Segmental defect healing in the presence or absence of recombinant human BMP2: Novel insights from a rat model

This study defined and compared the course of native, impaired and growth factor-stimulated bone regeneration in a rat femoral defect model. A mid-diaphyseal defect with rigid internal fixation was surgically created in the right femur of male Fischer rats and serially analyzed over 36 weeks. Native bone regeneration was modeled using a sub-critical, 1 mm size defect, which healed uneventfully. Critical size defects of 5 mm were used to analyze impaired bone regeneration. In a third group, the 5 mm defects were filled with 11 µg of recombinant human bone morphogenetic protein 2 (rhBMP2) impregnated onto an absorbable collagen sponge, modeling its clinical use. Native bone regeneration was characterized by endochondral ossification with progressive remodeling to ultimately resemble intact femora. An endochondral response was also observed under conditions of impaired bone regeneration, but by week 8 medullary capping occurred with fibrofatty consolidation of the tissue within the defect, resembling an atrophic non-union. rhBMP2 treatment was associated with prolonged inflammatory cytokine expression and rapid intramembranous bone formation occurring with reduced expression of cartilage-associated collagens. Between weeks 4 and 36, rhBMP2-treated bones demonstrated decreased trabecular number and increased trabecular separation, which resulted in inferior mechanical properties compared with bones that healed naturally. Clinical Significance: Recombinant human bone morphogenetic protein 2 (rhBMP2) is used clinically to promote healing of long bones. Our data suggest that it drives intramembraneous ossification producing an inferior regenerate that deteriorates with time. Clinical outcomes would be improved by technologies favoring endochondral regenerative ossification.

The Fate of Delayed Unions After Isolated Ankle Fusion

BACKGROUND

Nonunion remains the most common major complication of ankle arthrodesis. Although previous studies have reported delayed union or nonunion rates, few have elaborated on the clinical course of patients experiencing delayed union. In this retrospective cohort study, we sought to understand the trajectory of patients with delayed union by determining the rate of clinical success and failure and whether the extent of fusion on computed tomography scan (CT) was associated with outcomes.

METHODS

Delayed union was defined as incomplete (<75%) fusion on CT between 2 and 6 months postoperatively. Thirty-six patients met the inclusion criterion: isolated tibiotalar arthrodesis with delayed union. Patient-reported outcomes were obtained including patient satisfaction with their fusion. Success was defined as patients who were not revised and reported satisfaction. Failure was defined as patients who required revision or reported being not satisfied. Fusion was assessed by measuring the percentage of osseous bridging across the joint on CT. The extent of fusion was categorized as absent (0%-24%), minimal (25%-49%), or moderate (50%-74%).

RESULTS

We determined the clinical outcome of 28 (78%) patients with mean follow-up of 5.6 years (range, 1.3-10.2). The majority (71%) of patients failed. On average, CT scans were obtained 4 months after attempted ankle fusion. Patients with minimal or moderate fusion were more likely to succeed clinically than those with "absent" fusion (P = .040). Of those with absent fusion, 11 of 12 (92%) failed. In patients with minimal or moderate fusion, 9 of 16 (56%) failed.

CONCLUSION

We found that 71% of patients with a delayed union at roughly 4 months after ankle fusion required revision or were not satisfied. Patients with less than 25% fusion on CT had an even lower rate of clinical success. These findings may help surgeons in counseling and managing patients experiencing a delayed union after ankle fusion.

LEVEL OF EVIDENCE

Level IV, retrospective cohort study.

Ulnar Nerve Management in Distal Humerus Fracture Surgery: A Case of Developing Ulnar Neuropathy After Open Reduction and Internal Fixation

In this case report, we want to show how a patient who underwent surgery for a distal humerus fracture developed postoperative ulnar neuropathy symptoms, how nonunion persisted even at the ninth month of follow-up, and whether the nonunion was connected to the ulnar neuropathy that developed. Due to this, we used this case to explore ulnar nerve care and whether ulnar nerve transposition, manipulation, or decompression should be carried out during surgery on patients with distal humerus fractures. A 52-year-old man with a bi-columnar distal humerus fracture from a fall on his right elbow underwent open reduction and internal fixation at an external center one year before. Elbow restriction, discomfort, numbness, and weakness in the fourth and fifth digits of the right hand were all symptoms the patient experienced eight months following the surgery. We discovered the distal right humerus' nonunion during the radiological exams. It became apparent that the patient had no signs of ulnar neuropathy before the injury. In the eighth month following the injury, the patient had implant removal, open reduction internal fixation with autograft, and ulnar nerve transposition. We discovered during follow-up that the patient's ulnar neuropathy symptoms had subsided. The surgeon's familiarity with the procedure and command of the anatomy of the elbow has a role in managing the ulnar nerve in distal humerus fractures. We concluded that more study is required to determine the connection between the onset of ulnar neuropathy and nonunion while treating distal humerus fractures.

Predictors of nonunion for transverse femoral shaft fractures treated with intramedullary nailing: a SIGN database study

Introduction

Nonunion is a common postfracture complication resulting in decreased quality of life for patients in resource-limited settings. This study aims to determine how age, sex, injury mechanism, and surgical intervention affect the rate of nonunion in transverse femur fractures treated with a SIGN intramedullary nail (IMN).

Methods

A retrospective study was conducted using the SIGN online surgical database. All patients older than 16 years with simple transverse (<30 degrees), open or closed, femur fractures treated using a SIGN IMN between 2007 and 2021 were included. Our primary outcome of nonunion was measured with the modified Radiographic Union Scale for Tibial fractures (mRUST); scores ≤9 of 16 defined nonunion. The secondary outcome was squat depth. Outcomes were evaluated at follow-up appointments between 240 and 365 days postoperatively. Univariate and multivariate analysis were used for statistical comparison.

Results

Inclusion criteria were met for 182 patients. The overall radiographic union rate was 61.0%, and a high proportion (84.4%) of patients could squat with their hips at or below the level of their knees. Older age, retrograde approach, and fracture distraction were associated with nonunion, but sex, injury mechanism, and other surgical variables were not.

Conclusion

Poor reduction with fracture distraction was associated with a higher rate of nonunion. Loss of follow-up may have contributed to our overall union rate; however, we observed high rates of functional healing using the SIGN IMN.

Level of evidence

IV.

Postoperative Immobilization of Scaphoid Fractures: A Comprehensive Review of the Literature

The optimal protocol for postoperative immobilization following operative treatment of scaphoid fractures remains controversial. Reports of successful management with brief postoperative immobilization suggest that earlier restoration of function may be achieved by limiting the duration of immobilization. However, the risk of nonunion and its associated complications suggest that a more conservative approach with extended immobilization could optimize fracture healing. This paper presents a thorough review of the relevant literature and summarizes the myriad postoperative immobilization protocols and their reported outcomes. Postoperative immobilization protocols and reported outcomes for displaced, comminuted, and proximal pole fractures are discussed separately. The literature is reviewed following different operative techniques, including open reduction internal fixation and percutaneous screw fixation. Vigilant postoperative care of scaphoid fractures managed surgically is warranted to monitor for signs of nonunion while attempting to regain motion and strength to the injured wrist.

Reconstruction of the Articular Surface in the Subtalar Joint by Osteochondral Autologous Transplantation After Failure of Tibiotalocalcaneal Fusion With a Retrograde Nail: A Case Report

Tibiotalocalcaneal arthrodesis (TTCA) using the intramedullary nail has been conducted for severe deformity of both ankle and subtalar joints. While good clinical outcomes have been reported for TTCA, its nonunion rate is relatively high. We report a case of a 65-year-old male with nonunion of the tibiotalar joint and destruction of the subtalar joint after TTCA using a retrograde intramedullary nail. For this patient, we conducted a salvage procedure for the subtalar joint along with revision surgery for the tibiotalar joint to achieve bone union. The intramedullary nail was removed and the tibiotalar joint was debrided. Two osteochondral plugs were harvested from the lateral aspect of the talus and transplanted to the subtalar joint. The tibiotalar joint was fixed using screws and staples, with bone grafting. Magnetic resonance imaging (MRI) at six months after surgery showed that the articular surface of the subtalar joint was flushed and the osteochondral plugs were united with the surrounding bone. At one year and three months after surgery, the pain in the tibiotalar and subtalar joints had completely disappeared. Plain radiographs revealed that bone union of the tibiotalar joint and joint space of the subtalar joint was maintained. Japanese Society for Surgery of the Foot (JSSF) hindfoot scale improved from 53 points to 84 points at the final follow-up. Reconstruction of the subtalar joint using osteochondral autologous transplantation is a useful technique for failure cases with nonunion of the tibiotalar and subtalar joints after TTCA.

Intramedullary Nail Fixation for the Treatment of Symptomatic Fibular Nonunion: A Case Series

Ankle fractures are a relatively common injury in the lower extremity. They can be treated with conservative management if they are nondisplaced and only involve the fibula. Nonunions at the fracture site, however, are a potential complicating factor during treatment. There is growing literature supporting the use of intramedullary fixation for fracture care. Not only does it have the advantages of using smaller incisions to preserve periosteum while providing improved biomechanical outcomes, but intramedullary reaming can help stimulate cells to promote bone healing. Few articles discuss the use and success of intramedullary reaming in revision surgery of the distal fibula. We present 3 cases of computed tomography-confirmed fibular nonunion following conservative fracture care, which underwent revision surgery with fibular nail fixation technique. These cases illustrate clinical and image findings as well as highlight the surgical technique used for each patient. At follow-up, all patients were asymptomatic and radiographs confirmed healing of the previous nonunion site. These cases are examples of successful revision for fibular fracture nonunion using intramedullary nail fixation.Level of Evidence: Level IV: Case series.

Prediction of fracture nonunion leading to secondary surgery in patients with distal femur fractures

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.

Methods

We conducted a retrospective cohort study of adult patients with traumatic distal femur fracture treated with lateral locking plate between 2009 and 2018. The patients who underwent secondary surgery due to fracture healing problem or plate failure were considered having nonunion. Background knowledge of risk factors of distal femur fracture nonunion based on previous literature was used to form an initial set of variables. A logistic regression model was used with previously identified patient- and injury-related variables (age, sex, BMI, diabetes, smoking, periprosthetic fracture, open fracture, trauma energy, fracture zone length, fracture comminution, medial side comminution) in the first analysis and with treatment-related variables (different surgeon-controlled factors, e.g. plate length, screw placement, and proximal fixation) in the second analysis to predict the nonunion leading to secondary surgery in distal femur fractures.

Results

We were able to include 299 fractures in 291 patients. Altogether, 31/299 fractures (10%) developed nonunion. In the first analysis, pseudo-R2 was 0.27 and area under the receiver operating characteristic curve (AUC) was 0.81. BMI was the most important variable in the prediction. In the second analysis, pseudo-R2 was 0.06 and AUC was 0.67. Plate length was the most important variable in the prediction.

Conclusion

The model including patient- and injury-related factors had moderate fit and predictive ability in the prediction of distal femur fracture nonunion leading to secondary surgery. BMI was the most important variable in prediction of nonunion. Surgeon-controlled factors had a minor role in prediction of nonunion.

Talonavicular Arthrodesis Using a Screw and Compression Staple in a Patient With Bipartite Navicular Bone: A Case Report

The bipartite navicular bone is a relatively rare pathological condition in which the navicular bone is segmented. As a high nonunion rate in talonavicular arthrodesis of the foot has been reported, an effective fixation method is required to achieve bone union. A compression staple can provide a persistent strong compressive force on the bone surface, which is advantageous for arthrodesis, especially for the joints with a high incidence of nonunion. A 13-year-old boy presenting with left foot pain was diagnosed with bipartite navicular. Imaging of the left foot showed that the navicular bone was divided into two parts and flatfoot deformity. After the failure of conservative treatment, talonavicular arthrodesis was performed. The lateral fragment was removed, and the talar and medial fragments were fixed using a cannulated cancellous screw (CCS) (Ace Medical, El Segundo, CA, USA) and compression staple (DynaNite, 15 mm × 12 mm, Arthrex, Inc., Naples, USA) to correct the flatfoot. Bone union was achieved, and flatfoot improved. Thirteen months postoperatively, his symptoms disappeared, and all categories of the Self-Administered Foot Evaluation Questionnaire scored 100 points. Although the bipartite navicular bone has no established treatment due to its rareness, talonavicular arthrodesis using a combination of CCS and compression staple yields good short-term clinical outcomes including good alignment.

Medial Femoral Condyle Corticoperiosteal Flap for Failed Total Wrist Fusions

Background  Recalcitrant nonunion following total wrist arthrodesis is a rare but challenging problem. Most commonly, in the setting of failed fusion after multiple attempts of refixation and cancellous bone grafting, the underlying cause for the failure is invariably multifactorial and is often associated with a range of host issues in addition to poor local soft-tissue and bony vascularity. The vascularized medial femoral condyle corticoperiosteal (MFC-CP) flap has been shown to be a viable option in a variety of similar settings, which provides vascularity and rich osteogenic progenitor cells to a nonunion site, with relatively low morbidity. While its utility has been described for many other anatomical locations throughout the body, its use for the treatment of failed total wrist fusions has not been previously described in detail in the literature. Methods  In this article, we outline in detail the surgical technique for MFC-CP flap for the management of recalcitrant aseptic nonunions following failed total wrist arthrodesis. We discuss indications and contraindications, pearls and pitfalls, and potential complications of this technique. Results  Two illustrative cases are presented of patients with recalcitrant nonunions following multiple failed total wrist fusions. Conclusion  When all avenues have been exhausted, a free vascularized corticoperiosteal flap from the MFC is a sound alternative solution to achieve union, especially when biological healing has been compromised. We have been able to achieve good clinical outcomes and reliable fusion in this difficult patient population.

Risk Factors for Complications in Ulnar Shortening Osteotomies: A Multicenter Retrospective Review

PURPOSE

Ulnar shortening osteotomy (USO) is commonly performed to alleviate pathologies causing ulnar-sided wrist pain. Surgical complications include nonunion and hardware removal, with rates up to 18% and 45%, respectively. The primary objective of the study was to report the overall complication rate of USO. The secondary objective was to identify risk factors for complications.

METHODS

A retrospective multicenter cohort review was undertaken, including six Canadian cities over a 6-year period (January 2013-December 2018). Chart review was used to collect demographic data, surgical technique, implant used, and postoperative complications. Descriptive statistics of demographics and operative characteristics, including plate positioning, type of osteotomy, plate type, and ulnar variance (mm), were analyzed. Univariate analyses were used to select predictor variables for nonunion and hardware removal. These predictor variables were then entered into an adjusted multivariable logistic regression model.

RESULTS

A total of 361 USOs were performed. Mean age was 46 ± 16 years (60.7% men). The overall complication rate was 37.1%, hardware removal rate was 29.6%, and nonunion rate was 9.4%. There was a workers' compensation claim associated with 21.6% of all complications, and it was a risk factor for both hardware removal (odds ratio [OR] = 3.81) and nonunion (OR = 2.88). Neither smoking nor diabetes was associated with complication rates. Seventy percent of plates were placed volarly, 25.5% dorsally, and 3.9% directly ulnar. Osteotomies were oblique in 83.7% of cases and transverse in 15.5%. Adjusted multivariate regression analysis revealed that younger age (OR = 0.98) was a risk factor for hardware removal and male sex (OR = 0.40) was a risk factor for nonunion. A surgical factor associated with hardware removal was direct ulnar plate placement (OR = 9.93). No surgical factors were associated with nonunions.

CONCLUSIONS

There are substantial rates of complications with USOs. Direct ulnar plate placement should be avoided. Patients should be thoroughly counseled on the risks of complications prior to proceeding with USO.

LEVEL OF EVIDENCE

Therapeutic IV.

What Is the Best Treatment of the Femoral Shaft Nonunion after Intramedullary Nailing? A Systematic Review

Nonunion (NU) is one of the most feared complications of femoral shaft fracture treatment. Femoral shaft fracture treatment is often linked with poor bone stock and reduced bone metabolism. In this paper, the goal is to carefully analyze the best treatment options for patients who developed nonunion after the intramedullary nailing of a femoral shaft fracture. A systematic review of the literature available in the PubMed, EMBASE and Cochran library databases was carried out, and 16 studies were included. Exclusion criteria included case reports and case series that do not have data about clinical outcomes or functional outcomes and included fewer than 10 patients. The reviewed data provide evidence for very good results about the treatment of this pathology with exchanging intramedullary nails or the implantation of a plate and screws (general healing rate of 96.3%). Moreover, the data support the utilization of autologous bone graft in order to stimulate the healing process. In conclusion, the choice between these two types of treatment must be guided by the type of pseudarthrosis that the patient presents. Additionally, bone grafting or growth factors promote bone regenerative processes, especially in patients with oligo-atrophic pseudoarthrosis.

Association of Preexisting Triple Fusion and Arthroscopic Ankle Arthrodesis nonunion

BACKGROUND

Arthroscopic ankle arthrodesis (AAA) is a successful treatment for end-stage ankle arthritis. A significant early complication of AAA is symptomatic nonunion. Published nonunion rates range from 8% to 13%. Longer term, there is concern that it predisposes to subtalar joint (STJ) fusion. To better understand these risks, we undertook a retrospective investigation of primary AAA.

METHODS

All adult AAA cases conducted at our institution over a 10-year period were reviewed. A total of 284 eligible AAA cases in 271 patients were analyzed. The primary outcome measure was radiographic union. Secondary outcome measures included reoperative rate, postoperative complications and subsequent STJ fusion. Univariate and multivariate logistic regression analysis was performed to identify nonunion risk factors.

RESULTS

The overall nonunion rate was 7.7%. Smoking (odds ratio [OR] 4.76 [1.67, 13.6], P = .004) and previous triple fusion (OR 40.29 [9.46, 171.62], P < .001) were independent risk factors on univariate analysis. Only prior triple fusion persisted as a major risk factor associated with nonunion on multivariate analysis (OR 18.3 [3.4, 99.7], P < .001). Seventy percent of patients with a previous triple fusion went on to develop nonunion compared to 5.5% of those without. Increasing age, obesity, surgical grade, diabetes, postoperative weightbearing plan, steroid use, and inflammatory arthropathy were not significant risk factors. The leading cause of reoperation was hardware removal (18%). There were 5 superficial (1.8%) and 4 deep (1.4%) infections. Eleven (4.2%) required subsequent STJ fusion. The "survivorship" of STJ post AAA was 98%, 85%, and 74% at 2, 5, and 9 years, respectively.

CONCLUSION

As the largest study of AAA in the literature, our findings suggest prior triple fusion is a major independent risk factor for AAA nonunion. These patients should be counseled of this high risk and may benefit from alternative surgical options.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

CT-Verified Union Rate Following Arthrodesis of Ankle, Hindfoot, or Midfoot: A Systematic Review

BACKGROUND

Ankle, hindfoot, and midfoot arthrodesis surgeries are standard procedures performed in orthopaedics to treat pain and functional disabilities. Although fusions can effectively improve pain and quality of life, nonunions remain a significant concern for surgeons. With the increased availability of computed tomography (CT), more surgeons rely on this modality for increased accuracy in determining whether a fusion was successful. The objective of this study was to report the rates of CT-confirmed fusion following ankle, hindfoot, or midfoot arthrodesis.

METHODS

A systematic review was performed using EMBASE, Medline, and Cochrane central register from January 2000 to March 2020. Inclusion criteria included studies with adults (<18 years) that received 1 or multiple fusions of the ankle, hindfoot, or midfoot. At least 75% of the study cohort must have been evaluated by CT postoperatively. Basic information was collected, including journal, author, year published, and level of evidence. Other specific information was collected, including patient risk factors, fusion site, surgical technique and fixation, adjuncts, union rates, criteria for successful fusion (%), and time of CT. Once data were collected, a descriptive and comparative analysis was performed.

RESULTS

Included studies (26, n = 1300) had an overall CT-confirmed fusion rate of 78.7% (69.6-87.7). Individual joints had an overall fusion rate of 83.0% (73-92.9). The highest rate of union was in the talonavicular joint (TNJ).

CONCLUSION

These values are lower than previous studies, which found the same procedures to have greater than 90% fusion rates. With these updated figures, as confirmed by CT, surgeons will have better information for clinical decision making and when having informed consent conversations.

Matched-Pair Analysis: Large-Sized Defects in Surgery of Lower Limb Nonunions

BACKGROUND

The treatment of large-sized bone defects remains a major challenge in trauma and orthopaedic surgery. Although there are many treatment options, there is still no clear guidance on surgical management, and the influence of defect size on radiological and clinical outcome remains unclear due to the small number of affected patients. The aim of the present study was to determine the influence of defect size on the outcome of atrophic and infected nonunions of the tibia or the femur based on the diamond concept in order to provide recommendations for treatment guidance.

PATIENTS AND METHODS

All medical records, surgical reports, laboratory data and radiological images of patients treated surgically for atrophic or infected nonunions of the lower limbs (femur or tibia) between 1 January 2010 and 31 December 2020 were examined. Patients with proximal, diaphyseal or distal nonunions of the femur or tibia who were surgically treated at our institution according to the "diamond concept" and attended our standardised follow-up program were included in a database. Surgical treatment was performed as a one- or two-step procedure, depending on the type of nonunion. Patients with a segmental bone defect ≥5 cm were matched with patients suffering a bone defect <5 cm based on five established criteria. According to our inclusion and exclusion criteria, 70 patients with a bone defect ≥5 cm were suitable for analysis. Two groups were formed by matching: the study group (bone defect ≥5 cm; n = 39) and control group (bone defect <5 cm; n = 39). The study was approved by the local ethics committee (S-262/2017).

RESULTS

The mean defect size was 7.13 cm in the study and 2.09 cm in the control group. The chi-square test showed equal consolidation rates between the groups (SG: 53.8%; CG: 66.7%). However, the Kaplan-Meier curve and log-rank test showed a significant difference regarding the mean duration until consolidation was achieved, with an average of 15.95 months in the study and 9.24 months in the control group (α = 0.05, p = 0.001). Linear regression showed a significant increase in consolidation duration with increasing defect size (R² = 0.121, p = 0.021). Logistic regression modelling showed a significant negative correlation between consolidation rate and revision performance, as well as an increasing number of revisions, prior surgeries and total number of surgeries performed on the limb. Clinical outcomes showed equal full weight bearing of the lower extremity after 5.54 months in the study vs. 4.86 months in the control group (p = 0.267).

CONCLUSION

Surprisingly, defect size does not seem to have a significant effect on the consolidation rate and should not be seen as a risk factor. However, for the treatment of large-sized nonunions, the follow-up period should be prolonged up to 24 months, due to the extended time until consolidation will be achieved. This period should also pass before a premature revision with new bone augmentation is performed. In addition, it should be kept in mind that as the number of previous surgeries and revisions increases, the prospects for consolidation decrease and a change in therapeutic approach may be required.

Treatment of a Large Defect Induced by Atrophic Nonunion of Femoral Fracture in a Dog with Autogenous Coccygeal Bone Grafting

An 11-month-old castrated male Pomeranian presented with nonunion following a femoral fracture that occurred after femoral head and neck osteotomy. Radiography and computed tomography revealed severe atrophy of the proximal bone fragment and retardation of the ipsilateral distal fragment and tibia. An autogenous bone graft using coccygeal bone was performed, in which three and a half coccyges were placed in succession and fixed using an orthogonal locking plate. To promote bone healing and facilitate proper weight bearing and ambulation, bone morphogenetic proteins, biphasic calcium phosphate, platelet-rich plasma, passive-range-of-motion exercises, transcutaneous electrical nerve stimulation, neuromuscular electrical stimulation, and low-level laser therapy were applied. During the four-year follow-up, it was observed that the previously engrafted bone healed well and maintained stability over a prolonged period, resulting in the patient being able to walk comfortably with good outcomes. However, some degree of lameness was noted in the dog when running owing to limb shortening and joint contracture.

Genetic Influence of Fracture Nonunion (FNU): A Systematic Review

Purpose

Nonunion of fractures occurs in about 15% of all fractures causing repeated surgical interference and prolonged morbidity. We performed this systematic review to assess genes and polymorphisms influencing fractures' nonunion (FNU).

Methods

We searched between 2000 and July 2022 in PubMed, EMBASE, the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Genome Wide Association Studies (GWAS) Catalog, and the Science Citation Index, with the keywords nonunion of fractures, genetic influence, and GWAS. The exclusion criteria were review articles and correspondence. The data were retrieved to determine the number of studies, genes, and polymorphisms and the total number of subjects screened.

Results

A total of 79 studies were reported on nonunion of fractures and genetic influence. After the inclusion and exclusion criteria, ten studies with 4402 patients' data were analyzed. Nine studies were case-controlled, and 1 GWAS. It was identified that patients with polymorphisms in the genes ANXA3, BMP2, CALY, CYR61, FGFR1, IL1β, NOG, NOS2, PDGF gene, and TACR1 are prone to develop a nonunion of fractures.

Conclusion

We believe that for patients who develop an early nonunion of fractures, a genetic study should be conducted for single nucleotide polymorphism (SNP) and genes so that alternative and more aggressive treatment can be performed to heal fractures without prolonged morbidity.

Humerus fractures: selecting fixation for a successful outcome

Current evidence suggests at least one-third of humeral shaft fractures initially managed nonoperatively will fail closed treatment, and this review highlights surgical considerations in those circumstances. Although operative indications are well-defined, certain fracture patterns and patient cohorts are at greater risk of failure. When operative intervention is necessary, internal fixation through an anterolateral approach is a safe and sensible alternative. Determining which patients will benefit most involves shared decision-making and careful patient selection. The fracture characteristics, bone quality, and adequacy of the reduction need to be carefully evaluated for the specific operative risks for individuals with certain comorbid conditions, inevitably balancing the patient's expectations and demands against the probability of infection, nerve injury, or nonunion. As our understanding of the etiology and risk of nonunion and symptomatic malunion of the humeral diaphysis matures, adhering to the principles of diagnosis and treatment becomes increasingly important. In the event of nonunion, respect for the various contributing biological and mechanical factors enhances the likelihood that all aspects will be addressed successfully through a comprehensive solution. This review further explores specific strategies to definitively restore function of the upper extremity with the ultimate objective of an uninfected, stable union.

Is human immunodeficiency virus a risk factor for the development of nonunion?-a case-control study

Objective

Human immunodeficiency virus (HIV) infection has been suggested to be associated with an increased risk of the development of nonunion after a fracture. This prospective matched case-control study in South Africa investigated common risk factors, including HIV status, that influence the development of a nonunion after a femur or tibia fracture.

Methods

Adult participants (cases) with established nonunions of the femur or tibia shaft were recruited over a 16-month period, between December 2017 and April 2019. They were matched for (1) age; (2) sex; (3) fracture site; and (4) fracture management type, with "control" participants who progressed to fracture union within 6 months of injury. All participants were tested for HIV. Multivariable logistic regression models were constructed to investigate associations between known risk factors for the development of nonunion and impaired fracture healing.

Results

A total of 57 cases were matched with 57 "control" participants (44/57 male, 77.2% vs. 13/57 female, 22.8%, median age 36 years). HIV status was not associated with the development of nonunion after the management of tibia and femur fractures, on both univariate (odds ratio, 0.40; confidence interval, 0.10-1.32; P = 0.151) or multivariable (odds ratio, 0.86; confidence interval, 0.18-3.73; P = 0.831) analysis. No other confounding factors were shown to have any statistically significant impact on the odds of developing nonunion in this study cohort.

Conclusion

This study demonstrates that HIV does not seem to increase the risk of the development of nonunion and HIV-positive individuals who sustain a fracture can be managed in the same manner as those who are HIV negative.

Management of aseptic nonunions and severe bone defects: let us get this thing healed!

Effective nonunion and bone defect management requires consideration of multiple potential contributing factors including biomechanics, biology, metabolic, and patient factors. This article reviews these factors as well as several potential nonunion or bone defect treatments including bone grafts, bone graft substitutes, the induced membrane technique, and distraction osteogenesis. A summary of these concepts and guidelines for an overall approach to management are also provided.

Blade Plate With Autogenous Bone Grafting to Salvage Peri Ankle Nonunions

BACKGROUND

Salvage surgery for a nonunion around the ankle is challenging. Poor bone stock, stiffness, scarring, previous (or persistent) infection, and a compromised soft tissue envelope are common in these patients. We describe 15 cases that underwent blade plate fixation as salvage for a nonunion around the ankle, including patient/nonunion characteristics, Nonunion Scoring System (NUSS), surgical technique, healing rate, complications, and long-term follow-up with 2 patient-reported outcome measures.

METHODS

This is a retrospective case series from a level 1 trauma referral center. We included all patients that underwent blade plate fixation for a long-standing nonunion of the distal tibia, talus, or failed subtalar fusion. All patients had autogenous bone grafting, including 14 with posterior iliac crest grafts and 2 with femoral reamer irrigator aspirator grafting. Median follow-up was 24.4 months (interquartile range [IQR], 7.7-40). Main outcome measures were (time to) union, and functional outcomes using the 36-item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS), and the Foot and Ankle Outcome Score (FAOS).

RESULTS

We included 15 adults with a median age of 58 years (IQR, 54-62). The median NUSS score at the time of index surgery was 46 (IQR, 34-54). Union was achieved after the index procedure in 11 of 15 patients. Additional surgery was performed in 4 of 15 patients. Union was achieved in all patients at a median of 4.2 months (IQR, 2.9-11). The median score for the PCS was 38 (IQR, 34-48, range 17-58, P = .009), for the MCS 52 (IQR, 45-60, range 33-62, P = .701), and for the FAOS 73 (IQR, 48-83).

CONCLUSION

In this series, our use of blade plate fixation with autogenous grafting was an effective method for managing a nonunion around the ankle allowing for alignment correction, stable compression and fixation, union, and fair patient-reported outcome scores.

LEVEL OF EVIDENCE

Level IV, therapeutic.

The Trans-Achilles Approach for Plate Supplementation of Ankle Arthrodesis With an Existing Hindfoot Fusion Nail: A Case Report

Tibiotalar arthrodesis revision surgeries are not uncommon. Several approaches have been described in the literature for ankle arthrodesis nonunions. In this article, we describe the posterior trans-Achilles approach, which ensures adequate surgical exposure while minimizing damage to the surrounding soft tissues. It provides a convenient method for utilizing bone grafts or substitutes and allows for the advantageous application of posterior plating. The possible complications of this approach are delayed wound healing, wound infection, injury to the sural nerve, and the potential need for a skin graft. Despite the advantages of this approach, infection, delayed union, and nonunion risks remain high in this patient population. Finally, the trans-Achilles approach is valid for complex ankle procedures, especially in revisions with compromised ankle soft tissue envelopes.

Single-cell RNAseq provides insight into altered immune cell populations in human fracture nonunions

Nonunion describes bone fractures that fail to heal, resulting in the fracture callus failing to fully ossify or, in atrophic cases, not forming altogether. Fracture healing is regulated, in part, by the balance of proinflammatory and anti-inflammatory processes occurring within the bone marrow and surface cell populations. We sought to further understand the role of osteoimmunology (i.e., study of the close relationship between the immune system and bone) by examining immune cell gene expression via single-cell RNA sequencing of intramedullary canal tissue obtained from human patients with femoral nonunions. Intramedullary canal tissue samples obtained by reaming were collected at the time of surgical repair for femur fracture nonunion (n = 5) or from native bone controls when harvesting autologous bone graft (n = 4). Cells within the samples were isolated and analyzed using the Chromium Single-Cell System (10x Genomics Inc.) and Illumina sequencers. Twenty-three distinct cell clusters were identified, with higher cell proportions in the nonunion samples for monocytes and CD14 + dendritic cells (DCs), and lower proportions of T cells, myelocytes, and promyelocytes in nonunion samples. Gene expression differences were identified in each of the cell clusters from cell types associated with osteoimmunology, including CD14 + DC, monocytes, T cells, promyelocytes, and myelocytes. These results provide human-derived gene profiles that can further our understanding of pathways that may be a cause or a consequence of nonunion, providing the clinical rationale to focus on specific components of osteoimmunology. Clinical significance: The novel single-cell approach may lead to clinically relevant diagnostic biomarkers during earlier stages of nonunion development and/or investigation into therapeutic options.

Medial Condyle Fracture of the Distal Humerus in an Elderly Patient With Fishtail Deformity and Lateral Condyle Nonunion: A Case Report

A medial condyle fracture of the humerus with preexisting fishtail deformity and lateral condyle nonunion is very rare, and there have been few reports describing favorable treatment options. We herein report the case of an 83-year-old woman who sustained a medial condyle fracture of her elbow with a comorbidity of long-lasting limited elbow motion with a history of elbow trauma in childhood. After conservative treatment with casting for four weeks, unstable medial condyle fracture in the presence of fishtail deformity and lateral condyle nonunion remained. Due to persistent pain, the patient underwent surgical treatment with semiconstrained total elbow arthroplasty (TEA) through the triceps-on approach. At the 12-month follow-up examination, the patient had no pain and achieved satisfactory functional outcomes. This case report demonstrated the efficacy of TEA for deteriorated stability due to bilateral condyle fracture/nonunion with fishtail deformity of the humerus.

Effect of Postoperative Ketorolac Administration on the Union Rate Following First Metatarsophalangeal Joint Arthrodesis

BACKGROUND

To decrease postoperative opioid consumption, nonsteroidal anti-inflammatory drugs (NSAIDs), including ketorolac, are considered a proper substitute with few side effects. Our null hypothesis is that a standard-dose, short-term ketorolac exposure does not increase the nonunion rate of a first metatarsophalangeal joint (MTPJ) arthrodesis.

METHODS

In a retrospective cohort study, we included 181 primary first MTPJ arthrodeses from 2016 to 2020 in a single surgeon practice. The surgical technique was identical using a dorsal locking plate after preparing the joint with the cup-and-cone technique. A 30 mg intravenous dose of ketorolac was administered perioperatively, followed by a post-operative oral course of 10 mg oral ketorolac every 6 hours for 5 consecutive days. Patients were placed in a heel weight-bearing CAM boot for a minimum of 6 weeks. Union was determined radiographically at 3 months postoperative. Radiographic nonunion was also categorized clinically as symptomatic versus asymptomatic.

RESULTS

At 3 months postoperative, a nonunion occurred in 15 (8.3%) patients. Of the 15 radiographic nonunions, 7 (45%) were clinically asymptomatic, while the other 8 (55%) were symptomatic. Six (75%) of the 8 symptomatic nonunions ultimately underwent revision surgery. The nonunion rate in our study compared to that described in the literature (5.4%) was similar and showed no significant difference (P = .067).

CONCLUSION

The use of a short course of oral ketorolac (40 mg/day or less for a maximum of 5 days) does not seem to affect the union rate after first MTPJ arthrodesis and can be used safely and effectively in the management of post-operative pain to decrease opioid consumption following this procedure.

LEVELS OF EVIDENCE

Level 4.