Hongyi Shao

Chinese Patients' Satisfaction With Total Hip Arthroplasty: What Is Important and Dissatisfactory?

Through validated self-administered questionnaires, we conducted a retrospective investigation in 818 patients (1009 hips) who underwent primary THA, to collect data on overall satisfaction plus satisfaction and importance rating for 16 specific functions and issues. Overall, 8.1% patients were dissatisfied with the surgery. The top 3 important items are pain relief, squatting, and walking. The top 3 dissatisfactory items are jogging, squatting, and rising after squatting. The strongest risk factors for dissatisfaction with walking were pain (6.1×), muscle weakness(3.7×), and LLD (3.3×). The strongest risk factors for dissatisfaction with squatting were low postoperative HHS ROM (3.7×) and muscle weakness (2.6×). For Chinese patients, ROM, muscle strength and LLD are very important.

The knee joint line position measured from the tibial side in Chinese people.

A magnetic resonance imaging study of 50 Chinese normal knees was conducted to determine the knee joint line position. The distances from the fibular head and the tibial tubercle to the joint line were measured, and each distance value was converted to a ratio relative to the anteroposterior tibial widths at the levels of the insertion of the patellar tendon and the apex of the fibular head. The distance to the joint line was 11.99 ± 1.20 mm from the fibular head and 20.48 ± 1.64 mm from the tibial tubercle. The fibular head and tibial tubercle are reliable landmarks. The distances and ratios can be used to determine the knee joint line position in revision surgery for the Chinese population.

Location of the Common Peroneal Nerve in Valgus Knees—Is the Reported Safe Zone for Well-Aligned Knees Applicable?

BACKGROUND Lateral soft-tissue release can jeopardize the common peroneal nerve (CPN) in total knee arthroplasty for valgus knees. Previous studies reporting safe zones to protect the CPN were based on well-aligned knees. We conducted this study to compare the localization of the CPN in well-aligned knees and in valgus knees. METHODS We conducted a consecutive 3-dimensional radiographic study on magnetic resonance images of 58 well-aligned knees and 39 valgus knees. We measured the distance between the CPN and the tibia, as well as the mediolateral, anteroposterior, and angular location of the CPN. We compared the results between well-aligned knees and valgus knees. RESULTS We found that there is an increased distance between the CPN and the tibia at the level of the tibial cut, but not at the joint line in valgus knees. It is safer to release the posterolateral capsule at the tibial side than at the level above this. The angular location and the mediolateral or anteroposterior location of the CPN in valgus knees are similar to those of well-aligned knees. CONCLUSION The location of the CPN in valgus knees is similar to that in well-aligned knees. The previously reported safe zone in well-aligned knees is applicable in valgus knees to protect the CPN.

Accuracy of Digital Tomosynthesis With Metal Artifact Reduction for Detecting Osteointegration in Cementless Hip Arthroplasty.

BACKGROUND Cementless hip arthroplasty is increasingly gaining popularity worldwide. Radiologic identification of osteointegration is key to confirming biologic fixation. We conducted the study reported here to determine the sensitivity and specificity of digital tomosynthesis with metal artifact reduction (TMAR), radiography, and conventional computed tomography in detecting osteointegration in cementless hip arthroplasty. METHODS We prospectively included data for 24 patients who underwent revision hip arthroplasty in our hospital, with 13 femoral and 14 acetabular cementless components retrieved that contained solid evidence of biologic fixation. All patients underwent 3 examinations before surgery, and evidence of osteointegration on retrieved prostheses was used as the reference standard. Seven orthopedic surgeons evaluated these images independently using uniform criteria. RESULTS On the femoral side, the sensitivity and specificity of detecting osteointegration were 73.8% ± 4.6% and 94.3% ± 1.5%, respectively, for TMAR; 50.4% ± 5.3% and 87.8% ± 2.1%, respectively, for radiography; and 36.4% ± 5.1% and 90.9% ± 1.9%, respectively, for CT. On the cup side, the corresponding values were 60.2% ± 8.3% and 86.4% ± 5.7%, respectively, for TMAR; 45.9% ± 8.5% and 66.4% ± 7.8%, respectively, for radiography; and 45.1% ± 8.5% and 73.5% ± 7.3%, respectively, by computed tomography. CONCLUSION TMAR significantly improved the accuracy osteointegration detection in cementless hip arthroplasty (P < .017).

Tests for predicting reimplantation success of two-stage revision for periprosthetic joint infection: A systematic review and meta-analysis

BACKGROUND Several tests are used before reimplantation to detect persistent infection in patients with periprosthetic joint infection (PJI) undergoing two-stage revision. However, there is no consensus as to the optimal tests for excluding persistent infection or predicting successful reimplantation by stage. We aimed to determine the accuracy of different tests used to detect persistent infection after the first stage, and/or predicting failure following reimplantation in patients with PJI. METHODS We conducted a systematic review and meta-analysis of PubMed, Embase and the Cochrane Library databases. Two reviewers independently conducted quality assessments and data extractions to estimate pooled sensitivity and specificity, diagnostic odds ratio and area under the receiver operating characteristic curves (AUSROC) for each test. RESULTS We included 24 studies published between May 1999 and September 2017. Synovial fluid polymorphonuclear neutrophils (PMN)% had the highest sensitivity of 0.70, followed by serum erythrocyte sedimentation rate (0.57) and spacer sonication fluid culture (0.53). Synovial fluid culture had the highest specificity of 0.97, followed by frozen section (0.93) and the Musculoskeletal Infection Society criteria (0.92). Spacer sonication fluid culture was the most accurate test with an AUSROC of 0.8089, followed by synovial fluid culture (0.7749) and frozen section (0.7819). DISCUSSION Spacer sonication fluid culture had a relatively high diagnostic accuracy. We emphasize that no test can be used alone to exclude persistent infection beyond the first stage and/or predict failed reimplantation beyond the second stage. LEVEL OF EVIDENCE II, systematic review and meta-analysis of level 2 to level 4 studies with inconsistent results.

A New Physical Examination Technique for Evaluating Valgus Knee Deformity: Swing Test.

Valgus deformity can exist during knee flexion besides extension, which could lead to patellofemoral joint instability and soft tissue imbalance in the flexion gap, and thus complicate the surgical procedures. Valgus deformity during knee flexion can be measured by radiographic analysis using long‐film radiograph and computed tomography (CT) scans.[4] It usually results from a bone defect in the posterior part of the lateral femoral condyle (measured on CT scan) or valgus deformity in the tibia (measured on long‐film radiograph). However, it is difficult to inspect this deformity during the physical examination.

Topography of the periacetabular bone in Chinese patients – do current cages fit?

Background Understanding the anatomy of the periacetabular bone is critical for designing and implanting cages, as well as reconstruction of lost periacetabular bone. We aimed to study the topography of periacetabular bone and compare it with current cages to examine their fit in a Chinese population. Methods We performed three-dimensional measurement on computed tomography images of 105 hemipelves to delineate the topography of the periacetabular bone. We compared the bone with digital models of commercially available cages, and divided the results into three scenarios (fit, mismatch and unfit) according to absence or existence of overhang and the extent of contouring needed after implanting the cages to the pelves. Results Our measurement provided a representation of normal topography of the periacetabular bone. Only 21% of the patients studied had commercially available cages which fit their pelves, whilst there was no cage that fitted 59% of the patients even after extensive contouring. conclusion Current acetabular cages have low fit rates for the periacetabular bone in Chinese patients.