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Purpose: In navigated TKA, the risk of notching is high if femoral component sagittal positioning is planned perpendicular to the sagittal mechanical axis of femur (SMX). We intended to determine if, by opting to place the femoral component perpendicular to distal femur anterior cortex axis (DCX), notching can be reduced in navigated TKA. Methods: We studied 171 patients who underwent simultaneous bilateral computer-assisted TKA. Femoral component sagittal positioning was planned perpendicular to SMX in one knee (Femur Anterior Bowing Registration Disabled, i.e. FBRD group) and perpendicular to DCX in the opposite knee (Femur Anterior Bowing Registration Enabled, i.e. FBRE group). Incidence and depth of notching were recorded in both groups. For FBRE knees, distal anterior cortex angle (DCA), which is the angle between SMX and DCX, was calculated by the computer. Results: Incidence and mean depth of notching was less (p=0.0007 and 0.009) in FBRE versus FBRD group, i.e. 7% versus 19.9% and 0.98 mm versus 1.53 mm, respectively. Notching was very high (61.8%) in FBRD limbs when the anterior bowing was severe (DCA>3°) in the contralateral (FBRE) limbs. Conclusion: Notching was less when femoral component sagittal positioning was planned perpendicular to DCX, in navigated TKA. Level of evidence: Therapeutic level II [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this prospective study was to determine correlation between coronal mechanical alignment measured on preoperative standing full-length radiographs and navigation during total knee arthroplasty (TKA) in the presence of an associated sagittal deformity (hyperextension and flexion deformity). Materials and Methods: Coronal mechanical alignment measured on preoperative, standing, full-length, hip-to-ankle anteroposterior radiographs was compared with intraoperative measurements recorded with computer navigation in 200 primary navigated TKAs. Results: The mean difference in mechanical alignment between the two techniques was significantly greater (p=0.001) in patients with an associated flexion deformity >10° when compared to knees with associated flexion deformity ⩽10°; 48% of knees with a flexion deformity >10° had a difference of ⩾3° between the full-length radiograph and navigation alignment measurements. There was a strong correlation between the radiographic and navigation measurement techniques. Conclusions: The mean difference in coronal mechanical alignment between the two techniques was significantly higher in patients with an associated flexion deformity >10°. Hence, surgeons should take caution when relying on preoperative full-length radiographs for determining coronal mechanical alignment in patients with an associated flexion deformity >10° where using navigation may be more reliable. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this retrospective comparative study was to evaluate and compare, radiographically and clinically, progression of osteoarthritis (OA) in the patellofemoral (PF) compartment after open-wedge high tibial osteotomy (OWHTO), and unicompartmental knee arthroplasty (UKA) over a minimum follow-up of 5 years.Methods: In this study, 42 knees in an OWHTO group were compared with 59 knees in a UKA group in terms of radiographic parameters, such as the grading system for OA progression in the PF compartment, and clinical parameters, such as the PF pain and function scores over a minimum follow-up of 5 years.Results: There was no significant difference of OA progression in the PF compartment between the two groups on knee radiography. Compared with the preoperative grades, the UKA group showed significant progression of OA in the medial PF compartment at the final follow-up, whereas the medial PF compartment showed significant stepwise progression by only one grade when compared to the OWHTO group. The PF pain and function scores showed no statistical differences between the two groups at the final follow-up, regardless of OA progression.Conclusions: There was no significant difference between OWHTO and UKA in terms of progression of OA in the PF compartment or deterioration of PF function score over a minimum follow-up of 5 years. However, the medial PF compartment of the UKA group was minimal, and worsened or progressed by only one grade.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Background: This prospective study aimed to verify the efficacy of a novel, hand-held, iPod-based navigation system in comparison to traditional navigation system for total knee arthroplasty (TKA). Methods: Limb alignment, tibial and distal femoral bone cut thickness and plane were recorded intraoperatively using both iPod-based and traditional navigation system in 36 knees undergoing primary TKAs. Results: Intraoperatively, the iPod-based navigation system showed good to excellent correlation and reliability for tibial and distal femoral bone cut thickness, plane of the femoral cut and limb alignment when compared to the traditional navigation system. Conclusions: Despite its quick registration feature, the iPod-based system has an efficacy similar to traditional navigation system and is a positive step towards making navigation systems for TKA more compact, user-friendly, time and cost-effective. [ABSTRACT FROM AUTHOR]

Purpose: Simultaneous bilateral total knee arthroplasty (TKA) is associated with excessive blood loss and morbidity arising from postoperative reduction in hemoglobin (Hb). The purpose of this prospective randomized study was to determine if drains have any effect on blood loss, postoperative reduction in Hb levels and transfusion rates compared to no drainage in simultaneous bilateral TKAs. Materials and Methods: Two hundred and thirty patients who underwent simultaneous bilateral TKA by a single surgeon were randomly allotted to drain or no-drain group (n=115 in each group). Postoperative Hb level, blood loss volume and transfusion rate were compared between the two groups. Results: The mean postoperative Hb level (p=0.38), blood loss volume (p=0.33) and transfusion rate (p=0.52) in the drain group were not significantly different compared to the no-drain group. No statistical difference was found in terms of complications, readmissions and mortality rates between the two groups. Conclusions: No significant difference was observed in the two groups with respect to blood loss and blood transfusion. Non-drainage does not offer an advantage over drainage with respect to conserving blood in simultaneous bilateral TKA. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to determine variation in femoral valgus correction angle (VCA) between the two limbs in a patient with windswept deformity undergoing total knee arthroplasty (TKA). Methods: Femoral VCA was measured on full-length, hip-to-ankle, standing radiographs and was compared between the varus and the valgus limbs in 66 patients with windswept deformities. Results: The mean VCA in varus knees was significantly higher compared to mean VCA in valgus knees (p = 0.002). Conclusion: Significant difference in VCA is present between the varus and the valgus limbs in most patients with windswept deformity undergoing TKA. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective study aimed to determine if computer navigation provides consistent accuracy for limb and component alignment during TKA irrespective of body mass index (BMI) by comparing limb and component alignment and the outlier rates in obese versus non-obese individuals undergoing computer-assisted TKA. Methods: Six hundred and thirty-five computer assisted total knee arthroplasties (TKAs) performed in non-obese individuals (BMI b 30 kg/m²) were compared with 520 computer-assisted TKAs in obese individuals (BMI > 30 kg/m²) for postoperative limb and component alignment using full length standing hip-to-ankle radiographs. Results: No significant difference in postoperative limb alignment (179.7° ± 1.7° vs 179.6° ± 1.8°), coronal femoral (90.2° ± 1.6° vs 89.8° ± 1.9°) and tibial component (90.2° ± 1.6° vs 90.3° ± 1.7°) alignment and outlier rates (6.2% vs 7.5%) was found between non-obese and obese individuals. Similarly, alignment and the outlier rates were similar when non-obese individuals and a subgroup of morbidly obese individuals (BMI N40 kg/m²) were compared. Conclusions: Computer navigation can achieve excellent limb and component alignment irrespective of a patient's BMI. Although obesity may not be an indication per se for using computer navigation during TKA, it will help achieve consistently accurate limb and component alignment in obese patients. Level of Evidence: Level II [ABSTRACT FROM AUTHOR]

Purpose: This prospective study aimed to evaluate radiographically, mechanical or hip-knee-ankle (HKA) axis in healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to determine the incidence of inherent varus (mechanical limb alignment of N3° varus) and the factors influencing it. Methods: Three hundred and eighty-eight lower limbs were evaluated using full length, standing hip-to-ankle radiographs in 198 healthy, asymptomatic, Asian (Indian and Korean) adults between 20 and 40 years of age to assess the hip-knee-ankle (HKA) angle, medial proximal tibial angle (MPTA), femoral bowing and femoral neck-shaft angle to determine the incidence of inherent varus (mechanical limb alignment of N3° varus) and the factors influencing it. Results: Overall, the mean HKA angle was 177.6° ± 2.6° with 34.5% of limbs in inherent varus (mean HKA angle 174.9° ± 1.8°). The incidence of inherent varus was significantly higher (p = 0.01) in males (40%) compared to females (28%) but similar among Indian (34%) and Korean subjects (35%). The hip-knee-ankle (HKA) angle showed significant positive correlation (r= 0.82, pb 0.001) with only the medial proximal tibial angle (MPTA). Conclusions: Inherent varus alignment of the lower limb is fairly common among asymptomatic, Asian adults. These results raise several pertinent questions regarding the role of inherent varus in the aetiopathogenesis of knee osteoarthritis and in lower limb realignment procedures. [ABSTRACT FROM AUTHOR]

Computer navigation enables the surgeon to accurately quantify deformity and gap balance during total knee arthroplasty (TKA), ensuring greater accuracy in component alignment, full correction of deformity, and well-balanced gap throughout the range of knee motion. This translates into significant improvements in clinical function and may result in increased long-term survival of the implant. Computer navigation in TKA may be even more useful in knees with complex deformities, extra-articular deformities, and in the obese. Hence, navigation complements the surgeon''s skill to provide an unbeatable combination of technique and technology in TKA to ensure that all goals of the surgical procedure are achieved. [Copyright &y& Elsevier]

Abstract: One hundred twenty-two consecutive minimally invasive Oxford phase 3 medial unicompartmental knee arthroplasties in 109 patients were evaluated for postoperative limb alignment and the influence of factors such as preoperative limb alignment, age, body mass index, sex, insert thickness, and surgeon''s experience. The mean mechanical preoperative hip-knee-ankle (HKA) angle of 172.2° ± 3.1° improved to 177.1° ± 2.9° postoperatively. In 75% of the limbs, the HKA angle was restored to within an acceptable alignment of 177° ± 3°, 14% of the limbs were in excessive varus (<174°), and 11% were in valgus (>180°). Only preoperative HKA angle was predictive of postoperative HKA angle. Although most of the limbs had acceptable limb alignment after unicompartmental knee arthroplasty, limbs with more severe preoperative varus deformity had a tendency to remain in excessive varus, and limbs with lesser preoperative varus deformity had a greater tendency to go into valgus postoperatively. [Copyright &y& Elsevier]

Abstract: Despite several advantages of medial opening wedge high tibial osteotomy, this procedure has been noted to have a high rate of complications especially with the use of a spacer plate for fixation. We retrospectively evaluated the early complications of 138 medial opening wedge high tibial osteotomies done using autologous tricortical iliac bone graft and T-plate fixation(AO locking compression T-plate, Ti/3H 4.5–5.0mm, Synthes, Switzerland, Model No. 440.131 in 30 and low-profile locking T-plate and low-profile locking T-plate in 128 patients. At a mean follow-up of 36.8months (13 to 78), 26 knees (18.8%) developed complications. Complications varied from osteotomy site infection, loss of correction, broken screws and lateral tibial plateau fracture to joint fluid leakage, pseudoaneurysm and iliac bone fractures. Using the “safe zone” technique and penetrating the lateral cortex with Steinmann pins may help to avoid complications such as loss of correction and lateral tibial plateau fractures. The results of this study indicate that medial opening wedge high tibial osteotomy using autologous tricortical iliac bone graft and T-plate fixation may be a technically demanding procedure associated with a moderate rate of complications. However, these complications could be minimized with proper planning, adequate intra-operative precautions and few modifications to avoid technical error. [Copyright &y& Elsevier]

Abstract: Whether simultaneous bilateral TKAs (SBTKAs) are more painful and the postoperative functional recovery slower compared to staged bilateral TKAs or unilateral TKAs are issues that frequently concerns patients. The purpose of the current study was to compare the early postoperative pain, function and recovery in simultaneous bilateral versus unilateral computer-assisted TKA. In this prospective study, 50 consecutive patients undergoing unilateral computer-assisted total knee arthroplasties (TKAs) were compared with 50 consecutive patients undergoing SBTKAs in terms of pain, length of hospital stay and rehabilitative milestones during the immediate postoperative period. The mean visual analogue pain scores, mean knee range of motion, straight leg raising and extensor lag were equal in both the groups at the time of discharge. Patients in the SBTKA group lagged behind the unilateral group in stick walking by approximately 24 h. The results of this study demonstrate excellent pain relief and functional recovery with simultaneous bilateral computer-assisted TKAs comparable to unilateral TKAs. Patients eligible for bilateral TKAs can undergo them simultaneously without excessive pain or slower functional outcome. [Copyright &y& Elsevier]

Abstract: Extensive release of posterolateral structures may be required to correct rigid and severe valgus deformities during total knee arthroplasty. Current techniques are technically difficult, may not accurately restore soft tissue balance, and are associated with postoperative complications. Computer navigation while performing lateral femoral epicondylar osteotomy allows precise, controlled, quantitative lengthening of lateral structures and restoration of optimum soft tissue balance and alignment. [Copyright &y& Elsevier]

Background: Distraction-resisting forces that are generated during distraction osteogenesis can be responsible for complications, including a lag effect on fibular distraction leading to a tibiofibular distraction difference, tibial axial deviation, and distraction at the proximal and distal tibiofibular joints. We investigated the nature of distraction-resisting forces by studying their correlation with these parameters. Methods: One hundred and eleven tibial lengthening procedures in sixty-three patients were chosen. Seventy-six segments underwent lengthening with an llizarov ring fixator, and thirty-five segments had lengthening over an intra-medullary nail. Serial radiographs were evaluated with regard to the amounts of tibiofibular distraction difference, proximal tibiofibular joint distraction, distal tibiofibular joint distraction, tibial axial deviation, and heel malalignment. Clinically, laxity at the knee was evaluated and fibular head instability was assessed. Variations in all of these parameters were evaluated with respect to tibiofibular joint fixation, etiology, skeletal maturity, lengthening over an intramedullary nail, and amount of lengthening. Results: The mean tibiofibular distraction difference was 19.1 ± 10.6 mm (range, 2 to 51 mm), the mean proximal tibiofibular joint distraction was 10.1 ± 6.8 mm (range, 0 to 33 mm), and the mean tibial valgus angulation was 8.7° ± 4.4°. At the time of the latest follow-up, twenty-eight segments (25%) had lateral knee joint laxity at 300 of knee flexion and eight segments (7%) had fibular head subluxation at 90° of knee flexion. Twenty-four (86%) of the twenty-eight cases of knee laxity were observed in skeletally immature patients. The tibiofibular distraction difference, proximal tibiofibular joint distraction, and tibial valgus angulation were significantly greater in the group without fixation of the proximal tibiofibular joint. A significant decrease in the tibial valgus angulation and knee laxity was found in patients with lengthening over an intramedullary nail. In the intramedullary nail group, after fixation of the proximal tibiofibular joint, the tibiofibular distraction difference and the proximal tibiofibular joint distraction decreased; however, the proportion of cases with clinically important tibial valgus angulation (>10°) increased significantly. Conclusions: Fixing both tibiofibular joints with a single llizarov wire decreases proximal tibiofibular joint distraction; however, more secure fixation would help to decrease the prevalence of delayed knee laxity. When tibial lengthening is performed over an intramedullary nail, avoiding proximal tibiofibular joint fixation will limit tibial valgus angulation. Limiting lengthening to <25% will decrease the proportion of cases with knee laxity, and limiting lengthening to <50% will significantly limit tibial valgus angulation. [ABSTRACT FROM AUTHOR]

Abstract: Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals. [Copyright &y& Elsevier]

Irreducible knee dislocation due to incarcerated soft tissue structures in associated fractures is extremely uncommon. We report a case of irreducible, closed dislocation of the knee secondary to incarcerated patellar tendon in a Hoffa fracture (unicondylar fracture of femur in the coronal plane) with associated communited fracture of patella and disruption of both cruciates. We treated this case initially with open reduction and internal fixation of fracture and repair of the patellar tendon. During the total followup period of eighteen months, the patient had restricted joint range of motion with no joint instability despite aggressive physiotherapy and further surgical intervention. The prognosis of such complex knee injuries with combination of ligamentous injuries and associated fractures is much worse when compared to either injuries alone. [ABSTRACT FROM AUTHOR]

Abstract: An isolated symptomatic posterior cruciate ligament cyst is uncommon, and extra-articular communication of this cyst is extremely rare. We report a case of a symptomatic communicating posterior cruciate ligament cyst presenting as a central popliteal mass. In view of the large extra-articular extension of this cyst and its close proximity to the popliteal neurovascular structures, we successfully treated this cyst with a combined arthroscopic and open approach. [Copyright &y& Elsevier]

Objectives: The aim of this retrospective study was (1) to evaluate the radiographic features to differentiate arthroscopically confirmed complete and incomplete discoid lateral meniscus (DLM) (2) to determine the cutoff values for any parameter that was found to differentiate complete from incomplete DLM. Materials and Methods: We retrospectively analyzed plain knee radiographs of 130 arthroscopically proven DLM. Seventy-nine patients had complete DLM and 51 patients incomplete DLM. Knee radiographs from 52 patients with arthroscopically proven normal lateral meniscus acted as control group. Radiographic parameters measured included fibular height, lateral joint space, condylar cutoff sign, height of lateral tibial spine, obliquity of lateral tibial spine, squaring of the lateral femoral condyle, and cupping of the lateral tibial plateau. Results: Among radiographic parameters, high fibular head, widening of the lateral joint space and femoral condylar cutoff sign showed statistically significant (p < 0.0001) differences between complete and incomplete DLM. At specific threshold points of fibular height< 11mm, lateral joint space > 6mm and condylar cutoff sign< 0.80, the diagnosis of complete DLM revealed 87.3% sensitivity, 81.6% specificity and 78.4% positive predictive value (PPV) for the fibular height, 81.0% sensitivity, 86.6% specificity and 83.1% PPV for the lateral joint space, and 86.1% sensitivity, 83.5% specificity and 80% PPV for the condylar cutoff sign. Conclusions: Radiographic features of fibular height, lateral joint space and condylar cut off sign can be used for screening of a complete type of DLM. However, radiographs are not a reliable screening tool for an incomplete DLM. Level of evidence: IV, Case Series [ABSTRACT FROM AUTHOR]