Femoral head osteonecrosis in pediatric and young adult patients with leukemia or lymphoma

Osteonecrosis in children after allogeneic hematopoietic cell transplantation: study of prevalence, risk factors and longitudinal changes using MR imaging

Osteonecrosis after hematopoietic SCT (HCT) has seldom been addressed in pediatric populations. At our institution, since January 2002, children undergoing allogeneic HCT (alloHCT) receive yearly follow-up magnetic resonance imaging (MR) of hips and knees. To estimate the prevalence, longitudinal changes and associated risk factors for osteonecrosis after alloHCT, we reviewed MRs for children who underwent single alloHCT during the study period. We analyzed 149 of 344 patients who had post-HCT MR imaging performed (84 males; median age 11 years (range, 0.5-21 years)), median follow-up time was 32.6 months (range, 2.8-97.2 months). In all, 44 (29.5%) developed osteonecrosis of hips and/or knees; of those, 20 (45%) had at least 30% epiphyseal involvement. In 23 (52%), osteonecrosis lesions were identified in the first and in 43 (98%) by the third yearly scan. Knees were more frequently involved than hips; severity of osteonecrosis was greater in hips. Those who had pre-alloHCT osteonecrosis, two patients' hips and six patients' knees resolved completely; three patients' osteonecrosis lesions regressed after alloHCT. On risk factor analysis, age at time of alloHCT (P=0.051) and osteonecrosis identified by MRs before alloHCT (P=0.001) were the primary risk factors. This analysis shows that preventive strategies for osteonecrosis in this population should focus on measures to minimize risk factors before alloHCT.

Osteonecrosis in children after allogeneic hematopoietic cell transplantation: study of prevalence, risk factors and longitudinal changes using MR imaging

Osteonecrosis after hematopoietic stem cell transplantation (HCT) has seldom been addressed in pediatric populations. At our institution, since January 2002, children undergoing allogeneic HCT (alloHCT) receive yearly follow-up magnetic resonance imaging (MR) of hips and knees. To estimate the prevalence, longitudinal changes and associated risk factors for osteonecrosis after alloHCT, we reviewed MRs for children who underwent single alloHCT during the study period. We analyzed 149 of 344 patients who had post HCT MRI imaging performed [84 males; median age11 years (range, 0.5–21years)], median follow-up time was 32.6 months (range, 2.8–97.2 months). Forty-four (29.5%) developed osteonecrosis of hips and/or knees; of those, 20 (45%) had at least 30% epiphyseal involvement. In 23 (52%) osteonecrosis lesions were identified in the first, and 43 (98%) by the third yearly scan. Knees were more frequently involved than hips; severity of osteonecrosis was greater in hips. Those who had pre-alloHCT osteonecrosis, two patients’ hips and six patients’ knees resolved completely; three patients’ osteonecrosis lesions regressed after alloHCT. On risk factor analysis, age at time of alloHCT (p=0.051) and osteonecrosis identified by MRs before alloHCT (p=0.001) were the primary risk factors. This analysis shows that preventive strategies for osteonecrosis in this population should focus on measures to minimize risk factors before alloHCT.

Management of osteonecrosis in children and young adults with acute lymphoblastic leukaemia

Osteonecrosis is a disabling complication in children and young adults with acute lymphoblastic leukaemia. It can affect any or multiple joints but the hip and knee are most frequently involved and a cause of long-term disability. The problem is almost exclusively that of older children and young adults of whom over 70% have asymptomatic changes on screening magnetic resonance imaging and 15-20% have resulting symptoms. Dexamethasone is associated with a higher risk than prednisolone in US but not European or UK trials and alternate week scheduling of dexamethasone in the intensification course is associated with a lower risk than a continuous 3-week schedule in US trials. Genetic factors and obesity contribute to the risk, as do metabolic abnormalities caused by drugs, such as asparaginase, which increase tissue exposure to steroids. Management is primarily supportive but a minority of patients require surgical intervention including replacement of the affected joint. A variety of surgical techniques and, latterly, bisphophonates, have been tried to prevent progression but their efficacy remains uncertain. Whether patients should continue to receive steroids after diagnosis of osteonecrosis is uncertain but most trial investigators recommend stopping them after completion of the intensification phase of treatment.

Osteonecrosis in children after therapy for malignancy

OBJECTIVE

Osteonecrosis in the growing population of childhood cancer survivors results from disease and treatment. Imagers must be knowledgeable about patient groups at risk for its development, patterns of involvement and potential implications. This review will focus on implications of this potentially life-altering toxicity.

CONCLUSION

Childhood cancer survivors are at increased risk for developing osteonecrosis. Because osteonecrosis is often asymptomatic until late in the process, imaging is critical for its detection and characterization when interventions may be most effective to ameliorate its progression.

Recent research advances in childhood acute lymphoblastic leukemia

Recent progress in risk-adapted treatment for childhood acute lymphoblastic leukemia has secured 5-year event-free survival rates of approximately 80% and 5-year survival rates approaching 90%. With improved systemic and intrathecal chemotherapy, it is now feasible to omit safely in all patients prophylactic cranial irradiation, which was once a standard treatment. As high-resolution, genome-wide analyses of leukemic and normal host cells continue to identify novel subtypes of lymphoblastic leukemia and provide new insights into leukemogenesis, we can look forward to the time when all cases of this disease will be classified according to specific genetic abnormalities, some of which will yield "druggable" targets for more effective and less toxic treatments. Meanwhile, it is sobering to consider that a significant fraction of leukemia survivors will develop serious health problems within 30 years of their initial diagnosis. This underlines the need to introduce early countermeasures to reduce late therapy-related effects. The ultimate challenge is to gain a clear understanding of the factors that give rise to childhood leukemia in the first place, and enable preventive strategies to be devised and implemented.

Pharmacokinetic, pharmacodynamic, and pharmacogenetic determinants of osteonecrosis in children with acute lymphoblastic leukemia

Osteonecrosis is a severe glucocorticoid-induced complication of acute lymphoblastic leukemia treatment. We prospectively screened children (n = 364) with magnetic resonance imaging of hips and knees, regardless of symptoms; the cumulative incidence of any (grade 1-4) versus symptomatic (grade 2-4) osteonecrosis was 71.8% versus 17.6%, respectively. We investigated whether age, race, sex, acute lymphoblastic leukemia treatment arm, body mass, serum lipids, albumin and cortisol levels, dexamethasone pharmacokinetics, and genome-wide germline genetic polymorphisms were associated with symptomatic osteonecrosis. Age more than 10 years (odds ratio, = 4.85; 95% confidence interval, 2.5-9.2; P = .00001) and more intensive treatment (odds ratio = 2.5; 95% confidence interval, 1.2-4.9; P = .011) were risk factors and included as covariates in all analyses. Lower albumin (P = .05) and elevated cholesterol (P = .02) associated with symptomatic osteonecrosis, and severe (grade 3 or 4) osteonecrosis was linked to poor dexamethasone clearance (P = .0005). Adjusting for clinical features, polymorphisms of ACP1 (eg, rs12714403, P = 1.9 × 10(-6), odds ratio = 5.6; 95% confidence interval, 2.7-11.3), which regulates lipid levels and osteoblast differentiation, were associated with risk of osteonecrosis as well as with lower albumin and higher cholesterol. Overall, older age, lower albumin, higher lipid levels, and dexamethasone exposure were associated with osteonecrosis and may be linked by inherited genomic variation.

Glucocorticoid use in acute lymphoblastic leukaemia

Glucocorticoids (prednisone and dexamethasone) play an essential part in the treatment of acute lymphoblastic leukaemia (ALL), but their optimum doses and bioequivalence have not been established. Results of preclinical studies have shown that dexamethasone has a longer half-life and better CNS penetration than does prednisone. In prospective randomised trials, dexamethasone improved control of CNS leukaemia. At a prednisone-to-dexamethasone dose ratio of less than seven, dexamethasone (6-18 mg/m(2) per day) resulted in a better event-free survival than did prednisone (40-120 mg/m(2) per day), and high-dose dexamethasone (10-18 mg/m(2) per day) improved the outcome of T-cell ALL and high-risk ALL. However, dexamethasone caused more adverse effects, including infection, bone fracture, osteonecrosis, mood and behaviour problems, and myopathy. At a dose ratio greater than seven, the two drugs showed no difference in efficacy. Therefore, the efficacy of prednisone and dexamethasone is dose dependent and needs to be carefully assessed against the toxic effects. Moreover, although dexamethasone generally showed increased activity in ALL cells in vitro, the dose ratio of the two drugs that exerted equivalent cytotoxic effects differed substantially in samples from individuals. The selection of the type and dose of glucocorticoid should be based on the risk of relapse, treatment phase, and the chemotherapeutic drugs used concomitantly.

Prevalence of osteonecrosis and associated risk factors in children before allogeneic BMT

Osteonecrosis (ON) is a debilitating long-term complication of allogenic bone marrow transplantation (alloBMT) but may begin before alloBMT in some children because of their primary disease treatment. Therefore, to estimate the prevalence and associated risk factors for ON before alloBMT, we conducted a retrospective analysis of magnetic resonance (MR) studies of 118 children who underwent first alloBMT at our institution between December 2000 and September 2007. Of the 118 consecutive patients, 107 (90.7%) underwent prospective MR studies irrespective of symptoms (69 males; median age at alloBMT 12.9 years), and 11 underwent MR studies for symptoms. Amongst the 107 who had prospective imaging, 23 (21.5%) had ON; nearly 50% had at least 30% epiphyseal involvement. Knees were more frequently involved than were hips; severity of ON was greater in hips. ON prevalence before alloBMT was 23.72% when all 118 patients were included in the denominator. Risk factor analysis, limited to MR studies performed irrespective of symptoms, revealed female gender (P = 0.049) and age ≥10 years at the time of MR study (P = 0.03) as significant risk factors and primary diagnosis of lymphoid malignancies and aplastic anemia trended towards significance. ON prior to alloBMT is a common occurrence in children.

How does osteonecrosis about the knee progress in young patients with leukemia?: a 2- to 7-year study

BACKGROUND

Osteonecrosis is a major treatment complication of pediatric leukemias owing to its potential to cause joint deterioration. Because of potential long-term effects of osteonecrosis on joints, information regarding its progression and collapse in different patients can be used to identify high-risk groups, advise the patients and parents of this complication, and potentially consider the risk for development of osteonecrosis in planning primary treatment.

QUESTIONS/PURPOSES

We therefore determined: (1) the incidence of joint collapse and/or pain in young patients with hematologic malignancies diagnosed with ON of the knee; (2) risk factors associated with collapse; and (3) the relationship between size and location of osteonecrotic knee lesions and the likelihood of joint collapse.

PATIENTS AND METHODS

We retrospectively reviewed 109 patients with hematologic malignancies and MRI-confirmed knee osteonecrosis. The median age was 11.5 years (range, 2.3-18.8 years) at primary diagnosis of hematologic malignancy and a median age of 13.4 years (range, 2.7-23.3 years) at diagnosis of osteonecrosis of the knee. For analyses, we used the first and last MR images. Minimum clinical followup was 2.3 years after diagnosis of knee osteonecrosis (median, 6 years; range, 2.3-7.17 years).

RESULTS

Joint collapse occurred in 22% (24 of 109). Older age, pain at osteonecrosis presentation, and lesions extending to the articular surface of distal femoral epiphyses were associated with joint collapse.

CONCLUSIONS

Younger patients and those without extensive femoral epiphyseal involvement have a better prognosis for osteonecrosis of the knee.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Proteomic analysis of bone tissues of patients with osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is a devastating disease that can result in a femoral head collapse. By proteomics analysis, we identified 1,967 proteins with two or more unique peptides from ONFH and from control bones with a false discovery rate of 4.8%. Using spectral counting, we identified 141 overexpressed and 56 underexpressed proteins comparing ONFH bones to the controls. GSEA (gene set enrichment analysis) revealed that proteins overexpressed in ONFH are enriched for gene sets related to multiple myeloma and adult T-cell lymphoma (ATL), and to JAK2-dependent genes. We confirmed the underexpression of CHST2 (isoform 1 of carbohydrate sulfotransferase 2), a key protein involved in biosynthesis of chondroitin sulfate proteoglycans, and the underexpression of GPCR26 (G-protein coupled receptor 26), a protein that mediates intracellular calcium mobilization, in ONFH bones compared to controls. Taken together, our data suggest that biosynthesis of chondroitin sulfate proteoglycans and cation transport and mobilization may be a key process involved in the pathogenesis of ONFH. Our analysis sheds new light on the understanding of the pathogenesis of ONFH.

Transtrochanteric anterior rotational osteotomy for osteonecrosis of the femoral head in patients 20 years or younger

BACKGROUND

For young patients with osteonecrosis of the femoral head, especially those younger than 20 years, a joint-preserving operation may be one of the surgical treatment options to be considered. We investigated the clinical and radiological results of transtrochanteric anterior rotational osteotomy for the treatment of osteonecrosis of the femoral head in patients 20 years or younger.

METHODS

Between 1976 and 2001, a transtrochanteric anterior rotational osteotomy was performed in 28 hips of 23 patients aged 20 years or younger with osteonecrosis of the femoral head. Among them, 27 hips of 22 patients with a minimum follow-up duration of 2 years were investigated (follow-up rate, 96.4%). They included 7 males and 15 females with a mean age of 16 years at the time of surgery. The mean follow-up period was 14.7 years (range, 2.0-31.7 years). The clinical assessment was made based on the Merle d'Aubigné-Postel score. The postoperative intact ratio, joint-space narrowing, and progression of collapse were all investigated radiographically.

RESULTS

Two (7.4%) of the 27 hips required total hip arthroplasty because of restrictions in the range of motion, whereas the original hip joints in 25 (92.6%) of the 27 hips were preserved at the time of final follow-up. The mean preoperative Merle d'Aubigné-Postel score was 10.4 points, which improved to 15.9 points at the final follow-up (P < 0.0001). The mean postoperative intact ratio was 49.8% (range, 30-100). Five (18.5%) of the 27 hips had a progressive joint-space narrowing, but progression of the collapse was not observed in anyhips.

CONCLUSIONS

Transtrochanteric anterior rotational osteotomy appears to be a useful joint-preserving operation for patients younger than 20 years.

LEVEL OF EVIDENCE

Level 4 (Therapeutic Study).

Thorough debridement under endoscopic visualization with bone grafting and stabilization for femoral head osteonecrosis in children

BACKGROUND

Osteonecrosis of the femoral head has become increasingly common after steroid therapy and as a consequence of improved survival in children with sickle cell anemia and leukemia. Multiple operative and nonoperative treatments have been explored in the pediatric patient population, and core decompression is a relatively safe and possibly effective option. To optimize core decompression further, we have tested a new technique involving thorough decompression of the osteonecrotic zone under endoscopic visualization (TDEV) combined with cancellous bone grafting and stabilization with a nail plate device.

METHODS

We retrospectively reviewed 16 hips in 13 patients (< or =20 years old) with femoral head osteonecrosis related to steroid treatment, sickle cell anemia, or leukemia. The Steinberg classification system was used to classify all cases. Each patient underwent TDEV, bone grafting, and stabilization of the grafting site. Patients were followed up postoperatively for changes in pain level, functional ability, and Steinberg radiologic stage.

RESULTS

The mean follow-up was 28 months (range, 18-49 months). All patients in whom the procedure was successful had improvement in pain symptoms at latest follow-up, except for 1. Radiologically, all Steinberg stage II cases (B and C), except for 1, demonstrated good incorporation of graft without further progression of disease. Seven of the 8 patients that showed radiologic progression and deterioration of function or progressive symptoms had grade IIIB disease or higher at the time of procedure.

CONCLUSIONS

Our initial results demonstrate that TDEV combined with cancellous bone grafting and stabilization produces encouraging early results for pediatric patients with lesions graded lower than Steinberg stage IIIB. Our findings were less optimistic for patients with higher-grade lesions. Our recommendation, therefore, is to use TDEV by trained surgeons for treatment of early-stage lesions, preferably less than Steinberg stage IIIB.

LEVEL OF EVIDENCE

Level IV, Therapeutic Study.

Promoting physical activity in childhood cancer survivors: results from the Childhood Cancer Survivor Study

BACKGROUND

Although physical activity may modify the late effects of childhood cancer treatment, from 20% to 52% of adult survivors are sedentary. The authors of this report sought to identify modifiable factors that influence survivors' participation in physical activity.

METHODS

Structural equation modeling of data were derived from the Childhood Cancer Survivors Study of adult survivors (current mean age, 30.98 years; mean years since diagnosis, 23.74; mean age at diagnosis, 9.25 years) who were diagnosed between 1970 and 1986.

RESULTS

Approximately 40% of the variance in male survivors' recent participation versus nonparticipation in physical activity was explained directly and/or indirectly by self-reported health fears (P = .01), perceived primary-care physician (PCP) expertise (P = .01), baseline exercise frequency (P < or = .001), education level (P = .01), self-reported stamina (P = .01), cancer-related pain (P < or = .001), fatigue (P < or = .001), age at diagnosis (P = .01), cancer-related anxiety (P < or = .001), motivation (P = .01), affect (P = .01), and discussion of subsequent cancer risk with the PCP (P < or = .001) (N = 256; chi-square test statistic = 53.38; degrees of freedom [df] = 51; P = .38, Comparative Fit Index [CFI] = 1.000; Tucker Lewis Index [TLI] = 1.000; root mean square of approximation [RMSEA] = 0.014; weighted root mean square residual [WRMR] = 0.76). Thirty-one percent of the variance in women' recent physical activity participation was explained directly and/or indirectly by self-reported stamina (P < or = .001), fatigue (P = .01), baseline exercise frequency (P = .01), cancer-related pain (P < or = .001), cancer-related anxiety (P = .01), recency of visits with PCP (<0.001), quality of interaction with the PCP (P = .01), and motivation (P < or = .001; N = 366; chi-square test statistic = 67.52; df = 55; P = .12; CFI = 0.98; TLI = 0.98; RMSEA = 0.025; WRMR = 0.76).

CONCLUSIONS

Gender-tailored intervention strategies in which providers specifically target motivation, fear, and affect may support physical activity in childhood cancer survivors.

Femoral resurfacing in young patients with hematologic cancer and osteonecrosis

Resurfacing hemiarthroplasties were performed to treat advanced osteonecrosis of 20 femoral heads in 14 patients (median age, 19.8 years; range, 15.1-27.4 years), treated for hematologic cancer in childhood or adolescence. Seven hips in five patients were revised to total hip arthroplasties (THA) because of pain; three of these showed radiographic loosening of the femoral head resurfacing component. The median time from resurfacing to revision was 2.4 years (range, 0.9-4.8 years). Marginal Cox-regression analysis, adjusting for correlations owing to bilateral involvement, showed positive association of revision-free survival of the prosthesis with patient's age; time from resurfacing to the end of anticancer therapy, end of glucocorticosteroid therapy; percentage of joint space at the last radiograph; and size of the lesion has a negative association with revision-free survival. Because of this study's exploratory nature, p values were not adjusted for the number of statistical comparisons. Among 14 patients, the probability of not requiring resurfacing prosthesis revision was 66% (SE, +/-15%; 95% CI, 44%-100%) at 3 years. Osteonecrosis of the femoral head in young patients treated for hematologic cancer in childhood or adolescence poses a serious challenge to the orthopaedic surgeon. The data of this preliminary study suggest that in selected patients resurfacing hemiarthroplasty may delay the need for THA for 3-7 years.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Osteonecrosis in Adult Survivors of Childhood Cancer: A Report From the Childhood Cancer Survivor Study

Purpose

Osteonecrosis (ON) is a potentially serious complication of therapy in survivors of childhood cancer. Our goals were to describe the incidence of ON and identify patient and treatment characteristics associated with elevated risk.

Patients and Methods

The rate of self-reported ON was determined for 9,261 patients enrolled onto the Childhood Cancer Survivor Study, a cohort of 5-year survivors of childhood cancer diagnosed from 1970 to 1986, and compared with the rate in a random sample of 2,872 siblings of survivors. Survivors with positive responses were reinterviewed to confirm the diagnosis.

Results

Fifty-two cancer survivors reported ON in 78 joints, yielding 20-year cumulative incidence of 0.43% and a rate ratio (RR) of 6.2 (95% CI, 2.3 to 17.2) compared with siblings, adjusted for age and sex; 44% developed ON in a previous radiation field. The RR was greatest among survivors of stem-cell transplantation for acute lymphoblastic leukemia (ALL), acute myelogenous leukemia (AML), and chronic myelogenous leukemia (RR = 26.9, 66.5, and 93.1, respectively). Nontransplantation patients with ALL (RR = 6.5; 95% CI, 2.2 to 19.4), AML (RR = 11.2; 95% CI, 2.1 to 61.2), and bone sarcoma (RR = 7.3; 95% CI, 2.0 to 26.2) were at higher risk for ON. Older age at diagnosis, shorter elapsed time, older treatment era, exposure to dexamethasone (± prednisone), and gonadal and nongonadal radiation were independently associated with ON.

Conclusion

ON among long-term survivors of childhood cancer is rare. However, compared with siblings, childhood cancer survivors have a significantly increased relative rate of ON, particularly those who were older at diagnosis and who received dexamethasone or radiation therapy. Future studies are needed to better delineate our findings, particularly the increased risk after gonadal radiation.

On a case of multifocal osteonecrosis in a patient suffering from acute lymphoblastic leukemia

The Authors describe the case of a 14-year-old girl who developed a multifocal osteonecrosis (ON), after treatment with chemotherapy and corticosteroids for acute lymphoblastic leukemia (ALL). She came to our attention about 6 months after the beginning of treatment complaining of pain in her left knee and later in both hips and shoulders. Radiography and MRI confirmed the presence of avascular ON at all these sites. The patient underwent bilateral total hip arthroplasty, which was still functioning well at the last follow-up visits at 5 years, and at 5 years and 4 months. ON is increasingly recognized as a complication of the treatment of cancer in children and adolescents, and as patients now frequently survive ALL into adulthood, orthopedists will be increasingly called on to manage this complication affecting multiple joints in children and young adults.