[Osteotomies around the Knee]. / Kniegelenknahe Korrekturosteotomien.

Osteotomies around the knee in unicompartimental osteoarthritis had an impressing revival in the past few years and have to be kept in mind as an alternative to total knee arthroplasty. The most frequent type of osteotomies around the knee is the medial open wedge high tibia osteotomy (MOWHTO). But still also closed wedge high tibia osteotomies (CWHTO) have their relevance in many cases. Distal femur osteotomies (DFO) are used more and more frequently in most cases as closed wedge, the open wedge DFO shows more problems in bone healing. All osteotomies with isolated correction in frontal plane should be done with a biplanar bonecut. In cases of severe varus and valgus malalignment a double-level osteotomy (combined femoral and tibial osteotomy) has to be executed. Severity and frequency of adverse events in osteotomies around the knee are mostly comparable to those in arthroplasty, except non-union which is only related to osteotomies and more often seen in smokers. There are nearly no age limits for osteotomies around the knee. Ten years-survival in HTOs are about 85 to 91% according to literature.

Advances in modern osteotomies around the knee : Report on the Association of Sports Traumatology, Arthroscopy, Orthopaedic surgery, Rehabilitation (ASTAOR) Moscow International Osteotomy Congress 2017.

Corrective lower limb osteotomies are innovative and efficient therapeutic procedures for restoring axial alignment and managing unicompartmental knee osteoarthritis. This review presents critical insights into the up-dated clinical knowledge on osteotomies for complex posttraumatic or congenital lower limb deformities with a focus on high tibial osteotomies, including a comprehensive overview of basic principles of osteotomy planning, biomechanical considerations of different implants for osteotomies and insights in specific bone deformity correction techniques. Emphasis is placed on complex cases of lower limb osteotomies associated with ligament and multiaxial instability including pediatric cases, computer-assisted navigation, external fixation for long bone deformity correction and return to sport after such osteotomies. Altogether, these advances in the experimental and clinical knowledge of complex lower limb osteotomies allow generating improved, adapted therapeutic regimens to treat congenital and acquired lower limb deformities.

Does obesity and nicotine abuse influence the outcome and complication rate after open-wedge high tibial osteotomy? A retrospective evaluation of five hundred and thirty three patients.

PURPOSE: Nicotine abuse and obesity are well-known factors leading to common post-operative complications. However, their influence on the outcome after high tibial osteotomy is controversial. Thus, the aim of this study was to evaluate their effect on the clinical outcome with particular regard to bone non-union and local complications. METHODS: The functional outcome after open-wedge high tibial osteotomy using the TomoFix® plate was assessed by means of the 12-item Oxford knee score in a multicentre study. In addition the intra- and post-operative complications were determined. RESULTS: Of 533 eligible patients, 386 were interviewed after a mean follow-up of 3.6 years. The median Oxford knee score was 43 points (max. 48 points). Six per cent of these patients experienced at least one local post-operative complication. Patients with a body mass index (BMI) of up to 25 and between 25 and 30 had a higher mean score by 3.5 and 1.8 points, respectively, compared with those having a BMI of more than 30 showing a score of 37.5. No correlation was observed between smoking and the functional outcome. Smoking habits, BMI, the absolute patient weight and the interaction term between smoking and BMI were not significant with reference to the complication rate. CONCLUSIONS: This study reveals favourable mid-term results after high tibial osteotomy in varus osteoarthritis even in patients who smoked and obese patients. The indication in patients with a BMI above 30 should be handled with care due to the slightly inferior outcome, although the complication rate was not increased in these patients.

Outcome after high tibial open-wedge osteotomy: a retrospective evaluation of 533 patients.

PURPOSE: Open-wedge valgus high tibial osteotomy is a well-established procedure in the management of medial osteoarthritis of the knee. In recent years, improved osteotomy and fixation methods have led to an increased use of this technique. The aim of this study was to identify predictive parameters for the clinical outcome after valgus high tibial osteotomy. METHODS: A multicentre case series involving retrospective capture of baseline data and prospective outcome assessment of patients with knee OA who underwent an osteotomy using Tomofix(®) plate was conducted. Functional outcome was assessed using Oxford 12-item Knee Score. RESULTS: Before surgery, the majority of patients had grade III (52%) and grade IV (33%) lesions according to Outerbridge classification. Three hundred and eighty-six of 533 eligible patients were interviewed for follow-up after an average of 3.6 years. The mean Oxford Knee Score was 43 points. Six per cent experienced at least one local postoperative complication. There was a tendency towards lower score results in patients with a higher preoperative degree of the medial cartilage lesion. No correlation between patient age and the Oxford Knee Score was observed. CONCLUSION: Being male, being operated by an experienced surgeon, having no intake of pain medication at follow-up and having no postoperative complication are positive predictors of the Oxford Knee Score up to 5 years after surgery. This study reveals favourable midterm results after valgus high tibial osteotomy in varus osteoarthritis, even in older patients with high degree of cartilage damage. LEVEL OF EVIDENCE: II.

[The medial closed-wedge osteotomy of the distal femur for the treatment of unicompartmental lateral osteoarthritis of the knee]. / Die varisierende Closed-Wedge-Osteotomie am distalen Femur zur Behandlung der unikompartimentalen lateralen Arthrose am Kniegelenk.

OBJECTIVE: Shifting of the mechanical axis from the lateral to the medial compartment in patients with lateral osteoarthritis in combination with valgus deformity. INDICATIONS: Osteoarthritis of the lateral compartment in combination with valgus deformity of the (distal) femur. Posttraumatic and congenital valgus deformities of the (distal) femur. CONTRAINDICATIONS: Osteoarthritis of the medial compartment (>or=grade 3 on Outerbridge Scale). Total loss of the medial meniscus. Acute or chronic infections. Rheumatoid arthritis. Heavy smoking. Extension or flexion deficit>20 degrees. Poor soft-tissue conditions on site of surgery. SURGICAL TECHNIQUE: Optional: arthroscopy before osteotomy. Anteromedial skin incision, subvastus approach with blunt preparation around the vastus medialis muscle and separation of this muscle from the intermuscular septum. The posterior osteotomy is marked with Kirschner wires (OGD [osteotomy guiding device], Synthes, Switzerland, can be used optionally). The biplanar cut is marked on the bone with an electrocautery device. The bone cuts start with the posterior incomplete osteotomy, followed by the anterior biplanar cut. After finishing the osteotomy (three bone cuts!), the bone wedge can be removed. Closing the osteotomy should start very gently as a plastic deformation of the bone. A radiologic control of the leg alignment and the mechanical axis is achieved with an alignment rod (Synthes, Switzerland). The plate should be inserted under the vastus medialis muscle. It is very important, that the surgeon controls the correct anteromedial position of the plate at the distal femur (right and left version of the implant). Fixation of the plate with locking screws distally. Positioning of a lag screw in the dynamic hole directly above the osteotomy. Insertion of monocortical screws in the three remaining holes proximal of the lag screw. Finally, the lag screw is changed to a self-tapping bicortical locking head screw. X-ray control, wound closure. POSTOPERATIVE MANAGEMENT: Elastic bandage of the leg up to the thigh in the operating room. Change of the dressing on day 1 after surgery. Ice treatment. Walking on crutches starting day 1 after surgery. Physiotherapy and manual lymph drainage starting on day 1 after surgery. Partial weight bearing for the first 4-6 weeks after surgery. Suture removal after 10-12 days. X-ray control on day 3 and 6 weeks after surgery. Discharge possible, if wounds are dry (day 4-7). RESULTS: Between January 2005 and October 2008, 60 patients were treated with medial closed-wedge osteotomy of the distal femur (since 11/2006 only with biplanar osteotomy technique) at the Department of Trauma and Reconstructive Surgery, Diakoniekrankenhaus Henriettenstiftung Hannover, Germany. The average wedge size was 7.6 mm (4-13 mm). The mean age was 39.7 years (17-79 years). The patients had had 2.3 previous surgeries. The mean follow- up was 21 months (3-45 months). Freiling D, et al. Biplanare Osteotomie bei unikompartimentaler lateraler Kniegelenkarthrose Flexion was 126 degrees (95-140 degrees) preoperatively, and 128 degrees (105-140 degrees) postoperatively. 25 patients had at least 5 degrees extension deficit (5-15 degrees) before surgery, whereas ten patient did not reach the full extension at follow-up examination. The Tegner Activity Score increased from 2.8 (1-4) preoperatively to 5.6 (2-9) postoperatively, in IKDC (International Knee Documentation Committee) Score, 18 patients reached grade A, 27 grade B, nine grade C, and six grade D. The visual analog scale (VAS) score decreased from 6.8 (8-2) preoperatively to 3.1 (0-7) postoperatively. Seven patients had revision surgery (three times delayed union/nonunion of the osteotomy, one superficial and one deep infection, one hematoma, one fracture [proximal of the internal plate fixator] after a fall).

Evolution of open-wedge high-tibial osteotomy: experience with a special angular stable device for internal fixation without interposition material.

Surgical correction of bowed legs should be performed as early as possible. Overload osteoarthritis, even without significant varus deformity of the knee, is a further indication for open-wedge high-tibial osteotomy. Progression of damage to the joint surfaces due to overloading can be significantly retarded by realigning the extremity with the aim to, at least, reduce overload on the medial compartment to a value close to physiological. Significant improvement to open-wedge high-tibial osteotomy (OWHTO) has been made on two fronts: (a) by the use of a more appropriate surgical technique and (b) by promoting osteogenesis through an angular-stable fixation device with just the correct amount of elasticity. A retrospective study of 53 consecutive cases in which no interposition material was used to fill the wedge, with gap openings between 5 mm and 20 mm, showed that ossification of the gap always progressed from the lateral hinge towards the medial side. Standard radiographs showed 75% of the gap filled in with new bone within 6-18 months. In conclusion, we believe that open-wedge high-tibial osteotomy using the TomoFix plate has proved to be successful in treating unicompartmental gonarthrosis, even without bone grafts or bone-substitute material.

A fluoroscopy-based surgical navigation system for high tibial osteotomy.

High tibial osteotomy is a widely accepted treatment for unicompartmental osteoarthritis of the knee and other lower extremity deformities, particularly in young and active patients. However, it is generally recognized as a technically demanding procedure. The lack of intraoperative control of the mechanical axis of the affected limb often results in postoperative malalignments, which is one of the main reasons for poor long-term results. Moreover, inaccurate osteotomies, such as insufficient or excessive bone cut, or incorrect orientation of the chisel or saw blade, have been observed. A computer assisted intraoperative planning and navigation system is therefore proposed in order to address these technical problems. During operation, fluoroscopic images are acquired and anatomical landmarks are digitized; a patient-specific coordinate system is established accordingly. After the three-dimensional measurement of the deformity and interactive planning of the osteotomy plane, the deformity is corrected under navigational guidance. The proposed system has been successfully introduced into the clinical practice of surgery after encouraging laboratory evaluations, with results affirming that it is safe and accurate.

Implementation, accuracy evaluation, and preliminary clinical trial of a CT-free navigation system for high tibial opening wedge osteotomy.

OBJECTIVE: The objectives of this study are to design and evaluate a CT-free intra-operative planning and navigation system for high tibial opening wedge osteotomy. This is a widely accepted treatment for medial compartment osteoarthritis and other lower extremity deformities, particularly in young and active patients for whom total knee replacement is not advised. However, it is a technically demanding procedure. Conventional preoperative planning and surgical techniques have so far been inaccurate, and often resulting in postoperative malalignment representing either under- or over-correction, which is the main reason for poor long-term results. In addition, conventional techniques have the potential to damage the lateral hinge cortex and tibial neurovascular structures, which may cause fixation failure, loss of correction, or peroneal nerve paralysis. All these common problems can be addressed by the use of a surgical navigation system. MATERIALS AND METHODS: Surgical instruments are tracked optically with the SurgiGATE((R)) navigation system (PRAXIM MediVision, La Tronche, France). Following exposure, dynamical reference bases are attached to the femur, tibia, and proximal fragment of the tibia. A patient-specific coordinate system is then established, on the basis of registered anatomical landmarks. After intra-operative deformity measurement and correction planning, the osteotomy is performed under navigational guidance. The deformities are corrected by realigning the mechanical axis of the affected limb from the diseased medial compartment to the healthy lateral side. The wedge size, joint line orientation, and tibial plateau slope are monitored during correction. Besides correcting uni-planar varus deformities, the system provides the functionality to correct complex multi-planar deformities with a single cut. Furthermore, with on-the-fly visualization of surgical instruments on multiple fluoroscopic images, penetration of the hinge cortex and damage to the neurovascular structures due to an inappropriate osteotomy can be avoided. RESULTS: The laboratory evaluation with a plastic bone model (Synbone AG, Davos, Switzerland) shows that the error of deformity correction is <1.7 degrees (95% confidence interval) in the frontal plane and <2.3 degrees (95% confidence interval) in the sagittal plane. The preliminary clinical trial confirms these results. CONCLUSION: A novel CT-free navigation system for high tibial osteotomy has been developed and evaluated, which holds the promise of improved accuracy, reliability, and safety of this procedure.

Computer aided ACL reconstruction.

The following article gives a clinical description of computer aided ACL reconstruction using the Praxim Medivision tool. The special feature of this navigation is the existence of the possibility to virtually graft the implantation without first having to attach anchoring channels, which allows potential risks to be recognized and thus avoided. This description meets with the current operating techniques of the 4-fold semitendinosus technique, and of extra-cortical anchoring with the endobutton/suture disc technique.

TomoFix: a new LCP-concept for open wedge osteotomy of the medial proximal tibia--early results in 92 cases.

High Tibial Osteotomy (HTO) is an established treatment for unicompartmental osteoarthritis of the knee with malalignment. The classic procedure for correcting varus deformity is the lateral closed wedge osteotomy of the tibia with osteotomy of the fibula. The disadvantages of this technique are well known. Open wedge osteotomy from the medial side eliminates the risk of compartment syndrome and peroneal nerve injuries. A new fixation device (TomoFix) with an adapted surgical technique allows stable fixation of the osteotomy without the need to fill the osteotomy gap with bone grafts. In a prospective study, 92 consecutive cases were treated with this procedure. Bony healing with remodelling of the medial and posterior cortical bone was observed. Full weight-bearing was possible ten weeks after surgery. There were no implant failures. Complications included one delayed union, two revarisations and one deep infection.