Orthopedics

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Evaluation of the Calori et al Nonunion Scoring System in a Retrospective Case Series

Lutf A. Abumunaser, MD, FACARTZ; Mohammed J. Al-Sayyad, MD, FRCSC

Abstract

Nonunion is one of the most challenging orthopedic complications. Although current definitions are accepted, they fail to provide a satisfactory definition of nonunion. Different classifications for nonunion have been described, but these systems did not take all required factors and requirements of nonunion treatment into account for fracture healing. Calori et al recently developed a new comprehensive nonunion scoring system, which takes into account the whole fracture personality that influences nonunion. The aim of this study is to evaluate the validity of the Calori et al system in the treatment of nonunions. We retrospectively reviewed our database for lower extremity nonunion from 2002 to 2009. The demographic and clinical data, laboratory, and radiological investigations were collected from medical records and phone interviews. Forty cases were identified: 32 men and 8 women. Mean patient age was 39.75 years (range, 6-102 years). Seventeen were femoral and 23 were tibial. Our patients were divided into 3 groups according to the database treatment: group 1 standard treatment (3 patients), group 2 specialized care and treatment (33 patients), group 3 amputations (4 patients). If we apply the recommended management by Calori et al to our patients, they will be divided into groups similar to the database treatments. Statistical analysis showed significant correlation between our actual treatment and those recommended by the Calori system where the P value was <.01. We concluded that the Calori et al scoring system could be valid as a guideline for lower extremity nonunion treatment.

The healing of a fracture is a unique phenomenon that currently has a full and logical explanation based on mechanical and biological factors that are linked together in a coherent fashion. Nonunion of the fracture is defined as the cessation of all reparative healing processes without bone union.1,2 Unless there is bone loss, nonunion is declared 6 months following the fracture.3 However, nonunion can be described as the absence of progressive repair radiologically 6 months following the fracture.4 Even these current accepted definitions fail to provide a satisfactory definition and have hindered research into nonunion for many years, as no 2 cases of nonunion are alike.5

Different classifications of nonunion have been described. Weber and Cech6 developed a system based on radiological appraisal. Ilizarov developed a system based on bone morphology (lax, stiff, and stiff with angular deformity).7 Paley described a useful system for reconstruction according to clinical mobility (stiff, <5°; partially mobile, 5°-20°; flail, >20°).8 But all these systems do not take the whole fracture situation into account and do not meet the current nonunion treatment requirement. Calori et al9 recently developed a new comprehensive classification system, called the Nonunion Scoring System, which takes into account the fracture personality (bone, soft tissue, patient, and environmental factors) that influence the fracture to progress to a nonunion. The purpose of this study is to evaluate the value of the new nonunion scoring system for the management of nonunion in a retrospective case series.

We reviewed our prospective nonunion database for lower extremity nonunion from 2002 to 2009 in a tertiary care center. The demographic data, detailed history and clinical examination, laboratory investigation including complete blood count, erythrocyte sedimentation rate, and C-reactive protein, and relevant radiological investigation were all collected from medical records manually and digitally, and phone interviews. The new Calori et al9 nonunion scoring system was used to score our patients as shown in Tables 1 and 2. The total score should then be multiplied by 2, so a score between 0 and 25 would be considered a straightforward nonunion and should respond well to standard treatment. Scores between 26 and 50 require more specialized care.…

Abstract

Nonunion is one of the most challenging orthopedic complications. Although current definitions are accepted, they fail to provide a satisfactory definition of nonunion. Different classifications for nonunion have been described, but these systems did not take all required factors and requirements of nonunion treatment into account for fracture healing. Calori et al recently developed a new comprehensive nonunion scoring system, which takes into account the whole fracture personality that influences nonunion. The aim of this study is to evaluate the validity of the Calori et al system in the treatment of nonunions. We retrospectively reviewed our database for lower extremity nonunion from 2002 to 2009. The demographic and clinical data, laboratory, and radiological investigations were collected from medical records and phone interviews. Forty cases were identified: 32 men and 8 women. Mean patient age was 39.75 years (range, 6-102 years). Seventeen were femoral and 23 were tibial. Our patients were divided into 3 groups according to the database treatment: group 1 standard treatment (3 patients), group 2 specialized care and treatment (33 patients), group 3 amputations (4 patients). If we apply the recommended management by Calori et al to our patients, they will be divided into groups similar to the database treatments. Statistical analysis showed significant correlation between our actual treatment and those recommended by the Calori system where the P value was <.01. We concluded that the Calori et al scoring system could be valid as a guideline for lower extremity nonunion treatment.

The healing of a fracture is a unique phenomenon that currently has a full and logical explanation based on mechanical and biological factors that are linked together in a coherent fashion. Nonunion of the fracture is defined as the cessation of all reparative healing processes without bone union.1,2 Unless there is bone loss, nonunion is declared 6 months following the fracture.3 However, nonunion can be described as the absence of progressive repair radiologically 6 months following the fracture.4 Even these current accepted definitions fail to provide a satisfactory definition and have hindered research into nonunion for many years, as no 2 cases of nonunion are alike.5

Different classifications of nonunion have been described. Weber and Cech6 developed a system based on radiological appraisal. Ilizarov developed a system based on bone morphology (lax, stiff, and stiff with angular deformity).7 Paley described a useful system for reconstruction according to clinical mobility (stiff, <5°; partially mobile, 5°-20°; flail, >20°).8 But all these systems do not take the whole fracture situation into account and do not meet the current nonunion treatment requirement. Calori et al9 recently developed a new comprehensive classification system, called the Nonunion Scoring System, which takes into account the fracture personality (bone, soft tissue, patient, and environmental factors) that influence the fracture to progress to a nonunion. The purpose of this study is to evaluate the value of the new nonunion scoring system for the management of nonunion in a retrospective case series.

Materials and Methods

We reviewed our prospective nonunion database for lower extremity nonunion from 2002 to 2009 in a tertiary care center. The demographic data, detailed history and clinical examination, laboratory investigation including complete blood count, erythrocyte sedimentation rate, and C-reactive protein, and relevant radiological investigation were all collected from medical records manually and digitally, and phone interviews. The new Calori et al9 nonunion scoring system was used to score our patients as shown in Tables 1 and 2. The total score should then be multiplied by 2, so a score between 0 and 25 would be considered a straightforward nonunion and should respond well to standard treatment. Scores between 26 and 50 require more specialized care. Patients with a score between 51 and 75 need more specialized care and treatment. In patients with scores >75, primary amputation may be considered.9

Table


Table


We identified 40 cases with nonunion of the lower extremity. The distribution of the patient database according to the nonunion scoring system is illustrated in Table 3. Our patients were grouped into 3 categories instead of 4 as stated in the Calori et al9 system, because in this classification, no clear differentiation exists between the second (score of 26-50) and 3rd (score 51-75) categories as per the Calori et al9 treatment protocol. We modified the Calori et al9 categories so that a category 1 score of 0 to 25 should respond to standard treatment (such as plating, intramedullary nailing, and iliac crest bone grafting), a Category 2 score of 26 to 75 is to be dealt with by specialized treatment and care (such as circular external fixation, vascularized bone graft, biological bone stimulation protein, bone morphogenic protein, myocutaneous flap, and bone transport), and a Category 3 score of >75 is when primary amputation may be indicated.

Table

Statistical analysis was performed using SPSS version 17 (IBM, Somers, NY) using the Chi square fit test so that the actual management follows that recommended by the Calori et al9 score, with the significance at P<.01. Additionally, the symmetry between the actual management and that recommended by the Calori et al9 score was tested using the contingency coefficient with the significance at P<.01.

Results

In our study, 40 patients with nonunion of the lower extremities were included. Thirty-two (80%) were men and 8 (20%) were women. The mean age ± standard deviation was 39.75±19.55 years (range 6-102 years). Seventeen were (42.5%) nonunion femur patients and 23 (57.5%) were nonunion tibial patients.

Our patients were divided, according to the database treatment, into 3 groups as follows: 3 patients in group 1 underwent standard treatment, 33 patients in group 2 received specialized care and treatment, and 4 patients in group 3 underwent amputations. Patient information is summarized in Table 4.

Table

If we apply the recommended management according to the Calori et al9 scoring system to our patients, they will also be divided into 3 groups. In the first group, 3 patients received standard treatment. In the second, 33 patients were managed with specialized care and treatment, and in the third, 4 patients underwent amputations (Table 5).

Table

Statistically, a significant correlation exists between our actual management and those recommended by the Calori et al9 system. Chi square fit testing that the actual management follows as recommended by the Calori et al9 score showed a Chi square value of 56.198 with 4° of freedom and P<.0001. Significant symmetry between the actual management and that recommended by the Calori et al9 score were also identified using the contingency coefficient (with a value of 0.764) and P<.0001.

Discussion

As fracture repair is a continuous process, many biological and/or mechanical factors play a significant role in the fracture consolidation. Nonunion may occur either as a result of a poor mechanical or biological environment at the fracture area or as a combination of the 2.10 The treatment of long bone fracture nonunion has been discussed in the orthopedic literature and is related to the type of nonunion. The technique selected for treating nonunion depends on whether the nonunion is hypervascular or avascular and whether the alignment of the fragment is satisfactory.11

The nonunion therapeutic intervention aims at improving the mechanical and biological environment at the nonunion area.6 The current failure rate in nonunion surgery is approximately 20%.12 Such a failure rate could be attributed to a failure to fully appreciate all of the factors involved in union. A new nonunion classification system addresses all factors that may be implicated in a fracture nonunion, considering the following elements: cellular environment, growth factors, bone matrix, and mechanical stability, the diamond concept which will significantly influence the treatment of nonunion.13 The new scoring system of Calori et al9 is currently the only available system that successfully fulfilled the requirements for treating nonunion. But validation of such a system was lacking.

In our series, 40 patients with lower extremity nonunion were extensively reviewed and classified into categories according to the nonunion scoring system of Calori et al.9 In comparing the actual management of our patients to those recommended by Calori et al,9 both had similar results, which were documented statistically. Our findings support the clinical application of such a system with nonunion cases, mainly those of significant complexity. For us, it was difficult, if not impossible to find distinct differentiation between category 2 (specialized care) and 3 (specialized care and management) in the Calori et al9 system. Soo both were grouped together to ease the application of the system as group 1 with a score <25 receiving standard treatment, group 2 with a score of 25 to 75 receiving specialized treatment such as Ilizarov, vascularized graft, bone transport, bone morphogenic protein, and/or fixation according to surgeon experience and capability, and group 3 with a score <75 undergoing amputation.

We conclude that, the new nonunion scoring system developed by Calorie et al9 system may have more valid guidelines for treatment of lower extremity fracture nonunion.  

References

  1. Crenshaw H. Delayed union and non-union of fractures. In: Crenshaw AH, ed. Campbell's Operative Orthopaedic. 3rd ed. St. Louis, MO: CV Mosby; 1987:2053-2118.
  2. Gerstenfeld LC, Cullinane DM, Barnes GL, Einhorn TA. Fracture healing as a post-natal developmental process: molecular, spatial, and temporal aspects of its regulation. J Cell Biochem. 2003; 88(5):873-884.
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  9. Calori GM, Phillips M, Jeetle S, Tagliabue L, Giannoudis PV. Classification of non-union: Need for a new scoring system? Injury Int JCare Injured. 2008; 39(Suppl 2):S59-63.
  10. Biggi F. The biology of fracture healing as related to intramedullary locked nailing. In: Kempf I, Leung KS, eds. Practice of Intramedullary Locked Nails. New York, NY: Springer-Verlag; 2002:5-10.
  11. La Velle DG. Delayed union and non-union of fracture. In: Canale ST, ed. Campbell's Operative Orthopaedics. 9th ed. St Louis, MO: Mosby; 1998:2579-2629.
  12. Tzioupis C, Giannoudis PV. Prevalence of long-bone non-unions. Injury. 2007; 38(Suppl 2):S3-9.
  13. Giannoudis PV, Einhorn TA, Marsh D. Fracture healing: the diamond concept. Injury. 2007; 38(Suppl 4):S3-6.

Authors

Drs Abumunaser and Al-Sayyad are from the Department of Orthopedic Surgery, King Abdulaziz University Hospital, Jeddah, Saudi Arabia.

Drs Abumunaser and Al-Sayyad have no relevant financial relationships to disclose.

Correspondence should be addressed to: Mohammed J. Al-Sayyad, MD, FRCSC, Department of Orthopedic Surgery, PO Box 1817, Jeddah, 21441, Saudi Arabia (abojalal@aol.com).

doi: 10.3928/01477447-20110317-31

10.3928/01477447-20110317-31

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