Journal of Knee Surgery最新文献

Categorization of alignment into phenotypes can be useful for predicting and analyzing postoperative alignment changes after opening-wedge high tibial osteotomy (OWHTO). The purposes of this study were to (1) develop a machine learning model for the predicting the Coronal Plane Alignment of the Knee (CPAK) phenotypes of final alignment after OWHTO, and (2) analyze predictive factors for final alignment phenotypes. Data were retrospectively collected from 163 knees that underwent OWHTO between March 2014 and December 2019. Each data were assessed at three time points: preoperatively, at 3 months postoperatively, and the final follow-up. Constitutional alignment was also evaluated. Machine learning models were developed using two independent feature sets consisting of serial radiologic parameters and CPAK phenotypes. The area under the receiver-operating characteristic curve (AUC) was used as a primary metric to determine the best model. To evaluate the feature importance, Shapley additive explanation (SHAP) analysis was also performed on the best model. Multilayer perceptron (MLP) was the best prediction model, with the highest AUC of 0.867 based on radiologic parameters and 0.783 based on CPAK phenotypes. Joint line obliquity (JLO) at 3 months postoperatively was the most important factor among the radiologic parameters for predicting the final CPAK phenotypes. The features of constitutional and preoperative alignments also contributed, although the features of alignments at 3 months postoperatively were the highest contributing predictors. In conclusion, the developed machine learning models of the MLP showed excellent performance in predicting the final CPAK phenotypes after OWHTO. Postoperative JLO was the most important radiologic parameter for predicting the final alignment. The combination of features of the constitutional, preoperative, and postoperative periods enabled high accuracy and performance in predicting the final alignment.A retrospective cohort study with the level of evidence as level III.

Purpose: To synthesise and qualitatively assess the currently available evidence in the literature regarding the revision of posterior cruciate ligament (PCL) reconstruction.

Methods: A systematic review was conducted on the basis of the PRISMA guidelines. The outcome data extracted from the studies were the Lysholm score, Orthopadische Arbeitsgruppe Knie (OAK) scoring system, KT-2000, International Knee Documentation Committee (IKDC) subjective and objective, radiological changes, rate of return to sports, complications, and failures and/or revision surgeries.

Results: The cohort consisted of 54 patients (42 [77.8%] men and 12 [22.2%] women), with a mean age of 33.14 ±3.67 years (range 17-48 years). The mean postoperative follow-up was 71.8 ±45.32 months, whereas the mean time from primary surgery to revision was 41.7 ±4.5 months. All studies reported a clinical improvement from preoperative to final follow-up in terms of the Lysholm, OAK, KT-2000, and IKDC scores (p<0.05). Posterior displacement was significantly improved in all studies, demonstrating the stability of the knee. The mean posterior displacement ranged from a preoperative value of 10.68 ±0.7 mm to a final value of 2.7 ±0.2 mm (p<0.05). A total of two (3.7%) failures were reported, and there were also eight (14.8%) revision surgeries.

Conclusions: Studies on posterior cruciate ligament reconstruction revisions have shown satisfactory clinical outcomes and a high level of knee stability, with a minimal risk of new reruptures. However, the rate of returning to preinjury sports activity is relatively low. Whenever possibile, it is recommended to perform the ligament revision in a single stage.

As the population ages and the prevalence of knee osteoarthritis increases, total knee arthroplasty (TKA) is expected to grow in demand. Traditionally, the success of TKA has been measured through clinical assessments, imaging, and the incidence of postoperative complications. Over the past decade, patient-reported outcome measures (PROMs) have become crucial in evaluating clinical outcomes. PROMs are soon to be tied to financial incentives in value-based payment programs as a measure of the quality of care provided. Centers for Medicare & Medicaid Services (CMS) has implemented a nationwide policy to enhance and standardize the collection of PROMs for those undergoing total joint arthroplasty. The policy is titled Patient Reported Outcome-based Performance Measure or "PRO-PM". This requires mandatory reporting in 2025, and by 2028, hospital payment evaluations will incorporate this data. CMS will require hospitals to achieve at least 50% postoperative PROM collection rates to qualify for full annual payment in 2028. Providers are incentivized to improve scores on PROMs, such as pain levels and physical function after procedures, as higher PROM scores often correlate with better reimbursement rates under these programs. Recent advancements in interactive technology, including mobile apps and telemedicine platforms, have enabled the collection of PROMs from patients without requiring or prior to a clinic visit. Looking ahead, the mandatory PROM reporting requirements set by the CMS highlight the urgency of adopting scalable, technology-driven solutions. Literature suggests women, individuals with lower socioeconomic status, lower educational attainment, and non-English speakers have significantly lower PROM response rates. While these mandates aim to standardize care quality, they also risk exacerbating disparities if underserved populations face barriers to participation. Equity-focused strategies, alongside continued investment in technology, will be critical to achieving widespread adoption and maximizing the benefits of PROMs in TKA care. Ultimately, the integration of electronic and adaptive PROM systems has the potential to transform the TKA landscape, offering a model for leveraging technology to enhance patient engagement, optimize care delivery, and improve outcomes across diverse populations.

Introduction: Varus producing distal femoral osteotomy (DFO) is an established procedure to correct genu valgum in patients with osteoarthritis and gait abnormalities. DFO has also been proposed for the treatment of patellar instability in patients with valgus alignment. However, it is not known how DFO affects parameters associated with patellar instability. This study evaluated radiographic changes after DFO with variable degree of correction on six cadaveric knees, with the hypothesis that improving mechanical alignment would improve radiographic parameters related to patellar instability.

Materials/methods: Six lower-limb cadaveric specimens were obtained after approval by the Institutional Review Board. A lateral opening wedge DFO was performed on each specimen with correction blocks of 6, 10, and 14 millimeters. The mechanical axis, tibiofemoral angle (mTFA), distal femoral angle (mDFA), Caton Deschamps Index (CDI), Insall Salvati Index (ISI), tibial tubercle to trochlear groove distance (TT-TG), and patellofemoral congruence angle (PFCA) were measured on computed tomography (CT) scans at baseline and after each correction block.

Results: At baseline, a mean varus alignment of the limbs was observed (mTFA: 2.7 2.8°, mDFA: 87.61.0°). The baseline patellar height was normal (CDI: 0.90.2, ISI: 1.00.1). Statistically significant decreases in mechanical axis and TT-TG distance and increases in mDFA and mFTA were found with increasing block size. The TT-TG distance was decreased by -1.6 mm (95% CI: -2.27 to -0.86), -3.8 mm (95% CI: -4.8 to -2.8), and -4.0 mm (95% CI: -5.4 to -2.7) with a 6, 10, and 14 mm block, respectively. No differences were observed in patellar height when measured with CDI or ISI after any block size.

Conclusion: In a cadaveric model, DFO significantly affects the mechanical axis and TT-TG distance. Specifically, this study found a mean decrease in TT-TG of -3.8 mm when performing a 10 mm opening wedge osteotomy. No changes in patellar height were observed.

Key terms: Patellar instability; distal femoral osteotomy; genu valgum; radiologic measurements .

Background: This study examined the impact of preoperative Coronal Plane Alignment of the Knee (CPAK) classification on intraoperative soft tissue balance and postoperative clinical outcomes in patients undergoing modified kinematically aligned (mKA) and mechanically aligned (MA) total knee arthroplasty (TKA).

Method: A total of 90 knees treated with mKA-TKA and 63 knees treated with MA-TKA were classified based on CPAK. After adjusting for confounding factors, intraoperative soft tissue balance, including varus/valgus balance and joint component gap, range of motion (ROM), and the 2011 Knee Society Score (KSS), were compared one year postoperatively using one-way ANOVA.

Results: The analysis included 69 knees classified as Type I and 18 Type II in the mKA group, and 52 Type I and 11 Type II in the MA group. Varus balance at 30° and 60° flexion were significantly larger in mKA Type I and MA Type I compared to mKA Type II (p<0.001, 0.005, <0.001, 0.008). At 90°, mKA Type I showed larger varus balance than both MA Type I and mKA Type II (p=0.008, 0.002), while at 120°, mKA Type I demonstrated larger varus balance than MA Type I (p<0.001). The improved ROM in mKA Type I was greater than in MA Type I (p=0.04). Improvement in the objective indicator of the 2011 KSS was better in mKA Type I than in mKA Type II, and patient satisfaction was significantly better in mKA Type I compared to both mKA Type II and MA Type I (p=0.01, <0.001, 0.03).

Conclusion: mKA Type I preserved lateral laxity in mid- and deep flexion compared to both mKA Type II and MA Type I, potentially contributing to improved ROM and clinical outcomes.

Patellofemoral offset is influenced by patellar thickness in total knee arthroplasty (TKA), with effects on extensor mechanism efficiency (EME), patellar contact moment arm (PCMA), and patellar contact force (PCF). This study utilized a computational model to better quantify these measures during knee range of motion (ROM).A computational model of a cruciate-sacrificing, posterior-stabilized TKA design was used to quantify moments at knee flexion angles from 0° to 135° when patella thickness was increased ("overstuffed") or decreased ("understuffed") by 2 mm and 5 mm from normal. Outcomes included changes in EME, PCMA, PCF, tibial tubercle moment arm (TTMA), and the quadriceps moment arm (QMA).Overstuffing of the patellofemoral articulation by 2 mm and 5 mm decreased EME up to 12 and 28%, respectively, with an 8% and 16% increase in EME with understuffing that peaked at 25° knee flexion. The QMA increased up to 5 and 12% with overstuffing by 2 mm and 5 mm and decreased up to 5% and 14% with understuffing, respectively. There was an increase in the PCMA/PCF, which opposed the QMA, up to 8%/17% and 16%/39% with overstuffing by 2 mm and 5 mm, respectively. The PCMA/PCF decreased up to 3%/12% and 8%/33% with understuffing by 2 mm and 5 mm, respectively.In this computational model, increased patellofemoral offset resulting in overstuffing of the patella resulted in decreased EME and increased PCMA and PCF during knee ROM. This may contribute to abnormal patellofemoral mechanics and a potential etiology for anterior knee pain and quadriceps weakness after TKA.

Introduction: Smartphone applications and wearable devices have shown promising outcomes to augment in-person postoperative total knee arthroplasty rehabilitation. Advantages of these technologies include patient-specific, real-time feedback and motivation which can be integrated into newer rehabilitation protocols. These technologies can be utilized in the home setting with patient directed therapy.

Methods: This brief narrative review discusses the current utilization of smartphone applications and sensors for the postoperative rehabilitation period following total knee arthroplasty. This review will discuss how they are utilized for home-based rehabilitation and the outcomes of patients who utilize them. This review specifically focuses on recovery outcomes such as adherence/satisfaction, functional improvement, and gait patterns. Outcomes are primarily descriptive, with P values noted where appropriate.

Results: This review highlights the growing evidence supporting the use of smartphone applications and wearable sensors as valuable tools in the rehabilitation process following total knee arthroplasty. Both technologies have been shown to enhance patient adherence, improve functional outcomes, mitigate pain, and provide valuable data for healthcare providers and patients. Importantly, the integration of these technologies, such as the combination of smartphone apps with wearable devices, can help improve patient outcomes when utilized in a home-based rehabilitation setting.

Conclusions: Smartphone applications and wearable devices offer enhancements in postoperative rehabilitation following total knee arthroplasty. Despite being in their infancy, randomized trials have validated their effectiveness and utility in this context. Improved adherence to postoperative care plans emerged as recurrent findings.

Total knee arthroplasty (TKA) is the gold standard for treatment of end stage knee osteoarthritis. Patellar resurfacing is an optional step in the procedure and remains a controversial topic of discussion. This retrospective study aims to assess the impact of over-resecting and under-resecting the patella during resurfacing on patient reported outcomes (PROMs) and range of motion (ROM) after surgery. 438 (92.2%) of 475 patients who underwent TKA between August 2017 and November 2019 at a single center by a single surgeon were included in the analysis. Patients were split into three study groups based on reconstructed patellar thickness; normal resection (NR) was defined as within 2 mm native thickness, over-resected (OR) was defined as ≤ -2 mm, and under-resected (UR) was defined as ≥ 2 mm. Statistical analyses included chi-squared test, mixed effect models, and cox proportional hazards models. There were 364, 41, 33 patients were in NR, OR, UR group respectively. The cohort mean age at time of surgery was 67.1 ± 9.1 and had mean length of follow-up of 2.1 ± 1.7 years with no difference among cohorts. Significant differences were found in gender (p<0.001) and BMI (p=0.0134) with UR having less males, OR having more males, and OR having lower BMI. At 6 months, the complete cohort ROM improved from 108.7 ± 14.4 degrees to 111 ± 11 degrees, objective Knee Society Score (KSS) increase from 15.4 ± 11.2 to 36.2 ± 12, functional KSS increase from 47.3 ± 18.9 to 65.6 ± 22.2, and knee injury and osteoarthritis outcome score increase from 46.1 ± 15 to 70.7 ± 15 with no significant differences among cohorts. There were no patellofemoral related complications. This study supports that while it is important to restore the anatomy in the anterior compartment of the knee, minor changes in patellar thickness from patellar resurfacing likely have minimal impact on outcomes for patients. Further studies with a larger sample size are necessary to further validate these findings.

Robotic-assisted devices help provide precise component positioning in conversion of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA). A few studies offer surgical techniques for computed tomography (CT) based robotic-assisted conversion of UKA to TKA; however, no studies to date detail this procedure utilizing a non-CT-based robotic-assisted device. This article introduces a novel technique employing a non-CT-based robotic-assisted device (ROSA Knee System, Zimmer Biomet, Warsaw, IN) for converting UKA to TKA with a focus on its efficacy in gap balancing. We present three patients (ages 46-66 years) who were evaluated for conversion of UKA to TKA for aseptic loosening, stress fracture, and progressive osteoarthritis. Each patient underwent robotic-assisted conversion to TKA. Postoperative assessments at 6 months revealed improved pain, function, and radiographic stability. Preoperative planning included biplanar long leg radiographs to determine the anatomic and mechanical axis of the leg. After arthrotomy with a standard medial parapatellar approach, infrared reflectors were pinned into the femur and tibia, followed by topographical mapping of the knee with the UKA in situ. The intraoperative software was utilized to evaluate flexion and extension balancing and plan bony resections. Then, the robotic arm guided placement of the femoral and tibial guide pins and the UKA components were removed. After bony resection of the distal femur and proximal tibia, the intraoperative software was used to reassess the extension gap, and plan posterior condylar resection to have the flexion gap match the extension gap. The use of a non-CT-based robotic-assisted device in conversion of UKA to TKA is a novel technique and a good option for surgeons familiar with robotic-assisted arthroplasty, resulting in excellent outcomes at 6 months.

Anterior cruciate ligament (ACL) tears in National Football League (NFL) players are devastating injuries that take nearly a year to recover. Players that do return to sport have worse overall performance compared to pre-ACL tear. NFL players typically play regular season games on Sunday with the next game played on the following Sunday, allowing for 6 days between games. Deviation from the usual 6-day rest week has been proposed as a potential risk for ACL tear. The main objective of this study was to evaluate the risk of decreased rest or increased rest on ACL tear rates in NFL players. ACL injury data of NFL players from the 2012 to 2013 season and 2022 to 2023 season were gathered from publicly available sources. Player demographic data, position, age at time of injury, seasons played, injury mechanism, and playing surface type were recorded. Injuries were characterized as short, normal, or long week injuries. ACL tears that occurred during the preseason, postseason, or during week 1 were excluded. Descriptive statistics were calculated to report means, ranges, and percentages. Data were analyzed to determine statistically significant differences using Fisher's exact, chi-square, or one-way analysis of variance tests. A total of 524 ACL tears were recorded in NFL players during the study window. Note that 304 ACL tears were excluded and 220 fit inclusion criteria. Twenty-four ACL tears occurred during short weeks, 68 during long weeks, and 128 during normal weeks. Players were 1.8 times more likely to tear their ACL during a long week compared to a normal week (p < 0.001), and 1.5 times more likely to tear their ACL during a short week compared to a normal week (p = 0.02). The findings from this study suggest that deviation from the normal 7-day NFL week increases the risk of an ACL tear in NFL players when increasing or decreasing rest time. Further research exploring the impact of short and long rest times on player injury risk should be conducted to prevent season-ending injuries.