Project description:BackgroundTotal knee arthroplasty (TKA) is considered the most efficient treatment of end-stage osteoarthritis. There is an ongoing debate about proper implant designs and articulation types. One of the considered causes of unsatisfactory outcome and patients' dissatisfaction is femoral or tibial component overhanging, which can lead to chronic knee pain and restricted motion. The aim of this study is to compare radiological outcomes of TKA using an anatomic PERSONA Posterior-Stabilized (PS) knee design with its nonanatomic predecessor, the NexGen LPS.MethodsA group of 39 patients who received the PERSONA PS system and 33 patients who received the NexGen LPS was included. PERSONA patients were matched to NexGen patients using a 0.1 propensity score threshold with priority given to exact matches. Anteroposterior, lateral, and long-leg radiographs were taken preoperatively and at 6 weeks postoperatively to perform radiological and statistical analysis.ResultsThe PERSONA subgroup had statistically higher posterior condylar offset. There is no statistically significant difference in posterior condylar offset ratio. There were less cases of femoral notching, femoral overhang, and placing tibial baseplate in the medial overhang in the PERSONA PS subgroup than in the NexGen subgroup (each statistically significant). Occurrence of tibial underhang was not statistically significant.ConclusionRadiological assessment in short-term follow-up showed excellent results for PERSONA knee design with better fit to native femur and tibia. In comparison to its predecessor, it also spares more bone tissue. As the aforementioned parameters are risk factors of lesser clinical outcomes, the PERSONA design gives high hopes for improvement of TKA satisfaction rate.
Project description:Background Total wrist arthroplasty (TWA) is a viable surgical treatment for disabling wrist arthritis. While current designs are a notable improvement from prior generations, radiographic loosening and failures remain a concern. Purpose The purpose of this investigation is to evaluate a new total wrist arthroplasty design kinematically. The kinematic function of a native, intact cadaveric wrist was compared with that of the same wrist following TWA. Method Six, fresh-frozen wrist cadaveric specimens were utilized. Each wrist was fixed to an experimental table and its range of motion, axis of rotation, and muscle moment arms were calculated. The following tendons were attached to the apparatus to drive motion: extensor carpi radialis longus (ECRL), extensor carpi radialis brevis (ECRB), extensor carpi ulnaris (ECU), flexor carpi radialis (FCR), flexor carpi ulnaris (FCU), and abductor pollicis longus (APL). The wrist was then manually moved along a guide by an experimenter through a series of motions including flexion-extension, radial-ulnar deviation, and circumduction. The experiment was then performed on the specimen following implantation of the TWA. Results Following the TWA procedure, there were statistically significant decreases in the ulnar deviation and the flexion/ulnar deviation component of dart throw ranges of motion. There were no statistically significant changes in flexion, extension, radial deviation, the extension/radial deviation component of the dart thrower motion, or the circumduction range of motion. Conclusions Kinematic analysis of the new TWA suggests that a stable, functional wrist is achievable with this design. Clinical Relevance While appreciating the limitations of a cadaveric study, this investigation indicates that the TWA design studied merits study in human populations.
Project description:Successful total shoulder arthroplasty relies on a multitude of factors specific to patients, implant selection, and surgical technique. Among technical factors, correct intraoperative placement of prosthetic components is paramount. Three-dimensional computed tomography has emerged as a vital tool, allowing surgeons to measure glenoid inclination, glenoid version, and humeral head subluxation more accurately and reproducibly. Several commercial preoperative planning software resources are available to determine the optimal size and positioning of prosthetic components yet do so at significant cost and with meaningful time constraints. At our institution, we have applied the principles of these technologies to develop a custom, 3-dimensionally printed glenoid guide for accurate placement of the central pin. In this technical note, we describe our evaluation of patients with glenohumeral arthritis, as well as our step-by-step procedure for designing and printing a custom patient-specific instrumentation glenoid guide for anatomic total shoulder arthroplasty.
Project description:Head and neck reconstruction is a technically challenging procedure. Variations encountered in the recipient vessels and commonly used flaps add to the complexity of surgery. This article reviews the commonly encountered variations in the recipient vessels in the neck with emphasis on alternatives and techniques to circumvent these variations. Flaps commonly used in head and neck reconstruction are also reviewed in detail. Furthermore, safety, potential pitfalls, and technical pearls are highlighted.
Project description:BACKGROUND:The purpose of this study was to compare restoration of mechanical limb alignment and three-dimensional component-positioning between conventional and patient-specific instrumentation in total knee arthroplasty. METHODS:Radiographic data of patients undergoing mobile-bearing total knee arthroplasty (n = 1257), using either conventional (n = 442) or patient-specific instrumentation (n = 812), were analyzed. To evaluate accuracy of axis restoration and 3D-component-positioning between conventional and patient-specific instrumentation, absolute deviations from the targeted neutral mechanical limb alignment and planned implant positions were determined. Measurements were performed on standardized coronal long-leg and sagittal knee radiographs. CT-scans were evaluated for accuracy of axial femoral implant rotation. Outliers were defined as deviations from the targeted neutral mechanical axis of > ±?3° or from the intraoperative component-positioning goals of > ±?2°. Deviations greater than ±?5° from set targets were considered to be severe outliers. RESULTS:Deviations from a neutral mechanical axis (conventional instrumentation: 2.3°± 1.7° vs. patient-specific instrumentation: 1.7°± 1.2°; p < 0.001) and numbers of outliers (conventional instrumentation: 25.8% vs. patient-specific instrumentation: 10.1%; p < 0.001) were significantly lower in the patient-specific instrumentation group. Significantly lower mean deviations and less outliers were detected regarding 3D-component-positioning in the patient-specific instrumentation compared to the conventional instrumentation group (all p < 0.05). CONCLUSIONS:Patient-specific instrumentation prevented from severe limb malalignment and component-positioning outliers (> ±?5° deviation). Use of patient-specific instrumentation proved to be superior to conventional instrumentation in achieving more accurate limb alignment and 3D-component positioning, particularly regarding femoral component rotation. Furthermore, the use of patient-specific instrumentation successfully prevented severe (>?5° deviation) outliers.
Project description:BackgroundTotal knee arthroplasty using patient-specific instrumentation (TKA-PSI), which are disposable cutting block guides generated to fit each patient's 3-dimensional knee anatomy, has been developed to treat patients with end-stage osteoarthritis of the knee. Surrogate markers such as radiographic malalignment have been well investigated, however, patient-important outcomes are not well examined to elucidate the efficacy of TKA-PSI. The aim of this review is to determine if TKA-PSI improves patient-reported outcome measures (PROM), surgery time, blood loss, transfusion and complications (e.g. surgical site infection, deep venous thrombosis, and revision TKA).MethodsWe searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and ongoing clinical trials. For PROMs, surgery time, blood loss, and transfusion rate, we included randomized controlled trials (RCT) comparing TKA-PSI and standard TKA to treat osteoarthritis of the knee. For complications, we also included non-randomized comparative studies (non-RCT).ResultsThis review includes 38 studies, 24 of which were RCT and 14 of which were non-RCT. These included a total of 3487 patients. The predominant population in the included studies highly reflected the general population, with 62% being female, aged over 60 and having end-stage osteoarthritis of the knee. TKA-PSI did not improve PROMs as compared to standard TKA for less than 1-year (mean difference 0.48, 95% confidence interval (CI) -1.92-0.97 in the Oxford knee score, mean 3-month follow-up) and for 1-year or more (mean difference 0.25, 95%CI - 4.39-4.89 in the WOMAC score, mean 29-month follow-up). TKA-PSI did not reduce surgery time (mean difference - 3.09 min, 95%CI -6.73-0.55). TKA-PSI decreased blood loss with a small effect size corresponding to a 0.4 g/dl hemoglobin decrease (95%CI 0.18-0.88), but did not decrease transfusion rate (risk difference - 0.04, 95%CI -0.09-0.01). TKA-PSI did not reduce complication rates (risk difference 0.00, 95%CI - 0.01-0.01 in the composite outcome).ConclusionsTKA-PSI does not improve patient-reported outcome measures, surgery time, and complication rates as compared to standard TKA. TKA-PSI decreases blood loss with a small effect, which is not enough to reduce transfusion rate.
Project description:IntroductionEarly postoperative pain following total knee arthroplasty significantly impacts outcomes and patient satisfaction. However, the characteristics and sources of early pain after total knee arthroplasty remain unclear. Therefore, the purpose of this study was to determine the anatomic distribution and course of postoperative pain in the acute and subacute period following total knee arthroplasty.MethodsA prospective observational study of primary, elective unilateral total knee arthroplasty cases was conducted at our academic tertiary care medical center from January 2021 to September 2021. Preoperative variables were extracted from institutional electronic medical records. Postoperatively, patients utilized a knee pain map to identify the two locations with the most significant pain and rated it using the visual analog scale (VAS). The data were collected on day 0, at 2 weeks, 2 months, and 6 months after operation.ResultsThis study included 112 patients, with 6% of patients having no pain at postoperative day 0, 22% at 2 weeks, 46% at 2 months, and 86% at 6 months after operation. In those who reported pain, the VAS score (mean ± standard deviation) was 5.8 ± 2.4 on postoperative day 0 and decreased at each follow-up time point (5.4 ± 2.3 at 2 weeks, 3.9 ± 2.2 at 2 months, and 3.8 ± 2.7 at 6 months). The majority of patients were able to identify distinct loci of pain. The most common early pain loci were patellae, thigh, and medial joint line, and this distribution dissipated by 6 months.ConclusionAt 2 postoperative weeks, pain was primarily at the medial joint, and at 6 months postoperatively, pain was more likely to be at the lateral joint. No relationship was found between pain at six months and pain scores or location at postoperative day 0 or 2 weeks. Understanding the distribution and progression of knee pain following total knee arthroplasty may benefit patient education and targeted interventions.Level of evidenceLevel II, prospective observational study.
Project description:Patient-specific implants have been linked to stiffness. The purpose of this study was to evaluate outcomes in patient-specific implants. We performed a retrospective review with a primary outcome of manipulation under anesthesia (MUA); secondary outcomes included Knee Society Scores (KSS), Knee Society Functional Scores (KSFS), range of motion (ROM), and Forgotten Joint Scores (FJS). Pre-operative measurements were similar in both groups. There was one MUA in the CPS and two in the OTS groups. There was no difference in postoperative scores. Our study suggests patient-specific implants have comparable rates of MUA and functional outcomes as conventional implants.
Project description:Tibiofemoral slip velocity is a key contributor to total knee arthroplasty (TKA) component wear, yet few studies have evaluated this quantity in vivo. The aim of the present study was to measure and compare tibiofemoral slip velocities in 3 TKA designs for a range of daily activities. Mobile biplane X-ray imaging was used to measure 6-degree-of-freedom tibiofemoral kinematics and the locations of articular contact in 75 patients implanted with a posterior-stabilized, cruciate-retaining, or medial-stabilized design while each patient performed level walking, step up, step down, sit-to-stand, and stand-to-sit. Using these data, tibiofemoral slip velocity was calculated for the duration of each activity for each TKA design. The pattern of tibiofemoral slip velocity was similar for all 3 TKA designs within each activity but markedly different across the 5 activities tested, with the magnitude of peak slip velocity being significantly higher in level walking (range: 158-211 mm/s) than in all other activities (range: 43-75 mm/s). The pattern of tibiofemoral slip velocity in both the medial and lateral compartments closely resembled the pattern of tibiofemoral (knee) flexion angular velocity, with a strong linear relationship observed between slip velocity and flexion angular velocity (r = 0.81-0.97). Tibiofemoral slip velocity was invariant to TKA design but was significantly affected by activity type. Our measurements of slip velocity and articular contact locations for a wide range of daily activities may be used as inputs in joint simulator testing protocols and computational models developed to estimate TKA component wear.