Preoperative ligament laxity can be characterized intraoperatively using digital robotic tensioners. Understanding how preoperative knee joint laxity affects preoperative and early post-operative patient reported outcomes (PROMs) may
Introduction. There is debate regarding whether the use of computer-assisted technology, such as navigation and robotics, has any benefit on clinical or patient reported outcomes following total knee arthroplasty (TKA). This study aims to report on the association between intraoperative use of technology and outcomes in patients who underwent primary TKA. Methods. We retrospectively reviewed 7,096 patients who underwent primary TKA from 2016–2020. Patients were stratified depending on the technology utilized intraoperatively: navigation, robotics, or no technology. Patient demographics, clinical data, Forgotten Joint Score-12 (FJS), and Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) were collected at various time points up to 1-year follow-up. Demographic differences were assessed with chi-square and ANOVA tests. Clinical data and mean FJS and KOOS, JR scores were compared using univariate ANCOVA, controlling for demographic differences. Results. During the study period, 287 (4%) navigation, 367 (5%) robotics, and 6,442 (91%) manual cases were performed. Surgical time significantly differed between the three groups (113.33 vs. 117.44 vs. 102.11 respectively; p<0.001). Discharge disposition significantly differed between the three groups (p<0.001), with a greater percentage of patients who underwent manual TKA discharged to a skilled nursing facility (12% vs. 8% vs. 15%; p<0.001) than those who had intraoperative technology utilized. FJS scores did not statistically differ at 3-months (p=0.067) and 1-year (p=0.221) postoperatively. There was a significant statistical difference in three-month KOOS, JR scores (59.48 vs. 60.10 vs. 63.64; p=0.001); however, one-year scores did not statistically differ between the three groups (p=0.320). Mean improvement in KOOS, JR scores preoperatively to one-year postoperatively was significantly largest for the navigation group and least for robotics (27.12 vs. 23.78 vs. 25.42; p<0.001). Conclusion. This study demonstrates shorter mean operative time in cases with no utilization of technology and clinically similar patient reported outcome scores associated with TKAs performed between all modalities. While the use of intraoperative technology may
Background. The transverse acetabular ligament (TAL) has been described as an anatomic landmark to guide in the positioning of the acetabular component during total hip arthroplasty. On plain films, the radiographic teardrop (RT) has similarly been utilized as a measure of appropriate cup positioning. The goal of this study is to quantify the distance and location between the anatomic TAL and RT landmarks to aid in the positioning of acetabular component. Methods. Sixteen randomly selected cadaveric pelvises (eight male, eight female) underwent dissection. Radiographic markers were placed bilaterally at the anteromedial insertions of the TAL, and true anteroposterior (AP) pelvic radiographs of the cadavers were obtained. Distances between the markers and the lateral borders of the RT were measured. Results. The mean distance between the anteromedial insertion of the TAL and the lateral border of the RT in the male specimens was 11.8 [99% CI, 11.4 to 12.2] mm. In the female specimens, the TAL to RT distance was shorter, with a mean of 8.4 [99% CI, 7.2 to 9.6] mm. There was a statistically significant difference between male and female cadavers (p<0.01). Conclusions. The distance between the RA and TAL differs between males and females. Understanding the distance between these anatomic and radiographic landmarks should
Introduction. Clinical decision support tools are software that match the input characteristics of an individual patient to an established knowledge base to create patient-specific assessments that support and better inform individualized healthcare decisions. Clinical decision support tools can facilitate better evidence-based care and offer the potential for improved treatment quality and selection, shared decision making, while also standardizing patient expectations. Methods. Predict+ is a novel, clinical decision support tool that leverages clinical data from the Exactech Equinoxe shoulder clinical outcomes database, which is composed of >11,000 shoulder arthroplasty patients using one specific implant type from more than 30 different clinical sites using standardized forms. Predict+ utilizes multiple coordinated and locked supervised machine learning algorithms to make patient-specific predictions of 7 outcome measures at multiple postoperative timepoints (from 3 months to 7 years after surgery) using as few as 19 preoperative inputs. Predict+ algorithms predictive accuracy for the 7 clinical outcome measures for each of aTSA and rTSA were quantified using the mean absolute error and the area under the receiver operating curve (AUROC). Results. Predict+ was released in November 2020 and is currently in limited launch in the US and select international markets. Predict+ utilizes an interactive graphical user interface to facilitate efficient entry of the preoperative inputs to generate personalized predictions of 7 clinical outcome measures achieved with aTSA and rTSA. Predict+ outputs a simple, patient-friendly graphical overview of preoperative status and a personalized 2-year outcome summary of aTSA and rTSA predictions for all 7 outcome measures to aid in the preoperative patient consultation process. Additionally, Predict+ outputs a detailed line-graph view of a patient's preoperative status and their personalized aTSA, rTSA, and aTSA vs. rTSA predicted outcomes for the 7 outcome measures at 6 postoperative timepoints. For each line-graph, the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) patient-satisfaction improvement thresholds are displayed to
Instrumented fusion for lumbar degenerative spondylolisthesis (LDS) has been challenged recently with high impact trials demonstrating similar changes in health-related quality of life (HRQOL) and less morbidity/cost with laminectomy alone. Randomized trials often fail, however, to evaluate a heterogeneous population of patients. A standardized clinical assessment and management plan (SCAMP) was created as a decision
Background. The constraint of total knee replacement (TKR) implants is not simply defined and many of the factors that influence it are not well understood. Variability in the constraint of different TKR implants designed for the same indication (e.g. cruciate-retaining, or posterior-stabilized) have been previously demonstrated, but these differences among implants have yet to be simply quantified. Furthermore, the relative importance of several variables on the implant constraint remains unknown. The purpose of this study was to quantify the differences in constraint that exist between different implant designs, and to examine the effects of axial load and flexion angle on the constraint of current cruciate-retaining (CR) TKR components. Methods. Four contemporary CR TKR designs underwent laxity testing using a multi-axis mechanical test machine. Implants were tested at flexion angles of 0°, 20°, 90° and maximum flexion and axial loads of 712 N (1 BW) and 1424 N (2 BW). Friction-free motion in all secondary degrees of freedom was allowed. Force-displacement curves were generated for each testing condition in both anterior-posterior (AP) and rotational tests. AP constraint (N/mm) and rotational constraint (Nm/deg) were then calculated. Results. Differences in the AP and rotational constraint of the various implants were identified. The rotating platform implant was the most AP constrained and least rotationally constrained of the implants studied. Among the fixed bearing implants, NexGen CR had less AP and rotational constraint than the Genesis II and PFC Sigma. Doubling the applied axial load during the laxity tests resulted in a significant increase in both AP (p<0.0001) and rotational (p<0.0001) constraint. AP and rotational constraint decreased with increasing flexion angles. Conclusion. The constraints of four contemporary CR TKR designs were quantitatively compared and ranked according to their calculated constraints. Differences in the constraint of these designs were identified. This quantitative analysis is an important step towards the creation of a clinically meaningful constraint index that would
Purpose. The incidence of hip displacement in children with cerebral palsy is approximately 30% in large population based studies. The purpose of this study was to report the long-term effect of hip surgery on the incidence of hip displacement using a newly validated Cerebral Palsy (CP) hip classification. Method. Retrospectively, a sub-group of 100 children who underwent surgery for hip displacement were identified from a large-population based cohort of children born with CP between January 1990 and December 1992. These children were followed to skeletal maturity and closure of their tri-radiate cartilage. All patients returned at maturity for clinical and radiographic examination, while caregivers completed the disease specific quality of life assessments. Patients were grouped according to motor disorder, topographical distribution and GMFCS. Radiographs were independently graded according to CP hip classification scheme to ensure reliability. Surgical Failures were defined as CP Grade > IV. Results. Ninety-seven children and 194 hips were available for final review. According to GMFCS, greater than half the children were GMFCS IV and V (67/94, 67%), 12 were II and 18 were III. Fifteen hips were dislocated or had salvage surgery for dislocation (15/194, 7.7%) at time of skeletal maturity. The majority of hips were graded Grade II and III (149/194, 76.8%). A total of 39 (39/194, 20%) hips were classified as surgical failure with 95% (37/39) hips occurring in GMFCS IV and V children. Conclusion. Using the CP hip classification scheme, the natural history and outcome of 100 children with CP at skeletal maturity have been described. Despite hip surveillance and surgical intervention GMFCS IV and V children are at the greatest risk for surgical failure at skeletal maturity. In this study, the majority of failures were associated with either no hip surveillance and/or index surgery at a non-specialist centre. In contrast, hip surveillance and index surgery at a specialist tertiary centre was associated with a very high probability of a successful outcome. This is the first population based cohort study of children with cerebral palsy followed from index surgery to skeletal maturity for hip displacement. Surgical success rates for the treatment of hip displacement in children with cerebral palsy have not previously been reported. This information will
The Delto-pectoral approach is the workhorse of the shoulder surgeon, but surprisingly the common variants of the cephalic vein and deltoid artery have not been documented. The vascular anatomy encountered during one hundred primary elective delto-pectoral approaches was documented and common variants described. Two common variants are described. A type I (71%), whereby the deltoid artery crosses the interval and inserts directly in to the deltoid musculature. In this variant the surgeon is unlikely to encounter any vessels crossing the interval apart from the deltoid artery itself. In a type II pattern (21%) the deltoid artery runs parallel to the cephalic vein on the deltoid surface and is highly likely to give off medial branches (95%) that cross the interval, as well as medial tributaries to the cephalic vein (38%). Knowledge of the two common variants will
Purpose. Intra-articular fractures of the distal radius are common injuries. Their pathogenesis involves a complex combination of forces, including ligament tension, bony compression and shearing, leading to injury patterns that challenge the treating surgeon. The contribution of the radiocarpal and radioulnar ligaments to articular fracture location has not previously been described. Computed tomography (CT) scanning is an important method of evaluating intra-articular distal radius fractures, revealing details missed on plain radiographs and influencing treatment plans. Methods. We retrospectively reviewed CT scans of acute intra-articular distal radius fractures performed in one institution from June 2001 to June 2008. Forty- five of 145 scans were deemed unsuitable due to poor quality or presence of internal fixation in the distal radius, leaving 100 fractures for review. Fracture line locations were mapped to a standardised distal radius model, and statistically analysed in their relationship to ligament attachment zones. Results. Distal radius articular fracture lines are significantly less likely to occur in the regions of ligament attachment. Conversely, fracture lines are more likely to occur in the gaps between major ligament attachments. Conclusion. Articular fracture locations in the distal radius are significantly related to radiocarpal and radioulnar ligament attachments. This may
Introduction. Despite improvements in prosthesis design, the clinical outcome of total hip arthroplasty still has 10% failure rate after 10 years. Component malpositioning can lead to instability, impingement, excessive wear and loosening. Computer-assisted procedures are expected to improve the accuracy of component positioning, and therefore the long-term outcome. We present an original hip navigation system that allows controlling leg lengthening, offset and stability without the use of the pelvic anterior plane. Material and Methods. Because the reliability of the pelvic anterior plane (Lewinnek plane) remains discussed, we present a computer-assisted hip replacement using a functional femoral reference plane. Direction and depth of the acetabular reaming and progression of the femoral rasp are calculated by a sophisticated algorithm, as well as the components' final position, in order to control leg lengthening and offset. In addition, the ROM to impingement (and therefore the stability) is continuously displayed relative to the position of the components. Simple graphical and numerical data in addition to virtual instruments displayed on the screen
