Clinical Results of Decortication with Bone Grafting Method versus Extracorporeal Shock Wave Treatment in Long-Bone Pseudoarthrosis

Background

Long-bone fractures of the lower extremity are injuries that cause significant physical problems [1]. These fractures usually occur after high-energy traumas and lead to important movement disorders, malunion, delayed union, and non-union [2]. Non-union of fractures causes chronic pain, functional and psychological disorders, impairs quality of life, and increases treatment costs [3]; 9–10% of lower-extremity fractures result in non-union. In open fractures, depending on the severity of the fractures type, non-union rates can reach 50% [4,5]. The treatment of pseudoarthrosis is mechanical stabilization and biological stimulation [6].

Debridement of the necrotic tissue and removing devitalized bone fragments from the pseudoarthrosis site and inserting autologous cancellous bone grafting between the fracture ends and fixation is considered the criterion standard treatment of pseudoarthrosis [7,8]. This treatment is still considered the first option for treating pseudoarthrosis, and success rates of 85–95% are reported [7]. However, up to 8.6% of patients treated with this method have major complications (eg, infection, prolonged wound drainage, hematomas, advanced surgery, and permanent pain) and up to 20% have minor complications (eg, superficial wound infection, temporary loss of sensation, mild pain) [9]. Non-union and delayed union fractures are treated with surgical stabilization with or without bone graft reinforcement. High-energy focused extracorporal shock wave therapy (ESWT), on the other hand, has emerged as a non-invasive, cost-effective, and similarly successful method [10].

ESWT is a non-invasive outpatient procedure to biologically stimulate fracture healing in non-unions [11]. For the last 30 years, ESWT has been used in orthopedics and traumatology for the treatment of plantar fasciitis, lateral humeral epicondylitis, non-union and delayed union of fractures, calcified shoulder tendinitis, aseptic necrosis of the femoral head, achilles tendinitis, patellar tendinitis, and osteochondritis dissecans [12]. Since Valchanou and Michailov reported a success rate of 85% in the treatment of pseudoarthrosis in 1991, ESWT has been used widely in orthopedics and traumatology for treatment of fractures and pseudoarthrosis [13].

Until the present work, no study had compared both methods in the literature.Therefore, a comparative study was planned with the hypothesis that ESWT could be an alternative to traditional surgical methods in the treatment of biologically active pseudoarthrosis of the lower-extremity long bone.

Material and Methods

DECORTICATION AND AUTOLOGOUS BONE GRAFTING SURGICAL TECHNIQUE:

In decortication and bone grafting, after the pseudoarthrosis field is opened, the fibrotic and necrotic bone tissues on the fracture line are removed, then the sclerotic bones with no nutrition at the fracture ends are refreshed until punctate bleeding spots are seen.Then, the iliac crest is opened and grafts obtained from the spongious portion are placed in the fracture line and are stabilized with appropriate fixation material. After stabilization, the periosteum is closed, covering the graft, the tissues are closed in standard fashion, and the operation is completed. In patients undergoing decortication and iliac bone grafting for tibial pseudoarthrosis, an additional fibula osteotomy is also performed (Figures 1, 2).

ESWT APPLICATION:

All patients were treated under either general or regional anesthesia. ESWT was performed with the Siemens brand device. Non-union was visualized by X-ray and the level was marked on the skin. Anatomical structures such as arteries, veins and nerves were spared by the shock waves. All patients received high-energy ESWT (0.6 mJ/mm2) with 3000 impulses administered to 3–4 different foci in 1 session. Cold therapy was applied to the procedure site in all patients within the first 24 hours (Figures 3, 4).

EVALUATION:

The mean intervention times was the same in both groups, the mean time to union was 6.6 months in the decortication and bone grafting group and 7.3 months in the ESWT group, the mean follow-up period was 20.9 months in the decortication and bone grafting group and 29.6 months in ESWT group, and union rates were evaluated. After the intervention, physical examination and two-view radiographic union findings were evaluated monthly in the first 3 months, then 3 and 6 months later, then annually. Painless palpation and weight bearing, no crepitations on the fracture line, no pathological movements, and the presence of calluses in 3 of the 4 bone cortexes in two-view radiographs were considered supportive of union after this evaluation. The Cech and Weber vascular-avascular pseudoarthrosis classification was used to identify the type of the pseudoarthrosis (Table 1) [14]. The Stewart-Hundley and Hammer classification was used to evaluate clinical and radiological healing [15].

STATISTICAL ANALYSES:

Among the features assessed, the defining statistics of continuous variables were expressed as means, standard deviations, and minimum and maximum values, and the categorical variables were expressed as numbers and percentages. For continuous variables, the t test was used to compare the group mean values. To establish the association between the variables, Pearson correlation coefficients were calculated individually for the groups. To compare the rates of the categorical variables, the Z test and the Fisher exact probability tests were used. The level of statistical significance was set at 5% and the SPSS and MINITAB statistical package programs were used for calculations.

Results

The mean age of the patients was 44.1 years (range, 24–69 years) in the decortication and bone grafting group and 43.8 (range, 21–62) in the ESWT group. There were 26 males and 6 females in the decortication and bone grafting groups, and 28 males and 8 females in the ESWT group. There was no statistically significant difference between the 2 groups in terms of age and sex (P=0.802). In respect to the fractured extremity, 40 fractures (26 right and 14 left) were in the femur and 28 were in the tibia (12 right and 16 left). Table 2 shows the distribution and number of fractured bones, the presence of open fractures, the number of segmental fractures, the presence of additional fractures, accompanying vascular damage, the reduction status, prevalence of smoking, presence of comorbidities causing fracture delay, and history of infections.

According to the Cech Weber pseudoarthrosis classification, 4 fractures were classified as elephant’s foot, 20 fractures as horse’s hoof, and 44 fractures as oligotrophic pseudoarthrosis. The classification of patients according to the Cech and Weber vascular pseudoarthrosis classification is given in Table 1.

After the mean follow-up period, bone union had occurred in all 32 patients (100%) in the decortication and bone grafting group and in 28 (78%) of 36 patients in the ESWT group (P=0.023). There was no statistically significant difference between the mean intervention times, union times, and follow-up times between the 2 groups (P=0.985, P=0.251, P=0.359) (Table 3).

In respect to the fixation material used, 38 fractures were fixated with intramedullary nail and 22 fractures were fixated with external fixators. Infections developed in 12 fractures that were initially being treated with the internal fixation method. The internal stabilization was ended and external fixation was started. Eight fractures were treated with plate osteosynthesis fixation. The stabilization materials used in the initial surgeries are listed in Table 4.

The etiology of the fractures was high-energy trauma in all patients. The etiologic causes are listed in Table 5. In the decortication and bone grafting group, no complications such as wound problem or vascular-nerve injury were observed.

Discussion

The causes of delayed union or non-union include passage of soft tissue between fracture fragments, the severity of the trauma, bone loss, inadequate fixation, early mobilization, infections, presence of concomitant diseases, nonsteroidal anti-inflammatory drugs use, vitamin or protein deficiencies, hormonal disorders, presence of osteoporosis, age, and smoking [16].

A precise definition of non-union is difficult. Although it varies among sources, situations where clinical and radiological union does not occur in 6 months or one in which there is a failure of progression towards union over the previous 3 months are regarded as pseudoarthrosis [8,14,15]. However, Cech and Weber have stated that all cases believed to have no potential to heal without further intervention should be regarded as pseudoarthrosis independent of duration [17,18]. In our study, it was observed that intervention was done if pseudoarthrosis signs persisted for an average of 8.7 months in the decortication and bone grafting group and 8.6 months in the ESWT group.

Femoral and tibial fractures are seen in the young, active age group with rates of 75% and occur more frequently after high-energy traumas (eg, traffic accident, falling from height) [19]. Out of 66 patients enrolled in the study, 52 were male and 14 were female, 56 patients were 50 years old or younger, and the mean age was 43.9 years. In addition, the etiology was high-energy trauma in all patients. With these features, our cases are consistent with studies in the literature in respect to average age, sex distribution, and etiology.

For the last 30 years, ESWT has been used in orthopedics and traumatology for treatment of plantar fasciitis, lateral humeral epicondylitis, non-union and delayed union of fractures, calcified shoulder tendinitis, aseptic necrosis of the femoral head, Achilles tendinitis, patellar tendinitis, and osteochondritis dissecans [12]. Since Valchanou and Michailov reported success rates of 85% in the treatment of pseudoarthrosis in 1991, ESWT has been used widely in orthopedics and traumatology [13].

Schoellner performed ESWT under regional anesthesia in 43 patients 9 months after surgery and reported that the bone union rate after an average of 4–6 months was 75% [20]. Alvarez performed ESWT in 34 fractures in 32 metatarsal non-union patients at an average of 23 weeks after injury and reported the bone union rate as 89% after an average follow-up of 1 year [21]. Josef et al performed ESWT in 17 long-bone (tibia-femur) pseudoarthrosis patients and had a bone union rate of 64.7% [22]. Zelle reported had a 76% bone union rate, which was higher in the hypertrophic pseudoarthrosis in the 10 studies including 924 delayed unions treated with ESWT they reviewed to assess the efficacy of ESWT [23]. In our cases, we performed ESWT in single doses on 36 fractures (22 femurs, 14 tibias) after an average of 8.6 months and our bone union rate was 78% after an average of 7.3 months. When compared with rates in the literature, our union rates are similar, but our time to union was slightly longer. We attributed this to our small number of cases and the presence of fractures of lower-extremity long bones, where healing is difficult, whereas studies in the literature included fractures of nearly every bone in various regions.

Debridement of the necrotic tissue and removing devitalized bone fragments from the pseudoarthrosis site and inserting spongious bone between the fracture ends and fixation is considered the criterion standard in the treatment of pseudoarthrosis, and success rates of 85–95% are reported [7,8].

Niedzwiedzki et al mixed the graft obtained from the iliac crest with heparin and injected it into the fracture line in a case series of 92 patients. In these patients, the mean age was 36.6 years, 24 of these were new fractures, 42 were delayed unions, and 30 were pseudoarthrosis. It was reported that bone union was achieved in an average of 2.8, 3.2 and 3.4 months respectively in all of these patients [24]. The same authors reported that they treated 17 femoral or tibial pseudoarthrosis cases (mean age 48 years) with reamed locking intramedullary nails; union was achieved in 15 cases and the spreading of the bone graft on the fracture line during reaming positively affected the bone union [25]. Pawel et al performed decortication and iliac bone grafting in 56 patients with long-bone pseudoarthrosis; union was achieved in 51 cases and the time to bone union was 5 months [26]. In our case series, 32 fractures (18 femurs, 14 tibias) were present in the decortication and bone grafting group. Procedures were performed an average of 8.7 months later and union was achieved in all patients after an average of 6.6 months. Our results are consistent with the literature in respect to union outcomes and time to achieve union.

When we compared the groups with each other in the aspects of average age, sex distribution, extremity involvement, fracture etiology, fracture type (open or closed), presence of segmental fractures, presence of additional fractures, postoperative fracture reduction status, fixation material used, and the mean intervention times, the results were statistically similar.

Although factors that cause delays in union, such as high rates of fragmentation at the fracture line, a high number of patients with vascular injuries, a high number of smokers, a high number of patients with additional fractures, and a history of infection, were more common in the decortication and bone grafting group, a statistically significant difference was not identified between groups. Comorbidities (eg, protein deficiencies, diabetes mellitus, steroid use, osteoporosis) were less frequent in the ESWT group than in the decortication and bone grafting group, but the difference was not statistically significant. We believe that the differences mentioned would affect the results but did not reflect on the statistics because the patient number in the sample was low. Our mean follow-up period was longer in the ESWT group and the mean duration of bone union was lower in the decortication and bone grafting group, but these differences were not statistically significant.

While union was achieved in all of the 32 fractures in the decortication and bone grafting group, union was only achieved in 28 of the 36 patients in the ESWT group (P=0.023, which is statistically significant).

This study has some limitations. First of all, the number of cases was small. However, the choice of 2 different comparative treatments and the use of the same ESWT device in a single center are important factors in terms of the number of cases. Another limitation of the study is that it was retrospective. In addition, we did not perform cost analysis of the 2 treatment methods.

Conclusions

We believe that decortication and bone grafting is the first choice and best treatment method for pseudoarthrosis surgery, esespecially in defective fractures, atrophic pseudoarthrosis, inadequate fixation, and if there are reduction losses. Extracorporeal shock wave treatment can be used in non-defective fractures, in situations with adequate fixation and no reduction loss, and in all kinds of early fractures that are believed to have no potential to heal. ESWT should be considered the first option in the treatment of pseudoarthrosis as it is a non-invasive method and also provides good union rates. In patients that do not heal with this method, decortication and bone grafting remains to the criterion standard.