With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting. MEDLINE, EMBASE via OVID, CINAHL, and EBSCO were searched from inception to January 2022. Any study addressing surgical treatment of primary patellofemoral joint OA using second generation PFA and TKA in patients aged above 18 years with follow-up data of 30 days were included. Studies relating to OA secondary to trauma were excluded. ROB-2 and ROBINS-I bias tools were used.Aims
Methods
MRI has been suggested as an objective method of assessing anterior crucate ligament (ACL) graft “ligamentization” after reconstruction. It has been proposed that the MRI appearances could be used as an indicator of graft maturity and used as part of a return-to-sport assessment. The aim of this study was to evaluate the correlation between MRI graft signal and postoperative functional scores, anterior knee laxity, and patient age at operation. A consecutive cohort of 149 patients who had undergone semitendinosus autograft ACL reconstruction, using femoral and tibial adjustable loop fixations, were evaluated retrospectively postoperatively at two years. All underwent MRI analysis of the ACL graft, performed using signal-to-noise quotient (SNQ) and the Howell score. Functional outcome scores (Lysholm, Tegner, International Knee Documentation Committee (IKDC) subjective, and IKDC objective) were obtained and all patients underwent instrumented side-to-side anterior laxity differential laxity testing.Aims
Methods
The aims of this study were to evaluate wear on the surface of cobalt-chromium (CoCr) femoral components used in total knee arthroplasty (TKA) and compare the wear of these components with that of ceramic femoral components. Optical profilometry was used to evaluate surface roughness and to examine the features created by the wear process in a knee wear simulator. We developed a method of measuring surface changes on five CoCr femoral components and quantifying the loss of material from the articular surface during the wear process. We also examined the articular surface of three ceramic femoral components from a previous test for evidence of surface damage, and compared it with that of CoCr components.Aims
Methods
To establish our early clinical results of a new total knee arthroplasty (TKA) tibial component introduced in 2013 and compare it to other designs in use at our hospital during the same period. This is a retrospective study of 166 (154 patients) consecutive cemented, fixed bearing, posterior-stabilized (PS) TKAs (ATTUNE) at one hospital performed by five surgeons. These were compared with a reference cohort of 511 knees (470 patients) of other designs (seven manufacturers) performed at the same hospital by the same surgeons. There were no significant differences in age, sex, BMI, or follow-up times between the two cohorts. The primary outcome was revision performed or pending.Aims
Methods
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. 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.Objectives
Materials and Methods
A national, multi-centre study was designed in
which a questionnaire quantifying the degree of patient satisfaction
and residual symptoms in patients following total knee replacement
(TKR) was administered by an independent, blinded third party survey
centre. A total of 90% of patients reported satisfaction with the
overall functioning of their knee, but 66% felt their knee to be
‘normal’, with the reported incidence of residual symptoms and functional
problems ranging from 33% to 54%. Female patients and patients from
low-income households had increased odds of reporting dissatisfaction.
Neither the use of contemporary implant designs (gender-specific,
high-flex, rotating platform) or custom cutting guides (CCG) with
a neutral mechanical axis target improved patient-perceived outcomes.
However, use of a CCG to perform a so-called kinematically aligned
TKR showed a trend towards more patients reporting their knee to
feel ‘normal’ when compared with a so called mechanically aligned
TKR This data shows a degree of dissatisfaction and residual symptoms
following TKR, and that several recent modifications in implant
design and surgical technique have not improved the current situation. Cite this article:
Orthopaedic surgeons use stems in revision knee surgery to obtain
stability when metaphyseal bone is missing. No consensus exists
regarding stem size or method of fixation. This A custom test rig using differential variable reluctance transducers
(DVRTs) was developed to record all translational and rotational
motions at the bone–implant interface. Composite femurs were used.
These were secured to permit variation in flexion angle from 0°
to 90°. Cyclic loads were applied through a tibial component based
on three peaks corresponding to 0°, 10° and 20° flexion from a normal
walking cycle. Three different femoral components were investigated
in this study for cementless and cemented interface conditions.Objectives
Methods
Between April 2004 and July 2007, we performed 241 primary total knee replacements in 204 patients using the e.motion posterior cruciate-retaining, multidirectional mobile-bearing prosthesis. Of these, 100 were carried out using an image-free navigation system, and the remaining 141 with the conventional technique. We conducted a retrospective study from the prospectively collected data of these patients to assess the early results of this new mobile-bearing design. At a mean follow-up of 49 months (32 to 71), 18 knees (7.5%) had mechanical complications of which 13 required revision. Three of these had a peri-prosthetic fracture, and were removed from the study. The indication for revision in the remaining ten was loosening of the femoral component in two, tibiofemoral dislocation in three, disassociation of the polyethylene liner in four, and a broken polyethyene liner in one. There were eight further mechanically unstable knees which presented with recurrent disassociation of the polyethylene liner. There was no significant difference in the incidence of mechanical instability between the navigation-assisted procedures (8 of 99, 8.1%) and the conventionally implanted knees (10 of 139, 7.2%). In our view, the relatively high rate of mechanical complications and revision within 30 months precludes the further use of new design of knee replacement.
Animal studies have shown that implanted anterior cruciate ligament (ACL) grafts initially undergo a process of revascularisation prior to remodelling, ultimately increasing mechanical strength. We investigated whether minimal debridement of the intercondylar notch and the residual stump of the ruptured ACL leads to earlier revascularisation in ACL reconstruction in humans. We undertook a randomised controlled clinical trial in which 49 patients underwent ACL reconstruction using autologous four-strand hamstring tendon grafts. Randomised by the use of sealed envelopes, 25 patients had a conventional clearance of the intercondylar notch and 24 had a minimal debridement method. Three patients were excluded from the study. All patients underwent MR scanning postoperatively at 2, 6 and 12 months, together with clinical assessment using a KT-1000 arthrometer and International Knee Documentation Committee (IKDC) evaluation. All observations were made by investigators blinded to the surgical technique. Signal intensity was measured in 4 mm diameter regions of interest along the ACL graft and the mid-substance of the posterior cruciate ligament. Our results indicate that minimal debridement leads to earlier revascularisation within the mid-substance of the ACL graft at two months (paired
Clinical experience of impaction bone grafting for revision knee arthroplasty is limited, with initial stability of the tibial tray emerging as a major concern. The length of the stem and its diameter have been altered to improve stability. Our aim was to investigate the effect of the type of stem, support of the rim and graft impaction on early stability of the tray. We developed a system for impaction grafting of trays which we used with morsellised bone in artificial tibiae. Trays with short, long thick or long thin stems were implanted, with or without support of the rim. They were cyclically loaded while measuring relative movement. Long-stemmed trays migrated 4.5 times less than short-stemmed trays, regardless of diameter. Those with support migrated 2.8 times less than those without. The migration of short-stemmed trays correlated inversely with the density of the impacted groups. That of impaction-grafted tibial trays was in the range reported for uncemented primary trays. Movements of short-stemmed trays without cortical support were largest and sensitive to the degree of compaction of the graft. If support of the rim was sufficient or a long stem was used, impacted morsellised bone graft achieved adequate initial stability.
