Background

Hoffa pad in Total knee replacement is a mystery. Very few studies have been carried out and no obvious results have been achieved.

Authors have been using kinematic computer navigation for a total knee replacement surgery since 2003. A contribution and advantage of computer navigation is well recognized. Exact guidance of both tibial and femoral osteotomy along with precise soft tissue balance respecting individual anatomic constitution is achieved by exact collection and computer evaluation of data by a use of special sensors and probes. Use of kinematic navigation in experienced hands minimizes deviation from physiological mechanical Mikulicz axis. This is considered the most important step to achieve a good long term outcome after total knee arthroplasty.

We have been recently using Brain Lab kinematic navigation system in both primary and revision knee arthroplasties. 200 primary and 20 revision knee arthroplasties are included in the retrospective 3 year follow up study. A navigated revision surgery is recently performed only in cases where the axial deformity does not exceed 10 degrees and where no significant bone loss is presented (bone defects less that ½ cm). Standard cemented components are used in both primary and revision cases. A primary navigated knee arthroplasty had no exclusion criteria in the above study.

Technique: Medial patellar approach technique is used, navigation probes are placed in standard distal femoral and proximal tibial position. Data are collected using navigation probes and sensors. Loosen components and cement are removed next. Navigated proximal tibial osteotomy, distal femoral osteotomy and soft tissue balance are performed. Gentamycin cementing of standard components (tibia first) is performed at the end. A final verification of component balance and data storage terminates the procedure.

No need for conversion to a revision knee system using stem and wedges was noticed in the above series. Following the above inclusion criteria standard cemented implants were used only. We conclude that the use of navigation in cases of relatively uncomplicated knee revision arthroplasty guaranties good mid term outcome, good soft tissue balance, saves money on expensive knee revision systems and guaranties an alternative of second stage revision surgery with a use of extensive revision systems. Standard implant selection does not apply for those with deep bone defects and axial deformation higher than 10 degrees.

Authors in the presentation document the arthroscopic method of treatment of tibial intercondylar eminence fractures in children age. They follow up the short-time and middle-time results after using this method in 20 patients.

Method consists in early arthroscopic revision of traumatized knee joint in children with avulsion of intercondylar eminence, haematoma irrigation and the management of the eminence avulsion depending on the size of the tibial bone fragment. Because of bleeding and fat release from traumatized bone is recommended using the water pressure pump. The reposition of the bone fragment to the original position is made after the fracture bed revision and inverted soft tissues removal. The reposition is recommended to do in 30 grade flection of the knee when LCA is maximally relaxed and fragment retention is optimal. After the reposition of the bone fragment we fix it by 2 crossed Ki wires inserted or percutaneously parapatellarly or by the arthroscopic portal using method outside-inside-out.. Immobilization is recommended in 30 grade flection position.

The evaluation of 20 patients after arthroscopic surgery shows on the x-ray excellent and very good results in all patients. In 16 cases the clinical examination result is excellent with no instability of the knee, stable LCA and no front shift sign. In 4 cases was found front shift sign without clinically significant anteromedial stress instability of the knee. In 1 case there was made conversion to open revision with suturing of the fragment by PDS suture. Because the bony fragment was 1cm2 large only the closed reposition and retention was not sufficient.

The method appears certainly gentle with minimal traumatization of the joint capsule. The above all advantage is in non traumatic metals replacement without second stage surgery and anesthesia. In 4 cases we saw temporary LCA hyperlaxity. We prerequisite passive tonization of the ligament while skeleton growth. Clinical results of the method are satisfactory comparable to the open reduction and fixation by suture or cerclage. The method is not recommended in cases with bony fragment smaller then 1cm2 for not sufficient retention. In these cases we do an arthroscopic verification followed by open reduction.