Junsuke Nakase

Outcomes and failure factors in surgical treatment for osteochondritis dissecans of the capitellum

Background: Osteochondritis dissecans (OCD) of the capitellum is an intra-articular lesion and one of the leading causes of permanent elbow disability. The treatment of advanced capitellar OCD remains challenging because of the limited potential of the articular cartilage for self-repair. The purpose of this study was to investigate the outcome of surgical treatment for OCD of the capitellum. Methods: From 2000 to 2010, 32 male patients who had advanced lesions of capitellar OCD were treated operatively. The mean age of the patients was 14.4 years at the time of surgery. Twenty-nine patients played baseball and 3 played other sports. The lesions were of the centralized type in 9 patients, the lateral type in 4 patients, and the widespread type in 19 patients. For the surgical procedure, osteochondral peg fixation was selected for 13 patients and osteochondral autograft transplantation for 19 patients. Clinical outcome was measured with the elbow rating system including range of motion, and the number of patients who returned to active sports participation within 1 year after surgery was determined. Results: The mean total arc of elbow motion increased from 123±17 degrees preoperatively to 132±14 degrees postoperatively. The mean clinical score improved significantly from 133±24 to 177±27. Within the first year after surgery, 81.3% of the patients returned to active sports playing. However, 4 of 8 patients (50%) in which osteochondral peg fixation was performed for lesions of the lateral widespread type required reoperation. Conclusions: Our results indicate that osteochondral peg fixation and osteochondral autograft transplantation may improve elbow rating score, and may facilitate a return to active sports participation. However, osteochondral peg fixation may be insufficient for lesions of the widespread type because of their poor stability. The large lateral condyle lesions had a worse outcome, and future studies will need to develop improved treatment for these defects. Level of Evidence: Level IV (case series).

Facilitated Tendon-Bone Healing by Local Delivery of Recombinant Hepatocyte Growth Factor in Rabbits

PURPOSE This study was performed to evaluate the therapeutic effect of hepatocyte growth factor (HGF) on tendon-bone healing in a rabbit model. METHODS In adult rabbits the long digital extensor tendon was detached from the lateral femoral condyle, and the free end of the tendon was inserted into a tunnel drilled into the proximal tibial metaphysis. Cancellous bone obtained during drilling of the tibial hole was soaked in saline solution or solution containing 100-microg/mL human recombinant HGF and then transplanted into the bone tunnel. Junctional healing between the tendon and the bone was evaluated by histologic analysis and uniaxial load-to-failure testing at 2, 4, 6, 8, and 12 weeks after surgery. RESULTS In the saline solution-treated control group, Sharpey-like fibers, which connected the tendon graft and the bone tissue, appeared 6 weeks after treatment. At 8 weeks after treatment, maturation of lamellar bone was seen, and at 12 weeks, the adhesion between tendon and bone appeared to be supported by indirect insertion of fibrocartilaginous tissue, wherein the border between the fibrocartilaginous tissue and tendon or bone was significant. In the HGF-treated group, the fibrous tissues were parallel to the load axis, and lamellar bone and Sharpey-like fibers appeared as early as 4 weeks after treatment. At 12 weeks, junctional tissue, characterized by a continuous 4-layer structure of bone, calcified cartilage, fibrocartilage, and tendon, was regenerated by a direct insertion. On biomechanical testing, the HGF-treated group had significantly better biomechanical properties than the control group at 2 and 4 weeks. The histologic improvement caused by HGF treatment was associated with the biomechanical improvement. CONCLUSIONS Local administration of recombinant HGF promotes the adhesive healing process at the tendon-bone junction, both histologically and mechanically, after ligament reconstruction in a rabbit model. CLINICAL RELEVANCE Application of HGF may be considered as a new therapeutic approach to accelerate healing and rehabilitation after ligament reconstruction.

Ultrasonography imaging of the anterolateral ligament using real-time virtual sonography.

BACKGROUND The anterolateral ligament (ALL) functions as a stabilizer in the internal rotation of the knee. Previous studies have reported the ALL can be identified using magnetic resonance imaging (MRI); however, there are no reports on using ultrasonography (US) for this purpose. Real-time virtual sonography (RVS) uses magnetic navigation and computer software for the synchronized display of real-time US and multiplanar reconstruction MRI images. This study investigated the ability of using US with RVS to evaluate the ALL. METHODS Nine healthy subjects were enrolled. The Digital Imaging Communications in Medicine MRI dataset was loaded into the Hitachi Aloka Preirus, and US images were displayed on the same monitor. When the ALL was identified using MRI, the monitor was frozen to evaluate the ALL. The ALL was divided into the femoral, meniscal, and tibial portions. The portions and thickness of the ALLs and the lateral inferior genicular artery (LIGA), a landmark for the ALL, were evaluated. RESULTS All portions of the ALL could be identified using MRI. Using US, the tibial portion of the ALL was detected in all subjects and the femoral portion was detected in seven subjects; however, the meniscal portions could not be identified. The average ALL thickness as measured by US was 1.3±0.1 mm and the LIGA was identified in all cases. CONCLUSIONS Most portions of the ALL can be identified using US. As most ALL injuries occur at the femoral or tibial portion, US may be useful as a diagnostic tool for ALL injury. LEVEL OF EVIDENCE 4.

Roles of ACL remnants in knee stability

PurposeThis study evaluated knee laxity in anterior tibial translation and rotation following removal of anterior cruciate ligament (ACL) remnants using a computer navigation system.MethodsThis prospective study included 50 knees undergoing primary ACL reconstruction using a navigation system. ACL remnants were classified into four morphologic types: Type 1, bridging between the roof of the intercondylar notch and tibia; Type 2, bridging between the posterior cruciate ligament and tibia; Type 3, bridging between the anatomical insertions of the ACL on the lateral wall of the femoral condyle and the tibia; and Type 4, no bridging of ACL remnants. Anterior tibial translation and rotatory laxity were measured before and after remnant resection using a navigation system at 30°, 60°, and 90° of knee flexion. The amount of change in anterior tibial translation and rotatory laxity of each type was compared among the types.ResultsThe different morphologic types of ACL remnants were as follows: Type 1, 15 knees; Type 2, 9 knees; Type 3, 6 knees; and Type 4, 20 knees. The amount of change in anterior tibial translation and rotatory laxity at 30° knee flexion in Type 3 was significantly larger than in the other types. There were no significant differences in either tibial translation or rotatory laxity at 60° and 90° knee flexion among the types.ConclusionsIn Type 3, ACL remnants contributed to anteroposterior and rotatory knee laxity evaluated at 30° knee flexion. The bridging point of the remnants is important to knee laxity. The Type 3 remnant should be preserved as much as possible when ACL reconstruction surgery is performed.Level of evidencePrognostic study, Level II.

Antimicrobial megaprostheses supported with iodine

Deep infection associated with implants remains a serious complication of orthopedic surgery. We developed iodine coating for titanium implants. In this study, we performed a clinical trial of iodine-coated megaprostheses to evaluate its safety and antibacterial effects. Forty-seven patients with malignant bone tumor or pyogenic arthritis were treated using iodine-supported titanium megaprostheses between July 2008 and May 2013. The mean age was 53.6 years (range, 15–85 years). Twenty-six patients were males and 21 were females. The diagnoses included malignant bone tumor in 29 cases, infected total knee arthroplasty in 11 cases, chronic osteomyelitis due to pyogenic arthritis in six cases and loosening of total knee arthroplasty in one case. The iodine-supported implants used were 42 Kyocera Limb Salvage System and five KOBELCO K-MAX K-3. These megaprostheses were used to prevent infection in 21 patients, treat active infections in 26 patients. The mean follow-up period was 30.1 months (range, 8–50). Infection was prevented in 20 out of 21 patients. Only one patient had surgical site infection caused by Pseudomonas aeruginosa and was cured by intravenous administration of antibiotics alone without removal of the implant. In 26 treatment cases involving one- or two-stage revision surgery, infection subsided without any additional surgery. In all cases, there were no signs of infection at the time of the last follow-up. White blood cell and C-reactive protein levels returned to normal within four weeks after surgery. To confirm systemic effects of iodine, thyroid hormone levels in the blood were examined. Abnormalities of thyroid gland function were not detected. Loosening of the implants was not observed. Excellent bone ingrowth and ongrowth were found around iodine-supported megaprostheses. The iodine-supported titanium megaprostheses are highly effective and show promise for the prevention and treatment of infections in large bone defects. No cytotoxicity or adverse effects were detected with this treatment.

Oblique coronal and oblique sagittal MRI for diagnosis of anterior cruciate ligament tears and evaluation of anterior cruciate ligament remnant tissue

BACKGROUND The purpose of this study was to investigate the efficacy of additional oblique magnetic resonance imaging (MRI) for the diagnosis of anterior cruciate ligament (ACL) tear and evaluation of ACL remnant tissue. METHODS We retrospectively reviewed the records of 54 knees. Three independent readers evaluated the MR images by the use of three methods: orthogonal sagittal images only (method A); orthogonal sagittal and additional oblique sagittal images (method B); and orthogonal sagittal and oblique coronal images (method C). The sensitivity, specificity, and accuracy for the diagnosis of an ACL tear and the detection of the condition of the ACL remnant tissue by the use of each method were calculated in comparison with arthroscopic findings as the reference standard. RESULTS The arthroscopic records revealed 27 knees with intact ACLs and 27 with torn ACLs. Among the 27 knees with torn ACLs, 9 did not have continuous remnant tissue and 18 had certain remnant tissue attached to the femur or the posterior cruciate ligament. The specificities and accuracies of methods B and C for diagnosing an ACL tear were higher than those for method A. The sensitivity, specificity, and accuracy of method C for the detection of ACL remnant tissue were higher than those for method A and B. CONCLUSIONS Additional use of oblique MRI improved the accuracy of diagnosis of ACL tear and showed a reasonable level of efficacy in detecting ACL remnant tissue. LEVEL OF EVIDENCE Level IV (case series).

Whole body muscle activity during the FIFA 11+ program evaluated by positron emission tomography.

Purpose This study investigated the effect of the FIFA 11+ warm-up program on whole body muscle activity using positron emission tomography. Methods Ten healthy male volunteers were divided into a control group and a group that performed injury prevention exercises (The 11+). The subjects of the control group were placed in a sitting position for 20 min and 37 MBq of 18F-fluorodeoxyglucose (FDG) was injected intravenously. The subjects then remained seated for 45 min. The subjects of the exercise group performed part 2 of the 11+for 20 min, after which FDG was injected. They then performed part 2 of the 11+for 20 min, and rested for 25 min in a sitting position. Positron emission tomography-computed tomography images were obtained 50 min after FDG injection in each group. Regions of interest were defined within 30 muscles. The standardized uptake value was calculated to examine the FDG uptake of muscle tissue per unit volume. Results FDG accumulation within the abdominal rectus, gluteus medius and minimus were significantly higher in the exercise group than in the control group (P<0.05). Conclusion The hip abductor muscles and abdominal rectus were active during part 2 of the FIFA 11+ program.

Contralateral anterior cruciate ligament injury after anterior cruciate ligament reconstruction: a case controlled study

PurposeThe purpose of this present study was to examine contralateral ACL injury cases after ACL reconstruction, to determine the characteristics of such injuries.MethodsWe performed a retrospective analysis of 24 patients with contralateral ACL injury after ACL reconstruction. The control group consisted of 200 cases with unilateral ACL injury. The following were examined in the contralateral group: timing of the contralateral ACL injury, and the situations of the initial and contralateral ACL injuries. The following items were compared between the contralateral and control groups: age at the time of initial injury, level of competitive sports using Tegner activity scores, knee anterior laxity (KT-1000), and the ratio (%) of affected to unaffected legs in the strengths of the knee extensor and flexor muscles 6 months after surgery.ResultsExamination of injury situations showed that approximately 70% of the contralateral group was injured in situations similar to those at their initial injuries. There were no significant differences between the two groups in age at the time of initial injury , Tegner activity scores, knee anterior laxity, and the strengths of the knee extensor, flexor muscles and H/Q ratio 6 months after reconstruction. But, the age at the time of initial injury trended to be low in contralateral group.ConclusionsKnee anterior laxity and muscle weakness of the reconstructed legs six months following surgery were not individually related to contralateral ACL injury occurring approximately two years after surgery.

Repair and augmentation of a spontaneous patellar tendon rupture in a patient with Ehlers–Danlos syndrome: a case report

AbstractIntroduction Disruption of the knee extensor mechanism is a serious disorder that requires prompt treatment. It often occurs in the form of a patellar tendon rupture. It may occur in association with systemic disease or after administration of corticosteroids or fluoroquinolones. These conditions can cause tendon weakness, and consequent ruptures usually require both repair and augmentation. This paper reports on repair and augmentation for treating patellar tendon rupture in patients with Ehlers–Danlos syndrome (EDS).Case reportWe report a patellar tendon rupture in a 27-year-old man with EDS, which occurred in the midsubstance of the patella. As the patient has tendon weakness, extensive repair will increase the risk of patella baja, and the use of end-to-end suturing technique alone will not be enough to prevent a rupture recurring; however, augmentation could be used to address the tendon weakness. Repair of the rupture and augmentation with hamstring tendon was performed. One year after the surgery, the patient was able to move his knee joint without pain and had an active range of motion of 0° (passive 20°)–145°. He was able to perform a straight leg raise without an extension lag.ConclusionsRepair and augmentation with hamstring tendon was an effective treatment option for patellar tendon rupture in a patient with EDS.

Clinical evidence of a familial predisposition to anterior cruciate ligament injury

Background Several risk factors for anterior cruciate ligament (ACL) injury have been evaluated in the literatures. It is highly probable that many of the identified risk factors for ACL injury are passed through families. However few articles describe a familial predisposition to ACL injury. Objective To investigate whether there is a familial predisposition to ACL injury. Design Retrospective study. Methods The study group comprised 350 consecutive patients who underwent ACL reconstruction between January 2005 and September 2008. All patients were surveyed by telephone or written questionnaire about their family history (FH) of ACL injury, sports in which family members participated and mechanisms of injury. We also compared age, height, weight, Tegner activity score, general joint laxity, and tibial slope between the FH group (with a FH of ACL injury) and a control group (without a FH of ACL injury). Results Complete information was obtained from 335 of the 350 patients, 38 (11.3%) of whom had a FH of ACL injury. Two families had three members with ACL injuries. Among the 40 family members with ACL injuries, 38 (95%) had a non-contact ACL injuries, and 34 (85%) injured their ACL by the same mechanism as the related patient. Comparisons of the FH and control groups identified no significant differences with regard to age, height, weight, Tegner activity score, or general joint laxity, but tibial slope was significantly larger in the FH group than in the control group. Conclusion Our results indicate a high probability that many of the identified risk factors for ACL injury are passed through families. Screening tests for a FH of ACL injury thus could identify a population at increased risk of ACL injury who would benefit most from preventative neuromuscular training programs designed to reduce the risk of ACL injury.