発育性股関節形成不全への人工股関節置換術における寛骨臼コンポーネント設置に対するCT-basedナビゲーションシステムの有効性

Purpose: Developmental dysplasia of the hip (DDH) presents a considerable surgical challenge in total hip arthroplasty (THA). Although the usefulness of computed tomography (CT)-based navigation in cup alignment has been reported, few reports have evaluated three-dimensional (3-D) cup positioning against the acetabulum specifically in patients with DDH. The purpose of this study was to evaluate the efficacy of a CT-based navigation system for alignment and spatial positioning of the cup in THA for patients with DDH. Methods: We reviewed 174 DDH THA cases in which CT-based navigation was used, and 75 cases in which a mechanical guide was used as a control group. Postoperative cup alignment and spatial positioning were evaluated by superimposition of a 3-D cup template onto the actual implanted cup using postoperative CT images, with pelvic coordinates matching the preoperative planning. Results: The proportion within the combined target zone (inclination and anteversion) was 97.7% in the navigation group and 61.3% in the non-navigation group. The mean absolute error between the intraoperative record and the postoperative measurement was 1.5° ± 1.3° for inclination and 2.1° ± 1.8° for anteversion in the navigation group. For acetabular cup positioning, the mean discrepancy between the preoperative planning and the postoperative measurements was 1.9+1.6 mm on the transverse axis, 2.8 ± 2.3 mm on the longitudinal axis, and 1.7 ± 1.3 mm on the sagittal axis. Conclusion: THA using a CT-based navigation system achieved quite high accuracy of cup alignment angles and spatial cup positioning in primary THA for patients with DDH

Revision total knee arthroplasty for unexplained pain after unicompartmental knee arthroplasty : a case report

In this report, we present a case of a 64-year-old woman who underwent revision of knee arthroplasty after failed unicompartmental knee arthroplasty (UKA). She underwent UKA (Biomet Oxford Phase 3) for right localized medial knee pain at the age of 53 and the postoperative course had been uneventful. Eight years after UKA, she had right knee pain that gradually worsened. Tenderness was present over the medial femorotibial and patellofemoral (PF) joints. Plain radiograph showed small osteophytes on the intercondylar eminence and in the lateral compartment. However, these findings were not severe. Although several causes of knee pain after UKA have been reported, none of those causes were found in this case, so the diagnosis of unexplained pain was made. We performed knee arthroscopy and it revealed severe osteoarthritis of the PF joint, bone attrition and exposure of subchondral bone of the medial part of the lateral condyle together with severe synovitis. Revision surgery was performed in the same operation. The postoperative course was excellent and the severe knee pain resolved after surgery. Several registries revealed that revision for unexplained pain was more common after UKA than after total knee arthroplasty. We pointed out the possible causes of unexplained pain including pathological conditions, which were present in our case. Revision surgery may be unsuccessful if the cause of failure is not adequately considered

Forearm lengthening by distraction osteogenesis : A report on 5 limbs in 3 cases

Radioulnar length discrepancy causes pain and decreases function of the wrist, forearm, and elbow. Limb lengthening, which has been used in the treatment of various deformities of the forearm, is necessary to restore balance between the ulna and radius. We treated 5 limbs in 3 patients (2 boys, 1 girl ; mean age 9.3 years old) with radioulnar length discrepancy by distraction osteogenesis of either the ulna or radius using external fixators. We dissected the interosseous membrane between the ulna and radius in 3 limbs in 2 cases and did not do so in 2 limbs of 1 case. These cases include 2 cases with hereditary multiple exostoses, and 1 case with multiple epiphyseal dysplasia. The results were investigated and evaluated in this study, using appropriate clinical and radiographic parameters, noting the state of the interosseous membrane, which has an important role in forearm stability. The mean fixation period was 113 days. The mean distraction distance was 22.8 mm. The mean follow-up period was 637.7 days. The mean ulnar shortening and radial articular angle respectively improved from 7.4 mm and 30.2° preoperatively to -0.1 mm and 34.8° postoperatively. Balance between the ulna and radius was restored, and the results showed significant improvements in range of motion of the joints. However, 2 unintended radial head subluxations occurred in 2 limbs without dissection of the interosseous membrane. In addition, a keloid remained in 1 limb due to pin site infection. Forearm lengthening by distraction osteogenesis was useful in our cases. It is important to recognize the function of the interosseous membrane when lengthening is performed by osteotomy of the proximal ulna by gradual distraction with an external fixator

The Posterior Condylar Cartilage Affects Rotational Alignment of the Femoral Component in Varus Knee Osteoarthritis

Rotational alignment of the femoral component in total knee arthroplasty (TKA) is important for patellar tracking and ligament balance. Preoperative planning based on radiography might have a potential risk for over-rotation because these X-ray based measurements can not detect asymmetric cartilage wear on posterior condyle. The purpose of this study is to evaluate the effect of the posterior condylar cartilage of varus osteoarthritic knee on rotational alignment of the femoral component in TKA. We established two different condylar twist angles (CTA) from intraoperative multiplanar reconstruction (MPR) images and intraoperative information of navigation system. The CTA measured by a navigation system that includes the cartilage (4.8±2.0°) was smaller than those measured by MPR images, which does not include the cartilage (6.6±2.1°) (p<0.05). The difference between these two angles that corresponds to the remaining posterior condylar cartilage was 1.7±1.2°. This result demonstrated that the posterior condylar cartilage might lead to over-rotational of the femoral component in varus osteoarthritic knee. Therefore, when determining rotational alignment of the femoral component, surgeons should consider the effect of the remaining posterior condylar cartilage to avoid the over-rotation of the femoral component, especially in severe varus knees

Successful Outcomes Using Interlocking Prostheses for Periprosthetic Fractures with Loose Femoral Components

Periprosthetic femoral fractures with implant loosening are difficult to treat, especially when accompanied by severe bone loss.We report here the treatment outcomes of 4 patients (1 man, 3 women ; age range 69-86 years) with periprosthetic femoral fractures and implant loosening after bipolar hemiarthroplasty. Fractures were classified according to the Vancouver classification as type B2 and B3, with adequate or compromised bone stock, respectively. One patient was initially treated conservatively but symptoms due to implant loosening persisted and revision surgery was required. All patients underwent revision using a long-stem cementless implant with interlocking screws as well as a cancellous allograft to augment the bone stock. At final follow-up (mean, 25 months), all patients had stable implant fixation, bony union of the fracture, and marked recovery of the proximal femoral bone stock through allograft use. This revision procedure achieved implant fixation and fracture healing with reconstitution of the femur even in the short term and even in cases with severe bone deficiency

Outcome of an elbow check-up system for child and adolescent baseball players

Purpose : Our aim was to examine the outcome of an elbow check-up system for youth baseball players. In particular, we investigated the nature of elbow injuries in youth baseball players with elbow pain and ultrasonographic findings of the capitellum. Materials and Methods : A total of 1605 players participating in the regional summer championship in July 2013 underwent a questionnaire survey, physical examination, ultrasound imaging, and radiographic examination. Results : A total of 499 (31.1%) players reported episodes of elbow pain, of whom 320 (64.1%) had abnormal findings on physical examination, and 115 (35.9%) agreed to undergo radiography. Among them, 98 (85.2%) exhibited radiographic abnormalities. On the initial ultrasonography screening, 60 (3.7%) players had an abnormal finding and 55 (91.7%) agreed to undergo radiography. Among them, 26 (47.3%) were found to have osteochondritis dissecans (OCD) of the capitellum on radiographs. Conclusions : About 30% of youth baseball players had episodes of elbow pain, and 64.1% of players with elbow pain had abnormal findings on physical examination. Furthermore, 85.2% of subjects who underwent radiographic examination exhibited radiographic abnormalities. About 4% of young baseball players had an abnormal finding on initial ultrasonography screening, and nearly 50% of them had OCD of the capitellum on radiographs

Surgery Related Complications in Percutaneous Endoscopic Lumbar Discectomy under Local Anesthesia

The minimally invasive percutaneous endoscopic discectomy (PED) as the postero-lateral approach with the local anesthesia was started in the late 20th century. The procedure only requires 8 mm of skin incision ; thus, it is the least invasive disc surgery presently. The surgery related complications were reviewed in the initial 100 cases from the single surgeon (K.S., first author). Two cases showed exiting nerve irritation, and complained of leg paresthetic pain for 6 to 12 weeks after the surgery (2.0%). The symptoms got better with medicines. One showed post-surgical epidural hematoma, and required surgical removal of the mass (1.0%). Two cases complained neck pain during surgery (2.0%). Surgeons would be aware of the specific complications for the postero-lateral approach of PED procedure

Arthroscopic excision of unstable os acromiale associated with impingement syndrome : a case report

Os acromiale is a rare anatomical variant that is caused by failure of fusion of the acromial apophysis and is usually asymptomatic. We report a case of impingement syndrome of the left shoulder secondary to unstable os acromiale, which was initially overlooked and confirmed only during arthroscopic examination. Arthroscopic excision of the unstable fragment was successful without residual dysfunction of the deltoid muscle

Optimizing baseplate position in reverse total shoulder arthroplasty in small-sized Japanese females : technical notes and literature review

The management of cuff tear arthropathy (CTA) has always been a challenge for shoulder surgeons. Introduction of reverse total shoulder arthroplasty (RTSA) helped in providing pain relief and improved shoulder function in patients with CTA. In this study, we aimed to evaluate the short-term clinical results and some clinical details regarding the types of available prosthesis, positioning, and size of the components for RTSA in a population of short-stature female Japanese. In our seven cases, the average glenoid size was 23.9 mm in width and 34.2 mm in height. The average width was smaller than the size of all available baseplates. We implanted reverse shoulder prostheses with baseplate that measured 28 mm in diameter and two locking screws. The center of the baseplate was shifted to allow slight anterior overhang relative to the anatomical center to avoid breakage of the posterior cortex and to achieve firm fixation. One case of humeral shaft fracture occurred while inserting the humeral stem and required encircling wiring. In our experience, the short term clinical results of RTSA were excellent, but a new prosthesis that is designed to fit the short stature of Asians with smaller glenoid and humerus should be considered