Induced membrane technique for acute bone loss and nonunion management of the tibia

Can limb length discrepancies be corrected with the Masquelet technique? A technical trick

Masquelet technique is a well-established procedure for reconstruction of bone defects secondary to such causes as infections, non-unions, tumors or open fractures with bone loss. The management of limb length discrepancies following bone defects has been well established using bone transport and remains the preferred choice amongst reconstruction surgeons. One of the criticisms of the Masquelet technique has been its limitation to address limb length discrepancies. We describe a technique for the correction of limb length discrepancies using the Masquelet technique.

Clinical management and innovation in fracture non-union

INTRODUCTION

With the introduction and continuous improvement in operative fracture fixation, even the most severe bone fractures can be treated with a high rate of successful healing. However, healing complications can occur and when healing fails over prolonged time, the outcome is termed a fracture non-union. Non-union is generally believed to develop due to inadequate fixation, underlying host-related factors, or infection. Despite the advancements in fracture fixation and infection management, there is still a clear need for earlier diagnosis, improved prediction of healing outcomes and innovation in the treatment of non-union.

AREAS COVERED

This review provides a detailed description of non-union from a clinical perspective, including the state of the art in diagnosis, treatment, and currently available biomaterials and orthobiologics.Subsequently, recent translational development from the biological, mechanical, and infection research fields are presented, including the latest in smart implants, osteoinductive materials, and in silico modeling.

EXPERT OPINION

The first challenge for future innovations is to refine and to identify new clinical factors for the proper definition, diagnosis, and treatment of non-union. However, integration of in vitro, in vivo, and in silico research will enable a comprehensive understanding of non-union causes and correlations, leading to the development of more effective treatments.

Critical size bone defects managed with modern techniques of bone transport: An update

Bone transport is one of several techniques that has been proven to be effective in addressing critical bone loss. While it was first described over 100 years ago, modifications to this technique coupled with advances in technology have allowed us to perform bone transport with higher success rates and reduced complication rates. Modern techniques of bone transport aim to shorten the duration of time an external fixator is utilized to reduce its associated complications and burden to patients. We present an update on modern techniques of bone transport for critical size defects and methods to shorten the external fixation time.

Nonvascularized fibular graft with locking screw fixation for metaphyseal bone loss of distal femur: biomechanical assessment validated by a clinical case series

BACKGROUND

The optimal modality to surgically treat significant bone loss of distal femur remains inconclusive. The objectives of the present study were to assess the mechanical performance of nonvascularized fibular graft (NVFG) with locking screw fixation in distal femur fixation construct by finite element analysis and to retrospectively describe the outcomes of the present technique in clinical cases.

METHODS

Four constructs which the fractured femur was stabilized by LCP-DF alone, dual plating, LCP-DF combined with NVFG, and LCP-DF combined with NVFG (LCP-DF-NVFG-S) with locking screw were assessed the biomechanical performance under physiological loads. For the clinical case series, 12 patients with open intercondylar fracture with metaphyseal bone loss of distal femur were operated by LCP-DF-NVFG-S. The collected data included fracture consolidation, length of NVFG, perioperative complications and objective clinical results.

RESULTS

LCP-DF-NVFG-S demonstrated lower implant equivalent von Mises stress (EQV) stress and better fracture stability than other constructs. A locking screw presented its essence in maintaining the NVFG in the required position and subsequently enhancing the fracture stability. In regard to the clinical series, all fractures were consolidated with an average duration of 27.8 weeks (range 20-32). An average NVFG length was 7.8 cm (range 6-12). No perioperative complication was demonstrated. By the Knee Society score, 1 was considered to be excellent, 9 to be good and 2 to be poor.

CONCLUSION

Based on the results of mechanical assessment and case series, LCP-DF-NVFG-S can be an effective technique in the management of metaphyseal bone loss of distal femur.

Restoring the Anatomy of Long Bones with Large Septic Non-Union Defects with the Masquelet Technique

Objectives: Septic non-union in long-bone fractures represents a challenging clinical entity. Management of lower extremity segmental bone defects, aiming to restore functional anatomy, remains extremely difficult and controversial. Masquelet technique is a reconstruction method for large diaphyseal bone defects, based on the notion of the induced membrane. The principle of the induced membrane is to create a foreign body reaction by placing cement spacer in the bone defect. The purpose of this study was to assess the success rate of induced membrane technique (IMT) in treating lower extremity large bone defects due to septic non-union. Methods:This is a retrospective observational study performed in a single referral center in France, Europe, which is specialized in complex bone and joint infections. All patients operated for septic non-union were identified from a prospectively maintained database. Patients treated with the IMT for septic femoral or tibial non-union between 2013 and 2017 were enrolled in this study. Exclusion criteria were infection of a continuous bone, aseptic non-union, or patients with less than one year of follow-up after antibiotic treatment ending. Results:Twenty-three cases (19 patients) with an average age of 41.3 years were included in the present study. There were 19 tibial and four femoral fractures. The mean bone defect was 65.3 mm. The mean time interval from initial trauma to the first surgical phase was 17 months, while that between the two surgical phases was 77.7 days. After the first surgical phase, samples were positive in 13 cases (68.5%), isolating Staphylococcus (26%) and more than one pathogen in 22% of cases. Bone union was successful in 16 of 23 cases (69.6%, 14 patients). There were seven failures: five amputations due to mechanical and/or infection-related failure and two failed unions. Conclusion:This study found that 69% of cases with septic non-union of tibial or femoral fracture treated with the two-step surgical protocol achieved bone union and infection eradication within about 13.2 months after the second stage of the procedure. The study revealed promising results in patients suffering large-size bone defect; hence, the IMT may prove beneficial in the management of such cases.

Biological aspects to enhance fracture healing

The ability to enhance fracture healing is paramount in modern orthopaedic trauma, particularly in the management of challenging cases including peri-prosthetic fractures, non-union and acute bone loss. Materials utilised in enhancing fracture healing should ideally be osteogenic, osteoinductive, osteoconductive, and facilitate vascular in-growth. Autologous bone graft remains the gold standard, providing all of these qualities. Limitations to this technique include low graft volume and donor site morbidity, with alternative techniques including the use of allograft or xenograft. Artificial scaffolds can provide an osteoconductive construct, however fail to provide an osteoinductive stimulus, and frequently have poor mechanical properties. Recombinant bone morphogenetic proteins can provide an osteoinductive stimulus; however, their licencing is limited and larger studies are required to clarify their role. For recalcitricant non-unions or high-risk cases, the use of composite graft combining the above techniques provides the highest chances of successfully achieving bony union.

One Stage Masquelets Technique: Evaluation of Different Forms of Membrane Filling with and without Bone Marrow Mononuclear Cells (BMC) in Large Femoral Bone Defects in Rats

The classic two-stage masquelet technique is an effective procedure for the treatment of large bone defects. Our group recently showed that one surgery could be saved by using a decellularized dermis membrane (DCD, Epiflex, DIZG). In addition, studies with bone substitute materials for defect filling show that it also appears possible to dispense with the removal of syngeneic cancellous bone (SCB), which is fraught with complications. The focus of this work was to clarify whether the SCB can be replaced by the granular demineralized bone matrix (g-DBM) or fibrous demineralized bone matrix (f-DBM) demineralized bone matrix and whether the colonization of the DCD and/or the DBM defect filling with bone marrow mononuclear cells (BMC) can lead to improved bone healing. In 100 Sprague Dawley rats, a critical femoral bone defect 5 mm in length was stabilized with a plate and then encased in DCD. Subsequently, the defect was filled with SCB (control), g-DBM, or f-DBM, with or without BMC. After 8 weeks, the femurs were harvested and subjected to histological, radiological, and biomechanical analysis. The analyses showed the incipient bony bridging of the defect zone in both groups for g-DBM and f-DBM. Stability and bone formation were not affected compared to the control group. The addition of BMCs showed no further improvement in bone healing. In conclusion, DBM offers a new perspective on defect filling; however, the addition of BMC did not lead to better results.

Conversion of External Fixator to Intramedullary Nail in Tibial fractures

INTRODUCTION

Conversion of provisional external fixation to intramedullary nail (IMN) in femur fractures has been reported to be safe within 14 days of initial surgery. However, there is no current literature guiding this practice in tibial fractures. The purpose of this study was to identify the time period when conversion of external fixation to nail in tibial fractures is safe.

METHODS

After obtaining IRB approval, tibial fractures (OTA 41A, 42, 43A) that received provisional ex-fix and were converted to IMN from 2009 to 2019 were retrospectively reviewed. Skeletally mature patients with minimum 6 months of follow-up were included. The primary outcome was deep infection. External fixation days were categorized as less than 7, 8 to 14, and 15+ days. Risk ratios of infection were estimated using generalized linear regression with a Poisson distribution. A separate regression model evaluated risk factors for infection using both the external fixation and non-external fixation tibial cohorts.

RESULTS

Twenty-eight patients (32%) were treated for deep infection. The infection rate for closed fractures was 28% (11 of 39 patients) and for open fractures was 35% (17 of 49 patients) ( P = 0.56). Examining both tibial cohorts, external fixation (odds ratio [OR] = 2.39, P = 0.017), open fracture (OR = 3.13, P = 0.002), and compartment syndrome (OR = 2.58, P = 0.01) were all associated with infection in regression modeling. Median external fixation days for patients with deep infection was 8 days (Inter-quartile range, 3 to 18 days) as compared with 4 days (IQR, 2 to 9 days) in patients without infection ( P = 0.06). While controlling for open fractures, the 8- to 14-day group had RR = 1.81 ( P = 0.2), and the 15+-day group had RR = 2.67 ( P = 0.003) as compared with the <7-day group.

DISCUSSION

Infection rates of tibial fracture patients treated with external fixation and converted to IMN were high. Surgeons should strongly consider the necessity of external fixation for these fractures. Earlier conversion of external fixation to definitive fixation reduced infection rates.

LEVEL OF EVIDENCE

Level IV-case series.