High tibial osteotomy (HTO) is a surgical procedure that involves cutting the proximal tibia in an attempt to change the weight bearing axis from the medial to the lateral compartment of the knee. It is especially appropriate for young and middle age active patients who have a primary, degenerative arthrosis involving the medial compartment in a malaligned limb, and causing pain and functional limitation. Over the last ten years, the indications for HTO have expanded to include patients with initial cartilage damage that can be treated with one of the new cartilage repair techniques and patients with chronic ligament deficiency, associated with a varus malalignment. The opening wedge HTO is a relatively new technique, compared to the Coventry’s lateral closing wedge osteotomy. It turns upside down the method of correction of the varus deformity, adding a wedge medially and is based on a dedicated system of instruments and plates (Arthrex, Naples, Florida). In the international literature, many series have shown encouraging middle-term results following HTO. The majority of authors agree that there is a gradual decline in the quality of the result with time. In general, HTO has been demonstrated to be effective for approximately five years in 85–90% of the patients, and for about two thirds (65%) of them over ten years from the operation. Aglietti, in a review of 139 knees that had HTO, noted excellent and good results in 64% of the knees after a follow-up period of at least 10 years. However, a tendency for results to deteriorate with time was observed, with satisfactory results in 64% with more than 10 years follow-up evaluation, 70% of the knees with six to 10 years evaluation and 87% of the knees with two to five years evaluation. Insall (21) reported 97% of good results at two years, 85% good results at five years and 63% good results at nine years. At nine years, deterioration in these patients was primarily the result of time, and not recurrence of deformity. In contrast with Insall, other authors have reported instead that deterioration of results is due to recurrence of deformity. From our personal experience, we have a series of 55 patients, six bilateral, operated on between 1992 and 2000, with the opening wedge technique, follow-up six to 14 years. The average age was 49 years, 32 men and 23 women. The results were evaluated using the International Knee Documentation Committee (IKDC) rating scale and the Hospital for Special Surgery (HSS) scoring system. Pre-operatively, 38 patients belonged to group “C” and 17 to group “D” of the IKDC rating scale. At follow up, all the 38 patients of group C passed to group B. Of the 17 patients in group D, 13 passed to group C and 4 to group B. All the patients improved their conditions at least one category. The same results evaluated with the HSS score system resulted in 33 knees poor and 22 fair before the HTO. At follow up, we had 14 excellent, 38 good and 3 fair. These particularly satisfying results may be influenced by the improper use of the HSS score system, which was designed to evaluate results in prosthetic replacement surgery.
Arthroscopic controlled retrograde drilling of femoral and tibial sockets and tunnels using a specially designed cannulated drill pin and retrocutter (Arthrex Inc, Naples FL.) provides greater flexibility for anatomical graft placement and in revision cases avoids previous tunnels and intra osseus hardware. Inside out drilling of femoral and tibial sockets minimises incisions and eliminates intra articular cortical bone fragmentation of tunnels rims common to conventional antegrade methods. This technique is also ideal for skeletally immature patients since drilling and graft fixation through growth plates may be avoided. Initial tunnel-referencing cannulated drill guide pin placement is carried out from outside-in. This technique (out-in/in-out) combines the advantages of the two-incision and the one-incision technique. In fact it permits us, as in the two-incision technique, to drill a pin guide from outside to inside in order to obtain the correct anatomical insertion of the ACL, otherwise not reproducible from inside-out. Since November 2004 our preferred technique for hamstring (autogenous quadrupled semitendinosis/ gracilis) ACL reconstruction incorporates the above mentioned femoral socket creation. In recent years, arthroscopically assisted ACL reconstruction has become the procedure of choice. Initially, arthroscopic techniques required two incisions for outside-in drilling of bone tunnels, but there has been a trend toward using a single incision with inside-out of the femoral tunnel. Those who advocate the two-incision technique state that they do so primarily because they believe that the two-incision procedures makes accurate femoral tunnel placement easier. Harner found no difference in tunnel placement using the two techniques, while Schiavone found that the inside-out femoral tunnels were significantly more vertical in the one-incision procedure. We have performed two-incision ACL reconstruction routinely since 1977, with very favourable results. The recent variation in our technique affords a reduction in morbidity, associated with improved cosmesis and quicker post-operative recovery. One factor related to our success appears to be a more anatomically positioned femoral tunnel, which in our hands, is difficult to accomplish with the single incision trans-tibial femoral socket creation. The retro-drill technique allows preparation of the correct anatomical femoral and tibial socket or tunnel, either with a very small lateral skin incision or without any skin incisions if the surgeon is using an allograft, and appears to represent a promising future technique in ACL reconstruction.
