Core Decompressions Research Articles

Femoral Head Core Decompressions: Characterization of Subsequent Conversion to Total Hip Arthroplasty and Related Complications.

Core decompression is a minimally invasive joint-preserving approach for early-stage osteonecrosis. The rate at which core decompression patients require total hip arthroplasty (THA) and rates of perioperative adverse outcomes have not been well-characterized. Adult patients undergoing core decompression and/or THA with osteonecrosis of the femoral head were identified from the 2015 to 2021 Q3 PearlDiver M157 database. Those undergoing THA without or with antecedent core decompression were identified and matched 4:1 on age, sex, and Elixhauser Comorbidity Index. Postoperative 90-day adverse events were compared with multivariable analysis. Five-year rates of revision, dislocation, and periprosthetic fracture were compared by the Kaplan-Meier curve and log-rank tests. Core decompressions were identified for 3,025 patients of whom 387 (12.8%) went on to THA within 5 years (64% within the first year). The median time from initial core decompression to THA was 252 days. For THA, 26,209 adults were identified and 387 had prior core decompression. After matching, there were 1,320 without core decompression and 339 with core decompression. No statistically significant differences were observed in 90-day postoperative adverse events or 5-year rates of revision, dislocation, or periprosthetic fracture. Core decompression may be an option for patients with osteonecrosis and does not seem to affect THA outcomes if required later.

Poster 222: High Rates of Conversion to Total Hip Arthroplasty After Core Decompression for Avascular Necrosis of the Hip

Objectives: Avascular necrosis (AVN) of the hip is caused by interruption of blood flow to the femoral head, resulting in pain, loss of joint function, and eventual hip arthritis. Core decompression may be performed for early AVN with a goal of improving symptoms and potentially delaying the need for THA. The effectiveness of this procedure is generally not well understood given the relatively rare nature of hip AVN. The predictors of conversion to THA after core decompression are not well defined. Core decompression is also not without potentially devastating complications, including femoral neck fractures, though estimation of true incidence of complications has been limited by sample sizes in prior investigations. The purpose of this study is to utilize a large payor database to determine time to THA after core compression, assess predictors of early conversion to THA, and to examine complications after hip core decompressions. We hypothesize that less than 25% of patients who had a hip core decompression will convert to THA at two year follow up, we also hypothesize that age at time of core decompression will be a predictor of conversion to THA. Methods: Using Current Procedural Terminology codes, we queried the Mariner PearlDiver dataset for patients who underwent hip core decompression from 2010 to 2020. Patient demographics were recorded and subsequent THA conversion within 2 years after surgery were tracked. Patient demographic factors, including, age, sex, obesity, diabetes, prior fractures, steroid use, tobacco use, or alcohol use, were evaluated as possible predictors of early conversion to THA. International Classification of Diseases, codes were used to identify complications at 90 days and 2 years after core decompression. Multiple linear regression was used to test if the patient demographics significantly predicted conversion to THA and a Cox-Survival plot was performed. Statistical significance was defined as p<.05. Results: Between 2010-2020, 555 patients underwent hip core decompression. Within 2 years of core decompression, 209 patients converted to THA (37.6%) and one patient converted to hemiarthroplasty. Average age for patients converting to THA was 47.7 years compared to those who did not convert 43.4 (95% CI 2.1 – 6.2 years, p < .001). Most patients who converted to a THA were between age 50-59 (Figure 1). Age was the only risk factor for conversion to THA as the following variables were not associated: Sex, obesity, diabetes, prior fracture, steroid use, tobacco use, or alcohol use. Cox survival plot demonstrated a high risk of conversion to THA within two years of core decompression with the highest risk within the first 200-days (Figure 2). 90-day complication rate was 2.9% and the complication rate at 2 years was 5.2%. The most common complication was femoral neck fracture at both time points (68.7% of compilations at 90 days and 75.9% at 2 years). There was no significant difference in demographics between those that had complications and those that did not at 90 days. At 2 years after surgery patients that smoked (OR 0.39 p = .02) or had a prior fracture (OR 0.23; p = .02) were more likely to have had complications. Conclusions: There is a high failure rate following core decompression for hip AVN with over one third of patients converting to THA within 2 years. Patients older than age 50 had the highest rates of conversion to THA. While the overall complication rate is low at 90 days and 2 years, patients should be counseled regarding the risk for femoral neck fracture. Further research is needed regarding predictors of success after core decompression.

Age is predictive of higher rate of conversion to total hip arthroplasty after core decompression for osteonecrosis of the hip

BackgroundCore decompression may be performed for early osteonecrosis with a goal of improving symptoms and potentially delaying the need for total hip arthroplasty. The effectiveness and complication rate of this procedure is not well understood given the relatively rare nature of hip osteonecrosis. PurposeThe purpose of this study is to determine time to total hip arthroplasty (THA) after core compression, assess predictors of early conversion to THA, and to examine complications after hip core decompressions. MethodsUsing Current Procedural Terminology (CPT) codes, we queried the Mariner PearlDiver dataset for patients who underwent hip core decompression. Patient demographics were recorded and subsequent THA conversion within 2 years after surgery were tracked. Patient demographic factors, including age, sex, obesity, diabetes, prior fractures, steroid use, tobacco use, or alcohol use, were evaluated as possible predictors of early conversion to THA. International Classification of Diseases (ICD) codes were used to identify complications at 90 days after core decompression. Multiple linear regression was used to test if the patient demographics significantly predicted conversion to THA and complications after core decompression. ResultsBetween 2010 and 2020, 555 patients underwent hip core decompression. Within 2 years of core decompression, 226 patients converted to THA (40.7%). Age was the only significant risk factor for conversion to THA. The highest proportion of patients (61.1%, 138/226) who converted to THA were between age 40–59. The 90-day complication rate was 2.9% (16/555). The most common complication was femoral neck fracture (11/16 of all complications). DiscussionThere is a high failure rate following core decompression for hip osteonecrosis with over one third of patients converting to THA within 2 years. Age was the only variable predictive of conversion to THA. The overall complication rate after core decompression is low at 90 days. ConclusionPatients should be counseled regarding the risk of early conversion to THA if over 40 and the potential risk of femoral neck fracture.

Does augmented core decompression decrease the rate of collapse and improve survival of femoral head avascular necrosis? Case-control study comparing 184 augmented core decompressions to 79 standard core decompressions with a minimum 2 years’ follow-up

IntroductionAvascular necrosis of the femoral head often progresses to femoral head collapse if not treated. Conservative treatment yields highly variable results and is not standardised, mainly because it is typically evaluated in small patient populations. This led us to conduct a large retrospective comparative study with the goals of 1) analysing survival and functional outcomes, 2) looking for differences in survival between core decompression techniques (standard versus augmented), and 3) studying the risk factors for femoral head collapse and revision by arthroplasty. HypothesisCore decompression limits the number of patients who suffer femoral head collapse requiring arthroplasty at 2 years’ follow-up. MethodsThis multicentre, comparative, retrospective study analysed 330 patient records (1975–2016) where at least 2 years’ follow-up was available. Sixty-two patients were excluded from the analysis: 5 had a stage III with collapse, 5 were lost to follow-up, 2 died within 24 months of the procedure and 50 had incomplete data. The study included 263 patients with a mean age of 42 years (15.7–70). In the Ficat classification, there were 51 cases of stage I necrosis, 186 cases of stage II and 22 cases of stage II with crescent sign (transition stage). The Kerboull angle on radiographs was between 5° and 20° in 40 patients, between 20° and 40° in 107 patients, between 40° and 60° in 52 patients and more than 60° in 29 patients. A standard core decompression was done in 79 patients and an augmented one in 184 patients. The more severe AVN cases (stage II) were more likely to be treated by augmented CD (160/184 patients, 87%) than by standard CD (48/79 patients, 61%) (p<0.001). ResultsIn the 263 patients, the overall survival (no arthroplasty at 2 years) was 73% (196/263). At 2 years, the survival rate (without arthroplasty) was 71% (56/79) in the standard CD group versus 76% (140/184) in the augmented CD group. This difference was significant when adjusted for Ficat stage and Kerboull angle [HR=0.457, 95% CI (0.247–0.844) (p=0.012)]. When the survival data was adjusted to the Ficat stage, augmented CD was better than standard CD with 10-year survival of 58.1% vs. 57.9% (p=0.0082). More than 30% necrosis volume increased the risk of failure [HR=3.291 95%CI (1.494–7.248) (p=0.0031)]. Also, a Kerboull angle above 60° increased the risk of failure [HR=3.148 95%CI (1.346–7.5) (p=0.0083)]. ConclusionAfter 2 years, CD for non-collapsed femoral head AVN prevents collapse and revision to arthroplasty in 73% of cases (196/268). Augmented CD improves the 2-year survival and the long-term survival after adjusting for preoperative characteristics (Kerboullangle and Ficat stage). The risk of collapse and need for arthroplasty is greater in patients with 30% necrosis volume on MRI and Kerboull angle above 60°. Level of evidenceIII; retrospective case-control study.

OUTCOMES OF CORE DECOMPRESSION WITH INJECTION OF BONE MARROW ASPIRATE FOR PEDIATRIC FEMORAL HEAD OSTEONECROSIS

Background:Pediatric patients with femoral head osteonecrosis (FHON) often suffer from significant pain with decreased mobility. Once femoral head collapse occurs, few options are available short of a total hip arthroplasty (THA).[1,2] Core decompression by drilling of the femoral head is used to improve pain and prevent further femoral head collapse, however most of the literature on this technique involves adult patients.[3-5] Purpose:To date, there is no description of this technique or its outcomes in pediatric patients with FHON secondary to other etiologies other than sickle cell disease (SCD).[6] The purpose of our study is to determine outcomes in patients with FHON after undergoing core decompression with injection of bone marrow aspirate (BMA).Methods:A retrospective chart review was performed of all pediatric patients at our institution between 2007-2019 with FHON that underwent core decompression with injection of BMA. The following etiologies were identified: SCD, steroid-induced, Perthes disease (PD), slipped capital femoral epiphysis (SCFE), trauma, idiopathic, or other. To determine if core decompression with injection results in cessation of further femoral head collapse, two outcomes were assessed: Stulberg classification and number of cases that required THA. Furthermore, we evaluated whether core decompression with injection occurred in combination with any additional surgical procedure.Results:Twenty-six hips with FHON were identified with the following etiologies: 12 SCD (46.3%), 8 steroid-induced (30.8%), 2 PD (7.7%), 1 SCFE (3.8%), 1 trauma (3.8%), 1 idiopathic (3.8%), 1 other (3.8%). Mean age at the time of surgery was 12.7 years (range: 8-18). Twenty hips (76.9%) were seen in males and 6 (23.1%) were seen in females. Twenty-two hips (84.6%) were seen in black patients and 4 (15.4%) in white patients. Mean follow-up was 37.9 months (range: 0.6-77.8). Mean Stulberg classification was 3.15 (SD: 1.26). Twelve hips (46.2%) required concomitant femoral and/or pelvic osteotomies while 14 hips (53.8%) underwent core decompression with injection alone. Six hips required conversion to THA after initial core decompression and injection. All hips requiring THA were seen in patients with core decompressions and injections but no additional femoral and/or pelvic osteotomies.Conclusion:Most hips undergoing core decompression with injection did not require THA. Of the hips that required THA, all were seen in patients who only had core decompression and injection of BMA but no concomitant femoral and/or pelvic osteotomies.Figure 1.Intraoperative fluoroscopy during core decompressionFigure 2.Stulberg classificationsFigure 3.Surgical procedure and rate of conversion to THA

MRI-guidance in percutaneous core decompression of osteonecrosis of the femoral head.

The purpose of this study was to evaluate the usefulness of MRI-guidance for core decompression of avascular necrosis of the femoral head. Twelve MRI-guided core decompressions were performed on patients with different stages of avascular necrosis of the femoral head. The patients were asked to evaluate their pain and their ability to function before and after the procedure and imaging findings were reviewed respectively. Technical success in reaching the target was 100 % without complications. Mean duration of the procedure itself was 54 min. All patients with ARCO stage 1 osteonecrosis experienced clinical benefit and pathological MRI findings were seen to diminish. Patients with more advanced disease gained less, if any, benefit and total hip arthroplasty was eventually performed on four patients. MRI-guidance seems technically feasible, accurate and safe for core decompression of avascular necrosis of the femoral head. Patients with early stage osteonecrosis may benefit from the procedure. • MRI is a useful guidance method for minimally invasive musculoskeletal interventions. • Bone drilling seems beneficial at early stages of avascular necrosis. • MRI-guidance is safe and accurate for bone drilling.

Prevalence of Symptomatic Avascular Necrosis and the Operative Treatment in Adult Patients with Sickle Cell Disease

Introduction: Sickle cell disease (SCD) is complicated by widespread tissue and organ damage, including avascular necrosis (AVN) of the bones. Common sites of AVN include the shoulders and hips, which often causes severe pain and limited joint function, leading to surgical treatment. Although common, the prevalence of symptomatic AVN and optimal management for this disease has not been well defined. Furthermore, the overall effect of operative treatment on pain episodes requiring hospitalization is not known. The aim of this study is to retrospectively examine the prevalence of symptomatic AVN in adult SCD patients and assess the effects of surgical therapy.Methods: The Adult Hemoglobinopathy Resource Center at Washington University provides care for adult SCD patients throughout the St. Louis, Missouri metropolitan area. All patients have confirmed SCD (Hgb SS, Hgb SC, Hgb Sβ+, Hgb Sβ0, Hgb SC Harlem, Hgb SOther) and have been seen at least once since 2011 to be included in the study. Patients with new onset or worsening hip or shoulder pain underwent imaging studies and the presence or absence of radiographic evidence of AVN was used to determine the prevalence. The medical record was reviewed to identify patients with orthopedic procedures for AVN. The operative history of individuals with AVN was assessed and data from the post-operative hospital course was collected. The medical record was also reviewed to assess for subsequent hospitalizations and to determine whether the complications were directly related to the surgery or not. Medical record data was collected through June 2014. The surgical procedures were determined by the treating orthopedists and were not prospectively evaluated.Results: From October 2011 to June 2014, 324 patients have been evaluated. Of these patients, the mean age is 36 years (range 18-81); 180 are female (55.6%), and 144 are male (44.4%). The hemoglobinopathies include SS-205, SC-90, Sβ+-21, Sβ0-5, SC Harlem-2, and one unconfirmed genotype of SCD because of longstanding chronic transfusions. Out of the 324 patients, 94 (29%) had clinical and radiographic findings consistent with AVN of the hip(s) and 64 (19.8%) had findings consistent with AVN of the shoulder(s). No statistical difference was detected between genders (p >0.5) or among the genotypes, including between hemoglobin SS and SC (p>0.3). Forty-eight patients underwent 74 operations for AVN including 50 hip and 24 shoulder procedures. For the hip surgeries, these included 44 total hip arthroplasties, 2 hemiarthroplasties, 2 core decompressions and 2 other operative procedures. For the shoulder procedures, there were 11 total shoulder arthroplasties, 4 hemiarthroplasties, 8 core decompressions and 1 other operative treatment. All patients received pre-operative red cell transfusion support. The mean post-operative time in the hospital was 3.6 days (range <1-8) for hip surgery and 2.4 days (range <1-8) for shoulder surgery. Notably, there were thirteen re-hospitalizations within 30 days of surgery but these were all felt to be for pain syndromes not directly related to the surgical site. Fourteen patients were readmitted over the course of their care for joint-related complications resulting in 6 surgical revisions. Three had hemiarthroplasties converted to total arthroplasties, including both patients who originally received hip hemiarthroplasties. Both patients who underwent hip core decompressions later received total hip arthroplasties in those joints, and one patient of a shoulder core decompression also required total joint replacement. With three years of follow up, one patient underwent surgical removal of the prosthesis and insertion of an antibiotic spacer to treat a possible infection. Overall, patients who underwent surgical treatment for AVN had 2.4 hospitalizations per year for either joint related complications or other SCD related issues.Conclusion: SymptomaticAVN of hips and shoulders is a frequently occurring complication for patients with SCD. This data supports the role for joint replacement surgery as an effective treatment to improve joint function with a low risk of complications. However, hospitalizations for other complications of SCD, particularly sickle cell related pain, continue to occur and strategies for preventing AVN remain to be defined. DisclosuresNo relevant conflicts of interest to declare.

Avascular necrosis after chemotherapy for haematological malignancy in childhood

Avascular necrosis (AVN) is a serious complication of high-dose chemotherapy for haematological malignancy in childhood. In order to describe its incidence and main risk factors and to evaluate the current treatment options, we reviewed 105 children with a mean age of 8.25 years (1 to 17.8) who had acute lymphoblastic or acute myeloid leukaemia, or a non-Hodgkin's lymphoma. Overall, eight children (7.6%) developed AVN after a mean of 16.8 months (8 to 49). There were four boys and four girls with a mean age of 14.4 years (9.8 to 16.8) and a total of 18 involved sites, 12 of which were in the femoral head. All these children were aged > nine years (p < 0.001). All had received steroid treatment with a mean cumulative dose of prednisone of 5967 mg (4425 to 9599) compared with a mean of 3943 mg (0 to 18 585) for patients without AVN (p = 0.005). No difference existed between genders and no thrombophilic disorders were identified. Their initial treatment included 11 core decompressions and two bipolar hip replacements. Later, two salvage osteotomies were done and three patients (four hips) eventually needed a total joint replacement. We conclude that AVN mostly affects the weight-bearing epiphyses. Its risk increases with age and higher steroid doses. These high-risk patients may benefit from early screening for AVN.

Refractory osteitis condensans ilii: Outcome of a novel mini-invasive surgical approach

Osteitis condensans Ilii (OCI) is an orthopaedic mystery until now and the refractory type poses a great challenge in its management. Surgical resection and sacroiliac arthrodesis are major procedures with no guarantee of success for an unknown disease entity with a normal sacroiliac joint. The aim of this retrospective study was to evaluate results of a novel mini-invasive surgical approach for the refractory type after failure of conservative management. Fourteen females were included with an average age 35.5 ± 5.8 years. Nine cases were multiparous and five were nulliparous. The pathology was bilateral in all cases; however, seven cases suffered bilateral symptoms, while seven cases had only unilateral complaints. Preoperative computed tomography was mandatory. All cases had three to five percutaneous iliac core decompressions through a cannulated drill bit. The Bath ankylosing spondylitis functional index (BASFI) was used for functional outcome evaluation. The mean follow up was 23.3 ± 4.1 months. The mean BASFI improved from 3.7 ± 0.6 preoperatively to 1.3 ± 0.2 during follow up (P = <0.001). There was a significant improvement with the four drillings over five decompression drillings (P = 0.011). Sacral side sclerosis was associated significantly (P = 0.009) with less improvement. No relapse or substantial complications were encountered. This novel approach can be of great benefit for refractory OCI cases with almost no added morbidity or complications. It has advantages of the mini-invasive techniques in addition to sparing the physiological functions of the affected sacroiliac joints.

Radiation- and reference base-free navigation procedure for placement of instruments and implants: Application to retrograde drilling of osteochondral lesions of the knee joint

Objective: A novel, radiation- and reference base-free procedure for placement of navigated instruments and implants was developed and its practicability and precision in retrograde drillings evaluated in an experimental setting.Materials and Methods: Two different guidance techniques were used: One experimental group was operated on using the radiation- and reference base-free navigation technique (Fluoro Free), and the control group was operated on using standard fluoroscopy for guidance. For each group, 12 core decompressions were simulated by retrograde drillings in different artificial femurs following arthroscopic determination of the osteochondral lesions. The final guide-wire position was evaluated by postoperative CT analysis using vector calculation.Results: High precision was achieved in both groups, but operating time was significantly reduced in the navigated group as compared to the control group. This was due to a 100% first-pass accuracy of drilling in the navigated group; in the control group a mean of 2.5 correction maneuvers per drilling were necessary. Additionally, the procedure was free of radiation in the navigated group, whereas 17.2 seconds of radiation exposure time were measured in the fluoroscopy-guided group.Conclusion: The developed Fluoro Free procedure is a promising and simplified approach to navigating different instruments as well as implants in relation to visually or tactilely placed pointers or objects without the need for radiation exposure or invasive fixation of a dynamic reference base in the bone.

No Influence on the Incidence of Osteonecroses When Dexamethasone Replaces Prednisone during Induction Treatment for Childhood ALL: Results of Trial ALL-BFM 2000.

Osteonecroses (ON) are common complications associated with the treatment of acute lymphoblastic leukemia (ALL). For symptomatic ON, incidences of 1.6% to 9.3% have been published in the literature. The range of incidence rates may be related to treatment, data acquisition methods and patients' age distribution. Between 09/99 and 06/06, 3,048 protocol patients with ALL (age 1–17 years) were enrolled into the multicenter trial ALL-BFM 2000 (Germany, Austria, Switzerland). Data on symptomatic ON were prospectively collected and were reported in 111 patients (3.6%, 95% confidence interval (CI) 3.0–4.4%). The median age of the patients with ON was 12.8 years (range 1.3–17.9 years), the median time from ALL diagnosis until diagnosis of ON was 15 months (range 2–73 months; data available from 92 patients). The incidence in adolescents, in particular adolescent girls, was significantly higher than in younger children (age <10 years: girls 0.8%, boys 0.7%, p=0.68; ≥ 10 years: girls 18.4%, boys 7.6%, p<0.001). The corticosteroid preparation used in the induction therapy (randomization 60 mg/m2/day prednisone vs. 10 mg/m2/day dexamethasone for three weeks plus tapering) did not influence the ON rate (prednisone 3.2%, dexamethasone 3.0%, p=0.77, 95% CI for difference: −1.2 – 1.6%). Various treatment attempts of ON were reported; 10 patients have been documented to be free of symptoms. At least 38 patients underwent surgical interventions, mainly core decompressions. Total endoprostheses of one or both hips were implanted in at least 10 patients. Final evaluation of all patients in particular with regard to long-term sequelae is not yet possible. The existing data demonstrate the far-reaching consequences of ON for the quality of life in a considerable proportion of the patients. Comparing these results with the ON data of study ALL-BFM 95 (Bürger et al., Pediatr Blood Cancer, 2005) which were collected in a predominantly retrospective way, the data suggest an increase in ON incidence in the current trial ALL-BFM 2000 (ALL-BFM 95: 1.6%). As the control treatment arms of the two trials were quite similar and the randomized treatment modifications in ALL-BFM 2000 had no influence on the ON rate, the higher incidence may be attributed to the prospective data collection in the current study and possibly to a higher attention to these complications by the attending doctors.

Do Modern Techniques Improve Core Decompression Outcomes for Hip Osteonecrosis?

Core decompression procedures have been used in osteonecrosis of the femoral head to attempt to delay the joint destruction that may necessitate hip arthroplasty. The efficacy of core decompressions has been variable with many variations of technique described. To determine whether the efficacy of this procedure has improved during the last 15 years using modern techniques, we compared recently reported radiographic and clinical success rates to results of surgeries performed before 1992. Additionally, we evaluated the outcomes of our cohort of 52 patients (79 hips) who were treated with multiple small-diameter drillings. There was a decrease in the proportion of patients undergoing additional surgeries and an increase in radiographic success when comparing pre-1992 results to patients treated in the last 15 years. However, there were fewer Stage III hips in the more recent reports, suggesting that patient selection was an important reason for this improvement. The results of the small-diameter drilling cohort were similar to other recent reports. Patients who had small lesions and were Ficat Stage I had the best results with 79% showing no radiographic progression. Our study confirms core decompression is a safe and effective procedure for treating early stage femoral head osteonecrosis.

Surgical and Molecular Advances in Osteonecrosis: Editorial Comment

Surgical and Molecular Advances in Osteonecrosis: Editorial Comment

Comparison of results of core decompression and intertrochanteric osteotomy for nontraumatic osteonecrosis of the femoral head using Cox regression and survivorship analysis

Different surgical procedures have been recommended for osteonecrosis of the femoral head to prevent or delay the need for arthroplasty. Core decompression is a commonly used treatment in the early stages of the disease, but the published efficacy has varied markedly. Only a few comparisons of different techniques have been reported. The aim of this study was to evaluate and compare the results of 2 commonly used procedures, core decompression and intertrochanteric osteotomy, using Cox regression and survivorship analysis. A total of 177 cases with a mean age of 41 years at surgery were treated for osteonecrosis (94 core decompressions, 83 osteotomies). Any further surgery was defined as failure and endpoint. Significant risk factors for treatment failure were age >40 years at surgery (P=.022), corticosteroid intake (P<.001), advanced stage of necrosis (Steinberg stage ≥III, P=.04), and core decompression (P=.084). To analyze the influence of the surgical procedure, patients with corticosteroid treatment were excluded, and survival analysis was performed. This analysis revealed survival rates of 74% after osteotomy and 78% after core decompression 6 years postoperatively in early, precollapse stages (P=.819). In advanced stages, the rate of survival for hips after core decompression was lower (56%) than in hips after osteotomy (76%) (P=.056). Our results indicate that core decompression may be as effective as intertrochanteric osteotomy in precollapse stages but is less traumatizing and is cost-effective. For postcollapse hips, intertrochanteric osteotomy should be considered.

Atraumatic osteonecrosis of the adult elbow.

Osteonecrosis is a disease that leads to joint destruction and often involves large joints, such as the hips, knees, and shoulders. Nontraumatic osteonecrosis of the adult elbow, to the best of the authors' knowledge, has not been reported. Nine adult patients with atraumatic osteonecrosis of 11 elbows were identified. The mean age at presentation was 36 years (range, 26-63 years); five patients were women and four were men. Six elbows involved the capitellum, three involved the lateral epicondyles, one involved the trochlea and radial head, and one involved medial and lateral epicondylar disease. All patients were receiving corticosteroid therapy, and no relationship between the duration or the amount of corticosteroid use and the severity of the osteonecrosis was found. Seven patients with radiographic Stage I and Stage II disease responded well to nonoperative treatments consisting of activity modification, analgesics, and a brief period of immobilization. Nonoperative treatment failed in two patients with Stage III disease, and they had core decompressions for pain relief. One patient with late Stage III disease in both elbows underwent bilateral total elbow arthroplasties. In contrast to the pediatric population, osteonecrosis of the adult elbow potentially can lead to end stage arthritis. If the osteonecrosis is diagnosed early, nonoperative treatment may be effective in relieving pain, although the long-term results of these treatments remain unknown.

Femoral head osteonecrosis after bone marrow transplantation.

Thirty-five patients with bilateral osteonecrosis of the femoral head after bone marrow transplantation were reviewed retrospectively. The median age at the time of transplantation was 26 years. The first symptoms occurred within 2 years of transplantation. At presentation, 18 of the patients reported pain in both hips, 17 had symmetric radiographic lesions, and 39 of the hips had collapsed. Medical treatment was indicated initially. At the final examination before surgery (median, 3.5 years), 31 patients had bilateral hip pain, 22 patients had symmetric radiographic lesions, and 56 of the hips had collapsed. Fifty-seven of the hips required surgery, including one open drainage, four core decompressions, six cup arthroplasties, and 46 primary total hip replacements. Six hips (four core decompressions; two cups) later underwent total hip replacement revision, and a deep infection developed in one. By considering the requirement of a total hip replacement as a failure of conservative treatment, the rate of survival of the femoral head was 30% 5 years after the transplant. There was no significant difference between the Ficat grades, except for Grade 0, which showed a higher survival rate. The study of the specific features of the osteonecrosis may lead to the recommendation of primary total hip arthroplasty after failure of the medical treatment.

Femoral Head Necrosis After Kidney Transplantation

From January 1, 1993 through July 31, 1997, 184 kidney transplantations were performed at our center. Of these patients, 173 entered regular follow-up at the transplantation clinic. Five patients (2.8%) developed hip pain during this interval and were referred to the orthopedic clinic. Of these five patients, four were men and one was a woman. Their average age was 38.2 years (range 27 to 45 years). All had been undergoing hemodialysis for an average of 13.2 months (range 3 to 25 months) before their kidney transplantations. After transplantation, they received a triple-drug immunosuppressive regimen of deltacortisone, azathioprine, and cyclosporine (CyA). The patients developed symptoms of femoral head avascular necrosis at an average of 11.4 months (range 7 to 18 months) posttransplantation. Among the five patients, six hip joints were symptomatic and painful. Using both plain radiography and magnetic resonance imaging (MRI) studies, all 10 hip joints were diagnosed with ARCO (Association Research Circulation Osseous) stage 1 avascular necrosis of the femoral head. The patient with bilaterally painful hip joints was managed conservatively with rest and range of motion and muscle-strengthening exercises. Three patients were managed with surgical treatment of the symptomatic hip by core decompression and conservative treatment of the asymptomatic hip. One patient with one symptomatic hip underwent bilateral core decompressions.

Bone-marrow oedema syndrome and transient osteoporosis of the hip. An MRI-controlled study of treatment by core decompression.

Bone-marrow oedema syndrome (BMOS) of the hip gives a characteristic MRI pattern, in association with severe pain, non-specific focal loss of radiological density and a positive bone scan. In our MRI-controlled study, nine patients with non-traumatic BMOS in ten hips all had core decompression. Bone-marrow pressure measurements and intraosseous venography in five cases showed pathological values. All patients had immediate relief of pain, with return of MRI signals to normal after three months. Regular review was continued for at least 24 months with serial clinical radiological and MRI assessment. At a mean follow-up of 33 months all patients remained free of pain with normal radiographs and MR scans. The histological evaluation of undecalcified sections obtained from eight core decompressions confirmed the presence of bone-marrow oedema, with necrotic and reparative processes involving bone and marrow similar to those of early avascular necrosis but with no evidence of 'osteoporosis'. These findings support the assumption that BMOS may be the initial phase of non-traumatic avascular necrosis. In most patients BMOS will have a self-limiting course, but the duration of symptoms may be reduced by core decompression treatment.

Core decompression in femoral head osteonecrosis: 18 Stage I hips followed up for 1–5 years

In a prospective study, we performed 18 core decompressions for Stage I primary osteonecrosis of the femoral head. Only 5 patients (six hips) seemed to have benefited from the intervention for more than 1 year.

Core decompression for early atraumatic osteonecrosis of the femoral head

We performed 41 core decompressions in 32 patients for stage I or stage II osteonecrosis of the femoral head. The intra-osseous pressure at the intertrochanteric level was raised in 28 (68%) and there was histological confirmation of necrosis in 36 hips (88%). After a follow-up of 10 to 84 months (mean 31) nine of the 12 stage I hips (75%) showed significant clinical or radiological deterioration; no evidence of necrosis had been found in the core specimens of the other three hips. Of the 29 hips in stage II, 25 (86%) showed significant radiological deterioration, and only five (17%) had improved clinically. We believe that once necrosis has occurred, core decompression will not significantly influence the subsequent course of the disease.