The Accordion Maneuver: A Noninvasive Strategy for Absent or Delayed Callus Formation in Cases of Limb Lengthening

Reverse Dynamization Accelerates Regenerate Bone Formation and Remodeling in a Goat Distraction Osteogenesis Model

UPDATE

This article was updated on December 20, 2023, because of previous errors, which were discovered after the preliminary version of the article was posted online. Figure 4 has been replaced with a figure that presents different p values. Also, on page 1943, the text that had read: "Quantitative microCT confirmed that the total volume of the regenerate in the RD group was much smaller compared with the SF (p = 0.06) and DF (p = 0.007) groups, although it was significantly smaller only compared with the DF group (Fig. 4-A). The total volume of the intact bone (contralateral tibia) was significantly smaller in the RD group compared with the other groups, but the RD group had values closest to those for the intact tibia. Similarly, the RD group had less bone volume compared with the SF and DF groups, and this value was significantly different from the DF group (p = 0.034; Fig. 4-B). Of the 3 groups, the RD group had vBMD that was the closest to that of intact bone. It also had significantly higher vBMD compared with the SF and DF groups (p < 0.0001 for both; Fig. 4-C).The results of torsional testing (Fig. 4-D) confirmed that the regenerate bone formed under conditions of RD was significantly stronger than that formed under SF or DF (p < 0.001 versus SF group, and p = 0.0493 versus DF group)."now reads: "Quantitative microCT confirmed that the total volume of the regenerate in the RD group was significantly smaller compared with the SF and DF groups (p < 0.01 for both groups; Fig. 4-A). The total volume of the intact bone (contralateral tibia) was significantly smaller compared with the SF and DF groups (p < 0.0001 for both). The RD group had values closest to those for the intact tibia, and this difference was not significant (Fig. 4-A). Similarly, the RD group had less bone volume compared with the SF and DF groups, and this value was significantly different from the DF group (p < 0.01; Fig. 4-B). Of the 3 groups, the RD group had vBMD that was the closest to that of intact bone, but the intact bone was significantly different compared with all of the other groups (p < 0.0001 for all groups). The RD group had significantly higher vBMD compared with the SF and DF groups (p = 0.042 and p = 0.046, respectively; Fig. 4-C).The results of torsional testing (Fig. 4-D) confirmed that the regenerate bone formed under conditions of RD was significantly stronger than that formed under SF or DF (p < 0.0001 versus SF group, and p = 0.0493 versus DF group). The intact group was significantly different compared with the SF group (p < 0.0001)."

Results of Ilizarov external fixator lengthening compared to lengthening and then plating in management of femoral shortening in children

Femoral shortening in children is a challenging condition with complex functional and psychological implications. We study the results of Ilizarov external fixator (IEF) lengthening compared to lengthening and then plating (LAP) in the management of femoral shortening in children. Forty patients were included in the study and equally divided randomly into 2 groups, in group I LAP was used and in group II lengthening by IEF only was done. The two groups were analyzed for postoperative variables to adjudge the surgical outcomes. The mean follow up time was 24.05 ± 2.99 months, The gained length was 5.60 ± 0.60 cm in group 1 and 5.48 ± 0.64 cm in group II, group I had a shorter external fixator period (3.96 ± 0.22) months, better healing index (24.6 ±2.76) days/cm, earlier complete weight-bearing (5.55 ± 0.78) months than group II. The period of hospitalization for group I was longer more than group II. The complications were less in group I (n=7, 35%) than in group II (n=11, 55%). There was no significant correlation between the healing index with age, also no significant difference was detected between the healing index and gender. There was a significant correlation between the gained length and complete weight-bearing. This study efficiently demonstrates that LAP may be better than lengthening with IEF alone in the management of femoral shortening in children.

Clinical outcomes of bone transport using rail fixator in the treatment of femoral nonunion or bone defect caused by infection

Purpose

The rail fixator can improve the treatment outcome and provide good stability in patients with femoral bone transport. The purpose of this study is to investigate the clinical outcomes of bone transport using the Ilizarov technique by rail fixator in the treatment of femoral nonunion or bone defects caused by infection.

Methods

Clinical feature and treatment outcomes of 32 consecutive adult patients with femoral nonunion or bone defect caused by infection from January 2012 to January 2019 at a minimum of 2 years of follow-ups were retrospectively analyzed. Data were collected on participants' demographic details. All difficulties related to bone transport were documented according to Paley's classification. The clinical outcomes were evaluated using ASAMI criteria at the last clinical visit.

Results

All 32 patients with an average follow-up of 33.5 months. There were 17 problems, 21 obstacles, and 8 complications, and the complication rate per patient was 1.4. The main complications were pin-site infection (53.1%), axial deviation (21.9%), joint stiffness (18.8%), the delayed union of the docking site (18.8%), soft tissue incarceration(15.6%), delayed consolidation(6.3%), malunion(6.3%), and refracture (3.1%). All the patients achieved bone union, and no recurrence of infection was observed. The excellent and good rates of ASAMI bone and functional results were 87.5% and 81.3%, respectively.

Conclusion

Bone transport using the Ilizarov technique is an effective method for the treatment of femoral nonunion or bone defect caused by infection, and rail fixators have obtained satisfactory results in terms of bone and functional results.

Effect of the accordion technique on bone regeneration during distraction osteogenesis: A computational study

BACKGROUND AND OBJECTIVE

Distraction osteogenesis (DO), a bone lengthening technique, is widely employed to treat congenital and acquired limb length discrepancies and large segmental bone defects. However, a major issue of DO is the prolonged consolidation phase (10-36 months) during which patients must wear a cumbersome external fixator. Attempts have been made to accelerate the healing process of DO by an alternating distraction and compression mode (so-called "accordion" technique or AT). However, it remains unclear how varied AT parameters affect DO outcomes and what the most effective AT mode is.

METHODS

Based on an experimentally-verified mechanobiological model, we performed a parametric analysis via in silico simulation of the bone regeneration process of DO under different AT modes, including combinations of varied application times (AT began at week 1-8 of the consolidation phase), durations (AT was used continuously for 1 week, 2 weeks or 4 weeks) and rates (distraction or compression at 0.25, 0.5, 0.75, and 1 mm/12 h). The control group had no AT applied during the consolidation phase.

RESULTS

Compared with the control group (no AT), AT applied at an early consolidation stage (e.g. week 1 of the consolidation phase) significantly enhanced bone formation and reduced the overall healing time. However, the effect of AT on bone healing was dependent on its duration and rate. Specifically, a moderate rate of AT (e.g. 0.5 mm/12 h) lasting for two weeks promoted blood perfusion recovery and bone regeneration, ultimately shortening the healing time. Conversely, over-high rates (e.g. 1 mm/12 h) and longer durations (e.g. 4 weeks) of AT adversely affected bone regeneration and blood perfusion recovery, thereby delaying bone bridging.

CONCLUSIONS

These results suggest that the therapeutic effects of AT on DO are highly dependent of the AT parameters of choice. Under appropriate durations and rates, the AT applied at an early consolidation phase is beneficial for blood recovery and bone regeneration. These results may provide a basis for selecting effective AT modes to accelerate consolidation and reduce the overall treatment period of DO.

Open versus closed pilon fractures: Comparison of management, outcomes, and complications

BACKGROUND

Despite the low incidence of pilon fractures amongst lower limb injuries, their high impact nature presents difficulties in surgical management and recovery. The high complication rate and long recovery times presents a challenge for surgeons and patients. Current literature is varied, with no universal treatment algorithm. We aim to highlight differences in outcomes and complications between open and closed pilon fractures, and between patients treated by open reduction internal fixation (ORIF) or fine wire fixator (FWF) for open and closed fracture subgroups.

METHODS

This retrospective study was conducted at a major trauma centre including 135 patients over a 6-year period. Primary outcome was AOFAS score at 3, 6, and 12-months post-injury. Secondary outcomes included time to partial weight-bear (PWB) and full weight-bear (FWB), bone union time, and complications during the follow-up time. AO/OTA classification was used (43A: n = 23, 43B: n = 30, 43C: n = 82). Interobserver agreement was high for bone union time (kappa=0.882) and AO/OTA class (kappa=0.807).

RESULTS

Higher AOFAS scores were seen in ORIF groups of both open and closed fractures, compared to FWF groups. The difference was not statistically significant apart from 12-month AOFAS score of 43C open fractures (p = 0.003) and in 43B closed fractures 3 and 6 months post-injury (p<0.001 and p<0.001, respectively). The majority of ORIF subgroups, open and closed fractures, also had shorter time to PWB, FWB, time to union, and follow-up. Statistically significant differences were seen in the following cases: ORIF-treated 43B closed fracture subgroup had shorter time to PWB and FWB (p<0.001 and p = 0.017, respectively), ORIF-treated 43C closed fractures had shorter time to union (p = 0.005). Common complications for open fractures were non-union (24%), post-traumatic arthritis (16%); for closed fractures they were post-traumatic arthritis (24%), superficial infection (21%). All occurred more frequently in FWF-treated patients.

CONCLUSION

Most ORIF-treated subgroups in either open or closed pilon fractures showed better primary and secondary outcomes than FWF-treated subgroups, yet few were statistically significant. Overall, our use of a two-staged approach involving temporary external fixation, followed with ORIF or FWF achieved low complication rates and good functional recovery.

Overview of Physical and Pharmacological Therapy in Enhancing Bone Regeneration Formation During Distraction Osteogenesis

Distraction osteogenesis (DO) is a kind of bone regeneration technology. The principle is to incise the cortical bone and apply continuous and stable distraction force to the fractured end of the cortical bone, thereby promoting the proliferation of osteoblastic cells in the tension microenvironment and stimulating new bone formation. However, the long consolidation course of DO presumably lead to several complications such as infection, fracture, scar formation, delayed union and malunion. Therefore, it is of clinical significance to reduce the long treatment duration. The current treatment strategy to promote osteogenesis in DO includes gene, growth factor, stem-cell, physical and pharmacological therapies. Among these methods, pharmacological and physical therapies are considered as safe, economical, convenience and effective. Recently, several physical and pharmacological therapies have been demonstrated with a decent ability to enhance bone regeneration during DO. In this review, we have comprehensively summarized the latest evidence for physical (Photonic, Waves, Gas, Mechanical, Electrical and Electromagnetic stimulation) and pharmacological (Bisphosphonates, Hormone, Metal compounds, Biologics, Chinese medicine, etc) therapies in DO. These evidences will bring novel and significant information for the bone healing during DO in the future.

Cyclic Distraction–Compression Dynamization Technique Enhances the Bone Formation During Distraction Osteogenesis

Background: Interfragmentary movements have benefits in the improvement of bone formation during distraction osteogenesis (DO). Although several clinical studies reported positive outcomes regarding the application of the cyclic distraction–compression (CDC) dynamization technique in cases with poor bone formation during DO, they are mostly anecdotal without a detailed description. The purpose of this study was to investigate the effectiveness and potential mechanism of different amplitudes and rates of the CDC technique on bone regeneration in a rat femur DO model.

Methods: A total of 60 adult male Sprague-Dawley rats underwent right femoral mid-diaphysis transverse osteotomy and were randomly and evenly divided into Control (no manipulation), Group1 (CDC therapy), Group2 (CDC therapy with larger amplitude), and Group3 (CDC therapy with a slower rate) after distraction. The CDC technique was performed during the middle phase of the consolidation period according to different protocols. Animals were sacrificed after 4 and 6 weeks of consolidation. The process of bone formation was monitored by digital radiographs, and the regenerate bone was evaluated by micro-computed tomography (micro-CT), biomechanical test, and histological analysis. The serum contents of hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) were measured by enzyme-linked immunosorbent assay (ELISA).

Results: Bone regeneration after the CDC technique was improved significantly during DO. The digital radiograph, micro-CT, histomorphological analysis, and biomechanical evaluation showed better effects regarding volume, continuity, and mechanical properties of the regenerate bone in Group2 and Group3 when compared to Group1. The angiogenic and osteogenic markers were more highly expressed in Group2 and Group3 than in Group1 according to the immunohistochemical analysis. As for ELISA, the serum contents of HIF-1α and VEGF were also increased after the CDC technique, especially in Group2 and Group3.

Conclusion: The CDC dynamization technique has benefits on the improvement of bone formation during DO, and the mechanism may be due to tissue hypoxia activating the HIF pathway followed by the augmentation of osteogenic–angiogenic coupling. Better outcomes may be achieved by moderately increasing the amplitude and slowing down the rate of the CDC technique.

Free flap transplantation combined with Ilizarov bone transport for the treatment of severe composite tibial and soft tissue defects

Objective

To evaluate the clinical efficacy of free flap transplantation combined with Ilizarov bone transport in the treatment of severe composite tibial and soft tissue defects.

Methods

We retrospectively analyzed the clinical data of 40 patients with severe composite tibial and soft tissue defects who underwent free flap transplantation combined with Ilizarov bone transport. The clinical efficacy was evaluated according to the following criteria: success rate of wound repair by free flap transplantation, incidence or recurrence rate of deep infection, healing rate of bone defects and external fixation index, incidence of complications, and functional score of affected extremities.

Results

All infections were generally well controlled by radical debridement and negative-pressure therapy, and all 40 patients’ wounds healed after repair and reconstruction of the tibia and soft tissues. Postoperative complications were alleviated by active treatment. The mean external fixation time was 12.83 ± 2.85 months, and the external fixation index was 1.55 m/cm. According to the Association for the Study and Application of Methods of Ilizarov (ASAMI) score, an excellent or good functional outcome was attained in 85% of patients.

Conclusion

Free flap transplantation combined with Ilizarov bone transport is an effective treatment for severe composite tibial and soft tissue defects.

[Research progress of intramedullary lengthening nail technology]

Objective

To review the research progress of intramedullary lengthening nail technology.

Methods

The foreign literature on the development history, types, advantages and disadvantages, indications and contraindications, complications, and effectiveness of intramedullary lengthening nail were reviewed and analyzed.

Results

The intramedullary lengthening nail system mainly includes mechanical type, electric motor drive type, and magnetic drive type. Compared with traditional external fixation and lengthening technology, the intramedullary lengthening nail technology has certain advantages in incidence of complications, bone healing, postoperative functional rehabilitation, incision aesthetics, convenience, and patient satisfaction. However, there are also shortcomings, such as pain, uncontrollable distraction rate, device failure, etc. In the clinical application of intramedullary lengthening nails for limb lengthening, the indications should be grasped reasonably, and the related complications should be prevented and treated.

Conclusion

Intramedullary lengthening nails provide a new option for limb lengthening, and the initial effectiveness is good. It is one of the development direction of limb lengthening technology.

Lengthening Nails for Distraction Osteogenesis: A Review of Current Practice and Presentation of Extended Indications

Purpose

Circular frames have been the gold standard of treatment for complex deformity corrections and bone loss. However, despite the success of frames, patient satisfaction has been low, and complications are frequent. Most recently, lengthening nails have been used to correct leg length discrepancies. In this article, we review the current trends in deformity correction with emphasis on bone lengthening and present our case examples on the use of lengthening nails for management of complex malunions, non-unions, and a novel use in bone transport.

Materials and methods

A nonsystematic literature review on the topic was performed. Four case examples from our institute, Brighton and Sussex University Hospitals, East Sussex, England, UK, were included.

Results

New techniques based on intramedullary bone lengthening and deformity correction are replacing the conventional external frames. Introduction of lengthening and then nailing and lengthening over a nail techniques paved the way for popularization of the more recent lengthening nails. Lengthening nails have gone through evolution from the first mechanical nails to motorized nails and more recently the magnetic lengthening nails. Two case examples demonstrate successful use of lengthening nails for management of malunion, and two case examples describe novel use in management of non-unions, including the first report in the literature of plate-assisted bone segment transport for the longest defect successfully treated using this novel technique.

Conclusion

With the significant advancement of intramedullary lengthening devices with lower complications rates and higher patient satisfaction, the era of the circular frame may be over.

How to cite this article

Barakat AH, Sayani J, O'Dowd-Booth C, et al. Lengthening Nails for Distraction Osteogenesis: A Review of Current Practice and Presentation of Extended Indications. Strategies Trauma Limb Reconstr 2020;15(1):54–61.

Treatment options for infected bone defects in the lower extremities: free vascularized fibular graft or Ilizarov bone transport?

Abstract

Objective

The objective was to explore the relative indications of free vascularized fibular graft (FVFG) and Ilizarov bone transport (IBT) in the treatment of infected bone defects of lower extremities via comparative analysis on the clinical characteristics and efficacies.

Methods

The clinical data of 66 cases with post-traumatic infected bone defects of the lower extremities who underwent FVFG (n = 23) or IBT (n = 43) from July 2014 to June 2018 were retrieved and retrospectively analyzed. Clinical characteristics, operation time, and intraoperative blood loss were statistically compared between two groups. Specifically, the clinical efficacies of two methods were statistically evaluated according to the external fixation time/index, recurrence rate of deep infection, incidence of complications, the times of reoperation, and final functional score of the affected extremities.

Results

Gender, age, cause of injury, Gustilo grade of initial injury, proportion of complicated injuries in other parts of the affected extremities, and numbers of femoral/tibial defect cases did not differ significantly between treatment groups, while infection site distribution after debridement (shaft/metaphysis) differed moderately, with metaphysis infection little more frequent in the FVFG group (P = 0.068). Femoral/tibial defect length was longer in the FVFG group (9.96 ± 2.27 vs. 8.74 ± 2.52 cm, P = 0.014). More patients in the FVFG group presented with moderate or complex wounds with soft-tissue defects. FVFG treatment required a longer surgical time (6.60 ± 1.34 vs. 3.12 ± 0.99 h) and resulted in greater intraoperative blood loss (873.91 ± 183.94 vs. 386.08 ± 131.98 ml; both P < 0.05) than the IBT group, while average follow-up time, recurrence rate of postoperative osteomyelitis, degree of bony union, and final functional scores did not differ between treatment groups. However, FVFG required a shorter external fixation time (7.04 ± 1.72 vs. 13.16 ± 2.92 months), yielded a lower external fixation index (0.73 ± 0.28 vs. 1.55 ± 0.28), and resulted in a lower incidence of postoperative complications (0.87 ± 0.76 vs. 2.21±1.78, times/case, P < 0.05). The times of reoperation in the two groups did not differ (0.78 ± 0.60 vs. 0.98 ± 0.99 times/case, P = 0.615).

Conclusion

Both FVFG and IBT are effective methods for repairing and reconstructing infected bone defects of the lower extremities, with unique advantages and limitations. Generally, FVFG is recommended for patients with soft tissue defects, bone defects adjacent to joints, large bone defects (particularly monocortical defects), and those who can tolerate microsurgery.

Managing bone loss in open fractures

Segmental bone loss continues to pose substantial clinical and technical challenges to orthopaedic surgeons. While several surgical options exist for the treatment of these complex patients, there is not a clear consensus or specific guidelines on the optimal management of these injuries as a whole. Many factors must be taken into consideration when planning surgery for these individuals. In order for these techniques to yield optimal results, each injury must be approached in a step-wise and multidisciplinary fashion to ensure that care is taken in bone and wound bed preparation, that soft tissues are healthy and free of contaminants, and that the patient's medical condition has been optimized. Through this article, we will answer relevant questions and discuss common obstacles and challenges encountered with these complex injuries. We will also review the many treatment options available or in development to address this problem.

Limb lengthening history, evolution, complications and current concepts

Limb lengthening continues to be a real challenge to both the patient and the orthopaedic surgeon. Although it is not a difficult operative problem, there is a long and exhausting postoperative commitment which can jeopardize early good results. I aim to review the history, evolution, biology, complications and current concepts of limb lengthening. Ilizarov's innovative procedure using distraction histeogenesis is the mainstay of all newly developing methods of treatment. The method of fixation is evolving rapidly from unilateral external fixator to ring fixator, computer assisted and finally lengthening intramedullary nails. The newly manufactured nails avoid many of the drawbacks of external fixation but they have their own complications. In general, the indications for limb lengthening are controversial. The indications have been extended from lower limb length inequality to upper extremity lengthening, including humeral, forearm and phalangeal lengthening. A wide range in frequency of complications is recorded in the English literature, which may reach up to 100% of cases treated. With developing experience, cosmetic lengthening has become possible using external or internal lengthening devices with an acceptable rate of problems.Level of evidence: V.

Bone Transport for Treatment of Traumatic Composite Tibial Bone and Soft Tissue Defects: Any Specific Needs besides the Ilizarov Technique?

Objective

To evaluate the surgical efficacy of bone transport (Ilizarov technique) plus “shortening-lengthening,” “flap surgery,” and “open bone transport” as individualized treatments for traumatic composite tibial bone and soft tissue defects.

Methods

We retrospectively analyzed sixty-eight cases (mean age: 35.69 years, (range, 16–65)) treated from July 2014 to June 2017, including 29 middle, 18 distal, and 21 proximal tibial bone defects (4–18 cm, mean: 7.97 cm) with soft tissue defects (2.5 cm × 4.0 cm to 30.0 cm × 35.0 cm after debridement). We adopted the bone transport external fixator to fix the fracture after debriding the defect parts. In the meantime, we adopted the “shortening-lengthening technique,” “flap surgery,” and “open bone transport” as individualized treatment based on the location, range, and severity of the composite tibial bone and soft tissue defects. Postoperative follow-up was carried out. Surgical efficacy was assessed based on (1) wound healing; (2) bone defect healing rate; (3) external fixation time and index; (4) incidence/recurrence of deep infection; (5) postoperative complications; and (6) Association for the Study and Application of the Methods of Ilizarov (ASAMI) score.

Results

The mean duration from injury to reconstruction was 22 days (4–80 d), and the mean postoperative follow-up period was 30.8 months (18–54 m). After the repair and reconstruction, 2 open bone transport patients required infected bone removal first before continuing the bone transport treatment. No deep infection (osteomyelitis) occurred or recurred in the remaining patients, and no secondary debridement was required. Some patients had complications after surgery. All the postoperative complications, including flap venous crisis, nail channel reaction, bone nonunion, mechanical axis deviation, and refracture, were improved or alleviated. External fixation time was 12.5 ± 3.41 months, and the index was 1.63 ± 0.44. According to the ASAMI score, 76.47% of the outcomes were good/excellent.

Conclusion

The Ilizarov technique yields satisfactory efficacy for composite tibial bone and soft tissue defects when combined with “shortening-lengthening technique,” “flap surgery,” and “open bone transport” with appropriate individualized treatment strategies.

[Effect of "accordion" technique on bone consolidation during distraction osteogenesis]

Objective

To investigate the effect, right timing, and mechanism of "accordion" technique on bone regeneration in rat distraction osteogenesis model.

Methods

Fifty-four 12-week-old male Sprague Dawley rats underwent right tibial distraction osteogenesis procedure. After a 5-day latency, the distraction was performed for 7 days followed by 6-week consolidation. All animals were randomly divided into 4 groups based on different periods of "accordion" maneuvers in consolidation phase: control group ( n=18) with no manipulation, and three experimental groups including early-phase group ( n=18), mid-phase group ( n=12), and late-phase group ( n=6) with "accordion" maneuvers applied at 1, 3, and 5 weeks, respectively. The duration of the "accordion" maneuver was 7 days consisting of a 3.5-day compression and 3.5-day distraction. Rats in control group and early-phase group were sacrificed at 2, 4, and 6 weeks of the consolidation phase; rats in mid-phase group were sacrificed at 4 and 6 weeks of the consolidation phase; and rats in late-phase group were sacrificed at 6 weeks of the consolidation phase. Bilateral tibias from 6 rats in each group at each time point were obtained. Callus formation was monitored by X-ray radiography every week; new bone was reconstructed by Micro-CT three-dimensional reconstruction. The change of bone structure was evaluated, and parameters containing bone volume (BV)/tissue volume (TV) ratio (BV/TV) and bone mineral density (BMD) in three thresholds (158-211, 211-1 000, 158-1 000) were recorded and calculated at 6 weeks. Mechanical test consisting of ultimate load, modulus of elasticity, and energy to failure was performed. Histological analysis, such as Von Kossa staining, Safranin O staining, and HE staining, was done. Immunohistochemical staining using markers of osterix (OSX), osteocalcin (OCN), and vascular endothelial growth factor (VEGF) was analyzed.

Results

Images of X-ray showed that callus formation increased significantly in the mid-phase group. Micro-CT three-dimensional reconstruction demonstrated the mid-phase group owned fastest reconstructed speed among 4 groups, the cortical bone was continual at 6 weeks. At 6 weeks, the BMD and BV/TV in thresholds 158-1 000 and 211-1 000 in mid-phase group were higher than those in other groups. The results of mechanical test showed that ultimate load, modulus of elasticity, and energy to failure in mid-phase group were significantly higher than those in other groups ( P<0.05). Histological testing showed that the continuity of bone marrow cavity in mid-phase group was evident at 6 weeks after distraction. Immunohistochemical analyses confirmed the expression levels of osteogenesis (OCN, OSX) and angiogenesis (VEGF) elevated remarkably and then returned to normal in mid-phase group.

Conclusion

The "accordion" technique is beneficial for new callus formation in distraction area. Applying the maneuver during the middle phase of the consolidation period was effective to accelerate new bone formation in rat distraction osteogenesis model.

Novel Surgical Approach to Segmental Bone Transport Using a Magnetic Intramedullary Limb Lengthening System

Posttraumatic bone defects (BDs) remain a difficult complication for orthopaedic surgeons. Surgical goals in these reconstructive cases are to create stable limb fixation, maintain limb length, and provide adequate soft-tissue coverage. Historically, surgical approaches in these cases have required the use of an external fixator, which is associated with several postoperative complications. A plate-assisted bone segment transport (PABST) technique using a magnetic limb lengthening system eliminates the need for an external fixator and is effective for these reconstructive cases. A 51-year-old male patient presented as a category I trauma after a motorcycle collision. Osseous injury was defined as Gustilo-Anderson type IIIB distal tibia and fibula fracture (AO 42-C2). After fixation failure, the PABST technique was performed using a magnetic intramedullary limb lengthening system. Radiographic union was achieved 18 months postoperatively. This innovative surgical technique is effective in treating posttraumatic BDs without the need for limb shortening or the use of an external fixator. PABST has the potential to decrease postoperative complications in BD reconstructive cases using all-internal technology designed for limb lengthening. PABST, in this instance, uses a magnetic intramedullary nail that is controlled with a hand-held external remote to allow for precise, adjustable, and bidirectional bone segment transport.

Strategies of enhancing bone regenerate formation in distraction osteogenesis

Distraction osteogenesis (DO) is a commonly used technique in multiple orthopedic sub-specialties, including trauma, oncology and pediatrics. This technique aims to produce new bone formation in the distraction gap in a controlled manner. The issue with this technique has been the high risk of complications, one of which is poor regenerate formation during the distraction process. Although several factors (including patient and operative factors) and techniques (including surgical, mechanical and pharmacological) have been described to ensure successful regenerate formation during the process of DO, these factors are sometimes difficult to control clinically. Our aim from this review is to highlight the different factors that affect DO, modalities to assess the regenerate and review treatment options for poor regenerate in the distraction gap. In addition, we propose a management protocol derived from the available literature that can be used to facilitate the management of inadequate regenerate formation.

Femoral nonunion with segmental bone defect treated by distraction osteogenesis with monolateral external fixation

BACKGROUND

Currently, the common treatment for femoral nonunion with large segmental bone defect is difficult and complex. The effective surgical methods are rare, include vascularized bone grafting, Masquelet technique and Ilizarov distraction osteogenesis. The objective of this study is to investigate the outcomes of segmental femoral defects treated with monolateral external fixation using the distraction osteogenesis.

METHODS

We retrospectively analyzed patients with femoral nonunion with segmental bone defects (> 6 cm) between January 2010 and January 2014 in our single trauma center. All patients were treated by distraction osteogenesis with monolateral external fixation. All surgeries were performed by the same surgeon. Bone union, duration of distraction osteogenesis in days, time to consolidation in months, external fixation index (EFI), complications, and additional surgical interventions were recorded postoperatively. The modified Application of Methods of Illizarov (ASAMI) criteria were used to evaluate the operative effectiveness.

RESULTS

Forty-one patients were enrolled in this study for analysis. The length of the bone defect ranged from 6 to 17 cm. All patients eventually achieved healing, and no patient experienced recurrence of infection or newly developed infection. The average time needed for healing was 13 months. In terms of the incidence of complications, 3 cases axial deviations, 5 cases docking site nonunion, 23 cases pin-tract infection, 14 cases knee joint stiffness or their joint mobility declined, 2 cases osteogenesis insufficient in the distraction area,1 case refracture, and 2 cases loose external fixation pins. In terms of the evaluations of fracture healing and function, 30 patients excellent, 6 patients good, 5 patients fair, and 0 patient poor. In terms of postoperative function evaluations, 21 patients excellent, 9 patients good, 7 patients fair, and 4 patients poor.

CONCLUSION

For patients with femoral nonunion with large segmental bone defects, the monolateral external fixation can provide effective stability, improve compliance, and reduce complications.

Accordion technique combined with minimally invasive percutaneous decortication for the treatment of bone non-union

BACKGROUND

A variety of approaches have been used to treat oligotrophic or atrophic non-union. Conventional methods are often associated with great operative trauma, increased blood loss, a risk of re-infection, higher medical costs, and complications at the donor site. This study aimed to assess the clinical efficacy of the accordion technique combined with Minimally Invasive Percutaneous Decortication (MIPD) for these types of bone non-union.

METHODS

From January 2010 to December 2015, 20 patients with long bone aseptic non-unions of the lower extremities without bone defects who were treated with the accordion technique combined with MIPD. The limb-length discrepancy (LLD) was less than 2cm in all patients. None of the patients received autogenous bone grafts during follow-up. All surgeries were performed by the same surgeon, and the modified Application of methods of Ilizarov (ASAMI) criteria were used to evaluate the operative effectiveness.

RESULTS

A total of 20 patients were included in this study, and 1 patient was lost during follow-up. Fifteen of these patients presented with oligotrophic non-unions, and 5 patients presented with atrophic non-unions. The average follow-up period in these patients was 12.1 months (range: 8-42 months). The alternative compression and distraction procedure was repeated 1-3 times. Blood loss was 30 to 250ml during surgery. Ultimately, bone union was achieved in 19 patients and failed in 1 patient. The fractures healed within 4-8 months (average time: 5.9 months), and fracture healing was considered excellent in 19 patients and poor in 1 patient. Postoperative function was evaluated as excellent in 9 patients, good in 6 patients, fair in 4 patients, and poor in 1 patient.

CONCLUSION

The accordion technique combined with MIPD, which is a simple, minimally invasive procedure that does not require autologous bone grafting, resulted in a high bone union rate and good postoperative function.

Can Spatiotemporal Fluoride (18F-) Uptake be Used to Assess Bone Formation in the Tibia? A Longitudinal Study Using PET/CT

BACKGROUND

When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride (¹⁸F^-) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons. Absorbed on the bone surface from blood flow, ¹⁸F^- attaches to the osteoblasts in cancellous bone and acts as a pharmacokinetic agent, which reflects the local physiologic activity of bone. This is important because it shows bone formation indicating that the bone is healing or no bone formation indicating no healing. As ¹⁸F^- is extracted from blood in proportion to blood flow and bone formation, it thus enables determination of bone healing progress.

QUESTIONS/PURPOSES

The primary objective of this study was to determine whether videos showing the spatiotemporal uptake of ¹⁸F^- via PET bone scans could show problematic bone healing in patients with complex tibia conditions. A secondary objective was to determine if semiquantification of radionuclide uptake was consistent with bone healing.

METHODS

This study investigated measurements of tibia bone formation in patients with complex fractures, osteomyelitis, and osteotomies treated with a Taylor Spatial Frame^TM (TSF) by comparing clinical healing progress with spatiotemporal fluoride (¹⁸F^-) uptake and the semiquantitative standardized uptake value (SUV). This procedure included static and dynamic image acquisition. For intrapatient volumes acquired at different times, the CT and PET data were spatially registered to bring the ends of the bones that were supposed to heal into alignment. To qualitatively observe how and where bone formation was occurring, time-sequenced volumes were reconstructed and viewed as a video. To semiquantify the uptake, the mean and maximum SUVs (SUVmean, SUVmax) were calculated for the ends of the bones that were supposed to heal and for normal bone, using a spherical volume of interest drawn on the registered volumes. To make the semiquantitative data comparable for all patients with multiple examinations, the SUVmean and SUVmax difference per day (SUVmeanDPD and SUVmaxDPD) between the first PET/CT scan and each subsequent one was calculated. Indicators of poor healing progress were (1) uneven distribution of the radionuclide uptake between ends of the bones that were supposed to heal as seen in the video or, (2) low absolute magnitude of the SUV difference data. Twenty-four patients treated between October 2013 and April 2015 with a TSF gave informed consent to be examined with ¹⁸F^- PET/CT bone scans. Twenty-two patients successfully completed treatment, one of whom had only one PET/CT scan.

RESULTS

Observation of ¹⁸F^- uptake was able to identify three patients whose healing progress was poor, indicated by uneven distribution of radionuclide uptake across the ends of the bones that were supposed to heal. An absolute magnitude of the SUVmaxDPD of 0.18 or greater indicated good bone formation progress. This was verified in 10 patients by the days between the operation to attach and to remove the TSF being less than 250 days, whereas other SUVmaxDPD values were ambiguous, with 11 patients achieving successful completion.

CONCLUSIONS

Observation of the spatiotemporal uptake of ¹⁸F^- appears to be a promising method to enable the clinician to assess the progress of bone formation in different parts of the bone. Bone uptake which is uneven across the ends of bone that were supposed to heal or very low bone uptake might indicate impaired bone healing where early intervention may then be needed. However, semiquantification of ¹⁸F^- uptake (SUVmaxDPD), SUVmeanDPD) was ambiguous in showing consistency with the bone-healing progress.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Lengthening of the humerus with intramedullary lengthening nails-preliminary report

Distraction osteogenesis of the humerus with fully implantable lengthening is now possible since the diameter of the available nails was reduced to 10 mm and below. We report on the first intramedullary lengthening cases of the humerus with two different lengthening devices (FITBONE and PRECICE). Two different approaches and implantation techniques were used. We retrospectively reviewed clinical and radiographic data and pointed out results, pitfalls and complications of the procedure. Four adult patients with relevant length discrepancy of the humerus were treated with fully implantable systems in two centers between 2012 and 2015. Three patients were treated with FITBONE by an antegrade approach; one patient had lengthening with a PRECICE and a retrograde approach. Average nail lengthening was 55 mm (40–65 mm), and the average duration of lengthening was 70 days (52–95 days). The average distraction index was 0.72 mm/day (range 0.4–1.0 mm/day) or 12.5 days/cm (range 8.0–16.2 days/cm). The average consolidation index was 33.6 days/cm (range 25–45 days/cm). There was an implant failure (arrest) with the PRECICE. After consolidation and exchange with a technically improved implant, the course of treatment was uneventful. In patients with antegrade lengthening shoulder abduction decreased, and in the patient with the retrograde approach it improved but elbow extension decreased marginally. Reduced motion of the adjacent joints can be a major problem in intramedullary lengthening of the humerus. This first case series in the field of a rare indication suggests that lengthening of the humerus by fully implantable lengthening nails might be a valuable alternative to lengthening with external fixation. Main advantage of the PRECICE technology is the possible shortening in-between of lengthening.