Robert F. Ostrum

A critical analysis of the eccentric starting point for trochanteric intramedullary femoral nailing.

Objectives: Antegrade femoral intramedullary nailing through a greater trochanteric insertion site has been proposed for the treatment of subtrochanteric fractures. The currently available trochanteric nails have dissimilar characteristics, and the most appropriate insertion site for satisfactory subtrochanteric fracture alignment has not been determined. This study is an analysis of 5 different trochanteric femoral nails and 3 different insertion sites using a cadaveric model of a reverse obliquity subtrochanteric femur fracture to determine the optimal trochanteric entry site. Setting: OSHA-approved cadaveric laboratory with an OEC 9800 (General Electric Company, Fairfield, CT) fluoroscopic C-arm. Methods: Twenty-one embalmed human cadaveric femurs were stripped of soft tissues. Three different starting points on the anteroposterior radiograph were used: at the tip of the greater trochanter, and 2 to 3 mm medial and lateral to the tip. A reverse obliquity subtrochanteric fracture was created. The Trochanteric Antegrade Nail (TAN), Gamma nail (2nd and 3rd generations), Trochanteric Fixation Nail (TFN), and the Holland Nail were then inserted. The proximal bend and radius of curvature were calculated for each nail. Varus and valgus angulation as well as lateral gapping were measured on radiographs; also calculated were the mean, range, and standard deviation. Statistical analysis was performed on angulation and gapping at the fracture site by using Fisher least significant differences analysis, based on a 2-way ANOVA test. Results: The Holland nail had a proximal bend of 10° and a radius of 300 cm. TAN was 5° and 350 cm, TFN was 6° and 150 cm, Gamma 2 was 4° and 300 cm, and Gamma 3 was 4° and 200 cm. The tip starting point led to the most neutral alignment regardless of nail. The lateral starting point led to varus with all nails. The medial starting point led to valgus of >6° with the Holland and TFN; Gamma and TAN had better alignment with <4° of valgus. Gapping of the lateral cortex was greatest with a lateral starting point. Conclusions: An analysis of 5 trochanteric intramedullary nails with different proximal bends and 3 different starting points in the greater trochanter showed that the tip of the trochanter is close to the “universal” starting point. In this cadaveric subtrochanteric fracture model, the tip starting point led to the most neutral alignment regardless of nail used. The lateral starting point led to varus and gapping of the lateral cortex with all nails. Clinical Relevance: Subtrochanteric fractures treated with a trochanteric antegrade nail should have an acceptable reduction before nail insertion. The tip of the trochanter, or even slightly medial, on anteroposterior fluoroscopy is recommended as the universal starting point for these nails. However, slight deviations from this point and nail geometry can cause fracture site malalignment. A lateral starting point led to varus alignment and should be avoided.

Retrograde Intramedullary Nailing of Femoral Diaphyseal Fractures

OBJECTIVES To prospectively evaluate the results of retrograde intramedullary nailing of femoral shaft fractures. DESIGN Prospective, consecutive series. PATIENTS AND SETTING All patients with a femoral shaft fracture admitted at an urban Level 1 trauma center from December 1995 to December 1996 were treated with a retrograde femoral intramedullary nail. INTERVENTION Retrograde femoral intramedullary nailing was performed on a radiolucent operating room table. Through a three-centimeter medial parapatellar incision, a reamed ten-millimeter retrograde nail was inserted. METHODS From the time of injury until union, the following parameters were assessed: operative time, blood loss, extent of comminution, open grade, associated injuries, Injury Severity Score, body mass index, time to union, secondary procedures, range of motion in the knee. and complications. RESULTS Fifty-seven patients with sixty-one fractures were available for follow-up, which averaged 43.1 weeks. Fifty-two percent of fractures demonstrated Winquist Type 3 or 4 comminution. Twenty-six percent of the fractures were open. Fifty-two fractures healed after the initial nailing, five of seven dynamized nails healed, and one patient with bone loss requiring bone graft united yielding a final union rate of 95 percent. Of the three nonunions (5 percent), two healed with exchange nailing and one remains asymptomatic at seventy-one weeks. One patient developed a late septic knee that resolved with treatment. Excellent range of motion in the knee was obtained by those patients who did not have other ipsilateral limb injuries. CONCLUSIONS This consecutive series had a 95 percent union rate after nailing and dynamization as necessary. No knee problems were associated with the retrograde femoral intramedullary nailing technique. The one septic knee raises concerns about the use of retrograde nailing in severe open femoral shaft fractures. Retrograde femoral nailing should be given serious consideration as an alternative to antegrade femoral nailing.

Effects of Retrograde Femoral Intramedullary Nailing on the Patellofemoral Articulation

OBJECTIVE To determine the patellofemoral contact areas as well as mean and maximal pressures after retrograde intramedullary nailing in a cadaveric model. STUDY DESIGN Pressure-sensitive film was used to analyze patellofemoral joint pressures after insertion of a retrograde femoral nail in a cadaveric specimen. METHODS A retrograde femoral nail was inserted into seven cadaveric knees. Pressure-sensitive film was placed into the patellofemoral joint and physiologic loads (700 newtons) were applied to the knee joint at 90 degrees and 120 degrees of flexion. Testing was performed with the nail three millimeters deep to the cartilage (In), flush with the cartilage (Flush), and one millimeter prominent (Out). The intact knee served as the Control. RESULTS The mean contact areas showed no statistical differences among the four groups. There was a significant increase in mean pressure at 120 degrees and maximum pressure at 90 degrees and 120 degrees for the Out group when compared with the Control, In, and Flush groups (p < 0.001). CONCLUSIONS There were no significant differences in mean contact pressure, contact area, or maximum pressure among the Control, three-millimeter insertion depth, or flush insertion groups. There was, however, a significant increase in mean and maximum pressures with the nail one millimeter prominent. These results indicate that placement of a retrograde femoral intramedullary nail is critical, but that proper placement should not significantly influence the biomechanics of the patellofemoral joint.

Penetration of the distal femoral anterior cortex during intramedullary nailing for subtrochanteric fractures: A report of three cases

Three cases of anterior distal femoral cortex penetration during intramedullary nailing for subtrochanteric fractures are documented. Case 1 involved a Zimmer (Warsaw, IN) M/DN antegrade femoral nail, case 2 a Howmedica (Allendale, NJ) long-stem Gamma nail, and case 3 a Synthes (Paoli, PA) titanium femoral nail with spiral blade locking. The anterior Zimmer nail penetration resulted in a displaced supracondylar fracture, which subsequently required revision. The Gamma nail as well as the Synthes nail were left impaled through the distal femoral cortex, and the subtrochanteric fractures went on to union. The anteroposterior radius of curvature for the Zimmer, the long Gamma, and the Synthes nail are 257 cm, 300 cm, and 150 cm, respectively. It has been estimated that the radius of curvature of the femoral diaphyseal canal is 114 to 120 cm. It appears that the difference in femoral anteroposterior bow between the bone and the implant is a contributing factor to distal femoral anterior cortex penetration in intramedullary nailing of subtrochanteric fractures.

The use of clopidogrel (plavix) in patients undergoing nonelective orthopaedic surgery

Objective: To assess the effects of Plavix on patients requiring nonelective orthopaedic surgery. Design: Retrospective cohort study. Setting: University-affiliated teaching institutions. Patients and Participants: The orthopaedic trauma registry was used to retrospectively identify all patients taking clopidogrel (Plavix; Bristol-Myers Squibb/Sanofi Pharmaceuticals, Bridgewater, NJ) who required nonelective orthopaedic surgery from 2004 to 2008. Twenty-nine patients were identified on Plavix (PG) and 32 matched patients in the control group not taking Plavix (NPG). The Plavix group was separated into those with a surgical delay less than 5 days of the last dose (PG < 5) (n = 28) and a delay greater than 5 days (PG > 5) (n = 1). A randomized age- and injury-matched control group not on Plavix was separated with surgical delay less than 5 days (NPG < 5) (n = 29) and delay greater than 5 days (NPG > 5) (n = 3). Intervention: A retrospective review was performed comparing pre- and postoperative hemoglobin, blood transfusion requirements, surgical delay, 30-day mortality, and postoperative complications. Main Outcome Measurements: Statistical analyses were performed using the Student t test and chi square test to identify differences between the groups. Results: The mean preoperative hemoglobin of the PG and the NPG was 11.2 g/dL and 12.3 g/dL (P = 0.03). Transfusion rates were similar with 18 of 28 in the PG compared with 13 of 29 in the NPG (P = 0.22). The mean surgical delay between the PG and NPG was 1.88 and 1.68 days (P = 0.64). Overall complications between the PG and NPG was nine of 28 and nine of 29 (P = 0.92). In both groups, two patients had postoperative wound drainage, which resolved without intervention. One patient in each group required revision surgery for nonunion. The 30-day mortality in the Plavix group was zero of 28 (0%) compared with one of 29 (3%) in the control group (cardiac arrest) (P = 0.32). Conclusions: In this study, there were no serious complications or increased transfusion requirements in the Plavix group. Avoiding surgical delay for patients on Plavix requiring nonelective orthopaedic surgery appears to be safe. The goal should be early operative intervention to decrease the morbidity and mortality of surgical delay. This is especially true for patients with hip fractures, which was the most common nonelective orthopaedic surgery required of patients on Plavix in this study.

Tension band fixation of medial malleolus fractures

Summary A prospective study on tension band fixation of medial malleolus fractures was performed on 30 consecutive patients with 31 fractures from October 1987 until December 1990. All patients had at least a displaced medial malleolus fracture unreduced by closed methods. The fractures were classified into small, medium and large using a modified Lauge-Hansen classification. There were no nonunions or movement of wires postoperatively and only two patients had subjective complaints with reference to the wires that required hardware removal. There was one 2-mm malreduction and one patient with a wound slough and subsequent osteomyelitis. One fragment had 2 mm of displacement after fixation but went on to union. A biomechanical study was undertaken to compare fixation of the medial malleolus with K wires alone, K wires plus a tension band, and two cancellous screws. The tension band fixation provided the greatest resistance to pronation forces: four times stiffer than the two screws and 62% of the intact specimen. Tension band fixation of the medial malleolus is a biomechanically strong and clinically acceptable method of treatment for displaced medial malleolus fractures. This method of fixation may be especially useful for small fragments and in osteoporotic bone.

A mechanical study of gap motion in cadaveric femurs using short and long supracondylar nails.

Objective: To determine the relative stability achieved in unstable supracondylar femur fractures treated with long (36 cm) and short (20 cm) retrograde intramedullary nails using 1 or 2 proximal locking bolts. We hypothesized that longer nails would reduce fracture site motion compared with short nails and that 2 proximal locking bolts would improve stability compared with 1 proximal locking bolt. Design: Nine pairs of matched human cadaveric femurs were instrumented with 20-cm and 36-cm retrograde intramedullary nails (all 12-mm diameter, Biomet, Warsaw, IN) following reaming to 13 mm. Transverse supracondylar gap (6 mm) osteotomies were created. The femurs were mounted and cyclically tested separately in coronal plane bending and sagittal plane bending on a materials testing system. Fracture site translation was measured using a digital caliper in the respective plane. Setting: Orthopaedic biomaterials laboratory. Results: With 2 proximal locking bolts, average sagittal translation was 7.2 mm and 1.8 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 6.3 mm and 4.3 mm, respectively. With a single proximal locking bolt, average sagittal translation was 7.6 mm and 2.2 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 13.6 mm and 4.4 mm, respectively. A statistically significant difference in fracture site translation was found in each pairing by Student t test (P < 0.005), except coronal translation with 2 proximal locking bolts (P = 0.056). Free-body analysis predicts higher local stresses at the proximal interlocks of the shorter nail. Conclusions: Longer nails provide improved initial fracture stability when compared with short retrograde nails for supracondylar femur fractures due to a more stable mechanical interaction between the femoral diaphysis and the nail. A second proximal locking bolt in the long nail provides no additional stability.

Distal Third Femur Fractures Treated With Retrograde Femoral Nailing and Blocking Screws

Retrograde femoral nailing is a widely used treatment for fractures involving the distal third of the femur. Angular malunion of these fractures after retrograde intramedullary nailing is a known complication. We report our surgical technique and experience using blocking screws to aid in reduction and augment the stability of the fixation when using a retrograde intramedullary nail for distal femoral fractures.

The lack of association between femoral shaft fractures and hypotensive shock.

A retrospective review of all patients with femur fractures was performed to determine whether isolated femoral shaft fractures were associated with hypotensive shock. One hundred patients were identified who had either an isolated femoral shaft fracture (group F, 62 patients) or a femoral shaft fracture in addition to other non-shock producing fractures or minor injuries (group A, 38 patients). No patients in this study were in class III or IV (hypotensive) shock; however, 11% progressed from no shock to class I and 13% from class I to class II. Logistic regression showed no association between class II shock and age, sex, or weight. The presence of additional fractures (p = 0.004) and total fluids received from fracture to stabilization (p = 0.014) had a highly significant association with class II shock in a joint analysis. Mechanism of injury, although significant as an independent variable, was highly associated with the presence of additional fractures and so is not required in the joint model. Femur fractures alone or in combination with other minor injuries should not be considered the cause of hypotensive shock in the traumatized patient. In the traumatized patient who presents with a closed femoral shaft fracture and hypotension, an alternative source of hemorrhage should be sought.

Determination of Radiographic Healing: An Assessment of Consistency Using RUST and Modified RUST in Metadiaphyseal Fractures.

Objective: To determine the reliability of the Radiographic Union Scale for Tibia (RUST) score and a new modified RUST score in quantifying healing and to define a value for radiographic union in a large series of metadiaphyseal fractures treated with plates or intramedullary nails. Design: Healing was evaluated using 2 methods: (1) evaluation of interrater agreement in a series of radiographs and (2) analysis of prospectively gathered data from 2 previous large multicenter trials to define thresholds for radiographic union. Intervention: Part 1: 12 orthopedic trauma surgeons evaluated a series of radiographs of 27 distal femur fractures treated with either plate or retrograde nail fixation at various stages of healing in random order using a modified RUST score. For each radiographic set, the reviewer indicated if the fracture was radiographically healed. Part 2: The radiographic results of 2 multicenter randomized trials comparing plate versus nail fixation of 81 distal femur and 46 proximal tibia fractures were reviewed. Orthopaedic surgeons at 24 trauma centers scored radiographs at 3, 6, and 12 months postoperatively using the modified RUST score above. Additionally, investigators indicated if the fracture was healed or not healed. Main Outcome Measures: The intraclass correlation coefficient (ICC) with 95% confidence intervals was determined for each cortex, the standard and modified RUST score, and the assignment of union for part 1 data. The RUST and modified RUST that defined “union” were determined for both parts of the study. Results: ICC: The modified RUST score demonstrated slightly higher ICCs than the standard RUST (0.68 vs. 0.63). Nails had substantial agreement, whereas plates had moderate agreement using both modified and standard RUST (0.74 and 0.67 vs. 0.59 and 0.53). Union: The average standard and modified RUST at union among all fractures was 8.5 and 11.4. Nails had higher standard and modified RUST scores than plates at union. The ICC for union was 0.53 (nails: 0.58; plates: 0.51), which indicates moderate agreement. However, the majority of reviewers assigned union for a standard RUST of 9 and a modified RUST of 11, and >90% considered a score of 10 on the RUST and 13 on the modified RUST united. Conclusions: The ICC for the modified RUST is slightly higher than the standard RUST in metadiaphyseal fractures and had substantial agreement. The ICC for the assessment of union was moderate agreement; however, definite union would be 10 and 13 with over 90% of reviewers assigning union. These are the first data-driven estimates of radiographic union for these scores.