The Unified Classification System (UCS) was introduced because of a growing need to have a standardised universal classification system of periprosthetic fractures. It combines and simplifies many existing classification systems, and can be applied to any fracture around any partial or total joint replacement occurring during or after operation. Our goal was to assess the inter- and intra-observer reliability of the UCS in association with knee replacement when classifying fractures affecting one or more of the femur, tibia or patella. We used an international panel of ten orthopaedic surgeons with subspecialty fellowship training and expertise in adult hip and knee reconstruction (‘experts’) and ten residents of orthopaedic surgery in the last two years of training (‘pre-experts’). They each received 15 radiographs for evaluation. After six weeks they evaluated the same radiographs again but in a different order. . The reliability was assessed using the Kappa and weighted Kappa values. The Kappa values for inter-observer reliability for the experts and the pre-experts were 0.741 (95% confidence interval (CI) 0.707 to 0.774) and 0.765 (95% CI 0.733 to 0.797), respectively. The weighted Kappa values for intra-observer reliability for the experts and pre-experts were 0.898 (95% CI 0.846 to 0.950) and 0.878 (95% CI 0.815 to 0.942) respectively. The UCS has substantial inter-observer reliability and ‘near perfect’ intra-observer reliability when used for periprosthetic fractures in association with knee replacement in the hands of experienced and inexperienced users. Cite this article: Bone Joint J 2014;96-B:1669–73

Aims. The primary objective of this study was to develop a validated classification system for assessing iatrogenic bone trauma and soft-tissue injury during total hip arthroplasty (THA). The secondary objective was to compare macroscopic bone trauma and soft-tissues injury in conventional THA (CO THA) versus robotic arm-assisted THA (RO THA) using this classification system. Methods. This study included 30 CO THAs versus 30 RO THAs performed by a single surgeon. Intraoperative photographs of the osseous acetabulum and periacetabular soft-tissues were obtained prior to implantation of the acetabular component, which were used to develop the proposed classification system. Interobserver and intraobserver variabilities of the proposed classification system were assessed. Results. The BOne trauma and Soft-Tissue Injury classification system in total Hip arthroplasty (BOSTI Hip) grades osseous acetabular trauma and periarticular muscle damage during THA. The classification system has an interclass correlation coefficient of 0.90 (95% CI 0.86 to 0.93) for interobserver agreement and 0.89 (95% CI 0.84 to 0.93) for intraobserver agreement. RO THA was associated with improved BOSTI Hip scores (p = 0.002) and more pristine osseous surfaces in the anterior superior (p = 0.001) and posterior superior (p < 0.001) acetabular quadrants compared with CO THA. There were no differences between the groups in relation to injury to the gluteus medius (p = 0.084), obturator internus (p = 0.241), piriformis (p = 0.081), superior gamellus (p = 0.116), inferior gamellus (p = 0.132), quadratus femoris (p = 0.208), and vastus lateralis (p = 0.135), but overall combined muscle injury was reduced in RO THA compared with CO THA (p = 0.023). Discussion. The proposed BOSTI Hip classification provides a reproducible grading system for stratifying iatrogenic bone trauma and soft-tissue injury during THA. RO THA was associated with improved BOSTI Hip scores, more pristine osseous acetabular surfaces, and reduced combined periarticular muscle injury compared with CO THA. Further research is required to understand if these intraoperative findings translate to differences in clinical outcomes between the treatment groups. Cite this article: Bone Joint J 2024;106-B(9):898–906

Complications are an inevitable part of orthopaedic surgery, how one defines complications can have an impact on the ability to learn from them. A group of general surgeons headed by Clavien and Dindo et al.1 have previously published their classification system for surgical complications based on the type of therapy required to correct the complication. Our aim was to evaluate a modification of this classification system and its use over a 12-month period at our institution via our departmental audits, our hypothesis being that this would direct appropriate discussion around our complications and hence learning and institutional change. A modified Clavien-Dindo Classification was prospectively applied to all complications recorded in the Orthopaedic departmental quarterly audits at our institution for a 12-month period (4 audits). The audit discussion was recorded and analysed and compared with the quarterly complication audits for the preceding 12-month period. The modified Clavien-Dindo classification for surgical complications was applicable and reproducible to Orthopaedic complications in our level 1 trauma centre. It is a transparent system, objective in its interpretation and avoids the tendency to down-grade serious complications. It was easy to apply and directed discussion appropriately at our quarterly audit meetings on complications where there was a preventable outcome or important learning point. In particular modifications to VTE and Death classes allowed the unit to focus discussion on cases where complication was preventable or unexpected. The modified Clavien-Dindo classification system is an easy to use and reproducible classification system for Orthopaedic complications in our unit it directed audit discussion towards cases where complications were preventable or had a learning point

There is good scientific rationale to support the use of growth factors to promote musculoskeletal tissue regeneration. However, the clinical effectiveness of platelet-rich plasma (PRP) and other blood-derived products has yet to be proven. Characterization and reporting of PRP preparation protocols utilized in clinical trials for the treatment of musculoskeletal disease is highly inconsistent, and the majority of studies do not provide sufficient information to allow the protocols to be reproduced. Furthermore, the reporting of blood-derived products in orthopaedics is limited by the multiple PRP classification systems available, which makes comparison of results between studies challenging. Several attempts have been made to characterize and classify PRP; however, no consensus has been reached, and there is lack of a comprehensive and validated classification. In this annotation, we outline existing systems used to classify preparations of PRP, highlighting their advantages and limitations. There remains a need for standardized universal nomenclature to describe biological therapies, as well as a comprehensive and reproducible classification system for autologous blood-derived products. Cite this article: Bone Joint J 2019;101-B:891–896

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone. Cite this article: Bone Joint J 2023;105-B(5):481–486

INTRODUCTION. The Dorr Bone Classification, devised in 1993 is commonly used to categorize bone types prior to hip reconstruction. The purpose of the present study is to quantify the Dorr classification system using 4 morphologic parameters – morphologic cortical index (MCI), canal-flare index (CFI), canal-bone ratio (CBR), and canal-calcar ratio (CCR). METHODS. 816 hips were reviewed. Demographic data reviewed includes age, sex, and laterality. Each hip was reviewed by 2 separate evaluators for Dorr classification. The MCI, CCR, CBR, and CFI were calculated for each hip on anteroposterior radiographs (Fig 1). One-way ANOVA statistical analysis was used to examine if there are mean differences for each measurement. IRB approval was obtained before collection of data. RESULTS. The average age of patients was 61 (range 20–96). There were 367 left hips and 449 right hips. The prevalence of Dorr A was 45.8%. The prevalence of Dorr B bone was 38.9% and of Dorr C bone was 15.3%. One-way ANOVA analysis confirmed the mean differences for each measurement. Measurements of the MCI, CCR, CBR, and CFI were statistically significantly different between the three types of bone. The MCI and CFI were significantly higher in Type A than Type B and higher in Type B than Type C. The CBR and CCR were significantly lower in Type A than Type B and lower in Type B than Type C. DISCUSSION. To our knowledge, the present study is the first to attempt to quantify the Dorr Bone classification system using MCI, CCR, CBR, and CFI using a large series of patients. Classification of the proximal femur geometry is important as it may play a role in implant fixation for patients undergoing total hip arthroplasty (THA). Furthermore, this information can be used to guide future implant choices

The Gartland extension-type supracondylar humerus fracture is the most common elbow fracture in the paediatric population. Depending on fracture classification, treatment options range from nonoperative treatment such as taping, splinting or casting to operative treatments such as closed reduction and percutaneous pinning or open reduction. Classification variability between surgeons is a potential contributing factor to existing controversy over nonoperative versus operative treatment for Type II supracondylar fractures. The purpose of this study was to investigate levels of agreement in classification of extension-type supracondylar humerus fractures using the Gartland classification system. A retrospective chart review was conducted on patients aged 2–12 years who had sustained an extension-type supracondylar fracture and received either operative or nonoperative treatment at a tertiary children's hospital. De-identified baseline anteroposterior (AP) and lateral plain elbow radiographs were provided along with a brief summary of the modified Gartland classification system to surgeons across Canada, United States, Australia, United Kingdom and India. Each surgeon was blinded to patient treatment and asked to classify the fractures as Type I, IIA, IIB or III according to the classification system provided. A total of 21 paediatric orthopaedic surgeons completed one round of classification, of these, 15 completed a second round using the same radiographs in a reshuffled order. Kappa values using pre-determined weighted kappa coefficients were calculated to assess interobserver and intraobserver levels of agreement. In total, 60 sets of baseline elbow radiographs were provided to survey respondents. Interobserver agreement for classification based on the Gartland criteria between surgeons was a mean of 0.68, 95% CI [0.67, 0.69] (0.61–0.80 considered substantial agreement). Intraobserver agreement was a mean of 0.80 [0.75, 0.84]. (0.61–0.80 substantial agreement, 0.81–1 almost perfect agreement). Radiographic classification of extension-type supracondylar humerus fractures at baseline demonstrated substantial agreement both between and within surgeon raters. Levels of agreement are substantial enough to suggest that classification variability is not a major contributing factor to variability in treatment between surgeons for Type II supracondylar fractures. Further research is needed to compare patient outcomes between nonoperative and operative treatment for these fractures, so as to establish consensus and a standardized treatment protocol for optimal patient care across centres

This study aims to implement and assess the inter and intra-reliability of a modernised radiolucency assessment system; the Radiolucency In cemented Stemmed Knee (RISK) arthroplasty classification. Furthermore, we assessed the distribution of regions affected by radiolucency in patients undergoing stemmed cemented knee arthroplasty. Stemmed knee arthroplasty cases over 7-year period at a single institution were retrospectively identified and reviewed. The RISK classification system identifies five zones in the femur and five zones in the tibia in both the anteroposterior (AP) and lateral planes. Post-operative and follow-up radiographs were scored for radiolucency by four blinded reviewers at two distinct time points four weeks apart. Reliability was assessed using the kappa statistic. A heat map was generated to demonstrate the reported regions of radiolucency. 29 cases (63 radiographs) of stemmed knee arthroplasty were examined radiographically using the RISK system. Intra-reliability (0.83) and Inter-reliability (0.80) scores were both consistent with a strong level of agreement using the kappa scoring system. Radiolucency was more commonly associated with the tibial component (76.6%) compared to the femoral component (23.3%), and the tibial anterior-posterior (AP) region 1 (medial plateau) was the most affected (14.9%). The RISK classification system is a reliable assessment tool for evaluating radiolucency around stemmed knee arthroplasty using defined zones on both AP and lateral radiographs. Zones of radiolucency identified in this study may be relevant to implant survival and corresponded well with zones of fixation, which may help inform future research

Objectives. Open fracture classification systems are limited in their use. Our objective was to classify open tibia and femur fractures using the OTS classification system in a region with high incidence of gunshot fractures. One hundred and thirty-seven patients with diaphyseal tibia and femur open fractures were identified from a prospectively collected cohort of patients. This database contained all cases (closed and open fractures) of tibial and femoral intramedullary nailed patients older than 18 years old during the period of September 2017 to May 2021. Exclusion criteria included closed fractures, non-viable limbs, open fractures > 48 hours to first surgical debridement and patients unable to follow up over a period of 12 months (a total of 24). Open fractures captured and classified in the HOST study using the Gustilo-Anderson classification, were reviewed and reclassified using the OTS open fracture classification system, analysing gunshot fractures in particular. Ninety percent were males with a mean age of 34. Most common mechanism was civilian gunshot wounds (gsw) in 54.7% of cases. In 52.6% of cases soft tissue management was healing via secondary intention, these not encompassed in the classification. Fracture classification was OTS Simple in 23.4%, Complex B in 24.1% and 52.6% of cases unclassified. The OTS classification system was not comprehensive in the classification of open tibia and femur fractures in a setting of high incidence of gunshot fractures. An amendment has been proposed to alter acute management to appropriate wound care and to subcategorise Simple into A and B subdivisions; no soft tissue intervention and primary closure respectively. This will render the OTS classification system more inclusive to all open fractures of all causes with the potential to better guide patient care and clinical research

Aims. Although knee osteoarthritis (OA) is diagnosed and monitored radiologically, actual full-thickness cartilage loss (FTCL) has rarely been correlated with radiological classification. This study aims to analyze which classification system correlates best with FTCL and to assess their reliability. Methods. A prospective study of 300 consecutive patients undergoing unilateral total knee arthroplasty (TKA) for OA (mean age 69 years (44 to 91; standard deviation (SD) 9.5), 178 (59%) female). Two blinded examiners independently graded preoperative radiographs using five common systems: Kellgren-Lawrence (KL); International Knee Documentation Committee (IKDC); Fairbank; Brandt; and Ahlbäck. Interobserver agreement was assessed using the intraclass correlation coefficient (ICC). Intraoperatively, anterior cruciate ligament (ACL) status and the presence of FTCL in 16 regions of interest were recorded. Radiological classification and FTCL were correlated using the Spearman correlation coefficient. Results. Knees had a mean of 6.8 regions of FTCL (SD 3.1), most common medially. The commonest patterns of FTCL were medial ± patellofemoral (143/300, 48%) and tricompartmental (89/300, 30%). ACL status was associated with pattern of FTCL (p = 0.023). All radiological classification systems demonstrated moderate ICC, but this was highest for the IKDC: whole knee 0.68 (95% confidence interval (CI) 0.60 to 0.74); medial compartment 0.84 (95% CI 0.80 to 0.87); and lateral compartment 0.79 (95% CI 0.73 to 0.83). Correlation with actual FTCL was strongest for Ahlbäck (Spearman rho 0.27 to 0.39) and KL (0.30 to 0.33) systems, although all systems demonstrated medium correlation. The Ahlbäck score was the most discriminating in severe knee OA. Osteophyte presence in the medial compartment had high positive predictive value (PPV) for FTCL, but not in the lateral compartment. Conclusion. The Ahlbäck and KL systems had the highest correlation with confirmed cartilage loss at TKA. However, the IKDC system displayed the best interobserver reliability, with favourable correlation with FTCL in medial and lateral compartments, although it was less discriminating in more severe disease. Cite this article: Bone Joint J 2020;102-B(3):301–309

Introduction. In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions. Methods. In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534-539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 - cleavage lesion; Grade 3 - delamination and Grade 4 –exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa. For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics. Results. We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96). In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions seen at hip arthroscopy

Aim. The B.A.C.H. system is a new classification for long bone osteomyelitis. It uses the four key inter-disciplinary components of osteomyelitis, namely, bone involvement, anti-microbial options, soft tissue status and host status. This study aims to assess the inter-user reliability of using the B.A.C.H. classification system. Method. We identified 20 patients who had a diagnosis of long bone osteomyelitis using a previously validated composite protocol. For each patient, osteomyelitis history, past-medical history, clinical imaging (including radiology report), photographs of the affected limb and microbiology were presented to clinical observers on an online form. Thirty observers, varying in clinical experience (training grades and consultants, with a variety of exposure to osteomyelitis) and specialty (orthopaedic surgery, infectious diseases and plastic surgery) were asked to rate the twenty cases of osteomyelitis. Before rating, an explanation of how to use the classification system was given to the observers, in a structured ‘user key’. The responses were assessed by accuracy against a reference value and Fleiss' kappa value (Fκ). Results. The 30 users individually classified all 20 cases. The observers comprised 14 orthopaedic surgeons, 13 physicians (either microbiology, infectious diseases or anesthetists) and 3 plastic surgeons. The users had a variety of exposure to osteomyelitis ranging from less than one case per month to greater than one case per week. The accuracy across all variables was 86.2% (95% CI 83.9% – 88.6%, SD 6.2%), with the ‘C’ variable scoring the highest at 92.5% (95% CI 88.5% – 95.6%, SD 8.2%) and the ‘B’ variable scoring the lowest at 77.0% (95% CI 71.2% – 82.8%, SD 15.5%). The variable with the highest agreement between users was the anti-microbial options with a Fκ of 0.815 (95% CI 0.811 – 0.819) which correlated to an ‘almost perfect agreement’. Despite this, the classification of the more complex isolates proved problematic. The most variability was seen in the bone involvement variable with an Fκ of 0.479 (95% CI 0.475 – 0.483) which correlated to a ‘fair agreement’. Conclusions. The B.A.C.H. classification system for long bone osteomyelitis demonstrated a substantial agreement between observers according to the Fκ value. This was supported by a high level of accuracy of classification within each of the variables. The bone involvement category had a moderate agreement amongst users. This could be due to the nature of the 2-D presentation of cases within the online form. The Fκ was not influenced by clinical experience or clinical specialty, suggesting that B.A.C.H. is applicable by all levels. Further work is required to assess and optimise the descriptions of the bone involvement and anti-microbial options variables

Introduction: In recent years, there has been a significant advancement in our understanding of femoro-acetabular impingement and associated labral and chondral pathology. Surgeons worldwide have demonstrated the successful treatment of these lesions via arthroscopic and open techniques. The aim of this study is to validate a simple and reproducible classification system for acetabular chondral lesions. Methods: In our classification system, the acetabulum is first divided into 6 zones as described by Ilizalithurri VM et al [Arthroscopy 24(5) 534–539]. The cartilage is then graded as 0 to 4 as follows: Grade 0 – normal articular cartilage lesions; Grade 1 softening or wave sign; Grade 2 – cleavage lesion; Grade 3 – delamination and Grade 4 -exposed bone. The site of the lesion is further typed as A, B or C based on whether the lesion is 1/3 distance from acetabular rim to cotyloid fossa, 1/3 to 2/3 distance from acetabular rim to cotyloid fossa and > 2/3 distance from acetabular rim to cotyloid fossa. For validating the classification system, six surgeons reviewed 14 hip arthroscopy video clips. All surgeons were provided with written explanation of our classification system. Each surgeon then individually graded the cartilage lesion. A single observer then compared results for observer variability using kappa statistics. Results: We observed a high inter-observer reliability of the classification system with a kappa coefficient of 0.89 (range 0.78 to 0.91) and high intra-observer reliability with a kappa coefficient of 0.91 (range 0.89 to 0.96). Discussion: In conclusion we have developed a simple reproducible classification system for acetabular cartilage lesions

Introduction. Undersizing of an uncemented femoral stem is a post-operative description of a radiograph with unclear clinical importance. It may not always translate into a suboptimal clinical outcome. Aim. To describe a novel classification system of undersizing in a fully hydroxyapatite coated femoral implant, assess if it could be reliably reported between observers, and describe a simple way to assess the degree of undersizing on an AP radiograph. Methods. A retrospective review of 1000 consecutive total hip arthroplasties was conducted. Two investigators reviewed post-operative radiographs independently for stem undersizing. The data was tested for inter and intra-observer agreement using the Kappa method. Results. Undersizing was classified as:. Varus - Stem in contact proximally with medial calcar, and distally with lateral cortex. Valgus - Stem in contact proximally with lateral cortex, and distally with medial cortex. Uniform - Continuous margin around the stem of at least one-half tip width of the stem throughout. Champagne flute - Distal stem fills the narrow diaphysis with insufficient bony contact at the wide metaphysis. If varus or valgus undersizing was present we described the formation of two triangles of excess cancellous space around the implant, each having overlapping apices signifying undersizing by at least two sizes. 32% of the stems were undersized with Kappa demonstrating very good (89%) to good (86%) inter and intra observer agreement respectively. 50% of undersized stems were uniformly undersized, 36% were varus, 6% valgus, and 8% were in a champagne fluted shaped femur. A higher percentage of the lateralised (KLA) stems were undersized compared to other neck configurations (40%). 54% of these were varus undersized and this increased the offset up to 2cm. Conclusion. We describe a classification system for undersizing in hip arthroplasty. KLA stems have an increased tendency to be undersized in varus, thereby increasing the overall offset

Introduction. The use of short stems has been growing in THA for the past five years. As a result, a large number of short stem designs are available in the market place. However, fixation points differ for many of the designs resulting in different radiographic modeling creating confusion when trying to collate to clinical findings. We have created a classification system in an attempted to provide clarity in analyzing radiographic and clinical findings. Method. Femoral implants described as “short stems” were evaluated. The range of lengths for stem type and the method of achieving initial implant stability was determined. The optimal radiographic position of each of these implants and type of bone remodeling associated with this placement was evaluated. Stems were defined as “short” if the tip reached or was proximal to the metaphyseal-diaphyseal junction. This location on the proximal femur was defined as the place at which the medial-lateral metaphyseal flare became parallel. Stems were then classified as: 1.) Metaphyseal Stabilized; 2.) Neck Stabilized; 3.) Head Stabilized. An analysis of radiographic with a minimum of one year follow up were reviewed and posted as to the classification system. Results. The range of stem lengths for stem type and the method of achieving initial implant stability was determined. A classification of short-stemmed components has been defined, making it possible to evaluate and differentiate both radiographic and clinical findings. Not all so-called short stems exhibit the same radiographic and clinical findings. It also became apparent that the different stabilization points require specific surgical techniques to ensure reproducible good results. Findings for neck stabilized present with different findings as compared to metaphyseal stabilized and head stabilized. We are optimistic that this classification system will help to compare short-stemmed implants and how they performed to the more traditional convention cementless stems

Background. Total hip arthroplasty (THA) in patients with congenital dysplasia of the hip (CDH) is complex and challenging. The Crowe and Hartofilakidis classification systems are the most commonly used. However, neither encompasses the whole spectrum of disease and deformity and therefore does not guide modern surgical options. We present a new classification system which aims to guide surgical strategy by focusing on the three main areas of disease and deformity: Cup defect; De-rotation of femoral neck ante-version; Height of femoral subluxation. Each component is graded from 1–3 based on the severity of deformity and the potential surgical strategy required (with 3 being the most severe). A total numerical score will reflect the overall degree of difficulty which may be used when assessing surgical outcomes. The aim of this study is to assess the reliability of this new adult CDH classification system in the setting of THA. Study design and Methods. A sample size calculation showed 28 evaluations were required to reach a power of 85% (based on a kappa value of 0.4). The anterior-posterior pelvis and lateral hip radiographs of 30 hips, in 26 patients were evaluated by three Consultant Orthopaedic Surgeons using the classification detailed in table 1. A second evaluation, with the case order randomised, was performed after a minimum period of 1month. Randolph's free multi-rater Kappa co-efficient was used to assess for inter and intra- observer reliability and 95% confidence intervals were calculated. Results. The results of the Inter and intra–observer reliability for each classification component and for each rater respectively are shown in table 2 and 3. Conclusions. In comparison with other studies our reliability results were poorer when compared to the Hartofilakidis and Crowe classification systems. It was reported by the participants that our system enabled a more logical breakdown of the component deformities to address when performing THA in these hips. As with the Paprosky system for revision hip arthroplasty, this X-ray classification is intended as a practical pre-op guide to planning for all eventualities. Limitations due to level of observer experience and finer intra-operative judgements may alter the final result, but the essence is to understand the anatomical pitfalls enabling appropriate surgical planning and a total score against which to judge outcomes. For any figures or tables, please contact the authors directly

Aims. Joint registries classify all further arthroplasty procedures to a knee with an existing partial arthroplasty as revision surgery, regardless of the actual procedure performed. Relatively minor procedures, including bearing exchanges, are classified in the same way as major operations requiring augments and stems. A new classification system is proposed to acknowledge and describe the detail of these procedures, which has implications for risk, recovery, and health economics. Methods. Classification categories were proposed by a surgical consensus group, then ranked by patients, according to perceived invasiveness and implications for recovery. In round one, 26 revision cases were classified by the consensus group. Results were tested for inter-rater reliability. In round two, four additional cases were added for clarity. Round three repeated the survey one month later, subject to inter- and intrarater reliability testing. In round four, five additional expert partial knee arthroplasty surgeons were asked to classify the 30 cases according to the proposed revision partial knee classification (RPKC) system. Results. Four classes were proposed: PR1, where no bone-implant interfaces are affected; PR2, where surgery does not include conversion to total knee arthroplasty, for example, a second partial arthroplasty to a native compartment; PR3, when a standard primary total knee prosthesis is used; and PR4 when revision components are necessary. Round one resulted in 92% inter-rater agreement (Kendall’s W 0.97; p < 0.005), rising to 93% in round two (Kendall’s W 0.98; p < 0.001). Round three demonstrated 97% agreement (Kendall’s W 0.98; p < 0.001), with high intra-rater reliability (interclass correlation coefficient (ICC) 0.99; 95% confidence interval 0.98 to 0.99). Round four resulted in 80% agreement (Kendall’s W 0.92; p < 0.001). Conclusion. The RPKC system accounts for all procedures which may be appropriate following partial knee arthroplasty. It has been shown to be reliable, repeatable and pragmatic. The implications for patient care and health economics are discussed. Cite this article: Bone Jt Open 2021;2(8):638–645

The adult congenital hip dislocations and dysplasias have been previously classified by Eftekhar, Crowe et al., Hartofilakidis et al., Kerboul et al. and Mendes et al. The most conventient and widely used one is the Hartofilakidis and Crowe classification. Three different types of congenital hip disease in adults have been distinguished by Hartofilakidis and et al. based upon the position of the femoral head relative to the acetabulum: dysplasia; low dislocation; and high dislocation. All these classification systems are only radiological and does not highlight the operative technique in detail and the complications that we can observe perioperatively. Our classification system is also a radiological classification system but more useful for predicting the difficulty of the operative procedure and selecting the right operative method. In our classification system; at type I; dysplasia and less than 25% subluxations, we divided type I in to three subgroups, at type Ia, only dysplastic acetabulums, at type Ib, with elephant’s trunk type osteophyte formation and at type Ic, curtain type osteophytic formations, we included dysplasia and less than 25% subluxations in the same group because of operative technique similarities. At type 2; subluxations between 25% and 75%, we divided type II in two subgroups according to the angle between the inner margin of the teardrop and superior border of the acetabulum, at type IIa, the angle is less than 60°, at type IIb, the angle is greater than 60°, it’s important to show femoral allogreft usage requirement, at type 3; subluxations greater than 75%, at this type there will be no need of femoral allogreft usage but extra-small reamer usage for forming a suitable acetabular bed. At type 4; luxations greater than 100%, we also divided type IV in to two subgroups accordind to the distance between superior margin of true acetabulum and trochanter major line, at type IVa, < 2.5 cm, at type IVb, > 2.5 cm. It’s also important to make the decission of shortening. To form this classification three observers with different levels of training independently classified 412 dysplastic hips (operated between1995 and 2005) on 380 standard anteriorposterior pelvis radiographs, retrospectively according to the criteria defined by us. To assess intraobserver reliability, the measurement was repeated 3 months later. Statistical analysis was performed by calculating the weighted kappa correlation coefficient. System showed good inter- and intraob-server reliability for use in daily practice. Eventually, we determined a significant correlation between the aplied surgical procedures and classification. As a conclusion, we believe that our classification system of osteoarthritis secondary to developmental dysplasia of the hip in adult patients guides the surgical procedure more effectively than the other classification systems

Background/Purpose: One goal of LBP assessment is to direct clinicians to specific sub-groups that benefit from particular treatment approaches. The purpose of this study was to compare outcomes between patients assessed and treated based on a diagnostic system of LBP classification and those managed without a classification system. Methods/Results: This was a prospective double-cohort study of mechanical LBP cases (n=2110) who started a rehabilitation program at 15 clinics across Canada between February 06 and August 07. A group of patients attending 7 clinics specifically trained in the use of a LBP classification system using patterns of pain, not anatomic site or pathological process (n=1356) were compared with patients from 8 clinics using a generic, non-classification approach (n=754). Patients are categorized into one of five classifications, each dictating a separate treatment approach. The mean age of the cohort was 44.7 years (SD=13.3, range=18–89) with 55.1% males. The mean lagtime from injury to treatment was 110.7 days (median=32 days). Treatment based on this classification system resulted in more pain reduction (p< 0.001), higher functional improvement (p< 0.001), less medication use (p< 0.001) and fewer treatment days (p< 0.001), compared to a generic approach. Conclusion: Outcome differences between groups suggest that LBP is heterogeneous, and recognizable by clinical patterns of patient characteristics. The results support the effectiveness of a classification system that matches treatment to patient presentation and pattern of pain. Showing that one cohort had better outcomes than another as a result of classifying back pain is formidable test of validity

There have been considerable recent advances in the understanding and management of femoroacetabular impingement and associated labral and chondral pathology. We have developed a classification system for acetabular chondral lesions. In our system, we use the six acetabular zones previously described by Ilizaliturri et al. The cartilage is then graded on a scale of 0 to 4 as follows: grade 0, normal articular cartilage lesions; grade 1, softening or wave sign; grade 2, cleavage lesion; grade 3, delamination; and grade 4, exposed bone. The site of the lesion is further classed as A, B or C based on whether the lesion is less than one-third of the distance from the acetabular rim to the cotyloid fossa, one-third to two-thirds of the same distance and greater than two-thirds of the distance, respectively. In order to validate the classification system, six surgeons graded ten video recordings of hip arthroscopy. Our findings showed a high intra-observer reliability of the classification system with an intraclass correlation coefficient of 0.81 and a high interobserver reliability with an intraclass correlation coefficient of 0.88. We have developed a simple reproducible classification system for lesions of the acetabular cartilage, which it is hoped will allow standardised documentation to be made of damage to the articular cartilage, particularly that associated with femoroacetabular impingement