When dealing with a flexion contracture, a surgeon first should consider all potential causes, specifically ligament contracture and osteophytes. Then consider the size of the femoral component and its position proximal to distal and also the posterior slope of the tibial component. Most knee flexion contractures are caused by osteophytes and tight ligaments, and once these problems are corrected, no further work needs to be done on the knee. So when the bone surface cuts are made, in general, little compensation is done in terms of positioning the femoral component proximal or distal, or in terms of sloping the tibial component (beyond the normal 3–4 degrees posterior slope), before the ligaments or osteophytes are managed. If the deep medial collateral ligament (MCL) and posterior portion of the superficial MCL are tight, a flexion contracture will almost always be present after the bone surfaces are finished. Once this is corrected with proper ligament releases and removal of osteophytes, then ligament balance and flexion contracture should be reassessed. In the very few cases that still have a flexion contracture, posterior capsule release should be done. Once this is finished, releasing the capsule from both the femur and the medial aspect of the tibia, then ligament balance is reassessed again. If flexion contracture still remains (<10% of cases), then the distal surface of the femur is resected another 4–6 mm, trial components are inserted, and flexion contracture is evaluated. If more bony resection is needed, then changing tibial slope from 4 degrees posterior slope to 0 degrees slope is another step that can be done to remove bone from extension space of the knee finally to achieve full extension. Virtually all flexion contractures, except those with severe contracture resulting from hamstring tightness, can be corrected with this method. In the valgus knee with flexion contracture, similar management is used. Knees that will not extend and remain tight on the lateral side usually are corrected with release of the posterior capsule and posterior portion of the iliotibial band. Just as on the lateral side, bone resection from the distal femur can be performed as a final effort to achieve full extension of the knee. It is worth reiterating that almost all flexion contractures are caused by ligament imbalance, and that over-resection of the distal femur at the start of these cases can easily result in hyperextension that is difficult to manage once ligaments have been balanced

Introduction. The range of motion (ROM) obtained after total knee arthroplasty (TKA) is an important measurement to evaluate the postoperative outcomes impacting other measures such as postoperative function and satisfaction. Flexion contracture is a recognized complication of TKA, which reduces ROM or stability and is a source of morbidity for patients. Objectives. The purpose of this study was to evaluate the influence of intra-operative soft tissue release on correction of flexion contracture in navigated TKA. Methods. This is prospective cohort study, 43 cases of primary navigation assisted TKA were included. The mean age was 68.3 ± 6.8 years. All patients were diagnosed with grade 4 degenerative arthritis in K-L grading system. The average preoperative mechanical axis deviation was 10.3° ± 5.3 and preoperative flexion contracture was 12.8° ± 4.8. All arthroplasties were performed using a medial parapatellar approach with patellar subluxation. First, medial release was performed, and posterior cruciate ligament was sacrificed. After all bone cutting was performed and femoral and tibial trials were inserted, removal of posterior femoral spur and capsular release were performed. The degree of correction of flexion contracture was evaluated and recorded with navigation. Results. After the medial soft tissue release, as a first step, the flexion contracture was recorded as 7.2° ± 4.3 and 4.1° ± 4.0 as varus. The second step, posterior cruciate ligament was sacrificed, the flexion contracture was recorded as 7.2° ± 4.4 and 5.5° ± 3.0 as varus. After posterior clearing procedure and capsular release, the flexion contracture was showed as 3.9° ± 1.2 and 1.4° ± 1.2 as varus. The final angles after cemented real implant were recorded as 3.3° ± 1.4 in flexion contracture, 0.9° ± 1.8 in varus. There were significant differences all steps except between medial release step and posterior cruciate sacrifice step and between posterior clearing step and final angle. Conclusions. The appropriate soft tissue balancing could correct flexion contracture intra-operatively. The medial release could correct the flexion contracture around 5° compared with preoperative flexion contracture, and posterior clearing procedure could improve further extension. However, the sacrifice of posterior cruciate ligament provided little effect on correction of the flexion contracture intra-operatively

Introduction. Stiffness postTotal Knee Replacement (TKR) is a common, complex and multifactorial problem. Many reports claim that component mal-rotation plays an important role in this problem. Internal mal-rotation of the tibial component is underestimated among surgeons when compared to femoral internal mal-rotation. We believe the internal mal- rotation of thetibial component can negatively affect the full extension of Knee. We performed an in-vivo study of the impact of tibial internal mal-rotation on knee extension in 31 cases. Method. During TKR, once all bony cuts were completed and flexion/extension gaps balanced, we assessed the degree of knee extension using the trial component in the setting of normaltibial rotation and with varying degrees of internal rotation (13–33°, mean 21.2±4.6°). Intra-operative lateral knee X-ray was done to measure the degree of flexion contracture in both groups. We also compared the degree of flexion contracture between CR and PS spacers. Results. The average degree of knee flexion contracture with normal rotation of the tibial component was 0.7±4.1° (range:-9 to 10), whereas after tibial internal rotation was 7.3±4.6° (range:-1 to 23)(P – value:0.001). The increase in the flexion contracture deformity was higher with PS spacer (7.18±2.61) than with CR spacers (5.22±2.05). Conclusion. The internal mal-rotation of the tibial component limits the ability of the tibia to externally rotate on the femur, thereby limiting full knee extension and leading to flexion contracture

The etiology of the flexion contracture is related to recurrent effusions present in a knee with end-stage degenerative joint disease secondary to the associated inflammatory process. These recurrent effusions cause increased pressure in the knee causing pain and discomfort. Patients will always seek a position of comfort, which is slight flexion. Flexion decreases the painful stimulus by reducing pressure in the knee and relaxing the posterior capsule. Unfortunately, this self-perpetuating process leads to a greater degree of contracture as the disease progresses. Furthermore, patients rarely maintain the knee in full extension. Even during the gait cycle the knee is slightly flexed. As their disease progresses, patients limit their ambulation and are more frequently in a seated position. Patients often report sleeping with a pillow under their knee or in the fetal position. All of these activities increase flexion contracture deformity. Patients with excessive deformity >40 degrees should be counseled regarding procedural complexity and that increasing constraint may be required. Patients are seen preoperatively by a physical therapist and given a pre-arthroplasty conditioning program. Patients with excessive flexion contracture are specifically instructed on stretching techniques, as well as quadriceps rehabilitation exercises. The focus in the postoperative physiotherapy rehabilitation program continues toward the goal of full extension. Patients are instructed in appropriate stretching regimes. Patients are immobilised for the first 24 hours in full extension with plaster splints, such as with a modified Robert Jones dressing. This dressing is removed on postoperative day one. The patient is then placed in a knee immobiliser and instructed to wear it at bed rest, during ambulation and in the evening, only removing for ROM exercises. In cases of severe flexion deformity >30 degrees, patients are maintained in full extension for 3–4 weeks until ROM is begun. Patients are encouraged to use a knee immobiliser for at least the first 6 weeks postoperatively. Treating patients with flexion contracture involves a combination of bone resection and soft tissue balance. One must make every effort to preserve both the femoral and tibial joint line. In flexion contracture the common error is to begin by resecting additional distal femur, which may result in joint line elevation and mid-flexion instability. The distal femoral resection should remove that amount of bone being replaced with metal. Attention should be directed at careful and meticulous balance of the soft tissues and release of the contracted posterior capsule with re-establishment of the posterior recess, which will correct the majority of flexion contractures. Inability to achieve ROM after TKA represents a frustrating complication for both patient and surgeon. Non-operative treatments for the stiff TKA include shoe lift in contralateral limb, stationery bicycle with elevated seat position, extension bracing, topical application of hand-held instruments to areas of soft tissue-dysfunction by a trained physical therapist over several outpatient sessions, and use of a low load stretch device. Manipulation under anesthesia is indicated in patients after TKA having less than 90 degrees ROM after 6 weeks, with no progression or regression in ROM. Other operative treatments range from a downsizing exchange of the polyethylene bearing to revision with a constrained device and low-dose irradiation in cases of severe arthrofibrosis

Introduction. The effect of the implant posterior condylar offset has recently generated much enthusiasm among researchers. Some reports were concerned about the relationship between the posterior condylar offset and an extension gap. However, the posterior condylar offset was measured in a flexed knee position or in reference to femoral anatomy alone. Posterior femoral condylar offset relative to the posterior wall of the tibia (posterior offset ratio; POR) is possibly the risk of knee flexion contracture associated with posterior femoral condylar offset after TKA. However, there are no reports concerning the relationship between POR and flexion contracture in vivo. The aim of this study is to evaluate the relationship between the measurement of POR and flexion contracture of the knee in vivo. Methods. Twenty-seven patients who underwent a primary total knee arthroplasty (PFC Sigma RP-F) were participated in the study. The lateral femoro-tibial angle (lateral FTA) was measured using lateral radiographs obtained by two procedures. Two procedures are applied to obtain true lateral radiographs of the lower extremities. (1) Full-length true lateral radiographs on standing, (2) True lateral radiographs in the prone position (Fig. 1A). ‘Posterior offset ratio’ was defined as Fig. 1B. Significant differences among groups were assessed using two-tailed Student's t-tests. Spearman's correlation analysis was performed to evaluate the relationship between lateral FTA and posterior offset ratio of patients. Results. The mean value of the POR on standing was 14.94 ± 7.53%. The mean value of flexion contracture of the knee on standing was 11.67 ± 9.21 degree and that in the prone position was 4.22 ± 6.17 degree (P = 0.001). The POR was negatively correlated with flexion contracture of the knee in all procedures with statistical significance (standing: r = 0.62, P = 0.0039; prone: r = 0.66, P = 0.0001) (Fig. 2). Discussion. We have evaluated flexion contracture by two procedures. The mean value of flexion contracture of the knee on standing was 11.67 ± 9.21 degree, whereas that in the prone position was 4.22 ± 6.17 degree. We surmised that this discrepancy occurred due to the flexor muscle tension on standing. In terms of the evaluation of posterior soft tissue tightness of the knee, muscle relaxation can be achieved in prone position is rather than standing position. Our study investigated the relationship between the posterior protrusions of the posterior condyle of the femur relative to the tibia (POR) and flexion contracture after TKA evaluated by two measurement procedures. POR is strongly correlated with flexion contracture evaluated by both measurement procedures. The value of POR of this implant in vitro was about 25% in previous study, whereas the mean value of POR in vivo was 14.94%, suggesting that POR in the flexion contracture knee relatively reduced because posterior soft tissue pushed femoral component anteriorly. Our result clearly showed that if posterior clearance is insufficient, flexion contracture occur due to posterior soft tissue tightness. In conclusion, POR after TKA in vivo negatively correlate with flexion contracture presumably because posterior soft tissue pushed femoral component anteriorly

Flexion contracture sometimes occurs after primary total knee arthroplasty (TKA). In most cases, flexion contracture after TKA gradually improves over time. However, some severe cases require manipulation or revision surgery. We searched our clinical database for patients who underwent primary TKA at our institution between 2008 and 2015. By reviewing patient records, we identified three patients (one man and two women) with a severe flexion contracture 30° after primary TKA. Although all three patients gained more than 120° in flexion intraoperatively, they developed flexion contracture after discharge from our institution. We performed manipulation under anaesthesia (MUA) for all three cases several months later. The two female patients had improved range of motion (ROM) right after the manipulation. However, one of them regained flexion contracture 1 year after the MUA. We report the details of the male patient, who had the worst flexion contracture (−60°). An 80-year-old man had right knee osteoarthritis. His history indicated only hypertension. The right knee ROM before the TKA was −20° extension and 135° flexion. His radiographs showed advanced-stage osteoarthritis. We performed cemented TKA (posterior stabiliser design). Three weeks after the operation, his right knee pain improved. The right knee ROM was −10° extension and 100° flexion just before discharge. However, he returned to our institution because of right knee pain and flexion contracture 31 months after the surgery. The flexion contracture gradually worsened without any trauma. When he returned, the right knee ROM was −60° extension and 135° flexion. Manipulation under general anaesthesia was not effective. Therefore, we performed revision TKA immediately. We excised the scar tissue of the posterior knee joint. Then, we shortened the distal femoral end by 1 cm and reduced the size of the femoral component. After the operation, the right knee ROM was improved to −10° flexion and 130° extension. The reported prevalence of stiffness after TKA was from 1.3% to 13%. Although the deleterious effects of persistent flexion contractures > 15° is well understood, whether they resolve with time or need surgical intervention is controversial. MUA is generally the initial option for patients with flexion contractures, with the possibility of some improvement. If severe flexion contracture remains after manipulation, revision TKA, which may be considered as a useful treatment option, should be considered

The etiology of the flexion contracture is related to recurrent effusions present in a knee with end-stage degenerative joint disease secondary to the associated inflammatory process. These recurrent effusions cause increased pressure in the knee causing pain and discomfort. Patients will always seek a position of comfort, which is slight flexion. Flexion decreases the painful stimulus by reducing pressure in the knee and relaxing the posterior capsule. Unfortunately, this self-perpetuating process leads to a greater degree of contracture as the disease progresses. Furthermore, patients rarely maintain the knee in full extension. Even during the gait cycle the knee is slightly flexed. As their disease progresses, patients limit their ambulation and are more frequently in a seated position. Patients often report sleeping with a pillow under their knee or in the fetal position. All of these activities increase flexion contracture deformity. Patients with excessive deformity >40 degrees should be counseled regarding procedural complexity and that increasing constraint may be required. Patients are seen pre-operatively by a physical therapist and given a pre-arthroplasty conditioning program. Patients with excessive flexion contracture are specifically instructed on stretching techniques, as well as quadriceps rehabilitation exercises. Avoiding Pitfalls and Complications: Treating patients with flexion contracture involves a combination of bone resection and soft tissue balance. One must make every effort to preserve both the femoral and tibial joint line. In flexion contracture the common error is to begin by resecting additional distal femur, which may result in joint line elevation and mid-flexion instability. The distal femoral resection should remove that amount of bone being replaced with metal. Attention should be directed at careful and meticulous balance of the soft tissues and release of the contracted posterior capsule with re-establishment of the posterior recess, which will correct the majority of flexion contractures. Residual Flexion Contracture: Inability to achieve ROM after TKA represents a frustrating complication for both patient and surgeon. Non-operative treatments for the stiff TKA include shoe lift in contralateral limb, stationery bicycle with elevated seat position, extension bracing, topical application of hand-held instruments to areas of soft tissue-dysfunction by a trained physical therapist over several outpatient sessions, and use of a low load stretch device. Manipulation under anesthesia is indicated in patients after TKA having less than 90 degrees ROM after 6 weeks, with no progression or regression in ROM. Other operative treatments range from a downsizing exchange of the polyethylene bearing to revision with a constrained device and low-dose irradiation in cases of severe arthrofibrosis

Introduction. Stiffness post Total Knee Replacement (TKR) is a common, complex and multifactorial problem. Many reports claim that component mal-rotation plays an important role in this problem. Internal mal-rotation of the tibial component is underestimated among surgeons when compared to femoral internal mal-rotation. We believe the internal mal-rotation of the tibial component can negatively affect the full extension of Knee. We performed an in-vivo study of the impact of tibial internal mal-rotation on knee extension in 31 cases. Method. During TKR, once all bony cuts were completed and flexion/extension gaps balanced, we assessed the degree of knee extension using the trial component in the setting of normal tibial rotation and with varying degrees of internal rotation (13–33°, mean 21.2±4.6°). Intra-operative lateral knee X-ray was done to measure the degree of flexion contracture in both groups. We also compared the degree of flexion contracture between CR and PS spacers. Results. The average degree of knee flexion contracture with normal rotation of the tibial component was 0.7±4.1° (range: −9 to 10), whereas after tibial internal rotation was 7.3±4.6° (range: −1 to 23) (P – value:0.001). The increase in the flexion contracture deformity was higher with PS spacer (7.18±2.61) than with CR spacers (5.22±2.05). Conclusion. The internal mal-rotation of the tibial component limits the ability of the tibia to externally rotate on the femur, thereby limiting full knee extension and leading to flexion contracture

Introduction. Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture to restore range of motion and knee function. However, the effect of joint line elevation on the resulting TKA kinematics including frontal plane laxity is unclear. Thus, our goal was to quantify the effect of additional distal femoral resection on passive extension and mid-flexion laxity. Methods. Six computational knee models with capsular and collateral ligament properties specific to TKA were developed and implanted with a contemporary posterior-stabilized TKA. A 10° flexion contracture was modeled by imposing capsular contracture as determined by simulating a common clinical exam of knee extension and accounting for the length and weight of each limb segment from which the models were derived (Figure 1). Distal femoral resections of 2 mm and 4 mm were simulated for each model. The knees were then extended by applying the measured knee moments to quantify the amount of knee extension. The output data were compared with a previous cadaveric study using a two-sample two-tailed t-test (p<0.05) [1]. Subsequently, varus and valgus torques of ±10 Nm were applied as the knee was flexed from 0° to 90° at the baseline, and after distal resections of 2 mm, and 4 mm. Coronal laxity, defined as the sum of varus and valgus angulation in response to the applied varus and valgus torques, was measured at 30° and 45°of flexion, and the flexion angle was identified where the increase in laxity was the greatest with respect to baseline. Results. With 2 mm and 4 mm of distal femoral resection, the knee extended an additional 4°±0.5° and 8°±0.75°, respectively (Figure 2). No significant difference was found between the extension angle predicted by the six models and the results of the cadaveric study after 2 mm (p= 0.71) and 4 mm (p= 0.47). At 2 mm resection, mean coronal laxity increased by 3.1° and 2.7° at 30° and 45°of flexion, respectively. At 4 mm resection, mean coronal laxity increased by 6.5° and 5.5° at 30° and 45° of flexion, respectively (Figures 3a and 3b). The flexion angle corresponding to the greatest increase in coronal laxity for 2 mm of distal resection occurred at 22±7° of flexion with a mean increase in laxity of 4.0° from baseline. For 4 mm distal resection, the greatest increase in coronal laxity occurred at 16±6° of flexion with a mean increase in laxity of 7.8° from baseline. Conclusion. A TKA computational model representing a knee with preoperative flexion contracture was developed and corroborated measures from a previous cadaveric study [1]. While additional distal femoral resection in primary TKA increases passive knee extension, the consequent joint line elevation induced up to 8° of additional coronal laxity in mid-flexion. This additional midflexion laxity could contribute to midflexion instability; a condition that may require TKA revision surgery. Further studies are warranted to understand the relationship between joint line elevation, midflexion laxity, and instability. For any figures or tables, please contact the authors directly

Objective. In a cruciate retaining total knee arthroplasty (CR-TKA) for patients with flexion contracture, to ensure that an extension gap is of sufficient size to install an implant, the amount of distal femur bone resection needed is frequently larger in a patient with knee flexion contracture than in one without contracture. In this study, we compared the distal femur bone resection amount, the component-secured extension gap margin value, and the range of motion at 6 months after surgery between patients with knee flexion contracture and those without knee flexion contracture. Method. We examined 51 joints including 27 joints in patients with preoperative extension limitation of less than 5 degrees (the F0 group) and 24 joints in patients with limitation of 15 degrees or larger (up to 33 degrees; the FC group) who underwent CR-TKA with LCS RP (DePuy Synthes) between May 2013 and April 2014. In case with an extension gap 3 mm or smaller than the flexion gap after initial bone resection, we released posterior capsule adequately, trying to minimize the distal femur additional bone resection amount as possible. With installation of a femoral trial, the component gaps were measured using spacer blocks. The measured parameters included the intraoperative bone resection length, gap difference (FG − EG, i.e., difference between the flexion gap [FG] and extension gap [EG]), and range of motion 6 months after surgery. Results. No inter-group difference was found in the length of the distal femur bone initially resected in the medial side of distal femur(F0: 6.7 ± 1.3 mm, FC: 6.1 ± 1.4 mm) and total length of bone resection (= first + additional resection) in the lateral proximal tibia (F0: 10.3 ± 1.9 mm, FC: 10.4 ± 2.1 mm). The length of the additional distal femur bone resected was 0.9 ± 1.3 mm in the F0 and 1.5 ± 1.2 mm in the FC (P = 0.06; Mann-Whitney U). The FG-EG (F0: 0.7 ± 0.9 mm, FC: 0.6 ± 0.8 mm) showed no remarkable inter-group difference. The mean range of motion was changed from −2.3° to −0.6° at extension and from 130.4° to 128.7° at flexion in the F0 and from −19.8° to −2.7° at extension and from 113.7° to 122.3° at flexion in the FC. Conclusions. The amount of distal femur bone resected should not be simply increased because this may elevate the joint line, narrow the flexion range, and cause the joint instability in mid-flexion. The results of this study show that, in CR-TKA for patients with flexion contracture up to 30°, the length of distal femoral bone resection of approximately 1 mm larger than that in patients without contracture may ensure an extension gap of necessary and sufficient length to install an implant

Identifying and restoring alignment is a primary aim of total knee arthroplasty (TKA). In the coronal plane, the pre-pathological hip knee angle can be predicted using an arithmetic method (aHKA) by measuring the medial proximal tibial angle (MPTA) and lateral distal femoral angle (aHKA=MPTA - LDFA). The aHKA is shown to be predictive of coronal alignment prior to the onset of osteoarthritis; a useful guide when considering a non-mechanically aligned TKA. The aim of this study is to investigate the intra- and inter-observer accuracy of aHKA measurements on long leg standing radiographs (LLR) and preoperative Mako CT planning scans (CTs). Sixty-eight patients who underwent TKA from 2020–2021 with pre-operative LLR and CTs were included. Three observers (Surgeon, Fellow, Registrar) measured the LDFA and MPTA on LLR and CT independently on three separate occasions, to determine aHKA. Statistical analysis was undertaken with Bland-Altman test and coefficient of repeatability. An average intra-observer measurement error of 3.5° on LLR and 1.73° on CTs for MPTA was detected. Inter-observer errors were 2.74° on LLR and 1.28° on CTs. For LDFA, average intra-observer measurement error was 2.93° on LLR and 2.3° on CTs, with inter-observer errors of 2.31° on LLR and 1.92° on CTs. Average aHKA intra-observer error was 4.8° on LLR and 2.82° on CTs. Inter-observer error of 3.56° for LLR and 2.0° on CTs was measured. The aHKA is reproducible on both LLR and CT. CT measurements are more reproducible both between and within observers. The difference between measurements using LLR and CT is small and hence these two can be considered interchangeable. CT may obviate the need for LLRs and may overcome difficulties associated with positioning, rotation, body habitus and flexion contractures when assessing coronal alignment

Introduction. In TKA, it is important to make the equal extension and flexion gap (EG and FG) of the knee. Although, this principal concept applies to all knees, flexion contracture is known to have difficulties to achieve the equal EG and FG because of its smaller EG than usual. Whereas, it is also well known that PCL resection makes FG wider than EG, however, many surgeons recommend PCL resection in case of flection contracture because it is easy to manage during surgery, nevertheless the risk of further gap unbalance. Although, flexion contracture is not rare in TKA, the controversial problem of the PCL resection for the flexion contracture still remains even in today. Materials and methods. To investigate this contradiction, we measured intra-operative EG and FG of the knee with 20 degree or more pre-operative flexion contracture. The gaps were measured by 3 different ways; a tension device system with 30 and 40 pound tension (group 1 and 2) and a spacer block system which had 1 mm increment thickness variation (group 3). The cases were 41, 46 and 51 knees in group 1, 2 and 3 respectively. Group 1 and 2 have overlapping in 27 knees. Results. In our hospital, femoral posterior condylar 4 mm pre-cut is routinely used, so the data of the FG was corrected by the amount of pre-cut. After usual distal femoral cut and tibial cut and the femoral posterior condylar pre-cut, EG and FG before PCL resection were 16.2±2.7 and 20.3±3.3 mm / 17.7±4.0 and 22.2±3.8 mm / 15.3±4.0 and 18.7±2.8 mm in group 1, 2 and 3 respectively. Group 3 showed smaller gaps than group 1 and 2 and group 1 showed smaller than group 2. EG was significantly smaller than FG in all groups (p<0.001). The difference between both gaps was 4.1±3.2, 4.4±3.9 and 3.4±3.7 mm in group 1, 2 and 3 respectively. Nevertheless the different measurement methods, the results were similar among 3 groups. To avoid additional widening of the gap difference due to PCL resection, CR components were implanted with 84 knees and PS with 27 knees. Discussion. Although, the gap measurement methods are often discussed about their reliabilities, how much distraction force is necessary with the tension device systems and how accurate measurement is possible with the spacer block systems are obscure. Our results showed some different results among 3 groups, however, the EG was apparently smaller than the FG and the difference between EG and FG was similar among 3 groups. PS component is usually selected in TKA in patients with flexion contracture, especially with severe contracture because it is easy to manage during surgery without PCL. The purpose of TKA is to make adequate EG and FG, however, our results indicated the risk of severe unbalance between EG and FG when the PCL was resected in every knee with flexion contracture. Regardless of the measurement methods, intra-operative estimation of the difference between EG and FG is important, especially in the knees with flexion contracture

Background. Arthrogryposis Multiplex Congenita is a rare congenital disorder associated with multiple musculoskeletal contractures which causes substantial morbidity. Knee involvement is commonly seen among children with arthrogryposis, with flexion contracture being the most frequent. The purpose of this study was to assess the effectiveness of orthopaedic procedures, namely distal femoral supracondylar extension osteotomy and/or Ilizarov external fixator, on the ambulation status of children with knee flexion contracture and whether any functional gains are maintained at the latest follow-up. Methods. Fifteen patients were identified and their medical records reviewed. The mean age at their first surgery was 7.6 years (range, 2-16 years). The etiology for all patients was amyoplasia. The mean length of follow-up was 58 months (range, 12-117 months). Contractures were treated with femoral extension osteotomy (n=8), Ilizarov external fixator (n=2), or both (n=5). Results. Pre-operatively, 11 patients were non-ambulatory, three patients were household ambulators, and one patient walked with orthoses in the community. There was an average of 1.5 knee surgeries done per patient. At the latest follow-up, nine patients were ambulatory with technical aids, two patients were household ambulators, one patient used a wheelchair but was independent for transfers, and three patients remained non-ambulatory. The mean flexion contracture prior to the first surgery was 62.8 ± 26.7 degrees. Post-operatively, the mean flexion contracture was 13.5 ± 16.4 degrees. At the latest follow-up, the mean flexion contracture was 33.8 ± 23.6 degrees. There were complications in three patients which included infected hardware, transient neurological compromise, and pressure sores, which eventually all resolved. Conclusion. early and aggressive orthopaedic management of flexion contractures in children with arthrogryposis is supported by our findings, and may contribute to functional gains

Introduction. A stiff total knee arthroplasty (TKA) is an uncommon but disabling problem because it causes pain and limited function. Revision surgery has been reported as a satisfactory treatment option for stiffness with modest benefits. The aim of this study was to evaluate the results of revision surgery for the treatment of stiffness after TKA. Methods. We defined stiffness as 15 degrees or more of flexion contracture or less than 75º of flexion or a range of motion of 90º or less presenting with a chief complain of limited range of motion and pain. We evaluated the results of forty-two revisions performed by one of four orthopedic surgeons due to stiffness after TKA. Patients with history of infection or isolated polyethylene insert exchange were excluded. Results. Patients were followed for an average of forty-seven months. The mean Knee Society score improved from 43.9 points preoperatively to 72.0 points at the time of follow-up and the mean Knee Society function score from 48.7 to 70.1 respectively. Pain improved in 73% of the patients and four patients (9.5%) presented severe pain at latest follow up. The mean flexion contracture decreased from 9.7º to 2.3º, the mean flexion improved from 81.5º to 94.3º, and the mean range of motion improved from 72º to 92º. The range of motion improved in 80% of the knees and flexion increased in 64.3%. Extension improved in 88% and it remained unchanged in 5%. Conclusion. Revision surgery appears to be a reasonable option for patients presenting with pain and stiffness after TKA. However, the benefits may be modest as the outcomes do not approach those achieved with a primary TKA. Although the flexion contractures were significantly improved and 80% of the knees presented an increase range of motion, the final range of motion was only 92º

Aims/Hypothesis. The aims of this study were: 1) to quantitatively analyse the amount of knee extension that is achieved with +2mm incremental increases in the amount of distal femoral bone that is resected during TKA in the setting of a flexion contracture, 2) to quantify the amount of coronal plane laxity that occurs with each 2mm increase in the amount of distal femur resected. In the setting of a soft tissue flexion contracture, we hypothesized that although resecting more distal femur will reliably improve maximal knee extension, it will ultimately lead to increased varus and/or valgus laxity throughout mid-flexion. Methods. Seven fresh-frozen cadaver legs from hip-to-toe underwent TKA with a posterior stabilized implant using a measured resection technique with computer navigation system equipped with a robotic cutting-guide, in this IRB approved, controlled laboratory study. After the initial tibial and femoral resections were performed, the posterior joint capsule was sutured (imbricated) through the joint space under direct visualization until a 10° flexion contracture was obtained with the trial components in place, as confirmed by computer navigation. Two distal femoral recuts of +2mm each where then subsequently made and after the remaining femoral cuts were made, the trail implants were reinserted. The navigation system was used to measure overall coronal plane laxity by measuring the mechanical alignment angle at maximum extension, 30°, 60° and 90° of flexion, when applying a standardized varus/valgus load of 9.8 [Nm] across the knee using a 4kg spring-load located at 25cm distal to the knee joint line.(Figure 1) Coronal plane laxity was defined as the absolute difference (in °) between the mean mechanical alignment angle obtained from applying a standardized varus and valgus stress at 0°, 30, 60° and 90°. Each measurement was performed three separate times and averaged. The maximal extension angle achieved following each 2mm distal recut was also recorded. Two-tailed student's t-tests were performed to analyze whether there was difference in the mean laxity at each angle and if there was a significant improvement in maximal extension with each recut. P-values < 0.05 were considered significant. Results. For a 10° flexion contracture, performing the first distal recut of +2mm increased overall coronal-plane instability by approximately 3° at 30° and 60° of flexion (p < 0.05).(Figure 2) Performing the second recut of +4mm further increased mid-flexion instability by another 2° (p < 0.01).(Figure 2) Maximum extension increased from 10° of flexion to 6.4° (±2.5° SD, p < 0.005) and to 1.4° (±1.8° SD, p < 0.001) of flexion with each 2mm recut of the distal femur. Conclusions. Using a reliable, accurate, and reproducible method of measuring coronal plane laxity and maximal knee extension, we have shown that in the setting of a flexion contracture or tight extension space during TKA, recutting the distal femur by 2 mm will effectively increase the amount of maximal extension by 4°; however, as a secondary effect, recutting the distal femur by 2 mm will also lead to 2.5° of increased coronal plane laxity in midflexion

Juvenile idiopathic arthritis(JIA) is chronic inflammation commonly occurs in early childhood. Recently, biological therapies are used in JIA at the early stage as same as rheumatoid arthritis, due to retain joint cartilage. However, some of young patients have painful knee problems requiring knee replacement. We experienced 4 cases of JIA treated by knee arthroplasty. The average age at surgery was 33.5 years (range, 26–38 years) with a mean follow-up of 9.5 years (range, 5–18 years). We evaluated the knee range of motion and functional outcomes by the Knee Society Score (KSS), implant selection, postoperative complication, surgery of another joint. Mean range of motion improved from 76.3° (0°–120°) at pre-operation to 110.6° (80°–130°) at post-operation (P<0.05). Mean KSS increased from 47.3 ±20.1 preoperatively to 86.9 ±11.1 (P<0.01) at last follow-up and the mean KSS function from 27.5 ±25.9 to 62.5±20.2 at last follow-up (P<0.05). All of the TKAs were cemented, 5 were cruciate-retaining implant designs, whereas 2 TKAs had constrained posterior stabilized implant designs. Patellar resurfacing was undergone in all knees. Bone graft required in 1 knee within severe knee deformity. Complication were occurred in 5 knees. Medial instability in 2 knees. Skin necrosis, MCL avulsion, recurrence of the synovitis are one in each. All cases had polyarticular type. Previous THA had undergone in 5 hips, synovectomy in 3 knees, foot surgery in 2 feet. At latest follow-up, 1 of 8 TKAs (12.5%) had been revised, and had revision of its polyethylene exchange only. Patients with JIA often have valgus alignment with a flexion contracture and poor bone quality is also frequently compromised. Prescribed immunosuppressive medication or biological agents may cause to infection. In our series there were no infection, but some of these need much more soft tissue release because of severe deformity and flexion contracture. TKA survivorship for JIA is inferior to that typically seen in younger patients with osteoarthritis or rheumatoid arthritis. The knee of conservative therapy were often caused to severe functional limitations. Timimg of TKA may be indicated no matter how young the patient is. Extending timing of TKA may leads to worse outcome and postoperative function. But it may be caution that the surgical exposure can be difficult, because of stiffness, flexion contracture, bony deformity, osteopenia

Flexion contractures are a common finding in an end-stage arthritic knee, occurring in up to 60% of patients undergoing total knee arthroplasty. Fixed flexion deformities may result from posterior capsular scarring, osteophyte formation, and bony impingement. It is essential to correct this deformity at the time of total knee arthroplasty, as a residual flexion contracture will result in joint overload and abnormal gait mechanics. This may translate to a slower walking velocity, shorter stride length, and pain. This presentation will discuss a systematic way of dealing with flexion contractures to ensure that the total knee arthroplasty will achieve full extension. The surgical technique for treating fixed flexion deformity about the knee includes release of the posterior cruciate ligament, posterior capsular release, adequate distal femoral bone resection, and removal of osteophytes. Postoperatively, attention must be divided between obtaining maximal flexion and full extension. Should a flexion contracture be noted upon the postoperative visit, additional measures should be taken to address it

Flexion contractures are a common finding in an end-stage arthritic knee, occurring in up to 60% of patients undergoing total knee arthroplasty. Fixed flexion deformities may result from posterior capsular scarring, osteophyte formation, and bony impingement. It is essential to correct this deformity at the time of total knee arthroplasty, as a residual flexion contracture will result in joint overload and abnormal gait mechanics. This may translate to a slower walking velocity, shorter stride length, and pain. This presentation will discuss a systematic way of dealing with flexion contractures to ensure that the total knee arthroplasty will achieve full extension. The surgical technique for treating fixed flexion deformity about the knee includes release of the posterior cruciate ligament, posterior capsular release, adequate distal femoral bone resection, and removal of osteophytes. Post-operatively, attention must be divided between obtaining maximal flexion and full extension. Should a flexion contracture be noted upon the post-operative visit, additional measures should be taken to address it

INTRODUCTION. Gross deformity such as severe flexion contraction or severe varus deformity in both knees is better corrected simultaneously to prevent recurrence of flexion contracture and also to have equal leg length which facilitate proper physiotherapy post operatively. However, there is great reluctance in many institute to perform Simultaneous Bilateral Total Knee Replacement (SBTKR) fearing higher complication rate. The purpose of this paper is to show that SBTKR is economical, safe and sometimes is necessary in gross deformity such as bilateral flexion contracture. In this paper we will review the most recent literature about SBTKR which support our argument. Also we will review our cases of over 7500 of SBTKR done at our institution. In this study we will focus on the process that we went through at our institution to upgrade our medical care to enable to do this SBTKR safely. We will share also our post-operative protocol and some hint on the administrative level in order to perform SBTKR. METHODS. In the last 20 years we performed over 7500 SBTKR, 15,000 implants. We have established at our institution a pre-operative team where this team included internist, physiotherapist, anesthesiologist and other medical sub specialty as recommended by the internist. The patient was pre-oped carefully and the extent of medical examination was determined by the internist and the anesthesiologist. Each patient care was determined preoperatively and also we have utilized special complexity scale that we have developed at our institution to reflect the complexity of the primary total knee replacement 1–5. The ASA and complexity scale is now routinely printed on our OR schedule. If the patient was cleared, SBTKR were carried on. The surgery is done first for the right side and after cementing the assistant will start the left side while the senior surgeon will clean the knee and then assist in the second knee. We have tried different modalities and the safest, less confusing was to first finish the first knee and after cementing the other limb was started by the assistant. The surgeon had only two assistants and one scrub nurse. Increasing the no. of assistant will make things more confusing. So we strongly recommend having only one senior surgeon. Post-operative care was almost identical to that of a single total knee replacement. We documented the complication rate, blood transfusion and unexpected ICU admission etc. in the SBTKR and we compared it to over 1000 cases of single knee replacement done at our institution by the same surgeon. The knee score was also was documented on both sides. RESULTS. Blood transfusion as much higher in SBTKR and in spite of using many methods to decrease blood loss we continued to have transfusion rate of 52%. We have established a Task Force that usually meets every two weeks in order to improve the medical conditions. Infection rate was the same in the single and SBTKR. Of interest of the fact that the no. of unexpected ICU admission dropped significantly in the second year- which could be related more to the cooperation and collaboration between the medical team. DISCUSSION AND CONCLUSION. SBTKR is safe as single knee replacement. It is needed in gross deformity and in non-ambulating patient. Getting the institution ready for such a procedure has to be organized through special Task Force and requires extensive collaboration among different part of the hospital dept. We strongly recommend doing SBTKR especially in patients who has a gross deformity and in non-ambulating patient

Fixed flexion contracture is often present in association with osteoarthritis of the knee and correction is one of the key surgical goals in total knee replacement. Surgical strategies to correct flexion contracture include removal of posterior osteophytes, posterior capsular release and additional distal femoral bone resection. Traditional teaching indicates 2 mm of additional distal femoral bone resection will correct 10 degrees of flexion deformity. However some studies have questioned this figure and removing excessive distal femoral bone results in elevation of the joint line, potentially causing patella baja, alteration in collateral ligament tension through the flexion arc and mid-flexion instability. The aim of our study is to determine the relationship between distal bone resection of the femur and passive knee extension in total knee arthroplasty. A cohort of 50 patients, undergoing total knee arthroplasty, was recruited. Following complete femoral and tibial bone preparation, to simulate the effect of distal femoral bone resection, augments of 2 mm increments (2 mm, 4 mm, 6 mm, 8 mm) were placed onto the trial femoral component. The degree of flexion contracture with each augment was measured using computer navigation. The results showed a 2 mm augment produced an average of 3.37 degrees of flexion deformity. A 4 mm augment led to an average of 6.68 degrees fixed flexion, whilst a 6 mm augment produced 11.38 degrees. To correct 10 degrees flexion deformity, an additional 6 mm distal femoral bone resection is required. In conclusion, additional distal femoral bone resection may not be as an effective strategy as previously believed to correct fixed flexion deformity in total knee arthroplasty