The characteristics and predictors of mortality in periprosthetic fractures around the knee.

Aims: Periprosthetic fractures (PPFs) around the knee are challenging injuries. This study aims to describe the characteristics of knee PPFs and the impact of patient demographics, fracture types, and management modalities on in-hospital mortality. Methods: Using a multicentre study design, independent of registry data, we included adult patients sustaining a PPF around a knee arthroplasty between 1 January 2010 and 31 December 2019. Univariate, then multivariable, logistic regression analyses were performed to study the impact of patient, fracture, and treatment on mortality. Results: Out of a total of 1,667 patients in the PPF study database, 420 patients were included. The in-hospital mortality rate was 6.4%. Multivariable analyses suggested that American Society of Anesthesiologists (ASA) grade, history of peripheral vascular disease (PVD), history of rheumatic disease, fracture around a loose implant, and cerebrovascular accident (CVA) during hospital stay were each independently associated with mortality. Each point increase in ASA grade independently correlated with a four-fold greater mortality risk (odds ratio (OR) 4.1 (95% confidence interval (CI) 1.19 to 14.06); p = 0.026). Patients with PVD have a nine-fold increase in mortality risk (OR 9.1 (95% CI 1.25 to 66.47); p = 0.030) and patients with rheumatic disease have a 6.8-fold increase in mortality risk (OR 6.8 (95% CI 1.32 to 34.68); p = 0.022). Patients with a fracture around a loose implant (Unified Classification System (UCS) B2) have a 20-fold increase in mortality, compared to UCS A1 (OR 20.9 (95% CI 1.61 to 271.38); p = 0.020). Mode of management was not a significant predictor of mortality. Patients managed with revision arthroplasty had a significantly longer length of stay (median 16 days; p = 0.029) and higher rates of return to theatre, compared to patients treated nonoperatively or with fixation. Conclusion: The mortality rate in PPFs around the knee is similar to that for native distal femur and neck of femur fragility fractures. Patients with certain modifiable risk factors should be optimized. A national PPF database and standardized management guidelines are currently required to understand these complex injuries and to improve patient outcomes.

Predictors of mortality in periprosthetic fractures of the hip: Results from the national PPF study.

INTRODUCTION: Periprosthetic fractures (PPFs) around the hip joint are increasing in prevalence. In this collaborative study, we aimed to investigate the impact of patient demographics, fracture characteristics, and modes of management on in-hospital mortality of PPFs involving the hip. METHODS: Using a multi-centre cohort study design, we retrospectively identified adults presenting with a PPF around the hip over a 10-year period. Univariate and multivariable logistic regression analyses were performed to study the independent correlation between patient, fracture, and treatment factors on mortality. RESULTS: A total of 1,109 patients were included. The in-hospital mortality rate was 5.3%. Multivariable analyses suggested that age, male sex, abbreviated mental test score (AMTS), pneumonia, renal failure, history of peripheral vascular disease (PVD) and deep surgical site infection were each independently associated with mortality. Each yearly increase in age independently correlates with a 7% increase in mortality (OR 1.07, p=0.019). The odds of mortality was 2.99 times higher for patients diagnosed with pneumonia during their hospital stay [OR 2.99 (95% CI 1.07-8.37) p=0.037], and 7.25 times higher for patients that developed renal failure during their stay [OR 7.25 (95% CI 1.85-28.47) p=0.005]. Patients with history of PVD have a six-fold greater mortality risk (OR 6.06, p=0.003). Mode of treatment was not a significant predictor of mortality. CONCLUSION: The in-hospital mortality rate of PPFs around the hip exceeds 5%. The fracture subtype and mode of management are not independent predictors of mortality, while patient factors such as age, AMTS, history of PVD, pneumonia, and renal failure can independently predict mortality. Peri-operative optimisation of modifiable risk factors such as lung and kidney function in patients with PPFs around the hip during their hospital stay is of utmost importance.

Comparing pinning in situ and capital realignment procedures for severe, stable slipped capital femoral epiphysis: a systematic review.

In severe, stable slipped capital femoral epiphysis, it is unclear whether pinning in situ (PIS) or capital realignment procedures (CRPs) are superior. Our primary aim was to compare patient-reported outcome measures (PROMs) following each strategy. Secondary aims were to compare rates of femoral head avascular necrosis (AVN) and complications. MEDLINE, Embase and Cochrane databases were searched according to an agreed strategy. Narrative review articles, case reports, letters to the editor and articles not written in English were excluded. The risk of bias was assessed using the Newcastle-Ottawa Scale. Of the 132 citations identified, 127 were excluded following de-duplication and application of the exclusion criteria. Three observational studies comparing PIS with CRP and two case series considering CRP alone were identified. One article was considered fair quality, and four articles were considered poor. In total, 198 hips from five studies were included (66 PIS, 132 CRP). PIS was associated with moderate-good functional outcomes, and CRP with good-high outcomes. Two comparative studies reported significantly better PROMs following CRP. AVN was reported in 1.5% following PIS and 10.6% following CRP. Regarding other complications, chondrolysis occurred in 3.0% following PIS and 2.4% following CRP. Femoroacetabular impingement rates were markedly higher following PIS (60.6% versus 2.3%). Reoperation rates were also greater following PIS (34.5% versus 13.3%). PIS tends to be associated with favourable AVN rates, but CRP with favourable PROMs and complication rates. However, comparisons were drawn from heterogeneous studies lacking long-term follow-up. Further high-quality research is required.

Mid- to long-term results of the Cone-Conical modular system in revision hip arthroplasty.

BACKGROUND: Modular design in revision hip surgery allows some flexibility intra-operatively to address leg length discrepancy, version, and offset while allowing the surgeon to bypass a deficient proximal femur and achieve axial and rotational stability distally. The purpose of this study was to analyze the mid-term to long-term survival and clinical and radiological outcomes using a conical fluted stem and a cone-shaped hydroxyapatite-coated proximal body "The Cone-Conical modular system (Stryker)" in revision hip surgery. METHODS: We retrospectively reviewed all the patients who underwent hip revision surgery using Cone-Conical modular system between January 2006 and January 2015 at our institution. Seventy patients (72 hips) were included with a mean age of 71.3 years. We had a mean follow-up period of 8.6 years (range 5-15). All patients had a minimum follow-up of five years. A Kaplan-Meier analysis was used to determine the survival of the implant. Functional outcomes were assessed using Oxford Hip Score. Plain radiographs were performed to assess implant fixation and osseointegration. RESULTS: The mean OHS improved significantly from 12 pre-operatively to 34 at the final follow-up (P < .001). The Cone-Conical system survivorship for aseptic loosening as an end point was 100%. The all-cause survivorship was 97.2%. Two hips had revisions for recurrence of infection. CONCLUSIONS: The Cone-Conical femoral modular revision system has demonstrated excellent mid-term to long-term clinical and radiographic results with low failure rate and minimal complications. Longer-term follow-up would be of value to assess the ongoing survival of this implant.

The outcome of the uncemented acetabular component in delayed total hip arthroplasty following acetabular fractures.

AIMS: After failed acetabular fractures, total hip arthroplasty (THA) is a challenging procedure and considered the gold standard treatment. The complexity of the procedure depends on the fracture pattern and the initial fracture management. This study's primary aim was to evaluate patient-reported outcome measures (PROMs) for patients who underwent delayed uncemented acetabular THA after acetabular fractures. The secondary aims were to assess the radiological outcome and the incidence of the associated complications in those patients. METHODS: A total of 40 patients underwent cementless acetabular THA following failed treatment of acetabular fractures. The postoperative clinical and radiological outcomes were evaluated for all the cohort. RESULTS: The median (interquartile range (IQR)) Oxford Hip Score (OHS) improved significantly from 9.5 (7 to 11.5), (95% confidence interval (CI) (8 to 10.6)) to 40 (39 to 44), (95% CI (40 to 43)) postoperatively at the latest follow-up (p < 0.001). It was worth noting that the initial acetabular fracture type (simple vs complex), previous acetabular treatment (ORIF vs conservative), fracture union, and restoration of anatomical centre of rotation (COR) did not affect the final OHS. The reconstructed centre of rotation (COR) was restored in 29 (72.5%) patients. The mean abduction angle in whom acetabular fractures were managed conservatively was statistically significantly higher than the surgically treated patients 42.6° (SD 7.4) vs 38° (SD 5.6)) (p = 0.032). We did not have any case of acetabular or femoral loosening at the time of the last follow-up. We had two patients with successful two-stage revision for infection with overall eight-year survival rate was 95.2% (95% CI 86.6% to 100%) with revision for any reason at a median (IQR) duration of follow-up 50 months (16 to 87) months following THA. CONCLUSION: Delayed cementless acetabular THA in patients with previous failed acetabular fracture treatments produces good clinical outcomes (PROMS) with excellent survivorship, despite the technically demanding nature of the procedure. The initial fracture treatment does not influence the outcome of delayed THA. In selected cases of acetabular fractures (either nondisplaced or with secondary congruency), the initial nonoperative treatment neither resulted in large acetabular defects nor required additional acetabular reconstruction at the time of THA. Cite this article: Bone Jt Open 2021;2(12):1067-1074.

Functional outcome and health-related quality of life following ipsilateral femoral and acetabular fractures: a retrospective analysis.

INTRODUCTION: The combination of ipsilateral femoral and acetabular fractures is known in the literature as the "Floating hip injury". The primary aim of this study is to assess both generic and specific patient-reported outcomes and the factors affecting the quality of life in patients sustaining this injury, while the secondary aim was to assess the injury patterns and the associated complications. METHODS: A retrospective study including 27 patients according to specific inclusion and exclusion criteria. EQ5D5L and Oxford hip score (OHS) were used. The mean age was 28 years (±10.1 SD) and 21 patients (77.8%) were males. The mean follow-up was 7 years (± 3.1 years SD). RESULTS: Median OHS was 46.5 (IQR: 31.5-48). The median EQ5D score was 0.919 (95% CI: 0.601-1). The mean EQ5D index value was 0.679 ± 0.442 (95% CI: 0.492-0.865). In this young cohort of patients, this drop in the mean EQ5D index value has led to a loss of a mean of 2.2 Quality-adjusted Life Years (QALYs). Through multivariate analysis, we found that the quality of life was mainly affected by the occurrence of end-stage arthritis, the presence of non-recovered traumatic sciatic nerve injury, and the occurrence of infection. CONCLUSIONS: Our findings show that the quality of life of those patients was significantly affected. These findings can be beneficial in counselling patients sustaining this complex injury and could be helpful in the discussion of the prognosis and in planning postoperative rehabilitation and support.

Management of mucoid degeneration of the anterior cruciate ligament: a systematic review.

PURPOSE: The purpose of this study was to investigate the outcomes of management of mucoid degeneration of the anterior cruciate ligament (MDACL) by performing a systematic review of methods of treatment that have been reported. METHODS: A systematic literature search in the databases MEDLINE, Embase, Google Scholar, Cochrane, ISI web of science and Scopus was performed through July 2020 by three independent reviewers. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and registered in the PROSPERO database (CRD42018087782). Quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) criteria. RESULTS: A total of nine studies were eligible for review. All nine studies assessed the outcome of arthroscopic debridement of MDACL. A total of 313 knees in 292 patients were included. The mean follow up ranged from 13 to 72 months. There was strong association between MDACL and chondral lesions (82%) and between MDACL and meniscal tears (69%). The rate of simultaneous meniscectomy ranged from 13 to 44%. Postoperative pain relief ranged from 53.8 to 95%. There was an improvement in postoperative range of motion and outcome scores (Lysholm and International Knee Documentation Committee scores and the Knee Injury and Osteoarthritis Outcome Score). Postoperative Lachman test was positive in 40% of patients, and 6% of patients had symptomatic instability. The mean MINORS score was 9.5 out of 16 (4-12). CONCLUSIONS: Arthroscopic debridement of the anterior cruciate ligament (ACL) results in satisfactory pain relief and improvement in knee outcome scores. Postoperative ACL laxity is common after arthroscopic ACL debridement, however, symptomatic instability is not. The need for delayed ACL reconstruction should be discussed preoperatively, especially if complete resection of the ACL is to be performed. LEVEL OF EVIDENCE: IV.

Effectiveness, Patient Satisfaction, and Cost Reduction of Virtual Joint Replacement Clinic Follow-Up of Hip and Knee Arthroplasty.

BACKGROUND: Total hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients' satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic. METHODS: A total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up. RESULTS: The VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients' satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up. CONCLUSION: VJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients.

Acetabular liner dissociation: A case report and review of the literature.

Dissociation of the polyethylene liner from the acetabular shell is a rare but catastrophic complication of total hip arthroplasty (THA). There have been reports of polyethylene liner dissociation (PLD) as well as ceramic liner dissociation (CLD) in the literature. Amongst the commonly used implants, liner dissociation has been reported with the Pinnacle (DePuy), Harris-Galante (Zimmer) and Trident (Stryker) acetabular components. To the best of our knowledge, this is the first case report of PLD in an R3 (Smith & Nephew) acetabular component. This case report highlights the implant choice for treatment of the liner dissociation and the role of constrained implants in such cases.

Association between Allogeneic Blood Transfusion and Wound Infection after Total Hip or Knee Arthroplasty: A Retrospective Case-Control Study.

Background: To assess using a retrospective case control study, whether patients undergoing primary, elective total hip or knee arthroplasty who receive blood transfusion have a higher rate of post-operative infection compared to those who do not. Materials and Methods: Data on elective primary total hip or knee arthroplasty patients, including patient characteristics, co-morbidities, type and duration of surgery, blood transfusion, deep and superficial infection was extracted from the Alberta Bone and Joint Health Institute (ABJHI). Logistic regression analysis was used to compare deep infection and superficial infection in blood-transfused and non-transfused cohorts. Results: Of the 27892 patients identified, 3098 (11.1%) received blood transfusion (TKA 9.7%; THA 13.1%). Overall, the rate of superficial infection (SI) was 0.5% and deep infection (DI) was 1.1%. The infection rates in the transfused cohort were SI 1.0% and DI 1.6%, and in the non-transfused cohort were SI 0.5% and DI 1.0%. The transfused cohort had an increased risk of superficial infection (adjusted odds ratio (OR) 1.9 [95% CI 1.2-2.9, p-value 0.005]) as well as deep infection (adjusted OR 1.6 [95% CI 1.1-2.2, p-value 0.008]). Conclusion: The odds of superficial and deep wound infection are significantly increased in primary, elective total hip and knee arthroplasty patients who receive blood transfusion compared to those who did not. This study can potentially help in reducing periprosthetic hip or knee infections.

Role of arthroscopy for the diagnosis and management of post-traumatic hip pain: a prospective study.

The current published literature regarding the role of hip arthroscopy in the diagnosis and management of post-traumatic hip pain is still limited. Therefore, we conducted the present prospective study to determine the value of hip arthroscopy in the diagnosis and management of various causes of hip pain after traumatic conditions. The present study included a prospective cohort of 17 patients with symptomatic post-traumatic hip pain. It was conducted between July 2013 and May 2018. The mean age was 22 (19-29) years and the mean follow-up was 24 (r: 7-36) months. Prior to surgery, every eligible patient underwent assessment of functional status using the Modified Harris Hip Score, Oxford hip score (OHS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) score. All patients underwent arthroscopic management for their diagnosed pathologies. The most commonly encountered diagnosis was labral tear (58.8%), followed by ligamentum teres tear (35.3%) and loose intra-articular fragments (29.4%). In addition, 52.9% of the patients had associated CAM lesion and 11.8% had associated Pincer lesion. The mHSS, OHS and WOMAC score showed significant improvement in the post-operative period (P < 0.001), all the 17 patients had 100% Patient Acceptable Symptomatic State; only one patient did not achieve minimal clinical importance difference. One case underwent labral debridement for failed labral repair (5.8%), another patient developed maralgia paraesthetica (5.8%). In conclusion, hip arthroscopy is a useful and effective minimally invasive procedure for the diagnosis and management of selected patients with post-traumatic hip pain. Moreover, hip arthroscopy was safe technique with no reported serious adverse events.

Tritanium Acetabular Cup in Revision Hip Replacement: A Six to Ten Years of Follow-Up Study.

BACKGROUND: The use of highly porous acetabular components has shown to produce good results in revision acetabular surgery. Their surface characteristics enhance initial fixation and bone ingrowth which are prerequisites for adequate osseointegration. The purpose of this study is to analyze the mid-term to long-term survival, clinical and radiological outcomes using the Tritanium cup (Stryker, Mahwah, NJ) in revision hip surgery. METHODS: This is a retrospective review of all patients who underwent acetabular revision surgery using "Tritanium revision cup" between April 2007 and November 2010 at our institution. Sixty-two patients were included with a mean age of 67.5 years (32-86). According to Paprosky classification, 10 patients had type I defect, 8 had type IIA, 27 had type IIB, 7 had type IIC, and 10 suffered from type IIIA defect. A Kaplan-Meier analysis was used to determine the survival of the cup. Functional outcomes were assessed using Oxford Hip Score. Plain radiographs were performed to assess implant fixation and osseointegration. RESULTS: The acetabular cup aseptic survivorship was 98.4% at a mean follow-up of 87.6 months. The mean Oxford Hip Score improved from 14.5 (3-31) preoperatively to 38.5 (12-48) at the final follow-up. Two cups were revised (3.2%): 1 for aseptic loosening and 1 for infection. CONCLUSION: Tritanium revision acetabular cup has shown excellent mid-term to long-term clinical and radiographic results with low failure rate and minimal complications. Longer term follow-up would be of value to assess the ongoing survival of this implant construct.

Mid-Term Results of Graft Augmentation Prosthesis II Cage and Impacted Allograft Bone in Revision Hip Arthroplasty.

BACKGROUND: Several techniques have been described for management of severe acetabular bone defects during revision hip surgery including reconstructive cages. The purpose of this study is to analyze the survival and the mid-term clinical and radiological outcome using the Graft Augmentation Prosthesis (GAP II cage) (Stryker Orthopaedics, Mahwah, NJ) in addition to impaction grafting for acetabular defects in revision hip surgery. METHODS: This is a retrospective review of all patients who underwent acetabular revision hip replacement using GAP II cage and impaction bone grafting between 2009 and 2013 at our institution. Twenty-six patients were included with a mean age of 71 years (49-91). According to Paprosky classification, 2 patients had type IIB defect, 4 had type IIC, and 12 had type IIIA, while 8 suffered from type IIIB defect. The clinical outcome was assessed using Oxford Hip Score. Plain radiographs were used to assess preoperative bone loss, postoperative implant migration, and the incorporation of the bone graft to host bone. RESULTS: The average Oxford Hip Score improved from 11.3 (2-22) preoperatively to 32.2 (20-48) postoperatively. The revision free survivorship of this construct was 100% at mean follow-up of 49 months (30-78). Three hips had radiological failure of the implant with no clinical consequences. CONCLUSION: The use of GAP II cage with impaction bone grafting to reconstruct severe acetabular defects had encouraging mid-term results with low failure rate. Graft incorporation with restoration of bone stock may be beneficial should further revision surgery be needed.

A Traffic Light Grading System of Hip Dysplasia to Predict the Success of Arthroscopic Hip Surgery.

BACKGROUND: The role of hip arthroscopic surgery in dysplasia is controversial. PURPOSE: To determine the 7-year joint preservation rate after hip arthroscopic surgery in hip dysplasia and identify anatomic and intraoperative features that predict the success of hip preservation with arthroscopic surgery, allowing the formulation of an evidence-based classification system. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: Between 2008 and 2013, 111 hips with dysplastic features (acetabular index [AI] >10° and/or lateral center-edge angle [LCEA] <25°) that underwent arthroscopic surgery were identified. Clinical, radiological, and operative findings and the type of procedure performed were reviewed. Radiographic evaluations of the operated hip (AI, LCEA, extrusion index) were performed. Outcome measures included whether the hip was preserved (ie, did not require arthroplasty) at follow-up and the preoperative and postoperative Non-Arthritic Hip Score (NAHS) and Hip disability and Osteoarthritis Outcome Score (HOOS). The AI and LCEA were calculated, factored by a measure of articular wear (AIf and LCEAf, respectively), according to the University College Hospital, London (UCL) grading system as follows: AIf = AI × (number of UCL wear zones + 1), and LCEAf = LCEA / (number of UCL wear zones + 1). A contour plot of the resulting probability value of failure for every combination of AIf and LCEAf allowed for the determination of the zones with the lowest and highest incidences of failure to preserve the hip. RESULTS: The mean AI and LCEA were 9.8° and 18.0°, respectively. At a mean follow-up of 4.5 years (range, 0.4-8.3 years), 33 hips had failed, requiring hip arthroplasty. The 7-year joint survival rate was 68%. The mean improvements in the NAHS and HOOS were 11 ( P = .001) and 22.8 ( P < .001) points, respectively. The zone with the greatest chance of joint preservation (odds ratio, 10; P < .001) was the green zone, with an AIf of 0° to 15° and an LCEAf of 15° to 25°; in contrast, the zone with the greatest chance of failure (odds ratio, 10; P < .001) was the red zone, with an AIf of 20° to 100° and an LCEAf of 0° to 10°. CONCLUSION: Overall, the 7-year hip survival rate in hip dysplasia appears inferior compared with that reported in femoroacetabular impingement (78%). Hip arthroscopic surgery is associated with an excellent chance of hip preservation in mild dysplasia (green zone: AI = 0°-15°, LCEA = 15°-25°) and no articular wear. The authors advise that the greatest caution should be used when considering arthroscopic options in cases of severe dysplasia (red zone: AI >20° and/or LCEA <10°).

Management of Vancouver B2 and B3 Periprosthetic Proximal Femoral Fractures by Distal Locking Femoral Stem (Cannulok) in Patients 75 Years and Older.

BACKGROUND: Periprosthetic fracture following total hip arthroplasty is a significant problem faced by hip surgeons, and its management in elderly patients remains a considerable challenge. METHODS: We retrospectively reviewed 28 Vancouver B2 and B3 periprosthetic femoral fractures (PFF) treated with revision of the femoral stems by distally locked, hydroxyapatite-coated uncemented stems (Cannulok). Patients were aged 75 years or older at the time of surgery. RESULTS: The mean follow-up was 44.6 months (range, 24-102). The mean postoperative Oxford hip score was 30.1 (range, 10-46). The rate of fracture union was 95.8%, and the survivorship of the stem was 100% at the end of follow-up. CONCLUSION: The management of PFF in elderly is associated with increased postoperative morbidity and mortality. The use of a distally locked, hydroxyapatite-coated femoral stem is a valid option for the treatment of PFF to achieve fracture union with a low rate of revision.

Bilateral Osteonecrosis of the Femoral and Humeral Heads after Short Term Corticosteroid Therapy. A Case Study.

Steroid induced osteonecrosis is a devastating injury that usually requires rebuild of the joint, with the femoral and the humeral head being most commonly affected. Steroid therapy is the most common reported cause of atraumatic osteonecrosis. The Collaborative Osteonecrosis Group Study confirmed that steroids are the primary cause of multi-focal osteonecrosis in 91% of the cases. Osteonecrosis is considered multifocal when three or more joints are involved. We report a rare case of bilateral steroid-induced osteonecrosis of the proximal femora and humeri nine months after a short course of intravenous methylprednisolone for treatment of multiple myeloma. The relationship between development of osteonecrosis and corticosteroid treatment has been extensively investigated. Steroid therapy is the most common reported cause of atraumatic osteonecrosis. Multi-focal osteonecrosis should be highly suspected and thoroughly investigated in patients with persistent pain at typical sites after commencement of steroids.