Associations amongst dynamic knee stiffness during gait, quadriceps stiffness, and the incidence of knee osteoarthritis over 24 months: a cohort study with a mediation analysis.

BACKGROUND: Decreased strength and increased stiffness of the quadriceps have been associated with a higher risk of developing knee osteoarthritis (OA) in elders. Dynamic joint stiffness (DJS) represents collective resistance from active and passive knee structures for dynamic knee motions. Elevated sagittal knee DJS has been associated with worsening of cartilage loss in knee OA patients. Altered quadriceps properties may affect DJS, which could be a mediator for associations between quadriceps properties and knee OA. Hence, this study aimed to examine whether DJS and quadriceps properties would be associated with the development of clinical knee OA over 24 months, and to explore the mediation role of DJS in associations between quadriceps properties and knee OA. METHODS: This was a prospective cohort study with 162 healthy community-dwelling elders. Gait analysis was conducted to compute DJS during the loading response phase. Quadriceps strength and stiffness were evaluated using a Cybex dynamometer and shear-wave ultrasound elastography, respectively. Knee OA was defined based on clinical criteria 24 months later. Logistic regression with generalized estimating equations was used to examine the association between quadriceps properties and DJS and incident knee OA. Mediation analysis was performed to explore the mediation role of DJS in associations between quadriceps properties and the incidence of knee OA. RESULTS: A total of 125 participants (65.6 ± 4.0 years, 58.4% females) completed the 24-month follow-up, with 36 out of 250 knees identified as clinical knee OA. Higher DJS (OR = 1.86, 95%CI: 1.33-2.62), lower quadriceps strength (1.85, 1.05-3.23), and greater quadriceps stiffness (1.56, 1.10-2.21) were significantly associated with a higher risk of clinical knee OA. Mediation analysis showed that the DJS was not a significant mediator for the associations between quadriceps properties and knee OA. CONCLUSIONS: Higher sagittal knee dynamic joint stiffness, lower quadriceps strength, and greater quadriceps stiffness are potential risk factors for developing clinical knee OA in asymptomatic elders. Associations between quadriceps properties and knee OA may not be mediated by dynamic joint stiffness. Interventions for reducing increased passive properties of the quadriceps and knee joint stiffness may be beneficial for maintaining healthy knees in the aging population.

Increased symptoms of stiffness after opening-wedge high tibial osteotomy are associated with worse postoperative knee function outcomes and lower patient satisfaction rate.

BACKGROUND: Symptoms of knee stiffness after open wedge high tibial osteotomy (OW-HTO) can significantly affect surgical effectiveness, but no studies have reported risk factors for knee stiffness after OW-HTO. METHODS: Patients treated with OW-HTO for the first time between 2018 and 2021 were included. Data were collected on patient demographics, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short Form (SF) 12 scores, hip-knee-ankle angle (HKA) and patient satisfaction before and after surgery. Patients with worse WOMAC stiffness scores at 1 year were defined as the 'increased stiffness' group and the other cohort as the 'non-stiffness' group. The primary outcome of the study was to compare postoperative knee function scores (WOMAC and SF-12), HKA and patient satisfaction rate between the two groups. The secondary outcome was the use of logistic regression to analyze independent predictors of increased postoperative stiffness symptoms. RESULTS: At 1 year postoperatively, 95 (11.3%) patients had a significant increase in stiffness. Patients had significantly (p < .001) less improvement in pain, function, and total WOMAC scores, and SF-12 score than those in the non-stiffness group (n = 745). However, the differences in WOMAC and SF-12 scores in increased stiffness group at 1 year post-operatively were statistically significant (p < .001) compared to the non-stiffness group. There was no statistically significant difference in HKA in the increased stiffness group (172.9° ± 2.3°) compared to non-stiffness group (173.4° ± 2.6°) at 1 year postoperatively (p = .068). Patient satisfaction was significantly lower in the increased stiffness group (p < .001). Logistic regression analysis showed that diabetes (odds ratio (OR) 1.809, p = .034) and preoperative WOMAC stiffness score of 44 or less (OR 4.255 p < .001) were predictors of increased stiffness. CONCLUSIONS: Patients with increased stiffness after OW-HTO had worse functional outcomes and lower patient satisfaction rates and patients at risk of being in this group should be informed pre-operatively.

Arthroscopic Arthrolysis of Knee: Timing, Technique and Results.

Aim: To evaluate the functional outcomes of patients undergoing arthroscopic arthrolysis of the knee and find the ideal timing for arthrolysis to achieve maximum range of motion (ROM) of the knee. Methods: All patients who underwent arthroscopic arthrolysis for post-operative joint stiffness following surgery for injuries around knee joint at a tertiary care centre from 2009 to 2023 were included in this study. The patients' details such as primary injury, time interval between the index surgery and arthrolysis, improvement in knee range of ROM and Lysholm score from prior to arthrolysis to last follow-up post arthrolysis were retrieved from hospital database and analysed. Results: Total of 42 patients who underwent arthroscopic arthrolysis of knee from 2009 to 2023 were included in this study. Follow-up range was 6 months to 6 years. ROM after arthrolysis significantly improved in the early and delayed arthrolysis groups as compared to late arthrolysis groups (mean 126.25 and 115.62 vs 106.3, p < 0.05). Patients treated with early arthroscopic arthrolysis (within 3 months) showed significant increase in post operative Lysholm score compared to other groups (p < 0.05). ROM of 120° and beyond was achieved in 75% of cases in early arthrolysis group compared to 62.8% and 39% in delayed and late arthrolysis group (p < 0.05). Conclusions: Arthroscopic arthrolysis done within 6 months (with maximum effect when done within 3 months) after the primary surgery leads to significant improvement in ROM and functional scores as compared to those with late arthrolysis group.

Risk factors for failure of manipulation under anesthesia in posttraumatic knee stiffness.

OBJECTIVES: To determine the proportion of patients who fail manipulation under anesthesia (MUA) as a treatment for posttraumatic knee stiffness and determine the risk factors for MUA failure. METHODS: A retrospective cohort study was performed at a level I trauma center. We identified 213 knees in 199 patients with arthrofibrosis treated by MUA within 1 year of injury from 2007 to 2020. The primary outcome was MUA failure as defined by need for repeat MUA or surgical release after MUA. Multivariable logistic regression was used to determine the association between MUA failure and potential risk factors. RESULTS: Overall, 111 knees (52%) failed treatment with MUA. An association was demonstrated between MUA failure and delay in treatment >90 days after injury (OR 3.6, p < 0.01), neurologic injury (OR 2.2, p = 0.02), and pre-procedure knee flexion <45° (OR 1.9, p < 0.01). The rate of failure for knees with no risk factors was 0% (0 of 14), 37% for knees with one risk factor (27 of 73), and 67% (84 of 126) for knees with two or more risk factors. CONCLUSION: For patients whose MUA is delayed beyond 90 days postinjury, pre-manipulation knee flexion is <45°, or those with associated neurologic injury; odds of MUA failing to correct posttraumatic arthrofibrosis are significantly increased. The likelihood of obtaining adequate range of motion (ROM) with MUA alone is lower than reported in other populations, with a higher likelihood of being treated with surgical release or additional MUA to attempt to obtain adequate ROM.

Role of non-ASA VTE prophylaxis in risk for manipulation following primary total knee arthroplasty.

INTRODUCTION: Stiffness and decreased range of motion frequently lead to hindrance of activities of daily living and dissatisfaction follow total knee arthroplasty (TKA). This study aims to evaluate the effect of non-aspirin (ASA) chemoprophylaxis and determine patient-related risk factors for stiffness and need for manipulation under anesthesia (MUA) following primary TKA. MATERIALS AND METHODS: A review of all patients undergoing primary TKA from 2013 to 2019 at a single academic orthopedic hospital was conducted. The primary outcome measure was MUA performed post-operatively. Chi-square analysis and Mann-Whitney U test were used to determine statistically significant relationships between risk factors and outcomes. Significance was set at p < 0.05. Univariate logistic regression was performed to control for identified independent risk factors for MUA. RESULTS: A total of 11,550 patients undergoing primary TKA from January 2013 to September 2019 at an academic medical center were included in the study. Increasing age and Charlson Comorbidity Index were associated with statistically significant decreased odds of MUA (0.93, 95% CI: 0.92-0.94, p < 0.001, OR 0.71, 95% CI 0.63-0.79, p < 0.001). Active smokers had a 2.01 increased odds of MUA (OR 2.01, 95% CI 1.28, 3.02, p < 0.001). There was no significant difference in rates of MUA between ASA and non-ASA VTE prophylaxis (p 0.108). CONCLUSIONS: Younger age, lower CCI, and history of smoking are associated with a higher rate, while different chemical VTE prophylaxis does not influence rate of MUA after TKA. Arthroplasty surgeons should consider these risk factors when counseling patient preoperatively. Understanding each patients' risk for MUA allows surgeons to appropriately set preoperative expectations and reasonable outcome goals.

Understanding rates, risk factors, and complications associated with manipulation under anesthesia after total knee arthroplasty (TKA): An analysis of 100,613 TKAs.

BACKGROUND: Considering the growing adoption of technology-assisted total knee arthroplasties (TKA), previous database studies evaluating post-operative stiffness may be outdated. The present study aimed to: (1) evaluate the incidence of manipulation under anesthesia (MUA) after primary TKA; (2) determine independent risk factors for MUA; and (3) assess complications after MUA. METHODS: Primary TKAs, with at least 6-month follow-up, were identified from the Florida State Inpatient Database (January 2016-June 2018) and linked to outpatient records from the Florida State Ambulatory Surgery and Services Database. Multivariable regression analyses were performed to compare patient factors and complications (e.g., mechanical, non-mechanical, infectious) associated with MUA, while adjusting for baseline demographics, comorbidities, use of robotic- and computer-technologies, time to MUA (0-3, 3-12, or >12 months), and need for repeat MUA (one-time vs >1). RESULTS: The MUA rate was 2.8% (2821 of 100,613). Being younger, a woman, Black or Hispanic; having private or self-pay insurance; and conventional TKA were associated with significantly higher odds of undergoing MUA. Higher rates of mechanical complications and acute posthemorrhagic anemia were observed in the MUA cohort. Time to MUA, repeat MUA, and baseline demographics were not associated with complication rates among the MUA cohort. CONCLUSION: Overall, 1 in 36 patients underwent MUA after primary TKA. Several non-modifiable patient characteristics, such as Black or Hispanic race, female sex, and younger age were associated with an increased risk of MUA. However, technology-assisted TKA might help to decrease the risk of MUA.

Efficacy of non-operative treatment of patients with knee arthrofibrosis using high-intensity home mechanical therapy: a retrospective review of 11,000+ patients.

BACKGROUND: Recovery from knee surgery or injury can be hindered by knee arthrofibrosis, which can lead to motion limitations, pain and delayed recovery. Surgery or prolonged physical therapy are often treatment options for arthrofibrosis, but they can result in increased costs and decreased quality of life. A treatment option that can regain lost motion without surgery would help minimize risks and costs for the patient. The purpose of this study was to determine treatment efficacy of high-intensity home mechanical stretch therapy in patients with knee arthrofibrosis. METHODS: Records were reviewed for 11,000+ patients who were prescribed a high-intensity stretch device to regain knee flexion. Initial and last recorded knee flexion and days between measurements were available for 9842 patients (Dataset 1). Dataset 2 was a subset of 966 patients from Dataset 1. These 966 patients had separate more rigorous measurements available from physical therapy notes (Dataset 3) in addition to data from the internal database (Dataset 2). Within and between dataset statistics were calculated using t tests for comparison of means and Cohen's d for determination of effect size. RESULTS: All dataset showed significant gains in flexion (p < 0.01). Mean initial flexion, last recorded flexion and flexion gain were 79.5°, 108.4°, and 29.9°, respectively in Dataset 1. Differences between Datasets 2 and 3 had small effect sizes (Cohen's d < 0.17). The were no significant differences when comparing workers' compensation and non-workers' compensation patients. The average last recorded flexion for all datasets was above the level required to perform activities of daily living. Motion gains were recorded in under 60 days from device delivery. CONCLUSIONS: High-intensity home mechanical stretch therapy was effective in restoring knee flexion, generally in 2 months or less, and in avoiding additional surgery in severe motion loss patients regardless of sex, age, or workers' compensation status. We believe high-intensity stretching should be considered in any patient who is at risk for a secondary motion loss surgery, because in over 90% of these patients, the complications and costs associated with surgery can be avoided.

A Strong Correlation Between the Severity of Flatfoot and Symptoms of Knee Osteoarthritis in 95 Patients.

Objective: The purpose of this study is to assess the association between the presence and severity of flatfoot and symptoms of knee OA. Methods: 95 participants with knee OA were recruited from a patient cohort at a regional hospital. Symptoms of knee OA, including knee degeneration, femorotibial alignment, pain, stiffness and dysfunction were assessed using the Kellgren-Lawrence (K-L) grading system, femoral-tibial angle (FTA), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Participants were divided into groups with flatfoot (mild, moderate and severe) and without flatfoot based on the Clarke's angle. Linear regression and ordinal logistic regression were used for statistical analysis, as appropriate. Results: Having flatfoot was associated with a significantly increased risk of having a higher K-L grade (OR: 20.03; 95% CI, 5.88, 68.27; p < 0.001), smaller FTA (Beta: -2.96; 95% CI, -4.41, -1.50; p < 0.001), higher pain score (Beta: 0.47; 95% CI, 0.24, 0.69; p < 0.001) and greater loss of function (Beta: 0.25; 95% CI, 0.02, 0.48; p = 0.03). Severe grades of flat feet were associated with a higher K-L grade (OR: 0.19; 95% CI, 0.08, 0.44; p < 0.001), smaller FTA (Beta: 1.51; 95% CI, 0.66, 2.35; p = 0.001), higher pain score (Beta: -0.25; 95% CI, -0.39, -0.11; p = 0.001), greater stiffness (Beta: -0.24; 95% CI, -0.38, -0.09; p = 0.002) and greater loss of function (Beta: -0.27; 95% CI, -0.41, -0.14; p < 0.001). Conclusion: The results indicated that the severity of flattening is significantly associated with symptoms of knee OA. For the conservative management of knee OA, both flatfoot and its severity should be carefully considered.

Treatment of traumatic fibrous stiffness of the knee with a combination of arthrolysis and Ilizarov tech-nique / 中华创伤骨科杂志

Objective:To investigate the clinical efficacy and indications of arthrolysis plus Ilizarov technique in the treatment of traumatic fibrous stiffness of the knee.Methods:The clinical data were analyzed retrospectively of the 9 patients (10 knees) with traumatic fibrous stiffness who had been treated by arthrolysis plus Ilizarov technique from January 2012 to December 2020 at Department of Orthopaedics, Rehabilitation Hospital of National Research Center for Rehabilitation Technique Aids. There were 8 males and one female, aged from 15 to 42 years (average, 30.2 years). The left side was affected in 2 cases, the right side in 6 ones and bilateral sides in one. Their knee stiffness was all caused by injury around the knee. The time from injury to treatment ranged from 12 months to 38 years (average, 16.5 years). The admission examination revealed that the knee extension ranged from -40° to 0° and the knee flexion from -10° to 40°. Wearing time for the external fixator and incidence of complications were recorded; the ranges of knee motion were compared before and after treatment; the Qin Sihe criteria for postoperative limb deformity correction were used at the last follow-up to evaluate the curative efficacy.Results:The 9 patients were followed up for 20 to 78 months with an average of 35 months. The external fixators were worn for 14 to 200 days with an average of 78.4 days. During the traction period, pin tract reaction (3 holes) occurred in 2 patients with 3 knees, pin tract infection (2 holes) in 2 patients with 2 knees, the incision healed poorly in one patient, and no other complications occurred. The functional recovery of the knee was good at the last follow-up. The knee extension was 0°, insignificantly different from the preoperative value (-6.5°±12.9°) ( t=-1.591, P=0.146); the flexion angle was 70.0°±17.6°, significantly better than the preoperative value (15.0°±17.2°) ( t=-6.822, P< 0.001). According to the Qin Sihe postoperative criteria, the curative efficacy at the last follow-up was excellent in 7 knees and good in 3. Conclusion:In the treatment of traumatic fibrous stiffness of the knee, when the efficacy of simple arthrolysis is not good enough, a combination with Ilizarov technique can help improve the postoperative knee function and prevent severe complications.

Bidirectional associations of accelerometer measured sedentary behavior and physical activity with knee pain, stiffness, and physical function: The CARDIA study.

The objective was to examine bidirectional associations of accelerometer estimated sedentary time and physical activity with reported knee symptoms. Participants were 2,034 adults (mean age 45.3 ± 3.6 years, 58.7% female) from CARDIA. Generalized estimating equations for logistic regression and linear mixed regression models examined associations of accelerometer estimated sedentary time, light-intensity physical activity (LPA), and moderate-to-vigorous intensity physical activity (MVPA) at baseline (2005-06) with knee discomfort, pain, stiffness, and physical function (yes/no and continuous scores from short-form WOMAC function scale) at the 5- and 10-year follow-up exams. Linear regression models examined associations between knee symptoms at the 5-year follow-up with accelerometer estimates at the 10-year follow-up. Models were adjusted for confounders; individuals with comorbidities were excluded in sensitivity analyses. A 30 min/day increment in sedentary time at baseline was associated with lower odds of knee symptoms at the 5- and 10-year follow-up (OR: 0.95, 95% CI range: 0.92-0.98), while LPA and MVPA were associated with greater odds of knee symptoms (LPA OR range: 1.04-1.05, 95% CI range: 1.01-1.09; MVPA OR range: 1.17-1.19, 95% CI range: 1.06-1.32). Report of knee symptoms at the 5-year follow-up was associated with 13.52-17.51 (95% CI range: -29.90, -0.56) fewer minutes/day of sedentary time and 14.58-17.51 (95% CI range: 2.48, 29.38) more minutes/day of LPA at the 10-year follow-up, compared to those reporting no symptoms. Many associations were no longer statistically significant when excluding individuals with comorbidities. Findings support a bidirectional association of accelerometer estimated sedentary time and physical activity with knee symptoms across midlife.

Total Knee Arthroplasty Is Superior to Open Wedge High Tibial Osteotomy in Terms of Pain Relief for Patients With Osteoarthritis.

BACKGROUND: Globally, total knee arthroplasty (TKA) is widely performed on patients with osteoarthritis. Meanwhile, open wedge high tibial osteotomy (OWHTO) has garnered attention in our country as a joint-preserving procedure. This study aimed to retrospectively compare the postoperative clinical outcomes of TKA and OWHTO for patients with osteoarthritis. METHODS: We selected 94 patients (106 knees) who underwent OWHTO or TKA between 2013 and 2018, had complete clinical data, and were followed up for >2 years. Patients were classified into 2 groups depending on the procedure (TKA: n = 49; OWHTO: n = 45). Patients in the A (= arthroplasty) group were significantly older, with a worse range of motion (ROM) than those in the O (osteotomy) group. There were no significant differences regarding sex and body mass index between groups. Operative time, perioperative blood loss, knee ROM, and Japanese Knee Injury and Osteoarthritis Outcome Score (J-KOOS) were compared between the groups. RESULTS: Significant differences were found between the A and O groups regarding operative time (120 ± 27.2 vs 80.3 ± 23.3 minutes), perioperative blood loss (505.4 ± 271.8 vs 322.6 ± 196.1 mL), knee ROM (flexion; 123.4 ± 16.3° vs 133.7 ± 12.8°), and J-KOOS for pain (87.4 ± 12.5 vs 78.1 ± 15.2 points) and symptoms (86.6 ± 12.3 vs 79.1 ± 13.3 points). There were no significant differences regarding other J-KOOS subscales. CONCLUSIONS: OWHTO involved shorter operative times and less blood loss. However, the O group reported less pain relief. The A group represents an older, likely less active patient population. Therefore, OWHTO is a possible joint-preserving treatment options in younger active patients who may not be interested in arthroplasty.

Safety and efficacy of the modified Judet quadricepsplasty in patients with post-traumatic knee stiffness.

BACKGROUND: Knee stiffness is a challenging complication following complex fractures around the knee. Several treatment strategies have been described in the last decades, but clinical results and complication rates still remain as potential drawbacks. The aim of this study was to access the clinical outcomes and complications of the modified Judet quadricepsplasty following knee stiffness secondary to complex fractures around the knee. METHODS: A total of 11 patients presenting post-traumatic knee stiffness underwent modified Judet quadricepsplasty from 2014 to 2017. All procedures were performed by the same surgical team, and all patients followed the same postoperative pain control and rehabilitation protocols. No patients underwent medial approach for medial release. When necessary, medial release was performed through the lateral approach. Patients were evaluated using the Judet criteria for final range of motion after 1-year minimum follow-up. RESULTS: According to the Judet criteria, 4 patients (36.4%) presented excellent, 6 (54.5%) good, and 1 (9.1%) poor clinical outcomes. Blood transfusion was required in 5 patients (45.4%). No patients presented infection or wound dehiscence. CONCLUSIONS: Although quadricepsplasty is considered a high morbidity surgical procedure, our favorable functional outcomes with very low complication rates using this modified Judet quadricepsplasty confirmed safety and efficacy of this helpful surgical procedure for the challenge of post-traumatic knee stiffness. LEVEL OF EVIDENCE: Level 4 retrospective case series.

Treatment of posttraumatic patella osteomyelitis with MRSA infection and knee stiffness: a case report.

BACKGROUND: Posttraumatic patella osteomyelitis is rare, and the treatment of osteomyelitis remains to be challenging. Control of the infection commonly costs a long time, and it is easily to cause knee stiffness. In addition, there is no unified protocol for the treatment of knee stiffness. CASE PRESENTATION: We reported a case of posttraumatic patella osteomyelitis that successive infected with methicillin-resistant staphylococcus aureus (MRSA) after multiple surgeries. We successfully treated osteomyelitis by one-staged surgery, but the patient present knee stiffness after treatment. Thus Ilizarov external fixation system was further used to gradually adjust the mobility by exerting mechanical stress to the joint. After adjusting the frame under a scheduled plan, the patient successfully restored satisfactory knee function. CONCLUSIONS: Adequate debridement is the key to control infections of posttraumatic osteomyelitis. Control the infection of posttraumatic patella osteomyelitis by one-staged surgery is achievable and could shorten the knee immobilization period. When knee stiffness occurs, scheduled range of motion (ROM) adjustment using Ilizarov frame with hinges might be a safe and useful method to restore function.

Manipulation under Anaesthesia for Patient Reported Stiffness after Total Knee Arthroplasty in an Asian Population.

INTRODUCTION: Stiffness after Total Knee Arthroplasty (TKA) is a complication that decreases patient satisfaction. Patients in an Asian population have potentially different requirements of knee range of motion. The authors have encountered patients who complain of subjective stiffness post TKA who do not have a severely restricting range of motion (ROM). Some patients have persistent subjective stiffness and undergone Manipulation Under Anaesthesia (MUA). We look at their functional outcomes post MUA. MATERIALS AND METHODS: This is a retrospective study, including 48 patients from a single institution who underwent MUA for stiffness, separated into objective and subjective knee stiffness. Patients with subjective knee stiffness who underwent MUA had failed conservative management. ROM, Oxford Knee Scores (OKS), Knee Society Scores (KSS) and Short Form 36 (SF36) scores were compared at two years post MUA. RESULTS: The demographics of the two patient groups were similar. The time interval between index TKA and MUA was higher in the subjective knee stiffness group. Pre-MUA OKS, KS Function Score, KSS and SF36 scores were similar in both patient subgroups. There was no significant difference in the OKS, KSS or SF36 at two year follow-up. The proportion of patients in each group who achieved the Minimum Clinically Important Difference (MCID) improvement in the scores was also similar. CONCLUSIONS: Patients with subjective knee stiffness can achieve similar functional outcome improvements in Oxford and Knee Society Scores with MUA at two years follow-up.

Manipulation under anesthesia as a therapy option for postoperative knee stiffness: a retrospective matched-pair analysis.

INTRODUCTION: Due to demographic changes, total knee arthroplasty (TKA) is one of the most frequently performed orthopedic surgeries. Therapies for associated postoperative complications, such as postoperative knee stiffness (PKS), are becoming increasingly important. The aim of this retrospective matched-pair analysis was to evaluate mid-term-results following manipulation under anesthesia (MUA). MATERIALS AND METHODS: Fifty-one patients with PKS were evaluated and 51 matched-pair patients without PKS after primary TKA were chosen for the control group. In addition to the range of motion, the functionality was recorded by Knee Society Score (KSS), Western Ontario and Mc Masters Universities Osteoarthritis Index (WOMAC), and Short-Form-12 Questionnaire (SF-12). Experience of pain was mapped using a 10-point Numeric Rating Scale (NRS), and the analgesic requirement was mapped using the WHO step scheme. A final follow-up examination was conducted approximately three years after TKA. To evaluate potential risk factors for the development of PKS, TKA alignment was measured via postoperative X-ray images. RESULTS: Improvement of the average knee flexion of 35.7° and total flexion of 107.4° was detected in PKS patients after MUA. The flexion of the control group was 112.4°; no significant between-group difference was present regarding prosthesis type, sex, age and BMI. Regarding KSS, WOMAC, and SF-12, the MUA cohort achieved statistically-relevant lower overall scores than the control group, p = 0.006, p = 0.005, p = 0.001, respectively. Significantly higher experiences of pain and a higher need for analgesics in MUA patients were reported (p = 0.001 and p < 0.001, respectively). Radiological evaluation of the prosthesis alignment did not show any differences between the two groups. CONCLUSIONS: MUA can improve mobility after PKS, whereby MUA seemed to be a functional therapy option for PKS. Compared to the control group, the MUA group showed lower functional values and an increased experience of pain. A correlation between prosthesis malalignment and MUA could not be detected radiologically. Further studies are necessary to investigate the reasons for PKS.

Knee joint stiffness following immobilization and remobilization: A study in the rat model.

Deficits in extension can limit the function and performance of the knee joint. The range of motion (ROM) deficit in knee extension is often measured and reported at a single torque value applied in the flexion-extension axis. This static measurement of ROM omits key details about the biomechanical properties of the knee, such as its mechanical stiffness. Our objectives were (1) to quantify knee extension stiffness after various periods of immobilization and remobilization, and (2) to evaluate how stiffness correlated with the length of the posterior knee capsule. Two hundred fifty-six male Sprague Dawley rats had one knee immobilized at a 45° angle in flexion using a Delrin® plate for 6 different durations ranging from 1 to 32 weeks. Remobilization was initiated by removing the plate and lasted for 0-48 weeks. The contralateral knee and unoperated age-matched rats were used as controls. An automated arthrometer extended the knee at four pre-determined torques and these data were used to calculate mechanical stiffness. The stiffness of knees immobilized for 8 or more weeks was significantly greater than controls and persisted despite remobilization (p < 0.05). Remobilization after 16 and 32 weeks of immobilization resulted in a progressive increase in mechanical stiffness (p < 0.05). The length of the posterior capsule significantly correlated with knee stiffness in extension (p < 0.05). Deficit in knee extension was characterized by increased stiffness, which was irreversible upon unassisted remobilization.

Manipulation under Anaesthesia for Patient Reported Stiffness after Total Knee Arthroplasty in an Asian Population

@#Introduction:Stiffness after Total Knee Arthroplasty (TKA) is a complication that decreases patient satisfaction. Patients in an Asian population have potentially different requirements of knee range of motion. The authors have encountered patients who complain of subjective stiffness post TKA who do not have a severely restricting range of motion (ROM). Some patients have persistent subjective stiffness and undergone Manipulation Under Anaesthesia (MUA). We look at their functional outcomes post MUA. Materials and Methods: This is a retrospective study, including 48 patients from a single institution who underwent MUA for stiffness, separated into objective and subjective knee stiffness. Patients with subjective knee stiffness who underwent MUA had failed conservative management. ROM, Oxford Knee Scores (OKS), Knee Society Scores (KSS) and Short Form 36 (SF36) scores were compared at two years post MUA. Results: The demographics of the two patient groups were similar. The time interval between index TKA and MUA was higher in the subjective knee stiffness group. Pre-MUA OKS, KS Function Score, KSS and SF36 scores were similar in both patient subgroups. There was no significant difference in the OKS, KSS or SF36 at two year follow-up. The proportion of patients in each group who achieved the Minimum Clinically Important Difference (MCID) improvement in the scores was also similar. Conclusions: Patients with subjective knee stiffness can achieve similar functional outcome improvements in Oxford and Knee Society Scores with MUA at two years follow-up.

Inverted Cyclops Lesion of the Knee Associated with a Supracondylar Femoral Nail: A Case Report.

While cyclops lesion, a fibrous nodule on the tibial side of the knee joint, is a well-known condition complicating anterior cruciate ligament, inverted cyclops lesion, a fibrous nodule on the femoral side of the knee, is a relatively less known condition. We report a case of inverted cyclops in a patient who presented with chronic knee stiffness eight years after supracondylar nailing of a femoral shaft fracture. There are only four reported cases of inverted cyclops in literature. Literature has been reviewed and the importance of not missing such a lesion is discussed.

Younger age is associated with increased odds of manipulation under anesthesia for joint stiffness after total knee arthroplasty.

INTRODUCTION: Limited range of motion (ROM) after total knee replacement (TKR) is associated with low function and might require manipulation under anaesthesia (MUA). In order to identify factors associated with a limited ROM we investigated predictors for MUA. We hypothesized that older age was associated with higher MUA due to limited ROM post TKR. METHODS: In a case control study we investigated all patients undergoing primary TKR at a University Hospital in Sweden between 2007-2012. We registered background factors and compared those between the group who underwent MUA and those who did not. Odds ratios (OR) were calculated in a univariate analysis and an adjusted regression analysis. RESULTS: Of the total of 669 TKRs performed, 31 patients who had undergone MUA were identified. The prevalence of MUA was 4.6%. The mean increase in ROM after MUA was 27 degrees at final minimum one-year follow-up. After controlling for confounders, patients with good health and young age had increased OR for MUA. OR decreased 0.93 (CI 0.93-0.97) per increased age year in the multiple regression analysis. Diabetes mellitus, BMI and sex did not have a significant effect on the odds ratio for MUA. DISCUSSION: Young patients undergoing TKR has earlier been identified as a group with a higher grade of dissatisfaction and complications. We found an association between young age and MUA after TKR indicating an additional, rather unknown complication for this group of patients. The background and reasons for this has to be further investigated. LEVEL OF EVIDENCE: II, cohort study/case control study (case control is level III).

Prevalence and healthcare usage of knee pain in South Australia: a population-based study.

BACKGROUND: It is known that South Australia (SA) has the highest rate of knee arthroscopy use of any state in Australia; however, Level 1 evidence demonstrates that knee arthroscopy in patients with uncomplicated knee osteoarthritis confers no benefit. In SA, which patients are presenting with knee pain and what treatments are they receiving? AIMS: To determine the prevalence, persistence and treatment modalities of knee pain in SA. METHODS: This study analysed data from the North-West Adelaide Health Study (1999-2015), a longitudinal, population-based cohort study of people aged 18 years and over (n = 4060), initially randomly selected from the north-west region of Adelaide, SA. It incorporated clinic assessments, self-completed questionnaires and telephone interviews to collect demographic, anthropometric and biochemical data over four main stages (1, 2, 3 and North-West 15 (NW15)). Data were linked to Medical Benefits Scheme data. RESULTS: In stages 3 and NW15 of the North-West Adelaide Health Study, 30-35% of participants reported knee pain (n = 803, 452). Demographic variables associated with knee pain included older age and lower educational level, while risk factors included obesity and high waist circumference. In the 12 months preceding NW15, 33% of participants with knee pain/stiffness consulted a general practitioner for their knee pain, 10.2% an orthopaedic surgeon, and 12.6% a physiotherapist. Between 2011 and 2015, 3.0% the cohort underwent a knee arthroscopy, and 3.1% underwent knee magnetic resonance imaging. CONCLUSIONS: Knee pain affects large proportions of the SA population. Knee pain was persistent with underuse of non-pharmacological treatments and high use of specialist referral. These data support the need for a national strategy to manage osteoarthritis effectively.