e9(1) C OPYRIGHT Ó 2014
BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
Calcaneal Stress Fracture: An Adverse Event Following Total Hip and Total Knee Arthroplasty A Report of Five Cases Takaaki Miki, MD, PhD, Takahito Miki, MD, and Akihiro Nishiyama, MD Investigation performed at the Department of Orthopedic Surgery, Unnan Municipal Hospital, Unnan City, Shimane Prefecture, Japan
Background: Stress fractures have been reported to occur in the pubis, femoral neck, proximal part of the tibia, and fabella during the postoperative period following total knee or total hip arthroplasty. However, to our knowledge, calcaneal stress fractures after total hip or total knee arthroplasty have not been reported in the English-language literature. Most orthopaedic surgeons are not familiar with calcaneal stress fractures that may occur in elderly patients after a total knee or total hip arthroplasty. Methods: We retrospectively reviewed the clinical features, imaging findings, and bone mineral content of the proximal part of the femur and the distal end of the radius in five patients who had a calcaneal stress fracture after a total knee or total hip arthroplasty. Results: All patients were women with a mean age of 76.8 years. All fractures occurred in the calcaneus on the same side as the arthroplasty. The fracture appeared at a mean of 10.2 weeks postoperatively. All patients reported heel pain on walking. Swelling and local heat were found in four and three patients, respectively. Pain was elicited by squeezing the calcaneus in all patients. Early radiographs had normal findings in two patients, and an irregular sclerotic line appeared later in the radiographs of all patients. All fractures were treated conservatively. Four fractures healed uneventfully, but one fracture displaced. All patients had osteoporosis. Conclusions: Calcaneal stress fractures during the postoperative period following total knee or total hip arthroplasty may not be as rare as previously thought. Because clinical symptoms of the fracture appear insidiously and radiographic findings are absent or subtle in the early stage, a high index of suspicion is needed for orthopaedic surgeons to make the correct diagnosis. Magnetic resonance imaging or repeated radiographs may be necessary to make the correct diagnosis when no abnormality is apparent on the initial radiograph. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
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tress fractures of the lower extremity are rare events that occur during the postoperative period following total knee or hip replacement. They have been reported to occur in the pubis1, femoral neck2-8, proximal part of the tibia9-11, and fabella12 following total knee arthroplasty and in the pubis13-16 following total hip arthroplasty. To our knowledge, calcaneal stress fracture, however, has not been previously reported in the English-language literature as an adverse event following total knee or total hip arthroplasty. We describe our experience with
five patients who had a calcaneal stress fracture, including four who were seen after total knee arthroplasty and one who was seen after total hip arthroplasty. Materials and Methods Summary of the Cases of Five Patients
I
n our five patients, the preoperative diagnosis was osteoarthritis of the knee (four patients) and the hip (one patient). Arthroplasty (total knee arthroplasty in four patients and total hip arthroplasty in one) was successfully performed,
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
J Bone Joint Surg Am. 2014;96:e9(1-6)
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http://dx.doi.org/10.2106/JBJS.L.01472
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Fig. 1-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 1-B
Figs. 1-A and 1-B. Case 1. Fig. 1-A A sclerotic line (arrows) traverses the long axis of the calcaneus on this radiograph made eight weeks after ipsilateral total knee arthroplasty and two weeks after the onset of symptoms. This is the typical radiographic appearance of a calcaneal stress fracture. Fig. 1-B The posterior part of the calcaneal tuberosity had displaced moderately, but healing of the fracture (arrows) was evident twelve weeks later. and the immediate postoperative course was uneventful in each patient. The clinical symptoms of the calcaneal stress fracture appeared at a mean of 10.2 weeks following surgery (Table I). The symptoms at the time of presentation included heel pain (five patients), swelling (four patients), and warmth (three patients). The stand on heel test and the squeeze test were both positive in all five patients. The initial radiograph showed a sclerotic line traversing the calcaneus in three patients. Symptoms subsided in a few weeks with protected weight-bearing. Four fractures healed uneventfully, and one fracture partially displaced.
Clinical Tests The stand on heel test is positive when heel pain is elicited by bearing weight on the heel. The squeeze test is positive when pain is elicited as the body of the calcaneus is squeezed by the examiner’s thumb and fingers. To test their reliability, these two tests were carried out by physiotherapists at our hospital on fifty heels of twentyfive volunteer patients who were able to walk and had no pain, swelling, or local heat around the heel. The tests were positive in three heels of two patients whose radiographs of the calcaneus showed no abnormal finding. In this small sample, the false-positive rate was 4% for the stand on heel test and 6% for the squeeze test.
Source of Funding There was no external funding source for this study.
Results ive patients, all women with a mean age of 76.8 years, were seen with heel pain within several weeks after a total hip or total knee arthroplasty. The first patient (Case 1) was a seventysix-year-old woman who had osteoarthritis of both knees and underwent total knee arthroplasty on the right side. Six weeks postoperatively, she had acute pain develop in the right heel. When she visited us two weeks later, the right ankle and foot were swollen, red, and warm. The stand on heel test and the squeeze test were both positive. Radiographs showed a sclerotic line, the typical sign of a stress fracture, through the tuberosity of the calcaneus (Fig. 1-A). We prescribed analgesics and advised her to limit her activities. When she was seen again at twenty weeks postoperatively, she had no heel pain and the radiographs
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demonstrated a healed but partially displaced fracture (Fig. 1-B). Prior to the total knee arthroplasty, she had been diagnosed with osteoporosis and was taking bisphosphonates. Dual x-ray absorptiometry (DXA) measurement of bone mineral density of the femoral neck, at thirty-seven weeks postoperatively, was 0.464 g/cm2; the T-score was 22.51, and the Z-score was 20.90. The second patient (Case 2) was a seventy-seven-year-old woman who had severe osteoarthritis of both knees and the right hip. The right lower extremity was several centimeters shorter than the left, and the right hip had a moderate adduction contracture. She underwent a left total knee arthroplasty. At twenty-three weeks postoperatively, she suddenly developed heel pain on the left side. When she consulted us five days later, the left ankle and foot were diffusely swollen and warm. The findings of the stand on heel test and the calcaneal squeeze test were both positive. Radiographs of the heel at that time demonstrated no abnormal findings (Fig. 2-A). We recommended limited and protected weight-bearing on the heel. Two weeks later, repeat radiographs demonstrated a sclerotic line traversing the calcaneus (Fig. 2-B). One month after the onset of heel pain, the local heat and swelling had almost completely subsided and the findings of the stand on heel test and the squeeze test were negative. DXA bone mineral densitometry of the left femoral neck, measured at twenty-six weeks postoperatively, was 0.386 g/cm2, the T-score was 23.7, and the Z-score was 21.6. Treatment for osteoporosis with parathyroid hormone was initiated at six months postoperatively. A DXA scan performed at seventeen months postoperatively on the left radius showed bone mineral density of 0.388 mg/cm2; the T-score was 25.4, and the Z-score was 20.8. The third patient, an eighty-four-year-old woman (Case 3) with osteoarthritis of both knees, underwent total knee arthroplasty of the right knee followed by total knee arthroplasty of the left knee twenty-six weeks later. Following the second
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CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
TABLE I Patient Demographics, Time of Fracture After Arthroplasty, Clinical Signs and Test Results, Linear Sclerosis of the Calcaneus on the Initial Radiograph, and Bone Mineral Density Case
Age (yr) Sex Postop. timing of appearance of clinical signs (wk)
1
2
3
4
5
76
77
84
68
79
F
F
F
F
F
6
23
6
10
6
Swelling*
1
1
1
2
1
Local heat*
1
1
2
2
1
Stand on heel test*
1
1
1
1
1
Squeeze test*
1
1
1
1
1
Linear sclerosis on initial radiograph Bone mineral density of the femoral neck (g/cm2) T-score Z-score
1
2
1
2
1
0.464 22.51 20.90
0.386 23.7 21.6
0.389 23.7 21.5
0.513 22.5 20.5
0.477 22.8 20.5
*The plus sign indicates a positive finding, and a minus sign indicates a negative finding.
arthroplasty, the postoperative course was initially uneventful, but pain suddenly developed in the left heel at six weeks postoperatively. When she consulted us one week later, the left ankle was diffusely swollen and the stand on heel and squeeze tests were both positive. Radiographs demonstrated a slightly sclerotic line traversing the upper portion of the calcaneal tuberosity (Fig. 3-A). A calcaneal stress fracture was suspected, and she was instructed to limit weight-bearing activity and use a cane. Three weeks later, the swelling had subsided nearly completely, but she still had heel pain and the squeeze test was
Fig. 2-A
positive. A radiograph made at that time demonstrated a sclerotic line in the calcaneal tuberosity (Fig. 3-B). Thirteen weeks postoperatively, the findings of the stand on heel test and the squeeze test were both negative. A DXA scan carried out thirteen months postoperatively showed bone mineral density in the femoral neck of 0.389 g/cm2; the T-score was 23.7, and the Z-score was 21.5. In the distal end of the radius, the bone mineral density was 0.467 g/cm2; the T-score was 23.8, and the Z-score was 0.9. The fourth patient (Case 4), a sixty-eight-year-old woman with bilateral knee arthritis, underwent a right total
Fig. 2-B
Figs. 2-A and 2-B Case 2. Fig. 2-A There is no abnormal finding on this radiograph of the calcaneus made twenty-four weeks after total knee arthroplasty and five days after the onset of symptoms. Fig. 2-B The sclerotic line (arrows) had become apparent two weeks later.
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Fig. 3-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 3-B
Figs. 3-A and 3-B Case 3. Fig. 3-A There is only a slight sclerotic line (arrows) in the calcaneus on this radiograph made seven weeks after total knee arthroplasty and one week after the onset of symptoms. Fig. 3-B The sclerotic line (arrows) had become more apparent three weeks later.
knee arthroplasty. Acute pain developed in the right heel ten weeks postoperatively. When she consulted us five days later, there was no apparent swelling or local heat around the ankle. The stand on heel test and the calcaneal squeeze test were both positive. Radiographs demonstrated no abnormal findings of the calcaneus (Fig. 4-A). With a tentative diagnosis of a calcaneal stress fracture, we advised her to avoid weight-bearing. Two weeks later, the heel pain had subsided and she could bear weight on the
Fig. 4-A
affected heel. A radiograph demonstrated a sclerotic line traversing the calcaneal tuberosity (Fig. 4-B). When seen seven months postoperatively, she had no heel pain. Bone mineral density of the right femoral neck, measured at thirty-seven weeks postoperatively, was 0.513 g/cm2; the T-score was 22.5, and the Z-score was 20.5. The last patient (Case 5) was a remarkably strong seventynine-year-old woman who underwent a right total hip arthroplasty
Fig. 4-B
Figs. 4-A and 4-B Case 4. Fig. 4-A There are no abnormal findings of the calcaneus on the radiograph made eleven weeks after total knee arthroplasty and five days after the onset of symptoms. Fig. 4-B A sclerotic line (arrows) had become apparent in the calcaneal tuberosity two weeks later.
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Fig. 5-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 5-B
Figs. 5-A and 5-B Case 5. Fig. 5-A A sclerotic line (arrows) traverses the long axis of the calcaneal tuberosity at seventeen weeks after total hip arthroplasty and five weeks after the onset of symptoms. Fig. 5-B T1-weighted magnetic resonance imaging clearly demonstrates a linear zone of low signal intensity (arrows), which indicated a fracture line, and a broader, poorly defined area of signal intensity alteration in the bone marrow.
and started bearing full weight on the operatively treated side on the day after surgery. She returned to light farm work three weeks later. About six weeks postoperatively, she developed acute pain in the right heel and the ankle was markedly swollen and warm. The stand on heel test and the calcaneal squeeze test were both positive. She was advised to avoid weight-bearing, and the pain, swelling, and local heat had subsided by twelve weeks postoperatively. Radiographs made seventeen weeks postoperatively revealed a sclerotic line traversing the calcaneal tuberosity (Fig. 5-A). Magnetic resonance imaging demonstrated a fracture line with bone marrow edema surrounding the fracture (Fig. 5-B). The squeeze test continued to have slightly positive findings at eighteen weeks postoperatively. Bone mineral density of the femoral neck, measured at fifteen weeks postoperatively, was 0.477 g/cm2; the T-score was 22.8, and the Z-score was 20.5. She started osteoporosis treatment with bisphosphonates five months postoperatively. Discussion tress fractures of the femoral neck2-8, pubis1, proximal part of the tibia9-11, and fabella12 have been reported following total knee arthroplasty, while stress fractures of the pubis have been reported following total hip arthroplasty13-16. Calcaneal stress fracture following joint replacement, to our knowledge, has not been previously reported in the English-language literature. Calcaneal stress fractures are commonly seen in the healthy bone of military recruits17-23. However, all five patients in this study were osteoporotic; the bone mineral content of the femoral neck in the five patients was 57%, 49%, 49%, 65%, and 61%, respectively, of the mean value in young adults. Calcaneal insufficiency fractures occur in bones having less than normal elastic resistance to compression and stretching. They occur in elderly individuals with osteoporosis without any antecedent
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trauma or overuse24,25 and are not commonly recognized24-30. The cases of two patients reported by Ito et al.24, the cases of six patients reported by Alonso-Bartolome et al.25, and the five patients in the present report are the best examples in the literature. A calcaneal insufficiency fracture might occur more readily after joint replacement surgery because the mechanical stresses on the operatively treated limb may increase considerably as a result of pain relief in the early postoperative period following the arthroplasty26,27. DXA scans of the distal end of the radius were carried out in addition to scans of the femoral neck in four patients (Cases 2, 3, 4, and 5) to distinguish generalized osteoporosis from disuse osteoporosis of the lower extremity. However, we could not arrive at a clear-cut conclusion about the type of osteoporosis. Bone mineral content was decreased in the femoral neck and in the distal end of the radius to the same degree in one patient (Case 3), while it was disproportionately decreased more in the femoral neck in another patient (Case 4) and in the distal end of the radius in two patients (Cases 2 and 5). We carried out 516 arthroplasties (409 total knee arthroplasties and 107 total hip arthroplasties) at our current hospital over the six years since 2007. We encountered no calcaneal stress fractures except those in the five patients described in the present report. Thus, the overall rate of calcaneal stress fracture has been less than 1% over that six-year period. The fractures in four patients (Cases 2, 3, 4, and 5) occurred during one seven-month period, during which we performed twenty-eight total knee arthroplasties (nineteen in female patients and nine in male patients) and five total hip arthroplasties (all female patients), creating an incidence of 12% during those seven months. Our operative technique and postoperative physiotherapy routine did not change remarkably during that time, and we cannot identify any reason for this substantial increase in the number
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of calcaneal stress fractures. Perhaps these insufficiency fractures following joint replacement surgery are more common than appreciated. They can be easily overlooked unless suspected, and both Ito et al.24 and Alonso-Bartolome et al.25 stated that often they might be underrecognized and mistaken for other conditions. All five stress fractures in this series occurred on the same side as the arthroplasty. Following surgery, the operatively treated limb, relieved of preoperative pain, perhaps became the main supporting limb, and the increased mechanical stress might have been the cause of the fracture in at least some of the patients. It is unknown why all thirteen patients in both the present report and the reports by Ito et al.24 and by Alonso-Bartolome25 were female. In part, it may be because osteoporosis occurs more frequently in females, and nearly 80% of the candidates for joint replacement in our hospital are female. Orthopaedic surgeons should be aware of the potential adverse event of a calcaneal insufficiency stress fracture following total knee arthroplasty or total hip arthroplasty, especially in osteoporotic women. The symptoms in our patients appeared at a mean of ten weeks (range, six to twenty-three weeks) postoperatively. The patients all complained of heel pain and could not bear weight on the affected heel. Swelling, local heat, or redness around the heel were not always present, but the results of the stand on heel test and the squeeze test were positive in all patients. The diagnosis is primarily a clinical one as early radiographic
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
features are absent or subtle. In our patients, the typical irregular sclerotic line traversing the calcaneus22 appeared radiographically between seven and thirty-one days after the onset of clinical signs and symptoms. The patient needs no special treatment but should avoid weight-bearing until the pain disappears. This typically takes approximately one month. Fracture displacement is rare, but it occurred in one patient (Case 1) with moderate but asymptomatic dorsal displacement of the tuberosity fragment. n
Takaaki Miki, MD, PhD Akihiro Nishiyama, MD Department of Orthopedic Surgery, Unnan Municipal Hospital, Iida 96-1, Daito Town, Unnan City, Shimane Prefecture 699-12, Japan. E-mail address for T. Miki: [email protected]. E-mail address for A. Nishiyama: [email protected] Takahito Miki, MD Miki Orthopedic and Pain Clinic, Kandachi 706, Aikawa, Hikawa-Town, Izumo City, Shimane Prefecture 699-0615, Japan. E-mail: [email protected]
References 1. Thienpont E, Simon JP, Spaepen D, Fabry G. Bifocal pubic stress fracture after ipsilateral total knee arthroplasty in rheumatoid arthritis. A case report. Acta Orthop Belg. 2000 Apr;66(2):197-200. 2. Fipp G. Stress fractures of the femoral neck following total knee arthroplasty. J Arthroplasty. 1988;3(4):347-50. 3. Hardy DCR, Delince PE, Yasik E, Lafontaine MA. Stress fracture of the hip. An unusual complication of total knee arthroplasty. Clin Orthop Relat Res. 1992 Aug;281(281):140-4. 4. Kumm DA, Rack C, R¨utt J. Subtrochanteric stress fracture of the femur following total knee arthroplasty. J Arthroplasty. 1997 Aug;12(5):580-3. 5. Lesniewski PJ, Testa NN. Stress fracture of the hip as a complication of total knee replacement. Case report. J Bone Joint Surg Am. 1982 Feb;64(2):304-6. 6. Palance Martin D, Albareda J, Seral F. Subcapital stress fracture of the femoral neck after total knee arthroplasty. Int Orthop. 1994 Oct;18(5):308-9. 7. McElwaine JP, Sheehan JM. Spontaneous fractures of the femoral neck after total replacement of the knee. J Bone Joint Surg Br. 1982;64(3):323-5. 8. Pankaj A, Malhotra R, Logani V, Bhan S. Bilateral femoral neck stress fractures following total knee arthroplasty: a case report and review of literature. Arch Orthop Trauma Surg. 2007 Sep;127(7):549-52. Epub 2007 May 15. 9. Jean JL, Lee CH, Pan RY, Chang JH, Chern TC. Stress fracture of the proximal tibia after total knee arthroplasty: a case report. J Formos Med Assoc. 2001 Aug;100(8):561-4. 10. Petje G, Landsiedl F. Stress fracture of the tibia after total knee arthroplasty. Arch Orthop Trauma Surg. 1997;116(8):514-5. 11. Rand JA, Coventry MB. Stress fractures after total knee arthroplasty. J Bone Joint Surg Am. 1980 Mar;62(2):226-33. 12. Theodorou SJ, Theodorou DJ, Resnick D. Painful stress fractures of the fabella in patients with total knee arthroplasty. AJR Am J Roentgenol. 2005 Nov;185(5):1141-4. 13. Christiansen CG, Kassim RA, Callaghan JJ, Marsh JL, Schmidt AH. Pubic ramus insufficiency fractures following total hip arthroplasty. A report of six cases. J Bone Joint Surg Am. 2003 Sep;85(9):1819-22. 14. Launder WJ, Hungerford DS. Stress fracture of the pubis after total hip arthroplasty. Clin Orthop Relat Res. 1981 Sep;(159):183-5. 15. Marmor L. Stress fracture of the pubic ramus stimulating a loose total hip replacement. Clin Orthop Relat Res. 1976 Nov-Dec;(121):103-4.
16. Oh I, Hardacre JA. Fatigue fracture of the inferior pubic ramus following total hip replacement for congenital hip dislocation. Clin Orthop Relat Res. 1980 Mar-Apr;(147):154-6. 17. Greaney RB, Gerber FH, Laughlin RL, Kmet JP, Metz CD, Kilcheski TS, Rao BR, Silverman ED. Distribution and natural history of stress fractures in U.S. Marine recruits. Radiology. 1983 Feb;146(2):339-46. 18. Darby RE. Stress fractures of the os calcis. JAMA. 1967 Jun 26;200(13): 1183-4. 19. Hopson CN, Perry DR. Stress fractures of the calcaneus in women marine recruits. Clin Orthop Relat Res. 1977 Oct;(128):159-62. 20. Giladi M, Alcalay J. Stress fracture of the calcaneus—still an enigma in the Israeli Army. JAMA. 1984 Dec 14;252(22):3128-9. 21. Hullinger CW. Insufficiency fracture of the calcaneus. Similar to march fracture of the metatarsal. J Bone Joint Surg. 1944;26:751-7. 22. Leabhart JW. Stress fractures of the calcaneus. J Bone Joint Surg Am. 1959 Oct;41:1285-90. 23. Sormaala MJ, Niva MH, Kiuru MJ, Mattila VM, Pihlajam¨aki HK. Stress injuries of the calcaneus detected with magnetic resonance imaging in military recruits. J Bone Joint Surg Am. 2006 Oct;88(10):2237-42. 24. Ito K, Hori K, Terashima Y, Sekine M, Kura H. Insufficiency fracture of the body of the calcaneus in elderly patients with osteoporosis: a report of two cases. Clin Orthop Relat Res. 2004 May;(422):190-4. 25. Alonso-Bartolome P, Blanco R, Canga A, Martı´nez-Taboada VM. Insufficiency fractures of the calcaneus: a diagnostic pitfall for ankle arthritis. J Rheumatol. 2006 Jun;33(6):1140-2. 26. van Loon CJM, Oyen WJG, de Waal Malefijt MC, Verdonschot N. Distal femoral bone mineral density after total knee arthroplasty: a comparison with general bone mineral density. Arch Orthop Trauma Surg. 2001 May;121(5):282-5. 27. Liu TK, Yang RS, Chieng PU, Shee BW. Periprosthetic bone mineral density of the distal femur after total knee arthroplasty. Int Orthop. 1995;19(6):346-51. 28. Daffner RH, Pavlov H. Stress fractures: current concepts. AJR Am J Roentgenol. 1992 Aug;159(2):245-52. 29. Buchanan J, Greer RB 3rd. Stress fractures in the calcaneus of a child. A case report. Clin Orthop Relat Res. 1978 Sep;(135):119-20. 30. Stein RE, Stelling FH. Stress fracture of the calcaneus in a child with cerebral palsy. J Bone Joint Surg Am. 1977 Jan;59(1):131.
BY
T HE J OURNAL
OF
B ONE
AND J OINT
S URGERY, I NCORPORATED
Calcaneal Stress Fracture: An Adverse Event Following Total Hip and Total Knee Arthroplasty A Report of Five Cases Takaaki Miki, MD, PhD, Takahito Miki, MD, and Akihiro Nishiyama, MD Investigation performed at the Department of Orthopedic Surgery, Unnan Municipal Hospital, Unnan City, Shimane Prefecture, Japan
Background: Stress fractures have been reported to occur in the pubis, femoral neck, proximal part of the tibia, and fabella during the postoperative period following total knee or total hip arthroplasty. However, to our knowledge, calcaneal stress fractures after total hip or total knee arthroplasty have not been reported in the English-language literature. Most orthopaedic surgeons are not familiar with calcaneal stress fractures that may occur in elderly patients after a total knee or total hip arthroplasty. Methods: We retrospectively reviewed the clinical features, imaging findings, and bone mineral content of the proximal part of the femur and the distal end of the radius in five patients who had a calcaneal stress fracture after a total knee or total hip arthroplasty. Results: All patients were women with a mean age of 76.8 years. All fractures occurred in the calcaneus on the same side as the arthroplasty. The fracture appeared at a mean of 10.2 weeks postoperatively. All patients reported heel pain on walking. Swelling and local heat were found in four and three patients, respectively. Pain was elicited by squeezing the calcaneus in all patients. Early radiographs had normal findings in two patients, and an irregular sclerotic line appeared later in the radiographs of all patients. All fractures were treated conservatively. Four fractures healed uneventfully, but one fracture displaced. All patients had osteoporosis. Conclusions: Calcaneal stress fractures during the postoperative period following total knee or total hip arthroplasty may not be as rare as previously thought. Because clinical symptoms of the fracture appear insidiously and radiographic findings are absent or subtle in the early stage, a high index of suspicion is needed for orthopaedic surgeons to make the correct diagnosis. Magnetic resonance imaging or repeated radiographs may be necessary to make the correct diagnosis when no abnormality is apparent on the initial radiograph. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Peer Review: This article was reviewed by the Editor-in-Chief and one Deputy Editor, and it underwent blinded review by two or more outside experts. The Deputy Editor reviewed each revision of the article, and it underwent a final review by the Editor-in-Chief prior to publication. Final corrections and clarifications occurred during one or more exchanges between the author(s) and copyeditors.
S
tress fractures of the lower extremity are rare events that occur during the postoperative period following total knee or hip replacement. They have been reported to occur in the pubis1, femoral neck2-8, proximal part of the tibia9-11, and fabella12 following total knee arthroplasty and in the pubis13-16 following total hip arthroplasty. To our knowledge, calcaneal stress fracture, however, has not been previously reported in the English-language literature as an adverse event following total knee or total hip arthroplasty. We describe our experience with
five patients who had a calcaneal stress fracture, including four who were seen after total knee arthroplasty and one who was seen after total hip arthroplasty. Materials and Methods Summary of the Cases of Five Patients
I
n our five patients, the preoperative diagnosis was osteoarthritis of the knee (four patients) and the hip (one patient). Arthroplasty (total knee arthroplasty in four patients and total hip arthroplasty in one) was successfully performed,
Disclosure: None of the authors received payments or services, either directly or indirectly (i.e., via his or her institution), from a third party in support of any aspect of this work. None of the authors, or their institution(s), have had any financial relationship, in the thirty-six months prior to submission of this work, with any entity in the biomedical arena that could be perceived to influence or have the potential to influence what is written in this work. Also, no author has had any other relationships, or has engaged in any other activities, that could be perceived to influence or have the potential to influence what is written in this work. The complete Disclosures of Potential Conflicts of Interest submitted by authors are always provided with the online version of the article.
J Bone Joint Surg Am. 2014;96:e9(1-6)
d
http://dx.doi.org/10.2106/JBJS.L.01472
e9(2) TH E JO U R NA L O F B O N E & JO I N T SU RG E RY J B J S . O RG V O L U M E 96-A N U M B E R 2 J A N UA R Y 15, 2 014 d
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Fig. 1-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 1-B
Figs. 1-A and 1-B. Case 1. Fig. 1-A A sclerotic line (arrows) traverses the long axis of the calcaneus on this radiograph made eight weeks after ipsilateral total knee arthroplasty and two weeks after the onset of symptoms. This is the typical radiographic appearance of a calcaneal stress fracture. Fig. 1-B The posterior part of the calcaneal tuberosity had displaced moderately, but healing of the fracture (arrows) was evident twelve weeks later. and the immediate postoperative course was uneventful in each patient. The clinical symptoms of the calcaneal stress fracture appeared at a mean of 10.2 weeks following surgery (Table I). The symptoms at the time of presentation included heel pain (five patients), swelling (four patients), and warmth (three patients). The stand on heel test and the squeeze test were both positive in all five patients. The initial radiograph showed a sclerotic line traversing the calcaneus in three patients. Symptoms subsided in a few weeks with protected weight-bearing. Four fractures healed uneventfully, and one fracture partially displaced.
Clinical Tests The stand on heel test is positive when heel pain is elicited by bearing weight on the heel. The squeeze test is positive when pain is elicited as the body of the calcaneus is squeezed by the examiner’s thumb and fingers. To test their reliability, these two tests were carried out by physiotherapists at our hospital on fifty heels of twentyfive volunteer patients who were able to walk and had no pain, swelling, or local heat around the heel. The tests were positive in three heels of two patients whose radiographs of the calcaneus showed no abnormal finding. In this small sample, the false-positive rate was 4% for the stand on heel test and 6% for the squeeze test.
Source of Funding There was no external funding source for this study.
Results ive patients, all women with a mean age of 76.8 years, were seen with heel pain within several weeks after a total hip or total knee arthroplasty. The first patient (Case 1) was a seventysix-year-old woman who had osteoarthritis of both knees and underwent total knee arthroplasty on the right side. Six weeks postoperatively, she had acute pain develop in the right heel. When she visited us two weeks later, the right ankle and foot were swollen, red, and warm. The stand on heel test and the squeeze test were both positive. Radiographs showed a sclerotic line, the typical sign of a stress fracture, through the tuberosity of the calcaneus (Fig. 1-A). We prescribed analgesics and advised her to limit her activities. When she was seen again at twenty weeks postoperatively, she had no heel pain and the radiographs
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demonstrated a healed but partially displaced fracture (Fig. 1-B). Prior to the total knee arthroplasty, she had been diagnosed with osteoporosis and was taking bisphosphonates. Dual x-ray absorptiometry (DXA) measurement of bone mineral density of the femoral neck, at thirty-seven weeks postoperatively, was 0.464 g/cm2; the T-score was 22.51, and the Z-score was 20.90. The second patient (Case 2) was a seventy-seven-year-old woman who had severe osteoarthritis of both knees and the right hip. The right lower extremity was several centimeters shorter than the left, and the right hip had a moderate adduction contracture. She underwent a left total knee arthroplasty. At twenty-three weeks postoperatively, she suddenly developed heel pain on the left side. When she consulted us five days later, the left ankle and foot were diffusely swollen and warm. The findings of the stand on heel test and the calcaneal squeeze test were both positive. Radiographs of the heel at that time demonstrated no abnormal findings (Fig. 2-A). We recommended limited and protected weight-bearing on the heel. Two weeks later, repeat radiographs demonstrated a sclerotic line traversing the calcaneus (Fig. 2-B). One month after the onset of heel pain, the local heat and swelling had almost completely subsided and the findings of the stand on heel test and the squeeze test were negative. DXA bone mineral densitometry of the left femoral neck, measured at twenty-six weeks postoperatively, was 0.386 g/cm2, the T-score was 23.7, and the Z-score was 21.6. Treatment for osteoporosis with parathyroid hormone was initiated at six months postoperatively. A DXA scan performed at seventeen months postoperatively on the left radius showed bone mineral density of 0.388 mg/cm2; the T-score was 25.4, and the Z-score was 20.8. The third patient, an eighty-four-year-old woman (Case 3) with osteoarthritis of both knees, underwent total knee arthroplasty of the right knee followed by total knee arthroplasty of the left knee twenty-six weeks later. Following the second
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CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
TABLE I Patient Demographics, Time of Fracture After Arthroplasty, Clinical Signs and Test Results, Linear Sclerosis of the Calcaneus on the Initial Radiograph, and Bone Mineral Density Case
Age (yr) Sex Postop. timing of appearance of clinical signs (wk)
1
2
3
4
5
76
77
84
68
79
F
F
F
F
F
6
23
6
10
6
Swelling*
1
1
1
2
1
Local heat*
1
1
2
2
1
Stand on heel test*
1
1
1
1
1
Squeeze test*
1
1
1
1
1
Linear sclerosis on initial radiograph Bone mineral density of the femoral neck (g/cm2) T-score Z-score
1
2
1
2
1
0.464 22.51 20.90
0.386 23.7 21.6
0.389 23.7 21.5
0.513 22.5 20.5
0.477 22.8 20.5
*The plus sign indicates a positive finding, and a minus sign indicates a negative finding.
arthroplasty, the postoperative course was initially uneventful, but pain suddenly developed in the left heel at six weeks postoperatively. When she consulted us one week later, the left ankle was diffusely swollen and the stand on heel and squeeze tests were both positive. Radiographs demonstrated a slightly sclerotic line traversing the upper portion of the calcaneal tuberosity (Fig. 3-A). A calcaneal stress fracture was suspected, and she was instructed to limit weight-bearing activity and use a cane. Three weeks later, the swelling had subsided nearly completely, but she still had heel pain and the squeeze test was
Fig. 2-A
positive. A radiograph made at that time demonstrated a sclerotic line in the calcaneal tuberosity (Fig. 3-B). Thirteen weeks postoperatively, the findings of the stand on heel test and the squeeze test were both negative. A DXA scan carried out thirteen months postoperatively showed bone mineral density in the femoral neck of 0.389 g/cm2; the T-score was 23.7, and the Z-score was 21.5. In the distal end of the radius, the bone mineral density was 0.467 g/cm2; the T-score was 23.8, and the Z-score was 0.9. The fourth patient (Case 4), a sixty-eight-year-old woman with bilateral knee arthritis, underwent a right total
Fig. 2-B
Figs. 2-A and 2-B Case 2. Fig. 2-A There is no abnormal finding on this radiograph of the calcaneus made twenty-four weeks after total knee arthroplasty and five days after the onset of symptoms. Fig. 2-B The sclerotic line (arrows) had become apparent two weeks later.
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Fig. 3-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 3-B
Figs. 3-A and 3-B Case 3. Fig. 3-A There is only a slight sclerotic line (arrows) in the calcaneus on this radiograph made seven weeks after total knee arthroplasty and one week after the onset of symptoms. Fig. 3-B The sclerotic line (arrows) had become more apparent three weeks later.
knee arthroplasty. Acute pain developed in the right heel ten weeks postoperatively. When she consulted us five days later, there was no apparent swelling or local heat around the ankle. The stand on heel test and the calcaneal squeeze test were both positive. Radiographs demonstrated no abnormal findings of the calcaneus (Fig. 4-A). With a tentative diagnosis of a calcaneal stress fracture, we advised her to avoid weight-bearing. Two weeks later, the heel pain had subsided and she could bear weight on the
Fig. 4-A
affected heel. A radiograph demonstrated a sclerotic line traversing the calcaneal tuberosity (Fig. 4-B). When seen seven months postoperatively, she had no heel pain. Bone mineral density of the right femoral neck, measured at thirty-seven weeks postoperatively, was 0.513 g/cm2; the T-score was 22.5, and the Z-score was 20.5. The last patient (Case 5) was a remarkably strong seventynine-year-old woman who underwent a right total hip arthroplasty
Fig. 4-B
Figs. 4-A and 4-B Case 4. Fig. 4-A There are no abnormal findings of the calcaneus on the radiograph made eleven weeks after total knee arthroplasty and five days after the onset of symptoms. Fig. 4-B A sclerotic line (arrows) had become apparent in the calcaneal tuberosity two weeks later.
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Fig. 5-A
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
Fig. 5-B
Figs. 5-A and 5-B Case 5. Fig. 5-A A sclerotic line (arrows) traverses the long axis of the calcaneal tuberosity at seventeen weeks after total hip arthroplasty and five weeks after the onset of symptoms. Fig. 5-B T1-weighted magnetic resonance imaging clearly demonstrates a linear zone of low signal intensity (arrows), which indicated a fracture line, and a broader, poorly defined area of signal intensity alteration in the bone marrow.
and started bearing full weight on the operatively treated side on the day after surgery. She returned to light farm work three weeks later. About six weeks postoperatively, she developed acute pain in the right heel and the ankle was markedly swollen and warm. The stand on heel test and the calcaneal squeeze test were both positive. She was advised to avoid weight-bearing, and the pain, swelling, and local heat had subsided by twelve weeks postoperatively. Radiographs made seventeen weeks postoperatively revealed a sclerotic line traversing the calcaneal tuberosity (Fig. 5-A). Magnetic resonance imaging demonstrated a fracture line with bone marrow edema surrounding the fracture (Fig. 5-B). The squeeze test continued to have slightly positive findings at eighteen weeks postoperatively. Bone mineral density of the femoral neck, measured at fifteen weeks postoperatively, was 0.477 g/cm2; the T-score was 22.8, and the Z-score was 20.5. She started osteoporosis treatment with bisphosphonates five months postoperatively. Discussion tress fractures of the femoral neck2-8, pubis1, proximal part of the tibia9-11, and fabella12 have been reported following total knee arthroplasty, while stress fractures of the pubis have been reported following total hip arthroplasty13-16. Calcaneal stress fracture following joint replacement, to our knowledge, has not been previously reported in the English-language literature. Calcaneal stress fractures are commonly seen in the healthy bone of military recruits17-23. However, all five patients in this study were osteoporotic; the bone mineral content of the femoral neck in the five patients was 57%, 49%, 49%, 65%, and 61%, respectively, of the mean value in young adults. Calcaneal insufficiency fractures occur in bones having less than normal elastic resistance to compression and stretching. They occur in elderly individuals with osteoporosis without any antecedent
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trauma or overuse24,25 and are not commonly recognized24-30. The cases of two patients reported by Ito et al.24, the cases of six patients reported by Alonso-Bartolome et al.25, and the five patients in the present report are the best examples in the literature. A calcaneal insufficiency fracture might occur more readily after joint replacement surgery because the mechanical stresses on the operatively treated limb may increase considerably as a result of pain relief in the early postoperative period following the arthroplasty26,27. DXA scans of the distal end of the radius were carried out in addition to scans of the femoral neck in four patients (Cases 2, 3, 4, and 5) to distinguish generalized osteoporosis from disuse osteoporosis of the lower extremity. However, we could not arrive at a clear-cut conclusion about the type of osteoporosis. Bone mineral content was decreased in the femoral neck and in the distal end of the radius to the same degree in one patient (Case 3), while it was disproportionately decreased more in the femoral neck in another patient (Case 4) and in the distal end of the radius in two patients (Cases 2 and 5). We carried out 516 arthroplasties (409 total knee arthroplasties and 107 total hip arthroplasties) at our current hospital over the six years since 2007. We encountered no calcaneal stress fractures except those in the five patients described in the present report. Thus, the overall rate of calcaneal stress fracture has been less than 1% over that six-year period. The fractures in four patients (Cases 2, 3, 4, and 5) occurred during one seven-month period, during which we performed twenty-eight total knee arthroplasties (nineteen in female patients and nine in male patients) and five total hip arthroplasties (all female patients), creating an incidence of 12% during those seven months. Our operative technique and postoperative physiotherapy routine did not change remarkably during that time, and we cannot identify any reason for this substantial increase in the number
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of calcaneal stress fractures. Perhaps these insufficiency fractures following joint replacement surgery are more common than appreciated. They can be easily overlooked unless suspected, and both Ito et al.24 and Alonso-Bartolome et al.25 stated that often they might be underrecognized and mistaken for other conditions. All five stress fractures in this series occurred on the same side as the arthroplasty. Following surgery, the operatively treated limb, relieved of preoperative pain, perhaps became the main supporting limb, and the increased mechanical stress might have been the cause of the fracture in at least some of the patients. It is unknown why all thirteen patients in both the present report and the reports by Ito et al.24 and by Alonso-Bartolome25 were female. In part, it may be because osteoporosis occurs more frequently in females, and nearly 80% of the candidates for joint replacement in our hospital are female. Orthopaedic surgeons should be aware of the potential adverse event of a calcaneal insufficiency stress fracture following total knee arthroplasty or total hip arthroplasty, especially in osteoporotic women. The symptoms in our patients appeared at a mean of ten weeks (range, six to twenty-three weeks) postoperatively. The patients all complained of heel pain and could not bear weight on the affected heel. Swelling, local heat, or redness around the heel were not always present, but the results of the stand on heel test and the squeeze test were positive in all patients. The diagnosis is primarily a clinical one as early radiographic
CALCA NE AL STRES S FRACTURE : AN ADVE RSE EV EN T FO LLOW I N G T O TA L H I P A N D T O TA L K N E E A R T H R O P L A S T Y
features are absent or subtle. In our patients, the typical irregular sclerotic line traversing the calcaneus22 appeared radiographically between seven and thirty-one days after the onset of clinical signs and symptoms. The patient needs no special treatment but should avoid weight-bearing until the pain disappears. This typically takes approximately one month. Fracture displacement is rare, but it occurred in one patient (Case 1) with moderate but asymptomatic dorsal displacement of the tuberosity fragment. n
Takaaki Miki, MD, PhD Akihiro Nishiyama, MD Department of Orthopedic Surgery, Unnan Municipal Hospital, Iida 96-1, Daito Town, Unnan City, Shimane Prefecture 699-12, Japan. E-mail address for T. Miki: [email protected]. E-mail address for A. Nishiyama: [email protected] Takahito Miki, MD Miki Orthopedic and Pain Clinic, Kandachi 706, Aikawa, Hikawa-Town, Izumo City, Shimane Prefecture 699-0615, Japan. E-mail: [email protected]
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16. Oh I, Hardacre JA. Fatigue fracture of the inferior pubic ramus following total hip replacement for congenital hip dislocation. Clin Orthop Relat Res. 1980 Mar-Apr;(147):154-6. 17. Greaney RB, Gerber FH, Laughlin RL, Kmet JP, Metz CD, Kilcheski TS, Rao BR, Silverman ED. Distribution and natural history of stress fractures in U.S. Marine recruits. Radiology. 1983 Feb;146(2):339-46. 18. Darby RE. Stress fractures of the os calcis. JAMA. 1967 Jun 26;200(13): 1183-4. 19. Hopson CN, Perry DR. Stress fractures of the calcaneus in women marine recruits. Clin Orthop Relat Res. 1977 Oct;(128):159-62. 20. Giladi M, Alcalay J. Stress fracture of the calcaneus—still an enigma in the Israeli Army. JAMA. 1984 Dec 14;252(22):3128-9. 21. Hullinger CW. Insufficiency fracture of the calcaneus. Similar to march fracture of the metatarsal. J Bone Joint Surg. 1944;26:751-7. 22. Leabhart JW. Stress fractures of the calcaneus. J Bone Joint Surg Am. 1959 Oct;41:1285-90. 23. Sormaala MJ, Niva MH, Kiuru MJ, Mattila VM, Pihlajam¨aki HK. Stress injuries of the calcaneus detected with magnetic resonance imaging in military recruits. J Bone Joint Surg Am. 2006 Oct;88(10):2237-42. 24. Ito K, Hori K, Terashima Y, Sekine M, Kura H. Insufficiency fracture of the body of the calcaneus in elderly patients with osteoporosis: a report of two cases. Clin Orthop Relat Res. 2004 May;(422):190-4. 25. Alonso-Bartolome P, Blanco R, Canga A, Martı´nez-Taboada VM. Insufficiency fractures of the calcaneus: a diagnostic pitfall for ankle arthritis. J Rheumatol. 2006 Jun;33(6):1140-2. 26. van Loon CJM, Oyen WJG, de Waal Malefijt MC, Verdonschot N. Distal femoral bone mineral density after total knee arthroplasty: a comparison with general bone mineral density. Arch Orthop Trauma Surg. 2001 May;121(5):282-5. 27. Liu TK, Yang RS, Chieng PU, Shee BW. Periprosthetic bone mineral density of the distal femur after total knee arthroplasty. Int Orthop. 1995;19(6):346-51. 28. Daffner RH, Pavlov H. Stress fractures: current concepts. AJR Am J Roentgenol. 1992 Aug;159(2):245-52. 29. Buchanan J, Greer RB 3rd. Stress fractures in the calcaneus of a child. A case report. Clin Orthop Relat Res. 1978 Sep;(135):119-20. 30. Stein RE, Stelling FH. Stress fracture of the calcaneus in a child with cerebral palsy. J Bone Joint Surg Am. 1977 Jan;59(1):131.
