Minimal clinically important change of knee flexion in people with knee osteoarthritis after non-surgical interventions using a meta-analytical approach.

BACKGROUND: Minimal clinically important change (MCIC) represents the minimum patient-perceived improvement in an outcome after treatment, in an individual or within a group over time. This study aimed to determine MCIC of knee flexion in people with knee OA after non-surgical interventions using a meta-analytical approach. METHODS: Four databases (MEDLINE, Cochrane, Web of Science and CINAHL) were searched for studies of randomised clinical trials of non-surgical interventions with intervention duration of ≤ 3 months that reported change in (Δ) (mean change between baseline and immediately after the intervention) knee flexion with Δ pain or Δ function measured using tools that have established MCIC values. The risk of bias in the included studies was assessed using version 2 of the Cochrane risk-of-bias tool for randomised trials (RoB 2). Bayesian meta-analytic models were used to determine relationships between Δ flexion with Δ pain and Δ function after non-surgical interventions and MCIC of knee flexion. RESULTS: Seventy-two studies (k = 72, n = 5174) were eligible. Meta-analyses included 140 intervention arms (k = 61, n = 4516) that reported Δ flexion with Δ pain using the visual analog scale (pain-VAS) and Δ function using the Western Ontario and McMaster Universities Osteoarthritis Index function subscale (function-WOMAC). Linear relationships between Δ pain at rest-VAS (0-100 mm) with Δ flexion were - 0.29 (- 0.44; - 0.15) (ß: posterior median (CrI: credible interval)). Relationships between Δ pain during activity VAS and Δ flexion were - 0.29 (- 0.41, - 0.18), and Δ pain-general VAS and Δ flexion were - 0.33 (- 0.42, - 0.23). The relationship between Δ function-WOMAC (out of 100) and Δ flexion was - 0.15 (- 0.25, - 0.07). Increased Δ flexion was associated with decreased Δ pain-VAS and increased Δ function-WOMAC. The point estimates for MCIC of knee flexion ranged from 3.8 to 6.4°. CONCLUSIONS: The estimated knee flexion MCIC values from this study are the first to be reported using a novel meta-analytical method. The novel meta-analytical method may be useful to estimate MCIC for other measures where anchor questions are problematic. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022323927.

Are Kinematics an Indicator of Outcome After Total Knee Arthroplasty?

BACKGROUND: A proportion of total knee arthroplasty (TKA) patients are dissatisfied postoperatively, particularly with their ability to perform higher-demand activities including deep-kneeling and step-up where kinematic parameters are more demanding. The purpose of this study was to examine the relationship between knee kinematics of step-up and deep-kneeling and patient-reported outcome measures following TKA. METHODS: Sixty-four patients were included at minimum 1-year follow-up. Participants performed a step-up and deep-kneeling task which was imaged via single-plane fluoroscopy. 3-dimensional prosthesis computer-aided design models were registered to the fluoroscopy, yielding in-vivo kinematic data. Associations between kinematics and patient-reported outcome measures, including Oxford Knee Score, American Knee Society Score, surgical satisfaction, and pain were assessed using log-transformed step-wise linear regressions. RESULTS: A higher total Oxford Knee Score was associated with more external rotation and more adduction at maximal flexion during kneeling and more external rotation and minimum flexion during step-up. Improved American Knee Society Score was associated with increased internal-external rotation during step-up. Improved surgical satisfaction was associated with greater maximum flexion and more external rotation at maximal flexion during deep-kneeling and more femoral internal rotation at terminal extension during step-up. An improved pain score was associated with greater maximum flexion and more femoral external rotation during deep-kneeling, as well as greater internal femoral rotation during step-up. CONCLUSION: The ability to move through full flexion/extension range and end-of-range rotation is important kinematic parameters that influence patient-reported outcome measures. Implant designs and postoperative rehabilitation should continue to focus on achieving these kinematic targets for enhanced outcomes after TKA.

Union and Complication Rates After Total Wrist Arthrodesis: A Systematic Review and Meta-Analysis.

PURPOSE: Total wrist arthrodesis (TWA) has been performed using various techniques. We aimed to provide pooled prevalence estimates of union and complications of TWA by technique. A secondary aim was to provide estimates of union and complication rates by treatment of the carpometacarpal joint (CMCJ) in TWA using plates. Given the widespread adoption of wrist arthrodesis plates (WAP), we hypothesized that these implants would result in higher union and lower complication rates. We also hypothesized that TWA with CMCJ arthrodesis would improve these outcomes. METHODS: Online databases including PubMed, Medline, Embase, and Cochrane were searched. Studies reporting union and/or complication rates of 10 or more TWA performed with a similar technique (analyzed as bone graft only, bone graft with minimal fixation, intramedullary, augmented intramedullary, plate, WAP, and other) were included. Studies with fewer than 10 TWA, studies reporting TWA where union or complications could not be analyzed separately, and studies without union and complication rates were excluded. Data extraction was performed independently by two English-speaking reviewers with a translator where required. Pooled prevalence estimates were made using a random-effects meta-analysis model and presented as a percent prevalence with 95% confidence and prediction intervals. RESULTS: One hundred and thirty-six studies with a total of 3,517 patients and 3,969 TWA were analyzed. No differences in union and complication prevalence were observed between TWA techniques and in TWA with different treatments of the CMCJ using plates and WAP. CONCLUSION: Using meta-analysis, we found no difference in union and complication prevalence between TWA techniques and TWA with different treatments of the CMCJ with plates and WAP. It must be acknowledged that this research included low-quality studies with high heterogeneity, and confidence in the precision of the estimates is low. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Biomechanical Performance of Total Wrist Arthrodesis Plates With and Without Arthrodesis of the Carpometacarpal Joint.

BACKGROUND: It is unknown whether total wrist arthrodesis (TWA) should be performed with or without arthrodesis of the carpometacarpal joint (CMCJ). The aim of this study is to compare CMCJ-spanning TWA plates using 3D printed wrist arthrodesis model with and without arthrodesis of the CMCJ. METHODS: Total wrist arthrodesis plates mounted to 3D printed models were tested under a 4-N bending load at 4 Hz for 50 000 cycles, increased by 15% every 10 000 cycles until failure. RESULTS: Plates with arthrodesis CMCJ were stiffer and failed at a significantly greater load and number of cycles than plates mounted to models without CMCJ arthrodesis. The Synthes stainless steel locking TWA plate performed better than the Trimed plate applied to the model without CMCJ arthrodesis and the Acumed plate applied to the model with CMCJ arthrodesis. Based on these findings, we recommend arthrodesis of the CMCJ in TWA. CONCLUSIONS: Incorporation of the CMCJ in TWA may protect against plate failure. If arthrodesis of the CMCJ is not performed, plate removal should be considered before breakage occurs. LEVEL OF EVIDENCE: IV.

Minimal important change and difference for knee osteoarthritis outcome measurement tools after non-surgical interventions: a systematic review.

OBJECTIVES: To systematically review and provide estimates of the minimal important change (MIC) and difference (MID) for outcome tools in people with knee osteoarthritis (OA) after non-surgical interventions. Design A systematic review. DATA SOURCES: MEDLINE, CINAHL, Web of Science, Scopus and Cochrane databases were searched up to 21 September 2021. ELIGIBILITY CRITERIA: We included studies that calculated MIC and MID using any calculation method including anchor, consensus and distribution methods, for any knee OA outcome tool after non-surgical interventions. DATA EXTRACTION AND SYNTHESIS: We extracted reported MIC, MID and minimum detectable change (MDC) estimates. We used quality assessment tools appropriate to the studies' methods to screen out low-quality studies. Values were combined to produce a median and range, for each method. RESULTS: Forty-eight studies were eligible (anchor-k=12, consensus-k=1 and distribution-k=35). MIC values for 13 outcome tools including Knee injury and Osteoarthritis Outcome Score (KOOS)-pain, activities of daily living (ADL), quality of life (QOL) and Western Ontario and McMaster Universities Arthritis Index (WOMAC)-function were estimated using 5 high-quality anchor studies. MID values for 23 tools including KOOS-pain, ADL, QOL and WOMAC-function, stiffness and total were estimated using 6 high-quality anchor studies. One moderate quality consensus study reported MIC for pain, function and global assessment. MDC values from distribution method estimates for 126 tools including KOOS-QOL and WOMAC-total were estimated using 38 good-to-fair-quality studies. CONCLUSION: Median MIC, MID and MDC estimates were reported for outcome tools in people with knee OA after non-surgical interventions. The results of this review clarify the current understanding of MIC, MID and MDC in the knee OA population. However, some estimates suggest considerable heterogeneity and require careful interpretation. PROSPERO REGISTRATION NUMBER: CRD42020215952.

Statistical shape modelling reveals differences in hamstring morphology between professional rugby players and sprinters.

Hamstring morphology may play an important role in understanding the aetiology of hamstring injury. Currently, the methods available to capture detailed morphological data such as muscle shape have not been utilized for the hamstring muscles. The aim of this study was to examine the utility of statistical shape modelling (SSM) for describing and comparing hamstring muscle shape in rugby and sprinting athletes. Magnetic resonance images of both thighs of nine elite male rugby players and nine track and field sprinters were analysed. Images were converted to three-dimensional models enabling generation of four statistical shape models. Principal components describing the shape variation in the cohort were derived and evaluated. Six principal components were sufficient to discriminate differences in the shape of the hamstring muscles of rugby and sprinting athletes with 89% classification accuracy. Distinct shape features distinguishing rugby players from sprinters included size, curvature and axial torsion. These data demonstrate that SSM is useful for understanding hamstring muscle shape and that meaningful variation can be identified within a small sample. This method can be used in future research to enhance the anatomical specificity of musculoskeletal modelling and to understand the relationship between hamstring shape and injury.

Evidence for key individual characteristics associated with outcomes following combined first-line interventions for knee osteoarthritis: A systematic review.

OBJECTIVE: To identify individual characteristics associated with outcomes following combined first-line interventions for knee osteoarthritis. METHODS: MEDLINE, CINAHL, Scopus, Web of Science Core Collection and the Cochrane library were searched. Studies were included if they reported an association between baseline factors and change in pain or function following combined exercise therapy, osteoarthritis education, or weight management interventions for knee osteoarthritis. Risk of bias was assessed using Quality in Prognostic Factor Studies. Data was visualised and a narrative synthesis was conducted for key factors (age, sex, BMI, comorbidity, depression, and imaging severity). RESULTS: 32 studies were included. Being female compared to male was associated with 2-3 times the odds of a positive response. Older age was associated with reduced odds of a positive response. The effect size (less than 10% reduction) is unlikely to be clinically relevant. It was difficult to conclude whether BMI, comorbidity, depression and imaging severity were associated with pain and function outcomes following a combined first-line intervention for knee osteoarthritis. Low to very low certainty evidence was found for sex, BMI, depression, comorbidity and imaging severity and moderate certainty evidence for age. Varying study methods contributed to some difficulty in drawing clear conclusions. CONCLUSIONS: This systematic review found no clear evidence to suggest factors such as age, sex, BMI, OA severity and presence of depression or comorbidities are associated with the response to first-line interventions for knee OA. Current evidence indicates that some groups of people may respond equally to first-line interventions, such as those with or without comorbidities. First-line interventions consisting of exercise therapy, education, and weight loss for people with knee OA should be recommended irrespective of sex, age, obesity, comorbidity, depression and imaging findings.

Shape modelling of the oropharynx distinguishes associations with body morphology but not whiplash-associated disorder.

Characterization of the oropharynx, a subdivision of the pharynx between the soft palate and the epiglottis, is limited to simple measurements. Structural changes in the oropharynx in whiplash-associated disorder (WAD) cohorts have been quantified using two-dimensional (2D) and three-dimensional (3D) measures but the results are inconsistent. Statistical shape modelling (SSM) may be a more useful tool for systematically comparing morphometric features between cohorts. This technique has been used to quantify the variability in boney and soft tissue structures, but has not been used to examine a hollow cavity such as the oropharynx. The primary aim of this project was to examine the utility of SSM for comparing the oropharynx between WAD cohorts and control; and WAD severity cohorts. The secondary aim was to determine whether shape is associated with sex, height, weight and neck length. Magnetic resonance (MR) T1-weighted images were obtained from healthy control (n = 20), acute WAD (n = 14) and chronic WAD (n = 14) participants aged 18-39 years. Demographic, WAD severity (neck disability index) and body morphometry data were collected from each participant. Manual segmentation of the oropharynx was undertaken by blinded researchers between the top of the soft palate and tip of the epiglottis. Digital 3D oropharynx models were constructed from the segmented images and principal component (PC) analysis was performed with the PC weights normalized to z-scores for consistency. Statistical analyses were undertaken using multivariate linear models. In the first statistical model the independent variable was group (acute WAD, chronic WAD, control); and in the second model the independent variable was WAD severity (recovered/mild, moderate/severe). The covariates for both models included height, weight, average neck length and sex. Shape models were constructed to visualize the effect of perturbing these covariates for each relevant mode. The shape model revealed five modes which explained 90% of the variance: mode 1 explained 59% of the variance and primarily described differences in isometric size of the oropharynx, including elongation; mode 2 (13%) primarily described lateral (width) and AP (depth) dimensions; mode 3 (8%) described retroglossal AP dimension; mode 4 (6%) described lateral dimensions at the retropalatal-retroglossal junction and mode 5 (4%) described the lateral dimension at the inferior retroglossal region. There was no difference in shape (mode 1 p = 0.52; mode 2 p = 0.96; mode 3 p = 0.07; mode 4 p = 0.54; mode 5 p = 0.74) between control, acute WAD and chronic WAD groups. There were no statistical differences for any mode (mode 1 p = 0.12; mode 2 p = 0.29; mode 3 p = 0.56; mode 4 p = 0.99; mode 5 p = 0.96) between recovered/mild and moderate/severe WAD. Sex was not significant in any of the models but for mode 1 there was a significant association with height (p = 0.007), mode 2 neck length (p = 0.044) and in mode 3 weight (p = 0.027). Although SSM did not detect differences between WAD cohorts, it did detect associations with body morphology indicating that it may be a useful tool for examining differences in the oropharynx.

Effects of neuromuscular gait modification strategies on indicators of knee joint load in people with medial knee osteoarthritis: A systematic review and meta-analysis.

OBJECTIVES: This systematic review aimed to determine the effects of neuromuscular gait modification strategies on indicators of medial knee joint load in people with medial knee osteoarthritis. METHODS: Databases (Embase, MEDLINE, Cochrane Central, CINAHL and PubMed) were searched for studies of gait interventions aimed at reducing medial knee joint load indicators for adults with medial knee osteoarthritis. Studies evaluating gait aids or orthoses were excluded. Hedges' g effect sizes (ES) before and after gait retraining were estimated for inclusion in quality-adjusted meta-analysis models. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: Seventeen studies (k = 17; n = 362) included two randomised placebo-controlled trials (RCT), four randomised cross-over trials, two case studies and nine cohort studies. The studies consisted of gait strategies of ipsilateral trunk lean (k = 4, n = 73), toe-out (k = 6, n = 104), toe-in (k = 5, n = 89), medial knee thrust (k = 3, n = 61), medial weight transfer at the foot (k = 1, n = 10), wider steps (k = 1, n = 15) and external knee adduction moment (KAM) biofeedback (k = 3, n = 84). Meta-analyses found that ipsilateral trunk lean reduced early stance peak KAM (KAM1, ES and 95%CI: -0.67, -1.01 to -0.33) with a dose-response effect and reduced KAM impulse (-0.37, -0.70 to -0.04) immediately after single-session training. Toe-out had no effect on KAM1 but reduced late stance peak KAM (KAM2; -0.42, -0.73 to -0.11) immediately post-training for single-session, 10 or 16-week interventions. Toe-in reduced KAM1 (-0.51, -0.81 to -0.20) and increased KAM2 (0.44, 0.04 to 0.85) immediately post-training for single-session to 6-week interventions. Visual, verbal and haptic feedback was used to train gait strategies. Certainty of evidence was very-low to low according to the GRADE approach. CONCLUSION: Very-low to low certainty of evidence suggests that there is a potential that ipsilateral trunk lean, toe-out, and toe-in to be clinically helpful to reduce indicators of medial knee joint load. There is yet little evidence for interventions over several weeks.

Serious cycling-related fractures in on and off-road accidents: A retrospective analysis in the Australian Capital Territory region.

Cycling is an increasingly popular activity which is widely supported by health advocates. In the last year, more than a third of Australians used a bike [1]. While road cycling remains popular, participation in off-road recreational cycling, including mountain biking, bicycle moto cross (BMX) riding, and outdoor leisure cycling, is increasing and this is associated with an increase in the number and cost of cycling injuries [2-5]. The aim of this study was to describe and compare contemporary patterns of cycling fracture requiring hospitalisation as a function of cycling mode in the Australian Capital Territory region. This retrospective analysis of cycling-related-fracture hospitalisations in the ACT region described data recorded between July 2012 and December 2019. Logistic regression models were used to calculate probabilities of sustaining a fracture at different sites for each of the cycling modes (on-road, mountain, BMX, leisure, unspecified). These likelihoods were then compared against the on-road fracture profile. Cycling-related-fracture hospitalisations increased by 32% in the seven years analysed. Of all fracture admissions, 442 (33%) were on-road, 658 (49%) off-road, and 242 (18%) unknown. The majority were male (79%), median age 37 (IQR 16, 52). Median length of stay was two days. The number of fractures per admission ranged from one to thirteen with a median of one. Wrist, clavicle, ribs, and skull were the four most frequent fracture sites for all cycling modes. Fracture profiles of on- and off-road accidents were similar, with the exception of wrist fractures which were more likely in off-road (OR 1.96, p < 0.01) and unspecified cycling accidents (OR 5.07, p < 0.01). Skull fractures comprised 19% of all BMX-related fractures. More than half of all fracture-related admissions required surgery. With increasing support for sustainable and healthy transport and recreation activities, the fracture profiles of different cycling modes must first be assessed in order to inform strategies to reduce and manage this injury burden.

What's old is best again Is anterior plating best for fixation of type-C pelvic fractures? A systematic review and meta-analysis.

BACKGROUND: Type-C pelvic fractures are a rare but potentially fatal injury that often leads to poor outcomes, despite surgical fixation. Many fixation methods are used but the optimal method remains contentious, with failure and complications common. This study compared outcomes for each fixation method. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A search of studies which reported on outcomes after surgically treated type-C pelvic fractures was undertaken. Data retrieved included fixation method, length of follow up, surgical revision, and complications rates (hardware breakage, post-operative outcomes, screw mal-positioning, screw loosening, loss of reduction and infection). Study quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS). Pooled revision, outcome and complication rates were calculated using a quality-adjusted model in MetaXL 5.3. RESULTS: Fifty-two studies met the inclusion criteria representing 1567 patients and 7 fixation methods. The meta-analyses demonstrated high rates of 'less-than-good' outcomes for most fixation methods, with a higher rate for bilateral injuries (overall 23%; unilateral 21% v bilateral 41%). The mean pooled rate for surgical revision rate was 4%, hardware breakage 3%, screw mal-positioning 2%, screw loosening 3%, loss of reduction 5% and infection 4%. Each fixation method had different performance profiles; however, anterior plating outperformed all other fixation methods for patient outcomes, with a 'less-than-good' rate of just 7% vs the pooled mean of 23% and demonstrated at or below pooled mean rates for all complications except revision which was 5%. CONCLUSIONS: Post-operative outcomes for surgically treated type-C pelvic fractures revealed a 'less-than-good' pooled outcome rate of 23% and a revision rate of 4%. Anterior plates outperformed most other systems particularly for patient reported outcomes. Pooled revision, patient-reported outcome and complication rates for type-C pelvic fractures have not previously been reported and these data provide a benchmark for practice and future research.

Total wrist arthrodesis with and without arthrodesis of the carpoMetacarpal joint (WAWWAM): study protocol.

BACKGROUND: It is controversial whether or not the carpometacarpal joint (CMCJ) should be included in total wrist arthrodesis (TWA). Complications commonly occur at this site and studies examining its inclusion and exclusion are conflicting. A randomised clinical trial comparing wrist arthrodesis with CMCJ arthrodesis and spanning plate to wrist arthrodesis with CMCJ preservation and non-CMCJ spanning plate has not been performed. METHOD: A single centre randomised clinical trial including 120 adults with end-stage isolated wrist arthritis will be performed to compare TWA with and without the CMCJ included in the arthrodesis. The primary outcome is complications in the first post-operative year. Secondary outcomes are Disabilities of the Arm, Shoulder and Hand (DASH) score, Patient Rated Wrist Evaluation (PRWE) and grip strength measured at 1, 2 and 5 years. Late complications, return to work and satisfaction will also be recorded. DISCUSSION: It is unknown whether the CMCJ should be included in TWA. This trial will contribute to an improved understanding of optimal management of the CMCJ in total wrist arthrodesis. TRIAL REGISTRATION: This trial was prospectively registered with the Australia New Zealand Clinical Trials Registry with identifying number ACTRN12621000169842 on the 16th February 2021. WHO: U1111-12626523. ANZCTR: ACTRN12621000169842.

Individuals with gluteal tendon repair display similar hip biomechanics to those of a healthy cohort during a sit-to-stand task.

BACKGROUND: Gluteal-tendon repair (GTR) is reported to be effective for relieving pain and improving clinical function in patients with gluteal-tendon tears. The sit-to-stand (STS) task is an important activity of daily living and is often used to assess functional capacity in clinical populations. Understanding if and how STS performance is altered in individuals with gluteal tendon repair may be an effective marker of GTR outcomes as well as a possible therapeutic target for post-operative rehabilitation. RESEARCH QUESTION: Do biomechanical parameters during STS differ between age- and sex-matched participants with and without gluteal-tendon repair? METHODS: 27 participants with a GTR and 29 healthy participants performed the STS task. Data were acquired using the three-dimensional motion capture system and forceplates. Outcomes of interest were task duration, rate of force development, trunk, pelvis, and hip joint angles, moments and powers. Differences were assessed using Generalised linear multivariate models and statistical parametric mapping. RESULTS: GTR patients performed the STS movement significantly slower (1.4+/- 0.40 s) compared to controls (1.1+/ -0.2 s) with a significantly lower rate of force development (35.1+/- 5.7 N/kg/ms vs 30.3+/- 8.5 N/kg/ms). There were no group differences for hip, pelvis, or trunk angle over the movement cycle or for maximal or minimal values. Furthermore, there were no significant differences detected in hip joint kinetics. However, there appeared to be substantial between-subject variability indicating different patient-specific movements patterns. SIGNIFICANCE: Individuals with a GTR performed the STS task about 20 % slower than healthy controls with a lower rate of force development. The individual variations indicate that participants likely employed different movement strategies to achieve STS. While the lack of differences between groups could suggest that GTR helps restore function and corrects the proposed underlying aetiology, it is possible that the STS task was not sufficiently challenging to discriminate between groups.

A critical analysis of the 8th edition TNM staging for head and neck cutaneous squamous cell carcinoma with lymph node metastases and comparison to N1S3 stage and ITEM risk score: A multicenter study.

BACKGROUND AND OBJECTIVES: We performed a critical analysis of the 8th edition American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) with nodal metastases and compared the performance to the N1S3 and ITEM systems. METHODS: Multicenter study of 990 patients with metastatic HNcSCC treated with curative intent. The end points of interest were disease-specific (DSS) and overall survival (OS). Model fit was evaluated using Harrell's Concordance Index (C-index), proportion of variation explained (PVE), Akaike information criterion, and Bayesian information criterion. RESULTS: N1S3 and ITEM demonstrated good distribution into risk categories in contrast to the AJCC system, which classified the majority (90.6%) of patients as N2-3 and Stage IV due to the high rate of extranodal extension. The N2c and N3a categories appeared redundant. There was considerable discordance between systems in risk allocation on an individual patient basis. N1S3 was the best performed (DSS: C-index 0.62, PVE 10.9%; OS: C-index 0.59, PVE 4.5%), albeit with relatively poor predictive value. CONCLUSIONS: The AJCC N category and tumor node metastasis stage have poor patient distribution and predictive performance in HNcSCC. The AJCC stage, N1S3, and ITEM score all provide limited prognostic information based on objective measures highlighting the need to develop a staging system specific to HNcSCC.

Influence of component design on in vivo tibiofemoral contact patterns during kneeling after total knee arthroplasty: a systematic review and meta-analysis.

PURPOSE: Modern TKR prostheses are designed to restore healthy kinematics including high flexion. Kneeling is a demanding high-flexion activity. There have been many studies of kneeling kinematics using a plethora of implant designs but no comprehensive comparisons. Visualisation of contact patterns allows for quantification and comparison of knee kinematics. The aim of this systematic review was to determine whether there are any differences in the kinematics of kneeling as a function of TKR design. METHODS: A search of the published literature identified 26 articles which were assessed for methodologic quality using the MINORS instrument. Contact patterns for different implant designs were compared at 90° and maximal flexion using quality-effects meta-analysis models. RESULTS: Twenty-five different implants using six designs were reported. Most of the included studies had small-sample sizes, were non-consecutive, and did not have a direct comparison group. Only posterior-stabilised fixed-bearing and cruciate-retaining fixed-bearing designs had data for more than 200 participants. Meta-analyses revealed that bicruciate-stabilised fixed-bearing designs appeared to achieve more flexion and the cruciate-retaining rotating-platform design achieved the least, but both included single studies only. All designs demonstrated posterior-femoral translation and external rotation in kneeling, but posterior-stabilised designs were more posterior at maximal flexion when compared to cruciate retaining. However, the heterogeneity of the mean estimates was substantial, and therefore, firm conclusions about relative behaviour cannot be drawn. CONCLUSION: The high heterogeneity may be due to a combination of variability in the kneeling activity and variations in implant geometry within each design category. There remains a need for a high-quality prospective comparative studies to directly compare designs using a common method. LEVEL OF EVIDENCE: Systematic review and meta-analysis Level IV.

The influence of total knee arthroplasty design on kneeling kinematics: a prospective randomized clinical trial.

AIMS: Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs. METHODS: In total, 68 patients were randomized to either a posterior stabilized (PS-FB), cruciate-retaining (CR-FB), or rotating platform (CR-RP) design. Of these patients, 64 completed a minimum one year follow-up. Patients completed full-flexion kneeling while being imaged using single-plane fluoroscopy. Kinematics were calculated by registering the 3D implant models onto 2D-dynamic fluoroscopic images and exported for analysis. RESULTS: CR-FB designs had significantly lower maximal flexion (mean 116° (SD 2.1°)) compared to CR-RP (123° (SD 1.6°)) and PS-FB (125° (SD 2.1°)). The PS-FB design displayed a more posteriorly positioned femur throughout flexion. Furthermore, the CR-RP femur was more externally rotated throughout kneeling. Finally, individual patient kinematics showed high degrees of variability within all designs. CONCLUSION: The increased maximal flexion found in the PS-FB and CR-RP designs were likely achieved in different ways. The PS-FB design uses a cam-post to hold the femur more posteriorly preventing posterior impingement. The external rotation within the CR-RP design was surprising and hasn't previously been reported. It is likely due to the polyethylene bearing being decoupled from flexion. The findings of this study provide insights into the function of different knee arthroplasty designs in the context during deep kneeling and provide clinicians with a more kinematically informed choice for implant selection and may allow improved management of patients' functional expectations. Cite this article: Bone Joint J 2021;103-B(1):105-112.

People after gluteal tendon repair have gait characteristics which are similar to those of a healthy cohort.

BACKGROUND: Gluteal-tendon repair is reported to be effective for relieving pain and improving function in patients with gluteal-tendon tears. However, post-operative three-dimensional gait analysis has never been conducted in gluteal-tendon repair patients. Thus, our primary aim was to investigate how biomechanical gait parameters differ between age- and sex-matched participants with and without gluteal-tendon repair. METHODS: Vicon motion analysis technology was used to measure gait characteristics of 25 gluteal-tendon repair participants and 29 matched healthy comparison group participants. A generalised linear multivariate model was used to compare external hip-adduction moment, range of movement in hip adduction and internal rotation, pelvic obliquity, trunk lean, stride length and velocity of both cohorts throughout stance. FINDINGS: There were no differences between the groups in external hip adduction moment, pelvic obliquity and range of movement in hip adduction and internal rotation. Gluteal-tendon repair participants had a shorter stride length (P = 0.031) and reduced walking velocity (P = 0.015). Ipsilateral trunk lean was reduced in gluteal-tendon repair participants at the first-peak external hip-adduction moment (P = 0.016), mid-stance minimum external hip-adduction moment (P = 0.029) and second-peak external hip-adduction moment (P = 0.006). INTERPRETATION: There were no differences between the gluteal-tendon repair and comparison groups for external hip-adduction moment and pelvic obliquity. This suggests that gluteal-tendon repair may restore hip control in stance. Slower walking speed, reduced stride length and decreased ipsilateral trunk lean may reflect persistence of pre-operatively developed gait adaptations. Future studies of gait biomechanics before and after gluteal-tendon repair would be needed to substantiate this theory.

The American Joint Committee on Cancer staging for metastatic head and neck cutaneous squamous cell carcinoma: A multi-institutional study of within-stage heterogeneity and impact on prognostic performance.

BACKGROUND: The American Joint Committee on Cancer (AJCC) staging for head and neck cutaneous squamous cell carcinoma (HNcSCC) stratifies risk poorly. We hypothesized that this results from prognostic heterogeneity within N and TNM groups. METHODS: Retrospective analysis of disease-specific survival (DSS) in a multicenter study of 1146 patients with nodal metastases from HNcSCC. RESULTS: The majority of patients were classified as pN2a or pN3b (83.1%) and TNM stage IV (90.6%). On multivariate analysis, there was statistically significant prognostic heterogeneity within these groups based on the number and size of nodal metastases, immunosuppression, and perineural invasion. When stage IV patients were categorized into low, moderate, and high-risk groups based on adverse features, there was wide variation in prognosis with 5-year DSS ranging from 90% to 60% (P < .001). CONCLUSIONS: The AJCC staging system stratifies risk poorly in HNcSCC due to significant prognostic heterogeneity within pN2a, pN3b, and stage IV groups.

Number of nodal metastases and the American Joint Committee on cancer staging of head and neck cutaneous squamous cell carcinoma: A multicenter study.

OBJECTIVES: We aimed to determine if the number of nodal metastases is an independent predictor of survival in HNcSCC, whether it provides additional prognostic information to the AJCC N and TNM stage and identify optimal cut-points for risk stratification. MATERIALS AND METHODS: Retrospective multi-institutional cohort study of patients with parotid and/or cervical nodal metastases from HNcSCC treated with curative intent by surgery ±â€¯adjuvant therapy. The impact of number of nodal metastases on disease-specific and overall survival was assessed using multivariate Cox regression. Optimal cut-points for prognostic discrimination modelled using the AIC, BIC, C-index and PVE. RESULTS: The study cohort included 1128 patients, with 962 (85.3%) males, median age of 72.9 years (range: 18-100 years) and median follow-up 3.4 years. Adjuvant radiotherapy was administered to 946 (83.9%) patients. Based on objective measures of model performance, number of nodal metastases was classified as 1-2 (N = 816), 3-4 (N = 162) and ≥5 (N = 150) nodes. In multivariate analyses, the risk of disease-specific mortality progressively increased with 3-4 nodes (HR, 1.58; 95% CI: 1.03-2.42; p = 0.036) and ≥5 nodes (HR, 2.91; 95% CI: 1.99-4.25; p < 0.001) with similar results for all-cause mortality. This simple categorical variable provided superior prognostic information to the TNM stage. CONCLUSION: Increasing number of nodal metastases is an independent predictor of mortality in HNcSCC, with categorization as 1-2, 3-4 and ≥5 nodes optimizing risk stratification and providing superior prognostic information to TNM stage. These findings may aid in the development of future staging systems as well as identification of high-risk patients in clinical trials.