Results of the 136 consecutive minimally invasive total knee arthroplasties.

The authors evaluated results of 136 consecutive minimally invasive total knee arthroplasties (MIS TKAs). The first 22 knees, performed with strict patient selection criteria, were determined as a learning experience. According to results of the next 114 knees, the average wound length was 9.2 centimeters and the average blood loss was 470 milliliters. At a mean follow-up of 14 months, the mean Knee Society score improved from 37.5 to 96 points with 96.3% of excellent results. Sixty-five knees, group A, had within 10 degrees of varus and 49 knees, group B, had more deformity. Clinical results of both groups were not statistically different in terms of operative time, blood loss, pain score, postoperative knee flexion at 2 weeks and 6 months and postoperative day of walking. However, the ability to straighten the knee was significantly delayed in knees with more deformity (group B). After gaining learning curve, surgeons could extend performing MIS TKA in patients with more knee deformity.

The remained patellar tendon strength after central one third removal : a biomechanical study.

The study was aimed at comparing the ultimate load bearing capabilities between normal patellar tendons (control group) and tendons after central one-third removal (removal group). Eleven fresh Thai cadavers provided study specimens. The average age of the cadavers was 24.86 +/- 7.13 years. Five tendons were used as control specimens and another six tendons underwent central one-third removal. The Instron 5583 testing machine and Cooper's technique of measurements were used to test the ultimate load. Rate of elongation of tendon was set at 500 mm/sec. The results showed that the removal group cross-sectional area was 48.67 mm2 or 49.64 per cent of the control group (98.04 mm2). The mean ultimate load of the control group was 4,365.59 N. The mean ultimate load of the removal group was 2,226.58 N or about 51 per cent. The energy level to breaking point in the control group was 72.17 J and 32.58 (45.14%) in the removal group. The average width of the central one-third portion was measured at 8.68 +/- 0.56 cm. Generally in a clinical situation, when the ultimate load is reduced to about half in the donor knee, care must be taken before allowing full weight to bear. Caution should also be emphasized in cases where a routinely 10 mm wide graft has been taken, as the donor tendon may be weakened by more than half and may rupture prematurely.

Comparison of tissue reaction and osteointegration of metal implants between hydroxyapatite/Ti alloy coat: an animal experimental study.

BACKGROUND: One important clinical application of hydroxyapatite (HA) is coating on metal implants to stimulate osteo-integration thus enhancing fixation of the implant to bone, especially plasma-sprayed HA coating applied on Ti alloy substrate. The poor bonding strength between HA and Ti alloy has been of great concern to orthopedists. The biocomptable coat such as Ti alloy (TiO2) coat is one method to improve adhesive strength. OBJECTIVE: The objective of this study was to detect and analyze possible differences in bone formation, bone integration and tissue reaction between group I (uncoated Titanium), group II (Hydroxyapatite coated Titanium), and group III (Hydroxyapatite/TiO2 coated Titanium) implant specimens when embedded into bony hosts. METHOD: Rectangular specimens were implanted into the femoral bone of adult dogs in randomly different sites including: proximal left, proximal right, distal left, distal right. The tailor-made implant specimens were inserted in 5 x 5 mm preprepared sockets. Radiographic evaluation was taken at 0, 1, 3 and 6 months. All animals were sacrificed at 3 and 6 months post implantation. The femoral bone containing implants were dissected and then prepared to be further investigated. The bone-implant interface was analyzed by H&E surface staining, radiography and scanning electron microscopy. Data concerning percentage of osteointegration and adhesiveness of hydroxyapatite layer from different kinds of implants along the entire length of each implants were collected and analyzed for evaluation of any significant differences. RESULTS: No osteo-integration was noted in Group I, but there was 25.57 per cent osteointegration in Group II and 28.63 per cent in Group III. No statistically significant differences were observed between Group II and Group III. However, the coating layer in Group II was found to have detached, in some area, from the metal substrate. Histologically, no adverse tissue reaction was found around any kind of implant. CONCLUSION: Biocompatable bond coat is one of the methods to improve adhesive strength of hydroxyapatite coated implants. In the present study it could be concluded that, besides the improvement in adhesiveness, the intervening TiO2 coating layer had no negative effect concerning bone formation and integration and also showed no adverse surrounding soft tissue reaction.

A capsular dilatation facilitated shoulder manipulation for treating patients with frozen shoulder.

Forty patients with a diagnosis of frozen shoulder who had symptom for an average of 8 months and failed conservative treatment of at least 6 weeks of physical therapy were treated with capsular dilatation facilitated shoulder manipulation. Post-manipulation, the patient underwent arthroscopy for visualization, fibrin debridement and bleeding point coagulation. All the essential intra-articular structures ie, glenohumeral ligament, rotator cuff were intact. Post-operatively, all patients revealed substantial gain in shoulder range of motion as well as diminished shoulder pain. The average flexion, abduction, and internal rotation gain were 76.9+/-8.9, 18.1+/-5.7, 9.6+/-7.1 degrees respectively. External rotation gain in the position of 90 degrees shoulder abduction and shoulder adduction were 53.0+/-9.97 and 31.4+/-7.2 degrees respectively. The average pain score by visual analogue scale pre and 6-month post-manipulation were 80.6+/-8.6 and 7.6+/-7.3 respectively with the average of pain score of 73.0+/-10.4. The authors proposed an effective and safe technique employing intra-articular pressure to facilitate shoulder manipulation in order to treat frozen shoulder.