Posttraumatic Deformities of the Lower Limb

Fig. 26.1

(a) Radiographs of a 50 years old female patient that sustained a fracture of her left proximal femur AO/OTA type 31-A1.1 after a fall from 3 m height. The fracture was initially stabilized with a proximal femoral nail resulting in a multi-planar deformity. (b) Postoperative CT shows 3-dimensional malalignment. There is 15° varus, 2.2 cm translation, 1.5 cm shortening and 8° of internal rotation. (c) Surgery consisted in removal of the γ-nail, preparation of the blade canal with the seating chisel and mounting of a femoral distractor, that was fixed proximally in the iliac crest and distally in the femur shaft. Subsequent oblique intertrochanteric osteotomy was performed with an oscillating saw at the level of the former fracture site. Deformity was gradually corrected using a 5 mm Schanz screw that was placed in the subtrochanteric diaphysis. The screw was used as a joystick. Using the femoral distractor for correction of deformity, final fixation was achieved by interfragmentary lag screw and condylar plate osteosynthesis (d) Postoperative result after 4 months

Fig. 26.2

(a) The patient, 45 years old, sustained a distal femoral fracture AO/OTA type 33-A3.3 after a motorbike accident. The fracture was initially stabilized by retrograde nailing, resulting in a multi-plane deformity: there was 8° varus, 1.8 cm sagittal translation, 3.2 cm shortening and 10° external torsion. Clinical function was bad: extension/flexion 5/0/40°. (b) After quadricepsplasty according to Judet with resection of heterotopic bone and removal of the hardware, one-stage multi-planar correction of all deformities was performed. Fixation was achieved by a condylar plate osteosynthesis and bone defect were filled by cancellous bone grafting. Eight months after correction surgery, the plate was removed. Knee function improved: extension/flexion 0/0/130°

Also a suboptimal surgical technique such as failure to interlock can cause deformity (Fig. 26.3a–f). Problems occur in unreamed nailing when there is a mismatch between the diameter of the intramedullary nail and the medullary cavity. This may provoke either additional fractures in case of oversized nails or instability in case of undersized nails (Fig. 26.2a). The blasting of fracture fragments is not a rare complication of nailing, particularly not in transverse and oblique diaphyseal fractures. In reamed nailing, forced reaming of narrow medullary cavities without sufficient cooling by continuous irrigation and/or dull reaming devices may lead to excessive heat generation and bone necrosis (Fig. 26.4a–h). Since blood circulation offers effective cooling, the use of a tourniquet in reamed nailing is not recommended. Problems may also arise from insufficient hardware: breakage of intramedullary nails fortunately is a rare event nowadays. However, this complication is still observed, particularly in the proximal femur. Breakage of locking bolts increases instability and may cause secondary malunion. In former times, failure of locking bolts was sometimes tolerated as it was seen as a contribution to a desired “autodynamization” [1].

Fig. 26.3

(a) A 41-year old patient sustained a diaphyseal tibia fracture AO/OTA type 42-B1.2 after a ski accident. The fracture was initially stabilized by nailing. (b) Subsequent deep infection and non-union occurred. Infection was treated by reaming and exchange of the nail. The new nail was not locked proximally. Non-union of the long oblique diaphyseal fracture persisted and shortening occurred (c) After another exchange of the nail, a unilateral distraction fixator was mounted and Gigli osteotomy in the proximal tibia diaphysis was performed. (d, e) Continuous segmental transport with compression of the non-union was done. (f) Finally, bone healing of the osteotomy gap and the fracture site occurred 2 years after trauma

Fig. 26.4

(a) A 32-year old female patient had an inline-skating accident and sustained a diaphyseal tibia fracture AO/OTA type 42-A1.2. (b) The fracture was initially treated by reamed intramedullary nailing. Excessive reaming and the thick nail diameter led to heat necrosis of the cortical bone and the surrounding soft tissues, complicated by osteomyelitis. (c) Early salvage procedure was successful by removing the nail, medullary debridement by reaming and implantation of gentamycine bead chains. An external fixator was mounted and soft tissues were treated by vacuum sealing. (d) After infection was eradicated, a solid unreamed locking nail of smaller diameter was implanted. (e) The diaphyseal bone defect was managed by Gigli osteotomy at the level of the proximal diaphysis. (f) A unilateral distraction fixator was mounted. Subsequent continuous segmental transport bridging the long defect zone of burned bone was performed. (g, h) Radiological and clinical healing was achieved 20 months after primary surgery

26.2 Corrective Osteotomy

26.2.1 Diagnostic Evaluation

Early postoperative correction of malalignment is basically superior to later corrective osteotomy. As a consequence, early detection of any kind of malalignment is absolutely desirable. It is important to never ignore complaints of concerned patients.

By standard anteroposterior and lateral radiographs in good planes, frontal and sagittal malalignment as well as important shortening of the fracture site, e.g. due to telescoping, can be detected.

Whenever there is any clinical suspicion of torsional malalignment following intramedullary nailing of the femur and/or the tibia, early analysis of rotational malalignment by CT is essential.

26.2.2 Indications for Correction Osteotomies

After complete bone healing of the mal-aligned fracture site, correction osteotomy may offer an adequate answer to the malalignment problem. The indication for correction osteotomy depends on diverse criteria, including the patient’s age, compliance, risk factors and expectations. Other aspects are the experience and competence of the surgeon as well as the safety of the osteotomy procedure.

Deformities can be uni- or multidimensional. Uniplanar deformities occur in the frontal, the sagittal or the horizontal plane as well as in torsion.

Deformity correction in the frontal plane pursues two essential goals: clinical restoration of the original regular frontal axis and – even more important – restoration of a balanced biomechanical loading axis for the cartilage of the hip, knee and ankle joint. The preoperative assessment of the cartilage of the knee joint under these conditions is of particular interest. The arthroscopic evaluation of the cartilage in the medial and lateral knee compartment may modify a primarily intended frontal plane correction. In our opinion, knee arthroscopy prior to the frontal plane correction is mandatory since the quality of the knee joint cartilage may influence fine-tuning of valgus/varus modulation in relationship to the original preoperative planning [10].

The primary goal of deformity correction in the sagittal plane is full extension of all joints of the lower limb respecting the internationally acknowledged considerations and rules as proposed by Paley [7]. Incomplete flexion may be tolerated, but never a lack of extension. Although establishing maximum motion of all joints is desirable, a restricted range of motion in some cases has to be accepted due to post-traumatic adhesions and scars.

Translational deformities of the diaphyseal femur in the horizontal plane usually are hidden by the soft tissues of the thigh. Therefore, these deformities can be mostly tolerated. In the lower leg however, diaphyseal deformities may create relevant cosmetic alterations to the anterior tibial ridge. Local surgical smoothening of the anterior cortex sometimes may be an adequate treatment option. Knee-adjacent horizontal malalignment, particularly in the frontal plane, is even more important, since the deformity may affect the patellofemoral balance. Any corrective osteotomy has to re-establish the patellofemoral harmony in order to correct and avoid inadequate biomechanical forces acting on the joint surfaces and the cartilage.

Shortening with leg length discrepancy following operative fixation of femoral and tibial fractures is not infrequent [1]. Posttraumatic length differences less than 1.5 cm generally can be tolerated or treated by conservative means [8]. More severe length differences should be corrected, at least in younger patients. In the elderly, the indication for correction surgery depends upon the local and general risks of surgery, on the surgeon’s experience, on perioperative management, on the patient’s compliance as well as on his needs and expectations. The decision for corrective osteotomy will finally depend on a (self-) critical consideration of all pros and cons, reflecting individual patient- and surgeon-related aspects. Lengthening of the shorter limb mostly will be the preferred option. However, shortening of the longer, not injured limb may in specific situations be considered as an alternative as well.

Any lack of free external and internal rotation in the joint proximal to the injured bone resulting from torsional malalignment indicates the necessity for correction osteotomy. Any restriction of rotation in the hip joint due to malrotation is to be considered as an equivalent to a femoro-acetabular impingement, which is largely acknowledged as a risk factor for the development of osteoarthritis [11]. The same is true for torsional malalignment of the lower leg and a lack of free external and internal rotation of the knee joint. Length and torsion of the femur and tibia of both legs in one patient are usually symmetrical [8]. The healthy contralateral limb therefore basically defines the goal that has to be achieved by correction. In case of bilateral post-traumatic or congenital malalignment, the extent of correction is defined by standard values of joint motion [8]. The final result of any torsional correction must be free rotation of the ipsilateral proximal joint.

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