Radiological follow-up of osteonecrosis lesions in children and adolescents with Hodgkin lymphoma.

Osteonecrosis (ON) is a common complication of glucocorticoid-based Hodgkin lymphoma (HL) treatment, but the natural evolution and prognosis of ON lesions remain poorly understood. We describe the radiological evolution of ON lesions identified in a Nordic population-based cohort of paediatric HL patients. Magnetic resonance images of suspected ON lesions were centrally reviewed to confirm ON diagnosis and grade the ON lesions according to the Niinimäki classification. The study included 202 ON lesions in 46 patients, of which 77 were joint lesions. Follow-up images were available for 146/202 lesions, with a mean follow-up time of 28 months. During follow-up, 71% of the lesions remained stable, 26% improved or resolved, and 3% progressed. A higher ON grade at diagnosis was associated with a lower likelihood of spontaneous resolution. The likelihood for resolution of ON decreased by 50% for each year of added patient age, when adjusted for sex, ON location, and symptoms. Hip ON showed less spontaneous improvement compared with other joints, and the risk for surgery was 13-fold in hip ON. Grades 3-4 joint ON has the potential to either progress or resolve, warranting follow-up in patients with severe symptoms. Research on secondary prevention should be directed at grade 3-4 joint ON.

Symptomatic osteonecrosis in children treated for Hodgkin lymphoma: A population-based study in Sweden, Finland, and Denmark.

BACKGROUND: Osteonecrosis (ON) is a potentially disabling skeletal complication of cancer treatment. Although symptomatic osteonecrosis (sON) is well-known in acute lymphoblastic leukemia (ALL), with an incidence around 6%, studies on sON in pediatric Hodgkin lymphoma (HL) are scarce. The aim of this study was to examine the incidence, risk factors, and outcome of sON in children treated for HL. PROCEDURE: A total of 490 children under 18, diagnosed with HL between 2005 and 2019 in Sweden, Finland, and Denmark were eligible for the study. Data on patient characteristics, HL treatment, and development of sON were collected from patients' medical records. Magnetic resonance imaging scans were used to establish ON diagnosis and grade ON according to the Niinimäki grading system. RESULTS: Cumulative 2-year incidence of sON among the 489 included patients was 5.5% (n = 30). The risk for developing sON was higher for those with older age (odds ratio [OR] 1.25, 95% confidence interval [CI]: 1.05-1.49, p < .010), female sex (OR 4.45, CI 1.87-10.58, p < .001), high total cumulative glucocorticoid (GC) doses (OR 1.76, 95% CI: 1.21-2.56, p = 0.003), and advanced HL (OR 2.19, 95% CI: 1.03-4.65, p = .042). Four (13.3%) patients underwent major surgical procedures and 13 (43.3%) had persistent symptoms due to ON at follow-up. CONCLUSIONS: This study shows that sON is as common in pediatric HL as in pediatric ALL, with risk factors such as older age, female sex, high cumulative GC doses, and advanced HL. Future HL protocol development should aim to reduce the burden of ON by modifying GC treatment.

Bisphosphonate treatment in children with acute lymphoblastic leukemia and osteonecrosis - radiological and clinical findings in a national cohort.

Background: Osteonecrosis (ON) is a recognized complication of childhood ALL, but its optimal management remains unestablished. This study evaluated the effect of bisphosphonate (BP) treatment on the evolution of ON lesions in childhood ALL.Material and Methods: We included a national cohort of ALL patients diagnosed with symptomatic ON before 18 years of age and treated with BPs (N = 10; five males). Patients were followed both clinically and with serial MRIs. ON lesions were graded according to the Niinimäki classification.Results: The 10 patients had a total of 55 ON lesions. The median age was 13.3 years at ALL diagnosis and 14.8 years at ON diagnosis. Four patients had received HSCT before the ON diagnosis. BPs used were pamidronate (N = 7), alendronate (N = 2) and ibandronate (N = 1). The duration of BP treatment varied between 4 months and 4 years. In 4/10 patients, BP treatment was given during the chemotherapy. BPs were well-tolerated, with no severe complications or changes in kidney function. At the end of follow up 13/55 (24%) ON lesions were completely healed both clinically and radiographically; all these lesions were originally graded 3 or less. In contrast, ON lesions originally classified as grade 5 (joint destruction; N = 4) remained at grade 5. All grade 5 hip joint lesions needed surgical treatment. During BP treatment, the pain was relieved in 7/10 patients. At the end of follow-up, none of the patients reported severe or frequent pain.Conclusion: BP treatment was safe and seemed effective in relieving ON-induced pain in childhood ALL. After articular collapse (grade 5) lesions did not improve with BP treatment. Randomized controlled studies are needed to further elucidate the role of BPs in childhood ALL-associated ON.

Functional results of total-knee arthroplasty versus medial unicompartmental arthroplasty: two-year results of a randomised, assessor-blinded multicentre trial.

OBJECTIVE: The primary objective of the trial was to assess the clinical effectiveness of medial unicompartmental knee arthroplasty versus total knee arthroplasty in patients with isolated medial osteoarthritis of the knee. DESIGN: Prospective, randomised, 2 years, assessor-blind, multicentre, superiority trial. SETTING: The patients were enrolled between December 2015 and May 2018 from the outpatient clinics of three public high-volume arthroplasty hospitals (Finland). PARTICIPANTS: We recruited 143 patients with symptomatic-isolated medial osteoarthritis of the knee needing an arthroplasty procedure. All the patients were suitable for both unicompartmental and total knee arthroplasties. Population was selected as the end-stage-isolated medial osteoarthritis. INTERVENTIONS: All patients, randomized 1:1, received a medial unicompartmental arthroplasty or a total knee arthroplasty through a similar midline skin incision. Patients were blinded to the type of arthroplasty for the whole 2 years of follow-up. MAIN OUTCOME MEASURES: Primary outcome measure was between-group differences in the Oxford Knee Score (OKS) and secondary outcome Knee injury and Osteoarthritis Score (KOOS) at 2 years postoperatively. The changes within and between the groups were analysed with analysis of variance for repeated measurements. RESULTS: The primary outcome was comparable for medial unicompartmental arthroplasty and total knee arthroplasty at 2 years. The mean difference in the OKS between the groups was 1.6 points (95% CI -0.7 to 3.9). In the KOOS subscales, the mean difference between the groups was 0.1 points (95% CI -4.8 to 5.0) for pain, 7.8 points (95% CI 1.5 to 14.0) for symptoms, 4.3 points (95% CI -0.6 to 9.2) for function in daily living, 4.3 points (95% CI -3.0 to 11.6) for function in sports, and 2.1 points (95% CI -4.8 to 9.1) for knee-related quality of life. CONCLUSIONS: The recovery after unicompartmental knee arthroplasty was faster compared with total knee arthroplasty, but unicompartmental arthroplasty did not provide a better patient-reported outcome at 2 years. TRIAL REGISTRATION NUMBER: NCT02481427.

Comparison of ultrasonographic, radiographic and intra-operative findings in severe hip osteoarthritis.

Aim of this study was to assess the US findings of patients with late-stage hip OA undergoing total hip arthroplasty (THA), and to associate the US findings with conventional radiography (CR) and intraoperative findings. Moreover, the inter-rater reliability of hip US, and association between the US and Oxford Hip Score (OHS) were evaluated. Sixty-eight hips were included, and intraoperative findings were available on 48 hips. Mean patient age was 67.6 years and 38% were males. OA findings-osteophytes at femoral collum and anterosuperior acetabulum, femoral head deformity and effusion-were assessed on US, CR and THA. The diagnostic performance of US and CR was compared by applying the THA findings as the gold standard. Osteoarthritic US findings were very common, but no association between the US findings and OHS was observed. The pooled inter-rater reliability (n = 65) varied from moderate to excellent (k = 0.538-0.815). When THA findings were used as the gold standard, US detected femoral collum osteophytes with 95% sensitivity, 0% specificity, 81% accuracy, and 85% positive predictive value. Concerning acetabular osteophytes, the respective values were 96%, 0%, 88% and 91%. For the femoral head deformity, they were 92%, 36%, 38% and 83%, and for the effusion 49%, 85%, 58% and 90%, respectively. US provides similar detection of osteophytes as does CR. On femoral head deformity, performance of the US is superior to CR. The inter-rater reliability of the US evaluation varies from moderate to excellent, and no association between US and OHS was observed in this patient cohort.

PLS3 Mutations Cause Severe Age and Sex-Related Spinal Pathology.

Objective: Mutations in the X-chromosomal PLS3-gene, encoding Plastin 3, lead to severe early-onset osteoporosis, suggesting a major role for PLS3 in bone metabolism. However, the consequences of abnormal PLS3 function in bone and other tissues remain incompletely characterized. This study evaluated spinal consequences of aberrant PLS3 function in patients with PLS3 mutations. Design: A cross-sectional cohort study with spinal magnetic resonance imaging of 15 PLS3 mutation-positive (age range 9-77 years) and 13 mutation-negative (9-70 years) subjects. Images were reviewed for spinal alignment, vertebral heights and morphology, intervertebral disc changes and possible endplate deterioration. Results: Vertebral changes were significantly more prevalent in the mutation-positive subjects compared with the mutation-negative subjects; they were most abundant in upper thoracic spine, and in all age groups and both sexes, although more prominent in males. Difference in anterior vertebral height reduction was most significant in T5 and T6 (p = 0.046 and p = 0.041, respectively). Mid-vertebral height reduction was most significant in T3 and T5 (p = 0.037 and p = 0.005, respectively), and, for male mutation-positive subjects only, in T4 and T6-10 (p = 0.005-0.030 for each vertebra). Most of the abnormal vertebrae were biconcave in shape but thoracic kyphosis or lumbar lordosis were unchanged. Vertebral endplates were well-preserved in the mutation-positive subjects with even fewer Schmorl nodes than the mutation-negative subjects (10 vs. 16). Conclusions: Compromised PLS3 function introduces severe and progressive changes to spinal structures that are present already in childhood, in both sexes and most abundant in upper thoracic spine. Cartilaginous structures are well-preserved.

Short-term survival of cementless Oxford unicondylar knee arthroplasty based on the Finnish Arthroplasty Register.

BACKGROUND: Cementless unicondylar knee arthroplasty (UKA) was introduced to secure long-term fixation and reduce the risk of revision. Experience with cementless UKA fixation is limited. METHODS: The short-term survival (up to five years) of cementless Oxford UKA was assessed using data from the Finish Arthroplasty Register and was compared with that of cemented Oxford 3 UKA and total knee arthroplasty (TKA). Datawere obtained, from the Finnish Arthroplasty Register, on 1076 cementless Oxford UKAs and 2279 cemented Oxford 3 UKAs performed for primary osteoarthritis in 2005-2015. The Kaplan-Meier method, with revision for any reason as the endpoint, was used to assess the survival of these two UKA groups, and the results were compared with that of 65,563 cemented TKAs treated for primary osteoarthritis over the same period. The risk of revision of both Oxford prostheses was compared using Cox regression model, with adjustment for age and sex, with the cemented TKA group as reference. RESULTS: The three-year survival was 93.7% for the cementless Oxford, 92.2% for the cemented Oxford 3, and 97.3% for the cemented TKA. The corresponding figures at five years were 92.3%, 88.9%, and 96.6%, respectively. The revision rate for both the cementless Oxford and the cemented Oxford 3 was significantly increased when compared with the cemented TKA (P < 0.001). CONCLUSIONS: The survival of the cementless Oxford method was higher than that of the cemented Oxford 3 in the short term. The overall survival of Oxford UKA was poor in comparison with contemporary TKAs.

The radiological and clinical follow-up of osteonecrosis in cancer patients.

BACKGROUND: In patients with cancer, osteonecrosis (ON) lesions can affect multiple sites throughout the skeleton, including the long and short bones and the joints. The aims of this study were to explore the natural course of ON in patients treated for cancer by using radiological classification suitable for multisite ON lesions and to assess correlations between the ON grade and surgical procedures. MATERIAL AND METHODS: Data were retrieved from hospital databases on 233 ON lesions in 54 patients (aged 2-73 years at cancer diagnosis; mean age: 25 years). ONs were graded according to the Niinimäki classification, based on magnetic resonance images. Medical records were reviewed to identify surgical procedures. RESULTS: A total of 14 different ON sites were detected; the hip was the most common site (n = 51), followed by the femur (n = 45), tibia (n = 41) and knee (n = 37). Among the 233 ON lesions, 78.1% did not require surgical procedures. The remaining lesions required total joint arthroplasty (TJA; 40/233, 17.2%), core decompression (3.4%) and arthroscopy (1.3%). Most TJAs (33/40, 82.5%) were performed on the hip. ONs of the knee required TJAs only once; grade 3 knee ONs frequently healed (58%, 11/19). None of the diaphyseal or metaphyseal (grade 1-2) ONs of the long bones required surgery, and no fractures of those bones were identified. CONCLUSIONS: In conclusion, the natural history of ONs varied by the grade and site. Based on our findings, we would not recommend routine radiological follow-ups for grades 1-2 ON lesions that do not affect the joints, because the clinical consequences of those lesions appear to be minimal, although pain relief would be warranted. In contrast, joint deformations (grade 5) require surgery; therefore, intervention studies should focus on grades 3-4 ON lesions.

Discovery Elbow System: clinical and radiological results after 2- to 10-year follow-up.

BACKGROUND: Discovery Elbow System (DES) is a semi-constrained prosthesis, mainly used for patients with rheumatoid arthritis (RA). METHODS: Records from 79 patients with RA (90 DES arthroplasties) were reviewed; 47 patients with 55 DES elbows were re-examined. Range of motion (ROM) of both elbows, upper limb function, and quality of life (Disabilities of the Arm, Shoulder, and Hand [DASH] score, Mayo Elbow Performance Score [MEPS], and the RAND 36-Item Health Survey [RAND-36]) were assessed. Cementing quality was assessed, and radiolucent lines measured from plain radiographs. Mean follow-up was 64 (range 24-123) months. RESULTS: Pre-operatively to post-operatively, mean elbow flexion improved from 120° to 146° (p < 0.001) and mean extension lag improved from 29° to 24° (p = 0.02), respectively. At follow-up, mean supination was 66°, mean pronation was 69°, and mean grip strength was 14 kg. Grip strength and ROM (except supination) were similar between the DES elbow and contralateral un-operated elbow. Mean post-operative MEPS was 93 points (excellent, n = 38; good, n = 14; fair, n = 2; and poor, n = 1). Mean DASH score was 43 points. The RAND-36 showed that physical functioning, physical role functioning, bodily pain, and general health were lower than the Finnish reference values. Primary cementing was challenging, and radiolucent lines appeared during follow-up. Four prostheses were revised because of aseptic loosening (n = 3) and periprosthetic fracture (n = 1). CONCLUSION: DES provides significant improvement in patient's flexion-extension arc. Cementing of the elbow prosthesis was challenging; radiolucent lines appeared during the 5-year follow-up, but their clinical relevance remains unclear. First-generation locking screws may loosen over time. LEVEL OF EVIDENCE: Level IV.

Impaired WNT signaling and the spine-Heterozygous WNT1 mutation causes severe age-related spinal pathology.

BACKGROUND: WNT signaling plays a major role in bone and cartilage metabolism. Impaired WNT/ß-catenin signaling leads to early-onset osteoporosis, but specific features in bone and other tissues remain inadequately characterized. We have identified two large Finnish families with early-onset osteoporosis due to a heterozygous WNT1 mutation c.652T>G, p.C218G. This study evaluated the impact of impaired WNT/ß-catenin signaling on spinal structures. METHODS: Altogether 18 WNT1 mutation-positive (age range 11-76years, median 49years) and 14 mutation-negative subjects (10-77years, median 43years) underwent magnetic resonance imaging (MRI) of the spine. The images were reviewed for spinal alignment, vertebral compression fractures, intervertebral disc changes and possible endplate deterioration. The findings were correlated with clinical data. RESULTS: Vertebral compression fractures were present in 78% (7/9) of those aged over 50years but were not seen in younger mutation-positive subjects. All those with fractures had several severely compressed vertebrae. Altogether spinal compression fractures were present in 39% of those with a WNT1 mutation. Only 14% (2/14) mutation-negative subjects had one mild compressed vertebra each. The mutation-positive subjects had a higher mean spinal deformity index (4.0±7.3 vs 0.0±0.4) and more often increased thoracic kyphosis (Z-score>+2.0 in 33% vs 0%). Further, they had more often Schmorl nodes (61% vs 36%), already in adolescence, and their intervertebral discs were enlarged. CONCLUSION: Compromised WNT signaling introduces severe and progressive changes to the spinal structures. Schmorl nodes are prevalent even at an early age and increased thoracic kyphosis and compression fractures become evident after the age of 50years. Therapies targeting the WNT pathway may be an effective way to prevent spinal pathology not only in those harboring a mutation but also in the general population with similar pathology.

Poor Acetabular Component Orientation Increases Revision Risk in Metal-on-Metal Hip Arthroplasty.

BACKGROUND: The rate of and the reasons for the failure of metal-on-metal (MoM) bearings have recently been discussed in literature. The aim of this study was to evaluate the influence of acetabular cup inclination and version angles on revision risk in patients with MoM hip arthroplasty. METHODS: We retrospectively reviewed 825 patients (976 hips) who underwent a MoM hip arthroplasty between 2000 and 2013. There were 474 men and 351 women, with a mean age of 58 (19-86) years. Acceptable cup orientation was considered to be inside the Lewinnek's safe zone. RESULTS: The mean acetabular inclination angle was 48.9° (standard deviation, 8.1°; range, 16°-76°) and version angle 20.6° (standard deviation, 9.9°; range, -25 to 46°). The cup was found to be outside the Lewinnek's safe zone in 571 hips (58.5%). Acetabular cup revision surgery was performed in 157 hips (16.1%). The cup angles were outside Lewinnek's safe zone in 69.2% of the revised hips. The mean interobserver reliability and intraobserver repeatability of the measurements of cup inclination and version angles were excellent (intraclass correlation coefficients >0.90). The odds ratio for revision in hips outside vs inside the Lewinnek's safe zone was 1.82 (95% confidence interval, 1.26-2.62; P = .0014). CONCLUSION: Our findings provide compelling evidence that a cup position outside the Lewinnek's safe zone is associated with increased revision risk in patients with MoM arthroplasty.

Young patients with hematologic and lymphatic malignancies have an increased risk of hip and knee arthroplasty.

Background Skeletal complications such as osteonecrosis (ON) are potential adverse events in patients treated for cancer, especially in those treated for hematologic and lymphatic malignancies (HLMs). ON may damage the hip or knee joints and may lead to arthrosis requiring total joint arthroplasty (TJA). The aim of this study was to address the risk of TJA in patients with cancer, especially those treated for HLM, in a nationwide population-based setting. Material and methods All patients who had undergone TJA after cancer diagnosis between the years 2000 and 2012 were identified by linking the Arthroplasty Register and the Cancer Registry. Standardized incidence ratios (SIRs) of TJAs were calculated to assess whether patients with any cancer, but especially HLM, have increased risk for TJA when compared with the general population. Results In patients with HLM or other cancer, the overall SIRs were similar compared with the general population. However, in HLM patients under 50 years of age, the SIR was 7.6, and in patients under 35 years of age, it was 45.5. The corresponding SIRs in patients with other cancers were 3.6 and 6.6, respectively. The highest SIRs, including all age groups, were among patients with acute lymphoblastic leukemia (SIR = 4.5) and acute myeloid leukemia (SIR = 1.9). Discussion HLMs imply an increased risk for TJA compared with the general population. The risk is especially high in patients younger than 50 years, regardless of the type of HLM. Young patients with HLM, as well as their healthcare providers, should be aware of the highly increased risk of skeletal complications requiring TJA.

Modular to Monoblock: Difficulties of Detaching the M(2)a-Magnum(TM) Head Are Common in Metal-on-metal Revisions.

BACKGROUND: Modern hip implants typically feature modular heads, which allow for easy exchange and removal from the femoral stem at the time of revision. However, owing to fretting, corrosion, or cold welding, the modular head may be difficult or impossible to separate from the underlying trunnion, especially if the implant has titanium interfaces between the head and the stem. We have repeatedly encountered difficulty removing the titanium sleeve adapter in the M(2)a-Magnum(TM) implant. Although the manufacturer warns about this complication and cases with these difficulties have been reported to the United States FDA, we believed this topic is important to study, because the frequency of difficulties in head removal is unknown and the complications related to this event have not been characterized. QUESTIONS/PURPOSES: We asked: (1) Do revisions of M(2)a-Magnum(TM) implants differ from those of M(2)a-38(TM) implants in terms of ease of removal of the femoral head? (2) In cases where difficulty with M(2)a-Magnum(TM) head removal occurred, was the operative time, bleeding, risk of periprosthetic fracture, or joint infection increased compared with cases where the M(2)a-Magnum(TM) head was removed without difficulties? METHODS: Between 2004 and 2014, we revised 296 THAs with metal-on-metal implants that involved M(2)a-Magnum(TM) (123) or M(2)a-38(TM) heads (88); of those, 84 were planned to include a femoral stem revision and insufficient data were available for three operations, so they were excluded from this analysis, leaving 124 THAs in the current retrospective study (70 THAs with M(2)a-Magnum(TM) and 54 THAs with M(2)a-38(TM) heads).The method of modular head removal, any difficulties removing the femoral head from the trunnion, operation time, and complications were recorded based on chart review. RESULTS: All the observed problems of detaching the head or taper adapter were among M(2)a-Magnum(TM) heads; there were no problems detaching the head in revisions of the M(2)a-38(TM) implant. In 29% (20 of 70) of revisions of the M(2)a-Magnum(TM) implant, the modular head could not be detached by knocking it with a punch and a mallet. Seventeen percent (12 of 70) of hips needed an unplanned stem revision owing to difficulties with head removal. In revisions of the M(2)a-Magnum(TM) implant that experienced head-removal problems, the median operative time was longer (144 minutes; range, 75-274 minutes) and bleeding was greater (725 mL; range, 300-2200 mL) compared with revisions of the M(2)a-Magnum(TM) implant without head removal problems (77 minutes, range, 33-197 minutes, p < 0.001; 475 mL, range, 50-1500 mL, p = 0.004). With the numbers available, we did not see differences in terms of the proportion of patients experiencing major complications (periprosthetic fracture or postoperative infections) between the groups (difficult versus easy; 25% [five of 20] versus 8% [four of 50]; odds ratio, 3.8 [95% CI, 0.9-16.2], p = 0.067). CONCLUSIONS: The titanium-titanium taper junction can be very difficult to separate during revision THAs, and if not anticipated, this problem can result in larger and more complicated revision procedures in patients who have the M(2)a-Magnum(TM) implant. Although the global use of metal-on-metal implants in THAs has decreased dramatically during the last several years, many thousands remain in service and therefore still might require revision. It is crucial to be prepared with special tools, including a femoral head extraction tool and diamond saw. The patient has to be informed of the possibility of a more extensive operation than preoperatively planned. LEVEL OF EVIDENCE: Level III, therapeutic study.

Proximal Opening Wedge Osteotomy Provides Satisfactory Midterm Results With a Low Complication Rate.

Hallux valgus is one of the most common foot deformities. Proximal opening wedge osteotomy is used for the treatment of moderate and severe hallux valgus with metatarsus primus varus. However, hypermobility of the first tarsometatarsal joint can compromise the results of the operation, and a paucity of midterm results are available regarding proximal open wedge osteotomy surgery. The aim of the present study was to assess the midterm results of proximal open wedge osteotomy in a consecutive series of patients with severe hallux valgus. Thirty-one consecutive adult patients (35 feet) with severe hallux valgus underwent proximal open wedge osteotomy. Twenty patients (35.5%) and 23 feet (34.3%) were available for the final follow-up examination. The mean follow-up duration was 5.8 (range 4.6 to 7.0) years. The radiologic measurements and American Orthopaedic Foot and Ankle Society hallux-metatarsophalangeal-interphalangeal scores were recorded pre- and postoperatively, and subjective questionnaires were completed and foot scan analyses performed at the end of the follow-up period. The mean hallux valgus angle decreased from 38° to 23°, and the mean intermetatarsal angle correction decreased from 17° to 10°. The mean improvement in the American Orthopaedic Foot and Ankle Society hallux metatarsophalangeal-interphalangeal score increased from 52 to 84. Two feet (5.7%) required repeat surgery because of recurrent hallux valgus. No nonunions were identified. Proximal open wedge osteotomy provided satisfactory midterm results in the treatment of severe hallux valgus, with a low complication rate. The potential instability of the first tarsometatarsal joint does not seem to jeopardize the midterm results of the operation.

Predictors of treatment outcome in prosthetic joint infections treated with prosthesis retention.

PURPOSE: The reported success rates of debridement, antibiotics, and implant retention (DAIR) for prosthetic joint infections (PJIs) vary widely. Several risk factors have been described for treatment failure, but they vary between studies. The purpose of this study was to evaluate the predictors of DAIR failure in PJI treatment and to assess the efficacy of rifampin combined with ciprofloxacin versus rifampin combined with other antibiotics in staphylococcal PJIs. METHODS: Patients with PJI that underwent DAIR for the first time between February 2001 and August 2009 were identified retrospectively in the hospital's patient databases. A total of 113 PJI cases with early postoperative or acute haematogenous PJI were followed for up to two years from the start of treatment. RESULTS: In univariate analysis, variables significantly associated with treatment failure were acute haematogenous infections (p = 0.022), leucocyte count at admission > 10 × 10(9)/l (p < 0.01), pain in the joint (p < 0.01), and ineffective empirical antibiotics (p < 0.01). In a multivariate Cox model, leucocyte count > 10 × 10(9)/l and ineffective empirical antibiotics were significant risk factors for failure. Compared to rifampin-ciprofloxacin, the hazard ratio (HR) for treatment failure was significantly increased in the rifampin-other antibiotics group (HR 6.0, 95% CI 1.5-28.8, p = 0.014) and the group treated without rifampin (HR 14.4, 95% CI 3.1-66.9, p < 0.01). CONCLUSIONS: Rifampin-ciprofloxacin combination therapy was significantly more effective than rifampin combined with other antibiotics. Effective empirical antibiotics are essential for successful PJI treatment.

The reasons for knee arthroplasty revisions are incomparable in the different arthroplasty registries.

BACKGROUND: The arthroplasty registries report the survivorship of knee arthroplasties and the reasons for revisions. The various registries report similar implant survivorships. However, the reasons for the knee revisions have not been compared. The aims of this study were to assess the reasons for knee arthroplasty revisions from the five valid arthroplasty registries and to evaluate whether the reasons for revisions in each registry were similar. METHODS: The reported reasons for knee arthroplasty revisions were extracted from the arthroplasty registries of Australia, New Zealand, Norway, Sweden, and the National Joint Registry for England and Wales. The relevant data were identified from each arthroplasty registry's annual reports. RESULTS: All the arthroplasty registries collected data for each performed knee arthroplasty revision using a specific form. The information provided by the registries varied. The numbers of different variables for the revisions were wide-ranging (from 8-33). In addition to the different variables, the reported percentages between the registries had an extremely wide variation. CONCLUSION: The reasons for knee arthroplasty revisions are categorized differently in various arthroplasty registries, and there is a wide range of percentages presented. The differences in percentages may not be fully explained by the different outcome results in the different countries. The heterogeneity of the registries may guide the recording of the reasons behind the revisions. There is a definite need to standardize the structure of the arthroplasty registries, and to validate the data therein. A larger collaboration between the registries is essential.

The diagnosis and classification of osteonecrosis in patients with childhood leukemia.

Osteonecrosis is a well-recognized complication in patients with childhood leukemia. Its clinical relevance is highly dependent on the size and location of the lesion. Therefore, the diagnosis, description of the affected site and the classification of the disease, must be precise. We conducted an extensive literature review to assess the quality of studies reporting the incidence of osteonecrosis in patients with childhood leukemia. Of the 31 included studies, one-third (32% [n = 10]) did not describe the diagnostic method that was used to assess osteonecrosis. In almost two-third (61% [n = 19]) of the studies, the osteonecrosis classification system was not used. We conclude that the quality of most published studies on the incidence of osteonecrosis in patients with childhood leukemia is relatively poor because many studies did not describe the radiological method used to diagnose osteonecrosis and/or did not use a validated osteonecrosis classification system. To compare the incidence of osteonecrosis, and to assess the severity and clinical consequences of osteonecrosis in patients with childhood leukemia, there is a need for a robust and widely recognized classification system to grade all cases of osteonecrosis despite the site of lesion. Pediatr Blood Cancer 2015;62:198-203. © 2014 Wiley Periodicals, Inc.

Two-stage revision for prosthetic joint infection: outcome and role of reimplantation microbiology in 107 cases.

Two-stage revision is widely used for the treatment of prosthetic joint infections. However, the duration of antibiotic treatment between stages and role of reimplantation microbiology are controversial. The purpose of this study was to evaluate the outcome and influence of the reimplantation microbiology of two-staged revisions with 6 weeks of antibiotic treatment. We retrospectively reviewed 107 patients treated with two-stage revision between 2001 and 2009. The overall treatment success rate was 94.4%. The reimplantation cultures were positive in 5/97 (5.2%) cases, and only one of them failed. Therefore, we achieved excellent results with a 6-week course of antibiotics between stages in two-stage revision. Positive reimplantation cultures do not seem to be associated with worse outcomes.

Total knee arthroplasty after high tibial osteotomy: a registry-based case-control study of 1,036 knees.

INTRODUCTION: Total knee arthroplasty (TKA) after high tibial osteotomy (HTO) is a technically demanding procedure, and concerns have been raised that previous HTO might compromise the outcome of TKA. The aims of the study were to assess the survivorship of TKA after HTO and to determine whether the survivorship is similar to that of primary TKA without previous HTO. MATERIALS AND METHODS: Using the Finnish Arthroplasty Register and the National Hospital Discharge Register, we extracted the data of 1,036 patients [mean age 64.3 years; followup 6.7 years (0-22)] who had undergone TKA after a previous HTO between 1987 and 2008. From this cohort, we calculated the Kaplan-Meier survivorship and compared the survivorship of these cases to that of 4,143 age- and gender-matched patients who had undergone primary TKAs without previous HTO. RESULTS: In the TKA after HTO group, we found Kaplan-Meier survivorship to be 95.3% at 5 years, 91.8% at 10 years, and 88.4% at 15 years. Those survivorship values were lower than those of patients who had TKA without previous HTO (97.2, 94.5, and 90.6%, respectively) (hazard ratio 1.40; 95% confidence interval 1.09-1.81; p = 0.010). CONCLUSIONS: Previous studies have described technical difficulties during the TKA procedure after HTO, but they have found no adverse effects on the outcome. Our study supports previous research, and despite the slightly higher revision rate, TKA after HTO provides satisfactory results when compared to routine primary TKAs.

Unicompartmental knee arthroplasty survivorship is lower than TKA survivorship: a 27-year Finnish registry study.

BACKGROUND: Balancing the relative advantages and disadvantages of unicompartmental knee arthroplasties (UKAs) against those for TKAs can be challenging. Survivorship is one important end point; arthroplasty registers repeatedly report inferior midterm survival rates, but longer-term data are sparse. Comparing survival directly by using arthroplasty register survival reports also may be inadequate because of differences in indications, implant designs, and patient demographics in patients having UKAs and TKAs. QUESTIONS/PURPOSES: The aims of this study were to assess the survivorship of UKA in the context of one large, northern European registry, and to compare the rates of survivorship with those of cemented TKAs performed for primary knee osteoarthritis during the same 27-year period. METHODS: From the Finnish Arthroplasty Register, we obtained the data for 4713 patients undergoing UKAs for primary osteoarthritis (mean age, 63.5 years; minimum followup, 0 years; mean, 6.0 years; range, 0-24 years) who had surgical revision between 1985 and 2011. From this cohort, we calculated the Kaplan-Meier survivorship for revision performed for any reason and compared it with the survivorship of 83,511 patients (mean age, 69.5 years; minimum followup 0 years; mean, 6.4 years; range, 0-27 years) with TKAs treated for primary osteoarthritis during the same period. Data were adjusted for age and sex in a comparative analysis. RESULTS: Kaplan-Meier survivorship of UKAs was 89.4% at 5 years, 80.6% at 10 years, and 69.6% at 15 years; the corresponding rates for TKAs were 96.3%, 93.3%, and 88.7%, respectively. UKAs had inferior long-term survivorship compared with cemented TKAs, even after adjusting for the age and sex of the patients (hazard ratio 2.2, p < 0.001). CONCLUSIONS: A UKA offers tempting advantages compared with a TKA; however, the revision frequency for UKAs in widespread use, as measured in a large, national registry, was poorer than that of TKAs. When choosing between a UKA and a TKA, patients should be informed of advantages of both procedures, but they also should be advised about the generally higher revision risk after UKA. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.