Yi-Sheng Chan

Treatment of osteonecrosis of the hip: comparison of extracorporeal shockwave with shockwave and alendronate

Background and purposeExtracorporeal shockwave therapy (ESWT) and alendronate are reported effective in early osteonecrosis of the femoral head (ONFH). We hypothesized that joint effects of ESWT and alendronate may produce superior results. This prospective study compared the results of ESWT and alendronate with that of ESWT without alendronate in early ONFH.Patients and methodsForty-eight patients with 60 hips were randomly divided into tow groups. There were 25 patients with 30 hips in group A and 23 patients with 30 hips in group B. Both groups showed similar demographic characteristics. All patients were treated with 6,000 impulses of ESWT at 28xa0KV (equivalent to 0.62xa0mJ/mm²) to the affected hip as a single session. Patients in group B also received alendronate 70xa0mg per week for 1xa0year, whereas patients in group A did not. The evaluations included clinical assessment, radiograph and MR image of the affected hip. Both groups were compared statistically using paired t, Mann–Whitney and Chi square tests with statistical significance at Pxa0<xa00.05. The primary end point is the need for total hip arthroplasty (THA). The secondary end point is the improvement in pain and function of the hip. The third end point is the progression or regression of the lesion on image study.ResultsThe overall clinical outcomes were improved in 83%, unchanged in 7% and worsened in 10% for group A; and improved in 77%, unchanged in 13% and worsened in 10% for group B. THA was performed in 10% of group A and 10% of group B (Pxa0=xa01.000). Significant improvements in pain and function of the hip were noted in both groups (Pxa0<xa00.001), however, the differences between the two groups were not significant (Pxa0=xa00.400, 0.313). On MR images, the lesions showed progression in 10%, regression in 47% and unchanged in 43% in group A, and progression in 7%, regression in 53% and unchanged in 40% in group B (Pxa0=xa00.830).ConclusionESWT and alendronate produced comparable result as compared with ESWT without alendronate in early ONFH. It appears that ESWT is effective with or without the concurrent use of alendronate. The joint effects of alendronate over ESWT in early ONFH are not realized in short-term.

Arthroscopic suture fixation of tibial eminence avulsion fractures.

PURPOSEnThis study presents the clinical results of a procedure for treating tibial eminence fractures of the anterior cruciate ligament (ACL) using arthroscopic reduction and No. 5 Ethibond sutures (Ethicon, Somerville, NJ).nnnMETHODSnThis prospective study analyzed 36 patients who underwent arthroscopic reduction and suture fixation for image-proven ACL avulsion fractures of the tibial eminence. The classification of Meyers and McKeever identified 6 type II, 16 type III, and 14 type IV fractures. The mean follow-up period was 34.4 months (range, 24 to 91 months). Follow-up assessment included Lysholm knee score, Tegner activity score, International Knee Documentation Committee (IKDC) score, and KT-1000 arthrometer (MEDmetric, San Diego, CA) and radiographic evaluation.nnnRESULTSnThe mean preoperative Lysholm score in the 36 knees was 38 (range, 28 to 54); the mean postoperative Lysholm score was 98 (range, 83 to 100). The mean preinjury and preoperative Tegner scores in the 36 knees were 7.5 +/- 1.5 (range, 5 to 9) and 3 +/- 1.7 (range, 2 to 5), respectively. The mean postoperative Tegner score was 7.3 +/- 1.7 (range, 5 to 9). At final follow-up, 34 patients (94.5%) were classified by IKDC score as normal or nearly normal (grade A or B). The IKDC classification was abnormal (grade C) in 2 patients (5.5%). All 36 fractures achieved union within 3 months. No significant complications, such as arthrofibrosis, loss of initial fixation, or wound infection, were noted.nnnCONCLUSIONSnTreating ACL avulsion fracture by arthroscopic suture fixation by use of 4 No. 5 Ethibond sutures can restore ACL length, stabilize fragments, promote early motion, and minimize morbidity.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Antibiotic-impregnated autogenic cancellous bone grafting is an effective and safe method for the management of small infected tibial defects: a comparison study.

OBJECTIVEnBone grafting plays an important role in reconstructing infected tibial nonunions. The effects of antibiotic-impregnated bone grafting in infection elimination and bone incorporation was reported in this retrospective study.nnnMETHODSnNinety-six patients treated for infected tibial nonunions were evaluated. These patients were managed with local antibiotic bead therapy and staged antibiotic-impregnated autogenous cancellous bone graft or pure autogenous cancellous bone graft. Patients were randomized to antibiotic-impregnated bone grafting or bone grafting-only groups on the basis of whether the admission date was odd or even. Patients were divided into two groups (antibiotic-impregnated bone grafting group and pure cancellous bone grafting group), according to the procedure used in preparing the bone grafts. The antibiotic-impregnated bone grafting group included 37 men and 9 women whose average age was 36 years (range, 17 to 72 years). The average follow-up period was 4.8 years. By using the Cierny-Mader staging classification of chronic osteomyelitis, 32 of 46 patients (70%) were stage 4A, and 14 of 36 patients (30%) were stage 4B. The pure cancellous bone grafting group included 39 men and 11 women whose average age was 37 years (range, 18 to 72 years). The average follow-up period was 4.5 years (range, 4 to 6 years). Thirty-nine of 50 patients (78%) were stage 4A, and 11 of 50 patients (22%) were stage 4B. The bone defects in both groups ranged from 2 to 4 cm.nnnRESULTSnWound healing and bony union were achieved in the antibiotic-impregnated bone grafting group. Only two patients had recurrent infections. The infection arrest rate was 95.6%. However, 9 of 50 patients in the pure cancellous bone grafting group had recurrent infections. The infection arrest rate was 82%. The antibiotic-impregnated bone grafting group had significantly superior results (95.6% vs. 82% chi2 test, p < 0.05) in infection elimination than the pure cancellous bone grafting group.nnnCONCLUSIONnAfter 4 to 6 years of follow-up, our results suggest that the use of impregnating antibiotics have no adverse effects on autogenic cancellous bone graft incorporation and could help to eliminate infection effectively.

Arthroscopy-Assisted Surgery for Tibial Plateau Fractures : 2-to 10-Year Follow-up Results

PURPOSEnThis study evaluated the outcome of arthroscopy-assisted reduction with internal fixation for treating tibial plateau fractures at 2- to 10-year follow-up.nnnMETHODSnFifty-four patients with tibial plateau fractures treated by arthroscopy-assisted reduction with internal fixation were enrolled in this prospective study. According to the Schatzker classification, the fractures types were as follows: type I, 1 (2%); type II, 21 (39%); type III, 4 (7%); type IV, 10 (19%); type V, 8 (15%); and type VI, 10 (19%). The mean age at operation was 48 years (range, 22 to 68 years). The mean follow-up period was 87 months (range, 28 to 128 months). Clinical and radiologic outcomes were scored by the Rasmussen system.nnnRESULTSnThe mean postoperative Rasmussen clinical score was 28.4 (range, 19 to 30), and the mean radiologic score was 16.1 (range, 12 to 18). Good or excellent clinical and radiologic results were achieved in 96% of patients. The 6 fracture types did not significantly differ with regard to Rasmussen score or rate of satisfactory results (P > .05). Secondary osteoarthritis was noted in 10 injured knees (19%). All 54 fractures were successfully united. The mean preoperative fracture depression was 13.7 mm (range, 6 to 25 mm). Fracture depression at the final follow-up averaged 0.3 mm (range, 0 to 4 mm). No complications directly associated with arthroscopy were noted in any of the 54 patients.nnnCONCLUSIONSnArthroscopic surgery for tibial plateau fractures with associated soft-tissue injuries is a safe, reproducible, and effective procedure that provides precise diagnosis and effective treatment in a 1-stage procedure.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Management of small infected tibial defects with antibiotic-impregnated autogenic cancellous bone grafting

Between January of 1991 and December of 1993, 36 patients who had tibia fractures complicated by small infected tibia defects were treated at the authors service. The group included 30 men and 6 women whose average age was 36.5 years (range, 18-72 years). The average follow-up period was 3.7 years. By using the Cierney-Mader staging classification of chronic osteomyelitis, 26 of 36 patients (72%) were stage 4A and 10 of 36 patients (28%) were stage 4B. Ten patients required muscle transfer. All patients were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate bead chains were used to obliterate the debrided osseous defect. In the second stage, the beads were removed, and the defects were reconstructed with antibiotic-impregnated autogenic cancellous bone graft. The time between the first and second stage was 2 to 8 weeks for patients without muscle transfer and 8 to 12 weeks for the patients with muscle transfer. The bone defects ranged from 2 to 4 cm. Wound healing and bony union were achieved in all patients. Only two patients had recurrent infections. The infection arrest rate was 94.4%. Minor pin tract infection of the external skeletal fixation was seen in two patients. Two patients developed skin rashes secondary to antibiotic therapy. Radiographs at an average follow-up of 3.7 years showed good consolidation and hypertrophy of grafted bones in all patients. After 3 to 5 years of follow-up, our results suggest that the use of impregnating antibiotics have no adverse effects on autogenic cancellous bone graft incorporation and may help to eliminate infection. This treatment protocol provided rapid recovery from osteomyelitis. The use of antibiotic-impregnated autogenic bone graft seems to be an effective and safe method for the management of small infected tibial defects.

In Vitro Elution of Antibiotic from Antibiotic-impregnated Biodegradable Calcium Alginate Wound Dressing

OBJECTIVEnThe authors investigated the calcium alginate dressing as a drug-delivery system for the treatment of various surgical infections.nnnMETHODSnCytotoxicity of the calcium alginate dressing to fibroblasts and HeLa cells was evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MITT) colorimetric assay. The calcium alginate dressing was mixed with vancomycin, and lyophilized or not lyophilized to form two types of antibiotic dressings. The antibiotic dressings were placed in 2 mL of phosphate buffered saline (PBS) or in PBS containing 0.01% calcium ions, and incubated at 37 degrees C. The PBS was changed daily, and the removed solutions were stored at -70 degrees C until the antibiotic concentration in each sample was determined by high performance liquid chromatography assay.nnnRESULTSnThe results suggested that the antibiotic dressings present no obvious toxic risk to their use as a drug-delivery system. The concentration of vancomycin in each sample was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial kill. ing and resistance to the antibiotic) for more than 14 days. The release was most marked during the first 48 hours. The concentration of calcium ions in PBS and the lyophilization of the manufacture process of antibiotic dressings prolonged the antibiotic diffusion duration. The diameter of the sample inhibition zone ranged from 10 to 11 mm, and the relative activity of vancomycin ranged from 62.88% to 92.18%.nnnCONCLUSIONnAll antibiotic dressings released bactericidal concentrations of the antibiotics in vitro for the period of time needed to treat surgical infections. This study offers a convenient method to meet the specific antibiotic requirement for different patients.

Arthroscopic Ganglionectomy Through an Intrafocal Cystic Portal for Wrist Ganglia

PURPOSEnA retrospective study was conducted on arthroscopic ganglionectomy in wrists using a novel intrafocal cystic portal. The safety and efficacy of this technique were assessed by treatment of 15 wrists in 15 patients.nnnMETHODSnArthroscopic ganglionectomy was performed by the same surgeon with the patient under general anesthesia or regional block. Preoperative complaints, intraoperative findings, and postoperative results of all the patients were reported. The mean follow-up was 15.3 months. Functional assessment by use of modified Mayo wrist scores, patient satisfaction, and recurrence were included in the follow-up evaluation.nnnRESULTSnTwo thirds of the patients acquired good to excellent results, whereas the results for the remaining third were fair. Complications included 1 recurrence and 1 case of transient paresthesia sensation. The most common arthroscopic findings were capsular and ligament lesions, rather than ganglionic stalks.nnnCONCLUSIONSnArthroscopic ganglionectomy through an intrafocal cystic portal is a safe and efficacious option for the treatment of painful wrist ganglia.nnnLEVEL OF EVIDENCEnLevel IV, therapeutic case series.

Cocktail therapy for femoral head necrosis of the hip

IntroductionCocktail therapy consists of extracorporeal shock wave treatment (ESWT), hyperbaric oxygen therapy (HBO) and alendronate. We hypothesized that this combined therapy may produce better results than ESWT alone when treating hip necrosis.MethodsThis prospective, randomized study evaluated the effectiveness of cocktail therapy in early hip necrosis, and then compared it to shock wave treatment alone. Sixty-three patients (98 hips) were randomly divided into two groups. Group A consisted of 28 patients (50 hips) who received cocktail therapy, and group B consisted of 35 patients (48 hips) who received only ESWT. Each affected hip was treated with 6,000 shocks of ESWT at 28xa0kV (equivalent to 0.62xa0mJ/mm2) in a single session. Cocktail patients also received HBO therapy performed in a multi-place chamber daily for 20 treatments, and they were administered 70xa0mg of alendronate orally per week for 1xa0year. The evaluations included clinical assessment, radiograph and MRI.ResultsAfter a minimum of 2-years of follow-up, the overall results showed 74% improved, 16% unchanged and 10% worsened in group A; and 79.2% improved, 10.4% unchanged and 10.4% worsened in group B (Pxa0=xa00.717). Total hip replacement (THR) was performed for 10% of group A and 10.4% of group B (Pxa0=xa00.946). MRI showed significant reduction in bone marrow edema and a trend of decrease in the size of the lesions in both groups, however, no difference was noted between the two groups. Cocktail therapy is effective for early hip necrosis, but the results are comparable to ESWT in short-term follow up. The joint effects of HBO and alendronate over EWST were not observed.ConclusionLong-term results are needed to determine whether or not the synergistic effects of ESWT, HBO and alendronate over ESWT alone exist in early hip necrosis.

Using Low-Intensity Pulsed Ultrasound to Improve Muscle Healing After Laceration Injury: An in vitro and in vivo Study

The purpose of this study was to determine whether low-intensity pulsed ultrasound (LIPUS) could enhance the regeneration of myofibers and shorten the healing time in injured muscle. NIH C2C12 cells, a well-known myoblastic cell line, are subclones derived from the mouse myoblast cell line established from normal adult C3H mouse leg muscle. The cells differentiate rapidly and produce extensive contracting myotubes expressing characteristic muscle proteins. We exposed C2C12 cells to LIPUS therapy using the EXOGEN 2000+ system ultrasound apparatus (Exogen Inc., Piscataway, NJ, USA) with a total treatment of 20 min every 24 h. At intervals of 2, 4, 6 and 8 days, cell growth was measured by the increase in cell number and western blot analysis of myogenin and actin. Forty mice (C57BL10J+/+) were divided into five groups of eight animals each and used in the published laceration injury model. The gastrocnemius muscle of the left leg was lacerated in all the animals. The control group (sham ultrasound) did not undergo LIPUS therapy. The ultrasound 7-, 14-, 21- and 28-day groups (only changing the number of days during which the ultrasound was applied to the injured muscle) were treated with LIPUS (20 min/day) for 7, 14, 21 and 28 consecutive days, respectively. All animals were sacrificed at 4 weeks after the injury. Evaluation methods included muscle regeneration and muscle contractile properties. LIPUS therapy produced a significantly higher proliferative rate and cell number at days 6 and 8 (p < 0.05). Densitometric evaluation revealed an increase in myogenin and actin proteins in cells treated with LIPUS in the 4-, 6- and 8-day groups. The regeneration of myofibers, fast-twitch and tetanus of LIPUS-treated muscles (21 and 28 days) was significantly greater relative to control muscles. There was no major strength difference between the normal non-injured muscle and the group treated with LIPUS for 28 days. In conclusion, this was the first experimental study to show that LIPUS therapy is able to enhance the regeneration of myofibers with better physiologic performance in injured mice muscles after laceration, especially prior to postoperative week 4. Findings of this study demonstrate a scientific basis for future clinical trials and establish an indication for LIPUS in enhancing muscle healing after laceration injury.

Functional outcomes of arthroscopic posterior cruciate ligament reconstruction: comparison of anteromedial and anterolateral trans-tibia approach

IntroductionThe hypothesis of this study is that anterolateral (A-L) trans-tibia approach is better than anteromedial (A-M) technique in posterior cruciate ligament (PCL) reconstruction. The purpose of this prospective clinical study was to compare the functional outcomes of A-M and A-L trans-tibia approach in arthroscopic PCL reconstruction.Materials and methodsBetween 1999 and 2003, 55 patients (55 knees) with an average age of 30xa0±xa011xa0years (range 16–60xa0years) underwent arthroscopic single-bundle reconstruction for symptomatic isolated PCL tear. Patients were randomly divided into two groups with 28 patients (28 knees) undergoing A-M trans-tibia approach on odd-numbered days, and 27 patients (27 knees) with A-L trans-tibia approach on even-numbered days. Hamstring auto grafts were used in all cases. All patients received the same rehabilitation program postoperatively. The evaluation parameters included clinical assessment, functional outcome, ligament laxity and radiographic changes of the affected knee.ResultsSignificant improvements in pain and function of the knee were observed at an average follow-up of 48xa0±xa015.9xa0months for A-M and 45.0xa0±xa013.7xa0months for A-L approach. However, the difference between the two techniques was statistically not significant. In IKDC for symptom-activity level, normal or nearly normal knees were noted in 68% of A-M and 67% of A-L approach, respectively, but no difference was noted between the two groups. In ligament laxity, approximately two-thirds of the knees showed normal posterior laxity with no difference between the two groups. Radiographs of the knee showed no discernible difference in the overall alignment and degenerative changes as well as the sizes of bone tunnel between the two groups.ConclusionA-M and A-L trans-tibia arthroscopic PCL reconstructions produced comparable clinical results in short-term follow-up. Contrary to our initial hypothesis, the theoretical disadvantages of A-M technique including graft failure were not observed during the follow-up period. Long-term results are needed to confirm the adverse effects of A-M trans-tibia approach in PCL reconstruction.