Seung Baik Kang

Does Platelet-Rich Plasma Accelerate Recovery After Rotator Cuff Repair? A Prospective Cohort Study

Background: Platelet-rich plasma (PRP) has been recently used to enhance and accelerate the healing of musculoskeletal injuries and diseases, but evidence is still lacking, especially on its effects after rotator cuff repair. Hypothesis: Platelet-rich plasma accelerates recovery after arthroscopic rotator cuff repair in pain relief, functional outcome, overall satisfaction, and enhanced structural integrity of repaired tendon. Study Design: Cohort study; Level of evidence, 2. Methods: Forty-two patients with full-thickness rotator cuff tears were included. Patients were informed about the use of PRP before surgery and decided themselves whether to have PRP placed at the time of surgery. Nineteen patients underwent arthroscopic rotator cuff repair with PRP and 23 without. Platelet-rich plasma was prepared via plateletpheresis and applied in the form of a gel threaded to a suture and placed at the interface between tendon and bone. Outcomes were assessed preoperatively and at 3, 6, 12, and finally at a minimum of 16 months after surgery (at an average of 19.7 ± 1.9 months) with respect to pain, range of motion, strength, and overall satisfaction, and with respect to functional scores as determined using the following scoring systems: the American Shoulder and Elbow Surgeon (ASES) system, the Constant system, the University of California at Los Angeles (UCLA) system, the Disabilities of the Arm, Shoulder and Hand (DASH) system, the Simple Shoulder Test (SST) system, and the Shoulder Pain and Disability Index (SPADI) system. At a minimum of 9 months after surgery, repaired tendon structural integrities were assessed by magnetic resonance imaging. Results: Platelet-rich plasma gel application to arthroscopic rotator cuff repairs did not accelerate recovery with respect to pain, range of motion, strength, functional scores, or overall satisfaction as compared with conventional repair at any time point. Whereas magnetic resonance imaging demonstrated a retear rate of 26.7% in the PRP group and 41.2% in the conventional group, there was no statistical significance between the groups (P = .388). Conclusion: The results suggest that PRP application during arthroscopic rotator cuff repair did not clearly demonstrate accelerated recovery clinically or anatomically except for an improvement in internal rotation. Nevertheless, as the study may have been underpowered to detect clinically important differences in the structural integrity, additional investigations, including the optimization of PRP preparation and a larger randomized study powered for healing rate, are necessary to further determine the effect of PRP.

High incidence of loosening of the femoral component in legacy posterior stabilised-flex total knee replacement

We have examined the results obtained with 72 NexGen legacy posterior stabilised-flex fixed total knee replacements in 47 patients implanted by a single surgeon between March 2003 and September 2004. Aseptic loosening of the femoral component was found in 27 (38%) of the replacements at a mean follow-up of 32 months (30 to 48) and 15 knees (21%) required revision at a mean of 23 months (11 to 45). We compared the radiologically-loose and revised knees with those which had remained well-fixed to identify the factors which had contributed to this high rate of aseptic loosening. Post-operatively, the mean maximum flexion was 136 degrees (110 degrees to 140 degrees) in the loosened group and 125 degrees (95 degrees to 140 degrees) in the well-fixed group (independent t-test, p = 0.022). Squatting, kneeling, or sitting cross-legged could be achieved by 23 (85%) of the loosened knees, but only 22 (49%) of the well-fixed knees (chi-squared test, p = 0.001). The loosened femoral components were found to migrate into a more flexed position, but no migration was detected in the well-fixed group. These implants allowed a high degree of flexion, but showed a marked rate of early loosening of the femoral component, which was associated with weight-bearing in maximum flexion.

The natural history of pediatric trigger thumb.

BACKGROUND Pediatric trigger thumb is a condition of flexion deformity of the interphalangeal joint in children. Although the surgical outcome is satisfactory, the indications for nonoperative treatment for this condition are not clear. The aim of the present study was to determine the rate of resolution of untreated pediatric trigger thumb. METHODS Data on seventy-one thumbs in fifty-three children were collected prospectively. The dates of the first visits ranged from April 1994 to March 2004. Patients were diagnosed with pediatric trigger thumb during initial outpatient department visits. During the present study, no treatment such as passive stretching or splinting was applied. The amount of flexion deformity at the thumb interphalangeal joint was measured at every six-month follow-up visit, and the duration of follow-up was at least two years after diagnosis. The end point of follow-up was when the deformity caused pain or secondary deformity or prevented normal use of the hand. The median duration of follow-up was forty-eight months. RESULTS Of the seventy-one trigger thumbs, forty-five (63%) resolved spontaneously. The median time from the initial visit to resolution was forty-eight months. There was no significant difference in the pattern of resolution between patients with unilateral and bilateral trigger thumb. Although resolution was not observed in the remaining twenty-six thumbs, flexion deformities improved in twenty-two thumbs. For the first two years after the initial visit, the mean flexion deformity significantly decreased over the one-year intervals (p < 0.05). CONCLUSIONS Pediatric trigger thumb can be expected to resolve without treatment in >60% of patients. Moreover, the flexion deformity can be expected to show an improving pattern in patients who do not have resolution. This information may help both parents and surgeons to make decisions regarding the treatment of pediatric trigger thumb.

A Randomized Clinical Trial of Cementless Femoral Stems With and Without Hydroxyapatite/Tricalcium-Phosphate Coating. An 8- to 12-Year Follow-Up Study

To evaluate the effect of hydroxyapatite coating on cementless femoral stem, a prospective randomized clinical trial was conducted. A total of 84 hips from 69 patients were assigned to a hydroxyapatite/tricalcium-phosphate-coated group or a noncoated group. Thirty-two patients (37 hips) who received hydroxyapatite/tricalcium-phosphate-coated stems and 31 patients (38 hips) who received noncoated stems were followed for an average of 127 months. Forty-nine patients (78%) were men, and the average age was 45.5 years. Preoperative diagnosis was osteonecrosis in 62 hips (83%). The mean Harris hip score at the time of final follow-up was 91 points in the coated group and 90 points in the noncoated group. Six acetabular components (3 in each group) were revised. One femoral stem in the noncoated group was loose. There was no statistical difference in the survival distributions of the implants between the 2 groups.

A Randomized Clinical Trial of Cementless Femoral Stems With and Without Hydroxyapatite/Tricalcium-Phosphate Coating

Abstract To evaluate the effect of hydroxyapatite coating on cementless femoral stem, a prospective randomized clinical trial was conducted. A total of 84 hips from 69 patients were assigned to a hydroxyapatite/tricalcium-phosphate–coated group or a noncoated group. Thirty-two patients (37 hips) who received hydroxyapatite/tricalcium-phosphate–coated stems and 31 patients (38 hips) who received noncoated stems were followed for an average of 127 months. Forty-nine patients (78%) were men, and the average age was 45.5 years. Preoperative diagnosis was osteonecrosis in 62 hips (83%). The mean Harris hip score at the time of final follow-up was 91 points in the coated group and 90 points in the noncoated group. Six acetabular components (3 in each group) were revised. One femoral stem in the noncoated group was loose. There was no statistical difference in the survival distributions of the implants between the 2 groups.

Under-meniscal portal: an alternative portal for an easy access to the medial and lateral menisci

Approach to the pathologies in the posterior horn of the medial meniscus in a tight knee may be a challenging technique to the arthroscopic surgeon in certain patients. The pie-crusting technique of the medial collateral ligament which can be done percutaneously to open up a tight posteromedial compartment would be a good option in such patients. Here, the authors introduce a useful alternative portal for approaching the posterior horn of the medial meniscus, the under-meniscal portal. The under-meniscal portal is located under the menisci and can be placed safely and easily without any complication. It is also helpful for approaching the unstable underside of the horizontal tear in the anterior horn of the lateral meniscus. The authors suggest the under-meniscal portal as a good alternative portal for managing challenging lesions in the posterior horn of the medial meniscus and the anterior horn of the lateral meniscus.

Clinical Application of TiNi Shape Memory Alloy Bone Fastener

Titanium-Nickel shape memory alloy (TiNi SMA) has great potential as a biomaterial in orthopaedic applications due to its unique thermal shape memory effects, superelasticity and high damping properties. We designed and manufactured bone fasteners using newly developed TiNi SMA wire (Af, 35 2.C). Several types of bone fastener designs were prepared for the application of orthopedic treatment of bone fracture. We applied this fastener to 82 fracture patients. Fracture types according to the anatomic location included distal fibular (21), femur shaft (periprosthetic fracture, 17), distal tibia (15), distal femur (10), metacarpal bone (9), and subtrochanter of femur (5), distal clavicle (5). Serial radiographs, complete blood count (CBC) and urine analysis were performed postoperatively. Radiological union was achieved without complications at due time after operation. There were no abnormal findings on follow-up CBC or urine analysis. On a subjective level, use and application of the TiNi SMA fastener was not as demanding as conventional fixation methods, such as circumferential wiring (cerclage) or the Dall-Miles technique. The efficacy of SMA bone fastener in this study is very excellent as demonstrated in this clinical study. It gives the new armament to orthopedic surgeon.