Return to Work After Total Joint Arthroplasty: A Predictive Model.

Returning to work after surgery is a primary concern of patients who are contemplating total joint arthroplasty (TJA). The ability to return to work has enormous influence on the patient's independence, financial well-being, and daily activities. The goal of this study was to determine the independent patient variables that predict return to work as well as to create a predictive model. From June 2017 to December 2017, a total of 391 patients who underwent primary TJA (243 hips, 148 knees) were prospectively enrolled in the study to obtain information on return to work after surgery. Patients were sent a series of questions in a biweekly survey. Information was collected on the physical demands of their occupation, the number of hours spent standing, the limitations to return to work, and the use of assistive devices. Bivariate analysis was performed, and a multiple linear regression model was created. Most (89.6%) patients returned to work within 12 weeks of surgery. Patients who underwent total hip arthroplasty returned to work earlier than those who underwent total knee arthroplasty (5.56 vs 7.79 weeks, respectively). Analysis showed the following independent predictors for faster return to work: self-employment, availability of light-duty work, male sex, and higher income. Predictors for slower return to work included a physically demanding occupation (at least 50% physical duties), knee arthroplasty, longer length of stay, and a job requiring more hours spent standing. This model reported an adjusted R2 of 0.332. The findings provide an objective predictive model of the patient- and procedure-specific characteristics that affect postoperative return to work. Surgeons should consider these factors when counseling patients on their postoperative expectations. [Orthopedics. 2020;43(5):e415-e420.].

High-load preconditioning of human soft tissue hamstring grafts: An in vitro biomechanical analysis.

PURPOSE: In order to minimize viscoelastic elongation of ACL reconstruction grafts, preconditioning protocols have been employed in clinical practice prior to final graft fixation. The purpose of this study was to evaluate two separate high-load static preconditioning protocols of double-looped semitendinosus-gracilis grafts and compare these results to both a current clinical protocol and a control group with no preconditioning protocol applied. It was hypothesized that a high-load, static preconditioning protocol would minimize graft elongation during a simulated progressive early rehabilitation compared to both the "89 N" clinical protocol and control groups. METHODS: Grafts were randomly allocated into four preconditioning study groups: (1) control (no preconditioning), (2) clinical protocol (89 N for 15 min), (3) high-load, short duration (600 N for 20 s), and (4) high-load, long duration (600 N for 15 min). After preconditioning, grafts were cyclically loaded between 10 and 400 N at 0.5 Hz for 450 cycles to simulate early postoperative rehabilitation. Graft displacement (elongation) was recorded during both preconditioning and cyclic loading. RESULTS: Increased preconditioning load magnitude and duration significantly reduced graft elongation during cyclic loading (p < 0.05) which corresponded to an inverse relationship with increased elongation during preconditioning. The "600 N for 15 min" protocol resulted in significantly less elongation during simulated early rehabilitation than both the control group and the "89 N for 15 min" protocol (p < 0.001, p < 0.05). CONCLUSIONS: Graft elongation during simulated early rehabilitation was significantly reduced by a high-load preconditioning protocol applied for an extended period of time compared to a current common clinical protocol and grafts that were not preconditioned. In addition, the amount of elongation during simulated early rehabilitation was similar between grafts preconditioned using the current clinical practice protocol and the high-load/short-duration protocol, implying that the latter could potentially induce the same viscoelastic changes in soft tissue grafts as the current clinical practice. The "600 N for 20 s" preconditioning protocol may provide similar postoperative results as the clinical protocol, "89 N for 15 min", and also reduce or maintain operative time. A high-load preconditioning protocol that reduces graft elongation may benefit patients undergoing ACL reconstruction, especially for cases of failed primary reconstruction, genu recurvatum, and increased tibial slope, where maintaining graft length is imperative to restore knee stability.

Biomechanical Results of Lateral Extra-articular Tenodesis Procedures of the Knee: A Systematic Review.

PURPOSE: To systematically review and compare biomechanical results of lateral extra-articular tenodesis (LET) procedures. METHODS: A systematic review was performed using the PubMed, Medline, Embase, and Cochrane databases. The search terms included the following: extraarticular, anterolateral, iliotibial, tenodesis, plasty, augmentation, procedure, reconstruction, technique, biomechanics, kinematic, robot, cadaver, knee, lateral tenodesis, ACL, Marcacci, Lemaire, Losee, Macintosh, Ellison, Andrews, Hughston, and Muller. The inclusion criteria were nonanatomic, in vitro biomechanical studies, defined as in vitro investigations of joint motion resulting from controlled, applied forces. RESULTS: Of the 10 included studies, 7 analyzed anterior tibial translation and reported that isolated LET procedures did not restore normal anterior stability to the anterior cruciate ligament (ACL)-deficient knee. Seven of the 8 studies analyzing tibial rotation reported a reduction in internal tibial rotation across various flexion angles in the ACL-deficient knee when compared with the native state. Five studies reported a reduction in intra-articular graft force with the addition of an LET. Two studies evaluated length change patterns, graft course, and total strain range and found that reconstruction techniques in which the graft attached proximal to the lateral epicondyle and coursed deep to the fibular collateral ligament were most isometric. CONCLUSIONS: In the ACL-deficient knee, LET procedures overconstrained the knee and restricted internal tibial rotation when compared with the native state. In addition, isolated LET procedures did not return normal anterior stability to the ACL-deficient knee but did significantly reduce anterior tibial translation and intra-articular graft forces during anteriorly directed loading. CLINICAL RELEVANCE: Combined injury to the ACL and anterolateral structures has been reported to exhibit greater anterolateral rotatory instability when compared with isolated ACL injuries. Despite the reported risk of joint over-constraint, consideration should be given to reconstructing the anterolateral structures and the ACL concurrently to maximally restore both anterior tibial translation and rotatory stability.