The aim of this retrospective study was to assess the incidence of early periprosthetic femoral fracture (PFF) associated with Charnley-Kerboull (CK) femoral components cemented according to the ‘French paradox’ principles through the Hueter anterior approach (HAA) in patients older than 70 years. From a prospectively collected database, all short CK femoral components implanted consecutively from January 2018 to May 2022 through the HAA in patients older than 70 years were included. Exclusion criteria were age below 70 years, use of cementless femoral component, and approaches other than the HAA. A total of 416 short CK prostheses used by 25 surgeons with various levels of experience were included. All patients had a minimum of one-year follow-up, with a mean of 2.6 years (SD 1.1). The mean age was 77.4 years (70 to 95) and the mean BMI was 25.3 kg/m2 (18.4 to 43). Femoral anatomy was classified according to Dorr. The measured parameters included canal flare index, morphological cortical index, canal-calcar ratio, ilium-ischial ratio, and anterior superior iliac spine to greater trochanter (GT) distance.Aims
Methods
The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.Aims
Methods
Orthopaedic surgeons are currently faced with an overwhelming number of choices surrounding total knee arthroplasty (TKA), not only with the latest technologies and prostheses, but also fundamental decisions on alignment philosophies. From ‘mechanical’ to ‘adjusted mechanical’ to ‘restricted kinematic’ to ‘unrestricted kinematic’ — and how constitutional alignment relates to these — there is potential for ambiguity when thinking about and discussing such concepts. This annotation summarizes the various alignment strategies currently employed in TKA. It provides a clear framework and consistent language that will assist surgeons to compare confidently and contrast the concepts, while also discussing the latest opinions about alignment in TKA. Finally, it provides suggestions for applying consistent nomenclature to future research, especially as we explore the implications of 3D alignment patterns on patient outcomes. Cite this article:
Aims. The aim of this study was to compare any differences in the primary outcome (biphasic flexion knee moment during gait) of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) at one year post-surgery. Methods. A total of 76 patients (34 bi-UKA and 42 TKA patients) were analyzed in a prospective, single-centre, randomized controlled trial. Flat ground shod gait analysis was performed preoperatively and one year postoperatively. Knee flexion moment was calculated from motion capture markers and force plates. The same setup determined proprioception outcomes during a joint position sense test and one-leg standing. Surgery allocation, surgeon, and secondary outcomes were analyzed for prediction of the primary outcome from a binary regression model. Results. Both interventions were shown to be effective treatment options, with no significant differences shown between interventions for the primary outcome of this study (18/35 (51.4%) biphasic TKA patients vs 20/31 (64.5%) biphasic bi-UKA patients; p = 0.558). All outcomes were compared to an age-matched, healthy cohort that outperformed both groups, indicating residual deficits exists following surgery. Logistic regression analysis of primary outcome with secondary outcomes indicated that the most significant predictor of postoperative biphasic knee moments was preoperative knee moment profile and trochlear degradation (Outerbridge) (R. 2. = 0.381; p = 0.002, p = 0.046). A separate regression of alignment against primary outcome indicated significant bi-UKA femoral and tibial
Limb alignment in total knee arthroplasty (TKA) influences periarticular soft-tissue tension, biomechanics through knee flexion, and implant survival. Despite this, there is no uniform consensus on the optimal alignment technique for TKA. Neutral mechanical alignment facilitates knee flexion and symmetrical component wear but forces the limb into an unnatural position that alters native knee kinematics through the arc of knee flexion. Kinematic alignment aims to restore native limb alignment, but the safe ranges with this technique remain uncertain and the effects of this alignment technique on component survivorship remain unknown. Anatomical alignment aims to restore predisease limb alignment and knee geometry, but existing studies using this technique are based on cadaveric specimens or clinical trials with limited follow-up times. Functional alignment aims to restore the native plane and obliquity of the joint by manipulating implant positioning while limiting soft tissue releases, but the results of high-quality studies with long-term outcomes are still awaited. The drawbacks of existing studies on alignment include the use of surgical techniques with limited accuracy and reproducibility of achieving the planned alignment, poor correlation of intraoperative data to long-term functional outcomes and implant survivorship, and a paucity of studies on the safe ranges of limb alignment. Further studies on alignment in TKA should use surgical adjuncts (e.g. robotic technology) to help execute the planned alignment with improved accuracy, include intraoperative assessments of knee biomechanics and periarticular soft-tissue tension, and correlate alignment to long-term functional outcomes and survivorship.
Aims. The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery. Methods. An analysis of 38 patients who underwent TKA and 32 who underwent bi-UKA was performed as a secondary study from a prospective, single-centre, randomized controlled trial. CT imaging was used to measure coronal, sagittal, and
The use of shorter humeral stems in reverse shoulder arthroplasty has been reported as safe and effective. Shorter stems are purported to be bone preserving, easy to revise, and have reduced surgical time. However, a frequent radiographic finding with the use of uncemented short stems is stress shielding. Smaller stem diameters reduce stress shielding, however, carry the risk of varus or valgus malalignment in the metadiaphyseal region of the proximal humerus. The aim of this retrospective radiographic study was to measure the true post-operative neck-shaft (N-S) angle of a curved short stem with a recommended implantation angle of 145°. True anteroposterior radiographs of patients who received RTSA using an Ascend Flex short stem at three specialized shoulder centres (London, ON, Canada, Lyon, France, Munich, Germany) were reviewed. Radiographs that showed the uncemented stem and humeral tray in orthogonal view without rotation were included. Sixteen patients with proximal humeral fractures or revision surgeries were excluded. This yielded a cohort of 124 implant cases for analysis (122 patients, 42 male, 80 female) at a mean age of 74 years (range, 48 – 91 years). The indications for RTSA were rotator cuff deficient shoulders (cuff tear arthropathy, massive cuff tears, osteoarthritis with cuff insufficiency) in 78 patients (63%), primary osteoarthritis in 41 (33%), and rheumatoid arthritis in 5 (4%). The humeral component longitudinal axis was measured in degrees and defined as neutral if the value fell within ±5° of the humeral axis. Angle values >5° and < 5 ° were defined as valgus and varus, respectively. The filling-ratio of the implant within the humeral shaft was measured at the level of the metaphysis (FRmet) and diaphysis (FRdia). Measurements were conducted by two independent examiners (SA and TW). To test for conformity of observers, the intraclass correlation coefficient (ICC) was calculated. The inter- and intra-observer reliability was excellent (ICC = 0.965, 95% confidence interval [CI], 0.911– 0.986). The average difference between the humeral shaft axis and the humeral component longitudinal axis was 3.8° ± 2.8° (range, 0.2° – 13.2°) corresponding to a true mean N-S angle of 149° ± 3° in valgus. Stem axis was neutral in 70% (n=90) of implants. Of the 34 malaligned implants, 82% (n=28) were in valgus (mean N-S angle 153° ± 2°) and 18% (n=6) in varus position (mean N-S angle 139° ± 1°). The average FRmet and FRdiawere 0.68 ± 0.11 and 0.72 ± 0.11, respectively. No association was found between stem diameter and filling ratios (FRmet, FRdia) or cortical contact with the stem (r = 0.39). Operative technique and implant design affect the ultimate positioning of the implant in the proximal humerus. This study has shown, that in uncemented short stem implants, neutral
Postoperative range of movement (ROM) is an important measure of successful and satisfying total knee arthroplasty (TKA). Reduced postoperative ROM may be evident in up to 20% of all TKAs and negatively affects satisfaction. To improve ROM, manipulation under anaesthesia (MUA) may be performed. Historically, a limited ROM preoperatively was used as the key harbinger of the postoperative ROM. However, comorbidities may also be useful in predicting postoperative stiffness. The goal was to assess preoperative comorbidities in patients undergoing TKA relative to incidence of postoperative MUA. The hope is to forecast those who may be at increased risk and determine if MUA is an effective form of treatment. Prospectively collected data of TKAs performed at our institution’s two hospitals from August 2014 to August 2018 were evaluated for incidence of MUA. Comorbid conditions, risk factors, implant component design and fixation method (cemented vs cementless), and discharge disposition were analyzed. Overall, 3,556 TKAs met the inclusion criteria. Of those, 164 underwent MUA.Aims
Methods
Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved. Cite this article:
Introduction. Rotational or
Aims
Patients and Methods
Even though primary total knee arthroplasty involves resurfacing the joint with metal and plastic it is much more of a soft tissue operation than it is a bony procedure. The idea that altering the planned bony resection by a few degrees on either the tibial or femoral side of the joint might somehow eliminate the multifactorial pain complaints and reduced patient satisfaction seen in some 20% or more of cases in reported clinical series is clearly overly optimistic.
Each of the seven cuts required for a total knee arthroplasty has its own science, and can affect the outcome of surgery. Distal Femur. Sets the
Introduction. The use of stems in TKA revision surgery is well established. Stems off-load stress over a broad surface area of the diaphysis and help protect the metaphyseal interface areas from failure. Stems can provide an area of extra fixation. Uncemented Stems. Pros and Cons. Advantages. (1) Expeditious, (2) Compatible with intramedullary based revision instrumentation (3) Easy to remove if necessary (4) By filling diaphysis they help guarantee
Tibial plateau fractures are common injuries. Displaced fractures are treated with open reduction and internal fixation (ORIF). Goals of treatment include restoration of extremity
Fractures around total knee arthroplasties pose
a significant surgical challenge. Most can be managed with osteosynthesis
and salvage of the replacement. The techniques of fixation of these
fractures and revision surgery have evolved and so has the assessment
of outcome. This specialty update summarises the current evidence
for the classification, methods of fixation, revision surgery and
outcomes of the management of periprosthetic fractures associated
with total knee arthroplasty. Cite this article:
We wished to examine the effectiveness of tibial lengthening
using a two ring Ilizarov frame in skeletally immature patients.
This is a potentially biomechanically unstable construct which risks
the loss of axial control. We retrospectively reviewed a consecutive series of 24 boys and
26 girls, with a mean age of 8.6 years (4 to 14), who underwent
52 tibial lengthening procedures with a mean follow-up of 4.3 years
(4.0 to 16.9). Tibial alignment was measured before and after treatment
using joint orientation lines from the knee and a calculation of
the oblique plane axis.Aims
Patients and Methods
Introduction. Total Knee Replacement (TKR) alignment measured intra-operatively with Navigation has been shown to differ from that observed in long leg radiographs (Deep 2011). Potential explanations for this discrepancy may be the effect of weight bearing or the dynamic contributions of soft tissue loads. Method. A validated, 3D, dynamic patient specific musculoskeletal model was used to analyse 85 post-operative CT scans using a common implant design. Differences in coronal and axial plane tibio-femoral alignment in three separate scenarios were measured:. Unloaded as measured in a post-op CT. Unloaded, with femoral and tibial components set aligned to each other. Weight bearing with the extensor mechanism engaged. Scenario number two illustrates the tibio-femoral alignment when the femoral component sits congruently on the tibia with no soft tissue acting whereas scenario three is progression of scenario number two with weight applied and all ligaments are active. Two tailed paired students t-test were used to determine significant differences in the means of absolute difference of axial and coronal alignments. Results. The mean coronal alignment were 1.7° ± 2.1° varus (range, −3.0° to 7.0°), 0.8° ± 2.0° varus (range, −3.7° to 4.8°), 0.4° ± 2.0° varus (range, −3.9° to 5.1°) for unloaded, unloaded with implants set aligned and weight bearing scenarios respectively. The mean of absolute difference in coronal alignment between the unloaded and weight bearing scenario was 1.8° ± 1.5° (range 0.0° to 5.9°). The mean
Aims. We investigated changes in the
Introduction. Patellofemoral arthroplasty (PFA) can give excellent results in well-selected patients.