[Imaging reasons for periprosthetic femoral fractures during the operation of total hip arthroplasty with anatomic prosthesis].

OBJECTIVE: To explore the imaging reasons for periprosthetic femoral fractures during the operation of total hip arthroplasty with anatomic prosthesis. METHODS: The fracture group consisted of 7 cases with periprosthetic femoral fracture (PPFF) and the non-fracture group 21 cases without PPFF during the operation of total hip arthroplasty (THA) among the 144 cases of primary THA with anatomic prosthesis. The preoperative plain films of hip joint were taken to calibrate the Sharp's angle, centre edge (CE) angle, femoral neck shaft angle, femoral anteversion angle of neck, bowing angle of proximal femoral shaft part, width of narrowest part in proximal femoral shaft. For each case, surgical details, age, height and weight were recorded. The results were analyzed with independent sample t test by software SPSS 17.0. RESULTS: No significant difference existed in general situation, Sharp's angle and CE's angle between two groups. And there were significant differences in femoral neck shaft angle (P = 0.040), femoral anteversion angle of neck (P = 0.026), bowing angle of proximal femoral shaft part (P = 0.024), width of narrowest part in proximal femoral shaft (P = 0.021). CONCLUSION: Dysplasia of proximal femur is a major cause of periprosthetic femoral fracture during the operation of total hip arthroplasty with anatomic prosthesis.

[Dermal hypoesthesia after total knee arthroplasty].

OBJECTIVE: To observe the incidence of skin sensory loss after total knee arthroplasty (TKA) and its natural history over time, and to identify the relationship between numbness area and incision length, tourniquet time, age and gender. METHODS: In the study, 132 patients (20 males and 112 females, with an average age of 69.75 years old, 135 cases of TKA) who underwent primary TKA with midline incisions were chosen and grouped chronologically (4 years, 3 years, 2 years, 1 year, 6 months, 1 month) to the investigation time point from Peking University First Hospital. All the operations were done by the same surgeon team with Stryker NRG and Depuy RP (without patellar resurfacing). Numbness incidence, numbness area, scar length, tourniquet time were recorded from the questionnaires sent to the patients and their medical records. RESULTS: 84.44% of the patients received a reduced skin sensory after TKA, 91.22% of which had a smaller numbness area gradually over time. The numbness area was decreased from the 1 month postoperation group to the 4 years postoperation group (P <0.001). The numbness area in 2 years postoperation group and more were significantly smaller than 1 month postoperation group (P=0.042, 0.004, 0.022), however, the skin flap numbness area had little change after 2 years (P>0.05). The hypoesthesia flap was completely lateral to the incision in 88.60% of the patients, and the numbness area covered the lateral skin and part of media skin to the incision in 11.40% of the patients. Numbness size had no relationship with the patients' gender, age, length of scar and tourniquet time (P>0.05). CONCLUSION: Most but not all the patients have a dermal hypoesthesia after total knee arthroplasty. The numbness area will gradually reduce over time. Numbness size is obviously smaller 2 years postoperation and then it will be stable. Gender, age, length of incision, and tourniquet time have no significant relationship with the size of numbness.

[Treatment of unstable chronic anterior cruciate ligament-deficient knee with osteoarthritis].

OBJECTIVE: Untreated ruptures of anterior cruciate ligament (ACL) lead to progressive meniscus tear and development of knee osteoarthritis over decades. The present study was designed to explore the early results of ACL reconstruction for the patients with unstable ACL-deficient knee with osteoarthritis. METHODS: Twelve patients with a mean age of 46 years (range: 35 - 54) underwent ACL reconstruction for ACL-deficient knee with osteoarthritis. All had chronic anterior instability and one or more episodes of knee instability. There was no previous diagnosis of ACL ruptures and no prior ligament surgery on involved knee. The preoperative duration of symptoms was 1 to 5 years. ACL reconstruction with arthroscopic single-bundle four-strand hamstring tendon autograft was performed for all patients. The laxity of knee was determined with Lachman and pivot tests. The patient subjective evaluation of function was examined with the modified Lysholm scoring scale pre- and post-operatively. RESULTS: Obvious articular cartilage degeneration and cartilage space stenosis in medial compartment were found in 9 patients and complex medial meniscus tear in 10. During the follow-up period of 9 - 36 months, there was no graft failure or loss of ROM (range of motion) for any of these knees. The symptoms of instability were relieved in all patients. The post-operative knee stability improved markedly. The modified Lysholm scores improved from a median pre-operative score of 62.0 points to an average of 89.5 at the last follow-up. CONCLUSION: ACL reconstruction with hamstring tendon may significantly relieve symptoms and improve knee functions in the patients of chronic anterior cruciate ligament-deficient knee with osteoarthritis, especially in those with primary symptoms of instability.