Enhancement of rotator cuff tendon-bone healing with injectable periosteum progenitor cells-BMP-2 hydrogel in vivo.

PURPOSE: The fixation and incorporation of ruptured rotator cuff tendon to bone is a major concern in rotator cuff repair surgery. Rotator cuff repair usually fails at the tendon-bone interface, especially in case of large or massive tears. To enhance tendon-bone healing, an injectable hydrogel made with periosteal progenitor cells(PPCs) and poly (ethylene glycol) diacrylate (PEGDA) tethered with bone morphogenic protein-2(BMP-2) was developed to encourage extracellular matrix synthesis for tendon-to-bone healing in rotator cuff repair. METHODS: The infraspinatus tendon was cut from the greater tuberosity and repaired through a transosseous tunnel with the injectable progenitor cell-BMP-2 hydrogel applied between the tendon-bone interface. The injectable hydrogel was prepared from 10% poly (ethylene glycol) diacrylate (PEGDA) containing 0.05% of the photoinitiator. BMP-2 tethered with poly(ethylene glycol) (PEG) was blended to the hydrogel. Rabbit periosteal progenitor cells (PPCs) isolated from periosteum were mixed with hydrogel and injected on the tendon-bone interface. Ultraviolet radiation (365 nm) was applied for 60 s to photopolymerize the injection and solidify the hydrogel. The rabbits were killed at 4 and 8 weeks. The morphological characteristics of the healing tendon-to-bone interface were evaluated by histological and immunohistochemical methods. The biomechanical test was done to determine healing attachment strength. RESULTS: At both the 4- and 8-week killing, histological analysis of the tendon-bone interface showed an increasing fibrocartilage and bone layer formed in the tendon-bone interface in PEGDA group. At 4 weeks, fibrocartilage-like tissue was observed in a focal area. At 8 weeks, further matrix deposition occurred with fibrocartilage formation in the tendon-bone junction, and bone formation appeared near host bone. Immunohistochemistry revealed the presence of aggrecan and type II collagen. Biomechanical testing revealed a higher maximum pull-out load at all time points with a statistically significant difference at 4 and 8 weeks postoperatively. CONCLUSION: PEGDA hydrogel was approved as an adequate matrix for the encapsulation of cells and signal factor, and as an effective local delivery method to the tendon-bone interface through injection and photopolymerization. The PPCs-BMP2-hydrogel provides a powerful inductive ability between the tendon and the bone and enhances tendon-bone healing through the neoformation of fibrocartilage.

Arthroscopic single-bundle anterior cruciate ligament reconstruction with periosteum-enveloping hamstring tendon graft: clinical outcome at 2 to 7 years.

PURPOSE: In this case-series outcome study, we present our surgical technique for single-bundle anterior cruciate ligament (ACL) reconstruction with periosteum-enveloping hamstring tendon graft at a minimum of 2 years' follow-up. METHODS: From 2000 to 2005, ACL reconstruction with a periosteum-enveloping hamstring tendon graft was performed in 368 patients (372 knees). Of those patients, 312 who completed at least 2 years of follow-up were included for analysis. Four-strand periosteum-enveloping hamstring tendon grafts were used for single-bundle reconstruction. Clinical assessments included the Lysholm knee score, International Knee Documentation Committee score, KT-1000 instrumented testing (MEDmetric, San Diego, CA), thigh muscle assessment, and radiographic evaluation. Radiographs were used to assess femoral and tibial tunnel widening. RESULTS: The 312 study patients were followed up for a mean of 4.6 years (range, 2 to 7 years). The median Lysholm knee scores were 56 points (range, 40 to 70 points) and 95 points (range, 60 to 100 points) before and after surgery, respectively. After reconstruction, 85% of patients could return to moderate or strenuous activity, 5.1% exhibited grade 2 or higher ligament laxity with the anterior drawer test, and 6.1% had a positive pivot shift. Complete range of motion was achieved in 88% of patients. On the basis of International Knee Documentation Committee assessment, 93% of patients had a normal or nearly normal rating. CONCLUSIONS: Satisfactory results can be achieved with the periosteum-enveloping hamstring tendon graft in single-bundle ACL reconstruction with minimal tunnel widening. Bone tunnel enlargement of more than 1 mm was identified in 5.4% of femoral tunnels and 6.1% of tibial tunnels, which was less than in other studies using comparable fixation. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Effect of magnetic knee wrap on quadriceps strength in patients with symptomatic knee osteoarthritis.

OBJECTIVE: To determine the effects of magnetic knee wrap on isokinetic quadriceps strength in patients with painful knee osteoarthritis (OA). DESIGN: Randomized, double-blinded, placebo-controlled and before-after trial. SETTING: Rehabilitation clinic in a tertiary hospital. PARTICIPANTS: Eligible patients (N=50) (mean age+/-SD, 66.0+/-8.6 y) with mild to moderate knee OA were recruited from the outpatient department and 37 (74%) completed the trial. Only 3 (6%) withdrew due to study-related adverse effects. INTERVENTIONS: Wearing the active (n=24) or sham (n=26) magnetic knee wrap for 12 weeks. MAIN OUTCOME MEASURES: The primary outcome measure was isokinetic quadriceps strength. Secondary outcome measures included the Health Assessment Questionnaire Disability Index (HAQ-DI) and the Health Assessment Questionnaire (HAQ) Pain Scale. RESULTS: Using intention-to-treat analyses, the peak isokinetic quadriceps strength increased significantly in the treated leg at 30 degrees/s (P=.007) and 60 degrees/s (P=.022) after wearing the magnetic knee wrap. Compared with baseline, the median strength increase for the treated leg in the study group significantly exceeded that in the control group at week 4 (.05 Nm/kg vs -.09 Nm/kg at 60 degrees/s, P=.038) and week 12 (30 degrees/s, .09 Nm/kg vs .04 Nm/kg, P=.044; 60 degrees/s, .17 Nm/kg vs .02 Nm/kg, P=.031). The HAQ-DI and HAQ Pain Scales improved significantly in both groups. Compared with baseline, the improvement at week 12 in terms of the HAQ-DI in the study group significantly exceeded that in the control group. CONCLUSIONS: Magnetic knee wrap may significantly facilitate isokinetic quadriceps strength in patients with mild to moderate knee OA.

Classification and analysis of pathology of the long head of the biceps tendon in complete rotator cuff tears.

BACKGROUND: Pathology of the long head of the biceps tendon (LHB) is commonly associated with rotator cuff tears (RCTs). Superior labral anterior-posterior (SLAP) lesions can also occur with RCTs. The purpose of this study was to include SLAP lesions as part of LHB pathology in surgical cases of RCT and define the role of SLAP lesions in RCTs. METHODS: We retrospectively evaluated clinical data from 176 cases of complete RCT undergoing surgery. During surgery, the LHB was arthroscopically examined. A modified 6-type classification was used to describe the LHB pathology in these cases: tendinitis, subluxation, dislocation, partial tear, complete rupture and SLAP lesions. The relationship of LHB pathology to different characteristics of RCTs was statistically analyzed. RESULTS: Of RCT cases, 33% had Type 1 (tendinitis), 11% had Type 2 (subluxation), 9% had Type 3 (dislocation), 16% had Type 4 (partial tear), 7% had Type 5 (complete rupture) and 6% had Type 6 (SLAP) lesions. The remaining 18% of cases had no obvious LHB pathology. LHB pathology were associated with RCTs of a long duration (> 3 months), large area (> 5 cm(2)), and multiple or subscapularis tendon involvement. Seventy four percent of patients with affected shoulders underwent simultaneous surgery for both LHB pathology and RCTs. CONCLUSION: Most patient with RCTs with chronic, massive, and multiple or subscapularis tendon involvement also had LHB injury. SLAP lesions, which we classified as a subgroup of LHB pathology, should be identified during rotator cuff surgery and treated appropriately.

Subacromial injections of corticosteroids and xylocaine for painful subacromial impingement syndrome.

BACKGROUND: Subacromial impingement syndrome, with pain and limited motion, is a common disease encountered daily in clinics. This study determined the efficacy of subacromial injections of corticosteroids and local anesthesia for treatment of painful subacromial impingement syndrome. METHODS: A total of 238 shoulders in 209 patients, with regular follow-up, were enrolled in this study. Mean patient age was 51 years (range 31-72 years). Each patient complained of shoulder pain with progressive motion limitation present for more than one month, which was not relieved by various nonsurgical treatments. The mean duration of symptoms before injection was five months (range 1-12 months). Each patient had a positive Neer impingement sign, Hawkins impingement sign, painful tendon sign, limited range of motion and did not show clinical evidence of a rotator cuff tear. Each patient was administered an injection of 1 ml of 2% Xylocaine and 1 ml of Rinderon suspension. A second injection was administered one week later for patients without obvious improvement. Following injections, patients were instructed to perform a home rehabilitation program for four weeks. Follow-up examinations were scheduled for one, two and four weeks, and three, six, nine and 12 months after injection. Outcome measures included the Constant-Murley score and shoulder range of motion. RESULTS: At follow-up four weeks after the first injection, 216 shoulders (91%) had satisfactory improvement in amount of pain and range of motion: mean improvements in the active range of motion of forward elevation, abduction, internal rotation and external rotation were 56 degrees, 48 degrees, 18 degrees and 22 degrees, respectively. However, at the first year follow-up, the satisfaction rate was slightly down at 88%, and 19 shoulders (8%; 16 patients) had recurrent pain and motion limitation after an average of 5.4 months (range 3-12 months). Each of these patients received another injection. Surgery was recommended for 22 shoulders (9%; 18 patients) that did not have satisfactory improvement. Of these patients, eight shoulders (seven patients) had a partial tear of the rotator cuff and 10 shoulders (eight patients) had complete rotator cuff tears. CONCLUSION: Subacromial injection of corticosteroids and local anesthesia is an effective therapy for the treatment of symptomatic subacromial pathology, such as impingement pain, tendonitis and bursitis. The injection can substantially reduce pain and increase range of motion of the shoulder. If there is no improvement following injections, a rotator cuff tear should be suspected.

Treatment of volar Barton's fractures: comparison between two common surgical techniques.

BACKGROUND: Volar Barton's fractures are not uncommon but more convincing treatment methods are still controversial. Currently, open reduction with buttress plating or closed reduction with external fixation and percutaneous Kirschner wire fixation have achieved most support. METHODS: Twenty-three consecutive volar Barton's fractures treated with either open reduction and buttress plate fixation (12 cases) or closed reduction with external fixation and percutaneous Kirschner wire fixation (11 cases) were compared retrospectively. The fractures were followed-up for a mean of 30 months (range, 24-50 months). RESULTS: All 23 fractures healed without major complications. The wrist function was satisfactory in all plating patients (12 out of 12) and nine out of 11 external fixation patients (p = 0.22). CONCLUSION: Both the above mentioned surgical techniques give a high success rate. Despite the fact that each technique has advantages and disadvantages, the results from the plating treatment seem to be superior.

Closed femoral nailing in lateral decubitus position without a fracture table: a preliminary report of fifteen patients.

BACKGROUND: The use of a fracture table is standard for closed intramedullary nailing of femoral fractures. Instead of a fracture table, some clinicians have successfully performed this operation in the supine position via manual traction. Here, we present our experience performing this operation in the lateral decubitus position without a fracture table. METHODS: From December 2001 to November 2002, we consecutively performed closed intramedullary femoral nailing in 15 patients with low comminuted femoral shaft fractures in the lateral decubitus position without a fracture table. We used manual or joystick traction to approximate the fracture fragments and introduced a guide pin. A reaming procedure was done with serial reamers of increasing diameters to reduce the fracture fragments. Then, the nail was inserted along the guide pin. RESULTS: Six femora underwent Küntscher nailing and nine femora underwent interlocking nailing. Nine procedures were completed via joystick traction and six were completed via manual traction only. All fifteen procedures were completed without any changes in the other operative methods. The mean operation time was 55 minutes for Küntscher nailing and 118.3 minutes for interlocking nailing. The average union time was 5.8 months with 100% union. CONCLUSIONS: For low comminuted femoral shaft fractures, using manual or joystick traction in the lateral decubitus position without a fracture table is an alternative in closed femoral intramedullary nailing.