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
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
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
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.
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
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
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).
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
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
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.
- Crenshaw H. Delayed union and non-union of fractures. In: Crenshaw
AH, ed. Campbell's Operative Orthopaedic. 3rd ed. St. Louis, MO: CV
- 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.
- McKee M. Aseptic non-union. In: Ruedi TP, Murphy WM ed.
AO-Principles of Fracture Management. New York, NY: Georg Thieme Verlag;
- Hernigou P, Poignard A, Beaujean, Rouard H. Percutaneous autologous
bone-marrow grafting for non-unions. J Bone Joint Surg Am. 2005;
- Calori GM, Albisetti W, Agus A, Iori S, Tagliabue L. Risk factors
contributing to fracture non-union. Injury. 2007; 38(Suppl
- Weber BG, Cech O. Pseudoarthrosis. New York, NY: Grune and
- Catagni MA, Maiocchi B. Treatment of Fractures, Non-union, and
Bone Loss of the Tibia with the Ilizarov Method. London, England: Smith
& Nephew; 1998:90.
- Paley D, Catagni MA, Argnani F, Villa A, Benedetti GB, Cattaneo R.
Ilizarov treatment of tibial non-unions with bone loss. Section 1. Clin
Orthop Relat Res. 1989; (241):146-165.
- 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.
- 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.
- La Velle DG. Delayed union and non-union of fracture. In: Canale ST,
ed. Campbell's Operative Orthopaedics. 9th ed. St Louis, MO: Mosby;
- Tzioupis C, Giannoudis PV. Prevalence of long-bone non-unions.
Injury. 2007; 38(Suppl 2):S3-9.
- Giannoudis PV, Einhorn TA, Marsh D. Fracture healing: the diamond
concept. Injury. 2007; 38(Suppl 4):S3-6.
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
Correspondence should be addressed to: Mohammed J. Al-Sayyad, MD, FRCSC,
Department of Orthopedic Surgery, PO Box 1817, Jeddah, 21441, Saudi Arabia