Unexplained pain after total knee arthroplasty

Although total knee arthroplasty (TKA) improves function and reduces pain for the large majority of the patients, a few continue to have pain and require investigation. The causes of dysfunction and pain after total knee arthroplasty can be described as intrinsic (intra-articular) or extrinsic (extra-articular) sources of pain. For the majority of the cases, following a complete evaluation protocol, the cause of pain can be identified and a specific treatment can be applied, however occasionally there remains a group of patients with unexplained pain whose management is difficult. It was our hypothesis that revising a TKA without pre-operative diagnosis of the failure is not worth. Therefore, the aimed of this review was to: 1) analyse the results of revision TKA for unexplained pain, and 2) described the potential solutions for an alternative conservative management of the painful TKA

Isolated patellofemoral osteoarthritis: A systematic review of treatment options using the GRADE approach

Background and purpose The optimal treatment for isolated patellofemoral osteoarthritis is unclear at present. We systematically reviewed the highest level of available evidence on the nonoperative and operative treatment of isolated patellofemoral osteoarthritis to develop an evidenced-based discussion of treatment options

Metal backed versus all-polyethylene unicompartmental knee arthroplasty: the effect of implant thickness on proximal tibial strain in an experimentally validated finite element model

Objectives Up to 40% of unicompartmental knee arthroplasty (UKA) revisions are performed for unexplained pain which may be caused by elevated proximal tibial bone strain. This study investigates the effect of tibial component metal backing and polyethylene thickness on bone strain in a cemented fixed-bearing medial UKA using a finite element model (FEM) validated experimentally by digital image correlation (DIC) and acoustic emission (AE). Materials and Methods A total of ten composite tibias implanted with all-polyethylene (AP) and metal-backed (MB) tibial components were loaded to 2500 N. Cortical strain was measured using DIC and cancellous microdamage using AE. FEMs were created and validated and polyethylene thickness varied from 6 mm to 10 mm. The volume of cancellous bone exposed to 3000 µε and > 7000 µε maximum principal (tensile) microstrain was computed. Results Experimental AE data and the FEM volume of cancellous bone with compressive strain < -3000 µε correlated strongly: R = 0.947, R2 = 0.847, percentage error 12.5% (p < 0.001). DIC and FEM data correlated: R = 0.838, R2 = 0.702, percentage error 4.5% (p < 0.001). FEM strain patterns included MB lateral edge concentrations; AP concentrations at keel, peg and at the region of load application. Cancellous strains were higher in AP implants at all loads: 2.2- (10 mm) to 3.2-times (6 mm) the volume of cancellous bone compressively strained < -7000 µε. Conclusion AP tibial components display greater volumes of pathologically overstrained cancellous bone than MB implants of the same geometry. Increasing AP thickness does not overcome these pathological forces and comes at the cost of greater bone resection

What should an ideal spinal injury classification system consist of? A methodological review and conceptual proposal for future classifications

Since Böhler published the first categorization of spinal injuries based on plain radiographic examinations in 1929, numerous classifications have been proposed. Despite all these efforts, however, only a few have been tested for reliability and validity. This methodological, conceptual review summarizes that a spinal injury classification system should be clinically relevant, reliable and accurate. The clinical relevance of a classification is directly related to its content validity. The ideal content of a spinal injury classification should only include injury characteristics of the vertebral column, is primarily based on the increasingly routinely performed CT imaging, and is clearly distinctive from severity scales and treatment algorithms. Clearly defined observation and conversion criteria are crucial determinants of classification systems’ reliability and accuracy. Ideally, two principle spinal injury characteristics should be easy to discern on diagnostic images: the specific location and morphology of the injured spinal structure. Given the current evidence and diagnostic imaging technology, descriptions of the mechanisms of injury and ligamentous injury should not be included in a spinal injury classification. The presence of concomitant neurologic deficits can be integrated in a spinal injury severity scale, which in turn can be considered in a spinal injury treatment algorithm. Ideally, a validation pathway of a spinal injury classification system should be completed prior to its clinical and scientific implementation. This review provides a methodological concept which might be considered prior to the synthesis of new or modified spinal injury classifications

Do double-row suture-locking anchors impact the biomechanical outcomes of rotator cuff surgery? A biomechanical study

International audienceIntroduction: Several surgical techniques for arthroscopic repair of the rotator cuff have been described in the literature. The aim of this study was to determine whether the suture thread locking method in double-row anchors influences their biomechanical properties. We compared the pullout strength of two anchors with different locking mechanisms.Introduction: Several surgical techniques for arthroscopic repair of the rotator cuff have been described in the literature. The aim of this study was to determine whether the suture thread locking method in double-row anchors influences their biomechanical properties. We compared the pullout strength of two anchors with different locking mechanisms.Methods: We performed 30 pullout tests at 135° using two different double-row anchors, an interference fit lock (5.5 mm SwiveLock) and a combination lock (5.5 mm MultiFix S). One anchor of each type was implanted on the tuberosity of a bovine humeral bone.Results: Mean pullout strength was 239.29 ± 83.73 N for the SwiveLock anchors and 253.82 ± 87.65 N for the MultiFIX S anchors, mean displacement (in millimeters) was 28 ± 9 and 30 ± 12, respectively which were not statistically significantly different.Conclusion: The addition of an internal lock in the double-row suture-locking anchor did not improve the biomechanical properties in a pullout test of 135