Abstract. INTRODUCTION. This study aimed to examine how physical activity and health-related quality of life (HRQoL) evolved over the first year after total knee replacement (TKR) for patients with and without post-operative chronic knee pain. METHODS. 83 adults participating in the PEP-TALK, a RCT testing the effectiveness of a behaviour change physiotherapy intervention versus usual rehabilitation post-primary TKR, were analysed. UCLA Activity Score and EQ-5D-5L values for participants with and without chronic knee pain (14 points or lower in the Oxford Knee Score Pain Subscale at six months post-TKR) were compared at six and 12 months post-TKR. We evaluated recovery trajectory those with or without chronic pain at these time points. RESULTS. Participants with chronic knee pain, UCLA Activity Score remained unchanged between baseline to six months (mean: 3.8 to 3.8), decreasing at 12 months (mean: 3.0). Those without post-operative chronic knee pain reported a improvement in physical activity from baseline to six months (mean: 4.0 vs 4.9), plateauing at 12 months (mean: 4.9). Participants with chronic knee pain reported lower baseline HRQoL, although both groups improved mean health utility over one year. Of participants who were not defined as being in chronic pain at six months, 8.5% returned to a chronic pain categorisation by 12 months. CONCLUSION. People with chronic knee pain post-TKR report poorer physical activity and HRQoL scores post-operatively. Monitoring outcomes longer than six months may be indicated as those without chronic knee pain initially post-TKR remain at risk of reverting to chronic knee pain 12 months post-TKR

Aims. This study aimed to determine the expression and clinical significance of a cartilage protein, cartilage oligomeric matrix protein (COMP), in knee osteoarthritis (OA) patients. Methods. A total of 270 knee OA patients and 93 healthy controls were recruited. COMP messenger RNA (mRNA) and protein levels in serum, synovial fluid, synovial tissue, and fibroblast-like synoviocytes (FLSs) of knee OA patients were determined using enzyme-linked immunosorbent assay, real-time polymerase chain reaction, and immunohistochemistry. Results. COMP protein levels were significantly elevated in serum and synovial fluid of knee OA patients, especially those in the advanced stages of the disease. Serum COMP was significantly correlated with radiological severity as well as measures of body composition, physical performance, knee pain, and disability. Receiver operating characteristic curve analysis unveiled a diagnostic value of serum COMP as a biomarker of knee OA (41.64 ng/ml, area under the curve (AUC) = 1.00), with a sensitivity of 99.6% and a specificity of 100.0%. Further analysis uncovered that COMP mRNA expression was markedly upregulated in the inflamed synovium of knee OA, consistent with immunohistochemical staining revealing localization of COMP protein in the lining and sub-lining layers of knee OA inflamed synovium. Most notably, relative COMP mRNA expression in knee OA synovium was positively associated with its protein levels in serum and synovial fluid of knee OA patients. In human knee OA FLSs activated with tumour necrosis factor-alpha, COMP mRNA expression was considerably up-regulated in a time-dependent manner. Conclusion. All results indicate that COMP might serve as a supportive diagnostic marker for knee OA in conjunction with the standard diagnostic methods. Cite this article: Bone Joint Res 2024;13(6):261–271

Introduction. Many patients with obesity experience knee pain. Excess body weight is a modifiable risk factor for osteoarthritis (OA) and weight loss is encouraged in patients with OA. Bariatric surgery could improve or limit the progression of these conditions through significant weight loss. The Oxford Knee Score (OKS) is a validated tool in the assessment of knee replacement surgery for OA. We present a novel application of the OKS to assess knee pain & function after weight loss surgery. The primary aim of this study was to assess whether there was a significant difference in mean OKS before and 24 months after weight loss surgery. Method. Eighteen female participants were included in this study. They underwent sleeve gastrectomy or Roux-en-Y gastric bypass. Patient demographics, body mass index (BMI) and OKS were collected pre- and 24 months post operatively. Result. There was an increase in the mean OKS from 31.8 (SD 11.8) pre surgery to 36.6 (SD 12.3) at 24 months. This was statistically significant (95% CI 0.99-10.5, p=0.02). Mean BMI reduced from 46.6 kg/m. 2. (SD 5.8) to 33.0 kg/m. 2. (SD 3.5). Conclusion. A significant improvement in mean OKS was seen after weight loss surgery. These findings demonstrate an improvement in knee pain & function with weight loss. This study contributes to a larger project evaluating the kinetic and kinematic changes to walking gait from weight loss

Aims. This study investigated the effects of transcatheter arterial embolization (TAE) on pain, function, and quality of life in people with early-stage symptomatic knee osteoarthritis (OA) compared to a sham procedure. Methods. A total of 59 participants with symptomatic Kellgren-Lawrence grade 2 knee OA were randomly allocated to TAE or a sham procedure. The intervention group underwent TAE of one or more genicular arteries. The control group received a blinded sham procedure. The primary outcome was knee pain at 12 months according to the Knee injury and Osteoarthritis Outcome Score (KOOS) pain scale. Secondary outcomes included self-reported function and quality of life (KOOS, EuroQol five-dimension five-level questionnaire (EQ-5D-5L)), self-reported Global Change, six-minute walk test, 30-second chair stand test, and adverse events. Subgroup analyses compared participants who received complete embolization of all genicular arteries (as distinct from embolization of some arteries) (n = 17) with the control group (n = 29) for KOOS and Global Change scores at 12 months. Continuous variables were analyzed with quantile regression, adjusting for baseline scores. Dichotomized variables were analyzed with chi-squared tests. Results. Overall, 58 participants provided questionnaire data at 12 months. No significant differences were found for the primary and secondary outcomes, with both groups improving following the procedure. At 12 months, KOOS pain scores improved by 41.3% and 29.4% in the intervention and control groups, respectively. No adverse events occurred. Subgroup analysis indicated that the complete embolization group had significantly better KOOS Sports and Recreation, KOOS Quality of Life, and Global Change scores than the control group; 76.5% of participants who received complete embolization reporting being moderately or much better compared to 37.9% of the control group. Conclusion. TAE might produce benefits above placebo, but only when complete embolization of all genicular arteries is performed. Further comparative studies are required before definitive conclusions regarding the effectiveness of TAE can be made. Level of evidence: I. Cite this article: Bone Jt Open 2023;4(3):158–167

Introduction. Up to 15 % of patients report anterior knee pain (AKP) after a total knee arthroplasty (TKA). The correlation of radiographic patellar measurements and post-operative AKP remains controversial. The purpose of this study was to determine whether any radiographic measurements can predict anterior knee pain after TKA. Methods. We performed a retrospective analysis of data on 343 patients who underwent a primary unilateral TKA between 2009–2012 at a single institution. Post-operative radiographs were evaluated with standing anteroposterior, lateral, and merchant views. Radiographic assessment was performed to assess posterior offset, Insall Salvati ratio, Blackburne, PP angle, Patella thickness, Congruence angle, Patella tilt, and patella displacement. Clinical function was assessed by the Kujala anterior knee pain scale at a minimum of 5 years. Patients were asked if they currently had anterior knee pain post-operatively by responding “yes” or “no.” There were 264 females and 79 males; the mean age at surgery was 64.2 ± 9.7 (range, 42–92 years) years; the mean BMI 31±5.8 kg/m. 2. (range, 18.8–49 kg/m. 2. ). Results. Of the 343 patients, 46 patients (13.4%) patients suffered persistent AKP at a minimum 5 years follow-up. Radiographic measurements were performed. Although we had large variations in congruence angle, patellar tilt and patellar displacement, these variations had no correlation with anterior knee pain (p=0.885). We were not able to detect statistical significance among clinical outcome Kujala score and patient reported AKP (p=0.713) at minimum 5 year follow-up. Discussion. Persistent anterior knee pain is troubling to patients and surgeons. Clinicians often get concerned when they see variability in these radiographic findings. Our findings suggest that variations in radiographic parameters do not predict anterior knee pain following total knee replacement surgery. For figures, tables, or references, please contact authors directly

Our purpose was to evaluate the incidence of anterior knee pain after ACL reconstruction and the associated affecting factors. The study assessed 50 ACL reconstructed knees: 29 males and 21 females. The age at surgery was from 14 to 39 years old, with 23.7 years old on the average. The ACL injury was unilateral in all cases, and the normal side was defined as the control. We treated chronic ACL-deficient knees by reconstruction of the ligament through a limited arthrotomy using one-third of the patellar tendon (BTB) with the Kennedy LAD as a graft. Anterior knee pain was classified into 4 group: absent, trace-mild, moderate, and severe. We evaluated the height of the patella, knee extension strength, anterior laxity, leg rotation, Lysholm score, and loss of extension. Anterior laxity and leg rotation were measured by a three-dimensional analyzer. Ten of the fifty knees (20%) had anterior knee pain. Knee extension strength (reconstructed side/control side) was 71.1% in the cases with anterior knee pain and 84.2% in the cases without anterior knee pain. A significant difference was found between these values. Regarding leg rotation, 4 knees showed normal leg rotation (physiological screw home movement) in the cases with anterior knee pain, compared to 31 knees in the cases without anterior knee pain. There was a significant difference in the incidence of anterior knee pain between the cases with normal leg rotation and the cases without. Other factors failed to show any significant correlation. In this study, knee extension strength and leg rotation had a correlation with anterior knee pain

Retrograde nailing of femoral shaft fractures has been a routine trauma practice option for approximately five years and may be technically advantaged in many situations. Earlier review of our antegrade experience revealed that 30% of standard nails are recognized to frequently cause pain (30%) and/or heterotopic ossification at the hip; knee pain of unclear etiology was found frequently as well (13%). This review of our preliminary experience with retrograde nails found a 30% frequency of nonspecific knee pain complaints at a mean of thirty-four months. No ectopic ossification was seen and no nails had been removed. The purpose of this study was to review the experience of patients who have undergone retrograde femoral nailing with regard to possible knee pain complaints. Chart and imaging records were reviewed retrospectively. Patients were contacted and interviewed by telephone to determine late pain complaints. From January 2000 through February 2002, eighteen patients were treated for twenty-two femoral shaft fractures. The group included ten males and and eight females of mean age 54.5 years (range, nineteen to ninety years). Treatment was with Synthes retrograde femoral nails, reamed and statically locked, inserted under fluoroscopic control on a radiolucent table using a Tenet™ leg holder. At thirty-four months, all fractures had healed primarily with no appreciable malalignment, no infections and no nonunions. No intraarticular free bodies or ectopic ossification were seen. Eleven patients were asymptomatic with regard to the index injured extremity. Five had mild to moderate pain, generally localized anteriorly, without associated articular symptoms and not requiring any analgesia. Two had severe symptoms of diffuse knee pain with radiographic degenerative changes noted, but these were cases with associated complex tibial plateau fractures to account for it. Even eliminating these two patients, fully five of sixteen patients (30%) without associated periarticular trauma at the knee had mild to moderate nondisabling anterior knee pain complaints after retrograde femoral nailing. The frequency of anterior knee pain complaints after retrograde femoral nailing is significant. Previous authors have found knee pain complaints in 27–29% of cases. We found no evidence of articular derangement in our patients undergoing retrograde femoral nailing in the absence of associated periarticular trauma at the knee, we confirm a 30% frequency of nonspecific knee pain complaints persisting at almost three years after injury. Patients should be made aware that, at intermediate-term follow-up, mild to moderate knee pain may be a result of this fracture treatment

There is a recognised incidence of anterior knee pain following Anterior Cruciate Ligament (ACL) reconstruction using a patella tendon autograft. This study examined two group of patients both pre ACL ligament reconstruction and post ACL reconstruction using patella tendon grafts to define if anterior knee pain is a result of patella tendon harvest or a primary consequence of an ACL injury. The two groups of patients were best matched for age, sex and physical activity. The pre-operative group of twenty-five patients had a confirmed ACL rupture and exhibited symptoms of instability requiring an ACL reconstruction. The operative group of twenty-five patients were a minimum of a year post operation. The graft was harvested by an open procedure and the graft bone blocks were secured with interference screws. The patients’ anterior knee pain score was assessed using the Shelbourne scoring system that evaluates knee function in relation to anterior knee pain using five parameters. The maximum score is 100. The scores were compared using the unpaired student test. There was no significant age difference between the two groups, preoperative group age 32. 2 years (range 22 to 46) and postoperative age 34. 8years (range 19 to 48). The mean anterior knee pain score for the preoperative group was 71. 6 (49 to 100), the postoperative group was 77. 7 (45 to 100), this was not significantly different. We found no significant difference in knee function due to anterior knee pain between the two groups. Studies have shown significant anterior knee pain following hamstring reconstruction (Spicer). This study shows anterior knee pain in the ACL deficient knee is present prior to surgery. We conclude that patella tendon autografts produce no significant incidence of anterior knee pain post surgery

Introduction. A comprehensive met-analysis of anterior knee pain post intramedullary nailing of the tibia was performed by Katsoulis et al in 2006. The principle findings were that 47.4% of patients had anterior knee pain at 2 years post tibial nailing. Worse results were found following a patella tendon splitting approach when compared with a medial para-patellar tendon approach. These conclusions were drawn from 20 studies including 1460 patients. Currently both approaches to the proximal tibia for nailing are used at JCMH Blanchardstown. A retrospective study was performed to compare the results of tendon splitting and tendon sparing approaches to tibial nails and to compare the results of JCMH with those stated in literature. Method. Patients who underwent tibial nailing in 2007 and 2008 were identified using the hospital coding system. Those patients who were treated under the care of Mr Kenny had a medial para-tendinous approach and those treated the care of Mr O'Flanagan and Mr Keogh had a tendon splitting approach. Apart from the approach the nailing technique using the Trigen Knee Nail and the post operative physiotherapy protocol were identical. Follow up included questions regarding knee pain and return to previous function. Specifically: Knee pain that affects daily life, Knee pain on kneeling, Knee pain on ascending or descending stairs, Return to work and Return to sports or active hobbies. Results. 61 patients were treated with intra-medullary nailing between 2007 and 2008 43 were available for follow for the purposes of this study (70 %). 25 had nails inserted via a tendon splitting approach and 18 via a tendon sparing approach. Only 5% of patients had knee pain that affected daily life, 16 % had pain on kneeling, 90% of patients who were previously at work returned to work and 75% of patients who were previously engaged in sports were able to return to these activities. Discussion. These results are significantly better than the figures stated in literature in terms of knee pain, return to work and sports. There was no significant difference between the 2 approaches to the tibia again in contradiction of available literature

Total knee arthroplasty (TKA) is one of the most common orthopaedic operations performed worldwide and it is largely successful in pain relief and functional recovery. However, when pain persists post-operatively the thorough evaluation must be instituted. Extra-articular causes of knee pain include; hip pathology, lumbar spine degenerative disease or radicular symptoms, focal neuropathy, vascular disease, and chronic regional pain syndrome. Intra-articular causes of knee pain: infection, crepitation/clunk, patella osteonecrosis, patella mal-tracking, soft tissue imbalance, malalignment, arthrofibrosis, component loosening, implant wear, ilio-tibial band irritation, and bursitis. Other causes of pain to rule out are component overhang with soft tissue irritation, recurrent hemarthrosis secondary to synovial impingement or entrapment, non-resurfaced patella, and metal sensitivity. A careful history may reveal previous knee surgeries with delayed healing or prolonged drainage, chronology of sign and symptoms, co-morbid medical conditions, jewel or metal sensitivity. Physical exam should help with specific signs in the operated knee. Targeted local anesthetic blocks are helpful and response to lumbar sympathetic blocks determines presence of CRPS. Lab tests are important: ESR, CRP, WBC, aspiration with manual cell count and diff, leucocyte esterase dipstick, RA titers, metal derm patch testing, nuclear scans, CT best for rotational malalignment, and MARS MRI. More recently patient satisfaction as an outcome measure has shown TKA results not satisfactory in 11- 18% of patients. A discordance of patient vs. surgeon satisfaction exists so the following factors may help improve this: correct patient selection, establishing and correlating surgeon-patient expectations, peri-operative optimization of patient co-morbidities to help avoid preventable complications, use of pre-operative and post-operative pathways. Satisfaction rates can best be improved by addressing the previous points with patients prior to TKA surgery

TKA is one of the most common orthopaedic operations performed worldwide and it is largely successful in pain relief and functional recovery. However, when pain persists post-operatively the thorough evaluation must be instituted. Extra-articular causes of knee pain include; hip pathology, lumbar spine degenerative disease or radicular symptoms, focal neuropathy, vascular disease, and chronic regional pain syndrome. Intra-articular causes of knee pain: infection, crepitation/ clunk, patella osteonecrosis, patella mal-tracking, soft tissue imbalance, malalignment, arthrofibrosis, component loosening, implant wear, ilio-tibial band irritation, and bursitis. Other causes of pain to rule out are component overhang with soft tissue irritation, recurrent hemarthrosis secondary to synovial impingement or entrapment, non-resurfaced patella, and metal sensitivity. A careful history may reveal previous knee surgeries with delayed healing or prolonged drainage, chronology of sign and symptoms, co-morbid medical conditions, jewel or metal sensitivity. Physical exam should help with specific signs in the operated knee. Targeted local anesthetic blocks are helpful and response to lumbar sympathetic blocks determines presence of CRPS. Lab tests are important: ESR, CRP, WBC, aspiration with manual cell count and diff, leukocyte esterase dipstick, RA titers, metal derm patch testing, nuclear scans, CT best for rotational malalignment,, and MARS MRI. More recently patient satisfaction as an outcome measure has shown TKA results not satisfactory in 11 – 18% of patients. A discordance of patient vs. surgeon satisfaction exists so the following factors may help improve this: correct patient selection, establishing and correlating surgeon-patient expectations, peri-operative optimisation of patient comorbidities to help avoid preventable complications, use of pre- and post-operative pathways. Satisfaction rates can best be improved by addressing the previous points with patients prior to TKA surgery

Anterior knee pain is a frequent complaint of dissatisfied total knee arthroplasty patients. We hypothesize that the need to use the extensor mechanism to stabilise the knee during activity is a cause of anterior knee pain. Studies have shown that TKA patients often walk with a “quadriceps avoidance” gait, which may explain the phenomenon of anterior knee pain. Most TKA prostheses are designed to allow AP motion. This feature in knee implant design is to prevent the “kinematic conflict” that was predicted with the crossed four-bar-link model of knee motion, which holds that progressive posterior contact of the femur on the tibia (rollback) with flexion was obligatory for knee range of motion. It has been stated that preventing this motion overly “constrained” the knee and could lead to loosening and wear. Paradoxical motion has been seen with video fluoroscopy in knees after TKA. This motion is an anterior translation of the femur on the tibia early in knee flexion and is called paradoxical because it occurs opposite to the expected rollback. In fact, paradoxical motion is a consequence of the “unconstrained” articulation of the femoral component on the tibial component. During gait, just after heel strike as the foot is assuming a flat position on the floor, there is a significant vector of force from posterior to anterior. This vector has been calculated as 33% of body weight for walking at normal speed and could lead to a significant displacement of the femur forward on the tibia. It is countered by 1) the slope of the proximal tibia; 2) the articulation of the femur in the concavity of the tibial (with the firmly attached meniscus that deepens the concavity) on the medial side; and 3) the body mass vector combined with that of the contracting quadriceps. If a total knee prosthesis allows the femur to move forward, the posterior-to-anterior force just after heel strike acts to move the femur forward on the tibia (paradoxical motion). The patient, in an attempt to stabilise the knee, uses increased quadriceps contraction to prevent the forward motion of the femur. The forces required are significant and are not only found in the patella-femoral articulation but all through the retinaculum that covers the anterior part of the femur. As the extensor mechanism tires, patients begin using a quadriceps avoidance gait to adapt to the weakening extensor, and after a period of activity, the stress on the retinaculum leads to pain. AP stability can be improved through implant design by preventing AP motion through conformity of the femoral and tibial components. We have used a medially conforming ball-in-socket prosthesis as a revision component for patients with anterior knee pain, and have achieved resolution of the pain. Patients demonstrate a “posterior sag” at approximately 20 degrees of flexion (the degree of flexion that has the maximum posterior-to-anterior force during gait). When treated with a brace appropriate for stabilisation of the knee after PCL reconstruction, patients experienced a marked decrease in symptoms and this predicts a good result from revision surgery

From October 2005 to March 2014, we performed 46 arthroscopic surgeries for painful knee after knee arthroplasty. We excluded 16 cases for this study such as, unicompartmental knee arthroplasty, infection, patellar clunk syndrome, patellofemoral synovial hyperplasia, aseptic loosening, and follow-up period after arthroscopic surgery less than 6 months. Thirty cases matched the criteria. They had knee pain longer than 6 months after initial total knee arthroplasty (TKA), they had marked tenderness at medial and/or lateral tibiofemoral joint space, and also they complained walking pain with or without resting pain. Twenty one cases had initial TKA at our institute. In consideration of total number of TKA (n=489) in the period at our institute, incident rate of painful knee after initial TKA was 4.3%. Of 30 cases, 3 cases were male, and 27 cases were female. Types of implant were 4 in cruciate retaining type, 1 in cruciate substituting type, and 25 in posterior stabilized type. Age at the arthroscopy was 72 years old (51–87 years old), and period form initial TKA to pain perception was 18 months(1 – 144 months), and period from initial TKA to arthroscopic surgery was 29 months (6 – 125 months), and follow-up period after arthroscopy was 36 months (6 – 93 months). All arthroscopic debridement were performed through 3 portals, anteromedial, anterolateral, and proximal superomedial portal. Scar tissue impingements more than 5 mm wide were found in 87% of the cases both medial and lateral femorotibial joint spaces. Infrapatellar fat pad were covered with whitish scar tissue in all cases, and the scar tissue were connecting with the scar tissue which found at medial or lateral femorotibial joint spaces. We removed all scar tissue with motorized shaver or punches. At final follow-up, complete pain free in 63%, marked improvement in 3%, half improvement in 20%, slight improvement in 3%, and no change in 10% of the cases. Previously in the literatures, two reasons of the pain after total knee arthroplasty had been reported, patellar clunk syndrome, and patellar synovial hyperplasia. All cases reported this study had marked tenderness at tibiofemoral joint space. It was difficult to explain the tenderness by previously reported pathological mechanisms. We had to find another pathological mechanism to explain the pain of our cases. Painful knee due to scar tissue formation known as “infrapatellar contracture syndrome” after anterior cruciate ligament reconstruction surgery was previously reported. We hypothesized similar scar tissue formation should occur after TKA that caused painful knee. Continuity of the solid scar tissue between infrapatellar fat pad with the scar tissue at tibiofemoral joint space should be the cause of impingement at femorotibial joint even small size of scar tissue. From this study, we have to recognize that painful knee after TKA is not infrequent complication. And, if we could deny infection, and aseptic loosening in painful knee after TKA, arthroscopic debridement was good option to solve the pain. We could expect improvement of the pain more than half in 87% of cases

Purpose: A relationship between vastus medialis oblique (VMO) strength and anterior pain and disability has been suggested. A biomechanical protocol was used to access the deficiency of the quadriceps muscles in patients with anterior knee pain. Methods and Results: A biomechanical evaluation was conducted on 54 patients with anterior knee pain (34 females and 20 males). All patient x-rays were normal through interpretation by a blinded radiologist. A Kistler force plate, a VICON motion analysis system and surface electromyography were used to quantify biomechanical function during isometric, walking and squatting exercises. For 42 of the 54 (78%) subjects, during isometric and walking exercises we observed that activation of the VMO, rectus femoris (RF) and vastus lateralis (VL) muscles of the symptomatic leg was not significantly different from those of the asymptomatic leg (p< 0.01). However, for 31 patients (57%) during the eccentric phase of the squat exercises, the symptomatic leg presented with high activation of VL compared to VMO and RF (p< 0.01). During the concentric phase, 45 patients (83%) presented with higher activation of the VL compared to the VMO. Conclusion: VMO activity during squatting for the symptomatic patient with anterior knee pain leg differs fundamentally during walking and isometric exercise compared to squatting tasks. Moreover, the relative contribution of the VL compared to the VMO during the eccentric phase of the squat exercises was different to those recorded during the concentric phase. Therefore, we suggest that maximal isometric and or isokinetic exercises are not sufficient to access the quadriceps function in relation to anterior knee pain. A thorough biomechanical assessment, including functional testing to reproduce the patient’s pain and locate the nature of the symptoms is suggested

Introduction. Special high-flexion prosthetic designs show a small increase in postoperative flexion compared to standard designs and some papers show increased anterior knee pain with these prosthesis. However, no randomised controlled trails have been published which investigate difference in postoperative complaints of anterior knee pain. To assess difference in passive and active postoperative flexion and anterior knee pain we performed a randomized clinical trial including the two extremes of knee arthroplasty designs, being a high flex posterior stabilized rotating platform prosthesis versus a traditional cruciate retaining fixed bearing prosthesis. We hypothesised that the HF-PS design would allow more flexion, due to increased femoral rollback with less anterior knee pain than the CR design. We specifically assessed the following hypotheses:. Patients have increased flexion after HF-PS TKA compared to CR TKA, both passive and active. Patients show an increased femoral rollback in the HF-PS TKA as compared to the CR TKA. Patients receiving a HF-PS TKA design report reduced anterior knee pain relative to those receiving the CR TKA. Methods. In total 47 patients were randomly allocated to a standard cruciate retaining fixed bearing design (CR) in 23 patients and to a high-flexion posterior stabilized mobile bearing design (HF-PS) in 24 patients. Preoperative and one year postoperative we investigated active and passive maximal flexion. Furthermore, we used the VAS pain score at rest and during exercise and the Feller score to investigate anterior knee pain. A lateral roentgen photograph was used to measure femoral rollback during maximal flexion. Results. The HF-PS did show a significantly higher passive postoperative flexion; 120.8° (SD 10.3°) vs. 112.0° (SD 9.5°) for the CR group (p=0.004). The active postoperative flexion, VAS-pain score and Feller score did not show significant differences between both groups. Sub analysis with the HF-PS group showed a higher VAS-pain for the patients achieving ≥130° of flexion; 30.5 (SD 32.2) vs. 12.2 (SD 12.5) (p=0.16). The rollback was significantly lower in the CR group compared to the HF-PS group; 4.4 (SD 3.0) vs. 8.4 (SD 2.1). Conclusion. The present study showed a significant higher passive flexion in the Posterior Stabilised-High Flexion mobile bearing compared to a Cruciate Retaining fixed bearing prosthesis. However, this difference disappeared when comparing active flexion. The difference in passive flexion was probably related to a significantly lower rollback causing impingement in the CR prosthesis. No difference in anterior knee pain was found between both groups. However, a suggestion is raised that achieving high-flexion might lead to more patellofemoral complaints/anterior knee pain

Aim: To assess the prevalence of anterior knee pain after intramedullary nailing of the tibia and its socioeconomic impact. Methods: A retrospective, study of 251 consecutive tibial intramedullary nailings in 248 patients, aged less than 60 years at the time of injury. The minimum follow-up period was five years and the patients were assessed using a questionnaire and the Lysholm knee score. Results: The mean follow-up was 7.9 years. Anterior knee sensory disturbance was reported by 58% of patients. Anterior knee pain (AKP) was reported by 47%. This interfered with activities of daily living in 37%, work in 36% and sport in 57%. Pain on kneeling was mild in 54%, moderate in 34% and severe 12%. AKP improved with time in 73% patients and became worse in 4%. The Lysholm score rated 41% knees as excellent, 19% as good, 26% as fair and 14% as poor. Eighty-six percent of the patients returned to work. The presence of anterior knee pain prevented return to previous work in 10%. The type of work performed before and after injury respectively were; sedentary 26%/29%, walking-based 20%/27%, manual 38%/37%, heavy manual 16%/7%. Conclusions: Anterior knee pain persisted in 47% of patients after intramedullary nailing of the tibia. There was some decrease in symptoms with time and the majority of patients were able to return to work. However, anterior knee pain caused a significant disability in a small number and all patients should be warned of this problem before this type of surgery

Aims: Anterior knee pain is a common complaint of mixed aetiology, and in many cases no demonstrable cause is identified. For patients with persistant anterior knee pain, tibial tubercle transfer (TTT) can be a surgical option. The aim of this study is to assess the effectiveness of TTT for chronic anterior knee pain resistant to conservative treatment. Method: All patients with arthroscopically proven Chondromalacia patellae (CMP) without clinical evidence of patella instability, who have failed to respond to conservative treatment such as physiotherapy were included in the trial. They underwent TTT with a modified Fulkerson technique and then routine post-operative care with a cricket pad splint for 2–4 weeks. Pre and post-operative scores were obtained using a Kujala patello-femoral score, a visual analogue score for pain and a patient satisfaction score. The Outerbridge grading was used to score the severity of CMP at arthroscopy. Results: There were 50 TTT’s followed up (7 staged bilaterals) with a mean follow up of 32.4 months (5–88 months). There were significant improvement in the pre-operative and post-operative Kujala (p> 0.001) and visual analogue pain scores (p> 0.001). Of the 50 TTT’s 70% had an excellent or good result and 30% a fair or poor result. Moreover 76% claimed that they would have the same operation again for their condition. There was no significant correlation between Outerbridge grading and post-operative outcome. Complications include late anterior knee pain (10 cases), superficial wound infection (1 case), non-union of osteotomy (1 case) and tuberosity fracture (1 case). Conclusion: Anteromedial tibial tubercle transfer is a reliable and effective treatment for peristant anterior knee pain

There is a lack of information about the association between patellofemoral osteoarthritis (PFOA) and both adolescent Anterior Knee Pain (AKP) and previous patellar dislocations. This case-control study involved 222 participants from our knee arthroplasty database answering a questionnaire. 111 patients suffering PFOA were 1:1 matched with a unicompartmental tibiofemoral arthritis control group. Multivariate correlation and binary logistic regression analysis was performed, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated. This analysis helps us assess the effect of both variables whilst adjusting for major confounders, such as previous surgery and patient-reported instability. An individual is 7.5 times more likely to develop PFOA if they have suffered adolescent AKP (OR 7.5, 95% CIs 1.51–36.94). Additionally, experiencing a patellar dislocation increases the likelihood of development of PFOA, with an adjusted odds ratio of 3.2 (95% CIs 1.25–8.18). A 44-year difference in median age of first dislocation was also observed between the groups. This should bring into question the traditional belief that adolescent anterior knee pain is a benign pathology. Patellar dislocation is also a significant risk factor. These patients merit investigation, we encourage clinical acknowledgement of the potential consequences when encountering patients suffering from anterior knee pain or patellar dislocation

Whereas thermography has already been used as an assessment of disease activity in some kinds of inflammatory arthritis, it is a new method for objektive pain evaluation in patients with joint prosthesis. To our knowledge, no study has tested the correlation between increase of temperature and anterior knee pain with total knee prosthesis yet. Thirteen patients were included in this study who suffered from anterior knee pain of the retinaculum patellae with total knee prosthesis. The patients were asked to walk 3 km before entering a room which was cooled down to 20 degrees Celsius. A black 1 cm times 4.5 cm square stripe was attached on the diameter of the patella and the patients rested for 20 minutes to cool down before thermographic fotos were taken from 90 degrees, 45 degrees, frontal medial and lateral. The evaluation of temperature difference of each side was performed by marking a 1cm times 2cm square field rectangular around the black stripe and comparing it with a reference point of the same size 3 cm distal of the field. The patients were compared with thirteen others, not suffering from anterior knee pain. Statistical analysis was performed using a t- test and a p value < 0.05 was considered to be significant. The temperature differences between the rectangular field and the reference point increased significantly on the medial (p= 0.00037) or lateral (p= 0.000002) pain side of the knee. The thirteen knees with knee pain had significantly higher temperature differences between medial and lateral temperature differences, than the knees without knee pain. We demonstrate a significant correlation between anterior knee pain and an increase of superficial skin temperature around the retinaculum patellae. To our knowledge, this is the first report of an objective assessment of pain of the retinaculum patellae with total knee prosthesis

Aim. To determine if the location and pattern of knee pain as described by the patients using the knee pain map was comparable with the intra articular pathology found on arthroscopy as well as to facilitate diagnosis based on pain. Methods. There were fifty five consecutive patients with acute and chronic knee pain participating in the study and they subsequently underwent arthroscopy of the knee joint as therapeutic or diagnostic procedure in day surgery. Those patients with extra articular pathologies, referred pain hip, back and foot were excluded from the study. All the participants were consented for the study; subjective data was recorded on the standardised knee pain map that included visual analogue pain scale preoperatively on the day of admission for arthroscopy. The findings of the arthroscopy including EUA were recorded on the on standard arthroscopy forms used in our department by the operating surgeon. Results. Patients on the knee pain map most often recorded sharp/stabbing pain (72%), followed by diffuse dull pain (14.5%), mixed dull and sharp pain (10 %) and burning pain (3.5%). 82% of the localising pain pattern recorded on the knee pain map by the patients corresponded to the intra articular lesion found during knee arthroscopy. 18 % of the pain mapping location and pattern was not very specific to the intrarticular arthroscopic lesions. Conclusions. The results from our study indicate, majority of the patients could map the knee pain location and pattern correlating to the knee arthroscopic findings. Furthermore, the knee pain mapping can be used as a reliable tool to assist the clinician to determine the specific knee pain patterns correlating with intra-articular lesion