www.jkfas.org pISSN 1738-3757 eISSN 2288-8551 J Korean Foot Ankle Soc 2015;19(2):73-76 http://dx.doi.org/10.14193/jkfas.2015.19.2.73
no history of total hip/knee joint arthroplasty, self-indulgence, and heavy labor. He could continue routine daily work without any difficulty. Diagnosis of diabetes mellitus was confirmed 22 months ago at another clinic. Diabetes was well-controlled by metformin monotherapy. Glycated hemoglobin (HbA1c) was measured 6.4% preoperatively. During the period of hospitalization, average blood glucose level was 126.3 mg/dL (range, 80-182 mg/dL). The clinical evidence of diabetic neuropathy or sensory deficit of foot and ankle were not confirmed.
By physical examination, swollen heel was identified, but there were no ecchymosis, localized tenderness, and palpable gap in the heel cord. The mid-calf circumference was 34 cm bilaterally.
Functional loss of the triceps surae complex resulted in a calcaneal gait. On the simple radiograph, about 1.5 cm upwardly displaced large avulsed fragment of calcaneal tubercle was observed. Addi- tionally, another sclerotic insufficiency avulsion fracture was com- bined which slipped upwardly parallel to the fused apophyseal line (Fig. 1). Preoperative American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score was 88 point.
The operation was performed under spinal anesthesia. In the prone position, avulsed fragment was reduced and fixed with can- nulated screws, cerclage wiring and nonabsorbable sutures (Fig.
The calcaneal insufficiency avulsion fracture has been consid- ered to occur in the area of fused apophysisin adult without signif- icant history of trauma or overuse activities. It has been described in patients with diabetic Charcot neuroarthropathy, neuropathic amyloidosis, and severe osteoporosis. We report a case of 50-year- old male who experienced non-traumatic diabetic calcaneal in- sufficiency fracture. He had well-controlled type 2 diabetes and showed no diabetes-related complications including peripheral neuropathy. The patient provided informed consent for the study.
CASE REPORT
A 50-year-old type 2 diabetic patient visited an outpatient clinic with complaints of spontaneously swollen heel. After light jump- ing exercise, negligible discomfort developed three days prior to the visit. His height and weight were 163 cm and 55 kg. He had
Case Report
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The calcaneal insufficiency avulsion fracture usually occurs in an area of fused apophysis in adults without significant history of trauma or overuse activities. It is an uncommon injury which has been described in patients with complicated diabetes, Charcot neuroar- thropathy, amyloidosis with neuropathy, severe osteoporosis, and other conditions. Discussion of the issue of fracture location is still not sufficient. We report on a case of a 50-year-old male who experienced a non-traumatic diabetic calcaneal insufficiency fracture. In- traoperatively, a biopsy specimen was obtained from the exposed fracture site for histological study. We assume that the calcaneal fused apophyseal line is the weak point of failure due to various incomplete mixtures of trabecular bone, woven bone, and cartilaginous tissues, and may fail when repeated tensile stress is imposed.
Key Words: Diabetes mellitus, Calcaneus, Insufficiency fracture
Calcaneal Insufficiency Avulsion Fracture in a
Well-Controlled Type 2 Diabetic Patient: A Case Report
Seong-Tae Kim, Myung-Sang Moon, Ki-Tae Kwon, Bong-Keun Park, Chang Won Ha*, Jungtae Ahn
Department of Orthopaedic Surgery and Traumatology, *Department of Pathology, Cheju Halla General Hospital, Jeju, Korea
Received November 14, 2014 Revised April 27, 2015 Accepted May 3, 2015 Corresponding Author: Jungtae Ahn
Department of Orthopaedic Surgery and Traumatology, Cheju Halla General Hospital, 65 Doryeong-ro, Jeju 690-766, Korea
Tel: 82-64-740-5410, Fax: 82-64-743-3110, E-mail: [email protected] Financial support: None.
Conflict of interest: None.
74 Vol. 19 No. 2, June 2015
area. Fragmented bone trabeculae, hemorrhage, necrosis and few chronic inflammatory cells were noted (Fig. 3).
Postoperatively, immobilization in a short leg cast was contin- ued for six weeks. Twelve weeks of non―weight-bearing crutch ambulation was followed by full weight-bearing. At postoperative four months follow-up, about 9 mm proximal migration of fixated fragment was identified, but patient had no significant problems.
Eleven months after surgery, all hardware and migrated fragment were removed. At the final follow-up, the patient showed full re- covery. Range of ankle motion was the same as compared to the opposite side with dorsiflexion 20o and plantar flexion 50o. Ankle plantar flexion power was checked to be grade five. Final AOFAS hindfoot score was 95 point.
DISCUSSION
Calcaneal insufficiency avulsion fracture is uncommon injury which has been described in patients with diabetes, Charcot neu- roarthropathy, amyloidosis with neuropathy, and severe osteo- porosis.1-3) High occurrence of the calcaneal avulsion fracture in patients who had undergone renal transplantation was reported.2) Miki et al.4) reported five cases of calcaneal stress fractures in pos- 2). Intraoperatively, biopsy specimen was obtained from exposed
fracture site. Histologic finding showed that hyaline cartilaginous chondrocytes were arranged in small clusters surrounded by large amounts of moderately violescent stained matrix and abnormally oriented trabecular bone mixed with woven bones indicating various osteopathies and healing callus in insufficiency fracture Figure 2.
Figure 2. Fracture was fixed with cerclage wiring, cannulated screw and non-absorbable sutures.
A B
C D
Figure 1.
Figure 1. (A) Lateral radiograph shows about 1.5 cm upwardly displaced large avulsed fragment of calcaneal tubercle.
Additionally, another sclerotic insuf- ficiency avulsion fracture was combined which slipped upwardly parallel to the fused apophyseal line. (B) Postoperative radiograph shows reposition and fixation of fracture fragment with cerclage wiring and cannulated screws. (C) Postoperative four months radiograph shows re-dis- placed fracture fragment. (D) Final follow- up radiograph shows hardware removal.
www.jkfas.org 75 Seong-Tae Kim, et al. Biopsy Pattern in Calcaneal Insufficiency Fracture
There have been no plausible explanation why in some diabetic patients develop Charcot neuroarthropathy with tarsal disintegra- tion combined with insufficiency avulsion fracture of posterior tu- bercle and fused apophysis of calcaneus. Diabetes mellitus affects the various organs and tissues such as nerve, vessel, tendon and bones; thus it can lead to neuropathy, atherosclerosis, tendinopa- thy, and so on. It can be followed by various pedal complications including ulceration, tissue necrosis, infection, neuropathic joint and spontaneous bony dissolution. Also skeletal fragility can be increased in diabetes with various factors. Generally, fracture risk is increased in both type 1 and type 2 diabetes mellitus.6) Also dis- ease related complications increase the fracture risk by increasing risk of falls and causing regional osteopenia. Diabetic neuropathy can lower cortical bone mass in the distal limbs compared with those without neuropathy.7) There are some differences in the mechanisms by which skeletal fragility is increased in type 1 and type 2 diabetes mellitus. Factors including regional osteopenia, increased fall risk, decreased bone quality, specific disease treat- terior tuberosity as an adverse event following total hip and total
knee arthroplasty in non-diabetic adults. This fracture has been considered to occur without history of trauma or overuse activi- ties. The pulling force of triceps surae often results in an avulsion component. The epidemiologic study of the calcaneal avulsion fracture has been demonstrated in a few studies, but these are in- cluding traumatic injury. According to previous studies, calcaneal insufficiency fractures occur in several morphologic forms. Lee et al.5) tried to classify the avulsion patterns of the calcaneal tuberos- ity. There is a slight variation in the traditional fracture pattern. Ra- diographically, the fracture line is parallel to the fused apophyseal growth plate, usually only encompassing the superior calcaneal portion and extends horizontally distal to the Achilles insertion.
However, no authors discussed the pathogenesis of calcaneal in- sufficiency fracture around the fused apophyseal line in adult on the scientific ground. Also with its low incidence, there are some case series but no well-designed epidemiologic research confined to non-traumatic injury.
A B
C
Figure 3.
Figure 3. Histologic appearance of insufficiency fracture site is shown in low-power view (H&E stain, ×100; A), high-power view (H&E stain,
×400; B). Hyaline cartilaginous chondrocytes were arranged in small clusters surrounded by large amounts of moderately violescent stained matrix. (C) Abnormally oriented trabecular bone mixed with woven bones (arrow) are seen which is indicating various osteopathies and healing callus (Masson-Trichrome stain, ×200).
76 Vol. 19 No. 2, June 2015
tissues, and may fail when the repeated tensile stress is imposed.
We hope the hypothesis being supported by further studies in the coming years.
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ment modality (e.g., thiazolidinediones) are known as the causes of increased skeletal fragility in type 2 diabetes mellitus.6)
Higher incidence of fractures in the elderly and diabetics are known to be due to abnormal cross-link formation of the collagen which reduce pliability and contracture of the motor unit second- ary to the altered glycation.2,8) Generally, the altered carbohydrate metabolism in diabetics exerts effect on collagen cross-linking and collagen isomerization in cancellous and cortical bone, and such changes are determined by the degree of turn-over suppression in bone. Bone matrix is the structured composite consisting of a protein phase and a mineral phase. Mineral phase provides the stiffness and the collagen fibers provide the ductility and the ability to absorb energy (i.e., toughness).9) Glycation of bone tissue has been shown to make bone more brittle with decrease in the de- formability of bone before fracture. Histologic finding showed that hyaline cartilaginous chondrocytes were arranged in small clusters surrounded by large amounts of moderately violescent stained bone matrix and abnormally oriented trabecular bone mixed with woven bones. It is indicative of various osteopathies and healing processand incomplete ossification and calcification in insufficien- cy fracture area.
Osteopenia and altered cross-linking of bone collagen in diabet- ics create thin cortical and cancellous bones which may not be able to resist severe tension at the tendon attachment, and there- fore a segment of bone may be pulled off by tendon during sud- den triceps muscle contraction. We assume that calcaneal fused apophyseal line is the weak point to failure due to various incom- plete mixture of trabecular bone, woven bone and cartilaginous
