Background: Long-term studies indicate that the clinical success of high tibial osteotomy deteriorates with time. The purpose of this study was to evaluate the long-term results of a combined lateral closing and medial opening wedge technique for high tibial osteotomy with a minimum 15 years follow-up.

Materials and Methods: From January 1981 to June 1990, ninety-two patients underwent ninety-four high tibial valgus osteotomies. The average preoperative varus deformity was 13.50. The surgical technique consisted of a proximal lateral closing wedge osteotomy and grafting of the lateral wedge to the medial side of osteotomy. No internal fixation was used. A knee brace was used to maintain the 80 to 100 of valgus overcorrection. Seventy patients (72 high tibial osteotomies) with at least fifteen years follow-up were evaluated. Clinical evaluation was done with the Hospital for Special Surgery knee rating scale. Radiologically, femorotibial alignment, posterior tibial slope and the Insall-Salvati ratio were measured.

Results: The mean initial postoperative correction for all knees was to 8.3 ± 2.7 degrees of valgus. Survivorship was 83%, 60% and 45% at fifteen, twenty and twentyfive years after surgery with conversion to a total knee arthroplasty as endpoint of failure. This was 76%, 45% and 32% during the same time interval when a Hospital for Special Surgery knee score of less than 70 points was also considered as end-point. Twenty-six high tibial osteotomies required subsequent arthroplasty at an average of 15.6 years after the index procedure. At the time of the most recent follow-up, the average preoperative knee score of 67 points had improved to 82 points for the knees that had not undergone an arthroplasty. There were two superficial wound infections and one delayed union.

Conclusions: We believe that our technique of a combined lateral closing, medial opening wedge high tibial osteotomy resulted in good long-term outcome due to the off-loading of the diseased medial compartment with minimal complications.

For meniscal allograft transplantation, cell viability and metabolic activity are desirable. The various modalities of preserving the menisci described in the literature include, deep freezing, gluteraldehyde, lyophillisation and cryopreservation. Since formalin in low concentrations is a proven and inexpensive method of tissue preservstion, we attempted to analyse the viability of fibrochondrocytes in the meniscal tissue preserved in three different concentrations of formalin. Twenty-four rabbit menisci were assessed, three groups of 6 menisci each were preserved in 0.25%, 1%, 5% formalin for a period of three weeks; fourth group of 6 fresh menisci were used as controls. The uptake of Na235SO4 and LDH (lactate de-hydrogenase) were analysed for indirect evidence of cell viability. Menisci preserved in 0.25% of formaldehyde showed statistically similar Na235SO4 uptake and LDH activity as the controls; reflecting a similarity in the level of cell viability and metabolic activity. The menisci preserved in 1% and 5% formaldehyde solution showed a decreased radioactive uptake as well as LDH activity.

To evaluate the mechanism of dislocation of the navicular in complex foot trauma; we hypothesize this is similar to lunate/perilunate dislocations.

Our experience with 6 cases of total dislocation of navicular without fracture, and an analysis of 7 similar cases reported world-wide was used as the basis for this hypothesis. Radiographs of our patients and the published cases were analyzed in detail, and associated injuries/instablilities were assessed. The position of the dislocated navicular and the mechanism of trauma was considered and correlated, and this hypothesis was propounded.

When the navicular dislocates without fracture, it most frequently comes to lie medially, with superior or inferior displacement, depending upon the foot position at injury. It is hypothesized that the forefoot first dislocates laterally (perhaps transiently) at the naviculocunieform joint by an abduction injury; in all cases we recorded significant lateral injury (either cuboid fracture, or lateral midfoot dislocation). The relocating forefoot subsequently pushes the unstable navicular from the talonavicular joint, and depending upon the residual attachments of soft tissues, this bone comes to lie at different places medially. This is a similar mechanism to the lunate dislocation in the wrist, where the relocating carpus push the lunate volarly. Our clinical experience with these complex injuries has shown that the whole foot is extremely unstable. For reduction, the talonavicular joint has to be reduced first, and then the rest of the forefoot easily reduces on to the navicular. An understanding of injury mechanics allows us to primarily stabilize both the columns of the foot, and subsequent subluxation and associated residual pain are avoided.

Pure navicular dislocations are not isolated injuries, but are complex midfoot instabilities, and are similar to perilunate injuries of the wrist.

Twenty-six patients with femoral neck fractures were treated by open reduction, cancellous screw fixation and free fibular grafting. The patients were between 14 and 50 years of age. There were 16 old and 10 fresh fractures. Four patients had radiological signs of avascular necrosis before the treatment was instituted. Bony union was achieved in all patients except one, where the failure occurred because of a technical error. The patients were followed up for at least two years. No new case of avascular necrosis was detected after treatment, and there was clinical and radiological improvement in all four patients with pre-operative avascular necrosis.