Hsain Chung Shen

Functional outcomes of surgical reconstruction for posterolateral rotatory instability of the elbow

BACKGROUND The disruption or insufficiency of lateral ligament complex including lateral ulnar collateral ligament (LUCL) leads to posterolateral rotatory instability (PLRI). An accurate clinical staging is quite useful in predicting the prognosis. The purpose of our study is to review our experience with surgical reconstruction for PLRI of the elbow and to investigate the relationship between the clinical stage of elbow instability and the functional outcomes of PLRI. MATERIALS AND METHODS Patients with PLRI of the elbow determined by fluoroscopic stress view under anaesthesia underwent surgical reconstruction of the LUCL with autogenous tendon graft. RESULTS Thirteen of the fourteen patients (93%) were subjectively satisfied with the outcome of the surgery. The mean follow-up was 49 months (range: 24-72). The results were better in patients with stage 1 or 2 instability (group I) compared to those with stage 3 instability (group II). CONCLUSIONS Reconstruction of the LUCL using an autogenous tendon graft is an effective method for patients with PLRI of elbow. Since better results were obtained in patients with stage 1 or 2 instability rather than stage 3, accurate clinical staging determined by fluoroscopic stress view under anaesthesia is important before surgery for appropriate treatment and prediction of functional outcomes.

Arthroscopic Elimination of Monosodium Urate Deposition of the First Metatarsophalangeal Joint Reduces the Recurrence of Gout

PURPOSE To determine if the arthroscopic removal of gouty crystal deposits from the first metatarsophalangeal (MTP) joint will reduce the recurrence rate and improve foot function compared to medical treatment alone. METHODS Twenty-eight male patients with hyperuricemia (>7.0 mg/dL) and repeated attacks of gouty arthritis of the first MTP joint were included in this study. Arthroscopic intervention of the first MTP joint was performed on 15 patients (group 1), while the other 13 patients were treated with medication alone (group 2). The follow-up period (mean +/- standard deviation) was 3.9 +/- 1.1 years in group 1 and 2.4 +/- 0.3 years in group 2. RESULTS After treatment, both groups showed a significant improvement in the number of acute attacks of gouty arthritis and in their functional scores on the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scale. On both measures, the results for group 1 were significantly better than those for group 2. CONCLUSIONS Arthroscopic removal of gouty crystals from the first MTP joint can reduce the rate of acute repeated attacks of gouty arthritis and increase foot and ankle function.

Biomechanical Comparison of Cross-Pin and Endobutton-CL Femoral Fixation of a Flexor Tendon Graft for Anterior Cruciate Ligament Reconstruction-A Porcine Femur-Graft-Tibia Complex Study

BACKGROUND A stable fixation of the graft is imperative for early aggressive rehabilitation after anterior cruciate ligament (ACL) reconstruction. The suspension devices such as Endobutton-CL and Cross-pin system are common techniques of femoral fixation for the hamstring tendon graft and provide superior initial biomechanical properties than the screws system. It remains unclear how such implants perform under cyclic loading and initial pull-out strength. MATERIALS AND METHODS Cross-pin and Endobutton-CL femoral fixation devices were tested for initial fixation strength in porcine knee joints by cyclic loads following a load-to-failure test. The Cross-pin and Endobutton-CL were used for femoral fixation of a porcine profundus flexor digitorum tendon autograft in 20 porcine knees. Ten specimens of femoral-graft-tibia complex in each group were loaded cyclically to between 0 and 150 N at 1 Hz for 1000 cycles following a load-to-failure test at a rate of 150 mm/min. RESULTS The amount of total femur-graft-tibia complex graft displacement was significantly lower in the Cross-pin fixation group (5.37 +/- 0.28 mm) than in Endobutton-CL fixation group (6.08 +/- 0.61 mm: P < 0.05). There were no significant differences in the maximal failure load, yield load, and stiffness between the Cross-pin and Endobutton-CL fixation groups. CONCLUSIONS This biomechanical study reveals that the Endobutton-CL and Cross-pin femoral fixation devices have an equally strong and safe fixation for ACL reconstruction. However, the Cross-pin fixation has significantly less displacement of femur-graft-tibia complex than that of Endobutton-CL fixation in response to the cyclic loading test. It indicates that the Cross-pin fixation is more suitable for early aggressive rehabilitation following ACL reconstruction.

Combined Proximal and Distal Realignment Procedures to Treat the Habitual Dislocation of the Patella in Adults

Background Habitual dislocation of the patella (HDP) is a rare condition. Many surgical procedures using proximal realignment have been reported to treat HDP in children, with around 80% satisfactory results. However, few articles have addressed the treatment of HDP associated with high-grade patellofemoral chondromalacia in adults. Hypothesis A combination of proximal and distal realignment procedures of the patella will reduce pain and increase function in adult patients with HDP. Study Design Case series; Level of evidence, 4. Methods Twelve patients with 13 symptomatic cases of HDP of the knee underwent surgical treatment that included lateral release, medial retinaculum advancement, and the anteromedial tibial tubercle transfer procedure. The average period between dislocation and surgery was 10.8 years. One patient had an additional procedure, an open-wedge varus corrective osteotomy of the distal femur, because of a 20° valgus deformity of the knee. The patellofemoral morphology study included routine and Merchant views of the knee and a computed tomography scan at full extension and at 30° flexion of the knee, before the operation and at follow-up. Any associated intra-articular pathologic findings during the surgical procedure were addressed. Patellofemoral function was evaluated with the Kujala functional score before surgery and at the time of the final follow-up. Results Chondromalacia of the patella over the medial facet and central ridge was grade III in 8 knees and grade IV in 5 knees. Corresponding chondral erosion of the lateral femoral condyle was noted in every knee. All patients were followed for an average period of 67.3 months (range, 25-103 months). The average preoperative Kujala functional score was 43.9 and the average postoperative score was 88.9 (P < .05). Radiographically, there was a statistically significant improvement in the congruence angle from 62.1° ± 15.0° preoperatively to —2.7° ± 9.8° postoperatively (P < .01) and in the lateral patellofemoral angle from —40.2° ± 9.3° preoperatively to 1.4° ± 7.0° postoperatively (P < .01). No patient has reported an episode of patellar dislocation after the surgical procedures. Conclusion Combined proximal and distal realignments of the patella effectively treat HDP in adults with associated high-grade patellofemoral chondromalacia.

Treatment of septic knee arthritis: Comparison of arthroscopic debridement alone or combined with continuous closed irrigation-suction system

BACKGROUND Arthroscopic debridement has been widely adapted as initial treatment for septic knee arthritis. Although isolated cases of arthroscopic debridement combined with irrigation-suction systems have been reported, a comparison of two techniques has not been performed, to our knowledge. The purpose of this study was to compare the two methods of treatment. METHODS From January 1996 to December 2008, 39 patients with 39 septic knee arthritis treated in our institution were retrospectively analyzed. Nineteen knees were initially treated with arthroscopic debridement alone (group I), and 20 knees were initially treated with arthroscopic debridement combined with continuous closed irrigation-suction system (group II). The clinical presentation, laboratory and microbiologic findings, hospital course, and clinical outcomes were compared between the two groups. RESULTS The mean delay between the onset of the symptoms and treatment had a significant effect on the clinical outcomes. When the comparison included all the patients in the series, no significant difference between the two groups was found with regard to the number of operation procedures required or the length of the hospital stay. However, when the comparison was separated from the initial stage of infection, it was found that in stage II infection, patients had fewer reoperations and in stages II and III infection, a shorter hospital stay in group II than in group I (p < 0.05). There was no significant difference in the functional results between the two groups. CONCLUSIONS The early diagnosis and aggressive initiation of treatment carried the success of therapy in septic knee arthritis. Arthroscopic debridement combined with continuous closed irrigation-suction system is an effective treatment for patients with septic knee arthritis; these patients had fewer operations and a shorter hospital stay than did patients who had received arthroscopic debridement alone.

Mechanical comparison of biodegradable femoral fixation devices for hamstring tendon graft - A biomechanical study in a porcine model

BACKGROUND Initial fixation strength is critical for the early post-operative rehabilitation of patients with anterior cruciate ligament reconstructions. However, even the best femoral fixation devices remain controversial. We compared the biomechanical characteristics of tendon grafts fixed by different biodegradable femoral fixation devices following anterior cruciate ligament reconstruction. METHODS The Bio-TransFix, Rigidfix, Bioscrew with EndoPearl augmentation and Bioscrew devices were used to fix porcine flexor digitorum profundus tendon grafts in 32 porcine femora. Displacement of each tendon graft was evaluated after cyclic loading testing. Stiffness, ultimate failure load and failure mode of these fixation devices were measured with load-to-failure testing. FINDINGS The displacement of the femur-graft-cement complex in response to cyclic loading was lower (P<0.05) for the Bio-TransFix than the Rigidfix, Bioscrew with EndoPearl augmentation, and Bioscrew groups. The fixation stiffness values of the Rigidfix and the Bioscrew were significantly greater (P<0.05) than that of the Bio-TransFix. The ultimate failure load was significantly greater for the Bio-TransFix and the Rigidfix than the Bioscrew with EndoPearl augmentation or the Bioscrew (P<0.05). INTERPRETATION The Bio-TransFix provided the least graft displacement under cyclic loading. However, this device gave less stability. The Rigidfix device provided better stability and stiffness of the tendon graft among those fixation devices that showed no significant differences in graft displacement under cyclic loading. However, no single fixation device provided less displacement along with a larger failure load and stiffness in this study.

Comparison of Different Sizes of Bioabsorbable Interference Screws for Anterior Cruciate Ligament Reconstruction Using Bioabsorbable Bead Augmentation in a Porcine Model

PURPOSE The aim of this study was to compare the initial fixation strength of tendon grafts between different sizes of bioabsorbable interference screws (BioScrew; Linvatec, Largo, FL) with bioabsorbable bead (EndoPearl; Linvatec) augmentation through biomechanical analysis of a porcine femoral bone model. METHODS Forty pairs of porcine femurs and porcine flexor digitorum profundus tendons were divided into control and study groups. In the control group 8 x 30-mm BioScrews alone (n = 10) were inserted, whereas different sizes of BioScrews, measuring 7 x 30 mm (n = 10), 8 x 30 mm (n = 10), and 9 x 30 mm (n = 10), with 8-mm EndoPearl augmentation were inserted individually for fixation of tendon grafts in the study groups. All specimens were cyclically loaded with axial forces between 50 and 250 N at 1 Hz for 3,000 cycles and then incrementally loaded to failure at a rate of 150 mm/min. RESULTS BioScrews with EndoPearl augmentation had a significantly higher failure load than BioScrews alone (8-mm BioScrew alone v 8-mm BioScrew and EndoPearl, P < .05). There were no significant differences in the ultimate failure load (8 mm v 7 mm and 9 mm, P = .201 and P = .871, respectively), stiffness (8 mm v 7 mm and 9 mm, P = .789 and P = .823, respectively), displacement (8 mm v 7 mm and 9 mm, P = .695 and P = .781, respectively), and bone mineral density (P = .728 for all comparisons) except insertion torque (8 mm v 7 mm and 9 mm, P = .045 and P = .518, respectively) between study groups. Less tendon laceration by the screw thread was noted in the group in which smaller-sized BioScrews were used. CONCLUSIONS When EndoPearl augmentation was used, smaller-sized BioScrews (BioScrew size 1 mm smaller than bone tunnel) offered equivalent graft fixation strength to BioScrews of similar or larger sizes. CLINICAL RELEVANCE Smaller-sized BioScrews can be chosen if EndoPearl augmentation has been used, and EndoPearl augmentation may reduce the risk of tendon rupture while BioScrews are inserted.

Nonconcentric reduction by an inverted anterosuperior labrum with avulsed osteocartilaginous fragment in an anterior hip dislocation.

A 26-year-old man was involved in a motorcycle accident and presented with an anterior hip dislocation. After a closed reduction, the hip showed a nonconcentric reduction. With an open reduction, an inverted anterosuperior labrum with avulsed osteocartilage was found, which prohibited the concentric reduction of the hip joint. The inverted labrum, cartilage, and torn ligamentum teres were excised, the femoral head was reduced, and the capsule was reapproximated. Six months after surgery, the patient still complained of slight pain in the left hip, with 20- to 30-degree restriction of hip flexion relative to that of the normal side. A radiograph of the hip was normal.

Parameniscal cyst formation in the knee is associated with meniscal tear size: An MRI study

BACKGROUND The relationship between meniscal tears and parameniscal cyst formation is contentious. We investigated whether the development of a parameniscal cyst is related to the size of the meniscal tear by using magnetic resonance imaging (MRI). METHODS On the basis of a retrospective review of an MRI database, we identified parameniscal cysts in 34 patients with adjacent meniscal tears extending to the meniscocapsular junction. The size of the meniscal tear was measured by dividing the length of the tear along two axes: circumferential and radial. We compared parameters, such as the size of the meniscal tear, the location of the tear, the pattern of each tear, and any associated ligamentous injury and intra-articular lesion, between the 34 patients and the 30 control patients who only had meniscal tears with torn components extending to the meniscocapsular junction. RESULTS Compared with the controls, patients with parameniscal cysts had significantly larger meniscal tears along the circumferential axis (P<0.001). A critical size of the meniscal tear along the circumferential axis of 12mm was associated with the formation of a parameniscal cyst. CONCLUSIONS A larger meniscal tear extending into the meniscocapsular junction is more likely to be associated with the occurrence of a parameniscal cyst. The critical size of the meniscal tear, 12mm along the circumferential axis as identified using MRI, is a discrimination value for parameniscal cyst formation. LEVEL OF EVIDENCE Level III.

Arthroscopic Excision of Ganglion Cysts of the Posterior Cruciate Ligaments Using Posterior Trans-Septal Portal

PURPOSE To evaluate clinical outcomes of arthroscopic excision of ganglion cysts involving the posterior cruciate ligament (PCL) using the posterior trans-septal portal in the knee. METHODS A retrospective study was performed of 15 cases of ganglion cyst involving the PCL treated at our institution over a period of 4 years. All the cysts were diagnosed and had their location confirmed preoperatively by magnetic resonance imaging (MRI). All the cysts were excised arthroscopically through the posterior trans-septal portal. All patients were followed up with MRI evaluation at a mean of 36 months after surgery. In addition, International Knee Documentation Committee (IKDC) scores and range of motion (ROM) were obtained preoperatively and postoperatively simultaneously with MRI to assess the surgical outcomes. RESULTS Most of the patients were male patients, and the mean age was 32 years. The most common presenting complaint was pain and difficulty in knee flexion. Preoperatively, the mean ROM was 3° to 110° and the mean IKDC score was 53 (range, 38 to 67; SD, 7.9). The location of the main cystic component was posterior to the PCL in 14 patients (93%) and anterior to the PCL in 1 patient (7%). After surgery, MRI evaluation at a mean follow-up time of 36 months showed no cyst recurrence. Postoperatively, the mean IKDC score was 91 (range, 70 to 99; SD, 9.3) and the mean ROM was 3° to 128°. CONCLUSIONS Ganglion cysts associated with the PCL can cause knee pain and limitation of knee flexion. MRI evaluation is a noninvasive method of diagnosing PCL ganglion cysts. Arthroscopic excision through the posterior trans-septal portal is a good option for relieving pain and preventing cyst recurrence. LEVEL OF EVIDENCE Level IV, therapeutic case series.