Tibial and femoral osteotomies in varus deformities - radiological and clinical outcome.

BACKGROUND: Varus deformities of the knee are frequently corrected by osteotomies, which should be performed at the level of origin. But in contrast to high tibial osteotomies (HTO), little data exists for distal femoral osteotomies (DFO). This study evaluates radiological and clinical outcomes after valgisation osteotomies in the proximal tibia and distal femur. METHODS: We used an observational cohort study design and prospectively performed preoperative long standing radiographs (LSR), lateral x-rays and clinical questionnaires (SF-36, Lysholm score, VAS). Postoperative LSR and lateral x-rays were obtained on average 18 months postoperative and postoperative clinical questionnaires at final visit (mean follow up 46 months). A subgroup analysis of the different surgical techniques (oHTO vs. cDFO) was performed, with regards to radiological and clinical outcomes. RESULTS: Finally 28 osteotomies with medial tibial opening (oHTO) or lateral femoral closing (cDFO) wedge osteotomies in 25 consecutive patients (mean age 40 years) were identified. There were 17 tibal and 11 femoral procedures. All osteotomies were performed at the origin of deformity, which was of different etiology. The average deviation of the final HKA compared to the preoperative planning was 2.4° ± 0.4°. Overall, there was a significant improvement in all clinical scores (SF-36: 61.8 to 79.4, p < 0.001; Lysholm-score: 72.7 to 90.4, p < 0.001; VAS: 3 to 1, p < 0.001). There was no significant correlation between surgical accuracy and outcome scores. CONCLUSION: Valgisation osteotomies lead to a significant improvement in all clinical scores with the demonstrated treatment protocol. An appreciable proportion of varus deformities are of femoral origin. Since cDFO provides comparable radiological and clinical results as oHTO, this is an important treatment option for varus deformities of femoral origin.

[Prophylactic fasciotomy in tibial osteotomies: functional results]. / Prophylaktische Fasziotomie bei Tibia-Osteotomien: funktionelle Ergebnisse.

BACKGROUND: Intramedullary nailing in tibial osteotomy (TO) can be combined with minimally invasive prophylactic fasciotomy (PF) of the anterior compartment of the lower leg to prevent postoperative acute compartment syndrome (CS). So far no studies are available on the effects of TO or PF on specific functions of the extensor muscles. OBJECTIVE: To investigate the medium-term outcome after PF in TO in patients without preoperative functional impairment. MATERIAL AND METHODS: In 41 cases (28 women, 13 men) the patients were questioned with respect to clinical function on average 6.1 years after elective TO and PF fixed with intramedullary nails. Of the cases 23 were examined measuring isometric strength and range of motion (ROM) of dorsiflexion (DF) of the foot. Strength was compared to the 10% standard percentile to test for clinical relevance and to the contralateral side if applicable. RESULTS: In an average of 86% of the cases no or minor functional impairment of the extensors was reported. The DF of the foot was rated as the leading impairment. Mean strength did not differ significantly from the gender-specific 10% standard percentiles but was significantly lower on the operated side with 16.0 ± 6.5 kgf compared to the healthy side with 17.5 ± 6.3 kgf (p < 0.01). Subjective impairments of DF of the foot correlated clearly negatively with ROM (rs = -0.46, p < 0.05) but not with strength. CONCLUSION: The results indicate a low occurrence of subjectively relevant functional impairment of the extensor muscles. The decrease of strength was not found to be clinically relevant. Subjective impairments appeared to be caused by a decrease of ROM, not strength.

Intraoperative alignment correlates well with long standing radiographs - The X-ray grid method in complex knee surgery.

OBJECTIVE: While long standing radiographs (LSR) represent the gold standard for preoperative alignment assessment and planning of lower limb deformity corrections, there is no consensus about the intraoperative alignment assesments (IAC) due to various limitations of the common methods. The present study introduces a radiolucent X-ray grid with integrated radiopaque lines explicitly designed for fluoroscopic IAC and evaluates its reliability in comparsion to the LSR. METHODS: Patients with posttaumatic and congenital lower limb deformity surgery and preoperative LSR as well as fluoroscopic IAC utilizing the X-ray grid were retrospectively included to the study. The mechanical axis deviation (MAD) in percentage of the maximum tibial width from the medial to the lateral in comparison between the image pairs was set as primary outcome parameter. Multiple rater and measurements determined intra- and interobserver reliabilit of both imaging methods. In addition, the effects of age, gender, body mass index (BMI), etiology, joint line convergence angle (JLCA), and extent varus or valgus deformity were analysed. RESULTS: A total of 84 patients were finally included. The mean absolute difference of MAD between the two techniques was 7.2 ± 0.8%. MAD between the LSR and IAC correlated at a high level (R = 0.96, p <0.001). The agreement decreased with increasing extent of deformity (p <0.01) and with higher deviation of JLCA between LSR and IAC (p <0.01). Intra- and interobserver concordance correlation coefficient (CCC) for MAD measurements were 0.99 for both imaging techniques. CONCLUSION: Fluoroscopy combined with the X-ray grid method is a valid tool for intraoperative assessment of lower limb alignment in deformity correction surgery, and the correlation between LSR and IAC is better than in other similar techniques described in the literature. However, in case of severe coronal alignment deformity and highly divergent JLCA, the agreement between both imaging techniques decreases significantly.

Bowlegs and Intensive Football Training in Children and Adolescents.

BACKGROUND: In many countries around the world, football (association football, or "soccer" predominantly in North America) is the sport most commonly played by children and adolescents. It is widely thought that football players are more likely to develop genu varum (bowlegs); an association with knee arthritis also seems likely. The goals of this systematic review and meta-analysis are to provide an overview of the available evidence on genu varum after intensive soccer training in childhood and adolescence, and to discuss the possible pathogenetic mechanisms. METHODS: We systematically searched the PubMed, Medline, Embase, and Coch- rane Library databases for studies of the relation between leg axis development and intensive football playing during the growing years. RESULTS: Controlled studies employing the intercondylar distance (ICD) as the target variable were evaluated in a meta-analysis, with the mean difference as a measure of effect strength. This meta-analysis included 3 studies with a total of 1344 football players and 1277 control individuals. All three studies individually showed a signifi- cant difference in the mean ICD values of the two groups. The pooled effect esti- mator for the mean difference was 1.50 cm (95% confidence interval [0.53; 2.46]). Two further studies that could not be included in the meta-analysis had similar con- clusions. Asymmetrical, varus muscle forces and predominantly varus stress on the osseous growth plates neighboring the knee joint, especially during the prepubertal growth spurt, seem to be the cause of this phenomenon. CONCLUSION: Intensive soccer playing during the growing years can promote the devel- opment of bowlegs (genu varum) and, in turn, increase the risk of knee arthritis. Phy- sicians should inform young athletes and their parents of this if asked to advise about the choice of soccer as a sport for intensive training. It cannot be concluded, however, that football predisposes to bowlegs when played merely as a leisure activity.

Limb lengthening with fully implantable magnetically actuated mechanical nails (PHENIX(®))-preliminary results.

Limb lengthening and deformity correction with fully implantable systems is becoming more and more widespread. Different actuation techniques are known and every system has its specific limitations in distraction control and/or stability. A new system with magnetic actuation offers outstanding options. The mechanism of the Phenix M2(®) bone lengthening nail (Phenix Medical, France) is driven by a strong external magnet. The device can provide lengthening, shortening and bone transport. Between December 2011 and November 2012 we applied the nail in 10 patients with an average age of 25 years (range 15-40 years). There were 6 femoral and 4 tibial procedures. The intended distraction goal was achieved in 8 of 10 patients. In three cases we simultaneously corrected malalignment. Average lengthening was 4.6 cm (range 1.3-7.6 cm). Average distraction index was 0.85 mm/day (range 0.6-1.3mm/day). Average weight bearing index was 27 days/cm (range 16-37 days/cm). Three patients had revisions due to early distraction arrest. The early results are comparable to those of other intramedullary systems in the literature like the ISKD(®), the Albizzia(®) or the Fitbone(®) system. All intramedullary procedures require accurate analysis and planning, advanced operative technique and close follow-up. The custom made design of the Phenix nail with unique options for size, stroke and locking provides new options for small bones and improved stability. The shortening option may be helpful for soft tissue problems, joint subluxation and additional stimulation of bone formation. Magnetic forces have to be considered and too much soft tissue around the nail might be a limiting factor. The magnetically actuated Phenix nail offers new therapeutic options in limb lengthening.

Radiation-free drill guidance in interlocking of intramedullary nails.

Intramedullary nailing is a technically demanding procedure which involves an excessive amount of x-ray acquisitions; one study lists as many as 48 to successfully complete the procedure. In this work, a novel low cost radiation-free drilling guide is designed to assist surgeons in completing the distal locking procedure without any x-ray acquisitions. Using an augmented reality fluoroscope that coregisters optical and x-ray images, we exploit solely the optical images to detect the drilling guide in order to estimate the tip position in real-time in x-ray. We tested over 200 random drill guide poses showing a mean tip-estimation error of 1.72 +/- 0.7mm which is significantly robust and accurate for the interlocking. In a preclinical study on dry bone phantom, three expert surgeons successfully completed the interlocking 56 out of 60 trials with no x-ray acquisition for guidance and an average time of 2 min.

Intra-op measurement of the mechanical axis deviation: an evaluation study on 19 human cadaver legs.

The alignment of the lower limb in high tibial osteotomy (HTO) or total knee arthroplasty (TKA) must be determined intraoperatively. One way to do so is to deform the mechanical axis deviation (MAD), for which a tolerance measurement of 10 mm is widely accepted. Many techniques are proposed in clinical practice such as visual inspection, cable method, grid with lead impregnated reference lines, or more recently, navigation systems. Each has their disadvantages including reliability of the MAD measurement, excess radiation, prolonged operation time, complicated setup and high cost. To alleviate such shortcomings, we propose a novel clinical protocol that allows quick and accurate intraoperative calculation of MAD. This is achieved by an X-ray stitching method requiring only three X-ray images placed into a panoramic image frame during the entire procedure. The method has been systematically analyzed in a simulation framework in order to investigate its accuracy and robustness. Furthermore, we validated our protocol via a preclinical study comprising 19 human cadaver legs. Four surgeons determined MAD measurements using our X-ray panorama and compared these values to a gold-standard CT-based technique. The maximum average MAD error was 3.5mm which shows great potential for the technique.