[Relationship between lower limb alignment distribution and short-term clinical results after primary total knee arthroplasty in patients with varying degrees of knee varus].

OBJECTIVE: To analyze the relationship between the distribution of lower limb alignment and short term clinical efficacy in patients with varus-type osteoarthritis after primary total knee arthroplasty (TKA). METHODS: From December 2016 to March 2018, 87 patients (101 knees) with knee osteoarthritis were treated with the first total knee arthroplasty by the same medical group, including 21 males(25 knees) and 66 females(76 knees), ranging in age from 51 to 85 years old, with a mean of (67.6±7.0) years old. According to the difference of hip knee ankle angle (HKA) after total knee arthroplasty, the patients were divided into 4 groups:neutral position group (group A), -3°≤HKA≤3°, 50 knees;slight varus group (group B), 3°< HKA<6°, 20 knees;severe varus group (group C), HKA≥6°, 20 knees;valgus group (group D), HKA<- 3°, 11 knees. The preoperative sex, age, body mass index, operative side, preoperative and postoperative knee joint activity, HSS score, KSS clinical and functional score were compared among the 4 groups, and the relationship between the force line distribution of femoral and tibial prosthesis and the recent clinical effect was compared. RESULTS: All the patients were followed up with a mean duration of(18.4±4.0) months. The range of motion of knee joint, HSS and KSS scores at the latest follow-up after operation in the 4 groups were higher than those before operation, and the difference was statistically significant (P<0.001). There were significant differences in HSS and KSS scores among the 4 groups at the latest follow up (P<0.05);and the results in group A were better than those in group C and group D (P<0.05);the results in group B were better than those in group C and group D (P< 0.05);there was no significant difference between group A and group B or group C and group D(P>0.05). There was no significant difference in knee joint activity among the 4 groups. The score of femoral prosthesis force line within ±3°was better than that of the other group (P<0.05), and the score of tibia prosthesis force line had no significant difference between within ±3° group and other group (P>0.05). CONCLUSION: The short term clinical efficacy of patients with knee varus osteoarthritis after primary total knee arthroplasty is related to the distribution of lower limbs alignment. The short-term clinical efficacy of slight inversion position can be similar to that of neutral position. The force line distribution of femoral prosthesis is related to the short term clinical efficacy after primary knee arthroplasty.

Modified trapdoor procedures using autogenous tricortical iliac graft without preserving the broken cartilage for treatment of osteonecrosis of the femoral head: a prospective cohort study with historical controls.

BACKGROUND: The aim of the present study was to investigate clinical and radiological outcomes of autologous tricortical iliac grafting performed through a window created at the femoral head without suturing the opened articular cartilage for the treatment of osteonecrosis of the femoral head (ONFH), called modified trapdoor procedures. MATERIALS AND METHODS: A total of 59 consecutive patients (67 hips; 36 males and 23 females) with ONFH were included in this study, which was conducted from April 2009 to March 2012. Patients' age ranged from 27 to 46 years old, with a mean age of 36.3 years. Harris hip scores (HHS) were used to evaluate hip function pre- and postoperatively. Anteroposterior and frog-position X-rays and magnetic resonance imaging (MRI) were conducted to assess lesion location, size, and ARCO stage. Clinical failure was defined as score < 80 points or treatment by total hip arthroplasty (THA). Radiographic failure was defined as a > 3 mm of collapse in the hip. This group was retrospectively matched according to the ARCO stage, extent, location, etiology of the lesion, average age, gender, and preoperative Harris hip score to a group of 59 patients (67 hips) who underwent the "light bulb" approach between March 2007 and April 2009. RESULTS: Mean follow-up was 91.2 ± 13.6 months (range, 75-115 months). Mean HHS was 91.3 ± 4.5, compared with 83.1 ± 4.5 in the "light bulb" cohort at the 6-year follow-up examination (P < 0.001). At the 6-year follow-up, for modified trapdoor procedures, five hips (8.5%) were classified as clinical failure, and three hips underwent total hip arthroplasty; seven hips were classified as (10.4%) radiographic failure. The clinical and radiographic failure of the hips treated with the modified trapdoor procedure was significantly lower compared to the hips treated with the "light bulb" procedure (P < 0.05). Survival of the joint was not significantly related to the location of the femoral head lesion between two groups; however, better clinical and radiographic results were observed in modified trapdoor procedures with size C and the ARCO stage III. CONCLUSION: The present study demonstrated superior midterm clinical results in ONFH with the use of autologous tricortical iliac block graft through a femoral head window, without suturing the opened articular cartilage. The femoral head-preserving procedure was superior compared to the "light bulb" procedure treatment in patients with postcollapse osteonecrosis and large lesion.