Linear influence of distal femur osteotomy on the Q-angle: one degree of varization alters the Q-angle by one degree.

PURPOSE: The effect of a distal femur varization osteotomy on patellofemoral biomechanics in genu valgum is unknown. The purpose of this study was to quantify the influence of frontal leg axis correction on the Q-angle with a novel three-dimensional (3-D) measurement method. METHODS: 3-D surface models of ten lower extremities were generated using patient computed tomography (CT) data. The preoperative 3-D Q-angle was measured using a novel defined and validated 3-D measurement method. Biplanar supracondylar osteotomies were simulated with different degrees of varus correction (from 1° to 15°) in one-degree steps beginning from the preoperative valgus deformity, resulting in a total of 150 simulations. Additionally, mechanical leg axis and 3-D Q-angle measurements were performed on 3-D surface models of the postoperative CT scans of the same individuals. Further, pre- and postoperative TT-TG distance was measured. RESULTS: Mean preoperative Q-angle was 15.8 ± 3.9° (range 10°-21.4°) with a mean preoperative mechanical leg axis of 6.5° ± 2.4 valgus (range 3.8°-11.6° valgus). The Q-angle changed linearly 0.9 ± 0° per 1° of varization. No difference was detected between simulated 3-D Q-angles and effectively corrected postoperative values (n.s.). TT-TG distance changed irregularly and minimally, and with no correlation to the degree of varization. CONCLUSION: Distal femur varization osteotomy has a linear effect on the Q-angle with a change of 1° per 1° of varization. The difference in TT-TG distance was mainly due to an unintentional rotational component implemented during surgery.

Fate of stable hips after prophylactic femoral varization osteotomy in patients with cerebral palsy.

BACKGROUND: Concurrent prophylactic femoral varization osteotomy (FVO) for stable hips has been performed in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for the contralateral displaced hip. However, there is currently a lack of studies investigating the outcome after the prophylactic FVO in stable hip. This study investigated the outcomes after FVO in stable hips with CP and influencing factors. In addition, this study compared the outcomes with those after hip reconstructive surgery in the contralateral displaced hip. METHODS: This study included 119 CP patients with 224 hips (80 stable, 144 displaced) undergoing hip reconstructive surgery including FVO. Migration percentage (MP), neck-shaft angle (NSA), and head-shaft angle (HSA) were measured through preoperative and follow-up hip radiographs. All hips were divided into the stable (MP ≤ 33%) and displaced hip groups (MP > 33%) according to the preoperative radiographs, and the annual changes in the radiographic indices after FVO were analyzed. RESULTS: In stable hip group, MP did not significantly increase over time (p = 0.057) after prophylactic FVO. In displaced hip group, MP significantly increased over time (1.6%/year, p < 0.001). MP was significantly decreased in cases of concomitant Dega pelvic osteotomy in both stable (14.5%, p < 0.001) and displaced hips (18.9%, p < 0.001). CONCLUSIONS: Prophylactic FVO in the stable hip in patients with CP showed good surgical outcomes, without a risk of hip displacement throughout the follow-up duration, while hip reconstructive surgery in the displaced hip was associated with a risk of increased hip displacement.

Effect of Medial Closing Wedge Distal Femoral Varization Osteotomy on Coronal Ankle and Hindfoot Alignment.

BACKGROUND: To date, only a few studies have reported postoperative changes in coronal ankle alignment after valgus knee correction through medial closing wedge distal femoral varization osteotomy (MCWDFO). This study aimed to measure the changes of MCWDFO on coronal ankle and hindfoot alignment. METHODS: We retrospectively reviewed the radiographic findings of 27 consecutive patients (34 cases) with knee valgus malalignment who underwent MCWDFO for either lateral knee joint osteoarthritis (OA) or recurrent patellar subluxation/dislocation (RPD). Several radiographic parameters were measured and compared based on the reason for operation, followed by the status of preoperative hindfoot alignment (hindfoot alignment angle [HAA] > 4 degrees, varus; -4 degrees ≤HAA ≤ 4 degrees, neutral; HAA < -4 degrees, valgus) in each group. RESULTS: Overall, pre- and postoperative hindfoot alignments were within the neutral alignment range and were not significantly changed after the operation (P > .05). Nineteen cases were for lateral knee OA and 15 were for RPD, respectively. In both groups, preoperative neutral hindfoot alignments accounted for the largest portion (52.6% in the lateral OA group; 80.0% in the RPD group). Postoperatively, regardless of the reason for operation, hindfoot alignments changed toward the neutral range in all subgroups (ie, no changes in the preoperative neutral group; increased in the valgus group; decreased in the varus group). CONCLUSION: We recommend that surgeons leave the hindfoot untouched when they plan the MCWDFO to correct knee joint valgus malalignment concomitant with hindfoot valgus or varus deviation as the hindfoot malalignment appears to change toward the neutral range postoperatively. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Rehabilitation protocol after osteotomy of the tibia and varus femur - Case study.

The knee rehabilitation in the aquatic environment has been used to start the rehabilitation of the lower limb earlier and improve joint movements, as it reduces pain and allows for earlier weight loading . The aim of the study was to develop and describe the effects of a therapeutic exercise program in an aquatic environment, in a clinical case of osteotomy of the tibia and the varus femur. A 15-year-old girl, submitted to an osteotomy of the tibia and the varus femur, completed a therapeutic exercise program in aquatic environment for a total of 30 sessions (3 sessions/week of 60 min). The subject was evaluated in two moments (at the beginning and at the end of the intervention ). The results showed an improvement in the various parameters evaluated (knee flexion: 66° vs. 125°, knee extension: -7° vs. -1°, and pain on movement: 6/10 vs. 0/10). We concluded the therapeutic exercise program in the aquatic environment used in this study had beneficial effects in the clinical case of tibial osteotomy and varus femur.

Résumé La rééducation en milieu aquátique , est une solution pour commencer plus tôt la rééducation du membre inférieur et d´améliorer les mouvements articulaires , car il réduit la douleur et permet d´apliquer plus tôt une charge dans les exercices . L´objectif de l´études fût développer et décrire les effets d´un programme d´exercices thérapeutiques en milieu aquatique, dans un cas clinique d´ostéotomie du tibia et du varus fémur . Une jeune fille de 15 ans, soumise à une ostéotomie du tibia et du varus fémur , a suivi un programme d´exercices thérapeutiques en milieu aquatique dans un total de 30 séances (3 séances par semaine de 60 minutes ). Le sujet a été évalué en deux moments (au début et à la fin de l´intervention). Les résultas de l´étude nous indique une amélioration des diferents paramètres évalués (flexion du genou : 66° vs 125 °; extension du genou : -7° vs -1°; douleur au mouvement : 6/10 vs 0/10). Nous avons conclus que le programme d´exercices thérapeutiques aquatiques de cette étude a des effets bénefiques dans le cas clinique de l´ostéotomie du tibia et du varus fémur.

Three dimensional-printed patient-specific cutting guides for femoral varization osteotomy: Do it yourself.

INTRODUCTION: In valgus knees of young patients, opening-wedge distal femoral osteotomy is a valid treatment option for axial corrections. It allows the surgeon to achieve accurate correction, which is directly related to the functional outcome and survivorship of the osteotomy. This study presents a new technique based on three-dimensional (3D)-printed cutting guides for opening-wedge distal femoral osteotomies, in which pre-operative planning and intraoperative executional accuracy play a major role. MATERIAL AND METHODS: Pursuing axial correction accuracy, 3D-printed patient-specific positioning guides and wedge spacers were both created and used by the surgeon to implement the femoral osteotomy. The proposed technique was performed in 12 consecutive patients (cases). The results were compared with 20 patients (controls) in which opening-wedge distal femoral osteotomies were performed following the traditional technique. Accuracy of the axial correction, surgical time, fluoroscopic time and costs were measured. RESULTS: More accurate axial correction with reduced surgical time (32min less), intraoperative fluoroscopic images (59 images less) and costs (estimated €412 less) were achieved with the use of the customized guides when compared with the traditional technique. DISCUSSION: Accurate correction of the axial alignment of the limb is a critical step in survivorship of the osteotomy. Improving the technique to enhance accuracy focused on this issue. CONCLUSIONS: The use of patient-customized cutting guides minimised human error; therefore, surgical time was reduced and accurate axial correction was achieved. The surgeon mastered all steps in a do-it-yourself philosophy style.