Any Cortical Bridging Predicts Healing of Supracondylar Femur Fractures After Treatment With Locked Plating

Bridge Plate Fixation of Distal Femur Fractures: Defining Deficient Radiographic Callus Formation and Its Associations

OBJECTIVE

To determine whether deficient early callus formation can be defined objectively based on the association with an eventual nonunion and specific patient, injury, and treatment factors.

METHODS

Final healing outcomes were documented for 160 distal femur fractures treated with locked bridge plate fixation. Radiographic callus was measured on postoperative radiographs until union or nonunion had been declared by the treating surgeon. Deficient callus was defined at 6 and 12 weeks based on associations with eventual nonunion through receiver-operator characteristic analysis. A previously described computational model estimated fracture site motion based on the construct used. Univariable and multivariable analyses then examined the association of patient, injury, and treatment factors with deficient callus formation.

RESULTS

There were 26 nonunions. The medial callus area at 6 weeks <24.8 mm 2 was associated with nonunion (12 of 39, 30.8%) versus (12 of 109, 11.0%), P = 0.010. This association strengthened at 12 weeks with medial callus area <44.2 mm 2 more closely associated with nonunion (13 of 28, 46.4%) versus (11 of 120, 9.2%), P <0.001. Multivariable logistic regression analysis found limited initial longitudinal motion (OR 2.713 (1.12-6.60), P = 0.028)) and Charlson Comorbidity Index (1.362 (1.11-1.67), P = 0.003) were independently associated with deficient callus at 12 weeks. Open fracture, mechanism of injury, smoking, diabetes, plate material, bridge span, and shear were not significantly associated with deficient callus.

CONCLUSION

Deficient callus at 6 and 12 weeks is associated with eventual nonunion, and such assessments may aid future research into distal femur fracture healing. Deficient callus formation was independently associated with limited initial longitudinal fracture site motion derived through computational modeling of the surgical construct but not more routinely discussed parameters such as plate material and bridge span. Given this, improved methods of in vivo assessment of fracture site motion are necessary to further our ability to optimize the mechanical environment for healing.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Clinical Assessments of Fracture Healing and Basic Science Correlates: Is There Room for Convergence?

PURPOSE OF REVIEW

The purpose of this review is to summarize the clinical and basic science methods used to assess fracture healing and propose a framework to improve the translational possibilities.

RECENT FINDINGS

Mainstays of fracture healing assessment include clinical examination, various imaging modalities, and assessment of function. Pre-clinical studies have yielded insight into biomechanical progression as well as the genetic, molecular, and cellular processes of fracture healing. Efforts are emerging to identify early markers to predict impaired healing and possibly early intervention to alter these processes. Despite of the differences in clinical and preclinical research, opportunities exist to unify and improve the translational efforts between these arenas to develop and optimize our ability to assess and predict fracture healing, thereby improving the clinical care of these patients.

Cortical bridging a union predictor: A prospective study after intramedullary nailing of the femoral shaft fractures

Early prediction of the union helps for timely intervention, reduction of hospitalization, treatment costs, and disability in cases of nonunion. With this in mind, we tried to find how long any cortical bridging predicts the union in femoral shaft fractures. A prospective study of 113 femoral shaft fractures treated with reamed, locked intramedullary nailing was performed. Radiographs were taken during months 2 to 4, 6, 9, and one-year follow-up. The cortical bridging (presence and number) was assessed by anterior-posterior and lateral views. The ROC curve provides the prediction of the union. The overall nonunion rate was 10.6% (12 of 113 fractures). Age and diabetes mellitus were statistically significant with nonunion (p value < 0.001). The final analysis demonstrated that any cortical bridging at four months postoperatively was the most accurate and earlier indicator (105 of 113, 92.9% accuracy), while it was 84.9% at six months in bicortical and 80.5% accuracy at nine months in tricortical bridging. Low-cost and simple radiographic imaging presents cortical bridging in any form 4 months after surgery that precisely predicts a union in femoral shaft fractures.

ON Path: outpatient nonunion pathway for lower-extremity nonunions

Objectives

The purpose of this study was to assess the safety and efficacy of outpatient and short-stay surgical nonunion treatment by incorporating minimally invasive surgical techniques, multimodal pain control, and a modernized postoperative protocol.

Design

Retrospective case series.

Setting

Tertiary referral hospital and hospital outpatient department.

Patients

All consecutive nonunion surgeries performed by 1 surgeon between 2014 and 2019 were identified. Outpatient and short-stay surgeries for patients with nonunion of the tibia and femur were eligible (n = 50).

Intervention

Outpatient and short-stay surgical nonunion treatment by incorporating minimally invasive surgical techniques, multimodal pain control, and a modernized postoperative protocol.

Main Outcome Measurements

Length of stay, postoperative emergency department visits, all complications, reoperations, and time to union.

Results

Fifty patients were eligible, with 32 male patients (64%) and an average age of 46.5 years. The patient cohort consisted of 28 femur (56%) and 22 tibia (44%) nonunions. The average length of stay was 0.36 days. Seven patients (14%) required reoperation, 6 patients because of deep infection and 1 patient because of painful implant removal. Four patients (8%) presented to the emergency department within 1 week of surgery. One patient requiring amputation and patients lost to follow-up were excluded from the union rate calculation. For the remaining patients (46/50), 100% (46/46) united their nonunion. The average time to radiographic union was 7.82 months.

Conclusions

An outpatient pathway is safe and effective for medically appropriate patients undergoing nonunion surgery. Outpatient nonunion surgery is a reasonable alternative that achieves similar outcomes compared with inpatient nonunion studies in the published literature.

Level of Evidence

IV.

Radiographic Scoring of Humeral Shaft Fractures Helps Identify Patients at Risk of Surgery for Delayed Union

OBJECTIVES

Assessing external validity and clinical relevance of modified radiographic union score (mRUS) to predict delayed union in closed humeral shaft fractures initially treated with conservative management.

DESIGN

Retrospective cohort.

SETTING

Single urban academic level 1 trauma center.

PATIENTS

Patients undergoing initial nonoperative treatment of a humeral shaft fracture with a minimum of 3 months follow-up and at least one set of follow-up orthogonal x-rays within 12-weeks of injury.

MAIN OUTCOME MEASUREMENTS

Interobserver and intraobserver reliability of the (mRUS) system for humeral shaft fractures, and establishing an mRUS threshold at 6 and 12 weeks postinjury to predict surgery for delayed union.

RESULTS

mRUS demonstrated substantial interobserver agreement on all assessments. Intraobserver agreement was nearly perfect for all reviewers on repeat assessment. mRUS of ≤7 at 6 ± 1 weeks follow-up was associated with surgery for delayed union with an odds ratio of 4.88 (95% CI, 2.52-9.44, P < 0.01), sensitivity of 0.286, and specificity of 0.924. At 12 ± 1 weeks follow-up, the same threshold demonstrated a stronger association with an odds ratio of 14.7 (95% CI, 4.9-44.1, P < 0.01), sensitivity of 0.225, and specificity of 0.981.

CONCLUSIONS

The mRUS for humeral shaft fractures is reliable and reproducible providing an objective way to track subtle changes in radiographs over time. An mRUS of ≤7 at 6 or 12 weeks postinjury is highly specific for delayed union. This can be helpful when counseling patients about the risk of nonunion and potential early surgical intervention.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Results of Low Distal Femur Periprosthetic Fractures

OBJECTIVES

To compare retrograde intramedullary nail (RIMN) and open reduction internal fixation (ORIF) in very distal periprosthetic distal femur fractures (PDFFs) to determine whether RIMN is an acceptable option for these fractures that are often considered too distal for IMN due to limited bone stock.

DESIGN

Retrospective comparative series.

SETTING

Level 1 trauma center.

PATIENTS

Patients were treated with fracture fixation for a very distal PDFF, defined as the fracture extending to the anterior flange of the implant or distal. Fifty-six patients met inclusion criteria, with 8 excluded for less than 12 months of follow-up.

INTERVENTION

The intervention involved fracture fixation with RIMN or ORIF.

MAIN OUTCOME MEASUREMENTS

The primary outcome was unplanned return to surgery. Secondary outcomes included fracture union, radiographic alignment, visual analog score, and Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference.

RESULTS

The mean follow-up period was 27 months. Twelve patients were treated with ORIF and 36 with RIMN. Twenty-one fractures were at the flange, and 27 extended distal to the flange. There were no differences between fixation methods for reoperation, deep infection, nonunion, malunion, visual analog score pain score, and PROMIS Pain Interference score. The mean PROMIS PF score was higher in the RIMN group compared with that in the ORIF group. There were 5 reoperations in the RIMN group (14%) and 3 in the ORIF group (25%).

CONCLUSIONS

This is the largest series, to the best of our knowledge, of a subset of very distal PDFFs. The results suggest that RIMN may be an acceptable treatment option for these very difficult fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

3D ultrasound reconstruction of sonographic callus : a novel imaging modality for early evaluation of fracture healing

AIMS

The aim of this study was to establish a reliable method for producing 3D reconstruction of sonographic callus.

METHODS

A cohort of ten closed tibial shaft fractures managed with intramedullary nailing underwent ultrasound scanning at two, six, and 12 weeks post-surgery. Ultrasound capture was performed using infrared tracking technology to map each image to a 3D lattice. Using echo intensity, semi-automated mapping was performed to produce an anatomical 3D representation of the fracture site. Two reviewers independently performed 3D reconstructions and kappa coefficient was used to determine agreement. A further validation study was undertaken with ten reviewers to estimate the clinical application of this imaging technique using the intraclass correlation coefficient (ICC).

RESULTS

Nine of the ten patients achieved union at six months. At six weeks, seven patients had bridging callus of ≥ one cortex on the 3D reconstruction and when present all achieved union. Compared to six-week radiographs, no bridging callus was present in any patient. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8% sensitive and 100% specific to predict union). At 12 weeks, nine patients had bridging callus at ≥ one cortex on 3D reconstruction (100%-sensitive and 100%-specific to predict union). Presence of sonographic bridging callus on 3D reconstruction demonstrated excellent reviewer agreement on ICC at 0.87 (95% confidence interval 0.74 to 0.96).

CONCLUSION

3D fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to enhance the usability and accuracy of identification of early fracture healing. Cite this article: Bone Joint Res 2021;10(12):759-766.

Predicting fracture healing with blood biomarkers: the potential to assess patient risk of fracture nonunion

Fracture non-union is a significant orthopaedic problem affecting a substantial number of patients yearly. Treatment of nonunions is devastating to patients and costly to the healthcare system. Unfortunately, the diagnosis of non-union is typically made in a reactionary fashion by an orthopaedic surgeon based on clinical assessment and radiographic features several months into treatment. For this reason, investigators have been trying to develop prediction algorithms; however, these have relied on population-based approaches and lack the predictive capability necessary to make individual treatment decisions. There is also a growing body of literature focussed on identifying blood biomarkers that are associated with non-union. This review describes the research that has been done in this area. Further studies of patient-centered, precision medicine approaches will likely improve fracture non-union diagnostic/prognostic capabilities.

Monitoring of fracture healing. Update on current and future imaging modalities to predict union

Fracture nonunion causes considerable patient morbidity and an associated burden to society. Traditional reliance on radiographs to monitor union has limitations as bridging callus of long bone fractures can take three or more months to occur. Computed Tomographic (CT) scanning is becoming increasingly popular and can evaluate bridging callus in the late stages of healing to confirm union. The use of dynamic contrast enhanced Magnetic Resonance Imaging (MRI) and advances in nuclear imaging may yield benefits in the assessment of the infected nonunion. Emerging evidence supports the use of ultrasound to detect bridging callus prior to radiographic confirmation and it may be of use to predict patients at high risk of nonunion. This paper is part of a Supplement supported by The Osteosynthesis and Trauma Care Foundation (OTCF).

The accuracy of computed tomography for clavicle non-union evaluation

BACKGROUND

The primary aim of this study is to determine the accuracy of CT scanning when evaluating non-union of the clavicle.

METHODS

A retrospective review was performed of all CT scans undertaken for suspected nonunion of midshaft clavicle fractures over a 10-year period. The influence of scan timing, callus and patient characteristics was evaluated.

RESULTS

One hundred eighty-four CT scans were analysed. No patient was incorrectly diagnosed with union (n = 85). Ninety-nine scans were reported as non-union with inadequate bridging callus, 19 of which were united at operation or on repeat CT imaging and represented delayed unions. Atrophic callus was found in 57 patients and all of which had a confirmed non-union (positive predictive value 100%). A hypertrophic callus was found in 42 patients, all of the delayed unions were found in this group (positive predictive value for non-union 55%, p < 0.001). CT compared to radiographs showed greater inter-observer agreement for union (weighted kappa 0.75 vs. 0.50 respectively). Overall, CT is 100% sensitive and 81.7% specific for non-union diagnosis.

DISCUSSION

CT has excellent accuracy to determine clavicle union but approximately one in five suspected non-unions went onto unite. Hypertrophic callus finding resulted in a delayed union in approximately half of the cases in our study.

Sonographic bridging callus at six weeks following displaced midshaft clavicle fracture can accurately predict healing

AIMS

To evaluate if union of clavicle fractures can be predicted at six weeks post-injury by the presence of bridging callus on ultrasound.

METHODS

Adult patients managed nonoperatively with a displaced mid-shaft clavicle were recruited prospectively. Ultrasound evaluation of the fracture was undertaken to determine if sonographic bridging callus was present. Clinical risk factors at six weeks were used to stratify patients at high risk of nonunion with a combination of Quick Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) ≥ 40, fracture movement on examination, or absence of callus on radiograph.

RESULTS

A total of 112 patients completed follow-up at six months with a nonunion incidence of 16.7% (n = 18/112). Sonographic bridging callus was detected in 62.5% (n = 70/112) of the cohort at six weeks post-injury. If present, union occurred in 98.6% of the fractures (n = 69/70). If absent, nonunion developed in 40.5% of cases (n = 17/42). The sensitivity to predict union with sonographic bridging callus at six weeks was 73.4% and the specificity was 94.4%. Regression analysis found that failure to detect sonographic bridging callus at six weeks was associated with older age, female sex, simple fracture pattern, smoking, and greater fracture displacement (Nagelkerke R2 = 0.48). Of the cohort, 30.4% (n = 34/112) had absent sonographic bridging callus in addition to one or more of the clinical risk factors at six weeks that predispose to nonunion. If one was present the nonunion rate was 35%, 60% with two, and 100% when combined with all three.

CONCLUSION

Ultrasound combined with clinical risk factors can accurately predict fracture healing at six weeks following a displaced midshaft clavicle fracture. Cite this article: Bone Joint Res 2021;10(2):113-121.

Radiographic, Bone Densitometry and Clinic Outcomes Assessments in Femoral Shaft Fractures Fixed by Plating or Locking Retrograde Nail

Introduction:

Distal femoral shaft fractures are characterized by increasing incidence and complexity and are still considered a challenging problem (high morbidity and mortality). No consensus on best surgical option has been achieved.

Aim:

This study aims is to investigate radiographic, mineral bone densitometry and clinical outcomes of locking retrograde intramedullary (LRN) nailing and anatomical locking plate to surgically treat distal femoral shaft fractures in young adults based on the hypothesis that there is no statistical difference among the two surgical options in terms of results (radiographic, bone densitometry and outcomes assessment).

Methods:

Retrospective study: 30 patients divided into 2 groups (Group 1 LRN, Group 2 Nailing). Average age was 42.67±18.32 for Group 1 and 42.84 ±18.32 for Group 2 (range of age 18-65 for both groups). Gender Ratio (male: female) was 2.75 (11:4) for both Group 1 and 2. AO Classification, NUSS and RUSH score, VAS, Dexa scans, plain radiographs were used. Evaluation endpoint: 12 months after surgery (mean follow up 16.24).

Results:

No statistical difference in terms of surgery time, transfusions, wound healing. Similar results with regard to average time of bone healing, RUSH scores, VAS, regression between RUSH and VAS, average correlation clinical-radiographic results and patients outcomes. Only one patient of each group had reduction of mineral bone densitometry values.

Conclusion:

No statistical difference about the use of LNR or Nailing for treatment of distal femur shaft fractures in terms of radiographic, bone densitometry and outcomes has been found accordingly to our results. Good subjective and objective results are provided by both techniques. The choice among the two techniques must be based on surgeons’ experience, indications and subjective patients’ aspects. The absence of relevant similar data in the published literature does not allow definitive validation (or rejection) of our hypothesis. A more powered study with bigger cohort is needed for definitive validation.

Medial Open-wedge Osteotomy with Double-plate Fixation for Varus Malunion of the Distal Femur

Objective

To present our clinical experience of treating varus malunion of the distal femur through a medial open‐wedge osteotomy with double‐plate fixation.

Methods

A prospective cohort study was performed. From January 2005 to February 2015, 15 consecutive patients with varus malunion following distal femur fractures were surgically treated at a single level I trauma center. The coronal and sagittal deformity were corrected by a medial open‐wedge osteotomy of the distal femur. A medial buttress plate was used to maintain the realignment. A lateral locking plate was additionally used as a protection plate. The mean age of patients at the time of the surgery was 35.5 years (range, 22–58 years). The radiographical evaluation included the mechanical femorotibial angle, the mechanical lateral distal femoral angle, the anatomic posterior distal femoral angle, and the leg length discrepancy. Clinical outcome evaluation consisted of the range of motion (ROM) and Hospital for Special Surgery (HSS) score.

Results

Mean follow‐up was 7.4 years (range, 4–11.5 years). Varus and flexion malalignment and limb discrepancy were adequately corrected in all patients. The mechanical femorotibial angle, the mechanical lateral distal femoral angle, and the anatomic posterior distal femoral angle were restored from 17.5° (range, 13°–25°) to 2.3° (range, − 2°–7°), 102.3° (range, 95°–112°) to 85.2° (range, 81°–92°), and 77.1° (range, 65°–87°) to 82.7° (range, 76°–88°), respectively. The leg length discrepancy was diminished from 3.4 cm (range, 2.4–4.5 cm) to 0.8 cm (range, 0–1.7 cm). The average bone healing time was 4.1 months (range, 2.5–6 months). The average ROM of the affected knees at 24‐month follow‐up was 3.4°–112.55°. The score of HSS at 4‐years follow‐up was 76.1 (range, 64–88). No internal fixation failure or secondary operation was noted until the last follow‐up.

Conclusion

Medial open‐wedge osteotomy can adequately correct the posttraumatic varus malunion of the distal femur. With fixation of the double plate, non‐displaced bone healing and good functional outcome are expected.

Far Cortical Locking Fixation of Distal Femur Fractures is Dominated by Shear at Clinically Relevant Bridge Spans

OBJECTIVES

Far cortical locking (FCL) constructs have been shown to increase axial interfragmentary displacement while limiting shear and have been specifically recommended in the treatment of distal femur fractures. However, there is no available data regarding their mechanical behavior within the range of bridge spans typically used for comminuted distal femur fractures. This biomechanical study of distal femur locked plate fixation assessed 4 methods of diaphyseal fixation for associated axial and shear displacement at bridge spans typically used in clinical practice.

METHODS

Distal femur locking plates were used to bridge simulated fractures in femur surrogates with 4 different methods of diaphyseal fixation (bicortical locking, bicortical nonlocking, near cortical locking, and FCL). Axial and shear displacement were assessed at 5 different bridge spans for each fixation method.

RESULTS

Diaphyseal fixation type was associated with the amount of shear (P = 0.04), but not the amount of axial displacement (P = 0.39). Specifically, FCL constructs demonstrated greater shear than bicortical locking (median 4.57 vs. 2.94 mm, P = 0.02) and bicortical nonlocking (median 4.57 vs. 3.41 mm, P = 0.02) constructs.

CONCLUSIONS

Unexpectedly, FCL constructs demonstrated greater shear than bicortical locking and nonlocking constructs and similar axial displacement for all fixation methods. Bridge span had a dominant effect on displacement that interacted negatively with more flexible FCL diaphyseal fixation. Potentially interactive construct features are best studied in concert. Given the complexity of these relationships, computational modeling will likely play an integral role in future mechanotransduction research.

Secondary Union of a Critical Segmental Femoral Defect: A Case Report

CASE

We report the case of a 41-year-old man who sustained an open femoral shaft fracture with 10 cm of segmental bone loss in a motorcycle collision. He underwent serial irrigation and debridement procedures and intramedullary nailing of the fracture. He was lost to follow-up, but presented 9 months after the injury with abundant callus formation; at 11 months, the simple hypertrophic nonunion was treated with exchange nailing.

CONCLUSION

Although unusual, secondary union of segmental femoral defects may occur. The mechanism by which this occurs is poorly understood, but is likely related to the biology of the fracture site, the effects of reaming, and the mechanics of the fixation.

Long Bone Union Accurately Predicted by Cortical Bridging within 4 Months

Background:

Previous retrospective research found that the presence or absence of bridging callus within 4 months postoperatively discriminated accurately between eventual union and nonunion of fractures of the tibial shaft. However, there remains no consensus regarding early prognostication of long bone nonunion. We prospectively assessed the accuracy and reliability of the presence of any bridging callus within 4 months in a cohort that was expanded to include both tibial and femoral shaft fractures.

Methods:

We identified 194 consecutive fractures of the shaft of the tibia (OTA/AO type 42-A, B, or C) and femur (OTA/AO type 32-A, B, or C) that were treated with intramedullary nailing. Exclusions for inadequate follow-up (55), extended delay prior to nailing (10), and skeletal immaturity (3) resulted in a study population of 126 fractures (56 tibiae and 70 femora) in 115 patients. Digital radiographs made between 3 and 4 months postoperatively were independently assessed by 3 orthopaedic traumatologists. The accuracy of assessment of the presence of any bridging callus, bicortical bridging, and tricortical bridging to predict union or nonunion was assessed with chi-square analysis and by interobserver reliability (kappa statistic).

Results:

The nonunion rate was 4% (5 of 126 fractures). The presence of any bridging callus by 4 months accurately predicted union (121 of 122 fractures) and its absence predicted nonunion (4 of 4 fractures). There was 1 incorrect prediction of union for a fracture that failed to unite (p < 0.001). Bicortical or greater bridging predicted union when present (116 of 116 fractures) and nonunion when absent (5 of 10 fractures), incorrectly predicting that 5 healing fractures would go on to nonunion (p < 0.001). Tricortical or greater bridging predicted union when present (103 of 103 fractures) and nonunion when absent (5 of 23 fractures), incorrectly predicting that 18 healing fractures would go on to nonunion (p < 0.001). Interobserver reliability was calculated for any bridging (kappa value, 0.91), bicortical bridging (kappa value, 0.79), tricortical bridging (kappa value, 0.71), and the exact number of cortices bridged (kappa value, 0.67).

Conclusions:

The presence of any bridging callus within 4 months accurately predicts the final healing outcome for tibial and femoral shaft fractures treated with intramedullary nailing. This criterion is simple and reliable, and only standard radiographs are needed to make the determination. Basing the prognosis on the bridging of additional cortices risks overestimation of the nonunion rate and is associated with relatively poor reliability.