Wei-Ming Chen

Preoperative tibiofemoral angle predicts survival of proximal tibia osteotomy.

A prospective group study was done to clarify whether perioperative variables such as preoperative and postoperative tibiofemoral angles influence the survivorship of proximal tibia osteotomy as measured by conversion to arthroplasty and patient dissatisfaction. The results of 93 proximal tibial osteotomies in 82 consecutive patients with medial compartment osteoarthrosis were followed up for a mean of 10.9 years. All data were analyzed by the Kaplan-Meier survivorship method and the multivariate Cox proportional hazards model. Only the preoperative tibiofemoral angle was a predictor of conversion to arthroplasty and patient dissatisfaction. The ideal prognostic cutoff angle was 9° or less varus. Increasing the preoperative varus alignment 1° would result in a 1.2 (95% confidence intervals, 1.02-1.50) times higher risk of conversion to a total knee arthroplasty and a 1.5 (95% confidence intervals, 1.27-1.76) times higher chance of patient dissatisfaction. Factors such as age, gender, body mass index, Ahlbäck’s classification, and postoperative tibiofemoral angle were not significant. We think that proximal tibial osteotomy should be considered for patients with medial compartment osteoarthrosis and a preoperative varus alignment of 9° or less, whereas arthroplasty is a more suitable alternative for patients with preoperative varus alignment greater than 9°. Level of Evidence: Therapeutic study, Level IV (case series-no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.

Acetabular revision arthroplasty using jumbo cups: an experience in Asia

IntroductionVariable degrees of bony deficiencies often complicate revisional arthrolasties of acetabular components and represent challenges to orthopedic surgeons. Many solutions exist and cementless jumbo cup reconstruction had been proven to be a feasible and successful method. Our study aimed to access the results of these cementless giant cups for managing acetabular bony defect at one institute.Materials and methodsBetween March 2000 and March 2003, 47 revisions of the failed acetabular components using the so-called “Jumbo Acetabular Cups” were enrolled in our study. All cases were followed for at least 4xa0years. We defined the size of the jumbo cups for the Asians to be of an outside diameter of 64xa0mm for men and 60xa0mm for women, which were 2xa0mm smaller than the commonly used definition in the Western countries. The radiographic outcomes and the migration of hip centers were analyzed. The endurance of these giant sockets was estimated by the Kaplan-Meier analysis.ResultsAfter a mean follow-up of 65xa0months, only three implant failures requiring re-revision were identified. The estimated 5-year survival rate according to the Kaplan-Meier analysis was 94.5%. Radiographic analysis demonstrated an improvement of vertical hip center from 31 to 27xa0mm proximal to the interteardrop line. Eight (17%) cups exhibited radiolucent line around the bone-prosthesis interface but did not attenuate implant instability. The complication rate was not high. Dislocation happened in five (11%) patients. One deep infection was successfully reconstructed in stage surgeries after eradication of the infection.ConclusionWith the aid of novel implant-coating technique and materials, jumbo cup reconstruction can achieve stability and longevity through an adequate peripheral ring-contact, regardless of inadequate implant to host bone contact. We believe that this is a reliable and easily performed reconstruction for acetabular defect.

Monteggia type I equivalent lesion: diaphyseal ulna and radius fractures with a posterior elbow dislocation in an adult.

BackgroundA rare type I Monteggia equivalent lesion with a posterior dislocation associated with a diaphyseal radius and ulna fracture in an adult is described. The probable mechanisms of injury are speculated to include flexion of the elbow and pronation of the forearm.Methods and resultsEarly reduction of the dislocation and rigid fixation of the fractures helped to achieve excellent results.

No Significant Squeaking in Total Hip Arthroplasty: A Series of 413 Hips in the Asian People

Some studies have reported the presence of audible squeaking in ceramic-on-ceramic total hip arthroplasty (THA), and several factors such as implant malposition or poor soft tissue recovery have been described as the cause. Our purpose was to determine the squeaking rate in the Asian population with a consecutive series of ceramic-on-ceramic THA. From 2003 to 2009, 413 THAs were performed by a single surgeon using a minimally invasive modified anterior-lateral approach. Using both questionnaire and physical examination, no squeaking was identified in any cases with a minimum of 2-year follow-up. Complications occurred in 4 patients. The results of this study suggested squeaking phenomenon after ceramic-on-ceramic THA may be eliminated.

Intraoperative Extracorporeal Irradiation and Frozen Treatment on Tumor-bearing Autografts Show Equivalent Outcomes for Biologic Reconstruction

Background Immediately recycling the resected bone segment in a biologic limb salvage reconstruction is an option after wide resection of bone. Intraoperative extracorporeal irradiation and freezing are the two major tumor-killing techniques applied on the fresh tumor-bearing autografts. However, graft-derived tumor recurrence and complications are concerns affecting graft survival. Questions/Purposes We therefore asked: (1) Is there a difference in the proportion of patients achieving union by 18 months after surgery between the groups with extracorporeal-irradiated autografts and frozen-treated autografts? (2) Is there any difference in the frequency of graft-related complications for patients receiving either an extracorporeal-irradiated or a frozen-treated autograft? (3) Is there a difference between the techniques in terms of graft-derived recurrence? (4) Are there differences in failure-free grafts, and limb and overall survivorship between autografts treated by extracorporeal irradiation or by freezing? Methods During the study period we treated a total of 333 patients with high-grade osteosarcoma. One hundred sixty-nine patients were excluded. Overall, 79 of the enrolled 164 patients received recycled autografts treated with extracorporeal irradiation whereas the other 85 received frozen-treated autografts. The mean followup was 82 ± 54 months for the extracorporeal irradiation group and 70 ± 25 months for the frozen autograft group, and one patient was lost to followup. Complications and graft failure (revision required for primary graft removal) were characterized by adapting the International Society of Limb Society (ISOLS) system modified for inclusion of biologic and expandable reconstruction. The primary study endpoints were the proportion of patients in each group who achieved radiographic union, and had an ISOLS grade of fair or good host graft fusion at 6, 9, 12, and 18 months after surgery. Five-year survival data for graft failure and limb amputation were analyzed by a cumulative incidence function regression model whereas the Kaplan-Meier function was used to test the 5-year overall survival rate between the two techniques. Results With the numbers available, no differences were found in the accumulated proportion of patients achieving union between the groups at 6, 9, 12, and 18 months. Radiographic evaluation did not show differences in the average scores of compared criteria. However in the subchondral bone subcriterion, more patients receiving frozen-treated autografts had higher scores (p = 0.03). Complications leading to a second surgery were not different between extracorporeal irradiation and frozen autografts in aspects of soft tissue failure (Type 1B), nonunion (Type 2B), structural failure (Type 3A and Type 3B), or infection (Type 4A and Type 4B). No graft-originating tumor recurrence was found and there was no difference in Type 5A tumor progression originating from soft tissue in the groups (odds ratio, 0.8; 95% CI, 0.3-2.1; p = 0.7). Neither group showed a difference in the cumulative incidence for graft failure and limb amputation. Five-year overall survival rates were 83% and 84% (p = 0.69) for extracorporeal-irradiated and frozen autografts respectively. A decrease in survivorship was seen at 50 to 100 months after surgery for the extracorporeal irradiation group. Conclusion We segregated the ISOLS criteria evaluating the graft-mediated tumor progression into host- or graft-derived complications (Types 5B and 5C) in this study. With the available data, there was no difference in the incidence of tumor recurrence derived from irradiation- or frozen-treated autografts. Ongoing evaluations comparing 10-year survivorship for both groups will be helpful to elucidate the possible difference found after 100 months. Level of Evidence Level III, therapeutic study