Ching-Chuan Jiang

Changes in the moment arms of the rotator cuff and deltoid muscles with abduction and rotation.

The behavior of the moment arms of the rotator cuff and deltoid muscles was studied during simple and combine movements of abduction and rotation about the glenohumeral joint. This was done by experimental measurement of excursions of the muscles in an in vitro cadaver model and by use of a multiple-regression analysis to delineate the changes in the moment arms as a function of abduction and rotation. The results demonstrated the potential of some rotator cuff muscles to contribute to both abduction and rotation, the sensitivity of the abductor moment-arm lengths to internal and external rotation and of the rotator moment-arm lengths to the degree of abduction, and the capacity of the abductor moment-arm lengths of the deltoid to increase with increasing abduction. Characterization of this behavior resulted in an increased understanding of the complex role of the rotator cuff and deltoid muscles about the gleno-humeral joint and provided quantitative descriptions of functional relationships. This study demonstrates the capacity of the infraspinatus and subscapularis muscles to contribute not only to external and internal rotation, respectively, but also to elevation of the arm in the plane of the scapula, a role for which these muscles have been given little or no consideration. Furthermore, it demonstrates that the contribution of the infraspinatus to abduction is enhanced with internal rotation while that of the subscapularis is enhanced with external rotation. Thus, dysfunction of the supraspinatus muscle need not preclude good elevation of the arm, and rehabilitation to reprogram and strengthen the remaining muscles becomes an important consideration.

Evaluation of articular cartilage repair using biodegradable nanofibrous scaffolds in a swine model: a pilot study

The aim of this study was to evaluate a cell‐seeded nanofibrous scaffold for cartilage repair in vivo. We used a biodegradable poly(ε‐caprolactone) (PCL) nanofibrous scaffold seeded with allogeneic chondrocytes or xenogeneic human mesenchymal stem cells (MSCs), or acellular PCL scaffolds, with no implant as a control to repair iatrogenic, 7 mm full‐thickness cartilage defects in a swine model. Six months after implantation, MSC‐seeded constructs showed the most complete repair in the defects compared to other groups. Macroscopically, the MSC‐seeded constructs regenerated hyaline cartilage‐like tissue and restored a smooth cartilage surface, while the chondrocyte‐seeded constructs produced mostly fibrocartilage‐like tissue with a discontinuous superficial cartilage contour. Incomplete repair containing fibrocartilage or fibrous tissue was found in the acellular constructs and the no‐implant control group. Quantitative histological evaluation showed overall higher scores for the chondrocyte‐ and MSC‐seeded constructs than the acellular construct and the no‐implant groups. Mechanical testing showed the highest equilibrium compressive stress of 1.5 MPa in the regenerated cartilage produced by the MSC‐seeded constructs, compared to 1.2 MPa in the chondrocyte‐seeded constructs, 1.0 MPa in the acellular constructs and 0.2 MPa in the no‐implant group. No evidence of immune reaction to the allogeneically‐ and xenogeneically‐derived regenerated cartilage was observed, possibly related to the immunosuppressive activities of MSCs, suggesting the feasibility of allogeneic or xenogeneic transplantation of MSCs for cell‐based therapy. Taken together, our results showed that biodegradable nanofibrous scaffolds seeded with MSCs effectively repair cartilage defects in vivo, and that the current approach is promising for cartilage repair. Copyright

Multipotential mesenchymal stem cells from femoral bone marrow near the site of osteonecrosis.

Stem cell‐based therapies for degenerative disorders and injuries are promising in the new era. Multipotential mesenchymal stem cells (MSCs) from bone marrow (BM) are on the leading edge because they are easy to expand in culture while maintaining their multilineage potential. In vitro assessment of the chondrogenic and osteogenic potentials of cultured MSCs has been established, and the BM used in those experiments was exclusively from healthy donors via iliac crest aspiration. It is unknown whether human marrow obtained from femurs also contains these multipotential MSCs. We collected marrow from proximal femurs of two patients undergoing total hip replacement surgery for femoral head osteonecrosis and isolated and culture expanded MSCs to about 20 population doublings. These cells were homogeneously positive for β1‐integrin. When pelleted into aggregates and cultured in a medium containing transforming growth factor‐β3 for 14 days, the cells began to express mRNA for aggrecan and collagen type II and to deposit immunoreactive collagen type II and sulfated proteoglycans in the matrix, hallmarks of chondrogenic differentiation. These MSCs could also be differentiated into osteocytic lineage in vitro, as shown by increased expression of alkaline phosphatase activity and deposition of mineral content onto culture plates. These results indicate that femoral BM obtained during hip surgeries also contained multipotential MSCs. These data imply that direct replacement therapy using MSCs from in situ marrow may be possible in the future and that an MSC bank may be established by using marrow from this approach, bypassing the necessity for iliac marrow aspiration from healthy donors.

Repair of Articular Cartilage Defects: Review and Perspectives

Articular cartilage defects heal poorly and lead to catastrophic degenerative arthritis. Clinical experience has indicated that no existing medication substantially promotes the healing process and the cartilage defect requires surgical replacement, preferably with an autograft. However, there is a shortage of articular cartilage that can be donated for autografting. A review of previous unsuccessful experiences reveals the reason for the current strategy to graft cartilage defects with regenerated cartilage. Autologous cartilage regeneration is a cell-based therapy in which autogenous chondrocytes or other chondrogenic cells are cultured to constitute cartilaginous tissue according to the principles of tissue engineering. Current studies are concentrating on improving such techniques from the three elements of tissue engineering, namely the cells, biomaterial scaffolds, and culture conditions. Some models of articular cartilage regeneration have yielded good repair of cartilage defects, in animal models and clinical settings, but the overall results suggest that there is room for improvement of this technique before its routine clinical application. Autologous cartilage regeneration remains the mainstay for repairing articular cartilage defects but more studies are required to optimize the efficacy of regeneration. A more abundant supply of more stable cells, i.e. capable of maintaining the phenotype of chondrogenesis, has to be identified. Porous scaffolds of biocompatible, biodegradable materials that maintain and support the presentation of the chondrogenic cells need to be fabricated. If the cells are not implanted early to allow their in vivo constitution of cartilage, a suitable in vitro cultivation method has to be devised for a consistent yield of regenerative cartilage.

Effect of rotation on the axial alignment of the femur: pitfalls in the use of femoral intramedullary guides in total knee arthroplasty

Intramedullary alignment guides for total knee arthroplasty are currently routine instruments. However, in some cases, the intramedullary guide can be misleading because of unusual femoral bowing and the rotational position of the femur. To determine the effect of rotation, an intramedullary guide was inserted into seven normal adult anatomic specimen femurs that were then examined roentgenographically in known positions of internal and external rotation. A variation of 2.5 degrees was found between the positions of 20 degrees of internal rotation and 20 degrees of external rotation of the femur. Intramedullary instrumentation provides sufficient accuracy when the femur has a normal anatomic shape. However, when an excessive degree of femoral bowing is present, rotational attitudes can affect the roentgenographic measurements, and thus it is prudent to use the intramedullary and extramedullary alignment guides whenever the roentgenogram indicates an unusual angle of femoral resection.

Perioperative celecoxib administration for pain management after total knee arthroplasty – A randomized, controlled study

BackgroundNon-steroidal anti-inflammatory drugs (NSAIDs) are recommended for multimodal postoperative pain management. We evaluated opioid-sparing effects and rehabilitative results after perioperative celecoxib administration for total knee arthroplasty.MethodsThis was a prospective, randomized, observer-blind control study. Eighty patients that underwent total knee arthroplasty were randomized into two groups of 40 each. The study group received a single 400 mg dose of celecoxib, one hour before surgery, and 200 mg of celecoxib every 12 hours for five days, along with patient-controlled analgesic (PCA) morphine. The control group received only PCA morphine for postoperative pain management. Visual analog scale (VAS) pain scores, active range of motion (ROM), total opioid use and postoperative nausea/vomiting were analyzed.ResultsGroups were comparable for age, pre-operative ROM, operation duration and intraoperative blood loss. Resting VAS pain scores improved significantly in the celecoxib group, compared with controls, at 48 hrs (2.13 ± 1.68 vs. 3.43 ± 1.50, p = 0.03) and 72 hrs (1.78 ± 1.66 vs. 3.17 ± 2.01, p = 0.02) after surgery. Active ROM also increased significantly in the patients that received celecoxib, especially in the first 72 hrs [40.8° ± 17.3° vs. 25.8° ± 11.5°, p = 0.01 (day 1); 60.7° ± 18.1° vs. 45.0° ± 17.3°, p = 0.004 (day 2); 77.7° ± 15.1° vs. 64.3° ± 16.9°, p = 0.004 (day 3)]. Opioid requirements decreased about 40% (p = 0.03) in the celecoxib group. Although patients suffering from post-operative nausea/vomiting decreased from 43% in control group to 28% in celecoxib group, this was not significant (p = 0.57). There were no differences in blood loss (intra- and postoperative) between the groups. Celecoxib resulted in no significant increase in the need for blood transfusions.ConclusionPerioperative celecoxib significantly improved postoperative resting pain scores at 48 and 72 hrs, opioid consumption, and active ROM in the first three days after total knee arthroplasty, without increasing the risks of bleeding.Trial registrationClinicaltrials.gov NCT00598234

Immediate Effect and Predictors of Effectiveness of Taping for Patellofemoral Pain Syndrome a Prospective Cohort Study

Background: Taping has been used to treat patellofemoral pain syndrome for more than 20 years, but its effectiveness is still controversial. Purpose: This study was undertaken to investigate the effect and predictors of effectiveness of taping in the treatment of patellofemoral pain syndrome. Study Design: Cohort study; Level of evidence, 3. Methods: A total of 118 consecutive patients with patellofemoral pain syndrome were recruited; 100 of them completed this study. Patient sex, age, body mass index, Q angle, lateral patellar displacement, and lateral patellofemoral angle were recorded/measured. One therapist applied adhesive tape to each patient by the McConnell method. Patients scored their pain level on a 100-mm visual analog scale during stepping down from an 8-in platform, before and after taping. The change of score was evaluated by paired t test. Patients with a visual analog scale score decrease of 20 mm or more after taping were considered responsive, and the others were considered nonresponsive. The influences of the aforementioned factors, plus pretaping visual analog scale score, on the effectiveness of taping were analyzed by multivariate logistic regression. Results: The overall mean visual analog scale score decreased significantly after taping (from 49.0 to 29.3 mm; P < .001). There were 66 patients in the responsive group and 34 in nonresponsive group. Among the factors, body mass index, lateral patellofemoral angle, and Q angle were significant predictors of effectiveness. The responsive group had significantly smaller mean lateral patellofemoral angle, larger mean Q angle, and larger mean pretaping visual analog scale score than the nonresponsive group. Conclusion: Taping was an effective treatment for patellofemoral pain syndrome, but was less effective in patients with higher body mass index, larger lateral patellofemoral angle, and smaller Q angle.

The effect of posterior capsule repair upon post-operative hip dislocation following primary total hip arthroplasty

BackgroundHerein, we evaluated, retrospectively, the effect of posterior capsular repair upon postoperative hip dislocation subsequent to total hip arthroplasty (THA) incorporating a posterolateral approach.MethodsA total of 181 patients undergoing 204 primary non-complicated THA surgical procedures in the period from January 2000 to October 2005 inclusively were included in this study. The patients were separated into two groups by whether the posterior capsular repair had been incorporated in the surgical procedure. For the surgeon did not commence repairing the posterior capsule until July, 2003, all members in the group that did not undergo posterior capsular repair (142 hips from 131 patients) were collected since January, 2000 to July, 2003, while the members in the group that underwent posterior capsular repair (62 hips from 52 patients) were followed since July, 2003, to October, 2005. With a minimum follow-up period of 12 months, we evaluated the early post-operative dislocation rate.ResultsThe early postoperative hip-dislocation rate for the group who did not undergo posterior capsular repair appeared to be substantially greater (6.38% versus 0%) than the corresponding figure for the group the members of which underwent posterior capsular repair. In addition, patient demographics and the orientation of acetabular components for the replaced hip joints, as presented in postoperative radiographs, did not differ between the two groups.ConclusionThus, surgeons should include posterior capsular repair as an important step in the surgical procedures of posterolateral approach for all THA in order to reduce the likelihood of early hip dislocation subsequent to THA.

Risk Factors for Hip Fracture Sites and Mortality in Older Adults

BACKGROUND Our study was designed to (1) investigate the risk factors associated with cervical or trochanteric hip fractures; and (2) identify the risk factors for increased mortality in the elderly population sustaining hip fractures, after adjusting the miscellaneous baseline prefracture conditions. METHODS Two hundred seventeen elder patients with first-time, low-trauma hip fractures were enrolled. The follow-up time ranged from 35 months to 56 months. Potential risk factors for hip fracture types included (1) the 77 items on the self-reported questionnaire; (2) the body height, weight, and body mass index; (3) tests of coordination, handgrip strength, and peak expiratory flow rate; and (4) the bone mineral density variables. GTFN ratio was defined as the bone mineral density ratio between the greater trochanter and the femoral neck. Multivariate logistic regression and Cox regression models were used for analysis. The population attributable risk proportion of death to each significant factor was estimated. RESULTS Risk factors for trochanteric fractures include a GTFN ratio ≤0.81, being male, and an age >80 years. Risk factors for higher mortality after hip fracture included trochanteric fracture, body mass index ≤20 (kg/m), poor self-assessed health status, peak expiratory flow rate ≤215 (L/min), being male, illiteracy, and coordination abnormality, in the declining order of population attributable risk proportion. Trochanteric fractures had a significantly higher cumulative mortality at 36 months, 48 months, and 60 months than cervical fractures. CONCLUSIONS The novel GTFN ratio was associated with hip fracture sites. Clinically, cervical and trochanteric fractures represent different disease entities because of the difference in their mortality rates.

Quadriceps-Sparing, Minimal-Incision Total Knee Arthroplasty: A Comparative Study

Our study was conducted to compare radiographic alignments and functional outcomes with 2 approaches to minimal-incision total knee arthroplasty (TKA): the minimal-incision medial parapatellar (MP) approach and the quadriceps-sparing (QS) approach with side-cutting instruments. Sixty patients (80 knees) with primary osteoarthritis were randomly assigned to receive MP or QS TKA. Postoperative alignment of the femoral component was significantly less valgus, and postoperative alignment of the tibial component was significantly more varus with the QS approach than with the MP approach. One tibial outlier and 3 femoral outliers were observed with QS TKA. The overall postoperative hip-knee-ankle axis was more varus, and surgical time was longer with QS TKA. Short-term isokinetic peak muscle torque, postoperative pain, and functional outcomes did not differ between the approaches.