We retrospectively reviewed the records of 1150 computer-assisted total knee replacements and analysed the clinical and radiological outcomes of 45 knees that had arthritis with a pre-operative recurvatum deformity. The mean pre-operative hyperextension deformity of 11° (6° to 15°), as measured by navigation at the start of the operation, improved to a mean flexion deformity of 3.1° (0° to 7°) post-operatively. A total of 41 knees (91%) were managed using inserts ≤ 12.5 mm thick, and none had mediolateral laxity > 2 mm from a mechanical axis of 0° at the end of the surgery. At a mean follow-up of 26.4 months (13 to 48) there was significant improvement in the mean Knee Society, Oxford knee and Western Ontario and McMaster Universities Osteoarthritis Index scores compared with the pre-operative values. The mean knee flexion improved from 105° (80° to 125°) pre-operatively to 131° (120° to 145°), and none of the limbs had recurrent recurvatum. These early results show that total knee replacement using computer navigation and an algorithmic approach for arthritic knees with a recurvatum deformity can give excellent radiological and functional outcomes without recurrent deformity

Aims. There is little information about how to manage patients with a recurvatum deformity of the distal tibia and osteoarthritis (OA) of the ankle. The aim of this study was to evaluate the functional and radiological outcome of addressing this deformity using a flexion osteotomy and to assess the progression of OA after this procedure. Patients and Methods. A total of 39 patients (12 women, 27 men; mean age 47 years (28 to 72)) with a distal tibial recurvatum deformity were treated with a flexion osteotomy, between 2010 and 2015. Nine patients (23%) subsequently required conversion to either a total ankle arthroplasty (seven) or an arthrodesis (two) after a mean of 21 months (9 to 36). A total of 30 patients (77%), with a mean follow-up of 30 months (24 to 76), remained for further evaluation. Functional outcome, sagittal ankle joint OA using a modified Kellgren and Lawrence Score, tibial lateral surface (TLS) angle, and talar offset ratio (TOR) were evaluated on pre- and postoperative weight-bearing radiographs. Results. Postoperatively, the mean score for pain, using a visual analogue scale, decreased significantly from 4.3 to 2.5 points and the mean American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score improved significantly from 59 to 75 points (both p < 0.001). The mean TLS angle increased significantly by 6.6°; the mean TOR decreased significantly by 0.24 (p < 0.001). Radiological evaluation showed an improvement or no progression of sagittal ankle joint OA in 32 ankles (82%), while seven ankles (18%) showed further progression. Conclusion. A flexion osteotomy effectively improved the congruency of the ankle joint. In 30 patients (77%), the joint could be saved, whereas in nine patients (23%), the treatment delayed a joint-sacrificing procedure. Cite this article: Bone Joint J 2019;101-B:682–690

Genu recurvatum deformity is uncommon in arthritic knees undergoing total knee arthroplasty (TKA). We retrospectively analysed radiographs and navigation data to determine the clinical and radiographic results of computer-assisted TKA in knee arthritis with recurvatum deformity. Based on alignment data obtained during computer assisted (CAS) TKA, 40 arthritic knees (36 patients) with a recurvatum deformity of at least 5° were identified. The mean recurvatum deformity was 8.7° (6° to 14°). On preoperative standing hip-ankle radiographs, 23 limbs (57.5%) had a mean varus deformity of 169.4° (153° to 178°) and 17 limbs had a mean valgus deformity of 189.2° (182° to 224°). The intraoperative navigation data showed mean tibial resection of 7.5mm (4.6 to 13.4mm) and distal femur resection of 7.5mm (3.3 to 13mm) with a mean final extension gap of 21.2mm and a flexion gap at 90° of 21.1mm and on extension. On table, the mean knee deformity in sagittal plane was 3° flexion (1.5° to 4.5° flexion). Postoperatively, the mean HKA angle on standing hip-ankle radiographs was 179.2° (177° to 182°). On postoperative lateral radiographs, joint line in extension was moved distally in 35 limbs by 2.3mm (0.3 to 4mm) and proximally in 5 limbs by 2.2mm (2.2 to 2.4mm); the mean preoperative posterior femoral offset of 28.7 mm changed to 27.9 mm postoperatively. At a mean follow up 28 months (14- 48 months) the knee, function, and pain scores improved by 61, 48, and 28 points, respectively and there was no recurrence of recurvatum deformity at final follow up. Genu recurvatum is a notoriously difficult condition to address at TKA. The challenges are to be able to detect it at surgery and take appropriate measures in terms of resection and releases to correct it satisfactorily. Computer assisted TKA helps to achieve excellent deformity correction, limb alignment, gap balancing and function in patients with recurvatum deformity by accurately quantifying and helping to modify the amount of bone cuts and titrate soft tissue release

To describe a simple effective technique of opening wedge tibial osteotomy for the treatment of recurvatum (hyperextension) instability of the knee. Recurvatum instability of the knee occurs in patients with pathological hyperextension. There are three patterns of recurvatum instability:-. Acquired bony deformity of the proximal tibia (growth plate arrest or fracture malunion). Pathological laxity of the posterior capsule of the knee. This may occur without damage to the cruciate ligaments. A combination of bony and soft tissue pathology. All three patterns are best treated by an opening wedge tibial osteotomy at the level of the tibial tubercle. A simple surgical technique is described that does not require detachment of the tibial tubercle. The necessary degree of correction is easily assessed clinically during surgery. The technique has been used with success in 8 patients. The Puddu tooth plate provides ideal fixation. Iliac crest cortico-cancellous wedge bone grafts have been used in all cases

Congenital or acquired recurvatum genu might be caused by bone and/or soft tissue disorders. In bone recurvation, tibial deformity is more common; femoral deformity has clinical and X-ray features that are less important and often unidentified. We found this type of deformity in only four of 40 cases of bone recurvation. Bone recurvation can follow a tibial or femoral fracture as well as injury with no X-ray signs. Some months later an anterior epiphysiolisis might be recognised on X-ray. This fact allows a retrospective diagnosis of fifth type Salter-Harris epiphysiolisis. Clinically a harmonious recurvatum genu would be recognised, which is difficult to distinguish from a capsulo-ligamentous disorder. According to a subjective profile, it is featured with no objective laxity. On X-rays there are no peculiarities in the anterior view, but on the lateral view femoral condylar flattening with anterior rotation, in particular in the lateral one, can be observed. It might be useful to compare the X-ray findings to define a geometrical point termed the femoral diaphysealintercondylar angle. This has been already described and is measured between two lines, one which represents the axes of the femoral shaft, the other one the Blumensaat line; in a normal knee this angle measures 33° (±3). In knees with femoral recurvation this is higher: in our four patients the range of the angle was 45°–58°. Procurving femoral osteotomy is the gold standard; in fact femoral closed wedge osteotomy allows a complete correction. Surgeons must avoid an overcorrection with subsequent femoral trochlear rotation and at the same time a tibial osteotomy must be avoided, which would lead to a double articular deformity, wherever it would fit with a capsulo-ligamentous recurvation

Recurvatum genu can develop as a results of both chronic diseases “maladie des enfants alités” (Lefort), though rarely, and after trauma, which occurs more often. Surgical treatment might consist either in a de-epiphysiodesis according to Langenskield, when a bone bridge is present, or by Ilizarov technique, which allows a correction of segmentary shortening. This kind of trauma often occurs after bone growth has ceased and this is why in our study we performed osteotomies. Femoral osteotomies are all closed wedge procedures with medial access and 90° angle blade-plate fixation. This allows early mobilisation and avoids overcorrection. Without performing this kind of procedure posteriorisation of the trochlea might occur and, consequently, over time, patellofemoral arthritis could develop. For the tibia we applied an anterior open wedge osteotomy with ATT avulsion, according to Lecuire, with which secondary low patella can be avoided. As fixation we first used screws, actually a plate to correct the co-existing valgus. The good results of this kind of surgery justify autologus bone graft. We have not employed the the procedure described by Bowen

Aims

Knowledge on total knee arthroplasties (TKAs) in patients with a history of poliomyelitis is limited. This study compared implant survivorship and clinical outcomes among affected and unaffected limbs in patients with sequelae of poliomyelitis undergoing TKAs.

Intra-articular resection of bone with soft-tissue balancing and total knee replacement (TKR) has been described for the treatment of patients with severe osteoarthritis of the knee associated with an ipsilateral malunited femoral fracture. However, the extent to which deformity in the sagittal plane can be corrected has not been addressed. We treated 12 patients with severe arthritis of the knee and an extra-articular malunion of the femur by TKR with intra-articular resection of bone and soft-tissue balancing. The femora had a mean varus deformity of 16° (8° to 23°) in the coronal plane. There were seven recurvatum deformities with a mean angulation of 11° (6° to 15°) and five antecurvatum deformities with a mean angulation of 12° (6° to 15°). The mean follow-up was 93 months (30 to 155). The median Knee Society knee and function scores improved from 18.7 (0 to 49) and 24.5 (10 to 50) points pre-operatively to 93 (83 to 100) and 90 (70 to 100) points at the time of the last follow-up, respectively. The mean mechanical axis of the knee improved from 22.6° of varus (15° to 27° pre-operatively to 1.5° of varus (3° of varus to 2° of valgus) at the last follow-up. The recurvatum deformities improved from a mean of 11° (6° to 15°) pre-operatively to 3° (0° to 6°) at the last follow-up. The antecurvatum deformities in the sagittal plane improved from a mean of 12° (6° to 16°) pre-operatively to 4.4° (0° to 8°) at the last follow-up. Apart from varus deformities, TKR with intra-articular bone resection effectively corrected the extra-articular deformity of the femur in the presence of antecurvatum of up to 16° and recurvatum of up to 15°

Introduction. Genu recurvatum is a deformity rarely seen in patients receiving total knee arthroplasty. This deformity is defined as hyperextension of the knee greater than 5°. The incidence of recurvatum has been cited in the literature as less than 1%. Purpose. The purpose of this study was to report data on 1510 consecutive total knee replacements (TKR) with navigation to demonstrate that the incidence of genu recurvatum is higher than what is cited in the literature. Methods. This is a retrospective review that was approved by our health science institutional review board. We reviewed resting, intra-operative alignment of 206 navigated total knee arthroplasty cases with recurvatum. This is data from 4 surgeons who are lower extremity joint replacement physicians. The range of motion (ROM) is measured and recorded by the attending physician during routine physical examination of the lower extremity. Demographic data was used to describe the patient group. The data will include pre-operative, intra-operative and post-operative ROM. The intra-operative data will be captured by the navigation system, this sytem is accurate to 1° and 1mm. The post-operative ROM will be obtained from an office visit. We are interested in the post-operative ROM to demonstrate correction of the recurvatum. Results. One thousand five hundred and ten primary TKR were reviewed for this study. Two hundred and six patients (13.6%) had genu recurvatum as measured by the navigation computer. The range of recurvatum was 0.5–30°; mean 5 degrees (STD 4.3°). Sixty six patients had >5 degrees of recurvatum (4.4%). Only 2 patients had recurvatum recorded on their pre-operative office visit. These 2 patients did not have extreme recurvatum, 3° and a few degrees on walking respectively. No patient had recurvatum at the 4 year visit (visit range 3 months – to 4 years). The primary diagnosis for the group was osteoarthritis, 92 %. All cases of recurvatum were treated with under resection of the femur and correction of the coronal plane. All cases were corrected intraoperatively. Conclusion. Etiology of recurvatum can be due to bony insufficiency at the anterior tibia, insufficiency at both femoral condyles or laxity of the posterior capsule and ligaments. During surgery this can be addressed by under resection of the femur and undersizing the femoral component to increase the flex space, or soft tissue tightening can be implemented. Our surgical technique aimed to balance hyperextension with reduction of the distal femoral cut. Coronal balance is also important in the management of hyperextension. Current total knee designs lack the extension cam effect and make sagital balancing critical. Recurvatum is difficult to correct after total knee arthroplasty and this issue is important to address at the time of primary surgery. The use of a navigation system helped us appreciate a deformity that is not easily detected during routine examination. This study found that genu recurvatum in patients receiving TKR is significantly higher than what is reported in the literature. This finding has important implications for the management of a small percentage but nonetheless significant number of patients. This deformity is not appreciated in the clinical setting during routine examination

There is a difference between “functional instability” of a total knee arthroplasty (TKA) and a case of “TKA instability”. For example a TKA with a peri-prosthetic fracture is unstable, but would not be considered a “case of instability”. The concept of “stability” for a TKA means that the reconstructed joint can maintain its structure and permit normal motion and activities under physiologic loads. The relationship between stability and alignment is that stability maintains alignment. Instability means that there are numerous alignments and almost always the worst one for the loading condition. In the native knee, “instability” is synonymous with ligament injury. If this were true in TKA, then it would be reasonable to treat every “unstable TKA” with a constrained implant. But that is NOT the case. If the key to successful revision of a problem TKA is understanding (and correcting) the specific cause of the problem, then deep understanding of why the TKA is unstable is essential. A case of true “instability” then, is the loss of structural integrity under load as the result of problems with soft tissue stabilizing structures and/or the size or position of components. It is rare that ligament injury alone is the sole cause of instability (valgus instability invariably involves valgus alignment; varus instability usually means some varus alignment and compromised lateral soft tissues). There will be forces (structures) that create instability and forces (structures) that stabilise. There are three categories of instability: Varus-valgus or coronal: Assuming that the skeleton, implant and fixation are intact. These are usually cases that involve ligament compromise, but the usual cause is CORONAL ALIGNMENT, and this must be corrected. The ligament problem is best solved with mechanical constraint. Gait disturbances that increase the functional alignment problems (hip abductor lurch causing a valgus moment at the knee, scoliosis) may require attention of additional compensation with re-alignment. Plane of motion: Both fixed flexion contractures and recurvatum may result in buckling. The first by exhaustion of the quadriceps (consider doing quadriceps “lunges” with every step) and the second because recurvatum is usually a compensation for extensor insufficiency. The prototype for understanding recurvatum has always been polio. This is perhaps one of the most difficult types of instability to treat. The glib answer has been a hinged prosthesis with an extensor stop but there are profound mechanical reasons why this is flawed thinking. The patient with recurvatum instability due to neurologic compromise of the extensor should be offered an arthrodesis, which they will likely decline. The simpler problem of recurvatum secondary to a patellectomy will benefit from an allograft reconstruction of the patella using a modified technique. A common occurrence is obesity with patellofemoral pain, that the patient has managed with a “patellar avoidance” or “hyperextension gait”. Plane of motion instability is a problem of the EXTENSOR MECHANISM DEFICIENCY. Flexion instability. This results from a flexion gap that is larger than the extension gap, where a polyethylene insert has been selected that permits full extension but leaves the flexion gap unstable. These patients achieve remarkable flexion easily and early, but have difficulties with pain and instability on stairs, with recurrent (non-bloody) effusions and peri-articular tenderness. Revision surgery is necessary. Flexion instability may also occur with posterior stabilised prostheses. So-called “mid-flexion” instability is a contentious concept, poorly understood and as yet, not a reported cause for revision surgery distinct from “FLEXION INSTABILITY”. Flexion instability is a problem of GAP BALANCE

Introduction. Genu recurvatum deformities are unusual before total knee arthroplasty (TKA), occurring in less than 1% of patients. The purpose of this study is to evaluate the clinical and radiographic results of primary TKA in patients that had recurvatum deformities before surgery. Patients and Methods. The inclusion criteria was to have recurvatum deformity over 10 degrees on lateral standing X-ray view. We retrospectively reviewed 22 knees with pre-operative recurvatum deformities, and the incident was 1.0% of all TKAs at our hospital. The etiology of the arthritis was osteoarthritis in 21 knees, of which 3 knees were neuropathic disease, and rheumatoid arthritis in 1 knee. There were 6 men and 16 women, and the average age was 73.3 years (range, 53 to 83 years) at the time of operation. The average follow-up period was 15 months (range, 3 to 81 months). We performed to use medial parapatellar approach and bone cutting was done by measured resection technique. The surgical knacks were resection of less distal femur and proximal tibia bone to make extension gap tightly, additionally decrease the tibial posterior slope. Posterior-stabilizer (PS) implants (NexGen LPS: Zimmer, Bisurface KU4+: JMM) were used in 20 knees and constrained implants (NexGen RH knee: Zimmer, Endo-Model Hinge Knee: Link) were in 2 knees with neuropathic joints. Results. The averaged Knee Society Knee and Function score improved from 33.1 points to 94.1 points, and 28.0 points to 60.5 points at the time of the last follow-up. The femorotibial angle changed from averaged 183.4 degrees (range, 162 to 195 degrees) preoperatively to averaged 173.3 degrees (range, 170 to 177 degrees). Preoperative hyperextension was averaged 18.2 degrees (range, 10 to 40 degrees). Intraoperatively, the hyperextension deformity was corrected in all cases. The tibial posterior slope was averaged 1.7 degrees (range, −2.7 to 6 degrees). The final hyperextension improved averaged 6.9 degrees (range, −1.7 to 26.6 degrees), all but one knee were corrected. One case treated with a standard PS type, who was associated with neuropathic disease, had a recurrence of recurvatum deformity and required revision surgery. Discussion. Recurvatum may be associated with a severe osseous deformity, capsular or ligamentous laxity, and neuromuscular disease. Surgical solutions may be to use a standard PS prosthesis with a slight underresection of the bone edge, and decrease tibial posterior slope. An alternative solution is to use a rotating-hinge prosthesis with less than antigravity quadriceps strength for neuromuscular disease

Introduction. The assessment of leg length is essential for planning the correction of deformities and for the compensation of length discrepancy, especially after hip or knee arthroplasty. CT scan measures the “anatomical” lengths but does not evaluate the “functional” length experienced by the patients in standing position. Functional length integrates frontal orientation, flexion or hyperextension. EOS system provides simultaneously AP and lateral measures in standing position and thus provides anatomical and functional evaluations of the lower limb lengths. The objective of this study was to measure 2D and 3D anatomical and functional lengths, to verify whether these measures are different and to evaluate the parameters significantly influencing these potential differences. Material and Methods. 70 patients without previous surgery of the lower limbs (140 lower extremities) were evaluated on EOS images obtained in bipodal standing position according to a previously described protocol. We used the following definitions:. anatomical femoral length between the center of the femoral head (A) and center of the trochlea (B). anatomical tibial length between the center tibial spine (intercondylar eminence) (C) and the center of the ankle joint (D). functional length is AD. global anatomical length is AB + CD. Other parameters measured are HKA, HKS, femoral and tibial mechanical angles (FMA, TMA), angles of flexion or hyperextension of the knee, femoral and tibial torsion, femoro-tibial torsion in the knee, and cumulative torsional index (CTI). All 2D et3D measures were evaluated and compared for their repeatability. Results. Regarding repeatability, an ICC> 0.95 was found for all measurements except for the tibial mechanical angle (0.91 for 2D, 3D 0.92 for 3D). We observed 54/140 lower limbs with Flessum/Recurvatum angles (FRA) >10°. 2D results (mean, SD) were. 41,8mm(2,9) for femoral anatomical length. 36,1mm(2,8) for tibial anatomical length. 78,0mm(5,4) for global anatomical length. 78,5 mm(5,5) for functional length. 7,4°(12,0) for Flessum/Recurvatum angle. −1,5°(6,4) for HKA. 4,9°(2,0) for HKS. 92,1°(3,4) for FMA. 87,1°(3,4) for TMA. 3D results (mean, SD) were. 42,4mm (2,8) for femoral anatomical length. 36,6mm (2,8) for tibial anatomical length. 79,0mm (5,4) for global anatomical length. 78,9mm (5,5) for functional length. 7,2°(12,0) for Flessum/Recurvatum angle. −1,0°(5,9) for HKA. 4,9°(1,5) for HKS. 92,7°(2,7) for FMA. 87,9°(3,9) for TMA. The 2D/3D measurements of functional lengths were statistically significant (p <0.0001. Student's test). For anatomical lengths. 2D/3D measurements were also statistically significant (p <0.0001. Student's test for femoral tibial and global anatomical lengths). Some parameters significantly influenced 2D/3D differences:. for the global anatomical length: FRA P<0,0001, TMA P=0,0173, HKA P=0,0259 and femoro-tibial torsion P=0,0026. for the functional length FRA P=0,0065. Discussion and conclusion. EOS imaging allows to accurately assess the anatomical and functional length experienced by the patient. These new data open new perspectives for planning length or axis corrections and for an optimized evaluation in some medico legal issues after joint replacement or posttraumatic sequelae. This study points out the importance of 3D measurements in outliers cases (varus or valgus cases, flessum or recurvatum of the knee)

Performing a total knee arthroplasty in a patient with a flexion contracture or recurvatum deformity requires from the surgeon an adequate knowledge of the principles of flexion – extension space balancing. In the standard TKA procedure, adequate balancing between the flexion and extension space is usually easily achieved, leading to an equal and symmetrical space both in flexion and extension, which results in a stable knee and maximal range of motion after implantation of the prosthetic components. The situation is different in the knee with a flexion contracture or recurvatum, where the extension space is relatively smaller (flexion contracture) or greater (recurvatum) than the flexion space. In both of these situations, the flexion and extension space should be balanced by the surgeon in order to avoid an important deficit in range of motion or an instability problem. Several surgical techniques are available for this. In the knee with a flexion contracture, the extension space is relatively too small. Adequate removal of posterior osteophytes will increase the extension space, and this should be the first step in the flexion – extension space procedure (1). Next, the collateral structures should be balanced, with release of the tight structures that are effective in extension only (2). These are predominantly the iliotibial band in the valgus knee, and the posterior oblique ligament in the varus knee. If these 2 steps are not sufficient, proximalisation of the femoral component by 2 to 3mm may be required (step 3), or a formal release of the posterior capsule from the posterior femoral condyles (4). When an anterior reference system is used, the surgeon can also decide to use a slightly larger femoral component with a slightly increased tibial resection to equalise the gaps (5). In the knee with a recurvatum deformity, the extension space is relatively too large. In this situation, distalisation of the femoral component by removing 2 mm less distal femoral bone, will decrease only the extension space without altering the flexion space (1). In case of anterior referencing, the use of a slightly undersized femoral component will further equalise the gaps (2). Just using a thicker tibial insert to fill up the extension space, while increasing the flexion space by resecting the PCL or increasing the tibial slope, may be another option in the modest recurvatum knee (3)

Introduction. To report our early experience and suitability over unicortical fixation system to reduce and hold the bone fragments in position during a CHAOS procedure of the femur or tibia during lower limb reconstruction surgery. Materials and Methods. We report a case series of the first consecutive 10 patients (11 bones) for which this CHAOS technique was used between May 2017 and October 2019 by the same surgeon. The novel aspect of the procedure was the use of a unicortical device, Galaxy UNYCO (Orthofix, Verona, Italy), which eliminate the need for any change of fixation during the procedure. It also means the intramedullary canal was left free for the intramedullary nailing. Results. We treated 4 femurs and 7 tibias with this technique without any loss or failure of the construct. We treated uniplanar and multiplanar deformities with the angulations between 8 degrees of valgus to 15 degrees of varus and from 0 to 8 mm translation in the AP view, from 20 degrees procurvatum to 15 degrees recurvatum and 0 to 2 mm translation on the lateral view and from 20 degrees internal rotation to 5 degrees external rotation and 0 to 10 mm translation on axial view. Conclusions. The construct was able to deal with the total tension in the system both in the correction phase and the additional stress applied during insertion of a nail such as reaming and impacting the nail to the canal. The potential advantage also included the possibility of intramedullary nailing without interference with the external fixation device

Total knee arthroplasty is well documented to be a very successful operation, proper alignment and soft tissue balancing is important. Computer navigation for TKA has been available for more than 10 years. This paper reviews our outcomes and the lessons learned from CAS. October 1, 2001 we preformed the first clinical case of a navigated TKA in North America. We tracked our early results at with 1 year of follow up of 150 navigated knee cases and compared there data to 50 non- navigated knees. Long standing lower extremity x-rays were measured to determine mechanical alignment. In 2011 we reviewed all cases to date to determine if there were pin site problems. In 2012 we looked at are recurvatum data. Oct 2011 was our 10. th. year using the computer navigation system for TKA. We reviewed what we have learned and assess our outcome data on patients who were at least 9.5 years post surgery. All patients received long standing lower extremity x-rays pre-operatively and at 10 year follow up. Any problems or revisions were noted. Our early results will be compared to our 10 year results. Our 1 year results showed no difference in clinical outcome or range of motion compared to the non-navigated group. The navigated knee group had better alignment; 52% were in neutral alignment, vs. 23% in the non-navigated group. Overall the navigated group, 80% of all alignment was within 1.5 degrees of neutral while the non-navigated groups 80 % of cases were between 5° valgus and 4° varus. Our data for 10 year follow up (range 9.5–10.5 years) is the similar to our early results. We have seen 42 patients, 44 knees. The alignment from long standing lower extremity x-rays, 53% were neutral or +/− 1°. Twenty eight knees of 43 were +/− 3°. There were 3 revisions in this small group. One was revised for a loose tibial base plate with osteolysis on the tibia and femur. The revision was 10 years after the index surgery. There were 2 other revisions, both for infection, were treated with a poly exchange and wash out. To date we have done 2030 navigated knee cases and our data shows that 13.9% demonstrate genu recurvatum. The range was 0.5° to 30°, 104 patients, 5.1% had more than 5° recurvatum. In the literature recurvatum rates are reported at about 1%. After reviewing all case to date in we did not observe any pin site problems. CAS is still the main objective measure we have in the operating room to date. The advantages of CAS are it provides real time assessment of the true varus/valgus deformity, initial extension and medial/lateral soft tissue imbalance and anticipates final trial reduction. We are performing less soft tissue releases most likely because our tibia and femoral cuts are more precise. Our 10 year follow up data while encouraging requires more investigation

Objective: To study deformities in tibial fractures that are treated orthopedically. Material and Methods: A prospective study of 42 tibial fractures treated orthopedically (1996–2003), Average age was 8.9 years, Nineteen (45.2%) were male and 23 (54.3%) were female. Average follow-up was 59.6 months. Nineteen of the fractures (45.2%) were medial third and 23 (54.8%) were distal. The fracture line was spiral in 26 cases (61.9%), oblique in 10 cases (23.8%) and transverse in 6 (4.8%). In 18 cases (42.9%), there was a facture of the fibula and in 24 cases there was not (57.1%). Exclusion criteria: previous fractures, angular deformities less than 5 and surgical treatment. At one year post-concolidation, antero-posterior and lateral X-rays were taken and if the angular deformity was greater than 5 a tibial CT was done to measure axial rotation. Descriptive statistical and non-parametrical studies was done with signification p < 0.05. Results: Varus deformity was 5.8, valgus 6, recurvatum 6.5 and antecurvatum 4, In 23 cases (54.8%), an association varus and recurvatum was found, in 9 cases (21.4%) valgus- recurvatum were associated, and in five cases each there was varus- and valgus- antecurvatum associations (11.9%). Healthy tibia had an external rotation of 38.2, while the rotation of fractured tibia was virtually the same at 38.5. In fractures of the medial third, external rotation decreased 8.3(55.6% cases). When the fibula was intact, external rotation was 6.4(40%) and decreased 8.7 (17.5%). When was fractured, decreased 6.5(30% cases). Localization and fracture line had no impact on results. external tibial rotation was greater for intact fibula than for fractured ones (p= 0.03). Conclusions: 1) The majority of tibias treated orthopedically consolidated in varus or valgus-antecurvatum, 2) When there was a lesion of the fibula, the consolidation of the external rotation of the tibia increased, when there was no lesion to the fibula, it decreased

Background. A grossly deformed knee is believed to be an indication for PS -TKA. However, the role CR-TKA in such knees is unclear in the literature. Considering the obvious advantages of CR, we analysed the mid term follow up of CR knees in gross deformities. Materials and Methods. 1590 patients (1740 knees) underwent TKA between January 2011 to December 2012, out of which 570 knees had gross deformity (varus > 15°, FFD > 10°, valgus > 10°, recurvatum > 10). CR-TKA was performed for 540 knees and were included in our study. Subvastus approach was used for all knees. Average age being 68 years, mean BMI being 32 and average weight 70 kgs. Intraoperatively, POLO test was used to ensure PCL stability, further confirmed by direct palpation. Femoral roll-back was found adequate. Results. 95% of grossly deformed knees underwent CR-TKA. Mean pre-operative knee score was 45 which improved to 94 at mid-term follow-up at 18 to 36 months. There were no incidence of component loosening or instability. Three knees needed secondary resurfacing of patella. One knee got infected for which components were explanted and joint debrided thoroughly. Lateral radiographs showed consistent roll-back in all except for 3 knees which had femoral roll-forward. Discussion. PS-TKA have shown to yeild good results in gross deformities, however the role of CR had been unclear. Contrary to popular belief, in our opinion, greater the deformity, greater is the need to retain the PCL. Balancing the flexion extention space is easier and involves lesser resection of distal femur. Hence, its bone preserving. For valgus knees, PCL acts a medial stabilizer. In recurvatum deformity, the posterior capsule being stretched out, retaining PCL has prime importance. Our retrospective mid term follow up have shown good results. However, long term analysis is necessary to highlight the survivorship. Conclusion. CR-TKA must be considered for knees with gross deformity for its aforementioned advantages

Purpose: Retrograde nailing is emerging among methods proposed or stabilisation of femoral fractures above total knee arthroplasties (TKA). Material and methods. Between June 1994 and may 2000, 12 fractures above TKA were treated by retrograde nailing. These fractures occurred 43 months (4–51) after implantation of the TKA in three men and women aged 74 years (43–88). The fracture was situated just above the prosthetic trochlea in ten, and distant from the implant in two. The posterior cruciate ligament was preserved in six TKA and six were posterior stabilised prostheses. Indications for arthroplasty were degenerative joint disease in nine and rheumatoid polyarthritis in three. Four patients had proximal implants (one fixation and three prostheses). A percutaneous approach was used except for three cases in order protect the tibial component. Closed reduction was achieved, but required an open reduction for completion in two cases. the nail was advanced just to the trochlea in patients with a preserved posterior cruciate ligament and beyond the posterior stabilisation cage for the posterior stabilised implants. The knee was mobilised immediately after surgery and total weight-bearing was encouraged four to six weeks later. Results: There was one error in the proximal aiming, one metastatic infection from a leg ulcer at three months and one tibial loosening in a polyarthritic woman 66 months after arthroplasty, i.e. 51 months after the fracture. Bone healing was achieved at two to four months. Frontal deviation was less than 5°. Recurvatum was less than 5° in eight cases, between 5° and 10° in two cases and between 10° and 20° in two others. At mean follow-up of 23 months (3–60), maximal moss of mobility was 10°. There was not worsening of pain. Discussion: Retrograde nailing leads to bone healing with satisfactory frontal alignment and minimal loss of mobility. The approach uses the initial incision, facilitating complementary procedures or revision if needed. The main problem is controlling recurvatum, even though at the follow-up reported there was no clinical impact or loosening. The limitations of this method are well defined: free medullary canal, sufficient knee flexion, compatible femoral component. The tibial obstacle in posterior stabilised implants is less well known; It should be protected during the nailing if it is high. The polyethylene insert may have to be removed temporarily in certain cases. Conclusion: The two principal problems with retrograde nailing are recognising implants compatible with this technique and controlling recurvatum. Results are acceptable with a minimally invasive technique

The advent of Elastic Stable Intramedullary Nailing has revolutionised the conservative treatment of long human bone fractures in children (Metaizeau, 1988; Metaizeau et al., 2004). Unfortunately, failures still occur due to excessive bending and fatigue (Linhart et al., 1999; Lascombes et al., 2006), bone refracture or nail failure (Bråten et al., 1993; Weinberg et al., 2003). Ideally, during surgery, nail insertion into the diaphyseal medullary canal should not interrupt or injure cartilage growth; nails should provide an improved rigidity and fracture stabilisation. This study aims at comparing deflections and stiffnesses of nail-bone assemblies: standard cylindrically-shaped nails (MI) vs. new cylindrical nails (MII) with a flattened face across the entire length allowing more inertia and a curved tip allowing better penetration into the cancellous bone of the metaphysis (Figure 1). MII exhibits a section with two parameters: a diameter C providing nail stiffness and a height C' providing practical dimension when both nails are crossed at the isthmus of the diaphysis: C/C' is set to 1.25 for all MII nails. A CT scan of a patient aged 22 years was used to segment a 3D model of a 471mm-long right femur model. The medullary canal diameters at the isthmus are 10.8mm and 11.4mm in the ML and AP direction, respectively. Titanium-made CAD models of MI (Ø=4mm) and MII (flat face: Ø=5mm) were pre-curved to maintain their flat face and carefully placed and positioned according to surgeon's instructions. Both nails were inserted via lateral holes in the distal femur with their extremities either bumping against the cortex or lying in the trabecular bone. Transverse and comminuted fractures were simulated (Figure 1). For each assembly, a Finite Element (FE) tetrahedral mesh was generated (∼100181 nodes and 424398 elements). Grey-scale levels were used to assign heterogeneous material properties to the bone (E=6850 ρ. 1.49. (Morgan et al., 2003)). Two modes of loading were considered: 4-point bending (varus and recurvatum: F. max. =6000N) and internal torsion (M. max. =70kNmm). This led to the simulation of 15 FE models, including a reference intact femur. Results show that in valgus, for the transverse (comminuted) fracture, the mean displacement of the assembly decreased by around 50%: from 15.24mm (27.49mm) to 8.15mm (13.85mm) for MI and MII, respectively, compared to 3.59mm for the intact bone. The assembly stiffness increased by 87% and 99% for transverse and comminuted fracture, respectively (Table 1). Similar trends were found in recurvatum with higher increases in assembly stiffness of 170% and 143% for transverse and comminuted fracture, respectively (Table 1). In torsion, for the transverse (comminuted) fracture, the measured angle of rotation decreased from: 0.43rad (0.66rad) to 0.22rad (0.43rad) for MI and MII, respectively, compared to 0.09rad for the intact bone. This corresponded to an increase of 95% and 55% in assembly stiffness for transverse and comminuted fracture, respectively. In conclusion, using the 5mm-diameter new nails (MII) for the same intramedullar space, during either bending or torsion, assemblies were always stiffer than when using standard cylindrical nails

Ollier’s disease is characterised by severe deformity of the extremities and retarded growth because of multiple enchondromas. For correction of deformity, the Ilizarov method has been used although it has many complications. A 17-year-old boy with Ollier’s disease had a limb-length discrepancy of 17.4 cm, with a valgus deformity of the right knee and recurvatum of the femur of 23°. He had undergone three unsuccessful attempts to correct the deformities by using external fixators. We used a fully implantable, motorised, lengthening and correction nail (Fitbone) to achieve full correction of all the deformities without complications. We decided to carry out the procedure in three stages. First, we lengthened the femur by 3.6 cm and the tibia by 4 cm. We then exchanged the femoral nail for a longer implant and achieved a further 6 cm of length. This reduced the shortening to 3.8 cm. When the boy has finished secondary school we will adjust the remaining discrepancy