Preliminary study on the stabilization of varus proximal femoral osteotomies using pediatric LCP plates in adults undergoing combined correction of proximal femoral and acetabular dysplasia.

PURPOSE: Proximal femoral osteotomy (PFO) with periacetabular osteotomy (PAO) improves femoral head coverage in patients with proximal femoral and acetabular dysplasia. Historically, blade plates used in the PFO cause soft-tissue irritation and often lead to implant removal. Here we present a technique using a lower profile pediatric proximal femoral locking compression plate (LCP) for the PFO in a series of adults. METHODS: The results from 13 hips in 11 patients ≥ 18 years old (age 18-37) with > 10 months of follow-up are presented. RESULTS: All patients had improved radiographic parameters, pain, and total Merle d'Aubigné-Postel scores postoperatively. Eleven hips (85%) had the LCP removed an average of 15.8 ± 8.6 months postoperatively, often due to pain over the greater trochanter. CONCLUSION: The pediatric proximal femoral LCP is effective for PFO in combined PAO PFO procedures but has a high rate of lateral hip discomfort leading to implant removal.

Interaction of preoperative chemoprophylaxis and tranexamic acid use does not affect transfusion in acetabular fracture surgery.

PURPOSE: While the effects of tranexamic acid (TXA) use on transfusion rates after acetabular fracture surgery are unclear, previous evidence suggests that holding deep vein thrombosis (DVT) chemoprophylaxis may improve TXA efficacy. This study examines whether holding DVT chemoprophylaxis in patients receiving TXA affects intraoperative and postoperative transfusion rates in acetabular fracture surgery. METHODS: We reviewed electronic medical records (EMR) of 305 patients who underwent open reduction and internal fixation of acetabular fractures (AO/OTA 62) and stratified patients per the following perioperative treatment: (1) no intraoperative TXA (noTXA), (2) intraoperative TXA and no preoperative DVT prophylaxis (opTXA/noDVTP), or (3) intraoperative TXA and preoperative DVT prophylaxis (opTXA/opDVTP). The primary outcomes were need for intraoperative or postoperative transfusion. Risk factors for each primary outcome were assessed using multivariable regression. RESULTS: Intraoperative or postoperative transfusion rates did not significantly differ between opTXA/opDVTP and opTXA/noDVTP groups (46.2% vs. 36%, p = 0.463; 15.4% vs. 28%, p = 0.181). Median units transfused did not differ between groups (2 ± 1 vs. 2 ± 1, p = 0.515; 2 ± 1 vs. 2 ± 0, p = 0.099). There was no association between preoperative DVT chemoprophylaxis and TXA with intraoperative or postoperative transfusions. EBL, preoperative hematocrit, and IV fluids were associated with intraoperative transfusions; age and Charlson Comorbidity Index (CCI) were associated with postoperative transfusions. CONCLUSION: Our findings suggest holding DVT prophylaxis did not alter the effect of TXA on blood loss or need for transfusion.

Drilling the cement mantle in well-fixed periprosthetic femur fractures is not associated with arthroplasty-related complications.

OBJECTIVE: To determine if screw fixation across a cement mantle is safe and effective during plate fixation of well-fixed periprosthetic femur fractures. DESIGN: Retrospective cohort study. SETTING: Academic Level I Trauma Center. PATIENTS: Twenty-eight patients with AO/OTA 32A[B1] or 32A[C] periprosthetic femur fractures treated with open reduction and internal plate and screw fixation after cemented or uncemented hip arthroplasty. INTERVENTION: Screw placement into the cement mantle during internal fixation. OUTCOME MEASUREMENTS: Primary outcome was revision arthroplasty for aseptic loosening. Secondary outcomes included radiographic evidence of aseptic loosening, infection, nonunion, implant failure, and overall reoperation rate. RESULTS: There were 28 patients who met inclusion criteria. A total of 9 patients had screws placed in the cement mantle while the remaining 19 patients had screws placed around an uncemented stem. At a mean of 3.7-year follow-up, there were no cases of revision arthroplasty or aseptic loosening in either group. There were no significant differences in rates of infection, nonunion, implant failure, or reoperation rate between patients who had screw placement into a cement mantle vs around an uncemented stem. CONCLUSION: Drilling into the cement mantle during fixation of a periprosthetic femur fracture around a well-fixed cemented hip stem appears safe and effective. When possible, surgeons can consider bicortical screws around a cemented stem, given the biomechanical advantages over unicortical screw or cerclage fixation. Larger prospective trials confirming the safety of this technique are warranted prior to routine implementation. LEVEL OF EVIDENCE: III.

Acetabular labral reconstruction with medial meniscal allograft: preliminary results of a new surgical technique.

PURPOSE: Reconstruction of the acetabular labrum during femoroacetabular impingement (FAI) surgery is accepted when the labrum is deficient and irreparable. Here we describe a novel technique using fresh-frozen medial meniscal allograft for labral reconstruction during surgical hip dislocation for correction of pincer FAI due to acetabular overcoverage. METHODS: The results from seven hips (six patients) that underwent this procedure with 1 year minimum follow-up, and radiographs are presented. RESULTS: Six of the seven hips had improvements in pain, hip flexion, hip abduction, and Merle d'Aubigné-Postel scores. Only one patient with pre-existing osteoarthritis underwent reoperation with conversion to total hip arthroplasty. All digastric trochanteric osteotomies healed, and there were no cases of femoral head osteonecrosis or progression of Tönnis grades. CONCLUSIONS: The medial meniscus is a morphologically and clinically suitable option for labral reconstruction and effectively restores the hip fluid seal.

Tranexamic acid does not affect intraoperative blood loss or in-hospital outcomes after acetabular fracture surgery.

PURPOSE: Tranexamic acid (TXA) reduces need for transfusion in total joint arthroplasty, though findings in acetabular surgery are conflicting. We compared outcomes after acetabular fracture surgery with or without perioperative intravenous (IV) TXA administration. METHODS: We performed a retrospective review of 305 patients with acetabular fractures that underwent open reduction and internal fixation (ORIF). Eighty-nine patients received TXA, and 216 did not. The primary outcome was rates of intraoperative and postoperative allogeneic blood transfusion. RESULTS: Baseline demographics and characteristics were similar. Time from injury to surgery and estimated blood loss were comparable. Operative time (p < 0.01) and intraoperative IV fluids (p < 0.01) were greater in the non-TXA group. The proportion of patients who received blood transfusion and mean units transfused intraoperatively and postoperatively did not differ. Mean differences in preoperative and postoperative hemoglobin and hematocrit, hospital length of stay, and perioperative complications also did not differ. In a multivariable regression model, age 60-70 years, Charlson Comorbidity Index, Injury Severity Score, and fracture patterns likely to bleed were independently associated with intraoperative transfusion. Anterior surgical approaches and intraoperative transfusion requirement were independently associated with postoperative transfusion. CONCLUSION: In this study, perioperative IV TXA did not decrease blood loss, need for transfusion, or improve in-hospital outcomes of acetabular fracture surgery. Age 60-70, CCI, ISS, and fracture patterns likely to bleed were independently associated with intraoperative transfusion. Anterior surgical approach and need for intraoperative transfusion were independently associated with postoperative transfusion. Further prospective trials are warranted to confirm these findings.

Hypotensive Anesthesia does not reduce Transfusion Rates during and after Acetabular Fracture Surgery.

BACKGROUND: Acetabular fracture open reduction and internal fixation (ORIF) is generally associated with high intraoperative blood loss. Hypotensive anesthesia has been shown to decrease blood loss and intraoperative transfusion in total joint arthroplasty and posterior spinal fusion. In this study, we assessed the effect of reduction in intraoperative mean arterial pressures (MAPs) during acetabular fracture surgery on intraoperative blood loss and need for transfusion. METHODS: Three hundred and one patients with acetabular fractures who underwent ORIF at an academic Level 1 trauma center were retrospectively reviewed. Patients were separated based on mean intraoperative MAPs (<60 mmHg, 60-70 mmHg, >70 mmHg). Thirteen patients had mean intraoperative MAP <60 mmHg, 95 had MAP 60-70 mmHg, and 193 had MAP >70 mmHg. Rates of intraoperative and postoperative allogeneic blood transfusion were compared. RESULTS: Mean intraoperative MAPs were significantly different between groups (p < 0.0001). Time from injury to surgery, estimated blood loss, operative time and intraoperative IV fluids were comparable. The proportion of patients who received blood transfusion and mean units transfused intraoperatively and postoperatively were similar between groups. Mean differences in preoperative and postoperative hemoglobin and hematocrit were also similar. There was no difference in hospital length of stay or perioperative complications between the groups. Multivariate logistic regression analysis demonstrated that body mass index > 30 (p < 0.05) and anterior surgical approach (p < 0.01) were independently associated with intraoperative transfusion and an anterior surgical approach (p < 0.001) was independently associated with postoperative transfusion. CONCLUSION: Decreased intraoperative MAP during acetabular fracture surgery does not reduce blood loss or need for transfusion. On the other hand, no increased end-organ ischemia was seen with hypotensive anesthesia. LEVEL OF EVIDENCE: Therapeutic Level III.

Management of the posterior wall fracture in associated both column fractures of the acetabulum.

PURPOSE: The primary aim of this study was to compare clinical outcomes in patients with associated both column (ABC) acetabular fractures with fracture of the posterior wall (PW), in which the PW underwent reduction and fragment-specific fixation versus those that were treated with column fixation alone. Secondary aims were to assess PW fracture incidence and morphology, as well as to compare radiographic outcomes including fracture healing and interval displacement of the PW in those that did and did not undergo fragment-specific fixation of the PW. METHODS: This was a retrospective series of ABC acetabular fractures treated at a single Level I trauma center. Separate fractures of the PW were identified, and associated features were assessed. Associated both column fractures that underwent reduction and fragment-specific fixation of the PW where then compared to ABC fractures with PW involvement that underwent column reconstruction alone. Radiographic and clinical outcomes were compared. RESULTS: Fractures of the PW occurred in 55.7% of ABC fractures and were associated with central displacement of the femoral head. The majority of PW fractures were large and involved the acetabular roof. All PW fractures healed without displacement by 3 months, regardless of whether or not reduction and stabilization was performed. Mid-term outcomes at 1-year were similar regardless of whether or not the PW was reduced and stabilized, with regards to Tönnis grade, Merle d'Aubigné-Postel score, and conversion to total hip arthroplasty. CONCLUSION: Reduction and fragment-specific fixation of the PW component of ABC acetabular fractures did not improve outcomes in this small comparative study. Posterior wall fractures associated with ABC patterns are frequently large-sized fragments that involve the acetabular roof and are rendered stable after reconstruction of the columns.

Gluteus Minimus Debridement During Acetabular Fracture Surgery Does Not Prevent Heterotopic Ossification-A Comparative Study.

OBJECTIVES: To compare rates of heterotopic ossification (HO) after acetabular fracture surgery, through a posterior approach, with and without gluteus minimus muscle (GMM) debridement. DESIGN: Retrospective comparative study. SETTING: Single academic Level I trauma center. PATIENTS: Ninety-four patients in the GMM preserved group and 42 patients in the GMM debrided group met inclusion criteria. INTERVENTION: GMM preservation or debridement during acetabular fracture surgery through a single-posterior approach. MAIN OUTCOME MEASUREMENTS: Primary outcomes were incidence and severity of HO. Reoperation for HO excision was assessed. Other risk factors for severe HO (Brooker class III-IV) were secondarily assessed using multivariable logistic regression analyses. Odds ratios (ORs) with 95% confidence intervals were calculated. The significance was set at P-value ≤ 0.05. RESULTS: There was no difference in the incidence or severity of HO between the debrided and preserved groups. Rates of reoperation for HO excision were comparable. American Society of Anesthesiologists physical status class (OR = 3.3), head injury (OR = 4.6), and abdominal injury (OR = 4.5) were associated with severe HO. CONCLUSION: GMM debridement was not associated with a decreased incidence of HO after acetabular fracture surgery. American Society of Anesthesiologists class is a novel risk factor associated with severe HO formation. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Trochanteric osteotomy for acetabular fracture fixation: a case series and literature review.

PURPOSE: This study examined osteotomy union and heterotopic ossification (HO) after performing digastric trochanteric osteotomies during open reduction and internal fixation (ORIF) of acetabular and combined femoral head fractures. Femoral head osteonecrosis and trochanteric screw removal were secondarily assessed. METHODS: Twenty-six patients treated at a Level I trauma center, from years 2003 to 2019, who received a digastric trochanteric osteotomy during acetabular and combined femoral head fracture ORIF through a posterior surgical approach were retrospectively identified. Osteotomies were fixed with two 3.5 mm cortical lag screws. Rates of osteotomy union, HO, femoral head osteonecrosis, and trochanteric screw removal were determined. RESULTS: All osteotomies went onto union without displacement or failure of fixation. Only three (12%) patients developed severe HO (modified-Brooker class III-IV). There were no instances of femoral head osteonecrosis and only one (7%) patient required trochanteric screw removal. CONCLUSIONS: The digastric trochanteric osteotomy heals reliably with low rates of severe HO, femoral head osteonecrosis, and screw removal for soft-tissue irritation. A review of the literature is presented and found comparable findings.

Sequential ilioinguinal or anterior intrapelvic approach with anterior approach to the hip during combined internal fixation and total hip arthroplasty for acetabular fractures.

PURPOSE: This study examined the complications and outcomes of geriatric acetabular fractures treated with open reduction internal fixation (ORIF) and total hip arthroplasty (THA) performed via combined ilioinguinal or anterior intrapelvic (AIP) approach to acetabulum and anterior approach to the hip. METHODS: Eight patients with a fracture of the acetabulum were treated at a Level I trauma center between 2010 and 2019 with combined ORIF/THA using an ilioinguinal or AIP approach for the acetabulum and a separate anterior approach to the hip. Wound dehiscence, peri-incisional skin necrosis, surgical site infection, dislocation, fracture union, acetabular component stability, and heterotopic ossification (HO) were utilized as outcome measures. Merle d'Aubigné-Postel scores were collected for the six patients that had one-year minimum follow-up. RESULTS: The mean patient age was 77 years. Four patients had anterior wall fractures, two had associated both column fractures, and two had anterior column-posterior hemitransverse fractures. All fractures healed with stable fixation of the acetabular component by 6 months. There were no instances of skin necrosis, dislocation, infection, or re-operation. One patient had a superficial wound dehiscence that resolved with local wound care. One patient developed radiographic HO but was clinically asymptomatic. The mean Merle d'Aubigné-Postel score was 15.8 (range = 14-16). CONCLUSIONS: Our small series of geriatric patients with fracture of the acetabulum treated with combined ORIF/THA, via the ilioinguinal or AIP approach with a separate anterior approach to the hip, demonstrates satisfactory outcomes with low complications after one-year of follow-up. Further research of these challenging injuries with more patients is warranted in order to determine the subset of fracture types best treated with this method and THA survivorship.

Metaphyseal callus formation in pilon fractures is associated with loss of alignment: Is stiffer better?

OBJECTIVE: To assess the relationship between metaphyseal callus formation and preservation of distal tibial alignment in pilon fractures treated with internal plate fixation. DESIGN: Retrospective Review SETTING: Academic Level I Trauma Center PATIENTS: Forty-two patients with AO/OTA type C2 or C3 pilon fractures treated with plate fixation. INTERVENTION: Internal fixation with anterolateral plating, medial plating, or both. Modified Radiographic Union Score in Tibial fracture (mRUST) scores were determined from six-month radiographs. MAIN OUTCOME MEASUREMENTS: Change in lateral and anterior distal tibial angles (LDTA and ADTA) at six months post-operatively. RESULTS: High callus formation (mRUST ≥ 11 at six months) was associated with a greater loss of coronal reduction as measured by LDTA compared to low callus formation (mRUST < 11): 3.8 vs 2.1° (p = .019), with no difference in ADTA change between groups. In a multivariable logistic regression controlling for age, smoking, obesity, and open fracture, higher mRUST scores were a predictor of coronal reduction loss of five or more degrees (OR 1.71, p=.039). Dual column plating did not independently predict maintenance of alignment. CONCLUSIONS: Recent literature has popularized dual column fixation for pilon fractures, but it remains unknown whether increased metaphyseal stiffness enhances or impairs healing. In this series, decreased metaphyseal callus formation was associated with maintained coronal alignment, suggesting that a stiffer mechanical environment may be preferable to prevent short term reduction loss in these complex injuries. LEVEL OF EVIDENCE: III.

An anatomic classification for heterotopic ossification about the hip.

STUDY DESIGN: Retrospective cohort. SUMMARY OF BACKGROUND DATA: Heterotopic ossification (HO) about the hip is a debilitating condition that can occur after fixation for acetabular fractures, total hip replacement, or polytrauma with closed head injuries. No classification exists that informs surgical treatment. PURPOSE: To establish a classification system for HO about the hip by reviewing a consecutive series of HO at a single institution. It was hypothesized that HO about the hip could be grouped into a novel classification scheme based upon the location and involved structures of the hip. METHODS: Retrospective chart review of single center's case log for HO excision from 2004 to 2018 was performed. Inclusion criteria included all patients undergoing excision of heterotopic bone excision about the hip. Demographic data, pre and post hip range of motion, surgical approach for each surgery, index surgery date and interval to excision are reported as well as presence and location of HO and Brooker classification. RESULTS: A total of 36 patients (21 men and 15 women) and 40 hips were identified meeting inclusion criteria. The mean age at the time of the index surgery was 47 (range, 16-77 years). Traumatic injury with fracture (35%) included 9 acetabular fractures (22%), 2 long bone fractures (5%) treated with intramedullary devices, one displaced femoral neck fracture (2%), and one pelvic ring injury (2%). Total hip arthroplasty accounted for 32% of patients. Brooker classification was type 4 (35%), 3 (25%), 2 (23%), 1(17%) which translated to 55% anterior, 48% posterior, 3% medial with respect to location. Average improvement in hip flexion and abduction was 22 and 8°, respectively. CONCLUSION: This study identified discrete locations for heterotopic ossification following hip or acetabulum surgery. Both posterior and anterior structures are implicated in the formation of HO, and this investigation presents a novel classification to guide surgical approach for HO excision based upon location.

Cytokines as a predictor of clinical response following hip arthroscopy: minimum 2-year follow-up.

Hip arthroscopy in patients with osteoarthritis has been shown to have suboptimal outcomes. Elevated cytokine concentrations in hip synovial fluid have previously been shown to be associated with cartilage pathology. The purpose of this study was to determine whether a relationship exists between hip synovial fluid cytokine concentration and clinical outcomes at a minimum of 2 years following hip arthroscopy. Seventeen patients without radiographic evidence of osteoarthritis had synovial fluid aspirated at time of portal establishment during hip arthroscopy. Analytes included fibronectin-aggrecan complex as well as a multiplex cytokine array. Patients completed the modified Harris Hip Score, Western Ontario and McMaster Universities Arthritis Index and the International Hip Outcomes Tool pre-operatively and at a minimum of 2 years following surgery. Pre and post-operative scores were compared with a paired t-test, and the association between cytokine values and clinical outcome scores was performed with Pearson's correlation coefficient with an alpha value of 0.05 set as significant. Sixteen of seventeen patients completed 2-year follow-up questionnaires (94%). There was a significant increase in pre-operative to post-operative score for each clinical outcome measure. No statistically significant correlation was seen between any of the intra-operative cytokine values and either the 2-year follow-up scores or the change from pre-operative to final follow-up outcome values. No statistically significant associations were seen between hip synovial fluid cytokine concentrations and 2-year follow-up clinical outcome assessment scores for those undergoing hip arthroscopy.

The prevalence of sacroiliac joint degeneration in asymptomatic adults.

BACKGROUND: Degenerative changes of the sacroiliac joint have been implicated as a cause of lower back pain in adults. The purpose of this study was to determine the prevalence of sacroiliac joint degeneration in asymptomatic patients. METHODS: Five hundred consecutive pelvic computed tomography (CT) scans, made at a tertiary-care medical center, of patients with no history of pain in the lower back or pelvic girdle were retrospectively reviewed and analyzed for degenerative changes of the sacroiliac joint. After exclusion criteria were applied, 373 CT scans (746 sacroiliac joints) were evaluated for degenerative changes. Regression analysis was used to determine the association between age and the degree of sacroiliac joint degeneration. RESULTS: The prevalence of sacroiliac joint degeneration was 65.1%, with substantial degeneration occurring in 30.5% of asymptomatic subjects. The prevalence steadily increased with age, with 91% of subjects in the ninth decade of life displaying degenerative changes. CONCLUSIONS: Radiographic evidence of sacroiliac joint degeneration is highly prevalent in the asymptomatic population and is associated with age. Caution must be exercised when attributing lower back or pelvic girdle pain to sacroiliac joint degeneration seen on imaging. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Surgical treatment of flail chest and rib fractures.

Despite significant advances in critical care management, flail chest remains a clinically significant finding, with a mortality rate of up to 33%. Nonsurgical management is associated with prolonged ventilator support, pneumonia, respiratory difficulties, and lengthy stays in the intensive care unit, as well as chronic pain from nonunion and malunion of the bony thorax. Treatment with aggressive pulmonary toilet, ventilator support, and different modalities of pain control remains the benchmark of care. However, several recent randomized controlled studies of surgical intervention of flail chest have demonstrated an improvement in the number of ventilator days, intensive care unit and hospital stays, incidence of pneumonia, and respiratory function and hospital costs, as well as faster return to work. The success of these surgical constructs compared with those of historical attempts at open fixation is largely the result of modern plating technology and improvement in surgical approaches. Clinical evidence continues to grow regarding proper indications and techniques for surgical stabilization of flail chest.

Fibronectin-aggrecan complex as a marker for cartilage degradation in non-arthritic hips.

PURPOSE: To report hip synovial fluid cytokine concentrations in hips with and without radiographic arthritis. METHODS: Patients with no arthritis (Tonnis grade 0) and patients with Tonnis grade 2 or greater hip osteoarthritis (OA) were identified from patients undergoing either hip arthroscopy or arthroplasty. Synovial fluid was collected at the time of portal establishment for those undergoing hip arthroscopy and prior to arthrotomy for the arthroplasty group. Analytes included fibronectin-aggrecan complex (FAC) as well as a standard 12 cytokine array. Variables recorded were Tonnis grade, centre-edge angle of Wiberg, as well as labrum and cartilage pathology for the hip arthroscopy cohort. A priori power analysis was conducted, and a Mann-Whitney U test and regression analyses were used with an alpha value of 0.05 set as significant. RESULTS: Thirty-four patients were included (17 arthroplasty, 17 arthroscopy). FAC was the only analyte to show a significant difference between those with and without OA (p < 0.001). FAC had significantly higher concentration in those without radiographic evidence of OA undergoing microfracture versus those not receiving microfracture (p < 0.05). CONCLUSION: There was a significantly higher FAC concentration in patients without radiographic OA. Additionally, those undergoing microfracture had increased levels of FAC. As FAC is a cartilage breakdown product, no significant amounts may be present in those with OA. In contrast, those undergoing microfracture have focal area(s) of cartilage breakdown. These data suggest that FAC may be useful in predicting cartilage pathology in those patients with hip pain but without radiographic evidence of arthritis.

The posterior approach to pelvic ring injuries: A technique for minimizing soft tissue complications.

Surgical techniques and fixation strategies for the treatment of unstable posterior pelvic ring injuries continue to evolve. The safety of the posterior surgical approach in particular has been questioned due to historically high rates of wound related complications. More contemporary studies have shown lower infection rates, however concern still persists. These concerns for infection and wound necrosis have led, in part, to increased interest in closed reduction and percutaneous fixation for treatment of these injuries but an open posterior approach remains the optimal strategy in some injury patterns. We describe herein a modified posterior approach to the pelvis designed to minimize wound related complications and present our clinical results demonstrating wound complication rates consistent with contemporary publications.

Risk factors for development of heterotopic ossification of the elbow after fracture fixation.

BACKGROUND: Postoperative heterotopic ossification (HO) about the elbow may occur after surgical fixation of fractures and can contribute to dysfunction. Factors associated with HO formation after surgical fixation of elbow trauma are not well understood. METHODS: All patients who underwent surgery for elbow trauma at our institution from October 2001 through August 2010 were retrospectively reviewed. Patients with prior injury or deformity to the involved elbow were excluded. Demographic data; fracture type; surgical treatment; and presence, location, and size of HO were recorded. The Fisher exact test, χ(2) test, and multivariate logistic regression were used with an α value of .05 used for significance. RESULTS: A total of 159 patients were identified, with 89 (37 men and 52 women) meeting inclusion and exclusion criteria. The mean age was 54.4 years (range, 18-90 years), and the mean follow-up time was 180 days. Age, male gender, lateral collateral ligament repair, and dual-incision approach were not associated with increased ectopic bone formation. Distal humeral fractures were a significant predictor of heterotopic bone. In patients in whom HO ultimately developed, it was visible on radiographs obtained 2 weeks postoperatively in 86% of cases. CONCLUSION: This investigation found predictors for the development of HO after surgical fixation of intra-articular elbow fractures. Furthermore, HO went on to develop at the time of final follow-up in only 14% of patients without HO on radiographs obtained 2 weeks postoperatively. This may suggest that absence of HO on radiographs obtained 2 weeks postoperatively may predict a more favorable outcome.