Intraoperative, fluoroscopy-based planning for complex osteotomies of the proximal femur

Intertrochanteric osteotomy of the proximal femur is a surgical technique that aims at changing the orientation of the proximal part of the femur in the hip joint by removing a bone wedge between the trochanters. Due to its six degrees of freedom, it presents a complex planning problem for the surgeon. In this paper, we propose an intraoperative planning system for proximal femur osteotomies. Based on two fluoroscopic images taken during the procedure, a primitive femur model is reconstructed, which then allows the user to interactively determine the osteotomy parameters and perform the intervention with the help of a navigation system. Besides the fluoroscopic images, no other imaging is needed. Compared to the traditional approach, this system allows the intervention to be performed with higher precision and less radiation exposure for both patient and surgeon, requiring only little time overhead. An in vitro study has demonstrated the high accuracy and ease of use of this system.     

Controlled bending instability in the healing of diaphyseal osteotomies in the rat femur

Ninety-six rats underwent a midshaft transverse osteotomy followed by osteosynthesis with an intramedullary nail, so that the effect of bending instability on time to union and on the mechanical properties of experimental diaphyseal fracture could be evaluated. Rotation was reduced by cementing both nail ends to the bone. Rigid nails made of stainless steel were used on one group and flexible nails made of polyacetal resin were used on another group. Serial radiographs were evaluated at 4-6-week intervals. Twelve animals with either nail type were killed at 4, 8, 16, and 24 weeks. Both femora were mechanically tested and the callus diameters were measured. There was no significant difference in time to union between the two groups. The cross-sectional area of callus was significantly higher at 8 and 16 weeks in femora with flexible nails. The strength, toughness, and resilience of the bone increased in this group until 24 weeks. Between 16 and 24 weeks, these parameters did not improve in femora with rigid nails. Poorer mechanical properties in femora with steel nails are interpreted as an effect of stress protection of the bone. This study, therefore, indicates that flexible nails prevent stress protection effects without delaying union.     

Pauwels' linear osteotomy or alloplasty in pseudarthrosis of the femur neck

Non-unions of the neck of the femur are still observed today in spite of all the improvements which have been made in the surgical treatment of median fractures of the neck of the femur. Linear osteotomy according to Pauwels is technical relatively simple to perform and yields good results. Such linear osteotomy is performed in children and young adults only even if the head of the femur is not rounded. Indication for alloplasty is now more liberal even in relatively young adults since cement-free implantation of total prostheses has proved successful. Indication for performing replacement of the head alone, is very rare. Palliative measures, such as Girdlestone or resection angulation osteotomy are performed in our patients subsequent to septic complications only.     

Treatment of pseudarthrosis of the lower third of the femur]

The results of surgical for pseudarthrosis of the lower third of the femur in 11 patients, using a modified King technic, are reported. To improve fixation of a distal fragment the authors suggest to employ two CITO pins with diverging ends at the level of femoral condyles with an additional compression by two rings of the Ilizarov apparatus. Plaster cast immobilization was not utilized. This method of fragments fixation provides an early motion of the knee joint. Roentgenologically and clinically the consolidation of fragments was noted after 4--5 months, the knee joint function being restored.     

Closed intramedullary osteotomies of the femur

Closed intramedullary osteotomies offer a safe way to correct many femoral deformities. It is the safest method for correcting leg length inequality in adults, having a low infection rate and low complication rate. Unfortunately, the procedure, is technically demanding, requiring great attention by two surgeons. The derotational osteotomy is not nearly as complex; it is a relatively simple procedure for a surgeon experienced in closed intramedullary nailing. Correction is adequate with goniometer measurement, but an interlocking nail is necessary to maintain position. Correction of angulatory deformities is more difficult and requires careful study of anteroposterior, lateral, and oblique radiographs to be certain that the procedure is technically possible. Intramedullary bone grafting is frequently necessary for an open wedge. Distal osteotomies are encumbered by nonunion problems.     

Supracondylar femur osteotomies around the knee

Background

Similar to the re-appreciation of high tibial osteotomy (HTO), supracondylar distal femur varus osteotomy (SCO) for lateral compartment osteoarthritis (OA) of the knee has gained renewed interest as new knowledge has become available on the influence of malalignment on the development, progression and symptoms of OA. Furthermore, the less than optimal results of knee replacements (TKR) in younger patients have also led to renewed interest in joint-preserving treatment options.

Purpose

Varus SCO has not had the same success or widespread use as valgus HTO. The goal in SCO is similar to HTO, to shift the load from the diseased to the healthy compartment, in order to reduce pain, improve function and delay placement of a TKR. Valgus OA however occurs much less frequently than varus OA and varus SCO is considered a technically more demanding procedure. In the past the surgical techniques for SCO were mainly dependent on difficult-to-use implants making the procedure more complex. Complication rates related to the failure of fixation up to 16?% have been reported.

Disussion

The new biplane osteotomy technique fixated with a locking compression plate is very stable; bone healing potential is optimal using this technique and takes 6–8 weeks. Full weight bearing before full bone healing is possible without loss of correction.

Conclusion

In this article, patient selection, planning, surgical techniques, stability of fixation, and bone healing are discussed. Varus supracondylar osteotomy is a viable treatment option for a well-defined patient group suffering from valgus malalignment and lateral compartment osteoarthritis, and in addition may be considered in ligamentous imbalance and lateral patellofemoral maltracking.

     

A novel mouse model to study fracture healing of the proximal femur

The majority of fractures, especially in elderly and osteoporotic patients, occurs in metaphyseal bone. However, only a few experimental models exist to study metaphyseal bone healing in mice. Currently used mouse models of metaphyseal fracture healing are either based on drill hole defects, lacking adequate biomechanical stimulation at the site of fracture and therefore endochondral ossification in the fracture callus, or are introduced into the distal part of the mouse femur stabilized by a locking plate, which is challenging due to the small specimen size. Therefore, the aim of the current study was to develop a new mouse model to study metaphyseal fracture healing of the proximal femur. We chose a combination between an open osteotomy and a closed intramedullary stabilization. A 24 G needle was inserted into the femur in a closed manner, then an osteotomy was made with a 0.4-mm Gigli wire saw between the third and the lesser trochanter of the femur using an open approach. Fractured femurs were analyzed using microcomputed tomography and histology at days 14 and 21 after surgery. No animals were lost due to surgery or anesthesia. All animals displayed normal limb loading and a physiological gait pattern within the first three days after fracture. We found robust endochondral ossification during the fracture healing process with high expression of late chondrocyte and early osteogenic markers at day 14 (d14). By day 21 (d21), all fractures had a bony bridging score of 3 or more, indicating successful healing. Callus volume significantly decreased from d14 to d21, whereas high numbers of osteoclasts appeared at the fracture callus until d21, indicating that callus remodeling had already started at d21. In conclusion, we successfully developed a novel mouse model to study endochondral fracture healing of the proximal femur. This model might be useful for future studies using transgenic animals to unravel molecular mechanisms of osteoporotic metaphyseal fracture healing.     

Multiple osteotomies with Zickel nail fixation for polyostotic fibrous dysplasia involving the proximal part of the femur

Involvement of the proximal part of the femur by polyostotic fibrous dysplasia is a progressive and disabling condition that leads to deformity. Morbidity is high in terms of recurrent fracture and deformity. Conventional methods of treatment have been ineffective in controlling these problems. The cases of four patients were reviewed to determine the natural history of polyostotic fibrous dysplasia involving the proximal part of the femur. In six femora, multiple osteotomies with fixation using a Zickel nail was utilized to provide definitive control of deformity and recurrent fracture and to allow the patients to return to normal activities.     

Bilateral pseudarthrosis of the femur after stress fracture

Summary Stress fractures of the diaphysis of the femur are very rare, particularly bilateral ones. We describe here a woman patient with bilateral pseudarthrosis of the femoral diaphysis which was the result of a stress fracture. The case is a rarity because the in question is of a dwarfish stature with great deformations of the lower extremities due to rickets. The patient has been closely examined for over 30 years. Our own explanation for the beginnings of stress fracture as well as for the pseudarthrosis development are given.     

Surgical therapy of metastases of the proximal femur and acetabulum]

An analysis of indications and operative techniques was carried out in 166 patients with skeletal metastases of the proximal femur and acetabulum. Complications as well as functional and oncological results clearly show advantages and disadvantages of different methods such as osteosyntheses, standard hip prostheses and tumour prostheses referring to the tumour's localization and extent.     

Proximal femur remodeling after proximal femur varus-derotational osteotomy in treatment of developmental dysplasia of the hip]

The aim of this paper was to assess proximal femur remodelling after proximal femur varus-derotational osteotomy in treatment of developmental dysplasia of the hip up to skeletal maturity. The analysis included 48 osteotomies performed in 33 children between 1st and 10th year of life. The follow-up period was on average 12 years. Supported by statistical evaluation the analysis showed persistent increase of the neck-shaft angle after proximal femur varus-derotational osteotomy, especially in the younger age groups. It also correlated strongly with the amount of varus fixed at the time of operation. On other hand femoral antetorsion corrected during surgery remained unchanged till skeletal maturity.