John W. Munz

Early Mechanical Failures of the Synthes Variable Angle Locking Distal Femur Plate.

Objectives: To document the high failure rate of a specific implant: the Synthes Variable Angle (VA) Locking Distal Femur Plate. Design: Retrospective. Setting: Urban University Level I Trauma Center. Patient/Participants: All distal femur fractures (OTA/AO 33-A, B, C) treated from March 2011 through August 2013 were reviewed from our institutional orthopaedic trauma registry. Inclusion criteria were fractures treated with a precontoured distal femoral locking plate and age between 18 and 84. Exclusion criteria were fractures treated with intramedullary nails, arthroplasty, non-precontoured plates, dual plating, or screw fixation alone. The population was divided into 3 groups: less invasive stabilization system (LISS) group (n = 21), treated with LISS plates (Synthes, Paoli, PA); locking condylar plates (LCPs) group (n = 10), treated with LCPs (Synthes, Paoli, PA); and VA group (n = 36), treated with VA distal femoral LCPs (Synthes, Paoli, PA). Average age was 54.6 ± 17.5 years. Intervention: Open reduction internal fixation with one of the above implants was performed. Main Outcome Measures: The patients were followed radiographically for early mechanical implant failure defined as loosening of locking screws, loss of fixation, plate bending, or implant failure. Results: There were no statistically significant differences between groups for age, gender, open fracture, mechanism of injury, or medial comminution. There were 3 failures (14.3%) in group LISS, no failures (0%) in group LCP, and 8 failures (22.2%) in group VA. All 3 failures in group LISS were in A-type fractures (2 periprosthetic) and all failures in group VA were in C-type fractures. When all fractures for all 3 groups were compared for failure rate, there was no statistically significant difference (P = 0.23). However, when only 33-C fractures were compared, there was significantly greater failure rate in the VA group (P = 0.03). The mean time to failure in group VA was 147 days (range 24–401 days) and was significantly earlier (P = 0.034) when compared with group LISS (mean 356 days; range 251–433 days). Conclusions: Early mechanical failure with the VA distal femoral locking plate is higher than traditional locking plates (LCP and LISS) for OTA/AO 33-C fractures. We caution practicing surgeons against the use of this plate for metaphyseal fragmented distal femur fractures. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Addition of a Medial Locking Plate to an In Situ Lateral Locking Plate Results in Healing of Distal Femoral Nonunions

BackgroundNonunion of the distal femur after lateral plating is associated with axial malalignment, chronic pain, loss of ambulatory function, and decreased knee ROM. The addition of a medial locking plate with autogenous bone grafting can provide greater stability to allow bone healing and may be used to achieve union in these challenging cases.Questions/PurposesWe wished to determine (1) the proportion of patients who achieve radiographic signs of osseous union for distal femoral nonunions with an in situ lateral plate after treatment with addition of a medial locking plate and autogenous bone grafting, and (2) the frequency and types of complications associated with this treatment.MethodsBetween 2007 and 2013, we treated 22 patients for 23 distal femoral nonunions, defined as an unhealed fracture with no radiographic signs of osseous union at a mean of 16 months (SD, 13 months) after injury. During that time, we used a treatment algorithm consisting of treatment in one or two stages. The single-stage procedure performed in 16 aseptic nonunions with a stable lateral plate involved addition of a medial locking plate and autogenous bone graft. A two-stage treatment performed in seven nonunions with lateral plate failure involved placement of a new lateral locking plate followed by addition of a medial locking plate with autogenous bone graft at least 2 months after the first procedure. Of the 22 patients treated, 20 had a median followup of 18 months (SD, 6–94 months). We defined osseous union by bridging bone on three of four cortices with absence of a radiolucent line or more than 25% cross-sectional area of bridging bone via CT.ResultsTwenty of the 21 nonunions attained radiographic signs of osseous union by 12 months. Six of the 20 patients experienced complications: one patient had a persistent nonunion; four patients underwent removal of symptomatic hardware; and one patient experienced skin breakdown at the bone graft harvest site.ConclusionsA very high proportion of patients achieve union when using medial locking plates to treat distal femoral nonunions after lateral plating of the original injury. Addition of bone graft, staged reconstruction, and revision of the initial lateral plate is indicated when the nonunion is associated with fatigue failure of the initial lateral plate.Level of EvidenceLevel IV, therapeutic study.

Do Transsacral-transiliac Screws Across Uninjured Sacroiliac Joints Affect Pain and Functional Outcomes in Trauma Patients?

BackgroundPatients with pelvic ring displacement and instability can benefit from surgical reduction and instrumentation to stabilize the pelvis and improve functional outcomes. Current treatments include iliosacral screw or transsacral-transiliac screw, which provides greater biomechanical stability. However, controversy exists regarding the effects of placement of a screw across an uninjured sacroiliac joint for pelvis stabilization after trauma.Questions/purposesDoes transsacral-transiliac screw fixation of an uninjured sacroiliac joint increase pain and worsen functional outcomes at minimum 1-year followup compared with patients undergoing standard iliosacral screw fixation across the injured sacroiliac joint in patients who have sustained pelvic trauma?MethodsAll patients between ages 18 and 84 years who sustained injuries to the pelvic ring (AO/OTA 61 A, B, C) who were surgically treated between 2011 and 2013 at an academic Level I trauma center were identified for selection. We included patients with unilateral sacroiliac disruption or sacral fractures treated with standard iliosacral screws across an injured hemipelvis and/or transsacral-transiliac screws placed in the posterior ring. Transsacral-transiliac screws were generally more likely to be used in patients with vertically unstable sacral injuries of the posterior ring as a result of previous reports of failures or in osteopenic patients. We excluded patients with bilateral posterior pelvic ring injuries, fixation with a device other than a screw, previous pelvic or acetabular fractures, associated acetabular fractures, and ankylosing spondylitis. Of the 110 patients who met study criteria, 53 (44%) were available for followup at least 12 months postinjury. Sixty patients were unable to be contacted by phone or mail and seven declined to participate in the study. Outcomes were obtained by members of the research team using the visual analog scale (VAS) pain score for both posterior sacroiliac joints, Short Musculoskeletal Functional Assessment (SMFA), and Majeed scores. Patients completed the forms by themselves when able to return to the clinic. A phone interview was performed for others after they received the outcome forms by mail or email.ResultsThere were no differences between iliosacral and transsacral-transiliac in terms of VAS injured (2.9 ± 2.9 versus 3.0 ± 2.8, mean difference = 0.1 [95% confidence interval, −1.6 to 1.7], p = 0.91), VAS uninjured (1.8 ± 2.4 versus 2.0 ± 2.6, mean difference = 0.2 [−1.3 to 1.6], p = 0.82), Majeed (80.3 ± 19.9, 79.3 ± 17.5, mean difference = 1.0 [−11.6 to 9.6], p = 0.92), SMFA Function (22.8 ± 22.2, 21.0 ± 17.6, mean difference = 1.8 [−13.2 to 9.6], p = 0.29, and SMFA Bother (24.3 ± 23.8, 29.7 ± 23.4, mean difference = 5.4 [−7.8 to 18.6], p = 0.42).ConclusionsPlacement of fixation across a contralateral, uninjured sacroiliac joint resulted in no differences in pain and function when compared with standard iliosacral screw placement across an injured hemipelvis at least 1 year after instrumentation. When needed for biomechanical stability, transsacral-transiliac fixation across an uninjured sacroiliac joint can be used without expectation of positive or negative effects on pain or functional outcomes at minimum 1-year followup.Level of EvidenceLevel III, therapeutic study.

Does Postoperative Radiation Decrease Heterotopic Ossification After the Kocher-Langenbeck Approach for Acetabular Fracture?

BackgroundControversy regarding heterotopic ossification (HO) prophylaxis exists after Kocher-Langenbeck for treatment of acetabular fracture. Prophylaxis options include antiinflammatory oral medications, single-dose radiation therapy, and débridement of gluteus minimus muscle. Prior literature has suggested single-dose radiation therapy as the best prophylaxis to prevent HO formation. However, recent reports have emerged of radiation-induced sarcoma after radiotherapy for HO prophylaxis, which has led many surgeons to reconsider the risks and benefits of single-dose radiation therapy. We set out to determine if radiotherapy, in addition to standard débridement of gluteus minimus muscle, affected postoperative HO formation after a Kocher-Langenbeck approach for acetabular fracture.Questions/purposes(1) After the Kocher-Langenbeck approach and gluteus minimus débridement, is single-dose radiotherapy associated with a decreased risk of HO? (2) Does addition of single-dose radiotherapy prolong length of stay after a Kocher-Langenbeck approach and gluteus minimus débridement as compared with patients without radiotherapy?MethodsAfter institutional review board approval, all adult patients treated for acetabular fracture by a single surgeon with a Kocher-Langenbeck approach between August 2011 and October 2014 were identified (n = 60). Débridement of gluteus minimus muscle caudal to the superior gluteal bundle was standard in all patients. Radiotherapy was given with a single dose of 700 cGy within 72 hours of surgery from August 2011 until April 2013. Patients treated subsequently did not receive radiotherapy. Patients treated with indomethacin (n = 1) and with fewer than 10 weeks followup were excluded (n = 12) because several studies suggest that most HO that develops is visible by that point in time. Our study group totaled 46 patients with 24 in the radiotherapy and débridement group and 22 in the débridement group. Charts were reviewed to determine length of stay. Attending orthopaedic trauma surgeons who were blinded to the patient’s treatment group graded all followup radiographs according to the Brooker system, and Classes III and IV HO were considered clinically important Fisher’s exact test was used to analyze clinically significant differences HO between the two groups. Length of stay was compared using a t-test.ResultsSingle-dose radiotherapy is associated with a decreased risk of clinically important (Brooker III–IV) HO after a Kocher-Langenbeck approach and gluteus minimus débridement (radiotherapy: one of 24 [4%], no radiotherapy: seven of 22 [32%], relative risk: 0.131 [95% confidence interval {CI}, 0.018–0.981], p = 0.020). Addition of single-dose radiotherapy did not result in increased length of stay (radiotherapy: 12 ± 7.0 days; no radiotherapy: 11 ± 7.2 days; mean difference: 1.0 [95% CI, −3.2 to 5.2] days, p = 0.635).ConclusionsSingle-dose radiation in combination with gluteus minimus débridement decreases the risk of clinically important HO compared with gluteus minimus débridement alone after a Kocher-Langenbeck approach for acetabular fracture. No differences in length of stay were seen. Surgeons who chose not to use radiotherapy as a result of concern for future sarcoma may see higher rates of clinically significant HO after a Kocher-Langenbeck approach for acetabular fracture fixation.Level of EvidenceLevel III, therapeutic study.

Locked Plating: Biomechanics and Biology

Since the early ideas of internal fixation, many different concepts and techniques have been developed for the use in fracture surgery. Each technique has been welcomed by many with excitement while others have suggested caution, locked plating is no exception. Since its advent over 15 years ago many have viewed this as a violation of the strict AO principles of anatomic reduction and rigid fixation. Others have looked at it as an extension of the blade plate (single locked plate), that is, an “internal external fixator.” This initial paper will deal with the biomechanics and biology of locked plating as compared with conventional plating. The following paper will suggest some of the clinical indications and the rationale for use of locked plating. In reviewing biomechanical studies, the surgeon must be clear on the model that is used including the number of screws on each side of the fracture, how close the screws are to the fracture site, the length of the plate, how close the plate is to the bone, the material of the plate and the screws, unicortical or bicortical screws, the density of the bone, and the stability of the fracture. Furthermore, the surgeon must understand that more stability does not always equal better healing. Although fractures require a 2% to 10% strain rate to heal, the optimal biomechanics for fracture healing is unknown. Too rigid of fixation can delay healing. A strain rate of >10% may not allow bone to form at the fracture site. Locked plating has different biomechanics in axial loading, bending, and torsion. Biologically, locked plating preserves the blood supply by preventing necrosis under the plate (no compression between the plate and the bone) and allows a more percutaneous insertion. Although locked plating is a useful tool, indiscriminate use will cause the surgeon to lose the fracture-healing race and cause construct failure.

Can Thrombelastography Predict Venous Thromboembolic Events in Patients with Severe Extremity Trauma

Objectives: An elevated maximal amplitude (mA) value with rapid thrombelastography on admission can identify general trauma patients with an increased risk of venous thromboembolic events (VTEs). We hypothesized that (1) the risk of VTE traditionally assigned to injury lies specifically in those who sustain major orthopaedic trauma and (2) an elevated admission mA value could be used to identify patients with major orthopaedic injuries at risk for VTE during initial hospital admission. Design: Retrospective. Setting: University level 1 trauma center. Patients/Participants: Consecutive trauma patients admitted to an urban level 1 trauma center between September 2009 and February 2011 who met the criteria for level 1 trauma activation and who were between 18 and 85 years of age were included in our study group. Two groups were created, one whose extremity abbreviated injury severity score was 2 or greater (ORTHO) and the other whose extremity abbreviated injury severity score was <2 (non‐ORTHO). Main Outcome Measurements: Pulmonary emboli were confirmed by computed tomography angiography, and deep vein thromboses were confirmed by venous duplex. Univariate analyses were conducted and followed by purposeful regression analysis. Results: Of note, 1818 patients met the inclusion criteria (310 ORTHO and 1508 non‐ORTHO). Despite more hypocoagulable r‐TEG values on arrival (alpha angle 71 vs. 73 and mA 62 vs. 64, both P < 0.05), ORTHO patients had higher rates of VTE (6.5% vs. 2.7%, P < 0.001). Stepwise regression generated 4 values to predict development of VTE (age, male gender, white race, and ORTHO). After controlling for these variables, admission mA values >=65 (odds ratio 3.66) and >=72 (odds ratio 6.70) were independent predictors of VTEs during hospitalization. Conclusions: Admission rapid thrombelastography mA values can identify patients with major orthopaedic trauma injuries who present with an increased risk of in‐hospital deep vein thromboses and pulmonary embolism with a 3.6‐fold and 6.7‐fold increased risk for mA values >=65 and >=72, respectively. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Do Safe Radiographic Sacral Screw Pathways Exist in a Pediatric Patient Population and Do They Change With Age

Objectives: Iliosacral screw pathways in the first (S1) and second (S2) sacral segments are commonly used for adult pelvic ring stabilization. We hypothesize that radiographically “safe” pathways exist in pediatric patients. Setting: Academic level I Trauma Center. Patients: All patients between ages 2 and 16 years with a computed tomography scan including the pelvis obtained over a 6-week period (174 children, mean age 10.8 ± 3.9 years; 90 boys, 84 girls). Intervention: The width and height at the “constriction point” in 3 safe screw pathways were measured bilaterally by 3 orthopaedists (resident, trauma fellow, trauma attending). Pathways corresponding to: (1) an “iliosacral” screw at S1, a “trans-sacral trans-iliac” (TSTI) screw at S1, and a TSTI screw at S2. Main Outcome Measurements: (1) Mean width and height of pathways, (2) interrater reliability coefficient, (3) availability of pathways greater than 7 mm, (4) growth of pathways with age, (5) sacral morphology. Results: The interrater reliability coefficient was above 0.917 for all measurements. Radiographically safe pathways were available for 99%, 51%, and 89% of children for iliosacral screws at S1 (width 16.4 ± 2.8 mm, height 15.1 ± 3.3 mm), TSTI screws at S1 (width 7.2 ± 4.9 mm, height 8.3 ± 5.6 mm), and TSTI at S2 (width 9.3 ± 2.2 mm, height 11.5 ± 2.7 mm), respectively. Conclusions: Contrary to our hypothesis, almost all children aged 2–16 had a radiographically safe screw pathway for an iliosacral screw at S1, and most of the children had an available pathway for a TSTI screw at S2. However, only 51% had a pathway for a TSTI screw at S1.

Locked Plating: Clinical Indications

Summary: As shown in the previous article, locked plating stabilizes fractures differently than conventional plating using different mechanical principles. Although the blade plate is a form of a locked plate and has been around for years, locked plating in its present form offers the surgeon another device to treat fractures. The growth of different types of locked plates has been phenomenal but has increased the confusion over the indications for its use. Armed with the knowledge of the biomechanics of locked plating detailed in the previous article, the surgeon answered the question of why use locked plates and now can investigate when to use locked plates. Although many clinical articles support the use of locked plates, a randomized comparison with conventional plates does not exist. Despite this inadequacy in literature, the author believes that many clinical situations exist where patients have benefited from locked plating.

Symptomatic implant removal following dual mini-fragment plating for clavicular shaft fractures.

Objectives: To determine the proportion of patients requiring secondary surgery for symptomatic implant removal after open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures. Design: Retrospective observational study. Setting: Single university Level 1 trauma center. Patients: Eighty-one patients treated with open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures (OTA/AO 15-B1, B2, and B3) with minimum 12-month follow-up (median 477 days; range 371–1549 days). Intervention: Open reduction, internal fixation using dual mini-fragment plating technique for clavicular shaft fractures. Main Outcome Measurements: Incidence of secondary surgery, QuickDASH (Disabilities of the Arm, Shoulder, and Hand) scores. Results: Six of 81 patients (7.4%) underwent secondary surgery for implant removal for any reason. Of these, 3 (3.7%) underwent symptomatic implant (soft-tissue irritation) removal, 2 (2.5%) required implant removal in the setting of infection, and 1 patient (1.2%) required revision open reduction internal fixation for early implant failure. The mean QuickDASH score in this series was 8.44 (±6.94, range 0–77.27). The associated implant cost of the typical construct utilized in this series was

Are cephalomedullary interlocking screws superior to standard interlocking screws in subtrochanteric femoral fractures with an intact lesser trochanter

1511.38. The mean surgical time was 97 minutes (range 71–143 minutes). Conclusions: The utilization of a dual mini-fragment plating technique in the treatment of clavicular shaft fractures results in a low rates of secondary surgery for symptomatic implant removal (3.7%) and similar QuickDASH scores when compared with historical controls treated with 3.5-mm plates placed on the superior clavicle. Potential disadvantages in using this technique include a higher surgical implant cost and length of surgery. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.