Aims

The aim of this study was to investigate the distribution of phenotypes in Asian patients with end-stage osteoarthritis (OA) and assess whether the phenotype affected the clinical outcome and survival of mechanically aligned total knee arthroplasty (TKA). We also compared the survival of the group in which the phenotype unintentionally remained unchanged with those in which it was corrected to neutral.

Aims

A fracture of the medial tibial plateau is a serious complication of Oxford mobile-bearing unicompartmental knee arthroplasty (OUKA). The risk of these fractures is reportedly lower when using components with a longer keel-cortex distance (KCDs). The aim of this study was to examine how slight varus placement of the tibial component might affect the KCDs, and the rate of tibial plateau fracture, in a clinical setting.

Despite multiple published reviews, the optimum method of correction and stabilisation of Blount's disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. This technique was developed to minimise cost in a context of limited resources. This study was conducted between 2016 and 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32tibiae) who had correction of late-onset tibia by proximal tibial osteotomy and Ilizarov external fixator. All cases were followed up to 2 years. The mean proximal tibial angle was 65.7° (±7.8) preoperatively and 89.8° (±1.7) postoperatively. The mean mechanical axis deviation improved from 56.2 (±8.3) preoperatively to 2.8 (±1.6) mm postoperatively. The mean femoral-tibial shaft angle was changed from – 34.3° (±6.7) preoperatively to 5.7° (±2.8) after correction. Complications included overcorrection (9%) and pin tract infection (25%). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity. This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities

Aims

The aim of this study was to compare robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) in order to determine the changes in the anatomy of the knee and alignment of the lower limb following surgery.

Aims

Cementless unicompartmental knee arthroplasty (UKA) has advantages over cemented UKA, including improved fixation, but has a higher risk of tibial plateau fracture, particularly in Japanese patients. The aim of this multicentre study was to determine when cementless tibial components could safely be used in Japanese patients based on the size and shape of the tibia.

Aims. The aims of this retrospective study were to determine the incidence of extra-articular deformities (EADs), and determine their effect on postoperative alignment in knees undergoing mobile-bearing, medial unicompartmental knee arthroplasty (UKA). Patients and Methods. Limb mechanical alignment (hip-knee-ankle angle), coronal bowing of the femoral shaft and proximal tibia vara or medial proximal tibial angle (MPTA) were measured on standing, full-length hip-to-ankle radiographs of 162 patients who underwent 200 mobile-bearing, medial UKAs. Results. Incidence of EAD was 7.5% for coronal femoral bowing of >5°, 67% for proximal tibia vara of >3° (MPTA<87°) and 24.5% for proximal tibia vara of >6° (MPTA<84°). Mean postoperative HKA angle achieved in knees with femoral bowing ≤5° was significantly greater when compared to knees with femoral bowing >5° (p=0.04); in knees with proximal tibia vara ≤3° was significantly greater when compared to knees with proximal tibia vara >3° (p=0.0001) and when compared to knees with proximal tibia vara >6° (p=0.0001). Conclusion. Extra-articular deformities are frequently seen in patients undergoing mobile-bearing medial UKAs, especially in knees with varus deformity>10°. Presence of an EAD significantly affects postoperative mechanical limb alignment achieved when compared to limbs without EAD and may increase the risk of limbs being placed in varus>3° postoperatively. Clinical Relevance. Since the presence of an EAD, especially in knees with varus deformity>10°, may increase the risk of limbs being placed in varus>3° postoperatively and may affect long-term clinical and implant survival outcomes, UKR in such knees should be performed with caution

Aims

To present our experience of using a combination of intra-articular osteotomy and external fixation to treat different deformities of the knee.

Introduction. Three anatomic landmarks are typically used to estimate proper femoral component rotation in total knee arthroplasty: the transepicondylar axis (TEA), Whiteside's line, and the posterior condylar axis (PCA). Previous studies have shown that the presence of tibia vara may be accompanied by a hyperplastic posteromedial femoral condyle, which affects the relationship between the PCA and the TEA. The purpose of this study was to determine the relationship of tibia vara with the PCA. Methods. Two hundred and forty-eight knees underwent planning for total knee arthroplasty with MRI. The MRI was used to characterize the relationship between the transepicondylar axis and the posterior condylar axis. Long-leg standing films (LLSF) were obtained to evaluate the medial proximal tibial angle. The MPTA is defined as the medial angle formed between a line along the anatomic axis of the tibia and a line along the tibial plateau. Results. There were 168 knees in varus and 80 in valgus. The PCA in the patient group was 2.38 degrees ± 1.6 degrees. Regression analysis of tibial varus compared to the PCA showed a small association where for each degree of tibial varus, there was an additional 0.07 degrees of internal rotation of the PCA (p = 0.01). When defining tibia vara as a MPTA <84 degrees, there was no difference between patients with and without tibia vara (p=0.0661) although there was a trend toward a smaller PCA with increased tibia vara. When defining tibia vara as a MPTA <82 degrees there was again no difference in PCA between patients with and without tibia vara (p=0.825). Conclusion. Tibia vara did not influence the PCA to a clinically significant degree. This result is in contrast to previous studies which indicated that increased tibial varus correlated to increased internal rotation of the PCA with respect to the TEA

Objective. Tibia vara seen in Japanese patients reportedly influences the tibial component alignment when performing TKA. However, it is unclear whether tibia vara affects the component position and size selection. We therefore determined (1) the amount of medial tibial bow, (2) whether the tibia vara influences the aspect ratio of the tibial resected surface in aligning the tibial component with the tibial shaft axis (TSA), and (3) whether currently available tibial components fit the shapes of resected proximal tibias in terms of aspect ratio. Material and Methods. The study was performed using CT data from 90 lower limbs in 74 Japanese female patients with primary varus knee OA, scheduled for primary TKAs between January 2010 and March 2012. We measured the tibia vara angle (TVA; the angle between the TSA and the tibial mechanical axis), proximal varus angle (PVA; angle between the TSA and the line connecting the center of the tibial eminence and the center of the proximal 1/3 of the tibia) using three-dimensional preoperative planning software [Fig.1]. Then the mediolateral and middle AP dimensions of the resected surface when the tibial component was set so that its center aligned with the TSA was measured. We determined the correlations of the aspect ratio (the ML dimension divided by the AP dimension) of the resected surface with TVA or PVA and compared the aspect ratios to those of five prosthesis designs. Results. The mean TVA and PVA were 0.6° and 2.0°, respectively. The aspect ratio negatively correlated with both TVA and PVA (r = −0.53 and −0.55, respectively) [Fig. 2, 3]. The mean aspect ratio of the resected surface was 1.48 but gradually decreased with increasing AP dimension, whereas four of the five prostheses had a constant aspect ratio. Conclusions. The aspect ratio of resected tibial surface was inversely correlated to the degree of tibia vara, and currently available prosthesis designs do not fit well to the resected surface in terms of aspect ratio

This review explores recent advances in fixator design and used in contemporary orthopaedic practice including the management of bone loss, complex deformity and severe isolated limb injury.

Background:. Tibia Vara (Blount's disease) is characterized by a growth disturbance of the posteromedial proximal tibial physis. This results in the typically complex tibial deformity of varus, procurvatum and internal tibial torsion. Knee instability is due to medial tibial joint depression and lateral ligament complex attenuation. Femoral angular and rotational deformity are associated features. Obesity often complicates management. Langenskiöld observed six stages of the disorder on X-ray (stage 6 not occurring before 9 years) and obtained good results with proximal tibial realignment osteotomy if performed before the age of 8 years. Our experience is very different. Purpose:. To evaluate our experience with treatment of a consecutive cohort of patients with early onset Blount's disease in terms of clinical findings, recurrence rate and factors associated with recurrence and treatment methods and indications. Methods:. A retrospective chart and imaging review was completed of 100 extremities (58 patients) treated surgically for early onset Blount's disease. Follow-up ranged between 1 and 7 years. Results:. These children all presented with a history of onset of deformity between the ages of 1 and 3 years. Their age at first treatment varied between 2 and 10 years. Langenskiöld stage V and VI occurred in younger patients than originally described. The recurrence rate of extremities treated with simple osteotomy was 42% (25/58). Factors associated with recurrence include age >4 (p<0.001), obesity (p=0.007), instability (p=0.003), severity of deformity (femoro-tibial angle) (p<0.001), medial physeal slope (p<0.001) and advanced Langenskiöld stage (p<0.001). Surgical treatment included the use of growth retardation alone, dome realignment osteotomy with and without growth retardation, oblique proximal tibial (Rab) osteotomy, 3-in-1 procedure (medial elevation, tibial osteotomy and lateral epiphyseodesis) and gradual correction with hexapod fixators was used in some recurrent cases. In addition we describe a new surgical technique which obtains acute deformity correction at the level of the growth plate. Conclusion:. We propose that the disease follows a more aggressive course in the black population of Kwa-Zulu Natal, South Africa. The management is often complex and recurrence is not uncommon

Background:. Recurrent or late presenting Tibia Vara is a complex clinical problem. In addition to the multiplanar deformity the disorder is often accompanied by obesity. Simple re-alignment osteotomy with acute correction is effective early in the disease. Its use in recurrent or severe deformities is limited by geometric constraints (mechanical axis translation), difficult fixation and the risk of compartment syndrome. Gradual correction with external fixation devices is a well-accepted technique in these cases. It has been shown to obtain accurate correction and provides stable fixation. This allows early weight bearing which facilitate consolidation and rehabilitation. Hexapod fixators are technically less demanding than standard Ilizarov techniques. The TLHex is a relatively new hexapod fixator available in South Africa. Frame pre-assembly allows easier mounting on a limb with complex deformity. The software allows for non-orthogonal mounting, which simplifies frame-mounting assessment. Double telescoping struts allow greater strut excursion and the outside mounting of struts on the ring increases mounting options for fixation elements. This is the first report on its use in Blount's disease. Purpose:. Evaluation of the result of gradual correction with the TLHex external fixator in Blount's disease in terms accuracy of correction, union and complications. Illustration of key hardware and software features. Methods:. A retrospective chart and X-ray review of 7 patients (9 legs) treated by gradual correction with the TLHex external fixator was performed. The degree of correction of varus and procurvatum was assessed on pre-operative and post-correction X-rays. Internal rotation deformity correction was assessed clinically. Complications such as neurovascular compromise, minor and major pin tract infection and hardware complications were documented. The pre-operative planning, surgical technique and post-operative treatment protocol is reviewed. Results:. Mean varus was corrected from 21° (17° to 45°) to 1°(−2° to 4°). Mean procurvatum was corrected from 8° (0° to 25°) to 0° (0° to 8°). Internal rotation was corrected to between 5° to 10° of external rotation in all patients. The mean time in the frame was 112 days. Three patients needed one additional program to correct residual deformity (one over-corrected coronal aligment, one under-corrected saggital alignment and one rotational over-correction). Three patients required oral antibiotics for minor pin tract infection. One patient required intravenous antibiotics and wire removal for major pin tract infection. One patient required frame adjustment after correction for soft tissue impingement. One strut loosened after consolidation prior to frame removal. Conclusion:. Gradual correction of Tibia Vara with the TLHex external fixator is a safe and effective treatment method

Although proximal tibia vara is physiologically and pathologically observed, it is difficult to measure the varus angle accurately and reproducibly due to inaccuracy of the radiograph because of rotational and/or torsional deformities. Since tibial coronal alignment in TKA gives influence on implant longevity, intra- or extra-medurally cutting guide should be set carefully especially in cases with severe tibia vara. In this context, we measured the proximal tibial varus angle by introducing 3D-coordinate system. Materials & Methods. Three-dimensional models of 32 tibiae (23 females, 9 males, 71.2 ± 7.8 y/o) were reconstructed from CT data of the patients undergoing CT-based navigation assisted TKA. Clinically relevant mid-sagittal plane is defined by proximal tibial antero-posterior axis and an apex of the tibial plafond. After the cross-sectional contours of the tibial canal were extracted, least-square lines were fitted to define the proximal diaphyseal and the metaphyseal anatomical axis. The proximal tibia vara was firstly investigated in terms of distribution of proximal anatomical axis exits at the joint surface. TVA1 and TVA2 were defined to be a project angle on the coronal plane between the metaphyseal tibial anatomical axis and the proximal diaphyseal anatomical axis, and that between the metaphyseal tibial anatomical axis and the tibial functional axis, respectively. The correlations of each angle with age and femoro-tibial angle (FTA) were also examined. Results. The proximal anatomical axis exits distributed 4.3 ± 1.7 mm medially and 17.1 ± 3.4 mm anteriorly. TVA1 and TVA2 were 12.5 ± 4.5°(4.4?23.0°) and 11.8 ± 4.4° (4.4?22.0°), respectively. The correlations of FTA with TVA1 (r=0.374, p<0.05) and TVA2 (r=0.439, p<0.05) were statistically significant. Discussion. This is the first study that analyses tibia vara in the 3D-algorythm and that investigates its correlations with FTA. In the coronal plane, proximal tibia was actually varus, and TVA varied substantially among patients and correlated with FTA. These data implicated that TVA was involved in the pathophysiology of osteoarthritic deformities, directly or indirectly. Also tibia vara should be considered while placing the instrument to cut proximal tibia to obtain optimal setting of the implant in TKA

Introduction. We report 3 cases from different centres of infantile tibia vara in which the deformity was due to slippage of the proximal tibial epiphysis on the metaphysis; the aim of this study was to define the features of this previously unreported condition, and their implications for management. Method. Three cases of tibia vara secondary to atraumatic slippage of the upper tibial epiphysis on the metaphysis were identified from three different centres. The case notes and imaging studies were retrospectively reviewed to distinguish common clinical and radiographic features. Results. There were one male and two females, all of non-Caucasian origin, (age 3–7 years). All patients' weights were above the 97th centile for age. In all cases there was an infero-medial subluxation of the tibial epiphysis over a dome shaped proximal tibial metaphysis, with disruption of continuity between their lateral borders. The height of the medial tibial plateau was preserved in all cases. New bone formation suggests this is a chronic process. The evolution of one case indicates that pathogenesis is shared with infantile Blount's disease. A gradual deformity correction was performed in all cases using circular external fixation, with the proximal ring secured to both the proximal epiphysis and metaphysis. Conclusion. Slipped upper tibial epiphysis is an uncommon but distinct cause of tibia vara. The radiological features are completely different from those previously described for infantile tibia vara and not encompassed by the existing classification. The unusual morphology has consequences for treatment. Management is analogous to a slipped upper femoral epiphysis – the physis has to be stabilized to the metaphysis and an osteotomy performed to restore the mechanical axis. We believe this is best achieved with a circular external fixator because this permits multiaxial correction including translation and rotation

Background. Adequate rotation of femoral component in total knee arthroplasty(TKR) is mandatory for preventing numerous adverse sequelae. The transepicondylar axis has been a well-accepted reference for femoral component rotation in the measured resection technique. In this technique, measured resection is performed referenced off the tibial cut - perpendicular to the tibial mechanical axis with the knee in 90 ° of flexion. However, to the best of our knowledge, it is not known whether this technique apply well to a knee with tibia vara. This study evaluates the reliability of the transepicondylar axis as a rotational landmark in knees with tibia vara. Methods. We selected 101 osteoarthritis knees in 84 symptomatic patients(mean age: 69.24 ± 5.68) with proximal tibia vara (Group A). Group A was compared with 150 osteoarthritic knees without tibia vara in 122 symptomatic patients (mean age: 69.51 ± 6.01) (Group B). The guide line for selection of all these knees were based on the degree of tibia vara angle (TVA) which was formed by line perpendicular to epiphysis and by anatomical axis of the tibia - all measured in radiographs of the entire lower limb. Magnetic resonance imaging (MRI) axial images with most prominent part of both femoral condyles were used for measurement of transepicondylar axis(TE), anteroposterior axis(AP) and posterior condylar axis(PC). Results. The mean TVA of group A was 8.94° ± 3.11 and group B was 1.24° ± 0.85. The TE line in Group A showed 6.09 ° ± 1.43 of external rotation, relative to PC. This did not show statistical difference compared with 5.95 ° ± 1.58 in Group B (p=0.4717). The AP line in Group A showed 6.06 ° ± 1.93 of external rotation, relative to the line perpendicular to PC. This was statistically significant when compared to 5.44 ° ± 2.13 in Group B (p=0.020). Conclusion. There is no difference between knees without tibia vara compared those with tibia vara with regards to transepicondylar axis. In addition, both groups have almost identical external rotation of approximately 6 °. The AP axis was only approximately 0.5 ° difference between the two groups. The distal femoral geometry was not affected by tibia vara deformity, that is, there were no hypoplastic or hyperplastic deformities of medial femoral condyle in osteoarthritic knees with tibia vara. The use of transepicondylar axes in determining femoral rotation may produce flexion asymmetry in knees with proximal tibia vara. So, It should be pointed out that more attention should be paid on femoral component rotation and flexion gap balancing in knees with proximal tibial vara

We describe three cases of infantile tibia vara resulting from an atraumatic slip of the proximal tibial epiphysis upon the metaphysis. There appears to be an association between this condition and severe obesity. Radiologically, the condition is characterised by a dome-shaped metaphysis, an open growth plate and disruption of the continuity between the lateral borders of the epiphysis and metaphysis, with inferomedial translation of the proximal tibial epiphysis. All patients were treated by realignment of the proximal tibia by distraction osteogenesis with an external circulator fixator, and it is suggested that this is the optimal method for correction of this complex deformity. There are differences in the radiological features and management between conventional infantile Blount’s disease and this ‘slipped upper tibial epiphysis’ variant.

Any intervention for limb with compromised bone and soft tissue in paediatric age group is often studded with complications of flare of infection, wound breakdown, delayed healing or failure of grafting. We report our experience with managing 8 such cases with periosteal sleeve taken from tibia along with fibular grafting. The lesion was gap non-union following bone sequestration in 7 cases (2 proximal humerus; 4 femur and one metacarpal) and one case tibia vara in post osteomyelitic tibia. The infective lesions were silent for minimum of 1 year before this procedure. The periosteal sleeve was taken from proximal tibia and fibular graft was also procured from same leg. Following freshening of bone ends, the fibular graft was applied at non-union/osteotomy site and enclosed in the freshly harvested periosteal sleeve. The limb was protected in plaster cast for 6 weeks and assessed clinicoradiologically at 3 and 6 weeks intervals. Uneventful union followed in 7 cases in 6 weeks time. In one case of proximal humerus, the osteosynthesis attempt failed. The periosteal and fibular graft site posed minimal morbidity for the child. Conclusions. Periosteal sleeve and fibular grafting offers a promising alternative for interventions in post osteomyelitic bone with compromised soft tissue