of the Distal Femur, Knee, Tibia, and Fibula

Fig. 23.1

(a, b) X-rays of a closed low Y-type intra-articular distal femur fracture. (c, d) ORIF by reestablishing the condyles with two compression screws and gentle insertion of a retrograde SIGN nail. Only one locking screw could be placed in the nail. Patient can do ROM exercises, but weight bearing is limited by the intra-articular fracture

When hardware for rigid or semirigid internal fixation is unavailable, there are three options: external fixation, skeletal traction, or pins and plaster. If sound external fixation can be achieved without spanning the joint, it should be considered. Spanning the joint is no better than cast immobilization, with the added risk of pin track infection.

When there is no or minimal comminution, temporary nonrigid fixation with Steinmann pins incorporated in a long-leg cast—as detailed above but without the plates—is another alternative, provided fixation is secure enough to maintain acceptable alignment. Only remove pins and cast at 6 weeks if early callus is visible by x-ray. If in doubt, continue the pins and cast or hinged cast bracing another 4–6 weeks.

Proximal tibial skeletal traction is the last resort. It should be done on a Bohler-Braun frame, if available, to reduce the deforming forces of the gastrocnemii. This confines the patient to bed for 4–6 weeks, at which time the fracture should be clinically “sticky” and amenable to cast treatment for another 6 weeks.

An alternative to conventional traction is the Perkins traction technique, in which active knee ROM exercises are started as soon as 3–4 days after the fracture and progressed as pain allows (see Chap. 13).

Intra-articular Distal Femur Fractures

Intra-articular distal femur fractures involve one or both condyles. An undisplaced intra-articular component can be difficult to diagnose, particularly with poor-quality x-rays. A high index of clinical suspicion mandates obtaining good-quality imaging. A knee hemarthrosis with fat droplets can give additional information, especially in undisplaced fractures. The principle of anatomic restoration of joint surfaces applies to the treatment of these fractures, and any step-off >2 mm should be treated. Hardware availability will determine the rigidity of the fixation and thus the post-op regimen.

Since screws, wires, and pins are almost always available, one can at least reduce and fix the joint surface as anatomically as possible and convert the fracture to an extra-articular one, to be managed as described above. Even if technically and biomechanically unsatisfying, a good articular reduction with lag screws and/or pins, even if not a rigid fixation, will significantly improve the long-term functional prognosis (Fig. 23.2).

../images/270913_2_En_23_Chapter/270913_2_En_23_Fig2a_HTML.png — Fig. 23.2

Another way to treat a distal intra-articular fracture. (a, b) Admission AP and lateral x-rays. (c, d) Postoperative AP and lateral views showing inter-fragment compression of the articular components with one lag screw and temporary fixation of the extra-articular components with two crossed Steinmann pins that will be incorporated in a long-leg cast and removed at 6–8 weeks

../images/270913_2_En_23_Chapter/270913_2_En_23_Fig2b_HTML.png — Fig. 23.2

Another way to treat a distal intra-articular fracture. (a, b) Admission AP and lateral x-rays. (c, d) Postoperative AP and lateral views showing inter-fragment compression of the articular components with one lag screw and temporary fixation of the extra-articular components with two crossed Steinmann pins that will be incorporated in a long-leg cast and removed at 6–8 weeks

The AO Foundation web site on distal femur fractures: https://www2.aofoundation.org/wps/portal/surgery?showPage=diagnosis&bone=Femur&segment=Distal.

Injuries of the Patella and Ligaments About the Knee

Patella Fractures

Management of patella fractures depends on the age of the injury, the amount of comminution or displacement, associated soft tissue injuries, and availability of hardware. Undisplaced patellar fractures can be treated in a well-molded, full-weight-bearing cylinder cast for 6 weeks.

Articular step-offs ≥2 mm should be treated surgically. Figure-of-eight tension banding over two parallel K-wires remains the gold standard (Fig. 23.3). When wire is not available, braiding three strands of heavy non-resorbable suture can provide a cerclage strong enough for tension banding. Be sure to test it intraoperatively.

../images/270913_2_En_23_Chapter/270913_2_En_23_Fig3_HTML.png — Fig. 23.3

(a) X-ray of displaced comminuted transverse fracture of patella. (b) ORIF with figure-of-8 tension banding, after excision of small comminuted fragments. Dental wire was the only wire available; two strands were braided together

Using the plastic sleeve from a 14 or 16 French Jelco IV catheter facilitates passing the tension band wire under the tendons, instead of through them. The K-wires should be bent at one end for ease of later removal under local anesthetic. Early active ROM and full-weight bearing (WB) are encouraged.

When one pole is comminuted beyond repair, a partial patellectomy with reattachment of the quadriceps or patellar tendon to the remaining patella with transosseous sutures is a good solution. Fresh, completely comminuted (“blown-up patella”) fractures involving the entire patella should be treated initially by K-wire fixation of the main fragments and “containment cerclage” of the patella, to prevent further displacement. A cylinder cast is used for 3 weeks, after which gentle active ROM is started. Many patients will do well clinically despite radiographic evidence of some degree of mal-/nonunion. Total patellectomy can always be done later if patients are symptomatic. But they must be aware that pain may persist, and there will be residual weakness—a significant impairment for people living close to the floor. Whenever surgery is done, the surgeon should meticulously repair any associated lesions of the medial and/or lateral retinaculum.

Patellar nonunions may require only compression fixation with screws +/− tension banding if minimally displaced. Displaced nonunions are technically more difficult: significant soft tissue release may be necessary for end-to-end coaptation of the fragments. Small polar fragments are better excised than repaired, if symptomatic. The amount of pain or disability should dictate the need for surgery, not the x-ray appearance. The patient should be aware that the price to pay for surgical success of union is often some persistent stiffness (Fig. 23.4).

../images/270913_2_En_23_Chapter/270913_2_En_23_Fig4a_HTML.png — Fig. 23.4

(a, b) Clinical appearance of bilateral chronic patella nonunions with significant patella alta. X-ray appearance of (c) right and (d) left distal patellar pole nonunions with impressive proximal migration of the patellar body. This patient had the problem for years and had no pain but was unable to kneel or get up from the kneeling position without support. No surgery was offered

../images/270913_2_En_23_Chapter/270913_2_En_23_Fig4b_HTML.png — Fig. 23.4

(a, b) Clinical appearance of bilateral chronic patella nonunions with significant patella alta. X-ray appearance of (c) right and (d) left distal patellar pole nonunions with impressive proximal migration of the patellar body. This patient had the problem for years and had no pain but was unable to kneel or get up from the kneeling position without support. No surgery was offered

Quadriceps and Patellar Tendon Ruptures

Acute (up to 6 weeks old) rupture of the quadriceps or patellar tendons should be repaired surgically. Depending on the location of the rupture, transosseous sutures may be required. The repair should be protected in a well-molded cast in extension for 6 weeks, allowing full WB. Chronic ruptures require soft tissue mobilization, often tendon grafting, and extensive rehabilitation. Patients need to understand that there will be a trade-off between instability and stiffness.

The repaired construct may be augmented (our preferred technique) with a tendon or fascial graft tunneled transversally through the patella and woven through the tendinous remnant. The peroneus brevis (with proximal myo-tenodesis to the longus), palmaris longus tendon, or a strip of fascia lata can be used as graft. When doing an augmentation, it is preferable to tighten both the repair and the augmentation with the knee in maximum extension, tying the repair sutures first. The patella itself can be temporarily skewered to the distal femur or proximal tibia with a small Steinmann pin to relieve tension on the repair. A long cylinder non-weight-bearing cast is worn for 6 weeks after which time the Steinmann pin is removed and ROM started. If no Steinmann pin transfixes the joint, WB can start early in the cast. All these bone procedures on a weakened patella may create an iatrogenic fracture , which requires repair as described above.

Special consideration needs to be given to femur fractures undergoing open internal fixation after prolonged traction. Knee stiffness is common and often worsened by the relative lengthening of the extensor mechanism with the open reduction. Rigid fixation allows the knee to be manipulated, but this should be done with great care, and the goal should be modest. Any sudden “giving way” is suspicious of an extensor mechanism rupture, and clinical signs such as a palpable defect or lack of patellar motion warrant immediate surgical exploration and repair.

Patellar Dislocations

After reduction acute dislocations of the patella usually do well with nonsurgical management in a cylinder cast or an appropriate brace for 3 weeks. If on assessing postreduction stability, re-dislocation occurs spontaneously with knee flexion between 45 and 90°, surgical repair of the medial retinaculum and release of the lateral retinaculum will likely be needed. Patellae dislocated for more than 6–8 weeks do not relocate by manipulation alone.

Chronic patellar dislocations usually present with an extension lag, inability to independently squat or rise from the kneeling position, and varying degrees of pain. Instability and weakness may improve with surgical relocation that includes extensive lateral release, medial plication, and advancement of the vastus medialis. Although strength of the extensor mechanism will never be normal, the residual stiffness is usually better tolerated than the preoperative weakness and instability. Chondromalacia sets in early when the patellar cartilage has been damaged, and even a stable open reduction of a chronic patellar dislocation does not guarantee pain-free function. When pain is a major problem, a total patellectomy with realignment of the extensor mechanism might be the only option. Long-standing dislocations where the main symptom is weakness, not pain, and the patient is able to function adequately are better left alone (Fig. 23.5).