Effect of a single versus serial platelet-rich plasma injection on the healing of acute patellar tendon defect: an experimental study.

BACKGROUND: There is no consensus on the frequency and timing of platelet-rich plasma (PRP) injection in tendon healing. We aimed to evaluate the effectiveness of single versus multiple PRP injections in the healing of patellar tendon defects in the experimental model, through histological and biomechanical investigation. METHODS: Forty-four male skeletally mature Dutch rabbits were randomly divided into the five study groups ( A, B,C, D,E). After creating a longitudinal acute patellar tendon defect on both knees (One-third the width of the patella tendon), the right legs of the rabbits were used as the intervention group and the left legs as the control groups. Animals in groups A, B, and C were euthanized on days 7, 14, and 28, respectively, after the first PRP injection. Animals in group D received the second PRP injection on day 10 and was euthanized on day 14. Animals in group D received the second and third PRP injections on days 10 and 20, respectively, and were euthanized on day 28. The outcomes were evaluated histologically (modification of Movin's Grading) and biomechanically. RESULTS: The inflammatory condition was exaggerated in groups D and E. Load at failure was higher in the non-injected side of groups D and E, while there was no significant difference between the right and left legs of the three groups A, B and C. In other word, groups with a single PRP injection were more resistant to the increasing load compared to the groups with multiple PRP injections. CONCLUSIONS: PRP improves tendon healing if injected early after injury, while its injection after the initial phase of injury hampers tendon healing. In addition, a single PRP injection seems to be more effective than multiple PRP injection. Therefore, in cases where PRP injection is indicated for tendon repair, such as acute tendon injury, we recommend using a single PRP injection during tendon repair surgery.

Agreement between Sanders classification of intraarticular calcaneal fractures and assessment during the surgery.

BACKGROUND: Sanders classification, based on the number of displaced fractured fragments of posterior facet, can predict the prognosis of calcaneal intraarticular fractures. The aim of the study was assessing not only intraobserver reproducibility and interobserver reliability of Sanders classification but also the agreement between preoperative reported types based on computed tomography (CT) scan and direct observation during the surgery. METHODS: In this cross-sectional study, preoperative CT scans of 100 patients with intra-articular calcaneal fracture operated by a single surgeon were studied by two orthopedic and trauma surgeons (A & B), twice with an interval of three weeks. Their result were compared with each other and with the number of displaced fractured fragments recorded in the operation notes. Quadratic weighted kappa test was used to check the agreement between two observers and between the observers and the surgeon. RESULTS: Intraobserver reproducibility for Sanders classification of intraarticular calcaneal fractures was found to be good to excellent (A1-A2: 0.91 and B1-B2: 0.75). There was a moderate agreement between the two observers (A1-B1: 0.56, A1-B2:0.58, A2-B1:0.48, and A2-B2:0.51). The agreement between reported types of Sanders classification and the number of displaced fractured fragments seen during the surgery was fair (A1-surgeon: 0.27, A2-surgeon: 0.29, B1-surgeon: 0.38, and B2-surgeon: 0.50). CONCLUSIONS: Agreement between Sanders classification and what is real during surgery is fair. Hence, Sanders classification as determined in the widest cut of coronal CT scan extended posteriorly should be cautiously interpreted for surgery.

Arthroscopic anterior cruciate ligament reconstruction with modified "wireless" cross-screw transfix femoral fixation.

Among several graft fixation options in arthroscopic ACL reconstruction for hamstring tendons, transcondylar fixation has been suggested to offer mechanical advantages compared to other femoral fixation systems. Blind nature of the procedure may result in several complications including iliotibial band irritation syndrome, breakage of the bio absorbable cross-pin, stress fracture of the femoral cortex, and more commonly intraoperative wire loop twisting, resulting in fixation failure, wire breakage or graft laceration. We used "wireless" transfixation technique to avoid complications associated with wire loop.

A modification of tibial inlay fixation in posterior cruciate ligament reconstruction by interference screw: a biomedical study on calf tibial bone model.

This study presents a modification of tibial inlay technique in posterior cruciate ligament (PCL) reconstruction and evaluates the structural properties of tibial side fixation of the graft, comparing tibial inlay technique and a new modification, that is interference screw fixation of tibial side of the graft in suggested supine position which is more applicable, with less potential intraoperative neurovascular complications. Forty fresh calf knees that were prepared from 20 healthy 3 years old calves which were between 200 and 220 kg were the subject of this study. The tibias were separately used simulating tibial side PCL reconstruction with tibial tuberosity-patellar tendon-patellar bone graft. Tibial side of the graft was fixed using two cancellous screws in 20 tibiae and with interference screw in obliquely oriented canal in another 20 tibiae. Load-to-failure test was carried out on ten samples from each group. The remaining samples were used for cycling loading. Mann-Whitney U test was used to compare structural properties of each group. No significant differences were observed between two methods at load-to-failure test; but mean elongation at 1,000 cycles of new modification was significantly lower than tibial inlay technique.

Procrastination of wound drainage and malnutrition affect the outcome of joint arthroplasty.

UNLABELLED: The association between wound drainage and subsequent periprosthetic infection is well known. However, the most appropriate treatment of wound drainage is not well understood. We retrospectively reviewed the records of 10,325 patients (11,785 procedures), among whom 300 patients (2.9%) developed persistent (greater than 48 hours postoperatively) wound drainage. Wound drainage stopped spontaneously between 2 and 4 days in 217 patients treated with local wound care and oral antibiotics. The remaining 83 patients (28%) underwent further surgery. A single débridement resulted in cessation of drainage without subsequent infection in 63 of 83 patients (76%), whereas 20 (24%) patients continued to drain and underwent additional treatment (repeat débridement, resection arthroplasty, or long-term antibiotics). Timing of surgery and the presence of malnutrition predicted failure of the first débridement. There were no differences between the success and failure groups with regard to all other examined parameters, including demographic or surgical factors. LEVEL OF EVIDENCE: Level III, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Periprosthetic infection: are current treatment strategies adequate?

Two-staged resection arthroplasty with delayed reimplantation is currently the method of choice for treatment of an infected total hip arthroplasty. There is paucity of data regarding the risk factors for reinfection after reimplantation. The objective of this study was to determine the efficacy of two-stage resection arthroplasty for infected THA and to identify risk factors for reinfection. The outcome of this procedure was evaluated in 54 consecutive patients at our institution from January 1999 to August 2005. The mean follow-up time for patients who were successfully treated was 32 months (range: 24 to 76 months). Infection with methicillin-resistant organisms occurred in 33 patients (61%). Recurrent infection was diagnosed in 14 patients (26%) after the second stage reimplantation procedure at an average of 10.6 months. An elevated ASA, which is an indicator of advanced comorbid health status, and infection with methicillin-resistant organisms were risk factors for treatment failure. An additional 8% of the cohort developed early mechanical failure at a mean of 13.8 months. The increase in the number of resistant organisms and the rise in the number of patients with comorbid conditions have compromised the efficacy of two-stage exchange arthroplasty. Hence novel techniques for the treatment of periprosthetic infection are desperately needed.

The Healing Effect of Bone Marrow-Derived Stem Cells in Knee Osteoarthritis: A Case Report.

Osteoarthritis (OA) is a prevalent chronic disease impacting on quality of life and has societal and economical burden increasing with age. Yet, no confirmed pharmacological, biological or surgical therapy could prevent the progressive destruction of OA joint. Mesenchymal stem cells (MSCs) with immunosuppressive activities emerged a potential therapy. We describe a magnetic resonance images (MRI) approved 47 years old nomad female suffering from a severe right knee OA. After intra-articular injection of 36×10(6) passage 2 of bone marrow-derived stem cells (BMSCs), the patient's functional status of the knee, the number of stairs she could climb, the pain on visual analog scale (VAS) and walking distance improved after two months post-transplantation. MRI revealed an extension of the repaired tissue over subchondral bone. So as MSC transplantation is a simple technique, resulted into pain relief, minimized donor-site morbidity, provided a better quality of life, significantly improved cartilage quality with no need to hospitalization or surgery, cell transplantation can be considered as a reliable alternative treatment for chronic knee OA. Therefore these findings can be added to the literature on using BMSCs for treatment of OA.

Does patellar rim electrocautery have deleterious effects on patellar cartilage?

BACKGROUND: Circumpatellar electrocauterization to destroy pain receptors during total knee arthroplasty without patellar resurfacing is commonly used to decrease postoperative knee pain. We aimed to evaluate the effect of denervation with electrocauterization on patellar cartilage. METHODS: Twenty rabbits were randomly assigned to two equally sized case and control groups. The rabbits in the case group underwent surgery via the anterior midline skin incision and medial parapatellar arthrotomy, followed by denervation electrocauterization at a depth of 1 mm and a distance of 3 mm from the outer border of the patella. In the control group, surgery was identical to that performed in the case group, but without patellar denervation. Twelve weeks after surgery, all rabbits were sacrificed. Range of motion, macroscopic evaluation of cartilage using modified Outerbridge scoring, and histopathological assessment using a modified histologic scoring system for cartilage were evaluated. RESULTS: Three rabbits died during the study. Nine cases and eight animals from the control group were included in the final evaluation. All rabbits had passive full range of motion. Mean Outerbridge score was 2.0 in the case group and 0.37 in the control group (p=0.002). There were statistically significant differences in cellularity (p=0.016), loss of matrix (p=0.004), and clustering of chondrocytes (p=0.008) between the two groups. Microscopic variables as a whole were statistically significant (p=0.001). CONCLUSIONS: Circumpatellar electrocauterization may result in cartilage destruction. So, we encourage caution in using routine electrocauterization in patients undergoing total knee arthroplasty. LEVEL OF EVIDENCE: level II.

A moderate-intensity static magnetic field enhances repair of cartilage damage in rabbits.

BACKGROUND AND AIMS: Electromagnetic fields have been proposed to enhance healing of cartilage defects by stimulation of chondrocyte proliferation, proteoglycan synthesis as well as decreasing pain and improving motion in osteoarthritic patients. However, the effects of a moderate-intensity static magnetic field on cartilage repair have not been investigated. This study tries to determine the effects of a moderate-intensity permanent magnetic field of 40 mT on cartilage repair. METHODS: Defects of 3 mm in diameter and 6 mm in depth were made on the weight bearing surface of the right medial femoral condyle of 30 rabbits. The animals were divided randomly into three equal groups (magnet, sham and control). In the magnet group, cylindrical permanent magnets were implanted subcutaneously medial to the medial femoral condyle, while in the sham group the cylindrical ceramic were not magnetized, and nothing was implanted in controls. After 12 weeks of observation, Mankin's microscopic scoring was done on all specimens, and irregularity of surface characteristics, cell colonization, hypocellularity, cartilage matrix formation, and presence of empty lacunae were investigated. RESULTS: Each of these characteristics showed significant differences in magnet group relative to control and sham groups (p <0.05). Mankin's score was 1.6 ± 0.6 in magnet group, 7.2 ± 1.6 in sham group and 7.7 ± 1 in control group (p <0.001). CONCLUSIONS: [corrected] In this animal study, microscopic Mankin's scoring depicted histological improvement in cartilage of magnet group.

Determining "true" leukocytosis in bloody joint aspiration.

This study intends to determine the diagnostic value of implementing a corrective formula that can adjust for serum leukocytes in bloody joint fluid. Our cohort included 91 infected and 37 aseptic total knee arthroplasties. Joint fluid leukocyte count (>1760/microL) and neutrophil percentage (>73%) were the cutoff values for deep infection. The adjusted fluid leukocyte counts were calculated using the following simple formula: WBCadjusted=WBCobserved-[(WBCblood x RBCfluid/RBCblood)]predicted. Adjusted fluid cell counts of only 5 infected patients dropped below the cutoff value, whereas the remaining 86 maintained a high cell count. Ten noninfected patients had false-positive cell counts, 6 of which were successfully corrected to levels below the designated thresholds. The aspirates that were corrected had a greater number of introduced white blood cells. This study suggests that our corrective formula can detect false-positive joint aspirations without jeopardizing the diagnosis of periprosthetic infection.

Hip pain in young adults: femoroacetabular impingement.

Femoroacetabular impingement is a more recently noticed cause of hip pain in young patients, and early diagnosis and treatment are critical to prevent development of osteoarthritis and/or delay the need for a more radical treatment option such as arthroplasty surgery. Two general types of femoroacetabular impingement have been described. In the cam impingement, the femoral deformity, usually a bump on the head-and-neck junction, impinges on the acetabular rim. The pincer type of impingement is caused by the deformity on the acetabular side, which may be a deep socket, or an acetabular overcoverage due to retroversion that creates an obstacle for flexion and internal rotation. This article attempts to examine the underlying pathogenesis and discusses diagnostic and treatment modalities.

End-to-side neurorrhaphy: an experimental study in rabbits.

The concept of end-to-side nerve repair was recently introduced; however, most authors have reported conflicting results with this technique. This study was conducted to assess the effectiveness of end-to-side nerve repair in both fresh and predegenerated specimens by histological evaluation in an animal study in rabbits. Thirty male rabbits were divided into three groups. In group 1 (n = 14), the peroneal nerve was divided and sutured end-to-side to the tibial nerve via an epineurial window. In group 2 (n = 13), the peroneal nerve was divided and sutured end-to-side to the tibial nerve after a 1-week "predegeneration period." In group 3 (n = 3), which was considered the control group, the peroneal nerve was divided and sutured to the adjacent soft tissues. After 3 months, specimens were harvested for histological evaluation. Nerve fiber count, in normal peroneal nerves, averaged 532/cross section. In groups 1 and 2, average nerve fiber count in implanted peroneal nerves was 6.24 and 7.00/cross section, respectively. No significant statistical difference was observed between fresh and "predegenerated" groups (P = 0.90). These data suggest that collateral sprouting of donor nerves is possible after end-to-side neurorrhaphy through an epineurial window, but the number of nerve fibers in recipient nerves is too low to result in any functional recovery in the target organ.