For the adequate reconstruction, the knee joint and fracture lines should be irrigated and small debris should be cleared of. Reduction of the larger fragments is done by large pointed bone reduction forceps. Reduction is simple in type A or C fractures in full or hyperextended position of the knee. Sometimes longitudinal type B fractures can be reduced better with the flexed knee. In case of anatomical reduction of the articular surface, palpation of the joint from inside can be done for monitoring. If an inside-out technique is planned, prior to reduction, insertion of K-wires is done in an open manner. For the reduction of the fragments, the wires can be used as joysticks. Reduction is done by using one or two reduction forceps.
Choice of implant
Orthopedic implants manufacturers are providing a wide range of implants like locking plates, locking cortical screws, cannulated cancellous screw, wires and nails for the management of these fractures.
To resist the tensile stress, implants are required for the forces that transmitted through the patella. Tension band wiring is very effective in transforming distraction forces into compressing forces. If used properly, single lag screws can facilitate stability but it must not be used without a tension band excluding in longitudinal type B fractures. Articular osteochondral flake fractures can be set with the help of biodegradable pins until it heals.
Tension band wiring
The implants of choice are 1.25 mm stainless steel wire in combination with 1.6, 1.8, or 2.0 mm K-wires. 1.0 mm wire is used in exceptional cases only.
The small fragment 3.5 mm cortex screw is advisable which is also used as a lag screw. The 4.0 mm cancellous bone screw may be used, but it has its drawbacks. There may be a chance of reduction loss while inserting the screw due to the high density of the patellar bone.
As a substitute of K-wires, biodegradable pins (1.6–2.0 mm diameter) can be used to fix osteochondral fragments. These implants are composed of polyglycolic acid, polydioxanone or polylactic acid. Polyglycolic acid begins to lose stability after 1–2 weeks; while polylactic acid holds stability for 6 months. The positive point is that there is no need of implant removal. These implants are suggested for adaptation of unloaded fragments but not for areas of high mechanical stress. It is also applicable to resorbable suture material, which do not equal the tensile strength of metallic wires. Various factors account for the biocompatibility of these implants. Local foreign-body reactions should be considered significantly.
Tricks and hints for surgical treatment
Generally, open fractures require operative treatment. Debridement of contused or contaminated soft tissue must be done in combination with irrigation. Jet lavage can be done in critical cases. In order to maintain blood supply, stripping of soft-tissue from the bony fragments should be averted.
First of all, the identification of extent of the injury is required because the preoperative x-ray fails to show all fracture lines. Identification of any extra-articular fracture lines can be possible by clearing a very small amount of overlapping tissue (1 or 2 mm) at the fracture edges. Gaps, steps, and the amount of damages or impacted cartilage are considered and loose fragments are removed from the knee. Then irrigation of joint is done and after that examination of articular surface of the relative femoral condyle is imperative.