Introduction: Unicompartmental knee arthroplasty (UKA) is a proven for treatment of knee osteoarthritis (OA). Survival rates have been found comparable with total knee arthroplasty (TKA) in specialty hospitals series, but registry based studies show worse results of survival of UKA. High BMI, age of the patient, patellofemoral arthritis or learning curve have been found to have only mild consequences to the survival rates. Original indications for Oxford UKA in OA are severe pain and full thickness cartilage loss with bone-on-bone contact in the medial side. After widespread use of UKA surgeons are broadening their indications. Purpose of this study was to evaluate the influence of preoperative degree of OA on survival rate of UKA. Material and Methods: 113 knees in 103 patients were operated with Oxford phase 3 UKA. We evaluated all the patient data retrospectively and patient age, body mass index (BMI), sex, earlier arthroscopies, operation time, follow-up time, preoperative medial joint space widths, reoperations and survival of UKA was recorded. Results: The mean age of the patients was 58 years (38–81) and mean follow-up time was 47 months (3–114). 22 UKAs were revised and the overall survival rate was 80.5%. 68% of revised knees have had undergone arthroscopy before UKA to confirm existence of arthritis. Odds ratio for female gender was statistically non-significant 1.59 (95% CI 0.57–4.45, p=0.46,). For BMI and patient’s age, the association remained non-significant with odds ratios of 1.07 (95% CI 0.98–1.17, p=0.14) and 0.96 (95% CI 0.90–1.02, p=0.19). Patients were divided four sub-groups according medial joint space width (medial joint space width ≤2 mm and > 2 mm) and Lateral/medial joint space width ratio (L/M-ratio ≤2.5 and > 2.5). Over 2 mm medial joint space width or L/M-ratio less than 2.5 were found significant risk factors for revisions, odds ratios being 6.00 (95% CI 2.12–17.00, p< 0.01) and 7.88 (95% CI 2.76–22.54, p< 0.01), respectively. Discussion: Nowadays UKAs are performed on patients with mild OA against the original indications. In more severe OA varus alignment of the knee causes mechanical overload to the medial compartment, which is well corrected by UKA. Also it is possible that in the cases of prolonged knee pain caution is focused incorrectly to mild OA, which is typical radiological finding even in asymptomatic middle aged and elderly patients. Also in the early phase of OA it is impossible to estimate progression of cartilage damage in other two compartments. In conclusion we suggest that not to extend original indication of UKA and patient should have true medial bone-on-bone OA in preoperative radiographs. Performing UKA for patients with medial joint space width over 2 mm or L/M-ratio less than 2.5 should be concerned particularly careful

Progressive degenerative changes in the medial compartment of the knee following lateral unicompartmental arthroplasty (UKA) remains a leading indication for revision surgery. The purpose of this study is to evaluate changes in the congruence and joint space width (JSW) of the medial compartment following lateral UKA. The congruence of the medial compartment of 53 knees (24 men, 23 women, mean age 13.1 years; sd 62.1) following lateral UKA was evaluated pre-operatively and six weeks post-operatively, and compared with 41 normal knees (26 men, 15 women, mean age 33.7 years; sd 6.4), using an Interactive closest point algorithm which calculated the congruence index (CI) by performing a rigid transformation that best aligns the digitised tibial and femoral surfaces. Inner, middle and outer JSWs were measured by sub-dividing the medial compartment into four quarters on pre- and post-operative, weight bearing tunnel view radiographs. The mean CI of knees following lateral UKA significantly improved from 0.92 (sd 0.06) pre-operatively to 0.96 (sd 0.02) (p < 0.001) six weeks post-operatively. The mean CI of the healthy control group was 0.99 sd 0.01. Post-operatively, the mean inner JSW increased (p = 0.006) and the outer decreased (p = 0.002). The JSW was restored post-operatively as no significant differences were noted in all three locations compared with the control group (inner JSW p = 0.43; middle JSW p = 0.019, outer JSW p = 0.51).

Our data suggest that a well conducted lateral UKA may improve the congruence and normalise the JSW of the medial compartment, potentially preventing progression of degenerative change.

Cite this article: Bone Joint J 2015;97-B:50–5.

In a longitudinal case-control study, we followed 81 subjects with dysplasia of the hip and 136 control subjects without dysplasia for ten years assessing radiological evidence of degeneration of the hip at admission and follow-up. There were no cases of subluxation in the group with dysplasia. Neither subjects with dysplasia nor controls had radiological signs of ongoing degenerative disease at admission. The primary radiological discriminator of degeneration of the hip was a change in the minimum joint space width over time. There were no significant differences between these with dysplasia and controls in regard to age, body mass index or occupational exposure to daily repeated lifting at admission. We found no significant differences in the reduction of the joint space width at follow-up between subjects with dysplasia and the control subjects nor in self-reported pain in the hip. The association of subluxation and/or associated acetabular labral tears with dysplasia of the hip may be a conditional factor for the development of premature osteoarthritis in mildly to moderately dysplastic hips

Introduction. Chronic uneven distribution of forces over the articular cartilage, which are present in OA, has been shown to be a risk factor for the development of OA. Certain regions of the articular cartilage will be exposed to increased chronic peak loads, whereas other regions encounter a corresponding relative reduction of transmitted forces. This has a well known influence on cartilage viability and is a precursor of degenerative progression. Congruence of joints has an important impact on force distribution across articular surfaces. Therefore, tibiofemoral incongruence could lead to alterations of load distribution and ultimately to progressive degenerative changes. In clinical practice the routine method for evaluation of progressive OA is analysis of joint space width (JSW) using weight bearing radiographs. Recent studies have suggested that JSW has a strong positive correlation with cartilage compression, volume and meniscal extrusion. Lateral unicondylar knee arthroplasty (UKA) has gained increasing popularity over the last decade in the treatment of isolated unicompartmental osteoarthritis (OA). However, progressive degenerative alterations of the medial compartment following lateral unicompartmental knee arthroplasty remains a leading cause of revision surgery. Therefore, the purpose of this study is to evaluate the medial compartment congruence (MCC) and joint space width (JSW) alterations following lateral UKA. Methods. The MCC of 53 knees following lateral UKA was evaluated on pre- and postoperative radiographs and compared to 41 healthy knees, using an Interative Closest Point (ICP) algorithm. The ICP algorithm calculated the Congruence Index (CI) by performing a rigid transformation that best aligns the digitized tibial and femoral surfaces (figure 1A). Inner, middle and outer JSW was measured by subdividing the medial compartment into four quarters on weight bearing tunnel view radiographs pre- and postoperatively (figure 1B). Results. The measured CI of the healthy control group was 0.99. The pre-operative CI of knees undergoing lateral UKA was 0.92, which significantly improved to 0.96 (p<0.0001) post-operatively (figure 2). Post-operatively the inner JSW increased (p=0.006) and the outer decreased (p=0.002). JSW was restored post-operatively since no significant differences were noted in all three measured post-operative JSW locations compared to the control group (figure 3). Conclusion. Our data suggests that lateral UKA improves MCC and normalizes JSW of the medial compartment, potentially preventing osteoarthritic progression in the uninvolved medial compartment

Objectives. An important measure for the diagnosis and monitoring of knee osteoarthritis is the minimum joint space width (mJSW). This requires accurate alignment of the x-ray beam with the tibial plateau, which may not be accomplished in practice. We investigate the feasibility of a new mJSW measurement method from stereo radiographs using 3D statistical shape models (SSM) and evaluate its sensitivity to changes in the mJSW and its robustness to variations in patient positioning and bone geometry. Materials and Methods. A validation study was performed using five cadaver specimens. The actual mJSW was varied and images were acquired with variation in the cadaver positioning. For comparison purposes, the mJSW was also assessed from plain radiographs. To study the influence of SSM model accuracy, the 3D mJSW measurement was repeated with models from the actual bones, obtained from CT scans. Results. The SSM-based measurement method was more robust (consistent output for a wide range of input data/consistent output under varying measurement circumstances) than the conventional 2D method, showing that the 3D reconstruction indeed reduces the influence of patient positioning. However, the SSM-based method showed comparable sensitivity to changes in the mJSW with respect to the conventional method. The CT-based measurement was more accurate than the SSM-based measurement (smallest detectable differences 0.55 mm versus 0. 82 mm, respectively). Conclusion. The proposed measurement method is not a substitute for the conventional 2D measurement due to limitations in the SSM model accuracy. However, further improvement of the model accuracy and optimisation technique can be obtained. Combined with the promising options for applications using quantitative information on bone morphology, SSM based 3D reconstructions of natural knees are attractive for further development. Cite this article: E. A. van IJsseldijk, E. R. Valstar, B. C. Stoel, R. G. H. H. Nelissen, N. Baka, R. van’t Klooster, B. L. Kaptein. Three dimensional measurement of minimum joint space width in the knee from stereo radiographs using statistical shape models. Bone Joint Res 2016;320–327. DOI: 10.1302/2046-3758.58.2000626

Background/Objective: Since estrogen receptors (ERα/ERβ) were identified in human chondrocytes, animal-and experimental studies have demonstrated the importance of continued estrogen production for the integrity of articular cartilage. However, human epidemiological support of the hypothesis has been inconclusive. The present study investigated the relationship between reduced bone mineral densities (BMD), as a surrogate parameter of endogenous estrogen status – assessed by digital x-ray radiogrammetry (DXR), and reduced minimum hip joint space width (JSW). Methods: Standardised hand radiographs of the Copenhagen Osteoarthritis Study cohort of 3.913 adults (1.470M/2.443F) with a mean age of 60 years (range, 18–92), were analysed by the X-Posure. ™. digital software v. 2.0 (Sectra-Pronosco). The system is operator independent. From 1.200 individual measurements per radiograph mean BMD was calculated. Minimum hip joint JSW was assessed in standardized, pelvic radiographs. Results: DXR-BMD decreased in both men and women after the age of 45 years, progressively more so in women. While minimum hip JSW in men remained relatively unaltered throughout life, a marked decline in female minimum hip JSW after 45 years was observed. We found moderate, but highly significant relationships between reduced BMD and reduced hip JSW in women (p < 0.001), adjusted for age and dysplastic joint incongruity. Conclusion: We believe that the present study supports the hypothetical relationship between reduced estrogen levels and hip joint space width reduction in women

Objectives. The purpose of this study was to compare the joint space width between one-leg and both-legs standing radiographs in order to diagnose a primary osteoarthritis of the knee. Methods. Digital radiographs of 100 medial osteoarthritic knees in 50 patients were performed. The patients had undergone one-leg standing anteroposterior (AP) views by standing on the affected leg while a both-legs standing AP view was undertaken while standing on both legs. The severity of the osteoarthritis was evaluated using the joint space width and Kellgren-Lawrence (KL) radiographic classification. The t-test was used for statistical analysis. Results. The mean medial joint space width found in the one-leg and in the both-legs standing view were measured at 1.8 mm and 2.4 mm, respectively (p < 0.001, 95% CI 0.5 to 0.7). 33%, 47.4% and 23.1% of the knees diagnosed with a KL grade of I, II and III in the both-legs standing views were changed to KL grade II, III and IV in the one-leg standing views, respectively. No changes for KL IV osteoarthritis diagnoses have been found between both- and one-leg standing views. Conclusions. One-leg standing radiographs better represent joint space width than both-legs standing radiographs. 32% of both-legs standing radiographs have changed the KL grading to a more severe grade than that in the one-leg standing radiographs. Cite this article: P. Pinsornsak, K. Naratrikun, S. Kanitnate, T. Sangkomkamhang. The one-leg standing radiograph: An improved technique to evaluate the severity of knee osteoarthritis. Bone Joint Res 2016;5:436–441. DOI: 10.1302/2046-3758.59.BJR-2016-0049.R1

Varus malalignment increases the susceptibility of cartilage to mechanical overloading, which stimulates catabolic metabolism to break down the extracellular matrix and lead to osteoarthritis (OA). The altered mechanical axis from the hip, knee to ankle leads to knee joint pain and ensuing cartilage wear and deterioration, which impact millions of the aged population. Stabilization of the remaining damaged cartilage, and prevention of further deterioration, could provide immense clinical utility and prolong joint function. Our previous work showed that high tibial osteotomy (HTO) could shift the mechanical stress from an imbalanced status to a neutral alignment. However, the underlying mechanisms of endogenous cartilage stabilization after HTO remain unclear. We hypothesize that cartilage-resident mesenchymal stem cells (MSCs) dampen damaged cartilage injury and promote endogenous repair in a varus malaligned knee. The goal of this study is to further examine whether HTO-mediated off-loading would affect human cartilage-resident MSCs' anabolic and catabolic metabolism. This study was approved by IACUC at Xi'an Jiaotong University. Patients with medial compartment OA (52.75±6.85 yrs, left knee 18, right knee 20) underwent open-wedge HTO by the same surgeons at one single academic sports medicine center. Clinical data was documented by the Epic HIS between the dates of April 2019 and April 2022 and radiographic images were collected with a minimum of 12 months of follow-up. Medial compartment OA with/without medial meniscus injury patients with unilateral Kellgren /Lawrence grade 3–4 was confirmed by X-ray. All incisions of the lower extremity healed well after the HTO operation without incision infection. Joint space width (JSW) was measured by uploading to ImageJ software. The Knee injury and Osteoarthritis Outcome Score (KOOS) toolkit was applied to assess the pain level. Outerbridge scores were obtained from a second-look arthroscopic examination. RNA was extracted to quantify catabolic targets and pro-inflammatory genes (QiaGen). Student's t test for two group comparisons and ANOVA analysis for differences between more than 2 groups were utilized. To understand the role of mechanical loading-induced cartilage repair, we measured the serial changes of joint space width (JSW) after HTO for assessing the state of the cartilage stabilization. Our data showed that HTO increased the JSW, decreased the VAS score and improved the KOOS score significantly. We further scored cartilage lesion severity using the Outerbridge classification under a second-look arthroscopic examination while removing the HTO plate. It showed the cartilage lesion area decreased significantly, the full thickness of cartilage increased and mechanical strength was better compared to the pre-HTO baseline. HTO dampened medial tibiofemoral cartilage degeneration and accelerate cartilage repair from Outerbridge grade 2 to 3 to Outerbridge 0 to 1 compared to untreated varus OA. It suggested that physical loading was involved in HTO-induced cartilage regeneration. Given that HTO surgery increases joint space width and creates a physical loading environment, we hypothesize that HTO could increase cartilage composition and collagen accumulation. Consistent with our observation, a group of cartilage-resident MSCs was identified. Our data further showed decreased expression of RUNX2, COL10 and increased SOX9 in MSCs at the RNA level, indicating that catabolic activities were halted during mechanical off-loading. To understand the role of cartilage-resident MSCs in cartilage repair in a biophysical environment, we investigated the differentiation potential of MSCs under 3-dimensional mechanical loading conditions. The physical loading inhibited catabolic markers (IL-1 and IL-6) and increased anabolic markers (SOX9, COL2). Knee-preserved HTO intervention alleviates varus malalignment-related knee joint pain, improves daily and recreation function, and repairs degenerated cartilage of medial compartment OA. The off-loading effect of HTO may allow the mechanoregulation of cartilage repair through the differentiation of endogenous cartilage-derived MSCs

Introduction. Wear of polyethylene inserts plays an important role in failure of total knee replacement and can be monitored in vivo by measuring the minimum joint space width in anteroposterior radiographs. The objective of this retrospective cross-sectional study was to compare the accuracy and precision of a new model-based method with the conventional method by analysing the difference between the minimum joint space width measurements and the actual thickness of retrieved polyethylene tibial inserts. . Method. Before revision, the minimum joint space width values and their locations on the insert were measured in 15 fully weight-bearing radiographs. These measurements were compared with the actual minimum thickness values and locations of the retrieved tibial inserts after revision. . Results. The mean error in the model-based minimum joint space width measurement was significantly smaller than the conventional method for medial condyles (0.50 vs 0.94 mm, p < 0.01) and for lateral condyles (0.06 vs 0.34 mm, p = 0.02). The precision (standard deviation of the error) of the methods was similar (0.84 vs 0.79 mm medially and both 0.46 mm laterally). The distance between the true minimum joint space width locations and the locations from the model-based measurements was less than 10 mm in the medial direction in 12 cases and less in the lateral direction in 13 cases. Conclusion. The model-based minimum joint space width measurement method is more accurate than the conventional measurement with the same precision. Cite this article: Bone Joint Res 2014;3:289–96

The primary treatment goal for patients with femoroacetabular impingement syndrome, a common hip condition in athletes, is to improve pain and function. In selected patients, in the short term following intervention, arthroscopic hip surgery is superior to a pragmatic NHS- type physiotherapy programme. Here, we report the three-year follow-up results from the FemoroAcetabular Impingement Trial (FAIT), comparing arthroscopic hip surgery with physiotherapy in the management of patients with femoroacetabular impingement (FAI) syndrome. Two-group parallel, assessor-blinded, pragmatic randomised controlled study across seven NHS England sites. 222 participants aged 18 to 60 years with FAI syndrome confirmed clinically and radiologically were randomised (1:1) to receive arthroscopic hip surgery (n = 112) or physiotherapy and activity modification (n = 110). We previously reported on the hip outcome score at eight months. The primary outcome measure of this study was minimum Joint Space Width (mJSW) on Anteroposterior Radiograph at 38 months post randomisation. Secondary outcome measures included the Hip Outcome Score and Scoring Hip Osteoarthritis with MRI (SHOMRI) score. Minimum Joint Space Width data were available for 101 participants (45%) at 38 months post randomisation. Hip outcome score and MRI data were available for 77% and 62% of participants respectively. mJSW was higher in the arthroscopy group (mean (SD) 3.34mm (1.01)) compared to the physiotherapy group (2.99mm (1.33)) at 38 months, p=0.017, however this did not exceed the minimally clinically important difference of 0.48mm. SHOMRI score was significantly lower in the arthroscopy group (mean (SD) 9.22 (11.43)) compared to the physiotherapy group (22.76 (15.26)), p-value <0.001. Hip outcome score was higher in the arthroscopy group (mean (SD) 84.2 (17.4)) compared with the physiotherapy group (74.2 (21.9)), p-value < 0.001). Patients with FAI syndrome treated surgically may experience slowing of osteoarthritisprogression and superior pain and function compared with patients treated non- operatively

Aims. To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics. Methods. Cemented Phase 3 medial Oxford UKA implanted by two surgeons since 1998 for the recommended indications were prospectively followed. A 15-year cumulative revision rate for lateral OA of 5% for this series was previously reported. A total of 163 unrevised knees with 15-year (SD 1) anterior-posterior knee radiographs were studied. Lateral joint space width (JSW. L. ) was measured and severity of lateral OA was classified as: nil/mild, moderate, and severe. Preoperative and 15-year Oxford Knee Scores (OKS) and American Knee Society Scores were determined. The effect of age, sex, BMI, and intraoperative findings was analyzed. Statistical analysis included one-way analysis of variance and Kruskal-Wallis H test, with significance set at 5%. Results. The mean age was 80.6 years (SD 8.3), with 84 females and 79 males. The mean JSW. L. was 5.6 mm (SD 1.4), and was not significantly related to age, sex, or intraoperative findings. Those with BMI > 40 kg/m. 2. had a smaller JSW. L. than those with a ‘normal’ BMI (p = 0.039). The incidence of severe and moderate lateral OA were both 4.9%. Overall, 2/142 (1.4%) of those with nil/mild lateral OA, 1/8 (13%) with moderate, and 2/8 (25%) with severe subsequently had a revision. Those with severe (mean OKS 35.6 (SD 9.3)) and moderate OA (mean OKS 35.8 (SD 10.5)) tended to have worse outcome scores than those with nil/mild (mean OKS 39.5 (SD 9.2)) but the difference was only significant for OKS-Function (p = 0.044). Conclusion. This study showed that the rate of having severe or moderate radiological lateral OA at 15 years after medial UKA was low (both 4.9%). Although patients with severe or moderate lateral OA had a lower OKS than those with nil/mild OA, their mean scores (OKS 36) would be classified as good. Cite this article: Bone Jt Open 2023;4(3):210–218

Aims. Rotational acetabular osteotomy (RAO) has been reported to be effective in improving symptoms and preventing osteoarthritis (OA) progression in patients with mild to severe develomental dysplasia of the hip (DDH). However, some patients develop secondary OA even when the preoperative joint space is normal; determining who will progress to OA is difficult. We evaluated whether the preoperative cartilage condition may predict OA progression following surgery using T2 mapping MRI. Methods. We reviewed 61 hips with early-stage OA in 61 patients who underwent RAO for DDH. They underwent preoperative and five-year postoperative radiological analysis of the hip. Those with a joint space narrowing of more than 1 mm were considered to have 'OA progression'. Preoperative assessment of articular cartilage was also performed using 3T MRI with the T2 mapping technique. The region of interest was defined as the weightbearing portion of the acetabulum and femoral head. Results. There were 16 patients with postoperative OA progression. The T2 values of the centre to the anterolateral region of the acetabulum and femoral head in the OA progression cases were significantly higher than those in patients without OA progression. The preoperative T2 values in those regions were positively correlated with the narrowed joint space width. The receiver operating characteristic analysis revealed that the T2 value of the central portion in the acetabulum provided excellent discrimination, with OA progression patients having an area under the curve of 0.858. Furthermore, logistic regression analysis showed T2 values of the centre to the acetabulum’s anterolateral portion as independent predictors of subsequent OA progression (p < 0.001). Conclusion. This was the first study to evaluate the relationship between intra-articular degeneration using T2 mapping MRI and postoperative OA progression. Our findings suggest that preoperative T2 values of the hip can be better prognostic factors for OA progression than radiological measures following RAO. Cite this article: Bone Joint J 2021;103-B(9):1472–1478

Aims. To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty. Methods. We retrospectively reviewed 639 subjects, aged 45 to 79 years, in the Osteoarthritis Initiative (OAI) study, who had symptomatic knees with Kellgren and Lawrence grade 2 to 4. Knees were categorized as neutral, valgus, and varus knees by measuring hip-knee-angles on hip-knee-ankle radiographs. Femorotibial JSW was measured on posteroanterior SF radiographs using a special software. The femorotibial compartment was divided into 16 subregions, and MR-tomographic measurements of cartilage volume, thickness, and subchondral bone area were documented. Linear regression with adjustment for age, sex, body mass index, and Kellgren and Lawrence grade was used. Results. We studied 345 neutral, 87 valgus, and 207 varus knees. Radiological JSW narrowing was significantly (p < 0.01) associated with cartilage volume and thickness in medial femorotibial compartment in neutral (r = 0.78, odds ratio (OR) 2.33) and varus knees (r = 0.86, OR 1.92), and in lateral tibial subregions in valgus knees (r = 0.87, OR 3.71). A significant negative correlation was found between JSW narrowing and area of subchondral bone in external lateral tibial subregion in valgus knees (r = −0.65, p < 0.01) and in external medial tibial subregion in varus knees (r = −0.77, p < 0.01). No statistically significant correlation was found in anterior and posterior subregions. Conclusion. SF radiographs can be potentially used for initial detection of cartilage degeneration as assessed by MRI in medial and lateral but not in anterior or posterior subregions. Cite this article: Bone Joint Res 2021;10(3):173–187

Knee joint distraction (KJD) has been associated with clinical and structural improvement and synovial fluid (SF) marker changes. However, structural changes have not yet been shown satisfactorily in regular care, since radiographic acquisition was not fully standardized. AI-based modules have shown great potential to reduce reading time, increase inter-reader agreement and therefore function as a tool for treatment outcome assessment. The objective was to analyse structural changes after KJD in patients using this AI-based measurement method, and relate these changes to clinical outcome and SF markers. 20 knee OA patients (<65 years old) were included in this study. KJD treatment was performed using an external fixation device, providing 5 mm distraction for 6 weeks. SF was aspirated before, during and immediately after treatment. Weight-bearing antero-posterior knee radiographs and WOMAC questionnaires were collected before and ~one year after treatment. Radiographs were analysed with the Knee Osteoarthritis Labelling Assistant (KOALA, IB Lab GmbH, Vienna, Austria), and 10 pre-defined biomarker levels in SF were measured by immunoassay. Radiographic one-year changes were analysed and linear regression was used to calculate associations between changes in standardized joint space width (JSW) and WOMAC, and changes in JSW and SF markers. After treatment, radiographs showed an improvement in Kellgren-Lawrence grade in 7 of 16 patients that could be evaluated; 3 showed a worsening. Joint space narrowing scores and continuous JSW measures improved especially medially. A greater improvement in JSW was significantly associated with a greater improvement in WOMAC pain (β=0.64;p=0.020). A greater increase in MCP1 (β=0.67;p=0.033) and lower increase in TGFβ1 (β=-0.787;p=0.007) were associated with JSW improvement. Despite the small number of patients, also in regular care KJD treatment shows joint repair as measured automatically on radiographs, significantly associated with certain SF marker change and even with clinical outcome

It is unclear whether patients with early radiographic osteoarthritis (OA) but severe hip symptoms benefit from total hip replacement (THR). We aimed to assess which factors were associated with successful THR in this patient group. From a consecutive series of 1,935 patients undergoing THR we identified 70 (3.6%) patients with early OA (Kellgren and Lawrence (KL) grades 0-2). These were compared with 200 patients with advanced OA (KL grades 3–4). Outcomes were Oxford Hip Scores (OHS), EQ5D and EQ-VAS scores; compared pre-operatively with one year post-operatively. We investigated which clinical and radiographic (plain x-ray, CT, MRI) features predicted successful THR in the early OA group. Success was defined as reaching a postoperative OHS≥42. The early OA group were significantly younger (61 vs 66 years; P=0.0035). There were no significant differences in body mass index, ASA grade or gender. After adjusting for confounders, the advanced OA group had a significantly greater percentage of possible change (PoPC) in OHS (75.8% versus 50.4%; P<0.0001) and improvement in EQ5D (0.151 versus 0.002; P<0.0001). There were no significant differences in complication, revision or readmission rates. In the early OA group, we identified 16/70 (22.9%) patients who had a ‘successful’ THR. Of those with early OA, 38 patients had pre-operative CT or MRI scans. Patients who had a ‘successful’ THR were significantly more likely to have subchondral cysts on CT/MRI (91.7% versus 57.7%; P=0.0362). The presence of cysts on CT/MRI was associated with a significantly greater PoPC in OHS (61.6% versus 38.2%; P=0.0353). The combination of cysts and joint space width (JSW) <1mm was associated with a PoPC of 68%. Plain radiographs were found to significantly underestimate the narrowest JSW compared to CT/MRI (2.4mm versus 1.0mm; P<0.0001). We advise caution in performing THRs in patients with early OA (KL grades 0-2) on plain radiographs. We advocate pre-operative cross-sectional imaging (CT or MRI) in these patients. In the absence of cysts on cross-sectional imaging, a THR seems unlikely to provide a satisfactory outcome

Aim: The aim of the study was to assess the correlation of CE angle to the ratios of medial hip joint space width and femoral head diameter to acetabular width. Material and metod: Measurements were done on 196 AP pelvic radiographs of 10 years old and 20 years old males and females obtained with “siemens lconos r 200 axion. ®. ”. The patients were placed in the supine position with their hips extended and internally rotated 15°. Medial hip joint space width (mJSW), CE angle, femoral head diameter (FD) and acetabular width (AW) were measured. The intraobserver reproducibility was assessed by a randomly chosen subset of 50 radiographs and these were read 1 month apart. The levels of agreement were qualified using the intraclass correlation coefficient. The ratios of mJSW to AW and FD to AW were calculated. Results: Mean CE angles in 10 years old females and males were 33.87±3.64 ve 32.74±4.21 degrees respectively. CE angle was correlated to mJSW/AW in 10 years old females (r = − 0.446, p=0.043). CE angle was not correlated to mJSW/AW in 10 years old males (r = − 0.293, p=0.146). CE angle was not correlated to mJSW/AW in 20 years old females while CE angle was correlated to mJSW/AW in 20 years old males (r = 0. 694, p=0.001). CE angle was correlated to FD/AW only in 20 years old males (r=0.553, p= 0.002). Discussion: Ratios of medial hip joint space width and femoral head diameter to acetabular width are not correlated to CE angle in both preadelocent and postade-locent terms depending on sex. The expected inverse correlation of these parameters to CE angle was not dedected, so these parameters can be used in radiologic assessement of subluxation of the hip and acetabular dysplasia together with CE angle

Introduction and Objective. To estimate the prevalence of acetabular ossifications in the adult population with asymptomatic, morphologically normal hips at CT and to determine whether the presence of labral ossifications is associated with patient-related (sex, age, BMI), or hip-related parameters (joint space width, and cam- and pincer-type femoroacetabular impingement morphotype). Materials and Methods. We prospectively included all patients undergoing thoracoabdominal CT over a 3-month period. After exclusion of patients with a clinical history of hip pathology and/or with signs of osteoarthritis on CT, we included a total of 150 hips from 75 patients. We analyzed the presence and the size of labral ossifications around the acetabular rim. The relationships between the size of labral ossifications and patient- and hip-related parameters were tested using multiple regression analysis. Results. The prevalence of labral ossifications in this population of asymptomatic, non-OA hips was 96% (95%CI=[80.1; 100.0]). The presence of labral ossifications and their size were correlated between right and left hips (Spearman coefficient=0.64 (95%CI=[0.46; 0.79]), p<0.05)). The size of labral ossifications was significantly associated with age (p<0.0001) but not with BMI (p=0.35), gender (p=0.05), joint space width (p≥0.53 for all locations) or any of the qualitative or quantitative parameters associated with femoroacetabular morphotype (all p≥0.34). Conclusions. Labral ossifications are extremely common in asymptomatic, non-osteoarthritic hips. Their size is not correlated with any patient-, or hip-related parameters except for the age. These findings suggest that the diagnosis of osteoarthritis or femoroacetabular impingement morphotype should not be made based on the sole presence of acetabular labral ossifications

Purpose: The aetiology of primary omarthrosis is still unclear. Typical radiological changes are joint space narrowing and the development of caudal osteophytes. The objective of the study is the analysis of the joint space of the shoulder in four different age groups. Materials and Methods: Retrospective analysis of n=342 standardized X-rays (2002–2009) (true ap, axillary). Inclusion criteria: normal adulthood group I (n=60), instability group II (n=53), calcifying tendonitis of the supraspinatus tendon group III (n=109), advanced primary omarthrosis group IV (n=120). Measurement of joint space at three levels (ap: superior, central, inferior; axillary: anterior, central, posterior). Two independent measurements. Statistical analysis SPSS 17.0: U-Test acc. Mann and Whitney. Bivariate correlation analysis (Spearman), partial correlation analysis, intraclass correlation coefficient. Results: Mean age group I 17.84±1.54, group II 31.6±11.8, group III 48.2±8.0, group IV 66.43 ±9.74 (p=0.001). Measurement joint space: interobserver reliability excellent in the ap-projection (r=0.887–0.910) and in the axillary projection (r=0.879–0.886). Joint space group I: 4.79mm±0.84 superior ap, 4.28mm±0.75 central ap, 4.57mm±0.80 inferior ap, 6.59mm±1.44 anterior axillary, 6.12mm±1.09 central axillary and 7.03mm±1.17 posterior axillary; group II: 3.78mm±0.99 superior ap, 3.12mm±0.73 central ap, 3.38mm±0.80 inferior ap, 3.92mm±1.08 anterior axillary, 3.92mm±0.77 central axillary and 4.79mm±1.18 posterior axillary; group III: 3.43mm±1.06 superior ap, 2.87mm±0.80 central ap, 3.25mm±0.79 inferior ap, 3.95mm±0.83 anterior axillary, 3.34mm±0.84 central axillary and 4.05mm±0.84 posterior axillary; group IV: 2.00mm±1.40 superior ap, 1.47mm±1.07 central ap, 1.48mm±1.93 inferior ap, 3.01mm±2.22 anterior axillary, 1.08mm±1.12 central axillary and 1.17mm±1.04 posterior axillary. The differences between the four groups for the joint space width are all statistically significant with p< 0.001 (except the difference between group I and group II for ap-central, ap-inferior and axillary anterior). There is a significant negative correlation (r= −0,579–0,813) between the joint space width and patients age at all measured levels in both projections (p< 0.001). This negative correlation is only little smaller (r= −0,430–0,655) but still clearly significant for all measurements, if the patients with present osteoarthritis (group III) are excluded. Conclusion: The data of the study show a decrease of joint space width in group I–IV in all measurements. This effect is negatively correlated with age. The data suggest that the decrease in joint space with loss of cartilage cover is an age-dependant process which is independent from the presence of osteoarthritis. This is in contrast to historical findings but in concordance with recent basic studies about cartilage ageing

Summary. In this study we validate that weight-bearing images are needed for accurate polyethylene liner wear measurement in total knee prostheses by measuring the difference in minimum joint space width between weight-bearing and non-weight-bearing RSA views. Introduction. Recent studies show that Model-based Roentgen Stereophotogrammetric Analysis is superior to the conventional in vivo measurements of polyethylene liner wear in total knee prostheses. Although it is generally postulated that weight-bearing (standing) views are required to detect liner wear, most RSA images are acquired in non-weight-bearing (supine) view for practical reasons. Therefore, it would be of interest to know if supine views would be sufficient for measuring TKA liner wear, defined as a change in minimum joint space width (mJSW). As a difference in mJSW between weight-bearing and non-weight-bearing RSA images has never been validated, the aim of this study is to compare the outcome of in vivo measurements of mJSW in total knee prosthesis when conducted with weight-bearing and non-weight-bearing RSA views. Method. We selected the first 16 patients with a Triathlon total knee prosthesis from a clinical study for which subsequently a weight-bearing eand a non-weight-bearing RSA image pair were acquired at one year follow up. For both images the mJSW and the corresponding contact point locations in terms of mediolateral (ML) and anterioposterior (AP) coordinates were measured. In addition, the ML stability was scored to assess knee laxity. The size of the mJSW difference between non-weight-bearing and weight-bearing views was determined and a regression analysis was conducted to investigate the effect of knee laxity to this difference, while correcting for differences between the contact point locations. Results. On average, the measured mJSW was 0.22 mm larger in the non-weight-bearing views (T-test, p < 0.05). The standard deviation of the difference was 0.22 mm. The regression analysis showed that a difference in the ML position of the contact location was an important covariate (beta = 0.255±0.054, Wald 95% CI). 13 patients had a high ML stability (< 5 deg) and three had a medium stability (5–10 deg). The regression analysis showed that on average patients with medium ML stability had a 0.17 mm larger difference in mJSW than patients with a high ML stability. Conclusion. The study shows that the mJSW is larger in non-weight-bearing views. The differences found are clinically relevant, as wear rates in practice are as small as 0.1 mm per year. Hereby it is validated that weight-bearing RSA images are more capable of detecting the mJSW in total knee prostheses. The size of the difference in mJSW between the views seems to be in relation with the knee laxity

Background. A consecutive series of 76 patients (101 hips) underwent primary open reduction, capsulorrhaphy and innominate osteotomy for late presenting developmental hip dislocation. They were aged 1.5 to 5 years at the time of surgery between 1958 and 1965. This study was designed to review their outcome into middle age. Methods. We located and reviewed 60 patients (80 hips) using a public records search. This represents a 79% rate of follow-up at 40-48 years post-operatively. 19 patients (24 hips) had undergone total hip replacement and 3 had died. The remaining 38 patients (53 surviving hips) were assessed by the WOMAC. ¯. and Oxford hip outcome questionnaires, physical examination and standing pelvic radiograph. The radiographs were analysed for minimum joint space width and the Kellgren and Lawrence score. Accepted indices of hip dysplasia were measured. Results. Kaplan-Meier survival analysis is presented using the end point of total hip replacement. Survival rates at 30, 40 and 45 years post-reduction are 99% (95% CI +/−2.4), 86% (+/− 6.9) and 54% (+/−16.4) respectively. Average Oxford and WOMAC. ¯. scores for surviving hips were 16.8 (range 0-82) and 16.7 (range 0-71) respectively. Of 51 surviving hip radiographs, 38 had a minimum joint space width in excess of 2.0mm, 13 had definite osteoarthritis (OA) on this criterion. 29 were Kellgren and Lawrence grade 0/1(no or doubtful signs of OA), 7 grade 2 (mild OA), 15 grade 3 or 4 (moderate or severe OA). The average centre-edge and acetabular angles were 40° (range 0-61°) and 32° (20-43°) respectively. There was no significant association between outcome and the modifiable risk factors of body mass or age at surgery. Conclusion. This method of treatment achieves a 54% rate of hip survival at 45 years. Two thirds of surviving hips have an excellent prognosis at this stage