating]

PURPOSE OF THE STUDY

Intramedullar nailing is now widely used for fractures of the tibia. Extension of nailing indications to proximal, distal, and comminuted fractures has led to a significant rate of complications. The purpose of this study was to analyze decortication and medial plating for the treatment of tibial nonunion after intramedullary nailing.

MATERIAL AND METHODS

Eighteen cases of aseptic tibial nonunion after nailing for fracture were treated in three women and fifteen men, mean age 39 years (19-57). The initial classification was open (n = 8), segmental (n = 3), single-focus (n = 15). The fracture site was inferior (n = 6), middle (n = 7), and superior (n = 2). Primary nailing used reaming in 15 cases (83%), unreamed in 3 (17%) static in 13 and dynamic in 5. Four plaster cabts were also applied. Complications were: infection (n = 1), compartmental syndrome (n = 2), tibial nerve palsy (n = 1), dysesthesia (n = 2), and protrusion of the nail into the knee (n = 1). Dynamization was performed in 11 patients, one with additional bone graft and fibulectomy. Repeated reamed nailing was performed in one patient. Seven nonunions were atrophic and 11 were hypertrophic. There were 13 malpositionings associated with the nonunion. Treatment of the nonunion was performed 300 days on average (90-900) after nailing: cancellous bone graft was associated with decortication in four cases because of bone loss (n = 3) or atrophic nonunion (n = 1).

RESULTS

Union rate was 94%. Mean time for union was 108 days (80-180) with no significant difference (Student t-test) between atrophic (119 days) and hypertrophic (103 days) nonunion. Correction of the malposition was incomplete in seven patients, with angular malunion of less than 6 degrees in five patients and greater than 10 degrees in two. One late infection occurred and finally healed after external fixation and antibiotic therapy. No skin necrosis occurred. Five patients had pain on the hardware. Removal was performed in one time and pain resolved. Improvement of knee and ankle stiffness was achieved in all patients.

DISCUSSION

This technique has been used in our department since 1967. Different studies have found a union rate ranging from 94% to 100% with this procedure. Intramedullary nailing, sometimes associated with bone graft or decortication, is also used for tibial nonunion with a good rate of union. The main problem of intramedulary nailing for nonunion, as for fracture, is the difficulty in avoiding malunion. Plating a nonunion, as a fracture, enables better reduction. Skin problems can occur with the medial plate if the soft tissues are damaged. This situation is very uncommon in secondary surgery.

CONCLUSION

Decortication and medial plating was a safe and efficient treatment for tibia nonunion after failure of intramedullary nailing and allows better reduction and repeated nailing.

Distal intramedullary nail interlocking: the flag and grid technique

Distal interlocking in intramedullary nailing of long bone fractures accounts for a significant proportion of the total fluoroscopy and operative time. We describe a modification of the "perfect circles" freehand technique employing a metallic grid temporarily attached to the skin of the lateral surface of the femur or to the medial surface of the tibia that acts as a fixed "navigational" aid. The position of the distal nail holes in relation to the grid is fluoroscopically ascertained. Subsequently, under fluoroscopic control, a modified Steinmann pin with a metallic handle attached to its blunt end ("flag") is used to accomplish targeting and to create the screw holes, affording improved visualization. This technique was compared with the traditional freehand technique in 2 groups of patients. Use of the modified technique led to reduction of radiation exposure and total distal interlocking time, and there were no significant complications related to the technique.

Should the tibia be reamed when nailing?

A systematic review was performed to assess reamed and unreamed tibial nailing. Only prospective, randomised studies comparing reamed and unreamed tibial nailing in adults were included. A literature search found 1200 possible articles. There were seven comparative studies. These articles were independently assessed by all three authors. Three studies met the inclusion criteria. Each outcome measure tested was assessed for heterogeneity. If significant heterogeneity was present, data from the studies was not combined. If there was no significant heterogeneity, a combined odds ratio was calculated using a fixed effects model and a Z-test was performed to test the overall effect. Two hundred and ninety-one tibial shaft fractures were entered into the included studies. Two hundred and eighty (96%) were followed up (148 reamed; 132 unreamed). There was an increased non-union rate when the tibia was not reamed (p = 0.02). Screw breakage was more common in the unreamed group (p<0.0001). This study could find little difference in the incidence of other complications following reamed or unreamed tibial nailing.

The thermal effects of intramedullary reaming

OBJECTIVE

To study the effect of tourniquet control on intramedullary reaming.

DESIGN

An experimental prospective nonsurvival animal study was performed using 5 mongrel dogs. A pneumatic tourniquet was randomized to either the right or left hind limb. Tibial intramedullary reaming was performed with progressively larger reamers. Cortical temperatures were measured using thermocouples inserted into the tibial diaphyseal cortex. Thermocouples were connected to an analog to digital converter that output continuous data that was collected on a computer. Upon completion of the procedure, the animals were killed.

RESULTS

The peak and low temperatures for each thermocouple with each reamer passage were recorded. Reamer sizes larger than the internal diameter of the intramedullary canal produced higher peak temperatures. The mean delta t (peak temperature minus low temperature) was calculated for each reamer passage. This measurement represents the overall amount of heat generated during each reamer passage. There were no significant differences between the 2 conditions (P = 0.8, paired t test). Temperatures decreased in between reamer exchange but did not return to baseline levels.

CONCLUSIONS

Because similar temperatures were measured both with and without a tourniquet, the risk of thermal necrosis appears to be related more to the process of intramedullary reaming than to the tourniquet. Higher temperatures were measured with reamer sizes larger than the internal diameter of the intramedullary canal. Increasing the time interval between the passage of successive reamers may allow heat to dissipate and decrease the risk of thermal necrosis. The clinical practice of limited reaming ("ream-to-fit") should minimize the occurrence of this complication.

Rotational malalignment of the tibia following reamed intramedullary nail fixation

OBJECTIVE

To determine the incidence and severity of tibial malrotation following reamed intramedullary nail fixation as measured by computerized tomography and to determine the repeatability of computed tomography measurement in the assessment of rotational malreduction.

DESIGN

Prospective cohort.

SETTINGS

Level 1 trauma center.

PARTICIPANTS

Twenty-five consecutive patients with 25 tibial shaft fractures.

INTERVENTION

All patients were treated with reamed intramedullary nailing. Appropriate radiographs and a postoperative lower extremity computed tomography scan were obtained for each patient who consented to the study.

MAIN OUTCOME MEASURE

Rotational alignment of affected tibia as compared to a version of the normal contralateral limb. Malrotation was defined as an internal/external rotation deformity greater than 10degrees.

RESULTS

Malrotation, comparing the fractured limb to normal limb, was determined using a similar measurement method previously described in the literature. Two patients declined inclusion, and in one case, the computed tomography was not acceptable for analysis. Malrotation, comparing the fractured limb to the normal limb, was determined using the measurements from axial computed tomography images. Results revealed a mean absolute rotational difference of 6.7degrees (SD +/-6.3degrees). Rotational malreduction ranged from 15degrees of internal rotation to 22degrees of external rotation. Five of the 22 tibia (22%) were malrotated greater than 10degrees. A larger degree of deformity was seen with certain injury patterns. The intraobserver and interobserver repeatability testing revealed a mean absolute difference between paired malrotation calculations of 3.4degrees and 3.9degrees, respectively, and a repeatability coefficient of 8degrees for both.

CONCLUSION

Computed tomography measurement is a repeatable method of assessing tibial torsion and in this study revealed a significantly higher incidence of rotational malreduction than that previously reported in the literature.

Should insertion of intramedullary nails for tibial fractures be with or without reaming? A prospective, randomized study with 3.8 years' follow-up

OBJECTIVE

To determine if any differences exist in healing and complications between reamed and unreamed nailing in patients with tibial shaft fractures.

DESIGN

Prospective, randomized.

SETTING

Level 1 trauma center.

PATIENTS

Forty-five patients with displaced closed and open Gustilo type I-IIIA fractures of the central two thirds of the tibia.

INTERVENTION

Stabilization of tibial fractures either with a slotted, stainless steel reamed nail or a solid, titanium unreamed nail.

MAIN OUTCOME MEASUREMENTS

Nonunions, time to fracture healing, and rate of malunions.

RESULTS

The average time to fracture healing was 16.7 weeks in the reamed group and 25.7 weeks in the unreamed group. The difference was statistically significant (P = 0.004). There were three nonunions, all in the unreamed nail group. Two of these fractures healed after dynamization by removing static interlocking screws. The third nonunion did not heal despite exchange reamed nailing 2 years after the primary surgery and dynamization with a fibular osteotomy after an additional 1 year. There were two malunions in the reamed group and four malunions in the unreamed group. There were no differences for all other outcome measurements.

CONCLUSION

Unreamed nailing in patients with tibial shaft fractures may be associated with higher rates of secondary operations and malunions compared with reamed nailing. The time to fracture healing was significantly longer with unreamed nails.

Predictors of reoperation following operative management of fractures of the tibial shaft

BACKGROUND

Accurate prediction of likelihood of reoperation in patients with tibial shaft fractures would facilitate optimal management. Previous studies were limited by small sample sizes and noncomprehensive examination of possible risk factors.

OBJECTIVE

We conducted an observational study to determine which prognostic factors were associated with an increased risk of reoperation following operative treatment in a heterogeneous population of patients with tibial shaft fractures.

DESIGN

Retrospective observational study.

SETTING

Level 1 trauma center.

METHODS

We identified 200 patients with tibial shaft fractures from two university-affiliated centers. Two reviewers independently abstracted data regarding 20 possible prognostic variables, reviewed preoperative and postoperative radiographs, and documented reoperations (defined as any surgical procedure </=1 year after the initial surgery that was aimed specifically at achieving bony union of the fracture, including bone grafts, implant exchanges, or débridement for infections). We chose a Cox proportion hazards model to conduct a survival analysis for time to reoperation and constructed a multivariable model to estimate the relative risk of reoperation and associated 95%confidence interval (CI) for each predictor variable.

MAIN OUTCOME MEASURES

Time to reoperation following the initial surgery.

RESULTS

Complete follow-up information was available for 192 of 200 (96%) patients. Three variables predicted reoperation: the presence of an open fracture wound (relative risk 4.32, 95% CI 1.76 to 11.26), lack of cortical continuity between the fracture ends following fixation (relative risk 8.33, 95% CI 3.03 to 25.0), and the presence of a transverse fracture (relative risk 20.0, 95% CI 4.34 to 142.86).

CONCLUSIONS

We identified a set of three simple prognostic variables (open fracture, transverse fracture, and postoperative fracture gap) that can assist surgeons in predicting reoperation following operative treatment of tibial shaft fractures.

Bone formation following intramedullary femoral reaming is decreased by indomethacin and antibodies to insulin-like growth factors

OBJECTIVE

We aimed to: 1). compare rates of in vitro bone formation following reamed and nonreamed intramedullary fixation in a murine model of femoral fracture healing; and 2). examine whether antibodies to insulin-like growth factor (IGF) I, IGF II, or indomethacin (an inhibitor of the inflammatory process) affect bone formation following intramedullary reaming.

DESIGN

Experimental study.

PARTICIPANTS

Twenty-four C57 black mice were randomized to two groups: reamed ( = 12), and nonreamed intramedullary nail insertion ( = 12).

INTERVENTION

In the reamed group, the femoral canals were successively reamed with 30-, 27-, 25-, and 23-gauge stainless steel pins and stabilized with a 27-gauge pin. In mice randomized to the nonreamed group, a 27-gauge pin was inserted. An external three-point bending force created a midshaft transverse femoral fracture. Seven days postsurgery, each mouse was killed, and the right femur was removed. Following pin removal, the callus was minced, the bone marrow was removed, and both were ultracentrifuged at 1200 rpm for 5 minutes. The supernatent was cocultured with 3-day-old murine calvarial cells in culture media. At day 5 of culture, reamed plasma and calvarial cell cocultures were exposed to either 1.0 micro g/mL of anti-IGF I, 1.0 micro g/mL of anti-IGF II, 2 micro M indomethacin, or served as controls (calvarial cells only). The cells were cultured for a total of 21 days.

MAIN OUTCOME MEASUREMENTS

The number of bone nodules was quantified by light microscopy.

RESULTS

Reamed pin insertion resulted in 4.1-fold and 8.9-fold increases in the mean number of bone nodules compared to pins inserted without reaming and controls, respectively (399 +/- 40.0 vs. 97.0 +/- 21.0, < 0.001). The positive effect of intramedullary reaming on bone nodule formation was reversed with the administration of antibodies to IGF I and IGF II. The addition of anti-IGF I or anti-IGF II to calvarial, or osteoblastlike, cells treated with supernatent from the callus and bone marrow of mice with prior intramedullary reaming resulted in significant declines in the mean number of bone nodules ( < 0.001). Specifically, treatment of osteoblastlike cells with anti-IGF I or anti-IGF II resulted in 7.0-fold and 5.4-fold declines in mean bone nodule formation compared to cells without such treatment.

CONCLUSIONS

Intramedullary reaming prior to pin insertion resulted in a significantly greater number of bone nodules than pin insertion only. Antibodies to IGF I, IGF II, and indomethacin reversed the stimulatory effect of reaming on bone nodule formation, suggesting their role in modulating the course of fracture healing following intramedullary reaming.

Current practice in the intramedullary nailing of tibial shaft fractures: an international survey

BACKGROUND

Tibial fractures are the most common of all long bone fractures. Although many tibial fractures may be managed conservatively, a certain subset, including unstable fractures and open fractures, require operative stabilization. Intramedullary nails have become the popular choice of implant in the treatment of tibial shaft fractures. The variability in outcomes with tibial shaft fractures may reflect technical aspects of the surgical procedure and perioperative care regimens among surgeons. Identifying the distribution of surgeons' preferences in nailing technique, and the rationale for their choices, will aid in focusing educational activities for the orthopedic community and planning future clinical trials. Our objectives were to clarify surgeons' opinions regarding technical aspects of surgery and perioperative care after intramedullary nailing of closed and open tibial shaft fractures, and to identify predictors of surgeons' preferences in technique and perioperative care.

METHODS

This study was a cross-sectional survey using focus groups, key informants, and sampling to redundancy strategies to develop a survey to examine surgeons' preferences in the treatment of tibial shaft fractures. The survey was pilot tested for clarity and content validity. We mailed this survey in July 2000 to 577 orthopedic surgeons who have an interest in trauma care. These were members of the Orthopaedic Trauma Association, American Academy of Orthopaedic Surgeons, or European AO International affiliated trauma centers. We used several strategies to improve response rates including personalized cover letters, stamped return envelopes, follow-up telephone calls, and repeat mailing of questionnaires. Main outcome measures included technical issues such as reduction, exposure, intramedullary reaming, and interlocking screws; and factors associated with surgeons' preferences such as age, fellowship, academic practice, and geographic location.

RESULTS

Four hundred forty-four surgeons (77%) responded. Sixty percent of respondents had an academic practice, 84% supervised residents, and 65.1% had fellowship training in trauma. Approximately half (51.5%) of surgeons used a tourniquet. The odds that a surgeon in Asia or Africa used tourniquets was 10 times that of a North American surgeon (p = 0.004 and p = 0.002, respectively). Patellar tendon retraction and an inferior-based entry portal was the popular choice among surgeons (70.1% and 70.8%, respectively). Surgeons from Australia (odds ratio [OR] = 50, p < 0.001), South America (OR = 9.0, p < 0.001), Europe (OR = 3.7, p = 0.001), and Asia (OR = 3.8, p = 0.006) were significantly more likely to use a patellar splitting approach compared with North American surgeons. In the perioperative care of open tibial shaft fractures, there was consensus in the use of intravenous antibiotics and wound irrigation (96.5% and 95.6%, respectively). However, we found considerable variability in surgeons' preference in wound irrigation pressures (high, 38.7%; low, 45.4%). Surgeons in South America were 10 times more likely to use low-pressure irrigation than North American surgeons (p = 0.0005). In grade IIIB open tibial shaft fractures, 94% of surgeons believed wound closure should be obtained within the first 7 days after the injury. A surgeon's geographic location was a significant predictor of the timing of soft tissue coverage (p = 0.001).

CONCLUSION

Consensus in the use of irrigation and intravenous antibiotics in open fractures was achieved among surgeons. However, there remains considerable variability in the surgical technique of intramedullary nailing, the duration of antibiotic use, and the timing of wound closure in open tibial fracture care. Continued education and large multicenter trials are needed to establish best practice in the operative treatment of tibial shaft fracture.

Three-dimensional assessment of tibial malunion after intramedullary nailing: a preliminary study

OBJECTIVES

The purpose of this study was twofold: (a) to introduce a new three-dimensional digital assessment technique for the estimation of angular and rotational malunion and (b) to determine if an association exists between tibial malunion and functionally defined post-traumatic degeneration at the knee and ankle joint.

DESIGN

Nonrandomized, cohort study, with 5.46 years (range 2 to 10 years) of follow-up. Subjects underwent a novel three-dimensional technique to determine the functional mechanical axis of both the knee and tibiotalar joints. Both the affected and unaffected limbs were tested. Differences between both limbs provided assessment of malunion in three planes with 1.8 +/- 0.1 percent (mean +/- SD) reliability. Patients completed the Western Ontario McMaster University Osteoarthritis Index, the Lower Extremity Functional Scale, and the Assessment System of Lower Extremity Function. Standard postoperative radiographs were also examined for evidence of malunion.

SETTING

University-based Level 1 trauma center.

PATIENTS

Seventy-one subjects with an isolated tibial fracture repaired with intramedullary nails were identified; thirteen met eligibility criteria for study inclusion.

RESULTS

A total of 77 percent of the patients (mean follow-up 5.5 years, range 2 to 10 years) were malaligned in one or more of the three planes examined (malunion conventionally defined as >or=10 rotation, >or=5 varus-valgus, and >or=10 procurvatum-recurvatum). Mean varus-valgus deformity was 11.8 +/- 6.3 degrees, mean procurvatum-recurvatum deformity was 3.2 +/- 2.5 degrees, and medial-lateral rotational deformity was 9.6 +/- 4.7 degrees. There was no significant correlation (p > 0.05) between the overall alignment of the involved leg (intertibial difference) in any of the three directional planes and the subject's response to any of the three functional outcome scales used. Three-dimensional analysis differed significantly from radiographic interpretation when malunion occurred in the coronal plane (p = 0.0003).

CONCLUSIONS

This study suggests that failure to meet conventionally accepted standards for tibial alignment might be common. Fortunately, these values were not associated with adverse functional outcomes. A three-dimensional system, which determines the functional mechanical axis of the knee and tibiotalar joints, may be a valuable and reliable method by which to determine malunion after fracture fixation.

Temperature rise during reamed tibial nailing

The current study determined the temperature rise during reamed tibial intramedullary nailing in vivo. Eighteen adult patients were studied. The tibial medullary canal diameter ranged from 8 to 11 mm and was reamed to at least 1.5 mm above the required nail diameter with AO reamers. Reaming of the medullary cavity ranged from 9 to 12 mm before nail insertion. Intraoperative monitoring of the heat produced during reaming of the medullary cavity was done by inserting two platinum resistance thermometer probes into the cortical bone at the short isthmic segment of the tibial shaft. The probes were connected to a data logger, and temperature readings were taken every 5 seconds during each reaming procedure. The mean tibial temperature before initiation of reaming was 35.6 degrees C (standard deviation, +/- 0.5 degrees), and peak temperatures recorded were from 36.1 degrees C to 51.6 degrees C. A direct correlation was observed between temperature elevation and amount of reaming. With reaming above 10 mm, tibias with a canal diameter of 8 mm showed a statistically higher temperature rise compared with tibias with a canal diameter of 9, 10, or 11 mm. No patients had intraoperative or postoperative complications related to skin or bone thermal necrosis, and bony healing progressed uneventfully. The small amount of reaming required to insert a nail into a normal 9-, 10-, or 11- mm tibial canal does not seem to produce a clinical problem. Reaming smaller canals (8 mm) to a larger size may induce a significant heating effect.

Anatomic assessment of the proper insertion site for a tibial intramedullary nail

OBJECTIVES

To locate the proper insertion point for a tibial intramedullary nail in the coronal plane.

DESIGN

Fifty-seven cadaveric lower legs were disarticulated at the knee and ankle and stripped of their soft tissue. Each tibia was nailed in a retrograde fashion through the center of the tibial plafond with a seven-millimeter sharp-tipped rod through the proximal tibia. The exit point of the nail was measured in the coronal plane in relation to the tibial tubercle.

RESULTS

Except for one tibia, the intramedullary nail exit point was always located medial to the center of the tibial tubercle with the average being eight millimeters +/- six millimeters medial to the center of the tibial tubercle. Forty-six percent of the nails exited medial to the whole tibial tubercle.

CONCLUSIONS

The insertion point of a tibial nail should be over the medial aspect of the tibial tubercle in the coronal plane. Our data supports using a medial or patellar splitting approach for nail insertion. Insertion sites lateral to the tibial tubercle should be avoided.

High-energy tibial shaft fractures

High-energy tibial fractures are common injuries that are managed by most practicing orthopaedic surgeons. Many methods of treatment are available. This article reviews the options for skeletal stabilization, the risks and benefits of each, and the necessary concepts that effect outcome.

A new modular testing system for biomechanical evaluation of tibial intramedullary fixation devices

This biomechanical study was performed to evaluate a new modular, tibial testing system developed for analysis of tibial nails and their locking screws.A new testing system, consisting of five modules, was designed to simulate a tibia. For this study one module was removed to simulate a 55-mm distal tibial defect inducing maximum loading on the distal portion of the implant and locking bolts. The tibial load offsets were 23 mm proximally and 10 mm distally medial to the centreline of the tibial shaft to simulate the location of the expected resultant load during the peak loading and inversion torque on the ankle during the gait cycle. Four solid tibial nails (STN, Stryker-Howmedica-Osteonics, Kiel, Germany) were tested to static failure and 15 nails were tested dynamically. Our results showed that the solid tibial nails fractured in the testing device in the same manner and location as they do in clinical series. Evaluation of the results showed the mean fatigue limit of the STN to be 1.4 kN for 500,000 cycles with a standard deviation (S.D.) of 0.33 kN. This biomechanical study establishes a standard technique for the biomechanical testing of tibial nails, in a clinically relevant manner, avoiding the inconsistency of cadaver bone tests. As it is a standardised test set-up this new modular testing system could serve as a standard by which small diameter tibial nails and other devices could be evaluated and compared with other systems currently in use.

Rates and odds ratios for complications in closed and open tibial fractures treated with unreamed, small diameter tibial nails: a multicenter analysis of 467 cases

OBJECTIVE

A multicenter trial analyzed complications and odds for complications in open and closed tibial fractures stabilized by small diameter nails.

DESIGN

Retrospective.

SETTING

Four Level I trauma centers.

PATIENTS

Four hundred sixty-seven tibial fractures were included in the study. There were fifty-two proximal fractures, 219 midshaft fractures, and 196 distal fractures. Breakdown into different AO/OTA groups showed 135 Type A fractures, 216 Type B fractures, and 116 Type C fractures. Two hundred sixty-five were closed fractures and 202 were open fractures.

OUTCOME MEASUREMENTS

Clinical and radiographic analysis.

METHODS

467 patients' tibial fractures were stabilized with small diameter tibial nails using an unreamed technique. Indications for the use of small diameter tibial nails using an unreamed technique included all types of open or closed diaphyseal fractures. The operating surgeons decided whether or not to ream based on personal experience, fracture type, and soft-tissue damage. Surgeons of Center 1 preferred to treat AO Type A and B fractures with unreamed nails, and surgeons of Centers 2, 3, and 4 preferred to treat AO Type B and C fractures with unreamed nails. Closed and open fractures were treated in approximately the same ratio.

RESULTS

Analysis showed five (1.1 percent) deep infections (with a 5.4 percent rate of deep infections in Gustilo Grade III open fractures), forty-three delayed unions (9.2 percent), and twelve (2.6 percent) nonunions. Compartment syndromes occurred in sixty-two cases (13.3 percent), screw fatigue in forty-seven cases (10 percent), and fatigue failure of the tibial nail in three cases (0.6 percent).

CONCLUSIONS

Fracture distraction of more than three millimeters should not be tolerated when stabilizing tibial fractures with unreamed, small-diameter nails as this increases the odds of having a delayed union by twelve times (p < 0.001) and a nonunion by four times (p = 0.057). There was a significant increase of complications in the group of Grade III open fractures (p < 0.001), AO/OTA Type C fractures (p = 0.002), and to a lesser extent in distal fractures. However, the rate of severe complications resulting in major morbidity was low.

Mechanical boundary conditions of fracture healing: borderline indications in the treatment of unreamed tibial nailing

Unreamed nailing favors biology at the expense of the achievable mechanical stability. It is therefore of interest to define the limits of the clinical indications for this method. The extended usage of unreamed tibial nailing resulted in reports of an increased rate of complications, especially for the distal portion of the tibia. The goals of this work were to gain a thorough understanding of the load-sharing mechanism between unreamed nail and bone in a fractured tibia, to identify the mechanical reasons for the unfavorable clinical results, and to identify borderline indications due to biomechanical factors. In a three-dimensional finite element model of a human tibia, horizontal defects were stabilized by means of unreamed nailing for five different fracture locations, including proximal and distal borderline indications for this treatment method. The loading of the bone, the loading of the implant and the inter-fragmentary strains were computed. The findings of this study show that with all muscle and joint contact forces included, nailing leads to considerable unloading of the interlocked bone segments. Unreamed nailing of the distal defect results in an extremely low axial and high shear strain between the fragments. The results suggest that mechanical conditions are advantageous to unreamed nailing of proximal and mid-diaphyseal defects. Apart from biological reasons, clinical problems reported for distal fractures may be due to the less favorable mechanical conditions in unreamed nailing. From a biomechanical perspective, the treatment of distal tibial shaft fractures by means of unreamed nailing without additional fragment contact or without stabilizing the fibula should be carefully reconsidered.

Compartment syndrome: when it is least expected

Compartment syndrome, if not identified and acted upon early, will result in irreversible damage to neuromuscular soft tissues. Therefore, orthopaedic nurses must be aware of the risks, signs and symptoms, unusual circumstances, and appropriate medical and nursing interventions with this syndrome. Usually compartment syndrome is considered to occur with fractures of the tibia, the forearm, or in vascular injuries or burns where there is significant edema. Not as common are compartment syndromes that occur after intramedullary nailing, in the thigh or upper arm, or in the presence of fracture blisters. These unexpected compartment syndromes each occurred only once in the author's many years as an orthopaedic clinical nurse specialist at a major trauma center. However, in each case, the situation and actions were significant. Compartment syndrome will be reviewed with supporting current literature. Each scenario will then be analyzed in terms of the particular considerations surrounding the diagnosis, treatment and nursing implications with the compartment syndrome.

Initial rotational stability of distal tibial fractures nailed without proximal locking: the importance of fracture type and degree of cortical contact

Although distally locked (dynamic) nailing is generally recommended for fractures below the isthmus of the tibia in the presence of adequate proximal nail-bone contact, rotational stability in the above situation appears to be a major concern and can increase the risk of malunion. However, there is no published experimental evidence to quantify this mechanical parameter or to relate factors such as the fracture pattern with the final clinical outcome. This in-vitro biomechanical experimental study was set out to measure the initial rotational stability of dynamically nailed fractures of the distal tibial diaphysis. Using a composite tibial model, three non-comminuted types (spiral, oblique and transverse) and various comminuted patterns (comminution, 0-85%) of dynamically nailed fractures of the distal tibial diaphysis were tested. Using a special rig to simultaneously apply axial and torsional loading measurements of torsional stiffness and the previously described "spring-back angle" were carried out. Our results showed that in terms of torsional stiffness and the "spring-back" angle oblique fractures are the most stable followed by transverse and spiral fractures. Furthermore, when testing of the above parameters against the degree of comminution was carried out, a significant reduction of rotational stability was evident with comminution of 50% or above. It is concluded that oblique fractures of the distal tibial third that can be reduced with at least 50% cortical apposition present the optimal rotational stability following dynamic nailing.

Interlocking intramedullary nailing in distal tibial fractures

This retrospective study examined the results of non-pilon fractures of the distal part of the tibia treated with interlocking intramedullary nailing. Seventy-three patients with equal numbers of fractures treated surgically between 1990 and 1998 were reviewed. Mean patient age was 39.8 years, and follow-up averaged 34.2 months. The AO fracture classification system was used. Concomitant fractures of the lateral malleolus were fixed. All but three fractures achieved union within 4.2 months on average. Satisfactory or excellent results were obtained in 86.3% of patients. These results indicate interlocking intramedullary nailing is a reliable method of treatment for these fractures and is characterized by high rates of union and a low incidence of complications.

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.

Development of small diameter intramedullary nails made from ISO 5832-9 stainless steel

BACKGROUND

In order to improve strength in small diameter intramedullary nails, a system was designed in which the implants were manufactured from 30% coldworked ISO 5832-9 stainless steel.

METHODS

Nail diameters were 9 and 10 mm for the femur, and 8 and 9 mm for the tibia. The nails were solid rods and the screws were partially threaded. Pre-clinical bending yield tests established that the 8-, 9- and 10-mm diameter rods had strengths comparable, respectively, with 10-, 12- and 14-mm diameter Grosse-Kempf nails. Forty-eight femoral and 98 tibial shaft acute fractures were treated with this system. Postoperatively, patients were allowed to gently bear weight as tolerated.

RESULTS

There was one broken nail, occurring 10 months after femoral nailing. There were six broken screws, occurring between 3 and 6 months postoperatively in two patients and after more than 6 months in four patients. The broken screws had no adverse clinical effect. Five patients required late bone grafting or exchange nailing, and 15 patients required dynamization.

CONCLUSION

This design of small diameter locked intramedullary nails was strong enough to allow early weightbearing.

Reamed versus nonreamed intramedullary nailing of lower extremity long bone fractures: a systematic overview and meta-analysis

OBJECTIVE

To determine the effect of reamed versus nonreamed intramedullary (IM) nailing of lower extremity long bone fractures on the rates of nonunion, implant failure, malunion, compartment syndrome, pulmonary embolus, and infection.

DESIGN

Quantitative systematic review of prospective, randomized controlled trials.

DATA IDENTIFICATION

MEDLINE and SCISEARCH computer searches provided lists of published randomized clinical trials from 1969 to 1998. Extensive hand searches of major orthopaedic journals, bibliographies of major orthopaedic texts, and personal files identified additional studies.

STUDY SELECTION AND DATA EXTRACTION

Of 676 citations initially identified, sixty proved potentially eligible, of which four published and five unpublished randomized trials met all eligibility criteria. Each of three investigators assessed study quality and abstracted relevant data.

RESULTS

The pooled relative risk of reamed versus nonreamed nails (nine trials, n = 646 patients) was 0.33 [95% confidence interval (CI), 0.16 to 0.68; p = 0.004]. The absolute risk difference in nonunion rates with reamed IM nailing was 7.0 percent (95% CI, 1 to 11 percent). Thus, one nonunion could be prevented for every fourteen patients treated with reamed IM nailing [number needed to treat (NNT) = 14.28]. The risk ratios for secondary outcome measures were: implant failure, 0.30 (95% CI, 0.16 to 0.58; p < 0.001); malunion, 1.06 (95% CI, 0.32 to 3.57); pulmonary embolus, 1.10 (95% CI, 0.26 to 4.76); compartment syndrome, 0.45 (95% CI, 0.13 to 1.56); and infection, 0.98 (95% CI, 0.21 to 4.76). Sensitivity analyses suggested that reported rates of nonunion and implant failure were higher in studies of lower quality. The type of long bone fractured (tibia or femur), the degree of soft tissue injury (open or closed), study quality, and whether a study was published or unpublished did not significantly alter the relative risk of nonunion between reamed and nonreamed IM nailing.

CONCLUSIONS

There is evidence from a pooled analysis of randomized trials that reamed IM nailing of lower extremity long bone fractures significantly reduces rates of nonunion and implant failure in comparison with nonreamed nailing.