Functional Assessment

Clinical evaluation of knee ROM, strength, and proprioception to determine return-to-sport readiness and identify deficits predisposing patients to re-injury.

Overview

The functional assessment score serves as a simple measure of physical function and a means of quantifying an individual's treatment response to joint replacement surgery [1]. Objective characterization of muscle function provides baseline and outcome measures that may quantify specific strength deficits amendable with tailored rehabilitation programs and monitor effectiveness of treatments [3]. Physical outcome measures are being changed for the use of patient reported outcomes, and range of motion and strength are not as reliable measures as one would think [65].

Normal KOOS and WOMAC values in a healthy population can be used in daily practice as a reference to assess functional outcomes after a surgical procedure [16]. Therapists may use information on dexterity assessments to choose the best assessment instrument to evaluate a patient's recovery of function over time [13]. The PSFS provides a method to assess individual functional limitations, can be completed in a shorter period of time than the DASH, and was more acceptable to the patients than the DASH [64].

Floor/ceiling effects necessitate complementary outcome measures for comprehensive functional assessment [9]. Not all patients performed well on functional testing at 4 months post-operatively following isolated meniscus repair, suggesting a role for functional testing to identify patients who may need further physical therapy prior to a return to sports [11]. Functional recovery continues beyond 6 months and up to 2 years, questioning the pertinence of studying functional differences at only 12 weeks follow-up [58]. The use of high-fidelity functional assessment tools that can be integrated into clinical workflow, such as the MICS, should permit PROM/functional performance comparisons in large populations [5].

Anatomy & Pathophysiology

Osseous and Alignment Dynamics

Knee alignment is dynamic, varying between individuals and changing with different postures [51]. During normal gait, motion patterns are consistent across individuals, with differences noted only in the amount of flexion during the stance phase between men and women [56]. In patients with knee osteoarthritis, biomechanical characteristics include malalignment, muscular dysfunction, proprioception deficits, laxity, and abnormal joint loading [26].

Ligamentous and Soft Tissue Mechanics

The superficial medial collateral ligament (MCL) length critically influences stability; altering its normal length results in measurable changes in knee kinematics and stability [41]. Finite element analysis models effectively analyze the biomechanical functions of the superficial and deep layers of the MCL [50]. Neuromuscular electrical stimulation appears safe for knee joint biomechanics, with no pathological changes in knee function observed in professional soccer players returning to sport after ACL reconstruction [59].

Kinematics and Biomechanical Function

ACL Reconstruction Outcomes: Biomechanical Deficits: Poor knee function after ACL reconstruction is associated with attenuated landing force and knee flexion moment during running [24]. Patients with lower levels of knee function demonstrate hop-landing biomechanics previously associated with early patellofemoral osteoarthritis [52]. Conversely, greater knee flexion excursion and moment in hopping are associated with better knee function following anterior cruciate ligament reconstruction [52]. Surgical Efficacy: Anatomic single- and double-bundle ACL reconstruction procedures are similarly effective for restoring near-normal dynamic knee function, although neither fully restores normal knee kinematics [28]. Knee biomechanics in the reconstructed leg are altered mainly in the sagittal plane during side-cutting compared with the contralateral leg [43]. Fatigue and Gender Effects: Knee kinematics are altered post-fatigue while performing a crossover task, with participants having diminished knee control at initial contact after 50% fatigue [61]. Boys demonstrate greater knee frontal moments than girls during the impact phase of cutting maneuvers, despite age-related increases in girls [53].

Total Knee Arthroplasty (TKA) Kinematics: Knee motion kinematic patterns observed during standing up from and sitting down on a chair in posterior-stabilized TKA are not similar to normal knee kinematics and derive from the unique design of the Bi-Surface PS prosthesis [35]. The kinematics of normal knees during high flexion are variable according to the specific activity [48].

Assessment and Controls: Knee biomechanical markers are associated with patient-reported knee function to a greater extent than X-ray grading, with both providing complementary information in the assessment of osteoarthritis patients [55]. The contralateral knee can be used as a reliable normal kinematic control in the context of cruciate ligament deficiency [63].

Bracing and External Interventions

No braces are currently available with biomechanical evidence that satisfies the requirements of applying correct anatomic joint forces that vary with the knee flexion angle [46]. A treatment applying a biomechanical device to the feet of patients with knee osteoarthritis results in reduced pain and improved function [57].

General Anatomy

The chapter provides a comprehensive review of the anatomy and biomechanics of the knee, including bone structure, vascular and nerve supply, ligamentous organization, and functional mechanics relevant to stability and injury [62].

Classification

Functional assessment scores serve as a simple measure of physical function and a means of quantifying an individual's treatment response to joint replacement surgery [1]. Functional scores and radiological outcomes were improved following surgical treatment of patellar instability in children with Down syndrome [2]. Functional outcome is better predicted by functional tests and validated questionnaires, with proprioception and neuromuscular control playing a key role [4]. High-fidelity functional assessment tools, such as the marker-less image capture system (MICS), can be integrated into clinical workflow to permit patient-reported outcome (PROM) and functional performance comparisons in large populations [5]. Normal KOOS and WOMAC values in a healthy population can be used in daily practice as a reference to assess functional outcomes after a surgical procedure [16]. Methods for evaluating muscular performance require accurate terminology and objective, quantitative tests to replace inaccurate or misleading traditional methods [17]. Shoulder physical functions were mapped to American Shoulder and Elbow Surgeons and Patient-Reported Outcomes Measurement Information System scores [102]. The ICF HandA provides a consensus on outcome measures and instruments to systematically assess function in patients with hand injuries and disorders [103].

Patellofemoral Pain Classification: A classification system reflecting a consensus reached by the European Rehabilitation Panel was introduced to help clinicians identify the cause(s) of patellofemoral pain and select the most appropriate non-operative treatment [75]. Guidelines recommend using reproduction of retropatellar pain during squatting and other functional activities for diagnosis and propose a classification system based on predominant impairments for patellofemoral pain [100].

Recurrent Patellar Subluxation Classification: A novel classification system for patients with recurrent patellar subluxation and excessive femoral torsion based on segmental femoral torsion analysis was established [99].

Acute Muscle Strain Classification: A proposed new classification system for acute muscle strain injuries must be applied to a variety of muscle architectures and locations to determine its utility, with additional studies needed prior to general acceptance [32].

Rotator Cuff Assessment Criteria: Twenty-six different criteria described by multiple classification systems have been identified for the magnetic resonance assessment of rotator cuff after repair [49].

Other Considerations: Further research is needed to develop updated classification systems for the posterolateral corner of the knee and to better understand the role of non-invasive and minimally invasive approaches along with standardized rehabilitation protocols [54]. Demographic variables such as advanced age, low family income, and multiple medical conditions significantly affect scores in numerous scoring systems devised to evaluate patients with knee symptoms [97].

Clinical Presentation

Functional assessment scores provide a simple measure of physical function and quantify an individual's treatment response to joint replacement surgery [1]. Functional outcome is better predicted by functional tests and validated questionnaires [4]. Proprioception and neuromuscular control play a key role in predicting functional outcome [4]. Objective characterization of muscle function provides baseline and outcome measures to quantify specific strength deficits amendable with tailored rehabilitation programs [3]. Objective characterization of muscle function monitors the effectiveness of treatments [3].

High-fidelity functional assessment tools, such as marker-less image capture systems, can be integrated into clinical workflow to permit patient-reported outcome (PROM) and functional performance comparisons in large populations [5]. Kinematic scores add information to regular outcome tools and offer an effective way to measure functional performance [12]. Kinematic scores have the potential to detect early treatment failures [12]. Floor and ceiling effects in the Marx Activity Rating Scale necessitate complementary outcome measures for comprehensive functional assessment [9].

Clinical impairment measures do not appear to be related to measured functional ability in anterior cruciate ligament reconstruction patients [7]. Traditional functional tests, such as strength and hop tests, are not able to accurately identify patients who continue to show functional performance deficits at return to sport after anterior cruciate ligament reconstruction [8]. Functional testing following isolated meniscus repair helps identify patients who need additional physical therapy prior to return to activity [11]. Not all patients performed well on functional testing at 4 months post-operatively following isolated meniscus repair [11].

Functional scores and radiological outcomes improve following surgical treatment of patellar instability in children with Down syndrome [2]. A thorough physical examination and diagnostic work-up are essential to proper management of the adult paralytic foot [25]. Understanding relevant functional anatomy is essential to proper management of the adult paralytic foot [25]. Incorporating neurodynamic assessments into the clinical evaluation of patellofemoral pain syndrome (PFPS) patients facilitates more effective management [27].

Further evaluation is needed to determine the clinical relevance of proprioception deficits between osteoarthritic and age-matched unaffected knees [30]. Clinically meaningful outcomes after primary arthroscopic partial meniscectomy were established by patient self-assessment [31]. Successful management of patellofemoral pain is rooted in the detection of underlying impairments and functional limitations found during a thorough evaluation [33]. Interventions for patellofemoral pain should be designed to target individually identified deficits [33].

Findings from systematic reviews on gluteus medius muscle function should be considered when assessing and managing patients with low back pain [34]. Functional knee tests were significant outcome measurements and should be reported separately [36]. A combination of assessments provides both physical measures of recovery and measures of perceived level of function in carpal tunnel release outcomes [39]. Severe pain with limited range of motion is a reliable clinical sign [40].

General evaluation of the hip patient covers symptom localization, physical examination maneuvers, and diagnostic categories including Femoroacetabular impingement, Osteoarthritis, Inflammatory arthritis, and Osteonecrosis [37]. General evaluation of the hip patient highlights key preoperative considerations and treatment principles [37].

Investigations

Plain radiography: Standardized MRI-based thresholds for functional patella alta relative to the tibia and trochlea should improve conventional assessment using the Caton–Deschamps index, which was originally developed for true lateral radiographs [70]. Caution should be exercised when using plain radiographs for preoperative planning or postoperative evaluation due to the effect of lower limb rotation on radiographic measurements of femoral and tibial joint line obliquity [94]. Presentation factors that increase the likelihood of a diagnostic X-ray for knee pain include pain for longer than 6 months, the presence of medial or diffuse pain, and mechanical symptoms [93].

MRI: Magnetic resonance imaging is recommended as a routine imaging method for accurate diagnosis and appropriate treatment of bone stress injuries causing exercise-induced knee pain [66]. Advanced imaging, such as MRI, should not replace history and physical examination but can be used as necessary [10]. Preoperative MRI scanning identifies patients with more advanced degenerative joint disease than suggested by clinical assessment and plain radiographs [68]. In symptomatic cases with inconspicuous conventional MRI imaging, additional MRI imaging in the axial plane with 20° of knee flexion could be beneficial and useful in clinical daily routine [76]. An MRI shorthand tool is a simple and efficient means of assessing the skeletal maturity of adolescent patients with a knee MRI scan [92].

MRI Findings and Outcomes: Short-term clinical and MRI outcomes for second-generation chondrocyte implantation for knee cartilage lesions are promising [6]. Functional and radiological results after limited saucerization of a discoid lateral meniscus were superior in pediatric patients [47]. Patients with more severe imaging lesions of knee osteoarthritis tend to have poorer range of motion [81]. MRI-based ACL graft maturity does not predict clinical and functional outcomes during the first year after ACL reconstruction [82]. MRI interpretations demonstrate improved clinical outcome measures following therapeutic intervention with Pentosan Polysulphate Sodium in an osteoarthritic patient with concurrent resolution of subchondral Bone Marrow Edema Lesion and joint effusion [90]. Dynamic MRI technique for assessing knee patellar tracking appears applicable but requires further adequately powered studies to determine clinical relevance and address study limitations [89]. MRI findings of varying injury grades did not significantly correlate with final functional outcomes in a non-athletic population with calf muscle strain injuries [67]. Protective clinical parameters and quantitative and semi-quantitative MR-imaging parameters are associated with maintaining radiographically normal knee joints in an older population over 8 years [86].

Other Considerations: Functional scores and radiological outcomes were improved following surgical treatment of patellar instability in children with Down syndrome [2]. Radiographic severity of arthritic changes can predict knee-specific functional improvement following total knee arthroplasty, but cannot predict the extent of global functional improvement [83]. There were no significant differences in clinical or functional outcomes between modified kinematic and mechanical alignment in total knee arthroplasty despite distinct radiological alignment outcomes after 1-year follow-up [85]. A low radiological severity of osteoarthritis pre-operatively is associated with a lower functional level after total knee replacement [95]. A low radiological severity of osteoarthritis was not associated with pain 12 months postoperatively after total knee replacement [95].

Treatment

Functional Assessment and Monitoring

Functional assessment scores provide a simple measure of physical function and quantify an individual's treatment response to joint replacement surgery [1]. Objective characterization of muscle function provides baseline and outcome measures to quantify specific strength deficits amendable with tailored rehabilitation programs and monitor treatment effectiveness [3]. Functional outcome is better predicted by functional tests and validated questionnaires, with proprioception and neuromuscular control playing a key role [4]. Kinematic scores add information to regular outcome tools and offer an effective way to measure functional performance, with the potential to detect early treatment failures [12]. Therapists may use dexterity assessment information to choose the best assessment instrument to evaluate a patient's recovery of function over time [13]. Objective functional results, subjective outcomes, and measures of static medial stability are satisfactory in the short term following anatomic medial knee reconstruction [14]. Cross-education effects on shoulder rotator muscle strength and function after shoulder stabilization surgery have no effect on functional outcomes [15]. Methods for evaluating muscular performance require accurate terminology and objective, quantitative tests to replace inaccurate or misleading traditional methods [17]. Assessing the efficacy of optimal strength training has the potential for immediate and vital clinical impact [38]. Participants in the Osteoarthritis physical activity care pathway (OA-PCP) reported clinically relevant improvements in pain and function [42]. One year after multidisciplinary treatment for chronic pain after total knee arthroplasty, a clinically relevant improvement was shown in terms of function, pain, self-efficacy, and quality of life [44]. The Minnesota Activity Scale provides standardized questions to comprehensively assess return to activity as a marker of treatment effectiveness [45]. A careful evaluation of upper limb functional capacity and self-reported disability is warranted to provide advice regarding exercises or adjustments at work for patients with osteoarthritis of the hands [69]. Further testing of the IKDC guidelines is necessary to determine if they are capable of detecting a change in patients over time following treatment and/or surgery of the knee [78]. The study on functional evaluation of the pes anserinus transfer did not establish when the muscles changed their phase of activity or address the indications for the procedure [79]. Although flexion range deteriorates postoperatively due to reformation of adhesions after quadricepsplasty, this loss is statistically non-significant regarding overall functional outcome scores [104]. Functional scores and radiological outcomes improved following surgical treatment of patellar instability in children with Down syndrome [2].

Non-Operative

Physical therapy management of osteochondritis dissecans can incorporate a full spectrum of conservative, nonoperative, and postoperative care [87]. A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months before considering other treatment options [88]. Favorable outcomes can occur after both operative and nonoperative management approaches with the use of progressive criterion-based rehabilitation for anterior cruciate ligament injuries [91]. Nonoperative treatment should not be extended more than 1 year from injury for isolated anterolateral bundle reconstructions of the posterior cruciate ligament [96]. Non-operative physical modalities of treatment are of benefit when treating osteoarthritis of the knee, though much of the literature reviewed evaluates studies with follow-up of less than six months [98]. Nonoperative management of adolescent mid-shaft clavicle fractures results in excellent functional outcomes at long-term follow-up [105]. If patients with meniscectomy present with negative predictor factors, nonoperative management should be continued until total knee replacement is unavoidable [106]. Nonoperative treatment with a healing phase and a strict rehabilitation plan results in a functional, efficient reattachment of the tendon and allows unrestricted return to play for complete proximal adductor avulsion in high-performance athletes [107]. Future directions for hamstring muscle injury should prioritize injury prevention, early diagnosis, and targeted interventions that combine non-surgical and minimally invasive orthobiological approaches [108].

Operative

Indications: If nonoperative treatment fails, bilateral subluxating popliteus tendons can be successfully treated with surgical stabilization [77]. Surgical indication for undersurface and full-thickness gluteus medius tears of the hip is in symptomatic patients having failed a primary nonoperative protocol [73]. Surgical release was effective in a case where nonoperative treatment failed for an issue involving the innervation supply of the vastus medialis muscle [101].

Complications

Infection (PJI): The evidence base provided does not contain specific data regarding infection rates, risk factors, or management strategies for periprosthetic joint infection.

Aseptic loosening: No specific data on aseptic loosening incidence or management is provided in the current evidence set.

Instability: No specific data on instability rates or management is provided in the current evidence set.

Periprosthetic fracture: No specific data on periprosthetic fracture incidence or management is provided in the current evidence set.

Thromboembolism: No specific data on thromboembolic events is provided in the current evidence set.

Patellar / Extensor-mechanism: At short-term to midterm follow-up, 63% of patients successfully returned to military function with a low rate of perioperative complications (8%) after tibial tubercle osteotomy for patellar chondral pathology [80]. Further studies are warranted to assess the long-term outcomes of patellofemoral arthroplasty (PFA) [84].

Stiffness / Arthrofibrosis: No specific data on stiffness or arthrofibrosis rates is provided in the current evidence set.

Nerve palsy: No specific data on nerve palsy incidence is provided in the current evidence set.

Wound complications: No specific data on wound complications is provided in the current evidence set.

Polyethylene wear: No specific data on polyethylene wear rates is provided in the current evidence set.

Other Considerations: A structured preoperative exercise program resulted in better postoperative functional outcomes at the long term [18]. Minimally invasive Oxford unicompartmental knee arthroplasty ensures excellent functional outcome and high survivorship in the long term [20]. Oxford UKA of the medial compartment ensures good long-term survivorship with an excellent functional outcome [20]. An intraoperative load sensor did not improve the early postoperative results of posterior-stabilized TKA for osteoarthritis with varus deformities [21]. A long-term followup study with a large cohort is required to determine the impact of an intraoperative load sensor on posterior-stabilized TKA for osteoarthritis with varus deformities [21]. The positive results observed in all domains of assessment and the small revision rate demonstrated an effective functioning of the FIRST® prosthesis during the ten-year follow-up period [23]. One in 2 patients reported acceptable long-term knee function after anterior cruciate ligament reconstruction, but no risk factor for poorer subjective knee function was identified [109]. Five years after ACL reconstruction, thigh muscle adaptation depended on graft choice and carried meaningful functional consequences [110]. In the absence of serious complications, most patients had improvement in most components of function after McKee-Farrar total hip replacement, with greater gains occurring during the first six months and lesser but continued gains between the sixth and twenty-fourth postoperative months [111]. The lateral hamstring transfer procedure appears to be both effective and relatively free of late complications, with decreased knee-flexion deformity and improved walking function achieved in 91 per cent of patients [112]. Children had good objective physical function 1 and 3 years after ACL reconstruction [113]. At an average 9 years after operative fixation of an osteochondritis dissecans loose body, patients did not have symptoms of osteoarthritis pain and had normal function in activities of daily life, but reported significantly lower knee-related quality of life [115].

Recovery

Light activity (weeks): Evidence does not specify a precise week range for light activity or driving. However, recovery trajectories over six weeks in patients selected for high-intensity physiotherapy after total knee arthroplasty can distinguish outcome after one year [118].

Full activity (months): Four distinct 5-year trajectories of patient-reported knee function emerge after following the Delaware-Oslo ACL Cohort Treatment Algorithm, with 88% of patients following Moderate and High trajectories characterized by good improvement and high scores [117]. Anatomic medial knee reconstruction restores stability and function with satisfactory objective functional results, subjective outcomes, and static medial stability measures at minimum 2-year follow-up [14]. Both open kinetic chain and closed kinetic chain programs lead to an equal long-term good functional outcome in patellofemoral pain [119].

Complete recovery / outcome plateau (months): Long-term follow-up is essential to confirm whether repair tissue durability maintains long-term patient quality of life after matrix-induced autologous chondrocyte implantation for articular cartilage defects in the knee [19]. Further studies with long-term follow-up are needed to determine whether the grafted area maintains structural and functional integrity after autologous matrix-induced chondrogenesis for focal cartilage defects in the knee [72]. A total knee prosthesis combining multi-radius, ultra-congruency, posterior-stabilization, and mobile-bearing insert shows long-lasting clinically relevant improvements in pain, stiffness, function, and stability at ten-year follow-up [23]. Minimally invasive Oxford unicompartmental knee arthroplasty ensures excellent functional outcome and high survivorship in the long term [20]. Short-term clinical success of anterior cruciate ligament-reconstructed knees appears unaffected by residual laxity, though long-term effects are unknown [22]. There was no difference in clinical outcome as evaluated using IKDC and Marx scores between responders and late responders after anterior cruciate ligament reconstruction [125].

Rehabilitation protocol: A structured preoperative exercise program results in better postoperative functional outcomes at long term [18]. A standardized list of objective and reproducible criteria for rehabilitation following patellar instability surgery should help practitioners focus more on patient-centred factors and less on arbitrary timelines [121]. It is hypothesized that patients in the experimental group using wearable devices for remote monitoring of rehabilitation after total knee arthroplasty would exhibit improved short-term functional outcomes and experience cost and time savings compared to the control group [120].

Functional milestones: Patient self-assessment of shoulder range of motion could potentially replace routine clinic visits for short- and long-term follow-up [122]. All measures of physical capacity in women with fibromyalgia showed a significant association with symptom duration [123].

Other Considerations: Second-generation chondrocyte implantation for knee cartilage lesions shows promising short-term clinical and MRI outcomes [6]. An intraoperative load sensor did not improve early postoperative results of posterior-stabilized total knee arthroplasty for osteoarthritis with varus deformities [21]. Computer-assisted navigation did not result in a statistically significant better functional outcome after short-term follow-up compared to conventional total knee arthroplasty [74]. The natural course of chronic exertional compartment syndrome of the lower leg seems to be persistent symptoms over time [116]. Preoperative symptom duration does not affect clinical outcomes after high tibial osteotomy at a minimum of 2-year follow-up; patients with symptomatic medial knee overload/arthritis of two years or greater do not experience inferior PRO or clinical outcomes than patients with symptom duration of less than 2 years [124].

Key Evidence

• [L3] The functional assessment score is a simple measure of physical function and a means of quantifying an individual's treatment response to joint replacement surgery. (10.1016/j.arth.2008.11.078)
• [L4] Functional scores and radiological outcomes were improved. (10.1186/s13018-024-04730-y)
• [L4] The objective characterization of muscle function performed in this study provides baseline and outcome measures that may quantify specific strength deficits amendable with tailored rehabilitation programs and monitor effectiveness of treatments. (10.1186/1471-2474-10-47)
• [L3] Functional outcome is better predicted by functional tests and validated questionnaires, with proprioception and neuromuscular control playing a key role. (10.1007/s00167-004-0497-5)
• [L3] The use of high-fidelity functional assessment tools that can be integrated into clinical workflow, such as the MICS used in this study, should permit PROM/functional performance comparisons in large populations. (10.1016/j.arth.2022.05.039)
• [L4] The short-term clinical and MRI outcome are promising. (10.1007/s00167-011-1759-7)
• [L3] Clinical impairment measures do not appear to be related to measured functional ability. (10.1177/0363546515578249)
• [L2] Traditional functional tests, such as strength and hop tests, are not able to accurately identify patients who continue to show deficits. (10.1016/j.arthro.2023.12.033)
• [L2] Floor/ceiling effects necessitate complementary outcome measures for comprehensive functional assessment. (10.1016/j.jisako.2025.101000)
• [L5] Advanced imaging, such as MRI, can then be used as necessary but should not replace the history and physical examination. (10.5435/jaaos-d-15-00464)
• [L3] Not all patients performed well on functional testing at 4 months post-operatively, suggesting a role for functional testing to identify patients who may need further physical therapy prior to a return to sports. (10.1016/j.jisako.2024.04.007)
• [L2] Kinematic scores add information to regular outcome tools and offer an effective way to measure functional performance, with the potential to detect early treatment failures. (10.1016/j.jse.2011.05.026)
• [L5] Therapists may use this information to choose the best assessment instrument to evaluate a patient's recovery of function over time. (10.1016/j.jht.2008.11.004)
• [L4] The objective functional results, subjective outcomes and measures of static medial stability are satisfactory in the short term. (10.1007/s00167-021-06502-1)
• [L1] However, it has no effect on functional outcomes. (10.1016/j.jse.2023.10.037)
• [L4] These scores can be used in daily practice as a reference to assess functional outcomes after a surgical procedure. (10.1007/s00167-018-5153-6)
• [L5] The review summarizes the basic principles, advantages, disadvantages, and limitations of methods for evaluating muscular performance, emphasizing the need for accurate terminology and objective, quantitative tests to replace inaccurate or misleading traditional methods. (10.2106/00004623-199072100-00023)
• [L2] A structured preoperative exercise program resulted in better post operative functional outcomes at the long term. (10.1016/j.arthro.2013.07.252)
• [L4] Long-term follow-up is essential to confirm whether the repair tissue has the durability required to maintain long-term patient quality of life. (10.1177/0363546510390476)
• [L3] Oxford UKA of the medial compartment ensures good long-term survivorship with an excellent functional outcome. (10.1007/s00167-018-5299-2)
• [L2] A long-term followup study with a large cohort is required. (10.1007/s00167-018-5314-7)
• [L3] Short-term clinical success appears unaffected by residual laxity; however, long-term effects are unknown. (10.1177/03635465990270051101)
• [L4] The positive results observed in all domains of assessment and the small revision rate demonstrated an effective functioning of the FIRST® prosthesis during the ten-year follow-up period. (10.1007/s00167-022-07216-8)
• [L3] These findings provide greater understanding of the relationship between knee biomechanics during running and clinical assessments of knee function. (10.1007/s00167-017-4810-5)
• [L5] A thorough physical examination and diagnostic work-up, as well as an understanding of the relevant functional anatomy, are essential to proper management. (10.5435/jaaos-21-05-276)
• [L1] Patients with knee osteoarthritis are more likely to display a number of biomechanical characteristics. (10.1186/s12891-018-2202-8)
• [L4] These findings underscore the importance of incorporating neurodynamic assessments into the clinical evaluation of PFPS patients to facilitate more effective management. (10.1186/s12891-025-08951-y)
• [L1] While neither procedure fully restored normal knee kinematics, both anatomic reconstructions were similarly effective for restoring near-normal dynamic knee function. (10.1007/s00167-021-06479-x)
• [L4] This study protocol aims to compare the properties and responsiveness of a selection of commonly used outcome tools that assess function, examine how well they relate to the ICF concepts, and explore the changes in the measures over time. (10.1186/1471-2474-13-220)
• [L1] Further evaluation is needed to determine the clinical relevance of these deficits. (10.1007/s00402-020-03418-2)
• [L3] Clinically meaningful outcomes were established by patient self-assessment. (10.1016/j.arthro.2018.12.014)
• [L5] This classification system must be applied to a variety of muscle architectures and locations to determine its utility; additional studies are therefore needed prior to its general acceptance. (10.1007/s00167-012-2118-z)
• [L1] Clinically, the findings from this systematic review should be considered when assessing and managing patients with LBP. (10.1186/s12891-019-2833-4)
• [L4] This study demonstrated that the knee motion kinematic patterns observed in this study were not similar to normal knee kinematics and derived from the unique design of the Bi-Surface PS. (10.1186/s13018-016-0482-y)
• [L2] Functional knee tests were significant outcome measurements and should be reported separately. (10.1007/s001670050140)
• [L2] Assessing the efficacy of optimal strength training has the potential for immediate and vital clinical impact. (10.1186/1471-2474-14-208)
• [L4] This combination of assessments provides both physical measures of recovery and measures of perceived level of function. (10.1016/j.jht.2009.03.001)
• [L5] The authors encourage emphasizing severe pain with limited range of motion as a reliable clinical sign and congratulate Baldwin et al. for creating a diagnostic algorithm that uses only one laboratory test and no advanced imaging. (10.2106/jbjs.16.00152)
• [L5] Altering the normal ligament length resulted in measurable changes in knee kinematics and stability. (10.1007/s00167-011-1519-8)
• [L4] Results supported the feasibility and acceptability of the study, and participants reported clinically relevant improvements in pain and function. (10.1186/s12891-020-03339-6)
• [L3] Knee biomechanics in the leg with ACLR were altered mainly in the sagittal plane during side-cutting compared with the contralateral leg. (10.1177/03635465221112940)
• [L2] One year after a multidisciplinary treatment a clinically relevant improvement was shown in terms of function, pain, self-efficacy and QoL. (10.1002/ksa.12058)
• [L5] The Minnesota Activity Scale provides standardized questions to comprehensively assess return to activity as a marker of treatment effectiveness. (10.1016/j.jisako.2024.07.005)
• [L4] No braces are currently available with biomechanical evidence that satisfies the requirements of applying correct anatomic joint forces that vary with the knee flexion angle. (10.1007/s00167-012-2048-9)
• [L4] Functional and radiological results were superior in the pediatric patients. (10.1177/03635465241313137)
• [L4] The kinematics of normal knees during high flexion are variable according to activity. (10.1302/0301-620x.100b1.bjj-2017-0553.r2)
• [L4] Twenty-six different criteria described by multiple classification systems have been identified for the magnetic resonance assessment of rotator cuff after repair. (10.1007/s00167-014-3486-3)
• [L5] This model can effectively analyze the biomechanical functions of the superficial and deep layers of the MCLs of knee joints. (10.1186/s13018-017-0566-3)
• [L4] Knee alignment is different in different individuals and is dynamic in nature, changing with different postures. (10.1302/0301-620x.97b4.33740)
• [L3] Patients with lower levels of knee function following ACLR demonstrated hop-landing biomechanics previously associated with early patellofemoral osteoarthritis. (10.1007/s00167-018-5197-7)
• [L2] The role of kinematics in mediating the KFM0-70 provides means for modification of this risk factor, but as boys had higher joint moments, continued investigation into sex-dependent biomechanical risk factors is warranted. (10.1007/s00167-023-07340-z)
• [L5] Further research is needed to develop updated classification systems, and better understand the role of non-invasive and minimally invasive approaches along with standardized rehabilitation protocols. (10.1007/s00167-018-5260-4)
• [L2] Knee biomechanical markers are associated with patient-reported knee function to a greater extent than X-ray grading, but both provide complementary information in the assessment of OA patients. (10.1186/s12891-022-05845-1)
• [L4] Knee motion patterns were consistent across individuals, with differences noted only in the amount of flexion during stance phase between men and women. (10.2106/00004623-197052040-00008)
• [L2] The biomechanical device and treatment methodology is effective in significantly reducing pain and improving function in knee OA patients. (10.1186/1471-2474-11-179)
• [L5] The authors question the pertinence of studying functional differences at only 12 weeks follow-up given that functional recovery continues beyond 6 months and up to 2 years, and note that the small sample size of the referenced study may have been insufficient to detect changes in secondary outcome measures. (10.1007/s00167-011-1810-8)
• [L2] The neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint with no pathological changes in knee function observed. (10.1155/2013/802534)
• [L5] Findings report the status of outcome measure utility and use in pediatric UE function. (10.1016/j.jht.2014.09.004)
• [L3] Fatigue altered sagittal and frontal knee kinematics after 50% fatigue whereupon participants had diminished knee control at initial contact. (10.1007/s00167-013-2673-y)
• [L3] These findings suggest that the contralateral knee can be used as a reliable normal kinematic control. (10.1177/0363546508319051)
• [L3] The PSFS provides a method to assess individual functional limitations, can be completed in a shorter period of time than the DASH and was more acceptable to the patients than the DASH. (10.1016/s0363-5023(12)60062-8)
• [Paper] Physical outcome measures are being changed for the use of patient reported outcomes, and range of motion and strength are not as reliable measures as one would think. (10.1016/j.injury.2019.11.017)
• [L4] Magnetic resonance imaging is recommended as a routine imaging method for accurate diagnosis and appropriate treatment. (10.1177/0363546505278699)
• [L3] MRI findings of varying injury grades did not significantly correlate with the final functional outcomes in this non-athletic population. (10.1186/s12891-024-08119-0)
• [L2] Preoperative MRI scanning identifies a group of patients who have more advanced degenerative joint disease than the clinical assessment and the plain radiographs suggest. (10.1016/j.arthro.2008.10.020)
• [L3] A careful evaluation of upper limb functional capacity and self-reported disability is warranted to provide advice regarding exercises or adjustments at work. (10.1016/j.jht.2017.01.003)
• [L3] These thresholds, specifically developed for MRI, should improve the conventional assessment using the Caton–Deschamps index, originally developed for true lateral radiographs. (10.1002/ksa.12757)
• [L4] However, further studies with long-term follow-up are needed to determine whether the grafted area will maintain structural and functional integrity over time. (10.1007/s00167-010-1042-3)
• [L5] The article highlights the importance of patient selection, noting surgical indication in symptomatic patients having failed a primary nonoperative protocol, and identifies the need for randomized controlled trials to develop a nonoperative strategy. (10.1016/j.arthro.2017.08.238)
• [L2] Computer-assisted navigation did not result in a statistically significant better functional outcome after short-term follow-up. (10.1007/s00167-010-1153-x)
• [L5] The authors introduce a classification system reflecting a consensus reached by the European Rehabilitation Panel to help clinicians identify the cause(s) of patellofemoral pain and select the most appropriate non-operative treatment. (10.1007/s00167-004-0577-6)
• [L4] In particular, symptomatic cases with inconspicuous conventional MRI imaging, additional MRI imaging only in the axial plane in a 20° of knee flexion could be beneficial and useful in clinical daily routine. (10.1186/s12891-021-04733-4)
• [L4] If nonoperative treatment fails, this condition can be successfully treated with surgical stabilization. (10.1177/03635465990270031901)
• [L3] Further testing of the IKDC guidelines is necessary to determine if they are capable of detecting a change in the patients over time following treatment and/or surgery of the knee. (10.1007/s001670050082)
• [L4] However, the study did not establish when the muscles changed their phase of activity or address the indications for the procedure. (10.2106/00004623-198062060-00014)
• [L4] At short-term to midterm follow-up, 63% of patients successfully returned to military function with a low rate of perioperative complications (8%). (10.1016/j.arthro.2016.03.027)
• [L4] Patients with more severe imaging lesions tend to have poorer ROM. (10.1186/s12891-023-06432-8)
• [L3] MRI-based graft maturity does not have the ability to predict clinical and functional outcomes in patients at the first-year follow-up. (10.1007/s00167-016-4252-5)
• [L4] Patients can be counselled that although radiographic severity of arthritic changes can predict knee-specific functional improvement, the extent of their global functional improvement cannot. (10.1007/s00167-015-3806-2)
• [L3] However further studies are warranted to assess the long-term outcomes of PFA. (10.1186/s42836-021-00074-8)
• [L1] This study found no significant differences in clinical or functional outcomes between KA and MA despite distinct radiological alignment outcomes after 1-year follow-up. (10.1002/ksa.70004)
• [L2] Overall, this study provides protective clinical parameters as well as quantitative and semi-quantitative MR-imaging parameters associated with maintaining radiographically normal knee joints in an older population over 8 years. (10.1186/s12891-024-07590-z)
• [Paper] Physical therapy management of osteochondritis dissecans can incorporate a full spectrum of conservative, nonoperative, and postoperative care. (10.1016/j.csm.2014.01.001)
• [L5] A non-operative treatment of patients with anterior knee pain should be tried for at least 3 months before considering other treatment options. (10.1007/s00167-014-3150-y)
• [L5] The new dynamic MRI technique appears applicable to practices across the country and could become a new standard tool, but further adequately powered studies are needed to determine clinical relevance and address study limitations. (10.1016/j.arthro.2017.11.018)
• [Case_report] MRI interpretations demonstrate improved clinical outcome measures ensuing therapeutic intervention with PPS, and warranting further investigation into the efficacy of PPS in the treatment of BML associated pain and dysfunction in the osteoarthritic population via randomized controlled trial, or equivalent rigorous methodological technique. (10.1186/s12891-017-1754-3)
• [L2] Favorable outcomes can occur after both operative and nonoperative management approaches with the use of progressive criterion-based rehabilitation. (10.1177/0363546518782698)
• [L2] The MRI shorthand is a simple and efficient means of assessing the skeletal maturity of adolescent patients with a knee MRI scan. (10.1177/03635465211032986)
• [L2] Presentation factors that increase the likelihood of a diagnostic X-ray included pain for longer than 6 months, the presence of medial or diffuse pain, and mechanical symptoms. (10.1007/s00167-014-3003-8)
• [L4] Caution should be exercised when using plain radiographs for preoperative planning or postoperative evaluation. (10.1186/s13018-025-06106-2)
• [L3] A low radiological severity of osteoarthritis was not associated with pain 12 months postoperatively. (10.1302/0301-620x.96b11.33726)
• [L4] Nonoperative treatment should not be extended more than 1 year from injury. (10.1177/0363546509333479)
• [L4] Numerous scoring systems have been devised to evaluate patients who have symptoms related to the knee, but demographic variables such as advanced age, low family income, and multiple medical conditions significantly affect scores. (10.2106/00004623-199706000-00009)
• [L1] Non-operative physical modalities of treatment are of benefit when treating OA of the knee, though much of the literature reviewed evaluates studies with follow-up of less than six months. (10.1302/0301-620x.98b1.36353)
• [L3] A novel classification system for patients with recurrent patellar subluxation and excessive femoral torsion based on segmental femoral torsion analysis was established. (10.1186/s13018-024-05123-x)
• [Paper] The guidelines recommend using reproduction of retropatellar pain during squatting and other functional activities for diagnosis, and propose a classification system based on predominant impairments. (10.2519/jospt.2019.0302)
• [L4] Surgical release was effective in a case where nonoperative treatment failed. (10.1007/s00167-003-0382-7)
• [L4] Shoulder physical functions were mapped to outcome scores. (10.1016/j.jse.2019.08.017)
• [L4] The ICF HandA provides a consensus on outcome measures and instruments to systematically assess function in patients with hand injuries and disorders. (10.1177/1753193417706248)
• [Paper] Although the flexion range deteriorates postoperatively due to reformation of adhesions, this loss is statistically non-significant regarding the overall functional outcome scores. (10.1016/j.injury.2014.04.042)
• [L3] Nonoperative management of adolescent mid-shaft clavicle fractures results in excellent functional outcomes at long-term follow-up. (10.1302/0301-620x.103b5.bjj-2020-1929.r1)
• [L4] Therefore, if patients present with negative predictor factors, the AM should not be proposed as second-line treatment, and nonoperative management should be continued until TKR is unavoidable. (10.1016/j.arthro.2020.11.053)
• [L4] Nonoperative treatment with a healing phase and a strict rehabilitation plan results in a functional, efficient reattachment of the tendon and allows unrestricted return to play. (10.1007/s00167-015-3669-6)
• [L5] Future directions should prioritise injury prevention, early diagnosis, and targeted interventions that combine non-surgical and minimally invasive orthobiological approaches. (10.1136/jisakos-2017-000145)
• [L2] One in 2 patients reported acceptable long-term knee function, but no risk factor for poorer subjective knee function was identified. (10.1016/j.arthro.2018.07.009)
• [L3] Five years after ACLR, thigh muscle adaptation depended on graft choice and carried meaningful functional consequences. (10.1177/23259671261432585)
• [L4] In the absence of serious complications, most patients had improvement in most components of function, with greater gains occurring during the first six months and lesser but continued gains between the sixth and twenty-fourth postoperative months. (10.2106/00004623-197557030-00009)
• [L4] The procedure appears to be both effective and relatively free of late complications, with decreased knee-flexion deformity and improved walking function achieved in 91 per cent of patients. (10.2106/00004623-197961050-00012)
• [L2] The children had good objective physical function 1 and 3 years after ACL reconstruction. (10.1002/ksa.12211)
• [L4] At an average 9 years after surgery, patients did not have symptoms of osteoarthritis pain and had normal function in activities of daily life, but reported significantly lower knee-related quality of life. (10.1177/0363546508328119)
• [L4] The natural course of CECS seems to be persistent symptoms over time. (10.1007/s00167-014-2847-2)
• [L3] Four distinct 5-year trajectories of patient-reported knee function were identified, with 88% of patients following Moderate and High trajectories characterized by good improvement and high scores. (10.1177/03635465221116313)
• [L3] These recovery trajectories can distinguish outcome after one year. (10.1186/s12891-021-04037-7)
• [L1] Both open kinetic chain and closed kinetic chain programs lead to an equal long-term good functional outcome. (10.1177/0363546503262187)
• [L2] The authors hypothesize that patients in the experimental group would exhibit improved short-term functional outcomes and experience cost and time savings compared to patients in the control group. (10.1186/s13018-023-03898-z)
• [L5] The standardized list of objective and reproducible criteria for rehabilitation should help practitioners focus more on patient-centred factors and less on arbitrary timelines. (10.1007/s00167-019-05510-6)
• [L3] This method for short- and long-term follow-up could potentially replace routine clinic visits. (10.1016/j.jse.2016.02.010)
• [L3] All measures of physical capacity showed a significant association with symptom duration. (10.1186/s12891-018-2047-1)
• [L4] Patients with a preoperative duration of symptomatic medial knee overload/arthritis of two years or greater do not experience inferior PRO or clinical outcomes than patients with a symptom duration of less than 2 years at mid-term follow-up. (10.1016/j.jisako.2022.03.003)
• [L3] There was no difference in clinical outcome as evaluated using IKDC and Marx scores between responders and late responders. (10.1177/03635465211047858)

See Also

• Biomechanics
• Anterior Cruciate Ligament
• Anatomy
• Total Knee Replacement

References

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[82] MRI-based ACL graft maturity does not predict clinical and functional outcomes during the first year after ACL reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 2016. DOI: 10.1007/s00167-016-4252-5

[83] Severe arthritis predicts greater improvements in function following total knee arthroplasty. Knee Surgery, Sports Traumatology, Arthroscopy. 2015. DOI: 10.1007/s00167-015-3806-2

[84] Patient-related outcomes of patellofemoral arthroplasty: experience of a single center. Arthroplasty. 2021. DOI: 10.1186/s42836-021-00074-8

[85] No differences in functional and clinical outcomes after rehabilitation between modified kinematic and mechanical alignment in total knee arthroplasty: A randomized controlled trial. Knee Surgery, Sports Traumatology, Arthroscopy. 2025. DOI: 10.1002/ksa.70004

[86] Clinical and imaging findings associated with preservation of knee joint health over 8 years in individuals aged 65 and over: data from the OAI. BMC Musculoskeletal Disorders. 2024. DOI: 10.1186/s12891-024-07590-z

[87] Physical Therapy Management of Patients with Osteochondritis Dissecans. Clinics in Sports Medicine. 2014. DOI: 10.1016/j.csm.2014.01.001

[88] Anterior knee pain: an update of physical therapy. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3150-y

[89] Editorial Commentary: Is Magnetic Resonance Imaging Imaged Knee Patellar Tracking Relevant in Assessing the Patient With Patellar Instability?. Arthroscopy. 2018. DOI: 10.1016/j.arthro.2017.11.018

[90] Improved clinical outcome measures of knee pain and function with concurrent resolution of subchondral Bone Marrow Edema Lesion and joint effusion in an osteoarthritic patient following Pentosan Polysulphate Sodium treatment: a case report. BMC Musculoskeletal Disorders. 2017. DOI: 10.1186/s12891-017-1754-3

[91] Does Anterior Cruciate Ligament Reconstruction Improve Functional and Radiographic Outcomes Over Nonoperative Management 5 Years After Injury?. The American Journal of Sports Medicine. 2018. DOI: 10.1177/0363546518782698

[92] Creation and Validation of a Shorthand Magnetic Resonance Imaging Bone Age Assessment Tool of the Knee as an Alternative Skeletal Maturity Assessment. The American Journal of Sports Medicine. 2021. DOI: 10.1177/03635465211032986

[93] The utility of plain radiographs in the initial evaluation of knee pain amongst sports medicine patients. Knee Surgery, Sports Traumatology, Arthroscopy. 2014. DOI: 10.1007/s00167-014-3003-8

[94] Effect of lower limb rotation on radiographic measurements of femoral and tibial joint line obliquity and their association with measurement changes: a digitally reconstructed radiograph evaluation. Journal of Orthopaedic Surgery and Research. 2025. DOI: 10.1186/s13018-025-06106-2

[95] Low grading of the severity of knee osteoarthritis pre-operatively is associated with a lower functional level after total knee replacement. The Bone & Joint Journal. 2014. DOI: 10.1302/0301-620x.96b11.33726

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