The patellofemoral (PF) joint plays an integral role in knee biomechanics. Disorders of the PF joint are prevalent and a common source of anterior knee pain, particularly in younger and active patients. Abnormalities related to patellar tracking can lead to recurrent lateral patellar dislocation, early degenerative changes, and poor clinical outcomes if not detected and treated appropriately. Therefore, early recognition of PF instability is imperative to preserving joint function and improving long-term patient outcomes. Several alignment and morphological abnormalities are known risk factors that predispose patients to PF instability, including patellar malalignment, trochlear dysplasia, tibial tubercle lateralization, genu valgus, and rotational deformities. Imaging plays a key role in identifying these abnormalities and other osteoarticular and soft tissue pathology of the PF joint. Additionally, several quantitative measurements performed on imaging provide objective information on patellar alignment and tracking, further aiding clinicians with diagnosis and treatment planning. A consistent and standardized approach to the quantitative imaging evaluation of the PF joint is necessary for accurate reporting of measurements and imaging findings. This article highlights essential PF joint anatomy, current and evolving imaging techniques, and clinically relevant measurements for the evaluation of patients with suspected PF instability.

Objective: The aim of the study was to compare postoperative pain, functional recovery, knee stability and complication profiles between the all-inside technique and the conventional full tibial tunnel technique for anterior cruciate ligament (ACL) reconstruction. Methods: This retrospective comparative cohort study included 104 patients who underwent primary ACL reconstruction between 2018 and 2020. Surgical technique allocation was non-randomized. Patients were divided into two groups based on the surgical technique employed; the conventional full tibial tunnel group (n = 58) and all-inside group (n = 46). Hamstring tendon autografts were used in all cases, and the procedures were performed by the same surgical team to ensure consistency. Clinical outcomes were evaluated using the Visual Analog Scale (VAS) for pain, Lysholm knee score and International Knee Documentation Committee (IKDC) score. Knee stability was assessed with the Lachman and pivot-shift test. Additionally, postoperative complications and revision rates were recorded. Results: The study included 104 patients, with 58 treated using the conventional technique and 46 using the all-inside technique. Baseline characteristics, trauma mechanisms, and follow-up duration were comparable between groups (p > 0.05). Four patients in each group underwent revision surgery and excluded from the final analysis. Revision rates were comparable between groups (6.9% vs. 8.6%) and were considered descriptively when interpreting outcomes. The preoperative VAS, Lysholm and IKDC scores were comparable between groups. At 3 months, the all-inside group demonstrated significantly lower VAS pain scores and higher Lysholm and IKDC scores (with moderate-to-large effect sizes) (all p < 0.01). No significant differences were observed at the 12-month or final follow-up. Postoperative knee stability was comparable between groups, whereas anterior knee pain was significantly less frequent in the all-inside group (p < 0.001). Moreover, patients treated with the all-inside technique returned to sports significantly earlier than those treated with the conventional technique (13.25 ± 2.70 vs. 16.40 ± 5.85 months, p < 0.001; Cohen’s d = 0.66). However, the proportion of patients who returned to their preinjury sports level was comparable between the two groups (81.0% vs. 83.3%, p = 0.78). Conclusions: The all-inside ACL reconstruction technique was associated with superior early pain relief and short-term functional outcomes compared with the conventional technique, while achieving comparable knee stability and mid-term clinical results. These advantages occur without increasing complications or revision rates. These findings support the all-inside technique as patient-centered, optimizing early recovery without sacrificing mid-term clinical durability. These findings should be interpreted in the context of the non-randomized retrospective study design.

Persistent knee pain can develop after anterior cruciate ligament injury with subsequent anterior cruciate ligament reconstruction (ACLR) despite a functionally intact graft. To identify the prevalence of clinically significant knee pain in patients at 2, 6, and 10 years after ACLR. Cohort study; Level of evidence, 2. 3272 patients were enrolled into the Multicenter Orthopaedic Outcomes Network (MOON) between 2002 and 2008 across 7 centers. Each patient completed a questionnaire at baseline that included demographic characteristics, injury factors, participation in sports, and validated outcome measures including the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscale (scored 0-100 with higher scores signifying less pain). Each patient completed the questionnaire again at 2, 6, and 10 years postoperatively. Three different criteria were used to define clinically significant knee pain: KOOS pain ≤70 points, KOOS pain ≤80 points, or responding "moderate,""severe," or "extreme" to a KOOS pain question. Median age in the cohort was 23 years (interquartile range, 17-27 years) at the time of enrollment, and 44% of patients were female. A total of 2798 patients (85%) responded to the questionnaire at 2 years postoperatively, with 2759 (84%) responding at 6 years and 2526 (77%) at 10 years. The prevalence of those with KOOS pain ≤70 was 9.3%, 9.0%, and 9.1% at 2, 6, and 10 years after surgery, respectively. The prevalence of KOOS pain ≤80 was 16.6%, 16.3%, and 15.7% at each timepoint, respectively. When a KOOS pain response of "moderate,""severe," or "extreme" was used, the prevalence was 26.3%, 22.9%, and 22.6% at 2, 6, and 10 years, respectively. Interestingly, very few patients had persistent pain at all 3 follow-up points: 48 (1.6%) reported a KOOS pain score ≤70 points, 103 (3.5%) reported a KOOS pain score ≤80 points, and 161 (5.6%) reported moderate or severe pain. The prevalence of clinically significant postoperative knee pain after ACLR was up to 26% at 2 years postoperatively, a percentage that remained unchanged or slightly decreased at 6- and 10-year follow-up. Despite this finding, it was uncommon for individual patients to report clinically significant knee pain at multiple follow-up timepoints.

ABSTRACT Objective The primary objective of this study was to describe the musculoskeletal health of retired elite women’s footballers, with a particular emphasis on hip, knee and ankle pain and function. Methods Retired elite women’s footballers (18 years or older) were surveyed on their history of severe hip, knee and ankle injuries, and previous joint surgery. Validated questionnaires (e.g. Knee Injury and Osteoarthritis Outcome Score Physical Function Short Form (KOOS-PS)) were used to assess health outcomes, such as level of function and pain. Results 62 respondents completed the survey (mean age 35.5 years, mean age at retirement 30.5 years). Nineteen (30.6%) retired players reported experiencing hip pain at least once per month. Forty-four (71%) participants had at least one severe knee injury during their career, with nearly a third (n = 20, 32.3%) experiencing knee pain on a weekly basis. The majority (n = 48, 77.4%) of participants had experienced at least one severe ankle injury during their career. Hip, knee and ankle pain was associated with a history of severe hip, knee or ankle injury during a playing career. A history of ankle surgery was associated with ankle pain. Mean KOOS-PS score (84.7) was lower than that seen in the general population, while hip/ankle outcome measures were comparable to the general population. Conclusion Musculoskeletal complaints, especially knee-related issues, are common amongst retired elite women’s footballers, and are associated with severe injuries during a player’s career. Collaborative injury prevention efforts are likely to lead to positive health benefits for current, future and former elite women’s footballers.

Abstract: BACKGROUND: Blood flow restriction (BFR) training is an evolving intrusion in rehabilitation that syndicates low-load resistance exercise with vascular occlusion, characteristically through the solicitation of inflatable cuffs or elastic bands. Groin pain is a frequent and operationally limiting condition among athletes, particularly in sports requiring rapid directional changes and high-intensity movements. Practical BFR training (pBFRT) has emerged as a potential rehabilitative approach, yet its effect on groin pain specifically in athletic populations remains underexplored. Prior studies have experimented the effect of BFR training on the knee pain and in elder patients, and there are very less rehabilitative measures that can be undertaken for treating groin pain in athletes. OBJECTIVE: This study aims to analyze the effect of pBFRT on groin pain in athletes and the rate of recovery in them. METHODOLOGY: This study included a quasi-experimental pretest and posttest design used on 50 male athletes (aged 16–24) suffering from groin pain. Participants performed 4 weeks of lower-limb resistance training using elastic BFR bands. Pain and recovery were assessed using the hip and groin outcome score (HAGOS) and total quality recovery (TQR) scale, respectively. RESULTS: Noteworthy enhancements were witnessed after training. The HAGOS score amplified from 30.4 ± 16.3 to 77.8 ± 14.5 (mean difference = 47.4; 95% confidence interval [CI]: 41.6–53.1; P < 0.001; Cohen’s d = 2.96). TQR scores increased from 10.6 ± 0.25 to 15.5 ± 2.5 (mean difference = 4.9; 95% CI: 4.6–5.1; P < 0.001; Cohen’s d = 2.59). These results propose a large effect size and strong clinical significance. Correlation analysis revealed no significant relationship between pain reduction and recovery improvement ( r = 0.19, P = 0.187), suggesting these outcomes may improve independently. CONCLUSION: This study concludes that pBFRT seems to be an efficient approach for decreasing groin pain and boosting recovery and functional outcomes. It offers a low-load, practical method that could be incorporated into present rehabilitative measures to maximize recovery outcome with reduced burden. Its addition into physiotherapy procedures may decrease rehabilitation encumbrance and facilitate earlier return to sport. Further studies should include physiological measures, larger samples, and diverse demographics.

Fear of pain and reinjury significantly hinders return to sports (RTS) after anterior cruciate ligament reconstruction (ACLR). However, the neural basis of this psychological barrier remains unclear. ACLR patients will exhibit structural and functional brain changes in regions related to pain and emotion, influencing their psychological readiness to RTS. Cross-sectional study. Level 3. We recruited 36 ACLR patients and 36 healthy controls, collecting visual analog scale (VAS) scores for knee pain, Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scores, and structural and functional magnetic resonance imaging data. Significant smaller gray matter (GM) volume was observed in the thalamus (effect size, -0.813), periaqueductal gray (PAG) (effect size, -0.737), and prefrontal cortex (PFC) (effect size, -0.690) in ACLR patients. We also found weakened functional connectivity between the PAG and the anterior cingulate cortex (ACC). GM volume in the thalamus was correlated positively with ACL-RSI scores (r = 0.362). Notably, the effect of VAS scores on ACL-RSI was mediated by the reduced FC between PAG and ACC (direct effect, -2.071, indirect effect, -0.826). This study reveals that the psychological readiness to RTS after ACLR may be due to peripheral nociceptive input causing changes in pain-related brain structures and functions. Recognizing these neuropsychological changes may guide comprehensive rehabilitation strategies post-ACLR, emphasizing the need for interventions targeting central neural mechanisms alongside physical recovery.

Non-traumatic knee pain in an adolescent boy.

Studies have linked lower birth weight to development of radiographic osteoarthritis (OA). We examined early life factors in relation to subsequent knee pain among individuals with radiographic OA. 143 participants from the UK Hertfordshire Cohort study were included. Birth weight and weight at one year (WA1) were ascertained from health ledgers and used to derive conditional infant weight gain (CIWG). At baseline and follow-up, heath questionnaires (including knee pain) and knee radiographs were collected. Only those with radiographic knee OA at baseline were analysed. Logistic regression was used to examine early life factors in relation to pain. Pain at follow-up was common (men 41.3%, women 50%). Greater WA1 and greater CIWG were related to reduced risk of knee pain at follow-up after adjustment for sex and follow-up time. CIWG was protective against knee pain at follow-up, with this association attenuated after adjustment for follow-up osteophyte score. Validation in larger studies is required.

Refractory Chronic Knee Pain After Total Knee Replacement Successfully Treated With L4 Dorsal Root Ganglion Pulsed Radiofrequency

Tenosynovial giant cell tumor (TGCT), formerly pigmented villonodular synovitis (PVNS), may extend into the popliteal fossa and mimic a Baker cyst, complicating diagnosis and operative planning. A 53-year-old former endurance runner presented with posterior knee pain, swelling, intermittent locking, and a palpable popliteal mass. Examination demonstrated effusion and limited range of motion; weightbearing radiographs showed mild osteoarthritic change with effusion, and magnetic resonance imaging (MRI) revealed synovial hypertrophy with low T2 signal suggestive of hemosiderin deposition. Arthroscopic synovectomy via 4 anterior and 2 posterior portals was performed; histology confirmed diffuse, nonmalignant TGCT. Given persistent posterior disease, a staged posterior open approach (lazy-S incision) enabled en bloc excision of the extra-articular component. Adjuvant radiosynoviorthesis (intra-articular yttrium-90) was administered. At 8-year follow-up, there was no clinical or radiographic evidence of disease. This case emphasizes MRI recognition of hemosiderin-related low T2 signal, the value of combining arthroscopic synovectomy with posterior open excision in diffuse disease with popliteal extension, and selective use of adjuvant radiosynoviorthesis for durability.

Background Virtual health is evolving rapidly, yet knowledge regarding patients’ experiences of video-based knee assessment remains limited. The aim was to explore patients’ experiences and perceptions of video-based assessment of the knee in contrast to conventional face-to-face assessment. Methods A qualitative focus group study was conducted with sixteen participants aged 45 years or older with non-traumatic knee pain. Participants were recruited from a previous study comparing video-based physiotherapy assessment with conventional face-to-face assessment of potential KOA among patients with non-traumatic knee pain. They were divided into four groups of four to seven participants. Group discussions lasted 35–40 min. Discussions were audio recorded, transcribed verbatim, and analysed inductively using qualitative content analysis as described by Krueger and Casey. Results The analysis resulted in four categories with two to three subcategories each, under the overarching theme Another road to diagnosis. The categories were: clear and adequate communication, a different personal contact, increased patient responsibility, and confidence in being adequately assessed. Conclusion The main findings of this study underscore the essential role of trust in the diagnostic process and suggest that the experience and nature of assessment may take another form in the video-based context in relation to conventional face-to-face assessment. The findings suggest that video-based assessment can be perceived as a feasible alternative to face-to-face assessment by patients, particularly those who trust the physiotherapist and can perform their part of the assessment and who, for various reasons, need flexibility regarding location.

High blood pressure (BP) often co-occurs with osteoarthritis (OA) and may influence pain sensitivity, potentially contributing to pain-pathology discordance. We hypothesized that higher BP would associate with reduced pain sensitivity and greater OA severity in adults with chronic knee pain. A cross-sectional analysis of 213 community-dwelling adults (44-78 years) with chronic knee pain was conducted. Hypertension was defined by diagnosis or antihypertensive use; others were normotensive. Systolic, diastolic, pulse (PP), and mean arterial (MAP) BP were measured. Quantitative sensory testing assessed pressure/thermal pain sensitivity, temporal summation (TS), and conditioned pain modulation (CPM). Radiographic knee OA (rKOA) was graded using the Kellgren-Lawrence scale. Models adjusted for race, age, BMI, site, and diabetes. Blood pressure-pain associations were moderated by sex and hypertensive status, observed only in normotensive individuals. Among normotensive males, each 10 mmHg increase in BP was associated with reduced pressure pain sensitivity (β [95% CI]: systolic -0.21 [-0.42, -0.002]; diastolic -0.36 [-0.68, -0.05]; MAP -0.31 [-0.59, -0.03]; all p < 0.05) but greater odds of late-stage rKOA (AOR [95% CI]: systolic 1.70 [1.07, 2.70]; MAP 2.10 [1.10, 4.01]). Among normotensive females, temporal summation of mechanical pain increased with higher BP (β [95% CI]: systolic 0.14 [0.01, 0.27], p = 0.027; PP 0.20 [0.02, 0.38], p = 0.026). No significant associations were observed for heat/cold pain sensitivity, TS of heat pain, or CPM. Elevated BP was associated with hypoalgesia and more severe rKOA severity in normotensive males. In normotensive females, elevated BP showed greater pain facilitation but not rKOA severity. Together, these sex-specific findings suggest BP as a vascular factor contributing to pain-pathology mismatch in OA. Associations between arterial blood pressure and pain in older adults with knee pain were found to be sex- and hypertension-dependent, primarily evident in normotensive individuals. Elevated blood pressure was associated with reduced mechanical pain sensitivity but greater radiographic OA in normotensive males; normotensive females showed enhanced pain facilitation without increased OA severity. These findings support arterial pressure as a shared vascular factor in pain-pathology mismatch and highlight the importance of incorporating cardiovascular markers into chronic pain phenotyping and interpretation.

Prevalence and Role of Psychiatric Conditions in Patients Diagnosed with Anterior Knee Pain

Patellar management in primary total knee arthroplasty (TKA) remains one of the most debated and variable aspects of contemporary arthroplasty practice. Patellar resurfacing, non-resurfacing, and selective resurfacing each offer distinct advantages, but no universally superior strategy has emerged. Although global functional outcomes are generally comparable across techniques, differences persist in anterior knee pain, survivorship, patellofemoral degeneration, and the likelihood of secondary patellar procedures. This narrative review synthesizes current clinical, radiographic, biomechanical, and registry-based evidence to provide a comprehensive understanding of these differences. Patellar resurfacing tends to offer clearer benefits in patients with advanced patellofemoral osteoarthritis, significant preoperative symptoms, unfavorable patellar morphology, or implant designs that increase patellofemoral loading. Conversely, non-resurfacing remains a safe and effective option in patients with minimal patellofemoral disease and favorable anatomical characteristics. Selective resurfacing represents a patient-tailored compromise, though its effectiveness is currently limited by the absence of standardized selection criteria. The integration of evidence across multiple studies reinforces that patellar resurfacing should follow an individualized, indication-guided approach instead of routine application. It also proposes a structured framework that incorporates anatomical, radiographic, and implant-related factors to guide patellar management during primary TKA.

Introduction: Knee Osteoarthritis (KOA) plays a substantial role in the global burden of musculoskeletal disorders. Biomechanical factors such as leg dominance are hypothesised to contribute to the onset and progression of KOA; however, the relationship between dominant limb use and symptom development remains unclear. Aim: To investigate the association between leg dominance and the onset and side of symptoms in KOA, utilising both a validated questionnaire and standardised functional task assessments. Materials and Methods: A cross-sectional study was conducted at the Department of Sports Physiotherapy, KLE Institute of Physiotherapy, Belagavi, Karnataka, India, over 11 months, from May 2024 to March 2025. It involved 131 individuals aged between 45 and 70 years with radiologically confirmed Grade I or II KOA. Leg dominance was assessed through a standardised questionnaire and six motor tasks. The data collected were compiled in Microsoft Excel and analysed using IBM Statistical Package for the Social Sciences (SPSS) Statistics version 29.0. Chi-square tests and t-tests were used to analyse associations. Results: A total of 131 participants (55 males and 76 females) were included in the final analysis. Right leg dominance was identified in 124 (94.7%) of the participants across all motor tasks, with a high concordance noted in the ball-kicking task between self-report and observation. Right knee pain was more common, reported by 111 (84.7%) participants, and the majority noted a gradual onset of symptoms, with 110 (84%) indicating this pattern. All left-leg dominant individuals were female and exhibited left-sided KOA (p-value &lt;0.001). Sudden onset of symptoms was significantly associated with left-leg dominance, observed in 5 (71.4%) participants (p-value=0.001). Conclusion: The study identified a significant association between leg dominance and both the side and onset of KOA symptoms. Dominant limb mechanics may play a role in asymmetric joint loading and early symptom manifestation. Assessing leg dominance through both self-report and task observation may aid in the early identification of at-risk individuals and support targeted rehabilitation planning.

The senescence-associated secretory phenotype (SASP) contributes to tissue degeneration and inflammation, yet its role in osteoarthritis (OA)-related pain remains poorly understood. We hypothesized that circulating SASP markers would be associated with distinct OA-pain phenotypes, defined by pain impact and radiographic OA (ROA) severity. A subset of middle-to-older-aged adults (45-85 years) from a larger multi-site study (n = 169) self-reported pain impact-defined as the extent to which pain interferes with daily functioning-and underwent knee radiography and blood collection. Hierarchical cluster analysis was used to empirically identify OA-pain phenotypes based on combined pain impact and Kellgren-Lawrence (KL) grade. Plasma levels of four SASP markers (GDF-15, activin A, osteopontin, and IL-15) were quantified from whole blood samples. Among 169 participants, 35.5% reported high-impact chronic knee pain and 27.8% exhibited moderate-to-severe radiographic OA. Cluster analysis identified five distinct ROA-pain phenotypes. GDF-15 levels were significantly elevated in non-Hispanic White females with early ROA and high-impact pain, with race- and sex-dependent differences. Activin A levels were higher in non-Hispanic Black participants without pain or ROA and varied by sex in early ROA/low-impact pain phenotypes. Osteopontin levels were elevated in males compared to females within the same phenotype group. IL-15 levels showed no association with ROA-pain phenotypes but were higher in males and positively correlated with age. SASP factors, particularly GDF-15, Activin A, and Osteopontin, demonstrated race- and sex-dependent associations with OA-pain phenotypes. These findings underscore the importance of demographic context in OA pathophysiology and support further investigation into SASP factors as potential biomarkers and therapeutic targets for OA-related pain.

Bilateral discoid medial menisci are an exceptionally rare anatomical variant, and their coexistence with a parameniscal cyst has only been described in isolated cases. We present the case of a 13-year-old male with activity-related medial knee pain initially affecting the right knee. Imaging confirmed an incomplete discoid medial meniscus associated with a parameniscal cyst, which was treated with arthroscopy, open cyst excision, and meniscocapsular repair. A subsequent symptomatic retear required revision saucerization and combined meniscal fixation techniques. Months later, the patient developed similar symptoms in the contralateral knee, where MRI revealed a discoid medial meniscus with a horizontal tear, successfully treated with saucerization and partial meniscectomy. At final follow-up, the patient remained pain-free and fully active. This case highlights the importance of early recognition and preservation-focused surgical treatment for this rare bilateral presentation.

This study aimed to clarify the clinical relevance of quadriceps tendon alignment (QTA), focusing on the quadriceps tendon axial angle (QTAx), in patients undergoing 'physiological total knee arthroplasty (TKA)'. This concept combines unrestricted kinematic alignment (KA) with a medial pivot implant to alter as little as possible the individual knee anatomy and kinematics. It was hypothesised that QTAx would not significantly influence patient-reported outcomes. A retrospective cohort analysis was performed on 54 knees in 50 patients who underwent physiological TKA performed with a non-KA-optimised implant design and without patella resurfacing between September 2022 and April 2024. Patient-reported outcomes, including the Oxford knee score, forgotten joint score, patient's joint perception, pain visual analogue scale and satisfaction visual analogue scale, were evaluated before surgery and at 1 year postoperatively. QTAx was measured on preoperative computed tomography scans. Patients were categorised into three groups according to their QTAx angle: low (<mean -1 SD), middle (within mean ±1 SD) and high (>mean +1 SD). Significant improvements were observed in all patient-reported outcomes 1 year after surgery. QTAx demonstrated no significant correlation with any outcome. Clinical results did not differ significantly among the three QTAx alignment groups, although the high-angle group tended to show slightly better outcomes. Two patients (3.7%) underwent secondary patellar resurfacing for persistent anterior knee pain. This study found that variation in QTA, as assessed by QTAx, was not significantly associated with 1-year clinical outcomes following physiological TKA performed with a non-KA-optimised implant and without patellar resurfacing. Our findings suggest that specific surgical techniques to counteract high QTA may not be necessary within the context of physiological TKA. Level III.

Corrigendum to "Successful Medial Meniscal Repair Reduces Knee Pain 10 Years After Anterior Cruciate Ligament Reconstruction: Exploring the Consequences of Subsequent Surgery With Causal Mediation Analysis in the MOON Cohort".

Anterior knee pain remains a leading cause of dissatisfaction following total knee arthroplasty (TKA), often without overt mechanical complications. The biomechanical consequences of altered patellar thickness remain incompletely understood. This study evaluated the effects of reconstructed patellar thickness on patellofemoral joint (PFJ) kinematics and kinetics using a cadaveric model. Eleven knees from six unembalmed whole-lower-extremity cadaveric specimens were tested with a robotic simulator and optical motion capture. Patellar thickness was altered in three conditions: understuffed (-3 mm), neutral (native) and overstuffed (+4 mm). PFJ kinematics and contact forces were assessed during passive flexion and simulated stair descent. Total force and regional pressures at the medial facet C1, central ridge C2 and lateral facet C3 were recorded using a custom multi-sensor array. Overstuffing significantly altered PFJ kinematics, including increased posterior translation (p < 0.001), reduced flexion (p = 0.001) and altered valgus alignment (p = 0.020). Composite PFJ force increased with thickness during passive flexion (overstuffed 59.9 N; neutral 33.9 N; understuffed 23.5 N; p < 0.001) and stair descent (50.5 N, 27.5 N, 17.9 N; p < 0.001). Regional analysis showed a lateral shift in loading, with the lateral facet most affected (p < 0.001). Understuffing reduced joint pressures with minimal kinematic change. Small increases in reconstructed patellar thickness significantly alter PFJ motion and load distribution, particularly lateral facet forces. These results highlight the biomechanical sensitivity of the PFJ to thickness variation and support the need for thinner, modular or patient-specific components to enable finer intraoperative control. Restoring native geometry may help reduce anterior knee pain and dissatisfaction after TKA. Level IV, controlled laboratory study.